CS216931B2 - Paste on the base of water dispersions for joining the fibres with the substrates on the rubber base - Google Patents

Abstract

1. An adhesive based on aqueous dispersions for bonding fibres to rubber substrates, characterized by a combination of a) 100 parts by weight of dispersed butadiene/acrylonitrile rubber, b) 100 to 500 parts by weight of polyfunctional aromatic nitroso compounds, and optionally other auxiliaries, such a halogen-containing polymers and/or copolymers of (meth)acrylic acid esters and also emulsifiers, defoaming agents, dyes, pigments, antistatic agents.

Description

Aqueous dispersion-based adhesive for bonding fibers to rubber-based substrates containing 1000 parts by weight of dispersed butadiene acrylonitrile rubber and / or copolymers of vinylidene chloride and acrylic acid methyl ester, 100 to 500 parts of multi-functional aromatic nitroso compounds and optionally 50 to 300 parts of blocked or multifunctional isocyanates 100 parts of polyvinylpyrrolidone or water-soluble mixed polymers of vinylpyrrolidone and / or water-soluble phenolic resins of the resolph type and, as emulsifier, 5 to 50 parts of nonylphenol ethylene oxide and optionally 80 to 250 parts of carbon black.

dispersions for bonding fibers with substrates to

216931 '

The invention relates to adhesives for bonding fibers to rubber substrates based on aqueous dispersions, wherein the adhesives form solid bonds with both vulcanized and non-vulcanized materials. with unvulcanised rubber.

It is known to apply fibrous flakes to a wide variety of substrates, the flakes having to be bonded firmly to the substrate with a suitable adhesive. Suitable solutions for this purpose are, for example, aqueous solutions of adhesives based on urea or melamine resins, as well as plastic dispersions based on polyvinyl acetate, polyvinyl propionate and polyacrylic acid esters. High-quality glued joints can be obtained with solvent-based adhesives based on polyurethanes, optionally based on isocyanates and based on polyepoxide compounds. However, these adhesives must be used irrespective of the use of solvents as two-component adhesives and therefore have only a limited life in the can.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide aqueous dispersion based adhesives which form strong bonds with conventional flocculant materials and unvulcanized and vulcanized rubber, while having neither a limited life nor the use of solvents in their use.

According to the invention, the aqueous dispersion adhesive for bonding fibers to rubber-based substrates comprises 1000 parts by weight of dispersed butadiene acrylonitrile rubber and / or copolymers of vinylidene chloride and acrylic acid methyl ester, 100 to 500 parts of multifunctional aromatic nitroso compounds and optionally 50 to 300 parts of blocked multifunctional of isocyanates. and optionally 20 to 100 parts of polyvinylpyrrolidone, optionally a water-soluble phenolic resin of the resol type a, as an emulsifier, 5 to 50 parts of the nonylphenol ethylene oxide adduct and optionally 80 to 250 parts of carbon black.

In rubber-containing butadiene-acrylonitrile copolymers, the monomer ratio can vary within wide limits of 5 to 45% acrylonitrile. Suitable products are already commercially available as dispersions. They are often modified to additionally polymerize additional comonomers, such as vinyl chloride, vinyl acetate, styrene, and free acrylic or methacrylic acid. By selecting the comonomers and the amounts used, the properties of the polymers can be varied in the desired manner.

Dispersible rubbery polymers which can be used for the purpose of the invention are film-forming thermoplastics which have already been proven for coating fabrics, paper sheets and the like.

Suitable nitroso compounds for the production of the adhesives according to the invention can be derived from a wide variety of aromatic hydrocarbons.

Particularly suitable are aromatic poly-C-nitroso compounds having 1 to 3 aromatic rings, including fused ones, having 2 to 6 nitroso groups which are bonded directly to non-adjacent carbon ring atoms.

Preferred poly-C-nitroso compounds are dinitrosobenzenes and dinitrosonaphthalenes, such as meta-dinitrosobenzene or para-dinitrosobenzene and meta-dinitrosonaphthalene and para-dinitrosonaphthalene. The hydrogen atoms of the aromatic ring can be substituted by alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, arylamino, arylnitro, amino, halogen or the like radicals.

The presence of such substituents in the aromatic ring or in the aromatic ring has only a marginal effect on the activity of the poly-C 1-4 heterocycle. The following are suitable for the purpose of the invention: 2,5-dinitroso-p-cymene, 2-methyl-1,4-dinitrosobenzene, 2-methyl-5-chloro-1,4-dinitrosobenzene, 2-fluoro-l, 4-dinitrosobenzene, 2-methoxy-1,3-dinitrosobenzene, 5-chloro-1,3-dinitrosobenzene, 2-benzyl-1,4-dinitrosobenzene, and 2-cyclohexyl-1, 4-di-4-nitro ^ ltrosobenzene. Of course, nitroso compounds, namely oximes with oxidizing agents, can also be used.

The halogenated polymers optionally used as auxiliaries are also known per se in the adhesives industry, such as polymers of vinyl chloride or vinylidene chloride, optionally with comonomers such as acrylic acid, crotonic acid, alkyl ester of acrylic or methacrylic acid or acrylonitrile.

These polymers can also undergo further halogenation, in particular chlorination. Other excipients which may be mentioned are the water-soluble and water-dispersible mixed polymers of alkyl esters of acrylic or methacrylic acid having from 1 to 12 and in particular from 1 to 4 carbon atoms in the alkyl moiety. These compounds can also undergo partial saponification. Suitable comonomers for such polymers are, in particular, acrylamide.

According to a preferred embodiment, the adhesives additionally contain 50 to 300 parts by weight of blocked multifunctional isocyanates and 20 to 100 parts by weight of polyvinylpyrrolidone or a water-soluble mixed vinylpyrrolidone polymer, in each case based on 1000 parts by weight of butadiene acrylonitrile rubber. In addition, it may also be advantageous to use phenolic resins and / or melamine resins at the same time. .

The blocked multifunctional isocyanates are derived from technologically versatile commercial isocyanates. The so-called isocyanate group cleavers can, for example, be derived from. toluylene diisacyanate, naphthalenediisocyanate isophanane? diisocyanate, diphenylmethane diisocyanate; dimerized toluylene diisocyanate, hexamethylene diisocyanate and other numerous compounds such as multifunctional isocyanates such as triphenylmethane triisocyanate, or from the addition products of 3 moles of toluylene diisocyanate as well as 1 mole of trimethylolpnopamK as a means of blocking isocyanate groups; are suitable, for example: phenols, alcohols such as tert-amyl alcohol or tert-butanol, acetic acid ester, malonic ester; acetylacetone ,. butanonoxim ,. phthalimide, imiidazole or sodium hydrogen sulfide

Isocyanate group cleavers are produced at either room temperature; or optionally * at temperatures of about 100 ° C. Catalytic amounts of sodium * or alcoholate / sodium are required for the addition of compounds having reactive methylene groups such as malonic ester and acetic acid ester. Addition can? in the presence or absence of inert solvents.

Polyvinylpyrrolidone can be used either alone as a conventional technical product with a Sz value. It may comprise water-soluble mixed polymers such as vinyl acetate. Also suitable are copolymers of vinylpyrrolidone which contain, as comonomers, other vinyl esters, acrylic ester, methacrylester or acrylamide or methacrylamide, as well as light-weight vinyls. In particular, polymers with a higher K value also stabilize the dispersions.

Of course, mixtures of said compounds should contain known excipients. In addition to adhesion-enhancing resins or pre-steps. phenolic resin resins, alkylphenol resins, resorcinol resins, resols, novolaks are more reminiscent of condensation products from epichlorohydrin and from multifunctional phenols such as diphenylolpropane, styrene copolymer, and maleic anhydride and the like. Finally, the dispersions of the invention may also contain conventional adhesion promoters. Soot, silicic acid, zinc oxide, basic lead phosphite and the like fillers are suitable. If desired, pigments can also be incorporated.

Surfactants, in particular nonionic surfactants, are particularly suitable as dispersing aids. Suitable are, for example, ethylene oxide adducts of alkylphenols, such as nonylphenol or a fatty alcohol or a partial ester of a fatty alcohol with phosphoric acid. Water-soluble colloids such as methylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose and polyvinyl alcohol may also be used as dispersion stabilizers.

Can new adhesives be used to bond various flocculants? materials such as polyester flakes; of the poles? of amides or of artificial silk and cotton. These flocculant materials are; They can be used for various purposes and even the most demanding requirements for vulcanized. optionally to unvulcanized rubber. If: sw starts from an already vulcanized rubber, process? after application of the adhesive, it is usual for. plating. Evaporation of the water and the formation of the adhesive bond then occurs at elevated! temperatures of between 90 and 15 ° C; for 5 to 20 minutes. However, if the flocculation of the flake material on yet unvulcanised rubber is involved, does it heat up afterwards? hay flakes; under vulcanization conditions, which vary according to the composition of the rubber for 15 minutes to one hour at a temperature of 120 to 180 ° C.

The adhesives according to the invention may have a solids content such that they are even more easily spreadable and / or sprayable. The solids content should be about 20 to 50% by weight, and generally no organic solvents can be used, but they may be used in amounts, not more than 5% by weight, based on the liquid phase.

The use of the adhesives according to the invention) of obtainable flocked materials is generally known. For example, are the flocked rubber profiles used in cars? the mobile industry, about flocked mats ;. flexible; shafts, floor coverings in general, o rubber gloves, o; adhesive boards for demonstration purposes, o numbering rollers in the spinning machine industry, o textile tubes and the like.

Examples

In the following examples, the rubber mixtures designated A, B, C, D, are used. E and F. The following are compositions; blends and vulcanization conditions.

Mixture A (NR)

Weight parts

Natural rubber100

Carbon ¹ zinečnatýIQ

Stearic acid2

Phenyl-beta-naphthylamine1

Spruce pitch2

Carbon black CK 325

Zinc dimethyldithiocarbamate0,33

Dibenzothiazyldisulfide 0.58

Sulfur0.75

Vulcanization conditions: 10 minutes at 153 ° C

Stearic acid

Zinc oxide 5

Dlbutyiftalate 10

Carbon black SRF 65

Terpene resin 10

Tetramethyl thiuram disulfide 0.31

Sulfur1

Mixture В (SBR)

Weight parts

Styrene-butadiene rubber100

Zinc oxide5

Stearic acid1

FEF Sets (Corax 3) 50

Saturated polymeric hydrocarbons of petroleum (liquid) 8

N-Cyclohexyl-2-benzthiophthalimide 0.2

Benzthiazyl-2-cyclohexylsulfenamide 0.95

Sulfur1,6

Vulcanization conditions: 30 minutes at 153 ° C

Mixture C (CR)

Weight parts

Polychloroprene rubber100

Magnesium oxide4

Phenyl-beta-naphthylamine2

Carbon black MT (Sterling) 80

Hydrocarbons having a boiling point of 300 ° C1

Naphthenic oil5

Tetramethylthiurammonosulfide 0.5

Di-o-tolylguanidine 0.5

Ethylenthiourea0,5

Sulfur1

Vulcanization conditions: 30 minutes at 153 ° C.

Mixture D (NBR)

Parts by weight Nitrile rubber (42% acrylonitrile) 100

Vulcanization conditions: 25 minutes at 153 ° C.

By dispersing in water binders are produced from the following components:

1) Copolymer of butadiene acrylonitrile (30 why) and methacrylic acid (5%) as a commercial latex with about 55 to 58% solids (nitrile rubber).

2) Copolymer of polyvinylidene chloride and methyl ester of acrylic acid in the form of a commercial about 55% dispersion (PVDC / AM).

3) p-Diinitrosobenzene (DNB).

4) Phenolic resin (resol type, water insoluble) (resol).

5) Blocked isocyanate (reaction product of an adduct of 1 mole of trimethylolpropane with 3 moles of toluylenedilocyanate with butadienoxime) (isocyanate).

6) Polyvinylpyrrolidone (K value of 70) in the form of a 30% aqueous solution (PVP).

7) Addition product of 20 moles of ethylene oxide per mole of nonylphenol (emulsifier).

8) Zinc oxide.

9) Carbon black HAF.

10) Water.

Table I shows the composition of binder I to V depending on the individual components.

Table I

Binder I II III

Component

IV V

1) Nitrile

rubber - 228 - 843 - 2) PVDC / AM 1080 912 843 - 843 3) DNB 210 280 228 253 253 4) Resol - 42 - 42 - 5) isocyanate - - - - 168 6) PVP - - 28 28 28 7) emulsifier 8) oxide 12 15 Dec 15 Dec 14 12 zinc 12 12 8 8 8 9) soot 120 120 120 97 97 10) water 1580 1580 1600 1700 1700

Binders I to V listed in Table 1 were used for the coating. For this purpose, rubber sheets of 15 x 20 cm are made of natural rubber (mixture A - NR), styrene-butadiene rubber (SBR, mixture B), polychloroprene rubber (CR, mixture Cj and nitrile rubber (NBR, mixture D)) The surface of the rubber plates is cleaned by washing with xylene, coated with a coating to ensure adhesion and electrostatically coated.Flakers using 0.75 mm polyester inserts are used, and the adhesive is dried for about 10 minutes at 120 ° C. After about 10-15 hours of storage at room temperature, the flocked rubber parts are subjected to an abrasion test in a wear test apparatus, the results of which are shown in Table II.

T a b u lk and II

Adhesive Mixture A Number of cycles Mixture D Mixture B Mixture C AND 42 58 38 62 II 25 25 31 38 III 21 23 25 28 IV 37 46 38 42 IN 45 62 44 65 Rubber mixtures of NR (mixture of A), SBR After about 10 to 15 hours of storage at room temperature (mix B), CR (mix CJ and NBR (mix DJ room temperature the parts are tested layer by glue coating, electrostatically abrasion. 'Results are given in the table float and then they vulcanize in sus1c1 III. cabinet at 150 ° C for 60 minutes.

Table III

Adhesive Number of cycles Mixture A Mixture B Mixture C Mixture D AND 82 70 37 90 II 63 38 25 46 III 44 62 28 51 IV 52 65 42 58 in 76 49 48 63

ADD

Claims (1)

ADD Aqueous dispersion-based adhesive for bonding fibers to rubber-based substrates, characterized in that it contains 1000 parts by weight of dispersed butadiene acrylonitrile rubber and / or a copolymer of vinylidene chloride and acrylic acid methyl ester, 100 to 500 parts of multifunctional aromatic nitroso compounds and optionally 50 to 300 parts isocyanates and optionally 20 to 100 parts of polyvinylpyrrolidone, optionally water-soluble mixed polymers of vinylpyrrolidone and / or water-soluble phenolic resol resins and, as emulsifier, 5 to 50 parts of nonylphenol ethylene oxide adduct and optionally 80 to 250 parts of carbon black.