摘要:
The present invention is a method for producing a water absorbent resin which method is a method for producing surface cross-linked water absorbent resin particles, the method including the successive steps of: (a) adding a surface cross-linking agent and water to a particulate water absorbent resin in a mixer; and (b) reacting the resulting water absorbent resin mixture taken out from the mixer with the surface cross-linking agent in a reactor by heating or active energy ray irradiation, water vapor being used as part or all of the water added in the mixer. This makes it possible to provide a method for producing a water absorbent resin in which method a surface cross-linked water absorbent resin that has excellent properties can be obtained efficiently at low cost with high productivity.
摘要:
A production method of a water-absorbent resin includes the steps of: obtaining a hydrogel by supplying monomer liquid to a reaction device so that the monomer liquid is polymerized; and detaching the hydrogel from the reaction device, wherein the reaction device's surface in contact with the monomer liquid at a position where polymerization occurs is made of a fluororesin having a melt viscosity of less than 1×108 poise at 380° C. On this account, it is possible to obtain a water-absorbent resin having less amounts of an extractable content with high productivity and it is possible to carry out continuous production for an extended period of time.
摘要:
Aqueous liquid and moisture vapor are added to water absorbent resin powder so that particles of the water absorbent resin powder are bound. In forming bound particles by supplying aqueous liquid and moisture vapor to the water absorbent resin powder, the foregoing arrangement makes it possible to supply moisture to whole the powder so that a less amount of particles remains unbound (ungranulated) and increase of a concentration of the water absorbent resin bound particles allows for further improvement of a drying efficiency and makes it possible to obtain particulate water absorbent resin having excellent properties even when the bound particles are highly concentrated. The present invention provides (i) a method for binding water absorbent resin and (ii) a method for producing particulate water absorbent resin which method includes the step of binding particles of water absorbent resin powder. The foregoing effect can be obtained by these methods.
摘要:
A homogeneously surface cross-linked water absorbent resin and a method for the production thereof are provided. The water absorbent material is formed of a surface cross-linked water absorbent resin resulting from granular irregularly pulverized shaped surface cross-linking the product of partial neutralization or whole neutralization of a water absorbent resin having acrylic acid or a metal salt thereof as a main component, which water absorbent material shows a metal atom concentration on the surface of the water absorbent material in the range of 0-10% within 0 second of polishing and 2-35% at 10 seconds value of polishing as determined by subjecting the water absorbent material to Ar ion discharge polishing under a voltage of 500 Å. The surface cross-linked water absorbent resin to be used herein can be produced by surface cross-linking a water absorbent resin having a specific particle diameter with a surface cross-linking agent having a water concentration in a specific range.
摘要:
A method directed to manufacturing porous products by supplying a water-in-oil type high internal phase emulsion into mold elements, shaping and polymerizing the emulsion. It is characterized by a moving shaping unit provided with a lower mold element on one side having a smooth mold face furnished with a depressed part and an upper mold element on the other side having a smooth mold face furnished with a corresponding depressed part forming a cavity of a stereoscopic shape together with the depressed part of the lower mold element. Prior to the union of the two mold elements continuously supplying the emulsion into the two mold elements, transferring the shaping unit into a polymerizing device subsequent to the union of the mold elements, and shaping and polymerizing the emulsion therein.
摘要:
An object of the present invention is to make it possible that: a high-concentration hydrogel sheet, which is suitable for production of high-performance water-absorbent resin particles, is cut efficiently without involving the adhesion to such as cutting-blades; and the subsequent disintegration operation is also successfully carried out; and hydrogel particles excellent in the quality and performances are efficiently produced. As a means of achieving this object, the process according to the present invention for production of hydrogel particles is a process for production of the hydrogel particles 14 from a high-concentration hydrogel sheet 10 and comprises: a step (a) of cutting a continuous sheet 10 of a crosslinked high-concentration hydrogel polymer of 50 to 80 weight % in solid component concentration every 10 to 100 cm lengthwise of the continuous sheet 10 while running it lengthwise, thereby obtaining cut pieces 12; and a step (b) of continuously supplying the cut pieces 12 (obtained from the step (a)) to a continuous disintegrator 40 to continuously carry out disintegration and discharge under conditions where the supply amount of the cut pieces 12 and the disintegrating and discharging abilities of the continuous disintegrator 40 satisfy (supply amount)≦(disintegrating and discharging abilities), thereby obtaining the hydrogel particles 14.
摘要:
This invention provides a method of producing a porous cross-linked polymer by horizontal continuous polymerization of a water-in-oil higher internal phase emulsion (HIPE), which includes using a weir at the opposite end parts in the width direction of an emulsion supporting member for use in the polymerization. This invention also provides a method of producing a porous cross-linked polymer by horizontal continuous polymerization of an HIPE, which includes using a supporting member of the lower side of the emulsion and a sheet material on the upper side of the emulsion, and performing the polymerization by exerting a tensile force in the width direction and/or the travel direction of the sheet material. This invention further provides a method of producing a porous cross-linked polymer by horizontal continuous polymerization of an HIPE, which includes regulating the thickness of the HIPE by passing the HIPE between a movable supporting member and an object disposed so as to retain a prescribed gap from the movable supporting member.
摘要:
A hydrophilic polymer having the water absorption capacity thereof 1 to 30 times to its own weight by a process of manufacture which comprises preparing a monomer component comprising (a) 2 to 25 mol % of a hydroxyl group-containing alpha,beta-ethylenically unsaturated monomer, (b) 5 to 30 mol % of a carboxyl group-containing alpha,beta-ethylenically unsaturated monomer, and (c) 93 to 45 mol % of a carboxylate group-containing alpha,beta-ethylenically unsaturated monomer, providing that the total of (b) and (c) is in the range of 98 to 75 mol %, radically polymerizing said monomer component, and heat-treating the resultant polymer thereby causing the hydroxyl group and carboxyl group possessed by the polymer to react with each other and form a crosslinked structure, a method for the production thereof, and uses found therefor including a cation sequestrating resin, a coolant and a coating material.
摘要:
A method for the production of an aqueous dispersion by the dispersion of an inorganic pigment such as calcium carbonate and aluminum hydroxide in an aqueous medium, which method comprises incorporating in said inorganic pigment as a dispersant a carboxyl group-containing water-soluble polymer possessing a number average molecular weight in the range of 2,000 to 80,000 and/or a water-soluble condensed phosphate and a water-soluble anionic modified polyvinyl alcohol possessing a polymerization degree in the range of 30 to 700, a saponification degree in the range of 30 to 100 mol %, and an anionic modification degree in the range of 0.5 to 20 mol %.
摘要:
A production method of a water-absorbent resin includes the steps of: obtaining a hydrogel by supplying monomer liquid to a reaction device so that the monomer liquid is polymerized; and detaching the hydrogel from the reaction device, wherein the reaction device's surface in contact with the monomer liquid at a position where polymerization occurs is made of a fluororesin having a melt viscosity of less than 1×108 poise at 380° C. On this account, it is possible to obtain a water-absorbent resin having less amounts of an extractable content with high productivity and it is possible to carry out continuous production for an extended period of time.