JPS5817030B2 - How to set up ethylene propylene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adhering ethylene propylene copolymer rubber to fibers, particularly for adhering peroxide vulcanizable ethylene propylene copolymer rubber to fibers.

This is related to how to

In recent years, the use of rubber products such as conveyor belts, belts, tires, and braided hoses has become increasingly demanding, and the need for heat resistance in particular has increased significantly. Alternatively, butyl rubber and the like had become increasingly difficult to withstand, but with the recent appearance of ethylene propylene copolymer rubber, it has become possible to develop rubber products that can withstand use at high temperatures.

However, this ethylene propylene copolymer rubber has no or very few unsaturated bonds in its molecules, so in sulfur vulcanization systems it must be combined with a strong accelerator or it cannot be cured. An oxide vulcanization method must be used.

Among these, peroxide-based sulfuric coatings are particularly expected to have the highest heat resistance.

However, the various rubber products mentioned above are composites combined with fibers and reinforced with organic fiber materials, such as woven fabrics such as nylon, vinylon, rayon, and polyester.
．． With the combination of RFL liquid, which is a conventional adhesive for these fibers of ethylene propylene copolymer rubber, it was not possible to obtain sufficient adhesive strength due to the vulcanization mechanism and adhesion mechanism.

The present invention focuses on and attempts to solve the problems in conventional vulcanization, and aims to improve the adhesive strength between ethylene propylene copolymer rubber and fibers. In bonding copolymer rubber and fibers, acrylamide and formalin are reacted in the presence of an alkali, and the solution is added to resorcinol, formalin, latex, or a solution consisting of resorcinol and latex, and after aging, the fibers are bonded to this solution. The rubber is treated with peroxide and then vulcanized with peroxide in close contact with the rubber.

This will be explained in more detail below.

First, the adhesive texture agent in the present invention is prepared by treating 1 mole of acrylamide with 0.3 to 2.5 moles of formalin as a catalyst in the presence of a 0.005 to 0.08 normal alkali.
The reaction is carried out at 0 to 100°C for 1 to 7 days to obtain a liquid containing N-methylol acrylamide, and this liquid is mixed with the solid content (formalin (including 40 to 400 parts by weight) per 100 parts by weight and ripened.

In addition, when making a liquid containing N-methylol acrylamide,
If too much formalin is added, formalin can be added to a liquid consisting of unsaturated resorcinol and latex.

In order to generate N-methylol acrylamide, it is necessary to make the reaction system alkaline, and if it is acidic, it will gel.

It is generally known that in alkaline conditions, acrylamide reacts with formalin to produce N-methylolacrylamide.

Further, examples of the alkali used in the present invention include sodium hydroxide and potassium hydroxide.

Furthermore, the latex contains natural rubber, styrene-butadiene copolymer, styrene-butadiene vinylpyridine copolymer,
Carboxylated acryloni l-IJ butadiene copolymer, chloroprene polymer, etc.

Ru.

Next, using the adhesive treatment agent obtained as described above, after immersing the fibers in this, the adhesive agent is usually heated for 5 to 50 minutes at 130 to 180°C.
The material was heat-textured for 15 minutes and then packed with unvulcanized ethylene propylene copolymer rubber.

and peroxide vulcanization.

The fibers to which the present invention is applied include all forms of fibers such as cotton, rayon, vinylon, nylon, and polyester, cords, woven fabrics, nonwoven fabrics, sheets, and felts.

Furthermore, ethylene propylene copolymer rubber can be peroxide vulcanized, and ethylene propylene copolymer rubber can be cured with peroxide.
As a component, for example, 1,4-pencdiene, 2-methyl-
1,4-pentadiene, 1°5-hexadiene, 2-methyl-1,5-hex.

diene, dicyclopentadiene, 2-methylene-2,5
- A binary copolymer rubber having a non-conjugated double bond such as norbornene, and these rubbers are used alone or as a blend in any proportion.

Also, the peroxide is dicumyl peroxide, α,
α'-bis(tert-peroxy)paradiisopropylbenzene, 2,5-diethyl-2,5-di(cuc-butylperoxy)hexane, 2,5-dimethyl-2
,5-di(tert-butylperoxy)hexyne-3
, n-butyl-4,4-hysteralifthyloxypervalerate, etc. These are used alone, but in many cases they are used diluted with an inorganic filler such as calcium carbonate.

The adhesion mechanism in the present invention is the N of the adhesive treatment agent.
The methylol group of methylol acrylamide directly reacts with the amide group or hydroxyl group of the fiber, or forms a hydrogen bond and adheres to it, or the methylol group of N-methylol acrylamide reacts with sorcin, formalin, and becomes methylolated resorcin. It is thought that a dehydration reaction occurs with the methylol group of the resorcinol to form an ether bond, and the methylol group of the free resorcinol forms a bond with the amide group or hydroxyl group of the fiber or forms an adhesion through hydrogen bonding.

In this way, the fibers and the adhesive texture agent are combined, and then when the ethylene propylene copolymer rubber is peroxide vulcanized, hydrogen from the rubber is extracted by the peroxide radicals and carbon radicals (hereinafter referred to as rubber radicals) are generated. arise.

Then, the lever radicals combine to crosslink the rubber, and furthermore, on the fiber surface, the unsaturated bonds of N-methylol acrylamide and the rubber radicals react to form a bond, and the ethylene propylene copolymer rubber composition and the fiber become stronger. Glue.

・The method of producing an adhesive reaction such as an upward slope is completely new and has far superior adhesive strength than the conventional release liquids of resorcinol, formalin, and latex. Experimental results have confirmed that rubber-to-rubber destruction occurs even in a peeled state.

This improvement in adhesive strength achieved by the present invention not only enables the various rubber products mentioned above to be used at higher temperatures, but also allows them to withstand severe dynamic usage conditions, which is an extremely remarkable effect. .

Note that the acrylamide used also acts as a crosslinking aid in the peroxide vulcanization of ethylene propylene copolymer rubber, so if there is a large amount of acrylamide compared to formalin, the acrylamide in the reaction residue i acts as a crosslinking aid, Effectively works to improve rubber physical properties.

Furthermore, it has been found that even when acrylamide polymerizes to form polyacrylamide during thermal texture of fibers after dipping treatment, it can be expected to be sufficiently effective as a crosslinking aid.

When there is more formalin than acrylamide, the remaining formalin from the reaction is used to methylolize resorcinol.

Next, specific embodiments of the method of the present invention will be explained with reference to the examples described below, but it goes without saying that the present invention is not limited to these five examples.

Example 1 As shown in Table 1, acrylamide and 37% formalin were reacted in the presence of sodium hydroxide at 50°C for 3 days to obtain a mixed solution of N-methylolacrylamide (IX2).

* 0.01 normal, ** 0.1 normal k The obtained mixture (1) is colorless and transparent, but the liquid (2)
produced a white precipitate.

Next, the mixture (1) was taken at 20C, e, and 100CC of acetone was added thereto, and when it was left at -20C for 1 day, a white powder was precipitated.

When this powder is examined by infrared absorption spectrum, it shows the ether bond (1100) as shown in Figure 2.

1 1140CrrL) can be seen.

When this is considered in comparison with the infrared absorption spectrum of N-methylolacrylamide in FIG. 1, it can be recognized that the liquid is a mixture of N-methylolacrylamide and N-methylol acrylamide in which the methylol groups are dehydrated and condensed.

Next, an RF liquid was prepared from the composition shown in Table 2, and further aged at 50°C for 13 days from the composition shown in Table 3 to obtain an adhesive treatment agent.

50% A°Rubber - Rubber rupture, B=(Z, Knee, 5o) Next, the nylon canvas was immersed in Table 3 texture liquid (IX2X3) and heated at 150°C for 10 minutes. This was then vulcanized and bonded by heating at 150° C. for 160 minutes in close contact with the compounded rubber shown in Table 4.

The adhesive force measurement was carried out according to JIS K6301, and the obtained results are shown in Table 3 above.

Example 2 Add excess formalin as shown in Table 5
A mixed solution (3) of N-methylolacrylamide was obtained in the same manner as above.

The obtained liquid mixture (3) was colorless and transparent.

Next, an adhesive treatment agent was obtained from the composition shown in Table 6 by aging at 50° C. for 3 days.

A nylon canvas was immersed in this adhesive treatment agent and treated in the same manner as in Example 1, and was vulcanized and bonded to the compounded rubber shown in Table 4.

The results of the adhesive strength are also shown in Table 6.

Comparative Example 1 In contrast to the above implementations 1 and 2, as shown in Table 7,
As in the example, the composition does not contain acrylamide.
After aging at 0° C. for 3 days, another adhesive treatment agent was applied.

Using this treatment agent, the adhesive strength was measured in the same manner as in the examples, and the results were as shown in Table 7.

From the results of the above Examples and Comparative Examples, the adhesive treatment agent of the present invention has a remarkable effect on adhesion between peroxide vulcanized rubber of ethylene propylene copolymer rubber and fibers. It can be seen that this adhesion method is superior to that of the conventional method.

[Brief explanation of drawings]

FIG. 1 is a graph showing the infrared absorption spectrum of N-methylolacrylamide, and FIG. 2 is a graph showing the infrared absorption spectrum of the mixture (1) in Table 1.

Claims (1)

[Claims] 1. In adhesion of ethylene propylene copolymer rubber and fibers, acrylamide and formalin are reacted in the presence of alkaline and potassium, and the resulting liquid is mixed with resorcin, formalin,
Latex or resorcinol, an ethylene fiber characterized in that after being aged in a liquid made of latex, the fibers are treated with this liquid, and then the fibers are brought into close contact with the rubber and vulcanized with peroxide. A method for adhering propylene copolymer rubber and fibers.