PHOSPHORUS-CONTAINING FLAME RETARDANT MIXTURES, A PROCESS FOR PRODUCTION OF SAID MIXTURES AND USE OF SAID MIXTURES, AND ALSO EPOXY RESIN FORMULATIONS WHICH COMPRISE SAID FLAME RETARDANT MIXTURES

Abstract

Phosphorus-containing flame retardant mixtures, a process for production of said mixtures and use of said mixtures, and also epoxy resin formulations which comprise said flame retardant mixtures. The present invention relates to phosphorus-containing flame retardant mixtures, comprising individual flame retardants having in each case one or more functional groups of the formulae (I), (II) and (III), where, based on the total quantity of functional groups in the flame retardant mixture, 1 to 98 mol % of functional groups of the formula (I), 1 to 35 mol % of functional groups of the formula (II) and 1 to 98 mol % of functional groups of the formula (III) are present, and where R.sup.1 and R.sup.2 are identical or different and are mutually independently hydrogen, C.sub.1- to C.sub.12-alkyl, linear or branched, and/or C.sub.6- to C.sub.18-aryl and the entirety of (I), (II) and (III) is always 100 mol %.

##STR00001##

Claims

1. Phosphorus-containing flame retardant mixtures, comprising individual flame retardants having in each case one or more functional groups of the formulae (I), (II) and (III), ##STR00015## where, based on the total quantity of functional groups in the flame retardant mixture, 1 to 98 mol % of functional groups of the formula (I), 1 to 35 mol % of functional groups of the formula (II) and 1 to 98 mol % of functional groups of the formula (III) are present, and where R.sup.1 and R.sup.2 are identical or different and are mutually independently hydrogen, C.sub.1- to C.sub.12-alkyl, linear or branched, and/or C.sub.6- to C.sub.18-aryl and the entirety of (I), (II) and (III) is always 100 mol %, wherein, in the mixture of the formulae (I) and (II), the proportion T (in mol %) of formula (II) is calculated from T=[y/(x+y)]*100%, where x is the quantity of formula (I) and y is the quantity of formula (II), in each case in mol %, wherein T is 20 to 45 mol %.

2. Phosphorus-containing flame retardant mixtures according to claim 1, wherein R.sup.1 and R.sup.2 are identical or different and are mutually independently hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 3-methylbut-2-yl, 2-methylbut-2-yl, 2,2-dimethylpropyl, hexyl, heptyl, octyl, nonyl, decyl, cyclopentyl, cyclopentylethyl, cyclohexyl, cyclohexylethyl and/or phenyl.

3. Phosphorus-containing flame retardant mixtures according to claim 1, wherein R.sup.1 and R.sup.2 are identical or different and are mutually independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and/or tert-butyl.

4. Phosphorus-containing flame retardant mixtures according to claim 1, wherein they comprise 5 to 94 mol % of formula (I), 3 to 35 mol % of formula (II) and 3 to 92 mol % of formula (III), where the entirety of (I), (II) and (III) is always 100 mol %.

5. Phosphorus-containing flame retardant mixtures according to claim 1, wherein they comprise 25 to 90 mol % of formula (I), 5 to 30 mol % of formula (II) and 5 to 70 mol % of formula (III), where the entirety of (I), (II) and (III) is always 100 mol %.

6. (canceled)

7. (canceled)

8. (canceled)

9. Phosphorus-containing flame retardant mixtures according to claim 1, wherein the individual flame retardants having the functional groups (I), (II) and (III) in the flame retardant mixtures correspond to the formulae R.sup.21—O-(I), R.sup.21—O-(II) and/or R.sup.21—O-(III), where R.sup.21 means linear or branched alkyl structures having 2 to 8 carbon atoms and/or means polypropylene oxides of the type —[—CH(CH.sub.3)—CH.sub.2—O—].sub.k—H or —[—CH.sub.2—CH(CH.sub.3)—O—].sub.k—H and/or means polyethylene oxides of the type —[—CH.sub.2—CH.sub.2—O—].sub.k—H, where k is in each case an integer from 1 to 12.

10. Phosphorus-containing flame retardant mixtures according to claim 1, wherein the individual flame retardants having the functional groups (I), (II) and (III) in the flame retardant mixtures correspond to the formula D-O—[—CH.sub.2—CH.sub.2—O-].sub.r-E and/or D-O—[—CH(CH.sub.3)—CH.sub.2—O-].sub.r-E, where D and E can be identical or different and in each case represent the formula (I), (II) and/or (III), and r is an integer from 1 to 12.

11. Phosphorus-containing flame retardant mixtures according to claim 1, wherein the individual flame retardants having the functional groups (I), (II) and (III) in the flame retardant mixtures correspond to the formula (IV)
E-Q-D  (IV), where Q represents the following formula (V) ##STR00016## in which M is hydrogen or methyl and where D and E can be identical or different and in each case represent the formulae (I), (II) and/or (III) and L is an integer from 0 to 5.

12. Phosphorus-containing flame retardant mixtures according to claim 1, wherein the individual flame retardants having the functional groups (I), (II) and (III) in the flame retardant mixtures correspond to the formula (VI) ##STR00017## where F, G and J can be identical or different and in each case represent the formulae (I), (II) and/or (III), U is an integer between 1 and 12, R.sup.3 is hydrogen, methyl, ethyl, propyl and/or butyl, and R.sup.4 and R.sup.5 are mutually independently hydrogen, methyl and/or ##STR00018## where G and R.sup.3 are defined as above.

13. Phosphorus-containing flame retardant mixtures according to claim 1, wherein the individual flame retardants having the functional groups (I), (II) and (III) in the flame retardant mixtures correspond to the formula (VIII) ##STR00019## where F, G and J can be identical or different and in each case represent the formulae (I), (II) and/or (III).

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

20. Phosphorus-containing flame retardant mixtures according to claim 1, wherein they are non-halogenated in accordance with the standard IEC 61249-2-21 or are halogen-free.

21. Process for the production of flame retardant mixtures according to claim 1, wherein a reaction of at least one phosphinic acid, alkylphosphinic acid and/or dialkylphosphinic acid with the opened ring of an epoxide takes place in the presence of a catalyst, characterized in that the catalyst is ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium phosphate, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, tetrabutylphosphonium acetate, tetrabutylphosphonium acetate acetic acid complex, butyltriphenylphosphonium tetrabromobisphenate, butyltriphenylphosphonium bisphenate, butyltriphenylphosphonium bromide and/or butyltriphenylphosphonium bicarbonate.

22. (canceled)

23. Process according to claim 21, wherein a dialkylphosphinic acid is reacted with an epoxy novolac at 95° C. to 160° C. for 1 to 6 hours.

24. Process according to claim 21, wherein the flame retardant mixtures comprise at least one phosphinic ester structure of the formula R.sup.1R.sup.2P(═O)O— and the synthesis proceeds by way of a P—O—C bond at the opened epoxide ring, where R.sup.1 and R.sup.2 are defined as in claim 1.

25. Use of phosphorus-containing flame retardant mixtures according to claim 1 for the production of epoxy resin formulations.

26. Flame-retardant epoxy resin formulation, comprising at least one phosphorus-containing flame retardant mixture according to claim 1, epoxy resins, hardeners, accelerators, rheology additives and/or other additions.

27. Flame-retardant epoxy resin formulation according to claim 26, wherein the other additions are light stabilizers, colour pigments, dispersion additives, antifoams, blowing agents, foam-formers, additives for the improvement of mechanical strength, additives for the adjustment of thermal conductivity, glass spheres, glass powders, glass fibre, carbon fibre and/or thixotropizing agents.

28. Process for the production of epoxy resin formulations, comprising: reacting the phosphorus-containing flame retardant mixtures according to claim 1 with epoxy resin, hardener, accelerator, rheology additive and optionally other additions.

29. Process according to claim 28, wherein no solvents are used.

30. Use of epoxy resin formulations according to claim 26 for, or in, flame-retardant composite components, adhesives, pastes, foams, foam compositions, sealing compositions, hotmelt adhesives, fillers, potting compositions, trowelling compositions, finishing mats, coating systems, fibres, prepregs, masking lacquers for soldering, thermally conductive layers, thermally conductive pastes, shock-absorber layers, LEDs, sensors, insulating applications, circuit boards, antennas, and also in coating systems.

Description

Examples 1 to 4: Bifunctional Epoxy Resins

Example 1

[0111] 802 g of DGEBA are used as initial charge and heated to 130° C. in a flask apparatus with stirrer, reflux condenser, dropping funnel, thermometer and nitrogen supply. 0.1 m % (mass percent, based on total mass of DEPS and DGEBA) of ETPPI is then added, followed by 258 g of DEPS, whereupon an exothermic reaction is observed. Stirring is then continued for 2 h, and the resultant epoxy resin is discharged in the form of hot liquid.

Example 2 (Comparative)

[0112] The reaction is analogous to that of Example 1, but without ethyltriphenylphosphonium iodide as catalyst.

Example 3

[0113] By analogy with Example 1, 1000 g of DGEBA are used as initial charge and heated to 130° C., then 0.1 m % of ethyltriphenylphosphonium iodide is added, followed by 642 g of diethylphosphinic acid, whereupon an exothermic reaction can be observed. Stirring is then continued for 2 h, and the resultant epoxy resin is discharged in the form of hot liquid.

Example 4 (Comparative)

[0114] The reaction is analogous to that of Example 3, but without ethyltriphenylphosphonium iodide as catalyst.

TABLE-US-00004 Example 2 Example 4 Example 1 (comparative) Example 3 (comparative) DGEBA (g) 802 802 1000 1000 Cat 1 yes no yes no P1 (g) 258 258  642  642 m % of P    6.2    6.2    9.7    9.7 EEW (g/mol) 482 700 6000 7000 31P-NMR 61.1 ppm (I); 61.3 ppm (I); 61.1 ppm (I); 61.3 ppm (I); (DMSO, 61.7 ppm (II) 61.8 ppm (II) 61.7 ppm (II) 61.8 ppm (II) decoupled) Viscosity (at 3450  5800  16 200   16 600   80° C., 5 s.sup.−1) Isomer ratio I/II 70/30 90/10 72/28 86/14 (from 31P-NMR) X  35  59  68  82 Y  15  7  26  13 Z  50  34   6   5 T = Y/(X + Y)*100% 30% 10% 28% 14% P dimer by-product no yes no yes

[0115] In each of the Examples 1 and 3, the products of the invention have a higher proportion of isomer II. The higher proportion of II is discernible from the value of T, which provides the ratio of Y to (X+Y). In each case, therefore, the product of the invention has a lower viscosity than the product of the respective comparative example.

[0116] In addition, the products of the invention advantageously comprise no phosphorus-containing dimeric by-products whose unfavourable properties such as increased level of migration and toxicity would render the final product useless.

Examples 5 to 15: Reaction of Polyfunctional Epoxides

Example 5

[0117] 1000 g of epoxy novolac (DEN® 438 with an EEW of 180 g/mol) are used as initial charge and heated to 130° C. in a 2000 ml five-necked flask apparatus with stirrer, reflux condenser, dropping funnel, thermometer and nitrogen supply. 0.1 m % of ethyltriphenylphosphonium iodide (based on total mass) is then added, followed by 73 g of diethylphosphinic acid. Stirring is then continued for 120 min, and the epoxy resin produced is discharged in the form of hot liquid.

[0118] The method for Examples 6 to 9 is the same as that for Example 5, but in each case the quantities of diethylphosphinic acid used are as shown in Table 2.

Example 10

[0119] The production process is as in Example 8, but with methyltriphenylphosponium iodide as catalyst instead of ethyltriphenylphosphonium iodide.

Example 11

[0120] The production process is as in Example 8, but with 286 g of ethylmethylphosphinic acid instead of diethylphosphinic acid.

Example 12 (Comparative)

[0121] The production process is as in Example 6, but no catalyst was used.

Example 13 (Comparative)

[0122] The production process is as in Example 8, but no catalyst was used.

Example 14 (Comparative)

[0123] The production process is as in Example 9, but no catalyst was used.

TABLE-US-00005 TABLE 2 Examples 5 to 11 of the invention and comparative Examples 12 to 15 12 13 14 15 Example 5 6 7 8 9 10 11 (comp.) (comp.) (comp.) (comp.) Epoxy novolac (g) 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 Cat 1 yes yes yes yes yes yes no no no no Cat 2 yes P-1 (diethyl) 73 155 210 335 568 335 155 335 568 0 P-2 (MeEt) 286 m % of P 1.7 3.4 4.2 6.4 9.2 6.4 6.4 3.2 6.4 9.2 0 EEW (g/mol) 225 273 328 496 2700 491 503 332 605 about 181 4000 Viscosity 11 20 26 36 134 30 39 29 48 165 2 (Pas @ 80° C., 5 s.sup.−1) Isomer ratio I/II 62/38 67/33 59/41 69/31 70/30 75/25 69/31 95/5 93/7 92/8 — X 9 16 20 36 61 38 37 36 58 83 0 Y 5 8 14 16 26 13 17 2 2 8 0 Z 86 76 66 48 13 49 46 62 4 9 100 T 36% 33% 41% 31% 30% 25% 31% 5% 3% 9% — P dimer no no no no no no no yes yes yes no

[0124] The above table reveals, with comparable phosphorus content, that the epoxy resins of Examples 5 to 11 produced according to the invention in each case have a higher proportion of isomer II than the products of the respective comparative Examples 12 to 15.

[0125] The products of the invention moreover in each case have a lower viscosity than the product of the respective comparative example with comparable phosphorus content, and therefore the products of the invention provide a simple, or the only, method of achieving solvent-free processing. The products of the invention advantageously comprise no phosphorus-containing dimeric by-products whose unfavourable properties such as increased level of migration and toxicity would render the final product useless.

Examples 16 to 19 of the Invention

Example 16 (with Monofunctional Epoxide)

[0126] 100.0 g of tert-butyl glycidyl ether and 0.1 m % of ethyltriphenylphosphonium iodide (based on total content) are used as initial charge and heated to 120° C. under nitrogen in a reaction flask with stirrer, reflux condenser, dropping funnel and thermometer, and then 91.8 g of diethylphosphinic acid are slowly added dropwise and stirring is continued for 30 minutes. This gives a colourless liquid product.

Example 17 (with a Trifunctional Heterocyclic and Nitrogen-Containing Epoxide)

[0127] 100.0 g of triglycidyl isocyanurate (TGIC) are used as initial charge and melted in a glass flask with reflux condenser, thermocouple, nitrogen supply and stirrer. 0.1 m % of ethyltriphenylphosphonium iodide (based on total content) is then added and the mixture is stirred, the temperature in the flask is increased to 130° C., and 41.0 g of diethylphosphinic acid are slowly added, with stirring and under a stream of nitrogen, and the mixture is kept at 130° C. for 30 min. The product is then discharged in the form of a warm liquid, and cooled.

Example 18 (with a Trifunctional Heterocyclic and Nitrogen-Containing Epoxide)

[0128] The procedure is as in Example 17, but 123.0 g of diethylphosphinic acid are reacted (instead of 41.0 g).

Example 19 (Difunctional Epoxide: Butanediol Diglycidyl Ether)

[0129] 100.0 g of butanediol diglycidyl ether are used as initial charge in a glass flask with thermometer, nitrogen supply, dropping funnel, condenser and stirrer, and 0.1 m % of ethyltriphenylphosphonium iodide (based on total content) are added, and the mixture is stirred. 120.8 g of diethylphosphinic acid are now added dropwise at a temperature of 130° C. After the reaction has continued for 30 min, the transparent product, which has good flowability, is cooled and discharged.

Example 20 (Comparative, Difunctional Epoxide: Butanediol Diglycidyl Ether)

[0130] 100.0 g of butanediol diglycidyl ether are used as initial charge in a glass flask with thermometer, nitrogen supply, dropping funnel, condenser and stirrer, and the mixture is stirred. 120.8 g of diethylphosphinic acid are added dropwise at a temperature of 130° C. After the reaction has continued for 30 min, the product is cooled and discharged.

TABLE-US-00006 TABLE 3 Examples 16 to 19 and Example 20 (comparative) 20 Example 16 17 18 19 (comp.) tert-Butyl glycidyl 100  ether (g) TGIC (g) 100  100  Butanediol diglycidyl 100  100  ether (g) Cat 1 yes yes yes yes no P-1 (diethylphosphinic   91.8   41.0 123   120.8  120.8 acid) (g) m % of P   11.5   7.6 14   13.9   13.9 31P-NMR 60.7 ppm 60.9 ppm 60.9 ppm 60.9 ppm 60.9 ppm (isomer I); (isomer I); (isomer I); (isomer I); (isomer I); 60.6 ppm 61.1 ppm 61.1 ppm 61.2 ppm 61.2 ppm (isomer II) (isomer II) (isomer II) (isomer II) (isomer II) EEW (g/mol) about 2000 221  about 5000 about 2500 about 4900 Viscosity (mPas @ 20 11 000    7500  120  255  80° C., 5 s−1) Isomer ratio 64/36 67/33 66/34 63/37 82/18 A/B (from 31P-NMR) X 58 25 61 57 78 Y 33 12 31 34 17 Z  9 63  7  9  5 T = Y/(X + Y)*100% 36% 33% 34% 37% 18% Phosphorus-containing no no no no yes dimeric by-product

[0131] The examples in the above table reveal in each case for the inventive products 16 to 19 a higher proportion of isomer II than in the product of comparative Example 20.

[0132] The inventive product 19 moreover respectively has a lower viscosity than the product of comparative Example 20, thus facilitating solvent-free processing.