DE1594968C - Process for improving the adhesive strength of cord fabrics on vulcanized elastomers made from ethylene, alpha olefins and multienes or their vulcanized mixtures - Google Patents

Description

As is well known, articles are produced in the rubber industry which, on the one hand, consist of cross-linked Elastomers or mixtures of these elastomers with fillers, plasticizers, metal oxides, higher Fatty acids, vulcanizing agents and vulcanization accelerators as well as rubber auxiliaries and additives and on the other hand from textiles, such as. B. fibers or cord made of rayon, nylon or polyester.

The adhesive strength between the generally vulcanized is important for the quality of such articles Elastomer mixture and the fibers or cord and generally without the use special bonding agent is not sufficient.

Adhesion promoters are z. B. latex systems, with which the textiles before the joint processing with the elastomer mixtures are impregnated. A bonding agent that is widely used in the tire industry is a latex containing resorcinol-formaldehyde resin. This resin-latex mixture is obtained in the way that resorcinol is condensed alkaline with formaldehyde and the resulting aqueous Solution of the resinous condensation products combined with the rubber latex. The condensation can also be carried out in the rubber latex itself. Suitable latices are e.g. B. natural rubber latex and latexes from synthetic rubbers, such as. B. emulsion copolymers of butadiene and styrene. Such resin-latex combinations are generally not usable as adhesion promoters if the vulcanized elastomer mixture as an elastomer component, copolymers of ethylene with α-olefins and multienes, d. H. so-called "unsaturated ethylene-propylene rubber (APUK)" contains because here the adhesive strength is completely inadequate. As is well known, the reason for this lies partly in the different Vulcanization rates of ethylene-propylene rubber on the one hand and the On the other hand, polydiene rubber types which build up latices.

For this reason, the impregnation of textiles, such as. B. Cords in elastomer blends are vulcanized from copolymers of ethylene with α-olefins and multienes should only be done with adhesion promoters whose elastomer components are also made of unsaturated Copolymers of ethylene with α-olefins and multienes exist.

The task of the present method is now that by mixing the synthetic resin latexes with dispersions of z. B. polyvinylpyridine or polyoxazole improved adhesive strength further raise.

It has been found that the adhesive strength of cord fabrics on vulcanized elastomers Ethylene, at least one other -olefin and at least one multien or mixtures thereof by impregnating elastomers made from copolymers with latex containing resorcinol-formaldehyde resin of ethylene with α-01efin and multien and vulcanization into elastomeric compounds of copolymers from ethylene with α-olefins and multienes or their mixtures can further improve if one uses embedding compounds of these elastomers or their mixtures, the polydiolefins in one Amount of 0.01 to 10 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight the elastomers, optionally with other rubber auxiliaries and additives, added. As elastomers made of ethylene, at least one other α-olefin and at least one multien are To understand such elastomers or copolymers, the 35 to ^ 85 mol percent, preferably 50 to 70 mol percent Ethylene, 15 to 65 mole percent, preferably 30 to 50 mole percent propylene or α-butylene, and 0.1 to 20 mol percent, preferably 0.5 to 10 mol percent, of at least one multiene.

As a multi-purpose z. B. dicyclopentadiene, cyclooctadiene-1,5 and addition products of cyclopentadiene with multienes, such as B. butenylnorbornene into consideration.

The copolymerization is carried out in a manner known per se using Ziegler catalysts. This Elastomers can be used as such, as mixtures with one another and, accordingly, in a particularly advantageous manner Embodiment of the present process, in the form of their mixtures with other rubber auxiliaries or additives, such as. B. fillers, plasticizers, metal oxides, higher fatty acids and optionally Vulcanizing agents and / or accelerators and others in the rubber industry additives and auxiliary materials used will.

Polydiolefins to be used according to the invention are:

1. natural or synthetic polymers of 2-methyl-butadiene- (l, 3),

2. synthetic polymers of butadiene (1,3) or its copolymers with styrene or its homologues, like methylstyrene, as well as with acrylonitrile or

3. Synthetic polymers of 2-chlorobutadiene-l, 3.

The copolymers can be static or block copolymers be built up and are made by emulsion polymerization in the aqueous phase or by Obtained polymerization with organometallic mixed catalysts in organic solvents.

The aqueous latex used for the impregnation is obtained in such a way that one solutions the above-mentioned copolymers in hexane, heptane or benzene using a dispersing device, such as B. a high speed stirrer, in 0.1 to 5 times, preferably 0.4 to 1.5 times the amount of an aqueous Dispersed emulsifier solution.

. Anion-active substances are used as emulsifiers, preferably alkyl aryl sulfonates, alkyl sulfonates, alkyl sulfates and non-ionic compounds, such as. B. Condensation products of phenols and alcohols with ethylene oxide.

These surface-active substances can be used alone or in combination with one another and / or used with high molecular weight protective colloids such as polyvinyl alcohol, casein, glue and cellulose derivatives will. The amount of emulsifier is 0.1 to 1%, based on the polymer solution. The dispersion the copolymer solution takes place at room temperature.

After emulsification, the solvent introduced with the solution is distilled at atmospheric or reduced pressure. The latices that remain can be used according to any known method

3 4

Procedures are concentrated, such as. B. Distilling off d) Production of the resorcinol-formaldehyde

of water, addition of creaming agents or resin solution

Centrifuge. The last-mentioned methods are particularly recommended, as a large part of the excess emulsifiers in 195 g of distilled water are removed from 11 g of resorcinol. The latexes dissolved 5 and 20 g of 30 ° / _o formaldehyde solution as well as can improve the adhesion of a peroxidic 40 ° l / _o g sodium hydroxide solution added, with stirring groups contain z. B. added by a subsequent. This mixture is left to ripen for 16 hours in the dark at room temperature in a treatment with peroxides. The solution can be, or mixed, a polyvinylpyridine containing 6.4% resin solids. The molar ratio of dispersion can be used, the polymer io resorcinol to formaldehyde being 1: 2. weight ratio of APUK to polyvinylpyridine

can vary between 99: 1 to 70:30 and before · _e ) preparation of the impregnation mixture

preferably 95: 5 to 85:15.

The resorcinol-formaldehyde resin component is a 250 g under c) above 40 ° / ₀ aqueous latex

by condensation of resorcinol and formaldehyde 15 mixture of APUK latex and PVP dispersion obtained in aqueous alkaline solution. The ge are diluted with 84 g of distilled water and mixed with. weight ratio of resorcinol to formaldehyde can be 266 g resorcinol-formaldehyde resin solution d) under between 10: 1 and 1: 1 and is mixed with preferred stirring. The mixture contains .11.7% total wise 11: 6. The resin becomes solid in the amount of 2.5 to. The ratio of resin to APUK-Latex-Fest-50 Percentage by weight, preferably from 10 to 25%, is 18: 100 in this example. percent by weight, based on latex solids, used.

f) Testing the adhesive strength of the rubber-textile composite bodies

Example 1 _ ,.", , ,. ,. . . _.

25 cord threads run through an impregnation apparatus

under tension the impregnation mixture e) as well as a

a) Production of the APUK latex by a high-frequency heated tube in which the

Threads are dried. The thread take-up is

"10 kg of a 5 ° / _o by weight of a benzene solution about 6% dry substance, based on the thread-ethylene-propylene-dicyclopentadiene terpolymer, weight 30th

which contains 45 percent by weight propylene, in The dried threads are 20 minutes at

one under the trade name »Ultra-Turrax-Durch- 150 ⁰ C heated. The threads treated in this way are placed under a known dispersing device at room temperature of 1 kg in a mold in the embedding mixture in 10 kg of an aqueous emulsifier solution. The mold can accommodate 24 threads, which are surrounded by 70 g of tetrapropylenephenoltrigintaglycol ether, 10 g of 35 on both sides with 2 cm wide strips of the embedding mixtures specified according to a naphthalenesulfonic acid benzene sulfonate, 20 g of the above-mentioned embedding mixtures according to the tanyl-formaldehyde condensation product and 2 kg of belle 1. The pressure in the form of methanol contains dispersed. From the obtained is about 20 kg / cm ² ; it is emulsion by spring washers, the benzene is removed by distillation. kept constant. Vulcanization takes place at 170 ° C. for 1 hour. The about 7 to 8% solid latex is concentrated by dividing the vulcanized content by 40 to 60%. Composite strip. After the temperament is complete

tion of the pieces of rubber at 80 ⁰ C, the adhesive strength of the vulcanized cord with a

b) Production of the polyvinylpyridine dispersion 45 tearing machine determined. Since the vulcanized

Thread length is 20 mm, the adhesive strength is in

200 g of freshly distilled vinyl pyridine are given in kg / 20 mm. The stated values are 800 cm ^{3 of} water containing 4 g of tetrapropylene benzene sulfonate mean values from at least six individual tests, 10 minutes and after adding 4 g of a. The dynamic test is carried out in a suitable "

Mixture of 75% tert-butyl hydroperoxide and 25% 50 apparatus (for example Bayer, messages for the di-tert-butyl peroxide for a further 2 minutes in a rubber industry, no. 29 ·, 73) at 8O ⁰ C carried "Ultra-Turrax through-flow device" dispersed. The emul- leads. The time is determined in minutes after sion is required at 20 ° C. with 40 cm ^{3 of} a 10% strength aqueous alternating load to add the one-tetraethylene pentamine solution. The polymerisation vulcanized cord from the Einbettmischung to sation level is also 20 ⁰ C. After 55 solve. The 6 hours is the end of the reaction from at least six individual values. The latex has a mean value. The cord used is S / S rayon, with a solids content of 20%. Td 1650/2, 480/480 ZS used.

Table 2 shows the test values for the static and dynamic cord adhesion test of the values given in Table 1.

c) Production of a latex mixture 60 given mixture A of the Mi according to the invention

Schung B compared. In these mixes

the impregnated cords are embedded by blending those produced according to a) and b). As. Latexes, mixture B contains natural rubber,

this being in the form of a mixture of structure C

2000 g of a 45% copoly-65 produced under a) in an amount of 0.5%, based on elastomer merisatlatex are used while stirring with 500 g of the hydrocarbon. The improvement 20% polyvinylpyridine dispersion b) combined. The test values for B versus A are clear from this Solids content is 40%. to see.

Table 1

Mixture IDI

Unsaturated ethylene-propylene rubber, oil-coated.

Oil content: 37.5 parts of naphthenic mineral oil to 100 parts of unsaturated ethylene-propylene rubber, dicyclopentadiene to caoutchouc-KW approx. 4 percent by weight C ₃ content: approx. 45%
Mooney value (ML-4) at 100 ° C: about 45%

Unsaturated ethylene-propylene rubber, not oil-coated.
C ₃ content: about 45%
Dicyclopentadiene content: about 4 percent by weight

Mooney value (ML-4) at 100 ° C: about 45%

Natural rubber, sheets, Defo 1200

Butadiene-styrene cold rubber, type 1500 Polybutadiene rubber, cis content > 95%

HÄF carbon black

SRF soot

Zinc oxide

Stearic acid

Phenyl - /? - naphthylamine

N-phenyl-N'-isopropyl-p-phenylenediamine

Ozokerite

Aromatic mineral oil

Sulfur 1

Tetramethylthiuram monosulfide

Table 2

73.5

26.5

15.0

20.0

140.3

mixture 'Cord adhesion
static (kg / 2 cm) dynamic (min.) A.
B. 7.5
8.1 160
270

Example 2

The manufacture of the impregnation latex, the resin-latex mixture, the impregnation of the threads, the The test specimens are produced and the test is carried out as described in Example 1. Instead of natural rubber or the natural rubber mixture is here, however, a mixture of butadiene-styrene-cold rubber of type 1500 used. The mixture structure of the mixture D used in table shows that the amount of butadiene-styrene cold rubber used is the same, namely 0.5%, as that in example 1 is for the natural rubber. Here, too, the butadiene-styrene cold rubber is used as in Example 1 applied by adding a mixture with the structure E. The improvement of the adhesion values Mixture D versus Mixture A can be seen from Table 3.

Table 3

mixture Cord adhesion
static (kg / 2 cm) dynamic (min.) A.
D. 7.5
7.8 160
245

73.5 -

26.5 -

0.500

■ 15.238
20.0
3.015
0.001
0.005
0.005
0.005
0.040
1.0
1.3

141.109

- 73.5 - 73.5 - 26.5 - 26.5 100.0 - 0.500 100.0 - - - - 0.500 47.5 15.238 47.5 15.238 - ' 20.0 - 20.0 3.0 3.015 3.0 3.015 2.0 0.001 2.0 0.001 1.0 0.005 1.0 0.005 1.0 0.005 1.0 0.005- 1.0 0.005 1.0 0.005 8.0 0.040 8.0 0.040 - 1.0 - 1.0 - 1.3 - 1.3 163.5 - 141.108 163.5 141.108

100.0 47.5

3.5 2.0 1.0 1.0 1.0 8.0

163.5

Example 3

In analog form as in the ■■ Example 2 This example describes the use of the invention PoIybutadien rubber - prepared by Ziegler - with a cis content of at least 95% with the aid of mixtures of F and G. Table 4 -Is in a manner analogous to the static and dynamic cord adhesion test values obtained in this way for comparative mixture A, from which the improvement of mixture F with regard to cord adhesion compared to mixture A can also be seen.

Table 4 . dynamic (min.) mixture . Cord adhesion
static (kg / 2 cm) 160
245 55:
A.
F. 7.5
7.8.

Claims (2)

Patent claims: 1. Process for improving the adhesive strength of cord fabrics on vulcanized elastomers of ethylene, at least one other α-olefin and at least one multiene or mixtures thereof by impregnating the cords with latex containing resorcinol-formaldehyde resin Elastomers made from copolymers of ethylene with α-olefin and multien and vulcanized into Elastomer compositions of copolymers made from ethylene with α-olefins and multienes or their mixtures, characterized that embedding compounds of these elastomers are used, the polydiolefins in an amount from OjOl to 10 parts by weight, based on 100 parts by weight of the elastomers, optionally in Form of their mixtures, added included. 2. The method according to claim 1, characterized in that the polydiolefins in the form their mixtures with fillers, plasticizers, metal oxides, higher fatty acids and optionally Vulcanizing agents and / or vulcanization accelerators and others in the rubber industry used additives and auxiliary materials are used. 209 610/110