JPH08283488A - Polypropylene-based resin composition - Google Patents

Abstract

PURPOSE: To obtain a polypropylene-based resin composition capable of producing a molding having not only excellent surface processability but also improved rigidity-impact resistance balance. CONSTITUTION: This resin composition comprises (a) a polypropylene-based resin, (b) a hydroxy group-modified polypropylene-based resin modified by grafting 0.01-10wt.% of an organic compound containing at least one unsaturated bond in the molecule and a hydroxyl group to a polypropylene-based resin, (c) a copolymer of ethylene and an α-olefin and (d) a copolymer of ethylene and an α-olefin subjected to graft modification with 0.01-10wt.% of an unsaturated carboxylic acid and is obtained by blending 50-99wt.% of the components (a) and (b) with 50-1wt.% of the components (c) and (d) in a molten state. The resin composition can provide a molding having not only excellent surface processability but also improved heat resistance and impact resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition which can provide a molded article having improved surface workability such as paintability, printability and adhesiveness. In addition, the present invention relates to a polypropylene resin composition that can provide a molded product having improved impact strength.

[0002]

Polypropylene is inexpensive and has excellent mechanical properties, transparency, heat resistance, surface glossiness, chemical resistance, acid resistance and alkali resistance, and also injection molding, blow molding and various types of films. Since it is easy to mold by various molding methods such as molding, it is used in a large amount in a very wide range of applications.
It has a drawback that surface processing such as adhesion is difficult.
Further, polypropylene has a drawback that it has a smaller impact resistance than polyethylene and the like.

As a method for improving the surface workability of such polypropylene, for example, the surface of the polypropylene molded article may be modified by etching with an organic solvent such as trichloroethane to improve the surface workability. Further, in terms of materials, alcohols were added to an ethylene copolymer having an unsaturated carboxylic acid anhydride and an unsaturated ester compound as a comonomer, as described in JP-A-61-111346. A method of improving the surface workability and impact resistance of a molded article by blending a modified ethylene copolymer with an unmodified polypropylene has also been proposed. However, it has been found that sufficient surface workability cannot be obtained by the above-mentioned improvement method when trichloroethane cannot be used due to recent solvent regulations.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a polypropylene capable of forming a molded article having not only excellent surface workability but also improved rigidity-impact resistance balance. A resin composition is provided.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that polypropylene resins, hydroxyl group-modified polypropylene resins, ethylene copolymers, and unsaturated dicarboxylic acids. It is surprising that not only surface processability but also impact resistance can be dramatically improved by melt-kneading an ethylene-α-olefin copolymer modified with an acid anhydride and finely crosslinking the matrix-domain phase interface. The present invention has been reached by finding a phenomenon that should be observed.

That is, the present invention relates to (a) a polypropylene resin, and (b) an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group is 0.01
Hydroxyl group-modified polypropylene resin graft-modified with 10 to 10 wt% polypropylene resin, (c) 0.01 to 10 wt% graft-modified ethylene and α-olefin copolymer, and (d) unsaturated carboxylic acid Is a resin composition containing a copolymer of ethylene and α-olefin, and (b) a polypropylene resin and (b) an organic compound having at least one unsaturated bond in the molecule and having a hydroxyl group. (C) a copolymer of ethylene and α-olefin and (d) an unsaturated carboxylic acid based on 50 to 99% by weight of a hydroxyl group-modified polypropylene resin graft-modified with 0.01 to 10% by weight of a polypropylene resin. Of 0.01 to 10% by weight of graft-modified ethylene and α-olefin copolymer 50
To 1% by weight of melt-kneaded polypropylene resin composition, and (a) polypropylene resin, (b) an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group. Compound from 0.01 to
A hydroxyl group-modified polypropylene resin graft-modified with a 10 wt% polypropylene resin, (c) a copolymer of ethylene and α-olefin, and (d) 100 parts by weight of an ethylene copolymer, (e) A polypropylene-based resin composition comprising 0.01 to 5 parts by weight of a reaction accelerator and melt-kneading.

There are various polypropylene resins used in the present invention. For example, homo polypropylene, ethylene / propylene random polypropylene, ethylene / propylene block polypropylene,
Mixture of homo polypropylene and ethylene / propylene random polypropylene, mixture of homo polypropylene and ethylene / propylene block polypropylene, mixture of ethylene / propylene random polypropylene and ethylene / propylene block polypropylene, homo polypropylene and polyethylene and / or ethylene and carbon number A mixture of 4 to 12 α-olefin copolymer resins, ethylene / propylene random polypropylene and polyethylene and / or ethylene and α to C 4-12 α-
Mixture with olefin copolymer resin, ethylene / propylene block polypropylene and polyethylene and / or mixture of ethylene and α-olefin copolymer resin having 4 to 12 carbon atoms, homopolypropylene and ethylene / propylene random polypropylene and polyethylene and / Alternatively, a mixture of ethylene and an α-olefin copolymer resin having 4 to 12 carbon atoms, ethylene / polypropylene random polypropylene, ethylene / propylene block polypropylene and polyethylene, and / or ethylene and 4 to 1 carbon atoms.
A mixture with the α-olefin copolymer resin of 2 and the like can be mentioned. Among these, homopolypropylene, ethylene / propylene random polypropylene and ethylene / propylene block polypropylene are preferable from the viewpoint of mechanical strength, heat resistance and oil resistance, and these may be used alone or in combination of two or more kinds. You may use.
Examples of the copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms include ethylene / butene-1 copolymer, ethylene / 4-methylpentene-1 copolymer, ethylene / hexene-1 copolymer. Such as coalescing. Melt flow rate of these polypropylene resins (called MFR)
(230 ° C, load 2.16 kg) is 1.0 to 1000 g /
It is 10 minutes, preferably 2.0 to 500 g / 10 minutes, and more preferably 2.0 to 300 g / minute. These polypropylene resins are components that can exhibit heat resistance and mechanical strength in the composition of the present invention.

As the organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group, used in the present invention, 2-hydroxymethyl acrylate, 2-hydroxymethyl methacrylate, 2-hydroxymethyl methacrylate,
Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxyethyl ethoxy acrylate, 2-hydroxyethyl ethoxy methacrylate, dipropylene Examples thereof include glycol monoacrylate, diethylene glycol monovinyl ether, 2-hydroxyethyl vinyl ether, and allyl alcohol. These graft components may be used alone or in combination of two or more.

The hydroxyl group-modified polypropylene resin used in the present invention is obtained by melt-kneading an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group, a propylene resin and an organic peroxide. Is obtained. The amount of the organic compound having at least one unsaturated bond and having a hydroxyl group in the molecule in the hydroxyl group-modified polypropylene resin is 0.01 to 10% by weight, preferably 0.1 to 10% by weight.
Is. Here, if the amount of the organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group is less than 0.01% by weight, the effect of improving surface workability and impact resistance is poor, which is not preferable. If it exceeds%, the mechanical strength decreases, which is not preferable.

Ethylene and α-used in the present invention
As the copolymer with olefin, those obtained by copolymerizing ethylene with various α-olefins can be used. α
-Examples of olefins include propylene and butene-
1,4-methylpentene-1, hexene-1 and the like can be mentioned, and among them, a copolymer of propylene and ethylene is most easily available and is preferable.

Ethylene-α-used in the present invention
Examples of the unsaturated carboxylic acid contained in the olefin copolymer include maleic anhydride, itaconic anhydride, citraconic anhydride, fumaric anhydride, endic acid anhydride, and a double bond at the terminal having at most 18 carbon atoms. Examples thereof include alkenyl succinic anhydride, and alkadienyl succinic anhydride having a double bond at the terminal having at most 18 carbon atoms. The amount of the unsaturated dicarboxylic acid anhydride contained in the ethylene-based copolymer is 0.01 to 10% by weight, and when the amount of the unsaturated dicarboxylic acid is less than 0.01% by weight, impact resistance is low. Unfavorable because of poor improvement effect 1
When it exceeds 0% by weight, moldability is deteriorated, which is not preferable.

In the present invention, the ratio of (a) polypropylene resin to (b) hydroxyl group-modified polypropylene resin is (b) 10 to 1 with respect to (a) 100 parts by weight.
00 parts by weight is preferred. If it is less than 10 parts by weight, the effect of improving the surface workability and impact resistance is poor, which is not preferable. 1
If it exceeds 100 parts by weight, mechanical strength is lowered, which is not preferable.

In the present invention, the ratio of (c) a copolymer of ethylene and α-olefin and (d) a copolymer of ethylene and α-olefin graft-modified with an unsaturated carboxylic acid is (c) 100. (D) 100 to 3 with respect to parts by weight
00 parts by weight is preferred. If it is less than 100 parts by weight, the effect of improving the impact resistance is poor, so that it is not preferable, and if it exceeds 300 parts by weight, the formability is remarkably deteriorated, which is not preferable.

The ethylene-α-olefin copolymer graft-modified with the unsaturated carboxylic acid used in the present invention is
It is obtained by melt-kneading an ethylene-α-olefin copolymer, an unsaturated carboxylic acid, and an organic peroxide.

The composition of the present invention comprises (a) a polypropylene resin, and (b) 0.01% of an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group.
Hydroxyl group-modified polypropylene resin graft-modified with 10 to 10 wt% polypropylene resin, (c) 0.01 to 10 wt% graft-modified ethylene and α-olefin copolymer, and (d) unsaturated carboxylic acid Is a resin composition containing a copolymer of ethylene and α-olefin, and (a) and (b) are 50 to 99% by weight, preferably 60 to 90% by weight, and (c) and (d) ) 5
It is preferable to melt-knead 0 to 1% by weight, preferably 40 to 10% by weight. If (a) and (b) is less than 50% by weight, the rigidity is lowered, which is not preferable, and if it exceeds 99% by weight, the effect of improving the surface workability and impact resistance is poor, which is not preferable. Further, when (c) and (d) are less than 1% by weight, the effect of improving surface workability and impact resistance is poor, which is not preferable, and when more than 50% by weight, rigidity is lowered, which is not preferable.

In the present invention, (a) a polypropylene resin, and (b) 0.01% of an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group.
Hydroxyl group-modified polypropylene resin graft-modified with 10 to 10 wt% polypropylene resin, (c) 0.01 to 10 wt% graft-modified ethylene and α-olefin copolymer, and (d) unsaturated carboxylic acid (5) Add 0.01 to 5 parts by weight, preferably 0.05 to 0.3 parts by weight of a reaction accelerator to 100 parts by weight of the copolymer of ethylene and α-olefin and melt-knead. However, it is preferable since it improves impact resistance. (E) If the amount of the reaction accelerator is less than 0.01 parts by weight, the effect of improving the impact resistance is small, and if it exceeds 5 parts by weight, the mechanical strength decreases, which is not preferable.

In the present invention, the (e) reaction accelerator is a compound that promotes the reaction between a hydroxyl group and a carboxyl group, preferably a metal salt compound, and more preferably an alkali metal salt compound. Preferable examples include alkali metal salts of carboxylic acids such as acetic acid, benzoic acid, oleic acid and stearic acid, and alkali metal salts of carbonic acid such as potassium carbonate and sodium hydrogen carbonate.

Various kinds of resins can be mixed with the resin composition of the present invention, and fillers such as talc and glass fiber can also be mixed and used. Further, if necessary, additives such as stabilizers, flame retardants, processability improvers, lubricants, antistatic agents, ultraviolet absorbers, colorants, pigments and foaming agents can be added. The method for producing the polypropylene resin composition according to the present invention is not particularly limited, and a usual kneading machine for plastics such as a Banbury mixer or a screw type extruder can be used.

A molded product obtained from the polypropylene resin composition according to the present invention can be painted, printed, bonded and the like and has good mechanical properties such as impact resistance and heat resistance, so that a bumper or instrument panel. Auto parts such as
A wide range of applications can be expected for electronic and electrical equipment parts.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0021]

【Example】

(A) Polypropylene resin (A-1) A propylene homopolymer having a density of 0.906 g / cm ³ and a melt flow rate (230 ° C., 2.16 kg) of 24 g / 10 minutes.

(B) Hydroxyl group-modified polypropylene resin (b-1 to 3) A propylene homopolymer having a density of 0.906 g / cm ³ and a melt flow rate (230 ° C., 2.16 kg) of 0.6 g / 10 minutes. 1,3-bis- (t-butylperoxy-isopropyl) -benzene 0.1, 0.4, 3.0 parts by weight per 100 parts by weight, and the graft comonomers 1, 3, 30 shown in Table 1. Parts obtained by blending parts by weight and melt-kneading were used.

(C) Copolymer of ethylene and α-olefin (C-1) Ethylene-propylene copolymer having a propylene content of 22% by weight and a melt flow rate (230 ° C., 2.16 kg) of 8.6 g / 10 minutes. Polymer.

(D) Copolymer of ethylene and α-olefin graft-modified with unsaturated carboxylic acid (d-1 to 3) Propylene content 22% by weight, melt flow rate (230 ° C, 2.16 kg) 8. 0.1, 0.4, 3.0 parts by weight of 1,3-bis- (t-butylperoxy-isopropyl) -benzene, and 100 parts by weight of an ethylene-propylene copolymer of 6 g / 10 minutes, and Those obtained by blending the graft comonomers shown in Table 2 and melt-kneading were used.

(E) Reaction accelerator (E-1) Sodium stearate was used.

(Examples 1 to 6) (Comparative Examples 1 to 15) Using a 40 mm same-direction twin-screw extruder manufactured by Pla Koken Co., Ltd., Table 3,
The composition described in 4 was kneaded under the conditions of a set temperature (die exit) of 230 ° C. and an extrusion rate of 16 kg / h to obtain various pellet-shaped composition samples. Test pieces were prepared from these various composition samples by the method described below, and the results of tests on paintability, heat resistance, impact resistance, and rigidity are shown in Tables 3 and 4.
It was shown to.

(Paintability test) A polypropylene resin composition was injection-molded at a set temperature of 210 ° C. to obtain a length of 300 m.
A plate-like test piece having m, a width of 130 mm and a thickness of 3 mm was obtained.
This plate-shaped test piece is washed with water, dried at room temperature, sprayed with a primer (RB150-2, manufactured by Nippon Bee Chemical Co., Ltd.), and then a urethane-based paint (R-212, R-213, manufactured by Nippon Bee Chemical Co., Ltd.) is applied. Spray painting, 12
The baking finish was performed for 45 minutes in an oven at 0 ° C. The center of the obtained coating test piece is 70 mm long and 25 width wide.
What was cut into mm was immersed in gasohol (gasoline: ethanol = 9: 1), and the time until the coating film peeled off was measured.

(Heat resistance test) A polypropylene resin composition was injection molded at a set temperature of 210 ° C., and a length of 127 m.
A test piece having m, a width of 112.7 mm and a thickness of 6.4 mm was prepared. This test piece is designated ASTM D648 (66
The HDT value was measured according to PSi).

(Impact resistance test) A polypropylene resin composition was injection-molded at a set temperature of 210 ° C. to obtain a length of 63 m.
A test piece having m, a width of 12.7 mm and a thickness of 3.18 mm was prepared. Make a notch in this test piece and
The Izod impact value was measured according to D256-56.

(Stiffness test) A polypropylene resin composition was injection-molded at a set temperature of 210 ° C., and a length of 127 mm,
A test piece having a width of 112.7 mm and a thickness of 6.4 mm was prepared. The flexural modulus of this test piece was measured according to ASTM D790.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

EFFECTS OF THE INVENTION According to the present invention, a molded article of a polypropylene resin composition having not only excellent surface workability but also excellent heat resistance and impact resistance can be obtained.

Claims (2)

[Claims] 1. A polypropylene resin (a), and (b) an organic compound having at least one unsaturated bond in a molecule and having a hydroxyl group, is graft-modified with 0.01 to 10% by weight of a polypropylene resin. Hydroxyl group-modified polypropylene-based resin, (C) ethylene-α-olefin copolymer, and (D) 0.01-10% by weight of unsaturated carboxylic acid graft-modified ethylene and α-
A resin composition containing a copolymer with an olefin, comprising: (a) a polypropylene resin and (b) an organic compound having at least one unsaturated bond in a molecule and containing a hydroxyl group of 0.01 to 50% to 99% by weight of a hydroxyl group-modified polypropylene resin graft-modified with 10% by weight of a polypropylene resin, (C) a copolymer of ethylene and α-olefin and (D) an unsaturated carboxylic acid of 0.01 to A polypropylene resin composition, characterized in that 50 to 1% by weight of a copolymer of ethylene and α-olefin graft-modified with 10% by weight is melt-kneaded. 2. A polypropylene-based resin (a), and (b) an organic compound having at least one unsaturated bond in a molecule and having a hydroxyl group is graft-modified with 0.01 to 10% by weight of a polypropylene-based resin. Hydroxyl group-modified polypropylene-based resin, (C) ethylene-α-olefin copolymer, and (D) 0.01-10% by weight of unsaturated carboxylic acid graft-modified ethylene and α-
2. The polypropylene according to claim 1, wherein 0.01 to 5 parts by weight of (e) reaction accelerator is added to 100 parts by weight of a resin composition containing a copolymer with an olefin and melt-kneaded. -Based resin composition.