JPH04342754A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject polyester resin composition having electroconductivity and antistatic properties and excellent in dimensional accuracy and heat resistance. CONSTITUTION:A polyester resin composition characterized by its composition composed of 100 pts.wt. polyester having the main repeating unit consisting of ethylene terephthalate and/or another polyester having the main repeating unit consisting of butylene terephthalate, 5-40 pts.wt. inorganic filler and 3-30 pts.wt. electroconductive carbon.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a thermoplastic polyester resin composition that imparts conductivity and antistatic properties and has particularly excellent dimensional accuracy and heat resistance, which is useful as a carrier case in the heat treatment process of electronic components, for example. be.

0002

[Background Art] Currently, as electronic devices become smaller,
With the advancement of advanced packaging, IC components are mounted on through-hole boards to increase density, but during the heating process when the IC components are mounted using claw solder,
If an IC component absorbs moisture, bulges, cracks, etc. will occur inside the IC, and the IC component will be damaged. Therefore, before mounting, IC components must be dried at a temperature of 100° C. or higher to remove moisture.

[0003] As carrier cases conventionally used in the IC drying process, conductive resins such as vinyl chloride, polystyrene, and polypropylene are used, but in this case, they do not have heat resistance above 100°C.
After being transferred to an aluminum die-cast carrier case and dried, it was transferred again to the case before being shipped, which required an extra step. In addition, when using conductive polyphenylene ether resin as the carrier case, it has a heat resistance of 100°C or higher, so it can be dried without being transferred to an aluminum die-cast carrier case.
Since it can only be processed at temperatures of around 120-130℃,
It required a long processing time of 72 to 96 hours, which was not efficient.

[0004] In addition, polyamide resins themselves have high hygroscopicity and are unsuitable for this purpose, and polycarbonate resins have poor fluidity and tend to warp in molded products, lacking dimensional stability. Other highly heat-resistant resins include polyphenylene sulfide, polyether sulfone, and polyarylate, but all of these are expensive and have not been put into practical use.

[0005]

[Problems to be Solved by the Invention] Therefore, the present invention provides 15
The goal is to obtain a composition that has heat resistance of 0°C or higher and is suitable as a substitute for expensive aluminum die-cast carrier cases.If this problem can be solved, the drying temperature can be increased to 150°C or higher. Since it can be fully dried in about 24 hours, it will greatly contribute to the industry by simplifying the process of transferring to an aluminum die-cast carrier case and shortening the drying time.

[0006]

[Means for Solving the Problems] As a result of intensive research and examination in order to solve the above-mentioned problems, the present inventors have finally completed the present invention. That is, the present invention contains 100 parts by weight of a polyester whose main repeating unit is ethylene terephthalate and/or a polyester whose main repeating unit is butylene terephthalate, 5 to 40 parts by weight of an inorganic filler, and 3 to 30 parts by weight of conductive carbon. This is a polyester resin composition characterized by the following.

The polyester having ethylene terephthalate as the main repeating unit and/or the polyester having butylene terephthalate as the main repeating unit used in the present invention contains terephthalic acid,
The glycol component is obtained from ethylene glycol and/or butylene glycol, but other known acid components and/or glycol components can be used as copolymerization components of about 20 mol% or less. Acid components such as isophthalic acid, naphthalene 1,4 or 2,6 dicarboxylic acids, diphenyl ether, 4,4 dicarboxylic acids, adipic acid, sebacic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, cyclohexane dicarboxylic acid, etc. Examples include methanol, glycol components such as 2,2-bis(4-hydroxyphenyl)propane, and oxyacids such as P-oxybenzoic acid and P-hydroxyethoxybenzoic acid. The polyester having ethylene terephthalate as a main repeating unit used in the present invention has an intrinsic viscosity of usually 0.4 or more, preferably 0. The intrinsic viscosity of polyester containing butylene terephthalate as a main repeating unit is usually 0.5 or more, preferably 0.7 to 1.3.

The inorganic fillers used in the present invention include talc, graphite,
Examples include wollastonite, clay, mica, montmorinite, kaolin, calcium silicate, shirasu balloons, short glass fibers, glass beads, silica, stone blue, molybdenum disulfide, and metal carbides, but talc is preferred due to its heat resistance and impact strength. , mica, and wollastonite are particularly preferred. The particle size of the filler is preferably 30 μm or less on average from the viewpoint of appearance and physical properties. Further, in the present invention, glass fibers, carbon fibers, graphite fibers, metal carbide fibers, metal nitride fibers, aramid fibers, phenolic resin fibers, etc. may be further blended as fibrous reinforcing materials, and glass fibers are particularly preferred. . The diameter thereof is usually 15 μm or less, and it is preferable to have a surface treatment for plastic reinforcement or a focusing treatment. The inorganic filler is contained in an amount of 5 to 40 parts by weight, preferably 8 to 30 parts by weight. If it is less than 5 parts by weight, heat resistance will be insufficient, and if it exceeds 40 parts by weight, fluidity, elongation, and deflection will decrease, making it difficult to obtain a good molded product.

[0009] The conductive carbon in the present invention imparts high conductivity when filled into a resin and significantly reduces the surface resistance of the resin, and acetylene black, furnace black, etc. are preferably used. Specifically, the furnace blacks include Ketjenblack EC (product name of Akzo, Netherlands) and HS-500.
(Asahi Carbon Co., Ltd. product name), Vulcan XC72 (USA CA
There are commercially available products such as BOT (trade name). In the present invention, the conductive carbon is contained in an amount of 3 to 30 parts by weight, preferably 4 to 20 parts by weight. If it is less than 3 parts by weight, the conductivity is insufficient;
If it exceeds 30 parts by weight, fluidity and mechanical strength will decrease, making it difficult to obtain a good molded product.

Depending on the purpose and use, the polyester resin composition of the present invention may contain known antioxidants, ultraviolet absorbers, plasticizers, lubricants, flame retardants, antistatic agents, mold release agents, colorants, etc. Aromatic polyesters such as polyethylene naphthalate, polybutylene adipate,
Other thermoplastic resins such as aliphatic polyesters such as polyethylene adipate and polylactone, and polycarbonate may be mixed.

[0011] The composition of the present invention can be obtained by any method without particular limitation. For example, a method in which all components are premixed and then kneaded in an extruder or kneader, or a method in which arbitrary components are kneaded and blended in an extruder or kneader in advance, resulting in pellets, and then the remaining components are melt-mixed. etc. In addition, when producing molded products using the polyester resin composition of the present invention, no special molding method or molding conditions are required, and the molding can be performed satisfactorily under the molding conditions of ordinary thermoplastic polyester resins, and it is possible to form a plate-shaped product. , various molded products such as containers.

0012

[Examples] The present invention will be explained in more detail with reference to Examples below. Note that the properties of the obtained composition were evaluated by the following method. (1) ASTM D- as heat deformation temperature bending stress 4.6kg/cm2
648. (2) Deformation and warpage of molded product (IC carrier case) A carrier case of 300 x 150 mm was heated at 150°C at 24°C.
After leaving it in the dryer for an hour, place it on a flat plate to deform and
and warping was observed. (2mm or less is considered acceptable) (
3) Mechanical strength of the molded product The molded product was allowed to fall naturally onto concrete from a height of 2 m and the presence or absence of damage was observed. (4) Surface specific resistance of molded product Measured using a two-point terminal surface specific resistance measuring device.

Examples 1 to 8, Comparative Examples 1 to 5 Polyethylene terephthalate resin (intrinsic viscosity 0.62), polybutylene terephthalate resin (intrinsic viscosity 1.1), glass fiber, talc, wollastonite, Ketjenblack EC After premixing in the proportions shown in Table 1, the mixture was charged into a hopper of a twin-screw extruder and melt-kneaded at a cylinder temperature of 270°C to obtain compound chips. After drying this compound chip at 130℃ for 4 hours, the cylinder temperature was 26℃.
A test piece and an IC carrier case were molded using an injection molding machine adjusted to 0-265-270°C. The characteristic evaluation is also listed in "Table 1".

[Table 1]

[0014]

Effects of the Invention As is clear from Table 1, the composition of the present invention has a high heat distortion temperature, excellent moldability, no deformation or warping even at high temperatures of 150°C or higher, and a low specific surface resistance value. It can be seen that it is less than 107 Ω. Therefore, the polyester resin composition of the present invention has electrical conductivity and antistatic properties,
Due to its excellent dimensional accuracy and heat resistance, it is particularly useful as a carrier case for electronic components.

Claims (1)

[Claims] Claim 1: Contains 100 parts by weight of a polyester whose main repeating unit is ethylene terephthalate and/or a polyester whose main repeating unit is butylene terephthalate, 5 to 40 parts by weight of an inorganic filler, and 3 to 30 parts by weight of conductive carbon. A polyester resin composition characterized by: