KR100527095B1 - Method for Preparing Thermoplastic Copolymer with Excellent Whiteness and Surface Gloss - Google Patents

Abstract

The present invention relates to a method for producing a thermoplastic acrylonitrile-butadiene-styrene (ABS) resin having excellent whiteness and surface glossiness through emulsion polymerization. The present invention is to perform the graft polymerization by the emulsion polymerization method by introducing an acrylonitrile monomer, a styrene monomer, and an acrylate monomer to the butadiene rubber polymer, so that the mixture of acrylonitrile monomer and styrene monomer is polymerized in the rubber polymer One-step reaction to impart impact resistance, two-step reaction to evenly polymerize acrylate monomer to rubbery outer surface, and glossiness of resin by allowing acrylonitrile monomer and styrene monomer to polymerize evenly to rubbery outer surface It consists of a three step reaction to keep it good. The graft copolymer prepared by the above method and the SAN resin are mixed by the bulk polymerization method to prepare an ABS thermoplastic resin having excellent whiteness and surface glossiness.

Description

Method for preparing thermoplastic copolymer resin excellent in whiteness and surface gloss {Method for Preparing Thermoplastic Copolymer with Excellent Whiteness and Surface Gloss}

Field of invention

The present invention relates to a method for producing a thermoplastic acrylonitrile-butadiene-styrene (ABS) resin having excellent whiteness and surface glossiness through emulsion polymerization. More specifically, the present invention is a whiteness prepared by mixing a graft copolymer and a styrene-acrylonitrile copolymer (SAN) prepared by graft polymerization of an acrylonitrile monomer, a styrene monomer, and an acrylic monomer to a butadiene rubbery polymer. And an ABS thermoplastic resin having excellent surface glossiness.

Background of the Invention

Generally, ABS resin is a general term of impact resistant thermoplastic resin composed of three components of acrylonitrile, butadiene, and styrene, and is called ABS resin or ABS terpolymer by taking these three components. It is called. ABS resin is balanced and reflects excellent physical properties and is widely used in various fields. The main thing is so-called household electrical and electronic products such as refrigerators, washing machines, and TVs, and is widely used as automobile parts and general office supplies.

ABS resin is largely manufactured by continuous bulk polymerization and emulsion polymerization. Among them, bulk polymerization has advantages such as mass production, low manufacturing cost and excellent whiteness compared to emulsion polymerization, while high value added through product diversification and specialization. There is a disadvantage that can not be achieved, the emulsion polymerization method has the advantage of being able to manufacture a specialized high value-added product with excellent physical property control ability has a disadvantage of high manufacturing cost and low whiteness.

The present invention is to provide a new method for producing an ABS resin having excellent whiteness and surface gloss by overcoming the disadvantage of lowering the whiteness in the production of ABS resin by emulsion polymerization method.

An object of the present invention is to provide a method for producing a thermoplastic acrylonitrile-butadiene-styrene (ABS) resin having excellent whiteness and surface glossiness through emulsion polymerization.

Another object of the present invention is to provide a method for producing a thermoplastic ABS resin excellent in impact resistance and weather resistance.

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

Summary of the Invention

In the method for producing ABS resin having excellent whiteness and surface glossiness according to the present invention, 30 to 50 parts by weight of butadiene rubbery latex having an average particle diameter of 0.2 to 0.33 µm is added to the reactor with an aromatic vinyl monomer and a vinyl cyanide monomer, A first step of preparing a primary graft copolymer latex by adding a fat soluble initiator after adding a stirring agent, an emulsifier, and ion-exchanged water and stirring the reactor; A second step of preparing a second graft copolymer latex by adding and polymerizing an acrylate monomer mixture, a water-soluble initiator, and a molecular weight regulator in the presence of the first graft copolymer latex prepared in the first step; And a third step of preparing a tertiary graft copolymer by adding and polymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, a water-soluble initiator, and a molecular weight regulator in the presence of the secondary graft copolymer latex.

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

Detailed Description of the Invention

The present invention relates to a new method for producing an ABS resin having excellent whiteness and surface gloss by overcoming the disadvantage of lowering the whiteness in the production of ABS resin by emulsion polymerization.

ABS resin having excellent whiteness and surface gloss according to the present invention is prepared by introducing an aromatic vinyl monomer and a vinyl cyanide monomer into the reactor in a butadiene rubbery latex, and a fat-soluble initiator to prepare a first graft copolymer latex Preparing a secondary graft copolymer latex by introducing an acrylate monomer mixture and a water-soluble initiator in the presence of the primary graft copolymer latex prepared above; And preparing a tertiary graft copolymer by adding an aromatic vinyl monomer, a vinyl cyanide monomer, and a water-soluble initiator in the presence of the secondary graft copolymer latex. A detailed description of each of these steps follows.

(1) First Step: Preparation of Primary Graft Copolymer Latex

Ion-exchanged water is added to 30 to 50 parts by weight of a rubbery polymer having an average particle diameter in the range of 0.28 to 0.33 µm and a gel content of 75 to 85% by weight, 8 to 12 parts by weight of an aromatic vinyl monomer, and 2 to 5 parts by weight of a vinyl cyanide monomer. And a molecular weight modifier are mixed and added, then an emulsifier is added and then heated while stirring. When the temperature of the reaction system reaches 55 to 65 ° C, the polymerization reaction is started by adding a fat-soluble pyrolysis initiator. When the reaction is started and the temperature of the reaction system increases and the internal temperature of the reactor reaches 75-80 ° C, the internal temperature of the reactor is maintained at 75-80 ° C using a cooler and the reaction is continued for 30-90 minutes. Primary graft copolymer latexes are prepared by cooling the reactor above 93% and terminating the polymerization.

(2) Second Step: Preparation of Secondary Graft Copolymer Latex

In the presence of the first graft copolymer latex prepared by the first step reaction, a water-soluble initiator was added to the reactor at a temperature of 70 to 75 ° C., stirred for 5 to 10 minutes, and then 10 to 20 parts by weight of the acrylic monomer and a molecular weight modifier. The mixture is continuously added over 2 to 5 hours to proceed with the polymerization. This allows a small amount of graft monomer and polymerization initiator to participate in the graft reaction at a constant rate. When the addition of the monomer is finished, the reactor temperature is maintained at 70 to 75 ° C. for 20 to 60 minutes and the final polymerization conversion rate is 93 to 98. The secondary graft copolymer latex is prepared by forced cooling to terminate polymerization by%.

(3) Third Step: Preparation of Tertiary Graft Copolymer Latex

In the presence of the second graft copolymer latex prepared by the second step reaction, a water-soluble initiator was added to the reactor at a temperature of 70 to 75 ° C., stirred for 5 to 10 minutes, and then 8 to 25 parts by weight of an aromatic vinyl monomer and cyanide. 2-8 weight part of vinyl monomers and a molecular weight modifier mixture are continuously added over 2 to 5 hours, and superposition | polymerization is advanced. After the addition of monomers, the reactor temperature is maintained for 20 to 60 minutes at 70 to 75 ° C, and the final polymerization conversion reaches 93 to 98% by forced cooling to terminate the polymerization. The tertiary graft has a solid content of 38 to 44%. Copolymer latex is prepared.

The butadiene rubbery polymer of the present invention may be a rubbery polymer latex containing a gel content of 70 to 80% by weight or more. The average particle diameter is in the range of about 0.20 to 0.33 μm, and the content of the rubbery polymer is 30 to 30 based on the solid content. A range of 50 parts by weight is preferred.

In the monomers used in the present invention, aromatic vinyl (styrene-based) monomers include side-chain alkyl substituted styrenes such as styrene, α-ethylstyrene and α-methylstyrene, and nuclear alkyl substitutions such as p-methylstyrene and ot-butylstyrene. Styrene and the like, of which styrene is most preferred.

Acrylonitrile or methacrylonitrile is used as the vinyl cyanide (acrylonitrile-based) monomer, and acrylonitrile is preferably used.

The acrylate monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate and the like, of which methyl methacrylate is most preferred.

The present invention uses a fat-soluble pyrolysis polymerization initiator and a water-soluble pyrolysis initiator in the polymerization initiator to produce a graft copolymer. By using a fat-soluble pyrolysis polymerization initiator in the first step to effectively react the monomers introduced in the first graft polymerization reaction in the rubbery polymer to express excellent impact resistance, and by using a water-soluble polymerization initiator in the second and third steps It has excellent fluidity and appearance.

The fat-soluble pyrolysis polymerization initiator used in the first step graft reaction is acetyl chlorohexylsulfonyl peroxide, 2-2 'azobis-2,4-dimethylvaleronitrile, 2-2'azobis- (2 -Amidinopropane) dihydrochloride, lauloyl peroxide, 2-2'-azobisisobutylonitrile, benzoyl peroxide, dimethyl-2,2'-azobisisobutylonitrile, 4,4'-azo It is preferable to use one kind of polymerization initiator selected from bis-4-cyanovaleric acid and the like, and more preferably from 0.05 to 0.2 parts by weight of 2-2'-azobisisobutylonitrile having a relatively low decomposition temperature is used. It is good.

As the water-soluble polymerization initiator used in the second and third graft reactions, it is preferable to use one kind of polymerization initiator selected from potassium persulfate, sodium persulfate, ammonium persulfate, etc., and the amount is 0.2 to 0.5 parts by weight. Good to do.

Emulsifiers usable in the present invention include fatty acid metals such as sodium laurate, sodium oleate, potassium oleate, potassium stearate, sodium lauryl sulfate, potassium rosinate and the like. Of these, potassium stearate or potassium rosinate is preferably used alone or in combination. The amount of these used is preferably 0.3 to 1.5 parts by weight.

As the molecular weight modifier used in the present invention, it is possible to use one or two or more mixtures of mercaptans having 8 to 18 carbon atoms or an organic activating compound and one or more selected from alphamethylstyrene duplexes, tepinolene and alpha terpinene. It is preferable that their amount is preferably 0.01 to 0.2 parts by weight.

The graft copolymer latex prepared according to the present invention is coagulated with an aqueous acid solution and then dehydrated and dried to obtain a graft copolymer in powder form.

According to the above method, a graft copolymer white powder is obtained, and then mixed with a separately prepared SAN resin to prepare an ABS thermoplastic resin having excellent natural color and excellent surface gloss. At this time, the SAN resin to be used as a matrix uses a resin produced by the continuous bulk polymerization method which is a conventional manufacturing method.

In the mixing of the graft copolymer and the SAN resin, the content of the graft copolymer is 10 to 40% by weight and the content of the SAN resin is 60 to 90% by weight, and then extruded by adding a stabilizer and a lubricant. And an ABS resin composition of injection molding.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1

(1) First step

(Iii) 50 parts by weight of butadiene rubbery latex having an average particle diameter of 0.30 µm and a gel content of 82% in a 30 L reactor equipped with a stirrer, heating device, cooling device, condenser, monomer and graft monomer continuous feeding device And 130 parts of ion-exchanged water, 1 part of potassium rosinate, 8.5 parts of styrene, 4.5 parts of acrylonitrile and 0.1 part of dodecylmercaptan, and then heated to 60 ° C while stirring.

(Ii) When the temperature of the mixture reaches 60 ° C, the mixture is continuously stirred for 10 minutes, and then a solution of 2 parts of styrene and 0.1 part of 2-2'-azobisisobutylonitrile is added thereto, and the temperature is adjusted to 70 ° C after 50 minutes. It was. When the temperature of the mixture reached 70 ℃ polymerization was continued for 60 minutes, the reaction was cooled and terminated to prepare a primary graft latex.

(2) second stage

In the presence of the prepared first graft latex, the temperature was maintained at 70 ° C., 0.2 parts of sodium persulfate was added thereto, stirred for 10 minutes, and 15 parts of separately prepared methyl methacrylate and 0.05 parts of dodecyl mercaptan were mixed in a graft monomer for 3 hours. Was added continuously. When the addition of the monomer solution was completed, the secondary graft latex was prepared by cooling and terminating the reaction maintaining the reactor internal temperature for 60 minutes.

(3) Third step

In the presence of the prepared secondary graft latex, the temperature was maintained at 70 ° C., 0.3 parts of sodium persulfate was added thereto, stirred for 10 minutes, and a graft monomer mixed with 14 parts of styrene, 6 parts of acrylonitrile, and 0.1 part of dodecylmercaptan prepared separately. Was added continuously for 4 hours. When the monomer solution was added, tertiary graft latex was prepared by cooling and terminating the reaction maintaining the reactor internal temperature for 60 minutes.

The graft copolymer latex thus obtained had a total conversion of 98%, a solid content of 42%, and a graft rate of 45%.

The graft latex was filtered through a mesh of # 200, solidified at 85 ° C. with an aqueous solution of 1.0% sulfuric acid, washed, and dried to obtain a white powder.

25 parts by weight of the graft copolymer white powder obtained by the above method and 75 parts by weight of the SAN resin were mixed, 0.4 parts by weight of magnesium stearate as a stabilizer, and 1 part by weight of ethylene bis stearamide were added and mixed, followed by using a twin extruder. The physical property results obtained by injection molding after injection molding to prepare the test specimen for measuring the physical properties are shown in Table 1 below.

Example 2

In preparing the first step graft copolymer, 30 parts of butadiene rubber latex, 10.5 parts of styrene monomer and 4.5 parts of acrylonitrile monomer are added, and 30 parts of methyl methacrylate monomer is added in step 2, and styrene is obtained in step 3. The same procedure as in Example 1 was carried out except that 17.5 parts of the monomer and 7.5 parts of the acrylonitrile monomer were added thereto.

Example 3

The preparation of the second graft copolymer was carried out in the same manner as in Example 1, except that 15 parts of butyl acrylate was added instead of the methyl methacrylate monomer.

Example 4

The same procedure as in Example 1 was carried out except that the α-methyl styrene monomer was added instead of the styrene monomer during the preparation of the first and third copolymers.

Comparative Example 1

In the second step graft copolymer was prepared in the same manner as in Example 1, except that 10.5 parts of styrene monomer and 4.5 parts of acrylonitrile monomer were added instead of the methyl methacrylate monomer.

Comparative Example 2

The third step was carried out in the same manner as in Example 1 except that 20 parts of methyl methacrylate was added instead of the styrene monomer and acrylonitrile monomer when preparing the graft copolymer.

Comparative Example 3

Butadiene rubbery latex was prepared in the same manner as in Example 1 except that the average particle diameter of butadiene rubbery latex was used in the preparation of the first step graft copolymer.

The results in Examples 1-4 and Comparative Examples 1-3 are shown in Table 1 below.

Example Comparative Example One 2 3 4 One 2 3 Whiteness, ASTM D1925 83.5 84.6 82.4 81.3 75.2 87.6 83.7 Yellowness, ASTM D1925 10.2 9.5 10.8 12.4 14.8 9.1 12.3 Glossiness, ASTM D523 95.8 97.5 92.4 93.5 93.4 70.3 98.7 Notched Izod Impact Strength (1/4 ″), ASTM D256㎏.㎝ / ㎝, 23 ℃) 22.2 15.5 24.5 16.7 29.2 14.5 6.5

As described above, according to the production method of the present invention, a thermoplastic acrylonitrile-butadiene-styrene (ABS) resin having excellent whiteness and surface glossiness can be obtained through emulsion polymerization.

The present invention has the effect of providing a thermoplastic acrylonitrile-butadiene-styrene (ABS) resin having excellent whiteness and surface glossiness through emulsion polymerization.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (8)

30 to 50 parts by weight of butadiene rubbery latex having an average particle diameter of 0.2 to 0.33 µm was added to the reactor with an aromatic vinyl monomer and a vinyl cyanide monomer. A first step of preparing a first graft copolymer latex by adding a fat-soluble initiator; A second step of preparing a second graft copolymer latex by adding and polymerizing an acrylate monomer mixture, a water-soluble initiator, and a molecular weight regulator in the presence of the first graft copolymer latex prepared in the first step; And A third step of preparing a tertiary graft copolymer by adding and polymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, a water-soluble initiator and a molecular weight modifier in the presence of the secondary graft copolymer latex; Method for producing an ABS resin having excellent whiteness and surface glossiness, characterized in that consisting of. The method according to claim 1, wherein the aromatic vinyl monomer used in the first and third steps is selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, p -methylstyrene, and ot-butylstyrene. The manufacturing method of ABS resin characterized by the above-mentioned. The method of claim 1, wherein the vinyl cyanide monomer used in the first and third steps is acrylonitrile or methacrylonitrile. The method of claim 1, wherein the acrylate monomer used in the second step is selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl acrylate, and butyl acrylate. The fat-soluble initiator used in the first step is acetyl chlorohexylsulfonyl peroxide, 2-2 'azobis-2,4-dimethylvaleronitrile, 2-2' azobis- (2- Amidinopropane) dihydrochloride, lauloyl peroxide, 2-2'-azobisisobutylonitrile, benzoyl peroxide, dimethyl-2,2'-azobisisobutylonitrile, and 4,4'-azo Method for producing an ABS resin, characterized in that selected from the group consisting of bis-4-cyano valeric acid. The method of claim 1, wherein the water-soluble initiator used in the second and third steps is selected from the group consisting of potassium persulfate, sodium persulfate, and ammonium persulfate. ABS resin produced according to any one of claims 1 to 6. An ABS resin composition comprising 10 to 40% by weight of the ABS resin of claim 7 and 60 to 90% by weight of the SAN resin.