KR20070019481A - Preparation method of transparent copolymer resin having good rockwell hardness and high scratching resistance, and copolymer resin prepared by the method - Google Patents

Abstract

The present invention adds a molecular weight regulator, an organic peroxide initiator, and an antioxidant as an essential component to a mixture containing a styrene monomer, an acrylate monomer, and an acrylonitrile monomer, thereby continuously bulk polymerization the hardness, scratch resistance, and chemical resistance. The present invention provides a method for producing a transparent copolymer resin which is excellent in blending with other polymer resins and a copolymer thereof.

Transparent copolymer resin, chemical resistance, high hardness, scratch resistance, bulk polymerization

Description

Preparation method of transparent copolymer resin having good rockwell hardness and high scratching resistance, and copolymer resin prepared by the method

The present invention relates to a method for producing a transparent copolymer having excellent hardness, scratch resistance and chemical resistance, and a copolymer thereof. More particularly, the present invention can be used to prepare a scratch resistant resin plate having excellent hardness and transparency. The present invention relates to a method for producing a styrene-acrylonitrile-acrylate-based transparent copolymer capable of easily adjusting refractive index and fluidity and having excellent chemical resistance, and capable of various blending with other resins such as ABS resins and polymers thereof.

Recently, as the industry is advanced and actively pursuing differentiation of products, researches on the development of transparent materials have been actively conducted to introduce a design revolution by introducing a nude fashion culture and pastel color culture to products.

Transparent materials, such as transparent resin plates, for example, have been widely used as display panels, such as front panels for projection televisions. In order to be used in the display industry, in addition to simple transparency, various physical properties such as high hardness, scratch resistance, colorability, chemical resistance, hygroscopicity and weather resistance are required. As a substrate for a front panel for a display, a polymethyl methacrylate (hereinafter referred to as "PMMA") plate has been mainly used conventionally. However, PMMA plates have a high degree of expansion or contraction, which may cause distortion of the substrate due to moisture absorption, which may cause deformation of the display phase and cause contact between the substrate and the components inside the front panel. have. In addition, the polymerization rate is high and the viscosity of the polymerization solution is high, making it difficult to prepare by solution polymerization or bulk polymerization, as well as disadvantages of poor fluidity and chemical resistance. Compared to PMMA, Japanese Laid-Open Patent Publication No. 11-7251 et al proposes to use methyl methacrylate-styrene copolymer resin, but this also improves fluidity and hygroscopicity due to styrene, but still has chemical resistance and colorability. And poor weather resistance.

Accordingly, there is a need to develop a transparent resin having excellent hardness, scratch resistance, and chemical resistance, all of which are suitable for use in a field requiring a transparent material such as a display panel.

Accordingly, the first technical problem to be achieved by the present invention is to provide a method for preparing a new transparent copolymer having excellent strength, scratch resistance and chemical resistance.

The second technical problem to be achieved by the present invention is to provide a transparent copolymer prepared by the above method.

The third technical problem to be achieved by the present invention is to provide a blend resin composition comprising a transparent copolymer prepared by the above method.

The above problems of the present invention can be achieved by the configuration of the present invention described below.

In order to achieve the first technical problem, the present invention provides a continuous polymerization process by adding an antioxidant, a molecular weight regulator, and an organic peroxide initiator to a mixture comprising a styrene monomer, an acrylate monomer, and an acrylonitrile monomer. Provided are methods for preparing the transparent copolymer.

In another aspect, the present invention provides a transparent copolymer prepared by the above method in order to achieve the second technical problem.

In another aspect, the present invention provides a blend resin composition comprising 40 to 70% by weight of the transparent copolymer and 30 to 60% by weight of acrylonitrile-butadiene-styrene (ABS) resin in order to achieve the third technical problem.

The copolymer prepared by the method for producing a transparent copolymer according to the present invention has excellent physical properties such as transparency, hardness, chemical resistance, scratch resistance, and the like, and a resin composition obtained by blending the copolymer with another copolymer, in particular, an ABS resin. Silver has excellent physical properties such as impact resistance, rigidity and transparency.

Hereinafter, the present invention will be described in more detail.

In the method for preparing a transparent copolymer of the present invention, an antioxidant, a molecular weight regulator, and an organic peroxide initiator are added to a mixture of a styrene monomer, an acrylate monomer, and an acrylonitrile monomer to continuously bulk polymerize to prepare a transparent copolymer resin. Characterized in that.

Specifically, the manufacturing method of the present invention,

(1) mixing 10 to 20% by weight of styrene monomer, 50 to 60% by weight of acrylate monomer, 3 to 15% by weight of acrylonitrile monomer and 20 to 30% by weight of reaction medium;

(2) to 100 parts by weight of the mixture of step (1),

          (i) 0.01 to 1.0 parts by weight of hindered phenolic antioxidant and phosphite antioxidant;

           (ii) 0.01 to 1.0 parts by weight of molecular weight modifier; And

           (iii) 0.01 to 0.1 parts by weight of organic peroxide initiator

Adding to prepare a reaction mixture; And

(3) The reaction mixture of step (2) is polymerized in a first step at a temperature of 120 to 140 ° C. for 2 to 4 hours, and then heated in a second step to a temperature of 130 to 150 ° C. for 2 to 4 hours. During the polymerization.

In the step (1),

The content of the styrene monomer used in the method for producing a transparent copolymer according to the present invention is preferably in the range of 10 to 20% by weight. If the content of the styrene-based monomer is less than 10% by weight, there is a problem in that the viscosity of the reactant is high and the processability and fluidity of the produced product are deteriorated.When the content of the styrene monomer is greater than 20% by weight, the refractive index of the obtained transparent copolymer is increased and transparency is inferior. There is a problem.

In addition, the content of the acrylate monomer used in the method for producing a transparent copolymer according to the present invention is preferably in the range of 50 to 60% by weight. When the content of the acrylate monomer is less than 50% by weight, there is a problem that the refractive index of the obtained transparent copolymer is increased and the haze is increased. When the content of the acrylate monomer is more than 60% by weight, the viscosity of the reactant is rapidly increased. have.

In addition, the content of the acrylonitrile monomer used in the method for producing a transparent copolymer according to the present invention is preferably 3 to 15% by weight. When the content of the acrylonitrile monomer is less than 3% by weight, there is a problem in that the chemical resistance of the obtained transparent copolymer is significantly lowered, and when the content of the acrylonitrile-based monomer is more than 15% by weight, thermal discoloration of the obtained transparent copolymer occurs badly.

In addition, the content of the reaction medium used in the method for producing a transparent copolymer according to the present invention is preferably 20 to 30% by weight. If the reaction medium is less than 20% by weight, there is a problem in that the viscosity of the reactant is sharply increased, and if it exceeds 30% by weight, the molecular weight is low and the productivity is low. In the present invention, the reaction medium serves as a reaction lubricant to enable mass polymerization to occur efficiently rather than as a solvent. Thus, the polymerization process of the present invention uses a reaction medium, but the polymer is formed in the form of a bulk polymerization rather than a solution polymerization.

The styrenic monomers used in the method for preparing a transparent copolymer according to the present invention consist of styrene, α-methylstyrene and styrene in which at least one of each carbon of the benzene nucleus is optionally substituted with an alkyl group or halogen of C ₁ to C ₅ . It is preferable that it is at least one selected from the group.

In addition, the acrylate monomer used in the method for preparing a transparent copolymer according to the present invention is composed of methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, methyl acrylate and ethyl acrylate. It is preferable that it is at least one selected from the group.

In addition, the acrylonitrile monomer used in the method for producing a transparent copolymer according to the present invention is preferably one or more selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile.

In addition, the reaction medium used in the method for producing a transparent copolymer according to the present invention is preferably one or more selected from the group consisting of C ₁ to C ₃ alkyl groups or C ₆ to C ₉ aromatic hydrocarbon compounds optionally substituted with halogen. More preferably at least one medium selected from the group consisting of ethylbenzene, toluene and xylene.

In addition, in the step (2),

The content of the hindered phenolic antioxidant and the phosphite antioxidant used in the method for producing a transparent copolymer according to the present invention is preferably 0.01 to 1.0 parts by weight based on 100 parts by weight of the mixture of step (1). More preferably, it is 0.1-0.5. When the content of the antioxidant is less than 0.01 parts by weight, there is a problem that yellowing due to thermal history occurs in a high temperature volatilization tank, and when it exceeds 1.0 parts by weight, there is a problem that the refractive index increases due to the reduction of the conversion rate.

The antioxidant used in the present invention is used to suppress the yellowing of the polymer at a high temperature, and it is preferable to use a mixture of a hindered phenolic antioxidant and a phosphite antioxidant. In addition, the composition ratio of the hindered phenolic antioxidant: phosphite-based antioxidant in the antioxidant mixture is preferably 9: 1 to 1: 5, more preferably 5: 1 to 1: 3, most preferably 2: 1 to 1: 2. Phenolic antioxidant: The composition ratio of the phosphite antioxidant is greater than 1: 5, so that the content of the phosphite system is weak, which causes a weak problem in the thermal history of the obtained polymer during polymerization. When the content of is decreased, the polymer obtained is vulnerable to heat history in the volatilization and heat history during processing.

The hindered phenolic antioxidant used in the method for preparing the transparent copolymer according to the present invention is tetrakis methylene 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid methane, 1,3,5 -Tris- (4-t-butyl-3-hydroxy-2,6-dimethyl benzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione ) And 1,3,5-tris- (3,5-di-t-butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) -trione It may be selected from the group consisting of one or more, the phosphite-based antioxidant may be selected from the group consisting of tris (2,4-t- butyl phenyl) phosphite and tris- (nonylphenyl) phosphite .

In addition, the content of the molecular weight modifier used in the method for producing a transparent copolymer according to the present invention is preferably 0.01 to 1.0 parts by weight, more preferably 0.01 to 0.2 parts by weight based on 100 parts by weight of the mixture of step (1). When the amount of the molecular weight modifier is less than 0.01 parts by weight, there is a problem in that the operation is difficult due to the high viscosity of the polymer, and when it exceeds 1.0 parts by weight, the molecular weight of the polymer obtained is low and the impact strength is lowered.

The molecular weight modifier used in the method for producing a transparent copolymer according to the present invention is one or more selected from the group consisting of t-dodecyl mercaptan and n-octyl mercaptane. desirable.

In addition, the amount of the organic peroxide initiator used in the method for preparing a transparent copolymer according to the present invention is preferably 0.01 to 0.1 parts by weight, more preferably 0.02 to 0.1 based on 100 parts by weight of the mixture of step (1). . If the amount of the organic peroxide initiator is less than 0.01 part by weight, there is a problem in that the yield is low and thermal discoloration occurs due to the difference in the composition ratio in the polymer, and when it exceeds 1.0 part by weight, the polymerization reaction occurs rapidly to control the reaction pressure and the heat of reaction. Is very difficult, there is a problem that the viscosity of the reactants is rapidly increased by the gel effect (gel effect).

Organic peroxide initiators used in the process for preparing the transparent copolymers according to the present invention include 1,1-bis (t-butyl peroxy) cyclohexane, 1,1-bis (t-butyl peroxy) 2-methyl cyclohexane and It is preferably at least one selected from the group consisting of 1,1-bis (t-butyl peroxy) -3,3,5-trimethyl cyclohexane.

In the method for preparing a transparent copolymer according to the present invention, the addition of the additives of the step (2) to the mixture of the step (1) does not necessarily have to be added after the mixture of the step (1) is prepared and at the same time It may be introduced, and the present invention is not limited by the order.

Next, in step (3),

While the mixture of step (1) and the additive of step (2) are added to the reactor, polymerization is carried out at a temperature of 120 to 140 ° C. for 2 to 4 hours in a first step, and then 130 to 150 in a second step. The polymerization is carried out for 2 to 4 hours by raising the temperature to ℃.

In the first stage of polymerization, the reaction temperature is preferably 120 to 140 ° C. If the temperature is less than 120 ° C, the initiator efficiency is low, and the conversion rate is low. If the temperature is higher than 140 ° C, the molecular weight of the obtained polymer is low. The polymerization time is preferably 2 to 4 hours. If less than 2 hours, there is a problem that the conversion rate is low, and if more than 4 hours there is a problem that the operation is difficult due to the high viscosity.

In the second stage of polymerization, the reaction temperature is preferably 130 to 150 ° C. If the temperature is less than 130 ° C., there is a problem that the conversion rate is low and the yield decreases. If the temperature is higher than 150 ° C., the molecular weight of the obtained polymer is low. The polymerization time is also preferably 2 to 4 hours. If it is less than 2 hours, there is a problem in that the conversion rate is low and the refractive index is high. If it is more than 4 hours, there is a problem in that the impact strength is lowered because the molecular weight is low.

The present invention provides a transparent copolymer prepared by the above production method.

That is, when the polymerization conversion is about 60% or more after the second step polymerization, the transparent copolymer may be obtained in pellet form by removing the unreacted monomer and the reaction medium at a temperature of 200 to 240 ° C. in a volatilization tank.

The transparent copolymer prepared according to the present invention has a haze of 1.0 or less, a Rockwell hardness of 120 or more, a pencil hardness of 2H or more, and excellent chemical resistance.

Next, the blend resin composition which concerns on this invention is demonstrated.

Blend resin composition of the present invention comprises 40 to 70% by weight of the transparent copolymer according to the invention and 30 to 60% by weight ABS resin. When the transparent copolymer according to the present invention is 70% by weight or more, there is a problem that the impact falls, and when the transparent copolymer is less than 40% by weight, there is a problem of increasing the haze and color characteristic values b. If the b value is greater than 2, the color becomes too yellow and there is a problem in that the quality is not good when producing the product.

The blend resin composition according to the present invention may be used in various fields having excellent physical properties such as transparency, impact resistance and high gloss.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples, and variations, modifications, and the like that maintain the basic idea of the present invention are understood to be included in the scope of the present invention.

Example

Example  One

(Production of Transparent Copolymer)

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 16.72 wt% styrene, 59.28 wt% methyl methacrylate, 4 wt% acrylonitrile, and 20 wt% toluene -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.1 parts by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.02 parts by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butyl as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was introduced into a 26 L reactor at a rate of 14 L / hr, followed by polymerization at a temperature of 140 ° C. in a first step, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, the pellet was removed by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatile tank A clear copolymer was prepared.

Example  2

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 16.37% by weight of styrene, 58.03% by weight of methyl methacrylate, 5.6% by weight of acrylonitrile and 20% by weight of toluene -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.1 part by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.015 part by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butyl as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, pellets form by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatile tank Transparent to prepare a copolymer.

Example  3

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 15.84% by weight of styrene, 56.16% by weight of methyl methacrylate, 8% by weight of acrylonitrile and 20% by weight of toluene -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.2 part by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.01 part by weight of n-dodecyl mercaptan as the molecular weight regulator and 1,1-bis (t-butyl as the organic peroxide initiator The reaction mixture to which 0.015 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, pellets form by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatile tank Transparent to prepare a copolymer.

Example  4

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 15.49% by weight of styrene, 54.91% by weight of methyl methacrylate, 9.6% by weight of acrylonitrile and 20% by weight of toluene -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.3 part by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.01 part by weight of n-dodecyl mercaptan as a molecular weight regulator, and 1,1-bis (t-butyl as an organic peroxide initiator The reaction mixture to which 0.015 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, pellet form by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatilization tank A transparent copolymer of was prepared.

Example  5

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 14.88% by weight of styrene, 59.52% by weight of methyl methacrylate, 5.6% by weight of acrylonitrile and 20% by weight of toluene. -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.1 part by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.15 part by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butyl as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, pellets form by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatile tank Transparent to prepare a copolymer.

Example  6

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 17.86 wt% styrene, 56.54 wt% methyl methacrylate, 5.6 wt% acrylonitrile, and 20 wt% toluene -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.1 parts by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.15 parts by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butyl as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by raising the temperature to ℃, the polymerization conversion was 60% or more, pellets form by removing the unreacted monomer and the reaction medium at a temperature of 215 ℃ in a volatile tank Transparent to prepare a copolymer.

Comparative example  One

1,3,5-tris (4-tert-butyl-3-hydroxy-2, as a hindered phenolic antioxidant in a mixture of 17.6 wt% styrene, 62.4 wt% methyl methacrylate and 20 wt% toluene 6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione and tris (2,4-di-t-butylphenyl as phosphite-based antioxidants 0.1 parts by weight of a 1: 1 mixture of phosphite antioxidants, 0.08 parts by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butylperoxy) -3,3,5- as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in the first step while being charged into a 26 L reactor at a rate of 14 L / hr, followed by polymerization at a temperature of 150 ° C. in the second step, followed by polymerization conversion rate. When the content was about 60% or more, the unreacted monomer and the reaction medium were removed at a temperature of 215 ° C. in a volatilizer to prepare a transparent copolymer in pellet form.

Comparative example  2

1,3,5-tris (4-tert) as a hindered phenolic antioxidant in 100 parts by weight of a mixture of 17.0% by weight of styrene, 61.0% by weight of methyl methacrylate, 2.0% by weight of acrylonitrile, and 20% by weight of toluene. -Butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione as a trione and phosphite-based antioxidant 0.3 parts by weight of a 1: 1 mixture of 2,4-di-t-butylphenyl) phosphite antioxidant, 0.005 parts by weight of n-dodecyl mercaptan as molecular weight regulator and 1,1-bis (t-butyl as organic peroxide initiator The reaction mixture to which 0.02 parts by weight of peroxy) -3,3,5-trimethyl cyclohexane was added was polymerized at a temperature of 140 ° C. in a first step while being introduced into a 26 L reactor at a rate of 14 L / hr, followed by 150 in a second step. After the polymerization was carried out by heating up to a temperature of about 60%, when the polymerization conversion rate was about 60% or more, pellets were formed by removing unreacted monomers and reaction medium at a temperature of 215 ° C in a volatilization tank. A transparent copolymer was prepared.

(Property test)

The physical properties of the transparent copolymers prepared according to the Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

Chemical Resistance Test

After fixing the 3.2 mm thick bar manufactured by injection molding to a jig (curvature radius: 226.97 mm) at both ends, soybean oil was applied to the gauze and applied to the center of the specimen. It was infiltrated and left for 24 hours. After 24 hours, the surface appearance and cracks of the specimen were visually checked and the thickness change was measured and compared.

(◎: No change, O: Color change, △: Crack occurs / Surface change is serious, ×: Crack is not available due to severe crack)

Refractive index test

The pellets were melted to make a film and measured by the method of ASTM D 1298.

Transparency test

Haze and total transmittance (Tt) were measured by the method of ASTM 1003.

Hardness test

Rockwell hardness (RH) and pencil hardness were measured by the method of ASTM D 785.

Scratch resistance (scratching resistance) test

Comparison was made by measuring the method of ASTM 3363.

(◎: Excellent, O: Normal, ×: Poor)

MI test

It was measured by ASTM D 1238.

Color b test

It was measured by ASTM D 2985.

Mw (weight average molecular weight) test

The molecular weights of the polymers obtained in the examples and comparative examples were measured by aqueous GPC using an aqueous solution containing sodium sulfate (1.33 g / l) and sodium hydroxide (0.33 g / l) as the solute.

TABLE 1

Division r Example Comparative example One 2 3 4 5 6 One 2 (1) step mixture (% by weight) St 16.72 16.37 15.84 15.49 14.88 17.86 17.6 17.0 MMA 59.28 58.03 56.16 54.91 59.52 56.54 62.4 61.0 AN 4 5.6 8 9.6 5.6 5.6 0 2.0 toluene 20 20 20 20 20 20 20 20 Additives (parts by weight) Antioxidant 0.1 0.1 0.2 0.3 0.1 0.1 0.1 0.3 Molecular weight regulator 0.02 0.015 0.01 0.01 0.15 0.15 0.08 0.005 Initiator 0.02 0.02 0.015 0.015 0.02 0.02 0.02 0.02

In the table, St represents a styrene monomer, MMA represents a methyl methacrylate monomer, AN represents an acrylonitrile monomer, and (1) each value of the step mixture represents a weight percent, and each value of the additive represents (1) The parts by weight of each additive are respectively shown relative to 100 parts by weight of the step mixture.

TABLE 2

division Example Comparative example One 2 3 4 5 6 One 2 Chemical resistance ◎ ◎ ◎ ◎ ◎ ◎ × ◎ Refractive index 1.5156 1.5154 1.5155 1.5157 1.5138 1.5175 1.5120 1.5256 Haze 0.3 0.3 0.3 0.3 0.2 0.3 0.4 0.5 Tt 94.1 93.7 94.1 93.9 94.5 93.3 92.8 91.7 Hardness RH 120 125 128 130 126 124 115 123 Pencil hardness 2H 3H 3H 4H 3H 3H 1H 3H Scratch resistance ◎ ◎ ◎ ◎ ◎ ◎ O ◎ MI 14 12 10 13 10 14 17 16 Color b 0.3 0.5 0.7 0.9 0.6 0.4 0.14 2.5 Mw 120,315 134,071 140,903 142,968 129,886 138,169 100,270 138,765

As can be seen in Table 2, the transparent copolymer resins of Examples 1 to 6 prepared by the production method of the present invention was confirmed that Haze is 0.5 or less, color b value is 1.0 or less, which is very excellent in optical properties. In addition, when the refractive index is 1.514 to 1.518 and blended with ABS, a transparent resin could be prepared. In addition, it was confirmed that the pencil hardness is more than 2H, 1H of Comparative Example 1 having an AN content of 0%, and also excellent in scratch resistance. In particular, it shows that the chemical resistance is very superior to Comparative Example 1. In addition, it also shows that the color b value is very excellent compared to Comparative Example 2 having an AN content of 2% by weight. As a result, the results of Examples 1 to 6 according to the present invention show that the hardness, scratch resistance and chemical resistance, and the color b value are all superior to Comparative Examples 1 and 2 according to the conventional method.

The transparent copolymer prepared by the method for producing a transparent copolymer according to the present invention has excellent physical properties such as transparency, scratch resistance, chemical resistance, hardness, and the like, and the resin composition blended with the other copolymer is also impact resistant. , Stiffness, transparency, glossiness, etc. are all excellent.

Although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such modifications and modifications belong to the appended claims. Do. Therefore, the scope of the present invention is defined by the following claims and their equivalents.

Claims (18)

A method for producing a transparent copolymer, characterized in that the bulk polymerization is continuously carried out by adding an antioxidant, a molecular weight regulator and an organic peroxide initiator to a mixture containing a styrene monomer, an acrylate monomer and an acrylonitrile monomer. The method according to claim 1, wherein (1) 10 to 20% by weight of styrene monomer, 50 to 60% by weight of acrylate monomer, 3 to 15% by weight of acrylonitrile monomer, and 20 to 30% by weight of reaction medium are mixed. step; (2) to 100 parts by weight of the mixture of step (1),          (i) 0.01 to 1.0 parts by weight of hindered phenolic antioxidant and phosphite antioxidant;            (ii) 0.01 to 1.0 parts by weight of molecular weight modifier; And            (iii) 0.01 to 0.1 parts by weight of organic peroxide initiator Adding to prepare a reaction mixture; And (3) The reaction mixture of step (2) is polymerized in a first step at a temperature of 120 to 140 ° C. for 2 to 4 hours, and then heated in a second step to a temperature of 130 to 150 ° C. for 2 to 4 hours. During the polymerization Method for producing a transparent copolymer comprising a. The method of claim 2, The styrene-based monomer is a transparent air, characterized in that at least one selected from the group consisting of styrene, α-methylstyrene, and at least one of each carbon of the benzene nucleus styrene optionally substituted with a C ₁ to C ₅ alkyl group or halogen Process for the preparation of coalescing. The method of claim 2, wherein the acrylate-based monomer is one or more selected from the group consisting of methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, methyl methacrylate and ethyl acrylate The manufacturing method of the transparent copolymer made into. The method according to claim 2, wherein the acrylonitrile monomer is at least one member selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. The method of claim 2, wherein the reaction medium is at least one member selected from the group consisting of C ₁ to C ₃ alkyl groups or C ₆ to C ₉ aromatic hydrocarbon compounds optionally substituted with halogens. . The method according to claim 2, wherein the antioxidant is a hindered phenol-based antioxidant: phosphite-based antioxidant composition ratio of 9: 1 to 1: 5 method for producing a transparent copolymer. 3. The hindered phenolic antioxidant according to claim 2, wherein the hindered phenolic antioxidant is tetrakis methylene 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid methane, 1,3,5-tris- (4- t-butyl-3-hydroxy-2,6-dimethyl benzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, and 1,3 1, selected from the group consisting of, 5-tris- (3,5-di-t-butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) -trione It is a species or more, The manufacturing method of the transparent copolymer characterized by the above-mentioned. 8. The method of claim 7, wherein the hindered phenolic antioxidant is tetrakis methylene 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid methane, 1,3,5-tris- (4- t-butyl-3-hydroxy-2,6-dimethyl benzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, and 1,3,5- At least one member selected from the group consisting of tris- (3,5-di-t-butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) -trione The manufacturing method of the transparent copolymer characterized by the above-mentioned. 3. The transparent copolymer of claim 2, wherein the phosphite-based antioxidant is at least one selected from the group consisting of tris (2,4-t-butyl phenyl) phosphite and tris- (nonylphenyl) phosphite. Method of preparation. 8. The transparent copolymer of claim 7, wherein the phosphite antioxidant is at least one member selected from the group consisting of tris (2,4-t-butyl phenyl) phosphite and tris- (nonylphenyl) phosphite. Method of preparation. 3. The method of claim 2, wherein the molecular weight modifier is at least one member selected from the group consisting of t-dodecyl mercaptan and n-octyl mercaptan. The method of claim 2, wherein the organic peroxide initiator is 1,1-bis (t-butyl peroxy) cyclohexane, 1,1-bis (t-butyl peroxy) 2-methyl cyclohexane and 1,1-bis ( t-butyl peroxy) -3,3,5-trimethyl cyclohexane, characterized in that at least one member selected from the group consisting of. The method of claim 2, wherein the steps (1) and (2) are performed in any order. A transparent copolymer prepared by the method according to any one of claims 1 to 14. 16. The transparent copolymer of claim 15 wherein the haze is 1.0 or less, the Rockwell hardness is 120 or more and the pencil hardness is 2H or more. A blend resin composition comprising 40 to 70% by weight of the transparent copolymer of claim 15 and 30 to 60% by weight of an ABS resin. 18. The blended resin composition of claim 17, wherein the turbidity of the transparent copolymer is 1.0 or less, Rockwell hardness is 120 or more, and pencil hardness is 2H or more.