摘要:
There are disclosed a process for producing a vinyl ester polymer having a high degree of polymerization at a high efficiency, which process comprises subjecting a vinyl ester monomer to seed polymerization by the use of a vinyl ester polymer emulsion as a seed emulsion under the conditions in which the charge of a water-soluble initiator per unit volume (1 liter) of reactant liquid charge is 1.times.10.sup.-8 to 2.times.10.sup.-4 mol, and the charge of the water-soluble initiator per one particle of the vinyl ester polymer particles in the seed emulsion is 1.times.10.sup.-28 to 1.times.10.sup.-20 mol, and a process for producing a vinyl alcohol polymer at a high efficiency from the vinyl ester polymer thus obtained.According to these processes of the present invention, both a vinyl ester polymer and vinyl alcohol polymer each having a higher degree of polymerization can be produced with ease on an industrial scale.
摘要:
There are disclosed a secondary suspending agent for suspension polymerization of a vinyl compound (vinyl chloride, etc.) which comprises an aqueous dispersion comprising as the dispersoid, a polyvinyl ester having a degree of hydrolysis of 60 mol% or less, an average degree of polymerization of 4000 or more and an average particle diameter of 100 .mu.m or less; a suspension stabilizing agent comprising 5 to 70% by weight of the secondary suspending agent (PVA, etc.) and 30 to 95% by weight of a water-soluble high molecular compound having a degree of polymerization of 500 or more, the agent being used for suspension polymerization of a vinyl compound; and a process for producing a vinyl polymer (PVC, etc.) comprising suspension polymerizing a vinyl compound by the use of the above suspension stabilizing agent. Both the agents are well suited for producing vinyl polymer granules enhanced in absorption rate of plasticizer, bulk density, removality of residual monomer and porosity.
摘要:
The present invention relates to an aqueous emulsion comprising a dispersant of a modified polyvinyl alcohol with an ethylene unit content of 2 to 9 mol % and a degree of hydrolysis of at least 95 mol %, a dispersoid of a polymer of an ethylenically unsaturated monomer, and a ratio (.eta.2 rpm/.eta.20 rpm) of Brookfield viscosity at 30.degree. C., 2 rpm (.eta.2 rpm) as against Brookfield viscosity at 30.degree. C., 20 rpm (.eta.20 rpm) being 1 to 1.8 when the latter viscosity (.eta.20 rpm) is adjusted to 5,000 to 10,000 mPa.multidot.S.The aqueous emulsion according to the present invention is excellent in structural viscosity (flowability, high speed application performance), provides coated layers with high water resistance and low-temperature stability, and can be suitably used extensively as an adhesive for paper, wood and plastics, as a binder for impregnated paper and non-woven products, as an additive for mortar, as a paint, and in paper and fiber processings.
摘要:
A coating agent comprising a particulate PVA having an average particle diameter of 0.01 to 1 .mu.m has excellent applicability through blade coaters or roll coaters.
摘要:
Provided are water soluble films comprising a modified polyvinyl alcohol containing 2-pyrrolidone ring. The films have excellent water solubility, which can be maintained over a long period of time and under the condition of being contacted with an alkaline or acid substance, and at the same time have an appropriate touch and flexibility.
摘要:
It is an object of the present invention to provide an aqueous ethylene-vinyl alcohol-based copolymer dispersion which is excellent in long-term storage stability and in film-forming properties even when subjected to low-temperature or short-time drying or applied to give thick coats and can give coatings showing high gas barrier performance. The prevent invention is an aqueous ethylene/vinyl alcohol-based copolymer dispersion, which comprises: (A) an ethylene/vinyl alcohol-based copolymer with an ethylene content of 15-65 mole percent and a degree of saponification of not lower than 80 mole percent, (B) a base-neutralized ethylene/α,β-unsaturated carboxylic acid-based copolymer and (C) a polyvinyl alcohol with a degree of saponification of 75-100 mole percent and a degree of polymerization of 100-3500, the content of the polyvinyl alcohol (C) being 0.5-100 parts by weight per 100 parts by weight of the ethylene/vinyl alcohol-based copolymer (A).
摘要:
It is an object of the present invention to provide an aqueous ethylene-vinyl alcohol-based copolymer dispersion which is excellent in long-term storage stability and in film-forming properties even when subjected to low-temperature or short-time drying or applied to give thick coats and can give coatings showing high gas barrier performance. The prevent invention is an aqueous ethylene/vinyl alcohol-based copolymer dispersion, which comprises: (A) an ethylene/vinyl alcohol-based copolymer with an ethylene content of 15-65 mole percent and a degree of saponification of not lower than 80 mole percent, (B) a base-neutralized ethylene/α,β-unsaturated carboxylic acid-based copolymer and (C) a polyvinyl alcohol with a degree of saponification of 75-100 mole percent and a degree of polymerization of 100-3500, the content of the polyvinyl alcohol (C) being 0.5-100 parts by weight per 100 parts by weight of the ethylene/vinyl alcohol-based copolymer (A).
摘要:
This invention relates to multiphase structured polymer particles comprising at least two rubber component phases (I) formed by copolymerization of monomer mixtures comprising an acrylate ester and a polyfunctional monomer, a thermoplastic resin component phase (II) formed by copolymerization of a monomer mixture comprising a methacrylate ester and other monomers, and satisfying the following conditions (1)-(5). (1) The number average molecular weight of the thermoplastic resin component forming the outermost phase is 30,000 or less. (2) The weight ratio of phase (I)/phase (II) is 30/70-80/20. (3) Of the adjacent phases (1), a specific relation holds regarding the solubility in water of the monomer mixtures forming the nth and n+1th phases. (4) A specific relation holds between the refractive index of phase (I) and the refractive index of phase (II). (5) The average particle size is 150 nm or less. When the multiphase structured polymer particles according to this invention are used alone to form molded products, molded products having excellent transparency and elastic recovery properties can be obtained.
摘要:
A curable resin composition with excellent thermal adhesiveness is constituted of the following components (A) to (C): (A) a thermoadhesive polymer; (B) an ethylenic unsaturated compound polymerizable by active energy radiation; and (C) a polymerization initiator, wherein the relationships represented by the following formulas (1) and (2) are satisfied: 0.1≦(Awt)/{(Awt)+(Bwt)}≦0.6 (1) 0.4≦(Bwt)/{(Awt)+(Bwt)}≦0.9 (2) where (Awt) stands for a compounded amount (parts by weight) of component (A), and (Bwt) stands for a compounded amount (parts by weight) of component (B).