WO2014208965A1 - Method for preparing thermoplastic resin composition with remarkable surface clearness and gloss - Google Patents

Abstract

The present invention relates to a method for preparing a thermoplastic resin composition having remarkable surface clearness and gloss and capable of preventing mold deposits during a high speed injection process, by: preparing a resin latex by using a reactive emulsifier during emulsification polymerization of a rubber latex comprising polybutadiene and using a hydrophobic initiator during graft copolymerization of the rubber latex, an aromatic vinyl monomer and a vinyl cyano monomer; aggregating the resin latex; compression hydrating the same to have a water content of less than 10% by using a compression dehydrator; and carrying out a wet powder extrusion process. The method comprises: (1) a rubber latex preparation step of preparing a rubber latex from a conjugated diene monomer by using a reactive emulsifier; (2) a resin latex preparation step of preparing a resin latex by graft copolymerizing an aromatic vinyl monomer and a vinyl cyano monomer to the rubber latex by using a reactive emulsifier and a hydrophobic initiator; (3) a dehydration step of aggregating the resin latex, and obtaining a wet powder by mechanically dehydrating the aggregated product to have a water content of 2-15%; and (4) a wet coextrusion step of preparing a pellet by wet coextruding the wet powder with an aromatic vinyl-vinyl cyano copolymer.

Description

Method for producing a thermoplastic resin composition excellent in surface sharpness and gloss

The present invention relates to a method for producing a thermoplastic resin composition having excellent surface clarity and glossiness, and more particularly, using a reactive emulsifier in the emulsion polymerization of rubber latex made of polybutadiene, and also using a rubber latex, an aromatic vinyl monomer, and vinyl. In the graft copolymerization of cyan monomer, a resin latex is prepared using a hydrophobic initiator, the resin latex is agglomerated, and then compressed and dewatered to have a moisture content of less than 10% using a compression dehydrator, and wet powder extrusion. The present invention relates to a method for producing an excellent thermoplastic resin composition having excellent surface sharpness and glossiness through a process, and capable of preventing mold deposit during high-speed injection processing.

Acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as 'ABS resin') has excellent mechanical properties, chemical resistance, excellent colorability and workability, and is suitable for interior and exterior parts of electric and electronic products, automobiles and small toys. It is widely used in furniture, furniture and building materials. In the manufacturing method of ABS resin, butadiene monomer is polymerized by emulsion polymerization to make polybutadiene rubber latex, and the polybutadiene rubber latex is graft copolymerized with aromatic vinyl monomer and vinyl cyan monomer to make resin latex, and the resin latex is aggregated. After dehydration, it is dewatered with a dehydrator and dried with a dryer, whereby ABS resin is usually obtained in the form of pellets. The pellet-form ABS resin thus obtained is processed into a desired form through extrusion processing and / or injection molding process together with styrene-acrylonitrile copolymer resin (hereinafter referred to as SAN resin) prepared by solution polymerization. Used.

However, most of ABS resin manufacturing method is made by emulsion polymerization method using general emulsifier such as rosin or faty, and after polymerization, residual emulsifier, impurities such as electrolyte, residual monomer, etc. In high-speed injection processing, there is a limit in surface sharpness and gloss due to gas generation, and there are problems such as mold precipitation.

Therefore, in order to improve such a problem, a method of manufacturing the ABS resin by the bulk polymerization method is also used in part, but the ABS resin produced by the bulk polymerization method has a low gloss and has a limitation in obtaining a high impact thermoplastic resin. There was this.

In recent years, efforts to implement high-quality home appliances and various designs, such as smart TVs and air conditioners, have been intensifying, and there is a great demand for the development of materials suitable for such efforts, and high-speed injection processing for mass production during injection processing. In the city, there is a demand for developing a material having excellent thermal stability and preventing mold precipitation, and developing a low-emission environment-friendly material.

Therefore, one object of the present invention is to focus on the fact that the cause of surface sharpness inhibition and mold precipitation is mainly due to the use of rosin or fatty emulsifier, so that a small amount of gas is generated at high temperature, in particular during extrusion and / or injection molding. Reaction of rosin or fatty emulsifier in preparation of polybutadiene rubber latex by emulsion polymerization method and graft copolymerization of polybutadiene rubber latex with aromatic vinyl monomer and vinyl cyan monomer It is providing the manufacturing method of the thermoplastic resin composition which is excellent in surface sharpness and without mold precipitation by superposing | polymerizing using a type | mold emulsifier.

Another object of the present invention is the inner grafting of the aromatic vinyl monomer and vinyl cyan monomer to polybutadiene rubber latex by using a hydrophobic initiator in the graft copolymerization reaction (aromatic vinyl monomer and vinyl cyan monomer) Swelling and grafting into the polybutadiene rubber latex to prevent rubber distortion due to high shear during high-speed injection processing and injection retention glossiness It is to provide an excellent method for producing a thermoplastic resin composition.

Another object of the present invention is to agglomerate the obtained graft copolymer latex, and then dehydration by increasing the dehydration rate by lowering the moisture content of the wet powder to less than 10% by using a compression dehydrator during dehydration. It is to provide a method for producing a thermoplastic resin composition which can minimize the impurity content to reduce the thermal stability of the resin finally obtained by allowing the impurities in the resin latex to be discharged with water as much as possible.

Another object of the present invention is extrusion kneading together with the styrene-acrylonitrile copolymer resin prepared by bulk polymerization or solution polymerization of the wet powder of the resin latex having a moisture content of less than 10%, the wet coextrusion method during extrusion Impurity that can cause surface sharpness, thermal stability, and mold precipitation by applying wet powder extrusion process to remove unreacted monomers and oligomers by azeotropic phenomenon along with volatilization of water by vacuum applied during wet coextrusion. It is to provide a method for producing a thermoplastic resin composition that can minimize the.

In order to achieve the above object, the present invention comprises the steps of (1) preparing a rubber latex from the conjugated diene monomer using a reactive emulsifier; (2) graft copolymerizing an aromatic vinyl monomer and a vinyl cyan monomer to the rubber latex using a hydrophobic initiator to prepare a graft resin latex; (3) aggregating and then dehydrating the graft resin latex to obtain a wet powder; And (4) wet coextruding the wet powder together with the aromatic vinyl-vinyl cyan copolymer to provide an extrudate.

In the step (2), for example, a reactive emulsifier may be used during graft copolymerization.

Dehydration of step (3) may be carried out by a compression dewatering method as an example.

The wet powder of step (3) may be, for example, a water content of 2 to 15% by weight.

The wet coextrusion of step (4) may be carried out under vacuum decompression conditions as an example.

The wet coextrusion may be carried out under vacuum decompression conditions of, for example, 1 to 760 torr.

The wet coextrusion of step (4) may include, for example, a water evaporation process.

In the wet coextrusion of step (4), for example, the wet powder may be added first, followed by the aromatic-vinyl cyan copolymer.

In step (4), for example, wet coextrusion of step (4) may be continuously performed without a drying process after the dehydration of step (3).

In addition, the present invention provides a thermoplastic resin composition, which is prepared by the method for producing the thermoplastic resin composition.

In addition, the method for producing a thermoplastic resin composition having excellent surface clarity and glossiness according to the present invention comprises: (1) preparing a rubber latex from a conjugated diene monomer using a reactive emulsifier; (2) preparing a resin latex by graft copolymerizing an aromatic vinyl monomer and a vinyl cyan monomer on the rubber latex using a reactive emulsifier and a hydrophobic initiator; (3) after the resin latex is aggregated, a dehydration step of mechanically dehydrating a moisture content of 2 to 15% to obtain a wet powder; And (4) a wet coextrusion step of wet coextruding the wet powder together with the aromatic vinyl-vinyl cyan copolymer to prepare pellets.

In addition, the method for producing a thermoplastic resin composition having excellent surface clarity and glossiness according to the present invention, (1) rubber latex for preparing a rubber latex using 1.0 to 3.0 parts by weight of a reactive emulsifier based on 100 parts by weight of a conjugated diene monomer Manufacturing step; (2) 18 to 40% by weight of an aromatic vinyl monomer, 8 to 18% by weight of a vinyl cyan monomer, 0.1 to 0.7% by weight of a reactive emulsifier, 0.1 to 0.4% by weight of a hydrophobic initiator, and a balance to obtain the resulting rubber latex. Resin latex manufacturing step of producing a resin latex of the graft copolymer by emulsion polymerization of the reaction mixture; (3) after agglomerating the resin latex, dehydrating to obtain a wet powder by dehydration to a water content of 2 to 15%; And (4) wet coextrusion of the wet powder with the aromatic vinyl-vinyl cyan copolymer, and wet coextrusion to wet coextrude so that the rubber content of the final resin is within the range of 10 to 30% by weight. Can be.

Examples of the reactive emulsifier include anionic and neutral polymeric emulsifiers having an allyl group, anionic and neutral polymeric emulsifiers having a (meth) acryloyl group, anionic or neutral polymeric emulsifiers having a propenyl group, and among these Reactive emulsifiers selected from the group consisting of two or more mixtures can be used.

The rubber latex manufacturing step may further include a gel content adjusting agent in an amount within the range of 0.1 to 1.0 parts by weight.

The gel content adjusting agent is ethyl-2-mercaptoethylpropionate, 2-mercaptoethylpropionate, 2-mercaptoethanol, mercaptoacetic acid, n-octyl mercaptan, n-dodecyl mercaptan, t- It may be selected from the group consisting of dodecyl mercaptan and a mixture of two or more thereof.

The conjugated diene monomer may be selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, pyrrylene and mixtures of two or more thereof.

The rubber latex may have a swelling index of 5 to 25 or less.

The rubber latex may have an average particle diameter within the range of 2500 to 3800 mm 3.

The rubber latex may have a gel content within the range of 70 to 95%.

The resin latex manufacturing step may further comprise 0.1 to 0.4% by weight of a molecular weight regulator.

The molecular weight modifier used in the step of preparing the resin latex is ethyl-2-mercaptoethylpropionate, 2-mercaptoethylpropionate, 2-mercaptoethanol, mercaptoacetic acid, n-octyl mercaptan, n- It may be selected from the group consisting of dodecyl mercaptan, t-dodecyl mercaptan and a mixture of two or more thereof.

The aromatic vinyl monomer used in the resin latex manufacturing step is styrene, alpha-methyl styrene (α-methyl styrene), para-methyl styrene (p-methyl styrene), vinyl toluene, tert-butyl styrene (t-butyl styrene) ), Chlorostyrene, substituents thereof, and mixtures of two or more thereof.

The vinyl cyan monomer used in the resin latex manufacturing step may be selected from the group consisting of acronitrile, methacrylonitrile, substituents thereof, and mixtures of two or more thereof.

The hydrophobic initiator used in the resin latex manufacturing step is a fat-soluble peroxide initiator cumene hydroperoxide, diisopropylbenzene hydroperoxide, tertiary butyl hydroperoxide, paramethane hydroperoxide, benzoyl peroxide; Metal salts selected from the group consisting of iron (II), iron (III), cobalt (II) or cerium (IV) and mixtures of two or more thereof as metal salts as redox-based polymerization initiators, dextrose as a reducing agent, Glucose, fructose, dihydroxyacetone, polyamine, or a reducing agent selected from the group consisting of two or more thereof.

The molecular weight of the resin latex may be in the range of 50,000 to 150,000 as a weight average molecular weight.

The resin latex agglomerated as described above may be mechanically dehydrated to obtain a wet powder having a water content of 2 to 15% by weight, preferably 2 to 12% by weight, more preferably 5 to 10% by weight, in this range. Along with the volatilization of water there is an effect that the unreacted monomers, oligomers, etc. are effectively removed by azeotropy.

Dehydration as described above may be carried out by mechanical pressurization, preferably by dehydration with a centrifugal dehydrator, and then again with dehydration with a pressurized dehydrator.

The wet coextrusion may be performed by co-extruding the wet powder of the resin latex and the aromatic vinyl-vinyl cyan copolymer while reducing the pressure in the coextruder to a pressure below atmospheric pressure.

The wet coextrusion may be performed by dividing the wet powder of the resin latex into the coextruder and then adding the aromatic vinyl-vinyl cyan copolymer, before and after the addition of the aromatic vinyl-vinyl cyan copolymer. Co-extrusion of the wet powder of the resin latex and the aromatic vinyl-vinyl cyan copolymer while reducing the pressure in the coextruder to a pressure below atmospheric pressure.

The thermoplastic resin composition prepared according to the method for preparing a thermoplastic resin composition having excellent surface sharpness and glossiness according to the present invention uses a reactive emulsifier during the emulsion polymerization of rubber latex made of polybutadiene, and also includes a rubber latex, an aromatic vinyl monomer, When graft copolymerization of vinyl cyan monomer, a resin latex is prepared by using a hydrophobic initiator, the resin latex is agglomerated, and then compressed and dewatered to have a moisture content of less than 10% using a compressive dehydrator, and wet powder (wet powder). It has an excellent surface sharpness and glossiness through an extrusion process, and has an advantage of preventing mold deposit during high-speed injection processing.

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

Method for producing a thermoplastic resin composition excellent in surface sharpness and glossiness according to the present invention, (1) rubber latex manufacturing step of producing a rubber latex from a conjugated diene monomer using a reactive emulsifier; (2) preparing a resin latex by graft copolymerizing an aromatic vinyl monomer and a vinyl cyan monomer on the rubber latex using a reactive emulsifier and a hydrophobic initiator; (3) after the resin latex is aggregated, a dehydration step of mechanically dehydrating a moisture content of 2 to 15% to obtain a wet powder; And (4) a wet coextrusion step of wet coextruding the wet powder together with the aromatic vinyl-vinyl cyan copolymer to produce pellets.

More specifically, the method for producing a thermoplastic resin composition having excellent surface clarity and glossiness according to the present invention comprises (1) preparing a rubber latex using 1.0 to 3.0 parts by weight of a reactive emulsifier based on 100 parts by weight of a conjugated diene monomer. Rubber latex manufacturing step; (2) 18 to 40% by weight of an aromatic vinyl monomer, 8 to 18% by weight of a vinyl cyan monomer, 0.1 to 0.7% by weight of a reactive emulsifier, 0.1 to 0.4% by weight of a hydrophobic initiator, and a balance to obtain the resulting rubber latex. Resin latex manufacturing step of producing a resin latex of the graft copolymer by emulsion polymerization of the reaction mixture; (3) after the resin latex is aggregated, a dehydration step of mechanically dehydrating a moisture content of 2 to 15% to obtain a wet powder; And (4) wet coextrusion of the wet powder with an aromatic vinyl-vinyl cyan copolymer, and wet coextrusion to wet coextrude so that the rubber content of the final resin is within the range of 10 to 30% by weight. Characterized in that made.

Examples of the reactive emulsifier include anionic and neutral polymeric emulsifiers having an allyl group, anionic and neutral polymeric emulsifiers having a (meth) acryloyl group, anionic or neutral polymeric emulsifiers having a propenyl group, and among these Reactive emulsifiers selected from the group consisting of two or more mixtures can be used. Reactive emulsifier in the present invention means an emulsifier having the ability to chemically bond in the polymerization (polymerization).

The anionic emulsifier having an allyl group includes a sulfate salt of polyoxyethylene allyl glycidyl nonylphenyl ether, and the neutral emulsifier having an allyl group includes polyoxyethylene allyl glycidyl nonylphenyl ether. The sulfate salt of the polyoxyethylene allyl glycidyl nonylphenyl ether may be the trade name ADEKARIA SOAP SE of Asahi Denka of Japan. In addition, the polyoxyethylene allyl glycidyl nonylphenyl ether may be the trade name ADEKARIA SOAP NE of Asahi Denka Co., Ltd., Japan.

Useful in the market as an anionic emulsifier having a (meth) acryloyl group is the product name ELEMINOL RS of Sanyo Kasei of Japan, and a neutral emulsifier of Nippon Surfactant of Japan Trade name RMA-560. Polymeric emulsifiers include UM and UX by Toagosei Co., Ltd., Japan. As an anionic emulsifier which has a propenyl group, the ammonium sulfate salt of polyoxyethylene allyl glycidyl nonyl propenyl phenyl ether is typical, and what is useful in the market is Daiichi Kogyo Seiyaku of Japan. Product name AQUARON HS and product name LATEMUL of Kao Corporation in Japan, and AQUARON BC of Daiichi Kogyo Seiyaku Co., Ltd. in Japan. Such reactive emulsifiers are preferably anionic emulsifiers. Neutral emulsifiers have a disadvantage in that the reaction time is increased due to less particles, and latex stability is lower than that of anionic emulsifiers. These reactive emulsifiers may be used alone or in admixture of two or more thereof.

The reactive emulsifiers are, for example, sulfoethyl methacrylate (SEM), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), sodium styrene sulfonate Salt (sodium styrene sulfonate; NaSS), sodium dodecyl allyl sulfosuccinate (trade name TREM LF-40), copolymer of styrene and sodium dodecylallylsulfosuccinate, polyoxyethylene alkylphenyl ether ammonium sulfate ( polyoxyethylene alkylphenyl ether ammonium sulfate; trade name HITENOL-BC, HITENOL-KH, C16-18 alkenyl succinic acid di-potassium salt; trade name Latemul ASK, ELOPLA AS100 series, methalylsulphate It may be selected from the group consisting of sodium methallyl sulfonate (SMAS) and a mixture of two or more thereof.

In the rubber latex manufacturing step, the reactive emulsifier may be used within 1.0 to 3.0 parts by weight, preferably 1.0 to 2.0 parts by weight, more preferably 1.2 to 1.8 parts by weight based on 100 parts by weight of the conjugated diene monomer. The use of the above-mentioned reactive emulsifier within this range is excellent in obtaining a thermoplastic resin having excellent surface sharpness and no mold precipitation.

In the rubber latex manufacturing step, 50 to 100 parts by weight of the conjugated diene monomer before the start of polymerization in a batch and polymerized for 5 to 15 hours, the remaining conjugated diene monomer is administered in a batch or sequentially administered The polymerization can be carried out for 10 to 20 hours. In this case, the total amount of the reactive emulsifier is preferably 2.0 parts by weight or less by adding the reactive emulsifier at the beginning of the reaction to improve the stability of the rubber latex. In this case, the reactive emulsifier is preferably an anionic reactive emulsifier, and when the conjugated diene monomer is added in the middle, the reactive emulsifier may be administered in combination with the reactive emulsifier alone or a non-reactive emulsifier. The rubber latex thus produced can minimize the amount of residual impurities, and thus can provide excellent surface sharpness and gloss when ABS resin is applied.

In the rubber latex manufacturing step, the gel content adjusting agent is further added in an amount within the range of 0.1 to 1.0 parts by weight, preferably 0.1 to 0.6 parts by weight, more preferably 0.2 to 0.4 parts by weight based on 100 parts by weight of the conjugated diene monomer. What is included is preferred for obtaining rubber latex having an average particle diameter of 2500 to 3800 mm 3 and a gel content within the range of 70 to 95%. The gel content regulator is preferably mercaptans, and has excellent volatility, ethyl-2-mercaptoethylpropionate, 2-mercaptoethylpropionate, 2-mercaptoethanol, mercaptoacetic acid, n-octyl mercaptan , n-dodecyl mercaptan, t-dodecyl mercaptan and a mixture of two or more thereof.

The conjugated diene monomer may be selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, pyrrylene and mixtures of two or more thereof. The conjugated diene monomer may be used together with an ethylenically unsaturated monomer, and the ethylenically unsaturated monomer is preferably a group consisting of aromatic vinyl monomers, vinyl cyan monomers and mixtures thereof used in the preparation of resin latex of the graft copolymer described below. May be selected from.

If it described in detail with respect to the production of the rubber latex as follows.

The present invention is 50 to 100 parts by weight of the total 100 parts by weight of the conjugated diene monomer, 1.0 to 1.5 parts by weight of the reactive emulsifier, 0.1 to 0.6 parts by weight of the polymerization initiator, 0.2 to 1.0 parts by weight of the electrolyte, 0.1 to 0.5 parts by weight of the gel content regulator, 75-100 parts by weight of ion-exchanged water was reacted at 65-75 ° C. for 5 to 15 hours, and then the remaining conjugated diene monomer was reacted with 0.1 to 0.5 parts by weight of a reactive emulsifier and 0.05 to 0.5 parts by weight of a gel content regulator. For the production of thermoplastic resins having excellent surface sharpness and glossiness by improving the stability of the latex by the polymerization reaction to be administered or sequentially administered at 70 to 85 ° C. for 10 to 20 hours so that the amount of emulsifier is not more than 2.0 parts by weight. Rubber latex can be provided.

Polymerization initiators used in the rubber latex production step include cumene hydroperoxide, diisopropylbenzene hydroperoxide, tertiary butyl hydroperoxide, paramethane hydroperoxide, benzoyl peroxide as a fat-soluble peroxide initiator; Metal salts selected from the group consisting of iron (II), iron (III), cobalt (II) or cerium (IV) and mixtures of two or more thereof as metal salts as redox-based polymerization initiators, dextrose as a reducing agent, Glucose, fructose, dihydroxyacetone, polyamine, or a reducing agent selected from the group consisting of two or more thereof. Water-soluble initiators such as persulfate may also be used.

The electrolyte is potassium chloride (KCl), sodium chloride (NaCl), potassium hydrogen carbonate (KHCO ₃ ), sodium bicarbonate (NaHCO ₃ ), sodium carbonate (Na ₂ CO ₃ ), potassium carbonate (K ₂ CO ₃ ), potassium hydrogen sulfate ( KHSO ₃ ), sodium hydrogen sulfate (NaHSO ₃ ), potassium pyrophosphate (K ₄ P ₂ O ₇ ), sodium pyrophosphate (Na ₄ P ₂ O ₇ ), potassium phosphate (K ₃ PO ₄ ), sodium phosphate (Na ₃ PO ₄ ), sodium dihydrogen phosphate (Na ₂ HPO ₄ ) and potassium dihydrogen phosphate (K ₂ HPO ₄ ) can be used to select one or more.

The rubber latex may have a swelling index of 5 to 25 or less.

The rubber latex may have an average particle diameter within the range of 2500 to 3800 mm 3.

The rubber latex may have a gel content within the range of 70 to 95%.

In the present invention, the properties and properties of the rubber latex can be measured by the following method.

1) Gel content and swelling index

The resulting rubber latex was coagulated using dilute acid or metal salt, washed, dried in a vacuum oven at 60 ° C. for 24 hours, and the resulting rubber mass was chopped with scissors, and then 1 g of rubber was placed in 100 g of toluene for 48 hours. After storage in the dark at room temperature, separated into sol and gel, and the gel content and swelling index are measured by the following equations (1) and (2).

[Equation 1]

Gel content (%) = (weight of insoluble (gel) / weight of sample) * 100

[Equation 2]

Swelling index = weight of swollen gel / weight of gel

2) particle size and particle size distribution

Nicomp 370HPL, a product name of Particle Sizing Systems, Inc., USA, was used to measure by Dynamic Light Scattering (DLS) using laser light as a light source.

In addition, the aromatic latex monomer in the resin latex step is used in an amount of 18 to 40% by weight, preferably 20 to 35% by weight, most preferably 25 to 30% by weight based on the total weight of the reaction mixture. It is preferable to be. There is little yellowing within the above range, the fluidity does not decrease, there is an effect excellent in chemical resistance and impact strength.

The vinyl cyan monomer is preferably used in an amount of 8 to 18% by weight, preferably 10 to 15% by weight, most preferably 11 to 13% by weight, based on the total weight of the reaction mixture. There is little yellowing within the above range, the fluidity does not decrease, there is an effect excellent in chemical resistance and impact strength.

The resin latex manufacturing step may be further included in the range of 0.1 to 0.4% by weight, preferably 0.2 to 0.5% by weight, most preferably 0.25 to 0.3% by weight based on the total weight of the reaction mixture, It has an advantageous molecular weight within the range, the fluidity is not lowered, there is an effect sufficient impact strength and chemical resistance.

The molecular weight modifier used in the step of preparing the resin latex is ethyl-2-mercaptoethylpropionate, 2-mercaptoethylpropionate, 2-mercaptoethanol, mercaptoacetic acid, n-octyl mercaptan, n- It may be selected from the group consisting of dodecyl mercaptan, t-dodecyl mercaptan and a mixture of two or more thereof.

The aromatic vinyl monomer used in the resin latex manufacturing step is styrene, alpha-methyl styrene (α-methyl styrene), para-methyl styrene (p-methyl styrene), vinyl toluene, tert-butyl styrene (t-butyl styrene) ), Chlorostyrene, substituents thereof, and mixtures of two or more thereof.

The vinyl cyan monomer used in the resin latex manufacturing step may be selected from the group consisting of acronitrile, methacrylonitrile, substituents thereof, and mixtures of two or more thereof.

In the step of preparing the resin latex, the reactive emulsifier is present in an amount within the range of 0.1 to 0.7% by weight, preferably 0.1 to 0.5% by weight, most preferably 0.1 to 0.3% by weight, based on the total weight of the reaction mixture. It is preferable to use, there is no coagulation within this range, high polymerization conversion rate, no emulsifier is wasted, there is an economic effect.

The hydrophobic initiator used in the resin latex manufacturing step is a fat-soluble peroxide initiator cumene hydroperoxide, diisopropylbenzene hydroperoxide, tertiary butyl hydroperoxide, paramethane hydroperoxide, benzoyl peroxide; Metal salts selected from the group consisting of iron (II), iron (III), cobalt (II) or cerium (IV) and mixtures of two or more thereof as metal salts as redox-based polymerization initiators, dextrose as a reducing agent, Glucose, fructose, dihydroxyacetone, polyamine, or a reducing agent selected from the group consisting of two or more thereof. The hydrophobic initiator is preferably used in an amount of 0.1 to 0.4% by weight, preferably 0.2 to 0.4% by weight based on the total weight of the reaction mixture, and the polymerization conversion rate does not decrease within this range, and thermal stability Excellent effect.

The rubber latex used as the remaining amount in the resin latex manufacturing step is obtained as described above, preferably may have an average particle diameter in the range of 2500 to 3800 mm 3 and a gel content in the range of 70 to 95%. have.

In general, the graft copolymerization monomer mixture may be used in a continuous, batch or a batch and continuous batch and optionally mixed, but not particularly limited to this, preferably reacting 5 to 40% by weight of the total monomer mixture It is preferable to perform initial batch feeding, and to continuously add the remaining monomer mixture. In addition, in order to control the rate of the graft reaction during graft copolymerization, the reaction temperature is prepared by carrying out a temperature increase reaction of 45 to 85 ° C.

It is preferable that the graft polymerization time is within 4 hours, the polymerization conversion rate after the reaction is 98.5 or more, and the molecular weight of the polymer is preferably 50,000 to 150,000 g / mol as a weight average molecular weight.

The stability of the resin latex of the graft copolymer prepared above was determined by measuring the solidified solid content (%) as shown in Equation 3 below.

[Equation 3]

Solid coagulation (%) = {weight of coagulum produced in the reactor (g) / weight of total rubber and monomers (g)} x 100

When the solidified solid content is less than 0.5% by weight, the latex stability is excellent, and there is less coagulated product, thereby obtaining a graft polymer more suitable for the present invention.

In addition, the graft ratio of the graft polymer is measured as follows. The resin latex of the graft polymer is solidified, washed, and dried to obtain a powder form, and 2 g of this powder is placed in 300 ml of acetone and stirred for 24 hours. The solution is separated using an ultracentrifuge, and then the separated acetone solution is dropped in methanol to obtain an ungrafted portion, which is dried and weighed. From these weights, the graft ratio is calculated according to the following equation (4).

[Equation 4]

Graft Rate (%) = (Weight of Grafted Monomer (g) / Gummy Weight (g)) x 100

At this time, when the graft ratio exceeds 20%, there is a good gloss effect.

The resin latex of the graft copolymer prepared as described above may further include an antioxidant to prevent oxidation during processing. As the antioxidant, phenol-based antioxidants, phosphorus-based antioxidants or sulfur-based antioxidants which are commonly used may be used, and 0.1 to 2.0 to 100 parts by weight of the graft copolymer latex in a state in which the particle size is emulsified to 0.5 to 2 μm. It is preferably included in parts by weight. In general, the antioxidant is preferably slowly added to the resin latex of the graft copolymer at 40 to 80 ℃ and continuously stirred until the coagulation process.

Agglomeration method of the resin latex of the graft copolymer prepared as described above is a step of adding a metal salt or an acid as a coagulant to the resin latex of the graft copolymer, and then aged. The coagulant includes magnesium sulfate (MgSO ₄ ), Calcium chloride (CaCl ₂ ), aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), sulfuric acid, phosphoric acid, hydrochloric acid and the like are preferable.

The resin latex agglomerated as described above may be mechanically dehydrated to obtain a wet powder of 2 to 15% by weight, preferably 2 to 12% by weight, more preferably 5 to 10% by weight. Dehydration as described above may be carried out by mechanical pressurization, preferably by dehydration with a centrifugal dehydrator, and then again with dehydration with a pressurized dehydrator. In general, dehydration uses a centrifugal dehydrator, and in the case of dehydration using such a centrifugal dehydrator, the moisture content of the powder obtained during dehydration is about 30% by weight, and in the case of using a compressed dehydrator according to the present invention, The water content of the powder can be lowered to about 10% by weight.

The moisture content of this invention can be calculated | required using the following formula (5) on 200 degreeC conditions.

[Equation 5]

Water content (%) = (weight of latex resin powder before drying (g)-weight of latex resin powder after drying (g)) / weight of latex resin powder before drying (g) X 100

Thereafter, the wet powder may be wet coextruded together with the aromatic vinyl-vinyl cyan copolymer made by bulk polymerization or melt polymerization, thereby making it pelletized.

The aromatic vinyl-vinyl cyan copolymer is preferably a styrene-acrylonitrile (SAN) copolymer having a weight average molecular weight of 140,000 obtained by bulk polymerization and a vinyl cyan monomer content of 24%.

The mixing ratio of the mixture of the wet powder and the aromatic vinyl-vinyl cyan copolymer is preferably such that the final rubber content in the finally obtained resin is within the range of 10 to 30% by weight so that the wet powder is converted into the aromatic vinyl-vinyl cyan copolymer. With the wet co-extrusion method as extrusion kneading including a water evaporation process, a thermoplastic resin having excellent surface sharpness and glossiness according to the present invention is preferably obtained in the form of pellets. That is, the wet powder extrusion consists of wet coextrusion of the wet powder of the resin latex and the aromatic vinyl-vinyl cyan copolymer while reducing the pressure in the wet coextruder to a pressure below atmospheric pressure (760torr). Preferably, the wet coextrusion may be performed by dividing the wet powder of the resin latex into the coextruder and then adding the aromatic vinyl-vinyl cyan copolymer, wherein the aromatic vinyl-vinyl cyan air is used. Co-extrusion of the wet powder of the resin latex and the aromatic vinyl-vinyl cyan copolymer while vacuum-reducing the pressure in the coextruder to a pressure below atmospheric pressure before and after the incorporation, in this case including residual monomers in the resin. Small residue content has a great effect on improving the thermal stability and surface properties of resin Lose.

Vacuum wet pressure during wet coextrusion is another example, 1 to 760 torr or 1 to 100 torr, 1 to 50 torr, and has optimum thermal stability and surface properties within this range.

The wet powder as the extruded kneading process including a water evaporation process in an extruder at 200 to 250 ° C. is preferably added to the mixture of the wet powder and the aromatic vinyl-vinyl cyan copolymer. It can be wet coextruded by the extrusion method.

The water evaporation process is, for example, a process in which water evaporates at a high temperature, in which case it is effective to remove low boiling residues including residual monomers in the resin.

Hereinafter, preferred examples are provided to help understanding of 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. Naturally, changes and modifications belong to the appended claims.

EXAMPLE

Example 1

(1) Preparation of rubber latex

75 parts by weight of ion-exchanged water, 100 parts by weight of 1,3-butadiene as monomer, and 1.5 parts by weight of alkenylsuccinate dipotassium salt of EL16 (C18-18) as a reactive emulsifier in a nitrogen-substituted polymerization reactor (autoclave) , 2.0 parts by weight of potassium carbonate (K ₂ CO ₃ ) as an electrolyte, 0.3 parts by weight of tertiary dodecyl mercaptan (TDDM) as a molecular weight control agent, 0.2 parts by weight of potassium persulfate as an initiator, and 10 hours at a reaction temperature of 70 ℃ Reacted for a while. When the polymerization conversion rate of the reactant is 50%, 0.05 wt% of tertiary dodecyl mercaptan is collectively administered and reacted at 75 ° C. for 20 hours, and when the polymerization conversion rate is 90%, a polymerization inhibitor is added and the reaction is terminated. . And the obtained rubber latex was analyzed. The particle size of the obtained rubber latex was 3100 mm 3 on average, and the gel content was 85%.

(2) Preparation of Resin Latex of Graft Copolymer

60 parts by weight of polybutadiene rubber latex (based on solids), 70 parts by weight of ion-exchanged water, and 5 parts of styrene as monomers in a nitrogen-substituted polymerization reactor (autoclave) having an average particle diameter of 3100 mm 3 and a gel content of 85% After adding 2 parts by weight of acrylonitrile, the reactor temperature was maintained at 50 ° C., followed by 0.05 parts by weight of cumene hydroperoxide, 0.09 parts by weight of sodium pyrophosphate, 0.12 parts by weight of textose, and 0.002 parts by weight of ferrous sulfide. The batch was injected. Thereafter, 23 parts by weight of styrene, 10 parts by weight of acrylonitrile, 0.25 parts by weight of ethyl-2-mercaptoethylpropionate, and 0.12 parts by weight of cumene hydroperoxide were continuously injected while raising the temperature to 75 ° C. for 2 hours. In parallel with the above, 0.2 parts by weight (based on solids, 28% aqueous solution) of alkenylsuccinate dipotassium salt of 16 to 18 carbon atoms (ELOPLA AS100) as a reactive emulsifier was continuously added for 2 hours. After the continuous injection, 0.06 part by weight of cumene hydroperoxide, 0.04 part by weight of sodium pyrophosphate, 0.06 part by weight of dextrose and 0.001 part by weight of ferrous sulfide were added, and the temperature was raised to 80 ° C. for 30 minutes, followed by holding for 30 minutes. And the reaction was terminated. At this time, the polymerization conversion rate was 99%, the coagulation content was 0.03%, the graft rate was 38%.

0.5 parts by weight of an antioxidant (winstay-L / IR1076 = 0.8 / 0.2) emulsion having an average particle diameter of 0.9 μm was added to the resin latex of the finished graft copolymer, and then, 85 ° C., in the presence of 2.0% by weight of MgSO _4. The mixture was further agglomerated and secondary aged at 97 ° C., followed by dehydration with a centrifugal dehydrator to obtain a powdery graft copolymer having a water content of 30%. The resin powder of the powdery graft copolymer having a water content of 30% was dehydrated again to have a water content of 10% in a pressurized dehydrator, to obtain a wet powder.

(3) Wet Powder Extrusion Process

ABS graft copolymer in the wet powder state prepared in the above general SAN resin (LG Chemical, South Korea, Grade name: 80HF, prepared by the bulk polymerization method; weight average molecular weight 140,000, acrylonitrile content Styrene-acrylonitrile copolymer (24%), a lubricant, an antioxidant, and a light stabilizer were added, and then kneaded at 200 to 250 ° C. using a wet powder extruder, and the resin was introduced into the wet coextruder. After the wet powder of latex is added, the aromatic vinyl-vinyl cyan copolymer is added in a manner of adding, but before and after the addition of the aromatic vinyl-vinyl cyan copolymer, the pressure in the wet coextruder is 8 torr. While vacuum decompression, the wet powder of the resin latex and the aromatic vinyl-vinyl cyan copolymer were wet coextruded to prepare pellets so that the rubber content was 15%. After the fabrication of the test piece was measured for its physical properties. At this time, moisture, residual monomers, etc. were discharged through a vacuum line connected to the extruder stop.

Physical properties were measured by injecting this pellet again. Surface sharpness was visually determined, and properties such as glossiness, impact strength, and fluidity were measured by ASTM method (impact strength according to ASTM D256, fluidity according to ASTM D1238, and glossiness according to ASTM D528). It was measured and compared with a Hunter (Hunter Lab.) Color measuring machine (Hunter Lab., USA), and the thermal stability was compared through an injection retention test (20 minutes at 250 ℃ when injection). Measured physical properties are shown in Table 1.

Example 2

It was carried out in the same manner as in Example 1 except that 0.2 parts by weight of HITENOL KH-10 as a reactive emulsifier was continuously injected for 2 hours.

Example 3

The reaction method was carried out in the same manner as in Example 1, except that 0.2 part by weight of dodecyl allylsulfosuccinate sodium salt (TREM LF-40) was continuously injected for 2 hours.

Example 4

The same procedure as in Example 1 was carried out except that 0.15 parts by weight of ethyl-2-mercaptoethylpropionate and 0.1 part by weight of tertiary dodecyl mercaptan were used as a molecular weight regulator.

Example 5

70 parts by weight of polybutadiene rubber latex having a particle size of rubber latex of 3,100 mm 3 and a gel content of 85% (based on solids), 100 parts by weight of ion-exchanged water, 7.2 parts by weight of styrene as monomer and 2.8 parts by weight of acrylonitrile, After maintaining the reactor temperature at 50 ° C, 0.05 parts by weight of cumene hydroperoxide, 0.09 parts by weight of sodium pyrophosphate, 0.12 parts by weight of textose and 0.002 parts by weight of ferrous sulfide were added. Thereafter, 14.0 parts by weight of styrene, 6.0 parts by weight of acrylonitrile, 0.3 parts by weight of ethyl-2-mercaptoethylpropionate, and 0.12 parts by weight of cumene hydroperoxide were continuously added while raising the temperature to 75 ° C. for 2 hours 30 minutes. . In parallel with the above Example 1 except that 0.2 parts by weight (28% aqueous solution) of alkenyl succinate dipotassium salt having 16 to 18 carbon atoms (ELOPLA AS100) as a reactive emulsifier was continuously added for 2 hours and 30 minutes. Was performed in the same manner.

Comparative Example 1

It was carried out in the same manner as in Example 1 except that 1.2 parts by weight of fatty acid soap and 0.4 parts by weight of tertiary dodecyl mercaptan were continuously injected for 3 hours instead of the reactive emulsifier. After the continuous addition, 0.06 parts by weight of cumene hydroperoxide, 0.04 parts by weight of sodium pyrophosphate, 0.06 parts by weight of dextrose and 0.001 parts by weight of ferrous sulfide were heated to 80 ° C. for 30 minutes, and maintained for 30 minutes. Terminated. Measured physical properties are shown in Table 2.

Comparative Example 2

It was carried out in the same manner as in Example 1 except that 0.3 parts by weight of persulfate instead of cumene hydroperoxide as an initiator and 0.4 parts by weight of tertiary dodecyl mercaptan as a molecular weight regulator were continuously injected for 3 hours. Measured physical properties are shown in Table 2.

Comparative Example 3

Instead of using a pressurized dehydrator and wet coextrusion, only a 30% moisture content was dried by a dryer using a Winsim dehydrator to obtain a resin in the form of pellets having a water content of 0.8%, which is generally used instead of wet coextrusion. The resin was prepared by extrusion kneading using a twin screw extruder. Measured physical properties are shown in Table 2.

Table 1 Example 1 Example 2 Example 3 Example 4 Example 5 Graft Rate (%) 38 39 38 37 32 Surface sharpness (visual judgment) Very good Very good Very good Very good Very good Surface glossiness 110 109 110 109 107 Impact strength (㎏ · cm / ㎝) 31 32 31 30 28 MFR (g / 10min) 23 24 24 22 20 % Of retention gloss 2 One One 2 3 Retention Color Difference (ΔE) <2.0 Mold Sedimentation (Visual Judgment) Very good Very good Very good Very good Very good

TABLE 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Graft Rate (%) 37 35 38 Surface sharpness (visual judgment) usually Great usually Surface glossiness 104 107 99 Impact strength (㎏ · cm / ㎝) 32 23 31 MFR (g / 10min) 25 21 25 % Of retention gloss 5 4 4 Retention Color Difference (ΔE) <5.0 <3.0 <4.0 Mold Sedimentation (Visual Judgment) usually Great usually

As a result of the evaluation, as shown in Table 1 and Table 2, the method of manufacturing the thermoplastic resin composition of the present invention is the same or similar in physical properties such as graft rate, impact strength and fluidity, in particular surface sharpness, surface glossiness, retention gloss change rate, It was confirmed that an excellent thermoplastic resin, which is particularly excellent in terms of sharpness, glossiness, and / or color effect such as retention color difference reduction, and without mold precipitation, can be obtained.

Claims (20)

(1) preparing a rubber latex from the conjugated diene monomer using a reactive emulsifier; (2) graft copolymerizing an aromatic vinyl monomer and a vinyl cyan monomer to the rubber latex using a hydrophobic initiator to prepare a graft resin latex; (3) aggregating and then dehydrating the graft resin latex to obtain a wet powder; And (4) wet extruding the wet powder together with the aromatic vinyl-vinyl cyan copolymer to produce an extrudate; Method for producing a thermoplastic resin composition comprising a. The method of claim 1, Step (2) is a method for producing a thermoplastic resin composition, characterized in that the reactive emulsifier is used during graft copolymerization. The method of claim 1, Dehydration of the step (3) is a method for producing a thermoplastic resin composition, characterized in that carried out by a compression dewatering method. The method of claim 1, The wet powder of step (3) is a method for producing a thermoplastic resin composition, characterized in that the water content is 2 to 15% by weight. The method of claim 1, The wet coextrusion of step (4) is carried out under vacuum decompression conditions. The method of claim 5, The wet coextrusion is carried out under a vacuum decompression condition of 1 to 760 torr. The method of claim 1, The wet coextrusion of the step (4) is a method for producing a thermoplastic resin composition comprising a water vaporization process. The method of claim 1, In the wet coextrusion of step (4), the wet powder is first introduced, followed by the aromatic-vinyl cyan copolymer. The method of claim 1, Step (4) is a method for producing a thermoplastic resin composition, characterized in that the wet coextrusion of step (4) continuously without the drying step after the dehydration of the step (3). The method of claim 1, Method for producing the thermoplastic resin composition, (1) a rubber latex manufacturing step of preparing a rubber latex using 1.0 to 3.0 parts by weight of a reactive emulsifier based on 100 parts by weight of the conjugated diene monomer; (2) 18 to 40% by weight of an aromatic vinyl monomer, 8 to 18% by weight of a vinyl cyan monomer, 0.1 to 0.7% by weight of a reactive emulsifier, 0.1 to 0.4% by weight of a hydrophobic initiator, and a balance to obtain the resulting rubber latex. Resin latex manufacturing step of producing a resin latex of the graft copolymer by emulsion polymerization of the reaction mixture; (3) aggregating the resin latex, followed by dehydration to obtain a wet powder; And (4) wet co-extrusion of the wet powder with an aromatic vinyl-vinyl cyan copolymer, and wet co-extrusion so that the rubber content of the final resin is within the range of 10 to 30% by weight; Method for producing the thermoplastic resin composition comprising a. The method of claim 1, Anionic and neutral polymeric emulsifiers having an allyl group, the anionic and neutral polymeric emulsifiers having a (meth) acryloyl group, anionic or neutral polymeric emulsifiers having a propenyl group, and two of them. A method of producing the thermoplastic resin composition, characterized in that the reactive emulsifier selected from the group consisting of the above mixture. The method of claim 10, (1) the method for producing a thermoplastic resin composition, characterized in that the gel content adjusting agent is further contained in an amount within the range of 0.1 to 1.0 parts by weight in the rubber latex step. The method of claim 12, The gel content regulators are ethyl-2-mercaptoethylpropionate, 2-mercaptoethylpropionate, 2-mercaptoethanol, mercaptoacetic acid, n-octyl mercaptan, n-dodecyl mercaptan, t- Dodecyl mercaptan and a method for producing the thermoplastic resin composition, characterized in that it is selected from the group consisting of two or more of these. The method of claim 1, The rubber latex of step (1) is a method for producing the thermoplastic resin composition, characterized in that it has a swelling index of 5 to 25. The method of claim 1, (1) The method for producing a thermoplastic resin composition, wherein the rubber latex has an average particle diameter within a range of 2500 to 3800 mm 3. The method of claim 1, The rubber latex of step (1) is a method for producing the thermoplastic resin composition, characterized in that it has a gel content within the range of 70 to 95%. The method of claim 1, The method for producing the thermoplastic resin composition, characterized in that 0.1 to 0.4% by weight of the molecular weight regulator is further included in the preparation of the graft resin latex of step (2). The method of claim 1, (2) The method for producing the thermoplastic resin composition, characterized in that the molecular weight of the graft resin latex is in the range of 50,000 to 150,000 g / mol as a weight average molecular weight. The method of claim 3, wherein The dehydration of the step (3), after the dehydration with a centrifugal dehydrator, the method for producing the thermoplastic resin composition, characterized in that the dehydration with a pressurized dehydrator again. 20. A thermoplastic resin composition, which is prepared by the process for producing the thermoplastic resin composition of claims 1 to 19.