JPS5971345A - Rubber composition resistant to oil and weather - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent mechanical properties, without lowering the oil resistance and weather resistance of the constitutent rubbers, by compounding a halogenated ethylene/alpha-olefin/non-conjugated diene copolymer rubber with an unsaturated nitrile/conjugated diene copolymer rubber. CONSTITUTION:An unsaturated nitrile/conjugated diene copolymer rubber (represented by acrylonitrile/butadiene rubber) is compounded with a halogenated ethylene/alpha-olefin/non-conjugated diene copolymer rubber having a halogen content of preferably 0.5-50wt%, especially 0.5-10wt% (preferably chlorinated or brominated rubber) at a weight ratio of 95/5-5/95. The obtained composition can be used as a rubber product to which oil resistance and ozone resistance are required.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber composition. More specifically, the present invention provides an oil- and weather-resistant rubber composition with excellent mechanical properties, comprising an unsaturated di-11-conjugated zoene coelectrolyte rubber and a halogenated ethylene-α-olefin-nonconjugated noene copolymer rubber. be.

acrylonitrilutazoene copolymer (hereinafter N)
Unsaturated nitrite conjugated resins represented by BR (abbreviated as BR) are widely used industrially as oil-resistant rubbers, but they have the disadvantage of poor weather resistance. It would be of great industrial value if weather resistance could be improved without impairing NBH's excellent oil resistance. In order to solve this problem, various technologies have been developed to date, including a method of blending EPDM (abbreviated as EPDM) (Japanese Unexamined Patent Publication No. 56-1
09230, Japanese Unexamined Patent Publication No. 57-9 6 0 3 2)
, +2) EPDM and EPD grafted with vinyl chloride
M mixture (Japanese Unexamined Patent Publication No. 53-67754) or EPDM grafted with acrylonitrile (Japanese Unexamined Patent Publication No. 57-1989)
40544, JP-A-57-44647), and (3) a method of blending chlorinated polyethylene (JP-A-157-3836).

However, in the methods (1) and (2) above, the EPD
Since the oil resistance of EPDM grafted with M or a polar monomer is low, if the blending amount is increased to a level that improves the weather resistance of NBH, a problem arises in that the oil resistance of NBR is sacrificed. Furthermore, in method (3), it is not easy to achieve co-vulcanization with chlorinated polyethylene and NBRO, and the selection of the vulcanizing agent is limited.

The present inventors have solved these problems of the prior art (as a result of intensive research, we found that halogen-containing EPDM has superior oil resistance compared to other polymers, and can be co-processed with NBR in any proportion. The present invention provides an oil-resistant and weather-resistant rubber composition comprising a copolymer olefin of the present invention - a non-conjugated di-stone - as an essential component.

It is a copolymer of an unsaturated nitrile such as rylonitrile and a conjugated diene such as 1,3 butadiene or isoprene. Among these, % pressure acrylonitrile-butadiene rubber is preferred. The amount of bonded unsaturated nitrile in the copolymer is usually 20 to
60 Nik % good”! 'I, < +! 25
~50 M amount%.

The logonated ethylene-σ olefin-nonconjugated diene copolymer rubber (B) used in the present invention consists of ethylene, propylene, α-olefin such as butene-1, ethylidenenorbornene, dicyclopentadiene, propenylnorbornene, 1, Non-conjugated diene such as 4-hexadiene, 4,7,8゜9-tetrahydroindene, etc.
1! It can be obtained by halogenating the ethylene-α-olefin-nonconjugated diene copolymer rubber containing the above by a known method.

The $1 type of halogen is preferably chlorine or bromine. Chlorination can be carried out, for example, by crushing the copolymer rubber into fine particles and contacting them with molecular chlorine gas, or by making the fine particles into an aqueous suspension and contacting them with molecular chlorine, or by using n-hexane, n-hebutane. The copolymer rubber is dissolved in a hydrocarbon such as carbon tetrachloride, tetrachloroethylene, or halogenated hydrocarbon such as chlorobenzene, and the copolymer rubber is brought into a homogeneous solution state and brought into contact with molecular chlorine.

Bromination is carried out in the same manner as in homogeneous solution chlorination by dissolving the copolymer rubber in a hydrocarbon or halogenated hydrocarbon and bringing it into contact with molecular bromine.

In order to accelerate the reaction during these halogenation reactions, ultraviolet rays may be irradiated or peroxide may be added.

After the halogenation reaction, the process is carried out as follows: In the case of solid-phase chlorination, after the reaction is completed, excess chlorine is expelled through nitrogen gas to obtain a chlorinated copolymer rubber. After the reaction in a suspended state, the reaction product is washed with water and then dried to obtain a chlorinated copolymer rubber.

After chlorination or bromination in solution, for example, the reaction product is treated with an aqueous solution of caustic soda, washed with water, and then steam stripped to obtain a chlorinated or brominated copolymer rubber.

If the halogen content of the halogenated ethylene-α-olefin-nonconjugated diene rubber (B) used in the present invention is too low, the effects of the present invention cannot be obtained, and if it is too high, the balance of physical properties will be lost, so it is preferable 0.5-50% by weight
It is.

The halogenated ethylene prepared in this way is mixed with ordinary rubber compounding agents, such as carbon black, plasticizer, extender oil, anti-aging agent, vulcanization accelerator, and halogenated ethylene using a mixer such as a roll or Banbury mixer. -α olefin η- The mixing ratio with the non-conjugated diene copolymer rubber (B) varies over a wide range depending on the purpose, but is generally 9515 to 5/95.
(weight ratio).

The vulcanization system used in the present invention may be one that is normally used for crosslinking NBR and EpDM (combinations of sulfur and various vulcanization accelerators are used. Thiurams such as methylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dipenzothiazyl disulfide, N-
Thiazoles such as cyclohexyl-2-benzothiazolesulfenamide, imidacillins such as 2-mercaptoimidacillin, guanidines such as diphenylguanidine, dithiocarno(mates) such as zinc dimethyldithiocarbamate, Ingropil Zinc xanthate and metal compounds such as zinc oxide, magnesium oxide, litharge, calcium carbonate, magnesium carbonate, etc. may be blended as necessary.The blending amount of these additives is determined based on the optimum vulcanizate properties, processing stability, etc. (There are no restrictions on the amount used.)

Vulcanization is usually carried out by heating at 120-200°C for 0.5-60 minutes.

The rubber composition according to the present invention is used in rubber products that require oil resistance and ozone resistance, such as hoses such as oil hoses, fuel hoses, gas hoses, brake hoses, Freon hoses, cover materials for hoses, Examples include industrial parts such as backings, gaskets, O-rings, belts, linings, oil seals, dust boots, etc., and parts for aircraft, road vehicles, etc.

EXAMPLES The present invention will be specifically explained below with reference to Examples.

The test method for vulcanized rubber in the following examples is JIS
K630].

The amount of compounding agents used and the halogen content are all parts by weight and percent by weight.

Example 1 EPDM (EP57C manufactured by Japan Synthetic Rubber Co., Ltd.) 2502 was dissolved in carbon tetrachloride, and chlorine 2002 was blown in at 55 to 60°C to produce chlorinated EPDM (hereinafter α-EPDM) with a chlorine content of 3%.
-1) was obtained. This α-EPDM-1 and NB
R (manufactured by Japan Synthetic Rubber, N25O8), NBR/
α-EPDM = 70/30.50150 ratio with the following formulation: 250 cc Kneaded in a blast mill, then mixed with a thickening agent and vulcanization accelerator with a roll, and the resulting mixture was heated at 160°C After press vulcanization for 20 minutes, a tensile test, an oil resistance test, and a weather resistance test were conducted. The results are shown in Table 1.

The NBR/α-EPDM-1 rubber composition exhibits excellent mechanical properties and good oil resistance and weather resistance.

Blending prescription Polymer 100 (parts) HAF black 60 Naphthenic oil 10 DOP l
5 Zinc white No. 1 5 Stearic acid l Accelerator CBS ”) 1.5# MB
T*2) 0.4 sulfur
l・5 *1) N-cyclohexyl-2-benzothiazolylsulfenamide *2) Mercabutopenzothiazole Table 1 *3 No cracks *4 Few cracks that can be confirmed with the inner eye (displayed according to JIS) Comparative example 1 In the same manner as in Example 1, a similar test was conducted on a rubber composition containing pre-chlorinated EPDM (manufactured by Japan Synthetic Rubber Co., Ltd., EP57C) instead of α-EPDM-■. The results are shown in Table 2.

*Many cracks that can be confirmed with a 510x magnifying glass (displayed according to JIS) Example 2 250r of EPDM (the above-mentioned EP57C) is dissolved in carbon tetrachloride, and 600f of chlorine is blown in at 55 to 60°C to produce chlorine with a chlorine content of 15%. EPDM (hereinafter abbreviated as α-EPDM-2) was obtained. Using this rubber composition containing α-EPDM-2 and NBR (N23O8), Example-
A tensile test, an oil resistance test, and a weather resistance test were conducted in the same manner as in 1. The results are shown in Table 3. NBR/Ct-EPDM
-2 The rubber composition exhibits good oil resistance and weather resistance in terms of mechanical properties.

Table 3 - Example 3 EPDM (manufactured by Nippon Gosei Go, EP33) 1255'
was dissolved in carbon tetrachloride and chlorine was added at 55 to 370 ml.
2 was blown into chlorinated EPDM with a chlorine content of 38% (hereinafter α-
(abbreviated as EPDM-3) was obtained. This α-E P D
A tensile test, an oil resistance test, and a weather resistance test were conducted in the same manner as in Example 1 using M-3 and NBR (N230S described above) with the following formulation. The results are shown in Table 4. NBR/α-
The EPDM-3 rubber composition exhibited good mechanical properties as well as good oil resistance and weather resistance.

Blending recipe (parts) Polymer 100 HAF blank 60 Naphthenic oil 10DOP
15Mg0
'4 Zinc flower No. 1
5 Stearic acid l Accelerator CB S L, 5I M
BT O,4 sulfur
1.5 Table 4 Comparative Example 2 A similar test was carried out in the same manner as in Example 1, using a rubber composition containing EPDM (above-mentioned EP33) in place of α-EPDM-1. The results are shown in Table 5.

Table 5 *6 Many cracks that can be seen with the naked eye (displayed according to JIS) Example 4 EPDM (EP33 described above) 2509 was dissolved in carbon tetrachloride, and a carbon tetrachloride bath solution containing bromine (150f as Br2) was prepared.
was added dropwise at a temperature of 70 to 750 to obtain brominated EPDM (hereinafter abbreviated as Br-E PDM) having a bromine content of 16.6%. This Br-E PDM and NBR (the aforementioned N2
A tensile test, an oil resistance test, and a weather resistance test were conducted in the same manner as in Example 3 using 3 (lS). The results are shown in Table 6. NBR/Hr-EPDM has excellent mechanical properties and exhibits good oil resistance and weather resistance.

Table 6 Procedural Amendment April 12, 1982 Kazuo Wakasugi, Director General of the Patent Office 1, Indication of the Case Patent Application No. 180025/1983 2 Name of the Invention Oil and Weather Resistant Rubber Composition 3 Case of the person making the amendment Relationship with Patent Applicant Name (417) Nippon Godo Gomu Aji Shiki Kaisha 4 Agent Address Toranomon 40, Toranomon 5-13-1, Minato-ku, Tokyo Content ill “Preferably 0.5 to 5” on page 6, line 11 of the specification
0 weight is in charge. ” followed by “Particularly preferably 0.5 to 1
It is 0 weight t%. ” is added.

(2) r 9515 to 5/95 (weight ratio) on page 7, line 3. Add the following sentence after ``.

[In addition, non-halogenated ethylene-α olefin-nonconjugated tsene copolymer rubber and heronated ethylene-α
It may also be used by mixing with an olefin-nonconjugated diene copolymer rubber and adjusting the chlorine content to an appropriate level within the above range with an unsaturated nitrile-conjugated tzene co-electropolymer rubber (A). (3) Insert the following sentence after Table 6 on page 18: [
Example 5 540 g of EPDM (manufactured by Nippon Synthetic Rubber, EP65X) was dissolved in n-hexane and treated with chlorine sogy at 55-60°C.
H blowing, chlorine included! 1.8 inches of chlorinated EPDM (hereinafter abbreviated as α-EPDM-5) was obtained. This α-EPDM-
5 and NBR (manufactured by Japan Synthetic Rubber, N2208) and N B
R/Cl-EPDM=60/40
A tensile test, an oil resistance test, a weather resistance test, and a vulcanization adhesion test with SBR were conducted using the following ratios. The results are shown in Table 7.

Blending recipe (parts) Polymer 100 HAF black 60 Naphthenic oil 20 DOP 10 Zinc white No. 1 5 Stearic acid 2 Accelerator CB 8 1.2 Sulfur 1.5 Example 6 EPDM (the aforementioned EP 65 X), 540 g
Chlorinated EPDM (hereinafter α-E
(abbreviated as PDM-6)? Obtained. This α-EPDM-6 and N
A tensile test, an oil resistance test, a weather resistance test, and a vulcanization adhesion test with SBR) a1' were carried out in the same manner as in Example 5 using BR (N2208)+2 as described above. The results are shown in Table 7.

Example 7 250 g of EPDM (the aforementioned EP65X) was dissolved in carbon tetrachloride, and 160 g of chlorine was added at 55 to 60°C.
12% chlorinated EPDM (hereinafter abbreviated as α-EPDM-7)? Obtained. This α-EPDM-7 and NBR (the above-mentioned N2
208) 'Tensile test, oil resistance test, weather resistance test, and vulcanization adhesion test with SBR' were conducted in the same manner as in Example 5 using Y. The results are shown in Table 7.

Comparative Example 3 A similar test was conducted in the same manner as in Example 5 on a rubber composition containing pre-chlorinated EPDM (the aforementioned EP65X) Y instead of α-EPDM-5, and the results were as follows.
Shown in the table.

From the results in Table 7, it is clear that the rubber composition of the present invention significantly improves oil resistance, compression set, and vulcanization adhesion to curved rubber without significantly improving one-wave breakage characteristics and weather resistance. It is.

+1...710 sulfur layer 160-CX of unvulcanized raw pond comrade
30 minutes (SBH formulation) 5BR1500100 (parts) FIAF Black 50 Marromatic Oil 5 Zinc White No. 1 3 Stearic Acid 1 Accelerator BBS' 2 1 Sulfur 1.75 Blue 2...N
-Tertiary-butyl-2-benzothiazolylsulfenamide” 305

Claims (1)

[Claims] Unsaturated nitrile-conjugated tsene copolymer rubber (A) Tohalonated ethylene-α-olefin-non-conjugated tsene copolymer rubber (B) Contained as an essential component, blending ratio of the above-mentioned prison component and component (B) is 95=5 to 5:95 (weight ratio).