KR100513658B1 - Perparation of thermoplastic resin composition having excellent thermal stability and power properties - Google Patents

Abstract

The present invention includes acrylonitrile-butadiene-, comprising a styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with a butadiene-based rubber polymer, a styrene-acrylonitrile (SAN) resin and a reactive emulsifier. Provided are a styrene (ABS) thermoplastic resin composition and a method of manufacturing the same.

The present invention can secure the emulsification stability of the styrene-acrylonitrile (emulsified SAN) resin even with a small amount of emulsifier, improve the particle size and aggregation characteristics, and improve physical properties such as thermal stability and processing characteristics when processing ABS resin. .

Description

Thermoplastic resin composition having excellent thermal stability and powder characteristics, and a method of manufacturing the same {Perparation of thermoplastic resin composition having excellent thermal stability and power properties}

The present invention relates to an acrylonitrile-butadiene-styrene thermoplastic resin (Acrylo nitrile-Butadiene-Styrene: ABS) composition having excellent thermal stability and powder characteristics, and a manufacturing method thereof. More specifically, acrylonitrile-butadiene-styrene system comprising a styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with a butadiene-based rubber polymer, a styrene-acrylonitrile (solution SAN) resin and a reactive emulsifier A thermoplastic resin composition and a method for producing the same.

In general, ABS resins are excellent in mechanical properties, excellent in colorability and formability, and are widely used in housings, automobiles, and toys for electric and electronic products. ABS resin is made into pellets by extrusion and kneading of ABS powder made by emulsion polymerization and styrene-acrylonitrile copolymer having a molecular weight of 80,000 to 200,000 made by solution polymerization (hereinafter referred to as 'solution SAN'). It is injected again and processed into the desired shape.

When used in simple small household appliances or toys, it is possible to manufacture the product through the extrusion process without any change in the components as described above. However, large home appliances such as refrigerators are manufactured by blow molding using sheet extrusion rather than pellets, which are 80,000 to 200,000 manufactured using conventional solution polymerization. When a styrene-acrylonitrile copolymer (solution SAN) having a weight average molecular weight of is used for the ABS resin, the fluidity of the ABS resin is drastically decreased, resulting in a decrease in productivity, and in a thin part due to the thickness irregularity of the molded article. The cracking made it difficult to process large molded parts, especially thin thicknesses.

As part of the method for solving this difficulty, an ultra-high molecular weight styrene-acrylonitrile copolymer having a molecular weight of 1,000,000 to 4,000,000 emulsified using an adsorptive emulsifier in a styrene-acrylonitrile copolymer (solution SAN) prepared by solution polymerization. By adding a small amount of the thermoplastic resin, a thermoplastic resin capable of maintaining the mechanical strength of the molded article at the time of high temperature processing and of obtaining a thin molded article having a small variation in thickness has been proposed.

However, in the case of the ultra-high molecular weight styrene-acrylonitrile copolymer prepared by the emulsion polymerization method, in order to obtain ultra-high molecular weight, an excessive amount of emulsifier is used, unlike general emulsion polymerization, and an emulsifier used in excess during emulsion polymerization There was a problem that can excessively generate foam during polymerization. In addition, in the transfer of latex after polymerization and excessive foam is generated in the coagulation and dehydration process using the same, the manufacturing process is delayed, and the desired copolymer resin is simultaneously lost during the removal of the foam, which may cause a decrease in process yield. There is a problem.

In addition, in the case of the ultra-high molecular weight styrene acrylonitrile copolymer prepared by emulsion polymerization, the glass transition temperature is in the range of 110 to 120, so that powder of too fine particle size is obtained under the normal atmospheric pressure condition. Of course, it may cause problems such as inhibition of the working environment due to the scattering of fine powder.

In order to solve this problem, an excessive amount of metal salt coagulant may be used or pressure agglomeration may be performed. However, such an excessive amount of coagulant may impair the thermal stability of the resin under high temperature processing conditions. There is a possibility of causing difficulties in the condition. In addition, in the case of an ABS product manufactured using an ultra high molecular weight styrene-acrylonitrile copolymer prepared using such an excessive amount of an emulsifier and a flocculant as an additive, the carbonization of the residual emulsifier due to the high temperature during processing under high temperature molding conditions Of course, due to the gas generated there is a problem that can reduce the gloss of the molded article or leave traces of carbide on the appearance of the molded article.

In Japanese Patent Application Laid-Open No. 2002-069892, "Reactive Emulsifier for Paper Coating, Copolymer Latex for Paper Coating, and Paper Coating Composition", the flowability under high shear force is applied by applying a reactive emulsifier in the production of a paper coating material. In addition to improving the physical properties of the coated paper such as peak strength, which also mentions the use only in the latex state, there is no mention of the effect of the emulsifier on the product made in powder form.

As described in the above patents, general reactive emulsifiers are used to effectively secure latex stability and to prevent the transparency of the coating surface due to the waterproofness of the coating or the dissolution of the emulsifier when the latex itself is used, such as a coating material. There was no case of improving the thermal stability by making powder.

In the present invention, by using a reactive emulsifier different from the adsorption type emulsifiers generally used as a method for solving the above problems, the emulsion stability is ensured even under a small amount of the emulsifier, and the coagulation characteristics are improved as well as the processing conditions at high temperatures. It is an object of the present invention to provide an ABS-based resin composition and a method of manufacturing the same, which can reduce the amount of gas generated by thermal decomposition of an emulsifier under the present invention and improve the appearance characteristics of a molded article during processing.

In the acrylonitrile-butadiene-styrene thermoplastic resin composition,

a) butadiene rubber polymer;

b) styrene-acrylonitrile (SAN) resins; And

c) Styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with a reactive emulsifier

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

In addition, the present invention comprises the step of introducing a styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with butadiene-based rubber polymer, styrene-acrylonitrile (solution SAN) resin and a reactive emulsifier It provides a method for producing an acrylonitrile-butadiene-styrene thermoplastic resin composition.

Hereinafter, the present invention will be described in detail.

The a) butadiene-based rubber polymer is a butadiene-based rubber polymer grafted by emulsion polymerization or bulk polymerization method using styrene and acrylonitrile in the presence of polybutadiene, preferably 20 to 50% by weight.

The styrene-acrylonitrile resin (solution SAN) is a conventional one obtained by reacting a vinyl cyanide compound with an aromatic vinyl compound. The content of the vinyl cyan compound is 20 to 40% by weight, and the weight average molecular weight is 80,000 to It is preferable that it is a styrene-acrylonitrile (SAN) resin which is 200,000. In the ABS resin composition of the present invention, the preferable content of the solution SAN is 50 to 80% by weight.

The styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with the reactive emulsifier is prepared by emulsion polymerization of a vinyl cyanide compound and an aromatic vinyl compound with a reactive emulsifier. The content of the vinyl cyan compound is 20-50 wt%. %, The weight average molecular weight is 1,000,000 ~ 4,000,000, the preferred content is 0.5 to 15 parts by weight based on 100 parts by weight of the butadiene-based rubber polymer and styrene-acrylonitrile (SAN) resin as main components.

The styrene-acrylonitrile resin (emulsified SAN) prepared by emulsion polymerization with the reactive emulsifier is a resin component containing 50 to 80% by weight of an aromatic vinyl compound and 20 to 50% by weight of a vinyl cyanide compound, and the resin component 100 It is prepared using a polymerization composition comprising 0.1 to 3.0 parts by weight of the reactive emulsifier and 0.05 to 1.0 parts by weight of the polymerization initiator.

More specifically, from 50 to 80% by weight of the aromatic vinyl compound and 20 to 50% by weight of the mixture of vinyl cyanide compound, 0 to 20 parts by weight may be divided once or several times, respectively, in batch administration or continuous administration. In this case, 0.1 to 3.0 parts by weight of an emulsifier and 0.05 to 1.0 parts by weight of a polymerization initiator may be used to induce stability and start reaction of the emulsion polymerization.

In preparing the ABS resin composition of the present invention, the emulsified SAN is reacted by initially administering 0-50% of the total monomers of the emulsified SAN, and the remaining monomers may be administered through a batch or continuous administration method.

In this case, as the method of administering the monomer, a method of collectively administering the monomer alone and an emulsifier and a method of administering the batch or continuous in an emulsified state with a certain amount of water may be applied. When the initial monomer is added, the reaction starting temperature is appropriately around 40 to 50 degrees, and the temperature inside the reactor is appropriately maintained so as not to exceed 70 degrees when the temperature is raised due to the monomer polymerization heat.

If the reaction temperature is too low during the polymerization reaction, it is difficult to proceed the efficient reaction due to the delay of the polymerization initiation reaction, which may cause problems in the process and the yield. When the polymerization proceeds under the high temperature reaction condition of 70 or more, it is excessive. Difficulty in temperature control due to the exotherm, of course, may cause a decrease in the molecular weight of the polymer to exhibit a tendency to meet the intended use of the high molecular weight styrene-acrylonitrile copolymer is not preferable.

The emulsified SAN can be produced in a stable emulsified SAN with a small amount of emulsifier by using a reactive emulsifier, and at the same time, acid aggregation can be performed by selecting an emulsifier capable of appropriate acid aggregation. In this case, the pyrolysis of the emulsifier under high temperature thermal processing conditions will not only have a lower emulsifier content more effectively than a general manufacturing method, but also the emulsifier will form a polymer or oligomer by forming a copolymer with a monomer and the like, rather than a low molecular material. Due to lowering of thermal stability, more stable conditions can be ensured.

In addition, in the case of the emulsified SAN may be added during the production of the ABS resin may exhibit an improvement in elongation at high temperature, the reactive emulsifier may vary depending on the type of the emulsifier and the monomer to react, but in the presence of a radical initiator These two materials will copolymerize with each other.

The emulsifier used in the preparation of the emulsified SAN of the present invention is a reactive emulsifier, which combines the properties of the existing emulsifier and the properties of the monomers. Unlike the emulsifiers of the adsorption and desorption type, latex is stabilized by chemical bonding and has the following advantages.

1) There is no surface elution of the emulsifier on the final product.

2) Low emulsifier ensures effective latex stability.

3) Less foam and less wastewater.

4) Less likely to generate gas due to residual emulsifier.

Examples of the reactive emulsifier used in the emulsion polymerization reaction include an anionic emulsifier and a neutral emulsifier having an allyl group, a (meth) acryloyl group, or a propenyl group. Anionic emulsifiers having an allyl group include sulfate salts of polyoxyethylene allylglycidyl nonylphenyl ether, and the Adecaria SOAP SE series (manufactured by Asahi Denka) is useful in the market. have. Other anionic reactive emulsifiers having alkenyl groups include alkenyl succinate letter esque (LATEMUL ASK, manufactured by Kao). Similarly, allyl-based neutral emulsifiers include polyoxyethylene allylglycidyl nonylphenyl ether series, and commercially available products include the Adecaria SOAP NE family (manufactured by Asahi Denka). Commercially available anionic emulsifiers having a (meth) acryloyl group include the ELEMINOL RS series (manufactured by Sanyo Kasei) and the neutral emulsifier RMA-560 series (manufactured by Nippon Surfactant). There is this. Anionic emulsifiers having a propene group include ammonium sulfate salts of polyoxyethylene allylglycidyl nonyl propenyl phenyl ether. Commercially available ones include AQUARON HS series and neutral emulsifiers. Among them are the AQUARON BC family (product of Daiichi Kogyo Seiyaku).

The reactive emulsifier may be used alone or as a mixture of two or more thereof. Alternatively, the reactive emulsifier may be used in combination with a common adsorptive emulsifier such as sotyet lauryl sulfate, oleic acid salt, fatty acid salt, rosin acid salt and the like. At this time, the amount of the reactive emulsifier used during the reaction is preferably 0.1 to 3.0 parts by weight relative to 100 parts by weight of the total amount of the emulsified SAN monomer in terms of ensuring stability.

As the polymerization initiator, peroxide initiators such as tertiary butyl hydroperoxide, hydroperoxide, cumene hydroperoxide, diisopropyl benzenehydro peroxide, persulfate, and the like may be generally used. It is preferable to use 0.05-1.0 weight part with respect to 100 weight part of total monomers of an aromatic vinyl compound copolymer.

At the same time, an oxidation-reduction catalyst may be used simultaneously to facilitate the initiation reaction of the initiator. Examples thereof include metal salts such as iron (II), iron (III), cobalt (II), cerium (IV), and reducing agents. Polysaccharides such as dextrose, glucose, and plotose, dihydroxy acetone or poly amines can be used, and additionally tartaric acid, citric acid, phyllphosphoric acid, to maintain the activity of the metal catalyst under various basic conditions Ethylene diamine tetraacetic acid salt and the like can be used.

The polymerized latex can be used in the form of powder through agglomeration in the high temperature range of 90 ~ 95 using sulfuric acid or magnesium sulfate, calcium chloride, aluminum sulfate, etc. which are well known flocculants. In order to improve the particle size characteristics and thermal stability, it is generally preferable to use an acid coagulant rather than a metal coagulant, and it is appropriate to use about 1-3 parts by weight based on the total solid content (monomer 100).

The ultra high molecular weight styrene-acrylonitrile (emulsified SAN) powder having a weight average molecular weight of 1,000,000 to 4,000,000 obtained by emulsion polymerization has a molecular weight of 80,000 to 200,000 and a content of 20 to 40% by weight of vinyl cyanide. 50 to 80 parts by weight of acrylonitrile resin (solution SAN) and 0.5 to 15 parts by weight of 20 to 50 parts by weight of acrylonitrile-styrene-butadiene resin prepared by emulsion polymerization to solution polymerization are subjected to extrusion and injection process. Prepare the specimen.

[How to measure]

The measurement method of physical properties of the powder specimen prepared by the coagulation and dehydration process of the ABS resin polymerized by the method of Examples and Comparative Examples are as follows.

(1) particle size

100 g of powder prepared by coagulation, dehydration and drying conditions are placed in a mesh tower with different pore sizes (mesh #: 60-80-100-120-140-160-200), sieved for 10 minutes, and then applied to each mesh. The powder characteristics were measured by measuring the amount of powder remaining. The more powder remaining in the mesh number 100, the smaller the amount of powder passing through the mesh number 200 was determined to be excellent in powder characteristics.

(2) gloss of stay

When extruded using pellets obtained through extrusion, the glossiness was measured at an angle of 45 degrees using a gloss meter for the injection specimen under the normal injection conditions of 230 and left in the injection machine for 15 minutes at 270 degrees. Changes are expressed as percentages. In general, the smaller the value, the better the thermal stability at the time of stay.

(3) Density (B / D: Bulk Density)

A certain amount of powder is randomly sampled and filled in a hopper, and then freely dropped in a 100 ml container, and the powder weight (g) is measured to measure particle size characteristics of the powder. In general, the higher the value, the better the grain size.

Example 1

1. Preparation of vinyl cyanide compound and aromatic vinyl compound copolymer resin (emulsification SAN)

100 parts by weight of water and 0.6 parts by weight of a reactive emulsifier (latemul ASK) were added to a four-necked flask, followed by stirring under a nitrogen atmosphere at room temperature for 30 minutes.

Next, 18.5 parts by weight of styrene and 6.5 parts by weight of acrylonitrile were mixed, the temperature was raised to 50 degrees over 1 hour, and then 0.03 parts of potassium persulfate, which is a water-soluble initiator, was used as an initiator, and the temperature was raised to 60 degrees for 1 hour. At this time, the calorific value due to polymerization is not more than 70 degrees.

Next, an emulsion consisting of 22.2 parts by weight of styrene, 7.8 parts by weight of acrylonitrile, 0.2 parts by weight of reactive emulsifier (Latemul ASK), 0.02 parts by weight of potassium persulfate, and 40 parts by weight of water was added slowly over 30 minutes, followed by 1 hour 30 minutes. Continue the reaction. At this time, the temperature inside the reactor is maintained not to exceed 70 degrees.

Thereafter, an emulsion composed of 33.3 parts by weight of styrene, 11.7 parts by weight of acrylonitrile, 0.2 parts by weight of Lettermul ASK, 0.01 parts by weight of potassium persulfate, and 50 parts by weight of water was added over 3 hours. At this time, the temperature of the reactor due to the heat generated by the polymerization is maintained not to exceed 70 degrees.

The latex thus obtained was agglomerated using sulfuric acid as a flocculant and then dehydrated and dried to prepare a vinyl cyanide compound and an aromatic vinyl compound copolymer resin powder having a weight average molecular weight of 3,000,000.

2. Manufacture of budadiene rubber polymer

40 parts by weight of styrene monomer and acrylonitrile in a weight ratio of 40:60 to 60 parts by weight of a polybutadiene emulsion polymer having an average rubber particle diameter of 3000Å and a gel content of 80%, Graft copolymerization by adding graft copolymerization, in which 20% of the total monomers are administered in a batch and 80% by weight of the monomers are continuously administered in an emulsified state together with an emulsifier and an initiator. It is coagulated and dried through acid coagulation to prepare a powder.

3. Solution SAN Manufacturing Process

Solution SAN is prepared by using 55 or more parts of styrene monomer, 25 parts by weight of acrylonitrile and 20 parts by weight of the recovery mixture into the reactor, and then using one or more reactors at a reaction temperature of 150 ° C. In this case, the reactor used may be a boiling type or a full liquid type, and the polymer and the unreacted monomer, and the solvent and the unreacted monomer, which have undergone the reaction process, are removed in the volatilization process. The weight average molecular weight of the polymer passed through this process is about 200,000, and has a residual content of 1000 ppm.

4. Kneading process

Butadiene-based rubber polymer prepared by the above method (Third copolymer made of Acrylonitrile-Butadiene-Styrene) 70 parts by weight of a copolymer of a vinyl cyanide compound and an aromatic vinyl compound (solution SAN, weight average molecular weight 200,000) containing 28% by weight of a vinyl cyanide compound And 1.5 parts by weight of a vinyl cyanide compound and an aromatic vinyl compound prepared by emulsion polymerization are mixed. Then, a small amount of lubricant, heat stabilizer, etc., added to general ABS production for extrusion is added and extruded to make pellets. And it is injected to produce a specimen.

Example 2

As in Example 1, except that a mixture of a reactive emulsifier (Latemul ASK) and an oleic acid salt (usage is shown in Table 1) was used as the emulsifier used in Example 1, and the amount and physical properties of the emulsifier used were Table 1 and 2.

Comparative Example 1

The same as in Example 1 except for using Sodyan Raoul sulphate salt (use amount is shown in Table 1) as the emulsifier used in Example 1, and the amount and physical properties of the emulsifier are shown in Table 1 and 2, respectively.

Comparative Example 2

Except for the use of oleic acid salt and sodyan lauryl sulfate salt as the emulsifier used in Example 1 (usage is shown in Table 1) and the same as in Example 1 and the amount and physical properties of the emulsifier in Table 1 and 2, respectively Shown in detail.

[Table 1] Type and amount of emulsifier used

[Table 2] Comparison of particle size, density and retention gloss

In general, when the thermal stability is small, especially when an emulsifier (general adsorption-type emulsifier) is used, the gloss decreases due to gas on the surface of the injection molding due to thermal decomposition under high temperature processing conditions. Therefore, if the decrease in glossiness during staying is low, it is considered that the gas generation amount, that is, the thermal stability is good.

In addition, the more the fine powder content in the general processing conditions in the density (bulk density) and the particle size, especially in the case of the 200 mesh pass shown above is a very fine powder, it is difficult to work due to the scattering of fine dust when used in the processing conditions May cause Therefore, the lower the 200mesh pass (content of the powder passed through the mesh) and the more 100mesh on (content of the powder placed on the mesh), the better the workability.

However, too many coarse particles are not necessarily good. Bulk density refers to the degree of filling of the powder, since this increases the volume and increases the transportation costs in production. Therefore, as shown in Table 2, the bulk density is good and at the same time has a small powder content of fine particles.

The acrylonitrile-butadiene-styrene thermoplastic resin of the present invention is prepared using a styrene-acrylonitrile (emulsified SAN) resin prepared using a reactive emulsifier rather than a conventional adsorptive emulsifier. In addition, it is possible to secure emulsion stability, thereby improving particle size and agglomeration characteristics, as well as reducing an amount of gas generated by pyrolysis of an emulsifier under high temperature processing conditions, thereby improving appearance characteristics of a molded article during processing.

Claims (9)

In the acrylonitrile-butadiene-styrene thermoplastic resin composition, A) butadiene-based rubber polymer and b) styrene-acrylonitrile (SAN) resin as main components; And C) a styrene-acrylonitrile (emulsified SAN) resin having a weight average molecular weight of 1,000,000 to 4,000,000 prepared by emulsion polymerization with a reactive emulsifier; The content of the a) butadiene-based rubber polymer in the total weight of the main component is 20 to 50% by weight, b) the content of the styrene-acrylonitrile (SAN) resin is 50 to 80% by weight, Styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with c) a reactive emulsifier as a minor component based on 100 parts by weight of the main ingredient is acrylonitrile-butadiene- Styrene-based thermoplastic resin composition. The method of claim 1, The acrylonitrile-butadiene-styrene thermoplastic resin composition, wherein the reactive emulsifier has an aryl group, acryloyl group, or propenyl group. delete The acrylonitrile-butadiene-styrene system according to claim 1, wherein the b) styrene-acrylonitrile (SAN) resin has a content of vinyl cyan compound of 20 to 40 wt% and a weight average molecular weight of 80,000 to 200,000. Thermoplastic resin composition. The styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with c) a reactive emulsifier has an acrylonitrile content of 20 to 50% by weight. Butadiene-styrene thermoplastic resin composition. The method of claim 1, Styrene-acrylonitrile (emulsion SAN) resin prepared by emulsion polymerization with a reactive emulsifier as the c) component comprises a resin component containing 50 to 80% by weight of an aromatic vinyl compound and 20 to 50% by weight of a vinyl cyanide compound; Acrylonitrile-butadiene-styrene-based thermoplastic resin composition characterized in that it is prepared by polymerizing 0.1 to 3.0 parts by weight of the reactive emulsifier and 0.05 to 1.0 parts by weight of the polymerization initiator with respect to 100 parts by weight of the resin component. In the method for producing an acrylonitrile-butadiene-styrene thermoplastic resin composition, 20 to 50% by weight of butadiene-based rubber polymer and 50 to 80% by weight of styrene-acrylonitrile (SAN) resin as main components; And 0.5 to 15 parts by weight of a styrene-acrylonitrile (emulsified SAN) resin having a weight average molecular weight of 1,000,000 to 4,000,000 prepared by emulsion polymerization with respect to 100 parts by weight of the main component as a minor component. A method for producing an acrylonitrile-butadiene-styrene thermoplastic resin composition, characterized in that. According to claim 7, wherein the styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with the reactive emulsifier of the acrylonitrile-butadiene-styrene thermoplastic resin composition, characterized in that the emulsion polymerization at 70 ℃ or less Manufacturing method. The acrylonitrile-butadiene-styrene thermoplastic resin composition according to claim 8, wherein the styrene-acrylonitrile (emulsified SAN) resin prepared by emulsion polymerization with the reactive emulsifier is emulsion-polymerized at 40 to 50 ° C. Manufacturing method.