JPS60245652A - Age resistor for rubber - Google Patents

Abstract

PURPOSE:To obtain a sulfur-crosslinking age resistor for rubber, which has excellent ozone resistance, flex resistance, and heat resistance, and maintains the effect for a long time, by compounding a bismaleimide and p-phenylenediamine. CONSTITUTION:An age resistor comprising a bismaleimide of formula I [e.g. N,N'-hexamethylenebismaleimide or N,N'-(m-phenylene)bismaleimide] and a p- phenylenediamine of formula II (e.g. N-phenyl-N'-isopropyl-p-phenylenediamine). This age resistor is added to a synthetic rubber such as a styrene-butadiene copolymer rubber, and an ethylene-propylene-diene terpolymer rubber as well as to a natural rubber, usually in an amount of 0.1-7pts.wt. based on 100pts.wt. rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-aging agent for combs, and more particularly to an anti-aging agent for sulfur-crosslinked rubbers having excellent ozone resistance, bending resistance and heat resistance.

In general, rubber products such as natural rubber and synthetic rubber age due to ozone, repeated bending, and heat.
It is well known that it eventually becomes unusable.

Many methods have been proposed for the purpose of preventing such aging, but most of them involve the use of various anti-aging agents, such as N-phenyl-N+-alkyl-P-phenylenediamine, N,N'-diallyl-p p-phenylene diamines such as -phenylene diamine are used.

However, in recent years, as tires have become more radial and belt conveyors have become faster, there has been a strong desire for rubber products to maintain a long lifespan under harsh conditions. It was not possible to adequately deal with the situation.

For these reasons, Fushikushi has developed an anti-aging agent that has excellent performance in terms of two-dimensional resistance, bending resistance, and heat resistance, and Shikoshi has developed an anti-aging agent that maintains its performance even after long-term use. As a result of intensive research, we found that hismaleimides and p.
-An anti-aging agent made by a new group consisting of phenylene diamines has the ozone resistance, bending resistance and heat resistance of sulfur-linked comb products, and In addition, they found that the performance can be maintained even when used for a long time, and completed the present invention.In other words, the present invention is based on the general formula (I) , cycloaliphatic groups, aromatic groups, alkyl aromatic groups which may contain heteroatoms such as 0, N, S in the chain or in side substituents); class and general formula (old (formula, R1
' and R2 each independently represent an aliphatic group, an aromatic group, or an alkyl aromatic group. ) A sulfur-crosslinked anti-aging agent for rubber is provided.

Hismaleides, which are one of the components of the present invention, are known as co-crosslinking agents in peroxide crosslinked rubber as described in U.S. Pat. When used, the performance such as ozone resistance and heat resistance was not compromised at all, but rather the durability performance was reduced.

Furthermore, p-phenylenediamines, which are component l) of the present invention, are not fully satisfactory as anti-aging agents when used alone.

However, when using sulfur-crosslinked combs with hismaleimides and 1]-phenylenediamines, unexpected chemical changes may occur, or they may not react well when used alone. They must have discovered that they could obtain an extremely excellent cup-oson effect that was previously unavailable, and that this effect could maintain excellent performance over a long period of time, as well as provide excellent bending resistance and heat resistance. Examples of the hismaleimides represented by the general formula (T, ) of the present invention include N,N'-ethylene hismaleimide N, N'-hexamethylene bismaleimide N, v-dotecamethylene hismaleimide N, N''- (2, 2, 4-1
-dimethyl-hexamethyleneno)hismaleimide N, N'-(oxydiprohyno)hismaleimide N
, N'-(amino-dipropylene) histoimide N,
N'-(ethylene-dioxydipropylene) hisimide N, N'-(1,4-cyclohequinleno) hismaleimide N, N'-(1,3-cyclohexyl)) hismaleimide N, N'- (methylene-1,4-synchlohequinleno)hismaleimide N,N'-(isobrobiliteno1,4-dicyclohexylene)hismaleimide N,N'-(oxy-1,4-dicyclohequinleno)his Maleimide N, N'-(m-). Nilene) Bismaleimide N, N'
-(p-phenylene)hismaleimide N, N'-(o-
phenylene) hismaleimide N, N'-(1,8-naphthylene) hismaleimide N, N'-(], , ]4
-Naphthylenohismaleides N,N'-(1,5-
naphthyleno) hismaleimide N, N'-(8, B'-
Dimethyl-4,4'-hyphenylene) bismaleimide N, N'-(8,3'-dichloro-4,47-hyphenylene) hismaleimide N, N'-(2,4-pyridyl) hismaleimide i~N
, N'-(2,6-pyridyl)hismaleimide N, N'
-(4-Methyl-2,6-pyridyl)bismaleimide N,N'-(], ]4-anthraquinonediylhismaleimide N+N'-(m-1-rylene)hismaleimide N,N'
-(p-tolylene)hismaleimide N,N'-(4,6
-cymethyl-1,3-)nireno)hismaleimide N, N'-(2,8-dimethyl-1,4-phenylene)hismaleimide N, N'-(4,6-dichloro-1,3-phenylene)his maleimide N, N'-(5-chloro-1,8-phenylene) hismaleimide N, N'-(5-hydroxy-1,8-phenylene) hismaleimide N, N'-(5-methquin-1, ni 1-Fueni 1.・
)) Hismaleimide N, N'-(m-quinrylene) Hinuma1/IE FN,
N'-(p-quinrylene) hismaleimi 1ζN, N'-
(,'narenji p-fugonileno) bismaleimide N, N'-(isopropyritine-di-p-phenylene)
Hismaleimide N, N'-(oxo-di-p-phenylene)bismaleimide N, N'-(thio-di-p-phenylene)hismaleimide N, N'-<dithio-di-p-phenylene)hismaleimide N , N'-(sulfo-di-p-phenylene) hismaleimide N, N'-(carbonyl-di-p-phenylene) hismaleimide, etc. Also, the p-phenylenecyamines used in the present invention include: For example, 1-phenyl-he'-isopropyl-p-phenylenethiaenN-phenyl-N'-5ec-butyl-p-phenylenediami-/N-phenyl-jN'-1,2-dimethylpropyl- p
-phenylenediamine N~phanyl-N' -1,8-dimethylphthyl p-
Phenyl diamino N-phenyl-N'-5ec-octyl-p-phenylenediamine N, , N'-diphenyl-p-phenylenediamine N, N'-ditolyl-p-phenylenediamine N, N'
-Dixylp-phenylenesia ε-N, N'-C S
e C-butyl-p-phenylenesia grass N, N'-
The present invention is an anti-aging agent for sulfur-linked combs, which is composed of hismaleimides and p-phenylenediamines. The ratio is usually 80-20 to 20-8
The anti-aging agent for combs of the present invention, which has a ratio of 0, preferably 65 to 85 to 35 to C5, is suitable for natural rubber as well as styrene-butadiene copolymer com, acrylonitrile e-butadiene copolymer comb, and ethylene-propylene-diene copolymer comb. It is added to synthetic combs such as ternary copolymer rubber/polybutadiene comb and polyisoprene comb, and the amount added to the comb is 01 to 7 parts per 100 parts of rubber, preferably 05-5 Ashi Shato. Addition to comb in the usual way,
For example, the additives may be added using a Hanbury Mikiyuki Nato oven.In this case, the hismaleimides and p-phenylenecyamines may be added separately, or they may be mixed in advance. may be added.

In addition, when using the anti-aging agent of the present invention, other additives may be added as necessary, such as 2.2.4-trimethyl-1,2-
A dihydroquinoline polymer or the like may be used in combination.The present invention will now be explained with reference to Examples.

In addition, the word "example middle part" indicates the heavy rod part.

Example 1 100 parts of natural rubber, 45 parts of HA F carboxylic acid, 5 parts of zinc white
1 part, 25 parts of oil, 1 part of stearic acid, 5 parts of process oil, 3 parts of wax, N-oxydiethylene-henodithiazylsulfenoamide (105 parts of vulcanization accelerator and anti-aging agent shown in Table 1) were blended using a 6-inch oven roll in a conventional manner and vulcanized at 150°C for 30 minutes to prepare one sample.

Using this sample, ozone aging, heat aging, and flex cracking tests were conducted.

In addition, each test is based on JIS K-680], and the onono aging test was performed using an ozone weather meter at an ozone concentration of 50 pphm, a temperature of 40°C, and a dynamic elongation rate of 20.
Measure the time until rack occurs, which can be measured with the naked eye in %. In the flexural crack test, two original silk kisses are placed on the sample, and the length of the kiss after bending and convexing 10,000 times is M force EL.

Thermal aging = a was heat aged at 100°C for 48 hours using a car oven, and then the retention rate (%j) of fracture arc was measured. Samples that had been heat-treated for 24 hours at 100° were also tested.

The results are shown in Table 2.

＼ Example 2 Suji [・Nbutane Eno Rubber 100 & 15. 50 parts of HAF carhono, 5 parts of process oil, 5 parts of curved lead flower, 3 parts of nutearinoic acid, 2.5 parts of sulfur, 3NS wax, N-chlorohexylhenzothiadylsulfenade (vulcanization accelerator)
A test was conducted in the same manner as in Example 1 on a product containing 1 part and 1 anti-aging agent shown in Table 1, mixed with 6 inches/oven roll, and vulcanized at 160°C for 30 minutes. ·Ta.

The heat aging conditions were 110° C. for 48 hours, and samples previously heat-treated at 110° C. for 24 hours were used for the Oson deterioration and flex crack tests.

The results are shown in Table 2.

Continuing from page 1■Int, CI,' Identification symbol Internal serial number 0
Author: Haruki Okamura, Haru Company, Konohana-ku, Osaka City Inventor: Eizo Okino, Haru Company, Konohana-ku, Osaka City

Claims (1)

[Claims] General formula (I) 0 111 (wherein R is a divalent acyclic aliphatic group, a cycloaliphatic group, an aromatic group, an alkyl aromatic group, and these groups are present in the chain or bismaleimides of the general formula (II) (wherein,
R1 and R2 each independently represent an aliphatic group, an aromatic group, or an alkyl aromatic group. ) A sulfur-crosslinked anti-aging agent for rubber, characterized by comprising p-phenylenediamines represented by the following.