JPS58162602A - Modification method of rubber - Google Patents

Abstract

PURPOSE:To obtain a modified rubber having improved green strength and tensile stress, etc. after the vulcanization, by reacting a rubber having unsaturated carbon bonds with an organic compound having a carboxyl group and an aromatic halosulfonamide salt. CONSTITUTION:100pts.wt. rubber having unsaturated carbon bonds, e.g. polyisoprene rubber, is reacted with 0.01-10pts.wt. organic compound containing a carboxyl group, e.g. maleic anhydride, and aromatic halosulfonamide salt, e.g. chloramine-B, at 20-200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for modifying rubber having unsaturated carbon bonds.

Conventionally, in order to improve the unvulcanized physical properties and vulcanized physical properties of rubber, such as green strength and adhesion, polar groups such as carboxyl have been introduced into rubber, such as maleic anhydride and glyokyl. It is known that it adds to However, in many of these methods, the addition reaction causes secondary reactions such as gelation and molecular weight reduction of the rubber, resulting in a decrease in the strength properties of the rubber vulcanizate. It has the disadvantage of moderately low efficiency.

Therefore, the present invention has devised a method for modifying rubber that does not have such drawbacks (after various studies, 1 liter Ibara 411
- Discovered that the desired objective could be achieved by a novel rubber modification reaction in which a rubber having unsaturated carbon bonds was reacted with an organic compound having a carboxyl group and an aromatic sulfonic acid salt. Reached @K14.

Rubbers with unsaturated carbon bonds (hereinafter sometimes referred to as unkojiwa rubber or rubber) used in this invention include butadiene, inolune, piperylene, 2. Homopolymer rubbers of conjugated dienes such as s-dimethylbutadiene and chlorobrane, copolymer rubbers of 2@ or more of these conjugated dienes, or copolymer rubbers of these conjugated dienes and other monomers, cyclopentene , common unsaturated carbon aggregates such as cycloolefin one-time polymer rubbers such as norpurunene, polymer rubbers of dienes such as ethylidene norbornene and cyclopentadiene, polyolefin rubbers such as copolymers of said dienes and olefins, etc. Examples include rubber having the following. Typical examples include natural rubber, guanyl rubber, polyisogrene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, butadiene-isogrene copolymer rubber, inolone-styrene copolymer rubber, and butadiene-butadiene copolymer rubber. Isolone-styrene copolymer rubber, butadiene-piperylene copolymer rubber, butadiene-propylene alternating copolymer rubber, polypentenamer, ethylene-propylene-diene copolymer rubber, butyl rubber, butadiene-
Examples include acrylonitrile copolymer rubber, butadiene-isoluene-acrylonitrile copolymer rubber, polychlorine rubber, styrene-butadiene-styrene block copolymer rubber, styrene-isoglene-styrene block copolymer rubber, and the like.

The organic compound having a carboxyl group (hereinafter sometimes referred to as compound I) used in the present invention 114 has at least one carboxyl group, and if necessary, an acid bulk atom, a sulfur atom, It is possible to have a single nitrogen molecule or multiple bonds, and as long as it does not affect the reaction, the hydrogen atom in the molecule can be replaced with a halogen atom, an alkyl group, a cy group in an alkyl group, an acyl group, a hydroxyl group,
It can also be replaced with any substituent such as a nitrile group, anno group, or aldehyde group. Examples of its variants include acetic acid,
Propionic acid, thioglycolic acid, formyl 11%i
Long Shun, maleic acid, adipic acid, thiocidalicol, malic acid and other aliphatic carbone #! , Benzoka Shun, Narichiru Ken, Phenoxy Vinegar IllI! % Horn Rufueno Life *
*, aromatic acids such as phthalic acid and trimellitic acid - ★Alicyclic carboxylic acids such as cyclohexyl acetic acid and tetrahedral acid, alicyclic carboxylic acids such as glycine and glutamic acid, and anhydrides of these acids. . When used as an acid anhydride, it is preferable to coexist water at a ratio of 1 to 5 moles per liter of acid anhydride. These compounds I
The amount used is usually 100 parts by weight of rubber (LO1~10
Parts by weight. (If the amount of LO is less than 1 part by weight, the modification effect is small.

Salt of aromatic sulfone haloamide used in this book-1 (hereinafter sometimes referred to as compound 1) and Ck*, P
-) Alkali metal (e.g., sodium) salts, ammonium salts, and hydrates thereof, such as luenesulfonechloramide, penzenesulfonechloramide, naphthalenesulfonefluoramide, and xylenesulfonefluoramide. Note that the modification reaction rate is higher in non-hydrated materials.

The usage ratio of compound I and compound ■ is I/■ = 1/1 to 1
/4 is preferably 0, but it is not necessarily limited to this range.

The reaction in this R#JK is usually carried out in the presence of a suitable solvent or in the absence of a solvent in a rubber mixer. Industrially, it is advantageous to carry out the reaction in rubber cement after one polymerization has been completed. When using a solvent, any solvent can be used, such as aromatic solvents such as benzene and toluene, paraffin threads SM such as butane and hexane, and halogenated hydrocarbon group S copper such as chloroform and dichloroethane. Suitable materials are those that are inert and dissolve rubber. Compound! Solvents with a certain level of solubility for INK and INK are preferred for qIIK in view of the degree of reaction, but this is not necessarily the case. In addition, compound I
and summer may be added to the reaction system separately, or they may be mixed in advance and then added to the reaction system (however, in the latter case, it is necessary to add them to the reaction system promptly) . Compounds (1) and Natsu may be added in their entirety at the beginning of the reaction, or may be added in portions or continuously during one reaction. The reaction haze is not limited to %, but is usually in the range of -20C to 200C', preferably Q-1oOcr).
It is. The reaction time is also set appropriately from 10 seconds to 1 hour.For example, if a large amount of alcohol or hot water is added to the reaction in a solvent, the reaction will be stopped and the rubber will be removed. After removing various residues in the rubber that can be coagulated by washing as necessary, a modified rubber is obtained by drying.

The rubber thus obtained is treated with a vulcanizing agent, vulcanization accelerating steel,
With common rubber fabric additives such as vulcanization aids, reinforcing agents and softening agents. The unvulcanized compound obtained by electrolysis exhibits a strong green strength, making it easier to form and process, and this vulcanized product has excellent properties such as tensile response, so it is suitable for general use. Of course, applications that require these characteristics, such as tire carcass and tread, anti-vibration rubber, hoses, etc.
It is preferably applied to industrial belts, etc. It is also possible to convert this modified rubber into a latex state and use it for normal latex purposes.

In addition, from the point of view of improving the green strength of the unvulcanized compound, it is preferable to use polycarboxylic acids 1, such as malemonosyn, adipic acid, phthalic acid, trimellitic acid, or anhydrides thereof, as compound I. . However, in this case, if compound ■ is used in excess, rubber crosslinking reaction (gelation) will occur.
This may cause a decline in the processability and properties of the rubber.

However, even if there is a crosslinking reaction during drying and an increase in molecular weight, improvements in green strength of unvulcanized materials and tensile stress after processing are reported.

According to the method of the present invention, Compound I and Compound I were confirmed to be added to unsaturated rubber chains.

That is, Compound I is added to the rubber chain through an ester bond (when Compound 1 is a polybasic acid, a carboxyl group is introduced to the rubber chain), and Compound 1 is added to the rubber chain through the summer. It is assumed that halogens (and hydroxyl groups if active hydrogen coexists) are also introduced into the rubber chain. It is believed that the addition of these various active groups improves the green strength of the unvulcanized rubber sheet and the tensile stress of the individual pieces.

Next, the present invention will be explained in detail using examples.

The method for analyzing the modified rubber in each case, and the method for testing the physical properties of the non-JIll sulfurized product and vulcanized product of the modified rubber are as follows.

[Additional amount of chlorine, *S and carboxyl group to rubber]

After refining a small amount of denatured sample by repeating 21I of happy sedimentation, the chlorine content was determined by oxygen combustion flask method - working silver drop w
From lK, the i1m content was determined by the Kehrmehr method, and the carboxyl group content was determined by the simple neutralization method.

[Wallace availability]

Il[at 100C of the rubber unvulcanized compound by Wallace Ravid Plastometer.

[Green strength]

The unvulcanized rubber compound was press-molded at 100C for 5 minutes to form a 2-thick unvulcanized rubber sheet, and a dumbbell-shaped: Rxa S test piece was pounded to form a sheet of 25C1SOO■/m.
Elongation 500 when performing a tensile test at a tensile speed of in
The value of tensile stress in %.

[Vulcanization speed]

145C by oscillating disc rheometer
The time it takes for the torque added by a to reach the maximum torque of 95 ('r95).

[Tensile test]

1. Press vulcanize the unvulcanized rubber compound v145c' for a predetermined time to form a 2cm thick sheet. Dumbbell-shaped No. 3 test piece specified by TXB-6501K, punched, 500m at 25C
The test was carried out at a tensile speed of /win.

Example 1 Boiling rubber (98 cis-t4 bonds) 160fk
5tl) IIa water latent dissolved in toluene, glass 111tl
Compounds I and lv listed in Table 1 were each added as a methyl alcohol solution while stirring at 50C in a nitrogen atmosphere in a separable flask and reacted for 2 hours. Thereafter, the reaction solution was poured into a 31-ml methylalcohol solution to completely coagulate the rubber, and the coagulated material was washed as fine pieces.

The coagulum strips were then immersed in methyl alcohol 5J containing a 1132y anti-aging agent (2,6-di-tert-butyl-4-methylphenol), washed and washed. By drying overnight in a 22IE dryer, 1
Modified polyisoprene rubber samples shown in Table 11, B, Cj
, D, M1 was obtained.

Next, the modified rubber V and various compounding ingredients in the following formulation except for sulfur and vulcanization accelerator V were kneaded and mixed in a small shaking bumpereen now, and the resulting mixture was mixed with sulfur and vulcanization accelerator. was added on a wrinkled roll and kneaded to obtain a rubber unvulcanized compound II.
II did it.

Compounded rubber 10o (parts by weight) 1
1 AF Carbon 50 Aromatic Carbon 5 Sunka II Plow 5 Stearin II 2 Sulfur
2.5 Physical properties t-S of the obtained unvulcanized compound and vulcanized product were determined.

It is shown in table 1t'lK2.

Motoya - Samples B, O, and D all have high green strength and high chronic tensile stress, and Sample B, which has carboxyl groups in the rubber, has a remarkable improvement in green strength. I understand.

Example 2 In place of the rubber used in Example 1, polybutadiene rubber with 98 cis-t4 bonds was used, the reaction time was set to 70C, and the fifth
Modified samples ν and G shown in Table 1 were prepared in the same manner as in Example 1 using Compound I shown in the table and Summer.

Table 5: Unmodified voriptadiene rubber and samples P and G, 1
Physical properties of m1t mixture and vulcanizate t-*m The axis was added in the same manner as in Example 1, and the results shown in table k4 were obtained. However, the combination formula is the following kit.

Compounded prescription rubber 100 (weight II)
■Mu1 Carbon 50 Aromatic Oil 5 Zinc Wrinkle 3 Stearin II 2 Sulfur
t5 N-oxydiethylene-2-benzothiazylsul7enamide I N-(so-10bi-N'-phenyl-p-phenylenediamine t.

Table 4 shows that the modification of the present invention improves the green strength and 5ooqb tensile stress of the rubber.

Patent applicant: Zeon Corporation

Claims (1)

[Claims] A method for modifying rubber, which comprises reacting a rubber having an unsaturated carbon bond with an organic compound having a carboxyl group and a salt of an aromatic sulfone haloamide.