Release agent and use thereof in the production of moulded polyurethane articles

Abstract

The invention relates to compositions comprising OH-functional polybutadiene and solvent and to the use thereof as release agents in the production of polyurethane moulded articles or as antisquawk agents in the processing of moulded polyurethane articles.

Claims

1. An external mold release agent that comprises A) from 0.5 to 40 wt % of OH-functional polybutadiene, wherein the OH-functional polybutadiene comprises compounds of formula (I), ##STR00002## wherein the units having the index x are present in an average molar fraction based on the sum of the fractions having the indices x, y and z of 17% to 27%, the units having the index y are present in an average molar fraction based on the sum of the fractions having the indices x, y and z of 53% to 63% and the units having the index z are present in an average molar fraction based on the sum of the fractions having the indices x, y and z of 15% to 25% and has an OH number of 20 to 75, B) from 0.0 to 30 wt % of at least one release-active agent distinct from A and wherein the at least one release-active agent is selected from the group consisting of soaps, oils, waxes or silicones, C) from 0.1 to 10 wt % of emulsifiers, D) from 0.1 to 5 wt % of catalysts, E) from 0.1 to 5 wt % of foam stabilizers, F) from 0.0 to 5 wt % of viscosity modifiers, G) from 0.0 to 2 wt % of additives, wherein the additives are selected from the group consisting of cell openers, preservatives, bactericides, fungicides or antioxidants, and H) solvent ad 100 wt %.

2. The external mold release agent according to claim 1, wherein as OH-functional polybutadiene the mold release agent comprises OH-functional polybutadiene having an OH number of 30 to 65.

3. The external mold release agent according to claim 1, wherein the OH-functional polybutadiene has an OH number of 40 to 60.

4. The external mold release agent according to claim 1, wherein the external mold release agent further comprises F) from 0.1 to 5 wt % of viscosity modifiers and the mold release agent has dry mold residue.

5. The external mold release agent according to claim 1, wherein the external mold release agent further comprises G) from 0.1 to 2 wt % of additives selected from the group comprising cell openers, preservatives, bactericides, fungicides or antioxidants.

6. The external mold release agent according to claim 3, wherein the external mold release agent further comprises F) 0.1 to 5 wt % of viscosity modifiers, G) 0.1 to 2 wt % of additives, selected from the group consisting of cell openers, preservatives, bactericides, fungicides or antioxidants.

7. The external mold release agent according to claim 1, wherein the solvent is water.

8. The external mold release agent according to claim 1, wherein the solvent is selected from hydrocarbons having a boiling point of 25 C. to 280 C., and flash points greater than 22 C.

9. The external mold release agent according to claim 1, wherein the OH-functional polybutadiene has a weight-average molar mass of from 3000 to 3500 g/mol.

10. The external mold release agent according to claim 1, wherein the catalyst D) is a bismuth-comprising catalyst.

11. A molded polyurethane article comprising the external mold release agent according to claim 1.

12. The external mold release agent according to claim 1, wherein the solvent is selected from hydrocarbons having a boiling point of from 80 C. to 200 C. and a flash points of greater than 55 C.

13. The external mold release agent according to claim 5, wherein the OH-functional polybutadiene has an OH number of 30 to 65.

14. The external mold release agent according to claim 6, wherein the OH-functional polybutadiene has an OH number of 30 to 65.

15. The external mold release agent according to claim 5, wherein the OH-functional polybutadiene has an OH number of 40 to 60.

16. The external mold release agent according to claim 1, wherein the OH-functional polybutadiene has an OH number of 40 to 60.

17. The external mold release agent according to claim 5, wherein the OH-functional polybutadiene has an OH number of 44 to 55.

18. The external mold release agent according to claim 1, wherein the OH-functional polybutadiene has an OH number of 44 to 55.

19. The external mold release agent according to claim 5, wherein the OH-functional polybutadiene of formula (I) has a weight-average molar mass of from 3000 to 3500 g/mol.

Description

EXAMPLES

(1) Substances Employed:

(2) Polyvest 130=polybutadiene from Evonik Industries AG Polyvest EP HT=OH-functional polybutadiene from Evonik Industries AG Lithene Ultra N4-9000=polymer from Synthomer plc Genamin SH 100D=1-stearylamine from TER HELL & CO. GMBH WACKER L 051 SILICONE OIL=polysiloxane from Wacker Chemie AG Niax SC 240=polysiloxane from Momentive 60% acetic acid from BCD Chemie demineralized water from Reher+Ramsden BNT cat 422=dibutyltin dilaurate from BNT Chemicals Genamin 16R 302D=N,N-dimethylhexadecylamine from TER HELL & CO. GMBH Acticide MBS=mixture of 2-methyl-2H-isothiazol-3-one and 1,2-benzisothiazol-3(2H)-one from Thor Specialties, Inc.
Release Agent 1 (Comparative Example)

(3) 345 g of Polyvest 130, 85 g of Lithene Ultra N4-9000 and 40 g of Genamin SH 100D were initially charged into a glass beaker and heated with stirring to 80 C.; 6 g of acetic acid were then added and the mixture was stirred for a further 5 minutes. 501.7 g of water were then added slowly. Finally, 4.5 g of Wacker silicone L051, 2.8 g of BNT cat 422, 10 g of Genamin 16R 302D and 5 g of Niax SC 240 were added with stirring.

(4) Release Agent 2 (Inventive)

(5) 430 g of Polyvest EP HT and 40 g of Genamin SH 100D were initially charged into a glass beaker and heated with stirring to 80 C.; 6 g of acetic acid were then added and the mixture was stirred for a further 5 minutes. 501.7 g of water were then added slowly. Finally, 4.5 g of Wacker silicone L051, 2.8 g of BNT cat 422, 10 g of Genamin 16R 302D and 5 g of Niax SC 240 were added with stirring.

(6) Release Agent 3 (Inventive)

(7) 215 g of Polyvest EP HT, 172.5 g of Polyvest 130, 42.5 g of Lithene Ultra N4-9000 and 40 g of Genamin SH 100D were initially charged into a glass beaker and heated with stirring to 80 C.; 6 g of acetic acid were then added and the mixture was stirred for a further 5 minutes. 501.7 g of water were then added slowly. Finally, 4.5 g of Wacker silicone L051, 2.8 g of BNT cat 422, 10 g of Genamin 16R 302D and 5 g of Niax SC 240 were added with stirring.

(8) Release Agent Tests:

(9) The release agents diluted in a volume ratio of 1:4 (release agent:water) were sprayed into a box mould by means of a Pilot Mini spray gun from Walther Pilot having a 0.5 mm nozzle in realistic usage amounts of 20 g/m.sup.2 and an expandable polyurethane system composed of 100 parts of Desmophen PU 21IK01, 3.5 parts of water, 0.4 parts of Tegoamin TA 33, 0.25 parts of Tegoamin AS-1, 0.7 parts of diethanolamine, 0.5 parts of Tegostab EP-K-38, 0.2 parts of acetic acid (60% in water), 63.5 parts of Suprasec 2412 was expanded in this box mould at 55 C.

(10) After curing (10 minutes) the foam pieces were removed from the box mould and the residues on the foam pieces (cushion residue) and in the box mould (mould residue) were subjected to haptic evaluation. The results of these release agent tests are reported in Table 1.

(11) TABLE-US-00001 TABLE 1 Release agent test results: Release agent Cushion residue Mould residue 1 severely oily and solid transparent film difficult to clean severely sticky 2 dry dry 3 slightly oily slightly oily

(12) As is apparent from Table 1, use of the inventive release agents (2 and 3) results in a markedly reduced oiliness than when release agent 1 is used.