KR100878571B1 - Transparent thermoplastic resin composition - Google Patents

Abstract

A transparent thermoplastic resin composition is provided to ensure high transparency and impact resistance, excellent chemical resistance and UV stability and to be applicable to the manufacture of a molded product including an exterior part or vehicle precision component of electric and electronic appliance. A transparent thermoplastic resin composition comprises (A) a polycarbonate resin 0.1-99.9 parts by weight, (B) a polyester resin 15-85 parts by weight and (C) a core-shell graft-copolymer 0.1-30 parts by weight. The core-shell graft-copolymer has the refractive index of 1.585 through 1.520.

Description

Transparent thermoplastic resin composition {TRANSPARENT THERMOPLASTIC RESIN COMPOSITION}

The present invention relates to a transparent thermoplastic resin composition, and more particularly, to a transparent thermoplastic resin composition having excellent transparency and high chemical resistance and impact resistance.

Polycarbonate resins have high heat resistance and transparency, and at the same time, they have been widely used for exterior materials of automobiles or interiors of automobiles due to their excellent physical properties. However, when only polycarbonate resin is used, sufficient impact resistance cannot be secured, and most of the cases where polycarbonate resin is used in parts requiring impact resistance due to problems such as easy breakage at the weak parts of manufactured parts after molding. Impact modifier is added. In the case of using such an impact modifier, the impact resistance of the polycarbonate resin is greatly improved, but the transparency of the resin is greatly impaired due to the difference in refractive index between the polycarbonate and the impact modifier used, thereby greatly reducing the color expression of the resin. There is a problem that makes it impossible to express deep color.

In order to solve this problem, there have been many attempts to increase the refractive index of the impact modifier in the process of manufacturing the impact modifier, but since the polycarbonate has a high refractive index (1.585), it has been considered impossible to completely match the refractive index of the polycarbonate and the impact modifier.

An object of the present invention is to provide a transparent thermoplastic resin composition having high transparency and excellent impact resistance, chemical resistance and UV stability.

However, technical problems to be achieved by the present invention are not limited to the above-mentioned problems, and other technical problems will be clearly understood by those skilled in the art from the following description.

The present invention (A) 0.1 to 99.9 parts by weight of a polycarbonate resin; (B) 0.1 to 99.9 parts by weight of polyester resin; (C) It provides a transparent thermoplastic resin composition comprising 0.1 to 30 parts by weight of the core-shell graft copolymer.

Other specific details of embodiments of the present invention are included in the following detailed description.

Although the thermoplastic resin composition of this invention is excellent in transparency, it is high in impact resistance, and also excellent in chemical resistance and UV stability. As a result, the present invention can be applied to manufacturing various molded articles such as exterior parts of electric and electronic products and automobile precision parts requiring high colorability.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is only defined by the scope of the claims to be described later.

It looks at in detail with respect to each component constituting the transparent thermoplastic resin composition according to an embodiment of the present invention.

(a) polycarbonate resin

The method for producing a polycarbonate resin suitable for the present invention and the use of the thermoplastic resin composition are well known to those skilled in the art, and thus a detailed description thereof will be omitted.

The polycarbonate resin may be prepared by polycondensation of dihydric phenol and phosgene in the presence of a molecular weight modifier and a catalyst, or may be prepared using an ester interchange reaction of a carbonate precursor such as dihydric phenol and diphenyl carbonate. Can be used.

The polycarbonate resin prepared by the above method may include linear polycarbonate, branched (bracnched) polycarbonate, polyester carbonate copolymer, silicone copolymer polycarbonate and the like.

As said dihydric phenol, bisphenol is preferable, and 2, 2-bis (4-hydroxyphenyl) propane called bisphenol A is especially preferable.

The bisphenol A can be partially or wholly replaced by another dihydricphenol. Dihydric phenols other than the bisphenol A are hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2, 2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, Halogenated bisphenols such as bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ether, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane and the like.

In addition, the polycarbonate resin may be a homopolymer or a copolymer using two or more dihydric phenols, or a mixture of these resins.

It is preferable to use bisphenol A type | system | group polycarbonate resin as said linear polycarbonate resin.

In addition, the branched polycarbonate may be prepared by reacting a polyfunctional aromatic compound such as trimellitic anhydride, trimellitic acid, and the like with dihydroxyphenol and a carbonate precursor.

The polyester carbonate copolymer may be prepared by reacting a bifunctional carboxylic acid with a dihydric phenol and a carbonate precursor.

The polycarbonate resin is preferably included in the range of 0.1 to 99.9 parts by weight, more preferably used in 10 to 90 parts by weight, even more preferably used in 15 to 85 parts by weight. When the content of the polycarbonate resin is within the above content range, it is preferable to easily adjust the refractive index by kneading with the polyester resin, thereby obtaining a thermoplastic resin composition having excellent transparency.

(b) polyester resin

The method of preparing the polyester resin and the thermoplastic resin composition usable in the present invention are well known to those skilled in the art, and thus detailed descriptions thereof will be omitted.

As polyester resin which can be used for this invention, it is preferable to use what has compatibility with polycarbonate resin. In order to produce a polyester having compatibility with the polycarbonate resin, it is necessary to prevent the crystallization of the polyester from proceeding. For this purpose, it is preferable to copolymerize in a polyester manufacturing process. In addition, since the crystallization does not proceed, the polyester resin of the present invention is not included in the liquid crystal polymer resin, and the polyester resin included in the liquid crystal polymer resin is excluded.

In the copolymerization method, a part of terephthalic acid, which is a repeating unit of the polyester main chain, is substituted with isophthalic acid or an alkyl chain composed of ethylene or butylene of polyester is substituted with cyclohexanedimethanol in the polymerization process. .

Accordingly, the polyester resin is a terephthalic acid and alkylene glycol as a repeating unit of the main chain, some of the repeating unit is preferably a copolyester resin substituted with isophthalic acid or cyclohexane dimethanol. As an example, the polyester resin in which cyclohexane dimethanol was copolymerized to polyethylene terephthalate is mentioned.

First, in the case of a polyester resin in which a part of terephthalic acid, which is a repeating unit of the polyester main chain, is substituted with isophthalic acid and copolymerized, the content of repeated isophthalic acid is preferably 5 mol% or more relative to the total content of terephthalic acid and isophthalic acid. Preferably it is 15 mol%-50 mol%. If the content of substituted isophthalic acid is 5 mol% or more, it is preferable because the crystallization of the polyester is prevented to obtain a thermoplastic resin composition having excellent transparency.

In addition, in the case of a polyester resin in which an alkyl chain composed of ethylene or butylene of polyester is substituted with cyclohexane dimethanol in a cyclic form, the content of the repeated cyclohexane dimethanol is equal to the total alkyl chain and cyclohexane dimethanol. It is preferable that it is 5 mol% or more with respect to the sum of the repeating number of, More preferably, it is 10 mol%-80 mol%. If the content of the substituted cyclohexane dimethanol is 5 mol% or more, crystallization of the polyester resin can be prevented and a thermoplastic resin composition having excellent transparency can be obtained.

The polyester resin may be used in 0.1 to 99.9 parts by weight, more preferably used in 10 to 90 parts by weight, even more preferably used in 15 to 80 parts by weight. When the content of the polyester resin is within the above range, it is preferable to adjust the refractive index by kneading with the polycarbonate resin and to improve the transparency of the entire thermoplastic resin composition.

As such, the amount of the polycarbonate resin and the polyester resin used in the transparent thermoplastic resin composition of the present invention is 0.1 to 99.9 parts by weight: 0.1 to 99.9 parts by weight, and when the mixing ratio therebetween is included in the above range, the refractive index of the mixture is By about 1.520 to about 1.585, the core-shell graft copolymer is made equal to the refractive index of this mixture. That is, since the refractive index increases when the content of the polycarbonate resin increases, and the refractive index decreases when the content of the polyester resin increases, when the mixing ratio of the polycarbonate resin and the polyester resin is determined, the mixed polycarbonate / polyester resin If the refractive index of is determined and this refractive index is equal to the refractive index of the core-shell graphite copolymer, it is preferable that the entire resin system maintains perfect transparency.

(c) core-shell graft copolymer with refractive index adjusted

The method of preparing a graft copolymer in the form of a core-shell may be controlled by using a comonomer in the manufacturing process, and the method of controlling the refractive index may be performed using conventional techniques in the art.

The core-shell graft copolymer preferably used in the present invention includes a shell in which a vinyl monomer is grafted to a core including a rubber system. The refractive index of the core-shell graft copolymer is preferably 1.520 to 1.585, more preferably 1.530 to 1.570. When the refractive index of the core-shell graft copolymer is less than 1.520, it is difficult to obtain a refractive index similar to that of the polycarbonate resin / polyester resin used in the transparent thermoplastic resin composition of the present invention, which may lower the transparency of the entire product. Even when the refractive index of the core-shell graft copolymer exceeds 1.585, it is also difficult to obtain a refractive index similar to that of the polycarbonate resin / polyester resin and thus the transparency may be lowered.

That is, the core-shell graft copolymer is a core-shell structure obtained by polymerizing a rubber monomer and then grafting a graftable vinyl monomer to a rubber monomer. In this case, the content of the rubber monomer in the core-shell graft copolymer is 20 to 90% by weight, and the vinyl monomer is preferably 80 to 10% by weight. When the content of the rubber monomer in the core-shell graft copolymer is less than 20% by weight, it is difficult to improve the impact resistance of the resin by the addition of the copolymer, so that the impact resistance of the whole product may be lowered, and the content of the rubber monomer is 90% by weight. If it exceeds the limit of the content used to control the refractive index is difficult to control the refractive index may reduce the transparency of the entire product.

The core includes one selected from the group consisting of diene rubber having 4 to 6 carbon atoms, acrylate rubber, silicone rubber monomer, and combinations thereof.

The diene rubber may be a diene rubber such as polybutadiene, poly (styrene-butadiene) or poly (acrylonitrile-butadiene), or a saturated rubber or ethylene-propylene-diene monomer terpolymer in which hydrogen is added to the diene rubber. Coalescence (EPDM) or the like can be used.

Examples of the acrylate rubber include acryl such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, or 2-ethylhexyl methacrylate. Rate monomers can be used. The curing agent used at this time is ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, allyl methacrylate, or tri Allyl cyanurate and the like.

Silicone rubbers can be obtained from cyclosiloxanes, for example hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenyl Cyclotetrosiloxane, and octaphenylcyclotetrasiloxane. One or more of these siloxanes may be selected to prepare a silicone rubber, and the curing agent used may include trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, or tetraethoxysilane.

As the graftable monomer, C ₁ -C ₈ methacrylic acid alkyl esters or C ₁ -C ₈ acrylic acid alkyl esters can be used, and these are 1 to 8 carbon atoms as esters of acrylic acid or methacrylic acid, respectively. Having a monohydryl alcohol. Specific examples of these include methacrylic acid methyl ester, methacrylic acid ethyl ester or methacrylic acid propyl ester, and of these, methacrylic acid methyl ester is most preferred.

As described above, there may be various methods for adjusting the refractive index of the core-shell graft copolymer. However, the most well known method is relative to the case where the diene rubber is used as the core in the manufacturing process of the core and the shell. There is a method of improving the total refractive index by further adding a styrene monomer having a high refractive index. In this case, in general, the content of the styrene monomer is preferably used in an amount of 10 to 80 parts by weight based on 100 parts by weight of the rubber monomer. When the content of the styrene monomer is less than 10 parts by weight, the refractive index control ability may be lowered, and when it is more than 80 parts by weight, the impact resistance may be reduced. In the case of using the diene rubber as a core, a method for improving the refractive index may be used in addition to the method of using the styrene monomer.

In addition, when using an acrylate rubber, an example of a method of improving the refractive index is a method of improving the refractive index by adjusting the content of n-butyl acrylate having a high refractive index. Of course, when using an acrylate rubber, there are various methods that are used commercially in addition to the method of adjusting the content of n-butyl acrylate as a method of improving the refractive index.

The refractive index control of the core-shell graft copolymer in the present invention can be obtained by controlling the content of various materials used in rubber production, and in the case of the core-shell graft copolymer, at least three materials are selectively selected. It is prepared by polymerization, and by adjusting the content of the material used at this time it is possible to control the refractive index of the entire core-shell graft copolymer.

In the present invention, the core-shell graft copolymer is preferably used in an amount of 0.1 to 30 parts by weight, more preferably 1 to 25 parts by weight, and even more preferably 4 to 20 parts by weight. When the core-shell graft copolymer is used in an amount of 0.1 to 30 parts by weight, the effect of impact reinforcement can be obtained, and mechanical strength such as tensile strength, flexural strength and flexural modulus is also excellent, which is preferable.

The thermoplastic resin composition of the present invention includes a polycarbonate resin having excellent impact resistance, heat resistance, transparency, etc. but having a high refractive index, and a polyester resin having a low impact resistance but high chemical resistance, excellent compatibility with a polycarbonate resin, and a low refractive index. In addition, since the core-shell graft copolymer having excellent impact resistance is included, both the impact resistance and the chemical resistance are excellent while having excellent transparency. That is, the core-shell graft copolymer is used as an impact modifier capable of reinforcing the impact resistance of the polycarbonate resin / polyester resin, and at this time, by adjusting the refractive index of the core-shell graft copolymer to 1.520 to 1.585 By adjusting similarly to the refractive index of the resin / polyester resin, transparency can be improved well.

The transparent thermoplastic resin composition may further include various additives depending on the use. Specifically, inorganic fillers such as glass fiber, carbon fiber, talc, silica, mica, and alumina may be added to further improve physical properties such as mechanical strength and heat deformation temperature. In addition, it may further include additives such as UV absorbers, heat stabilizers, antioxidants, light stabilizers, flame retardants, lubricants, dyes, pigments.

Although the thermoplastic resin composition of this invention is excellent in transparency, it is high in impact resistance, and also excellent in chemical resistance and UV stability. As a result, the present invention can be applied to manufacturing various molded articles such as exterior parts of electric and electronic products and automobile precision parts requiring high colorability.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited by the following examples.

Example

(A) polycarbonate resin, (b) polyester resin and (c) core-shell graft copolymer used in Examples 1 to 2 and Comparative Examples 1 to 2 are as follows.

(a) polycarbonate resin

The polycarbonate resin used PANLITE L-1250WP of TEIJIN, Japan as a bisphenol-A linear polycarbonate having a weight average molecular weight of 25,000 g / mol.

(b) polyester resin

JN100 manufactured by SK Chemical Co., Ltd., in which cyclohexane dimethanol was copolymerized with polyethylene terephthalate, was used.

(c) core-shell graft copolymers

A core-shell graft copolymer grafted with butadiene rubber with 10-30 parts by weight of methyl methacrylate graftable monomer and 20-60 parts by weight of styrene monomer, each having a refractive index of (c1) 1.575, Three core-shell graft copolymers (c2) 1.570 and (c3) 1.565 were used.

Examples A-1 to C-3

The polycarbonate resin, the polyester resin and the core-shell graft copolymer were mixed according to the composition ratios shown in Tables 1 to 3 below to prepare pellets using a twin screw extruder having Φ = 45 mm. In this case, the core-shell graft copolymer used was a core-shell graft copolymer having a refractive index adjusted to 1.575, 1.570, and 1.565, respectively.

The prepared pellets were dried at 110 ° C. for at least 3 hours, and then injected into a 10 oz injection machine under molding conditions of 280 to 320 ° C. and mold temperatures of 60 to 90 ° C. to prepare physical specimens.

Comparative Examples A-1 to C-7

As shown in Tables 1 to 3, except that the composition of each component was changed, the specimens were prepared in the same manner as in Examples A-1 to C-3.

The physical properties of the specimens prepared as described above were evaluated in the following manner, and the results are shown in Tables 1 to 3 according to the refractive index of the core-shell graft copolymer.

(1) Tensile strength (unit: kgf / ㎠): The tensile strength was measured according to ASTM D638.

(2) Impact strength (unit: kgfcm / cm): Notched Izod impact strength (1/8 ") was measured according to ASTM D256.

(3) Chemical resistance: Change in tensile strength before and after treatment in accordance with ASTM D638 standard by injecting tensile specimen conforming to ASTM D638 standard and treating oleic acid for 1 hour while applying 2.1% strain. Was measured and expressed as% value.

(4) Transparency: The specimens each having a thickness of 1.0 mm were injected and measured Haze in the thickness direction using a Hazemeter (NDH 2000, manufactured by Nippon Denshoku).

Example Comparative example Furtherance division A-1 A-2 A-3 A-1 A-2 A-3 A-4 A-5 A-6 A-7 Polycarbonate (a) 66.5 63 56 95 90 80 - - - 70 Polyester (b) 28.5 27 24 - - - 95 90 80 30 Core-shell graft copolymer (refractive index: 1.575) (c1) 5 10 20 5 10 20 5 10 20 - Properties The tensile strength  ASTM D638 650 630 600 670 650 610 630 620 590 680 Impact strength, IZOD ASTM D256 65 68 70 66 68 69 63 68 70 8 Reduced chemical resistance 14% 13% 13% 70% 58% 43% 10% 10% 9% 18% Transparency, Haze 2% 4% 4% 27% 32% 33% 45% 57% 63% One%

Example Comparative example Furtherance division B-1 B-2 B-3 B-1 B-2 B-3 B-4 B-5 B-6 B-7 Polycarbonate (a) 47.5 45 40 95 90 80 - - - 50 Polyester (b) 47.5 45 40 - - - 95 90 80 50 Core-shell graft copolymer (refractive index: 1.570) (c2) 5 10 20 5 10 20 5 10 20 - Properties The tensile strength ASTM D638 630 610 590 640 620 590 620 600 580 650 Impact strength, IZOD ASTM D256 67 70 72 65 68 70 69 69 70 6 Reduced chemical resistance 8% 6% 5% 68% 57% 40% 7% 7% 4% 12% Transparency, Haze 3% 3% 5% 36% 37% 40% 32% 36% 39% One%

Example Comparative example Furtherance division C-1 C-2 C-3 C-1 C-2 C-3 C-4 C-5 C-6 C-7 Polycarbonate (a) 28.5 27 24 95 90 80 - - - 30 Polyester (b) 66.5 63 56 - - - 95 90 80 70 Core-shell graft copolymer (refractive index: 1.565) (c3) 5 10 20 5 10 20 5 10 20 - Properties The tensile strength ASTM D638 610 590 580 650 630 610 620 610 600 630 Impact strength, IZOD ASTM D256 69 70 73 67 68 72 63 67 68 5 Reduced chemical resistance 6% 5% 5% 69% 60% 48% 5% 4% 3% 10% Transparency, Haze 2% 4% 5% 48% 53% 59% 24% 27% 29% One%

As shown in Tables 1 to 3, the thermoplastic resins of Examples A-1 to C-3 adjust the ratio of the polycarbonate resin and the polyester resin to match the refractive index of the core-shell graft copolymer and the whole resin. As a result, it is possible to obtain a property of high impact resistance and high chemical resistance and excellent transparency.

However, when using only polycarbonate as shown in Comparative Examples A-1 to A-3, B-1 to B-3 and C-1 to C-3, there is a problem in that the chemical resistance and transparency are greatly reduced, and Comparative Example A When only polyester is used, as shown in -4 to A-6, B-4 to B-6, and C-4 to C-6, chemical resistance is maintained at a high level, but transparency is also lowered. In addition, when the core-shell graft copolymer is not added as shown in Comparative Examples A-7, B-7, and C-7, transparency may be maintained, but impact resistance may be very low.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible for a person with ordinary skill in the art within the scope of the technical idea of this invention. .

Claims (11)

(A) 0.1 to 99.9 parts by weight of a polycarbonate resin; (B) 15 to 85 parts by weight of the polyester resin; And (C) 0.1 to 30 parts by weight of the core-shell graft copolymer Transparent thermoplastic resin composition comprising a. The method of claim 1, The core-shell graft copolymer is a transparent thermoplastic resin composition having a refractive index of 1.520 to 1.585. The method of claim 1, The content of the polycarbonate resin is 10 to 90 parts by weight, the content of the core-shell graft copolymer is 1 to 25 parts by weight transparent thermoplastic resin composition. The method of claim 3, The content of the polycarbonate resin is 15 to 85 parts by weight, the content of the core-shell graft copolymer is 4 to 20 parts by weight of the transparent thermoplastic resin composition. The method of claim 1, The polycarbonate resin is a transparent thermoplastic resin composition prepared by polycondensation reaction of dihydric phenol and phosgene or by ester interchange reaction of dihydric phenol and carbonate precursor. The method of claim 1, The polyester resin is a terephthalic acid and alkylene glycol as a repeating unit of the main chain, a part of the repeating unit is a transparent thermoplastic resin composition is a copolyester resin substituted with isophthalic acid or cyclohexane dimethanol. The method of claim 6, The copolyester resin is a transparent thermoplastic resin composition isophthalic acid or cyclohexane dimethanol is substituted with 5 mol% or more. The method of claim 1, The polyester resin is a glycol-modified polyethylene terephthalate is a transparent thermoplastic resin composition. The method of claim 1, The core-shell graft copolymer is a transparent thermoplastic resin composition obtained by grafting 80 to 10% by weight of a vinyl monomer to 20 to 90% by weight of a rubber monomer. The method of claim 1, The thermoplastic resin composition further comprises an additive selected from the group consisting of inorganic fillers, ultraviolet absorbers, heat stabilizers, antioxidants, light stabilizers, flame retardants, lubricants, pigments, dyes, and mixtures thereof. A molded article manufactured using the transparent thermoplastic resin composition according to any one of claims 1 to 10.