CAPROLACTAM-MODIFIED LIQUID MDI AND ITS USE IN POLYURETHANES

Abstract

The present invention is directed to a liquid, storage stable isocyanate composition (Q) comprising monomeric diphenyl methane diisocyanate (MDI) as component (q1) and an amide with a molecular weight of less than 200 g/mol as component (q2) in an amount of 0.1 to 5 wt.-% based on the sum of the weight of components (q1) and (q2) which adds up to 100 wt.-%, wherein the NCO-content is in the range of from 29.5 to 40.0 wt.-% based on the total weight of the respective isocyanate composition (Q). The present invention is also directed to a process for the manufacture of said liquid, storage stable isocyanate composition (Q) as well as the use of an amide with a molecular weight of less than 200 g/mol for the liquification of at room temperature solid isocyanates. Further, the present invention is directed to the use of an isocyanate composition (Q) of the invention for the synthesis of polyurethane foams, compact polyurethane elastomers or thermoplastic polyurethanes.

Claims

1.-22. (canceled)

23. A liquid, storage stable isocyanate composition (Q) comprising monomeric diphenyl methane diisocyanate (MDI) as component (q1) and an amide with a molecular weight of less than 200 g/mol as component (q2) in an amount of 0.1 to 5 wt.-% based on the sum of the weight of components (q1) and (q2) which adds up to 100 wt.-%, wherein the NCO-content is in the range of from 29.5 to 40.0 wt.-% based on the total weight of the respective isocyanate composition (Q).

24. The isocyanate composition (Q) according to claim 23, wherein the monomeric MDI is an isomer mixture with a 4,4′-MDI isomer content of at least 70 wt.-% based on the total amount of the isomer mixture.

25. The isocyanate composition (Q) according to claim 23, wherein the monomeric MDI is an isomer mixture with a 4,4′-MDI isomer content of at least 96 wt.-% based on the total amount of the isomer mixture.

26. The isocyanate composition (Q) according to claim 23, wherein the amide with a molecular weight of less than 200 g/mol is a lactam.

27. The isocyanate composition (Q) according to claim 23, wherein the amide with a molecular weight of less than 200 g/mol is selected from the group consisting of beta-Caprolactam, gamma-Caprolactam, delta-Caprolactam, epsilon-Caprolactam and Laurolactam.

28. The isocyanate composition (Q) according to claim 23, wherein the amide with a molecular weight of less than 200 g/mol is epsilon-Caprolactam.

29. The isocyanate composition (Q) according to claim 23, wherein the amide content is in the range of from 1 to 4 wt.-% based on the total weight of the sum of components (q1) and (q2).

30. The isocyanate composition (Q) according to claim 23, wherein the amide content is in the range of from 1.5 to 3 wt.-% based on the total weight of the sum of components (q1) and (q2).

31. The isocyanate composition (Q) according to claim 23, wherein the NCO-content is in the range of from 29.5 to 33 wt.-% based on the total weight of the isocyanate composition (Q).

32. The isocyanate composition (Q) according to claim 23, wherein the cloud point of the liquid isocyanate composition is in the range of from 7 to 35° C.

33. The isocyanate composition (Q) according to claim 23, wherein the cloud point of the liquid isocyanate composition is in the range of from 7 to 20° C.

34. The isocyanate composition (Q) according to claim 23, wherein the viscosity of the liquid isocyanate composition is in the range of from 4 to 5000 mPas measured at 40° C.

35. The isocyanate composition (Q) according to claim 23, wherein the isocyanate composition (Q) further comprises one or more additives selected from the group consisting of carbodiimide-modified isocyanates, uretdion-modified isocyanates, oligomeric MDI, polymeric MDI, prepolymers, solvent and plasticizer.

36. The isocyanate composition (Q) according to claim 35, wherein the amount of additives is in the range of from 0.1 to 40.0 wt.-% based on the total weight of the isocyanate composition (Q).

37. A process for the manufacture of a liquid, storage stable isocyanate composition (Q) according to claim 23, comprising reacting the monomeric MDI with the respective amount of the amide at a temperature in the range of from 20° C. to 100° C. for at least 1 min.

38. The process according to claim 37, wherein the temperature is in the range of from 45 to 80° C.

39. The process according to claim 37, wherein the reaction time is in the range of from 5 to 80 min.

40. A method comprising utilizing an amide with a molecular weight of less than 200 g/mol for the liquification of at room temperature solid isocyanates, optionally comprising monomeric diphenyl methane diisocyanate (MDI).

41. The method according to claim 40, wherein the solid isocyanate is monomeric 4,4′-MDI with a 4,4′-MDI isomer content of at least 70 wt.-%, based on the total amount of the isomer mixture, and the amount of the amide is in the range of from 0.1 to 5 wt.-% based on the sum of the weight of the solid isocyanate as component (q1) and the amide as component (q2).

42. A method comprising utilizing the isocyanate composition (Q) according to claim 23 for the synthesis of polyurethane foams, compact polyurethane elastomers or thermoplastic polyurethanes.

43. The method to claim 42, wherein the polyurethane foams are foams for dampening applications, sealants, adhesives, coatings and for footwear applications.

44. A method comprising utilizing the isocyanate composition (Q) according to claim 23 for stabilizing a composition containing at least one polyurethane prepolymer.

Description

EXAMPLES

1. Methods Used

1.1 Determination of the Cloud Point (Method 1)

[0125] The cloud point was determined using a rheological method using a rheometer of company Anton Paar GmbH, type MCR302 with parallel plates with a diameter of 25 mm and a gap between the plates of 2 mm.

[0126] The sample and the apparatus were heated to 50° C. After shearing for 120 s and at a frequency of rotation of 50 Hz, the temperature was lowered by 1° C./min to a temperature of −10° C.

[0127] The dynamic viscosity of the mixture increased with the formation of crystals of 4,4′-MDI. The cloud point measured is defined as the turning point of the curve of the dynamic viscosity.

[0128] The results obtained are in accordance with the results of optical methods for the determination of the cloud point, for example those described for fuels in ASTM D2500. A comparison of the results shows that the results of the rheological method are more accurate and have a higher reproducibility.

1.2 Determination of the Viscosity

[0129] The dynamic viscosity was determined according to DIN 53 018 using a frequency of rotation of 50 Hz after keeping the temperature of the sample at the respective temperature of the measurement for a time of 120 seconds.

2. Preparation of the Isocyanate Compositions

2.1 Examples Using Epsilon-Caprolactam (According to the Invention)

[0130] 500 g of 4,4′-diphenyl methane diisocyanate (MDI) (Lupranat ME) were added to a vessel and heated to a temperature in the range of about 60 to 80° C. Epsilon-Caprolactam was added in an amount as specified in table 1. The mixture was stirred for 60 minutes. A liquid composition was obtained.

[0131] The results of the examples are summarized in table 1.

TABLE-US-00001 TABLE 1 Caprolactam Viscosity Viscosity Example % in ME % Cloudpoint at 25° C. at 40° C. No. [wt.- %] NCO [° C.] [mPas] [mPas] 1.1 0 33.5 39.1 Solid 6 1.2 0.1 33.43 36.2 Solid 6 1.3 0.2 33.36 34.2 Solid 6 1.4 0.5 33.15 30.2 Solid 6 1.5 1 32.79 27.1 Solid 6 1.6 1.5 32.44 19.1 n.d. 7 1.7 1.8 32.22 17.9 n.d. 7 1.8 2 32.08 17.7 18 8 1.9 2.2 31.94 17.7 18 8 1.10 2.4 31.8 17 18 8 1.11 2.6 31.66 15.1 19 8 1.12 2.8 31.52 14.8 19 8 1.13 3 31.37 14.7 19 8 1.14 3.2 31.23 13.7 n.d. 8 1.15 3.4 31.09 13.3 n.d. 8 1.16 5 29.96 7.1 n.d. 9

2.2 Examples Using Methylethylketoxim (Comparative Examples)

[0132] 500 g of 4,4′-diphenyl methane diisocyanate (MDI) (Lupranat ME) were added to a vessel and heated to a temperature in the range of about 60 to 80° C. Methylethylketoxim (MEKO) was added in an amount as specified in table 2. The mixture was stirred for 60 minutes. A liquid composition was obtained.

[0133] The results of the examples are summarized in table 2.

TABLE-US-00002 TABLE 2 MEKO Viscosity Viscosity Example % in ME % Cloudpoint at 25° C. at 40° C. No [wt.-%] NCO [° C.] [mPas] [mPas] 2.1 0 33.5 39.1 Solid 6.3 2.2 1 32.68 33.4 Solid 6.1 2.3 2 31.87 30.4 Solid 6.8 2.4 3 31.05 28.3 Solid 7.5 2.5 4 30.23 23.4 n.d. 8.3 2.6 5 29.41 13.9 23 9.4 2.7 6 28.6 10.5 25 10.5 2.8 7 27.78 5.9 27 12 2.9 8 26.96 2.9 30 13.4

2.3. Examples of Using Other Amides

[0134] 500 g of 4,4′-diphenyl methane diisocyanate (MDI) (Lupranat ME) were added to a vessel and heated to a temperature in the range of about 60 to 80° C. The amide described in table 2 was added in an amount as specified in table 3. The mixture was stirred for 60 minutes. A liquid composition was obtained.

[0135] The sample was stored for 24 hours at 20° C. and checked visually for crystallization

[0136] The results of the examples are summarized in table 3.

TABLE-US-00003 TABLE 3 Example Amount Appearance after No. Amide [wt.-%] 24 hours at 20° C. 3.1 Gamma-Butyrolactam 2.5 Liquid, some crystal formation 3.2 Gamma-Butyrolactam 5 Liquid, some crystal formation 3.3 Gamma-Butyrolactam 10 Solid 3.4 Epsilon-Caprolactam 2.5 Liquid, clear 3.5 Epsilon-Caprolactam 5 Liquid, clear 3.6 Epsilon-Caprolactam 10 Liquid, clear 3.7 Laurolactam 2.5 Liquid, some crystal formation 3.8 Laurolactam 5 Liquid, some crystal formation 3.9 Laurolactam 10 Liquid, some crystal formation 3.10 Acetanilide 2.5 Solid 3.11 Acetanilide 5 Liquid, some crystal formation 3.12 Acetanilide 10 Liquid, clear 3.13 Methylacetamide 2.5 Liquid, some crystal formation 3.14 Methylacetamide 5 Liquid, clear 3.15 Methylacetamide 10 Liquid, clear 3.16 N-Ethylacetamide 2.5 Solid 3.17 N-Ethylacetamide 5 Solid 3.18 N-Ethylacetamide 10 Liquid, clear

CITED LITERATURE

[0137] U.S. Pat. No. 5,288,899 [0138] U.S. Pat. No. 7,666,971