JPH11217537A - Primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a nonchlorine-based primer composition capable of imparting good adhesion by coating without carrying out pretreatment of a polyolefin molded product with a chlorine-based organic solvent and good in storage stability and a modified copolymer used as a principal component of the composition. SOLUTION: This primer composition contains a modified copolymer prepared by adding at least one kind selected from substituent groups represented by formulae (a) to (c) [R<1> , R<3> and R<5> are each a >=2C alkylene group; R<2> , R<4> and R<6> are each a 1-40C alkyl group; (n) is an integer of 1-40] as a grafting chain to a propylene-butene copolymer or a propylene-butene-ethylene copolymer and an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition and a modified copolymer, and more particularly, to a method of coating a surface of various molded products without cleaning them with a chlorine-based organic solvent, thereby improving the surface of the molded products. The present invention relates to a primer composition capable of imparting excellent paint adhesion and a modified copolymer used as a main component of the composition.

[0002]

2. Description of the Related Art Heretofore, it has been practiced to apply a paint on the surface of a molded product of polyolefin such as polypropylene or to form another polar resin layer to increase the added value.
However, polyolefins generally have low polarity and poor adhesion to paints and resins.

[0003] Therefore, it has been practiced to improve the adhesion of paint by treating the surface of a molded article with a primer. Various compositions have been proposed as the primer (Japanese Patent Publication Nos. 59-42693, 61-11250, 62-21027, and JP-A-2-11016).
No. 8, No. 3-109471).

However, none of the conventional primers including the above-mentioned composition has been subjected to steam cleaning of a chlorine-based organic solvent such as 1,1,1-trichloroethane as a pretreatment of a material to be coated. In such a case, there was a drawback that adhesion was not exhibited. On the other hand, in recent years, the use of chlorine-based organic solvents has been restricted or prohibited due to environmental protection and improvement of workability. Therefore, various compositions using various chlorinated polypropylene as a raw material as a primer have been proposed.

[0005] In addition, recycling of automotive components such as bumpers is being promoted, and it has been found that the use of chlorine-based paints and primers is not preferable in recycling. Therefore, with a primer of non-chlorine composition, without the need for pretreatment of chlorine organic solvent,
It has been desired to develop a primer having good adhesion to a material.

[0006] In order to solve the above-mentioned problems, the present inventors graft copolymerize at least one selected from monoolefin dicarboxylic acid and its anhydride on a propylene / butene / ethylene terpolymer. A primer composition containing a modified polyolefin as a main component has been previously proposed (JP-A-4-363372). However, although this primer composition has solved the above-mentioned problems, it has a drawback that the stability of the solution, particularly the long-term storage stability is low.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to apply a polyolefin molded product represented by polypropylene to a molded product without pretreatment with a chlorine-based organic solvent to impart good adhesion. It is an object of the present invention to provide a chlorine-free primer composition having good storage stability and a modified copolymer used as a main component of the composition.

[0008]

Means for Solving the Problems In order to solve the above problems, the present invention relates to a propylene / butene copolymer or a propylene / butene / ethylene copolymer represented by the following formula (a):
(C):

Embedded image (In the formula, R ¹ , R ³ and R ⁵ may be the same or different and each is an alkylene group having 2 or more carbon atoms, and R ² , R ⁴
And R ⁶ may be the same or different and have 1 to 4 carbon atoms.
A modified copolymer obtained by adding at least one selected from substituents represented by the following formulas as a graft chain, and an organic solvent: To provide.

[0009] The present invention also relates to a modified copolymer used as a main component of the primer composition, wherein a propylene / butene copolymer or a propylene / butene / ethylene copolymer is prepared by adding an unsaturated carboxylic acid and its derivative. After graft copolymerization of at least one selected, the following formulas (A) to (C):

Embedded image (In the formula, R ¹ , R ³ and R ⁵ may be the same or different and each is an alkylene group having 2 or more carbon atoms, and R ² , R ⁴
And R ⁶ may be the same or different and have 1 to 4 carbon atoms.
0 is an alkyl group, and n is an integer of 1 to 40) to provide a modified copolymer obtained by reacting at least one compound selected from the group consisting of:

Hereinafter, the primer composition of the present invention and the modified copolymer which is a main component of the composition will be described in detail.

The modified copolymer which is the main component of the primer composition of the present invention is obtained by adding the above-mentioned formula (a) to a propylene / butene copolymer or a propylene / butene / ethylene copolymer binary or ternary copolymer. ) To (c) in which at least one selected from the substituents is added as a graft chain.

The propylene / butene copolymer which is a main component of the modified copolymer has one or more structural units derived from propylene and one or more structural units derived from butene in a molecule. And a propylene / butene / ethylene copolymer, which is derived from one or more structural units derived from propylene, one or more structural units derived from butene, and one or more ethylene units in the molecule. Copolymers having the structural units described above, and these copolymers may be random copolymers or block copolymers.

The content of propylene in the propylene / butene copolymer or propylene / butene / ethylene copolymer is usually 90 to 10 mol%, preferably 90 to 50 mol%. The butene content is usually 45 to 5 mol%, preferably 35 to 1 mol%.
0 mol%. Furthermore, the content of ethylene is usually
It is 25 to 0 mol%, preferably 20 to 0 mol%.

In addition, these propylene / butene copolymers or propylene / butene / ethylene copolymers have a high cohesive force of the primer composition obtained, and the coating film obtained by applying the composition to a molded product is insufficient. In view of having a good cohesive force and dissolving a modified product of this copolymer in an organic solvent and exhibiting good solution viscosity, the intrinsic viscosity [η] measured at 135 ° C. in decalin is 0.22. To 2 dl / g, particularly preferably 0.3 to 1 dl / g.

These propylene / butene copolymers or propylene / butene / ethylene copolymers can be produced according to a conventional method. For example, it can be produced by copolymerizing propylene and butene or propylene, butene and ethylene using a vanadium catalyst or a titanium catalyst containing magnesium, titanium, halogen or the like as a main component.

The substituent added as a graft chain to the modified copolymer is at least one selected from those represented by the following formulas (a) to (c).

[0017]

Embedded image

In the above formulas (a) to (c), R ¹ , R
³ and R ⁵ may be the same or different and are an alkylene group having 2 or more carbon atoms. Also, R ² , R ⁴ and R ⁶
May be the same or different and are an alkyl group having 1 to 40 carbon atoms. The alkyl group having 1 to 40 carbon atoms may be linear or branched, for example, a methyl group,
Examples thereof include an ethyl group, a propyl group, a butyl group, a pentyl group, an isopentyl group, a hexyl group, and a lauryl group. Further, n is an integer of 1 to 40.

Among the substituents represented by the above formula (a),
R ¹ is an alkylene group having 5 carbon atoms such as — (CH ₂ ) ₅ —,
Preferably, R ² is a butyl group and n is 22.
Further, among the substituents represented by the formula (b), R ³ is represented by the following formula:

Embedded image It is preferable that the alkylene group has 2 or 3 carbon atoms, R ⁴ is a methyl group or an ethyl group, and n is an integer of 5 to 8. Further, among the substituents represented by the formula (c), R ⁵ is an alkylene group having 2 or 3 carbon atoms represented by the above-described formula for R ³ , R ⁶ is a lauryl group, and n is 5 to 5. What is an integer of 8 is preferable.

In the modified copolymer, these graft chains may be a propylene / butene copolymer or a propylene / butene copolymer.
It is preferable that 0.3 to 10 are added to one main skeleton molecular chain composed of a butene / ethylene copolymer, and it is particularly preferable that 0.5 to 5 are added.

In order to obtain the modified copolymer having a graft chain, first, the propylene / butene copolymer or the propylene / butene / ethylene copolymer is added to at least one selected from unsaturated carboxylic acids and derivatives thereof.
After the seeds are graft-copolymerized, they can be obtained by reacting compounds represented by the following formulas (A) to (C).

[0022]

Embedded image

In the above formulas (A) to (C), R ^{1 to} R
⁶ and n are as defined for the above formulas (a) to (c).

Examples of unsaturated carboxylic acids and derivatives thereof include acrylic acid, methacrylic acid, maleic acid,
Unsaturated carboxylic acids such as fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid or These derivatives (for example, acid anhydride, acid halide, amide, imide, ester and the like) can be mentioned. These unsaturated carboxylic acids or their derivative monomers are
The species can be used alone or in combination.

These unsaturated carboxylic acids and derivatives thereof are propylene / butene copolymers or propylene / butene copolymers.
It is preferable that the butene / ethylene copolymer is graft-copolymerized at a ratio of 0.5 to 20% by weight, preferably 1 to 15% by weight.

A method for graft-copolymerizing a propylene / butene copolymer or a propylene / butene / ethylene copolymer with at least one kind selected from the above unsaturated carboxylic acids and derivatives thereof (hereinafter, referred to as "graft monomer"). The method is not particularly limited, and various methods can be used. For example, a method of dissolving a propylene / butene copolymer or a propylene / butene / ethylene copolymer in an organic solvent, adding a graft monomer and a radical polymerization initiator, and heating and stirring to cause a graft copolymerization reaction; Butene copolymer or propylene
A method in which a butene-ethylene copolymer is heated and melted, and a graft monomer and a radical polymerization initiator are added to the obtained melt, followed by a graft copolymerization reaction with stirring; propylene-butene copolymer or propylene-butene-ethylene A method in which the copolymer, the graft monomer and the radical polymerization initiator are mixed in advance, and the obtained mixture is supplied to an extruder and graft-copolymerized while being heated and kneaded; a powdery propylene / butene copolymer or propylene / After impregnating the butene / ethylene copolymer with a solution obtained by dissolving the graft monomer and the radical polymerization initiator in an organic solvent, the mixture is heated at a temperature at which the powdered copolymer is not dissolved to cause a graft copolymerization reaction. Methods and the like can be mentioned. Among these methods, a method that does not use an organic solvent is preferable from the viewpoint that the generation of by-products is small and the next reaction can be performed efficiently, but even when an organic solvent is used, the obtained modified The copolymer may be precipitated and washed with a poor solvent to remove by-products.

The reaction temperature is 50 ° C. or higher, especially 80 to 2
The range of 00 ° C. is suitable, and the reaction time is about 2 to 10 hours. The reaction system may be any of a batch system and a continuous system, but a batch system is preferable for performing the graft copolymerization uniformly.

The radical polymerization initiator used in the graft copolymerization reaction may be any one which promotes the reaction between the propylene / butene copolymer or the propylene / butene / ethylene copolymer and the graft monomer. , Is not particularly limited. In particular, organic peroxides and organic peresters are preferred in terms of good graft efficiency.

Specific examples of the radical polymerization initiator include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne- 3,1,4-bis (t
tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butylperacetate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5
-Di (tert-butyl peroxide) hexane, te
tert-butyl benzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, t
Examples thereof include tert-butyl perpiparate, cumyl perpiparate, and tert-butyl perethyl acetate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di (tert-butyl)
Butylperoxy) hexane, 1,4-bis (tert
-Butylperoxyisopropyl) benzene is preferred. The radical polymerization initiator is propylene / butene copolymer or propylene / butene / ethylene copolymer 100
It is preferably used in an amount of about 0.001 to 10 parts by weight with respect to parts by weight.

When an organic solvent is used in the graft copolymerization reaction, the solvent used is not particularly limited. For example, benzene, toluene, aromatic hydrocarbons such as xylene, hexane, heptane, octane, aliphatic hydrocarbons such as decane, cyclohexane, cyclohexene,
Alicyclic hydrocarbons such as methylcyclohexane, aliphatic alcohols such as ethanol and isopropanol, ketone solvents such as acetone, methyl isobutyl ketone and methyl ethyl ketone, and halogenated hydrocarbons such as trichloroethylene, dichloroethylene and chlorobenzene. be able to. These may be used alone or in combination of two or more.

In the present invention, a propylene / butene copolymer or a propylene / butene / ethylene copolymer (hereinafter, referred to as “graft copolymer”) obtained by graft copolymerizing at least one kind selected from the unsaturated carboxylic acids and derivatives thereof. ) Can be reacted with the compounds represented by the formulas (A) to (C) to obtain a modified copolymer.

The compound represented by the formula (A) includes
For example, those produced by adding a ring-opening polymer of a cyclic ester such as ε-caprolactone to alcohol are exemplified. Examples of the compound represented by the formula (B) include aliphatic alcohols. Furthermore, examples of the compound represented by the formula (C) include polyethylene glycol alkyl ether and the like. These compounds represented by formulas (A) to (C) may be used alone or in combination of two or more.

Formula (A) for the above graft copolymer
The reaction amount of the compound represented by the formula (C) is preferably 1 molar equivalent or less, more preferably 0.01 to 0.5 molar equivalent, with respect to the graft monomer grafted on the graft copolymer.

The reaction of the graft copolymer with at least one compound selected from the compounds represented by formulas (A) to (C) may be carried out in the presence or absence of a solvent using a catalyst, or It can be performed without using a catalyst.

When a solvent is used, examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, octane and decane, cyclohexane, cyclohexene and methylcyclohexane. And aliphatic alcohols such as ethanol and isopropanol, and ketone solvents such as acetone, methyl isobutyl ketone and methyl ethyl ketone. These are 1
Species may be used alone or in combination of two or more.

When a catalyst is used, the catalyst used may be, for example, Zn, pb, Co, Ti, Mg, B
a, acetate such as Na, alkoxide, oxide, chloride,
Examples of sulfates and phosphates include acids such as sulfuric acid and p-toluenesulfonic acid, and alkalis such as sodium hydroxide and potassium hydroxide. Among them, zinc acetate, titanium tetrabutoxide, p-toluenesulfonic acid and the like are preferably used.

The reaction temperature is 50 ° C. or higher, especially 80 to 2
The range of 00 ° C. is suitable, and the reaction time is about 2 to 20 hours. The reaction system may be either a batch system or a continuous system, and is not particularly limited, but a batch system is preferable in order to uniformly perform the graft copolymerization.

The primer composition of the present invention is used by dissolving or dispersing the above modified copolymer in an organic solvent. The organic solvent used is not particularly limited, but is preferably an aromatic hydrocarbon, and particularly preferably an alkyl-substituted aromatic hydrocarbon. Specific examples of the alkyl-substituted aromatic hydrocarbon include toluene, xylene, amylbenzene, diamylbenzene, amyltoluene, diphenylethane,
Examples thereof include tetralin, decalin, ethylbenzene, triethylbenzene, cumene, and isopropenyltoluene.

The mixing ratio of the modified copolymer and the organic solvent in the primer composition of the present invention is such that the ratio of the modified copolymer / the organic solvent is 5/95 to 60/40, preferably 1
The ratio is 0/90 to 50/50. If the ratio of the modified copolymer is too low, the thickness of the obtained primer coating film becomes too thin to obtain the desired strength, and coating unevenness may occur. On the other hand, if the ratio of the modified copolymer is too high, the viscosity of the solution becomes high, and the coating workability may be deteriorated.

Further, in addition to the modified copolymer and the organic solvent, the primer composition of the present invention may further comprise, if necessary,
Various stabilizers such as antioxidants, weather resistance stabilizers, heat resistance inhibitors,
Components such as a coloring agent such as an inorganic pigment and an organic pigment, and a conductivity-imparting agent such as carbon black and ferrite may be contained. As the inorganic pigment used, for example, titanium oxide, zinc white, lead white, lead red, cuprous oxide, red iron oxide, iron black,
Cadmium pigments such as cadmium yellow, molybdenum red, silver vermilion, graphite, zinc chromate, chromium oxide, navy blue, carbon black, precipitated barium sulfate, barite powder, ordinary light calcium carbonate, ultrafine calcium carbonate,
Alumina white, white carbon and the like can be mentioned. These may be used alone or in combination of two or more.

The primer composition of the present invention is effective for improving the adhesion of a coating material to a molded product when the surface of a molded product made of an olefin polymer, copolymer or other polymer is applied. It is. In particular, the primer composition of the present invention includes, for example, high-pressure polyethylene, medium-low pressure polyethylene, polypropylene, poly-4-methyl-1-
Α-olefin (co) polymers such as pentene, poly-1-butene and polystyrene, ethylene-propylene copolymer, ethylene-butene copolymer, propylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene
It can be suitably used for coating a molded product made of a (meth) acrylate copolymer or the like.

Further, in addition to the above-mentioned olefin polymer and its copolymer, the primer composition of the present invention may further comprise a molded product comprising polypropylene and synthetic rubber, a polyamide resin, an unsaturated polyester resin, a polybutylene terephthalate resin, Molded products made of various resins or rubbers such as polycarbonate resin and ethylene propylene terpolymer rubber (EPT), for example, molded products such as bumpers for automobiles, and also applied to the surface treatment of steel plates and electrodeposited steel plates. can do. In addition, a polyurethane resin, a fatty acid modified polyester resin, an oil-free polyester resin, a melamine resin, an undercoat on a surface coated with a paint, a primer, an adhesive or the like containing an epoxy resin as a main component,
It can be used to improve the adhesion of paints and the like to the surface and to form a coating film having excellent low-temperature impact resistance and the like.

The molded article to which the primer composition of the present invention is applied is prepared by mixing the above-mentioned various polymers or resins with any of the known molding methods such as injection molding, compression molding, hollow molding, extrusion molding, and rotational molding. Molded by the method described above.

As a method for applying the primer composition of the present invention to the surface of a molded article, spray coating is suitable, and for example, a method of spraying the surface of the molded article with a spray gun can be mentioned. The coating on the molded product may be performed at room temperature. After the coating, the coating may be dried by an appropriate method such as natural drying or forced drying by heating to form a coating film.

As described above, after the primer composition of the present invention is applied to the surface of a molded product and dried, the surface of the molded product is applied to the surface of the molded product by a method such as electrostatic coating, spray coating, or brush coating. Paint can be applied. After the application of the paint, the coating film is cured according to an ordinary method of heating with a nichrome wire, infrared rays, high frequency, or the like, so that a molded article having a desired coating film on the surface can be obtained. The method for curing the coating film is appropriately selected depending on the material and shape of the molded product, the properties of the paint used, and the like.

[0046]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these Examples. In the following, the physical properties of the coating film were evaluated according to the following methods.

Cross-cut test A primer composition is applied, and a top coat is further applied to form a coating film.
In accordance with the grid test method described in No. 0, a test piece is created by cutting the grid. Next, an adhesive tape (Nichiban Co., Ltd., cellophane tape) was attached on the grid of the test piece, and this was immediately pulled in a direction of 90 ° to be peeled, and peeled within 100 grids. The number of grids that have not been checked is counted and used as an index of adhesion.

Peel strength A coating film was prepared on a substrate, a cut was made in a width of 1 cm with a cutter blade until the blade reached the substrate, and the edge was peeled off.
The peeled end is pulled at a speed of 50 mm / min in a direction of 180 ° until the coating film is peeled, and the peel strength is measured.

After the test piece was immersed in water at 40 ° C. for 240 hours, the above-mentioned cross-cut test and measurement of the peel strength were performed.

Storage stability The state of the dispersed particles in the solution was observed with a microscope, and the dispersed particle size at the initial stage and one month later was examined.

(Synthesis Example 1) Capacity 1.0 with stirrer
l in an autoclave, propylene / butene / ethylene copolymer (manufactured by Huls, Bestplast 750, ethylene / propylene / butene: 11/66/23 mol%,
[[Η]: 0.71 dl / g) 96 g, toluene 240
Then, the mixture was heated to 145 ° C. with stirring. Then, 16.2 g of maleic anhydride and 5.6 g of di-t-butyl peroxide were each added in portions over 4 hours, and the mixture was further stirred at 145 ° C. for 2 hours to obtain a copolymer of maleic anhydride graft. A combined solution (hereinafter, referred to as "graft copolymer (A)") was obtained. A large amount of acetone was added to the graft copolymer (A) solution to precipitate the graft copolymer (A), which was then repeatedly washed with acetone.
A graft copolymer (A) was obtained. When the graft amount of maleic anhydride in this graft copolymer (A) was measured, it was 4.8%.

(Synthesis Example 2) Capacity 1.0 with stirrer
l in an autoclave, a propylene / butene / ethylene copolymer (Bestplast 708 manufactured by Huls, ethylene / propylene / butene: 12/68/20 mol%,
[Η]: 0.51 dl / g), and heated to 165 ° C. with stirring. Then, maleic anhydride 1
1.0 g and 2.3 g of di-tert-butyl peroxide
Are added in portions each requiring 1.5 hours, and the mixture is further stirred at 165 ° C. for 1 hour, and thereafter, is grafted with a maleic anhydride (hereinafter referred to as “graft copolymer (B)”).
I got The graft amount of the maleic anhydride in the graft copolymer (B) was measured to be 3.4%. The solution viscosity of the solution adjusted to a solid concentration of 20% by dilution with toluene was E-type viscosity. Was 240 mPa · s.

(Example 1) Capacity of 1.0 equipped with a stirrer
1 g of an autoclave, 71 g of the graft copolymer (A) prepared in Synthesis Example 1, 154 g of dehydrated toluene,
Monomers for graft modification (manufactured by Daicel Chemical Industries, Ltd.
Praxel E1464; C ₄ H ₉ O (C (O) (C
_{H 2) 5 0) 22 H} , butyl alcohol caprolactone adduct) 30 g and p-toluenesulfonic acid 0.89,
g, and heated to 165 ° C. with stirring.
Stirred for hours. After cooling, toluene was added to prepare a modified copolymer solution having a solid content of 20%. The viscosity of this modified copolymer solution was 61 mPa · s in E-type viscosity.
Using this modified copolymer solution as a sample, a coating amount of 70 g / m ² was applied to a polypropylene (X708; manufactured by Grand Polymer Co., Ltd.) square plate whose surface was washed with isopropyl alcohol.
Spray coating was performed so that Next, a top coat (R-278 (white), manufactured by Nippon Bee Chemical Co., Ltd.) is applied to a dry film thickness of 30 μm (100 μm for a grid test and for a peel test) to form a coating film. did. After being left at room temperature for 10 minutes, it was placed in an air oven at 100 ° C. and baked for 30 minutes to prepare a test piece. The test piece was subjected to a grid test, a peel test and a water resistance test. Table 1 shows the results.

Example 2 Capacity 1.0 with Stirrer
l autoclave was charged with 225 g of the graft copolymer (B) solution prepared in Synthesis Example 2, 20 g of the same graft-modifying monomer as used in Example 1, and 0.7 g of zinc acetate. The same reaction was performed. Toluene was added to the resulting modified copolymer solution to adjust the solid content concentration to 20%. The viscosity of this modified copolymer solution was 49 mPa · s in E-type viscosity. Using this modified copolymer solution as a sample, a test piece was prepared in the same manner as in Example 1, and a grid test, a peel test, and a water resistance test were performed.
Table 1 shows the results.

Example 3 As a graft-modifying monomer, polyethylene glycol lauryl ether (in the above formula (C), R ^{5 is} —C ₂ H ₄ —, R ^{6 is a} lauryl group, and n is 5). The reaction was carried out in the same manner as in Example 2 except that 4.9 g of the compound (corresponding to the compound) and 0.9 g of paratoluenesulfonic acid were used, and a modified copolymer solution having a solid content of 20% and a solution viscosity of 90 mPa · s was used. I got Using this as a sample, a test piece was prepared in the same manner as in Example 1, and a grid test, a peel test, and a water resistance test were performed. Table 1 shows the results.

Comparative Example 1 Using the graft copolymer (A) prepared in Synthesis Example 1 as a sample, a test piece was prepared in the same manner as in Example 1, and a cross-cut test, peel test and A water resistance test was performed. Table 1 shows the results.

[0057] Note * Cross cut test; X / 100 * Peel strength; g / cm

(Examples 4 to 6, Comparative Example 2) Examples 1 to 3
The dispersion particle size of the sample of Comparative Example 1 was measured immediately after synthesis and one month later, and was used as a measure of storage stability. Table 2 shows the results.

[0059] Unit: μm

[0060]

EFFECT OF THE INVENTION The primer composition of the present invention can impart good adhesion by coating a polyolefin molded article represented by polypropylene without applying a pretreatment with a chlorine-based organic solvent to the molded article. Moreover, it has excellent storage stability. Further, the modified copolymer of the present invention is suitable as a main component of the primer composition.

Claims (4)

[Claims] 1. A propylene / butene copolymer or a propylene / butene / ethylene copolymer having the following formula (a):
(C): embedded image (In the formula, R ¹ , R ³ and R ⁵ may be the same or different and each is an alkylene group having 2 or more carbon atoms, and R ² , R ⁴
And R ⁶ may be the same or different and have 1 to 4 carbon atoms.
A modified copolymer obtained by adding as a graft chain at least one substituent selected from substituents represented by (0) an alkyl group and n is an integer of 1 to 40), and a primer composition comprising an organic solvent. 2. The primer composition according to claim 1, wherein the mixing ratio of the modified copolymer and the organic solvent is such that the ratio of the modified copolymer / the organic solvent is 5/95 to 60/40. 3. The method according to claim 1, wherein the modified copolymer is obtained by graft copolymerizing at least one selected from unsaturated carboxylic acids and derivatives thereof with a propylene / butene copolymer or a propylene / butene / ethylene copolymer. The following formula (A)
~ (C): embedded image (In the formula, R ¹ , R ³ and R ⁵ may be the same or different and each is an alkylene group having 2 or more carbon atoms, and R ² , R ⁴
And R ⁶ may be the same or different and have 1 to 4 carbon atoms.
The primer composition according to claim 1, wherein the primer composition is obtained by reacting at least one compound selected from 0 alkyl groups, and n is an integer of 1 to 40). 4. After graft copolymerizing at least one selected from unsaturated carboxylic acids and derivatives thereof onto a propylene / butene copolymer or a propylene / butene / ethylene copolymer, the following formulas (A) to (A) C): (In the formula, R ¹ , R ³ and R ⁵ may be the same or different and each is an alkylene group having 2 or more carbon atoms, and R ² , R ⁴
And R ⁶ may be the same or different and have 1 to 4 carbon atoms.
A modified copolymer obtained by reacting at least one compound selected from the group consisting of 0 alkyl groups and n is an integer of 1 to 40).