JP2018178043A - Coating composition for resin moldings - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating agent to be applied to a polyolefin resin molded article (in particular, a can for gasoline), which has sufficient gloss, hot water resistance, volatile oil resistance, acid resistance, alkali resistance, gasoline resistance, and human Provided is a coating composition capable of obtaining a coating film having improved storage stability under extremely low temperatures in a living environment.
[Solution] The following a. ~ C. Containing the components of a. (Meth) acrylic resin containing a monomer component having a long chain alkyl group as a constituting monomer unit, having a glass transition temperature (Tg) of 35 ° C. to 70 ° C., and having a hydroxyl value of 12 to 42 mg KOH / g b. (Meth) acrylic-modified chlorinated polyolefin resin, c. A polyisocyanate compound, and b. The content of the (meth) acrylic-modified chlorinated polyolefin resin is the same as in the above a. The coating composition which is 10-30 mass parts with respect to 100 mass parts of (meth) acrylic resins.
【Selection chart】 None

Description

  The present invention relates to a coating composition for a resin molded product, and a polyolefin resin molded product having the coating composition coated on the surface.

For example, as described in Patent Document 1,
(A) Chlorinated polyolefin resin having a chlorine content of 10 to 50% by mass,
(B) acrylic modified chlorinated polyolefin resin,
(C) Acrylic resin and / or polyester resin having a weight average molecular weight of 2,000 to 50,000 and a hydroxyl value of 10 to 90 mg KOH / g, and (D) an isocyanate compound as essential components,
The ratio of isocyanate equivalent to hydroxyl equivalent is [isocyanate equivalent] / [hydroxy equivalent] = 0.5 / 1.0 to 1.2 / 1.0,
(A) component, (B) component, (C) component 3 to 20 mass% of the component (A) and 5 to 40 mass% of the component (B) in the total mass (solid content) of the component (C) component Two-component coating compositions having good adhesion to polyolefin materials characterized in that 40 to 92% by mass are known.
The two-component coating composition is considered to be further excellent in glossiness, solvent resistance, accelerated weathering resistance, and storage stability relative to a polyolefin material.

JP, 2005-139336, A

The above-mentioned known two-component coating composition is excellent in that a coating film having good adhesion can be formed with one coat without subjecting a polyolefin material to a primer treatment, but it is still a sufficiently glossy coating. It was not possible to obtain a membrane. Furthermore, the hot water resistance, the volatile oil resistance, the acid resistance, the alkali resistance, the gasoline resistance, and the storage stability under cryogenic temperatures in the living environment of human beings were insufficient.
Therefore, it has been practically difficult to use the above-mentioned known two-pack paint composition in a wider range of environment and / or to form a coating layer as the top layer.

The present invention, which can solve the above problems, is the following coating composition.
1. The following a. ~ C. Contains the ingredients of
a. Containing a monomer component having a long chain alkyl group as a constituting monomer unit, having a glass transition temperature (Tg) of 35 ° C. to 70 ° C., and a hydroxyl value of 12 mg KOH / g to 42 mg KOH / g (meth) Acrylic resin b. (Meth) acrylic-modified chlorinated polyolefin resin c. A polyisocyanate compound and the above b. The content of the (meth) acrylic-modified chlorinated polyolefin resin is the same as in the above a. The coating composition characterized by being 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic resin.
The polyolefin resin molded object which apply | coated the coating composition as described in 2.1 to the surface.

According to the present invention, a coating film having high gloss can be obtained directly, without the need to intervene an undercoat layer such as a primer, particularly on a polyolefin resin molded article. In addition, it can form a coating film excellent in hot water resistance, volatile oil resistance, acid resistance, alkali resistance, and gasoline resistance, and also has excellent storage stability at extremely low temperatures under human living environment.
Therefore, the coating composition of the present invention exerts an effect that it can be applied particularly to a polyolefin resin molded body to be used in a wider range of environment and / or to be a coating layer of the uppermost layer. It is a thing.

  The coating composition of the present invention can be used for all molded articles made of known polyolefin resins. Because of the good gloss of the coating surface, it can also be the coating layer that is the top layer. It can also be a two-component paint, or a one-component paint.

<A. (Meth) acrylic resin>
As the (meth) acrylic resin used in the present invention, a resin conventionally known as a (meth) acrylic resin can be adopted.
Specifically, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylic acid amide, one or more kinds of nitrogen-containing (meth) acrylic acid esters, and, if necessary, other vinyl monomers, It is a resin obtained by polymerizing by radical polymerization, anionic polymerization or cationic polymerization.

The (meth) acrylic acid ester is, for example, a (meth) acrylic acid ester having an alkyl group, a hydroxyl group-containing alkyl group, an aryl group or an arylalkyl group.
Examples of (meth) acrylic acid ester monomers having an alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) Acrylate, dodecyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate and the like.
Among them, containing an (meth) acrylic acid monomer having a long-chain alkyl group having 12 or more carbon atoms as an alkyl group as a copolymerization component is to improve the adhesion of the coating film to the polyolefin resin molded article. Preferably, when it is contained, the mass fraction of the (meth) acrylic acid monomer component having the long chain alkyl group is 5 parts by mass or more with respect to 100 mass% of the monomer component before the (meth) acrylic resin is polymerized. The amount is preferably 60 parts by mass or less, more preferably 8 parts by mass or more and 40 parts by mass or less, and still more preferably 8 parts by mass or more and 30 parts by mass or less. In particular, lauryl (meth) acrylate is preferably employed.

  Examples of (meth) acrylic acid ester monomers having an aryl group or an arylalkyl group include phenyl (meth) acrylate, toluyl (meth) acrylate, benzyl (meth) acrylate and the like.

  As a (meth) acrylic acid ester having a hydroxyl group-containing alkyl group, a hydroxyl group-containing aryl group or a hydroxyl group-containing arylalkyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl Alkyl groups and aromatic rings of the above acrylic acid esters such as (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyphenyl (meth) acrylate and hydroxybenzyl (meth) acrylate And those having a hydroxyl group bonded thereto are mentioned.

  As (meth) acrylic acid amide, for example, (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-methylethyl (meth) acrylamide, N, N- Monomers having an amide group such as diethylaminopropyl (meth) acrylamide and the like can be mentioned.

  Furthermore, as other nitrogen-containing (meth) acrylic acid esters, various dialkylaminoalkyls such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate and the like Examples include (meth) acrylates and the like.

  As vinyl-based monomers, various styrene-based aromatic monomers (aromatic vinyl-based monomers) such as vinyl acetate, styrene, α-methylstyrene, vinyl toluene or divinylbenzene, dimethyl maleate, diethyl maleate, diethyl fumarate, Diesters of various dicarboxylic acids and monohydric alcohols represented by maleic acid such as dibutyl fumarate and dibutyl itaconate, fumaric acid, itaconic acid and the like can be mentioned.

A. The nature of the (meth) acrylic resin will be described. The hydroxyl value is preferably 12 mg KOH / g to 42 mg KOH / g, and more preferably 20 mg KOH / g to 35 mg KOH / g. If the hydroxyl value is less than 12 mg KOH / g, the resistance to volatile oil and gasoline will be poor, and if it exceeds 42 mg KOH / g, the adhesion of the coating to the polyolefin resin molded article will deteriorate in particular.
Preferably, the glass transition temperature (Tg) is 35 ° C. or more and 70 ° C. or less, and more preferably 40 ° C. or more and 60 ° C. or less. If the glass transition temperature is less than 35 ° C., the resistance to volatile oil and gasoline will be poor, and if it exceeds 70 ° C., the adhesion of the coating to the polyolefin resin molded article will deteriorate in particular.
Preferably, the number average molecular weight (Mn) is 3,000 or more and 10,000 or less, and more preferably 4,000 or more and 8,000 or less. Also, the weight average molecular weight (Mw) is 10,000 or more and 18,000 or less, and more preferably 13,000 or more and 16,000 or less. Furthermore, polydispersity (Mw / Mn) is preferably 1.8 or more and 3.0 or less, and more preferably 2.0 or more and 2.5 or less.
If the number average molecular weight is less than 3,000 or the weight average molecular weight is less than 10,000, volatile oil resistance and gasoline resistance may be poor, the number average molecular weight may exceed 10,000, or the weight average molecular weight may If it exceeds 18,000, adhesion and storage stability may be poor.

<B. (Meth) Acrylic-Modified Chlorinated Polyolefin Resin>
b. As the (meth) acrylic-modified chlorinated polyolefin resin, for example, (meth) acrylic monomers, in the presence of peroxide, d. Method to polymerize the thing obtained by making it graft polymerize to chlorinated polyolefin obtained by the method etc. which are explained by chlorinated polyolefin resin etc., the raw material monomer of chlorinated polyolefin in a solvent, etc. with the above-mentioned acrylic type monomer and other monomers It can be obtained by
As the (meth) acrylic monomer, the monomers listed in the above item <a. (Meth) acrylic resin> can be used.

  b. The polyolefin used for the (meth) acrylic-modified chlorinated polyolefin resin is not particularly limited, and as the polyolefin, for example, an α-olefin-based unsaturated carbonized carbon such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, etc. It is a resin, a rubber-like product, etc. consisting of a copolymer or homopolymer of hydrogen. Specifically, propylene-α-butene copolymer, ethylene-propylene-diene copolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, polyethylene, poly -4- methyl- 1-pentene etc. are mentioned. Furthermore, copolymers of two or more of the above α-olefins with conjugated or nonconjugated dienes, such as ethylene-propylene-butadiene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene-propylene- Ethylidene norbornene copolymer, ethylene-propylene-1,5-hexadiene copolymer, etc., copolymer of α-olefin and conjugated or non-conjugated diene, eg, propylene-butadiene copolymer, propylene-ethylidene norbornene copolymer Copolymers of monomers such as building monomers and α-olefins and partial saponified products thereof are also mentioned as an example.

And b. The (meth) acrylic-modified chlorinated polyolefin resin is a hydroxyl-containing (meth) acrylic-modified chlorinated polyolefin obtained by graft polymerizing a hydroxyl-containing (meth) acrylate to the chlorinated polyolefin in the presence of a peroxide, It is also good.
As a hydroxyl-containing (meth) acrylate used here, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate etc. are mentioned, for example.
b. As the (meth) acrylic-modified chlorinated polyolefin resin, Superclone 223M (manufactured by Nippon Paper Industries Co., Ltd.), 224H, 260F, Acrydic CL-408 (manufactured by DIC Corporation) or the like can be used.
B. In the paint composition of the present invention As content of (meth) acryl modified chlorinated polyolefin resin, said a. Per 100 parts by mass of (meth) acrylic resin, b. The (meth) acrylic-modified chlorinated polyolefin resin is preferably in the range of 10 parts by mass to 30 parts by mass, and more preferably 12 parts by mass to 25 parts by mass. If the content is less than 10 parts by mass, hot water resistance, weather resistance, and adhesion may be poor, and if it exceeds 30 parts by mass, the gloss of the coating film is reduced, volatile oil resistance, acid resistance, alkali resistance , Gasoline resistance, storage stability may be poor.

C. Polyisocyanate compound>
c. It does not specifically limit as a polyisocyanate compound, For example, the compound which has 2 or more of isocyanate groups can be used, for example, tolylene diisocyanate, 4,4'- diphenylmethane diisocyanate, xylylene diisocyanate, metaxylylene diisocyanate And aromatic isocyanates such as hexamethylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; monomers thereof and multimers thereof such as burette type, nurate type and adduct type. It is preferable that the above-mentioned polyisocyanate compound is a multimer because the curability is good. Among them, those having three or more isocyanate groups are preferable.

The polyisocyanate compound may be suitably used either blocked or unblocked.
When a blocked isocyanate is used as the polyisocyanate compound, the blocking agent used is not particularly limited. For example, phenols such as phenol, cresol, xylenol, chlorophenol and ethylphenol; ε-caprolactam, lactams such as δ-valerolactam, γ-butyrolactam and β-propiolactam; active methylenes such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, t-butanol, amyl Alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono 2-ethylhexyl ether, propylene glycol monomethyl ether, Alcohols such as methyl lactate, butyl glycolate, diacetone alcohol, methyl lactate and ethyl lactate, furfuryl alcohol; oximes such as formaldoxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime Mercaptan such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethylthiophenol etc; acid amide type such as acetic acid amide and benzamide; imido type such as succinic acid imide and maleic acid imide; Examples include imidazoles such as 2-ethylimidazole; secondary amines such as dimethylamine, diethylamine and dibutylamine.

  c. Commercially available products can be used as the polyisocyanate compound, and "Colonet HX" (manufactured by Tosoh Corp.), "Duranate TPA-100" (manufactured by Asahi Kasei Corp.), as a commercial product modified with isocyanurate, "Takenate D-170N" (manufactured by Mitsui Chemicals, Inc.) and the like. "Bunate T-165NN" (Mitsui Chemical Co., Ltd. product) etc. are mentioned as a burette-modified commercial item. In addition, commercially available trimethylolpropane adduct-modified "Coronato L" (Tosoh Co., Ltd.), "Takenate D-102" (Mitsui Chemical Co., Ltd.), "Takenate D-140N" And the like. Furthermore, as a commercial product of block type isocyanate stabilized by masking an isocyanate with a blocking agent, "Coronato 2507" (made by Tosoh Corp.), "Coronato 2513" (made by Tosoh Corp.), etc. may be mentioned.

  In the paint composition of the present invention, c. The polyisocyanate compound is a. It can be blended so as to be preferably in the range of 5 parts by mass to 20 parts by mass, more preferably 5 parts by mass to 15 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin. Or c. Isocyanate groups (NCO groups) in the polyisocyanate compound and a. The equivalent ratio (NCO / OH) to the hydroxyl group (OH group) in the (meth) acrylic resin is preferably 0.5 / 1 or more and 3.0 or more from the viewpoint of the balance between the adhesion and the curability of the obtained coating film. / 1 or less, more preferably 0.8 / 1 or more and 2.5 / 1 or less. Here, when the equivalent ratio (NCO / OH) is 0.5 / 1 or less, the chemical resistance may be poor, and when the equivalent ratio (NCO / OH) is 3.0 / 1 or more, the usable life becomes short. there is a possibility.

<D. Chlorinated polyolefin resin>
The coating composition of the present invention comprises d. You may contain chlorinated polyolefin resin. A chlorinated polyolefin resin is a resin obtained by introducing chlorine into a polyolefin resin. As polyolefin which is a raw material of chlorinated polyolefin resin, said b. The polyolefin used by (meth) acryl modified | denatured chlorinated polyolefin resin is employable. d. As chlorinated polyolefins, Super Clon 822, 3221 S, 3228 S (manufactured by Nippon Paper Industries Co., Ltd.) and the like can be used.
The coating composition of the present invention d. When blending chlorinated polyolefin resin, a. It may be blended so as to be preferably up to 10 parts by mass, more preferably up to 8 parts by mass, with respect to 100 parts by mass of the (meth) acrylic resin. When it is compounded in more than 10 parts by mass, the glossiness, volatile oil resistance, gasoline resistance and storage stability may be inferior.
d. The production method of the chlorinated polyolefin resin is not particularly limited, but it is a solution chlorination method in which the polyolefin is dissolved in an organic solvent such as carbon tetrachloride to be chlorinated, a method of chlorinating the polyolefin in a bulk state, an aqueous suspension of the polyolefin Methods for chlorination are known.

For example, in the solution chlorination method, introduction of chlorine can be carried out by blowing chlorine gas into the reaction system. The blowing of chlorine gas may be performed under irradiation of ultraviolet light, or may be performed in the presence or absence of a radical reaction initiator. The pressure at which the chlorine gas is blown is not limited, and may be normal pressure or may be under pressure. The temperature at which the chlorine gas is blown is not particularly limited, but is usually 50 to 140 ° C.
Thus, chlorine can be introduced into the polyolefin to obtain a chlorinated polyolefin. Thereafter, the chlorinated solvent in the system is usually distilled off under reduced pressure or the like, or replaced with an organic solvent.

  Organic peroxide compounds or azonitriles may be used as the radical reaction initiator. Examples of organic peroxide compounds include di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, benzoyl peroxide, dilauryl peroxide, 2,5-dimethyl-2,5- Di (tert-butylperoxy) hexane, cumene hydroperoxide, tert-butyl hydroperoxide, 1,1-bis (tert-butylperoxy) -3,5,5-trimethylcyclohexane, 1,1-bis (tert) -Butylperoxy) -cyclohexane, cyclohexanone peroxide, tert-butylperoxybenzoate, tert-butylperoxyisobutyrate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxy 2-ethyl hexanoate, tert- butylperoxy isopropyl carbonate, and the like cumylperoxy octoate. As azonitriles, for example, 2,2-azobis (2-methylbutyronitrile), 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethyl valeronitrile), 2,2 Azobis (4-methoxy-2,4-dimethylvaleronitrile) and the like.

  The coating composition according to the present invention may contain, if necessary, a pigment, an organic solvent, a curing catalyst, a surface conditioner, an antisettling agent, an antifoaming agent, a viscosity regulator, a glitter orientation agent, an ultraviolet absorber (UVA), light You may contain components, such as a stabilizer (HALS). As a pigment which can be used for the coating composition of this invention, a metallic pigment, a pearl pigment, a color pigment, and an extender pigment can be mentioned. Examples of the metallic pigment include aluminum flakes, copper bronze flakes, mica-like iron oxide, mica flakes, mica-like iron oxide coated with metal oxide, mica flakes coated with metal oxide, and the like. Examples of the pearl pigment include titanium oxide coated mica, titanium oxide coated mica, bismuth oxychloride, titanium oxide coated bismuth oxychloride, titanium oxide coated talc, fish scale foil, titanium oxide coated colored mica and the like. Examples of color pigments include inorganic pigments such as titanium dioxide, iron oxide, chromium oxide, lead chromate and carbon black; azo lake pigments, insoluble azo pigments, condensation azo pigments, phthalocyanine pigments, indigo pigments, perinone And organic pigments such as based pigments, perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, benzimidazolone pigments, diketopyrrolopyrrole pigments, metal complex pigments and the like. Examples of the extender pigment include talc, calcium carbonate, precipitated barium sulfate, silica and the like. These may be used alone or in combination of two or more.

The coating composition of the present invention can be used as a coating for coating the surface of a polyolefin resin molded article. The polyolefin-based resin molded product may be a known polyolefin-based resin molded product such as polypropylene, polyethylene, ethylene propylene copolymer, etc., and may be crosslinked, uncrosslinked, or an elastomer.
The coating composition of the present invention may be a colored or colorless clear coating, or may be a colored coating. If necessary, an undercoat layer may be formed in advance on the surface of the polyolefin resin molded article, or the undercoat layer may not be formed. Moreover, although a top coat layer and a printing layer can be further formed on the coating film which consists of a coating composition of this invention, it is not necessary to form.
Moreover, the coating composition of the present invention comprises a. A component containing a (meth) acrylic resin and c. It can be set as a two-component type paint composition which consists of two components with the component containing a polyisocyanate compound, and it can also be set as one-component type, adopting block polyisocyanate etc. as a polyisocyanate compound. At this time, b. The (meth) acrylic-modified chlorinated polyolefin resin comprises the above-mentioned a. A component and / or c. It can be blended with the ingredients.

<A. Synthesis of (meth) acrylic resin (A-1 to A-19)>
Synthesis Example 1
In a four-necked flask equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, and a dropping device, 150 parts by mass of isobutyl acetate was charged, and the temperature was raised to 90 ° C. while stirring in a nitrogen stream.
47 parts by mass of methyl methacrylate (MMA), 35 parts by mass of n-butyl methacrylate (BMA), 10 parts by mass of lauryl methacrylate (LMA), 7 parts by mass of hydroxyethyl methacrylate (HEMA), 1 part by mass of methacrylic acid (MAA), A mixed solution consisting of 3 parts by mass of 2,2′-azobis (2-methylbutyronitrile) (ABN-E, manufactured by Nippon Finechem Co., Ltd.) was dropped into the flask over 2 hours using a dropping device. The polymerization reaction was carried out.
After all the mixture was dropped, the polymerization reaction was carried out by continuing the stirring for 3 hours at 90 ° C. to synthesize a (meth) acrylic resin (A-1). The heating was stopped and cooled to room temperature to obtain a resin composition (solid content ratio 40 mass%) containing (A-1) resin.
The hydroxyl value of the obtained (meth) acrylic resin (A-1) was 30 mg KOH / g, and the weight average molecular weight was 15,000. In addition, the glass transition temperature (Tg) of (meth) acrylic resin (A-1) calculated theoretically from the compounding ratio of the used monomer was 44 degreeC.

(Composition examples 2 to 19)
(Meth) acrylic resins (A-2) to (A-19) are synthesized by the same method as in Synthesis Example 1 according to the compounding ratio described in Tables 1 and 2 below, and a resin composition containing each (meth) acrylic resin I got
In addition, how to obtain the hydroxyl value, weight average molecular weight and glass transition temperature of each of the obtained resins is as follows.

In the synthesis of the (meth) acrylic resin (A-1 to A-19), those shown below were used except those described in the above-mentioned Synthesis Example 1.
tBMA ··· t-Butyl methacrylate Light ester L-7 · · · Mixture of (meth) acrylates with long-chain alkyl having 12 to 13 carbons (Keieisha Chemical Co., Ltd. product)
SA: Stearyl acrylate HEA: hydroxyethyl acrylate

The calculation method of "glass transition temperature" described in Tables 1 and 2 will be described.
<Calculation of glass transition temperature>
The glass transition temperature of the (meth) acrylic resin is the glass transition temperature (Tg) (absolute temperature: K) of the homopolymer composed of the monomer contained in the monomer component used as the raw material of the resin, and the mass fraction of the monomer From the formula (I):
1 / Tg = W1 / Tg1 + W2 / Tg2 + W3 / Tg3 +... + Wn / Tgn (I)
[Wherein, Tg is the glass transition temperature (K) of the (meth) acrylic resin to be determined, W1, W2, W3... Wn is the mass fraction of each monomer, Tg1, Tg2, Tg3. Tgn can be determined based on the equation of Fox, which represents the glass transition temperature (K) of a homopolymer comprising a monomer corresponding to the mass fraction of each monomer.
In the present invention, the glass transition temperature of the (meth) acrylic resin means the glass transition temperature determined based on the formula (I). In addition, about the monomer whose glass transition temperature is unknown, such as a special monomer and a polyfunctional monomer, the glass transition temperature was calculated | required using only the monomer in which the glass transition temperature is known.

The measuring method of "hydroxy value" described in Tables 1 and 2 and the measuring equipment and measuring conditions of "number average molecular weight" and "weight average molecular weight" will be described.
(Measurement of hydroxyl value)
Approximately 1 g of a sample (resin solution: about 50%) is precisely weighed in a stoppered conical flask, and 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. Furthermore, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this was added phenolphthalein test solution as an indicator and sustained for 30 seconds. The solution was then titrated with 0.1 N alcoholic potassium hydroxide solution until the solution turned pink.
The hydroxyl value was determined by the following formula. The hydroxyl value is a numerical value of the dry state of the resin (unit: mg KOH / g).
Hydroxyl value (mg KOH / g) = [{(b-a) × F × 28.25} / S] / (nonvolatile content concentration / 100) + D
However,
S: Amount of sample collected (g)
a: Consumption of 0.1 N alcoholic potassium hydroxide solution (ml)
b: Consumption of empty 0.1 N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1 N alcoholic potassium hydroxide solution D: Acid value (mg KOH / g)

(Measurement of number average molecular weight, weight average molecular weight)
The following gel permeation chromatography (GPC) system measurement conditions were used.
Equipment used: HLC8220GPC (made by Tosoh Corporation)
Column used: TSKgel Super HZM-M, TSKgel GMHXL-H, TSKgel G2500HXL, TSKgel G5000HXL (manufactured by Tosoh Corp.)
Column temperature: 40 ° C
Standard substance: TSKgel Standard polystyrene A1000, A2500, A5000, F1, F2, F4, F10 (manufactured by Tosoh Corp.)
Detector: RI
Eluent: tetrahydrofuran Flow rate: 1 ml / min

Preparation of Coating Composition <Example 1>
250 parts by mass (100 parts by mass as solid content) of a resin composition containing a (meth) acrylic resin (A-1), an acrylic modified chlorinated polyolefin (Nippon Paper Industries Co., Ltd. Super Clon 223 M, solid content 35% by mass) 40 parts by mass (as solid content: 14 parts by mass), isocyanate compound (Asahi Kasei Co., Ltd. TPA-100: a nurate type of hexamethylene diisocyanate, isocyanate group content 23 mass%, solid content 100 mass%) 10 mass Parts were mixed and further diluted with isobutyl acetate to prepare a coating composition (solid content ratio 20% by mass).

Examples 2 to 21 and Comparative Examples 1 to 21
Each coating composition of Examples 2-21 and Comparative Examples 1-21 was obtained like Example 1 according to the compounding ratio of Tables 3-6.
The following were used in preparation of each paint composition of an Example and a comparative example.
Super Clon 223 M: acrylic modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., solid content 35% by mass
Super Clon 224H: Acrylic modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., solid content 40% by mass
Super Klon 260F: Acrylic modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., solid content 35% by mass
Acrylic CL-408: Acrylic modified chlorinated polyolefin manufactured by DIC Corporation, solid content 60% by mass
TPA-100: Nurate type of hexamethylene diisocyanate manufactured by Asahi Kasei Co., Ltd., isocyanate content 23% by mass, solid content 100% by mass
Supercron 822: Acid-modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., chlorine content 24.5%, solid content 20% by mass
Superkuron 3221S: Acid-modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., chlorine content 21.0%, solid content 100% by mass
Superclone 3228S: Acid-modified chlorinated polyolefin manufactured by Nippon Paper Industries Co., Ltd., chlorine content 28.0%, solid content 100% by mass
In addition, the compounding quantity of Tables 3-6 is shown by solid content.

<Creating test plate>
Each paint composition is applied by spray onto a polypropylene substrate (size 150 mm × 100 mm × 1.5 mm) degreased with isopropanol, allowed to stand at room temperature for 10 minutes, and then heat cured at 80 ° C. for 40 minutes, Each test board which has a 20-micrometer-thick coating film was produced.
In addition, about evaluation of the glossiness mentioned later, the coating material composition for gloss evaluation (The solid content of 100 mass parts of a coating composition is 7 mass parts (solids (solid content separately) from the coating composition used above) The composition was prepared by adding a fraction ratio), was similarly spray coated on a polypropylene substrate using the same, and was cured by heating to prepare a test plate for gloss evaluation.
The aluminum paste used was Al Paste 1109M (aluminum pigment, solid content 65% by mass) manufactured by Toyo Aluminum Co., Ltd.

<Evaluation>
"Adhesiveness""luster""warm water resistance""volatilization oil resistance""acidresistance""alkaliresistance""gasolineresistance""storagestability" of Examples 1 to 21 and Comparative Examples 1 to 21 The evaluation method and evaluation criteria of the "quality" evaluation are described below, and the evaluation results are shown in Tables 3 to 6.
(Adhesiveness)
The adhesion test was conducted by the cross cut method based on JIS K 5600-5-6 "Mechanical Properties of Coating-Adhesion", and the adhesion of the coating to a polypropylene substrate was evaluated based on the following evaluation criteria.
In the evaluation, 5 is good and shows a bad result as the score is lowered.
Those with this evaluation of 4 or more were judged to be paint compositions excellent in adhesion.
5: The edges of the cut are completely smooth and there is no peeling off in any grid 4. 4: There is a small peeling of the coating at the intersection of the cut, the area of the peeling portion is less than 5% 3: The area of the peeling portion Is 5% or more and less than 15% 2: area of the peeled portion is 15% or more and less than 35% 1: area of the peeled portion is 35% or more

(Glossy)
Using a test plate for gloss evaluation, the 60 ° gloss value was measured using a gloss meter (manufactured by BYK-Gardner GmbH). The higher the gloss value, the better the coating appearance.
Those having a gloss value of 90 or more were judged to be paint compositions excellent in gloss.

(Hot water resistance)
The test plate was immersed in warm water at 40 ° C. for 10 days by a method in accordance with JIS K 5600-6-2 “Chemical Properties of Coating Film—Liquid Resistance (Water Immersion Method)”. After 10 days, the test plate was taken out of the hot water and dried at room temperature for 24 hours, and then the appearance of the coating was visually observed. Evaluation was performed on the basis of the following. Moreover, about the test board after warm water immersion, the above-mentioned adhesiveness test was done and adhesion evaluation was also performed.
○: No appearance abnormality such as blister, whitening, swelling, cracking, peeling, etc. ×: Appearance abnormality such as blistering, whitening, swelling, cracking, peeling

(Volatile oil resistance, acid resistance, alkali resistance)
By observing the state of the coating film after immersing the test plate in each solvent according to the method according to JIS K 5600-6-1 “Chemical Properties of Coating Film-Liquid Resistance (General Method)” Each evaluation of volatile resistance, acid resistance, and alkali resistance was performed. The test conditions for each evaluation were as follows.
Volatile oil resistance: Heptane was used as a solvent for immersing the test plate. The immersion temperature was 25 ° C., and the immersion time was 3 hours.

The volatile oil resistance was visually evaluated on the basis of the following criteria of the state (swelling) of the coating film of the test plate.
The higher the value, the better the result.
Those having a rating of 4 or more were judged to be paint compositions excellent in volatile oil resistance.
5: There is no coating blistering at all.
4: The area of the portion of the coating film blister relative to the test coating film is judged to be less than 1%.
3: The area of the portion of the coating film blister relative to the test coating film is judged to be 1% or more and less than 3%.
2: The area of the portion of the coating film blister relative to the test coating film is determined to be 3% or more and less than 7%.
1: The area of the portion of the coating film blister relative to the test coating film is determined to be 7% or more.

Acid resistance: The solvent for immersing the test plate used 0.1 N hydrochloric acid. The immersion temperature was 25 ° C., and the immersion time was 24 hours.
Alkali resistance ··· A solvent for immersing the test plate used a 0.1 N aqueous solution of sodium hydroxide. The immersion temperature was 55 ° C., and the immersion time was 4 hours.

Acid resistance and alkali resistance measured the rate of change in chromaticity before and after the test. The reflectance and chromaticity (L value, a value, b value) of wavelength 460nm were measured using the spectroscopy color difference meter (CM-3700A, Konica Minolta Co., Ltd. product made).
Furthermore, the rate of change in chromaticity (ΔE * ab) before and after the test was determined using Formula 1 from the measurement results of the obtained chromaticity.
ΔE * ab = ((ΔL *) 2+ (Δa *) 2+ (Δb *) 2) 1/2 (Equation 1)
The obtained ΔE * ab was evaluated based on the following criteria.
The higher the value, the better the result.
Those with four or more evaluations were judged to be coating compositions having excellent acid resistance or alkali resistance.
5: ΔE is less than 1.
4: ΔE is 1 or more and less than 2.
3: ΔE is 2 or more and less than 3.
2: ΔE is 3 or more and less than 5.
1: ΔE is 5 or more.

(Gasoline resistance)
The absorbent cotton fully impregnated with gasoline was placed on the coating film of each test plate, and the state of the coating film was subjected to visual observation after rubbing for 20 reciprocations under a load of 500 g.
The evaluation of the peeling of the coating was evaluated based on the following criteria.
The higher the value, the better the result.
Those with this evaluation of 4 or more were judged to be paint compositions excellent in gasoline resistance.
5: Not visible even when the size of peeling is enlarged by 10 times 4: The size of peeling is less than 1 mm 3: the size of peeling is 1 mm or more but less than 3 mm 2: the size of peeling is 3 mm or more but less than 10 mm 1: peeling 10mm or more

(Storage stability (-20 ° C))
According to the method described in "4. Low temperature stability" of JIS K 5600-2-7, c. Each paint composition before adding a polyisocyanate compound, ie, a. A component and b. Ingredient and optionally d. The composition in which the components were mixed was stored at -20 ° C for 7 days, and after 7 days, the condition was observed and evaluated based on the following criteria.
○: Good fluidity ×: Crystal formation, thickening observed

According to Examples 1 to 21 which are specific examples according to the present invention, adhesion, hot water resistance, volatile oil resistance, acid resistance, alkali resistance, gasoline resistance, storage stability are excellent, and gloss is high. It played an effect.
On the other hand, b. Comparative Example 1 in which the content of the (meth) acrylic-modified chlorinated polyolefin is small, b. According to Comparative Example 11 in which the (meth) acrylic modified chlorinated polyolefin is not contained, the adhesion is poor, and according to Comparative Examples 2 and 3 in which the content of the acrylic modified chlorinated polyolefin is large, the gloss is low and resistance The results were poor in volatile oil, gasoline resistance and storage stability.
According to Comparative Example 4 in which the (meth) acrylic resin does not contain a long chain alkyl group, the adhesion was inferior. Furthermore, according to Comparative Examples 5 to 7 and 15 to 17 in which the hydroxyl value of the (meth) acrylic resin is low, at least the volatile oil resistance and gasoline resistance are poor, and in some cases, the hot water resistance, acid resistance and alkali resistance are also poor It became. Conversely, according to Comparative Examples 8 to 10 and 12 to 14 in which the hydroxyl value of the (meth) acrylic resin is too high, at least the adhesion as the hot water resistance was inferior. Similarly, according to Comparative Examples 20 and 21 in which the hydroxyl value of the (meth) acrylic resin is high, the volatile oil resistance, the gasoline resistance and the storage stability are poor.
Further, according to Comparative Example 18 in which the glass transition temperature of the (meth) acrylic resin is low, the result was inferior in volatile oil resistance and gasoline resistance. According to Comparative Example 19 in which the glass transition temperature of the (meth) acrylic resin is too high, the adhesion was poor.
c. According to the comparative example 5 which does not use a polyisocyanate compound, the result was inferior to volatile oil resistance, acid resistance, alkali resistance, and gasoline resistance.

Claims (2)

The following a. ~ C. Contains the ingredients of
a. Containing a monomer component having a long chain alkyl group as a constituting monomer unit, having a glass transition temperature (Tg) of 35 ° C. to 70 ° C., and a hydroxyl value of 12 mg KOH / g to 42 mg KOH / g (meth) Acrylic resin b. (Meth) acrylic-modified chlorinated polyolefin resin c. A polyisocyanate compound and the above b. The content of the (meth) acrylic-modified chlorinated polyolefin resin is the same as in the above a. The coating composition characterized by being 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic resin. The polyolefin resin molded object which apply | coated the coating composition of Claim 1 to the surface.