KR19980026560A - Polypropylene resin composition - Google Patents

Abstract

The present invention relates to a polypropylene resin composition excellent in paintability that can be applied to parts requiring coating, such as bumpers for automobiles, the polypropylene resin composition of the present invention (a) 50 to 100% by weight of polypropylene resin, (b) ethylene / 0-50% by weight of -olefin copolymer elastomer, (c) 1-50 parts by weight of polyolefin resin grafted into a likelihood group with respect to 100 parts by weight of the mixture of (a) and (b), (d) It contains 0.1-30 weight part of compounds represented by following formula I with respect to 100 weight part of mixtures of a) and (b).

[Equation 1]

Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6.

Description

Polypropylene resin composition

The present invention relates to a polypropylene resin composition, and more particularly, to a polypropylene resin composition excellent in paintability that can be applied to parts requiring coating such as bumpers for automobiles.

In general, polypropylene compositions have been known to be difficult to print, adhere to, and paint because they are nonpolar. Accordingly, various methods have been proposed to form a stable coating layer on a molded article of the polypropylene composition, and a method of improving compatibility with paint is mainly used by forming a primer or an undercoat layer between the polypropylene composition and the paint. have.

However, this method requires a pretreatment process that requires cleaning with halogenated hydrocarbons such as 1,1,1-trichloroethane (hereinafter referred to as TCE), and also because of the high primer price, the cost of the final product increases. In addition to its shortcomings, the use of TCE has been saved because it destroys the earth's ozone layer.

Meanwhile, other methods include surface treatment methods such as chromic acid treatment, flame treatment, corona treatment, and plasma treatment to improve printing and paintability on the flat surface of the polypropylene composition, but in terms of economic performance and environmental problems, Still not satisfied.

Accordingly, an object of the present invention is to provide a polypropylene resin composition having excellent paintability as well as solving the problems of the conventional methods described above.

Polypropylene resin composition of the present invention for achieving the above object,

(a) 50 to 100% by weight of polypropylene resin,

(b) ethylene / 0-50% by weight of -olefin copolymer elastomer,

(c) 1 to 50 parts by weight of a polyolefin resin grafted into a likelihood group with respect to 100 parts by weight of the mixture of (a) and (b), and

(d) 0.1-30 weight part of compounds represented by following formula (I) with respect to 100 weight part of mixtures of said (a) and (b).

Formula I

Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6.

In addition, the polypropylene resin composition of the present invention,

(a) 50 to 100% by weight of polypropylene resin,

(b) ethylene / 0-50% by weight of -olefin copolymer elastomer, and

(c) 1-50 weight part of polyolefin resin which has a functional group represented by following formula II with respect to 100 weight part of mixtures of said (a), (b).

Formula II

Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6.

Hereinafter, the configuration of the present invention in more detail.

As described above, the polypropylene composition has been known to be difficult to print, adhere and paint because it has a non-polar, and accordingly various methods have been proposed to form a stable coating layer on the molded article of the polypropylene composition, but a very satisfactory result Failed to bring it.

The present inventors have conducted research to modify polypropylene resins into functional groups in order to be able to coat them immediately without primer treatment after washing with a solvent such as water or alcohol instead of TCE in terms of environment and economy, and as a result, The above-mentioned object can be achieved with respect to the polypropylene resin modified as a group, as well as the specific polypropylene resin composition using the same.

In short, the polypropylene resin composition of the present invention,

(a) 50 to 100% by weight of polypropylene resin,

(b) ethylene / 0-50% by weight of -olefin copolymer elastomer,

(c) 1 to 50 parts by weight of a polyolefin resin grafted into a likelihood group with respect to 100 parts by weight of the mixture of (a) and (b), and

(d) 0.1-30 weight part of compounds represented by following formula (I) with respect to 100 weight part of mixtures of said (a) and (b).

Formula I

Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6.

As mentioned above, the polypropylene resin composition of the present invention is composed of (a), (b), (c) and (d) components.

In the present invention, as the polypropylene resin of component (a), it is a crystalline polypropylene homophile, a propylene / ethylene random copolymer, a propylene / ethylene block copolymer, propylene / ethylene / -Olefin terpolymers and the like can be used. The melt index of the polypropylene resin is not particularly limited, but is preferably 5 to 100 g / 10 minutes, and more preferably 10 to 50 g / 10 minutes. The content of component (a) is preferably 50 to 100% by weight, more preferably 60 to 80% by weight based on the total amount of components (a) and (b). If the content is less than 50% by weight, the physical properties are reduced.

Ethylene / of component (b) Olefin copolymer elastomers include ethylene and propylene, butene-1, hexene-1, octene-1 and the like. Copolymers with olefins or terpolymers with dienes such as dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene, methylene-novodene, ethylidene-norbornene, and the like, And a propylene copolymer with a copolymer of ethylene and 1-octene is preferable. Ethylene / The ethylene content of the -olefin copolymer elastomer is preferably 40 to 90% by weight, more preferably 50 to 80% by weight, and the pattern viscosity [ML _{1 + 4} , 100 ° C] is in the range of 10 to 100. More preferably 20 to 70. The content of component (b) is preferably 0 to 50% by weight based on the total amount of the components (a) and (b). If the content exceeds 50% by weight can result in a decrease in physical properties.

As the polyolefin resin grafted with the functional group of component (c), ethylene, propylene homopolymer, propylene / ethylene random or block copolymer, ethylene / butene-1 copolymer, ethylene / octene-1 copolymer and the like can be used. And products grafted to functional groups such as maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, glycidyl methacrylate, glycidyl acrylate, etc., alone or in mixtures, may be used. Preference is given to resins modified with maleic anhydride in polypropylene resins. The number average molecular weight of the modified polyolefin resin of component (c) is preferably in the range of 1,000 to 40,000, particularly preferably 2,000 to 20,000, and the acid value is preferably in the range of 7 to 60. The content of the modified polyolefin resin is not particularly limited, but is preferably 1 to 50 parts by weight, more preferably 2 to 30 parts by weight based on 100 parts by weight of the total amount of the components (a) and (b). If the content is less than 1 part by weight, it is difficult to form a stable coating layer on the final compound, and if it exceeds 50 parts by weight, low temperature impact and tensile strength are lowered and hygroscopicity is increased, resulting in silver phenomena during injection.

Component (d) is a reactive phenol-formaldehyde resin of the resol type, represented by the above formula (I), preferably 0.1 to 30 parts by weight, more preferably 100 parts by weight of the total amount of the components (a) and (b). The following is 0.2-15. If the content of component (d) is less than 0.1 parts by weight, the desired coating performance cannot be obtained. If the content of the component (d) is more than 30 parts by weight, the physical properties are deteriorated, as well as the adhesiveness on the surface of the injection molding. In particular, component (d) is reacted with component (d) during compounding to obtain a polyolefin resin modified with a phenol resin as shown in the following formula (II).

In the polypropylene resin composition of the present invention, a heat stabilizer, a sunscreen agent, a nucleating agent, a flame retardant, a glass fiber, a colorant, a talc, a foaming agent, a crosslinking agent, etc. may be used in addition to the above components (a) to (d).

On the other hand, in the present invention, 50 to 100% by weight of the component (a) polypropylene resin, (b) ethylene / To 0 to 50% by weight of the -olefin copolymer elastomer, 1 to 50 parts by weight of the polyolefin resin modified with the functional group represented by the following formula II is added to 100 parts by weight of the mixture of (a) and (b). Similar effects can be obtained. As for content of the functional group of said Formula (c), 0.6-10 weight% is more preferable with respect to polyolefin resin.

Formula II

Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6.

Polypropylene resin composition according to the present invention can be produced in a conventional compounding equipment Banbury mixer, kneader in a mill or a twin screw extruder. In the present invention, the components (a) to (b) are melt-mixed in a ZSK-40 ø (Germany WP company) twin screw extruder to produce pellets. The polypropylene resin composition thus prepared is manufactured into a molded article by injection, extrusion, compression molding, or the like.

An advantage of the molded article of the polypropylene resin composition according to the present invention is that after surface treatment with a solvent containing no water or halogen, it can be applied immediately without primer treatment. Halogen-free solvents have a boiling point of 150 ° C. or less and include ethanol, isopropyl alcohol, hexane, heptane, cyclone hexane, toluene, acetone, methyl ethyl ketone, ethyl acetate, kerosene, and the like. Cyclohexane is more preferred.

The molded article is treated with water or a solvent and then air dried and painted with melamine paint, urethane paint or acrylic paint. Double melamine paints and urethane paints are more preferred. Melamine paints include polyester melamine paints that are crosslinked and are often used for automotive bumpers, while urethane paints include acrylic urethane paints and polyester urethane paints and one- or two-component urethane paints. After painting, the molded product is usually baked for about 20 minutes to 1 hour between about 80 ° C and 150 ° C. Although the polypropylene resin composition according to the present invention may be well coated without a primer treatment, the polypropylene resin composition may be well coated even if the primer is treated before the coating as in the conventional method. However, there is a characteristic that the coating can be performed well without cleaning the surface with a halogen-containing solvent such as trichloroethane before primer treatment.

The features of the present invention will be described in more detail with reference to the following Examples and Comparative Examples, but this does not limit the scope of the present invention.

EXAMPLES 1-4

70 parts by weight of a propylene-ethylene block copolymer having an ethylene content by weight and a melt index of 16 g / 10 minutes, and an ethylene-propylene copolymer having an ethylene content of 52% by weight and a pattern viscosity (ML _{1 + 4} , 100 ° C.) of 45 30 parts by weight of an elastomer (hereinafter referred to as EPR), 5, 10, 20, 30 parts by weight of a polypropylene resin (hereinafter referred to as MA-PP) modified with maleic anhydride having an acid value of 47 and a number average molecular weight of 4,000, and Phenol resin (trade name; SP-1045, manufactured by Schenectardy, USA) was mixed in a Henschel mixer according to the formulation of Table 1 below, and then the mixture was added to the main hopper of the ZSK-40 ø twin screw extruder (L / D = 38). Injected at 30 kg per hour to melt kneading and reaction between 160 ℃ to 210 ℃ to prepare a polypropylene resin composition in a pellet form. The pellets thus prepared were injected into a plate of 355 mm × 100 mm × 3 mm at 210 ° C. using an injection molding machine (Promax 150, manufactured by Korea Dongshin Hydraulic). The extruded plate was cut into a square of 100 mm, then treated with water using a gauze, and then dried with air. Then, after mixing the two-component urethane paint (trade name: Corretan Enamel (UT595), manufactured by Korea Chemical Co., Ltd.) with a curing agent and a solvent, spray coating to a thickness of 30 μm to 40 μm and baking for 120 ° C. for 40 minutes, and then room temperature Left for 2 hours. The coated specimen (100 mm x 100 mm x 3 mm) was cut into a 5 mm x 5 mm square into a shank board shape, and then a plastic adhesive tape (50 mm wide polypropylene tape, manufactured by Daeil Tape Korea) was manufactured. And pulled it out at high speed and repeated it twice. At this time, the initial adhesion performance was evaluated by converting the number of square coating layers remaining on the specimen, and the results are shown in Table 1 below.

Comparative Example 1

The same method as in Example 1 was performed except that no phenol resin was added. The results are shown in Table 1 below.

Comparative Example 2

MA-PP was not added, except that 5 parts by weight of the phenol resin was added in the same manner as in Example 1, and the results are shown in Table 1 below.

Comparative Example 3

Except that the surface was not treated with water was carried out in the same manner as in Example 2, the results are shown in Table 1 below.

TABLE 1

EXAMPLES 5-8

The polypropylene resin used in Example 1 and the pattern viscosity (ML _{1 + 4} , 100 ℃) is 42 and the ratio of the ethylene-propylene copolymer elastomer having an ethylene content of 75% by weight as shown in Table 2 And, except that the content of the phenolic resin in 2 parts by weight was changed in the same manner as in Example 2, except that the content of the phenolic resin in 2 parts by weight was prepared in the same manner as in Example 2. , Initial adhesive performance was evaluated and the results are shown in Table 2 below.

TABLE 2

Example 9

60 parts by weight of polypropylene resin used in Example 1, 40 parts by weight of ethylene / octene copolymer elastomer having an occlusal content of 55 and a pattern viscosity (ML _{1 + 4} , 100 ° C.) of 55%, and an acid value. 10 parts by weight of a polypropylene resin modified with maleic anhydride having a number average molecular weight of 4,000 and 2 parts by weight of a phenol resin (trade name; SP-1045, manufactured by Schenectardy, USA) in a Henschel mixer, and then After the preparation in the same manner as in Example 1, after surface treatment with a variety of solvents as shown in Table 3, the initial adhesion performance was evaluated.

TABLE 3

[Examples 10-12]

70 parts by weight of the polypropylene resin used in Example 1 and the pattern viscosity (ML _{1 + 4} , 100 ℃) is 42 and the total amount of the functional group consisting of phenol resin 30 parts by weight of EPR with 75 ethylene content of 75% by weight 2 A polypropylene resin having a weight% (hereinafter referred to as phenol-PP) was added as shown in Table 4 below and mixed uniformly in a Henschel mixer, and then the mixture was mixed with a ZSK-40 ø twin screw extruder (L / D = 38). It was injected into the main hopper at 30 kg per hour and melt kneaded between 160 ℃ to 210 ℃ to prepare a polypropylene resin composition in a pellet form. The pellets thus prepared were injected into a plate of 355 mm × 100 mm × 3 mm at 210 ° C. using an injection molding machine (Promax 150, manufactured by Korea Dongshin Hydraulic). This extruded plate was cut into a square of 100 mm, then surface treated with gauze with water, and then dried with air.

Then, after mixing the two-component urethane paint (trade name; Coretan Enamel (UT595), manufactured by Korea Chemicals Co., Ltd.) with a curing agent and a solvent, spray coating it to a thickness of 30 μm to 40 μm and baking it at 120 ° C. for 45 minutes, and then room temperature. After leaving for 2 hours at to evaluate the initial adhesive performance, the results are shown in Table 4 below.

[Comparative Example 4]

Except that phenol-PP was not added was carried out in the same manner as in Example 10, the results are shown in Table 4 below.

[Comparative Example 5]

Except that the surface was not treated with water was carried out in the same manner as in Example 10, the results are shown in Table 4 below.

TABLE 4

Therefore, the polypropylene resin composition of the present invention is excellent in paintability regardless of the treatment of the primer for parts requiring coating such as automobile bumpers, and does not clean the surface with a halogen-containing solvent such as trichloroethane before the primer treatment. There is an advantage that can be painted well without.

Claims (13)

(a) 50 to 100% by weight of polypropylene resin, (b) ethylene / 0-50% by weight of -olefin copolymer elastomer, (c) 1 to 50 parts by weight of a polyolefin resin grafted into a likelihood group with respect to 100 parts by weight of the mixture of (a) and (b), and (d) Polypropylene resin composition containing 0.1-30 weight part of compounds represented by following formula I with respect to 100 weight part of mixtures of said (a) and (b): Formula I Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6. The process of claim 1 wherein ethylene / The olefin copolymer elastomer has an ethylene content of 40 to 90% by weight and a pattern viscosity of [ML _{1 + 4} , 100 ° C] of 10 to 100. The polyolefin resin grafted with the functional group of component (c) is selected from unsaturated carboxylic acid and maleic anhydride, and is modified. The number average molecular weight of the modified polyolefin resin is 1,000-40,000, and the acid value is 7. Polypropylene resin composition, characterized in that in the range of ~ 60. The method according to claim 3, wherein the polyolefin resin is a component alone or a mixture selected from the group consisting of ethylene, propylene homopolymer, propylene / ethylene random or block copolymer, ethylene / butene-1 copolymer and ethylene / octene-1 copolymer A polypropylene resin composition characterized in that it is grafted with functional groups such as maleic anhydride, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, glycidyl methacrylate or glycidyl acrylate. The method of claim 1 wherein the polyolefin resin is polypropylene, polyethylene and ethylene / Polyolefin resin composition, characterized in that it is selected from the group consisting of -olefin copolymers. The method of claim 1 wherein the polypropylene resin of component (a) is a crystalline polypropylene homopolymer, propylene / ethylene random copolymer, propylene / ethylene block copolymer, propylene / ethylene / Polyolefin resin composition, characterized in that it is selected from the group consisting of olefin terpolymers. A polypropylene resin composition, characterized in that the melt index of the polypropylene resin of component (a) is 5 to 100 g / 10 minutes. The process according to claim 1, wherein the ethylene / -Olefin copolymer elastomers such as ethylene and propylene, butene-1, hexene-1 or octene-1 A polypropylene resin, characterized in that it is a copolymer with an olefin or with a diene such as dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene, methylene-novodene, ethylidene-norbornene and the like Composition. The polypropylene resin composition of claim 1, wherein the polypropylene resin composition further comprises an additive selected from the group consisting of a heat stabilizer, a sunscreen agent, a nucleating agent, a flame retardant, a glass fiber, a colorant, a talc, a foaming agent, and a crosslinking agent. . (a) 50 to 100% by weight of polypropylene resin, (b) ethylene / 0-50% by weight of -olefin copolymer elastomer, and (c) A polypropylene resin composition comprising 1 to 50 parts by weight of a polyolefin resin having a functional group represented by the following formula II with respect to 100 parts by weight of the mixture of (a) and (b): Formula II Wherein X ₁ , X ₂ are the same or different and are —CH ₂ — or —CH ₂ —O—CH ₂ — radicals, R is an alkyl, aryl, or alkenyl radical containing 4 to 16 carbon atoms, n Is an integer between 0 and 6. The method of claim 10, wherein the ethylene / The olefin copolymer elastomer has an ethylene content of 40 to 90% by weight and a pattern viscosity of 10 to 100. The polypropylene resin composition according to claim 10, wherein the polyolefin resin has a content of 0.6 to 10% by weight of the functional group represented by Formula II. The method of claim 10, wherein the polyolefin resin is polypropylene, polyethylene and ethylene / The propylene copolymer composition selected from the group consisting of -olefin copolymers and used alone or in combination.