WO2014112586A1 - Composition containing polymer of polyoxyalkylene-modified vinyl alcohol type - Google Patents

Abstract

The purpose of the present invention is to provide a composition which can exhibit such excellent temperature-sensitive thickening properties that the composition has a low viscosity at a lower temperature and is therefore easy to handle and is rapidly thickened when the temperature of the composition is raised. The present invention is a composition comprising a vinyl-alcohol-type polymer that contains a monomer unit having a polyoxyalkylene group and a surfactant, wherein the polyoxyalkylene group contains a block represented by formula (1), the amount of a constituent unit of the block is 50 mol% or more relative to the amount of the polyoxyalkylene group, the content of the monomer unit is 0.05 to 10 mol% inclusive relative to the content of the monomer unit of the vinyl-alcohol-type polymer, the vinyl-alcohol-type polymer has a viscosity average polymerization degree of 150 to 5,000 inclusive and a saponification degree of 40 to 99.99 mol% inclusive, and the surfactant is a compound represented by formula (I).

Description

Composition containing polyoxyalkylene-modified vinyl alcohol polymer

The present invention relates to a composition containing a vinyl alcohol polymer containing a monomer unit having a polyoxyalkylene group.

A vinyl alcohol polymer (hereinafter sometimes abbreviated as “PVA”) is a few crystalline water-soluble polymers, and has excellent film-forming properties, interface properties, and strength properties. For this reason, PVA is widely used as a raw material for thickeners, paper coating agents, adhesives, fiber processing agents, binders, emulsion stabilizers, films, fibers and the like. Moreover, in order to improve the specific performance of PVA, development of modified PVA by controlling crystallinity, introducing functional groups, and the like has been performed. Furthermore, a PVA-boric acid crosslinking solution in which boric acid or the like is added to PVA to cause a crosslinking reaction is used for the purpose of controlling shape retention performance or improving the strength of the PVA matrix. However, in recent years, the amount of boric acid and the like has begun to be regulated due to the toxicity of boron, etc., and instead of PVA-boric acid crosslinking solution, PVA whose viscosity can be controlled by temperature and a composition containing the same Is required.

Therefore, as a method for controlling the behavior of the solution viscosity of PVA with respect to temperature change, in the PVA having a polyoxyalkylene group (hereinafter sometimes abbreviated as “POA group”), the content of the POA group and the POA group It has been proposed to improve the temperature-sensitive thickening by adjusting the number of repeating units of the oxyalkylene group (see JP 2008-291120 A and JP 10-338714 A). However, although PVA having such a POA group exhibits temperature-sensitive thickening, the change in viscosity due to the temperature is insufficient, and it is difficult for temperature-sensitive thickening to occur at low concentrations, or the viscosity does not increase even at low temperatures. There are inconveniences such as high handling and poor handling. Under such circumstances, it is required to improve the handling property at low temperature and the temperature-sensitive thickening.

JP 2008-291120 A Japanese Patent Laid-Open No. 10-338714

The present invention has been made based on the above-mentioned circumstances, and aims to provide a composition that can exhibit excellent temperature-sensitive thickening that has a low viscosity at low temperatures and is excellent in handleability, and that rapidly thickens as the temperature rises. To do.

The invention made to solve the above problems is
A vinyl alcohol polymer containing a monomer unit having a polyoxyalkylene group (hereinafter sometimes abbreviated as “POA-modified PVA”), and a surfactant;
The polyoxyalkylene group includes a block represented by the following formula (1) (hereinafter also referred to as “block (1)”),
The structural unit of the block is 50 mol% or more based on the polyoxyalkylene group,
The content of the monomer unit is 0.05 mol% or more and 10 mol% or less with respect to the monomer unit of the vinyl alcohol polymer, and the viscosity average polymerization degree of the vinyl alcohol polymer is 150 or more and 5,000. The saponification degree is 40 mol% or more and 99.99 mol% or less,
The surfactant is a composition represented by the following formula (I).

(In the formula (1), ^one of R ¹ and R ² is a methyl group or an ethyl group, and the other is a hydrogen atom. M represents the number of repeating units and is an integer of 10 to 40. The plurality of R ¹ and R ² may be the same or different.)

(In the formula (I), R ³ is an alkylene group having 3 to 5 carbon atoms. R ⁴ is a single bond or an alkylene group having 1 to 5 carbon atoms. X ¹ is a hydrogen atom or an organic group. X ² is a hydrophilic group, x is an integer of 1 to 100. When x is 2 or more, a plurality of R ³ each independently satisfy the above definition.

The aqueous solution of the composition contains a POA-modified PVA having a polyoxyalkylene group containing a block having the above specific structure and a surfactant having the above specific structure, so that the viscosity is low and the handling property is increased at a low temperature. Then, an excellent temperature-sensitive thickening that sharply thickens can be exhibited. Although the details of the mechanism by which the composition exhibits the above-mentioned effects have not been clarified, it can be presumed as follows, for example. That is, the POA-modified PVA can have a hydrophobic interaction with the surfactant having the specific structure by including the block having the specific structure. Here, the hydrophobicity of this surfactant is considered to change depending on the temperature. Since the POA-modified PVA has a block having the above specific structure, the hydrophobic interaction between the POA groups is small at low temperatures, and the surfactant does not affect the hydrophobic interaction between the POA groups. As a result, the composition has a low viscosity and excellent handleability at low temperatures. On the other hand, at a high temperature, in addition to the direct hydrophobic interaction between the POA groups, a stronger intermolecular crosslinking structure is formed by the interaction between the POA groups due to the intervention of the surfactant. As a result, the composition rapidly thickens as the temperature increases. Further, by setting the content of the monomer unit and the viscosity average polymerization degree and saponification degree of the POA-modified PVA within the specific ranges, the solubility of the composition in water, the temperature-sensitive viscosity increase, and the like are further improved. Can be made. Thus, it is thought that the said composition exhibits the above-mentioned outstanding temperature-sensitive viscosity increase by having the said structure.

The hydrophilic group of X ² is a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, or a group represented by the following formula (II).

(In formula (II), y is an integer of 1 or more and 200 or less.)

The hydrophilic group of the X ^2, With such a specific hydrophilic group, the interaction of POA groups and the surfactant described above is considered to be strong, as a result, the composition is excellent due to an increase in the temperature-sensitive viscous .

The organic group of X ¹ is an alkyl group having 1 to 29 carbon atoms or a hydrophilic group. The organic groups of the above X ¹ within the above specified groups, believed to interaction described above is stronger, the composition is excellent due to an increase in the temperature-sensitive viscosity.

Hydrophilic group of the above ^{X 1} is a group represented by the following formula (III).

(In formula (III), z is an integer of 1 or more and 200 or less.)

It is considered that the above-mentioned interaction is further strengthened by using X ¹ as the specific group, and the composition is more excellent in temperature-sensitive thickening.

The polyoxyalkylene group preferably further includes a block represented by the following formula (2) (hereinafter also referred to as “block (2)”).

(In formula (2), n represents the number of repeating units and is an integer of 1 to 50.)

It is considered that the above-mentioned interaction becomes stronger when the polyoxyalkylene group further contains the block (2), and as a result, the temperature-sensitive thickening of the composition is further improved.

The monomer unit preferably has the polyoxyalkylene group in the side chain. When the monomer unit has the polyoxyalkylene group in the side chain, the above-described interaction is considered to be further strengthened, and as a result, the temperature-sensitive thickening of the composition is further improved.

It is preferable that the block represented by the above formula (1) is located on the main chain side from the block represented by the above formula (2). It is considered that the above-described interaction is further strengthened by having each of the blocks at the specific position, and as a result, the temperature-sensitive thickening of the composition is further improved.

It is preferable that the block represented by the above formula (1) and the block represented by the above formula (2) are directly bonded. When these blocks are located adjacent to each other, it is considered that the above-described interaction is further strengthened, and as a result, the temperature-sensitive thickening of the composition is further improved.

The POA-modified PVA is preferably obtained by saponifying a copolymer of an unsaturated monomer represented by the following formula (3) and a vinyl ester monomer.

(In Formula (3), Y is a group that includes the block represented by Formula (1) and may include the block represented by Formula (2). R ⁵ represents a hydrogen atom or An alkyl group having 1 to 8 carbon atoms, R ⁶ is a hydrogen atom or a methyl group, X is —O—, —CH ₂ —O—, —CO—, — (CH ₂ ) _k —, —COO. - or -CO-NR ⁷ - and it .R ⁷ is .k a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, is an integer of 1-15).

Since the POA-modified PVA contained in the composition is obtained by saponifying the copolymer of the specific monomer, adjustment of the saponification degree of the POA-modified PVA is facilitated, and the temperature sensitivity is increased. The viscosity and the like can be further increased.

The mass ratio of the surfactant to the POA-modified PVA is preferably 3/100 or more and 70/100 or less. By setting the mass ratio of the surfactant and the POA-modified PVA within the above range, the temperature-sensitive thickening of the composition can be further increased.

Since the composition is excellent in handling property at low temperature and temperature-sensitive thickening, it is suitably used as a coating agent such as a paper coating agent and a glass fiber coating agent.

Since the composition is excellent in handleability at low temperatures and temperature-sensitive thickening, it is suitably used as a thickening agent for various emulsion adhesives.

The composition of the present invention has a low viscosity at a low temperature and excellent handleability, and can exhibit an excellent temperature-sensitive thickening that rapidly increases as the temperature rises. Therefore, the composition is suitably used as a coating agent, a thickener and the like.

Hereinafter, embodiments of the composition of the present invention will be described in detail.

<Composition>
The composition has a POA group containing a block represented by the formula (1) described in detail below, and the content of the monomer unit having this POA group (hereinafter also referred to as “POA group modification rate”). ), PVA having a specific range of saponification degree and viscosity average polymerization degree (hereinafter also referred to as “POA-modified PVA”) and a surfactant, the viscosity is low at low temperatures and excellent in handleability. Excellent temperature-sensitive thickening can be achieved. Although the details of the mechanism by which the composition exhibits the above-mentioned effects have not been clarified, it can be presumed as follows, for example. That is, the POA-modified PVA can have a hydrophobic interaction with the surfactant having the specific structure by including the block having the specific structure. Here, the hydrophobicity of this surfactant is considered to change depending on the temperature. Since the POA-modified PVA has a block having the above specific structure, the hydrophobic interaction between the POA groups is small at low temperatures, and the surfactant does not affect the hydrophobic interaction between the POA groups. As a result, the composition has a low viscosity and excellent handleability at low temperatures. On the other hand, at a high temperature, in addition to the direct hydrophobic interaction between the POA groups, a stronger intermolecular crosslinking structure is formed by the interaction between the POA groups due to the intervention of the surfactant. As a result, the composition rapidly thickens as the temperature increases. Further, by setting the content of the monomer unit and the viscosity average polymerization degree and saponification degree of the POA-modified PVA within the specific ranges, the solubility of the composition in water, the temperature-sensitive viscosity increase, and the like are further improved. Can be made. Thus, it is thought that the said composition exhibits the above-mentioned outstanding temperature-sensitive viscosity increase by having the said structure.

The composition usually further contains water. The composition may be one in which the POA-modified PVA, the surfactant and water are simultaneously dissolved, or a composition obtained by adding a surfactant to a POA-modified PVA aqueous solution. The composition can also include a water-containing solvent. Here, the water-containing solvent is composed of water and a solvent other than water. The composition may contain an optional component in addition to the above components as long as the effects of the present invention are not impaired. Hereinafter, these components will be described in detail.

<POA-modified PVA>
The POA-modified PVA contains a monomer unit having a polyoxyalkylene group containing a block represented by the above formula (1) (hereinafter also referred to as “block (1)”). The content ratio of the structural unit of the block (1) to the polyoxyalkylene group, that is, the ratio of the structural unit of the block (1) to the total structural units of the polyoxyalkylene group needs to be 50 mol% or more. 50 mol% or more and 99 mol% or less is preferable, and 60 mol% or more and 95 mol% or less is more preferable. Here, the “block” refers to a portion composed of a chain structure of predetermined structural units.

In formula (1), ^one of R ¹ and R ² is a methyl group or an ethyl group, and the other is a hydrogen atom. m represents the number of repeating units and is an integer of 10 or more and 40 or less. A plurality of R ¹ and R ² may be the same or different.

Examples of the block (1) include a polyoxypropylene block in which the number of repeating units of oxypropylene units is m, a polyoxybutylene block in which the number of repeating units of oxybutylene units is m, and the like.

The number m of repeating units of the oxyalkylene unit in the block (1) needs to be an integer of 10 to 40, preferably 15 to 38, and more preferably 20 to 35. When m is less than 10, the temperature-sensitive thickening due to the interaction between the POA group and the surfactant is not sufficiently exhibited.

One of R ¹ and R ^{2 in} the above formula (1) is a methyl group or an ethyl group, and the other is a hydrogen atom. Among these, it is preferable that R ¹ is a methyl group and R ² is a hydrogen atom because the POA-modified PVA is easy to produce.

The polyoxyalkylene group preferably further includes a block represented by the above formula (2) (hereinafter also referred to as “block (2)”). In the composition, when the monomer unit further includes the block (2) in addition to the block (1), the temperature-sensitive thickening due to the interaction between the POA group and the surfactant is improved.

In the formula (2), n represents the number of repeating units and is an integer of 1 to 50.

Block (2) is a (poly) oxyethylene block in which the number of repeating units of oxyethylene units is n.

The number n of repeating units of oxyethylene units in the block (2) is preferably 3 or more and 40 or less, and more preferably 5 or more and 10 or less. When n exceeds 40, the interaction between POA groups decreases, and the temperature-sensitive thickening may not be sufficiently exhibited.

The polyoxyalkylene group may further include a block (a) different from the block (1) and the block (2). The said composition can also improve temperature-sensitive thickening by further including a block (a). Examples of the block (a) include a polyoxypentylene block, a polyoxyhexylene block, a polyoxystyrene block, a polyalkylene block, and a polyoxyethylene block having 51 to 70 repeating units.

The polyoxyalkylene group may be contained in any of the main chain, the side chain, and the terminal of the POA-modified PVA. From the viewpoint of enhancing the above-mentioned interaction and the viewpoint of ease of synthesis, the side chain or the terminal may be included. It is preferable that it is contained in. Here, the “main chain” refers to the longest chain among the chains formed by bonding a plurality of atoms constituting the POA-modified PVA. “Side chain” refers to a chain other than the main chain in the POA-modified PVA.

When the polyoxyalkylene group is included in the side chain and includes both the block (1) and the block (2), the block (1) is on the main chain side and the opposite side of the block (2). Although it may be located at any position, it is preferably located at the main chain side. Further, in this case, it is preferable that the block (1) and the block (2) are directly coupled. By setting the positions of the block (1) and the block (2) as described above, the above-mentioned interaction can be further strengthened, and as a result, the temperature-sensitive thickening of the composition can be further improved.

The POA-modified PVA is a copolymer containing a monomer unit containing a POA group and a vinyl alcohol unit (—CH ₂ —CHOH—), and may further contain other monomer units.

(Production of POA-modified PVA)
The method for producing the POA-modified PVA contained in the composition is not particularly limited, but the POA-modified vinyl ester system obtained by copolymerizing an unsaturated monomer containing a POA group and a vinyl ester monomer is obtained. A method of saponifying the polymer is preferred.

Here, the unsaturated monomer containing a POA group is preferably an unsaturated monomer represented by the following formula (3).

In Formula (3), Y is a group that includes a block represented by Formula (1) and may include a block represented by Formula (2). R ⁵ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁶ is a hydrogen atom or a methyl group. X is —O—, —CH ₂ —O—, —CO—, — (CH ₂ ) _k —, —COO— or —CO—NR ⁷ —. R ⁷ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. k is an integer of 1 to 15.

Examples of the alkyl group having 1 to 8 carbon atoms represented by R ⁵ include a methyl group, an ethyl group, a propyl group, and a butyl group. R ⁵ is preferably a hydrogen atom, a methyl group or a butyl group, more preferably a hydrogen atom or a methyl group.

In the above formula (3), when X is asymmetric, that is, —CH ₂ —O—, —COO—, or —CO—NR ⁷ —, the direction of X may be any. As the _{X, -O -, - CH 2} -O -, - CO-NR 7 - are preferred, -CO-NR ⁷ -, more preferably, -CO-NH- is more preferred. R ⁷ is preferably a hydrogen atom.

The direction of the group represented by Y (the arrangement of the block (1), the block (2), etc.) is as described above.

As the unsaturated monomer represented by the above formula (3), unsaturated monomers represented by the following formulas (3-1) to (3-3) are more preferable, and the following formula (3-1) The unsaturated monomer represented by is more preferable.

In the formulas (3-1) to (3-3), R ¹ , R ² and m are the same as in the above formula (1). n is the same as in the above formula (2). R ⁵ , R ⁶ and X are the same as in the above formula (3). “B” indicates that both adjacent units are formed by block copolymerization.

As an unsaturated monomer represented by the above formula (3), R ^{5 in the} above formula (3) is a hydrogen atom, R ⁶ is a hydrogen atom or a methyl group, and has a block (2). Examples include polyoxyalkylene mono (meth) acrylamide, polyoxyalkylene mono (meth) allyl ether, polyoxyalkylene monovinyl ether, polyoxyalkylene mono (meth) acrylate and the like.
Specifically, in the case where R ¹ in the block (1) is a methyl group and R ² is a hydrogen atom, polyoxypropylene (poly) oxyethylene monoacrylamide, polyoxypropylene (poly) oxyethylene monomethacrylamide, polyoxy Propylene (poly) oxyethylene monoallyl ether, polyoxypropylene (poly) oxyethylene monomethallyl ether, polyoxypropylene (poly) oxyethylene monovinyl ether, polyoxypropylene (poly) oxyethylene monoacrylate, polyoxypropylene (poly ) Oxyethylene monomethacrylate, etc.
When R ¹ is an ethyl group and R ² is a hydrogen atom, polyoxybutylene (poly) oxyethylene monoacrylamide, polyoxybutylene (poly) oxyethylene monomethacrylamide, polyoxybutylene (poly) oxyethylene monoallyl ether, Examples include polyoxybutylene (poly) oxyethylene monomethallyl ether, polyoxybutylene (poly) oxyethylene monovinyl ether, polyoxybutylene (poly) oxyethylene monoacrylate, polyoxybutylene (poly) oxyethylene monomethacrylate, and the like.

Among these, polyoxypropylene (poly) oxyethylene monoacrylamide, polyoxypropylene (poly) oxyethylene monomethacrylamide, polyoxypropylene (poly) oxyethylene monovinyl ether, polyoxypropylene (poly) oxyethylene monoallyl ether are Preferably used.

As the unsaturated monomer when R ^{5 in the} above formula (3) is an alkyl group having 1 to 8 carbon atoms, specifically, the unsaturated monomer exemplified when R ⁵ is a hydrogen atom. In which the terminal hydroxyl group is substituted with an alkoxy group having 1 to 8 carbon atoms. Among these, the terminal hydroxyl group of polyoxypropylene (poly) oxyethylene monomethacrylamide, polyoxypropylene (poly) oxyethylene monoallyl ether, polyoxypropylene (poly) oxyethylene monovinyl ether is replaced with a methoxy group or an ethoxy group The unsaturated monomer is preferably used.

The temperature at which the unsaturated monomer represented by the above formula (3) is copolymerized with the vinyl ester monomer is not particularly limited, but is preferably 0 ° C or higher and 200 ° C or lower, and 30 ° C or higher and 140 ° C or lower. Is more preferable. When the copolymerization temperature is lower than 0 ° C., it is difficult to obtain a sufficient polymerization rate. Moreover, when the temperature which superposes | polymerizes is higher than 200 degreeC, it is difficult to obtain POA modified PVA which has the POA group modification rate prescribed | regulated by this invention. As a method for controlling the temperature employed in the copolymerization to 0 ° C. or more and 200 ° C. or less, for example, by controlling the polymerization rate, the heat generated by the polymerization is balanced with the heat released from the surface of the reactor. And a method of controlling by an external jacket using an appropriate heat medium. The latter method is preferable from the viewpoint of safety.

The polymerization method employed for the copolymerization of the unsaturated monomer represented by the above formula (3) and the vinyl ester monomer is batch polymerization, semi-batch polymerization, continuous polymerization, or semi-continuous polymerization. Either is acceptable. As the polymerization method, an arbitrary method can be adopted from known methods such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Among these, a bulk polymerization method or a solution polymerization method in which polymerization is performed in the absence of a solvent or in the presence of an alcohol solvent is preferable. For the purpose of producing a copolymer having a high degree of polymerization, an emulsion polymerization method is employed. As the alcohol solvent used in the bulk polymerization method or the solution polymerization method, for example, methanol, ethanol, n-propanol or the like can be used. Two or more of these solvents may be used in combination.

As the initiator used for copolymerization, conventionally known azo initiators, peroxide initiators, redox initiators and the like may be appropriately selected according to the polymerization method. Examples of the azo initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4- Dimethyl valeronitrile) and the like, and peroxide initiators include perisopropyl compounds such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diethoxyethyl peroxydicarbonate; t-butyl Perester compounds such as peroxyneodecanate, α-cumylperoxyneodecanate, and t-butylperoxydecanate; acetylcyclohexylsulfonyl peroxide; 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate, etc. Is mentioned. Furthermore, the initiator can be combined with potassium persulfate, ammonium persulfate, hydrogen peroxide, or the like to form an initiator. Examples of the redox initiator include a combination of the above-described peroxide and a reducing agent such as sodium hydrogen sulfite, sodium hydrogen carbonate, tartaric acid, L-ascorbic acid, Rongalite and the like.

Further, when copolymerization of the unsaturated monomer represented by the above formula (3) and the vinyl ester monomer is performed at a high temperature, the coloring of the POA-modified PVA caused by the decomposition of the vinyl ester monomer Etc. may be seen. In that case, an antioxidant such as tartaric acid may be added to the polymerization system in an amount of 1 ppm to 100 ppm (relative to the mass of the vinyl ester monomer) for the purpose of preventing coloring.

Vinyl ester monomers used for copolymerization include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, and lauric acid. Examples thereof include vinyl, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate and the like. Of these, vinyl acetate is most preferred.

In the copolymerization of the unsaturated monomer represented by the above formula (3) and the vinyl ester monomer, other monomers may be copolymerized as long as the effects of the present invention are not impaired. Examples of monomers that can be used include α-olefins such as ethylene, propylene, n-butene, and isobutylene; acrylic acid and salts thereof; acrylic acid esters; methacrylic acid and salts thereof; methacrylic acid esters; acrylamide; N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropanesulfonic acid and its salt, acrylamidepropyldimethylamine and its salt or quaternary salt, N-methylolacrylamide and its derivative, etc. Acrylamide derivatives; methacrylamide; N-methyl methacrylamide, N-ethyl methacrylamide, methacrylamide propane sulfonic acid and salts thereof, methacrylamide propyl dimethylamine and salts thereof or Methacrylamide derivatives such as quaternary salts, N-methylol methacrylamide and derivatives thereof; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl Vinyl ethers such as vinyl ether, stearyl vinyl ether and 2,3-diacetoxy-1-vinyloxypropane; Nitriles such as acrylonitrile and methacrylonitrile; Vinyl halides such as vinyl chloride and vinyl fluoride; Vinylidene chloride and vinylidene fluoride Vinylidene halides such as allyl compounds such as allyl acetate, 2,3-diacetoxy-1-allyloxypropane, allyl chloride, etc .; unsaturated such as maleic acid, itaconic acid, fumaric acid, etc. And dicarboxylic acids and salts or esters thereof; vinylsilyl compounds such as vinyltrimethoxysilane; and isopropenyl acetate.

Furthermore, as another monomer, a monomer giving an α-olefin unit may be copolymerized within a range not impairing the effect of the present invention. The content of the α-olefin unit is preferably 1 mol% or more and 20 mol% or less.

Further, for the purpose of adjusting the degree of polymerization of the resulting POA-modified vinyl ester polymer upon copolymerization of the unsaturated monomer represented by the above formula (3) and the vinyl ester monomer, the present invention is used. Copolymerization may be carried out in the presence of a chain transfer agent as long as the effects of the invention are not impaired. Chain transfer agents include aldehydes such as acetaldehyde and propionaldehyde; ketones such as acetone and methyl ethyl ketone; mercaptans such as 2-hydroxyethanethiol; halogenated hydrocarbons such as trichloroethylene and perchloroethylene; sodium phosphinate 1 And phosphinic acid salts such as hydrates. Of these, aldehydes and ketones are preferred. The addition amount of the chain transfer agent may be determined according to the chain transfer constant of the added chain transfer agent and the degree of polymerization of the target POA-modified vinyl ester polymer. Usually, 0.1 mass% or more and 10 mass% or less are preferable with respect to a vinyl ester-type monomer.

The saponification reaction of the POA-modified vinyl ester polymer may be an alcoholysis decomposition reaction using a conventionally known basic catalyst such as sodium hydroxide, potassium hydroxide, sodium methoxide, or an acidic catalyst such as p-toluenesulfonic acid. Hydrolysis reactions can be applied. Examples of the solvent that can be used in this reaction include alcohols such as methanol and ethanol; esters such as methyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as benzene and toluene. These may be used alone or in combination of two or more. Among them, it is convenient and preferable to perform the saponification reaction using methanol or a methanol / methyl acetate mixed solution as a solvent and sodium hydroxide as a catalyst.

The POA group modification rate of the POA-modified PVA must be 0.05 mol% or more and 10 mol% or less, preferably 0.1 mol% or more and 5 mol% or less, preferably 0.1 mol% or more and 2 mol%. The following is more preferable, and 0.15 mol% or more and 1.5 mol% or less is more preferable. When the POA group modification rate exceeds 10 mol%, the proportion of POA groups contained in one molecule of the POA-modified PVA increases, so the water solubility of the POA-modified PVA decreases and the temperature-sensitive viscosity increases. On the other hand, when the POA group modification rate is less than 0.05 mol%, the water solubility of the POA modified PVA is excellent, but since the proportion of POA groups contained in one molecule of the POA modified PVA is low, the POA group and the surfactant The temperature-sensitive thickening due to the interaction is reduced.

The POA group modification rate is the ratio (mol%) of the number of moles of monomer units having POA groups including the block (1) to the number of moles of all monomer units constituting the POA-modified PVA. The POA group modification rate may be determined from POA-modified PVA or may be determined from the precursor POA-modified vinyl ester copolymer, which can be determined by proton NMR.

When the POA-modified PVA is composed only of a vinyl alcohol unit, a vinyl acetate unit and a polyoxypropylene (poly) oxyethylene monomethacrylamide unit as an unsaturated monomer unit represented by the above formula (3-1), The POA group modification rate can be calculated by the following method. That is, for example, when obtaining from a precursor POA-modified vinyl ester polymer (POA-modified polyvinyl acetate), specifically, first, a POA-modified vinyl ester polymer using a mixed solvent of n-hexane / acetone. After the reprecipitation purification is sufficiently performed three times or more, drying is performed under reduced pressure at 50 ° C. for 2 days to prepare a sample of POA-modified vinyl ester polymer for analysis. The sample is then dissolved in CDCl ₃ and measured at room temperature using proton NMR. Then, the area of the peak α (4.7 to 5.2 ppm) derived from the proton of the main chain methine of the vinyl ester monomer and the peak β (0.8 to 5.2 ppm) derived from the proton of the terminal methyl group of the oxypropylene unit. From the area of 1.0 ppm), the POA group modification rate can be calculated using the following formula. In the following formula, m represents the number of repeating units of oxypropylene units.

POA group modification rate (mol%) = [(Area of peak β / 3 m) / {Area of peak α + (Area of peak β / 3 m)}] × 100

Even when the POA-modified PVA has a structure other than the above structure, the POA group modification rate can be easily determined by appropriately changing the calculation target peak or calculation formula.

The viscosity average polymerization degree (P) of the POA-modified PVA used in the present invention (hereinafter sometimes abbreviated as “polymerization degree”) is measured according to JIS K6726. That is, after re-saponifying and purifying the above PVA, it is obtained from the intrinsic viscosity [η] (unit: deciliter / g) measured in water at 30 ° C. by the following formula. When mixing and using 2 or more types of PVA as POA modified PVA, the apparent viscosity average degree of polymerization of the whole PVA after mixing is made into the viscosity average degree of polymerization in that case.

Degree of polymerization = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

The degree of polymerization of the POA-modified PVA needs to be 150 or more and 5,000 or less, preferably 150 or more and 4,000 or less, more preferably 200 or more and 3,500 or less, and further preferably 200 or more and 3,000 or less. When the degree of polymerization exceeds 5,000, the productivity of the POA-modified PVA is lowered, which is not practical.

The saponification degree of the POA-modified PVA needs to be 40 mol% or more and 99.99 mol% or less, preferably 50 mol% or more and 99.9 mol% or less, and more preferably 60 mol% or more and 99 mol% or less. When the saponification degree is less than 40 mol%, the water solubility of the POA-modified PVA is lowered. On the other hand, if the degree of saponification exceeds 99.99 mol%, production of POA-modified PVA becomes difficult, which is not practical. The saponification degree of the POA-modified PVA is a value that can be measured according to JIS-K6726.

<Surfactant>
The surfactant contained in the composition is a compound represented by the following formula (I).

In the formula (I), R ³ is an alkylene group having 3 to 5 carbon atoms. R ⁴ is a single bond or an alkylene group having 1 to 5 carbon atoms. X ¹ is a hydrogen atom or an organic group. X ² is a hydrophilic group. x is an integer of 1 to 100. When x is 2 or more, a plurality of R ³ each independently satisfy the above definition.

The hydrophilic group of X ² is a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, or a group represented by the following formula (II). Examples of the counter cation in the carboxyl group salt or the sulfonic acid group salt include alkali metal cations such as sodium and potassium; alkaline earth metal cations such as calcium and barium; ammonium ions and the like. The hydrophilic group of the X ^2, With such a specific hydrophilic group, the interaction of POA groups and the surfactant described above is considered to be strong, as a result, the composition is excellent due to an increase in the temperature-sensitive viscous . Among these, X ² is preferably a sulfonic acid or a salt thereof, or a group represented by the following formula (II), and more preferably a group represented by the following formula (II).

In the formula (II), y is an integer of 1 to 200.

Y is preferably an integer of 2 or more, 100 or less, more preferably an integer of 2 or more and 40 or less, and further preferably an integer of 3 or more and 20 or less.

The organic group of X ¹ is an alkyl group having 1 to 29 carbon atoms or a hydrophilic group.

The alkyl group having 1 to 29 carbon atoms of X ¹ is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms.

Hydrophilic group of the above ^{X 1} is a group represented by the following formula (III).

In the formula (III), z is an integer of 1 or more and 200 or less.

Z is preferably an integer of 2 or more, 100 or less, more preferably an integer of 2 or more and 40 or less, and further preferably an integer of 3 or more and 20 or less.

X ¹ is a hydrogen atom, a hydrophilic group represented by the above formula (III), or an alkyl group having 1 to 29 carbon atoms. It is considered that the above-mentioned interaction becomes stronger when X ¹ is a hydrogen atom or the specific group, and the composition is more excellent in temperature-sensitive thickening.

Examples of the alkylene group having 3 to 5 carbon atoms represented by R ³ include a propanediyl group, a butanediyl group, and a pentanediyl group. Of these, a propanediyl group and a butanediyl group are preferable, and a 1,2-propanediyl group and a 1,4-butanediyl group are more preferable from the viewpoint that the surfactant has appropriate hydrophobicity.

Examples of the alkylene group having 1 to 5 carbon atoms represented by R ⁴ include a methylene group, an ethanediyl group, and a propanediyl group. R ⁴ is preferably a single bond.

X is preferably an integer of 2 to 60, more preferably an integer of 2 to 50, and still more preferably an integer of 3 to 30.

The surfactant is not particularly limited as long as it is a compound having a structure represented by the above formula (I).
Diblock copolymers or random copolymers such as polyethylene glycol-polypropylene glycol, polyethylene glycol-polytetramethylene glycol, polyethylene glycol-polybutylene glycol, polyethylene glycol-polypentylene glycol;
Triblock copolymers such as polyethylene glycol-polypropylene glycol-polyethylene glycol, polyethylene glycol-polytetramethylene glycol-polyethylene glycol, polyethylene glycol-polybutylene glycol-polyethylene glycol, polyethylene glycol-polypentylene glycol-polyethylene glycol;
Polypropylene glycol-sulfate sodium salt, polytetramethylene glycol-sulfate sodium salt, polybutylene glycol-sulfate sodium salt, polypentylene glycol-sulfate sodium salt;
Examples include polyethylene glycol-polypropylene glycol-alkyl ether. Among these, from the viewpoint of further improving the excellent handling property at a low temperature and the excellent temperature-sensitive thickening of the composition, a diblock copolymer of polyethylene glycol-polypropylene glycol, polyethylene glycol-polypropylene glycol-polyethylene glycol A triblock copolymer is preferable, and a polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer is more preferable.

The mass ratio of the surfactant contained in the composition to the POA-modified PVA (the mass of the surfactant / the mass of the vinyl alcohol polymer) is preferably from 3/100 to 70/100, and from 5/100 to 50. / 100 or less is more preferable, and 10/100 or more and 25/100 or less is more preferable. By setting the mass ratio of the surfactant to the POA-modified PVA within the above range, the handleability and temperature-sensitive thickening of the composition at a low temperature can be further increased.

<Solvent>
It does not specifically limit as said solvent which the said composition may contain, Water, an organic solvent, etc. are mentioned. Among these, at least a part of the solvent is water, that is, a water-containing solvent is preferable.

The content of water in the solvent is preferably 10% by mass or more, more preferably 40% by mass or more, and further preferably 70% by mass or more.

Although it does not specifically limit as said organic solvent, For example, alcohol solvents, such as methanol and ethanol;
Ester solvents such as methyl acetate and ethyl acetate;
Ether solvents such as diethyl ether, 1,4-dioxane, methyl cellosolve, cellosolve, butyl cellosolve, methyl-t-butyl ether, butyl carbitol;
Ketone solvents such as acetone and diethyl ketone;
Glycol solvents such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol;
Glycol ether solvents such as diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol;
Examples thereof include glycol ester solvents such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, and diethylene glycol monoethyl ether acetate.

When the viscosity of a 2% by weight aqueous solution of POA-modified PVA was measured with a BL-type viscometer under the condition of a rotor rotational speed of 6 rpm, the ratio η ₂ / η ₁ between the viscosity η _{1 at} 20 ° C. and the viscosity η _{2 at} 50 ° C. Is preferably 2 or more, more preferably 5 or more, still more preferably 10 or more, and particularly preferably 100 or more. Further, the viscosity ratio η ₂ / η ₁ is preferably 2,000 or less, and more preferably 1,000 or less.

<Optional component>
[Additive]
In addition to POA-modified PVA, the above-mentioned specific surfactant and solvent, the composition includes various plasticizers, antifoaming agents, ultraviolet absorbers, fillers, pH adjusters, water resistance, as long as the effects of the present invention are not impaired. It may contain additives such as an agent and a fluorescent brightening agent.

[Other water-soluble polymers]
As long as the effect of the present invention is not impaired, the composition is not limited to the above-described POA-modified PVA, but other various water-soluble polymers such as various types of PVA, starch, carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. May be contained.

<Method for preparing composition>
The composition can be prepared, for example, by mixing the POA-modified PVA, the surfactant, water, and optional components at a predetermined ratio. A method of mixing these components is not particularly limited, and POA-modified PVA may be added to a mixture of a surfactant and water, or a surfactant may be added to a POA-modified PVA solution. In addition, in order to improve solubility, you may stir, heating. As the solution temperature at the time of the heating, for example, 80 ° C. or more and 95 ° C. or less is adopted.

<Use of composition>
The composition is excellent in handleability because the increase in viscosity at low temperatures is suppressed even when the concentration of POA-modified PVA is high, and the viscosity increases rapidly at high temperatures and exhibits excellent temperature-sensitive thickening. In applications where temperature fluctuation is assumed, it can be suitably used as a viscosity modifier. Therefore, the composition comprises a coating agent such as a paper coating agent and a glass fiber coating agent; a thickener such as various emulsion adhesives; a viscosity modifier, a temperature-sensitive binder, a gelling agent, and a temperature-sensitive adhesive. It can be suitably used as an agent or the like. In addition, for example, internally added sizing agent; fiber processing agent; dye; metal or glass surface coating agent; coating agent such as anti-fogging agent; adhesive such as wood, paper, aluminum foil, plastic; non-woven binder; fibrous binder; Binders for building materials such as gypsum board and fiberboard; Additives for urea resin adhesives; Additives for cement and mortar; Hot melt adhesives; Various adhesives such as pressure sensitive adhesives; Ethylene, vinyl acetate, vinyl chloride Dispersants for emulsion polymerization of various ethylenically unsaturated monomers such as: Stabilizers for pigment dispersion such as paints and adhesives; Various ethylenic properties such as vinyl chloride, vinylidene chloride, styrene, (meth) acrylic acid, vinyl acetate Dispersion stabilizer for suspension polymerization of unsaturated monomers; molded products such as fibers, films, sheets, pipes, tubes, water-soluble fibers, and temporary films; hydrophilicity imparting agents for hydrophobic resins; ; It can be used as a component constituting a soil stabilizer and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. In the following examples and comparative examples, unless otherwise specified, parts and% represent parts by mass and mass%, respectively.

The physical properties of PVA obtained by the following production examples were measured according to the following method.

[Viscosity average degree of polymerization and degree of saponification]
The viscosity average polymerization degree and saponification degree of PVA were determined by the method described in JIS-K6726.

[PoA group modification rate (content of monomer unit)]
The POA group modification rate of PVA was determined by the method using proton NMR described above. The proton NMR was measured using JEOL GX-500 (500 MHz).

[Production Example 1] Production of PVA1 A 3 L reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, a monomer dropping port and an initiator addition port has 900 g of vinyl acetate, 100 g of methanol, and a POA group. Monomer A which is an unsaturated monomer (monomer A is represented by the above formula (3-1), and R ¹ , R ² , R ⁵ , R ⁶ , X, m and n are shown in Table 2. The arrangement of the oxypropylene unit and the oxyethylene unit is a block shape, and the block of the oxypropylene unit is located on the X side with respect to the block of the oxyethylene unit.) 3.7 g is charged and nitrogen bubbling is performed. Then, the system was purged with nitrogen for 30 minutes. Moreover, the solution which made the density | concentration 20% by melt | dissolving the monomer A in methanol as a delay solution was prepared, and nitrogen substitution was carried out by bubbling of nitrogen gas. The temperature of the reactor was increased, and when the internal temperature reached 60 ° C., 0.25 g of 2,2′-azobisisobutyronitrile (AIBN) was added to initiate polymerization. While the delay solution was added dropwise so that the monomer composition (ratio of vinyl acetate and monomer A) in the polymerization solution was constant, polymerization was performed at 60 ° C. for 3 hours, and then the polymerization was stopped by cooling. The total amount of monomers used until the polymerization was stopped was 17 g. Further, the solid content concentration when the polymerization was stopped was 26.2%. Subsequently, unreacted vinyl acetate was removed while occasionally adding methanol at 30 ° C. under reduced pressure to obtain a methanol solution (concentration 35%) of POA-modified vinyl ester polymer (POA-modified PVAc). Furthermore, 14.0 g of alkaline solution (10% methanol solution of sodium hydroxide) was added to 386 g of POA-modified PVAc methanol solution prepared by adding methanol to this solution (100.0 g of POA-modified PVAc in the solution). (POA modified PVAc concentration in saponified solution 25%, molar ratio of sodium hydroxide to vinyl acetate units in POA modified PVAc 0.03). After adding the alkaline solution, a gel-like material was formed in about 1 minute. This was pulverized with a pulverizer and allowed to stand at 40 ° C. for 1 hour to allow saponification to proceed, and then 500 g of methyl acetate was added to remain. The alkali was neutralized. After confirming that the neutralization was completed using a phenolphthalein indicator, a white solid was obtained by filtration, 2,000 g of methanol was added thereto, and a washing operation was carried out for 3 hours at room temperature. After this washing operation was repeated three times, the white solid obtained by centrifugal drainage was left to dry in a dryer at 65 ° C. for 2 days to obtain POA-modified PVA (PVA1). PVA1 had a viscosity average polymerization degree of 3,000, a saponification degree of 98 mol%, and a POA group modification rate of 0.2 mol%. Table 1 shows the production conditions, and Table 4 shows the measurement results of the degree of polymerization, the degree of saponification, and the POA group modification rate.

[Production Examples 2 to 13, 16 to 22, 24 and 25]
(Production of PVA 2-13, 16-22, 24 and 25)
Charge amount of vinyl acetate and methanol (before the start of polymerization), type of unsaturated monomer having POA group used during polymerization (Table 2), use amount and polymerization rate, concentration of POA-modified PVAc during saponification, acetic acid Each POA-modified PVA (PVA 2-13, 16-22, 24 and 25) was produced in the same manner as in Production Example 1, except that the molar ratio of sodium hydroxide to vinyl units was changed as shown in Table 1. . The production conditions are shown in Table 1, and the degree of polymerization, the degree of saponification, and the POA group modification rate are shown in Table 4, respectively.

[Production Example 14] (Production of PVA14)
Monomer I which is an unsaturated monomer having 850 g of vinyl acetate, 150 g of methanol and POA group was added to a 3 L reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube and an initiator addition port. Form I is represented by the above formula (3-1), and R ¹ , R ² , R ⁵ , R ⁶ , X, m and n are as shown in Table 2. The arrangement of oxypropylene units and oxyethylene units is as follows. It was block-shaped, and the block of oxypropylene units is located on the X side with respect to the block of oxyethylene units.) 42 g was charged, and the system was purged with nitrogen for 30 minutes while bubbling nitrogen. The temperature of the reactor was increased, and when the internal temperature reached 60 ° C., 0.25 g of 2,2′-azobisisobutyronitrile (AIBN) was added to start polymerization, and the polymerization was started at 60 ° C. for 3 hours. After the polymerization, the polymerization was stopped by cooling. The solid content concentration when the polymerization was stopped was 25.5%. Subsequently, unreacted vinyl acetate monomer was removed while occasionally adding methanol at 30 ° C. under reduced pressure to obtain a methanol solution (concentration 30%) of POA-modified vinyl ester polymer (POA-modified PVAc). Furthermore, 16.7 g of an alkali solution (10% methanol solution of sodium hydroxide) was added to 463.2 g of a methanol solution of POA-modified PVAc prepared by adding methanol thereto (120.0 g of POA-modified PVAc in the solution). Saponification was carried out (POA modified PVAc concentration in saponified solution 25%, molar ratio of sodium hydroxide to vinyl acetate units in POA modified PVAc 0.03). After adding the alkaline solution, a gel-like material was formed in about 1 minute. This was pulverized with a pulverizer and allowed to stand at 40 ° C. for 1 hour to allow saponification to proceed, and then 500 g of methyl acetate was added to remain. The alkali was neutralized. After confirming that the neutralization was completed using a phenolphthalein indicator, a white solid was obtained by filtration, 2,000 g of methanol was added thereto, and a washing operation was carried out for 3 hours at room temperature. This washing operation was repeated three times, and then the white solid obtained by centrifugal drainage was left to dry in a dryer at 65 ° C. for 2 days to obtain POA-modified PVA (PVA14). PVA14 had a viscosity average polymerization degree of 2,400, a saponification degree of 98 mol%, and a POA group modification rate of 0.2 mol%. Table 1 shows the production conditions, and Table 4 shows the measurement results of the degree of polymerization, the degree of saponification, and the POA group modification rate.

[Production Examples 15 and 23]
(Production of PVA 15 and 23)
Each POA-modified PVA (PVA15) was prepared in the same manner as in Production Example 14 except that the type of unsaturated monomer having a POA group used during polymerization (Table 2) and the amount used were changed as shown in Table 1. And 23) were produced. Table 4 shows the measurement results of the polymerization degree, saponification degree, and POA group modification rate of these POA-modified PVA.

[Production Examples 26 and 27]
(Production of PVA 26 and 27)
As an unsaturated monomer having a POA group used for polymerization, an unsaturated monomer represented by the following formula (3-2-1) (compound (3-2-1)) and a following formula (4): Production Examples, except that each of the unsaturated monomers (compound (4)) represented was used, and the amounts used and the amounts of vinyl acetate and methanol (before polymerization started) were changed as shown in Table 1. Each POA-modified PVA (PVA 26 and 27) was produced in the same manner as in Example 1. Table 4 shows the measurement results of the viscosity-average polymerization degree, saponification degree, and POA group modification rate of these POA-modified PVA.

In the compound (3-2-1), the oxypropylene unit and the oxyethylene unit are each arranged in a block shape, and the positions of the polyoxyethylene block and the polyoxypropylene block are as described in the above formula. .

In the above compound (4), “r” indicates that two types of units are randomly arranged.

[Production Example 28]
(Manufacture of PVA28)
700 g of vinyl acetate and 300 g of methanol were charged into a 3 L reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube and an initiator addition port, and the system was purged with nitrogen for 30 minutes while bubbling nitrogen. The temperature of the reactor was increased, and when the internal temperature reached 60 ° C., 0.25 g of 2,2′-azobisisobutyronitrile (AIBN) was added to start polymerization, and the polymerization was started at 60 ° C. for 3 hours. After the polymerization, the polymerization was stopped by cooling. The solid content concentration when the polymerization was stopped was 17.0% by mass. Subsequently, unreacted vinyl acetate monomer was removed while sometimes adding methanol under reduced pressure at 30 ° C. to obtain a methanol solution (concentration 30% by mass) of an unmodified vinyl ester polymer (unmodified PVAc). Furthermore, 16.7 g of an alkaline solution (10% by mass of sodium hydroxide in methanol) was added to 477.2 g of a methanol solution of unmodified PVAc prepared by adding methanol thereto (120.0 g of unmodified PVAc in the solution). Then, saponification was carried out (the concentration of unmodified PVAc in the saponified solution was 25 mass%, the molar ratio of sodium hydroxide to the vinyl acetate unit in the unmodified PVAc was 0.03). A gel-like material was formed in about 1 minute after the addition of the alkaline solution. This was pulverized with a pulverizer and allowed to stand at 40 ° C. for 1 hour to proceed with saponification, and then 500 g of methyl acetate was added to remove the remaining alkali. Neutralized. After confirming that the neutralization was completed using a phenolphthalein indicator, a white solid was obtained by filtration, 2,000 g of methanol was added thereto, and the mixture was allowed to stand and washed at room temperature for 3 hours. After the above washing operation was repeated three times, the white solid obtained by centrifugal drainage was left to dry in a dryer at 65 ° C. for 2 days to obtain unmodified PVA (PVA28). The polymerization degree of PVA28 was 1,700, and the saponification degree was 98.5 mol%. The production conditions for the unmodified PVA are shown in Table 1, and the degree of polymerization, the degree of saponification, and the POA group modification rate are shown in Table 4, respectively.

<Preparation of composition>
[Example 1]
Weight ratio of polyethyleneglycol-polypropyleneglycol-polyethyleneglycol triblock copolymer (surfactant A in Table 3) as a surfactant to 2 g of PVA1 (surfactant mass / POA-modified PVA) Mass) = 20/100 to a mixture, 98 g of distilled water was added at room temperature, and the mixture was stirred for 30 minutes using a three-one motor. Next, this solution was heated to 90 ° C. while stirring, and stirred as it was for 1 hour, and then cooled to room temperature to obtain a composition containing PVA1 at a concentration of 2% by mass. The obtained composition was subjected to solubility evaluation and solution evaluation (viscosity at 20 ° C. and viscosity at 50 ° C., and a viscosity ratio between the viscosity at 20 ° C. and the viscosity at 50 ° C.) according to the following methods. The results are shown in Table 4.

[Examples 2 to 25 and Comparative Examples 1 to 15]
Each composition was prepared in the same manner as in Example 1 except that the types of PVA and surfactant used, and the mass ratio of the surfactant and PVA were as shown in Table 4. Table 3 shows the types of surfactants used. In Table 3, surfactants A to E are surfactants represented by the formula (I).

<Evaluation>
About each composition obtained by the said Example and comparative example, solubility evaluation and viscosity evaluation were performed with the following method. The evaluation results are shown in Table 4. In Table 4, “-” indicates that no surfactant was added. Further, “* 1” in Table 4 indicates that PVA was not completely dissolved and could not be evaluated.

[Solubility evaluation]
The state of each of the prepared compositions was visually observed, and the solubility in water was determined according to the following criteria. In addition, when the following evaluation is A or B, it can be said that it is excellent in practicality.
A: Clear solution B: Slight turbidity C: Cloudy solution D: Undissolved

[Viscosity evaluation]
(Viscosity at 20 ° C. and viscosity at 50 ° C.)
Using a BL-type viscometer, the viscosity (mPa · s) of each composition prepared above was measured under the conditions of a rotor rotation speed of 6 rpm, 20 ° C. and 50 ° C., and the viscosity at 20 ° C. was η ₁ at 50 ° C. the viscosity was η _2.

(Temperature-sensitive thickening)
The viscosity ratio (η ₂ / η ₁ ) between η ₁ and η ₂ measured as described above was calculated, and the temperature-sensitive thickening was evaluated according to the following criteria. In addition, when the following evaluation is A to C, it can be said that the temperature-sensitive thickening is excellent.
A: 30 or more B: 15 or more and less than 30 C: 3 or more and less than 15 D: 1 or more and less than 3 E: less than 1

As shown in Table 4, it can be seen that the compositions of Examples 1 to 25 have low viscosity at 20 ° C. and excellent handleability, and rapidly thickened at 50 ° C. to exhibit excellent temperature-sensitive thickening. Further, Example 1 in which the degree of polymerization of POA-modified PVA, the POA group modification rate, the degree of saponification, the structure of the monomer units contained, the type of surfactant, and the mass ratio of the surfactant to the POA-modified PVA were specified. 2, 5 to 8, 10 to 13, 17 to 19 and 24 have been found to exhibit particularly excellent temperature-sensitive thickening (the solubility evaluation is A or more, and the temperature-sensitive thickening). Is greater than or equal to B).

On the other hand, when PVA does not satisfy the prescribed requirements (degree of polymerization, monomer unit type, POA group modification rate and degree of saponification) (Comparative Examples 1 to 6, 12, 14, 15), the structure of the surfactant In the case of not satisfying the prescribed requirements (Comparative Examples 7 to 10), and in the case of not using the surfactant (Comparative Examples 11 and 13), it was observed that the solubility and temperature-sensitive thickening were insufficient. .

The composition of the present invention has a low viscosity at a low temperature and excellent handleability, and can exhibit an excellent temperature-sensitive thickening that rapidly increases as the temperature rises. Therefore, the composition is suitably used as a coating agent, a thickener and the like.

Claims (9)

1. Containing a vinyl alcohol polymer containing a monomer unit having a polyoxyalkylene group, and a surfactant;
   The polyoxyalkylene group includes a block represented by the following formula (1),
   The structural unit of the block is 50 mol% or more based on the polyoxyalkylene group,
   The content of the monomer unit is 0.05 mol% or more and 10 mol% or less with respect to the monomer unit of the vinyl alcohol polymer, and the viscosity average polymerization degree of the vinyl alcohol polymer is 150 or more and 5,000. The saponification degree is 40 mol% or more and 99.99 mol% or less,
   A composition in which the surfactant is a compound represented by the following formula (I).
   

   

   (In the formula (1), ^one of R ¹ and R ² is a methyl group or an ethyl group, and the other is a hydrogen atom. M represents the number of repeating units and is an integer of 10 to 40. The plurality of R ¹ and R ² may be the same or different.)
   

   

   (In the formula (I), R ³ is an alkylene group having 3 to 5 carbon atoms. R ⁴ is a single bond or an alkylene group having 1 to 5 carbon atoms. X ¹ is a hydrogen atom or 1 carbon atom. Or an organic group selected from a hydrophilic group represented by the following formula (III): X ² is a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, or represented by the following formula (II). X is an integer of 1 to 100. When x is 2 or more, a plurality of R ³ each independently satisfy the above definition.)
   

   

   (In formula (II), y is an integer of 1 or more and 200 or less.)
   

   

   (In formula (III), z is an integer of 1 or more and 200 or less.)
2. The composition according to claim 1, wherein the polyoxyalkylene group further comprises a block represented by the following formula (2).
   

   

   (In formula (2), n represents the number of repeating units and is an integer of 1 to 50.)
3. The composition according to claim 1, wherein the monomer unit has the polyoxyalkylene group in a side chain.
4. The composition according to claim 3, wherein the block represented by the formula (1) is located on the main chain side from the block represented by the formula (2).
5. The composition according to claim 4, wherein the block represented by the formula (1) and the block represented by the formula (2) are directly bonded.
6. The composition according to claim 1, wherein the vinyl alcohol polymer is obtained by saponifying a copolymer of an unsaturated monomer represented by the following formula (3) and a vinyl ester monomer.
   

   

   (In Formula (3), Y is a group that includes the block represented by Formula (1) and may include the block represented by Formula (2). R ⁵ represents a hydrogen atom or An alkyl group having 1 to 8 carbon atoms, R ⁶ is a hydrogen atom or a methyl group, X is —O—, —CH ₂ —O—, —CO—, — (CH ₂ ) _k —, —COO. - or -CO-NR ⁷ - and it .R ⁷ is .k a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, is an integer of 1-15).
7. The composition according to claim 1, wherein a mass ratio of the surfactant to the vinyl alcohol polymer is 3/100 or more and 70/100 or less.
8. The composition according to claim 1, which is used as a coating agent.
9. The composition according to claim 1, which is used as a thickener.