Thermoplastic

Abstract

The present invention relates to a thermoplastic, unsaturated semi-crystalline polyester (A) with a Mp of 35 DEG C or above comprising allyl functional groups of formula 1, wherein X is selected fromO, N, S and / or P, the value of n is 1 to 4, preferably 1 or 2, the value of p is 0 or 1, R is a substituted or unsubstituted aromatic, aliphatic or cycloaliphatic carbon chain with a number of carbonatoms from 0 to 10, preferably from 2 to 6, and m is at least 1, preferably between 1 and 3, the polyester (A) having a melt viscosity at 130 DEG C below 5 Pas, preferably below 3, more preferably below 1,5 Pas, the polyester (A) containing compounds supporting crystallinity selected from the group comprising saturated and unsaturated, unbranched aliphatic, cycloaliphatic and aromatic alcohols, polyols, carboxylic acids, di- and polycarboxylic acids, anhydrides and derivatives thereof and compounds exhibiting more than one of the listed functional groups, wherein the functional groups of cycloaliphatic and aromatic compounds are located opposite to each other, for example in case of six-membered rings in para / 1,4- position, and in all cases the compounds supporting crystallinity contain nofurther substitution besides the above mentioned alcohol, anhydride or carboxylic groups or derivatives thereof, and wherein the mass fraction of compounds supporting crystallinity based on the massof the polyester obtained from the synthesis is more than 70%, preferably more than 80%, more preferable more than 90% and most preferably more than 100%. The invention also relates to a process for the production of such a polyester (A) as well as to powder coating composition comprising at least one of such polyester (A).

Description

technical field [0001] The present invention relates to a thermoplastic unsaturated semi-crystalline polyester (A) containing an allyl functional group with a melting point of 35° C. or higher, a method for producing the polyester (A), and the polyester (A) in powder Use in binder systems of coating compositions and powder coatings comprising at least one thermoplastic polyester (A) and at least one thermoplastic amorphous polymer (B) comprising ethylenically unsaturated groups A composition wherein the polyester (A) and the polymer (B) are capable of being copolymerized with each other. Background technique [0002] Powder coating is a very environmentally friendly coating material compared to solvent-based coatings. In particular, almost complete material availability, absence of VOC components, and its simple application have led to an increase in the market share of powder coatings. However, coating heat-sensitive substrates with powder coatings presents technical chal...

AI Technical Summary

Problems solved by technology

[0016] It is an object of the present invention to overcome the disadvantages of said prior art with respect to powder coating formulations regarding too high baking temperatures for heat sensitive substrates, problems associated with insufficient UV curing or dual curing, and Insufficient storage stability, resistance to cold fluids, or flexibility

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