JPH03115337A - Elastomer composition - Google Patents

Abstract

PURPOSE:To prepare an elastomer compsn. giving a molded product excellent in the resistance to heat, oil, and chemicals, and mechanical strengths and useful for an electric wire cover, belt, automobile part, tube, tire, etc., by compounding a vulcanizable rubber component and an aliph. polyester in a specified ratio. CONSTITUTION:The title compsn. is prepd, by compounding 5-85wt.% vulcanizable rubber component (e.g. styrene-butadiene rubber) and 95-15wt.% aliph. polyester comprising an aliph. dicarboxylic acid of formula I (wherein n is 0-10) (e.g. oxalic acid), an aliph. diol (e.g. ethylene glycol), and a dihydroxyl compd. of formula II (wherein R<1> and R<2> are each alkylene; p is 3 or 4; and q ard r are each 0, 1 or higher) (e.g. pref. 4,4''-dihydroxy-p-terphenyl) and/or a monohydroxyl compd. of formula III (wherein R<3> is alkylene; l is 2 or 3; and m is 0, 1 or higher) (e.g. 4-hydroxy-p-terphenyl).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to electric wire coatings, belts, automobile parts, tubes,
Used in elastic materials such as tires and industrial products. The present invention relates to an elastomer composition formed by mixing a vulcanizable rubber component and an aliphatic polyester.

(Prior Art) Natural rubber and synthetic rubber have excellent flexibility and elasticity, and are used as a variety of industrial materials. However, these rubber materials have a mechanical strength of 5.

Its range of use is limited due to poor heat resistance, oil resistance, chemical resistance, etc. Against this background, it is desired to develop an industrial material that maintains the flexibility and elasticity of rubber and has excellent heat resistance, mechanical strength, oil resistance, and chemical resistance.

Various remedies have been proposed to address these problems.

As a typical method, a method has been proposed in which various reinforcing agents, fillers, and stabilizers are added to various rubbers, but this method is only a partial improvement of the above-mentioned physical properties. The composition could not be obtained.

It has also been proposed to incorporate other polymers into rubber. For example, in JP-A-60-31545.

An elastomer composition in which a polyester elastomer having a crystalline aromatic polyester segment and a polylactone segment is blended with rubber has been proposed. This elastomer composition is heat resistant.

Weather resistance and oil resistance are improved, but mechanical strength is lower.

In particular, the improvement in tensile elongation at break was insufficient.

(Problems to be Solved by the Invention) The present invention has been made to solve these problems, and its purpose is to:

1 by blending rubber and a polyester elastomer having crystalline aromatic polyester segments.
In addition to the flexibility and elasticity of rubber, it also has heat resistance,
Oil Resistance 1 An object of the present invention is to provide an elastomer composition with excellent chemical resistance and mechanical strength.

(Means for Solving the Problems) The inventors of the present invention have conducted intensive research on polyester elastomers to be blended into rubber.

The present invention was completed by discovering an aliphatic polyester that has elastomer properties, excellent heat resistance and mechanical properties, and excellent moldability, and blending this with rubber.

That is, 1 the elastomer composition of the present invention has 1, (A
) 5 to 85% by weight of a vulcanizable rubber component; (B) an aliphatic dicarboxylic acid, an aliphatic diol whose general formula is represented by the following formula (1), and a dihydroxy compound whose general formula is represented by the following formula (II) and 95 to 15% by weight of an aliphatic polyester containing at least one of the monohydroxy compounds represented by the following formula [III];
This achieves the above objective.

HOOC-(CHz)n-COO)I [I](
During the ceremony.

represents an integer from 0 to 10.

) (In the formula, +R'+R" independently represents an alkylene group, p is 3 or 4, and (br independently represents O or an integer of 1 or more.) (In the formula, R3 is an alkylene group. group, 1 is 2 or 3, and 5m is an integer of 0 or 1 or more.) [Aliphatic polyester] Among the aliphatic dicarboxylic acids, if a dicarboxylic acid having more than IO carbon atoms is used, the aliphatic polyester The physical properties of the molded product obtained from this process deteriorate.

Examples of the dicarboxylic acid include oxalic acid.

Malonic acid, succinic acid, glutaric acid, adipic acid.

Speric acid and sepathic acid are preferably used.

Examples of the aliphatic diols include glycols and polyalkylene oxides. The above-mentioned glycols include 1, for example, ethylene glycol propylene glycol,
trimethylene glycol 1,4-butanediol, 1.
3-butanediol, 1,5bentanediol, II6
-hexanediol, 1.7 butanediol, l, 8
-octanediol, 1,9-nonanediol, 1
．． Examples include 10-decanediol, cyclopentane-1,2-diol, cyclohexane-1,2diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclohexane-1,4 dimetatool, etc. They may be used alone or in combination of two or more.

Examples of the above-mentioned polyalkylene oxide include 1.

Polyethylene oxide, polypropylene oxide.

Examples include polytetramethylene oxide, polyhexamethylene oxide, etc., and these may be used alone.
Two or more types may be used in combination. If the number average molecular weight of the polyalkylene oxide becomes small, the ability to impart flexibility to the aliphatic polyester produced will decrease, and if it becomes too large, the physical properties such as thermal stability of the obtained aliphatic polyester will decrease. -20,000 is preferable, and 5 is more preferably 500-5,000.

The dihydroxy compound represented by the above formula (II) is a low molecular compound that exhibits liquid crystallinity, and has alkylene groups R1, RZ
is preferably an ethylene group or a propylene group, and q and r are preferably O or 1, and 4,4''-
Dihydroxy-p-terphenyl.

4,4111-dihydroxy-loquaterphenyl represented by the following formula CB) and 4°4° represented by the following formula (C)
Di(2-hydroxyethoxy Lp-quaterphenyl) and the like are preferably used.

4. The transition temperature of 4°°-dihydroxy-p-terphenyl (A) from the crystalline state to the liquid crystalline state is 260°C.

4.4””-dihydroxy-p-quarterphenyl [
B] is 336°C, and that of 4,4""-di(2-hydroxyethoxyLp-quaterphenyl (C) is 403°C.The liquid crystal state is a state in which the compound is in a molten state, It also refers to a state in which molecules maintain an oriented state. Each of the above dihydroxy compounds (II) may be used alone or in combination.

Liquid crystal molecules generally have high crystallinity, and as mentioned above, 4
．． 4''-dihydroxy-p-terphenyl [A].

4.4”゛-dihydroxy-p-quarterphenyl (
B) and 4.4””-di(2-hydroxyethoxy Lp
-Quarterphenyl CC) has a high transition point from crystal to liquid crystal state, so these dihydroxy compounds (
II) is incorporated into the polymer chain.

The polymer exhibits unique properties.

That is, dihydroxy compound (II) exhibits crystallinity,
Moreover, since its transition point is high, dihydroxy compounds (I
Even when the amount of I) is small, strong physical crosslinks with high heat resistance are formed. the result.

It is presumed that a thermoplastic elastomer with high heat resistance can be obtained without impairing the flexibility derived from the soft segment.

The monohydroxy compound represented by the above formula (I[) is.

They are rigid, low-molecular-weight compounds that have a paraphenylene skeleton, and their melting points are extremely high, reflecting their unique molecular structure. Furthermore, the paraphenylene skeleton is known to be effective as a mesogen for low-molecular liquid crystal compounds, and this is because the skeleton has a strong cohesive force not only in the solid state but also in the high temperature state (molten state). This shows that. Therefore, the above monohydroxy compound [
III] is incorporated at the end of the polymer, it results in very strong and highly heat-resistant physical crosslinking, producing a thermoplastic elastomer with excellent heat resistance.

In the monohydroxy compound represented by the above formula [III], R3 is preferably an ethylene group or a propylene group, and m is preferably O or 1. Examples of the monohydroxy compounds include 9, 4-hydroxy-p-terphenyl, 4-hydroxy-p-quarterphenyl, 4
-(2-hydroxyethoxy)-p-terphenyl,
Examples include 4-(2-hydroxyethoxy)-p-quarterphenyl. The monohydroxy compound CI) is
Each may be used alone or in combination.

An aliphatic polyester consisting of at least one of the above aliphatic dicarboxylic acid [I], an aliphatic diol, a dihydroxy compound (n), and 1 monohydroxy compound (I [[]), a polysilicone having two hydroxyl groups, , lactone, and aromatic hydroxycarboxylic acid may be contained as constituent components.

The above-mentioned lactones open the ring and react with acids and hydroxyl groups to add aliphatic chains, giving flexibility to the polyester, and those having 4 or more carbon atoms in the ring. Preferably, a 5- to 8-membered ring is preferred, and examples include ε-caprolactone, δ-valerolactone,
Examples include T-butyrolactone.

The above-mentioned aromatic hydroxycarboxylic acids impart rigidity and liquid crystallinity to polyester, and include salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, and 3-chloro-4-hydroxybenzoic acid.

3-bromo-4-hydroxybenzoic acid, 3-methoxy-
4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, 2-
Examples include 24-hydroxy-4'carboxybiphenyl hydroxy-6-naphthoic acid, preferably parahydroxybenzoic acid, 2-hydroxy-6-naphthoic acid,
4-hydroxy-4"-carboxybiphenyl.

Furthermore, a dihydroxy compound (
Aromatic diols and aromatic dicarboxylic acids other than 11) may be contained as constituent components.

The aromatic diol mentioned above is hydroquinone.

Resorcinol, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4.4'
-dihydroxybiphenyl, 4,4゜dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 4,4''-dihydroxybenzophenone, 4
．． 4'-dihydroxydiphenylmethane, bisphenol A, 1,1-di(4-hydroxyphenyl)cyclohexane, 1,2-bis(4-hydroxyphenoxy)ethane, 1,4-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, etc. can give.

Examples of the aromatic dicarboxylic acids include metal salts of terephthalic acid, isophthalic acid, and 5-sulfoisophthalic acid; 4.4
'-dicarboxybiphenyl, 4.4'-dicarboxydiphenyl ether, 4.4'-dicarboxydiphenyl sulfide, 4.4"-dicarboxydiphenyl sulfone, 3,3°-dicarboxybenzophenone,
4.4'-dicarboxybenzophenone.

1.2-bis(4-carboxyphenoxy)ethane.

Examples include 1,4-dicarboxynaphthalene and 2,6-dicarboxynaphthalene.

The aliphatic polyester made of the dihydroxy compound [11], an aliphatic diol, and an aliphatic dicarboxylic acid has a content of the dihydroxy compound (II).

If the content is too low, the heat resistance will decrease, and if it is too high, the elastic modulus will increase and the flexibility will decrease, making it unsuitable for use as a thermoplastic elastomer. 0.1 inside
~30 mol% is preferable, more preferably 0.5~20
It is mol%, more preferably 1.0 to 10 mol%. In addition, when polyalkylene oxide or polysilicone is used as a diol other than aromatic, the constituent unit thereof is counted as one monomer. That is, one polyethylene oxide having a degree of polymerization of 10 is counted as 10 monomers.

In addition, the heat resistance of the aliphatic polyester composed of the monohydroxy compound (I[[), aliphatic diol, and aliphatic dicarboxylic acid] decreases when the content of the monohydroxy compound [III] decreases; molecular weight did not increase sufficiently.

Since the physical properties are inferior, it is preferable to set the amount to 0.1 to 20 mol% of the total monomers constituting the aliphatic polyester. Further, the aliphatic polyester consisting of the dihydroxy compound (ff), monohydroxy compound (I[r), aliphatic diol, and aliphatic dicarboxylic acid] is a dihydroxy compound (II) and monohydroxy compound [III].
If the combined content of hydroxy compounds decreases, the heat resistance will decrease, and if it increases, the flexibility will decrease and a sufficient increase in molecular weight will not be obtained. It is preferable to set it as mol%.

At this time, the ratio of dihydroxy compound (II) and monohydroxy compound (I) is o< [III]/ CI + [III] <2/
A range satisfying 3 is preferable.

The aliphatic polyester consisting of the above components is
It can be produced using any of the generally known polycondensation methods listed below.

■ A method of directly reacting a dicarboxylic acid with a diol component (including aliphatic diols, dihydroxy compounds, monohydroxy compounds, etc.).

■A method in which lower esters of dicarboxylic acids and diol components are reacted using transesterification.

■A method in which a dicarboxylic acid halide and a diol component are reacted in a suitable solvent such as pyridine.

■A method in which a metal alcoholade, which is a diol component, is reacted with a dicarboxylic acid halide.

■A method of reacting an acetylated diol component with a dicarboxylic acid using transesterification.

It is also possible to control the structure of the resulting polyester by changing the order of addition of the dihydroxy compound [I[) during one polymerization. For example, dihydroxy compounds (
When II) is added together with the dicarboxylic acid and other diol components, a random copolymer is easily obtained, and when dihydroxy compound (II) is added in the late stage of polymerization, a block copolymer is easily obtained. (In addition, the above dihydroxy compound (II) is added to the pre-synthesized polyester.
Alternatively, the acetyl compound of the dihydroxy compound is kneaded under reduced pressure and heat, and the dihydroxy compound (II) is added to the molecular chain by removal of ethylene glycol or transesterification reaction.
It is also possible to introduce segments based on

When performing polycondensation, catalysts that are generally used in producing polyester may be used.

This catalyst includes lithium, sodium, potassium,
Cesium, magnesium, calcium, barium, strontium, zinc, aluminum.

titanium cobalt germanium, tin, lead, antimony,
Arsenic, cerium, boron, cadmium.

Metals such as manganese, their organometallic compounds, organic acid salts,
Examples include metal alkoxides and metal oxides.

Particularly preferred catalysts include calcium acetate, diacyl stannous, tetraacyl stannous, dibutyltin oxide, dibutyltin dilaurate, dimethyltin maleate, tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyl titanate, germanium dioxide,
and antimony trioxide. Two or more of these catalysts may be used in combination. It also efficiently distills water, alcohol, glycol, etc. that are produced as a by-product during polymerization.

In order to obtain a high molecular weight polymer, it is preferable to reduce the pressure of one reaction system to 1 mn+Hg or less in the late stage of polymerization. The reaction temperature is generally between iso and 350°C.

[Vulcanizable rubber component]

The vulcanizable rubber components include natural rubber and synthetic rubber. As the synthetic rubber, most commercially available synthetic rubbers can be used. For example, styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR),
Examples include isobutylene-isoprene rubber (IIR), urethane rubber, polysulfide rubber, and the like. These vulcanizable rubber components may be partially vulcanized.

The elastomer composition of the present invention is obtained by blending and mixing these vulcanizable rubber components and the above aliphatic polyester in a predetermined ratio. The vulcanizable rubber component is used in an amount of 10 to 85% by weight based on the elastomer composition. 10
If it is less than 85% by weight, the resulting composition will lack rubber-like elasticity, and if it exceeds 85% by weight, the oil resistance, heat resistance, and chemical resistance of the elastomer composition will decrease.

The vulcanizable rubber component and the aliphatic polyester can be mixed by various methods, such as a roll kneader, a Banbury mixer 1 extruder, a plastograph, or the like.

Further, in order to vulcanize the vulcanizable rubber component contained in the elastomer composition of the present invention, a specific vulcanizing agent, vulcanization accelerator, etc. can be used. Vulcanizing agents include sulfur compounds such as powdered sulfur and colloidal sulfur;
and p-quinone dioxime, cumene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide.

There are peroxides such as 1.4-bis(1-butylperoxyisopropyl)benzene. These vulcanizing agents.

It is preferably used in an amount of 0.1 to 5% by weight based on the vulcanizable rubber component. Vulcanization accelerators include n-butyraldehyaniline, 1,3-diphenylguanidine, and N,N'-diphenylthiourea. Furthermore, a wire accelerator, a scorch inhibitor, a tackifier 1 processing aid, carbon black, etc. may be blended.

Furthermore, the following additives may be added to the elastomer composition of the present invention within a range that does not impair practicality. Examples of additives include inorganic fibers such as glass fibers, carbon fibers, boron fibers, silicon carbide fibers, alumina fibers, amorphous fibers, silicon/titanium/carbon fibers, and organic fibers such as aramid fibers.

Inorganic fillers such as calcium carbonate, titanium oxide, mica, and talc, triphenyl phosphite, trilauryl phosphite, trisnonylphenyl phosphite, 2-
tert-butyl-α-(3-tert-butyl-4-
Heat stabilizers such as hydroxyphenyl)-p-cumenylbis(nonylphenyl)phosphite.

Flame retardants such as hexabromocyclododecane, tris-(2,3-dichloropropyl)phosphate pentabromophenyl allyl ether, p-tert-butylphenyl salicylate 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy- UV absorbers such as 2"-carboxybenzophenone and 2,4.5-trihydroxybutyrophenone, butylhydroxyanisole, butylhydroxytoluene, distearylthiodipropionate, dilaurylthiodipropionate
Antioxidants such as hindered phenolic antioxidants,
Antistatic agents such as N,N-bis(hydroxyethyl)alkylamines, alkylarylsulfonates, and alkylsulfanates; inorganic substances such as barium sulfate, alumina, and silicon oxide; sodium stearate, barium stearate, and sodium valmitate; Higher fatty acid salts; organic compounds such as benzyl alcohol and benzophenone;
Examples include crystallization promoters such as highly crystallized polyethylene terephthalate and polytrans-cyclohexane dimetatool terephthalate.

(Example) The present invention will be described below based on nine examples.

Synthesis of aliphatic polyester (B): Dimethyl adipate 2
68.2 g, 313.6 g of ethylene glycol and 60.9 g of 4.4111-dihydroxy-p-quarterphenyl (hereinafter referred to as DHQ), and 0.4 g of calcium acetate and 0.13 g of germanium oxide as catalysts. I put it in. After purging the inside of the flask with nitrogen, the temperature was raised to 180°C to perform a transesterification reaction. Methanol was distilled out along with the reaction. It takes about 2 hours for the transesterification reaction to complete, during which time 8! Continued stirring. Next.

The temperature inside this flask was raised to 300°C, and in that state
After stirring for 0 minutes, ethylene glycol was distilled out and the reaction mixture became homogeneous. A polycondensation reaction was carried out for 2 hours while the pressure inside this flask was reduced to 11IiHg or less. A very viscous white resin was obtained. The intrinsic viscosity of this resin is 1.
It was 0.

The aliphatic polyester (B) obtained above and the commercially available S
BR rubber (JSR5BR1500, made by Japan Synthetic Rubber)
(A) in a weight ratio of 5:5, and melted the mixture at 200°C for 30 minutes using a plastograph.

To the resulting mixture, 1.75% by weight of sulfur as a vulcanizing agent based on the rubber component and 0.5% by weight of 1,3-diphenylguanidine as a vulcanization accelerator based on the rubber component were added, ioo 'c for 15 minutes to obtain an elastomer composition. Next, the obtained elastomer composition was press-vulcanized at 145° C. for 35 minutes using a pressure press to obtain a molded article. In addition, JSIi 5BR1500.

Bonded styrene 23.5%, Mooney viscosity 52 L1,
(100'c > later.

The following evaluation tests were conducted on the obtained molded body.

(a) Tensile elongation test Measured according to JIS K6301 using a No. 3 dumbbell. The tensile tester is Shimadzu Autograph AG500.
0B was used.

(b) Oil resistance test The molded body was immersed in JIS Nα3 oil at 70'C for 70 hours.

The volume change rate (%) of the molded body after immersion with respect to before the test was measured.

(C) Chemical resistance test No. 3 Danher was exposed to benzene, toluene, and 20% Na
3 after being immersed in OH aqueous solution at 23”C for 5 days.
No. Danher was taken out from each method and its surface condition was observed. Chemical resistance was classified into ranks A to D based on changes in surface condition. The results are shown in Table 2.

As the vulcanizable rubber component of Example 1, commercially available NBR rubber (
JSRNBI'l N240. Made by Japanese synthetic rubber) (
A molded article of an elastomer composition was obtained in the same manner as in Example 1 except that A) was used. Evaluation tests were conducted on the obtained molded body in the same manner as in Example 1.

The results are shown in Tables 1 and 2. In addition, JSRNBI
? N240 is 26% bound acrylonitrile, Mooney viscosity 56 ML+, 4 (100°C), specific gravity 0.96
belongs to.

Comparative Examples 1 and 2 are the rubber components used in Examples 1 and 2, namely SBR rubber (JSRSBR1500, manufactured by Japan Synthetic Rubber) (A) and NBR rubber (JSRNBRN2).
Example 1 for only 40゜Japanese Synthetic Rubber (A)
A molded body was obtained by performing the same vulcanization operation. Evaluation tests were conducted on this molded article in the same manner as in Example 1. The results are shown in Tables 1 and 2.

(Margin below) In the table, A: No change in surface condition, B
: There is almost no change in the surface condition. C: The surface is slightly swollen. D: Becomes brittle due to swelling. means.

As can be seen from Table 1, the molded articles (Examples 1 and 2) obtained from the elastomer composition of the present invention in which the rubber component (8) and the aliphatic polyester (B) are mixed are molded articles made only of the rubber component. The tensile elongation at break and the oil resistance are superior to those of Comparative Examples 1 and 2. Furthermore, as can be seen from Table 2, the molded bodies obtained from the elastomer compositions of the present invention (Examples 1 and 2) showed no surface condition when exposed to any of the solvents benzene, toluene, and 20% NaOH aqueous solution. Almost no change was observed, and the oil resistance was superior to molded products made only of rubber components (Comparative Examples 1 and 2).

(Effect of the invention) The elastomer composition of the present invention is as described above.

Since it contains the vulcanizable rubber component (A) and the aliphatic polyester (B) into which segments are introduced (based on dihydroxy compounds and monohydroxy compounds with high crystallinity and high melting point), it can be used as an elastomer. A molded product having high performance and excellent heat resistance, oil resistance, chemical resistance, and mechanical strength can be obtained, and is suitably used for wire-coated belts, automobile parts, tubes, tires, and various industrial products.

that's all

Claims (1)

[Scope of Claims] 1. (A) 5 to 85% by weight of a vulcanizable rubber component; (B) an aliphatic dicarboxylic acid whose general formula is represented by the following formula [I];
95 to 15% by weight of an aliphatic polyester comprising an aliphatic diol and at least one of a dihydroxy compound whose general formula is represented by the following formula [II] and a monohydroxy compound represented by the following formula [III]; An elastomer composition containing; HOOC-(CH_2)n-COOH[I] (in the formula,
n represents an integer of 0 to 10. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] (In the formula, R^1 and R^2 independently represent an alkylene group, p is 3 or 4, and q and r are independently 0 or 1
Indicates an integer greater than or equal to ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼[III] (In the formula, R^3 represents an alkylene group, and l is 2 or 3.
and m represents an integer of 0 or 1 or more. )