Method of manufacturing water-absorbent resin, water-absorbent resin, water-absorbing agent and absorbent article

With respect to water-absorbent resins, there are provided a method of manufacturing a water-absorbent resin having an appropriate BET specific surface and a water-absorption rate and a water-absorbing agent and an absorbent article that are formed by using the water-absorbent resin. In a first aspect of the present invention, when reverse phase suspension polymerization of two steps or more is performed on a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium in the presence of at least an azo compound, a peroxide and an internal-crosslinking agent, the used amount of the internal-crosslinking agent at the time of the polymerization of a first step is adjusted to fall within a range of 0.015 to 0.150 mmol per mole of the water-soluble ethylenically unsaturated monomer used at the time of the polymerization of the first step and he polymerization is performed such that, the BET specific surface area of secondary particles formed by agglomeration of primary particles obtained is controlled.

WATER-ABSORBENT RESIN AND ABSORBENT ARTICLE

Provided is: a water-absorbent resin which has a better water absorption performance and with which it is possible to improve absorption performance under a load when used in an absorbent material. This water-absorbent resin, obtained by polymerizing a water soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent and by post-crosslinking using a post-crosslinking agent, has a water-absorption capacity of physiological saline under a load of 4.14 kPa of 16 mL/g or more, has a mass proportion of particles from 150 to 850 μm relative to the whole proportion of 85 mass % or more, moreover has a mass proportion of particles from 300 to 400 μm relative to the whole proportion of 20 mass % or more, and has an absorption capacity elasticity index represented by formula (I) of 68,000 or more. Absorption capacity elasticity index=storage elastic modulus [Pa]×centrifugal retention rate [g/g] . . . (I) 1. A water-absorbent resin which is obtained by polymerizing a water-soluble ethylenically unsaturated monomer in presence of an internal-crosslinking agent and performing post-crosslinking with a post-crosslinking agent ,wherein a water-absorption capacity of physiological saline under a load of 4.14 kPa is 16 mL/g or more,a mass proportion of particles from 150 to 850 μm relative to the whole proportion is 85 mass % or more, moreover a mass proportion of particles from 300 to 400 μm relative to the whole proportion is 20 mass % or more, and {'br': None, 'absorption capacity elasticity index=storage elastic modulus [Pa]×centrifugal retention rate [g/g]\u2003\u2003(I)'}, 'an absorption capacity elasticity index represented by formula (I) is 68000 or more.'}2. The water-absorbent resin according to claim 1 , wherein tan δ measured by sizing the 300 to 400 μm particles of the water-absorbent resin is 2.00×10or less.3. An absorbent article which is formed with an absorbent material containing the water-absorbent resin according to .4. An absorbent ...

METHOD OF MANUFACTURING WATER-ABSORBENT RESIN, WATER-ABSORBENT RESIN, WATER-ABSORBING AGENT AND ABSORBENT ARTICLE

With respect to water-absorbent resins, there are provided a method of manufacturing a water-absorbent resin having an appropriate BET specific surface and a water-absorption rate and a water-absorbing agent and an absorbent article that are formed by using the water-absorbent resin. In a first aspect of the present invention, when reverse phase suspension polymerization of two steps or more is performed on a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium in the presence of at least an azo compound, a peroxide and an internal-crosslinking agent, the used amount of the internal-crosslinking agent at the time of the polymerization of a first step is adjusted to fall within a range of 0.015 to 0.150 mmol per mole of the water-soluble ethylenically unsaturated monomer used at the time of the polymerization of the first step and he polymerization is performed such that, the BET specific surface area of secondary particles formed by agglomeration of primary particles obtained is controlled. 1. A method of manufacturing a water-absorbent resin , wherein when reverse phase suspension polymerization of two steps or more is performed on a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium in presence of at least an azo compound , a peroxide and an internal-crosslinking agent ,the polymerization at each step being performed in the presence of an azo compound and a peroxide,a used amount of the internal-crosslinking agent at the time of the polymerization of a first step for 1 mole of the water-soluble ethylenically unsaturated monomer used at the time of the polymerization of the first step is adjusted to fall within a range of 0.015 to 0.150 mmol and the polymerization is performed such that a BET specific surface area of secondary particles formed by agglomeration of primary particles obtained is controlled.2. The method of manufacturing a water-absorbent resin according to claim 1 , wherein a used amount ( ...

WATER-ABSORBENT RESIN AND ABSORBENT ARTICLE

Provided are: a water-absorbent resin which, when used as an absorbent material, retains a high water-absorption performance, increases the diffusivity of a to-be-absorbed liquid and makes it possible to effectively decrease the amount of re-wet; and an absorbent article formed using an absorbent material including the water-absorbent resin. The water-absorbent resin according to the present invention is a water-absorbent resin obtained by polymerizing a water-soluble ethylenically monomer in the presence of an internal-crosslinking agent and thereafter post-crosslinking the polymer with a post-crosslinking agent, characterized in that when subjected to a liquid flow test, the water-absorbent resin has an effective absorbent material index (K) indicated by equation (I) of 250 or greater. 2. The water-absorbent resin according to claim 1 , wherein the artificial-urine absorption ratio is 30.0 g/g or more.3. The water-absorbent resin according to claim 1 , wherein the amount of liquid flow is 5.0 g or more.4. An absorbent article using an absorbent material comprising the water-absorbent resin according to .5. The water-absorbent resin according to claim 2 , wherein the amount of liquid flow is 5.0 g or more.6. An absorbent article using an absorbent material comprising the water-absorbent resin according to .7. An absorbent article using an absorbent material comprising the water-absorbent resin according to .8. An absorbent article using an absorbent material comprising the water-absorbent resin according to . The present invention relates to a water-absorbent resin and an absorbent article, and more specifically relates to a water-absorbent resin forming an absorbent material suitably used for hygienic materials such as disposable diapers, sanitary napkins and incontinence pads as well as an absorbent article comprising the water-absorbent resin.In recent years, water-absorbent resins have been widely used in the field of hygienic materials such as disposable ...

WATER-ABSORBENT RESIN AND ABSORBENT ARTICLE

The following are provided: a water-absorbent resin in which, in the formation of an absorbent material forming an absorbent article, dispersion is satisfactory even in a moisture absorption state, which prevents the occurrence of troubles at the time of manufacturing of the absorbent article and which allows efficient manufacturing; and an absorbent article using an absorbent material containing the water-absorbent resin. The water-absorbent resin according to the present invention is obtained by polymerizing a water-soluble ethylenically unsaturated monomer and performing post-crosslinking thereon with a post-crosslinking agent, and the water-absorbent resin satisfies the requirements below: 2. (canceled)3. An absorbent article that uses an absorbent material comprising the water-absorbent resin according to . The present invention relates to a water-absorbent resin and an absorbent article, and more particularly relates to a water-absorbent resin forming an absorbent material suitably used for hygienic materials such as sanitary articles and disposable diapers and to an absorbent article using its resin.In recent years, water-absorbent resins have been widely used in the fields of hygienic materials such as sanitary articles and disposable diapers.For water-absorbent resins as described above, crosslinked products of partially neutralized polymers of acrylic acid are preferred because they have many advantages, including the followings: they have excellent water-absorption performance; their raw materials such as acrylic acid has easy industrial availability, and therefore they can be produced with stable quality and low cost; and they show no shortcomings such as in which decomposition is likely to occur.In the fields of hygienic materials such as sanitary articles and disposable diapers, such a water-absorbent resin is used to form an absorbent material, and by the means that the absorbent material is held between a liquid permeable sheet (top sheet) through ...

Water-absorbent resin and absorbent article

Provided are a water-absorbent resin having better water-absorption performance and being prevented from discoloring before and after storage for a long time under high temperature and high humidity, and an absorbent article including the absorbent resin. The water-absorbent resin according to the present invention is prepared by polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent and performing post-crosslinking with a post-crosslinking agent, wherein the water-absorbent resin satisfies the following properties: (A) a water-absorption capacity of physiological saline of 55 g/g or more, a water-absorption capacity of physiological saline under a load of 4.14 kPa of 15 mL/g or more, and a residual monomer content of 300 ppm or less; and (B) a yellow index of 5.0 or less and a yellow index change ratio (ΔYI) after leaving for 10 days under 70° C. and 90% RH of 10 or less.

WATER-ABSORBENT RESIN AND METHOD OF PRODUCING WATER-ABSORBENT RESIN

Provided is a water-absorbent resin that increases the diffusivity of a to-be-absorbed liquid and that makes it possible to effectively decrease the amount of re-wet. The water-absorbent resin is obtained by polymerizing a water-soluble ethylenicallyally unsaturated monomer under the presence of an internal-crosslinking agent, has the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption of 20 ml/g or more, and exhibits the degree of swelling under a load at 30 minutes of 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes from the start of water absorption is designated as the degree of swelling under a load of 100%. 1. A method of producing a water-absorbent resin by performing reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent in a hydrocarbon dispersion medium , the method comprising the steps of:performing polymerization step in the presence of an azo based compound and a peroxide, and performing post-crosslinking step of a hydrous gel-like material obtained from the polymerization using a post-crosslinking agent.2). The method of producing a water-absorbent resin according to claim 1 , wherein the azo based compound is at least one selected from the group consisting of 2 claim 1 ,2′-azobis(2-amidinopropane)dihydrochloride claim 1 , 2 claim 1 ,2′-azobis{2-[1-(2-hydroxyethyl)-2-imidazoline-2-yl]propane}dihydrochloride and 2 claim 1 ,2′-azobis[N-(2-carboxyethyl)-2-methylpropione amidine]tetrahydrate.3. The method of producing a water-absorbent resin according to claim 1 , wherein the peroxide is at least one selected from the group consisting of potassium persulfate claim 1 , ammonium persulfate claim 1 , sodium persulfate and hydrogen peroxide.4. The method of producing a water-absorbent resin according to claim 1 , wherein the internal ...

Water-absorbent resin particles

Disclosed are water-absorbent resin particles comprising a crosslinked polymer comprising a monomer unit derived from a water-soluble ethylenically unsaturated monomer, wherein an initial swelling force as measured according to a swelling force test conducted by a predetermined method is 8 N or more, and further, a ratio of the particles having a particle diameter of more than 250 μm and 850 μm or less is 70% by mass or more and a ratio of the particles having a particle diameter of 250 μm or less is 20% by mass or less, with respect to the total amount of the water-absorbent resin particles.

WATER-ABSORBENT RESIN PARTICLE

Disclosed are water-absorbent resin particles comprising a crosslinked polymer comprising a monomer unit derived from a water-soluble ethylenically unsaturated monomer, wherein an artificial menstrual blood volume increase rate as measured in an artificial menstrual blood swelling test conducted in the order of i), ii), and iii) is 70% or more. i) putting 1.0 g of water-absorbent resin particles into a measuring cylinder with an inner diameter of 27 mm. ii) injecting 10 ml of artificial menstrual blood into the cylinder at once to swell the water-absorbent resin particles. iii) measuring a volume (A) of the swollen water-absorbent resin particles after 60 seconds from the injection and calculating an artificial menstrual blood volume increase rate according to Equation (I) below. Artificial menstrual blood volume increase rate (%)=(A−B)/B×100 . . . (I), A . . . Volume (ml) of swollen water-absorbent resin particles, B . . . Volume (ml) of injected artificial menstrual blood. 1. Water-absorbent resin particles comprising a crosslinked polymer comprising a monomer unit derived from a water-soluble ethylenically unsaturated monomer ,wherein an artificial menstrual blood volume increase rate as measured in an artificial menstrual blood swelling test conducted in the following order of i), ii), and iii) is 70% or more:i) putting 1.0 g of water-absorbent resin particles into a measuring cylinder with an inner diameter of 27 mm,ii) injecting 10 ml of artificial menstrual blood into the cylinder at once to swell the water-absorbent resin particles, and {'br': None, 'i': A−B', 'B×, 'Artificial menstrual blood volume increase rate (%)=()/100\u2003\u2003(I)'}, 'iii) measuring, a volume (A) of the swollen water-absorbent resin particles after an elapse of 60 seconds from the injection and calculating an artificial menstrual blood volume increase rate according to Equation (I) belowA . . . Volume (ml) of swollen water-absorbent resin particlesB . . . Volume (ml) of injected ...

METHOD FOR PRODUCING WATER-ABSORBENT RESIN PARTICLES

There is disclosed a method for producing water-absorbent resin particles comprising a step that includes reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a suspension containing a surfactant that comprises a surfactant that comprises a fatty acid ester of sorbitan or sorbitol, or derivative thereof, and a hydrocarbon dispersion medium. The fatty acid ester includes a lauric acid ester and at least one kind of other ester selected from the group consisting of palmitic acid esters, stearic acid esters and behenic acid esters. The proportion of the peak area for lauric acid ester is 30-60%, based on the total peak area for fatty acid esters in the GPC chromatogram obtained from the fatty acid esters, and the proportion of the total peak area for other ester is 10-50%. 1. A method for producing water-absorbent resin particles , comprising a step that includes carrying out reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a suspension containing a surfactant that comprises a fatty acid ester of sorbitan , sorbitol or a derivative thereof , and a hydrocarbon dispersion medium ,wherein the fatty acid ester includes a lauric acid ester and at least one kind of other ester selected from the group consisting of palmitic acid esters, stearic acid esters and behenic acid esters, andin a GPC chromatogram obtained from the fatty acid ester, the proportion of the peak area due to the lauric acid ester is 30-60% and the proportion of the total peak area due to the other ester is 10-50%, based on the total peak area due to the fatty acid esters.2. The method for producing water-absorbent resin particles according to claim 1 , wherein the fatty acid ester is at least one selected from the group consisting of sorbitan fatty acid esters claim 1 , polyoxyethylene sorbitan fatty acid esters claim 1 , sorbitol fatty acid esters and polyoxyethylene sorbitol fatty acid esters. The present ...

Water-absorbent resin and method of producing water-absorbent resin

Provided is a water-absorbent resin that increases the diffusivity of a to-be-absorbed liquid and that makes it possible to effectively decrease the amount of re-wet. The water-absorbent resin is obtained by polymerizing a water-soluble ethylenicallyally unsaturated monomer under the presence of an internal-crosslinking agent, has the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption of 20 ml/g or more, and exhibits the degree of swelling under a load at 30 minutes of 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes from the start of water absorption is designated as the degree of swelling under a load of 100%. The water-absorbent resin can be produced by performing the following steps in a method in which a water-absorbent resin is produced by performing reverse phase suspension polymerization of a water-soluble ethylenicallyally unsaturated monomer in a hydrocarbon dispersion medium under the presence of an internal-crosslinking agent: a step in which polymerization is performed under the presence of an azo compound and a peroxide; and a step in which a water-containing gel obtained by said polymerization is post-crosslinked using a post-crosslinking agent.

Water-absorbent resin and absorbent article

Provided are a water-absorbent resin having better water-absorption performance and being prevented from discoloring before and after storage for a long time under high temperature and high humidity, and an absorbent article including the absorbent resin. The water-absorbent resin according to the present invention is prepared by polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent and performing post-crosslinking with a post-crosslinking agent, wherein the water-absorbent resin satisfies the following properties: (A) a water-absorption capacity of physiological saline of 55 g/g or more, a water-absorption capacity of physiological saline under a load of 4.14 kPa of 15 mL/g or more, and a residual monomer content of 300 ppm or less; and (B) a yellow index of 5.0 or less and a yellow index change ratio (ΔYI) after leaving for 10 days under 70° C. and 90% RH of 10 or less.

MANUFACTURING METHOD FOR ABSORBING BODY

A method for manufacturing an absorbent body according to the present invention includes a first step of successively introducing an aggregate of absorbent fibers and a water-absorbent resin into a gap that is formed between a first surface and a second surface and is smaller than a thickness of the aggregate of the absorbent fibers, recesses and protrusions being formed on at least one of the first surface and the second surface, a second step of applying a shearing force to the aggregate of the absorbent fibers by moving the first surface relative to and parallel to the second surface in order to mix the absorbent fibers and the water-absorbent resin, and a third step of causing the absorbent fibers and the water-absorbent resin that were mixed to fall, and stacking the absorbent fibers and the water-absorbent resin by suctioning the absorbent fibers and the water-absorbent resin into a recessed portion having a predetermined shape. 1. A method for manufacturing an absorbent body , comprising:a first step of successively introducing an aggregate of absorbent fibers and a water-absorbent resin into a gap that is formed between a first surface and a second surface and is smaller than a thickness of the aggregate of the absorbent fibers, recesses and protrusions being formed on at least one of the first surface and the second surface;a second step of applying a shearing force to the aggregate of the absorbent fibers by moving the first surface relative to and parallel to the second surface in order to mix the absorbent fibers and the water-absorbent resin; anda third step of causing the absorbent fibers and the water-absorbent resin that were mixed to fall, and stacking the absorbent fibers and the water-absorbent resin by suctioning the absorbent fibers and the water-absorbent resin into a recessed portion having a predetermined shape.2. The method for manufacturing an absorbent body according to claim 1 , wherein in the first step claim 1 , the water-absorbent ...

WATER ABSORBING RESIN PARTICLES

São divulgadas partículas de resina absorventes de água compreendendo um polímero reticulado compreendendo uma unidade de monômero derivada a partir de um monômero insaturado por etileno solúvel em água, em que uma força de intumescimento inicial como medida de acordo com um teste de força de intumescimento conduzido por um método predeterminado é de 8 N ou mais, e adicionalmente, uma razão das partículas tendo um diâmetro de partícula de mais do que 250 μm e 850 μm ou menos é de 70% em massa ou mais e uma razão das partículas tendo um diâmetro de partícula de 250 μm ou menos é de 20% em massa ou menos, com relação à quantidade total das partículas de resina absorventes de água. Water-absorbing resin particles comprising a cross-linked polymer comprising a monomer unit derived from a water-soluble ethylene-unsaturated monomer are disclosed, wherein an initial swelling force as measured in accordance with a swelling force test conducted by a predetermined method is 8 N or more, and in addition, a ratio of particles having a particle diameter of more than 250 μm and 850 μm or less is 70% by mass or more and a ratio of particles having a diameter of particle size of 250 μm or less is 20% by mass or less with respect to the total amount of water-absorbing resin particles.

Method for producing water absorbent resin particles

There is disclosed a method for producing water-absorbent resin particles comprising a step that includes reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a suspension containing a surfactant that comprises a surfactant that comprises a fatty acid ester of sorbitan or sorbitol, or derivative thereof, and a hydrocarbon dispersion medium. The fatty acid ester includes a lauric acid ester and at least one kind of other ester selected from the group consisting of palmitic acid esters, stearic acid esters and behenic acid esters. The proportion of the peak area for lauric acid ester is 30-60%, based on the total peak area for fatty acid esters in the GPC chromatogram obtained from the fatty acid esters, and the proportion of the total peak area for other ester is 10-50%.

WATER-ABSORBING RESIN PARTICLE

São divulgadas partículas de resina absorventes de água compreendendo um polímero reticulado compreendendo uma unidade de monômero derivada a partir de um monômero insaturado por etileno solúvel em água, em que uma taxa de aumento de volume de sangue menstrual artificial como medida em um teste de intumescimento de sangue menstrual artificial conduzido na ordem de i), ii), e iii) é de 70% ou mais. i) colocar 1,0 g de partículas de resina absorventes de água em um cilindro de medição com um diâmetro interno de 27 mm. ii) injetar 10 ml de sangue menstrual artificial no cilindro de uma vez para intumescer as partículas de resina absorventes de água. iii) medir um volume (A) das partículas intumescidas de resina absorventes de água após 60 segundos a partir da injeção e calcular uma taxa de aumento de volume de sangue menstrual artificial de acordo com a Equação (I) abaixo. Taxa de aumento de volume de sangue menstrual artificial (%) = (A-B)/Bx100 ... (I), A ... Volume (ml) de partículas de resina absorventes de água intumescidas, B ... Volume (ml) de sangue menstrual artificial injetado. Water-absorbing resin particles comprising a cross-linked polymer comprising a monomer unit derived from a water-soluble ethylene unsaturated monomer are disclosed, at which an artificial menstrual blood swelling rate as measured in a swelling test of artificial menstrual blood conducted in the order of i), ii), and iii) is 70% or more. i) place 1.0 g of water-absorbing resin particles in a measuring cylinder with an internal diameter of 27 mm. ii) inject 10 ml of artificial menstrual blood into the cylinder at once to swell the water-absorbing resin particles. iii) measure a volume (A) of the swollen particles of water-absorbing resin after 60 seconds from the injection and calculate a rate of increase in volume of artificial menstrual blood according to Equation (I) below. Increase rate of artificial menstrual blood volume (%) = (AB) / Bx100 ... (I), A ... Volume (ml) of swollen ...

Water-absorbent resin and absorbent article

Provided are: a water-absorbing resin which has an excellent water absorption performance and with which it is possible to improve absorption performance under a load when used in an absorbent body; and an absorbent article using an absorbent body that includes the water-absorbing resin. This water-absorbing resin, obtained by polymerising a water soluble ethylenically unsaturated monomer in the presence of an internal crosslinking agent and by post-crosslinking using a post-crosslinking agent, has a physiological saline absorption capacity of 16 mL/g or more under a load of 4.14 kPa, has a mass ratio of 85 mass% or more of 150-850 µm particles that account for a proportion of the entire water-absorbing resin, moreover has a mass ratio of 20 mass% or more of 300-400 µm particles, and has an absorption capacity elasticity index represented by formula (I) of 68,000 or more. Absorption capacity elasticity index = storage elastic modulus [Pa] × centrifugal retention rate [g/g] ...(I)

Water-absorbent resin and absorbent article

本發明提供一種吸水性樹脂及使用吸收體而成的吸收性物品，該吸收體包含該吸水性樹脂；其中，該吸水性樹脂，當形成用以構成吸收性物品的吸收體時，即便在吸溼狀態，分散性亦良好，並且可防止在製造吸收性物品時發生問題，而能夠有效率地製造。 關於本發明中的吸水性樹脂，其是藉由使水溶性乙烯性不飽和單體進行聚合，並且利用後交聯劑進行後交聯來獲得，其中，該吸水性樹脂的特徵在於滿足以下的要件：(A)黃色度是5.0以下、(B)膠體強度是1800Pa以下。

Water-absorbent resin and absorbent article

Provided are: a water-absorbing resin which, when used as an absorbent, retains a high water-absorbing ability and has such a property that the liquid to be absorbed is highly diffusible therethrough and can be inhibited from oozing out backward; and an absorbent article formed using an absorbent including the water-absorbing resin. The water-absorbing resin according to the present invention is a water-absorbing resin obtained by polymerizing a water-soluble ethylenic monomer in the presence of an internal crosslinking agent and thereafter crosslinking the polymer with a post-crosslinking agent, characterized in that when subjected to a liquid flow test, the water-absorbing resin has an effective absorbent index (K) indicated by equation (I) of 250 or greater. Effective absorbent index (K) = [(liquid flow amount) (g)]×[(artificial-urine absorption ratio) (g/g)] (I)

Water-absorbent resin and method of producing water-absorbent resin

Provided is a water-absorbent resin that increases the diffusivity of a to-be-absorbed liquid and that makes it possible to effectively decrease the amount of re-wet. The water-absorbent resin is obtained by polymerizing a water-soluble ethylenicallyally unsaturated monomer under the presence of an internal-crosslinking agent. The water-absorbent resin further exhibits a degree of swelling under a load. The water-absorbent resin can be produced by performing the following steps in a method in which a water-absorbent resin is produced by performing reverse phase suspension polymerization of a water-soluble ethylenicallyally unsaturated monomer in a hydrocarbon dispersion medium under the presence of an internal-crosslinking agent: a step in which polymerization is performed under the presence of an azo compound and a peroxide; and a step in which a water-containing gel obtained by said polymerization is post-crosslinked using a post-crosslinking agent.

METHOD OF MANUFACTURING ABSORBENT WATER RESIN, WATER ABSORBING RESIN, WATER ABSORBING AGENT AND ABSORBING ARTICLE

No que diz respeito a resinas absorventes de água, são proporcionados um método de fabricação de uma resina absorvente de água que possui uma superfície específica BET apropriada e uma taxa de absorção de água e um agente absorvente de água e um artigo absorvente que são formados usando a resina absorvente de água. Em um primeiro aspecto da presente invenção, quando a polimerização em suspensão de fase reversa de duas ou mais etapas é realizada em um monômero etilenicamente insaturado solúvel em água em um meio de dispersão de hidrocarboneto na presença de pelo menos um composto azo, um peróxido e um agente de reticulação interna, a quantidade utilizada de agente de reticulação interna no momento da polimerização de uma primeira etapa é ajustada para cair no intervalo de 0,015 a 0,150 mmol por mol de o monômero etilenicamente insaturado solúvel em água utilizado no momento da polimerização da primeira etapa e a polimerização é realizada de tal modo que a área de superfície BET específica das partículas secundárias formadas por aglomeração de partículas primárias obtidas é controlada. With respect to water-absorbing resins, a method of making a water-absorbent resin is provided which has an appropriate specific BET surface and a water-absorbing rate and a water-absorbing agent and an absorbent article which are formed using the water-absorbing resin. In a first aspect of the present invention, when the reverse phase suspension polymerization of two or more steps is carried out in an ethylenically unsaturated water-soluble monomer in a hydrocarbon dispersion medium in the presence of at least one azo compound, a peroxide and an internal cross-linking agent, the amount of internal cross-linking agent used at the time of first stage polymerization is adjusted to fall in the range of 0.015 to 0.150 mmol per mol of the water soluble ethylenically unsaturated monomer used at the time of the first polymerization step and polymerization is carried out in such a way that the ...

Water-absorbent resin and method of producing water-absorbent resin

Provided is a method of producing a water-absorbent resin comprising a step of polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent, and a step of performing post-crosslinking, wherein: the step of polymerizing comprises one or more polymerization steps; all the polymerization steps are performed in the presence of both one or more azo based compounds and peroxides so that the both are coexistent in the all steps; in each polymerization step, a proportion of the azo compounds is 40-95 mass % relative to an amount of the azo compounds and the peroxides; the water-absorbent resin has a water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption of 20 ml/g or more; and the degree of swelling under a load at 30 minutes is 70%.

Method of manufacturing water-absorbent resin, water-absorbent resin, water-absorbing agent and absorbent article

There is provided a method of manufacturing a water-absorbent resin having an appropriate BET specific surface and a water-absorption rate and a water-absorbing agent and an absorbent article that are formed by using the water-absorbent resin. When reverse phase suspension polymerization of two steps or more is performed on a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium in the presence of at least an azo compound, a peroxide and an internal-crosslinking agent, the used amount of the internal-crosslinking agent at the time of the polymerization of a first step is adjusted to fall within a range of 0.015 to 0.150 mmol per mole of the water-soluble ethylenically unsaturated monomer used at the time of the polymerization of the first step and the polymerization is performed such that the BET specific surface area of secondary particles formed by agglomeration of primary particles obtained is controlled.

Water-absorbent resin and absorbent article

Provided are: a water-absorbent resin which has a better water absorption performance and with which it is possible to improve absorption performance under a load when used in an absorbent material; and an absorbent article using an absorbent material that includes the water-absorbent resin. This water-absorbent resin, obtained by polymerising a water soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent and by post-crosslinking using a post-crosslinking agent, has a water-absorption capacity of physiological saline under a load of 4.14 kPa of 16 mL/g or more, has a mass proportion of particles from 150 to 850 ?m relative to the whole proportion of 85 mass% or more, moreover has a mass proportion of particles from 300 to 400 ?m relative to the whole proportion of 20 mass% or more, and has an absorption capacity elasticity index represented by formula (I) of 68,000 or more. Absorption capacity elasticity index= storage elastic modulus [Pa] x centrifugal retention rate [g/g] ...(I) (Figure 1)

Water-absorbing resin manufacturing method, water-absorbing resin, water-absorbing agent, absorbent article.

Con respecto a las resinas absorbentes al agua, se proporciona un método para fabricar una resina absorbente al agua que tiene una superficie específica BET apropiada y una tasa de absorción de agua y un agente que absorbe el agua y un artículo absorbente que se forman al usar la resina absorbente al agua. En un primer aspecto de la presente invención, cuando la polimerización de suspensión de fase inversa de dos etapas o más se realiza sobre un monómero no saturado etilénicamente soluble al agua en un medio de dispersión de hidrocarburo en presencia de al menos un compuesto azo, un peróxido y un agente reticulado interno, la cantidad usada del agente reticulado interno al momento de la polimerización de una primera etapa se ajusta para caer dentro de un intervalo de 0.015 hasta 0.150 mmol por mol del monómero no saturado etilénicamente soluble en agua usado al momento de la polimerización de la primera etapa y la polimerización se realiza de manera que se controla el área de superficie específica BET de partículas secundarias formada por aglomeración de partículas primarias obtenidas.

Water-absorbent resin and absorbent article

本發明提供一種吸水性樹脂及使用該吸水性樹脂而成的吸收性物品，該吸水性樹脂具有優異的吸水性能，並且，即使在高溫高濕下長期保管的前後，仍能夠抑制著色。 本發明的吸水性樹脂，其是藉由在內部交聯劑的存在下使水溶性乙烯性不飽和單體進行聚合，並且利用後交聯劑進行後交聯來獲得，其中，該吸水性樹脂滿足以下的性質：(A)生理食鹽水吸水能力是55g/g以上，在4.14kPa荷重下的生理食鹽水吸水能力是15ml/g以上，並且殘留單體含量是300ppm以下；(B)黃色度是5.0以下，並且在70℃、90%相對濕度的環境下放置10天後的黃色度的變化率(△YI)是10以下。

Water-absorbent resin and absorbent article

Water-absorbing resin and water-absorbing article

【課題】吸収性物品を構成する吸収体の形成にあたり、吸湿状態でも分散性が良く、かつ吸収性物品の製造時のトラブルの発生を防いで効率的に製造することを可能にする吸水性樹脂及びその吸収性樹脂を含む吸収体を用いた吸収性物品を提供する。【解決手段】本発明に係る吸水性樹脂は、水溶性エチレン性不飽和単量体を重合させ、かつ後架橋剤で後架橋することにより得られる吸水性樹脂であって、以下の要件を満たすことを特徴とする吸水性樹脂である。（Ａ）黄色度が５．０以下（Ｂ）ゲル強度が１８００Ｐａ以下【選択図】なし

Method of producing water-absorbing resin

Water-absorbent resin particles

Water-absorbent resin and absorbent article

Provided are: a. water-absorbent resin which, when used as an absorbent material, retains a high water-absorption performance, increases the diffusivity of a to-be-absorbed liquid and makes it possible to effectively decrease the amount of re-wet; and an absorbent article formed using an absorbent material including the water-absorbent resin. The water-absorbent resin according to the present invention is a water-absorbent resin obtained by polymerizing a water-soluble ethylenically monomer in the presence of an internal- crosslinking agent and thereafter post- crosslinking the polymer with a post- crosslinking agent, characterized in that when subjected to a liquid flow test, the water-absorbent resin has an effective absorbent material index (K} indicated by equation (I) of 250 or greater. Effective absorbent material index {K) ? [(the amount of liquid flow} (g}] x [ (artificial-urine absorption ratio} {g/g}] {I} FIGURE 2

Water-absorbent resin particle