JPH0335329B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a polymer composition with excellent flame retardancy, and more particularly to a polymer composition in which dripping of sparks during combustion is significantly reduced. (Prior art and its problems) Conventionally, aromatic monovinyl resins have been used in large quantities in various fields such as home appliances, interior decoration, and miscellaneous goods industries due to their excellent properties. However, aromatic monovinyl resins have the disadvantage that they are easily flammable and continue to burn spontaneously once they begin to burn, which naturally limits their use. In particular, flame retardant treatment is necessary when used as home appliances or electrical/electronic parts, and many so-called flame retardants are used, including halogen compounds such as chlorine and bromine, and compounds containing phosphorus. There is a known method of blending them to make them flame retardant. However, in recent years, demands for fire safety have become more and more important, and the U.S. UL (Underwriters Laboratory) vertical combustion test regulations for home appliances, OA equipment, etc. have become stricter over the years, and weight reduction and As the wall thickness of products and parts has become thinner to improve economic efficiency,
During combustion, sparks drip, causing damage to other products and parts.Therefore, there is a strong desire to develop a technology that prevents the sparks from falling, so-called anti-drip technology. As drip prevention techniques, methods are known such as increasing the amount of flame retardant, adding inorganic substances that do not burn, and adding olefin polymers or elastomers. The method of increasing the amount of flame retardant reduces the dripping property by shortening the combustion time, but it is not a preferable method because it requires the use of a large amount of flame retardant, which is originally expensive. do not have. Japanese Patent Application Laid-Open No. 52-127958 describes a method of blending non-combustible inorganic substances.
A method using potassium titanate, mica, sericite, and asbestos is known in Japanese Patent Publication No. 1985-85838, and a method of adding nickel titanate and calcium is known in Japanese Patent Application Laid-open No. 1985-85838. Since it lacks affinity with monovinyl-based materials, it has the disadvantage of poor mechanical properties. JP-A-53-46343 discloses a method of adding polyolefin, and JP-A-53-149244 discloses a method of adding an elastomer and an olefin polymer. This is not satisfactory as the heat resistance may deteriorate. Further, JP-A-59-98158 discloses a method of adding polytetrafluoroethylene to prevent dripping, but this method is economically unfavorable because a large amount of expensive polytetrafluoroethylene is added. Furthermore, in the case of thin-walled molded products, prevention of dripping is insufficient. The present invention has improved the above-mentioned drawbacks, and as a result of intensive studies on aromatic monovinyl resins with low dripping properties, we have developed an aromatic monovinyl resin copolymerized with a specific organofunctional silane compound and a specific fibrillated structure. By using an extremely small amount of polytetrafluoroethylene resin, the amount of flame retardant used can be reduced, and dripping properties are extremely low.
The present invention was achieved by discovering that a flame-retardant thermoplastic resin with excellent mechanical properties can be obtained. (Means for solving the problems) That is, the present invention provides an organofunctional silane compound represented by the following general formula. [In the formula, R ₁ is hydrogen or a methyl group, R ₁ is hydrogen,
or a methyl group, _R2 is a _C1 to _C4 alkyl group, m is an integer of 1 to 3, p is an integer of 1 to 3, and q is 3-p. ] is composed of an aromatic monovinyl resin containing as a copolymerization component, a flame retardant, and a polytetrafluoroethylene resin, an organofunctional silane compound is contained in the composition in an amount of 0.005% to 0.1% by weight, and This is a polymer composition with excellent flame retardancy, characterized in that the tetrafluoroethylene resin substantially has a fibrillated structure and is contained in the composition in an amount of 0.01% to 2.0% by weight. The organofunctional silane compound represented by the above general formula used in the present invention has a vinyl group or methacryloxy group that can be copolymerized with an aromatic monovinyl compound, and an Si-(OR) group (R is a methoxy group,
ethoxy group, etc.), such as γ
-methacryloxypropyltrimethoxysilane,
Examples include γ-methacryloxypropyltriethoxysilane and γ-methacryloxypropylmethyldimethoxysilane. In addition to styrene, monomers used in aromatic monovinyl resins include α-substituted styrene such as α-methylstyrene, o-methylstyrene,
One or a mixture of two or more nuclear-substituted styrenes such as p-chlorostyrene and 2,4,6-tribromustyrene, and substances containing these as main components and copolymerizable with them, such as acrylonitrile, methacrylonitrile, and methyl methacrylate. , ethyl methacrylate, maleic anhydride, and a monomer mixture containing small amounts of N-phenylmaleimide. The method for producing an aromatic monovinyl resin copolymerized with an organofunctional silane compound is to add the aromatic monovinyl monomer to which the organofunctional silane compound has been added, by a generally well-known method, such as suspension. - Can be produced by bulk polymerization method or bulk polymerization method. Further, the aromatic monovinyl resin may be a rubber-modified aromatic monovinyl resin,
A solution obtained by dissolving a rubbery polymer in the above-mentioned aromatic monovinyl monomer or the like can be produced by a suspension-bulk polymerization method or a bulk polymerization method. As the rubbery polymer, a homopolymer of conjugated 1,3-diene having 4 to 6 carbon atoms, such as 1,3-butadiene,
1,3-butadiene and isoprene copolymer,
1,3-butadiene or 1,3-butadiene and isoprene and other copolymerizable compounds, such as styrene, methylstyrene, dimethylstyrene, acrylonitrile, methacrylonitrile, alkyl esters of acrylic acid and methacrylic acid. It is a copolymer with These may be used alone or as a mixture of two or more. Particularly preferred are polybutadiene rubber and butadiene-styrene copolymer rubber. Also,
A resin obtained by blending an aromatic monovinyl resin containing an organic functional silane compound as a copolymerization component and an aromatic monovinyl resin containing no silane compound may be used. The flame retardant used in the present invention may be a halogen-based or phosphorus-based flame retardant that can be used in aromatic monovinyl resins. For example, halogenated flame retardants include aromatic halogen compounds, halogenated epoxy resins, halogenated polycarbonate resins, halogenated aromatic vinyl polymers, halogenated cyanurate resins, halogenated polyphenyl ethers, halogenated polyphenyl thioethers, etc. are mentioned, preferably decabromodiphenyl oxide, tetrabromo bisphenol A,
Oligomer of tetrabromo bisphenol A, brominated bisphenol epoxy resin, brominated bisphenol phenoxy resin, brominated bisphenol polycarbonate resin, brominated polystyrene resin, brominated crosslinked polystyrene resin, brominated bisphenol cyanurate resin ,
These include brominated polyphenylene oxide, polydibromophenylene oxide, decabromodiphenyl oxide bisphenol condensate, and halogen-containing phosphoric acid ester. The polytetrafluoroethylene resin used in the present invention needs to be in powder form and have a structure that is substantially fibrillated by shearing force during extrusion kneading or molding. Whether or not it has a fibrillated structure can be easily observed, for example, by molding a tanzak piece for an Izod impact test and taking a scanning electron micrograph of the fractured surface at the end of the Izot impact test. . Examples of the polytetrafluoroethylene forming the fibrillated structure as described above include Teflon 7-J and Teflon 6-J manufactured by Mitsui Dupont Fluorochemical Co., Ltd. In the present invention, a flame retardant aid having the effect of further increasing the effect of the flame retardant can be used. Examples thereof include molybdenum compounds and antimony compounds, and particularly preferred are sodium antimonate and antimony trioxide. In the present invention, a reinforcing filler can be used for the purpose of improving mechanical properties and heat resistance. Examples include fibrous reinforcing agents such as glass fiber and carbon fiber, and granular or flaky fillers such as mica, talc, clay, calcium silicate, glass foil, and glass beads. Particularly preferred are glass fiber and mica. The content of the organofunctional silane compound represented by the general formula used in the present invention is as follows:
It is necessary to contain 0.005 to 0.1% by weight.
If the amount is less than this range, the effect of suppressing the dripping of sparks during combustion will be small and sufficient flame retardancy will not be obtained. On the other hand, if it exceeds 0.1% by weight, the melt fluidity during kneading of the aromatic monovinyl resin and flame retardant will be significantly reduced, making it impractical. In the present invention, the surprising drip-inhibiting effect is exhibited only when the above-mentioned organofunctional silane compound and the polytetrafluoroethylene resin having a fibrillated structure are both present in the composition. When using an organofunctional silane compound alone, when the content is increased, the fluidity decreases significantly, making melt-kneading impossible and impractical. Polytetrafluoroethylene resin alone requires a large amount of content, resulting in an expensive polymer composition. In the present invention, a remarkable drip suppressing effect is exhibited even with a very small amount of polytetrafluoroethylene. The content of polytetrafluoroethylene used in the present invention is 0.01% to 2.0% by weight in the composition.
It is necessary that it be contained. Preferably it is 0.05% to 1.0% by weight, most preferably 0.05% by weight. If it is less than 0.01% by weight, the effect of suppressing the dripping of sparks during combustion will be small and sufficient flame retardancy will not be obtained. Also, if it exceeds 2.0% by weight,
In addition to becoming an economically expensive resin, the compatibility decreases and extrusion kneading becomes difficult, and the physical properties deteriorate, making it impossible to obtain a satisfactory resin. The polymer composition with excellent flame retardancy of the present invention is produced by combining an aromatic monovinyl resin containing an organofunctional silane compound as a copolymerization component, a flame retardant, and a polytetrafluethylene resin using an extruder, a Banbury mixer, It can be manufactured by melt-kneading using a kneader or the like. As mentioned above, the present invention is to reduce the dripping of sparks during combustion. Regarding the determination method
The vertical combustion test method specified in UL94 was adopted.
That is, a specimen 1/16 inch thick, 1/2 inch wide, and 5 inches long was clamped vertically with its long axis so that the lower end was 3/8 inch above the tip of the Bunsen burner tube. Fix it and apply a test flame to the lower end in a windless condition. After igniting for 10 seconds, move the test flame away and measure the combustion time (first ignition). Immediately after extinguishing the test flame, immediately ignite the next one for 10 seconds and measure the combustion time in the same way (second ignition). The same test is performed on 5 test pieces, and if the maximum combustion time does not exceed 10 seconds and the average combustion time is 5 seconds or less, and there are no drippings, the flammability rank is designated as V-0, and the maximum combustion time is 30 seconds. If the combustion time does not exceed 25 seconds on average and there are no drippings, the flammability rank is referred to as V-1; similarly, if the maximum combustion time does not exceed 30 seconds but on average 25 seconds or less and there are drips, Its flammability rank is called V-2. On the other hand, length 5 inches, width 1/2 inch, thickness 1/16
An inch test piece is fixed with a clamp with its long axis perpendicular, and a test flame is applied to the lower end under windless conditions. The burner is ignited away from the specimen and adjusted to a total flame height of 5 inches and a blue inner flame height of 11/2 inches. Apply the test flame to one corner of the lower end of the test piece for 5 seconds, then
Repeat the action of releasing for a second until you hit it 5 times. If, after removing the test flame for the fifth time, there is no continued flameless or flameless combustion for more than 60 seconds and no dripping of any material, this combustion rank is designated as 5-V. V-0 and V-1 level materials do not drip during combustion, so they are used in electrical and electronic parts, which have been increasing in recent years.
For mechanical parts, thin-walled small connectors, etc., the materials used are overwhelmingly V-0 level.
It can be said that V-2 level materials are not used at all. Furthermore, the flame retardance of materials used in OA, information equipment, etc. is becoming more stringent, and UL-94 5-V level is becoming required. The composition of the present invention contains various additives, such as antioxidants such as epoxies, phenols, and phosphates, and ultraviolet rays such as benzophenone and benzotriazole, for the purpose of improving thermal stability, photostability, and moldability. Absorbents, paraffin waxes, fatty acid esters, fatty acid amides, lubricants such as metal soaps, etc. can be added. In addition, other polymers, glass fibers,
Inorganic fillers such as calcium carbonate and mica can also be added. (Effects) The polymer composition of the present invention with excellent flame retardancy requires only a small amount of flame retardant, and has a flame retardancy rank of V-0, V-1, which is required for electrical products, office equipment, etc.
It has a non-dripping property that clears the 5-V rank,
It can be applied to various industrial product uses. Its special feature is that it clears the 5V rank with a wall thickness of 1/16 inch. (Example) Hereinafter, the present invention will be explained in detail with reference to Examples. Example 1 Polybutadiene rubber was treated with styrene monomer, γ-
Polybutadiene content 10% by weight obtained by dissolving in methacryloxypropyltrimethoxysilane and polymerizing with stirring, γ-methacryloxypropyltrimethoxysilane 0.05% by weight, styrene monomer
100.0 parts by weight of a copolymer resin consisting of 89.95% by weight, 13.0 parts by weight of flame retardant decabrom biphenyl ether, and 4.0 parts by weight of antimony trioxide as a flame retardant aid.
0.2 parts by weight of polytetrafluoroethylene (manufactured by Mitsui Dupont Fluorochemicals, 7-J) and reinforcing filler SB block copolymer (manufactured by Asahi Kasei, trade name;
2.0 parts by weight of Toughprene were melt-mixed in a 40φ extruder to form pellets. The resulting pellets are injection molded into 5 inches long, 1/2 inch wide, and 1/1 wall thick.
A 6-inch molded article for combustion testing was obtained. This test piece was subjected to a flammability test using the UL94 method, and it was confirmed that no sparks were dripped during the test. The flammability rank was as shown in the table. Comparative Example 1 Polybutadiene content of Example 1 10% by weight, γ
-methacryloxypropyltrimethoxysilane
Polybutadiene content: 10% by weight instead of a copolymer consisting of 0.05% by weight and 89.95% by weight of styrene monomer
A test piece was prepared in the same manner as in Example 1, except that a copolymer (HI-PS) consisting of 90% by weight of styrene monomer was used, and a flammability test was conducted. Since no organofunctional silane compounds were present, dripping was observed during the combustion test. The flammability rank is as shown in the table. Example 2 Polybutadiene content: 10 obtained by dissolving polybutadiene in styrene monomer and γ-methacryloxypropyltriethoxysilane and polymerizing it with stirring.
100.0 parts by weight of a copolymer resin consisting of 0.01% by weight of γ-methacryloxypropyltriethoxysilane, 89.99% by weight of styrene monomer, 15.0 parts by weight of flame retardant tetrabromobisphenol A monomer, and flame retardant tetrabromobisphenol. 7.0 parts by weight of A oligomer, 0.5 parts by weight of polytetrafluoroethylene (7-J), 5.0 parts by weight of antimony trioxide as a flame retardant aid, and 5.0 parts by weight of reinforcing filler SB block copolymer (manufactured by Asahi Kasei Co., Ltd., Tuffrene),
A test piece was prepared in the same manner as in Example 1, and a flammability test was conducted. It was confirmed that there was no dripping of sparks during the test. The flammability rank was as shown in the table. Comparative Example 2 Polybutadiene content of Example 2 10% by weight, γ
-Methacryloxypropyltriethoxysilane
Polybutadiene content: 10% by weight instead of a copolymer consisting of 0.01% by weight and 89.99% by weight of styrene monomer
Melt kneading was carried out using a 40φ extruder to obtain a composition in the same manner as in Example 2, except that a copolymer consisting of 0.4% by weight of γ-methacryloxypropyltriethoxysilane and 89.6% by weight of styrene monomer was used. However, the fluidity was significantly reduced and melt-kneading was impossible. It turned out to be of little practical use. Example 3 5 parts by weight of a copolymer resin consisting of 0.8% by weight of γ-methacryloxypropyltrimethoxysilane and 99.2% by weight of styrene monomer, and 95.0 parts by weight of a rubber-modified styrene polymer (HI-PS) with a rubber content of 12.4% by weight.
parts by weight and flame retardant tetrabromobisphenol A
12.0 parts by weight of monomer, 5 parts by weight of tetrabromo bisphenol A oligomer as a flame retardant, 0.07 parts by weight of polytetrafluoroethylene (7-J), 5.0 parts by weight of antimony trioxide as a flame retardant aid, and reinforcing filler SB.
Block copolymer (manufactured by Asahi Kasei, Toughprene)
Using 5.0 parts by weight, a molded article for combustion test was obtained in the same manner as in Example 1, and a flammability test was conducted. It was confirmed that no sparks were dripped during the test. The flammability rank was as shown in the table. Comparative Example 3 0.8% by weight of γ-methacryloxypropyltrimethoxysilane of Example 3 and 99.2% of styrene monomer
A test piece was prepared and a flammability test was conducted in the same manner as in Example 3, except that a polymer containing 100% by weight of styrene monomer (GPPS) was used instead of the copolymer containing 100% by weight of styrene monomer. Dripping was observed during the combustion test.
The flammability rank was as shown in the table. Example 4 Copolymer resin 25 consisting of 0.3% by weight of γ-methacryloxypropyltrimethoxysilane, 25% by weight of acrylonitrile, and 74.7% by weight of styrene monomer
parts by weight, polybutadiene as styrene monomer,
75.0 parts by weight of a copolymer (ABS) containing 15.0% by weight of polybutadiene, 25.0% by weight of acrylonitrile, and 60% by weight of styrene monomer obtained by dissolving in acrylonitrile and polymerizing with stirring, and the flame retardant tetrabromobisphenol A 13.0 parts by weight of monomer and 0.1 part of polytetrafluoroethylene (7-J)
parts by weight, and the ultraviolet absorber 2-(2'-hydroxy-5'-methylphenol)-benzotriazole
0.5 part by weight was melt-mixed using a 40φ extruder to form pellets. After drying the obtained pellets, combustion test pieces having a length of 5 inches, a width of 1/2 inch, and a wall thickness of 1/16 inch were obtained by injection molding. This test piece was subjected to a flammability test using the UL94 method, and it was confirmed that no sparks were dripped during the test. The flammability rank was as shown in the table. Comparative Example 4 In place of the copolymer resin consisting of 0.3% by weight of γ-methacryloxypropyltrimethoxysilane, 25% by weight of acrylonitrile, and 74.7% by weight of styrene monomer in Example 4, 0.01% by weight of γ-methacryloxypropyltrimethoxysilane was used. A flammability test was conducted in the same manner as in Example 4, except that a copolymer resin consisting of 25% by weight of acrylonitrile and 74.99% by weight of styrene monomer was used. As a result, the flammability ranks where dripping was observed were as shown in the table. It can be seen that a satisfactory composition cannot be obtained due to the small amount of organofunctional silane compound. Example 5 Polybutadiene was dissolved in γ-methacryloxypropyltriethoxysilane, acrylonitrile, and styrene monomer and polymerized with stirring. Polybutadiene content: 15.0% by weight, γ-methacryloxypropyltriethoxysilane 0.05% by weight, acrylonitrile 25.0% by weight, styrene monomer
100.0 parts by weight of a copolymer consisting of 59.95% by weight and 8.0 parts by weight of the flame retardant tetrabromobisphenol A monomer.
parts by weight, 15.0 parts by weight of the flame retardant tribromo bisphenol A oligomer, 0.2 parts by weight of polytetrafluoroethylene (7-J), 6.0 parts by weight of the flame retardant auxiliary antimony trioxide, and the flame retardant chlorinated polyethylene (Osaka Manufactured by Soda, product name: Daisolatsuku G235)
5.0 parts by weight were melt-mixed using a 40φ extruder to form pellets. After drying, the resulting pellets are injection molded to a length of 5 inches, a width of 1/2 inch, and a wall thickness of 1/16 inch.
Inch combustion specimens were obtained. This test piece is UL94
A flammability test was conducted using the method described above, and it was confirmed that no sparks were dripped during the test. The flammability rank was as shown in the table. Comparative Example 5 Polybutadiene content of Example 5 15.0% by weight,
γ-methacryloxypropyltriethoxysilane
0.05 wt%, acrylonitrile 25.0 wt%, and styrene monomer 59.95 wt%, polybutadiene content 15.0 wt%, γ
-Methacryloxypropyltriethoxysilane
A test piece was prepared in the same manner as in Example 5, except that a copolymer resin consisting of 0.005% by weight, 25.0% by weight of acrylonitrile, and 59.995% by weight of styrene monomer was used, and a flammability test was conducted. As a result, γ−
The content of methacryloxypropyltriethoxysilane was low, and the flammability rank was as shown in the table. Example 6 γ-methacryloxypropyltrimethoxysilane 0.1% by weight, methyl methacrylate 25.0% by weight,
100.0 parts by weight of a copolymer (MS) consisting of 74.9% by weight of styrene monomer, 13.0 parts by weight of flame retardant decabrom biphenyl ether, 0.2 parts by weight of polytetrafluoroethylene (7-J), and trioxide flame retardant aid. 4.0 parts by weight of antimony and 2.0 parts by weight of reinforcing filler SB block copolymer (manufactured by Asahi Kasei, Tuffrene) were melt-mixed in a 40φ extruder and pelletized.
After drying the obtained pellets, flammability test pieces with a length of 5 inches, width of 1/2 inch, and wall thickness of 1/16 inch were manufactured by injection molding, and a combustion test was conducted.No sparks were dripped during the test. I confirmed that there is no. The flammability rank was as shown in the table. Comparative Example 7 Example 2 except that polytetrafluoroethylene (TLP-10F-1, manufactured by Mitsui DuPont Fluorochemicals) was used instead of polytetrafluoroethylene (7-J, manufactured by Mitsui DuPont Fluorochemicals) in Example 2. A test piece was manufactured in the same manner as above, and a flammability test was conducted. Scanning electron microscopy of the fractured surface of the Izotsu specimen showed that 7-J was fibrillated (so-called string-like), but TLP-10F-
Sample No. 1 was not fibrillated at all and was dispersed in granular form. The flammability rank was as shown in the table.

【table】

【table】

Claims (1)

[Claims] 1. An organofunctional silane compound represented by the following general formula: [In the formula, R ₁ is hydrogen or a methyl group, R ₂ is C ₁ to C ₄
an alkyl group, m is an integer of 1 to 3, p is an integer of 1 to 3, and q is 3-p. ] is composed of an aromatic monovinyl resin containing as a copolymerization component, a flame retardant, and a polytetrafluoroethylene resin, an organofunctional silane compound is contained in the composition in an amount of 0.005% to 0.1% by weight, and A polymer composition having excellent flame retardancy, characterized in that a tetrafluoroethylene resin substantially has a fibrillated structure and is contained in the composition in an amount of 0.01% to 2.0% by weight. 2 The content of polytetrafluoroethylene resin is
The polymer composition with excellent flame retardancy according to claim 1, wherein the content is 0.05% to 0.5% by weight.