JPS6257443A - Chlorosulfonated polyethylene composition - Google Patents

Abstract

PURPOSE:The titled composition, obtained by incorporating a chlorosulfonated polyethylene with a specific amount of ethylene-vinyl chloride-vinyl acetate terpolymer, having improved abrasion resistance and suitable for hoses, tubes, etc. CONSTITUTION:A chlorosulfonated polyethylene composition obtained by incorporating (A) 100pts.wt. chlorosulfonated polyethylene having 25-45wt% chlorine content and 0.9-11wt% sulfur content with (B) 10-60pts.wt. ethylene-vinyl acetate-vinyl chloride terpymer having 20-70wt%, preferably 20-60wt% ethylene-vinyl acetate copolymer content.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a chlorosulfonated polyethylene composition which has good abrasion resistance and excellent surface gloss due to crosslinking. More specifically, the present invention is directed to rubber products that can be used for rubber products that have good abrasion resistance over a long period of time and do not lose their surface gloss, such as conveyor belts, various rolls, handrails, etc. This invention relates to a sulfonated polyethylene composition.

[Prior Art] Generally, compositions obtained by vulcanizing chlorosulfonated polyethylene compositions have better oil resistance, chemical resistance, and weather resistance than vulcanizates obtained by vulcanizing diene rubber compositions. It has good properties, ozone resistance, and coloring stability.

For this reason, chlorosulfonated polyethylene compositions are applied to light-colored rubber products such as hoses, tubes, gaskets, insulated wires, cables, conveyor belts, rolls, handrails, roof inks, and the like. Among these rubber products, conveyor belts, rolls, and handrails are strongly required to maintain wear resistance and surface gloss over long periods of use. However, in chlorosulfonated polyethylene compositions, it has been difficult to simultaneously improve abrasion resistance and surface gloss.

Several methods have been proposed for improving the wear resistance of conventional chlorosulfonated polyethylene compositions. First, the mineral filler addition method is a method of blending a suitable mineral filler, such as fine particulate calcium silicate or aluminum silicate, as it is, or blending a surface-treated product thereof. However, chlorosulfonated polyethylene compositions containing fine particles of calcium silicate have the disadvantage that even if the abrasion resistance can be improved immediately after vulcanization, the abrasion resistance deteriorates over time.

Furthermore, chlorosulfonated polynyletine compositions containing finely divided calcium silicate have poor dispersibility in rubber, poor storage stability, and poor fluidity during molding. For this reason, in the method of improving wear resistance by adding mineral fillers to chlorosulfonated polyethylene compositions, the type and amount of mineral fillers to be added are extremely limited, and compositions that exhibit excellent wear resistance cannot be used. was difficult to obtain.

On the other hand, as a method for simultaneously improving wear resistance and surface gloss, lubricants such as higher fatty acids, higher fatty acid esters, glycerides, etc.
There is a method of blending low-molecular polyethylene, molybdenum disulfide, etc., but with this method, the blended lubricant diffuses and evaporates onto the rubber surface as the days of use pass, causing a gradual decline in wear resistance and surface gloss. This is a drawback.

Another method for simultaneously improving wear resistance and surface gloss is to apply a lubricating gloss coating, such as silicone paint or polyurethane paint, to the surface of vulcanized chlorosulfonated polyethylene rubber, but this method does not The adhesive force between the rubber surface and the lubricating glossy coating gradually decreases, resulting in peeling, cracking, etc., which has the disadvantage that wear resistance and surface gloss deteriorate over time of use. .

On the other hand, as a method for improving the wear resistance of chlorosulfonated polyethylene compositions, there is a method for improving the wear resistance by using a polymer blend. However, these methods have drawbacks in terms of compatibility and cross-wire workability. For example, a chlorosulfonated polyethylene composition that is a blend of phenol resin, epoxy resin, polyethylene, etc. can improve wear resistance, but due to poor compatibility, it has poor appearance and is of little practical use.

On the other hand, a chlorosulfonated polyethylene composition blended with a vinyl chloride polymer has good compatibility and can improve abrasion resistance, but has extremely poor cross-wire workability and is of little practical use. That is, the crosstalk temperature when making the chlorosulfonated polyethylene composition is 40 to 100°C,
The thermal softening temperature of vinyl chloride polymer is 120° C. or higher, making it impossible to perform uniform cross-wire work. When the kneading temperature is increased to 140 to 150°C, the chlorosulfonated polyethylene is thermally degraded, the scorch stability of the composition is worsened, and the fluidity during molding of rubber products is reduced. It causes

Ethylene-vinyl chloride copolymer is a polymer having a lower heat softening temperature than vinyl chloride polymer. Therefore, ethylene
Vinyl chloride copolymers have slightly better cross-wire workability, and can be molded at a slightly lower temperature when molding rubber products.

However, the crosstalk temperature of the chlorosulfonated polyethylene composition is as high as 120° C. or higher, which lowers the scorch stability of the kneaded dough. The resulting vulcanizate has improved abrasion resistance, modulus, and rigidity, but has the drawback of increased normal elongation at break and hardness, impairing rubber elasticity.

Styrene-butadiene copolymers with a styrene content of 85 mol% or more have a low thermal softening point and can be kneaded with chlorosulfonated polyethylene at a low temperature of 80 to 90°C, and also have good compatibility. It is. However, a problem with a chlorosulfonated polyethylene composition blended with a styrene-butadiene copolymer having a styrene content of 85 mol % or more is that the effect of improving wear resistance is small.

As a copolymer of vinyl chloride and vinyl acetate, one containing 10 to 15 mol % of vinyl acetate is generally used.

Vinyl chloride containing 10 to 15 mol% of this vinyl acetate
Vinyl acetate copolymer has a slightly high heat softening temperature, making it difficult to mix wires with chlorosulfonated polyethylene at temperatures of 110 to 140
Must be done at ℃. A chlorosulfonated polyethylene composition blended with a vinyl chloride-vinyl acetate copolymer containing 10 to 15 mol% of vinyl acetate has good compatibility, and the resulting vulcanizate has good modulus and breaking strength. However, it has the disadvantages of low elongation at break and poor compression set properties.

[Problems to be Solved by the Invention] The purpose of the present invention is to eliminate the drawbacks of the prior art described above, to have both abrasion resistance and surface gloss, and to exhibit excellent durability. An object of the present invention is to provide a chlorosulfonated polyethylene composition that can be used.

[Means for Solving the Problems] The gist of the present invention is that 10 to 60 parts by weight of an ethylene-vinyl acetate to vinyl chloride terpolymer is blended into 100 parts by weight of chlorosulfonated polyethylene. A chlorosulfonated polyethylene composition characterized by:

The chlorosulfonated polyethylene used in the present invention may be of any type that is generally used industrially, such as Hypalon #40, Hypalon #40S1, Hypalon #4085, and Hypalon #45 (all manufactured by E.I. DuPont in the United States). (product name). Note that these chlorosulfonated polyethylenes have a chlorine content of 25 to 45% by weight and a sulfur content of 0.9 to 11% by weight.

In addition, the ethylene-vinyl acetate-vinyl chloride terpolymer used in the present invention is obtained by polymerizing ethylene-vinyl acetate copolymer with vinyl chloride in graph 1, and the ethylene-vinyl acetate copolymer The content of
The content is preferably 70% by weight, more preferably 20 to 60% by weight. Examples of this type of ethylene-vinyl acetate-vinyl chloride terpolymer are Graftomer R-3, Graftomer R-5 (all trade names of Nippon Zeon Co., Ltd.), Nisso Trimer LK-30, LK-50. , LF-50 (all product names of Chisso Corporation), Graphene TR-21
0, Grafrene TR-310, Grafrene TR-510
(all are trade names of Shin-Etsu Chemical Co., Ltd.).

In the present invention, chlorosulfonated polyethylene 100
The reason why the amount of the ethylene-vinyl acetate-vinyl chloride terpolymer is limited to 10 to 60 parts by weight is because if it is less than 10 parts by weight, no improvement in wear resistance can be expected. This is because if it exceeds 60% by weight, the permanent deformation becomes too large and the physical properties become plastic-like.

In addition, in the present invention, a filler, a softener, a lubricant, a vulcanizing agent, an acid acceptor, a crosslinking aid, and a coloring agent can be appropriately blended as necessary. For example, as fillers, fine particles of calcium silicate, aluminum silicate, silane-modified clay, calcined clay, calcium carbonate, fatty acid-cation activator-treated calcium carbonate, fine particles of magnesium silicate, etc. can be blended. The amount of filler blended is not particularly limited, but chlorosulfonated polyethylene 100
It is appropriate to mix 30 to 100 parts by weight of the filler.

In addition, any softening agent may be used as long as it is compatible with chlorosulfonated polyethylene and does not inhibit color tone, such as phthalate ester plasticizer, sebacate ester plasticizer, chlorinated paraffin, epoxy type Plasticizers and the like are preferred.

The amount of these lubricants to be blended may be determined depending on the hardness of the vulcanizate, but in consideration of surface gloss and abrasion resistance, 5 to 30 parts by weight per 100 parts by weight of chlorosulfonated polyethylene is appropriate.

The lubricant may be one that prevents adhesion to the metal surface of the rubber processing machine and has good mold release properties, such as fatty acids, fatty acid esters, fatty acid amides, glycerin, esters of glycerin, sorbitan fatty acid esters, low-molecular-weight polyethylene, and microcrystalline. Examples include wax, polyethylene glycol, and cis-4 polybutadiene. Among these lubricants, particularly preferred are fatty acids, low-molecular polyethylene, sorbin fatty acid esters, polyethylene glycol, and the like. It is more appropriate to use two or more of these lubricants in combination than to use them alone. This is because the kneading temperature when making a chlorosulfonated polyethylene composition that is a blend of nyretin-vinyl acetate-vinyl chloride terpolymer is slightly higher than the kneading temperature of a single chlorosulfonated polyethylene composition, and can be used over a wide temperature range. This is to effectively exhibit anti-adhesive properties. The amount of the lubricant to be added is not particularly limited, but is preferably 2 to 10 parts by weight per 100 parts by weight of chlorosulfonated polyethylene.
The weight part is appropriate. This is because if the amount is less than 2 parts by weight, the anti-adhesive effect is small, and if it is more than 10 parts by weight, the moldability, especially the knitting property, is reduced.

As a crosslinking method for the chlorosulfonated polyethylene composition of the present invention, conventional sulfur crosslinking, peroxide crosslinking, etc. can be used. As vulcanizing agents and vulcanization accelerators,
Any material that is practically used for rubber may be used, and the amount to be blended is not particularly limited.

As the acid acceptor or crosslinking aid, magnesium oxide, red lead, litharge, etc. are suitable, and magnesium oxide, which has good color tone adjustment, is particularly suitable.

Any coloring agent can be used depending on the hue. For example, inorganic pigments and organic dyes such as titanium dioxide (rutile type), phthalocyanine blue, phthalocyanine green, watching red, benzidine yellow, carbon black, and valve plate can be used.

For producing products of the chlorosulfonated polyethylene composition of the present invention, conventional rubber kneading machines such as Banbury mixers, internal mixers, kneader blenders, open rolls, etc. can be used.

Among these mixers, a closed mixer such as a Banbury mixer is more suitable than an open mixer such as an open roll mixer. This is because ethylene has a slightly higher heat softening temperature.
This is necessary because the vinyl acetate-vinyl chloride terpolymer is uniformly heated and fluidized while being dispersed and kneaded in the chlorosulfonated polyethylene.

[Function] The effect of the chlorosulfonated polyethylene composition of the present invention is that the ethylene-vinyl acetate-vinyl chloride terpolymer can be absorbed by 10 to 60% by weight, which was completely unexpected with conventional chlorosulfonated polyethylene compositions. It is necessary to simultaneously and effectively improve abrasion resistance and surface glossiness by incorporating a certain amount of the above. That is, when a chlorosulfonated polyethylene composition containing 10 to 100 parts by weight of an ethylene-vinyl acetate to vinyl chloride terpolymer is molded and then vulcanized, it exhibits durability that was not expected with these materials alone. It exhibits abrasion resistance and surface gloss.

[Example] 7 Examples of the chlorosulfonated polyethylene composition of the present invention will be described below along with comparative examples. In addition, the numerical values described here indicate parts by weight, and the physical property values of each test are in accordance with J Is-
6301. In addition, the surface gloss was evaluated using a gloss meter (GM-24 manufactured by Murakami Color Research Co., Ltd.).
(type).

Example 1 A mixture was prepared by blending 15 parts by weight of Graph 1-mer R-5 and its compounding agents as shown in Table 1 with respect to 100 parts by weight of chlorosulfonated polyethylene. A chlorosulfonated polyethylene composition was obtained by kneading with a closed 10-inch roll at a roll temperature of 13f110''C.

Example 2 A chlorosulfonated polyethylene composition containing 25 grafts of graftomer R5 was obtained in the same manner as in Example 1.

Example 3 In the same manner as in Example 1, a chlorosulfonated polyethylene composition containing 55 parts by weight of graftomer R-5 was obtained.

Example 4 In the same manner as in Example 1, 1 q of a chlorosulfonated polyethylene composition containing 15 parts by weight of graftomer R-3 was prepared.

Example 5 A chlorosulfonated polyethylene composition containing 25 parts by weight of graftomer R-3 was obtained in the same manner as in Example 1.

Comparative Example 1 A mixture containing no polymer was prepared as in Comparative Example 1 in Table 1, and then heated at a temperature of 50°C using a closed inch roll.
A chlorosulfonated polyethylene composition obtained by kneading with "C" was obtained.

Comparative Example 2 A chlorosulfonated polyethylene composition containing 5 parts by weight of Graph 1 to Mer R-5 was obtained in the same manner as in Example 1.

Comparative Example 3 A chlorosulfonated polyethylene composition containing 65 parts by weight of graftomer R-5 was obtained in the same manner as in Example 1.

Comparative Example 4 Evaflex 527 of ethylene-vinyl acetate copolymer
-4 (trade name of Mitsui Fluorochemical Co., Ltd.) and other ingredients as shown in Table 1 to make a mixture, and then roll the mixture with a closed 10-inch roll. A chlorosulfonated polyethylene composition was obtained by kneading at a temperature of 90'C.

Comparative Example 5 A chlorosulfonated polyethylene composition containing 25 parts by weight of EVAFLEX-550 (trade name of Mitsui Fluorochemical Co., Ltd.) as an ethylene-vinyl acetate copolymer was obtained in the same manner as in Comparative Example 1. .

Comparative Example 6 In the same manner as in Example 1, a chlorosulfonated polyethylene composition was obtained by blending 25 parts and 25 parts of EV-U (trade name of Nippon Zeon Co., Ltd.) as an ethylene-vinyl chloride copolymer.

Comparative Example 7 In the same manner as in Example], 25% of vinyl chloride-vinyl acetate copolymer 1505 (trade name of Japan Synthetic Rubber Co., Ltd.) was used.
A chlorosulfonated polyethylene composition containing the following parts by weight was obtained.

Comparative Example 8 □ 25 parts by weight of JSR-0061 (trade name of Japan Synthetic Rubber Co., Ltd.) was blended as a styrene-butadiene copolymer with high styrene content in the same manner as in Example 1 except that the roll temperature was 90°C. A chlorosulfonated polyethylene composition was obtained.

The thus obtained chlorosulfonated polyethylene compositions of Examples and Comparative Examples were molded into rubber plates, and then press vulcanized to create vulcanized rubber plates, and the vulcanized rubber plates were subjected to rubber property tests. Table 2 shows the results of these characteristic tests.

As can be seen from Table 2, the vulcanized rubbers obtained from Examples 1 to 5 using the chlorosulfonated polyethylene compositions of the present invention have excellent abrasion resistance and surface gloss, and are also resistant to normal physical properties and heat aging resistance. The compression set characteristics are also well balanced.

On the other hand, the vulcanized rubbers obtained from the chlorosulfonated polyethylene compositions of Comparative Examples 1 to 8 have the disadvantage that these properties cannot be maintained in a well-balanced manner.

That is, Comparative Examples 1 and 2 have poor abrasion resistance and surface gloss, while Comparative Example 3 has excellent surface gloss, but has a disadvantage of having a large compression set. The disadvantage of Comparative Examples 4 and 5 is that the wear resistance is extremely poor. In Comparative Example 6, the hardness and modulus are too large, and the elongation at break is too small. This is the one with the lowest elongation at break and heat aging resistance compared to Comparative Example 7. Comparative Example 8 has poor abrasion resistance.

[Effects of the Invention] As detailed above, when the chlorosulfonated polyethylene composition of the present invention is applied to hoses, tubes, rolls, handrails, and roof inks, it has excellent abrasion resistance and surface properties without impairing other properties. It can exhibit glossiness at the same time and is industrially useful.

Claims (1)

[Claims] (1) A chlorosulfonated polyethylene composition comprising 10 to 60 parts by weight of an ethylene-vinyl chloride-vinyl acetate terpolymer mixed with 100 parts by weight of chlorosulfonated polyethylene.