JPH0959391A - Crosslinking assistant for polymer - Google Patents

Abstract

(57) [Problem] To provide a cross-linking aid for polymers having excellent heat stability so as not to volatilize during high-temperature processing. A crosslinking assistant for a polymer comprising a diallyl isocyanurate salt. Target polymers include ethylene-propylene-diene rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, hydrogenated acrylonitrile-butadiene rubber, fluororubber, ethylene-vinyl acetate rubber, polyethylene, polypropylene, fluororesin, vinyl chloride resin, and polystyrene. One selected from the group is preferred, but a fluororesin that is crosslinked at a high temperature is most preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinking aid for polymers, and more particularly, to a crosslinking aid for polymers having excellent heat stability during processing.

[0002]

2. Description of the Related Art A crosslinker having an allyl group increases the crosslink density of a polymer by being used in combination with a crosslinker or by irradiation with an actinic ray such as an electron beam. Improve weather resistance, electrical properties, etc. For example, triallyl isocyanurate improves the heat resistance of various polymers due to the excellent heat resistance of the triazine ring serving as its skeleton, and the unique structure and properties of mechanical properties and weather resistance of various polymers. , Hydrolysis resistance and the like are also improved.

[0003]

By the way, in the case of a polymer which undergoes a crosslinking treatment at a relatively high temperature, such as a fluororesin, the added crosslinking aid often does not function effectively due to the scattering loss of the crosslinking aid. . The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a crosslinking assistant for polymers having excellent heat stability so as not to volatilize during high-temperature processing.

[0004]

That is, the gist of the present invention resides in a cross-linking aid for polymers, which comprises a diallyl isocyanurate salt.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, the diallyl isocyanurate salt suitably used as a crosslinking aid is represented by the following general formula.

[0006]

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In the above general formula, M represents a monovalent metal, for example, Li, Na, K and the like. Preferred monovalent metals are N
a.

In the present invention, the diallyl isocyanurate salt may be a salt in which two or more diallyl isocyanurate units are bonded to a divalent or higher valent metal. For example, as divalent metals, Be, Mg, Ca, Sr, B
a, Zn, Cd and the like. Both diallyl isocyanurate salts are powders. The most preferred diallyl isocyanurate salt is the diallyl isocyanurate Ca
Salt or Zn salt.

The monovalent metal salt of diallyl isocyanurate can be produced, for example, by a neutralization reaction of diallyl isocyanurate with an aqueous solution of a metal hydroxide, and the divalent metal salt of diallyl isocyanurate can be produced, for example, by monovalent metal salt. Can be easily obtained by a metathesis reaction between a metal salt of the above and a divalent metal chloride.

[0010] The polymer to which the crosslinking aid of the present invention is applied is not particularly limited, but preferred polymers are ethylene-propylene-diene rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, hydrogenated acrylonitrile-butadiene rubber. , Fluoro rubber, ethylene-
It is one selected from the group consisting of vinyl acetate rubber, polyethylene, polypropylene, fluororesin, vinyl chloride resin, and polystyrene. These polymers are vulcanized and cured by the addition of organic peroxides or by irradiation with active rays such as electron beams.
Crosslinking is possible.

The crosslinking aid comprising the diallyl isocyanurate salt of the present invention usually acts as a bifunctional or tetrafunctional crosslinking aid based on two or four allyl groups to improve the physical properties of the polymer. The crosslinking aid of the present invention may be used in combination with a suitable crosslinking agent such as an organic peroxide or an amine, or in combination with an actinic ray treatment such as an electron beam, according to a known method, to increase the crosslinking density of the polymer. And improve the heat resistance, weather resistance, electrical properties, etc. of rubber and resin.

The amount of the crosslinking aid used in the present invention can be selected from a wide range depending on the type of the polymer and the desired improvement in physical properties, but is usually 0.1 to 20% by weight, preferably 1 to 20% by weight, based on the polymer. It is selected from the range of 10% by weight. The mixing treatment of the crosslinking aid of the present invention and the polymer is performed using a twin screw extruder, a Banbury mixer, a Brabender, or the like, and the treatment temperature is a temperature higher than the melting point of the polymer.

In the above-mentioned mixing treatment, known additives can be appropriately used. Such additives typically include antioxidants consisting of alkylated phenols such as "Irganox 1010", "Irganox 1015", "Irganox 1076". Other examples include a flame retardant and a pigment. ADVANTAGE OF THE INVENTION According to the crosslinking aid of this invention, the effective crosslinking reaction can be performed with respect to the polymer in which the processing temperature was conventionally too high and the crosslinking aid was not used effectively.

As the organic peroxide, for example, 2,5-
Hydroperoxides such as dihydroxy peroxide and dialkylallyl peroxides such as dicumyl peroxide are included. In the case of a fluororesin such as a copolymer of ethylene and tetrafluoroethylene, the resin is crosslinked by actinic radiation treatment. The irradiation dose is generally about 50 Mrad or less in order to avoid deterioration of the ponomer due to excessive irradiation. Although the specific dose depends on the desired degree of crosslinking, it is usually 2 to 40 Mrad, preferably 3 to 20 Mrad.
It is selected from the range of M rads. Irradiation with actinic radiation is generally performed at around room temperature, but may be performed at a higher temperature.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Examples 1 to 3 and Comparative Example 1 (1) ETFE having a melting point of 270 ° C. (fluororesin comprising a hard segment having ethylene, tetrafluoroethylene and hexafluoropropylene units), (2) TP
E ("Daiel T-530" manufactured by Daikin Industries, Ltd .: thermoplastic elastomer composed of soft segments having vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene units), (3) diallyl isocyanurate salt, (4) antioxidant ("Irganox 100" manufactured by Ciba Geigy Co., Ltd.) was used and mixed at 300 ° C. by a 1.5-inch single screw extruder as the charged composition shown in Table 1. Each of the obtained resin compositions was 25
It was molded into a slab of a mill, irradiated with an electron beam at a total dose of 5 Mrad, subjected to a crosslinking treatment, and then subjected to physical property measurement. The results are shown in Tables 1 and 2.

The tensile strength and scant modulus (flexibility) were measured for each sample which had not been irradiated with an electron beam, irradiated with an electron beam, or annealed after irradiation with an electron beam. E30 (30
% Elongation required to achieve% elongation) and M
100 (force required to achieve 100% elongation / initial cross-sectional area) was applied to each sample that had been subjected to electron beam irradiation and annealing treatment after electron beam irradiation. The solvent resistance, thermal aging property and low-temperature impact brittleness temperature test were performed only on the electron beam irradiated sample.

The E30 and M100 measurements were made by The Elec Manufacture (R, M, Black) by The Elec.
The method was performed according to the static modulus method of T.M.

Tensile strength and elongation measurements, including those performed after thermal aging and solvent immersion, are based on ASTM D
414, and the measurement of scant modulus is:
The measurement of the low-temperature impact brittle temperature test was performed according to ASTM D746.

In the solvent resistance test, a test sample (having a thickness of 0.02
5 inches, width 1/8 inch) is immersed in each liquid, ie, "Skydrol 5"
00 (manufactured by Monsanto) at room temperature for 24 hours.
2 "at room temperature for 4 hours, and then measuring the tensile strength and elongation. "Skydroll (S
kidrol 500 "is a phosphate ester pressurized medium, and" DS-2 "is diethylene triamine (70
%), Ethylene glycol monoester (28%) and N
A mixture with aOH (2%).

In the heat aging test, a test sample (having a thickness of 0.
(025 inch, 1/8 inch width) was left in a furnace controlled at 250 ° C. for 1 week and 2 weeks, respectively, and then the tensile strength (T) and elongation (E) were measured.

[0022]

Table 1 Example Comparative Example 1 2 3 1 <Formulation Composition> ETFE 77 77 77 77 TPE 20 20 20 20 Antioxidant 0.9 0.9 0.9 0.9 diallyl isocyanurate Ca salt 3 − − − diallyl isocyanurate Zn salt − 3 − − diallyl isocyanurate Al salt − − 3 − diallyl isocyanurate − − − 3 <Tensile strength (Kg / cm ² )> No electron beam irradiation 340 350 345 272 Electron beam irradiation 336 390 360 260 Electron beam irradiation / annealing 343 382 358 265 <Elongation (%)> No electron beam irradiation 315 320 320 400 Electron beam irradiation 240 250 245 260 Electron beam irradiation / annealing 220 225 225 220 <2% scan tomosillus (Kg / cm ² )> No electron beam irradiation 4126 4200 4188 4100 Electron beam irradiation 5381 5521 5400 5110 Electron beam irradiation / Annealed 4200 4300 4250 4050 ───────────── ──────────────────────

[0023]

[Table 2] Example Comparative Example 1 2 3 1 <E30 (300 ° C) (Kg / cm ² )> electron beam irradiation 8.3 9 8.8 6 electron beam irradiation / annealing 11.0 12 11.5 10 <E100 (300 ° C) (Kg / cm ² )> electron beam irradiation 5.0 5.5 5.5 3 electron beam irradiation / Annealed 6.9 6.5 6.6 5 <Solvent resistance (Kg / cm ² )> T / E DS-2 (24 hours / room temperature) 395/21 400/25 401/24 300/35 SkyTroll 500 (24 hours / room temperature) 348/16 360/17 355/20 277/30 <Thermal aging (Kg / cm ² )> T / E 1 week (250 ° C) 294 / 14.5 311/15 300/15 255/30 2 weeks (250 ° C) 276/12 301/14 288/14 250/28 <Low temperature impact brittle temperature> (All pass at -65 ° C) ──────────────────────── ────────────

[0024]

According to the present invention described above, a cross-linking aid for polymers having excellent thermal stability so as not to volatilize during high-temperature processing is provided.
It is suitable for a fluororesin which is crosslinked at a high temperature.

Claims (2)

[Claims] 1. A cross-linking aid for polymers comprising a diallyl isocyanurate salt. 2. The polymer is ethylene-propylene-diene rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, hydrogenated acrylonitrile-butadiene rubber, fluorine rubber, ethylene-vinyl acetate rubber, polyethylene, polypropylene, fluorine resin, vinyl chloride resin. The crosslinking aid according to claim 1, wherein the crosslinking aid is one selected from the group consisting of polystyrene and polystyrene.