JP2011111589A - Polycarbonate resin composition excellent in jet-blackness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin composition which has overcome disadvantages of reduction in jet-blackness and whitening, has excellent jet-blackness (piano-black appearance), and is excellent in drop impact resistance, scratch resistance, and release properties. <P>SOLUTION: The polycarbonate resin composition excellent in jet-blackness includes 100 pts.wt. of a polycarbonate resin (A), 0.05-1.0 pt.wt. of an organic black dye (B) and 1-8 pts.wt. of a cyclic poly(alkylene terephthalate) oligomer (C) as essential ingredients, wherein the optical property of the organic black dye (B) is that it has a specific light transmittance. A molded article obtained by molding the polycarbonate resin composition maintains the performance such as excellent impact strength, heat resistance, and thermal stability which a polycarbonate resin originally has, and has a beautiful, deep, and quality piano-black appearance. The polycarbonate resin composition is excellent in the productivity of a thin-wall molded article since it is excellent in fluidity, and it is suitable for applications such as a personal digital assistance, a game machine, a personal computer, and a household electrical appliance since it is excellent also in the impact resistance at the time of dropping a product. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin composition that is excellent in jet blackness and excellent in drop impact property, scratch resistance, and releasability. More specifically, the present invention relates to a polycarbonate resin composition having excellent jet blackness, drop impact resistance, scratch resistance, and releasability while maintaining the impact resistance, heat resistance, thermal stability, and the like that are characteristics of the polycarbonate resin. Moreover, the molded product obtained from the polycarbonate resin composition of the present invention has a beautiful, heavy and high-quality appearance.

  Polycarbonate resin is a thermoplastic resin excellent in impact resistance, heat resistance, thermal stability, and the like, and is widely used in fields such as electricity, electronics, ITE, machinery, and automobiles. On the other hand, in each of the aforementioned fields, while taking advantage of these excellent performances of the resin, it has an excellent jetness (also called piano black) from the viewpoint of design and design of the obtained molded product. May have been desired.

  As a technique for imparting jet blackness to a polycarbonate resin composition, a technique for adding carbon black having high concealment (Patent Document 1), a technique for adding silicone oil (Patent Document 2), and the like have been proposed. However, when a carbon black pigment is added, it is difficult to develop high jetness although the concealability is improved. On the other hand, the addition of silicone oil has a problem of whitening during molding.

JP2003-96286 JP 2004-210889 A

  On the other hand, although polycarbonate resin is a resin with excellent impact resistance, there are many thin molded products in applications that require lighter, thinner and smaller products in recent years, such as mobile phones and game machines, etc. In addition to these problems, there is a particular demand for improvement in mold release during molding and scratchability on the surface of the molded product.

  The object of the present invention is to overcome the above-mentioned problems in the prior art, that is, to overcome the disadvantages of jet black deterioration and whitening when using carbon black or silicone oil, An object of the present invention is to provide a polycarbonate resin composition having a piano black-like appearance) and having excellent drop impact, scratching and releasability.

  As a result of intensive studies in view of such an object, the present inventors have found that an organic black dye and a cyclic poly (alkylene terephthalate) oligomer having specific optical performance in a polycarbonate resin having transparency, and, if necessary, a rubber component, It was found that a piano black-like appearance can be obtained without impairing the jetness of the obtained molded product, and the impact resistance at the time of dropping can be improved, thereby completing the present invention.

That is, in the present invention, 100 parts by weight of the polycarbonate resin (A), 0.05 to 1.0 parts by weight of the organic black dye (B) and 1 to 8 parts by weight of the cyclic poly (alkylene terephthalate) oligomer (C) are essential components. A resin composition containing as
The optical characteristics of the organic black dye (B) are 2 mm thick obtained by injection molding a resin composition comprising 100 parts by weight of the polycarbonate resin (A) and 0.3 parts by weight of the organic black dye (B). When the light transmittance of the flat plate is measured, it has a light transmittance of 50% or more in a wavelength range of 800 to 900 nm.
The present invention provides a polycarbonate resin composition having excellent jetness characteristics.
Another aspect of the present invention is obtained by further blending 1 to 8 parts by weight of the rubber component (D) (per 100 parts by weight of the polycarbonate resin (A)) with the polycarbonate resin composition having excellent jetness. A polycarbonate resin composition is provided.

  The molded product obtained by molding the polycarbonate resin composition of the present invention is a beautiful, heavy, high-quality piano black while maintaining the excellent impact strength, heat resistance, thermal stability, etc. inherent to the polycarbonate resin. Because of its excellent appearance and fluidity, it has excellent productivity for thin-walled molded products, and it also has excellent impact resistance when dropped, so it can be used for personal digital assistants, game consoles, personal computers, and home appliances. It is suitable for such applications.

  The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example of the polymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (commonly referred to as 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 may be used alone or in combination of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4′-dihydroxydiphenyl, and the like may be used in combination.

  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 (A) is not particularly limited, but is usually in the range of 10,000 to 100,000, more preferably 14,000 to 30,000, and even more preferably 16,000 to 26,000 in terms of moldability and strength. Moreover, when manufacturing this polycarbonate resin (A), a molecular weight regulator, a catalyst, etc. can be used as needed.

The above viscosity average molecular weight is 0.5 wt% polycarbonate resin solution using methylene chloride as a solvent, and the specific viscosity (η _sp ) is measured at a temperature of 20 ° C. using a Cannon-Fenske type viscosity tube. [Η] was obtained and calculated from the following SCHNELL equation.
[Η] = 1.23 × 10 ⁻⁴ M ^0.83

  Examples of the organic black dye (B) used in the present invention include a mixture of organic dyes such as anthraquinone, perinone, perylene, azo, methine, and xylinone. In particular, anthraquinone-based and perinone-based organic dyes are preferably used. Anthraquinone-based organic dyes such as blue, purple and green are preferable, and perinone-based organic dyes such as red and orange are preferable.

  The organic black dye (B) of the present invention is obtained by injection molding a resin composition comprising 100 parts by weight of a polycarbonate resin (A) and 0.3 part by weight of an organic black dye (B) as its optical characteristics. When measuring the light transmittance of a flat plate having a thickness of 2 mm, it is necessary to have a light transmittance of 50% or more in a wavelength region of 800 to 900 nm. The light transmittance is measured according to ASTM D-1003.

  When the light transmittance is less than 50%, an excellent jet black (piano black-like) appearance cannot be obtained, which is not preferable. The light transmittance is preferably 80% or more, more preferably 85% or more.

  Moreover, as a compounding quantity of organic type black dye (B), it is 0.05-1.0 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.05 parts by weight, the jet blackness and the hiding property are inferior, and if it exceeds 1.0 parts by weight, the thermal stability of the polycarbonate resin (A) is inferior, and further, the amount of gas generated during molding is large. This is not preferable. A more preferable blending amount is in the range of 0.1 to 0.5 parts by weight, and more preferably 0.2 to 0.3 parts by weight.

The cyclic poly (alkylene terephthalate) oligomer (C) used in the present invention is one having a structural unit represented by the following general formula.

  In the formula, R represents an alkylene group having 2 to 8 carbon atoms, and Ar represents a divalent aromatic group. In particular, those in which R is ethylene or tetramethylene and Ar is m-phenylene or p-phenylene are preferably used.

  The cyclic poly (alkylene terephthalate) oligomer (C) is usually a mixture of cyclic oligomers having a polymerization degree of 2 to 30 and the main component having a polymerization degree of up to 12. Commercially available products include CBT manufactured by Cyclix Corporation.

  The compounding quantity of cyclic poly (alkylene terephthalate) oligomer (C) is 1-8 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 1 part by weight, the effect of improving scratch resistance is small, and if it exceeds 8 parts by weight, the impact strength decreases and the appearance of the molded product also decreases, which is not preferable. More preferably, it is in the range of 2 to 5 parts by weight.

  The rubber component (D) used in the present invention includes acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), high impact polystyrene (HIPS) and the like. And rubber reinforced styrene copolymers, acrylic or silicone elastomers, and the like.

  The compounding quantity of a rubber component (D) is 1-8 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 1 part by weight, the drop impact strength is small, and if it exceeds 8 parts by weight, jet blackness is lowered, which is not preferable. More preferably, it is in the range of 2 to 5 parts by weight.

  The blending method of the various blending components (A), (B) and (C) of the present invention, and (D) depending on necessity is not particularly limited, and these can be carried out using any mixer such as a tumbler, ribbon blender, high-speed mixer, etc. And then kneading and kneading with a normal single-screw or twin-screw extruder. Moreover, there is no restriction | limiting in particular also about employ | adopting batch mixing and division | segmentation mixing for these compounding components.

  In addition, other known additives such as mold release agents, UV absorbers, antistatic agents, antioxidants, phosphorous heat stabilizers, spreading agents (epoxy soybean oil, liquid paraffin, etc.) may be used at the time of mixing. ) And the like.

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

The details of the used blending components are as follows.
Polycarbonate resin:
Polycarbonate resin synthesized from bisphenol A and phosgene (Sumitomo Dow Caliber 200-13 (viscosity average molecular weight: 21000),
(Hereinafter abbreviated as PC)
Organic black dye:
Sumiplast Black HB
(Manufactured by Sumika Chemtex Co., Ltd., hereinafter abbreviated as Colorant 1)
Light transmittance in a wavelength range of 800 to 900 nm: 85%
Sumiplast Black HLG
(Manufactured by Sumika Chemtex Co., Ltd., hereinafter abbreviated as Colorant 2)
Light transmittance in the wavelength region of 800 to 900 nm: 55%
Carbon black:
Furnace type carbon black (XC-305 manufactured by Cabot, hereinafter abbreviated as Colorant 3)
Light transmittance in a wavelength region of 800 to 900 nm: Less than 1% cyclic poly (alkylene terephthalate) oligomer:
Cyclic poly (butylene terephthalate) oligomer (CBT manufactured by Axia Materials, hereinafter abbreviated as CBT)
Rubber component:
Acrylonitrile-butadiene-styrene copolymer (ABS resin)
(Nippon A & L Co., Ltd. Clarastic S3710, hereinafter abbreviated as ABS)

(Preparation of polycarbonate resin composition pellets)
The above-mentioned various blending components are collectively put into a tumbler at the blending ratios shown in Tables 1 to 3, and after dry mixing for 10 minutes, using a twin screw extruder (KTX37 manufactured by Kobe Steel), a melting temperature of 280 ° C. Kneaded to obtain various pellets of the polycarbonate resin composition.

(Creation of test pieces for evaluation of jetness, optical properties, scratch resistance and impact strength)
The obtained pellets of various resin compositions were dried at 120 ° C. for 4 hours, and then jet jet under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 100 ° C. using an injection molding machine (J100E-C5 manufactured by Nippon Steel Works). A flat plate (90 × 50 × 2 mm) was used for evaluation of optical properties and scratches, and an ASTM Izod impact test piece (3.2 mm thickness) was used for evaluation of impact strength.

(Creation of test specimen for drop test evaluation)
The obtained pellets of various resin compositions were dried at 120 ° C. for 4 hours, and then in a box shape under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 120 ° C. using an injection molding machine (J100E-C5 manufactured by Nippon Steel Works). A molded product (150 × 30 × 20 mm, main wall thickness 2 mm) was prepared.

(Evaluation of jetness)
The evaluation of jetness is performed by irradiating the obtained 2 mm flat plate with the light of the LED light source (GETROS GTR-32T, brightness of 26.6 lumens) (the distance between the light of the flat plate and the LED light source is 10 cm) and visually. The degree of jetness was evaluated. The results are shown in Tables 1-3.
The evaluation criteria are as follows:
Good (◎): Even when illuminated by an LED light source, it glows black.
Good (◯): Even if the LED light source is irradiated, it glows black, but looks slightly whitish.
Defect (x): When an LED light source is irradiated, it glows whitish.

(Evaluation of optical properties)
The optical characteristics were evaluated by measuring the light transmittance at wavelengths of 800 nm and 900 nm with an ultraviolet-visible spectrophotometer (V-570 manufactured by JASCO Corporation) on the obtained 2 mm flat plate in accordance with ASTM D-1003. . A light transmittance of 50% or more was accepted at any wavelength. The results are shown in Tables 1-3.

(Evaluation of impact strength)
The impact strength was determined by measuring the notched Izod impact strength (J / m) under the condition of 23 ° C. using the obtained Izod impact test piece in accordance with ASTM D-256. 500 J / m or more was regarded as acceptable. The results are shown in Tables 1-3.

(Evaluation of drop strength)
The drop strength is the extent of damage by attaching a weight to the inside of the box so that the total weight is 1 kg, and dropping it onto a lauan material with a thickness of 75 cm to a thickness of 14 mm. It was evaluated by observing. Specifically, it is allowed to drop naturally so that the first 6 faces of the molded product, then 3 sides from the predetermined corner, and finally 1 corner (1 side, 3 sides, 6 faces) of the corner corresponds to the raw material. A total of 10 drop tests were taken as one cycle.
A crack that occurred on the surface of the molded product or a crack that resulted in a fractured surface was rejected. A deformation that retained the shape of the box was accepted, and three cycles or more were accepted. The results are shown in Tables 1-3.

(Evaluation of mold release resistance)
The obtained pellets of various resin compositions were dried at 120 ° C. for 4 hours. Next, using an injection molding machine (J100E-C5 manufactured by Nippon Steel Works) with a die equipped with a force sensor (force link 9351B) manufactured by Kistler on the ejector rod part, the dried pellets were subjected to cylinder temperature. A cylindrical shaped product (diameter 50 mm × length 50 mm × thickness 4 mm) was molded under the conditions of 280 ° C. and mold temperature 50 ° C. The force (mold release force) applied at the time of taking out the molded product was measured, and 100 kg or less was accepted.

(Evaluation of scratchability)
The evaluation of scratchability was performed as follows.
(1) One commercially available tissue paper is spread and folded five times, and a total of 32 laminates are prepared in advance.
(2) Prepare a jig (stainless steel, height 15 mm x width 15 mm x depth 10 mm, R3 mm saddle) with a linear pressure part of 15 mm, and wind the laminated tissue paper around the jig Put on.
(3) The jig around which the tissue paper obtained in the above (2) was wound was brought into contact with the surface of a flat plate (90 × 50 × 2 mm) for evaluation of scratchability, and a total of 250 g of the tissue was placed on the tissue. After adjusting to become a load, it is reciprocated 50 times at a speed of 50 mm / sec.
(4) Thereafter, the presence or absence of scratches generated on the surface of the flat plate was visually observed and evaluated according to the following criteria.
Good (◎): Good without any scratches.
Good (O): Although there are some scratches, it is not whitened.
Defect (x): The surface is whitened and looks whitish. Or the surface is scratched.
(5) The surface was not whitened or scratched.

  When the polycarbonate resin composition satisfied all the constituent requirements of the present invention (Examples 1 to 7), good results were exhibited over all the evaluation items.

On the other hand, in the case where the polycarbonate resin composition does not satisfy the constituent requirements of the present invention, each case has some drawbacks.
Comparative Example 1 was inferior in jet blackness because the blending amount of the organic black dye was less than the specified amount.
In Comparative Example 2, since the blending amount of the organic black dye was larger than the specified amount, the impact strength and the drop strength were reduced.
Since the comparative example 3 used carbon black for the coloring agent, it was inferior in jetness and light transmittance.
Comparative Example 4 was inferior in mold release resistance and scratch resistance because the amount of CBT was less than the specified amount.
Comparative Example 5 was inferior in impact strength and drop strength because the blending amount of CBT was larger than specified.
Comparative Example 6 was inferior in jet blackness, light transmittance, impact strength, drop strength, and scratch resistance because the amount of ABS added was larger than specified.

Claims (8)

Resin composition containing 100 parts by weight of polycarbonate resin (A), 0.05 to 1.0 part by weight of organic black dye (B) and 1 to 8 parts by weight of cyclic poly (alkylene terephthalate) oligomer (C) as essential components Because
The optical characteristics of the organic black dye (B) are 2 mm thick obtained by injection molding a resin composition comprising 100 parts by weight of the polycarbonate resin (A) and 0.3 parts by weight of the organic black dye (B). When the light transmittance of the flat plate is measured, it has a light transmittance of 50% or more in a wavelength range of 800 to 900 nm.
A polycarbonate resin composition having excellent jetness characteristics.   2. The polycarbonate resin excellent in jetness according to claim 1, wherein the compounding amount of the organic black dye (B) is 0.1 to 0.5 parts by weight per 100 parts by weight of the polycarbonate resin (A). Composition.   2. The polycarbonate resin excellent in jetness according to claim 1, wherein the compounding amount of the organic black dye (B) is 0.2 to 0.3 parts by weight per 100 parts by weight of the polycarbonate resin (A). Composition.   The optical characteristics of the organic black dye (B) are 2 mm thick obtained by injection molding a resin composition comprising 100 parts by weight of the polycarbonate resin (A) and 0.3 parts by weight of the organic black dye (B). 2. The polycarbonate resin composition having excellent jetness according to claim 1, which has a light transmittance of 80% or more in a wavelength region of 800 to 900 nm when the light transmittance of a flat plate is measured.   The optical characteristics of the organic black dye (B) are 2 mm thick obtained by injection molding a resin composition comprising 100 parts by weight of the polycarbonate resin (A) and 0.3 parts by weight of the organic black dye (B). 2. The polycarbonate resin composition having excellent jetness according to claim 1, which has a light transmittance of 85% or more in a wavelength region of 800 to 900 nm when the light transmittance of a flat plate is measured.   The polycarbonate resin composition excellent in jetness according to any one of claims 1 to 5, wherein the cyclic poly (alkylene terephthalate) oligomer (C) is a cyclic poly (butylene terephthalate) oligomer.   Furthermore, the rubber component (D) 1-8 weight part (per 100 weight part of polycarbonate resin (A)) is mix | blended, The polycarbonate excellent in jetness as described in any one of Claims 1-6 characterized by the above-mentioned. Resin composition.   The polycarbonate resin composition having excellent jetness according to claim 7, wherein the rubber component (D) is acrylonitrile-butadiene-styrene resin.