GB2042563A - Compositions for bonding glass fibres to rubber - Google Patents

Abstract

An aqueous alkaline dispersion for bonding glass fiber reinforcing elements or cords to rubber comprises (a) a rubbery vinyl pyridine copolymer, (b) a rubbery polybutadiene or a rubbery copolymer of at least 80% butadiene and the balance a mono-ethylenically unsaturated monomer, and (c) a water soluble, thermosetting phenolic-aldehyde resin, the gel content of (a) being 0 to 60% and that of (b) 0 to 70%, the ratio of (a) to (b) being 20:80 to 60:40 parts and the amount of (c) being 3 to 15 parts per 100 parts of (a) and (b). The compositions may also contain 2 to 10 parts of wax per 100 parts of (a) and (b).

Description

SPECIFICATION Adhesion of glass fibers to rubber The invention telates to the adhesion of glass fibers to rubber, in particular to glass fiber element containing an adhesive composition, to such an element embedded in rubber, to adhesive composition itself and to the method of its use.

The invention is especially directed to the bonding of a glass fiber reinforcing element to a rubber compound, e.g. glass fiber tire cords adhesively bonded to provide carcass plies and belt plies for making tires. Glass fiber reinforcing elements, e.g. such as those used in the belt and the carcass plies of tires, are provided with a minor amount of an adhesive so that they may subsequently be bonded to rubber on curing. A method is provided for bonding glass fibers, particularly glass fiber textiles, fibers, cords, yarns and so forth, to rubber compounds using a single dip.

U.S. Patent No. 3,300,426 discloses an adhesive dip (5-30% solids) comprising a polybutadiene rubber latex in which the rubber has 94% cis-1 4 configuration, the remaining 6% being trans-1,4, and a phenol or resorcinol-formaldehyde resin where the ratio of resin to rubber latex is from 1:10 to 2.5:10. At least one third of the latex is the PBD latex and the rest may be a rubbery vinyl pyridine latex plus other latex. The aldehyde is used in an amount of .5 to 1.5 mol per mol of the phenol. Tables I to Ill of column 4 of the patent indicate that adhesives containing another PBD latex or a SBR latex were not equivalent to those containing the cis-1,4 PBD latex. The adhesive in an amount of 1 8% by weight may be used to adhere rayon, polyester or polyamide cord or fibers to rubber on vulcanization.

U.S. Patent No. 3,567,671 discloses an aqueous dip for impregnating glass fibres comprising a resorcinol-formaledhyde resin, a butadienestyrene-vinyl pyridine terpolymer, a carboxylated butadiene-styrene latex and a microcrystalline paraffin wax.

U.S. Patent No. 3,787,224 discloses an aqueous dip for impregnating glass fibres comprising a resorcinol-formaldehyde resin, a butadienestyrene-vinyl pyridine terpolymer, a dicarboxylated styrene-butadiene resin in which the ratio of styrene to butadiene is 50/50 to 85/15 (high styrene, more resinousthan rubber) and a microcrystalline wax. It is stated that the carboxylated SBR resin latex of 3,567,671, above, was a monocarboxylated SBR.

U.S. Patent No. 3,844,821 discloses a cord dip comprising a vinyl pyridine-butadiene-styrene terpolymer latex, a R-F resin, a vinyl chloride-vinylidene chloride copolymer, an incompatible microcrystalline wax and an acrylonitrile-butadiene-styrene resin latex in which the BD accounts for only 5-25 pbw per 100 parts by weight of the BD-STY-VCN terpolymer (thus, a resin). Another dip is shown in which the vinyl chloride-vinylidene chloride copolymer has been replaced with a dicarboxylated butadienestyrene resin latex.

U.S. Patent No. 4,060,658 discloses a tire cord impregnant suitable for coating glass cords comprising a vinyl pyridine latex, a polybutadiene latex, a wax emulsion and a R-F resin. The wax emulsion contains preferably about 75 wt. % of paraffin wax and 25 wt. % of microcrystalline wax. Part of the polybutadiene latex can be replaced with a SBR latex (up to 50 wt. % in dried impregnant) formed of a STY-BD copolymer of 25 pbw STY and 35 pbw BD, e.g., a high styrene butadiene copolymer, Also, part of the polybutadiene latex can be replaced with a VCN-BD latex (up to 50 wt. % in the dried impregnant) of 65 pbw VCN and 35 pbw BD, e.g., a resin.

One of the claims specifies glass fibers containing the residue of about 10-60 wt. % of the vinyl pyridine terpolymer, 30-80 wt. % of the polybutadiene, wax in an amount of 4-6 wt. % and R-F resin in an amount of 3-4 wt. %.

British Patent No. 1,256,705 discloses a cord dip for rayon or nylon cord comprising a vinyl pyridine terpolymer latex, a butadiene-styrene-itaconic acid terpolymer latex and a R-F resin (or separately added resorcinol and formaldehyde) in a molar ratio of phenolic to aldehyde of 1:1 to 1 :3. The ratio of the VP latex to the carboxylated latex varied 80-0 to 20-100 (the VP latex had 41% solids while the carboxylated latex had 53% solids). A comparison was made in which the carboxylated latex was replaced with a SBR latex.

According to the present invention it has been discovered that a composition comprising an aqueous alkaline dispersion of a rubbery vinyl pyridine copolymer, a rubbery polybutadiene or a rubber copolymer of at least about 80% butadiene, and a heat reactable water soluble phenolic-aldehyde resin, in certain amounts and wherein the rubbery polymers have a reduced amount of gel, is very useful as a treating, dipping or coating material for use in bonding glass fiber reinforcing elements to rubber compounds. Sufficient alkaline material such as aqueous KOH or NaOH may be added to the dispersion (or to one or more of the ingredients of the dispersion before mixing them together)"to obtain the desired pH, prevent coagulation of the latex and to provide for stabilization. This will vary with the pH of the resin and the latex, all of which may vary from batch to batch.Since the amount of each compound may vary, the amount of alkaline material required can also vary. After drying the adhesive on the glass fiber reinforcing element to remove water and to heat cure or heat set the adhesive on the element, the adhesive containing element can then be combined or calendered with a curable rubber compound and the resulting assembly cured, usually in a mold, to provide a laminate exhibiting good adhesive properties.

The use of the low gel rubbery vinyl pyridine copolymer reduces the breakage which may be experienced in glass cords such as in belts in tires subjected to cold or low temperatures. The use of the low gel polybutadiene rubber or the low gel rubbery butadiene copolymer improves processing and in particular reduces flake or rub off during processing, handling and drying of the adhesive dipped cord. Such rub-off or flaking reduces the amount of adhesive left on the cord. Also, the rub-off or flake appears as fine particles in the atmosphere which causes a dusting problem and may present a fire hazard in the drying ovens due to its fine particle size and organic nature.

The present method can involve only one dipping step, and the process or method can be varied to provide the desired pick-up or solids on the cord by varying the concentration of the dip or the speed of the cord through the dip to give the amount needed to develop the requisite adhesive bond. Thus, while the cord can be run through successive dips of the same or varying amounts of the above materials to get the desired buildup, this may be unnecessary as satisfactory results generally can be accomplished in one dip.

The glass fiber reinforcing element or cord may comprise a plurality of substantially continuous and parallel glass fibers or monofilaments. The reinforcing element or fibers may contain little or no twist. In other words, twist is not intentionally applied to the element or fibers; the only twist, if any, in the element or fibers is that occasioned on passing through the glass fiber processing apparatus and on packaging or winding up the cord to form a bobbin or spool.

However, in a continuous process, the elements can proceed directly from the glass processing apparatus, can be dipped in the aqueous adhesive cord dip, dried, and given a twist of about 1.5 turns per inch thereafter. The elements then may be woven into tire fabric having about one quite small pick thread or element, nylon or polyester, which may be a monofilament, per inch and calendered with a rubber ply or skim stock. The glass fiber reinforced ply stock is then ready to be used in the manufacture of a tire or for other purposes.

Glass compositions useful in making the fibers for the reinforcing element or glass tire cord are well known to the art. One type of glass that may be used is a glass known as E glass and described in "Mechanics of Pneumatic Tires," Clark, National Bureau of Standards Monograph 122, U.S. Dept. of Commerce, issued November, 1971, pages 241-243, 290, and 291. Other glasses which may be used are G, H and K glasses. The number of glass filaments or fibers employed in the glass fiber reinforcing element or cord can vary considerably depending on the ultimate use or service requirements. Likewise, the number of strands of glass fibers, used to make a glass fiber reinforcing element or cord can vary widely.In general, the number of filaments in the glass fiber reinforcing element or cord for a passenger car tire can vary from about 500 to 3,000 and the number of strands in the reinforcing element can varyfrom 1 to 10, preferablythe number of strands is from 1 to 7 and the total number of filaments about 2,000. A representative industry tire cord known as G-75 (or G-75, 5/0) has 5 strands each with 408 glass filaments. Another representative cord known as G-15 has a single strand containing 2040 glass filaments. In this connection reference is made to Wolf, "RubberJournal," February, 1971, pages 26 and 27 and U.S. Patent No. 3,433,689.

Shortly after the glass fibers are formed they are usually sized (by spraying or dipping and so forth and air drying) with a very small amount or fractional amount by weight of a material which acts as a protective coating during processing and handling of the glass fibers in forming the strands or reinforcing elements and during packaging. During the subsequent dipping in the aqueous adhesive tire cord dip, it is believed that the size is not removed. Materials for use as sizes for glass fibers are well known to the art. It is preferred to use a silane as a size, especially a silane which has groups which can bond or coordinate chemically or physically with at least parts of the surface of the glass of the glass fiber and with at least one or more of the components of the glass fiber aqueous adhesive cord dip.A very useful size to employ on the glass fibers is gamma-aminopropyl triethoxy silane, or similar aminoalkyl alkoxyr silanes, which, when applied to the glass fibers, hydrolyzes and polymerizes to form a poly(aminosiloxane) in which a portion of the polymer is attached to the glass and another portion contains amine groups (having active hydrogen atoms) for reaction with components of the cord dip such as the phenolic resin, the polybutadiene compound or the vinyl pyridine copolymer compound. Chrome complexes having functional groups, also, can be used. Glass fiber sizing compounds are known, and some compositions are shown in U.S. Patent Nos. 3,252,278; 3,287,204 and 3,538,974.

The water soluble thermosetting (heat reactable) phenolic-aldehyde resin is made by reacting an aldehyde with a phenolic compound. Suitably, a molar excess (over stoichiometry) of the aldehyde is reacted with the phenolic compound. The preferred aldehyde to use is formaldehyde, but acetaldehyde and furfural, also, may be used. In place of formaldehyde one may use paraform, the dry powder form of formaldehyde. Also it is preferred to start with formalin, usually a 37% solution of formaldehyde in water, which is easierto use. Mixtures of aldehydes can be used. The phenolic compound can be phenol itself, resorcinol the cresols, the xylenols, p-tert, butylphenol or p-phenyl phenol or mixture thereof.

Preferably, the reactants are formaldehyde and resorcinol which are reacted in water usually in the presence of an alkaline catalyst or an alkaline material is added before use. Information on the preparation of the water soluble thermosetting phenolicaldehyde resins will be found in "Encyclopedia of Chemical Technology," Kirk-Othmer, Volume 15, Second Edition, 1968, Interscience Publishers Division of John Wiley & Sons, Inc., New York, pages 176 to 208; "Technology of Adhesives," Delmonte, Reinhold Publishing Corp., New York, N.Y., 1947, pages 22 to 52; "Formaldehyde," Walker, A. C. S.

Monograph Series, Reinhold Publishing Corp., New York, N.Y., Third Edition, 1964, pages 304 to 344 and "The Chemistry of Phenolic Resins," Martin, John Wiley & ons, Inc., New York, 1956.

Rubbery aqueous alkaline vinyl pyridine copolymer lattices are well known. See U.S. Patents Nos. 2,561,215; 2,615,826 and 3,437,122. They comprise a copolymer of about 50 to 95% by weight of butadiene-1,3, 5 to 40% by weight of a vinyl pyridine, and 0 to 40% by weight of a vinyl aromatic compound like styrene. Examples of suitable vinyl pyridines are 2-vinyl pyridine, 4-vinyl pyridine, 2-methyl-5-vinyl pyridine and 5-ethyl-2-vinyl pyridine. It is usually preferred to use a latex of a terpolymer of about 60 to 80% by weight of butadiene-1 ,3 about 7 to 32% by weight of styrene and from about 4 to 22% by weight of 2-vinyl pyridine. Even more preferred is a terpolymer of about 70% by weight of butadiene-1,3, 15% styrene and 15% 2-vinyl pyridine.The rubbery vinyl pyridine copolymer should have little or no gel, and the maximum amount of gel of the rubbery vinyl pyridine copolymer should be about 60%, e.g., a gel content of from about 0 to 60%.

Rubbery aqueous alkaline polybutadiene latices are well known. These latices can be used as such.

Or, latices can be used wherein the butadiene-1 ,3 has been copolymerized with one or more copolymerizable monoethylenically unsaturated monomers, other than a vinyl-pyridine monomer, having not over 14 carbon atoms such as a nitrile like acrylonitrile, methacrylonitrile; an amide like acrlyamide, methacrylamide and ethacrylamide; an acrylate like methyl acrylate, ethyl acrylate, butyl acrylate, ethyl hexyl acrylate and octylacrylate; an alkacrylate like methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl ethacrylate, ethyl ethacrylate, butyl ethacrylate, hydroxyethyl methacrylate and octyl ethacrylate; an acid like acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, maleic anhydride, itaconic acid and citraconic acid; and an aromatic like styrene, alpha methyl styrene, p-tertiary butyl styrene, methyl vinyl toluene and para vinyl toluene; and the like and mixtures thereof.

In these rubbery copolymers of butadiene-1 ,3 and the monoethylenically unsaturated monomer(s), the butadiene-1,3 is used in an amount of at least about 80% by weight and the vinyl monomer is used in an amount not in excess of about 20% by weight.

Examples of these rubbery polymers are polybutadiene-1,3, butadiene-1 ,3-styrene copolymer, butadiene-1,3-methacrylic acid copolymer, butadiene-1 ,3-methyl acrylate copolymer, butadiene-1 ,3-acrylonitrile copolymer, butadiene-1,3-styrene-acrylonitrile copolymer, butadiene-1 ,3-acrylamide copolymer and so forth and mixture thereof. The rubbery polybutadiene or butadiene copolymer should have little or no gel, and the maximum amount of gel of the rubbery polybutadiene or rubbery butadiene copolymer should be about 70%, e.g., a gel content of from about 0 to 70%.

The rubbery vinyl pyridine copolymer and the rubbery polybutadiene or rubbery butadiene copolymer may be made in water using free radical catalysts, chelating agents, modifiers, emulsifiers, surfactants, stabilizers, short stopping agents and so forth. They may be hot or cold polymerized, and polymerization may or may not be carried to about 100% conversion. If polymerizations are carried out with appropriate amounts of chain transfer agents or modifiers and conversions are stopped below 100% conversion, low or no gel polymers are possible.

Free radical aqueous emulsion polymerization is well known as shown by: (1) Whitby et al., "Synthetic Rubber," John Wiley & Sons, Inc., New York, 1954; (2) Schildknecht, "Vinyl and Related Polymers," John Wiley & Sons, Inc., New York, 1952; (3) "Encyclopedia of Polymer Science and Technology," Interscience Publishers a division of John Wiley & Sons, Inc., New York, Vol.2 (1965), Vol.3 (1965), Vol.5 (1966), Vol.7(1967) and Vol.9(1968); and (4) "Materials, Compounding Ingredients and Machinery for Rubber," Publ. by "Rubber World," Bill Communications Inc., New York, 1977.

The gel content of the rubbery vinyl pyridine copolymer of the polybutadiene or its copolymer is determined by taking a sample of the particular latex involved, coagulating the rubber and separating the rubber from the water, milling the rubber obtained, dissolving the rubber in toluene and filtering the mixture to determine the gel content. See Whitby et al supra.

A method of aqueous free radical emulsion polymerization to high conversions to obtain rubbery polymers like rubbery vinyl pyridine copolymers, rubbery polybutadienes and rubbery butadiene copolymers having little or no gel is fully disclosed in copending U.S. Patent Application Serial No.

904,643 filed May 10, 1978 and entitled "Aqueous Free Radical Emulsion Polymerization," the disclosure of which is incorporated herein and made a part hereof by reference to the same.

On a dry weight basis the weight ratio of the rubbery vinyl pyridine copolymer to the rubbery polybutadiene (or rubbery butadiene copolymer) is from about 20 to 60 parts by weight of the rubbery vinyl pyridine copolymer to from about 80 to 40 parts by weight of the rubbery polybutadiene or rubberybutadienecopolymerforatotal of 100 parts of rubber. On a dry weight basis the phenolicaldehyde resin is used in an amount of about 3 to 15, preferablyfrom Sto 10, partsbyweightper100 parts by weight total of rubbery vinyl pyridine copolymer and said rubbery polybutadiene or rubbery butadiene copolymer.

The pH of the latices and of the dip preferably should be on the alkaline side and the pH of any surfactants and stabilizers, including freeze-thaw stabilizers and other additives should be on the alkaline side or compatible or be neutral to avoid improper coagulation of the latices.

Water is desirably used in an amount sufficient to provide for the desired dispersion of the rubber or latex particles, and for the solution of the phenolic resin and any other additives, to obtain the desired viscosities, and for the proper solids content to get the necessary pickup of solids on and penetration between the fibers of the cord. The amount of water in the cord dip generally may vary so as to provide a solids content of from about 25 to 50%, preferably from about 30 to 40%, by weight. Too much water may require redipping or use of excess heatto evaporate the water on drying. Too little water may cause uneven penetration or too slow coating speeds.

In addition to the surfactants or wetting agents, and any antioxidants already in the latices, additional surfactants may be added to the dip, for example, in minor amounts up to about 10 parts by weight per 100 total parts rubber content (dry). Also antioxidants or other antidegradants may be added in minor amounts such as up to about 5 parts by weight per 100 parts by weight dry of total rubber content. A minor amount by weight of wax (natural or synthetic) based on the rubber solids in the dip may be added to the dip, for example from about 2 to 10 parts by weight of wax per 100 parts (dry) of the rubber content. An example of a useful wax is a wax emulsion, a blend of paraffin and microcrystalline waxes in water.

To apply the latex adhesive to the glass fiber cords in a reliable manner, the cords are preferably fed through the adhesive dip bath while being maintained under a small predetermined tension and into a drying oven where they are dried under a small predetermined tension (to prevent sagging without any appreciable stretching). As the cords leave the oven they enter a cooling zone where they are air cooled before the tension is released. In each case the adhesive-coated cords leaving the dip are dried in the oven at from about 200 to 600"F. (93.3 to 315.6"C.) for from about 300 to 5 seconds, preferably at from about 400 to 500"F. (204.4 to 206"C.) for from about 90 to 30 seconds.The time the cord remains in the adhesive is about a few seconds or more or at least for a period of time sufficient to allow wetting of the cord and at least substantial total impregnation of the fibers of the cord. The dipping of the cords and the drying or curing of the adhesive treated glass fiber cords may be accomplished in one or more dip tanks and in one or more ovens at different times and temperatures.

The single-cord H-pull, H-adhesion, test is employed to determine the static adhesion of the dried (heat set or cured) adhesive coated glass fiber cords to rubber. In each case the rubber test specimens are made from a vulcanizable rubber composition comprising rubber, reinforcing carbon black and the customary compounding and curing ingredients. In every case the cords to be tested are placed in parallel positions in a multiple-strand mold of the type described in the single-cord H-pull adhesion test ASTM designated D 2138-67, the mold is filled with the unvulcanized rubber composition, the cords being maintained under a tension of 50 grams each, and the rubber is cured for 20 minutes at about 305"F. (151.7"C.) to the elastic state. Each rubber test specimen is 1/4 inch thick and has a 3/8 inch cord embedment.Afterthe rubber has been cured, the hot cured rubber piece is removed from the mold, cooled and H-test specimens are cut from said piece, each specimen consisting of a single cord encased in rubber and having each end embedded in the center of a rubber tab or embedment having a length of around 1 inch or so. The specimens are then aged at least 16 hours at room temperature. The force required to separate the cord from the rubber is then determined at room temperature or 2500F. (121.1 'C.) using an INSTRON tester provided with specimen grips. The maximum force in pounds required to separate the cord from the rubber is the H-adhesion value.All the data submitted in the working example which follows are based upon identical test conditions, and all of the test specimens were prepared and tested in the same way generally in accordance with ASTM Designation: D2138-67.

Glass cords or fabric coated with the adhesive of the present invention using the one-step or single dip of this invention can have from about 10 to 40%, preferably from about 15 to 25%, by weight (dry) solids of the adhesive dip on the cord based on the weight of the cord and can be used in the manufacture of carcasses, belts, flippers and chafers of radial, bias, or belted-bias passenger tires, truck tires, motorcycle and bicycle tires, off-the-road tires and airplane tires, and, also, in making transmission belts, V-belts, conveyor belts, hose, gaskets, tarpaulins and the like.

While the adhesive containing glass fiber reinforcing element can be adhered to a vulcanizable blend of natural rubber, rubbery cis-polybutadiene and rubbery butadiene-styrene copolymer or a blend of natural and SBR by curing the same in combination together, it is apparentthatthe heat cured adhesive containing glass fiber reinforcing element can be adhered to other vulcanizable rubbery materials, by curing or vulcanizing the same in combination with the rubber, such as one or more of the foregoing rubbers as well as nitrile rubbers, chloroprene rubbers, polyisoprenes, polybutadienes, vinyl pyridine rubbers, acrylic rubbers, isoprene-acrylonitrile rubbers and the like and mixtures of the same.These rubbers can be mixed with the usual compounding ingredients including sulfur, stearic acid, zinc oxide, magnesium oxide, silica, carbon black, accelerators, antioxidants, antidegradants and other curatives, rubber compounding ingredients and the like well known to those skilled in the art for the particular rubbers being employed. Also, the adhesive dip of the present invention may also be used to adhere cords, yarns and the like of rayon, nylon or polyester to rubber compounds.

The following example will serve to illustrate the present invention with more particularity to those skilled in the art. In this example the parts are parts by weight unless otherwise indicated.

EXAMPLE Glass fiber tire cords (Owens-Corning Fiberglas Corp. sized H filament glass cords) were passed through an aqueous alkaline dip comprising a water soluble thermosetting phenolic resin, a rubbery vinyl pyridine terpolymer latex and either a rubbery polybutadiene latex or a rubbery polybutadienemethacrylic acid latex. All of these rubbers (latices) were prepared in emulsion using, per 100 parts by weight of monomer(s), 3.25 parts by weight (dry) of "Dresinate" 214 (resin potassium soap, a pale aqueous paste emulsifier from Hercules, Inc., Process Chem. Div.) except for Run 31 which used 4.2 parts of "dresinate" 214. The cords were next passed through a drying oven to dry and heat set or cure the dip on the cords. The ruboff or flaking during drying was observed. Some of the cords were tested as to tensile strength. Other cords were compounded, molded and cured with carcass stocks and tested as to their H-adhesion according to the above ASTM test. Still other cords were made into tire fabric and built as belts into passenger tires (radial type, polyester carcass, two glass belts, size HR78) and tested according to the ARA Cold Gristmill test for total breaks in glass belts.

The composition of the cord dips and method for their preparation is shown below in Table I (see Notes below for explanation of abbreviations): TABLE I A. Ingredients (Dry Weights except water): 1. VP-40 pts.

2. Bd or BMAA-60 pts.

3. RF resin-7.7 pts. (5.81 pts. resorcinol and 1.75 pts. formaldehyde).

4. #1500 wax-6 pts.

5. Additional Wetting agent-variable.

6. Antioxidant-variable.

7. Water-To take total solids to 35%.

B. Resin Make-Up (Dry Weights except water): 1. Resorcinol-5.82 pts.

Formaldehyde-1.75 pts.

Water-5.96 pts.

2. Allow to stand 4 hours @80 F. (26.7 C) 3. Add H2O-1.2 pts.

KOH-.15 dry weight, pts.

Allow to stand 4 hours @80 F (26.7 C.).

C. Description ofDip Make-up: 1. VP latex and Bd latex and H2O blended together.

2. Resin solution added to blend (after aging).

3. Then wetting agent, antioxidant and #1500 wax added in this order.

Data on the dip conditions and results obtained are shown below in Table II, below: TABLE II (PartA) Run Latex No. Latex ML4 % Gel Particle Size 1 VP 58 29.3 702A (Maj) BD 58 60.5 3100 A" (Bi 1300 & 2900) 2 VP 60 13.4 937A" (Maj) BD 53 58.5 1800A" (Broad-Maj 1800) 3 VP 58 29.3 702A (Maj) BD 38 20 1000A (Broad700 & 1300) 4 VP 113 73 799A'(Maj) BD 38 20 1000A (Broad700 & 300) 5 VP 58 29.3 702A (Maj) BD + 77.8 1000A'(Maj) 6 VP 113 73 799A (Maj) BD + 77.8 1000A (Maj) 7 VP 58 29.3 702A (Maj) BD 40 27.2 3100A" 8 VP 113 73 799A (Maj) BD 40 27.2 3100A" 9 VP 58 29.3 702A (Maj) BD 57 60.5 3100A (Bi1300 & 900) 10 VP 113 73 799A (Maj) BD 57 60.5 3100A" (Bi 1300 & 2900) 11 VP 58 29.3 702A'(Maj) BD 38 20 1000A (Broad700 & 300) 12 VP 113 73 799A" (Maj) BD 38 20 1000A (Broad700 & 300) 13 VP 58 29.3 702A (Maj) BD + 77.8 1000A (Maj) 14 VP 113 73 799A (Maj) BD + 77.8 1000A (Maj) 15 VP 58 29.3 702A (Maj) BD 40 27.2 3100A" 16 VP 113 73 799A (Maj) BD 40 27.2 3100A 17 VP 113 73 799A (Maj) BD 57 60.5 3100A (Bi1300 & 900) 18 VP 89 44.4 810A (Maj) BD 53 58.5 1800A" (Broad-Maj 1800) 19 VP 89 44.4 810A (Maj) BD 53 58.5 1800A" (Broad-Maj 1800) 20 VP 89 44.4 810A (Maj) BD 53 58.5 1800A (Broad-Maj 1800) TABLE (CON'T.) (PartA) Run Latex No. Latex ML-4 % Gel Particle Size 21 VP 50-70 Av. 65 BMAA - 15 800A 22 VP 190 92.7 620A (Maj) BD 53 58.5 1800A" (Broad-Maj 1800) 23 VP 89 44.4 810A (Maj) BD 21 9.4 1800A"(Bi-Maj800-Min1900) 24 VP 89 44.4 810A (Maj) BD + 93.6 1800A0(BroadSOO & 200) 25 VP 50-70 Av. 65 BMAA - 15 800A 26 VP 89 44.4 810A"(Maj) BD 45 41.5 1200A (Bi-800 & 1700) 27 VP 60 13.4 937A (Maj) BD + 91.3 3100A (Bi-1000 & 2800) 28 VP 89 44.4 810A (Maj) BD 53 50.5 1800A (Broad-Maj 1800) 29 VP 89 44.4 810A (Maj) BD 53 58.5 1800A (Broad-Maj 1800) 30 VP 89 44.4 810A (Maj) BD 53 58.5 1800A (Broad-Maj 1800) 31 VP 50-70 Av.65 700A BD 38 20 1000AO (Broad-700 & 300) 32 ABC - - - TABLE (CON'T.) (Part B) Wetting Agent Anti Run (Pts.) Added Oxidant Ruboff No. To Dip (Pts.) Comments Rating 1 3.0B-5 0 Tacky 2 2- .75 Wing. L Sizeable Amount of Kickout 4 3 2 KFA 1.5 Wing.L Would not Run Originally 4 2 KFA 0 Would Not Run Originally 5 ~ 0 Blistered 9 6 - 1.5 Wing. L Blistered 10 7 - 0 Blistered 7 8 - 1.5 Wing. L Blistered 8 9 1.5 1.5 Wing. L L 6 10 - 0 Gubbers Blistered 9 11 3.0 B-5 0 Tacky 2 12 3.0 B-5 1.5 Wing. L - 6 13 3.0 B-5 1.5 Wing. L - 8 14 3.0 B-5 0 Tacky 8 15 3.0 B-5 1.5 Wing. L Tacky 8 16 3.0 B-5 0 Tacky 5 17 3.0 B-5 1.5 Wing. L - 8 18 1.5 B-5 .75 Wing. L - 4 19 1.5 B-5 .75Wing.L Small Amount of Kickout 2 20 1.5 B-5 .75 Wing. L L 5 21 None Added 0 SRF 4 22 - .75 Wing. L Sheared Out Kickout 5 23 2 KFA .75 Wing.L Bad Rub Off TABLE Il (CON'T.) (Part B) Wetting Agent Anti Run (Pts.) Added Oxidant Ruboff No. To Dip (Pts.) Comments Rating 24 - .75 Wing. L Bad Ruboff; Break in Cord; Blister Adj. 10 25 None Added 0 SRF 26 - .75 Wing. L - 5 27 - .75 Wing. L Gubbers, Blistered 9 28 5.0 B-5 .75 Wing. L - 6 29 1.5 B-5 0 5 30 1.5 B-5 3.0 Wing. L Sizeable Amount of Kickout 7 31 4.2 Dres. 214 0 - 2 during pzn. + .4KFAadded to dip 32 - TABLE (CON'T.) (Part C) Run Indicates Age H Adhesion (MC-MH) No. D.P.U.MIT Flex (NC-NH) Tensile 1 18.1 4901 37.8 26.0 61.5 33.1 18.6 2 20.3 3912 40.4 27.5 51.6 33.4 24.2 3 19.6 2273 40.5 29.8 57.8 28.4 22.0 4 19.5 1863 38.0 29.5 59.3 30.6 21.2 5 19.4 4631 36.9 24.0 57.0 31.7 19.9 6 18.6 2851 36.0 22.7 61.8 30.4 21.1 7 18.5 2985 40.3 27.9 53.5 31.5 22.2 8 18.8 3611 37.9 27.0 65.3 34.3 22.0 9 19.7 319' 40.8 27.9 57.7 35.3 22.5 10 20.1 4321 39.3 27.3 54.7 33.5 21.3 11 17.8 575' 35.1 25.5 58.7 30.5 20.0 12 18.5 4641 37.6 23.0 61.3 31.3 21.1 13 19.7 6871 34.8 21.6 66.0 25.3 17.2 14 18.6 490' 34.1 22.5 62.0 24.0 16.2 15 18.2 365' 36.5 25.4 53.9 29.3 19.3 16 17.8 5081 38.3 25.7 61.3 30.4 20.2 17 19.3 5522 35.4 24.9 61.8 31.0 19.6 18 19.3 5532 38.0 28.4 63.7 26.5 18.6 TABLE (CON'T.) (Part C) Run Indicates Age H Adhesion (MC-MH) No. D.P.U.MIT Flex (NC-NH) Tensile 19 20.4 4052 37.2 26.8 64.4 31.2 19.2 20 18.6 4772 37.5 22.5 59.0 23.1 17.3 21 20.7 - 35.6 22.5 60.3 28.0 18.0 22 19.2 2793 36.4 27.9 58.8 33.2 22.0 23 18.2 350 40.3 28.3 47.5 32.2 23.3 24 20.0 1643 42.3 25.7 58.0 32.8 20.0 25 20.0 - 32.8 18.8 59.7 22.6 12.9 26 19.4 2703 38.5 28.2 57.8 33.2 22.1 27 18.0 3362 40.8 27.9 68.2 33.3 25.1 28 19.5 3323 37.2 26.0 54.8 29.6 18.3 29 19.4 3633 37.5 27.7 56.5 31.8 20.5 30 20.3 2543 38.5 25.1 53.5 33.5 20.8 31 18.8 353' 40.3 27.4 59.3 36.3 23.5 32 18.7 491' 35.8 24.7 65.4 29.0 17.5 TABLE II (CON'T) IPart D) Run ARA ARA No. Tire No. No. of Breaks Avg. Breaks 1 B-59 24 24.5 B-60 25 2 B-83 7 6.5 B-84 6 3 B-2 80 131 B-3 182 4 B-8 277 247 B-5 218 5 B-10 25 45 B-11 66 6 B-14 23 36 B-15 50 7 B-19 40 58 B-17 76 8 B-22 57 75 B-23 93 9 B-28 3 39 8-26 76 10 B-30 97 77 B-31 57 11 B-36 69 46 8-34 24 12 8-39 37 38 8-38 39 13 8-42 27 93.5 8-43 160 14 B-45 30 69.5 B-46 109 TABLE (CON'T.) (Part D) Run ARA ARA No. Tire No. No. of Breaks Avg.Breaks 15 B-49 50 91.0 B-51 132 16 B-54 44 130.0 B-56 216 17 B-63 90 112.0 B-64 134 18 B-65 87 97.5 8-66 108 19 B-69 35 79.5 8-71 124 20 B-75 82 100.0 B-76 118 21 B-79 102 231.0 B-80 360 22 B-87 84 154.0 B-88 224 23 B-91 136 100.0 8-92 64 24 B-93 14 14.0 25 8-97 115 169.5 8-98 224 26 8-103 28 32.5 8-104 37 27 B-105 23 31.5 B-107 40 28 B-109 39 37.0 B-110 35 29 B-113 45 49.5 B-114 54 30 B-115 34 57.5 B-116 81 31 B-121 138 173.5 8-122 209 32 A-6 23 25.5 A-7 28 Notes for the above Exam:: VP-Rubbery terpolymer of about parts by weight. 70/butadiene-1.3. 1 5/styrene and 1 5/2-vinyl pyridine, free radical copolymerized in aqueous alkaline emulsion.

BD-Polybutadiene, free radical polymerized in aqueous alkaline emulsion.

BMAA-Rubbery copolymer of about, parts by weight. 99/butadiene-1.3 and 1/methacrylic acid, free radical copolymerized in aqueous emulsion and then made alkaline.

ABC-Commercially available dipped glass cord: composition of dip on cord unknown.

ML4 Mooney viscosity at 212of. 1100 C) ±Too tough to measure.

--None or not determined.

Av.-Average A -Angstrom units.

Maj-Major.

Bi-Bimodal Min-Minor Broad-Broad distribution as indicated B-5-"Polystep" B-5, sodium lauryl sulfate, emulsifier, Stepan Chem. Co. This wetting agent does not apparently increase glass cord breakage but does seem to reduce H-adhesions.

KFA-Potassium fany acid soap. This wetting agent apparently increases glass cord breakage.

Wing. L-"Wingstay" L, butylated reaction product of p-cresol and dicyclopentadiene, Goodyear Chemical. This antioxidant does not appearto have any effect on glass cord breakage.

Kickout-Particles in dip due to shear caused by cord running through dip.

Blisters-Blisters showing on dip deposit on cord after drying.

Gubbers- Soft blisters.

SRF-The resin used in the dip was different from the above. It was obtained from Schenectady Chem. Co. in which excess resorcinol was used compared to formaldehyde. Then sufficient furfural and alkali was added to give molar excess of aldehyde and to provide a thermosetting type of phenolic resin.

Ruboff Rating best. 10 worst. Ruboff or flaking of dip from cord during drying.

D.P.U.-Dip pick-up. % by weight of dry dip on cord.

M.I.T.-Mass. Inst. of Technology flexing machine. Flex over 270 arc. Room temperature test.

Age-Superscript numbers indicate after dipping relative age before cord tested, ' being the shortest time.

H-adhesion-In pounds as described above.

C-Cord pulled cold (at room temperature. about25 C.).

H-Cord pulled at 250"F (121.1"C.).

Mis the rubber compound or stock used for one series of H-adhesion tests: M Componenr Parts by Weight Natural Rubber 46.50 Polybutadiene rubber, cis type, 15.00 solution polymerized, The General Tire & Rubber Co.

SBR 1778 52.90 (Blend 38.50 cold SBR) Rubber and 14.40Naphthenic Oil) Fine Extrusion Furnace Carbon 66.00 Black Tackifying resin 2.50 Naphthenic Oil 12.00 zinc Oxide 3.80 Stearic Acid 1.50 Styrenated Phenol 1.20 "Altax", benzothiazyl disulfide 1.10 R. T. Vanderbilt Co.

"Thionex," tetramethyl thiuram .10 monosulfide. du Pont "Crystex" (2.40 insoluble sulfur 3.00 and .60 petroleum oil), Stauffer Chemical N lathe rubber compound or stock used for a second series of H-adhesion tests: N Component Parts by Weight Natural Rubber 50.

Peptizer .15 Butadiene-Styrene rubber, SBR-1502 50.

High abrasion furnace carbon 35.

black ZnO 3.

Stearic Acid 1.

Processing resin 2.

Styrenated phenol 1.

Naphthenictype oil, non- 7.

staining Diphenyl guanidine .15 "Nobs" #1,9Dk N-oxydiethylene- 0.9 2-benzothiazyl-sulfenamide and 10% benzothiazyl disulfide.

American Cyanamid Co.

Sulfur 2.60 Tensile-Tensile strength in pounds at break of dipped and heat dried cord at room temperature in air.

#1500 Wax-Wax emulsion, combination of paraffin and microcrystalline waxes with anionic emulsifier. General Latex.

ARA-ARA (Automotive Research Association Cold Gristmill) test. which was conducted as follows: 1. Cool mounted tires to -40 F (-40 C.) for 3 hours at 24 psi ambient.

2. Place the tire on the right front side of the car and let the car offthe jack when the tire reaches -25 E (-31 .7 C.).

3. Run the car 10 laps in a counter clockwise direction around an 85 ft. diameter circle using 11 second laps with 1,650 pounds load on the tire (24 p.s.i. ambient). The test tire being the outside front tire from the center of the circle.

4. Recool the tire for 3 hours and repeat the cycle of 3.

5. After 6 cycles (60 laps), x-ray the tire through the rim inflated to 40 psi. Here, the tire is demounted and remounted on a special rim with plastic windows to enable examination by x-rays.

6. Read the x-rays of the entire belt and count each break.

Claims (22)

1. A glass fiber reinforcing element containing from about 10 to 40% by weight (dry) based on the weight of said element of a heat cured adhesive composition useful for adhering said element to a rubber compound and comprising.

(a) a rubbery vinyl pyridine copolymer having a gel content of from about 0 to 60%, (b) at least one rubbery polymer selected from the group consisting of polybutadiene-1,3 and copolymers of at least about 80% by weight of butadiene-1,3 and not more than about 20% by weight of at least one copolymerizable mono-ethylenically unsaturated monomer, other than a vinyl pyridine monomer, having not over 14 carbon atoms, said rubbery polymer having from about 0 to 70% gel, the ratio of (a) to (b) being from about 20:80 to 60:40 parts by weight, and (c) a water soluble thermosetting phenolic-aldehyde resin in an amount of from about 3 to 15 parts by weight per 100 parts total by weight of (a) and (b).

2. A glass fiber reinforcing element according to claim 1 wherein said rubbery vinyl pyridine copolymer of (a) is a terpolymer of from about 60 to 80% by weight of butadiene-1,3, from about 7 to 32% by weight of styrene, and from about 4 to 22% by weight of 2-vinyl pyridine, wherein said phenolic aldehyde resin of (c) is used in an amount of from about 5 to 10 parts by weight per 100 parts total by weight of (a) & (b), wherein said phenolic-aldehyde resin of (c) is a resinol-formaldehyde resin, wherein said composition contains additionally from about 2 to 10 parts by weight of wax per 100 parts by weight total of (a) & (b), and wherein said element contains from about 15 to 25% by weight of said adhesive composition.

3. A glass fiber reinforcing element according to claim 2, wherein, (a) is a rubbery terpolymer of about 70% by weight of butadiene-1,3, 15% by weight of styrene and 15% by weight of 2-vinyl pyridine.

4. A glass fiber reinforcing element according to claim 3 wherein, (b) is polybutadiene.

5. A glass fiber reinforcing element according to claim 4 where said composition contains addition ally up to about 10 parts by weight of a surfactant per 100 parts by weight total of (a) & (b).

6. A glass fiber reinforcing element according to claim 4 or claim 5 wherein said composition contains additionally up to about 5 parts by weight of an anti oxidant per 100 parts by weight total of (a) & (b).

7. A glass fiber reinforcing element according to claim 3 wherein, (b) is a copolymer of about 99 parts by weight of butadiene-1 ,3, and 1 part by weight of methacrylic acid.

8. A glass fiber reinforcing element according to claim 1 substantially as herein described in the Example.

9. A bonded composite material comprising a glass fiber reinforcing element according to any one of the preceding claims embedded in a vulcanized rubber, said composition of said element forming a bond between said element and said rubber.

10. A bonded composite material according to claim 9 substantially as herein described in the Example.

11. A composition of matter comprising an aqueous alkaline dispersion of from about 25 to 50% by weight of solids comprising (a) a rubbery vinyl pyridine copolymer having a gel content of from about 0 to 60%, (b) at least one rubbery polymer selected from the group consisting of polybutadiene-1,3, and copolymers of at least about 80% by weight of butadiene-1 ,3 and not more than about 20% by weight of at least one copolymerizable monoethylenically unsaturated monomer, other than a vinyl pyridine monomer, having not over 14 carbon atoms, said rubbery polymer having from about 0 to 70% gel, the ratio of (a) to (b) being from about 20:80 to 60:40 parts by dry weight, and (c) a water soluble thermosetting phenolic-aldehyde resin in an amount of from about 3 to 15 parts by dry weight per 100 parts total by weight dry of (a) & (b).

12. A composition of matter according to claim 15 wherein said rubbery vinyl pyridine copolymer of (a) is a terpolymer of from about 60 to 80% by weight of butadiene-1,3, from about 7 to 32% by weight of styrene, and from about 4 to 22% by weight of 2-vinyl pyridine, wherein said phenolic-aldehyde resin of (c) is used in an amount of from about 5 to 10 parts by weight dry per 100 parts total by weight dry of (a) & (b), wherein said phenolic-aldehyde resin of (c) is a resorcinol-formaldehyde resin, wherein said composition contains additionally from about 2 to 10 parts by weight dry of wax per 100 parts by weight total dry of (a) & (b), and wherein said solids content is from about 30 to 40% by weight.

13. A composition of matter according to claim 12 wherein (a) is a rubbery terpolymer of about 70% by weight of butadiene-1 3, 15% by weight of styrene and 15% by weight of 2-vinyl pyridine.

14. A composition of matter according to claim 13 wherein (b) is polybutadiene.

15. A composition of matter according to claim 14 where said composition contains additionally up to about 10 parts by weight dry of a surfactant per 100 parts by weight total dry of (a) and (b).

16. A composition of matter according to claim 14 or claim 15 wherein said composition contains additionally up to about 5 parts by weight dry of an antioxidant per 100 parts by weight total dry of (a) and (b).

17. A composition of matter according to claim 13 wherein (b) is a copolymer of about 99 parts by weight of butadiene-1 3, and 1 part by weight of methacrylic acid.

18. A composition of matter according to claim 11 substantially as any herein described in the Example.

19. A method for adhering a glass fiber reinforcing element to a rubber compound which comprises treating said element with a composition according to any one of claims 11 to 18, combining said dried and heat cured adhesive containing reinforcing element with an unvulcanized vulcanizable rubber compound, and vulcanizing the same.

20. A method according to claim 19 wherein said composition comprises an aqueous alkaline dispersion of about 30 to 40% by weight of solids, and the said treated element is heated at a temperature of from about 200 to 600"F for from about 300 to 5 seconds to remove essentially all of the water from said composition and to provide said element with a heat cured adhesive in an amountoffrom about 15to 25% by weight (dry) based on the weight of said reinforcing element.

21. A method according to claim 20 wherein said treated element is heated at a temperature of from about 400 to 500 F, for about 90 to 30 seconds.

22. A method according to claim 19 substantially as herein described in the Example.