Basf Aktiengesellschaft

Basf Se Corporation

Gerhard Auchter

Matthias Gerst

Gerd Rehmer

Bernhard Schuler

Gerhard Neubert

Rolf Osterloh

Johannes T&uuml;rk

Oral Aydin

Thomas Schwerzel

Johannes Dobbelaar

Cornelis Petrus Beyers

Wolfgang H&uuml;mmer

Reinhard B&auml;cher

Helmut Jaeger

Rik Noordijk

Rainer Blum

Eckehardt Wistuba

Dirk Wulff

Gledison Fonseca

Ulrich Filges

Peter Pfoehler

Ulrike Licht

Karl Haeberle

Andreas Boettcher

Roelof Balk

Alexander Wallon

Juergen Barwich

Lothar Franz

Angelika Funhoff

Wolfgang Druschke

Bernhard Schlarb

Alexander Centner

Lothar Maempel

Ralf Fink

Bernd Stanger

Gerald Wildburg

Andreas Otterbach

Horst Seibert

Werner Langer

Alexander Zettl

Hermann Anders

Klaus Vorspohl

R&uuml;diger F&uuml;ssl

Jesper Feldthusen

Andreas Boettchher

Daniel Wilms

Michael Groß

Rüdiger Stark

The present invention relates to aqueous polymer dispersions having a polymer content of at least 55% by weight that are suitable for pressure sensitive adhesives. The invention also relates to a process for preparing these aqueous polymer dispersions and also to the use of the aqueous polymer dispersions in pressure sensitive adhesives and, respectively, pressure sensitive adhesive compositions, especially in pressure sensitive adhesives for transparent substrates, such as plastics labels. The aqueous polymer dispersions have a polymer content of at least 55% by weight, based on the total weight of the dispersion, the polymer being composed of ethylenically unsaturated monomers M and having a glass transition temperature below &#x2212;10&#xb0; C., in which the dispersed polymer particles have a polymodal particle size distribution, in which at least 70% by weight have a particle diameter of below 350 nm.

Process for preparing aqueous polymer dispersions for adhesives

Described is a pressure-sensitive adhesive (PSA) polymer formed from (i) 50%-95% by weight of n-butyl acrylate, (ii) 1%-20% by weight of ethyl acrylate, (iii) 1%-20% by weight of vinyl acetate, (iv) 0.1%-5% by weight of at least one ethylenically unsaturated acid or ethylenically unsaturated acid anhydride, and (v) 0% to 30% by weight of other ethylenically unsaturated compounds different from the monomers (i) to (iv). The PSA polymer can be used for producing self-adhesive articles, more particularly paper labels or film labels.

PSA polymer of N-butyl acrylate, ethyl acrylate, vinyl acetate, and acid monomer

The present invention relates to aqueous polymer dispersions having a polymer content of at least 55% by weight that are suitable for pressure sensitive adhesives. The invention also relates to a process for preparing these aqueous polymer dispersions and the use of the aqueous polymer dispersions in pressure sensitive adhesives and, respectively, pressure sensitive adhesive compositions, especially in pressure sensitive adhesives for transparent substrates, such as plastics labels. The aqueous polymer dispersions have a polymer content of at least 55% by weight, based on the total weight of the dispersion. The polymer is composed of ethylenically unsaturated monomers and has a glass transition temperature below &#x2212;10&#xb0; C., in which the dispersed polymer particles have a polymodal particle size distribution, in which at least 70% by weight of the polymer particles have a particle diameter of below 350 nm.

Aqueous polymer dispersions for adhesives

The invention relates to a method for producing an aqueous polymer dispersion having a polymer solids content of &#x2267;50% by weight by carrying out the radically initiated aqueous emulsion polymerization of ethylenically unsaturated compounds (monomers). The inventive method is characterized in that: a) a mixture is provided in a polymerization vessel and contains a partial quantity 1 consisting of: deionized water, 0.001 to 0.5 parts by weight of a polymer with a weighted average particle diameter of &#x2266;100 nm; 0.0001 to 0.1 parts by weight of dispersants, and 0.5 to 10 parts by weight of monomers, and the monomers are polymerized with a conversion of &#x2267;80% [polymerization step A], and; b) afterwards, a monomer emulsion containing partial quantity 2, which consists of deionized water, 0.1 to 5 parts by weight of dispersants and 90 to 99.5 parts by weight of monomers, is fed under polymerization conditions to the obtained reaction mixture [polymerization step B], whereby; c) the total amount of the monomers used for the polymerization is equal to 100 parts by weight, and the total amount of deionized water is &#x2266;100 parts by weight.

Method for producing an aqueous polymer dispersion

An emulsifier mixture comprising an emulsifier I of the formula

Emulsifier mixture for emulsion polymerization

The invention provides a process for preparing an aqueous polymer dispersion of a copolymer CP of at least two different monomers M1 and M2 by free-radical aqueous emulsion polymerization of the monomers M in the presence of at least one initiator, at least 80% of the monomers M and at least 75% of the initiator being supplied continuously to the polymerization reaction during its course, which comprises changing the rate at which the initiator is supplied to the polymerization reaction a number of times, or continuously, during the polymerization reaction. The invention further provides the polymer dispersions obtainable by this process, polymer powders prepared therefrom, and for the use of the dispersions and/or of the polymer powders to prepare pressure sensitive adhesives.

Method for producing aqueous polymer dispersions

Contact bonding adhesives

Pressure sensitive adhesives based on polymers of multistage construction

Pressure sensitive materials based on a multistep constituted of polymerizates

Pressure-sensitive adhesives

Readily filterable and deodorizable aqueous dispersions of pressure-sensitive adhesive, especially for self-adhesive labels, having solids contents of more than 65%, can be prepared with readily reproducible properties by copolymerizing esters of acrylic and/or methacrylic acid in the presence of less than 50 ppm of inhibitor and, preferably, in the presence of from 0.01 to 5% by weight of reducing agent by a special emulsion technique. The highly concentrated pressure-sensitive adhesive dispersion, subsequently deodorized with steam, is free from coagulum and seediness.

Production of highly concentrated adhesive dispersions and their use

Pressure-sensitive materials with small amounts of styrene

Copolymers which are self-curable with atmospheric humidity and are based on acrylic, methacrylic and/or vinyl esters which have been prepared using silicon-containing regulators, and mixtures of such polymers with crosslinkers, are suitable as adhesive, sealing and coating compositions which are self-curable with atmospheric humidity.

Copolymers and mixtures which are self-curable with atmospheric humidity

Aqueous polyurethane dispersions contain, at a pH of the dispersing medium of .gtoreq.6, an anionically stabilized polyurethane present in disperse form as well as an added polymer having acidic functions and intended for reducing the flow resistance.

Aqueous polyurethane dispersions

Aqueous dispersions containing a polyurethane and from 5 to 60% by weight, based on the polyurethane, of an adhesion-improving polymer, the polyurethane consisting essentially of

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Bad Duerkheim, Germany

Gerhard Auchter