KR101283740B1 - Thermoplastic resin composition for laser marking - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition for laser marking, and more particularly, the thermoplastic resin composition for laser marking according to the present invention comprises: 1) conjugated diene rubber latex, (meth) acrylic acid alkyl ester compound, aromatic vinyl monomer and vinyl cyan monomer Graft copolymer comprising a; 2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring; 3) thermoplastic elastomers; And 4) colorant comprising at least one of pigments and dyes. According to the present invention, the heat resistance of a marking article can be greatly improved, and when marking white letters or figures using a laser beam, the sharpness and foaming degree are excellent, and thus it is easy to apply to products such as automobiles, mobile phones, laptops, and keyboards. A thermoplastic resin composition can be provided.

Laser marking, heat resistance, whiteness, resin composition

Description

Thermoplastic resin composition for laser marking {THERMOPLASTIC RESIN COMPOSITION FOR LASER MARKING}

The present invention relates to a thermoplastic resin composition for laser marking. More specifically, the present invention relates to a thermoplastic resin composition used for marking letters or figures on a surface of a car, a mobile phone, a notebook, a keyboard, and the like, and has excellent clarity and foaming of the marked letters or figures, in particular, heat resistance and heat resistance. It relates to a thermoplastic resin composition for laser marking with improved chemical properties.

When displaying letters or symbols on the surface of plastics and semiconductors used as exteriors or parts of electrical and electronic components, tampon printing or silk screen printing is mainly used.

However, this printing method is contact type and uses printing ink and the like, so the fineness of printing is low, it is not permanent, the ink is scattered and solvents are used. Can cause.

Therefore, in order to solve the problem of such a printing method, in recent years, the method of displaying letters or symbols on the surface of a plastic product using laser light has spread.

Among the marking methods using laser light, there is a method of marking a letter or a figure by coating a resin on the marking surface and irradiating the laser light thereto. Specifically, the marking method includes a method in which a marking surface made of resin absorbs laser light, thereby thermally decomposes and swells, a method in which the laser light is evaporated and engraved, and a marking surface is instantaneously. Color change & bleaching by causing chemical changes.

These methods are very easy to design letters, symbols, etc. using a computer, or to change the design as needed, the marking process is fast and very sophisticated to obtain a uniform marking product, there is almost no defect rate .

In addition, since it is a non-contact marking method, it is possible to easily mark a portion such as a curved surface, which has not been conventionally marked, and since no solvent is used, there is no problem of contamination of the working environment and reuse of materials. Therefore, the laser marking method using the resin coating surface is rapidly expanding its area.

However, even in the case of laser marking in which a resin is coated on a marking surface and irradiated with laser light, the marked letters or symbols have a problem in that color development or sharpness differs according to the type of resin material. For example, when laser marking white letters on a black background resin, the color of the marked letters or symbols is often not clear due to oxidation and carbonization residues of the resin material.

In addition, when laser marking is applied to a product such as a car, a notebook, a mobile phone, or a keyboard, the marking part may be deformed or chemical crack may be caused by exposure to high temperature for a long time or contact with various chemicals. Can

Therefore, research is being conducted to solve these problems. For example, Japanese Patent Application Laid-Open No. 2001-139758 discloses (A) a (meth) acrylic acid ester (b) and, if necessary, an aromatic vinyl compound, a vinyl cyanide compound, and a maleic acid in the presence of a rubbery polymer (a). Rubber reinforced resin (A) obtained by superposing | polymerizing (a) + (b) + (c) = 100 weight%] of at least 1 sort (s) of monomer (c) chosen from the group of the mid type compound is described, (A 80-99 parts by weight of a rubber-reinforced resin having a (meth) acrylic acid ester (b) copolymerized in the component), 25 to 60% by weight, and (B) an ethylene- (meth) acrylic acid ester-carbon monoxide terpolymer 20 to 1 The thermoplastic resin composition for laser marking which mix | blended 0.01-5 weight part of (C) black compounds with respect to 100 weight part of total amounts of a weight part [(A) + (B) = 100 weight part] is described.

However, since the thermoplastic resin composition is excessively used in the black compound, the surface of the material is degraded during laser marking, and carbonization residues are deposited and it is difficult to obtain clear white letters and graphics. Recently, the frequency of use is increasing. When the marking portion is formed on the key touch portion, the white letter surface may be crushed and difficult to recognize.

In addition, Korean Patent Application Publication No. 2003-0056479 discloses (A) a rubber having a mean particle size of 0.1 to 0.2 µm (a ₁ ) 30 to 60 wt% (based on solid content) and a rubber having an average particle diameter of 0.3 to 0.6 µm (a ₂ 20 to 50 parts by weight of a rubbery polymer consisting of 70 to 40% by weight (based on solids); (B) 80 to 50 parts by weight of a monomer mixture consisting of 10 to 40% by weight of an aromatic vinyl monomer, 3 to 20% by weight of an unsaturated nitrile monomer and 40 to 80% by weight of an alkyl methacrylate monomer; (C) 0.5 to 1.5 parts by weight of a molecular weight regulator consisting of mercaptans and terpinolenic or alphamethylstyrene oligomer in a ratio of 1: 1 to 1: 2; (D) 0.2 to 1.0 parts by weight of the pigment; And (E) 0.2 to 1.0 parts by weight of the silicate compound; The thermoplastic resin composition for laser marking which consists of a is disclosed.

However, when the present inventors used the composition disclosed in the embodiments of the application specification for laser marking applications in automobiles, notebooks, and mobile phones, it was confirmed that deformation occurred due to a significant drop in heat resistance.

Accordingly, there is a need for a thermoplastic resin composition for laser marking that can improve whiteness and sharpness during laser marking, and in particular, has excellent heat resistance and chemical resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition for laser marking, which has excellent whiteness and clarity, in particular, which has improved heat resistance and chemical resistance, so as to improve the marking property of letters or figures during laser marking. .

In order to solve the above problems,

1) a graft copolymer comprising a conjugated diene rubber latex, a (meth) acrylic acid alkyl ester compound, an aromatic vinyl monomer and a vinyl cyan monomer;

2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring;

3) thermoplastic elastomers; And

4) colorant comprising at least one of pigment and dye

It provides a thermoplastic resin composition for laser marking comprising a.

In addition,

a) a graft copolymer comprising a1) conjugated diene rubber latex, (meth) acrylic acid alkylester compound, aromatic vinyl monomer and vinyl cyan monomer; a2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring; a3) thermoplastic elastomer; And a4) respectively preparing a colorant comprising at least one of a pigment and a dye; And

b) mixing the a1) graft copolymer, a2) (meth) acrylic copolymer, a3) thermoplastic elastomer and a4) colorant to prepare a thermoplastic resin composition

It provides a method for producing a thermoplastic resin composition for laser marking comprising a.

The present invention also provides an article formed using the thermoplastic resin composition, the article including a layer formed with letters or figures by laser marking.

According to the present invention, it is possible to improve whiteness and sharpness during laser marking, and in particular, to provide a thermoplastic resin composition for laser marking and a method of manufacturing the same having excellent heat resistance and chemical resistance of the marking surface.

Hereinafter, the present invention will be described in detail.

The thermoplastic resin composition for laser marking according to the present invention comprises: 1) a graft copolymer comprising a conjugated diene rubber latex, an alkyl (meth) acrylate ester compound, an aromatic vinyl monomer and a vinyl cyan monomer; 2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring; 3) thermoplastic elastomers; And 4) a colorant comprising at least one of pigments and dyes.

The thermoplastic resin composition for laser marking according to the present invention exhibits excellent chemical and heat resistance by a specific resin combination consisting of 1) a graft copolymer, 2) a (meth) acrylic copolymer, and 3) a thermoplastic elastomer, and 4) a colorant. By including it can improve the whiteness and sharpness when laser marking.

In the thermoplastic resin composition for laser marking according to the present invention, the content of the 1) graft copolymer, 2) (meth) acrylic copolymer, 3) thermoplastic elastomer and 4) colorant is not particularly limited, but graft air 20 to 75 parts by weight of the copolymer and 2) 25 to 80 parts by weight of the total of (meth) acrylic copolymer, 3) 1 to 20 parts by weight of the thermoplastic elastomer and 4) 0.0005 to 1 part by weight of the colorant.

The graft copolymer is not particularly limited as long as it is a graft copolymer including all of a conjugated diene rubber latex, an alkyl (meth) acrylic acid alkyl ester compound, an aromatic vinyl monomer and a vinyl cyan monomer, and preferably a conjugated diene rubber It may be prepared by graft copolymerization at a content ratio of 10 to 49% by weight of latex, 40 to 70% by weight of (meth) acrylic acid alkyl ester compound, 10 to 40% by weight of aromatic vinyl monomer, and 1 to 20% by weight of vinyl cyan monomer.

On the other hand, 1) the refractive index of the monomer mixture used in the preparation of the graft copolymer has a great influence on the transparency of the resin composition, this refractive index can be controlled by the amount of the monomer used and the mixing ratio.

Specifically, in order to exhibit transparency of the thermoplastic resin composition for laser marking according to the present invention, 1) the refractive index of the conjugated diene-based rubber latex used in the preparation of the graft copolymer and the remaining monomer components grafted thereto, that is, ( The refractive index after polymerization of the meth) acrylic acid alkylester compound, the aromatic vinyl monomer and the vinyl cyan monomer should be similar, and it is most preferable that the refractive index of the conjugated diene rubber latex coincides with the refractive index of the entire monomer component grafted thereto.

Therefore, it is preferable that the said 1) graft copolymer has the difference of the refractive index of the conjugated diene-type rubber latex and the refractive index after superposition | polymerization of a (meth) acrylic-acid alkylester compound, an aromatic vinyl monomer, and a vinyl cyan monomer less than 0.005.

1) The graft copolymer may use at least one mercaptan compound selected from the group consisting of n-dodecyl mercaptan and t-dodecyl mercaptan in order to adjust the molecular weight.

In addition, the 1) graft copolymer preferably has a weight average molecular weight of 80,000 to 300,000. 1) The graft copolymer of such a molecular weight is excellent in impact strength and fluidity of the thermoplastic resin composition final product for laser marking, thereby improving workability.

The method for preparing the graft copolymer 1 is not particularly limited, but may be preferably prepared by emulsion polymerization. 1) When the graft copolymer is prepared by bulk polymerization, the graft may not be performed well, and thus the gloss of the final product may be lowered, and a rubber having a large particle size may occur, thereby reducing the hardness of the resin composition. Can be.

The conjugated diene rubber latex may be a general butadiene rubber latex or styrene-butadiene copolymer rubber latex, preferably an average particle diameter of 800 to 3,500 kPa, gel content of 50 to 95wt%, swelling index 10 to 20 Can be used.

In addition, the conjugated diene-based rubber latex is contained in 1) the graft copolymer in an amount of 10 to 49% by weight, thereby further improving the impact strength of the resin composition.

The (meth) acrylic acid alkyl ester compound is, for example, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid decyl ester And (meth) acrylic acid lauryl ester can be used. In particular, methyl methacrylate which is preferably (meth) acrylic acid methyl ester can be used.

In addition, the (meth) acrylic acid alkyl ester may be further included in the 1) graft copolymer in an amount of 40 to 70% by weight, thereby further improving impact strength and transparency of the resin composition.

The aromatic vinyl monomer is not particularly limited, and for example, one or more selected from the group consisting of styrene, a-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene and vinyl toluene may be used. . In particular, styrene can be preferably used.

In addition, the aromatic vinyl monomer is included in 1) the graft copolymer in an amount of 10 to 40% by weight, thereby further improving transparency and processability of the resin composition.

The vinyl cyan monomer is not particularly limited, and for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile may be used.

In addition, the vinyl cyan monomer is included in 1) the graft copolymer in an amount of 1 to 20% by weight, thereby further improving the impact strength and transparency of the resin composition. Furthermore, it is possible to prevent the phenomenon that the color of the thermoplastic resin composition for laser marking changes to yellow and affects the color of the product.

In the present invention, the content of the alkyl methacrylate monomer in the 2) (meth) acrylic copolymer resin and the (meth) acrylic monomer including an aliphatic ring or an aromatic ring are in the range of 0.1 to 99.9% by weight, respectively. Can be selected. In particular, the alkyl methacrylate monomer is preferably 70 to 99.9% by weight, and the (meth) acrylic monomer including the aliphatic ring or the aromatic ring is preferably 0.1 to 30% by weight, but is not limited thereto. no.

The alkyl group of the alkyl methacrylate monomer is preferably 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably a methyl group or an ethyl group. Specific examples of the alkyl methacrylate monomer include methyl methacrylate, ethyl methacrylate, and the like, and methyl methacrylate is more preferred, but is not limited thereto.

The (meth) acrylic monomer containing the aliphatic ring or the aromatic ring is cyclohexyl methacrylate, benzyl methacrylate, cyclohexyl acrylate, 2-phenoxyethyl acrylate, 3,3,5-trimethylcyclohexyl meta One or more acrylates, phenyl methacrylates, naphthyl methacrylates, etc. may be used, but are not limited thereto.

In the present invention, the 2) (meth) acrylic copolymer resin may further include an imide monomer.

Examples of the imide monomer include maleimide, phenylmaleimide, cyclohexyl maleimide, and the like, but are not limited thereto.

3) The thermoplastic elastomer may enhance chemical resistance against various solvents in which the final product is contacted during actual use. In addition, it also serves to prevent the reduction of impact strength due to the dispersion and inorganic additives of various inorganic additives added as needed to promote foaming during laser marking.

The 3) thermoplastic elastomer is not particularly limited, and preferably thermoplastic urethane elastomer or thermoplastic amide elastomer can be used.

The thermoplastic urethane elastomer or the thermoplastic amide elastomer and the 1) graft copolymer and 2) the (meth) acrylic copolymer include amide groups in the thermoplastic urethane elastomer or the thermoplastic amide elastomer and the 1) graft copolymer and 2) (meth). Interactions such as secondary polar bonds between carboxyl groups in the acrylic copolymer have excellent compatibility with each other. Moreover, the interaction of the alkylether functional groups in the thermoplastic urethane elastomer or the thermoplastic amide elastomer with the styrene groups of 1) graft copolymers and 2) (meth) acrylic copolymers further improves their compatibility.

On the other hand, when the refractive index of the thermoplastic urethane elastomer or the thermoplastic amide elastomer is similar to 1) graft copolymer and 2) (meth) acrylic copolymer, the transparency of the overall blend composition may be maintained due to the interaction. For example, the transparency difference between the thermoplastic elastomer, 1) graft copolymer, and 2) (meth) acrylic copolymer may be formed as ± 0.01.

In addition, the thermoplastic urethane elastomer or thermoplastic amide elastomer is hydrophilic, so that the laser-marked product does not adsorb dust well during actual use, and improves low temperature impact resistance and elongation.

The colorant is not particularly limited as long as it includes at least one of pigments and dyes, preferably black pigments, black dyes, blue pigments and blue dyes can be used.

In addition, the 4) colorant can be prepared and used, for example, containing a mixture of a black pigment and a black dye and a mixture of a blue pigment and a blue dye.

The black pigments, black dyes or mixtures thereof used in the present invention absorb the laser beam energy to supply energy that the molecular chains of the resin composition polymer can swell and oxidize and decolorize themselves so that white letters or white figures appear. Plays an important role.

Therefore, the characteristics and the amount of use thereof have a great influence on the whiteness or sharpness of the letters or figures, and the kind or amount of use thereof may also affect the transparency or the color of the base surface.

The black pigment preferably has a particle size in the range of 17 to 40 nm. If the particle size is less than 17nm, the energy consumption during laser marking is large, and if the particle size exceeds 40nm, the tensile strength and impact strength of the resin composition may be lowered.

The kind of the black pigment is not particularly limited, and for example, carbon black having a particle diameter of 17 to 40 nm may be used.

The amount of the black dye used is preferably in the range of 0.001 to 0.2 parts by weight based on a total of 100 parts by weight of the graft copolymer and the (meth) acrylic copolymer.

On the other hand, the black dye is mainly used to control the background color and transparency of the transparent or translucent product. For example, in the case of using carbon black alone as a black pigment, the transparency can be controlled by using it in combination with a black dye having excellent dispersibility because there is a limit to the control of the transparency.

The amount of the black dye is preferably in the range of 0.0001 to 0.1 parts by weight based on a total of 100 parts by weight of the graft copolymer and the (meth) acrylic copolymer, in combination with other dyes in order to change the color of other background colors. Can be used.

In addition, the mixture of the black pigment and the black dye is preferably used in 0.0005 to 0.5 parts by weight based on a total of 100 parts by weight of the graft copolymer and the (meth) acrylic copolymer.

If the amount of black pigment is used too much, it is possible to mark with a small laser energy, but there are side effects such that the black pigment has a large amount of oxidized residue after oxidation, and there is less oxidized black pigment on the base surface, which causes the inside to shine. . In addition, the engraving effect is greater than the bulging effect due to excessive energy supply, and oxidation and carbonization of some resin compositions are promoted, so that the marked surface is not clean.

On the other hand, if the amount is too small, the lack of energy supply to the marking surface makes it difficult to swell the polymer chains, and the energy of the laser beam required for marking increases, resulting in yellowish yellow marking or insufficient laser marking. do. In the case of manufacturing a translucent marking product, the amount of black pigment or black dye is limited in order to maintain transparency, so it is necessary to increase the laser beam energy.

The blue dyes, blue pigments, or mixtures thereof used in the present invention are used to further improve the whiteness and sharpness of the characters or figures being marked. Blue dyes and blue pigments further enhance the whiteness of letters and graphics by offsetting the yellowishness produced by surface oxidation of parts of the product by the energy absorbed during laser marking.

In particular, as the amount of the material absorbing the laser beam energy, such as in the case of transparent or translucent products, the oxidation occurs because the intensity of the laser beam must be increased. At this time, by adjusting the blue dye or the blue pigment according to the degree of oxidation, it is possible to mark bright white letters or graphics.

Therefore, it is preferable that the said thermoplastic resin composition is used for marking white letters and figures.

The blue pigment and the blue dye are not particularly limited. For example, the blue pigment may be one or more compounds selected from the group consisting of phthalocyanine-based and cobalt blue-based compounds, and the blue dye may be an anthraquinone-based compound. Can be used.

In addition, the mixture of the blue pigment and the blue dye is preferably used in 0.0001 to 0.5 parts by weight based on a total of 100 parts by weight of the graft copolymer and (meth) acrylic copolymer as an auxiliary agent for improving the whiteness of the marking surface.

On the other hand, 4) colorant comprising at least one or one or more of the pigment and dye is preferably included in 0.0005 to 1 parts by weight based on a total of 100 parts by weight of the graft copolymer and (meth) acrylic copolymer.

4) When the colorant is added less than 0.0005, it is difficult to expect the desired whiteness and clarity, and when it contains more than 1 part by weight, oxidation and carbonization of the resin composition may be promoted to contaminate the marking surface. .

In addition, when the colorant is used as a black pigment, a black dye, a blue pigment and a blue dye, the amount of use thereof is preferably 5 to 30: 10 to 40: 1 to 10: 5 to 30 sequentially. Do.

Meanwhile, the resin composition for laser marking according to the present invention may further include titanium oxide as an inorganic additive. Titanium oxide acts to promote the foaming of the resin upon laser beam irradiation. In addition, titanium oxide is used for the purpose of adjusting the light transmittance of the product or improving the whiteness of the marked portion during laser marking.

Large particles of titanium oxide have excellent light blocking properties but are yellowish in color, so laser-marked letters or figures show slightly yellowish color, while small particles have a slightly blueish color, making the marked characters look cleaner. Therefore, the particle size range of the titanium oxide is preferably formed to 0.05 to 150mm.

In terms of helping the foaming of the resin, not only titanium oxide, but also various inorganic additives such as talc may be used.

In this case, it is preferable to make and use a master batch because the marked surface is uneven unless the dispersion of the inorganic additive is well done. On the other hand, when the amount of the inorganic additive is increased, the impact strength of the product may be lowered, but by the 3) thermoplastic elastomer included in the resin composition according to the present invention, the decrease in impact strength can be alleviated, It can improve acidity.

The amount of the inorganic additive is preferably in the range of 0.01 to 10 parts by weight based on a total of 100 parts by weight of the graft copolymer and the (meth) acrylic copolymer.

In addition, the manufacturing method of the thermoplastic resin composition for laser marking according to the present invention comprises: a) a1) a graft copolymer comprising a conjugated diene rubber latex, an alkyl (meth) acrylate ester compound, an aromatic vinyl monomer and a vinyl cyan monomer; a2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring; a3) thermoplastic elastomer; And a4) respectively preparing a colorant comprising at least one of a pigment and a dye; And b) mixing the a1) graft copolymer, a2) a (meth) acrylic copolymer, a3) a thermoplastic elastomer, and a4) a colorant to prepare a thermoplastic resin composition.

The method for producing a resin composition for laser marking according to the present invention can improve whiteness and sharpness when laser marking, and in particular, can easily prepare a thermoplastic resin composition for laser marking having excellent heat resistance and chemical resistance on a marking surface. have.

Specifically, the method of preparing the resin composition for laser marking comprises mixing all components such as the graft copolymer, the (meth) acrylic copolymer, the thermoplastic elastomer and the colorant, and extruding the resin composition at a temperature of about 200 to 260 ° C. The thermoplastic resin composition specimen for laser marking can be prepared by preparing in the form of a master batch pellet and injecting again at a temperature of about 200 to 260 ° C.

On the other hand, when the master batch pellets are prepared, antioxidants, heat stabilizers, lubricants, weathering enhancers, antistatic agents, antibacterial agents, and the like may be added, if necessary, and other colorants may be added to match colors.

The antioxidants, heat stabilizers, lubricants, weathering enhancers, antistatic agents and antimicrobial agents may use materials known in the art, so a detailed description thereof will be omitted herein.

The present invention also provides an article formed using the thermoplastic resin composition, the article including a layer formed with letters or figures by laser marking.

The article may be formed by coating the thermoplastic resin composition on the surface of the article using a coating method such as, for example, a spray coating method, a roll coating method, or a spin coating method, and forming a letter or a figure with a laser marker. It can manufacture by forming in a composition coating film.

The article is not particularly limited and may be selected from the group consisting of mobile phones, computers, notebook computers, keyboards, electronics, automotive interiors, furniture, desks, chairs, and building materials, for example.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are only for illustrating the present invention, and the protection scope of the present invention is not limited to the following Examples.

< Example >

< Example  1>

One) Graft  Copolymer

The acrylonitrile-butadiene-styrene-methylmethacrylate graft copolymer had a ratio of 3: 40: 15: 42 wt% and was prepared by an emulsion polymerization method. A g-ABS resin having a core-shell form having a refractive index of 1.516 and a weight average molecular weight of 120,000 was used.

2) ( Mat Acrylic Copolymer

Methyl methacrylate-cyclohexyl methacrylate (MMA-CHMA) copolymer, the ratio of the copolymer is 90: 10% by weight, the glass transition temperature and molecular weight of the prepared resin was measured, the glass transition temperature 125 ℃, molecular weight A resin of 130,000 was obtained.

3) Thermoplastic Elastomer

K407A (Kolon Oil Co., Ltd.) with a refractive index of 1.518 was used as the thermoplastic urethane elastomer.

4) Colorant

The black pigment is carbon black Pigment Black 06 (Nippie Korea), the black dye Diaresin Black B (Mitsubishi), the blue dye Macrolex Blue 3R (Bayer) and the blue pigment Ultramarine Blue 12 (Holiday). Used.

5) Preparation of Thermoplastic Resin Composition

30 parts by weight of the graft copolymer, 70 parts by weight of the (meth) acrylic copolymer, 3 parts by weight of thermoplastic elastomer and 0.05 parts by weight of black pigment, 0 parts by weight of black dye, 0.05 parts by weight of blue pigment and 0 parts by weight of blue dye Mixing to prepare a thermoplastic resin composition.

< Example  2>

A thermoplastic resin composition was prepared in the same manner as in Example 1, except that methyl methacrylate-phenyl methacrylate (MMA-PhMA) copolymer was used as the (meth) acrylic copolymer.

< Example  3>

A thermoplastic resin composition was prepared in the same manner as in Example 1, except that 5 parts by weight of the thermoplastic elastomer was mixed.

< Example  4>

A thermoplastic resin composition was prepared in the same manner as in Example 1, except that 0.01 part by weight of a black pigment, 0.015 part by weight of a black dye, 0.002 part by weight of a blue pigment, and 0.01 part by weight of a blue dye were mixed as a colorant.

< Comparative example  1>

A thermoplastic resin composition was prepared in the same manner as in Example 1, except that methyl methacrylate-styrene-acrylonitrile (MMA-SM-AN) three-component copolymer was used as the (meth) acrylic copolymer.

< Comparative example  2>

A thermoplastic resin composition was prepared in the same manner as in Example 1, except that the thermoplastic elastomer was not used.

< Experimental Example >

1) Laser Marking Evaluation

The thermoplastic resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2 were applied to metal plates, and graded by LG Chem's self-evaluation on the sharpness and whiteness of the marking with a model GY901 Nd: YAG Laser Marking Machine manufactured by EO TECHNICS.

2) Evaluation of Heat Deflection Temperature (HDT)

The thermoplastic resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2 were prepared on the basis of ASTM D648 to measure the heat deformation temperature.

3) Chemical resistance evaluation

The 1/8 inch tensile strength specimens prepared from the thermoplastic resin compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were fixed on a 0.7% strain jig, and then immersed in cyclopentane for 1 minute and then taken out for 4 hours. It was left at room temperature. At this time, the elongation of the specimens before and after immersion of cyclopentane was measured using an universal testing machine, and the elongation retention was calculated according to the following Equation 1.

[Equation 1]

Elongation retention = (elongation after immersion) × 100 / (elongation before immersion)

4) IZOD impact strength

The thermoplastic resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2 were prepared in a 1/8 inch specimen based on ASTM D256, and then made a notch, and the impact strength was measured using an IZOD impact tester.

5) Transparency

The transparency of the thermoplastic resin compositions of Examples 1 to 4 and Comparative Examples 1 and 2 was measured by the method described in ASTM D1003.

The experimental results of the experimental example are shown in Table 1 below.

As shown in Table 1, the thermoplastic resins prepared in Examples 1 to 4 were found to be excellent in both the marking resistance, heat resistance and chemical resistance. On the other hand, in the case of Comparative Example 1, which does not use the methyl methacrylate-cyclohexyl methacrylate (MMA-CHMA) copolymer as the (meth) acrylic copolymer, and Comparative Example 2, which does not use the thermoplastic elastomer, the heat resistance and the chemical resistance It can be seen that it is significantly reduced.

In addition, in Example 4 it was possible to obtain a semi-transparent resin excellent in heat resistance and marking properties by adjusting the color pigment and dye composition.

Claims (16)

1) 20 to 75 parts by weight of a graft copolymer comprising a conjugated diene rubber latex having an average particle diameter of 800 to 3,500 mm 3, an alkyl (meth) acrylic acid alkyl ester compound, an aromatic vinyl monomer and a vinyl cyan monomer; And 2) 25 to 80 parts by weight of a (meth) acrylic copolymer including an alkyl methacrylate monomer and a (meth) acrylic monomer including an aliphatic ring or an aromatic ring, based on a total of 100 parts by weight, 3) 1 to 20 parts by weight of thermoplastic elastomer; And 4) 0.0005 to 1 part by weight of a colorant comprising at least one of a pigment and a dye; Thermoplastic resin composition for laser marking comprising a. delete The method according to claim 1, wherein 1) the graft copolymer is 10 to 49% by weight conjugated diene-based rubber latex, 40 to 70% by weight (meth) acrylic acid alkyl ester compound, 10 to 40% by weight aromatic vinyl monomer, vinyl cyan monomer 1 To thermoplastic resin composition for laser marking, characterized in that prepared by graft copolymerization in an amount of 20 to 20% by weight. The laser according to claim 1, wherein the 1) graft copolymer has a difference in refractive index between the conjugated diene-based rubber latex and the refractive index after polymerization of the (meth) acrylic acid alkyl ester compound, aromatic vinyl monomer and vinyl cyan monomer is less than 0.005. Marking thermoplastic resin composition. The thermoplastic resin composition of claim 1, wherein the graft copolymer has a weight average molecular weight of 80,000 to 300,000. The thermoplastic resin composition for laser marking according to claim 1, wherein the conjugated diene rubber latex comprises at least one selected from the group consisting of butadiene rubber latex and styrene-butadiene copolymer rubber latex. The said (meth) acrylic-acid alkylester compound is a (meth) acrylic-acid methyl ester, (meth) acrylic-acid ethyl ester, (meth) acrylic-acid propyl ester, (meth) acrylic-acid 2-ethylhexyl ester, (meth) acrylic acid decyl A thermoplastic resin composition for laser marking, characterized in that it comprises one or more selected from the group consisting of esters and (meth) acrylic acid lauryl esters. The method of claim 1, wherein the aromatic vinyl monomer is characterized in that it comprises one or more selected from the group consisting of styrene, a-methyl styrene, p-methyl styrene, o-ethyl styrene, p-ethyl styrene and vinyl toluene. Thermoplastic resin composition for laser marking. The thermoplastic resin composition of claim 1, wherein the vinyl cyan monomer comprises at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile. The thermoplastic resin composition for laser marking according to claim 1, wherein the alkyl methacrylate monomer is methyl methacrylate or ethyl methacrylate. The method according to claim 1, wherein the (meth) acrylic monomer containing an aliphatic ring or an aromatic ring is cyclohexyl methacrylate, benzyl methacrylate, cyclohexyl acrylate, 2-phenoxyethyl acrylate, 3,3,5- A thermoplastic resin composition for laser marking, comprising at least one member selected from the group consisting of trimethylcyclohexyl methacrylate, phenyl methacrylate and naphthyl methacrylate. The thermoplastic resin composition for laser marking according to claim 1, wherein the 2) (meth) acrylic copolymer resin further comprises an imide monomer. The thermoplastic resin composition for laser marking according to claim 1, wherein the 3) thermoplastic elastomer comprises a thermoplastic urethane elastomer or a thermoplastic amide elastomer. The thermoplastic resin composition of claim 1, wherein the colorant comprises at least one selected from the group consisting of a black pigment, a black dye, a blue pigment, and a blue dye. a) a graft copolymer comprising a1) conjugated diene rubber latex, (meth) acrylic acid alkylester compound, aromatic vinyl monomer and vinyl cyan monomer; a2) a (meth) acrylic copolymer comprising an alkyl methacrylate monomer and a (meth) acrylic monomer comprising an aliphatic ring or an aromatic ring; a3) thermoplastic elastomer; And a4) respectively preparing a colorant comprising at least one of a pigment and a dye; And b) mixing the a1) graft copolymer, a2) (meth) acrylic copolymer, a3) thermoplastic elastomer and a4) colorant to prepare a thermoplastic resin composition Method for producing a thermoplastic resin composition of claim 1 comprising a. An article formed using the thermoplastic resin composition according to any one of claims 1, 3 to 14 and comprising a layer having letters or figures formed by laser marking.