KR20060040016A - Method of preparing abs resin controlling the glossness - Google Patents

Abstract

According to the present invention, a method of preparing acrylonitrile-butadiene-styrene (ABS) resin having easy glossiness control may be achieved by polymerizing a monomer mixture composed of acrylonitrile and styrene on agglomerated rubber latex and acrylonitrile-butadiene-styrene (ABS). In preparing the resin, the step of chemical agglomeration by adding a particle size-enhancing agent to the seed rubber latex of 1000 to 2500 mm 3 as the agglomerated rubber latex and mechanical coagulation using mechanical agitation force by a gear pump By using the cohesive rubber latex produced by flocculation in parallel, the acrylonitrile not only can easily control glossiness of acrylonitrile-butadiene-styrene (ABS) resin but also maintain excellent impact resistance and fluidity. Butadiene-styrene (ABS) resins can be prepared.

Particle Sizer, Cohesive Rubber Latex, Chemical Coagulation, Mechanical Coagulation, Glossiness, Impact Resistance, Fluidity

Description

Method for preparing acrylonitrile-butadiene-styrene (ABS) resin with easy gloss control {Method of Preparing ABS Resin Controlling the Glossness}

Field of invention

This invention relates to the acrylonitrile-butadiene-styrene (ABS) resin composition manufacturing method for glossiness control using a particle size enlargement agent. More specifically, the present invention relates to a method for preparing an acrylonitrile-butadiene-styrene (ABS) resin composition that can be easily controlled for glossiness through a process change of adding and mixing a particle size-enhancing agent to a rubber latex polymer.

Background of the Invention

Generally acrylonitrile-butadiene-styrene (ABS) resins are copolymers of acrylonitrile monomers, butadiene monomers and styrene monomers. They are in harmony with various physical properties such as stiffness, weather resistance, chemical resistance, impact resistance, gloss and moldability in the acrylonitrile-butadiene-styrene (ABS) resin. A typical acrylonitrile-butadiene-styrene (ABS) resin manufacturing process is to polymerize butadiene monomers through conventional emulsion polymerization, and then, in order to secure a decrease in compatibility between butadiene rubber styrene and acrylonitrile, Acrylonitrile and graft polymerization are obtained through an extrusion process of mixing at a constant temperature with styrene and acrylonitrile copolymer obtained through dispersion polymerization or bulk polymerization.

In acrylonitrile-butadiene-styrene (ABS) resins, butadiene rubber improves impact resistance, but in the entire acrylonitrile-butadiene-styrene (ABS) resin manufacturing process, since it is made by a conventional emulsion polymerization method with a long polymerization time, The production time of the acrylonitrile-butadiene-styrene (ABS) resin will be influenced. In order for the butadiene rubber to have impact resistance in acrylonitrile-butadiene-styrene (ABS) resin, it should have a particle size of a certain size or more. In order to polymerize butadiene rubber of a certain size or more through emulsion polymerization, a long polymerization time is required. Required.

In order to reduce the production time of the rubber latex, the polymerization time has been shortened by copolymerization with styrene or acrylic monomers, but the polymerization time has not been drastically reduced.

Accordingly, various methods of enlarging the particle size in a short time after preparing butadiene rubber latex or copolymer rubber latex having a relatively short polymerization time have been proposed. These methods are freeze-incorporation of small particle rubber latex or enlarging the particle size by mechanical or chemical methods.

These methods are well known methods, but there is a problem that the stability after the particle size enlargement, or change over time, and coagulum occurs a lot. Even if these problems are solved, the synthetic rubber latex having a large particle size in a short time has high impact properties when applied to acrylonitrile-butadiene-styrene (ABS) resin through large particle size when the coagulation rate is high. It causes problems such as poor fluidity and appearance. When the coagulation rate is low, it is difficult to increase the rubber content due to the problem of lowering the impact resistance and the relatively increased specific surface area and unaggregated small particle rubber latex during graft polymerization.

In order to solve the above problems, the present inventors adjust the process conditions of adding and mixing the particle size-enhancing agent used for agglomeration, so that the impact resistance and fluidity are kept the same, while acrylonitrile-butadiene- can be freely controlled. It is about to develop a method for producing styrene (ABS) resin.

An object of the present invention is to provide a method for producing an acrylonitrile-butadiene-styrene (ABS) resin composition capable of freely controlling glossiness.

Another object of the present invention is to provide a method for producing an acrylonitrile-butadiene-styrene (ABS) resin composition having excellent impact resistance and fluidity.

Still another object of the present invention is to provide a method for preparing an acrylonitrile-butadiene-styrene (ABS) resin composition having a small change with time after aggregation.

It is still another object of the present invention to provide a method for producing an acrylonitrile-butadiene-styrene (ABS) resin composition in which coagulation formation is reduced during the preparation of agglomerated rubber latex.

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

Hereinafter, the content of the present invention will be described in detail below.

Summary of the Invention

According to the present invention, a method of preparing acrylonitrile-butadiene-styrene (ABS) resin having easy glossiness control may be achieved by polymerizing a monomer mixture composed of acrylonitrile and styrene on agglomerated rubber latex and acrylonitrile-butadiene-styrene (ABS). In preparing the resin, the step of chemical agglomeration by adding a particle size-enhancing agent to the seed rubber latex of 1000 to 2500 mm 3 as the agglomerated rubber latex and mechanical coagulation using mechanical agitation force by a gear pump By using a cohesive rubber latex prepared by the coagulation step in parallel, characterized in that the glossiness of the acrylonitrile-butadiene-styrene (ABS) resin is easily adjusted.

Hereinafter, a detailed description of each of these steps is as follows.

Detailed Description of the Invention

(1) Preparation and Pretreatment of Particle Sizer

The method for preparing the particle size increasing agent and the pretreatment method used in the present invention are disclosed in Korean Patent Application No. 2002-28672, which is incorporated herein by reference.

As the particle size increasing agent used in the present invention, copolymer latex containing unsaturated acid is applied. As the monomer for producing the copolymer, an unsaturated acid monomer having a carboxyl group is preferable. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, methyl acrylic acid, itaconic acid, crotonic acid, fumaric acid, Methylene unsaturated carboxylic acids such as maleic acid; Acrylate monomers such as methyl methacrylate, methyl acrylate and ethyl acrylate copolymerizable with these; C4-6 conjugated double bond monomers, such as butadiene and isoprene; Monovinyl aromatic hydrocarbon monomers such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; And acrylonitrile, methacrylonitrile monomers. The particle size-enhancing agent is preferably prepared by copolymerizing at least one or more unsaturated acid monomers.

The pretreatment process is performed by mixing and stirring an appropriate amount of ion-exchanged water, a nonionic emulsifier, and an electrolyte with the prepared particle size-enhancing agent to adjust the solids content of the copolymer latex to 1 to 10% by weight, and to adjust the pH to 5 to 11.

The particle size increasing agent is most stable when the pH is 5 to 11.

The solid content of the particle size-enhancing agent is not particularly defined, but is usually 10 to 50% by weight, it is adjusted to 1 to 10% by weight by pretreatment.

(2) flocculation step [chemical flocculation and mechanical flocculation]

Chemical agglomeration method is 1 to 10 parts by weight of the pre-treated particle size thickener prepared in 100 parts by weight of 1000 to 2500 Å seed rubber latex prepared by conventional emulsion polymerization method into the reactor for 10 minutes by slowly stirring at 100 rpm to 300 rpm To aggregate for 60 minutes. When the particle size of the rubber latex is less than 1000 mm 3, the solid content of the rubber latex due to viscosity cannot be increased by 40% by weight or more, and thus the manufacturing efficiency and stability are lowered.

In the region below 100 rpm, due to the viscosity of the rubber latex, it is not suitable for sufficient mixing of the rubber latex and the particle size increasing agent, so that the particle diameter composition of the agglomerated rubber latex is changed or the stability portion is lowered. In the region of more than 300 rpm, mechanical coagulation effects other than chemical coagulation of rubber latex due to strong mechanical stirring force are generated. Agitators in conventional reactors are also designed for effects by sufficient mixing, causing equipment problems at high rpms.

 In addition, when the aggregation time is less than 10 minutes, the coagulation rate is unstable, so that uniform cohesion rubber cannot be obtained. When the coagulation time is more than 60 minutes, the extent of increase of the coagulation rate is very small, which is desirable in view of the particle size enlargement efficiency of the coagulated rubber and the production time. I can't.

In the mechanical flocculation method, a particle size-enhancing agent is added and agglomerates at about 1000 rpm to 15000 rpm for 1 minute to 10 minutes using a gear pump. The coagulation by mechanical agitation is very important to destabilize the interface of rubber latex and re-stabilization by coagulation, depending on the mechanical agitation force and the composition of the coagulant. littleness. On the other hand, if the stirring force is more than 15000 rpm or more than 10 minutes, the stability of the rubber latex itself may be lowered.

In the present invention, the chemical coagulation step and the mechanical coagulation step are coagulated in parallel.

(4) graft polymerization of rubber latex

10 parts by weight of acrylonitrile monomer and 60 parts by weight of agglomerated rubber latex prepared above in a graft polymerization reactor Graft polymerization is performed by mixing 30 parts by weight of monomers.

In the graft polymerization, a mixture of monomers composed of acrylonitrile and styrene is added to the reactor at 25 to 50% by weight of the total monomer mixture together with a molecular weight modifier, an emulsifier, a polymerization initiator, ion-exchanged water and a reducing agent. After heating up to ℃, the catalyst compound is added to the first graft polymerization. More preferably, the mixture of monomers is added to the reactor at 30 to 37% by weight of the total monomer mixture. Thereafter, the remaining monomer mixture is slowly added for 2 hours to form a second graft polymerization.

If it is less than 25% by weight, the monomer ratio used in the first polymerization is small, so that many monomers are added to the second polymerization, resulting in a decrease in manufacturing efficiency and a large amount of residual monomers. However, due to insufficient graft polymerization cell shell (shell density), the rubber surface is exposed, which causes the appearance property deterioration due to agglomeration of rubbers in the manufacture of ABS resin.

Specific examples of the molecular weight regulator and the initiator used in the graft polymerization in the present invention was applied to the bar described in the Republic of Korea Patent Application No. 2002-28672 integrally.

The present invention will be further illustrated by the following examples, which are only described for the purpose of illustrating the present invention and are not intended to limit the protection scope of the present invention.

Example

(A) First step: Preparation and pretreatment of particle size increasing agent

The copolymer latex, which is a particle size increasing agent, has 185 parts by weight of ion-exchanged water, 4 parts by weight of methacrylic acid, 96 parts by weight of ethyl acrylate, 5.0 parts by weight of potassium oleate, 0.5 parts by weight of potassium carbonate and 0.5 parts by weight of potassium persulfate. It was prepared by polymerization at 6 ° C. for 6 hours. The latex prepared had a particle size of 650 mm 3, a solid content of 30 wt%, and a pH of 2.5.

1 part by weight of the nonionic emulsifier and 1 part by weight of 88 parts by weight of ion-exchanged water were mixed with 10 parts by weight of the particle size-enhancing agent latex thus prepared to obtain a solid content of 3% by weight, and the pH thereof was 8.

(B) Second Step: Coagulation Step (Preparation Example 1-6)

Preparation Example 1

100 parts by weight of a seed rubber latex having a particle diameter of 2000 mm 3 prepared by a conventional emulsion polymerization method was added to a reactor, and 50 ° C. After heating to 3 parts by weight of pretreated particle size-enhancing agent was added and stirred at 250 rpm for 30 minutes to aggregate. The agglomerated rubber latex was put in front of a gear pump, and the pump was circulated at 10000 rpm for 1 minute.

The size of the prepared particle size after aggregation was 2520 mm 3, and the amount of coagulum generated was 0.1%.

Preparation Example 2

Rubber latex coagulated under the conditions of Preparation Example 1 was put into the gear pump (Gear Pump) front end and the pump was agglomerated by circulating for 5 minutes at 10000 rpm.

The size of the prepared particle size after aggregation was 3100 mm 3, and the amount of coagulum generated was 0.1%.

Preparation Example 3

Agglomerated under the same conditions as Preparation Example 1, except that the particle size-enhancing agent was changed to 4 parts by weight.

The size of the prepared particle size after aggregation was 2911 Å, and the amount of coagulum generated was 0.1%.

Preparation Example 4

Agglomerated under the same conditions as Preparation Example 2, except that the particle size-enhancing agent was changed to 4 parts by weight.

The size of the prepared particle diameter after aggregation was 3251 mm 3, and the amount of coagulated matter was 0.1%.

The particle size change after each aggregation was measured by NICOMP 370 (particle size analyzer).

(C) step 3: graft polymerization of agglomerated rubber latex

60 parts by weight of rubber latex of Preparation Example 1 of Table 1, 3.5 parts by weight of acrylonitrile monomer, 10.5 parts by weight of styrene monomer, 0.09 part by weight of terceridodecylmercaptan, 0.1 part by weight of cumene hydroperoxide, in a graft polymerization reactor After adding 0.2 parts by weight of potassium stearate, 0.3 parts by weight of sodium hydroxide and 140 parts by weight of ion-exchanged water, the temperature of the reactor was raised to 60 ° C, 0.003 parts by weight of ferrous sulfate and 0.15 parts by weight of tetrasodium parophosphate. The first graft polymerization was carried out.

Secondary graft polymerization was continuously performed immediately after the reactor temperature reached 70 ° C. due to the heat of polymerization generated during the first graft polymerization. 6.5 parts by weight of acrylonitrile monomer, 19.5 parts by weight of styrene monomer and 0.2 parts by weight of terceridodecylmercaptan were mixed and stirred into the first graft polymer, and 0.22 parts by weight of cumene hydroperoxide was added to the reactor at a constant rate for 2 hours. To proceed with the secondary polymerization.

The graft polymerization was carried out in the same manner for the agglomerated rubber latex of Production Examples 2, 3, and 4, respectively.

Physical properties after each graft polymerization are shown in Table 1 below.

Example Amount of coagulation Graft efficiency Particle size One 0.08% 90.5% 2742 yen 2 0.07% 90.1% 3240Å 3 0.08% 90.1% 3189Å 4 0.09% 90.2% 3413Å

Comparative Example 1

Graft polymerization was carried out under the same conditions as in Example 1, except that 60 parts by weight of an average particle diameter of 2600 mm 3 rubber latex obtained through conventional emulsion polymerization was used.

Comparative Example 2

Average particle size 3100 얻은 obtained through conventional emulsion polymerization Graft polymerization was performed under the same conditions as in Example 1 except that 60 parts by weight of rubber latex was used.

The coagulant amount, graft efficiency and particle diameter of the prepared latex are shown in Table 2 below.

Comparative Example Amount of coagulation Graft efficiency Particle diameter One 0.13% 89.9% 2897 yen 2 0.11% 90.2% 3300 yen

Preparation and Evaluation of Acrylonitrile-Butadiene-Styrene (ABS) Resin Compositions

Seven kinds of graft-acrylonitrile-butadiene-styrene (ABS) powders prepared in Examples 1-6 and Comparative Example 1-2 were expressed in acrylonitrile-butadiene-styrene (ABS) resin Acrylonitrile-butadiene-styrene (ABS) resin compositions were prepared in the following manner to evaluate the properties.

25 parts by weight of graft copolymer, 27 parts by weight of acrylonitrile content, 120,000 parts by weight average molecular weight of 120,000 and molecular weight distribution of 1.88 parts by weight, 1 part by weight of calcium stearate and 1 part by weight of ethylenebisstearoid as stabilizer The mixture was extruded and injection molded to prepare a specimen for measuring physical properties. The physical properties of the prepared specimens were evaluated and shown in Table 3 below.

Properties Example Comparative Example One 2 3 4 One 2 Izod impact strength (1/4 "notch, ASTM D256) 21 21 22 23 16 22 Flow Index (ASTM D1238) 6.6 6.5 6.4 6.4 6.4 6.4 Glossiness (60 °, ASTM D523) 92 75 68 55 92 87 Glossiness (20 °, ASTM D523) 70 55 37 21 70 65

As shown in Tables 1 and 2, it is possible to increase the amount of coagulation and the graft efficiency by adjusting the particle size-enhancing agent and the coagulation process, as shown in Table 3, the gloss can be adjusted from 92 to 55 at an angle of 60 °, Adjustable from 70 to 21 at a 20 ° angle. In addition, as shown in Table 3 above, when the particle size-adding agent is used in the acrylonitrile-butadiene-styrene (ABS) resin, rubber latex prepared by conventional emulsion polymerization by controlling the process of adding and mixing the particle size-adding agent Equivalent to or better than physical properties, it was confirmed that various gloss can be adjusted.

The present invention provides a solidification that can occur in acrylonitrile-butadiene-styrene (ABS) resin using agglomerated rubber latex while maintaining the excellent impact resistance and fluidity properties through the process change of adding and mixing the particle size-enhancing agent. It has the effect of reducing the amount of water (coagulum) and providing a method for producing acrylonitrile-butadiene-styrene (ABS) resin having excellent glossiness control.                     

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (5)

In graft polymerization of a monomer mixture composed of acrylonitrile and styrene to agglomerated rubber latex to prepare acrylonitrile-butadiene-styrene (ABS) resin, the seed rubber latex of 1000 to 2500 mm 3 is used as the agglomerated rubber latex. Acrylonitrile-butadiene-styrene using agglomerated rubber latex, which is prepared by agglomerating a chemical particle by adding a particle size-enhancing agent and performing mechanical agglomeration using a mechanical stirring force by a gear pump ( ABS) method of producing the resin. The method of claim 1, wherein the chemical agglomeration is slowly stirring at 100 rpm to 300 rpm in the reactor to prepare an acrylonitrile-butadiene-styrene (ABS) resin, characterized in that the aggregation for 10 to 60 minutes. The method of claim 1, wherein the mechanical coagulation of the acrylonitrile-butadiene-styrene (ABS) resin, characterized in that the mechanical agglomeration for 1 minute to 10 minutes at 1000 rpm to 15000 rpm using a gear pump (Gear Pump) Manufacturing method. The method according to claim 1, wherein the particle size-enhancing agent is a copolymer latex solid content of 1 to 10% by weight, and a pH of 5 to 11 by mixing and stirring ion-exchanged water, a nonionic emulsifier and an electrolyte in an unsaturated acid-containing copolymer latex A process for producing acrylonitrile-butadiene-styrene (ABS) resins, which is prepared and pretreated by adjusting to The method of claim 5, wherein the monomer for preparing the unsaturated acid-containing copolymer latex is acrylic acid, methacrylic acid, methyl acrylic acid, itaconic acid, Methylene unsaturated carboxylic acids such as crotonic acid, fumaric acid and maleic acid; Acrylate monomers such as methyl methacrylate, methyl acrylate and ethyl acrylate copolymerizable with these; C _4-6 conjugated double bond monomers such as butadiene and isoprene; Monovinyl aromatic hydrocarbon monomers such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; And acrylonitrile, methacrylonitrile monomers, and at least one selected from the group consisting of acrylonitrile-butadiene-styrene (ABS).