Abstract:
Trioxane homo-or copolymerizate is produced by continuously feeding the liquid starting material to be polymerized into a mixer in which there is present a powdered to granular oxymethylene homopolymer or copolymer which is fluidized to form a fluidized bed, the speed of feeding, catalyst concentration and polymerization temperature are coordinated to each other in suitable manner and after a polymerization reaction of at least 70 percent polymerizate is continuously or cyclically discharged from the mixer serving as reactor.
Abstract:
There is prepared an iodophor solution comprising(a) 0.5 to 3 weight percent iodine,(b) 10 to 30 weight percent phosphoric acid,(c) 5 to 30 weight percent acetic acid, and(d) 0.5 to 20 weight percent of a polymerHaving an average molecular weight between 500 and 10,000 and consisting essentially of repeating units of the general formula ##STR1## where X in 90 to 65% of the cases is COOH, in 10 to 35% of the cases is ##STR2## and in 0 to 10% of the cases is CH.sub.2 OH and/or CN and/or ##STR3## the side chains being distributed statistically at random. The solution is made up with water to 100 weight percent. Preferably there is present hydrogen iodide, alkali metal iodide, alkaline earth metal iodide or ammonium iodide. Also there can be present a wetting agent such as sodium lauryl sulfate or sodium dodecylbenzene sulfonate or sodium dihexylsulfosuccinate.
Abstract:
An accelerator combination is provided for the cross-linking of powder paints containing an acrylic resin containing carboxyl groups and an epoxy resin at elevated temperatures, said accelerator containing, based on the weight of said acrylic resin:(a) 0.05 to 3.0% by weight of at least one compound of the formula LiX, in which X signifies a hydroxyl ion, the anion of hydrochloric acid, hydrobromic acid, or of a saturated or unsaturated aliphatic or aromatic carboxylic acid; and(b) 0.5 to 5.0% by weight of at least one quaternary ammonium compound of the formula ##STR1## in which R.sub.1 signifies a saturated aliphatic radical, R.sub.2, R.sub.3 and R.sub.4 signify the same or different saturated aliphatic radicals, aryl radicals or aralkyl radicals, wherein two of the radicals R.sub.2 to R.sub.4 may be replaced by a group which together with the nitrogen atom forms a saturated heterocylic ring, or all radicals R.sub.2 to R.sub.4 may be replaced by a group which together with the nitrogen atom forms a pyridine ring, and in which Y.sup.- signifies a monobasic inorganic or organic acid anion.
Abstract:
Process for dispersing solid, organic or inorganic colorant particles or mixtures thereof in a system comprised mainly of water by mixing into the aqueous system about 0.05 to 10% by weight of at least one dispersing agent comprising a polymer derived from specified units containing carboxyl, carboxylate, carbonyl and/or hydroxyl groups. A dispersing agent and an aqueous dispersion are provided. The process is particularly useful for dispersing pigments in aqueous systems.
Abstract:
A radiation-hardenable agent for the scratch-resistant coating of organic glasses consists of a cocondensate of vinyl trimethoxysilane or vinyl triethoxysilane and tetramethoxysilane or tetraethoxysilane, a reactive diluent which comprises at least 2 vinyl, acrylic or methacrylic groups per molecule and, if necessary, of a known photoinitiator. The agent can be prepared by forming the cocondensate in the presence of an amount of water which is at least equivalent to the methoxy or ethoxy groups present or in the presence of a small amount of a carboxylic acid, removing all volatile portions of the reaction mixture and mixing the oily siloxane remaining as residue with the other components.
Abstract:
The formaldehyde emission in the thermoplastic processing of antioxidant containing oxymethylene copolymer molding compositions is reduced considerably if these molding compositions additionally contain on the surface or homogeneously mixed in a specifically defined formaldehyde binding material which contains in the molecule at least two 4,6-diamino-1,3,5-triazin-2-yl groups. In this way there are avoided deposits on the die and odor annoyance.
Abstract:
There are prepared powder enamels or varnishes containing an acrylic resin in combination with an aliphatic dicarboxylic acid. The acrylic resin has glycidyl groups and is prepared by bulk polymerizing a mixture of:(a) methyl methacrylate, 20 to 70 weight %;(b) at least one ester of acrylic acid or methacrylic acid with a monohydric alcohol, whose homopolymer has a glass transition temperature below 40.degree. C., 10 to 40 weight %;(c) glycidyl acrylate or glycidyl methacrylate, 10 to 25 weight %; and(d) an additional monomer copolymerizable with (a), (b) and (c), 0 to 50 weight %;in the presence of a radical (free radical) catalyst and in the presence of, based on the weight of the monomer mixture of 0.1 to 3.0 weight percent of at least one ester of phosphorous acid having the formula: ##STR1## where R.sub.1 is hydrogen or a saturated aliphatic group with 1 to 16 carbon atoms, an aryl group with 6 to 10 carbon atoms, an alkyl substituted aryl with 1 to 12 carbon atoms in the alkyl, or an aralkyl group with 7 to 18 carbon atoms and R.sub.2 and R.sub.3 are the same or different saturated aliphatic groups with 1 to 16 carbon atoms, aryl groups with 6 to 10 carbon atoms, alkyl substituted aryl with 1 to 12 carbon atoms in the alkyl, or aralkyl groups with 7 to 18 carbon atoms.
Abstract:
An improved process for the trans-esterification of esters of acrylic or methacrylic acid in the presence of a trans-esterification catalyst and a polymerization inhibitor includes the use of about 0.05 to about 10% by weight of an alkali metal cyanide as the catalyst.
Abstract:
A process for decreasing the hygroscopicity of a polycarboxylate, said process comprising preparing a melt of a composition having a melting point of about 40.degree. - 120.degree. C, said composition giving an acid or neutral pH in an aqueous solution or suspension, said composition being less hygroscopic than said polycarboxylate, said composition capable of being free flowing under equilibrium conditions at about 30.degree. C and in an air atmosphere of at least about 40% relative humidity; heating said melt in a mixer to a temperature of up to about 140.degree. C; gradually adding said polycarboxylate as a powder to said melt while mixing said melt; wherein said composition comprises at least about 3 and at most about 40% by weight of the mixture resulting after all polycarboxylate has been added to said melt.
Abstract:
The suspension polymerization of acrylic acid esters, methacrylic acid esters and vinyl aromatics alone or in admixture with subordinate amounts of other monomers is carried out in the presence of an acrylic or methacrylic acid homo or polymerizate or its alkali metal or ammonium salts as dispersing agent with the addition of an acid ester of phosphoric acid with an alkanol having 1 to 8 carbon atoms. The size of polymerizate beads produced is influenced by this procedure.