N-VINYL LACTAM-BASED CROSSLINKED POLYMER, COSMETIC, ABSORBENT AGENT FOR INK AND ABSORBENT COMPOSITE

Abstract

The invention aims to provide an absorbent composite having an excellent absorption capacity for various liquids. The invention relates to an absorbent composite including: a nonionic crosslinked polymer; and an absorbent base material, the absorbent composite having a mass ratio of the nonionic crosslinked polymer to the absorbent base material (nonionic crosslinked polymer/absorbent base material) of 0.1 or more and less than 2.

Claims

1. An absorbent composite comprising: a nonionic crosslinked polymer; and an absorbent base material, the absorbent composite having a mass ratio of the nonionic crosslinked polymer to the absorbent base material (nonionic crosslinked polymer/absorbent base material) of 0.1 or more and less than 2.

2. The absorbent composite according to claim 1, wherein the nonionic crosslinked polymer comprises a structural unit derived from an amide monomer and/or a structural unit derived from a (poly)alkylene glycol monomer.

3. The absorbent composite according to claim 1, wherein the absorbent base material comprises a hydrophilic fiber.

4. The absorbent composite according to claim 3, wherein the hydrophilic fiber is at least one selected from the group consisting of cellulosic fibers, polyamide fibers, animal fibers, and hydrophobic fibers having a hydrophilic surface layer.

5. The absorbent composite according to claim 1, wherein the absorbent base material has a sheet shape or a bag shape.

6. A deodorant comprising the absorbent composite according to claim 1.

7. A deodorizer comprising the deodorant according to claim 6.

8. A method of using the deodorant according to claim 6, the deodorant being incorporated into a deodorizer.

9. A cosmetic comprising the absorbent composite according to claim 1.

10. A method of using the absorbent composite according to claim 1 as a cosmetic.

11. An ink absorber comprising the absorbent composite according to claim 1.

12. An absorbent material comprising the ink absorber according to claim 11.

13. An ink-absorbed body comprising the ink absorber according to claim 11 and ink absorbed by the ink absorber.

14. A printer comprising the ink absorber according to claim 11.

15. A method of using the ink absorber according to claim 11, the ink absorber being incorporated into a printer.

Description

EXAMPLE

[0444] The invention is described in more detail below with reference to, but not limited to, examples. Unless otherwise specified, part(s) means part(s) by weight and % means % by mass.

<Evaluation of Liquid Absorption Capacities of Absorbent Composite for Solvent (Including Deionized Water) and Solution>

[0445] An absorbent composite was weighed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure (W4 (g)) and put into a container and immersed in a solution (in the case of deionized water, it has a conductivity of 10 S/cm or lower) at room temperature (temperature: 232 C.) and atmospheric pressure for 24 hours. In the case of using liquid that is slowly absorbed, such as oil, the absorbent composite was immersed therein at 40 C. for 24 hours and then cooled for 10 minutes. Subsequently, the absorbent composite was taken out by pinching the end of the tea bag with tweezers, placed one face down on KIMTOWEL (Nippon Paper Crecia Co., Ltd.), and allowed to stand for five seconds. Then, the absorbent composite was placed the other face down on KIMTOWEL and allowed to stand for five seconds so that the liquid was removed. Then, the mass of the absorbent composite (W5 (g)) was weighed. The liquid absorption rate was determined according to the following equation as the liquid absorption capacity.

Liquid absorption rate (g/g)=W5 (g)/W4 (g)

[0446] The nonionic crosslinked polymer in the absorbent composite was evaluated in the following way.

<Evaluation of Liquid Absorption Capacities of Polymer for Solvent (Including Deionized Water) and Solution>

[0447] About 0.1 g of a crosslinked polymer was precisely weighed (mass: W7 (g)) and put into a 4 cm5 cm nonwoven fabric tea bag, and the tea bag was heat-sealed. These operations were performed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure. The tea bag was placed in a 50-mL (specified volume) glass screw tube and immersed in a solvent or a solution (in the case of deionized water, it has a conductivity of 10 S/cm or lower) for 24 hours at room temperature (temperature: 232 C.) and atmospheric pressure. In the case of using liquid that is slowly absorbed, such as oil, the tea bag was immersed therein at 40 C. for 24 hours and then cooled for 10 minutes. Subsequently, the tea bag was taken out by pinching the end of the tea bag with tweezers, placed one face down on KIMTOWEL (Nippon Paper Crecia Co., Ltd.), and allowed to stand for five seconds. Subsequently, the tea bag was placed the other face down on KIMTOWEL and allowed to stand for five seconds so that the liquid was removed. Then, the mass of the tea bag (W8 (g)) was measured. Separately, the same operations were performed without a crosslinked polymer. Then, the mass of the tea bag (W6 (g)) was measured as a blank. The liquid absorption rate was determined according to the following equation as the liquid absorption capacity.

Liquid absorption rate (g/g)(W8 (g)W6 (g))/W7 (g)

<Testing for Deodorizing Properties of Diacetyl>

[0448] A glass lidded Petri dish (inner diameter: 27 mm) was prepared, and 0.50 g of the crosslinked polymer was put therein. Separately, an empty Petri dish was prepared as a blank.

[0449] These Petri dishes were covered and completely enclosed in sampling bags with a stopcock (Tedlar bag, GL Sciences Inc., volume: 3 L, shape: AAK) by heat-sealing. The sampling bags were evacuated, and 2 L of nitrogen gas was introduced into each bag, followed by introducing 5 mL of diacetyl-containing nitrogen gas thereinto using a gas-tight syringe. The Petri dishes with a lid removed were allowed to stand for two hours in the respective bags. Then, a 100-mL portion of the gas was drawn three times from each bag with a gas sampler (Model: GV-100S, Gastec Corporation), and the reduction rates of diacetyl concentrations were compared using a gas detector tube (No. 92 for acetaldehyde, Gastec Corporation). The measured values were converted to diacetyl concentrations using a conversion scale described in the manual of the detector tube.

[0450] The reduction rates of diacetyl were calculated using the following equation.

Reduction rate (%)=(gas concentration of blankgas concentration of sample)(gas concentration of blank)100

<Testing for Deodorizing Properties for Acetic Acid>

[0451] A glass lidded Petri dish (inner diameter: 27 mm) was prepared, and 0.50 g of the crosslinked polymer was put therein. Separately, an empty Petri dish was prepared as a blank.

[0452] These Petri dishes were covered and completely enclosed in sampling bags with a stopcock (Tedlar bag, GL Sciences Inc., volume: 3 L, shape: AAK) by heat-sealing. The sampling bags were evacuated, and 2 L of nitrogen gas was introduced into each bag. Thereafter, 5 mL of acetic acid-containing air was introduced into each bag using a gas-tight syringe. The Petri dishes with a lid removed were allowed to stand for two hours in the respective bags. Then, a 100-mL portion of the gas was drawn once from each bag with a gas sampler (Model: GV-100S, Gastec Corporation), and the concentrations of acetic acid were measured using a gas detector tube (No. 81 for acetic acid, Gastec Corporation). The reduction rates were calculated based on the actual value measured with the detector tube.

[0453] The reduction rates of acetic acid were calculated using the following equation.

Reduction rate (%)=(gas concentration of blankgas concentration of sample)(gas concentration of blank)100

<Measurement of Aspect Ratio>

[0454] The aspect ratio was determined by measuring the major and minor axes of a cyclic N-vinyl lactam-based crosslinked polymer particle with an optical microscope and dividing the major axis by the minor axis. The aspect ratio was calculated by analyzing image data of a sample obtained from an optical microscope using particle image analysis system, Morphologi G3 (product of Malvern in Spectris Co., Ltd.). The aspect ratios of any 100 or more particles were measured, and the average value of the aspect ratios was determined. Further, in the particles sorted in ascending order of the aspect ratio, the aspect ratio of the particle at 10% by number of all particles, the aspect ratio of the particle at 50% by number of all particles, and the aspect ratio of the particle at 90% by number of all particles were calculated.

[0455] In addition to the above described system, the aspect ratio may be measured by analyzing image data of a sample obtained from an optical or electron microscope using image analyzing particle size distribution measurement software, Mac-view, ver. 4 (Mountech Co., Ltd.).

<Quantification of Residual Monomer (N-Vinyl Lactam-Based Monomer) and by-Product (Compound Represented by the Formula (3))>

[0456] A 110-mL screw tube was charged with about 1 g of a particulate crosslinked polymer (mass: W9 (g)) and about 100 g of deionized water (mass: W10 (g)) (conductivity: 10 S/cm or lower), which were precisely weighed. A stirrer bar was placed in the tube, and the tube was sealed. These operations were performed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure. Thereafter, the contents were stirred using a magnetic stirrer at room temperature (temperature: 232 C.) and atmospheric pressure for 16 hours or longer (rotation speed: 600 rpm). These operations extracted the residual monomer of the particulate crosslinked polymer (N-vinyl lactam-based monomer) and a by-product (compound represented by the formula (3)). The resulting extract solution was quantitatively analyzed by liquid chromatography under the following conditions.

Apparatus: NANOSPACE SI-2, Shiseido Company, Limited

Column: CAPCELLPAK C18 UG120 (20 C.), Shiseido Company, Limited

[0457] Eluent: Methanol for LC (Wako Pure Chemical Industries, Ltd.)/super pure water=1/24 (mass ratio) supplemented with 0.04 mass % of sodium 1-heptanesulfonate
Flow rate: 100 L/min

Content (ppm)=measured value (ppm)(W9 (g)+W10 (g))/W9 (g)

<Measurement of Extractable>

[0458] A 110-mL glass screw tube was charged with about 1 g of a particulate crosslinked polymer (mass: W11 (g)) and about 100 g of deionized water (mass: W12 (g)) (conductivity: 10 S/cm or lower), which were precisely weighed. A stirrer bar was placed in the tube, and the tube was sealed. These operations were performed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure. Thereafter, the contents were stirred using a magnetic stirrer at room temperature (temperature: 232 C.) and atmospheric pressure for 16 hours or longer (rotation speed: 600 rpm). The resulting mixture was filtered through a qualitative filter paper (Model: No. 2, Advantec). Thus, an extract solution of an extractable was obtained.

[0459] Next, about 10 g of the extract solution (mass: W14 (g)) was put into an aluminum cup (mass: W13 (g)) having an about 5 cm diameter bottom face. The solution was allowed to stand in a dryer having a constant temperature of 120 C. for two hours, and thereby dried. After the drying, the sum of the mass (W15 (g)) of the aluminum cup and the mass of the extractable was measured, and the amount of the extractable was determined using the following equation.

Amount of extractable (mass %)=((W15 (g)W13 (g))/(W14 (g)W11 (g)/W12 (g)))100

<Measurement of Average Particle Size>

[0460] The 50% cumulative value was determined as an average particle size using a dry particle size distribution analyzer (Model: Mastersizer 3000, dry system, product of Malvern in Spectris Co., Ltd.). The following describes the measurement conditions.

<Measurement Conditions>

[0461] Dry laser diffraction scattering method
Dispersion pressure: 1 bar
Particle refractive index: 1.52
Particle absorptivity: 0.01
Particle shape: Non-spherical
Medium name: Air
Measurement range: 0.1 to 3500 m

<Measurement of Viscosity>

[0462] A 50-mL glass screw tube was charged with 2.5 g of a particulate crosslinked polymer and 47.5 g of deionized water (conductivity: 10 S/cm or lower), which were precisely weighed. A stirrer bar was placed in the tube, and the tube was sealed. These operations were performed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure. Thereafter, the contents were stirred using a magnetic stirrer at room temperature (temperature: 232 C.) and atmospheric pressure for 16 hours to prepare a 5 mass % aqueous dispersion of the cyclic N-vinyl lactam-based crosslinked polymer. Subsequently, the temperature of the aqueous solution was set at 25 C., and the viscosity was measured using a B-type viscometer (BM type, Toki Sangyo Co., Ltd.) (Rotor No. 4, rotation speed: 30 rpm).

Production Example 1

[0463] A desktop kneader (Model: PNV-1H, Chuorika Co., Ltd.) was charged with 130.0 parts of N-vinylpyrrolidone (hereinafter, also referred to as VP, Nippon Shokubai Co., Ltd.), 0.52 parts (0.18 mol % relative to VP) of triallyl cyanurate (hereinafter, also referred to as CTA) as a crosslinking agent, and 304.6 parts of deionized water. Subsequently, the kneader was purged with nitrogen at 100 mL/min for 30 minutes. Then, nitrogen was introduced at 30 mL/min, and the temperature was increased to 56 C. After the temperature of the liquid was stabilized at 56 C., 1.96 parts (0.25 g per 1 mol of the sum of VP and CTA used) of a 15 mass % aqueous solution of 2,2-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (hereinafter, also referred to as VA-044) as an initiator was added to start polymerization. A gel formed by the polymerization reaction was aged at 90 C. for 60 minutes while it was pulverized with the rotating blade of the kneader to complete the polymerization. Subsequently, 65.0 parts of a 1 mass % aqueous solution of malonic acid was added over three minutes, followed by stirring at 90 C. for 60 minutes. In addition, 32.5 parts of a 2 mass % aqueous solution of diethanolamine was added over three minutes, followed by stirring for 30 minutes. The resulting gel was dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using JIS standard 250 m-mesh and 500 m-mesh sieves. The powder that passed through the 500 m-mesh sieve and left on the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (1) of the invention). The average particle size of the VP crosslinked polymer (1) was 448 m determined by the above-described method. The absorption capacities measured by the above-described method were as follows: the deionized water absorption capacity was 22 times, the ethanol absorption capacity was 21 times, the linoleic acid absorption capacity was 31 times, the ethylene glycol absorption capacity was 22 times, the propylene glycol absorption capacity was 25 times, the pigment BK ink absorption capacity was 22 times, the dye BK ink absorption capacity was 21 times, the dye ink C absorption capacity was 23 times, the dye Y absorption capacity was 20 times, and the dye M absorption capacity was 23 times. Only the linoleic acid was measured at 40 C., and the solutions other than the linoleic acid were measured at room temperature. BCI-351 (dyes BK, C, M, and Y) and BCI-350 (PGBK (pigment BK)) (Canon Inc.) were used as ink.

Production Example 2

[0464] The same steps as in Production Example 1 were performed from the start to aging at 90 C. for 60 minutes to complete the polymerization. The resulting gel was dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using a JIS standard 250 m-mesh sieve. The powder that passed through the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (2) of the invention). The average particle size of the VP crosslinked polymer (2) was 121 m determined by the above-described method.

Production Example 3

[0465] The same steps as in Production Example 1 were performed from the start to aging at 90 C. for 60 minutes to complete the polymerization. Subsequently, 65.0 parts of a 1 mass % aqueous solution of malonic acid was added over three minutes, followed by stirring at 90 C. for 60 minutes. The resulting gel was dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using a JIS standard 250 m-mesh sieve. The powder that passed through the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (3) of the invention). The average particle size of the VP crosslinked polymer (3) was 110 m determined by the above-described method.

Production Example 4

[0466] A desktop kneader (Model: PNV-5H, Chuorika Co., Ltd.) was charged with 1000.0 parts of VP, 15.0 parts (0.65 mol % relative to VP) of pentaerythritol triallyl ether (trade name: neoallyl P-30M, Daiso Co., Ltd., the pH was adjusted to 6 or higher using diethanolamine) as a crosslinkable monomer, and 2368.33 parts of deionized water. The kneader was purged with nitrogen at 400 mL/min for 40 minutes. Then, nitrogen was introduced at 30 mL/min, and the temperature was increased to 56 C. After the temperature of the liquid was stabilized at 56 C., 47.37 parts (0.78 g per 1 mol of the sum of VP and pentaerythritol triallyl ether used) of a 15 mass % aqueous solution of 2,2-azobis (2-methylpropionamidine) dihydrochloride (hereinafter, also referred to as V-50) as an initiator was added to start polymerization. A gel formed by the polymerization reaction was aged at 90 C. for 60 minutes while it was pulverized with the rotating blade of the kneader to complete the polymerization. Subsequently, 500.0 parts of a 1.4 mass % aqueous solution of malonic acid was added over three minutes, followed by stirring at 90 C. for 60 minutes. In addition, 250.0 parts of a 2.8 mass % aqueous solution of diethanolamine was added over three minutes, followed by stirring for 30 minutes. The resulting gel was dried at 120 C. for three hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used, eight stainless steel vats each having external dimensions of 20626740 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using JIS standard 250 m-mesh and 500 m-mesh sieves. The powder that passed through the 500 m-mesh sieve and left on the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (4) of the invention). The average particle size of the VP crosslinked polymer (4) was 393 m determined by the above-described method. The absorption capacities measured by the above-described method were as follows: the deionized water absorption capacity was 22 times, the ethanol absorption capacity was 19 times, the linoleic acid absorption capacity was 31 times, the ethylene glycol absorption capacity was 22 times, and the propylene glycol absorption capacity was 25 times. Only the linoleic acid was measured at 40 C., and the solutions other than the linoleic acid were measured at room temperature.

Production Example 5

[0467] The same steps as in Production Example 4 were performed from the start to aging at 90 C. for 60 minutes to complete the polymerization. The resulting gel was dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used, eight stainless steel vats each having external dimensions of 20626740 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using a JIS standard 250 m-mesh sieve. The powder that passed through the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (5) of the invention). The average particle size of the VP crosslinked polymer (5) was 93 m determined by the above-described method.

Production Example 6

[0468] The same steps as in Production Example 4 were performed from the start to aging at 90 C. for 60 minutes to complete the polymerization. Subsequently, 500.0 parts of a 1.4 mass % aqueous solution of malonic acid was added over three minutes, followed by stirring at 90 C. for 60 minutes. The resulting gel was dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, two stainless steel vats each having external dimensions of 23229750 H (mm) were used, eight stainless steel vats each having external dimensions of 20626740 H (mm) were used) to obtain a dried VP crosslinked polymer. Then, the crosslinked polymer was ground using a grinder and classified using a JIS standard 250 m-mesh sieve. The powder that passed through the 250 m-mesh sieve was obtained as a particulate VP crosslinked polymer (VP crosslinked polymer (6) of the invention). The average particle size of the VP crosslinked polymer (6) was 87 m determined by the above-described method.

Production Example 7

[0469] A 250-mL PP container was charged with 27 g of methoxypolyethylene glycol acrylate (NK ester AM-90G, Shin-Nakamura Chemical Co., Ltd., number of moles of EO added: 9 mol, hereinafter, also referred to as AM-90G), 3 g of 2-hydroxyethyl acrylate containing 0.2 mass % of ethylene glycol diacrylate (Nippon Shokubai Co., Ltd.) (hereinafter, also referred to as HEA) as an impurity, and 70 g of pure water. Subsequently, stirring of the contents was started with a magnetic stirrer, and the container was purged with nitrogen at 100 mL/min for 30 minutes. The temperature was then increased to 40 C. under stirring. After the temperature of the liquid was stabilized at 40 C., 0.1 g of a 20 mass % aqueous solution of V-50 as an initiator was added to start polymerization. A gel formed by the polymerization reaction was aged at 90 C. for 30 minutes to complete the polymerization. The gel was pulverized using a desktop kneader (Model: PNV-1H, Chuorika Co., Ltd.) and then dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, one stainless steel vat having external dimensions of 20626740 H (mm) was used) to obtain a PEG acrylate/HEA crosslinked polymer (polyethylene oxide crosslinked polymer (7)). The deionized water absorption capacity was 15 times and the ethanol absorption capacity was 6 times, which were determined by the above-described method at room temperature.

Comparative Production Example 1

[0470] A 250-mL polypropylene container was charged with 30.0 parts of acrylic acid (Nippon Shokubai Co., Ltd., 80 mass % aqueous solution) (hereinafter, also referred to as AA), 12.14 parts of sodium hydroxide (48 mass % aqueous solution), 0.021 parts (0.01 mol % relative to AA) of polyethylene glycol dimethacrylate (NK ester A-400, Shin-Nakamura Chemical Co., Ltd., number of moles of EO added: 9 mol) (hereinafter, also referred to as A-400) as a crosslinkable monomer, and 42.2 parts of deionized water (AA and sodium hydroxide were mixed before addition of A-400 and deionized water). Subsequently, stirring of the contents was started with a magnetic stirrer, and the container was purged with nitrogen at 100 mL/min for 30 minutes. Then, nitrogen was introduced at 30 mL/min, and 0.33 parts (0.12 g per 1 mol of the sum of AA and A-400 used) of a 15 mass % aqueous solution of sodium persulfate as an initiator and 0.04 parts of a 0.5 mass % aqueous solution of L-ascorbic acid was added to start polymerization under stirring. A gel formed by the polymerization reaction was aged at 90 C. for 30 minutes to complete the polymerization. The gel was pulverized using a desktop kneader (Model: PNV-1H, Chuorika Co., Ltd.) and then dried at 120 C. for two hours (precision constant temperature oven, Model: DF42, Yamato Scientific Co., Ltd., maximum opening degree, one stainless steel vat having external dimensions of 20626740 H (mm) was used) to obtain a dried AA-based crosslinked polymer (comparative crosslinked polymer (1)). The crosslinked polymer was ground using a grinder. Thus, a particulate comparative crosslinked polymer (1) was obtained. The average particle size of the comparative crosslinked polymer (1) was 52.1 m, determined by the above-described method. The absorption capacities measured by the above-described method were as follows: the ethanol absorption capacity was 1 time, the linoleic acid absorption capacity was 1 time, the ethylene glycol absorption capacity was 1 time, the propylene glycol absorption capacity was 1 time, the pigment BK ink absorption capacity was 20 times, the dye BK ink absorption capacity was 16 times, the dye ink C absorption capacity was 25 times, the dye Y absorption capacity was 22 times, and the dye M absorption capacity was 22 times. Only the linoleic acid was measured at 40 C., and the solutions other than the linoleic acid were measured at room temperature. BCI-351 (dyes BK, C, M, and Y) and BCI-350 (PGBK (pigment BK)) (Canon Inc.) were used as ink.

Example 1

[0471] A sheet-like absorbent composite (1) was prepared in the following way as Example 1 using the VP crosslinked polymer (5) obtained in Production Example 5.

[0472] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (5) in an amount of 0.05 g was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Separately, water was diffused on the other non-woven fabric (non-woven fabric B). The non-woven fabric B was placed on the non-woven fabric A on which the VP crosslinked polymer (5) was diffused, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite (1). The amount of the VP crosslinked polymer (5) deposited on the non-woven fabric was 6 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.1.

Example 2

[0473] A sheet-like absorbent composite (2) was prepared in the following way as Example 2 using the VP crosslinked polymer (6) obtained in Production Example 6.

[0474] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (6) in an amount of 0.3 g was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Separately, water was diffused on the other non-woven fabric (non-woven fabric B). The non-woven fabric B was placed on the non-woven fabric A on which the VP crosslinked polymer (6) was diffused, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 30 minutes to obtain a sheet-like absorbent composite (2). In the absorbent composite (2), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (6) deposited on the non-woven fabric was 54 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.4.

Example 3

[0475] A sheet-like absorbent composite (3) was prepared in the following way as Example 3 using the VP crosslinked polymer (3) obtained in Production Example 3.

[0476] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (3) in an amount of 0.5 g was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Subsequently, water was diffused with an atomizer on the VP crosslinked polymer. The other non-woven fabric (non-woven fabric B) was placed on the resulting non-woven fabric A, and they were press-bonded. Thereafter, the resulting specimen was press-bonded and dried with an iron to obtain a sheet-like absorbent composite (3). In the absorbent composite (3), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (3) deposited on the non-woven fabric was 90 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.7.

Example 4

[0477] A sheet-like absorbent composite (4) was prepared in the following way as Example 4 using the VP crosslinked polymer (2) obtained in Production Example 2.

[0478] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. A VP crosslinked polymer gel swollen with water (gel prepared by adding 2.7 g of ion-exchange water to 0.3 g of the VP crosslinked polymer (2)) was uniformly applied to one of the two non-woven fabrics (non-woven fabric A). Similarly to this, a VP crosslinked polymer gel swollen with water was applied to the other non-woven fabric (non-woven fabric B). Subsequently, the non-woven fabric A and the non-woven fabric B were stacked so that the gel-side faces thereof faced each other, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite (4). In the absorbent composite (4), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (2) deposited on the non-woven fabric was 110 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.9.

Example 5

[0479] A sheet-like absorbent composite (5) was prepared in the following way as Example 5 using the VP crosslinked polymer (2) obtained in Production Example 2.

[0480] Two pulp non-woven fabrics (Lylex paper waste, material: pulp) each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (2) in an amount of 0.5 g was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Separately, water was diffused on the other non-woven fabric (non-woven fabric B). The non-woven fabric B was placed on the non-woven fabric A on which the VP crosslinked polymer (2) was diffused, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite (5). In the absorbent composite (5), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (2) deposited on the non-woven fabric was 100 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 1.1.

Example 6

[0481] A sheet-like absorbent composite (6) was prepared in the following way as Example 6 using the VP crosslinked polymer (3) obtained in Production Example 3.

[0482] Two polyester non-woven fabrics each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (3) in an amount of 0.5 g was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Separately, water was diffused on the other non-woven fabric (non-woven fabric B). The non-woven fabric B was placed on the non-woven fabric A on which the VP crosslinked polymer (3) was diffused, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite (6). In the absorbent composite (6), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (3) deposited on the non-woven fabric was 78 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.6.

Example 7

[0483] A sheet-like absorbent composite (7) was prepared in the following way as Example 7 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0484] A synthetic rubber bonding agent (trade name: 3M Spray Adhesive 99, Sumitomo 3M Limited.) was used. The bonding agent contained as components 10% by weight of synthetic rubber such as styrene-butadiene rubber, 40% by weight of an organic solvent such as n-pentane, acetone, or toluene, and 50% by weight of gas (for spray use) such as LPG or dimethyl ether.

[0485] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The bonding agent was uniformly spray-diffused on one surface of one of the two non-woven fabrics (non-woven fabric A) so that 0.17 g of the synthetic rubber (solid content) was deposited, followed by uniform diffusion of 0.5 g of the VP crosslinked polymer (1) thereon. Separately, the bonding agent was uniformly spray-diffused on the other non-woven fabric (non-woven fabric B) so that 0.17 g of the synthetic rubber was deposited. The non-woven fabric B was placed on the non-woven fabric A, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 100 C. for 10 minutes to obtain a sheet-like absorbent composite (7). In the absorbent composite (7), a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (1) deposited on the non-woven fabric was 100 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.8.

Example 8

[0486] A sheet-like absorbent composite (8) was prepared in the following way as Example 8 using the VP crosslinked polymer (3) obtained in Production Example 3.

[0487] Four pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The VP crosslinked polymer (3) in an amount of 0.4 g (1.6 g in total) was uniformly sprayed on each of the four non-woven fabrics (non-woven fabrics A to D). Subsequently, water was sprayed with an atomizer on the VP crosslinked polymer. The fabrics were stacked so that the crosslinked polymer-side faces thereof faced each other, and they were press-bonded (the non-woven fabrics A and B were press-bonded and the non-woven fabric C and D were press-bonded). Thereafter, similarly, 0.4 g (0.8 g in total) of the VP crosslinked polymer (3) was uniformly sprayed on each of the two specimens, i.e. the specimen of the non-woven fabrics A and B bonded to each other and the specimen of the non-woven fabrics C and D bonded to each other. Subsequently, water was sprayed with an atomizer on the VP crosslinked polymer. The resulting two specimens were stacked to each other so that the crosslinked polymer-side faces thereof faced each other, and they were press-bonded (press-bonded to prepare a specimen of the non-woven fabrics A, B, C, and D arranged in the stated order). Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite (8). The absorbent composite (8) had a multilayer structure in which resin layers were formed between the four non-woven fabrics. The amount of the VP crosslinked polymer (3) deposited on the non-woven fabric was 428 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 1.7.

Comparative Example 1

[0488] A sheet-like absorbent composite was prepared in the following way as Comparative Example 1 using the comparative crosslinked polymer (1) obtained in Comparative Production Example 1.

[0489] Two pulp-polypropylene non-woven fabrics (TRUSCO nonwoven fabric roll waste, material: pulp-polypropylene) each with a size of 100 mm50 mm were prepared. The comparative crosslinked polymer (1) in an amount of 0.5 g (particles having a particle size of 250 m or smaller obtained by classification) was uniformly diffused on one of the two non-woven fabrics (non-woven fabric A). Separately, water was diffused on the other non-woven fabric (non-woven fabric B). The non-woven fabric B was placed on the non-woven fabric A on which the comparative crosslinked polymer (1) was diffused, and they were press-bonded. Thereafter, the resulting specimen was dried with a dryer at 150 C. for 60 minutes to obtain a sheet-like absorbent composite. In the absorbent composite, a resin layer was formed between the two non-woven fabrics. The amount of the VP crosslinked polymer (1) deposited on the non-woven fabric was 78 g/m.sup.2, and the ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.6.

Example 9

[0490] A bag-like absorbent composite (9) was prepared in the following way as Example 9 using the VP crosslinked polymer (4) obtained in Production Example 4.

[0491] A bag-like product with a size of 40 mm50 mm was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was placed in the bag. The last one side was heat-sealed. Thus, a bag-like absorbent composite (9) was obtained. The absorbent composite (9) hardly scattered the VP crosslinked polymer (4) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 2.5.

Example 10

[0492] A bag-like absorbent composite (10) was prepared in the following way as Example 10 using the VP crosslinked polymer (4) obtained in Production Example 4.

[0493] A bag-like product with a size of 40 mm50 mm was formed using one-side heat sealable paper (Heat Pac MW, Nippon Paper Papylia Co., Ltd., basis weight: 50.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was placed in the bag. The last one side was heat-sealed. Thus, a bag-like absorbent composite (10) was obtained. The absorbent composite (10) hardly scattered the VP crosslinked polymer (4) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 1.0.

Example 11

[0494] A bag-like absorbent composite (11) was prepared in the following way as Example 11 using the VP crosslinked polymer (4) obtained in Production Example 4.

[0495] A bag-like product with a size of 40 mm50 mm was formed using non-woven fabric (ESCOTT, Unitika Ltd., material: cotton, PET, PP) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was placed in the bag. The last one side was heat-sealed. Thus, a bag-like absorbent composite (11) was obtained. The absorbent composite (11) hardly scattered the VP crosslinked polymer (4) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 1.0.

Example 12

[0496] A bag-like absorbent composite (12) was prepared in the following way as Example 12 using the VP crosslinked polymer (4) obtained in Production Example 4.

[0497] A bag-like product with a size of 40 mm50 mm was formed using non-woven fabric (Daiwabo Polytec Co, Ltd., material: rayon) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.2 g of the VP crosslinked polymer (4) was placed in the bag. The last one side was heat-sealed. Thus, a bag-like absorbent composite (12) was obtained. The absorbent composite (12) hardly scattered the VP crosslinked polymer (4) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 1.4.

Example 13

[0498] A bag-like absorbent composite (13) was prepared in the following way as Example 13 using the VP crosslinked polymer (4) obtained in Production Example 4.

[0499] A bag-like product with a size of 50 mm80 mm was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.8 g of the VP crosslinked polymer (4) was placed in the bag. The last one side was heat-sealed. Thus, a bag-like absorbent composite (13) was obtained. The absorbent composite (13) hardly scattered the VP crosslinked polymer (4) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 4.8.

Example 14

[0500] A bag-like absorbent composite (14) was prepared in the following way as Example 14 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0501] A product partitioned to have two pockets was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2), and 0.3 g (0.6 g in total) of the VP crosslinked polymer (1) was placed in each pocket. The pockets were hermetically sealed with a heat sealer. Thus, a bag-like absorbent composite (14) with a size of 80 mm50 mm partitioned into two sections was obtained (the two sections each had a size of 40 mm50 mm). The absorbent composite (14) hardly scattered the VP crosslinked polymer (1) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 3.5.

Example 15

[0502] A bag-like absorbent composite (15) was prepared in the following way as Example 15 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0503] A product partitioned to have two pockets was formed using one-side heat sealable paper (Heat Pac MW, Nippon Paper Papylia Co., Ltd., basis weight: 50.0 g/m.sup.2), and 0.3 g (0.6 g in total) of the VP crosslinked polymer (1) was placed in each pocket. The pockets were hermetically sealed with a heat sealer. Thus, a bag-like absorbent composite (15) with a size of 80 mm50 mm partitioned into two sections was obtained (the two sections each had a size of 40 mm50 mm). The absorbent composite (15) hardly scattered the VP crosslinked polymer (1) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 1.5.

Example 16

[0504] A bag-like absorbent composite (16) was prepared in the following way as Example 16 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0505] A product partitioned to have two pockets was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2), and 0.15 g (0.6 g in total) of the VP crosslinked polymer (1) was placed in each pocket. The pockets were hermetically sealed with a heat sealer. Thus, a bag-like absorbent composite (16) with a size of 80 mm50 mm partitioned into four sections was obtained (the four sections each had a size of 40 mm25 mm). The absorbent composite (16) hardly scattered the VP crosslinked polymer (1) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 3.6.

Example 17

[0506] A bag-like absorbent composite (17) was prepared in the following way as Example 17 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0507] A bag-like product with a size of 44 mm52 mm was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.75 g of the VP crosslinked polymer (1) was placed in the bag. The last one side was heat-sealed. Thus, a tetrahedral (triangular pyramid) bag-like absorbent composite (17) was obtained. The absorbent composite (17) hardly scattered the VP crosslinked polymer (1) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 7.9.

Example 18

[0508] A bag-like absorbent composite (18) was prepared in the following way as Example 18 using the VP crosslinked polymer (1) obtained in Production Example 1.

[0509] A bag-like product with a size of 44 mm52 mm was formed using a one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 0.9 g of the VP crosslinked polymer (1) was placed in the bag. The last one side was heat-sealed. Thus, a tetrahedral (triangular pyramid) bag-like absorbent composite (18) was obtained. The absorbent composite hardly scattered the VP crosslinked polymer (1) powder, and the amount thereof was only less than 10%. The ratio of VP crosslinked polymer/base material (mass ratio) was 9.2.

Example 19

[0510] A bag-like absorbent composite (19) was prepared in the following way as Example 19 using the polyethylene oxide crosslinked polymer (7) obtained in Production Example 7.

[0511] A bag-like product with a size of 44 mm52 mm was formed using one-side heat sealable paper (Heat-Ron GSP, Nippon Paper Papylia Co., Ltd., basis weight: 20.0 g/m.sup.2) by heat-sealing (sealing by thermal compression bonding) the three sides thereof. Then, 1.2 g of the polyethylene oxide crosslinked polymer (7) was placed in the bag. The last one side was heat-sealed. Thus, a tetrahedral (triangular pyramid) bag-like absorbent composite (19) was obtained. The absorbent composite (19) hardly scattered the polyethylene oxide crosslinked polymer (7), and the amount thereof was only less than 10%. The ratio of polyethylene oxide crosslinked polymer/base material (mass ratio) was 12.2.

<Absorption Capacities of Sheet-Like Absorbent Composite for Deionized Water, Ethanol, and Ethylene Glycol>

[0512] The following describes the evaluation method of the deionized water absorption capacities of the sheet-like absorbent composites obtained in Examples 1 to 8 and Comparative Example 1. The ethanol and ethylene glycol absorption capacities were determined according to the evaluation of liquid absorption capacities of absorbent composite for solvent (including deionized water) and solution at room temperature.

(Evaluation Method)

[0513] The sheet-like absorbent composite was cut into half to prepare a 50 mm50 mm piece, and the mass (W16 (g)) of the piece was precisely measured. The absorbent composite was placed in a Petri dish, and deionized water (conductivity: 10 S/cm or less) was thinly applied thereto (the upper portion of the absorbent composite was exposed to the air). The absorbent composite was allowed to stand at room temperature (temperature: 232 C.) and atmospheric pressure. After two hours, the absorbent composite was taken out by pinching the end thereof with tweezers, placed one face down on KIMTOWEL (Nippon Paper Crecia Co., Ltd.), and allowed to stand for five seconds. Then, the absorbent composite was placed the other face down on KIMTOWEL and allowed to stand for five seconds so that the liquid was removed. Then, the mass of the absorbent composite (W17 (g)) was weighed. The liquid absorption rate was determined according to the following equation as the liquid absorption capacity.

Liquid absorption rate (g/g)=W17 (g)/W16 (g)

[0514] Table 1 shows the results. The following results demonstrate that the sheet-like absorbent composite of the invention tends to have a low deionized water absorption capacity when it has a low mass ratio of crosslinked polymer/base material. In addition, comparison between Examples 3 and 7 demonstrates that a better liquid absorption capacity is obtained when no hydrophobic synthetic rubber bonding agent is used. The sheet-like absorbent composite having a multilayer structure obtained in Example 8 had a thickness of 6 mm after it was swollen with water. The absorbent composite obtained in Comparative Example 1 had a thickness of 10 mm or more after it was swollen with water, and peeling of the water-swollen crosslinked body from the sheet was observed.

TABLE-US-00001 TABLE 1 Absorbent composite Example Example Example Example Example Example Example Example Comparative 1 2 3 4 5 6 7 8 Example 1 Crosslinked polymer/ 0.1 0.4 0.7 0.9 1.1 0.6 0.8 1.7 0.6 Base material (mass ratio) Ion-exchange water 5.4 5.3 7.6 6.4 7.8 11.1 5.6 6.5 >100 absorption capapcity Ethanol absorption 5 5 7 6 7 11 5 6 2 capapcity Ethylene glycol 5 5 8 7 8 12 6 6 2 absorption capapcity

<Deionized Water, Ethanol, and Ethylene Glycol Absorption Capacities of Bag-Like Absorbent Composite>

[0515] The deionized water, ethanol, and ethylene glycol absorption capacities of the bag-like absorbent composites obtained in Examples 9 to 19 were determined according to the evaluation of liquid absorption capacities of absorbent composite for solvent (including deionized water) and solution at room temperature. Table 2 shows the results.

TABLE-US-00002 TABLE 2 Absorbent composite Example Example Example Example Example Example Example Example Example Example Example 9 10 11 12 13 14 15 16 17 18 19 Crosslinked polymer/ 2.5 1.0 1.0 1.4 4.8 3.5 1.5 3.6 7.9 9.2 12.2 Base material (mass ratio) Deionized water 17.2 12.6 14.6 16.9 21.2 19.7 15.2 18.8 24.0 21.4 15.0 absorption capapcity Ethanol absorption 16 11 14 16 21 19 14 18 23 21 14 capapcity Ethylene glycol 18 12 15 17 21 20 16 19 24 21 15 absorption capapcity

<Propylene Glycol and Ink Absorption Capacities of Sheet-Like Absorbent Composite>

[0516] The propylene glycol and ink absorption capacities of the sheet-like absorbent composites obtained in Examples 1 to 8 and Comparative Example 1 were evaluated. The following describes the evaluation.

(Evaluation Method)

[0517] The sheet-like absorbent composite was cut into half to prepare a 50 mm50 mm piece, and the piece was placed in a Petri dish. A solution (BCI-351 (dye BK), BCI-350 (PGBK (pigment BK)), Canon Inc., or propylene glycol) in an amount four times the weight of the absorbent composite was added to the Petri dish, and the Petri dish was covered with a lid. The absorbent composite was allowed to stand at room temperature (temperature: 232 C.) and atmospheric pressure for two hours. Thereafter, the inside of the Petri dish was observed to evaluate the presence or absence of residual liquid (fluid liquid). Table 3 shows the results. In Table 3, good means the absence of residual liquid, and bad means the presence of residual liquid. For ink (dye, pigment), the lid was removed from the Petri dish, water in the ink was evaporated with a dryer at 50 C., and the occurrence of discharge of liquid from the liquid absorbent gel was evaluated. Table 3 shows the results. In Table 3, good means the non-occurrence of discharge of liquid, and bad means the occurrence of discharge of liquid.

[0518] The following results demonstrate that the sheet-like absorbent composite of the invention is capable of absorbing and retaining glycol and ink.

TABLE-US-00003 TABLE 3 Absorbent composite Example Example Example Example Example Example Example Example Comparative 1 2 3 4 5 6 7 8 Example 1 Propylene glycol Good Good Good Good Good Good Good Good Bad absorbency Ink (dye) absorbency Good Good Good Good Good Good Good Good Good Discharge of ink Good Good Good Good Good Good Good Good Bad (dye) liquid Ink (pigment) Good Good Good Good Good Good Good Good Good absorbency Discharge of ink Good Good Good Good Good Good Good Good Good (pigment) liquid

<Propylene Glycol and Ink Absorption Capacities of Bag-Like Absorbent Composite>

[0519] The propylene glycol and ink absorption capacities of the bag-like absorbent composites obtained in Examples 9 to 19 were evaluated. The following describes the evaluation.

(Evaluation Method)

[0520] The bag-like absorbent composite was placed in a Petri dish. A solution (BCI-351 (dye BK), BCI-350 (PGBK (pigment BK)), Canon Inc., or propylene glycol) in an amount nine times the weight of the absorbent composite was added to the Petri dish, and the Petri dish was covered with a lid. The absorbent composite was allowed to stand at room temperature (temperature: 232 C.) and atmospheric pressure for eight hours. Thereafter, the inside of the Petri dish was observed to evaluate the presence or absence of residual liquid (fluid liquid). Table 4 shows the results. In Table 4, good means the absence of residual liquid, and bad means the presence of residual liquid. For ink (dye, pigment), the lid was removed from the Petri dish, water in the ink was evaporated with a dryer at 50 C., and the occurrence of discharge of liquid from the liquid absorbent gel was evaluated. Table 4 shows the results. In Table 4, good means the non-occurrence of discharge of liquid, and bad means the occurrence of discharge of liquid.

[0521] The following results demonstrate that the bag-like absorbent composite of the invention is capable of absorbing and retaining glycol or ink.

TABLE-US-00004 TABLE 4 Absorbent composite Example Example Example Example Example Example Example Example Example Example Example 9 10 11 12 13 14 15 16 17 18 19 Propylene glycol Good Good Good Good Good Good Good Good Good Good Good absorbency Ink (dye) absorbency Good Good Good Good Good Good Good Good Good Good Good Discharge of ink Good Good Good Good Good Good Good Good Good Good Good (dye) liquid Ink (pigment) Good Good Good Good Good Good Good Good Good Good Good absorbency Discharge of ink Good Good Good Good Good Good Good Good Good Good Good (pigment) liquid

<Evaluation of Water Diffusivity>

[0522] The water diffusivities of the sheet-like absorbent composites (3), (5), and (6) obtained in Examples 3, 5, and 6 were evaluated by the method described below. Separately, the same evaluation was performed on an absorbent base material alone (pulp-polypropylene non-woven fabric, pulp non-woven fabric, or polyester non-woven fabric, each with a size of 100 mm20 mm).

(Evaluation Method)

[0523] Each of the sheet-like absorbent composites with a size of 100 mm50 mm was cut into a size of 100 mm20 mm. The absorbent composites and the non-woven fabrics were hung so that the 100-mm length side was perpendicular to the ground. The absorbent composites were immersed in colored water so that the length of 5 mm from the lower edge thereof was immersed therein, and allowed to stand at room temperature (temperature: 232 C.) and atmospheric pressure for 24 hours. Thereafter, the length of the portion colored with the colored water of each composite was measured.

[0524] Table 5 shows the results. Here, the upper limit of the length was 100 mm (10 cm). The following results demonstrate that a pulp-polypropylene non-woven fabric and a pulp non-woven fabric have a higher water diffusivity as an absorbent base material, and the absorbent composites (3) and (5) of the invention including such absorbent base materials with a high diffusivity have a higher diffusivity than the absorbent composite (6) including a polyester non-woven fabric.

TABLE-US-00005 TABLE 5 Length of colored portion (cm) Absorbent Absorbent Absorbent composite (3) composite (5) composite (6) in Example 3 in Example 5 in Example 6 Base material alone 10 6 1 Absorbent composite 10 10 4

<Evaluation of Liquid Absorption Speed>

[0525] The absorbent composites (3) and (14) obtained in Examples 3 and 14 and the absorbent composite obtained in Comparative Example 1 were subjected to the following evaluation. The same evaluation was performed on the crosslinked polymer alone (the VP crosslinked polymers (3) and (1) obtained in Production Examples 3 and 1 and the comparative crosslinked polymer (1)).

(Evaluation Method)

[0526] Each of the absorbent composites was placed in a Petri dish (diameter: 100 mm). Propylene glycol in an amount four times the weight of the absorbent composite was poured over the absorbent composite, and the period of time required for disappearance of the residual liquid (liquid absorption speed) was evaluated. For the absorbent composite obtained in Comparative Example 1, which did not absorb propylene glycol, water in an amount 20 times the weight of the absorbent composite was used instead of propylene glycol, and the period of time required for disappearance of the residual liquid (liquid absorption speed) was evaluated. The same evaluation was performed on the crosslinked polymer alone. Here, the crosslinked polymer was uniformly dispersed in the Petri dish. Table 6 shows the results.

[0527] The absorbent composites obtained in Examples 3 and 14 had a higher liquid absorption speed than the crosslinked polymer alone. In contrast, no difference was observed in liquid absorption speed between the comparative absorbent composite including the comparative crosslinked polymer (1) and the crosslinked polymer alone. These results demonstrate that the combination of the nonionic crosslinked polymer of the invention and the absorbent base material results in a particular synergistic effect that is not obtained from a prior art crosslinked polymer containing polyacrylic acid (salt) as a main component.

TABLE-US-00006 TABLE 6 Period of time required for disappearance of residual liquid (seconds) Absorbent Absorbent Absorbent composite (1) composite (3) composite (14) of Comparative of Example 3 of Example 14 Example 1 Crosslinked polymer 124 231 <10 alone Absorbent composite <10 19 <10

Example 20

[0528] A sheet-like absorbent composite (20) was prepared in the following way as Example 20 using the VP crosslinked polymer (2) obtained in Production Example 2.

[0529] First, 50 parts by weight of the VP crosslinked polymer (2) and 50 parts by weight of wood-pulverized pulp were mixed together in a dry manner with a mixer. Next, the resultant mixture was air-laid into a web (sheet-like fiber) with a size of 120 mm400 mm on a wire screen of 400 mesh (mesh size: 38 m) with a batch type air laying device. In addition, the web was pressed for five seconds under a pressure of 196.14 kPa. Thus, a sheet with a weight of about 0.047 g/m.sup.2 was obtained. Subsequently, the sheet was cut into a facial mask shape and placed between two heat-sealable nylon nonwoven fabrics with a facial mask shape. The edges of the nonwoven fabrics were bonded by thermal fusion to obtain a sheet-like absorbent composite (20). The ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.1.

[0530] The sheet-like absorbent composite (20) and a similarly formed facial mask free from the VP crosslinked polymer were immersed in a skin lotion shown in Table 7. They were applied to the face, and the effects thereof were examined. The result was that the sheet-like absorbent composite containing the VP crosslinked polymer was capable of retaining a moisturizing effect longer.

TABLE-US-00007 TABLE 7 Component Amount (weight %) Sorbitol 3.00 1,3-Butylene glycol 1.00 Glycerol 2.00 Citric acid 0.01 Citric acid Na 0.10 Arginine 0.10 Glycyrrhizin acid 2K 0.05 Ethanol 7.00 Antiseptic agent Appropriate quantity Perfume Trace Purified water Added up to 100 in total

Example 21

[0531] The same steps as in Example 20 were performed from the start to pressing of the web for five seconds under a pressure of 196.14 kPa to obtain a sheet. Subsequently, a liquid impermeable polypropylene sheet as a so-called back sheet (liquid impermeable sheet), the above sheet (cut into a size of 108 cm), and a cotton non-woven fabric as a front sheet (liquid permeable sheet) were bonded to each other in the stated order with a double-stick tape. Thus, a sheet-like absorbent composite (21) was obtained. The ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.1.

[0532] The liquid permeable sheet-side face of each of the sheet-like absorbent composite (21) and a similarly formed sheet free from the VP crosslinked polymer was applied to an underarm, and the effects thereof were examined. The result was that the sheet-like absorbent composite containing the VP crosslinked polymer was capable of absorbing sebum and perspiration and had a higher ability to deodorize perspiration odor and body odor.

Example 22

[0533] The same steps as in Example 20 were performed from the start to pressing of the web for five seconds under a pressure of 196.14 kPa to obtain a sheet. Subsequently, the resultant sheet was placed between two pulp-polypropylene non-woven fabrics, and they were bonded to each other with a double-stick tape. Thus, a sheet-like absorbent composite (22) was obtained. The ratio of VP crosslinked polymer/non-woven fabric base material (mass ratio) was 0.2.

[0534] The sheet-like absorbent composite (22) had an excellent deodorizing ability and an excellent ability to wipe off dirt (such as oil component, sebum, and perspiration).

Example 23

[0535] A deodorant was prepared using the sheet-like absorbent composite (8) in the following way.

[0536] The sheet-like absorbent composite (8) was immersed in a commercially available fragrant liquid for one hour or more. Then, the sheet-like absorbent composite (8) was hung so that the long side thereof was perpendicular to the ground, immersed in the fragrant liquid so that the length of 1 cm from the lower edge thereof was immersed therein, and allowed to stand in a room. The result was that the sheet-like absorbent composite exerted fragrance for a long time and had excellent deodorant properties.

Comparative Example 2

[0537] Comparative Example 2 was performed as follows. The liquid absorption capacity of a non-woven fabric (non-woven fabric filter paper T-811, Advantec Toyo Kaisha, Ltd., thickness: 1.15 mm, mass: 110 g/m.sup.2, material: polyester) for an ink mixture was measured according to the following measurement method. As the result of the measurement, the liquid absorption capacity was 6 (g/g). Further, leakage of the liquid by application of pressure was observed.

[0538] The results confirm that the non-woven fabric has a low ink absorption capacity and causes leakage of the liquid by application of pressure, and thus the non-woven fabric seems not to strongly retain the liquid. This clearly demonstrates that the VP crosslinked polymer of the invention greatly contributes to the liquid absorption capacity (e.g. Example 6) of the absorbent sheet including the ink absorbing agent of the invention and a polyester non-woven fabric as a base material.

(Evaluation Method)

[0539] First, 3 g of an ink mixture (a solution prepared by mixing the same amounts of BCI-351 (BK, C, M, and Y) and BCI-350 (PGBK)) was placed in a 50-mL (specified volume) glass screw tube at room temperature. A non-woven fabric with a size of 4 cm5 cm was prepared, and the mass thereof was precisely weighed (mass: W18 (g)). The non-woven fabric was put into the screw tube containing the ink mixture. These operations were performed in a room at a temperature of 232 C., a relative humidity of 505%, and atmospheric pressure. The non-woven fabric was allowed to stand at room temperature (temperature: 232 C.) and atmospheric pressure. After 24 hours, the non-woven fabric was taken out by pinching the end thereof with tweezers, placed one face down on KIMTOWEL (Nippon Paper Crecia Co., Ltd.), and allowed to stand for five seconds. Then, the non-woven fabric was placed the other face down on KIMTOWEL and allowed to stand for five seconds so that the liquid was removed. Then, the mass of the non-woven fabric (W19 (g)) was weighed. The liquid absorption rate was determined according to the following equation as the liquid absorption capacity for various ink liquid mixtures.

Liquid absorption rate (g/g)=W19 (g)/W18 (g)