JP3137954B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent flame retardancy.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for flame retardancy of resin materials. For example, in the case of housing materials for OA equipment such as computers and printers, and home electric appliances such as televisions and audio equipment, there is a strong demand for flame retardancy to reduce fire damage. Further, as the weight and thickness of the device become thinner and the shape becomes more complicated, higher flame retardancy is required for the resin material. In addition, it is important that the resin does not drip (drip) particularly during combustion, in order to prevent the spread of fire in a fire.

[0003] As a method for improving the drip prevention of a thermoplastic resin composition, addition of polytetrafluoroethylene is generally well known.

[0004] However, although the flame retardancy of the thermoplastic resin is improved by the addition of polytetrafluoroethylene, the price of polytetrafluoroethylene is much higher than that of the thermoplastic resin. Even so, the price of the thermoplastic resin composition is greatly increased. In addition, polytetrafluoroethylene has poor compatibility with most thermoplastic resins, and thus easily forms aggregates in the resin composition. Agglomerates of polytetrafluoroethylene have problems that they impair the appearance of the molded product, increase the amount of addition required for the expression of flame retardancy, increase the price, and easily impair mechanical properties such as impact strength.

As described above, there is a strong demand for a technique for dispersing polytetrafluoroethylene uniformly in a thermoplastic resin and improving the flame retardancy at least in an added amount.

[0006] Therefore, the following attempts have been made to improve the flame retardancy of a thermoplastic resin composition by adding a mixture of polytetrafluoroethylene and an organic polymer.

Japanese Unexamined Patent Publication (Kokai) No. 60-258263 discloses that flame retardancy is improved by adding a powder obtained by mixing and coagulating a polytetrafluoroethylene dispersion and an aromatic vinyl polymer dispersion. It is stated to improve. JP-A-9-95
No. 583 describes that a powder obtained by polymerizing an organic monomer in the presence of a polytetrafluoroethylene dispersion has excellent handleability. JP-A-10-310707 discloses that a thermoplastic resin composition comprising a polycarbonate, an acrylonitrile-styrene-butadiene copolymer and a polyorganosiloxane-containing composite rubber-based graft copolymer has excellent flame retardancy and impact resistance. It is described.

However, even with these methods,
The price increase accompanying the addition of polytetrafluoroethylene and the improvement of dispersibility in the resin were insufficient.

[0009]

An object of the present invention is to provide a thermoplastic resin composition having excellent flame retardancy.

[0010]

The inventors of the present invention have conducted intensive studies. As a result, when a mixture of polytetrafluoroethylene and an organic polymer is added to a polycarbonate resin, the molecular weight of the polycarbonate resin is increased to increase the molecular weight. The inventors have found that the fibrillation of tetrafluoroethylene is promoted and the flame retardancy is further improved, and the present invention has been achieved.

The gist of the present invention is that the weight average molecular weight is 30,000-
2 million polycarbonate (A-1), flame retardant (B) and polytetrafluoroethylene particles and organic
And a thermoplastic resin composition comprising a polytetrafluoroethylene-containing mixed powder (C) comprising: a polycarbonate (A) having a weight average molecular weight of 30,000 to 2,000,000
-1), aromatic vinyl polymer (A-2), flame retardant (B)
And polytetrafluoroethylene particles and organic polymerization
A thermoplastic resin composition comprising a polytetrafluoroethylene-containing mixed powder (C).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate (A-1) according to the present invention has the general formula

Embedded image And a bifunctional phenol (HO-Ar-OH)
Are linked by a carbonate bond.

Examples of difunctional phenols include hydroquinone, 4,4'-dihydroxydiphenyl, 1,1
-Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane [abbreviated as bisphenol A], 1,1-bis (4-hydroxyphenyl) butane, bis (4-hydroxyphenyl) Examples thereof include sulfone and 4,4′-dihydroxydiphenyl ether, and one or more of these can be used.

The weight average molecular weight of the polycarbonate is 30,000 to 2,000,000, preferably 30,000 to 200,000, and more preferably 30,000 to 70,000. The thermoplastic resin composition obtained when the molecular weight is low has low flame retardancy.

In consideration of the mechanical properties and cost of the thermoplastic resin obtained, bisphenol A is preferred.

The aromatic vinyl polymer (A-
2) is a polymer obtained by polymerizing a monomer containing an aromatic vinyl monomer as a component. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, and p-methylstyrene. Examples of the aromatic vinyl polymer, aromatic vinyl homopolymer,
Butadiene rubber, styrene-butadiene copolymer, ethylene-propylene copolymer, aromatic vinyl polymer containing various rubbery polymers such as ethylene-propylene-diene copolymer, styrene-maleic anhydride copolymer, Examples thereof include a styrene-methyl methacrylate copolymer, a styrene-acrylonitrile copolymer, a styrene-acrylonitrile-butadiene copolymer, and a styrene-acrylonitrile-acrylate copolymer.

The polycarbonate (A-1) or the polycarbonate (A-1) and the aromatic vinyl polymer (A-2) of the present invention include polyphenylene ether, polyolefin, polyester, polyamide, polyvinyl chloride, PMMA, and various elastomers. And other thermoplastic resins such as polyoxymethylene can be used in an amount of 50% by weight or less of the whole.

The flame retardant (B) according to the present invention is a conventionally known flame retardant or a flame retardant auxiliary agent which is used in combination with a flame retardant to promote a flame retarding action. Examples include phosphorus-containing compounds, halogen-containing compounds, metal oxides, metal hydroxides, triazine compounds, red phosphorus, zirconium compounds, polyphosphate compounds, sulfamic acid compounds, and the like.

Examples of the phosphorus-containing compound include red phosphorus and a phosphoric ester compound. Phosphoric acid ester compounds have the general formula

Embedded image (However, R1, R2, R3, and R4 are a hydrogen atom or an organic group, excluding the case where R1 = R2 = R3 = R4 = H. X is a divalent or higher valent organic group. P is 0 or 1.) Q is an integer of 1 to 30. r is an integer of 0 or more.)

Examples of the organic group include an alkyl group, a cycloalkyl group and an aryl group, and various substituents can be introduced. Examples of the substituent include an alkyl group, an alkoxy group, an alkylthio group, a halogen,
Examples include an aryl group, an aryloxy group, an arylthio group, and a halogenated aryl group. One or more of these can be used, and an example of such an organic group is an arylalkoxyalkyl group. These substituents can be bonded via an oxygen atom, a sulfur atom, a nitrogen atom and the like, and an example of such an organic group is an arylsulfonylaryl group.

The divalent or higher valent organic group is defined as
A group formed by removing one or more hydrogen atoms bonded to a carbon atom, and examples thereof include an alkylene group, a phenylene group, and a derivative of a polynuclear phenol such as bisphenol. The relative positions of two or more free valences are not particularly limited. Examples of the divalent or higher valent organic group include hydroquinone, resorcinol, diphenylolmethane, diphenyloldimethylmethane, dihydroxydiphenyl, p, p'-dihydroxydiphenylsulfone, and dihydroxynaphthalene.

Examples of such phosphate ester compounds include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl phenyl phosphate, octyl diphenyl phosphate. ,
Diisopropylphenyl phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate,
Bis (2,3-dibromopropyl) -2,3-dichloropropyl phosphate, tris (2,3-dibromopropyl) phosphate, bis (chloropropyl) monooctyl phosphate, bisphenol A bisphosphate, hydroquinone bisphosphate, resorcin bisphosphate And polyphosphates such as trioxybenzene triphosphate. Red phosphorus, triphenyl phosphate, and various polyphosphates are preferable in consideration of the flame retardancy of the obtained thermoplastic resin composition.

Examples of the halogen-containing compound include tetrabromobisphenol A, decabromodiphenyl oxide, hexabromocyclododecane, octabromodiphenyl ether, bistribromophenoxyethane, ethylenebistetrabromophytylimide, tribromophenol, and halogenated bisphenol. Examples include various halogenated epoxy oligomers obtained by the reaction of A with epihalohydrin, carbonate oligomers containing halogenated bisphenol A as a constituent, halogenated polystyrene, chlorinated polyolefin, polyvinyl chloride, and the like.

Examples of metal oxides include antimony oxide such as antimony pentoxide and antimony trioxide.

Examples of the triazine compound include melamine, ethylene dimelamine, triguanamine, benzoguanamine, succinoguanamine, adiboguanamine, methylglutalogamine, melam, melon, melamine phosphate,
Melamine resin, BT resin, melamine cyanurate, ethylene dimelamine cyanurate, triguanamine cyanurate, succinoguanamine cyanurate, benzoguanamine cyanurate and the like can be mentioned.

One or more flame retardants (B) according to the present invention can be used.

The polytetrafluoroethylene-containing mixed powder (C) according to the present invention comprises polytetrafluoroethylene particles having a particle diameter of 10 μm or less and an organic polymer, and polytetrafluoroethylene has a particle diameter of 10 μm.
It is necessary that it does not form an aggregate. Furthermore, from the viewpoint of dispersibility when blended into a thermoplastic resin, the content of the polytetrafluoroethylene component needs to be 1 to 30% by weight, and the content of the organic polymer component needs to be 70 to 99% by weight. If the content of the polytetrafluoroethylene component is less than 1% by weight, the effect of improving the flame retardancy becomes insufficient, and if it exceeds 30% by weight, the surface appearance may be adversely affected.

The polytetrafluoroethylene-containing mixed powder (C) is prepared by mixing an aqueous dispersion of polytetrafluoroethylene particles having a particle diameter of 0.05 to 1.0 μm and an aqueous dispersion of organic polymer particles. To solidify or powder by spray drying, or 0.05 to 1.0 particle size
After polymerizing the monomers constituting the organic polymer in the presence of an aqueous dispersion of polytetrafluoroethylene particles having a particle diameter of 0.05 μm, the mixture is powdered by coagulation or spray drying, or a polymer having a particle diameter of 0.05 to 1.0 μm. In a dispersion obtained by mixing an aqueous dispersion of tetrafluoroethylene particles and an aqueous dispersion of organic polymer particles, it can be obtained by emulsion polymerization of a vinyl monomer, followed by coagulation or pulverization by spray drying. .

The polytetrafluoroethylene-containing mixed powder (C) according to the present invention is used to obtain a mixed powder (C) having a particle size of 0.1.
The aqueous dispersion of polytetrafluoroethylene particles having a particle size of from 0.5 to 1.0 μm is obtained by polymerizing a tetrafluoroethylene monomer by emulsion polymerization using a fluorinated surfactant.

In the emulsion polymerization of polytetrafluoroethylene particles, copolymer components such as hexafluoropropylene, chlorotrifluoroethylene, fluoroalkylethylene, and perfluoroalkylvinyl ether are contained as long as the properties of polytetrafluoroethylene are not impaired. Fluorinated olefins and fluorinated alkyl (meth) acrylates such as perfluoroalkyl (meth) acrylate can be used. The content of the copolymer component is preferably 10% by weight or less based on tetrafluoroethylene.

Commercially available raw materials for the polytetrafluoroethylene particle dispersion include Fluon AD-1 and AD-936 manufactured by Asahi Glass Fluoropolymer Co., Ltd., and Polyflon D-1 and D-2 manufactured by Daikin Industries, Ltd. Teflon 30J manufactured by the company can be cited as a representative example.

The organic polymer constituting the polytetrafluoroethylene-containing mixed powder used in the present invention is not particularly limited, but from the viewpoint of dispersibility, (A-1)
Or it is preferable that it has high affinity with (A-2).

Specific examples of the monomer for forming the organic polymer include styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, t-butylstyrene, o-ethylstyrene, p-methylstyrene and p-methylstyrene. Aromatic vinyl monomers such as chlorostyrene, o-chlorostyrene, 2,4-dichlorostyrene, p-methoxystyrene, o-methoxystyrene, 2,4-dimethylstyrene; methyl acrylate,
Methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate,
Octadecyl acrylate, octadecyl methacrylate,
(Meth) acrylate monomers such as cyclohexyl acrylate and cyclohexyl methacrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; α, β-unsaturated carboxylic acids such as maleic anhydride;
-Maleimide monomers such as -phenylmaleimide, N-methylmaleimide, N-cyclohexylmaleimide; epoxy group-containing monomers such as glycidyl methacrylate; vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether; vinyl acetate; Vinyl carboxylate monomers such as vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; and diene monomers such as butadiene, isoprene and dimethylbutadiene.
These monomers can be used alone or in combination of two or more.

Among these monomers, preferred from the viewpoint of affinity with (A-1) or (A-2) are:
Monomers containing at least 30% by weight of one or more monomers selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers can be mentioned. Particularly preferred are monomers containing at least 30% by weight of one or more monomers selected from the group consisting of styrene and acrylonitrile.

The polytetrafluoroethylene-containing mixed powder (C) used in the present invention is subjected to salting-out and coagulation by putting the aqueous dispersion thereof into hot water in which metal salts such as calcium chloride and magnesium sulfate are dissolved. It can be dried later or powdered by spray drying.

Normal polytetrafluoroethylene fine powder forms aggregates of 100 μm or more in the step of recovering as a powder from the state of a particle dispersion, so that it is difficult to uniformly disperse it in a thermoplastic resin. On the other hand, the polytetrafluoroethylene-containing mixed powder used in the present invention has extremely dispersibility in the thermoplastic resin (A) because polytetrafluoroethylene alone does not form a domain having a particle diameter of more than 10 μm. Are better. As a result, in the thermoplastic resin composition of the present invention, polytetrafluoroethylene is efficiently made into fine fibers in the thermoplastic resin, and has excellent flame retardancy and excellent surface properties.

The thermoplastic resin composition according to the present invention comprises (A)
-1) or (A-1) + (A-2), flame retardant (B)
And polytetrafluoroethylene-containing mixed powder (C)
Can be obtained by mixing.

The mixing ratio is not particularly limited, but is preferably (A-1) or (A-1) + in consideration of the flame retardancy, mechanical properties, and cost of the obtained thermoplastic resin composition.
(A-2) For 100 parts by weight, (B) 0.1 to 70 parts by weight.
Parts by weight, (C) 0.001 to 50 parts by weight, more preferably (B) 2 to 30 parts by weight, (C) 0.01 to 10 parts by weight.
Parts by weight.

Further, the ratio of the polytetrafluoroethylene-containing mixed powder (C) is increased, and a master batch mixed with (A-1) or (A-1) + (A-2) is prepared in advance. Then, the masterbatch, (A-1) or (A-1) + (A-2), and the flame retardant (B) can be mixed in a desired composition.

The method of mixing is not particularly limited, and examples thereof include generally known methods using a single-screw extruder, a twin-screw extruder, a batch kneader, a roll, or the like.

The thermoplastic resin composition according to the present invention may contain various additives such as fillers such as glass fiber, talc and mica, dyes, pigments, stabilizers and reinforcing agents.

The thermoplastic resin composition according to the present invention comprises OA
It can be used in fields where flame retardancy is required, such as housing materials for devices and home appliances.

Hereinafter, the present invention will be described with reference to examples. In Reference Examples, Examples and Comparative Examples, "parts" and "%" are "parts by weight" and "% by weight" unless otherwise specified.
Means

[0044]

EXAMPLES Various physical properties in Examples and Comparative Examples were measured by the following methods.

(1) Solids: The particle dispersion was heated at 170 ° C. for 3 hours.
It was obtained by drying for 0 minutes.

(2) Particle size distribution, weight average particle size: A solution obtained by diluting a particle dispersion with water was used as a sample solution, and a dynamic light scattering method (ELS800 manufactured by Otsuka Electronics Co., Ltd., temperature: 25 ° C., scattering angle: 90) Degree).

(3) Zeta potential: 0.0
An electrophoresis method (ELS800, manufactured by Otsuka Electronics Co., Ltd.)
At a temperature of 25 ° C. and a scattering angle of 10 °).

(4) Combustion test: It was determined by conducting a combustion test with a test piece thickness of 0.8 mm according to the UL94-V standard set by Underwriters Laboratories Corporation. A test piece was obtained by injection molding the obtained resin composition.

(5) Surface appearance: The surface appearance of the injection-molded test specimen was visually observed and judged according to the following criteria.

○: No bumps on surface X: bumps on surface Reference Example 1. Production of polytetrafluoroethylene-containing mixed powder (C-1) 300 parts of distilled water and 2 parts of sodium dodecylbenzenesulfonate were placed in a flask equipped with a stirrer, a cooler, a thermocouple, a nitrogen inlet, and a reagent dropping device. It was charged and heated to 70 ° C. in a water bath under a nitrogen stream. After dissolving 0.0004 parts of ferrous sulfate, 0.0012 parts of disodium ethylenediaminetetraacetate, and 0.8 parts of sodium formaldehyde sulfoxylate in 5 parts of distilled water and adding to the contents, 30 parts of acrylonitrile and 70 parts of styrene were added. , A mixture of 0.5 parts of cumene hydroxyperoxide was added dropwise over 3 hours, and then the mixture was heated and stirred for 1 hour to obtain an acrylonitrile-styrene copolymer particle dispersion (P-1). The solid content of P-1 is 25.1%, and the weight average particle size is 10
0 μm Surface potential was −30 mV.

As a polytetrafluoroethylene particle dispersion, Fluon AD936 manufactured by Asahi Glass Fluoropolymers Co., Ltd.
Was used. AD936 contains 5 parts of polyoxyethylene alkylphenyl ether per 100 parts of polytetrafluoroethylene, has a solid content of 63.0%, shows a single particle size distribution, a weight average particle size of 290 nm, and has a surface potential of 20 mV. To 833 parts of AD936, 1167 parts of distilled water was added to obtain a polytetrafluoroethylene particle dispersion (F-1) having a solid content of 26.2%.

239.0 parts of P-1 (acrylonitrile-styrene copolymer 60 parts) and 80 parts of F-1 (polytetrafluoroethylene 20 parts) were mixed with a stirrer, a condenser,
The flask was equipped with a thermocouple, a nitrogen inlet, and a reagent dropping device, and stirred at room temperature for 1 hour under a nitrogen stream. Thereafter, the mixture was heated to 80 ° C. in a water bath and stirred for 1 hour. Ferrous sulfate 0.00
04 parts, disodium ethylenediaminetetraacetate 0.00
12 parts and 0.8 parts of sodium formaldehyde sulfoxylate are dissolved in 5 parts of distilled water and added to the contents.
A mixture of 6 parts of acrylonitrile, 14 parts of styrene, and 0.1 part of cumene hydroxy peroxide was added dropwise over 30 minutes, and the mixture was heated and stirred for 1 hour. No solid matter was separated, and a uniform particle dispersion was obtained. The solid content of the particle dispersion was 28.6%, and the weight average particle size was 220 nm.

The particle dispersion was poured into an aqueous calcium chloride solution, the solid was separated, filtered and dried to obtain a polytetrafluoroethylene-containing mixed powder (C-1). The dried C-1 was molded using a press molding machine, an ultrathin section was collected from the molded product using a microtome, and observed with a transmission electron microscope without staining. Polytetrafluoroethylene was observed as a dark part, and no aggregate exceeding 10 μm was observed.

Reference Example 2 Production of polytetrafluoroethylene-containing mixed powder (C-2) Acrylonitrile-styrene copolymer particle dispersion (P-1) 29 used in Reference Example 1
8.8 parts (acrylonitrile-styrene copolymer 75
Parts) and 100 parts of the polytetrafluoroethylene particle dispersion (F-1) used in Reference Example 1 (25 parts of polytetrafluoroethylene) were charged into a flask equipped with a stirrer, a condenser, and a thermocouple. Stir for 1 hour at room temperature under nitrogen stream,
Thereafter, the mixture was heated to 70 ° C. in a water bath and stirred for 1 hour. No solid matter was separated, and a uniform particle dispersion was obtained. The solid content of the particle dispersion was 24.9%, and the weight average particle size was 220 nm.

The particle dispersion was poured into an aqueous calcium chloride solution, the solid was separated, filtered and dried to obtain a polytetrafluoroethylene-containing mixed powder (C-2). When observation with a transmission electron microscope was performed in the same manner as in Reference Example 1, 10
No polytetrafluoroethylene aggregates larger than μm were observed.

Reference Example 3 Production of polytetrafluoroethylene-containing mixed powder (C-3) 160 parts (40 parts of polytetrafluoroethylene) of polytetrafluoroethylene particle dispersion (F-1) used in Reference Example 1, and dodecylbenzenesulfonic acid 1. 0 parts and 70 parts of distilled water were charged into a flask equipped with a stirrer, a cooler, a thermocouple, a nitrogen inlet, and a reagent dropping device, and heated to 70 ° C. in a water bath under a nitrogen stream. After dissolving 0.0004 parts of ferrous sulfate, 0.0012 parts of disodium ethylenediaminetetraacetate, and 0.8 parts of sodium formaldehyde sulfoxylate in 5 parts of distilled water and adding to the contents, 18 parts of acrylonitrile and 42 parts of styrene were added.
, A mixture of 0.3 parts of cumene hydroxyperoxide was added dropwise over 90 minutes, and then heating and stirring was continued for 1 hour. No solid matter was separated, and a uniform particle dispersion was obtained. The solid content of the particle dispersion is 33.2%, and the weight average particle size is 220.
nm.

The particle dispersion was poured into an aqueous calcium chloride solution, the solid was separated, filtered and dried to obtain a polytetrafluoroethylene-containing mixed powder (C-3). When observation with a transmission electron microscope was performed in the same manner as in Reference Example 1, 10
No polytetrafluoroethylene aggregates larger than μm were observed.

Examples 1 to 3 and Comparative Examples 1 to 3 The thermoplastic resins and flame retardants shown in Table 1 and C-1 to C-3 obtained in Reference Examples 1 to 3 were mixed with a twin screw extruder (WERNER & PFLEI).
Barrel temperature of 240 using DESKER ZSK30)
The mixture was melt-kneaded at ℃. The obtained pellets were formed into UL94-V test pieces at a cylinder temperature of 240 ° C. using an injection molding machine (IS-100 manufactured by Toshiba Machine Co., Ltd.). Various tests were performed using the obtained test pieces.

[0059]

[Table 1] The following is clear from the examples and the comparative examples.

(1) As in Examples 1 to 3, the thermoplastic resin composition obtained by the present invention is excellent in flame retardancy and molded appearance.

(2) As in Comparative Examples 1 to 3, when the molecular weight of the polycarbonate is low, the resulting thermoplastic resin composition is inferior in flame retardancy and surface appearance.

[0062]

According to the present invention, it is possible to obtain a thermoplastic resin composition having excellent flame retardancy and surface appearance.

The present invention provides an inexpensive resin material having excellent flame retardancy that can be used in the field of housing materials for home electric appliances, OA equipment, and the like, and its industrial utility value is enormous. .

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 69/00

Claims (2)

(57) [Claims] 1. A weight polycarbonate average molecular weight of 30,000 to 2,000,000 (A-1), flame retardant (B) and, Po
It is composed of lithitetrafluoroethylene particles and an organic polymer.
A thermoplastic resin composition comprising a polytetrafluoroethylene-containing mixed powder (C). 2. A polycarbonate (A-1) having a weight average molecular weight of 30,000 to 2,000,000, an aromatic vinyl polymer (A-2), a flame retardant (B) and polytetrafluorocarbon.
A thermoplastic resin composition comprising a polytetrafluoroethylene-containing mixed powder (C) comprising ethylene particles and an organic polymer .