KR100822152B1 - Method for preparation of weather resistance acrylonitrile-ethylene-propylene-rubber-styrene with high heat resistance and impact resistance - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing weatherable acrylonitrile-ethylenepropylene rubber-styrene (AES) resins, and furthermore, to the production of AES resins comprising styrene monomers, acrylonitrile monomers and ethylene propylene rubbers. A method for producing an AES resin, comprising using a continuous block polymerization method comprising adding a monomer and polymerizing at a reaction temperature of 90 to 130 ° C. and two steps of polymerizing at a reaction temperature of 130 to 160 ° C. will be.

According to the present invention, there is an effect of providing a weather resistant AES resin excellent in heat resistance and impact resistance.

Thermoplastic, AES resin, block polymerization, ethylene propylene rubber (EPR, EPDM), maleic anhydride

Description

METHODS FOR PREPARATION OF WEATHER RESISTANCE ACRYLONITRILE-ETHYLENE-PROPYLENE-RUBBER-STYRENE WITH HIGH HEAT RESISTANCE AND IMPACT RESISTANCE}

The present invention relates to a method for producing weatherable AES resin, and more specifically, to the styrene-based monomer, acrylonitrile-based monomer and ethylene propylene-based rubber by adding maleic anhydride and using a continuous bulk polymerization method to provide heat resistance and impact resistance. A method for producing this excellent weather resistance AES resin.

Acrylonitrile-butadiene-styrene resins (hereinafter referred to as 'ABS resins') are thermoplastic resins that are used in many fields because of their excellent strength and moldability. However, ABS resin has a drawback in that the hydrogen of the methyl group adjacent to the remaining double bond in the molecule due to the butadiene component becomes an initiation point of the oxidation reaction by the action of light or oxygen, causing the main chain to react, resulting in poor weather resistance. In particular, in addition to generating whitening or cracking of the surface of the resin, this is a cause of lowering various performances of the ABS resin. The addition of UV stabilizers, coating, plating, etc. are generally used to make the resin with balanced weatherability while maintaining the excellent properties of the ABS resin.

Therefore, a number of resins have been developed in which the butadiene component, which is a cause of deterioration, is replaced with a rubber that does not have an unsaturated bond. One of them is an AES resin manufactured using ethylene propylene rubber instead of butadiene.

AES resin is obtained by copolymerizing styrene, acrylonitrile and the like with ethylene propylene rubber (EPR) and ethylene propylene nonconjugated diene three-dimensional copolymer (EPDM) which are substantially free of unsaturated bonds in the main chain thereof. Graft copolymers. Compared to ABS resins using conjugated diene rubber, resistance to ultraviolet rays, oxygen, and ozone is remarkably good.

In addition, as the market for automobile plastics gradually increases, resins requiring both heat resistance and weather resistance are required. However, ABS resins listed above have a disadvantage of poor weather resistance. AES resins have excellent weather resistance but low heat resistance. There are restrictions. Therefore, the present invention is to describe a method for preparing a weather resistant resin having excellent heat resistance and impact resistance by copolymerizing maleic anhydride in an AES resin.

Examples of the method for preparing AES resin, which is a thermoplastic resin, include emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, suspension and bulk polymerization, and emulsion and bulk polymerization. Can be. Among these methods, the emulsion polymerization method and the bulk polymerization method are mainly used in the production site. AES resin prepared by the emulsion polymerization method has an average particle size of 0.2 to 1.5 ㎛ in the dispersed phase in the continuous styrene-acrylonitrile copolymer (SAN copolymer), and has good mechanical properties and gloss. However, due to the nature of the emulsion polymerization process, emulsifiers and flocculants, which must be used, are not completely removed in the flocculation and dehydration process but remain in the final product to cause deterioration of physical properties, and it is difficult to treat contaminated water used as a polymerization medium. In addition, since the process of flocculation and dehydration after polymerization is required separately, it is less economical than the bulk polymerization which is a continuous process.

In the bulk polymerization, a predetermined amount of ethylene propylene rubber is dissolved in a solution in which a fixed ratio of styrene monomer and acrylonitrile monomer are dissolved in a reaction medium, followed by heating after mixing an appropriate amount of a polymerization initiator, a molecular weight regulator and other additives. By polymerization. As the polymerization proceeds, SAN is formed as a copolymer of styrene-based monomers and acrylonitrile-based monomers as the polymerization proceeds, and at this time, the styrene-based monomer and acrylonitrile-based monomers are dissolved and reacted with ethylene propylene-based rubber. To produce a copolymer. The resulting SAN copolymer forms two phases without mixing with the rubber dissolved in the reaction medium from the beginning of the reaction to make the entire polymerization solution non-uniform. In the heterogeneous phase, the rubber phase dissolved in the polymerization solution forms a continuous phase at the beginning of the polymerization reaction with low conversion rate, but the upper blood of the copolymer of styrene or styrene derivatives and acrylonitrile or acrylonitrile derivatives increased as the reaction proceeds. If is greater than the upper blood of the rubber in the polymerization solution, the former copolymer forms a continuous phase. This phenomenon is called phase inversion, and the point where the volume of the copolymer phase and the rubber phase become equal is called phase inversion time. After the phase inversion occurs, the rubber phase becomes a dispersed phase to form rubber particles in the finally prepared resin. Thus prepared AES resin is excellent in moldability, weather resistance, impact resistance has been applied to various fields such as home appliances, office equipment parts, automobile parts and outdoor facilities.

U.S. Patent No. 4,438,171 discloses a process for producing AES resin by reaction extrusion of styrene acrylonitrile resin and ethylene propylene diene rubber in the presence of a radical initiator. Thus prepared resin has a disadvantage in that the mechanical properties are lowered due to the lack of compatibility between the rubber and the matrix resin than the AES resin produced by the polymerization process.

U.S. Patent No. 4,814,388 discloses a process for preparing an AES resin by copolymerizing styrene and acrylonitrile by solution polymerization under ethylene propylene rubber having a specific polydispersity index (PDI) and ethylene propylene diene rubber under toluene as a reaction medium. US Patent No. 3,984, 496 discloses a process for preparing AES resin by solution polymerization using various reaction media. The resin composition prepared as described above has a disadvantage in that mechanical properties are excellent but heat resistance is poor. In addition, since an excess solvent is used, chain transfer to the solvent is inevitable, and thus the molecular weight of the polymer is lower than that of other polymerization methods and the polymerization rate is also slow. In addition, the process of recovering the solvent is complicated and the production cost is more expensive than the bulk polymerization method.

US Patent No. 2,914,505 discloses a process for preparing terpolymers of styrene, acrylonitrile and maleic anhydride monomers, and blending the resins with olefinic rubbers to produce resins with excellent heat and weather resistance. . However, there are disadvantages in that the rubber particles of the blended resin are non-uniform, so that the rigidity and impact strength are inferior.

US Patent No. 4,262,096 discloses a method for preparing ABS resin by copolymerizing styrene, acrylonitrile and maleic anhydride monomers with butadiene-based rubber. However, the resin produced in this way is excellent in heat resistance due to excessive use of maleic anhydride, but the resin itself is brittle and has a weak impact resistance as well as a poor weather resistance which is weakness of butadiene rubber.

In order to solve the problems of the prior art as described above, in the preparation of AES resin consisting of styrene monomer, acrylonitrile monomer and ethylene propylene rubber, a maleic anhydride monomer is added and continuous bulk It is an object of the present invention to provide a method for producing weatherable AES resin having excellent heat resistance and impact resistance by graft polymerization using a conventional method.

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

In order to achieve the above object, the present invention is a method for producing AES resin consisting of styrene monomer, acrylonitrile monomer and ethylene propylene rubber, 5 to 10 parts by weight of maleic anhydride monomer is added, It provides a method for producing AES resin characterized by using a continuous block polymerization method comprising the step of polymerization at 90 to 130 ℃ and the polymerization at a reaction temperature of 130 to 160 ℃.

Hereinafter, the present invention will be described in detail.

A method for preparing the AES resin of the present invention is a graft copolymer of maleic anhydride monomer in ethylene propylene rubber (EPR, EPDM) in order to increase the heat resistance, but a continuous process including a two-step polymerization process step according to the reaction temperature range It is characterized by the polymerization by the bulk polymerization method.

The AES resin may be prepared in a mixed solution in which 40 to 60 parts by weight of styrene monomer, 10 to 30 parts by weight of acrylonitrile monomer and 5 to 10 parts by weight of maleic anhydride are dissolved in 10 to 45 parts by weight of a solvent. To the polymerization solution prepared by dissolving 5 to 12 parts by weight of ethylene propylene rubber (EPR, EPDM), 0.01 to 0.1 parts by weight of a polymerization initiator and 0.01 to 1 part by weight of a molecular weight regulator are added to the reactor continuously, in a step of 90 to 130 ° C. Polymerizing at a reaction temperature of, and a step of producing an AES resin comprising the step of polymerization at a reaction temperature of 130 to 160 ℃ in two steps.

In the method of preparing the AES resin, after the two-stage polymerization step, the polymerization conversion rate is 65 to 90% at a temperature of 200 to 260 ° C. in a volatilizer to remove the solvent, the reaction medium and the reaction medium into pellets of AES resin. It is a manufacturing method comprising the step of manufacturing.

The solvent is used to lower the viscosity of the polymerization solution, and may be selected from one or more selected from the group consisting of toluene, ethylbenzene and xylene, and toluene is preferable. The content of the solvent is preferably 10 to 45 parts by weight. If the content is less than 10 parts by weight, it is difficult to adjust to a high viscosity, if the content exceeds 45 parts by weight there is a problem that can not effectively control the form of the rubber particles produced during the polymerization process.

The styrene-based monomers used as the raw material of the AES resin include styrene, α-methylstyrene, p-bromostryene, p-methylstryene, and p-chloro. Styrene (p-chlorostryene), o-bromostryene (o-bromostryene) and a mixture thereof may be selected from the group, the content is preferably 40 to 60 parts by weight.

The acrylonitrile-based monomer may be selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile, the content of which is preferably 10 to 30 parts by weight.

The maleic anhydride monomer is to impart heat resistance, and may be selected from the group consisting of maleic anhydride, maleic acid, maleic monoester, and maleic diester. It is preferable that the content is 5 to 10 parts by weight. When the content is less than 5 parts by weight, the heat resistance of the resin is lowered, and when it exceeds 10 parts by weight, the resin is brittle and there is a problem that the impact resistance is lowered.

The ethylene propylene rubber is to improve impact resistance and weather resistance, and is selected from the group consisting of ethylene-propylene rubber (ethylene-propylene rubber, EPR) and ethylene-propylene-diene rubber (EPDM) It is preferable that the content is 5 to 12 parts by weight. When the content is less than 5 parts by weight, the impact resistance is lowered. When the content is more than 12 parts by weight, the compatibility between the styrene-acrylonitrile (SAN) copolymer resin and the rubber in application is not good, resulting in reduced graft reaction. There is a problem that the appearance is reduced.

As the diene monomer added to the EDPM, ethylene norbornene (ENB), dicyclopentadiene (DCPE) or hexadiene (HD) may be selected.

The ethylene propylene rubber is preferably ethylene content of 45 to 80 parts by weight, propylene content of 20 to 55 parts by weight, diene monomer content of 0 to 13 parts by weight.

The ethylene propylene rubber is preferably a weight average molecular weight of 150,000 to 400,000, more preferably 200,000 to 350,000.

The polymerization initiator uses an organic peroxide initiator to control the graft reaction and conversion rate, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane {1,1-bis (t -butylperoxy) -3,3,5-trimethyl cyclohexane}, 1,1-bis (t-butylperoxy) cyclohexane {1,1-bis (t-butylperoxy) cyclohexane}, 1,1-bis (t- Butylperoxy) -2-methyl cyclohexane {1,1-bis (t-butylperoxy) -2-methyl cyclohexane} and 2,2-bis (4,4-di-t-butylperoxy cyclohexyl) propane { 2,2-bis (4,4-di-t-butylperoxy cyclohexyl) propane}. The content of the initiator is preferably 0.01 to 0.1 parts by weight. If the content is less than 0.01 parts by weight, it is impossible to proceed with polymerization, and it is difficult to balance the physical properties of the entire resin. If the content is more than 0.1 parts by weight, the process may be disadvantageous and dangerous due to excessive viscosity increase. There is a problem.

The molecular weight modifier is for controlling the viscosity of the resin, the size of the particles and the distribution of particles, a thiol-based compound consisting of t-dodecyl mercaptan (tertiary-dodecyl mercaptan) and n-octyl mercaptan (n-octyl mercaptan) Can be selected from. The content of the molecular weight modifier is preferably 0.01 to 1 part by weight. When the molecular weight regulator is the opposite of the initiator occurs, if the content is less than 0.01 parts by weight, excessive viscosity rise is disadvantageous due to the process, resulting in a decrease in the physical properties of the resin, when the content exceeds 1 part by weight polymerization does not proceed There is a problem that it is difficult to balance the physical properties of the entire resin.

The present invention also provides an AES resin produced by the above production method.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

8 parts by weight of ethylene propylene diene (EPDM) rubber was dissolved in a mixed solution of 49.6 parts by weight of styrene monomer, 12.4 parts by weight of acrylonitrile and 5 parts by weight of maleic anhydride in 25 parts by weight of toluene as a reaction solvent. 0.05 parts by weight of 1,1-bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane {1,1-Bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane} A polymerization solution was prepared. The prepared polymerization solution was introduced into a 26 L reactor at a rate of 12 L / hr, polymerized at a temperature of 125 ° C. in the first reactor, and polymerized at a temperature of 130 ° C. in the second reactor, respectively in a third reactor and a fourth reactor. When the polymerization was carried out at a temperature of 140 and 145 ° C. to reach a polymerization conversion of 75%, the unreacted monomer and the reaction medium were removed at a temperature of 230 ° C. in a volatilizer to prepare pellets of AES resin.

The physical properties of the prepared AES resin was measured, and the results are shown in Table 1 below.

Example 2

The preparation was carried out in the same manner as in Example 1, except that 47.6 parts by weight of styrene, 11.9 parts by weight of acrylonitrile, and 7.5 parts by weight of maleic anhydride were added when preparing the polymerization solution.

Example 3

The preparation was carried out in the same manner as in Example 1, except that 45.6 parts by weight of styrene, 11.4 parts by weight of acrylonitrile, and 10 parts by weight of maleic anhydride were added when preparing the polymerization solution.

Comparative Example 1

The preparation was carried out in the same manner as in Example 1, except that 53.6 parts by weight of styrene and 13.4 parts by weight of acrylonitrile were added when preparing the polymerization solution.

Comparative Example 2

The preparation was carried out in the same manner as in Example 1, except that 51.6 parts by weight of styrene, 12.9 parts by weight of acrylonitrile, and 2.5 parts by weight of maleic anhydride were added when preparing the polymerization solution.

Comparative Example 3

The preparation was carried out in the same manner as in Example 1, except that 41.6 parts by weight of styrene, 10.4 parts by weight of acrylonitrile, and 15 parts by weight of maleic anhydride were added when preparing the polymerization solution.

The physical properties of the AES resins prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

* Izod Impact: measured by ASTM D256 method.

* Tensile strength and elongation: measured by ASTM D638 method.

* Weather resistance: The retention rate was calculated by exposing it to a Sunshine Weatherometer (Wather-6, Suga Tester, WEL-6XL-DC) using carbon arc as a light source for 1,000 hours and measuring the Izod impact strength.

* Heat resistance: measured by ASTM D648 (heat deformation temperature), D1525 (softening point) method.

division Example Comparative example One 2 3 One 2 3 Maleic anhydride content in the polymerization solution (parts by weight) 5 7.5 10 0 2.5 15 Tensile Strength (kg / cm ² ) 436 439 439 423 432 442 Elongation (%) 21 20 19 25 24 12 Impact Strength (1/4 ', 23 ℃) (kgcm / cm) 23.7 22.3 20.6 25.3 24.8 7.1 Weatherability [impact strength retention rate (%)] 78 78 80 75 76 85 Heat resistance Heat deflection temperature (℃) 98 102 105 84 87 112 Softening point (℃) 109 110 114 93 97 121

Through Table 1, the AES resin of Examples 1 to 3 prepared by adding 5 to 10 parts by weight of maleic anhydride monomer, maleic anhydride-based monomer, Comparative Example 1 and without the addition of maleic anhydride Compared with Comparative Example 2 prepared by adding a small amount of maleic anhydride, it was excellent in heat resistance and weather resistance, and compared with Comparative Example 3 prepared by adding an excessive amount of maleic anhydride, it was confirmed that the impact strength was excellent.

As described above, according to the present invention, there is an effect of providing a weather resistant AES resin excellent in heat resistance and impact resistance.

Although described in detail above with reference to the specific embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such variations and modifications belong to the appended claims. It is also natural.

Claims (12)

In the manufacturing method of the AES resin which consists of a styrene monomer, an acrylonitrile monomer, and an ethylene propylene rubber, AES characterized by using a continuous block polymerization method comprising adding 5 to 10 parts by weight of a maleic anhydride monomer, polymerizing at a reaction temperature of 90 to 130 ° C. and polymerizing at a reaction temperature of 130 to 160 ° C. Method for producing a resin. The method of claim 1, The AES resin may be prepared in a mixed solution in which 40 to 60 parts by weight of styrene monomer, 10 to 30 parts by weight of acrylonitrile monomer and 5 to 10 parts by weight of maleic anhydride are dissolved in 10 to 45 parts by weight of a solvent. To the polymerization solution prepared by dissolving 5 to 12 parts by weight of ethylene propylene rubber, 0.01 to 0.1 parts by weight of a polymerization initiator and 0.01 to 1 part by weight of a molecular weight regulator were added to the reactor continuously, and polymerization was carried out at a reaction temperature of 90 to 130 ° C. in one step. And a step of polymerization at a reaction temperature of 130 to 160 ° C. in two steps. The method of claim 2, The solvent is a method for producing an AES resin, characterized in that at least one selected from the group consisting of toluene, ethylbenzene and xylene. The method of claim 2, The ethylene propylene rubber is selected from the group consisting of ethylene-propylene rubber (ethylene-propylene rubber, EPR) and ethylene-propylene-diene rubber (EPDM), and has an ethylene content of 45 to 80 wt% , A propylene content of 20 to 55% by weight, the weight average molecular weight of the production method of AES resin, characterized in that 150,000 to 400,000. The method of claim 4, wherein The ethylene-propylene-diene comprises 0 to 13% by weight of at least one diene monomer selected from the group consisting of ethylene norbornene (ENB), dicyclopentadiene (DCPE) and hexadiene (HD). The manufacturing method of AES resin made into. The method of claim 2, The styrene monomers are styrene, α-methylstryene, p-bromostryene, p-methylstryene, p-chlorostryene , o-bromost styrene (o-bromostryene) and a method for producing an AES resin, characterized in that at least one selected from the group consisting of a mixture thereof. The method of claim 2, The acrylonitrile-based monomer is an acrylonitrile (acrylonitrile), methacrylonitrile (methacrylonitrile) and ethacrylonitrile (ethacrylonitrile) method for producing an AES resin, characterized in that at least one selected from the group consisting of. The method of claim 2, The maleic anhydride monomer is selected from the group consisting of maleic anhydride, maleic acid, maleic acid monoester and maleic diester. Method for producing AES resin. The method of claim 2, The polymerization initiator is 1,1-bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane {1,1-bis (t-butylperoxy) -3,3,5-trimethyl cyclohexane}, 1, 1-bis (t-butylperoxy) cyclohexane {1,1-bis (t-butylperoxy) cyclohexane}, 1,1-bis (t-butylperoxy) -2-methyl cyclohexane {1,1-bis (t-butylperoxy) -2-methyl cyclohexane} and 2,2-bis (4,4-di-t-butylperoxy cyclohexyl) propane {2,2-bis (4,4-di-t-butylperoxy cyclohexyl ) propane} an organic peroxide selected from the group consisting of at least one AES resin production method. The method of claim 2, The molecular weight regulator is a t-dodecyl mercaptan (tertiary-dodecyl mercaptan) and n-octyl mercaptan (n-octyl mercaptan) A method for producing an AES resin, characterized in that at least one selected from the group consisting of compounds (n-octyl mercaptan). AES resin comprising: a) 40 to 60 parts by weight of a styrene monomer; b) 10 to 30 parts by weight of acrylonitrile monomers; c) 5 to 10 parts by weight of maleic anhydride monomer; And d) 5 to 12 parts by weight of ethylene propylene-based rubber; The polymerization is AES resin, characterized in that the bulk polymerization comprising the step of polymerization at 90 to 130 ℃ and the polymerization at 130 to 160 ℃. The method of claim 11, The ethylene propylene rubber is an ethylene-propylene rubber or an ethylene-propylene-diene rubber, has a weight average molecular weight of 150,000 to 400,000, an ethylene content of 45 to 80% by weight, a propylene content of 20 to 55% by weight, and optionally a diene AES resin, characterized in that the monomer is 0 to 13% by weight.