JP2010138214A - Resin composition for hot plate fusion, and lamp housing molded product of lighting fixture for carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for hot plate fusion, obtained by improving threading properties of the resin and surface appearance of a molded product at the hot plate fusion. <P>SOLUTION: The resin composition for the hot plate fusion is obtained by compounding 0.1-20 pts.wt. of a thermally expandable microcapsules (B) having a thermal expansion-starting temperature of ≥140°C with 100 pts.wt. of a thermoplastic resin (a single rubber-reinforced styrene-based resin, or a mixture of the rubber-reinforced styrene-based resin with other thermoplastic resins) (A). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hot plate fusion resin composition used for so-called hot plate fusion in which two or more kinds of resin materials are melted using a heated hot plate and then bonded by pressing the melted portion. It is.

2. Description of the Related Art Conventionally, in the bonding of resin molded products, fusion with a hot plate followed by pressure bonding (so-called hot plate fusion) has been increasingly adopted from the viewpoint of environmental problems because no solvent is used. However, in such a hot plate fusion method, after the thermoplastic resin is melted from the hot plate, the resin is stretched into a thread shape when the hot plate is pulled away (hereinafter referred to as string drawing property), which is a molded product. Adhering to the surface may cause a defect that causes a poor appearance.
Therefore, in order to improve these, for example, Patent Document 1 (Japanese Patent Laid-Open No. 11-199729), Patent Document 2 (Japanese Patent Laid-Open No. 2001-2881), Patent Document 3 (Japanese Patent Laid-Open No. 2001-207000), Patent Document 4 (Japanese Patent Laid-Open No. 2001-253990) proposes to use a resin composition containing an α-methylstyrene copolymer.
On the other hand, studies are underway to lower the hot plate fusing temperature for the purpose of shortening the environment and molding cycle or reducing the appearance defect of the weld surface. Since there is a problem that the pullability is lowered, an immediate improvement is demanded at present.
JP-A-11-199729 JP 2001-2881 A JP 2001-207000 A JP 2001-253990 A

  An object of the present invention is to solve the stringing property of the resin in the hot plate fusion at such a low temperature. The present inventors have found that stringiness is greatly improved by blending a small amount of capsules, and the present invention has been achieved.

  That is, the present invention is a yarn obtained by blending 0.1 to 20 parts by weight of thermally expandable microcapsules (B) having a thermal expansion start temperature of 140 ° C. or higher with respect to 100 parts by weight of the thermoplastic resin (A). It is an object of the present invention to provide a hot plate fusing resin composition with improved pullability.

  INDUSTRIAL APPLICATION This invention has an effect that the resin composition for hot plate bonding excellent in the stringing property and the external appearance of a molded article is obtained.

The present invention will be described in detail below.
Examples of the thermoplastic resin (A) used in the present invention include rubber-reinforced styrene resin, polyethylene terephthalate, polybutylene terephthalate, polyarylate and other saturated polyester resins, polycarbonate resin, polyphenylene oxide resin, methacrylic resin, polysulfone resin, poly Examples include ether sulfone resins, polyether ether ketone resins, polyether imide resins, polyphenylene sulfide resins, and the like, each of which is selected singly or in combination of two or more.

  Among these, it is preferable to use rubber-reinforced styrene-based resin, saturated polyester resin, polycarbonate resin, polyphenylene oxide resin, methacrylic resin or a mixture of two or more of these because of its moldability. It is preferable that it is a single material or a mixture of a rubber-reinforced styrene resin and another thermoplastic resin.

  In addition, when 2 or more types of thermoplastic resins used for this invention are mixed, the ratio does not have a restriction | limiting in particular, Although what was according to the objective can be used, especially rubber reinforced styrene-type resin 5-100 It is preferably a mixture comprising 95% by weight and 95% by weight of other thermoplastic resins.

The rubber-reinforced styrene resin used in the present invention is a graft formed by polymerizing a styrene monomer alone or a styrene monomer and another copolymerizable monomer in the presence of a rubbery polymer. A copolymer or a mixture of the graft copolymer and a copolymer obtained by polymerizing the monomer.
The rubbery polymer that can constitute the rubber-reinforced styrene resin is not particularly limited, but diene such as polybutadiene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl acrylate-butadiene, and the like. Rubber, butyl acrylate rubber, butadiene-butyl acrylate rubber, 2-ethylhexyl acrylate-butyl acrylate rubber, 2-ethylhexyl methacrylate-butyl acrylate rubber, stearyl acrylate-butyl acrylate rubber, polyorganosiloxane-butyl acrylate composite rubber Acrylic rubber such as ethylene-propylene rubber, polyolefin-based rubber polymer such as ethylene-propylene-diene rubber, and silicon-based rubber polymer such as polyorganosiloxane rubber. It may be used alone or in combination.

Examples of the styrene monomer that can constitute the rubber-reinforced styrene resin include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, and the like, and one or more of them can be used. In particular, styrene and α-methylstyrene are preferable.
Other copolymerizable monomers that can be used with the styrene monomer include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and (meth) methyl methacrylate and methyl acrylate. Examples include acrylic acid ester monomers, maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide, and unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid. Can be used alone or in combination of two or more.

The thermally expandable microcapsule (B) used as an essential component in the present invention has a structure in which hydrocarbons are encapsulated inside an outer shell made of a thermoplastic resin having a film thickness of 1 to 30 μm. is there.
Specific examples of such thermally expandable microcapsules (B) are described in detail in JP-A-5-285376, JP-A-2000-24488, JP-A-2002-320843, and the like.
The thermal expansion start temperature of the thermally expandable microcapsule (B) is 140 ° C. or higher, preferably 160 ° C. or higher. If the thermal expansion start temperature of the heat-expandable microcapsule (B) is less than 140 ° C., it is not preferable because the stringiness is poor. The thermal expansion start temperature described here refers to the temperature at which the volume increase of the microcapsule is started when measurement is performed at a heating rate of 10 ° C./min using a thermomechanical analyzer. Show.
Furthermore, although there is no restriction | limiting in particular in the average particle diameter of a thermally expansible microcapsule (B), Preferably it is 1-100 micrometers. As used herein, the average particle size refers to a particle size that uses a laser diffraction particle size distribution measuring instrument and is 50% of the cumulative volume particle size distribution.
Examples of such thermally expandable microcapsules (B) can be obtained from Matsumoto Yushi Seiyaku Co., Ltd. (trade name: Matsumoto Microsphere) and Sekisui Chemical Co., Ltd. (trade name: ADVANCEL). .

  The mixing ratio of the thermoplastic resin (A) and the thermally expandable microcapsule (B) is 0.1 to 20 parts by weight of the thermally expandable microcapsule (B) with respect to 100 parts by weight of the thermoplastic resin (A). Preferably it is 0.3-15 weight part. If the amount is less than 0.1 parts by weight, a sufficient effect of improving the stringiness cannot be obtained. If the amount exceeds 20 parts by weight, an appearance defect tends to occur in vapor deposition or painting due to gas during molding, which is not preferable.

  The mixing method of the thermoplastic resin (A) and the thermally expandable microcapsule (B) is not particularly limited. After mixing in a powder and / or pellet state, a roll, a Banbury mixer, a single screw or a twin screw that is usually used. A method of forming pellets using an extruder or the like and then forming the pellet, or a method of directly forming the thermoplastic resin (A) and the thermally expandable microcapsule (B) in the molding can be employed.

  In addition, conventionally known stabilizers, antioxidants, lubricants, pigments, dyes, fillers and the like may be added to the hot plate fusion resin composition in the present invention depending on the purpose.

  The hot plate fusion resin composition of the present invention can be suitably used for, for example, a vehicle lamp (so-called lamp housing molded product) such as a headlamp, a winker, and a stop lamp, but is not limited thereto. is not.

  Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited by this. Moreover, both parts and% are shown on a weight basis.

-Thermoplastic resin (A)-
Rubber-reinforced styrene resin (ABS-1): obtained by graft polymerization of 15 parts by weight of acrylonitrile and 35 parts by weight of styrene to 50 parts by weight of styrene-butadiene copolymer latex (solid content) by a known emulsion polymerization method. An ABS resin obtained by mixing 40 parts by weight of a graft polymer with 60 parts by weight of a copolymer composed of 30 parts by weight of acrylonitrile and 70 parts by weight of styrene.

  Rubber reinforced styrene resin (ABS-2): obtained by graft polymerization of 15 parts by weight of acrylonitrile and 35 parts by weight of styrene to 50 parts by weight of styrene-butadiene copolymer latex (solid content) by a known emulsion polymerization method. An ABS resin obtained by mixing 40 parts by weight of a graft polymer with 60 parts by weight of a copolymer comprising 30 parts by weight of acrylonitrile and 70 parts by weight of α-methylstyrene.

  Rubber Reinforced Styrenic Resin (AES): Graft polymer 40 obtained by graft polymerization of 15 parts by weight of acrylonitrile and 35 parts by weight of styrene to 50 parts by weight of ethylene-propylene-ethylidene norbornene copolymer by a known solution polymerization method. An AES resin obtained by mixing 60 parts by weight of a copolymer composed of 30 parts by weight of acrylonitrile, 10 parts by weight of N-phenylmaleimide and 60 parts by weight of styrene.

  Rubber Reinforced Styrene Resin (AAS): Graft polymer obtained by graft polymerization of 15 parts by weight of acrylonitrile and 35 parts by weight of styrene to 50 parts by weight of acrylic rubber latex (solid content) by a known emulsion polymerization method AAS resin obtained by mixing 60 parts by weight of a copolymer composed of 30 parts by weight of acrylonitrile and 70 parts by weight of styrene.

  Polycarbonate resin (PC): Caliber 200-30 (manufactured by Sumitomo Dow)

  Polycarbonate / rubber reinforced styrene resin mixture (PC / ABS): Mixture of 50 parts by weight of the above polycarbonate resin and 50 parts by weight of the above rubber reinforced styrene resin (ABS-1).

-Thermally expandable microcapsule (B)-
B-1: Matsumoto Microsphere F-190D (manufactured by Matsumoto Yushi Co., Ltd., thermal expansion start temperature 160 ° C.)
B-2: Matsumoto Microsphere F-230D (manufactured by Matsumoto Yushi Co., Ltd., thermal expansion start temperature 180 ° C.)
Bi: Matsumoto Microsphere F-170D (manufactured by Matsumoto Yushi Co., Ltd., thermal expansion start temperature 130 ° C.)

[Examples 1-8, Comparative Examples 1-5]
The thermoplastic resin or a mixture thereof and the thermally expandable microcapsule were pelletized by melt kneading at a cylinder temperature of 210 ° C. using a twin screw extruder at the ratio shown in Table 1. The obtained pellets were injection molded using an injection molding machine under the conditions of a cylinder temperature of 230 ° C. and a mold temperature of 50 ° C. to prepare each test piece. The following evaluation was performed about each obtained test piece.
The evaluation results are shown in Table 1.

In the examples, various physical properties were evaluated by the following methods.
Stringing property : An ASTM No. 1 dumbbell obtained by injection molding was pressed against an aluminum flat plate heated to 260 ° C. for 30 seconds at a pressure of 10 kgf / cm ² , and then the dumbbell was pulled up at a speed of 500 mm / min. The weight of the yarn that occasionally occurred on the fused surface was measured. It was also determined whether stringing occurred.
○: No stringing, △: Slight stringing, x: Stringing

  As described above, the hot plate fusion resin composition of the present invention is remarkably excellent in stringiness compared to conventional resins, and is used for hot plate fusion, particularly as a vehicular lamp (so-called lamp housing molded product). It can be used suitably.

Claims (5)

Hot plate fusion resin characterized by containing 0.1 to 20 parts by weight of thermally expandable microcapsules (B) having a thermal expansion start temperature of 140 ° C. or higher with respect to 100 parts by weight of thermoplastic resin (A). Composition. The resin composition for hot plate bonding according to claim 1, wherein the thermoplastic resin (A) is a rubber-reinforced styrene resin alone or a mixture of a rubber-reinforced styrene resin and another thermoplastic resin. The thermal expansion fusion resin composition according to claim 1 or 2, wherein the thermal expansion start temperature of the thermally expandable microcapsule (B) is 160 ° C or higher. The average particle size of the thermally expandable microcapsule (B) is 1 to 100 µm, The resin composition for hot plate fusion according to any one of claims 1 to 3. A lamp housing molded article for a vehicular lamp formed by molding the resin composition for hot plate welding according to any one of claims 1 to 4.