Thermosetting powder coating compositions comprising peroxydicarbonates

Patent metadata

Field	Value
Publication number	US-10913859-B2
Application number	US-201716336168-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Sep 28, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

The invention relates to thermosetting powder coating compositions as disclosed herein, said compositions comprising one or more unsaturated resins comprising ethylenic unsaturations, one or more curing agents, and one or more thermal radical initiators, wherein at least one of the initiators is a peroxydicarbonate-X. The invention further relates to a process for making said thermosetting powder coating compositions and processes for coating an article with said thermosetting powder coating compositions. The invention further relates to cured thermosetting powder coating compositions obtained by curing of the thermosetting powder coating compositions of the invention. The invention further relates to an article having coated thereon said thermosetting powder coating composition as well as to an article having coated and cured thereon said thermosetting powder coating composition. The invention further relates to the use of said thermosetting powder coating compositions, to the use of an article having coated thereon said thermosetting powder coating compositions and to the use of an article having coated and cured thereon said thermosetting powder coating compositions. The invention further relates to various uses of either the thermosetting powder coating compositions of the invention, or the cured thermosetting powder coating compositions of the invention or of articles having coated thereon the thermosetting powder coating composition of the invention, or of articles having coated and cured thereon the thermosetting powder coating composition of the invention. The invention further relates to a method for enabling the fast heat-curing of a thermosetting powder coating composition at low temperature. The invention further relates to a method for enhancing the chemical resistance of a powder coating obtained by heat curing of the thermosetting powder coating composition of the invention at low temperature.

First claim

The invention claimed is:

1. A thermosetting powder coating composition comprising the following components A to C:
A: one or more unsaturated resins comprising ethylenic unsaturations (UR) selected from the group consisting of polyester resins, acrylic resins, polyurethanes, epoxy resins, polyamides, polyesteramides, polycarbonates, polyureas and mixtures thereof,
B: one or more curing agents selected from the group consisting of vinyl urethanes, vinyl functionalized urethane resins and mixtures thereof, wherein at least one curing agent is a curing agent A which is selected from the group consisting of i), ii) and iii):
i) one or more crystalline VU-c each of which is a crystalline vinyl urethane having a melting enthalpy ΔH m ≥35 J/g, and one or more melting temperatures (T m ) wherein any and all of the T m of the one or more crystalline VU-c are in the region of from and including 30 up to and including 80° C.,
ii) one or more crystalline VFUR-c each of which is a crystalline vinyl functionalized urethane resin having a melting enthalpy ΔH m ≥35 J/g, and one or more melting temperatures (T m ) wherein any and all of the T m of the one or more crystalline VFUR-c are in the region of from and including 30 up to and including 80° C., and
iii) mixtures of crystalline VU-c and crystalline VFUR-c, wherein the ΔH m and T m is each measured via Differential Scanning calorimetry (DSC), and

C: one or more thermal radical initiators, wherein at least one thermal radical initiator is peroxydicarbonate-X which is present in an amount of at least 26 and at most 500 mmol/Kg A and B, and wherein the peroxydicarbonate-X is selected from the group consisting of peroxydicarbonates represented by the following formula X, and mixtures thereof,

wherein R 1 is C 9 -C 22 saturated hydrocarbyl, and R 2 is C 9 -C 22 saturated hydrocarbyl.

2. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at most 400 mmol/Kg A and B.

3. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at most 350 mmol/Kg A and B.

4. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at most 300 mmol/Kg A and B.

5. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at least 30 mmol/Kg A and B.

6. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at least 40 mmol/Kg A and B.

7. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is present in an amount of at least 45 mmol/Kg A and B.

8. The thermosetting powder coating composition according to claim 1 , wherein the total amount of the component C is at most 500 mmol/Kg A and B.

9. The thermosetting powder coating composition according to claim 2 , wherein the total amount of the component C is at most 400 mmol/Kg A and B.

10. The thermosetting powder coating composition according to claim 3 , wherein the total amount of the component C is at most 350 mmol/Kg A and B.

11. The thermosetting powder coating composition according to claim 4 , wherein the total amount of the component C is at most 300 mmol/Kg A and B.

12. The thermosetting powder coating composition according to claim 1 , wherein the peroxydicarbonate-X is selected from the group consisting of dimyristyl peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, dicetyl peroxydicarbonate, and mixtures thereof.

13. The thermosetting powder coating composition according to claim 1 , wherein B is present in an amount of at least 15 and at most 55 pph of A and B.

14. The thermosetting powder coating composition according to claim 1 , wherein the curing agent A is present in an amount of at least 70 pph of B.

15. The thermosetting powder coating composition according to claim 1 , wherein the curing agent A is present in an amount of at least 80 pph of B.

16. The thermosetting powder coating composition according to claim 1 , wherein the thermosetting powder coating composition has a ratio K which is at least 0.6 and at most 3, wherein the ratio K is a ratio of the total mol of the ethylenic unsaturations in B (Total Mol B ) divided by the total mol of the ethylenic unsaturations in A (Total Mol A ).

17. The thermosetting powder coating composition according to claim 16 , wherein the ratio K is at least 0.95 and at most 2.5.

18. The thermosetting powder coating composition according to claim 1 , wherein the curing agent A has a crystallization temperature (T c ) of at least 10 and at most 70° C., wherein the T c is measured via Differential Scanning Calorimetry (DSC).

19. The thermosetting powder coating composition according to claim 1 , wherein the thermosetting powder coating composition further comprises a component D, as follows:
D: one or more co-initiators selected from the group consisting of onium compounds, sulpho compounds, and mixtures thereof, and wherein the component D is present in an amount of at most 95 mmol/Kg A and B.

20. The thermosetting powder coating composition according to claim 1 , wherein the thermosetting powder coating composition further comprises a component D, as follows:
D: one or more co-initiators selected from the group consisting of onium compounds, sulpho-compounds, and mixtures thereof, and wherein the onium compounds are selected from the group consisting of compounds represented by the following formulas l-X and II-X:

wherein
A − is selected from the group consisting of halide anions; and
R 1 ′″ is a C 1 -C 12 saturated hydrocarbyl, and R 2 ′″ is a C 1 -C 12 saturated hydrocarbyl; and wherein
the component D is present in an amount of at most 95 mmol/Kg A and B.

21. The thermosetting powder coating composition according to claim 1 , wherein the thermosetting powder coating composition further comprises a component E, as follows:
E: one or more inhibitors selected from the group consisting of phenolic compounds, stable radicals, catechols, phenothiazines, hydroquinones, benzoquinones and mixtures thereof, wherein
the total amount of component E is at least 20 and at most 1500 mg/Kg A and B.

22. The thermosetting powder coating composition according to claim 1 , wherein the UR is an unsaturated polyester resin comprising 2-butenedioic acid ethylenic unsaturations.

23. The thermosetting powder coating composition according to claim 1 , wherein the UR has:
a) a number average molecular weight (Mn) of at least 1000 and at most 10000 Da measured via Gel Permeation Chromatography (GPC),
b) a glass transition temperature (T g ) of at least 40 and at most 75° C. measured via Differential Scanning Calorimetry (DSC), and
c) a weight per unsaturation (WPU) of at least 250 and at most 2200 g/mol measured via 1 H-NMR spectroscopy.

24. The thermosetting powder coating composition according to claim 1 , wherein the curing agent A is selected from the group consisting of i), ii) and iii):
i) one or more crystalline VU-c each of which is a crystalline viny

Assignees

• Dsm Ip Assets Bv

Inventors

• Bongaerts Johannes Gertrudis Christianus
• Popescu Dragos

Classifications

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• C08G18/671 Primary

  Unsaturated compounds having only one group containing active hydrogen (takes precedence on groups C08G18/675 - C08G18/69) · CPC title

• C09D175/14

  Polyurethanes having carbon-to-carbon unsaturated bonds · CPC title

• C08K5/42

  Sulfonic acids; Derivatives thereof · CPC title

• C08K5/23

  Azo-compounds · CPC title