JPH0433817B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a conductive thermoplastic resin composition. The conductive thermoplastic resin composition obtained by the present invention can be used for surface heating elements, and for removing static electricity such as IC packaging magazines and photosensitive film packaging, but it can also be used for electromagnetic shielding of various electronic devices. Used for housings, power cables, and shielded wires. PRIOR TECHNOLOGY Many compositions of molding materials for plastic housings for electromagnetic shielding are already known, in which conductive fillers such as metal fibers are blended with thermoplastic resin.
-Introduced on page 85 etc. however,
At present, little progress has been made in the practical application of these compositions. One of the reasons for this is that most of these resins containing conductive fillers use housing resins such as ABS resin, polyphenyl ether, polypropylene, and polycarbonate as matrix polymers, but when metal fibers are mixed, the physical properties deteriorate significantly. In addition, moldability may be impaired, resulting in a molded product with poor surface properties including appearance. Plastic housings, which replace metals, are characterized by the ability to integrally mold complex shapes, which is difficult to do with metals, so deterioration in formability and physical properties is fatal. In addition, polyester resins such as polybutylene terephthalate have low hygroscopicity and excellent dimensional properties, so they are used as materials for mechanical parts.
Because it tends to warp and has poor impact resistance, its use in housings is limited. Also, nylon resin is
It has the drawbacks of high hygroscopicity and lack of dimensional stability. Problems to be Solved by the Invention The present invention provides a plastic housing that has excellent moldability such as fluidity, good surface properties, little warping and sink marks, and has sufficient mechanical strength including impact resistance and heat resistance. The present invention provides a conductive composite resin suitable for electromagnetic shielding. Means for Solving the Problems The present invention proposes that when a metal filler such as metal fiber is blended into a matrix polymer of a specific composition containing thermoplastic polyester, aromatic polycarbonate, and thermoplastic soft resin as essential components, impact resistance and fluidity can be improved. This is based on the discovery that a composite resin with excellent moldability, electrical conductivity, and electromagnetic shielding properties can be obtained, with no or little deterioration in various physical properties such as properties. That is, the present invention comprises 5 to 94 parts by weight of thermoplastic polyester (A), 5 to 94 parts by weight of aromatic polycarbonate (B),
At least one thermoplastic soft resin selected from the group of polymers consisting of two or more vinyl monomers and exhibiting rubber elasticity at room temperature, polyurethane, polyester elastomer, and polyamide elastomer.
(C) 1 to 40 parts by weight and metal filler (D) 2 to 400 parts by weight, and the amount (parts by weight) of each of (A), (B), (C), and (D) A conductive thermoplastic resin composition that satisfies the following formulas [] and []. A+B+C=100...[] D/20≦C≦D/20+25...[]. The present invention will be explained in detail below. The thermoplastic polyester (A) used in the present invention is a linear polymer having ester bonds in its molecular chain, and is usually a homo or/and copolymer obtained by a condensation reaction of a dicarboxylic acid component and a diol component. Examples of dicarboxylic acid components include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyl Examples include aromatic dicarboxylic acids such as ether dicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, and sebacic acid, and ester-forming derivatives thereof. Examples of diol components include ethylene glycol, 1,4-butanediol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol,
Diethylene glycol, triethylene glycol, 1,1-cyclohexanedimethanol, 1,
4-Cyclohexane dimethanol, xylylene glycol, 2,2-bis-(4-hydroxyphenyl)-propane, bis-(4-hydroxyphenyl)-sulfone, bis-(hydroxyethoxy)-
Benzene, ethylene oxide adduct of 2,2-bis-(4-hydroxyphenyl)-propane, 2,
Examples include propylene oxide adducts of 2-bis-(4-hydroxyphenyl)-propane and ester-forming derivatives thereof. Furthermore, lactone polyesters such as polycaprolactone, polypivalolactone, and poly-β-propiolactone, which are produced by ring-opening polymerization of lactone compounds, are also mentioned as examples of the thermoplastic polyester (A) used in the present invention. Particularly preferred thermoplastic polyesters include polyethylene terephthalate and polybutylene terephthalate. The aromatic polycarbonate (B) used in the present invention is a homo- or copolycarbonate or a mixture thereof, and is obtained by a polycondensation reaction of known bisphenols and phosgene or carbonic acid diester. Examples of bisphenols include the following compounds. Hydroquinone, resorcinol, dihydroxydiphenyl, bis-(hydroxyphenyl)-alkane, bis-(hydroxyphenyl)-cycloalkane, bis-(hydroxyphenyl)-sulfide, bis-(hydroxyphenyl)-ether, bis -(Hydroxyphenyl)-
Ketones, bis-(hydroxyphenyl)-sulfoxide, bis-(hydroxyphenyl)-sulfone and α,α-bis-(hydroxyphenyl)-diisopropylbenzene. Particularly preferred aromatic polycarbonates are poly-2,2-bis-(4-hydroxyphenyl)-propane-carbonate, poly-
2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane-carbonate is mentioned. Bis-(hydroxyphenyl)-alkane copoly(ester-carbonate) can also be used as the aromatic polycarbonate, and this is made by adding terephthalic acid, isophthalic acid, etc. to the above-mentioned bis-(hydroxyphenyl)-alkane polycarbonate. It is a copolymer of aromatic dicarboxylic acids. The thermoplastic soft resin (C) used in the present invention may be any thermoplastic resin that exhibits rubber elasticity at room temperature, and its glass transition temperature is preferably 0°C or lower, more preferably -20°C or lower. The soft resin (C) is selected, for example, from the group consisting of random, block, and glass copolymers made of two or more vinyl monomers, or polyurethane, polyester elastomer, and polyamide elastomer. The vinyl monomers used in the present invention are olefin monomers, such as ethylene, propylene, 1- and 2-
Butene, isobutene, 1- and 2-pentene, 1
- and 2-hexene, etc. Vinyl halide monomers, such as vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrachloroethylene, vinyl chloride, vinylidene chloride, vinyl bromide,
Vinylidene bromide, vinyl iodide, etc. Diene monomers such as butadiene, isoprene, piperylene, chlorprene, 1,5-hexadiene, norbornadiene, ethylidene norbornene, etc. Aromatic vinyl monomers such as styrene, α-methylstyrene, α-chlorostyrene, P-chlorostyrene, 2,4-dichlorostyrene, P-methylstyrene, 3,4-dimethylstyrene, O and P-divinyl Benzene, P-methyl-α-methylstyrene, P-chloro-α-methylstyrene, etc. Acrylic acid or methacrylic acid derivatives, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, n- and isc-propyl acrylate, n- and iso-butyl methacrylate, cyclohexyl methacrylate, Allyl acrylate, allyl methacrylate, sodium, potassium, zinc, magnesium metal salts of acrylic acid or methacrylic acid, etc.
Vinyl ester monomers, such as vinyl acetate, vinyl propionate, vinyl laurate, vinyl benzoate, etc. Vinyl ether monomers, such as methyl vinyl ether, ethyl vinyl ether, etc. Unsaturated dibasic acid derivatives such as maleic acid, maleic anhydride, methyl maleate, etc. can be mentioned, and homopolymers, random, block, and graft copolymers of vinyl monomers can be obtained by known radical polymerization or ionic polymerization. be able to. As a preferred example, ethylene-vinyl acetate copolymer,
Ethylene-propylene copolymer, ethylene-propylene-butadiene copolymer, ethylene-ethyl acrylate copolymer, styrene-butadiene block copolymer, selectively hydrogenated styrene-butadiene block copolymer, ethylene-propylene-styrene graft copolymer, ethylene-propylene-styrene-acrylonitrile graft copolymer, ethylene-propylene-butadiene-styrene graft copolymer, ethylene-propylene-butadiene-styrene-acrylonitrile graft copolymer, acrylonitrile-butadiene-styrene graft copolymer, butadiene-styrene-methyl methacrylate graft copolymer, butadiene-acrylonitrile copolymer, butadiene-styrene- Acrylonitrile-methyl methacrylate graft copolymer, butadiene-acrylonitrile-methacrylic acid copolymer, styrene-maleic anhydride copolymer, ethylene-maleic acid graft copolymer, styrene-ethyl acrylate-acrylic acid n
There are polymers made of two or more vinyl monomers, such as -butyl-allyl methacrylate graft copolymer, zinc salt of ethylene-methacrylic acid copolymer, and magnesium salt of ethylene-methacrylic acid copolymer. The polyurethane used in the present invention is a thermoplastic material obtained by reacting a polyester, polyether, or a mixture of two or more of low molecular weight polyols having two or more active hydrogen atoms in at least one molecule with a polyfunctional isocyanate. It is polyurethane. Suitable polyesters include, for example, polyesters obtained from organic acids such as phthalic acid, adipic acid, and maleic acid and glycols such as ethylene glycol, propylene glycol, butylene glycol, or, if necessary, small amounts of triols such as trimethylolpropane and glycerin. These are lactone polyesters such as polycaprolactone, polypivalolactone, and poly-β-propiolactone. Suitable polyethers are, for example, polyoxyethylene glycol, polyoxypropylene glycol, poly(oxypropylene) poly(oxyethylene) glycol, polyoxytetramethylene glycol. Low molecular weight polyols refer to glycols such as ethylene glycol, propylene glycol and butylene glycol, and triols such as trimethylolpropane and glycerin. Suitable examples of polyfunctional isocyanates are tolylene diisocyanate, tolylene diisocyanate dimer, diphenylmethane-4,4'-diisocyanate, hydrogenated diphenylmethane-4,4'-
Examples include diisocyanate and hexamethylene diisocyanate. The polyester elastomer used in the present invention is
It is a copolymer consisting of an aromatic polyester block and a polyether block or an aromatic polyester block and an aliphatic polyester block. Examples of the dicarboxylic acid forming the aromatic polyester block include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, adipic acid, and sebacic acid, with terephthalic acid and isophthalic acid being particularly preferred. Examples of the diol include tetramethylene glycol, ethylene glycol, propylene glycol, hexamethylene glycol, and cyclohexane glycol, with tetramethylene glycol being particularly preferred. Examples of the polyether include polyoxyethylene glycol, polyoxypropylene glycol, and polyoxytetramethylene glycol, with polyoxytetramethylene glycol being particularly preferred. Examples of aliphatic polyesters include polyadipate, polysebacate, polycaprolactone, etc.
Particularly preferred is polycaprolactone. The polyamide elastomer used in the present invention is a copolymer consisting of a polyamide block such as polycaprolactam or polylaurolactam and a polyester block or a polyether block such as polyoxyethylene, polyoxypropylene or polyoxytetramethylene. The proportions of the thermoplastic polyester (A), aromatic polyester (B), and thermoplastic soft resin (C) of the present invention are respectively (A) 5 to 94 parts by weight, preferably 15 to 80 parts by weight,
(B) 5-94 parts by weight, preferably 15-80 parts by weight, (C) 1-94 parts by weight
40 parts by weight, preferably 5 to 30 parts by weight, (A), (B), (C)
The total amount is 100 parts by weight. More preferred ranges are (A) 20 to 70 parts by weight, (B) 20 to 70 parts by weight,
(C) 10 to 25 parts by weight. If (A) is less than 5 parts by weight or (B) is more than 94 parts by weight, moldability such as fluidity and solvent crack resistance will deteriorate, and mechanical properties such as impact resistance will deteriorate. Also, if (A) exceeds 94 parts by weight or (B) exceeds 5 parts by weight, moldability will be poor, warping will occur easily, and impact resistance and weld line strength will be insufficient. . If (C) exceeds 40 parts by weight or D/20 + 25, the heat deformation temperature, tensile strength, flexural modulus, etc. will decrease, and if it is less than 1 part by weight or less than D/20, the surface of the molded product will become smooth. The strength, impact resistance, and weld line strength are insufficient. The metal filler (D) used in the present invention includes iron,
Examples include fillers in the form of fibers, flakes, or particles made of metals such as aluminum, copper, nickel, and various alloys thereof, and fillers in the form of fibers, flakes, or particles whose surfaces are coated with metals such as aluminum or nickel. . The fibrous metal filler is, for example, a metal fiber manufactured by a known drawing method, melt spinning method, cutting method, crack vibration cutting method, etc., or a metal whisker manufactured by crystallization from a gas phase or precipitation from a liquid phase. There are also metal-coated fibers produced by coating non-metallic fibers with metal. Particularly preferred examples are aluminum fibers, brass fibers, stainless steel fibers, aluminum coated glass fibers and nickel coated carbon fibers, usually with a fiber diameter of 1 to 150μ and a fiber length of 0.5 to 0.5μ.
Although short fibers of 15 mm are used, it is also possible to use metal filaments such as stainless steel long fibers. In this case, a method is carried out in which a bundle of metal filaments is impregnated with a fat component and the strands are cut to produce pellets. Examples of flaky metal fillers include flakes of metal such as aluminum and nickel, and flaky nonmetallic fillers whose surfaces are coated with metals such as aluminum and nickel. Particularly preferred is nickel-coated mica, which typically has a thickness of 1 to 200μ,
Use one with width x length 0.1 to 15 mm x 0.1 to 15 mm. Particulate metal fillers include, for example, powders of iron, aluminum, copper, nickel, and alloys thereof, and nonmetallic powders coated with aluminum or nickel. Usually, particles with a particle size of 0.5 to 500μ are used. It is important that the amount of the metal filler (D) is 2 to 400 parts by weight, preferably 5 to 300 parts by weight, particularly 8 parts by weight, based on 100 parts by weight of the thermoplastic resin mixture.
~200 parts by weight is preferred. If the amount of metal fiber (D) is less than 2 parts by weight, the effect of imparting conductivity will be insufficient, and if it exceeds 400 parts by weight, fluidity will decrease, making compounding, kneading, and molding extremely difficult. It becomes difficult. Further, the metal filler (D) is preferably surface-treated with a known silane-based, titanate-based, or aluminum-based coupling agent. Coupling treatment increases adhesion with the resin, further improves heat deformation temperature, tensile strength, etc., and further suppresses changes in conductivity due to environmental changes. The conductive thermoplastic resin composition of the present invention may optionally include a fibrous reinforcing agent or non-fibrous filler to improve rigidity, tensile strength, etc., a thermal oxidation inhibitor, an ultraviolet degradation stabilizer, a mold release agent, Lubricants, small amounts of branching and crosslinking agents (epoxy resins, polyfunctional compounds such as triaryl compounds), flame retardants such as red phosphorus, phosphorus compounds, halogen compounds, flame retardant aids such as antimony oxide and zinc oxide, and polyester crystals. Graphite, talc, and
Crystallization promoters such as organic acid metal salts can be added. The thermoplastic polyester (A), aromatic polycarbonate (B), thermoplastic welcoming resin (C), and metal liner (D) of the present invention can be blended by melt-kneading and pelletizing them all at once, or by melt-kneading them all at once and pelletizing them. At the time of molding, the metal filler (D) is melt-kneaded with one or more types of (A), (B), or (C) in advance to produce master pellets, and the remaining resin is blended at the time of molding. Any known method can be used, such as a method in which the resin is mixed with a resin component and molded, or a method in which a metal filament is impregnated with a resin component as described in the description of the fibrous metal filler, and then cut into pellets. Hereinafter, the present invention will be explained in more detail with reference to Examples. Examples Examples 1 to 11 and Comparative Examples 1 to 5 Polyethylene terephthalate (Kanebo Gosen EFG-6), copolyethylene terephthalate isophthalate (Kanebo Gosen IFG-8) as thermoplastic polyester, poly(bisphenol A) as aromatic polycarbonate carbonate)
(Teijin Kasei Panlite K-1300), thermoplastic soft resins such as ethylene-vinyl acetate copolymer (Mitsui Polychemical Evaflex-150), styrene-butadiene block copolymer (Denki Kagaku Kogyo Co., Ltd.)
Denka STR1602), ionomer (Mitsui Polychemical Himilan 1554), brass fiber with a fiber diameter of 30μ and fiber length of 1.5mm as a metal filler (Kobe Cast Iron Works
KC Metal Fiber 2600), glass fiber (Nitto Boseki fiber length 6 mm), antioxidant (Ciba Geigy Irganox 1010), and crystallization accelerator (talc) were used as additives to the composition shown in Table 1. The mixture was blended, melt-kneaded and extruded into strands using a 25 mm diameter extruder (screw rotation speed 100 rpm, discharge rate 90-120 g/min, cylinder temperature 250-265°C), and pellets were produced using a pelletizer. Next, the pellets were injection molded using a commonly used injection molding method for reinforced polyethylene terephthalate resin, and their physical properties were measured. The results are shown in Table-2.

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[Table] Examples 12 to 18 and Comparative Examples 6 to 8 Based on 60 parts by weight of polybutylene terephthalate (Polyplastics Juranex 2011) and 30 parts by weight of poly(bisphenol A carbonate) (Teijin Kasei Panlite K-1300) As a thermoplastic soft resin, acrylic rubber-acrylonitrile-styrene copolymer (Hitachi Chemical Vitax)
V6101AP), ethylene-propylene copolymer (Nippon Synthetic Rubber EPOIPX), styrene-butadiene block copolymer (Denka Kagaku Kogyo Denka
STR1602) and polyester elastomer (Toyobo Pelprene P-150M), aluminum fiber (fiber diameter 60 μ, fiber length 2
mm, ) (Kobe Foundry Works KC Metal Fiber A2017)
and stainless steel fiber (fiber diameter 8μ, fiber length 5mm)
(Nippon Seisen nylon sizing tip
Irganox 1010 (Ciba Geigy) was added as an additive (SUS316L) to the compositions shown in Table 3. However, in Example 17 and Comparative Example 8,
The polybutylene terephthalate was 45 parts by weight, and the thermoplastic soft resin was 25 parts by weight. Next, Example 1~
The pellets were made into pellets in the same manner as in No. 11, injection molded under normal injection molding conditions for reinforced polybutylene terephthalate resin, and the physical properties were measured. Table the results.
4. Examples 19 and 20 The pellets containing the stainless steel fibers produced in Example 17 were used as master pellets, and during molding, polybutylene terephthalate, poly(bisphenol A carbonate), and styrene were mixed to obtain the composition shown in Table 3. - Diluted with butadiene block copolymer, injection molded and measured physical properties. The results are shown in Table 4. However, in Example 20, a bisphenol A-based epoxy resin (manufactured by polymerizing bisphenol A diglycidyl ether and bisphenol A) was added at a ratio of 0.5 parts by weight to 100 parts by weight of the resin composition.

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[Table] Example 21 Polyethylene terephthalate (Kanebo Gosen
EFG-6) 35 parts by weight, styrene-butadiene block copolymer (Denka Kagaku Kogyo Denka
15 parts by weight of STR1602) was mixed with 30 parts by weight of the stainless steel fibers used in Examples 15 to 19, and the diameter was 25 mm.
Extruder (screw rotation speed 100 rpm, discharge amount 105
Pellets were produced using a cylinder temperature of 260°C. Next, poly(bisphenol A carbonate) was added to 80 parts by weight of the pellets.
(Teijin Kasei Panlite K-1300) 30 parts by weight and fully aromatic polyester (Unitika U Polymer U
-100) was blended during molding, injection molded (cylinder temperature 290°C, mold temperature 110°C), and the physical properties were measured. The results are shown in Table-5. Example 22 A mixture of bisphenol A, phosgene, and terephthaloyl chloride and isophthaloyl chloride was interfacially condensed to 80 parts by weight of the pellets blended with polyethylene terephthalate, styrene-butadiene block copolymer, and stainless fiber of Example 21. 50 parts by weight of the copolyester carbonate thus prepared was blended during molding, injection molded in the same manner as in Example 21, and measured for physical properties. The results are shown in Table-5. Examples 23 and 24 50 parts by weight of polybutylene terephthalate (Polyplastics Yuranex 2011), 30 parts by weight of poly(bisphenol A carbonate) (Teijin Kasei Panlite K-1300), styrene-butadiene block copolymer (Denka Kagaku Kogyo Co., Ltd.) STR1602)
20 parts by weight and brass fiber (fiber diameter 20μ, fiber length 1
mm) (Kobe Foundry Works KC Metal Fiber C-
2600) was blended, pelletized and injection molded in the same manner as in Examples 1 to 11. However, the example
In No. 24, brass fibers were used that had been surface-treated with a coupling agent, γ-glycidioxypropyltrimethoxysilane (Nippon Unicar A187) (0.5% by weight based on the brass fibers) before blending. The results of the measured physical properties are shown in Table-6. Examples 25-27 Polyethylene terephthalate (Kanebo Gosen
EFG-6) 50 parts by weight, poly(bisphenol A)
carbonate) (Teijin Kasei Panlite K-1300)
As shown in Table 7 for 30 parts by weight and 0.1 parts by weight of Irganox 1010, as a thermoplastic soft resin,
Ethylene-vinyl acetate copolymer (Mitsui Polychemical Evaflex 150), styrene-butadiene block copolymer (Denka Kagaku Kogyo Denka)
STR1602), aluminum coated glass fiber as metal filler (fiber diameter 25μ, fiber length 5mm) (MBA),
Nickel coated mica (Nickel coated mica manufactured by Mitsubishi Metals) was blended, kneaded and injection molded in the same manner as in Examples 1 to 11. Table 8 shows the results of physical property measurements.
Shown below.

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[Table] Example 28 An example will be described in which stainless steel long fibers (fiber diameter 8μ) (Nippon Seisen Naslon SUS316L) were used as the metal filler. Polybutylene terephthalate (polyplastics, diyuranetx)
2011) 60 parts by weight, polybisphenol A carbonate (Teijin Kasei Panlite K-1300) 30 parts by weight, styrene-butadiene block copolymer (Denka Kagaku Kogyo Denka STR1602) 10 parts by weight, and Irganox 1010 (Ciba Geigy) 0.1 part by weight The mixture was blended, melted and kneaded using an extruder with a diameter of 25 mm, and extruded to form bundles of stainless steel long fibers impregnated with a resin component to form strands, which were then cut using a pelletizer to produce pellets. This pellet is resin
It contained 100 parts by weight of stainless fiber per 100 parts by weight. This was injection molded under the same conditions as Examples 12 to 18, and the physical properties were measured. Table 9 shows the results.
Shown below. Effects of the Invention The metal filler (D) constituting the conductive thermoplastic resin composition of the present invention imparts excellent conductivity to the thermoplastic resin, which is originally electrically insulating, in a small amount, and improves bending strength and
Improves flexural modulus and greatly increases heat deformation temperature. A polymer blend consisting of thermoplastic polyester (A), aromatic polycarbonate (B), and thermoplastic soft resin (C) has excellent impact resistance, heat resistance, solvent resistance, and moldability in the presence of metal filler (D). , provides weld strength and surface smoothness. The conductive thermoplastic resin composition of the present invention has excellent conductivity with a volume resistivity of the order of 10 ^-2 Ωcm, high impact strength, heat distortion temperature, and weld strength, as well as good moldability and It also has a smooth molded surface.

Claims (1)

[Scope of Claims] 1 A polymer consisting of 5 to 94 parts by weight of thermoplastic polyester (A), 5 to 94 parts by weight of aromatic polycarbonate (B), and two or more types of vinyl monomers and exhibiting rubber elasticity at room temperature. 1 to 40 parts by weight of at least one thermoplastic soft resin (C) selected from the group of polyurethane, polyester elastomer, and polyamide elastomer, and 2 to 400 parts by weight of a metal filler (D), and ( A conductive thermoplastic resin composition in which the blending amounts (parts by weight) of A), (B), (C), and (D) satisfy the following formulas [ ] and [ ]. A+B+C=100...[] D/20≦C≦D/20+25...[]2 The vinyl monomer is an olefin monomer, a halogenated vinyl monomer, a dienated monomer, an aromatic vinyl monomer acrylic acid or methacrylic acid derivatives,
The composition according to claim 1, which is a vinyl ester monomer, a vinyl ether monomer, and an unsaturated dibasic acid derivative.