JPH0733943A - Halogenated acrylic rubber composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which contains a halogenated acrylic rubber as the main component and a phenylamine compd. as an antioxidant and gives a vulcanizate excellent in heat resistance. CONSTITUTION:The compsn. contains a halogenated acrylic rubber, a phenylamine antioxidant, and calcium hydroxide or oxide.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a halogen-containing acrylic rubber composition. More specifically, it relates to a halogen-containing acrylic rubber composition having excellent heat resistance.

[0002]

2. Description of the Related Art In conventional acrylic rubber, the temperature range in which it is used is limited in terms of heat resistance and cold resistance, depending on the types of constituent monomers, especially crosslinking site monomers. . In the case of a halogen-containing acrylic rubber, both heat resistance and cold resistance are tentatively satisfied, and especially when a phenylamine-based compound is used as an antioxidant, the heat resistance of the rubber is evaluated as suppressing the increase in rubber hardness. Although satisfied with respect to the point, it is a fact that further improvement in heat resistance is required in relation to the intended use.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a composition containing a halogen-containing acrylic rubber as a main component and a phenylamine compound as an antiaging agent. It is about providing things that can give things.

[0004]

The object of the present invention is as follows.
This is achieved by a halogen-containing acrylic rubber composition containing a halogen-containing acrylic rubber, a phenylamine-based antioxidant and calcium hydroxide or calcium oxide.

As the halogen-containing acrylic rubber, alkyl acrylate, alkoxyalkyl acrylate,
At least one type of alkylthioalkyl acrylate, cyanoalkyl acrylate, etc. as a main component (about 60 to 99.
8% by weight), vinyl chloroacetate, allyl chloroacetate or glycidyl acrylate, glycidyl methacrylate, addition reaction products of monochloroacetic acid and the like glycidyl compound such as allyl glycidyl ester about 0.1-10 wt%, preferably about 10% by weight. A copolymer obtained by copolymerizing 1 to 5% by weight is used, and another vinyl compound can be copolymerized within the range of 30% by weight or less in the copolymer.

As the halogen-containing acrylic rubber, halogen- and carboxyl group-containing acrylic rubber,
For example, in the above halogen-containing acrylic rubber, acrylic acid, methacrylic acid, unsaturated monocarboxylic acid such as maleic acid or unsaturated dicarboxylic acid monoester such as mono-lower alkyl maleate is about 0.1 to 10% by weight, preferably about 1
What is copolymerized up to 5% by weight is used.

Examples of the phenylamine compound used as an antiaging agent include 4,4 '-(α, α-dimethylbenzyl) diphenylamine, octylated diphenylamine and phenyl-α-naphthylamine.
It is used in an amount of about 0.5 to 5 parts by weight, preferably about 1 to 2 parts by weight, per 100 parts by weight of the halogen-containing acrylic rubber. If the blending ratio is less than this range, the effect as an anti-aging agent will not be effectively exhibited, and if the blending amount is more than this range, the vulcanization will be hindered and the normal physical properties of the vulcanized rubber will be deteriorated.

In the present invention, in combination with such a phenylamine-based antioxidant, calcium hydroxide or calcium oxide is used as a halogen-containing acrylic rubber 100.
It is used in a ratio of about 0.1-5 parts by weight, preferably about 1-3 parts by weight. If the blending ratio is less than this range, the effect of further improving the heat resistance, which is the object of the present invention, cannot be obtained. On the other hand, if the mixing ratio is more than this range, the scorch stability is significantly impaired.

In the halogen-containing acrylic rubber composition containing the above-mentioned respective components as essential components, other necessary compounding ingredients are appropriately blended. Speaking of fillers and reinforcing agents, for example, when used as a vulcanization molding material for various sealing materials, carbon black is mainly compounded for applications such as O-rings and packings, and mainly used for applications such as oil seals. Soil, white carbon, etc. are mixed and used.
In addition, a vulcanizing agent, a vulcanization aid, a lubricant and the like are blended and used as necessary.

The composition is prepared by using a closed kneader such as a kneader or a Banbury mixer or an open kneader such as an open roll, and the vulcanization thereof is generally about 150-2.
It is performed by press vulcanization or injection molding vulcanization performed at 50 ° C for about 1 to 30 minutes, and if necessary, about 150 to 200
Oven vulcanization or steam vulcanization at ℃ for about 1 to 22 hours is performed as secondary vulcanization.

[0011]

EFFECTS OF THE INVENTION By adding calcium hydroxide or calcium oxide to a halogen-containing acrylic rubber composition containing a phenylamine-based antioxidant, heat resistance can be further improved. Such an effect is uniquely seen only in the calcium compound, and no hydroxide or oxide of another metal has such an effect.

[0012]

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

Example 1 100 parts by weight of an active halogen-containing acrylic rubber (Nippon Mectron product Knoxtite PA 404N) Stearic acid 1 FEF carbon black 5 Diatomaceous earth 65 White carbon 28 (Tokuyama Soda product Reorosil CP-102) Potassium stearate 0.25 Calcium stearate 3 Sulfur 0.3 Calcium hydroxide 1 4,4 '-(α, α-Dimethylbenzyl) diphenylamine 1 (Uniroy's product, Nowguard # 445) The above components were kneaded with an open roll and kept at 180 ° C for 8 minutes. After press vulcanization and secondary vulcanization at 175 ° C for 4 hours,
A test piece (22.5 × 12.5 × 2 mm) was prepared. For this test piece, while measuring the normal physical properties according to JIS K-6301,
A heat aging test was carried out to measure changes in normal state physical properties after 175 ° C.-70 hours, 150 hours and 300 hours. The degree of heat resistance is evaluated by the change in the physical property values, especially the change in hardness.

Example 2 In Example 1, the compounding amount of the phenylamine anti-aging agent (Nowguard # 445) was changed to 3 parts by weight.

Example 3 In Example 1, the compounding amount of the phenylamine anti-aging agent (Nowguard # 445) was changed to 5 parts by weight.

Comparative Example 1 In Example 1, no phenylamine type antioxidant (Naugard # 445) was used.

The measurement results in each of the above Examples and Comparative Examples are shown in Table 1 below. Table 1 Measurement items Actual-1 Actual-2 Actual-3 Ratio-1 [Normal physical properties] Hardness (JIS-A) 81 80 78 81 Tensile strength (MPa) 7.3 7.0 6.8 7.4 Elongation (%) 120 120 120 120 [ Heat aging test] After 175 ℃ -70 hours Hardness change (point) +4 +3 +3 +7 Tensile strength change rate (%) +24 +19 +15 +30 Elongation change rate (%) -16 -25 -18 -29 175 ℃ -150 hours hardness change (point) +6 +5 +4 +8 Tensile strength change rate (%) +23 +12 +3 +34 Elongation change rate (%) -21 -21 -12 -37 175 ℃ -300 hours hardness change (point) +10 +8 +8 +16 Tensile strength change rate (%) +24 +8 -1 +63 Elongation change rate (%) -53 -35 -30 -97

Example 4 Active Halogen-Containing Acrylic Rubber (Noxtite PA 404N) 100 Parts by Weight Stearic Acid 1 FEF Carbon Black 5 Diatomaceous Earth 65 White Carbon (Rheoroseal CP-102) 28 Potassium Stearate 0.25 Sodium Stearate 3 Sulfur 0.3 Calcium hydroxide 2 Phenylamine anti-aging agent (Naugard # 445) 3 Preparation, vulcanization and measurement of a composition using the above components were carried out in the same manner as in Example 1.

Comparative Example 2 In Example 4, calcium hydroxide was not used.

Comparative Examples 3 to 7 In Example 4, instead of calcium hydroxide, the same amounts of aluminum hydroxide (Comparative Example 3), magnesium hydroxide (Comparative Example 4) and barium hydroxide (Comparative Example 5) were used. Cupric hydroxide (Comparative Example 6) or lithium hydroxide (Comparative Example 7) was used. Comparative Examples 5 and 7 were poor in dispersion, and Comparative Example 6 was poor in vulcanization.

The measurement results in Example 4 and Comparative Examples 2 to 4 are shown in Table 2 below. Table 2 Measurement items Actual-4 ratio-2 ratio-3 ratio-4 [Normal physical properties] Hardness (JIS-A) 83 78 78 73 Tensile strength (MPa) 8.6 7.3 7.4 6.1 Elongation (%) 100 130 130 150 [ Heat aging test] After 175 ℃ -70 hours Hardness change (point) +1 +5 +5 +5 Tensile strength change rate (%) -5 +2 +9 +10 Elongation change rate (%) +1 -22 -23 -12 175 ℃ -150 hours hardness change (point) +1 +8 +8 +9 Tensile strength change rate (%) -14 -5 -1 +24 Elongation change rate (%) -7 -24 -34 -33 175 ℃ -300 hours hardness change (point) +5 +14 +11 +14 Tensile strength change rate (%) -21 +8 0 +33 Elongation change rate (%) -24 -58- 52 -50

Example 5 Active Halogen-Containing Acrylic Rubber (Noxtite PA 404N) 100 Parts by Weight Stearic Acid 1 FEF Carbon Black 5 Diatomaceous Earth 65 White Carbon (Rheoroseal CP-102) 28 Potassium Stearate 0.25 Sodium Stearate 3 Sulfur 0.3 Calcium oxide 2 Phenylamine anti-aging agent (Naugard # 445) 3 Preparation, vulcanization and measurement of a composition using the above components were carried out in the same manner as in Example 1.

Comparative Examples 8-10 In Example 5, instead of calcium oxide, the same amount of magnesium oxide (Comparative Example 8), zinc oxide (Comparative Example 9) or lead monoxide (Comparative Example 10) was used. It was

The measurement results of Example 5 and Comparative Examples 8 to 10 are shown in Table 3 below. Table 3 Measurement items Actual -5 ratio -8 ratio -9 ratio -10 [Normal physical properties] Hardness (JIS-A) 83 73 74 69 Tensile strength (MPa) 8.3 6.7 6.8 6.0 Elongation (%) 100 130 160 180 [ Heat aging test] After 175 ℃ -70 hours Hardness change (point) 0 +4 +11 +12 Tensile strength change rate (%) -8 +3 +32 +13 Elongation change rate (%) -5 0 -46 -58 175 ℃ -150 hours hardness change (point) +1 +11 +17 +15 Tensile strength change rate (%) -16 +19 +60 +3 Elongation change rate (%) -18 -25 -68 -64 175 ℃ -300 hours hardness change (point) +6 +15 +22 +21 Tensile strength change rate (%) -18 +36 +105 +9 Elongation change rate (%) -39 -48 -86 -80

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[Procedure amendment]

[Submission date] July 13, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

As the halogen-containing acrylic rubber, halogen- and carboxyl group-containing acrylic rubber,
For example, in the above halogen-containing acrylic rubber, an unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid, maleic acid or the like, or an unsaturated dicarboxylic acid monoester such as mono-lower-alkyl maleate is contained in an amount of about 0.1 to 10% by weight, preferably A copolymerized product of about 1 to 5% by weight is also used.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Example 1 100 parts by weight of active halogen-containing acrylic rubber (Nippon Mectron product Knoxtite PA 404N) Stearic acid 1 FEF carbon black 5 Diatomaceous earth 65 White carbon 28 (Tokuyama Soda product Reorosil CP-102) Potassium stearate 0 .25 Calcium stearate 3 Sulfur 0.3 Calcium hydroxide 1 4,4 '-(α, α-Dimethylbenzyl) diphenylamine 1 (Nuguard # 445 manufactured by Uniroyal Co., Ltd.) The above components were kneaded with an open roll and heated to 180 ° C. , 8
Press vulcanization for 1 minute and secondary vulcanization at 175 ° C. for 4 hours were performed to prepare a test piece ( 225 × 125 × 2 mm). The normal physical properties of this test piece were measured according to JIS K-6301, and after 175 ° C. for 70 hours,
A heat aging test was conducted to measure changes in normal state physical property values after 150 hours and 300 hours. The degree of heat resistance is
It is evaluated by the change in normal physical properties, especially the change in hardness.

Claims (1)

[Claims] 1. A halogen-containing acrylic rubber composition comprising a halogen-containing acrylic rubber, a phenylamine-based antioxidant and calcium hydroxide or calcium oxide.