JPS5811532A - Rubber composition - Google Patents

Abstract

PURPOSE:A rubber composition that contains specific amounts of chloroprene modified with sulfur-free substance, a thiuram with a specific structure and a nickel salt, thus showing high adhesion as well as keeping the features of chloroprene rubber. CONSTITUTION:The objective composition comprises (A) 100pts.wt. of a rubber containing more than 50wt% chloroprene rubber modified with a sulfur-free substance, (B) 2-15, preferably 4-10pts. of a thiuram of formulaI(R<1> is alkyl, aryl; two R<1> incorporate to form a nitrogen-containing carbon ring; X is 1-6) such as tetramethylthiuram monosulfide, (C) 0.3-5pts. of at least one selected from nickel dithiocarbamate of formula II (R<2> is alkyl, aryl, cycloalkyl, two R<2> incorporate to form a nitrogen-containing ring) and nickel xanthogenate of formula III (R<3> is alkyl) and a vulcanization accelerator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chloroprene rubber composition with improved adhesion to fibers.

Chloroprene rubber has various properties superior to other diene-based rubbers. In particular, non-sulfur-modified chloroprene rubber does not contain sulfur in the polymer main chain and has excellent heat resistance, compression fatigue resistance, etc. Although it is suitable for rubber products used under harsh conditions, it has the disadvantage of poor adhesion to fibers. For this reason, rubber compositions containing various additives have been proposed, but additives generally impair the storage stability of unvulcanized rubber, and when vulcanized, they actually reduce the heat resistance, which was an advantage of chloroprene rubber. This often results in a loss of strength and compression fatigue resistance. For example, sulfur or hydrated silica is generally added to improve the adhesion of rubber, but when this method is applied to chloroprene rubber, the heat resistance and compression fatigue resistance of vulcanized rubber deteriorate significantly. Furthermore, the method of adding melamines and resorcinol significantly impairs the storage stability of unvulcanized rubber.

The present invention has been made in view of the above, and an object of the present invention is to provide a chloroprene rubber composition with excellent adhesive properties while maintaining the advantages of chloroprene rubber.

The rubber composition of the present invention (-100 parts by weight containing 500 parts by weight of non-sulfur-modified chloroprene rubber; 2 to 15 parts by weight of a thiuram compound represented by (C) a nitrogen-containing carbocyclic ring, where X is an integer of 1 to 6; From nickel dithiocarbamate represented by a cycloalkyl group or a nitrogen-containing carbon ring formed by two Ps bonding together with nitrogen, and nickel xanthogen represented by the general formula (where RB represents an alkyl group) It is characterized by containing 0.3 to 5 parts by weight of at least one selected nickel salt.

The thiuram compound used in the present invention has the general formula (
I), where Bl is preferably an alkyl group having up to 5 carbon atoms, an aryl group or an arylalkyl group having up to 8 carbon atoms, or an alkyl group having up to 10 carbon atoms formed by bonding two 11's together with nitrogen; represents a nitrogen-containing carbon ring,
represents an integer from 1 to 4. Therefore, preferred specific examples include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and the like.

Such a thiuram compound is used in an amount of 2 to 15 parts by weight, preferably 4 to 10 parts by weight, per 100 parts by weight of rubber containing 500 parts by weight of non-sulfur-modified chloroprene rubber. In general, thiuram compounds are sometimes added in small amounts as stabilizers during the production of raw material polymers in the case of sulfur-modified chloroprene rubber. Styrene
This is limited to sulfur-free vulcanization of butadiene rubber, etc., and has not been done with chloroprene rubber. The reason for this is that thiuram compounds act as vulcanization retardants for chloroprene rubber, so their use is limited to the sole purpose of preventing scorch. This not only reduces the hardness and modulus of the vulcanized rubber and deteriorates its compression properties, but also causes severe plumes.

However, in the present invention, a large amount of the thiuram compound is added to a nickel dithiocarbamate represented by the general formula (2) and/or a xanthogen nickel represented by the general formula (2) to a rubber mainly composed of chloroprene rubber. By blending 0.3 to 5 parts by weight, preferably 0.5 to 2 parts by weight per 100 parts by weight, the blooming of chloroprene rubber caused by the blending of a large amount of thiuram compound can be well prevented and the adhesive properties thereof improved. It is.

In the nickel dithiocarbamate represented by the general formula (1), Bm is preferably an alkyl group having 5 or less carbon atoms, an aryl group or arylalkyl group having 8 or less carbon atoms, or a carbon formed by bonding two R1 together with nitrogen. It represents a nitrogen-containing carbocyclic ring having a number of 10 or less, and preferable specific examples include nickel dimethyldithiocarbaonic acid, nickel dimethyldithiocarpamine, nickel di-n-butyldithiocarbamate, nickel pentamethylenedithiocarbamate, and cyclohexylethyldithiocarbamine. Examples include nickel, nickel dibenzyldithiocarbamate, nickel dibenzyldithiocarbamate, nickel ethylphenyldithiocarbamate, and the like.

Further, in the nickel xanthate represented by the general formula (2), Hs is preferably an alkyl group having 2 to 5 carbon atoms, and preferable specific examples include nickel isopropyl xanthate, nickel butyl xanthate, nickel ethyl xanthate, etc. can be mentioned.

Furthermore, in the present invention, thiourea-based agents such as thiocarboanilide, di-orthotritylthiourea, ethylenethiourea, and diethylthiourea, diphenylguanidine, diorthotolylguanidine, It is desirable to use at least one type of guanidine type such as diphenylguanidine phthalate in combination, and in this case, the appropriate amount is 1 to 5 parts per 100 parts by weight of chloroprene rubber.

In the present invention, if the rubber contains chloroprene rubber of 50% or more by weight, its adhesion can be improved without impairing the advantages of chloroprene rubber, lobrengo λ, and reinforcing agents, fillers, plasticizers, anti-aging agents, Of course, it may contain ordinary rubber compounding agents such as vulcanization aids and activators.

The chloroprene rubber composition of the present invention has good adhesion to various fibers. Examples of such fibers include organic fibers such as polyamide fibers, polyaramid fibers, polyester fibers, vinylon fibers, rayon, and cotton, and inorganic fibers such as carbon fibers, glass ta fibers, steel fibers, and ceramic fibers. , but not limited to these.

It is desirable that such fibers be subjected to a commonly used treatment for the purpose of improving adhesion to rubber. A common method for #l fiber treatment is to immerse 1RIIk in resorcinol-formalin latex (RFL liquid) and heat and dry it to form an adhesive layer evenly on the surface. On the other hand, it is widely practiced to blend stabilized isocyanate compounds or epoxy compounds, or to use RFL treatment in combination with treatment with such active compounds.

As described above, according to the present invention, by using nickel dithiocarbamate and/or nickel xanthate in combination with a large amount of thiuram compound exceeding the usual range for non-sulfur modified chloroprene rubber, it is possible to improve the quality of chloroprene rubber. It is possible to obtain an adhesive chloroprene rubber composition that suppresses blooming and has excellent storage stability while maintaining its advantages such as heat resistance and compression fatigue resistance. This makes it possible to use non-sulfur-modified chloroprene rubber even in fields that require strong adhesion to fibers, which has previously been difficult to use.

Reference Examples and Examples of the present invention are listed below, but the present invention is not limited thereto.

Reference example water 4007. An aqueous solution consisting of resorcinol 19.77 and 37% formalin 29.31 was adjusted to pH 10 with diluted soda.
K was adjusted and aged at 25°C for 6 hours. Next, this liquid 40
0y, vinylpyridine-8BB latex (J8R0650 manufactured by Japan Synthetic Rubber ■) 240g, 81B latex (J8R0691 manufactured by Nippon Synthetic Rubber ■) 12G.

and 90 g of water were mixed and aged at 25°C for 6 hours to obtain RFL.
A liquid was prepared. Nylon 6) -Y for this RFL*
(210D/3X9 configuration) was immersed and then heated to 210℃ for 2 hours.
Heat treated for minutes.

The polyester cord (1100D/3X3 configuration) was immersed in a trichlene solution of diphenylmethane diisocyanate, heat-treated at 220°C for 1 minute, and then treated with R in the same manner as above.
FL treated.

Polyaramid cord (1500D/IX5 composition) Glycerin diglycidyl ether (manufactured by Nagashio Kasei 7'+
Cole lX 313) 2.22y, 10%
12 sorter 0.28y, surfactant (Kao soap ■
Perex OTP) 0.56g and water 96.9g
1 was liquefied and heated at 240° C. for 1 minute, and then treated with RFL liquid in the same manner as above.

Glass fibers (ECjG 1501/3 configuration) were immersed in a 5% aqueous dispersion of r-aminopropyltriethoxysilane, heat treated at 200°C for 3 minutes, and then treated as above:
RFI, processed and further composed of 3 pieces ←ll0G 1503
/13).

Test Method A 12-inch test was carried out on a given chloroprene rubber composition.

(1) According to Mooney Scorch test JXB K 6300, 120” C4C 8
A Mooney scorch test was conducted using a shaped rotor.

(2) Adhesive strength A rubber composition with a predetermined thickness was molded into a 6.5-thick sheet, and seven cords were arranged on the sheet in contact with each other for each of the fiber cords obtained in the reference example, and heated to 150°C. After vulcanizing under pressure for 30 minutes at
0 ■/min, # shoe angle 18o.

It was peeled off.

(3) Using a mold specified in Heat Resistant M8'f'M D 3182-74, pressure vulcanization is performed at 150°C for 30 minutes to obtain a vulcanized sheet,
Elongation at break when aged at 120°C for 168 hours in a gear set heat aging tester according to J-K 8K 6301 ()
! +]1) was measured.

(4) Compression fatigue resistance and heat generation Rubber pressure vulcanized at 150°C for 30 minutes is A8TM D6
231, a compression fatigue test was conducted using a Gutdrich flexometer at a load of 24 pounds, a stroke of 4.4 cm, and a temperature of 100° C., and the permanent set and heat generation after 25 minutes were measured.

(5) The sample rubber used in the bloom adhesion test was left at 25° C. for one month and then visually observed.

In the following, parts indicate parts by weight.

Example 1 For 100 parts of Neoprene 'I'R 11%, 0.5 parts of stearic acid, 4 parts of magnesium oxide, 5 parts of zinc oxide,
Table 1 shows test results for chloroprene rubber compositions containing 2 parts of anti-aging agent, 5 parts of PIF Carbon 50, and 5 parts of plasticizer, and further containing the ingredients listed in Table 1.

Comparing actual test numbers X, 2, and 3 with comparative test numbers 4.5 and 7, it is clear that the rubber composition of the present invention has improved adhesion to various fibers. In addition, Comparative Example Experiment No. 6 contains sulfur and has good adhesion with fibers, but has poor heat resistance.
It is clear that they are inferior in gender.

Example 2 Stearin e o,s for 100 parts of neoprene W
About a chloroprene rubber composition containing 1 part, 4 parts of magnesium oxide, 5 parts of zinc oxide, 2 parts of anti-aging agent, 50 parts of FIiF carbon and 5 parts of plasticizer, and further contains the components shown in Table 2. The test results are shown in Table 2.

From comparative examples, when a thiuram compound is not used in combination with Carva 17fl/Nickel, a plume occurs when the thiuram compound is added by -1.5 parts per 100 parts of rubber, and becomes noticeable when it is 3 parts or more. However, the present invention shows that by using both in combination, bloom can be completely prevented. Also, when nickel xanthate is used, plume is suppressed and adhesion is improved.

Example 3 Test results for the chloroprene rubber compositions shown in Table 3 are shown in Section g. According to the present invention, rubber mixtures containing non-sulfur-modified chloroprene rubber of 50% by weight or more have significantly improved adhesion to fibers while maintaining the advantages of chloroprene rubber such as heat resistance and compression fatigue resistance. There is.

Commissioner of the Japan Patent Office 1, Indication of the case Patent Order No. 108338 of 1982, 2 Name of the invention Rubber composition 3, Relationship with the person making the amendment Patent applicant address 3-2 Meiwa-dori, Hyogo-ku, Kobe City Mr. 15 Name
Band - Kagaku Co., Ltd. 4, Agent Address: 1-8-3-5 Shinmachi, Nishi-ku, Osaka, Date of Amendment Order: Showa (Month, Day, Showa) (Shipping Date: Showa)
6. Number of inventions increased by amendment Contents of the amendment (1) "150 ■/min" on page 12, line 12 of the specification was changed to "5
0 ■/min”.

(2) In Table 1 on page 15 of the specification, "-6,
Correct 8J to r6.8J.

that's all L23:

Claims (1)

[Claims] (1) (a) 50% non-sulfur modified chloroprene rubber
100 parts by weight of rubber containing 100 parts by weight or more; Indicates an integer. 2 to 15 parts by weight of a thiuram compound represented by (C) General formula (where Bs is each independently an alkyl group, an aryl group, a cycloalkyl group, or two Bs bonded together to form a compound with nitrogen) 0.3 to 5 parts by weight of at least one type of nickel selected from nickel dithiocarbamate represented by (representing a nitrogen-containing carbon ring) and nickel xanthate represented by the general formula (wherein R11 represents an alkyl group) A rubber composition comprising: