Abstract:
The invention relates to a process for preparing an aqueous polymer dispersion for removable pressure-sensitive adhesive films by means of free-radically initiated aqueous emulsion polymerization of one or more ethylenically unsaturated monomers from the group consisting of esters of acrylic acid and methacrylic acid with branched or unbranched alcohols having 1 to 12 carbon atoms, vinyl esters of branched or unbranched carboxylic acids having 1 to 12 carbon atoms, vinyl-aromatics, vinyl halides, olefins and dienes, which comprises copolymerizing from 0.01 to 2.0% by weight of polar, ionic or nonionic comonomers or mixtures thereof, and if polar ionic comonomers, alone or in a mixture, are copolymerized, the proportion thereof is not more than 1.0% by weight, and the amounts in % by weight are based in each case on the overall weight of the comonomers.
Abstract:
The invention relates to adhesive compositions for gluing wood containing aqueous vinyl ester graft copolymer dispersions and water-soluble acid metal salts or free acids, in which the adhesive compositions exhibit outstanding resistance to hot water and have high storage stability. The vinyl ester graft copolymer comprises from 2 to 12 percent by weight, based on the total weight of the graft copolymer, of one or more polyvinyl alcohols having a degree of hydrolysis of from 60 to 99 mol persent and 88 to 98 percent by weight, based on the total weight of the graft copolymer, of a grafting monomer mixture. The grafting monomer mixture contains from 5 to 50 percent by weight, based on the total weight of the monomer mixture, of vinyl esters of saturated, highly branched aliphatic monocarboxylic acids having 9 or 10 carbon atoms, vinyl pivalate, diisopropyl maleate, diisopropyl fumarate, vinyl chloride and mixtures thereof.
Abstract:
The invention relates to a paper composite material with repulp-resistant adhesive coating, consisting of a paper carrier and an adhesive layer, characterized in that an intermediate coat of a dispersion polymer film containing a protective colloid and/or an emulsifying agent and with a glass transition temperature Tg of −20° to 40° is applied between the paper carrier and the adhesive coating. The invention also relates to a method for the production of paper composite material with repulp-resistant adhesive coating.
Abstract:
The present invention relates to a vinyl acetate based polymer latex composition obtained by emulsion polymerization, the polymer comprising PVOH, and a monomer mixture, said monomer mixture comprising vinyl acetate, and a pre-crosslinking monomer selected from one or more polyethylenically unsaturated compounds wherein said pre-crosslinking monomer is present in amount of less than 0.01% by weight based on the total monomer content and which pre-crosslinking monomer is initially charged to the polymerization reaction mixture. The invention further relates to use of the vinyl acetate based polymer latex in an adhesive, preferably a woodworking adhesive and to an adhesive, preferably a woodworking adhesive comprising said latex.
Abstract:
Redispersible tackifier powder compositions which are redispersible in water are provided and which are comprised of one or more tackifying substances and from 2 to 50% by weight of one or more water-soluble low molecular weight homo or copolymers of olefinically unsaturated mono or dicarboxylic acids or their anhydrides. The copolymers also contain other free-radically polymerizable monomers. Antiblocking agents can also be present. Adhesives containing the compositions are also provided.
Abstract:
Pressure-sensitive adhesives which contain preferably from 60% to 85% by weight of graft copolymers for use as polymeric pressure-sensitive adhesives, and from 15% to 40% by weight of plasticizers such as phthalate or phosphate plasticizers. The graft copolymer consists of from 5% to 30% by weight of a graft base and from 70% to 95% by weight of grafted-on monomer units. The graft base is a copolymer with from 40% to 85% by weight of ethylene units and from 15% to 60% by weight of vinyl acetate units and optionally up to 10% by weight of monomer units of other unsaturated compounds. It may be replaced wholly or partially by other graft bases. The grafted-on monomer units consist of from 30% to 80% by weight of units of vinyl esters of short-chained carboxylic acids, especially vinyl acetate, from 20% to 70% by weight of units of vinyl esters of relatively long-chained carboxylic acids, for example vinyl laurate, and/or units of esters of .alpha.,.beta.-unsaturated carboxylic acids with relatively long-chained alcohols and/or units of esters of unsaturated dicarboxylic acids with relatively long-chained alcohols, from 0.5% to 15% by weight of N-vinyl-2-pyrrolidone units and from 0 to 20% by weight of other olefinically-unsaturated copolymerizable monomer units.
Abstract:
The present invention elates to a vinyl acetate based polymer latex composition obtained by emulsion polymerization of: (a) polyvinyl alcohol, (c) a monomer mixture comprising vinyl acetate, and (d) optionally one or more additional co-monomer(s), in presence of (c) 0.0001-0.05 wt. % of a chain transfer agent, based on total monomer weight, said vinyl acetate based polymer latex composition having a weight average particle size ≧400 nm and a higher shear thinning factor than the vinyl acetate based polymer latex composition (a), (b) and (d) obtained in the absence of the chain transfer agent (c). According to one embodiment, emulsion polymerization is carried out in presence of 0.001 to 0.05 wt. % of a chain transfer agent selected from the group consisting of aldehydes and chain transfer agents having a similar chain transfer constant with regard to vinyl acetate as the monomer. According to another embodiment, emulsion polymerization is carried out in presence of 0.0001 to 0.01 wt. % of a chain transfer agent selected from the group consisting of thiols, mercapto acids, and chain transfer agents having a similar chain transfer constant with regard to vinyl acetate as the monomer. The invention also relates to an adhesive comprising said vinyl acetate based polymer latex composition. Such adhesive is preferably used in paper and packaging applications or as a wood working adhesive or wood glue. The invention further relates to a process of manufacture of a vinyl acetate based polymer latex composition having a weight average particle size >400 nm, including emulsion polymerization of vinyl acetate in the presence of polyvinyl alcohol, optionally together with one or more additional co-monomer(s), wherein the emulsion polymerization is carried out in the presence of 0.0001 wt. % to 0.05 wt. % chain transfer agent, based on total monomer weight.
Abstract:
The invention provides low-emission adhesives based on an aqueous, protective-colloid-free polymer dispersion or water-redispersible dispersion powders, obtainable therefrom, of vinyl acetate-ethylene copolymers, obtainable by free-radically initiated emulsion polymerization, in aqueous medium and in the presence of one or more emulsifiers, of a comonomer mixture comprising a) from 5 to 50% by weight of ethylene, b) from 20 to 80% by weight of at least one vinyl ester from the group of vinyl esters of unbranched or branched carboxylic acids having 1 to 9 carbon atoms whose homopolymers have a glass transition temperature Tg >0° C., c) from 5 to 70% by weight of at least one vinyl ester from the group of vinyl esters of branched carboxylic acids having 8 to 13 carbon atoms whose homopolymers have a glass transition temperature Tg
Abstract:
The invention provides a redispersible polymer powder based on a mixture of water-insoluble polymer and a water-soluble atomized protective colloid which can be de-activated through a pH change. In addition, the invention concerns aqueous dispersions that can be prepared with the polymer powder and the use of the polymer powder or its aqueous dispersions as a bonding agent in adhesives, plasters or paints.
Abstract:
A copolymer having good properties for use as a pressure-sensitive adhesive from an aqueous dispersion comprising:(a) from 10% to 30% by weight of ethylene units,(b) from 29% to 69% by weight of acrylic ester units,(c) from 20% to 55% by weight of vinyl acetate units,(d) from 0.2% to 8% by weight of (meth)acrylamide units, and(e) from 0 to 12% of other olefinically-unsaturated monomer units copolymerizable with the above,said copolymer having a glass transition temperature of from -20.degree. C. to -60.degree. C. and a K-value according to Fikentscher, measured in tetrahydrofuran, of from 50 to 180; as well as processes to make the same and aqueous dispersions of the same for use as pressure-sensitive adhesives.