KR960006624B1 - Thermoplastic resin composition - Google Patents

Abstract

Mixed thermoplasic composition of polyolefin/copolymer resin and styrene/copolymer resin has high impact resistance, good moldability and high strength characteristics and is composed of : polyolefin resin 40-90 wt%; copolymer polyolefin resin 2-40 wt% which has carboxyl group(acryl acid, methacrylic acid, maleic acid, citracon acid); styrene resin 5-70 wt% which has a rubber; copolymer styrene resin 3-40 wt% which has epoxy group(glycidyl acrylate, arylglycidyl eter). Here, polyolefin means LLDPE, LDPE, HDPE, PP, EVA, PP-copolymer. And styrene resin means ABS, HIPS, acrylonitril-styrene-acrylate.

Description

Thermoplastic resin composition

The present invention relates to a thermoplastic resin composition having excellent stiffness, impact resistance, and molding processability, and more particularly, to a modified polyolefin resin, a modified polyolefin resin, a styrene-based resin including rubber, and a rubber containing epoxy as a functional group. The present invention relates to a thermoplastic resin composition which is composed of styrene resins and has improved usability by producing a polyolefin-graft-styrene compound at an interface between a polyolefin resin and a styrene resin through half of a modified olefin resin and a modified styrene resin in an extruder. .

Polyolefin resins have been used for many purposes such as daily necessities, sundries, packaging films, sheets, etc. as polyolefin resins are inexpensive, workable, and chemically stable. However, they have insufficient rigidity. It has a flaw that appears. On the other hand, styrene-based resin is excellent in stiffness and shrinkage does not occur during molding processing, it is excellent in dimensional stability surface, there is a drawback of poor chemical resistance.

Attempts have been made to add styrene-based resins to olefin resins in order to make up for the disadvantages and to take advantage of each of these resins. However, when the two resins are simply blended, the compatibility between the two resins is poor, resulting in phase separation, which lowers the rigidity, and causes layer separation during extrusion.

Therefore, various attempts have been made to increase the compatibility of the above two resins. Typically, a block copolymer and a graft copolymer may be used as a compatibilizer. The use of a styrene-diene or styrene-hydrogenated diene system as a usable agent as a block copolymer has been studied for a long time. For example, a method using a styrene-hydrogenated butadiene block copolymer by Fate et al. (J Poly. Sci.:Polym, Phys. 27,775 (1989)), a method of mixing two block copolymers with very different styrene contents in US Pat. Nos. 5,003,005 and 5,003,007, substituted with maleic anhydride in Japanese Patent 92-50248. There is a method of using styrene-hydrogenated butadiene-styrene block copolymer, and a method of using styrene-hydrogenated butadiene-styrene block copolymer of Japanese Patent No. 92-45140.

As a method of using the graft copolymer as a compatibilizer, a method of using a polyolefin-graft-polystyrene copolymer of European Patent (EP) 43535, and a polypropylene-graft-polystyrene copolymer of Japanese Patent No. 92-33,906 is used. There is a way.

When the block copolymer or the graft copolymer is properly used as a compatibilizer as described above, the size of the dispersed phase can be made to about 1 μm, but the interfacial adhesion is insufficient, resulting in phase separation between the interfaces when there is a high shear force such as injection molding. . This is because the block or graft copolymer is present at the interface between the olefin resin and the styrene resin in the equilibrium state after a long time, but during the extrusion, most of the compatibilizer is insufficient because of the high viscosity and relatively large molecular weight. It forms its own micelles rather than interfaces, which causes layer separation under high shear forces.

Meanwhile, as a compatibilizer, there is a method of preparing a graft polymer by reaction by introducing a reaction group at the ends of two polymers, for example, polypropylene and oxa containing maleic anhydride in US Pat. Nos. 4,590,241 and 4,864,002. A styrene resin containing a sleepy group was used. In this case, in the preparation of polypropylene containing maleic anhydride, changes in the properties of the polypropylene molecules and the basement and the above reactions are slow at the temperature in a conventional extruder, so effective adhesion is expected. The impact strength is lowered because it is difficult and difficult to include thermoplastic elastomers such as block copolymers.

Accordingly, the present inventors have studied diligently to solve such a problem, and as a result, the modified olefin resin having a carboxyl group, which is a polar functional group, is reacted in the presence of the modified styrene resin, and thus the compatibility of the polyolefin resin and the styrene resin is always constant, and has a high impact strength. It has been found that the composition can be prepared.

The object of the present invention

(A) 40 to 90% by weight of polyolefin resin,

(B) 2 to 40% by weight of a modified polyolefin resin obtained by grafting a compound containing a carboxyl group as a polar functional group to the polyolefin resin of the component (A),

(C) 5 to 70% by weight of a styrene resin containing a rubber, and

(D) A thermoplastic resin composition comprising 3 to 40% by weight of a modified styrene resin containing an epoxy as a functional group while containing a rubber.

Hereinafter, the present invention will be described in detail.

As the polyolefin resin (A) component used in the present invention, ethylene copolymers such as linear low density polyethylene, low density polyethylene, ultra low density polyethylene, high density polyethylene, polypropylene, comonomer-containing polypropylene, ethylene vinyl acetate, and ethylene ethyl acrylate Can be used, Preferably it is polypropylene and copolypropylene.

The modified polyolefin of component (B) is prepared by copolymerization of an organic compound having a functional group with a polyolefin resin, and the compound containing a functional group used here is a compound containing a carboxyl group which is a polar functional group, and is composed of acrylic acid, methacrylic acid and maleic acid. , Itaconic acid, or citraconic acid can be used, most preferably acrylic acid.

The method for grafting the functional group-containing compound to the polyolefin resin includes a method in which the functional group-containing compound mentioned above is melt mixed with the polyolefin resin in a molten state in the presence of a radical initiator to be grafted in addition to the copolymerization method described above. Peroxides such as benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide and azo compounds such as azobis isobutyronitrile can be used, and the amount of the radical initiator is 0.01-100 parts by weight of the polyolefin resin. 1 part by weight is suitable. On the other hand, the usage-amount of a functional group containing compound is 0.05-30 weight part with respect to 100 weight part of polyolefin resin, Preferably 0.1-15 weight part is suitable.

As the styrene resin containing the rubber of component (C), acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene-acrylate copolymer, high impact polystyrene, and the like may be used. Butadiene-styrene copolymers.

The modified styrene resin of the component (D) is produced by copolymerization of a compound containing an epoxy functional group with a styrene resin containing a rubber. Epoxy-containing organic compounds used here include glycidyl methacrylate, glycidyl acrylate, glycidyl itaconate, allylglycidyl ether or 2-methyl glycidyl ether, most preferably glyc Cydyl methacrylate.

The copolymerization is preferably a solution, suspension or emulsion polymerization. In view of economics, suspension polymerization or emulsion polymerization is preferable. Emulsion polymerization has a disadvantage in that a relatively larger amount is consumed than the desired epoxy content ratio because the epoxy ring is ring-opened in the use and flocculation step of the emulsifier. The amount of the epoxy functional group-containing compound is suitably 0.05 to 30 parts by weight, preferably 0.1 to 15 parts by weight with respect to 100 parts by weight of the styrene resin. Meanwhile, in order to further improve impact resistance and glossiness, it is preferable to use two kinds of latex having different sizes of rubber particles. The size of rubber particles is 0.25-0.5 μm for large diameters and 0.07-0.2 μm for small diameters. desirable.

On the other hand, when the content of component (A) is 40% by weight or less, chemical resistance is remarkably lowered because the polyolefin resin does not exist continuously.

The amount of component (B) or component (D) is suitably about 1 to 100 parts by weight based on 100 parts by weight of component (A) or component (C), and when less than 1 part by weight, the role of a compatibilizer is insufficient, resulting in layer separation. If more than 100 parts by weight of the polyolefin-graft-polystyrene compound is mass-produced to increase the viscosity, the workability is significantly reduced, as well as the formation of a microstructure for dispersibility, a sharp decrease in physical properties occurs.

If necessary, various additives such as antioxidants, ultraviolet absorbers, antistatic agents, weather stabilizers, lubricants, and pigments may be appropriately added to the composition of the present invention.

Each of the above components can be dry blended and trained simultaneously or each component can be separately introduced into the first and second hoppers as needed. The training can be carried out at a temperature of usually 200 to 280 ° C, preferably 210 to 260 ° C, using a single screw or twin screw extruder or the like.

Hereinafter, the present invention will be described in detail with Examples and Comparative Examples, but the scope of the present invention is not limited thereto. Referring to the test conditions used in the present invention and the characteristics of each component are as follows.

1.Extension Strength: ASTM D638

2. Izod impact strength: ASTM D648, notch (1/8 inch)

3. Heat Deflection Temperature: ASTM D648 (4.6kg / ㎠, 1/4 inch)

4. Fluidity: ASTM D1238 (200 ℃, 5kg)

PE: Low density polyethylene (density: 0.918 g / cm 2, M.I (200 ° C., 5 kg) = 7 g / 10 min)

MPE: modified polyethylene (acrylic acid graft polyethylene)

PP: Polypropylene (M.I (200 ℃, 5kg) = 10g / 10min)

MPP: modified polypropylene (acrylic acid graft polypropylene)

ABS: Acrylonatril-butadiene-styrene copolymer

ABS-GMA-1: acrylonitrile butadiene styrene graft glycidyl methacrylate copolymer (emulsion polymerization)

ABS-GMA-2: Acrylonitrile Butadiene Styrene Grafort Glycidyl Methacrylate Copolymer (suspension polymerization)

(Manufacture example 1)

Preparation of Modified Polypropylene

100 parts by weight of polypropylene, 6 parts by weight of acrylic acid and 0.1 parts by weight of dicumyl peroxide used as component (A) were dry blended in a Henschel mixer for about 5 minutes, and then extruded in a twin screw extruder at a range of 220 to 250 ° C. Prepared.

(Manufacture example 2)

Fabrication of Modified Polyethylene

100 parts by weight of polyethylene, 6 parts by weight of acrylic acid and 0.1 parts by weight of dicumyl peroxide used as component (A) were carried out in the same manner as in Preparation Example 1 to prepare pellets.

(Manufacture example 3)

Preparation of Acrylonitrile Butadiene Styrene Graft Glycidyl Methacrylate (Emulsion Polymerization)

105 parts by weight of distilled water and latex having a different size of rubber (butadiene) particles (average particle size of 0.1 µm in diameter and 0.5 µm in average diameter of large-diameter rubber), 40 parts of styrene monomer, 12 parts by weight of acrylonitrile Part and 3.0 parts by weight of glycidyl methacrylate using a 0.5 part by weight of an emulsifier and 0.1 part by weight of an initiator, followed by primary polymerization at 70 ° C., followed by 30 parts by weight of distilled water, 25 parts by weight of styrene monomer, 10 parts by weight of acrylonitrile, 5 parts by weight of glycidyl methacrylate, 1.0 part by weight of an emulsifier and 0.2 part by weight of an initiator were continuously polymerized at 70 ° C.

(Manufacture example 4)

Preparation of acrylonitrile butadiene styrene graft glycidyl methacrylate (suspension polymerization)

After dissolving 7 parts by weight of polybutadiene rubber in 88 parts by weight of styrene monomer and 5 parts by weight of glycidyl methacrylate to prepare a prepolymer of styrene-rubber containing epoxy functional group, 100 parts by weight of the prepolymer solution, 200 parts by weight of distilled water, and suspending agent 0.3 A weight part and 0.15 weight part of tricalcium phosphates were added and superposed | polymerized at 110 degreeC.

(Example 1)

40 parts by weight of polypropylene, 25 parts by weight of ABS, 20 parts by weight of modified polypropylene obtained in Preparation Example 1, 15 parts by weight of ABS-GMA-1 obtained in Preparation Example 3, and the barrel temperature was adjusted to 200 to 240 ° C. It was extruded in a twin screw extruder to prepare a wetlet. The obtained pellets were prepared at a temperature of 210 ° C. using an injection molding machine, and then various physical properties were measured according to ASTM. The measurement results are shown in Table 1.

(Example 2)

Except for changing the content of polypropylene and ABS-GMA-1 as shown in Table 1 was carried out in the same manner as in Example 1, the physical properties of the measurement results are shown in Table 1.

(Examples 3 to 4)

Except for using ABS-GMA-2 obtained in Preparation Example 4 instead of ABS-GMA-1 was carried out in the same manner as in Examples 1 and 2, respectively, the results of the measurement of the physical properties are shown in Table 1.

(Comparative Examples 1 to 2)

In order to observe the effect of no addition and content change of the modified polypropylene obtained in Preparation Example 1 was carried out in the same manner as in Example 1, and the results of the measurement of physical properties are shown in Table 1. .

(Examples 5 to 6)

Except for using the modified polyethylene obtained in Preparation Example 2 instead of the modified polypropylene was carried out in the same manner as in Examples 1 and 2, respectively, and the results of measurement of the physical properties are shown in Table 1.

(Example 7)

Except for using ABS-GMA-2 obtained in Preparation Example 4 instead of ABS-GMA-1 was carried out in the same manner as in Example 5, the physical properties of the measurement results are shown in Table 1.

(Comparative Examples 3 to 4)

In order to observe the effect of no addition and content change of the modified polyethylene obtained in Preparation Example 2 was carried out in the same manner as in Example 5 except that the content was changed as shown in Table 1, and the results of measuring the physical properties are shown in Table 1. .

TABLE 1

As can be seen from the above table, a thermoplastic resin composition having excellent impact resistance, molding processability and rigidity can be prepared by incorporating a modified polyolefin resin and a modified styrene resin into a polyolefin resin and a styrene resin.

Claims (7)

(A) 40 to 90% by weight of a polyolefin resin, (B) 2-40 weight% of modified polyolefin resin which grafted the compound containing the carboxyl group which is a polar functional group to the polyolefin resin of the said component (A), (C) 5 to 70% by weight of a styrene resin containing a rubber and (D) A thermoplastic resin composition comprising 3 to 40% by weight of a modified styrene resin containing an epoxy as a functional group while containing a rubber. The thermoplastic resin composition of claim 1, wherein the polyolefin resin is linear low density polyethylene, low density polyethylene, ultra low density polyethylene, high density polyethylene, homopolymer or copolymer of polypropylene, ethylene vinyl acetate or ethylene ethyl acrylate. The thermoplastic resin composition according to claim 1, wherein the amount of the compound containing a carboxyl group which is a polar functional group in the component (B) is 0.05-30 parts by weight based on 100 parts by weight of the polyolefin resin. The thermoplastic resin composition according to claim 1 or 3, wherein the compound containing a carboxyl group as the polar functional group is acrylic acid, methacrylic acid, maleic acid, itaconic acid or citraconic acid. The thermoplastic resin composition according to claim 1, wherein the amount of the epoxy functional group-containing compound in the component (D) is 0.05-30 parts by weight based on 100 parts by weight of the styrene resin. The compound according to claim 1 or 5, wherein the epoxy functional group-containing compound is glycidyl methacrylate, glycidyl acrylate, glycidyl itaconate, alkyl glycidyl ether or 2-methyl glycidyl ether. The thermoplastic resin composition characterized by the above-mentioned. The thermoplastic resin composition according to claim 1, wherein the styrene-based resin including rubber is acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene-acrylate copolymer or high impact polystyrene.