JPH0539314A - Thermoplastic graft copolymer - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic graft copolymer which is melt-moldable and is useful as a thermoplastic elastomer exhibiting rubber elasticity by forming the copolymer so that its main chain comprises a polymer of a Tg of a specified temperature, and the side chain has a specified poly-p-phenylene structure. CONSTITUTION:The objective thermoplastic graft copolymer wherein the main chain comprises a polymer having a glass transition point Tg of 10 deg.C or below (e.g. acrylic ester polymer, PE, polychloroprene or styrene/butadiene copolymer), and the side chain has a poly-p-phenylene structure of the general formula (wherein (n) is 1-3 on average). This copolymer is melt-moldable, behaves like a rubber elastomer and is useful as a thermoplastic elastomer. It can be obtained, for example, by reacting a polymer having a Tg of 10 deg.C or below and having and/or being modified with reactive functional groups with a poly-p- phenylene compound having the functional groups of the polymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a graft copolymer which can be used as a thermoplastic elastomer.

[0002]

2. Description of the Related Art Thermoplastic elastomers (hereinafter sometimes abbreviated as TPE) currently used in industry are TPE composed of a block copolymer of a soft segment and a hard segment and a partially crosslinked rubber called an elastomer alloy. And TPE made of phase-separated plastic
It is roughly divided into.

As the former, a block copolymer called a polyester elastomer composed of an aliphatic polyether portion of polytetramethylene glycol and a polyester portion such as polyethylene terephthalate, an aliphatic polyether portion and polydodecanolactam, etc. There is known a block copolymer called a polyamide elastomer which is composed of the polyamide part. Furthermore, JP-A-2-110
No. 130 and Japanese Patent Application Laid-Open No. 3-97725 describe a block copolymer composed of a diol containing a terphenyl or quarterphenyl derivative, an aliphatic diol, and an aliphatic dicarboxylic acid.

As the latter, an elastomer alloy obtained by dynamically vulcanizing an alloy of polypropylene and an ethylene / propylene / diene terpolymer is known.

European Patent Publication No. 028723
No. 3 discloses that a copolymer having an aromatic polyester as a branch polymer, that is, a copolymer in which an aromatic polymer is covalently bonded to an acrylic resin or a polyester resin is used as a polymer solution for coating. The feature is that a film with high hardness can be formed. However, there is no suggestion in the specification regarding thermoplastic resin or TPE.

In recent years, various types of polymer ferroelectric liquid crystals having ferroelectric liquid crystal molecules in their side chains have been synthesized. Some of them have a para-phenylene skeleton as a ferroelectric liquid crystal molecule introduced into the side chain of a polymer, but all of them only describe the properties as a ferroelectric material, and the thermoplastic There is no suggestion regarding resin or TPE. The reason why they did not exhibit the performance as a thermoplastic resin or TPE is because the ferroelectric liquid crystal of the side chain is introduced into one molecule per monomer unit constituting the polymer, so that the property of the polymer of the main chain is almost eliminated. It is thought that this did not appear.

Furthermore, Shivaev et al., Polymer Communication (Polymer Co)
mmunication), 24, 364 pages (1
In 983), it is reported that an acrylate-based polymer having cyanobiphenyl as a mesogen group is used as a display / recording material. This utilizes the fact that the cyanobiphenyl group is a nematic liquid crystal and utilizes the irradiation of laser light to form a polydomain structure and scatter visible light. However, there is no suggestion regarding thermoplastic resins or TPE in these reports. Also in this system, one molecule of cyanobiphenyl unit was introduced per monomer unit constituting the acrylate polymer of the main chain, so the properties of the polymer of the main chain hardly appeared, so the properties as a thermoplastic resin or TPE were developed. It is thought that it did not exist.

[0008]

However, most of TPE, which is composed of a block copolymer of a soft segment and a hard segment, does not form a sufficient physical cross-linking point unless the hard segment is introduced in an amount of 10% or more. The reality is that only a relatively hard elastomer having a hardness of about 40 or more can be produced. Regarding ferroelectric liquid crystal polymers or acrylate polymers having a cyanobiphenyl group in the side chain, the flexibility of the main chain polymer is inherently reflected in the physical properties because the side chains have a high density. The reality is that there is none.

An object of the present invention is to provide a graft copolymer useful as a thermoplastic elastomer.

[0010]

[Means for Solving the Problems] In view of such circumstances,
As a result of earnest research, the present inventors have found a thermoplastic graft copolymer whose main chain is a polymer having a glass transition temperature of 10 ° C. or lower and whose side chain has a specific polyparaphenylene structure. The inventors have found that the graft copolymer has useful properties as a thermoplastic elastomer, and completed the present invention.

That is, the present invention provides a thermoplastic graft copolymer whose main chain is a polymer having a glass transition temperature of 10 ° C. or less and whose side chain has at least a polyparaphenylene structure represented by the general formula (2). It is about coalescence.

[0012]

[Chemical 2] (In the formula, n is a number average of 1 or more and 3 or less.)

The main chain (trunk polymer) constituting the graft copolymer of the present invention has a glass transition temperature of 10 ° C.
It is preferably 0 ° C or lower, particularly preferably -10 ° C or lower. This glass transition temperature is the differential scanning calorimeter (D
SC) is the second-order transition point at which an endotherm is observed at a heating rate of 10 ° C./min. When the glass transition temperature (hereinafter sometimes abbreviated as Tg) of the main chain polymer exceeds 10 ° C., the graft copolymer does not exhibit rubber elasticity in the operating temperature range of room temperature or higher, which is not preferable.

The T which constitutes the graft copolymer of the present invention.
As the main chain (trunk polymer) having g of 10 ° C. or less, acrylic acid ester polymer, homopolymer such as polyethylene, polypropylene, polybutadiene, polyisoprene, polychloroprene, and chlorosulfonated polyethylene, styrene-butadiene copolymer and water thereof. Additive, ethylene
Propylene copolymer, ethylene / propylene / diene copolymer, acrylonitrile / butadiene copolymer and hydrogenated product thereof, ethylene / acrylic acid ester copolymer,
Examples thereof include polyorganosiloxane and polyphosphazene.

Further, it is also possible to use a copolymer of the above-mentioned homopolymer or copolymer-constituting monomer and a copolymerizable monomer having an unsaturated double bond. However, in any copolymer, the copolymer composition must be controlled so that Tg is 10 ° C. or less.

The side chains constituting the graft copolymer of the present invention have at least a polyparaphenylene structure represented by the general formula 3.

[0017]

[Chemical 3] (In the formula, n is a number average of 1 or more and 3 or less.)

When n is less than 1, the melting point of the molecule does not rise, and the side chains of the resulting graft copolymer do not form sufficient physical cross-linking points to make it difficult to form a thermoplastic elastomer. If the temperature exceeds this value, the temperature at which the resulting graft copolymer can be melt-molded exceeds 400 ° C., and the moldability deteriorates, which is not preferable.

The method for producing the graft copolymer of the present invention includes a polymer having a reactive functional group and / or modified with a reactive functional group and having a glass transition temperature of 10 ° C. or less and a polymer at one end thereof. Examples thereof include a method of reacting a polyparaphenylene compound having a functional group capable of reacting with a functional group of a polymer.

The glass transition temperature used in the present invention is 1
Reactive functional groups in polymers at 0 ° C or lower include epoxy groups, amino groups, carboxyl groups, hydroxyl groups, thiol groups, isocyanate groups, halogens, alkylsilyl ether groups, silyl halide groups, acid anhydride groups, unsaturated double bonds. And the like.

The polyparaphenylene compound having a functional group at one end used as a side chain constituting the graft copolymer of the present invention has a melting point when it does not have a liquid crystal transition temperature, or a liquid crystal when it has a liquid crystal transition temperature. Transition temperature is 10
The temperature is 0 ° C or higher, preferably 150 ° C or higher, more preferably 170 ° C or higher. Further, the melting point or liquid crystal transition temperature is 400 ° C. or lower, preferably 350 ° C. or lower, and more preferably 300 ° C. or lower. When the melting point or liquid crystal transition temperature of the polyparaphenylene compound is lower than 100 ° C., the temperature range showing rubber elasticity in the obtained graft copolymer is narrowed, which is not preferable.
When it is higher, the resulting graft copolymer is difficult to melt-mold, which is not preferable.

The polyparaphenylene compound having a functional group at one end, which is reacted with the polymer, used in the present invention is represented by the general formula 4.

[Chemical 4]

Here, n is a number average of 1 or more and 3 or less.
F is a reactive functional group, which is selected according to the functional group of the polymer to be reacted, but is a carboxyl group, hydroxyl group, acetoxy group, epoxy group, thiol group, halogen, alkylsilyl ether group, silyl halide group. , An acid anhydride group, a group having an unsaturated double bond, and the like.

The reactive functional group is a carboxyl group,
A hydroxyl group and an acetoxy group are more preferable.

As a polyparaphenylene compound having a carboxyl group as a reactive functional group at one end, 4-biphenylcarboxylic acid (melting point = about 225 ° C.) is preferably used.

As the polyparaphenylene compound having a hydroxyl group as a reactive functional group at one end, p-phenylphenol is preferably used. Furthermore, examples of the polyparaphenylene compound having an acetoxy group as a reactive functional group at one end include 4-acetoxybiphenyl, which is easily obtained by acetylating the hydroxyl group of p-phenylphenol described above with acetic anhydride.

In the general formula 4, a compound having a hydroxyl group as a functional group and having n = 2 can be synthesized according to the method described in JP-A-2-311525, and a compound having n = 3 is It can be synthesized according to the method described in JP-A-3-311524. Further, these hydroxyl groups can be easily modified into acetoxy groups by acetylating with acetic anhydride as in the above.

The combination of the reactive functional group of the main chain and the functional group of the side chain capable of reacting with the reactive functional group of the main chain can be appropriately selected within the range not impairing the object of the present invention.

Specifically, for example, as a method for producing the thermoplastic graft copolymer of the present invention, a polymer having a functional group capable of reacting with a carboxyl group at a glass transition temperature of 10 ° C. or lower, a melting point or a liquid crystal transition temperature is used. Is 100 ° C
Above, a method of reacting with a polyparaphenylene compound having a carboxyl group at one end can be mentioned.

Further, there is a method in which a polymer having a functional group capable of reacting with a hydroxyl group and having a glass transition temperature of 10 ° C. or lower is reacted with a polyparaphenylene compound having a melting point or a liquid crystal transition temperature of 100 ° C. or higher and having a hydroxyl group at one end. Can be mentioned.

Examples of the functional group capable of reacting with the hydroxyl group and the carboxyl group include an epoxy group and an isocyanate group. An epoxy group is particularly preferable.

Examples of such epoxy group-containing polymers include methyl acrylate / glycidyl methacrylate copolymer, ethyl acrylate / glycidyl methacrylate copolymer, propyl acrylate / glycidyl methacrylate copolymer, butyl acrylate / glycidyl methacrylate copolymer. Examples thereof include coalesce, hexyl acrylate / glycidyl methacrylate copolymer, dodecyl acrylate / glycidyl methacrylate copolymer and the like.

Further, methyl acrylate / glycidyl styrene copolymer, ethyl acrylate / glycidyl styrene copolymer, propyl acrylate / glycidyl styrene copolymer, butyl acrylate / glycidyl styrene copolymer, hexyl acrylate / glycidyl styrene copolymer, Examples thereof include dodecyl acrylate / glycidyl styrene copolymer.

Furthermore, methyl acrylate.N- (4-
(2,3-Epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, ethyl acrylate
N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, propyl acrylate / N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer Polymer, butyl acrylate / N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, hexyl acrylate / N- (4-
(2,3-Epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, dodecyl acrylate.N- (4- (2,3-epoxypropoxy) -3,5
Examples thereof include dimethylbenzyl) acrylamide copolymer.

Further, acrylonitrile-butadiene-
Glycidyl methacrylate copolymer, acrylonitrile / butadiene / glycidyl styrene copolymer, acrylonitrile / butadiene / N- (4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl) acrylamide copolymer, ethylene / vinyl acetate -Glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl styrene copolymer, ethylene-vinyl acetate-N- (4
Examples include-(2,3-epoxypropoxy) -3,5-dimethylbenzyl) acrylamide copolymer. Furthermore, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl methacrylate copolymer, ethylene / propyl acrylate / glycidyl methacrylate copolymer, ethylene / butyl acrylate / glycidyl methacrylate copolymer, ethylene / hexyl acrylate / Examples thereof include glycidyl methacrylate copolymer and ethylene / dodecyl acrylate / glycidyl methacrylate copolymer.

Further, ethylene / methyl acrylate /
Glycidyl styrene copolymer, ethylene / ethyl acrylate / glycidyl styrene copolymer, ethylene / propyl acrylate / glycidyl styrene copolymer, ethylene / butyl acrylate / glycidyl styrene copolymer, ethylene / hexyl acrylate / glycidyl styrene copolymer, Examples thereof include ethylene / dodecyl acrylate / glycidyl styrene copolymers.

Furthermore, ethylene methyl acrylate
N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, ethylene
Ethyl acrylate / N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, ethylene / propyl acrylate / N- (4
-(2,3-Epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, ethylene / butyl acrylate / N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer , Ethylene hexyl acrylate N- (4-
(2,3-Epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, ethylene / dodecyl acrylate / N- (4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer, etc. Is mentioned.

Further, styrene / butadiene / glycidyl methacrylate copolymer, styrene / butadiene / glycidyl styrene copolymer, styrene / butadiene / N
Examples thereof include various copolymers such as-(4- (2,3-epoxypropoxy) -3,5 dimethylbenzyl) acrylamide copolymer.

These various copolymers can be usually obtained by well-known radical polymerization. Moreover, the polyorganosiloxane which has an epoxy group and / or a glycidyl group in a side chain can be mentioned.

The double bond of a polymer having a double bond is epoxidized by a known method, for example, the method described in US Pat. No. 3,155,638, and the polymer is used as the main chain of the present invention. be able to.

For example, a method of reacting a toluene solution of an ethylene / propylene / diene monomer terpolymer (hereinafter sometimes abbreviated as EPDM) with a peracid such as metachloroperbenzoic acid can be mentioned.

The glycidyl group can be introduced into the polymer having a double bond by various methods. For example, polymerization of a monomer having a double bond and a glycidyl group such as glycidyl methacrylate or allyl glycidyl ether or glycidyl acrylate in the presence of EPDM in a suitable organic solvent, or butyl acrylate,
A glycidyl group can be introduced into a side chain by copolymerization with a monomer copolymerizable with the above monomer.

The specific reaction method is not particularly limited, but a method of reacting by melt kneading is preferred.

In this melt-kneading, the polymer and the polyparaphenylene compound having a Tg of 10 ° C. or lower at a temperature not lower than the melting point or liquid crystal transition temperature of the polyparaphenylene compound having a reactive functional group at one end are usually used. It can be performed using a kneader. As a kneading machine, a Banbury mixer,
Any device such as a single-screw extruder, a twin-screw extruder, a roll, or a kneader that can apply a shearing force at high temperature may be used.

The reaction temperature is preferably at least the melting point or liquid crystal transition temperature of the paraphenylene compound used, and is preferably not more than the thermal decomposition temperature of the polymer having Tg of 10 ° C. or less. When the reaction temperature is lower than the melting point or liquid crystal transition temperature of the polyparaphenylene compound used,
It is not preferable because the functional group of the polyparaphenylene compound and the polymer having Tg of 10 ° C. or less do not easily react, and it is difficult to obtain the target graft copolymer, and thermal decomposition of the polymer having Tg of 10 ° C. or less is not possible. If the temperature is exceeded, the polymer is remarkably decomposed during the kneading reaction and the molecular weight is lowered, which is not preferable.

In order to accelerate the graft reaction, it is preferable that the reaction temperature is high and the reaction time is long within the above temperature range. Further, in the reaction in which the epoxy group participates in the reaction, it is preferable to add a catalyst such as a phosphine compound or a tertiary amine in order to accelerate the graft reaction.

The thermoplastic graft copolymer of the present invention can be used as a thermoplastic elastomer exhibiting rubber elasticity at the glass transition temperature or higher of the main chain polymer used. The graft copolymer is a polymer having a Tg of 10 ° C. or lower and / or a branch polymer of the graft copolymer, which is the same as or different from the graft copolymer and the trunk polymer constituting the graft copolymer. In the mixture with the same compound, it shows the property as a thermoplastic elastomer.

However, in any case, the polymer having Tg of 10 ° C. or less is 50% by weight or more and 99% by weight or less, preferably 65% by weight or more and 97% by weight or less of the total polymer. Polymers with Tg of 10 ° C or less are 50% of all polymers
If it is less than 100% by weight, the resulting graft copolymer tends not to exhibit rubber elasticity in the temperature range of room temperature or higher, which is not preferable, and if it exceeds 99% by weight, physical crosslinking points formed by the side chain polyparaphenylene compound are reduced. Even at room temperature, it is not preferable because it causes remarkable plastic deformation.

Further, the graft copolymer, which is the thermoplastic elastomer of the present invention, includes carbon black, silica, calcium carbonate, mica, diatomaceous earth, zinc white, basic magnesium carbonate, aluminum silicate, titanium dioxide, talc, as appropriate. Fillers such as glass fiber, plasticizers, antioxidants, colorants, ultraviolet absorbers, flame retardants, oil resistance improvers,
An anti-scorch agent, a tackifier, etc. can be arbitrarily mixed and used.

[0050]

The thermoplastic graft copolymer of the present invention is
Melt molding is possible, and it behaves as a rubber elastic body and is extremely useful as a thermoplastic elastomer.

[0051]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

The measurement conditions for each physical property are as follows. Tensile test ... Using a tensile tester Tensilon EM-500 manufactured by Toyo Baldwin Co., Ltd., measurement was performed according to ASTM D-638. Compression set test: A constant strain compression tester manufactured by Toyo Seiki Seisaku-sho, Ltd. was used for measurement according to JIS K-6301. The conditions were 25 ° C. and 22 hours. Shore A hardness: It was measured according to ASTM D-2240 using a Shore hardness meter manufactured by Toyo Seiki Seisakusho. The sample thickness is 4.2 mm and the interval is 15
The measurement was performed in seconds. Melt index: Measured with a melt indexer manufactured by Toyo Seiki Seisakusho under conditions of 260 ° C. and 10 kg load.

Examples 1 and 2 An ethylene / methyl acrylate / glycidyl methacrylate terpolymer (ethylene / methyl acrylate / glycidyl methacrylate = 38) was used according to the method described in Example 5 of JP-A-61-127709. .7 / 59
/2.3 (weight ratio), 190 ° C., and MI = 8.7 g / 10 minutes at 2.16 kg load) were obtained. The glass transition temperature of this polymer was measured with a stand-alone type differential scanning calorimeter DSC-50 type manufactured by Shimadzu Corporation in a nitrogen atmosphere at a temperature rising rate of 10 ° C./min.

From the obtained diagram, the endothermic onset temperature was determined by the tangential method according to the conventional method and used as the glass transition temperature. The glass transition temperature was -31.5 ° C. The heating loss curve of this polymer was measured with a stand-alone thermogravimetric analyzer TGA-50 manufactured by Shimadzu Corporation in a nitrogen atmosphere at a temperature rising rate of 10 ° C./min. By this measurement, this polymer is 3
It was found that there was no weight loss up to around 50 ° C. and it was thermally stable.

This polymer and 4-biphenylcarboxylic acid (melting point = about 225, which is a primary reagent manufactured by Wako Pure Chemical Industries, Ltd.
(° C) with the composition shown in Table 1 and equipped with a Toyo Seiki Seisakusho Labo Plastomill 20R-20 type R-60 type mixer and a roller type blade as a blade, and melt-kneading reaction at 260 ° C and 100 rpm for 8 minutes. Then, a graft copolymer was obtained.

Table 1 shows the MIs of the various graft copolymers thus obtained under the conditions of 260 ° C. and a load of 10 kg. Furthermore, a 120 mm × 120 mm × 2.1 mm press sheet was prepared from the obtained graft copolymer at 280 ° C., and test pieces for measuring various physical properties were cut from the press sheet to measure the physical properties. The results are shown in Table 1.

Comparative Example 1 The ethylene / methyl acrylate / glycidyl methacrylate terpolymer used in Example 1 was melt-kneaded alone under the same conditions as in Example 1, and various physical properties were evaluated in the same manner as in Example 1. went. The results are shown in Table 1.

Comparative Examples 2 and 3 Ethylene / methyl acrylate / glycidyl methacrylate terpolymer used in Example 1 and benzoic acid as a special grade reagent manufactured by Wako Pure Chemical Industries, Ltd. were used at the reaction temperatures shown in Table 1. Was melt-kneaded under the same conditions as in Example 1 except that the temperature was set to 220 ° C., and various physical properties were evaluated in the same manner as in Example 1.
The results are shown in Table 1.

[0059]

[Table 1]

However, due to the limitation of the measuring device, the elongation is 140
Since it can be measured only up to 0%, if the elongation does not break even when reaching 1400%, in the column of breaking elongation, ">
1400 "and the elongation is 1400% in the breaking strength column.
The strength at is described.

Claims (1)

[Claims] 1. A thermoplastic graft copolymer whose main chain is a polymer having a glass transition temperature of 10 ° C. or lower and whose side chain has at least a polyparaphenylene structure represented by the general formula 1. [Chemical 1] (In the formula, n is a number average of 1 or more and 3 or less.)