JPH0574544B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to injection molding compositions and methods of use. More specifically, the present invention relates to injection molding compositions and methods of using ceramic powders and metal powders. [Prior Art] Conventionally, a methacrylic ester copolymer and an ethylene-vinyl acetate copolymer or a methacrylic ester copolymer and a low-density polyethylene have been used as an injection molding composition, for example, a metal powder injection molding composition. Some are used as binders. (Unexamined Japanese Patent Publication No. 59-229403). [Problems to be Solved by the Invention] However, this method requires high temperature and a long time to remove organic matter from the molded article (hereinafter abbreviated as degreasing). [Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive studies to obtain an injection molding composition that lowers the temperature at which a molded article is degreased and shortens the degreasing time. did. That is, the present invention comprises ceramic powder and/or metal powder (a), an organic binder (b) consisting of polyether (b1) and the following thermoplastic resin (b2), and optionally a lubricant (c) as an additive. and/or a plasticizer (d) (first invention); and injection molding using this injection molding composition, and then heating rate: 1 to 100. °C/hr, maximum heating temperature: 230~
This is a method of using an injection molding composition (second invention) in which a molded article is obtained by degreasing and sintering at 400° C. and heating maximum temperature holding time: 0 to 10 hours. Thermoplastic resin (b2): one or more unsaturated polymerizable thermoplastic resins selected from the following. Acrylic resin (excluding unsaturated hydrocarbon-acrylic copolymer resin) Unsaturated hydrocarbon resin selected from polyethylene, chlorinated polyethylene, polybutene, polyisobutylene, polystyrene, polyα-methylstyrene, and styrene copolymer Vinyl alcohol resin Halogen-containing vinyl resin Nitrogen-containing vinyl resin In the present invention, the polyether has the general formula R ₁ [-(AO)- _o R ₂ ] _n (1) (wherein R ₁ is an active hydrogen atom Residue of the containing compound; R ₂ is a hydrogen atom, an alkyl group, an aromatic hydrocarbon group, or an acyl group; A is an alkylene group having 1 to 4 carbon atoms or a 2-carbon group having an aryl group in the side chain
~4 alkylene group. n is an integer such that the molecular weight of the compound of general formula (1) is 10 million to 10 million. m is 1-8. ) can be mentioned. In the general formula (1), examples of the active hydrogen atom-containing compound constituting the residue of the active hydrogen atom-containing compound _R1 include water, alcohols such as low molecular weight polyols (ethylene glycol, propylene glycol, 1,3- or 1- , 4-butanediol,
1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, seurose, etc.) and monohydric alcohols [aliphatic (1 to 20 carbon atoms) or aromatic monohydric alcohol, etc.], phenols such as polyvalent phenols [such as bisphenols such as bisphenol A], and monovalent phenols [phenol, naphthol; phenols having an alkyl group (1 to 12 carbon atoms) or an aryl group, e.g. octylphenol, nonylphenol, dodecylphenol and phenylphenol]; amines such as alkanolamines;
Aliphatic or aromatic polyamines (ethylenediamine, diethylenetriamine, etc.) and aliphatic monoamines [mono- or dialkyl (1 to 1 carbon atoms)
20) amines, etc.]. Among the active hydrogen atom-containing compounds, preferred are water and low-molecular polyols, and particularly preferred are ethylene glycol and propylene glycol. In general formula (1), the alkyl group in R ₂ is:
Examples of alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, hexyl, octyl and decyl groups. Aromatic hydrocarbon groups include aryl groups (phenyl group, naphthyl group, etc.); arylalkyl groups (benzyl group,
phenethyl group, etc.); alkylaryl group (octylphenyl group, nonylphenyl group, etc.). Examples of the acyl group include acyl groups derived from carboxylic acids having 2 to 20 carbon atoms. Among R ₂ , preferred are a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferred are a hydrogen atom, a methyl group, and an ethyl group. Examples of the alkylene group having 1 to 4 carbon atoms in A include methylene group, ethylene group, propylene group, and butylene group, and examples of the alkylene group having 2 to 4 carbon atoms having an aryl group in the side chain include phenyl. Examples include ethylene group. The n A's may be the same or different. Among A, preferred are an ethylene group, a propylene group, a butylene group, and a combination of an ethylene group and a propylene group, and more preferred is an ethylene group. n is preferably the molecular weight of the compound of general formula (1)
It is an integer between 5000 and 5 million. Specific examples of the polyether represented by the general formula (1) include alkylene (2 to 4 carbon atoms) adducts of the active hydrogen atom-containing compound or ring-opening polymers of alkylene oxide (2 to 4 carbon atoms) [polyethylene oxide (molecular weight usually 60 to 4 million), polypropylene oxide (molecular weight usually 1000 to 4 million)
5000), polytetramethylene glycol (molecular weight usually 1000 to 3000), ethylene oxide-propylene oxide copolymer (molecular weight usually 2000 to 3000),
20,000)] and ring-opening polymers of cyclic formal [polyoxymethylene (molecular weight usually 3,000 to 100,000)]
etc.] and mixtures of two or more of these. Among these, polyethylene oxide, polypropylene oxide and ethylene oxide-propylene oxide copolymer are preferred, and polyethylene oxide is more preferred. For thermoplastic resin (b2), the general formula

[Chemical formula] (wherein, X is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aromatic hydrocarbon group, a cyano group, or a halogen atom; Hydrogen group, carboxylic acid ester group,
It is a cyano group, an amide group, or a halogen atom. )
Examples include polymers of vinyl monomers shown in In general formula (2), the alkyl group having 1 to 4 carbon atoms in X is a methyl group, an ethyl group, a propyl group,
Examples include butyl group. Examples of the aromatic hydrocarbon group include aryl groups (phenyl group, naphthyl group, etc.), arylalkyl groups (benzyl group, phenethyl group, etc.), and alkylaryl groups (methylphenyl group, ethyl phenyl group, etc.). Among X, preferred are a hydrogen atom, an alkyl group and a cyano group, and more preferred is a methyl group. Examples of the alkyl group having 1 to 15 carbon atoms in Y include a methyl group, an ethyl group, a butyl group, an octyl group, and a dodecyl group. Examples of aromatic hydrocarbon groups include aryl groups (phenyl group, naphthyl group, etc.), arylalkyl groups (benzyl group,
phenethyl group, etc.), and alkylaryl groups (methylphenyl group, ethyl phenyl group, etc.). Carboxylic acid ester group (-COOR group or

[Formula] R is an alkyl group, etc.), an alkyl ester group (methyl ester group, ethyl ester group, butyl ester group, octyl ester group, dodecyl ester group, octadecyl ester group, etc.), a cycloalkyl ester group (cyclohexyl ester group, etc.) ), hydroxyalkyl ester groups (hydroxyethyl ester groups, etc.),
Examples include N,N-dialkylamino(alkoxy)alkyl ester groups (such as N,N-dimethylaminoethyl ester groups). As an amide group,

[Formula] (R ₆ and R ₇ are hydrogen atoms or alkyl groups having 1 to 4 carbon atoms). Among Y, preferred are methyl group, phenyl group, and carboxylic acid ester group, and more preferred is carboxylic acid ester. The thermoplastic resin (b2) is one or more unsaturated polymerizable thermoplastic resins selected from the following. Specific examples thereof are as follows. Acrylic resins (excluding unsaturated hydrocarbon-acrylic copolymer resins): polyacrylic esters (polymethyl acrylate, polybutyl acrylate, etc.), butyl acrylate-acrylonitrile copolymer, methyl acrylate-acrylamide copolymer, ethyl acrylate-2-chloroethyl vinyl ether copolymer, methyl acrylate-acrylic acid copolymer, polymethacrylate ester (polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate,
Polycyclohexyl methacrylate, methyl methacrylate-butyl methacrylate copolymer, butyl methacrylate-octadecyl methacrylate copolymer, methyl methacrylate-hydroxyethyl methacrylate copolymer, butyl methacrylate-N,N-dimethyl methacrylate (aminoethyl copolymers, etc.) Unsaturated hydrocarbon resins selected from polyethylene, chlorinated polyethylene, polybutene, polyisobutylene, polystyrene, polyα-methylstyrene, and styrene copolymers (specific examples of styrene copolymers include , styrene-acrylonitrile copolymer, etc.) Vinyl alcohol resin: polyvinyl acetate,
Polyvinyl acetal (polyvinyl formal, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, polyvinyl hexylal, etc.), polyvinyl alcohol, polyvinyl ether (polyvinyl methyl ether, polyvinyl butyl ether, etc.), etc. Halogen-containing vinyl resin: polyvinyl chloride,
Vinyl chloride-vinyl acetate copolymer, vinyl chloride-methyl acrylate copolymer, vinyl chloride-acrylonitrile copolymer, vinyl chloride-ethylene copolymer, polyvinylidene chloride, poly(4-fluoroethylene), poly(3-fluoroethylene) Nitrogen-containing vinyl resins: polyacrylonitrile, polymethacrynitrile, methyl polycyanoacrylate, polyvinylidene cyanide, etc. These thermoplastic resins can be used as a mixture of two or more types. I can do it. Among these, polyisobutylene, polymethacrylic acid ester and polyα-methylstyrene are preferred, and polymethacrylic acid ester is more preferred. As polymethacrylic acid ester, the general formula

[Formula, R ₃ is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, or Z(-OZ) _-k
OH or

A group represented by the formula (where Z is an alkylene group having 1 to 4 carbon atoms,
R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms. k,
l is an integer from 0 to 5. )]. Among the polymethacrylic esters, polyalkyl methacrylate is preferred, and polyalkyl methacrylate in which R ₃ is an alkyl group having 1 to 8 carbon atoms is more preferred. Ceramic powders include oxides (aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, mullite, cordierite, beryllium oxide, magnesium oxide, barium titanate, etc.), carbides (silicon carbide, boron carbide, aluminum carbide, carbide, etc.) tungsten, titanium carbide,
Zirconium carbide, hafnium carbide, chromium carbide, vanadium carbide, carbon, etc.), nitrides (silicon nitride, aluminum nitride, boron nitride, titanium nitride, etc.), silicides (molybdenum disilicide, etc.), sulfides (cadmium sulfide, sulfide, etc.) zinc, etc.)
and mixtures of two or more of these. The particle size of ceramic powder is usually 0.01 μm ~
100 μm, preferably 0.1 μm to 50 μm. Metal powders include iron powder (carbonyl iron, atomized iron, ring iron, etc.), nickel powder (carbonyl nickel, etc.), aluminum powder, copper powder, titanium powder, zirconium powder, zinc powder, chromium powder, molybdenum powder, tungsten. powder, beryllium powder, germanium powder and alloy powder (iron-nickel alloy,
In addition to metal powders such as stainless steel, iron-silicon alloys, iron-boron alloys, etc., non-metallic powders such as silicon powder and boron powder are also included. The particle size of the metal powder is usually 0.1 μm to 100 μm, preferably 1 μm to 50 μm. An alloy of ceramic powder and metal powder can also be used. Examples of this alloy include tungsten carbide-cobalt alloy, tungsten carbide-titanium carbide-cobalt alloy, titanium carbide-vanadium carbide-iron-nickel alloy, and boron carbide-iron alloy. The particle size of the alloy of ceramic powder and metal powder is usually
It is 0.1 μm to 100 μm, preferably 0.5 μm to 100 μm. Examples of plasticizers include phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, phthalate). dilauryl acid, dicyclohexyl phthalate, butyl benzyl phthalate, etc.), aliphatic monobasic acid esters (butyl oleate, glycerin monooleate, etc.), aliphatic dibasic acid esters (dibutyl adipate, di-n-adipate, etc.) hexyl, dioctyl adipate, di-2 adipate
-Ethylhexyl, diisodecyl adipate, dialkyl adipate (dihexyl, dioctyl,
didecyl diglycol adipate, di-2-ethylbutyl azelate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, dioctyl sebacate, etc.), dihydric alcohol esters (diethylene glycol) dibenzoate, triethylene glycol di-2-ethyl butyrate, etc.), oxyacid esters (methyl acetyl ricinolate, butyl acetyl ricinoleate, butylphthalyl butyl glycolate, acetyl triethyl citrate, acetyl tributyl citrate, etc.),
Phosphate esters (triethyl phosphate, tributyl phosphate, trioctyl phosphate, trichloroethyl phosphate, tricresyl phosphate, tributoxyethyl phosphate, trisdichloropropyl phosphate, tris-(β-chloropropyl) phosphate, phosphoric acid triphenyl, octyl diphenyl phosphate, trisisopropylphenyl phosphate, etc.), maleic acid esters (dibutyl maleate, di-2-maleate, etc.)
ethylhexyl, etc.), dibutyl fumarate, trialkyl trimellitate (the number of carbon atoms in the alkyl is
Usually 4-11), tris-2-ethylhexyl trimellitate. Polyoxyalkylene benzoate esters (polyoxyethylene benzoate, etc.), polyester plasticizers (propylene glycol polyadipate, etc.), epoxy plasticizers (epoxy fatty acid esters, etc.), stearic acid plasticizers, chlorinated paraffin, etc., and these A mixture of two or more types is mentioned. Among these, phthalate esters,
These include aliphatic dibasic acid esters and polyoxyalkylene benzoate esters, and more preferred are dibutyl phthalate, dioctyl phthalate, and butylbenzyl phthalate. As lubricants, aliphatic hydrocarbons (liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax, and their partial oxides, fluorides, chlorides, etc.), higher aliphatic alcohols (lauryl alcohol, Stearyl alcohol, oleyl alcohol, mixed aliphatic alcohols, etc.), higher fatty acids [lauric acid, stearic acid, mixed fatty acids (beef tallow,
fatty acids from fish oil, coconut oil, soybean oil, rapeseed oil, rice bran oil, etc.), fatty acid amides (oleic acid amide, stearic acid amide, methylene-bis-stearamide, ethylene-bis-stearamide, etc.), metal soaps ( barium stearate,
Calcium stearate, zinc stearate, aluminum stearate, magnesium stearate, etc.), fatty acid esters [higher fatty acid esters of monohydric alcohols (butyl oleate, etc.),
Higher fatty acid [partial] esters of polyhydric alcohols (glycerin monooleate, etc.), Montan wax, etc.], and mixtures of two or more of these can be mentioned. Among these, preferred are aliphatic hydrocarbons, higher fatty acids and fatty acid esters,
More preferred are liquid paraffin, stearic acid and montan wax. In the composition of the present invention, the content of each component is
Based on the weight of the composition, (a) usually ranges from 50 to 99%, preferably from 70 to 96%. If (a) is less than 50%, the strength of the molded body and the degreased body after degreasing decreases, and the strength of the degreased body decreases to 99%.
If it exceeds this value, the shape retention force of the molded article will decrease. (b) is usually 1 to 50%, preferably 3 to 30%. If (b) is less than 1%, the shape retention of the molded product is insufficient, and if it exceeds 50%, the strength of the molded product and the degreased product after degreasing decreases. Based on the weight of organic binder, polyether (b1) is usually 0.1-70%, preferably 0.5-30%
It is. When (b1) is less than 0.1%, the moldability of the molding composition decreases, and when it exceeds 70%, the strength during molding decreases. (b2) is usually 30% to 99.9%, preferably
It is 70-99.5%. If (b2) is less than 30%, the strength during molding will decrease, and if it exceeds 99.9%, the moldability of the molding composition will decrease. (c) is usually 0 to 10%, preferably 0.5 to 5%. If (c) exceeds 10%, the strength of the molded body and the degreased body after degreasing decreases. (d) is usually 0 to 10%, preferably 0.5 to 5%. If (d) exceeds 10%, the strength of the molded body and the degreased body after degreasing decreases. The composition of the present invention is prepared by kneading abc and d in a kneader such as a plastomill, kneader, or pressure kneader, pulverizing (roughly crushing), pelletizing, and injection molding. After injection molding, it is degreased, sintered (fired), and processed to obtain a molded product. In the case of plastomills and kneaders, the kneading conditions in the above are usually 60 to 200°C, preferably 100 to 180°C, and the kneading time is usually 20 minutes to 200°C.
The time is preferably 30 minutes to 1 hour. In the case of a pressure kneader, the kneading temperature is usually 50 to 200°C, preferably 50 to 150°C, and the kneading time is usually 10 minutes to 2 hours.
Preferably it is 10 minutes to 30 minutes. Molding is performed using a regular injection molding machine (plunger type, screw type, etc.), and the injection pressure is usually 100~
^The molding temperature is usually 70 ^to 200°C, preferably 100 to 200°C. Degreasing after injection molding is usually carried out in an oxidizing, non-oxidizing or reducing atmosphere under reduced pressure, normal pressure or increased pressure, usually at 1 to 100°C/hr, preferably at 1 to 15°C/hr.
Raise the temperature to 230-400℃ at a heating rate of hr, 230-400℃
It is carried out by holding at a temperature of usually 0 to 10 hours, preferably 1 to 10 hours. Sintering (firing) is oxidation,
Carry out at 600°C to 2500°C under reduced pressure, normal pressure or increased pressure in a non-oxidizing or reducing atmosphere. Machining is not particularly necessary, but when a precision finish is required, cutting or grinding is done with a diamond cutter. [Examples] The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Parts in Examples and Comparative Examples are parts by weight, and the average particle size of the alumina powder used was 1 μm or less, and the average particle size of the stainless steel powder was 10 μm. Example 1 Using a Laboplast Mill, polybutyl methacrylate and polyethylene oxide (molecular weight 20,000) were charged and melted at 130°C and a rotor rotation speed of 30 rpm, and then alumina powder, Montan wax, and dibutyl phthalate were gradually added. In addition, after adding the entire amount, kneading was carried out for 30 minutes at 130°C and rotor rotation speed of 50 rpm. This kneaded material is pulverized to form an injection molding composition (1).
I got it. The blending ratio is shown below. Alumina powder 100 parts Polybutyl methacrylate 11.2 parts Polyethylene oxide (molecular weight 20,000) 1.8 parts Dibutyl phthalate 2.5 parts Montan wax 2.9 parts Examples 2 to 4 and Comparative Examples 1 and 2 Kneading in the same manner as in Example 1, Pulverization was performed to obtain injection molding compositions (2) to (4) of the present invention and compositions (a) and (b) of comparative examples having the following compositions. Example 2 Alumina powder 100 parts Polybutyl methacrylate 9.7 parts Polyethylene oxide (molecular weight 20,000) 3.6 parts Dibutyl phthalate 2.5 parts Montan wax 2.9 parts Example 3 Alumina powder 100 parts Polybutyl methacrylate 9.7 parts Polyethylene oxide (molecular weight 400) 3.6 parts Dibutyl phthalate 2.5 parts Montan wax 2.9 parts Example 4 Stainless steel powder 100 parts Polybutyl methacrylate 5.6 parts Polyethylene oxide (molecular weight 20,000) 0.9 parts Dibutyl phthalate 1.4 parts Montan wax 1.4 parts Comparative example 1 Alumina Powder 100 parts Polybutyl methacrylate 6.5 parts Ethylene-vinyl acetate copolymer 5.6 parts Dibutyl phthalate 2.5 parts Montan wax 2.9 parts Comparative example 2 Stainless steel powder 100 parts Polybutyl methacrylate 3.2 parts Ethylene-vinyl acetate copolymer 2.8 parts Dibutyl phthalate 1.3 parts Montan wax 1.3 parts Examples 5 to 8, Comparative Examples 3 to 6 Compositions (1) to (4) of the present invention of Examples 1 to 4 and compositions (a) of Comparative Examples 1 and 2 ) and (b) using an injection molding machine (plunger type) at an injection pressure of 600 Kg/cm ² ,
Injection molding was performed at a molding temperature of 150°C to obtain an injection molded product.
This injection molded body was degreased and sintered (fired) to obtain a molded article. The status of microcracks in this molded product,
The bulk specific gravity and relative density were investigated. Table the results.
1 and Table 2.

【table】

【table】

[Table] Explanation of Tables 1 and 2 (same as Tables 3 and 4) Γ Degreasing conditions: Temperature raised from 40℃ to 250℃ in 19 hours, 5 at 250℃
Time keeping. Cools from 250℃ to 40℃ in 7 hours. The temperature was raised from 40℃ to 400℃ in 38 hours, maintained at 400℃ for 2 hours, and cooled from 400℃ to 40℃ in 12 hours. Γ Sintering A: In air, 1600°C x 2 hours B: Under reduced pressure, 1250°C x 2 hours Γ Microcracks occurrence ○: No occurrence, ×: Occurrence Examples 9 to 12, Comparative Examples 7 and 8 Example 1 ~4 compositions of the present invention and comparative example 2
The composition was injection molded using an injection molding machine (screw type) at an injection pressure of 1500 Kg/cm ² and a molding temperature of 150° C. to obtain an injection molded article. This injection molded body was degreased and sintered (fired) to obtain a molded article. The occurrence of microcracks, bulk specific gravity, and relative density of this molded product were investigated. The results are shown in Tables 3 and 4.

【table】

【table】

[Table] [Effects of the Invention] The composition of the present invention has the following effects. The composition of the present invention can lower the degreasing temperature and shorten the degreasing time when degreasing a molded object. Almost no impurities such as carbon remain in the fired body. Injection molding yields a molded body with high density. A dense fired body can be obtained. Molded articles produced using the compositions of the invention have high relative density and high strength. Conventionally, degreasing complex-shaped injection molded bodies made of ceramic powder or metal powder required high temperatures and a long time. This was a measure that had to be taken in order to prevent cracking of the molded product caused by rapid decomposition and vaporization of organic substances such as binders. Since the composition of the present invention can be degreased at a relatively low temperature, the degreasing time can be shortened.

Claims (1)

[Claims] 1. Ceramic powder and/or metal powder (a)
, an organic binder (b) consisting of polyether (b1) and the following thermoplastic resin (b2), and if necessary a lubricant (c) and/or plasticizer as additives.
An injection molding composition comprising (d). Thermoplastic resin (b2): one or more unsaturated polymerizable thermoplastic resins selected from the following: Acrylic resin (excluding unsaturated hydrocarbon-acrylic copolymer resins) polyethylene, chlorinated polyethylene, polybutene, Unsaturated hydrocarbon resin selected from polyisobutylene, polystyrene, polyα-methylstyrene, and styrene copolymer Vinyl alcohol resin Halogen-containing vinyl resin Nitrogen-containing vinyl resin 2 (a), (b), (c) , (d) is 50-99% of (a), 1-50% of (b), and 0-10% of (c) based on the weight of the composition.
%, (d) is 0 to 10%. 3 Based on the weight of organic binder b (b1)
The composition according to claim 1 or 2, wherein (b2) is 0.1 to 70% and 30 to 99.9%. 4. The composition according to any one of claims 1 to 3, wherein (b1) has a molecular weight of 10 million to 10 million. 5 (b1) has the general formula R ₁ [-(AO)- _o R ₂ ] _n (1) (wherein, R ₁ is the residue of a compound containing an active hydrogen atom; R ₂ is a hydrogen atom, an alkyl group, an aromatic group) Hydrocarbon group or acyl group; A is an alkylene group having 1 to 4 carbon atoms or 2 carbon atoms having an aryl group in the side chain
~4 alkylene group. n is an integer such that the molecular weight of the compound of general formula (1) is 10 million to 10 million. m is 1-8. ) The composition according to claim 4, which is a compound represented by: 6 (b1) is polyethylene oxide, polypropylene oxide or ethylene oxide -
The composition according to claim 5, which is a propylene oxide copolymer. 7 (b2) has the general formula alkyl group, aromatic hydrocarbon group, carboxylic acid ester group,
It is a cyano group, an amide group, or a halogen atom. )
The composition according to any one of claims 1 to 6, which is a polymer of a vinyl monomer represented by: 8. The composition according to claim 7, wherein (b2) is a polymer of a monomer selected from the group consisting of isobutylene, methacrylic acid ester and α-methylstyrene. 9 ( _b2 ) _has the general formula
OH or a group represented by the formula (where Z is an alkylene group having 1 to 4 carbon atoms,
R ₄ and R ₅ are alkyl groups having 1 to 5 carbon atoms. k,
l is an integer from 0 to 5. )] Claim 8 is a polymer of methacrylic acid ester represented by
Compositions as described in Section. 10 Ceramic powder and/or metal powder (a)
, an organic binder (b) consisting of polyether (b1) and the following thermoplastic resin (b2), and if necessary a lubricant (c) and/or plasticizer as additives.
Injection molding is performed using an injection molding composition consisting of (d), and then heating rate: 1 to 100°C/hr, maximum heating temperature: 230 to 400°C, maximum heating temperature holding time: 0
A method of using a composition for injection molding to obtain a molded article by degreasing and sintering under conditions of ~10 hours. Thermoplastic resin (b2): One or more unsaturated polymerizable thermoplastic resins selected from the following: Acrylic resin (excluding unsaturated hydrocarbon-acrylic copolymer resin) polyethylene, chlorinated polyethylene, polybutene, Unsaturated hydrocarbon resin selected from polyisobutylene, polystyrene, polyα-methylstyrene, and styrene copolymer Vinyl alcohol resin Halogen-containing vinyl resin Nitrogen-containing vinyl resin 11 Injection molding, molding pressure: 100 to 2000 kg/ ^cm2 ,
The method of use according to claim 10, which is carried out under conditions of molding temperature: 70 to 200°C. 12. The method of use according to claim 10 or 11, wherein sintering is performed under conditions of sintering temperature: 600 to 2,500.