Abstract: Provided are a polyvinyl alcohol-based resin having an excellent plugging effect and a plugging agent for underground treatment. A polyvinyl alcohol-based resin is disclosed, in which a degree of swelling (%) when the polyvinyl alcohol-based resin is immersed in water at 40° C. for 30 minutes and a solubility (%) when the polyvinyl alcohol-based resin is immersed in water at 65° C. for 5 hours satisfy the degree of swelling/the solubility?3.0.

Abstract: Disclosed are particulate polyvinyl alcohol-based compositions for use in manufacturing chemical materials and in other industrial operations, and for treatments applied to a subterranean formation traversed by the borehole of an oil or gas well, which compositions are prepared by granulating polyvinyl alcohol polymers, and admixing the granules so produced with powder and/or crushing the granules to a specified particle size distribution.

Abstract: A composition comprises: an at least partially hydrolysed polyvinyl acetate component having an hydrolysation degree of at least 5%; a polyalkylene glycol component having a number average molecular mass Mn lower than 9000 g/mol and consisting of one or more substances selected from the group consisting of polyethylene glycol, polypropylene glycol, copolymers of ethylene glycol and propylene glycol, and their derivatives; a positive or negative electrode active component; and a conductive component; wherein the mass ratio between the at least partially hydrolysed polyvinyl acetate component and the positive or negative electrode active component equals at least 0.12 and at most 0.30, and wherein the mass ratio between the polyalkylene glycol component and the positive or negative electrode active component equals at least 0.012 and at most 0.10.

Abstract: To provide a composition for surface treatment capable of treating a surface of a polished object to be polished having both of a silicon-silicon bond and a nitrogen-silicon bond by sufficiently removing defects on the surface of the polished object to be polished. The composition for surface treatment contains a nonionic water-soluble polymer (A) having a main chain including only a carbon atom or a main chain consisting of a carbon atom and a nitrogen atom, and an anionic water-soluble polymer (B) having a main chain including only a carbon atom and a side chain having a sulfonic acid group or a group having a salt thereof or a carboxyl group or a group having a salt thereof, and being bonded to the main chain including only a carbon atom, and the composition is used for surface treatment of a polished object to be polished containing a silicon-silicon bond and a nitrogen-silicon bond and a pH of the composition is less than 9.0.

Abstract: The polyvinyl alcohol according to the present invention to be used as a dispersant for suspension polymerization for polyvinyl chloride has a degree of saponification of 60 to 80 mol %, a block character of 0.4 to 0.6, an integration value defined by the following (a) of 0.04 to 0.1 and an integration value defined by the following (b) of 0.01 to 0.2 in a 1H-NMR spectrum, and a 0.1% by mass aqueous solution of the polyvinyl alcohol has a UV absorbance at a wavelength of 320 nm of 0.18 or more and less than 0.3. (a) An integration value from 5.42 to 5.62 ppm of a peak or peaks observed at 5.50 to 5.54 ppm when an integration value from 3.65 to 4.05 ppm of a peak or peaks observed at 3.83 to 3.87 ppm is assumed to be 100. (b) An integration value from 5.76 to 5.98 ppm of a peak or peaks observed at 5.86 to 5.90 ppm when an integration value from 3.65 to 4.05 ppm of a peak or peaks observed at 3.83 to 3.87 ppm is assumed to be 100.

Abstract: The present invention relates to a method for the preparation of polymer shells, preferably composed of cellulose or hemicellulose, comprising the steps of dissolving the polymer component in a first solvent, preferably an organic solvent and precipitating the polymer component by contacting the first solution with a second solvent, which second solvent has a polar character, and in which second solvent the polymer component is essentially insoluble, thereby obtaining polymer shells. Moreover, the invention refers to the polymer shells as such, having permeable and responsive properties, as well as various applications comprising such polymer shells within the fields of drug delivery, separation techniques, and inter alia filling material.

Abstract: The present invention provides a highly water-soluble and easy-to-handle dispersion stabilizer for suspension polymerization that meets the following requirements: even if the amount of the dispersion stabilizer for suspension polymerization used for suspension polymerization of a vinyl compound is small, the resulting vinyl resin has high plasticizer absorptivity and is easy to work with; it is easy to remove residual monomer components from the resulting vinyl resin; and the resulting vinyl resin contains fewer coarse particles. The present invention relates to a dispersion stabilizer for suspension polymerization of a vinyl compound. This dispersion stabilizer contains a vinyl alcohol polymer (A) having a degree of saponification of 20 mol % or more and less than 65 mol %, a viscosity average degree of polymerization (P) of 100 or more and less than 600, an aliphatic hydrocarbon group having 6 to 18 carbon atoms at its terminal, and an anionic group in its side chain.

Abstract: A process is disclosed for making a resin emulsion suitable for use in forming toner particles including using a wiped film evaporator for removing residual solvents.

Abstract: Provided is a method of producing a polyvinyl alcohol resin, wherein the impurities in the resin are removed efficiently with a small amount of a washing liquid. A polyvinyl alcohol obtained after a polymerization step (step S1) and a saponification step (step S2) is washed with a washing liquid consisting of methyl acetate: 1 to 40 parts by mass, methanol: 50 to 98.9 parts by mass and water: 0.1 to 10 parts by mass in a washing step (step S3). The solid matter concentration of the slurry containing the washing liquid then is 1 to 30 mass %.

Abstract: Provided is a method and an apparatus for producing a polyvinyl alcohol that can reduce energy consumption without deterioration in quality of the product polyvinyl alcohol. First, one or more vinyl esters are polymerized or a vinyl ester and other copolymerizable monomers are copolymerized to give a polyvinyl ester. Then, a raw saponification solution containing the polyvinyl ester and an organic solvent is fed through a channel 1 and a saponification catalyst-containing solution is introduced into the center of the channel. They are then mixed with static mixers 2 and the mixture 4 is subjected to saponification reaction, as it is placed on a belt 3.

Abstract: Provided are an apparatus for removing residual monomers and a method of producing a polyvinyl alcohol resin that can prevent drift of the organic solvent gas and residual of the polymerization solution on the trays and permits efficient removal of the unreacted monomers from the polymerization solution. An apparatus 1 for removing residual monomers having a column main body and valve trays 2 having multiple gas blowout ports each having openings only in a direction perpendicular to the flow direction of the polymerization solution 4 or openings directed downward in the flow direction of the polymerization solution, which are installed in multiple stages in the column main body is used in a monomer-removing step of removing monomers in a polymerization solution 4 by bringing an organic solvent gas, such as methanol gas, into contact with a polymerization solution 4 obtained from a polymerization reactor 3.

Abstract: To provide a process for producing a fluoroolefin/vinyl alcohol copolymer with sufficiently high productivity and excellent heat resistance, whereby a quality loss by coloration is prevented, and a fluoroolefin/vinyl alcohol copolymer obtainable by such a process. A process for producing a fluoroolefin/vinyl alcohol copolymer, which comprises a polymerization step of copolymerizing a specific fluoroolefin and a vinyl ether having a hydrogen atom of a hydroxy group of a vinyl alcohol substituted with a protective group which can be deprotected, and a deprotection step of substituting the protective group in polymerized units based on the vinyl ether in the copolymer obtained in the polymerization step, with a hydrogen atom to form a hydroxyl group, and the fluoroolefin/vinyl alcohol copolymer obtainable by such a process.

Abstract: Ethanol is produced from methyl acetate by a hydrogenolysis reaction. The methyl acetate is produced as a byproduct during the conversion of a vinyl acetate polymer or copolymer to a polymer or copolymer of vinyl alcohol. By integrating the two processes, a valuable product, i.e. ethanol, is produced from a methyl acetate byproduct.

Abstract: Acetic acid is converted to vinyl acetate monomer by a reaction with oxygen and ethylene. The vinyl acetate is polymerized to form a vinyl acetate polymer or copolymer, which is then reacted in a methanolysis reaction with methanol and base to form a polymer or copolymer of vinyl alcohol and a methyl acetate byproduct. Ethanol is produced from methyl acetate by a hydrogenolysis reaction. The hydrogenolysis reaction also produces methanol. At least a portion of this ethanol is converted to ethylene by a dehydration reaction. At least a portion of the ethylene produced in this dehydration reaction is recycled to react with acetic acid and oxygen to form vinyl acetate. By converting a byproduct and by recycle of compositions, a polymer or copolymer of vinyl alcohol is efficiently produced with minimal waste.

Abstract: The present invention provides a polyvinyl alcohol polymer having excellent water solubility, compared to conventional polyvinyl alcohol polymers, and having a high cloud point even when the polyvinyl alcohol polymer is partially saponified. The present invention is a polyvinyl alcohol polymer having, at its end, a group represented by the general formula (I) and/or having, in its main chain, a group represented by the general formula (II). In the formulae, R denotes a hydrogen atom or an OM group, and M denotes a hydrogen atom, an alkali metal atom, a 1/2 alkaline earth metal atom, or an ammonium group.

Abstract: Ethanol is produced from methyl acetate by a hydrogenolysis reaction. The methyl acetate is produced as a byproduct during the conversion of a vinyl acetate polymer or copolymer to a polymer or copolymer of vinyl alcohol. By integrating the two processes, a valuable product, i.e. ethanol, is produced from a methyl acetate byproduct.

Abstract: Provided are a method and an apparatus for producing a polyvinyl alcohol that can remove unreacted monomers from the polymerization solution efficiently and reduce the amount of methanol injected. A polymerization solution obtained by polymerization of one or more vinyl esters or copolymerization of a vinyl ester with other monomers copolymerizable therewith is adjusted to a particular concentration by addition of liquid methanol and then brought into contact with methanol vapor in counter-current flow for separation into a monomer-free polymer solution and a monomer/methanol mixture. The monomer-free polymer solution is then saponified in the presence of a catalyst to give a polyvinyl alcohol.

Abstract: Provided are an apparatus for removing residual monomers and a method of producing a polyvinyl alcohol resin that can prevent drift of the organic solvent gas and residual of the polymerization solution on the trays and permits efficient removal of the unreacted monomers from the polymerization solution. An apparatus 1 for removing residual monomers having a column main body and valve trays 2 having multiple gas blowout ports each having openings only in a direction perpendicular to the flow direction of the polymerization solution 4 or openings directed downward in the flow direction of the polymerization solution, which are installed in multiple stages in the column main body is used in a monomer-removing step of removing monomers in a polymerization solution 4 by bringing an organic solvent gas, such as methanol gas, into contact with a polymerization solution 4 obtained from a polymerization reactor 3.

Abstract: Provided is a method of producing a polyvinyl alcohol resin, wherein the impurities in the resin are removed efficiently with a small amount of a washing liquid. A polyvinyl alcohol obtained after a polymerization step (step S1) and a saponification step (step S2) is washed with a washing liquid consisting of methyl acetate: 1 to 40 parts by mass, methanol: 50 to 98.9 parts by mass and water: 0.1 to 10 parts by mass in a washing step (step S3). The solid matter concentration of the slurry containing the washing liquid then is 1 to 30 mass %.

Abstract: Provided is a method and an apparatus for producing a polyvinyl alcohol that can reduce energy consumption without deterioration in quality of the product polyvinyl alcohol. First, one or more vinyl esters are polymerized or a vinyl ester and other copolymerizable monomers are copolymerized to give a polyvinyl ester. Then, a raw saponification solution containing the polyvinyl ester and an organic solvent is fed through a channel 1 and a saponification catalyst-containing solution is introduced into the center of the channel. They are then mixed with static mixers 2 and the mixture 4 is subjected to saponification reaction, as it is placed on a belt 3.

Abstract: A method for preparing polyvinyl alcohol and polyvinyl acetate latex by use of a kettle bottom residue from vinyl acetate production process includes: distilling a kettle bottom residue of vinyl acetate to obtain a crude acetic acid and a distillation residue; multiple washing the distillation residue with water under boiling condition to obtain a washing residue containing polyvinyl acetate; dissolving a first portion of the washing residue into a first solvent to obtain a first polyvinyl acetate solution; subjecting the first polyvinyl acetate solution to saponification with an alkali aqueous solution; dissolving a second portion of the washing residue into a second solvent; and dispersing the second polyvinyl acetate solution into the polyvinyl alcohol solution, and optionally recovering the solvent to obtain a polyvinyl acetate latex; or adding the second polyvinyl acetate solution into an emulsion reaction system and optionally recovering vinyl acetate, to obtain a polyvinyl acetate latex.

Abstract: The present invention provides a polyvinyl alcohol polymer having excellent water solubility, compared to conventional polyvinyl alcohol polymers, and having a high cloud point even when the polyvinyl alcohol polymer is partially saponified. The present invention is a polyvinyl alcohol polymer having, at its end, a group represented by the general formula (I) and/or having, in its main chain, a group represented by the general formula (II). In the formulae, R denotes a hydrogen atom or an OM group, and M denotes a hydrogen atom, an alkali metal atom, a 1/2 alkaline earth metal atom, or an ammonium group.

Abstract: There is disclosed a polyvinyl alcohol having a 1,2-glycol bond in a side chain, and a process for preparing the polyvinyl alcolnol wherein there is no generation of dimethyl carbonate hence no need of a process of eliminating dimethyl carbonate in the recovering process of waste liquid after hydrolysis. Also, even when an introduction amount of 1,2-glycol bonds is increased, there is no deterioration of solubility in a hydrolyzing solution (methanol) of a copolymer (paste) before hydrolysis. Further, water-insolubility is not lowered even in experiencing thermal history. Specifically, there is provided a polyvinyl alcohol having a 1,2-glycol bond in a side chain obtained by hydrolyzing a copolymer of a vinyl ester monomer and a compound shown in the formula (1) wherein the hydrolysis degree of the polyvinyl alcohol is at least 60% by mol.

Abstract: An ethylene-vinyl alcohol copolymer and a molded article thereof are disclosed. The ethylene-vinyl alcohol copolymer has improved stretching properties and provides the molded article with excellent gas barrier properties, appearance and strength. The ethylene-vinyl alcohol copolymer comprises the structural unit of formula (1): (wherein X represents any binding chain excluding an ether bond, each of R1 to R4 represents independently any substituent and n represents 0 or 1.).

Abstract: A method for preparing polyvinyl alcohol and polyvinyl acetate latex by use of a kettle bottom residue from vinyl acetate production process includes: distilling a kettle bottom residue of vinyl acetate to obtain a crude acetic acid and a distillation residue; multiple washing the distillation residue with water under boiling condition to obtain a washing residue containing polyvinyl acetate; dissolving a first portion of the washing residue into a first solvent to obtain a first polyvinyl acetate solution; subjecting the first polyvinyl acetate solution to saponification with an alkali aqueous solution; dissolving a second portion of the washing residue into a second solvent; and dispersing the second polyvinyl acetate solution into the polyvinyl alcohol solution, and optionally recovering the solvent to obtain a polyvinyl acetate latex; or adding the second polyvinyl acetate solution into an emulsion reaction system and optionally recovering vinyl acetate, to obtain a polyvinyl acetate latex.

Abstract: Disclosed is an electrode binder for a secondary battery, an electrode including the electrode binder, and the secondary battery. The disclosed electrode binder for the secondary battery includes a polymer whose cohesion force with a metal (loid) electrode active material is equal to or more than 100 gf/cm, and adhesion force with an electrode current collector ranges from 0.1 gf/mm to 70 gf/mm, the metal (loid) electrode active material being capable of reversibly storing and discharging lithium, wherein the polymer includes at least one kind selected from the group including polyamide imide, polyamide, polyacrylonitrile, polyacrylic acid and polyvinyl alcohol.

Abstract: Disclosed is a process for the preparation of poly(vinylbenzyl alcohol) by, for example the hydrolysis of poly(vinylbenzyl acetate) in the presence of a basic catalyst in an organic solvent.

Abstract: A modified polyvinyl alcohol (PVA) protected with a protecting group of the present invention is one wherein an amount of high-molecular weight body components of the modified polyvinyl alcohol having a weight-average molecular weight of 250,000 or more as determined by polyethylene glycol standards according to a gel permeation chromatography is 1000 ppm or less in the modified polyvinyl alcohol. The modified PVA is prepared by removing a metal ion and an acid from the modified PVA such as acetalized PVA with ion exchange treatment and then heat-treating at 80° C. or higher. An auxiliary for fine pattern formation of the present invention comprises the aforementioned modified PVA, a water-soluble crosslinking agent, and water or a mixed solvent of water and a water-soluble organic solvent. The auxiliary for fine pattern formation is applied over a resist pattern 3 and a coated layer 4 is formed thereon.

Abstract: The embodiments provide a temporary vascular embolic agent temporarily blocking the blood vessel in vivo, having appropriate dissolution speed suitable for use in the blood vessel in which blood flow is fast and being more superior in the passing property of a catheter and the controllability of embolization time than conventional one. The embolization of the blood vessel led to cardiac muscle in which blood flow speed is fast is enabled by the temporary vascular embolic agent of the present invention using the pearl like polyvinyl alcohol (PVA) particles having 0.1 to 2% by mol of a 1,2-diol configuration unit and having a saponification degree of at least 99% by mol.

Abstract: A process is provided for the manufacture of polyvinyl alcohol, having an APHA color of equal to or less than about 10, by polymerizing a vinyl acetate monomer to form polyvinyl acetate and then hydrolyzing the polyvinyl acetate to form polyvinyl alcohol wherein the vinyl acetate monomer is characterized as having an inhibitor level of equal to or less than about 10 ppm, preferably less than about 5 ppm, more preferably less than about 3 ppm, even more preferably less than about 1 ppm.

Abstract: Methods of making polymer particles, as well as related particles, compositions, and methods are disclosed.

Abstract: The present invention provides an aqueous emulsion having excellent polymerization stability and standing stability and a redispersible powder. Specifically, the present invention relates to an aqueous emulsion of a polymer obtained by polymerizing an acrylic monomer in the presence of a polyvinyl alcohol containing an acetoacetic ester group; wherein the polyvinyl alcohol containing an acetoacetic ester group has block character [?] of 0.3 to 0.6, hydrolysis degree of at least 97% by mol and acetoacetic esterification degree of 0.01 to 1.5% by mol, and the value obtained by dividing the maximum value by the minimum value of the respective average acetoacetic esterification degree for each of the polyvinyl alcohol containing an acetoacetic ester group separated by particle size of 44 to 74, 74 to 105, 105 to 177, 177 to 297, 297 to 500 and 500 to 1680 ?m is 1.0 to 3.0. Also, the present invention relates to a redispersible fiber obtained by drying the aqueous emulsion.

Abstract: A unique thermoplastic olefin composition having: (a) at least 40 percent by weight of a propylene-alpha olefin copolymer based on the total weight of polymers in the composition, the propylene-alpha olefin copolymer having at least 60 percent by weight units derived from propylene, at least 6 percent by weight units derived from an alpha olefin, a molecular weight distribution less than 3.5, and a broad composition distribution; and (b) at least 20 percent by weight of a polypropylene based on the total weight of polymers in the composition, the polypropylene having at least 93 percent by weight units derived from propylene, a molecular weight distribution of greater than 3.5, a heat of fusion greater than the heat of fusion exhibited by the propylene-alpha olefin copolymer, and a melting point Tmax of at least 120° C.

Abstract: The present invention provides polyvinyl alcohol based (PVA) whose solubility in water varies with a small temperature change to a sufficiently great degree. In manufacturing a polyvinyl alcohol based polymer by: progressing a transesterification reaction of a polyvinyl ester based polymer with alcohol in a liquid reaction mixture including the polyvinyl ester based polymer, the alcohol, and a basic compound; precipitating the polyvinyl ester based polymer, at least a part of which has been transesterified with the alcohol, out of the liquid reaction mixture; and further progressing the transesterification reaction in the liquid reaction mixture including the polyvinyl ester based polymer that has precipitated, the liquid reaction mixture has a temperature of 75° C. to 150° C. when the polyvinyl ester based polymer, at least a part of which has been transesterified, starts precipitating.

Abstract: A photosensitive resin which exhibits excellent storage stability, affinity, miscibility, or solubility with respect to a variety of compounds, and high sensitivity can be solidified even under hydrous conditions as well as exhibiting high cure-related sensitivity and high flexibility and being uniformly solidified even under highly hydrous conditions, a photosensitive resin composition containing the resin, and a novel compound. The photosensitive resin is a saponified poly(vinyl acetate)-based photosensitive resin having a structural unit represented by formula (1): (wherein R1 represents H or Me; R2 represents a linear or branched C2-C10 alkylene group; n is an integer of 1 to 3; X represents m is an integer of 0 to 6; and Y represents an aromatic ring or a single bond).

Abstract: The invention relates to a cross-linked polyvinyl acetal which is characterized in that it can be obtained from at least one polyvinylacetal (1) which is obtained by reacting at least one polymer (A), which contains a) 1,0 to 99.9 wt. % structural units of formula (1), b.) 0 to 99.0 wt. % structural units of formula (2), c.) 0 to 70.0 wt. % structural formula (3), d.) 0.0001 to 30.0 wt. % structural units of formula (4) respectively in relation to the overall weight of the polymer (A), with at least one compound (B) of formula (5). Furthermore, the present invention relates to methods for the production of the polyvinyl acetal according to the invention as well as its use.

Abstract: A process is disclosed for formation of a preformed stabilizer for use in formation of graft polyols. The preformed stabilizer has a reduced level of transesterification products and results in less reactor fouling. The preformed stabilizer is prepared in the presence of phosphorous compounds, which reduces the unwanted transesterification products.

Abstract: A thermoplastic elastomer (“TPE”) which is oxygen-permeable is provided with excellent barrier properties against oxygen by melt-blending with a liquid polyisobutene oil plasticizer in an amount insufficient to render the plasticized elastomer tacky. If made tacky, enough detackifier is used to allow the product to be formed into a removable seal. The TPE may be a conventional thermoplastic vulcanizate or a block copolymer of a vinylaromatic compound, typically styrene, and a conjugated diene, typically butadiene or isoprene, or mixtures thereof; the block may be a diblock, triblock or higher block, but the preferred polyblock copolymer is a triblock with styrene end-blocks and a butadiene/isoprene mid-block. Preferably the diene mid-block is hydrogenated to provide a poly(lower)monoolefin mid-block. When the TPE is a TPV, some or all of the mineral oil used to make the TPV processable may also be substituted with the polyisobutene plasticizer.

Abstract: This invention provides a method for producing a saponified ethylene-vinyl acetate copolymer in which visible imperfections (particularly fish eyes) of the saponified copolymer is inhibited. In this invention, a mixture solution is prepared by adding water to a methanol solution after saponifying an ethylene-vinyl acetate copolymer, and insoluble materials are removed from this mixture solution. Various types of filter or centrifugal separator are used to remove insoluble materials. It is preferable that the weight ratio of methanol to water is from 5:5 to 9:1, the concentration of the saponified copolymer is from 30 to 60 wt %, and the temperature is from 55 to 80° C. This method is particularly suitable for producing a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 70 mol % and a saponification degree of at least 95 mol %.

Abstract: A polyvinyl alcohol having hydrolyzed silyl group functionalized monomer units. The polyvinyl alcohol satisfies the following formulae (I) and (II) and the pH of an aqueous 4% solution of the polyvinyl alcohol is between 4 and 8: 20<P×S<370??(I) wherein P is the viscosity-average degree of polymerization of the polyvinyl alcohol, and S is the content of the silyl group functionalized monomer units in the polyvinyl alcohol, 0.1/100?(A?B)/(B)?50/100??(II) wherein A is the silicon atom content of the polyvinyl alcohol, B is the silicon atom content of the polyvinyl alcohol that has been washed with sodium hydroxide-containing methanol and then washed through Soxhlet extraction with methanol. The polyvinyl alcohol may be readily dissolved in water in the absence of sodium hydroxide or an acid; the aqueous solution has good viscosity stability; the binding force with inorganic substances is high; and a film formed of its mixture with an inorganic substance is excellent in resistance to water.

Abstract: The present invention relates to magnetic, polymeric polyvinylalcohol-based carrier materials. The surface of said materials is at least partially silanised. The invention also relates to a method for silanising the surface of such materials and to the use of the magnetic, silanised carrier materials for isolating biological material, preferably nucleic acids.

Abstract: Difference in retardation between two points separated by 1 cm along the TD direction of a polyvinyl alcohol polymer film 6 is 5 nm or less. The length of a surface for drying a polyvinyl alcohol polymer film 6 is 3 m to 200 m, and the water content of the polyvinyl alcohol polymer film 6 when peeled after passing through the drying surface is 50% by weight or less, in film formation.

Abstract: A method for producing a saponified ethylene-vinyl acetate copolymer (EVOH) comprises: supplying into a second reactor a solution containing the copolymer that is saponified partially with an alkali catalyst under a predetermined pressure in a first reactor; and saponifying further the partially-saponified copolymer in the second reactor under a pressure higher than the predetermined pressure in the first reactor. According to the method, an EVOH having a high saponification degree can be produced efficiently with a small amount of alkali catalyst.

Abstract: Disclosed is a process for preparation of final graft polyols via a continuous process. In, addition, a final graft polyol formed by the process is disclosed. The process includes the steps of reacting a plurality of ethylenically unsaturated monomers and a reaction moderator with a macromer having induced unsaturation in the presence of a carrier polyol, a free radical polymerization initiator, and a first graft polyol. The process provides for the preparation of a final graft polyol having a solids level of from 30 to 70% in a continuous process. The final graft polyol produced by the process has a lower viscosity over a range of solids levels, a reduced amount of very large irregularly shaped particles, a reduced viscosity change in response to a change in reaction temperature compared to a typical graft polyol, a reduced tendency to foul the continuous reactor, and a broader particle size distribution compared to an identical graft polyol prepared by a semi-batch process.

Abstract: The invention provides a novel polyvinyl acetal having N-vinylamide monomer units in the molecule, and provides a binder with the novel polymer for ink or paint and for ceramic forming. Compared with conventional polyvinyl acetals, the novel polymer lowers the solution viscosity and increases the solid content (pigment content) of ink or paint in which the polymer serves as a binder. The binder with the novel polymer for ceramic molding enables production of thin and homogeneous ceramic green sheets of high strength.

Abstract: The present invention provides a new dispersion stabilizer that satisfies, at a high level, the performances required for a dispersion stabilizer used for suspension polymerization. A method of producing a dispersion stabilizer that is useable for suspension polymerization of a vinyl compound and contains a vinyl alcohol polymer (A) includes producing the vinyl alcohol polymer (A) by heat-treating a vinyl alcohol polymer (B) at a temperature of 90 to 180° C. for 0.5 to 20 hours in an atmosphere in which an oxygen concentration is 8000 ppm or lower. The vinyl alcohol polymer (B) has a saponification degree of at least 60 mol % and contains a residual acetic acid group whose block character is in the range of 0.3 to 0.6.

Abstract: The invention relates to silane-modified polyvinyl acetals obtained by acetalizing partially hydrolyzed or fully hydrolyzed vinyl ester polymers having at least 50 mol % of vinyl alcohol units with one or more aldehydes, optionally in the form of their hemiacetals or their acetals, where at least one aldehyde contains hydrolyzable silane groups.

Abstract: A method of producing polyvinyl alcohol polymer, with which a high-strength polyvinyl alcohol polymer with a high degree of saponification can be obtained, the polyvinyl ester saponification process can be linked directly with the spinning process, in which the polyvinyl alcohol polymer is made into fiber, the mole ratio of alcohol with respect to the polyvinyl alcohol can be freely selected, and the concentration of the polyvinyl alcohol obtained by the saponification reaction is high. The polyvinyl alcohol polymer that is obtained by this method exhibits a high block character value and is excellent in randomness is provided, wherein a polyvinyl ester is subject to a saponification reaction in an alcohol-containing organic solvent under the presence of a saponification catalyst and the saponification is carried out while distilling off the carboxylic acid ester that is produced by the saponification reaction.

Abstract: A process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170° C., adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23° or less when the resin pellets are laminated.

Abstract: A process for producing an ethylene-vinyl alcohol copolymer resin, including feeding EVOH into an extruder, keeping the temperature of the melting resin in the extruder at 70 to 170° C., adjusting the amount of water in the extruder so that the water content right after being discharged from the extruder is 5 to 40 weight %, and extruding out the EVOH resin. The extruded EVOH resin is cut into EVOH pellets. Thereby, it is possible to obtain resin pellets in which no spherocrystals are observed in the center of the cross section of the resin when the cross section is observed by the use of a polarization microscope, or no lubricant is contained in the resin pellets, and the angle of repose is 23° or less when the resin pellets are laminated.