KR20180042139A - 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

FIELD OF THE INVENTION [0001] The present invention relates to an inorganic filler-containing resin composition, an inorganic filler-containing resin composition molded article, and an inorganic filler-containing resin composition molded article having a filler- RESIN COMPOSITION}

The present invention relates to an inorganic filler-containing resin composition, which is used for a casing for an electronic device, to which designability is imparted, a molded article molded from the resin composition, and the like.

In order to provide designability and assembly processability while ensuring impact resistance and rigidity, a compact body made of an inorganic filler-containing resin composition is provided on a part of a case made of a metal or the like One). In addition, a coloring agent such as a pigment may be added to such an inorganic filler-containing resin composition in order to match the color tone with a metal part or the like from the standpoint of designability. In many cases, the portion provided with such a molded body is subjected to cutting after molding in order to adjust its shape as a case.

The inorganic filler-containing resin composition contains an inorganic filler in order to maintain the strength of the case. The inorganic filler for maintaining the strength is often needle-like or fibrous. Therefore, depending on the formed article, the inorganic filler existing on the surface portion of the formed article is vertically oriented and is cut in that state, so that the cut surface of the inorganic filler is exposed on the surface to cause an unintended design , Resulting in appearance defective products, which may impair the productivity of the molded article.

WO2011 / 155289

The present invention has been made to solve the above problems, and an object thereof is to provide an inorganic filler-containing resin composition for achieving both strength and design. Further, it is intended to provide a molded article by the resin composition and a method for producing the molded article.

The present inventors have led to achieve the object of the present invention as follows.

(1) A resin composition containing an inorganic filler, wherein at least a thermoplastic resin, an inorganic filler, and a pigment are contained, and a molded product of the test piece having a length of 50 mm, a width of 10 mm and a thickness of 1 mm is molded by the resin composition, Having a light transmittance at a wavelength of 700 nm in a thickness direction of 8% or less and a lightness L * of 50 to 90. The inorganic filler-

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

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

(4) A molded article obtained by molding the inorganic filler-containing resin composition according to any one of (1) to (3), wherein a part of the inorganic filler is exposed on the surface of the molded article.

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

(6) A process for producing a molded article of an inorganic filler-containing resin composition as described in (4) or (5) above, which comprises the steps of obtaining an injection-molded article by injection molding an inorganic filler-containing resin composition and a step of cutting the injection- A method for producing a molded article of an inorganic filler-containing resin composition.

According to the present invention, it is possible to provide an inorganic filler-containing resin composition that combines strength and designability.

1 is a schematic view of a molded body of a test piece.
2 is a schematic view of a strand-like test piece.

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

«1. Inorganic filler-containing resin composition »

The inorganic filler-containing resin composition of the present invention comprises at least an inorganic filler, a thermoplastic resin, and a pigment. With such an inorganic filler-containing composition, as shown in Fig. 1, The light transmittance at a wavelength of 700 nm in the thickness direction of the molded article is 8% or less and the lightness L * is 50 to 90. [

In the inorganic filler-containing resin composition of the present invention, by adjusting the light transmittance and the color (brightness) of a specific test piece molding to be molded using the resin composition to be within a specific range, occurrence of appearance defects Can be reduced. That is, irrespective of conditions such as injection molding conditions, cutting conditions, and the like, it is possible to suppress unintentional appearance such as whitening of a part of the surface of the molded article, and consequently to reduce occurrence of appearance defective products.

[Light transmittance of molded article]

When the inorganic filler-containing resin composition of the present invention is molded from a specific test piece molding (FIG. 1) having a length of 50 mm, a width of 10 mm and a thickness of 1 mm by the resin composition as described above, The light transmittance is 8% or less. As described above, since the transmittance at a wavelength of 700 nm is 10% or less, an effect of reducing appearance defects due to the inorganic filler upon cutting is exhibited. The light transmittance is more preferably 5% or less, and further preferably 3% or less.

[Lightness of molded article]

Further, in the inorganic filler-containing resin composition of the present invention, the lightness L * of the above-mentioned test piece compact is 50 to 90. When the value of L * is in this range, the decorative property of the molded article tends to be exhibited, and the effect of reducing the appearance defects of the present invention at the time of cutting is remarkable. Further, it is more preferable that the lightness L * is in the range of 60 to 80.

The light transmittance and the lightness L * of the molded article of the inorganic filler-containing resin composition of the present invention are adjusted based on the kind of the inorganic filler, the type of pigment, and the content of the inorganic filler contained in the resin composition. Hereinafter, components constituting the inorganic filler-containing resin composition will be described.

[Thermoplastic resin]

The thermoplastic resin is not particularly limited, and any thermoplastic resin which can be usually used can be appropriately selected.

For example, there may be mentioned polyolefins such as polyphenylene sulfide, polypropylene, polyethylene, polyethylene terephthalate, polyamide, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, , Polyoxymethylene, polybutylene terephthalate, polyether ether ketone, aromatic polyester or aromatic polyester amide-based liquid crystalline polymer. Among them, polybutylene terephthalate, polyphenylene sulfide, and liquid crystalline polymer are preferable in terms of impact resistance and rigidity.

The content of the thermoplastic resin in the inorganic filler-containing resin composition is not particularly limited, but is preferably 30 to 90% by mass, more preferably 40 to 80% by mass in order to balance impact resistance and stiffness with moldability , And more preferably 50 to 70 mass%.

[Inorganic filler]

As the inorganic filler, any of a fibrous filler, a non-fibrous filler (a granular filler, a plate filler and the like) may be used, and two or more kinds of these may be used in combination. According to the resin composition containing the inorganic filler, the impact resistance and rigidity of the molded article can be improved.

Of the various inorganic fillers described above, it is preferable to use a fibrous filler in view of being able to impart more excellent impact resistance and rigidity. Among these fibrous fillers, glass fibers are particularly preferable. As the glass fiber, it is preferable that all known materials are used, and it is preferable that the glass fiber has a glass fiber diameter, a shape such as a cylinder, a cocoon-shaped cross section, an elliptical cross section, or the like when used for the production of a strand, The method of the road or the glass cut is not particularly limited.

With regard to glass fibers, the kind of glass is not particularly limited, but E-glass or an anti-corrosive glass containing a zirconium element in its composition is preferably used in terms of quality. The fiber length and the fiber diameter of the glass fiber are not particularly limited and may be within a general range as described above. For example, those having a fiber length of 0.1 mm or more and 6.0 mm or less and a fiber diameter of 9.0 to 15.0 m . The average particle diameter of the non-fibrous filler is also not particularly limited and may be within a general range. For example, the average particle diameter may be 0.1 占 퐉 or more and 500 占 퐉 or less. Here, the fiber length of the fibrous filler, the average diameter of the fiber diameter, and the average diameter of the non-fibrous filler can be measured with a CCD camera (manufactured by Seishin Co., Ltd., dynamic image analysis method / particle ) Analyzer PITA-3), and can be calculated by a weighted average.

The content of the inorganic filler in the inorganic filler-containing resin composition is not particularly limited, but is preferably from 10 to 70% by mass, more preferably from 20 to 60% by mass from the viewpoint of giving better impact resistance and rigidity, More preferably from 30 to 50% by mass.

In addition, a fibrous filler and a non-fibrous filler may be used in combination, for example, from the viewpoint of significantly reducing warpage while imparting impact resistance to the formed article. In this case, a particularly preferable combination is a combination of glass fiber and glass flake. When the fibrous filler and the non-fibrous filler are used together, the total amount of the fibrous filler and the non-fibrous filler is preferably in the range of 50 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the thermoplastic resin. The ratio of the fibrous filler to the non-fibrous filler may be appropriately selected within a range not hindering the object of the present invention. From the viewpoint of the effect of reducing the warpage, the aspect ratio of the non-fibrous filler is preferably 1 or more and 10 or less.

[Pigment]

Examples of the pigment include a white pigment and a coloring pigment having a color. In the resin composition containing an inorganic filler of the present invention, in a molded product of a test piece having a length of 50 mm, a width of 10 mm and a thickness of 1 mm formed by using such a resin composition, the light transmittance at a wavelength of 700 nm in the thickness direction is 8% , And a pigment exhibiting a relatively low transmittance is used.

Specifically, at least one kind of white pigment selected from the group consisting of titanium oxide, zinc sulfide, magnesium oxide, and barium sulfate can be selected as the white pigment. Of these, titanium oxide, zinc sulfide or zinc oxide is preferable from the viewpoint of dielectric property (low dielectric loss tangent), zinc sulfide and zinc oxide are more preferable, and zinc sulfide is particularly preferable.

As the coloring pigment, any organic or inorganic coloring matter pigment necessary for designing can be appropriately selected. For example, in a color index (CI) (published by The Society of Dyers and Colourists), it is preferable to use a compound classified as a pigment, specifically a color index (CI) number .

The average particle diameter of the pigment is not particularly limited and may be suitably selected in consideration of various factors such as hiding properties, dielectric properties, and fluidity when mixed with a thermoplastic resin, and is preferably from 0.1 to 15 μm, more preferably from 1 to 10 μm Is particularly preferable. The average particle diameter of the pigment can be determined by measuring the particle diameter of the pigment particles by observation with an electron microscope and calculating the arithmetic average of the particle diameters of 1000 particles of the pigment before mixing with the thermoplastic resin.

The content of the pigment in the inorganic filler-containing resin composition may be appropriately adjusted so as not to deteriorate the impact resistance, and is preferably 0.4 to 12 mass%, more preferably 1.0 to 10 mass%, more preferably 1.5 to 5 mass% Is particularly preferable.

The white pigment and the coloring pigment can be used in combination from the viewpoints of dielectric properties and designability. In this case, the content ratio can be appropriately selected from the viewpoint of not deteriorating impact resistance.

[Other: Additives]

In the resin composition containing an inorganic filler of the present invention, commonly used additives such as a skid necessary for molding may be contained, if necessary. Examples of the additives include additives such as antioxidants, stabilizers, nucleating agents, plasticizers, lubricants, release agents, hydrolysis improvers, flow improvers, and flame retardants, organic fillers, metal fillers, and thermosetting resins.

«2. Molded article of inorganic filler-containing resin composition, method of producing molded article »

The inorganic filler-containing resin composition of the present invention can be produced as a single molded body or as a molded body compounded with metal parts.

Specifically, when the inorganic filler-containing resin composition is produced as a single molded article, the molding method is not particularly limited. For example, a molded article can be obtained by melt injection molding a mold. In addition, when the metal part and the resin composition are formed into a molded body by complex molding by injection molding, various methods such as insert molding, outsert molding, and hoop molding can be used. Here, in the case of forming a molded article by compositing with a metal part, the metal part may be surface-treated in advance in order to improve the adhesion with the metal part. The component to be compounded is not limited to metal, and inorganic solids such as ceramics and glass may be used.

Here, in the formed article of the inorganic filler-containing resin composition, cutting is performed by a conventional machine tool in order to finally adjust the formed article to a desired shape. For example, after the inorganic filler-containing resin composition is formed into a molded article by injection molding, a cutting process is performed to adjust the injection molded article to a desired shape. At this time, molding conditions of the injection molding, for example, Depending on the shape, filling temperature, and filling rate, the inorganic filler contained in the molded article may be oriented in a direction perpendicular to the cutting surface. When the inorganic filler is oriented by cutting the injection molded body as described above, a part (cross-section) of the inorganic filler is exposed on the surface of the molded body by cutting, and a part of the surface of the molded body is whitened May result in unintended design.

The present invention relates to an inorganic filler-containing resin composition which is a raw material of a molded article and which is prepared by adjusting the constituent components of the inorganic filler-containing resin composition so as to set the color of the molded article to a specific range and to reduce the light transmittance to a specific value or less. It can be suppressed.

As described above, since the inorganic filler-containing resin composition of the present invention has an effect of reducing occurrence of whitening or the like caused by the inorganic filler when the molded article is cut, the resin composition containing the inorganic filler , The occurrence of unintentional design is suppressed, and consequently, the occurrence of defective appearance is reduced.

The use of the inorganic filler-containing resin composition of the present invention is not particularly limited. For example, as described above, the impact resistance and rigidity of a case for an electric or electronic device such as a portable terminal or a PC are required, And is particularly useful as a raw material for a molded article constituting part or all of the members.

[ Example ]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

≪ Examples and Comparative Examples >

The inorganic filler-containing resin composition was injection-molded, and the injection-molded article was cut to produce a 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 inorganic filler-containing resin composition are as shown in the following description and tables.

≪ Inorganic filler-containing resin composition >

The following raw material components were dry blended and then charged into a twin screw extruder having a cylinder temperature of 260 占 폚 and melt kneaded to obtain an inorganic filler-containing resin composition pelletized. The blending amount (parts by mass) of each component is as shown in Table 1.

[Thermoplastic resin]

Polybutylene terephthalate (PBT): Juronex (registered trademark), manufactured by Wintec Polymer Co., Ltd. (IV = 0.75 dL / g)

[Inorganic filler]

Glass fiber (GF): ECS03T-747 (fiber length: 3 mm,? Strand with fiber diameter of 13 占 퐉), manufactured by Nippon Electric Glass Co.,

[Pigment]

Pigment (1): Sulfur sulfide pigment 1, manufactured by Japan Pigment Co.

Pigment (2): Sulfur sulfide pigment 2, manufactured by Nippon Pigment Co.

Pigment (3): a zinc oxide-based pigment, manufactured by Pigment Company of Japan

Pigment (4): Carbon black, "MA600B" manufactured by Mitsubishi Chemical Corporation

· Pigment (5): white pigments based on zinc oxide, manufactured by Japan Pigment Company

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

≪ Preparation of inorganic filler-containing resin composition molded article (strand-shaped test piece)

The obtained pellets of the inorganic filler-containing resin composition were injection-molded using a mold having a film gate having a width of 10 mm and a thickness of 1 mm at the longitudinal end portions of the cavity of 50 mm in length, 10 mm in width and 1 mm in thickness to obtain a test piece compact. Molding conditions are as follows.

(Molding conditions)

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

Cylinder temperature: 260 ° C

Mold temperature: 80 ℃

Injection speed: 70mm / s

Boom pressure: 80MPa × 5 seconds

2, the obtained molded body was cut so as to be divided into two in the longitudinal direction substantially along the center line in the width direction, and then the end face was polished in the following conditions to obtain a stranded phase having a length of 50 mm, a width of 5 mm and a thickness of 1 mm A test piece was prepared.

(Polishing condition)

Apparatus: "Ecomet 3" manufactured by Bullusha

Abrasive paper: Carbide # 240, # 400, # 600, UF800 and UF1200 manufactured by Buluta Co., Ltd. were used in this order.

≪ Evaluation of test piece &

The following evaluations were carried out on the molded body of the test piece and the strand-shaped test piece. Unless otherwise specified, the measurement was carried out in an atmosphere of 23 ° C and 50% RH.

[Measurement of light transmittance]

Using a spectrophotometer V-570 integrating sphere ISN-470 manufactured by Nippon Bunko K.K., the light transmittance of the plate surface (thickness direction) of the molded body of the test piece was measured at a wavelength of 700 nm.

[Color]

L * of the surface of the test piece molded article was measured using a color difference meter SE6000 manufactured by Nippon Denshoku Kogyo Co.,

[Exterior]

The cross-section of the polished strand-like test piece was visually observed. 10 samples were made in the same manner, and when the unintended design was felt in any one of the samples, the sample was rated as x, and the case where the sample was not felt was rated as?.

[Strength (Impact resistance)]

The pelletized resin composition thus prepared was subjected to injection molding at a cylinder temperature of 260 캜 and a mold temperature of 80 캜 at a mold temperature of 80 캜 and subjected to evaluation under the conditions of 23 캜 in accordance with the evaluation standard prescribed in ISO179 / / m ² or more ○ a, a a 5kJ / m ² or more and less than 7kJ / m ² △, under 5kJ / m ² was La ×.

As apparent from the above results, in the present invention, both strength and designability can be achieved.

Claims (6)

As a resin composition containing an inorganic filler,
At least a thermoplastic resin, an inorganic filler, and a pigment,
And a lightness transmittance at a wavelength of 700 nm in the thickness direction of the molded article is 8% or less and a lightness L * is 50 to 90 when the molded body of the test piece having a length of 50 mm, a width of 10 mm and a thickness of 1 mm is molded by the resin composition,
Resin composition containing an inorganic filler. The method according to claim 1,
Wherein the pigment is a zinc sulfide pigment. The method according to claim 1,
Wherein the inorganic filler is a glass fiber. A molded article obtained by molding the inorganic filler-containing resin composition according to any one of claims 1 to 3,
Wherein a part of the inorganic filler is exposed on the surface of the molded article. 5. The method of claim 4,
Wherein a part of the inorganic filler exposed on the surface of the molded article is a cross section of the inorganic filler. A method for producing a molded article of an inorganic filler-containing resin composition according to claim 4,
A step of injection-molding the inorganic filler-containing resin composition to obtain an injection-molded article,
And cutting the injection-molded body,
A method for producing a molded article of an inorganic filler-containing resin composition.

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