Process for producing aqueous dispersions of thermoplastic polyesters
AssigneeBASF SE
InventorsLiqun Ren, Gimmy Alex Fernandez Ramirez, Motonori Yamamoto, Hermann Seyffer, Gabriel Skupin
Life of this patent
Estimating the term…
Abstract
The present invention relates to a process for producing aqueous dispersions of thermoplastic polymers which have a plurality of ester groups and/or carbonate groups in the main polymer chain and which have an acid number of less than 5 mg KOH/g, in particular at most 3 mg KOH/g, and which have a zero-shear viscosity η0 (180° C.) of at least 60 Pa·s at 180° C. The invention also relates to the polymer dispersions obtainable by said process, and to the use thereof.
Claims42
-41. (canceled)
A process for producing aqueous dispersions of thermoplastic polymers which have a plurality of ester groups and/or carbonate groups in the main polymer chain and which have an acid number of less than 5 mg KOH/g, and which have a zero-shear viscosity η0 of at least 60 Pa·s at 180° C.,
- which comprises introducing a composition which comprises the polymer and which is composed of at least 99% by weight of the polymer at a temperature above the melting or softening point of the polymer, into an aqueous dispersion medium which comprises at least one surfactant substance, and the resultant aqueous emulsion of the polymer is quenched,
- wherein the introduction of the polymer into the aqueous dispersion medium is carried out in a mixing apparatus which has at least one rotor-stator mixer.
The process according to claim 41, wherein the rotor-stator mixer has means of generating cavitation forces.
The process according to claim 41, wherein the rotor-stator mixer is a toothed-ring dispersing machine.
The process according to claim 41, wherein the mixing apparatus has a plurality of rotor-stator mixers connected to one another in series.
The process according to claim 41, wherein the introduction of the melt into the aqueous dispersion medium takes place at a temperature which is at least 20 K above the melting or softening point of the polymer.
The process according to claim 41, wherein the polymer is a polyester, polyetherester, polyesteramide, polycarbonate, or mixtures of these.
The process according to claim 41, wherein the polymer is a polyester which in essence is composed of:
- a) at least one dicarboxylic acid component A, which is composed of
- a1) at least one aliphatic or cycloaliphatic dicarboxylic acid or ester-forming derivatives thereof, or a mixture thereof, and
- a2) optionally one or more aromatic dicarboxylic acids or ester-forming derivatives thereof, or a mixture thereof;
- b) at least one diol component B, selected from aliphatic and cycloaliphatic diols and mixtures thereof;
- c) optionally one or more further bifunctional compounds C which react with carboxylic acid groups or with hydroxy groups to form bonds;
- and
- d) optionally one or more compounds D which have at least 3 functionalities which react with carboxylic acid groups or with hydroxy groups to form bonds;
- wherein the compounds a1), a2), B), C), and D) comprise not more than 3 mol %, based on the total amount of compounds of component A, of compounds which have one or more sulfonic acid groups, and wherein the molar ratio of component A to component B is in the range from 0.4:1 to 1:1, and components A and B make up at least 80% by weight of the polyester.
An aqueous polymer dispersion comprising, in the form of dispersed polymer particles, at least one thermoplastic polymer which has a plurality of ester groups and/or carbonate groups in the main polymer chain and which has an acid number of less than 10 mg KOH/g, and has a zero-shear viscosity η0 of at least 60 Pa·s at 180° C., in which the diameter, determined by light scattering, of at least 90% by weight of the polymer particles of the dispersion is below 10 μm.
A thermoplastic polyester comprising, in the form of condensation products thereof:
- a1) from 60 to 80 mol %, based on the total amount of components a1) and a2), of at least one aliphatic dicarboxylic acid or ester-forming derivative thereof, or a mixture thereof, and
- a2) from 20 to 40 mol %, based on the total amount of components a1) and a2), of terephthalic acid or ester-forming derivatives thereof, or a mixture thereof;
- b) from 98 to 102 mol %, based on the total amount of components a1) and a2), of at least one diol component b), selected from 1,3-propanediol and 1,4-butanediol and mixtures thereof;
- c) from 0 to 2% by weight, based on the total weight of the polyester, of one or more further bifunctional compounds C which react with carboxylic acid groups or with hydroxy groups to form bonds;
- and
- d) from 0.1 to 2% by weight, based on the total weight of the polyester, of one or more compounds D which have at least 3 functionalities which react with carboxylic acid groups or with hydroxy groups to form bonds;
- and components a1), a2), and b) make up from 96 to 99.8% by weight of the polyester.
Dependencies are inferred from the claim text.