JPH0948886A - Resin composition excellent in coating property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin composition good in adhesion of films without requiring the surface treatment such as degreasing and washing with a halogen-based organic solvent, primer coating or plasma irradiation. SOLUTION: This resin composition excellent in coating properties comprises (a) 35-80wt.% propylene homopolymer or propylene-ethylene copolymer, (b) 10-45wt.% ethylene-α-olefin copolymer rubber (with the proviso that ethylene is not included), (c) 0-20wt.% inorganic filler and (d) 5-20wt.% styrene- ethylene.propylene block copolymer modified with acrylic acid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent coatability, and in particular, it does not require surface treatment such as degreasing and washing with a halogen-based organic solvent, primer coating, plasma irradiation, etc. The present invention relates to a resin composition having excellent coatability.

[0002]

2. Description of the Related Art Since polypropylene is lightweight and has excellent mechanical strength and the like, it is widely used in various industrial fields such as interior and exterior parts of automobiles and home electric appliances. . However, since polypropylene is a non-polar polymer, there is a problem that the secondary processability, particularly the adhesion in a solid state with a polar coating material is low and the coating property is poor.

For the purpose of improving the adhesion between polypropylene and a coating film, a mixture of a polypropylene resin and a styrene resin, a block copolymer of an aromatic vinyl compound and a conjugated diene compound, or the like is used. A method of adding a modified copolymer to which the derivative is added is disclosed (JP-A-4-502248). However, this method requires degreasing and cleaning treatment with a halogen-based organic solvent such as 1,1,1-trichloroethane before coating, and then plasma treatment in order to introduce polar groups onto the surface of the base material. Is. Such a halogen-based organic solvent has a problem that it has an adverse effect on the human body and the environment. In addition, the plasma processing complicates the working process and is uneconomical in terms of time.

A method of applying a primer coating instead of such a plasma treatment is known, but this method complicates the working process and requires a large amount of an organic solvent, resulting in a high manufacturing cost. There is a problem.

Therefore, an object of the present invention is to provide a resin composition which does not require surface treatment such as degreasing and washing, primer coating, and plasma irradiation with a halogen-based organic solvent, and has good coatability and excellent coatability. Is to provide.

[0006]

As a result of earnest research in view of the above problems, the present inventors have found that a propylene homopolymer or a propylene-ethylene copolymer, an ethylene / α-olefin copolymer rubber, and an inorganic filler. A resin component consisting of styrene-ethylene modified with acrylic acid
By blending the propylene block copolymer, there is no need for degreasing cleaning with a halogen-based organic solvent, primer coating, surface treatment such as plasma irradiation, and a resin composition having excellent coating properties with good coating adhesion can be obtained. The inventors have found that they can be obtained and have conceived the present invention.

That is, the resin composition having excellent coatability of the present invention comprises (a) 35 to 80% by weight of a propylene homopolymer or propylene-ethylene copolymer, and (b) ethylene / α.
-Olefin (excluding ethylene) copolymer rubber 10 to 45% by weight, and (c) inorganic filler 0 to 20% by weight
And (d) a styrene-ethylene / propylene block copolymer modified with acrylic acid.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. [1] Each component of resin composition having excellent coatability (a) Propylene homopolymer or propylene-ethylene copolymer Melt flow rate of propylene homopolymer used in the present invention (MFR, 230 ° C., load 2.16 kg) Is measured from 1 to 120 g from the viewpoint of moldability and impact resistance.
/ 10 minutes is preferable, and 10 to 90 g / 10 minutes is more preferable.

The method for producing the propylene homopolymer is not particularly limited, but a polymerization method using a stereoregular catalyst is preferable. As the stereoregular catalyst, titanium trichloride, titanium tetrachloride, titanium halide compounds such as trichloroethoxy titanium, transition metal components such as a contact product of the titanium halide compound and a magnesium compound represented by magnesium halide. Alkylaluminum compounds or their binary catalysts with organometallic components such as halides, hydrides, alkoxides, etc., and electron donating compounds containing nitrogen, phosphorus, sulfur, oxygen, silicon, etc. added to these components 3 Component type catalysts may be mentioned.

The polymerization reaction of propylene homopolymer is
It may be performed in either a gas phase or a liquid phase. For example, when polymerizing in a liquid phase, it can be carried out in an inert hydrocarbon such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, xylene or a liquid monomer. . The polymerization temperature is usually −80 to 150 ° C., preferably 4
0-120 ° C. The polymerization pressure is preferably 1 to 60 atm, and the molecular weight of the resulting polymer can be adjusted with hydrogen or other known molecular weight regulators. Polymerization is carried out by a continuous or batch reaction, and the conditions may be those usually used. Furthermore, the polymerization reaction may be carried out in one stage or in two stages.

The propylene-ethylene copolymer used in the present invention may be any of a block copolymer, a random copolymer and an alternating copolymer. From the viewpoint of moldability and impact resistance, the MFR of the propylene-ethylene copolymer is 1 to 1.
20 g / 10 minutes is preferable, and 10-90 g / 10 minutes is more preferable.

The method for producing the propylene-ethylene copolymer is also not particularly limited, but in the above-mentioned propylene polymerization, a propylene homopolymer is produced in the preceding stage, and then ethylene is added to produce a propylene-ethylene copolymer. Method or an ethylene homopolymer or a propylene-ethylene copolymer is produced in advance by the same production method as the propylene homopolymer, and this is mechanically mixed with the propylene homopolymer and the post-reactor blend. There are ways.

(B) Ethylene / α-olefin copolymer rubber Ethylene / α-olefin copolymer rubber is a copolymer rubber of ethylene and α-olefin other than ethylene, for example, ethylene-propylene copolymer. Rubber (EP
R) and ethylene obtained by copolymerizing this with a diene compound
Examples thereof include propylene-diene copolymer rubber (EPDM) and ethylene-butene copolymer rubber (EBR).

Specifically, the ethylene-propylene copolymer rubber (EPR) preferably has an ethylene content of 90 to 50 mol% and a propylene content of 10 to 50 mol%. A more preferable range is that the ethylene content is 70 to 80 mol% and the propylene content is 30 to 20 mol%. In the case of ethylene-propylene-diene copolymer rubber (EPDM), examples of the diene compound include ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene. Ethylene-propylene copolymer rubber (ethylene-propylene-
(Including diene copolymer rubber) has an MFR of 0.5 to 20.
g / 10 minutes is preferable, and 0.5-10 g / 10 minutes is more preferable.

Further, ethylene-butene copolymer rubber (EB
R) has an ethylene content of 70 to 85 mol%,
The butene-1 content is preferably 30 to 15 mol%. A more preferable range is that the ethylene content is 75 to
It is 85 mol% and the content of butene-1 is 25 to 15 mol%. Ethylene-butene copolymer rubber (EBR)
The MFR of 1 to 30 g / 10 minutes is preferable, and 1 to 20
g / 10 minutes is more preferable. Such an EBR may contain, in addition to ethylene and butene-1, a small amount of other α-olefins such as hexene-1, octene-1 and diene compounds such as ethylidene norbornene and dicyclopentadiene.

The ethylene / α-olefin copolymer rubber as described above may be used alone or
You may mix and use 1 or more types suitably.

(C) Inorganic filler The inorganic filler used in the present invention is generally used as a filler and a reinforcing material for resins and the like, and examples thereof include talc, mica, fiber crystalline calcium silicate and calcium carbonate. Can be mentioned. Of these, talc is particularly preferable. It is preferable to use an inorganic filler having an average particle diameter of 15 μm or less. In the case of needle-like or fibrous substances, those having a fiber diameter of 1 to 100 μm and an aspect ratio of 3 to 30 are preferable.

(D) Styrene-ethylene / propylene block copolymer modified with acrylic acid Styrene modified with acrylic acid used in the present invention
In the ethylene / propylene block copolymer (hereinafter, referred to as modified styrene-ethylene / propylene block copolymer), styrene-ethylene.
The propylene block copolymer is represented by the following general formula (I). (S-EP) _n -S _m ··· (I) (where S is a block of a polymer of a monovinyl-substituted aromatic hydrocarbon, EP is an ethylene / propylene moiety, and n is 1 to 20). It is an integer and m is 0 or 1.)

Such a styrene-ethylene / propylene block copolymer is prepared at 25-175 ° C. in the presence of a catalyst obtained by reducing a styrene-isoprene block copolymer with a cobalt or nickel alkoxide with an alkylaluminum compound. By hydrogenating at a temperature, only the isoprene portion is selectively hydrogenated to form a structure corresponding to an ethylene / propylene copolymer.

In the styrene-ethylene / propylene block copolymer, it is not necessary that all isoprene moieties be hydrogenated, and 5% or more may be hydrogenated. The hydrogenation ratio is preferably 50% or more, more preferably 80% or more.

The content of the block of the monovinyl-substituted aromatic hydrocarbon polymer in the styrene-ethylene / propylene block copolymer is preferably 10 to 70% by weight, and preferably 15 to 40% by weight. Is more preferable. The number average molecular weight of the styrene-ethylene / propylene block copolymer is preferably 10,000 to 200,000, more preferably 50,000 to 100,000.

The styrene-ethylene / propylene block copolymer modified with acrylic acid is a block copolymer,
It may be a graft copolymer, a random copolymer or an alternating copolymer.

The content (modification amount) of acrylic acid in the modified styrene-ethylene / propylene block copolymer is 1
-20% by weight is preferable, and 1-10% by weight is more preferable. If the content of acrylic acid is less than 1% by weight, the effect of improving the paintability is not sufficient, while 20% by weight
If it exceeds, the mechanical strength will decrease.

Further, the melt flow rate (MFR, 20) of the modified styrene-ethylene / propylene block copolymer
Measured at 0 ° C. and a load of 10 kg) is 0.1 to 150 g / 10
Minutes are preferable, and 10 to 150 g / 10 minutes are more preferable. If the MFR is less than 0.1 g / 10 minutes, the moldability is low, while if it exceeds 150 g / 10 minutes, the mechanical strength is reduced.

The modified styrene-ethylene / propylene block copolymer can be produced by either a solution method or a melt-kneading method. In the case of the melt kneading method, the styrene-ethylene / propylene block copolymer, the acrylic acid for modification, and the catalyst are charged into an extruder, a twin-screw kneader, or the like,
Heat to a temperature of 250 ° C. and knead while melting. In the case of the solution method, the above-mentioned starting material is dissolved in an organic solvent such as xylene and the stirring is performed at a temperature of 100 to 120 ° C. In any case, as the catalyst, benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, acetyl peroxide, t-butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, t- Butyl peroxypivalate, 2,5-dimethyl-2,5-
Ordinary radical polymerization catalysts such as peroxides such as di-t-butylperoxyhexyne and diazo compounds such as azobisisobutyronitrile can be used.

Since the modified styrene-ethylene / propylene block copolymer has a high affinity with a coating material having polarity, it is possible to improve the coating property by adding it to the resin.

[2] Blending Ratio The blending ratio of each component of the resin composition as described above is 35 to 80% by weight, preferably 40 to 60% by weight of propylene homopolymer or propylene-ethylene copolymer. , Ethylene / α-olefin copolymer rubber 10-4
5% by weight, preferably 20-40% by weight, inorganic filler 0-20% by weight, preferably 5-15% by weight, modified styrene-ethylene / propylene block copolymer 5-20% by weight, It is preferably 5 to 15% by weight.

If the content of the propylene homopolymer or propylene-ethylene copolymer is less than 35% by weight, the ductility, hardness, etc. of the resulting composition are low, while if it exceeds 80% by weight, the impact resistance is lowered. When the ethylene / α-olefin copolymer rubber is less than 10% by weight, the tensile strength is low,
On the other hand, when it exceeds 45% by weight, moldability and heat resistance are deteriorated. On the other hand, if the content of the inorganic filler exceeds 20% by weight, the impact resistance decreases. Further, when the amount of the modified styrene-ethylene / propylene block copolymer is less than 5 parts by weight, the effect of improving the coating property is not sufficient, while when it exceeds 20 parts by weight, the effect of improving the coating property corresponding to it is not sufficient. can not see.

[3] Other Components The resin composition of the present invention having excellent coatability has other additives such as a heat stabilizer, an antioxidant, a light stabilizer, and a hardener for the purpose of modifying the resin composition. A flame retardant, a plasticizer, an antistatic agent, a release agent, a foaming agent, a coloring agent, a pigment and the like can be added.

[4] Method for producing resin composition having excellent coatability In the resin composition having excellent coatability of the present invention, the above components are mixed using a Henschel mixer, a super mixer, a ribbon blender or the like, and uniaxial extrusion is performed. It can be obtained by melt-kneading in a temperature range of 180 to 230 ° C. with a machine, a twin-screw extruder, a Banbury mixer, a kneader or the like.

[0031]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. Examples 1-9 and Comparative Examples 1-5 1. Raw material (a) Propylene homopolymer or propylene-ethylene copolymer PP1: Propylene-ethylene block copolymer MFR = 25g / 10min (measured at 230 ° C, load 2.16kg) Cold xylene soluble portion ratio = 13% by weight PP2: Propylene-ethylene block copolymer MFR = 40g / 10min Proportion of cold xylene soluble part = 13% by weight

(B) Ethylene / α-olefin copolymer rubber EPR1: Ethylene-propylene copolymer rubber (EP02P, manufactured by Nippon Synthetic Rubber Co., Ltd.) MFR = 3.2 g / 10 min Ethylene content = 74 mol% EPR2: Ethylene-propylene copolymer rubber (EP07P, manufactured by Nippon Synthetic Rubber Co., Ltd.) MFR = 0.7g / 10min Ethylene content = 73mol%

(C) Inorganic filler Talc: LMR100 (manufactured by Fuji Talc Co., Ltd.) Average particle size = 2 μm

(D) Modified styrene-ethylene / propylene block copolymer modified with acrylic acid Modified SEPS: modification amount = 5% by weight styrene content = 30% by weight MFR = 100 g / 10 min (measured at 200 ° C., load 10 kg)

2. Kneading and molding method The above raw materials were blended in the proportions shown in Tables 1 and 2, and dry blended using a super mixer, and then 200 r at 200 ° C with a twin-screw extruder (PCM-45 manufactured by Ikegai Corp.).
The mixture was melt-kneaded at a screw rotation speed of pm and extruded to obtain pellets. The pellets thus obtained were injection-molded by an injection molding machine at a resin temperature of 210 ° C., an injection pressure of 650 kg / cm ² and a mold temperature of 50 ° C. to prepare a test piece.

3. Physical property measurement Physical property measurement of each test piece was performed by the following methods. The results are shown in Tables 1 and 2 below. (1) Tensile strength (kg / cm ² ): Measured at room temperature according to ASTM D638. (2) Tensile elongation at break (%): Measured at room temperature according to ASTM D638. (3) Flexural modulus (kg / cm ² ): Measured at room temperature according to ASTM D790. (4) Flexural strength (kg / cm ² ): Measured at room temperature according to ASTM D790. (5) Izod impact strength (kgcm / cm): Measured at -30 ° C with a notch using a 3.2 mm thick test piece according to ASTM D256. (6) Heat distortion temperature (℃): 18.6kg / cm ^{2 according} to ASTM D648
The pressure was measured. (7) Rockwell hardness (scale R): Measured according to ASTM D785. (8) Brittleness temperature (° C): Measured by ASTM D746. (9) Adhesion: Wipe the test piece with gauze containing isopropyl alcohol, apply a paint with a solid content of 30%, and apply 30% at 80 ° C.
A coating film was formed by baking for minutes. The adhesive strength (primary adhesive strength) after leaving the obtained coated molded article for 24 hours or more under the conditions of 23 ° C. and 50% humidity was evaluated by the edge peeling test according to JIS D0202 4.15. The adhesion strength (secondary adhesion strength) of the coating film after being immersed in warm water at 40 ° C for 240 hours was also evaluated. ◯: Peeling does not occur at all. X: Peeling occurred even a little.

Table 1 Example No. 1 2 3 4 5 composition (wt%) PP1 55 50 45 60 40 PP2 ─ ─ ─ ─ ─ EPR1 30 30 30 30 20 40 EPR2 ─ ─ ─ ─ Talc 10 10 10 10 10 Modified SEPS 5 10 15 10 10 Composition Characteristic Tensile strength (kg / cm ² ) 180 175 169 184 163 Tensile elongation at break (%) 570 590 660 530 670 Flexural modulus (kg / cm ² ) 9400 8900 8500 10500 7300 Bending strength (kg / cm ² ) 203 198 190 209 182 Izod impact strength ⁽¹⁾ 8 14 NB 6 NB Heat distortion temperature (℃) 97 93 89 98 87 Rockwell hardness (R) 32 31 29 36 22 Embrittlement temperature (℃) -41 -45 -50 -38 -53 Primary adhesion strength ○ ○ ○ ○ ○ Secondary adhesion strength ○ ○ ○ ○ ○ Note (1) Unit: kg ・ cm / cm, NB: No destruction.

Table 1 (continued) Example No. 6 7 8 9 Composition (wt%) PP1 ─ 50 55 45 PP2 50 ─ ─ ─ EPR1 30 ─ 30 30 EPR2 ─ 30 ─ talc 10 10 5 15 Modified SEPS 10 10 10 10 Characteristic tensile strength of composition (kg / cm) ² ) 174 174 172 172 Tensile elongation at break (%) 500 580 550 300 Flexural modulus (kg / cm ² ) 8800 8800 8600 9400 Bending strength (kg / cm ² ) 197 195 194 202 Izod impact strength 13 15 17 7.7 Heat Deformation temperature (℃) 94 93 89 98 Rockwell hardness (R) 30 30 32 30 Embrittlement temperature (℃) -43 -44 -44 -39 Primary adhesion strength ○ ○ ○ ○ Secondary adhesion strength ○ ○ ○ ○

Table 2 Comparative Example No. 1 2 3 4 5 Composition (wt%) PP1 50 60 70 ─ 60 PP2 ─ ─ ─ 60 ─ EPR1 40 30 20 30 ─ EPR2 ─ ─ ─ ─ 30 Talc 10 10 10 10 10 modified SEPS ─ ─ ─ ─ ─ composition Characteristic Tensile strength (kg / cm ² ) 175 180 186 181 178 Tensile elongation at break (%) 660 650 430 500 660 Flexural modulus (kg / cm ² ) 8500 10000 11500 10500 10000 Bending strength (kg / cm ² ) 195 205 216 204 206 Izod impact strength ⁽¹⁾ 15 6.5 4.5 6 7.5 Heat distortion temperature (℃) 88 95 101 94 96 Rockwell hardness (R) 28 32 36 33 31 Brittle temperature (℃) -45 -40 -34 -37 -42 Primary adhesion strength × × × × × Secondary adhesion strength × × × × × Note (1) Unit: kg · cm / cm.

As is apparent from Tables 1 and 2, Example 1
The resin compositions of Nos. 9 to 9 are excellent in impact resistance, heat resistance and the like and have good coating film adhesion, but Comparative Examples 1 to 5
The resin composition (1) has inferior adhesion to the coating film.

[0041]

As described in detail above, the resin composition having excellent coatability of the present invention is a propylene homopolymer or a propylene-ethylene copolymer and an ethylene / α-olefin (provided that ethylene is not included). (1) Since it is composed of a copolymer rubber, an inorganic filler, and a styrene-ethylene / propylene block copolymer modified with acrylic acid, it can be used for surface treatment such as degreasing cleaning with a halogen-based organic solvent, primer coating, and plasma irradiation. There is no need, and the adhesion of the coating film is good. Such a resin composition having excellent coatability of the present invention can be applied to various uses, but is particularly suitable for automobile exterior parts such as bumpers and side moldings.

Claims (2)

[Claims] 1. (a) 35 to 80% by weight of propylene homopolymer or propylene-ethylene copolymer, and (b) 10 to 45% by weight of ethylene / α-olefin (excluding ethylene) copolymer rubber. %, (C) inorganic filler 0 to 20
% By weight, and (d) styrene modified with acrylic acid
5-20% by weight of ethylene / propylene block copolymer
A resin composition having excellent coatability, which comprises: 2. The resin composition having excellent coatability according to claim 1, wherein the styrene-ethylene / propylene block copolymer (d) modified with acrylic acid is used in an amount of 10% or less.
0% by weight, the content of acrylic acid is 1 to 20% by weight
A resin composition having excellent coatability, characterized in that