JP3342989B2 - Propylene resin composition for coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel propylene-based resin composition for coating having excellent paintability, adhesiveness and printability, and more particularly, to excellent low-temperature paintability, adhesiveness and the like. The present invention relates to a propylene-based resin composition for coating that has printability, maintains a high mechanical strength balance (rigidity, impact strength), and good moldability, and is suitable as a material for various industrial parts.

[0002]

2. Description of the Related Art Hitherto, propylene-based resin materials for various industrial parts are often put to practical use after being entirely or partially painted. However, since these propylene-based resin materials do not have a polar group in the structure of the material itself, it has been difficult to obtain a practical level of paint adhesion strength when directly applying a paint. Therefore, in many cases, such a propylene-based resin material improves the paint adhesion performance by preliminarily applying TCE (trichloroethane) degreasing to the surface of the preformed material, applying a primer, or performing a plasma treatment. I was letting it.

[0003]

However, such a coating method has conventionally had the following problems. First, the use of TCE (trichloroethane) degreasing treatment has been banned since 1995 by the Montreal Protocol in order to protect the global environment. In addition, the primer coating method has the disadvantage that the expensive primer must be used and the number of coating steps increases, which increases the coating cost.In addition, the solvent in the primer is volatilized. Because of the necessity of fire, there was a risk of fire and safety problems.

On the other hand, in the plasma processing method, a high vacuum state is required, so that expensive equipment must be installed, and the cost cannot be avoided because of the batch system. . Furthermore, recently, a molded article having a complicated shape has been required. However, it is difficult to perform a uniform plasma treatment on the molded article having such a complicated shape. To decrease
In some cases, the coating performance varied, and handling was extremely inconvenient. Therefore, if the steps of TCE (trichloroethane) degreasing, primer coating, and plasma treatment in the coating of a molded article made of a propylene-based resin can be omitted, the coating process can be simplified, the working environment can be improved, and the cost can be reduced. Therefore, many studies have been made to omit these steps.

For example, a resin composition containing a hydroxyl-modified polypropylene (Japanese Patent Publication No. 5-64660), a resin composition containing an unsaturated carboxylic acid-grafted polypropylene (Japanese Patent Application Laid-Open No. 5-59231), an ethylene-based elastomer, A resin composition containing polypropylene to which a charging agent has been added (Japanese Patent Application Laid-Open No. 6-9835) has been proposed. However, molded articles of these compositions do not always have sufficient paint adhesion strength when the paint is applied directly, and are particularly practical when a high mechanical strength balance is required, especially when high rigidity and impact strength are simultaneously required. In order to obtain a level of paint adhesion strength, either TCE (trichloroethane) degreasing treatment or primer coating treatment was practically necessary.

[0006] Further, the paint adhesion strength when the paint of a molded article of these compositions is directly applied is remarkably reduced depending on the kind of the paint, and particularly in the case of a melamine-based paint, the tendency is strong. It has been difficult to achieve a good balance between adhesion strength, high mechanical strength balance (high rigidity and low-temperature impact resistance), and good moldability. Therefore, the present inventors have previously proposed a propylene-based resin composition containing a specific elastomer component and a modified propylene polymer together with a filler (see Japanese Patent Application No. 6-178944), and have a relatively low paint baking temperature. Despite the use of melamine-based paints, which are difficult to obtain at 140 ° C. and which usually have high paint adhesion strength, they succeeded in developing a practical level of paint adhesion strength with a high balance between physical properties and workability.

However, recently, from the viewpoint of energy saving and cost reduction, further lowering of the paint baking temperature and shortening of the baking time have been demanded.
Sufficient paint adhesion strength is required under baking conditions of about 15 minutes. On the other hand, in the molded articles such as the above-mentioned various compositions, when a paint (particularly, a melamine-based paint) is directly applied, a baking at 130 ° C. (15 minutes) can provide a practical level of paint adhesion strength. It was difficult.

[0008]

[Means for Solving the Problems]

[Summary of the Invention] The present inventors have conducted intensive studies in order to achieve such objects as simplification of such a coating process and realization of practical paint adhesion strength even at a low paint baking temperature. Despite the fact that a molded article molded using a specific propylene-based resin composition is directly applied with a paint and baked at 130 ° C. for 15 minutes, it has practically sufficient paint adhesion strength and high mechanical strength. The inventors have found that they have strength balance and moldability, and have completed the present invention.

That is, the propylene resin composition for coating of the present invention is characterized by comprising the following components (a) to (f). Component (a): a propylene / ethylene block copolymer containing a crystalline polypropylene portion (A unit) and an ethylene / propylene random copolymer portion (B unit): 100 parts by weight Component (b): butene- Ethylene / butene-1 copolymer rubber having a content of 25 to 40% by weight, a density of 0.87 g / cm ³ or less and a melt flow rate (230 ° C., 2.16 kg) of 10 g / 10 minutes or less: 10 -80 parts by weight Ingredient (c): talc having a substantially whole length of 15 µm or less, an average particle size of 1.5 to 6 µm and an average aspect ratio of 5 or more, an average particle size of 8 to 100 µm, and Mica having an average aspect ratio of 10 or more, or at least one filler selected from fibrous fillers having an average diameter of 6 μm or less and an average aspect ratio of 5 or more: 5 to 80 parts by weight Component (d) A modified propylene homopolymer or a modified propylene homopolymer obtained by grafting maleic anhydride or a maleic anhydride derivative having a hydroxyl group represented by the following chemical formula to a propylene-based polymer at a ratio of 3 to 25% by weight of the whole component (d). Or random copolymer of ethylene and ethylene: 5 to 40 parts by weight

[0010]

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(Wherein R represents an alkylene group having 1 to 4 carbon atoms.) Component (e): Phosphorus oxyacid compound: 0.05 to 4 parts by weight Component (f): Diene polymer having a hydroxyl group at a terminal Or its hydrogenated product: 0 to 10 parts by weight

[I] Propylene resin composition (1) Constituent component composition (a) Component (a): propylene / ethylene block copolymer Propylene resin composition for coating of the present invention The propylene / ethylene block copolymer of component (a) constituting
A propylene / ethylene block copolymer containing a crystalline polypropylene part (A unit part) and an ethylene / propylene random copolymer part (B unit part),
The unit is obtained by homopolymerization of propylene, and the B unit is obtained by random copolymerization of propylene and ethylene. Where A
The unit part is preferably 60 to 95% by weight in the propylene / ethylene block copolymer in terms of heat resistance and rigidity.
More preferably, it occupies 75 to 94% by weight, and its density is also 0.1% in terms of heat resistance rigidity.
9070 g / cm ³ or more, preferably 0.9086 g / cm ³
More preferably, it is not less than cm ³ . In addition, the B unit portion accounts for preferably 5 to 40% by weight, more preferably 6 to 25% by weight in the propylene / ethylene block copolymer, particularly in view of paint adhesion and impact resistance. The ethylene content is preferably 20 to 80% by weight, more preferably 25 to 50% by weight, in terms of paint adhesion and impact resistance.

The melt flow rate (hereinafter simply referred to as “MFR”) of the whole propylene / ethylene block copolymer is 5 to 100 g / 10 min, particularly 10 to 50 g / min.
10 minutes is preferable, and the weight average molecular weight / number average molecular weight (Mw / Mn) of the entire propylene / ethylene block copolymer is 7 in terms of moldability and appearance of the molded article.
Above, especially those with 8 or more are preferred. Incidentally, the content of the B unit part of the propylene / ethylene block copolymer is 2
g sample was immersed in 300 g of boiling xylene for 20 minutes to dissolve, cooled to room temperature, and the precipitated solid phase was filtered through a glass filter and dried to obtain the value calculated from the solid phase weight calculated from the solid phase weight. is there. In addition, the weight average molecular weight /
The value of the number average molecular weight (Mw / Mn) was measured by gel permeation chromatography (GPC), the value of the ethylene content was measured by infrared spectrum analysis or the like, and the value of the MFR was JIS-K7210 (230).
C., 2.16 kg).

[0014] Manufacturing Such propylene-ethylene block copolymer of component (a), slurry polymerization, gas phase polymerization using a highly stereoregular polymerization catalyst, or those produced by liquid-phase bulk polymerization In addition, as a polymerization system for producing the propylene / ethylene block copolymer, either a batch polymerization system or a continuous polymerization system can be adopted. When producing this propylene / ethylene block copolymer, either part may be polymerized first, but first, a crystalline polypropylene part (A unit part) is formed by homopolymerization of propylene, and then What formed the ethylene-propylene random copolymer part (B unit part) by the random copolymerization of propylene and ethylene is preferable from a quality viewpoint. As a specific method, propylene homopolymerization is performed using a catalyst in which an organic aluminum compound component is combined with a solid component formed by contacting magnesium tetrachloride, titanium tetrachloride, an organic acid halide and an organic silicon compound, Then, it can be produced by performing random copolymerization of propylene and ethylene. The propylene / ethylene block copolymer may contain other unsaturated compounds, for example, α-olefins such as butene-1 and vinyl esters such as vinyl acetate, within the range not impairing the effects of the present invention. The copolymer may be an original copolymer or a mixture thereof.

[0015] Each component of the components to be blended into the paint propylene resin composition of the proportion present invention (a) ~ component (f) is a propylene-ethylene block copolymer 100 parts by weight of the component (a) Is blended on the basis of The mixing ratio of each component below the component (b) is as described below.

(B) Component (b): Ethylene / butene-1 copolymer rubber component (EBM) Ethylene / butene-12 of the above-mentioned component (b) constituting the coating propylene resin composition of the present invention. The original copolymer rubber component has a butene-1 content of 25 to 40% by weight, preferably 30 to 40% by weight.
To 40% by weight, particularly preferably 30 to 36% by weight, and a density of 0.87 g / cm ³ or less, preferably 0.84 to 0.8%.
7 g / cm ³ , particularly preferably 0.85 to 0.87 g / cm ³
cm ³ and MFR (230 ° C., 2.16 kg) 10 g
/ 10 minutes or less, preferably 0.2 to 8 g / 10 minutes of ethylene / butene-1 copolymer rubber (EBM). Ethylene / butene-1 copolymer rubber (E
BM) is unsuitable because of poor paint adhesion performance and mechanical strength balance. Here, measurement was performed using a differential calorimeter (hereinafter, DSC, for example, RDC-220 manufactured by Seiko Denshi Kogyo) (20
℃ / min) with a melting peak temperature of 35 ° C. or lower,
Crystallinity measured by X-ray method is conventional (about 5 to 12%)
Those having a much lower content of 1% or less are particularly preferred in that they can improve the paint adhesion strength and impact strength of the composition. Conventionally, ethylene / butene-1 copolymer rubber (EB
In M), those having a butene-1 content of more than 25% by weight, those having a density of 0.87 g / cm ³ or less, that is, those having low crystallinity, and those having a melting temperature of 35 ° C. or less or crystals Those having a degree of conversion of 1% or less were extremely difficult to produce (especially in the form of pellets), but can be produced by improving the polymerization catalyst and the polymerization process, and the effects of the present invention can be exhibited. Was. The butene-1 content is a value measured by a conventional method such as an infrared spectrum analysis method. These ethylene-butene-1 copolymer rubbers are:
There is no particular limitation on the bale, pellet, flake, crumb, etc., and the production method is not particularly limited.

Blending Ratio The ethylene / butene-1 copolymer rubber (EB) of the component (b) blended in the propylene resin composition for coating of the present invention.
The mixing ratio of M) is 10 to 80 parts by weight, preferably 30 to 80 parts by weight, based on 100 parts by weight of the component (a).
Particularly preferably, the content is 40 to 80 parts by weight. When the compounding ratio is less than the above range, the paint adhesion performance and impact strength are poor, and when it exceeds the above range, the appearance of the molded product, the heat resistance rigidity and the dimensional stability are poor, and there is no practicality.

(C) Component (c): Filler Component constituting the propylene resin composition for coating of the present invention.
The filler component (c) has a substantially entire length of 15 μm.
Or less, preferably 10 μm or less, talc having an average particle size of 1.5 to 6 μm, preferably 1.5 to 4 μm, and an average aspect ratio of 5 or more, preferably 6 or more, and an average particle size of 8 to 100 μm And the average aspect ratio is 10
Above, preferably at least 15 mica, or at least one selected from fibrous fillers having an average diameter of 6 μm or less, preferably 0.1 to 5 μm, and an average aspect ratio of 5 or more. If the ratio is outside the above range, the mechanical strength balance of the composition is poor and the composition is inappropriate.

Of these, talc is particularly preferable because it can further enhance the balance between paint adhesion and mechanical strength. Here, the “substantially” length of talc means that most talc particles are in this range. Talc is produced by, for example, crushing raw talc with an impact mill or a micron-type pulverizer, finely pulverizing it with a micron mill or a jet-type pulverizer, and then classifying and adjusting it with a cyclone or a micron separator. Gemstones are preferred from China because of their low metal impurity content. Mica has different types and production methods such as white mica, gold mica, and black mica, and it is not particularly limited.However, white mica and gold mica are preferable. Gold mica is preferred. Examples of the fibrous filler include glass fiber, carbon fiber, aluminum borate fiber, potassium titanate fiber, basic magnesium sulfate fiber, and calcium carbonate fiber. Among them, those having an average diameter of 0.2 to 5 μm and an average aspect ratio of 10 or more are preferred.

Here, the measurement of the average particle size is a value measured using a laser light scattering type particle size distribution meter. As such a measuring device, for example, LA-500 manufactured by HORIBA, Ltd.
A mold is desirable because of its excellent measurement accuracy. Also, the diameter,
The length and the aspect ratio are values measured by a microscope or the like. These fillers are surfactants, coupling agents,
It may be surface-treated with metal soap or the like. The surface-treated filler is effective for further improving paint adhesion, mechanical strength, moldability, mold appearance, dimensional stability, and the like.

Blending Ratio The blending ratio of the filler of the component (c) blended in the propylene resin composition for coating of the present invention is 100% of the above-mentioned component (a).
5 to 80 parts by weight, preferably 5 to 60 parts by weight based on parts by weight
Parts by weight, particularly preferably 10 to 60 parts by weight.
When the compounding ratio is less than the above range, the heat resistance rigidity and dimensional stability are inferior, and when it exceeds the above range, the appearance of the molded product and the impact resistance are inferior, and there is no practicality. (d) Component (d): Modified propylene polymer Component constituting the propylene resin composition for coating of the present invention.
In the modified propylene polymer (d), maleic anhydride or a maleic anhydride derivative having a hydroxyl group represented by the following chemical formula is contained in the propylene polymer in an amount of 3 to 2 of the total amount of the component (d).
A modified propylene homopolymer, a modified propylene / ethylene block copolymer or a modified propylene / ethylene random copolymer grafted at a ratio of 5% by weight, preferably 5 to 20% by weight. The grafting is performed at least at one end of the main chain of the propylene-based polymer and / or in a form in which a graft monomer is bonded in the main chain.

[0022]

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(In the formula, R represents an alkylene group having 1 to 4 carbon atoms.) Here, the number average molecular weight of the main chain portion of the propylene polymer is preferably 1,000 to 20,000, and particularly preferably 3, 000 to 15,000 is preferred. The method for producing the modified propylene-based polymer is not particularly limited. For example,
After the propylene polymer is thermally oxidized in advance, a method of grafting a functional group or a method of grafting in an extruder or a solution can be used.

Blending Ratio The blending ratio of the modified propylene polymer of the component (d) blended in the propylene resin composition for coating of the present invention is 5 to 40 with respect to 100 parts by weight of the component (a). Parts by weight, preferably 10 to 40 parts by weight, particularly preferably 10 to 35 parts by weight. If the compounding ratio is less than the above range, the paint adhesion performance is inferior, and if it exceeds the above range, the mechanical strength balance is inferior and there is no practicality.

(E) Component (e): Phosphorus oxyacid compound Component constituting the propylene resin composition for coating of the present invention.
The phosphorus oxyacid compound component (e) is a compound having a structure in which an oxygen atom is directly bonded to a phosphorus atom (phosphoroxyacid structure), and among these, those having a phosphate ester structure are preferable, and in particular, Preferred are acidic phosphate ester derivatives. Specific examples include monobutyl phosphate,
Dibutyl phosphate, mono (2-ethylhexyl) phosphate, di (2-ethylhexyl) phosphate, mono (isodecyl) phosphate, di (isodecyl) phosphate, mono (lauryl) phosphate, di (lauryl) phosphate, Mono (tridecyl) phosphate, di (tridecyl) phosphate, mono (norylphenoxyethyl) phosphate and the like can be mentioned.

Compounding Ratio The compounding ratio of the component (e) of the phosphorus oxyacid compound component in the propylene resin composition for coating of the present invention is 0.05 to 100 parts by weight of the component (a). To 5 parts by weight, preferably 0.1 to 5 parts by weight, particularly preferably 0.5 to 2 parts by weight.
It is blended by weight. If the compounding ratio is less than the above range, the paint adhesion performance is inferior, and if it exceeds the above range, the mechanical strength balance is inferior and there is no practicality.

(F) Component (f): Diene polymer In the propylene resin composition for coating of the present invention, the diene polymer of the component (f) used as required is
It is a diene polymer having a hydroxyl group at a terminal or a hydrogenated product thereof. Among them, examples of the diene polymer having a hydroxyl group at a terminal include polyhydroxypolybutadiene. Specifically, it has at least one hydroxyl group at the terminal and has a molecular weight of 200 to 100,000, preferably 500 to 50,000, particularly preferably 800 to 10,000.
000 liquid, semi-solid, and solid polymers at room temperature. The average number of hydroxyl groups per molecule is generally 1 to 10,
Particularly, those having a hydroxyl value of 1.5 to 5 are preferable.
5 to 250, preferably 25 to 125 (KOHmg /
g) is preferred.

The diene polymer having a hydroxyl group at the terminal is
Using 1,3-diene as a raw material, a known method, for example,
It is produced by a radical polymerization method, an anion polymerization method or the like. Specifically, for example, JP-A-51-7139
No. 1 can be mentioned. When this is produced by radical polymerization, it is obtained by polymerizing a diene monomer using hydrogen peroxide as a polymerization initiator. In the case where the conjugated diene is produced by anionic polymerization, at least one terminal of the conjugated diene is obtained by polymerization using an anionic polymerization catalyst, for example, an alkali metal or an organic alkali metal compound, according to a known method. The living polymer having the bonded structure may be reacted with, for example, a monoepoxy compound, formaldehyde, acetaldehyde, acetone, a halogenoalkylene oxide, a polyepoxide, or the like. At least one kind of conjugated diene monomer is used as a raw material monomer for these polymers. Conjugated diene monomers include 1,3-butadiene,
3-pentadiene, isoprene, chloroprene, 2,3
-Dimethyl-1,3-butadiene, 1-phenyl-1,
3-butadiene and the like can be mentioned.

As the hydrogenated diene polymer having a hydroxyl group at the terminal, the diene polymer having a hydroxyl group at the terminal can be prepared by a conventional method, for example, as described in JP-A-51-7.
It can be obtained by hydrogenation according to the method described in JP-A-1391. The degree of hydrogenation may be such that the double bonds contained in the polymer are completely or partially hydrogenated, but the iodine value is usually 0 to 20,
In particular, those having 0 to 5 (g / 100 g) are preferable. These diene polymers having a hydroxyl group at the terminal or hydrogenated products thereof can be used alone or as a mixture of a plurality of them.

Blending Ratio The blending ratio of the diene polymer of the component (f) blended in the propylene-based resin composition for coating of the present invention is determined by the above-mentioned component (a).
0 to 10 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 1 to 5 parts by weight, per 100 parts by weight. If the compounding ratio is less than the above range, the paint adhesion performance is inferior, and if it exceeds the above range, the mechanical strength balance is inferior and there is no practicality.

(G) Component (g): Other components (optional components) In the propylene-based resin composition for coating of the present invention, the performance of the propylene-based resin composition of the present invention is not significantly impaired, or the performance is further improved. For the purpose of measurement, in addition to the essential components (a) to (f), any of the following additives and ingredients can be blended. Specifically, pigments for coloring, antioxidants, antistatic agents, flame retardants, dispersants, light stabilizers, nucleating agents, various resins other than the above components (a) to (f), various rubbers, Compounding materials such as various fillers can be given. Among them, ethylene-propylene binary copolymer rubber (EPM) and ethylene-propylene-diene terpolymer rubber (EPDM) are effective for improving paint adhesion strength, impact resistance and economy.

[II] Production of propylene-based resin composition (1) Kneading and granulation The above components (a) to (f) and, if necessary, component (g) are mixed in the above mixing ratio, and a single screw extruder is used. The propylene resin composition for coating of the present invention can be obtained by kneading and granulating using a conventional kneader such as a twin-screw extruder, a Banbury mixer, a roll mixer, a Brabender plastograph, a kneader and the like. In this case, it is preferable to select a kneading / granulating method capable of improving the dispersion of each component, and usually kneading / granulating is performed using a twin-screw extruder. During the kneading / granulation, the components (a) to (f), and optionally the component (g) may be kneaded at the same time, and each component may be divided to improve performance, for example, First, component (a)
It is also possible to knead some or all of the component (b) and then knead and granulate the remaining components.

(2) Molding The propylene-based resin composition for coating obtained in this manner can be molded by various molding methods, namely, injection molding, injection compression molding (press injection), compression molding, extrusion molding (sheet molding, Various molded products can be obtained by molding by film molding, blow molding, etc. Among these various molding methods, molding by injection molding (including gas injection molding) and injection compression molding (press injection). Is preferred.

[III] Use of Propylene-Based Resin Composition The propylene-based resin composition for coating of the present invention obtains excellent paintability, specifically, paints (particularly, generally high paint adhesion performance) on molded articles. It is possible to obtain practically sufficient paint adhesion performance by simply applying melamine-based paint directly) and baking at a temperature of 130 ° C. lower than before to use a melamine-based paint. It has a high balance of mechanical strength and good moldability and good adhesiveness and printability, and thus has practically sufficient performance as a molding material for various industrial parts.

[0035]

EXAMPLES In order to explain the propylene resin composition for coating of the present invention in more detail, specific examples will be described below with reference to experimental examples. However, the present invention is not limited to these experimental examples. Absent. [I] Raw materials (1) component (a) ... both powdery a-1: density of 0.9091g / cm polypropylene portion (A unit portion) of ³ 91% by weight, an ethylene content of 39% by weight of ethylene 9% by weight of a propylene random copolymerized portion (B unit portion), and the total polymerization MFR (230 ° C., 2.16 kg) of the component (a) is 11 g / 10
Component, (a) Propylene / ethylene block copolymer having an overall Mw / Mn of 8.4 a-2: 92% by weight of a crystalline polypropylene portion (A unit portion) having a density of 0.9093 g / cm ³ , 8% by weight of an ethylene-propylene random copolymer part (B unit part) having an ethylene content of 40% by weight, and the polymerization MFR (230 ° C., 2.16 kg) of the whole component (a) is 20 g / 10
Component, (a) Propylene / ethylene block copolymer having an overall Mw / Mn of 8.2 (2) Component (b) ... All pellets b-1: Butene-1 content 33% by weight, MFR ( 230
° C, 2.16 kg) 1.1 g / 10 min, density 0.86 g
/ Cm ³ , DSC melting peak temperature 26 ° C., ethylene-butene-1 copolymer rubber (EBM) having a crystallinity of 1% or less (almost not recognized) by X-ray method b-2: butene-1 content 32 Wt%, MFR (230
° C, 2.16 kg) 6.3 g / 10 min, density 0.86 g
/ Cm ³ , DSC melting peak temperature of 25 ° C., X-ray crystallinity of 1% or less (almost not recognized), ethylene-butene-1 copolymer rubber (EBM)

(3) Component (c) ... powder-like c-1: substantially the entire length is 10 μm or less;
Talc having an average particle diameter of 2.7 μm and an average aspect ratio of 6 c-2: Basic magnesium sulfate fiber having an average diameter of 0.4 μm and an average aspect ratio of 33 (4) Component (d)… flake-like d- 1: MFR (230 ° C., 2.16 kg) 60 g /
The propylene / ethylene random copolymer having a number-average molecular weight of 6,800 and an ethylene content of 4% by weight is thermally oxidized for 10 minutes, and furthermore, the component (B) is added to both ends of the main chain and in the main chain by an azo radical initiator. d) A modified propylene polymer obtained by grafting maleic anhydride groups at a ratio of 10% by weight of the whole and further modifying the maleic anhydride groups with ethanolamine. (5) Component (e): liquid e-1: phosphoric acid Mono (2-ethylhexyl)) ester (6) Component (f) flakes f-1: iodine value 1.3 (g / 10 minutes), hydroxyl value 8
5.6 (KOH mg / cm ³ hydrogenated diene polymer)

[II] Evaluation method Evaluation was performed by the following method. [Coating] (Paint) A one-component organic solvent-based melamine cross-linking paint was used. (Coating method) The preform was not applied at all to the formed flat plate, and the flat plate was spray-coated using an air spray gun so that the coating film thickness was about 25 µm. (Baking treatment) The coated flat plate was baked and dried at 130 ° C. for 15 minutes (data of baking drying at 140 ° C. for 20 minutes was added to Comparative Example 1). Then, it was left at room temperature for 48 hours.

[Evaluation of Coating Adhesion] (Initial cross-cut test) Using a single-edged razor, 11 parallel vertical and horizontal parallel lines were drawn at 2 mm intervals on the surface of the baked and coated test specimen to obtain a grid of 100. I made one. A cellophane adhesive tape (JIS-Z1522) was sufficiently pressed on it, the film was kept at about 30 degrees with the coating surface, and the work of peeling off at once was repeated five times. Observe the state of the area enclosed by the grid. The number of grids that did not peel off was recorded. (Water resistance grid test) First, the painted test piece subjected to the baking treatment was immersed in 40 ° C. hot water for 240 hours, and then baked.
Left at room temperature for hours. Thereafter, using a single-edged razor, 100 parallel grids were formed by drawing 11 parallel vertical and horizontal lines at 2 mm intervals. Cellophane adhesive tape (JI
S-Z1522) was sufficiently pressed, kept at about 30 ° with the coating film surface, and repeatedly peeled off at a stretch in front of it five times. Observing the state of the portion surrounded by the grid, the grid that did not peel off was observed. The number was recorded. At this time, the test piece without peeling was further repeated five times. Usually, if there is no peeling in the first five times, it is a practical level.

[Evaluation of mechanical strength] (Flexural modulus) Measured in accordance with JIS-K7203. The measurement temperature is 23 ° C. This value is also a measure of heat resistance. Particularly, those having 1,400 MPa or more are useful for various industrial parts, and those having 1,500 MPa or more are particularly useful. (Izod impact strength) Measured according to JIS-K7110 (with notch). The measurement temperature is -30C.
Particularly, those having 5 KJ / m ² or more are useful for various industrial parts, and those having 6 KJ / m ² or more are particularly useful.

[Molding Processability] (Spiral (flow) length, MFR) As a guide of the molding processability, using a screw in-line type injection molding machine,
Spiral mold (flow sectional shape: upper side = 13 mm, lower side = 14.5 mm, thickness = 3 mm, gate = direct)
The flow length at was measured. The molding conditions at this time were: molding temperature = 220 ° C., mold temperature = 20 ° C., screw rotation speed 70 rpm, injection pressure = 600 kg / cm ² .
In particular, those having a size of 1,200 mm or more have good moldability. For some samples, the MFR was
It measured based on S-K7210 (230 degreeC, 2.16 kg). In this case, those having an MFR of 8 g / 10 min or more have good moldability, and those having a MFR of 12 g / 10 min or more are particularly good.

[Light Weight] (Density) Measured at 23 ° C. according to JIS-K7112. Especially 1.05 g / cm ³ or less, particularly 1.03 g / cm ³
Those having a size of not more than cm ³ have excellent strength despite their light weight and are preferred.

[III] Experimental Examples Examples 1 to 7 and Comparative Examples 1 to 7 The above components (a), (b), (c), (d),
(e) and the component (f) were blended in the proportions shown in Table 1, and tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane was further added to the component. 0.1 parts by weight of each of (a) to component (e) or (a) to (f) in terms of a total amount of 100 parts by weight were blended, and these were thoroughly mixed with a high-speed mixer (see Table 1). 1
When the component c-2 was used as the filler, the fiber portion was excluded, and the mixture was fed halfway by a subsequent extruder. ).
After that, a high-speed twin-screw extruder (KCM) manufactured by Kobe Steel, Ltd.
Using a mold), and kneaded and granulated under a temperature condition of 210 ° C.,
The obtained pellets were supplied to the injection molding machine to form a coating sheet test piece and a physical property measurement test piece, which were evaluated. Table 2 shows the evaluation results. As shown in Tables 1 and 2, the resin compositions having the compositions shown in Examples 1 to 7 all had good paint adhesion performance, mechanical strength balance, and moldability, and were lightweight. . on the other hand,
Those shown in Comparative Examples 1 to 7 were poor in their performance balance.

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

EFFECTS OF THE INVENTION The propylene resin composition for coating of the present invention has excellent coatability, specifically, a paint (particularly, generally less than 150 ° C.) can be applied to a molded product without TCE pretreatment or primer application. In the baking drying, the melamine-based resin, which is difficult to obtain high paint adhesion performance, is applied directly, and even under an effective baking drying condition of 130 ° C. for about 15 minutes, sufficient practical coating adhesion performance can be obtained. It has high mechanical strength balance (especially high rigidity and low-temperature impact strength) and extremely good moldability,
Since it is lightweight and has excellent dimensional stability, it can be expected to be applied as various industrial parts, and is an industrially important material.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 9:00 C08L 23:08 23:08 51:06 51:06) (56) References JP-A-8-100087 (JP, A) JP-A-8-41276 (JP, A) JP-A-8-3394 (JP, A) JP-A-7-118488 (JP, A) JP-A-6-9835 (JP, A) JP-A-5 -262924 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 53/00

Claims (6)

(57) [Claims] 1. A propylene resin composition for coating, comprising the following components (a) to (f): Component (a): a propylene / ethylene block copolymer containing a crystalline polypropylene portion (A unit) and an ethylene / propylene random copolymer portion (B unit): 100 parts by weight Component (b): butene- Ethylene / butene-1 copolymer rubber having a content of 25 to 40% by weight, a density of 0.87 g / cm ³ or less and a melt flow rate (230 ° C., 2.16 kg) of 10 g / 10 minutes or less: 10 -80 parts by weight Ingredient (c): talc having a substantially whole length of 15 µm or less, an average particle size of 1.5 to 6 µm and an average aspect ratio of 5 or more, an average particle size of 8 to 100 µm, and Mica having an average aspect ratio of 10 or more, or at least one filler selected from fibrous fillers having an average diameter of 6 μm or less and an average aspect ratio of 5 or more: 5 to 80 parts by weight Component (d) A modified propylene homopolymer or a modified propylene homopolymer obtained by grafting maleic anhydride or a maleic anhydride derivative having a hydroxyl group represented by the following chemical formula to a propylene-based polymer at a ratio of 3 to 25% by weight of the whole component (d). Or random copolymer of ethylene and ethylene: 5 to 40 parts by weight (Wherein, R represents an alkylene group having 1 to 4 carbon atoms.) Component (e): Phosphoric acid compound: 0.05 to 4 parts by weight Component (f): Diene polymer having a hydroxyl group at a terminal or hydrogen thereof Additives: 0 to 10 parts by weight 2. Component (a) is characterized in that the A unit occupies 60 to 95% by weight of the block copolymer and has a density of 0.9070 g.
/ Cm ³ or more, and the B unit part is 5% of the block copolymer.
エ チ レ ン 40% by weight, the ethylene content thereof is 20-80% by weight, and the melt flow rate (230 ° C., 2.16 kg) of the whole component (a) is 5-100 g / 10 min. ) The total weight average molecular weight / number average molecular weight is 7
The propylene-based resin composition for coating according to claim 1, which is a block copolymer as described above. 3. An ethylene / butene-1 copolymer rubber (EBM) as the component (b) is melted (peak) by a differential calorimeter.
The propylene-based resin composition for coating according to claim 1, wherein the temperature is 35 ° C or lower. 4. Component (d) is obtained by grafting a hydroxyl group-containing maleic anhydride derivative represented by the following chemical formula to a propylene-based polymer at a ratio of 5 to 20% by weight of the entire component (c). The propylene resin composition for coating according to claim 1, which is a modified propylene homopolymer of 4,000 to 13,000 or a block or random copolymer of propylene and ethylene. Embedded image 5. The propylene resin composition for coating according to claim 1, wherein the component (e) is an acid phosphate derivative. 6. The resin composition has a flexural modulus of 1,400 MPa.
a, -30 ° C Izod impact strength of 5 KJ / m ² or more, spiral length of 1,200 mm or more, and density of 1.
And has a 05G / cm ³ or less performance, paint propylene resin composition according to claim 1.