Document 50OQQyJq5pMOqGv2wBODzgvX8

FILE NAME: Drywall Spackling Compounds (DWSC) DATE: 1974 Sept 10 DOC#: DWSC048 DOCUMENT DESCRIPTION: Patent - Joint Cement Compositions JHN-J-cMKD l i : U h ' hKUn: T: 14108894944 P: '4 U nited States Patent Office 3,835,074 Patented Sept. 10, 1974 2 covering taped joints. Most commercial formulations are 3J35.V74 within the following concentration ranges: JOINT CEMENT COJVWOSmONS Calcium carbonate. 190 to 350 p u ts by weight A rnaud J. Desearais, New C arte, DeL, anhraor lo Mica, 30 to 90 parts by weight. Hercules Incorporated, Wihniagtoi, Del. 6 Clay, 0 to 100 p ern by weight. N o Dsuwtog. te Apr. 26,1973, Ser. No. >64,719 Binder, 20 to 44 parts by weight l o t CLC0f 37/16,4 $ m U A a 260--17 9C tata If the prodnet is to be sold us a ready-mlx formulation, water in the amount o f about 30 to 4046, based on the 1 total weight o f the dry ingredients, is added and thorough ABSTRACT OF THE DISCLOSURE ly mixed. All compositions within the limits just described Joint cements suitable for use with plaster wallboard e re suitable for manual application by troweling. When aro disclosed wherein the asbestos customarily used to they a n to be applied mechanically, additional water la irmappteacrtedwbhayt.ea.r wbiantde7irn7-ignii.snporllu.o.bpklele.r,t iafeibswroa.,,nu,,ds peeudoplasticity a bydraxyethyl eellu- .1.* added at the job rite just prior to use. ^ T1hnieeQvceoenlltiuinolooDsemodeernivantivoes wmhiecnh cfaibnroobuecs emmoiaptlweoryivaeudl, mians ius0` distinguished from tho conventional fibrous hydroxyethyl cellulose of commerce which is water-soluble. W at in This invention relates to compositions useful as joint solubility is assured cither by maintamiog the M.S. at a sineagliinng, me-agtnerrieaslsidteonrtiathl eanindstaolflfaictieonbuoifldwinagllbcoonarsdtrupcatnioenl. 20 ketrhwyllaevtieoln, Lteec.,hbneiqlouwesaWbohuicthIpXrodour cbeyathneonuuseniofofrhmyldyrosxuyb- M ote specifically, U raters to such compositions wherein stituted product. The water insolubility is a critical factor a cellulose derivative is employed to impart desirable properties thereto. in (he performance of the hydroxyethyl cellulose as an tfte sto i substitute, a water-soluble material such us eon- Since the end o f th e secoad World W ar, the use off ok ventioual hydroxyethyl cellulose, a t economical cancanwa.1llIL b> o_a__i_d1 hU.a__ s_ all 1b__ u.t Jd-i_ s_p_Il_a__ c_eid_lp__ l_ a__ st>_e__ r- in erec-atit_ o__ n o_df "v t-rstio----a--W leSvels, would n ot impa.r4t athteek eaw onadJaeSteanam ey, -nae-edJeadJ interior walls in tba construction of buildings. Wallboard for the pseudoptasticiiy normally obtained with asbestos. is generally installed in 4 x S foot panels which are nailed The above paragraph must not be taken to mean that and glued to the studding of the wall and fitted together no water-soluble hydroxyethyl cellulose is to be employed. until the entire section of wall a covered. The joints 90 Waicr-folubTe hydroxyethyl cellulose is frequently included When sections o f the board a n butted together are cov- -a-s---a--t-h-i-c--k-e--n-e--r*-in l--ime`s--tone*b--aseJd joint--c-e--m--e--nt*s ~anAd --can a n d with tape and then taped joints and all nails are be so used in the compositions of this invention. It is only covered with a joint commit o r "spackling" compound the hydroxyethyl cellulose employed in substitution for which, upon hardening, can be sanded smooth so that asbestos that need be water insoluble. it is imperceptible under paint or wallpaper. 3S T o duplicate properties o f conventional joint cements, Joint eements heretofore employed with wallboard have the concentration o f the water-insoluble hydroxyethyl cel contained a resinous binder, limestone, day, mica and asbestos the principal Ingredients which are mixed with lulose can be from about an squat quantity to Ms that of the asbestos being replaced, depending on the M.S. water to form a dope. Asbestos is included m these for- of the hydroxyethyl cellulose used. If the MIS. o f tbs mutations for several purposes. & imparts lubrieity, work- go hydroxyethyl cellulose is in the range o f 0.15 to 0.6, the ability, w ater bindings and pseudoptasticiiy to die wet mix concentration employed can be in the range of 1% to and, being fibrous, provide* reinforcement of the cement on drying. W baaed on the dry weight of the formulation. Due to the superior water-binding capacity o f tbc cellulose de- Kceantly disclosed evidence that certain types of as. TivB,iv hBVi0 M.S. in * * * <* ** l 2 * " " besto, may have carcinogenic characteristics has prompted , L * t Wbc* * * ^,X d t "7 ibis rea- s m , an eflOrt U uow tm der way to find substitutes to re- place asbestos in most o f its present applications. to ^ W 9 * based on the total dry weight off the formulation. Employing conventional joint cement recipes, gD the additional weight of asbestos, not replaced by cellulose derivative. Is replaced by additional timestone or mica In recent work by the jitslanr inventor, it has bear so that the total weight o f product remains the same, found that cellulose derivative* can be used as a replace- A* suggested previously. It is important that tbc by- ment fo r asbestos In joint cement. More specifically, this droxyethyl cellulose be in fibrous form. F or best results invention relates to joist cement compositions based on gg the fiber length should be between about 0.03 aud 0.007 a resinous binder, mica, clay, and limestone a t major dry inch. If the fiber length becomes too great, the resulting components, along with a fibrous, water-insoluble by- cement composition is curdy and not satisfactory. On the droxyethyl cellulose having an M.S. between about 0.15 other band, if toe fibrous form is lacking the water- and 1.4. Joint cements are maketed in fully formulated. binding capacity of the hydroxyethyl cellulose is not suf- rctdy-io-use form, Le., already containing water, and as da ficient to reproduce the properties of conventional joint a dry powder to which water is added at the time of use. cements. The invention includes such dry powder* as well a* the In some cases, the hydroxethyl cellulose alone can give fully formulated cements. Joint cement compositions o f th e composition sufficient body fo r application to a vertical this invention are substantially identical in performance wall without sagging or melt-down. In other eases, a to those which are presently available commercially and, ** structure additive can be added to increase the body to based on current price levels, they are competitive in the necessary level. Materials useful as structure addi- price. fives for this purpose include, e.g., cellulose fibers in In commercial practice the concentrations of die prin- various fo rm , treated days, and porous stone flour. When eipa] ingredients can and do vary widely between sup- structure additives of this type are added, they normally pliers and depending on the intended cud use, Le., whether 70 replace a portion of one o f the inert fillers, be., limestone, it is for patching holes, covering nail pops, or for initially mica, o r day. l i iJ L ir rrcuru IUi ri 8,886,074 3 4 The resinous binder normally s coalescable vinyl The latex binder was a $3% by weight aqueous disper material, preferably poly (vinyl acetate) which upon dry sion of polyfviayl acetate) containing a plasticizer. The ing or airing o f the cement fonn* a thin m ain* to hold dispersant was a polymerized sodium salt of a sulfonic tbe d a y , limestone, etc. When a fully formulated mix is acid sold under the trade name D axad 30. The defoamer being prepared, the binder is usually added us aqueous ,, was n silica dispersion io a hydrocarbon solvent. The latex. In the case of dry mixes it i* added as spray dried preservative was a mercurial fungicide compound. latex particles. Other m atertala useful as the binder in clude, e.g., starch, casein, polyacrylamide, and copolymers Examples 1 to 11 of acrylamide and acrylic acid. The procedure and the formulation set forth for the In addition to the principal ingredients mentioned 0 control example were repeated using the following insol above, a typical joint cement will frequently also contain uble hydroxyethyt cellulose modifications In place of as a small amount of a dispersant, a defoamer, a preserva bestos. The flue, fluffy fibers are all within the 0.03 to tive and a thickener. 0.007 in. range--i r , they passed through a 20-mesh In the following examples, the invention is illustrated. screen and were held on 80-mtsh. Tarts and percentages are by weight unless otherwise indicated. The following general procedure was employed to Example 1 mi* tho ingredient*. Asbestos Was replaced with 48 grains Of hydroxyethyl In preparing a ready mix formulation the water and cellulose having M.S. 0.32, in the form of fine, fluffy fiber, binder latex were charged to a mixing apparatus and having water retention power of 10 g./g. mixed for a short time before the dispersant, defoamer, gp and preservative were added. The dry ingredients (lime Esample 2 stone, mica, clay, hydroxyethyl cellulose, and structure Asbestos was rcplcced with 48 grams of hydroxyethyl additives, it used) were dry Mended and added incre cellulose having M.S. o f 0.4 in the form of fine, fluffy mentally to tbe stirred liquid. After the last of the dry fibers having water retention power o f 10 g./g. ingredients was added, (he mix way stirred for about an- as other 10 minutes at low speed with occasional stopping Example 3 to scrape down the aides of the bowl. ' T o characterize the products prepared in the examples, the following tests were used. Asbestos was replaced with 24 parts of limestone and 24 parts o f hydroxyethyl cellulose having MLS. of 0.4 in the form o f fine, fluffy fibers having water retention power VISCOSITY Measured in Brabender units (B.U.) ASTM 474-67, Sections 2 and 3. 40 determined by of 10 g./g. Example 4 Asbestos was replaced with 44 parts of limestone and 4 parts of hydroxyethyl cellulose having M.S- of 0-82 >'n CRACKING 39 tbe form o f fine, fluffy fiber* having water retention power Panels were dried in an essentially vertical position with a current o f sir from a 14 inch oscillation fan forced across their face from about 30 inches for 43 minutes. o f 19 g./g, Example 5 Asbestos was replaced with 40 purls of limestone and The panels were then allowed to dry overnight in the go 8 parts of hydroxyethyl cellulose having M 3 , o f 0.82 in verticel position without the air current. Ratings were the form o f fine, fluffy fibers having water retention power assigned subjectively as: none (N ), very slight (V S.), of 19 g./g. slight (S ), moderate (M ), or heavy (U ). Exempic 6 MELT-DOWN 4j Panels of the cement about 4" x 5 " x 16" were east M eltdow n wae observed as sag a t the edges of the panels. Ratings--Excellent: structure of east panel is retained with sharp edge*. Slight: Edges of panel are slightly rounded. Moderate: Edge* are slightly more rounded. 80 Asbestos was replaced with 40 parts of limestone and 8 ports of hydroxyethyl cellulose having M S of 0-78 in the form o f fine, fluffy fibers having water retention power o f 18 g./g. Example 7 Asbestos was replaced with 42 parts of limestone and Poor: Edges o f panel are smooth and tapered. ADHESION 6 ports o f hydroxyethyl cellulose having M.S. o f 0.78 in the form o f fine, fluffy fibers having water retention power of 18 g./g. By ASTM test C 474-67. fiS Example 8 CONTROL EXAMPLE Asbestos wa* replaced with 42.7 parts of limestone and 5.3 of hydroxyethyl cellulose having 0-88 M.S. m the T his control example is intended to illustrate the prop form of fine, fluffy fibers having water retention power erties o f a conventional joint cement employing asbestos of 20 g./g. as a water retention aid. The following standard joint CO Example 9 cement formulation was prepared using tbe procedures set forth above. Asbestos replaced by 40 parts of limestone and 8 part* of hydroxyethyl cellulose having an M.S. of 0.81 in the form of floe, fluffy fibers having water retention power lim estone (9898 C a C O j ) ____________ 23(1 o f 19 g./g. M3ca (325 m e s h )________________ ..___ _________ 76 M Example 10 Latex b in d e r_____________________________ D ispersant 61 Asbestos replaced by 48 parts o f hydroxyethyl cellulose 4 having ao M.5. of 0.82 in the form of fine, fluffy fibers Preservative ______________ . . . . . . ________ . . . . 0.2 having water retention power o f 19 g./g. W ater _____________ 280 70 Defoamer _____________ _____ __________. . . ____ 4.6 Example 11 Hydroxyethyl cellulose1 ________ . . . . . . _______ 2 Asbestos (5 -1 0 0 0 ,,) ---------- . . . _________ . . . . . . . 48 Asbexlo* replaced by 48 parts a t hydroxyethyl cellulose having an M-S. of 0.15, having water retention power of iffiU tw luM c grade. M.S. 1,8. 8ooe ep*. viscosity la IK . . 5 g ./g . prepared by fibrillation o f a pressed sheet into aqaeeus wlutloo. * fibers greater than 0X133 in. j m - jt i- G X K i'j i i - i c r rrxuri. iu: ^ i H u y ^ y ^ 3,835,074 5 6 The properties of the above Control Example and Ex consistency, exhibited slight cracking and very slight melt amples ] through 11 are recorded in the following table. down. Xuwvls Melt- number viicosttr o S CncUng aewn Apfattlen Appunnce Examples 12-17 Example 18 The following ingredients were dry mixed by tumbling: Using the recipe set out above, additional joint cement Parts compositions were prepared in which some o f the asbt SO Limestone ____________________ .__ _____,, ____ 29 toa waa replaced wtth a mixture o f low K 5 . bydroxyethyl cellulose, adeuiar atlnpnlgitc clay and talc and the re Q ny 76 mainder with additional limestone. Binder1 ___ ,-- ____ ___ _____ _______ _____ 34 S3 Hydroxyethyl cellulate * --. . . . . . . . . ____________ 2.5 Hydroxyethy) cellaloes1 ________ 4 Example 12 sty(iteyl acetate) latex. One part of bydroxyethyl cellulose having 0.B2 M.S,, 2 parts clay and 4 parts talc. Product was slightly grainy, but exhibited only slight cracking and excellent melt down. Example 13 One part bydroxyethyl cellulose having 0.41 M S . 2 parts clay and 9 pans laic. Product had smooth, creamy consistency and exhibited only moderate cracking and alight melt-down. Example 14 _ d n b R f t f t f f t t l f e W rateatloa or 19 X./g. SO The dry blended ingredieau were mixed with 210 parts of water, the mix was allowed to slake for 20 minutes and was then mixed again to a uniform consistency and eval uated as in foe previous examples. Results were as fol lows: 90 Viscosity _________________________ 560. Density ----------------------------------------- 12.8. C racking _______________ _______ __ N. Melt-down _______________________ V.S. 40 Adhesion ______ ________ _________ _ Satisfactory. A ppearance------- --------------------------- Smooth-creamy. S tru c tu re ____ _________________ ,___Good. One part hydroxyuthyl cellulose having 0.53 M4L 2 W hat I d aim and desire to protect by Letters Patent 1: 1. A joint cement composition consisting essentially of parte d a y and 9 parts talc. Product bad smooth creamy 45 a Goaiescab! vinyl resin binder, mica, d a y , and hnwstonc consistency and exhibited no cracking and slight m elt as its principal dry ingrdients and containing about 0-5 down. Example 15 to 9% by weight, based a n foe total weight o f foe dry components, o f fibrous, water-insoluble bydroxyethyl cel lulose having a bydroxyethyl M S. o f about 0.6 to 1.2. 69 2. Th composition o f claim 1 wherein the hydiraxyOne part hydroxyethy! cellulose having 0:63 M.S., 2 ethyl cellulose has a bydroxyethyl M.S. of about 0.6 to parte clay and 9 parte talc. Product had smooth, creamy consistency, exhibited no cracking and slight melt-down. 1.2 and is prescat fat a concentration o f about a s to 1,5% . 3. The composition of daim 1 wherein the bydroxy- ethyl cellulose has a bydroxyethyl M i . o f about 0.15 to 8* 0.6 and is present i s a concentration of about 1 to 9% . Example 16 One p art bydroxyethyl cellulose having OS M.5., 2 parte clay and 9 parte tale. Product had smooth, creamy slightly more viscous consistency, exhibited no cracking 60 and very slight melt-down. 3,382,119 3.411,926 3,044,973 References Cited UNTIED STATES PATENTS 5/1968 H e n k el_______________ 2 6 0 -1 7 11/196 O o g e k _______________ 106--214 7/1962 S eg ro ____________ 260--39 R 2,816.872 12/1957 Y o u rte e - ____________ 2 6 0 - 1 J Example 17 66 THEODORE MORRIS, Primary Examiner One part hydroxyethy] cclluloao having 0.82 M.S,, 1.2 part* d ay and 52 parte talc. Product had smooth, creamy 106-- 141 U S. CL XJK.