JP2605071C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a resin composition for injection molding, which is made of a thermoplastic resin and can be obtained by injection molding to obtain a light-weight molded article. [Related Art] Among thermoplastic resins, for example, polyphenylene sulfide resin, polyphenylene oxide resin, polyetherimide resin, polyether sulfone resin, aromatic polyester resin, polycarbonate resin, etc. have excellent heat resistance.
Moreover, it has excellent moldability such as melt heat stability and mold release properties. Electric and electronic products or automotive parts are molded from resin compositions containing fillers such as inorganic fibrous materials and fine powders, and are practically used. Has been provided. However, depending on the purpose of use, it is necessary to obtain a molded product with improved strength and molding shrinkage, and a reduced linear expansion coefficient. In such a case, the amount of the filler in the resin composition is increased to cope with the problem. However, as a result, the specific gravity of the molded article becomes high. Such a molded product having a large specific gravity can be an advantage such as smooth rotation of a gear or the like that moves by inertial force,
On the other hand, it is disadvantageous for components that operate with low power or electrical components that require strict correspondence to electrical signals. In order to solve the above-mentioned disadvantages, as a lightweight filler, for example, a hollow sphere filler such as a glass balloon, a shirasu balloon, and a carbon balloon is filled with a thermosetting resin such as a liquid polyester resin or an unsaturated polyester resin. It is being done against. Such a liquid resin composition is generally formed into a molded product by casting using a mold or press-forming a preformed prepreg. However, thermoplastic resins that can be injection molded have a much higher molecular weight than thermosetting resins, and therefore have higher melt viscosities. The hollow sphere is destroyed at the time of injection molding or injection molding, and there is a problem that it hardly contributes to the reduction of the weight of the molded product. [Problems to be Solved by the Invention] The present invention is intended to solve the above-described problems, and a resin composition in which a hollow sphere filler is filled in a thermoplastic resin that can be injection-molded. It is an object of the present invention to provide a thermoplastic resin composition capable of achieving weight reduction of a molded article. [Means for Solving the Problems] That is, the present invention provides a polyphenylene sulfide resin, a polyether sulfone resin
A polycondensation type thermoplastic resin having an aromatic nucleus selected from fats and polyetherimide resins (hereinafter, referred to as a specific thermoplastic resin) , a hollow sphere filler and a polyethylene resin, or a specific thermoplastic resin, a hollow sphere filler A resin composition comprising a filler other than hollow spheres and a polyethylene resin, wherein the polyethylene resin is 0.1 to
An object of the present invention is to provide an injection molding resin composition containing 5% by weight. In the present invention, the specific thermoplastic resin can be usually formed by injection molding, but the injection molding is preferably carried out at a cylinder temperature of 240 ° C. or higher. And Thus, precision moldability in various Naru use as moldings, heat resistance, a tree butter may address and dimensional stability against change in the mechanical strength and environmental conditions. Why a particular thermoplastic resin used in the present invention, the specific thermoplastic resins Where <br/> called, is what is referred to as a heat-resistant resin, in molding, be a high temperature cylinder temperature especially in injection molding This is because, at such a high temperature, the polyethylene resin exerts the following effects on the hollow sphere filler contained in the resin composition. The hollow sphere filler is used for various purposes as hollow spheres using various materials, such as glass, silica, alumina silica, alumina, zirconia, shirasu, phenol resin, urea resin, vinylidene chloride-acrylonitrile. Some are made of a copolymer resin or the like. Thus, the thermoplastic resin has a cylinder temperature of 240 ° C or higher in injection molding, and has a high melting temperature and high melt viscosity, so it has excellent heat resistance as a hollow sphere filler. In addition, it is desirable that they have pressure resistance. Accordingly, glass balloons, silica balloons, carbon balloons, shirasu balloons, and the like, which are inorganic materials such as glass, silica, and alumina and are easily available and advantageous in cost, are preferable. Such hollow sphere fillers are commercially available, for example, in glass balloons,
"Glass Bubbles" (Sumitomo 3M), "3M Glass Bubbles" (3M, USA), "Glass Micro Balloon" (Emerson Cumming, USA), and "Crecas Fair" (Kureha Chemical Co., Ltd.) for carbon balloons ),
"Carbon Sphere" (General Technology, USA) and the like. The hollow sphere filler has an average particle diameter of 200 because the resin composition containing it is used for injection molding and is applied to the molding of precision molded products.
μm or less, and more preferably 100 μm or less. The blending amount of the hollow sphere filler is appropriately determined depending on the intended degree of weight reduction of the molded article obtained by molding the resin composition for injection molding of the present invention. In consideration of the above, the content is preferably 5 to 80% by weight based on the specific thermoplastic resin. The polyethylene resin contained in the resin composition for injection molding in the present invention is not particularly limited, and may be either high density or low density, and can be used regardless of the size of the melt flow rate. However, in the case of a resin requiring a particularly high molding temperature in injection molding of a thermoplastic resin, a resin having a large melt flow rate is more desirable. This polyethylene resin has a sufficient effect in the range of 0.1 to 5% by weight in the resin composition. If the amount is less than 0.1% by weight, the uniform dispersibility during preliminary mixing or extrusion kneading is poor, and the reproducibility of the effect is poor. On the other hand, if it exceeds 5% by weight, it may cause gas generation during kneading or molding. The form at the time of blending the polyethylene resin is not particularly limited,
It is preferable that the powder is a powder from the viewpoint of easy handling in operation. Polyethylene resin can be injection molded as a thermoplastic resin, but the preferred temperature of the cylinder in injection molding is 220 ° C. Thus, in the present invention, since the specific thermoplastic resin is suitably molded at a cylinder temperature of 240 ° C. or higher in injection molding, the polyethylene resin is converted from a molten state to a liquefied state at such a high molding temperature. It is in a state. As a result, as the polyethylene resin is liquefied lubricant between the specific <br/> thermoplastic resin and hollow spheres filler in a molten state in the cylinder at a temperature of above 240 ° C. in the injection molding of a specific thermoplastic resin It is presumed that this acts to prevent the hollow sphere from breaking. By the way, those which exhibit a lubricating action in a liquefied state at a high temperature as described above and which do not decompose particularly at 240 ° C. or higher cannot be found with other materials. The resin composition for injection molding of the present invention contains a polyethylene resin in a resin composition comprising a specific thermoplastic resin and a hollow sphere filler, but the above resin composition further contains fillers other than hollow spheres, For example, fibrous reinforcing materials such as fibers made of glass fiber, carbon fiber, potassium titanate, asbestos, silicon carbide, silicon nitride, and ceramic fibers, calcium carbonate, calcium silicate, magnesium carbonate, magnesium oxide, zinc oxide, titanium oxide , Antimony trioxide, kaolin,
Clay, Pa Irofiraito, bentonite, sericite, zeolite, mica,
Inorganic fillers such as mica, nepheline sinite, talc, wollastonite, ferrite, stone, quartz powder, glass beads, glass flakes, etc. can also be included. The amounts of these components are set so as to substitute a part of the hollow sphere filler in the resin composition. Further, a small amount of a releasing agent, a lubricant, a heat stabilizer, a weather resistance improving agent, and the like can be contained. In the resin composition for injection molding of the present invention, a resin composition comprising a specific thermoplastic resin, a hollow sphere filler and a polyethylene resin, and a filler and the like optionally further blended and kneaded to form a resin composition. Is not particularly limited, and a mixer usually used for mixing powdery substances, such as a Hensiel mixer, a tumbler mixer,
It can be performed by a method of mechanically and uniformly mixing with a V-type mixer or the like. Next, the mixture is put into a screw-type single-screw or twin-screw kneading extruder,
After being melt-kneaded and extruded into a strand shape, it is cooled and formed into a pellet-shaped molding material by a pelletizer, so that it can be suitably used for injection molding, and a lightweight molded product can be obtained. [Examples] Raw materials used in Examples and Comparative Examples are summarized below. Polyphenylene sulfide resin [abbreviated as PPS]: “Ryton PR-06”
(Manufactured by Philips Petroleum, USA) Polyethersulfone resin [abbreviated as PES]: “Biftrex PES 300P
"(UK ICI Ltd.) [abbreviated as PEI] polyetherimide resin:" Ultem 1000 "(US General Electric Co.) glass balloons:" Glass Bubbles SSX "(manufactured by Sumitomo 3M Ltd.) Carbon Balloon:" Kurekasu Fair A-200 "(manufactured by Kureha Chemical Co., Ltd.) Polyethylene resin [abbreviated as PE]:" Grade YF-30 "(manufactured by Mitsubishi Yuka Co., Ltd.) Glass fiber [abbreviated as GF]: "CS-03MA497" (manufactured by Asahi Fiberglass) Carbon fiber [abbreviated as CCF]: "HTA-C6-S" (manufactured by Toho Rayon) Example 1 6 and Comparative Examples 1 to 3 A predetermined amount was weighed out as the compounding ratio shown in Table 1 and preliminarily mixed with a V-type mixer, and then the extruder (medium) was set at a cylinder temperature of 300 ° C. Machinery Co., Ltd.,
The mixture was put into a hopper having a screw diameter of 30 mm) and kneaded and extruded to obtain pellets. Then
The pellets were injection molded using a 3 oz. Injection molding machine (manufactured by Nippon Steel Works) having a cylinder temperature of 320 ° C. and a mold having a mold temperature of 135 ° C. to obtain a 25 mm × 75 mm × 3 mmt. A test piece was obtained. The specific gravity of the test piece thus obtained was measured by an underwater displacement method (based on JIS K 6911). Table 1 shows the results. From Table 1, it is found that Examples 1 to 6 have extremely low specific gravities, and that Comparative Examples 1 and 5 were obtained in the same manner as Examples 1 to 4 except that PE was not blended. Each of Comparative Example 2 and Comparative Example 3 obtained in the same manner as in Example 6 had a higher specific gravity than the corresponding example, and the effect of reducing the weight of the molded article by blending PE was recognized. Examples 7 and 8 and Comparative Examples 4 and 5 The raw materials were weighed out in a prescribed ratio as shown in Table 2 and preliminarily mixed with a V-type mixer. Test pieces were obtained in the same manner as in Examples 1 to 6, except that the temperature and the mold temperature were set to the temperatures shown in Table 2. The specific gravity of this test piece was measured in the same manner as in Examples 1 to 6, and the results are shown in Table 2. From Table 2, the influence of the specific gravity on the molded product is apparent depending on whether or not 1% of PE is added. In Examples 7 and 8 , the effect of reducing the weight of the molded product is recognized. [Effect of the Invention] The resin composition for injection molding of the present invention is excellent in moldability such as low molding shrinkage, melt stability and mold release properties, and is particularly lightweight and has excellent mechanical strength, rigidity and low heat. This has the effect of enabling molding of a molded article having an expansion coefficient. Therefore, by applying the resin composition to molding of equipment and components in various fields such as space and aviation equipment, automobiles, office equipment, information equipment, medical equipment, electric and electronic equipment, general industrial equipment, etc. Weight reduction can be achieved. More specifically, an effect that a high specific elasticity (elastic modulus / specific gravity) can be sufficiently exerted by applying the present invention to the molding of a high-precision vibration component, for example, an actuator of an optical pickup or the like is also recognized.

Claims (1)

Claims 1) Polyphenylene sulfide resin, polyether sulfone resin, and polyether
A resin composition comprising a polycondensed thermoplastic resin having an aromatic nucleus selected from terimide resins , a hollow sphere filler and a polyethylene resin, wherein the polyethylene resin is contained in an amount of 0.1 to 5% by weight for injection molding. Resin composition. 2. The composition according to claim 1, wherein the hollow sphere filler is contained in an amount of 5 to 80% by weight based on the polycondensation thermoplastic resin having an aromatic nucleus. 3) Polyphenylene sulfide resin, polyether sulfone resin, and polyether
A polycondensation-based thermoplastic resin having an aromatic nucleus selected from a terimide resin , a hollow sphere filler, a filler other than the hollow sphere filler, and a polyethylene resin, wherein the polyethylene resin is 0.1 to 5 A resin composition for injection molding, which is contained by weight. 4) The composition according to claim 3, wherein the hollow sphere filler is contained in an amount of 5 to 80% by weight based on the polycondensation thermoplastic resin having an aromatic nucleus.