JPS6310732B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides an advantageous composite of fibers and a rubber composition comprising an ethylene-propylene-nonconjugated diene terpolymer (hereinafter referred to as EPDM) or an ethylene-propylene copolymer (hereinafter referred to as EPM). Regarding the method. Conventionally, the above rubber compositions, namely EPDM or
As a method of bonding and compositing EPN compound and fibers, resorcinol-formalin-latex (hereinafter referred to as RFL) dip treatment (the latex used is vinylpyridine latex (hereinafter referred to as Vp latex) and/or or styrene-butadiene latex (hereinafter referred to as
Attempts have been made to bond EPDM compound containing sulfur to SBR latex (called SBR latex). However, in this case, there are drawbacks such as insufficient adhesion and a large decrease in adhesion after heat aging. Furthermore, in order to improve heat resistance, it has been proposed to use EPDM or EPM compounds that use organic peroxides as crosslinking agents, but even with these compounds it is difficult to obtain sufficient adhesion to fibers. Therefore, this compound was mixed with toluene, n-
Attempts have also been made to dissolve the fibers in an organic solvent such as hexane and treat the fibers with a cement dip. However, in this case, since an organic solvent is used, there are various problems in terms of safety and hygiene, facilities, etc. The present invention was made in order to solve these problems, and an object of the present invention is to provide a composite method that can sufficiently bond a rubber composition made of EPDM or EPM to fibers. do. Therefore, the method of compounding the rubber composition and fibers of the present invention contains 1/300 to 1/10 mole of dialkyl peroxide based on 100 parts by weight of the polymer,
And the following formula, (In the formula, n=1 to 4, R ₁ and R ₂ are H or CH ₃ )
Polymer di(meth)acrylates with
Containing 1/300 to 1/5 mole per 100 parts by weight,
A rubber composition made of EPDM or EPM is treated with resorcinol-formalin (hereinafter referred to as RF) or resorcinol-formalin-
It is characterized by vulcanization bonding with fibers treated with chloroprene latex (hereinafter referred to as RF-CR latex). Further, the rubber-fiber composite obtained by the present invention has excellent heat resistance, and is therefore suitable for applications requiring heat resistance, such as heat-resistant belts and heat-resistant air springs. Note that the dip treatment refers to immersing the fibers in a dip liquid such as resorcinol-formalin or resorcinol-formalin-latex, and then subjecting the fibers to a high-temperature heat treatment. Hereinafter, the configuration of the present invention will be explained in detail. The EPDM or EPM used in the present invention ranges from EPM with an iodine value of zero to iodine value of 29 or more.
EPDM can also be used. Also, EPDM or
A diene polymer or the like may be blended with EPM. The dialkyl peroxides may be dialkyl peroxides as long as they have a decomposition temperature (temperature at which the half-life is 10 hours) of 90°C or higher, and desirably one with a decomposition temperature of 117°C or higher to obtain better adhesion. For example, tertiary butyl cumyl peroxide, tertiary butyl cumyl peroxide,
dicumyl peroxide, 2,5-dimethyl-
2,5-ditertyabutylperoxyhexane, 2,5-dimethyl-2,5-ditertyabutylperoxyhexane-3,1,3-bister
Examples include sheabutylperoxyperoxyisopropylbenzene. The amount of peroxide blended is 1/300 mol to 100 parts by weight of the polymer.
1/10 mole, preferably 1/150 mole to
It is 1/25 mole. If it is less than 1/300 mol, the vulcanization adhesion described below will not be performed sufficiently;
If it exceeds 10 moles, heat resistance may be impaired or scorch may occur easily. Further, the di(meth)acrylates used in the present invention have the following general formula. (In the formula, n = 1 to 4, R ₁ and R ₂ are H or CH ₃ ) The above di(meth)acrylates are, for example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol Di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate. , 1,6-hexanediol di(meth)acrylate, etc. The amount of di(meth)acrylates to be blended is 1/300 mol to 1/5 mol, preferably 1/200 mol to 1/10 mol, based on 100 parts by weight of the polymer.
If it is less than 1/300 mole, good adhesion cannot be obtained, while if it exceeds 1/5 mole, heat resistance will be impaired. The rubber composition in the present invention is composed of dialkyl peroxides, di(meth)acrylates, and EPDM or EPM as described above, and may optionally contain a plasticizer, reinforcing agent, anti-aging agent, etc. may contain. Furthermore, the fibers used in the present invention include synthetic fibers such as 6-nylon, 66-nylon, vinylon, and polyester, recycled fibers such as rayon, and natural fibers such as cotton. These fibers are subjected to RF dip treatment or RF-CR latex dip treatment. Note that this process may be performed by a conventional method. The treated fibers and the rubber composition described above,
In the present invention, vulcanization bonding is performed. Vulcanization in this case may also be performed by a common method. For example, after pressure molding into a desired shape using a normal processing method, vulcanization can be performed at a temperature that allows organic peroxide crosslinking (e.g., 100°C to 250°C). can be achieved. In addition, as the pressurization and heating method, in addition to a normal press, a method using steam or hot water can also be adopted. Examples and comparative examples are illustrated below. In addition,
All amounts in these examples are in parts by weight unless otherwise specified. Examples and Comparative Examples The formulations (A to I) shown in Table 1 below were kneaded using a closed mixer, and then formed into a sheet approximately 3 mm thick using an 8-inch roll. In addition, the compound (A
~D) is for comparison and formulation (E~
I) is for the present invention.

【table】

[Table] Table 2 below also shows RF dip liquid and resorcinol-formalin-latex (hereinafter referred to as
The composition of the dip liquid (referred to as RFL) is shown below.

[Table] Prepare the dip liquid shown in Table 2 and store it at room temperature.
After aging for 24 hours, 6-nylon canvas (strength 100 each)
kg/cm) and baked at 190°C for 2 minutes. The dip-treated canvas was cut to 150 mm x 100 mm, sheets of compounds A to I shown in Table 1 were placed on top, placed in a 150 mm x 100 mm x 3 mm mold, and a surface pressure of 15 kg/cm was applied using a press vulcanizer. At ²
Pressure bonding vulcanization was performed at 165°C for 30 minutes. After vulcanization, this rubber fiber composite was cut to a width of 25 mm, and the 180 degree peeling force was measured using an autograph at a peeling speed of 50 mm/sec. Table 3 below shows the case of RFL dip treatment (using CR latex).

[Table] In Table 3, RFL (using CR latex)
The adhesion to dip-treated canvas was higher than that of the SBR compound (Comparative Example 1) and the sulfur-vulcanized EPDM compound (Comparative Example 2), compared to the EPDM (or EPM) compound containing dimethacrylates and dialkyl peroxides ( Example 1~
It is clearly seen that 5) shows good adhesion and rubber adhesion both at room temperature (20°C) and when heated (150°C). Comparative Example 3 containing trimethacrylate is the same as Example 1 containing dimethacrylate.
It is clearly seen that the adhesion at room temperature (20°C) and when heated (150°C) is inferior to that of Sample 5. In Comparative Example 4, a peroxyketal peroxide with a half-life of 90°C or less is used.
It can be clearly seen that the adhesion is inferior both at room temperature (20°C) and when heated (150°C) compared to dialkyl peroxides (Examples 1 to 5) having a half-life of 90°C or more. From the comparison of Example 1, Example 4, and Example 5,
It is clear that good adhesion is exhibited even when EPDM is replaced with EPM or when blended. Further, from Examples 2 and 3, it is seen that good adhesion can be obtained even when di(meth)acrylates are blended from 1/200 mol to 1/10 mol. Table 4 below shows RFL (Vp Latex,
(SBR latex) dip processing is shown.

[Table] Table 4 shows the adhesion strength of different RFL dip-treated latexes (Vp latex, SBR latex, CR latex) and the adhesive strength after heat aging. In Comparative Example 5 (Vp latex) and Comparative Example 8 (SBR latex), which used SBR compounds, the original adhesion was good, but the rubber deteriorated due to heat aging, resulting in a large decrease in adhesive strength. In addition, sulfur-cured EPDM compounds (Comparative Example 7,
In Comparative Example 10), adhesion of Vp latex and SBR latex to RFL dip-treated canvas was poor. The combination of the peroxide vulcanized EPDM compound containing di(meth)acrylates according to the present invention and the CR latex RFL dip-treated canvas (Example 1) has good adhesion and no adhesive deterioration after heat aging. I can clearly see that there are few. However, as can be seen from Comparative Examples 7 and 10, the adhesion of Vp latex and SBR latex to RFL dip-treated canvas is completely poor. RF in Table 5 below
The case of dip processing is shown.

[Table] Table 5 shows examples using canvas treated with RF dip. Peroxide vulcanization system containing di(meth)acrylates according to the present invention.
Adhesion between EPDM and EPM compounds and canvas treated with RF dip (Example 6, Example 7)
Similar to CR latex RFL dip treated canvas (Example 1), comparative example 11 (SBR compound/
RF dip treated canvas), Comparative Example 12 (sulfur vulcanized)
EPDM compound/RF dip treated canvas),
It is clearly seen that it shows better adhesion compared to Comparative Example 13 (trimethacrylate-containing peroxide vulcanized EPDM/RF dip treated canvas). As explained above, EPDM (or
The method of combining EPM) compound and fiber is as follows:
Compared to conventional products, it exhibits extremely good adhesion and rubber adhesion both initially and after aging. Therefore, the product made by combining EPDM (or EPM) compound and fiber according to the present invention has the advantage of being a product that has extremely stable performance not only near room temperature but also in a high temperature range. It can be advantageously used for belts, heat-resistant air springs, etc.

Claims (1)

[Claims] 1. Polymer 100 of dialkyl peroxides
Contains 1/300 to 1/10 mole based on weight part, and
The following formula, (In the formula, n=1 to 4, R ₁ and R ₂ are H or CH ₃ )
Polymer di(meth)acrylates with
Containing 1/300 to 1/5 mole per 100 parts by weight,
A rubber composition comprising an ethylene-propylene-nonconjugated diene terpolymer or an ethylene-propylene copolymer, and a fiber treated with a resorcinol-formalin dip or a resorcinol-formalin-chloroprene latex dip. A method for compositing a rubber composition with fibers, which comprises vulcanizing and adhering the rubber compositions and fibers.