Polyurethanes containing amino organosilane modified clay

Abstract

The instant disclosure is directed to the polyurethane polymer compositions which are filled with a kaolin clay which has been modified with from 1% to 3% of an amino organosilane. The modulus and tear resistance of the polymers is improved without degradation of the remaining properties.

Description

This invention relates to polyurethane polymer compositions containing finely divided amino organosilane modified kaolin clay fillers.

The present application is a continuation-in-part of applicant's copending application Ser. No. 269,695, filed Apr. 1, 1963, now Patent No. 3,290,165, entitled, "Surface Modified Pigments," which in turn is a continuation-in-part of applicant's application Ser. No. 189,321, filed Apr. 23, 1962, entitled, "Surface Modified Pigments," now abandoned.

Polyurethane polymer compositions can be formed from a variety of polymers, l.e., thermosetting gums, thermoplastic polymers and liquid or casting polymers. The preparations for various classes and grades of polyurethanes are well known in the art and need not be detailed here; however, the general reaction by which they are formed is by a chain extension process rather than the usual polymerization reaction. In this process a relatively short chain polymer, either a polyester or a polyether, is reacted with an organic diisocyanate to form long chain urethane polymer. The process variations and polymerization variations caused thereby result in a multitude of compositions all broadly falling in one of the three classes mentioned.

The polyurethanes have several outstanding properties which make them desirable products, chief among them is abrasion resistance, good low temperature characteristics, good resistance to heat deterioration, ozone cracking, weathering, and oil or solvent swelling.

Thermosetting gum vulcanizates have a variety of uses in conveyor belts, roll covers, sandblast-hose tubes and other applications where good abrasion resistance is needed.

Thermoplastic resins can be processed on standard extrusion, injection molding, and transfer molding equipment. These resins are useful in small parts such as mallet heads, sprocket gears, adhesive coatings and unsupported sheetings such as fuel tanks, tarpaulins and chute liners.

Liquid polyurethane valcanizates exhibit good abrasion resistance, non-marking and a wide range of hardnesses. These products have use in large rolls for the steel industry, fork lift truck wheels, ladies toplifts, ball-joint seals, automotive seals, potting compounds, conveyor belts, V-belts, and tank linings.

Despite the fact that the polyurethanes have outstanding properties and are suitable for a large variety of uses, industry is constantly attempting to improve them by various means. Properties which are desirable to improve are modulus, tear resistance, hardness and abrasion resistance. In many cases reinforcing fillers have been tried but on the whole, while some improvements resulted, the degradation of other properties resulted and a completely satisfactory filler has not been found.

It is an object of this invention to provide solid polyprethane vulcanizates and thermoplastic resin compositions containing reinforcing fillers of modified kaolin clays.

Other objects and advantages will be apparent from the following specification.

I have discovered that kaolin clay modified with saturated amino organosilanes are reinforcing fillers for polyurethane polymers and impart improved properties to them. Particularly, modulus and tear resistance are improved with little, if any, degradation of other important properties.

The kaoline clays which are suitable as substrates for the modifier are refined clays of the rubber and paper grades.

The modified kaolin clays can be prepared by dissolving the desired amount of amino organosilane in a suitable solvent, adding the pigment and heating until the reaction is complete. The amount of modifier added depends upon the specific modifier used and the intended polymer to be reinforced. Generally from 1% to 3% by weight of the modifier is sufficient for most purposes.

A particularly useful process for modifying the kaolin clay involves spray drying kaolin slurries having one or more of the amino organosilanes dispersed therein. The spray drying process effects a uniform distribution of the modifier on the kaolin. Another satisfactory method of modifying the kaolin involves dissolving the desired amount of amino organosilane in a suitable solvent, adding the kaolin and heating until the reaction is complete.

The compounds used to modify the kaolin clays can be depicted by the formula: ##STR1## wherein R.sub.1 is hydrogen, alkyl, aryl, cycloalkyl, or alkylaryl; R.sub.2 is hydrogen, alkyl, aryl, cycloalkyl, or alkylaryl; R.sub.3 is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; R.sub.4 is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; R.sub.5 is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; and X is alkylene, alkylene containing secondary amino nitrogen, alkylene containing tertiary amino nitrogen, arylene, arylene containing secondary amino nitrogen, arylene containing tertiary amino nitrogen, alkylarylene, alkylarylene containing secondary amino nitrogen, alkylarylene containing tertiary amino nitrogen, arylalkylene, arylalkylene containing secondary amino nitrogen, arylalkylene containing tertiary amino nitrogen, cycloalkylene, cycloalkylene containing secondary amino nitrogen and cycloalkylene containing tertiary amino nitrogen. Some of these amino organosilanes are disclosed along with methods for their preparation in U.S. Patents Nos. 2,832,754, 2,930,809, 3,007,957, and 3,020,302. Commercially available amino organo silanes useful in the practice of this invention include "A-1100," a gamma-aminopropyltriethoxy silane (GAPTS), and "Y-2967," an amino organosilane which is a modified gamma-aminopropyltriethoxy silane, sold by Union Carbide Corporation, New York, N.Y., "Z-6020," a diamino functional silane, sold by Dow Corning Corporation, Midland, Michigan.

Representative commercially available polyurethane polymers suitable for use in this invention are "Vibrathane 5003," a thermosetting gum which is cross-linked, produced by Naugatuck Chemical Division of U.S. Rubber Company; "Elastothane 455," a thermosetting gum which is cross-linked, produced by Thiokol; "Genthane S," a cross-linked thermosetting gum produced by General Chemical; "Estane," a thermoplastic resin produced by B. F. Goodrich Chemical; "Texin," a thermoplastic resin produced by Mobay; "Multrathane," a liquid polymer produced by Mobay; "Cyanoprene 4590," a liquid polymer produced by American Cyanamid; "Adiprene L," produced by Du Pont; "Vibrathane 6000," produced by Naugatuck; and "Neothane," produced by Goodyear.

In the following formulations the gums were mill-mixed or Banbury-mixed and the thermoplastic resins were mill-mixed and injection molded.

The following formulations illustrate this invention.

Example I

______________________________________ Parts ______________________________________ Vibrathane 5003 100 Stearic acid 0.25 Dicup 40C (polymerizing agent) 5 Filler (modified clay) 60 ______________________________________

The compounds were mixed on a 6 inch by 12 inch laboratory mill and cured for 30 minutes at 307.degree. F., except for the NBS abrasion test where the cure was for 60 minutes at 307.degree. F.

The data tabulated in Table I indicates the results when 1%, 2% and 3% by weight of GAPTS modified kaolin clay and 1% by weight Silicone Z-6020 modified kaolin clay is the filler.

TABLE I __________________________________________________________________________ 1% 2% 3% 1% GAPTS GAPTS GAPTS Z-6020 Control Kaolin on Kaolin on Kaolin on Kaolin on Kaolin __________________________________________________________________________ Parts Filler/100 parts Polymer None 60 60 60 60 60 Tensile, p.s.i. 3,500 (.sup.1) 3,920 3,600 3,840 3,270 Stress 300%, p.s.i. 1,040 (.sup.1) 2,600 3,390 -- 2,520 Elongation, percent 440 (.sup.1) 470 350 265 365 Shore A Hardness 58 -- 74 74 74 73 NBS Abrasion, percent of Standard 100 -- 89 134 157 193 Minutes Cured at 305.degree. F. 30 30 30 30 30 60 __________________________________________________________________________ .sup.1 No cure.

Example II

______________________________________ Parts ______________________________________ Texin 480A 100 Modified clay 20 ______________________________________

The resin was molded at 390.degree.-410.degree. F. and post cured at 110.degree. C. for 24 hrs. The results are tabulated in Table II.

TABLE II ______________________________________ 1% Con- Kao- GAPTS trol lin on Kaolin ______________________________________ Parts Filler/100 parts Polymer None 20 20 Stress 300%, p.s.i. 1,720 2,170 2,430 Tensile, p.s.i. 5,700 2,540 2,620 Elongation, percent 640 510 400 Shore A Hardness 75 78 78 NBS Abrasion, percent of Standard 100 77 92.5 ______________________________________

Example III

______________________________________ Parts ______________________________________ Texin 480A 100 Modified clay 20 ______________________________________

The resin was molded at 390.degree.-410.degree. F. and was not post cured. The results are shown in Table III.

TABLE III ______________________________________ 0.25% 0.5% 1% GAPTS GAPTS GAPTS Con- Kao- on on on trol lin Kaolin Kaolin Kaolin ______________________________________ Parts Filler/100 0 20 20 20 20 parts Polymer Stress 300%, p.s.i. 1,090 1,680 1,725 1,735 1,720 Tensile, p.s.i. 4,380 4,470 3,340 4,250 4,400 Elongation, 610 640 560 655 595 percent Shore A Hardness 85 88 88 88 88 ______________________________________

Example IV

______________________________________ Parts ______________________________________ Estane 5701 100 Barium stearate 3 Modified clay 25 or 50 ______________________________________

The resin was molded 5' at 350.degree. F. held in the mold under pressure until the temperature dropped below 200.degree. F. The results are tabulated in Table IV.

TABLE IV ______________________________________ Con- Kaolin plus trol Kaolin 1% Z 6020 ______________________________________ Parts Filler/100 parts Polymer 0 25 50 25 50 300% Modulus, p.s.i. 1,220 1,580 1,640 2,840 3,300 ASTM Test "Die" C, lbs./in 410 500 300 560 580 NBS Abrasion Index, percent 492 521 720 1,285 16.72 NBS Abrasion Shore A 82 90 92 90 92 ______________________________________

Example V

______________________________________ Parts ______________________________________ Estane 5701 100 Barium stearate 3 Filler 25, 50 or 100 ______________________________________

The polymer batch was treated as in Example IV. The results are shown in Table V.

TABLE V __________________________________________________________________________ Kaolin Kaolin Kaolin Kaolin Kaolin Kaolin Kaolin Kaolin Con- Kao- plus 2% plus 2% plus 3% plus 1% Kao- plus 2% plus 1% Kao- plus plus 1% trol lin GAPTS GAPTS GAPTS Z 6020 lin GAPTS Z 6020 lin GAPTS Z __________________________________________________________________________ 6020 Parts Filler/100 parts 0 25 25 25 25 25 50 50 50 100 100 100 Polymer 200% Modulus, p.s.i. 860 -- -- -- -- -- 1,700 3,500 3,740 -- -- -- 300% Modulus, p.s.i. 1,440 1,780 2,940 3,260 3,040 3,000 -- -- -- -- -- -- Shore A Hardness 88 93 91 92 91 91 94 94 95 97 97 97 NBS Abrasion, Index 460 641 827 703 641 746 624 936 568 334 553 575 __________________________________________________________________________

Example VI

______________________________________ Parts ______________________________________ Estane 5701 100 Barium Stearate 3 Pigment 25 or 50 ______________________________________

The recipe was treated the same as in Example IV. The results are shown in Table VI.

TABLE VI ______________________________________ Kaolin Kaolin plus plus Con- Kao- 2% 1% trol lin GAPTS Z-6020 ______________________________________ Parts Filler/100 None 25 50 25 50 25 50 parts Polymer 300% Modulus, 1,220 1,580 1,640 2,880 3,600 2,840 3,300 p.s.i. ASTM Tear "Die 410 500 500 550 480 560 580 C," lbs./in NBS Abrasion, 492 521 720 1,015 1,411 1,285 1,672 Index percent NBS Abrasion, 82 90 92 90 91 90 92 Shore A Hardness ______________________________________

Example VII

______________________________________ Parts ______________________________________ Estane 5701 100 Barium Stearate 3 Filler 10, 20, 60 or 100 ______________________________________

The recipe was treated as in Example IV. The results are shown in Table VII.

TABLE VII __________________________________________________________________________ Con- Kaolin Plus Kao- Kaolin Plus Kao- -trol 1% Z-6020 lin 1% Z-6020 lin __________________________________________________________________________ Parts Filler/100 parts Polymer 0 10 20 20 60 100 100 300% Modulus, p.s.i. 1,280 2,040 2,740 1,640 3,420 -- 2,040 ASTM Tear "Die C," lbs./in 420 500 600 530 540 406 510 NBS Abrasion, Index percent 570 867 1,095 957 1,722 1,465 717 NBS Abrasion, Shore A 84 85 89 89 94 95 95 __________________________________________________________________________

Example VIII

______________________________________ Parts ______________________________________ Adiprene L-100 100 Methylene-bis-orthochloraniline 11 Pigment 20 ______________________________________

The mixture was cured for 180 minutes at 212.degree. F. The results are shown in Table VIII.

TABLE VIII ______________________________________ Kaolin Plus 1% Control Kaolin Z-6020 ______________________________________ Parts Filler/100 parts Polymer 0 20 20 300% Modulus, p.s.i. 1,530 -- 1,940 Tensile, p.s.i. 2,570 1,310 2,710 -Elongation, Percent 495 285 480 5 Shore A Hardness 87 88 90 ASTM Tear "Die C," lbs./in 450 408 505 NBS Abrasion, Index Percent 224 126 194 ______________________________________

The examples and data indicate that when the modified kaolin clays useful in this invention are used as fillers in thermosetting gum polyurethanes increases in modulus, hardness and abrasion resistance occur. The remaining properties of the polymer remain within acceptable levels. When these fillers are used to reinforce thermoplastic resins, increases in modulus, tear resistance, and abrasion resistance occur while the remaining polymer properties remain within acceptable levels. When these modified kaolin clay fillers are used to reinforce liquid polymers, increases in modulus, tensile strength, hardness, and tear resistance occur while the remaining properties of the polyurethane remain within acceptable levels. In all the polymers tested the general level of performance of the modified kaolins was superior to the unmodified kaolins.

The foregoing is illustrative only and additional modifications may be made without departing from the substance of the invention as defined in the appended claims.

Claims

I claim:

1. A polyurethane polymer composition containing as a filler, modified kaolin clay, said kaolin clay .Iadd.having been .Iaddend.modified .Iadd.by treatment .Iaddend.with from 1% to 3% by weight with an aminoorganosilane of the formula ##STR2## wherein R.sub.1 is selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and alkaryl, R.sub.2 is selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and alkylaryl, R.sub.3 is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, R.sub.4 is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, R.sub.5 is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, and X is selected from the group consisting of alkylene, arylene, alkylarylene, arylalkylene, cycloalkylene, cycloalkylene containing secondary amino nitrogen and cycloalkylene containing tertiary amino nitrogen.Iadd., the modification of said kaolin clay being carried out by spray drying kaolin slurries having one or more of said amonoorganosilanes dispersed therein, said spray drying effecting a uniform distribution of said aminoorganosilane on the kaolin. .Iaddend.

2. The composition of claim 1 wherein the filler is kaolin clay modified with from 1% to 3% by weight of a diamino functional silane.

3. The composition of claim 1 wherein the filler is kaolin clay modified with 1% to 3% by weight of gamma-aminopropyltriethoxysilane. .Iadd. 4. A polyurethane polymer composition containing as a filler, modified kaolin clay, said kaolin clay having been modified by treatment with from 1% to 3% by weight of an aminoorganosilane of the formula:

wherein R is selected from the group consisting of phenylene, lower alkyl substituted phenylene, lower alkoxy substituted phenylene, and lower alkylene, R' is a monovalent hydrocarbon group free of aliphatic unsaturation selected from the group consisting of lower alkyl, aryl, lower alkaryl and lower aralkyl, and wherein R' can represent the same or different groups. .Iaddend.