摘要:
The invention relates to a method for reducing the amount of residual monomers in aqueous polymer dispersions means of chemical post-treatment. Post-treatment in the aqueous polymer dispersion is carried out by adding a redox system which contains a) 0.005-5 wt. % of an oxidation agent which contains an organic peroxide. and b) 0.005-5 wt. % of a reduction agent which contains sulfinic acids or salts thereof. Additionally the redox system can, optionally, contain catalytic amounts of a polyvalent metallic ion which can be treated in several valent stages. Post-treatment can be carried out at a temperature ranging from 20-100.degree. C. and at a PH-value ranging from 2-9. The invention also relates to the use of the inventive post-treated polymer dispersion for producing adhesives, coatings, powders, constructive chemical products or for refining textiles or paper.
摘要:
The invention relates to a method for reducing the amount of residual monomers in aqueous polymer dispersions means of chemical post-treatment. Post-treatment in the aqueous polymer dispersion is carried out by adding a redox system which contains a) 0.005-5 wt. % of an oxidation agent which contains an organic peroxide. and b) 0.005-5 wt. % of a reduction agent which contains sulfinic acids or salts thereof. Additionally. the redox system can, optionally, contain catalytic amounts of a polyvalent metallic ion which can be treated in several valent stages. Post-treatment can be carried out at a temperature ranging from 20-100° C. and at a PH-value ranging from 2-9. The invention also relates to the use of the inventive post-treated polymer dispersion for producing adhesives, coarings, powders, constructive chemical products or for refining textiles or paper.
摘要:
The invention relates to novel cross-linkable monomers that may be polymerized with ethylenically unsaturated comonomers to form cross-linkable copolymers. Said copolymers may particularly be used in the form of aqueous dispersions as formaldehyde-free adhesives or as coatings with good water resistance. The cross-linkable monomer is a compound in acid or salt form comprising an anion of the formula (I) and one or more cations for producing electrical neutrality, where R1 and R2 represent, independently of one another, hydrogen alkyl, cycloalkyl, aryl, aralkyl, —COOR5, —COO− cat+ or —CON(R6R7), R6 and R7 represent, independently of one another, hydrogen, alkyl, or aryl, cat+ represents a monovalent cation, and one of the groups R1 or R2 may also represent a group —X—R4—CR5(OH)SO3−), wherein X, R4, and R5 assume one of the meanings listed below, R3 represents hydrogen, alkyl, or aryl, X is selected from the group of direct C—C bond, —O—, —CH2—O—, —CH2—NR8—, —COO— or —CONR8—, R8 represents hydrogen, alkyl, or aryl, R4 represents alkylene, polyoxyalkylene, cycloalkylene, or arylene, and R5 represents hydrogen, alkyl, cycloalkyl, or aryl.
摘要:
The invention relates to mineral wool fiber mats, which are stabilized by means of a binder made of polymers funtionalized with epoxy groups and/or with carboxyl groups and selected cross-linking agents. Said mats can be used as an insulating material and are characterized by low or no formaldehyde emissions.
摘要:
The invention relates to a writing, drawing, decorating or cosmetic pencil comprising a colour-delivering, polymer-bonded lead and a polymer-bonded wood substitute material, the wood substitute material at least partly covering or surrounding the lead along its length, there being disposed, between the lead and the wood substitute material, at least one adhesion promoter layer, the lead and the wood substitute material each comprising at least one polymer, the at least one polymer in the lead being incompatible with the at least one further polymer in the wood substitute material, and the at least one adhesion promoter layer coupling on the one hand to the at least one polymer in the lead and on the other hand to the at least one further polymer in the wood substitute material.
摘要:
Polyvinyl alcohol compositions in the form of an aqueous solution are disclosed, where the aqueous polyvinyl alcohol compositions include: (i) polyvinyl alcohol; (ii) at least one polyaldehyde having at least 3 carbon atoms and being masked completely as a water-soluble hydrogen sulfite adduct; and (ii) at least one compound which is acidic in water. The aqueous polyvinyl alcohol compositions are suitable as adhesives and for use in cast films.
摘要:
A redoxcatalyst system capable of being used for free-radical emulsion polymerization of ethylenically unsaturated compounds, comprising at least one oxidizing agent and at least one reducing agent, said reducing agent comprising an at least bifunctional aldehyde having at least 3 carbon atoms which is completely masked as a bisulfite adduct.
摘要:
This invention relates to mineral wool fiber batting that is stabilized or bonded by a binder including polymers containing carboxyl groups and selected cross-linking agents. Said mats can be used as insulating material and are characterized by low formaldehyde emissions or the absence thereof.
摘要:
What are described are alkalified compositions comprising an aqueous dispersion of selected polymers, and comprising selected polyaldehydes as crosslinking agents.From these formulations it is possible to produce coating compositions having a very high blocking resistance and having excellent mechanical properties.
摘要:
The preparation of vinyl ester homo- or copolymers by emulsion polymerization is described. The process is performed in the presence of a polymerization-retarding component in at least two phases, the concentration of the vinyl ester monomer in the polymerization mixture in the first phase having been depleted by not more than 50% at the end of the first phase compared to the concentration of the vinyl ester monomer in the polymerization mixture at the start of the first phase, and the concentration of the vinyl ester monomer in the polymerization mixture in the second phase being depleted compared to the concentration at the end of the first phase. The retarding component is depleted during the first phase. In the second phase, the heat of reaction is removed by evaporative cooling. In the first phase, the emulsion polymerization is effected at temperatures up to the boiling point of the vinyl ester-water azeotrope, and, in the second phase, at temperatures above the boiling point of the vinyl ester-water azeotrope.The process is notable for a short cycle time and high space-time yields and can be operated safely.