PRODUCTION OF POLYURETHANE FOAM

Abstract

Composition for producing polyurethane foam, in particular rigid polyurethane foam, comprising at least an isocyanate component, a polyol component, optionally a catalyst that catalyses the formation of a urethane or isocyanate linkage, blowing agents, wherein the composition comprises polyester-polysiloxane block copolymers.

Claims

1-15. (canceled)

16. A composition for producing polyurethane (PU) foam, comprising at least an isocyanate component, a polyol component, blowing agents, and, optionally, a catalyst that catalyses the formation of a urethane or isocyanate linkage, wherein the composition comprises polyester-polysiloxane block copolymers.

17. The composition of claim 16, wherein polyester-polysiloxane block copolymers of formula 1 are used: ##STR00004## wherein: R.sup.1=identical or different aliphatic or aromatic hydrocarbon radicals having 1 to 16 carbon atoms; R.sup.2=identical or different radicals from the group R.sup.1, R.sup.3 or R.sup.4; R.sup.3=identical or different polyester radicals; R.sup.4=identical or different polyether radicals; a=5-200; b=1-20; c=0-20; with the proviso that at least one radical R.sup.3 must be present in the molecule.

18. The composition of claim 17, wherein: R.sup.1=aliphatic or aromatic hydrocarbon radicals having 1 to 8 carbon atoms; R.sup.2=R.sup.1; R.sup.3=identical or different polyester radicals of the general formula 2: ##STR00005## wherein: R.sup.5=identical or different divalent alkyl radicals optionally interrupted by one or more oxygen atoms; R.sup.6=O or NH or NMe; R.sup.7=identical or different divalent alkyl radicals having 1 to 20 carbon atoms; R.sup.8=identical or different radicals of general formula C(O)R.sup.10 or H; R.sup.10=identical or different alkyl radicals having 1 to 16 carbon atoms; R.sup.4=identical or different polyether radicals of the formula 3: ##STR00006## wherein: R.sup.11=identical or different divalent alkyl radicals having 2 to 12 carbon atoms; R.sup.12=identical or different alkyl radicals having 1 to 12 carbon atoms; R.sup.13=identical or different radicals from the group: C(O)R.sup.10, H and alkyl radicals having 1-8 carbon atoms; a=5-100; b=1-15; c=0-15; d=2 to 80; e=1-16; x=0 to 80; y=0 to 80; z=0 to 60; with the proviso that x+y+z>2; and with the proviso that at least two different radicals R.sup.7 are present in the molecule.

19. The composition of claim 18, wherein: R.sup.1=methyl or phenyl; R.sup.2=R.sup.1; R.sup.5=(CH.sub.2).sub.3, (CH.sub.2).sub.6, (CH.sub.2).sub.3OCH.sub.2CH.sub.2 or (CH.sub.2).sub.3OCH.sub.2CH(CH.sub.3); R.sup.6=O; R.sup.7=alkyl radicals of the general formula [CR.sup.9.sub.2].sub.e; R.sup.9=identical or different alkyl radicals having 1 to 8 carbon atoms or H; R.sup.8=H; R.sup.10=methyl; R.sup.11=divalent alkyl radicals having 3 to 6 carbon atoms; R.sup.12=methyl, ethyl or phenyl; R.sup.13=C(O)CH.sub.3, H or methyl; a=10-80; b=2-10; c=0; d=3 to 40; e=1 to 6; x=3 to 40; y=3 to 40; z=0.

20. The composition of claim 18, wherein the polyester-polysiloxane block copolymers are obtained through reaction of cyclic esters, of the cyclic dimers thereof or of higher analogues with alcohol- and/or amino-functional siloxanes.

21. The composition of claim 20, wherein at least two or more different cyclic esters are used in the production of the polyester-polysiloxane block copolymers.

22. The composition of claim 20, wherein the cyclic esters are selected from the group consisting of: propiolactone; lactide; caprolactone; butyrolactone; and valerolactone.

23. The composition of claim 16, wherein the PU foam is a rigid foam and the polyester-polysiloxane block copolymers are used in a total amount of 0.01 to 15 parts, based on 100 parts of polyols.

24. The composition of claim 23, wherein the polyester-polysiloxane block copolymers are used in a total amount of 0.1 to 10 parts, based on 100 parts of polyols.

25. The composition of claim 23, wherein the polyester-polysiloxane block copolymers are used in a total amount of 0.1 to 5 parts, based on 100 parts of polyols.

26. The composition of claim 16, wherein the composition uses as blowing agents hydrocarbons having 3, 4 or 5 carbon atoms.

27. The composition of claim 16, wherein the composition uses as blowing agents HFC 245fa, HFC 134a and/or HFC 365mfc, perfluorinated compounds, hydrohaloolefins, water, oxygen-containing compounds and/or chlorinated hydrocarbons.

28. The composition of claim 18, wherein the composition uses as blowing agents HFC 245fa, HFC 134a and/or HFC 365mfc, perfluorinated compounds, hydrohaloolefins, water, oxygen-containing compounds and/or chlorinated hydrocarbons.

29. The composition of claim 16, wherein the polyester-polysiloxane block copolymers contain, in addition to the polyester side chains, polyether side chains.

30. The composition of claim 18, wherein the polyester-polysiloxane block copolymers contain, in addition to the polyester side chains, polyether side chains.

31. The composition of claim 16, wherein siloxane-based foam stabilizers comprising exclusively polyethers are present to an extent, based on the total amount of foam stabilizers, of less than 10% by weight.

32. The composition of claim 16, wherein Si-containing foam stabilizers are present to an extent, based on the total amount of foam stabilizers, of more than 20% by weight.

33. The composition of claim 32, wherein Si-containing foam stabilizers are present to an extent, based on the total amount of foam stabilizers, of more than 50% by weight.

34. A process for producing PU foams based on foamable reaction mixtures comprising polyisocyanates, compounds having reactive hydrogen atoms, blowing agents and optionally other additives, wherein the polyester-polysiloxane block copolymers of claim 1 are used.

35. A rigid PU foam, produced by the process of claim 34.

Description

EXAMPLES

Example 1: Synthesis of Polyester-Polysiloxane Block Copolymers

[0086] All reactions were carried out under an inert gas atmosphere.

[0087] Block Copolymer A:

[0088] A 5 L three-necked flask with precision glass stirrer, thermometer and dropping funnel was charged with 813.9 g of 2-allyloxyethanol (CAS: 111-45-5) and this was heated to 100 C. 1.5 g of a toluene solution of Karstedt's catalyst (w (Pt)=2%) was then added. This was followed by the metered addition, over a period of two hours, of 2186.1 g of a siloxane of the general formula Me.sub.3SiO(SiMe.sub.2O).sub.11(SiMeHO).sub.3SiMe.sub.3. An exothermic reaction commenced. The reaction temperature was maintained between 100 and 110 C. At the end of the metered addition, the mixture was stirred for a further 2 h. Complete conversion of the SiH functions was established gas-volumetrically. The reaction mixture was then heated to 130 C. and stripped of volatiles for 1 h at 1 mbar. A clear, slightly yellowish liquid (step 1) was obtained.

[0089] A 5 L three-necked flask with precision glass stirrer and thermometer was charged with 1175 g of step 1 together with 825 g of -caprolactone (CAS: 502-44-3), 500 g of dilactide (CAS: 95-96-5) and 2.5 g of Kosmos 29 (tin catalyst from Evonik). The mixture was stirred at 140 C. for 5 h. A liquid polyester-polysiloxane block copolymer was obtained.

[0090] Block Copolymer B:

[0091] A 5 L three-necked flask with precision glass stirrer, thermometer and dropping funnel was charged with 500.4 g of 2-allyloxyethanol (CAS: 111-45-5) and this was heated to 100 C. 1.5 g of a toluene solution of Karstedt's catalyst (w (Pt)=2%) was then added. This was followed by the metered addition, over a period of two hours, of 2449.6 g of a siloxane of the general formula Me.sub.3SiO(SiMe.sub.2O).sub.51(SiMeHO).sub.7SiMe.sub.3. An exothermic reaction commenced. The reaction temperature was maintained between 100 and 110 C. At the end of the metered addition, the mixture was stirred for a further 2 h. Complete conversion of the SiH functions was established gas-volumetrically. The reaction mixture was then heated to 130 C. and stripped of volatiles for 1 h at 1 mbar. A clear, slightly yellowish liquid (step 1) was obtained.

[0092] A 5 L three-necked flask with precision glass stirrer and thermometer was charged with 1288 g of step 1 together with 621 g of -caprolactone (CAS: 502-44-3), 391 g of dilactide (CAS: 95-96-5) and 2.3 g of Kosmos 29 (tin catalyst from Evonik). The mixture was stirred at 140 C. for 5 h. A liquid polyester-polysiloxane block copolymer was obtained.

[0093] Block Copolymer C:

[0094] A 5 L three-necked flask with precision glass stirrer and thermometer was charged with 1175 g of step 1 from synthesis example 1 (see block copolymer A) together with 825 g of -caprolactone (CAS: 502-44-3), 500 g of -butyrolactone (CAS: 96-48-0) and 2.5 g of Kosmos 29 (tin catalyst from Evonik). The mixture was stirred at 140 C. for 5 h. A liquid polyester-polysiloxane block copolymer was obtained.

[0095] Block Copolymer D:

[0096] A 5 L three-necked flask with precision glass stirrer and thermometer was charged with 1288 g of step 1 from synthesis example 2 (see block copolymer B) together with 621 g of 8-caprolactone (CAS: 502-44-3), 391 g of -butyrolactone (CAS: 96-48-0) and 2.3 g of Kosmos 29 (tin catalyst from Evonik). The mixture was stirred at 140 C. for 5 h. A liquid polyester-polysiloxane block copolymer was obtained.

Example 2: Rigid PUR Foam

[0097] The following foam formulation was used for the performance comparison:

TABLE-US-00002 Proportion Component by weight Polyether polyol* 100 Catalyst** 2 Surfactant*** 2.5 Water 2 Cyclopentane 14 MDI**** 215 *Daltolac R 471 from Huntsman, OH value 470 mg KOH/g **Polycat 8 from Evonik Operations GmbH ***Polyester-polysiloxane block copolymers such as those described in example 1 or polyether siloxanes from Evonik Operations GmbH as reference ****Polymeric MDI, 200 mPa*s, 31.5% NCO, functionality 2.7.

[0098] The comparative foamings were carried out by manual mixing. This was done by weighing polyol, catalysts, water, surfactant and blowing agent into a beaker and mixing this with a disc stirrer (diameter 6 cm) at 1000 rpm for 30 s. The beaker was reweighed to determine the amount of blowing agent that had evaporated during the mixing operation and this was replenished. The MDI was then added and the reaction mixture stirred with the described stirrer at 2500 rpm for 7 s and immediately transferred to an open mould having dimensions of 27.51414 cm (WHD).

[0099] After 10 min, the foams were demoulded. One day after foaming, the foams were analysed. The pore structure and surface were assessed subjectively on a scale from 1 to 10, where 10 represents an (idealized) defect-free, very fine foam and 1 represents an extremely defective, coarse foam.

[0100] The results are compiled in the table below:

TABLE-US-00003 Pore Surfactant Surface structure Block copolymer A 7.0 7.0 Block copolymer B 7.0 7.0 Block copolymer C 7.5 7.5 Block copolymer D 7.0 8.0 Tegostab B 8486 7.0 6.0 Tegostab B 8462 7.5 7.0

[0101] The results show that it is possible with block copolymers A-D to achieve pore structures and foam qualities that are at the same level as or better than those of polyether siloxane-based foam stabilizers. Density, compressive strength and thermal insulation performance are affected only negligibly or not at all by the block copolymers of the invention and are at the same level as those of polyether siloxane-based foam stabilizers.

Example 3: Rigid PUR Foam

[0102] The following foam formulation was used for the performance comparison:

TABLE-US-00004 Proportion Component by weight Polyether polyol* 100 Catalyst** 1.4 Surfactant*** 3 Water 2.5 TCPP 60 1233zd 8 MDI**** 266 *Daltolac R 471 from Huntsman, OH value 470 mg KOH/g **Polycat 8 from Evonik Operations GmbH ***Polyester-polysiloxane block copolymers such as those described in example 1 or polyether siloxanes from Evonik Operations GmbH as reference ****Polymeric MDI, 200 mPa*s, 31.5% NCO, functionality 2.7.

[0103] The comparative foamings were carried out by manual mixing. This was done by weighing polyol, catalysts, water, surfactant, flame retardant and blowing agent into a beaker and mixing this with a disc stirrer (diameter 6 cm) at 1000 rpm for 30 s. The beaker was reweighed to determine the amount of blowing agent that had evaporated during the mixing operation and this was replenished. The MDI was then added and the reaction mixture stirred with the described stirrer at 2500 rpm for 7 s and immediately transferred to an open mould having dimensions of 27.51414 cm (WHD).

[0104] After 10 min, the foams were demoulded. One day after foaming, the fire behaviour was determined by the small-burner test (B2) in accordance with DIN 4102-1:1998-05.

[0105] The results are compiled in the table below:

TABLE-US-00005 Largest flame Surfactant height in mm Block copolymer A 140 Block copolymer B 130 Block copolymer C 140 Block copolymer D 140 Tegostab B 8486 150 Tegostab B 8462 160

[0106] The results show that it is possible with block copolymers A-D to achieve a lower flame height compared with conventional polyether siloxanes and thus an improvement in fire behaviour, and that it is possible to comply with the fire protection standard of min. B2.

[0107] All other use-relevant foam properties are affected only negligibly or not at all by the copolymers of the invention.

Example 4: Rigid (PIR) Polyisocyanurate Foam

[0108] The following foam formulation was used for the performance comparison:

TABLE-US-00006 Proportion Component by weight Polyester polyol* 100 Amine catalyst** 0.6 Potassium trimerization catalyst*** 3.5 Surfactant**** 2 Water 0.8 TCPP 5 Cyclopentane/isopentane 70:30 18 MDI***** 221 *Stepanpol PS 2352 from Stepan, OH value 250 mg KOH/g **Polycat 5 from Operations GmbH ***Kosmos 75 from Operations GmbH ****Polyester-polysiloxane block copolymers such as those described in example 1 or polyether siloxanes from Evonik Operations GmbH as reference *****Polymeric MDI, 200 mPa*s, 31.5% NCO, functionality 2.7.

[0109] The comparative foamings were carried out by manual mixing. This was done by weighing polyol, catalysts, water, surfactant, flame retardant and blowing agent into a beaker and mixing this with a disc stirrer (diameter 6 cm) at 1000 rpm for 30 s. The beaker was reweighed to determine the amount of blowing agent that had evaporated during the mixing operation and this was replenished. The MDI was then added and the reaction mixture stirred with the described stirrer at 3000 rpm for 5 s and immediately transferred to an open mould having dimensions of 27.51414 cm (WHD).

[0110] After 10 min, the foams were demoulded. One day after foaming, the foams were subjected to a cone calorimeter test in accordance with ISO 5660-1 AMD 1:2019-08, with the burning time determined at a heating rate of 25 kW/m.sup.2 as the time between the foam igniting and the flame being extinguished.

[0111] The results are compiled in the table below:

TABLE-US-00007 Surfactant Burning time in s Block copolymer A 83 Block copolymer B 151 Block copolymer C 49 Block copolymer D 32 Tegostab B 8462 545 Tegostab B 84504 440

[0112] The results show that it is possible with block copolymers A-D to achieve a shorter burning time compared with conventional polyether siloxanes and thus an improvement in fire behaviour. All other use-relevant foam properties are affected only negligibly or not at all by the copolymers of the invention.