JP2000164038A - Polystylene based resin film for electric insulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polystylene base resin film for electric insulation having a high insulating performance and free of deterioration caused by refrigerant owing to excellent heat resistance and chlorofluorocarbon resistance. SOLUTION: An insulating film for a hermetic motor is formed from a polystylene based resin film meeting the conditions that the tensile modulus of elasticity is between 2000 and 5000 MPa, the hinge characteristic is over 50 times, the film thickness is between 75 and 500 μm, and that the haze value is over 15%, wherein the resin material is composed of syndiotactic polystylene, rubber-form resilient body and/or a thermoplastic resin other than syndiotactic polystylene, a polymeride having compatibility or afinity with syndiotactic polystylene and having polar radicals, and an inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polystyrene resin film for electrical insulation, and more particularly, to a styrene polymer having a syndiotactic structure (hereinafter referred to as "styrene polymer").
It may be abbreviated as “syndiotactic polystyrene” or “SPS”. ) As a main material.

[0002]

2. Description of the Related Art An air conditioner discharges indoor heat to the outside by circulating a refrigerant such as chlorofluorocarbon between an indoor unit and an outdoor unit, and conversely, takes in outdoor heat into a room to perform cooling and heating. I do. In such a system,
A compressor (compressor) is used as the outdoor unit,
The air conditioner functions by the compression of the refrigerant by the compressor.

[0003] As described above, since the compressor directly compresses the refrigerant, the inside of the compressor is always filled with the refrigerant. Therefore, a motor for operating the compressor (the built-in compressor as described above) is used. The motor that activates the motor is called a “hermetic motor”.
In addition, since the refrigerant is at a considerably high temperature or at a low temperature, the motor continues to operate under such a severe environment.

The hermetic motor has a structure as shown in FIG. That is, the stator and the rotor are configured as main parts, and a large number of grooves are formed in the inner peripheral portion of the stator in the axial direction, and a groove insulating film is mounted in the grooves. Further, a coil exists in the groove insulating film, and an insulating film is provided in an opening of the groove insulating film. The presence of the groove insulating film and the insulating film allows the coil and the iron core of the stator to be maintained in an insulated state.

Conventionally, polyethylene terephthalate (PET) resin has been used as the material for these groove insulating films and insulating films. In particular, in inverters, which have become the mainstream of air conditioners in recent years, there is a problem that leakage of a very small current is unavoidable when the motor is driven.
The T resin was very effective.

However, as described above, the groove insulating film and the insulating film are always exposed to a high or low temperature refrigerant, and therefore, the presence of impurities in the refrigerant, particularly water, causes the resin polymer to be formed. Easily hydrolyzed,
As a result, the generated oligomer adheres to the sliding portion of the motor, which hinders the driving of the motor, and eventually causes seizure of the sliding portion. A problem has been pointed out that it deteriorates and causes a decrease in thermal efficiency.

Further, the use of a syndiotactic polystyrene film for electrical insulation has been disclosed in JP-A-01-316.
Although it is proposed in Japanese Patent Publication No. 246, in this case, since what is taken up is a stretched film, it has high transparency, and when used in the hermetic motor,
There is a problem that it is difficult to confirm whether a film is inserted or not because of its high transparency.

[0008]

SUMMARY OF THE INVENTION The present invention has been made from this point of view. By using syndiotactic polystyrene or the like as its material, it has high electrical insulation, heat resistance and heat resistance. An object of the present invention is to provide a polystyrene resin film for electrical insulation which is excellent in chlorofluorocarbon property and does not deteriorate due to a refrigerant.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies from such a viewpoint, and as a result, have obtained a specific syndiotactic polystyrene resin having excellent long-term electrical insulation, heat resistance, rigidity, and hinge properties. It has been found that the use can solve the above problem. The present invention
This is based on such knowledge.

That is, the present invention provides the following polystyrene resin film for electrical insulation. (1) A polystyrene resin film for electrical insulation that satisfies the following conditions: Tensile modulus is more than 2000MPa and 5000MPa
Less than. Hinge characteristics must be 50 times or more.

[0011] The film thickness is 75 to 500 µm. Haze is 15% or more. (2) The electrical insulation according to the above (1), wherein the polystyrene-based resin film material is a resin composition containing a styrene-based polymer mainly having a syndiotactic structure or a styrene-based polymer mainly having a syndiotactic structure. For polystyrene resin film. (3) The polystyrene resin film material is (a)
(B) a rubbery elastic body and / or 40 to 10% by weight of a thermoplastic resin other than the styrene-based polymer mainly having a syndiotactic structure; And 100 parts by weight of the total of components (a) and (b)
The polystyrene resin film for electrical insulation according to the above (1) or (2), comprising the inorganic filler (d) in an amount of 0 to 40 parts by weight (including 0). (4) The polystyrene resin film material is (a)
(B) a rubbery elastic body and / or 40 to 10% by weight of a thermoplastic resin other than the styrene-based polymer mainly having a syndiotactic structure; And a total of 100 parts by weight of the components (a) and (b)
(C) 0.1 to 10 parts by weight of a polymer having compatibility or affinity with the component (a) and having a polar group, and a total amount of the components (a) to (c) of 100 parts by weight Against
The polystyrene resin film for electrical insulation according to the above (1) or (2), comprising the inorganic filler (d) in an amount of 0 to 40 parts by weight (including 0). (5) The above (1) to-obtained by the cast molding method.
(4) The polystyrene resin film for electrical insulation according to any of (4). (6) The polystyrene resin film for electrical insulation according to any one of the above (1) to (5), which is used as an insulating film for a hermetic motor.

[0012]

Embodiments of the present invention will be described below. I. Properties of polystyrene resin film for electrical insulation according to the present invention The polystyrene resin film for electrical insulation according to the present invention needs to satisfy the following properties. (1) Tensile elastic modulus is 2000MPa or more and 5000M
It is less than Pa.

[0013] Here, the tensile modulus of elasticity is ASTM D88.
If the value is less than 2000 MPa, the rigidity is low in applications where the coil is inserted into a narrow gap between the coil and the iron core of the stator, such as when used as an insulating film for a hermetic motor. There is a possibility that it cannot be inserted so that the insulating state can be maintained. Conversely, if it exceeds 5000 MPa, cracks are likely to occur when the film is bent. The tensile modulus is preferably 2300 MPa or more and less than 4500 MPa. (2) The hinge characteristic is 50 times or more.

Here, the hinge characteristic is defined in JIS P81.
It is a value measured in accordance with No. 15, and if it is less than 50 times, it is folded in a case where it is inserted into a narrow gap between the coil and the iron core of the stator, particularly when used as an insulating film for a hermetic motor. At that time, the fold may be broken at the time of insertion, and it may not be possible to obtain an insulating state. The hinge characteristics are preferably at least 100 times, more preferably at least 150 times. (3) The film thickness is 75 to 500 μm.

Preferably, the thickness is 100 to 300 μm.
When the thickness is less than 75 μm, the rigidity of the film is insufficient, so that the fixing after the insertion may be insufficient. 5
If it exceeds 00 μm, it may be plastically deformed when bent, and the fold may be broken. (4) Haze is 15% or more.

The haze is measured according to JIS K7105, and is preferably 20% or more.
If it is less than 15%, the transparency may be too high, and it may be difficult to confirm whether or not a film has been inserted. II. Suitable Materials Used for the Polystyrene-Based Resin Film for Electrical Insulation According to the Present Invention The polystyrene-based resin film for electrical insulation according to the present invention is a styrene-based polymer mainly having a syndiotactic structure described below as a preferred material thereof. Alternatively, a resin composition containing the styrene-based polymer is used. 1. Styrene polymer mainly having a syndiotactic structure Syndiotactic structure in a styrene polymer mainly having a syndiotactic structure means that the stereochemical structure is a syndiotactic structure, that is, a main chain formed from carbon-carbon bonds. Has a steric structure in which phenyl groups, which are side chains, are alternately located in opposite directions, and its tacticity is determined by nuclear magnetic resonance (13C)
-NMR). Tacticity measured by the 13C-NMR method can be represented by the existence ratio of a plurality of continuous structural units, for example, a dyad for two, a triad for three, and a pentad for five. The styrenic polymer having a predominantly syndiotactic structure as referred to in the present invention generally means at least 75%, preferably at least 85%, in racemic diad, or at least 30%, preferably 50%, in racemic pentad.
Polystyrene, poly (alkyl styrene), poly (aryl styrene), poly (halogenated styrene), poly (halogenated alkyl styrene), poly (alkoxy styrene), poly (vinyl benzoate) having the above syndiotacticity , These hydrogenated polymers and mixtures thereof, or copolymers containing these as main components. Here, the poly (alkyl styrene) includes poly (methyl styrene), poly (ethyl styrene), poly (isopropyl styrene), poly (tertiary butyl styrene), and the like. (Phenylstyrene),
There are poly (vinylnaphthalene), poly (vinylstyrene) and the like, and as poly (halogenated styrene), there are poly (chlorostyrene), poly (bromostyrene), poly (fluorostyrene) and the like. Examples of poly (halogenated alkylstyrene) include poly (chloromethylstyrene), and examples of poly (alkoxystyrene) include poly (methoxystyrene) and poly (ethoxystyrene).

Among these, preferred styrene polymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), poly (p-tert-butylstyrene), and poly (p-chlorostyrene). ), Poly (m-chlorostyrene), poly (p-fluorostyrene), hydrogenated polystyrene and copolymers containing these structural units.

Such a styrenic polymer having a predominantly syndiotactic structure can be prepared, for example, by using a titanium compound and a condensation product of water and a trialkylaluminum as a catalyst in an inert hydrocarbon solvent or in the absence of a solvent.
It can be produced by polymerizing a styrene-based monomer (a monomer corresponding to the above-mentioned styrene-based polymer) (JP-A-62-187708). For poly (halogenated alkylstyrene), see JP-A-1-4691.
No. 2, these hydrogenated polymers are disclosed in JP-A-1-1785.
It can be obtained by the method described in JP-A-05-2005.

Among these styrenic polymers having a syndiotactic structure, in the present invention, in terms of heat resistance and mechanical strength, tacticity is particularly 70% or more in racemic pentad, and weight average molecular weight. Is 5-8
A thing of 100,000 is preferable. 2. Resin Composition Containing Syndiotactic Polystyrene As the polystyrene resin film for electrical insulation according to the present invention, not only the above-mentioned syndiotactic polystyrene but also a resin composition containing syndiotactic polystyrene can be suitably used. In this resin composition, it is necessary that (a) syndiotactic polystyrene is contained as a resin component, but from the viewpoint of imparting toughness and bending resistance, (b) a rubber-like elastic body and / or mainly It is desirable to include a thermoplastic resin other than a styrene-based polymer having a syndiotactic structure. Further, (d) an inorganic filler may be included. Further, for the purpose of improving the affinity between the components (a), (b) and (c) and effectively compatibilizing the components, the component (c) has compatibility or affinity with the syndiotactic polystyrene. And a polymer having a polar group (so-called compatibilizer)
May be blended.

In addition, various additives such as an antiblocking agent, an antioxidant, a nucleating agent, an antistatic agent, a process oil, a plasticizer, a release agent, a compatibilizing agent, and so on, within a range not to impair the object of the present invention. Flame retardants, flame retardant auxiliaries, pigments and the like can be blended. The kneading of each component can be performed by various methods such as a method of blending and melt-kneading at any stage of the syndiotactic polystyrene production process, and a method of blending and melt-kneading each component constituting the composition. I just need. (1) Rubber-like elastic body Specific examples of the rubber-like elastic body include, for example, natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene, polysulfide rubber, thiochol rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber Styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer ( SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SI
S), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), or ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPD)
M), olefin rubbers such as linear low-density polyethylene elastomers, or butadiene-acrylonitrile-styrene-core-shell rubber (ABS), methyl methacrylate-butadiene-styrene-core-shell rubber (MBS), methyl methacrylate-butyl acrylate-styrene Core-shell rubber (MAS), octyl acrylate-butadiene-styrene-core-shell rubber (MABS), alkyl acrylate-butadiene-acrylonitrile-styrene-core-shell rubber (AAB)
S), butadiene-styrene-core-shell rubber (SB
R), a core-shell type particulate elastic material such as a siloxane-containing core-shell rubber such as methyl methacrylate-butyl acrylate-siloxane, or a rubber obtained by modifying the same, for example, maleic anhydride-modified hydrogenated styrene-butadiene-styrene block copolymer. Polymer (MA
-SEBS) and the like.

Among these rubber-like elastic materials, in the present invention, hydrogenated styrene-butadiene-styrene block copolymer (SEB) is used in view of heat resistance and dielectric properties.
S) is preferred. (2) Thermoplastic resins other than syndiotactic polystyrene Examples of thermoplastic resins other than syndiotactic polystyrene include linear high-density polyethylene, linear low-density polyethylene, high-pressure low-density polyethylene, isotactic polypropylene, and syndoxy. Otactic polypropylene, block polypropylene, random polypropylene, polybutene, 1,2-polybutadiene, 4-methylpentene, cyclic polyolefins and polyolefin resins represented by these copolymers, atactic polystyrene, isotactic polystyrene, HIPS, A
BS, AS, styrene-methacrylic acid copolymer, styrene-methacrylic acid / alkyl ester copolymer, styrene-methacrylic acid / glycidyl ester copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid / alkyl ester copolymer Polystyrene resins such as polymers, styrene-maleic acid copolymers and styrene-fumaric acid copolymers, polyester resins such as polycarbonate, polyethylene terephthalate and polybutylene terephthalate, polyamide 6, polyamide 6,6 And other polyamide resins, polyphenylene ether, polyarylene sulfide, poly-4
-Any known materials such as fluorinated polyethylene resins such as fluorinated ethylene (PTFE) can be used. Among them, polyolefins such as polyethylene and polypropylene or polyphenylene ethers are preferred.
In addition, these thermoplastic resins can be used alone or in combination of two or more. (3) Polymer having compatibility or affinity with syndiotactic polystyrene and having a polar group Syndiotactic polystyrene and thermoplastic resin and / or
Alternatively, it is blended to improve the affinity between the rubber-like elastic body and effectively compatibilize it, and to improve the affinity between the syndiotactic polystyrene and the inorganic filler.

Here, the polymer having compatibility or affinity with syndiotactic polystyrene refers to a polymer having a chain exhibiting compatibility or affinity with syndiotactic polystyrene in a polymer chain. Examples of the polymer exhibiting such compatibility or affinity include, for example, syndiotactic polystyrene, atactic polystyrene, isotactic polystyrene, styrene-based copolymer, polyphenylene ether, polyvinyl methyl ether, and the like. , A block or a graft chain.

The polar group referred to herein may be any group which improves the adhesiveness with an inorganic filler, and specifically includes an acid anhydride group, a carboxylic acid group, a carboxylic ester group, and a carboxylic acid group. Chloride group, carboxylic acid amide group, carboxylic acid group, sulfonic acid group, sulfonic acid ester group, sulfonic acid chloride group, sulfonic acid amide group, sulfonic acid group, epoxy group, amino group, imide group, oxazoline group, etc. No.

This compatibilizer can be obtained by reacting a polymer having compatibility or affinity with the above-mentioned syndiotactic polystyrene and a modifier described below in the presence or absence of a solvent or other resin. it can. As the modifier, for example, a compound containing an ethylenic double bond and a polar group in the same molecule can be used. Specifically, maleic anhydride, maleic acid, maleic ester, maleimide and its N-substituted product, maleic acid derivatives such as maleic acid salt, fumaric acid, fumaric acid ester, and fumaric acid such as fumaric acid salt Derivatives, itaconic anhydride, itaconic acid, itaconic acid esters, itaconic acid derivatives including itaconic acid salts, acrylic acid, acrylic acid esters,
Acrylic acid derivatives such as acrylamide and acrylate, methacrylic acid, methacrylic acid esters, methacrylic acid amides, methacrylic acid salts, and methacrylic acid derivatives such as glycidyl methacrylate are exemplified. Among them, maleic anhydride, fumaric acid and glycidyl methacrylate are particularly preferably used.

A known method is used for the modification.
150 using a mill, Banbury mixer, extruder, etc.
A method of melt-kneading and reacting at a temperature of from 0 to 350 ° C, and a method of heating and reacting in a solvent such as benzene, toluene, and xylene can be exemplified. In order to further facilitate these reactions, benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, t-butyl peroxybenzoate, azobisisobutyronitrile, azobisisovaleronitrile, It is effective to use a radical generator such as 2,3-diphenyl-2,3-dimethylbutane. Of these, 2,3-diphenyl-2,3-dimethylbutane is particularly preferably used.

A preferred modification method is a method of melt-kneading in the presence of a radical generator. Further, at the time of modification, another resin may be added. Specific examples of the compatibilizer include a styrene-maleic anhydride copolymer (SM
A), a styrene-glycidyl methacrylate copolymer,
Carboxylic acid-modified polystyrene, epoxy-modified polystyrene, oxazoline-modified polystyrene, amine-modified polystyrene, sulfonated polystyrene, styrene ionomer, styrene-methyl methacrylate
To-graft polymer, (styrene-glycidyl methacrylate) -methyl methacrylate-graft copolymer, acid-modified acryl-styrene-graft polymer,
(Styrene-glycidyl methacrylate) -styrene-
Graft polymer, polybutylene terephthalate-polystyrene-graft polymer, maleic anhydride-modified P
S, fumaric acid-modified PS, glycidyl methacrylate-modified PS, amine-modified PS and other modified styrenic polymers,
Modified polyphenylene ethers such as (styrene-maleic anhydride) -polyphenylene ether-grafted polymer, maleic anhydride-modified polyphenylene ether, glycidyl methacrylate-modified polyphenylene ether, and amine-modified polyphenylene ether And the like.

Of these, modified PS and modified polyphenylene ether are particularly preferably used. Further, two or more of the above polymers can be used in combination. The polar group content in the compatibilizer is preferably 10
It is in the range of 0.05 to 20% by weight, more preferably 0.05 to 10% by weight, based on 0% by weight. If the content is less than 0.01% by weight, it is necessary to add a large amount of a compatibilizing agent in order to exert an adhesive effect with the inorganic filler, and the mechanical properties, heat resistance, and moldability of the composition may be reduced. Absent. On the other hand, if it exceeds 20% by weight, the compatibility with syndiotactic polystyrene may be undesirably reduced. (4) Inorganic filler The inorganic filler may be fibrous, granular or powdery. As the fibrous filler,
For example, glass fiber, carbon fiber, whisker and the like can be mentioned. The shape is a cross shape, mat shape, focused cut shape,
There are short fibers, filaments, whiskers, etc., and in the case of a bundle cut, those having a length of 0.05 mm to 50 mm and a fiber diameter of 5 to 20 μm are preferred.

On the other hand, as the granular or powdery filler, for example, talc, carbon black, graphite, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, Oxysulfate, tin oxide,
Examples include alumina, kaolin, silicon carbide, metal powder, glass powder, glass flake, glass beads and the like.

Among the various fillers as described above, in particular, particulate and powdery fillers such as glass powder and glass flour.
, Glass beads, talc, carbon black, graphite, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, kaolin, and silicon carbide are preferred. As these fillers, those subjected to surface treatment are preferable. The coupling agent used for the surface treatment is used for improving the adhesiveness between the filler and the resin, and includes a so-called silane-based coupling agent, a titanium-based coupling agent, and the like. Any one can be selected and used. Among them, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β
Preferred are aminosilanes such as-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, epoxysilane, and isopropyltri (N-amidoethyl, aminoethyl) titanate.

As the film former, a conventionally known one can be used, and among them, urethane type, epoxy type, polyether type and the like are preferably used. In addition, these inorganic fillers can be used alone or in combination of two or more. (5) Various additives As long as the object of the present invention is not impaired, various additives exemplified below can be blended.

Antiblocking Agent (AB Agent) Examples of the antiblocking agent include the following inorganic particles or organic particles. As the inorganic particles, IA
, IIA, IVA, VIA, VIIA, VIII, IB
Oxides, hydroxides, sulfides, nitrides, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylate salts of Group IIB, IIIB, IIIB and IVB elements, Examples thereof include silicates, titanates, borates and hydrates thereof, composite compounds centered on them, and natural mineral particles.

Specifically, compounds of Group IA such as lithium fluoride, borax (sodium borate hydrate), magnesium carbonate, magnesium phosphate, magnesium oxide (magnesia), magnesium chloride, magnesium acetate, magnesium fluoride, titanium Magnesium silicate, magnesium silicate, magnesium silicate hydrate (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (gypsum), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, calcium fluoride, titanate Group IIA compounds such as calcium, strontium titanate, barium carbonate, barium phosphate, barium sulfate, barium sulfite, titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), dimonoxide Group VIA element compounds such as IVA element compounds such as conium, molybdenum dioxide, molybdenum trioxide, and molybdenum sulfide; Group VIA element compounds such as manganese chloride and manganese acetate; Group VIII element compounds such as cobalt chloride and cobalt acetate; Group IB element compounds such as cuprous chloride, group IIB compounds such as zinc oxide and zinc acetate, aluminum oxide (alumina), aluminum hydroxide, aluminum fluoride, alumina silicate (alumina silicate, kaolin, kaolinite), etc. III Group B element compounds, silicon oxide (silica, silica gel), graphite, carbon, graphite, glass, etc., Group IVB element compounds, kernalite, kainite, mica (mica, kinunmo), and particles of natural minerals such as byrose ore. Can be

Examples of the organic particles include Teflon, melamine resin, styrene / divinylbenzene copolymer, acrylic resin, and cross-linked products thereof. Antioxidant As the antioxidant, any known antioxidant such as phosphorus-based, phenol-based, and sulfur-based can be used. In addition, these antioxidants may be used alone, or
Two or more can be used in combination.

The nucleating agent is a metal salt of a carboxylic acid such as aluminum di (pt-butylbenzoate) or a phosphoric acid such as sodium methylenebis (2,4-di-t-butylphenol) acid phosphate. Any of known metal salts, talc, phthalocyanine derivatives and the like can be used. These nucleating agents can be used alone or in combination of two or more. Plasticizers Examples of the plasticizer include polyethylene glycol, polyamide oligomer, ethylene bisstearamide, phthalic acid ester, polystyrene oligomer, and the like. Any known materials such as polyethylene wax and silicone oil can be arbitrarily selected and used. These plasticizers can be used alone or in combination of two or more.

Release Agent The release agent may be arbitrarily selected from known materials such as polyethylene wax, silicone oil, long-chain carboxylic acid, and metal salt of long-chain carboxylic acid. These release agents may be used alone or in combination of two or more.

Process Oil In the present invention, a process oil may be further blended. Process oils are roughly classified into paraffin-based oils, naphthenic-based oils, and aroma-based oils, depending on the type of oil. As the viscosity of the process oil, the kinematic viscosity at 40 ° C. is 15 to 600.
cs is preferable, and 15 to 500 cs is more preferable.

These process oils can be used alone or in combination of two or more. (6) Mixing ratio of each component Regarding the mixing ratio of each component, (a) 60 to 90% by weight of syndiotactic polystyrene, preferably 65 to 90% by weight.
85% by weight, further 70-80% by weight, (b)
Thermoplastic resin other than rubbery elastic body and / or styrenic polymer mainly having a syndiotactic structure
10% by weight, preferably 35-15% by weight, and even 3%
0 to 20% by weight. If the component (b) is more than 40% by weight, the elastic modulus may be reduced. Further, when a polymer (c) having compatibility or affinity with the component (a) and having a polar group is blended, the ratio of the component (c) is determined by comparing the ratio of the component (a) with the component (b). ) 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the total of components. If the amount is less than 0.1 part by weight, the effect of bonding with the inorganic filler is small, and insufficient adhesion between the resin and the inorganic filler occurs. become. (D) The inorganic filler is used in an amount of 0 to 40 parts by weight (including 0), preferably 5 parts by weight, based on 100 parts by weight of the total of the components (a) to (c).
３５35 parts by weight, more preferably 5 to 35 parts by weight. If the amount of the inorganic filler is more than 40 parts by weight, cracks are likely to occur when the film is bent. III.Method for producing polystyrene resin film for electrical insulation according to the present invention The method for producing the polystyrene resin film for electrical insulation according to the present invention is not particularly limited, but from the viewpoint of simplicity and economy, cast molding is preferred. It is preferably used. IV. Use of Polystyrene Resin Film for Electrical Insulation According to the Present Invention The polystyrene resin film for electrical insulation according to the present invention is preferably used in a place where electrical insulation is required in an electric component. It is suitably used as a film and an insulating film.

[0038]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 SPS (Syndiotactic polystyrene homopolymer, Tm = 270 ° C., MI = 13 (300
Dry blended with 75% by weight of 1.2 kgf)) and 25% by weight of SEBS (hydrogenated styrene-butadiene copolymer, “Septon 8006” manufactured by Kuraray) as a rubber-like elastic material, and 65 mmφ biaxial. Pellets were obtained by melt-kneading with an extruder.

Next, the material was cast-formed under the conditions of a T-die temperature of 300 ° C. and a roll temperature of 90 ° C. to obtain a polystyrene resin film for electrical insulation. The polystyrene resin film for electrical insulation was as follows. (1) The tensile modulus was 2,200 MPa. (2) The hinge characteristic was 200 times or more. (3) The film thickness was 250 μm. (4) Haze was 35%.

Next, this polystyrene resin film for electrical insulation was evaluated for its CFC resistance in the following manner.
Into a 1 liter pressure-resistant autoclave, 100 g of the test piece of the film was put, and 200 g of monochlorodifluoromethane (CFC 22) was sealed therein. The internal temperature was raised to 80 ° C. and kept at this temperature for 8 hours. afterwards,
After cooling to room temperature, monochlorodifluoromethane was removed through a filter having a No. 400 SUS mesh. The solid matter adhering to the mesh was collected and weighed to be 0.04 g, and the generation of decomposed solid matter by Freon was extremely small. [Embodiment 2] Instead of SPS in Embodiment 1, SP
As S, syndiotactic styrene-p-methylstyrene copolymer ((p-methylstyrene content: 12 mol%), Tm = 241 ° C., MI = 3 (300 ° C., 1.2 k
gf))) was carried out in the same manner as in Example 1 except that gf))) was used.

The polystyrene resin film for electrical insulation was as follows. (1) The tensile modulus was 2,200 MPa. (2) The hinge characteristic was 250 times or more. (3) The film thickness was 250 μm. (4) Haze was 32%.

This polystyrene resin film for electrical insulation was evaluated for CFC resistance in the same manner as in Example 1. The weight of the solid matter deposited on the mesh was 0.03 g, and the generation of the decomposed solid matter by Freon was extremely small. [Comparative Example 1] A biaxially stretched polyethylene terephthalate (PET) film (Lumirror 250 (250 μm) type H10 manufactured by Toray Industries, Inc.) was used as the resin film for electrical insulation, and the Freon resistance was evaluated in the same manner as in Example 1. . The weight of the solid matter deposited on the mesh was 0.35 g, and the generation of decomposed solid matter by Freon was large.

[0043]

According to the present invention, it is possible to obtain a polystyrene resin film for electrical insulation which has high electrical insulation properties and is excellent in heat resistance and chlorofluorocarbon resistance and does not deteriorate due to a refrigerant.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a hermetic motor.

[Explanation of symbols]

 1: Compressor container 2: Hermetic motor 3: Stator 4: Rotor 5: Coil 6: Groove 7: Groove insulating film 8: Insulating film 9: Iron core

Continued on the front page F-term (reference) 4F071 AA10 AA15 AA20 AA22 AA75 AA77 AA78 AB01 AE17 AF13Y AF20Y AF30Y AF39 AH17 BA01 BB02 BC01 BC10 BC12 4J002 AC012 AC032 AC062 AC072 AC082 BB032 BB122 BC03 BC031 BC031 BCBC BG042 BH013 BN122 BN132 BN142 BN152 BN162 BN203 BP012 CF062 CF072 CG012 CH072 CK032 CL012 CL032 CN022 CP032 DA026 DA036 DA066 DE096 DE136 DE146 DE236 DG046 DJ006 DJ016 DJ046 DJ056 DL006 FB0920 FB166 FD016 FB016 FD016 FB166 FD016 FB166 FD016 HC54 JA28 5G305 AA02 AB01 AB24 AB40 BA18 BA26 CA02 CA45 CA47 CD01

Claims (6)

[Claims] 1. A polystyrene resin film for electrical insulation satisfying the following (1) to (4). (1) Tensile elastic modulus is 2000MPa or more and 5000M
It is less than Pa. (2) The hinge characteristic is 50 times or more. (3) The film thickness is 75 to 500 μm. (4) Haze is 15% or more. 2. The electricity according to claim 1, wherein the polystyrene-based resin film material is a resin composition containing a styrene-based polymer having a predominantly syndiotactic structure or a styrene-based polymer having a predominantly syndiotactic structure. Polystyrene resin film for insulation. 3. The polystyrene resin film material comprises (a) 60 to 90% by weight of a styrene polymer having a predominantly syndiotactic structure, and (b) a rubbery elastic body and / or a predominantly syndiotactic structure. 0 to 40 parts by weight (including 0) of the inorganic filler based on 40 to 10% by weight of a thermoplastic resin other than the styrenic polymer and 100 parts by weight of the total of the above components (a) and (b) The polystyrene resin film for electrical insulation according to claim 1 or 2, which comprises (d). 4. The polystyrene resin film material comprises (a) 60 to 90% by weight of a styrenic polymer mainly having a syndiotactic structure, and (b) a rubber-like elastic material and / or mainly a syndiotactic structure. The compatibility or affinity between the component (c) and the component (a) is determined with respect to 40 to 10% by weight of a thermoplastic resin other than the styrene-based polymer and a total of 100 parts by weight of the component (a) and the component (b). 0.1 to 10 parts by weight of a polymer having a polar group and 0 to 40 parts by weight (including 0) of inorganics based on 100 parts by weight of the total of components (a) to (c) Filler (d)
The polystyrene resin film for electrical insulation according to claim 1, which comprises: 5. The polystyrene resin film for electrical insulation according to claim 1, which is obtained by a cast molding method. 6. The polystyrene resin film for electrical insulation according to claim 1, which is used as an insulating film for a hermetic motor.