U.S. patent application number 10/693686 was filed with the patent office on 2004-06-24 for acrylic elastomer composition.
Invention is credited to Okabe, Jun, Yoshida, Tamotsu.
Application Number | 20040122156 10/693686 |
Document ID | / |
Family ID | 15503501 |
Filed Date | 2004-06-24 |
United States Patent
Application |
20040122156 |
Kind Code |
A1 |
Yoshida, Tamotsu ; et
al. |
June 24, 2004 |
Acrylic elastomer composition
Abstract
An acrylic elastomer composition comprising (A) a
halogen-containing acrylic elastomer, (B) a polyvalent carboxylic
acid, (C) a quaternary onium salt and (D) a hydrotalcite can be
vulcanized within a shorter vulcanization time to give a
vulcanization product having distinguished normal state physical
properties and compression set characteristics, even without any
secondary vulcanization.
Inventors: |
Yoshida, Tamotsu;
(Kitaibaraki city, JP) ; Okabe, Jun; (Kitaibaraki
city, JP) |
Correspondence
Address: |
BUTZEL LONG
350 SOUTH MAIN STREET
SUITE 300
ANN ARBOR
MI
48104
US
|
Family ID: |
15503501 |
Appl. No.: |
10/693686 |
Filed: |
October 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10693686 |
Oct 24, 2003 |
|
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09277590 |
Mar 26, 1999 |
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Current U.S.
Class: |
524/448 |
Current CPC
Class: |
C08K 5/19 20130101; C08L
33/14 20130101; C08L 33/062 20130101; C08L 33/062 20130101; C08L
33/14 20130101; C08L 33/14 20130101; C08L 33/14 20130101; C08K
5/092 20130101; C08L 33/062 20130101; C08K 3/26 20130101; C08K 3/26
20130101; C08K 5/0025 20130101; C08K 5/19 20130101; C08K 5/092
20130101; C08K 3/26 20130101; C08K 5/0025 20130101; C08K 5/0025
20130101; C08K 5/092 20130101; C08L 25/18 20130101 |
Class at
Publication: |
524/448 |
International
Class: |
C08K 003/34 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 1998 |
JP |
150745/1998 |
Claims
What is claimed is:
1. An acrylic elastomer composition, which comprises (A) a
halogen-containing acrylic elastomer, (B) a polyvalent carboxylic
acid, (C) a quaternary onium salt and (D) a hydrotalcite.
2. An acrylic elastomer composition according to claim 1, wherein
the polyvalent carboxylic acid is an aliphatic polyvalent
carboxylic acid having 4 to 30 carbon atoms, alcyclic polyvalent
carboxylic acid, aromatic polyvalent carboxylic acid or anhydride
thereof.
3. An acrylic elastomer composition according to claim 1, wherein
the polyvalent carboxylic acid is used in an amount of 0.1 to 10
parts by weight on the basis of 100 parts by weight of the
halogen-containing acrylic elastomer.
4. An acrylic elastomer composition according to claim 1, wherein
the quaternary onium salt is used in an amount of 0.1 to 10 parts
by weight of the halogen-containing acrylic elastomer.
5. An acrylic elastomer composition according to claim 1, wherein
the hydrotalcite is used in an amount of 0.5 to 20 parts by weight
on the basis of 100 parts by weight of the halogen-containing
acrylic elastomer.
6. An acrylic elastomer composition according to claim 1, wherein a
higher fatty acid polyhydric alcohol ester or a higher aliphatic
amine is further contained as a lubricant.
7. An acrylic elastomer composition according to claim 6, wherein
the higher fatty acid polyhydric alcohol ester or the higher
aliphatic amine is used in an amount of 0.1 to 10 parts by weight
of the halogen-containing acrylic elastomer.
8. An acrylic elastomer composition according to claim 1, wherein
ureas are further contained as a vulcanization retardant.
9. An acrylic elastomer composition according to claim 8, wherein
the ureas are used in an amount of 0.1 to 10 parts by weight of the
halogen-containing acrylic elastomer.
10. A vulucanization molding product obtained by vulcanization
molding of an acrylic elastomer composition comprising (A) a
halogen-containing acrylic elastomer, (B) a polyvalent carboxylic
acid, (C) a quaternary onium salt and (D) a hydrotalcite without
any secondary vulcanization.
11. A vulcanization molding product according to claim 10, wherein
the acrylic elastomer composition further containing a higher fatty
acid polyhydric alcohol ester or a higher aliphatic amine as a
lubricant is used.
12. A vulcanization molding product according to claim 10, wherein
the acrylic elastomer composition further containing ureas as a
vulcanization retardant are used.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an acrylic elastomer
composition and more particularly to an acrylic elastomer
composition having distinguished vulcanization characteristics and
scorch stability.
[0003] 2. Description of Related Art
[0004] JP-A-50-132057 discloses a vulcanizable composition
comprising a halogen-containing acrylic elastomer, a polyfunctional
carboxylic add, a quaternary ammonium salt and a halide ion
acceptor, where it is stated that the halide ion acceptor includes
well known metal oxy compounds as add acceptors, such as alkali
metal salts or non-alkali metal salts of monocarboxylic add or
organophosphoric acid; oxides, hydroxides or carbonates of
non-alkali metals, metal; salts of inorganic acids; molecular
sieves, etc.
[0005] The polyfunctional carboxylic acid includes, so far as its
Examples are concerned, disodium azelate, dipotassium azelate,
disodium sebacate, disodium trimethyladipate,
bis(benzyltrimethylammonium)trimethyladipate, dipotassium
dodecenylsuccinate, disodium or dipotassium of high molecular
weight fatty add dimer, etc., all of which are used in the form of
disalt.
[0006] However, in case of using disodium azelate, both of the
resulting primary vulcanization product and the secondary
vulcanization product have considerably poor compression set
characteristics, as shown in the results of Comparative Example 6
mentioned below in contrast to Example 4 using azelaic add, and
furthermore much prolonged vulcanization time is required with poor
vulcanization characteristics. More particularly, secondary
vulcanization is indispensable due to the relatively low
crosslinking speed.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a
halogen-containing acrylic elastomer composition, which can be
vulcanized within a much shorter vulcanization time and can give
vulcanization products having distinguished normal state physical
properties and compression set characteristics even without any
secondary vulcanization.
[0008] The object of the present invention can be attained by an
acrylic elastomer composition, which comprises (A) a
halogen-containing acrylic elastomer, (B) a polyvalent carboxylic
acid, (C) a quaternary onium salt and (D) a hydrotalcite.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The halogen-containing acrylic elastomer for use as
Component (A) is copolymers of at least one of alkyl acrylate,
alkoxyalkyl acrylate, alkylthioalkyl acrylate, cyanoalkyl acrylate,
etc. as the main component (about 60 to 99.8% by weight),
copolymerized with about 0.1 to about 10% by weight, preferably
about 1 to about 5% by weight of (1) 2-chloroethyl vinyl ether,
2-chloroethyl acrylate or vinylbenzyl chloride, (2) vinyl
chloroacetate or allyl chloroacetate, (3) an addition reaction
product of a glycidyl compound such as glycidyl acrylate, glycidyl
methacrylate, allyl glycidyl ether, etc. and monochloroacetic acid,
or (4) a crosslinking site halogen-containing monomer such as
alkenyl ester of .alpha.- or .beta.-halogen-substituted aliphatic
monocarboxylic acid, haloalkyl ester of (meth)acrylic acid,
haloalkyl alkenyl ester, haloalkyl alkenyl ketone, or
haloacetoxyalkyl ester, haloacetyl group-containing unsaturated
compound, etc. The copolymers can be further copolymerized with not
more than about 30% by weight of other ordinary vinyl compound.
Furthermore, acrylic copolymers copolymerized with lactone-modified
acrylate (JP-A-63-264612) or terminal cyanolactone-modified
acrylate (JP-A-1-123809), or the like can be used.
[0010] Furthermore, the halogen-containing acrylic elastomer
includes halogen and carboxyl group-containing acrylic elastomers,
for example, the above-mentioned halogen-containing acrylic
elastomers copolymerized with about 0.1 to about 10% by weight,
preferably about 1 to about 5% by weight, of an unsaturated
monocarboxylic acid such as acrylic acid, methacrylic acid, maleic
acid, etc. or an unsaturated dicarboxylate monoester such as
mono-lower alkyl maleate, etc.
[0011] The polyvalent carboxylic acid for use as Component (13)
includes aliphatic polyvalent acids having 4 to 30 carbon atoms,
alicyclic polyvalent acids or aromatic polyvalent carboxylic acids.
Aliphatic dicarboxylic acids are preferable. Polyvalent carboxylic
acids can be used as acid anhydrides.
[0012] More particularly, the dicarboxylic acid includes saturated
aliphatic dicarboxylic acids such as succinic acid, glutaric acid,
adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic
acid, undecanedion acid, 1,10-decanedicarboxylic acid,
1,11-undecanedicarboxyli- c acid, 1,12-dodecanedicarboxylic acid,
1,14-tetradecanedicarboxylic acid, hexadecanedion acid,
.beta.,.beta.-dimethylsuccinic acid, .beta.,.beta.-dimethylglutaric
acid, .beta.-ethylglutaric acid, .alpha.-ethyladipic acid,
trimethyladipic acid, n-hexylsuccinic acid, n-octylsuccinic acid,
n-decylsuccinic acid, n-decenylsuccinic acid, n-tetradecylsuccinic
acid, n-octadecylsuccinic acid, isooctadecenylsuccinic acid,
n-eicosenylsuccinic acid, n-dodecenylsuccinic acid, etc.;
unsaturated aliphatic dicarboxylic acids such as maleic acid,
fumaric acid, etc.; alicyclic dicarboxylic acids such as
1,2-cyclohexanedicarboxylic acid, 1,3-cydohexanedicarboxylic acid,
1,4-cyclohexanedicarboxylic acid, phthalic acid etc.; and aromatic
dicarboxylic acids such as isophthalic acid, terephthalic acid,
etc.
[0013] About 0.1 to about 10 parts by weight, preferably about 0.1
to about 5 parts by weight, of the polyvalent carboxylic acid is
used on the basis of 100 parts by weight of the halogen-containing
acrylic elastomer. Below about 0.1 part by weight, physical
characteristics of the vulcanization products will be considerably
deteriorated due to unsatisfactory crosslinking, whereas above
about 10 parts by weight physical characteristics of the
vulcanization products will be also considerably deteriorated due
to the destroying of crosslinking sites of the elastomer by a
crosslinking agent in excess.
[0014] Quaternary onium salt as component (C) can be represented by
the following general formula, and quaternary phosphonium salts can
be preferably used:
(R.sub.1R.sub.2R.sub.3R.sub.4N).sup.+X.sup.- or
(R.sub.1R.sub.2R.sub.3R.su- b.4P).sup.+X.sup.-
[0015] where R.sub.1 to R.sub.4 are each an alkyl group having 1 to
25 carbon atoms, an alkoxy group, an aryl group, an alkylaryl
group, an aralkyl group or a polyoxyalkylene group, or two or three
of which may form a heterocyclic structure together with N or P;
and X is an anion such as Cl.sup.-, Br.sup.-, I.sup.-,
HSO.sub.4.sup.-, H.sub.2PO.sub.4.sup.-, RCOO.sup.-,
ROSO.sub.2.sup.-, RSO.sup.-, ROPO.sub.2H.sup.-, CO.sub.3.sup.-,
etc.
[0016] Specifically, it includes quaternary ammonium salts such as
tetrabutylammonium bromide, tetrabutylammonium chloride,
tetrabutylammonium iodide, tetraethylammonium bromide,
tetraethylammonium chloride, tetraethylammonium iodide,
n-dodecyltrimethylammonium bromide, octa-decyltrimethylammonium
bromide, trimethylbenzyl-ammonium bromide,
cetyldimethylbenzylammonium chloride, cetyl-pyridinium bromide,
cetyl-pyridinium sulfate, tetraethylammonium acetate,
trimethylbenzylammonium benzoate, trimethylbenzylammonium borate,
5-benzyl-1,5-diaza-bicyclo-[4,3,0]-5-nonenium chloride,
5-benzyl-1,5-diazabicyclo[4,3,0]-5-nonenium tetrafluoroborate,
etc.; quaternary phosphonium salts such as tetraphenylphosphonium
chloride, benzyl-triphenylphosphonium bromide,
benzyl-triphenylphosphonium chloride,
triphenylmethoxymethylphosphonium chloride,
triphenylmethylcarbonyl-methylphosphonium chloride,
triphenylethoxycarbonylmethylphosphonium chloride,
trioctylbenzylphosphonium chloride, trioctylmethylphosphonium
chloride, trioctylethylphosphonium acetate, tetraoctylphosphonium
chloride, trioctylethylphosphonium dimethylphosphate, etc.
[0017] About 0.1 to about 10 parts by weight, preferably about 0.1
to about 5 parts by weight, of the quaternary onium salt is used on
the basis of 100 parts by weight of the halogen-containig acrylic
elastomer. Below about 0.5 parts by weight the progress of
vulcanization will be considerably retarded, whereas above about 10
parts by weight the vulcanization rate is too much accelerated,
resulting in deterioration of scorch stability.
[0018] The hydrotalcite for use as Component (D) can be represented
by the following general formula:
Mg.sub.4.5.sub.2Al.sub.2(OH).sub.13CO.sub.3.multidot.3.5H.sub.2O
[0019] , and any one of synthetic hydrotalcites subjected to
surface treatment or not, removal of water of crystallization,
firing, etc. and those of natural origin such as products of
Russion Ural district, Norwegian Snarm district, etc. can be used.
Practically, commercially available products such as DHT-4A,
DHT-4A-2, KW-2000, etc. (all of which are trademarks of products
made by Kyowa Kagaku KK, Japan) can be used directly.
[0020] These hydrotalcites are inorganic anion exchangers, where
CO.sub.3 parts within the structure are substituted with halogen
ions, etc. to inactivate halogen. For example, in case of chlorine
ions, the reaction proceeds as follows:
Mg.sub.4.5Al.sub.2(OH).sub.13CO.sub.3.multidot.3.5H.sub.2O+2HCl.fwdarw.Mg.-
sub.4.5Al.sub.2(OH).sub.13Cl.sub.2.multidot.mH.sub.2O+CO.sub.2
[0021] the trapped chlorine is not released till about 450.degree.
C. or higher and thus can be normally kept completely inactive.
Metal oxides of ordinary use, for example, MgO, are formed into
MgCl.sub.2 upon trapping of hydrochloric acid, resulting in
deterioration of water resistance and metal corrosion, whereas the
hydrotalcite can prevent occurrence of such troubles. About 0.5 to
about 20 parts by weight, preferably about 1 to about 10 parts by
weight, of the hydrotalcite having such effects is used on the
basis of 100 parts by weight of the halogen-containing acrylic
elastomer. Below about 0.5 parts by weight vulcanization hardly
proceeds, whereas above about 20 parts by weight the vulcanization
rate is too much accelerated, resulting in deterioration of scorch
stability.
[0022] Besides the foregoing essential components, such additives
as a filler, a lubricant, a vulcanization retardant, a plasticizer,
an antioxidant, etc. can be used upon proper blending. Higher fatty
acids such as stearic acid, etc. are usually used as a lubricant,
but higher fatty acids inhibit crosslinking in the present
composition. Thus, polyhydric alcohol esters of higher fatty acids
or higher aliphatic amines are used as a lubricant in an amount of
about 0.1 to about 10 parts by weight, preferably about 0.1 to
about 5 parts by weight, on the basis of 100 parts by weight of the
halogen-containing acrylic elastomer.
[0023] Polyhydric alcohol esters of higher fatty acids for use in
the present invention include esters of higher fatty acids having 6
to 30 carbon atoms such as oleic acid, lauric acid, myristic acid,
palmitic acid, stearic acid, behenic acid, etc. and polyhydric
alcohols such as glycol, glycerine, pentaerythritol, etc. The
esters can be monoesters, diesters, triesters, tetraesters or
mixtures thereof.
[0024] The higher aliphatic amines for use in the present invention
include tertiary amines or secondary amines containing at least one
higher aliphatic group having 1 to 24 carbon atoms, for example,
tertiary amines such as dimethyloctyl-amine, dimethyldecylamine,
dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine,
dimethylstearylamine, dimethyloleylamine, dilaurylmonomethylamine,
trioctylamine, etc. and secondary amines such as dioctylamine,
didecylamine, dilaurylamine, dimyristylamine, dipalmityl-amine,
distearylamine, etc.
[0025] When about 0.1 to about 10 parts by weight, preferably about
0.1 to about 5 parts by weight, of ureas are further used as a
vulcanization retardant on the basis of 100 parts by weight of the
halogen-containing acrylic elastomer, much better scorch stability
can be obtained.
[0026] The ureas for this purpose include, besides urea and
thiourea, their substitution compounds such as N-methyl, N-ethyl,
N,N-dimethyl, N,N'-diethyl, N,N-diethyl, N,N'-ethylidene, N-acetyl,
N-methyl-N'-acetyl, N,N'-dimethylol, tetramethyl, carbamyl,
N-phenyl, N-benzyl, N-ethyl-N'-phenyl, N,N'-diphenyl, N,N-diphenyl,
N-benzoyl, tetraphenyl or
N,N-dimethyl-N,N'-dichlorophenyl-substituted compounds, and further
include carbamoylcarbamidic acid, ethyleneurea, glycolylurea,
dimethylparabanic acid, benzimidazolone, 5-methyluracil, etc.
[0027] The composition can be prepared by a tightly dosed mixer
such as a kneader, Banbury mixer, etc., or by an open mixer such as
an open roll, etc., and vulcanized by press vulcanization or
vulcanization molding using an injection molding machine at a
temperature of about 150.degree. to about 250.degree. C. for about
1 to about 30 minutes. If necessary, oven vulcanization or steam
vulcanization can be further carried out at a temperature of about
150.degree. to about 200.degree. C. for about 1 to about 22 hours
as secondary vulcanization.
[0028] In the prior art disclosed in the above-mentioned
JP-A-50-132057 practically using only polyvalent carboxylic acid
salt in spite of the statement of applicability of polyvalent
caroxylic acids, an acrylic elastomer composition capable of giving
distinguished vulcanization characteristics can be obtained in the
present invention by using polyvalent carboxylic acids per se.
Vulcanization products of the present acrylic elastomer composition
have also distinguished compression set characteristics.
[0029] By using a hydrotalcite in place of the halogen ion acceptor
used in the above-mentioned JP-A-50-132057, not only an acrylic
elastomer composition having a particularly distinguished
vulcanization rate can be obtained in the present invention, but
also vulcanization products of the present acrylic elastomer
composition have also distinguished heat resistant property and
compression set characteristics.
[0030] Furthermore, vulcanization products having good normal state
physical properties and compression set characteristics can be
obtained in the present invention without any secondary
vulcanization. That is, the vulcanization time can be largely
shortened. On the other hand, as is obvious from comparison of
Example 4 (use of azelaic acid) with Comparative Example 6 (use of
disodium azelate), compression set characteristics of Comparative
Example 6 are poor and thus the secondary vulcanization is
substantially indispensable. Furthermore, as is obvious from
comparison of Example 4 with Comparative Examples 1 to 5, the
vulcanization rate is more distinguished in the present invention,
even if the same azelaic acid is used in these cases, and there is
a remarkable difference particularly in the compression set
characteristics there between.
[0031] The present acrylic elastomer composition having these
distinguished characteristics can be effectively used as molding
materials for oil seals, O-rings, packings, gaskets, hoses,
etc.
PREFERRED EMBODIMENTS OF THE INVENTION
[0032] The present invention will be described in detail below,
referring to Examples and Comparative Examples, where parts are by
weight.
EXAMPLE 1
[0033] 100 parts of acrylic elastomer A consisting of an ethyl
acrylate-p-chloromethylstyrene copolymer (ratio by weight=98:2) was
admixed with the following components, kneaded by an open roll and
subjected to press vulcanization at 180.degree. C. for 8 minutes
and then to oven vulcanization (postcure) at 175.degree. C. for 4
hours:
1 Pentaerythritol fatty acid ester 2 parts (Emaster 430W, trademark
of a product made by Riken Vitamine K. K., Japan)
Dimethylstearylamine 1 part (Farmine DM80, trademark of a product
made by Kao Corp., Japan) 4,4'
-bis(.alpha.,.alpha.-dimethylbenzyl)diphenylamine 2 parts (Nocrac
CD, trademark of a product made by Ouchi-Shinko Kagaku K. K.,
Japan) FEF carbon black (N550) 50 parts Adipic acid 0.8 parts
Octadecyltrimethylammonium bromide 1 part Synthetic hydrotalcite 4
parts (DHT-4A-2, trademark of a product made by Kyowa Kagaku K. K.,
Japan)
[0034] The resulting kneading product and vulcanization product
were subjected to determination of the following
characteristics:
[0035] Vulcanization characteristics: tc10, tc90 and MH at
180.degree. C. by a curastometer
[0036] Mooney viscosity and scorch time (t.sub.s): 125.degree. C.
according to JIS K-6300
[0037] Vulcanization characteristics: according to JIS K-6301
[0038] Compression set: 150.degree. C. for 70 hours according to
JIS K-6301
[0039] Heat aging resistant property: changes in the normal state
physical properties by heating at 175.degree. C. after 70 hours
EXAMPLE 2
[0040] In Example 1, the same amount of acrylic elastomer B
consisting of an ethyl acrylate-n-butyl acrylate-2-methoxyethyl
acrylate-vinyl chloroacetate quaternary copolymer (ratio by
weight=48:25:25:2) was used in place of the acrylic elastomer A,
and the amount of FEF carbon black was changed to 60 parts.
EXAMPLE 3
[0041] In Example 1, the same amount of an acrylic elastomer C
consisting of an ethyl acrylate-n-butyl acrylate-2-methoxyethyl
acrylate-p-chloromethyl-styrene quaternary polymer (ratio by
weight=48:25:25:2) was used in place of the acrylic elastomer A,
and the amount of FEF carbon black was changed to 60 parts.
EXAMPLE 4
[0042] In Example 3, one part of azelaic acid was used in place of
0.8 parts of adipic acid.
EXAMPLE 5
[0043] In Example 3, 1.1 part of sebacic acid was used in place of
0.8 parts of adipic acid
EXAMPLE 6
[0044] In Example 3, the same amount of benzyltriphenylphosphonium
chloride was used in place of the octadecyltrimethylammonium
bromide.
EXAMPLE 7
[0045] In Example 3, 0.5 parts of diphenylurea was further
added.
EXAMPLE 8
[0046] In Example 3, 0.6 parts of succinic anhydride was used in
place of the adipic acid. Results of determination in the foregoing
Examples 1 to 8 are shown in the following Table 1.
2 TABLE 1 Example No. Item 1 2 3 4 5 6 7 8 [Vulcanization
characteristics] tc10 (min.) 0.4 0.42 0.4 0.4 0.4 0.6 0.6 0.7 tc90
(min.) 3.9 2 3.7 3.9 3.8 4.2 4.3 4.4 MH (Kg .multidot. cm) 8.2 9.8
9 9 9.1 8.9 8.8 8.2 [Mooney viscosity] Mooney viscosity ML.sub.MIN
46 53 50 51 51 50 47 47 [Scorch time] t.sub.5 (min.) 5.8 5 6.6 6.3
6.2 7.2 8.9 7.1 [Press vulcanization product] Hardness (JIS A) 63
59 66 67 68 65 65 65 100% Modulus (MPa) 5.4 4 7 7.1 7.4 6.8 6.5 6.8
Strength at break (MPa) 14.5 10.6 12.7 12.9 12.6 12.5 12.4 12.5
Elongation at break (%) 450 240 180 170 170 180 190 180 Compression
set (%) 26 20 24 20 21 32 28 25 [Heat aging resistant property of
press vulcanization product] Hardness change (pts) +6 +3 +4 +3 +3
+5 +5 +4 100% modulus change (%) +12 -1 +0 -1 -1 +8 +7 -1 Strength
at break -10 +0 -5 -4 -6 -3 +0 -5 change (%) Elongation at break +6
-6 -10 -6 -5 -12 -11 -6 change (%) [Oven vulcanization (postcured)
product] Hardness (JIS A) 65 60 67 68 68 66 66 66 100% modulus
(MPa) 5.9 4.3 7.3 7.4 7.5 7 7 7.1 Strength at break (MPa) 15.1 10.9
12.7 12.8 12.8 12.6 12.5 12.5 Elongation at break (%) 420 230 170
170 170 170 180 170 Compression set (%) 15 10 13 9 10 18 17 15
[Heat aging resistant property of oven vulcanization (postcured)
product] Hardness change (pts) +5 +1 +1 +1 +1 +3 +2 +1 100% modulus
change (%) +6 -4 -1 -4 -5 +0 -2 -3 Strength at break -10 +0 +1 +0
-5 -5 -3 -1 change (%) Elongation at break +6 -2 -6 +0 -2 -1 +0 -1
change (%)
COMPARATIVE EXAMPLE 1
[0047] The following components were mixed, vulcanized and
subjected to determination in the same manner as in Example 1:
3 Acrylic elastomer C 100 parts Stearic acid 1 part 4,4'
-bis(.alpha.,.alpha.-dimethylbenzyl)diphenylamine 2 parts FEF
carbon black 60 parts Azelaic acid 1 part Calcium oxide 1 part
Octadecyltrimethylammonium bromide 1 part
COMPARATIVE EXAMPLE 2
[0048] In Comparative Example 1, the same amount of calcium
hydroxide was used in place of the calcium oxide.
COMPARATIVE EXAMPLE 3
[0049] In Comparative Example 1, the same amount of magnesium oxide
was used in place of the calcium oxide.
COMPARATIVE EXAMPLE 4
[0050] In Comparative Example 1, the same amount of magnesium
hydroxide was used in place of the calcium oxide.
COMPARATIVE EXAMPLE 5
[0051] In Comparative Example 1, 4 parts of sodium stearate was
used in place of one part of calcium oxide.
COMPARATIVE EXAMPLE 6
[0052] In Comparative Example 1, the same amount of disodium
azelate was used in place of the azelaic acid and no calcium oxide
was used.
[0053] Results of determination in the foregoing Comparative
Examples 1 to 6 are shown in the following Table 2.
4 TABLE 2 Comp. Ex. No. Item 1 2 3 4 5 6 [Vulcanization
characteristics] tc10 (min.) 0.65 0.89 0.68 0.91 0.61 0.5 tc90
(min.) 8 7.91 8.26 8.1 2.75 3.38 MH (Kg .multidot. cm) 7.2 10.4 6.5
8.7 3.3 6.4 [Mooney viscosity] Mooney viscosity ML.sub.MIN 48 46 48
45 35 30 [Scorch time] t.sub.5 (min.) 5.4 5.2 4.7 4.4 5.2 5.6
[Press vulcanization product] Hardness (JIS A) 70 73 68 71 48 63
100% Modulus (MPa) 6.3 6.8 4.7 5.1 1.1 3.5 Strength at break (MPa)
11.6 11.7 11.8 11.9 4.2 10.9 Elongation at break (%) 210 160 240
180 460 230 Compression set (%) 80 73 85 79 72 44 [Heat aging
resistant property of press vulcanization product] Hardness change
(pts) +9 +5 +10 +6 +6 +6 100% modulus change (%) +79 +33 +87 +40 +8
+12 Strength at break change (%) +5 -9 +3 -2 -5 +1 Elongation at
break change (%) -38 -25 -42 -28 -10 -16 [Oven vulcanization
(postcured) product] Hardness (JIS A) 74 75 73 74 49 67 100%
modulus (MPa) 8 8.8 7 7.9 1.3 4.2 Strength at break (MPa) 12.6 13
11.9 12.5 4.6 11.1 Elongation at break (%) 150 140 150 150 430 200
Compression set (%) 43 44 42 43 68 32 [Heat aging resistant
property of oven vulcanization (postcured) product] Hardness change
(pts) +4 +3 +4 +4 +4 +3 100% modulus change (%) -1 -8 +3 +1 +4 -3
Strength at break change (%) -8 -11 -6 -8 -5 -2 Elongation at creak
change (%) -3 -7 +0 -4 -2 -6
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