JP5828717B2 - Pigment dispersion resin solution, pigment dispersion, and toning paint or primary color paint - Google Patents

Description

  The present invention relates to a resin solution for pigment dispersion, a pigment dispersion, and a toning paint or primary color paint. More specifically, the present invention has excellent pigment dispersibility and color tone when dissolved in a weak solvent such as mineral spirit. Resin for pigment dispersion capable of preparing toning paint or primary color paint excellent in stability and color tone stability over time, pigment dispersion using the same, and pigment dispersion obtained using the pigment dispersion The present invention relates to a toning paint or primary color paint having excellent properties, color tone stability, and color tone stability over time.

  In general, a paint containing a color pigment (also referred to as a paint composition) includes a pigment dispersion (also referred to as a mill base) in which an inorganic pigment or an organic pigment is dispersed at a relatively high concentration in a pigment dispersion resin, and a coating film. Binder resin (for example, alkyd resin type, acrylic resin type, epoxy resin type, amino resin type, silicone resin type, fluororesin type, etc.) that is the main element, and any proportions of solvents and additives as required It is obtained by mixing with. Therefore, the pigment dispersing resin is required to have excellent pigment dispersibility and good compatibility with various binder resins used in paints. Normally, the resin for pigment dispersion used a resin system similar to the binder resin in the paint in consideration of compatibility, color stability, etc. Therefore, a dedicated pigment dispersion is prepared for each paint to be toned. It was. In other words, it is necessary to prepare a pigment dispersion for toning according to the type of paint and the number of colors. For this reason, the number of pigment dispersions to be prepared is inevitably increased, resulting in production efficiency and manufacturing cost. This is one of the factors that put a great load on the storage location, inventory turnover rate, and the like.

  In addition, in the recent paint industry, the supply of small quantities of various types of paints that meet customer needs has become an eternal theme that cannot be avoided. The utility value of pigment dispersions has become very high. In addition, paints are used in various painting environments according to customer needs, and can be applied in various ways with different market shares, such as brush painting, roller painting, air spray painting, airless spray painting, dip painting, and electrostatic painting. It is painted. For this reason, even with the same paint, a serious problem such as a color difference or color break often occurs in the formed coating film due to a difference in share due to a difference in a painting method. Examples of pigment dispersion resins that have been put on the market in the past include a low molecular weight type having a number average molecular weight of less than 700 and a high molecular weight type having a number average molecular weight of 700 or more. Examples of the low molecular weight type include various paint binders. Resins having good compatibility with resin systems (for example, urea resins, triazine resins, polyglycol resins, acrylic resins, etc.) have been known, but these low molecular weight resins are solvent resistant to the resulting coating film. In many cases, the properties, water resistance, and adhesion to the substrate were impaired.

  Based on such a background, a high-molecular-weight pigment dispersion resin for toning that can be used in common for several kinds of paints has been proposed. For example, a polyester resin (cited document 1), a urethane-modified polyester resin (cited document 2), an acrylic resin (cited documents 3, 4 and 5) and the like have been proposed. However, most polyester resins are pigment dispersion resins that have basicity, and appropriate functional groups are not applied to all pigments. It is done. With urethane-modified polyester resins, there are concerns about color tone stability (especially seeding and color fading) when used in various types of paints. The acrylic pigment dispersing resins described in the cited references 3 and 4 have acid-base or base as a functional group and a composition balance is defined, but any resin is used for all pigments. Appropriate functional groups are not applied. On the other hand, the acrylic pigment dispersing resin described in the cited document 5 shows good compatibility with various binder resins. However, when a pigment dispersion using these is applied to various paints, It has also been confirmed that there is a problem in the color tone stability due to the difference in pigment dispersibility, and this adversely affects the resulting coating film performance.

  As a pigment dispersing resin that solves the above problems, the pigment dispersing resin described in the cited reference 6 has been reported, and the pigment dispersion and paint produced using this pigment dispersing resin are very excellent. Color tone stability and color tone stability over time are shown.

Japanese Patent No. 3038854 Japanese Patent No. 3141422 Japanese Patent No. 3272824 Japanese Patent No. 4264161 Japanese Patent No. 3049407 Japanese Patent No. 3584238

  By the way, in the recent paint industry, it has the advantages that it is less toxic than strong solvent paints, has high safety in operation, and has little influence on air pollution. Conversion to is required.

  However, not only various resins described in Patent Documents 1 to 5, but also pigment dispersions described in Patent Document 6 exhibiting very excellent color tone stability and color tone temporal stability as described above in strong solvent paints. Even in the case of a resin, when dissolved in a weak solvent such as mineral spirit, the dispersion stability of the pigment may not be as excellent as in the case of a strong solvent such as xylene or toluene. When the dispersion stability of the pigment is lowered, the color tone aging stability of the generally prepared paint is lowered. Thus, in order to meet the demand for conversion to a weak solvent-based paint using a weak solvent having the above-mentioned advantages, there is a demand for a pigment dispersion resin that exhibits excellent pigment dispersion stability even in a weak solvent-based paint. ing.

  Accordingly, the present invention prepares a toning paint or a primary color paint having excellent pigment dispersibility and excellent color tone stability and color temporal stability when dissolved in a weak solvent such as mineral spirit. Resin for pigment dispersion, pigment dispersion using the same, and toning paint or primary color paint excellent in pigment dispersibility, color tone stability, and color tone stability obtained by using this pigment dispersion The purpose is to provide.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved by using an acrylic resin or modified acrylic resin having specific characteristics as a resin for dispersing pigments. It has been reached. That is, the present invention is a pigment dispersion resin solution containing an acrylic resin or a modified acrylic resin and a weak solvent, and the acrylic resin or the modified acrylic resin has a number average molecular weight of 2,000 to 14,000, an acid value and an amine. At least one of the valences is 0.1 to 15 mg KOH / g, has a hydroxyl value of 0 to 15 mg KOH / g, and further represents a polymerizable group represented by the following general formula (I) with respect to the total mass of the constituent monomers. 1 0 to 35% by weight saturated monomers, and the SP value of a homopolymer is 9.2 or less (meth) by copolymerizing constituent monomer which contains less than 1 5% by weight or more and 90 wt% acrylic acid ester monomer It is a resin solution for pigment dispersion characterized by being manufactured .

However, in the general formula (I), R ₁ is hydrogen or a methyl group, R ₂ is an ethylene or propylene group, R ₃ is an alkyl group or a phenyl group having 1 to 4 carbon atoms, n represents 1 It is an integer of ~ 4.

  Further, the present invention is a pigment dispersion characterized by containing the pigment dispersion resin solution and the pigment according to the present invention, and the toning paint or primary color paint characterized by containing this pigment dispersion It is.

Since the resin solution for pigment dispersion according to the present invention is a resin solution for pigment dispersion containing the acrylic resin or modified acrylic resin and a weak solvent, which have the above-mentioned properties and is produced by copolymerizing the constituent monomers, a strong solvent The pigment can be dispersed with high dispersion stability even in a weak solvent that has low toxicity and high work safety compared to paints, and has little impact on air pollution. A toning paint or primary color paint having excellent color tone stability over time can be prepared. The pigment dispersion according to the present invention contains the resin solution for pigment dispersion according to the present invention, and the toning paint or primary color paint according to the present invention contains the pigment dispersion according to the present invention. Therefore, according to the present invention, when it is dissolved in a weak solvent such as mineral spirit, a toning paint or primary color paint having excellent pigment dispersibility and excellent color tone stability and color tone stability over time. Resin for pigment dispersion that can be prepared, pigment dispersion using the same, and toning paint or primary color paint excellent in pigment dispersibility, tone stability, and tone stability over time obtained by using the pigment dispersion Can be provided.

  Hereinafter, the present invention will be described in detail. First, the pigment dispersion resin of the present invention will be described. The acrylic resin or modified acrylic resin, which is the resin for dispersing pigments of the present invention, is an acrylic resin or modified acrylic resin having the above characteristics and the constituent monomers. Specifically, the acrylic resin or modified acrylic resin of the present invention has a number average molecular weight of 2,000 to 14,000, preferably 3,000 to 12,000. If the number average molecular weight is less than 2,000, the water resistance of the coating film formed by the toned paint may decrease, which is not preferable as the pigment dispersing resin contained in the pigment dispersing resin solution. A person skilled in the art can easily understand the idea that the water resistance and the like of the coating film formed by the toned paint is not preferable as the resin solution for pigment dispersion. On the other hand, when the number average molecular weight exceeds 14,000, the pigment dispersibility is lowered, and separation or precipitation due to aggregation of the pigment is likely to occur during storage of the paint, and the color tone stability over time may be lowered. It is not preferable. The number average molecular weight of the acrylic resin or modified acrylic resin can be measured by a conventional method, and a specific measuring method will be described later. The number average molecular weight of the acrylic resin or modified acrylic resin can be adjusted by a known appropriate method.

  The acrylic resin or modified acrylic resin of the present invention has an acid value and / or an amine value of 0.1 to 15 mgKOH / g. That is, when the acrylic resin or modified acrylic resin of the present invention has an acid group (that is, except when the acid value is 0 mgKOH / g), the acid value is 0.1 to 15 mgKOH / g, and the amino group The amine value is 0.1 to 15 mgKOH / g (excluding the case where the amine value is 0 mgKOH / g). If both the acid value and the amine value are less than 0.1 mgKOH / g, the pigment dispersibility is lowered, long-time kneading is required, and color tone stability over time may be further lowered, which is not preferable. . On the other hand, if at least one of the acid value and the amine value exceeds 15 mgKOH / g, the color tone stability tends to be lowered, and seeding tends to occur depending on the paint type to be toned, which is not preferable. That is, by using an acrylic resin or a modified acrylic resin in which at least one of an acid value and an amine value is within the above-mentioned range, coloration does not occur in many paint systems to be toned, and the application range of the pigment dispersion Spread. The acid value and the amine value are preferably 0.5 to 10 mgKOH / g, respectively, from the viewpoint of further expanding the application range of the pigment dispersion. The acid value and amine value of the acrylic resin or modified acrylic resin can be measured according to known methods. If the acid value and amine value of the constituent monomers are known, the acrylic resin can be determined from the amount used and the mixing ratio. Alternatively, the acid value and amine value of the modified acrylic resin can be calculated.

  The acrylic resin or modified acrylic resin of the present invention has a hydroxyl value of 0 to 15 mgKOH / g. When the hydroxyl value exceeds 15 mgKOH / g, the water resistance of the coating film formed by the toned paint may be lowered, and therefore, it is not preferable as the pigment dispersing resin contained in the pigment dispersing resin solution. In the present invention, when the binder resin in the paint mixed with the pigment dispersion resin solution of the present invention does not have a hydroxyl group, the acrylic resin or modified acrylic resin of the present invention has a hydroxyl value. The presence or absence of a hydroxyl group is selected depending on the binder resin in the paint, and the hydroxyl value is set. The hydroxyl value of the acrylic resin or modified acrylic resin can be measured according to a known method. However, if the hydroxyl value of the constituent monomer is known, the hydroxyl value of the acrylic resin or modified acrylic resin can be determined from the amount used or the mixing ratio. It is also possible to calculate the value.

  In the present invention, the acrylic resin or modified acrylic resin having an acid value in the above range is preferably applied to a pigment having a basic surface, and the acrylic resin or modified acrylic resin having an amine value in the above range is particularly preferably a surface. It is desirable to apply to an acidic pigment or a pigment having a nonpolar surface. When the surface is a bipolar pigment, either acrylic resin or modified acrylic resin can be applied. This selection method is based on the acid-base theory of pigment dispersion once the present invention is understood, and can be easily understood experimentally by those skilled in the art.

  The acrylic resin or modified acrylic resin of the present invention has a polymerizable unsaturated monomer represented by the following general formula (I) as a constituent monomer, and the content thereof is the content of the acrylic resin or modified acrylic resin, that is, these components. It is 10 to 35% by mass with respect to the total mass of the constituent monomers constituting the resin. When this content is less than 10% by mass, the pigment dispersibility is lowered, and when it exceeds 35% by mass, the solubility in a weak solvent may be impaired.

However, in the general formula (I), R ₁ is hydrogen or a methyl group, R ₂ is an ethylene or propylene group, R ₃ is an alkyl group or a phenyl group having 1 to 4 carbon atoms, n represents 1 It is an integer of ~ 4.

The alkyl group as R _{3 in the} general formula (I) may be linear or branched, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl. Preferred examples include a group and a t-butyl group. A preferable alkyl group as R ₃ is an alkyl group having 1 or 2 carbon atoms, and a phenyl group is also preferable as R ₃ in addition to the preferable alkyl group.

  Examples of the polymerizable unsaturated monomer represented by the general formula (I) include methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, (n or Iso-) propoxyethyl (meth) acrylate, (n or iso-) propoxypropyl (meth) acrylate, (n, s or t-) butoxyethyl (meth) acrylate, (n, s or t-) butoxypropyl (meth) ) Acrylate, phenoxyethyl (meth) acrylate, phenoxypropyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydipropylene glycol (meth) acrylate, and the like as typical monomers. It can be used in combination and use of two or more.

  The acrylic resin or modified acrylic resin of the present invention has a (meth) acrylic acid ester monomer having a homopolymer SP value of 9.2 or less as a constituent monomer, and the content thereof is the acrylic resin or modified acrylic resin. The resin content, that is, 15% by mass or more and less than 90% by mass with respect to the total mass of the constituent monomers constituting these resins. When the content is less than 15% by mass, the solubility in a weak solvent decreases, and when the content is 90% by mass or more, the pigment dispersibility may decrease.

  Here, the calculation method of the SP value in the present invention will be described below. The SP value is a numerical value specific to the resin composition and serves as a standard for determining compatibility. There are various calculation methods and actual measurement methods. In the present invention, the SP by the vapor pressure method proposed by Hoy is used. Using the molecular attraction constant determined using the value, a value calculated in accordance with the method described in the literature (KL Hoy, J. Paint Technology, 42, [541], 76 (1970)) Shall mean. Specifically, the SP value is represented by δ = (dΣG) / M. Here, d is the density of the polymer, M is the molecular weight of the basic structural unit of the polymer, and ΣG is the sum of the molecular attractive constants G corresponding to the atoms (groups) present in the basic structural unit.

  Examples of the (meth) acrylic acid ester monomer having a homopolymer SP value of 9.2 or less include isopropyl methacrylate (SP value 9.047), isobutyl methacrylate (SP value 9.047), t-butyl acrylate ( SP value 9.080), t-butyl methacrylate (SP value 8.753), n-hexyl methacrylate (SP value 9.183), n-heptyl methacrylate (SP value 9.150), n-octyl methacrylate (SP value) 9.122), 2-ethylhexyl methacrylate (SP value 8.969), nonyl methacrylate (SP value 9.099), decyl methacrylate (SP value 9.078), lauryl methacrylate (SP value 9.045), cetyl (meta) ) Acrylate (SP value 8.997), stearyl methacrylate (Meth) acrylic acid ester monomers such as relate (SP value 9.105) and stearyl methacrylate (SP value 8.980) are listed as typical monomers, and these are used alone or in combination of two or more. can do.

  In order to adjust the acid value and amine value of the acrylic resin or modified acrylic resin to the above ranges, a monomer having an acid group or a monomer having an amino group can be appropriately used as a constituent monomer. In the present invention, the “acid group” includes a carboxy group, a sulfonic acid group, a phosphoric acid group, and the like, and the “amino group” includes a primary to quaternary amino group, and the substituent for substituting the hydrogen atom of the amino group is Including alkyl group, aralkyl group and allyl group.

  Examples of the monomer having an acid group include (meth) acrylic acid, fumaric acid, maleic acid, itaconic acid, vinyl benzoic acid, maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monobutyl ester, and sulfonic acid. Group-containing (meth) acrylates, phosphoric acid group-containing (meth) acrylates and the like can be mentioned as typical monomers, and these can be used alone or in combination of two or more.

  Examples of the monomer having an amino group include N, N-dimethylaminoethyl (meth) acrylate, N, N-methylethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dipropylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-methylpropylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N -Typical examples include dipropylaminopropyl (meth) acrylate, N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide and the like, and these are used alone or in combination of two or more. be able to.

  In order to adjust the hydroxyl value of the acrylic resin or modified acrylic resin within the above range, a monomer having a hydroxyl group can be appropriately used. In the present invention, the “hydroxyl group” is clearly distinguished from the monomer having an acid group in that the “hydroxyl group” does not include a hydroxyl group constituting an acid group such as a carboxy group, a sulfonic acid group and a phosphoric acid group. Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy. Lactone adducts to ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate or 2-hydroxypropyl (meth) acrylate ring-opening adducts of ethylene oxide and propylene oxide, 2-hydroxyethyl ( Dimers and trimers of meth) acrylate or 2-hydroxypropyl (meth) acrylate are listed as typical monomers, and these can be used alone or in combination of two or more.

  The acrylic resin or the modified acrylic resin is composed of a polymerizable unsaturated monomer represented by the general formula (I) as a constituent monomer, that is, a copolymer component, and (meth) acrylic acid having a homopolymer SP value of 9.2 or less. It has an ester-based monomer, and may have at least one monomer of a monomer having an acid group and a monomer having an amino group and a monomer having a hydroxyl group in order to adjust the acid value, amine value and hydroxyl value, Furthermore, you may have the other monomer copolymerizable with these monomers.

  The other monomer may be any monomer other than a polymerizable unsaturated monomer, a (meth) acrylic acid ester monomer, a monomer having an acid group, a monomer having an amino group, and a monomer having a hydroxyl group. (Meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl acrylate, n-butyl (meth) acrylate, isobutyl acrylate, n-pentyl (meth) acrylate, n-hexyl acrylate, cyclohexyl (meth) Acrylate, methylcyclohexyl (meth) acrylate, ethylcyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate (Meth) acrylic acid ester monomers having a SP value of homopolymers such as styrene, nonyl acrylate, decyl acrylate, lauryl acrylate, toluyl (meth) acrylate, glycidyl (meth) acrylate, etc. exceeding 9.2; styrene and α-methyl Aromatic polymerizable unsaturated monomers such as styrene, chlorostyrene, vinyl toluene, vinyl naphthalene, phenyl (meth) acrylate, benzyl (meth) acrylate, vinyl benzoate; vinyl monomers such as vinyl acetate and vinyl propionate; N-alkoxy-substituted amide monomers such as N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; perfluoroethylene, perfluoropropylene, fluoride Fluorine-containing vinyl monomers such as vinylidene; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; dialkyl esters of maleic acid and fumaric acid; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene Typical examples include monomers such as vinyl chloride, vinylidene chloride, allyl chloride, etc., and these can be used alone or in combination of two or more.

  The pigment dispersing resin in the present invention may be the acrylic resin which is a copolymer of the above-described constituent monomers. In addition to the constituent monomers, for example, an alkyd resin or a polyester resin is used as a copolymerizable component. The modified acrylic resin may be used. Moreover, it can also be set as the modified acrylic resin which used together the alkyd resin and the polyester resin as a copolymerizable component. Typical examples of the alkyd resin and polyester resin include alkyd resins containing maleic acid, fumaric acid or unsaturated fatty acids, and polyester resins containing maleic acid, fumaric acid or unsaturated fatty acids. It can be used alone or in combination of two or more.

  The pigment dispersing resin of the present invention can be produced by known polymerization methods such as solution polymerization method, bulk polymerization method, emulsion polymerization method and the like as described above. In particular, the pigment-dispersing resin of the present invention is preferably simple and preferably produced by a solution polymerization method. When the pigment dispersion resin of the present invention is produced by a solution polymerization method, a mixture of constituent monomers is copolymerized in the presence of a solvent and a polymerization initiator. The copolymerization may be performed at a temperature at which the constituent monomers can be polymerized, and usually 80 to 140 ° C. is appropriate. At this time, a resin having the above characteristics can be obtained by copolymerizing the constituent monomers according to the polymerization ratio of the constituent monomers calculated so as to obtain the above characteristics by a conventional method.

  Any solvent can be used without particular limitation as long as it is a solvent that can dissolve the pigment-dispersing resin of the present invention. Examples of such a solvent include a weak solvent described later and an organic solvent other than the weak solvent. Examples of organic solvents other than weak solvents include hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, methoxypropyl acetate, ethylene glycol monomethyl ether acetate, and butyl carbitol acetate. Solvent, ether solvents such as dioxane, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and diethylene glycol, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone, alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol And solvent. These solvents can be used alone or in combination.

  The pigment dispersion resin of the present invention is obtained by copolymerizing the above-described constituent monomers in the presence of a polymerization initiator or the like. As a polymerization initiator used at the time of copolymerization, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4- Azo polymerization initiators such as dimethylvaleronitrile; benzoyl peroxide, tert-butylperoxyisobutyrate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxy-3,5,5-trimethyl Examples thereof include organic peroxide polymerization initiators such as hexanoate, tert-butylperoxyisopropyl monocarbonate, and 2,2-bis (4,4-ditert-butylperoxycyclohexyl) propane. Moreover, chain transfer agents, such as 2-mercaptoethanol and n-octyl mercaptan, can also be used as needed.

  The weak solvent contained in the pigment dispersion resin solution of the present invention is a weak solvent used in the synthesis of the pigment dispersion resin of the present invention or a weak solvent added separately to the pigment dispersion resin of the present invention. Specifically, it means a solvent having a weak dissolving power, specifically, a solvent having an aniline point defined by JIS K 2266 of 12 to 55 ° C. This weak solvent is an aliphatic hydrocarbon solvent that may contain a high-boiling aromatic hydrocarbon solvent corresponding to the Class 3 organic solvent of the Industrial Safety and Health Act, and is represented by terpenes, mineral spirits, etc. Such as those with high flash point, high boiling point, and low toxicity.

  Typical examples of such a weak solvent include mineral spirit A (aniline point = 43 ° C.), white spirit, mineral turpentine, isoparaffin, solvent kerosene, aromatic naphtha, VM & P naphtha, solvent naphtha and the like. Examples of these commercially available products include Solvesso 100 (aniline point = 14 ° C.), Solvesso 150 (aniline point = 15 ° C.), Solvesso 200 (aniline point = 13 ° C.), and naphtha no. 6 (aniline point = 43 ° C); SWAZOL 1000 (aniline point = 12.5 ° C) manufactured by Maruzen Petrochemical Co., Ltd., SWAZOL 1500 (aniline point = 17 ° C), SWAZOL 1800 (aniline point = 14.5 ° C); Ipsol 100 (aniline point = 12.4 ° C.), Ipsol 100 (aniline point = 14.8 ° C.) manufactured by Idemitsu Kosan Co., Ltd .; HAWS (aniline point = 15 ° C.), LAWS (aniline point) manufactured by Shell Chemicals Japan Ltd. = 12.4 ° C.); A solvent (aniline point = 44.5 ° C.) manufactured by JX Nippon Oil & Energy Corporation, and the like. Examples of other single component solvents include aliphatic hydrocarbons such as n-butane, n-hexane, n-heptane, n-octane, isononane, n-decane, n-dodecane, cyclopentane, cyclohexane and cyclobutane. It is done. These can be used alone or in combination of two or more.

  In this invention, the weak solvent should just have the aniline point as a whole solvent in the range of 12-55 degreeC, for example, the above-mentioned weak solvent with an aniline point of 12-55 degreeC, or a weak mixture with a weak component. A solvent may be sufficient, and the mixed solvent containing these weak solvents and strong solvents, for example, organic solvents other than a weak solvent may be sufficient. The multi-mixed solvent only needs to have an aniline point of 12 to 55 ° C. as a whole. For example, the content of the weak solvent is preferably larger than the content of the organic solvent.

  The concentration of the pigment dispersion resin in the pigment dispersion resin solution of the present invention in which the pigment dispersion resin of the present invention is dissolved in a weak solvent is 20 to 90%, preferably 30 to 80%. If the concentration of the pigment dispersion resin is lower than 20%, a high concentration pigment dispersion cannot be obtained. If the concentration is higher than 90%, the viscosity of the pigment dispersion resin solution becomes too high and the handling property is lowered. It is not preferable.

  Next, the pigment dispersion of the present invention will be described. This pigment dispersion contains the resin solution for pigment dispersion of the present invention, that is, the acrylic resin or modified acrylic resin of the present invention, a weak solvent and a pigment.

  The weak solvent contained in the pigment dispersion of the present invention may be a weak solvent contained in the pigment dispersion resin solution of the present invention, and is newly added to the pigment dispersion resin solution and pigment of the present invention. A weak solvent may be used. The newly added weak solvent may be the same or a different weak solvent as the weak solvent contained in the pigment dispersion resin solution of the present invention. In addition to the pigment dispersion resin solution and the pigment, a solvent other than the weak solvent can be added to the pigment dispersion of the present invention. In this case, the color tone stability and the color tone aging stability are maintained well. Therefore, it is preferable that 50% or more of the weak solvent is contained with respect to the solvent (volatile component) contained in the pigment dispersion. In addition, solvents other than a weak solvent are not specifically limited, For example, the said organic solvent etc. are mentioned, 1 type (s) or 2 or more types can be mixed and used.

  The blending amount of the pigment dispersion resin solution of the present invention in the pigment dispersion of the present invention is preferably 2 to 80% by mass, particularly preferably converted to the pigment dispersion resin amount of the present invention based on the mass of the pigment dispersion. Is from 5 to 70% by weight. The blending amount of the pigment-dispersing resin dissolved in the pigment-dispersing resin solution of the present invention varies greatly depending on each pigment type, and within the above range, a comparison is made with a pigment having a large oil absorption such as carbon black. In the case of a pigment having a small oil absorption such as Bengala, it is preferable to blend in a relatively small amount. A person skilled in the art can easily understand this concept regarding the amount of the mixture experimentally.

  The blending amount of the weak solvent (including solvents other than the weak solvent) in the pigment dispersion of the present invention depends on the blending amount of the resin solution for pigment dispersion of the present invention, but is preferably 5 to 90% by mass, for example. Especially preferably, it is 10-70 mass%.

  Examples of the pigment include inorganic oxides such as titanium oxide, heavy metal compound pigments such as zinc oxide, graphite, black iron oxide, red iron oxide, yellow iron oxide, ocher, yellow lead, titanium yellow, chromium vermilion, and various fired pigments. Colored pigments; body pigments such as precipitated barium sulfate, calcium carbonate, silica, kaolin and talc; black pigments such as carbon black; azo, quinacridone, pyrazolone, benzimidazolone, anthraquinone, perylene, Colored organic pigments such as diketopyrrolopyrrole, isoindolinone, isoindoline, quinophthalone, phthalocyanine, and dioxazine; aluminum powder, copper powder, nickel powder, stainless steel powder, chromium powder, mica-like iron oxide, Bright pigments such as titanium oxide-coated mica powder, iron oxide-coated mica powder, and bright graphite It is cited as typical. These pigments have unique surface states such as acidity, basicity, bipolarity, and nonpolarity depending on the production method and the type of surface treatment. The blending amount of the pigment is, for example, preferably 2 to 90% by mass, particularly preferably 5 to 80% by mass, based on the mass of the pigment dispersion. The pigment concentration in the pigment dispersion is within the above-mentioned range, and about 3 to 8 times that of ordinary paint is appropriate.

  A commercially available pigment dispersant can be used in combination with the pigment dispersion of the present invention, if necessary. Examples of such commercially available pigment dispersants include, for example, Disparon KS-260, KS-273N, KS-281, 2200, KS-860, KS-873N manufactured by Enomoto Kasei Co., Ltd .; Kyoeisha Chemical Co., Ltd. FLOREN AF-205, AF-405, AF-1000, AF-1005, G-700, DOPA-33, DOPA-17; EFKA-4010, EFKA-4046, EFKA-4047, EFKA- manufactured by EFKA Chemicals 4050, EFKA-4055, EFKA-4060, EFKA-4401, EFKA-4520, EFKA-4530, EFKA-5063, EFKA-5064, EFKA-5065, EFKA-5066, EFKA-5070, EFKA-6220 (Bicchemy Japan) Co., Ltd. Anti-Te ra-203, Anti-Terra-204, Anti-Terra-U, Bykumen, Disperbyk-101, Disperbyk-108, Disperbyk-111, Disperbyk-130, Disperbyk-140, Disperbyk-160, Disperk63, -1disder63, -162 Disperbyk-164, Disperbyk-166, Disperbyk-171, Disperbyk-174, Disperbyk-182, Disperbyk-2000, Disperbyk-2001; Solsperse 5000, Solsperse 2400, Solsper 2400, Solsper 24000, Solsper 24000, Solsper 2se And the like.

  The amount of the commercially available pigment dispersant that can be arbitrarily blended is, for example, preferably 0 to 20% by mass, particularly preferably 0.5 to 15% by mass, based on the mass of the pigment dispersion of the present invention. is there. However, when the blending amount exceeds 20% by mass, the coating film performance may be deteriorated.

  The pigment dispersion of the present invention may be blended with additives such as an anti-settling agent as necessary. Examples of the anti-settling agent that can be blended as necessary include organic bentonite, silica, and the like, and various organic anti-settling agents marketed by the additive manufacturers.

  Preparation of the pigment dispersion which is the mill base for common toning according to the present invention is carried out, for example, in a dispersing apparatus such as a ball mill, roll mill, sand mill, nanomill, homomixer, etc., the resin solution for pigment dispersion of the present invention, that is, the pigment dispersion of the present invention. It is carried out by mixing and dispersing a resin and a weak solvent, a pigment, a weak solvent, if necessary, a commercially available pigment dispersant added if necessary, and an additive such as an anti-settling agent. The pigment dispersion prepared by these dispersing devices has a suitable range of pigment particles having a maximum particle size of 1 to 20 μm, preferably 2 to 10 μm.

  The pigment dispersion of the present invention thus prepared can be applied for toning of various paints. That is, the toning paint or primary color paint of the present invention contains the base dispersion containing the pigment dispersion of the present invention and the binder resin, that is, the primary color paint, and various additives as necessary. Applicable paint types are acrylic resin paint, phthalic acid resin paint, synthetic resin paint, vinyl resin paint, short to medium oil alkyd resin paint, polyester resin paint, epoxy resin paint, fluorine Typical examples include resin-based paints, silicone resin-based paints, and cellulose resin-based paints. In the present invention, by using the pigment dispersion of each color for a wide variety of paints, it is possible to establish a paint color-matching system with significantly improved production efficiency. It is possible to reduce environmental impact, reduce delivery time to customers, reduce the amount of paint and seeds in stock, and bring many benefits. In particular, even when the pigment dispersion of the present invention is used in a paint containing a weak solvent, it does not adversely affect the properties of the paint / coating film inherent to the paint, and color separation properties, particularly color tone stability and color tone aging stability. Can be greatly improved. In addition, by using the pigment dispersion of the present invention for paints containing weak solvents, production efficiency is greatly improved, and in addition to toning in tanks, toning in cans is possible, reducing cleaning solvents Therefore, it is possible to establish a toning system that shortens delivery time to customers. Furthermore, the pigment dispersion of the present invention can be used not only for paints containing strong solvents but also for paints containing weak solvents. Can be established.

  Next, a method for toning a paint using the pigment dispersion of the present invention will be described. As the toning method, for example, a chinching method, a load method, or the like is adopted as a representative method.

  Hereinafter, a method for preparing the toning paint by the chinching method will be described. The tinting system (Tinting System) uses a CCM (Computer Color Matching) and an auto dispenser to input a target color tone data, and then to a primary color paint such as white (also referred to as a base paint) to be toned. This is a method for producing a toning paint by measuring, mixing and stirring the pigment dispersion of the present invention. It has been confirmed that the toning accuracy to the target color tone can be very high due to the recent improvement in CCM accuracy and the excellent pigment dispersibility of the pigment dispersion of the present invention. In the tinching method using the pigment dispersion of the present invention, each color dispersion for common toning is prepared and mixed into various white primary color paints from an auto dispenser, for example, to keep the composition balance optimal. Mixing the composition adjusting liquid (composition consisting of binder resin, organic solvent, additive, extender pigment, etc.), stirring and inspecting inside the can, it is also called the toning paint (also referred to as the toning paint composition) of the present invention. .) Can be obtained. This method is particularly suitable for toning of light and medium colors. In the tinching method using the pigment dispersion of the present invention, it is also possible to obtain a toning paint without blending the composition adjusting liquid. In general, when the amount of the pigment dispersion is increased, the composition balance in the paint is usually lost. However, when the pigment dispersion of the present invention is used, the paint properties, It has been confirmed that it can be maintained without adversely affecting the coating performance. This method is particularly suitable for light toning. This chinching method is very suitable for dealing with small orders, and has advantages such as shortening delivery time to customers and reducing cleaning work by toning in a can.

  Hereinafter, a method for preparing a toning paint by a load method will be described. The load system is a pigment dispersion for toning, a binder resin for paint, and, if necessary, a weak solvent, extender pigment, polymer fine particles, a curing catalyst, an ultraviolet absorber, an ultraviolet stabilizer, This is a method for obtaining a toned paint by mixing various additives such as a coating surface adjusting agent, an antioxidant, a fluidity adjusting agent, and a silane coupling agent. In the load method, it is possible to mix the above-mentioned individual raw materials in order, but it is efficient by pre-dissolving or kneading the individual raw materials and using the body base described in the previous chinching method. It is possible to prepare primary colors well. The load method does not require a conventional kneading step and can prepare each primary color paint only by dissolution, and is therefore suitable for toning of dark colors using each primary color paint. Typical examples of the binder resin include acrylic resin, phthalic acid resin, synthetic resin, polyester resin, alkyd resin, epoxy resin, fluororesin, silicone resin, amino resin, and polyisocyanate compound. . These binder resins can be used alone or in combination of two or more. The polyisocyanate compound includes both a blocked polyisocyanate compound in which an isocyanate group is blocked and a non-blocked polyisocyanate compound.

  The blending amount of the binder resin is, for example, preferably 10 to 95% by mass, particularly preferably 20 to 90% by mass in the toning paint. As the weak solvent used as necessary, various organic solvents containing 50% or more of the same weak solvent as exemplified in the pigment dispersion can be used. The weak solvent is, for example, preferably 0 to 80% by mass, particularly preferably 2 to 70% by mass in the colored paint. Examples of the extender pigment include precipitated barium sulfate, calcium carbonate, silica, kaolin, talc and the like, and in the colored paint, for example, preferably 0 to 50% by mass, particularly preferably 5 to 40% by mass. The polymer fine particles are polymers that do not dissolve in the colored paint and are dispersed as fine particles, and those having an average particle diameter in the range of 0.01 to 1 μm are usually preferable. The fine polymer particles may or may not be crosslinked inside the particles, but those crosslinked internally are desirable. The fine particles are known per se, and can be appropriately selected from these. The blending amount of the polymer fine particles is, for example, preferably 0 to 20% by mass, particularly preferably 1 to 10% by mass in the toning paint.

  Examples of the curing catalyst include dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, copper naphthenate, and triethylenediamine when the curing agent is a polyisocyanate compound, and the curing agent is melamine. In the case of an amino resin such as a resin, sulfonic acid compounds such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid and dinonylnaphthalenesulfonic acid, and amine neutralized products of these sulfonic acid compounds can be used. The blending amount of the curing catalyst is, for example, preferably 0 to 2% by mass, particularly preferably 0.02 to 1% by mass in the colored paint. Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, cyanoacrylate-based, salicylate-based, and oxalic acid anilide-based ultraviolet absorbers. The blending amount of the ultraviolet absorber is, for example, preferably 0 to 10% by mass, particularly preferably 0.1 to 5% by mass in the colored paint. Examples of the ultraviolet stabilizer include hindered amine compounds. The amount of the ultraviolet stabilizer in the colored paint is, for example, preferably 0 to 20% by mass, particularly preferably 0.2 to 10% by mass.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited to them. In Examples and Comparative Examples, “parts” and “%” mean “parts by mass” and “% by mass”, respectively, unless otherwise specified.

  First, a method for calculating the characteristic values of the pigment dispersion resin of the present invention and the pigment dispersion resin of the comparative example will be described below. The number average molecular weight (Mn) was measured by GPC equipped with RI (manufactured by Tosoh Corporation; HLC-8220 GPC) using a TSKgel column (manufactured by Tosoh Corporation). As GPC conditions, tetrahydrofuran was used as a developing solvent, and measurement was performed at a flow rate of 0.35 ml / min and a temperature of 40 ° C.

The definitions of the acid value, amine value, and hydroxyl value described in Table 1 below are shown below.
Acid value: mg of potassium hydroxide required to neutralize 1 g of resin solids Amine value: mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize 1 g of resin solids Hydroxyl value: resin solids The number of mg of potassium hydroxide required to completely acetylate the free hydroxyl group in 1 g with acetic anhydride and neutralize it

(Example I and Comparative Example I)
Examples of Synthesis of Pigment Dispersing Resin of the Invention and Synthesis Examples of Pigment Dispersing Resin of Comparative Example, Preparation Examples of Resin Dispersing Solution of Pigment Dispersion of the Present Invention and Preparation Examples of Resin Dispersing Resin Solution of Comparative Example Show.
<Synthesis Example 1>
Acrylic resin reaction tank equipped with a stirrer, thermometer, reflux condenser, etc. was charged with 25 parts of mineral spirit A (manufactured by JX Nippon Mining & Energy Corporation), heated and stirred, and after reaching 100 ° C., the following monomers Etc. was added dropwise over 3 hours. After completion of the dropwise addition, an additional catalyst solution that is a mixture of 0.5 part of 2,2′-azobis-2-methylbutyronitrile and 2 parts of Solvesso 100 (manufactured by Esso Petroleum Co., Ltd.) is maintained while maintaining the temperature at 100 ° C. It took time and dropped. The mixture was further stirred at 100 ° C. for 1 hour and then cooled. This was diluted by adding 17 parts of mineral spirit A to obtain a resin solution for pigment dispersion of the present invention having a solid content concentration of 55.5% (referred to as resin solution 1 in Table 1). The obtained acrylic resin had a number average molecular weight (Mn) of 8,500 and an acid value of 4.2 mgKOH / g.
<Mixture of monomers, etc.> 3 parts of 2-ethylhexyl acrylate and 8.3 parts of methyl methacrylate as other monomers, 10 parts of phenoxyethyl methacrylate as the polymerizable unsaturated monomer represented by the general formula (I), SP value of homopolymer Is 9 parts isobutyl methacrylate, 14.9 parts t-butyl methacrylate and 9 parts lauryl methacrylate as a (meth) acrylic acid ester monomer with a 9.2 or less, 0.3 parts acrylic acid as a monomer having an acid group, polymerization started 1,2'-azobis-2-methylbutyronitrile as an agent

<Synthesis Examples 2-16>
Using the same method as in Synthesis Example 1, each monomer was reacted with the formulation shown in Table 1. Synthesis examples 14 and 15 could not be synthesized as resin solutions. Resin solutions 2 to 6 of the present invention and resin solutions 7 to 13 and 16 of comparative examples were obtained as intended by synthesis examples 2 to 13 and 16.

(Example II and Comparative Example II)
Production examples of the pigment dispersion of the present invention are shown below.
<Production Example 1>
25.5 parts of the resin solution for pigment dispersion of the present invention obtained in Synthesis Example 1 (resin solution 1), 6.7 parts of Disperbyk-140 (manufactured by Big Chemie Japan Co., Ltd.) as a pigment dispersant, and Raven420 (as a black pigment) 35 parts of Colombia Carbon Japan Co., Ltd. and 32.8 parts of Mineral Spirit A (JX Nippon Mining & Energy Corporation) are dispersed for 2 hours in a paint shaker (Asada Tekko Co., Ltd.) (capacity 225 cc) A wide-mouth glass bottle, 1.3 mm diameter titania beads), and a black pigment dispersion (referred to as black dispersion 1 in Table 1).

<Production Examples 2-14>
Using the same method as in Production Example 1, dispersion was carried out with the formulation shown in Table 2 to obtain the intended black pigment dispersions (black dispersions 2 to 14). The dispersion conditions were the same as in Production Example 1.

<Production Example 15>
15.5 parts of the resin solution for pigment dispersion of the present invention obtained in Synthesis Example 1 (resin solution 1), 0.1 part of RAYTONE 34 (manufactured by Southern Clay Products, Inc.) as a pigment dispersant, and TAROX synthetic oxidation as a yellow pigment 56 parts of iron LL XLO (manufactured by Titanium Industry Co., Ltd.), 3.5 parts of light calcium carbonate MC-K (manufactured by Maruo Calcium Co., Ltd.) as an extender pigment, mineral spirit A (manufactured by JX Nippon Oil & Energy Corporation) 24.9 Parts were dispersed for 2 hours in a paint shaker (manufactured by Asada Tekko Co., Ltd.) (using a wide-mouth glass bottle with a capacity of 225 cc and a diameter of 1.3 mmφ titania beads), and a yellow pigment dispersion (yellow dispersion in Table 1) 1).

<Production Examples 16 to 28>
Using the same method as in Production Example 15, the dispersion shown in Table 3 was used to obtain the intended yellow pigment dispersion (yellow dispersions 2 to 14). The dispersion conditions were the same as in Production Example 15.

<Production Example 29>
28.8 parts of the resin solution for pigment dispersion of the present invention (resin solution 1) obtained in Synthesis Example 1, 0.5 part of Disperbyk-160 (manufactured by Big Chemie Japan Co., Ltd.) as a pigment dispersant, and CYANINE BLUE as a blue pigment Disperse 23 parts of 2050 (manufactured by Sanyo Pigment Co., Ltd.) and 47.7 parts of mineral spirit A (manufactured by JX Nippon Mining & Energy Corporation) for 2 hours with a paint shaker (manufactured by Asada Iron Works Co., Ltd.) (capacity) 225 cc wide-mouth glass bottle, 1.3 mm diameter titania beads were used), and a blue pigment dispersion (referred to as blue dispersion 1 in Table 1) was obtained.

<Production Examples 30 to 42>
Using the same method as in Production Example 29, the dispersion shown in Table 4 was used to obtain the desired blue pigment dispersion (blue dispersions 2 to 14). The dispersion conditions were the same as in Production Example 29.

(Example III and Comparative Example III)
Next, a preparation method of a toning coating composition by a tinching method using each of the produced pigment dispersions and a method for producing a coated plate will be described below.
<Toning paint preparation method>
Each of the following white base paints 100 g was placed in a 200 cc polycup, and the black dispersion 1 and the yellow dispersion 1 produced in Example II and Comparative Example II using the resin solution 1 for each of the three types of white base paints. A total of 9 g of 3 g of blue dispersion 1 was mixed and allowed to stand for 10 minutes. Then, it stirred for 10 minutes at 2000 rpm with the disper. This was divided into two portions of 50 g each, and one was used as a coating material for preparing an initial coated plate, and the other was stored at 50 ° C. as a coating material for preparing a coated plate over time. Similarly, the same resin solution was used for black dispersions 2 to 14, yellow dispersions 2 to 14, and blue dispersions 2 to 14 produced in Example II and Comparative Example II using resin solutions 2 to 13 and 16. The three types of dispersions produced in this way were mixed in each white base paint to prepare a paint for preparing an initial coated plate and a paint for preparing a coated plate over time.
The white base paint used for toning is as follows. Phthalic acid resin enamel (Himel unleaded white; manufactured by Dainippon Paint Co., Ltd.), Synthetic resin blended paint (Taiko Paint White; manufactured by Dainippon Paint Co., Ltd.) and acrylic resin-based non-aqueous dispersion paint (Bildec White; Company-made)

<Coating plate production method 1>
In the coating material for preparing the initial coating plate, a thinner for viscosity adjustment is added with Iwata Cup # 2 so that the coating viscosity is 16 to 20 seconds, and after stirring, a dry film thickness is applied to a tin plate (SPTE: 0.3 × 50 × 150 mm). Was applied by spraying so as to be 30 μm. One minute after spray coating, the upper part of the coated plate was rubbed with fingers 20 times. This was dried at room temperature for 1 week to obtain the intended coated plate. Moreover, the coating material for time-dependent coating board preparation performed the coating board preparation by the method similar to the above after 30 days at 50 degreeC. The coated plate produced by the above method was subjected to a colorful evaluation test.

<Coating plate production method 2>
In the coating material for preparing the initial coating plate, a viscosity adjusting thinner is put in Iwata Cup # 2 so that the coating viscosity is 16 to 20 seconds, and after stirring, it is applied to a polished mild steel plate (SPCC-SB: 0.8 × 70 × 150 mm). Spray coating was performed so that the dry film thickness was 30 μm. This was dried at room temperature for 1 week to obtain the intended coated plate. The back surface of the obtained test plate was sealed with a vinyl chloride paint and subjected to a water resistance evaluation test.

  Table 5 shows the evaluation results regarding the water resistance, color tone stability and color tone stability over time of the coated plate prepared according to the above-described method. The color stability immediately after toning was evaluated for the color tone stability, and the color tone after storage of the toned paint at 50 ° C. for 30 days was evaluated for the color tone aging stability.

<Water resistance evaluation>
Each coated plate produced by the coated plate production method 2 was immersed in tap water for 7 days at 23 ° C., and then the appearance was visually evaluated and evaluated according to the following criteria.
○: No abnormality, ×: Abnormality such as swelling was observed.

<Colorfulness evaluation>
After measuring the color tone of the spray part and the rubbing part using a spectrocolorimeter (Macbeth COLOR EY MS-2020PL; manufactured by Macbeth Co., Ltd.) on each of the paint sheets produced by the paint plate production method 1, the color difference between the spray part and the rubbing part was measured. And evaluated according to the following criteria.
○: Color difference of less than 1, Δ: Color difference of 1 or more and less than 2, ×: Color difference of 2 or more

  Using the pigment dispersions (black dispersions 1 to 6, yellow dispersions 1 to 6, and blue dispersions 1 to 6) of the present invention shown in Tables 2 to 4 toned, they were toned. As can be seen from Table 5, the paints (initial coating plate preparation paints and temporal coating plate preparation coatings) both have excellent color tone stability and color tone aging stability. It turned out not to decrease. It should be noted that in the pigment dispersion of the present invention, the pigment is dispersed at a high concentration, specifically, 35% by mass of black pigment, 56% by mass of yellow pigment, and 23% by mass of blue pigment. Nevertheless, it is to be able to prepare a weak solvent-based toning paint or primary color paint having excellent pigment dispersibility and excellent color tone stability and color tone stability over time. Of course, this effect is sufficiently exhibited by the pigment dispersion of the present invention in which the pigment is dispersed at a low concentration. In Example III, the black dispersion 1, the yellow dispersion 1 and the blue dispersion 1 were mixed in each white base paint to evaluate the color stability and the color stability with time. It is clear that similar results can be obtained with a toning paint prepared by mixing each dispersion into each white base paint.

  By using the pigment-dispersing resin of the present invention, a pigment dispersion for common toning in which pigment dispersibility and coloring power are stable over time can be obtained. In addition, the pigment dispersion of the present invention does not adversely affect the properties of paints and coating films inherent to the paints in paints containing a wide variety of weak solvents, and the coloration properties, particularly the color tone stability and the color tone aging stability. Is very useful and industrially useful. In addition, by using this for paints containing a wide variety of weak solvents, production efficiency has been greatly improved, and in addition to toning in tanks, toning in cans is also possible, reducing cleaning solvents, customers A toning system can be established that achieves shorter delivery times.

Claims (3)

A resin solution for pigment dispersion containing an acrylic resin or a modified acrylic resin and a weak solvent,
The acrylic resin or modified acrylic resin has a number average molecular weight of 2,000 to 14,000, an acid value and an amine value of 0.1 to 15 mgKOH / g, and a hydroxyl value of 0 to 15 mgKOH / g. Furthermore, 10 to 35% by mass of the polymerizable unsaturated monomer represented by the following general formula (I) with respect to the total mass of the constituent monomers , and the SP value of the homopolymer is 9.2 or less (meta) pigment dispersing resin solution characterized in that it is manufactured by copolymerizing constituent monomer containing less than 1 5% by weight or more and 90 wt% acrylic acid ester monomer.

However, in the general formula (I), R ₁ is hydrogen or a methyl group, R ₂ is an ethylene or propylene group, R ₃ is an alkyl group or a phenyl group having 1 to 4 carbon atoms, n represents 1 It is an integer of ~ 4.   A pigment dispersion comprising the pigment-dispersing resin solution according to claim 1 and a pigment.   A toning paint or primary color paint comprising the pigment dispersion according to claim 2.