JP2535622Y2 - Lamp case - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp case which is used as a lamp case for automobiles or a closed type lamp case for lighting, and has a glass surface which does not fog.

[0002]

2. Description of the Related Art Conventionally, as a lamp case, a sheet metal or a molded article of an unsaturated polyester resin composition has been used. However, in recent years, the shape of the lamp case has become complicated with the demand for increased functionality, and deep drawing workability has been required for the case material. Molded products are used. FIG. 1 shows a plan view of an automobile lamp unit including an automobile lamp case 1, a glass 2 used in combination with the lamp case 1, and a lamp 3 sealed by the glass 2 and the lamp case 1. FIG. 2 shows a front view of an indoor lamp unit including an indoor lamp case 11, a glass 12 used in combination with the lamp case 11, and a lamp 13 hermetically sealed by the glass 12 and the lamp case 11.

[0003] Further, since the unsaturated polyester resin composition is inferior in moldability, molded articles comprising a polyethylene terephthalate resin composition or a polybutylene terephthalate resin composition having higher productivity have been used.

[0004]

[Problems to be solved by the invention] However, when the heat capacity of the lamp is large or when the lamp and the molded product are close to each other, the temperature of the molded product becomes high, so that the decomposed product or the compound is removed from the molded product. There has been a problem that they sublime and precipitate on the glass surface combined with the molded product, and the glass surface becomes cloudy. For this reason, the use of polyethylene terephthalate or polybutylene terephthalate resin molded products has been limited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has an object to not only have good surface properties and moldability, but also to prevent the glass surface from fogging even after long-term use. It is to provide a lamp case.

[0006]

Means for Solving the Problems The present inventors diligently studied a lamp case which does not fog the glass surface used in combination, and finally completed the present invention.

[0007] That is, the lamp case of the present invention comprises an epoxy resin of 0.01 to 1 with respect to 100 parts by weight of polyethylene terephthalate and / or polybutylene terephthalate.
A polyester resin composition containing 5 parts by weight and 0 to 100 parts by weight of an inorganic reinforcing material is formed, thereby achieving the above object.

The polyethylene terephthalate and polybutylene terephthalate used in the present invention include:
Not only polymers of ethylene glycol or butylene glycol and terephthalic acid (including derivatives thereof), but also copolymerized polyesters containing at least 80 mol% or more of ethylene terephthalate or butylene terephthalate repeating units. As the copolymerization component, a known acid component and / or glycol component can be used. That is,
Examples of the copolymer component include acid components such as isophthalic acid, naphthalene 1,4 or 2,6 dicarboxylic acid, diphenyl ether 4,4 dicarboxylic acid, adipic acid, and sebacic acid; ethylene glycol, propylene glycol, butylene glycol, and diethylene glycol. , Neopentyl glycol, cyclohexane dimethanol,
Glycol components such as 2,2-bis (4-hydroxyphenyl) propane; oxy acids such as p-oxybenzoic acid and p-hydroxyethoxybenzoic acid.

The polyester resin (polyethylene terephthalate, polybutylene terephthalate) used in the present invention has an intrinsic viscosity of at least 0.4 measured at 30 ° C. with a phenol / tetrachloroethane mixed solvent (6/4 weight ratio). And preferably 0.5 or more. In addition, the above polyester resin is mainly used, and polycyclodimethylene terephthalate, an aromatic polyester such as polyethylene naphthalate, polybutylene adipate, polyethylene adipate, an aliphatic polyester such as polylactone, a polycarbonate or the like, and other thermoplastic resins are mixed. Is also good.

[0010] As the epoxy resin used in the present invention, any compound having an epoxy group in the molecule can be used. For example, glycidyl ether or polyglycidyl ether of polyhydric phenol such as bisphenol A; glycidyl ether or polyglycidyl ether of ethylene oxide or propylene oxide adduct of mono or polyhydric phenol; diglycidyl ether of alkylene glycol; Glycidyl ether; glycidyl ether of alkylene oxide adduct of higher alcohol; glycidyl ether of polyalkylene glycol; polylactone diglycidyl ether;
Copolymer of one or more α-olefins with glycidyl methacrylate; copolymer of one or more monomers selected from α-olefin, alkyl acrylate, methacrylate, and vinyl monomer with glycidyl methacrylate Or a graft polymer. In particular, a diglycidyl ether of a polyalkylene glycol, a copolymer of one or more α-olefins and glycidyl methacrylate, and a glycidyl compound of an ethylene oxide adduct of a polyhydric phenol are preferable.

The compounding amount of the epoxy resin is 0.01 to 15 parts by weight based on 100 parts by weight of the polyester resin. 0.01
When the amount is less than 15 parts by weight, the effect of adding the epoxy resin is small. When the amount exceeds 15 parts by weight, not only the surface properties of the obtained molded article (lamp case) is lowered but also the effect of reducing the amount of precipitation is not improved.

The inorganic reinforcing material used as necessary in the present invention includes fiber reinforcing materials such as glass fiber and carbon fiber, whiskers such as potassium titanate, talc, clay, wollastonite, bentonite, calcium carbonate and the like. Powder reinforcement. Since the inorganic reinforcing material increases the rigidity and heat deformation temperature of the molded product and increases the dimensional stability, 0 to 100 parts by weight is added to 100 parts by weight of the polyester resin depending on the application. If the amount exceeds 100 parts by weight, the appearance of the molded article deteriorates, which is not preferable.

When a lamp case made of a composition containing a usual polyethylene terephthalate resin or polybutylene terephthalate resin is used, a low molecular weight substance contained in the composition during use or a substance generated by thermal decomposition, for example, terephthalic acid Sublimates and precipitates on the glass surface, causing clouding on the glass surface. In the lamp case of the present invention, the fogging is considerably suppressed. Although the reason for this is not clear, it is considered that the epoxy resin acts as a catcher for those low-molecular substances and pyrolytic substances.

The polyester composition may contain additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a lubricant, a flame retardant, an antistatic agent, a release agent, and a colorant according to the purpose and application. preferable.

The method for producing the polyester composition is not particularly limited, and the polyester composition may be produced by any method. For example, after pre-mixing all the components, mixing in an extruder or kneader, or melting any other components into pellets obtained by kneading and blending any number of optional components in an extruder or kneader in advance A method of mixing and the like can be mentioned.

The obtained composition does not require any special molding method or molding conditions, and can be molded under ordinary thermoplastic polyester resin molding conditions, and various molded articles (lamp cases) are molded.

[0017]

Since the lamp case is formed from a resin composition containing a polyethylene terephthalate or polybutylene terephthalate resin, it has good surface properties and moldability. In addition, since the resin composition contains an epoxy resin, low-molecular-weight substances and thermal decomposition substances generated during use are trapped by the epoxy resin.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In addition,
Parts and percentages in the examples are on a weight basis. The heat distortion temperature of the injection molded article was measured according to ASTM D648. Further, the amount of deposition on the glass surface was evaluated as follows.

A molded article of 42 × 42 × 2 mm obtained by injection molding is placed on a hot plate adjusted to a surface temperature of 200 ° C., and covered with a glass weighing bottle of 60φ and 80 mm in height,
Treated for 420 hours. The upper surface of the glass weighing bottle was at about 50 ° C., and white powder mainly composed of terephthalic acid sublimated from the molded product precipitated on the inner surface and was devitrified. The amount of the sublimated precipitate was evaluated from the change in weight of the glass weighing bottle.

(Examples 1 to 11, Comparative Examples 1 to 3) Polyethylene terephthalate resin, polybutylene terephthalate resin, glass fiber, talc, various epoxy resins and montanic acid ester were premixed in the proportions shown in Table 1, It was put into a hopper of a twin-screw extruder and melt-kneaded to obtain a compound chip. This compound chip
After drying at 130 ° C. for 4 hours, a flat plate of a test piece was formed by an injection molding machine adjusted to a cylinder temperature of 270 ° C., and the amount of sublimated precipitates generated was evaluated by the method described above.

The epoxy resins used are as follows.

Epoxy resin I: polyethylene glycol diglycidyl ether epoxy resin II:

[0023]

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Epoxy resin III: bisphenol A diglycidyl ether Epoxy resin IV: lauryl alcohol glycidyl ether Epoxy resin V: ethylene-glycidyl methacrylate 10 mol% copolymer The results are shown in Table 1. In Table 1, the amount of the sublimed substance deposited is represented by% by weight based on the molded product. The load in the measurement of the heat distortion temperature was 18.6 kg / cm ² .

[0025]

[Table 1]

[0026]

[Table 2]

The results shown in Tables 1 and 2 show that the product of the present invention has a reduced amount of sublimation precipitation and maintains transparency. The results corresponded well with the results of the practical test of the lamp case.

[0028]

According to the present invention, it is possible to reduce the amount of sublimate deposited at a high temperature and reduce the fogging of the glass surface while maintaining good surface properties and moldability. Therefore,
The degree of freedom in design is increased, and the device can be used at a high temperature.

[Brief description of the drawings]

FIG. 1 is a plan view of an automobile lamp unit.

FIG. 2 is a front view of the indoor lamp unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp case for automobiles 2 Glass 3 Lamp 11 Lamp case for indoor use 12 Glass 13 Lamp

Claims (1)

(57) [Scope of request for utility model registration] 1. A polyester resin composition comprising 0.01 to 15 parts by weight of an epoxy resin and 0 to 100 parts by weight of an inorganic reinforcing material with respect to 100 parts by weight of polyethylene terephthalate and / or polybutylene terephthalate. Lamp case featuring.