Abstract:
Aqueous polymer dispersions based on copolymers of vinyl aromatics and conjugated aliphatic dienes having a mean particle size of from 80 to 150 nm, obtainable by free radical emulsion copolymerization of (a) from 19.9 to 80 parts by weight of at least one vinyl aromatic compound, (b) from 19.9 to 80 parts by weight of at least one conjugated aliphatic diene, (c) from 0.1 to 10 parts by weight of at least one ethylenically unsaturated acid and (d) from 0 to 20 parts by weight of at least one other monoethylenically unsaturated monomer, the sum of the parts by weight of the monomers (a), (b), (c) and (d) always being 100, in an aqueous medium in the presence of at least one degraded starch having an intrinsic viscosity of less than 0.07 dl/g with the use of at least 0.9% by weight, based on the monomers used altogether, of initiators selected from peroxodisulfates, peroxosulfates, azo initiators, organic peroxides, organic hydroperoxides and hydrogen peroxide, at least 30% by weight of the initiators being initially taken together with the degraded starch in the aqueous medium and the monomers and the remaining initiators being metered into this initially taken mixture under polymerization conditions. Process for the preparation of these dispersions by emulsion polymerization of the monomers (a), (b), (c) and, if appropriate, (d) in the presence of a degraded starch having an intrinsic viscosity ηi of less than 0.07 dl/g, a part of the initiator being initially taken together with the aqueous solution of the degraded starch in the reactor and the remaining initiator and the monomers being metered in under polymerization conditions, and the use of the aqueous polymer dispersions as a binder, adhesive, size for fibers or for the production of coverings.
Abstract:
Paper coating slips comprising at least one pigment and A) an aqueous polymer dispersion obtainable by emulsion polymerization (emulsion polymer for short) and B) a polysilicic acid dissolved or dispersed in water or dispersed silica (summarized as silica sol).
Abstract:
Paper coating slips comprising a) one or more binders b) if appropriate, a thickener c) if appropriate, a fluorescent or phosphorescent dye, in particular as an optical brightener d) pigments or fillers e) further assistants, e.g. leveling agents or other dyes, wherein at least 40% by weight of the total amount of the binders a) comprise a synthetic, water-soluble, anionic polymer (anionic polymer for short) and less than 50% by weight of the total amount of the binders a) are emulsion polymers.
Abstract:
A process for the preparation of aqueous polymer dispersions is described, a vinylaromatic compound, such as, for example, styrene, a conjugated aliphatic diene, such as, for example, butadiene, and an ethylenically unsaturated carbonitrile, such as, for example, acrylonitrile, being copolymerized in an aqueous medium. The copolymerization is effected in the presence of a degraded starch and of free radical initiators. At least part of the monomers differing from ethylenically unsaturated carbonitriles are polymerized before the ethylenically unsaturated carbonitriles are added to the polymerization mixture.
Abstract:
Described is an aqueous polymer dispersion comprising a chain growth addition polymer obtainable by free-radically initiated emulsion polymerization of ethylenically unsaturated, free-radically polymerizable monomers, wherein the polymerization of the monomers is effected in the presence of a certain molecular weight regulator composition. The molecular weight regulator composition comprises at least one mercaptoalkylcarboxylic ester of a C2- to C4-carboxylic acid and at least one oligomeric compound of the formula R1—X-(A-S—)n-A-Y—R2, where R1 and R2 are each H or CH3—(CH2)0-2—C(═O)—, X and Y are each an oxygen atom or a sulfur atom, A is a divalent C1- to C18-alkylene group and n is from 1 to 8. Also described is a process for preparing the aqueous polymer dispersion. The polymer dispersion is useful as a binder, an adhesive, a sizing agent for fibers, in the manufacture of coatings or in the manufacture of paper coating slips.
Abstract:
A process for the preparation of aqueous polymer dispersions is described, a vinylaromatic compound, such as, for example, styrene, a conjugated aliphatic diene, such as, for example, butadiene, and an ethylenically unsaturated carbonitrile, such as, for example, acrylonitrile, being copolymerized in an aqueous medium. The copolymerization is effected in the presence of a degraded starch and of free radical initiators. At least part of the monomers differing from ethylenically unsaturated carbonitriles are polymerized before the ethylenically unsaturated carbonitriles are added to the polymerization mixture.
Abstract:
Epoxy resins with urethane groups, containing on average per molecule from 0.5 to 5 groups of the formula I ##STR1## where the substituents R.sup.1 and R.sup.2 are C.sub.1 -C.sub.8 -alkyl groups, which may also be linked together to form five- or six-membered rings, which may contain an oxygen atom, or are each phenyl, are useful in electrocoating.
Abstract:
A process for the preparation of aqueous polymer dispersions is described, a vinylaromatic compound, such as, for example, styrene, a conjugated aliphatic diene, such as, for example, butadiene, and an ethylenically unsaturated carbonitrile, such as, for example, acrylonitrile, being copolymerized in an aqueous medium. The copolymerization is effected in the presence of a degraded starch and of free radical initiators. At least part of the monomers differing from ethylenically unsaturated carbonitriles are polymerized before the ethylenically unsaturated carbonitriles are added to the polymerization mixture.
Abstract:
Described are aqueous polymer dispersions and methods of making them. The polymer dispersions are obtainable by free-radically initiated emulsion polymerization of 19.9 to 80 parts by weight of vinylaromatic compounds, 19.9 to 80 parts by weight of acrylate monomers selected from C1-C10 alkyl acrylates and C1-C10 alkyl methacrylates, 0.1 to 10 parts by weight of ethylenically unsaturated acids, and 0 to 20 parts by weight of other ethylenically unsaturated monomers, wherein the emulsion polymerization is effected in an aqueous medium in the presence of free-radical initiators, seed latex and also at least one carbohydrate compound in the form of a degraded starch. The polymer dispersions are particularly useful in the manufacture of paper coating slips.
Abstract:
An arylcyclohexene-free or low-arylcyclohexene aqueous polymer dispersion and processes for the preparation thereof by free radical emulsion polymerization from at least three different monomer types are described. A monomeric vinylaromatic compound, a monomeric conjugated aliphatic diene and a monomeric ethylenically unsaturated acid are copolymerized in an aqueous medium in the presence of a mercaptoalkylcarboxylic acid ester of a C2- to C4-carboxylic acid and without alkyl mercaptan as a molecular weight regulator. The polymer dispersion can be used as a binder, adhesive, size for fibers, for the production of coverings or for the preparation of paper coating slips.