C08F6/00

Method for producing water-absorbing polymer particles with high swelling rate and high centrifuge retention capacity with simultaneously high permeability of the swollen gel bed

A process for producing water-absorbing polymer particles having high free swell rate and high centrifuge retention capacity with simultaneously high permeability of the swollen gel bed by polymerization of an aqueous monomer solution in a polymerization reactor having at least two shafts (kneaders) which rotate in an axially parallel manner, subsequent extrusion at high temperatures and thermal surface postcrosslinking.

Method of purifying polyolefin

Provided is a method of purifying polyolefin, the method including the step of contacting linear low-density polyethylene synthesized by a gas phase polymerization reaction with a purge gas containing an ethylene gas and an inert gas in a purge bin. According to this purification method, residual alkene monomers with high carbon numbers may be removed in a simpler and more efficient manner.

Coating to cool a surface by passive radiative cooling

Disclosed herein in is a radiative cooling formulation including a first component with >55% reflectance in a wavelengths range of 0.3 to 2.5 microns, a second component with a first thermal emissivity peak value greater than 0.85 at a first wavelength in a range of 8 to 13 microns (μm), and a third component to mechanically bind together a mixture of the first component and second component.

Method for producing purified fluoropolymer

Provided is a method for producing a purified fluoropolymer containing less fluoridable end groups. The production method includes: (a) melting a fluoropolymer to give a molten fluoropolymer; (b) reducing a reaction inhibitor in the molten fluoropolymer; (c) bringing the molten fluoropolymer into contact with an active substance after the step (b); and (d) removing a volatile matter from the molten fluoropolymer after the step (c).

METHOD FOR PRODUCING FLUORINATED POLYMER PARTICLES

To provide a method capable of producing fluorinated polymer particles in which formation of fine particles or formation of large aggregates is sufficiently suppressed even in the case of a fluorinated polymer having high solubility in a solvent.

The method comprises the following steps (i) and (ii), being a method for producing particles of a fluorinated polymer (A) which has either one or both of structural units (u1) derived from tetrafluoroethylene and structural units (u2) having no sulfonic acid type functional group and having a cyclic structure and fluorine atoms, and which has structural units (u3) having a sulfonic acid type functional group, wherein the proportion of the structural units (u1) is from 0 to 82 mol % in all structural units (100 mol %) in the fluorinated polymer (A): (i) a step of preparing solution or dispersion of the fluorinated polymer (A) having the above fluorinated polymer (A) dissolved or dispersed in a solvent (B), wherein the following conditions (i-1) and (i-2) are satisfied: (i-1) the solvent (B) contains a good solvent (B2) wherein the solubility of the fluorinated polymer (A) is at least 30%, (i-2) even when the above solution or dispersion of the fluorinated polymer (A) is passed through a filter of 200 mesh made of stainless steel, no residue remains on the filter, (ii) a step of mixing the above solution or dispersion of the fluorinated polymer (A) and a solvent (C) to aggregate the fluorinated polymer (A) to form particles of the fluorinated polymer (A), wherein the following conditions (ii-1) to (ii-3) are satisfied: (ii-1) the solvent (C) contains a poor solvent (C1) whereby the degree of swelling of the fluorinated polymer (A) is at most 100%, (ii-2) the degree of swelling of the fluorinated polymer (A) by a mixed solvent (BC) of the solvent (B) and the solvent (C) is from 70 to 250%, (ii-3) the ratio of the mass (W.sub.C) of the solvent (C) to the mass (W.sub.B) of the solvent (B) is from 1 to 5.

AQUEOUS COATING COMPOSITIONS

The invention relates to an aqueous pigmented coating composition containing at least one polymer P1 in the form of an aqueous polymer dispersion, and at least one water-soluble polymer P2 that is composed of ethylenically unsaturated monomers M and contains at least 30% by weight of polymerized N-vinylpyrrolidone in relation to the total amount of monomers M. The invention further relates to the use of the aqueous pigmented coating compositions of the invention for coating tannin-containing substrates, a coating method, and the coated substrates.

Paraffin mixture and method for producing same
09745231 · 2017-08-29 · ·

The present invention provides a paraffin mixture that is suitable for use as cosmetics and cleansing oil for skin and hair and has excellent volatility. The paraffin mixture according to the present invention is a mixture that contains isoparaffin having a carbon number of 12 to 16, and the mixture has a boiling point range of 185° C. to 215° C. and has the content of 2,2,4,6,6-pentamethylheptane at less than 10 mass %.

Polymerisation process and polymerisation unit comprising a degassing section

Polymerization unit for producing polymer powder having at least one polymerization reactor for the polymerization of light (co)monomer(s) having less than 7 carbon atoms, and heavy comonomer(s) having at least 7 carbon atoms, and a degassing section including two (and optionally a third) cylindrical degassing vessels in series. Light (co)monomer(s) are degassed in the first degassing vessel (V1) and recovered, and heavy comonomers are degassed in the second degassing vessel (V2) and recovered. The active polymer powder is optionally polished and/or optionally deactivated in the optional third degassing vessel (V3). The cross-sectional area (S2) of the second degassing vessel is greater than 1.5 times the cross-sectional area (S1) of the first degassing vessel [S2>1.5×S1], and vessels V1 and V2 are equipped with a vent recovery unit (VR) for respectively recovering the light (co-)monomer(s) (VR1) and the heavy comonomer(s) (VR2) from the gases exiting the vessels.

Process for preparing polypropylene with improved recovery
20220306774 · 2022-09-29 ·

Described herein is a process for producing a propylene copolymer in at least a pre-polymerization stage, a first and a second reaction stage connected in series with improved monomer recovery, wherein a product stream, comprising a propylene polymer mixture, unreacted propylene, unreacted ethylene and hydrogen, if present, is separated in a separation unit into a first overhead stream and a first bottom product stream, wherein the desired propylene polymer mixture is recovered from the first bottom product stream. The first overhead stream is at least partially condensed, passed to a distillation column and separated into a second overhead stream and a second bottom product stream. The second overhead stream is at least partially condensed and split into three distinct streams, wherein a distillation reflux stream is returned into the distillation column, a first recycle stream is passed to the second reaction stage and a second recycle stream is passed to a stripping column from where a third bottom product stream is withdrawn and at least a part of it is passed to a propylene feed vessel, to the pre-polymerisation stage, to the first reaction stage, or to a combination thereof. Further disclosed is a polymerization unit, particularly suitable for carrying out the inventive process.

METHOD OF PREPARING SUPERABSORBENT POLYMER
20170226248 · 2017-08-10 · ·

A method of preparing a superabsorbent polymer is provided. The method of preparing the superabsorbent polymer according to the present disclosure is able to provide the superabsorbent polymer having an improved absorption rate while having superior centrifuge retention capacity (CRC) and absorbency under pressure (AUP).