Document MeKv25v1m5wYr8yp6LM5BnQa

United States Patent [19] Brownscombe [li] 4,405,727 [45] Sep. 20,1983 [54] REINFORCED POLYMER COMPOSITIONS AND THEIR PREPARATION [75] Inventor: Thomas F. Brownscombe, Houston, Tex. [73] Assignee: Shell Oil Company, Houston, Tex. [21] Appl. No.: 296,032 [22] Filed: Aug. 25,1981 [51] Int. a.3........................C08K 3/34; C08L 25/04 [52] U.S. a.................................. . 523/205; 428/333; 428/336; 428/516; 428/517; 523/209; 524/444; 524/445; 524/449; 524/450; 524/451; 524/452; 525/903 [58] Field of Search.............. 428/333, 336, 516, 517; 523/205, 209; 525/903 [56] References Cited U.S. PATENT DOCUMENTS 3,640,943 3,686,355 3,755,231 3,893,969 4,017,452 4,071,494 4,129,549 4,151,136 4,200,565 4,210,572 2/1972 Bostick et al.......................... 523/209 8/1972 Gaines et al........................... 264/340 8/1973 Muir et al................................ 524/68 7/1975 Newbould et al.................... 523/209 4/1977 Schwarz............................... 523/205 1/1978 Gaylord ............................... 523/205 12/1978 Kahane ................................ 523/207 4/1979 Cornell................................. 523/205 4/1980 Naughton ............................ 523/200 7/1980 Herman et al......................... 523/200 4,251,432 2/1981 Martin................................... 523/205 Primary Examiner--Melvyn I. Marquis Assistant Examiner--Herbert J. Lilling [57] ABSTRACT A polymer reinforcing material, consisting of a particu late or filamentary mineral component having a thin polymer-interactive layer, averaging about 5-500 Ang strom in thickness, of silicon-free and heavy metal-free organic molecules chemically bonded to its surface by covalent bonding, when used in relatively small amounts in the range from 1 to 30 phr is capable of providing superior retention or increase of desirable polymer properties especially impact resistance, com pared to the use of conventional reinforcement in the same polymer, while providing increased stiffness and retention of strength at elevated temperatures. The reinforcing material is prepared by contacting a particulate or filamentary mineral component which has reactive sites at its surface with certain organic compounds at reaction conditions at which a covalent chemical bond is established between the mineral sur face and the organic compound by reaction of a reac tive site of the mineral with a site-reactive atom or group of the organic compound. 17 Claims, 3 Drawing Figures U.S. Patent Sep. 20,1983 Sheet 1 of 3 4,405,727 FIG. 1 EFFECT OF REINFORCEMENTS ON NOTCHED IZOD IMPACT STRENGTH % VOLUME MICA SOLID ORGANIC SOLID PREPARED LINE SOLID SUBSTRATE COMPOUND AS IN EXAMPLE NO. O I E m jz z z Z" A B D C' C C" MICA MICA MICA MICA MICA MICA MICA UNREINFORCED MATRIX UNTREATED MICA S-B-S 1 PS 2 B-S, TAPERED 6 S-(SB)-B-(BS)-S 4 S-(SB)-B-(BSJ-S 3 S-(SB)- B-(BS)-S 5 U.S. Patent seP. 20,1983 Sheet 2 of 3 4,405,727 FIG 2 IMPACT-STIFFNESS BALANCE IN HIGH IMPACT POLYSTYRENE MATRIX NUMERALS NEXT TO DATA POINTS INDICATE VOLUME PERCENT OF REINFORCING COMPOSITION. FLEXURAL MODULUS (UNITS I05PSI)~ SOLID ORGANIC LINE SOLID SUBSTRATE COMPOUND SOLID PREPARED AS IN EXAMPLE NO. AI I OE OM m V EL EL - - - 4 B C' D F - MICA GLASS MICA MICA MICA MICA GLASS -- -- -- S-B-S POLYSTYRENE 7 2 S-(SB)-B-(BS)-S 4 B-S, TAPERED 6 S-B-S 8 UNREINFORCED MATRIX UNTREATED MICA UNTREATED GLASS FIBER U.S. Patent Sep. 20, m3 Sheet 3 of 3 4,405,727 FIG. 3 4,405,727 12 onstrates that the siloxanes are not directly bonded to REINFORCED POLYMER COMPOSITIONS AND the glass. THEIR PREPARATION Another common surface finish for glass fibers is a family of chromium complexes, known as volanes. CROSS-REFERENCE TO RELATED 5 These have an ionic interaction with the surface of the APPLICATIONS mineral. It is not clear whether they are in fact ionically The polymer reinforcing compositions utilized in this invention are described and claimed in my co-pending application Ser. No. 257,834, filed Apr. 27, 1981. 10 bonded, as is claimed for them or whether they are hydrogen bonded like the silane compounds. In any event, they are not covalently bonded. A variety of similar treatments have also been dis BACKGROUND OF THE INVENTION closed for mineral fillers other than glass fibers, espe This invention is directed to improvements in poly mer compositions reinforced with particulate or fila mentary mineral polymer-reinforcing agents. More par 15 cially mica and wollastonite. For example, it has been suggested to polymerize monomers such as methyl methacrylate, acrylonitrile or the like by a free radical mechanism to deposit a polymer on the mineral surface. ticularly, this invention relates to thermoplastic poly On the basis of known reactivity of the different sorts of mers reinforced with chemically modified mineral rein radicals it is expected that these polymers are not cova forcing agents. lently bonded to the mineral surface. The Prior Art Mineral fillers of the prior art, especially those other 20 than glass fibers, must be added in large concentrations, Thermoplastic polymers are finding an increasing number of uses as structural materials. They are espe cially attractive as replacements for metals because of typically as much as 40 parts by weight per hundred parts of resin (phr) or more, in order to achieve the desired increase in stiffness. Addition of such large the reduction in weight that can often be achieved, as amounts of mineral fillers causes losses in other proper for example, in automotive applications. However, for 25 ties of the polymers, primarily impact resistance and any particular application, a thermoplastic polymer by tensile properties, rendering such polymers unsuitable itself may not offer the combination of properties de for many premium uses. sired and means to correct this deficiency are therefore Appropriately selected reinforcing materials accord of interest. In order to increase the rigidity and strength ing to the present invention have the advantage, when of thermoplastic polymers, it is a common practice to 30 used in lower concentrations from 1 to 30 phr, of pro incorporate a quantity of filler, e.g., a natural or syn ducing a desired increase in stiffness of polymers with thetic mineral material, in the particulate or filamentary out significant loss in other desired properties, and even form, e.g., as fibers or flakes. When the mixture of poly a gain in impact strength in some cases. mer and fibers or flakes is injection molded into a sheet form, the flow tends to cause the particles of filler to 35 SUMMARY OF THE INVENTION line up parallel to the sheet. If the particles have a high This invention comprises mineral reinforced non- aspect ratio and have a high rigidity and strength, they elastomeric thermoplastic organic polymer composi will then consitute an effective reinforcement in the tions in which novel chemically modified particulate or direction of alignment. Several types of mineral fillers are in commercial use. 40 filamentary mineral components are used as the rein forcements. The novel aspect of the reinforcing compo The most frequently employed are glass fibers, asbestos sitions is the presence of a very thin layer of certain fibers, clay-type minerals such as kaolin, calcium salts polymeric organic compounds bonded by covalent such as wollastonite and calcium carbonate and platy chemical bonding to the surface of the mineral material. clay minerals such as talc and mica. 45 The chemically modified reinforcing agents may be It is known that glass filaments must receive a chemi referred to as "polymer-bonded" reinforcements. The cal surface treatment or "sizing" in order to be effective novel chemically modified reinforcing compositions as polymer reinforcement. Silicon compounds, such as employed in this invention and method of preparing polysiloxanes, are typically employed for this purpose them are described in detail in my co-pending applica to provide adhesion between the glass and the thermo 50 tion Ser. No. 257,834. The disclosures of said applica plastic polymer. Other agents, such as "starch oil", tion are incorporated herein by reference. provide lubrication; polymeric materials have been used Compositions of this invention containing relatively to bind the fibers into a bundle. In the case of normal sizing of glass fibers, the sizing small amounts, in the range from 1 to 30 phr (parts by weight per 100 parts by weight of resin), of appropri compounds are not covalently bonded to the matrix. In 55 ately selected ones of said novel chemically modified such systems the glass fiber has a corrosion layer on the reinforcing compositions, exhibit superior retention, or surface. This is a layer of etched glass which has had the increase, of desirable polymer properties, especially alkali earth oxides leached out of it by water. On the impact resistance, compared to the use of conventional surface of this corrosion layer there are islands of poly reinforcement in the same polymer, while providing siloxanes deposited by the silane coupling agent. These 60 increased stiffness and retention of strength at elevated islands of polysiloxanes are hydrogen bonded to the temperatures. corrosion layer and not directly covalently bound to the The reinforced polymer compositions of this inven matrix. It is well known glass laminates treated with tion are generally superior to similar polymers rein silane sizing agents lose strength on immersion in water. forced with polymer-coated mineral fillers or reinforce This is because the water diffuses along the surface of 65 ments prepared by precipitating a polymer onto a min the glass fiber through this corrosion layer, wets the eral surface without chemical bonding of the polymer corrosion layer and lubricates the interface between the to the surface. They are also superior to compositions polysiloxane surface coat and the glass. This again dem prepared by suspending the filler or reinforcement in a 4,405,727 34 liquid in which a monomer is undergoing polymeriza is capable of interacting with the polymer, due to the tion. segment's length and similarity of structure to the poly BRIEF DESCRIPTION OF THE DRAWING mer, as if the segment were part of the polymer. The second characterizing component is an atom or group, FIG. 1 of the drawing illustrates the relation of im- S referred to herein as the "site-reactive" segment, which pact strength to amount of different reinforcing compo is capable of reacting with a reactive site on the surface sition. FIG. 2 of the drawing illustrates the relation of im pact to stiffness properties for several reinforced com positions. 10 FIG. 3 of the drawing illustrates the relation of Flex ural modulus of reinforced composites to matrix modu lus. of the mineral material to result in a covalent chemical bond between the mineral surface and the organic com pound. The mineral compositions which result from covalent bonding of such compounds to a mineral sur face may be referred to as polymer-interacting rein forcements. The organic compounds employed in pre paring the reinforcing compositions do not contain DESCRIPTION OF THE PREFERRED ,5 silicon or chromium--or other metals of Groups II- EMBODIMENTS The polymer reinforcing materials employed in this -VIII of the Periodic Table--as a substituent, and are therefore referred to as "silicon-free" and "heavy metalfree". invention consist of a mineral substrate and a polymer- The polymer-interacting component of the organic interactive layer which is bound to the substrate by compound must be one which will interact appropri covalent chemical bonding and is produced by chemical 20 ately with the polymer matrix which is to be reinforced. reaction of the substrate with a site-reactive organic The appropriate interaction is one which produces ad compound which has a polymer-interactive group. The mineral substrates include the particulate or fila mentary mineral materials which are known in the prior art as suitable for reinforcing organic polymer compositions, provided they have surface sites which are capa ble of covalent chemical bonding to a constituent of an organic molecule. Alternatively, a mineral material may be treated with a reagent which introduces reactive surface sites into the mineral surface. The most common and generally preferred mineral 25 30 hesion between the reinforcement and the polymer matrix, and most especially, it is the strong adhesion produced by the entanglement of polymer chains in the polymer-interacting group with similar polymer chains in the polymer matrix. For example, grafting of high molecular weight polypropylene to the surface of the filler provides the result that when the treated filler is processed with lower molecular weight polypropylene, the polypropylene grafted to the filler entangles the reinforcing materials contain or consist of silicates or polypropylene of the matrix, forming a bond as strong aluminosilicates and have as reactive sites on the surface as the tensile strength of the polypropylene matrix be oxygen atoms or hydroxyl groups. tween the filler and the matrix. A more dissimilar poly The group of suitable reinforcing materials includes: 35 mer, such as polyethylene, may be used for the graft and glasses; silicates; aluminosilicates, including mica, talc, will still result in interaction with the polypropylene clays (preferably bentonite or kaolin), vermiculite and due to wetting and polar or non-polar interactions of asbestos; calcium silicates, suitable wollastonite; silica the two polymers, the one of the matrix and the one and alumina. bound to the surface of the mineral. Particulate substrates may be naturally occurring or 40 The general subject of polymer compatibility, or manufactured particles of various shapes. Particulate or filamentary substrates of any aspect ratio or geometry molecular solution or entanglement, has been exten sively treated by various authors, as, for example, in the may be used. Especially suitable and preferred for poly two-volume publication Polymer Blends, edited by D. mer reinforcement to improve strength and stiffness or R. Paul and Seymour Newman, Academic Press, New hardness are platy particles such as mica and vermicu- 45 York, N.Y., 1978. A normal test of polymer compatibil lite. Preferred dimensions for such platy reinforcements ity involves mixing two polymers intimately by melt or are 100 to 1000 microns in length and width and 1 to 6 solution mixing and observing whether the glass transi microns in thickness. Especially preferred for improve tions of each are preserved or the material exhibits only ment of strength and stiffness of the reinforced poly one coalasced glass transition. In the latter case, the mers are platy reinforcements of high aspect ratio, in 50 polymers are compatible; that is, they are molecularly the range from 20 to 200. mixed. Such molecular mixing between the grafted Filamentary substrates may be standard glass fibers, polymer and the polymer matrix is a sufficient but not a chopped or continuous or milled; or naturally fibrous necessary condition for the practice of this invention. minerals, such as asbestos. Conventional chopped glass Our data establish that benefits in properties of the com fibers typically are 2 to 15 millimeters in length before 55 posite result even from the lesser interactions exhibited use and 0.3 to 4 millimeters after they are compounded by incompatible polymers such as S-B-S thermoplastic in a polymer matrix. Aspect ratios may be as low as 10. elastomers and polypropylene. The polymer interactive layer of the polymer rein Thus, any pair of compatible copolymers is suitable forcing materials used in this invention is created by for use as matrix and-polymer interactive segment ac chemical reaction between the mineral substrate and 60 cording to this invention. Most desirably, the number certain organic compounds. average molecular weight of the polymer-interactive The molecules of the organic compounds employed segment is at least about one-sixth, and suitably at least in producing the bonded surface layer of said reinforc about half that of the matrix polymer. For various ing compositions are characterized by two essential classes of materials such as "polar" or "non-polar", component parts. One component part is a segment of "saturated" or "unsaturated" polymers, two polymers substantial length, referred to herein as the "polymer- taken out of the same single group of the above-quoted interacting" segment, which, when the polymer-bonded groups are likely to be suitable as matrix and polymer mineral particle or filament is present in a polymer melt, interactive materials as well. 4,4UD,/Z/ 56 It has been found especially useful to employ as the polymers contemplated herein are non-elastomeric ma polymer-interactive component suitable for reinforcing terials including, without limitation: styrene-based poly hydrocarbon polymer matrices one of several types of mers, copolymers, and graft copolymers; olefin-based hydrocarbon block copolymers. These compositions polymers and copolymer; nylons; poly(ethylene tere- are well known thermoplastic elastomers, many of them 5 phthalate); poly(butylene terephthalate); acrylonitrile- commercially available, and are described, i.a., in nu butadiene-styrene terpolymers; polyketones; poly(- merous patents. One group of such polymers consists of phenoxy); poly(aryl ether); poly(aryl ester); and poly linear block copolymers having polystyrene end blocks urethane. and polybutadiene or polyisoprene center blocks and The following represents appropriate choices of the products obtained by partial hydrogenation of such 10 polymer-interacting segments for given polymer matri copolymers to produce polymers having primarily pol- ces. Matrix Polyolefin e.g., polyethylene, polypropylene, poly-l-butene, etc., especially isotactic homo- and copolymers, including so-called block copolymers. Poly(vinyl arene) homopolymers and copolymers; e.g., polystyrene; ABS, SAN, etc. Polyesters e.g., polybutylene terephthalate (PBT), polyethylene terephthalate (PET) Poly(phenoxy) Poly(aryl ether) Nylons Polyurethane Polymer-interacting segment of the chemically modified mineral Polyolefin e.g., linear polyethylene, poly propylene, etc., including plastic or elastomeric random and block copolymers. The monomer need not be identical to that of the matrix polymer, so long as the segment is capable of being dispersed in the matrix polymer in melt form. Block polymers A-B or A-B-A where B is a polydiolefin, e.g., poly butadiene or polyisoprene and A is a poly(vinyl arene), e.g., polystyrene; poly(vinyl arene) homopolymers and copolymers; e.g., polystyrene, ABS, SAN, etc. PBT or PET Polyphenoxy Poly(aryl ether) Polyaryl, e.g., polystyrene Polyamide; polyurethane Polyurethane; polyamide; molecules containing groups capable of grafting reacting with poly urethane, e.g., epoxy or --NH2. ystyrene end blocks and hydrogenated polybutadiene center blocks. Reference for the preparation and com- 40 positions of such polymers may be made to U.S. Pat. A preferred combination comprises hydrocarbon No. Re. 28,236 and U.S. Pat. Nos. 3,595,942, 3,810,957, polymers reinforced with compositions in which the 4,208,315 and 4,242,470. As explained therein, polysty- polymer-interacting segment is a hydrocarbon, result rene-polybutadiene-polystyrene and polystyrene- ing from use of a hydrocarbon polymer in the prepara polyisoprene-polystyrene block copolymers may be 45 tion of the reinforcing mineral composition. abbreviated "S-B-S" and "S-I-S", respectively, and their derivatives in which the center block is hydroge Preparation of the Polymer Reinforcing Materials nated may be designated "S-EB-S" and "S-EP-S", re The mineral compositions having a thin polymer- spectively. Molecular weights of the blocks in the interacting layer bonded to the surface by covalent ranges disclosed in said patents tend to be useful in this 50 bonds, which are employed in the reinforced polymer invention. Another related block copolymer is of the compositions of this invention, are prepared by contact type S-(SB)-B-(BS)-S, which is disclosed in U.S. Pat. ing a particulate or filamentary mineral component Nos. 3,906,057, 3,906,058, 3,907,929 and 3,907,931. In which has reactive sites at its surface with a polymer- this case, (SB) and (BS) refers to so-called "tapered" interactive, site-reactive organic compound at reaction polymer structure, which consists of molecules or 55 conditions at which a covalent chemical bond is estab blocks in which at one end there is a chain of essentially lished between the mineral surface and the organic only one type of monomer and units of the other mono compound by reaction of a reactive surface site of the mer are present at increasingly greater frequency until mineral with a site-reactive atom or group of the or at the other end of the block or molecule there is a ganic compound. random distribution of the two monomers. Still another 60 Various methods, described in detail in my co-pend- type of useful block copolymer is a tapered two-block ing application Ser. No. 257,834, may be employed to polymer having, for example, about 30% styrene and prepare the reinforcing compositions used in this inven 70% butadiene content, the polybutadiene component tion. A first mode of preparation involves the acid cata having about 10% vinyl structure. lyzed reaction of an olefinic double bond contained in a The relevant disclosures of the above referred to 65 polymer with a mineral surface. A second mode com patents are incorporated herein by reference. prises nucleophilic attack of a mineral substrate on a Various thermoplastic polymers can be reinforced in polymer which contains a group labile to nucleophilic accordance with the present invention. Thermoplastic attack. A third mode comprises a nucleophilic attack by 4,4U:>,/Z/ 78 a polymeric material on a susceptible bond in a mineral ous energies is determined by the numbers of different reinforcement. The following summarizes preferred types of atoms present and the response of each of the methods illustrating each of these modes. various electrons in the atom to that particular type of In the first mode, mineral material which has reactive X-ray. It is well known that the response factors of the oxygen at its surface is brought into contact with an 5 various elements may be tabulated and elemental analy organic compound which has as the site-reactive group sis may be performed on surfaces by using this equip at least one olefinic double bond per molecule under ment. The various types of reinforcements described in reaction conditions at which the double bonds of the this patent- application have been analyzed by ESCA. organic molecule or active oxygen on the mineral sur By comparing the ESCA results obtained on (1) an face or both are protonated, whereby a covalent chemi- 10 untreated substrate, (2) a substrate after treatment, as cal bond is established between the mineral surface and described in the examples, to react it with an organic the organic molecule. molecule; and (3) a substrate after such treatment, fol In the second mode, mineral material which has reac lowed by contact with solvents under conditions at tive oxygen at its surface is brought into contact with an which coatings which are not chemically bound would organic compound which has, as the site-reactive 15 be removed, it has been determined that the elements of group, a substituent atom or group which is capable of the polymer interactive materials are incorporated on nucleophilic displacement by reactive oxygen under the surfaces of the reinforcement materials by chemical reaction conditions at which at least one such substitu bonding--that is, in such a way that they cannot be ent group or atom is displaced by an oxygen atom from washed off or extracted by appropriate solvents. In the mineral surface, thus creating a covalent chemical 20 addition to this determination, the thickness of these bond between the surface and the organic molecule. layers has been estimated by comparing the relative In the third mode, reactive sites consisting of groups attenuations of two different electrons from the same capable of nucleophilic displacement are created on the element. The apparent layer thicknesses determined by surface of mineral material by reacting the mineral with this technique are not necessarily accurate but permit a reagent which creates a "leaving group" or by drying 25 comparison of the thickness of organic coatings on an at an elevated temperature, and the modified mineral inorganic substrate in different samples, provided that material is contacted with an organic compound which the organic coating is uniformly distributed in a film of has a nucleophilic group on the site-reactive group at constant thickness and that the element being used for reaction conditions at which a covalent bond is estab the analysis is uniformly distributed in the inorganic lished between the mineral surface and the organic 30 substrate. Based on these assumptions, the data ob compound. served for any polymer interactive grafted layers are As shown in the illustrative examples, the fully-pre reproducible, although it cannot be said with certainty pared reinforcing solids were generally given multiple what the exact thickness is. Thus, it is possible that the washes with a hydrocarbon solvent, typically the same layers cited as being 20 Angstroms might indeed be 40 as that in which the product had been prepared. Such 35 or 50 Angstroms. washes are desirable in a study of the methods of prepa The range of 5-500 Angstroms, which is disclosed ration, since they remove non-grafted polymeric mate herein as being the average thickness of the co-valently rial. However, such removal of non-grafted material by bound organic molecules, is thought to be sufficiently means of solvent washes is not essential to practice of broad to take account of this lack of precision in mea the invention. 40 surement. In any event, it contrasts with a thickness of The use of any of the reactions outlined in modes 1, 2, the order of about one-half micron (5000 Angstroms) or 3 will automatically produce a layer which charac characteristic of coatings such as applied by precipita teristically, as evaluated by electron spectroscopy for a tion from solution or conventional silane sizings. chemical analysis (ESCA) will be in the range of about Another method of employing ESCA for approxi 5 to 500 Angstroms, in thickness, and typically between 45 mate determination of layer thickness is by determina 10 and 100 Angstroms in thickness. The cause of this tion of the ratio of the various surface atoms. For exam self-limiting thickness is not known with certainty. It is ple, one can compare the amount of carbon on the sur believed that it may be due to saturation of the surface face with the amount of silicon on the surface to get an reactive sites on the mineral with site interactive groups approximation of the amount of hydrocarbon polymer on the polymer, leaving a mineral surface covered with 50 deposited on a silicon-containing mineral. In many the polymer interactive tails and the site interactive cases, this and the previously described technique, once materials in such a way that it is impossible for further calibrated to agree at an initial point, were found to attack on the surface to occur. Not every site on the agree over a wide range of materials. In some cases mineral, therefore, may be reacted and the polymer there was some variance between the results of the two interactive chains left on the surface will not be interac- 55 methods. The reported value is an average of the two tive with the site reactive groups left in solution. techniques. Determination of thickness of polymer interactive Preparation of the Reinforced Polymer Composites layers on reinforcement substrates Polymer compositions reinforced with the above- The technique used to analyze the surface layers 60 described chemically modified mineral materials may discussed in this application was X-ray photoelectron be prepared by methods known for the production of spectroscopy (XPS), also known as "Electron Spectros mineral-filled thermoplastics. A major difference, how copy for Chemical Analysis" (ESCA). In this tech ever, is that according to this invention the mineral nique, a material is bombarded with X-rays which eject reinforcements are present in much lower concentra photoelectrons from the core levels of the atoms in the 65 tions, in the range from 1-30 phr, and especially in substrate material. The energy of these electrons is de concentrations not exceeding 20 phr, and preferably 3 termined by the energy levels of the electrons in the' to 20 phr, compared to conventional filled thermoplas various atoms and the distribution of electrons of vari- tics which typically contain 40 phr or more of filler. 4,403, U! 9 10 The filled composition may be prepared, for example, by mixing the desired amount of reinforcing material with particulate polymer and submitting the mixture to conditions at which the modified mineral is incorpo rated in the polymer, e.g., by compounding the mixture 5 by means of a melt-mixing device, such as an extruder or Banbury compounder, either for direct use, as in injection molding or extrusion of sheet or other desired profiles, or for pelletizing to provide a salable rein forced resin. Because of the improved adhesion of these 10 fillers to the polymer matrix, it is desirable to avoid conditions during blending of the fillers with the poly mer which result in excessive attrition or fragmentation of these fillers. The invention is further illustrated by the following 15 examples. These are given for the purpose of illustration only and are not meant to limit the invention to the particular reactants and conditions employed therein. The following materials were employed in a number of the examples and are therefore referred to by an 20 abbreviated designation for ease of reference. TABLE 1-continued SIEVE ANALYSIS OF MICA SUBSTRATE Hammer-milled Phlogopite Mica Weight % Retained on Sieve Substrate No. Mesh M-l M-2 M-3 +70 + 100 + 140 +200 +325 +400 +20 Microns +20 Fines Aspect Ratio 29.2% 27.3% 9.05% 2.0% 0.85% 0.5% 63 18.45% 20.00% 23.10% 5.60% 32.85% 60-70 1.95% 8.75% 34.75% 36.45% 15.8% 2.8% 20-30 Matrix Test Temp. c. TABLE 2 PROPERTIES OF MATRICES Yield Flexural Stress Notched Izod. 75` F. Modulus psi* (Units .0018 % Elon- Ft-Lbs/ inch Ratio 105 psi) min."1 gation Gate End R M-l M-2 M-3 M-4 0-1 0-2 0-3 0-4 0-5 0-6 0-7 C-l C-2 C-3 C-4 S-I S-2 S-3 S-4 P-l P-2 P-3 P-4 P-5 P-6 Substrates Phlogopite Mica (nominally 60 mesh)-Sieve analysis in Table 1 Phlogopite Mica (nominally. 200 mesh)-Sieve analysis in Table I Phlogopite Mica (nominally 320 mesh)-Sieve analysis in Table 1 Glass Fibers - "E-Glass" i inch long, 13 micron diameter Organic Compounds S-B-S Block Copolymer - Commercial polymer; nominal styrene.rubber weight ratio = 30:70 S-EB-S Block Copolymer Commercial polymer; nominal styrene:rubber weight ratio = 29:71 B-S "Tapered" Two-Block Copolymer - Commercial polymer; nominal styrene:rubber weight ratio = 29:71 S-(SB+B-(BS)-S Block Copolymer - Nominal molecular weights of the blocks ( X 10--J) -- 67-30-260-30-67 Polystyrene - Commercial crystal grade - melt flow range 2-3 Polypropylene - Commercial product - nominal melt flow 5 "Living Polymer" of lighium-terminated polystyrene; nominal molecular weight 30,000 Catalysts, Acid Acceptors and Chemical Reagents Triflic Acid (Trifluoromefhane sulfonic acid) p-Toluene sulfonic acid Bromine Thionyl chloride Solvents Toluene Cyclohexane Bromobenzene Benzene Polymer matrices (Relevant Properties in Table 2) Polypropylene - commercial polymer - nominal melt flow 5 Polystyrene - commercial crystal grade - melt flow range 2-3 High Impact Polystyrene - blend of organic compound 0-4 in polystyrene - melt flow range 2-3 Commercial High Impact Polystyrene - blend of polybutadiene in polystyrene - melt flow range 3-4 Blend of 15% of organic compound 0-1 in 85% of Matrix P-4 Blend of 30% of organic compound O-i in 70% of Matrix P-4 _________________ TABLE 1______________ SIEVE ANALYSIS OF MICA SUBSTRATE Hammer-milled Phlogopite Mica Weight % Retained on Sieve __________________Substrate No.__________ Mesh_________________ M-l___________ M-2___________ MO -t-50 21.1% p-i 25 P-2 P-3 P-4 P-5 P-6 25 27 19 19 19 25 1.9 4.6 2.87 3.13 2.41 1.67 3700 5550 2984 2780 2292 1530 1.25 29 25 34 49 0.42 0.2 8.37 3.1 5.87 9.84 3 6.34 1.5 3.52 8.61 1 1.32 2.10 1.67 1.14 30 PREPARATION OF REINFORCING SOLIDS EXAMPLE 1 35 Starting Materials Product Mineral Substrate Organic Compound Catalyst Solvent M-l Mica O-l S-B-S C-l Tridic Acid S-l Toluene Solid A 40 141.1 g of block copolymer 0-1 was charged with 3100 cc dried industrial grade toluene (S-l), to a 4 liter resin kettle, stirred under nitrogen, and warmed to dis solve the block copolymer. 1022.7 g of as received mica 45 M-l, dried in a vacuum oven for 2j hours, was poured into the resin kettle under moisture-free conditions. The hot mixture was stirred under nitrogen at about 80-100 C. for one hour. Two cc of acid catalyst C-l was added to 30 cc toluene in a dry box and shaken to 50 mix, forming a cloudy, yellowish solution. Fifteen cc of the solution was injected with a syringe into the hot stirred mica suspension. The mica suspension' was stirred for 20 minutes and the last 15 cc of catalyst solution injected. The mixture was refluxed for 1 hour 55 at atmospheric pressure and about 111 C. 1.8 liters liquid was sucked off of the mica through a 100-mesh screen. Two liters fresh toluene was added, the suspen sion stirred and left overnight under nitrogen flow. The following day, 1.3 liters toluene was sucked off, 2 liters 60 fresh toluene added, the suspension stirred, 2 liters tolu ene sucked off, and this washing procedure repeated two more times. The mica was sucked dry, transferred to a vacuum oven, left overnight at 30" of mercury vacuum at 50 C. The following morning the mica was 65 comletely dry. The mica was passed through a No. 10 screen with a rubber stopper to disperse the clumps which formed in the bottom of the evaporating crystal lizing dish. 1 kg mica was recovered. 11 12 EXAMPLE 2 -continued Starting Materials Product Starting Materials Product Bromobenzene and Benzene Mineral Substrate Organic Compound M-l Mica 0-5 Polystyrene Solid B A 250 ml round bottom flask fitted with heating man Catalyst Solvent C-l Triflic Acid S-l Toluene tle, nitrogen blanket and reflux condenser was charged with 100 ml of bromobenzene and 5.0 grams of polypro pylene. The mixture was heated, and stirred with a In a 4 liter resin kettle, 100 g of crystal polystyrene 10 Teflon stir bar. After 3 hours most of the polypropylene (0-5) in 3100 cc dried toluene (S-l) was stirred and appeared to have dissolved; the skin temperature of the wanned under nitrogen to dissolve the polystyrene. heating mantel was 180 C. At this point 100 ml of hot Two cc of acid catalyst C-l in 60 cc dry toluene was benzene was added to dilute the bromobenzene. 0.5 added slowly to the warm polystyrene solution under grams of bromine was added to the solution, which nitrogen, turning the solution pale yellow. 1005 g of 15 turned red-orange, making the undissolved polypropyl mica (M-l), dried in a vacuum oven, was immediately ene clearly visible. The reaction was carried out under added to the stirred acid mixture under moisture-free fluorescent lights, since the bromination of polypropyl conditions. The mixture was stirred for 30 minutes with ene is activated by light. The solution was poured into warming and a second solution of 2 cc C-l and 60 cc a 4 liter nitrogen flushed resin kettle preheated to 100 toluene added. The mixture was brought to reflux for an 20 C., through a 100 mesh screen which sieved out 0.19 hour and filtered hot with a 16 mesh filter. The resulting grams of undissolved polypropylene. 3.1 liters of hot suspension was washed several times with toluene, as in benzene was added to the solution, which was now Example 1. The resultant mica looked exactly as re-, yellow. Four microdrops of bromine, totaling 0.15 ceived mica--it appeared very dry, no adhesion noted grams, were added and the solution turned orange. The between flakes. 25 reinforcement material to be grafted was then sus EXAMPLE 3 pended to the resin kettle and the mixture stirred under reflux for a period of 30 minutes to 4 hours. The rein forcement material was then removed from the liquid Starting Materials Mineral Substrate Organic Compound Catalyst M-2 Mica 0-4 S-<SB)-B-(BS)-S C-l Triflic Acid Product Solid C and washed with 150 ml of hot bromobenzene, followed 30 by 4 washes with 300 ml of hot benzene. The material was then sucked dry on a filter and allowed to dry in a stream of nitrogen overnight. Solvent S-l Toluene ESCA studies of mica treated substantially as in the described preparation confirmed the presence of a poly ' 50 g of block copolymer 0-4 was dissolved in 300 ml 35 meric layer which could not be removed by extraction toluene (S-l) in a 4 liter resin kettle. 5 cc of acid catalyst with benzene or bromobenzene in a Soxhlet extractor. C-l was dissolved in 150 ml toluene in a dry box. The EXAMPLE 10 solution of polymer together with 1000 g of dry mica M-2 and the catalyst solution was charged into the resin A polymer reinforcing composite particularly suit kettle. The mixture was refluxed 2 hours and let cool 40 able for use in reinforcing thermoplastic phenoxy resins, overnight under nitrogen blanket. The mica was i.e., resins having chains of groups of the structure washed several times with toluene. After washing, the mica was air dried on a filter funnel and vacuum dried in the oven at 30" mercury overnight, and passed through a 50 mesh screen. 45 EXAMPLES 4-8 The following solids are prepared similarly to the method of Example 1. which may be terminated with epoxy groups and have Example 4 5 6 7 8 Mineral Mica Mica Mica Mica Glass STARTING MATERIALS Substrate Organic Compound Catalyst Solvent PRODUCT M-l Block Copolymer 0-4 Acid C-l S-l Solid C' M-3 Block Copolymer 0-4 Acid C-l S-l Solid C" M-l Block Copolymer 0-3 Acid C-l S-l Solid D M-l Block Copolymer O-l Acid C-2 S-l Solid E M-4 Block Copolymer O-l Acid C-l S-l Solid F EXAMPLE 9 Starting Materials Mineral Substrate Organic Compound Reagent Solvents M-l Mica 0-6 polypropylene C-3 Bromine S-3 and S-4 Product SolidG molecular weights of the order of 40,000, may be pre pared as follows: A polyepoxide resin such as a higher molecular weight solid epoxy resin produced from epichlorohy- 65 drin and 2,2-bis(4-hydroxyphenyI)propane (Bisphenol A) is dissolved in a suitable solvent, such as a ketone, and permitted to reach with a solid substrate such as mica or glass, typically at temperatures between 50 to 4,405,727 13 14 150* C., depending on the solvent used. The resulting with toluene or cyclohexane or extraction in a Soxhlet solid is thereafter recovered, washed with fresh por extractor. tions of the reaction solvent and dried. Application of Coating Layer To Minerals Having EXAMPLE 11 5 Covalently Attached Polymer Reactive Surface Layer Chemically modified mineral substrates can be coated PrctreaUnent of Substrate Starting Materials Mineral Substrate Reagent Solvent M-l Mica C-4 Thionyl chloride S-l Toluene Product Solid H-l with a further polymer layer and this new product used to advantage as polymer reinforcement. The resulting products and their preparation and use are the subject of 10 separate, copending patent applications. This separate use of the compositions of this invention is illustrated in the following examples 12-15. A 4 liter resin kettle, dried and flushed with nitrogen, was charged with 2 liters of toluene dried over a molec ular sieve. 500 grains of mica M-l, dried overnight in a 15 EXAMPLE 12 vacuum oven at 30 inches of mercury and 120* C., was charged to the toluene. A solution of 20 grams of thionyl chloride (168 mmoles) in 12 ml of dried toluene was made up in a dry box. This solution was added dropwise 20 to the rapidly stirred mica suspension over a period of Starting Materials Solid Organic Compound Solvent Solid A O-l S-B-S S-l Toluene Product SolidI 30 minutes. After the addition was finished, the resin kettle was heated for a period of 40 minutes, at which point the color in a trap with acid indicator, fitted to the In a 2 liter beaker, 40 g of block copolymer 0-1 was dissolved in 1200 ml toluene with heating and stirring. exit nitrogen line, had faded, indicating that the theoret ical amount of HC1 had been evolved by the reaction of 25 401.8 g of Solid A, prepared according to Example 1, was stirred into the solution for 5 minutes. The mixture the thionyl chloride with the hydroxyl groups on the was placed in a vacuum oven and evacuated very surface of the mica. The final temperature of the skin of slowly to dryness with periodic mixing. The resulting the kettle was 137 C. The mixture was then refluxed solid contained about 10 percent by weight of the S-B-S for 2 hours, a distillation head was attached and excess 30 polymer as a coating on the starting solid. thionyl chloride and toluene were distilled off of the mica. The mica was then heated over a period of 2 EXAMPLE 13 hours at 200 C. with nitrogen admitted to the bottom of the mass through a stainless steel tube to completely dry the mica and evolve the vapors resulting from decom 35 position of the SOC1 moieties on the surface of the mica. The mica was then divided into 3 150 g. samples and Starting Materials Solid Organic Compound Solvent Solid A O-l S-B-S S-l Toluene Product SolidJ stored under nitrogen in wide mouth bottles. Preparation of Reinforcement from Pretreated Substrate Starting Materials Product Mineral Substrate (pretreated) Organic Compound Solvent Solid H-l 0-13 Lithiumterminated polystyrene S-2 Cyclohexane Solid H The preparation of Example 12 is repeated with half 40 the proportion of Solid A, to produce a reinforcing material coated with about 20% by weight of S-B-S copolymer. EXAMPLE 14 45 Starting Materials Product 150 g of mica, treated with thionyl chloride as de scribed, was removed from the dry box and moistened Solid Organic Compound Solid C O-l Solid K with 186 g of dried cyclohexane in a 500 cc round bot 50 tom flask, stoppered with a serum cap. 216.2 g of a living polymer cement containing 9.63% solids (0-13), EXAMPLE 15 which was a living polystyrene polymer of 28,000 to 32,000 (nominal 30,000) molecular weight, dissolved in cyclohexane, was added through the serum cap to the 55 mica in the flask. The red color of the living cement was immediately quenched by reaction with the mica, indi Starting Materials Solid Organic Compound Solid C 0-4 Product Solid L cating that the grafting reaction appeared to be quickly complete at room temperature. The mixture was heated In 2 liter battery jars, 250 g of Solid C, prepared for 2 hours at 60-70 C. with occasional mixing to be 60 according to Example 3, was charged with 500 cc tolu certain the reaction was complete. A condenser was ene and 25 g of block copolymer 0-1 and 0-4, respec attached to the flask, which was swept with a dry nitro gen purge and refluxed for 2 hours after the initial 2\ tively. The mixtures were stirred over a hot plate until the polymer dissolved and the suspensions were well hour reaction. The next day the solution was decanted mixed. The suspensions were placed in a vacuum oven from the mica, which was washed repeatedly with cy 65 and dried overnight at 50 C. The procedure resulted in clohexane in 500 ml quantities and washed 3 times with solids coated with 10% by weight of S-B-S and of S- 500 ml quantitites of toluene. ESCA analysis showed no (SB)-B-(BS)-S block copolymers, respectively, over a change in the polymeric coating on further washing co-valently bound thin layer of S-(SB)-B-(BS)-S. 4,40VZ/ 15 16 Effectiveness of Mineral Composition of the Invention in Reinforcing Polymers The selected load was slowly applied and maintained for one minute, which permitted some inelastic strain relaxation to take place and for the deflection to reach EXAMPLE 16 a steady, reproducible value. The flexural modulus was Mineral reinforcements prepared as above were em- 5 calculated using the elementary bending formula for a ployed in reinforcement of polymers and the resulting simple beam subject to three point bending. solids tested for impact and stiffness properties. Tensile tests were performed using a model TTC 500 grams batches of filled composition-of polymer Instron testing machine and a microformer extensionm- matrix and treated mineral substrate were prepared as eter (Baldwin) attached to the gage section of the stan follows: The components--e.g., treated mica flake and poly dard injection molded tensile test bar. The total length of the straight portion of the gage section was 2.75 styrene beads--were mixed by shaking and tumbling for inches. The nominal cross sectional dimensions were i a few minutes in a two-quart glass jar. Melt mixing was inch X i inch. Thin strips of adhesive tape were intro carried out using a single screw extruder operated ]5 duced between the surface of the specimen and the knife under the following conditions: edges of the extensiometer to prevent failure from in dentation stresses. Extensiometer sensitivity was a chart Brabender Extruder motion of 2 inches for a strain of 1%. The crosshead Dimension of Screw--25" X 1" Temperature--210 C. 2c Screw RPM--90 Extrudate was solidified on a Teflon coated aluminum sheet and subsequently chopped into beads. Extrusion was repeated a second time and extrudate again was chopped into beads. 25 motion was set at 0.005 inches/minute corresponding to a strain rate of 0.0018 minute-1 at the gage section. Yield stress and % elongation to fracture were obtained from the tensile test. The effect of various reinforcements on improving the stiffness of the reinforced composites was evaluated by means of the following equation: The 500 gram batch of beads then was injection molded into test bars, using the following machine set Ec=FEm tings: where: Battenfeld Injection Molding Ec=Young's modulus of the composite 30 Em=Young's modulus of the matrix polymer. Temperature--465 F. Injection Pressure--950 psi Clamping Pressure--1800 psi The function F is a constant for a homologous series of composites in which the aspect ratio, dispersion and volume fraction of the reinforcement are the same, but Back Pressure (feed)--250 psi Mold Temperature--100 F. Each molding cycle 35 the polymer matrix and the surface treatment of the reinforcement may vary. Plotting the ratio Ec versus produced one tensile test bar, two Izod impact test bars, and a circular disk. The tensile test bar was used to measure flexural modulus; the same bar was used for the tensile test. The two Izod test bars Em for a series of composites using, in each case, a single reinforcing solid prepared as above in different polymer matrices, showed that within this series data for com posite subgroups which have the same volume fraction were used to measure notched Izod impact strength for two mold positions, viz., near the "gate" and near the "dead" end. Tests were per formed in the temperature range 222 C. A de scription of test methods is given in the following section. 40 45 lie on straight lines through the origin. The slopes of the lines increase with volume fraction. This is determined primarily by the function F; this slope also can depend on surface chemical treatment as well as effectiveness of dispersion. Plots of Ec/Em were prepared for six chemically Test Methods and Evaluation treated reinforcements. To characterize the effect of Three mechanical property tests were performed: (i) notched bar Izod impact test, (ii) three point bend test, and (iii) uniaxial tensile test. The notched Izod test was carried out according to ASTM specification D-256-A-73 at an ambient temper ature of 222 C. using J inch thick test bars. Flexural modulus was determined using a three point bend testing fixture with a 2.00 inch span between load reaction points. A load of a magnitude such that the maximum tensile bend stress would remain below 1500 psi, according to the formula: 50 55 chemical treatments on flexural modulus, a master plot of Ec/Em versus volume fraction mica was constructed. Points on this plot were taken from the average straight lines of previous plots, of Er versus Em, which give a mean value for each dispersion. The greater the slope of a line passing through the origin at Ec/Em-- 1, the more effective the treatment may be regarded in creating a tight bond at the mica-matrix interface. The slope of a line is indicative of the rigidity of the resulting compos ites. In Table 3, the composites are ranked in order from most rigid to most compliant, based on the slopes of their Ec/Em plots. 2 <Tmax -- 1 i Px L 1 wX r where crmax=maximum tensile bend stress P=applied load L=span between load reaction points t = specimen thickness w = specimen width. 60 TABLE 3 RANKING CHEMICAL TREATMENTS THROUGH THEIR EFFECT ON FLEXURAL MODULUS Example Solid Rank Slope 2 B 1 16.9 65 6 I D 1 16.9 A 2 13.3 3 C 2 13.3 -- As rec'd 2 13.3 13 K 3 11.3 4,405,727 17 18 '___________TABLE 3-continued _________ RANKING CHEMICAL TREATMENTS THROUGH THEIR EFFECT ON FLEXURAL MODULUS Example Solid Rank Slope 14 L 3-4 11.3-6.9 Line I of FIG. 1 shows the effect of untreated mica. Increasing amounts caused a continuous decrease in impact resistance. Line II represents the effect of using a treated mica of 5 the type prepared in Example 1 (Solid A). Increasing amounts still caused a steady decrease in impact resis tance, but at a lower rate than untreated mica. Deposi Two variables which influence mechanical properties tion of additional block copolymer on the mica treated of a flake reinforced composite are (1) the effective as in Example 1 (Examples 12 and 13) resulted in some aspect ratio for the overall dispersion of flakes, and (2) 10 further improvement in impact resistance. the degree of adhesion at the matrix-filler interface. By Lines III, IV and V demonstrate still greater im a mathematical analysis which utilizes flexural modulus data taken from a homologous series of composites, one provements in impact resistance, obtained with mica treated as in Examples 2, 6 and 4; respectively. Lines IV can derive two parameters, a and >3, representing the and V demonstrate that with amounts of these rein effective aspect ratio of a dispersion and slip resistance 15 forcements up to about 2 and about 5%, respectively, of the polymer matrix parallel to the interface, respec the impact resistance is better than that of the polymer tively. matrix itself. Making use of a modification of Riley's theory of It will be recalled that it had been found that when parallel plate reinforcement, a known volume fraction using "as received" mica, the decrease in impact of mica, and measured elastic moduli, one may calculate 20 strength due to added filler was not affected by size a single parameter ft, which can be shown to be related difference from normal 60 to 320 mesh. This is appar to the above parameters by the formula: ently not true for reinforcement treated according to this invention. Lines V, V' and V" represent mineral n = 2ol/3l substrates of 60 mesh, 200 mesh and 320 mesh, treated in 25 the same manner with the same block copolymer (Ex Provided one member of a homologous series of com amples 4, 3 and 5). The 60 mesh reinforcement is clearly posites has nearly perfect adhesion, one may assume superior, although each is superior to untreated mica. fi = 1 for that composite, and calculate a for the disper FIG. 2 is a plot of notched Izod impact vs. flexural sion. Knowing a, one then proceeds to calculate fi modulus (an indicator of stiffness) for a number of filled values for the other members of the group. 30 compositions. The slip resistance fi of the polymer matrix at the In each case, the polymer matrix was a commercial interface with the reinforcing flakes was determined for high impact polystyrene (P-4). In each case, the mica a high impact polystyrene matrix containing 3.4% by used was M-l and the glass fiber M-4. volume of each of the following: mica flakes chemically Line I of FIG. 2 shows the effect of addition of un modified in accordance with this invention by co 35 treated mica or untreated glass fibers. Increasing valently bound S-B-S block copolymer 0-1; the same amounts caused a continuous decrease in impact resis mica as received; and the same mica flakes coated by tance as stiffness increased. The concave shape of the precipitation from solution with 10 and 20% by weight curve shows that the smaller amounts of untreated mica of the same block copolymer employed in the chemi or glass are especially effective in causing reduction in cally modified mica. The results are shown in Table 4. 40 impact. It is seen from the fi values in Table 4 that chemical Line II represents the effect of using a mica of the bonding of a block copolymer to the mineral substrate is type prepared in Example 1. Increasing amounts still greatly superior in providing a tight linkage between caused a steady decrease in impact resistance with in reinforcement and matrix to coating of the same mineral creasing stiffness, but at a lower rate than the untreated reinforcement with the same block copolymers. 45 mica. The line is straight and lies above the line for TABLE 4 untreated mica, except at its lowest point. Line III represents the results of using a mica of the Reinforcing Composition e a type prepared in Examples 2, 6 and 7, and of glass fibers Mica as received Mica with about 0.1% w block copolymer co>valently bonded Mica coated with 10% block copolymer Mica coated with 20% block copolymer 0.63 126 of the type prepared in Example 8. Such treated rein 1.00<") 121 50 forcement, used at low concentrations, permit produc 0.66 126 tion of significantly stiffened polymer without loss of impact strength and even with a slight gain. 0.79 126 In the preparation according to Examples 1, 7 and 8, S-B-S block copolymer was a commercial polymer of *Jlby definition, ax explained in text. 55 somewhat higher molecular weight than S-B-S com pound 0-1. It was a nominally about 16,000-69- In studies of the effect on impact strength of adding 00-16,000 polymer. from about 3 to about 7.5% of "as received" mica flakes Line IV shows a significant increase in impact to HIPS matrix P-4, it was found that, as expected, strength when using a reinforcement of the type pre impact strength decreased with increasing amounts of 60 pared in Example 3 (but using mica substrate M-l, as in filler--from 1.5 ft-lb/inch of the matrix itself to about the other mica reinforcement of FIG. 2) in a concentra 0.6 ft-lb/inch with about 7.5% filler, but the decrease tion of 1.5%; some increase in impact is observed at a was independent of the size of the mica flakes--from 60 loading of 3.4%. The flexural modulus of the composite to 320 mesh. can be increased to 500,000 psi before the impact FIG. 1 is a plot of notched Izod impact vs. volume 65 strength decreases below that of the unfilled polymers. percent reinforcing composition. In each case the matrix was a commercial high impact polystyrene (P-4). The solid mineral substrate was mica. FIG. 3 is a plot of the ratio of the flexural modulus of reinforced composites (Ec) to the flexural modulus of several unreinforced polymer matrices (Em). The sev- *V+u->,/4,/ 19 20 eral lines represent different volume fractions (0%, present in a concentration of 1-30 parts by weight per 1.5%, 3.4% and 8%) of the same reinforcement (of the 100 parts of the matrix polymer. type of Solid C') in different polymer matrices (P-2, P-3, 5. A composition according to claims 1, or 2 wherein P-4, P-5 and P-6). said chemical bonding consists of covalent Table 5 shows mechanical properties of injection 5 molded polypropylene homopolymer (P-1) with and without the grafted reinforcements of this invention. The homopolymer itself at room temperature has a notched Izod impact of 0.42 ft/lbs and a flex modulus of II M--O--C-- or M--C--bonds, ii 190,000 psi. Adding untreated mica raises the flex mod- 10 ulus to about 510,000 lbs and lowers the Izod impact wherein M represents silicon, aluminum or other metals strength to 0.34 ft/lbs. In contrast, if mica with S-B-S of groups 2 to 8 of the Periodic Table; M and O are copolymer 0-1 grafted to the surface, as prepared in components of the surface layer of said mineral mate Example 1, is blended with the polypropylene at the rial; and C is a component of said organic molecules, same volume percent level, the modulus is 460,000 lbs. 15 connected to at least one polymer-interactive group. per square inch, almost as good as the untreated mica, 6. A composition according to claims 1, or 2 wherein but the imact strength 0.52 ft/lbs, represents an increase said chemical bonding results from reaction between over the homopolymer as well as a significant increase surface oxygen or hydroxyl groups of said mineral com over the results with the untreated mica. Since the mica ponent and double bonds of said organic molecules. was present in each sample at 5% volume level, but in the case of the grafted mica some weight of the rein forcement was made up by the graft organic materials, 7. A composition according to claims 1, or 2 wherein said chemical bonding consists of the amount of mineral actually used was slightly less in the treated than in the untreated mica. This accounts for ^ most of the decrease in stiffness relative to untreated mica. II II --Si--O--C-- or --Si--C--bonds, II II TABLE 5 MECHANICAL PROPERTIES OF PP/MICA COMPOSITES wherein Si and O are components of the surface layer of 30 said mineral material and C is a component of said or Notched ganic molecules. Rein forcement Type* Flex Modulus I05 psi Tensile** Modulus I05 psi Tensile Strength psi Izod Impact ft-lb/in. 75* F. -40* F. 8. A composition according to claim 5 wherein said mineral reinforcing material is a platy material of the group consisting of mica, asbestos, talc and clay, having None 1.9 2.1 3740 0.42 0.31 35 an aspect ratio in the range from 20-200, and is present Untreated Mica Example 1 5.1 4.2 3850 0.34 0.28 4.6 4.2 3890 0.52 0.34 in a concentration of 1-30 parts by weight per 100 parts of the matrix polymer. Mica present at 5% volume levels. 9. A composition according to claim 6 wherein said ,rTexude properties determined at 0.05 in./min; flex modulus determined at low mineral reinforcing material is a platy material of the stress levels under static load. 40 group consisting of mica, asbestos, talc and clay, having What is claimed is: 1. A reinforced thermoplastic composition compris ing a thermoplastic polymer matrix having intimately distributed therein a chemically modified mineral rein forcing component, wherein said matrix is a non-elastomeric thermoplastic poly(vinylarene) and said rein forcing component is a particulate or filamentary min 45 an aspect ratio in the range from 20-200, and is present in a concentration of 1-30 parts by weight per 100 parts of the matrix polymer. 10. A composition according to claim 7 wherein said mineral reinforcing material is a platy material of the group consisting of mica, asbestos, talc and clay, having an aspect ratio in the range from 20-200, and is present eral polymer-reinforcing material having chemically bonded to its surface by covalent chemical bonding a thin layer averaging about 5-500 Angstrom in thickness 50 in a concentration of 1--30 parts by weight per 100 parts of the matrix polymer. 11. A reinforced thermoplastic composition compris of silicon-free and heavy metal-free organic molecules ing a thermoplastic polymer matrix having intimately which contain at least a substantial segment capable of distributed therein a chemically modified mineral rein interacting with said matrix polymer to provide im forcing component, wherein said matrix is a non-elas- proved adhesion, said segment having an average mo 55 tomeric thermoplastic organic polymer and said rein lecular weight at least about one-sixth that of said ma forcing component is a particulate or filamentary min trix polymer. eral polymer-reinforcing material having chemically 2. A composition according to claim 1 wherein said bonded to its surface by covalent chemical bonding a polymer matrix is a polymer of styrene. thin layer averaging about 5-500 Angstrom in thickness 3. A composition according to claims 1, or 2 wherein go of silicon-free and heavy metal-free organic molecules said mineral reinforcing material is glass, mica, vermic- which contain at least a substantial segment capable of ulite, asbestos, talc, clay, silica gel, alumino-silicate or interacting with said matrix polymer to provide im silica and is present in a concentration of 1-30 parts by proved adhesion, said segment having an average mo weight per 100 parts of the matrix polymer. lecular weight at least about one-sixth that of said ma- 4. A composition according to claims 1, or 2 wherein 65 trix polymer, and said chemical bonding resulting from said mineral reinforcing material is a platy material of reaction between surface oxygen or hydroxyl groups of the group consisting of mica, asbestos, talc and clay, said mineral component and double bonds of said or having an aspect ratio in the range from 20-200, and is ganic molecules. *T,*tUJ, / L. / 21 22 12. A composition according to claim 11 wherein said asbestos, talc, clay, silica gel, alumino-silicate or silica polymer matrix is a polyolefin or poly(vinylarene). and is present in a concentration of 1-30 parts by weight 13. A composition according to claim 11 wherein said per 100 parts of the matrix polymer. polymer matrix is a propylene polymer. 17. A composition according to claim 16 wherein said 14. A composition according to claim 11 wherein said 5 mineral reinforcing material is a platy material of the polymer matrix is a polymer of 1-butene. group consisting of mica, asbestos, talc and clay, having 15. A composition according to claim 11 wherein said an aspect ratio in the range from 20-200, and is present polymer matrix is a polymer of styrene. in a concentration of 1-30 parts by weight per 100 parts 16. A composition according to claim 11 wherein said of the matrix polymer. mineral reinforcing material is glass, mica, vermiculite. 10 ***** 15 20 25 30 35 40 45 50 55 60 65