KR100385728B1 - Thermop lastic resin composition having superior coloring properties and impact strength and method for preparing the same - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition and a method for producing the same, and more particularly, to a styrene resin composition having excellent impact resistance, glossiness, and colorability, and a method for producing the same.

The present invention comprises a) iii) 40 to 80 parts by weight of rubber latex having a gel content of 80% by weight or more and an average particle size of 2500 to 3500 mm by agglomerating small-diameter rubber latex having an average particle diameter of 700 to 1500 mm 3; And ii) 20 to 50 parts by weight of an ABS copolymer having a weight average molecular weight of 75000 or more, including 20 to 60 parts by weight of a monomer mixture comprising 28 to 40% by weight of a vinylcyan compound and 60 to 72% by weight of an aromatic vinyl compound; And b) 50 to 80 parts by weight of a styrene-acrylonitrile copolymer having an molecular weight of 80000 to 100000 and an acrylonitrile content of 24 to 30% by weight, and a thermoplastic resin composition having excellent impact resistance and colorability and a method of manufacturing the same.

The composition of the present invention is a stable polymer having a high graft rate, a weight average molecular weight and low coagulum, and is colored by polymerizing with styrene-acrylonitrile (SAN) having a similar weight average molecular weight and acrylonitrile (AN) content. And providing a thermoplastic resin excellent in impact resistance.

Description

Thermoplastic resin composition excellent in impact resistance and coloring property and its manufacturing method {THERMOP LASTIC RESIN COMPOSITION HAVING SUPERIOR COLORING PROPERTIES AND IMPACT STRENGTH AND METHOD FOR PREPARING THE SAME}

[Industrial use]

The present invention relates to a thermoplastic resin composition and a method for producing the same, and more particularly, to a styrene resin composition having excellent impact resistance, glossiness, and colorability, and a method for producing the same.

[Private Technology]

Generally, in order to improve the impact resistance of acrylonitrile-butadiene-styrene (ABS) copolymer resin or the like, thermoplastic resins such as styrene-acrylonitrile (SAN) copolymer, polystyrene, polymethylmethacrylate, etc. Graft copolymerization of a rubber latex such as a diene rubber component, that is, a polybutadiene, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer, or the like is used.

However, since rubber added to improve impact resistance has a problem of inferior colorability than SAN, increasing the content of rubbery polymer when manufacturing a high-white ABS resin or a similar resin has an effect on increasing the whiteness of the resin itself. However, there is a problem that causes a decrease in colorability due to a decrease in the weight average molecular weight and the graft rate of the grafted SAN.

It is an object of the present invention to provide a thermoplastic resin composition excellent in impact resistance, glossiness, and colorability, and a method for producing the same, in consideration of the problems of the prior art.

[Means for solving the problem]

The present invention, in order to achieve the above object, in the styrene-based thermoplastic resin composition,

a) i) 40 to 80 parts by weight of a rubber latex having a gel content of at least 80% by weight and an average particle diameter of 2500 to 3500 mm by agglomerating small-diameter rubber latex having an average particle diameter of 700 to 1500 mm 3; And

Ii) 20 to 60 parts by weight of a monomer mixture comprising 28 to 40% by weight of a vinylcyan compound and 60 to 72% by weight of an aromatic vinyl compound

20 to 50 parts by weight of an ABS copolymer having a weight average molecular weight of 75000 or more; And

b) 50 to 80 parts by weight of a styrene-acrylonitrile copolymer having a molecular weight of 80000 to 100000 and an acrylonitrile content of 24 to 30% by weight

It provides a thermoplastic resin composition excellent in impact resistance and colorability comprising a.

In addition, the present invention is a method for producing a styrene-based thermoplastic resin composition,

a) i) 40 to 80 parts by weight of a rubber latex having a gel content of at least 80% by weight and an average particle diameter of 2500 to 3500 mm by agglomerating small-diameter rubber latex having an average particle diameter of 700 to 1500 mm 3;

Ii) 20 to 60 parts by weight of a monomer mixture comprising 28 to 40% by weight of a vinylcyan compound and 60 to 72% by weight of an aromatic vinyl compound;

V) 0.1 to 0.3 parts by weight of initiator;

Iii) 0.5 to 3 parts by weight of an emulsifier; And

Iii) 0.1 to 2 parts by weight of molecular weight modifier

Graft copolymerization for 4 hours to prepare an ABS copolymer having a weight average molecular weight of at least 75000; And

b) ⅰ) 20 to 50 parts by weight of the ABS copolymer of step a); And

Ii) the molecular weight is 80000-100000 and the acrylonitrile content is 24-30% by weight 50 to 80 parts by weight of styrene-acrylonitrile copolymer

Kneading to prepare a thermoplastic resin

It provides a method for producing a thermoplastic resin comprising a.

Hereinafter, the present invention will be described in detail.

[Action]

The thermoplastic resin composition of the present invention grafts a) i) a large diameter rubber latex having a high gel content, ii) a monomer mixture comprising a vinyl cyan compound and an aromatic vinyl compound, iii) an initiator, iii) an emulsifier, and iii) a molecular weight modifier. The copolymer is produced by copolymerization, and the ABS copolymer and b) a styrene-acrylonitrile (SAN) copolymer are kneaded to prepare an ABS copolymer.

The a) iii) large diameter rubber latex is prepared by agglomerating a small diameter rubber latex having an gel content of 90 to 100% by weight and having an average particle diameter of 700 to 1500 mm 3 by acid.

The small-diameter rubber latex may be a polybutadiene, and a copolymer of butadiene and a copolymer capable of copolymerizing butadiene (butadiene content in the copolymer is more than 50% by weight), and the monomer copolymerizable with butadiene is specifically styrene , An aromatic vinyl compound selected from the group consisting of alpha methyl styrene and vinyl toluene, and a vinyl cyan compound selected from the group consisting of acrylonitrile (AN) and methacrylonitrile.

As the agglomeration method of the small-diameter rubber latex, an agglomeration method using an acid is used, and the factors governing the agglomeration degree are an amount of an emulsifier, a pH, a temperature, and an amount of solid content.

The large-diameter rubber latex prepared by the above process has a gel content of 80% by weight or more, a swelling index of 20 or less, and an average particle diameter of 2500 to 3500 mm 3.

At this time, the swelling index and the gel content was solidified rubber latex and washed, dried in a vacuum oven at 40 ℃ for one day, 1 g of the rubber latex in 100 g of toluene and left for 48 hours, the dissolved part It is measured by the weight of the undissolved portion and calculated according to Equations 1 and 2, respectively.

[Equation 1]

[Equation 2]

The a) ii) monomer mixture comprises 28 to 40% by weight vinyl cyan compound, and 60 to 72% by weight aromatic vinyl compound.

As the aromatic vinyl compound, styrene, alphamethylstyrene, or vinyl toluene may be used, and the vinyl cyan compound may be acrylonitrile, methacrylonitrile, or the like.

The a) iii) initiator may be an oil-soluble organic peroxide such as cumene hydroperoxide or diisopropyl benzene hydroperoxide, and a redox catalyst of a reducing agent. In the present invention, since the content of the rubbery polymer is increased in order to increase the whiteness, it is preferable to use cumene hydroperoxide which minimizes polymerization in the aqueous phase in order to graf the relatively small monomers efficiently.

The a) iii) emulsifier may be a rosin salt containing potassium rosin and sodium rosin, a fatty acid salt containing potassium oleate and sodium stearate, or an alkyl aryl sulfonate.

A) iii) the molecular weight modifier is a mercaptans comprising t-dodecyl mercaptan and n-dodecyl mercaptan, terpenes including tabinolten, dipentene and t-tyrphiene, or chloroform and carbon tetrachloride Halogenated hydrocarbons and the like may be used.

The above components include a) iii) 40 to 80 parts by weight of large diameter rubber latex, ii) 20 to 60 parts by weight of monomer mixture, iv) 0.1 to 0.3 parts by weight of initiator, iii) 0.5 to 3 parts by weight of emulsifier, and iii) molecular weight modifier. It is graft copolymerized at the reaction temperature of 60-80 degreeC by the ratio of 0.1-2 weight part.

Specifically, a) i) improved graft rate by continuously introducing a monomer mixture composed of a vinyl cyan compound and an aromatic vinyl compound for about 4 hours using an oil-soluble catalyst as a polymerization initiator in the presence of a large diameter rubber latex. ABS copolymer is prepared.

In the graft copolymerization, the method of adding each component may be divided into a method of administering the total amount of each component at once, a method of dividing the component, a method of continuously adding the total amount or a part of the components, and the like. In the present invention, a method of continuously adding the whole amount of the above methods was performed, and the method of splitting and adding the whole amount at once may be applied to the present invention.

Specifically, in the present invention, the polymerization is carried out by dividing into two or three stages. In the first stage, a rubbery emulsion polymer is added in a batch, and in the second stage, an emulsifier, a monomer, a molecular weight regulator, and water are continuously added into the emulsion. At this time, the initiator is added in a small amount of 0.1 wt% or less in the first step, and 0.1 to 0.3 wt% is continuously added in the second step. In the third step, a small amount of the initiator is added to increase the reaction conversion rate and the temperature is increased by about 10 ° C. than the second step. The oligo reaction is terminated. After the reaction, the latex is coagulated using 25 wt% CaCl ₂ or MgSO ₄ , washed and dried to prepare a powdery ABS copolymer. The graft efficiency was achieved using oil soluble initiators as above and the weight average molecular weight was increased by optimizing the amount of initiator, emulsifier, and molecular weight modifier used.

B) The styrene-acrylonitrile copolymer is prepared by copolymerizing two or more monomers selected from the group consisting of an aromatic mono alkenyl monomer, a vinyl cyan monomer, an acrylic acid alkyl ester monomer, and an alkyl ester monomer of methacrylic acid.

It is necessary to improve the kneading property in order to improve the decrease in colorability due to the decrease in the weight average molecular weight and the graft ratio of the grafted styrene-acrylonitrile copolymer after kneading. As the AN content of the two compounds to be mixed is different, the compatibility index is different from each other, so that the two materials are not mixed well. Therefore, in order to increase the kneading properties when kraft polymers such as ABS copolymers and external SANs are kneaded, the weight average molecular weights and AN contents of the grafted SANs are respectively the weight average molecular weights and AN contents of the SANs of the ABS copolymers. In the present invention, the molecular weight of the a) ABS copolymer and b) SAN copolymer is 80000 to 100000, and the AN content is used in the range of 24 to 30% by weight. When this is satisfied, the resin will exhibit maximum mechanical properties and colorability.

Kneading is carried out using a) 20 to 50 parts by weight of the ABS copolymer, b) 50 to 80 parts by weight of the styrene-acrylonitrile copolymer, and the rubber latex content of the thermoplastic resin prepared by kneading is 10 to 30. Weight percent.

The present invention will be described in more detail with reference to the following examples and comparative examples. However, an Example is for illustrating this invention and is not limited only to these.

EXAMPLE

Example 1

60 parts by weight of a large-diameter rubber latex having an average particle diameter of 2500 to 3500 mm, 145 parts by weight of water were added to a four-necked flask, and 0.09 parts by weight of dextrose, 0.08 parts by weight of sodium pyrrolate, 0.002 parts by weight of ferrous sulfate, and water 3 at 50 ° C. Part by weight, 0.05 part by weight of 80% cumene hydroperoxide was added and polymerized for 1 hour while raising the temperature to 70 ° C.

During the polymerization, 1.2 parts by weight of potassium rosinate, 25 parts by weight of water, 28 parts by weight of styrene monomer, 12 parts by weight of acrylonitrile, 0.3 parts by weight of t-dodecyl mercaptan, and 0.16 parts by weight of cumene hydroperoxide The prepared emulsion was continuously added at a reaction temperature of 70 ° C. to carry out the reaction for a total of 3 hours.

After the polymerization was completed, 2.8 parts by weight of water, 0.08 parts by weight of dextrose, 0.05 parts by weight of sodium pyrolate, 0.001 parts by weight of ferrous sulfate, and 0.05 parts by weight of cumene hydroperoxide were added to the reactor at a time, followed by temperature of 80 The temperature was raised to 1 ° C. over 1 hour and then the reaction was terminated. At this time, the reaction conversion rate was 99%. An antioxidant was added thereto, followed by coagulation with a 25 wt% magnesium sulfate aqueous solution, followed by washing and drying to obtain a powdery ABS copolymer.

A thermoplastic resin was prepared by adding SAN and a lubricant having a weight average molecular weight of 100000 and an acrylonitrile content of 28% by weight, and then extruding at 220 ° C. The prepared thermoplastic resin was injection molded to prepare a specimen having a final rubber latex content of 14% by weight, and the specimen was left at room temperature for 24 hours, and then measured in physical properties.

In this case, the Izod impact strength is a 1/4 "thickness of the specimen according to ASTM D256 method, the tensile strength is ASTM D638 method, and the Melt Flow Index (MI) is ASTM D1238 under the condition of 220 ℃ and 10 Kg. Method, surface gloss was measured by ASTM D528 method at an angle of 45 °, and colorability was measured using a color computer (SUGA Color Computer) to measure the degree of coloring of 0.06 phr of colorant based on green, which is sensitive to human eyes. The values of a and b represent green and red, and the larger the value, the stronger the green.The graft ratio is obtained by dissolving the prepared graft copolymer powder in acetone for 24 hours and then centrifuging at low temperature. Solids were separated using a separator, and the separated solids were dried to obtain a graft rate according to the following Equation 3. In addition, the portion dissolved in acetone was immersed using water. Which was then re-dissolved in tetrahydrofuran (THF) to measure the weight average molecular weight.

[Equation 3]

Coagulum was expressed by weight percent based on the total solids and monomers administered during the reaction by filtering and drying the coagulum to 50 mesh net after the reaction. Latex stability was measured by the time the coagulation is produced when 400 g of latex in a 1000 ml beaker and stirred at a speed of 10000 rpm using a homo mixer. It was judged that there was no problem in the latex stability when more than 60 minutes.

Example 2

60 parts by weight of large-diameter rubber latex having an average particle diameter of 2500 to 3500 mm, 147 parts by weight of water, 7 parts by weight of styrene, 3 parts by weight of acrylonitrile, 0.3 parts by weight of t-dodecyl mercaptan, and 0.4 parts by weight of potassium rosinate. Into the flask, 0.05 parts by weight of dextrose, 0.04 parts by weight of sodium pyrolate, 0.001 parts by weight of ferrous sulfate, 1.5 parts by weight of water, and 0.08 parts by weight of 80% cumene hydroperoxide, were heated to 70 ° C for 1 hour. Polymerization was carried out.

Next, an emulsion consisting of 0.8 parts by weight of potassium rosin acid, 30 parts by weight of water, 21 parts by weight of styrene monomer, 9 parts by weight of acrylonitrile, and 0.5 parts by weight of 80% t-butylhydroperoxide was continuously added thereto, and the reaction temperature was maintained for 2 hours. It was added while maintaining 70 ℃.

After the polymerization was completed, 1.0 part by weight of water, 0.025 part by weight of dextrose, 0.02 part by weight of sodium pyrolate, 0.0005 part by weight of ferrous sulfate, and 0.05 part by weight of cumene hydroperoxide were added to the reactor at a time, and then the temperature was 80. The temperature was raised to 1 ° C. over 1 hour and then the reaction was terminated. The reaction conversion rate at this time was 98%. An antioxidant was added thereto, followed by coagulation with a 25 wt% magnesium sulfate aqueous solution, followed by washing and drying to obtain a graft copolymer of powder.

In addition, a thermoplastic resin was prepared by extrusion after adding a weight average molecular weight of 100000 and an acrylonitrile content of 28 wt% SAN and a lubricant. Injection molding the prepared thermoplastic resin to prepare a specimen with a final rubber content of 14% by weight and measured the physical properties in the same manner as in Example 1 and the results are shown in Table 1.

Example 3

In the same manner as in Example 1, a thermoplastic resin was prepared by adding SAN and a lubricant having a weight average molecular weight of 100000 and an acrylonitrile content of 28% by weight and adding a lubricant. Injection molding the prepared thermoplastic resin to prepare a specimen with a final rubber content of 16% by weight and measured the physical properties in the same manner as in Example 1 and the results are shown in Table 1.

Comparative Example 1

30.4 parts by weight of styrene, 9.6 parts by weight of acrylonitrile, 0.4 parts by weight of t-dodecyl mercaptan, 0.15 parts by weight of 80% cumene hydroperoxide, and 1.13 parts by weight of potassium rosinate were used. A thermoplastic resin was prepared by extruding SAN and a lubricant having a weight average molecular weight of 120,000 and an acrylonitrile content of 28% by weight. Injection molding the prepared thermoplastic resin to prepare a specimen with a final rubber content of 16% by weight and measured the physical properties in the same manner as in Example 1 and the results are shown in Table 1.

Comparative Example 2

The polymerization was carried out in the same manner as in Example 1 to prepare a graft copolymer, and a thermoplastic resin was prepared by adding SAN and a lubricant having a weight average molecular weight of 100,000 and an acrylonitrile content of 24% by weight and adding a lubricant. Injection molding the prepared thermoplastic resin to prepare a specimen with a final rubber content of 14% by weight and measured the physical properties in the same manner as in Example 1 and the results are shown in Table 1.

TABLE 1

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 AN content in weight% 30 30 30 24 30 Weight average molecular weight of SAN 100000 100000 100000 120000 100000 AN content (% by weight) in SAN 28 28 28 28 24 Weight average molecular weight of polymer 75500 76000 75500 65500 75500 Rubber content (% by weight) of polymer 14 14 16 16 14 Latex stability (min) 60 60 or more 60 15 60 Izod impact strength (㎏㎝ / ㎝) 22.1 22.7 20.7 20.7 21.5 Liquidity Index (g / 10min) 24 22.5 22.1 21 22.3 Tensile Strength (kg / cm 3) 520 523 502 510 513 Surface gloss (%) 105 100 101 98 100 Colorability (a) -45.64 -44.52 -44.23 -42.85 -42.34 Graft Rate (%) 32.5 32.0 32.5 21.2 32.5 Coagulation after completion of reaction (%) 0.021 0.028 0.021 0.041 0.021

Comparing the physical properties shown in Table 1 above, the resin compositions of Examples 1 to 3 according to the present invention are stable polymers having a higher graft ratio and weight average molecular weight and less coagulum than the resin compositions of Comparative Examples 1 to 2, and also have coloring properties, It turned out that glossiness and impact resistance are excellent.

The composition of the present invention is a stable polymer having a high graft rate, a weight average molecular weight, and a small amount of coagulum. Has the effect to provide.

Claims (16)

a) i) 40 to 80 parts by weight of a rubber latex having a gel content of at least 80% by weight and an average particle diameter of 2500 to 3500 mm by agglomerating small-diameter rubber latex having an average particle diameter of 700 to 1500 mm 3; And Ii) 20 to 60 parts by weight of a monomer mixture comprising 28 to 40% by weight of a vinylcyan compound and 60 to 72% by weight of an aromatic vinyl compound 20 to 50 parts by weight of an ABS copolymer having a weight average molecular weight of 75000 or more; And b) 50 to 80 parts by weight of a styrene-acrylonitrile copolymer having a molecular weight of 80000 to 100000 and an acrylonitrile content of 24 to 30% by weight High impact resistance and colorability thermoplastic resin composition comprising a. The method of claim 1, The thermoplastic resin composition has a weight average molecular weight of 75000 or more and a graft ratio of 25% or more. The method of claim 1, A thermoplastic resin composition having excellent impact resistance and colorability, wherein the aromatic vinyl compound of a) ii) is selected from the group consisting of styrene, alphamethylstyrene, and vinyl toluene. The method of claim 1, The thermoplastic resin composition excellent in impact resistance and coloring property whose said vinyl cyan compound of a) ii) is acrylonitrile or methacrylonitrile. The method of claim 1, The styrene-acrylonitrile copolymer of b) is prepared by copolymerizing two or more monomers selected from the group consisting of an aromatic mono alkenyl monomer, a vinyl cyan monomer, an acrylic acid alkyl ester monomer, and an alkyl ester monomer of methacrylic acid. Thermoplastic resin composition excellent in impact resistance and colorability. In the manufacturing method of the thermoplastic resin composition excellent in impact resistance and coloring property, a) i) 40 to 80 parts by weight of a rubber latex having a gel content of at least 80% by weight and an average particle diameter of 2500 to 3500 mm by agglomerating small-diameter rubber latex having an average particle diameter of 700 to 1500 mm 3; Ii) 20 to 60 parts by weight of a monomer mixture comprising 28 to 40% by weight of a vinylcyan compound and 60 to 72% by weight of an aromatic vinyl compound; V) 0.1 to 0.3 parts by weight of initiator; Iii) 0.5 to 3 parts by weight of an emulsifier; And Iii) 0.1 to 2 parts by weight of molecular weight modifier Graft copolymerization for 4 hours to prepare an ABS copolymer having a weight average molecular weight of at least 75000; And b) ⅰ) 20 to 50 parts by weight of the ABS copolymer of step a); And Ii) the molecular weight is 80000-100000 and the acrylonitrile content is 24-30% by weight 50 to 80 parts by weight of styrene-acrylonitrile copolymer Kneading to prepare a thermoplastic resin Method for producing a thermoplastic resin comprising a. The method of claim 6, Wherein said thermoplastic resin composition has a weight average molecular weight of at least 75000 and a graft rate of at least 25%. The method of claim 6, The graft copolymerization of step a) is carried out at 60 to 80 ℃. (delete) The method of claim 6, The small-diameter rubber latex is polybutadiene or a copolymer of butadiene with an aromatic vinyl compound and a vinyl cyan compound. The method of claim 6, Said a) the aromatic vinyl compound of step ii) is selected from the group consisting of styrene, alphamethylstyrene, and vinyl toluene. The method of claim 6, The a) vinyl cyan compound of step ii) is acrylonitrile or methacrylonitrile. The method of claim 6, Wherein the initiator of step a) is cumene hydroperoxide, or diisopropyl benzene hydroperoxide. The method of claim 6, Said emulsifier in step iii) is selected from the group consisting of potassium rosin, sodium rosin, potassium oleate, sodium stearate, and alkyl arylsulfonates. The method of claim 6, Wherein said molecular weight modifier of step a) is selected from the group consisting of t-dodecyl mercaptan, n-dodecyl mercaptan, tabolinolten, dipentene, t-tyrpyene, and carbon tetrachloride. The method of claim 6, B) copolymerizing a styrene-acrylonitrile copolymer of step ii) at least two monomers selected from the group consisting of an aromatic mono alkenyl monomer, a vinyl cyan monomer, an acrylic acid alkyl ester monomer, and an alkyl ester monomer of methacrylic acid Prepared by.