Method for producing a solution or dispersion containing a polysiloxane resin in water

Abstract

To provide a method for producing a solution or dispersion containing a polysiloxane resin with water as a medium, having excellent storage stability.SOLUTION: The present invention provides a method for producing a solution or dispersion containing a polysiloxane resin with water as a medium, the method including a condensation step for subjecting a silane compound to hydrolyzing, and dehydrating and condensing using neutral salt as a catalyst.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a solution or dispersion containing a polysiloxane resin in water, and to a solution or dispersion containing a polysiloxane resin in water obtained by the method. [Background technology]

[0002] Polysiloxanes, which are inorganic polysiloxanes grafted with acrylics, which have organic properties (hereinafter referred to as "polysiloxane-based resins"), have attracted industrial attention due to their interesting properties as inorganic-organic hybrid resins.

[0003] In particular, in the field of paints, water-based paints containing polysiloxane resins are becoming increasingly popular in the market due to their minimal adverse effects on the human body and the environment, and there is growing demand for them in a variety of applications.

[0004] As a method for producing a polysiloxane-based resin that can be used in such an aqueous system (aqueous medium), for example, Patent Document 1 discloses a method for producing a polysiloxane-based resin that includes a step of copolymerizing an organopolysiloxane compound having a radically polymerizable unsaturated group with a monomer that has a salt structure consisting of an acid and a base and also has a radically polymerizable unsaturated group. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-42279 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the technology of Patent Document 1 is an excellent technology, there is room for improvement in terms of the storage stability of polysiloxane resins in aqueous media.

[0007] Therefore, one aspect of the present invention aims to provide a method for producing a solution or dispersion containing a polysiloxane resin in water, which has excellent storage stability. [Means for solving the problem]

[0008] As a result of extensive research aimed at solving the above problems, the present inventors have discovered for the first time that by using a neutral salt as a catalyst in the hydrolysis and dehydration condensation of a silane compound in a production process for a polysiloxane resin, it is possible to obtain a solution or dispersion containing a polysiloxane resin in water and having excellent storage stability, and have completed the present invention.

[0009] Therefore, a method for producing a solution or dispersion containing a polysiloxane resin in water according to one embodiment of the present invention (hereinafter referred to as "the present production method") is a method for producing a solution or dispersion containing a polysiloxane resin in water, which includes a condensation step of carrying out hydrolysis and dehydration condensation of a silane compound using a neutral salt as a catalyst.

[0010] Furthermore, an aqueous solution or dispersion containing a polysiloxane-based resin according to one embodiment of the present invention (hereinafter referred to as "the solution or dispersion") is an aqueous solution or dispersion containing a polysiloxane-based resin, wherein the polysiloxane-based resin has a polymer containing, as a constituent unit, a constituent unit derived from a monomer having a radically polymerizable unsaturated group, and the condensation degree of the polysiloxane-based resin is 60 to 98%. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to obtain a solution or dispersion containing a polysiloxane resin in water and having excellent storage stability. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less."

[0013] 1. Overview of the Invention

[0003] Conventionally, the storage stability of polysiloxane resins in aqueous media has not been fully studied. In studying ways to improve this storage stability, the present inventors focused on the condensation degree of polysiloxane resins. Specifically, they thought that by using a synthesis method that uses a specific catalyst to set the condensation degree of the polysiloxane resin in an appropriate range when synthesizing the polysiloxane resin, the storage stability of the polysiloxane resin after acrylic grafting could be improved even in aqueous media.

[0014] As a result of extensive research conducted by the present inventors from the above viewpoints, they have succeeded in obtaining an aqueous solution or dispersion containing a polysiloxane resin with excellent storage stability by using a neutral salt as a catalyst when carrying out hydrolysis and dehydration condensation of a silane compound in a production process for a polysiloxane resin.

[0015] Generally, catalysts used in condensation include acid catalysts and base catalysts, and it is known that acid catalysts tend to lower the degree of condensation, while base catalysts tend to increase the degree of condensation. Here, the present inventors also obtained the following findings in the process of arriving at the above invention. In the case of acid catalysts, the number of OH groups in the polysiloxane resin increases, which means that the grafted acrylic does not sufficiently inhibit condensation, causing condensation to progress over time and resulting in gelation. As a result, the storage stability of the polysiloxane resin tends to deteriorate. When using a base catalyst, the number of OH groups in the polysiloxane resin decreases, causing excessive condensation (gelation) during synthesis. As a result, the synthesis of the polysiloxane resin may not proceed properly.

[0016] Based on the above-mentioned new findings, the present inventors presume that the use of a neutral salt catalyst has enabled the production of a polysiloxane resin with a well-balanced OH group content, making it possible to use the resin as an aqueous medium. However, the present invention is not limited to the above-mentioned mechanism.

[0017] The solution or dispersion obtained by this production method has excellent storage stability, and therefore this production method and this solution or dispersion are extremely useful as materials for paints, particularly water-based paints.

[0018] As described above, the solution or dispersion obtained by this production method can be used in an aqueous medium, and therefore has little adverse effect on the human body or the environment. Therefore, it can contribute to the achievement of the Sustainable Development Goals (SDGs), such as Goal 12 "Ensure sustainable consumption and production patterns." The configuration of the present invention is described in detail below.

[0019] 2. Method for producing a solution or dispersion containing a polysiloxane resin in water The present manufacturing method includes the following steps: - Condensation process in which a neutral salt is used as a catalyst to carry out hydrolysis and dehydration condensation of silane compounds.

[0020] (condensation process) The condensation step in this production method is a step in which hydrolysis and dehydration condensation of a silane compound are carried out using a neutral salt as a catalyst.

[0021] In one embodiment of the present invention, the condensation step in the present production method may comprise the following steps: a silane compound (A) having a radical polymerizable unsaturated group and a hydrolyzable silyl group; The following general formula (I) other than the above (A): R 1 n -Si-(OR 2 ) 4-n (I) (In the formula, R 1are each independently an alkyl group having 1 to 10 carbon atoms or an unsubstituted or substituted aryl group, and R 2 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 0 to 3, A step of hydrolyzing and dehydrating condensing a mixture containing the compound.

[0022] In the following, the "silane compound (A) having a radically polymerizable unsaturated group and a hydrolyzable silyl group" in the condensation step will be simply referred to as "silane compound (A)", and the "silane compound (A) other than the above (A)" will be referred to as "silane compound (A) having the following general formula (I): R 1 n -Si-(OR 2 ) 4-n The silane compound (B) represented by (I) will be simply referred to as the silane compound (B).

[0023] In the condensation step of this production method, silane compound (A) and silane compound (A) and / or silane compound (B) undergo hydrolysis and dehydration condensation to form a mixture containing a polysiloxane macromer and having a weight-average molecular weight within a specific range.

[0024] <Silane compound (A)> The silane compound (A) is a silane compound having a radically polymerizable unsaturated group and a hydrolyzable silyl group. In the condensation step, the silane compound (A) undergoes dehydration condensation with the silane compound (A) and / or the silane compound (B) to form a polysiloxane macromer. In the polymerization step described below, the radically polymerizable unsaturated group in the silane compound (A) undergoes radical polymerization with the radically polymerizable unsaturated group derived from the monomer (C) to form a graft chain derived from the monomer (C). In the condensation step, the inclusion of a certain amount of the silane compound (A) in the polysiloxane macromer has the advantage that the polymerization reaction in the radical polymerization step proceeds smoothly, allowing the target product to be obtained.

[0025] In one embodiment of the present invention, the silane compound (A) is represented by the following general formula (II): R 3 a R 4 b -Si-(OR 5 ) 4-a―b (II) (In the formula, R 3 is a substituted alkyl group or alkenyl group having 1 to 10 carbon atoms and having a radically polymerizable unsaturated group, or an aryl group having a radically polymerizable unsaturated group and optionally having other substituents, and R 4 are each independently an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group, and R 5 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, a is an integer of 1 to 3, b is an integer of 0 to 2, and a+b is an integer of 1 to 3.

[0026] In general formula (II), a is an integer of 1 to 3, b is an integer of 0 to 2, and a+b may be an integer of 1 to 3, but it is particularly preferred that a is 1 and b is 0 or 1.

[0027] R in general formula (II) 3 is a substituted alkyl group or alkenyl group having 1 to 10 carbon atoms and having a radically polymerizable unsaturated group, or an aryl group having a radically polymerizable unsaturated group and optionally having other substituents. The radically polymerizable unsaturated group is not particularly limited, but examples thereof include a (meth)acryloyl group and a (meth)acrylamide group.

[0028] R 3is a substituted alkyl group having a radical polymerizable unsaturated group, examples of the silane compound include (meth)acryloxymethyltrimethoxysilane, (meth)acryloxymethylmethyldimethoxysilane, (meth)acryloxymethyldimethylmethoxysilane, (meth)acryloxymethyltriethoxysilane, (meth)acryloxymethylmethyldiethoxysilane, (meth)acryloxymethyldimethylethoxysilane, 2-(meth)acryloxyethyltrimethoxysilane, 2-(meth)acryloxyethylmethyldimethoxysilane, 2- (Meth)acryloxyethyl dimethyl methoxy silane, 2-(meth)acryloxyethyl triethoxy silane, 2-(meth)acryloxyethyl methyl diethoxy silane, 2-(meth)acryloxyethyl dimethyl ethoxy silane, γ-(meth)acryloxypropyl trimethoxy silane, γ-(meth)acryloxypropyl methyl dimethoxy silane, γ-(meth)acryloxypropyl dimethyl methoxy silane, γ-(meth)acryloxypropyl triethoxy silane, γ-(meth)acryloxypropyl methyl diethoxy silane, γ- (Meth)acryloxypropyldimethylethoxysilane, 4-(meth)acryloxybutyltrimethoxysilane, 4-(meth)acryloxybutylmethyldimethoxysilane, 4-(meth)acryloxybutyldimethylmethoxysilane, 4-(meth)acryloxybutyltriethoxysilane, 4-(meth)acryloxybutylmethyldiethoxysilane, 4-(meth)acryloxybutyldimethylethoxysilane, 5-(meth)acryloxypentyltrimethoxysilane, 5-(meth)acryloxypentylmethyldimethoxysilane, 5-(meth)acryloxypentylmethyldimethoxysilane p) acryloxypentyldimethylmethoxysilane, 5-(meth)acryloxypentyltriethoxysilane, 5-(meth)acryloxypentylmethyldiethoxysilane, 5-(meth)acryloxypentyldimethylethoxysilane, 6-(meth)acryloxyhexyltrimethoxysilane, 6-(meth)acryloxyhexylmethyldimethoxysilane, 6-(meth)acryloxyhexyldimethylmethoxysilane, 6-(meth)acryloxyhexyltriethoxysilane, 6-(meth)acryloxyhexylmethyldiethoxysilane,6-(meth)acryloxyhexyldimethylethoxysilane, etc.

[0029] R 3 Examples of the silane compound in which is an alkenyl group include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, and vinyldimethylethoxysilane.

[0030] R 3 is an aryl group having a radically polymerizable unsaturated group and optionally having other substituents, examples of the silane compound include p-styryltrimethoxysilane, p-styrylmethyldimethoxysilane, p-styryldimethylmethoxysilane, p-styryltriethoxysilane, p-styrylmethyldiethoxysilane, and p-styryldimethylethoxysilane.

[0031] Among these, R 3 As the alkyl group, a (meth)acryloyl group-substituted alkyl group is preferred.

[0032] R in general formula (II) 4 are each independently an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group.

[0033] R in general formula (II) 4 Specific examples of the alkyl group in the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, an isoamyl group, a hexyl group, a cyclohexyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, and a 2-ethylhexyl group.

[0034] R in general formula (II) 4 Specific examples of the aryl group in include a phenyl group, a naphthyl group, and a benzyl group.

[0035] R in general formula (II) 4 When a is 1 and b is 1, it is preferably a methyl group.

[0036] R in general formula (II) 5 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group.

[0037] From the viewpoint of facilitating condensation of the silane compound (A) and the silane compound (B), R 5 The alkyl group preferably has 1 to 3 carbon atoms, and is most preferably a methyl group having 1 carbon atom.

[0038] In one embodiment of the present invention, the amount of silane compound (A) is, for example, 1% by weight or more, preferably 2% by weight or more, based on 100% by weight of the total amount of the polysiloxane resin. When the amount of silane compound (A) is 1% by weight or more, based on 100% by weight of the total amount of the polysiloxane resin, sufficient graft polymerization with monomer (C) can be achieved directly or indirectly, resulting in a polysiloxane resin that can be stably dispersed or dissolved (water-based) in an aqueous medium. The upper limit of the amount of silane compound (A) is not particularly limited as long as the effects of the present invention are achieved, but is, for example, 10% by weight or less, preferably 8% by weight or less. The present invention is particularly effective when the amount of silane compound (A) is larger (the proportion of silane compound (A) in the polysiloxane resin is higher).

[0039] <Silane Compound (B)> The silane compound (B) is a silane compound represented by the general formula (I): R 1 n -Si-(OR 2 ) 4-n (I) (In the formula, R 1are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group, and R 2 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 0 to 3. In the condensation step, the silane compound (B) undergoes dehydration condensation with the silane compound (A) and / or the silane compound (B) to form a polysiloxane macromer. The silane compound (B) is a main component constituting the polysiloxane chain, which is the main chain.

[0040] R in general formula (I) 1 Specific examples of the alkyl group in the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, an isoamyl group, a hexyl group, a cyclohexyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, and a 2-ethylhexyl group.

[0041] R in general formula (I) 1 Specific examples of the aryl group in include a phenyl group, a naphthyl group, and a benzyl group.

[0042] R in general formula (I) 2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group.

[0043] Specific compounds represented by general formula (II) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltriisopropoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltriisopropoxysilane, octyltrimethoxysilane, and octyltriethoxysilane. , octyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, trimethylmonomethoxysilane, triphenylmonomethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like.

[0044] In general formula (I), n may be an integer of 0 to 3, but trialkoxysilane compounds in which n is 1 are particularly preferred. When n is 1, there are three crosslinkable hydrolyzable silyl groups, making it possible to form a polymer with a network structure. Specific examples of compounds in which n is 1 are suitable from the standpoint of availability, such as methyltrimethoxysilane and phenyltrimethoxysilane.

[0045] From the viewpoint of facilitating condensation of the silane compound (B) with the silane compound (A), R 2 The alkyl group preferably has 1 to 3 carbon atoms, and most preferably 1 carbon atom.

[0046] In one embodiment of the present invention, the amount of silane compound (B) is, for example, 10% by weight or more, preferably 20% by weight or more, and more preferably 40% by weight or more, based on 100% by weight of the total amount of the polysiloxane resin. When the amount of silane compound (B) is 10% by weight or more, based on 100% by weight of the total amount of the polysiloxane resin, the polysiloxane resin exhibits excellent weather resistance, toughness, tackiness, and other properties. The upper limit of the amount of silane compound (B) is not particularly limited as long as the effects of the present invention are exhibited, but is, for example, 90% by weight or less. The greater the amount of silane compound (B) (the higher the proportion of silane compound (B) in the polysiloxane resin), the more effective the present invention becomes.

[0047] <Neutral salt> In the condensation step of this production method, a neutral salt is used as a catalyst. The use of a neutral salt as a catalyst makes it possible to obtain a polysiloxane macromer with an appropriate degree of condensation, and as a result, it is possible to obtain an aqueous solution or dispersion containing a polysiloxane resin with excellent storage stability.

[0048] Furthermore, the use of a neutral salt as a catalyst in the condensation step of this production method has the following advantages. Polysiloxane resins can be obtained without deactivating the organic substituents before, after, or during storage after hydrolysis and dehydration condensation. The neutral salt catalyst itself does not corrode the manufacturing or storage containers, so it can be used without being restricted by the materials of the manufacturing or storage equipment. - It is possible to omit the complicated steps of removing the acid or base and neutralizing the acid or base, which are required when using an acid or base catalyst.

[0049] As used herein, the term "neutral salt" refers to a positive salt composed of an acid and a base. There are no particular limitations on the neutral salt, but salts composed of a combination of a cation selected from the group consisting of Group 1 element ions, Group 2 element ions, tetraalkylammonium ions, and guanidium (guanidinium) ions, and an anion selected from the group consisting of Group 17 element ions excluding fluoride ions, sulfate ions, nitrate ions, and perchlorate ions are preferred.

[0050] The neutral salt is not particularly limited, but examples thereof include lithium chloride, sodium chloride, potassium chloride, rubidium chloride, cesium chloride, francium chloride, beryllium chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, radium chloride, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrapentylammonium chloride, tetrahexylammonium chloride, and guanidium chloride; lithium bromide, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, francium bromide, beryllium bromide, magnesium bromide, calcium bromide, strontium bromide, barium bromide, radium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide, and guanidium bromide. Lithium iodide, sodium iodide, potassium iodide, rubidium iodide, cesium iodide, francium iodide, beryllium iodide, magnesium iodide, calcium iodide, strontium iodide, barium iodide, radium iodide, tetramethylammonium iodide, tetraethylammonium iodide, tetrapropylammonium iodide, tetrabutylammonium iodide, tetrapentylammonium iodide, tetrahexylammonium iodide, guanidium iodide; Lithium sulfate, sodium sulfate, potassium sulfate, rubidium sulfate, cesium sulfate, francium sulfate, beryllium sulfate, magnesium sulfate, calcium sulfate, strontium sulfate, barium sulfate, radium sulfate, tetramethylammonium sulfate, tetraethylammonium sulfate, tetrapropylammonium sulfate, tetrabutylammonium sulfate, tetrapentylammonium sulfate, tetrahexylammonium sulfate, guanidium sulfate;Examples of neutral salts include lithium nitrate, sodium nitrate, potassium nitrate, rubidium nitrate, cesium nitrate, francium nitrate, beryllium nitrate, magnesium nitrate, calcium nitrate, strontium nitrate, barium nitrate, radium nitrate, tetramethylammonium nitrate, tetraethylammonium nitrate, tetrapropylammonium nitrate, tetrabutylammonium nitrate, tetrapentylammonium nitrate, tetrahexylammonium nitrate, and guanidium nitrate; lithium perchlorate, sodium perchlorate, potassium perchlorate, rubidium perchlorate, cesium perchlorate, francium perchlorate, beryllium perchlorate, magnesium perchlorate, calcium perchlorate, strontium perchlorate, barium perchlorate, radium perchlorate, tetramethylammonium perchlorate, tetraethylammonium perchlorate, tetrapropylammonium perchlorate, tetrabutylammonium perchlorate, tetrapentylammonium perchlorate, tetrahexylammonium perchlorate, and guanidium perchlorate. These neutral salts can be used alone or in combination of two or more.

[0051] Among these neutral salts, from the viewpoint of use as a catalyst, the anion is more preferably a Group 17 element ion because of its high nucleophilicity, and chloride ion, bromide ion, and iodide ion are even more preferred.

[0052] Furthermore, in consideration of availability and safety during handling, the following neutral salts are particularly preferred: lithium chloride, sodium chloride, potassium chloride, rubidium chloride, cesium chloride, magnesium chloride, calcium chloride, strontium chloride, lithium bromide, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, magnesium bromide, calcium bromide, strontium bromide, lithium iodide, sodium iodide, potassium iodide, rubidium iodide, cesium iodide, magnesium iodide, calcium iodide, strontium iodide, tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium iodide.

[0053] The amount of the neutral salt is preferably 0.1 ppm to 50,000 ppm, more preferably 1 ppm to 10,000 ppm, particularly preferably 5 ppm to 1,000 ppm, and most preferably 10 ppm to 500 ppm, relative to the silane compound (A) and the silane compound (B). When the amount of the neutral salt is 0.1 ppm or more, the neutral salt functions appropriately as a catalyst. When the amount of the neutral salt is 50,000 ppm or less, the effects of suppressing the rapid progress of the reaction and suppressing a decrease in water resistance due to residual salt are achieved.

[0054] The condensation step in this production method may further include water (also referred to as "condensation water").

[0055] The amount of condensation water in the condensation step is preferably 0.3 to 1.8 equivalents, more preferably 0.35 to 1.7 equivalents, even more preferably 0.4 to 1.6 equivalents, and particularly preferably 0.5 to 1.5 equivalents, relative to the hydrolyzable groups possessed by the silane compound (A) and the silane compound (B). When the amount of condensation water is 0.3 to 1.8 equivalents, the hydrolysis and dehydration condensation of the silane compound in the condensation step can be controlled, and the amount of OH groups (degree of condensation) of the polysiloxane macromer can be adjusted. When the amount of condensation water is less than 0.3 equivalents, the degree of condensation decreases, and condensation may progress over time, resulting in gelation. When the amount of condensation water exceeds 1.8 equivalents, the degree of condensation increases, leading to gelation during synthesis, which may hinder proper synthesis of the polysiloxane resin.

[0056] The mixture used in the condensation step of this production method may contain a diluent solvent in addition to the silane compound (A) and silane compound (B), a neutral salt, and water. Because the silane compound (A) and silane compound (B) are hydrophobic and water is used during the reaction, the diluent solvent is preferably water-soluble. While there is no limit to the amount of diluent solvent, an excessive amount reduces the concentration of the resulting polysiloxane, which is undesirable from the standpoint of production costs. Specific examples of dilution solvents include methanol, ethanol, 2-propanol, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, ethylene glycol diethyl ether, etc. Among these, methanol, ethanol, and 2-propanol are particularly preferred, considering the possibility of volatilization after production of the polysiloxane resin by the present production method or during coating film formation.

[0057] (Polymerization process) In one embodiment of the present invention, the production method may further include the following step after the condensation step: A polymerization step in which a monomer (C) having a radically polymerizable unsaturated group is added to carry out radical polymerization.

[0058] In the following, the "monomer (C) having a radically polymerizable unsaturated group" in the polymerization step will be simply referred to as "monomer (C)".

[0059] <Monomer (C)> The monomer (C) has a radically polymerizable unsaturated group but does not have a hydrolyzable silyl group. In the polymerization step, the radically polymerizable unsaturated group in the monomer (C) undergoes radical polymerization with the radically polymerizable unsaturated group derived from the silane compound (A), forming a graft chain derived from the monomer (C) on the polysiloxane main chain.

[0060] The radically polymerizable unsaturated group in the monomer (C) is not particularly limited as long as it can contribute to radical polymerization with the silane compound (A), etc. Examples of the radically polymerizable unsaturated group in the monomer (C) include a (meth)acryloyl group, a (meth)acrylamide group, and a vinyl group.

[0061] The monomer (C) is not particularly limited as long as it is a monomer having a radically polymerizable unsaturated group and not having a hydrolyzable silyl group, and examples thereof include (meth)acrylic acid alkyl esters and monomers other than (meth)acrylic acid alkyl esters as shown below.

[0062] <(Meth)acrylic acid alkyl ester> In one embodiment of the present invention, the (meth)acrylic acid alkyl ester is a (meth)acrylic acid ester having an alkyl group having 1 to 18 carbon atoms, and may be a (meth)alkyl monomer that does not contain functional groups such as a hydroxyl group or an epoxy group. In one embodiment of the present invention, the alkyl group in the (meth)acrylic acid alkyl ester may be linear or branched, or may be a cyclic cycloalkyl group. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)methacrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, and isobornyl (meth)acrylate.

[0063] <Monomers other than (meth)acrylic acid alkyl esters> Examples of monomers other than (meth)acrylic acid alkyl esters include nitrile group-containing radically polymerizable monomers such as (meth)acrylonitrile; epoxy group-containing radically polymerizable monomers such as glycidyl (meth)acrylate; hydrophilic radically polymerizable monomers such as 2-hydroxypropyl (meth)acrylate; 2-hydroxypropyl (meth)acrylate; 2-sulfoethyl methacrylate sodium, 2-sulfoethyl methacrylate ammonium, and radically polymerizable monomers having a polyoxyalkylene chain; monomers having two or more polymerizable unsaturated bonds such as polyethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, and allyl (meth)acrylate; and fluorine-containing radically polymerizable monomers such as trifluoro(meth)acrylate, pentafluoro(meth)acrylate, perfluorocyclohexyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, and β-(perfluorooctyl)ethyl (meth)acrylate.

[0064] In one embodiment of the present invention, the amount of monomer (C) is, for example, 10% by weight or more, preferably 15% by weight or more, and more preferably 20% by weight or more, based on 100% by weight of the total amount of polysiloxane resin. When the amount of monomer (C) is 10% by weight or more, based on 100% by weight of the total amount of polysiloxane resin, a cured film that is less likely to crack can be obtained. Furthermore, the upper limit of the amount of monomer (C) is not particularly limited as long as the effects of the present invention are achieved, but is, for example, 80% by weight or less, preferably 60% by weight or less, and more preferably 50% by weight or less.

[0065] In one embodiment of the present invention, the monomer (C) preferably contains a hydrophilic radically polymerizable monomer, and more preferably contains a monomer having a salt structure consisting of an acid and a base and having a radically polymerizable unsaturated group (hereinafter, sometimes referred to as "monomer (C')"). By containing the monomer (C'), the polysiloxane resin can be easily dissolved or dispersed in water.

[0066] The monomer (C') is not particularly limited as long as it is a monomer having a salt structure consisting of an acid and a base and having a radically polymerizable unsaturated group, and examples thereof include sodium sulfoethyl methacrylate, sodium acrylamido-t-butylsulfonate, sodium 2-(methacryloyloxy)ethanesulfonate, sodium 2-(methacryloyloxy)polyalkyleneoxidesulfonate, sodium acrylamido-t-butylsulfonate, potassium 2-(methacryloyloxy)ethanesulfonate, potassium 2-(methacryloyloxy)polyalkyleneoxidesulfonate, potassium acrylamido-t-butylsulfonate, 2-(methacryloyloxy)ethanesulfonate, Examples of the acrylate acrylate include calcium acrylate, calcium 2-(methacryloyloxy)polyalkylene oxide sulfonate, calcium acrylamido-t-butyl sulfonate, ammonium sulfoethyl methacrylate, ammonium acrylamido-t-butyl sulfonate, ammonium 2-(methacryloyloxy)ethanesulfonate, ammonium 2-(methacryloyloxy)polyalkylene oxide sulfonate, ammonium acrylamido-t-butyl sulfonate, sodium acrylate, potassium acrylate, calcium acrylate, ammonium acrylate, sodium methacrylate, potassium methacrylate, calcium methacrylate, and ammonium methacrylate.

[0067] Monomer (C') can be obtained as a commercially available product, such as "Antox MS-2N-D" manufactured by Nippon Nyukazai Co., Ltd., "ATBS-Na" manufactured by Toagosei Co., Ltd., "Eleminol RS-3000" manufactured by Sanyo Chemical Industries, Ltd., and "Sodium Acrylate" and "Potassium Acrylate" manufactured by Asada Chemical Industry Co., Ltd.

[0068] In one embodiment of the present invention, the amount of monomer (C') is, for example, 1% by weight or more, preferably 5% by weight or more, based on 100% by weight of the total amount of the polysiloxane resin. When the content of monomer (C') is within the above range, the effect of uniformly dispersing or solubilizing the monomer (C') in water is achieved. The upper limit of the amount of monomer (C') is not particularly limited as long as the effects of the present invention are achieved, but is, for example, 30% by weight or less, preferably 20% by weight or less.

[0069] <Radical polymerization initiator> In the polymerization step of the present production method, a radical polymerization initiator is added in addition to the monomer (C).

[0070] The radical polymerization initiator is not particularly limited as long as it is a substance capable of initiating a radical polymerization reaction between the radically polymerizable unsaturated group derived from the silane compound (A) and the monomer (C).

[0071] In one embodiment of the present invention, examples of the radical polymerization initiator include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, and diisopropyl peroxycarbonate.

[0072] In one embodiment of the present invention, the amount of the radical polymerization initiator is, for example, 0.01 to 10 wt %, preferably 0.05 to 7 wt %, and more preferably 0.1 to 5 wt %, relative to the total amount (100 wt %) of the polysiloxane resin. When the amount of the radical polymerization initiator is 0.01 wt % or more, polymerization proceeds appropriately. Furthermore, when the amount of the radical polymerization initiator is 10 wt % or less, a polymer with an appropriate molecular weight can be obtained.

[0073] In the polymerization step of the present production method, in addition to the monomer (C) and the radical polymerization initiator, any additives may be added within the range in which the effects of the present invention are exhibited. Such additives can be appropriately selected by those skilled in the art.

[0074] [3. Solution or Dispersion] The present solution or dispersion is a solution or dispersion in water containing a polysiloxane resin, the polysiloxane resin having a polymer containing, as a constituent unit, a constituent unit derived from a monomer having a radically polymerizable unsaturated group, and the polysiloxane resin having a condensation degree of 60 to 98%. The present solution or dispersion is useful because it has excellent storage stability in a solution in water.

[0075] As used herein, "aqueous solution" refers to a liquid that is transparent in appearance when the resin solids concentration is 20% and the proportion of water in the total medium is 90% by weight or more, more specifically, a liquid that has a haze value of 20.0 or less at 1 atmosphere and 25°C. Furthermore, as used herein, "aqueous dispersion" refers to a liquid that is cloudy in appearance when the resin solids concentration is 20% and the proportion of water in the total medium is 90% by weight or more, more specifically, a liquid that has a haze value of more than 20.0 at 1 atmosphere and 25°C. The haze value is measured using a COH400 (manufactured by Nippon Denshoku Industries Co., Ltd.) as the standard liquid.

[0076] In the present solution or dispersion, the monomer having a radically polymerizable unsaturated group is not particularly limited, but it is intended to be, for example, the above-mentioned "monomer (C)."

[0077] The condensation degree of the polysiloxane resin in this solution or dispersion is 60 to 98%, more preferably 65 to 97%, even more preferably 70 to 96%, and particularly preferably 75 to 95%. When the condensation degree of the polysiloxane resin is 60 to 98%, the storage stability in an aqueous medium is excellent. The condensation degree of the polysiloxane resin is calculated by the method described in the examples.

[0078] [4. Water-based paint] In one embodiment of the present invention, an aqueous paint (hereinafter referred to as "the present aqueous paint") containing the present solution or dispersion is provided. Because the present aqueous paint contains the above-mentioned present aqueous solution or present dispersion, it has excellent storage stability in a solution using water as a medium and is useful. Furthermore, the coating film obtained from the present aqueous paint has excellent weather resistance.

[0079] The aqueous coating material may contain additives commonly used in the art, as long as they achieve the effects of the present invention. Examples of such additives include pigments, fillers, plasticizers, film-forming aids, wetting / dispersing agents, thickeners, antifoaming agents, preservatives, antioxidants, antisettling agents, leveling agents, UV absorbers, antistatic agents, antifreeze agents, antibacterial agents, antifungal agents, tackifiers, and rust inhibitors. The coating material may contain one or more additives. The amount of these additives can be determined appropriately by those skilled in the art depending on the intended use.

[0080] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0081] That is, one aspect of the present invention includes the following. <1> A method for producing a solution or dispersion containing a polysiloxane resin in water, the method comprising a condensation step of carrying out hydrolysis and dehydration condensation of a silane compound using a neutral salt as a catalyst. <2> The condensation step a silane compound (A) having a radical polymerizable unsaturated group and a hydrolyzable silyl group; The following general formula (I) other than the above (A): R 1 n -Si-(OR 2 ) 4-n (I) (In the formula, R 1 are each independently an alkyl group having 1 to 10 carbon atoms or an unsubstituted or substituted aryl group, and R2 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 0 to 3, The method comprises the steps of hydrolyzing and dehydrating a mixture comprising: <1> The manufacturing method described in <3> a polymerization step of adding a monomer (C) having a radically polymerizable unsaturated group and carrying out radical polymerization after the condensation step, <1> or <2> The manufacturing method described in <4> the monomer (C) having a radical polymerizable unsaturated group has a salt structure consisting of an acid and a base and includes a monomer (C') having a radical polymerizable unsaturated group; <3> The manufacturing method described in <5> The neutral salt is a cation selected from the group consisting of Group 1 element ions, Group 2 element ions, tetraalkylammonium ions, and guanidinium ions; an anion selected from the group consisting of a Group 17 element ion excluding fluoride ion, a sulfate ion, a nitrate ion, and a perchlorate ion; A salt consisting of a combination of <1> ~ <4> 1. The manufacturing method according to any one of the preceding claims. <6> the amount of condensation water in the condensation step is 0.3 to 1.8 equivalents relative to the hydrolyzable groups possessed by (A) and (B); <1> ~ <5> 1. The manufacturing method according to any one of the preceding claims. <7> A solution or dispersion containing a polysiloxane resin in water, the polysiloxane-based resin has, as a structural unit, a polymer including a structural unit derived from a monomer having a radically polymerizable unsaturated group, A solution or dispersion containing a polysiloxane resin in water, wherein the polysiloxane resin has a degree of condensation of 60 to 95%. <8> <7> 1. An aqueous coating material comprising a solution or dispersion in water containing the polysiloxane resin according to claim 1. [Example]

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. It is not something that is done.

[0083] 〔material〕 The following materials were used in the examples and comparative examples.

[0084] (Silane compound (A)) γ-Methacryloxypropyltrimethoxysilane (3-(trimethoxysilyl)propyl methacrylate, abbreviated as "TSMA"): "A-174" manufactured by Momentive Performance Materials Japan, LLC (Silane Compound (B)) Methyltrimethoxysilane (abbreviated as "M-TMS"): "Z-6033" manufactured by Dow Toray Industries, Inc. Phenyltrimethoxysilane (abbreviated as "Ph-TMS"): "Z-6124" manufactured by Dow Toray Industries, Inc. (Monomer (C)) Methyl methacrylate (abbreviated as "MMA"): manufactured by Mitsubishi Gas Chemical Company, Inc. Butyl acrylate (abbreviated as "BA"): manufactured by Nippon Shokubai Co., Ltd. Acrylamide tertiary butyl sulfonate sodium: "ATBS" manufactured by Toagosei Co., Ltd. (Dehydration condensation catalyst) Lithium chloride (abbreviated as "LiCl"): Kanto Chemical Co., Ltd., neutral salt Magnesium chloride (abbreviated as "MgCl"): Kanto Chemical Co., Ltd., neutral salt Tetrabutylammonium bromide (abbreviated as "TBAB"): Tokyo Chemical Industry Co., Ltd., neutral salt Dibutyl phosphate (DBP): manufactured by Johoku Chemical Industry Co., Ltd., acid catalyst Diazabicycloundecene (abbreviated as "DBU"): manufactured by Tokyo Chemical Industry Co., Ltd., base catalyst (initiator) 2,2'-Azobis(2,4-dimethylvaleronitrile): "V-65" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (others) pure water [Measurement and evaluation methods] Measurements and evaluations in the examples and comparative examples were carried out by the following methods.

[0085] (synthesis) Polysiloxane resins were produced by the methods of Examples and Comparative Examples. If no gelation occurred during synthesis, the resin was evaluated as "Good", and if gelation occurred, the resin was evaluated as "Poor".

[0086] (Degree of condensation) The degree of condensation (the ratio of the number of condensed functional groups to the number of condensable functional groups) was defined by the following formula (1).

[0087]

number

[0088] where the values ​​of T0, T1, T2, and T3 are 29 These correspond to the integral values ​​of the peaks derived from the T0, T1, T2, and T3 isomers detected by Si-NMR measurement. The T0, T1, T2, and T3 are silane compounds in which three hydrolyzable groups are directly bonded to the Si atom, and are defined as follows when hydrolysis and dehydration condensation reactions proceed: T0 body: Si atom not bonded to other hydrolyzable silane compounds T1 body: Si atom bonded to one hydrolyzable silane compound via oxygen T2 body: Si atom bonded to two hydrolyzable silane compounds via oxygen T3: A Si atom bonded to three hydrolyzable silane compounds via oxygen. In addition, 29 The Si-NMR measurement is carried out using an NMR manufactured by BRUKER.

[0089] (Storage stability) A resin-containing aqueous solution adjusted to a solids concentration of 40% was sealed in a glass bottle and left to stand in a hot air dryer heated to 50°C. After storage at 50°C for two weeks and one month, cases where no gelation occurred were evaluated as "Good", and cases where gelation occurred were evaluated as "Poor".

[0090] Example 1 (Synthesis of Polysiloxane Macromer) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube, and a dropping funnel, and into which nitrogen gas had been introduced, was charged with the types and amounts of silane compound (A) and silane compound (B) shown in Table 1, and condensation water and a dehydration condensation catalyst were added with stirring. The mixture was allowed to react at a reaction temperature of 65°C for 3 hours with stirring to obtain a mixture.

[0091] (Synthesis of polysiloxane resin) Next, a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube, and dropping funnel, and introduced with nitrogen gas, was charged with the solvent components listed in Table 1, and the temperature was raised to 75°C. Then, a mixed solution of the obtained polysiloxane macromer with the monomer (C) and initiator listed in Table 1 was added dropwise at a constant rate from the dropping funnel over a period of 5 hours. After stirring for 2 hours at 75°C, the mixture was degassed using a rotary evaporator until the nonvolatile content reached 90% or more, and then diluted with water to a nonvolatile content of 40%. The mixture was cooled to room temperature, yielding an aqueous solution containing a polysiloxane resin. The unit of amount for each component in Table 1 is "g."

[0092] Example 2 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the type of dehydration condensation catalyst was changed as shown in Table 1.

[0093] Example 3 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the type of dehydration condensation catalyst was changed as shown in Table 1.

[0094] Example 4 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the amounts of the silane compounds (A) and (B) and the amount of pure water were changed as shown in Table 1.

[0095] Example 5 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the amounts of the silane compounds (A) and (B) and the amount of pure water were changed as shown in Table 1.

[0096] Comparative Example 1 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the type of dehydration condensation catalyst was changed as shown in Table 1.

[0097] Comparative Example 2 An aqueous solution containing a polysiloxane resin was obtained in the same manner as in Example 1, except that the amounts of silane compounds (A) and (B), the amount of pure water, and the type of dehydration condensation catalyst were changed as shown in Table 1.

[0098] Comparative Example 3 Synthesis was attempted in the same manner as in Example 1, except that the type of dehydration condensation catalyst was changed as shown in Table 1. However, gelation occurred during the synthesis of the polysiloxane macromer, and an aqueous solution containing a polysiloxane resin was not synthesized.

[0099] The results of Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1.

[0100] [Table 1]

[0101] 〔result〕 From Table 1, it is clear that in Examples 1 to 5, aqueous solutions containing polysiloxane resins with excellent storage stability (solutions or dispersions containing polysiloxane resins with excellent storage stability in water as a medium) could be produced. [Industrial Applicability]

[0102] According to the present invention, a solution or dispersion containing a polysiloxane resin in water and having excellent storage stability can be obtained, and therefore the solution or dispersion can be suitably used in various coating agent fields.

Claims

1. A method for producing a solution or dispersion containing a polysiloxane resin in water, the method comprising the steps of: a condensation step in which hydrolysis and dehydration condensation of a silane compound are carried out using a neutral salt as a catalyst, The condensation step a silane compound (A) having a radical polymerizable unsaturated group and a hydrolyzable silyl group; The following general formula (I) other than the above (A): R １ ｎ -Si-(OR ２ ) ４－ｎ ・・・(I) (In the formula, R １ are each independently an alkyl group having 1 to 10 carbon atoms or an unsubstituted or substituted aryl group, and R ２ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 0 to 3; carrying out hydrolysis and dehydration condensation of a mixture containing the neutral salt is a salt consisting of a combination of a cation selected from the group consisting of lithium ions, magnesium ions, and tetraalkylammonium ions and an anion selected from the group consisting of chloride ions and bromide ions; The amount of condensation water in the condensation step is 0.5 to 1.5 equivalents relative to the hydrolyzable groups possessed by (A) and (B).

2. The method according to claim 1 , further comprising, after the condensation step, a polymerization step of adding a monomer (C) having a radically polymerizable unsaturated group and carrying out radical polymerization.

3. The production method according to claim 2, wherein the monomer (C) having a radical polymerizable unsaturated group has a salt structure consisting of an acid and a base and includes a monomer (C') having a radical polymerizable unsaturated group.

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