Abstract:
A description is given of the use of urea for reducing the amount of energy required to dry paper coated with an aqueous papercoating slip, and/or for reducing the viscosity of papercoating slips. A description is also given of aqueous compositions suitable for use in accordance with claim 1, in the form of aqueous papercoating slips, aqueous, pigment-free binder dispersions, aqueous, binder-free pigment suspensions and aqueous, pigment-free starch solutions containing urea H2N-CO-NH2 in an amount in each case of preferably 1-100% of the maximum amount soluble in the composition in question.
Abstract:
A paper coating slip containing a mineral pigment and an aqueous polymer dispersion as a binder, wherein the polymer dispersion is obtainable by emulsion polymerization of ethylenically unsaturated compounds (monomers) and the paper coating slip gels at above 35° C., i.e. the viscosity of the paper coating slip at from 35 to 60° C. is at least twice the viscosity at 30° C.
Abstract:
A paper coating slip containing a mineral pigment and an aqueous polymer dispersion as a binder, wherein the polymer dispersion is obtainable by emulsion polymerization of ethylenically unsaturated compounds (monomers) and the paper coating slip gels at above 35° C., i.e. the viscosity of the paper coating slip at from 35 to 60° C. is at least twice the viscosity at 30° C.
Abstract:
Aditivo de baño de estucado de papel formado mediante polimerización por radicales libres de a) al menos un monómero de ácido seleccionado de ácidos carboxílicos C3 a C8 etilénicamente insaturados; b) al menos un monómero asociativo de fórmula general H2C>=CR1-COO-(OE)n-(OP)m-R2 en la que R1 es hidrógeno o metilo, n es al menos dos, m es desde cero hasta 50, OE es un grupo óxido de etileno, OP es un grupo óxido de propileno y R2 es un grupo alquilo C8-C30 o un grupo alcarilo C8-C30, c) monómeros copolimerizables no iónicos distintos de a) y b); en el que dicho aditivo tiene un peso molecular promedio en peso inferior a 200.000 y preferiblemente no superior a 150.000, en el que se usa terc-dodecilmercaptano como agente de transferencia de cadena.
Abstract:
Composicion acuosa en forma de un tinte de revestimiento de papel acuoso con un contenido en solidos de al menos un 72 % en peso, conteniendo - al menos un polimero apropiado como ligante para tintes de revestimiento de papel con una temperatura de transicion vitrea Tg de menos de 50 °C, - al menos un 60 % en peso de pigmentos inorganicos, relativo al Contenido total en solidos, - al menos 5 partes en peso de urea, relativo a 100 partes en peso de pigmento y opcionalmente aditivos adicionales.
Abstract:
A paper coating slip additive obtainable by free-radical polymerization, its preparation and its use in paper coating compositions are described. The additive is formed from (a) acid monomers selected from ethylenically unsaturated C3 to C8 carboxylic acids, (b) associative monomers of the general formula H2C=CR1-COO-(EO)n-(PO)m-R2 where R1 is hydrogen or methyl, n is at least two, m is from zero to 50, EO is an ethylene oxide group, PO is a propylene oxide group and R2 is a C8-C30 alkyl group or a C8-C30 alkaryl group, and (c) nonionic copolymerizable monomers other than a) and b), wherein said additive has a weight average molecular weight of below 200 000 and wherein tert-dodecyl mercaptan is used as chain transfer agent.