JP2016023304A - Coating composition for inner package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition having reduced content of carbon black.SOLUTION: There is provided a coating composition for inner package containing an aqueous urethane resin (A), an aqueous chlorinated polyolefin modified acryl resin (B), an aqueous polyolefin resin (C), a resin particle (D) and a coloring pigment (E), carbon black of 1 mass% or less and the coloring pigment other than carbon black of 5 mass% or more and less than 30 mass% based on dry coating mass and having brightness Lof a coating film formed from the coating composition of 20 to 30 and hiding power by a white and black hiding test sheet of 10 μm to 20 μm.SELECTED DRAWING: None

Description

  The present invention relates to an interior coating composition.

  Automotive interior parts such as instrument panels, center consoles, door trims, etc. are usually coated with a one-component paint containing polyolefin resin and color pigment from the viewpoint of adhesion, etc. In general, carbon black is used as a black pigment.

  As a black paint composition containing carbon black as a color pigment, for example, Patent Document 1 discloses that an amine compound is added to carbon black whose total oxygen calculated from an oxygen compound in a volatile composition at 950 ° C. is 10 mg / g or more. A black coating composition characterized by using an improved modified carbon black is described.

Patent Document 2 discloses a black metallic color molding resin composition having a lightness (L ^* ) value of less than 60 by adding carbon black and an organic black colorant together to an amorphous resin containing a glittering material. Things are listed.

  However, the oil absorption of dibutyl phthalate (DBP) in carbon black is as high as 50 to 150 ml / 100 g, and the lipophilicity is high. Therefore, if the carbon black content in the paint is high, the oil resistance of the coating film decreases.

  Moreover, since carbon black has few surface functional groups, it has low surface energy and is difficult to disperse. Therefore, with a paint containing carbon black, it is difficult to increase the pigment concentration (PWC) in the coating film, and the PWC of carbon black is usually about 3 to 5%, and the ratio of the resin component in the coating film Is big. A black paint having a low PWC increases the internal distortion of the coating film, and thus the adhesion of the coating film to an object is reduced. In addition, when a large amount of a pigment dispersant is used to disperse carbon black, physical properties such as moisture resistance of the coating film deteriorate.

  Furthermore, since carbon black has a large ability to absorb infrared rays from sunlight, in paints containing carbon black, the absorbed infrared rays are converted into vibrational heat, which increases the temperature of the coating film and the object to be coated. Oxidation deterioration and hydrolysis resistance deterioration of the coating film are promoted.

JP-A-3-244672 JP 2012-162695 A

  As described above, there are various disadvantages in coating compositions containing carbon black. Therefore, an object of the present invention is to provide a coating composition having a reduced carbon black content.

  As a result of various studies on means for solving the above problems, the present inventors have identified the content of the color pigment contained in the coating composition, and the type and content of the resin material in the coating composition. The present inventors have found that the carbon black content can be reduced.

That is, the gist of the present invention is as follows.
(1) An interior coating composition comprising an aqueous urethane resin (A), an aqueous chlorinated polyolefin-modified acrylic resin (B), an aqueous polyolefin resin (C), resin particles (D), and a color pigment (E). The amount of the resin (C) with respect to the total mass of the resins (A), (B) and (C) is 15% by mass to 50% by mass, and the solid content mass ratio of the resins (A) and (B) [(A ) / (B)] is 90 / 10-50 / 50, the elongation at 20 ° C. of the resin (A) is 100% or more, and the chlorinated polyolefin modification amount of the resin (B) is 5% by mass to 40%. It is an aqueous polypropylene-based resin in which the resin (C) is not chlorinated, the crystallinity is 35% to 50%, the mass average molecular weight is 50,000 to 200,000, and the coloring pigment (E ) Carbon black content is dry paint film The content of the color pigment other than carbon black is 5% by mass or more and less than 30% by mass with respect to the dry coating mass, and the brightness of the coating film formed from the coating composition L ^* is 20-30, and the coating power for interiors characterized by the hiding power in a black-and-white hiding test paper being 10 micrometers-20 micrometers.

  According to the present invention, it is possible to provide a coating composition having a reduced carbon black content.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The interior coating composition of the present invention includes an aqueous urethane resin (A), an aqueous chlorinated polyolefin-modified acrylic resin (B), an aqueous polyolefin resin (C), resin particles (D), and a color pigment (E).

  The aqueous urethane resin (A) used in the interior coating composition of the present invention is a component that forms a matrix of a coating film, and can be melted by heat. The compounding amount of the aqueous urethane resin (A) is preferably 25% by mass to 75% by mass when the total mass of the resins (A), (B) and (C) is 100% by mass. When the blending amount of the aqueous urethane resin (A) is within this range, sufficient adhesion between the obtained coating film and the substrate can be ensured.

  The aqueous urethane resin (A) has an elongation at 100C of 100% or more. When the elongation percentage is within the above range, the resulting coating film has a sufficient soft feeling. The elongation percentage is more preferably 200% or more, and the upper limit is preferably 1000% or less.

  Examples of the aqueous urethane resin (A) include a polyfunctional isocyanate compound, a polyol having two or more hydroxyl groups in one molecule, and a hydrophilizing agent having both a hydroxyl group and a carboxylic acid group such as dimethylolpropanoic acid or dimethylolbutanoic acid. To the urethane prepolymer obtained by reacting in the presence of a catalyst such as dibutyltin dilaurate in an excess of isocyanate group, with a carboxylic acid by an organic base such as amines or an inorganic base such as potassium hydroxide or sodium hydroxide. Neutralized, added with ion-exchanged water to make it aqueous, and then urethane dispersion with higher molecular weight by chain extender; synthesized urethane prepolymer not containing carboxylic acid, carboxylic acid, sulfonic acid, ethylene glycol, etc. After the chain extension using a diol or diamine having a hydrophilic group of And urethane dispersions emulsifier obtained in combination if necessary; and neutralized with quality and water-further urethane dispersion was high molecular weight using a chain extender as needed.

  Examples of the polyfunctional isocyanate compound include 1,6-hexane diisocyanate, lysine diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate. Examples thereof include polyfunctional isocyanate compounds such as compounds and adducts, burettes, and isocyanurates.

  Examples of the polyol include polyester polyol, polyether polyol, and polycarbonate polyol.

  Examples of the chain extender include low molecular weight diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, furan methanol, diethylene glycol, triethylene glycol and tetraethylene glycol, and ethylene oxide and propylene oxide. A polyether diol compound obtained by addition polymerization of tetrahydrofuran, etc .; having a hydroxyl group at the terminal obtained from the above low molecular weight diol compound and dicarboxylic acids such as (anhydrous) succinic acid, adipic acid, (anhydrous) phthalic acid, and the like. Polyester diols; polyhydric alcohols such as trimethylolethane and trimethylolpropane; aminoalcohols such as monoethanolamine, diethanolamine and triethanolamine; Min, propylene diamine, butylene diamine, hexamethylene diamine, phenylene diamine, toluene diamine, xylene diamine, diamine compounds such as isophoronediamine; water, ammonia, hydrazine, may be mentioned dibasic acid hydrazide and the like.

  A commercially available urethane dispersion can also be used for the water-based urethane resin (A). The commercially available urethane dispersion is not particularly limited. For example, Adekabon titer HUX561, Adekabon titer HUX210, Adekabon titer HUX980 (manufactured by ADEKA), Bihydrol VP LS2952 (manufactured by Sumika Bayer Urethane), VONDIC 2260, VONDIC 2220, hydran WLS210, hydran WLS213 (manufactured by Dainippon Ink & Chemicals, Inc.), NeoRez R9603 (manufactured by Avicia), and the like.

  The aqueous chlorinated polyolefin-modified acrylic resin (B) used in the interior coating composition of the present invention is a component that forms a matrix of a coating film, and can be melted by heat. By containing the resin (B), the interior coating composition of the present invention can impart excellent scratch resistance and adhesion to a substrate to the formed coating film.

  The blending amount of the resin (B) is preferably 5% by mass to 42% by mass when the total mass of the resins (A), (B) and (C) is 100% by mass. When the blending amount of the resin (B) is within this range, the resulting coating film has sufficient scratch resistance and adhesion to the substrate.

  Examples of the polyolefin used for the production of the aqueous chlorinated polyolefin-modified acrylic resin (B) include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, polybutene, and styrene-butadiene-isoprene. And chlorinated products of the above-mentioned copolymer.

  The acrylic polymer chain portion in the aqueous chlorinated polyolefin-modified acrylic resin (B) is a polymer chain grafted to the polyolefin portion or a block polymer chain attached to the end of the polyolefin. The glass transition temperature (Tg) of the acrylic polymer chain portion is preferably 50 ° C. to 120 ° C. from the viewpoint of scratch resistance, oil resistance, film forming property and water resistance of the resulting coating film, and is 70 ° C. More preferably, it is -100 degreeC.

  The acrylic polymer chain portion includes a structural unit derived from an acrylic monomer as an essential component, but may be a copolymer portion further including a structural unit derived from another monomer as appropriate. Examples of the acrylic monomer include (meth) acrylic acid ester monomers such as acrylic acid, methacrylic acid, and (meth) acrylic monomers. Examples of the other monomers include styrene monomers such as styrene and α-methylstyrene, and hydroxyl group-containing vinyl monomers such as 4-hydroxybutyl vinyl ether.

  As a (meth) acrylic acid ester monomer, a (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms, for example, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) N-propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, (meth) acrylic acid Hexyl, cyclohexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, etc. (Meth) acrylic having an aryl group or arylalkyl group having 6 to 12 carbon atoms Ester monomers -, for example, (meth) acrylate, phenyl (meth) toluyl acrylate include benzyl (meth) acrylate and the like. In the present specification, the expression “(meth) acryl” means “acryl or methacryl”.

  Further, a (meth) acrylic acid ester monomer having a hetero atom-containing alkyl group having 1 to 20 carbon atoms, such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylic 2-aminoethyl acid, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, (meth ) Monomers of (meth) acrylic acid esters having an alkyl group having 1 to 20 carbon atoms containing fluorine atoms, such as adducts of glycidyl acrylate and (meth) acrylic acid ethylene oxide, such as tri (meth) acrylic acid Fluoromethylmethyl, 2-trifluoromethylethyl (meth) acrylate, ( Data) acrylic acid 2 Pas - fluoroethyl ethyl and the like, (meth) acrylamide monomer, e.g., (meth) acrylamide, (meth) acrylic dimethyl amides.

  The method for producing the aqueous chlorinated polyolefin-modified acrylic resin (B) is, for example, by dissolving chlorinated polyolefin in a solvent and in the presence of a peroxide, an acid such as (meth) acrylic acid. A method in which the acrylic monomer is copolymerized with other acrylic monomers and graft-copolymerized to chlorinated polyolefin, neutralized with amine, and then added with ion-exchanged water to make it aqueous, or the chlorinated polyolefin and acrylic monomer Examples thereof include an emulsion polymerization method and a fine suspension polymerization method in which emulsification is performed in advance using an emulsifier and then polymerization is performed using a polymerization initiator.

  The resin (B) has a chlorinated polyolefin modification amount in the resin (B) in the range of 5% by mass to 40% by mass. When the chlorinated polyolefin modification amount in the resin (B) is 5% by mass or more, the compatibility between the urethane resin (A) and the polypropylene resin (C) does not decrease, and the adhesion and scratch resistance decrease. There is no fear of it. When the chlorinated polyolefin modification amount in the resin (B) is 40% by mass or less, sufficient oil and fat resistance is obtained. The modification amount can be calculated from the blending amount.

  In the interior coating composition of the present invention, the solid content mass ratio [(A) / (B)] of the resins (A) and (B) is 90/10 to 50/50, and 80/20 to 60. / 40 is preferable. When the above (A) / (B) is within the above range, adhesion between the obtained coating film and the substrate is sufficient, and the obtained coating film has sufficient oil resistance.

  The water-based polyolefin resin (C) used in the interior coating composition of the present invention is a component that forms a matrix of a coating film, and can be melted by heat. The amount of the resin (C) is 15% by mass to 50% by mass, and 20% by mass to 40% by mass when the total mass of the resins (A), (B) and (C) is 100% by mass. It is preferable that When the amount of the resin (C) is 15% by mass or more, the adhesion between the obtained coating film and the substrate, the moisture resistance, oil resistance and light resistance of the coating film are sufficient, and it is 50% by mass or less. This is because the oil resistance of the coating film is sufficient.

  The resin (C) is an aqueous polypropylene resin that is not chlorinated. By using a non-chlorinated aqueous polypropylene-based resin for the coating composition, it is possible to enhance the adhesion of the obtained coating film and the substrate by low-temperature baking drying. Examples of the non-chlorinated aqueous polyolefin resin include a propylene homopolymer and a copolymer of propylene and a chlorine-free monomer (such as ethylene) copolymerizable with propylene. Homopolymers and copolymers of propylene and ethylene are preferred.

  The resin (C) is preferably a polypropylene resin in which 90% by mass or more of the constituent monomer is propylene from the viewpoint of the oil and fat resistance of the coating film.

  In the polypropylene resin, examples of the constituent monomer other than propylene include mono- or diolefins having 2 or 4 to 20 carbon atoms, such as butene, pentene, hexene, octene, decene, butadiene, hexadiene, octadiene, and cyclobutene. , Cyclopentene, cyclohexene, norbornene, norbornadiene, styrene and derivatives thereof. In this specification, monomer content which comprises resin can be calculated | required by the amount of each monomer used for manufacture of resin.

  The resin (C) is preferably obtained using a metallocene catalyst. This generally indicates that metallocene catalysts can control microtacticity by ligand design, that is, the resulting polypropylene backbone, unlike atactic polypropylene, contains crystallizable chain length isotactic blocks. In other words, the presence of an isotactic block means that a block composed of a sequence having a disordered stereospecificity is also present in the main chain at the same time. That is, in a polypropylene main chain polymerized using a metallocene catalyst, a crystalline block and an amorphous block coexist, and the crystalline block has an isochron having a relatively long average chain length. It is formed from a tactic block and has a unique structure that is rich in isotacticity. Because of these features, paints using polyolefin polymerized using a metallocene catalyst can have a soft feeling due to oil resistance, adhesion, elongation control, etc. of the coating film obtained even at low temperatures. It becomes.

  As the metallocene catalyst, conventionally known ones can be used, and examples include those described in JP-A No. 2004-115712 ([0021] to [0052]).

  The resin (C) is preferably a resin modified with an unsaturated organic acid or an acid anhydride thereof (hereinafter sometimes referred to as a modified polypropylene resin). As what was modified | denatured by the said unsaturated organic acid or its acid anhydride, for example, the main chain of the said polypropylene resin is made to graft-react the unsaturated carboxylic acid of 3-25 carbon atoms or its acid anhydride. Denatured ones can be mentioned. This grafting reaction can be carried out by a conventional method using a radical generator.

  Examples of unsaturated carboxylic acids or acid anhydrides to be grafted include maleic acid, fumaric acid, itaconic acid, tetrahydrophthalic acid, citraconic acid, crotonic acid, allyl succinic acid, mesaconic acid, aconitic acid, and anhydrides thereof. Of these, maleic acid and its anhydride are preferred.

  The addition ratio of unsaturated carboxylic acid or acid anhydride thereof in the modified polypropylene resin that can be used in the present invention (content ratio of unsaturated carboxylic acid or acid anhydride in the modified polypropylene resin) is usually 0.00. It is 01 mass%-20 mass%, Preferably it is 0.1 mass%-5 mass%. When the addition ratio is 0.01% by mass or more, the dispersion stability of the resulting coating composition is good, and when it is 20% by mass or less, the water resistance of the coating film does not deteriorate. This addition rate can be measured by comparing the absorption intensity of the carbonyl group with a calibration curve prepared on the basis of a sample having a known addition rate (content) by infrared spectroscopy.

  As a method for adding an unsaturated carboxylic acid or an acid anhydride thereof, there is a general method in which a graft reaction is performed by subjecting to a decomposition condition of the radical generator in the presence of the radical generator. A method of adding by dissolving in an organic solvent, adding an unsaturated carboxylic acid or its acid anhydride and a radical generator, and heating with stirring, supplying each component to an extruder and adding while heating and kneading. The method of performing etc. are mentioned.

  The molar ratio of the radical generator to be used and the unsaturated carboxylic acid or acid anhydride thereof (ratio of the radical generator to the unsaturated carboxylic acid or acid anhydride thereof) is usually 1/100 to 3/5, preferably Is 1/20 to 1/2, and the reaction temperature is not particularly limited, but is usually 50 ° C. or higher. The reaction time is usually 2 hours to 10 hours.

  The radical generator used for the graft reaction can be appropriately selected from ordinary radical generators, and examples thereof include organic peroxides. Organic peroxides include diisopropyl peroxide, di (t-butyl) peroxide, t-butyl hydroperoxide, benzoyl peroxide, dicumyl peroxide, cumyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide Methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, diisopropyl peroxycarbonate, dicyclohexyl peroxycarbonate, t-butylperoxyisopropyl monocarbonate, and the like. Among these, di (t-butyl) peroxide, dicumyl peroxide, and t-butyl peroxyisopropyl monocarbonate are preferable.

  Organic solvents used when the grafting reaction is carried out in a dissolved or impregnated state include aromatic hydrocarbons such as benzene, toluene, xylene, aliphatic hydrocarbons such as hexane, heptane, octane, decane, trichloroethylene, perchloro Halogenated hydrocarbons such as ethylene, chlorobenzene, o-dichlorobenzene and the like can be mentioned, among which aromatic hydrocarbons and halogenated hydrocarbons are preferable, and toluene, xylene and chlorobenzene are particularly preferable.

  In the case of producing a modified polypropylene-based resin having an unsaturated dicarboxylic acid monoester as a modifying component, in addition to the method of grafting the unsaturated dicarboxylic acid monoester to the polypropylene main chain as described above, the unsaturated dicarboxylic acid or The anhydride can also be produced by a method in which one of the carboxyl groups is esterified with an aliphatic alcohol and the acid anhydride group is monoesterified using a graft alcohol after grafting to the polypropylene main chain.

  The resin (C) has a crystallinity of 35% to 50%. This is because when the crystallinity is 35% or more, the oil and fat resistance of the coating film does not decrease, and when it is 50% or less, the adhesion between the obtained coating film and the substrate is sufficient.

In the present specification, the method for measuring the crystallinity is as follows:
(Crystallinity)
The stereoregularity [mmmm] of polypropylene was measured by a ¹³ C-NMR spectrum measurement method using an NMR apparatus (manufactured by JEOL Ltd., 400 MHz). 350-500 mg of sample was completely dissolved in about 10 ml of a sample tube for NMR using about 2.2 ml of orthodichlorobenzene. Next, about 0.2 ml of deuterated benzene was added as a lock solvent, and the mixture was homogenized. Then, measurement was performed at 130 ° C. by a complete proton decoupling method. The measurement conditions were a flip angle of 90 ° and a pulse interval of 5T ₁ or more (T ₁ is the longest value of the spin lattice relaxation time of the methyl group). In the propylene-based polymer, since the spin lattice relaxation time of the methylene group and methine group is shorter than that of the methyl group, the recovery of the magnetization of all the carbons is 99% or more under this measurement condition. Measurement was carried out by integrating over 20 hours.

  Chemical shift is the absolute configuration of all methyl branches in 10 types of pentads (mmmm, mmr, rmmr, mmrr, mmrm, rmrr, rmrm, rrrr, rrrr, mrrm) of propylene unit chain consisting of head-to-tail bonds. Set the chemical shift of the peak based on the methyl group of the third unit of the 5 units of propylene units expressed in mmmm that are the same as 21.8 ppm, and determine the chemical shift of the other carbon peak based on this To do. In this standard, for example, in the case of other five propylene units, the chemical shift of the peak based on the methyl group of the third unit is generally as follows. That is, mmmr: 21.5 to 21.7 ppm, rmmr: 21.3 to 21.5 ppm, mmrr: 21.0 to 21.1 ppm, mmrm and rmrr: 20.8 to 21.0 ppm, rmrm: 20.6 to 20.8 ppm, rrrr: 20.3-20.5 ppm, rrrm: 20.1-20.3 ppm, mrrm: 19.9-20.1 ppm.

This polypropylene main chain has the above pentad appearing in the range of 19.8 ppm to 22.2 ppm when the chemical shift of the peak top of the peak attributed to the pentad represented by mmmm is 21.8 ppm. Ratio of peak area S ₁ having a peak top of 21.8 ppm with respect to the total area S of peaks belonging to all pentads of mmmm, mmmr, rmr, mmrr, mmrm, rmrr, rmrm, rrrr, rrrm, mrrm (S ₁ / S) was defined as the crystallinity.

  In the present specification, since the crystallinity is measured by the method described above, the crystallinity of a copolymer of propylene and another monomer means the crystallinity of the polypropylene portion in the resin.

  The mass average molecular weight of the resin (C) is 50,000 to 200,000. This is because when the mass average molecular weight is 50000 or more, the adhesion and oil resistance of the coating film are not lowered, and when the mass average molecular weight is 200000 or less, the production of the aqueous resin is not hindered.

In the present specification, the measurement method of the mass average molecular weight is as follows:
(Mass average molecular weight)
First, 20 mg of a sample was collected in a 30 ml vial, and 20 g of orthodichlorobenzene containing 0.04% by mass of BHT was added as a stabilizer. After dissolving the sample using an oil bath heated to 135 ° C., it was filtered hot with a PTFE (polytetrafluoroethylene) filter having a pore diameter of 3 μm to prepare a sample solution having a polymer concentration of 0.1% by mass. Next, GPC measurement was performed using a Waters GPC150CV equipped with TSKgel GMH-HT (30 cm × 4) and an RI detector as a column. As measurement conditions, the sample solution injection amount: 500 μl, column temperature: 135 ° C., solvent: orthodichlorobenzene, flow rate: 1.0 ml / min were employed. In calculating the molecular weight, a commercially available monodisperse polystyrene was used as a standard sample, and the molecular weight was converted to the polystyrene standard sample.

  The resin (C) preferably has a melting point of 50 ° C. to 90 ° C., more preferably 55 ° C. to 75 ° C., from the viewpoint of oil resistance of the resulting coating film and adhesion to the substrate.

  In this specification, melting | fusing point (degreeC) of the said resin (C) was measured with the differential scanning calorimeter (DSC) (Thermal analyzer SSC5200 (made by Seiko Electronics)).

  The resin (C) preferably has an elongation at 20 ° C. of 400% or more. When the elongation percentage is within the above range, the soft feeling (particularly moist feeling) of the obtained coating film can be improved. The elongation percentage is more preferably 500% or more, and may be 1000% or less as long as it is within the above range.

In this specification, the measuring method of the elongation percentage (%) of the resin is as follows:
A polypropylene plate was coated with a spray gun to a dry film thickness of 25 μm, baked at 60 ° C. for 20 minutes, a test piece having a width of 10 mm and a length of 50 mm was cut out from the obtained polypropylene plate, a temperature of 20 ° C., and a pulling speed The elongation is measured at 50 mm / min. For the measurement, Shimadzu Autograph AG-IS MS manufactured by Shimadzu Corporation is used.

  The method for making the resin (C) aqueous is not particularly limited, and a conventionally known method can be used. For example, a resin solution obtained by adding toluene to the acid anhydride-modified polypropylene produced above and dissolving at about 100 ° C., and then adding a surfactant and stirring forcibly at a temperature of about 50 ° C. to 75 ° C. Examples include a method in which ion-exchanged water at 50 ° C. is dropped to perform phase inversion emulsification, and toluene is then removed under reduced pressure. Further, the acid anhydride-modified polypropylene resin is heated and dissolved in a solvent such as tetrahydrofuran at about 60 ° C., and the carboxyl group of the resin is neutralized with an excess of amine, and then ion-exchanged water at about 60 ° C. is forced. A method may be mentioned in which the solution is added dropwise to the resin solution with stirring, phase transition is performed, and then the solvent is removed under reduced pressure. Furthermore, there is also a method in which an emulsifier and an amine are used in combination with the above solution, and ion-exchanged water at about 60 ° C. is dropped and emulsified with forced stirring, and then the solvent is removed under reduced pressure. Contrary to the above procedure, an acid anhydride-modified polyolefin solution dissolved with the above heating solvent was added dropwise in warm water in which a neutralizing agent such as amine and / or a surfactant was dissolved in water while forcibly stirring, followed by emulsification. A method of removing the solvent under reduced pressure and the like are also included.

  The resin particles (D) used in the interior coating composition of the present invention are used for adjusting the gloss of the resulting coating film.

  The resin particles (D) are preferably at least one selected from the group consisting of acrylic resins, urethane resins, epoxy resins, polyolefin resins (for example, polyethylene), and nylon resins, and are acrylic resins and / or urethane resins. Is more preferable. In addition, the resin particles (D) may be any of these, regardless of whether they are colored, colorless, transparent, or opaque, according to the intended design. Commercially available resin particles can be used.

  The number average particle diameter of the resin particles (D) is preferably 2 μm to 40 μm, more preferably 4 μm to 20 μm, from the viewpoint of the texture of the obtained coating film. The number average particle diameter of the resin particles (D) can be measured using a laser diffraction particle size distribution analyzer.

  In the interior coating composition of the present invention, from the viewpoint of the texture of the coating film obtained, the solid content mass ratio of the resin particles (D) and the total mass of the resins (A), (B) and (C) [( D) / ((A) + (B) + (C))] is preferably 20/100 to 100/100.

  The color pigment (E) used in the interior coating composition of the present invention is used for coloring a coating film obtained from the coating composition black. The interior coating composition of the present invention contains 1% by mass or less of carbon black with respect to the dry coating film mass and a coloring pigment other than carbon black of 5% by mass or more and less than 30% by mass with respect to the dry coating film mass. In the interior coating composition of the present invention, a black colorant can be obtained by a subtractive color mixing method by using a combination of color pigments other than carbon black. In the present invention, the subtractive color mixing method refers to expressing a specific color by mixing color materials.

  Examples of the carbon black that can be used in the interior paint composition of the present invention include furnace black, lamp black, acetylene black, channel black, and the like. Examples thereof include Raven 7000, Raven 5750, Raven. 5250, Raven 5000, Raven 5000 Ultra (ULTRA II), Raven 3500, Raven 2500 Ultra, Raven 2000, Raven 1500, Raven 1255, Raven 1250, Raven 1200, Raven 1190 Ultra II, Raven 1170, Raven 1080 Ultra, Raven 1060 Ultra , Raven 790 Ultra, Raven 780 Ultra, Raven 760 Ultra (above Colombia), Regal 4 0R, Legal 330R, Legal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400 (above, manufactured by Cabot) , Color Black FW1, Color Black FW2, Color Black FW2V, Color Black 18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 , Manufactured by Degussa AG), No. 25, no. 33, no. 40, no. 45, no. 45L, no. 47, no. 52, no. 900, no. 960, no. Commercial products such as 2300, MCF-88, MA600, MA7, MA8, MA100 (above, manufactured by Mitsubishi Chemical Corporation) can be used. Carbon black can be used alone or in combination of two or more.

In the present invention, DBP oil absorption of carbon black is, for example, ^{50ml / cm 3 ~150ml / cm 3} .

  In the interior coating composition of the present invention, the content (PWC) of carbon black with respect to the dry coating mass (PWC) is 1% by mass or less, preferably 0.5% by mass or less, and particularly preferably, the coating composition is Does not contain carbon black. Thereby, the coating film obtained from the interior coating composition of the present invention has a sufficient hue and hiding power, and is excellent in oil and fat resistance, light resistance and adhesion.

The color pigments other than carbon black that can be used in the interior paint composition of the present invention have a lightness L ^* value of the coating film obtained from the paint composition of 20 to 30, and a hiding power of black and white hiding test paper of 10 μm. It is selected to be ˜20 μm. In the present invention, the hiding power in the black-and-white hiding test paper refers to the hiding power test as defined in JIS K5600-4-1, in which the black-and-white boundary is measured visually after coating and baking the coating composition by changing the film thickness. It means the film thickness that cannot be distinguished. Examples of coloring pigments other than carbon black include purple pigments, red pigments, yellow pigments, green pigments, white pigments, blue pigments, and black pigments other than carbon black. Coloring pigments other than carbon black can be used alone or in combination of two or more, preferably in combination of four or more.

  The purple pigment is not particularly limited, and examples thereof include cobalt purple, quinacridone violet, and dioxazine violet.

  The red pigment is not particularly limited, and examples thereof include iron oxide red, naphthol AS azo red, ansanthrone, anthraquinonyl red, perylene maroon, quinacridone red pigment, diketopyrrolopyrrole, watching red, permanent red, and the like. Among them, iron oxide red and diketopyrrolopyrrole are preferable.

  The yellow pigment is not particularly limited, for example, iron oxide yellow, titanium yellow, monoazo yellow, condensed azo yellow, azomethine yellow, bismuth vanadate, benzimidazolone, isoindolinone, isoindoline, quinophthalone, benzidine yellow, Permanent yellow and the like can be mentioned, and iron oxide yellow is preferable.

  The green pigment is not particularly limited, and examples thereof include phthalocyanine green.

  The white pigment is not particularly limited, and examples thereof include titanium dioxide.

  The blue pigment is not particularly limited, and examples thereof include cobalt blue, phthalocyanine blue, and selenium blue.

  Examples of black pigments other than carbon black include, but are not limited to, iron oxide black and aniline black.

  Preferred combinations of colored pigments other than carbon black are purple pigment, red pigment, yellow pigment and green pigment combination, purple pigment, red pigment, yellow pigment, green pigment and white pigment combination, and purple pigment, red pigment, yellow A combination of a pigment, a green pigment, a white pigment and a blue pigment.

  For example, when a combination of a purple pigment, a red pigment, a yellow pigment, and a green pigment is used as the color pigment other than carbon black, a purple pigment: a red pigment: a yellow pigment: a green pigment = 5 to 15: 5 to 15: 5 to 15 : When used in a mass ratio of 55 to 85 and using a combination of purple pigment, red pigment, yellow pigment, green pigment and white pigment, purple pigment: red pigment: yellow pigment: green pigment: white pigment = 5-10: When used in a mass ratio of 5 to 10: 5 to 10:40 to 50:25 to 35, and a combination of purple pigment, red pigment, yellow pigment, green pigment, white pigment and blue pigment is used, purple pigment: red pigment : Yellow pigment: Green pigment: White pigment: Blue pigment = Used in a mass ratio of 5-10: 5-10: 5-10: 30-60: 10-40: 3-15.

  In the interior coating composition of the present invention, the content (PWC) of the color pigment other than carbon black with respect to the dry coating film mass is 5% by mass or more and less than 30% by mass, preferably 5% by mass to 15% by mass. is there. When the PWC of the color pigment other than carbon black is within this range, the resulting coating film is excellent in oil resistance, light resistance and adhesion to the substrate.

  In the interior coating composition of the present invention, the content (PWC) of the color pigment (E) with respect to the dry coating mass is, for example, 5% by mass or more, and the resulting coating exhibits a sufficient black hue. From the viewpoint, it is preferably 10% by mass or more.

  In one embodiment of the present invention, when the color pigment other than carbon black includes a combination of a red pigment, a yellow pigment, and a white pigment, the red pigment is iron oxide red, the yellow pigment is iron oxide yellow, and white The pigment is preferably titanium oxide, and the total mass of the red pigment, the yellow pigment and the white pigment is preferably 20% by mass or more based on the total mass of the colored pigment.

  The interior coating composition of the present invention may contain other components as required within a range not impairing the effects of the present invention. The component that can be contained is not particularly limited, and examples thereof include resins other than the above (A) to (C), surface conditioners, anti-settling agents, matting agents, ultraviolet absorbers, light stabilizers, and antioxidants. Agents, waxes, film-forming aids, crosslinking agents, thickeners, antifoaming agents and the like.

  The interior coating composition of the present invention comprises the resin (A), (B) and (C), the resin particle (D), the color pigment (E), and other components as necessary. It can also be obtained by stirring and mixing in order, and the resin particles (D) and / or the color pigment (E) can be added to the aqueous dispersion obtained by mixing the above (A) to (C) as necessary. It can also be obtained by adding a dispersion dispersed with the above components.

  The resin particles (D) and / or the color pigment (E) can be used by being dispersed in a resin such as a water-soluble acrylic resin, for example. The water-soluble acrylic resin used for dispersing the resin particles (D) and / or the color pigment (E) is not particularly limited as long as it has a structural unit derived from an acrylic monomer as an essential component. Examples of the acrylic monomer include (meth) acrylic acid ester monomers such as acrylic acid, methacrylic acid, and (meth) acrylic monomers.

The coating film formed from the interior coating composition of the present invention has a lightness L ^* value of 20 to 30 of the dried coating film. The lightness L ^* value can be measured by, for example, a color difference meter (manufactured by Konica Minolta: CR-400).

  The coating film formed from the interior coating composition of the present invention has a hiding power of 10 μm to 20 μm on a black and white hiding test paper.

The coating film formed from the interior coating composition of the present invention having the lightness L ^* value and the hiding power in the black-and-white hiding test paper contains more than 1% by mass of carbon black with respect to the dry coating mass. A black hue equivalent to that of a coating film obtained from the coating composition can be exhibited.

  The interior coating composition of the present invention can be used for various plastic substrates and molded articles thereof, but is suitable for polyolefin substrates such as polypropylene, plastic substrates such as ABS resin and polycarbonate, and molded articles thereof. And can be particularly preferably used for polyolefin-based substrates such as polypropylene and molded articles thereof.

  When coating with the coating composition of the present invention, it is not necessary to apply a primer to the substrate before coating, and after wiping the substrate with alcohol or the like, the coating composition of the present invention is directly applied on the substrate. Can be painted and baked and dried. In addition, it is also possible to perform the coating with the coating composition of the present invention after coating the primer.

  The method for applying the interior coating composition of the present invention to the substrate is not particularly limited, and examples thereof include spray coating, roll coater method, bell coating, disk coating, curtain coating, shower coating, spin coating, brush coating, and the like. Usually, it can coat in the range of 10 micrometers-50 micrometers of dry film thickness. Between the coating and the baking and drying, it may be set by leaving it at room temperature (room temperature) for an appropriate time.

  The baking drying is preferably performed by heating. Further, even when baking and drying are performed by the above heating, it is not necessary to cause a curing reaction, and it is sufficient if the surface of the resin is melted and adheres to the base material, and thus can be performed by heating at a low temperature. . The said heating should just be 50 degreeC or more, for example, and can be performed on conditions, such as 5 minutes-60 minutes.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to these examples. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

1. Preparation of Pigment Paste Production Example 1: Synthesis of Water-soluble Acrylic Resin for Pigment Paste 55 parts of propylene glycol monomethyl ether was charged into a reaction vessel equipped with a stirring blade, a dropping device, a temperature control device, a nitrogen gas introduction tube and a cooling tube, While introducing the gas, the temperature was raised to 120 ° C. with stirring.

  Next, a monomer solution consisting of 12 parts of 2-hydroxyethyl methacrylate, 9 parts of methacrylic acid, 35 parts of isobutyl methacrylate and 44 parts of n-butyl acrylate, 1 part of t-butyl peroxy-2-ethyl hexanate and propylene glycol monomethyl A solution consisting of 4 parts of ether was added dropwise to the reaction vessel over 2 hours.

  After completion of dropping, the mixture was aged at 120 ° C. for 2 hours with stirring, then the internal temperature was cooled to 70 ° C., 9.5 parts of dimethylaminoethanol was added dropwise, and the mixture was further stirred for 30 minutes.

  While maintaining the internal temperature at 70 ° C., 167 parts of ion exchange water was gradually added dropwise and cooled to 25 ° C. to obtain a water-soluble acrylic resin solution. The obtained water-soluble acrylic resin solution had a solid content of 30% and a pH of 8.1, and the mass average molecular weight of the acrylic resin was 42,000.

Production Example 2: Preparation of Black Pigment Paste 35 parts of the water-soluble acrylic resin of Production Example 1 above was charged in a stainless steel container equipped with a stirrer, and 36 parts of deionized water and carbon black (Raven 5000; trade name, Colombia) while stirring. 10.5 parts, 18 parts of pigment dispersant (EFKA4550; trade name, manufactured by Efka), and 0.5 part of antifoaming agent (BYK-011; trade name, manufactured by Big Chemie) were sequentially charged to make the mixture uniform. After sufficiently stirring for 30 minutes to prepare a mill base, a black pigment was dispersed with a sand grind mill to produce a black pigment paste (non-volatile content 30%, pigment concentration (PWC) 35%).

Production Example 3: Preparation of White Pigment Paste A stainless steel container equipped with a stirrer was charged with 10.9 parts of the water-soluble acrylic resin of Production Example 1 and 15.3 parts of deionized water, and stirred with titanium dioxide (CR-97; (Product name, manufactured by Ishihara Sangyo Co., Ltd.) 65.6 parts, Dispersant (DUSPERBYK 190; product name, manufactured by Big Chemie, solid content 40% by mass), 8.2 parts, charged, and stirring was continued until it became uniform for 30 minutes. To get a mill base. Next, the white pigment was dispersed with the same disperser (sand grind mill) as used in Production Example 2 to obtain a white pigment paste (non-volatile content: 72% by mass, PWC: 91%).

Production Example 4: Preparation of Green Pigment Paste 56.87 parts of the water-soluble acrylic resin of Production Example 1 and 25.76 parts of deionized water were charged into a stainless steel container equipped with a stirrer, and Lionol Green 6YKP-N17. 07 parts (manufactured by Toyo Ink Manufacturing Co., Ltd.), 0.30 part of antifoaming agent (BYK 011; trade name, manufactured by Big Chemie, solid content: 40% by mass) were charged, and stirring was continued until 30 minutes were uniform, A mill base was obtained. Next, the green pigment was dispersed in the same disperser (sand grind mill) as that used in Production Example 2 to obtain a green pigment paste (non-volatile content: 34% by mass, PWC: 50%).

Production Example 5: Preparation of yellow pigment paste A stainless steel container equipped with a stirrer was charged with 58.17 parts of the water-soluble acrylic resin of the above Production Example 1 and 15.65 parts of deionized water, and stirred with iron oxide yellow (Tarox LL- XLO (trade name, manufactured by Titanium Industry Co., Ltd.) 26.18 parts was charged, and stirring was further continued until it became uniform for 30 minutes to obtain a mill base. Next, the yellow pigment was dispersed with the same disperser (sand grind mill) as that used in Production Example 2 to obtain a yellow pigment paste (non-volatile content: 44 mass%, PWC: 60%).

Production Example 6: Preparation of red pigment paste 1 In a stainless steel container equipped with a stirrer, 27.10 parts of the water-soluble acrylic resin of Production Example 1 and 42.23 parts of deionized water were charged, and while stirring, Irgazin DPP RUBINE TR (BASF 19.00 parts, defoaming agent (BYK-011; trade name, manufactured by Big Chemie) 0.30 parts, pigment dispersant (EFKA4550; trade name, manufactured by Efka) 11.39 parts, and charged for 30 minutes Stirring was further continued until uniform, and a mill base was obtained. Subsequently, the red pigment was dispersed using the same disperser (sand grind mill) as that used in Production Example 2 to obtain a red pigment paste (nonvolatile content: 33% by mass, PWC: 58%).

Production Example 7: Preparation of Red Pigment Paste 18. A stainless steel container equipped with a stirrer was charged with 18.81 parts of the water-soluble acrylic resin of Production Example 1 and 62.00 parts of deionized water. Rocks 120FS; trade name, manufactured by Bayer Japan) 19.00 parts, defoaming agent (BYK-011; trade name, manufactured by Big Chemie) 0.19 parts, and stirring was continued for 30 minutes until uniform. To get a millbase. Subsequently, the red pigment was dispersed using the same disperser (sand grind mill) as that used in Production Example 2 to obtain a red pigment paste (non-volatile content: 24.70% by mass, PWC: 77%).

Production Example 8: Preparation of blue pigment paste A stainless steel container equipped with a stirrer was charged with 20.65 parts of the water-soluble acrylic resin of Production Example 1 and 15.24 parts of deionized water and stirred with cyanine blue G-314 (Sanyo). Pigment) (54.94 parts), pigment dispersant (EFKA4550; trade name, manufactured by Efka) 8.67 parts, antifoaming agent (BYK-011; trade name, manufactured by Big Chemie) 0.50 parts, 30 Stirring was further continued until uniform for a minute to obtain a mill base. Subsequently, the blue pigment was dispersed with the same disperser (sand grind mill) as that used in Production Example 2 to obtain the blue pigment paste (nonvolatile content 61% by mass, PWC 90%).

Production Example 9: Preparation of purple pigment paste A stainless steel container equipped with a stirrer was charged with 15.24 parts of the water-soluble acrylic resin of Production Example 1 and 15.24 parts of deionized water and stirred with Hoster Palm Violet BL-W ( (Clariant Co., Ltd.) 16.00 parts and antifoaming agent (BYK-011; trade name, Big Chemie Co., Ltd.) 0.16 parts were charged, and stirring was further continued for 30 minutes to obtain a mill base. Next, the purple pigment was dispersed in the same disperser (sand grind mill) as that used in Production Example 2 to obtain a purple pigment paste (nonvolatile content: 23 mass%, PWC: 68%).

2. Production and production example of aqueous chlorinated polyolefin-modified acrylic resins B-1 to B-3: Production of aqueous chlorinated polyolefin-modified acrylic resin B-1 Agitated blades, thermometer, dropping device, temperature control device and cooling pipe were attached. In a reaction apparatus, polyolefin resin hardene 14LWP (manufactured by Toyo Kasei Kogyo Co., Ltd., solid content 100%, chlorine content 27%, weight average molecular weight 60000) 25 parts, methyl methacrylate 13.5 parts, 2-hydroxyethyl methacrylate 4. 5 parts, 72.0 parts of isobutyl methacrylate, 20 parts of Emulgen 920 (manufactured by Kao Corporation, nonionic surfactant, solid content 100%) and 30 parts of toluene were sequentially added, and the temperature was gradually raised to 100 ° C. and stirred for 30 minutes. To obtain a homogeneous solution. Next, after cooling the internal liquid temperature to 50 ° C., 1.5 parts of azobisbutyronitrile was dissolved in 10 parts of methyl methacrylate and added dropwise to the reaction vessel with stirring. Subsequently, 350 parts of ion-exchanged water was added dropwise over 30 minutes while stirring the interior at 1000 rpm to prepare an emulsion. The emulsion was heated to 85 ° C. with stirring at 150 rpm and reacted for 3 hours.

  Next, after cooling, detoluene operation is performed under reduced pressure, and after adjusting by adding a little ion exchange water, etc., an aqueous chlorinated polyolefin-modified acrylic resin B-1 having a solid content of 30% and an average particle size of 0.28 μm is obtained. It was.

Production Example 2: Production of Aqueous Chlorinated Polyolefin Modified Acrylic Resin B-2 and B-3 Similar to the production of the above aqueous chlorinated polyolefin modified acrylic resin B-1, the aqueous chlorinated polyolefin modified with the formulation shown in Table 1 Acrylic resins B-2 and B-3 were obtained. The properties of each resin are shown in Table 1.

3. 3. Production of aqueous maleic anhydride-modified polypropylene resins C-1 to C-4 3-1. Production Production Example 1 of Polypropylene Resin PO-1 to PO-4 1: Production of Polypropylene Resin PO-1 In a 1000 ml round bottom flask, 110 ml of deionized water, 22.2 g of magnesium sulfate heptahydrate and 18.2 g of sulfuric acid. Was collected and dissolved under stirring. In this solution, 16.7 g of commercially available granulated montmorillonite was dispersed, heated to 100 ° C., and stirred for 2 hours. Then, it cooled to room temperature and filtered the obtained slurry, and collect | recovered the wet cake. The recovered cake was slurried again with 500 ml of demineralized water in a 1000 ml round bottom flask and filtered. This operation was repeated twice. The finally obtained cake was dried at 110 ° C. overnight under a nitrogen atmosphere to obtain 13.3 g of chemically treated montmorillonite.

  To 4.4 g of the obtained chemically treated montmorillonite, 20 ml of a toluene solution of triethylaluminum (0.4 mmol / ml) was added and stirred at room temperature for 1 hour. To this suspension was added 80 ml of toluene, and after stirring, the supernatant was removed. After repeating this operation twice, toluene was added to obtain a clay slurry (slurry concentration = 99 mg clay / ml).

  In a separate flask, 0.2 mmol of triisobutylaluminum was collected, and 19 ml of the clay slurry obtained here and dichloro [dimethylsilylene (cyclopentadienyl) (2,4-dimethyl-4H-5,6,7,8 -Tetrahydro-1-azulenyl)] Hafnium 131 mg (57 μmol) in toluene was added and stirred at room temperature for 10 minutes to obtain a catalyst slurry.

  Next, 11 L of toluene, 3.5 mmol of triisobutylaluminum, 2.48 L of liquid propylene and 0.16 L of liquid ethylene were introduced into an induction stirring autoclave having an internal volume of 24 liters. The whole amount of the catalyst slurry was introduced at room temperature, the temperature was raised to 50 ° C., and the stirring was continued for 2 hours at the same temperature while keeping the total pressure during polymerization at 0.5 MPa and the hydrogen concentration at 400 ppm. After completion of the stirring, unreacted propylene was purged to terminate the polymerization. The autoclave was opened to collect the whole amount of the toluene solution of the polymer, and the solvent and the clay residue were removed. As a result, 11 kg (1.98 kg ethylene-propylene copolymer) of 18 mass% ethylene-propylene copolymer (PO-1) toluene solution was removed. Polymer). The resulting polypropylene resin PO-1 had a weight average molecular weight Mw of 300000 (polystyrene conversion value) and a crystallinity of the polypropylene (PP) part of 40%.

Production Example 2: Production of polypropylene resins PO-2 to PO-4 Polypropylene resins PO-2 to PO-2 in the same manner as PO-1 in Production Example 1 except that the polymerization conditions were changed as shown in Table 2. -PO-4 was produced. The properties of each resin are shown in Table 2.

3-2. Production Production Example 1 of Maleic Anhydride Modified Polypropylene Resins POM-1 to POM-4 Production of Maleic Anhydride Modified Polypropylene Resin POM-1 In a glass flask equipped with a reflux condenser, a thermometer and a stirrer, the above-mentioned 400 g of polypropylene resin PO-1 and 600 g of toluene were added, the inside of the container was replaced with nitrogen gas, and the temperature was raised to 110 ° C. After heating, 100 g of maleic anhydride was added, 30 g of t-butyl peroxyisopropyl monocarbonate (manufactured by NOF Corporation, Perbutyl I (PBI)) was added, and the reaction was continued for 7 hours at the same temperature. After completion of the reaction, the system was cooled to around room temperature, acetone was added, and the precipitated polymer was filtered off. Further, precipitation and filtration were repeated with acetone, and the finally obtained polymer was washed with acetone. The polymer obtained after washing was dried under reduced pressure to obtain a white powdery maleic anhydride-modified polypropylene resin POM-1. As a result of measuring the infrared absorption spectrum of this modified polymer, the content (graft ratio) of maleic anhydride groups was 3.6% by mass (0.36 mmol / g). The weight average molecular weight Mw was 100,000.

Production Example 2: Manufacture of Maleic Anhydride Modified Polypropylene Resins POM-2 to POM-4 Manufacture of POM-1 of Production Example 1 except that the polypropylene resin used and the blending were changed as shown in Table 3 In the same manner as in Examples, maleic anhydride-modified polypropylene resins POM-2 to POM-4 were produced. The properties of each resin are shown in Table 3.

3-3. Production and Production Example 1 of Aqueous Maleic Anhydride Modified Polypropylene Resin C-1 to C-4 Production of Aqueous Maleic Anhydride Modified Polypropylene Resin C-1 Agitating blade, thermometer, dropping device, temperature control device and cooling pipe To the attached reactor, 100 g of POM-1 prepared in Production Example 1 of 3-2 above and 200 g of toluene were added, and the mixture was heated to 100 ° C. to dissolve and cooled to 70 ° C. Thereafter, 15 g of nonionic surfactant Emulgen 220 (manufactured by Kao, HLB = 14.2, solid content 100%) and 15 g of nonionic surfactant Emulgen 147 (manufactured by Kao, HLB = 16.3, solid content 100%) were added. And dissolved to 50 ° C. While maintaining the temperature at 50 ° C., 520 g of ion-exchanged water was added little by little to perform phase inversion emulsification.

  Then, after cooling to room temperature and adding 2-amino-2-methyl-1-propanol to adjust to pH = 8, detoluene operation was performed under reduced pressure, and the mixture was prepared with some ion-exchanged water and had a solid content of 20 % Aqueous POM-1 dispersion was obtained. The average particle size of this aqueous dispersion was 0.32 μm.

Production Example 2: Production of aqueous maleic anhydride-modified polypropylene resin C-2 to C-4 Aqueous anhydrous as in C-1 of Production Example 1 except that the blending amount was changed as shown in Table 4. Maleic acid-modified polypropylene resins C-2 to C-4 were produced. The properties of each resin are shown in Table 4.

Example 1
Adekabon titer HUX561 (manufactured by ADEKA) 63.6 g (solid content 40%), aqueous chlorinated polyolefin-modified acrylic resin B-1 33.9 g (solid content 30%), aqueous maleic anhydride-modified polypropylene resin C-1 76.3 g (20% solid content) was sequentially added to the container while stirring and stirred uniformly. Next, 2.5 g (100% solid content) of Polyflow KL245 (manufactured by Kyoeisha Chemical Co., Ltd.) and 10.0 g of butyl cellosolve were added and stirred.

  Further, 30.0 g of Art Pearl C800 transparent (manufactured by Negami Kogyo Co., Ltd.) was added little by little, and then stirred and dispersed uniformly.

  Subsequently, 5.8 g of the white pigment paste, 32.0 g of the green pigment paste, 6.1 g of the purple pigment paste, 4.5 g of the red pigment paste 2 and 3.5 g of the yellow pigment paste prepared previously are added and stirred uniformly. After dispersion, 1.8 g of Primal ASE 60 (Rohm and Haas) (solid content 28.0%) and 10.0 g of ion-exchanged water were added to obtain a coating composition. The solid content of the paint was 37%.

(Example 2-11 and Comparative Example 1-10)
A coating composition was obtained in the same manner as in Example 1 except that the amount was changed as shown in Tables 5 and 6. However, for Example 6, Example 9, and Comparative Example 8, aqueous maleic anhydride-modified polypropylene resin C-1 was replaced with C-3 (Example 6), C-2 (Example 9), and C-, respectively. 4 (Comparative Example 8), for Example 10 and Example 11, aqueous chlorinated polyolefin-modified acrylic resin B-1 was replaced with B-2 (Example 10) and B-3 (Example 11), respectively. ).

[Preparation of test piece]
<Coating method>
Each of the coating compositions obtained in Example 1-11 and Comparative Example 1-10 was spray-coated on a polypropylene substrate having a size of 150 mm × 70 mm × 3 mm, left at room temperature for 5 minutes, and 20 ° C. at 20 ° C. By partial baking, a test piece having a dry film thickness of 25 μm was obtained. The obtained test piece was evaluated based on the following criteria.

<L value measurement>
Measured with CR400 (manufactured by Konica Minolta).

<Hiding power>
Measurements were made using black and white concealment test paper. Specifically, the film thickness was changed to a masking rate test test (black and white masking test) defined in JIS K5600-4-1, and after coating and baking, the film thickness at which the black and white boundary could not be visually determined was measured. A film thickness of 10 μm to 20 μm at which the black-and-white boundary could not be identified was rated as “◯”, and a film thickness larger than 20 μm was marked as “X”.

<Initial adhesion>
Using a cutter knife, make a 2 mm wide vertical / horizontal cut on the coating film to form a 100-th mesh, adhere an adhesive tape on it, lift one end of the tape and peel it upward. This peeling operation is carried out five times at the same location, and the number of square meshes in which the coating film is peeled off by 50% or more in the area of 1 square is shown. 0 was accepted (O), and 1 or more was rejected (X).

<Moisture resistance>
The test piece is allowed to stand for 240 hours in an atmosphere having a temperature of 50 ± 2 ° C. and a humidity of 98 ± 2%, and the surface of the coating film is observed and a cross-cut adhesion test is performed within 1 hour. The cross-cut adhesion test is a cutter knife. A vertical and horizontal cut with a width of 2 mm is made on the coating film to form a 100-th cut, and an adhesive tape is stuck on it, and one end of the tape is lifted upward. Remove. This peeling operation was carried out five times at the same location, and peeling was performed when the coating film was peeled off by 50% or more in the first square:
○: No abnormality is observed on the surface of the coating film, and no peeling is observed in the cross-cut adhesion test. X: Abnormality is observed on the coating film surface, or peeling is recognized in the cross-cut adhesion test.

<Oil resistance>
4 g / 100 cm ² of beef tallow is spread evenly on the surface of the test piece. Place a slightly smaller cloth on the test piece and leave it in an electric furnace without forced convection set at 80 ° C. for one week. Remove after specified time and wash with water so that the adhesive tape adheres sufficiently.
An adhesion test by cross-cutting was performed. “No peeling” was indicated by (◯), “Peeling” was indicated by (×), and “Slightly peeling along the cross-cut line” was indicated by (Δ).

<Light resistance>
Evaluate xenon light resistance, color difference ΔE before and after the test with a fade meter, and the appearance of the coating:
○: Color difference ΔE is 2 or less, no significant appearance abnormality on the coated surface ×: Color difference ΔE is 2 or more, or significant appearance abnormality is on the painted surface

  The results are shown in Table 6.

  From Table 6, when the coating composition of Example 1-11 was used, a coating film excellent in adhesion, oil resistance and scratch resistance could be obtained, but the coating composition of Comparative Example 1-10 was used. If it was, no excellent performance was obtained.

  The interior coating composition of the present invention can be suitably used for various plastic substrates and molded articles thereof.

Claims (1)

An interior coating composition comprising an aqueous urethane resin (A), an aqueous chlorinated polyolefin-modified acrylic resin (B), an aqueous polyolefin resin (C), resin particles (D), and a color pigment (E),
The amount of the resin (C) relative to the total mass of the resins (A), (B) and (C) is 15% by mass to 50% by mass,
The solid content mass ratio [(A) / (B)] of the resins (A) and (B) is 90/10 to 50/50,
The elongation at 20 ° C. of the resin (A) is 100% or more,
The chlorinated polyolefin modification amount of the resin (B) is 5% by mass to 40% by mass,
Resin (C) is a non-chlorinated aqueous polypropylene resin, the crystallinity is 35% to 50%, and the mass average molecular weight is 50,000 to 200,000.
The carbon black content of the color pigment (E) is 1% by mass or less with respect to the dry coating film mass, and the content of the color pigment other than carbon black is 5% by mass or more and less than 30% by mass with respect to the dry coating film mass. And
A coating composition for interiors, wherein the lightness L ^* of a coating film formed from the coating composition is 20 to 30, and the hiding power of the black-and-white hiding test paper is 10 μm to 20 μm.