JPH0218454A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition giving a molded article having excellent surface appearance and mechanical properties and suitable for the field of camera, VTR, etc., by compounding a specific amount of glass fiber having specific fiber diameter. CONSTITUTION:A thermoplastic resin (e.g. polycarbonate or polyethylene) is compounded with 2-50wt.%, preferably 8-40wt.% of glass fiber having an average fiber diameter of <=2mum, made of preferably E glass and surface-treated with a silane-coupling agent.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thermoplastic resin composition that has an excellent surface appearance and improved mechanical properties when formed into a molded article, and its excellent surface properties. Due to its dimensional stability, mechanical strength, electrical properties, etc., it can be suitably used in a wide range of industrial fields such as cameras, VTRs, and facsimiles.

[Conventional technology and its problems]

Conventionally, glass fiber reinforced thermoplastic resin compositions have excellent mechanical and electrical properties. However, when used for parts such as housings and covers that require good appearance performance,
In order to give it a good appearance, it was necessary to perform secondary processing such as painting or printing to make it beautiful.

As an improvement method for this, a method has been proposed in which a polycarbonate oligomer with a lower melt viscosity than the polycarbonate resin is added to the polycarbonate resin, and the oligomer component with a low viscosity is dispersed on the surface of the molded product (Japanese Patent Laid-Open No. 58 -111549), but the improvement effect was not necessarily sufficient, and there was a drawback that the blended oligomer caused a decrease in heat resistance.

Furthermore, conventional glass fiber-reinforced thermoplastic resin compositions have a large anisotropy in molding shrinkage, which has the disadvantage of causing warpage in molded products, and there are limitations in applications that require dimensional accuracy. Ta. Therefore, in order to improve the anisotropy of the molding shrinkage rate, spherical glass fillers such as glass beads and glass balloons are used together, but there is little improvement in mechanical strength and there is no improvement in appearance. was insufficient.

As mentioned above, the drawbacks of glass fiber-reinforced thermoplastic resin compositions are presumed to be due to the fact that the conventionally used glass fibers usually have an average wU fiber diameter of 6 to 13-1 and a fiber length of 701 mm to 701 mm. , it was difficult to obtain materials with less anisotropy in appearance.

[Means for solving problems]

The inventors of the present invention have arrived at the present invention as a result of intensive studies on methods for solving the above-mentioned drawbacks.

That is, in the present invention, the thermoplastic resin has an average fiber diameter of 2.
- A thermoplastic resin composition containing 2 to 50% by weight of the following glass fibers, the glass fibers being made of E glass, and further surface-treated with a silane coupling agent. It is something.

The configuration of the present invention will be explained below.

First, the glass fibers with an average fiber diameter of 2 mm or less, which is a feature of the present invention, are those that are normally difficult to manufacture using the long fiber spinning method, and are usually melted using the short fiber flame method, that is, in a glass melting furnace. The glass is drawn out as a filament with a desired uniform diameter from a porous plate, and then introduced into a high-temperature, high-speed burner flame to form fibers, thereby obtaining cotton-like ultrafine glass fibers.The average fiber diameter is 2.
It is a unique glass fiber that is extremely fine and has a large specific surface area. Further, as the raw material for the present glass fiber, alkali-free glass such as E glass is preferable. This is because when C glass or the like is used, the deterioration and decomposition of the resin is promoted due to the promotion of alkaline hydrolysis by the glass fibers, resulting in a decrease in physical properties.

Furthermore, it is preferable to use a surface treatment agent such as a silane coupling agent in order to improve the adhesion between the glass fiber and the resin. Unlike conventional glass fibers, this glass fiber does not normally use a binder such as a sizing agent, so it has the advantage of being able to be surface-treated as is. To give an example of a specific surface treatment method, glass fibers are immersed in an aqueous solution of 0.01 to Iwt% of silane coupling such as aminosilane, epoxysilane, acrylic silane, vinyl silane, etc., and then treated at a temperature of 140 to 160°C. 1-2 o'clock,
For example, there is a method of intermittent heat treatment.

Specific examples of E glass fibers having an average fiber diameter of 2 or less include B-PMW-800 and 13-FMW-1 manufactured by Nippon Inuki.
I can list 700.

Glass fiber diameter is 2. If it exceeds ta, the appearance of the molded product will become rough, which is not preferable.

The thermoplastic resin of the present invention blended with the above-mentioned novel glass fibers is not particularly limited as long as it is a resin that is normally used as a fiber-reinforced resin composition, and the thermoplastic resin of the present invention has improved mechanical appearance. It can be used as a composition with good strength. A specific example is polyethylene (=PR
> Olefinic polymers exemplified by polypropylene (=PP), polybutene, polyisobutylene, polymethylpentene-1, ethylene-propylene copolymer, etc.; ethylene-vinyl acetate copolymer (=BVA), ethylene-acetic acid Vinyl-vinyl chloride copolymer, polyvinyl acetal, polyvinyl acetate (=PVA), vinyl alcohol-vinyl acetate copolymer, polyvinyl chloride (=PVC)
Substituted olefin polymers such as; chlorinated polyethylene,
Chlorinated polyolefin polymers such as chlorinated polypropylene and chlorinated polyvinyl chloride; polytetrafluoroethylene (=PTFB), polytetrafluoroethylene-propylene copolymer, vinylidene fluoride resin, polytetrafluoroethylene-hexafluoropropylene Difluororesins such as copolymers; polymethyl methacrylate (=PMMA
), copolymers of methyl methacrylate as a main component with ethyl acrylate, n-butyl acrylate, etc., acrylate polymers such as polyethyl acrylate, polybutyl acrylate; polystyrene (=PS), high impact polystyrene (= HIPS), methyl methacrylate-styrene copolymer (=MS), acrylonitrile-styrene copolymer (=AS), acrylonitrile-butadiene-styrene copolymer (=ABS), methyl methacrylate-butadiene-styrene copolymer (=ABS)
=MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (=MABS), methyl methacrylate-alkyl acrylate rubber-styrene copolymer (=MAS), and others JP-A-48-48
Styrenic polymers such as the acrylonitrile-acrylic rubber-styrene copolymer disclosed in JP-A No. 547, the acrylonitrile-chlorinated polyolefin-styrene copolymer disclosed in JP-A-48-42452; nylon; 6 (=PAD6), nylon-66 (=
PAD66), nylon-12 (=PAD12), nylon-6,12, nylon-11, MX polyamide (=
Polyamide resins such as MXD6); polyethylene terephthalate (=PUT), polybutylene terephthalate (=PBT), and polyesters of cyclohexane dimetatool or phthalic acid using ethylene glycol and the like as the diol component. PCTA,
Saturated polyester resins (PCTG), etc.
=PBS); Liquid crystal polymer such as a copolymer of polyhydroxybenzoic acid and polyethylene terephthalate; Polyacetal (=POM); Polyvinyl acetal;
Polyester imide, polyamide imide, polyarylate, polyether ketone, polyester carbonate,
Needle polysulfone, polyether sulfone, polycarbonate (=PC), polyphenylene ether (=P
PE), heat-resistant engineering plastics such as polyphenylene sulfide, and mixtures of one or more selected from the above, such as PC
PC/styrenic copolymer compositions such as /ABS, PC/MBS, PC/PBT, PC/PBT, PC/PC
PC/polyester resin compositions such as TA, PC/PCTG, diene rubber, acrylic rubber, particulate rubber or olefin elastomer obtained by crosslinking these, thermoplastic styrene-butadiene copolymer, polyester Polycarbonate resin compositions, typically those blended with thermoplastic elastomers such as elastomers, PPE/PS, PPE/H1-PS and other polyphenylene ether resin compositions, compositions such as P[1M/polyurethane elastomers, Other thermoplastic resins may be mentioned. Among these thermoplastic resins, polycarbonate (PC), polyethylene terephthalate (PUT), polybutylene terephthalate (
General-purpose engineering plastics such as saturated polyesters such as PBT, polyamides, polyacetals, and polyphenylene ethers, and compositions thereof are preferred, and polycarbonates and compositions thereof are particularly preferred;
As a polycarbonate resin, the viscosity average molecular weight is 19.0
00 to 30,000 is preferably used.

The amount of the glass fiber of the present invention added to the thermoplastic resin is in the range of 2 to 50% by weight of the composition, more preferably 5 to 4% by weight.
It is preferable to select from a range that accounts for 5% by weight, particularly 8 to 40% by weight.

When the blending amount is less than 2% by weight, dimensional accuracy (low shrinkage rate),
There is no improvement effect on strength, rigidity, etc., and on the other hand, if it exceeds 50% by weight, the fluidity is insufficient and molding becomes difficult, the wear of molds and cylinders becomes severe, which is economically disadvantageous, and the thermoplastic resin This is not preferable because deterioration occurs and mechanical strength etc. decrease.

Further, there are no particular limitations on the method for preparing the thermoplastic resin composition of the present invention, and a conventional method may be used, for example, after mixing the thermoplastic resin and the present glass fiber in a V-blender or the like,
Commonly used industrial methods include pelletizing with a single-screw extruder equipped with a vent, and feeding glass fiber from the middle of a -screw extruder or twin-screw extruder, mixing it in the extruder, and pelletizing it. Methods are adopted as appropriate.

These thermoplastic resins may contain lubricants such as fatty acid esters, paraffin wax, and silicone oil, heat stabilizers, antioxidants, light stabilizers, colorants, inorganic fillers, carbon fibers, and electrostatic charges as necessary. Additives such as inhibitors can of course be added.

〔Example〕

This will be explained below using Examples and Comparative Examples. Note that "parts" in Examples and Comparative Examples are based on weight unless otherwise specified.

Examples 1 to 4 and Comparative Examples 1 to 3 Polycarbonate resin powder using bisphenol A (manufactured by Mitsubishi Gas Chemical Co., Ltd., Kneepilon E-2000, viscosity average molecular weight 28.000), E glass fiber with an average fiber diameter of 0.8 mm (manufactured by Nihon Muki ■, E-FMW-800, hereinafter referred to as A
), glass fiber A surface-treated with an aminosilane coupling agent manufactured by Nippon Unicar (hereinafter referred to as B), E glass fiber with an average fiber diameter of 13ρ (manufactured by Asahi Fiberglass ■, C303,409, hereinafter referred to as B). , C) and glass beads (manufactured by Toshiba Ballotini, EGB 731)
, hereinafter referred to as D) were mixed in the compositions shown in Table 1 and extruded into pellets using a -shaft extruder.

The obtained pellets were dried at 120°C in a hot air dryer at 120°C.
After drying for more than an hour, test pieces for measuring physical properties were molded using an injection molding machine and tested for physical properties.

The results are shown in Tables 1-1 and -2.

The appearance (material) in the table is shown below.

○: Surface smooth.

△D Roughness in some areas.

×: Surface rough.

Table 1-1 Table 1-2 Pieces were molded and physical properties tested.

The results are shown in Table 2. Note that the appearance (material) is the same as described in Table 1.

Example 5.6 and Comparative Example 4.5 Modified polyphenylene ether resin (manufactured by Mitsubishi Gas Chemical ■,
Iupiace AH-60), polyacetal resin (manufactured by Mitsubishi Gas Chemical Company, Iupital F, 3O-01), glass fibers A1 and glass fiber C were mixed in the composition shown in Table 2, and extruded in the same manner as in Example 1. Test for measuring physical properties by pelletizing and injection molding [Operations and effects of the invention] As described above, the thermoplastic resin composition of the present invention has improved appearance by using glass fibers with an average fiber diameter of 2p or less. It exhibits physical properties such as excellent properties, low anisotropy, and high mechanical strength, which are characteristics not found in conventional glass fiber reinforced materials.

Therefore, the composition of the present invention can be used in cameras, VTRs.

It can provide public materials for a wide range of industrial fields such as facsimile.

Claims (1)

[Scope of Claims] 1. A thermoplastic resin composition comprising 2 to 50% by weight of glass fibers having an average fiber diameter of 2 μm or less added to a thermoplastic resin. 2. The thermoplastic resin composition according to claim 1, wherein the glass fiber is made of E glass. 3. The thermoplastic resin composition according to claim 1, wherein the glass fibers are surface-treated with a silane coupling agent.