JP6899433B2 - Surface treatment composition - Google Patents

Description

The present invention relates to a composition for surface treatment.

The water-absorbent polymer used for absorbing water generally consists of a crosslinked polymer, and therefore lacks moldability. Therefore, Patent Document 1 proposes to use a solvent-soluble resin having water absorption to mold the resin into an arbitrary shape. The technique described in the same document does not require properties other than moldability and water absorption of the water-absorbent polymer having moldability, and merely examines the moldability of the water-absorbent polymer.

Regarding the conventional technique for a water-absorbent polymer based on a viewpoint different from the moldability of the water-absorbent polymer, Patent Document 2 describes a compound having an enthalpy change of −0.05 kJ / g or less when in contact with water and water absorption. A fiber treatment agent composition containing a polymer is described. The technique described in the document is intended to impart a comfortable warming or cooling effect when the textile product is worn or used by application or spraying when the textile product is worn or used.

Japanese Unexamined Patent Publication No. 3-20364 Japanese Unexamined Patent Publication No. 2003-96662

By the way, although the absorber containing the water-absorbent polymer can absorb and retain the liquid, when the pressure is applied while holding the water, the liquid may revert from the absorber. Therefore, it is desirable to impart water repellency to the water-absorbent polymer to prevent the liquid from returning. However, since water absorption and water repellency are contradictory properties, it is not easy to achieve both.

Therefore, an object of the present invention is to provide a surface treatment composition that simultaneously imparts water absorption and water repellency to the surface of the object to be treated, suppresses the reversion of the liquid, and imparts waterproofness to the object to be treated. is there.

The present invention relates to (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. To provide a composition for surface treatment containing the above.

The present invention is a method for producing a water-absorbent article.
The present invention provides a method for producing a water-absorbent article, which comprises a step of treating the surface of any of the members constituting the water-absorbent article with the surface-treating composition.

Further, the present invention has (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. A surface treatment composition containing a polymer provides a water-absorbent article in which at least a part of the network structure of a member having the network structure is coated in a film shape.

The present invention also provides a method for surface-treating an object to be treated, which comprises a step of applying the above-mentioned surface treatment composition to the surface of the object to be treated.

Further, the present invention provides a method for improving the water absorption of the surface of the object to be treated, which comprises a step of applying the above-mentioned surface treatment composition to the surface of the object to be treated to improve the water absorption of the surface. ..

According to the present invention, there is provided a surface treatment composition that easily imparts water absorption and water repellency to the surface of an object to be treated and imparts waterproofness to the surface.

Hereinafter, the present invention will be described based on its preferred embodiment. The present invention relates to a composition for surface treatment. The surface treatment composition of the present invention is generally a fluid in its used state. By applying this to the object to be treated, the composition for surface treatment of the present invention simultaneously obtains water absorption retention and water repellency of a liquid in the application area of the composition for surface treatment on the surface of the object to be treated. , It suppresses the reversion of the liquid and makes the object to be treated acquired waterproofness. The waterproof property in the present invention means (i) the effect of absorbing the liquid due to the blending of the water-absorbent polymer, and (ii) the liquid that could not be absorbed by the coating target soaks into the coating target, causing stains. This means that the effect of suppressing the water repellency imparted to the application target is simultaneously exhibited.

The surface treatment composition of the present invention contains (A) a water-absorbent polymer as one of its constituent components. The water-absorbent polymer is preferably a material that absorbs and retains water to form a hydrogel that swells, for example, 3 times or more, more preferably 10 times or more, still more preferably 20 times or more, still more preferably 30 times its own weight. Those capable of absorbing more than twice the mass of water are preferably used. Further, this water-absorbent polymer is soluble in a volatile solvent.

"Soluble in a volatile solvent" means that at the operating temperature of the surface treatment composition of the present invention, 100 g of ethanol / water = 90/10 (mass ratio) mixed solvent and 5 g of the water-absorbent polymer (A) are used. The undissolved polymer remaining in the solvent has a solubility of 0.1 g or less when the mixture is mixed and stirred for 20 minutes.

The solubility of the water-absorbent polymer (A) was determined by a mixed solvent in which ethanol and water were mixed at a mass ratio of 9/1, 7/3, 6/4, 4/6, 3/7, and 1/9. The measurement is carried out using a mixed solvent having a ratio in which the water-absorbent polymer (A) is most dissolved at 25 ° C. with respect to 100 g of the mixed solvent. In a closed container, 100 g of the mixed solvent and powdered (A) were added until they did not dissolve even after stirring for 20 minutes, and the added mass a1 (g) of (A) and the contents of the container were added to filter paper ( Filter with No. 5c, 12 cm) manufactured by Advantech Co., Ltd., and after volatilizing the volatile solvent, the mass a2 (g) of (A) remaining on the filter paper is measured. At this time, a1-a2 is defined as the solubility (g). The solubility of the water-absorbent polymer (A) is preferably 1 g or more, more preferably 10 g or more, from the viewpoint of facilitating blending into the surface treatment composition. The upper limit of the solubility is not particularly limited, and the higher it is, the more preferable it is, but if it is about 3 g, a sufficiently satisfactory effect can be obtained.

As the water-absorbent polymer (A), for example, a polymer composed of polyurethane such as a copolymer containing saturated bismethylene diphenyl diisocyanate (SMDI) and a copolymer containing hexamethyl diisocyanate (HDI) is mentioned as suitable. Be done. Alternatively, a copolymer containing dimethylacrylamide (DMAA), a triblock copolymer containing a segment having a hydrophilic portion, a multi-block copolymer and the like can also be mentioned as suitable ones. Examples of the copolymer containing saturated bismethylene diphenyl diisocyanate (SMDI) include "Aquacork TWB" (trade name: manufactured by Sumitomo Seika Chemical Co., Ltd.) as a commercially available product. Other examples include "Accurin 46N" (trade name: manufactured by Dow Chemical Co., Ltd.) and "Accurin 44" (trade name: manufactured by Dow Chemical Co., Ltd.). Examples of commercially available products of the copolymer containing hexamethyldiisocyanate (HDI) include "ADEKA NOL GT-700" (trade name: manufactured by ADEKA Corporation) and the like. Examples of the copolymer containing dimethylacrylamide (DMAA) include block copolymers of dimethylacrylamide (DMAA) and Nt-butylacrylamide (TBAA), dimethylacrylamide (DMAA) and ureidopyrimidinone (UPy). Random copolymers and the like.

The water-absorbent polymer (A) is generally in the shape of particles in a state before it is dissolved in a volatile solvent. The shape of the particles of the water-absorbent polymer includes, for example, a spherical type, a spherical aggregate type, a lump type, a bale type, and an amorphous type, and in the present invention, any shape can be used without particular limitation. .. In the state before being dissolved in a volatile solvent, the average particle size of the water-absorbent polymer prevents the water-absorbent polymer from falling off from the object treated with the surface treatment composition of the present invention, and causes dust to fly. From the viewpoint of suppression, it is preferably 1 μm or more, more preferably 20 μm or more, and even more preferably 40 μm or more. The average particle size is preferably 5000 μm or less, more preferably 1000 μm or less, and even more preferably 100 μm or less, from the viewpoint of shortening the dissolution time of the polymer. The average particle size of the particles of the water-absorbent polymer is preferably 1 μm or more and 5000 μm or less, more preferably 20 μm or more and 1000 μm or less, and further preferably 40 μm or more and 100 μm or less.

The average particle size of the water-absorbent polymer is measured by the laser diffraction method specified in JIS Z 8825: 2013.

Regardless of the shape of the water-absorbent polymer (A) described above, the water absorption amount is preferably 5 g / g or more at 25 ° C. from the viewpoint of ensuring a sufficient liquid absorption capacity. It is more preferably 10 g / g or more, and even more preferably 25 g / g or more. Further, from the viewpoint of preventing the liquid from falling off due to swelling caused by absorption of the liquid, it is preferably 40 g / g or less, more preferably 35 g / g or less, and further preferably 30 g / g or less. Specifically, the water-absorbent polymer (A) is preferably 5 g / g or more and 40 g / g or less, more preferably 10 g / g or more and 35 g / g or less, and 25 g / g or less at 25 ° C. It is more preferably 30 g / g or less.

The water absorption amount is measured according to JIS K 7223 (1996). Nylon woven cloth (sold by Sanriki Seisakusho, product name: nylon net, standard: 250 mesh) is cut into a rectangle with a width of 10 cm and a length of 40 cm, folded in half at the center in the longitudinal direction, and both ends are heat-sealed to a width of 10 cm. (Inner size 9 cm), make a nylon bag with a length of 20 cm. Next, 1.00 g of the water-absorbent polymer, which is a measurement sample, is precisely weighed and put into the bottom of the produced nylon bag so as to be uniform. Next, the nylon bag containing the sample is immersed in physiological saline (0.9 mass% sodium chloride aqueous solution) whose temperature is adjusted to 25 ° C. Then, one hour after the start of immersion, the nylon bag is taken out of the physiological saline solution, hung vertically for one hour to drain water, and then dehydrated using a centrifugal dehydrator (manufactured by Kokusan Co., Ltd., model H-130C special type). The dehydration condition is 143 G (800 rpm) for 10 minutes. After dehydration, the mass of the sample is measured, and the target water absorption amount is calculated according to the following formula.
Water absorption (g / g) = (a'-bc) / c
In the above formula, a'is the total mass (g) of the sample and the nylon bag after centrifugal dehydration, b is the mass (g) of the nylon bag before water absorption (during drying), and c is the mass of the sample before water absorption (during drying). Represents mass (g).
The measurement is performed 5 times (n = 5), the values at each of the upper and lower points are deleted, and the average value of the remaining 3 points is used as the measured value. The measurement is performed at 23 ± 2 ° C. and 50 ± 5% humidity, and the sample is stored in the same environment for 24 hours or more before the measurement.

The surface treatment composition of the present invention contains (A) a polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film, in addition to the water-absorbent polymer (A). The polymer (B) is a polymer other than the water-absorbent polymer (A). The "polymer soluble in a volatile solvent" is when 100 g of ethanol and 10 g of the polymer of (B) are mixed and stirred at 25 ° C. for 5 minutes at the operating temperature of the surface treatment composition of the present invention. , The undissolved polymer remaining in ethanol has a solubility of 1 g or less. Further, "having the ability to form a hydrophobic film" means that 0.5 g of a solution prepared by dissolving 1 g of the polymer (B) in 10 g of ethanol is dropped onto glass and allowed to stand at 25 ° C. for 30 minutes to form a film. It is a property that can form a film showing hydrophobicity when the operation is performed. Whether or not the formed film has hydrophobicity is judged by dropping 0.1 g of pure water onto the film and determining the contact angle between the water droplets of pure water observed from the side and the film is larger than 90 °. Can be done.

In particular, the polymer (B) preferably has a solubility in water of 70% by mass or less at 25 ° C., more preferably 60% by mass or less, and more preferably 30% by mass, from the viewpoint of maintaining water repellency. It is more preferably less than or equal to, and even more preferably 10% by mass or less. This solubility may be zero.

The polymer (B) has an action of adhering the water-absorbent polymer of (A) to the application area when the surface treatment composition of the present invention is applied to the application area of the object to be treated. From this point of view, the polymer (B) has a binding ability capable of adhering the water-absorbent polymer (A) to the surface of the object to be treated, in addition to being soluble in a volatile solvent as described above. It is preferable to have. As the polymer having such properties, it is preferable to use a polymer compound called a so-called binder in the field of polymer technology. Therefore, in the following description, the polymer (B) is also referred to as a "binder polymer".

In addition to the fact that the binder polymer (B) is preferably soluble in a volatile solvent composed of an organic solvent, the proportion of the water-insoluble component measured at 25 ° C. is 90% by mass with respect to the solubility in water. It is preferably 70% by mass or less, more preferably 50% by mass or less, still more preferably 30% by mass or less. The proportion of this water-insoluble component may be zero.

The proportion of the water-insoluble component is measured by the following method. That is, 10 g of the polymer (B) was mixed with 100 g of water at 25 ° C. for 20 minutes with stirring, filtered using a filter paper (No. 5c, 12 cm manufactured by Advantech), and then the substance remaining on the filter paper was removed at 40 ° C. The dry mass a3 (g) is measured, and a3 / 10 × 100 is defined as the ratio (%) of the water-insoluble component.

As the binder polymer (B), one that is soluble in the above-mentioned volatile solvent is preferably used. Examples of such a polymer include a copolymer derived from an ethylenically unsaturated monomer. Examples of the ethylenically unsaturated monomer include olefins such as ethylene and propylene, aromatic vinyl compounds such as styrene, acrylic compounds such as acrylic acid and methacrylic acid, and halogen vinyl compounds such as vinyl chloride. As the ethylenically unsaturated monomer, an acrylic compound selected from the group consisting of acrylic acid, acrylic acid salt, acrylic acid ester, acrylic acid amide, methacrylic acid, methacrylic acid salt, methacrylic acid ester and methacrylic acid amide. Is preferable from the viewpoint of solubility in a volatile solvent. The polymer (B) preferably has a structure derived from two or more of these ethylenically unsaturated monomers.

Another example of the binder polymer of (B) is a silicone copolymer. The silicone copolymer is a polymer compound having a main skeleton due to a siloxane bond, and has N-acylalkyleneimine, acrylic acid, a salt of acrylic acid, an acrylic acid ester, an acrylic acid amide, methacrylic acid, and methacrylic as copolymerizing components. A compound containing at least one of an acid salt, a methacrylic acid ester, and a methacrylic acid amide in a molecular chain. Silicone copolymers are roughly classified into two types: physically crosslinked products in which crosslink points are generated by physical interaction, and chemical crosslinked products in which crosslink points are linked by covalent bonds. In the present invention, it is preferable to use a physically crosslinked product. The reason for this is that the physically crosslinked product is more easily dissolved in a volatile solvent than the chemically crosslinked product.

Examples of the physically crosslinked silicone copolymer include poly (N-acylalkyleneimine) -modified silicone, sugar-modified silicone (Japanese Patent Laid-Open No. 63-139106), and polyglycerin-modified silicone (Japanese Patent Laid-Open No. 2004-339244). , Polyamino acid-modified silicone (Japanese Patent Laid-Open No. 2002-145724), silicone graft acrylate polymer (Japanese Patent Laid-Open No. 4-342513), silicone PEG block polymer (Japanese Patent Laid-Open No. 4-234307) and the like are exemplified. Of these, it is preferable to use poly (N-acylalkyleneimine) -modified silicone because of its high solubility in a volatile solvent.

The poly (N-acylalkyleneimine) -modified silicone described above has, for example, a segment of the formula poly (N-acylalkyleneimine) and a segment of an organopolysiloxane in the molecule, and the terminal of the segment of the organopolysiloxane. Alternatively, it is preferable that the poly (N-acylalkyleneimine) segment is bonded to at least one of the silicon atoms in the side chain via an alkylene group containing a heteroatom. The alkylene group containing a hetero atom present at at least one of the silicon atoms at the end or side chain of the segment of the organopolysiloxane has 2 to 20 carbon atoms containing 1 to 3 nitrogen atoms, oxygen atoms or sulfur atoms. Alkylene group of.

Specific examples of the preferred poly (N-acylalkyleneimine) -modified silicone include poly (N-formylethyleneimine) -modified silicone, poly (N-acetylethyleneimine) -modified silicone, and poly (N-propionylethyleneimine) -modified. Examples include silicone. Among them, poly (represented by the formula (2)) having a weight average molecular weight of about 20,000 to 200,000 and a proportion of poly (N-propionylethyleneimine) segment in the molecule of about 3 to 50% by mass. N-propionylethyleneimine) modified silicone (INCI name: Polysilicone-9; elastomer OS (trade name of Kao Corporation)) is preferable.

The volatile solvent (C) refers to a substance having a saturated vapor pressure of 3000 Pa or more under atmospheric pressure at the operating temperature of the surface treatment composition. Examples of the volatile solvent include water and an organic solvent, but it is preferable to use a solvent that is not absorbed by the water-absorbent polymer (A). From this point of view, it is advantageous that the volatile solvent is an organic solvent. Examples of volatile solvents composed of organic solvents include alcohols, esters, nitriles, ethers, hydrocarbons, ketones and the like. One of these volatile solvents can be used alone, or two or more of these volatile solvents can be used in combination. When two or more kinds of volatile solvents are used in combination, the saturated vapor pressure is the saturated vapor pressure of the volatile solvent having the lowest saturated vapor pressure among the plurality of volatile solvents used. Among these volatile solvents, water, alcohol, ether and LPG (mixture of propane and butane) are preferable from the viewpoint of achieving both solubility of the polymer and drying time, and the group consisting of water, ethanol, dimethyl ether and LPG. It is more preferable to use one selected or a combination of two or more.

When alcohol is used as the volatile solvent, it is preferable to use a monohydric or polyhydric aliphatic alcohol having 1 or more and 5 or less carbon atoms. In particular, it is preferable to use a monohydric alcohol having 1 or more and 3 or less carbon atoms, such as methanol, ethanol and propanol. When an ester is used as the volatile solvent, an ester of a monohydric or polyhydric fatty alcohol having 1 or more and 4 or less carbon atoms and a monovalent or polyvalent fatty acid having 1 or more and 4 or less carbon atoms. Is preferably used. In particular, it is preferable to use an ester of a monohydric aliphatic alcohol having 1 or more and 2 or less carbon atoms and a monovalent fatty acid having 1 or more and 3 or less carbon atoms, such as ethyl acetate and methyl propionate. When nitrile is used as the volatile solvent, it is preferable to use nitrile of an alkane having 2 or more and 3 or less carbon atoms, for example, acetonitrile.

A mixed solvent of an organic solvent and water can also be used as the volatile solvent. When the volatile solvent is a mixed solvent of an organic solvent and water, the mixing ratio of the organic solvent and water is the organic solvent with respect to 100 parts by mass of water from the viewpoint of achieving both the solubility of the polymer and the drying time. Is preferably 100 parts by mass or more and 4000 parts by mass or less, and more preferably 800 parts by mass or more and 2000 parts by mass or less of the organic solvent.

The surface treatment composition of the present invention contains the above-mentioned water-absorbent polymer (A) in an amount of 1% by mass or more, particularly 2% by mass or more, particularly 3% by mass or more. It is preferable from the viewpoint of enhancing the water absorption performance after the treatment with. Further, it is preferable that the content is 15% by mass or less, particularly 10% by mass or less, particularly 5% by mass or less, from the viewpoint of treatment efficiency on the surface treatment object and ejection property from the nozzle when sprayed. The surface treatment composition of the present invention preferably contains the water-absorbent polymer (A) in an amount of 1% by mass or more and 15% by mass or less, particularly 2% by mass or more and 10% by mass or less, and particularly preferably 3% by mass or more and 5% by mass or less. ..

When the composition for surface treatment of the present invention contains the binder polymer (B) described above in an amount of 0.1% by mass or more, particularly 0.2% by mass or more, particularly 0.3% by mass or more, the reversion of the liquid is suppressed. It is preferable from the viewpoint of Further, it is preferably contained in an amount of 20% by mass or less, particularly 10% by mass or less, particularly 1% by mass or less, from the viewpoint of suppressing water absorption inhibition. The surface treatment composition of the present invention contains the binder polymer (B) in an amount of 0.1% by mass or more and 20% by mass or less, particularly 0.2% by mass or more and 10% by mass or less, and particularly 0.3% by mass or more and 1% by mass or less. It is preferable to include the following.

In the surface treatment composition of the present invention, the ratio of the water-absorbent polymer (A) to the binder polymer (B) described above is [the mass of the water-absorbent polymer (A) / the binder polymer (B). In terms of the value of [mass], it is preferably 0.05 or more, particularly 0.1 or more, particularly 2 or more, from the viewpoint of water absorption. Further, the value of [mass of the water-absorbent polymer (A) / mass of the binder polymer (B)] is preferably 150 or less, particularly 100 or less, particularly 25 or less, from the viewpoint of suppressing the reversion of the liquid. .. Specifically, the value of [mass of (A) water-absorbent polymer / mass of (B) binder polymer] is 0.05 or more and 150 or less, particularly 0.1 or more and 100 or less, and particularly 2 or more and 25 or less. It is preferable to have.

The composition for surface treatment of the present invention may contain a volatile solvent capable of dissolving the binder polymer in addition to the water-absorbing polymer (A) and the binder polymer (B) described above. The volatile solvent is preferably contained in an amount sufficient to dissolve the entire amount of the water-absorbent polymer (A) and the binder polymer (B) contained in the surface treatment composition of the present invention. Generally speaking, with respect to a total of 100 parts by mass of the water-absorbent polymer (A) and the binder polymer (B), 400 parts by mass or more, particularly 900 parts by mass or more, particularly 1900 parts by mass or more of the volatile solvent It is preferably contained. As described above, one type of volatile solvent can be used alone, or two or more types can be used in combination.

The surface treatment composition of the present invention can impart liquid absorption retention and water repellency to the application site by applying the composition to the surface of the object to be treated, for example. Generally speaking, the absorption-retaining property and water repellency of a liquid are contradictory properties, but according to the present invention, the absorption-retaining property and water repellency of a liquid which are these contradictory properties are achieved at the same time. Therefore, when the surface treatment composition of the present invention is used, for example, as a urine absorbent, it is possible to effectively prevent reversion and exudation of urine once absorbed while absorbing and retaining urine. Similarly, when the surface treatment composition of the present invention is used as a sweat absorber, it is possible to effectively prevent the reversion and exudation of the once absorbed sweat while absorbing and retaining the sweat. Furthermore, when the surface treatment composition of the present invention is used as a blood absorbent, it is possible to effectively prevent reversion and exudation of once absorbed blood while absorbing and retaining blood. Regardless of the purpose of use, when clothing is particularly used as the object to be treated to which the surface treatment composition of the present invention is applied, the object of application is the worn article that directly contacts the excretory part of the wearer as the clothing. Then, a water-absorbent article can be easily produced from the worn article by a method having a step of applying the surface treatment composition of the present invention to a portion of the worn article that comes into direct contact with the excretory portion of the wearer. In short, the water-absorbent article can be easily produced by a method having a step of treating the surface of any member constituting the water-absorbent article by the surface-treating composition of the present invention. As described above, the surface treatment composition of the present invention is applied to various application objects to impart water absorption and water repellency to the application objects. Of course, the surface treatment composition of the present invention may be contained in an absorber of a general water-absorbent article. Common water-absorbent articles include, for example, adhesive plasters, disposable diapers, sweat pads, urine pads, sanitary napkins, panty liners, and pantyliner sheets.

The above description relates to the use of the surface treatment composition of the present invention for treating the surface of a fiber material, but the surface treatment composition of the present invention is to be treated. The thing is not limited to the fiber material. Examples of the object to be treated include porous materials such as sponges and foams, and hard surfaces such as metals, plastics and minerals. Therefore, according to the present invention, there is also provided a method for surface treating an object to be treated, which comprises a step of applying a surface treatment composition to the surface of the object to be treated. Further, according to the present invention, there is also provided a method for improving the water absorption of the surface of the object to be treated, which comprises a step of applying a surface treatment composition to the surface of the object to be treated to improve the water absorption of the surface.

Specific forms of the object to be treated include carpets, flooring, films with or without elasticity, sheets with or without elasticity, and tapes with or without elasticity, in addition to the above-mentioned water-absorbent articles. And so on.

The surface treatment composition of the present invention is applied to the object to be applied by various methods. For example, the surface treatment composition of the present invention can be applied to an object to be applied by spraying. Alternatively, the composition can be applied to the application object by immersing the application object in the surface treatment composition of the present invention. Further, the surface treatment composition of the present invention can be applied to an object to be applied by a method using a printing device such as a die coater, a slot coater or a gravure printing machine, or by using various coating devices such as a spraying device. What kind of application method should be adopted may be appropriately determined according to the properties of the surface treatment composition of the present invention, the shape of the object to be applied, and the like. When the surface treatment composition of the present invention is applied to an object, a volatile solvent is volatilized from the composition, and as a result, a film composed of the binder polymer (B) is formed. This film stably holds the water-absorbent polymer (A) on the object. In particular, when the object to be applied is a member having a network structure such as a surface sheet of a water-absorbent article, various cloths and non-woven fabric products, and a porous material such as a sponge, the mesh structure in the member. At least a part of it will be coated in a film shape. The mesh shape in the present invention is a structure having holes through which a substance can pass.

Regardless of the type of object to which the surface treatment composition of the present invention is applied, the amount to which the composition is applied is generally 0. It is preferably 1 g / m ² or more, more preferably 0.5 g / m ² or more, and even more preferably ^{1 g / m 2 or more.} From the viewpoint of convenience and cleaning of the treatment, it is preferably 20 g / ^{m 2} or less, further preferably 10 g / ^{m 2} or less, and still more preferably 5 g / ^{m 2} or less. Specifically, the amount of applying the object of surface treatment composition of the present invention is preferably 0.1 g / ^{m 2} or more 20 g / ^{m 2} or less, 0.5 g / ^{m 2} or more 10 g / ^{m 2} It is more preferably 1 g / m ² or more and 5 g / m ² or less.

When the surface treatment composition of the present invention is applied to an object to be applied such as clothing or a water-absorbent article by spraying, the composition is contained in a spray container, and the composition is applied to the object to be applied from the spray container. You can spray it. In this case, the surface treatment composition of the present invention preferably further contains a propellant. That is, a surface treatment product having a surface treatment composition of the present invention containing a propellant and a spray container containing the surface treatment composition may be used. As the propellant, those conventionally used for spray containers can be used without particular limitation. Examples of the propellant include LPG (mixture of propane and butane), dimethyl ether (DME), carbon dioxide gas, nitrogen gas, and a mixture thereof. Of these, LPG (mixture of propane and butane) and dimethyl ether (DME) are preferable. Alternatively, an alternative chlorofluorocarbon such as HFC-152a can be used. As for the amount of the propellant contained in the spray container, the ratio of the propellant to the total amount of the water-absorbent polymer (A) and the polymer (B) as the undiluted solution is preferably 40% by mass or more and 80% by mass or less. The amount is more preferably 45% by mass or more and 75% by mass or less, and further preferably 50% by mass or more and 70% by mass or less. Further, it is preferable to adjust the type and content of the propellant so that the pressure in the spray container becomes 0.15 to 0.55 MPa at 25 ° C.

As described above, the surface treatment composition of the present invention can be applied to various clothing items such as underwear, for example, which are in direct contact with the excretory part of the wearer. It can impart absorption retention and water repellency. In other words, the applicable area can be an absorber of a water-absorbent article. As described above, the surface treatment composition of the present invention can easily make clothing a water-absorbent article. The water-absorbent article thus obtained effectively prevents the liquid excreted from the wearer from seeping into outerwear (for example, trousers, slacks, pants, etc.), and effectively reverts the liquid. It will prevent it.

When the surface treatment composition of the present invention is applied to underwear, which is clothing that comes into direct contact with the user's skin, for example, the outer surface side of the underwear, that is, the surface side far from the user's skin and the inner surface side, That is, the composition can be applied to either or both of the surfaces close to the user's skin. In particular, it is preferable to apply the surface treatment composition of the present invention on the outer surface side of the underwear surface, that is, the surface side far from the user's skin, because the amount of liquid returned and the amount of liquid exuded are further reduced. Specifically, the liquid excreted on the inner surface side of the underwear permeates the cloth constituting the underwear and reaches the outer surface side of the underwear, and the outer surface side is contained in the surface treatment composition of the present invention. Since the water-absorbent polymer is attached, the liquid is absorbed by the water-absorbent polymer and the liquid is unlikely to revert. Further, the liquid that has reached the outer surface side of the underwear is hindered from further movement by the film formed by the binder polymer contained in the surface treatment composition of the present invention, and the liquid is less likely to seep out.

Regarding the above-described embodiment, the present invention further discloses the following composition for surface treatment.
<1>
Surface treatment containing (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. Composition for.

<2>
The water-absorbent polymer (A) is a polyurethane such as a copolymer containing saturated bismethylenediphenyldiisocyanate (SMDI) and a copolymer containing hexamethyldiisocyanate (HDI), a copolymer containing dimethylacrylamide (DMAA), and a polymer. The surface treatment composition according to <1>, which is selected from a triblock copolymer or a multi-block copolymer containing a segment having a hydrophilic portion.
<3>
The surface treatment composition according to <1> or <2>, which contains 1% by mass or more and 15% by mass or less of the water-absorbent polymer (A).
<4>
The surface treatment composition according to any one of <1> to <3>, wherein the polymer (B) is a copolymer derived from an ethylenically unsaturated monomer or a silicone copolymer.
<5>
When the polymer (B) is a mixture of 100 g of ethanol and 10 g of the polymer of (B) and stirred at 25 ° C. for 5 minutes, the mass of the undissolved polymer of (B) remaining in ethanol is 1 g. The composition for surface treatment according to any one of <1> to <4>, which has the following solubility.
<6>
The surface treatment composition according to any one of <1> to <5>, wherein the polymer (B) has a solubility in water of 70% by mass or less at 25 ° C.

<7>
The surface treatment composition according to any one of <1> to <6>, wherein the polymer (B) has a water-insoluble component ratio of 90% by mass or less measured at 25 ° C.
<8>
The composition for surface treatment according to any one of <1> to <7>, which contains the polymer (B) in an amount of 0.1% by mass or more and 20% by mass or less.
<9>
The ratio of the water-absorbent polymer of (A) to the polymer of (B) is 0.05 or more and 150 or less in terms of the value of [mass of water-absorbent polymer of (A) / mass of polymer of (B)]. The composition for surface treatment according to any one of <1> to <8>.
<10>
(C) The composition for surface treatment according to any one of <1> to <9>, which further contains (C) a volatile solvent.
<11>
The surface treatment composition according to <10>, wherein the volatile solvent (C) has a saturated vapor pressure of 3000 Pa or more under atmospheric pressure at the operating temperature of the surface treatment composition.
<12>
The volatile solvent of (C) is contained in 400 parts by mass or more with respect to a total of 100 parts by mass of the water-absorbent polymer of (A) and the polymer of (B). Composition for surface treatment.

<13>
The surface treatment composition according to any one of <1> to <12>, further comprising a propellant.
<14>
The surface treatment composition according to <13>, wherein the ratio of the propellant to the total amount of the water-absorbent polymer (A) and the polymer (B) is 40% by mass or more and 80% by mass or less.
<15>
The surface treatment composition according to any one of <1> to <14>, wherein the water-absorbent polymer (A) is made of polyurethane.
<16>
The surface treatment composition according to any one of <1> to <15>, which is used for treating the surface of a fiber material.
<17>
It is a method of manufacturing water-absorbent articles.
A method for producing a water-absorbent article, which comprises a step of treating the surface of any of the members constituting the water-absorbent article with the surface-treating composition according to any one of <1> to <16>.
<18>
The member is made of fiber material
The method for producing a water-absorbent article according to <17>, wherein the surface of the fiber material is treated.

<19>
A surface treatment product comprising the surface treatment composition according to any one of <1> to <12> containing a propellant and a spray container containing the surface treatment composition.
<20>
Surface treatment containing (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. A water-absorbent article in which the composition for use covers at least a part of the network structure in a film shape in a member having the network structure.
<21>
A method for surface-treating an object to be treated, which comprises a step of applying the surface-treating composition according to any one of <1> to <16> to the surface of the object to be treated.
<22>
The surface treatment method according to <21>, wherein the surface treatment composition is ^{applied in an amount of 0.1 g / m 2} or more and 20 g / m ^{2 or less.}
<23>
The surface of the object to be treated is subjected to the surface treatment composition according to any one of <1> to <16> to improve the water absorption of the surface. How to improve.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited to such examples. Prior to the description of the examples, Synthesis Example 1 will be described.

Synthesis Example 1: Synthesis of poly (N-acylalkyleneimine) -modified silicone (binder polymer) 6.5 parts of diethyl sulfate and 100.0 parts of 2-ethyl-2-oxazoline are dissolved in 200.0 parts of dehydrated ethyl acetate. Then, the mixture was heated and refluxed for 5 hours under a nitrogen atmosphere to obtain terminal-reactive poly (N-propionylethyleneimine). To this, 100.0 parts of a 50% ethyl acetate solution of side chain primary aminopropyl-modified polydimethylsiloxane (molecular weight 110,000; amine equivalent (g / mol) 4,840) was added all at once, and heated and refluxed for 10 hours. did. The reaction mixture was concentrated under reduced pressure, and a poly (N-propionylethyleneimine) dimethylsiloxane copolymer (segment (A) / segment (B) = 50/50) (hereinafter referred to as poly (N-acylalkyleneimine) modified silicone). Was obtained as a pale yellow rubbery solid. The polystyrene-equivalent weight average molecular weight of this product was 109000 (by gel permeation chromatography using chloroform as a developing solvent). Also, as a solvent by metalnography). In addition, as a result of neutralization titration with hydrochloric acid using methanol as a solvent, it was confirmed that no amino group remained. This polymer was soluble in 100 g of ethanol / water = 70/30 (mass ratio) in an amount of 10 g or more, and was insoluble in water.

[Example 1]
As a water-absorbent polymer soluble in a volatile solvent, "Aquacork TWB" (trade name: manufactured by Sumitomo Seika Chemical Co., Ltd .; ethanol / water: solubility in 90/10 of 5 g / 100 g or more) was used. As the binder polymer, the poly (N-propionylethyleneimine) -modified silicone obtained in Synthesis Example 1 was used. The ratio of both was 5 parts by mass of the water-absorbent polymer and 1 part by mass of the binder polymer. An ethanol / water mixed solvent (ethanol / water = 90/10% by weight) was used as the solvent. The amount of the solvent used was 943 parts by mass with respect to 100 parts by mass in total of the water-absorbent polymer and the binder polymer. DME was used as a propellant. The amount of the propellant used was 1554 parts by mass with respect to 100 parts by mass in total of the water-absorbent polymer and the binder polymer. These were mixed to prepare a composition for surface treatment, which was filled in a spray container.

A 10 cm square test piece was taken from a commercially available trunks made of 100% cotton and fixed along the vertical direction. A spray was sprayed from a position 20 cm away from the test piece, and the surface treatment composition was coated on one surface. The coating amount was 3.5 g / m ² . A film was formed by drying in an environment of 25 ° C. and 1 atm for 24 hours. This coating film covered at least a part of the network structure in the cloth of the test piece.

[Comparative Examples 1 to 3]
Comparative Example 1 is an example in which a film was formed without using a binder polymer in Example 1. Comparative Example 2 is an example in which a film was formed without using a water-absorbent polymer in Example 1. Comparative Example 3 is an example in which the test piece itself was subjected to the evaluation described below without forming a film.

[Evaluation]
For the test pieces of Example 1 and Comparative Examples 1 to 3, the exudation rate of the liquid, the water absorption rate of the liquid, the return rate of the liquid, and the water absorption time of one drop were measured by the following methods. These results are shown in Table 1.

[Liquid exudation rate, liquid water absorption rate and liquid return rate]
Kanakin was placed on a horizontal table, and the test pieces obtained in Examples and Comparative Examples were placed on the test pieces so that the coating film on the test pieces was on the bottom. Under this condition, 0.5 mL of a blue-colored physiological saline solution manufactured by Otsuka Pharmaceutical Co., Ltd. was added dropwise to the upper surface of the test piece. Immediately after the dropping, an acrylic plate larger than the area covering the dropped area was placed, and a pressure of 3 g / cm ² , which is a pressure corresponding to the mounting pressure, was applied for 30 seconds. Remove the acrylic plate, place a filter paper (No. 5c, 12 cm manufactured by Advantech Co., Ltd.) on the test piece, place the acrylic plate on it, and apply a pressure of 3 g / cm ² , which is the pressure equivalent to the mounting pressure, to 30. Added over seconds. The upper filter paper is for the skin of the user, the test piece is for underwear, and the kanakin is for outerwear (trousers).
Then, the weight was removed, the mass of kanakin was measured, and the change in mass was determined. This value is taken as the amount of liquid exudation. In addition, the mass of the test piece before and after dropping the physiological saline was measured, and the change in mass was determined. This value is taken as the amount of water absorbed by the liquid. Furthermore, the mass of the filter paper was measured to determine the change in mass. This value is taken as the amount of liquid return. The ratio of the liquid exudation amount, the liquid water absorption amount or the liquid return amount to the total value of the liquid exudation amount, the liquid water absorption amount and the liquid return amount is calculated as the liquid exudation rate (%) and the liquid water absorption rate. It was calculated as (%) and the liquid return rate (%), respectively.

[1 drop water absorption time]
In the same manner as the measurement of the amount of water absorbed by the liquid, place the kanakin on a horizontal table, and place the test pieces obtained in Examples and Comparative Examples on it so that the coating on the test piece is on the bottom. Placed. Under this condition, one drop (0.05 g) of a solution colored with physiological saline (manufactured by Otsuka Pharmaceutical Co., Ltd.) in blue No. 1 0.1% was added dropwise to the upper surface of the test piece. The time from immediately after the dropping to when the reflected light of the raw food on the treated surface of the sample disappears is measured. The measurement was taken as the average value of 3 times, and this value was taken as the water absorption time (second) for one drop.

As is clear from the results shown in Table 1, the coated test piece obtained in the example has a larger amount of water absorption, a smaller amount of liquid return and a smaller amount of liquid seepage than the comparative example. Since the drip water absorption time is long, it can be seen that both water absorption and water repellency are achieved, the reversion of the liquid is suppressed, and the object to be treated is waterproof. Therefore, the coated test piece obtained in the examples is useful as a water-absorbent article.

Claims (11)

A fiber containing (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. Composition for surface treatment of materials. The composition for surface treatment according to claim 1, wherein the polymer (B) is a copolymer derived from an ethylenically unsaturated monomer or a silicone copolymer. The surface treatment composition according to claim 1 or 2, further comprising (C) a volatile solvent. The surface treatment composition according to any one of claims 1 to 3, further comprising a propellant. The surface treatment composition according to claim 4, wherein the ratio of the propellant to the total amount of the water-absorbent polymer (A) and the polymer (B) is 40% by mass or more and 80% by mass or less. The surface treatment composition according to any one of claims 1 to 5, wherein the water-absorbent polymer (A) is made of polyurethane. It is a method of manufacturing water-absorbent articles.
A method for producing a water-absorbent article, which comprises a step of treating the surface of a member made of a fiber material, which constitutes the water-absorbent article by the surface-treating composition according to any one of claims 1 to 6. .. A surface treatment product for a fibrous material, comprising the surface treatment composition according to any one of claims 1 to 3 containing a propellant and a spray container containing the surface treatment composition. Surface treatment containing (A) a water-absorbent polymer that is soluble in a volatile solvent, and (B) a polymer other than the water-absorbent polymer that is soluble in a volatile solvent and has the ability to form a hydrophobic film. A water-absorbent article in which the composition for use covers at least a part of the network structure in a film shape in a member having the network structure. A method for surface-treating an object to be treated, which comprises a step of applying the surface-treating composition according to any one of claims 1 to 6 to the surface of the object to be treated made of a fiber material. The surface of the object to be treated, which comprises a step of applying the surface treatment composition according to any one of claims 1 to 6 to the surface of the object to be treated made of a fiber material to improve the water absorption of the surface. Method for improving water absorption.