To provide a water absorbing agent which is excellent in balance between absorbency and liquid permeability against pressure and is excellent in flowability at the time of moisture absorption. The water absorbing agent comprises water absorbent resin particles and an organic surface additive, wherei
To provide a water absorbing agent which is excellent in balance between absorbency and liquid permeability against pressure and is excellent in flowability at the time of moisture absorption. The water absorbing agent comprises water absorbent resin particles and an organic surface additive, wherein: the organic surface additive having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group exists on the surface of the water absorbent resin particle, and the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and a ratio of an oxyalkylene group in a molecular mass of the organic surface additive is 0 or more and 25 mass % or less.
대표청구항▼
1. A water absorbing agent, comprising water absorbent resin particles which are surface cross-linked with a polyhydric alcohol, wherein a compound having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group exists on the surfac
1. A water absorbing agent, comprising water absorbent resin particles which are surface cross-linked with a polyhydric alcohol, wherein a compound having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group exists on the surface of the water absorbent resin particle, and the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and the compound is represented by the following expression, 13≦(an average carbon number of the hydrocarbon group whose carbon number is 8 or more+the number of primary to tertiary amine nitrogen atoms)≦26where the amount of primary, secondary, or tertiary amine nitrogen atoms ≧0,a ratio of an oxyalkylene group in a molecular mass of the compound is 0 mass % or more and 25 mass % or less, and at least part of the reactive group bonds to the functional group of the surface of the water absorbent resin particle and/or bonds to the functional group at the time of water absorption; andwherein the saline flow conductivity of the water absorbent resin particles is 10(×10−7 cm3·s·g−1) or more. 2. The water absorbing agent as set forth in claim 1, wherein the compound is represented by the following expression, 16≦(an average carbon number of the hydrocarbon group whose carbon number is 8 or more+the number of primary to tertiary amine nitrogen atoms)≦24where the amount of primary, secondary, or to tertiary amine nitrogen atoms ≧0. 3. The water absorbing agent as set forth in claim 1, wherein at least part of the reactive group has an ionic bond to the surface of the water absorbent resin particle and/or forms an ionic bond to the surface of the water absorbent resin particle at the time of water absorption. 4. The water absorbing agent as set forth in claim 3, wherein the water absorbent resin particles and the compound or a solution of the compound or a dispersion liquid of the compound are blended at a temperature lower than 100° C. and are kept at a temperature lower than 100° C. 5. The water absorbing agent as set forth in claim 3, wherein the functional group of the surface of the water absorbent resin particle is a carboxyl group. 6. The water absorbing agent as set forth in claim 3, wherein the compound is at least one selected from primary amine, secondary amine, and tertiary amine. 7. The water absorbing agent as set forth in claim 3, wherein the compound includes a hydrocarbon group whose carbon number is 8 or more and an average carbon number of the hydrocarbon group is 13 to 26. 8. The water absorbing agent as set forth in claim 3, wherein the compound is aliphatic amine. 9. The water absorbing agent as set forth in claim 1, wherein at least part of the reactive group covalently bonds to the surface of the water absorbent resin particle, and the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and an average carbon number of the hydrocarbon group is 14 or more. 10. The water absorbing agent as set forth in claim 9, wherein a rate of a reaction of the compound to the water absorbent resin particles is 10% or more and less than 100%. 11. The water absorbing agent as set forth in claim 9, wherein the compound has at least two hydroxyl groups in case where the compound has each hydroxyl group as the reactive group. 12. The water absorbing agent as set forth in claim 9, wherein: in case where the compound has a nitrogen atom, the compound has at least one reactive group and has a hydrophobic group having a hydrocarbon group which bonds to the nitrogen atom and whose average carbon number is 14 or more. 13. The water absorbing agent as set forth in claim 11, wherein the compound is at least one kind selected from aliphatic esterified nonionic surfactants. 14. The water absorbing agent as set forth in claim 12, wherein the compound is at least one kind selected from aliphatic amine, cationic surfactant, and amphoteric surfactant. 15. The water absorbing agent as set forth in claim 1, wherein a mass average particle diameter is 100 μm or more and 600 μm or less and a ratio of particles whose particle diameter is less than 150 μm is 5 mass % or less. 16. The water absorbing agent as set forth in claim 1, wherein the surface of the water absorbent resin particle is cross-linked. 17. The water absorbing agent as set forth in claim 1, wherein an amount of the compound relative to an entire amount of the water absorbing agent is 0.001 mass % or more and 5 mass % or less. 18. A method for producing the water absorbing agent of claim 1, wherein the water absorbing agent comprises water absorbent resin particles, said method comprising the mixing step in which the water absorbent resin particles are mixed with a compound having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group, wherein the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and the compound is represented by the following expression, 13≦(an average carbon number of the hydrocarbon group whose carbon number is 8 or more+the number of primary to tertiary amine nitrogen atoms)≦26,where the amount of primary, secondary, or to tertiary amine nitrogen atoms ≧0,a ratio of an oxyalkylene group in a molecular mass of the compound is 0 or more and 25 mass % or less. 19. The method as set forth in claim 18, wherein at least part of the reactive group has an ionic bond to the functional group of the surface of the water absorbent resin particle and/or forms an ionic bond to the functional group at the time of water absorption, and the mixing step is carried out at a temperature lower than 100° C., and the water absorbing agent is kept at a temperature lower than 100° C. after the mixing step and through completion of production of the water absorbing agent. 20. The method as set forth in claim 19, wherein the mixing step is carried out after a surface cross-linking step in which the vicinity of the surface of the water absorbent resin particle is cross-linked with a surface cross-linking agent. 21. The method as set forth in claim 19, wherein the compound is mixed in a solution or a dispersion liquid. 22. The method as set forth in claim 18, wherein: as said compound, a compound in which at least part of the reactive group has a covalent bond to the surface of the water absorbent resin particle is used, and the water absorbent resin particles and the compound are mixed before and/or during the surface cross-linking, and a temperature at the time of the cross-linking reaction is 120° C. or higher and 240° C. or lower. 23. The method as set forth in claim 22, wherein a polyhydric alcohol which is not equivalent to the compound is mixed at the time of the cross-linking reaction. 24. An absorbent core, comprising the water absorbing agent as set forth in claim 1.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (6)
Staples Thomas L. ; Henton David E. ; Rose Gene D. ; Fialkowski Michael A., Absorbent polymers having a reduced caking tendency.
Gartner Herbert (Baden-Baden DEX) Burgert Josef (Achern-Fautenbach DEX), Surface crosslinked and surfactant coated absorbent resin particles and method of preparation.
Nagashima, Teruhisa; Nakamura, Masatoshi; Watanabe, Yusuke; Nogi, Kozo; Ishizaki, Kunihiko, Particulate water absorbing agent and method for producing the same.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.