JPH0987582A - Primer composition and molding with primer layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a primer compsn. which can form a primer layer excellent both in adhesion to a resin substrate and in adhesion to a coating film formed on the primer layer. SOLUTION: This compsn. contains an org. solvent and an oil-sol. polyester having at least two polar groups having hydrogen and heteroatoms in the molecule and a wt. average mol.wt. of 1,000-1,000,000. A molding having a primer layer formed from the compsn. on the surface of a resin substrate and a coated article obtd. from the same are provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a primer composition, and more particularly to a primer composition comprising an oil-soluble polyester that exhibits good adhesion to a resin substrate such as polyolefin. Furthermore, the present invention relates to a molded article in which a layer of the primer composition is formed on the surface of a resin substrate, and a coated molded article in which a coating film is formed on the primer layer surface of such a molded article.

[0002]

2. Description of the Related Art As is well known, hydrocarbon polymers such as polyolefins are widely used because of their excellent physical properties and relatively low price. However, since there are no polar groups in the molecule, the adhesion of coating films It has a problem that the adhesiveness is low and practical adhesive strength cannot be obtained. In order to solve such a problem, it is generally practiced to treat the surface of the base material with a primer to improve the adhesion and adhesion to the surface.

Conventionally, as such a primer, for example, a primer composition containing a styrene / butadiene block copolymer graft-copolymerized with an α, β-unsaturated vinyl monomer having a hydroxyl group as a main component (Japanese Patent Laid-Open No. Hei 10 (1999) -242242) 2-1
No. 10168), and a primer composition mainly composed of a styrene / isoprene block copolymer graft-copolymerized with a monoolefin dicarboxylic acid (JP-A-4-264174). However, in a primer composition containing these modified block copolymers as a main component, a pretreatment such as steam cleaning using a chlorine-based solvent such as trichloroethane is applied to the base material before being applied on the base material. There is a need for improvement from the standpoint of global environmental protection in recent years.

As a primer composition which does not require pretreatment with a chlorine-based solvent, for example, a block copolymer of styrene / vinylisoprene / styrene is graft-copolymerized with an ethylenically unsaturated monomer having a hydroxyl group. There is known a primer composition containing as a main component (JP-A-6-329977). However, this composition has problems such as insufficient anchoring effect to the substrate and insufficient adhesion to the substrate.

[0005]

The object of the present invention is to provide a base material made of a polymer resin having a small polarity such as polyolefin, even if the surface of the base material is not pretreated with a chlorine-based solvent. It is an object of the present invention to provide a primer composition capable of forming a primer layer having excellent adhesion to a material and capable of forming a coating film having excellent adhesion on the surface by coating.

[0006]

According to the present invention, at least two polar groups containing a hydrogen atom and a hetero atom are contained in the molecule.
Having a weight average molecular weight of 1,000 to 1,000,0
A primer composition comprising 00 oil-soluble polyester and an organic solvent is provided. According to the present invention, there is further provided a molded body composed of a resin base material and a primer layer formed on the surface of the base material and comprising the primer composition. According to the present invention, there is further provided a coated molded article comprising a resin base material, a primer layer formed on the surface of the base material and comprising the primer composition, and a coating film formed on the surface of the primer layer. To be done.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Polyester The polyester used in the present invention is characterized by having at least two polar groups containing a hydrogen atom and a hetero atom in the molecule. The polar group is not particularly limited as long as it has at least one hydrogen atom and at least one hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom and the like, and an oxygen atom is preferable. As the polar group having such a hydrogen atom and a hetero atom, for example, a hydroxyl group,
Examples thereof include a carboxyl group, an amino group and a thiol group. Among these, a hydroxyl group and a carboxyl group are preferable, and a hydroxyl group is particularly preferable.

It is necessary that at least two polar groups containing a hydrogen atom and a hetero atom be present in the polyester molecule, and if the number is less than two, the adhesion to paints and the like will be reduced, which is not preferable. The maximum value of the polar group content may be appropriately selected within the range in which the polyester does not become oil-soluble,
There is no particular limitation. Oil-soluble is a property that does not dissolve in water. If the polyester used is not oil-soluble, the effect of anchoring with the base material is poor, and the adhesion is insufficient, which is not preferable.

When the polar group containing a hydrogen atom and a hetero atom is a hydroxyl group or a carboxyl group, its content in the polyester can be represented by a hydroxyl value or an acid value,
The value can be appropriately selected depending on the molecular weight of the polyester, but the sum of the hydroxyl value and the acid value is usually 10 to 200 mg.
KOH / g, preferably 20-150 mg KOH / g,
More preferably, it is in the range of 30 to 100 mgKOH / g.

The molecular weight of the polyester is 1,000 to 1,000 in terms of polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC).
1,000,000, preferably 2,000-500,
000, more preferably 3,000 to 100,000. Even if the molecular weight of polyester is too small or too large, the anchor effect to the substrate is not sufficient, and the adhesion and peel strength are poor, which is not preferable.

The method for producing the polyester of the present invention is not particularly limited. For example, (A) divalent higher carboxylic acid component, (B) divalent alcohol component, and (C) trivalent or higher carboxylic acid, At least one polyvalent component having a valence of 3 or more selected from an alcohol having a valence of 2 or more and an epoxy compound having two or more epoxy groups, and 1 component of the (C) component relative to the total amount of the (A) and (B) components. It can be obtained by polycondensation at a ratio of -80 mol%.

As the divalent higher carboxylic acid (A), those having 8 or more carbon atoms, preferably 10 to 200 carbon atoms, and more preferably 20 to 80 carbon atoms are used. When the number of carbon atoms in the carboxylic acid is within this range, the anchor effect with the substrate, the adhesion strength, etc. are sufficiently high, which is preferable.

The divalent higher carboxylic acid may be, for example, linear, branched, cyclic or aromatic, and specifically, suberic acid, azelaic acid, terephthalic acid and isophthalic acid. Acid, methyl isophthalic acid, sebacic acid, brassic acid, polyalkylene succinic acid,
Examples include polymerized fatty acid dimer acid, and among these, at least one selected from polyalkylene succinic acid and polymerized fatty acid dimer acid is preferable,
Dimer acid of polymerized fatty acid is particularly preferable.

The polymerized fatty acid is obtained by polymerizing a higher fatty acid, and usually has 8 to 24 carbon atoms, preferably 16 to 2 carbon atoms.
It is a generic term for polymerized acids obtained by polymerizing an aliphatic having 0 saturated or at least one unsaturated bond or an aliphatic ester derivative thereof. Commercially available polymerized fatty acids are those obtained by polymerizing oleic acid, linoleic acid, ricinoleic acid, eleostearic acid, etc., containing dimer acid as the main component, and polymer acid and monomer acid of trimer acid or more as sub-components. Is what you are doing. The structural analysis of polymerized fatty acids is described in D.S. H. McMahon et al. (J. Am. Oil. Chem. Soc., 5
1 , 522 (1974)). The polymerization product can be separated into polymerized fatty acids having different contents of each component by a distillation method or a solvent extraction method. Further, hydrogenated polymerized fatty acids having good thermal oxidation stability can be obtained by hydrogenating the unsaturated carbon-carbon bonds remaining in these polymerized fatty acids. In the present invention, unpurified polymerized fatty acid, purified polymerized fatty acid or hydrogenated polymerized fatty acid can also be used, and preferably purified polymerized fatty acid containing 60% by weight or more of a dimer acid component or a hydride thereof is used.

The polyalkylene succinic acid has the general formula (1)

Embedded image (R ¹ in the formula is a polymer chain of lower alkylene.)
It is represented by R ¹ is a polymer chain of lower alkylene, and preferably the lower alkylene is at least one selected from ethylene, propylene and butylene. The degree of polymerization of polyalkylene succinic acid is preferably 10 to 300.
Range.

The dihydric alcohol (B) is not particularly limited as long as it is one generally used in the polyester synthesis reaction, and examples thereof include alkanediols, cycloalkanediols, polyoxyalkylene glycols and ester diols. And hindered glycols. Among these, alkane diol and hindered glycol are preferable, and hindered glycol is particularly preferable. These can be used alone or in combination of two or more.

Examples of the alkanediols include ethylene glycol, propylene glycol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1 , 8-octanediol, 1,9-nonanediol and the like. Among these, 1,6-hexanediol, 3-methyl-1,5-pentanediol,
Alkanediols having 6 to 9 carbon atoms such as 1,8-octanediol and 1,9-nonanediol are preferable.

Cycloalkanediols include cyclopentane-1,2-diol, cyclohexane-1,
2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclohexane-
Examples include 1,4-dimethanol and cyclooctane-1,4-diol.

Examples of the polyoxyalkylene glycols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol and polybutylene obtained by polymerizing alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide alone or in a mixture by a known method. glycol, and the like, for example, the general formula (2) HO - is I represented by ^{_{((CH 2) m -CHR 2}} O) n -H (2). Here, R ² represents a hydrogen atom or a lower alkyl group such as a methyl group or an ethyl group, and preferably a hydrogen atom. m represents an integer of 1 to 6, and preferably an integer of 1 to 4. n represents an integer of 2 to 1,000, preferably 5 to 500, more preferably 10 to 10.
It is an integer of 0.

Examples of the ester diols include β-propiolactone, β-butyrolactone, γ-butyrolactone, which are disclosed in JP-A-6-116372.
Lactones such as δ-valerolactone and ethylene glycol, diethylene glycol, triethylene glycol,
Opening products of (poly) alkylene glycol such as tetraethylene glycol and the like, for example, represented by the general formula ^{(3) HO- (R 3 -COO} -G) p -H (3). Here, R < ³ > shows a C2-C6 alkylene group. p represents an integer of 2 to 1,000, preferably 5 to 500, and more preferably 10 to 100. G ^{_{is, - (CH 2 CHR 4 O}} ) q - represents a group, q is an integer of 1 to 4 in the formula, R ⁴ represents a lower alkyl group such as a hydrogen atom or a methyl group.

As the hindered glycol, for example,
Formula _{(4) HOCH 2 -C (R} 5 R 6) include those represented by -CH ₂ OH (4). Here, R ⁵ and R ⁶ represent an alkyl group. The carbon number of the alkyl group is not particularly limited, but is usually 1 to 50, preferably 1 to 20, and more preferably 2 to 10. Specific examples of such hindered glycols include 2,2-dimethyl-
1,3-propanediol, 2,2-diethyl-1,3
-Propanediol, 2,2-dipropyl-1,3-propanediol, 2,2-diisopropyl-1,3-propanediol, 2,2-diisobutyl-1,3-propanediol, 2-methyl-2-dodecyl -1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-propyl-2-pentyl-1,3
-Propanediol and the like.

In the present invention, in addition to the divalent higher carboxylic acid component (A) and the dihydric alcohol component (B), two or more trivalent or more carboxylic acids, trivalent or more alcohols and epoxy groups are used. At least one (C) selected from the epoxy compounds having is used.

The trivalent or higher carboxylic acid is not particularly limited as long as it has three or more carboxyl groups, but a trivalent carboxylic acid is usually used. Specific examples of trivalent or higher carboxylic acids include, for example, trimellitic acid, tricarballylic acid, camphoronic acid, trimesic acid,
Examples include polymerized fatty acid trimer acid. Of these, trimesic acid and polymerized fatty acid trimeric acid are preferable, and polymerized fatty acid trimeric acid is particularly preferable.

The trihydric or higher alcohol is not particularly limited as long as it has three or more hydroxyl groups. Specific examples of trihydric or higher alcohols include, for example,
Examples thereof include glycerin, sorbitol, glucose, mannitol, sucrose, glucose and the like.

As the trihydric or higher alcohol, a trihydric or higher hindered alcohol represented by the general formula (5) HOCH ₂ —C (R ⁷ R ⁸ ) —CH ₂ OH (5) can be used. . In the formula, R ⁷ and R ⁸ each independently represent an alkyl group or an alkyl group having a hydroxyl group, and at least one of R ⁷ and R ⁸ is an alkyl group having a hydroxyl group. Here, the carbon number of the alkyl group is
Although not particularly limited, it is usually 1 to 50, preferably 1 to 2.
The number is 0, and more preferably 2 to 10. Specific examples of the trihydric or higher hindered alcohol include, for example,
Examples thereof include trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, and dipentaerythritol.

These trihydric or higher alcohols may be used alone or in admixture of two or more, and the trihydric or higher alcohol component contains at least 10 mol% of the trihydric or higher hindered alcohol. , Preferably 3
0 to 100 mol%, more preferably 50 to 100 mol%
Those containing are preferable.

The epoxy compound having two or more epoxy groups is not particularly limited as long as it is a compound having at least two epoxy groups in the molecule, and examples thereof include dimer acid glycidyl ester of polymerized fatty acid and glycidyl ether of bisphenol A. , Glycidyl ether of bisphenol F, glycidyl ether of aliphatic dibasic acid, and the like.

The component (C) may be used either alone or as a mixture of two or more thereof, and the amounts thereof are such that the divalent carboxylic acid component (A) and the divalent alcohol component (B) are used. 1) to 80 mol%, preferably 5 to 60 mol%, and more preferably 10 to 40 mol%, based on the total amount of). If the amount of component (C) used is too small, the hydroxyl value or acid value will not be sufficient, and if it is too large, control of the polycondensation reaction will be difficult, and neither is preferred.

Further, as long as the object of the present invention is not impaired, the divalent higher carboxylic acid (A) is contained in the carboxylic acid component.
And a carboxylic acid component having three or more valences (C), other carboxylic acids such as succinic acid, glutaric acid, adipic acid,
Divalent lower carboxylic acids such as maleic acid, itaconic acid, pimelic acid, methylmalonic acid, dimethylmalonic acid; formic acid, acetic acid, butyric acid, 2-methylpropanoic acid, valeric acid, isooctylic acid, isononanoic acid, lauric acid, myristic acid , Palmitic acid, stearic acid, isostearic acid,
Monovalent carboxylic acids such as arachidic acid, linoleic acid, oleic acid, and elaidic acid, and other alcohols in addition to the divalent alcohol component (B) and the trivalent or higher alcohol component (C) in the alcohol component, For example, methanol, ethanol, isopropanol, butanol, neopentyl alcohol, 3-methyl-3-pentanol,
A monohydric alcohol such as 3-ethyl-3-pentanol, 2,3,3-trimethyl-2-butanol, 1-decanol or nonyl alcohol may be used in combination. Generally, the permissible amount is 30 mol% or less in the total carboxylic acid component or the total alcohol component.

The ratio of the carboxylic acid component and the alcohol component may be appropriately selected according to the desired molecular weight or hydroxyl value (or acid value) of the polyester, but OH / C
The OOH (equivalent) ratio is usually 0.5 to 2.0, preferably 0.6 to 1.5.

The polyester used in the present invention can be obtained by polycondensation reaction of the above-mentioned component (A), component (B), component (C) and other optional carboxylic acid and alcohol components. The polycondensation reaction may be carried out according to a conventional method, for example, at a reaction temperature of 100 to 300 ° C, preferably 150 to 280 ° C, and particularly preferably in the presence of an inert gas. If necessary, a water-insoluble organic solvent that is azeotropic with water such as toluene or xylene may be used, or the reaction may be performed under reduced pressure. Further, at the time of esterification polycondensation reaction, usually, as an esterification catalyst, paratoluenesulfonic acid, sulfuric acid, boron trifluoride complex, phosphoric acid, hydrochloric acid, potassium acetate, zinc stearate,
Various metal oxides such as zinc, titanium, tin and butyltin oxide, and titanium oxide are used, but it is preferable to use the metal oxide from the viewpoint of the oxidation resistance stability of the obtained polyester.

Primer Composition A primer composition containing the polyester of the present invention as an active ingredient contains an organic solvent together with the oil-soluble polyester. The organic solvent is not particularly limited as long as it is commonly used, and examples thereof include aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane, heptane, octane and decane; cyclo. Alicyclic hydrocarbons such as pentane, cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, trimethylcyclopentane, and cyclooctane; alcohols such as ethanol and isopropyl alcohol; esters such as ethyl acetate and butyl acetate; acetone and methyl ethyl ketone , Methyl isobutyl ketone, and other ketones. Among these, aromatic hydrocarbons, alicyclic hydrocarbons, esters, ketones and the like are preferable, and aromatic hydrocarbons are particularly preferable.

These organic solvents are used alone or in combination of two or more, and the amount thereof is usually 10 to 10,000 per 100 parts by weight of polyester.
The proportion is 0 parts by weight, preferably 50 to 5,000 parts by weight, more preferably 100 to 1,000 parts by weight. When the amount of the organic solvent used is in the above range, workability and coating film stability are excellent and suitable.

A binder resin may be added to the primer composition of the present invention in order to further improve the adhesion of paints and inks. As a binder resin,
Although not particularly limited, for example, homopolymers of α-olefins such as high-pressure polyethylene, medium- and low-pressure polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and chlorinated products thereof; ethylene / propylene Copolymer, ethylene / 1-butene copolymer, ethylene / propylene / diene copolymer, propylene / 1-
Copolymers containing .alpha.-olefin component as a main component such as butene copolymer, propylene.4-methyl-1-pentene copolymer, chlorinated product thereof and acrylic acid, maleic acid and its anhydride in the polymer. Graft copolymerization modified olefin copolymer obtained by graft-copolymerizing α, β-unsaturated polar compound components such as; acrylic acid, maleic acid and their anhydrides in the polymer containing the α-olefin component as a main component Block copolymer modified olefin copolymer obtained by block copolymerizing α, β-unsaturated polar compound components such as ethylene; acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / crotonic acid copolymer , Ethylene-maleic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-vinyl acetate copolymer, etc. Olefin-based resin such as random copolymer containing fin component as a main component; polystyrene, impact-resistant polystyrene, styrene-acrylonitrile copolymer, styrene-alkyl (meth) acrylate copolymer, ABS resin, MBS resin, AAS resin Styrene-based polymers such as styrene-modified polyphenylene ether, styrene-butadiene block copolymer, styrene-isoprene block copolymer and hydrides thereof; epoxy resin; styrene-butadiene rubber, butyl rubber, ethylene-propylene copolymer Rubber, synthetic rubber such as ethylene-propylene-diene copolymer rubber, and the like can be used. Of these, α-olefin-based (co) polymers and chlorinated products thereof are preferable.

These binder resins may be used either individually or in combination of two or more, and the amount used is usually 10 to 150 parts by weight, relative to 100 parts by weight of the polyester of the present invention. Preferably 20-100
Parts by weight, more preferably 30 to 70 parts by weight.

Further, other additives can be added to the primer composition of the present invention, if necessary.
Other additives are not particularly limited, and examples thereof include various stabilizers such as antioxidants, weather resistance stabilizers, heat resistance inhibitors, ultraviolet light stabilizers, ultraviolet light stabilizers; titanium oxide, zinc white, lead white, lead tin oxide. , Inorganic pigments such as cuprous oxide, iron black, cadmium yellow, molybdenum red, silver vermilion, yellow lead, chromium oxide, navy blue, carbon black, barium sulfate, alumina white, and white carbon; coloring agents such as organic pigments; such as ferrite Conductivity imparting agent; calcium carbonate, calcium oxide, magnesium oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, calcium silicate, magnesium silicate, calcium sulfate, barium sulfate, calcium sulfite, mica, dolomite, Silica, clay, talc, carbon black, zinc oxide, glass Inorganic fillers such as fibers; organic active halogen compounds such as halogenated succinimide, halogenated isocyanuric acid, halogenated hydantoin; reinforcing agents, plasticizers, antistatic agents, nucleating agents, flame retardants, various additives such as oils, etc. These may be added alone or in combination. The addition amount of these is appropriately determined within a range that does not impair the effects of the present invention.

Substrate The primer composition of the present invention is effective for improving the adhesion of the coating material to the surface of various resin substrates. Examples of the resin substrate include various polymers that are non-elastomeric,
As these, any molded body molded by a known molding method such as injection molding, hollow molding, extrusion molding, compression molding, and rotational molding is usually used. Further, it may be a base material having a resin coating layer formed on the surface of a molded body of metal or other inorganic material. The polymer constituting the base material itself or the surface coating layer is not particularly limited, and examples thereof include a thermoplastic resin and a thermosetting resin. Among these, the thermoplastic resin is preferable.

As the thermoplastic resin, for example, polyolefin resin, styrene resin, ionomer resin, isobutylene-maleic anhydride copolymer, polymethylmethacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, fluororesin, Examples thereof include polyamide and polyphenylene ether. Among these, hydrocarbon-based thermoplastic resins such as polyolefin-based resins and styrene-based resins are particularly preferable.

Examples of the olefin resin include homopolymers of α-olefins such as polyethylene, polypropylene, poly-1-butene and poly-4-methyl-1-pentene; ethylene / propylene copolymers and ethylene / 1-butene. Copolymer, ethylene / propylene / diene copolymer, propylene / 1-butene copolymer, propylene / 4
A copolymer containing an α-olefin component such as a methyl-1-pentene copolymer as a main component and an α-olefin such as acrylic acid or maleic acid or its anhydride,
Graft copolymerization modified olefin copolymer obtained by graft-copolymerizing β-unsaturated polar compound component; α, β such as acrylic acid, maleic acid or anhydride thereof in the polymer containing the α-olefin component as a main component Block copolymer modified olefin copolymer obtained by block copolymerizing an unsaturated polar compound component; further, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / crotonic acid copolymer, ethylene / malein Examples thereof include random copolymers containing an α-olefin component as a main component, such as acid copolymers, ethylene / methyl acrylate copolymers, and ethylene / vinyl acetate copolymers. In addition, these olefin-based resins are blended with a small amount of a thermoplastic elastomer such as ethylene-propylene copolymer rubber or ethylene-propylene-diene terpolymer rubber unless the characteristics of the resin are impaired. Good.

Examples of the styrene resin include polystyrene, high impact polystyrene, AS resin, ABS resin, AAS resin, ACS resin, MBS resin, styrene-modified polyphenylene ether, resinous block polymer such as styrene-butadiene and styrene-isoprene, and the like. And a partial hydride thereof. Of these, polystyrene, high impact polystyrene and ABS resin are preferable.

Specific preferred examples of the molded article obtained by forming the primer layer of the primer composition of the present invention on the surface of various resin substrates as described above include polyolefin such as polypropylene, or polyolefin and 30% by weight or less. Molded products such as automobile bumpers made of synthetic rubber of S, such as unsaturated polyester resin and epoxy resin
Examples include MC molded products, RIM molded products of polyurethane resin and dicyclopentadiene resin, and cationic electrodeposition coated steel sheets.

The resin base material to which the primer composition of the present invention is applied includes inorganic fillers such as talc, zinc white, glass fiber, titanium white and calcium carbonate; antioxidants, ultraviolet absorbers, hydrochloric acid absorbers and the like. Various stabilizers; pigments and the like may be contained.

Molded Product A molded product containing the primer layer of the present invention is formed by applying the primer composition on the surface of a resin substrate and drying the primer composition to form a primer layer on the surface of the substrate, and then applying a paint on the surface. It is manufactured by

The primer composition may be applied to the surface of the resin substrate according to a conventional method. For example, the primer composition may be applied by a method such as brush coating, dipping, spraying, spin coating or roll coater, and a solvent may be applied. It can be volatilized. The coating may be performed at room temperature. After the coating, the coating is dried by an appropriate method such as natural drying or forced drying by heating to form a coating film.

The coating amount is such that the thickness of the primer layer from which the solvent has been removed is 0.1 to 100 μm, preferably 0.5 to 50 μm.
m, more preferably 1 to 30 μm,
The adhesiveness between the resin base material and the paint is sufficiently high, which is preferable.

The paint applied to the surface of the primer layer is not particularly limited, but examples thereof include solvent-type thermosetting acrylic resin paint, polyurethane resin paint, melamine resin paint, epoxy resin paint, alkyd melamine resin paint,
Acrylic-modified alkyd resin paints and the like are suitable.

The coating of the paint on the surface of the primer layer can be carried out by a conventional method, for example, electrostatic coating, spray coating,
A method such as brush painting may be used. The application of the paint may be performed by a method of applying an undercoat and then applying an overcoat. After applying the paint, a method of heating and curing the coating film with nichrome wire, infrared rays, high frequency, etc. is adopted,
The method is appropriately selected depending on the material and shape of the surface of the base material, the properties of the coating material used, and the like.

[0048]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Parts and percentages in these examples are on a weight basis unless otherwise specified.

The physical properties were measured according to the following methods. (1) Weight average molecular weight The weight average molecular weight of the polyester is determined according to the GPC method.
It was measured as a standard polystyrene equivalent amount. (2) Hydroxyl Value and Acid Value The hydroxyl value and acid value of the polyester were measured according to the following described in "Standard oil and fat analysis test method" (Japan Oil Chemistry Association). Hydroxyl value 2,4,9,2-83 Acid value 2,4,1-83 (3) Adhesion test Cross-cut test: A cross-cut is made according to the method of the cross-cut test described in JIS K5400. After making a test piece and sticking cellophane (manufactured by Nichiban Co., Ltd.) on the grid, it is quickly pulled in a 90 ° direction to be peeled off,
The number of crosses that were not peeled out of the 100 crosses was evaluated. Peel strength test: A coating film formed on the surface of a resin base material is cut with a cutter blade into a 1 cm width until the blade reaches the base material and the end is peeled off, and then the end of the peeled coating film The part was pulled in the direction of 180 ° at a speed of 50 cm / min to determine the peel strength (g / cm).

Example 1 (Preparation of Primer Composition) A 1000 cc four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water diversion tube, and a nitrogen gas inlet tube was charged with hydrogenated polymerized fatty acid (acid value 195 mgKOH / g, monomer acid 0.
3%, dimer acid 97.0%, trimer acid 2.7%; Haridimer 300, manufactured by Harima Kasei Co., Ltd. 182.0 g, polymerized fatty acid (acid value 186 mg KOH / g, dimer acid 2)
7.1%, trimeric acid 72.9%; halidimer 50
0, manufactured by Harima Kasei Co., Ltd.) 410.0 g, 2-ethyl-2-
156.0 g of butyl-1,3-propanediol and 0.26 g of monobutyltin oxide as a catalyst were charged. (COOH / OH = 1.40 (equivalent ratio))

Stirring is carried out while introducing nitrogen gas, and 10
The temperature was raised to 0 ° C. Subsequently, while removing water and unreacted diol generated during the reaction, the temperature is changed from 100 ° C. to 260 ° C.
The temperature was raised to 6 ° C over 6 hours. After that, the reaction was continued for 10 hours while dehydrating at 260 ° C. The obtained polyester 1 has a weight average molecular weight of 8,900 and an acid value of 41.4 m.
It had a gKOH / g and a hydroxyl value of 0.8 mgKOH / g.

100 parts by weight of the obtained polyester and 50 parts by weight of Epoxy resin Epicoat 828 (manufactured by Shell Chemical Co., Ltd.) were dissolved in 600 parts by weight of toluene to prepare a primer composition 1 having a polyester content of 25% by weight.

Example 2 (Preparation of Primer Composition) A 1000 cc four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water diversion tube and a nitrogen gas inlet tube was charged with polymerized fatty acid (acid value 195 mgKOH / g, Monomer acid 0.5
%, Dimer acid 97.0%, trimer acid 2.5%; Haridimer 300, manufactured by Harima Kasei Co., Ltd.) 460.0 g, 2,
4-dimethyl-1,3-propanediol 49.8 g,
64.1 g of trimethylolpropane and 0.26 g of monobutyltin oxide as a catalyst were charged. (OH
/COOH=1.20 (equivalent ratio))

Stirring is performed while introducing nitrogen gas, and 10
The temperature was raised to 0 ° C. Subsequently, while removing water and unreacted diol generated during the reaction, the temperature is changed from 100 ° C. to 260 ° C.
The temperature was raised to 6 ° C over 6 hours. After that, the reaction was continued for 10 hours while dehydrating at 260 ° C. The obtained polyester 2 has a weight average molecular weight of 5,700 and an acid value of 0.1 mg.
The KOH / g and the hydroxyl value were 65 mgKOH / g.

100 parts by weight of the obtained polyester and 50 parts by weight of chlorinated polypropylene (chlorination rate 25%) were dissolved in 600 parts by weight of toluene to give a polyester content of 2
5% by weight of Primer Composition 2 was prepared.

Examples 3 and 4 (Coated Molded Articles) Each of the primer compositions 1 and 2 was polypropylene (SK71) whose surface was wiped with isopropyl alcohol.
2; Showa Denko KK) spray coating to a dry film thickness of 15 μm, and then topcoat paint Soflex No20
0 white (manufactured by Kansai Paint Co., Ltd.) was applied to give a dry film thickness of 60 μm. After leaving it at room temperature for 10 minutes, it was baked in an oven at 100 ° C. for 30 minutes. Using this as a sample, a cross-cut test and a peel strength test were performed. Table 1 shows the results
Shown in

Examples 5 and 6 (Coating Molded Articles) Each of the primer compositions 1 and 2 was polypropylene (SK71) whose surface was wiped with isopropyl alcohol.
2; Showa Denko Co., Ltd.) was spray-coated to a dry film thickness of 15 μm, and then topcoat paint R-271 (Nippon Bee Chemical Co., Ltd.) was applied to a dry film thickness of 60 μm. Let stand at room temperature for 10 minutes, then in an oven at 85 ° C for 30 minutes.
Bake for a minute. Using this as a sample, a cross-cut test and a peel strength test were performed. The results are shown in Table 1.

Comparative Example 1 In accordance with the method disclosed in JP-A-6-329977, 2-hydroxypropyl acrylate was added to hydrogenated Hybrer HVS-3 (manufactured by Kuraray Co.) of a styrene-vinyl isoprene-styrene triblock copolymer. A coating film was prepared in the same manner as in Example 3 using the primer composition 3 in which 150 parts by weight of the modified polymer grafted with 6.3% by weight was dissolved in 850 parts by weight of toluene, and a cross-cut test and a peel strength test were performed. . The results are shown in Table 1.

[0059]

[Table 1]

As shown in Table 1, a coated article having a primer layer comprising the primer composition of the present invention formed on the surface of a polyolefin substrate and having a coating film formed thereon has a conventional primer composition. Compared to the case of using (Comparative Example 1), it is superior in both the cross-cut test and the peel strength test. Thus, even if the surface of the polyolefin substrate is not pretreated with a chlorine-based solvent, the primer composition of the present invention has excellent adhesion to the substrate, and further, adhesion to the coating film formed thereon. Is also excellent.

Preferred Embodiments of the Invention The primer composition of the present invention (claims 1 and 2), a molded product having a primer layer comprising the primer composition (claim 3) and a coated product of the molded product (claim 4) The preferred embodiments of are summarized below. (1) The polar group containing a hydrogen atom is selected from a hydroxyl group, a carboxyl group, an amino group and a thiol group, more preferably a hydroxyl group and a carboxyl group, and further preferably a hydroxyl group. (2) The sum of the acid value and the hydroxyl value of the polyester is 10 to 20.
0 mgKOH / g, more preferably 20-150 mgK
OH / g, most preferably 30-100 mg KOH / g
Range. (3) The molecular weight of the polyester is a polystyrene-converted weight average molecular weight (Mw) measured by gel permeation chromatography (GPC), preferably 2,000.
0 to 500,000, more preferably 3,000 to 10
It is in the range of 0000.

(4) The polyester has (A) a divalent higher carboxylic acid component and (B) a divalent alcohol component, and (C) a trivalent or higher carboxylic acid, a trivalent or higher alcohol and two epoxy groups. At least one compound selected from the epoxy compounds having the above (A), in a proportion of 1 to 80 mol% with respect to the total amount of both components (B),
It is obtained by polycondensation of the three components (A), (B) and (C).

(5) The divalent higher carboxylic acid (A) used for producing the polyester of the above (4) has 8 or more, more preferably 10 to 200, and most preferably 20 to 80 carbons. (6) The divalent higher carboxylic acid (A) of the above item (5) is selected from polyalkylene succinic acid and dimer acid of polymerized fatty acid, and more preferably dimer acid of polymerized fatty acid.

(7) The dihydric alcohol (B) used in the production of the polyester of the above (4) is selected from alkanediol, cycloalkanediol, polyoxyalkylene glycol, ester diol and hindered glycol, and more preferably Is alkane diol or hindered glycol.

(8) The trivalent or higher carboxylic acid (C) used in the production of the polyester of the above (4) is trimellitic acid,
It is selected from among tricarballylic acid, camphoronic acid, trimesic acid and trimeric acid of polymerized fatty acid, more preferably selected from trimesic acid and trimeric acid of polymerized fatty acid, and most preferably trimeric acid of polymerized fatty acid.

(9) The trihydric or higher alcohol (C) used in the production of the polyester of the above item (4) is represented by the following general formula (5).
At least 10 mol%, more preferably 30 to 100 mol%, and most preferably 50 to 100 mol% of a hindered alcohol represented by HOCH in _{^{2 -C (CR 7 R 8)}} -CH 2 OH (5) formula, R ^7, R ⁸ is an alkyl group having an alkyl group or a hydroxyl group, at least one of the two alkyl groups having hydroxyl groups Is.

(10) A dimer acid glycidyl ester of a polymerized fatty acid, wherein the epoxy compound (C) having two or more epoxy groups used in the production of the polyester of (4) above is a polymerized fatty acid.
It is selected from glycidyl ether of bisphenol A, glycidyl ether of bisphenol F and glycidyl ether of aliphatic dibasic acid. (11) The amount of the component (C) used in the production of the polyester of the above (4) is 1 to 80 mol% based on the total amount of the divalent carboxylic acid component (A) and the divalent alcohol component (B) It is more preferably 5 to 60 mol%, still more preferably 10 to 40 mol%.

(12) The organic solvent is at least one selected from aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, alcohols and ketones. (13) The amount of the organic solvent is usually 10 to 10,000 parts by weight, preferably 50, relative to 100 parts by weight of polyester.
To 5,000 parts by weight, more preferably 100 to 1,000
The ratio is 0 part by weight.

(14) The primer composition further comprises 10 to 150 parts by weight, preferably 20 to 100 parts by weight, and more preferably 30 to 1,000 parts by weight of a binder resin based on 100 parts by weight of polyester. Including.

(15) The binder resin of (14) above is a homopolymer of α-olefin, a copolymer containing an α-olefin component as a main component, and an α, β-unsaturated polar compound component in the polymer. Graft copolymerized modified olefin copolymer obtained by graft copolymerizing the above, and block copolymer modified olefin copolymer obtained by block copolymerizing the α, β-unsaturated polar compound component with the polymer containing the α-olefin component as a main component. It is at least one selected from an olefin resin selected from a polymer and a random copolymer having an α-olefin component as a main component; a styrene polymer; an epoxy resin; and a synthetic rubber.

(16) The resin base material is preferably a thermoplastic resin, more preferably a hydrocarbon-based thermoplastic resin, further preferably an olefin-based resin or a styrene-based resin, or a surface coating layer made of the resin. Have. (17) The thickness of the primer layer is 0.1 to 100 μm, more preferably 0.5 to 50 μm, and further preferably 1 to
It is 30 μm. (18) A paint whose coating film formed on the surface of the primer layer is selected from thermosetting acrylic resin paints, polyurethane resin paints, melamine resin paints, epoxy resin paints, alkyd melamine resin paints and acrylic modified alkyd resin paints. Consists of.

[0072]

EFFECTS OF THE INVENTION The primer composition of the present invention can greatly improve the adhesion between various resin substrates and various coating materials. In particular, even a base material made of a resin having a small polarity such as polyolefin can improve the adhesiveness with a coating material without pretreatment with a chlorine-based solvent. Further, the primer composition of the present invention has an effect of improving adhesiveness and printability in addition to the use as the above-mentioned coating primer, and can widely improve the surface characteristics of the resin substrate. Therefore, the primer composition of the present invention is useful as a container for electrical, electronic, automobile and other parts, packaging materials and beverages, cosmetics and the like by utilizing these characteristics, and particularly, audio cassettes and video cassettes. , TV parts, fans for coolers, fans for electric fans, housings for electrical equipment, paper storage cases for copying machines, duct cases for vacuum cleaners, flexible hoses for vacuum cleaners, IC card cases, floppy disk cases, costume cases Cases, etc., car interior materials such as instrument panels, bumpers, side protect panels, rear spoilers,
Surface modification of automobile exterior materials such as side air dams, door mirrors, foil covers, laminated paper packaging materials, film packaging materials for electrical and electronic parts, blow bottles for cosmetics, blow bottles for seasonings, tubular containers, cup-shaped containers, etc. Suitable for quality applications.

Claims (4)

[Claims] 1. A weight average molecular weight of 1,0 having at least two polar groups containing a hydrogen atom and a hetero atom in the molecule.
A primer composition comprising 0 to 1,000,000 oil-soluble polyester and an organic solvent. 2. The primer composition according to claim 1, wherein the sum of the acid value and the hydroxyl value of the polyester is 10 to 200 mgKOH / g. 3. A molded article composed of a resin base material and a primer layer formed on the surface of the base material, the primer layer comprising the primer composition according to claim 1. 4. A resin base material, a primer layer formed on the surface of the base material, the primer layer comprising the primer composition according to claim 1 or 2, and a coating film formed on the surface of the primer layer. Molded body.