DE1259093B - Process for firmly bonding polyterephthalic acid ester fibers with natural or synthetic rubber - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN wjw PATENT OFFICE

EDITORIAL

Int. CL.

C 08 c

C08d
German KL: 39 bi

Number: 1259 093

File number: C19484IV d / 39 b

Filing date: July 27, 1959

Opening day: January 18, 1968

There are already many methods of making Articles made from reinforced vulcanized rubber or rubber substitutes using Threads, fibers, yarns, fabrics and the like made from e.g. B. cotton, rayon, polyamides and silk are known. These reinforced rubbers are used in the manufacture of all kinds of objects, such as tires, Drive belts, conveyor belts, hoses or balloons, which are generally hard Are subject to operating conditions.

Because of its outstanding properties in terms of tensile, flexural, heat and abrasion resistance It has already been proposed to use textiles made from polymethylene terephthalates, in particular rubber Polyethylene terephthalates, to reinforce. However, it has not previously been possible to use these polyesters in to combine with rubber in a satisfactory way. On the one hand there are binders such as aqueous dispersions from vinylpyridine copolymers and resorcinol-formaldehyde resins, their technical usefulness for the connection of rubber with polyamide fibers has been proven, here unsatisfactory results, on the other hand have binders based on polyisocyanate adhesives, with which polymethylene terephthalates Rubber can be firmly bonded for various reasons, such as the toxicity of the adhesive and difficulties associated with the solvents required for this adhesive, none Found widespread in industry.

The invention relates to a method for firmly bonding polyterephthalic acid ester fibers with natural or synthetic rubber by impregnating the fibers with aqueous dispersions, which contain resorcinol-formaldehyde resins and vinylpyridine copolymers, embed the dried Fibers into a vulcanizable rubber mixture and vulcanizing the so reinforced Rubber, which is characterized in that before treatment with the aqueous rubber-resin dispersion a treatment with a paste or dispersion made from polyvinyl chloride or copolymers made of vinyl chloride and vinyl acetate or vinylidene chloride.

The drying of the two coatings is preferably carried out by the application of heat.

Polymethylene terephthalates are esters of glycols of the formula HO (CH ₂ ) »OH, where η is a number from 2 to 10, or cycloaliphatic glycols with terephthalic acid or mixtures thereof with isophthalic acid.

The homopolymers or copolymers of vinyl chloride to be used according to the invention are in solution,

Method for firmly connecting
Polyterephthalic acid ester fibers with natural or
Synthetic rubber

Applicant:

Canadian Industries Limited, Montreal (Canada)

Representative:

Dr.-Ing. H. Fincke, Dipl.-Ing. H. Bohr

and Dipl.-Ing. S. Staeger, patent attorneys,

8000 Munich 5, Müllerstr. 31

Named as inventor:

Roger Gordon Aitken,

John Aitken Caskie,

Gordon Hart Segall, St. Hilaire Station, Quebec (Canada)

Claimed priority:

Great Britain July 28, 1958 (24196),

dated April 29, 1959 (14 600) - -

used as a plastisol, as an organosol or as a dispersion, but preferably in the form of emulsions. Generally, a plasticizer such as 2-ethylhexyl phthalate is used added to the mixture of the first coating. Suitable diluents such as polyvinyl acetate or stabilizers, can also be added.

The dispersion used for the second coating consists of a mixture of butadiene-vinylpyridine-styrene copolymers and resorcinol-formaldehyde resins.

The first coating of vinyl chloride homo- or copolymers, dried under the action of heat serves to improve the adhesion of the second coating as an adhesive for the one to be vulcanized Rubber. The rubbers used are natural rubber, including gutta-percha and balata, synthetic diene polymers and copolymers of chlorobutadiene, butadiene-styrene copolymers and butadiene-acrylonitrile copolymers, polysulphide rubber, isobutylene homo- or copolymers, used.

The application of the coatings to the fiber material can be done in any suitable way,

709 719/445

preferably by dipping the fiber material loosely or under tension into the coating mixture or by spraying or brushing. If the desired thickness of the coating (at least 1% by weight and preferably from 3 to 25 weight percent solid coating based on the weight of the fiber can not be applied in one treatment step, the impregnation of the textiles several times to achieve the desired thickness of the coating.

The manufacture of tire cord requires that the cord should be pretreated in order to reduce its tendency to stretch under load or to shrink as the rubber vulcanizes. This can be achieved by heating the cord to a temperature of 200 ^° C. for _{approximately V 2 minutes under tension.} This heat pretreatment is expediently carried out together with the heat treatment of the first coating.

The following examples illustrate the invention. Parts given relate to weight.

The tire cord used in the examples was made of polyethylene terephthalate by a 48-thread yarn spun, the yarn drawn, four of these yarn threads twisted into a strand and eventually two of these strands were doubled into approximately 2100 denier cord.

example 1
It became an intimate mixture of

Polyvinyl chloride 10 parts

Diethylhexyl phthalate 6 parts

Toluene part

Trichlorethylene 3.4 parts

and the polyethylene terephthalate strip cord dipped into this mixture until 7% of the mixture, based on the cord weight, remained on the cord. The excess of the mixture was removed and the cord treated in this way was heated ^{to 120 ° C. under tension for 90 seconds.}

A coating of an aqueous dispersion of butadiene - vinylpyridine - styrene - terpolymer - latex and resorcinol / formaldehyde resin dispersion was then applied to the cord and ^{dried at 150 °} C. for 20 seconds. The cord was then embedded 9.5 mm deep in a polychloroprene mixture and ^{vulcanized under pressure at 150 °} C. in a mold for 15 to 20 minutes.

30th

35

40 static tests using the "H" adhesion method at room temperature showed a strength of the connection above the strength of the cord, which broke at 13.6 kg.

A cord treated only with the second treatment bath (rubber latex and resorcinol resin), the Embedded 9.5 mm deep in rubber and vulcanized as above gave a strength of the Connection of only 5.9 kg in the above test.

Example 2

A solution was made from
Vinyl chloride-vinyl acetate copolymer (containing approx

90% vinyl chloride) 5 parts

Cyclohexanone 45 parts

Diethyl hexyl phthalate 1.5 parts

The tire cord was immersed in this solution and treated further as in Example 1. The strength the compound was 9.1 kg.

However, when the heating time of the first coat was increased to 4 minutes, the strength was the connection larger than that of the cord, which broke at 13.6 kg.

Claims (1)

Claim: Process for firmly bonding polyterephthalic acid ester fibers with natural or synthetic rubber by impregnating the fibers with aqueous dispersions, the resorcinol-formaldehyde resins and vinylpyridine copolymers, embedding the dried fibers in a vulcanizable rubber mixture and Vulcanizing the rubber reinforced in this way, characterized in that before the Treatment with the aqueous rubber-resin dispersion, a treatment with a paste or Dispersion of polyvinyl chloride or copolymers of vinyl chloride and vinyl acetate or Vinylidene chloride is made. 45 Publications considered:
German Patent Nos. 894 235, 907 456;
U.S. Patent Nos. 2,561,215, 2,652,353;
The Rubber and Plastics Age, 37, 394-397 (1956). 709 719/445 1. € 8 © Bundesdruckerei Berlin