JPS62938B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to thermoplastic elastomers. More specifically, it is made of crosslinked rubber and polyolefin resin obtained by dynamically heat-treating a specific ethylene/α-olefin copolymer rubber with a crosslinking agent, and is particularly suitable for extrusion molding or injection molding of large thick products. The present invention relates to a thermoplastic elastomer suitable for. When injection molding ordinary rubber, it is necessary to mix additives with the rubber, knead it, feed it into a mold, and then vulcanize it, which requires a special molding machine, takes a long cycle time, and requires a long process. The problem was that it was complicated. Similar problems exist in extrusion molding, which has become a bottleneck in the mass production of rubber products. Therefore, alternatives to rubber are being considered using materials that can be molded without vulcanization and have properties similar to rubber.
Among materials with such performance, soft plastics such as soft vinyl chloride resin, ethylene, vinyl acetate copolymer, and low-density polyethylene have the advantages of good moldability and high flexibility. On the other hand, its uses are severely limited due to drawbacks such as poor heat resistance and rebound resilience. Attempts have been made to improve heat resistance and mechanical strength by mixing soft plastics with plastics with high melting points, such as high-density polyethylene or polypropylene, but this results in a loss of flexibility and makes it difficult to mold thick products. If this happens, sink marks may occur and a good product cannot be obtained. Therefore, recently, so-called thermoplastic elastomers have begun to attract attention as having performance intermediate between vulcanized rubber and soft plastics. Olefin-based thermoplastic elastomers are already known, and their main components are, for example, graft copolymers of polyethylene and butyl rubber, or ethylene-propylene copolymer rubbers such as ethylene-propylene copolymer rubber and ethylene-propylene-polyene copolymer rubber. Several things have been proposed. As one of such olefin-based thermoplastic elastomers, a composition consisting of polyolefin-based plastic and partially crosslinked rubber was also disclosed in the Japanese Patent Publication Publication No. 53.
This method is known from Japanese Patent Publication No. 21021 and Japanese Patent Publication No. 34210/1983, and particularly discloses a partially crosslinked rubber of ethylene-propylene-polyene copolymer rubber as a crosslinked rubber. However, although the thermoplastic elastomer has excellent performance, the present inventors have found that although this thermoplastic elastomer has excellent performance, it is not possible to use ethylene-propylene copolymer rubber such as ordinary ethylene-propylene copolymer rubber or ethylene-propylene-polyene copolymer rubber as a crosslinked rubber. I learned that as long as rubber is used, it is insufficient for injection molding of large, thick-walled products. In other words, when manufacturing large, thick products such as bumper guards, side shields, overriders, side moldings, and bumper protectors by injection molding, it is necessary to obtain products that do not cause flow marks or sink marks and have an excellent glossy appearance. , it is necessary to improve the fluidity of thermoplastic elastomers. For this purpose, the present inventors learned that it was necessary to incorporate a moldability improver such as a softener and polyisobutylene into the thermoplastic elastomer, and
No. 53-149240 and JP-A-53-145857 proposed a method for producing a thermoplastic elastomer composition with improved moldability. These problems included problems such as deformation of thick products due to their own weight, problems with contamination due to the blended softener seeping onto the product surface, and furthermore, problems with increased production costs for thermoplastic elastomers due to the addition of expensive polyisobutylene. The present inventors have also found that these problems cannot be solved no matter how the formulation is changed as long as a general crosslinked rubber of ethylene-propylene copolymer rubber is used as the crosslinked rubber. Therefore, the present invention relates to a thermoplastic elastomer which has been further improved, and its purpose is to be able to manufacture large, thick products with good moldability by injection molding, and to be able to avoid deformation due to its own weight. Another purpose is to provide a high-strength thermoplastic elastomer that has good processability without adding a softener or a moldability improver such as polyisobutylene. The goal is to provide the following. Therefore, the present inventor has developed a thermoplastic elastomer consisting of a polyolefin resin and a crosslinked rubber of an ethylene/α-olefin copolymer rubber, and the type of α-olefin in the ethylene/α-olefin copolymer rubber; The composition ratio of α-olefin and α-olefin has a significant influence on the properties of the thermoplastic elastomer. A thermoplastic elastomer consisting of a crosslinked rubber and a polyolefin resin obtained by dynamically heat-treating an ethylene/α-olefin copolymer rubber in an extremely narrow range of 20 to 95/5 with a crosslinking agent is The present inventors have discovered that the thermoplastic elastomer is significantly stronger than a thermoplastic elastomer made of a crosslinked propylene copolymer rubber and a polyolefin resin, and has rubber-like properties. That is, according to the present invention, it consists of an ethylene unit and an α-olefin unit having 4 to 10 carbon atoms,
An ethylene/α-olefin copolymer rubber R having a molar ratio of 80/20 to 95/5 and an intrinsic viscosity [η] of 0.6 to 6 dl/g (ethylene/α-olefin) is dynamically mixed with a crosslinking agent. The crosslinked rubber obtained by heat treatment is composed of the polyolefin resin P, and the weight ratio (R/P) of the ethylene/α-olefin copolymer rubber R and the polyolefin resin P is 90/
A thermoplastic elastomer is provided which is characterized in that it is 10 to 50/50. Advantages of the invention are as described below.
First, since the thermoplastic elastomer of the present invention has high strength, the tensile stress at break can be increased to 100 kg/cm ³ or more even if a moldability improver is added, so large thick products can be injected with good moldability. It can be molded and there is no need to worry about deformation due to its own weight. Of course, it maintains sufficient flexibility and repellency, and has a flow mark,
No sink marks occur and the appearance of the product surface is excellent. In addition, by incorporating a small amount of fluidity improver, although the moldability is slightly impaired, it is possible to make a thermoplastic elastomer with extremely high strength, which is suitable for manufacturing products where appearance is not a particular issue. be. Furthermore, by using the copolymer rubber of the present invention having a relatively low molecular weight with an intrinsic viscosity [η] of 0.6 to 3.0 dl/g, the thermoplastic elastomer of the present invention can be used satisfactorily without adding a moldability improver. Since it maintains good fluidity and has high strength, it can be injection molded into large, thick products with good moldability, and the products do not have the problem of deformation due to their own weight. Therefore, a high-strength thermoplastic elastomer without contaminating the surface of the product can be obtained at low cost. Of course, the specific ethylene/α-olefin copolymer rubber of the present invention itself can be easily produced by a method for producing ordinary ethylene/propylene copolymer rubber, and is therefore inexpensive. The configuration of the present invention will be explained in detail below. In the present invention, the use of a specific ethylene/α-olefin copolymer rubber R in the process of dynamic heat treatment with a crosslinking agent is the most important structural requirement, and in order to achieve the effects of the present invention. This is the main point.
The α-olefin which is a component of this specific ethylene/α-olefin copolymer rubber R is an α-olefin having 4 to 10 carbon atoms. Specific examples include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and mixtures thereof, with 1-butene being particularly preferred. And the ratio of ethylene units to α-olefin units (ethylene/α-olefin) is
80/20 to 95/5, preferably 85/15 to
Examples include 95/5, more preferably 85/15 to 93/7. This copolymer rubber R preferably contains a polyene component, and the amount thereof is preferably from 4 to 50, more preferably from 8 to 40, expressed as an iodine value. A polyene component is necessary when a sulfur type compound is used as a crosslinking agent. Polyene components include 1.4-hexadiene and 1.6
- Chain nonconjugated dienes such as octadiene, 2-methyl-1.5-hexadiene, 6-methyl-1.5-heptadiene, 7-methyl-1.6-octadiene, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene , 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene, -2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2.3- Diisopropylidene-5-norbornene, 2-ethylidene-3
Typical examples include trienes such as -isopropylidene-5-norbornene, 2-propenyl-2.2-norbornadiene, 1.3.7-octatriene, and 1.4.9-decatriene. Suitable polyenes are cyclic non-conjugated dienes and 1,4-hexadiene, especially dicyclopentadiene or 5-
It is ethylidene-2-norbornene. In addition, the intrinsic viscosity [η] of the copolymer rubber R is 0.6 to 6.0 dl/
g, preferably from 0.6 to 5.0. [η] is 0.6
If it is less than dl/g, the strength of the thermoplastic elastomer will be low, and if it is more than 6.0 dl/g, the moldability of the thermoplastic elastomer will deteriorate, so they are excluded from the present invention. The specific ethylene/α-olefin copolymer rubber R of the present invention is produced by a conventional method for producing ethylene/propylene copolymer rubber. That is, it is produced by using a Ziegler catalyst such as a soluble vanadium compound and an organoaluminum compound in a medium, and supplying ethylene, α-olefin, polyene if necessary, and hydrogen gas as a molecular weight regulator. Examples of the medium include pentane, hexane, heptane,
Octane, aliphatic hydrocarbons such as kerosene, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene, carbon tetrachloride, tetrachloroethylene,
Halogenated hydrocarbons such as trichlorethylene, ethyl chloride, methylene chloride, and dichloroethane can be used alone or in combination. Examples of soluble vanadium compounds include vanadium tetrachloride, vanadyl trichloride, vanadium triacetylacetonate, vanadyl diacetylacetonate, vanadyl trialkoxide VO
(OR) ₃ (here, R represents an aliphatic hydrocarbon group),
Halogenated vanadyl alkoxide VO (OR) _o X ₃
- _o (where R is an aliphatic hydrocarbon group, X is a halogen atom, and 0<n<3), etc. can be used alone or in combination. On the other hand, as an organoaluminum compound, the general formula R _n
Compounds represented by AlX ₃ - _n (where R is an aliphatic hydrocarbon group, X is a halogen, and 1≦m≦3) such as triethylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethyl Aluminum dichloride and the like can be used alone or in combination. Preferred examples of the crosslinking agent include sulfur-based compounds and organic peroxides, and the use of organic peroxides is more preferred. Specifically, organic peroxides include dicumyl peroxide, di-tert-butyl peroxide,
2.5-dimethyl-2.5-di-(tert-butylperoxy)hexane, 2.5-dimethyl-2.5-di(tert-butylperoxy)hexane,
-butylperoxy)hexane-3,1.3-bis(tert-butylperoxyisopropyl)benzene, 1.1-bis(tert-butylperoxy)-
3.3.5-trimethylcyclohexane, n-butyl-4.4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2.4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butylberbenzoate, tert -Butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide,
Examples include tert-butylcumyl peroxide. Among these, 2.5-dimethyl-2.5-di(tert-butylperoxy)hexane, 2.5-dimethyl-2.5-
di(tert-butylperoxy)hexane-3,
1.3-bis(tert-butylperoxyisopropyl)benzene, 1.1-bis(tert-butylperoxy)-3.3.5-trimethylcyclohexane and n-butyl-4.4-bis(tert-butylperoxy)valerate are preferred, especially 1.3-bis(tert-butylperoxyisopropyl)benzene. (tert-butylperoxyisopropyl)benzene is most preferred. Such organic peroxide is used in an amount of 3 x 10 ^-4 to 1 x 10 -2 mol, preferably 5 x 10 ^-4 to 1 x 10 ^-2 mol, per 100 parts by weight of the copolymer rubber R used in the process of dynamically heat-treating the crosslinked rubber. It is blended in an amount of 5 x 10 ^-3 mol, more preferably 1 x 10 ^-3 to 3 x 10 ^-3 mol. If it is less than 3 x 10 ^-4 mol, the degree of crosslinking of the crosslinked rubber produced during the heat treatment process will be too small, resulting in the thermoplastic elastomer not having sufficient rubber properties such as heat-resistant tensile properties, elastic recovery, and impact resilience; 1
When the amount exceeds ×10 ^-2 mol, the degree of crosslinking of the crosslinked rubber increases, resulting in a decrease in fluidity of the thermoplastic elastomer and deterioration in moldability. When organic peroxides are used as crosslinking agents in the heat treatment process, sulfur, p-quinonedioxime, p,p'-dibenzoylquinoneoxime, N-methyl-N,4-dinitrosoaniline,
Nitrobenzene, diphenylguanidine, trimethylolpropane-N,N'-m-phenylene dimaleimide, divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, Crosslinking aids such as allyl methacrylate, vinyl butyrate or vinyl stearate can be included. Due to the presence of such a crosslinking aid, a uniform and mild crosslinking reaction can be expected during the heat treatment process. Among these crosslinking aids, divinylbenzene is easy to handle, and is also useful for copolymer rubber R, which is the main component present in the heat treatment process, and in some cases, for polyolefin resin P, which is present in the heat treatment process. It has good compatibility with organic peroxides, has an organic peroxide solubilizing effect, and acts as a dispersion aid for peroxides, so a thermoplastic elastomer with a homogeneous crosslinking effect during heat treatment and a well-balanced fluidity and physical properties can be obtained. Most preferred. In the present invention, the amount of such a crosslinking aid is 0.1 parts by weight per 100 parts by weight of the total amount of the compound in the heat treatment process.
A range of from 2% to 2% by weight, particularly from 0.3% to 1% by weight is preferred; if the amount exceeds 2% by weight, the crosslinking reaction progresses, resulting in poor fluidity of the thermoplastic elastomer. On the other hand, if the amount of organic peroxide blended is small, it will exist in the thermoplastic elastomer as an unreacted monomer, and the physical properties may change due to the thermal history during processing and molding of the thermoplastic elastomer, so excessive blending should be avoided. It is. In the present invention, in order to promote the decomposition of organic peroxides, tertiary amines such as triethylamine, tributylamine, 2.4.6-tris(dimethylamino)phenol, aluminum, cobalt,
Organometallic carboxylates such as naphthenates and octanoates of vanadium, copper, calcium, zirconium, manganese, magnesium, lead, mercury, etc. can also be blended in the heat treatment process. Examples of the sulfur-based compound as a crosslinking agent include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dimethyldithiocarbamate. Such a sulfur-based compound is used in an amount of 0.05 to 20 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of copolymer rubber R used in the heat treatment process, for the same reason as when organic peroxide is used as a crosslinking agent.
Add 1.0 part by weight. When a sulfur-based compound is used as a crosslinking agent, a vulcanization accelerator used in ordinary rubber compounding may be added during the heat treatment process. As a vulcanization accelerator, N-cyclohexyl-2
-Benzothiazole-sulfenamide, N-oxydiethylene-2-benzothiazole-sulfenamide, N,N-diisopropyl-2-benzothiazole sulfenamide, 2-mercaptobenzothiazole, 2-(2.4-dinitrophenyl)mercaptobenzothiazole, 2 -(2.6-
Thiazole series such as diethyl-4-morpholinothio)benzothiazole and dibenzothiazirudisulfide; guanidine series such as diphenylguanidine, triphenylguanidine, diorthotolylguanidine, orthotolyl biguanide, diphenylguanidine, and phthalate; Aldehyde amines or aldehyde-ammonia systems such as acetaldehyde aniline reactants, butyraldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde ammonia; imidazolines such as 2-mercaptoimidazoline; thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthio Thiourea series such as urea and diorthotolylthiourea; thiurams such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, and pentamethylenethiuram tetrasulfide system;
Zinc dimethyldithiocarbamate, zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate,
Examples include dithioate salts such as zinc dimethyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, and tellurium diethyldithiocarbamate; xanthate series such as zinc dibutylxanthate, and zinc white. These vulcanization accelerators are copolymer rubber
It is used in a proportion of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of R. The crosslinking agent and dynamic heat treatment process of the present invention refers to the ethylene/α-olefin copolymer rubber R of the present invention, a crosslinking agent, and optionally a crosslinking aid or vulcanization accelerator.
The melt-kneading equipment for melt-kneading the polyolefin-based resin P in some cases includes an open-type mixing roll, a closed-type Banbury mixer, an extruder, a kneader, a continuous mixer, etc. can be used. Among these, it is preferable to use a closed type apparatus, and it is preferable to knead in an inert gas atmosphere such as nitrogen or carbon dioxide gas. Melt-kneading is usually carried out at 150 to 280°C, preferably 170 to 240°C, for 1 to 20 minutes, preferably 3 to 10 minutes. The thermoplastic elastomer of the present invention is composed of a crosslinking agent, a dynamically heat-treated crosslinked rubber, and a polyolefin resin P, and the weight ratio (R/P) of the copolymer rubber R and the polyolefin resin P used is 90/10. to 50/50, preferably from 85/15 to 60/40. If the weight ratio (R/P) is less than 50/50 and the resin component is large, the thermoplastic elastomer will lose its rubber properties such as flexibility and rebound, and furthermore, the product will suffer from sink marks when injection molding large, thick products. arise. Weight ratio (R/
If P) is 90/10 or more and the resin component is small, the heat resistance, fluidity, and strength of the thermoplastic elastomer will decrease,
It becomes unsuitable for the purpose of the present invention. The thermoplastic elastomer of the present invention, which is composed of crosslinked rubber and polyolefin resin, can be prepared by the following three methods. That is, a method in which the crosslinking agent and the entire amount of the polyolefin resin P used during dynamic heat treatment coexist simultaneously.
(a) A method in which a heat treatment process is carried out in the coexistence of a certain amount of polyolefin resin P, and then this product and the remaining polyolefin resin P are uniformly mixed (b) Ethylene α-olefin system copolymer rubber R
In method (c), the process of dynamically heat-treating the product with a crosslinking agent is carried out without the presence of polyolefin resin P, and then this product and polyolefin resin P are uniformly mixed. In the present invention, any preparation method may be used, but method (a) or (b) is preferred. When methods (d) and (b) are followed, the kneading temperature for the process of dynamic heat treatment with the crosslinking agent described above is carried out at a temperature higher than the melting point of the polyolefin resin P used, which will be described later. In addition, in the case of method (b) or method (c), in order to uniformly mix the product from the heat treatment process and the polyolefin resin P, it is necessary to mix the product from the heat treatment process and the polyolefin resin P pellets or After mixing the powder with a V-type blender, tumbler blender, ribbon blender, Henschel mixer, etc., it is mixed with an extruder, mixing roll, kneader, Banbury mixer, etc. at a temperature higher than the melting point of the polyolefin resin P, usually 150 to 280. A method of kneading at a temperature of °C is preferred. The polyolefin resin P of the present invention includes high density polyethylene, low density polyethylene, and when the ethylene unit content exceeds 95 mol%, ethylene and propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1- Copolymers with α-olefins such as hexane, or monomers with olefinic double bonds other than α-olefins such as ethylene containing 85 mol% or more of ethylene units and vinyl acetate acrylates and methacrylates. Polyethylene resin such as a copolymer with polypropylene or 90 mol% of propylene units
Propylene containing above and α- other than propylene
Crystalline polypropylene resins such as copolymers with olefin; poly-1-butene or 1-butene containing 90 mol% or more of 1-butene units;
-Crystalline poly-1-butene resins such as copolymers with α-olefins excluding butene; poly4-methyl-1-pentene or 4-methyl containing 90 mol% or more of 4-methyl-1-pentene units -1-
Crystalline poly-4-methyl-1-pentene resins such as copolymers with α-olefins excluding pentene;
and mixtures of these resins.
Among them, the melt index (190℃) is 0.1 or more.
Preferred examples include the above polyethylene resin having a melt index of 100 and a crystalline polypropylene resin having a melt index (230° C.) of 0.1 to 100, and mixtures thereof. In order to obtain a thermoplastic elastomer with better moldability in the present invention, the ethylene/α-olefin copolymer rubber R of the present invention having a relatively low molecular weight is used, or a moldability improver described below is added. When using a copolymer rubber R having a low molecular weight, a copolymer rubber R having an intrinsic viscosity [η] of 0.6 to 3.0 dl/g is used. At this time, a moldability improver, which will be described later, may be blended, but even without blending, the thermoplastic elastomer of the present invention maintains sufficient moldability and has high strength, making it suitable for injection molding of large, thick-walled products. However, there are no flow marks or sink marks on the surface of the product, it has excellent gloss, and there is no contamination due to seepage of the moldability improver onto the surface, and of course there is no problem of deformation due to the product's own weight. At this time, the blending of a moldability improver is not excluded, but even if it is blended, it is preferable to limit the moldability improver to 50 parts by weight or less based on 100 parts by weight of the copolymer rubber R from the viewpoints of high strength and surface contamination. When the molecular weight of the copolymer rubber R of the present invention is relatively high, that is, when [η] is 0.3 to 6.0 dl/g, particularly 3.0 to 5.0 dl/g, moldability can be improved by adding a moldability improver. be done. Examples of moldability improvers include peroxide non-crosslinked hydrocarbon rubbery substances, mineral oil softeners, and mixtures thereof. Specific examples of peroxide non-crosslinked hydrocarbon rubber materials include polyisobutylene, butyl rubber, propylene-ethylene copolymer rubber containing 70 mol% or more of propylene, propylene-1-butene copolymer rubber, and atactic polypropylene. It refers to a hydrocarbon-based rubbery substance that does not crosslink or lose fluidity even when mixed with peroxide and kneaded under heat.
Among these, polyisobutylene is most preferred in terms of performance and handling. In the present invention, crosslinking refers to a phenomenon in which the apparent molecular weight of a polymer increases as a result of a competitive reaction between a decomposition reaction and a crosslinking reaction that occur when a polymer is thermally reacted with a peroxide. . In addition, mineral oil-based softeners are used to weaken the intermolecular forces of rubber during roll processing, making processing easier, and helping to disperse carbon black, white carbon, etc., and hardening vulcanized rubber. A high boiling point petroleum distillate used to reduce stiffness and increase flexibility and elasticity.
They are classified into naphthenic, aromatic, etc. The above-mentioned moldability improver is used in an amount of 5 to 100 parts by weight, preferably 10 parts by weight, per 100 parts by weight of copolymer rubber R.
By blending in an amount of 50 to 50 parts by weight, particularly 20 to 40 parts by weight, a thermoplastic elastomer with improved moldability can be obtained. That is, with high strength,
Even when large, thick products are injection molded, products with excellent gloss and no flow marks or sink marks can be obtained. If the blending amount exceeds 100 parts by weight, heat resistance and strength will deteriorate, which is undesirable. When a moldability improver is used, it is usually blended together with copolymer rubber R, a crosslinking agent, and other compounding agents during the heat treatment process. In addition, in the case of the thermoplastic elastomer of the present invention using copolymer rubber R with an intrinsic viscosity [η] of 3 to dl/g, the moldability improver may not be used, or even if it is used, the amount of copolymer rubber R may be 100 parts by weight. against 5
When the amount is less than 1 part by weight, the moldability is poor, but since the strength is higher, it is suitable for manufacturing products that do not require an excellent appearance and have high strength and rubber-like properties. The thermoplastic elastomer of the present invention may contain fillers within the range that does not impair its strength and rubber properties.
For example, calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite,
Add glass fibers, glass bulbs, shirasu balloons, carbon fibers, etc. or coloring agents such as carbon black, titanium oxide, zinc white, iron oxide, ultramarine, deep blue, azo pigments, nitroso pigments, lake pigments, phthalocyanine pigments, etc. be able to. The present invention also uses known heat stabilizers such as phenol, sulfite, phenylalkane, phosphite or amine stabilizers, anti-aging agents, weather stabilizers, antistatic agents, metal soaps, lubricants such as wax, etc. can be blended to the extent used in polyolefin resin or olefin copolymer rubber. In addition, ethylene α- other than the copolymer rubber R of the present invention
Olefin copolymer rubber can also be blended in the heat treatment process within a range that does not impair the effects of the present invention. The thermoplastic elastomer of the present invention can be molded using equipment commonly used for thermoplastic resins, and is suitable for extrusion molding, calendar molding, and especially injection molding. The thermoplastic elastomer of the present invention has heat resistance,
Weather resistance, high strength, excellent rubber properties such as flexibility and repulsion, and good fluidity, making it suitable as a material for large thick products, with a good appearance without flow marks or sink marks. You can get a good product. The thermoplastic elastomer of the present invention can be used for body panels, bumper parts, side shields,
Automotive parts such as steering wheels, footwear such as shoe soles and sandals, electrical parts such as wire coatings, connectors, cap plugs, golf club grips,
Examples include baseball butt grips, swimming fins, swimming goggles and other leisure items, gaskets, waterproof cloth, garden hoses, belts and other miscellaneous items. The thermoplastic elastomer of the present invention is particularly suitable for use in large, thick-walled products such as bumper parts. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. In addition,
Moldability of thermoplastic elastomer in Examples,
Evaluation of basic physical properties was carried out by the following method. [Test method] (1) Injection moldability (A) Molding conditions Injection molding was performed using the following equipment and conditions. Molding machine: Dynamelter (manufactured by Meiki Seisakusho) Molding temperature: 200℃ Injection pressure: Primary pressure 1300Kg/cm ³ Secondary pressure 700Kg/cm ³ Injection pressure: Maximum molding speed: 90 seconds/1 cycle Gate: Direct gate (Rand (Length 10mm, Width 10mm, Thickness 3mm) Molded products: 3 types of square plates (Length 300mm, Width 180mm, Thickness 3, 8, 15mm) (B) Appearance judgment criteria for molded products Flow Mark Rating: Judgment criteria 1: Significantly many flow marks 2: Significantly visible on the entire surface of the molded product 3: Slightly visible on the entire surface 4: Slightly visible only on the opposite side of the gate 5: No flow marks at all Sink marks Rating: Judgment criteria 〇: No sink marks △: Only seen on the opposite side of the gate It was measured. Rating: Criteria〇: Gloss is 25% or more △: Gloss is 10 to 25% ×: Gloss is 10% or less (2) Extrusion moldability (A) Molding conditions Tube with the following equipment and conditions was extruded. Molding machine: 40mmφ extruder (manufactured by Toshiba Machine) Molding temperature: 210℃ Die: Straight die (Die/core = 12.5mm/10.0mm) Take-up speed: 10m/min (B) Appearance criteria for molded products Tube surface The unevenness is evaluated in the following five stages. Rating: Judgment Criteria 5: Skin is extremely smooth and shiny 4: Skin is smooth but not shiny 3: Slightly rough skin 2: Significantly rough skin 1: Large wavy rough skin (3) Basic physical properties Injection molded using the method in (1) A test piece was cut from a square plate with a thickness of 3 mm obtained by the above method, and measured by the following method. Tensile properties: Measured according to JISK-6301 method. Spring hardness: Measured using the JISA type method described in JISK-6301. Permanent elongation: Measured by JISK-6301 method. Heat resistance temperature: The test piece was placed in a constant temperature bath, the temperature of the bath was raised at a rate of 20℃/min, and the temperature was expressed as the temperature at which a needle with a diameter of 0.8 mm with a load of 49 g penetrates the sample by 0.1 mm. . Examples 1 to 4, Comparative Examples 1 to 4 Ethylene/α-olefin/
5-ethylidene-2-norbornene copolymer rubber 70
Part by weight melt fluorate (ASTM D1238, 230
°C) 13, density 0.91 g/ ^cm3 polypropylene (hereinafter
After kneading 30 parts by weight of PP in a Banbury mixer under a nitrogen atmosphere at 180°C for 5 minutes, the mixture was passed through a roll and pellets were produced using a sheet cutter (Step 1). Next, the pellets were mixed with a solution prepared by dissolving and dispersing 0.3 parts by weight of 1.3bis(tert-butylperoxyisopropyl)benzene (hereinafter referred to as peroxide A) in 0.5 parts by weight of divinylbenzene (hereinafter referred to as DVB) using a tumbler blender. The solution was then applied uniformly to the pellet surface.
The pellets were then heated in an extruder under a nitrogen atmosphere for 210°C.
℃ for a residence time of 5 minutes and dynamically heat treated (Step 2). The obtained ethylene, α-olefin,
The basic physical properties and moldability of a pellet-shaped thermoplastic elastomer made of crosslinked rubber of 5-ethylidene-2-norbornene copolymer rubber and PP were evaluated using the method described above. The results are shown in Table 2. Examples 5 to 9, Comparative Examples 5 to 7 Ethylene α-olefin listed in Table 3
Using 5-ethylidene-2-norbornene copolymer rubber, the blended amount of PP was 20 parts by weight in step 1, and in step 1, polyisobutylene (manufactured by Etsuso Co., Ltd., trade name Vistanex MML-100, hereinafter referred to as PIB) was added. ) and 10 parts by weight of naphthenic process oil (hereinafter abbreviated as oil) were added, but the same procedure as in Example 1 was conducted. The results are shown in Table 3. Examples 10 and 11 Ethylene/1-butene/1-butene with a molar ratio of ethylene units and 1-butene units (ethylene/1-butene) of 88/12, an iodine value of 10, and an intrinsic viscosity [η] of 2.8.
After carrying out Step 1 and Step 2 in the same manner as in Example 1 using 5-ethylidene-2-norbornene copolymer rubber in the proportions listed in Table 1, the product of Step 2 and
PP (Example 10), or melt index (ASTM D-1238-65T, 190°C) 1.9, density 0.920
The polyethylene produced by the high-pressure method (Example 11) was mixed in a tumbler mixer in the proportions shown in Table 1, and then uniformly mixed in an extruder at 210°C to obtain pellets (Step 3). . The basic physical properties and processability of this pellet were evaluated in the same manner as in Example 1. The results are shown in Table 3. Example 12, Comparative Examples 8 and 9 Ethylene/1-butene with a molar ratio of ethylene units and 1-butene units (ethylene/butene) of 86/14, an iodine value of 10, and an intrinsic viscosity [η] of 3.5 dl/g. 5-
Table 4 shows the results of the same procedure as in Example 5 except that ethylidene-2-norbornene copolymer rubber was used and the proportions of each component were as shown in Table 1.

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Claims (1)

[Scope of Claims] 1 Consisting of an ethylene unit and an α-olefin unit having 4 to 10 carbon atoms, the molar ratio (ethylene/α-olefin) is 80/20 to 95/5, and the intrinsic viscosity [η] is 0.6 to 6 dl/g of ethylene α
- Consisting of a crosslinked rubber obtained by dynamically heat-treating an olefin copolymer rubber R with a crosslinking agent and a polyolefin resin P, and the weight of the ethylene/α-olefin copolymer rubber R and the polyolefin resin P A thermoplastic elastomer having a ratio (R/P) of 90/10 to 50/50. 2. The elastomer according to item 1, wherein the ethylene/α-olefin copolymer rubber contains a polyene having an iodine value of 4 to 50. 3. The elastomer according to item 1 or 2, wherein the α-olefin is 1-butene. 4 The weight ratio (R/P) of ethylene/α-olefin copolymer rubber R and polyolefin resin P is
The first characterized by being 85/15 to 60/40
The elastomer according to any one of Items 1 to 3. 5 Polyolefin resin P is a crystalline polypropylene resin with a melt flow rate (230°C) of 0.1 to 100, a melt flow rate (190°C) of 0.1 to 100.
5. The elastomer according to any one of items 1 to 4, which is a polyethylene resin of 100% or a mixture thereof. 6. According to any one of items 1 to 5, the thermoplastic elastomer is a product obtained by dynamic heat treatment with a crosslinking agent in the presence of the entire amount of the polyolefin resin P used. elastomer. 7 A product obtained by dynamic heat treatment of a thermoplastic elastomer with a crosslinking agent in the presence of ethylene/α-olefin copolymer rubber R and a part of the polyolefin resin P used, and the remaining polyolefin resin 7. The elastomer according to any one of items 1 to 6, which is a thermoplastic elastomer obtained by uniformly mixing P with P.