KR100358234B1 - Transparent thermoplastic resin composition excellent in weather resistance and a method of manufacturing the same - Google Patents

Abstract

The present invention relates to a transparent thermoplastic resin composition having excellent weather resistance, wherein the resin composition comprises 10 to 30 parts by weight of an alkyl acrylate rubber polymer latex, 40 to 70 parts by weight of an alkyl methacrylate compound or an acrylic acid alkyl ester compound, and an aromatic vinyl compound. 10 to 30 parts by weight and 1 to 20 parts by weight of the vinyl cyan compound.

In this resin composition, the thermoplastic resin composition is excellent in physical properties such as transparency, weather resistance, chemical resistance, and impact resistance.

Description

Transparent thermoplastic resin composition excellent in weatherability and its manufacturing method

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent thermoplastic resin composition having excellent weather resistance and a method for producing the same, and more particularly, to a transparent thermoplastic resin composition having excellent physical properties such as impact resistance, chemical resistance, and workability, and excellent in weatherability and transparency, and a manufacturing method thereof. .

[Prior art]

Recently, as the industry is advanced and life is diversified, a lot of research has been conducted to give high functionalities such as weather resistance, transparency, processability, impact resistance, etc. to materials used to actively promote differentiation of product models.

Among these techniques, transparency techniques for plastic materials include a method using a transparent polycarbonate resin, a method using a transparent polymethyl methacrylate resin (US Pat. No. 3,787,522 and Japanese Patent Laid-Open No. 63-42940 and HIPS ( high impact polystyrene) is known (European Patent No. 0,733,252).

However, the method using the polycarbonate resin has excellent transparency and impact resistance at room temperature, but has a problem of weak chemical resistance, poor impact resistance at low temperature, and lack of workability, and thus has limitations in application to large parts. In addition, the method using the polymethyl methacrylate resin has excellent transparency and processability, but the impact resistance is extremely weak and has a limitation in application. In addition, the method of imparting transparency to the HIPS resin has a problem in that chemical resistance and scratch resistance are lowered and weather resistance is not good.

In order to solve such problems, a method of preparing a transparent resin having excellent impact resistance, chemical resistance, and processability by graft copolymerization of monomers such as methyl methacrylate, styrene, and acrylonitrile on a polybutadiene rubber polymer has been proposed. (US Pat. No. 4,767,833). However, this method has a problem of poor weather resistance. In order to solve this weather resistance problem, a method using an acrylate-styrene-acrylonitrile (ASA) resin having an excellent balance of physical properties such as impact resistance, chemical resistance and processability has been proposed (US Patent No. 3,426,101), ASA resin is an opaque material due to its resin properties, and thus has a limitation in application to a material requiring transparency.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a transparent thermoplastic resin composition excellent in weather resistance, excellent weather resistance, chemical resistance, impact resistance and other physical properties.

Another object of the present invention is to provide a method for producing a transparent thermoplastic resin composition excellent in weather resistance that can easily produce the thermoplastic resin composition.

[Means for solving the problem]

In order to achieve the above object, the present invention is 10 to 30 parts by weight of an alkyl acrylate rubber polymer latex; 40 to 70 parts by weight of a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound; Provided is a transparent thermoplastic resin composition having excellent weather resistance including 10 to 30 parts by weight of an aromatic vinyl compound and 1 to 20 parts by weight of a vinyl cyan compound.

In addition, the present invention is the first polymerization step by adding 0.2 to 0.6 parts by weight of the emulsifier and 0.05 to 0.3 parts by weight of the reaction initiator to 10 to 30 parts by weight of alkyl acrylate rubber latex and alkyl methacrylate compound or alkyl acrylate to the polymer 40 to 70 parts by weight of ester compound, 10 to 30 parts by weight of aromatic vinyl compound, 1 to 20 parts by weight of vinyl cyan compound, 0.2 to 1.2 parts by weight of emulsifier, 0.2 to 0.6 parts by weight of molecular weight regulator and 0.05 to 0.6 parts by weight of reaction initiator It provides a method for producing a transparent thermoplastic resin composition excellent in weather resistance comprising the step of secondary polymerization.

Hereinafter, the present invention will be described in more detail.

The transparent thermoplastic resin composition of the present invention is made by graft copolymerization of an alkyl acrylate rubber polymer latex having excellent weather resistance and a methyl methacrylate component having excellent physical properties such as an acrylonitrile component having excellent chemical resistance, a styrene component having excellent workability, and impact resistance. It is manufactured. In addition, the transparent thermoplastic resin composition of the present invention by adjusting the content and mixing ratio of the components used, the refractive index of the alkyl acrylate rubber polymer latex and the methyl methacrylate component, aromatic vinyl compound and vinyl cyan compound graft copolymerized thereto It was prepared by optimizing the refractive index of the mixture.

The transparent thermoplastic resin composition of the present invention is a large diameter alkyl acrylate rubber polymer latex and methacrylic acid alkyl ester compound or acrylic acid alkyl ester compound, aromatic vinyl compound, vinyl cyan compound having a particle size of 2500 to 5000 kPa by emulsion polymerization method. It is prepared by grafting copolymerization.

The refractive index of the monomer mixture used at this time absolutely affects transparency, and this refractive index is controlled by the amount of the monomer used and the mixing ratio. That is, in order to obtain an excellent transparent resin, the refractive index of the alkyl acrylate rubber polymer used as the seed and the refractive index of the entire mixture to be grafted to the copolymer should be adjusted to a similar degree, so the amount of the monomer used and the mixing ratio are very important. If the refractive index of the alkyl acrylate rubber polymer and the refractive index of the entire mixture grafted to the copolymer are different, it becomes opaque. That is, if the refractive index difference between the refractive index of the alkyl acrylate rubber polymer used as the seed and the total grafted compound is 0.005 or more, the transparency is lowered and is not suitable for the present invention.

In the present invention, the refractive index difference of the mixture of the refractive index of the alkyl acrylate rubber latex and the compound grafted thereto (the mixture of the alkyl methacrylate compound or the acrylic acid alkyl ester compound, the aromatic vinyl compound and the vinyl cyan compound) It is preferable that it is 0-0.004. At this time, the refractive index of each component used is about 1.467 of butyl acrylate, about 1.49 of methyl methacrylate, about 1.59 of styrene, and about 1.518 of acrylonitrile. The graft addition method of each component in the graft copolymerization reaction may be performed by the method of daily administration of each component and the method of continuous (sequential) administration of all or part of the components. It takes a complex form.

Referring to the process of producing a transparent thermoplastic resin composition of the present invention in more detail as follows.

1) Manufacture of large diameter alkyl acrylate rubber polymer latex

a) Preparation of Crosslinked Alkyl Acrylate Rubber Polymer Latex

0.5 to 4 parts by weight of alkyl acrylate monomer, 0.005 to 0.3 part by weight of crosslinking agent, 0.05 to 0.4 part by weight of electrolyte, 0.04 to 0.2 part by weight of reaction initiator and 60 to 80 parts by weight of ion-exchanged water at about 60 to 80 ° C. at about 0.5 to 1 Crosslinking reaction for a time to produce a crosslinked alkyl acrylate rubber polymer latex.

The alkyl acrylate monomer may be any alkyl acrylate such as methyl acrylate, ethyl acrylate, propyl acrylate or butyl acrylate, but butyl acrylate is mainly used.

As the crosslinking agent, any compound capable of crosslinking with an alkyl acrylate monomer may be used, but representative examples thereof include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1 , 6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylol methane triacrylate, and the like can be used.

The electrolyte may be any compound that can give electrons to other compounds, and representative examples thereof may include NaHCO ₃ , Na ₂ S ₂ O ₇ , and K ₂ CO ₃ .

As the reaction initiator, any compound capable of causing a crosslinking reaction may be used, and representative examples thereof may include inorganic or organic peroxide compounds, and both water-soluble initiators and oil-soluble initiators may be used. Specific examples include water-soluble initiators such as potassium persulfate, sodium persulfate and ammonium persulfate, and oil-soluble initiators such as cumene hydroperoxide and benzoyl peroxide.

b) Preparation of Large Diameter Alkyl Acrylate Rubber Polymer Latex

100 parts by weight of the crosslinked alkyl acrylate rubber polymer latex obtained by the above method, 0.01 to 0.1 parts by weight of the first mixed emulsion solution and the reaction initiator were administered at 60 to 70 ° C. for 1 to 3 hours to emulsify and polymerize the large diameter alkyl acrylate rubber. Polymer latex is prepared. The first mixed emulsion solution is 6 to 29 parts by weight of alkyl acrylate, 6 to 29 parts by weight of aromatic vinyl compound, 0.01 to 0.07 part by weight of emulsifier, 0.005 to 0.3 part by weight of crosslinking agent, 0.005 to 0.4 part by weight of electrolyte, and 0.01 to grafting agent. It is prepared by mixing 0.07 parts by weight and 20 to 40 parts by weight of ion-exchanged water.

This step is performed to increase the size of the crosslinked alkyl acrylate rubber polymer latex obtained by the above method, so it is carried out using the same alkyl acrylate monomer used in the crosslinking reaction. As such, when the size of the alkyl acrylate rubber polymer latex is increased, impact resistance is improved. In addition, the aromatic vinyl compound may be a compound selected from the group consisting of styrene, α-styrene, o-ethyl styrene, p-ethyl styrene and vinyl toluene.

The emulsifier emulsifies the monomer and the reaction initiator which are not mixed with a surfactant having a hydrophobic group and a hydrophilic group at the same time so that a polymerization reaction can occur. Nonionic and anionic surfactants are used as emulsifiers that play such a role, and representative examples thereof include aqueous solutions of derivatives of carboxylic acid metal salts such as fatty acid metal salts or rosin acid metal salts having from ₁₂ to ₂₀ carbon atoms. An aqueous solution of can be used. Specific examples thereof include dioctylsulfo succinate. As the grafting agent, aryl methacrylate, triaryl isocyanurate, triarylamine, diarylamine and the like can be used.

The latex pH of the prepared large-diameter alkyl acrylate rubber polymer is preferably in the range of 5 to 10, and the particle size is preferably 2500 to 5000 Pa. If the latex particle size of the alkyl acrylate rubber polymer is less than 2500 GPa, the impact resistance is lowered, and if it is more than 5000 GPa, the gloss and thermal stability are lowered, which is not preferable.

2) Preparation of Thermoplastic Resin Composition

The process of manufacturing a transparent thermoplastic resin composition is divided into the emulsion polymerization process which is a primary polymerization process, and the grafting polymerization process which is a secondary polymerization process as follows.

a) emulsion polymerization process

10 to 30 parts by weight of the large-diameter alkyl acrylate rubber polymer latex prepared by the above method was subjected to 80 to 100 parts by weight of ion-exchanged water, 0.2 to 0.6 parts by weight of the emulsifier and 0.05 to 0.3 parts by weight of the reaction initiator at 50 to 80 ° C. Emulsion polymerization for 1 hour.

The emulsifiers used in the polymerization reaction are alkylaryl sulfonates, alkali methylalkyl sulfates, sulfonated alkyl esters, soaps of fatty acids such as sodium oleate, alkali salts of rosin acid, etc., and these may be used alone or as a mixture of two or more thereof. It is possible. As the molecular weight regulator, tertiary dodecyl mercaptan is mainly used, and as the reaction initiator, peroxides such as cumene hydroperoxide, diisopropylbenzenehydro peroxide, persulfate, sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, Oxidation-reduction catalyst systems made of a mixture with a reducing agent such as ferrous sulfate, dextrose, sodium pyrolate, sodium sulfite and the like can be used.

2) Graft Polymerization Reaction

The mixed emulsion solution is continuously administered to the polymer produced by the emulsion polymerization reaction for 3 to 7 hours while the temperature is raised to 70 to 80 ° C. The mixed emulsion solution is 60 to 80 parts by weight of ion-exchanged water, 0.2 to 0.6 parts by weight of an emulsifier, 40 to 70 parts by weight of an alkyl methacrylate compound or an acrylic acid alkyl ester compound, 10 to 30 parts by weight of an aromatic vinyl compound, a vinyl cyan compound It is prepared by mixing 1 to 20 parts by weight, 0.2 to 0.6 parts by weight of a molecular weight regulator, and 0.05 to 0.3 parts by weight of a reaction initiator.

Subsequently, the temperature of the mixture is raised to 75 to 85 ° C., and then the graft polymerization reaction is performed for about 0.5 to 1.5 hours. The polymerization conversion rate of the latex obtained is 98% or more.

Subsequently, an antioxidant and a stabilizer are administered to this latex in order to obtain a dendritic polymer, and then a flocculant is added at a temperature of 80 ° C. or higher and dehydrated and dried.

The vinyl cyan compound may be a compound selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. As the antioxidant, any compound capable of preventing oxidation of a polymer may be used, and representative examples thereof include phenol, bisphenol, polyphenol, 2,6-di-t-butyl-4-methylphenol, and tri (nonyl). Phenyl) phosphite and the like. As the stabilizer, any compound capable of preventing the oxidation reaction by ultraviolet rays or heat may be used.

The transparent thermoplastic resin produced in this manner is very excellent in physical properties such as weather resistance, impact resistance, chemical resistance, processability.

EXAMPLE

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

(Example 1)

1) Manufacture of large diameter alkyl acrylate rubber polymer latex

a) Preparation of Crosslinked Alkyl Acrylate Rubber Polymer Latex

70 parts by weight of ion-exchanged water, 1 part by weight of butyl acrylate, 0.02 part by weight of ethylene glycol dimethacrylate, 0.1 part by weight of sodium bicarbonate, and 0.04 part by weight of potassium persulfate were added to a nitrogen-substituted polymerization reactor, and the temperature was raised to 70 ° C. The crosslinked reaction was carried out for 1 hour to prepare a crosslinked alkyl acrylate rubber polymer latex.

2) Preparation of Large Diameter Alkyl Acrylate Rubber Polymer Latex

30 parts by weight of ion-exchanged water, 0.5 parts by weight of dioctylsulfo succinate, 13 parts by weight of butyl acrylate, 6 parts by weight of styrene, 0.12 parts by weight of ethylene glycol dimethacrylate, 0.04 parts by weight of aryl methacrylate, and sodium hydrogencarbonate 0.1 Parts by weight were mixed. 0.05 parts by weight of potassium persulfate and the crosslinked seed obtained by the above-described method were added to the mixture at 70 ° C. for 2 hours in succession to prepare a large diameter alkyl acrylate rubber polymer latex.

The particle size of the latex thus obtained was measured using a Nicomp 370 HPL by the dynamic laser light scattering method, and the measured particle diameter was 4000 mm 3. In addition, the pH of the prepared latex was 8, polymerization conversion was about 98%.

2) Preparation of Transparent Thermoplastic Resin Composition

a) emulsion polymerization reaction

90 parts by weight of ion-exchanged water, 0.2 parts by weight of sodium oleate emulsifier, 0.048 parts by weight of sodium pyrophosphate, 0.012 parts by weight of dextrose, sulfur in 20 parts by weight of a large diameter alkyl acrylate rubber polymer prepared by the above method in a nitrogen-substituted polymerization reactor. 0.001 parts by weight of ferrous topicate and 0.04 parts by weight of cumene hydroperoxide were collectively administered at 70 ° C to perform an emulsion polymerization reaction.

2) Graft Polymerization Reaction

The mixed emulsion solution was continuously administered to the product obtained by the emulsion polymerization while raising the temperature to 73 ° C for 5 hours. The mixed emulsion solution is 70 parts by weight of ion-exchanged water, 0.4 parts by weight of sodium oleate, 66.64 parts by weight of methyl methacrylate, 10.36 parts by weight of styrene, 3 parts by weight of acrylonitrile, 0.25 parts by weight of tertiary dodecyl mercaptan, pyrophosphoric acid 0.048 parts by weight sodium, 0.012 parts by weight dextrose, 0.001 parts by weight ferrous sulfate and 0.10 parts by weight cumene hydroperoxide.

Subsequently, the temperature of the mixture was further raised to 76 ° C., and then aged for 1 hour to terminate the graft polymerization reaction. At this time, the polymerization conversion was 99.5% and solid coagulation was 0.1%. The latex was coagulated with an aqueous calcium chloride solution and washed to obtain a powder.

(Example 2)

It carried out substantially the same as Example 1 except having changed the composition ratio of each component used by emulsion polymerization and the graft polymerization reaction as shown in Table 1 below.

(Comparative Example 1-2)

It carried out similarly to Example 1 except having changed the composition ratio of each component used by the emulsion polymerization and the graft polymerization reaction as shown in Table 1 below.

The solid content of the graft latex prepared by the method of Example 1-2 and Comparative Example 1-2 was calculated by Equation 1 below and the results are shown in Table 1 below.

[Equation 1]

Solid coagulation content (%) = (weight of product coagulum in reaction tank [g] / weight of total rubber and monomer [g]) × 100

When the solidified solid content is more than 0.7% by weight, the latex stability is extremely low, and due to the large amount of the solidified material, it is difficult to obtain a graft copolymer suitable for the present invention. As shown in Table 1, the graft latex prepared by the method of Example 1-2 and Comparative Example 1-2 can be seen that the latex stability is excellent because the content of the solid content is about 0.1% by weight.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Emulsification Polymerization Ion exchange water 90 100 95 91 Large Diameter Alkylacrylate Rubber Polymers 20 20 20 20 Sodium oleate 0.2 0.2 0.2 0.2 Methyl methacrylate 0 16.48 0 0 Styrene 0 2.52 0 0 Acrylonitrile 0 One 0 0 Class 3 dodecyl mercaptan 0 0.2 0 0 Sodium pyrophosphate 0.048 0.048 0.048 0.048 Dextrose 0.012 0.012 0.012 0.012 Ferrous sulfate 0.001 0.001 0.001 0.001 Cumene Hydroperoxide 0.04 0.04 0.04 0.04 Dosing method Batch administration Batch administration Batch administration Batch administration Reaction time 1 hours Graft polymerization Ion exchange water 70 60 65 69 Sodium oleate 0.4 0.3 0.35 0.42 Methyl methacrylate 66.64 49.44 72.96 59.6 Styrene 10.36 7.56 5.04 15.4 Acrylonitrile 3 3 2 5 Class 3 dodecyl mercaptan 0.4 0.3 0.3 0.3 Sodium pyrrolate 0.048 0.048 0.048 0.048 Dextrose 0.012 0.012 0.012 0.012 Ferrous sulfate 0.001 0.001 0.001 0.001 Cumene Hydroperoxide 0.1 0.12 0.1 0.1 Dosing method Batch administration Batch administration Batch administration Batch administration Reaction time 5 hours 5 hours 5 hours 5 hours Polymerization conversion rate 99.50% 99.00% 99.50% 99.70% Solid Coagulation 0.10% 0.15% 0.10% 0.10%

0.1 parts by weight of lubricant and 0.2 parts by weight of antioxidant were administered to 100 parts by weight of the graft copolymer prepared by the method of Example 1-2 and Comparative Example 1-2, using a twin screw extruder at a cylinder temperature of 210 ° C. Prepared in pellet form. The pellet was injection molded to prepare a specimen. Notched Izod impact strength, flow index, haze valuse, chemical resistance and weather resistance of this specimen were measured in the following manner and the results are shown in Table 2.

1) Notched Izod Impact Strength: ASTM D-256

2) Flow index: ASTM D-1238

3) Haze value (transparency): ASTM D-1003

4) Chemical resistance:

After the specimen was left for 14 days in ethanol solution, its shape was observed.

5) Weather Resistance:

The weather resistance was measured by using a weather-o-meter device and a xenon lamp under the conditions of temperature of 63 ° C., illuminance of 0.35 W / m 2 and humidity of 50%. .

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Notch Izod Impact Strength [kg · cm / cm] 12 11 12 11 Flow index [g / 10min] 11 12 10 9 Haze value (transparency) 4 (excellent) 4.5 (excellent) 26 (translucent) 21 (translucent) Chemical resistance Great Great Great Great Weather resistance Great Great Great Great

As shown in Table 2, the specimen prepared from the resin composition of Example 1-2 is not only excellent in impact strength, chemical resistance and weather resistance, but also excellent in flow index, it is excellent in workability, and also very excellent in transparency. Can be.

As described above, the thermoplastic resin composition of the present invention is excellent in physical properties such as transparency, weather resistance, chemical resistance, and impact resistance.

Claims (11)

10-30 parts by weight of alkyl acrylate rubber polymer latex; 40 to 70 parts by weight of a methacrylic acid alkyl ester compound or an acrylic acid alkyl ester compound; 10 to 30 parts by weight of the aromatic vinyl compound; And 1 to 20 parts by weight of a vinyl cyan compound Transparent thermoplastic resin composition excellent in weatherability containing. The method of claim 1, A transparent thermoplastic resin composition having a difference in refractive index between the alkyl acrylate rubber polymer latex and the refractive index of the methacrylic acid alkyl ester compound or the mixture of the acrylic acid alkyl ester compound, the aromatic vinyl compound and the vinyl cyan compound is 0 to 0.004. The method of claim 1, The alkyl acrylate rubber polymer has an average particle diameter of 2500 to 5000 mm 3, and has a pH of 5 to 10 transparent thermoplastic resin composition. The method of claim 1, A transparent thermoplastic resin composition wherein the aromatic vinyl compound is selected from the group consisting of styrene, α-methylstyrene, o-ethylstyrene, p-ethylstyrene and vinyltoluene. The method of claim 1, Transparent vinyl resin composition wherein the vinyl cyan compound is selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. Primary polymerization by adding 0.2 to 0.6 parts by weight of an emulsifier and 0.05 to 0.3 parts by weight of a reaction initiator to 10 to 30 parts by weight of an alkyl acrylate rubber latex; And 40 to 70 parts by weight of the methacrylic acid alkyl ester compound or the acrylic acid alkyl ester compound, 10 to 30 parts by weight of the aromatic vinyl compound, 1 to 20 parts by weight of the vinyl cyan compound, 0.2 to 1.2 parts by weight of the emulsifier, and 0.2 to 0.6 to the polymer. Addition of 0.05 to 0.6 parts by weight of the reaction part and the reaction initiator to the second polymerization step The manufacturing method of the transparent thermoplastic resin composition excellent in the weatherability containing. The method of claim 6, 40 to 70 parts by weight of an alkyl methacrylate compound or an acrylic acid alkyl ester compound, 10 to 30 parts by weight of an aromatic vinyl compound, 1 to 20 parts by weight of a vinyl cyan compound and 0.2 to 0.6 parts by weight of a molecular weight modifier are further added to the rubber latex. The manufacturing method which performs a secondary polymerization step. The method of claim 6, The alkyl acrylate rubber polymer has an average particle diameter of 2500 to 5000 kPa, and has a pH of 5 to 10. The method of claim 6, The aromatic vinyl compound is selected from the group consisting of styrene, α-methylstyrene, o-ethylstyrene and p-ethylstyrene, vinyl toluene. The method of claim 6, The vinyl cyan compound is selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. The method of claim 6, Wherein said emulsifier is at least one compound selected from the group consisting of alkylaryl sulfonates, alkali methylalkyl sulfates, sulfonated alkyl esters, fatty acid soaps and rosin salts.