WO2013125407A1

WO2013125407A1 - Moisture absorptive and desorptive polymer and material containing such polymer

Info

Publication number: WO2013125407A1
Application number: PCT/JP2013/053338
Authority: WO
Inventors: 小見山拓三
Original assignee: 日本エクスラン工業株式会社
Priority date: 2012-02-22
Filing date: 2013-02-13
Publication date: 2013-08-29
Also published as: KR20140126704A; JP5979215B2; KR101981697B1; CN104144952A; JPWO2013125407A1; CN104144952B

Abstract

[Problem] When moisture absorptive and desorptive microparticles are added to coatings or resin compacts in order to impart moisture absorptive and desorptive qualities, in cases such as when the material becomes wet with water, problems arise that include the appearance of the material becoming whitish or deformation occurring. As a result of diligent and continued research, the present inventor discovered that a vinyl-based polymer with a salt-type carboxyl group, a hydroxyl group, and a cross-linked structure, when compounded with a coating or resin compact, would provide both strong moisture absorptive and desorptive properties and outstanding water resistance, thus achieving the present invention. The purpose of the present invention is to provide, in a case where compounding is performed with a coating, resin compact, or the like, a polymer that can impart strong moisture absorptive and desorptive properties and strong moisture permeability and a polymer that can impart strong water resistance, as well as a material containing such a polymer. [Solution] A moisture absorptive and desorptive polymer characterized in that it contains 1-7 mmol/g of a salt-type carboxyl group and 0.01-10 mmol/g of a hydroxyl group and is a vinyl-based polymer with a cross-linked structure.

Description

Hygroscopic polymer and material obtained by containing the polymer

The present invention provides a moisture absorbing / releasing weight capable of providing a coating film or a resin molded body having high moisture absorption and moisture permeation performance and excellent water resistance by being added to a coating film or a resin molded body. The present invention relates to a coalescence and a molded body containing the polymer.

Conventionally, inorganic moisture absorbents such as lithium chloride, calcium chloride, magnesium chloride, and phosphorus pentoxide have been used as a means for removing moisture in the air, but these inorganic moisture absorbents have a high moisture absorption rate and a moisture absorption rate. However, since it has deliquescence, it has the disadvantages of being liquefied after moisture absorption to contaminate others, difficult to mold, and difficult to regenerate. Further, hygroscopic agents such as silica gel, zeolite, sodium sulfate, activated alumina, activated carbon and the like have a drawback in that they have a small amount of moisture absorption and a low moisture absorption rate and require a high temperature for regeneration. Moreover, when it mix | blends with a coating material and resin in order to provide hygroscopicity, the coating film and molded product which are obtained will be impaired by the appearance, such as becoming poor in transparency and uniformity.

In addition, Patent Document 1 describes organic high moisture absorbing / releasing fibers, but in the case of a fiber, the processability of itself is good, but in addition to paints, resins, etc., it should be mixed uniformly. Is difficult to use as an additive. Further, when trying to obtain fibers industrially, a certain degree of fiber diameter is required, and therefore there is a problem that the surface area cannot be increased so much that the moisture absorption and desorption rate is also reduced. Furthermore, when the reaction is carried out in a fibrous form, there is a problem that the reaction tends to be non-uniform and the production cost is increased.

On the other hand, Patent Document 2 describes hygroscopic fine particles, which is more desirable in terms of uniformity in addition to paints, resins, and the like. However, because of its high hydrophilicity, the coating film and resin molded product obtained by adding the fine particles have an appearance that becomes whitish or changes shape when wet with water. There is a problem in durability, that is, water resistance.

JP-A-5-132858 JP-A-8-225610

As a result of continuous researches, the present inventors have found that a vinyl polymer containing a salt-type carboxyl group and containing a hydroxyl group and having a crosslinked structure has high moisture absorption and desorption properties, and The present inventors have found that the blended coating film and the resin molded product have unprecedented water resistance and have completed the present invention. An object of the present invention is to provide a polymer capable of giving high moisture absorption / release properties and high moisture permeability when blended in a material, a polymer capable of giving excellent water resistance, and a material containing such a polymer. Is to provide.

That is, the above object of the present invention is achieved by the following means.
(1) A moisture-absorbing / releasing polymer characterized in that it is a vinyl polymer containing 1 to 7 mmol / g of salt-type carboxyl groups and 0.01 to 10 mmol / g of hydroxyl groups and having a crosslinked structure. .
(2) Contains a vinyl monomer having a structure capable of generating a salt-type carboxyl group by hydrolysis, a vinyl monomer having a structure capable of generating a hydroxyl group by hydrolysis, and a crosslinkable vinyl monomer The hygroscopic polymer as described in (1), which is obtained by hydrolyzing a copolymer obtained by polymerizing a monomer mixture.
(3) The moisture-absorbing / releasing polymer according to (1) or (2), wherein the form is particulate.
(4) A material containing the hygroscopic polymer according to any one of (1) to (3).
(5) A material obtained by molding a resin to which the hygroscopic polymer according to any one of (1) to (3) is added.
(6) A material provided with the hygroscopic polymer according to any one of (1) to (3) together with a binder resin.
(7) The material according to (5) or (6), wherein the resin has an electrophilic functional group.
(8) The material according to (5) or (6), wherein the resin is a urethane resin.

The hygroscopic polymer of the present invention has high hygroscopic performance, and a material having excellent hygroscopic performance and moisture permeability can be obtained by adding to the raw material. Furthermore, since the hygroscopic polymer of the present invention contains a hydroxyl group, it can react with an electrophilic functional group such as an isocyanate group to form a bond. By utilizing this property, it is possible to obtain a material in which the hygroscopic polymer is chemically bonded. The material of the present invention has excellent moisture absorption performance and moisture permeability performance and also has excellent water resistance.

2 is an infrared absorption spectrum of the hygroscopic fine particles 1. (Reference Example 1) 2 is an infrared absorption spectrum of fine particles 9; (Reference Example 1) 2 is an infrared absorption spectrum of the hygroscopic fine particles 2. (Reference Example 2) 2 is an infrared absorption spectrum of the fine particles 10. (Reference Example 2)

The hygroscopic polymer of the present invention contains a salt-type carboxyl group in an amount of 1 to 7 mmol / g, preferably 3 to 7 mmol / g. The salt-type carboxyl group is a polar group having high hydrophilicity for expressing hygroscopicity, and when it is intended to obtain high hygroscopic performance, it is preferable to contain as much of the group as possible. However, it is necessary to take an appropriate balance with respect to the ratio of the hydroxyl group and the crosslinked structure described later. Especially when the amount of the polar group exceeds 7 mmol / g, the ratio of the crosslinked structure that can be introduced becomes too small, and the superabsorbent resin. As a result, there are problems such as stickiness and volume change due to water swelling.

On the other hand, as the amount of the polar group decreases, the hygroscopic performance decreases. In particular, when the amount is less than 1 mmol / g, sufficient hygroscopic performance is often not obtained. Therefore, the amount of the polar group is preferably 1 mmol / g or more and more preferably 3 mmol / g or more in terms of moisture absorption performance.

Examples of the salt type of the carboxyl group, that is, the counter cation include, for example, alkali metals such as Li, Na, K, Rb, and Cs, alkaline earth metals such as Be, Mg, Ca, Sr, and Ba, Cu, Other metals such as Zn, Al, Mn, Ag, Fe, Co, and Ni, NH4, amine, and the like can be given. In addition, it does not deviate from this invention that the carboxyl group which uses H as a counter cation coexists with these salt-type carboxyl groups. In this case, the ratio of the total carboxyl group to the salt-type carboxyl group is not particularly limited, but the ratio of the salt-type carboxyl group is preferably higher from the viewpoint of moisture absorption / release rate.

The hygroscopic polymer of the present invention contains a hydroxyl group in an amount of 0.01 to 10 mmol / g, more preferably 0.01 to 9 mmol / g, still more preferably 0.05 to 1 mmol / g. The key to exhibiting excellent water resistance, which is the greatest point of the present invention, is that the hygroscopic polymer has a hydroxyl group. A polymer having a salt-type carboxyl group and a moisture absorption / release performance has been seen in the prior art, but there is no report of one having a hydroxyl group, let alone an electrophilic functional group such as an isocyanate group. No hygroscopic polymer capable of forming a covalent bond by this reaction has been known. Further, it has not been known so far that the water resistance of a molded article obtained by adding a hygroscopic polymer into which a hydroxyl group has been introduced to a urethane resin or the like is remarkably improved.

The present inventors have introduced a hydroxyl group into the moisture-absorbing / releasing polymer, and when such a polymer is added to a resin or the like having a component having an electrophilic functional group such as an isocyanate group such as a urethane resin, it has excellent water resistance. The present inventors have found that a resin molded body having properties can be obtained. This is thought to be due to the formation of covalent bonds by reaction with electrophilic functional groups such as isocyanate groups contained in resin constituents, as well as the formation of hydrogen bonds and ionic bonds by the hydroxyl groups themselves. . Although the mechanism of water resistance expression is not clear, it is considered that the affinity of the interface between the polymer of the present invention and the resin is improved by these bonds. That is, it is considered that the affinity of the interface is increased, so that the interface does not dissociate even when there is a volume change accompanying water absorption drying, and whitening and deformation are suppressed. Further, according to this mechanism, when the moisture-absorbing / releasing polymer of the present invention is blended with a resin, a binder, a matrix, or the like, an improvement in strength, wear resistance and the like can be expected.

Since the hydroxyl group is a functional group that exhibits water resistance as described above, it is preferable to contain as much of the group as possible in order to obtain high water resistance. However, as described above, it is necessary to appropriately balance the ratio of the salt-type carboxyl group and the cross-linked structure for exhibiting the hygroscopic performance. Specifically, when the hydroxyl group amount exceeds 10 mmol / g, it can be introduced. The ratio of the salt-type carboxyl group and the crosslinked structure becomes too small, resulting in problems such as reduced hygroscopic performance and severe water swelling. On the other hand, when the amount of hydroxyl groups is less than 0.01 mmol / g, sufficient water resistance cannot be obtained. Further, in practice, even when the amount of the hydroxyl group is as small as 1 mmol / g or less, a sufficient water resistance effect is often obtained. In this case, the selection range of the salt-type carboxyl group amount is widened, which is more preferable.

The hygroscopic polymer of the present invention has a crosslinked structure. A polymer containing a large amount of a salt-type carboxyl group or hydroxyl group having a high affinity with water, such as the hygroscopic polymer of the present invention, is in contact with water and becomes sticky or swells violently in water. In some cases, the polymer may be dissolved in water. When such a polymer is blended with a resin or the like, the characteristics may be adversely affected. In the hygroscopic polymer of the present invention, such a problem is prevented by introducing a crosslinked structure.

The cross-linked structure employed in the present invention is not particularly limited as long as it is not physically or chemically modified in accordance with moisture absorption or moisture release. Cross-linking by covalent bond, ionic cross-linking, polymer intermolecular interaction or crystal structure Any structure such as cross-linking may be used. Among these, a crosslinked structure by a covalent bond is most preferable from the viewpoint of strength and stability.

The hygroscopic polymer of the present invention is made of a vinyl polymer. Since vinyl-based polymers are composed of carbon-carbon bonds in the main chain, they are more chemically active than polyamide-based polymers containing carbon-nitrogen bonds in the main chain and polyester-based polymers having carbon-oxygen bonds. It is not easily affected, and has an advantage that it can be easily subjected to hydrolysis or neutralization when introducing a salt-type carboxyl group or hydroxyl group.

The form of the hygroscopic polymer itself in the present invention is not limited, but in the case of particles such as emulsions and powders, it can be used as an additive for various materials in various applications. Its application range is wide and useful. In the case of such particles, the size of the particles can be appropriately selected according to the use and is not particularly limited. However, when the average particle size is preferably 1000 μm or less, more preferably 100 μm or less, various additives As the range of application as a widening, it has a large practical value. Also, there is no particular limitation on the lower limit. In the case of an emulsion, it is preferably 0.03 μm or more, more preferably 0.05 μm or more from the viewpoint of ease of production. In the case of producing by suspension polymerization, the average particle size is about 1 to 5 μm at the smallest.

Regarding the moisture absorption performance of the hygroscopic polymer of the present invention, the saturated moisture absorption rate in an atmosphere of 20 ° C. and a relative humidity of 65% is preferably 10% by weight or more, more preferably 20% by weight or more. If the saturated moisture absorption is less than 10% by weight, it is inferior to general moisture-absorbing materials such as rayon and wool, so the practical value is halved. On the other hand, the upper limit is not particularly limited. However, the higher the saturated moisture absorption rate, the larger the water swellable characteristic. From this viewpoint, the saturated moisture absorption rate at 20 ° C. and relative humidity 65% is preferably 70% by weight. % Or less, more preferably 65% by weight or less.

Next, a method for producing the hygroscopic polymer of the present invention described above will be described. The hygroscopic polymer of the present invention is a vinyl polymer having a salt-type carboxyl group, a hydroxyl group, and a crosslinked structure as essential structures. Methods for introducing these essential structures are roughly divided into methods introduced during a polymerization reaction. And introducing after the polymerization reaction. The introduction method will be described in detail below for each structure. These introduction methods may be implemented so that each structure is introduced sequentially, but in practice, the introduction methods for each structure are appropriately combined, and manufacturing is performed so that each structure is introduced in parallel. Is more desirable.

First, the method for introducing a salt-type carboxyl group into a vinyl polymer is not particularly limited. For example, a method for obtaining a polymer using a monomer having a salt-type carboxyl group as a copolymerization component, a carboxyl group, A monomer obtained by using a monomer having a structure having a structure that can be converted into a carboxyl group by chemical modification after obtaining a polymer using the monomer as a copolymerization component. Examples thereof include a method in which a carboxyl group is introduced into the coalescence by chemical modification and changed into a salt form as required, or a method in which the above three methods are carried out by graft polymerization.

Examples of a method for obtaining a polymer using a monomer having a salt-type carboxyl group as a copolymerization component include vinyl containing a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl propionic acid, and the like. And / or a method using a vinylidene-based salt monomer as a copolymerization component.

Further, as a method for converting a salt form after using a monomer having a carboxyl group as a copolymerization component to obtain a polymer, for example, vinyl and / or vinylidene-based monomers containing a carboxyl group as described above can be used. In this method, the copolymer obtained using the monomer as a copolymerization component is converted into a salt form. The method for converting the carboxyl group into a salt form is not particularly limited, and the obtained copolymer may be an alkaline metal ion such as Li, Na, K, Rb, or Cs, or an alkaline earth such as Be, Mg, Ca, Sr, or Ba. Perform ion exchange by acting a solution containing a large amount of metal ions, other metal ions such as Cu, Zn, Al, Mn, Ag, Fe, Co, Ni, and organic cations such as NH4 and amine, etc. The method can be used.

Examples of a method for introducing a carboxyl group by chemical modification include, for example, subjecting a polymer obtained by using a monomer having a structure that can be obtained by hydrolysis to a carboxyl group as a copolymerization component to hydrolysis. In the case where a carboxyl group is introduced and it is not a salt type, a method of forming a salt type by the method as described above can be mentioned. Monomers having a structure capable of obtaining a carboxyl group by hydrolysis treatment include monomers having a cyano group such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinylpropionic acid, etc. Anhydrides and derivatives thereof, such as methyl (meth) acrylate, ethyl (meth) acrylate, normal propyl (meth) acrylate, isopropyl (meth) acrylate, normal butyl (meth) acrylate, (meth) Ester compounds such as normal octyl acrylate, 2-ethylhexyl (meth) acrylate, hydroxylethyl (meth) acrylate, (meth) acrylamide, dimethyl (meth) acrylamide, monoethyl (meth) acrylamide, normal-t-butyl (meth) ) Such as acrylamide Bromide and the like. Other methods for introducing a carboxyl group by chemical modification include oxidation of alkenes, alkyl halides, alcohols, aldehydes, and the like.

Next, the method for introducing a hydroxyl group into the vinyl polymer is not particularly limited. For example, a method of obtaining a polymer using a monomer having a hydroxyl group as a copolymerization component, or conversion into a hydroxyl group by chemical modification is possible. Examples thereof include a method of introducing a hydroxyl group by chemical modification into a polymer obtained using a monomer having a simple structure as a copolymerization component, or a method of carrying out the above two methods by graft polymerization.

Examples of a method for obtaining a polymer by using a monomer having a hydroxyl group as a copolymerization component include vinyl and / or vinylidene containing a hydroxyl group such as 4-hydroxylbutyl acrylate, hydroxylethyl (meth) acrylate, and hydroxypropyl methacrylate. The method of using a monomer of a system for a copolymerization component is mentioned.

As a method for introducing a hydroxyl group by chemical modification, for example, a copolymer obtained by using vinyl acetate, vinyl propionate, vinyl t-butanoate, vinyloxytrimethylsilane or the like as a copolymerization component is subjected to hydrolysis treatment. A method of introducing a hydroxyl group, ethyl vinyl ether, methyl vinyl ether, isobutyl vinyl ether, propyl vinyl ether, t-pentyl vinyl ether, 2-chloroethyl vinyl ether, butyl vinyl ether 2,2,2-trifluoroethyl vinyl ether, etc. Examples thereof include a method of introducing a hydroxyl group by subjecting the obtained copolymer to treatment with hydrogen halide or Lewis acid.

The method for introducing a crosslinked structure into the vinyl polymer is not particularly limited, and a method of polymerizing by adding a crosslinkable vinyl monomer as a copolymerization component in the polymerization stage, or a reaction after polymerization. It is possible to use a generally used method such as post-crosslinking with a functional compound or introduction of a crosslinked structure with physical energy. In particular, the method using a crosslinkable monomer in the polymerization stage and the method using post-crosslinking using a reactive compound after obtaining a polymer are preferable because it is possible to introduce strong cross-linking by a covalent bond.

As a monomer used in the method using a crosslinkable vinyl monomer, a monomer having a plurality of vinyl groups can be used. Examples include glycidyl methacrylate, N-methylol acrylamide, hydroxyethyl methacrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, methylenebisacrylamide, divinylbenzene, and the like. it can.

In selecting a crosslinkable vinyl monomer, it is desirable to select in consideration of the above-described method for introducing a salt-type carboxyl group or a hydroxyl group. For example, when using a vinyl monomer containing a carboxyl group, it is desirable to select one that can withstand an acidic atmosphere with such a monomer, and when introducing a hydroxyl group or a carboxyl group by a hydrolysis reaction It is desirable to select one that does not hydrolyze. From the viewpoint of being able to withstand such an acidic atmosphere or hydrolysis, a crosslinked structure with divinylbenzene is preferable among the examples described above.

In addition, there is no particular limitation on the method for introducing a crosslinked structure by post-crosslinking using a reactive compound. For example, a hydrazine compound is contained in a nitrile group contained in a nitrile polymer obtained from a vinyl monomer having a nitrile group. Or the method etc. which react formaldehyde and introduce | transduce a crosslinked structure can be mentioned. In particular, the method using a hydrazine-based compound is desirable in that it is stable against acids and alkalis and can contribute to improvement in hygroscopicity because the resulting crosslinked structure itself is hydrophilic. In addition, although the detail is not identified regarding the crosslinked structure obtained by reaction of a nitrile group and a hydrazine type compound, it is presumed to be based on a triazole ring or a tetrazole ring structure.

In the production of the hygroscopic polymer of the present invention, the method for introducing a salt-type carboxyl group, a hydroxyl group and a crosslinked structure is as described above. Needless to say, in polymerization, a vinyl-based unit which is not related to the introduction of these essential structures is used. It is also possible to appropriately select the monomer and use it as a copolymerization component.

The vinyl monomer that can be selected as such a copolymer component is not particularly limited, and vinyl halide compounds such as vinyl chloride, vinyl bromide, and vinyl fluoride; vinylidene chloride, vinylidene bromide, vinylidene fluoride, and the like Vinylidene-based monomers of; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid and their salts; methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, methoxyethyl acrylate, Acrylic esters such as phenyl acrylate and cyclohexyl acrylate; Methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate; methyl vinyl ketone, ethyl vinyl Ketones, Unsaturated ketones such as phenyl vinyl ketone, methyl isobutenyl ketone, methyl isopropenyl ketone; vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl monochloroacetate, vinyl dichloroacetate, vinyl trichloroacetate, Vinyl esters such as vinyl monofluoroacetate, vinyl difluoroacetate and vinyl trifluoroacetate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; acrylamide and alkyl-substituted products thereof; vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene Vinyl group-containing acid compounds such as sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, sulfopropyl methacrylate, vinyl stearic acid, vinylsulfinic acid, or salts thereof, anhydrous Styrene such as styrene, methylstyrene and chlorostyrene and alkyl or halogen substituted products thereof; Allyl alcohol and esters or ethers thereof; Vinylimides such as N-vinylphthalimide and N-vinylsuccinoimide; Vinylpyridine And basic vinyl compounds such as vinylimidazole, dimethylaminoethyl methacrylate, N-vinylpyrrolidone, N-vinylcarbazole and vinylpyridines; and unsaturated aldehydes such as acrolein and methacrylolein.

Preferable examples of the hygroscopic polymer employed in the present invention described above include vinyl polymer particles having a crosslinked structure with divinylbenzene and salt-type carboxyl groups and hydroxyl groups. In this case, the amount of divinylbenzene used is not particularly limited and may be set so that the intended function can be achieved. However, it should be 3 to 40% by weight based on the total amount of monomers normally used. Is preferred. If the amount is 3% by weight or less, the resulting particles are swelled with water and may become extremely sticky. On the other hand, when the amount is 40% by weight or more, the salt-type carboxyl group amount decreases, so that sufficient moisture absorption performance may not be obtained.

As a method for producing such vinyl polymer particles, the method described above may be adopted, for example, a method in which a vinyl monomer having a vinyl monomer having divinylbenzene and a carboxyl group and a hydroxyl group is graft-polymerized, Examples include a method of copolymerizing divinylbenzene, a vinyl monomer having a carboxyl group and a vinyl monomer having a hydroxyl group, but it is easy to produce, and the crosslinking density, the amount of salt-type carboxyl groups and the amount of hydroxyl groups can be easily set. In terms of controllability, divinylbenzene, a vinyl monomer having a structure capable of generating a salt-type carboxyl group by hydrolysis, a vinyl monomer having a structure capable of generating a hydroxyl group by hydrolysis, and further need A method of hydrolyzing a copolymer obtained by copolymerizing other vinyl monomers can be used.

The hygroscopic polymer of the present invention described above is useful as an additive for improving the hygroscopic performance and moisture permeability performance of various materials. Here, the material to which the hygroscopic polymer of the present invention can be applied is not particularly limited. For example, fibers, paper, nonwoven fabrics, yarns, woven fabrics, knitted fabrics, leathers, coating films, films, sheets, foams, rubbers. Etc. can be illustrated. Among these, when applied to materials such as paper, non-woven fabric, yarn, woven fabric, knitted fabric, foam, etc., the amount of moisture absorption and moisture transmission and moisture permeation is higher because of its large contact area with gas and excellent shape retention. A lot of material can be obtained.

As a method of containing the hygroscopic polymer of the present invention in these materials, as long as the hygroscopic polymer of the present invention is used, there is no particular limitation, kneaded into the material, directly fixed to the material, Or the method of making it adhere to a raw material with binder resin can be taken. Moreover, when the hygroscopic polymer of this invention has a fibrous form, the method of obtaining paper, a nonwoven fabric, etc. using a fibrous hygroscopic polymer for a constituent fiber is also employable.

About the method of kneading in a raw material, it can mainly apply to resin moldings, such as a fiber, a coating film, a film, a sheet | seat, a foam, rubber | gum. Specific examples of the method include injection molding, extrusion molding, melt spinning, solution spinning, and coating using a resin mixed with the hygroscopic polymer of the present invention.

Moreover, there is no limitation in particular as a kind of resin which comprises the resin molding which can apply this method, A phenol resin, an epoxy resin, a melamine resin, a urea resin, an unsaturated polyester resin, an alkyd resin, a urethane resin, thermosetting Thermosetting resins such as polyimide, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, polytetrafluoroethylene, ABS resin, AS resin, acrylic resin, and other thermoplastic resins, polyamide, polyacetal, polycarbonate Examples thereof include synthetic resins and natural resins such as engineering plastics such as modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, and cyclic polyolefin.

Moreover, as resin which comprises a resin molding, what has the high water vapor permeability is desirable. In the resin molded body, contact between the moisture-absorbing / releasing polymer of the present invention and water vapor is limited, so that the moisture-absorbing / releasing performance inherent to the moisture-releasing / releasing polymer of the present invention may not be sufficiently exhibited. . However, by adopting a resin having a high water vapor permeability as the resin, the moisture absorbing / releasing polymer of the present invention can easily come into contact with water vapor, and the moisture absorbing / releasing performance can be more easily exhibited. Further, in this case, a resin molded body having more excellent moisture permeability can be obtained by adding the moisture absorption / release property of the moisture absorption / release polymer of the present invention to the water vapor permeability inherent in the resin.

In addition, when the resin component has a functional group or structure capable of reacting with a hydroxyl group to form a covalent bond or forming a hydrogen bond or an ionic bond with the hydroxyl group, as described above, Also, the water resistance that decreases due to the addition of the hygroscopic polymer is desirable because it can be suppressed. Specific examples of functional groups and structures that can achieve this effect include isocyanate groups, ester groups, amide groups, halogen groups, epoxy groups, carboxyl groups, hydroxyl groups, amino groups, thiol groups, and the like. Among these, functional groups having electrophilicity such as isocyanate groups, ester groups, amide groups, halogen groups, and epoxy groups react with hydroxyl groups to form covalent bonds, and are firmly bonded to the resin molded body. Therefore, the effect of suppressing the decrease in water resistance is also increased.

From the viewpoint of suppressing water vapor permeability and water resistance reduction as described above, examples of suitable resins include urethane resins that form a large number of hydrophilic structures such as urethane bonds and that contain components having isocyanate groups. Can do.

Next, with respect to the method of directly fixing to the material, from the viewpoint of suppressing the removal of the hygroscopic polymer from the material, functional groups capable of reacting with hydroxyl groups and forming covalent bonds on the material surface, hydroxyl groups and hydrogen It can be suitably applied to a material having a functional group capable of forming a bond or an ionic bond. Among these, materials having an electrophilic functional group such as an isocyanate group, ester group, amide group, halogen group, epoxy group and the like capable of forming a covalent bond are suitable, and a material having an isocyanate group is particularly suitable.

Specific examples of the method include a method of impregnating or applying a slurry or emulsion of particulate hygroscopic polymer on paper, non-woven fabric, yarn, woven fabric, knitted fabric, sheet, foam or the like. Further, in the case of paper, a method of incorporating a particulate or fibrous hygroscopic polymer in the production process, or in the case of a nonwoven fabric, it is added in the production process and the thermal adhesiveness constituting the nonwoven fabric. A method of fixing to fibers or the like can also be employed.

Further, the method for fixing the moisture-absorbing / releasing polymer of the present invention to the material with the binder resin can be applied to various materials including the materials exemplified above. Here, the binder resin to be used may be appropriately selected according to the material, and examples thereof include the above-described thermosetting resins and thermoplastic resins. Further, as in the case of the resin molded body described above, the resin used as the binder resin is preferably one having high water vapor permeability. Furthermore, from the viewpoint of suppressing the decrease in water resistance and the viewpoint of further suppressing the dropping, those having a functional group capable of reacting with a hydroxyl group to form a covalent bond and a hydroxyl group capable of forming a hydrogen bond or an ionic bond. Of these, binder resins having an electrophilic functional group such as an isocyanate group, an ester group, an amide group, a halogen group, and an epoxy group that can form a covalent bond are preferable. And urethane resin can be used suitably as binder resin which satisfy | fills all these preferable aspects.

As a specific method, the binder resin solution containing the hygroscopic polymer of the present invention is applied to fibers, paper, nonwoven fabric, yarn, woven fabric, knitted fabric, leather, coating film, film, sheet, foam, rubber, etc. Examples thereof include a method of applying or spraying the material, a method of immersing these materials in the binder resin solution, and the like.

Further, the amount of the hygroscopic polymer of the present invention added to the raw material may be appropriately set according to the required hygroscopic performance, but in the normal case, it is in the range of 1 to 80% by weight with respect to the raw material. It is appropriate to set within. If it exceeds 80% by weight, the moisture-absorbing / releasing polymer tends to fall off and deformation due to water swelling often increases. In particular, when it is kneaded into a resin molding, it becomes difficult to mold. come. In addition, when the amount is less than 1% by weight, there are many cases where the effect of improving the moisture absorption / release performance is not manifested.

In addition, the hygroscopic polymer of the present invention forms a number of chemical bonds with the material, resulting in a state in which the material components are cross-linked, so that the mechanical strength of the material is improved. The effect can also be expected.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. In addition, unless otherwise indicated, the part and percentage in an Example are shown on a weight basis. First, an evaluation method for each characteristic will be described.

<Saturated moisture absorption rate>
About 1.0 g of sample particles are dried with a hot air dryer at 105 ° C. for 16 hours and weighed (Wds [g]). Next, the sample particles are kept at a temperature of 20 ° C. and adjusted to a relative humidity of 65% RH. The sample particles were allowed to stand for 24 hours in a humidifier and the weight of the absorbed sample particles was measured (Wws [g]).
Saturated moisture absorption [%] = {(Wws−Wds) / Wds} × 100

<Average particle size>
The average particle size of the particles was measured by using a laser diffraction particle size distribution measuring device “SALD2000” manufactured by Shimadzu Corporation and measured using water as a dispersion medium, and the median size was defined as the average particle size.

<Hydroxyl group content>
The amount of hydroxyl groups other than Example 6 is obtained by first conducting an elemental analysis of the sample after polymerization and before hydrolysis, and measuring the oxygen atom weight ratio and nitrogen content, whereby the vinyl acetate unit content (A [mmol / g]) And acrylonitrile unit content (B [mmol / g]) was calculated | required. After that, by infrared spectroscopic measurement of the sample after hydrolysis, it was confirmed that the vinyl acetate unit and acrylonitrile unit were completely hydrolyzed. Hydroxyl group (vinyl alcohol unit) and salt-type carboxyl group (sodium acrylate unit) The weight change was calculated as having been completely converted into the above and calculated from these numerical values.
Weight change of vinyl acetate unit to 1g of raw material polymer [g]
= 0.044A-0.086A = -0.042A
Change in weight of acrylonitrile unit per gram of raw polymer [g]
= 0.094B-0.053B = 0.041B}
Amount of hydroxyl group [mmol / g] = A / (1-0.042A + 0.041B)

<Amount of salt-type carboxyl group>
The amount of salt-type carboxyl groups was determined by subtracting the amount of H-type carboxyl groups from the total amount of carboxyl groups. First, 1 g of a sufficiently dried sample was precisely weighed (X [g]), 200 ml of water was added thereto, and then 1N hydrochloric acid aqueous solution was added to the sample while heating to 50 ° C. to adjust the pH to 2. All the carboxyl groups contained were converted to H-type carboxyl groups, and then a titration curve was determined according to a conventional method using a 0.1N aqueous sodium hydroxide solution. The consumption amount (Y [ml]) of the sodium hydroxide aqueous solution consumed by the H-type carboxyl groups was determined from the titration curve, and the total amount of carboxyl groups contained in the sample was calculated by the following formula.
Total carboxyl group content [mmol / g] = 0.1 Y / X
Separately, a titration curve was similarly obtained without adjusting to pH 2 by adding a 1N hydrochloric acid aqueous solution during the above total carboxyl group amount measurement operation, and the amount of H-type carboxyl groups contained in the sample was obtained. From these results, the salt-type carboxyl group amount was calculated by the following formula.
Salt-type carboxyl group amount [mmol / g] = (total carboxyl group amount) − (H-type carboxyl group amount)

<Water resistance>
A sample for water resistance evaluation was prepared by mixing 6.5 g of polyisocyanate (Bernock DN-980K, manufactured by DIC), 5 g of sample particles, and 23.5 g of polyol (Acridic A-801-P, manufactured by DIC) into a PET film. After coating with a bar coater # 50, a product dried at 130 ° C. for 30 minutes was used. In the water resistance evaluation, after immersing the above sample in water for 10 minutes, the moisture on the surface is wiped off, and it is judged visually whether whitening is seen in the coated part. If whitening is seen, x, whitening is seen The case where it did not exist was marked as ◯.

<Hygroscopic expression rate>
The hygroscopic expression rate is the saturated moisture absorption rate (A [%]), the sample particle content (B [g / m ² ]) and the moisture absorption amount (C [g / m ² ]) in the water resistance evaluation sample. ), The moisture absorption amount (D [g / m ² ]) of a blank sample obtained by coating in the same manner except that the water resistance evaluation sample and sample particles are not added, and calculated by the following formula: is there. In addition, about the moisture absorption C and D, it measured by the method similar to the term of said saturated moisture absorption.
Hygroscopic expression rate (%) = [(CD) / B × 100] / A × 100

<Moisture permeability>
40 parts of sample particles and 100 parts of urethane resin (Superflex (registered trademark) E-4800, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are mixed and coated on a nylon mesh (200 mesh) with a thickness of 50 μm using a glass rod. And dry at room temperature. The moisture permeability of the resulting coated fabric is measured based on JIS L 1099 (A-1 method).

[Example 1]
A monomer mixture consisting of 74 parts of acrylonitrile, 1 part of vinyl acetate and 25 parts of divinylbenzene is added to 300 parts of an aqueous solution containing 0.5 parts of ammonium persulfate, and then 0.6 part of sodium pyrosulfite is added, followed by polymerization with a stirrer. Polymerize in a bath at 65 ° C. for 2 hours. The polymer obtained is filtered and washed with water. Next, 100 parts of the polymer was added to 567 parts of a 10% aqueous sodium hydroxide solution and subjected to a hydrolysis reaction at 95 ° C. for 48 hours. Subsequently, the obtained polymer was filtered and washed with water to obtain hygroscopic fine particles 1. The evaluation results of the particles are as shown in Table 1, and the water resistance was good. Moreover, when the hygroscopic expression rate was measured about the sample used by water resistance evaluation, it was 90.7% or more.

Further, when the hygroscopic fine particles 1 were pulverized so as to have an average particle diameter of 5 μm was used as a sample and the moisture permeability was measured by the above method, it was 91.0 g / m ² · h. This is higher than the moisture permeability 45.8 g / m ² · h measured in the same manner except that the hygroscopic fine particles 1 are not added, and the moisture permeability improving effect of the hygroscopic polymer of the present invention is improved. It is shown.

[Comparative Example 1]
In Example 1, hygroscopic fine particles 2 were obtained in the same manner as in Example 1 except that the monomer mixture was 75 parts of acrylonitrile and 25 parts of divinylbenzene. The evaluation result of this particle | grain is as Table 1, and it whitened by being immersed in water.

[Example 2]
In Example 1, hygroscopic fine particles 3 were obtained in the same manner as in Example 1 except that the monomer mixture was 64 parts of acrylonitrile, 1 part of vinyl acetate, and 35 parts of divinylbenzene. The evaluation results of the particles are as shown in Table 1, and the water resistance was good.

[Comparative Example 2]
A hygroscopic fine particle 4 was obtained in the same manner as in Example 1 except that the monomer mixture solution used was 65 parts of acrylonitrile and 35 parts of divinylbenzene. The evaluation result of this particle | grain is as Table 1, and it whitened by being immersed in water.

[Example 3]
In Example 1, the hygroscopic fine particles 5 were obtained in the same manner as in Example 1 except that the monomer mixture was composed of 56.7 parts of acrylonitrile, 8.3 parts of vinyl acetate, and 35 parts of divinylbenzene. It was. The evaluation results of the particles are as shown in Table 1, and the water resistance was good.

[Example 4]
In Example 1, hygroscopic fine particles 6 were obtained in the same manner as in Example 1 except that the monomer mixture was 5 parts of acrylonitrile, 60 parts of vinyl acetate, and 35 parts of divinylbenzene. The evaluation results of the particles are as shown in Table 1, and the water resistance was good.

[Example 5]
In Example 1, hygroscopic fine particles 7 were obtained in the same manner as in Example 1 except that the monomer mixture was 10 parts of acrylonitrile, 65 parts of vinyl acetate and 25 parts of divinylbenzene. The evaluation results of the particles are as shown in Table 1, and the water resistance was good.

[Example 6]
A monomer mixture consisting of 10 parts of methacrylic acid, 3 parts of 4-hydroxylbutyl acrylate, 62 parts of acrylonitrile and 25 parts of divinylbenzene is added to 300 parts of an aqueous solution containing 0.5 parts of ammonium persulfate, followed by 0. Add 6 parts, and polymerize in a polymerization tank equipped with a stirrer at 65 ° C. for 2 hours. The polymer obtained is filtered and washed with water. The amount of methacrylic acid and 4-hydroxylbutyl acrylate introduced into the polymer was determined by analyzing the cleaning liquid by gas chromatography. Next, 100 parts of the polymer was added to 567 parts of a 2% aqueous sodium carbonate solution, and the carboxyl group was neutralized at 30 ° C. for 4 hours. Next, the obtained polymer was filtered and washed with water to obtain hygroscopic fine particles 8. The evaluation results of the particles are as shown in Table 1, and the water resistance was good. In addition, regarding the amount of hydroxyl groups at this time, the change in weight due to the theoretical neutralization reaction of the methacrylic acid unit (A [mmol / g]) obtained by the gas chromatography analysis and 4 obtained by the gas chromatography analysis were obtained. -Calculated from the amount of introduced hydroxyl butyl acrylate units (B [mmol / g]).
Change in weight of methacrylic acid unit per gram of raw polymer [g]
= 0.108A-0.086A = 0.022A
Hydroxyl amount [mmol / g] = B / (1 + 0.022A)

[Example 7]
5 g of hygroscopic fine particles 1, 27.8 g of bisphenol A diglycidyl ether, 2.2 g of dicyandiamide and 0.8 g of dimethylurea were mixed and coated on a PET film with a bar coater, and then dried at 120 ° C. for 30 minutes. A sample prepared by adding the hygroscopic fine particles 1 to the epoxy resin is prepared. Using this measurement sample, water resistance and hygroscopicity were evaluated in the same manner as described above. The sample did not whiten even after being immersed in water and showed good water resistance. Also, the hygroscopic expression rate was as good as 85.1%.

[Reference Example 1]
In addition, 1 part of phenyl p-cyanoisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 50 parts of methyl ethyl ketone, 2 parts of hygroscopic fine particles 1 were added and stirred at 80 ° C. for 12 hours, and then the particles were filtered and 3 parts with acetone. Fine particles 9 washed twice and dried at 50 ° C. for 12 hours were obtained. The infrared absorption spectrum of the particles is shown in FIG. 2, and the infrared absorption spectrum of the hygroscopic fine particles 1 is shown in FIG. In FIG. 2, absorption is confirmed at 2241 cm ⁻¹ derived from a cyano group not found in FIG. 1 and 1739 cm ⁻¹ indicating a urethane bond. That is, a urethane bond and a cyano group are introduced into the fine particles 9 obtained by reacting the hygroscopic fine particles 1 with phenyl p-cyanoisocyanate. From this, the hydroxyl groups of the hygroscopic fine particles 1 react with the isocyanate groups. It is understood that a covalent bond is formed.

[Reference Example 2]
In the same manner as in Reference Example 1, except that the hygroscopic fine particles 2 were used instead of the hygroscopic fine particles 1, the same operation was performed to obtain fine particles 10. The infrared absorption spectrum of the particles is shown in FIG. 4, and the infrared absorption spectrum of the hygroscopic fine particles 2 is shown in FIG. 3 and 4 show substantially the same spectrum, and it is understood that the hygroscopic fine particles 2 having no hydroxyl group do not react with the isocyanate group.

The moisture-absorbing / releasing polymer and material of the present invention are used in various fields such as fibers, textile processed products, clothing, sheets, paper, nonwoven fabrics, films, binders, paints, adhesives, sensors, resins, electricity, and electronics. It can be widely used as a material that can impart moisture release performance and moisture permeability performance.

Claims

A hygroscopic polymer containing 1 to 7 mmol / g of a salt-type carboxyl group and 0.01 to 10 mmol / g of a hydroxyl group and having a crosslinked structure.
A monomer containing a vinyl monomer having a structure capable of generating a salt-type carboxyl group by hydrolysis, a vinyl monomer having a structure capable of generating a hydroxyl group by hydrolysis, and a crosslinkable vinyl monomer The hygroscopic polymer according to claim 1, wherein the hygroscopic polymer is obtained by hydrolyzing a copolymer obtained by polymerizing the mixture.
The moisture-absorbing / releasing polymer according to claim 1 or 2, wherein the form is particulate.
A material containing the hygroscopic polymer according to any one of claims 1 to 3.
A material obtained by molding a resin to which the hygroscopic polymer according to any one of claims 1 to 3 is added.
A material provided with the hygroscopic polymer according to any one of claims 1 to 3 together with a binder resin.
The material according to claim 5 or 6, wherein the resin has an electrophilic functional group.
The material according to claim 5 or 6, wherein the resin is a urethane resin.