KR20070058085A - Polycarbonate resin composition with low gloss - Google Patents

Abstract

Provided is a polycarbonate resin composition, which shows a significant mattifying effect while not adversely affecting mechanical strength, heat resistance and impact strength. The polycarbonate resin composition comprises: (A) 100 parts by weight of a polycarbonate resin; (B) 5-15 parts by weight of an impact reinforcing agent comprising silicone-acrylic rubber as a core and polymethyl methacrylate as a shell; and (C) 0.5-10 parts by weight of a terpolymer comprising ethylene, methyl acrylate and glycidyl methacrylate represented by a formula 1 as monomers. The polycarbonate resin optionally further comprises amide-based wax.

Description

Polycarbonate resin composition with low gloss

The present invention relates to a low-gloss polycarbonate (hereinafter referred to as a PC) resin composition, and more specifically, (A) 100 parts by weight of a polycarbonate resin; (B) 5 to 15 parts by weight of an impact modifier containing silicone-acrylic rubber as the core component and polymethylmethacrylate as the shell component; And (C) a polycarbonate resin composition comprising 0.5 to 10 parts by weight of a terpolymer containing ethylene, methyl acrylate and glycidyl methacrylate as monomers, without remarkable reduction in mechanical strength, heat resistance and impact strength. A thermoplastic resin composition exhibiting a matting effect.

In general, PC resins have a high surface gloss, which is an advantage of plastic molded parts, but in some applications, excessive gloss can be a disadvantage, such as easy eye fatigue or visual impairment. For example, in applications such as automotive interiors, computer terminals, housings of office equipment and electrical and electronic products, a low gloss surface is required for eliminating visual disturbance effects and creating a luxurious atmosphere.

In order to meet the demand by reducing the surface gloss of the resin molded article, US Pat. Nos. 4,460,733 and 4,987,174 disclose a method of adding an inorganic filler such as silica, silicate, or alumina, but the matting effect is minimal. In the case of increasing the content of the additive to increase the matting effect, the mechanical properties such as impact strength are lowered and the fluidity is rapidly reduced, which shows a fatal disadvantage.

In order to solve the problems of the inorganic filler as described above, a method of adding a high molecular weight organic matting agent has been proposed, but there is a problem of causing not only impact strength but also other important physical properties such as thermal deformation temperature and light stability.

In particular, among the methods of adding a high molecular weight organic quencher, a method of adding a polymer having a glycidyl functional group has been proposed, and examples thereof include US Pat. Nos. 5,026,777, 4,902,745, 5,354,796, and 4,885,336. , 5,369,172, 5,369,154, 4,994,416, 5,430,101, 5,336,111 and 5,395,889. However, the high molecular weight organic matting agent has a disadvantage in that the glossiness is severely changed by the processing conditions together with the problem of deteriorating fluidity by causing a crosslinking reaction during processing.

In addition, as a method for reducing surface gloss, a technique for increasing melt flow characteristics by mixing polystyrene resins with PC resins has been generalized, but PC resins do not have good compatibility with polystyrene resins and thus do not exhibit good physical properties. have. In particular, the delamination caused by the shear force during injection molding appears and the impact strength is also low. In order to solve this problem, there is an example of using a low molecular weight organic additive such as a siloxane-based binder, but the disadvantage is that the effect is small when the polystyrene-based resin content increases.

The present invention has been made to solve the various problems of the conventional low-gloss PC resin composition as described above, the technical problem to be solved by the present invention is that there is no degradation of mechanical strength, heat deformation temperature and impact strength, during injection molding PC resin composition exhibiting significant quenching effect without occurrence of delamination. Ethylene having a functional group of glycidyl methacrylate, an impact modifier having an acrylic rubber mixed with silicone rubber as a core, and a polymethyl methacrylate as a shell. / Methyl acrylate copolymer and optionally an amide wax are added in an appropriate ratio to more efficiently increase the roughness of the surface of the resin molded article, and improve the flowability and transferability of the resin on the surface of the injection mold to induce diffused reflection of light PC resin composition having an excellent quenching effect by To provide the product.

The present invention

(A) 100 parts by weight of polycarbonate resin;

(B) 5 to 15 parts by weight of an impact modifier containing silicone-acrylic rubber as the core component and polymethylmethacrylate as the shell component; And

(C) relates to a polycarbonate resin composition comprising 0.5 to 10 parts by weight of a terpolymer containing ethylene, methyl acrylate and glycidyl methacrylate of formula (1) as monomers.

The invention also relates to an article made from the low gloss PC resin composition.

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

The PC resin of the component (A) can be prepared by methods known in the art from divalent phenols, carbonate precursors and molecular weight modifiers to control the molecular weight.

PC resin that can be used in the composition according to the present invention is an aromatic PC resin produced by condensation polymerization from bisphenol-A and phosgene or by transesterification of bisphenol-A with diphenyl carbonate and having a viscosity average molecular weight of 15,000 to 30,000. Preferred but not limited to use. If the viscosity average molecular weight is less than 15,000, the mechanical properties are inferior, and if the viscosity average molecular weight is more than 30,000, the melt flowability is poor, which causes problems in processing of the resin.

The impact modifier of component (B) uses an impact modifier of a structure in which silicone-acrylic rubber is a core and methyl methacrylate is a shell. There are various types of impact modifiers in which the rubber component is the core and the acrylate-based resin is the shell, and typically exhibits various physical properties depending on the type of the rubber component. The impact modifier of the structure in which the silicone rubber mixed with the silicone rubber (silicone-acrylic rubber) according to the present invention is a core and the polymethyl methacrylate is a shell is not impregnated with silicone rubber or compared with other types or structures of impact modifiers. The degree of protrusion and dispersion of the rubber component on the surface of the PC resin injection molding is excellent, the surface roughness is increased and the light reflection effect is more excellent by inducing diffuse reflection of light efficiently.

The silicone rubber to be penetrated into the rubber of the core structure is preferably 10 to 30% by weight, more preferably 12 to 20% by weight relative to 100% by weight of the total core component. If the amount of penetration is less than 10% by weight, the matting effect is insignificant, and if it exceeds 30% by weight, the flocculation phenomenon and dispersion efficiency of silicone rubber are decreased, impact efficiency is lowered, and manufacturing cost is increased.

The core structure may use various silicone-acrylic rubbers, but it is preferable to include dimethylsiloxane and butyl acrylate in consideration of the matting effect or other physical properties.

The impact modifier of component (B) may be added in an amount of 5 to 15 parts by weight based on 100 parts by weight of the PC component, and more preferably 8 to 12 parts by weight to provide an excellent synergistic effect with components (C) and (D). You can get it. If the amount thereof is less than 5 parts by weight, the matting effect is insignificant. If it is more than 15 parts by weight, the flowability and heat resistance are greatly reduced.

Terpolymer of the component (C) consisting of ethylene, methyl acrylate and glycidyl methacrylate of the formula (1) as a monomer to modify the surface of the PC resin injection molding to increase the roughness and light reflectance, It is added together with (B) or the following optional component (D) to show the matting synergistic effect.

3-9 weight% is preferable with respect to 100 weight% of tripolymers, and, as for the ratio of the glycidyl methacrylate which is a functional group in the said component, 5-7 weight% is more preferable. If the ratio is less than 3% by weight, the matting effect is insignificant, and if it exceeds 9% by weight, the flowability is greatly reduced due to the crosslinking reaction during processing. In addition, 20-50 weight% is preferable with respect to 100 weight% of trimers, and, as for the methylacrylate ratio in an ethylene / methylacrylate copolymer, 25-40 weight% is more preferable. If the ratio is less than 20% by weight, compatibility with the PC may be lowered to cause a layered peeling phenomenon, the flowability may be greatly reduced, and if the content is 50% by weight or more, the matting effect and impact strength may be lowered.

The copolymer of component (C) may be added in an amount of 0.5 to 10 parts by weight, and more preferably 1 to 5 parts by weight, based on 100 parts by weight of the PC component. If the amount thereof is less than 0.5 parts by weight, the matting effect is insignificant. If it is more than 10 parts by weight, the flowability and heat resistance are greatly reduced, and the delamination may occur during injection molding.

It is preferable that the low gloss PC resin composition according to the present invention further comprises an amide wax of component (D) represented by the following general formula (2).

Wherein n is an integer from 12 to 22.

The amide wax of the component (D) improves the flowability and transferability of the resin on the surface of the injection mold and improves the illuminance of the surface of the PC injection product and the diffuse reflectance of the light, compared to other release agents or internal lubricants. It is added together with (B) and (C) to exhibit a matting synergistic effect. The amide wax may be added in an amount of 0.1 to 0.5 parts by weight, and more preferably 0.1 to 0.3 parts by weight, based on 100 parts by weight of the PC resin. If the amount thereof is less than 0.1 part by weight, the matting effect is insignificant, and if the amount is more than 0.5 part by weight, it may cause gas defects such as silver wire and pinholes on the surface of the PC injection product. Can cause.

The low gloss PC resin composition of the present invention is an inorganic filler such as silica, silicate, alumina, glass fiber, glass beads, glass flakes, clay, talc, mica, calcium carbonate, etc. in order to further reduce surface gloss and increase heat resistance and dimensional stability. It may further contain, it may be incorporated in 1 to 50 parts by weight based on 100 parts by weight of the total resin composition. In addition, in order to increase the black color expression and conductivity of the resin composition, it may further contain organic fillers such as carbon fiber and carbon black, and may be incorporated in an amount of 1 to 30 parts by weight based on 100 parts by weight of the total resin composition.

In addition, the processing aid may further include an antioxidant, a heat stabilizer, a mold release agent, a lubricant, an ultraviolet stabilizer, and the like, which may be used in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the total resin composition.

The invention also relates to an article comprising the low gloss PC resin composition according to the invention. The products include interior materials and exterior materials that require low gloss, and specifically include, but are not limited to, automobile interior materials, computer terminals, office equipment and housings of electrical and electronic products.

Although the features and effects of the present invention will be described in more detail with reference to examples, the following examples are provided to illustrate the present invention, but the scope of the present invention is not limited by the following examples.

<Examples 1-8>

The raw materials were mixed with the composition components and contents shown in Table 1 below, and kneaded and extruded with a twin screw melt kneading extruder at a temperature of 280 to 300 ° C. to prepare a pellet for molding, and after hot air drying at 120 ° C. for 4 hours, 290 to 310 ° C. The specimen was prepared by injection molding at the temperature of. The surface glossiness of the low gloss PC resin composition thus prepared was measured at 60 ° angle according to ASTM D-523, and the flowability was melt index at 300 ° C. and 1.2 kg load condition according to ASTM D-1238. The heat deflection temperature was measured at a load of 18.6 kg according to ASTM D-648, and the delamination was evaluated visually by injecting a disc specimen having a diameter of 10 cm and a thickness of 3 mm. The physical property evaluation results thus measured are shown in Table 1 below.

Example number One 2 3 4 5 6 7 8 Furtherance Parts by weight PC ⁽¹⁾ 100 100 100 100 100 100 100 100 Core-shell impact modifier Silicone-Acrylic Rubber ⁽²⁾ 10 7 13 10 10 10 10 10 Acrylic Rubber ⁽³⁾ Butadiene Rubber ⁽⁴⁾ Ethylene with GMA E-GMA-MA ⁽⁵⁾ 5 5 5 One 8 5 5 5 E-GMA ⁽⁶⁾ Release component Amide Wax ⁽⁷⁾ 0.3 0.3 0.3 0.3 0.3 PETS ⁽⁸⁾ 0.3 GMS ⁽⁹⁾ 0.3 Properties 60 ° surface glossiness (%) 52 55 50 69 48 61 60 61 Flowability (g / 10min) 11 11 10 11 10 9 11 13 Heat Deflection Temperature (℃) 114 116 112 118 110 115 114 113 Delamination X X X X X X X X

<Comparative Examples 1-9>

The same materials and devices as in Example were used, except that the thermoplastic resin composition was melt-kneaded in the composition shown in Table 2 below.

Comparative example number One 2 3 4 5 6 7 8 9 Furtherance Parts by weight PC ⁽¹⁾ 100 100 100 100 100 100 100 100 100 Core-shell impact modifier Silicone-Acrylic Rubber ⁽²⁾ 10 10 20 10 Acrylic Rubber ⁽³⁾ 10 Butadiene Rubber ⁽⁴⁾ 10 Ethylene with GMA E-GMA-MA ⁽⁵⁾ 5 5 5 15 E-GMA ⁽⁶⁾ 5 Release component Amide Wax ⁽⁷⁾ One 0.3 0.3 PETS ⁽⁸⁾ GMS ⁽⁹⁾ Properties 60 ° surface glossiness (%) 99 82 90 89 81 78 50 49 43 Flowability (g / 10min) 12 11 11 10 11 6 13 8 8 Heat Deflection Temperature (℃) 129 121 118 115 119 118 112 105 103 Delamination X X X X X X O X O

(1) Samyang Co., Ltd. TRIREX 3022IR

(2) METABLEN S-2001 of Mitsubishi Rayon Corporation

 (The impact modifier of the structure wherein the acrylic rubber mixed with 15% by weight of the silicone rubber is the core and the polymethyl methacrylate is the shell with respect to 100% by weight of the total rubber)

(3) PARALOID EXL-2313 from KUREHA, Japan

(Improving agent of structure where acrylic rubber is core and polymethyl methacrylate is shell)

(4) PARALOID EXL-2602 from KUREHA, Japan

(Impact modifier of structure where butadiene rubber is core and methyl methacrylate / styrene copolymer is shell)

(5) IGETABOND 7M of Sumitomo Chemical Co., Ltd.

(Ethylene / methylacrylate copolymer having 6% by weight of glycidyl methacrylate as a functional group and 30% by weight of methyl acrylate based on 100% by weight of the total copolymer)

(6) IGETABOND 2C of Sumitomo Chemical Co., Ltd.

(Ethylene polymer having 6% by weight of glycidyl methacrylate as a functional group based on 100% by weight of the total copolymer)

(7) KAOWAX EB-FF of Kao

(8) LOXIOL EP861 from COGNIS DEUTSCHLAND GmbH, Germany

(Pentaerythritol Tetrastearate with molecular weight 1200)

(9) RIKEMAL S-100A of Riken Vitamin of Japan

(Glycerol Monostearate with molecular weight 358)

As shown in Tables 1 and 2, the resin compositions of Examples 1 to 8 according to the present invention have an excellent matting effect and no layered peeling phenomenon compared to the compositions of Comparative Examples 1 to 9, and the flowability and heat deformation temperature of the More similar. In Comparative Example 6, the flowability is remarkably lowered compared to the Examples, resulting in poor workability. In Comparative Examples 7 and 9, layered peeling occurs, and in Comparative Examples 8 and 9, the flowability and heat resistance are significantly lower than those in Examples. .

The low gloss PC resin composition according to the present invention minimizes the deterioration of the properties of the PC resin itself, and more efficiently increases the roughness of the surface of the resin molded article, and improves the flowability and transferability of the resin on the surface of the injection mold. Since it exhibits a remarkable matting effect by inducing it can be usefully used for automotive and electrical and electronic components that require properties such as low gloss, high impact, high heat resistance.

Claims (8)

(A) 100 parts by weight of polycarbonate resin; (B) 5 to 15 parts by weight of an impact modifier containing silicone-acrylic rubber as the core component and polymethylmethacrylate as the shell component; And (C) Polycarbonate resin composition comprising 0.5 to 10 parts by weight of a terpolymer containing ethylene, methyl acrylate and glycidyl methacrylate of the formula (1) as a monomer. [Formula 1]

The polycarbonate resin composition according to claim 1, further comprising 0.1 to 0.5 parts by weight of an amide wax represented by the following formula (2) based on 100 parts by weight of the polycarbonate resin. [Formula 2]

Wherein n is an integer from 12 to 22. The resin composition according to claim 1, wherein the polycarbonate resin has a viscosity average molecular weight of 15,000 to 30,000. The polycarbonate resin composition according to claim 1, wherein the silicone-acrylic rubber which is a core component of the impact modifier comprises 10 to 30 wt% of silicone rubber based on 100 wt% of the total core component. 5. The polycarbonate resin composition according to claim 4, wherein the silicone-acrylic rubber which is the core component of the impact modifier comprises butyl acrylate and dimethylsiloxane. The polycarbonate resin composition according to claim 1, wherein the glycidyl methacrylate is 3 to 9% by weight based on 100% by weight of the terpolymer. The polycarbonate resin composition according to claim 1, wherein the methyl acrylate is 20 to 50% by weight based on 100% by weight of the terpolymer. An article comprising the polycarbonate resin composition according to any one of claims 1 to 7.