JPH01301738A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain a polypropylene resin composition having excellent coating film adhesivity and impact strength, by compounding a crosslinked and modified material consisting of a specific copolymer and an ethylene-alpha-olefin rubber with a polyolefin rubber modified with an unsaturated carboxylic acid. CONSTITUTION:The objective resin composition is produced by compounding (A) 50-90pts.wt. of a polypropylene with (B) 10-50pts.wt. of a modified material produced by crosslinking a resin composition consisting of B1 40-95wt.% of an ethylene/alpha,beta-ethylenic unsaturated carboxylic acid copolymer containing >=5wt.% of alpha,beta-ethylenic unsaturated carboxylic acid and B2 60-5wt.% of an etylene-alpha-olefin copolymer rubber with 60-5,000ppm of an organic peroxide (having a half-life of 1min at >=100 deg.C) and compounding the resin mixture with (C) 0.5-15pts.wt. (based on 100pts.wt. of A+B) of a modified polyolefin rubber added with 0.05-5wt.% of an unsaturated carboxylic acid (derivative).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel polypropylene resin composition. More specifically, the present invention is particularly suitable as a coating material, which allows topcoating without undercoating the brimer, has extremely good film adhesion of the topcoat, and has high impact resistance. The present invention relates to a polypropylene resin composition that can give molded articles.

[Prior Art] Conventionally, polypropylene resin has been known to be chemically inert because it does not have a polar group in its molecule and has extremely poor paintability.Therefore, market needs have particularly increased in recent years. For painted bumpers made of polypropylene resin, a method is used in which a primer is applied as an undercoat and then a polyurethane paint is applied thereon to improve the adhesion of the topcoat paint.

However, this method has problems such as an increase in the number of steps and a long time required to finish the product, as well as high paint costs. is being done.

Conventional techniques that can be applied to primerless coating of polypropylene resin bumpers include, for example, (]-) plasma treatment methods (JP-A-57-207625, JP-A-58-208337-208339, JP-A No. 58-208337-208339, JP-A No. 58-208337-208339, JP-A-58-208337-208339;
]-09530), (2) a method of grafting a polar group onto polypropylene (JP-A-62-64848, JP-A No. 62-119243), (3) a method of blending a polar substance into polypropylene (JP-A No. 62-64848, JP-A No. 62-119243). Showa 51-145
No. 553, No. 61-89239), etc. have been proposed.

However, although the method (1) using plasma treatment can provide high coating film adhesion, it has high equipment costs, poor process flow, and the plasma treatment may not be uniform. It has disadvantages, and (2
In the method of grafting polar groups onto polypropylene (), the monomers used may be toxic, sufficient coating film adhesion may not be obtained, and the weather resistance and other physical properties of the composition may deteriorate. There are some problems that cannot be avoided.

Furthermore, as for the method (3) of blending a polar substance with polypropylene, for example, a partially crosslinked mixture of polypropylene resin kneaded with ethylene copolymer rubber and an ethylene-acrylic acid ester copolymer is blended. A composition comprising a polyolefin and an unsaturated dicarboxylic acid-modified polymer (Japanese Unexamined Patent Publication No. 61-89239) has been disclosed. However, all of these compositions do not necessarily have sufficient coating film adhesion as bumper materials for primerless painting, and have not yet been put to practical use.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of the prior art related to primerless painting of polypropylene resin bumpers, allows for topcoating without undercoating the brimer, and also enables the use of a topcoat paint. This polypropylene resin composition has a high impact strength and is suitable for various polypropylene coatings, including polypropylene bumper materials for painting. It was made with the purpose of providing.

[Means for Solving the Problems] The present inventors first added specific α-, β-
Ethylene-α with ethylenically unsaturated carboxylic acid units
discovered that a scale made by blending a β-ethylenically unsaturated carboxylic acid copolymer and a polyolefin rubber modified with an unsaturated carboxylic acid or its derivative in a specific ratio is suitable for the purpose. .

However, although these compositions have sufficiently high adhesion to urethane coatings, they must have high impact resistance in order to be used as bumper materials.

Therefore, as a result of intensive research, the present inventors found that a specific α
, a β-ethylenically unsaturated carboxylic acid copolymer and an ethylene-α-olefin copolymer rubber are cross-linked with an organic peroxide, and this modified product is made into a polyolefin modified with polypropylene and an unsaturated carboxylic acid or its derivative. It was discovered that a polypropylene composition with high adhesion of a urethane coating film and high impact strength could be obtained by blending it with a polypropylene rubber, and based on this investigation, the present invention was completed.

That is, the present invention provides (A) polypropylene 50 to 90
parts by weight and (B) ethylene units and at least one α
, a copolymer with β-ethylenically unsaturated carboxylic acid units, comprising 5 α,β-ethylenically unsaturated carboxylic acid units.
10-50% by weight of a modified resin composition made of 40-95% by weight of a copolymer containing 40-95% by weight or more and 60-5% by weight of ethylene-α-olefin copolymer rubber, crosslinked with 60ppm or more of an organic peroxide. Component (A) and (B)
) to the total amount of 100 parts by weight of (C)
The present invention provides a polypropylene resin composition characterized in that it contains 0.5 to 15 parts by weight of a modified polyolefin rubber modified with an unsaturated carboxylic acid and/or a derivative thereof.

The present invention will be explained in detail below.

The polypropylene used as component (A) in the composition of the present invention includes, for example, a copolymer part consisting of an isotactic propylene homopolymer having crystallinity or an ethylene propylene lantum copolymer having a low content of ethylene units. or a homopolymer made of a propylene homopolymer and a copolymer part made of an ethylene propylene lantam copolymer with a relatively high content of ethylene units, which is substantially commercially available as a so-called propylene block copolymer. copolymer of crystalline propylene and ethylene,
Alternatively, a substantially crystalline propylene-ethylene-α-olefin copolymer, in which each homo portion or copolymer portion in this block copolymer is further copolymerized with a monoolefin such as butene-1, is preferably mentioned. It will be done.

Among these polypropylenes, M1100 or less g/
10 minutes, particularly 1 to 509/10 minutes, is suitable.

The blending ratio of polypropylene used as component (A) in the composition of the present invention is such that the total amount of polypropylene used as component (B) is 100%
In terms of parts by weight, it is 50 to 90 parts by weight. Moreover, if it is less than 50 parts by weight, the physical properties such as rigidity will deteriorate and it cannot be used as a bumper material. If it exceeds 90 parts by weight, high adhesiveness cannot be obtained.

In the composition of the present invention, a copolymer of ethylene and α,β-ethylenically unsaturated carboxylic acid is used as a part of component (B). Examples of the σ,β-ethylenically unsaturated carboxylic acids include those having 3 to 8 carbon atoms, such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, chromic acid, isocrotonic acid, maleic acid, and fumaric acid. is preferably used.

One type of these α,β-ethylenically unsaturated carboxylic acids may be used, or two or more types may be used in combination.

The content of σ, β-ethylenically unsaturated carboxylic acid units in this copolymer is 5% by weight or more, preferably 7 to 40% by weight.
It is necessary that it be in weight%. If the content is less than 5% by weight, high coating film adhesion cannot be obtained even if the amount added to the polypropylene component is increased.

Further, even if a copolymer of ethylene and an ethylenically unsaturated carboxylic acid ester, such as an ethylene-vinyl acetate copolymer, is used instead of this copolymer, high coating film adhesion cannot be obtained.

There are no particular restrictions on the method for producing this ethylene-α,β-ethylenically unsaturated carboxylic acid copolymer, and known methods (Japanese Patent Publication No. 38-234.94, Japanese Patent Publication No. 45-2
No. 0111). As commercially available products, those from Tau Chemical Co., Ltd. and DuPont Mitsui Chemical Co., Ltd. can be used, but preferred ones have an Ml of 1 to 500 g/10 min, particularly 5 to 400 g/1 min.
It is 0 minutes.

Examples of the ethylene-a-olefin copolymer rubber used in the present invention include propylene homopolymers, block copolymers and random copolymers of propylene and a copolymer component such as ethylene.

In the case of an ethylene-propylene copolymer, the content of ethylene units is preferably in the range of 10 to 80% by weight; if this content is less than 10% by weight, the impact resistance will be poor, and if it exceeds 80% by weight, the rigidity will be poor. descend.

This ethylene-propylene copolymer is
Contains P and ethylene-propylene rubber (EP rubber). Furthermore, EP rubbers include ethylene-propylene rubber, ethylene-propylene-nonconjugated diene copolymer (EPDM), and the like.

Furthermore, a copolymer of ethylene, propylene, and an α-olefin having 4 or more carbon atoms can also be used;
Examples of the above-mentioned olefins include butene-1, pentene-1,4-methylhexene-1,
These have the effect of imparting viscosity.

In the components (B) of the composition of the present invention, the ratio of the copolymer consisting of ethylene units and α,β-ethylenically unsaturated carboxylic acid units to the ethylene-α-olefin copolymer rubber is 40 to 95% by weight of the former. %, preferably 95% by weight, the impact strength decreases.

Furthermore, the organic peroxide used in the present invention is generally used as an initiator in radical polymerization and a crosslinking agent for polymers, and preferably has a half-life of 1 minute or more at 100°C. especially 130°C
The above are preferred.

If the temperature is below 100° C., it is not only difficult to handle, but also the effect of using it is not very noticeable, so it is not desirable. Representative examples of preferred organic peroxides include 1,1-his-tertiary-butylperoxy-
Ketone peroxides such as 3,3,5-)limethylcyclohexane, dialkyl peroxides such as diacyl peroxide, hydroperoxides such as 2,5-dinorhexane-2,5-no
Mention may be made of diacyl peroxides such as benzoyl peroxide and peroxy esters such as 2,5-dimethyl-2,5-dibenzoyl peroquine hexane.

In the present invention, the amount of organic peroxide used can be appropriately selected depending on the required properties, and can be used in an amount of about 60 to 5000 ppm. If the amount is less than 60 ppm, the crosslinking reaction will not be sufficient and high adhesiveness will not be obtained as a composition. 5
If it exceeds 000ppm, the degree of crosslinking will be too thick, the appearance will be poor,
Toughness may also decrease.

The crosslinking reaction can be carried out under appropriate conditions by selecting the temperature and time depending on the decomposition temperature of the peroxide used.

The amount of component (B) used in the composition of the present invention is as follows: (A) and (B)
The amount is 10 to 50 parts by weight, preferably 15 to 45 parts by weight, based on the total amount of 100 parts by weight. This usage amount is 10
If the amount is less than 50 parts by weight, the adhesiveness will decrease, and if it exceeds 50 parts by weight, the rigidity etc. will decrease, making it impossible to use it for bumpers.

In addition, the modified polyolefin rubber modified with unsaturated carboxylic acid and/or its derivative is the above-mentioned ethylene-α-olefin-based rubber.
A material similar to copolymer rubber can be used.

Examples of unsaturated carboxylic acids used for modification include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, -crotonic acid, citraconic acid, sorbic acid,
Examples include mesaconic acid and angelic acid, and their derivatives include acid anhydrides, esters, amidimides, and metal salts, such as maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, and methyl methacrylate. , ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, maleic acid monoamide, maleimide, N-butylmaleimide, sodium acrylate, sodium methacrylate, and the like.

These unsaturated carboxylic acids and their derivatives may be used alone when modifying the polyolefin rubber, or
Two or more types may be used in combination, and there are no particular restrictions on the modification method, and various known methods can be used. For example, the polyolefin rubber may be dissolved in a suitable organic solvent, unsaturated carboxylic acids, derivatives thereof, and radical generators may be added thereto, followed by stirring and heating, or the above-mentioned components may be fed into an extruder to carry out graft copolymerization. You can use the method described above.

The modified polyolefin rubber used as component (C) in the composition of the present invention has an added amount of unsaturated carboxylic acid and/or its derivative from 0.05 to 5 wL%, particularly 0.3 wL%.
-2 wt%, MI or 0.05-4 g/10 min, especially 0.
1 to 2 g/10 min is preferable, and it may also be a polyolefin rubber modified as described above or a mixture of this and an unmodified polyolefin rubber.

In the composition of the present invention, the modified polyolefin rubber as component (C) is 0.5 to 15 parts by weight, preferably 2 to 15 parts by weight, based on 100 parts by weight of the total amount of components (A) and CB). It is blended in a proportion of 10 parts by weight, more preferably 2 to 8 parts by weight. If the blending amount is outside this range, high coating film adhesion cannot be obtained, making it unsuitable as a bumper material.

A binary system of polypropylene and the modified polyolefin rubber cannot provide high coating film adhesion, and a binary system of polypropylene and ethylene-σ,β-ethylenically unsaturated carbon which does not contain this modified polyolefin rubber Even in a binary system of a crosslinked modified product of an acid copolymer and an ethylene-α-olefin rubber, high coating film adhesion cannot be obtained.

The composition of the present invention may contain various additives, reinforcing materials,
Fillers, such as heat stabilizers, weather stabilizers, antistatic agents,
A lubricant, a slip agent, a nucleating agent, a flame retardant, a pigment, a dye, a glass fiber, a carbon fiber, a calcium rehydrate, a calcium sulfate, etc. can be added within a range that does not impair the object of the present invention.

There are no particular restrictions on the method for producing the composition of the present invention, and methods conventionally used for producing polypropylene resin compositions can be used.
) The order of mixing the components can be freely selected as desired. For example, the required amounts of the above (A) components, (B) components, (C) components and various additive components used as necessary may be mixed in a kneader such as a kneader, roll, or Hanbali mixer, or in a single-screw or two-shaft kneader. The selection can be made by kneading using a screw press or the like.

In addition, production of a masterbatch of component (B) and (A,)
In kneading components (B) and (C), a kneader having two or more sample input ports and a sufficiently long residence time can be used to produce the product in a - step using a kneader with two kneaders. You can also do it.

That is, a triblend of ethylene-α, β-ethylenically unsaturated carboxylic acid copolymer, ethylene-σ-olefin rubber, and organic peroxide was charged from the first input port,
After a sufficient crosslinking reaction has occurred, a triblend of polypropylene and a modified polyolefin rubber modified with an unsaturated carboxylic acid is charged from the second inlet.

This method is very useful in that the original composition can be obtained by kneading twice without creating a master hatch.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, the abbreviations in the table mean the following contents.

-15= PP-teethylene-propylene copolymer, manufactured by Idemitsu Petrochemical Co., Ltd., trade name J-765H.

MI 8.29/10 minutes (230°C), ethylene unit content: ii: 8.3 wt% PP-2: Ethylene-propylene copolymer manufactured by Idemitsu Petrochemical Co., Ltd., trade name J-4,65H.

Ml 2.29/10 min (230°C) Ethylene unit content 10.9 wt% PP-3: Homopropylene manufactured by Idemitsu Petrochemical Co., Ltd., product name J-700G MI 8.59/10 min (230°C) EAA-1:
Ethylene-acrylic acid copolymer, manufactured by DuPont Mitsui Polychemical Co., Ltd., trade name Nucrel N1560, MT 60 g/10 minutes (190°C), acrylic acid unit content 15 wt% EAA-2: Ethylene-acrylic acid copolymer , manufactured by Dow Chemical Co., Ltd., trade name Primacol X0-2375.33, MT 3
009/10 min (19000), acrylic acid unit content 2
0w [% EPR-1: Ethylene-propylene rubber Mitsui Petrochemical (
Co., Ltd., trade name: Tafmer S-5-4O 300, 45 g, 710 minutes Propylene content: 73 wt% EPR-2: Ethylene-propylene rubber Japan Synthetic Rubber (
Co., Ltd., product name: EP07PMI O, 6y/lo (
230°C) Propylene content 27wt% POD-1: Organic peroxide agent manufactured by Nouri Co., Ltd., trade name Bariki Dox 14 1.3-His-(t-butylperoxyingropyl)-benzene halved in 1 minute Period: 183°C POD-2: Organic peroxide agent manufactured by Nouri Co., Ltd., trade name Kayahexa AD 2,5-dimethyl-2,5-di(t-butylperoxy)-hexane 1 minute half-life: 181° C EP-MAH-1: Modified polyolefin rubber, manufactured by Sumima Kagaku Co., Ltd., trade name M-12OS MI o, sg/io (230°C), maleic anhydride addition Ji1. Ow1% EP-MAR-2: Modified polyolefin rubber, manufactured by Japan Synthetic Rubber Co., Ltd., trade name T7774. IP.

Ml 0.6 g/l, 0 minutes (230°C), maleic anhydride addition amount 0.5 wt% Examples 1 to 22 and Comparative Example 1 Ethylene-α, β-ethylenically unsaturated carboxylic acid copolymer and ethylene - After dry pretenting α-olefin rubber and organic peroxide in the proportions shown in Table 1, this is used in a kneader to completely decompose the organic peroxide. A masterbatch (B) component was prepared by carrying out a crosslinking reaction. Furthermore, components (A), (B) and (C) were tri-blended in the proportions shown in Table 1, and further kneaded.

Comparative Examples 2 to 7 The components shown in Table 2 were triblended at the indicated mixing ratios and kneaded to produce compositions.

The compositions obtained in the above Examples and Comparative Examples were injection molded to create molded products measuring 140 x 140 x 3 mm.

1.1.1. -1 with trichloroethane vapor
After steaming for a minute and degreasing, it was left to cool for several tens of minutes.

Next, spray paint urethane paint directly on this molded product without applying a brimer, and then apply a 90°
It was baked at C for 45 minutes and dried. The adhesion of the urethane coating on the painted molded product was determined by making a 10 mm wide incision in the coating and cutting it using Autograph DSC2 manufactured by Shimadzu Corporation.
000, and the 180° peel strength was measured.

The pulling speed was 50 mm and 1 minute in both cases. The results are shown in Table 1 and Table 2.

As the urethane paint, Nippon B Chemical Co., Ltd.'s product name R-273 (main agent) and product name R-271 (curing agent) were mixed at a weight ratio of 5:1, and nonner was added to adjust the viscosity. I used the one I made.

In addition, the impact strength is based on JIS K-7110,
A hatched Izont impact test was conducted at 23°C.

(The following is a blank space) [Effects of the Invention] The polypropylene resin composition of the present invention can be overcoated without undercoating with a primer, and can provide a molded article with significantly improved coating film adhesion of the topcoat. Various polypropylene coating materials are suitably used as materials, including polypropylene bumper materials for coating.

Patent applicant: Idemitsu Petrochemical Co., Ltd. Representative Patent Attorney Kubo 1) Fujibe

Claims (1)

[Claims] 1 (A) 50 to 90 parts by weight of polypropylene and (B)
A copolymer of ethylene units and at least one α,β-ethylenically unsaturated carboxylic acid unit, which contains 5% by weight or more of α,β-ethylenically unsaturated carboxylic acid units 40- 60% by weight of a resin composition consisting of 95% by weight and 60-5% by weight of ethylene-α-olefin copolymer rubber.
Modified product crosslinked with ppm or more of organic peroxide 10 to 50
parts by weight to make the total amount of components (A) and (B) 100 parts by weight, and (C) 0.5 parts by weight of a modified polyolefin rubber modified with an unsaturated carboxylic acid and/or a derivative thereof. A polypropylene resin composition characterized in that it contains ~15 parts by weight.