Polymer, surface conditioner for aqueous coating material, and curable resin composition

Abstract

To provide a polymer capable of providing a surface conditioner for an aqueous coating material, the surface conditioner using water as an environmentally friendly solvent, having excellent leveling performance, and capable of being used in a colorless transparent resin even after curing since whitening marks are unlikely to occur even after curing.SOLUTION: Provided is a polymer comprising, as constituent monomers, a monomer (A) represented by formula (1) below and a monomer (B) represented by formula (2) below. The polymer, based on 100 wt.% of the total monomers constituting the polymer, comprises from 10 to 80 wt.% of the monomer (A) and from 20 to 90 wt.% of the monomer (B) as constituent units, with a weight average molecular weight of from 3,000 to 3,000,000.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer, a surface conditioner for water-based paints, and a curable resin composition. [Background technology]

[0002] Copolymers containing (meth)acrylic monomers as constituent monomers are used in fields such as molding materials, paints, and adhesives. They are known as resins characterized by excellent weather resistance, transparency, and processability. Representative examples of these monomers include fluorine-based monomers and siloxy-group-containing (meth)acrylate monomers. One example of their use is as a surface conditioner. Surface conditioners can improve surface defects such as cratering and dents on paint film surfaces, as well as hydrophilize the paint film surface to improve wettability and wash away contaminants. This is because the copolymers in surface conditioners exhibit high orientation, reducing dynamic surface tension and resulting in a smooth paint film.

[0003] Surface conditioners are blended to form coating films that have a high-quality, aesthetically pleasing finished appearance, i.e., a smooth appearance without cissing, craters, fish eyes, cloudiness, etc., on various substrates such as automotive materials, luxury furniture, and home appliances.

[0004] In recent years, for the purposes of resource conservation and environmental conservation, water-based paints have been increasingly used in place of solvent-based paints for the above-mentioned coating processes. Water-based paints have had the following problems due to the physical properties of the solvent, water. For example, when water-based paints are applied to substrates, the high surface tension of water results in insufficient wettability between the water-based paint and the substrate, resulting in the problem of cissing. Another problem is that when the water-based paint applied to the substrate dries and hardens, depressions form, resulting in an uneven surface.

[0005] Furthermore, copolymers containing (meth)acrylic monomers as constituent monomers have been used as surface conditioners. Patent Document 1 proposes a surface conditioner for aqueous paints, which is composed of a (meth)acrylic resin containing, as constituent monomers, a dibasic acid ester having a polymerizable unsaturated double bond and a polymerizable unsaturated monomer containing an ether group of a specific structure. Patent Document 2 also proposes a (meth)acrylic resin composed of an ether group-containing alkyl (meth)acrylate monomer of a specific structure and an alkyl (meth)acrylate monomer of a specific structure. However, since the above (meth)acrylic resin uses an organic solvent as the solvent, there is a need for a surface conditioner that uses water, which has a lower environmental impact, as the solvent and has good leveling performance.

[0006] On the other hand, the use of surfactants and silica to improve the leveling properties of water-based paints is commonly known. Patent Document 3 proposes a surface conditioner composed of a water-soluble resin having anionic and / or cationic groups in a water-containing solvent and a water-soluble non-polymeric compound that is an ionic compound. Patent Document 4 also proposes a paint composition containing an amphiphilic polymer having at least one functional group selected from amide, amino, and hydroxyl groups as a hydrophilic portion and a hydrophobic portion, colloidal silica dispersed in an aqueous medium, and an aqueous resin dispersion obtained by polymerizing an α,β-ethylenically unsaturated monomer. However, surfactants and silica have poorer leveling performance than surface conditioners containing (meth)acrylic resin as a constituent monomer. Furthermore, aggregation of the surfactant and silica during drying of the paint film causes whitening marks, making them particularly unusable for colorless, transparent resins such as highly transparent polycarbonate resins and polyacrylic resins. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2020 / 009228 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-105786 [Patent Document 3] Japanese Patent Application Publication No. 2018-95756 [Patent Document 4] Japanese Patent Application Laid-Open No. 2013-144808 Summary of the Invention [Problem to be solved by the invention]

[0008] That is, an object of the present invention is to provide a polymer that can be used to provide a surface conditioner for aqueous paints having the following properties (i) to (iii): (i) it uses water, which has a low environmental impact, as a solvent, (ii) it has good leveling performance, and (iii) it is less likely to leave white marks after curing, making it usable for colorless, transparent resins. Another object is to provide a surface conditioner for aqueous paints that has such properties, and further to provide a curable resin composition that is less likely to leave white marks after curing. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, they have found that the above-mentioned object can be achieved by a polymer having a predetermined weight-average molecular weight and containing, as constituent monomers, predetermined amounts of two types of monomers with predetermined structures as constituent units, and have thus completed the present invention. The gist of the present invention is as follows.

[0010] [1] A polymer containing, as constituent monomers, a monomer (A) represented by the following general formula (1) and a monomer (B) represented by the following general formula (2), wherein the polymer contains, as constituent units, 10 to 80 mass % of the monomer (A) and 20 to 90 mass % of the monomer (B), relative to 100 mass % of the total monomers constituting the polymer, and has a weight average molecular weight of 3,000 to 3,000,000.

[0011] [ka]

[0012] (In formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2represents an alkylene group having 1 to 4 carbon atoms, and R 3 CO- has 2 to 30 carbon atoms, and R 3 indicates an acyl group of an aliphatic hydrocarbon group.)

[0013] [ka]

[0014] (In formula (2), R 4 represents a hydrogen atom or a methyl group, and R 5 represents an alkylene group having 1 to 6 carbon atoms, and R 6 is the formula (2a), the formula (2b) or the formula (2c)

[0015] [ka]

[0016] (In formula (2a), formula (2b), or formula (2c), * indicates the bond position, R 7 ~R 11 each independently represents a hydrogen atom, a methyl group, or an ethyl group; X - represents a halide ion, Y represents a carbon atom or a sulfur atom, n represents 1 or 2, and M + indicates an alkali metal ion.) represents a monovalent group represented by the formula:

[0017] [2] A surface conditioner for water-based paints, comprising the polymer described in [1] above.

[0018] A curable resin composition containing 0.1 to 50 parts by mass of the polymer described in [1] above per 100 parts by mass of a curable resin. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a polymer that can be used to provide a surface conditioner for water-based paints that has the following properties (i) to (iii): (i) it is a surface conditioner for water-based paints that uses water as a solvent, which has a low environmental impact, (ii) it has good leveling performance, and (iii) it is unlikely to leave white marks after curing, making it suitable for use with colorless, transparent resins. Furthermore, according to the present invention, by using a surface conditioner for aqueous paints containing the polymer, it is possible to improve the leveling properties of the paint film, and by not containing surfactants or silica that can cause whitening, it is possible to suppress whitening due to aggregation and form a transparent paint film, and since the curable resin composition containing the surface conditioner for aqueous paints has the property of being less likely to leave white marks after curing, the surface conditioner for aqueous paints and the curable resin composition according to the present invention can be suitably used in paints, molding materials, adhesives, etc. for automobiles, furniture, home appliances, etc. DETAILED DESCRIPTION OF THE INVENTION

[0020] In this specification, "(meth)acrylic" is a general term that includes acrylic and methacrylic, and "(meth)acrylate" is a general term that includes acrylate and methacrylate. Terms such as "(meth)acryloyl group" have the same meaning as "(meth)acrylate."

[0021] Hereinafter, an embodiment of the present invention will be described.

[0022] <Polymer> The polymer according to an embodiment of the present invention is a polymer containing, as constituent monomers, a monomer (A) represented by the following general formula (1) and a monomer (B) represented by the following general formula (2), and the polymer contains, as constituent units, 10 to 80 mass% of the monomer (A) and 20 to 90 mass% of the monomer (B), relative to 100 mass% in total of the monomers constituting the polymer, and has a weight average molecular weight of 3,000 to 3,000,000.

[0023] [ka]

[0024] (In formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents an alkylene group having 1 to 4 carbon atoms, and R 3 CO- has 2 to 30 carbon atoms, and R 3 indicates an acyl group of an aliphatic hydrocarbon group.)

[0025] [ka]

[0026] (In formula (2), R 4 represents a hydrogen atom or a methyl group, and R 5 represents an alkylene group having 1 to 6 carbon atoms, and R 6 is formula (2a), formula (2b) or formula (2c)

[0027] [ka]

[0028] (In formula (2a), formula (2b), or formula (2c), * indicates the bond position, R 7 ~R 11 each independently represents a hydrogen atom, a methyl group, or an ethyl group; X - represents a halide ion, Y represents a carbon atom or a sulfur atom, n represents 1 or 2, and M + indicates an alkali metal ion.) represents a monovalent group represented by the formula:

[0029] The monomer (A), the monomer (B), and the polymer will be explained in this order below.

[0030] [Monomer (A)] The monomer (A) applicable in the embodiment of the present invention may be any monomer as long as it is represented by the above general formula (1).

[0031] In general formula (1), R 1may be a hydrogen atom or a methyl group, but is preferably a hydrogen atom from the viewpoint of reactivity.

[0032] In general formula (1), R 2 is an alkylene group having 1 to 4 carbon atoms. The alkylene group having 1 to 4 carbon atoms may be a linear alkylene group or a branched alkylene group, but is preferably a linear alkylene group. The number of carbon atoms may be 1 to 4, but is preferably 2. Examples of linear alkylene groups having 1 to 4 carbon atoms include a methylene group (-CH2-), an ethylene group (-CH2-CH2-), a propylene group (-CH2-CH2-CH2-), and a butylene group (-CH2-CH2-CH2-CH2-), and of these, an ethylene group (-CH2-CH2-) is preferred.

[0033] In general formula (1), R 3 CO- has 2 to 30 carbon atoms and R 3 is an acyl group of an aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an alkyl group. Examples of alkyl groups constituting the acyl group having 2 to 30 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, ethylhexyl, nonyl, decyl, undecyl, lauryl (dodecyl), tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, stearyl (octadecyl), nonadecyl, eicosyl, heneicosyl, and behenyl groups. From the viewpoint of leveling ability and compatibility in the resin, R 3 The number of carbon atoms in CO- is preferably 2 to 22, more preferably 2 to 18. 3 The alkyl group may be straight-chain or branched, but is preferably straight-chain.

[0034] Only one type of monomer (A) may be contained, or two or more types may be contained.

[0035] The content of monomer (A) may be 10 to 80% by mass, preferably 30 to 70% by mass, when the total content of the constituent monomers (A) and (B) is 100% by mass. If the content of monomer (A) exceeds 80% by mass, the solubility in water and white marks tend to be easily generated. On the other hand, if the content of monomer (A) is less than 10% by mass, the leveling property tends to be deteriorated.

[0036] Monomer (A) can be produced, for example, by (1) subjecting (meth)acrylic acid and an alkanolamide to a dehydration esterification reaction in the presence of an acid catalyst, (2) subjecting a (meth)acrylic acid ester and an alkanolamide to a transesterification reaction in the presence of a transesterification catalyst, or (3) reacting acrylic acid chloride with an alkanolamide. The various conditions can be appropriately selected according to standard methods, depending on the type of catalyst used and the types of synthetic raw materials. However, from the viewpoints of suppressing impurities and storage stability, the catalyst used is preferably a metal complex catalyst, and more preferably a transition metal complex catalyst. Examples of metal complex catalysts include iron complexes, titanium complexes, and zirconium complexes. Examples of zirconium complexes include zirconium(IV) acetylacetonate, examples of titanium complexes include titanium acetylacetonate, and examples of iron complexes include iron(III) acetylacetonate. Alkanolamides prepared according to standard methods can be used.

[0037] [Monomer (B)] The monomer (B) applicable in the embodiment of the present invention may be any monomer as long as it is represented by the above general formula (2).

[0038] In formula (2), R 4 may be a hydrogen atom or a methyl group.

[0039] In formula (2), R 5represents an alkylene group having 1 to 6 carbon atoms. The alkylene group may be either linear or branched, and is preferably linear. From the viewpoint of leveling properties, the number of carbon atoms in the alkylene group is preferably 1 to 3. R 5 From the viewpoint of leveling properties, is preferably a linear alkylene group having 1 to 6 carbon atoms, more preferably a methylene group, an ethylene group, or a trimethylene group, and even more preferably an ethylene group.

[0040] In formula (2), R 6 is expressed by formula (2a), formula (2b), or formula (2c)

[0041] [ka]

[0042] (In formula (2a), formula (2b), or formula (2c), * indicates the bond position, R 7 ~R 11 each independently represents a hydrogen atom, a methyl group, or an ethyl group; X - represents a halide ion, Y represents a carbon atom or a sulfur atom, n represents 1 or 2, and M + indicates an alkali metal.) represents a monovalent group represented by the formula:

[0043] R 6 When a monomer (B) in which is a monovalent group represented by formula (2a) is used, from the viewpoint of solubility in water, this group preferably forms a salt with a hydrogen halide (i.e., a hydrohalide salt) in the polymer of the present invention. Examples of hydrogen halides include hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide.

[0044] The halide ion of the hydrogen halide salt of formula (2a) and X of formula (2b) - Examples of the ions include fluoride ions, chloride ions, bromide ions, and iodide ions. From the viewpoint of solubility in water, chloride ions (Cl- )

[0045] As the compound of formula (2a), 2-(dimethylamino)ethyl methacrylate or its hydrochloride is preferred, and as the compound of formula (2b), methacryloylcholine chloride is preferred.

[0046] R 6 When a monomer (B) is used in which M is a monovalent group represented by formula (2c), it is preferable that this group forms a salt with an alkali metal (i.e., an alkali metal salt) in the polymer of the present invention, from the viewpoint of ease of solubility of the polymer in water. + Examples of the cations include lithium ions, sodium ions, and potassium ions. From the viewpoint of solubility in water, sodium ions (Na + ) is preferred.

[0047] As the compound of formula (2c), sodium 2-(methacryloyloxy)ethane-1-sulfonate is preferred.

[0048] Only one type of monomer (B) may be contained, or two or more types may be contained. R of Monomer (B) 6 In view of solubility in water, the structure of formula (2b) or formula (2c) is preferred, and the structure of formula (2b) is particularly preferred.

[0049] The content of monomer (B) may be 20 to 90% by mass, preferably 30 to 70% by mass, when the total content of the constituent monomers, monomer (A) and monomer (B), is 100% by mass. If the content of monomer (B) exceeds 90% by mass, the leveling property tends to deteriorate. On the other hand, if the content of monomer (B) is less than 30% by mass, the solubility in water and the occurrence of white marks tend to increase.

[0050] The monomer (B) can be synthesized according to a conventional method, but commercially available products can also be used.

[0051] [Other monomer components] The polymer according to the embodiment of the present invention may contain a monomer component (hereinafter referred to as "monomer (C)") other than the monomer (A) and the monomer (B) as a constituent monomer. As the monomer (C), for example, a monomer having a radically polymerizable functional group such as an acryloyl group or a methacryloyl group as a reactive functional group is preferred, and a (meth)acrylic acid ester of a monoalcohol is more preferred. The monoalcohol preferably has 1 to 4 carbon atoms.

[0052] The content of the monomer (C) is preferably 0 to 40 parts by mass when the total content of the monomers (A) and (B) constituting the polymer is 100 parts by mass. If the content exceeds 40 parts by mass, the solubility in water and leveling properties tend to deteriorate.

[0053] [Polymer] The polymer according to the embodiment of the present invention may be composed of only one type selected from those containing monomer (A) and monomer (B) as constituent monomers in a predetermined range and having a predetermined weight average molecular weight, or may be a mixture of polymers composed of two or more types.

[0054] When the total of the monomers (A) and (B) in the polymer is 100% by mass, the content of each of the monomers (A) and (B) and the content of the monomer (C) can be calculated from the blending ratio of all the monomers.

[0055] The weight-average molecular weight of the polymer according to the present invention may be 3,000 to 3,000,000. The lower limit of the weight-average molecular weight is preferably 5,000, more preferably 10,000, and even more preferably 15,000. The upper limit of the weight-average molecular weight is preferably 300,000, more preferably 150,000, and even more preferably 100,000. If the weight-average molecular weight is lower than 3,000, the leveling ability tends to be insufficient, while if the weight-average molecular weight is higher than 3,000,000, the solubility in water and the occurrence of white marks tend to be increased. The weight-average molecular weight of the polymer can be determined in terms of polystyrene using gel permeation chromatography (GPC).

[0056] (Polymerization method) Next, a method for producing a polymer according to an embodiment of the present invention will be described. The polymer can be obtained, for example, by radical polymerization of a mixture of the above-mentioned various monomers in the presence of a polymerization initiator. The polymerization can be carried out by a known method. For example, solution polymerization, suspension polymerization, emulsion polymerization, etc. are mentioned, but solution polymerization is preferred in that the weight-average molecular weight of the polymer can be easily adjusted to fall within the above range.

[0057] As the polymerization initiator, known ones can be used. Examples of the peroxide include organic peroxides such as t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, methyl ethyl ketone peroxide, cyclohexanone peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, t-butylcumyl peroxide, and dicumyl peroxide; and azo compounds such as dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methyl-N-phenylpropionamidine) dihydrochloride, and 2,2'-azobis[N-(4-chlorophenyl)-2-methylpropionamidine] dihydrochloride. These polymerization initiators may be used alone or in combination of two or more.

[0058] The amount of the polymerization initiator used can be appropriately determined depending on the combination of monomers used, reaction conditions, and the like.

[0059] When polymerizing each of the above-mentioned monomers in the presence of a polymerization initiator, for example, the entire amount may be charged at once, or a portion may be charged at once and the remainder may be added dropwise, or the entire amount may be added dropwise. From the viewpoint of ease of heat generation control, it is preferable to charge a portion at once and the remainder may be added dropwise, or to add the entire amount dropwise. Furthermore, it is preferable to add a polymerization initiator after the monomer dropwise addition, since this can reduce the amount of residual monomer.

[0060] The polymerization solvent used in solution polymerization can be one that dissolves the monomer and polymerization initiator, and specific examples include toluene, xylene, isopropanol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, and water. In particular, isopropanol is preferably used from the viewpoint of solubility. Only one solvent may be used, or two or more solvents may be used in combination.

[0061] The concentration of the monomers (total amount) relative to the polymerization solvent is preferably 20 to 80% by mass, more preferably 25 to 80% by mass. If the monomer concentration is too low, the monomers tend to remain, which may result in a decrease in the molecular weight of the resulting polymer, whereas if the monomer concentration is too high, it may become difficult to control heat generation.

[0062] The polymerization temperature can be appropriately set depending on the type of monomer and the type of polymerization solvent, and is preferably 50 to 130° C., more preferably 60 to 90° C. The solution polymerization time is preferably 3 to 15 hours, more preferably 5 to 10 hours.

[0063] The polymer obtained as described above may be used as a polymer solution as it is, or may be isolated by subjecting the reaction solution after the polymerization reaction to filtration, purification, and drying under reduced pressure.

[0064] <Surface conditioner for water-based paints> The surface conditioner for aqueous paints according to the embodiment of the present invention may contain the polymer described above. Therefore, it may consist solely of the polymer described above, or it may contain other surface conditioners and / or other components whose active ingredients are components other than the polymer described above. Examples of other surface conditioners include silicone-based resins, acrylic silicone-based resins, acrylic resins, surfactants, silica, etc. Examples of other components include non-reactive resins (plasticizers, low-stress agents, etc.), antioxidants, UV absorbers, fillers, etc. The other surface conditioners and other components may be used alone or in combination of two or more. The amount of other surface conditioners and other components, if any, can be determined appropriately depending on the intended use.

[0065] Since the aforementioned polymer does not contain fluorine atoms, it is possible to provide a surface conditioner for water-based paints that does not contain fluorine raw materials and has a low environmental impact by ensuring that other surface conditioners and other components do not contain fluorine raw materials.Furthermore, although the surface conditioner for water-based paints that contains the aforementioned polymer does not contain fluorine raw materials, it can impart leveling properties to resin compositions such as the curable resin composition described below to the same extent as conventional fluorine-based surface conditioners, and is particularly suitable as a leveling agent for resins.

[0066] <Curable resin composition> The curable resin composition according to the embodiment of the present invention contains the above-described polymer and curable resin. The above-described polymer may be contained in the curable resin composition by using a surface conditioner for aqueous paint, or the polymer may be used as is. Preferred examples of the polymer include acrylic resin, acrylic / silicone resin, and acrylic / styrene resin, and more preferably, acrylic / silicone resin in view of its solubility in water.

[0067] In the curable resin composition, the content of the polymer is 0.1 to 50 parts by mass, preferably 0.2 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the curable resin, from the viewpoint of improving leveling properties and suppressing the occurrence of white marks.

[0068] The curable resin usable in the curable resin composition according to the embodiment of the present invention is not particularly limited, and examples thereof include thermosetting resins, photocurable resins, etc. Only one type of curable resin may be used, or two or more types may be used in combination. In this specification, curable compounds that do not have the properties of a resin, such as low-molecular-weight monofunctional acrylic monomers, are also referred to as curable resins.

[0069] Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins, etc. Furthermore, the thermosetting resin is not particularly limited to these, and any known thermosetting resin can be used.

[0070] Examples of photocurable resins include resins having a vinyl group, a vinyl ether group, an allyl group, a maleimide group, a (meth)acryloyl group, etc. Examples include poly(meth)acrylic acid resins, polyvinyl ether resins, urethane acrylate resins, epoxy acrylate resins, polyester acrylate resins, alicyclic epoxy resins, and glycidyl epoxy resins.

[0071] The curable resin composition according to the embodiment of the present invention may contain a polymerization initiator depending on the type of the curable resin, etc. The polymerization initiator is a compound that serves as a starting point for the polymerization reaction of the curable resin, and any known polymerization initiator can be used.

[0072] When a photocurable resin is used as the curable resin, a photopolymerization initiator can be used. When a photopolymerization initiator is used, the wavelength of the light to be irradiated is not particularly limited, but an initiator suitable for the wavelength can be selected and used. The photopolymerization initiators in the present invention can be used alone or in combination of two or more.

[0073] Examples of the photopolymerization initiator that can be used include aromatic ketones such as benzophenone; quinones such as alkylanthraquinone and phenanthrenequinone; benzoin compounds such as alkylbenzoin; benzil derivatives such as benzil dimethyl ketal; 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer; acridine derivatives such as 9-phenylacridine; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)]; coumarin compounds such as 7-diethylamino-4-methylcoumarin; thioxanthone compounds such as 2,4-diethylthioxanthone; and acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0074] When a thermosetting resin is used as the curable resin, a thermal polymerization initiator can be used. When a thermal polymerization initiator is used, the polymerization initiator used in synthesizing the above-mentioned polymer can be used.

[0075] The content of the polymerization initiator in the curable resin composition is preferably 0.01 to 50 parts by mass, and more preferably 0.1 to 15 parts by mass, relative to 100 parts by mass of the curable resin.

[0076] The curable resin composition according to the embodiment of the present invention may contain water or a solvent as long as the effect of the present invention is not impaired. and other ingredients can be added.

[0077] As the solvent, known solvents can be used. Examples include water, methyl alcohol, ethyl alcohol, acetone, methyl ethyl ketone, and tetrahydrofuran. One solvent may be used alone, or two or more solvents may be used in combination. When a solvent is used, the content is preferably 30 to 400 parts by weight, more preferably 50 to 300 parts by weight, per 100 parts by weight of the curable resin. By using water as a solvent for the cured resin composition, the cured resin composition can be used as a water-based paint, and by diluting the cured resin composition with water, it is also possible to make it into a water-based resin.

[0078] Examples of other components include heat resistance improvers, development aids, inorganic fine particles, coupling agents, fillers, curing agents, plasticizers, polymerization inhibitors, antioxidants, antifoaming agents, viscosity modifiers, and pigments. One or more of these other components may be used alone, or two or more may be used in combination. The content of these other components is preferably 0 to 20 parts by weight, more preferably 0 to 15 parts by weight, and even more preferably 0 to 10 parts by weight, based on the total curable resin composition.

[0079] <Cured film> A cured film can be obtained by curing the curable resin composition. The cured film can be obtained by various known methods. For example, a cured film can be obtained by applying the curable resin composition to the surface of a substrate to form a coating film and then curing the curable resin. The method for applying the curable resin composition is not particularly limited, and examples include methods using a coating device such as a spin coater, spray coater, slit coater, or inkjet. A cured film can be obtained by applying the curable resin composition to a substrate and then undergoing steps such as drying, pre-baking, photo-curing, developing, water washing, and post-baking, which are appropriately selected depending on the type of curable resin. The curing conditions for the curable resin can be appropriately determined depending on the type and blending ratio of each component.

[0080] The curable resin composition of the present invention can be applied to various plastic materials, etc., and by using the coating composition of the present invention, it is possible to provide a coated object having a coating film that has excellent leveling performance and is less likely to produce white marks even after curing. The above-mentioned curable resin composition is suitable for water-based coatings such as coatings for automotive materials, furniture, and home appliances. [Example]

[0081] Hereinafter, the embodiments of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0082] Synthesis Example 1-1: Synthesis of compound (a-1) represented by the following formula (a-1)

[0083] [ka]

[0084] In a four-neck flask (500 mL) equipped with a condenser, 330 g (2.55 mol) of caprylic acid (NOF Corporation "NAA-82") and 310 g (5.10 mol) of monoethanolamine were placed. Nitrogen gas was introduced into the resulting reaction solution to replace the atmosphere in the reaction vessel with nitrogen. The reaction solution was then heated to 150°C while being stirred, and the reaction was initiated. The reaction was then continued for 8 hours, and the completion of the reaction was confirmed. 1 The reaction mixture was confirmed by 1 H NMR. Thereafter, the remaining monoethanolamine was distilled off to obtain the target compound (a-1).

[0085] 1 The H-NMR measurement conditions are as follows: Equipment: JEOL400YH (400MHz) manufactured by JEOL Ltd. Solvent: deuterated chloroform

[0086] Synthesis Example 1-2: Synthesis of Monomer (A-1) Represented by the Following Formula (A-1)

[0087] [ka]

[0088] Monomer (A-1) was synthesized with reference to the method described in JP-A-2005-502698. Specifically, 80 g of compound (a-1) obtained in Synthesis Example 1-1, 302 g (3.02 mol) of methyl acrylate, 2.20 g (2% by mass based on the reaction mixture) of a catalyst (zirconium (IV) acetylacetonate), and 0.62 g of stabilizers (Irganox 1076 and 0.012 g of 4-hydroxy-2,2,6,6-tetramethylpiperidinooxyl) were placed in a four-neck flask (500 mL) equipped with a condenser, and a transesterification reaction was carried out at 100 to 120°C to synthesize Monomer (A-1).

[0089] Synthesis Example 2-2: Synthesis of Monomer (A-2) Represented by the Following Formula (A-2)

[0090] [ka]

[0091] Monomer (A-2) was synthesized in the same manner as in Synthesis Example 1-2, except that 2-acetamidoethanol and methacrylic acid chloride were used as reactants.

[0092] Synthesis Example 3-2: Synthesis of Monomer (A-3) Represented by the Following Formula (A-3)

[0093] [ka]

[0094] Monomer (A-3) was synthesized in the same manner as in Synthesis Example 1-2, except that N-(2-hydroxyethyl)propionamide and methacrylic acid chloride were used as reactants.

[0095] Synthesis Example 4-2: Synthesis of Monomer (A-4) Represented by the Following Formula (A-4)

[0096] [ka]

[0097] Monomer (A-4) was synthesized in the same manner as in Synthesis Example 1-2, except that caprylic acid was changed to stearic acid as the reactant.

[0098] Synthesis Example 5-2: Synthesis of Monomer (A-5) Represented by the Following Formula (A-5)

[0099] [ka]

[0100] Monomer (A-5) was synthesized in the same manner as in Synthesis Example 1-2, except that caprylic acid was changed to 2-ethylhexanoic acid as the reactant.

[0101] In the comparative examples described below, lauryl methacrylate (NOF Corporation, "Blenmer LA") was used as the monomer (A'-1) instead of the monomer (A).

[0102] In the examples and comparative examples described below, the following commercially available products were used as the monomer (B). Monomer (2a) was prepared using Monomer (B-1): 2-(dimethylamino)ethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., "2-(Dimethylamino)ethyl Methacrylate (stabilized with MEHQ)"). Monomer (2b) includes monomer (B-2): methacroylcholine chloride (Tokyo Chemical Industry Co., Ltd., "Methacroylcholine Chloride (ca. 80% in Water) (stabilized with MEHQ)") Monomer (2c) was prepared using Monomer (B-3): sodium 2-(methacryloyloxy)ethane-1-sulfonate (NOF Corporation, "Blenmer IA-MA"). Monomer (B'-1): 2-Hydroxyethyl methacrylate (ethylene glycol methacrylate) (Tokyo Chemical Industry Co., Ltd., "2-Hydroxyethyl Methacrylate (stabilized with MEHQ")

[0103] (Polymerization Example 1) In a four-neck flask (100 mL) equipped with a condenser, 11.2 g of monomer (A-1), 4.8 g of monomer (B-1), 1.6 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601), and 60.0 g of 2-propanol were placed. Nitrogen gas was introduced into the resulting reaction solution to replace the atmosphere inside the reaction vessel with nitrogen. The reaction solution was then heated to 75°C while stirring, and the reaction was initiated. The reaction was then continued for 6 hours, and the completion of the reaction was confirmed. 1 The reaction mixture was confirmed by H NMR. After that, 1.5 g of 12 M hydrochloric acid (1.1 equivalents relative to the monomer (B-1)) was added to the reaction vessel, and then reprecipitation purification was carried out using a large amount of acetone. The recovered precipitate was dried under reduced pressure at 120°C to obtain polymer 1.

[0104] (Polymerization Example 2) In a four-neck flask (100 mL) equipped with a condenser, 11.2 g of monomer (A-1), 6.0 g of monomer (B-2), 1.6 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601), and 60.0 g of 2-propanol were placed. Nitrogen gas was introduced into the resulting reaction solution to replace the atmosphere in the reaction vessel with nitrogen. The reaction solution was then heated to 75°C while stirring, and the reaction was initiated. The reaction was then continued for 6 hours, and the completion of the reaction was confirmed. 1 The reaction mixture was confirmed by H NMR. Thereafter, reprecipitation purification was carried out using a large amount of butyl acetate, and the collected precipitate was dried under reduced pressure at 120°C to obtain polymer 2.

[0105] (Polymerization Example 3) In a four-neck flask (100 mL) equipped with a condenser, 11.2 g of monomer (A-1), 4.8 g of monomer (B-3), 1.6 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601), and 60.0 g of 2-propanol were placed. Nitrogen gas was introduced into the resulting reaction solution to replace the atmosphere inside the reaction vessel with nitrogen. The reaction solution was then heated to 75°C while stirring, and the reaction was initiated. The reaction was then continued for 6 hours, and the completion of the reaction was confirmed. 1The reaction mixture was confirmed by H NMR. Thereafter, reprecipitation purification was carried out using a large amount of butyl acetate, and the collected precipitate was dried under reduced pressure at 120°C to obtain polymer 3.

[0106] (Polymerization Examples 4 and 5) Polymers 4 and 5 were obtained in the same manner as Polymer 2, except that the raw materials were added in the blending ratios shown in the table (the blending amounts in the table are in parts by mass).

[0107] (Polymerization Examples 6 to 10) Polymers 6 to 10 were obtained in the same manner as for Polymer 2, except that Monomers (A-2) to (A'-1) were used instead of Monomer (A-1).

[0108] (Polymerization Example 11) Polymer 11 was obtained in the same manner as in Polymer 3, except that the amount of Monomer (B'-1) shown in Table 1 was used.

[0109] (Polymerization Examples 12 and 13) Polymers 12 and 13 were obtained in the same manner as Polymer 2, except that the raw materials were added in the blending ratios shown in Table 1 (the blending amounts in the table are in parts by mass).

[0110] [Measurement of weight average molecular weight] The weight average molecular weights of polymers 1 to 13 were determined using gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh Corporation, HLC-8220 Column: Shodex LF-804 Standard material: polystyrene Eluent: THF (tetrahydrofuran) Flow rate: 1.0mL / min Column temperature: 40℃ Detector: RID (refractive index detector)

[0111] Table 1 shows the types and contents of Monomer A, Monomer B and polymerization initiator constituting Polymers 1 to 13, as well as the weight average molecular weight of the polymers.

[0112] [Table 1]

[0113] Example 1 <Preparation of water-based surface conditioner> An aqueous surface conditioner was obtained by mixing 95 parts by mass of ion-exchanged water with 5 parts by mass of polymer 1. The obtained aqueous surface conditioner was used to carry out the following evaluations.

[0114] (Examples 2 to 9, Comparative Examples 1 to 4) Aqueous surface conditioners were obtained in the same manner as in Example 1, except that the formulations shown in Table 2 were used, and the various evaluations were carried out.

[0115] (Comparative Example 5) An aqueous surface conditioner was obtained in the same manner as in Example 1, except that "Surfynol 465 (an adduct of 2,4,7,9-tetramethyl-5-decyne-4,7-diol with 10 moles of ethylene oxide, manufactured by Air Products Japan Co., Ltd.)" was used as the surfactant instead of Polymer 1, and various evaluations were carried out.

[0116] <Evaluation of water-based surface conditioners> <Solubility> The appearance of the aqueous surface conditioner was visually inspected at 25°C to confirm its solubility. ○: No solid matter was visually observed. ×: Solid matter was visually observed.

[0117] <Dynamic surface tension> Dynamic surface tension measurements were carried out on water-based surface conditioners. Using a KRUSS BP-2 bubble pressure dynamic surface tension system, the surface tension was measured at 25°C after an interface life of 10,000 ms. ◎: Less than 35mN / m ○: 35mN / m or more and less than 41mN / m △: 41mN / m or more and less than 51mN / m ×: 51mN / m or more

[0118] [Table 2]

[0119] Example 10 <Preparation of curable resin composition and evaluation of cured film> A curable resin composition was prepared by mixing 99 parts by mass of the aqueous thermosetting resin "Movinyl (registered trademark) 7110" (manufactured by Japan Coating Resins Co., Ltd., solid content (curable resin content) 46%) as the curable resin and 1 part by mass of polymers 1 to 13 or the surfactant used in Comparative Example 5. Next, 1 g of the curable resin composition was applied to a polycarbonate plate using a bar coater (RDS 32) and dried on a hot plate at 80°C for 1 hour to form a cured film of the curable resin composition. The physical properties of the resulting cured film were investigated using the following procedures. The results are shown in Table 3.

[0120] <Leveling ability> The resulting cured film was subjected to stylus surface roughness measurement. The surface roughness was measured using a DetakXT manufactured by BRUKER. The arithmetic mean roughness (Pa) was evaluated under the following conditions. The smaller the Pa value, the smaller the surface irregularities and the better the smoothness (leveling ability). ○: Less than 0.25 μm ×: 0.25μm or more

[0121] <Whitening marks> The appearance of the obtained cured film was visually inspected to check for any whitening. ◯: No traces of whitening were found on the coating film by visual inspection. ×: Whitening was visually observed on the coating film.

[0122] <Total light transmittance> The total light transmittance of the resulting cured film was measured. Evaluation was carried out according to JIS K 7361 using NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd. ◎: 94% or more ○: 90% or more but less than 94% △: 85% or more but less than 90% ×: Less than 85% ◎ and 〇 are considered passing marks.

[0123] [Table 3]

[0124] The results shown in Table 2 show that polymers 1 to 9 were soluble in water and exhibited good dynamic surface tension. Furthermore, the results shown in Table 3 indicate that all of the cured films obtained from the curable resin compositions containing polymers 1 to 9 exhibited good leveling properties, and also showed good results in terms of whitening marks and total light transmittance. Therefore, it is clear that polymers 1 to 9 are suitable as surface conditioners for water-based paints.

[0125] On the other hand, in Comparative Example 1, since Monomer A'-1 was used instead of Monomer A, Polymer 10 was dissolved in water, but good dynamic surface tension could not be obtained. Furthermore, the evaluation of the cured film obtained from the curable resin composition containing Polymer 10 also showed results inferior to those of the curable resin compositions containing Polymers 1 to 9.

[0126] In Comparative Example 2, Monomer B'-1 was used instead of Monomer B, so Polymer 11 was insoluble in water, had high dynamic surface tension, and the evaluation of the cured film was inferior to Polymers 1 to 9.

[0127] In Comparative Example 3, since the parts by mass of Monomer A were high and the parts by mass of Monomer B were low, Polymer 12 did not dissolve in water, the dynamic surface tension was high, and the evaluation of the cured film was inferior to Polymers 1 to 9.

[0128] In Comparative Example 4, the mass parts of Monomer A were low and the mass parts of Monomer B were high, so Polymer 13 was soluble in water, but the dynamic surface tension was high, and the evaluation of the cured film was inferior to Polymers 1 to 9.

[0129] In Comparative Example 5, a surfactant was used instead of a polymer, and the composition was soluble in water and showed good dynamic surface tension, but white marks occurred in the cured film and the total light transmittance was unacceptable.

Claims

1. A polymer containing, as constituent monomers, a monomer (A) represented by the following general formula (1) and a monomer (B) represented by the following general formula (2), wherein the polymer contains, as constituent units, 10 to 80 mass% of the monomer (A) and 20 to 90 mass% of the monomer (B), relative to 100 mass% of the total of the monomers constituting the polymer, and has a weight average molecular weight of 3,000 to 3,000,000. 【Chemistry 1】 (In formula (1), R １ represents a hydrogen atom or a methyl group, and R ２ represents an alkylene group having 1 to 4 carbon atoms, and R ３ CO- has 2 to 30 carbon atoms, and R ３ represents an acyl group of an aliphatic hydrocarbon group.) 【Chemistry 2】 (In formula (2), R ４ represents a hydrogen atom or a methyl group, and R ５ represents an alkylene group having 1 to 6 carbon atoms, and R ６ is represented by formula (2a), formula (2b), or formula (2c) 【Transformation 3】 (In formula (2a), formula (2b), or formula (2c), * indicates the bond position, R ７ ~R １１ each independently represents a hydrogen atom, a methyl group, or an ethyl group; X － represents a halide ion, Y represents a carbon atom or a sulfur atom, n represents 1 or 2, and M ＋ indicates an alkali metal ion.) represents a monovalent group represented by the formula:

2. A surface conditioner for water-based paints, comprising the polymer according to claim 1.

3. A curable resin composition comprising 0.1 to 50 parts by mass of the polymer according to claim 1 relative to 100 parts by mass of a curable resin.

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