JP2002088253A - Non-halogen flame-retardant polymer molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-halogen flame-retardant polymer molded body having high flame retardancy, impact resistance and quality stability from a polymer composition comprising a polymer and a non-halogen flame-retardant. SOLUTION: The non-halogen flame-retardant polymer molded body is obtained by molding a polymer composition, comprising at least one polymer selected among polystyrenic, polyphenylene ether-based, polyolefinic, polyvinyl chloride-based, polyamide-based, polyester-based, polyphenylene sulfide-based, polyepoxy-based and polymethacrylate-based polymers and a non-halogen flame- retardant, with its melt viscosity lowered by dissolving carbon dioxide therein. The non-halogen flame-retardant polymer molded body is obtained particularly by injecting a molten polymer composition having its melt viscosity lowered by dissolving carbon dioxide into a mold cavity in a state pressurized by carbon dioxide in advance to a pressure higher than the pressure at which foaming is not brought about at a flow front of the molten polymey.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant polymer molded article. More specifically, by a specific processing method, obtained from a polymer composition comprising a polymer and a non-halogen flame retardant,
The present invention relates to a non-halogen flame-retardant polymer molded article having high flame retardancy, excellent impact resistance and quality stability.

[0002]

2. Description of the Related Art Polymers are superior to glass and metal in terms of moldability and impact resistance. Therefore, polymers are widely used in automobile parts, home electric appliances parts, OA equipment parts and the like. Although used in the field, their flammability limits their use. As a method of making a polymer flame-retardant, it is known to add a halogen-based, phosphorus-based, or inorganic-based flame retardant to the polymer, thereby achieving some degree of flame retardancy. However, in recent years, the demand for fire safety has been particularly noticed, and with the development of more advanced flame retardant technology, there is a strong demand for technology development that does not cause environmental problems or decrease in mechanical properties. Against this background, flame-retardant polymer moldings using non-halogen flame retardants have been developed, but in order to suppress thermal decomposition during processing of polymers or non-halogen flame retardants, low-temperature molding is possible. Processing technology is required.

[0003] Also, US Pat. No. 4,990,595 discloses a resin containing no gas after melting two or more resins such as polycarbonate in the presence of a supercritical gas and mixing them sufficiently until the viscosity is reduced by at least 10%. A method for producing a highly dispersed resin mixture by cooling to a viscosity equal to or higher than that and releasing the pressure is disclosed. In addition, WO98
/ 52734 pamphlet discloses an injection molding method in which carbon dioxide is blown during injection molding of a thermoplastic resin and can be melt-molded at a low temperature. However, both of the above publications do not disclose the molding of a polymer composition containing a non-halogen flame retardant, but do not even suggest that excellent flame retardancy is exhibited.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not have the above-mentioned problems, that is, a flame-retardant polymer molded article having excellent flame retardancy and excellent quality stability. The purpose is to provide.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on excellent flame-retardant polymer moldings, and as a result, surprisingly, by processing a polymer by a specific processing method, it is possible to obtain a stable quality. The inventors have found that the properties and flame retardancy can be dramatically improved, and completed the present invention. That is, the present invention is a polystyrene-based, polyphenylene ether-based, polyolefin-based, polyvinyl chloride-based, polyamide-based, polyester-based, polyphenylene sulfide-based, polyepoxy-based, one or more polymers selected from polymethacrylate polymer, By dissolving carbon dioxide in a polymer composition comprising a non-halogen flame retardant to reduce the melt viscosity and molding, a non-halogen flame-retardant polymer molded article characterized by being obtained, in particular, carbon dioxide The molten polymer composition in which the melt viscosity is reduced by dissolving carbon is previously pressurized with carbon dioxide to a pressure higher than a pressure at which foaming does not occur at the flow front of the molten polymer in the mold cavity, and the mold cavity is To provide a non-halogen flame-retardant polymer molded article obtained by injecting It is.

Hereinafter, the present invention will be described in detail. The molded article of the present invention is a flame-retardant polymer molded article obtained by subjecting a polymer composition comprising (A) a polymer and (B) a non-halogen flame retardant to specific processing. In order to improve the flame retardancy or strength of the molded product, or the gloss, appearance, and physical properties of the molded product, it is important to suppress thermal decomposition of the polymer or non-halogen flame retardant during processing. Requires processing technology capable of low-temperature molding. Here, by dissolving carbon dioxide in the polymer composition comprising (A) and (B),
It is important to reduce the melt viscosity for molding. In particular, it is preferable to lower the shear melt viscosity by 10% or more by dissolving carbon dioxide with respect to the shear melt viscosity when carbon dioxide is not dissolved in the polymer composition. By dissolving carbon dioxide in the molten polymer, carbon dioxide acts as a plasticizer only during molding, and after molding, the molded article does not deform and carbon dioxide is released into the atmosphere, without changing the polymer performance They have found that the viscosity of the molten polymer can be reduced and molding can be facilitated, and the present invention has been completed.

In the present invention, (A) is one selected from the group consisting of polystyrene, polyphenylene ether, polyolefin, polyvinyl chloride, polyamide, polyester, polyphenylene sulfide, polyepoxy, and polymethacrylate polymers. The above polymer may be thermoplastic or thermosetting, or may be a resin or rubber-based polymer. Among them, a thermoplastic resin or a rubber-based polymer is particularly preferable. Here, particularly preferred (A) is a polymer such as polystyrene, polyphenylene ether, polyamide, polyester, polyepoxy, and polyolefin. The preferred polystyrene-based polymer (A) is a rubber-modified styrene-based polymer and / or a non-rubber-modified styrene-based polymer, particularly a rubber-modified styrene-based polymer alone or a rubber-modified styrene-based polymer. It is preferably composed of a modified styrene-based polymer, and is not particularly limited as long as it can be uniformly dispersed with (B). The rubber-modified styrene-based polymer refers to a polymer in which a rubber-like polymer is dispersed in a matrix in a matrix composed of a vinyl aromatic-based polymer, and an aromatic vinyl-based polymer is present in the presence of a rubber-like polymer. The monomer and, if necessary, a vinyl monomer copolymerizable therewith are added to obtain a monomer mixture by a known polymerization method such as bulk polymerization, emulsion polymerization and suspension polymerization. Examples of such polymers include high impact polystyrene (HIPS), A
Examples include a BS polymer (acrylonitrile-butadiene-styrene copolymer), an AAS polymer (acrylonitrile-acryl rubber-styrene copolymer), and an AES polymer (acrylonitrile-ethylene propylene rubber-styrene copolymer).

Here, the rubber-like polymer preferably has a glass transition temperature (Tg) of -30 ° C. or lower.
If it exceeds 30 ° C., the impact resistance tends to decrease. Examples of such rubbery polymers include diene rubbers such as polybutadiene, poly (styrene-butadiene) and poly (acrylonitrile-butadiene), and saturated rubbers obtained by hydrogenating the diene rubbers, isoprene rubber, chloroprene rubber, and polyacrylic rubber. Acrylic rubber such as butyl acid and ethylene-propylene copolymer rubber, ethylene-propylene-diene monomer terpolymer rubber (EPDM), ethylene-octene copolymer rubber, etc.
Particularly, a diene rubber is preferable. The aromatic vinyl monomer as an essential component in the graft-polymerizable monomer mixture to be polymerized in the presence of the rubbery polymer, for example, styrene,
α-methylstyrene, paramethylstyrene and the like, and styrene is most preferable, but the above-mentioned other aromatic vinyl monomer may be copolymerized mainly with styrene. If necessary, one or more monomer components copolymerizable with the aromatic vinyl monomer can be introduced as components of the rubber-modified styrene-based polymer as (A). When it is necessary to increase oil resistance, unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile can be used. When it is necessary to lower the melt viscosity at the time of blending, an acrylate having an alkyl group having 1 to 8 carbon atoms can be used. Furthermore, when it is necessary to further increase the heat resistance of the polymer composition, α-methylstyrene, acrylic acid, methacrylic acid, maleic anhydride,
A monomer such as N-substituted maleimide may be copolymerized. The content of the vinyl monomer copolymerizable with the vinyl aromatic monomer in the monomer mixture is from 0 to 40% by weight.

The rubbery polymer in the rubber-modified styrenic polymer is preferably from 5 to 80% by weight, particularly preferably from 10 to 50% by weight, and the graft-polymerizable monomer mixture is preferably from 95 to 20% by weight. , More preferably 90
５０50% by weight. Within this range, the balance between impact resistance and rigidity of the desired polymer composition is improved. Further, the particle diameter of the rubber-like polymer of the rubber-modified styrenic polymer is preferably from 0.1 to 5.0 μm, particularly preferably from 0.1 to 5.0 μm.
2-3.0 μm is preferred. Within the above range, impact resistance is particularly improved. The reduced viscosity ηsp / c of the polymer part, which is a measure of the molecular weight of the rubber-modified styrenic polymer (0.5
g / dl, 30 ° C. measurement: toluene solution when the matrix resin is polystyrene, methyl ethyl ketone when the matrix resin is an unsaturated nitrile-aromatic vinyl copolymer) is in the range of 0.30 to 0.80 dl / g. It is more preferably, and more preferably in the range of 0.40 to 0.60 dl / g. Means for satisfying the above requirements regarding the reduced viscosity ηsp / c of the rubber-modified styrenic resin include adjustment of the polymerization initiator amount, polymerization temperature, and chain transfer agent amount. When heat resistance and oil resistance are particularly required among the polystyrene-based polymers, a syndiotactic styrene-based polymer that is a crystalline styrene-based polymer is preferable.

The polyphenylene ether polymer as the preferred (A) is a polyether having an aromatic ring in the main chain, and specific examples thereof include poly (2,6-dimethyl-1,4-phenylene ether). ), A copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, etc. are preferred, and poly (2,6-dimethyl-1,4-phenylene ether) is particularly preferred. Reduced viscosity ηsp of the polyphenylene ether used in the present invention
/ C (0.5 g / dl, chloroform solution, measured at 30 ° C.) is preferably in the range of 0.20 to 0.70 dl / g, and more preferably in the range of 0.30 to 0.60 dl / g. More preferred. As a means for satisfying the above requirements regarding the reduced viscosity ηsp / c of the polyphenylene ether, adjustment of the amount of a catalyst in the production of the polyphenylene ether and the like can be mentioned. The preferred (A)
Is an aliphatic or aromatic polyamide-based polymer, for example, a condensate of dicarboxylic acid and diamide such as 6,6-nylon or a caprolactam ring-opening polymer such as 6-nylon. The polyester polymer as the preferred (A) is an aliphatic or aromatic polyester polymer, and is preferably a condensate of a dicarboxylic acid and a dialcohol or diphenol, such as polybutylene terephthalate and polyethylene terephthalate.

The polyepoxy polymer as the preferred (A) is an aliphatic or aromatic polyester polymer, or a thermoplastic or thermosetting polymer, for example, a thermoplastic polymer of epichlorohydrin and bisphenol A. Condensates are preferred. The polyolefin-based polymer as the preferred (A) is preferably an ethylene-based resin or a propylene-based resin, and includes high-density polyethylene, low-density polyethylene, homo-isotactic polypropylene, propylene and ethylene, butene-1, pentene-
And isotactic copolymer resins (including block and random) with other α-olefins such as 1, hexene-1 and the like. Among them, particularly preferred polyolefin-based polymers include rubbery polymers, and are partially or completely crosslinked thermoplastic polymers composed of a crosslinkable rubbery polymer such as an ethylene-α-olefin copolymer and a polyolefin. Yes, for example, by dynamically crosslinking in the presence of a crosslinking agent and a crosslinking aid.

(B) in the present invention is a phosphorus, nitrogen, sulfur or inorganic flame retardant. The phosphorus-based flame retardant comprises an organic phosphorus-based, red phosphorus-based, and inorganic phosphorus-based flame retardant. Examples of the organic phosphorus flame retardant of the phosphorus flame retardant (B) in the present invention include phosphine, phosphine oxide, biphosphine, phosphonium salt, phosphinate, phosphate ester, phosphite ester and the like. More specifically,
Triphenyl phosphate, methyl neopentyl phosphate, pentaerythritol diethyl diphosphite, methyl neopentyl phosphate, phenyl neopentyl phosphate, pentaerythritol diphenyl diphosphate, dicyclopentyl high positive phosphate, dineopentyl hypophosphite Phenylpyrocatechol phosphite, ethyl pyrocatechol phosphate, and dipyrocatechol hypopositive phosphate. Here, as the organic phosphorus compound, an aromatic phosphate ester monomer and an aromatic phosphate ester condensate are particularly preferred. In the above (B), red phosphorus, one of the phosphorus-based flame retardants, is a metal water previously selected from aluminum hydroxide, magnesium hydroxide, zinc hydroxide and titanium hydroxide in addition to general red phosphorus. Coated with an oxide coating, coated with a coating of a metal hydroxide selected from aluminum hydroxide, magnesium hydroxide, zinc hydroxide and titanium hydroxide and a thermosetting resin, It is a double-coated thermosetting resin film on a metal hydroxide film selected from aluminum, magnesium hydroxide, zinc hydroxide and titanium hydroxide.

In the above (B), one inorganic phosphorus-based flame retardant of the phosphorus-based flame retardant is ammonium polyphosphate or a composite flame retardant of the same with a nitrogen compound, or a phosphazene-based compound, particularly having an aromatic group. And a compound having a structure in which a phosphorus atom and a nitrogen atom are connected by a double bond, such as cyclic phosphazene or linear phosphazene. Among the phosphazenes, from the viewpoint of compatibility with the polymer (A), the phosphazene contains an aromatic group such as a phenyl group, a cresyl group, a xylyl group, and a bisphenyl group as a substituent. Specifically, phenoxypropoxyphosphazene, diphenoxyphosphazene, phenoxyaminophosphazene, phenoxyfluoroalkylphosphazene, and the like.These phosphazene compounds substitute chlorophosphazene with alcohols or phenols. It is manufactured by doing. The nitrogen-based flame retardant as (B) is typically a compound containing a triazine skeleton, and is a component for further improving the flame retardancy as a flame retardant aid of a phosphorus-based flame retardant. Specific examples thereof include melamine, melam, melem, melon (a product of deammonification of three to three molecules of melem at 600 ° C. or higher), melamine cyanurate, melamine phosphate, succinoguanamine, adipguanamine. And melamine resin, melamine resin and BT resin, and melamine cyanurate is particularly preferred from the viewpoint of low volatility.

Examples of the sulfur-based flame retardant (B) include metal salts of organic sulfonates such as potassium trichlorobenzenesulfonate, potassium perfluorobutanesulfonate, potassium diphenylsulfon-3-sulfonate, and metal aromatic sulfonimides. Metal salts of sulfonic acid, metal sulfate, metal phosphate, metal borate, or ammonium salts of the above acids, phosphoric acid salts, or aromatic rings of polymers containing aromatic groups such as styrene polymers and polyphenylene ethers. It is a sulfur-based flame retardant such as an alkali metal salt of polystyrene sulfonic acid to which a sodium salt or the like is bound. Such a sulfur-based flame retardant promotes a decarboxylation reaction during combustion, particularly when the polymer is a polycarbonate, to improve flame retardancy. Further, in the case of the alkali metal polystyrene sulfonate, the metal sulfonate itself becomes a cross-linking point during combustion and greatly contributes to the formation of a carbonized film. The inorganic flame retardant (B) includes an organic silicon compound, silica, aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, basic magnesium carbonate, and hydroxide. Hydrates of inorganic metal compounds such as zirconium and tin oxide hydrates, aluminum oxide, iron oxide, titanium oxide, manganese oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide,
Metal oxides such as chromium oxide, tin oxide, antimony oxide, nickel oxide, copper oxide, and tungsten oxide, aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, tin, and antimony Metal powder, and zinc borate, etc.
Examples include zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate and the like. These may be used alone or in combination of two or more. Among them, those selected from the group consisting of magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, and hydrotalcite have particularly good flame retardant effects and are economically advantageous.

Among the inorganic flame retardants (B), organosilicon compounds are preferable, and polyorganosiloxanes represented by silicone or organic silicate are preferred. Polyorganosiloxanes are classified into oils, resins, and rubbers according to their properties. Oil is a linear polydiorganosiloxane, M units resins represented by R ₃ SiO _1/2 monofunctional, D units represented by R ₂ SiO difunctional, trifunctional RSiO _3/2 , T unit represented by tetrafunctional SiO ₂ , R (RO) SiO _2.0 (X unit) containing alkoxy or aryloxy, (R
O) ₂ SiO _3.0 (Y unit) is a linear polyorganosiloxane containing a branched structure or a silicone resin having a three-dimensional network structure, which can be formed by combining structural units of Y. And vulcanized polydiorganosiloxane. Other polyorganosiloxanes include modified polyorganosiloxanes modified with epoxy, amino, mercapto, methacrylic groups, etc., polycarbonate (PC) -silicone copolymers, acrylic rubber-silicone composites and the like. In the present invention, a linear polydiorganosiloxane, which is one of preferred organosilicon-based flame retardants, contains an aromatic group, and preferably has a kinematic viscosity at 25 ° C. specified in JIS-K2410 of 10 centistokes or more. , More preferably 100 centistokes or more, even more preferably 1000 centistokes or more.

In the present invention, another preferred organosilicon-based flame retardant is a polyorganosiloxane having a branched structure (branched silicone) or a silicone resin having a three-dimensional network structure (crosslinked silicone resin). Such silicones consist of RSiO _1.5 (T units) and / or RSiO _1.0 (D units) and, if desired,
R ₃ SiO _0.5 (M unit), SiO _2.0 (Q unit), R
(RO) SiO _2.0 (X unit), (RO) ₂ SiO _3.0
(Y unit). Here, R has 1 to 1 carbon atoms.
20 hydrocarbons, preferably a methyl group, an ethyl group, a butyl group, a phenyl group, and a benzyl group, particularly preferably those containing a methyl group and a phenyl group. When the phenyl group contains 10% by weight or more, water resistance, heat stability,
The compatibility with the aromatic resin is improved. In the present invention, (B) is used in an amount of 0.01 to 1 based on 100 parts by weight of (A).
The amount is preferably 00 parts by weight, more preferably 0.1 to 50 parts by weight, and most preferably 1 to 20 parts by weight. When a higher degree of flame retardancy is required in the present invention, a flame retardant auxiliary (C) selected from a fibrous flame retardant and a char forming agent can be blended as necessary.

The fibrous flame retardant (C) is a flame retardant used to prevent dripping of fire, and becomes fibrous when added or processed. Specific examples thereof include aramid fiber, polyacrylonitrile fiber, and fluororesin. The aramid fiber has an average diameter of 1 to 5
It is preferable that the average fiber length is 0.1 to 10 mm at 00 μm, and it is produced by dissolving isophthalamide or polyparaphenylene terephthalamide in a polar amide solvent or sulfuric acid and spinning the solution by a wet or dry method. Can be. The polyacrylonitrile fiber as the fibrous flame retardant preferably has an average diameter of 1 to 500 μm and an average fiber length of 0.1 to 10 mm, and dissolves the polymer in a solvent such as dimethylformamide, 400 ° C.
It is produced by a dry spinning method in which the polymer is dissolved in a solvent such as nitric acid, or a dry spinning method in which the polymer is dissolved in a solvent such as nitric acid. The fluororesin as the fibrous flame retardant is a resin containing a fluorine atom in the resin. Specific examples thereof include polymonofluoroethylene, polydifluoroethylene, polytrifluoroethylene, polytetrafluoroethylene, and a tetrafluoroethylene / hexafluoropropylene copolymer. If necessary, the fluorine-containing monomer may be used in combination with a copolymerizable monomer.

The char forming agent (C) is preferably a novolak resin or the like. Particularly, a phenol novolak resin obtained by condensing phenols and aldehydes in the presence of an acid catalyst such as sulfuric acid or hydrochloric acid is particularly preferable. preferable. In the present invention, the addition amount of (C) is preferably 0.001 to 100 parts by weight, more preferably 1 to 50 parts by weight, and most preferably 3 to 20 parts by weight based on 100 parts by weight of (A).
Parts by weight, very preferably 5 to 15 parts by weight. In the present invention, if necessary, aliphatic hydrocarbons, higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher aliphatic alcohols, metal soaps, organosiloxane waxes, polyolefin waxes, polycaprolactone, or one or more selected from Two or more types of release agents or processing aids (D) as flow improvers can be blended.
The amount of (D) is preferably 0.01 to 20 parts by weight, more preferably 0.5 to 1 part by weight, per 100 parts by weight of (A).
0 parts by weight, most preferably 1 to 5 parts by weight.

In the present invention, if light resistance is required, an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, an active species trapping agent, a light-shielding agent, a metal deactivator may be used, if necessary. Or one or more light resistance improvers (E) selected from quenching agents.
The amount of (E) is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of (A).
0 parts by weight, most preferably 1 to 5 parts by weight. The flame-retardant polymer molded article of the present invention is produced by lowering the shear melt viscosity by 10% or more by dissolving carbon dioxide with respect to the shear melt viscosity when carbon dioxide is not dissolved in the polymer composition. . As one of the production methods, specifically, a molten polymer composition in which carbon dioxide is dissolved to reduce the melt viscosity is previously heated to a pressure equal to or higher than a pressure at which foaming does not occur at the flow front of the molten polymer. In this method, carbon is pressurized and injected into the mold cavity. In the present invention, it is preferable that before the production of the molded article, the polymer composition is produced in advance, followed by introducing carbon dioxide to produce the molded article by the above-mentioned processing method. As a method for preparing the polymer composition in advance, for example, a method in which (A) and (B) are directly mixed and melt-kneaded by an extruder, or (A) is first melted, and then (B) is added, and There is a method of melt-kneading with an extruder, or a method of producing a master batch containing (B) and then kneading the master batch and (A).

In the present invention, the following two methods are preferred as a method for dissolving carbon dioxide in the polymer composition (A). One is a method in which a granular or powdery polymer is placed in a carbon dioxide atmosphere in advance and the carbon dioxide is absorbed and supplied to a molding machine. The absorption amount is determined by the pressure, the atmospheric temperature, and the time for absorbing the carbon dioxide. . In this method, a part of carbon dioxide in the polymer is volatilized as the polymer is heated at the time of plasticization, so that the amount of carbon dioxide in the molten polymer is smaller than the amount previously absorbed.
For this reason, it is desirable that the supply path of the polymer such as the hopper of the molding machine is also in a carbon dioxide atmosphere. Another method is to plasticize the polymer in the cylinder of the molding machine or dissolve carbon dioxide in the plasticized polymer. Inject carbon dioxide into the plasticized polymer from the tip or cylinder. When carbon dioxide is injected from an intermediate portion of a screw or a cylinder, it is preferable to increase the depth of the screw groove near the injection portion to lower the polymer pressure. In order to uniformly dissolve and disperse carbon dioxide in the polymer after injecting carbon dioxide, it is preferable to attach a mixing mechanism such as a dalmage or a kneading pin to the screw or to provide a static mixer in the polymer flow path. As an injection molding machine, either an in-line screw system or a screw prepra system can be used.However, the screw prepra system is easy to change the screw design of the extruder part for plasticizing the polymer and the injection position of carbon dioxide. Particularly preferred. The carbon dioxide in the polymer composition (A) gradually diffuses into the atmosphere if the molded article is left in the atmosphere after the polymer composition has solidified. No bubbles are generated in the molded article due to the radiation, and the performance of the molded article after the radiation is essentially the same as that of the thermoplastic resin.

In the present invention, a mold cavity is previously formed.
Injection molding is performed by applying a gas pressure above the pressure at which foaming does not occur at the flow front of the molten polymer during filling of the polymer. The gas pressure to be filled in the cavity should be the minimum pressure that does not cause a foaming pattern on the surface of the molded product.The amount of gas used in one process should be minimized, and the structure of the mold cavity seal and gas supply device should be reduced. For simplicity, the gas pressure is preferably low. If the gas pressure exceeds 15 MPa, problems tend to occur such that the force for opening the mold cannot be ignored or the sealing of the mold cavity becomes difficult. As the gas to be injected into the mold cavity, air or nitrogen, or a single or mixture of various gases which are inert to the polymer (A) can be used, but carbon dioxide and carbon dioxide having high solubility in a thermoplastic resin can be used. Hydrogen and those obtained by partially replacing hydrogen with fluorine are preferred, and carbon dioxide is particularly preferred because it has a high effect of improving the transferability of the mold surface state to a molded article. (A) When an amorphous resin is used for the polymer and the cavity is pressurized with carbon dioxide,
As described in Japanese Patent Application No. 236763 and Japanese Patent Application No. 10-46903, increasing the gas pressure in the cavity provides better transferability, so when high transferability is required, It is desirable to increase the gas pressure as much as possible according to the clamping force of the molding machine and the sealing performance of the mold. The carbon dioxide content of the gas in the mold cavity is preferably higher, more preferably 80% by volume or more. Gases at various temperatures can be used. Heated gas as well as gas at ambient temperature can be used favorably. In the case of a heated gas, a mixed gas of a liquid vapor and a carbon dioxide that easily dissolves the carbon dioxide can be used favorably.

In the present invention, 0.2 to 3% by weight of carbon dioxide
A molding method of sequentially or simultaneously injecting the dissolved (A) polymer composition and another thermoplastic resin into the mold cavity can also be used favorably. The injection molding method of filling the mold cavity by injecting the (A) polymer composition in which carbon dioxide is dissolved in 0.2 to 3% by weight and then injecting another thermoplastic resin containing no carbon dioxide is particularly preferable. Can be used. Other thermoplastic resins (A) Polymer composition and the same type of thermoplastic resin with different carbon dioxide content, different molecular weight, different type of thermoplastic resin, further different carbon dioxide content And this combination can be appropriately selected. By blending carbon dioxide into the polymer composition (A), the melt viscosity is reduced, and a composite injection molded article comprising a uniform surface layer of another thermoplastic resin and the inner core of the polymer composition (A) is obtained. . By using a thermoplastic resin excellent in heat resistance, chemical resistance, physical properties, etc. for other thermoplastic resins, the surface layer can be coated with other thermoplastic resins and the performance of molded products can be improved .

[0023]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention. In addition, the measurement in an Example and a comparative example was performed using the following method or a measuring device. (1) The amount of carbon dioxide in the molten resin It is difficult to directly measure the amount of carbon dioxide in the molten resin injected into the mold cavity. Therefore, the weight of the molded product immediately after the injection molding using the resin containing carbon dioxide. And the difference between the weights of the molded articles, which were left in a hot air dryer about 30 ° C. lower than the glass transition temperature for 24 hours or more, and the amount of carbon dioxide contained in the molded articles was diffused and became constant. Was the amount of carbon dioxide in the molten resin injected into the mold cavity. (2) Shear Melt Viscosity For resins containing no carbon dioxide, use a capillary rheometer manufactured by ROSAND Co.
The shear melt viscosity (Pa · s) was determined under the conditions of ° C. and a shear rate of 1000 sec ⁻¹ , and used as a measure of fluidity. Test conditions: Long die length 16 mm Long die diameter 1 mm Short die length 0.25 mm Short die diameter 1 mm Die entry angle 180 deg For resin containing carbon dioxide, the hole of the injection molding machine nozzle is 1 mm in diameter and 5 mm in length, and the shear rate is Was performed for about 1000 sec ^−1, and the resin pressure in the cylinder required for the free purge was compared with a resin containing no carbon dioxide to determine a shear melt viscosity. (3) Flame retardancy VB (Vertical Bur) conforming to UL-94
The self-extinguishing property was evaluated by the ning method. (1
/ 8 inch thickness test piece) (4) Izod impact strength Measured by a method based on ASTM-D256. (23
° C, 1/4 inch thick test piece with V notch)

(5) Extrusion stability (quality stability) The resin composition was continuously melt-extruded for 10 hours using a melt extruder, and the Izod impact strength of the composition obtained every hour was measured. Maximum change rate against the average intensity (%)
The continuous productivity (quality stability) was evaluated from the Izod change rate (%) in Tables 1 to 5. The following components were used for each component used in Examples and Comparative Examples. (A) Non-halogen flame retardant (a) Metal salt of organic sulfonate UCB Nippon Co., Ltd., potassium diphenylsulfon-3-sulfonate (referred to as S1) (b) 1,3-phenylene bis (diphenyl phosphate) Daihachi Chemical Industry Co., Ltd., aromatic condensed phosphate ester derived from resorcinol [trade name: CR733S (referred to as P1)] (c) Bisphenol A bis (diphenyl phosphate) Daihachi Chemical Industry Co., Ltd., [trade name: CR741 (P2 and (D) 1,3-phenylene bis (dixylyl phosphate) manufactured by Daihachi Chemical Industry Co., Ltd., [trade name PX200 (referred to as P3)] (e) Red phosphorus manufactured by Rin Kagaku Kogyo Co., Ltd., [products] Name Nova Excel (P4
(F) Ammonium polyphosphate, manufactured by Chisso Corporation, [trade name (named P5)] (g) Phenoxyphosphazene Phenoxyphosphazene (P) synthesized by a known method
(H) Magnesium hydroxide, manufactured by Kyowa Chemical Industry Co., Ltd., [trade name: Kusuma (referred to as MOH)] (i) Melamine cyanurate manufactured by Nissan Chemical Industries, Ltd., [trade name: MC610 (referred to as M1) (J) Polyorganosiloxane A known technique, for example, Chapter 17 of "Silicone Handbook" [edited by Nikkan Kogyo Shimbun, Kunio Ito (1990)]
According to the silicone production method, linear (D-type) methylphenyl silicone (referred to as S1), branched / cross-linked (D / T
(Type) methylphenylsilicone (referred to as S2) and a branched / crosslinked type (T type) methylphenylsilicone (referred to as S3) were obtained.

(B) Flame retardant aid Polytetrafluoroethylene (manufactured by Daikin Industries, Ltd., PTFE) (C) Polymer Abbreviated in parentheses as follows: (a) Nylon 6, 6 (PA66) manufactured by Toray Industries, Inc. (b) Nylon 6 (PA6) manufactured by Toray Industries, Inc. (c) Polyethylene terephthalate (PET) Teijin Limited (d) Polybutylene terephthalate (PBT) Polybutylene terephthalate synthesized by a known method (e) Thermoplastic epoxy resin: Epichlorohydrin-bisphenol A condensate (EP) manufactured by Dainippon Ink and Chemicals, Inc. (f) Rubber-modified polystyrene (HIPS) Asahi Chemical Industry (Polybutadiene / polystyrene (10/90: weight ratio)) Stylon (HIPS
(G) ABS resin (ABS) (Acrylonitrile / Polybutadiene / Styrene (24/20/56: weight ratio) trade name Styrac ABS (referred to as ABS)) manufactured by Asahi Kasei Kogyo Co., Ltd. (h) Styrene Ethylene butylene-styrene copolymer (SEBS) manufactured by Asahi Kasei Kogyo Co., Ltd. (trade name: Tuftec (referred to as SEBS)) (i) Styrene butadiene copolymer (SB) manufactured by Asahi Kasei Kogyo Co., Ltd. (Referred to as SB)) (j) Polyphenylene ether (PPE) manufactured by Asahi Kasei Kogyo Co., Ltd. (trade name: Zylon (referred to as PPE)) (k) Polypropylene (PP) Nippon Polychem Co., Ltd. (referred to as PP) (l) Ethylene-octene copolymer (EO) Dupont Dow elastomer [trade name Engage (E
O)) (m) Polyvinyl chloride (PVC) Shin-Etsu Chemical Co., Ltd. (n) Polyphenylene sulfide (PPS) Polyphenylene sulfide synthesized by a known method (o) Polymethyl methacrylate (PMMA) Asahi Kasei (P) EO-PP crosslinked product (TPV) where TPV is EO / PP = 50/50 (weight ratio)
Is a thermoplastic polypropylene dynamically crosslinked with a twin screw extruder using an organic peroxide and divinylbenzene.
(Referred to as TPV)

(Molding machine) SG is manufactured by Sumitomo Heavy Industries, Ltd.
125M-HP was used, and the screw was a two-stage vent type with L / P24 and a diameter of 32 mm. The vent was pressurized with carbon dioxide to dissolve carbon dioxide in the molten resin. As the nozzle, a needle type shut-off type nozzle was used. (Mold) As the mold, a molded product having a square shape and a rectangular shape were used. The product part of the square plate mold is 100 for each length and width.
mm and a thickness of 2 mm. Regarding the structure of a square plate mold, the cavity surface is mirror-finished,
mm direct gate, sprue length is 58m
m, the diameter of the nozzle touch portion was 3.5 mm. Depth of 0.0 for gas supply and release around the mold cavity
A 5 mm vent slit and vent, and a hole from the vent to the outside of the mold are provided and connected to the counter gas supply device.
A ring was provided to make the cavity airtight. (Counter gas supply device) A cylinder filled with liquefied carbon dioxide was kept at 35 ° C and used as a gas supply source. The gas passes through a heater from a cylinder, is adjusted to a predetermined pressure by a pressure reducing valve, and is then stored in a gas reservoir having an internal capacity of 1000 cm ³ kept at about 40 ° C. Gas supply to the mold cavity is performed by opening the supply solenoid valve downstream of the gas reservoir and simultaneously closing the release solenoid valve, and the gas reservoir and the cavity are connected during resin filling. At the same time as the resin filling is completed, the supply electromagnetic valve is closed and the release electromagnetic valve is opened to release the gas out of the mold.

Example 1, Comparative Example 1 The compositions (parts by weight) shown in Table 1 were mixed with a Henschel mixer, and subsequently a twin-screw extruder (40 mm) having an injection port in the center of the barrel was used.
φ, L / D = 47) and 1 at 240 ° C.
Continuous melt extrusion was performed for 0 hours. As the screw, a double screw having a kneading portion before and after the injection port was used. A molded article was prepared from the composition thus obtained by injection molding at a cylinder set temperature of 250 ° C. and a mold temperature of 80 ° C. under the following conditions, and was evaluated. That is, the resin as the above composition was dried in a hot air drier at 120 ° C. for 5 hours, and the carbon dioxide pressure in the vent portion was 5 MPa, and the screw rotation speed was 150.
Plasticized at rpm. Then, counter pressure molding using carbon dioxide was performed using a square plate mold having a mold surface temperature of 80 ° C., and the resin pressure in the cylinder of the molding machine required for filling the resin was measured. When the resin filling time was 0.5 seconds and the counter pressure was 1 MPa, the required filling pressure was 211 MPa. After filling the resin, the pressure was maintained at a cylinder internal pressure of 190 MPa for 5 seconds, and after cooling for 20 seconds, the molded product was taken out. The molded product was a transparent molded product having no foaming pattern on the surface. The amount of carbon dioxide in the plasticized molten resin determined from the weight loss of the molded article after the injection molding was 0.5% by weight. (Example 1) On the other hand, without supplying carbon dioxide to the vent portion, the resin pressure in the cylinder of the molding machine required for filling the resin was measured in the same manner as in Example 1. Without counter pressure, required filling pressure is 2
It was 35 MPa. (Comparative Example 1) The molten resin of Example 1 and Comparative Example 1 was subjected to free purge using a molding machine nozzle for measuring the shear melt viscosity, and the amount of reduction in the shear melt viscosity due to carbon dioxide was determined. there were. Table 1 shows the results of the above details.

(Examples 2 and 3, Comparative Example 2) Except that the composition was changed to the composition shown in Table 2 and the rate of decrease in melt viscosity was changed to 10% and 30% by controlling the amount of carbon dioxide introduced. The same experiment as in Example 1, Comparative Example 1 was repeated. The results are shown in Table 2. (Examples 4 to 39) The composition was changed to the composition shown in Tables 3 and 5, and the rate of decrease in melt viscosity was controlled to 1 by controlling the amount of carbon dioxide introduced.
The same experiment as in Example 1 and Comparative Example 1 was repeated except that the value was changed to 5%. The results are shown in Tables 3 to 5.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

According to the present invention, according to a specific processing method,
From a polymer composition comprising a polymer and a non-halogen flame retardant,
A non-halogen flame-retardant polymer molded article having high flame retardancy, impact resistance and quality stability is provided. The molded article of the present invention includes a VTR, a distribution board, a television, an audio player,
Household appliances such as condensers, household outlets, radio cassettes, video cassettes, video disc players, air conditioners, humidifiers, electric warm air machines, etc.
System or parts, CD-ROM main frame (mechanical chassis), printer, fax, PPC, CRT,
OA equipment housing such as word processor copier, electronic cash register, office computer system, floppy disk drive, keyboard, type, ECR, calculator, toner cartridge, telephone, etc. -Parts or components, connectors, coil bobbins, switches, relays, relay sockets, LEDs, variable capacitors, AC adapters, FBT high-voltage bobbins, FBT cases, IFT coil bobbins, jacks, volume shafts, motor parts, etc. Electronic and electrical materials, instrument panels, radiators
Automotive materials such as grills, clusters, speaker grills, lovers, console boxes, defroster garnishes, ornaments, fuse boxes, relay casings, connector shift tapes, etc. It plays a large role in these industries.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/00 C08K 5/00 C08L 83/04 C08L 83/04 // B29K 23:00 B29K 23:00 25 : 00 25:00 27:06 27:06 33:04 33:04 63:00 63:00 67:00 67:00 71:00 71:00 77:00 77:00 81:00 81:00 F term ( Reference) 4F071 AA12 AA12X AA13 AA13X AA15 AA15X AA20 AA20X AA21X AA22 AA22X AA33 AA33X AA41 AA42 AA45 AA46 AA51 AA54 AA55 AA67 AA77 AB06 AB07 AB08 AB09 AB10 A18 AB19 A23 AB26 AB05 AB15 4J002 BB031 BB121 BB141 BB151 BC031 BC122 BD041 BG051 BN061 BN121 BN141 BN151 BP021 BP031 CC182 CD051 CF061 CF071 CH071 CH072 CL011 CL031 CN011 CP022 CP032 CP052 CP092 DA102CP162 DE1060 DA1020 DE116 DE126 DE136 DE146 DE236 DE246 DE266 DE286 DH056 DJ016 DK006 EU186 EV256 EW016 EW046 EW066 EW136 EW146 EW156 EW176 FB076 FB266 FD132 FD136 FD160

Claims (2)

[Claims] 1. Polystyrene, polyphenylene ether, polyolefin, polyvinyl chloride, polyamide, polyester, polyphenylene sulfide,
By dissolving carbon dioxide in a polymer composition comprising one or more polymers selected from polyepoxy and polymethacrylate polymers and a non-halogen flame retardant, the melt viscosity is reduced to form And a non-halogen flame-retardant polymer molded article obtained. 2. The molten polymer composition, in which the melt viscosity is reduced by dissolving carbon dioxide, is previously pressurized with carbon dioxide at a pressure equal to or higher than the pressure at which foaming does not occur at the flow front of the molten polymer in the mold cavity. 2. The method according to claim 1, wherein the injection is performed by injection into a mold cavity.
The non-halogen flame-retardant polymer molding according to the above.