Silicone-based surfactant

Abstract

To provide a silicone-based surfactant having excellent solubility in water, performance in lowering the surface tension of water and leveling properties.SOLUTION: There is provided a silicone-based surfactant which is a copolymer having 5 to 50 mass% of a structural unit (A) derived from a compound represented by a predetermined formula, 25 to 80 mass% of a structural unit (B) derived from a compound represented by a predetermined formula and 10 to 70 mass% of a structural unit (C) derived from a compound represented by a predetermined formula and a copolymer having 5 to 40 mass% of a structural unit (A) derived from a compound represented by a predetermined formula and 60 to 95 mass% of a structural unit (B) derived from a compound represented by a predetermined formula.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a silicone surfactant. [Background technology]

[0002] Silicone-based surfactants have excellent surface tension reducing ability and are used as leveling agents for paints and coating agents, etc. Silicone chain-containing copolymers are known as non-aqueous leveling agents (for example, Patent Document 1). On the other hand, polyether type surface modifiers that can be used in organic solvent-based or water-based systems are commercially available. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4936599 Summary of the Invention [Problem to be solved by the invention]

[0004] When the present inventors applied the above-mentioned polyether-type surface modifier to paint as a leveling agent, the above-mentioned polyether-type surface modifier had poor compatibility with water-based paints (i.e., solubility in water), and the coating film of the paint containing the above-mentioned polyether-type surface modifier was not smooth (i.e., poor leveling properties) in some cases. Furthermore, when the non-aqueous silicone chain-containing copolymer disclosed in Patent Document 1 was investigated, it was found that the copolymer was unable to sufficiently reduce the surface tension of water and sometimes had poor leveling properties.

[0005] Therefore, an object of the present invention is to provide a silicone surfactant that is excellent in solubility in water, ability to reduce the surface tension of water, and leveling property. [Means for solving the problem]

[0006] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0007] [1] 5 to 50% by mass of a structural unit (A) derived from a compound represented by formula (a) or formula (a') described below, 25 to 80% by mass of a structural unit (B) derived from a compound represented by formula (b) described below, and A silicone surfactant which is a copolymer having 10 to 70 mass % of a structural unit (C) derived from a compound represented by the formula (c) described below. [2] 5 to 40% by mass of a structural unit (A) derived from a compound represented by formula (a) or formula (a') described below, and A silicone surfactant which is a copolymer having 60 to 95 mass % of a structural unit (D) derived from a compound represented by the formula (d) described below. [3] In the above formulas (a) and (a'), the above Q 1 and Q above 2 are each independently a linear alkylene group.

[0008] In this specification, the silicone surfactant described in [1] above may be simply referred to as the "surfactant of the first embodiment," and the silicone surfactant described in [2] above may be simply referred to as the "surfactant of the second embodiment." In addition, in this specification, the silicone surfactants described in [1] and [2] above may be collectively referred to as the "surfactant of the present invention." In this specification, the compound represented by formula (a) may be simply referred to as "compound (a)" or "(a)". The same applies to the compounds represented by formula (a'), formulas (b) to (d), and formula (e) described below. Effect of the Invention

[0009] According to the present invention, it is possible to provide a silicone surfactant that is excellent in solubility in water, ability to reduce the surface tension of water, and leveling property. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The following description of the configuration may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "~" means a range including the numerical values ​​written before and after "~". In the present specification, each component may be used alone or in combination of two or more kinds. In this specification, when two or more types of a component are used in combination, the "content" of the component means the total content of those two or more types, unless otherwise specified. In the present specification, the method for producing each component is not particularly limited unless otherwise specified. For example, a conventionally known method may be used.

[0011] The surfactant of the present invention will now be described. The reason why the surfactant of the present invention having the above-mentioned structure can solve the problems of the present invention is not necessarily clear, but the present inventors speculate as follows. The mechanism by which the effects are obtained is not limited by the following speculation. In other words, even if the effects are obtained by a mechanism other than the following, it is included in the scope of the present invention. The surfactant of the present invention is a copolymer (surfactant of a first embodiment) having a structural unit (A) derived from a compound represented by formula (a) or formula (a'), a structural unit (B) derived from a compound represented by formula (b), and a structural unit (C) derived from a compound represented by formula (c), each within a predetermined range, and a copolymer (surfactant of a second embodiment) having a structural unit (A) derived from a compound represented by formula (a) or formula (a'), and a structural unit (B) derived from a compound represented by formula (d), each within a predetermined range. The surfactant of the present invention has a main chain skeleton which is poly(meth)acrylate, and the surfactant of the first embodiment is a copolymer having a structure in which a specific polysiloxane derived from structural unit (A), a polyoxyethylene chain derived from structural unit (B), and a polyoxypropylene chain derived from structural unit (C) are bonded to the main chain skeleton, while the surfactant of the second embodiment is a copolymer having a structure in which a specific polysiloxane derived from structural unit (A) and a polyoxyethyleneoxypropylene chain derived from structural unit (D) are bonded to the main chain skeleton, and it is believed that the surfactant of the present invention has excellent solubility in water, performance for reducing the surface tension of water, and leveling properties. Hereinafter, superiority in at least one of the solubility in water, the ability to reduce the surface tension of water, and the leveling property is also referred to as "superior effect of the present invention."

[0012] [Silicone-based surfactant of the first embodiment] The surfactant according to the first aspect of the present invention (surfactant according to the first aspect) will be described in detail below. The surfactant according to the first aspect of the present invention is 5 to 50% by mass of a structural unit (A) derived from a compound represented by formula (a) or formula (a') described below, 25 to 80% by mass of a structural unit (B) derived from a compound represented by formula (b) described below, and The silicone surfactant is a copolymer having 10 to 70 mass % of a structural unit (C) derived from a compound represented by the formula (c) described below. The surfactant according to the first aspect of the present invention contains at least a copolymer having the structural unit (A), the structural unit (B) and the structural unit (C).

[0013] [(a)] In the first embodiment of the surfactant, formula (a) is: [ka] The symbols in formula (a) have the following meanings. R 1 : Hydrogen atom or methyl group R2 : an alkyl group having 1 to 12 carbon atoms Q 1 : Divalent linking group n: an integer between 1 and 4

[0014] (R 1 ) R in formula (a) 1 is a hydrogen atom or a methyl group. (R 2 ) R in formula (a) 2 Examples of the (alkyl group having 1 to 12 carbon atoms) include a methyl group, an ethyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group.

[0015] (Q 1 ) Q in formula (a) 1 The divalent linking group is not particularly limited, and may be, for example, an alkylene group. Q 1 is preferably a linear alkylene group because the effects of the present invention are more excellent.

[0016] (n) In the formula (a), n is preferably an integer of 1 to 3, and more preferably an integer of 1 to 2, because the effects of the present invention are more excellent.

[0017] Examples of the compound represented by formula (a) include compounds represented by the following formula: CH2=C(-CH3)-COO-Q1-Si(CH3)2-O-[Si(CH3)2-O]2-Si(CH3)2R 2 Q1 in the above formula is the same as Q1 in formula (a). 2 is R in formula (a). 2 is the same as:

[0018] [(a')] In the first embodiment of the surfactant, formula (a') is: [ka] The symbols in formula (a') have the following meanings. R 3 : Hydrogen atom or methyl group Q 2 : Divalent linking group

[0019] (R 3 ) R in formula (a') 3 is a hydrogen atom or a methyl group.

[0020] (Q 2 ) Q in formula (a') 2 The divalent linking group is not particularly limited, and may be, for example, an alkylene group. Q 2 is preferably a linear alkylene group, and more preferably a linear alkylene group having 2 to 4 carbon atoms, because this provides better effects of the present invention.

[0021] The compound represented by formula (a') preferably includes a compound having the following structure, and more preferably includes a compound in which -C3H6- is linear, because the effects of the present invention are more excellent. [ka]

[0022] [(b)] In the surfactant of the first embodiment, formula (b) is: CH2=CR 4 -COO-(C2H4O)pR 5 (b) The symbols in formula (b) have the following meanings. R 4 : Hydrogen atom or methyl group R 5 : Hydrogen atom or an alkyl group having 1 to 12 carbon atoms p: an integer between 1 and 30

[0023] Examples of the compound (b) include R 4is a hydrogen atom or a methyl group, and R 5 is an alkyl group having 1 to 12 carbon atoms, and p is an integer of 1 to 30. R 4 is a hydrogen atom or a methyl group, and R 5 is a hydrogen atom, and p is an integer of 1 to 30. Compound (b) preferably contains compound (b1) and / or compound (b2), more preferably contains compound (b1), and further preferably contains compound (b1) and compound (b2), because the effects of the present invention are more excellent. When compound (b) contains compound (b1), it is preferable that p in formula (b) is an integer of 2 to 23, since the effects of the present invention are more excellent. When compound (b) contains compound (b2), it is preferable that p in formula (b) is an integer of 1 to 9 in compound (b2) because the effects of the present invention are more excellent. Examples of the compound (b2) include Compound (b2-1) in which p is an integer of 1 to 3; Compounds (b2-2) in which p is an integer of 4 to 9 are also included. When compound (b) contains compound (b2), compound (b2) preferably contains compound (b2-1) because the effects of the present invention (particularly the performance of reducing the surface tension of water) are more excellent.

[0024] [(c)] In the first embodiment of the surfactant, formula (c) is: CH2=CR 6 -COO-(C3H6O)qR 7 (c) The symbols in formula (c) have the following meanings. R 6 : Hydrogen atom or methyl group R 7 : Hydrogen atom or an alkyl group having 1 to 12 carbon atoms q: an integer between 1 and 30

[0025] (R6 ) R in formula (c) 6 is a hydrogen atom or a methyl group. (R 7 ) R in formula (c) 7 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. (q) In formula (c), q is preferably an integer of 5 to 15 because the effects of the present invention are more excellent.

[0026] The compound represented by formula (c) preferably includes a compound having the following structure, because the effect of the present invention is more excellent. CH2=C(-CH3)-COO-(C3H6O)qH (q in the above structure is 9).

[0027] Unit In the surfactant of the first embodiment, the structural unit (A) is derived from (a) or (a'). The structural unit (A) may have both structural units derived from (a) and (a'). The structural unit (A) preferably contains a structural unit derived from (a) because this provides better effects for the present invention (particularly the ability to reduce the surface tension of water).

[0028] [Proportion of structural unit (A)] In the surfactant of the first embodiment, the proportion of the structural unit (A) derived from the compound represented by formula (a) or formula (a') is independently 5 to 50 mass % in the copolymer contained in the surfactant of the first embodiment. When the structural unit (A) is derived from (a) and (a'), the total of the structural units derived from (a) and (a') may be 5 to 50 mass % in the copolymer. The proportion of the structural unit (A) derived from the compound represented by formula (a) or formula (a') is preferably 15 to 30 mass% and more preferably 18 to 23 mass% in the copolymer contained in the surfactant of the first aspect, each independently, for reasons of better effects of the present invention (particularly the performance in reducing the surface tension of water, and solubility in water).

[0029] [Block] In the surfactant of the first embodiment, the structural unit (B) is derived from (b).

[0030] [Proportion of structural unit (B)] In the surfactant of the first embodiment, the proportion of the structural unit (B) derived from the compound represented by formula (b) is 25 to 80 mass % in the copolymer contained in the surfactant of the first embodiment. When the structural unit (B) contains two or more structural units derived from (b), the total amount of the structural units derived from two or more types of (b) may be 25 to 80 mass % in the copolymer.

[0031] When compound (b) contains the above compound (b1), the proportion of the structural unit (B1) derived from (b1) is preferably 25 to 60 mass %, and more preferably 25 to 35 mass %, in the copolymer contained in the surfactant of the first aspect, because the effects of the present invention (particularly the performance of reducing the surface tension of water) are more excellent. When compound (b) contains the above compound (b1) and compound (b2), the proportion of the structural unit (B2) derived from (b2) is preferably 20 to 40 mass %, and more preferably 25 to 35 mass %, in the copolymer contained in the surfactant of the first embodiment, because the effects of the present invention (particularly the performance of reducing the surface tension of water) are more excellent.

[0032] Constituent Unit In the surfactant of the first embodiment, the structural unit (C) is derived from (c).

[0033] [Proportion of structural unit (C)] In the surfactant of the first embodiment, the proportion of the structural unit (C) derived from the compound represented by formula (c) is 10 to 70 mass % in the copolymer contained in the surfactant of the first embodiment. The proportion of the structural unit (C) is preferably independently 15 to 30 mass % in the copolymer contained in the surfactant of the first aspect, and more preferably 18 to 23 mass %, because this provides better effects of the present invention (particularly the ability to reduce the surface tension of water and solubility in water).

[0034] [Second embodiment of silicone surfactant] The surfactant according to the second aspect of the present invention (surfactant according to the second aspect) will be described in detail below. The surfactant according to the second aspect of the present invention comprises 5 to 40 mass % of a structural unit (A) derived from a compound represented by formula (a) or formula (a'), and The silicone surfactant is a copolymer having 60 to 95 mass % of a structural unit (D) derived from a compound represented by the formula (d) described below. The surfactant according to the second aspect of the present invention contains at least a copolymer having the structural unit (A) and the structural unit (D). In addition, a preferred embodiment of the surfactant according to the second aspect of the present invention does not contain a copolymer contained in the surfactant according to the first aspect of the present invention.

[0035] [a], [a'] The compound represented by formula (a) in the surfactant of the second embodiment is the same as the compound represented by formula (a) in the surfactant of the first embodiment. The compound represented by formula (a') in the surfactant of the second embodiment is the same as the compound represented by formula (a') in the surfactant of the first embodiment.

[0036] [d] In the second embodiment of the surfactant, formula (d) is: CH2=CR 8 -COO-(C2H4O)r(C3H6O)sR 9 (d) The symbols in formula (d) have the following meanings. R 8 : Hydrogen atom or methyl group R 9: a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a (meth)acryloyl group r, s: each independently an integer from 1 to 50

[0037] (R 8 ) R in formula (d) 8 is a hydrogen atom or a methyl group. (R 9 ) R in formula (d) 9 Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group. R in formula (d) 9 The (meth)acryloyl group refers to either an acryloyl group (CH2=CH-CO-) or a methacryloyl group (CH2=C(-CH3)-CO-). R 9 is preferably a hydrogen atom or a (meth)acryloyl group because the effects of the present invention are superior.

[0038] (r,s) In the formula (d), r and s each independently represent an integer of 1 to 50. In formula (d), r indicates the total amount of repeating units of (C2H4O). In formula (d), s refers to the total amount of repeating units of (C3H6O). The polymerization mode of the "-(C2H4O)r(C3H6O)s-" portion in formula (d) is not particularly limited, and examples thereof include random copolymerization, block copolymerization (e.g., diblock copolymerization, triblock copolymerization), and tapered copolymerization. When the sum of r and s (r+s) in formula (d) is from 11 to 60, the leveling property is more excellent. On the other hand, when the sum of r and s in formula (d) is from 3 to 10, the performance of lowering the surface tension of water is more excellent.

[0039] R in formula (d) is preferably selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 3 9 is a hydrogen atom and / or R 9is a (meth)acryloyl group, 9 It is more preferable that the compound includes a compound in which is a hydrogen atom. (d) is R in formula (d) 9 In the case where the compound contains a hydrogen atom, R 9 The content of the compound in which is a hydrogen atom can be 50 to 100 mass % of the total amount of (d).

[0040] (Synthesis of (d)) The method for producing the compound (d) is not particularly limited. For example, a conventionally known method can be used. Specifically, for example, 8 -COOH (R in the formula 8 is R in (d) 8 (same as above) and OH-(C2H4O)r(C3H6O)sR 10 (The r and s in the formula on the left are the same as those in (d). 10 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.) is subjected to a dehydration reaction in the presence of a catalyst such as an acid to produce compound (d). After the reaction, the reaction product may be purified. The compound (d) produced as described above may be a mixture containing two or more compounds represented by formula (d) (e.g., R 9 is a hydrogen atom and R 9 is a (meth)acryloyl group).

[0041] Unit In the surfactant of the second embodiment, the structural unit (A) is derived from (a) or (a'). The structural unit (A) may be derived from (a) and (a'). The structural unit (A) preferably contains a structural unit derived from (a) because this provides better effects for the present invention (particularly the ability to reduce the surface tension of water).

[0042] [Proportion of structural unit (A)] In the surfactant of the second embodiment, the proportion of the structural unit (A) derived from the compound represented by formula (a) or formula (a') is independently 5 to 40 mass% in the copolymer contained in the surfactant of the second embodiment. When the structural unit (A) is derived from (a) and (a'), the total of the structural units derived from (a) and (a') may be 5 to 40 mass% in the copolymer. The proportion of the structural unit (A) derived from the compound represented by formula (a) or formula (a') is preferably independently 15 to 30 mass % in the copolymer contained in the surfactant of the second aspect, because this provides better effects of the present invention (particularly the ability to reduce the surface tension of water, and solubility in water).

[0043] Unit In the surfactant of the second embodiment, the structural unit (D) is derived from (d).

[0044] [Proportion of constituent unit (D)] In the surfactant of the second embodiment, the proportion of the structural unit (D) derived from the compound represented by formula (d) is 60 to 95 mass % in the copolymer contained in the surfactant of the second embodiment. The proportion of the structural unit (D) is preferably independently 70 to 85 mass % in the copolymer contained in the surfactant of the second aspect, because this provides better effects of the present invention (particularly the ability to reduce the surface tension of water and solubility in water).

[0045] (Structural unit (E)) In the surfactants of the first and second embodiments, each copolymer may further have a structural unit (E) other than the above structural units (A), (B), (C) and (D). A compound represented by formula (e) The compound represented by formula (e) which can constitute the above-mentioned structural unit (E) is preferably a compound having copolymerizability with at least one of formulas (a) or (a'), (b), and (c), or with the compound represented by formula (d). Hereinafter, the compound represented by formula (e) is also referred to as "polymerizable compound (e)". The polymerizable compound (e) can be appropriately selected from various compounds depending on the purpose. The polymerizable compound (e) may be one type or two or more types. An example of the polymerizable compound (e) is a (meth)acrylic acid compound (e1). (Meth)acrylic acid compounds (e1) Examples of the (meth)acrylic acid-based compound (e1) include (meth)acrylates and (meth)acrylamides represented by the following formula (e-1). CH2=C(R e1 )-COX e1 -Q e1 -R e2 (e-1) In the formula, R e1 : a hydrogen atom or a methyl group, X e1 : -O- or -NR e3 - and Q e1 : a single bond or a divalent linking group, R e2 -H, -Si(OAk)3 (Ak is a linear or branched alkyl group having 1 to 3 carbon atoms), -CH3, -CH2CH2N(CH3)2, -CH2CH2N(C2H5)2, -(CH2) m H(m=2~24), -CH2CH(CH3)2, -CH2-C(CH3)2-OCO-Ph, -CH2Ph, -CH2CH2OPh, -(CH2CH2O) m Ph(m=2-45), -(CH2CH2O) m Ph-C n H 2n+1 (m = 2-45) (n = 1-24), -CH2N + (CH3)3Cl - , -SO3H. The above X e1 -NR as e3 -R in e3 Examples of the group include a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The polymerizable compound (e) does not include the compounds represented by the formulas (a), (b), (c), and (d). The proportion of the structural unit (E) can be 0 to 20 mass % in the copolymer contained in the surfactant of the first embodiment. The proportion of the structural unit (E) can be 0 to 20 mass % in the copolymer contained in the surfactant of the second embodiment.

[0046] (Manufacturing method) The method for producing the surfactant of the present invention (as mentioned above, the surfactants of the first and second aspects of the present invention are also collectively referred to as "surfactants of the present invention", the same applies below) is not particularly limited. For example, in a solvent such as methyl ethyl ketone, in the presence of a polymerization initiator such as dimethyl-2,2'-azobis(2-methylpropionate) and a chain transfer agent such as n-dodecyl mercaptan, compounds corresponding to the structural units (A) to (C) or the structural units (A) and (D), and the structural unit (E) which may be further included as necessary, are used in amounts corresponding to the proportions of each structural unit, and the above compounds are reacted under a nitrogen atmosphere at 60 to 80°C for 10 to 24 hours to obtain the surfactant of the present invention.

[0047] (Additives) The surfactant of the present invention may further contain, as necessary, for example, a solvent, a pH adjuster, a rust inhibitor, a dye, a dye stabilizer, a flame retardant, an antifoaming agent, and an antistatic agent within a range that does not impair the effects of the present invention. The surfactant of the present invention can be used by mixing with a solvent. The solvent is not particularly limited as long as it can dissolve or disperse the surfactant of the present invention. The solvent may contain water.

[0048] (Application) The surfactant of the present invention can be used by adding it to, for example, paints and coating agents. The paint is not particularly limited. For example, conventionally known paints can be mentioned. The paint to which the surfactant of the present invention is applied is preferably a water-based paint or an emulsion-based paint. The type of solid content contained in the paint is not particularly limited. The amount of the surfactant of the present invention used when applying the surfactant of the present invention to a paint is not particularly limited. The above circumstances are similar to those for coating agents. EXAMPLES

[0049] The present invention will be described in further detail below with reference to examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples. In the following, unless otherwise specified, the terms "parts" and "%" mean "parts by mass" and "% by mass".

[0050] [Surfactant manufacturing] The components shown in Table 1 below were charged into a pressure-resistant sealed container in the proportions (parts) shown in the same table, and after purging with nitrogen, the reaction was carried out at 70°C for 18 hours to obtain a solution (methyl ethyl ketone solution) containing each surfactant (predetermined copolymer) at a concentration of 41%. In Comparative Example 6, no surfactant was produced, and instead, KP-110 (manufactured by Shin-Etsu Chemical Co., Ltd., low molecular weight silicone leveling agent, structure shown below, CAS RN 27306-78-1) was used. Si(-CH3)3-O-Si(-CH3)RO-Si(-CH3)3 In the above formula, R is -(CH2CH2CH2)-O-(CH2CH2)-O-CH3.

[0051] [evaluation] The surfactants obtained as described above were subjected to the following evaluations, and the results are shown in Table 1. (Solubility in Water) Each surfactant was added to ion-exchanged water to prepare aqueous solutions with concentrations of each surfactant (prescribed copolymer; the same applies below) of 0.1% and 1%, and the aqueous solutions were visually observed. If each aqueous solution was transparent, it was marked with "O". If the solution obtained as described above was not transparent or the surfactant was not dissolved in the solution, it was marked with "X". In the present invention, when the result of the above observation for an aqueous solution containing a surfactant at a concentration of 0.1% was at least "good," the surfactant was evaluated as having excellent solubility in water. When the results of the above observations for the aqueous solutions containing a surfactant at a concentration of 0.1% and 1% were both "good," the surfactant was evaluated as having excellent solubility in water. On the other hand, when the results of the above observations for the aqueous solutions containing a surfactant at a concentration of 0.1% and 1% were both "X", the surfactant was evaluated as having poor solubility in water.

[0052] (surface tension) Each surfactant was added to ion-exchanged water to prepare aqueous solutions with concentrations of 0.1% and 1%. The static surface tension (mN / m) of each of the above aqueous solutions at 25° C. was measured by the Wilhelmy method (platinum plate) using a multi-function automatic surface tensiometer K100 (manufactured by KRUSS). In the present invention, the performance of reducing the surface tension of water was evaluated by measuring the static surface tension as described above for aqueous solutions containing 0.1% and 1% surfactant. In the present invention, when the static surface tension of aqueous solutions containing a surfactant at a concentration of 0.1% and 1% was less than 30 mN / m, the surfactant was evaluated as having excellent performance in reducing the surface tension of water. In addition, when the static surface tension of aqueous solutions with surfactant concentrations of 0.1% and 1% was less than 25 mN / m, the surfactant was evaluated as having better ability to reduce the surface tension of water. The smaller the static surface tension of an aqueous solution with a surfactant concentration of 0.1% or 1%, the better the performance of lowering the surface tension of water, and therefore it is preferable. On the other hand, when the static surface tension of an aqueous solution containing a 0.1% or 1% surfactant was 30 mN / m or more, the surfactant was evaluated as having poor performance in reducing the surface tension of water.

[0053] (Leveling ability) Each surfactant was added to ion-exchanged water to prepare an aqueous solution with a surfactant concentration of 1%. Each of the aqueous solutions (containing 1% surfactant) prepared as described above was added to an acrylic emulsion resin (Boncoat EF-5400, manufactured by DIC; solid content 55% by mass) in such an amount that the amount of surfactant (solid content) in the aqueous solution was 0.1% of the solid content of the acrylic emulsion, and the acrylic emulsion resin and the aqueous solution were mixed to obtain a mixture. In the obtained mixture, the ratio of the surfactant (solid content) was 0.052%, and the ratio of the acrylic emulsion resin (solid content) was 52.1%. The remainder after removing the surfactant (solid content) and the acrylic emulsion resin (solid content) from the above mixture was almost water (solvent). Each mixture obtained as described above was applied to a glass plate with a bar coater (wet film thickness 110 μm), and after drying, the smoothness of the film surface was visually observed and evaluated according to the following criteria. ⊚: The entire film was smooth. ○: Part of the film was uneven. ×: The film was uneven overall. In the present invention, when the smoothness was ◯ or ⊚, the leveling property was evaluated as excellent. On the other hand, when the smoothness was rated as x, the leveling property was evaluated as being poor.

[0054] [Table 1]

[0055] [Table 2]

[0056] Details of each component shown in Table 1 are as follows. (a) X-22-2404: One-terminated methacrylic modified silicone oil (structure below). Functional group equivalent: 420 g / mol (n=2 in formula (a)). Manufactured by Shin-Etsu Chemical Co., Ltd. CH2=C(-CH3)-COO-Q1-Si(CH3)2-O-[Si(CH3)2-O]2-Si(CH3)2R 2 In the above formula, Q1 is a linear alkylene group, and R 2 is an alkyl group having 1 to 12 carbon atoms.

[0057] (a') Silaplane TM-0701: Structure as shown below. Manufactured by JNC. [ka] In the above formula, -C3H6- is linear.

[0058] (comparison) X-22-174ASX: One-terminated methacrylic modified silicone oil. Functional group equivalent: 900 g / mol (n=8 in formula (a)). Manufactured by Shin-Etsu Chemical Co., Ltd.

[0059] (b) NK Ester AM-90G: Compound with the following structure. Manufactured by Shin-Nakamura Chemical Co., Ltd. [ka] Blenmar PE-200: Compound with the following structure (n=4-6 in the structure below). Manufactured by NOF Corp. [ka] Blenmer PE-90: Compound with the following structure (n=2 in the structure below). Manufactured by NOF Corp. [ka]

[0060] (c) Blenmar PP-500: CH2=C(-CH3)-COO-(C3H6O)qH (n in the above structure is 9). Manufactured by NOF Corp.

[0061] (d) (d1): A mixture containing a compound represented by the following formula (d1-1) and a compound represented by the following formula (d1-2). The content of (d1-1) in the mixture is 60 mass %, and the content of (d1-2) is 40 mass %. [ka] (d2): A compound having the following structure, where m is 4 and n is 3. [ka]

[0062] (comparison) n-Dodecyl methacrylate: Commercially available

[0063] Polymerization initiator: V-601, Fujifilm Wako Pure Chemical Industries, Ltd. Dimethyl-2,2′-azobis(2-methylpropionate) Chain transfer agent: n-dodecyl mercaptan (commercially available) Solvent: Methyl ethyl ketone

[0064] The results in Table 1 confirm that the surfactant of the present invention exhibits the desired effects. In a comparison between Examples 2, 4 to 8 (surfactants of the first embodiment) and Examples 9 to 11 (surfactants of the second embodiment), which have the same proportion of the structural unit (A) of 20 mass%, the surfactants of the first embodiment are superior to the surfactants of the second embodiment in solubility in water, performance in reducing the surface tension of water, and leveling properties, and exhibit an excellent balance of these properties.

[0065] Regarding the surfactants of the first aspect of the present invention (Examples 1 to 8), in a comparison between Example 4 and Example 2, (a) was superior to (a') in terms of the performance of reducing the surface tension of water. In comparison with Example 8, in which the proportion of the constitutional unit according to (a) is the same at 20% by mass, (b) is R 5 is a hydrogen atom, and R 5 In the case of a mixture with a compound in which R is an alkyl group having 1 to 12 carbon atoms, 5 The compound had a better ability to reduce the surface tension of water than a compound in which the compound is only an alkyl group having 1 to 12 carbon atoms. Comparing Examples 1, 2, 5, and 7 with Example 3, it was found that when the proportion of the structural unit (A) was 20 mass % or less, the solubility in water was superior.

[0066] On the other hand, Comparative Example 1 which did not have the structural units (A) and (C), Comparative Example 2 which did not have the structural unit (C) because the content of the structural unit (B) did not satisfy the specified range, Comparative Examples 3 and 4 which did not have the structural unit (C), Comparative Example 5 which did not have the structural unit (A) but instead had a structural unit derived from a compound in formula (a) where n exceeds 4, and Comparative Example 6 which did not contain a specified copolymer, were poor in at least any one of solubility in water, performance in reducing the surface tension of water, and leveling properties.

[0067] Regarding the surfactants of the second aspect of the present invention (Examples 9 to 11), in a comparison between Example 9 and Example 10, (a) was superior to (a') in terms of the performance of reducing the surface tension of water. Comparing Example 10 with Example 11, the leveling property was better when r+s in -(C2H4O)r(C3H6O)s- in (d) was 11 or more. Furthermore, in comparison between Example 10 and Example 11, the performance of reducing the surface tension of water was superior in (d) where r+s of -(C2H4O)r(C3H6O)s- was 10 or less.

[0068] On the other hand, Comparative Example 1 which did not have the structural units (A) and (D), Comparative Examples 2, 3 and 4 which did not have the structural unit (D), Comparative Example 5 which did not have the structural unit (A) but instead had a structural unit derived from a compound in formula (a) where n exceeds 4 and did not have the structural unit (D), and Comparative Example 6 which did not contain a specified copolymer, were poor in at least any of the solubility in water, the performance of reducing the surface tension of water, and the leveling properties.

Claims

1. 5 to 50% by mass of a structural unit (A) derived from a compound represented by the following formula (a) or formula (a'), 25 to 80% by mass of a structural unit (B) derived from a compound represented by the following formula (b), and A silicone-based surfactant which is a copolymer having 10 to 70 mass % of a structural unit (C) derived from a compound represented by the following formula (c): 【Chemistry 1】 The symbols in formula (a) have the following meanings. R １ : Hydrogen atom or methyl group R ２ : an alkyl group having 1 to 12 carbon atoms Q １ : a divalent linking group n: an integer from 1 to 4 【Chemistry 2】 The symbols in formula (a') have the following meanings. R ３ : Hydrogen atom or methyl group Q ２ : a divalent linking group CH ２ =CR ４ -COO-(C ２ H ４ O)p-R ５ (b) The symbols in formula (b) have the following meanings. R ４ : Hydrogen atom or methyl group R ５ : a hydrogen atom or an alkyl group having 1 to 12 carbon atoms p: an integer from 1 to 30 CH ２ =CR ６ -COO-(C ３ H ６ O)q-R ７ (c) The symbols in formula (c) have the following meanings. R ６ : Hydrogen atom or methyl group R ７ : a hydrogen atom or an alkyl group having 1 to 12 carbon atoms q: an integer from 1 to 30

2. 5 to 40% by mass of a structural unit (A) derived from a compound represented by the following formula (a) or formula (a'), and A silicone-based surfactant which is a copolymer having 60 to 95 mass % of a structural unit (D) derived from a compound represented by the following formula (d): 【Chemistry 3】 The symbols in formula (a) have the following meanings. R １ : Hydrogen atom or methyl group R ２ : an alkyl group having 1 to 12 carbon atoms Q １ : a divalent linking group n: an integer from 1 to 4 【Chemistry 4】 The symbols in formula (a') have the following meanings. R ３ : Hydrogen atom or methyl group Q ２ : a divalent linking group CH ２ =CR ８ -COO-(C ２ H ４ O)r(C ３ H ６ O)s-R ９ (d) The symbols in formula (d) have the following meanings. R ８ : Hydrogen atom or methyl group R ９ : a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a (meth)acryloyl group r, s: each independently an integer from 1 to 50

3. In the formulas (a) and (a′), the Q １ and the Q ２ The silicone surfactant according to claim 1 or 2, wherein each of the groups is independently a linear alkylene group.

Images