JPH05202343A - Highly adhesive coating composition for rubber substrate, production of bubber article, and vulcanized rubber article,colored tire, and bonded article - Google Patents

Abstract

PURPOSE: To provide a high adhesion coating compsn. for a rubber substrate which has excellent air bleed, handleability, stability, weather resistance, and aging resistance and is useful for tires and the like by comprising an aq. binder mixture comprising: a rubber latex; and a resin emulsion contg. ground rubber particles.

CONSTITUTION: This high adhesion coating compsn. for a rubber substrate comprises an aq. binder mixture comprising: pref. 0.5 to 15 (wt).% rubber latex contg. 15 to 85% naturally occurring or synthesized rubber; and pref. 1 to 30% resin emulsion comprising pref. 4 to 60% ground rubber, which can provide air bleed and has a particle diameter of 20 to 200 μm, and 15 to 85% naturally occurring or synthesized lower aliph. hydrocarbon.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

This invention relates to high air bleed during cure and rubber following cure.
Especially tire sidewalls, treads, lamellas (ven
eer) and a paint having high adhesion to the carcass. It is very suitable for use as an adhesive or topcoat or finish for rubber objects, especially as an outer coating of tires applied prior to curing or vulcanization.
The highly adhesive composition of the present invention is formed.

[0002]

BACKGROUND OF THE INVENTION In general, the molding of rubber products, especially tire carcasses, requires application of the composition to the sidewalls or the entire exterior of the uncured product prior to charging it into a mold for curing. To do. While such compositions promote mold release and improve molding properties, their primary function is to act as a venting medium for the trapped air and thus the drawbacks that may be formed on the outer surface during curing. Is to reduce. For example, when air is trapped between the tire wall and the mold during curing and molding, bubble defects are cured and enter the tire. This bubble appears as a depression in the tire sidewall.

In general, when applied to rubber products prior to molding and curing, paints that provide high adhesion with adequate degassing have low pyrotechnic properties containing as little as 5-10% solids. Based on hydrocarbon solvents. Such low temperature ignitable, high volume solvent compositions release large amounts of solvent into the atmosphere during application (usually by spraying) and vulcanization.
Due to the hazardous atmosphere created during its application, OSHA is not used for such solvent-based products.
(Occupational safety and health conditions) have been challenged, raising labor issues with the handling of such low temperature pyrophoric, high volume solvent products. Such compositions also pose a fire hazard.

Further commonly used low boiling solvent coating compositions contain 5 to 10% carbon black in suspension with substantially lesser amounts of dissolved rubber. The solvent in such compositions evaporates as soon as the composition is sprayed onto the outer surface of the uncured tire,
It leaves a thin surface film of carbon black and rubber that binds tightly to the rubber after curing or vulcanization. In such solvent-based compositions, the high carbon black loadings required to improve venting often result in poor adhesion. This is particularly problematic because good adhesion is important for tire substrates having a tread-on-wall type construction. Another drawback of solvent-based compositions is that they are typically unstable on storage and must be used within a relatively short period of time after manufacture. For this reason, they are typically homemade by the user.

On the other hand, generally commercially available water-based compositions containing both carbon black and an inorganic filler together with a rubber latex binder provide sufficient venting, but they are mostly adhesive. Does not have. Water-based compositions tailored to provide sufficient adhesion do not provide sufficient air bleed properties.

[0006]

SUMMARY OF THE INVENTION In order to provide a coating material for rubber products which does not have the drawbacks of conventional coating materials, it is compatible with the rubber surface and effectively adheres to the rubber surface, while at the time of curing. Water-based compositions that have sufficient air bleed properties to allow relatively short drying times are desirable. Such coatings should eliminate defects such as wrinkles on the surface, unfilled voids, imperfections and cracks without leaving baldness or residue on the molding surface. They have sufficient storage and handling stability,
The weathering and aging resistance of the cured rubber product should not be adversely affected.

[0007]

Satisfaction between high adhesion and cure consisting of a water-based mixture of a rubber latex and a resin emulsion containing an amount of ground rubber which is effective to provide air bleed. Provided is a coating composition for rubber products having a possible air bleed. Since the compositions of the present invention provide excellent adhesion and a satisfactory air bleed during cure, they are conventional, with water charged with a sufficiently high filler to provide sufficient venting. Effectively eliminates the problem of poor adhesion in combination with the base composition.

Furthermore, the coating composition of the invention, when applied to a rubber substrate, for example a tire (which is then cured), despite the fact that the ground rubber does not individually act as a high adhesive material. Bonds with unexpected strength. However, in the combination in the paint of the present invention, the ground rubber / rubber latex / resin emulsion component, when applied to the rubber substrate prior to curing, provides good molding characteristics with effective air bleeding,
Further, there is provided a product having no unfilled voids, improper fixation, and no cracks on the surface, and at the same time having no defect of strongly adhering to a cured rubber substrate.

Since the coating composition of the present invention adheres very strongly when properly cured, it is particularly effective as an adhesive as well as a surface coating. The compositions of the present invention have a reasonably effective room temperature tack (often "building tack" as such an adhesive.
, but they are not
It acts as a useful adhesive and does not trap air in the cured bond.

An advantage of the present invention is that the water-based composition of the present invention comprises about 4 to about 60% by weight ground rubber, about 0.5 to about 15% by weight rubber latex and about 1 to about 1% resin emulsion. It is understood that it is not necessary for the rubber latex and the resin emulsion to be present in equal amounts, obtained in an advantageous manner containing 30% by weight. Generally, the composition contains from about 30 to about 85 wt% water and from about 15 to about 70 wt% solids.

Advantageously, the compositions according to the invention also contain tackifiers, wetting agents, thickeners, surfactants and fungicides / preservatives. Other suitable additives including colorants, shear stabilizers, foam control agents, sequestrants or wetting agents and fillers may be used if desired.

The present invention also includes a method of molding a rubber article which is substantially free of surface defects, the method comprising a ground rubber mixed with the outer surface of an uncured rubber article with a mixture of rubber latex and resin emulsion. Coating with an aqueous composition, and then curing or vulcanizing the coated rubber product. The rubber product is advantageously cured in the mold under suitable curing conditions.

Finally, the invention comprises a method of adhering or bonding rubber surfaces, which comprises at least one of the following:
One surface is coated with an aqueous composition containing ground rubber in admixture with a mixture of rubber latex and resin emulsion, the coated surface being combined with the surface to be adhered and heated / cured / added. It consists of sulfurization, curing and adhesive bonding. It is advantageous to dry the coated surface before it is glued.

In the following description, "parts" and "%" of the components contained in the coating composition of the present invention refer to "parts by weight" and "% by weight" with respect to the total weight of the composition unless otherwise specified. "
Is.

The coating composition of the present invention can be applied to the rubber substrate to be cured, in particular tire sidewalls, treads, slabs, carcass and the like. The substrate can be any natural or synthetic rubber or combination thereof. In general,
The base material is ethylene, an α-alkene having 3 to 8 carbon atoms, such as one or more propylene and / or 1-butene, and, if desired, a polyethylenically unsaturated compound having a non-conjugated double bond, such as 1, 4-hexadiene, dicyclopentadiene, 5-methylene-2-norbornene, 5
It may be a saturated or unsaturated polyalkylene rubber substrate consisting of one or more of ethylidene-2-norbornene and 5-isopropylidene-2-norbornene. These rubbers generally have Ziegler-Natta catalysts (Ziegler-
It is prepared as a solution or dispersion in the temperature range of -30 to + 100 ° C. using an organometallic catalyst system known as Nattacatalysts. The polyalkylene rubber is ethylene having 30 to 90% by weight and α-containing 3 to 8 carbon atoms.
It contains 10 to 70% by weight of one or more alkenes and, if desired, 0.3 to 15% by weight of one or more compounds having an ethylenically unsaturated non-conjugated C—C bond.

The rubber substrate is therefore any suitable natural rubber, synthetic polyisoprene, styrene-butadiene rubber,
Butyl rubber, bromobutyl rubber, chlorobutyl rubber, neoprene rubber, ethylene propylene rubber, nitrile elastomer, polyacrylic rubber, polysulfide polymer, silicone elastomer, poly and copolyester, high molecular weight styrene resin, ethylene acrylic elastomer, vinyl acetate ethylene copolymer, chlorinated Or it may be chlorosulfonated polyethylene and the like and mixtures thereof.

The rubber substrate is mixed with one or more oligomers or polymers of α-alkenes or any conventional additives such as oils, carbon black and / or other fillers, zinc oxide, stearic acid and the like. It may be a polyalkylene rubber.

The surface of the product to be coated can optionally be pretreated, for example with an oxidizing agent or by UV-irradiation, and the coating composition then applied in any suitable manner, for example by brushing, spraying. , Dipping, roller, etc.

The ground rubber filler of the present invention may be any suitable vulcanized or unvulcanized rubber or these which may be ground in a suitable manner under suitable low temperature conditions or suitable environmental conditions. Can be produced from a mixture of Ground rubber can be obtained by grinding hardened or uncured rubber products, such as old or substandard tires, wiper blades or any other available rubber material including the base materials. Products with a high natural rubber content are advantageous. Advantageously, the rubber has a particle size of about 50 mμ or greater, preferably about 5 to about 400.
to about 200 to about 200 .mu. It may be necessary to mill the particles several times. The amount of ground rubber filler in the coating composition of the present invention is generally in the range of about 4 to about 60% by weight, more preferably about 5 to 40% by weight.

Separators can be used to keep the rubber particles separate, especially in high humidity. Generally up to about 2% by weight of any suitable separating agent, such as finely divided filler, preferably talc, carbon black, zinc stearate, calcium carbonate and the like, can be used for this purpose.

The coating composition of the present invention has a volume ratio of ground rubber filler to binder (rubber latex and resin emulsion) of about 2.
It is advantageous to have 5: 1 to about 7.0: 1. In general, a particular filler content can be mathematically established depending on the relative air bleed requirements needed to mold a defect-free rubber product. For example, relative air bleed capability.
The ties) can be calculated as the total amount of filler in the composition divided by the total amount of binder with a high air bleed which exhibits a higher value. The actual air bleed is best shown by the success in curing rubber articles molded without defects under actual manufacturing conditions.

The binder of the coating composition comprises a rubber latex and a resin emulsion which may be mixed together or added separately at any time before the composition is completed. The rubber latex component of the binder of the present invention may be any aqueous latex containing from about 15 to about 80% by weight of natural or synthetic rubber particles, preferably from about 30 to about 70% by weight. As used herein, "rubber" refers to ASTA Standard (Standard) ASTM-D1566-6.
2T, 1964, Part 28 (Part 28), page 801. Although some synthetic rubbers may provide both binding capacity and oxidation resistance, it is generally advantageous to use all or substantially all natural rubber latex. This is because natural rubber gives better adhesion when it is disposed with the resin dispersion of the present invention.

If synthetic rubber is to be used, it should be
It should be compatible or miscible with the rubber of the substrate to be coated and should be disposable in a free flowing liquid coating composition that does not readily settle. Suitable synthetic materials include, for example, neoprene (polychloroprene), styrene-butadiene rubber (SBR), acrylonitrile-
Included are butadiene rubber (NBR), high molecular weight olefin polymers with or without other monomers or polymers, such as butyl rubber and cis and trans polybutadiene. Other synthetic materials include Kirk-Othmer, Encyclopedeer of Chemical Technology, 1966 (Kirk-Othmer, Encycl.
opedia of Chemical Techno
, Vol. 7, pp. 676-716,
It is more fully described. Other natural rubber is Kirk-
Otomer, Encyclopedia of Chemical Technology, 1966 (Kirk-Othmer, Enc
yclopedia of Chemical Tech
No., 1966), Volume 17, pages 660-682.

The rubber latex used according to the invention should contain 15 to 85% by weight, preferably 30 to 70% by weight, of natural or synthetic rubber or combinations thereof. The amount of rubber provided by the rubber latex component of the coating composition of the present invention is generally from about 0.3 to about 8% by weight, preferably 1
Should range from ˜5% by weight. The amount of rubber latex in the coating composition of the present invention is in the range of about 0.5-15% by weight.

Preference is given to latices of 1,3-butadiene, 2-methyl homopolymer, styrene butadiene, polyisoprene or any other suitable natural or synthetic rubber or mixtures thereof. Natural rubber latex is preferred.

Advantageous commercially available rubber latices include Firestone Synthetic Rubber and Latex Co. , Akron, Ohio (Firestone)
Synthetic Rubber & Latex
Co. , Akron, Ohio of Hartex
tex) 103, Polizer latex, Shatanoga,
Tennessee (Polysar Latex, Chatta)
Noiza, Tennessee's Polizer (Pol)
ysar) PL-403, Goodyear Tire and Rubber Company, Akron, Ohio
dye Tire & Rubber Compa
ny, Akron, Ohio's Pliolite (Pli)
Olite) 5356 and GNL-150 latex and the like and mixtures thereof.

The resin emulsion used in the present invention comprises, for example, about 15 to 85% by weight, preferably about 30 to 70% by weight of a natural or synthetic lower aliphatic hydrocarbon or a combination thereof having 2 to 20 carbon atoms. It should contain wt%.

The amount of rubber solids contributed by the resin emulsion of the coating composition of the present invention is generally in the range of about 0.3 to about 15% by weight, preferably 1 to 8% by weight. The amount of resin emulsion in the coating composition of the present invention is in the range of about 1-30% by weight.

The resin emulsion component of the binder of the present invention is advantageously a dispersion of paraffin oil or an aliphatic petroleum resin. Solids content of low molecular weight aliphatic hydrocarbon resins derived primarily from dienes and other reactive olefin monomers of about 5
Having a viscosity of about 1000-1500 cp at 25 ° C.
Anionic dispersions having an average resin particle size of s, in particular 1250 cps and smaller than about 1 μ are particularly suitable.

Another preferred resin emulsion is an anionic aqueous dispersion having a solids content of hydrogenated methyl ester of rosin of about 55%, a viscosity at 25 ° C. of about 1500 cps and an average resin particle size of less than 1 μ. is there. Another further advantageous resin emulsion has a solids content of slightly colored aliphatic hydrocarbon resin of about 55% and a viscosity at 25 ° C. of about 800 cps.
And an anionic aqueous dispersion having an average particle size of less than about 1 micron. Yet another advantageous resin emulsion has about 55% solids of alkaryl hydrocarbon resin, 25
Anionic aqueous dispersion having a viscosity at 3000C of about 3000 cps and an average resin particle size of less than about 1μ.

It is also possible to use any other suitable aqueous dispersion of low molecular weight aliphatic hydrocarbon resins or mixtures thereof. Advantageous commercially available resin emulsions include Hercules
Incorporated, Resins Group, Hercule Plaza, Wilmington, DE 19894 (He
rcules Incorporated, Resin
s Group, Hercules Plaza, Wis
lington, DE19894),
Piccopal, 85-55WKX,
Foral 85-55WKX, Hercolyn D-55WKX, Piccotac 95-55WK, Picobar (Pi)
covar) AP25-55WKX and Stybelite Ester 10
-55WKX and the like and mixtures thereof.

Any suitable tackifier can be used in the compositions of the present invention. Generally about 0.05 to about 2%
Is advantageous. The tackifier extends the feasibility of the composition of the present invention and allows for an increased amount of ground rubber to be used, thereby allowing a substantially double air bleed effect without compromising the adhesive capacity. To help. A preferred tackifier is N-ethyl-N-hydroxyethanamine.

Any suitable thickening agent may be used in the coating composition of the present invention to help keep the ground rubber fill in suspension. Generally, up to about 40% by weight thickener can be used, preferably about 0.1 to about 20.
Use weight percent. Examples of suitable thickening agents that can be used are polyacrylic acid, sodium carboxymethyl cellulose, xanthan gum, bentonite, starch, synthetic gums, water-soluble cellulose derivatives such as hydroxyethyl cellulose, methyl cellulose, methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose,
Methyl ethyl cellulose, methyl hydroxyethyl cellulose and the like and mixtures thereof. Xanthan gum, carboxypolymethylene and average molecular weight of about 20
Acrylic acid polymers (including copolymers) having 0000 to about 50,000,000 are particularly advantageous. In the case of polyacrylic acid thickeners, an effective amount of caustic or any other suitable base is added to neutralize acidity and promote thickening.

In an advantageous embodiment of the invention, any surfactant can be used as such and / or as a dispersant and / or wetting agent. Such compounds are
When dissolved in water or an aqueous solution, it reduces the surface tension, or the interfacial tension between two liquids or between a liquid and a solid (surfactant), or of very fine, often colloidal-sized solid particles. It promotes uniform and maximal separation (dispersant) or reduces the surface tension of water to allow water to more easily penetrate or spread on other substances (wetting agent). Generally, about 0.01 to about 5.0% by weight of these components, preferably about 0.3 to about 3% by weight, are used for each application.

Suitable materials from which surfactants, dispersants, wetting agents and the like may be selected in the practice of the present invention are any suitable anionic surfactant and certain nonionic surfactants. Includes activator. Suitable anionic surfactants which can be used are, for example, amine dodecyl benzene sulphonate, sodium alkylaryl polyether sulphonates, alkyl ether sulphates, alkyl sulphoacetates, ethylene oxide adducts of nonylphenols having 4 to 15 ethylene oxide groups per molecule. Partial salts and analogues of the phosphate esters of and mixtures thereof.

Suitable nonionic surfactants which can be used are, for example, the condensation products of higher fatty alcohols with ethylene oxide, such as the reaction products of oleyl alcohol with 10 ethylene oxide units, the condensation products of alkylphenols with ethylene oxide, Examples are reaction products of isooctylphenol with 12 ethylene oxide units, condensation products of higher fatty acid amides with 5 or more ethylene oxide units and the like and mixtures thereof.
Aminododecylbenzene sulfonate, sodium carbonate and oleic acid are preferred as surfactants, dispersants and / or wetting agents.

Any suitable bactericide and / or preservative may be used
It can be used in the coating composition of the present invention. Generally, from about 0.05 to about 2% by weight of bactericide and / or preservative,
About 0.15 to about 0.5% by weight is preferably used. Suitable disinfectant / preservative materials that can be used include, for example, 1,2
-Benzisothiazolin-3-one, 1,2-dibromo-2,4-dicyano-butane, 10,10-oxybisphenoxyarsine, 6-acetoxy-2,4-dimethyl-1,3-dioxane, 3 , 5-Dimethyltetrahydro-1,3,5,2H-thiadiazin-2-thione and analogs and mixtures thereof. Preference is given to using 1,2-benzisothiazolin-3-one and 3,5-dimethyltetrahydro-1,3,5,2H-thiadiazin-2-thione and mixtures thereof.

It is also useful to include a sequestrant in the composition of the present invention to sequester the ions present or liberated from the ground rubber fill and to maintain a stable coating composition. EDTA / polyacrylic acid type additives and B.I. F. Goodrich Company, Specialty
Polymers and Chemicals Division, Claverland, Ohio 44131 (BF Goodr)
ich Company, Specialty Pol
ymers & Chemicals Divisio
No., Cleveland, Ohio 44131) manufactured by Goodlight K-700 High Performance Polymer (GOODRITE K-700 hi.
The sodium salt of powdered polyacrylate known as K-7058D is preferred. Generally, about 0.03 to about 6% by weight of sequestering agent is used, preferably about 0.1 to about 3% by weight.

Other ingredients which may be used in the composition of the invention to enhance its performance are colorants, foam control agents, shear stabilizers and other stabilizers and the like and mixtures of any of these. is there. While any suitable ingredient can be used in any suitable amount, an advantageous ingredient that enhances the unexpected advantages of the present invention is a 10-50% aqueous dispersion of subdivided carbon black as a colorant. In an amount in the range of about 0.1 to about 2% by weight; hydrophobic silica with dimethylpolysiloxane emulsion as a cell regulator and mineral oil, preferably in the range of about 0.01 to about 0.4% by weight. N-ethyl-N-hydroxyethanamine as a tackifier, preferably in an amount ranging from about 0.05 to about 2% by weight; emulsion stabilizers and shear stabilizers and known in the literature. Other stabilizers, ammonium caseinate and sodium lauryl sulfate, are included in any suitable amounts.

It is also possible to use any suitable filler known in the literature, such as lamp black, hydrous magnesium silicate, carbon black, mica, talc, aqueous silica, sodium fluoroaluminate and the like and mixtures thereof. .. Unsaturated compounds known in the art, rubber latices, curatives and other treating agents can also be added if desired to improve adhesion at elevated temperatures.

The coating composition of the present invention can be applied to the substrate by any conventional coating method such as dipping, roller coating, spraying and the like. The paints are generally coated with any suitable paint spray type equipment in the desired amount of paint for the desired application, dry weight per square inch of substrate surface preferably 0.003 to 0.02 g, more preferably 0.0
It is advantageous to spray at a spray rate sufficient to apply 04-0.008 g. The advantageous range is dictated by the requirement that sufficient paint be present to provide a suitable air bleed without being used in such a large amount that adhesion is lost. Generally, the amount applied is equivalent to the amount applied when a thin coating is applied to the raw rubber surface by paint brush, but the amount of paint applied to the rubber surface varies. can do. The raw rubber product is then shaped and cured.

The composition of the present invention is applied to the tire surface,
When molded and cured, it remains on the tire surface as the outer tire paint. When the composition of the present invention is applied to a cloth lined substrate, the backing cloth will probably act as a stabilizer to prevent possible bond distortion and to prevent tearing of poorly bonded areas. As a result, an intensified result is obtained.

When used as an adhesive, it is only necessary to apply the composition of the invention to one of the surfaces to be bonded before bringing the surfaces together and curing or vulcanizing as described above. Is.

The coating of the present invention is compressed and heated against the metal walls of the mold for molding and curing, thus allowing air to escape from the outer surface of a rubber article, such as a tire.
Otherwise air may be trapped between the outer wall of the tire and the mold. As a result, bubbles can harden in the tire and appear as depressions in the tire sidewall. When using the paints of the present invention, other drawbacks that do not lubricate the walls that may result from the lack of lubricity to remove the tire walls from the metal during cure are eliminated.

[0045]

The invention is explained in more detail by the following examples, in which all "parts" and "%" are "parts by weight" and "% by weight" unless otherwise stated. ..

Example 1 Preparation of Starting Material A sidewall rubber is used which has a relatively close roll-roll spacing (eg 1/8), which is commonly used for its application.
2-roll rubber mill (2-ro
Milling with a continuous belt of rubber on one roll and enough rubber compound to provide a modest excess of rubber (bank) on between the rolls in an ll rubber mill). .. This milling continues for about 5-10 minutes until the rubber is soft and smooth. Once the rubber is sufficiently soft, open the mill at the predetermined indicia intended to give the finished slab of the desired thickness (3/16 inch). Then
With this gap setting, the rubber is made into a relatively uniform sheet and taken out of the mill. Approximately 5 x per sheet thus obtained
Cut into 4 pieces measuring 6 inches. The actual final size of each slab depends on whether it is used with or without a backing. If this slab is to be used without a backing, it is adjusted to a weight of 110-125 g.
If the slab is used with a backing fabric, the weight is adjusted to 75-90 g.

The cured and / or uncured bulk rubber material may be in any of several existing commercial processes (eg dry milling, wet slurry milling, cryogenic milling, etc.) or any other suitable means. To produce a ground rubber by classifying into a suitable particle size.

The first coating composition comprises about 277. deionized water.
3 parts, amine dodecyl benzene sulfonate about 2.6
Part, Amco windshield material (Aamco windshi
Ground rubber (Mid produced by grinding eldwiper stock) to 80-100 mesh
West Elastomers, Inc. , Wapa
koneta, O, 45895, grade ME 8
0/100) about 37 parts, 12% colloidal silica dispersion about 4.8 parts, 15% ammonium caseinate (ammon
ium caseinate) about 2.4 parts, 50% caustic soda (NaOH) solution about 0.4 parts, xanthan gum as a thickener about 1.7 parts, 29% sodium lauryl sulfate solution about 0.2 parts, molecular weight about 200,000 ~ About 5000
00, pH about 9.8, and total solids content about 62% 1,3
-Natural rubber latex of butadiene, 2-methyl homopolymer (Hartex 103, Firestone S
ynthetic Rubber & Latex C
o. , Akron, O, 44301, Lot # 68
6) About 40.7 parts, SBR latex about 13.8 parts, oleic acid about 1.43 parts, 1.2 as a fungicide / preservative.
-Benzisothiazolin-3-one about 0.3 parts and 12
% Polydimethylsiloxane foam modifier by mixing about 0.07 part. The air bleed property of this composition is calculated to be 0.98-1.

The second coating composition comprises about 590 deionized water.
Part, about 1.5 parts of amine dodecyl benzene sulfonate,
Approximately 91.5 parts of the same ground rubber used in the first paint,
A 55% solids solvent-free anionic dispersion of a low molecular weight aliphatic hydrocarbon resin mainly derived from dienes and reactive monomers, having a viscosity of 1250 cps at 25 ° C. and a resin particle size of less than 1 μ (Piccopale 8).
5-55WKX from Hercules In
c. , Resins Group, Wilmingto
n, DE 19894, Lot # 8EBA277) and about 3.5 parts of xanthan gum. The air bleed property of this composition is calculated to be 1.27-1.

The third coating composition comprises about 57.5 deionized water.
Parts, molecular weight of about 200,000 to about 500,000, pH of about 9.8, and total solids content of about 62% 1,3-butadiene, 2-methyl homopolymer natural rubber latex (first
Same as used in paint composition) about 100 parts, 25
55% solids solvent-free anionic dispersion of a low molecular weight aliphatic hydrocarbon resin mainly derived from dienes and reactive monomers having a viscosity of 1250 cps at 1 ° C. and a resin particle size of less than 1 μm (second coating composition Manufactured by mixing about 60 parts (same as used in the product). This composition does not have the air bleed properties calculated as above.

The fourth coating composition comprises about 590 deionized water.
Parts, about 7.5 parts of amine dodecyl benzene sulfonate,
Molecular weight about 200,000 to about 500,000, pH about 9.8
And a natural rubber latex of 1,3-butadiene, 2-methyl homopolymer having a total solids content of about 62% (first
Same as used in coating composition) about 61.5 parts, 2
55 of a low molecular weight aliphatic hydrocarbon resin derived mainly from dienes and reactive olefin monomers having a viscosity of 1250 cps at 5 ° C and a resin particle size of less than 1μ.
% Solids solvent-free anionic dispersion (same as used in the second coating composition) and about 129 parts filler / replacement lamp black for ground rubber. To manufacture. The air bleed properties of this composition are:
Calculated as 06-1.

The fifth coating composition comprises about 331.
6 parts, amine dodecyl benzene sulfonate about 1.5
Parts, about 91.5 parts of ground rubber of the first coating composition, a molecular weight of about 200,000 to about 500,000, a pH of about 9.8 and a total solids content of about 62%, 1,3-butadiene, 2-methyl homopolymer. About 28.6 parts of natural latex (same as used in the first coating composition), viscosity 1 at 25 ° C.
A 55% solids solvent-free anionic dispersion of a low molecular weight aliphatic hydrocarbon resin mainly derived from dienes and reactive olefin monomers having a resin particle size of 250 cps and less than 1 μm (in the second coating composition) (Same as used for) about 72.8 parts and about 3.5 xanthan gum.
The parts are mixed and manufactured. The air bleed property of this composition is calculated to be 1.33-1.

The sixth coating composition is approximately 931 deionized water.
2.5 parts, amine dodecyl benzene sulfonate about 19
9.2 parts, 1.7% polyacrylic acid thickener solution (MW =
1250000) about 2029.3 parts, a 51% solution of a sodium salt of polyacrylate sequestering agent about 91.
3 parts, 120 mesh ground rubber (Rouse Rub
ber Co. , Vicksburg, MS, 3918
1, GF-120 Lot # 127) about 3084 copies, 5
About 228 parts of 8% ammonium hydroxide solution, about 9.2 parts of 12% dimethylpolysiloxane foam regulator, about 20 molecular weight
Natural latex of 1,3-butadiene, 2-methyl homopolymer having a 0000 to about 500000, a pH of about 9.8 and a total solids content of about 62% (Hartex 103,
Lot # 114) Approximately 1604.9 parts, viscosity of 12 at 25 ° C
A 55% solids solvent-free anionic dispersion of a low molecular weight aliphatic hydrocarbon resin mainly derived from dienes and reactive monomers having a resin particle size of 50 cps and less than 1 μ (Piccopale 85-55WKX,
Lot # 9EB2105) about 1750.0 parts, about 162.6 parts of a 20% aqueous dispersion of lamp black, about 50.7 parts of a 50% solution of 1,2-benzisothiazolin-3-one as a fungicide / preservative. , About 238.0 parts of 15% ammonium casein ammonium solution, about 7.1 parts of 29% sodium lauryl sulfate solution, about 9.3 parts of 50% sodium hydroxide solution and about 78.6 parts of oleic acid. .. The air bleed properties of this composition are calculated to be 1.12-1.

The seventh coating composition comprises about 493.
8 parts, amine dodecyl benzene sulfonate about 7.5
Parts, about 190.8 parts of the same ground rubber as used in the sixth coating composition, about 2.5 parts of powdered sodium salt sequestering agent of polyacrylate, polyacrylic acid thickener (M
W = 1250000), about 80.4 parts of a 1.7% solution, about 2.7 parts of N-ethyl-N-hydroxyethanamine as a tackifier, about 3.0 parts of a 20% aqueous dispersion of lamp black. , 6.4 parts of 58% ammonium hydroxide solution,
Molecular weight about 200,000 to about 500,000, pH about 9.8
And a natural latex of 1,3-butadiene, 2-methyl homopolymer having a total solids content of about 62% (GNL1
50, Goodyear Tire & Rubber
Co. , Akron, O, 44316, Lot # 38
7) About 36.5 parts, viscosity at 25 ° C. of 1250 cps and 1
55% Solids Solvent-Free Anionic Dispersion of Low Molecular Weight Aliphatic Hydrocarbon Resin Derived Predominantly from Diene and Reactive Olefin Monomers with Resin Particle Size Below μ (Piccopale 85-55WKX, Her
cules Inc. , Resins Group, W
ilmington, DE, 19894, Lot # RE
F3127) about 23.7 parts, about 1.5 parts of 1,2-benzisothiazolin-3-one as a fungicide / preservative,
About 0.3 parts of 12% dimethylpolysiloxane foam control agent and 3,5-dimethyltetrahydro-1,3,5,2H thiadiazin-2-thione 0.8 as a bactericide / preservative.
The parts are mixed and manufactured. The air bleed property of this composition is calculated to be 3.49-1.

The coating compositions are all about 20 to 3 solids.
Contains 0%.

Example 2 Preparation of Coated Sample The above composition was applied to smooth one side of a rubber slab prepared as described in Example 1 at about 0.00 per square inch.
To apply a coating weight of 3 to about 0.01 g (measured after coating and drying for about 1 hour), about 0.025 to 0.1
Spray using a commercial paint sprayer equipped with an inch liquid nozzle. From Compositions 1-7, each about 0.003, 0.008, 0.007 per square inch,
0.006, 0.005, 0.004 and 0.006g
A dry coating weight of

To obtain each slab, 5 × 6 × 0.
002-inch Mylar Sheet (Mylar Shee
t) was manufactured and the sheet was evenly spaced over a dimension of 6 inches with three 1 × 3 inch windows leaving a 1.5 inch margin above the window and below the window. Leave a 0.5 inch margin, leaving 0.5 inch margins on each side. The mylar sheet is placed on an uncoated sidewall slab to match each 5x6 inch dimension. The slab with mylar sheet is then combined with the coated sidewall slab. The mylar sheet provides windows that define areas where adhesive bonds can occur between the slabs brought together.

If a textile material is used as the backing (see below), it is applied to the side of the rubber slab that has not been combined with the second rubber slab. The dimensions of the fabric material should be about 6.6 x 6 inches parallel to the 6.6 inch sized fabric strands. The cloth material is (1) such that both pieces have the same 6-inch dimension (ie, the strands of cloth material are parallel to the 5-inch dimension of the rubber slab) and (2).
The 6 inch edge of the fabric material is aligned on the rubber slab so that it is flush with the corresponding edge of the rubber slab.
The cloth material that has run off the edge of the rubber slab is wrapped around the edge so that it spreads about 1.3 inches across the opposite side of the rubber slab. The 1.5 inch margin of the Mylar window sheet (described above) is positioned to match the edge of the rubber slab wrapped with the cloth material. This extra fabric material strengthens the test sample where it is clamped with the jaws of the Peel Tester.

The fabric material backing for the assembled test slab reinforces and stabilizes the dimensions of the joint during the peel test, ie prevents elongation and constriction of the joint area under tension. This provides a slightly improved apparent adhesion for the composition given on the sample without the backing.

The total weight of the combined sidewall pieces is about 220 to about 250 g.

Example 3 Curing of Coated Specimen A Wabash automatic hydraulic press with a 22 inch by 18 inch heated plate was run at about 340.
Preheat to a temperature of ° F. A mold simulating tire building conditions with curing pressure and heating to provide only the clamping force, while the required pressure for curing is provided by superheated steam or nitrogen compressed to about 150 psig at about 340 ° F.
Preheat for 15 minutes. The preheated mold is opened and the rubberized sidewall assembly to be tested is placed in each of the two depressions in the mold. The mold is assembled and placed in the press, then the press is closed and the mold is adjusted to exert a closing force of about 5 t to clamp and seal. The mold is then connected to the pressurized gas line. Close the vent valve and slowly raise the pressurized gas to about 150 psi. No leak of pressurized gas occurs.

The sample is cured at a pressure of about 150 psig and about 340 ° F. for about 15 minutes. Once cured,
Close the pressurized gas valve and leave the vent valve open until all the gas is released. Then close the vent valve, remove the hose to the mold, remove the mold and remove the sample.

Example 4 Testing of Cured Samples Three test strips approximately 2 inches wide and 5 inches long were cut from the cured sample along the 5 inch dimension (ie, parallel to the 3 inch dimension of the mylar window). Each of the three Mylar windows is approximately in the center of a two inch width of the corresponding test strip. The end of the test strip is pulled apart to free the end of the strip that should be in the peel tester jaws.

Then, each sample was tested by Instron (Inst
ron) Install in a peel tester and peel at 180 degrees with a 2 inch jaw pull rate per minute. The 1-inch wide bond (corresponding to the 1-inch wide window of mylar sheet) is peeled off and the force per linear inch is recorded in pounds. At room temperature, Compositions 1-7 each have 3 lines per linear inch.
It exhibits peel forces of 3, 36, 220, 36, 215, 350 and 196 pounds. Samples 1, 2 and 4 show adhesive layer failure (ie poor adhesion) and samples 3, 5, 6 and 7 show adhesive failure (ie good adhesion). Samples 5, 6 and 7 represent compositions having a claimed combination of ground rubber, natural rubber latex and resin emulsion. Samples 1, 2,
3 and 4 represent selective compositions, for example sample 1 (with latex and milled rubber fill but no resin emulsion), 2 (with resin emulsion and milled rubber fill but latex). No) and 4 (with latex and resin emulsion but with lamp black instead of ground rubber fill) show poor adhesion, while sample 3 (has latex and resin emulsion but no fill at all). (Without agent) does not have air bleed capability.

For Samples 3, 5, 6 and 7, a thermal peel test is also conducted after the sample has been aged at 250 ° F for half an hour before being installed in the peel tester. The sample is then heat stripped at a jaw pull rate of about 2 inches per minute. Compositions 3, 5, 6 and 7 were 150 and 1 per linear inch, respectively.
It exhibits a heat peel strength of 82, 221, and 155 pounds. All thermal delaminations showed adhesive failure.

Adhesive failure is the primary indicator of satisfactory adhesion. Sample 7, which shows the cohesive failure and has the highest air bleed, which is more than 2.5 times higher than the next highest in this series (Sample 5), is the most advantageous composition.

The composition 7 of Example 1 was subjected to a field trial,
The following results were obtained: The composition surprisingly provided excellent cured adhesion without sacrificing air bleed. 2. Very good molding properties are indicated by a well-finished tire appearance without defects or discoloration. 3. The cured product did not show surface imperfections as the composition provides suitable air bleed with excellent adhesion. Molded surface was free of residue due to good cure bond properties, tolerance to excess application and resistance to mold smearing. No air gaps as the very effective air bleed properties hinder trapped air, light, unfilled, etc. 6. 6. Good adhesion at tire joints and absence of bond failure due to lack of trapped air. 7. Excellent release of rubber from the mold as a result of the composition's extreme lubrication properties. Flex crack resistance as shown by wheel test evaluations at elevated temperature and ozone levels. The compositions of the invention are preferred over solvent-based products and water-based products in comparative tests. Drying time is reduced to approximately half that of conventional water-based compositions. No spray nozzle clogging.

In addition to the enhanced adhesive properties of the compositions of the present invention, which far exceed the total of the adhesive properties that any component of the compositions of the present invention may contain, they provide a defect-free product after curing. It also provides the air bleed needed to do so.
This very advantageous combination of properties is surprising. This is because the adhesive properties of conventional water-based compositions are significantly reduced or destroyed when sufficient filler is added to provide the required air bleed.

The comparative example above clearly illustrates this remarkable and surprising result. Composition 1, as shown in Example 1, has a latex and ground rubber filler,
Composition 2 has no resin emulsion and composition 2 has resin emulsion and ground rubber filling but no latex, while composition 4
Has latex and resin emulsion, but uses lamp black instead of ground rubber fill. All of these compositions show adhesive layer failure, which shows poor adhesion,
Composition 3, on the other hand, contains latex and resin emulsion, but no filler at all, has no air bleed capability. The unexpected benefit of the present invention, on the other hand, is demonstrated by the compositions of the present invention, Compositions 5, 6 and 7 which exhibit adhesive failure showing excellent adhesion and which have excellent air bleed properties.

When used as an adhesive, the composition of the present invention is advantageously applied on the uncured surface to be deposited at a dry coating weight of about 0.002 to about 0.01 g per square inch. And dry. These may be applied to one or both sides of the surface to be attached. Since the dry coating does not show significant tackiness, the uncured portion should be retained in proper alignment before and during heating / curing / vulcanization. However, because of the high air bleed properties of the compositions of the present invention, a separate step (eg, knitting) of removing air from the joint prior to the curing step is not necessary.
This is because the significant air bleed of paint / adhesive compositions bleeds air during cure.

Although the present invention has been described in sufficient detail above,
Such details are for illustration purposes only,
And without departing from the spirit and scope of the invention,
It is to be understood that variations can be made by one of ordinary skill in the art without going into the claims.

Continuation of front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08J 5/12 CEQ 9267-4F 7/04 CEQ 7258-4F C09D 121/02 PGU 8218-4J // B29K 21: 00 105: 24 (72) Inventor Howard El Brooks United States Ohio 43560 Sylvania Fredericksburg 6935

Claims (36)

[Claims] 1. A high adhesion coating composition for rubber substrates which provides high adhesion and proper air bleed during cure, which comprises a rubber latex and an amount of attrition effective to provide the air bleed. A highly adhesive coating composition for a rubber base material, which comprises an aqueous binder mixture with a resin emulsion containing rubber particles. 2. The composition of claim 1 containing from about 15 to about 70% solids. 3. About 4 to about 60% by weight of ground rubber, about 0.5 to about 15% by weight of rubber latex and about 1 to about 3 of resin emulsion.
The composition of claim 1 containing 0% by weight. 4. A composition according to claim 3, wherein the composition further comprises a dispersant, a thickener, a surfactant, a wetting agent, a bactericide / preservative or a mixture thereof. 5. The composition according to claim 4, wherein the composition further comprises a colorant, a tackifier, a defoamer, a shear stabilizer, a sequestrant or a mixture thereof. 6. The composition of claim 1, wherein the ground rubber has a particle size of at least about 50 mμ. 7. The composition of claim 6, wherein the ground rubber has a particle size of about 5 to about 400 microns. 8. The composition of claim 6, wherein the ground rubber has a particle size of about 20 to about 200μ. 9. The composition of claim 6 wherein the ground rubber contains up to about 2% separating agent. 10. A volume ratio of ground rubber to binder of about 2.5:
The composition of claim 1, having 1 to about 7: 1. 11. The composition of claim 10 which contains from about 4% to about 60% ground rubber particles. 12. The composition of claim 11 which contains from about 5% to about 40% ground rubber particles. 13. The composition of claim 1, wherein the rubber latex contains from about 15% to about 85% natural or synthetic rubber. 14. The composition of claim 13, wherein the latex contains from about 15% to about 70% rubber. 15. The composition of claim 13, wherein the latex provides about 0.3 to about 8% solids contained in the composition. 16. The composition of claim 15, wherein the latex provides from about 1% to about 5% rubber contained in the composition. 17. The composition of claim 1 wherein the resin emulsion contains from about 15% to about 85% natural or synthetic lower aliphatic hydrocarbon. 18. The composition of claim 17, wherein the resin emulsion contains about 30 to about 70% natural or synthetic lower aliphatic hydrocarbon. 19. The composition of claim 18, wherein the resin emulsion provides from about 0.3 to about 15% of rubber solids contained in the composition. 20. About 30 to about 85% of water, about 4 to about 4 of ground rubber
About 35%, rubber latex about 0.5 to about 15%, resin emulsion about 1 to about 30%, sequestering agent about 0.1 to about 3
%, Dispersant about 0.3 to about 3%, wetting agent about 0.3 to about 3%
%, About 0.1 to about 20% thickener, about 0.1% germicide / preservative.
15 to about 0.5%, colorants about 0.1 to about 2%, tackifiers about 0.05 to about 2.0% and foam control agents about 0.01.
The composition of claim 1 containing from about 0.4%. 21. A method of producing a rubber article having substantially no defects on the coated surface, which comprises coating the surface of an uncured rubber article with the aqueous coating composition of claim 1 and then coating the coated rubber. A method for producing a rubber product having substantially no defects on the coated surface, which comprises curing the product. 22. The method of claim 21, wherein the outer tire surface is coated with the coating composition, then molded and vulcanized. 23. The method of claim 21, wherein at least one rubber surface is coated with the coating composition, combined with another rubber surface to be adhered, and then cured to complete the adhesive bond. 24. The method of claim 21, wherein the coating contains about 4 to about 60% by weight ground rubber, about 0.5 to about 15% by weight rubber latex and about 1 to about 30% by weight resin emulsion. .. 25. The method of claim 24, wherein the coating contains about 15 to about 70% solids. 26. The method of claim 25, wherein the coating contains a thickening agent, a surfactant, a wetting agent, a bactericide / preservative, or any mixture thereof. 27. The method of claim 26, wherein the coating contains a colorant, a tackifier, a foam control agent, a shear stabilizer, a sequestering agent, or any mixture thereof. 28. The method of claim 21, wherein the coating contains ground rubber having a particle size of at least 50 mμ. 29. The method of claim 28, wherein the coating contains ground rubber having a particle size of about 50 to about 200 microns. 30. The paint is about 4 to about 60% ground rubber particles.
29. The method of claim 28, which comprises: 31. The method of claim 21, wherein the surface of the rubber product is pretreated. 32. The method of claim 31, wherein the surface is treated with an oxidant or UV radiation. 33. The paint comprises about 30 to about 85% water, about 4 to about 35% ground rubber, and about 0.5 to about 15 rubber latex.
%, Resin emulsion about 1 to about 30%, sequestering agent about 0.
1 to about 3%, dispersant about 0.3 to about 3%, wetting agent about 0.3
To about 3%, thickeners about 0.1 to about 20%, bactericides / preservatives about 0.15 to about 0.5%, colorants about 0.1 to about 2%, tackifiers about 0. 22. The method of claim 21, which contains .05 to about 2.0% and a foam control agent of about 0.01 to about 0.4%. 34. A vulcanized rubber product obtained by the method of claim 21. 35. A tire having a tire coating on the outside, obtained by the method according to claim 22. 36. An adhesive product obtained by the method of claim 23.