KR102009313B1

KR102009313B1 - Graft copolymer, method for preparing the copolymer and thermoplastic resin composition comprising the copolymer

Info

Publication number: KR102009313B1
Application number: KR1020150158561A
Authority: KR
Inventors: 정유성; 채주병; 박은선; 전태영; 김영민; 김종범; 김창술
Original assignee: 주식회사 엘지화학
Priority date: 2015-11-12
Filing date: 2015-11-12
Publication date: 2019-08-09
Also published as: KR20170055647A

Abstract

The present invention relates to a graft copolymer, a method for preparing the same, and a thermoplastic resin composition comprising the same, and more particularly, to a rubber-based polymer having a core-shell structure and an aromatic vinyl including a polymerized core layer including a heat resistant monomer and a crosslinking agent. Graft copolymer graft copolymer comprising a compound and a vinyl cyan compound, Graft copolymer characterized in that the core layer of the rubbery polymer is included in more than 3 to less than 21% by weight relative to the graft copolymer, It relates to a preparation method thereof and a thermoplastic resin composition comprising the same.
According to the present invention, by including a rubber-core polymer of the core-shell structure using a core containing a heat-resistant monomer, the effect of providing a graft copolymer having excellent mechanical properties and heat resistance, a method for producing the same and a thermoplastic resin composition comprising the same have.

Description

Graft copolymer, manufacturing method thereof and thermoplastic resin composition comprising the same {GRAFT COPOLYMER, METHOD FOR PREPARING THE COPOLYMER AND THERMOPLASTIC RESIN COMPOSITION COMPRISING THE COPOLYMER}

The present invention relates to a graft copolymer, a method for preparing the same, and a thermoplastic resin composition including the same, and more particularly, to include a rubber-based polymer having a core-shell structure using a core including a heat resistant monomer, thereby providing mechanical properties and heat resistance. An excellent graft copolymer, a method for preparing the same, and a thermoplastic resin composition comprising the same.

Acrylonitrile-Butadiene-Styrene (hereinafter referred to as ABS) resins may be used in automotive, electrical, and electronic applications due to the stiffness and chemical resistance of acrylonitrile, the processability of butadiene and styrene, the mechanical strength, and the beautiful appearance. It is widely used in electronic products and office equipment.

However, since the ABS resin has low heat resistance of the resin itself, there are limitations in use of components requiring heat resistance such as interior and exterior materials of automobiles. Therefore, in order to increase the heat resistance of the ABS resin, to prepare a ABS resin by including a heat-resistant monomer (α-methyl styrene, etc.) having a high glass transition temperature during grafting, or a heat-resistant copolymer polymerized ABS resin containing a heat-resistant monomer (alpha-methyl styrene-acrylonitrile copolymer, etc.) and the like have been tried, but the graft copolymer graft polymerized including a heat resistant monomer has a low reactivity of the heat resistant monomer and a decrease in polymerization stability. As a result, the polymerization rate is significantly lowered, resulting in poor productivity, resulting in a large amount of coagulated product, which in turn lowers heat resistance.

KR 2013-0029826 A

The present invention is to provide a graft copolymer excellent in mechanical properties and heat resistance by including a rubber-core polymer of the core-shell structure using a core containing a heat-resistant monomer, in order to overcome the problems of the prior art.

It is another object of the present invention to provide a method for producing the graft copolymer.

It is another object of the present invention to provide a thermoplastic resin composition containing the graft copolymer.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention is graft polymerized graft copolymer comprising a rubber-core polymer, an aromatic vinyl compound and a vinyl cyan compound of a core-shell structure comprising a polymerized core layer comprising a heat resistant monomer and a crosslinking agent. As such, the core layer of the rubbery polymer provides a graft copolymer comprising from more than 3 to less than 21% by weight relative to the graft copolymer.

In another aspect, the present invention comprises the steps of polymerizing the core layer including a heat resistant monomer and a crosslinking agent; Wrapping the core layer and polymerizing a shell layer including a conjugated diene-based compound to prepare a rubber polymer having a core-shell structure; And graft polymerization including the aromatic vinyl compound and the vinyl cyan compound in the rubbery polymer, wherein the core layer is included in an amount of more than 3 to less than 21 wt% based on the graft copolymer. Provide a method.

The present invention also provides a thermoplastic resin composition comprising the graft copolymer and the aromatic vinyl compound-vinyl cyan compound copolymer.

According to the present invention, by including a rubber-core polymer of the core-shell structure using a core containing a heat-resistant monomer, the effect of providing a graft copolymer having excellent mechanical properties and heat resistance, a method for producing the same and a thermoplastic resin composition comprising the same have.

1 is a cross-sectional view showing the polymerization form of the graft copolymer of the present invention.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention, when preparing a graft copolymer, using the core layer containing the heat-resistant monomer as a seed, to prepare the rubbery polymer itself in the core-shell structure, the aromatic vinyl compound and the vinyl cyan compound in the rubbery polymer of the core-shell structure When graft polymerization, it was confirmed that both mechanical properties and heat resistance is improved to complete the present invention.

Looking at the graft copolymer according to the present invention in detail.

The graft copolymer is a gypsum-grafted graft copolymer including a rubber-shell polymer, an aromatic vinyl compound, and a vinyl cyan compound having a core-shell structure including a polymerized core layer including a heat resistant monomer and a crosslinking agent. The core layer of the polymer is characterized in that it comprises from more than 3 to less than 21% by weight relative to the graft copolymer.

The rubbery polymer may include, for example, a polymerized core layer including a heat resistant monomer, a vinyl cyan compound, and a crosslinking agent; And surrounding the core layer may include a polymerized shell layer including a conjugated diene-based compound.

The heat resistant monomer refers to a monomer that increases heat resistance by increasing the glass transition temperature of the polymerized polymer when the heat resistant monomer is polymerized, and may be, for example, α-methyl styrene.

The heat resistant monomer may be included in 10 to 90% by weight, 30 to 80% by weight, or 60 to 80% by weight with respect to the core layer, there is an excellent heat resistance in this range.

The vinyl cyan compound of the core layer may be, for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile, and may be 10 to 90% by weight, 20 to 70% by weight based on the core layer. Or, it may be included in 20 to 40% by weight, high reactivity with the heat-resistant monomer within this range, there is an effect excellent mechanical properties.

For example, the core layer may be polymerized by further including a (meth) acrylic acid alkyl ester compound, and in this case, the mechanical and balance properties are excellent.

Examples of the (meth) acrylic acid alkyl ester compound include (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 ( It may be at least one selected from the group consisting of meth) acrylic acid lauryl ester, it may be included in 0 to 10% by weight, 0 to 5% by weight, or 1 to 3% by weight relative to the core layer.

The crosslinking agent serves to crosslink the core layer and the conjugated diene-based compound that is contained in the shell layer and surrounds the core layer, and may be, for example, a crosslinking agent having a functional group of 2 or more. It may be a reactive compound having two or more vinyl groups.

Examples of the crosslinking agent include polyethylene glycol dimethacrylate (ethylene glycol repeating units n = 1 to 60), polyethylene glycol diacrylate (ethylene glycol repeating units n = 1 to 60), propylene glycol dimethacrylate, 1,3 -Butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,4-butylene glycol dimethacrylate, allyl methacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimetha Selected from the group consisting of acrylate, polybisphenol A-ethylene oxide diacrylate (ethylene oxide repeating units n = 1-40), tetraethylene glycol dimethacrylate, triethylene glycol dimethacrylate and divinylbenzene It may be one or more. For example, the crosslinking agent may be included in an amount of 0.01 to 5 parts by weight, 0.01 to 1 part by weight, or 0.1 to 0.8 part by weight based on 100 parts by weight of the core layer.

For example, the core layer may have an average particle diameter of 500 to 1,200 mm 3, 600 to 1,200 mm 3, or 600 to 1,000 mm 3, and has an excellent impact strength and physical property balance within this range.

For example, the core layer may have a glass transition temperature of 110 ° C. or higher, 120 ° C. or higher, or 130 to 145 ° C., and has excellent heat resistance within this range.

For example, the core layer may be included in more than 3 to less than 21% by weight, 5 to 20% by weight, or 6 to 18% by weight with respect to the graft copolymer, and excellent impact strength and heat resistance within this range have.

The conjugated diene-based compound of the shell layer may be, for example, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1, It may be at least one selected from the group consisting of 3-pentadiene and chloroprene, and may be included in 30 to 80% by weight, 40 to 70% by weight, or 40 to 60% by weight relative to the graft copolymer, within this range In the impact strength and physical property balance is excellent effect.

The core-shell rubbery polymer may have, for example, an average particle diameter of 2,800 to 4,000 mm 3, 3,000 to 4,000 mm 3, or 3,300 to 3,800 mm 3, and has an excellent impact strength and balance of physical properties within this range.

The rubbery polymer of the core-shell structure may be included, for example, 50 to 90% by weight, 50 to 80% by weight, or 50 to 70% by weight relative to the graft copolymer, within this range impact strength and heat resistance Excellent effect.

The aromatic vinyl compound graft-polymerized to the rubbery polymer may be at least one selected from the group consisting of styrene, p-methyl styrene, o-ethyl styrene, p-ethyl styrene, and vinyl toluene. It may be included in 20 to 45% by weight, 20 to 40% by weight, or 20 to 35% by weight, and within this range there is an excellent mechanical and balance properties.

The vinyl cyan compound graft-polymerized to the rubbery polymer may be, for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile, and is 1 to 20% by weight based on the graft copolymer. , 1 to 15% by weight, or may be included in 5 to 15% by weight, there is an excellent effect of mechanical and physical properties balance within this range.

The aromatic vinyl compound and the vinyl cyan compound graft polymerized to the rubbery polymer may be included in an amount of 10 to 50% by weight, 20 to 50% by weight, or 30 to 50% by weight based on the graft copolymer, for example. Mechanical properties and physical properties balance in the excellent effect.

The graft copolymer production method according to the present invention comprises the steps of polymerizing the core layer including a heat resistant monomer and a crosslinking agent; Wrapping the core layer and polymerizing a shell layer including a conjugated diene-based compound to prepare a rubber polymer having a core-shell structure; And graft polymerization including the aromatic vinyl compound and the vinyl cyan compound in the rubbery polymer, wherein the core layer is included in an amount of more than 3 to less than 21 wt% based on the graft copolymer.

The core layer may be polymerized further including, for example, a vinyl cyan compound and a (meth) acrylic acid alkyl ester compound.

The core layer may include, for example, primary polymerization including a heat resistant monomer and a vinyl cyan compound; Secondary polymerization including a vinylcyan compound and a crosslinking agent; And a third polymerization including a vinyl cyan compound. In this case, the small-diameter polymer is polymerized during the first polymerization, and then polymerized into the large-diameter polymer through the second and third stages, thereby further improving the impact strength.

For example, the core layer may be polymerized by an emulsion polymerization method, and in this case, there is an effect of excellent mechanical properties, and is not particularly limited as long as it is a conventional emulsion polymerization method. As another example, the core layer may be in the form of a latex in which the polymerized copolymer is dispersed in water in a colloidal state.

For example, the heat resistant monomer, the vinyl cyan compound and the crosslinking agent may be added in a batch, continuous, or a mixture of batch and continuous.

The core-shell structured rubbery polymer may be polymerized by, for example, an emulsion polymerization method. In this case, there is an effect of excellent balance of physical properties, and is not particularly limited as long as it is a conventional emulsion polymerization method. As another example, the core-shell rubbery polymer may be in the form of a latex dispersed in water in a colloidal state.

For example, the conjugated diene-based compound may be added in a batch, continuous, or a mixture of batch and continuous.

The core-shell structured rubbery polymer may be prepared by further comprising an acid treatment step of stabilizing by sequentially adding an acidic aqueous solution and a basic aqueous solution after being obtained in the form of latex, in which case the average of the obtained rubbery polymer By enlarging the particle diameter there is an excellent mechanical properties.

The acidic aqueous solution may be, for example, 3 to 8% by weight of an acetic acid aqueous solution, and is added in an amount of 0.1 to 3 parts by weight, 1 to 3 parts by weight, or 1.5 to 2 parts by weight based on 100 parts by weight of the rubber polymer of the core-shell structure. The basic aqueous solution may be, for example, 5 to 10% by weight of potassium hydroxide aqueous solution, and 0.1 to 3 parts by weight, 1 to 3 parts by weight, or 1.5 based on 100 parts by weight of the rubber polymer of the core-shell structure. To 2 parts by weight.

For example, the graft copolymer may be polymerized by an emulsion polymerization method. In this case, the graft copolymer may have an excellent balance between mechanical properties and physical properties, and is not particularly limited as long as it is a conventional emulsion graft polymerization method. As another example, the graft copolymer may be in the form of a latex dispersed in water in a colloidal state.

The aromatic vinyl compound and the vinyl cyan compound introduced during the graft polymerization may be added in a batch, continuous, or a mixture of batch and continuous.

The graft copolymer is obtained in the form of a latex, for example, and then agglomerated with a metal salt flocculant; And washing and drying.

For example, the graft copolymer may have a polymerization conversion of 96% or more, 97 to 99%, or 97 to 98%.

For example, the graft copolymer may have a solid coagulation content of 0.5 wt% or less, 0.01 to 0.5 wt%, or 0.01 to 0.15 wt%.

The core layer, the rubbery polymer of the core-shell structure, and the graft copolymer may be polymerized, for example, including an emulsifier, a polymerization initiator, and a molecular weight modifier.

The emulsifier is not particularly limited as long as it is an emulsifier used in an emulsion polymerization, but for example, a fatty acid metal salt may be used, and the fatty acid may be, for example, palmitic acid, oleic acid, lauryl acid, stearic acid, and the like. It may be an alkali metal.

The thermoplastic resin composition according to the present invention is characterized by comprising the graft copolymer and the aromatic vinyl compound-vinyl cyan compound copolymer.

The thermoplastic resin composition may be, for example, a form in which the graft copolymer is dispersed in a matrix resin composed of the aromatic vinyl compound-vinyl cyan compound copolymer, in which case the impact strength and the balance of physical properties are excellent.

The aromatic vinyl compound of the aromatic vinyl compound-vinyl cyan compound copolymer may be at least one selected from the group consisting of styrene, α-methyl styrene, p-methyl styrene, o-ethyl styrene, p-ethyl styrene, and vinyl toluene, for example. And, it may be preferably α-methyl styrene, in this case there is an effect of excellent balance of heat resistance and physical properties.

For example, the aromatic vinyl compound may be included in an amount of 10 to 90 wt%, 30 to 80 wt%, or 50 to 80 wt% with respect to the aromatic vinyl compound-vinyl cyan compound copolymer, and may have heat resistance and impact strength within this range. Has an excellent effect.

The vinyl cyan compound of the aromatic vinyl compound-vinyl cyan compound copolymer may be, for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile, and the aromatic vinyl compound-vinyl cyan compound It may be included in 10 to 90% by weight, 20 to 70% by weight, or 20 to 50% by weight with respect to the coalescence, there is an excellent effect of mechanical and physical properties balance within this range.

For example, the aromatic vinyl compound-vinyl cyan compound copolymer may be polymerized by bulk polymerization, and in this case, an impact strength and heat resistance may be excellent.

For example, the aromatic vinyl compound-vinyl cyan compound copolymer may have a glass transition temperature of 120 ° C. or more, 120 to 140 ° C., or 125 to 135 ° C., and has excellent heat resistance within this range.

For example, the aromatic vinyl compound-vinyl cyan compound copolymer may have a weight average molecular weight of 50,000 to 200,000 g / mol, or 80,000 to 150,000 g / mol, and has excellent mechanical properties within this range.

For example, the graft copolymer may be included in an amount of 10 to 50 wt%, 10 to 40 wt%, or 15 to 40 wt% with respect to the thermoplastic resin composition, and the aromatic vinyl compound-vinyl cyan compound copolymer may be used as an example. It may be included in 50 to 90% by weight, 60 to 90% by weight, or 60 to 85% by weight with respect to the thermoplastic resin composition, there is an excellent effect of heat resistance, mechanical properties and physical properties within this range.

The thermoplastic resin composition may further include additives such as heat stabilizers, light stabilizers, antioxidants, antistatic agents, antibacterial agents, or lubricants, for example, in a range that does not affect the physical properties.

For example, the thermoplastic resin composition may have an impact strength of 13.5 kgf · cm / cm or more, 13.5 to 18 kgf · cm / cm, or 15 to 16.5 kgf · cm / cm.

For example, the thermoplastic resin composition may have a heat deformation temperature of 100 ° C. or more, 100 to 110 ° C., or 101 to 105 ° C.

Hereinafter, preferred examples are provided to aid in understanding the present invention, but the following examples are merely for exemplifying the present invention, and various changes and modifications within the scope and spirit of the present invention are apparent to those skilled in the art. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

Example 1

Core Layer Preparation (Step a-1)

In a nitrogen-filled polymerization reactor, 150 parts by weight of ion-exchanged water, 71 parts by weight of α-methyl styrene, 10 parts by weight of acrylonitrile, 2.5 parts by weight of fatty acid potassium as an emulsifier, 0.05 parts by weight of potassium carbonate as an electrolyte, and a third degree with a molecular weight regulator 0.45 parts by weight of dodecyl mercaptan (TDDM) was mixed and stirred at 50 ° C. for 30 minutes, followed by 0.02 parts by weight of t-butyl hydroperoxide, 0.035 parts by weight of dextrose, 0.06 parts by weight of sodium pyrolate and ferrous sulfate 0.0015 The oxidation-reduction catalyst composed of parts by weight was added all at once, and the first polymerization was carried out while raising the temperature to 70 ° C for 1 hour. Subsequently, the secondary polymerization was carried out by continuously adding an emulsion composed of 30 parts by weight of ion-exchanged water, 15 parts by weight of acrylonitrile, 1 part by weight of fatty acid potassium and 0.3 part by weight of allyl methacrylate, simultaneously raising the temperature to 75 ° C for 2 hours. . Thereafter, 4 parts by weight of acrylonitrile was added together with an oxidation-reduction catalyst composed of 0.03 part by weight of t-butyl hydroperoxide, 0.035 part by weight of dextrose, 0.06 part by weight of sodium pyrolate and 0.0015 part by weight of ferrous sulfate, and 80 After the temperature was raised to 占 폚, the reaction was terminated at a polymerization conversion rate of 97% to obtain a core layer latex. The average particle diameter and glass transition temperature of the prepared core layer copolymer are shown in Table 1 below.

Preparation of rubber-core polymer of core-shell structure (b-1 step)

In a nitrogen-filled polymerization reactor, 130 parts by weight of ion-exchanged water, 10 parts by weight of the core layer latex obtained in step a-1 (based on solids), 50 parts by weight of butadiene, 2.0 parts by weight of fatty acid potassium as an emulsifier, and potassium carbonate as an electrolyte 0.3 weight part, 0.1 weight part of tertiary dodecyl mercaptan (TDDM) as a molecular weight modifier, 0.1 weight part of t-butyl hydroperoxides as an initiator, 0.025 weight part of dextrose, 0.05 weight part of sodium pyrrolylate, and 0.0005 weight part of ferrous sulfate After the batch was added and reacted at a polymerization conversion rate of 30 to 40% at the reaction temperature of 60 ° C, 40 parts by weight of butadiene was continuously added for 10 hours, the temperature was raised to 80 ° C, and the reaction was terminated at the polymerization conversion rate of 98%. A rubbery polymer latex of the structure was prepared. Subsequently, 100 parts by weight (based on solids) of the obtained rubbery polymer latex was added to another reactor to adjust the stirring speed to 60 RPM, and then 1.7 parts by weight of a 5% by weight aqueous acetic acid solution was slowly added and stirred for 30 minutes, and then 7 parts by weight. A rubbery polymer latex was finally prepared through an acid treatment step in which 1.6 parts by weight of% potassium hydroxide aqueous solution was added at the same time with stirring for 10 minutes to stabilize. The average particle diameters before the acid treatment step and the average particle diameters after the acid treatment step of the rubber polymer of the core-shell structure prepared at this time are described in Table 1 below.

Graft Copolymer Preparation (Step c-1)

In a nitrogen-filled polymerization reactor, 60 parts by weight (based on solids) of the rubbery polymer latex prepared in step b-1, 7.5 parts by weight of styrene, 2.5 parts by weight of acrylonitrile, 90 parts by weight of ion-exchanged water, and 0.3 parts by weight of potassium rosinate In addition, 0.1 weight part of sodium ethylenediamine tetraacetate, 0.005 weight part of ferrous sulfate, and 9.23 weight part of formaldehyde sodium sulfoxylate were thrown together, and it heated up at 70 degreeC. Subsequently, 10 parts by weight of ion-exchanged water, 0.3 parts by weight of potassium rosinate, 22.5 parts by weight of styrene, 7.5 parts by weight of acrylonitrile, 0.4 parts by weight of tertiary dodecyl mercaptan (TDDM) and 0.4 parts by weight of diisopropylenebenzenehydroperoxide After the negative mixed emulsion solution was continuously added for 3 hours, the polymerization temperature was again raised to 80 ° C., and then aged for 1 hour to terminate the reaction. At this time, the polymerization conversion rate and the solidified solid content of the graft copolymer are shown in Table 1 below. Thereafter, 2.5 parts by weight of 23% by weight aqueous magnesium sulfate solution was added to aggregate, washed, and dried to obtain a graft copolymer powder.

Manufacture of thermoplastic resin composition ( manufacture of d-1)

27 parts by weight of the graft copolymer powder obtained in step c-1 and 73 parts by weight of α-methyl styrene-acrylonitrile copolymer (manufactured by LG Chem, product name 100 UH) prepared by bulk polymerization were mixed in a conventional mixer. Then, the pellets were melted and kneaded at 240 to 250 ° C. using an extruder, and then pellets were prepared for measuring physical properties using an injection machine.

Example 2

In the step b-1 of Example 1, except that 1.7 parts by weight of 5% by weight aqueous solution of acetic acid and 1.9 parts by weight instead of 1.6 parts by weight of 7% by weight aqueous potassium hydroxide solution was added to the acid treatment step was carried out. It carried out by the same method as Example 1.

Example 3

In step a-1 of Example 1, instead of 71 parts by weight of α-methyl styrene and 10 parts by weight of acrylonitrile, instead of 71 parts by weight of α-methyl styrene and 8 parts by weight of acrylonitrile and methyl, 2 parts by weight of methacrylate was added to obtain a core layer latex, and in the step b-1 of the above example, 30 parts by weight of the obtained core layer latex (based on solids) and butadiene as the core layer latex and monomer to be added before the start of the reaction Except that 30 parts by weight was carried out in the same manner as in Example 1.

Comparative Example 1

In the step a-1 of Example 1, it was carried out in the same manner as in Example 1 except that allyl methacrylate was not added.

Comparative Example 2

In step a-1 of Example 1, 71 parts by weight of styrene is added instead of 71 parts by weight of α-methyl styrene, and in step b-1 of the above example, the obtained core is substituted for the core layer latex obtained in step a-1. Same amount as in Example 1 except that the same amount of the layer latex was added, 1.8 parts by weight instead of 1.7 parts by weight of 5% by weight aqueous acetic acid solution and 1.8 parts by weight instead of 1.6 parts by weight of 7% by weight aqueous potassium hydroxide solution. It was carried out by the method.

Comparative Example 3

In step b-1 of Example 1, 5 parts by weight of the core layer latex (based on solids) and 55 parts by weight of butadiene were added instead of 10 parts by weight of the core layer latex (based on solids) and 50 parts by weight of butadiene before the start of the reaction. Except that was carried out in the same manner as in Example 1.

Comparative Example 4

In step b-1 of Example 1, 35 parts by weight of the core layer latex (based on solids) and 25 parts by weight of butadiene are added instead of 10 parts by weight of the core layer latex (based on solids) and 50 parts by weight of butadiene, which are added before the start of the reaction. It was carried out in the same manner as in Example 1 except that the acid treatment step was carried out by adding 1.9 parts by weight instead of 1.7 parts by weight of 5% by weight aqueous acetic acid solution and 1.6 parts by weight of 7% by weight aqueous potassium hydroxide solution.

Comparative Example 5

In the step b-1 of Example 1, it was carried out in the same manner as in Example 1, except that 60 parts by weight of butadiene was added instead of 50 parts by weight of butadiene added before the start of the reaction, the core layer latex.

[Test Example]

The physical properties of the core layers, the rubbery polymer of the core-shell structure, the graft copolymer, and the thermoplastic resin composition of Examples 1 to 3 and Comparative Examples 1 to 5 were measured by the following methods, and the results were respectively described below. Table 1 shows.

How to measure

* Average particle size: Measured by dynamic light scattering method using Submicron Particle Sizer, NICOMP 380 instrument of PPS (Particle Sizing Systems).

* Glass transition temperature (Tg, ℃): Measured while raising the temperature at a temperature rising rate of 10 ℃ / min using DSC1 Star System of METTELR TOLEDO.

* Polymerization Conversion Rate (%): 1.5 g of the graft copolymer latex was dried in a 150 ° C. hot air dryer for 15 minutes, and then weighed to obtain a total solid content (TSC), and the polymerization conversion rate was calculated by the following Equation 1.

TSC: Total solids content (parts by weight)

M: total monomer content added (parts by weight)

W: input water content (parts by weight)

S: content of the added emulsifier and other auxiliary raw materials (parts by weight)

* Solid coagulant (% by weight): The weight of the coagulum produced in the reaction tank, the weight of the total rubber and the monomer weight were measured, and the coagulum content was calculated by the following Equation 2.

* Impact Strength (Notched Izod, kgf · cm / cm): Measured according to standard measurement ASTM D256 using a 1/4 "specimen.

* Heat deflection temperature (HDT, ℃): was measured according to the standard measurement ASTM D648 using a 1/4 "specimen.

division Example Comparative example One 2 3 One 2 3 4 5 Core layer Average particle diameter 600 600 1,000 600 400 600 600 - Glass transition temperature 135 135 139 135 102 135 135 - Rubbery polymer Average particle diameter before acid treatment 1,200 1,200 1,500 800 700 1,200 700 1,200 Average particle size after acid treatment 3,400 3,800 3,300 3,300 3,100 3,200 2,200 3,400 Graft copolymer Polymerization conversion 98 97.2 97.8 98.1 98.4 97.5 96.2 97.4 Solid coagulant 0.09 0.05 0.12 0.77 0.30 0.07 0.17 0.05 Impact strength 15.7 16.5 15.0 12.3 13.4 15.9 9.3 16.7 Heat deflection temperature 101.9 102.1 104.0 101.0 100.5 100.6 103.9 99.9

As shown in Table 1, in Examples 1 and 3 prepared according to the present invention, the polymerization stability of the graft copolymer is excellent, there is little solid coagulation, it is confirmed that the productivity is excellent, both the impact strength and heat resistance is excellent Could.

On the other hand, in Comparative Example 1, which does not include a crosslinking agent in the core layer, crosslinking is not well achieved in the shell layer, so that the average particle diameter before the acid treatment is small, thereby increasing the content of solidified solids, and thus the impact strength is very poor, and the heat resistance is high. Also it could be confirmed that not significantly improved. In addition, in the case of Comparative Example 2 including styrene, which is not a heat resistant monomer when preparing the core layer, it was confirmed that the glass transition temperature of the core layer was very low, and the impact strength and heat resistance were very poor.

In addition, in the case of Comparative Example 3 containing a small amount of the core layer, it was confirmed that the polymerization stability is reduced and the heat resistance improvement effect is insignificant. In Comparative Example 4, which contains the core layer in an excessive amount, the polymerization stability is lowered and the impact strength is reduced. It was confirmed that remarkably decreased.

In addition, in the case of Comparative Example 5 in which the rubbery polymer was produced by including only the butadiene monomer without including the core layer, it was confirmed that the heat resistance was very poor.

From this, the present inventors prepared the rubbery polymer itself into a core-shell structure using the core layer containing the heat resistant monomer as a seed from the above results, and the aromatic vinyl compound and the vinyl cyan in the rubbery polymer of the core-shell structure. When graft polymerization of the compound, it was confirmed that the graft copolymer with improved mechanical properties and heat resistance can be realized.

Claims

A core layer polymerized including a heat resistant monomer, a vinyl cyan compound and a crosslinking agent, and having a glass transition temperature of 110 ° C. or higher; And a graft copolymer including a core-shell structured rubbery polymer, an aromatic vinyl compound, and a vinyl cyan compound, including a shell layer polymerizing the core layer and including a conjugated diene-based compound.
The core layer of the rubbery polymer is included in more than 3 to less than 21% by weight relative to the graft copolymer,
The graft copolymer is a graft copolymer, characterized in that the solidified content of 0.01 to 0.15% by weight.

delete

The method of claim 1,
The core layer is a graft copolymer, characterized in that the average particle diameter of 500 to 1,200 mm 3.

delete

The method of claim 1,
The vinyl cyan compound of the core layer is a graft copolymer, characterized in that at least one member selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile.

The method of claim 1,
The conjugated diene compound of the shell layer is 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3- Graft copolymer, characterized in that at least one member selected from the group consisting of pentadiene and chloroprene.

The method of claim 1,
The shell layer is a graft copolymer, characterized in that contained in 30 to 80% by weight relative to the graft copolymer.

The method of claim 1,
The rubbery polymer is a graft copolymer, characterized in that the average particle diameter of 2,800 to 4,000 kPa.

The method of claim 1,
The aromatic vinyl compound is a graft copolymer, characterized in that at least one member selected from the group consisting of styrene, o-ethyl styrene, p-ethyl styrene and vinyl toluene.

The method of claim 1,
A graft copolymer, characterized in that the aromatic vinyl compound and the vinyl cyan compound graft polymerized in the rubber polymer is included in 10 to 50% by weight relative to the graft copolymer.

Polymerizing the core layer including a heat resistant monomer, a vinyl cyan compound and a crosslinking agent;
Preparing a rubber polymer having a core-shell structure by surrounding the core layer and polymerizing a shell layer including a conjugated diene-based compound; And
Graft polymerization comprising an aromatic vinyl compound and a vinyl cyan compound in the rubbery polymer;
The core layer is included in more than 3 to less than 21% by weight relative to the graft copolymer, the glass transition temperature is 110 ℃ or more,
The graft copolymer is a graft copolymer production method, characterized in that the solidified content of 0.01 to 0.15% by weight.

delete

The method of claim 11,
The core layer, the first polymerization comprising a heat-resistant monomer and a vinyl cyan compound; Secondary polymerization including a vinylcyan compound and a crosslinking agent; And a third polymerization step including a vinyl cyan compound.

A thermoplastic resin composition comprising the graft copolymer according to any one of claims 1, 3 and 5 to 10 and an aromatic vinyl compound-vinyl cyan compound copolymer.

The method of claim 14,
The aromatic vinyl compound of the aromatic vinyl compound-vinyl cyan compound copolymer is at least one member selected from the group consisting of styrene, α-methyl styrene, o-ethyl styrene, p-ethyl styrene and vinyltoluene.

The method of claim 14,
The aromatic vinyl compound-vinyl cyan compound copolymer is polymerized by bulk polymerization.

The method of claim 14,
The aromatic vinyl compound-vinyl cyan compound copolymer has a glass transition temperature of 120 ° C. or more.

The method of claim 14,
The graft copolymer is contained in 10 to 50% by weight, the aromatic vinyl compound-vinyl cyan compound copolymer is characterized in that the thermoplastic resin composition is contained in 50 to 90% by weight.

The method of claim 14,
The thermoplastic resin composition is a thermoplastic resin composition, characterized in that the impact strength of 13.5 kgf · cm / cm or more.

The method of claim 14,
The thermoplastic resin composition is a thermoplastic resin composition, characterized in that the heat deformation temperature is 100 ℃ or more.