JPH0699515A - Oil resistant hose - Google Patents

Abstract

PURPOSE:To provide an oil resistant hose constituted of the vulcanized substance of acryl elastomer containing a carboxyl group wherein physical properties such as tensile strength are not deteriorated even by steam vulcanization. CONSTITUTION:An oil resistant hose is constituted of the steam-vulcanized substance of acryl elastomer containing a carboxyl group or of the blended material of both the same and acryl elastomer containing the carboxyl group which is copolymerized with ethylene. Herein maleic acid monoalkyl is copolymerized as a monomer containing the carboxyl group and the obtained substance is used.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oil resistant hose. More specifically, it relates to an oil resistant hose made of a steam vulcanized product of acrylic elastomer.

[0002]

2. Description of the Related Art When an oil resistant hose is manufactured by utilizing the characteristics of an acrylic elastomer, steam vulcanization is generally performed. However, steam causes a large decrease in physical properties such as tensile strength of the vulcanized product. Further, when steam vulcanization is performed using an acrylic elastomer copolymerized with ethylene, physical property deterioration is not observed, but the surface roughness and deformation of the vulcanized molded product are large, and further in the kneading step and extrusion step. Not only does it have high tackiness and poor processability, but it also has the drawback of being extremely poor in oil resistance.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an oil resistant hose made of a carboxyl group-containing acrylic elastomer vulcanizate which does not deteriorate physical properties such as tensile strength even by steam vulcanization.

[0004]

The object of the present invention is as follows.
Achieved by an oil resistant hose consisting of a steam vulcanized product of a carboxyl group-containing acrylic elastomer or a blend of a carboxyl group-containing acrylic elastomer obtained by copolymerizing ethylene with this, wherein monoalkyl maleate is a carboxyl group-containing monomer. Is used as a copolymer.

A blend rubber composition comprising a carboxyl group-containing acrylic elastomer obtained by copolymerizing a monoalkyl maleate as a carboxyl group-containing monomer and a carboxyl group-containing acrylic elastomer obtained by copolymerizing ethylene is first prepared in the following manner. It has been proposed by the applicant (JP-A-3-74452). However, nothing is mentioned therein that such a blended rubber composition still gives a useful oil resistant hose by steam vulcanization.

As the alkyl acrylate of the component (a) which forms the carboxyl group-containing acrylic elastomer,
Carbon such as methyl acrylate, ethyl acrylate, n- or iso-propyl acrylate, n- or iso-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-cyanoethyl acrylate An alkyl acrylate having an alkyl group of the number 1 to 8 (including those having a substituent such as a cyano group) is used,
Ethyl acrylate or n-butyl acrylate is preferably used.

Examples of the alkoxyalkyl acrylate as the component (b) include those having 2 to 8 carbon atoms such as methoxymethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate and 2-butoxyethyl acrylate. An alkoxyalkyl acrylate having an alkoxyalkyl group is used, preferably 2-methoxyethyl acrylate, 2-
Ethoxyethyl acrylate is used.

When both the components (a) and (b) are used, the former is about 10 to 90 mol%, and the latter is about 9 mol%.
It is generally used in a proportion of 0 to 10 mol%.

A part of these components (a) and / or (b), specifically up to about 20% by weight, may be replaced with another copolymerizable monomer and copolymerized. Examples of the copolymerizable monomer include propylene, vinyl chloride, vinylidene chloride, acrylonitrile, acrylamide, styrene,
Examples thereof include vinyl acetate, ethyl vinyl ether, butyl vinyl ether, alkyl methacrylate, hydroxyalkyl acrylate, alkoxyalkyl methacrylate, cyclohexyl acrylate, benzyl acrylate and furfuryl acrylate.

Further, a part of the component (a) and / or the component (b), specifically up to about 10% by weight, may be replaced with a diene monomer and copolymerized. Examples of such diene-based monomers include divinylbenzene, piperylene, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, methylbutadiene, cyclopentadiene, methylpentadiene, ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, Propylene glycol dimethacrylate etc. are mentioned.

Each of the above components is about 80-99.9 weight in total.
The remaining about 20 to 0.1% by weight is used to copolymerize a monoalkyl ester of maleic acid such as monomethyl, monoethyl, monoisopropyl, monobutyl and monooctyl.

Each of the above components can be copolymerized by any polymerization method, but a suspension polymerization method or an emulsion polymerization method is preferably used.

In the case of a carboxyl group-containing acrylic elastomer copolymerized with ethylene, the above-mentioned about 80-
99.9% by weight It is obtained by substituting about 30 to 80% by weight of the component used with ethylene for copolymerization.
This copolymerization reaction is performed by a pressure polymerization method.

A carboxyl group-containing acrylic elastomer obtained by copolymerizing a monoalkyl maleate as a carboxyl group-containing monomer gives an oil resistant hose whose physical properties are not deteriorated by steam vulcanizing it alone.
By steam vulcanizing this as a blend with a carboxyl group-containing acrylic elastomer copolymerized with ethylene (copolymerized with a monoalkyl maleate as a carboxyl group), an oil-resistant rubber that does not deteriorate in physical properties is obtained. can get. When used as a blend, the former is about 5 to 99% by weight and the latter is about
It is used in a proportion of 95 to 1% by weight.

Both of these rubber components can be crosslinked by using any vulcanizing agent, but a polyvalent amine compound is preferably used in order to achieve the object of the present invention. Examples of the polyvalent amine compound include hexamethylenediamine, hexamethylenediamine carbamate, tetramethylenepentamine,
4,4'-methylenedianiline, m-phenylenediamine, 4,
4'-diaminodiphenyl ether or the like is used in a ratio of about 0.1 to 10 parts by weight, preferably about 0.2 to 5 parts by weight, per 100 parts by weight of rubber. At a usage rate of less than this, vulcanization is insufficient and a vulcanizate having satisfactory tensile strength cannot be obtained,
On the other hand, if it is used at a ratio higher than this, the elongation of the vulcanizate is greatly reduced.

These polyvalent amine compounds are preferably used in combination with a vulcanization accelerator. As the vulcanization accelerator, for example, the following ones are used in a ratio of about 0.1 to 10 parts by weight, preferably about 0.5 to 5 parts by weight, per 100 parts by weight of rubber.・ Organic acids such as sodium stearate, potassium stearate, potassium oleate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, etc., alkali metal salts of inorganic acids, alkali metal hydroxides ・ Tetramethylammonium bromide, benzyl Quaternary ammonium salts such as triphenylphosphonium chloride, trimethyloctadecyl ammonium bromide, tetramethylphosphonium iodide, phosphonium salts-Tertiary amines such as triethylenediamine, imidazole, pyridine and quinoline-Diphenylguanidine, tetramethylguanidine, etc. Guanidines

The vulcanizable rubber composition is prepared by mixing the above-mentioned components with other known compounding agents such as a reinforcing agent, a filler, a stabilizer, a plasticizer and a lubricant, a roll mixing method, a Banbury mixing method, etc. It is carried out by mixing by a commonly used method. Its vulcanization is done by steam vulcanization.

[0018]

EFFECT OF THE INVENTION By steam vulcanizing a carboxyl group-containing acrylic elastomer or a blend of a carboxyl group-containing acrylic elastomer obtained by copolymerizing ethylene with this, an oil resistant hose with no deterioration in physical properties can be obtained, and roll processing is possible. The present invention also provides excellent moldability such as properties (non-adhesiveness to roll) and extrusion characteristics (non-adhesiveness immediately after extrusion).

[0019]

EXAMPLES The present invention will now be described with reference to examples.

[0020] Examples 1-2, Comparative Examples 1-3 acrylic elastomer comonomer (wt%) A B C Ethyl acrylate 46 46 n- butyl acrylate 20 20 methoxyethyl acrylate 30 30 maleic acid mono n- butyl 4 3 Allyl glycidyl ether 3 ethylene 55 methyl acrylate 42 A mixture of the above monomer compositions was copolymerized by a known method to obtain acrylic elastomers A, B and C.

To these acrylic elastomers, the required compounding agents shown in the following table were mixed and kneaded with an open roll mill under cooling to prepare a composition. This composition was subjected to press vulcanization and steam vulcanization to obtain normal physical properties (JIS K-6301) for these vulcanizates and compression set (JIS K-6301; 150 ° C, 70 hours) for the press vulcanizates. ,
25% compression) and oil resistance (JIS K-6301; JIS No. 3 oil, 150
The volume change rate at 70 ° C for 70 hours was measured. The obtained results, together with roll processability (8 inch open roll mill under cooling), extrusion characteristics (using a Toseki Seimitsu 25 mm diameter extruder) and steam vulcanization state (surface state of test piece),
It is shown in the following table. Press vulcanization: primary vulcanization in a mold at 160 ° C for 30 minutes and secondary vulcanization in an electric oven at 175 ° C for 2 hours Steam vulcanization: tested from composition in the mold 80 pieces
After preforming at 8 ° C for 8 minutes, primary vulcanization was performed in a steam oven at 160 ° C for 30 minutes and secondary vulcanization was performed in an electric oven at 175 ° C for 2 hours. Table Example Comparative Example 1 2 1 2 3 [Composition; parts by weight] Acrylic elastomer A 100 80 B 100 100 C 20 100 Stearic acid 1 1 1 1 1 Antiaging agent (# 445) 2 2 2 2 2 HAF carbon black 50 50 60 60 60 Methylenedianiline 1 1 1 Di-o-tolylguanidine 2 2 4 Dimethyldithiocarbamate Zn 2 Ammonium benzoate 2 [Press vulcanization] Hardness (JIS A) 67 66 69 69 73 100% modulus (kg / cm ² ) 47 34 40 46 40 Tensile strength (kg / cm ² ) 153 166 130 142 195 Elongation (%) 235 300 305 240 365 Compression set (%) 13 9 45 30 11 Oil resistance (%) 20 28 19 19 67 [Steam vulcanization] Hardness (JIS A) 64 63 61 57 65 100% modulus (kg / cm ² ) 50 39 33 26 39 Tensile strength (kg / cm ² ) 159 160 127 127 180 Elongation (%) 220 295 275 335 370 vulcanization Condition Foaming No No No No Yes No Deformation None None None Somewhat present [Roll processability] Non-adhesiveness to roll ○ ○ ○ ○ × [Extrusion characteristics] Non-adhesive immediately after extrusion ○ ○ ○ ○ × Anti-aging agent (# 445): 4,4'- Bis (α, α-dimethylbenzyl) diphenylamine

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29K 105: 24

Claims (2)

[Claims] 1. An oil resistant hose comprising a steam vulcanized product of a carboxyl group-containing acrylic elastomer obtained by copolymerizing a monoalkyl maleate as a carboxyl group-containing monomer. 2. A steam vulcanized product of a blend of a carboxyl group-containing acrylic elastomer copolymerized with a monoalkyl maleate as a carboxyl group-containing monomer and a carboxyl group-containing acrylic elastomer copolymerized with ethylene. Oil resistant hose.