IMPROVED CURATIVE COMPOSITION

Abstract

A curative resin containing at least 50 wt % of an epoxy phenolic resin comprising a mixture of a carboxylic hydrazide and a hydroxy substituted urone.

Claims

1. An epoxy resin composition comprising: a thermoset resin and a curative, said thermoset resin comprising at least 50 wt % of an epoxy phenolic resin; and said curative comprising a mixture of a carboxylic hydrazide and a hydroxy substituted urone.

2. The epoxy resin composition according to claim 1 in which the carboxylic acid hydrazide is adipic acid dihyrazide.

3. The epoxy resin composition according to claim 2 in which the urone is ortho-hydroxy fenuron.

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. A fibre reinforced composite comprising fibrous reinforcing filaments impregnated with the epoxy resin composition of claim 1.

13. (canceled)

14. (canceled)

15. A process for the production of a curable fibre reinforced composite material, which can be cured to form a cured material having a Tg of from 145 to 150° C., said process comprising the steps of: combining a fibrous material with a matrix of a resin composition comprising at least 50 wt % epoxy phenolic resin and said matrix containing a carboxylic acid hydrazide and a hydroxyl substituted urone, subjecting the matrix to a temperature from 140° C. to 180° C. for no more than 3 minutes.

16. The process according to claim 15 in which the carboxylic acid hydrazide is adipic acid dihydrazide.

17. The process according to claim 16 in which the urone is ortho-hydroxy fenuron.

Description

EXAMPLES 1 TO 5

[0081] The following formulations were prepared.

TABLE-US-00001 TABLE 3 Formulations of Examples 1 to 5 Component Example 1 Example 2 Example 3 Example 4 Example 5 SCT150 9.70 35.40 XD1000 9.70 YDPN638 16.50 27.60 88.20 GT6071 15.50 16.40 44.10 Epikote 828 13.58 9.00 16.40 44.10 DLS1840 46.00 Phenoxy 3.90 MX153 19.40 19.00 Aerosil R202 1.50 PAT656/83R 1.50 1.00 ADH-J 6.80 6.80 6.80 6.80 OHFU 5.00 5.00 5.00 U52 5.82 UR500 4.50 DICY 9.00

[0082] The formulations of Examples 1 to 5 were exposed to a temperature of 150° C. and the time to reach 95% cure and the E′Tg were measured and found to be as follows.

TABLE-US-00002 TABLE 4 Results for Examples 1 to 5. Measurement Example 1 Example 2 Example 3 Example 4 Example 5 Time to 95% cure 4.6 3.5 5.0 4.8 (minutes) E′Tg (° C.) 135 125 142 118 146

[0083] The following Examples show the effect of the curatives combination on time to reach 95% cure and E′Tg.

Examples 3 and 6 to 10

[0084] The following formulations were prepared.

TABLE-US-00003 TABLE 5 Formulations of Examples 3 and 6 to 10 Component Example 3 Example 6 Example 7 Example 8 Example 9 Example 10 SCT150 35.40 35.40 35.40 35.40 35.40 35.40 XD1000 YDPN638 GT6071 16.40 16.40 16.40 16.40 16.40 16.40 Epikote 828 16.40 16.40 16.40 16.40 16.40 16.40 DLS1840 Phenoxy MX153 19.00 19.00 19.00 19.00 19.00 19.00 Aerosil R202 PAT656/83R 1.00 1.00 1.00 1.00 1.00 1.00 ADH-J 6.80 6.80 6.80 6.80 6.80 6.80 OHFU 5.00 DIPPI 5.00 TODI 5.00 PDI 5.00 NDI 5.00 U52 5.00

[0085] The formulations of Examples 3 and 6 to 10 were exposed to a temperature of 150° C. and the time to reach 95% cure and the E′Tg were measured and found to be as follows (Table 6).

TABLE-US-00004 TABLE 6 Results for Examples 3 and 6 to 10 Measurement Example 3 Example 6 Example 7 Example 8 Example 9 Example 10 Time to 95% 3.5 5 6.5 6.5 4.5 4.5 cure (minutes) E′Tg (° C.) 142 120 145 0 100 130

Examples 11 to 13

[0086] Finally, the following formulations of Examples 11 to 13 were prepared.

TABLE-US-00005 TABLE 7 Formulations of Examples 11 to 13 Component Example 11 Example 12 Example 13 SCT150 34.2 20 33.8 XD1000 YDPN638 27.60 GT6071 16.4 16 15.50 Epikote 828 16.4 16 15.50 MY721 15 Phenoxy MX153 19 19.00 Aerosil R202 PAT656/83R 1 1 1.00 ADH-J 6.80 6.8 OHFU 6.2 6.2 6.2 U52 UR500 DICY 9.0

[0087] The formulations of Examples 11, 12 and 13 were exposed to a temperature of 150° C. and the time to reach 95% cure and the E′Tg were measured and found to be as follows.

TABLE-US-00006 TABLE 4 Results for Examples 15 to 17. Measurement Example 11 Example 12 Example 13 Time to 95% cure 2.4 1.9 1.7 (minutes) E′Tg (° C.) 142 140 138

[0088] These examples show that for the curative combination of a carboxylic hydrazide and a hydroxy substituted urone, and in particular of ortho-droxy fenuron and a hydrazide, an advantageous combination of a reduced time to 95% cure and increased E′Tg is achieved.