摘要:
A process for the production of an emulsion polymerization aqueous copolymer dispersion with a solids contents of 45-55% by weight of(a) 75 to 95 parts by weight of acrylic acid and/or methacrylic acid alkyl esters of 1 to 10 carbon atoms of which 20 to 80% by weight have a water solubility of at most 2 g/l and 20 to 80% by weight a water solubility of at least 10 g/l(b) 5 to 25 parts by weight of a mixture of ethylenically-unsaturated, functional and water-soluble monomers, 25 to 100% by weight thereof consisting of unsaturated carboxylic acids.(c) 500 to 1700 parts by weight of a mixture of 70 to 100% by weight of vinyl chloride, 0 to 30% by weight of at least one vinyl ester of saturated carboxylic acids of 2 to 18 carbon atoms and 0 to 1.5% by weight of a poly-unsaturated monomer which possesses a water solubility of at most 5 g/l, and(d) Ethylene with radical initiators in the presence of emulsifiers and optionally other common additives, characterized in that (1) the components (a) and (b) together with 500 to 1000 parts by weight of water and 0.5 to 10 parts by weight of emulsifier are charged at a pH value of 2 to 4 in an autoclave, and their polymerization is begun at a temperature of 50.degree. to 80.degree. C. by addition of an initiator, (2) the component (c) is metered in in the form of an aqueous emulsion as soon as components (a) and (b) are reacted at least 50% and at most 99%, (3) during the metering phase a pH value of 4.5 to 6.5 is maintained, (4) an ethylene pressure of 40 to 80 bars is built up at the time indicated in (2) and (5) before start of polymerization or at the latest at the time indicated in (2) 10 to 50 parts of an inert organic substance having a water solubility of 10.sup.-3 to 200 g/l and a molecular weight of at most 1000 are added.
摘要:
Novel pressure-sensitive aqueous adhesive dispersions comprising 40 to 65% by weight, based on the dispersion weight, of a copolymer produced by radical emulsion polymerization of ethylene, vinyl esters of saturated carboxylic acids of 2 to 12 carbon atoms, ethylenically unsaturated carboxylic acids, ethylenically unsaturated hydroxyalkyl functional compounds, optionally present (meth)acrylic acid esters with alkyl of 4 to 12 carbon atoms and optionally present mono- or poly-ethylenically unsaturated compounds having a second order transition temperature of -20.degree. to -60.degree. C. and a K value of 50 to 180, characterized in that the copolymer was obtained by polymerization of(a) 10-45% by weight of ethylene(b) 0-25% by weight of acrylic ester(s)(c) 40-89% by weight of vinyl ester(s)(d) 0.5-4% by weight of ethylenically unsaturated carboxylic acids(e) 0.5-10% by weight of ethylenically unsaturated hydroxyalkyl-functional compounds(f) 0-0.3% (meth)acrylamide(g) 0-10% ethylenically unsaturated sulfates and sulfonates or polyethylenically unsaturated compounds, in the presence of 1 to 6% by weight, based on the comonomer mixture, of an emulsifier.
摘要:
A process is provided for the production of a graft copolymer by means of emulsion polymerization. The graft base used is a sulfonate group-containing vinyl ester/ethylene latex which is stabilized exclusively by an anionic emulsifier (CMC.gtoreq.0.5% by weight in H.sub.2 O) and is grafted, preferably with vinyl chloride, without further addition of emulsifier or protective colloid. The graft copolymers according to the invention have good water resistance and very good thermoplastic processability. They are useful as impact modifiers and for the production of articles, such as, soft to semi-hard moldings.
摘要:
A finely-divided, monomodal protective-colloid stabilized aqueous dispersion of a copolymer of at least 75% by weight of units of vinyl chloride and ethylene and optionally copolymerized with up to 25% by weight of units of additional monomers unsaturated at the ethylene bond and having a solids content of 45 to 70% by weight, characterized in that the dispersions are not partially flocculated, the polymer has a mean particle size of 150 to 500 nm measured as mean weight in a disc centrifuge and a polydispersion index of not more than 1.8 and less than 50% of the polymer particles are larger than 1,000 nm and a process for the preparation thereof using a single step radical polymerization of vinyl chloride, ethylene and optionally additional monomers such as vinyl esters useful as dispersion powders, adhesives, binders and concrete additives.
摘要:
Aqueous copolymer dispersions suitable for use in the manufacture of adhesives or as binding agents or as coating substances are produced by the emulsion polymerization of from 1 to 50% by weight of ethylene and from 99 to 50% by weight of vinyl monomers. With the process of the invention, in which, as vinyl monomers, vinyl chloride and, if desired, other ethylenically-unsaturated monomers, for example esters, are used, a higher ethylene content in the copolymer can be obtained at a lower pressure than hitherto. For this purpose, the greater part of the vinyl monomers is metered in and, in addition, an inert organic substance is used.
摘要:
A process for the preparation of finely-divided aqueous copolymer dispersions with a solids content of 10 to 70% by weight, based on the dispersion, comprising emulsion polymerizing (a) 1 to 50% by weight of ethylene and (b) 99 to 50% by weight of at least two ethylenically unsaturated comonomers in the presence of a free-radial initiator and at least one member of the group consisting of emulsifier and a protective colloid and optionally present conventional adjuvants, the ethylenically unsaturataed comonomers being (b1) 79.5 to 99.5% by weight of vinyl chloride, (b2) 0 to 15% by weight of ethylenically unsaturated oil-soluble monomers, (b3) 0.5 to 10% by weight of ethylenically unsaturated, functional, water-soluble monomers and (b4) 0 to 5% by weight of oil-soluble monomers monoethylenically unsaturated and containing functional groups or polyethylenically unsaturated and mixtures thereof with the proviso that the monomers of (b2) and (b4) are copolymerizable with (a) and (b1), the comonomers being initially present in 1 to 40% by weight and the content of the water-soluble monomers being 1 to 35% by weight of the comonomers phase initially present and the rest of component (b) being added as an aqueous emulsion during polymerization and the polymerization is effected at 0.degree. to 120.degree. C. with an ethylene pressure of 10 to 150 bar which is built up at the latest by the point in time at which polymerization of the initial material is complete.
摘要:
A novel process for the preparation of a readily dispersible, pourable dispersion powder comprising emulsion polymerizing in the presence of a free radial initiator a mixture of 1 to 50% by weight of ethylene and 99 to 50% by weight of an ethylenically unsaturated comonomer phase comprising at least one member of the group consisting of (a) 60 to 100% by weight of vinyl chloride, (b) 0 to 40% by weight of monoethylically unsaturated, oil-soluble monomers, (c) 0 to 10% by weight of monoethylenically unsaturated water-soluble monomers having functional groups and (d) 0 to 5% by weight of oil-soluble monomers that are monoethylenically unsaturated and have functional groups or are multiple ethylenically unsaturated and optionally a protective colloid and/or emulsifier at an ethylene pressure of 10 to 150 bar to obtain an aqueous dispersion of a vinyl chloride-ethyelene copolymer, optionally adding to the aqueous dispersion (e) 0 to 40% by weight, based on the VCE-polymer, of at least one water-soluble substance having a T.sub.g .gtoreq.60.degree. C., (f) 0 to 1% by weight, based on the VCE-polymer, of an antifoaming agent, and (g) 0 to 30% by weight, based on the total weight of polymer constituents, of a finely divided antiblocking agent and spray drying or freeze drying the aqueous dispersion to obtain the readily redispersible, pourable powder of a vinyl chloride-ethylene copolymer and the powder produced by the said process and improved coatings, paints, glues and adhesives containing the said redispersible powder.
摘要:
A process for the preparation of aqueous solutions of N-methylol-acrylamide and/or N-methylol-methacrylamide comprising forming a homogeneous mixture of aqueous solution of formaldehyde and aqueous solution of acrylamide and/or methacrylamide and passing the homogeneous mixture through an ion-exchange resin bed based on a styrene-divinylbenzene polymer with tertiary amino groups at an elevated temperature so that the reaction is at least 80% theoretically completed when the mixture issues from the bed, characterized in that the ion exchanger is initially in the form of its free base, the initial temperature and velocity of the homogeneous mixture being adjusted to maintain the bed temperature between 35.degree. and 60.degree. C. and continuing the passage of the homogeneous mixture through the exchanger bed until the bed temperature drops and/or the pH of the exiting solution is below 8.
摘要:
The invention relates to a fast-drying rendering and coating composition comprising a binder in the form of an aqueous polymer dispersion or of a water-redispersible polymer powder, and also an organic precipitant, if desired in combination with an inorganic precipitant.
摘要:
Addition polymers prepared in the presence of condensation-crosslinkable silyl-functional RAFT reagents are preparable in solid or liquid form with low polydispersion.