JP2007254634A - Resin composition and molded article comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition in which a polyimide crushed product is added to improve the mechanical characteristics, moldability and slidability of a thermoplastic resin, and to provide a molded article using the same. <P>SOLUTION: This resin composition comprises (A) 100 pts.wt. of a thermoplastic resin such as a polyamide, polybutylene terephthalate or polyphenylene sulfide and (B) 0.005 to 100 pts.wt. of resin molded article crushed product consisting mainly of a polyimide and having an average particle diameter of ≤50 μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin composition obtained by adding a polyimide pulverized product to a thermoplastic resin and improving the mechanical properties, moldability, and slidability of the thermoplastic resin, and a molded product using the same.

  Polyimide resin has been rapidly used in engineering and plastics due to its excellent heat resistance, mechanical properties, sliding properties, etc. in recent years in electrical and electronic equipment applications, automotive parts applications, aerospace applications, office equipment applications, etc. Demand is increasing.

  In many thermoplastic resins, including engineering plastics, solid resins are plasticized and melted using screws, etc., and cooled and solidified in any shape to obtain products such as molded products, films and sheets. .

  That is, a thermoplastic resin is formed into a molded article using a method such as melt injection molding or extrusion molding such as sheet molding or blow molding, and any molding method is melted at a temperature above the melting point or softening point. Is a feature.

  On the other hand, in the molding of polyimide resin, polyimide is classified as a non-thermoplastic resin and does not have a clear melting point, so resin powder is placed in a mold and compressed in a uniaxial direction to form a green compact. In addition, a free sintering method in which the resin grain interface is joined by heating and sintering in an inert gas atmosphere such as nitrogen gas, and a hot press method in which pressurization and heating are performed simultaneously are used.

  In addition, a method is used in which a polyimide film is obtained by applying a polyimide film in the state of polyamic acid, which is a polyimide precursor, and imidizing after drying through a dehydration cyclization reaction by heating or the like.

  Polyimide resin molded products such as polyimide films obtained by such a method have extremely rigid and good electrical properties and wear resistance, etc., and are processed by proceeding with imide ring closure by treatment at high temperatures. Insoluble in chemicals such as solvents, it becomes insoluble even at high temperatures, and has excellent chemical resistance and heat resistance.

  For this reason, the polyimide resin molded product does not remelt unlike the molded product made of the thermoplastic resin described above, and the polyimide resin that has been heated and imidized in the sintering step has a decomposition start temperature of 400 ° C. or higher. Due to its high cost, polyimide exhibits extremely stable mechanical and dimensional characteristics at the melting and processing temperatures of many resins including ordinary engineering plastics.

  Usually, the sliding characteristics of thermoplastic resins including engineering plastics are influenced by the mechanical characteristics and melting point of the resin, and are not necessarily good, and the recent market requirements for sliding characteristics are becoming stricter. At present, inorganic or organic slidability imparting agents are added.

  However, since inorganic fillers and minerals used as slidability imparting agents have high hardness, it is easy to damage the metal or resin that is the counterpart material of the sliding part. The characteristics may be deteriorated. On the other hand, organic slidability imparting agents such as high-density polyethylene and silicon resin have difficulty in heat resistance such as the polar groups and melting points inherent in the resin, and the sliding properties in the high temperature range are low at present. is there.

  Under such circumstances, a composition in which a polyimide powder is blended with a tetrafluoroethylene resin (Patent Document 1), a composition in which a polyimide resin powder is blended with a fluororesin (Patent Document 2), and radiation-irradiated intermolecular crosslinking In addition, a composition (Patent Document 3) in which polyimide is blended as a filler to a fluororesin surface-treated with a silane coupling agent and an engineering plastic is disclosed.

However, these compositions are not sufficient in terms of mechanical properties and sliding properties.
JP-A-9-71704 (Claims) JP-A-9-95543 (Claims) JP 2003-253073 A (Claims)

  In the present invention, a polyimide resin having extremely high sliding properties and good mechanical properties at high temperatures is added to thermoplastic resins including engineering plastics, and the polyimide resin is used as a property improving agent for other resins. It is an object of the present invention to provide a resin composition having properties, moldability, and slidability, and a molded product thereof.

  As a result of intensive studies to solve the above problems, the present inventors pulverized polyimide resin molded products or polyimide films that have undergone heat treatment and progressed to imidization, and heat the pulverized products having particle sizes described below. The resin composition was obtained by mixing at a specific ratio as a property improving agent for a plastic resin, and it was found that a molded product having good mechanical properties, moldability, and slidability was obtained, and the present invention was achieved. .

That is, the present invention
(1) (A) 100 parts by weight of a thermoplastic resin and (B) 0.005 to 100 parts by weight of a pulverized resin molded product having a mean particle diameter of 50 μm or less mainly composed of polyimide are mixed. Resin composition,
(2) (B) The resin composition according to (1), wherein the resin molded product containing polyimide as a main component is a film.
(3) The resin composition according to (1) or (2), wherein the average particle size of the pulverized product mainly comprising polyimide (B) is 1 to 10 μm,
(4) (B) The resin composition according to any one of (1) to (3), wherein the pulverized product of the resin-molded product mainly composed of polyimide is a pulverized product made of polyimide having an imide ring closure rate of 90% or more,
(5) (A) The resin composition according to any one of (1) to (4), wherein the thermoplastic resin is at least one selected from the group consisting of polyamide, polybutylene terephthalate and polyphenylene sulfide, and (6) ( It is a resin molded product which consists of the resin composition in any one of 1)-(5).

  The resin composition having good slidability of the present invention can impart good mechanical properties, moldability, and slidability by pulverizing and adding a resin molded product mainly composed of polyimide to a thermoplastic resin. It can be used for various applications such as electrical / electronic equipment applications, automotive parts applications, aerospace applications, and office equipment applications.

  Embodiments of the present invention will be described below. In the present invention, “weight” means “mass”.

(Thermoplastic resin)
The thermoplastic resin used in the present invention is not particularly limited, and any thermoplastic resin including general-purpose plastics and engineering plastics can be used.

  This is because the polyimide resin described later has the highest thermal characteristics such as melting point and heat resistance with respect to known thermoplastic resins, and there is a thermoplastic resin having thermal characteristics substantially exceeding that of the polyimide resin. Because it is not.

  Examples of thermoplastic resins include general-purpose plastics such as polyethylene, polypropylene, polystyrene, and ABS resins. Engineering plastics include polyamide, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polycarbonate, polyphenylene ether, and modified polyphenylene ether. . In addition, super engineering plastics with higher thermal properties can be used. Examples include polyphenylene sulfide, polyarylate, polysulfone, polyetherimide, polyetherketone, polyetheretherketone, polyamideimide, and liquid crystal polyester. Can be mentioned.

(Polyimide)
In the present invention, a pulverized resin molded product containing polyimide as a main component is used. The polyimide used as the main component of the resin molded product will be described.

  A known method can be used for producing polyimide. For example, Japanese Patent Publication No. 39-22196 discloses the details thereof, but aromatic tetracarboxylic dianhydride and aromatic diamine or aromatic diisocyanate can be converted into, for example, N-methylpyrrolidone, N, N-dimethylacetamide. It can be produced by reacting in an organic polar solvent such as diglyme and ring-closing the resulting polyamic acid with a dehydrated imide.

  Specific examples of the aromatic tetracarboxylic dianhydride used here include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4. '-Biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3' , 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarbohydrate Dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, and the like. These acid dianhydrides can also be used in the form of derivatives thereof such as carboxylic acid, ester, acid chloride and the like.

  Specific examples of the aromatic diamine and aromatic diisocyanate include p-phenylenediamine, m-phenylenediamine, 2-chloro-p-phenylenediamine, benzidine, 2-chlorobenzidine, 4,4′-diaminodiphenylmethane, 4,4. '-Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 3, 3'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminoterphenyl, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene 1,3-bis (4-aminophenyl) Noxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] ketone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4 Examples include '-bis (3-aminophenoxy) biphenyl and the like and diisocyanates thereof.

  As a preferred combination of polyimide resins used in the present invention, examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, Examples of aromatic diamines and aromatic diisocyanates include p-phenylene diamine, m-phenylene diamine, and 4,4′-diaminodiphenyl ether, specifically obtained from pyromellitic dianhydride and 4,4′-diaminodiphenyl ether. Polyimide resin, pyromellitic acid dianhydride, 4,4′-diaminodiphenyl ether and polyimide resin obtained from m-phenylenediamine, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 4,4 Polyimide resin obtained from '-diaminodiphenyl ether And the like.

  A more preferable polyimide resin includes a polyimide having the following repeating unit obtained from pyromellitic dianhydride and 4,4'-diaminodiphenyl ether as a main structure.

  Here, the thing in which the part of the imide group remains in the state of the amide acid which is the ring-closing precursor is also included. The imide cyclization rate of the raw polyimide resin thus produced is controlled to be low because the polyimide resin cannot be melt-processed, and is used for molding and film formation by methods described later.

(Crushed product of resin molded product mainly composed of polyimide)
A resin molded product containing polyimide as a main component is usually molded into a green compact by compressing in a uniaxial direction a raw material containing the above-mentioned polyimide resin powder as a main component in a mold. It is manufactured by a method such as a free sintering method in which the resin grain interface is joined by heating and sintering in an inert gas atmosphere such as a gas, or a hot press method in which pressurization and heating are performed simultaneously.

  The “pulverized product of a resin molded product mainly composed of polyimide” used in the present invention is a polyimide resin molded product as described above, that is, a heat treatment such as a sintering process in the free sintering method or heating in hot press molding. It is a pulverized product obtained by pulverizing a resin molded product in which imide ring closure is promoted. In general, resin molded products that are actually used or in a usable state, that is, parts, products, intermediate products thereof, scraps generated in the manufacturing process, shape defects, appearance defects, density heterogeneity, etc. Resin-molded products that have been determined to be defective due to the above defects.

  Polyimide resin molded products are often sold as raw materials such as plates and round bars, and such shaped materials are processed into products according to the shape of the parts. At that time, wastes such as offcuts and chips are generated. These can be used as a pulverized product by performing an appropriate cleaning operation.

The imide ring closure rate of the polyimide resin in the pulverized product of the resin molded product mainly containing polyimide used in the present invention is increased by the above-mentioned heating. If the imide ring closure rate is high, it becomes insoluble even at high temperatures, such as organic solvents. It is insoluble in chemicals and has excellent chemical resistance, heat resistance, sliding characteristics, and extremely stable mechanical and dimensional characteristics. The imide cyclization rate of the polyimide resin in the present invention is the ratio of the polyamic acid portion which is a polyimide resin precursor in the polymer to the portion where the polyamic acid portion is dehydrated to become an imide group, and is measured using an infrared method or the like. Is possible. The imide ring closure rate referred to in the present invention is determined by the infrared method, and the infrared spectroscopic measurement is performed on the pulverized resin molded product using the KBr method, and the peak heights of 1780 cm ⁻¹ and 1245 cm ⁻¹ are measured. The peak height ratio was calculated to determine the imide ring closure rate. In the present invention, the resin-molded product containing polyimide as a main component or the pulverized product imide cyclization rate of the film is preferably 90% or more, more preferably 95% or more. It is preferable to use a resin having an imide cyclization rate of 90% or more with little variation in properties as a resin.

  The pulverized product of the resin molded product mainly composed of polyimide used in the present invention can be a pulverized product of the resin molded product as reuse of the resin molded product. Various resin fillers and additives can be added to resin molded products mainly composed of polyimide to be reused as necessary, and desirable properties can be imparted. Examples include fluorine resins such as graphite and PTFE, inorganic fillers such as molybdenum disulfide, boron nitride, and glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, aluminum, silver, copper, lead and other simple metals or various metals. An oxide etc. are mentioned. “Polyimide as a main component” as used herein means that polyimide is contained in a resin molded product or film and has good mechanical properties, heat resistance, sliding properties, etc. However, preferably, a resin molded article containing 30% or more of polyimide is pulverized and used. More preferably, a resin molded product containing 40% or more is pulverized and used.

(Pulverized product of polyimide-based film)
In addition, a film containing a polyimide resin as a main component (hereinafter sometimes referred to as a polyimide film) is usually in the state of polyamic acid, which is a polyimide precursor, and an additive is added as desired. It is produced by imide ring closure through a dehydration cyclization reaction with heating or a dehydrating agent.

  The “pulverized product of polyimide as a main component” used in the present invention refers to a polyimide film as described above, that is, a polyimide film that has been processed using heating or a dehydrating agent to accelerate imidization. This is a crushed piece. In general, polyimide films that are actually used or in a usable state, that is, defects such as parts, products, intermediate products of these, and manufacturing processes, edge materials, shape defects, and appearance defects that occur in the film forming process. The polyimide film judged to be a defective product.

  Polyimide films are also often discarded due to various defects such as pinholes and non-uniform film pressure, and many defects such as defectives and scraps are generated in the processing process. These can also be reused after appropriate cleaning operations and pulverization.

  Furthermore, for parts recovered from the market such as flexible printed circuit boards using polyimide film used for devices such as mobile phones and substrates laminated with different materials from a range of materials that do not impair the effects of the present invention However, it is possible to pulverize and reuse the polyimide film portion as necessary or without separation.

The imide cyclization rate of the polyimide resin in the pulverized product of the polyimide-based film used in the present invention is increased by using the heating or dehydrating agent described above, and if the imide cyclization rate is high, it becomes unmelted even at high temperatures. It is insoluble in chemicals such as organic solvents, and has excellent chemical resistance, heat resistance, sliding characteristics, and extremely stable mechanical and dimensional characteristics. The imide cyclization rate of the polyimide resin in the present invention is the ratio of the polyamic acid portion which is a polyimide resin precursor in the polymer to the portion where the polyamic acid portion is dehydrated to become an imide group, and is measured using an infrared method or the like. Is possible. The imide ring closure rate referred to in the present invention is determined by the infrared method, and the infrared spectroscopic measurement is performed on the pulverized resin molded product using the KBr method, and the peak heights of 1780 cm ⁻¹ and 1245 cm ⁻¹ are measured. The peak height ratio was calculated to determine the imide ring closure rate. In the present invention, the resin-molded product containing polyimide as a main component or the pulverized product imide cyclization rate of the film is preferably 90% or more, more preferably 95% or more. If the imide ring closure rate is low, the properties as a resin tend to fluctuate, which is not preferable.

  The film mainly composed of the polyimide to be reused used in the present invention can be blended with various fillers and additives as necessary to give desirable characteristics. Examples of the agent include fluorine resin such as graphite and PTFE, inorganic filler such as molybdenum disulfide, boron nitride, and glass fiber, carbon fiber, aramid fiber, potassium titanate fiber, aluminum, silver, copper, lead and the like alone Examples include various metal oxides. “Polyimide as a main component” as used herein means that polyimide is contained in a resin molded product or film and has good mechanical properties, heat resistance, sliding properties, etc. However, preferably, a film containing 30% or more of polyimide is pulverized and used. More preferably, a film containing 40% or more is used after being pulverized.

(Crushing method)
The resin molded product or film mainly composed of polyimide used in the present invention can be pulverized by any method as long as it can be pulverized. For example, it is possible to pulverize resin molded products and films mainly composed of polyimide using a uniaxial rotating cutter pulverizer, biaxial pulverizer, biaxial shear pulverizer, horizontal pulverizer, cutter mill, ball mill, etc. It is not restricted by these methods. Depending on the ability of the machine used for pulverization and the shape and size of the resin molded product or film to be pulverized, it can be pulverized in one stage or divided into a plurality of stages.

  In order to obtain a pulverized product more efficiently, it is desirable to pulverize at room temperature or lower. The lower the pulverization temperature, the better the pulverization efficiency of the resin molded product and the film, and the shorter the pulverization time, which is industrially advantageous. Most preferably, it is cooled using carbon or the like and pulverized at -40 ° C or lower. Although there is no restriction | limiting in particular as a minimum of a grinding | pulverization temperature, It is preferable that it is normally -196 degreeC or more from a viewpoint of workability | operativity, such as refrigerant handling.

  Further, since the pulverized product may be mixed with the coarsely pulverized product, and the crushed product may deteriorate the mechanical properties and the like, it is preferable that the pulverized product is classified and the particle size distribution, that is, the particle size of the pulverized product is made uniform. Any method can be used to equalize the particle size of the pulverized product of the present invention. For example, methods such as a vibration method using a sieve and an airflow method using air can be used, but the method is not limited to these methods. The average particle size of the pulverized product of the present invention having the same particle size in this manner is 50 μm or less, and preferably 1 to 10 μm, but a pulverized product smaller than 1 μm is mixed in a small amount of about several percent. Can be used as long as the object of the present invention is not impaired.

(Average particle size)
The average particle size of the resin molded product or film pulverized product mainly composed of the polyimide of the present invention is the median diameter, and the resin molded product or film pulverized product mainly composed of the reused polyimide is shaped. Is not a uniform spherical shape, it is measured and calculated by a laser diffraction method / scattering method.

  In addition, resin molded products mainly composed of polyimide to be reused and pulverized products of films are somewhat cohesive, and in the dry method, the diameter of pulverized product aggregates may be erroneously measured. Is measured by a wet method in which aggregation is suppressed.

  In other words, as a method for measuring the average particle size of resin molded products and film pulverized products mainly composed of polyimide to be reused, a laser diffraction method / scattering method using a wet method, and a specific measuring instrument Is a microtrack particle size distribution measuring device MT3300EX (Nikkiso Co., Ltd.).

  In the present invention, (B) the average particle size of a pulverized product of a resin molded product such as a film containing polyimide as a main component is 50 μm or less, preferably 1 to 10 μm. When the average particle size is larger than 50 μm, the mechanical properties of a molded product obtained by mixing with a thermoplastic resin are deteriorated, so that it is not practical.

  Moreover, mechanical properties such as tensile strength of the thermoplastic resin composition in which the pulverized product is mixed by setting the average particle diameter of the pulverized product of the resin molded product such as a film mainly composed of polyimide to be reused to 1 μm or more. Is preferable, and the handling of the pulverized product is also good.

  In the case where the resin molded product or polyimide film mainly composed of these pulverizable polyimides is combined with a different material, foreign substances or different materials may be separated and cleaned in advance or after pulverization. As long as the purpose of is achieved, it is not specified.

(Polyamide resin)
In the present invention, a polyamide resin can be used as the thermoplastic resin.

  The polyamide resin used (hereinafter sometimes referred to as a nylon resin) is a polyamide resin mainly composed of amino acids, lactams or diamines and dicarboxylic acids. Representative examples of the main constituents include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and p-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetra Methylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, m- Xylylenediamine, p-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, Bis (4-aminocyclohexyl) methane, bi Aliphatic, alicyclic and aromatic diamines such as bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, And adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydro Aliphatic, alicyclic, and aromatic dicarboxylic acids such as terephthalic acid and hexahydroisophthalic acid can be mentioned. In the present invention, polyamide homopolymers or copolymers derived from these raw materials are each singly or in the form of a mixture. Can be used.

  In the present invention, a particularly useful polyamide resin is a polyamide resin excellent in heat resistance and strength. Specific examples thereof include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polytetra Methylene adipamide (polyamide 46), polyhexamethylene sebamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), Polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T) 6I), polyxylylene adipamide (polyamide XD6), polynonamethylene terephthalamide (polyamide 9T), polynonamethylene isophthalamide (9I), polynonamethylene terephthalamide / polynonamethylene isophthalamide (9T) / 9I) and mixtures or copolymers thereof. Here, T represents a terephthalic acid unit, and I represents an isophthalic acid unit.

  The degree of polymerization of these polyamide resins is not particularly limited, but those having a concentrated sulfuric acid relative viscosity in the range of 1.5 to 6.5, particularly in the range of 2.0 to 5.0 are preferred. In the present invention, the concentrated sulfuric acid relative viscosity means a relative viscosity measured at 25 ° C. in a 1% concentrated sulfuric acid solution.

(Polybutylene terephthalate resin)
In the present invention, a polybutylene terephthalate resin can be used as the thermoplastic resin.

  The polybutylene terephthalate resin used (hereinafter sometimes abbreviated as PBT resin) is a polycondensation reaction mainly composed of terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative. It refers to a polymer obtained by a usual polymerization method such as The polybutylene terephthalate resin may contain other copolymerization components as long as the properties of the polybutylene terephthalate resin are not impaired, for example, in a range of about 20% by weight or less. Preferred examples of these polymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate). ), Poly (butylene / ethylene) terephthalate, and the like. These may be used alone or in admixture of two or more.

(Polyphenylene sulfide resin)
In the present invention, a polyphenylene sulfide resin can be used as the thermoplastic resin.

  The polyphenylene sulfide resin used (hereinafter sometimes abbreviated as PPS resin) is a polymer having a repeating unit represented by the following structural formula,

  From the viewpoint of heat resistance, the polymer preferably contains 70 mol% or more, more preferably 90 mol% or more of a polymer containing a repeating unit represented by the above structural formula. Moreover, about 30 mol% or less of the repeating unit of the PPS resin may be composed of a repeating unit having the following structure.

  The PPS resin used in the present invention is a polymer having a relatively small molecular weight obtained by a generally known method, that is, a production method represented by Japanese Patent Publication No. 45-3368, and a production method represented by Japanese Patent Publication No. 52-12240. A method for obtaining an essentially linear and relatively high molecular weight polymer obtained by the method described in JP-A 61-7332, and JP-B-57-334. The polymer can be produced by a method of obtaining a polymer having a branched structure in an oxygen atmosphere or without a crosslinking step in which a crosslinking agent such as peroxide is added and heated.

  In the present invention, the PPS resin obtained as described above is subjected to crosslinking / high molecular weight by heating in air, heat treatment in an inert gas atmosphere such as nitrogen or reduced pressure, organic solvent, hot water, acid aqueous solution, etc. It is also possible to use it after washing with. In the case of washing with an organic solvent, the organic solvent to be used is not particularly limited as long as it does not have an action of decomposing PPS. For example, N-methylpyrrolidone, dimethylformaldehyde, dimethylacetamide, 1,3-dimethylimidazolidinone Nitrogen-containing polar solvents such as hexamethylphosphoramide and piperazinones, sulfoxide and sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone and sulfolane, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone and acetophenone, dimethyl ether and dipropyl ether -Ether solvents such as tellurium, dioxane, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene dichloride, perchloroethylene, monochloroethane, dichloroethane, tetrachloro Halogen solvents such as ethane, perchloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanole, ethylene glycol, propylene glycol, phenol, cresol And alcohol / phenol solvents such as polyethylene glycol and polypropylene glycol, and aromatic hydrocarbon solvents such as benzene, toluene and xylene. There is no restriction | limiting in particular also about washing | cleaning temperature, Usually, about normal temperature-about 300 degreeC are selected. In the case of washing with an acid aqueous solution, the acid to be used is not particularly limited as long as it does not have an action of decomposing PPS, and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propyl acid. Moreover, it can also be used after performing various treatments such as activation with a functional group-containing compound such as an acid anhydride group, an epoxy group, or an isocyanate group.

(Mixed product)
In the present invention, when (A) a thermoplastic resin and (B) a pulverized product of a resin molded product mainly composed of polyimide are mixed, various fillers are blended as necessary to impart desirable characteristics. Examples of such fillers include inorganic fillers such as graphite, molybdenum disulfide, boron nitride, glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, aluminum, silver, copper, lead, etc. Or a variety of metal oxides. Although there is no restriction | limiting in particular in the mixing | blending ratio of this filler, From the point of mechanical characteristics or a sliding characteristic, graphite and carbon fiber are used preferably.

(Composition of each component)
The method for producing the resin composition of the present invention is usually produced by a known method. For example, a resin composition obtained by melt-kneading at a temperature equal to or higher than the melting point of the thermoplastic resin or the glass transition temperature, preferably 180 to 380 ° C., using a single-screw extruder, a twin-screw extruder, a kneader-type kneader, or the like. (B) A resin molded product or a pulverized product of polyimide as a main component is used on the surface of the thermoplastic resin powder or pellets by using a drum rotating type or mixer type blending machine. A resin composition can be obtained by adhering and blending with or without an additive such as silicone oil as long as the effect is not impaired.

  In the case of melt kneading, (A) a thermoplastic resin and (B) a resin molded product or a pulverized product of a polyimide as a main component are premixed or supplied to an extruder or the like and sufficiently melt kneaded. To be prepared. In addition, (B) a resin molded product containing polyimide as a main component or a pulverized product of a film is used alone or premixed with other additives or fillers within a range not impairing the purpose of the present invention, A type feeder can be used to feed the extruder.

  The method for blending is not particularly limited, and using a tumbler, Henschel mixer, or the like, (A) a resin molded product or a pulverized product of a film mainly composed of (B) a polyimide resin and other additives. And the like, and blended at a temperature not higher than the melting point or glass transition temperature of the thermoplastic resin, preferably at room temperature.

  The resin composition obtained as described above can be formed into an arbitrary shape by known methods currently used for molding thermoplastic resins, such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding and gas assist molding. To form a molded product.

  In the present invention, the mixing ratio of (A) a thermoplastic resin and (B) a pulverized resin molded product containing polyimide as a main component is based on (A) 100 parts by weight of the thermoplastic resin in order to obtain good mechanical properties. Then, (B) 0.005 to 100 parts by weight of a pulverized resin molded product containing polyimide as a main component is blended. (B) If the blended amount of the pulverized resin molded product containing polyimide as a main component is too large, the mechanical properties are significantly lowered, which is not practical. (B) The compounding quantity of the pulverized resin molded product which has a polyimide as a main component becomes like this. Preferably it is 0.1-50 weight part.

  In the present invention, (B) the slidability of the thermoplastic resin composition is improved by mixing a pulverized product of a resin molded product containing polyimide as a main component, and good mechanical properties, moldability, and slidability are obtained. It is useful for various applications such as electrical / electronic equipment applications, automotive parts applications, aerospace applications, office equipment applications, and the like. In addition, it is possible to recycle a resin molded product mainly composed of polyimide, which is preferable from the viewpoint of the global environment.

  The following examples further illustrate the present invention.

[Reference Example 1] Production of raw polyimide resin powder 60.07 g (0.3 mol) of 4,4'-diaminodiphenyl ether was dissolved in 1.2 liters of N, N-dimethylacetamide (DMAC), and pyromellitic was added thereto. 65.44 g (0.3 mol) of acid dianhydride was gradually added. Stirring was continued for another hour after the addition was completed, and a polyamic acid solution having a ηinh (measured in DMAC at a concentration of 0.5 g / dl at 30 ° C.) of 2.5 was obtained. Next, the temperature was adjusted to 30 ° C. in a water bath, and 3.36 liters of acetone was gradually added to obtain a uniform solution. While stirring, 180 ml of acetic anhydride and 360 ml of pyridine were added to precipitate polyimide. This was filtered, washed with acetone, and then dried in air at 160 ° C. for 5 hours to obtain a polyimide resin bulk powder. The polyimide resin bulk powder had an imide ring closure rate of 80% using the infrared method.

[Reference Example 2] Manufacture of Polyimide Resin Molded Product The polyimide resin powder obtained in Reference Example 1 is compression molded with a molding plate of 50 mm × 50 mm × 3 mm at a molding pressure of 300 MPa, and sintered to obtain a resin molded product. It was. In the sintering, the temperature was gradually raised in a nitrogen atmosphere, heated to 400 ° C., held for 3 hours, and then cooled to take out the molded product. The polyimide resin bulk powder had an imide ring closure rate of 98% using the infrared method.

[Reference Example 3] Manufacture of polyimide resin pulverized product (Polyimide pulverized product-A)
The resin molded product obtained in Reference Example 1 was cut in advance with a band saw to obtain a cut piece having a shape of 3 mm × 3 mm × 8 mm. The obtained cut piece was freeze-pulverized using liquid nitrogen (-195 ° C.) using a freezer mill type 6750 manufactured by Spax Corporation. Substantially 6 minutes and 4 cycles of pulverization were performed to obtain polyimide pulverized product-A having an average particle size of 50 μm.

  The average particle size of the obtained polyimide pulverized product was measured by a laser diffraction method / scattering method using a wet method, specifically, measured by a microtrack particle size distribution measuring device MT3300EX (Nikkiso Co., Ltd.), and the median. The diameter was calculated. Hereinafter, the average particle diameters of the pulverized products -B, -C, and -D were also measured in the same manner.

(Polyimide crushed product-B, C)
The resin molded product obtained in Reference Example 1 was freeze pulverized in the same manner, and pulverized by adjusting the pulverization time to obtain pulverized products having different average particle diameters. That is, the pulverization was substantially performed for 6 minutes and 10 cycles to obtain a polyimide pulverized product-B having an average particle diameter of 10 μm. Further, the pulverization time was shortened, and pulverization was substantially performed for 6 minutes and 2 cycles to obtain a polyimide pulverized product-C having an average particle diameter of 500 μm.

[Reference Example 4] Production of pulverized polyimide film A Kapton film “200-H” manufactured by Toray DuPont Co., Ltd. was cut in advance as a polyimide film to obtain a cut piece having a shape of 3 mm × 3 mm × 8 mm. The obtained cut piece was freeze-pulverized using liquid nitrogen (-195 ° C.) using a freezer mill type 6750 manufactured by Spax Corporation. Substantially 6 minutes and 10 cycles of pulverization were performed to obtain polyimide pulverized product-D having an average particle size of 50 μm.

The materials used in the examples and comparative examples are as follows.
Thermoplastic resin (polyamide 6 resin) manufactured by Toray Industries, Inc .: Amilan CM1021T.

  (Polyamide 66 resin) manufactured by Toray Industries, Inc .: Amilan CM3001N.

(Polybutylene terephthalate resin) Toray Industries, Inc .: Toraycon 1200S
(Polyphenylene sulfide resin) manufactured by Toray Industries, Inc .: Torelina E2280
Sliding agent (molybdenum disulfide) manufactured by Daito Lubrication Co., Ltd .: LM12
(Silicon resin) manufactured by Toray Dow Corning Co., Ltd .: BY27-009
Examples 1-4, Comparative Examples 1-4
The raw material of the polyimide resin of Reference Example 1, the pulverized product-A (50 μm) as the polyimide pulverized product of Reference Example 3, the polyamide 6 resin as the thermoplastic resin of Reference Example 5, and the molybdenum disulfide as the slidability imparting agent of Reference Example 6 Were blended in the amounts shown in Table 1 using a ribbon blender, and then fed to the extruder using a gravimetric feeder. The extruder was melt-kneaded at the extrusion temperature shown in Table 1 with a TEX-44 (φ44 mm twin-screw extruder; manufactured by Nippon Steel Works) with a 4-hole strand die head to obtain pellets. Then, after drying, it was molded at the molding temperature shown in Table 1 and evaluated as follows. The results are shown in Table 1.

[Measurement of tensile strength and tensile elongation at break]
Molded under the conditions shown in Table 1, tensile test pieces (1/8 inch (3.2 mm) thickness) according to ASTM D638 were injection molded and measured under a temperature condition of 23 ° C. If the tensile strength is 40 MPa or more, it can be said that the product strength level has no practical problem, but the higher this value, the better the rigidity and the better.

[Measurement of dynamic friction coefficient and specific wear]
Using a Suzuki friction and wear tester (Orientec Co., Ltd., model EFM-III-EN), a surface pressure of 30 kgf / cm ² and a linear velocity of 10 cm / sec. The contact area was 1.0 cm ² , the counterpart material was S45C, and the dynamic friction coefficient and specific wear amount were measured. The smaller the dynamic friction coefficient, the better the slidability, and the smaller the specific wear amount, the less the resin molded product is scraped.

[Molded product color tone]
The color tone of the molded product molded under the conditions shown in Table 1 was visually observed. Molded product color tone does not necessarily affect the application of the present invention, but if it is white or light, the range of resin molded products that can be colored is widened, and the design and identification of molded parts are improved. preferable.

  From the results of Table 1, by blending a polyimide pulverized product having an average particle diameter of 50 μm with 100 parts by weight of a thermoplastic resin (polyamide 6 resin), the slidability dynamic friction coefficient and specific wear amount are improved, and mechanical properties are obtained. The decrease in tensile strength is small, and when the slidability imparting agent of Comparative Example 4: molybdenum disulfide is blended, the resin molded product is black, whereas the polyimide pulverized blend is light yellow to yellow. .

Example 5, Comparative Example 5
As the polyimide pulverized product of Reference Example 3, pulverized product-A (50 μm), pulverized product-B (10 μm), pulverized product-C (500 μm) were changed in particle size, and polyamide 6 resin was ribboned as the thermoplastic resin of Reference Example 5 After blending in the amount shown in Table 2 with a blender, melt kneading was performed at the extrusion temperature shown in Table 1 in the same manner as in Examples 1 to 4 to obtain pellets. Subsequently, after drying, it shape | molded at the shaping | molding temperature shown in Table 2, and evaluated similarly to Examples 1-4. The results are shown in Table 2.

  From the results in Table 2, even if the average particle size of the polyimide pulverized product blended with the thermoplastic resin is 50 μm, it has sufficient mechanical properties and slidability. The elongation at break was even better. On the other hand, when the average particle size of the pulverized polyimide product is as large as 500 μm, the mechanical properties are significantly lowered.

Examples 6-9, Comparative Examples 6-9
The crushed product-A (50 μm) as the polyimide pulverized product of Reference Example 3, the polyamide 66 resin, the PBT resin, and the PPS resin as the thermoplastic resin of Reference Example 5 are replaced with silicon resin as the slidability imparting agent of Reference Example 6. After blending in the amount shown in Table 3 with a blender, melt kneading was performed at the extrusion temperature shown in Table 3 in the same manner as in Examples 1 to 4 to obtain pellets. Subsequently, after drying, it shape | molded at the shaping | molding temperature shown in Table 3, and evaluated similarly to Examples 1-4. The results are shown in Table 3.

  From the results in Table 3, even if the thermoplastic resin is changed to a resin having a different melting point, the slidability is improved by blending the polyimide pulverized product. In addition, when the PBT resin of Comparative Example 8 was blended with a slidability imparting agent: silicon resin, the mechanical properties were lowered.

Example 10
After blending the pulverized product-D (50 μm) as the polyimide pulverized product of Reference Example 3 and the polyamide 6 resin as the thermoplastic resin of Reference Example 5 in the amounts shown in Table 4 in a ribbon blender, the same method as in Examples 1 to 4 The mixture was melt kneaded at the extrusion temperature shown in Table 4 to obtain pellets. Subsequently, after drying, it shape | molded at the shaping | molding temperature shown in Table 4, and evaluated similarly to Examples 1-4. The results are shown in Table 4.

  From the results in Table 4, for polyimide pulverized products to be blended with thermoplastic resins, even if pulverized from polyimide resin molded products or polyimide films, the effect is not substantially different, and mechanical properties and slidability are good. there were.

Claims (6)

(A) A resin composition obtained by mixing 0.005 to 100 parts by weight of a pulverized resin molded product having an average particle diameter of 50 μm or less, the main component of which is polyimide, with 100 parts by weight of a thermoplastic resin. . (B) The resin composition according to claim 1, wherein the resin molded product containing polyimide as a main component is a film. (B) The resin composition according to claim 1 or 2, wherein the pulverized product mainly comprising polyimide has an average particle diameter of 1 to 10 µm. (B) The resin composition according to any one of claims 1 to 3, wherein the pulverized product of the resin molded product mainly composed of polyimide is a pulverized product made of polyimide having an imide ring closure rate of 90% or more. (A) The resin composition according to any one of claims 1 to 4, wherein the thermoplastic resin is at least one selected from the group consisting of polyamide, polybutylene terephthalate, and polyphenylene sulfide. The resin molded product which consists of a resin composition in any one of Claims 1-5.