JPS61225239A - Thermoplastic rubber composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which does not require vulcanization and has excellent high-temperature creep characteristics and weather resistance, consisting of a carboxyl group-contg. chloride resin, a mono- or bivalent metallic compd. and a plasticizer. CONSTITUTION:0.1-3mol equivalents (based on the quantity of carboxyl group in component B) of a mono- or bivalent metallic compd. (e.g. zinc octylate) and 20-300pts.wt. (per 100pts.wt. component B) plasticizer (e.g. di-2-ethylhexyl phthalate) are blended with a mixture of a carboxyl group-contg. epihalohydrin rubber (A) being a toluene-insoluble gel content of 10-98wt% and a carboxyl group content of 0.05-20wt% and a carboxyl group-contg. vinyl chloride resin (B) having a carboxyl group content of 0.05-20wt% and an average degree of polymn. of 500-5,000 in a weight ratio of 0.5:9.5-9:1.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a thermoplastic rubber composition, and more particularly, to a thermoplastic rubber composition that does not require vulcanization and has excellent high-temperature creep properties and weather resistance. . .

(Prior art) Ebihalohydrin rubber has excellent oil resistance, heat resistance, weather resistance, etc., and is widely used for automobile parts and other applications due to its excellent oil resistance, but of course it must be vulcanized. .

10,000, PVC resin containing gold as a binder agent, known as soft vinyl chloride resin, has a flexible rubber-like feel.
Compared to vulcanized rubber, it has superior moldability, cost, weather resistance, colorability, etc., and is widely used. However, since it is inferior to vulcanized rubber in terms of creep properties at high temperatures, its use at high temperatures is limited. Therefore, attempts have been made to improve the creep properties by using vinyl chloride resins with a high degree of polymerization or those containing a rel content. Furthermore, a method of improving compression set (by adding crosslinked nitrile rubber to vinyl chloride resin containing a glue component) is known (JP-A-58-215442゜59-51933).
). However, even with these methods, it is difficult to improve high-temperature creep properties (particularly compression set and impact resilience) at 100° C. or higher while maintaining weather resistance.

Therefore, there is currently a strong demand for a thermoplastic rubber that can be thermoplastically processed and has high-temperature creep properties close to those of vulcanized rubber without vulcanization.

(Problems to be Solved by the Invention) In view of the above situation, the present inventors have conducted intensive research to solve the above problems, and have found that a shrimp halohydrin rubber having a glue content and a carboxyl group, a carboxyl group-containing vinyl chloride resin, By using a composition containing a valent or divalent metal compound and a plasticizer as essential components, thermoplastic processing is possible and high-temperature cream processing is possible without vulcanization.
It was discovered that the characteristics were significantly improved, and the present invention was completed.

(Means for Solving the Problems) Thus, according to the present invention, the toluene-insoluble glucose is reduced to 1
There is provided a thermoplastic rubber composition comprising a carboxyl group-containing shrimp halohydrin rubber having a weight coefficient of 0 or more, a carboxyl group-containing vinyl chloride resin, a monovalent or divalent metal compound, and a plasticizer. Ru.

The carboxyl group-containing shrimp halohydrin rubber used in the present invention is shrimp chlorohydrin, a shrimp bromohydrin homopolymer, a copolymer of shrimp chlorohydrin and shrimp bromohydrin, and a shrimp chlorohydrin/or This rubber is a rubber selected from a copolymer of shrimp bromohydrin and a monomer copolymerizable with it, into which carboxyl groups have been introduced. The copolymerizable monomers include typical VCI'i epoxides, such as ethylene oxide,
Examples include propylene oxide, isobutylene oxide, cyclopene/tene oxide, methyl shrimp chlorohydrin, allyl glycidyl ether, glycidyl methacrylate, butadiene monoxide, and styrene oxide.

Methods for introducing carboxyl groups into the above-mentioned epihalohydrin rubber include copolymerizing an epoxy compound containing ester groups in nine molecules and then hydrolyzing it, or performing an addition reaction with a carmenic acid-containing compound after producing the epihalohydrin polymer. The following methods can be mentioned.

Carboxyl group content t is 0.05 to 20% by weight.

Preferably it is 0.2 to 10 weight ratio. If it is less than 0.05, the rebound resilience at high temperatures is not necessarily sufficient, and 20
There are many cases where it is meaningless to explode the content exceeding 1JIIi, or it is not suitable due to other characteristics.

In order to make this carboxyl group-containing shrimp-halohydrin-based rubber contain an R content, it is necessary to use diglycidyl ether of glycol, polyglycidyl ether radical of polyol, etc.
Methods such as copolymerization of monomers containing a large number of epoxy groups in the molecule, such as diglycidyl ester of phosphoric acid, or generation of intermolecular crosslinks by post-treatment of ashes using oxide, etc. It is good to adopt it as appropriate.

The dull content insoluble in toluene is obtained by adding 0.2 II't of carxyl group-containing shrimp halohydrin rubber that has been water-cooled and then masticated on a roll for 10 minutes to toluene 100.
This refers to the residue that is passed through an 80-mesh wire mesh after being dissolved at a humid temperature for 4 hours. The amount of glue required is 10 weight or more, preferably 3
0 fold MtII or more. If the glue content is less than 1 olls, compression set, which is one of the high temperature creep characteristics, will not be sufficiently improved, which is not preferable. Note that the upper limit of the glue content is not particularly limited, but in consideration of workability, it is preferably 98 or less.

In addition, as the carboxyl group-containing vinyl chloride resin, (1
) Vinyl chloride, acrylic acid, methacrylic acid.

Monocals such as crotonic acid and cinnamic acid? phosphoric acids or nocalic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, monomethyl maleate, monoethyl maleate, motsuputyl maleate, monomethyl itaconate, monoethyl itaconate, motsuputyl itaconate, etc. (2) vinyl chloride and α,β-unsaturated carenoic acid esters polymerized by water decomposition, and (3) ordinary chloride. Examples include those obtained by adding a carboxylic acid-containing compound to ash after producing a vinyl polymer. The carboxyl group content in this resin is usually 0.05 to 20% by weight, preferably 0.2 to 10% by weight. If the countersunk depth is less than 0.05 m, the rebound resilience at high temperatures will not be sufficiently improved.

It is often meaningless to contain more than 20 layers of porridge, or it may be undesirable due to other characteristics. Note that the average degree of polymerization of the vinyl chloride resin is not particularly limited, but is usually SOO~
5,000.

The monovalent or divalent metal compound is Li.

Na++ K” * Cs+t Mg++* Ca++
Metal oxides, hydroxides, acetates, propionates, octylates, such as t Ba++r Zn" + Cd",
Examples include carmenates such as caprates, stearates, and naphthenates, thiocarboxylates, sulfonates, phosphates, and complex salts of the above metals with acetylacetone and the like.

These may be used alone or in combination of two or more. The addition t of the metal compound is preferably 0.1 to 3 molar equivalents relative to the amount of carboxyl groups in the vinyl chloride resin. This metal compound ionically reacts with the calgexyl group in the vinyl chloride resin to crosslink the vinyl chloride resin. It is presumed that it acts as a so-called ionic crosslinking agent.

As the plasticizer, plasticizers commonly used for soft vinyl chloride resins can be used, including phthalates such as di-2-ethylhexyl phthalate, non-n-octyl phthalate, diisodecyl phthalate, dibutyl phthalate, and sohexyl phthalate. Acid esters; linear dibasic acid esters such as nooctyl anopate and dioctyl sepacate; trimellitic acid esters and polyester polymer plasticizers;
Epo+-7 such as epoxidized soybean oil and epoxidized linseed oil
Warming agent;) Phosphate ester plasticizers such as liphenyl phosphate and tricresyl phosphate can be used alone or in combination of two or more.

The mixing ratio of carboxyl group-containing epihalohydrin rubber and carboxyl group-containing vinyl chloride resin is 0.5:9.5.
to 921, preferably 1:9 to 8:2. If the mixing ratio is smaller than 0.5:9.5, a sufficient compression set improvement effect will not be achieved, and if it exceeds 9:lt-, the melt fluidity will decrease and processing methods will be restricted, which is undesirable.

The amount of plasticizer used in the present invention is appropriately selected depending on the hardness of the target product, but when considering soft rubber-like products, it is 20 to 300 parts by weight per 100 parts by weight of the cargexyl group-containing vinyl chloride resin. is preferred.

When producing the thermoplastic rubber composition in the present invention,
Same as for general vinyl chloride resin.

Various additives such as stabilizers, lubricants, fillers, antioxidants, ultraviolet absorbers, processing aids, blowing agents, pigments, flame retardants, and impact resistance aids can be added as necessary. Further, other polymers may be mixed.

(Effect of the invention) By molding the obtained composition using ordinary vinyl chloride resin processing methods such as extrusion molding, compression molding, calendar molding, blow molding, and injection molding, molding with excellent high-temperature creep properties and weather resistance can be achieved. Goods can be obtained.

This molded product can be suitably used for automobile window seal materials, electric wire sheath materials, electrical appliances, etc., which require the same characteristics.

(Example) The present invention will be described in more detail with reference to Examples below. In addition, the departments and staff in the examples are based on an uninterrupted key system.

Example 1 Shrimp chlorohydrin y-based rubber shown in Table 1, vinyl chloride resin, magnesium acetylacetonate and 100 ml of no-2-ethylhexyl phthalate, and 4 parts of butyltin malate were kneaded for 10 minutes with a hot roll at 150°C. Got nine seats. These sheets were heat-pressed at 175° C. for 100 minutes to produce press test pieces of a predetermined thickness.

The rebound resilience of this press test piece was measured using a Dunlop tripunmeter according to BS 903 Part A8: 1963.
It was measured at 140'C and expressed as nine rebound modulus (tlI). The compression set was expressed as the compression set rate (%) after 70 hours at 100°C in 25-inch compression measured according to JIS K-6301. Weather resistance was measured using a sunshine type esarometer.

Table 1 shows the results of evaluation by observing the discoloration state of the test piece after a period of time.

Example 2 Toluene insoluble glue content: 70 or more, carboxyl fund content: 1.0
% shrimp chlorohydrin homopolymer rubber 100 parts, Cal? 100 parts of a vinyl chloride resin with a xyl group content of 1.8 and an average degree of polymerization of 2,500, 4 parts of sibutyltin malate, and 2.
Example 1 except that the metal compounds and star-enabling agents shown in the table were used.
The same experiments and evaluations were conducted. The results are shown in Table 2.

Claims (1)

[Claims] A thermoplastic rubber comprising a carboxyl group-containing epihalohydrin rubber having a toluene-insoluble gel content of 10% by weight or more, a carboxyl group-containing vinyl chloride resin, a monovalent or divalent metal compound, and a plasticizer. Composition.