TW201827505A - Inorganic filler-containing resin composition molded body of inorganic filler-containing resin composition and method for producing molded body of inorganic filler-containing resin composition - Google Patents

Abstract

Provided is an inorganic filler-containing resin composite for achieving both strength and decorative properties. The present invention is an inorganic filler-containing resin composite, which comprises at least a thermoplastic resin, an inorganic filler, and a pigment. When a molded body of a test piece having the length of 50 mm, the width of 10 mm and thickness of 1 mm is molded from the resin composite, light transmittance at a wavelength of 700 nm in the thickness direction of the molded body is equal to or less than 8% and lightness L * is 50-90.

Description

   Inorganic filler-containing resin composition, inorganic filler-containing resin composition molded body, and method for manufacturing resin composition molded body containing inorganic filler   

The present invention relates to the provision of a creative resin composition containing an inorganic filler, such as can be used in an electronic device casing; and a molded body formed from the resin composition.

In order to ensure impact resistance or rigidity, as well as creativity and combined processability, a casing of a small electronic device is provided with a molded body formed of a resin composition containing an inorganic filler in a part of a casing formed of metal or the like (patented) Reference 1). In addition, from a creative point of view, in order to make the resin composition containing an inorganic filler compatible with the color of metal parts and the like, a coloring agent such as a pigment is added. In order to adjust the shape of the housing, the part where the formed body is provided is often subjected to a cutting process after the forming.

Although a resin composition containing an inorganic filler has an inorganic filler that maintains the strength of the casing, the inorganic filler that maintains the strength is often needle-like or fibrous. Therefore, according to the molded body, the inorganic filler existing in the surface portion of the molded body is arranged vertically, and the cutting process in this state will expose the cut surface of the inorganic filler to the surface, resulting in an undesired shape, resulting in this appearance. Molded bodies produced by defective products impair productivity.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: WO2011 / 155289

The present invention has been developed to solve the above problems, and an object thereof is to provide a resin composition containing an inorganic filler having both strength and creativity. In addition, a formed body formed from the resin composition and a method for producing the formed body are provided.

The inventors have found that the purpose of the invention can be achieved with the following content.

(1) A resin composition containing an inorganic filler, which contains at least a thermoplastic resin, an inorganic filler, and a pigment. When the resin composition forms a test piece molded body having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm, the thickness of the molded body The light transmittance of light with a wavelength of 700 nm in a direction is 8% or less, and the lightness L * is 50 to 90.

(2) The inorganic filler-containing resin composition according to (1), wherein the pigment is a zinc sulfide-based pigment.

(3) The resin composition containing an inorganic filler according to (1) or (2), wherein the inorganic filler is glass fiber.

(4) An inorganic filler-containing resin composition molded body, which is a molded body molded from the inorganic filler-containing resin composition according to any one of (1) to (3), and the inorganic filler Part of it is exposed on the surface of the molded body.

(5) A molded article of a resin composition containing an inorganic filler, wherein a part of the inorganic filler exposed on the surface of the molded body is a cross section of the filler.

(6) A method for producing a resin composition molded body containing an inorganic filler, which is a method for producing a resin composition molded body containing an inorganic filler according to (4) or (5), including injection molding including an inorganic filler A resin composition of a filler, a procedure for obtaining a molded body, and a procedure for cutting the injection molded body.

The present invention provides an inorganic filler-containing resin composition that can have both strength and creativity.

FIG. 1 is a schematic view of a test piece molded body.

Fig. 2 is a schematic view of a strip-shaped test piece.

Hereinafter, specific embodiments of the present invention will be described in detail.

<< 1. Resin composition containing an inorganic filler >>

The inorganic filler-containing resin composition of the present invention contains at least a thermoplastic resin, an inorganic filler, and a pigment. Thus, the composition containing the inorganic filler forms a 50 mm length, 10 mm width, and 1 mm thickness as shown in FIG. 1. In the case of a test piece formed body, the light transmittance at a wavelength of 700 nm in the thickness direction of the formed body was 8% or less, and the lightness L * was 50 to 90.

The resin composition containing an inorganic filler of the present invention can adjust the light transmittance and color (brightness) of a specific test piece molded body formed using the resin composition to a specific range, thereby reducing the inorganic filler during cutting processing. The resulting appearance is not good. In other words, regardless of injection molding conditions, cutting processing conditions, and the like, the present invention can suppress the occurrence of undesired appearance such as whitening of a part of the surface of the molded body, and reduce the occurrence of defective appearance.

[Transmittance of molded article]

As described above, when the resin composition containing an inorganic filler of the present invention is used to form a specific test piece molded body (FIG. 1) having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm, the wavelength in the thickness direction of the molded body is 700 nm. The light transmittance is 8% or less. Therefore, since the light transmittance of light having a wavelength of 700 nm is 10% or less, the efficiency of reducing the appearance defect caused by the inorganic filler during cutting processing can be exhibited. The light transmittance is preferably 5% or less, and more preferably 3% or less.

[Brightness of the molded body]

Moreover, in the resin composition containing an inorganic filler of this invention, the lightness L * of the said test piece molded object is 50-90. When the L * value is within this range, the creativeness of the formed body can be easily exerted, and the appearance defect caused by the cutting process can be significantly reduced. The lightness L * is preferably 60 to 80.

The light transmittance and lightness L * of a molded article formed from the inorganic filler-containing resin composition of the present invention can be adjusted according to the type and content of the inorganic filler, pigment contained in the resin composition. The components constituting the resin composition containing an inorganic filler are described below.

[Thermoplastic resin]

The thermoplastic resin is not particularly limited, and all general thermoplastic resins can be selected for use.

Examples include polyphenylene sulfide, polypropylene, polyethylene, polyethylene terephthalate, polyamide, polycarbonate, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-benzene Ethylene copolymer, ethylene-vinyl acetate copolymer, polyoxymethylene, polybutylene terephthalate, polyetheretherketone, aromatic polyester fiber, or aromatic polyamidene liquid crystal polymer. Among them, polybutylene terephthalate, polyphenylene sulfide, and a liquid crystal polymer are preferred from the viewpoint of impact resistance or rigidity.

In addition, the content of the thermoplastic resin in the resin composition containing an inorganic filler is not particularly limited, but is preferably 30 to 90% by mass. In order to have both impact resistance, rigidity, and moldability, it is more preferably 40 to 80% by mass. %, Preferably 50 to 70% by mass.

[Inorganic filler]

The inorganic filler may be any of fibrous fillers and non-fibrous fillers (powder and granular fillers, plate-shaped fillers, etc.), or two or more of them may be used in combination. When a resin composition containing an inorganic filler is used in this way, the impact resistance or rigidity of a molded article can be improved.

Among the various inorganic fillers described above, a fibrous filler is preferably used from the viewpoint of providing better impact resistance or rigidity. Among these fibrous fillers, glass fibers are more preferred. The glass fiber to be used may be conventionally known glass fiber, and the shape of the glass fiber tube diameter, cylinder, cocoon section, oval section, etc., or the length of the strand or roving during manufacturing or the glass cutting method are not particularly limited. .

In glass fiber, although the type of glass is not particularly limited, in terms of quality, E glass or corrosion-resistant glass containing silicon in the composition is preferably used. In addition, the fiber length and fiber tube diameter of the glass fiber are not particularly limited as described above, and may be in a general range. For example, the fiber length is 0.1 mm to 6.0 mm, and the fiber tube diameter is 9.0 μm to 15.0 μm. . The average particle diameter of the non-fibrous filler is also not particularly limited, and may be in a general range, for example, from 0.1 μm to 500 μm. Here, before the inorganic filler is mixed with the thermoplastic resin, a CCD camera (for example, a Seichin Co., Ltd., dynamic image analysis method / particle (state) analyzer PITA-3) can be used to take an image and analyze the image to weight the average. The fiber length, fiber tube diameter, and average particle diameter of the non-fibrous filler of the fibrous filler were calculated.

In the resin composition containing an inorganic filler, the content of the inorganic filler is not particularly limited, but is preferably 10 to 70% by mass. In order to have both impact resistance and rigidity, it is more preferably 20 to 60% by mass. It is preferably 30 to 50% by mass.

Further, in addition to providing impact resistance of the molded body, it is possible to use a fibrous filler and a non-fibrous filler in combination, for example, from the viewpoint of greatly reducing bending. In this case, it is preferable to use them in combination, and glass fibers and glass flakes can be used in combination. In addition, when the fibrous filler and the non-fibrous filler are used in combination, the amount of the fibrous filler and the non-fibrous filler is 50 mass parts or more and 100 mass parts relative to the thermoplastic resin of 100 mass parts. The following range is preferable. The ratio of the fibrous filler to the non-fibrous filler can be appropriately selected within a range that does not affect the object of the present invention. From the viewpoint of reducing bending, the length and width of the non-fibrous filler is preferably 1 or more and 10 or less.

[Pigment]

The pigment can be selected from white pigments and colored pigment pigments. In the case of the resin composition containing an inorganic filler of the present invention, a test piece molded body having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm is formed using the resin composition. In order to make the light transmittance of a light beam having a wavelength of 700 nm in the thickness direction of the molded body 8 Below%, use pigments with lower light transmittance.

Specifically, the white pigment may be selected from white pigments of at least one of titanium oxide, zinc sulfide, magnesium oxide, and barium sulfate. Among these, from the viewpoint of dielectric properties (low dielectric loss), titanium oxide, zinc sulfide, or zinc oxide is preferred, zinc sulfide and zinc oxide are more preferred, and zinc sulfide is most preferred.

Pigment pigments can be any organic or inorganic pigment pigments necessary for creativity. For example, according to the Colour Index (C.I .; issued by The Society of Dyers and Colourists), a compound classified as a pigment, specifically, a compound having a Colour Index (C.I.) number is preferably used.

In addition, the average particle diameter of the pigment is not particularly limited, and may be appropriately selected in consideration of shielding properties, dielectric properties, and fluidity when mixed with a thermoplastic resin, and is preferably 0.1 to 15 μm, and more preferably 1 to 10 μm. Before the pigment is mixed with the thermoplastic resin, the average particle diameter of the pigment can be observed with an electron microscope to determine the particle diameter of the pigment particles, and the arithmetic average value of the particle diameter of 1,000 particles can be obtained.

The content of the pigment in the resin composition containing an inorganic filler can be appropriately adjusted without deteriorating the impact resistance, and is preferably 0.4 to 12% by mass, more preferably 1.0 to 10% by mass, and more preferably It is 1.5 to 5 mass%.

The white pigment and the pigment pigment can be used in combination from the viewpoint of dielectric properties and creativity, and the content at this time can be appropriately adjusted without deteriorating the impact resistance.

[Other: additives]

The resin composition containing an inorganic filler of the present invention may include additives generally used, such as a lubricant necessary for molding, if necessary. For example, additives such as antioxidants, stabilizers, nucleating agents, plasticizers, lubricants, release agents, hydrolysis resistance agents, flow improvers, and flame retardants, organic fillers, metal fillers, or thermosetting resins, etc. .

<< 2. Inorganic filler-containing resin composition molded article and manufacturing method thereof >>

The resin composition containing an inorganic filler of the present invention may be a molded body alone or a molded body compounded with a metal part.

Specifically, when the resin composition containing an inorganic filler is a molded body alone, the molding method is not particularly limited. For example, the molded body can be obtained by a method of melt injection molding of a mold. In addition, when a metal part and a resin composition are injection-molded into a composite molded body, various methods such as insert molding, insert molding, and ring molding can be used. In order to improve the adhesion with a metal part when forming a molded body compounded with a metal part, the metal part may be surface-treated in advance. Furthermore, the composite parts are not limited to metals, and inorganic solids such as ceramics and glass can also be used.

Here, in order to adjust the formed body into a final desired shape, the formed body formed of the resin composition containing an inorganic filler can be cut with a general machine. For example, after a resin composition containing an inorganic filler is injection-molded into a molded body, cutting processing is performed to adjust the obtained injection-molded body into a desired shape. At this time, according to the conditions of the injection molding, such as the shape of a mold , Filling temperature, filling speed, orient the vertical direction of the cutting surface of the formed body containing the inorganic filler. In this way, the molded body is injection-molded to orient the inorganic filler. In addition to the shape you want to create, a part (section) of the inorganic filler will be exposed on the surface of the molded body after the cutting process. The desired shape.

The present invention can adjust the constituents of a resin composition containing an inorganic filler as a raw material of a molded body, so that the color of the molded body is within a specific range and the light transmittance is below a specific value, which can exert creativity and suppress undesired shapes happened.

Therefore, the resin composition containing the inorganic filler of the present invention can reduce the occurrence of whitening and the like caused by the inorganic filler when cutting the molded body. Regardless of the conditions of the injection molding and the conditions of the cutting processing, the non- The occurrence of the desired shape finally reduces the appearance of defective products.

In addition, the application of the resin composition containing an inorganic filler of the present invention is not particularly limited. For example, as described above, the resin composition can be used as a housing for a power device or an electronic device, such as a mobile device or a notebook computer. Raw materials that are rigid and require part or all of the components of the design.

[Example]

Hereinafter, the present invention is described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

"Examples and Comparative Examples"

The resin composition containing an inorganic filler is injection-molded, and the injection-molded body is subjected to cutting processing to produce a strip-shaped test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. The composition, injection molding, and cutting conditions of the resin composition containing an inorganic filler are described later and the following table.

<Resin composition containing an inorganic filler>

After the raw material components described below are dry-blended, they are placed in a biaxial extruder molding machine with a cylinder temperature of 260 ° C. After melt-kneading, pelletized resin compositions containing inorganic fillers can be obtained. The content (mass part) of each component is shown in Table 1.

[Thermoplastic resin]

Polybutylene terephthalate (PBT): DURANEX (trademark), manufactured by Wintech Polymer Corporation (IV = 0.75dL / g)

[Inorganic filler]

Glass fiber (GF): ECS03T-747 (chopped strands with a fiber length of 3mm and a fiber diameter of 13μm), manufactured by Japan Electric Glass Co., Ltd.

[Pigment]

Pigment (1): Zinc sulfide-based pigment 1, manufactured by Pigment, Japan

Pigment (2): Zinc sulfide pigment 2, manufactured by Japan Pigment

Pigment (3): Zinc oxide pigment, made by Pigment, Japan

Pigment (4): Soot, manufactured by Mitsubishi Chemical Corporation [MA600B]

Pigment (5): zinc oxide-based white pigment, manufactured by Pigment, Japan

In addition, (1) to (3) are beige, (4) is black, and (5) is white.

<Production of a resin composition molded article (strip test piece) containing an inorganic filler>

At a longitudinal end of a groove having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm, using a mold having a film gate having a width of 10 mm × a thickness of 1 mm, the obtained resin composition containing the inorganic filler was injection-molded to obtain a test. Sheet shaped body. The molding conditions are as follows.

(Molding conditions)

Molding machine: Sodick TR-40VR (longitudinal injection molding machine)

Cylinder temperature: 260 ° C

Mold temperature: 80 ℃

Injection speed: 70mm / s

Holding pressure: 80MPa × 5 seconds

Next, as shown in FIG. 2, the obtained test piece molded body was cut in two directions along the long direction at a position near the center line in the longitudinal (width) direction, and then the cross-section was polished under the following conditions. , A strip test piece having a length of 50 mm, a width of 5 mm, and a thickness of 1 mm was produced.

(Grinding conditions)

Installation: "Ecomet 3" by BUHLER

Abrasive paper: Carbimet # 240, # 400, # 600, UF800, UF1200 made by BUHLER in order

<Evaluation of test piece>

The formed test piece molded body and the strip-shaped test piece were evaluated as follows. Unless otherwise specified, the measurement is performed under the environment of 23 ° C and 50% RH.

[Side determination of light transmittance]

Using a spectrophotometer V-570 integrating sphere device ISN-470 made by JASCO Corporation, the light transmittance of the test piece molded body surface (thickness direction) was measured at a wavelength of 700 nm.

[Color]

The color difference meter SE6000 manufactured by Nippon Denshoku Industries Co., Ltd. was used to measure L * on the surface of the test piece formed body.

[Exterior]

The cross section of the polished strip test piece was visually observed, and 10 samples were produced in the same manner. When one of the samples felt undesired, it was marked with X, and when it was not felt, it was marked with ○.

[Strength (impact resistance)]

The pelletized resin composition was injection-molded under the conditions of a cylinder temperature of 260 ° C and a mold temperature of 80 ° C to produce a simply-supported beam impact test piece, which was evaluated at 23 ° C according to the ISO179 / 1eA standard, at 7kJ / m ² or more. Marked as ○, 5kJ / m ² or more and less than 7kJ / m ^{2 are} marked as △, and less than 5kJ / m ^{2 are} marked as ×.

From the above results, it can be seen that the resin composition of the present invention can have both strength and creativity.

Claims (6)

    A resin composition containing an inorganic filler, which contains at least a thermoplastic resin, an inorganic filler, and a pigment. When the resin composition is used to form a test piece molded body having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm, The light transmittance at a wavelength of 700 nm is 8% or less, and the lightness L * is 50 to 90.         The inorganic filler-containing resin composition according to item 1 of the patent application scope, wherein the pigment is a zinc sulfide-based pigment.         The resin composition containing an inorganic filler according to item 1 or 2 of the scope of the patent application, wherein the inorganic filler is glass fiber.         An inorganic filler-containing resin composition molded body is a molded body formed of the inorganic filler-containing resin composition according to any one of claims 1 to 3 in the scope of patent application, and the inorganic filler A part is exposed on the surface of the formed body.         The molded article of the resin composition containing an inorganic filler according to item 4 of the scope of the patent application, wherein a part of the inorganic filler exposed on the surface of the molded body is a cross section of the inorganic filler.         A method for manufacturing a resin composition molded body containing an inorganic filler, which is a method for manufacturing a resin composition molded body containing an inorganic filler as described in claim 4 or 5 of the scope of patent application, including injection molding including an inorganic filler A resin composition of an agent, a procedure for obtaining an injection molded body, and a procedure for cutting the injection molded body.