KR20100062399A - Method for preparing graft-copolymer latex having good production efficiency - Google Patents

Abstract

PURPOSE: A method for manufacturing graft-copolymer latex is provided to maintain high conversion rate and excellent mechanical property and to improve productivity of the copolymer latex with shortened reaction time. CONSTITUTION: A method for manufacturing graft-copolymer latex comprises: a step of inputting a part of rubber latex to a reactor at 50-70°C; a step of inputting remaining amount of rubber latex to the reactor; a step of inputting hydroperoxide redox initiator, activator, emulsifier, and molecular weight regulator to react; a step of adding remaining amount of monomer mixture, hydroperoxide redox initiator, and emulsifier; and a step of maintaining the reactant at 75°C.

Description

Method for Preparing Graft-copolymer Latex Having Good Production Efficiency

The present invention relates to a method for producing a graft copolymer latex having high productivity and high production efficiency while maintaining high conversion rate and excellent mechanical properties. More specifically, a butadiene-based rubber latex seed is introduced through a heat exchanger and polymerization can be carried out simultaneously. The present invention relates to a method for preparing graft copolymer latex by batch or continuous administration of an aromatic vinyl monomer and a vinyl cyan compound monomer when administered at a temperature which can be administered and at about 10% by weight of rubber latex.

The graft copolymer latex prepared according to the present invention was mixed with a styrene-acrylonitrile copolymer prepared by continuous emulsion polymerization in a predetermined ratio to prepare a powder by a conventional method, and then used bulk styrene-acrylonitrile. The copolymer resin of the present invention can be prepared by acrylonitrile-butadiene-styrene (hereinafter referred to as 'ABS') copolymer resin which is excellent in mechanical properties such as impact resistance and tensile strength and natural color by extrusion and injection molding.

In order to disperse the rubber component in the acrylonitrile-styrene resin, such an ABS resin may be dissolved in a monomer acrylonitrile, styrene and a solvent and polymerized in a solution to the rubber latex prepared by emulsion polymerization. A graft copolymer is prepared by grafting acrylonitrile and styrene, and there is a method of mixing and processing a styrene-acrylonitrile resin prepared by separate solution polymerization.

In the case of the ABS resin manufactured by the solution polymerization method, it has mass production and relatively low manufacturing cost, and has excellent color, but it is difficult to manufacture various quality products, and has a problem in that it cannot achieve specialized high added value. In addition, the physical properties such as surface gloss, impact strength, thermal stability, etc. are lowered, so the use thereof is limited, and it is mainly used in combination with ABS resin produced by emulsion polymerization method.

Typically, the ABS resin is prepared by combining a graft copolymer copolymerized with one or two monomers and a styrene copolymer prepared by bulk polymerization or solution polymerization with a rubber latex prepared by emulsion polymerization. ABS resin manufactured by emulsion polymerization method is made of ABS resin, which is the final product through mixing with styrene copolymer prepared by solution polymerization method, despite high manufacturing cost. It has monomer composition and molecular weight which has excellent surface gloss and impact strength. It is made of different different kinds of products.

As the amount of the ABS resin is increased, efforts are being made to increase the yield. In the early stages, the focus was on increasing production facilities. Currently, the company plans to increase production through existing production facilities by 1) shortening the reaction time, 2) increasing rubber content, and 3) improving yields through high conversion rates.

In Korean Patent 10-2001-0072446, after the rubber latex is added, the reaction time is shortened by continuously administering a part of monomers after maintaining or raising the temperature to a certain temperature and simultaneously administering a portion of the monomer, and in Korean Patent 10-2000-0082794, high rubber content Although the graft copolymer having a graft copolymer was produced to improve the productivity of the final ABS product, the gross copolymer powder having a high rubber content had a low apparent specific gravity.

US Pat. No. 4,272,425 and US Pat. No. 4,822858 attempt to increase the yield of the final latex product by adding additional monomers, such as butadiene and acrylonitrile, respectively.

However, the above patents have a disadvantage in that the cycle time of the reaction is lengthened because the time required for the initial rubber latex administration and the temperature rise time to start the reaction are required to prepare the graft copolymer.

In addition, a method of increasing the yield by increasing the total solid content has been proposed, but there is a difficulty in efficient production due to a large amount of polymerized coagulant produced and a decrease in storage stability.

In order to solve the problems of the prior art as described above of the present invention, the rubber can be reacted at the same time with the administration of rubber latex to increase the temperature above a certain temperature through the use of a heat exchanger to reduce the temperature rise time and the level of rubber that can be stirred through the agitator in the reactor. It is an object of the present invention to provide a manufacturing method for shortening the graft copolymer latex production time by adding a monomer and at the same time the monomer is continuously added.

In order to achieve the above object, the present invention in the emulsion polymerization process for graft polymerization of an aromatic vinyl compound and a vinyl cyan compound in rubber latex, a) an average particle diameter of 0.30 ~ 0.35㎛, gel content of 80 ~ 95% by weight While maintaining the rubber latex at 50 to 70 ° C. through the heat exchanger, adding 5% to 30% by weight of rubber latex to the reactor; and b) remaining 60 to 75 parts by weight of rubber latex in the reactor. 15-40% by weight of the monomer mixture consisting of an aromatic vinyl compound and a vinyl cyan compound, 15-40% by weight, a batch or continuous administration together with a hydroperoxide-based redox initiator, an activator, an emulsifier, and a molecular weight modifier. And c) a hydroperoxide-based residue with 25-40 parts by weight of the monomer mixture consisting of an aromatic vinyl compound and a vinyl cyan compound in addition to the reactor. Continuous dosing and reacting a dox initiator and an emulsifier; and d) continuously administering a hydroperoxide-based redox initiator and an emulsifier to the reactor. And e) maintaining the reactant of step d) at 75 ° C. or higher to further react.

In the present invention, the aromatic vinyl compound is at least one selected from the group consisting of styrene, alphamethylstyrene, alphaethylstyrene, and paramethylstyrene, and preferably styrene. In the present invention, the vinyl cyan compound is at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile, preferably acrylonitrile.

In the present invention, the monomer mixed with the aromatic vinyl compound and the vinyl cyan compound may further include a graft copolymerizable monomer mixture, for example maleimide, N-methylmaleimide, N-ethylmaleimide, N- It may further include propylmaleimide, N-phenylmaleimide, methyl methacrylate, methyl acrylate, butyl acrylate, acrylic acid, maleic anhydride, and the like. Preferably less than 50% by weight is included.

In the present invention, the hydroperoxide-based redox initiator is selected from the group consisting of tertiary butyl hydroperoxide, cumene hydroperoxide, isopropylbenzene hydroperoxide, preferably the hydroperoxide-based The redox initiator is added in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the graft copolymer, 30-40% by weight in step b), 40-50% by weight in step c), and the rest in step d). It is preferred to be introduced.

In the present invention, the activator is selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium lirronate, sodium sulfate and the like.

In the present invention, the emulsifier is selected from the group consisting of fatty acid soaps, alkali salts of rosin acids, alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters and the like.

In the present invention, the molecular weight regulator is preferably mercaptans.

The graft copolymer prepared in the present invention is characterized in that the graft ratio is 30% to 45%.

In one aspect of the present invention, a graft polymerized mixture of an aromatic vinyl compound and a vinyl cyan compound in a rubber latex to prepare a 100 parts by weight of the graft body, a) the average particle diameter is 0.30 ~ 0.35㎛, gel content 5 to 15 parts by weight of 80 to 95% by weight of the rubber latex in a batch within 10 minutes at a temperature of 55 ~ 65 ℃ through a heat exchanger; b) 5 to 15 parts by weight of the rubber latex of step a) is added within 10 minutes and then added at 60 to 75 parts by weight while maintaining at 55 to 65 ° C. through a heat exchanger, and at the same time an aromatic vinyl compound is added to the rubber latex. The monomer mixing ratio of the vinyl cyan compound is 70 to 80: 20 to 30 parts by weight of the total monomer mixture of 25 to 40 parts by weight, 15 to 40% by weight, 30 to 40 of 0.1 to 0.5 parts by weight of the hydroperoxide-based redox initiator Initiating the reaction by batch or continuous administration of weight percent, 0.051 to 0.51 parts by weight of activator, 0.1 to 1.0 parts by weight of emulsifier, and 0.1 to 0.5 parts by weight of molecular weight modifier for 30 to 45 minutes; c) The monomer mixing ratio of the aromatic vinyl compound and the vinyl cyan compound is 60 to 85% by weight of the total 25 to 40 parts by weight of the monomer mixture consisting of 70 to 80: 20 to 30 parts by weight, 0.1 to 0.5 parts by weight of hydroperoxide-based redox initiator 40 to 50% by weight, 0.1 to 1.0 parts by weight of the emulsifier is continuously reacted for 1 to 2 hours while maintaining the polymerization temperature at 65 to 80 ℃; d) 10 to 30% by weight of 0.1 to 0.5 parts by weight of the hydroperoxide-based redox initiator and 0.1 to 0.2 parts by weight of the emulsifier are continuously administered for 10 to 30 minutes, and the reaction is continued while maintaining the polymerization temperature at 75 to 80 ° C. Making; And e) further polymerizing at a polymerization temperature of 75 to 80 ° C. for 30 to 60 minutes.

In the present invention, the rubber latex is a butadiene-based rubber, preferably a butadiene-based rubber containing a vinyl monomer copolymerizable with butadiene, such as styrene or acrylonitrile or less 30% by weight or less.

In the present invention, the weight percent or part by weight of the rubber latex is based on the solid rubber contained in the latex.

In addition, the present invention is a thermoplastic resin composition,

a) graft copolymer prepared by the above method;

b) styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization and

c) Styrene-acrylonitrile (bulk SAN) resins prepared by bulk or solution polymerization

It provides an acrylonitrile-butadiene-styrene-based thermoplastic resin composition comprising a.

In the present invention, in the present invention, the rubber content of the graft copolymer 80 to 95% by weight, 5 to 20% by weight of styrene-acrylonitrile (emulsion SAN) prepared by emulsion polymerization, 50 to 65% by weight To prepare an ABS powder having. When manufacturing the ABS powder with rubber content of 65% or more, the apparent specific gravity decreases, which leads to high packaging and logistics costs. The ABS powder with rubber content of 50% or less becomes expensive due to the high powder content in the final ABS product.

It is used together with the bulk SAN and the ABS powder to produce the final ABS product, the type and content of the bulk SAN is determined according to the use, in general, it is good for mechanical properties to use a bulk SAN of 50 to 80% by weight. In the present invention, SAN326 of Kumho Petrochemical was used.

Hereinafter, the present invention will be described in detail.

a) Rubber Latex Input Step

This step is a step of collectively administering 5 to 15 parts by weight of rubber latex having an average particle diameter of 0.30 to 0.35 μm and a gel content of 80 to 95 wt% through a heat exchanger at a temperature of 50 to 70 ° C., more preferably 55 to 65 ° C. The administration time is preferably within 10 minutes so as to shorten the reaction time.

The average particle diameter of the rubber latex is 0.30 ~ 0.35㎛, gel content is preferably 80 to 95% by weight. If the average particle diameter is less than 0.30㎛, there is a problem of lowering the impact strength according to the small rubber particle diameter, if the average particle diameter exceeds 0.35㎛ there is a problem that the surface gloss is lowered, if the gel content is less than 80% by weight surface graft lowering As a result, the overall mechanical properties are lowered, and when it exceeds 95% by weight, the impact strength according to the graft reduction and the glass transition temperature is lowered.

The rubber latex is preferably used as 60 to 75 parts by weight of the total monomers in the graft polymerization, it is preferable to add 5 to 15 parts by weight.

In case of starting with 5 parts by weight or less, it is difficult to stir because the water level is below the position of the stirrer in the reactor, and when 15 parts by weight or more are added, the reaction cycle time is long.

The input temperature of the rubber latex using the heat exchanger is preferably maintained at 50 ~ 70 ℃, more preferably 55 ~ 65 ℃ within 10 minutes. When the reaction temperature is 50 ° C. or lower, the reaction time may be long due to a low reaction temperature. When the reaction temperature is 70 ° C. or higher, it is difficult to control the process due to a lot of reaction heat in the subsequent reaction initiation step.

b) reaction initiation step

5 to 15 parts by weight of the rubber latex of step a) is added to within 10 minutes and then maintained at 50 to 70 ℃, more preferably 55 to 65 ℃ through a heat exchanger to add 45 to 70 parts by weight of the total monomer 100 parts by weight 60 to 75 parts by weight, and at the same time as the addition of rubber latex monomer mixture consisting of i) a) aromatic vinyl compound and b) vinyl cyan compound ii) hydroperoxide-based redox initiator, iii) activator, iv) Emulsifier, v) initiating the reaction by batch or continuous administration of the molecular weight modifier for 30 to 45 minutes.

The total content of the rubber latex is preferably included in 60 to 75 parts by weight, when less than 60 parts by weight, there is a problem that the production cost is high because the efficiency of the thermoplastic resin is low, and when it exceeds 75 parts by weight can be grafted There is a problem that the graft ratio is lowered because the amount of the monomer is insufficient.

As the aromatic vinyl compound of i) a), styrene, alphamethylstyrene, or paramethylstyrene may be used, and in particular, styrene is preferably used.

The cyan compound of i) b) may be acrylonitrile, ethacrylonitrile, or the like, and particularly preferably acrylonitrile.

It is preferable to mix and use the monomer mixture ratio of the said aromatic vinyl compound and a vinyl cyan compound in 70-80: 20-30 weight ratio. When the vinyl cyan compound is less than 20 parts by weight, it is difficult to knead when mixing with the SAN resin produced by bulk or solution polymerization, and the impact strength is remarkably decreased. When the vinyl cyan compound is more than 30 parts by weight, it is also produced by bulk or solution polymerization. Kneading with the SAN is difficult, and there is a problem that the natural color becomes yellow.

As mentioned above, the monomer mixture which consists of an aromatic vinyl compound and a vinyl cyan compound is a maleimide, N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-phenyl maleimide, methyl methacrylate other than the said component. , Vinyl monomers such as methyl acrylate, butyl acrylate, acrylic acid, maleic anhydride, or mixtures thereof can be further used. At this time, it can be used in a small amount in the vinyl monomer mixture.

The monomer mixture of i) is preferably included in 15 to 40% by weight (3.75 to 16 parts by weight) of 25 to 40 parts by weight based on 100 parts by weight of the total monomer used in the graft copolymer. If it is less than 15% by weight (3.75 parts by weight) there is a problem of lowering the mechanical properties, when it exceeds 40% by weight there is a problem that the control of reaction heat is difficult.

The hydroperoxide-based redox initiator of ii) is included in 30 to 40% by weight (0.03 to 0.2 parts by weight) of 0.1 to 0.5 parts by weight based on 100 parts by weight of the total monomers used in preparing the graft copolymer. desirable. If the content is less than 30% by weight (0.03 parts by weight), there is a problem that the graft is lowered. When the content is more than 40% (0.2 parts by weight), the graft copolymer of a low molecular weight is produced to decrease the mechanical properties There is a problem.

As the hydroperoxide-based redox initiator of ii), organic peroxides such as tertiary butyl hydroperoxide, cumene hydroperoxide and isopropylbenzene hydroperoxide, and inorganic peroxides such as potassium persulfate salt and sodium persulfate salt are used alone. Or mixed.

The activator of iii) may be used together with the hydroperoxide-based redox initiator of ii) to enable polymerization even at 50 ° C or below, and to promote the polymerization reaction according to the amount used, and to improve the graft rate. It works.

The activating agent may be sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium lirroline, or sodium sulfate, preferably lactose, sodium pyrrolate And ferrous sulfate.

The activator is preferably included in a total of 0.051 to 0.51 parts by weight based on 100 parts by weight of the total monomer used in the graft copolymer, more preferably 0.03 to 0.3 parts by weight of lactose, 0.02 to 0.2 parts by weight of sodium phosphate Parts and 0.001 to 0.01 parts by weight of ferrous sulfate. If the content is less than 0.051 or more than 0.51, there is a problem that it is difficult to balance the mechanical properties.

The emulsifier of iv) may be a fatty acid soap or an alkali salt of rosin acid, alkyl aryl sulfonate, alkali methyl alkyl sulfate, sulfonated alkyl ester and the like.

The emulsifier is preferably included 0.1 to 1.0 parts by weight based on 100 parts by weight of the total monomer used in the graft copolymer production.

Mercaptans may be used as the molecular weight regulator of v), and in particular, tertiary dodecyl mercaptan is preferably used.

The molecular weight modifier is preferably included in 0.1 to 0.5 parts by weight based on 100 parts by weight of the total monomer used in the graft copolymer production.

c) continuous administration and reaction of monomers

This step is a step in which all the additives of step b) is administered and at the same time the monomers consisting of aromatic vinyl compounds and vinyl cyan compounds, hydroperoxide-based redox initiators, emulsifiers are continuously reacted.

Specifically, the monomer mixing ratio of the aromatic vinyl compound and the vinyl cyan compound is 60 to 85% by weight (15 to 34 parts by weight) of the total 25 to 40 parts by weight of the monomer mixture consisting of 70 to 80: 20 to 30 parts by weight, hydro 40 to 50% by weight (0.04 to 0.25 parts by weight) of 0.1 to 0.5 parts by weight of the peroxide-based redox initiator, 0.1 to 1.0 parts by weight of the emulsifier is continuously administered for 1 to 2 hours while maintaining the polymerization temperature at 65 to 80 ℃ Let's do it.

Of course, each component used in this step may use the same components as described in step b) above.

d) further administration of initiator and emulsifier

This step is a step of further continuous administration of the hydroperoxide-based redox initiator, emulsifier to the reactant in step c).

Specifically, the step is 10 to 30% by weight (0.01 to 0.15 parts by weight) of 0.1 to 0.5 parts by weight of the hydroperoxide-based redox initiator, 0.1 to 0.2 parts by weight of the emulsifier continuously for 10 to 30 minutes, the polymerization temperature It is a step of continuing the reaction while maintaining a 75 ~ 80 ℃.

Of course, each component used in this step may use the same components as described in step b) above.

e) further reaction steps

This step is a step of further polymerizing the reactant of step d) at a polymerization temperature of 75 to 80 ° C. for 30 to 60 minutes. At this time, the polymerization is terminated when the conversion of the monomer is 99% or more.

The graft copolymer latex of the present invention is mixed with an emulsified SAN latex prepared by emulsion polymerization in an amount of 85 to 95% by weight: 5 to 15% by weight of a conventional flocculant, sulfuric acid, MgSO ₄ , CaCl ₂ , or Al ₂ (SO ₄ ). After coagulation with ₃ or the like, it can be washed, dehydrated and dried to obtain a powdered graft copolymer.

The final graft ratio of the graft copolymer of the present invention prepared by the above method is preferably 25% or more, more preferably 30% to 45%.

The present invention also provides a thermoplastic resin composition comprising a graft copolymer prepared as described above and a styrene-acrylonitrile (bulk SAN) resin prepared by bulk or solution polymerization.

The graft copolymer prepared by the above method is preferably included in 20 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition, the impact strength is lowered when the content is less than 20 parts by weight, when it exceeds 50 parts by weight There is a problem that workability and surface gloss decrease.

According to the manufacturing method of the present invention as described above, it is possible to significantly improve the productivity by shortening the initial process time and reaction time while maintaining high conversion and excellent mechanical properties.

According to the present invention, in manufacturing the graft copolymer latex, it is possible to significantly improve the graft copolymer latex productivity by reducing the polymerization cycle time while maintaining high conversion and excellent mechanical properties.

Example 1

In a nitrogen-substituted polymerization reactor, 7 parts by weight of rubber latex having an average particle diameter of 0.33 μm and a gel content of 85% were introduced through a heat exchanger at 62 ° C. for 10 minutes, followed by 58 parts by weight of rubber latex, 8.25 parts by weight of styrene, and acryl. Nitrile 2.75 parts by weight, tertiary butyl hydroperoxide 0.1 parts by weight, lactose 0.12 parts by weight, sodium pyrrolate 0.05 parts by weight, ferrous sulfide 0.002 parts by weight, potassium oleate 0.35 parts and tertiary dodecyl mercaptan 0.2 parts by weight Part was administered continuously or batch for 45 minutes, after 45 minutes the temperature in the reactor was 65 ℃.

Since 18 parts by weight of styrene, 6 parts by weight of acrylonitrile, 0.085 tertiary butyl hydroperoxide, 0.5 parts by weight of potassium oleate were continuously administered for 90 minutes. At this time, the reaction temperature was raised from 65 ℃ to 75 ℃. After continuous administration, 0.015 parts of tertiary butyl hydroperoxide and 0.1 parts by weight of potassium oleate were continuously added for 15 minutes, and the polymerization temperature was maintained at 75 ° C. The graft copolymer was aged for 60 minutes to have a monomer conversion rate of 99% or more. Latex was obtained.

The graft rate of the polymerized graft copolymer latex was 35%, the polymerization conversion was 99.5%, and the polymerization coagulum was 0.01%.

Then, a graft copolymer latex having a rubber content of 60% was prepared by mixing an emulsified SAN in a ratio of 92.3: 7.7 to the polymerization latex, aggregated with MgSO ₄ , and dried to obtain a graft copolymer resin in powder form.

The graft rate is 2g of powdered graft copolymer resin with 100 mL of acetone for 24 hours to dissolve the grafted styrene copolymer in the rubber component, and then separate the gel and the sol by ultracentrifugation in accordance with Equation 1 Calculated.

[Equation 1]

Graft Rate = [(gel-rubber weight)] / rubber weight] x100

Examples 2 to 3

The graft copolymer was prepared by the same composition as in Example 1, but converted to the method as shown in Table 1 below. (However, the additional administration step of the initiator and the emulsifier and the additional reaction step are not shown the same)

[Comparative Example]

Comparative Example 1

 The graft copolymer was prepared in the same manner as in Example 1 except that the rubber latex was administered at 40 ° C. without using a heat exchanger.

Comparative Example 2

A graft copolymer was prepared in the same manner as in Example 1 except that all 65 parts by weight of rubber latex were administered.

Comparative Example 3

Graft copolymer was prepared in the same manner as in Example 1, except that the rubber latex contained all of 65 parts by weight of the rubber latex at 40 ° C. without using a heat exchanger and the temperature was increased to 60 ° C.

Comparative Example 4

Graft copolymer in the same manner as in Example 1 except for administering all of the rubber latex 65 parts by weight of the rubber latex at 40 ℃ without using a heat exchanger and the temperature of 60 ℃, the monomer continuous addition in 60 minutes Was prepared.

TABLE 1

Example 1 Example 2 Example 3 Comparative example
One Comparative example
2 Comparative example
3 Comparative example
4 Rubber Latex Input Step heat transmitter
Temperature 62 ℃ 62 ℃ 62 ℃ use
Never
40 ℃ 62 ℃ use
Never
40 ℃ use
Never
40 ℃ Rubber Latex
Parts by weight 7 14 7 7 65 65 65 time 10 minutes 20 minutes 10 minutes 10 minutes 80 minutes 120 minutes 120 minutes reaction
Start
step Gomo Larex
Parts by weight 58 51 58 58 0 58 58 Styrene 8.25 8.25 11.25 8.25 8.25 8.25 8.25 Acrylonitrile 2.75 2.75 3.75 2.75 2.75 2.75 2.75 Initiator TBHP ¹⁾
0.1 TBHP
0.1 CHP ²⁾
0.1 TBHP
0.1 TBHP
0.1 TBHP
0.1 TBHP
0.1 Potassium oleate 0.35 0.35 0.35 0.35 0.35 0.35 0.35 Activator 0.172 0.172 0.172 0.172 0.172 0.172 0.172 time 45 minutes 30 minutes 45 minutes 45 minutes 45 minutes 45 minutes 45 minutes Monomeric
Continuous administration
step Styrene 18 18 15 18 18 18 18 Acrylonitrile 6 6 5 6 6 6 6 Initiator TBHP
0.085 TBHP
0.085 CHP
0.085 TBHP
0.085 TBHP
0.085 TBHP
0.085 TBHP
0.085 Time (min) 90 90 90 90 90 90 60 Total reaction cycle time (minutes) 210 205 210 210 280 320 290 % Conversion of monomer 99.5 99.4 99.6 98.1 99.2 99.5 99.5 Graft Rate (%) 35 33 35 22 34 35 26

* TBHP ¹⁾ : tertiary butyl hydroperoxide

CHP ²⁾ : cumene hydroperoxide

In Comparative Examples 1 to 4, when the weight of the rubber latex is added at the same time, the time required for the completion of the reaction when the reaction is started takes 60 minutes, and the time for raising the reaction temperature to 60 ° C. without using a heat exchanger is required at least 40 minutes. It was confirmed that the total reaction cycle time at least 30% longer than the method prepared in Examples 1 to 3.

25 parts by weight of the graft copolymer resin prepared in Examples 1 to 3 and Comparative Examples 1 to 3, 75 parts by weight of a SAN resin having a weight average molecular weight of 100,000 and an acrylonitrile content of 25% and a lubricant 0.75, a heat stabilizer 0.25 After adding the parts by weight and mixing, extrusion and injection molding to prepare a specimen that is 15% by weight of the final rubber. Using the specimen, Izod impact strength, tensile strength and flow index were measured by the following method, and the results are shown in Table 2 below.

A) Izod impact strength test: measured according to the method of ASTM D256. At this time, the thickness of the specimen was 1/4 inch.

B) Tensile strength: Tensile strength was measured by ASTM D638 method.

C) Melt Flow Index (MI): Measured according to ASTM D1238 under the condition of 220 ° C. and 10 Kg.

TABLE 2

division Example Comparative example One 2 3 One 2 3 4 Izod impact strength
(1/4 "Kgcm / cm) 20 21 20 12 20 21 14 Tensile Strength (kg / ㎠) 490 490 486 475 492 490 472 liquidity
(g / 10min 220 ℃, 10kg) 35 32 34 15 34 35 22

Through Table 2, the thermoplastic resin prepared by using the graft copolymers of Examples 1 to 3 prepared according to the present invention, compared to Comparative Examples 1 to 4, the total reaction cycle time without deterioration in fluidity and packing strength It can be confirmed that the productivity is excellent.

Claims (11)

In the emulsion polymerization step of graft polymerization of an aromatic vinyl compound and a vinyl cyan compound to rubber latex, a) 5% to 30% by weight of rubber latex 60-75 parts by weight of the rubber latex in the reactor while maintaining a rubber latex having an average particle diameter of 0.30 to 0.35 mu m and a gel content of 80 to 95% by weight through a heat exchanger Injecting; b) 60 to 75 parts by weight of the rubber latex into the reactor, 15-40% by weight of 25-40 parts by weight of the monomer mixture consisting of aromatic vinyl compound and vinyl cyan compound, hydroperoxide-based redox initiator, activator, Reacting in batch or continuous administration with an emulsifier and a molecular weight modifier; c) reacting the remainder of the mixture of 25-40 parts by weight of the monomer mixture consisting of an aromatic vinyl compound and a vinylcyan compound with a hydroperoxide-based redox initiator and an emulsifier continuously; d) continuously administering a hydroperoxide-based redox initiator and an emulsifier to the reactor; And e) maintaining the reactant of step d) at 75 ° C. or higher to further react Method for producing a graft copolymer latex comprising a. The method of claim 1, The aromatic vinyl compound is selected from the group consisting of styrene, alpha methyl styrene, alpha ethyl styrene, and paramethyl styrene. The method for producing graft copolymer latex according to claim 1, wherein the vinyl cyan compound is selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile. The method of claim 1, wherein the monomer mixture is maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-phenylmaleimide, methyl methacrylate, methyl acrylate, butyl acrylate, A method for producing a graft copolymer latex further comprising a vinyl monomer selected from the group consisting of acrylic acid and maleic anhydride. The graft copolymer according to claim 1, wherein the hydroperoxide-based redox initiator is selected from the group consisting of tertiary butyl hydroperoxide, cumene hydroperoxide, and isopropylbenzene hydroperoxide. Method of making latex. According to claim 1 or 5, wherein the hydroperoxide-based redox initiator is added to 0.1 to 0.5 parts by weight based on 100 parts by weight of the raft copolymer, in step b) 30-40% by weight c) in step 40 ~ 50% by weight, the method of producing a graft copolymer latex, characterized in that the remainder is added in step d). The method according to claim 1, wherein the activator is selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium liroline, sodium sulfate, and the like. Method for producing a graft copolymer latex, characterized in that. The graphene according to claim 1, wherein the emulsifier is selected from the group consisting of fatty acid soaps, alkali salts of rosin acids, alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters, and the like. Method for producing a latex copolymer latex. The method for producing a graft copolymer latex according to claim 1, wherein the molecular weight regulator is mercaptans. The method according to any one of claims 1 to 9. Method for producing a graft copolymer latex, characterized in that the graft ratio of the graft copolymer is 30% ~ 45%. In the emulsion polymerization step of graft polymerization of an aromatic vinyl compound and a vinyl cyan compound to rubber latex, a) 5-15 parts by weight of a rubber latex having an average particle diameter of 0.30 to 0.35 μm and a gel content of 80 to 95 wt% in a batch within 10 minutes at a temperature of 55 to 65 ° C. through a heat exchanger; b) 5 to 15 parts by weight of the rubber latex of step a) is added within 10 minutes and then maintained at 55 to 65 ° C. through a heat exchanger to add 45 to 70 parts by weight to add 60 to 75 parts by weight of 100 parts by weight of the total monomers. At the same time as the addition of rubber latex, the monomer mixing ratio of the aromatic vinyl compound and the vinyl cyan compound is 15 to 40% by weight of the total 25 to 40 parts by weight of the monomer mixture consisting of 70 to 80: 20 to 30 parts by weight, and hydroperoxide-based redox. 30 to 40% by weight of the initiator, 0.1 to 0.51 parts by weight of the activator, 0.051 to 0.51 parts by weight of the activator, 0.1 to 1.0 parts by weight of the emulsifier, and 0.1 to 0.5 parts by weight of the molecular weight modifier for 30 to 45 minutes Initiating; c) The monomer mixing ratio of the aromatic vinyl compound and the vinyl cyan compound is 60 to 85% by weight of the total 25 to 40 parts by weight of the monomer mixture consisting of 70 to 80: 20 to 30 parts by weight, 0.1 to 0.5 parts by weight of hydroperoxide-based redox initiator 40 to 50% by weight, 0.1 to 1.0 parts by weight of the emulsifier is continuously reacted for 1 to 2 hours while maintaining the polymerization temperature at 65 to 80 ℃; d) 10 to 30% by weight of 0.1 to 0.5 parts by weight of the hydroperoxide-based redox initiator and 0.1 to 0.2 parts by weight of the emulsifier are continuously administered for 10 to 30 minutes, and the reaction is continued while maintaining the polymerization temperature at 75 to 80 ° C. Doing; And e) further polymerizing at a polymerization temperature of 75 to 80 ° C. for 30 to 60 minutes Method for producing a graft copolymer latex comprising a.