Document pm3Vx2pR84Z52q873gvNp5N56
TECHNICAL SERVICE REPORT by
D. H. Reed
L
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Li'C-CrATTLVlO. CRAiIA
The Use of Calidria SG-210 Asbestos in
Dry or Ready-Mix Tape Joint Compounds
Union Carbide Corporation Chemicals and Plastics
Research and Development Department South Charleston, West Virginia July 19, 1971
UCC 025630
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What Asbestos Fibers Do in Tape Joint Compound
Asbestos performs a number of functions in commercial ready and drymix tape joint compounds. The primary function is to form the backbone or "web" for the inert fillers and film formers to associate with. Upon drying, or film cure, the asbestos adds a significant amount of dimensional strength to the applied materials. The influence of asbestos on other formulated performance properties depends upon the particle size and concentration level with respect to the other inert fillers.
Asbestos functions as a secondary bodying and thickening agent, in wet formulations, via the water absorption capacity of the fiber. In this capacity, it contributes to the reduction of product density in relationship to the concentration level employed in the formulation. This comes about as a result of the increased water demand. The water absorption efficiency is a function of the particle size and other physical properties of the asbestos.
Finally, perhaps more than any other filler, asbestos contributes signi ficantly to the formulated compound smoothness, cratering, and "wet edge" properties. This is because of the fibrous nature of asbestos particles. In like manner, both the asbestos particle size and concentration level will determine, to a large extent,, the smoothness of the feathered edges.
On the negative side, of the variety of inert fillers employed in a joint compound, asbestos and clays contribute most to the nailhole cracking problems. In the process of water absorption, asbestos particles swell. On drying, these particles shrink with the release of water. Although the swelling is necessary for good product body, asbestos at too high a level can be the single largest con tributor to thick layer joint compound shrinkage cracks. Product particle size uniformity is therefore of utmost importance in regard to reproducible built-in properties of a formulated tape joint compound.
Special Properties of "Calidria" Asbestos
Most asbestos materials, marketed commercially for use in tape joint compounds, contain rock dust and other abrasive type fillers, that have no specific desirable effects on joint compound performance. "Calidria" SG-210 and SG-13 0 asbestos are produced by a proprietary manufacturing process that yields essentially a pure asbestos fiber content. The SG-210 product is preferred for ready-mix smoothness and water absorption efficiency. Another feature is the unique shape and physical structure of the "Calidria" asbestos fibers. The micro size particles are actually "fibrils" and the respective stems are hollow; hence, the fibers have a tremendous water absorption capacity. In like manner, there are more "active sites" for other inert fillers to associate with, in formulated film formation. As a result, "Calidria" asbestos generally goes twice as far, on a pound for pound basis, as the Canadian and other commercial types used in tape joint compounds. It is these physical properties that enhance the wet joint compound workability and performance properties mentioned above.
How to Use "Calidria" Asbestos in Tape Joint Compounds
"Calidria" asbestos can be used in dry or ready-mix compounds, with very little change in formulation parameters. Since "Calidria" SG-210 will go twice as far as similar Canadian types, a good substitution starting point is
UCC 025631
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one-half as much. The formulation weight difference is best made up with mica or calcium carbonate dry filler.
The typical product characteristics of "Calidria" SG-Z10 and SG-130 are listed in Table I. The SG-130 is shown, because it can be used in formu lations where surface smoothness is not as desirable as that obtained with SG210 asbestos.
The relationship of ''Calidria" asbestos fiber physical properties to subsequent oil or water demand characteristics are depicted in Figure 1. In Figure 1, these absorption characteristics are compared to typical commercial grades regularly employed in joint compounds. The data, in Figure 1, show that a good ''Calidria" asbestos substitution starting point is at about 50 percent, by weight, less than other typical commercial asbestos, without changing signi ficantly the original formulation water demand (i.e. one-half the amount of other sources). The weight differences can be made up with either additional amounts of calcium carbonate or mica fillers. The latter is preferred with respect to ready-mix water demand and good naiihole cracking resistance. No other changes are necessary in the formulation.
Three suggested tape joint compound ready-mix formulations are listed here to depict the use of Calidria SG-210 asbestos. These are listed in Tables II, III, and IV. These formulations differ in both the ratio and types of additives, to introduce desired formulation end-use properties. For example, the suggested bedding coat material. Table II, does not have as smooth a dry surface, but should fill the primary requirements of good tape adhesion and a minimum amount of thick layer cracking. The general purpose formulation. Table Ilf, should depict good overall working properties and have better wet edge and surface smoothness than the bedding coat material. A topping coat product, Table IV, should exhibit a minimum amount of volume shrinkage,(note the higher density), have exceptional surface smoothness, and wet edge. In addition, a minimum amount of sanding is desirable for topcoat materials. In actual practice, the bedding and top-coat materials are giving away to the general purpose types.
If Canadian or other types of asbestos were used in these suggested formulations, it would be at double the concentration level indicated to achieve essentially the same water demand. In like manner, the higher asbestos level dry compound surface smoothness would not be as evident with everything else being equal.
The formulations listed here are merely suggested ones. Experienced tape joint compound formulators have their own source of fillers and usually employ other ingredients to fit particular geographic conditions and subsequent end-use requirements. In the case of asbestos, the choice is generally between the Canadian and ''Calidria" types. It is a matter of grades employed, efficiency, and effect on compound workability and dry-film cratering. In these important areas, "Calidria" SG-210 asbestos shows extremely good properties in either dry or ready-mix tape joint compounds.
UCC 025632
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TABLE I UNION CARBIDE CALIDRIA ASBESTOS
Typical Product Cher actcriatics
SG-130
SG-210
Reflectance (G.E. Photovolt) Contained magnetite Alkalinity (as 7. of Na2^) pH (57. aqueous slurry) Surface area (BET)
6811 2% Max. 0.05-0.06 8.5>-9.5 50- 60
Oil Adsorption (I>0? 2/100$ asbestos) Wet Bulk, settled vol. (mi.)
10g/250 ml./l hr. Dry Bulk (/ft.3) Water absorption (vt. 7. in filter cake) Size dintribution (Cumulative 7. retained)
Wet Screen rash size 100 200 325
90-100
200 7-8 55-60
110-120
220 5-6 62-65
5 Trace
17 3
23-32
10-15 i
-- _________________ I
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TABLE II
UCAR LATEX WC-130 OR 131 SUGGESTED BEDDING COAT TAPE JOINT COMPOUND
(13-DHR-18)
Ingredients and Order of Addition(a)
Pounds Gallons Lbs/100 Gal % by W
1. tfa ter 2. CELLOSTZE TJC Thickener,
Union Carbide 1 . Bncteriastat "Dowicide" A or
similar 4 . Dispersant, "Daxad,'-30, (25% H) ,
Dewey and Almy
5, UCAR Latex WC-130, (58% 5),
Union Carbide 6 . Dibutyl Phthalate, Union Carbide 7. Ethylene Glycol, Union Carbide 8. Calidria Asbestos SG-210,
Union Carbide 9. Mica P-80-F, Western Mica 10. Clay, ASP-400, Minerals and
Chemicals, Phillip 11 . Calcium Carbonate, No. 1 White
Thompson-Weinman 12. NOPCO PD #1 Anti l oam
Nopco Chemical Company
1932 20
8
64
414
24 40 180
840 160
2468
4
232.43 1.72
0.74
6.53
44.66
2.75 4.30 8.45
36.68 7.44
109.20
0.55
424.16 4.41
1.72
14.01
90.94
. 5.23 8.74
39.62
184.34 35.04
542.17
0.88 -
31.39 0.32
0.13
1.04
6.73
0.39 0.65 2.92
13.66 2.60
40.11
0.06
6154
455.45
1351.26
100.00
Note
fa) Mixed 1.5 to 2.0 hours in a one-gallon Baker-Perkins, Sigma Blade Type Mixer, at 79 r.p.m.
Typical Properties
Water Content. Pounds/Gal 1 on Bra bender Viscosity Adhesion to Wall hoard Tape Nailhole Cracking Resistance Sa nda hi 1 i ty
35.1% 13.51 700 B. U. 100% 99% Good
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TABLE III
UCAR LATES WC-130 OR 131 SUGGESTED GENERAL PURPOSE TAPE JOINT COMPOUND
(13-DHR-68)
Ingredients and Order of Addition(a)
Pounds Gallons Lbs/100 Gal % by Wt
1. Water
2. CELLOS1ZE TJC Grade Thickener,
Union Carbide
3. "Dowicide" A, or similar
bacteriastat
4. ,,Daxad"-30, dispersant (25% 2)
5. UCAR Latex 131 preplasticized
(59% T) , Union Carbide
6. Ethylene Glycol, Union Carbide
7. Calidria SG-210 Asbestos,
Union Carbide
8. Mica, AA, Thompson-Weinman
9. Mica, P-80-F, Western Mica
10. Clay, ASP-400
11. Calgon, Water Conditioner
12. Talc, Asbestol or A-200
13. No. 1 White Calcium Carbonate
1932 20
8
64 447
40 180
420 420 100
20 40 2472
232.43 1.72
0.74
6.53 48.48
4.30 8.45
18.34 18.34
4.65 3.12 1.69 109.38
421.67 4.41
1.73
14.01 97.55
8.74 39.19
91.60 91.60 21.71
4.35 8.77 539.69
31.35 0.32
0.13
1.04 7.25
0.65 2.92
6.81 6.81 1.62 0.32 0.65 40.13
6163
458.17
1345.02
100.00
Note:
(a) Mixed 1.5 to 2.0 hours in a one-gallon Baker-Perkins, Sigma Blade Type Mixer, at 79 r.p.m.
Typical Properties
Water Content Pounds/Gallon
Adhesion to Wall board Tape Bra bender Viscosity Nail hole Cracking Resistance Sa n d a b i 1 i t y
35.1% 13.45
100% 600 T 95% Good
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TABLE IV
SUGGESTED TAPE JOINT TOPPING COMPOUND (13-DHR-4S)
Ir.gredi.enti> ana, Order of Addition'1
Wat e r CELLOSIZE TJC Grade Dov7icide "A,:, 3acteriastat UCAR Latex WC-130 (53% 3) Dibutyi Phthalate Ethylene Glycol Caiiaria SG-210 Asbestos Mica {P-3G-F) Mica (Ser-X) Clay, ASP-400 No, 1 White Calcium Carbonate Talcum Powder (Mailinkrodt) Calgon, Regular
Pounds Gallons
1714 30 8
345 20 40
180 100 400
40 3127 . 40
20
6064
206.21 2.59 0.74
37.26 2.29 4.30 8.45 4.37
17.47 1.86
138.36 1.69 3. 12
428.71
Lbs/100 Gal.
399.81 6.96 1.84
80.47 4.62 9.39
42. 17 23.36 93.20
9.24 729.53
9.24 4.67
1414.50
% by Wt.
28.27 0.49 0.13 5.69 0,33 0. 66 2.97 1.65 6.60 0.66
51.56 0.66 0.33
100.00
Water Content Pounds/ Gallon
Bra bender Viscosity Adhesion to Waiiboard Tape Naiiho^e Crack Resistance Sanda'oility
3 0.66% 14.14
840 3. U. 100% 92% Good
NOTE: (a)
_
.
Mixed i.o-2,0 nours in a onc-galien 3ake r-Perkins, Sigma 3 lade
Type Mixer, a: 79 r.p. m.
UCC 025636
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t
t
It )t
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(SLU9 Ol/dOQ |U) NOIldHOSGV 110
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FIG U R E 1
I. AT IONSKIP BETWEEN WATER G OIL ADSC) CAPACITY OF SOME ASBESTOS PRODUCT
FOR TAPE JOINT ADHESIVE FORMULA'!'10
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UC 14-9-2
INTERNAL CORRESPONDENCE
PETALS Dl VIS! O N
RfciOtik ViuiiS
UUI - a 1978
UNfON CARBIDE KING CITY, CA.
P. 0. BOX 579 -4625 ROYAL AVE., NIAGARA FALLS, NEW YORK 14302
ro{Name) Mr. r_ e. Byrne, Jr.
Division UCC-Metals Division Location Niagara Falls, NY
copy to
Messrs.
G. L. Dickson
E. J. Kleber T. P. Norris H. B. Rhodes
File
F. 0. Shortsleeve J. E. Walsh
Date October 4, 1978
Originating Dept.
"Calidria" Asbestos
Answering letter date
Subject
Daubert Chemical
I called Bill Houghton in Oak Brook today to check on orders for RG-110-EX
for Holland.
'
He advised me that "upper management" decided last week to discontinue all asbestos-filled products, with a target date of 12/31/78. He said this applies to domestic and export requirements and was caused primarily by union pressure at their plants and their customers. Their insurance company is also insisting that they stop using asbestos.
I told him we had a similar situation at one of his competitors, but that they were at least giving us a chance to present our side to their board of directors. I offered to do the same but he doesn't think Daubert will accept the offer.
Bill says they have substitute formulations without asbestos which are lower quality and higher cost. He also indicated their filled asphalt business was declining due to higher use of plastisol corrosion coatings which "don't contain asbestos". I chose not to correct him on this.
Daubert has been threatening to stop using asbestos for several years so this may not be the end, but this is the first time I have heard a target date.
JLM:dal
UCC 025638
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UCC 025639
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BUSINESS CONFIDENTIAL
ee; k/^C-
<M ^PROJECT* REPORT
SYNTHESIS OF DMBP SYRUP (2,6 DiMethylol 4-t-Butyl Phenol)
rl. ~ l^e1
i'D
may 9-i M j/7-,
authors:
M. D. Bertolucci
supervisor:
F. H. Ancker
oate:
May 15, 1973
PROJECT NO.: 897M14
file no.:
3651
SUMMARY
DMBP (2,6 DiMethylol 4-t-Butyl Phenol) has been shown to be an excellent interfacial coupling agent for chrysotile asbestos in that its appli cation as a pretreatment markedly improves the mechanical and the thermal stability properties of "Calidria" filled polyolefin and polyvinyl chloride composites. Pretreatment with DMBP, henceforth, enables chrysotile asbestos to be utilized as an efficient reinforcing agent in these resins, applications which so far have been limited to more expensive types of abestos (anthophyllite).
Joint studies with the Mining and Metals Division are in progress to define a manufacturing process for the direct in-line pretreatment of Union Carbide's ''Calidria" (chrysotile) asbestos at King City, California. The preferred process is to add DMBP as a concentrated syrup (i.e. without isolation and crystallization) directly to the asbestos filter cake prior to pelletizing and drying.
The present report describes the reaction conditions and quality . control procedures for synthesizing the DMBP syrup. This information is needed as a basis for engineering and cost studies of the integrated asbestos pre treatment process. The results of the laboratory pretreatment process and asbestos composite property studies will be presented in a separate report.
Research and Development Department Chamicals and Plastics
Union Carbide Corporation Bound Brook, Now Jersey
UCC 025640
2.
INTRODUCTION
The development of coupling agents for chrysotile asbestos based on para-alkyl phenol derivatives has been discussed in earlier reports^'2),
Although it is feasible to apply these coupling agents as integral blend additives during compounding, it has been decided that pretreatment of Union Carbide's "Calidria" asbestos to provide a proprietary reinforcing grade of chrysotile is the preferred business option.
The best composite property improvements in earlier laboratory studies
were obtained by pretreating the asbestos with DMBP from an acetone solution.
Subsequent cooperative studies with the Calidria Group at Niagara Falls have
now shown that DMBP can be added directly to the asbestos filter cake (50%
H2O) as it is prepared for pelletizing and drying in the asbestos refining
process. Due to the fact that asbestos has a large surface area {^--60 m2/
gm), a high level of coupling agent is required (5-10% on dry asbestos).
Since chrysotile is a low cost reinforcement, the cost of the coupling agent
must be as low cost as possible.
.
DISCUSSION
Preparation of DMBP
-
DMBP has been synthesized in the laboratory and in the Bound Brook pilot plant as early as 1959 in connection with studies relating to evaluations in rubber adhesives and as a crosslinking agent for elastomers^ /4) _ jn this process, the isolation and crystallization of DMBP are the most expensive process steps. For the purpose of asbestos pretreatment, laboratory studies show that the use of an unrefined DMBP syrup is at least equivalent to and, in many respects, preferrable to using crystalline DMBP, thus enabling considerable cost savings.
The overall production scheme of DMBP syrup can be summarized by the following reaction sequence.
UCC 025641
r^f -n oj/
3.
^ 7!
H2
(1) ^ (J + NaOH ---------
heat
(~-50C)
O Na
hoch2 2HCH0
heat H65C)
0"Na+ ! ch2oh
cool
C 40C)
h2so4
OH ` HOCH2 1 ch2oh
V
1-1/2 H20 + [H+ + Na+ + S04"] * X H20*
(dil.)
DMBP Syrup
In the laboratory preparation, 96% of the theoretical yield of DMBP was recovered as product in the form of a viscous syrup (p = 1.09 g/cc) which contained 10,9% water. The organic portion of this phase was found to be greater than 95% DMBP by N.M.R. analysis^). The aqueous phase which contains residual acid and sodium sulfate was found to retain approximately 3% syrup, which could be recovered by centrifugation. In addition, the aqueous phase contained products with carbonyl functionality to the extent of 0.07% {i.e, 1.4% based on HCHO). Thus, side reactions such as the Cannizzaro reaction which describes the disproportionation of aldehydes like formaldehyde and is illustrated in equation (2) or the thermal advancement of DMBP to higher molecular weight oligomers as shown in equation (3) do not appear to be significant under the reaction conditions described below.
(2) 2HCHO + NaOH-------------- > CH3OH + HCOO Na+
(3) ^
OH HOCH2^^H2OH (n+2)
OH OH HOCH2J CHf fcH2 IcH^
+ (n+l)H O
UCC 025642
+ (n+l)HCHO + {n+l)H20 'U' Wn O ;I
4
A qualitative description of the synthesis is as follows, A 22 liter reactor is charged with water, sodium hydroxide solution and crystalline t-butyl phenol. Under mechanical stirring and at approximately 50C, Formalin is charged rapidly. Continued agitation and temperature control at approxi mately 65 C is maintained for two hours. The reaction medium is diluted with water and cooled to less than 40C whence a quantity of dilute sulfuric acid is added slowly to a pH of from 4 to 5, The acidified medium is stirred for one half hour and let stand for an additional half hour. Two phases separate during this time and the product is discharged through the bottom of the reactor.
FORMULATION^ '
Reagent_____________
Water
Sodium Hydroxide (25% wt. NaOH) t36-E]
t-butyl phenol fZZW-2514]
'
Formalin (40% wt. ECHO) [3181] Water
Sulfuric Acid (30% wt. H2SO4)
Yield DMBP Syrup
Parts
142 106 100 100
71 106
149
Pounds
6.6 5.0 4.75 4.75 3.3 5.0
7. 1
Moles
14.3 ` 14.3
28.7
--
- 13.7
UCC 025643
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5.
Quality Control
Some care must be taken during the neutralization step as too rapid addition of acid results in a high local acid concentration which may cause resinification and subsequent globular precipitation. This occurrence however is not likely with diluted acid. Moderate temperature overshoot is not a critical factor in the usefulness of the resultant product. Extensive studies with higher molecular weight oligomers and lower molecular weight precursors to DMBP show that concentration levels under --30% of these species do not significantly alter the material's potency as a superior interfacial coupling agent.
A simplified titration technique for product quality control is presently under investigation by F. G. Willeboordse of our Analytical Group. As an example, an appropriate method for the determination of primary alcohol with which free formaldehyde or phenolic OH does not interfere involves removing an aliquot, adding excess pyromelletic dianhydride and back titrating with caustic to a phenolphthalein visual end point. This test will be perfected as warranted.
The shelf life or thermal stability of this heat reactive phenolic monomer toward advancement does not appear to be a problem provided the pH during the neutralization step does not go below --3.5 units by theHydrion paper test. The advancement to 2,2' dimethylene bis(4-t-butyl phenol)ethers which occurs to approximately 10% in pH 4 neutralised syrups that stand at 30 C (86 F) for 2 months^), does not alter the product's effectiveness in end use.
Manufacturing Process and Potential Use
The production of DMBP syrup in the light of the relative simplicity of its synthesis is open to a number of manufacturing options. Not the least important of these options involves the location of the production site. This choice must be considered in terms of the location of the raw materials, the existence of necessary production skills and equipment as well as end use at the King City mines in California. As the reaction scheme is sufficiently simple, production of the DMBP syrup directly at the King City plant should be feasible. It is possible, however, owing to a lack of available equipment at King City, that at least the initial production of the syrup for further evaluation should be run at the UCC Chemicals and Plastics plant in Elk Grove, California. The various process economics involved in these options will, of course, be critical factors in the final recommendations.
UCC 025644
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6
To date, DMBP pretreated chrysotile asbestos has been evaluated as a reinforcing filler in polyolefin and polyvinyl chloride resins. Evaluations of this material will be extended to other thermoplastic resins as well as to polyester (thermoset) resins; the latter of which represents a significantly larger potential market. These studies will help define the potential net volume requirements for this product.
ACKNOWLEDGMENTS
I wish to thank A. C. Soldatos for enlightening discussions and access to his prior art. Also, I wish to thank R. G. Azrak for his counsel and R. G. Wolf for his excellent technical assistance.
MDB:bcc
Notebook Reference: 10168
Date Received: May 7; 1973
Date Typed:
May 11, T973
M. D. Bertolucci
UCC 025645
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7
REFERENCES
(1) Azrak, R. G., "Phenolic Interfacial Agents for Asbestos Reinforced Thermoplastics", Overview Report, File No. 3365, August 1, 1972.
(2) Azrak, R. G., "Organic Coupling Agents (II), Mechanisms of Phenolic Agents in Asbestos Composites", File No. 3427, October 11, 1972.
(3) Soldatos, A. C., "Preparation and Potential Uses of DMBP, RP-13I, September 23, 1959.
(4) Mathew, L. D. , Notebook Reference to Pilot Plant Run 9658-48, August 5, 1972.
(5) Kopf, P. w. and Bertolucci, M. D., Analysis of DMBP Syrup by Nuclear
Magnetic Resonance Spectroscopy, January 12, 1973 and March 12, 1973.
(6) Bertolucci, M. D., Formulation; notebook reference 10168-41, 44, January 12, 1973.
UCC 025646
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