KR20020054691A - Thermoplastic Resin Composition with Good Impact Strength, Gloss and Weather Durability and Method of Preparing the Same - Google Patents

Abstract

PURPOSE: Provided is a thermoplastic resin composition excellent in impact-resistance, gloss, and weather-resistance, which is produced by mixing an acryl-based graft copolymer latex and a graft ABS copolymer latex. CONSTITUTION: The thermoplastic resin composition is produced by mixing 70-100pts.wt. of the acryl-based graft copolymer latex and 30-0pts.wt. of the graft ABS copolymer latex with a graft rate of 40-60% and coagulating by using a coagulant and dehydrating and drying, wherein the graft ABS copolymer latex is produced by using a polybutadiene rubber with an average particle diameter of 0.3-0.45 micrometer. And the acryl-based graft copolymer latex is produced from a crosslinked acryl-based rubber latex with a polymerization rate of 95-99%, an average particle size of 0.15-25 micrometer, the gel content of 85-95wt%, and a solid component of 39-44%.

Description

Thermoplastic Resin Composition with Good Impact Strength, Gloss and Weather Durability and Method of Preparing the Same}

Field of invention

The present invention relates to a thermoplastic resin composition excellent in impact resistance, glossiness and weather resistance, and a method for producing the same. More specifically, the present invention provides an acrylic rubber latex having appropriately controlled particle size and distribution in manufacturing a thermoplastic resin having excellent weather resistance using an industrially advantageous emulsion polymerization, and then the rubber morphology of the graft copolymer and After preparing an acrylic graft copolymer latex having controlled balance such as graft ratio, and coagulating it by mixing with a graft ABS copolymer latex prepared using polybutadiene rubber, acrylonitrile-styrene or alphamethylstyrene The present invention relates to a thermoplastic resin composition having excellent weather resistance and high weather resistance after irradiation with ultraviolet rays, and a method of manufacturing the same, which have excellent impact strength and glossiness when mixed with acrylonitrile (SAN) resin.

Background of the Invention

ASA (acrylic rubber-styrene-acrylonitrile copolymer) resin is a thermoplastic resin composition that is widely used for exterior parts with high exposure to sunlight, such as electrical and electronic products, automotive parts, and agricultural equipment, which require weather resistance.

As the impact resistant thermoplastic resin, ABS (acrylonitrile-butadiene rubber-styrene copolymer) resin is widely used. However, ABS resin contains a large amount of chemically unstable double bonds in the rubber components used, so the rubber components are easily aged by UV rays, which is difficult to use for exterior applications such as automobile parts due to poor weather resistance. In the post-processing or the addition of a large amount of ultraviolet stabilizer during extrusion processing situation is used.

In order to solve the above problems, various methods are known. The main method is to replace the polybutadiene rubber used in the production of ABS resin, and the styrene using acrylic rubber containing no double bond is used as the main method. A method of copolymerizing acrylonitrile and a method of copolymerizing styrene and acrylonitrile on a rubber obtained by mixing a polybutadiene rubber latex and an acrylic rubber latex is known.

The former method is known from US Pat. Nos. 4,753,988 and 4,801,646, and Japanese Patent Application Laid-Open Nos. 60-3350 and 59-15331. The weather resistance is improved, but the particle size and distribution of the acrylic rubber are not appropriate. In the case of graft copolymerization, physical properties such as graft rate are not sufficient, so the impact strength is severely lowered, which is not practical.

The latter method is known from Japanese Patent Application Laid-Open Nos. 57-212215, 58-187411 and 57-167308. In this method, irregular rubbers are produced when preparing graft copolymers by mixing rubbers having different properties. Due to the graft polymerization reaction, it contains a large amount of non-grafted rubber components, which may improve weather resistance to some extent, but the impact strength and fluidity are remarkably reduced, thereby degrading the value as a resin.

The inventors of the present invention propose a new method to solve the above problems, and when grafting acrylonitrile and styrene monomers after appropriately adjusting the particle size and particle distribution of the rubber in preparing the acrylic rubber latex, the graft monomers are coated on the surface of the acrylic rubber. Is uniformly and sufficiently grafted to prepare a graft copolymer latex having excellent glossiness and good impact strength as well as excellent weather resistance of the acrylic rubber, and then recovering the graft copolymer latex as a powder. The present invention can produce a thermoplastic resin excellent in impact resistance, glossiness and weather resistance by mixing with an appropriate amount of the impact-resistant acrylonitrile-butadiene-styrene graft copolymer latex prepared in the solidification step during the treatment process and coagulation, dehydration and drying. To develop the method of the invention A.

An object of the present invention is to uniformly and sufficiently graf the graft monomer on the surface of acrylic rubber when grafting acrylonitrile and styrene monomer after appropriately adjusting the particle size and particle distribution of the rubber. It is to provide an acrylic graft copolymer latex having good gloss and an appropriate impact strength.

Another object of the present invention is to provide a thermoplastic resin composition excellent in impact resistance, glossiness and weather resistance by coagulation, dehydration and drying by mixing the graft copolymer latex with an appropriate amount of acrylonitrile-butadiene-styrene graft copolymer latex. It is for.

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

In order to manufacture the thermoplastic resin composition excellent in impact resistance, glossiness, and weather resistance of the present invention, first, an acrylic graft copolymer latex is prepared. The acrylic graft copolymer latex is prepared by a graft copolymerization step of graft polymerization of styrene and acrylonitrile monomers on the acrylic rubber latex prepared in the first step and the acrylic rubber latex prepared in the first step. do. And mixing the impact-resistant graft ABS copolymer latex with the acrylic graft copolymer latex prepared in the second step, coagulating using a coagulant, dehydrating, drying and recovering it as a powder, and SAN (styrene-acrylic). Ronitrile copolymer) mixed with resin to prepare a thermoplastic resin composition excellent in impact resistance, glossiness and weather resistance.

Acrylic graft copolymer latex in the present invention is prepared by a two-step process. The first step is a polyfunctional monomer (crosslinking agent), an anionic emulsifier, a polymerization initiator, an ion having one or more monomers, an acrylic monomer having two or more functional groups copolymerizable with the monomer, from an acrylic acid ester having 1 to 13 carbon atoms. It is a process for producing crosslinked acrylic rubber latex having an average particle diameter in the range of 0.10 to 0.25 μm and appropriately crosslinked by the method of distributing and adding exchanged water. The second step is one or more monomer mixtures in an aromatic vinyl monomer, one or more monomer mixtures in an unsaturated nitrile monomer, anionic in the presence of 40 to 60 parts by weight (based on solids) of the crosslinked acrylic rubber latex. It is a process of grafting by the method of adding an emulsifier, a polymerization initiator molecular weight modifier, and ion-exchange water. The acrylic graft copolymer latex with improved gloss and weather resistance as well as impact resistance is prepared by the two step method.

A thermoplastic resin composition having excellent impact resistance, glossiness, and weather resistance is prepared by mixing graft ABS latex having an average particle diameter of 0.3 to 0.45 µm and a graft ratio of 40 to 60% to the acrylic graft copolymer latex prepared above.

The production method of the thermoplastic resin composition excellent in impact resistance, glossiness and weather resistance according to the present invention will be described in detail below.

(1) Acrylic Rubber Latex Manufacturing

Acrylic rubber latex is produced by a two-step process.

First, in the first step, 5 to 35 parts by weight of butyl acrylate, 0.03 to 1.5 parts by weight of triaryl isocyanurate, 0.5 to 2.5 parts by weight of potassium rosin salt, 0.2 to 1.5 parts by weight of anionic emulsifier, and 0.05 to potassium carbonate 0.7 parts by weight and ion-exchanged water were added to the inside of the reactor, stirred, and heated to an appropriate temperature. Then, 0.05 to 0.45 parts by weight of potassium persulfate was added to react to make a particle size of 0.05 to 0.15 µm.

Next, in the second step process, 95-65 parts by weight of butyl acrylate, 0.5-2.8 parts by weight of triaryl isocyanurate, 0.5-2.5 parts by weight of potassium rosin salt, and ion-exchanged water are stirred in the first reacted rubber latex. Put them in a container as possible and prepare them in a pre-emulsion state, and continuously add them for 2 to 4 hours to grow the particle size to 0.15 to 25 μm, and then continuously add 1.0 to 3.0 parts by weight of potassium rosinate for 30 to 90 minutes, and then To increase the stability, block the coagulation of rubber particles, and then terminate the polymerization. The crosslinking rate is 95 to 99%, the average particle size is 0.15 to 25 ㎛, the gel content is 85 to 95% by weight, and the solid content is 39 to 44%. Prepared acrylic rubber latex.

(2) Acrylic Graft Copolymer Preparation

The acrylic graft copolymer is prepared by a two step process from the crosslinked acrylic rubber latex.

First, in the first step, in the presence of 40 to 60 parts by weight of the crosslinked acrylic rubber latex (solid content) selected from aromatic vinyl monomers such as styrene, alpha-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene and vinyltoluene. 0 to 40% by weight in 60-40 parts by weight of one or more monomer mixtures selected from one or more monomers and unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile; 0.1 to 2.5 parts by weight of anionic emulsifiers such as alkali metal salts of alkyl sulfates of 8 to 18 carbon atoms such as sodium lauryl sulfate, alkali metal salts of fatty acids or rosin acids; Molecular weight regulators of mercaptans; And after putting ion-exchanged water into a reactor and stirring and raising temperature, when the mixture temperature reaches 55-65 degreeC, it stirs within 30 minutes, and puts a polymerization initiator, such as potassium persulfate and a sodium pessulfate, and initiates reaction, and it is a primary graph. Manufactures latex.

Then, in the second step, the remaining graft monomer mixture and the molecular weight modifier are mixed in the presence of the prepared first graft latex, and then the graft monomer added by the method is added continuously for 2 to 5 hours. Induced to be grafted mostly to rubber particles to prepare an acrylic graft copolymer latex.

70-100 parts by weight of the acrylic graft copolymer latex prepared above was mixed with 30-0 parts by weight of a graft ABS copolymer latex having a graft ratio of 40-60% using a polybutadiene rubber having an average particle diameter of 0.3-0.45 μm. The coagulant is solidified and then dehydrated and dried to obtain a graft copolymer latex having excellent impact resistance, gloss and weather resistance.

(3) Preparation of the thermoplastic resin composition

The above-mentioned acrylic graft copolymer latex was coagulated and dried to obtain a powder, and styrene-acrylonitrile copolymer (SAN-1) and alphamethylstyrene-acrylonitrile copolymer (SAN-2) were added thereto. To obtain a thermoplastic resin composition having excellent impact resistance, glossiness, and weather resistance through extrusion and injection processes.

As an example, 40 parts by weight of the graft copolymer prepared above, 20 parts by weight of SAN-1 and 40 parts by weight of SAN-2 were mixed. 0.3 parts by weight of magnesium stearate as a stabilizer and 1.0 parts by weight of ethylene bis stearoid were added to each other, followed by extrusion and injection molding to prepare specimens for measuring physical properties.

The following examples are presented to illustrate the advantages of the present invention and are not intended to limit the protection scope of the present invention. In the following examples and this patent application, "parts" are all based on weight unless otherwise stated, and are values when the amount of monomers is 100.

Example

Preparation of crosslinked acrylic rubber latex:

20 parts by weight of butyl acrylate, 0.2 parts by weight of triaryl isocyanurate, 1.0 part by weight of potassium rosinate, 0.5 part by weight of anionic emulsifier, 0.5 part by weight of potassium bicarbonate, and 130 parts by weight of ion-exchanged water were added to the reactor and stirred. Then, the reactor was heated to 65 ° C., and then stirred for an additional 10 minutes when the reactor temperature was 65 ° C., followed by adding 0.30 parts by weight of potassium persulfate to initiate the reaction, thereby increasing the reactor temperature to 75 ° C. over 1 hour. Cooling and heating induce temperature and time.

When the temperature of the mixture reaches 75 ° C, the reaction is continued for an additional 10 minutes so that most of the first charged monomer is polymerized to have a polymerization rate of 93% or more, followed by 80 parts by weight of the remaining amount of butyl acrylate and trill in a separate stirred container. 0.6 parts by weight of aryl isocyanurate, 1.5 parts by weight of potassium rosinate, and 10 parts by weight of ion-exchanged water were mixed and stirred into a pre-emulsion state, and the pre-emulsion mixture was continuously added for about 2 hours. do.

After completion of the secondary graft monomer mixture, additional 2.0 parts by weight of potassium rosin salt was continuously added over 1 hour to give sufficient stability of the acrylic rubber latex, and after forced cooling at a polymerization rate of 97% or more, the solid part was 40% or more, A crosslinked acrylic rubber latex having an average rubber particle size of 0.17 µm and a gel content of 88% was prepared.

Examples 1 to 3

50 parts by weight of the crosslinked acrylic rubber latex obtained above (based on solids), 0.5 part of potassium rosinate, and 150 parts of ion-exchanged water were added thereto, and the reactor temperature was raised to 60 ° C. while stirring. 0.25 part potassium potassium is added and stirred for 10 minutes. Then, 15 parts of acrylonitrile, 35 parts of styrene, and 0.03 parts of tertiary dodecyl mercaptan were added to a stirred container, stirred, and continuously added for 5 hours. The graft monomer was continuously added, and the reactor temperature was 75 ° C at the end. After the completion of the graft monomer addition, the reaction was continued at 75 ° C. for 20 minutes, followed by forced cooling to terminate the reaction.

The graft rate is 55%, the solid content is 39.5%, and the amount of coagulum generated is 0.05%. Magnesium sulfate by mixing the graft copolymer latex obtained in the above example using a polybutadiene rubber having an average particle diameter of 0.3-0.45 μm and graft ABS copolymer latex having a graft ratio of 40-60% by ratio as shown in Table 1 The coagulant mixed with 1% and 0.2% sulfuric acid was solidified and then dehydrated and dried to obtain a graft copolymer having excellent impact resistance, gloss and weather resistance. Physical properties of the graft copolymers of Examples 1-3 are shown in Table 2.

Examples 4-5

Except for using 60 parts by weight of the cross-linked acrylic rubber latex obtained in the same manner as in Example 1, the graft rate is 50%, the solid content is 39.6%, the amount of coagulation is 0.03%. Physical properties of the graft copolymers of Example 4-5 are shown in Table 2.

Comparative Example 1

A graft copolymer latex was prepared in the same manner as in Example 1 except that 40 parts by weight of the acrylic rubber latex obtained above and 10 parts by weight of the polybutadiene rubber latex having an average particle diameter of 0.38 μm were used. The graft copolymer powder is prepared by coagulation, dehydration and drying. The graft rate is 35%, the solid content is 39.5%, and the amount of coagulation is 0.15%. Physical properties of the graft copolymer of Comparative Example 1 are shown in Table 2.

Comparative Example 2

It is the same as Comparative Example 2, except that 30 parts by weight of the acrylic rubber latex obtained above and 20 parts by weight of polybutadiene rubber latex having an average particle diameter of 0.38 μm are mixed. The graft ratio is 55%, the solid content is 39.3%, and the coagulum is used. The amount of generation is 0.25%. Physical properties of the graft copolymer of Comparative Example 2 are shown in Table 2.

ingredient Example One 2 3 4 5 Graft Copolymer Mixing Ratio Acrylic graft copolymer (% by weight) 100 90 80 90 80 Graft ABS Copolymer Latex (wt%) - 10 20 10 20

Characteristics of the resin Properties after 1000hr irradiation IZOD impact strength liquidity Heat deflection temperature Glossiness IZOD impact strength Example 1 38 7.6 101 98 32 Example 2 48 7.9 101 97 43 Example 3 50 7.6 101 96 41 Example 4 52 7.5 100 97 48 Example 5 55 7.2 100 96 50 Comparative Example 1 35 6.8 101 85 23 Comparative Example 2 39 7.1 101 81 20

Property evaluation method

In order to evaluate the stability of the graft copolymer latex prepared according to Examples 1 to 5 and Comparative Examples 1 and 2, the coagulum which failed to pass by filtering the graft copolymer latex through a mesh of about 200 mesh. Was dried by dehydration with water, and then the amount of coagulum was calculated by the following Equation 1:

According to Examples 1 to 5 and Comparative Examples 1 to 2, the graft copolymer latex was coagulated with isopropyl alcohol, dehydrated and dried to obtain a white powder, dissolved in acetone, centrifuged, and the insoluble was washed and dried. Basis weight was used to calculate the graft rate by the following formula 2:

Specimens of the resin composition prepared according to Examples 1 to 5 and Comparative Examples 1 to 2 were notched in accordance with ASTM D-256 (1/8 "notch, unit kg · cm / cm, 23 ° C). The flow index (g / 10min) was measured at 220 ° C. and 10 kg according to ASTM D-1238, the heat deflection temperature was measured according to ASTM D-1525, and the glossiness was measured according to ASTM D523.

According to the present invention, the graft monomer is uniformly and sufficiently grafted on the surface of the acrylic rubber when grafting acrylonitrile and styrene monomer after appropriately adjusting the particle size and particle distribution of the rubber. The acrylic graft copolymer latex having an appropriate impact strength and an appropriate impact strength is provided, and the graft copolymer latex is mixed with an acrylonitrile-butadiene-styrene graft copolymer latex in an appropriate amount to coagulate, dehydrate, and dry to give impact resistance and glossiness. And the invention of providing a thermoplastic resin composition excellent in weatherability.

All modifications and variations of the present invention fall within the scope of the present invention and the protection scope of the present invention will be defined by the appended claims.

Claims (5)

5 to 35 parts by weight of butyl acrylate, 0.03 to 1.5 parts by weight of triaryl isocyanurate, 0.5 to 2.5 parts by weight of potassium rosin salt, 0.2 to 1.5 parts by weight of anionic emulsifier, 0.05 to 0.7 parts by weight of potassium carbonate and ions The exchanged water was put in a reactor, stirred to raise the temperature to an appropriate temperature, and then reacted by adding 0.05 to 0.45 parts by weight of potassium persulfate to make the particle size 0.05 to 0.15 µm; 95-65 parts by weight of butyl acrylate, 0.5-2.8 parts by weight of triaryl isocyanurate, 0.5-2.5 parts by weight of potassium rosin salt and ion-exchanged water were added to the firstly reacted rubber latex in a stirred container. After making into an emulsion state, it is continuously added over 2 to 4 hours to grow the particle size to 0.15 to 25 μm; And Continuously adding 1.0 to 3.0 parts by weight of potassium rosin acid to the secondary reactant for 30 to 90 minutes to increase stability in the polymerization system to block aggregation of rubber particles and to terminate polymerization; A method for producing a crosslinked acrylic rubber latex having a polymerization rate of 95 to 99%, an average particle size of 0.15 to 25 µm, a gel content of 85 to 95% by weight, and a solid content of 39 to 44%. (A) (i) 5 to 35 parts by weight of butyl acrylate, 0.03 to 1.5 parts by weight of triaryl isocyanurate, 0.5 to 2.5 parts by weight of potassium rosin salt, 0.2 to 1.5 parts by weight of anionic emulsifier, potassium carbonate 0.05 ˜0.7 parts by weight and ion-exchanged water were added to the inside of the reactor, stirred to raise the temperature to an appropriate temperature, and then reacted by addition of 0.05 to 0.45 parts by weight of potassium persulfate to a particle size of 0.05 to 0.15 μm; (ii) 95 to 65 parts by weight of butyl acrylate, 0.5 to 2.8 parts by weight of triaryl isocyanurate, 0.5 to 2.5 parts by weight of potassium rosin salt and ion-exchanged water in a vessel capable of stirring Put all of them into a pre-emulsion state, and continuously added over 2 to 4 hours to grow the particle size to 0.15 to 25 μm; And (iii) continuously adding 1.0 to 3.0 parts by weight of potassium rosin acid to the secondary reactant for 30 to 90 minutes to increase the stability in the polymerization system to block the aggregation of rubber particles, and then to terminate the polymerization of the acrylic rubber crosslinked. Preparing latex; And (B) (i) selected from aromatic vinyl monomers such as styrene, alpha-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene and vinyltoluene in the presence of 40 to 60 parts by weight of the crosslinked acrylic rubber latex (solid content); 0 to 40% by weight in 60-40 parts by weight of one or more monomer mixtures and one or more monomer mixtures selected from unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile; 0.1 to 2.5 parts by weight of anionic emulsifiers such as alkali metal salts of alkyl sulfates of 8 to 18 carbon atoms such as sodium lauryl sulfate, alkali metal salts of fatty acids or rosin acids; Molecular weight regulators of mercaptans; And after putting ion-exchanged water into the reactor and stirring and raising the temperature, the mixture was stirred within 30 minutes when the temperature of the mixture reached 55-65 ° C., and a polymerization initiator such as potassium persulfate or sodium pesulfate was added to initiate the reaction. Graft latex was prepared by (ii) mixing the remaining graft monomer mixture and molecular weight modifier in the presence of the primary graft latex prepared above, followed by continuous dosing over 2 to 5 hours. Most of the monomers are grafted to the rubber particles; Method for producing an acrylic graft copolymer latex, characterized in that consisting of steps. Acrylic graft copolymer latex prepared according to the method of claim 2. 70 to 100 parts by weight of the acrylic graft copolymer latex according to claim 3 is mixed with 30 to 0 parts by weight of a graft ABS copolymer latex having a graft ratio of 40 to 60% using a polybutadiene rubber having an average particle diameter of 0.3-0.45 μm. A graft copolymer latex having excellent impact resistance, glossiness, and weather resistance prepared by coagulation using a flocculant, followed by dehydration and drying. Impact resistance, glossiness and weather resistance prepared by adding the styrene-acrylonitrile copolymer and the alphamethylstyrene-acrylonitrile copolymer to the acryl-based graft copolymer latex according to claim 3 through coagulation and drying. This excellent thermoplastic resin composition.