JP2003327709A - Method for manufacturing polytetrafluoroethylene- containing mixed powder, and thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a polytetrafluoroethylene- containing mixed powder which has no occurrence of a peculiar odor and an improved workability at the time of molding a thermoplastic resin composition containing a polytetrafluoroethylene mixed powder and to provide a thermoplastic resin composition containing it. <P>SOLUTION: The method for manufacturing the polytetrafluoroethylene- containing mixed powder which contains polytetrafluoroethylene (A) and an organic polymer (B) is characterized in that the method has a process of coagulating a mixed fluid dispersion containing the polytetrafluoroethylene (A) and the organic polymer (B) by using calcium acetate. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polytetrafluoroethylene-containing mixed powder and a thermoplastic resin composition.

[0002]

2. Description of the Related Art Polytetrafluoroethylene (PTF)
E) has excellent heat resistance, chemical resistance, electrical insulation, water- and oil-repellency, non-adhesiveness, self-swelling property, and the like,
Widely used in coating agents. In addition, since it has high crystallinity and low intermolecular force, it has the property of forming fibers with slight stress. When compounded with a thermoplastic resin, molding processability, mechanical properties, etc. are improved. It is also used as an additive. However, polytetrafluoroethylene is poor in dispersibility in general thermoplastic resins containing no halogen atom. Therefore, in JP-A No. 11-29679, a polytetrafluoroethylene-containing mixed powder composed of polytetrafluoroethylene particles having a particle diameter of 10 μm or less and organic polymer particles is used to provide polytetrafluoroethylene for a thermoplastic resin. Described that the thermoplastic resin with improved dispersibility of fluoroethylene and the addition of polytetrafluoroethylene-containing mixed powder has good processability and mechanical properties, and also has excellent appearance. Has been done.

[0003]

However, when a polytetrafluoroethylene-containing mixed powder produced by the method described in JP-A No. 11-29679 is used as a thermoplastic resin composition containing the polytetrafluoroethylene-containing mixed powder, it is difficult to mold Gave a peculiar odor, and the workability was not preferable. The present invention provides a method for producing a polytetrafluoroethylene-containing mixed powder which has good workability without generating a peculiar odor during molding of a thermoplastic resin composition containing the polytetrafluoroethylene-containing mixed powder. , And a thermoplastic resin composition containing the same.

[0004]

Means for Solving the Problems As a result of intensive studies in view of the above circumstances, the present inventors have found that when a mixed dispersion liquid of polytetrafluoroethylene (A) and an organic polymer (B) is solidified. By using calcium acetate as a coagulant, it is possible to obtain a polytetrafluoroethylene-containing mixed powder with good workability that does not emit an odor even when it is added to a thermoplastic resin and molded. Heading, completed the present invention.

That is, in the method for producing a polytetrafluoroethylene-containing mixed powder of the present invention, a mixed dispersion containing polytetrafluoroethylene (A) and an organic polymer (B) is coagulated with calcium acetate. It is characterized by having a process. The thermoplastic resin composition of the present invention is characterized by containing the polytetrafluoroethylene-containing mixed powder produced by the above production method.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a method for producing a polytetrafluoroethylene-containing mixed powder which is preferably used as an additive for a thermoplastic resin. The structure of the mixed powder containing polytetrafluoroethylene will be described below.

The polytetrafluoroethylene (A), which is a constituent component of the polytetrafluoroethylene-containing mixed powder, is preferably not an agglomerate having a particle size of more than 10 μm, more preferably a particle size of 0. .0
It is 5 to 1.0 μm. If only polytetrafluoroethylene (A) aggregates to form an aggregate of 10 μm or more, it is not preferable from the viewpoint of dispersibility in the thermoplastic resin.
In addition, as the polytetrafluoroethylene (A), a commercially available product may be used, or a product obtained by polymerizing a tetrafluoroethylene monomer may be used.

As commercially available polytetrafluoroethylene (A), Fluoron AD-1 (Asahi Glass Co., Ltd.)
), Fluon AD-936 (manufactured by Asahi Glass Co., Ltd.), Polyflon D-1 (manufactured by Daikin Industries, Ltd.), Polyflon D
-2 (manufactured by Daikin Industries, Ltd.), Teflon (registered trademark)
30J (manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.), Fluon AD936 (manufactured by Asahi Glass Fluoropolymers Co., Ltd.)
Etc. can be mentioned. By dispersing these in water containing an emulsifier and the like, it is possible to obtain a dispersion liquid of polytetrafluoroethylene (A) having a particle size in the above-mentioned predetermined range.

As the polytetrafluoroethylene (A) obtained by polymerizing a tetrafluoroethylene monomer, for example, one obtained by emulsion polymerization using a fluorine-containing surfactant can be used. In addition, fluorine-containing olefins such as hexafluoropropylene, chlorotrifluoroethylene, fluoroalkylethylene, and perfluoroalkyl vinyl ether, and perfluoroalkyl (meth), as long as the characteristics of polytetrafluoroethylene (A) are not impaired.
Polytetrafluoroethylene copolymerized with a fluorine-containing alkyl (meth) acrylate such as acrylate can also be used. However, the content of the copolymerization component is preferably 10% by mass or less.

Monomers of the organic polymer (B), which is a constituent of the polytetrafluoroethylene-containing mixed powder, include styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene and o-chloro. Styrene-based monomers such as styrene, p-methoxystyrene, o-methoxystyrene, 2,4-dimethylstyrene, α-methylstyrene; methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate. , Butyl methacrylate, 2-ethylhexyl acrylate,
(Meth) acrylate monomers such as 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate. A vinyl cyanide monomer such as acrylonitrile or methacrylonitrile; vinyl methyl ether,
Vinyl ether type monomers such as vinyl ethyl ether; Vinyl carboxylate type monomers such as vinyl acetate and vinyl butyrate;
Examples thereof include olefin-based monomers such as ethylene, propylene and isobutylene; diene-based monomers such as butadiene, isoprene and dimethylbutadiene.
They may be used alone or in combination of two or more.

Further, when the polytetrafluoroethylene-containing mixed powder is added to the thermoplastic resin, the monomer constituting the organic polymer (B) should be appropriately selected according to the thermoplastic resin used. Is preferred. For example, when the thermoplastic resin is polymethylmethacrylate, from the viewpoint of compatibility, the (meth) acrylic acid ester-based monomer is 20% by mass.
It is preferable to use the organic polymer (B) contained above. Further, when the thermoplastic resin is polyester, it is preferable to use an organic polymer (B) containing a styrene-based monomer and a (meth) acrylic acid ester-based monomer, particularly preferably from the viewpoint of compatibility. Is an organic polymer (B) containing 1 mass% or more of a (meth) acrylic acid ester-based monomer having an epoxy group.

The particle diameter d of the organic polymer (B) is not particularly limited, but from the viewpoint of stability of the aggregated state with the polytetrafluoroethylene (A),
The range of the following formula (I) is preferable with respect to the particle diameter D of the polytetrafluoroethylene (A). 0.1D <d <10D (I)

In the present invention, the polytetrafluoroethylene-containing mixed powder will be described in detail later, but the polytetrafluoroethylene (A) dispersion and the organic polymer (B) dispersion are mixed. It is obtained by salting out and coagulating the mixed dispersion with calcium acetate, and then drying and powdering. When the polytetrafluoroethylene-containing mixed powder thus obtained is used as an additive for a thermoplastic resin, the thermoplastic resin composition is particularly excellent in molding processability and mechanical properties, and does not emit an odor and has good workability. Can be obtained.

The polytetrafluoroethylene-containing mixed powder is agglomerated particles in which the polytetrafluoroethylene (A) and the organic polymer (B) are agglomerated due to the difference in surface charge, and each is agglomerated independently. Which contains the polytetrafluoroethylene (A) and the organic polymer (B).

The agglomerated particles have a structure in which polytetrafluoroethylene (A) and the organic polymer (B) are integrated, and the morphology thereof depends on the mixing ratio of both particles and the particle size. There can be many things. That is, the polytetrafluoroethylene (A) is surrounded by the organic polymer (B), and conversely, the organic polymer (B) is surrounded by the polytetrafluoroethylene (A).
There is a form surrounded by, a form in which several particles are aggregated for one particle, and the like. The content of polytetrafluoroethylene (A) in the polytetrafluoroethylene-containing mixed powder is 0.1% by mass to 90% by mass.
Is preferred.

An example of the method for producing the polytetrafluoroethylene-containing mixed powder of the present invention will be described below. For example, first, a monomer that constitutes the organic polymer (B) is charged into a reaction vessel, an emulsifier is further added, and emulsion polymerization is performed to prepare a dispersion liquid of the organic polymer (B). .
The emulsifier is not particularly limited, and examples thereof include alkenyl succinate dipotassium, sodium 1,4-dicyclohexyl sulfonate, sodium dioctyl sulfosuccinate, sodium laurate, sodium dodecylbenzene sulfonate, sodium alkyldiphenyl ether disulfonate, and the like. Among them, dipotassium alkenylsuccinate, sodium 1,4-dicyclohexylsulfonate, sodium dioctylsulfosuccinate and sodium laurate are preferable. On the other hand, in a separate reaction vessel, a tetrafluoroethylene monomer is emulsion-polymerized using a fluorine-containing surfactant to obtain polytetrafluoroethylene (A).
A dispersion liquid is prepared.

In the present invention, the polytetrafluoroethylene (A) dispersion prepared as described above is mixed with the organic polymer (B) dispersion to prepare a mixed dispersion, which is then mixed with acetic acid. Powdering can be performed by adding the mixed dispersion liquid to hot water in which calcium is dissolved, salting out, coagulating and then drying. Here, the amount of calcium acetate used is not limited, but calcium acetate 0.1-10.
It is preferable to use 0 part by mass.

As a method for producing a polytetrafluoroethylene-containing mixed powder other than the above, in a mixed dispersion liquid in which a dispersion liquid of polytetrafluoroethylene (A) and a dispersion liquid of an organic polymer (B) are mixed. Then, a monomer having an ethylenically unsaturated bond is emulsion-polymerized, and this is put into hot water in which calcium acetate is dissolved, salted out, coagulated, and dried to obtain a powder.

As the ethylenically unsaturated monomer, styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene, o-chlorostyrene, o-chlorostyrene, etc. may be used depending on the use of the polytetrafluoroethylene-containing mixed powder. Styrene-based monomers such as p-methoxystyrene, o-methoxystyrene, 2,4-dimethylstyrene, α-methylstyrene; methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, methacryl. Butyl acid, 2-ethylhexyl acrylate,
Acrylic ester monomers such as 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; vinyl methyl ether , Vinyl ether type monomers such as vinyl ethyl ether; vinyl carboxylate type monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; dienes such as butadiene, isoprene, prene and dimethyl butadiene It can be selected from among the system monomers. These monomers can be used alone or in combination of two or more.

As described above, according to the method for producing a polyfluoroethylene-containing mixed powder of the present invention using calcium acetate as a coagulant, when it is used as an additive for a thermoplastic resin, it is particularly possible to obtain molding processability and mechanical properties. It is possible to obtain a thermoplastic resin composition which is excellent in workability and does not emit odor and has good workability.

The thermoplastic resin composition containing the polytetrafluoroethylene-containing mixed powder produced as described above and a thermoplastic resin will be described below.

As the thermoplastic resin, polyolefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate (PE
T), polyethylene naphthalate, polycyclohexane terephthalate, polybutylene terephthalate (PB
T), polyester resin such as polybutylene naphthalate, polycarbonate (PC), butadiene rubber graft copolymer (for example, ABS resin), acrylic rubber graft copolymer, silicone-acrylic composite rubber graft copolymer, ethylene propylene rubber Graft copolymer,
Styrene resin such as HIPS, AS, vinyl chloride resin,
Polyacetal resin, polyphenylene sulfide resin, polyphenylene ether resin (PPE), polyamide resin such as nylon 6 and nylon 66 (PA), PMM
Acrylic resin such as A, PET / PBT, PC / PBT,
PBT / ABS, PC / ABS, PA / ABS, PPE
Although / PBT, PPE / HIPS, PPE / PA, etc. are mentioned, a polyolefin resin is preferable and a polypropylene resin is more preferable.

Examples of the polyolefin resin include polypropylene, polyethylene, poly-1-butene, polyisobutylene, a random or block copolymer of propylene and ethylene and / or 1-butene in an arbitrary ratio, and ethylene and propylene. Ethylene-propylene-with an arbitrary ratio and a diene component of 50% by mass or less
Monomers other than olefins having an ethylenically unsaturated bond, such as diene terpolymer, polymethylpentene, ethylene or propylene and 50 mass% or less of vinyl acetate, (meth) acrylic acid alkyl ester, and aromatic vinyl compound. And a random, block or graft copolymer with

Specific examples of preferable polyolefins include a propylene-based polyolefin containing 50% by mass or more of propylene as a monomer, and 100 parts by mass of a propylene-based polyolefin containing 50% by mass or more of propylene as a monomer. 50% by mass of ethylene as body
Ethylene-based polyolefin containing 0.1 to 100
Mixtures with parts by weight, especially ASTM D123
When the melt flow rate according to No. 8 is 10 g / 10 minutes or less, the melt tension is high and the workability is excellent, which is preferable. The melt flow rate of polypropylene is measured at 230 ° C. under a load of 2.16 kg, and that of polyethylene is measured at 190 ° C. under a load of 2.16 kg according to ASTM D1238.

The blending amount of the polytetrafluoroethylene-containing mixed powder is 0.001 to 50 parts by mass with respect to 100 parts by mass of the thermoplastic resin. In that case, the blending amount of polytetrafluoroethylene (A) is 0.0001 to 100 parts by mass of the thermoplastic resin.
It is preferably in the range of 40 parts by mass.

The thermoplastic resin composition obtained by adding the polytetrafluoroethylene-containing mixed powder to the thermoplastic resin has an increased tension during melting during its processing, and has a removability during calendering and a thermoformability during thermoforming. Alternatively, the drawdown of the molten resin during blow molding, the open cell formation of cells during foam molding, and the like are improved, and the workability such as calendering, thermoforming, blow molding, and foam molding is improved. Further, the discharge amount at the time of extrusion molding and the surface condition of extrusion molded products such as sheets and films are improved, and extrusion processability is improved.

Further, the thermoplastic resin composition of the present invention comprises
Fillers can be added if desired. As the filler, calcium carbonate, talc, glass fiber, carbon fiber, magnesium carbonate, mica, kaolin, calcium sulfate, barium sulfate, titanium white, white carbon, carbon black, ammonium hydroxide, magnesium hydroxide, aluminum hydroxide, etc. Is mentioned.
Among these, calcium carbonate and talc are preferable.

The blending amount of the above-mentioned filler is the thermoplastic resin 10
It is preferably 0.1 to 400 parts by mass, more preferably 1 to 350 parts by mass, and further preferably 1 to 300 parts by mass, relative to 0 parts by mass. Rigidity and heat resistance are improved by the blending of this filler, and workability such as prevention of sticking to the roll surface in calendering is improved.
Cost reduction can be achieved. If the blending amount of the filler is less than 0.1 parts by mass, the effect of improving the rigidity is not sufficient, and if it is more than 400 parts by mass, the surface property tends to deteriorate.

If desired, additives such as stabilizers, lubricants, flame retardants and the like can be added to the thermoplastic resin composition of the present invention. As a stabilizer, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-]
Hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] and other phenolic stabilizers, tris (monononylphenyl) phosphite, tris ( Examples thereof include phosphorus-based stabilizers such as 2,4-di-t-butylphenyl) phosphite and sulfur-based stabilizers such as dilaurylthiodipropionate.

Examples of the lubricant include sodium, calcium or magnesium salts of lauric acid, palmitic acid, oleic acid or stearic acid.

Examples of the flame retardant include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl phenyl phosphate, octyl diphenyl phosphate, diisopropylphenyl phosphate, Tris. Phosphoric ester compounds such as (chloroethyl) phosphate, alkoxy-substituted bisphenol A bisphosphate, hydroquinone bisphosphate, resorcin bisphosphate, polyphosphates such as trioxybenzene triphosphate, tetrabromobisphenol A, decabromodiphenyl oxide, hexabromocyclododecane , Octabromodiphenyl ether, bistri Lomophenoxyethane, ethylene bistetrabromophtylimide, tribromophenol, various halogenated epoxy oligomers obtained by reaction of halogenated bisphenol A with epihalohydrin, carbonate oligomer having halogenated bisphenol A as a constituent, halogenated polystyrene, Examples thereof include halogen-containing compounds such as chlorinated polyolefins and polyvinyl chloride, metal hydroxides, metal oxides, sulfamic acid compounds and the like.

The thermoplastic resin composition of the present invention contains a thermoplastic resin and a polytetrafluoroethylene-containing mixed powder, and is obtained by mixing a filler and other additives, if necessary. . As a mixing method, conventionally well-known methods such as extrusion kneading and roll kneading are used. It is also possible to carry out multi-stage mixing such that a part of the thermoplastic resin is mixed with the polytetrafluoroethylene-containing mixed powder to prepare a masterbatch, and then the remaining thermoplastic resin is further added and mixed.

The processing method of the thermoplastic resin composition is as follows:
Examples include calender molding, extrusion molding, thermoforming, blow molding, injection molding, foam molding and melt spinning. Further, useful molded articles obtained by using the thermoplastic resin composition of the present invention include a sheet, a film, a thermoformed body, a hollow molded body, an injection molded body, a foamed molded body,
A fiber etc. can be mentioned.

As explained above, according to the thermoplastic resin composition of the present invention, the polytetrafluoroethylene (A)
Because of excellent dispersibility, it is possible to obtain a molded product excellent in workability, rigidity, surface appearance and the like.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In each Example and Comparative Example, "part" means "part by mass",
"%" Indicates "mass%".

(Example 1) Dodecyl methacrylate 50
Part, 45 parts of methyl methacrylate, and 5 parts of methyl acrylate were added to a mixed solution of cumene hydroxyperoxide.
3 parts were dissolved. As an emulsifier for this, sodium dodecylbenzene sulfonate (“NEOPEREX F-2
5 ", manufactured by Kao Co., Ltd.) was added with a mixed solution of 2.0 parts in terms of solid content and 300 parts of distilled water.
After stirring for 5 minutes at 000 rpm, add 2 to the homogenizer.
It was passed twice at a pressure of 0 MPa to obtain a stable preliminary dispersion liquid.
This was placed in a flask equipped with a stirrer, a cooler, a thermocouple, a nitrogen inlet, and a reagent dropping device, and heated to 60 ° C. in a water bath under a nitrogen stream. Ferrous sulfate 0.0004 parts, ethylenediaminetetraacetic acid disodium 0.0012 parts, L-
0.2 part of (+)-ascorbic acid was dissolved in 5 parts of distilled water and added to initiate polymerization, which was held for 3 hours to obtain a dispersion liquid of the organic polymer (B). The solid content concentration of the dispersion liquid of the organic polymer (B) was 25.2%, the particle size distribution showed a single peak, and the mass average particle size was 180 nm. Also,
83.3 parts of Fluon AD936 (manufactured by Asahi Glass Fluoropolymers Co., Ltd.) (concentration of solid content 63.0%, containing 5% of polyoxyethylene alkylphenyl ether with respect to polytetrafluoroethylene), distilled water 116 .7
Parts were added to obtain a polytetrafluoroethylene (A) dispersion having a solid content of 26.2%. The dispersion liquid of polytetrafluoroethylene (A) contains 25% polytetrafluoroethylene and 1.2% polyoxyethylene alkylphenyl ether. The particle size of polytetrafluoroethylene (A) in the polytetrafluoroethylene (A) dispersion was 0.3 μm. 120 parts of the polytetrafluoroethylene (A) dispersion (70 parts of polytetrafluoroethylene) and 277.8 parts of the organic polymer (B) dispersion (dodecyl methacrylate / methyl methacrylate copolymer 50 parts). The mixed dispersion liquid obtained by mixing and is mixed with 5 parts of calcium acetate in hot water at 90 ° C. 400
100 parts of polytetrafluoroethylene-containing mixed powder was obtained by separating the solid matter, filtering and drying.

(Example 2) Dodecyl methacrylate 35
Parts, 31.5 parts of methyl methacrylate, and 3.5 parts of methyl acrylate were dissolved 0.3 parts of cumene hydroxyperoxide. As an emulsifier, a mixed solution of 2.0 parts of sodium dodecylbenzenesulfonate (“Neoperex F-25”, manufactured by Kao Corporation) in solid content conversion and 200 parts of distilled water was added to the homomixer. After stirring at 10,000 rpm for 5 minutes, the homogenizer was passed twice at a pressure of 20 MPa to obtain a stable preliminary dispersion liquid. Stirrer, cooler, thermocouple, nitrogen inlet,
The flask was placed in a flask equipped with a reagent dropping device. There 8
Fluoron AD936 (manufactured by Asahi Glass Fluoropolymers Co., Ltd.) (3.3 parts) (solid content 63.0%, containing 5% polyoxyethylene alkyl phenyl ether based on polytetrafluoroethylene), and distilled water 116 0.7 part was added, and 120 parts of a polytetrafluoroethylene (A) dispersion having a solid content of 26.2% was added, and the mixture was heated to 60 ° C. in a water bath under a nitrogen stream. The polytetrafluoroethylene (A) dispersion contains 25% polytetrafluoroethylene and 1.2% polyoxyethylene alkylphenyl ether. The particle size of polytetrafluoroethylene (A) in the polytetrafluoroethylene (A) dispersion was 0.3 μm. Then
0.0004 parts of ferrous sulfate, 0.0012 parts of disodium ethylenediaminetetraacetate, and 0.2 parts of L-(+)-ascorbic acid were dissolved in 5 parts of distilled water and added to initiate polymerization, and the mixture was kept for 2 hours. , Polytetrafluoroethylene (A)
A mixed dispersion liquid containing the dispersion liquid of 1. and the dispersion liquid of the organic polymer (B) was obtained. The solid content concentration of the organic polymer (B) is 25.
At 2%, the particle size distribution showed a single peak and the mass average particle size was 200 nm. This mixed dispersion was added to 400 parts of hot water of 90 ° C. containing 5 parts of calcium acetate to separate a solid, filtered and dried to obtain 100 parts of a polytetrafluoroethylene-containing mixed powder.

Example 3 Dodecyl Methacrylate 60
Part, 35 parts of methyl methacrylate, and 5 parts of methyl acrylate were added to a mixed solution of cumene hydroxyperoxide.
3 parts were dissolved. As an emulsifier for this, sodium dodecylbenzene sulfonate (“NEOPEREX F-2
5 ", manufactured by Kao Co., Ltd.) was added with a mixed solution of 2.0 parts in terms of solid content and 300 parts of distilled water.
After stirring for 5 minutes at 000 rpm, add 2 to the homogenizer.
It was passed twice at a pressure of 0 MPa to obtain a stable preliminary dispersion liquid.
This was placed in a flask equipped with a stirrer, a cooler, a thermocouple, a nitrogen inlet, and a reagent dropping device, and heated to 60 ° C. in a water bath under a nitrogen stream. Ferrous sulfate 0.0004 parts, ethylenediaminetetraacetic acid disodium 0.0012 parts, L-
0.2 part of (+)-ascorbic acid was dissolved in 5 parts of distilled water and added to initiate polymerization, which was held for 3 hours to obtain a dispersion liquid of the organic polymer (B). The solid content concentration of the dispersion liquid of the organic polymer (B) was 25.1%, the particle size distribution showed a single peak, and the mass average particle size was 170 nm. Also,
83.3 parts of Fluon AD936 (manufactured by Asahi Glass Fluoropolymers Co., Ltd.) (concentration of solid content 63.0%, containing 5% of polyoxyethylene alkylphenyl ether with respect to polytetrafluoroethylene), distilled water 116 .7
Parts were added to obtain a polytetrafluoroethylene (A) dispersion having a solid content of 26.2%. The dispersion liquid of polytetrafluoroethylene (A) contains 25% polytetrafluoroethylene and 1.2% polyoxyethylene alkylphenyl ether. The particle size of polytetrafluoroethylene (A) in the polytetrafluoroethylene (A) dispersion was 0.3 μm. 120 parts of the polytetrafluoroethylene (A) dispersion (50 parts of polytetrafluoroethylene) and 199.2 parts of the organic polymer (B) dispersion (50 parts of dodecyl methacrylate / methyl methacrylate copolymer) And were placed in a separable flask equipped with a stirring blade, a condenser, a thermocouple, and a nitrogen inlet, and stirred under a nitrogen stream for 1 hour. afterwards,
The system was heated to 80 ° C., stirred for 1 hour, and then ferrous sulfate (I
I) 0.001 part, disodium ethylenediaminetetraacetate 0.003 part, L-(+)-ascorbic acid 0.1
Part, and a mixed solution of 60.8 parts of distilled water are added, and a mixed solution of 19 parts of methyl methacrylate, 1 part of methyl acrylate and 0.4 parts of cumene hydroxyperoxide is added dropwise over 1 hour, and the internal temperature is measured after the addition is completed. Was maintained at 80 ° C. for 1 hour to complete the radical polymerization. Separation of solids was not observed through a series of operations, and a uniform mixed dispersion was obtained. This mixed dispersion was added to 400 parts of hot water of 90 ° C. containing 5 parts of calcium acetate to separate a solid, filtered and dried to obtain 100 parts of a polytetrafluoroethylene-containing mixed powder.

<Evaluation Test> As a polyolefin, homopolypropylene pellets (melt flow rate 5.0 g
/ 10 minutes), and this is used in Examples 1-3 and Comparative Examples 1-6.
After hand blending with the polytetrafluoroethylene-containing mixed powder obtained in step 1 in the proportions shown in Table 1, a twin-screw extruder (“ZSK30”, WERNER & PFLEIDERE
(Manufactured by R Co., Ltd.) was melt-kneaded at a barrel temperature of 200 ° C. and a screw rotation speed of 200 rpm, and shaped into pellets. The odor of the obtained pellets was compared. As an odor evaluation standard, 1 was given when no odor was found and was excellent in workability, and 5 was given when it emitted an odor and was inferior in workability.
Was evaluated in 5 steps. The results are shown in Table 1. Homopolypropylene pellets containing no polytetrafluoroethylene-containing mixed powder were added to the twin-screw extruder (“ZSK30”, WERNER & PPLEID) as described above.
(Manufactured by ERER) was melt-kneaded at a barrel temperature of 200 ° C. and a screw rotation speed of 200 rpm and shaped into pellets, and the odor of the obtained pellets was set to 1 (Test Example 1).

[0040]

[Table 1]

The polytetrafluoroethylene-containing mixed powders obtained in Examples 1 to 3 using calcium acetate as a coagulant, when blended with a polyolefin to form a thermoplastic resin composition, do not emit an odor and work. A thermoplastic resin composition could be obtained with good properties.

[0042]

EFFECTS OF THE INVENTION According to the method for producing a polytetrafluoroethylene-containing mixed powder of the present invention, when added to a thermoplastic resin and molded, it can be molded with good workability without generating an odor. . Further, according to the thermoplastic resin composition of the present invention, since the polytetrafluoroethylene (A) is excellent in dispersibility without generating an odor,
A molded product excellent in workability, rigidity, surface appearance, etc. can be obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Osuka             20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayo             Otake Office F-term (reference) 4F070 AA12 AA13 AA15 AA18 AA24                       AA25 AA28 AA29 AA32 AA34                       AA40 AE14 AE28 CB01 DA32                 4J002 AC03X AC06X BB03X BB03Y                       BB05Y BB12X BB12Y BB15Y                       BB16X BC03X BC03Y BC08X                       BC09X BD05Y BD15W BF02X                       BG04X BG05X BG06Y BG10X                       BN00Y BP02Y BP03Y BQ00X                       CB00Y CF03Y CF05Y CF08Y                       CG01Y CH07Y CL01Y CL03Y                       CN03Y

Claims (2)

[Claims] 1. A method for producing a polytetrafluoroethylene-containing mixed powder containing polytetrafluoroethylene (A) and an organic polymer (B), comprising: polytetrafluoroethylene (A) and an organic polymer. A method for producing a polytetrafluoroethylene-containing mixed powder, comprising the step of coagulating a mixed dispersion liquid containing the coalesced product (B) with calcium acetate. 2. A thermoplastic resin composition, comprising the polytetrafluoroethylene-containing mixed powder produced by the production method according to claim 1.