JP2012131033A - Two-color molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-color molding exhibiting deep rainbow color gloss which is not conventionally attained, and having an extremely excellent hue, appearance abundant in stereoscopic effect, extremely excellent designability and abundant high quality feeling.SOLUTION: (1) A thermoplastic resin material constituting an outer ward of the two-color molding comprises a polycarbonate resin composition containing 100 pts.wt. of a polycarbonate resin (A), 0.01-0.2 pt.wt. of a phosphate type antioxidant (B) and 0.1-10 pts.wt. of a pulverized artificial opal (C) as essential ingredients, and (2) the thermoplastic resin material constituting the inner ward of the two-color molding comprises a transparent synthetic resin (D) or an opaque synthetic resin (E). The two-color molding is obtained by molding two kinds of the thermoplastic resin materials using a two-color molding injection molding machine.

Description

   The present invention relates to a two-color molded article having excellent design properties and thermal stability. More specifically, the present invention relates to a two-color molded article comprising an inner part made of a transparent synthetic resin and an outer part made of a polycarbonate resin composition containing pulverized artificial opal and a phosphorus antioxidant as essential components.

  From the viewpoint of design, materials having excellent design and appearance are required for members such as mobile phones, portable game machines, vehicles, home appliances, personal computers, office supplies, and other miscellaneous housings.

  As means for satisfying the above-mentioned demand, in the prior art, a method of applying a metallic paint on the surface of a polycarbonate resin molded article, aluminum fine powder, glass flake coated with a metal film or mica and titanium dioxide is used. A method of blending a multilayered pigment or the like with the resin and melt-molding them has been adopted. However, although these methods can achieve a certain level of design and appearance, they cannot be obtained with a deep rainbow luster and full of three-dimensional appearance, and the need for improvement has been advocated. .

Japanese Patent No. 2651058 Special table 2003-525319 gazette

  On the other hand, in addition to the above-described improvement in design and appearance, a two-color molding technique is employed in order to give a higher-class feeling. As a thermoplastic resin used for two-color molding, a polycarbonate resin is widely used in the above applications because it is excellent in impact resistance, heat resistance, thermal stability and the like in addition to transparency. However, a two-color molded product having a deep rainbow luster, a three-dimensional appearance, and a high-class feeling has not yet been obtained.

  The present invention provides a two-color molded article that exhibits a deep rainbow luster that has not been obtained in the past, has a very good hue, has a three-dimensional appearance, is extremely excellent in design, and is rich in luxury. The purpose is to provide.

  As a result of diligent research to achieve the above object, the present inventor uses a composition comprising a polycarbonate resin containing ground artificial opal and a specific antioxidant as essential components in the outer portion of a two-color molded product. Thus, the inventors have found that the object can be achieved, and have completed the present invention.

That is, the first aspect of the present invention is a two-color molded product formed by molding two types of thermoplastic resin materials using a two-color molding injection molding machine,
(1) The thermoplastic resin material constituting the outer portion of the two-color molded product is polycarbonate resin (A) 100 parts by weight, phosphorous antioxidant (B) 0.01-0.2 parts by weight, and pulverized artificial opal. (C) It consists of a polycarbonate resin composition containing 0.1 to 10 parts by weight as an essential component, and (2) a thermoplastic resin material constituting the inner part of the two-color molded product is a transparent synthetic resin ( D),
A two-color molded product characterized by the above is provided.

Moreover, the second aspect of the present invention is a two-color molded product obtained by molding two types of thermoplastic resin materials using a two-color molding injection molding machine,
(1) The thermoplastic resin material constituting the outer portion of the two-color molded product is polycarbonate resin (A) 100 parts by weight, phosphorous antioxidant (B) 0.01-0.2 parts by weight, and pulverized artificial opal. (C) It consists of a polycarbonate resin composition containing 0.1 to 10 parts by weight as an essential component, and (2) a thermoplastic resin material constituting the inner part of the two-color molded product is an opaque synthetic resin ( E)
A two-color molded product characterized by the above is provided.

  The two-color molded product of the present invention has a deep iridescent luster, has a very good hue, and has a three-dimensional appearance, is extremely excellent in design, and rich in luxury. For example, it is suitably used for members such as mobile phones, portable game machines, vehicles, home appliances, personal computers, office supplies, and other miscellaneous goods.

  The polycarbonate resin (A) used in the present invention is a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method obtained by reacting a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate. A typical example is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Sulfone, and the like.

These can be used alone or in admixture of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin in the inner portion of the two-color molded product is usually 10,000 to 100,000, preferably 16000 to 22,000, and more preferably 14,000 to 21,000. The viscosity average molecular weight of the polycarbonate resin in the outer portion of the two-color molded product is usually 10,000 to 100,000, preferably 16,000 to 25,000, and more preferably 17,000 to 24,000. In producing such an aromatic polycarbonate resin, a molecular weight regulator, a catalyst, and the like can be used as necessary.

As phosphorus antioxidant (B) used by this invention, well-known phosphorus antioxidant used for polycarbonate resin, for example, Sandstub P-EPQ by Clariant Japan, Sumitizer by Sumitomo Chemical Co., Ltd. P-168 etc. are mentioned. Especially, the compound shown in the following general formula 1 can be used conveniently.
General formula 1:

（一般式１において、Ｒ１、Ｒ２は炭素数１〜２０のアルキル基、またはアルキル基で置換されてもよいアリール基を、ａ、ｂは整数０〜３を示す。）

(In General Formula 1, R1 and R2 represent an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and a and b represent integers 0 to 3.)

  Examples of the compound of the general formula 1 include Adeka Stab PEP-36 manufactured by Adeka Corporation as a commercially available one.

  The compounding quantity of phosphorus antioxidant (B) is 0.01-0.2 weight part per 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.01 parts by weight, the heat stability is poor, and if it exceeds 0.2 parts by weight, the hue is inferior. More preferably, it is 0.03-0.15 weight part, More preferably, it is 0.05-0.10 weight part.

  The pulverized artificial opal (C) used in the present invention is obtained by pulverizing a plate-like opal composed of fine silicon dioxide particles. In this production method, fine particles of silicon dioxide are uniformly precipitated in a liquid such as water to form a state in which the particles are closely arranged, and then the water is slowly removed by removing the water from the precipitated layer. Examples of the method include forming an opal layer and pulverizing the same. The pulverized artificial opal (C) is commercially available, for example, as Kyoto Opal manufactured by Kyocera Corporation.

  The blending amount of the pulverized artificial opal (C) is 0.1 to 10 parts by weight per 100 parts by weight of the polycarbonate resin (A). A blending amount of less than 0.1 part by weight is not preferable because a high-quality appearance cannot be obtained. Moreover, since the impact strength will fall remarkably when the compounding quantity exceeds 10 weight part, it is unpreferable. More preferably, it is in the range of 2 to 10 parts by weight.

  As an average particle diameter of the pulverized artificial opal (C), those having a size of 50 to 3000 μm can be suitably used. When the average particle diameter is less than 50 μm, the brightness of the obtained molded product may be inferior. On the other hand, if it exceeds 3000 μm, the resulting molded product may be inferior in quality. A more preferable average particle diameter is 250 to 2000 μm.

  As a blending method of the polycarbonate resin composition used for the outer portion of the two-color molded product of the present invention, the pulverized artificial opal (C) may be further pulverized during mixing and melt-kneading. Mixing under mild conditions using a tumbler and melt kneading with a full flight screw is desirable. Moreover, there is no restriction | limiting also about the compounding order of polycarbonate resin (A), phosphorus antioxidant (B), and a grinding | pulverization artificial opal (C), and addition frequency (for example, batch addition, divided addition, etc.).

  Furthermore, various resins, heat stabilizers, fluorescent brighteners, pigments, dyes, carbon black, fillers, mold release agents, ultraviolet absorbers, in the above polycarbonate resin composition, as long as the effects of the present invention are not impaired. Additives such as antistatic agents, rubber, softeners, spreading agents (liquid paraffin, epoxy soybean oil, etc.), flame retardants, organic metal salts, etc., polytetrafluoroethylene resin for flame retardant dripping prevention good.

  Examples of the transparent synthetic resin (D) used as the inner portion of the two-color molded product of the present invention include polymethyl methacrylate, polycarbonate, polystyrene, alicyclic polyolefin, amorphous polyester, and amorphous fluorine resin. It is done. Among these, from the viewpoint of transparency, polycarbonate resins, acrylic resins such as polymethylmethacrylate, and polystyrene resins are preferable. From the viewpoint of ease of recycling, it is more preferable to use a polycarbonate resin that is the same type as the surface layer. The degree of transparency of the transparent synthetic resin is such that the observer can recognize the object when light is transmitted and the molded article of the synthetic resin is interposed between the observer and an object such as a light source. It refers to performance.

  On the other hand, the transparent synthetic resin may be colored while maintaining transparency. When the colored transparent synthetic resin is used as a base material, the effect that the brightness of the pulverized artificial opal (C) is more conspicuous is exhibited, and a two-color molded product having further excellent design properties can be obtained.

  Examples of the opaque synthetic resin (E) used as the inner portion of the two-color molded product of the present invention include styrene resins such as ABS resin. A PC / ABS alloy mixed with a polycarbonate resin can also be suitably used.

As a method for producing a two-color molded article of the present invention, a known method using an injection molding machine for two-color molding can be mentioned, and in particular, a method comprising the following three steps can be preferably used.
First step: A step of injecting the outer portion of the two-color molded product into the cavity of the primary molding die in a closed state, and molding the outer portion.
Second step: Next, a step of opening the primary molding die, taking out the molded outer portion, and disposing the molded outer portion in the cavity of the secondary molding die in an opened state.
Third step: Next, the step of closing the secondary molding die, injecting the inner portion of the two-color molded product into the cavity of the secondary molding die, and molding the inner portion.

  The thickness of the molded product of the outer shell part and the inner shell part is not particularly limited, but considering the rigidity of the obtained two-color molded product and the display of a high-class feeling, the thickness of the inner shell part is 0.8. -3.0 mm, and the outer portion is preferably 0.8-3.0 mm, more preferably 1.0-2.0 mm as the inner portion and 1.0-2.0 mm as the outer portion.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. “Parts” in the examples are based on weight unless otherwise specified.

Details of the raw materials used are as follows.
Polycarbonate resin (A):
Polycarbonate resin synthesized from bisphenol A and phosgene (Sumitomo Dow Caliber 301-22, viscosity average molecular weight 19000)
(Hereinafter abbreviated as “PC-1”)
Phosphorous antioxidant (B):
ADEKA ADK STAB PEP-36
(Hereafter abbreviated as “AO”)
Ground artificial opal (C):
Kyoto Opal manufactured by Kyocera (white opal powder (blue))
(Particle diameter 350-500 μm, hereinafter abbreviated as “OP”)
Transparent synthetic resin (D):
Polycarbonate resin synthesized from bisphenol A and phosgene (Sumitomo Dow Caliber 301-22, viscosity average molecular weight 19000)
(Hereinafter abbreviated as “PC-1”)
Colored polycarbonate resin containing 0.3% of Sumiplast Black HB as a colorant in the PC-1 (hereinafter abbreviated as “PC-2”)
Opaque synthetic resin (E):
PC / ABS alloy mixed with ABS resin and polycarbonate resin (PC / ABS alloy manufactured by Sumitomo Dow Co., Ltd.) Colored PC / ABS alloy containing 0.3% of Mitsubishi Carbon Black 1000B as a colorant, hereinafter referred to as “PC / Abbreviated as “ABS”)

(Preparation of pellets of polycarbonate resin composition constituting the outer shell)
The above-mentioned various raw materials are hand blended at the blending ratios shown in Tables 1 and 2, and melt-kneaded at a melting temperature of 270 ° C. using a single-screw extruder (VS-40 manufactured by Tanabe Plastics Co., Ltd.). Various pellets of the resin composition were obtained.

(Creation of two-color molded products)
Examples 1-4 and Comparative Examples 1-4:
After drying the obtained various pellets at 120 ° C. for 4 hours, the resulting pellets were dried at a melting temperature of 280 ° C. with a two-color injection molding machine (DC200 manufactured by Nippon Steel Co., Ltd.) with a thickness of 1.0 mm. A two-color molded product (size: 60 × 60 × 3 mm) having an inner shell thickness of 2.0 mm was prepared.
Example 5 and Comparative Example 5:
The outer portion is obtained by drying the obtained polycarbonate resin pellets at 120 ° C. for 4 hours, and then using a two-color injection molding machine (DC200 manufactured by Nippon Steel Co., Ltd.) to obtain a thickness of 1 under the condition of a melting temperature of 280 ° C. 0.0 mm outer part was created. The inner part is a two-color molded product (size: 60 × 60 × 3 mm) in which the thickness of the inner part is 2.0 mm under conditions of a melting temperature of 250 ° C. after drying PC / ABS at 110 ° C. for 4 hours It was created.

(Evaluation items and evaluation methods)
Appearance:
Using the obtained two-color molded product, the appearance was visually determined based on the presence or absence of luxury. The criteria for a high-quality feeling are as follows.
luxury:
・ If the crushed artificial opal (A) has a variety of sparkles from the surface side, and there is no dullness on the surface of the laminate: Has a high-class feeling. Or when the surface layer of the two-color molded product has dullness: Tables 1 and 2 show the results without high-quality feeling.

As shown in Examples 1 to 5, those satisfying the constituent requirements of the present invention satisfied the required performance.
On the other hand, when the blending amount of the pulverized artificial opal is less than the prescribed amount (Comparative Example 1, Comparative Example 3 and Comparative Example 5) and when it is large (Comparative Example 4), and the blending amount of the phosphorus AO is less than the prescribed amount. In all cases (Comparative Example 2), the high-quality feeling of the two-color molded product was inferior.

Claims (8)

A two-color molded product obtained by molding two types of thermoplastic resin materials using a two-color molding injection molding machine,
(1) The thermoplastic resin material constituting the outer portion of the two-color molded product is polycarbonate resin (A) 100 parts by weight, phosphorous antioxidant (B) 0.01-0.2 parts by weight, and pulverized artificial opal. (C) It consists of a polycarbonate resin composition containing 0.1 to 10 parts by weight as an essential component, and (2) a thermoplastic resin material constituting the inner part of the two-color molded product is a transparent synthetic resin ( D),
Two-color molded product characterized by that. A two-color molded product obtained by molding two types of thermoplastic resin materials using a two-color molding injection molding machine,
(1) The thermoplastic resin material constituting the outer portion of the two-color molded product is polycarbonate resin (A) 100 parts by weight, phosphorous antioxidant (B) 0.01-0.2 parts by weight, and pulverized artificial opal. (C) It consists of a polycarbonate resin composition containing 0.1 to 10 parts by weight as an essential component, and (2) a thermoplastic resin material constituting the inner part of the two-color molded product is an opaque synthetic resin ( E)
Two-color molded product characterized by that. The two-color molded article according to claim 1 or 2, wherein the phosphorous antioxidant (B) is a compound represented by the following formula (1).
General formula 1

(In General Formula 1, R1 and R2 represent an alkyl group having 1 to 20 carbon atoms or an aryl group which may be substituted with an alkyl group, and a and b represent integers 0 to 3.)   The bicolor according to claim 1 or 2, wherein the amount of the phosphorous antioxidant (B) is 0.03 to 0.15 parts by weight per 100 parts by weight of the polycarbonate resin (A). Molding.   The two-color molded article according to claim 1 or 2, wherein the pulverized artificial opal (C) has an average particle size of 50 to 3000 µm.   The two-color molded article according to claim 1 or 2, wherein the blending amount of the pulverized artificial opal (C) is 2 to 10 parts by weight per 100 parts by weight of the polycarbonate resin (A).   The two-color molded article according to claim 1, wherein the transparent synthetic resin (D) is a polycarbonate resin or a colored transparent polycarbonate resin.   The two-color molded article according to claim 2, wherein the opaque synthetic resin (E) is a PC / ABS alloy or a colored PC / ABS alloy made of a polycarbonate resin and an ABS resin.