Use of a branched polyester

Abstract

The invention relates to the use of a branched polyester having an average of at least 2.8 terminal groups as additive for a curable pre-polymer composition, wherein the branched polyester acts as de-foaming agent.

Claims

1. A method of modifying a curable pre-polymer composition, the method comprising: adding an additive to the curable pre-polymer composition, the additive comprising a branched polyester having an average of at least 2.8 terminal groups, wherein the branched polyester acts as a de-foaming agent; wherein the additive comprises a solution of the branched polyester in a solvent having a boiling point above 250° C. at atmospheric pressure.

2. The method according to claim 1, wherein the branched polyester acts as an internal release agent and as the de-foaming agent.

3. The method according to claim 1, wherein the branched polyester has an average of at least 3.1 terminal groups.

4. The method according to claim 1, wherein at least 50% of the terminal groups of the branched polyester are terminated by hydrocarbyl groups having from 8 to 40 carbon atoms.

5. The method according to claim 1, wherein the terminal groups comprise residues of fatty acids having 10 to 30 carbon atoms.

6. The method according to claim 1, wherein the terminal groups comprise residues of fatty alcohols having 10 to 30 carbon atoms.

7. The method according to claim 1, wherein the branched polyester has a number average molecular weight in the range of 1500 to 15000.

8. The method according to claim 1, wherein the branched polyester is added to the curable pre-polymer composition in an amount of 0.1 to 15.0% by weight, calculated on the weight of the curable pre-polymer composition.

9. The method according to claim 1, wherein the solvent is an ester of a fatty acid and an alcohol having at least 6 carbon atoms.

10. The method according to claim 1, wherein the curable pre-polymer composition comprises curable functional groups comprising one or more of ethylenically unsaturated groups, epoxide groups, isocyanate groups, hydroxyl groups, amine groups, and carboxylic acid groups.

11. The method according to claim 1, wherein the curable pre-polymer composition comprises one or more additional components selected from fillers, pigments, stabilizers, dispersants, and fibers.

12. A curable pre-polymer composition comprising i) a curable pre-polymer, ii) a branched polyester having an average of at least 2.8 terminal groups, wherein the terminal groups comprise residues of fatty acids and/or fatty alcohols having 10 to 30 carbon atoms, and wherein the branched polyester is present in an amount of 2.5 to 15.0% by weight, calculated on the weight of the curable pre-polymer composition, and iii) a solvent having a boiling point above 250° C. at atmospheric pressure.

13. The method according to claim 1, wherein at least 70% of the terminal groups of the branched polyester are terminated by hydrocarbyl groups having from 8 to 40 carbon atoms.

14. A method of modifying a curable pre-polymer composition, the method comprising: adding an additive to the curable pre-polymer composition, the additive comprising a branched polyester having an average of at least 2.8 terminal groups, wherein the branched polyester acts as a de-foaming agent; wherein the additive comprises a solution of the branched polyester in a solvent having a boiling point above 250° C. at atmospheric pressure; wherein the terminal groups comprise residues of fatty alcohols having 10 to 30 carbon atoms.

15. The method according to claim 14, wherein the branched polyester acts as an internal release agent and as the de-foaming agent.

16. The method according to claim 14, wherein the branched polyester has an average of at least 3.1 terminal groups.

17. The method according to claim 14, wherein at least 50% of the terminal groups of the branched polyester are terminated by hydrocarbyl groups having from 8 to 40 carbon atoms.

18. The method according to claim 14, wherein the branched polyester has a number average molecular weight in the range of 1500 to 15000.

19. The method according to claim 14, wherein the branched polyester is added to the curable pre-polymer composition in an amount of 0.1 to 15.0% by weight, calculated on the weight of the curable pre-polymer composition.

20. The method according to claim 14, wherein the additive comprises a solution of the branched polyester in a solvent having a boiling point above 250° C. at atmospheric pressure.

21. The method according to claim 20, wherein the solvent is an ester of a fatty acid and an alcohol having at least 6 carbon atoms.

22. The method according to claim 14, wherein the curable pre-polymer composition comprises curable functional groups comprising one or more of ethylenically unsaturated groups, epoxide groups, isocyanate groups, hydroxyl groups, amine groups, and carboxylic acid groups.

23. The method according to claim 14, wherein the curable pre-polymer composition comprises one or more additional components selected from fillers, pigments, stabilizers, dispersants, and fibers.

24. The method according to claim 14, wherein at least 70% of the terminal groups of the branched polyester are terminated by hydrocarbyl groups having from 8 to 40 carbon atoms.

Description

EXAMPLES

Preparation of Branched Polyesters

General Procedure for Preparation of Branched Polyesters

(1) The raw materials indicated in Table 1 were mixed at room temperature and subsequently heated to 220° C. Water was distilled off and heating was continued until an acid value below 10 mg KOH/g was reached, determined according to DIN EN ISO 2114. Vacuum was applied to remove residual water and the reaction mixture was cooled to room temperature.

(2) TABLE-US-00001 TABLE 1 Raw material for preparation of branched polyesters Amount of Amount of Amount of monofunctional Monofunctional multifunctional Multifunctional Product Catalyst Catalyst Component Component Components Components A 0.32 g Dodecylbenzene 70.0 g Tall oil fatty acid 16.3 g Pentaerythritol sulfonic acid 17.3 g Sebacic acid B 0.32 g Dodecylbenzene 71.0 g Tall oil fatty acid 22.0 g Trimethylolpropane sulfonic acid 17.3 g Adipic acid C 0.32 g Dodecylbenzene 72.0 g Oleic acid 15.2 g Pentaerythritol sulfonic acid 12.5 g Adipic acid D 0.32 g Dodecylbenzene 72.0 g Oleic acid 15.2 g Pentaerythritol sulfonic acid 10.2 g Adipic acid 7.0 g Sebacic acid E 0.32 g Dodecylbenzene 67.5 g Oleyl alcohol 28.6 g Trimellitic acid sulfonic acid 10.1 g anhydride Hexane diol F 0.32 g Dodecylbenzene 54.0 g Myristyl alcohol 28.6 g Trimellitic acid sulfonic acid 10.1 g anhydride 1,6-Hexane diol

(3) The effectiveness of the branched polyesters A to F summarized above as de-foaming agents was tested in different resin systems. The raw materials used for testing are mentioned in Table 2 below:

(4) TABLE-US-00002 TABLE 2 Raw material Description Epikote Resin MGS Epoxy resin based on Bisphenol RIM R 135 A, Momentive Epikure Curing Agent Amine Hardener, Momentive MGS RIM H 137 Atlac Premium 100 Styrene-free Vinyl ester resin, Aliancys Palatal P4-01 Polyester resin, Aliancys Laromer 8986 Modified Epoxyacrylate, BASF Irgacure 500 UV - initiator, BASF Laromer DPGDA Dipropylene glycol diacrylate, BASF Accelerator NL-49P Cobalt(II) 2-ethylhexanoat 1% Cobalt, Akzo Nobel Butanox LPT-IN Initator based on methyl ethyl ketone peroxide, AkzoNobel Butanox M 50 Initator based on methyl ethyl ketone peroxide, AkzoNobel Saertex X-E 830 g/m.sup.2 - 1260 mm biaxial glass matt, Saertex Calcium Stearate CAS-Nr.: 1592-23-0 Zink stearate CAS-Nr.: 557-05-1 Isotridecyl stearate CAS-Nr.: 31565-37-4

Test System 1

(5) To 100 g of Epikote Resin MGS RIM R 135 was added the test substance (amount and description: see Table 3). The mixture was stirred by hand until the mixture was homogeneous. Afterwards, 30 g of Epikure Curing Agent MGS RIM H 135 was added. This mixture was stirred using a dissolver (Pendraulik TD 100, Dissolver plate diameter: 40±10 mm) for 60 seconds±10 seconds with a speed of 2800 rpm±250 rpm to create foam. 50 g±1 g of the final mixture was transferred to a cylindric glass tube and the filling level including foam was determined. Based on the filling height with foam, the samples were rated with marks from 1 (very good defoaming properties, low foam height) to 5 (poor defoaming properties, high foam height).

(6) TABLE-US-00003 TABLE 3 Rating Exp.- Amount Test defoaming No. Test Substance Substance properties  1 A 0.1 g 2  2 A 0.3 g 1-2  3 A 0.5 g 1-2  4 B 0.3 g 1  5 C 0.1 g 2  6 C 0.3 g 1-2  7 D 0.3 g 2  8 E 0.1 g 2-3  9 E 0.3 g 1 10 F 0.3 g 3 11* None 5 12* Calcium stearate 0.3 g 5 13* Calcium stearate 0.5 g 5 14* Calcium stearate 1.0 g 5 15* Zink stearate 0.5 g 5 16* Zink stearate 1.0 g 5 17* Isotridecyl stearate 0.5 g 5 18* Isotridecyl stearate 1.0 g 5

(7) It can be inferred from Table 3 that the branched polyesters used according to the invention in Examples 1 to 10 exhibit very useful de-foaming properties. Comparative examples 11 to 18 demonstrate that the test system is severely hampered by foam formation when no additive or other additives than those according to the invention are included.

Test Systems 2 to 4

(8) To Part A of a system (listed in Table 4 as Part A) was added the test substance (amount and description: see Table 4). The mixture was stirred by hand until the mixture was homogeneous. Afterwards, Part B of a system (listed in Table 4 as Part B) and Part C of a system (listed in Table 4 as Part C) was added. This mixture was stirred using a dissolver (Pendraulik TD 100, Dissolver plate diameter: 40±10 mm) for 60 seconds±10 seconds with a speed of 2800 rpm±250 rpm to homogenize and to create foam.

(9) Directly after stirring the material was poured out on a polyester sheet. After 30 seconds the surface of the material was covered by a second polyester sheet and the mixture was cured between the sheets.

(10) After curing, the two sheets were removed and panels of 10×10 cm were cut out of the material. The panels were rated by comparing the total amount of air bubbles entrapped in the panel with marks from 1 (very good defoaming properties, nearly no bubbles entrapped) to 5 (poor defoaming properties, many air bubbles entrapped).

Test System 2

(11) TABLE-US-00004 Part A Atlac Premium 100 Part B Accelerator NL-49P Part C Butanox LPT-IN

Test System 3

(12) TABLE-US-00005 Part A Palatal P4-01 Part B Accelerator NL-49P Part C Butanox M 50

Test System 4

(13) TABLE-US-00006 Part A Laromer 8986 Part B Dipropylene glycol diacrylate Part C Irgacure 500

(14) TABLE-US-00007 TABLE 4 Amount Rating Exp.- Test Amount Test Test Amount Amount defoaming No. system Part A Substance Substance Part B Part C properties 19 2 100 g 0.3 g A 2 g 2 g 3-4 20 2 100 g 0.3 g C 2 g 2 g 3-4 21 2 100 g 0.3 g D 2 g 2 g 4 22 2 100 g 0.3 g F 2 g 2 g 3-4 23* 2 100 g — 2 g 2 g 5 24* 2 100 g 0.3 g Calcium 2 g 2 g 5 stearate 25* 2 100 g 0.3 g Isotridecyl 2 g 2 g 5 stearate 26 3 100 g 0.3 g B 1 g 2 g 4 27 3 100 g 0.3 g C 1 g 2 g 3 28 3 100 g 0.3 g D 1 g 2 g 2-3 29 3 100 g 0.3 g E 1 g 2 g 3-4 30 3 100 g 0.3 g F 1 g 2 g 3 31* 3 100 g 0.3 g — 1 g 2 g 5 32* 3 100 g 0.3 g Calcium 1 g 2 g 5 stearate 33* 3 100 g 0.3 g Isotridecyl 1 g 2 g 5 stearate 34 4 65 g 0.3 g C 30 g 5 g 2 35* 4 65 g — — 30 g 5 g 5 36* 4 65 g 0.3 g Isotridecyl 30 g 5 g 5 stearate

(15) It can be inferred from Table 4 that the branched polyesters used according to the invention in Examples 19 to 22, 26 to 30, and 34 exhibit very useful de-foaming properties. Comparative examples 23 to 25, 31 to 33, 35, and 36 demonstrate that the test system is severely hampered by foam formation when no additive or other additives than those according to the invention are included.

Test of Mold Release Properties

(16) Two layers of glass fabrics (Saertex X-E-830 g/m.sup.2, roving PPG 2002 (dimension: 350×350 mm)) were placed in an infusion mold (40×40 cm inner diameter, Aluminum, surface hard anodized, encircling seals in the top and bottom half of the mold, vacuum applied from the top outlet via hose; four resin inlets on the bottom half of the mold, resin inlet via hose) and vacuum was applied until a pressure of at least 10 mbar was achieved.

(17) A homogeneous mixture of 100 parts Epikote Resin MGS RIMR 135, the test substance (amount and description: see Table 5) and 30 parts of Epikure Curing Agent MGS RIM H 137 that was freshly mixed using a Dispermat TYPE CN 40 F2 (Dissolver plate diameter: 40±10 mm) for 300 seconds±10 seconds with a speed of 930 rpm±50 rpm using a vacuum of 50 mbar±5 mbar.) was infused over the four hoses on the bottom side until the liquid resin mixture appeared in the hose on the top side.

(18) After infusion, the hoses were sealed on the in- and outlet with a plug and the entire mold with hoses was placed in a convection oven to cure the panel for 10 h at 80° C.

(19) Afterwards, the mold was opened and the cured panel was removed. The force to demold the panel was compared within the different trials.

(20) The force needed to demold the panel was rated with marks from 1 (very easy demolding, no force needed) to 5 (poor demolding, fracture in the panel during demolding).

(21) TABLE-US-00008 TABLE 5 Amount Test Rating mold Exp.-No. Test Substance Substance release 37 A 1 g 2-3 38 A 2 g 1 39 A 3 g 1 40 C 1 g 2-3 41 C 2 g 2 42 C 3 g 1 43 D 1 g 2 44 D 2 g 1 45 E 1 g 2 46 E 2 g 1-2 47 F 1 g 2 48 F 2 g 1-2 49* Calcium stearate 2 g 3-4 50* Calcium stearate 3 g 2 51* Zink stearate 3 g 2 52* Isotridecyl stearate 3 g 2-3 52* — — 5

(22) From Table 5 it can be inferred that the branched polyesters used according to the invention in Examples 37 to 48 are very effective as internal mold release agents. They are effective when used in small amounts and provide equal or better mold release properties than known internal release agents used according to comparative Examples 49 to 52. Thus, the branched polyesters have a twofold beneficial effect, because they act as mold release agent and as de-foaming agent when used according to the invention.