JPH01234440A - Rubber composition - Google Patents

Abstract

PURPOSE:To obtain a rubber composition having excellent green strength and tensile strength, etc., after vulcanization and free from reinforcing agent and filler, by compounding a vulcanizing agent to a specific modified rubber. CONSTITUTION:The objective composition essentially free from reinforcing agent and filler is produced by compounding (A) a modified rubber produced by reacting (i) a rubber having unsaturated bond (e.g., natural rubber or polyisoprene rubber) with (ii) an organic compound having the group of formula -CH=N- (e.g., benzylidenemethylamine) and (iii) an organic acid halide having the group of formula COX (X is halogen) in the presence of (iv) a Friedel-Crafts catalyst (e.g., BF3 or AlCl3) with (B) a vulcanizing agent (e.g., sulfur).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pure rubber composition having excellent green strength and tensile stress after vulcanization.

(Prior Art) Conventionally, in order to obtain rubber compositions with improved green strength and adhesiveness after vulcanization, rubbers into which polar groups such as carboxyl groups have been introduced, such as maleic anhydride and glyoxal, have been used. It is known to use rubber added with However, these rubbers have the disadvantage that their strength properties as a vulcanizate are insufficient because side reactions such as gelation of the rubber and reduction in molecular weight are likely to occur during the modification reaction.

(Problem to be Solved by the Invention) Therefore, as a result of various studies in order to develop a modified rubber composition that does not have such drawbacks, the present inventor has developed a method for reacting a specific compound in the presence of a Friedel-Crafts catalyst. The composition is characterized by blending a vulcanizing agent with the modified rubber obtained by the process and containing substantially no reinforcing agent or filler, and the composition is characterized by excellent green strength and tensile stress of the vulcanizate. The present invention was achieved by discovering that

(Means for Solving the Problems) That is, the present invention provides an organic compound having a group represented by the formula -CH=N- and 2COX (where X is A rubber composition characterized by blending a vulcanizing agent with a modified rubber obtained by reacting an organic acid halide having a group represented by (halogen) and containing substantially no reinforcing agent or filler. It is something that provides something.

Examples of the rubber having an unsaturated carbon bond (hereinafter sometimes referred to as unsaturated rubber or rubber) used for preparing the modified rubber in the present invention include butadiene, isoprene, piperylene, 2,3-dimethylbutadiene, and chloroprene. Homopolymer rubbers of conjugated dienes, copolymer rubbers of two or more of these conjugated dienes, or copolymer rubbers of these conjugated dienes with other monomers, cycloolefin rubbers such as cyclopentene, norbornene, etc. ring polymer rubber,
Typical rubbers having unsaturated carbon bonds include polymers of dienes such as ethylidene norbornene and cyclopentadiene, and polyolefin rubbers such as copolymers of dienes and olefins. As a typical example,
Natural rubber, guanyl rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber,
Butadiene-isoprene copolymer rubber, isoprene-styrene copolymer rubber, butadiene-isoprene-styrene copolymer rubber, butadiene-piperylene copolymer rubber, butadiene-propylene alternating copolymer rubber, polypentenamer, ethylene-propylene-diene Copolymer rubber, butyl rubber, butadiene-acrylonitrile copolymer rubber, butadiene-isoprene-acrylonitrile copolymer rubber, polychloroprene rubber, styrene-butadiene-styrene block copolymer rubber, styrene-isoprene-styrene block copolymer rubber Examples include.

The compound having a group represented by the formula -CH,N- used in the present invention (hereinafter sometimes referred to as compound ■) is:
More specifically, in the general 2R-CH=NR', R
, R' are aliphatic, alicyclic, or aromatic residues, and R and R' contain atoms such as an alkoxyl group, a cyano group, a carboalkoxyl group, a carboxyl group, and a dialkylamino group. They can have groups as appropriate.

Specific examples include benzylidenemethylamine, benzylidenebutylamine, benzylideneaniline, benzylidenecyclohexylamine, propylidenebutylamine, propylideneaniline, cyclohexylidenebutylamine, cyclohexylideneaniline, ethoxybenzylidenebutylaniline, 4-carpoxylbenzylidenebutyl Aniline, 4-carbomethoxybenzylidenebutylamine, benzylidene 4-cyanoaniline, benzylidene 4-carboxylaniline, dimethylaminobenzylidenebutylaniline, and the like.

In the present invention, the organic acid halide having a group represented by the formula -COX (hereinafter sometimes referred to as compound Ⅰ) is, more specifically, in the -a formula R'-COX, X is a halogen, and R'' is a fatty acid. Typical examples thereof include compounds having group, alicyclic, or aromatic residues, and R' may have an atomic group such as an alkoxyl group or a halocarbonyl group as appropriate.

Specific examples include acetyl chloride, acetyl bromide, benzoyl chloride, benzoyl bromide, carbomethoxybenzoyl chloride, oxalyl chloride, terephthalic acid chloride, and the like.

The amounts of Compounds I and (2) to be used are not particularly limited, but are usually 0.001 to 3 parts each per 100 parts by weight of unsaturated rubber.
0 parts by weight, preferably o, i to 10 parts by weight.

As the Friedelkraff catalyst in the present invention, commonly known ones can be used. Typical examples thereof are metal or metalloid halides, such as Be, B,
An, Si+ P, S, Ti+ V, Pet
Zn.

Ga, Ge, As, Se, Zr, Nb+M
o, Cd+ Sn, Sb+ Te.

Elements such as Ta, W, Hg+ 8+, υ or PO,
Sea, SO.

These include halides of oxygen-element bonds such as so, vo, organic halides, and complexes thereof. More specifically, BFI, BF30 (CJs) 2
゜(CL)zBF, BCI 3. (41C1!+ A
lBr3゜(CzHs) AffiCjl! z, POCj
L, T1Cf! , n, VCf4. F+oC1brSnC
jl! 4. (CFIz) SnC! ! ,z, 5bCj
l! ,, TeCj! 4. TeBrn+FeC1
5 and 'AC1b. Of these, 5n
C1a, 5bCj! s, AlC1x, etc. are particularly suitable because they have a high reaction rate and cause few side reactions.

The amount of Friedel-Crafts catalyst used is not particularly limited, but is usually 0.01 to 10 mol, preferably 0.05 to 3 mol, based on compound H.

The modification reaction of the present invention is usually carried out in a solvent.

As the solvent, any solvent can be used, such as aromatic solvents such as benzene and toluene, (cyclo)paraffinic solvents such as butane, hexane, and cyclohexane, and halogenated hydrocarbon solvents such as chloroform and dichloroethane. Suitable materials are those that are inert to the reaction and can dissolve the rubber. It may also be carried out in a rubber kneader in the absence of a solvent.

Compound (1), compound (2), and Friedel-Crafts catalyst may be added in their entirety to the reaction system at the beginning, or may be added in portions or continuously during the reaction. Also, compound I, compound ■
and Friedel-Crafts catalyst may be added to the reaction system separately, or these kings or kings may be mixed in advance and then added to the reaction system.

When carrying out the reaction, it is necessary to maintain the reaction system in an anhydrous state or under a limited amount of water (usually 1100 pp or less).

The reaction temperature is not particularly limited and is usually -20°
C to 180°C, preferably -10°C to 120°C. The reaction time is also not particularly limited, and is appropriately set between 10 seconds and 10 hours.

When the reaction is carried out in a solvent, for example, by adding a large amount of alcohol or alkaline aqueous solution, the reaction can be substantially stopped and the rubber can be coagulated.

Next, various residual substances in the rubber are removed by washing as required, and then dried to obtain a modified rubber.

Typical vulcanizing agents used in the composition of the present invention include sulfur and sulfur donors such as thiuram and thiazole, but other vulcanizing agents include peroxides such as dicumyl peroxide, polyamines, metal oxides, and urethane. Vulcanizing agents, resin vulcanizing agents, etc. can also be used. Vulcanization accelerators for sulfur-based vulcanizing agents include sulfenamides, thiurams, thiazoles, guanidines, mercaptotriazine, aldehyde-amines, etc.
As the activator, metal compounds such as zinc oxide, magnesium oxide, calcium hydroxide, and lead carbonate, carboxylic acids such as stearic acid and oleic acid, and zinc stearate are used.

In addition to a vulcanizing agent system such as a vulcanizing agent, a vulcanizing accelerator, a vulcanizing accelerator/activator, the composition of the present invention may also contain a softening agent, a tackifier, a coloring agent, and an anti-aging agent as desired. , ordinary rubber compounding agents such as ozone deterioration inhibitors, and other diene rubbers.

The method of mixing the components constituting the composition of the present invention is not particularly limited, and various rubber kneaders are usually used.

(Effects of the Invention) The pure rubber composition of the present invention has extremely excellent green strength and tensile stress after vulcanization, so it can be used not only for thread rubber, rubber bands, tubes, and rubber threads for golf balls, but also for ordinary pure rubber. Suitable for use in compositions.

According to the method of the present invention, it was confirmed that Compound I and Compound (2) are added to unsaturated rubber chains.

It is believed that the addition of these compounds improves the green strength of the unvulcanized rubber compound, the tensile stress, etc. of the vulcanized product.

(Example) The present invention will be described in more detail with reference to Examples below. Note that parts and percentages in Examples and Comparative Examples are based on weight unless otherwise specified.

The methods for preparing unvulcanized blends and vulcanized products of modified rubber and the methods for testing their physical properties are as follows.

[Blend Mooney viscosity] 10 according to the test method described in JIS K-6300
Measured at 0°C.

[Vulcanization speed]

145° by oscillating disc rheometer
It is expressed as the time (T9S) until the torque measured at C reaches 95% of the maximum torque.

[Tensile test]

The unvulcanized rubber compound was press-vulcanized at 145°C for a predetermined period of time to give a thickness of 2 mm, and a dumbbell-shaped No. 3 test piece specified in JIS K-6301 was punched out.
The tensile speed was mn+/min.

[Green strength]

The unvulcanized rubber compound was press-molded at 100°C for 5 minutes to form an unvulcanized rubber sheet with a thickness of 2 mm, and dumbbell-shaped JIS No. S test pieces were punched out.
It is shown as the value of tensile stress at 500% elongation when a tensile test is conducted at a tensile rate of mm/min.

Example 1 Polyisoprene rubber (98% cis 1,4 bonds) 160g
was dissolved in dehydrated benzene of 31, and while stirring at 25°C under a nitrogen atmosphere in a closed glass container (separable flask), the compound 1. listed in Table 1 was dissolved. II and Friedelkrach catalysts were each added as benzene solutions.
Allowed time to react.

Thereafter, the reaction solution was poured into 31 methyl alcohol to completely coagulate the rubber, and the coagulated material was washed as small pieces. Then methyl alcohol 3I containing about 2 g of anti-aging agent (2,6-di-tert-butyl-4-methylphenol)! The coagulated pieces were immersed in the sample, washed, and then dried in a vacuum dryer overnight to obtain modified polyisoprene rubber samples A, B, C, and D.

Next, an unvulcanized rubber compound was prepared using the obtained sample rubber according to the following compounding recipe.

Compounding prescription sample rubber 100 (parts) Activated zinc white 3 Stearic acid 1 Sulfur 2.5 Tsukusera F" 1.2* Vulcanization accelerator manufactured by Iruuchi Shinko Kagaku Kogyo Co., Ltd. (dibenzothiazyl disulfide, diphenylguanidine, hexamethylenetetramine) Mixed product) Table 2 shows the measurement results of the physical properties of the unvulcanized mixture and the vulcanized product.

It can be seen that the green strength and 300% tensile stress of Examples A to D of the present invention are significantly improved compared to unmodified polyisoprene rubber.

Example 2 Polyisoprene rubber (90% cis 1,4 bonds) 300g
41 in dehydrated cyclohexane, and while stirring in a closed glass container (separable flask), compound ①, compound ②, and Friedel-Kraf's catalyst listed in Table 3 were dissolved in benzene at 25°C under a nitrogen atmosphere. After adding as a solution and reacting for 60 minutes, 100 mj2 of methanol was poured in (it is assumed that this stopped the addition reaction).

Thereafter, the reaction solution was poured into acetone/methanol mixture solution No. 41 to completely coagulate the rubber, and the coagulated product was washed as small pieces. Then about 2g of anti-aging agent (2,6
- di-tert-butyl-4-methylphenol) in methyl alcohol 32;
After washing, sample E was dried in a vacuum dryer overnight.

I got an F.

Next, Table 4 shows the physical properties of the unvulcanized compound and vulcanized product prepared in the same manner as in Example 1.

It can be seen that the green strength and tensile stress of Examples E and F of the present invention are improved by 300% compared to the unmodified product.

Patent applicant: Zeon Corporation

Claims (1)

[Scope of Claims] An organic compound having a group represented by the formula -CH=N- and a group represented by the formula -COX (X is a halogen) is added to a rubber having an unsaturated bond in the presence of a Friedel-Crafts catalyst. 1. A rubber composition comprising a vulcanizing agent blended into a modified rubber obtained by reacting an organic acid halide having a group, and containing substantially no reinforcing agent or filler.