摘要:
A coating composition comprises an emulsion copolymer of a monomer mixture comprising at least one vinyl ester, ethylene, and a stabilizing system. The stabilizing system comprises at least one polyvinyl alcohol. The monomer mixture comprises from 60 to 82 wt % of the at least one vinyl ester and from 18 to 40 wt % of the ethylene based on the total weight of monomers in the mixture. The stabilizing system comprises from 1 to 5 wt % of at least one medium molecular weight polyvinyl alcohol and at least one low molecular weight polyvinyl alcohol. The emulsion copolymer has a solids content from 50% to 60% and a viscosity ranges from 500 to 6,000 mPa·s. and a formaldehyde content of less than 10 ppm as determined by HPLC.
摘要:
A vinyl ester/ethylene copolymer is prepared by emulsion copolymerization of a monomer mixture comprising at least one vinyl ester, ethylene, a stabilizing system comprising polyvinyl alcohol and a free radical redox polymerization initiator system comprising i-butyl hydroperoxide as an oxidizing agent and at least one of a sulfuric acid-based compound and erythorbic acid or a salt thereof as a reducing agent. The monomer mixture comprises from 70 wt % to 95 wt % of said at least one vinyl ester and from 5 wt % to 30 wt % of ethylene based on the total weight of monomers in said mixture and the copolymer has a formaldehyde content of less than 5.0 ppmw as determined by ISO-15173.
摘要:
A coating composition comprises an emulsion copolymer of a monomer mixture comprising at least one vinyl ester, ethylene, and a stabilizing system. The stabilizing system comprises at least one polyvinyl alcohol. The monomer mixture comprises from 60 to 82 wt % of the at least one vinyl ester and from 18 to 40 wt % of the ethylene based on the total weight of monomers in the mixture. The stabilizing system comprises from 1 to 5 wt % of at least one medium molecular weight polyvinyl alcohol and at least one low molecular weight polyvinyl alcohol. The emulsion copolymer has a solids content from 50% to 60% and a viscosity ranges from 500 to 6,000 mPa·s. and a formaldehyde content of less than 10 ppm as determined by HPLC.
摘要:
Disclosed are low-formaldehyde aqueous dispersions of vinyl ester/ethylene, e.g., vinyl acetate/ethylene (VAE), copolymers suitable for use in adhesives for applications such as tobacco or food products wherein only very low levels of formaldehyde are permitted. Such dispersions are prepared by emulsion copolymerization of a monomer mixture comprising a vinyl ester, ethylene, a stabilizing system comprising polyvinyl alcohol preferably having a degree of hydrolysis of at least 97 mole %, and a selected type of free radical redox polymerization initiator system. This selected redox initiator system comprises both a water-insoluble oxidizing agent and a sulfuric acid-based reducing agent. The monomer mixture which is polymerized is substantially free of co-monomers which yield free formaldehyde upon drying or curing of the dispersion and is also substantially free of ethylene oxide-containing emulsifiers. The aqueous dispersions resulting from polymerization of this monomer mixture has a solids content in weight percent and a Brookfield viscosity in millipascal-seconds such that the ratio of solids content to the natural logarithm of viscosity ranges from about 6.34 to about 8.25 wt %/ln(mPa·s). The dispersions herein also have a formaldehyde content of less than about 5.0 ppmw as determined by ISO-15173.
摘要:
A vinyl ester/ethylene copolymer is prepared by emulsion copolymerization of a monomer mixture comprising at least one vinyl ester, ethylene, a stabilizing system comprising polyvinyl alcohol and a free radical redox polymerization initiator system comprising i-butyl hydroperoxide as an oxidizing agent and at least one of a sulfuric acid-based compound and erythorbic acid or a salt thereof as a reducing agent. The monomer mixture comprises from 70 wt % to 95 wt % of said at least one vinyl ester and from 5 wt % to 30 wt % of ethylene based on the total weight of monomers in said mixture and the copolymer has a formaldehyde content of less than 5.0 ppmw as determined by ISO-15173.
摘要:
A copolymer dispersion is described comprising a copolymer derived from a monomer mixture comprising: (a) 88.5 to 94% by weight of at least one vinyl ester of a saturated carboxylic acid; (b) 5 to 10.5% by weight of ethylene; (c) 0.5 to 5% by weight of at least one ethylenically unsaturated acid and/or an anhydride thereof and/or a salt thereof; and (d) 0.5 to 5% by weight of at least one ethylenically unsaturated monomer having at least one crosslinkable functional unit. The weight ratio of vinylester units to ethylene units in the copolymer is between 89:11 and 94:6 and the dispersion is stabilized with at least 1% by weight of an emulsifier, wherein the amounts of monomers and emulsifier refer to the total amount of monomers in the copolymer.
摘要:
Disclosed is an aqueous formulation comprising a polymer which is based on a vinyl acetate copolymer, a binder system comprising said aqueous formulation and additionally an aqueous formulation comprising polymer (B). The invention further relates to a fibrous product comprising a fibrous substrate as well as the aqueous formulation or the binder system and use of the aqueous formulation or the binder system for coating synthetic or mineral fibres, for the manufacturing of Eternal Insulation Finishing Systems (EIFS), for increasing the alkali resistance of synthetic or mineral fibres and use in a process for the manufacturing of an alkali resistant glass fibre scrim. Further, the invention relates to a method for the manufacturing of the aqueous formulation.
摘要:
Disclosed are low-formaldehyde aqueous dispersions of vinyl ester/ethylene, e.g., vinyl acetate/ethylene (VAE), copolymers suitable for use in adhesives for applications such as tobacco or food products wherein only very low levels of formaldehyde are permitted. Such dispersions are prepared by emulsion copolymerization of a monomer mixture comprising a vinyl ester, ethylene, a stabilizing system comprising polyvinyl alcohol preferably having a degree of hydrolysis of at least 97 mole %, and a selected type of free radical redox polymerization initiator system. This selected redox initiator system comprises both a water-insoluble oxidizing agent and a sulfuric acid-based reducing agent. The monomer mixture which is polymerized is substantially free of co-monomers which yield free formaldehyde upon drying or curing of the dispersion and is also substantially free of ethylene oxide-containing emulsifiers. The aqueous dispersions resulting from polymerization of this monomer mixture has a solids content in weight percent and a Brookfield viscosity in millipascal-seconds such that the ratio of solids content to the natural logarithm of viscosity ranges from about 6.34 to about 8.25 wt %/ln(mPa·s). The dispersions herein also have a formaldehyde content of less than about 5.0 ppmw as determined by ISO-15173.