JP3712453B2 - Water-absorbing resin, water-absorbing resin composition and absorber - Google Patents

Water-absorbing resin, water-absorbing resin composition and absorber Download PDF

Info

Publication number
JP3712453B2
JP3712453B2 JP32330595A JP32330595A JP3712453B2 JP 3712453 B2 JP3712453 B2 JP 3712453B2 JP 32330595 A JP32330595 A JP 32330595A JP 32330595 A JP32330595 A JP 32330595A JP 3712453 B2 JP3712453 B2 JP 3712453B2
Authority
JP
Japan
Prior art keywords
water
absorbent resin
resin composition
weight
absorption
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP32330595A
Other languages
Japanese (ja)
Other versions
JPH09157534A (en
Inventor
克之 和田
邦彦 石▲崎▼
欣也 長砂
Original Assignee
株式会社日本触媒
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日本触媒 filed Critical 株式会社日本触媒
Priority to JP32330595A priority Critical patent/JP3712453B2/en
Priority claimed from TW085109593A external-priority patent/TW522024B/en
Priority claimed from KR1019960072413A external-priority patent/KR970032914A/en
Publication of JPH09157534A publication Critical patent/JPH09157534A/en
Application granted granted Critical
Publication of JP3712453B2 publication Critical patent/JP3712453B2/en
Anticipated expiration legal-status Critical
Application status is Expired - Fee Related legal-status Critical

Links

Images

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a water absorbent resin composition and an absorbent body. More specifically, the present invention provides a water absorbent resin composition that is particularly excellent in urine resistance and liquid diffusibility and has a reduced return of aqueous liquid under relatively high pressure (under pressure), and the water absorbent The present invention relates to an absorbent body comprising a functional resin composition at a relatively high concentration and suitably used for sanitary materials such as paper diapers (disposable diapers) and sanitary napkins.
[0002]
[Prior art]
  In recent years, a water-absorbing resin has been developed as a synthetic cross-linked polymer that gels by absorbing a large amount of water. The water-absorbent resin includes sanitary materials such as paper diapers, sanitary napkins, incontinence pads, simple toilets, wound protection materials, wound healing materials; excrement treatment agents for pets such as cat sand (articles for solidifying manure) It is used as a component. Water-absorbing resins are widely used not only as sanitary materials and excrement treatment agents, but also in the fields of agriculture and forestry, civil engineering, food, medical, and housing.
[0003]
  Examples of the water-absorbing resin include a cross-linked polyacrylic acid partially neutralized product, a hydrolyzate of starch-acrylonitrile graft polymer, a neutralized product of starch-acrylic acid graft polymer, and a vinyl acetate-acrylic acid ester copolymer. Saponified polymer, hydrolyzate of acrylonitrile copolymer or acrylamide copolymer or cross-linked product thereof, cross-linked product of carboxymethyl cellulose, cross-linked product of cationic monomer, cross-linked product of isobutylene-maleic anhydride copolymer, 2- Known are a crosslinked copolymer of acrylamide-2-methylpropanesulfonic acid and acrylic acid, a crosslinked polyethylene oxide, a crosslinked copolymer of methoxypolyethylene glycol and acrylic acid, and the like.
[0004]
  And recently, various properties have been imparted to these water-absorbing resins for the purpose of using them as sanitary materials such as paper diapers. The characteristics that the water-absorbent resin should have include excellent water absorption amount and water absorption speed when in contact with an aqueous liquid such as body fluid, gel strength, suction force for sucking water from a substrate containing an aqueous liquid, and the like. . And from the past, these water-absorbing properties have a plurality of physical properties in various specific ranges, and when used in sanitary materials such as paper diapers and sanitary napkins, they exhibit excellent water-absorbing properties. Various proposals have been made on resins or absorbent bodies and articles using the water-absorbing resin.
[0005]
  For example, a water-absorbing resin (US Pat. No. 4,654,039) that combines a specific gel volume, shear modulus, and extractable polymer content, a water-absorbing resin that specifies water absorption, water absorption speed, gel strength, and the water-absorbing resin Paper diapers and sanitary napkins using resin (JP 60-185550, JP 60-185551, JP 60-185804), specific water absorption rate, water absorption rate, gel stability Paper diapers using a water-absorbing resin having water content (Japanese Patent Laid-Open No. 60-185805), water-absorbing articles provided with a water-absorbing resin in which the amount of water absorption, suction power, and amount of water-soluble components are specified (Japanese Patent Laid-Open No. 21902), water-absorbing hygiene products containing water-absorbing resin with specified water absorption amount, water absorption amount under pressure, gel breaking strength (Japanese Patent Laid-Open No. 63-99861), water absorption amount and water absorption rate under pressure Paper diapers containing the specified water-absorbing resin (Japanese Patent Laid-Open No. 2-34167), the amount of water absorption under pressure and its particle size A water-absorbing agent containing a specified water-absorbing resin (European Patent No. 339,461), a water-absorbing agent containing a specific amount or more of a water-absorbing resin that specifies the water absorption rate and the amount of water under pressure in a short time (European Patent No. 443,627) ), A water-absorbing composite material (European Patent No. 532,002) containing a specific amount or more of a water-absorbing resin with a specified deformation and a sucking index during loading is known.
[0006]
  On the other hand, sanitary materials such as paper diapers and sanitary napkins have recently become highly functional and thin, and the amount of water-absorbing resin used per sanitary material, or mainly water-absorbing resin and hydrophilic fibers. The weight percent (hereinafter referred to as resin concentration) of the water-absorbent resin in the absorbent body consisting of the above tends to increase. In other words, by reducing the number of hydrophilic fibers with a small bulk specific gravity, increasing the water absorbent resin with excellent water absorption and large bulk specific gravity, the ratio of the water absorbent resin in the absorber is increased, thereby reducing the amount of water absorption. The sanitary material is made thinner without causing it to break.
[0007]
  In addition to the above-mentioned various characteristics, it has also been attempted to impart urine resistance to the water-absorbent resin mainly for use in sanitary materials such as paper diapers. That is, the above water-absorbent resin exhibits a high water absorption rate stably for a long time with respect to pure water or physiological saline. However, the water-absorbent resin swollen with urine exhibits a unique phenomenon that it deteriorates over time and collapses. Since the main use of the water-absorbent resin is sanitary materials and excrement treating agents, it is particularly desired to improve the urine resistance of the water-absorbent resin. Furthermore, when the resin concentration of the water-absorbent resin is high, the water-absorbing characteristics of sanitary materials and the like are greatly reduced due to urine deterioration of the water-absorbent resin. Therefore, the above urine resistance is a very important factor among the characteristics that the water absorbent resin should have.
[0008]
  As a means for improving the durability of the water-absorbent resin by preventing the deterioration of the urine and the like, the amount of the crosslinking agent used at the time of polymerization or after the polymerization is increased to produce a water-absorbent resin crosslinked at a high density. Good. However, in this case, the water absorption ratio of the water-absorbent resin is greatly reduced and disadvantageous in terms of cost.
[0009]
  Therefore, a method has been proposed in which a specific additive is added to the water-absorbent resin to impart urine resistance to the water-absorbent resin. Examples of the above method include a method of adding an oxygen-containing reducing inorganic salt (Japanese Patent Laid-Open No. 63-118375, US Pat. No. 4,972,019, US Pat. No. 4,863,989), a method of adding an antioxidant ( JP-A 63-127754), a method of adding an oxidizing agent (JP-A 63-153060), a method of adding a sulfur-containing reducing agent (JP-A 63-272349), a water-soluble phosphorus system A method of adding a compound (Japanese Patent Laid-Open No. 64-33158), a method of adding a specific fine titania (Japanese Patent Laid-Open No. 6-306202), a method of adding a specific fine titania and sulfite (Japanese Patent Laid-Open No. 7-53884), a method of adding alkoxy titanium (JP-A-7-62252), a method of adding an oxalic acid compound (JP-A 7-113048), and the like are known.
[0010]
  In addition, a method of imparting urine resistance to a water-absorbent resin by using a specific compound during polymerization has also been proposed. Examples of the above-described method include a method of polymerizing in the presence of a specific amount of a chain transfer agent and a specific amount of a crosslinking agent (Japanese Patent Laid-Open Nos. 2-255804, 3-179008, and European Patent No. 0372981). And a method of polymerizing in the presence of a water-soluble phosphoric acid compound (JP-A-5-97929) and the like are known.
[0011]
[Problems to be solved by the invention]
  However, the present inventors have found that the conventional water-absorbent resin has the following problems. That is, (1) The liquid diffusibility is not sufficient, so liquid clogging is likely to occur during gel swelling, (2) the urine resistance is insufficient, and (3) the liquid permeability is improved, The return amount of the aqueous liquid increases. Therefore, it has been confirmed that these conventional water-absorbent resins may not endure use when the resin concentration is high due to these problems. In addition, it has been recognized that the problem (1) becomes more serious when a water-soluble compound is combined with a water-absorbent resin.
[0012]
  Regarding the problem (1), the inventors of the present application have made various studies in order to increase, for example, the resin concentration in the absorbent body and increase the water absorption amount of the sanitary material. As a result, in order to prevent inconvenience such as leakage of the aqueous liquid from the sanitary material when the resin concentration of the absorber is higher than conventional, the characteristics of the water absorbent resin, that is, the water absorption amount and the water absorption speed described above, It has been found that it is not sufficient to control properties such as gel strength and suction force. For example, in a water-absorbing resin that has attracted particular attention in recent years and has only a very large amount of water absorption under pressure, when the resin concentration is increased, the liquid diffusibility in the absorber is extremely lowered, and the absorber is an aqueous liquid. It takes a long time to absorb.
Therefore, it has been found that the problem (1) remarkably occurs when the resin concentration is increased.
[0013]
  That is, as a result of various investigations focusing on the water absorption characteristics of the absorber having a higher resin concentration than the conventional one, when a mixture of a conventional water absorbent resin and hydrophilic fibers is used as the absorber, the resin concentration is increased. When the resin concentration is low, a certain level of water absorption characteristics is exhibited, but when the resin concentration exceeds 40% by weight, the liquid diffusibility is drastically decreased and the water absorption amount per unit weight of the absorber is found to be reduced. Therefore, it has been found that the problem of (1) occurs remarkably when a mixture of a conventional water-absorbent resin and hydrophilic fibers is used as the absorber.
[0014]
  Furthermore, since the problem of (1) originates from liquid permeability and liquid diffusibility, adding a water-soluble compound to a conventional water-absorbing resin increases the viscosity of the aqueous liquid at the time of water absorption. Turned out to be more prominent. For example, when a fertilizer, a surfactant, a deodorant or the like is added to add a new function to the water absorbent resin, such a problem becomes more prominent. In some cases, an absorber (water absorbent resin composition) It has been found that the liquid permeability and liquid diffusibility of the liquid are extremely lowered.
[0015]
  Further, regarding the problem (2), the inventors of the present invention have found that the conventional water-absorbent resin is still insufficient in urine resistance, and in the absorbent body in which the resin concentration of the water-absorbent resin is high. We have found that the diffusivity is extremely reduced. That is, it has been confirmed that the conventional water-absorbent resin exhibits a certain degree of urine resistance, but its performance is still insufficient when the resin concentration is high. Furthermore, in the above conventional method of adding a specific additive to impart urine resistance to the water-absorbent resin, the operation is not simple and the effect is not completely perfect. In some cases, new problems such as cost, safety, and coloring due to addition may be derived.
[0016]
  Further, as a result of the study by the present inventors on the problem of (3), a water-absorbing resin excellent in diffusibility, i.e., a water-absorbing resin having a high diffusion absorption factor is excellent in liquid permeability. Furthermore, it has been found that the amount of return of the aqueous liquid under a relatively high pressure (under pressure) may increase. That is, in the case of a water-absorbing resin with an emphasis on liquid permeability, when it is combined with hydrophilic fibers and used in paper diapers or the like, the gap between the hydrophilic fibers or the swelling gel is increased due to the high liquid permeability of the water-absorbing resin. Water present in the gap is easy to return. For this reason, as a result, it turned out that there may be a difficulty in what is called a dry feeling.
[0017]
  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is particularly excellent in urine resistance and liquid diffusibility, and the return amount of an aqueous liquid under a relatively high pressure (under pressure). Reduced water-absorbent resin composition, and absorbent body comprising the water-absorbent resin composition at a relatively high concentration, for example, suitably used for sanitary materials such as paper diapers (disposable diapers) and sanitary napkins Is to provide.
[0018]
[Means for Solving the Problems]
  In order to achieve the above object, the inventors of the present application have made extensive studies on the water absorbent resin composition and the absorbent body. As a result, a water-absorbing resin composition comprising a combination of a water-absorbing resin having specific physical property values (water-absorbing characteristics) and a specific water-soluble compound (non-volatile water-soluble compound), that is, 20 g / cm.2A water-absorbing resin having a diffusion absorption rate of 25 g / g or more of a physiological saline solution (0.9% by weight sodium chloride aqueous solution) 60 minutes after the start of absorption under the load of a non-volatile water-soluble compound It has been found that the water-absorbent resin composition is particularly excellent in urine resistance and liquid diffusibility, and the return amount of the aqueous liquid under a relatively high pressure is reduced as compared with the conventional one. Further, the absorbent comprising the water absorbent resin composition can maintain the above water absorption characteristics even when the resin concentration of the water absorbent resin composition is high, and the weight per unit weight The inventors have found that the water absorption is excellent, and have completed the present invention.
[0019]
  In order to solve the above problems, the water-absorbent resin of the present invention comprises polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. , A powdery water-absorbing resin obtained by surface cross-linking, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And 70% by weight or more thereof has a particle diameter larger than 300 μm.
[0020]
  In order to solve the above problems, the water-absorbent resin of the present invention has an average particle diameter of the polyacrylic acid (salt) in the range of 200 μm to 600 μm, and the polyacrylic acid (salt) The ratio of particles having a particle diameter of less than 106 μm is 10% by weight or less.
[0021]
  That is, the water-absorbent resin of the present invention has an average particle size obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component in order to solve the above problems. A powdery water-absorbing resin obtained by surface cross-linking polyacrylic acid (salt) having a particle size of less than 106 μm within a range of 200 μm to 600 μm and having a particle size of less than 106 μm, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And 70% by weight or more thereof has a particle diameter larger than 300 μm.
[0022]
  In order to solve the above problems, the water-absorbent resin of the present invention has a solubility parameter of 12.5 that allows the polyacrylic acid (salt) to react with a carboxyl group of the polyacrylic acid (salt). (cal / cm Three ) 1/2 The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cm Three ) 1/2 It is characterized in that it is subjected to surface crosslinking by heat treatment in the presence of less than the second surface crosslinking agent.
[0023]
  That is, the water-absorbent resin of the present invention has an average particle size obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component in order to solve the above problems. Solubility in which polyacrylic acid (salt) having a particle diameter of less than 106 μm within a range of 200 μm to 600 μm and having a particle size of less than 106 μm can react with a carboxyl group of the polyacrylic acid (salt) The parameter is 12.5 (cal / cm Three ) 1/2 The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cm Three ) 1/2 A powdery water-absorbent resin that is surface-crosslinked by heat treatment in the presence of less than the second surface-crosslinking agent, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And 70% by weight or more thereof has a particle diameter larger than 300 μm.
[0024]
  Furthermore, the water-absorbent resin of the present invention is characterized in that the diffusion / absorption capacity is 30 g / g or more in order to solve the above problems.
[0025]
  Also,In order to solve the above problems, the water absorbent resin composition of the present inventionThe water-absorbent resin according to the present invention (that is,A powdery water-absorbing resin obtained by crosslinking the surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, And 20 g / cm2Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. InAnd 70% by weight or more of the particles have a particle size larger than 300 μm.Water absorbent resin)When,Monoethanolamine, triethylenetetramine, glycine, glycerin, propylene glycol, polyethylene Glycol, glycolic acid, malonic acid, sodium hydroxide, at least one selected from the group consisting of sodium carbonateContaining water-soluble compoundsI amIt is characterized by that.
[0026]
  Also,The water absorbent resin composition of the present invention is characterized by further including a water-insoluble powder in order to solve the above-mentioned problems..
[0027]
  Moreover, in order to solve the above-mentioned problem, the water-absorbent resin composition of the present inventionThe water-absorbent resin according to the present invention (that is,A powdery water-absorbing resin obtained by crosslinking the surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, And 20 g / cm2Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. InAnd 70% by weight or more of the particles have a particle size larger than 300 μm.Water absorbent resin)When,At least one selected from the group consisting of monoethanolamine, triethylenetetramine, glycine, glycerin, propylene glycol, polyethylene glycol, glycolic acid, malonic acid, sodium hydroxide, sodium carbonateContaining water-soluble compoundsMuA water-absorbent resin composition, 20 g / cm2Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The diffusion absorption index indicated by the value of is 1.5 g / g · min or more.
[0028]
  Also,In order to solve the above problems, the water-absorbing resin composition of the present invention containsMonoethanolamine, glycerin, propylene glycol, polyethylene glycolIt is characterized by being at least one alcohol selected from the group consisting of Moreover, in order to solve said subject, the water absorbing resin composition of this invention is characterized by the diffusion absorption factor of the said water absorbing resin being 30 g / g or more.
[0029]
  Furthermore, the water-absorbent resin composition of the present invention is a polyacrylic acid obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component in order to solve the above-mentioned problems. (Salt), a powdery water-absorbing resin obtained by surface cross-linking,Monoethanolamine, glycerin, propylene glycol, polyethylene glycolAt least one alcohol selected from the group consisting of and a water-insoluble powder.A water absorbent resin composition comprising:20 g / cm2Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The diffusion absorption index indicated by the value of is 1.5 g / g · min or more.
[0030]
  Also,In order to solve the above problems, the water absorbent resin composition of the present invention is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. The polyacrylic acid (salt) having an average particle diameter of 200 μm to 600 μm and a ratio of particles having a particle diameter of less than 106 μm is 10% by weight or less is surface-crosslinked.
[0031]
  Furthermore, in order to solve the above problems, the water-absorbent resin composition of the present invention polymerizes a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. The polyacrylic acid (salt) has a polyacrylic acid (salt) having an average particle diameter of 200 μm to 600 μm and a ratio of particles having a particle diameter of less than 106 μm of 10% by weight or less. The solubility parameter that can react with a carboxyl group is 12.5 (cal / cmThree)1/2The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cmThree)1/2It is characterized by being surface-crosslinked by heat treatment in the presence of less than the second surface-crosslinking agent.
[0032]
  Moreover, in order to solve said subject, the water absorbing resin composition of this invention is further characterized by including the polyamine compound whose weight average molecular weight is 5,000 or more.
[0033]
  the aboveAccording to the structure, a large amount of aqueous liquid can be quickly absorbed, and the water absorption is particularly excellent in urine resistance and liquid diffusibility, and the return amount of the aqueous liquid under a relatively high pressure is reduced compared to the conventional water absorption. A functional resin composition can be provided. a
[0034]
  In order to solve the above problems, the absorbent body of the present invention contains the above water absorbent resin composition and hydrophilic fibers, and the ratio of the water absorbent resin composition to the total amount of both is 40% by weight. % Or more.
[0035]
  According to said structure, the various water absorption characteristics with which a water absorbing resin composition is provided can be maintained, and the absorber excellent in the amount of water absorption per unit weight can be provided. Since the absorbent body contains the water-absorbent resin composition at a relatively high concentration, it is suitably used for sanitary materials such as paper diapers and sanitary napkins.
[0036]
  The present invention is described in detail below.
[0037]
  The diffusion absorption capacity in the present invention is to evaluate the water absorption amount of the water absorbent resin in consideration of the diffusion force of the aqueous liquid in a state where the basis weight of the water absorbent resin is high and the resin particles are in close contact with each other by external force. This is a new physical property value. The diffusion absorption factor is calculated from a measured value after a predetermined time, for example, 60 minutes after the start of absorption in measurement under a predetermined condition. The method for measuring the diffusion absorption factor will be described in detail in the following examples.
[0038]
  New characteristics of the water-absorbent resin can be evaluated by the above-described diffusion absorption ratio. That is, this diffusion absorption ratio allows the water-absorbent resin to diffuse the aqueous liquid uniformly and quickly in the resin layer direction (hereinafter referred to as the lateral direction), and to what extent the entire water-absorbent resin actually is. It is possible to evaluate whether the water absorption amount is provided. The lateral liquid diffusibility (liquid diffusibility and liquid transfer capacity) of the aqueous liquid is a particularly important factor in absorbing a large amount of the aqueous liquid. From the results of the evaluation, for example, an absorbent body mainly composed of a water-absorbent resin and hydrophilic fibers, in particular, the water-absorbent resin in an absorbent body in which the weight% of the water-absorbent resin (hereinafter referred to as resin concentration) is high. The water absorption behavior can also be easily predicted. The configuration of the absorber will be described later.
[0039]
  In the above-mentioned prior application, there are many documents that evaluate the amount of water absorption under pressure. However, the conventional evaluation of the water absorption amount is performed only in the direction orthogonal to the resin layer direction (hereinafter referred to as the longitudinal direction). For this reason, it is hardly evaluated how uniformly and quickly the aqueous liquid diffuses in the lateral direction. Therefore, from the result of the conventional evaluation, it is impossible to accurately predict the water absorption behavior of the absorbent body such as a paper diaper using an absorbent body having a high resin concentration.
[0040]
  In addition, when the absorbent having a high resin concentration, that is, the absorbent according to the present invention is used as a sanitary material such as a paper diaper or a sanitary napkin, the water absorbent resin has an excellent diffusion absorption factor. In addition, it is more preferable that the diffusion absorption index is excellent. The diffusion absorption index in the present invention is to evaluate the liquid diffusion rate when the water absorbent resin absorbs the aqueous liquid in a state where the basis weight of the water absorbent resin is high and the resin particles are in close contact with each other by external force. This is a new physical property value. The diffusion absorption index is calculated from the measured value of the maximum absorption rate when the water absorbent resin absorbs the aqueous liquid in the measurement under a predetermined condition. The method for measuring the diffusion absorption index will be described in detail in the examples below.
[0041]
  With the above diffusion absorption index, it is possible to evaluate how quickly the water-absorbent resin can absorb the aqueous liquid and how quickly and evenly diffuse in the lateral direction.
[0042]
  One of the methods for obtaining the water-absorbent resin according to the present invention is, for example, a specific method obtained by polymerizing a hydrophilic unsaturated monomer mainly composed of acrylic acid and / or acrylate (neutralized product). The water-absorbing resin precursor is treated in the presence of a specific surface cross-linking agent to surface cross-link (Japanese Patent Application No. 7-45012). The water-absorbent resin contains a hydrophilic polymer (described later) in an amount of 20% by weight or less as necessary, and contains acrylic acid and / or acrylate (hereinafter referred to as acrylic acid (salt)) as a main component. A polyacrylic acid (salt) crosslinked polymer obtained by surface cross-linking polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer is more preferable.
[0043]
  The polyacrylic acid (salt) crosslinked polymer preferably has 45 mol% to 90 mol% of acid groups in the polymer neutralized in order to improve water absorption characteristics, More preferably, 80 mol% is neutralized. The acid group is preferably neutralized with, for example, an alkali metal salt, an ammonium salt, an amine salt, or the like, and more preferably neutralized with an alkali metal salt.
[0044]
  Said hydrophilic unsaturated monomer may contain unsaturated monomers other than acrylic acid (salt) as needed. The unsaturated monomer other than acrylic acid (salt) is not particularly limited. Specifically, for example, methacrylic acid, maleic acid, vinyl sulfonic acid, styrene sulfonic acid, 2- (meth) Anionic unsaturated monomers such as acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid and salts thereof; acrylamide, methacrylamide, N-ethyl ( (Meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Methoxypolyethylene glycol (meth) acrylate Nonionic hydrophilic group-containing unsaturated monomers such as polyethylene glycol mono (meth) acrylate, vinylpyridine, N-vinylpyrrolidone, N-acryloylpiperidine, N-acryloylpyrrolidine; N, N-dimethylaminoethyl (meth) acrylate N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, and cationic unsaturated monoliths such as quaternary salts thereof Examples include a polymer. These other unsaturated monomers may be used alone or in combination of two or more. And when using these other unsaturated monomers, it is 30 mol% or less with respect to a hydrophilic unsaturated monomer, Preferably it should just be 10 mol% or less.
[0045]
  The water-absorbent resin precursor obtained by polymerizing a hydrophilic unsaturated monomer has a carboxyl group. When obtaining the water-absorbing resin precursor, it is desirable to introduce a crosslinked structure into the interior using an internal crosslinking agent. The internal crosslinking agent is not particularly limited as long as it is a compound having a plurality of polymerizable unsaturated groups and / or reactive groups in one molecule. That is, the internal cross-linking agent may be a compound having a plurality of substituents copolymerized and / or reacted with the hydrophilic unsaturated monomer in one molecule. The hydrophilic unsaturated monomer may be composed of a self-crosslinking type compound that forms a crosslinked structure without using an internal crosslinking agent.
[0046]
  Specific examples of the internal crosslinking agent include N, N′-methylenebis (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and trimethylolpropane tri (Meth) acrylate, trimethylolpropane di (meth) acrylate, glycerin tri (meth) acrylate, glycerin acrylate methacrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, poly (meth) allyloxyalkane, (poly) ethylene Recall diglycidyl ether, glycerol diglycidyl ether, ethylene glycol, polyethylene glycol, propylene glycol, glycerol, pentaerythritol, ethylenediamine, polyethyleneimine, and glycidyl (meth) acrylate and the like, but is not particularly limited. These internal crosslinking agents may be used alone or in combination of two or more. And among the above-exemplified internal cross-linking agents, by using an internal cross-linking agent having a plurality of polymerizable unsaturated groups in one molecule, it is possible to further improve the water absorption characteristics and the like of the resulting water-absorbent resin.
[0047]
  The amount of the internal cross-linking agent used is preferably in the range of 0.005 mol% to 3 mol%, more preferably in the range of 0.01 mol% to 1.5 mol%, relative to the hydrophilic unsaturated monomer. . When the amount of the internal cross-linking agent used is less than 0.005 mol% and more than 3 mol%, a water absorbent resin having desired water absorption characteristics may not be obtained.
[0048]
  In addition, when polymerizing a hydrophilic unsaturated monomer to obtain a water-absorbing resin precursor, the reaction system includes starch, starch derivatives, cellulose, cellulose derivatives, polyvinyl alcohol, polyacrylic acid (salt), A hydrophilic polymer such as a crosslinked polyacrylic acid (salt); a chain transfer agent such as hypophosphorous acid (salt); a water-soluble or water-dispersible surfactant may be added.
[0049]
  The polymerization method of the hydrophilic unsaturated monomer is not particularly limited, and for example, known methods such as aqueous solution polymerization, reverse phase suspension polymerization, bulk polymerization, and precipitation polymerization can be employed. Among these, from the viewpoint of easy control of the polymerization reaction and performance of the resulting water-absorbent resin, a method of polymerizing a hydrophilic unsaturated monomer in an aqueous solution, that is, aqueous solution polymerization and reverse phase suspension polymerization are preferable. . In addition, reaction conditions, such as reaction temperature and reaction time, should just be set suitably according to the kind etc. of a hydrophilic unsaturated monomer, and are not specifically limited.
[0050]
  At the start of polymerization, for example, radical polymerization of potassium persulfate, ammonium persulfate, sodium persulfate, t-butyl hydroperoxide, hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, etc. An agent or active energy rays such as ultraviolet rays and electron beams can be used. Moreover, when using an oxidizing radical polymerization initiator, you may perform redox polymerization using reducing agents, such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, L-ascorbic acid, together, for example. The amount of these polymerization initiators used is preferably in the range of 0.001 mol% to 2 mol%, and more preferably in the range of 0.01 mol% to 0.5 mol%. The polymerization initiator may be dissolved or dispersed in a solvent such as water.
[0051]
  The particle diameter of the water-absorbent resin precursor obtained by the above polymerization method is adjusted by an operation such as classification as necessary. The water-absorbing resin precursor may be granulated into a predetermined shape, and may have various shapes such as a spherical shape, a scale shape, an irregularly crushed shape, a fibrous shape, a granular shape, a rod shape, a substantially spherical shape, and a flat shape. May be. Further, the water-absorbent resin precursor may be primary particles or a granulated body of primary particles.
[0052]
  The water-absorbent resin excellent in diffusion absorption factor used in the present invention can be obtained by treating the water-absorbent resin precursor in the presence of a specific surface cross-linking agent and surface cross-linking. Specifically, the water-absorbent resin precursor is adjusted by an operation such as classification so that the average particle diameter is within a range of 200 μm to 600 μm and the ratio of particles having a particle diameter of less than 106 μm is 10% by weight or less. Then, the water-absorbing resin precursor may be heat-treated in the presence of a surface cross-linking agent (described later) formed by combining the first surface cross-linking agent and the second surface cross-linking agent (Japanese Patent Application No. 7-45012). ). In addition, when the average particle diameter of the water-absorbent resin precursor is out of the range of 200 μm to 600 μm, or when the ratio of particles having a particle diameter of less than 106 μm exceeds 10% by weight, the performance such as diffusion absorption factor is excellent. It may be difficult to obtain a water absorbent resin.
[0053]
  By treating the water-absorbing resin precursor in the presence of a specific surface cross-linking agent and surface cross-linking, the water-absorbing resin precursor, that is, the cross-linking density near the surface of the water-absorbing resin can be made higher than the inside. . Thereby, the water-absorbing resin according to the present invention, that is, the water-absorbing resin excellent in water-absorbing characteristics such as diffusion absorption capacity can be obtained.
[0054]
  The surface cross-linking agent is a mixture of compounds capable of reacting with the carboxyl group of the water-absorbent resin precursor, and is formed by combining a first surface cross-linking agent and a second surface cross-linking agent having different solubility parameters (SP values). The solubility parameter is a value generally used as a factor representing the polarity of a compound. In the present invention, the solubility parameter δ (cal / cm) of the solvent described in Polymer Handbook 3rd edition (published by WILEY INTERSCIENCE) pp. 527 to 539 with respect to the above solubility parameter.Three)1/2The value of is applied. As for the solubility parameter of the solvent not described on the above page, the Hoy cohesive energy constant described on page 525 is substituted into the Small formula described on page 524 of the polymer handbook. Apply the derived value.
[0055]
  The first surface cross-linking agent has a solubility parameter of 12.5 (cal / cm) that can react with the carboxyl group of the water-absorbent resin precursor.Three)1/2The above compounds are preferred, and 13.0 (cal / cmThree)1/2The above compounds are more preferable. Specific examples of the first surface crosslinking agent include ethylene glycol, propylene glycol, glycerin, pentaerythritol, sorbitol, ethylene carbonate (1,3-dioxolan-2-one), and propylene carbonate (4-methyl). -1,3-dioxolan-2-one) and the like, but are not limited to these compounds. These first surface cross-linking agents may be used alone or in admixture of two or more.
[0056]
  The second surface cross-linking agent has a solubility parameter of 12.5 (cal / cm that can react with the carboxyl group of the water-absorbent resin precursor.Three)1/2Less than 9.5 (cal / cmThree)1/2~ 12.0 (cal / cmThree)1/2A compound within the range is more preferred. Specific examples of the second surface crosslinking agent include, for example, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 1,4-butanediol, 1 , 5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, 2,5-hexanediol, trimethylolpropane, diethanolamine, triethanolamine, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol Polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl Ether, ethylenediamine, diethylenetriamine, triethylenetetramine, 2,4-tolylene diisocyanate, hexamethylene diisocyanate, 4,5-dimethyl-1,3-dioxolan-2-one, epichlorohydrin, epibromohydrin, etc. However, it is not limited to these compounds. These second surface cross-linking agents may be used alone or in combination of two or more.
[0057]
  In the present invention, as the surface cross-linking agent, one or two or more compounds selected from the group of the first surface cross-linking agents, and one or two or more compounds selected from the group of the second surface cross-linking agents. It is particularly preferable to use a mixture of these. When only the first surface cross-linking agent is used, or when only the second surface cross-linking agent is used, there is a possibility that a water-absorbing resin excellent in performance such as diffusion absorption capacity cannot be obtained.
[0058]
  The amount of the surface cross-linking agent used depends on the compounds used and combinations thereof, but the amount of the first surface cross-linking agent used is 0.01 parts by weight to 100 parts by weight of the solid content of the water absorbent resin precursor. The amount of the second surface cross-linking agent is preferably within the range of 5 parts by weight and the amount of the first surface cross-linking agent within the range of 0.001 to 1 part by weight, and the amount of the first surface cross-linking agent used is 0.1 to 2 parts by weight. More preferably, the amount of the second surface crosslinking agent is within the range of 0.005 to 0.5 parts by weight. By using the above surface cross-linking agent, the water-absorbing resin precursor, that is, the cross-linking density in the vicinity of the surface of the water-absorbing resin can be made higher than the inside. When the amount of the surface cross-linking agent exceeds the above range, it is not preferable because not only is it uneconomical, but also the amount of the surface cross-linking agent becomes excessive in forming an optimal cross-linking structure in the water-absorbent resin. In addition, when the amount of the surface cross-linking agent used is less than the above range, it is difficult to obtain the improvement effect in improving the performance such as the diffusion / absorption capacity in the water-absorbent resin.
[0059]
  When mixing the water absorbent resin precursor and the surface cross-linking agent, it is preferable to use water as a solvent. Although the amount of water used depends on the type and particle size of the water absorbent resin precursor, it is preferably more than 0 and less than 20 parts by weight with respect to 100 parts by weight of the solid content of the water absorbent resin precursor. More preferably within the range of 5 to 10 parts by weight.
[0060]
  Moreover, when mixing a water absorbing resin precursor and a surface crosslinking agent, you may use a hydrophilic organic solvent as a solvent as needed. Specific examples of the hydrophilic organic solvent include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and t-butyl alcohol; acetone and the like Ketones; ethers such as dioxane, tetrahydrofuran and alkoxy polyethylene glycol; amides such as N, N-dimethylformamide; sulfoxides such as dimethyl sulfoxide, and the like. The amount of the hydrophilic organic solvent used is preferably 20 parts by weight or less with respect to 100 parts by weight of the solid content of the water absorbent resin precursor, although it depends on the type and particle size of the water absorbent resin precursor. More preferably within the range of 10 to 10 parts by weight.
[0061]
  And when mixing a water absorbing resin precursor and a surface crosslinking agent, after dispersing a water absorbing resin precursor in said hydrophilic organic solvent, you may mix a surface crosslinking agent, for example. The mixing method is not particularly limited. Of various mixing methods, a method in which a surface cross-linking agent dissolved in water and / or a hydrophilic organic solvent as necessary is directly sprayed or dropped into the water-absorbing resin precursor and mixed is preferable. Moreover, when mixing using water, you may coexist fine particle-like powder insoluble in water, surfactant, etc.
[0062]
  The mixing device used when mixing the water-absorbent resin precursor and the surface cross-linking agent preferably has a large mixing force in order to mix both uniformly and reliably. Examples of the mixing apparatus include a cylindrical mixer, a double wall conical mixer, a V-shaped mixer, a ribbon mixer, a screw mixer, a fluidized-type furnace rotary desk mixer, and an airflow-type mixer. A machine, a double-arm kneader, an internal mixer, a pulverizing kneader, a rotary mixer, a screw extruder, and the like are suitable.
[0063]
  After mixing the water absorbent resin precursor and the surface cross-linking agent, heat treatment is performed to crosslink the vicinity of the surface of the water absorbent resin precursor. Although the processing temperature of the said heat processing is based also on the surface crosslinking agent to be used, 160 to 250 degreeC is preferable. When the treatment temperature is less than 160 ° C., a uniform cross-linked structure is not formed, and therefore a water-absorbing resin excellent in performance such as diffusion absorption capacity cannot be obtained. Moreover, since heat processing takes time, productivity falls. When the treatment temperature exceeds 250 ° C., the water-absorbent resin precursor is deteriorated, and therefore the performance of the water-absorbent resin is lowered, which is not preferable.
[0064]
  Said heat processing can be performed using a normal dryer or a heating furnace. Examples of the dryer include a grooved mixed dryer, a rotary dryer, a desk dryer, a fluidized bed dryer, an airflow dryer, and an infrared dryer.
[0065]
  The water-absorbent resin obtained by the above production method is 20 g / cm.2Under the above load, the diffusion absorption rate of physiological saline 60 minutes after the start of absorption is 25 g / g or more. The water absorbent resin is 20 g / cm.2More preferably, the diffusion absorption rate of physiological saline 30 minutes after the start of absorption under the load of 15 g / g or more. Furthermore, the water absorbent resin is 20 g / cm.2Under the load of, the diffusion absorption rate of physiological saline 20 minutes after the start of absorption is 15 g / g or more, and the diffusion absorption rate of physiological saline 60 minutes after the start of absorption is 30 g / g or more. More preferably.
[0066]
  And it is especially preferable that the water-absorbent resin is in a powder form, and 70% by weight or more thereof has a particle diameter larger than 300 μm. The water-absorbent resin tends to decrease urine resistance as the particle size decreases.
[0067]
  The water-absorbent resin composition according to the present invention includes the above water-absorbent resin and a specific water-soluble compound (non-volatile water-soluble compound). In the present invention, the non-volatile water-soluble compound is a compound (water-soluble compound) having a boiling point of 150 ° C. or higher at normal pressure and 1 g or more dissolved in 100 g of water at normal pressure, or at normal temperature. A compound (water-soluble compound) that is solid and dissolves 1 g or more in 100 g of water at room temperature at normal pressure. The non-volatile water-soluble compound is preferably a compound that is solid at room temperature or a compound having a boiling point of 200 ° C. or higher at normal pressure (water-soluble compound), and is a compound that dissolves 10 g or more at normal pressure in 100 g of water at normal temperature (water-soluble compound) ) Is more preferable, and a compound capable of dissolving 100 g or more (water-soluble compound) is more preferable.
[0068]
  Examples of the non-volatile water-soluble compound include an organic compound having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group and a salt thereof, an amide group, and an amino group, and a water-absorbing resin. Inorganic compounds exhibiting basicity can be mentioned. In the present invention, the inorganic compound that exhibits basicity with respect to the water-absorbent resin refers to a compound that exhibits a pH higher than that exhibited by the water-absorbent resin. The inorganic compound is more preferably a compound having a pH of 8.5 or more, further preferably a pH of 9 or more, and particularly preferably a compound having a pH of 10 to 14.
[0069]
  Among the above organic compounds, the organic compound having one or more hydroxyl groups in the molecule, that is, alcohol is not particularly limited as long as it is water-soluble. Specific examples of the alcohol include monohydric alcohols such as glycolic acid and methoxypolyethylene glycol; ethylene glycol, propylene glycol, glycerin, polyglycerin, pentaerythritol, sorbitol, diethylene glycol, triethylene glycol, tetraethylene glycol, Dipropylene glycol, tripropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, 2,5-hexanediol, Trimethylolpropane, diethanolamine, triethanolamine, polyethylene glycol, polyvinyl alcohol, oxyethylene-oxypropylene block copolymer, oxyethylene- Carboxymethyl propylene random copolymer, water-soluble polysaccharides such as water-soluble starch, glucose, fructose, polyhydric alcohols such as sucrose; amino alcohols such as monoethanolamine. Of these exemplified alcohols, polyhydric alcohols and amino alcohols are more preferred, and polyhydric alcohols are more preferred. By using at least one alcohol selected from the group consisting of polyhydric alcohols and amino alcohols, the urine resistance of the water-absorbent resin composition is further improved.
[0070]
  Among the polyhydric alcohols, trihydric or higher polyhydric alcohols such as glycerin, sorbitol, and sucrose are within a range in which a plurality of hydroxyl groups remain in the molecule and can maintain water solubility. Then, a part of hydroxyl groups of the polyhydric alcohol may be modified by etherification or esterification. Examples of the polyhydric alcohol thus modified include glycerin mono fatty acid ester, polyoxyethylene fatty acid ester, sucrose fatty acid ester, and the like.
[0071]
  The polyhydric alcohol and amino alcohol may be prepared in advance before mixing with the water-absorbent resin, or after mixing ethylene oxide or alkylene carbonate, which is a precursor of these alcohols, with the water-absorbent resin, The precursor may be converted into a polyhydric alcohol or amino alcohol. In addition, when shape | molding a water absorbing resin to granulation or a sheet form, you may use said polyhydric alcohol as a plasticizer and binder of a water absorbing resin. In addition, the polyhydric alcohol can impart functions such as plasticity and adhesion to a substrate such as hydrophilic fibers to the resulting water-absorbent resin composition, and is highly safe and colored. The incompatibility of the water-absorbent resin composition and the hydrophilic fiber can be remarkably improved without causing such disadvantages.
[0072]
  Among the organic compounds, the organic compound having one or more carboxyl groups in the molecule and a salt thereof, that is, a carboxylic acid or a salt thereof may be water-soluble and are not particularly limited. Specific examples of the carboxylic acid salt (carboxylate) include anisate, benzoate, formate, valerate, glyoxylate, glycolate, glycerin phosphate, and glutaric acid. Salt, chloroacetate, chloropropionate, cinnamate, succinate, acetate, tartrate, lactate, pyruvate, fumarate, propionate, 3-hydroxypropionate, maleic acid Salt, malonate, butyrate, isobutyrate, imidinoacetate, malate, citraconic acid, adipate, itaconic acid, crotonic acid, salicylate, gluconate, gallate, sorbic acid Salt, gluconate, p-oxybenzoate and the like can be mentioned. Of these exemplified carboxylates, polyvalent carboxylates are more preferred, divalent carboxylates are more preferred, and maleates and malonates are particularly preferred.
[0073]
  Among the above organic compounds, specific examples of water-soluble organic compounds having one or more amide groups in the molecule include urea. When the water absorbent resin is granulated or formed into a sheet shape, the above urea may be used as a binder for the water absorbent resin.
[0074]
  The said inorganic compound should just be water-soluble, and is not specifically limited. Examples of the inorganic compound include phosphate, diphosphate, tripolyphosphate, sulfate, hydrochloric acid, carbonate, bicarbonate, alkali metal hydroxide, sodium carbonate, sodium bicarbonate, sodium hydroxide, hydroxide Potassium etc. are mentioned. Of these exemplified inorganic compounds, at least one compound selected from the group consisting of phosphates, carbonates, bicarbonates, and alkali metal hydroxides is more preferred, and carbonates and bicarbonates are more preferred. By using carbonate and bicarbonate, urine resistance of the water-absorbent resin composition is further improved.
[0075]
  The amount of the non-volatile water-soluble compound used depends on the use of the water-absorbent resin composition, but is preferably in the range of 1 to 50% by weight with respect to the water-absorbent resin, and 2 to 45% by weight. Is more preferable, and the range of 5 to 40% by weight is more preferable. Thereby, while being able to improve the urine resistance of a water absorbing resin composition, the return amount of an aqueous liquid can be reduced. When the amount of the non-volatile water-soluble compound used is less than 1% by weight, it is difficult to improve urine resistance and it may be difficult to reduce the return amount of the aqueous liquid. Further, when the amount of the non-volatile water-soluble compound used is more than 50% by weight, the liquid permeability and liquid diffusibility are lowered, and a water absorbent resin composition having desired water absorption characteristics may not be obtained. There is.
[0076]
  Moreover, when using an inorganic compound with respect to the water-absorbent resin in which 50 mol% to 80 mol% of the carboxyl groups are neutralized, the neutralization rate after addition is 85 mol% or more of the carboxyl groups, Preferably, an inorganic compound corresponding to 90 mol% or more, more preferably 95 mol% or more, and even more preferably 98 mol% or more may be added. Thereby, the urine resistance of the water absorbent resin composition is further improved. In addition, the upper limit of the usage-amount of the inorganic compound with respect to a carboxyl group is about 150 mol%.
[0077]
  The said non-volatile water-soluble compound may be used independently and may use 2 or more types together. Moreover, as a non-volatile water-soluble compound, only an organic compound may be used, only an inorganic compound may be used, and both may be used together. The non-volatile water-soluble compound is most preferably a polyhydric alcohol.
[0078]
  When mixing the water-absorbent resin and the non-volatile water-soluble compound, water and / or a hydrophilic organic solvent can be used as a solvent, if necessary. Specific examples of the hydrophilic organic solvent include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and t-butyl alcohol; acetone and the like Ketones; ethers such as dioxane, tetrahydrofuran and alkoxy polyethylene glycol; amides such as N, N-dimethylformamide; sulfoxides such as dimethyl sulfoxide, and the like. The amount of the solvent used depends on the type and particle size of the water-absorbent resin, but is preferably 20 parts by weight or less with respect to 100 parts by weight of the water-absorbent resin, and is within the range of 0.1 to 10 parts by weight. More preferred. In addition, when mixing a water absorbing resin and a non-volatile water-soluble compound using a solvent, what is necessary is just to dry the obtained water absorbing resin composition by heating etc. as needed after mixing. The temperature for heating may be in the range of 40 ° C to 300 ° C, preferably in the range of 50 ° C to 200 ° C.
[0079]
  Examples of the mixing device used when mixing the water-absorbent resin and the non-volatile water-soluble compound include a cylindrical mixer, a screw mixer, a screw extruder, a turbulator, a nauter mixer, V A character mixer, a ribbon mixer, a double-arm kneader, a fluid mixer, an airflow mixer, a rotating disk mixer, a roll mixer, a rolling mixer, and the like are suitable. Further, the mixing speed may be high or low. In addition, when a non-volatile water-soluble compound is solid, it is preferable to use the said solvent.
[0080]
  The water-absorbing resin composition having the above-described structure can absorb a large amount of aqueous liquid quickly, and is particularly excellent in urine resistance, water absorption speed, water absorption amount and liquid diffusibility, as well as aqueous liquid under relatively high pressure. The amount of return is reduced compared to the conventional case.
[0081]
  Moreover, the water-absorbent resin composition according to the present invention may further contain a water-insoluble powder, if necessary. Examples of the water-insoluble powder include inorganic fine powder, organic fine powder, hydrophilic short fiber, and the like.
[0082]
  Specific examples of the inorganic fine powder include silicon dioxide, titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, talc, calcium phosphate, barium phosphate, silicic acid, silicate, clay, diatomaceous earth, zeolite, bentonite, and kaolin. , Hydrotalcite, activated clay and the like, but are not particularly limited. These inorganic fine powders may be used alone or in combination of two or more. Of these inorganic fine powders, amorphous silicon dioxide is particularly preferred, and the particle size thereof is preferably 1,000 μm or less, more preferably 100 μm or less, further preferably 50 μm or less, and particularly preferably 10 μm or less.
[0083]
  In the case of using a water-insoluble powder, the amount of the water-insoluble powder used is preferably in the range of 0.05 part by weight to 2 parts by weight with respect to 100 parts by weight of the water absorbent resin, More preferably within the range of 1 part by weight. By using the water-insoluble powder, the water-absorbent resin composition has 20 g / cm.2Under the above load, the diffusion absorption rate of physiological saline 60 minutes after the start of absorption is 25 g / g or more and the diffusion absorption index is 1.5 g / g · min or more. That is, urine resistance, liquid diffusibility, and diffusion absorption index are further improved. If the amount of water-insoluble powder used is less than 0.05 parts by weight, the diffusion absorption index may not be improved. On the other hand, even if the amount of water-insoluble powder used is more than 2 parts by weight, an effect commensurate with the amount added cannot be obtained, which is economically disadvantageous.
[0084]
  For example, when mixing the water-insoluble powder and the water-absorbing resin, a mixing device similar to the mixing device used when mixing the water-absorbing resin and the non-volatile water-soluble compound can be used. The mixing speed may be high or low. The water-insoluble powder is preferably mixed without using a solvent, that is, dry blending.
[0085]
  Moreover, the water absorbing resin composition concerning this invention may further contain the polyamine compound whose weight average molecular weight is 5,000 or more as needed. Since such a polyamine compound is an ionic crosslinkable compound having high ionic crosslinkability, it reacts with a functional group of the water absorbent resin to become a water insoluble compound. The polyamine compound is not particularly limited as long as it has at least one amino group selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group.
[0086]
  Examples of the polyamine compound include a homopolymer of a monoallylamine derivative,
Homopolymers of allylamine derivatives; copolymers of two or more monoallylamine derivatives; copolymers of two or more diallylamine derivatives; copolymers of monoallylamine derivatives and diallylamine derivatives; monoallylamine derivatives and / or diallylamine derivatives And a copolymer of a dialkyl diallylammonium salt;
A homopolymer of an unsaturated carboxylic acid derivative having a tertiary amino group (hereinafter referred to as an unsaturated carboxylic acid derivative a); a copolymer of two or more types of unsaturated carboxylic acid derivatives a; an unsaturated carboxylic acid derivative a and An unsaturated carboxylic acid derivative (hereinafter referred to as an unsaturated carboxylic acid derivative b) having, as a substituent, a quaternary ammonium salt and / or a dialkyldiallylammonium salt obtained by protonating and / or alkylating a tertiary amino group, A terpolymer of an unsaturated carboxylic acid derivative a, an unsaturated carboxylic acid derivative b, and a vinyl monomer copolymerizable with these unsaturated carboxylic acid derivatives a and b; An acid and an unsaturated monomer copolymerizable with an unsaturated carboxylic acid are copolymerized to obtain a copolymer, and then the carboxyl group of the copolymer is converted to an alkylene group. A polyalkyleneimine; a polyalkyleneimine / epihalohydrin resin; a polyalkylenepolyamine; a polymer of (2-methacryloyloxyethyl) ethyleneimine, (2-methacryloyloxyethyl) ethyleneimine, and (2 -Methacryloyloxyethyl) Copolymer of ethyleneimine and unsaturated monomer copolymerizable; Polyamide polyamine; Polyamidoamine / epihalohydrin resin; Mannich reaction modified product of polyacrylamide, Mannich reaction modified product of polymethacrylamide; Polyvinyl And an amine, a copolymer of vinylamine and an unsaturated monomer copolymerizable with vinylamine; a dicyandiamide / diethylenetriamine polycondensate; and the like.
[0087]
  Specific examples of the polyamine compound include polyallylamine, polydiallylamine, poly (N-alkylallylamine), poly (alkyldiallylamine), monoallylamine-diallylamine copolymer, and N-alkylallylamine-monoallylamine copolymer. Polymer, monoallylamine-dialkyldiallylammonium salt / copolymer, diallylamine-dialkyldiallylammonium salt / copolymer, polydimethylaminoethyl acrylate, polydiethylaminoethyl acrylate, polydimethylaminoethylacrylamide, linear polyethyleneimine, branched polyethylene Imine, polyethylene polyamine, polypropylene polyamine, polyamide polyamine, polyether polyamine, polyvinylamine, polyamide poly Ming epichlorohydrin resins, polyamidine, and the like. Moreover, an aminated modified product obtained by reacting polyacrylamide or polymethacrylamide with formaldehyde and diethylamine is also included. The polyamine compound may be completely neutralized or partially neutralized with an acidic compound.
[0088]
  The weight average molecular weight of the polyamine compound is 5,000 or more, and preferably in the range of 10,000 to 10,000,000. Polyamine compounds having a weight average molecular weight of less than 5,000 are not preferred because the diffusion absorption index of the resulting water-absorbent resin composition is not improved. And when using a polyamine compound, the usage-amount of this polyamine compound has the preferable inside of the range of 0.1 weight part-10 weight part with respect to 100 weight part of water absorbing resin.
[0089]
  For example, when mixing a polyamine compound and a water-absorbent resin, for example, after preparing a solution or dispersion by dissolving or dispersing the polyamine compound in water and / or a hydrophilic organic solvent, the solution or dispersion is used. A method of mixing by spraying or dropping the water-absorbent resin is preferable. And when mixing both, the mixing apparatus similar to the mixing apparatus used when mixing a water absorbing resin and a non-volatile water-soluble compound can be used. The mixing speed may be high or low.
[0090]
  The order of mixing the water-absorbent resin, the non-volatile water-soluble compound, the water-insoluble powder, and the polyamine compound is not particularly limited. Thereby, while being excellent in urine resistance and liquid diffusibility, the water-absorbent resin composition in which the return amount of the aqueous liquid under a relatively high pressure is reduced as compared with the conventional one is obtained.
[0091]
  The absorbent according to the present invention includes the water absorbent resin composition having the above-described configuration and hydrophilic fibers, and the ratio of the water absorbent resin composition to the total amount of both, that is, the resin concentration is It is 40% by weight or more. The resin concentration is more preferably 50% by weight or more, further preferably 60% by weight or more, and particularly preferably 70% by weight or more. The absorber can maintain water absorption characteristics even when the resin concentration of the water absorbent resin composition is high, and is excellent in water absorption per unit weight. In addition, the higher the resin concentration in the absorber, the more remarkable the water absorption characteristics of the absorber.
[0092]
  Examples of the structure of the absorber include a structure in which the water absorbent resin composition and the hydrophilic fiber are uniformly mixed, a structure in which the water absorbent resin composition is sandwiched between the hydrophilic fibers formed in layers, and the water absorbent resin composition And a hydrophilic fiber are uniformly mixed to form a layer, and the layered hydrophilic fiber is laminated thereon, and the water absorbent resin composition and the hydrophilic fiber are uniformly mixed to form a layer. The structure etc. which formed and pinched the water absorbing resin composition between this and the hydrophilic fiber formed in layers are mentioned. Also, a structure in which hydrophilic fibers are pre-formed into a sheet (for example, nonwoven fabric or paper), and then a water-absorbing resin composition is laminated and fixed on the sheet, and the water-absorbing resin composition is sandwiched between the sheets. And the like. Of the above-exemplified configurations, a configuration in which the water absorbent resin composition and the hydrophilic fiber are uniformly mixed is more preferable. In addition, the structure of an absorber is not limited to the structure of the said illustration. Moreover, the water-absorbent resin composition may be formed into a sheet after a predetermined amount of water is blended.
[0093]
  Examples of the hydrophilic fiber include cellulose fibers such as mechanical pulp, chemical pulp, semi-chemical pulp, and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. Among the above-exemplified fibers, cellulose fibers are preferable. The hydrophilic fiber may contain a synthetic fiber such as polyamide, polyester, or polyolefin. The hydrophilic fibers are not limited to the above-exemplified fibers. Further, the hydrophilic fiber may be formed into a sheet shape (for example, a nonwoven fabric or paper).
[0094]
  Moreover, when the ratio of the hydrophilic fiber in an absorber is comparatively small, you may adhere | attach an absorber, ie, hydrophilic fiber, using an adhesive binder. By adhering the hydrophilic fibers together, it is possible to increase the strength and shape retention of the absorbent body before and during use of the water absorbing agent.
[0095]
  Examples of the adhesive binder include heat-fusion fibers such as polyolefin fibers such as polyethylene, polypropylene, ethylene-propylene copolymer, and 1-butene-ethylene copolymer, and adhesive emulsions. These adhesive binders may be used alone or in combination of two or more. The weight ratio between the hydrophilic fiber and the adhesive binder is preferably within the range of 50/50 to 99/1, more preferably within the range of 70/30 to 95/5, and within the range of 80/20 to 95/5. Is more preferable.
[0096]
  Although the water-absorbent resin composition according to the present invention, that is, the absorber does not cause clogging of the aqueous liquid at the time of gel swelling, the cause of excellent performance such as diffusion absorption capacity and water absorption speed is not clear, The liquid diffusion and liquid transmission of the aqueous liquid in the absorbent body is performed by the capillary phenomenon of hydrophilic fibers in the conventional absorbent body, whereas the absorbent body composition is provided in the absorbent body according to the present invention. It is presumed that this is due to liquid diffusibility (liquid diffusion ability and liquid transmission ability).
[0097]
  Further, although the cause of the water-absorbing resin composition according to the present invention exhibiting excellent urine resistance is not clear, the cross-linking of the water-absorbing resin surface is more uniform and the cross-linking density is increased, In addition, it is presumed that the action of a compound such as a degrading enzyme that catalytically acts on urine deterioration is suppressed by mixing a specific non-volatile water-soluble compound.
[0098]
  Furthermore, the reason why the water-absorbent resin composition according to the present invention does not increase the return amount of the aqueous liquid even when the liquid permeability is improved is not clear, but the non-volatile water-soluble compound may cause a gap between the hydrophilic fibers. It is presumed that the reverse of water present in the gaps of the swollen gel is suppressed.
[0099]
  The absorbent body having the above structure can maintain various water absorption characteristics of the water absorbent resin composition and is excellent in water absorption per unit weight. Moreover, the absorber can maintain the above water absorption characteristics even after absorbing the aqueous liquid. Since the absorbent contains a water-absorbent resin composition at a relatively high concentration, for example, sanitary materials such as paper diapers, sanitary napkins, incontinence pads, simple toilets, wound protection materials, wound healing materials; It is suitably used as a constituent material for a feces excrement treating agent (article for solidifying manure) and the like. Since the absorbent body has excellent water absorption characteristics, for example, when used in a paper diaper, it is possible to prevent leakage of urine and to impart a so-called dry feeling. In addition, since the water-absorbent resin composition and the absorbent body can be combined with various water-soluble compounds such as fertilizers, deodorants, and surfactants, the fields of agriculture and forestry, civil engineering, food, and medical It can be widely used in the housing field.
[0100]
  And when using an absorber for a paper diaper, a sanitary napkin, etc., for example, what is necessary is just to sandwich an absorption layer containing an absorber with a sheet which has liquid permeability, and a sheet which has impermeableness. . In addition, the structure and manufacturing method of an absorption layer, manufacturing methods, such as a paper diaper and a sanitary napkin, are not specifically limited.
[0101]
  The liquid-permeable sheet (hereinafter referred to as a liquid-permeable sheet) is made of a material having a property of transmitting an aqueous liquid. Examples of the material of the liquid permeable sheet include nonwoven fabrics, woven fabrics, and porous synthetic resin films made of polyethylene, polypropylene, polyester, polyamide, and the like. The liquid-impermeable sheet (hereinafter referred to as a liquid-impermeable sheet) is made of a material having a property of not transmitting an aqueous liquid. Examples of the material of the liquid-impermeable sheet include synthetic resin films made of polyethylene, polypropylene, ethylene vinyl acetate, polyvinyl chloride, etc .; films made of composite materials of these synthetic resins and nonwoven fabrics; And a film made of a composite material. Note that the liquid-impermeable sheet may have a property of allowing vapor to pass therethrough.
[0102]
  As described above, the water-absorbent resin composition according to the present embodiment is a polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. Is a powdery water-absorbing resin obtained by surface cross-linking, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And a water-soluble compound having a boiling point of 150 ° C. or higher at normal pressure and 1 g or more of water-soluble compound dissolved in 100 g of water at normal pressure. An organic compound having at least one functional group selected from the group consisting of a group and a salt thereof, an amide group, and an amino group, and mineralization exhibiting a pH higher than that exhibited by the water absorbent resin Things, at least one compound selected from and at least 70 wt% of the water absorbent resin may be a structure having a larger particle size than 300 [mu] m.
[0103]
  Further, as described above, the water-absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component (polyacrylic acid ( Salt) is a powdery water-absorbing resin obtained by surface cross-linking, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And a water-soluble compound that is solid at room temperature and dissolves in an amount of 1 g or more in 100 g of water at ordinary temperature, and the water-soluble compound is a hydroxyl group, a carboxyl group and a salt thereof, an amide An organic compound having at least one functional group selected from the group consisting of a group and an amino group, and an inorganic compound exhibiting a pH higher than the pH exhibited by the water absorbent resin. At least one compound, and more than 70% by weight of the water absorbent resin may be a structure having a larger particle size than 300 [mu] m.
[0104]
  Further, as described above, the water absorbent resin composition according to the present embodiment may further include a water-insoluble powder. Further, as described above, the water-absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component (polyacrylic acid ( Salt) is a powdery water-absorbing resin obtained by surface cross-linking, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. Physiologically absorbed 60 minutes after the start of absorption A water-absorbing resin having a diffusion absorption ratio of 25 g / g or more obtained by dividing the weight of a saline solution (0.9 wt% sodium chloride aqueous solution) by the weight of the water-absorbing resin, and a boiling point of 150 at normal pressure. A water-soluble compound that is 1 ° C. or more at 100 ° C. and is dissolved in 100 g of normal temperature water, and the water-soluble compound is composed of a hydroxyl group, a carboxyl group and a salt thereof, an amide group, and an amino group At least one compound selected from an organic compound having at least one functional group selected from the above, and an inorganic compound exhibiting a pH higher than the pH exhibited by the water absorbent resin, and 70% by weight of the water absorbent resin. % Or more is a water-absorbent resin composition having a particle size larger than 300 μm, and 20 g / cm 2 Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The structure which the diffusion absorption index shown by the value of 1.5 g / g * min or more may be sufficient.
[0105]
  Further, as described above, the water-absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component (polyacrylic acid ( Salt) is a powdery water-absorbing resin obtained by surface cross-linking, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And a water-soluble compound that is solid at room temperature and dissolves in an amount of 1 g or more in 100 g of water at ordinary temperature, and the water-soluble compound is a hydroxyl group, a carboxyl group and a salt thereof, an amide An organic compound having at least one functional group selected from the group consisting of a group and an amino group, and an inorganic compound exhibiting a pH higher than the pH exhibited by the water absorbent resin. At least one compound, and more than 70% by weight of the water absorbent resin, a water-absorbing resin composition having a larger particle diameter than 300 [mu] m, 20 g / cm 2 Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The structure which the diffusion absorption index shown by the value of 1.5 g / g * min or more may be sufficient.
[0106]
  Further, as described above, the water-absorbent resin composition according to the present embodiment may be configured such that the water-soluble compound is at least one alcohol selected from the group consisting of polyhydric alcohols and amino alcohols. . Further, as described above, the water absorbent resin composition according to the present embodiment may have a configuration in which the water absorption resin has a diffusion absorption ratio of 30 g / g or more.
[0107]
  Furthermore, as described above, the water-absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component (polyacrylic acid ( Salt), a polyhydric alcohol and an amino acid having a surface-crosslinked powdery water-absorbing resin, a boiling point of 150 ° C. or higher at normal pressure, and 1 g or more dissolved in 100 g of water at normal pressure. Including at least one alcohol selected from the group consisting of alcohols and a water-insoluble powder, 20 g / cm 2 Support with an inner diameter of 60 mm under a load of about 1.96 kPa 60 minutes from the start of absorption, absorbed in 1.5 g of the water-absorbent resin composition distributed inside the cylinder, passing through an opening with a diameter of 18 mm and diffusing in the resin layer direction of the water-absorbent resin composition. The diffusion capacity obtained by dividing the weight of the subsequent physiological saline (0.9 wt% sodium chloride aqueous solution) by the weight of the water absorbent resin in the water absorbent resin composition is 25 g / g or more, And the diffusion absorption index shown by the value of the maximum amount of absorption per unit time of the weight of the physiological saline absorbed by the water absorbent resin composition over 60 minutes from the start of absorption is 1.5 g / g · The structure which is more than min may be sufficient.
[0108]
  Further, as described above, the water-absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component (polyacrylic acid ( Salt), a water-absorbing resin in the form of a powder, a polyhydric alcohol that is solid at room temperature and is dissolved in 100 g of water at room temperature at 1 g or more at normal pressure, and a water-insoluble powder. Including 20g / cm 2 Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The structure which the diffusion absorption index shown by the value of 1.5 g / g * min or more may be sufficient.
[0109]
  Further, as described above, the water absorbent resin composition according to the present embodiment is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. Even if the resulting polyacrylic acid (salt) has an average particle size in the range of 200 μm to 600 μm and the proportion of particles having a particle size of less than 106 μm is 10% by weight or less, the surface is crosslinked. Good.
[0110]
  Furthermore, as described above, in the water absorbent resin composition according to the present embodiment, the water absorbent resin is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. Carboxylic polyacrylic acid (salt) having a polyacrylic acid (salt) having an average particle diameter of 200 μm to 600 μm and a ratio of particles having a particle diameter of less than 106 μm of 10% by weight or less. 12.5 solubility parameter capable of reacting with groups (cal / cm Three ) 1/2 The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cm Three ) 1/2 The structure formed by surface-crosslinking by heat-processing in presence of less than 2nd surface-crosslinking agent may be sufficient.
[0111]
  Further, as described above, the water absorbent resin composition according to the present embodiment may further include a polyamine compound having a weight average molecular weight of 5,000 or more.
[0112]
  According to the above configuration, a large amount of aqueous liquid can be quickly absorbed, and particularly excellent in urine resistance and liquid diffusibility, and the return amount of the aqueous liquid under a relatively high pressure is reduced as compared with the prior art. A water absorbent resin composition can be provided.
[0113]
  In addition, as described above, the absorbent body according to the present embodiment includes the water absorbent resin composition and the hydrophilic fiber, and the ratio of the water absorbent resin composition to the total amount of both is 40. The structure which is weight% or more may be sufficient.
[0114]
  According to said structure, the various water absorption characteristics with which a water absorbing resin composition is provided can be maintained, and the absorber excellent in the amount of water absorption per unit weight can be provided. Since the absorbent body contains the water-absorbent resin composition at a relatively high concentration, it is suitably used for sanitary materials such as paper diapers and sanitary napkins.
[0115]
【Example】
  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these. Various performances of the water-absorbent resin composition and the absorber were measured by the following methods.
[0116]
  (A) Water absorption magnification
  0.2 g of the water-absorbent resin composition was uniformly placed in a non-woven bag (60 mm × 60 mm) and immersed in physiological saline (0.9 wt% sodium chloride aqueous solution) at room temperature. After 60 minutes, the bag was pulled up, drained at 250 G for 3 minutes using a centrifuge, and then the weight W of the bag1(G) was measured. Further, the same operation was performed without using the water absorbent resin composition, and the weight W at that time was0(G) was measured. And these weights W1・ W0From the following formula,
    Water absorption ratio (g / g)
            = (Weight W1(G)-Weight W0(G)) / weight of water absorbent resin (g)
The water absorption ratio (g / g) was calculated according to The “weight of the water absorbent resin” in the formula represents the weight of the water absorbent resin in 0.2 g of the water absorbent resin composition.
[0117]
  (B) Diffusion absorption ratio
  First, a measurement apparatus used for measurement of diffusion absorption magnification will be briefly described below with reference to FIGS. 1 and 2.
[0118]
  As shown in FIG. 1, the measuring apparatus includes a balance 1, a container 2 having a predetermined capacity placed on the balance 1, an outside air intake pipe 3, a conduit 4, a glass filter 6, and the glass filter 6. It consists of the measurement part 5 mounted on the top. The container 2 has an opening 2a at the top and an opening 2b at the side, and the outside air intake pipe 3 is fitted into the opening 2a, while the conduit 4 is attached to the opening 2b. It has been. The container 2 contains a predetermined amount of physiological saline 12. The lower end of the outside air intake pipe 3 is submerged in the physiological saline 12. The glass filter 6 is formed with a diameter of 70 mm. The container 2 and the glass filter 6 are communicated with each other by a conduit 4. The glass filter 6 is fixed at a position slightly higher than the lower end of the outside air suction pipe 3.
[0119]
  As shown in FIG. 2, the measurement unit 5 includes a filter paper 7, a sheet 8, a support cylinder 9, a wire mesh 10 attached to the bottom of the support cylinder 9, and a weight 11. . The measuring unit 5 includes a filter paper 7, a sheet 8, and a support cylinder 9 (that is, a wire mesh 10) placed in this order on the glass filter 6, and a weight 11 inside the support cylinder 9, that is, on the wire mesh 10. Is placed. The sheet 8 is made of polyethylene terephthalate (PET), and is formed in a doughnut shape having a thickness of 0.1 mm having an opening with a diameter of 18 mm at the center. The support cylinder 9 has an inner diameter of 60 mm. The metal mesh 10 is made of stainless steel and is formed in JIS 400 mesh (mesh size 38 μm). A predetermined amount of the water-absorbent resin composition is uniformly distributed on the wire mesh 10. The weight 11 is 20 g / cm with respect to the wire mesh 10, that is, the water absorbent resin composition.2The weight is adjusted so that the load can be uniformly applied.
[0120]
  The diffusion absorption factor was measured using the measuring apparatus having the above configuration. The measurement method will be described below.
[0121]
  First, predetermined preparatory operations such as putting a predetermined amount of physiological saline 12 into the container 2 and fitting the outside air suction pipe 3 into the container 2 were performed. Next, the filter paper 7 was placed on the glass filter 6, and the sheet 8 was placed on the filter paper 7 so that the opening portion was positioned at the center of the glass filter 6. On the other hand, in parallel with these mounting operations, 1.5 g of the water-absorbent resin composition inside the support cylinder 9, that is, on the wire net 10 (however, the particle diameter is set to 300 μm by an operation such as weight of solid content, preferably classification). The water-absorbing resin composition 1.5 g previously adjusted to ˜500 μm was uniformly distributed, and the weight 11 was placed on the water-absorbing resin composition.
[0122]
  Next, the metal mesh 10, that is, the support cylinder 9 on which the water absorbent resin composition and the weight 11 were placed was placed on the sheet 8 so that the center portion thereof coincided with the center portion of the glass filter 6.
[0123]
  And the weight W of the physiological saline 12 which the water absorbing resin composition absorbed into water over 60 minutes from the time of mounting the support cylinder 9 on the sheet 8.2(G) was measured using the balance 1. As shown in FIG. 3, after passing through the opening of the sheet 8, the physiological saline 12 was absorbed by the water absorbent resin composition while being almost uniformly diffused in the lateral direction of the water absorbent resin composition. .
[0124]
  And the above weight W2From the following formula,
    Diffusion absorption ratio (g / g) = weight W2(G) / weight of water absorbent resin (g)
Thus, the diffusion absorption capacity (g / g) 60 minutes after the start of water absorption was calculated. The “weight of the water absorbent resin” in the formula represents the weight of the water absorbent resin in 1.5 g of the water absorbent resin composition.
[0125]
  (C) Evaluation of urine resistance and amount of water-soluble components
  First, urine was sampled evenly from 10 healthy adult boys. Next, 2 g of the water-absorbent resin composition was put in a glass bottle with a lid, and then the urine was added to swell the water-absorbent resin composition 25 times. Thereafter, the glass bottle containing the swelling gel was left for 16 hours in an atmosphere of a temperature of 37 ° C. and a relative humidity of 90%.
[0126]
  After standing, the fluidity of the swollen gel was visually observed. The fluidity was evaluated in four stages: no flow at all (● in Table 1), substantially no flow (same, ◯), some flow (same, △), and flow (same, x). .
[0127]
  Moreover, the amount of water-soluble components of the swelling gel was measured by the following method. That is, after the swollen gel was collected so that its solid content (that is, the solid content of the water-absorbent resin) was 0.5 g, the swollen gel was dispersed in 1 L of ion-exchanged water and stirred for 1 hour. Swelled. The dispersion was then filtered through filter paper, and the filtrate was titrated by a predetermined method. From the titration amount, etc., the amount of the compound dissolved in the filtrate, for example, due to deterioration of urine, specifically water-soluble polyacrylic acid (salt), etc., that is, the amount of water-soluble component (% by weight) Calculated. It can be determined that the greater the amount of water-soluble component, the higher the degree of urine degradation of the water absorbent resin composition.
[0128]
  (D) Return amount
  5 sheets of filter paper (No. 2 manufactured by Advantech Toyo Co., Ltd.) with a diameter of 90 mm are stacked, and a water-absorbent resin swollen by absorbing physiological saline from the measurement device after measuring the diffusion absorption ratio. The support cylinder 9 containing the composition was removed together with the weight 11 and placed. Next, 100 g / cm with respect to the water absorbent resin composition2The weight was further placed so that the load of 1 was uniformly applied. And 100g / cm2One minute after applying the above load, the weight of physiological saline oozed out on the filter paper was measured, and the return amount (g) was obtained.
[0129]
  (E) Diffusion absorption index
  The diffusion absorption index is measured by the measurement apparatus used for measuring the diffusion absorption magnification, and the physiological saline 12 in which the water absorbent resin composition absorbs water over 60 minutes from the time when the support cylinder 9 is placed on the sheet 8. Was measured by measuring with the balance 1 over time. That is, the weight of the physiological saline 12 is measured using the balance 1 in minutes, more preferably in seconds. From these measurement results, the maximum absorption amount per unit time is obtained, and the value is determined as the diffusion absorption index (g / g · min).
[0130]
  [Example 1]
  3.59 g of trimethylolpropane triacrylate as an internal cross-linking agent was dissolved in 5,500 g of a 39 wt% aqueous solution of sodium acrylate (hydrophilic unsaturated monomer) having a neutralization rate of 75 mol% to prepare a reaction solution. Next, this reaction solution was degassed for 30 minutes under a nitrogen gas atmosphere. Next, the above reaction solution was supplied to a predetermined reactor, and the system was replaced with nitrogen gas while keeping the reaction solution at 30 ° C. Subsequently, while stirring the reaction solution, 2.4 g of ammonium persulfate and 0.12 g of L-ascorbic acid as a polymerization initiator were added, and polymerization started about 1 minute later. And it superposed | polymerized at 30 to 80 degreeC, the reaction was complete | finished 60 minutes after starting polymerization, and the hydrogel polymer was taken out.
[0131]
  The obtained hydrogel polymer was subdivided into about 5 mm in diameter. This finely divided hydrogel polymer was spread on a 50 mesh wire net and dried with hot air at 150 ° C. for 90 minutes. Next, the dried product is pulverized using a vibration mill, and further classified with a 20 mesh wire mesh, so that the average particle size is 400 μm, and the proportion of particles having a particle size of less than 106 μm is 5% by weight. A water-absorbent resin precursor was obtained.
[0132]
  To 100 parts by weight of the obtained water-absorbing resin precursor, ethylene glycol (SP value: δ = 14.6 (cal / cmThree)1/2) 0.5 part by weight and glycerol polyglycidyl ether as a second surface cross-linking agent (SP value: δ = 10.8 (cal / cm)Three)1/2) A surface crosslinking agent solution consisting of 0.1 parts by weight, 3 parts by weight of water and 1 part by weight of ethyl alcohol was mixed. The above mixture was heat treated at 195 ° C. for 40 minutes to obtain a water absorbent resin.
[0133]
  The average particle diameter of the obtained water-absorbent resin was 400 μm, and the proportion of particles having a particle diameter of less than 106 μm was 3% by weight. Further, 70% by weight of the water-absorbent resin had a particle size larger than 300 μm. And as a result of measuring various performances of the water-absorbent resin according to the above method, the diffusion absorption capacity was 22.5 g / g after 20 minutes, 27.9 g / g after 30 minutes, and 30. It was 1 g / g. The diffusion absorption index was 1.20 g / g · min.
[0134]
  Next, by adding 69 mg of monoethanolamine (3.45% by weight with respect to the water absorbent resin) as a non-volatile water-soluble compound to 2 g of the above water absorbent resin, the water absorbent resin composition according to the present invention. I got a thing. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0135]
  [Example 2]
  Except that the amount of monoethanolamine added in Example 1 was changed from 69 mg to 168 mg (8.4% by weight with respect to the water-absorbent resin), the same reaction and operation as in Example 1 were carried out to obtain the water-absorbent resin. A composition was obtained. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0136]
  Example 3
  The same reaction as in Example 1 except that 165 mg of triethylenetetramine (8.25% by weight with respect to the water-absorbent resin) as a non-volatile water-soluble compound was used instead of 69 mg of monoethanolamine in Example 1. And operation etc. were performed and the water absorbing resin composition was obtained. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1. The amount of triethylenetetramine added is equimolar to the amount of monoethanolamine used in Example 2.
[0137]
  Example 4
  The same reaction and operation as in Example 1 except that 165 mg of glycine as a non-volatile water-soluble compound (8.25% by weight with respect to the water-absorbent resin) was used instead of 69 mg of monoethanolamine in Example 1. Etc. were performed to obtain a water absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1. In addition, the addition amount of glycine is equimolar to the addition amount of monoethanolamine used in Example 2.
[0138]
  Example 5
  2.35 g of N, N′-methylenebisacrylamide as an internal cross-linking agent was dissolved in 5,500 g of a 20 wt% acrylic acid aqueous solution to prepare a reaction solution. Next, this reaction solution was degassed for 30 minutes under a nitrogen gas atmosphere. Next, the above reaction solution was supplied to the same reactor as that in Example 1, and the system was replaced with nitrogen gas while keeping the reaction solution at 30 ° C. Subsequently, 1.5 g of ammonium persulfate and 0.07 g of L-ascorbic acid were added while stirring the reaction solution, and polymerization started about 1 minute later. And it superposed | polymerized at 30 to 80 degreeC, and 60 minutes after superposition | polymerization was started, 606.7g of sodium carbonate which is a neutralizer was added, and it stirred and neutralized. Thereafter, the reaction was terminated, and the hydrogel polymer was taken out.
[0139]
  The resulting hydrogel polymer had a neutralization rate of 75 mol% and a diameter of about 5 mm. This finely divided hydrogel polymer was spread on a 50 mesh wire net and dried with hot air at 150 ° C. for 90 minutes. Next, the dried product is pulverized using a vibration mill, and further classified with a 20-mesh wire mesh, so that the average particle size is 390 μm, and the proportion of particles having a particle size of less than 106 μm is 4% by weight. A water-absorbent resin precursor was obtained.
[0140]
  To 100 parts by weight of the obtained water-absorbing resin precursor, propylene glycol (SP value: δ = 12.6 (cal / cmThree)1/20.75 parts by weight and propylene glycol diglycidyl ether as the second surface cross-linking agent (SP value: δ = 10.1 (cal / cm)Three)1/2) A surface cross-linking agent solution consisting of 0.05 parts by weight, 3 parts by weight of water, and 0.75 parts by weight of ethyl alcohol was mixed. The above mixture was heat treated at 195 ° C. for 40 minutes to obtain a water absorbent resin.
[0141]
  The average particle size of the obtained water-absorbent resin was 390 μm, and the proportion of particles having a particle size of less than 106 μm was 3% by weight. Further, 75% by weight of the water-absorbent resin had a particle size larger than 300 μm. And as a result of measuring various performances of the water-absorbent resin according to the above methods, the diffusion absorption capacity was 16.0 g / g after 20 minutes, 24.0 g / g after 30 minutes, and 33. after 60 minutes. It was 9 g / g. The diffusion absorption index was 0.90 g / g · min.
[0142]
  Next, by adding 100 mg of glycerin as a non-volatile water-soluble compound (5.0% by weight with respect to the water-absorbing resin) to 2 g of the water-absorbing resin, the water-absorbing resin composition according to the present invention is obtained. Obtained. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1. In addition, the water absorbing resin composition had plasticity.
[0143]
  Example 6
  The same reaction and operation as in Example 5 except that 100 mg of propylene glycol (5.0% by weight with respect to the water-absorbent resin) as a non-volatile water-soluble compound was used instead of 100 mg of glycerin in Example 5. To obtain a water-absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1. In addition, the water absorbent resin composition had plasticity.
[0144]
  Example 7
  A water-absorbing resin composition was prepared by performing the same reaction and operation as in Example 5 except that 500 mg of propylene glycol (25.0% by weight with respect to the water-absorbing resin) was used instead of 100 mg of glycerin in Example 5. I got a thing. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1. In addition, the water absorbing resin composition had plasticity.
[0145]
  Example 8
  Except that 100 mg of glycerin in Example 5 was used, an aqueous solution of 100 mg of polyethylene glycol (weight average molecular weight 400,000) as a non-volatile water-soluble compound (5.0% by weight with respect to the water-absorbing resin) was used. The same reaction and operation as in Example 5 were performed to obtain a water absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method.
The results are shown in Table 1.
[0146]
  Example 9
  The same reaction and operation as in Example 5 except that 100 mg of glycolic acid as a non-volatile water-soluble compound (5.0% by weight with respect to the water-absorbing resin) was used instead of 100 mg of glycerin in Example 5. To obtain a water-absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0147]
  Example 10
  In place of 100 mg of glycerin in Example 5, a reaction similar to that in Example 5 except that an aqueous solution of malonic acid 100 mg (5.0% by weight with respect to the water-absorbent resin) as a non-volatile water-soluble compound was used. Operation etc. were performed and the water absorbing resin composition was obtained. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0148]
  Example 11
  Instead of using 100 mg of glycerin in Example 5 and neutralizing with an aqueous solution of 225 mg of sodium hydroxide (11.0% by weight with respect to the water absorbent resin), the neutralization rate of the water absorbent resin was 99 mol%. The same reaction and operation as in Example 5 were performed to obtain a water absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0149]
  Example 12
  Example 11 except that the amount of sodium hydroxide added in Example 11 was changed from 225 mg to 153 mg (7.6% by weight with respect to the water-absorbent resin), and the neutralization rate of the water-absorbent resin was changed to 92 mol%. The same reaction and operation as in were carried out to obtain a water-absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 1.
[0150]
  Example 13
  Example 11 except that the amount of sodium hydroxide added in Example 11 was changed from 225 mg to 72 mg (3.6% by weight with respect to the water absorbent resin), and the neutralization rate of the water absorbent resin was 83 mol%. The same reaction and operation as in were carried out to obtain a water-absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 2.
[0151]
  Example 14
  In place of 225 mg of sodium hydroxide in Example 11, 287 mg of sodium carbonate (14.0% by weight with respect to the water-absorbent resin) was used, and the sodium carbonate was dry-mixed to neutralize, and the neutralization rate of the water-absorbent resin The water-absorbent resin composition was obtained by carrying out the same reaction and operation as in Example 11 except that the amount was 99 mol%. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 2.
[0152]
  Example 15
  The water absorbent resin precursor obtained in Example 1 was classified, and only the water absorbent resin precursor having a particle diameter of less than 300 μm was taken out. Next, 100 parts by weight of the obtained water absorbent resin precursor is composed of 0.5 parts by weight of ethylene glycol, 0.1 parts by weight of glycerol polyglycidyl ether, 3 parts by weight of water, and 1 part by weight of ethyl alcohol. The surface crosslinker solution was mixed. The above mixture was heat treated at 195 ° C. for 40 minutes to obtain a water absorbent resin. Next, 69 mg of monoethanolamine (3.45% by weight with respect to the water absorbent resin) was added to 2 g of the water absorbent resin to obtain a water absorbent resin composition. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 2.
[0153]
  Example 16
  To 2 g of the water-absorbent resin obtained in Example 5, 100 mg of glycerin (5.0% by weight with respect to the water-absorbent resin) was added, and hydrophilic fine particulate silicon dioxide (trade name: product name: The water-absorbent resin composition according to the present invention was obtained by adding and mixing 0.5% by weight of Aerosil 200 (produced by Nippon Aerosil Co., Ltd.). And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 2. By adding silicon dioxide, urine resistance was further improved. Moreover, the diffusion absorption index of the water absorbent resin composition was 2.83 g / g · min, which was further improved.
[0154]
  Example 17
  While adding 100 mg of glycerin (5.0 wt% with respect to the water absorbent resin) to 2 g of the water absorbent resin obtained in Example 5, a 30% aqueous solution of polyethylenimine (weight average molecular weight 70,000) as a polyamine compound ( Trade name: Epomin P-1000; manufactured by Nippon Shokubai Co., Ltd.) was added and mixed so that the ratio to the water-absorbent resin was 5% by weight. After mixing, hot air drying was performed at 90 ° C. for 20 minutes. Next, the dried product was classified with a wire mesh having an opening of 840 μm.
[0155]
  Then, by adding and mixing 0.3 g of hydrophilic fine particle silicon dioxide (trade name: Carplex 22S; manufactured by Shionogi Seiyaku Co., Ltd.) as a water-insoluble powder to the wire mesh passing material, the present invention is applied. A water absorbent resin composition was obtained. And various performances of this water absorbing resin composition were measured by the above-mentioned method. The results are shown in Table 2. By adding silicon dioxide, urine resistance was further improved. Moreover, the diffusion absorption index of the water absorbent resin composition was 3.28 g / g · min, which was further improved.
[0156]
  [Comparative Example 1]
  A water-absorbent resin composition was obtained without adding a non-volatile water-soluble compound to the water-absorbent resin obtained in Example 1. That is, the water absorbent resin obtained in Example 1 was used as a comparative water absorbent resin composition as it was. Various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2.
[0157]
  [Comparative Example 2]
  A water-absorbent resin composition was prepared without adding a non-volatile water-soluble compound to the water-absorbent resin obtained in Example 5. That is, the water absorbent resin obtained in Example 5 was used as a comparative water absorbent resin composition as it was. Various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2.
[0158]
  [Comparative Example 3]
  To a reaction solution, 7.18 g of trimethylolpropane triacrylate was dissolved in 5,500 g of a 39 wt% sodium acrylate aqueous solution having a neutralization rate of 75 mol%. Next, this reaction solution was degassed for 30 minutes under a nitrogen gas atmosphere. Next, the above reaction solution was supplied to the same reactor as that in Example 1, and the system was replaced with nitrogen gas while keeping the reaction solution at 30 ° C. Subsequently, while stirring the reaction solution, 5.0 g of sodium persulfate as a polymerization initiator and 0.25 g of L-ascorbic acid were added, and polymerization started about 1 minute later. And it superposed | polymerized at 30 to 80 degreeC, the reaction was complete | finished 60 minutes after starting polymerization, and the hydrogel polymer was taken out.
[0159]
  The obtained hydrogel polymer was subdivided into about 5 mm in diameter. This finely divided hydrogel polymer was spread on a 50 mesh wire net and dried with hot air at 150 ° C. for 90 minutes. Next, the dried product is pulverized using a vibration mill, and further classified with a 20 mesh wire mesh, whereby the average particle size is 360 μm, and the proportion of particles having a particle size of less than 106 μm is 5% by weight. A water-absorbent resin precursor was obtained.
[0160]
  The water-absorbing resin precursor was used as a comparative water-absorbing resin as it was. As a result of measuring various performances of the comparative water-absorbing resin according to the above method, the diffusion absorption capacity was 3.6 g / g after 20 minutes, 5.9 g / g after 30 minutes, and after 60 minutes. It was 11.7 g / g. The diffusion absorption index was 0.20 g / g · min. Therefore, the comparative water-absorbent resin did not satisfy the desired water absorption characteristics.
[0161]
  Furthermore, it was set as the water absorbing resin composition, without adding a non-volatile water-soluble compound to the comparative water absorbing resin. That is, the above water-absorbing resin precursor was directly used as a comparative water-absorbing resin composition. Various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2. Note that the amount of return could not be measured because mamako occurred when the water-absorbent resin composition swelled during the measurement of the diffusion absorption ratio.
[0162]
  [Comparative Example 4]
  A reaction solution was prepared by dissolving 3.59 g of trimethylolpropane triacrylate in 5,500 g of a 39 wt% sodium acrylate aqueous solution having a neutralization rate of 75 mol%. Next, this reaction solution was degassed for 30 minutes under a nitrogen gas atmosphere. Next, the above reaction solution was supplied to the same reactor as that in Example 1, and the system was replaced with nitrogen gas while keeping the reaction solution at 30 ° C. Subsequently, while stirring the reaction solution, 2.4 g of ammonium persulfate and 0.12 g of L-ascorbic acid were added, and polymerization started about 1 minute later. And it superposed | polymerized at 30 to 80 degreeC, the reaction was complete | finished 60 minutes after starting polymerization, and the hydrogel polymer was taken out.
[0163]
  The obtained hydrogel polymer was subdivided into about 5 mm in diameter. This finely divided hydrogel polymer was spread on a 50 mesh wire net and dried with hot air at 150 ° C. for 90 minutes. Next, the dried product is pulverized using a vibration mill, and further classified with a 20 mesh wire mesh, so that the average particle size is 400 μm, and the proportion of particles having a particle size of less than 106 μm is 5% by weight. A water-absorbent resin precursor was obtained.
[0164]
  A surface cross-linking agent solution consisting of 0.5 parts by weight of ethylene glycol as a first surface cross-linking agent, 3 parts by weight of water, and 1 part by weight of ethyl alcohol was mixed with 100 parts by weight of the obtained water-absorbing resin precursor. . The above mixture was heat treated at 195 ° C. for 20 minutes to obtain a water absorbent resin. That is, a comparative water-absorbing resin was obtained by heat treatment without using the second surface cross-linking agent.
[0165]
  The average particle size of the comparative water absorbent resin obtained was 400 μm, and the proportion of particles having a particle size of less than 106 μm was 3% by weight. And as a result of measuring various performances of the comparative water-absorbent resin according to the above method, the diffusion absorption capacity was 5.9 g / g after 20 minutes, 7.9 g / g after 30 minutes, and after 60 minutes. It was 14.7 g / g. The diffusion absorption index was 0.87 g / g · min. Therefore, the comparative water-absorbent resin did not satisfy the desired water absorption characteristics.
[0166]
  Furthermore, it was set as the water absorbing resin composition, without adding a non-volatile water-soluble compound to the comparative water absorbing resin. That is, the comparative water absorbent resin was used as a comparative water absorbent resin composition as it was. Various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2. Note that the amount of return could not be measured because mamako occurred when the water-absorbent resin composition swelled during the measurement of the diffusion absorption ratio.
[0167]
  [Comparative Example 5]
  By adding 69 mg of monoethanolamine (3.45 wt% with respect to the comparative water absorbent resin) to 2 g of the comparative water absorbent resin obtained in Comparative Example 3, a comparative water absorbent resin composition Got. And various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2. Note that the amount of return could not be measured because mamako occurred when the water-absorbent resin composition swelled during the measurement of the diffusion absorption ratio.
[0168]
  [Comparative Example 6]
  By adding 100 mg of glycerin (5.0 wt% with respect to the comparative water absorbent resin) to 2 g of the comparative water absorbent resin obtained in Comparative Example 4, a comparative water absorbent resin composition was obtained. It was. And various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2. Note that the amount of return could not be measured because mamako occurred when the water-absorbent resin composition swelled during the measurement of the diffusion absorption ratio.
[0169]
  [Comparative Example 7]
  By adding an aqueous solution of polyethylene glycol (weight average molecular weight 400,000) 100 mg (5.0% by weight to the comparative water absorbent resin) to 2 g of the comparative water absorbent resin obtained in Comparative Example 4, A comparative water absorbent resin composition was obtained. And various performances of the comparative water-absorbent resin composition were measured by the above methods. The results are shown in Table 2. Note that the amount of return could not be measured because mamako occurred when the water-absorbent resin composition swelled during the measurement of the diffusion absorption ratio.
[0170]
[Table 1]
[0171]
[Table 2]
[0172]
  As apparent from Tables 1 and 2, the water-absorbent resin composition according to the present invention has a return amount reduced to about 2/3 to 1/2 as compared with the comparative water-absorbent resin composition. In addition, it can be seen that the urine resistance is improved about twice. In addition, when combined with a non-volatile water-soluble compound, the conventional water-absorbent resin has a diffusion absorption factor that is 20-30% lower, whereas the water-absorbent resin according to the present invention has a diffusion absorption factor of Maintained. Therefore, the water-absorbent resin according to the present invention can be suitably combined with a non-volatile water-soluble compound.
[0173]
  Example 18
  Using the water-absorbent resin composition obtained in Example 5, an absorber was prepared by the method shown below, and then a paper diaper, which was a sanitary material, was prepared.
[0174]
  That is, first, 50 parts by weight of the above water-absorbent resin composition and 50 parts by weight of pulverized wood pulp as hydrophilic fibers were dry-mixed using a mixer. Next, the resulting mixture is subjected to air papermaking on a wire screen formed in JIS 400 mesh (mesh size 38 μm) using a batch type air paper making device to form a web having a size of 120 mm × 400 mm. Molded. Further, this web is subjected to a pressure of 2 kg / cm.2The absorber was made by pressing for 5 seconds. The resin concentration of the absorber is 50% by weight. The basis weight of the absorber is about 0.047 g / cm.2Met. The water absorbent resin composition and the pulverized wood pulp could be easily and uniformly mixed.
[0175]
  Subsequently, the back sheet, the absorber, and the top sheet were attached to each other in this order using a double-sided tape. The back sheet is made of liquid-impermeable polypropylene and is cut into a predetermined shape. The top sheet is made of liquid-permeable polypropylene and is cut into substantially the same shape as the back sheet. And what was called leg gathers and what was called waist gathers were provided in the predetermined position in the said sticking thing. Furthermore, what is called a tape fastener was attached to the predetermined position in the said sticking thing. This created a paper diaper.
[0176]
  The paper diaper was very excellent in shape retention. That is, the water-absorbent resin composition was fixed by pulverized wood pulp, and no deviation or the like was observed.
[0177]
  [Comparative Example 8]
  First, it was set as the water absorbing resin composition, without adding a non-volatile water-soluble compound to the water absorbing resin obtained in Example 5. That is, similarly to Comparative Example 2, the water absorbent resin obtained in Example 5 was directly used as a comparative water absorbent resin composition. Then, using this comparative water-absorbent resin composition, the same operation as in Example 18 was performed to prepare a comparative absorbent, and then a comparative paper diaper was prepared.
[0178]
  Compared to the case of Example 18, the comparative water-absorbent resin composition and wood pulverized pulp could only be mixed non-uniformly. Further, the comparative paper diaper was inferior in shape retention as compared with the paper diaper of Example 18.
[0179]
【The invention's effect】
  As described above, the water-absorbent resin of the present invention is obtained by surface-crosslinking polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. A powdery water absorbent resin, and 20 g / cm 2 Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses in the direction of the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. And 70% by weight or more thereof has a particle diameter larger than 300 μm.
[0180]
  In addition, as described above, the water-absorbent resin of the present invention has an average particle diameter of the polyacrylic acid (salt) in the range of 200 μm to 600 μm, and particles of less than 106 μm in the polyacrylic acid (salt). The ratio of the particles having a diameter is 10% by weight or less.
[0181]
  Further, as described above, the water-absorbent resin of the present invention has a solubility parameter of 12.5 that allows the polyacrylic acid (salt) to react with the carboxyl group of the polyacrylic acid (salt). (cal / cm Three ) 1/2 The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cm Three ) 1/2 It is the structure formed by surface-crosslinking by heat-processing in presence of less than 2nd surface-crosslinking agent.
[0182]
  Furthermore, the water-absorbent resin of the present invention has a configuration in which the diffusion absorption ratio is 30 g / g or more as described above.
[0183]
  Also,The water absorbent resin composition of the present invention is as described above.The water-absorbent resin according to the present invention (that is,A powdery water-absorbing resin obtained by crosslinking the surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, And 20 g / cm2Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. InAnd 70% by weight or more of the particles have a particle size larger than 300 μm.Water absorbent resin)When,At least one selected from the group consisting of monoethanolamine, triethylenetetramine, glycine, glycerin, propylene glycol, polyethylene glycol, glycolic acid, malonic acid, sodium hydroxide, sodium carbonateContaining water-soluble compoundsI amIt is a configuration.
[0184]
  Also,As described above, the water absorbent resin composition of the present invention further includes a water-insoluble powder..
[0185]
  Further, the water absorbent resin composition of the present invention is as described above.The water-absorbent resin according to the present invention (that is,A powdery water-absorbing resin obtained by crosslinking the surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, And 20 g / cm2Under a load of about 1.96 kPa, 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm and diffuses toward the resin layer of the water-absorbing resin. The diffusion capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption by the weight of the water absorbent resin was 25 g / g or more. InAnd 70% by weight or more of the particles have a particle size larger than 300 μm.Water absorbent resin)When,At least one selected from the group consisting of monoethanolamine, triethylenetetramine, glycine, glycerin, propylene glycol, polyethylene glycol, glycolic acid, malonic acid, sodium hydroxide, sodium carbonateContaining water-soluble compoundsMuA water-absorbent resin composition, 20 g / cm2Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption absorbed while diffusing in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The diffusion absorption index indicated by the value is 1.5 g / g · min or more.
[0186]
  Also,As described above, the water-absorbent resin composition of the present invention contains the above water-soluble compound.Monoethanolamine, glycerin, propylene glycol, polyethylene glycolIt is the structure which is at least 1 type of alcohol chosen from the group which consists of. In addition, the water absorbent resin composition of the present invention has a configuration in which the diffusion coefficient of the water absorbent resin is 30 g / g or more as described above.
[0187]
  Furthermore, as described above, the water-absorbent resin composition of the present invention comprises polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. A powdery water-absorbing resin obtained by surface cross-linking,Monoethanolamine, glycerin, propylene glycol, polyethylene glycolAt least one alcohol selected from the group consisting of and a water-insoluble powder.A water absorbent resin composition comprising:20 g / cm2Under a load of (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm passes through an opening having a diameter of 18 mm, and the resin of the water absorbent resin composition The weight of physiological saline (0.9% by weight sodium chloride aqueous solution) absorbed 60 minutes after the start of absorption while being diffused in the layer direction is divided by the weight of the water absorbent resin in the water absorbent resin composition. And the maximum absorption amount per unit time of the weight of the physiological saline absorbed by the water-absorbent resin composition over 60 minutes from the start of the absorption is 25 g / g or more. The diffusion absorption index indicated by the value is 1.5 g / g · min or more.
[0188]
  Also,As described above, the water absorbent resin composition of the present invention is an average particle obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. The polyacrylic acid (salt) having a diameter of 200 μm to 600 μm and a ratio of particles having a particle diameter of less than 106 μm is 10% by weight or less is surface-crosslinked.
[0189]
  Furthermore, as described above, the water-absorbent resin composition of the present invention is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component. Reaction of a polyacrylic acid (salt) having an average particle diameter of 200 μm to 600 μm and a ratio of particles having a particle diameter of less than 106 μm of 10% by weight or less with a carboxyl group of the polyacrylic acid (salt) Possible solubility parameter is 12.5 (cal / cmThree)1/2The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cmThree)1/2It is the structure formed by surface-crosslinking by heat-processing in presence of less than 2nd surface-crosslinking agent.
[0190]
  Moreover, the water absorbing resin composition of this invention is a structure further containing the polyamine compound whose weight average molecular weight is 5,000 or more as mentioned above.
[0191]
  ThisProvided a water-absorbent resin composition that can absorb a large amount of aqueous liquid quickly, is particularly excellent in urine resistance and liquid diffusibility, and has a reduced return of aqueous liquid under relatively high pressure than before. There is an effect that can be done.
[0192]
  Further, as described above, the absorbent body of the present invention includes the water absorbent resin composition and the hydrophilic fiber, and the ratio of the water absorbent resin composition to the total amount of both is 40% by weight or more. It is the composition which is.
[0193]
  Thereby, the various water absorption characteristics with which a water absorbing resin composition is provided can be maintained, and there exists an effect that the absorber excellent in the water absorption per unit weight can be provided. Since the absorbent body contains the water-absorbent resin composition at a relatively high concentration, it is suitably used for sanitary materials such as paper diapers and sanitary napkins.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a measuring apparatus used for measuring diffusion absorption factor, which is one of the performances exhibited by a water absorbent resin composition in the present invention.
FIG. 2 is a cross-sectional view of a main part of the measuring apparatus.
FIG. 3 is an explanatory diagram for explaining the diffusion direction of physiological saline in the measurement apparatus.
[Explanation of symbols]
  1 Balance
  2 containers
  3 Outside air intake pipe
  4 conduit
  5 Measurement section
  6 Glass filter
  7 Filter paper
  8 seats
  9 Support cylinder
10 Wire mesh
11 Weight
12 Saline

Claims (14)

  1. A powdery water-absorbing resin obtained by crosslinking a surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, and,
    Under a load of 20 g / cm 2 (about 1.96 kPa), 1.5 g of the water-absorbing resin distributed inside a support cylinder having an inner diameter of 60 mm is passed through an opening having a diameter of 18 mm and the resin of the water-absorbing resin. The diffusion absorption capacity obtained by dividing the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) 60 minutes after the start of absorption absorbed while diffusing in the layer direction by the weight of the water absorbent resin is 25 g / g or more der is, and, above its 70% by weight, the water-absorbing resin characterized by having a larger particle size than 300 [mu] m.
  2. The average particle diameter of the polyacrylic acid (salt) is in the range of 200 μm to 600 μm, and the ratio of particles having a particle diameter of less than 106 μm in the polyacrylic acid (salt) is 10% by weight or less. The water-absorbent resin according to claim 1.
  3. The solubility parameter of the polyacrylic acid (salt) capable of reacting with the carboxyl group of the polyacrylic acid (salt) is 12.5. (cal / cm Three ) 1/2 The above first surface cross-linking agent and the solubility parameter is 12.5 (cal / cm Three ) 1/2 The water-absorbent resin according to claim 2, wherein the water-absorbent resin is surface-crosslinked by heat treatment in the presence of less than the second surface-crosslinking agent.
  4. The water-absorbent resin according to any one of claims 1 to 3, wherein the diffusion absorption factor is 30 g / g or more.
  5. A water-absorbent resin according to claim 1 ;
    Monoethanolamine, triethylenetetramine, glycine, glycerol, propylene glycol, polyethylene glycol, glycolic acid, malonic acid, sodium hydroxide, characterized in that at least one water-soluble compound selected from the group consisting of sodium carbonate and Nde contains A water-absorbent resin composition.
  6. The water- absorbent resin composition according to claim 5, further comprising a water-insoluble powder .
  7. A water-absorbent resin according to claim 1;
    Water-absorbent resin composition comprising at least one water-soluble compound selected from the group consisting of monoethanolamine, triethylenetetramine, glycine, glycerin, propylene glycol, polyethylene glycol, glycolic acid, malonic acid, sodium hydroxide, sodium carbonate Because
    Under a load of 20 g / cm 2 (about 1.96 kPa), 1.5 g of the water-absorbent resin composition distributed in a support cylinder having an inner diameter of 60 mm is passed through an opening having a diameter of 18 mm and the water-absorbent resin. Absorbed while diffusing in the resin layer direction of the composition, the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) 60 minutes after the start of absorption is used as the water absorbent resin in the water absorbent resin composition. Per unit time of the weight of the physiological saline, which is obtained by dividing by the weight of, and is 25 g / g or more, and the water-absorbent resin composition absorbs over 60 minutes from the start of the absorption. A water-absorbent resin composition having a diffusion absorption index represented by a maximum absorption value of 1.5 g / g · min or more .
  8. The water-soluble compound is at least one alcohol selected from the group consisting of monoethanolamine, glycerin, propylene glycol, and polyethylene glycol. The water-absorbent resin composition according to any one of claims 5 to 7, characterized in that
  9. The water-absorbent resin composition according to any one of claims 5 to 8, wherein the diffusion coefficient of the water-absorbent resin is 30 g / g or more.
  10. A powdery water-absorbing resin obtained by crosslinking the surface of polyacrylic acid (salt) obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component;
    At least one alcohol selected from the group consisting of monoethanolamine, glycerin, propylene glycol, and polyethylene glycol;
    A water-absorbent resin composition comprising a water-insoluble powder,
    Under a load of 20 g / cm 2 (about 1.96 kPa), 1.5 g of the water absorbent resin composition distributed inside a support cylinder having an inner diameter of 60 mm is passed through an opening having a diameter of 18 mm and the water absorbent resin. Absorbed while diffusing in the resin layer direction of the composition, the weight of the physiological saline (0.9 wt% sodium chloride aqueous solution) 60 minutes after the start of absorption is used as the water absorbent resin in the water absorbent resin composition. Per unit time of the weight of the physiological saline, which is obtained by dividing by the weight of, and is 25 g / g or more, and the water-absorbent resin composition absorbs over 60 minutes from the start of the absorption. A water-absorbent resin composition having a diffusion absorption index represented by a maximum absorption value of 1.5 g / g · min or more .
  11. The water-absorbent resin is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, and has an average particle diameter of 200 μm to 600 μm and a particle diameter of the proportion of particles less than 106μm is 10 wt% or less of the polyacrylic acid (salt), 5 claims, characterized by comprising surface cross-linked to the water-absorbent resin composition according to any one of 10.
  12. The water-absorbent resin is obtained by polymerizing a hydrophilic unsaturated monomer containing acrylic acid and / or acrylate as a main component, and has an average particle diameter of 200 μm to 600 μm and a particle diameter of A solubility parameter of 12.5 (cal / cm 3 ) 1 / which can react polyacrylic acid (salt) with a proportion of particles of less than 106 μm of 10% by weight or less with a carboxyl group of the polyacrylic acid (salt). It is characterized by surface crosslinking by heat treatment in the presence of two or more first surface crosslinking agents and a second surface crosslinking agent having a solubility parameter of less than 12.5 (cal / cm 3 ) 1/2. The water absorbent resin composition according to any one of claims 5 to 10 .
  13. The water absorbent resin composition according to any one of claims 5 to 12 , further comprising a polyamine compound having a weight average molecular weight of 5,000 or more .
  14. The water-absorbent resin composition according to any one of claims 5 to 13 and a hydrophilic fiber, and the ratio of the water-absorbent resin composition to the total amount of both is 40% by weight or more. Absorber characterized by.
JP32330595A 1995-12-12 1995-12-12 Water-absorbing resin, water-absorbing resin composition and absorber Expired - Fee Related JP3712453B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP32330595A JP3712453B2 (en) 1995-12-12 1995-12-12 Water-absorbing resin, water-absorbing resin composition and absorber

Applications Claiming Priority (11)

Application Number Priority Date Filing Date Title
JP32330595A JP3712453B2 (en) 1995-12-12 1995-12-12 Water-absorbing resin, water-absorbing resin composition and absorber
TW085109593A TW522024B (en) 1995-09-01 1996-08-07 Absorbing agent composite, absorbent material, and absorbent product containing absorbent material
US08/703,882 US5797893A (en) 1995-09-01 1996-08-27 Absorbing agent composition, absorbent material, and absorbent product containing absorbent material
EP96306263A EP0761241B1 (en) 1995-09-01 1996-08-29 An absorbent composition, absorbent material, and absorbent product containing absorbent material
DE69628791A DE69628791D1 (en) 1995-09-01 1996-08-29 Absorbent composition, absorbent material, and an absorbent product containing the absorbent material.
EP07005677A EP1806153A1 (en) 1995-09-01 1996-08-29 Absorbing agent composition, absorbent material, and absorbent product containing absorbent material
DE69628791T DE69628791T2 (en) 1995-09-01 1996-08-29 Absorbent composition, absorbent material, and an absorbent product containing the absorbent material.
EP03076151A EP1358892A1 (en) 1995-09-01 1996-08-29 Absorbing agent composition, absorbent material, and absorbent product containing absorbent material
KR1019960037234A KR100197888B1 (en) 1995-09-01 1996-08-30 Absorbing agent composition, absorbent material, and absorbent product containing absorbent material
SG9610562A SG84496A1 (en) 1995-09-01 1996-08-31 Absorbing agent composition, absorbent material, and absorbent product containing absorbent material
KR1019960072413A KR970032914A (en) 1995-09-01 1996-12-26 Method and apparatus for controlling the thermal profile of the skin

Publications (2)

Publication Number Publication Date
JPH09157534A JPH09157534A (en) 1997-06-17
JP3712453B2 true JP3712453B2 (en) 2005-11-02

Family

ID=18153305

Family Applications (1)

Application Number Title Priority Date Filing Date
JP32330595A Expired - Fee Related JP3712453B2 (en) 1995-12-12 1995-12-12 Water-absorbing resin, water-absorbing resin composition and absorber

Country Status (1)

Country Link
JP (1) JP3712453B2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2216822T3 (en) * 2000-04-13 2004-11-01 Bristol-Myers Squibb Company absorbent material and production method.
US7169843B2 (en) * 2003-04-25 2007-01-30 Stockhausen, Inc. Superabsorbent polymer with high permeability
DE10334286B4 (en) * 2003-07-25 2006-01-05 Stockhausen Gmbh Powdered, water-absorbing polymers with fine particles bound by means of thermoplastic adhesives, process for their preparation and chemical products and compounds containing them
JP5014607B2 (en) * 2004-09-24 2012-08-29 株式会社日本触媒 Particulate water-absorbing agent mainly composed of water-absorbing resin
US8729190B2 (en) 2007-03-01 2014-05-20 Nippon Shokubai Co., Ltd. Particular water-absorbent agent having water-absorbent resin as main component
CN104175357B (en) * 2014-09-02 2016-08-24 安庆市恒昌机械制造有限责任公司 A kind of waste material siphon mechanism on disposable sanitary articles production line

Also Published As

Publication number Publication date
JPH09157534A (en) 1997-06-17

Similar Documents

Publication Publication Date Title
US6620889B1 (en) Powdery, crosslinked absorbent polymers, method for the production thereof, and their use
US7960469B2 (en) Water absorbent resin composition and production method thereof
EP0999238B1 (en) Water-absorbing agent and production process therefor
EP1874364B1 (en) Surface cross-linked superabsorber treated with a silica compound and a al3+ salt
DE60216911T2 (en) Water absorption, production and sanitary articles
DE60038504T2 (en) Super absorbing polymers with a slow absorption rate
EP0668080B1 (en) Water-absorbent agent, method for production thereof, and water-absorbent composition
EP0509708B2 (en) Method of preparation of surface crosslinked resin particles
CN1171933C (en) Absorbent compsn.
EP1029886B2 (en) Water-absorbent resin powder and its production process and use
JP5222721B2 (en) Water-absorbing polymer structure having high absorbency
CA2171085C (en) Powder-form polymers capable of absorbing aqueous liquids, method of preparing them and their use as absorbents
KR100849526B1 (en) Particulate water absorbing agent with water-absorbing resin as main component
US5447727A (en) Water-absorbent polymer having improved properties
EP2272898B1 (en) Water-absorbent polymer particles and production process therefor
EP1969053B1 (en) Thermoplastic coated superabsorbent polymer compositions
AU784834B2 (en) Pulverulent, cross-linked polymers, capable of absorbing aqueous liquids
CN1246046C (en) Water absorbent and preparation method
KR100819613B1 (en) Water absorbent and producing method of same
EP1315528B1 (en) Pulverulent, cross-linked polymers, capable of absorbing aqueous liquids and blood
CN100349964C (en) Water-absorbing agent and its production process and use
US7402643B2 (en) Water-absorbent resin having treated surface and process for producing the same
EP0629411B1 (en) Absorbent composition and disposable diaper containing the same
ES2266783T3 (en) Mixtures of polymers with a better odor control.
US7396584B2 (en) Crosslinked polyamine coating on superabsorbent hydrogels

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20040607

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20040615

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20040813

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20050104

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20050203

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050307

A911 Transfer of reconsideration by examiner before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20050310

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050517

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050719

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20050816

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20050817

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090826

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100826

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100826

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110826

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120826

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120826

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130826

Year of fee payment: 8

LAPS Cancellation because of no payment of annual fees