Freeze-thaw stability improver and adhesion improver

Abstract

To provide a freeze-thaw stabilizer capable of improving freeze-thaw stability of a polymer emulsion, and an adhesion improver capable of improving adhesion between a polymer and a substrate.SOLUTION: The freeze-thaw stabilizer or adhesion improver is represented by general formula (1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an agent for improving freeze-thaw stability, and more specifically to an agent for improving the freeze-thaw stability of a polymer emulsion obtained by emulsion polymerization of a monomer. [Background technology]

[0002] Conventionally, methods have been proposed for producing polymers such as acrylic acid ester polymers, ethylene-vinyl acetate copolymers, styrene-butadiene copolymers, or styrene-acrylonitrile copolymers by emulsion polymerization using various surfactants. For example, emulsion polymerization methods using anionic surfactants such as long-chain alkyl sulfates, long-chain alkylbenzene sulfonates, polyoxyethylene alkylphenyl ether sulfates, and alkyldiphenyl ether disulfonates, or nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, and Pluronic (registered trademark) type surfactants, are known.

[0003] Essentially, surfactants used in the production of polymer emulsions are not only involved in the initiation reaction of polymerization and the reaction of forming a polymer, but also deeply involved in the stabilization of the polymer emulsion during polymerization, the conversion rate of the monomer, the mechanical stability, chemical stability, freeze-thaw stability, pigment miscibility, storage stability, etc. of the formed polymer emulsion. In addition, they also greatly affect the physical properties of the polymer particles in the emulsion, such as particle size, viscosity, and foamability, and therefore it is essential to select a surfactant suitable for the intended use.

[0004] For example, Patent Document 1 discloses an emulsifier for emulsion polymerization that has an ion-bonding salt having a reactive group, and discloses that the use of this surfactant can provide sufficient polymerization stability during emulsion polymerization and improve the water resistance and weather resistance of a thermoplastic resin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2013 / 129492 Summary of the Invention [Problem to be solved by the invention]

[0006] However, according to the studies of the present inventors, it was found that when the surfactant disclosed in Patent Document 1 is used, the polymer in the emulsion state does not achieve sufficient freeze-thaw stability, and sufficient adhesion between the polymer and the substrate may not be achieved.

[0007] Therefore, the present invention aims to solve such problems and has an object to provide a freeze-thaw stability improver capable of improving the freeze-thaw stability of a polymer emulsion. Furthermore, the present invention has an object to provide an adhesion improver capable of improving the adhesion between a polymer derived from the polymer emulsion and a substrate. [Means for solving the problem]

[0008] As a result of intensive research, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention.

[0009] That is, one aspect of the present invention relates to a freeze-thaw stability improver for a polymer emulsion (hereinafter, also simply referred to as a “freeze-thaw stability improver”), which contains a compound represented by the following general formula (1):

[0010] [ka]

[0011] In the general formula (1), Q + is a nitrogen-containing compound cation, A is a linear or branched alkylene group having 2 to 4 carbon atoms; m represents the average number of moles of AO added and is a number from 1 to 150; Y is a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms; R1 is a hydrogen atom or a methyl group; R2 is a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 25 carbon atoms, or a group represented by the following general formula (2): l is an integer from 1 to 3;

[0012] [ka]

[0013] In general formula (2), R3 and R4 each independently represent a hydrogen atom or a methyl group, and * represents a connecting point.

[0014] Furthermore, another aspect of the present invention relates to an adhesion improver between a polymer and a substrate (hereinafter also simply referred to as "adhesion improver"), which contains a compound represented by the above general formula (1). Effect of the Invention

[0015] According to the present invention, it is possible to further improve the freeze-thaw stability of a polymer emulsion obtained by emulsion polymerization and the adhesion between a polymer derived from the polymer emulsion and a substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described.

[0017] The freeze-thaw stability improver and adhesion improver according to the present invention contain a compound represented by the following general formula (1) as an active ingredient.

[0018] [ka]

[0019] In the general formula (1), Q+ is a nitrogen-containing compound cation, A is a linear or branched alkylene group having 2 to 4 carbon atoms; m represents the average number of moles of AO added and is a number from 1 to 150; Y is a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms; R1 is a hydrogen atom or a methyl group; R2 is a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 25 carbon atoms, or a group represented by the following general formula (2): l is an integer from 1 to 3;

[0020] [ka]

[0021] In general formula (2), R3 and R4 each independently represent a hydrogen atom or a methyl group, and preferably at least one of R3 and R4 is a methyl group, and * represents a connecting point.

[0022] Examples of the linear or branched alkylene group having 2 to 4 carbon atoms used as A in the general formula (1) include an ethylene group, a propylene group, a butylene group, etc. From the viewpoint of availability, an ethylene group and a propylene group are particularly preferred.

[0023] In the general formula (1), m is a number from 1 to 150. From the viewpoint of ease of handling due to reduced viscosity, etc., or interfacial properties, m is preferably 1 to 50, and more preferably 5 to 50.

[0024] Examples of the linear or branched alkylene group having 1 to 5 carbon atoms used as Y in the general formula (1) include a methylene group, an ethylene group, a propylene group, a butylene group, etc. From the viewpoint of availability, a methylene group, an ethylene group, and a propylene group are particularly preferable.

[0025] Examples of the substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 25 carbon atoms used as R2 in the general formula (1) include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isoamyl group, a tert-pentyl group, a neopentyl group, an n-hexyl group, a 3-methylpentan-2-yl group, a 3-methylpentan-3-yl group, a 4-methylpentyl group, a 4-methylpentan-2-yl group, a 1,3-dimethylbutyl group, a 3,3-dimethyl n-butyl, 3,3-dimethylbutan-2-yl, n-heptyl, 1-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-ethylpentyl, 1-(n-propyl)butyl, 1,1-dimethylpentyl, 1,4-dimethylpentyl, 1,1-diethylpropyl, 1,3,3-trimethylbutyl, 1-ethyl-2,2-dimethylpropyl, n-octyl, 2-methylhexan-2-yl, 2,4-dimethylpentan-3-yl, 1,1-dimethylpentan-1-yl, 2,2-dimethyl Hexan-3-yl group, 2,3-dimethylhexan-2-yl group, 2,5-dimethylhexan-2-yl group, 2,5-dimethylhexan-3-yl group, 3,4-dimethylhexan-3-yl group, 3,5-dimethylhexan-3-yl group, 1-methylheptyl group, 2-methylheptyl group, 5-methylheptyl group, 2-methylheptan-2-yl group, 3-methylheptan-3-yl group, 4-methylheptan-3-yl group, 4-methylheptan-4-yl group, 1-ethylhexyl group, 2-ethylhexyl group, 1-propylpentyl group, 2-propylpentyl group, 1,1-dimethylhexyl group, 1,4-dimethylhexyl group, 1,5-dimethylhexyl group, 1-ethyl-1-methylpentyl group, 1-ethyl-4-methylpentyl group, 1,1,4-trimethylpentyl group, 2,4,4-trimethylpentyl group, 1-isopropyl-1,2-dimethylpropyl group, 1,1,3,3-tetramethylbutyl group, n-nonyl group, 1-methyloctyl group, 6-methyloctyl group, 1-ethylheptyl group, 1-(n-butyl)pentyl group, 4-methyl-1-(n-propyl)pentyl group, 1,5,5-trimethylhexyl group, 1,1,Examples of the substituents include 5-trimethylhexyl, 2-methyloctane-3-yl, n-decyl, 1-methylnonyl, 1-ethyloctyl, 1-(n-butyl)hexyl, 1,1-dimethyloctyl, 3,7-dimethyloctyl, n-undecyl, 1-methyldecyl, 1-ethylnonyl, n-dodecyl, n-tridecyl, n-tetradecyl, 1-methyltridecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl. Examples of the substituents in the linear, branched, or cyclic alkyl groups having 1 to 25 carbon atoms include fluorine, chlorine, bromine, and iodine. Among these, from the viewpoint of availability, substituted or unsubstituted methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, branched octyl (e.g., 2-ethylhexyl, 1,1,3,3-tetramethylbutyl), branched nonyl (e.g., 1-methyloctyl, 6-methyloctyl, 1-ethylheptyl), branched dodecyl, and branched tridecyl groups are preferred, with tert-butyl, branched octyl, branched nonyl, and branched dodecyl being more preferred. Long-chain alkyl groups such as nonyl, decyl, undecyl, dodecyl, tridecyl, and tetradecyl are generally present in a branched form or as a mixture of linear and branched forms (mixture of structural isomers), and these forms are also within the scope of the present invention.

[0026] Q in the general formula (1) + Examples of the nitrogen-containing compound cation used as the cation include an ammonium ion, a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, a quaternary ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, a quinolinium ion, a morpholinium ion, and an imidazolidinonium ion (ethylene urea).

[0027] Among them, examples of tertiary ammonium ions include nitrogen-containing compound cations represented by the following general formula (3):

[0028] [ka]

[0029] In general formula (3), R5 and R6 are each independently a linear or branched alkyl group having 1 to 4 carbon atoms, R7 is a linear or branched alkylene group having 2 to 4 carbon atoms, X is an oxygen atom or NH, and R8 is a hydrogen atom or a methyl group.

[0030] Examples of the linear or branched alkyl group having 1 to 4 carbon atoms used as R5 and R6 in the general formula (3) include a methyl group, an ethyl group, a propyl group, a butyl group, etc. From the viewpoint of availability, a methyl group, an ethyl group, and a butyl group are particularly preferred.

[0031] Examples of the linear or branched alkylene group having 2 to 4 carbon atoms used as R7 in the general formula (3) include an ethylene group, a propylene group, a butylene group, etc. From the viewpoint of availability, an ethylene group and a propylene group are particularly preferred.

[0032] More preferred compounds of the freeze-thaw stability improver or adhesion improver represented by the general formula (1) include compounds represented by the following chemical formulas (4) to (7).

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] In the chemical formulas (4) to (7), R1, R2, R5 to R8, X, Y, A, m, and l are defined as above.

[0038] The method for producing the compound that is the active ingredient of the freeze-thaw stability improver or adhesion improver is not particularly limited, and examples thereof include anion exchange method, neutralization method, acid ester method, etc. Also preferably used is a deammonification method in which an ammonium salt of sulfate ester or ammonium salt of sulfonate is reacted with a nitrogen-containing compound and ammonia is distilled off to obtain an ionic salt having a reactive group.

[0039] The uses of the above compound as a freeze-thaw stability improver and an adhesion improver will be described in detail below.

[0040] (Emulsion Polymerization) The method of using the freeze-thaw stability improver or adhesion improver is not particularly limited, but for example, by adding it to the reaction system during emulsion polymerization, it can contribute to the purpose of improving the freeze-thaw stability of the obtained polymer emulsion and improving the adhesion between the polymer, which is the dried product of the polymer emulsion, and the substrate.The specific form of adding these agents (compounds) to the reaction system during emulsion polymerization is also not particularly limited, and includes a form of dropping into the monomer mixture for emulsion polymerization, and a method of mixing into the monomer mixture in portions or all at once.

[0041] When a molded article is produced using a polymer obtained by emulsion polymerization or the like using the freeze-thaw stability improver or adhesion improver according to the present invention, the polymer emulsion obtained by emulsion polymerization can have excellent freeze-thaw stability. In addition, a molded article produced using the polymer emulsion can have excellent adhesion to a substrate. Although it is only a guess, the effect of improving the freeze-thaw stability of the polymer emulsion is believed to be due to the inclusion of a specific type of compound having a bulky hydrophobic group (e.g., a polycyclic structure) as an active ingredient. Specifically, in the melting stage of the freeze-thaw process in the polymer emulsion, polymer particles having a high Tg are easy to return to a normal state, but particles having a relatively low Tg are difficult to return from a gelled aggregated state or a coalesced state. The freeze-thaw stability improver according to the present invention can form a protective layer on the surface of soft polymer particles based on the steric effect of the relatively large hydrophobic group, stabilizing the polymer particles to a certain extent. It is believed that large hydrophobic groups that are adsorbed or grafted onto or copolymerized into the polymer particles can prevent these polymer particles from approaching the surfaces of other flexible polymer particles, increasing the separation distance between the flexible polymer particles.

[0042] There is no particular limitation on the monomer (polymerizable monomer) that can be emulsion-polymerized using the freeze-thaw stability improver or adhesion improver according to the present invention, and conventionally known polymerizable monomers can be used. Examples of such monomers include acrylic acid or methacrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate; vinyl halides such as vinyl bromide, vinyl chloride, and vinylidene chloride; vinyl esters of fatty acids such as acetic acid, propionic acid, and tertiary synthetic saturated carboxylic acids; aromatic vinyls such as styrene and α-methylstyrene; monoolefins or conjugated diolefins such as ethylene and butadiene; vinyl cyanides such as acrylonitrile; α,β-unsaturated amides such as acrylamide; and α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid.

[0043] As the polymerization initiator, any initiator normally used for emulsion polymerization can be used without any particular limitation. For example, inorganic peroxides such as persulfates or perborates of potassium, sodium or ammonium, and hydrogen peroxide; organic peroxides such as benzoyl peroxide, di-t-butyl peroxide, and peracetic acid; and radical-generating polymerization initiators such as 2,2-azobisisobutyronitrile, 4-azobis-(4-cyanopentanoic) acid or an alkali metal salt thereof can be used. The amount of the initiator used is preferably 0.01 to 3.0% by mass, more preferably 0.1 to 2.0%, and even more preferably 0.1 to 1.0% by weight based on the polymerizable monomer.

[0044] In addition, when a peroxide is used as a polymerization initiator, if necessary, the peroxide can be used in combination with a reducing agent such as ascorbic acid, a soluble sulfite, a hydrosulfite, or a thiosulfate. Also, the peroxide can be used as a redox polymerization initiator in combination with a metal monomer that generates heavy metal ions in water or a metal compound that generates metal ions in water, such as ferrous sulfate.

[0045] A chain transfer agent may also be used in combination, such as t-dodecyl mercaptan, dodecyl mercaptan, carbon tetrachloride, chloroform, triphenylmethane, or the like.

[0046] Furthermore, additives conventionally used in emulsion polymerization techniques can be used, such as chelating agents, buffers, salts of organic acids, solvents, etc. As the solvent, in addition to water, organic solvents such as alcohols, glycols, glycol ethers, etc. can be used, but water is preferably used as the solvent.

[0047] In addition, the compound represented by the general formula (1) is not only effective in improving the freeze-thaw stability or adhesion, but is also used as an emulsifier for emulsion polymerization or an antifoaming agent. Therefore, emulsion polymerization can be carried out using the freeze-thaw stability improver or adhesion improver of the present invention. In this case, the freeze-thaw stability improver or adhesion improver of the present invention may be used alone, or other emulsifiers or additives for emulsion polymerization may be used in combination.

[0048] In emulsion polymerization using the freeze-thaw stability improver or adhesion improver according to the present invention, the freeze-thaw stability improver or adhesion improver represented by the general formula (1) can fully exert its function alone, but if necessary, it can also be used in combination with a conventionally known surfactant, reactive emulsifier, polymer emulsifier, protective colloid, etc. Examples of surfactants that can be used in combination include anionic surfactants such as long-chain alkyl sulfates, polyoxyalkylene alkyl ether sulfates, long-chain alkyl benzene sulfonates, polyoxyalkylene alkyl phenyl ether sulfates, and alkyl diphenyl ether disulfonates, and examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, polyoxyalkylene fatty acid esters, and Pluronic (registered trademark) type surfactants.

[0049] Examples of polymeric emulsifiers that can be used in combination include polyvinyl alcohol, poly(meth)acrylates, and polyhydroxyalkylene (meth)acrylates. Examples of protective colloids that can be used in combination include anionic protective colloids such as sodium alginate, and nonionic protective colloids such as hydroxyethyl cellulose.

[0050] The amount of the freeze-thaw stability improver or adhesion improver containing the compound represented by the general formula (1) according to the present invention is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5.0 parts by mass, and even more preferably 0.5 to 3.0 parts by mass, based on 100 parts by mass of the polymerizable monomer. The freeze-thaw stability improver or adhesion improver according to the present invention may contain only one compound represented by the general formula (1) alone, or may contain two or more compounds. When two or more compounds are used in combination, the above-mentioned preferred amount is the total amount of the compounds. Another effect of the freeze-thaw stability improver or adhesion improver represented by the general formula (1) according to the present invention is that emulsion polymerization can be sufficiently performed even with a small amount of addition, and further, the freeze-thaw stability or low foaming property of the polymer emulsion is excellent, and the adhesion between the polymer and the substrate can be improved.

[0051] The present invention also provides a polymer composition obtained by the above-mentioned emulsion polymerization. That is, according to another aspect of the present invention, a polymer composition is also provided that contains the freeze-thaw stability improver or adhesion improver of the present invention, a polymerizable monomer, and a solvent (particularly preferably water). The polymer composition is preferably in the form of an emulsion. EXAMPLES

[0052] The present invention will be described in more detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively. In the following examples, unless otherwise specified, the operations were performed under the conditions of room temperature (25°C) / relative humidity 40-50%RH.

[0053] (Synthesis example: Synthesis of emulsifier S1 for emulsion polymerization) To 157.2 parts by mass of N,N-dimethylaminoethyl methacrylate (abbreviation: 2Mabs-MA), 920.1 parts by mass of polyoxyethylene polycyclic phenyl ether sulfate ammonium salt (abbreviation: 707-SF) obtained by distilling water under reduced pressure from a 30% aqueous solution of polyoxyethylene polycyclic phenyl ether sulfate ammonium salt (manufactured by Nippon Nyukazai Co., Ltd., product name: Newcol (registered trademark) 707-SF, abbreviation: N-707-SF) was added, and the mixture was allowed to react for 1 hour. After the reaction, 1088.4 parts by mass of the target emulsion polymerization emulsifier S1 (abbreviation: emulsifier S1, a compound represented by the above chemical formula (6)) was obtained.

[0054] (Comparative Synthesis Example 1: Synthesis of emulsifier S2 for emulsion polymerization) Except for using 517.4 parts by mass of polyoxyethylene tridecyl ether sulfate ammonium salt (abbreviation: 1305-SF) synthesized by a conventional method instead of 707-SF, the same procedure as in Synthesis Example 1 was repeated to obtain 657.6 parts by mass of the target emulsifier S2 for emulsion polymerization (abbreviation: emulsifier S2).

[0055] (Comparative Synthesis Example 2: Synthesis of emulsifier S3 for emulsion polymerization) Except for using 1170.0 parts by mass of polyoxyethylene alkyl ether sulfate ammonium salt (abbreviation: 2320-SF) synthesized by a conventionally known method instead of 707-SF, the same procedure as in Synthesis Example was followed to obtain 1310.2 parts by mass of the target emulsifier S3 for emulsion polymerization (abbreviation: emulsifier S3).

[0056] Example 1 Composition A (methyl methacrylate (48) / n-butyl methacrylate (20) / 2-ethylhexyl acrylate (30) / acrylic acid (2) / α-methylstyrene dimer (0.2)) + emulsifier S1 Into a flask equipped with a stirrer, a reflux condenser, a temperature controller, a dropping pump and a nitrogen inlet tube, 130 parts by mass of ion-exchanged water and 0.2 parts by mass of emulsifier S1 were placed, and the reaction vessel was heated under a nitrogen stream.

[0057] When the temperature inside the reaction vessel reached 85°C, 3 parts by mass of a 2% by mass aqueous solution of ammonium persulfate was added and mixed for 5 minutes, after which monomer mixture 1 formulated as shown in Table 1 was added dropwise over 90 minutes. The temperature inside the reaction vessel was kept at 85°C during the dropwise addition. After the dropwise addition was completed, the mixture was aged at 85°C for 90 minutes.

[0058] Next, monomer mixture 2 formulated as shown in Table 1 was added dropwise over 90 minutes. The temperature inside the reaction vessel was kept at 85°C during the dropwise addition. After the dropwise addition was completed, the mixture was aged at 85°C for 90 minutes. It was then cooled to room temperature, and 25% aqueous ammonia was added to adjust the pH to 8.5, to obtain polymer emulsion E1.

[0059] [Table 1]

[0060] Example 2 Composition B (methyl methacrylate (35) / cyclohexyl methacrylate (31) / n-butyl methacrylate (12) / 2-ethylhexyl acrylate (20) / acrylic acid (1) / methyl acrylate (1) / α-methylstyrene dimer (0.2)) + emulsifier S1 Into a flask equipped with a stirrer, a reflux condenser, a temperature controller, a dropping pump and a nitrogen inlet tube, 130 parts by mass of ion-exchanged water and 0.2 parts by mass of emulsifier S1 were placed, and the reaction vessel was heated under a nitrogen stream.

[0061] When the temperature inside the reaction vessel reached 85°C, 3 parts by mass of a 2% by mass aqueous solution of ammonium persulfate was added and mixed for 5 minutes, after which monomer mixture 3 formulated as shown in Table 2 was added dropwise over 90 minutes. The temperature inside the reaction vessel was kept at 85°C during the dropwise addition. After the dropwise addition was completed, the mixture was aged at 85°C for 90 minutes.

[0062] Next, monomer mixture 4 formulated as shown in Table 2 was added dropwise over 90 minutes. The temperature inside the reaction vessel was kept at 85°C during the dropwise addition. After the dropwise addition was completed, the mixture was aged at 85°C for 90 minutes. It was then cooled to room temperature, and 25% aqueous ammonia was added to adjust the pH to 8.5, to obtain polymer emulsion E2.

[0063] [Table 2]

[0064] Comparative Example 1 Composition A + Emulsifier S4 for emulsion polymerization A polymer emulsion E3 was obtained in the same manner as in Example 1, except that emulsifier S4 for emulsion polymerization (manufactured by ADEKA CORPORATION, product name: ADEKA REASOAP (registered trademark) SR-10, abbreviation: emulsifier S4) was used instead of emulsifier S1.

[0065] Comparative Example 2 Composition B + Emulsifier for emulsion polymerization S4 A polymer emulsion E4 was obtained in the same manner as in Example 2, except that emulsifier S4 (manufactured by ADEKA CORPORATION, product name: ADEKA REASOAP (registered trademark) SR-10) was used instead of emulsifier S1.

[0066] Comparative Example 3 Composition A + Emulsifier S5 for emulsion polymerization A polymer emulsion E5 was obtained in the same manner as in Example 1, except that emulsifier S5 for emulsion polymerization (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: AQUALON (registered trademark) KH-10, abbreviation: emulsifier S5) was used instead of emulsifier S1.

[0067] Comparative Example 4 Composition B + Emulsifier for emulsion polymerization S5 A polymer emulsion E6 was obtained in the same manner as in Example 2, except that emulsifier S5 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon (registered trademark) KH-10) was used instead of emulsifier S1.

[0068] Comparative Example 5 Composition A + Emulsifier S2 for emulsion polymerization Polymer emulsion E7 was obtained in the same manner as in Example 1, except that emulsifier S2 (the compound obtained in Comparative Synthesis Example 1) was used instead of emulsifier S1.

[0069] Comparative Example 6 Composition B + Emulsifier S2 for emulsion polymerization Polymer emulsion E8 was obtained in the same manner as in Example 2, except that emulsifier S2 (the compound obtained in Comparative Synthesis Example 1) was used instead of emulsifier S1.

[0070] Comparative Example 7 Composition A + Emulsifier S3 for emulsion polymerization A polymer emulsion E9 was obtained in the same manner as in Example 1, except that emulsifier S3 (the compound obtained in Comparative Synthesis Example 2) was used instead of emulsifier S1.

[0071] Comparative Example 8 Composition B + Emulsifier for emulsion polymerization S3 A polymer emulsion E10 was obtained in the same manner as in Example 2, except that emulsifier S3 (the compound obtained in Comparative Synthesis Example 2) was used instead of emulsifier S1.

[0072] (Freeze-thaw stability evaluation) The polymer emulsions obtained in Examples 1 and 2 and Comparative Examples 1 to 8 were evaluated for freeze-thaw stability. Specifically, 100 g of each polymer emulsion was placed in a 100 ml semi-transparent resin container with a lid and sealed, and the polymer emulsion was left in a thermostatic chamber at -10°C for 16 hours and then at room temperature for 8 hours, after which the appearance of the polymer emulsion was observed. This cycle was repeated 5 times.

[0073] The evaluation criteria were as follows: if the sample did not freeze after five cycles, or if it was frozen but became liquid after being left to stand at room temperature for eight hours, it was marked as ◯; if the sample was frozen within five cycles and did not return to liquid after being left to stand at room temperature for eight hours, it was marked as ×. The results are summarized in Table 3.

[0074] [Table 3]

[0075] (Adhesion evaluation) The adhesion was evaluated for the polymer emulsions obtained in Example 1 and Comparative Examples 1, 3, 5, and 7. The specific evaluation method was as follows.

[0076] 100 parts by mass of the polymer emulsion obtained in Example 1 and Comparative Examples 1, 3, 5, and 7 were mixed with 5 parts by mass of a film-forming aid (a mixture of ethylene glycol monobutyl ether and Texanol in a mass ratio of 1:1), and each mixture was applied to a glass substrate in a film thickness of 75 μm. Then, the mixture was dried in a dryer at 110° C. for 3 minutes to obtain a test piece having a coating film of about 15 μm formed on the glass substrate. Using this test piece, evaluation was performed according to the following procedure, and the results are summarized in Table 4.

[0077] (1) Make 11 parallel cuts at 1 mm intervals that reach the glass substrate, then turn the substrate 90 degrees and make 11 more cuts in the same way; (2) Apply cellophane adhesive tape to the cut surface so that it adheres to the surface for about 50 mm, and rub the tape with an eraser to adhere it to the coating; (3) After 1 to 2 minutes of application, hold the edge of the tape perpendicular to the coating surface and pull it off.

[0078] Evaluation criteria: Out of 100 cut lattices, the number of lattices that were removed was: 0~4 pieces:○ 5 or more: ×

[0079] [Table 4]

[0080] The results shown in Tables 3 and 4 show that by using the freeze-thaw stability improver or adhesion improver of the present invention, extremely excellent freeze-thaw stability of the emulsion and adhesion between the polymer and the substrate can be achieved.

Claims

1. An adhesion improver between a polymer and a substrate, comprising a compound represented by the following general formula (1): 【Chemistry 1】 In the general formula (1), Q ＋ is a nitrogen-containing compound cation having a (meth)acryloyloxy group, A is a linear or branched alkylene group having 2 to 4 carbon atoms; m represents the average number of moles of AO added and is a number from 1 to 150; Y is a single bond or a linear or branched alkylene group having 1 to 5 carbon atoms; R １ is a hydrogen atom or a methyl group, R ２ is a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 25 carbon atoms, or a group represented by the following general formula (2): l is an integer from 1 to 3; 【Chemistry 2】 In the general formula (2), R ３ and R ４ are each independently a hydrogen atom or a methyl group, and * represents a connection point. Here, the adhesion is evaluated by the following method: (Method of evaluating adhesion) A mixture of 100 parts by mass of a polymer emulsion containing the polymer and 5 parts by mass of a film-forming aid (a 1:1 mixture of ethylene glycol monobutyl ether and Texanol by mass ratio) was applied to a glass substrate in a thickness of 75 μm, and then dried in a dryer at 110° C. for 3 minutes to obtain a test piece having a coating film of about 15 μm formed on the glass substrate. Using this test piece, evaluation was performed according to the following procedure, and it was determined that the smaller the number of peeled lattices, the better the adhesion: (1) Make 11 parallel cuts at 1 mm intervals that reach the glass substrate, then turn the substrate 90° and make 11 more cuts in the same manner; (2) Stick cellophane adhesive tape on the cut coating surface so that it adheres to the coating surface for about 50 mm, and rub the tape with an eraser to adhere it to the coating surface; (3) After 1 to 2 minutes of application, hold the edge of the tape perpendicular to the coating surface and pull it off.

2. Q ＋ The adhesion improver according to claim 1 , wherein 【Chemistry 3】 In the general formula (3), R ５ and R ６ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms; R ７ is a linear or branched alkylene group having 2 to 4 carbon atoms, X is an oxygen atom or NH, R ８ is a hydrogen atom or a methyl group.

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