Mixtures Of Diphosphinic Acids And Alkylphosphinic Acids, A Process For The Preparation Thereof And The Use Thereof

Abstract

Mixtures of diphosphinic acids and alkylphosphinic acids, a process for preparation thereof and use thereof

The invention relates to mixtures of at least one diphosphinic acid of the formula (I)

##STR00001##

in which R.sup.1, R.sup.2 are each H, C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.6-C.sub.18-aryl, C.sub.7-C.sub.18-alkylaryl R.sup.4 is C.sub.1-C.sub.18-alkylene, C.sub.2-C.sub.18-alkenylene, C.sub.6-C.sub.18-arylene, C.sub.7-C.sub.18-alkylarylene
with at least one alkylphosphinic acid of the formula (II)

##STR00002##

in which R.sup.3 is C.sub.1-C.sub.18-alkyl, C.sub.2-C.sub.18-alkenyl, C.sub.6-C.sub.8-aryl, C.sub.7-C.sub.18-alkylaryl.

The invention also relates to a process for preparing these mixtures and to the use thereof.

Claims

1.-20. (canceled)

21. An intermediate for further syntheses, a binder, a crosslinker or accelerator in the curing of epoxy resins, polyurethanes and unsaturated polyester resins, a polymer stabilizer, a crop protection composition, a sequestrant, a mineral oil additive, an anticorrosive, a washing compound, a cleaning composition or an electronic composition comprising a mixture including at least one diphosphinic acid of the formula (I) ##STR00005## wherein R.sup.1 and R.sup.2 are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl or a mixture thereof; R.sup.4 is ethylene, butylene or hexylene; with at least one alkylphosphinic acid of the formula (II) ##STR00006## wherein R.sup.3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl or a mixture thereof.

22. A flame retardant, a flame-retardant polymer molding composition, a flame retardant for rendering polyester and pure and blended cellulose fabrics flame-retardant by impregnation, or as a synergist comprising a mixture including at least one diphosphinic acid of the formula (I) ##STR00007## wherein R.sup.1, R.sup.2 are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl or a mixture thereof; R.sup.4 is ethylene, butylene or hexylene; with at least one alkylphosphinic acid of the formula (II) ##STR00008## wherein R.sup.3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl or a mixture thereof.

23.-24. (canceled)

Description

EXAMPLE 1 PREPARATION OF ETHYLPHOSPHINIC ACID

[0093] At room temperature, a three-neck flask with stirrer and jacketed coil condenser is initially charged with 5852 g of tetrahydrofuran and degassed while stirring and passing nitrogen through, and all further reactions are executed under nitrogen. Then 70 mg of tris(dibenzylideneacetone)dipalladium and 95 mg of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene are added and the mixture is stirred for a further 15 minutes, and 198 g of phosphinic acid in 198 g of water are added. The reaction solution is transferred into a 2 l Bchi reactor. While stirring the reaction mixtures, the reactor is charged with ethylene to 2.5 bar and the reaction mixture is heated to 80 C. After 56 g of ethylene have been absorbed, the mixture is cooled to room temperature and free ethylene is burnt off.

[0094] The reaction mixture is freed from the solvent on a rotary evaporator at a maximum of 60 C. and 350-10 mbar. 300 g of demineralized water are added to the residue, and the mixture is stirred under nitrogen atmosphere at room temperature for 1 hour. The resulting residue is filtered and the filtrate is extracted with 200 ml of toluene. The aqueous phase is freed from the solvent on a rotary evaporator at a maximum of 60 C. and 250-10 mbar.

[0095] 31.sub.P NMR (D.sub.2O, coupled): doublet of multiplet, 36.7 ppm; ethylphosphinic acid.

EXAMPLE 2

[0096] 0.5 mol of ethylphosphinic acid (prepared according to example 1) are initially charged in butanol as a solvent and inertized with a nitrogen gas stream while stirring for 30 minutes and heated to 80 C. Acetylene is passed through the reaction solution at 1 l/h, and 0.2 mol % of initiator is metered in over 3 hours. After a continued reaction period of 30 minutes, the acetylene feed is stopped and acetylene is driven out of the apparatus with nitrogen. After the reaction mixtures have been cooled, the solid formed is filtered off with suction and redispersed with 75 g of acetone, washed and dried in a vacuum drying cabinet at 100 C. for 4 hours. In a yield of 62%, 33.2 g of a mixture of ethylene-1,2-bis(ethylphosphinic acid) (99.9% by weight) and ethylphosphinic acid (0.1% by weight) are obtained.

EXAMPLE 3

[0097] 0.5 mol of ethylphosphinic acid (prepared according to example 1) are initially charged in butanol as a solvent and inertized with a nitrogen gas stream while stirring for 30 minutes and heated to 80 C. Acetylene is passed through the reaction solution at 1 l/h, and 0.2 mol % of initiator is metered in over 2.5 hours. After a continued reaction period of 30 minutes, the acetylene feed is stopped and acetylene is driven out of the apparatus with nitrogen. After the reaction mixture has been cooled, the solid formed is filtered off with suction and redispersed with 75 g of acetone, washed and dried in a vacuum drying cabinet at 100 C. for 4 hours. In a yield of 64%, 34.2 g of a mixture of ethylene-1,2-bis(ethylphosphinic acid) (98% by weight) and ethylphosphinic acid (2% by weight) are obtained.

EXAMPLE 4

[0098] 0.5 mol of ethylphosphinic acid (prepared according to example 1) are initially charged in butanol as a solvent and inertized with a nitrogen gas stream while stirring for 30 minutes and heated to 80 C. Acetylene is passed through the reaction solution at 1 l/h, and 0.2 mol % of initiator is metered in over 2 hours. After a continued reaction period of 30 minutes, the acetylene feed is stopped and acetylene is driven out of the apparatus with nitrogen. After the reaction mixtures have been cooled, the solid formed is filtered off with suction and redispersed with 75 g of acetone, washed and dried in a vacuum drying cabinet at 100 C. for 4 hours. In a yield of 64%, 33.8 g of a mixture of ethylene-1,2-bis(ethylphosphinic acid) (90% by weight) and ethylphosphinic acid (10% by weight) are obtained.

EXAMPLE 5

[0099] 0.5 mol of ethylphosphinic acid (prepared according to example 1) are initially charged in butanol as a solvent and inertized with a nitrogen gas stream while stirring for 30 minutes and heated to 60 C. Acetylene is passed through the reaction solution at 1 l/h, and 0.12 mol % of initiator is metered in over 2 hours. After a continued reaction period of 30 minutes, the acetylene feed is stopped and acetylene is driven out of the apparatus with nitrogen. After the reaction mixture has been cooled, the solid formed is filtered off with suction and redispersed with 75 g of acetone, washed and dried in a vacuum drying cabinet at 100 C. for 4 hours. In a yield of 72%, 36.6 g of a mixture of ethylene-1,2-bis(ethylphosphinic acid) (60% by weight) and ethylphosphinic acid (40% by weight) are obtained.

EXAMPLE 6

[0100] 0.5 mol of ethylphosphinic acid (prepared according to example 1) are initially charged in butanol as a solvent and inertized with a nitrogen gas stream while stirring for 30 minutes and heated to 60 C. Acetylene is passed through the reaction solution at 1 l/h, and 0.05 mol % of initiator is metered in over 2 hours. After a continued reaction period of 30 minutes, the acetylene feed is stopped and acetylene is driven out of the apparatus with nitrogen. After the reaction mixture has been cooled, the solid formed is filtered off with suction and redispersed with 75 g of acetone, washed and dried in a vacuum drying cabinet at 100 C. for 4 hours. In a yield of 74%, 37.2 g of a mixture of ethylene-1,2-bis(ethylphosphinic acid) (50% by weight) and ethylphosphinic acid (50% by weight) are obtained.

Method for Producing Polymer Moldings:

a) Preparation of Phosphorus-Modified Epoxy Resin

[0101] A 2 l five-neck flask apparatus is initially charged with 1000 g of the epoxy resin (e.g. Beckopox EP 140). It is heated to 110 C. for one hour and volatile components are removed under reduced pressure. Thereafter, the reaction mixture is inertized with nitrogen and the temperature in the flask is increased to 170 C. 118 g of the mixtures of the phosphorus compounds are added in each case, while stirring under flowing nitrogen, and an exothermic reaction is observed. The resulting resin is yellow in color and free-flowing.

b) Production of Epoxy Resin Specimens

[0102] 100 parts of the phosphorus-modified epoxy resin are mixed with one corresponding OH equivalent of phenol novolac (hydroxide equivalents 105 g/mol, melting point 85-95 C.) and heated to 150 C. This liquefies the components. The mixture is stirred gradually until a homogeneous mixture has formed and is allowed to cool to 130 C. Then 0.03 part 2-phenylimidazole is added and the mixture is stirred once again for 5-10 min. Thereafter, the mixture is poured warm into a dish and cured at 140 C. for 2 h and at 200 C. for 2 h.

c) Production of Epoxy Resin Laminate

[0103] 100 parts phosphorus-modified epoxy resin as per b) are added to 63 parts acetone and 27 parts Dowanol PM, and the appropriate amount of phenol resin is added. The mixture is left to stir for 30 min and then 2-phenylimidazole is added. Thereafter, the mixture is filtered through a 400 m sieve in order to remove excess resin particles. Then a woven glass fabric (7628 type, 203 g/m.sup.2) is immersed into the solution until complete wetting of the fabric has taken place. The wetted fabric is pulled out of the mixture and excess resin is removed. Thereafter, the wetted fabric is initially cured in stages in a drying cabinet for a brief period at temperatures up to 165 C. and then fully cured in a heated press. The resin content of the cured laminates is 30-50% by weight. The thermal expansion of the molding produced, a laminate, is determined to ASTM E831-06.

EXAMPLE 7

[0104] According to the method for producing a polymer molding, 100% by weight of a bisphenol A resin is used to produce a laminate. This has the values for the coefficient of thermal expansion reported in the table.

EXAMPLE 8

[0105] Pure ethylene-1,2-bis(ethylphosphinic acid) is obtained according to example 2 with subsequent washing of the product with organic solvents.

[0106] According to the method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of ethylene-1,2-bis(ethylphosphinic acid) is used to produce a molding.

EXAMPLE 9

[0107] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of ethylphosphinic acid (obtained according to example 1) is used to produce a molding.

EXAMPLE 10

[0108] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid according to example 2 is used to produce a molding.

EXAMPLE 11

[0109] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid from example 3 is used to produce a molding.

EXAMPLE 12

[0110] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid from example 4 is used to produce a molding.

EXAMPLE 13

[0111] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid from example 5 is used to produce a molding.

EXAMPLE 14

[0112] According to the general method for producing a polymer molding, a composition composed to 90% by weight of bisphenol A resin with hardener and catalyst and 10% by weight of the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid from example 6 is used to produce a molding.

[0113] The results are reproduced in the following table:

TABLE-US-00002 Composition Coefficient of polymer Mixture of of thermal system/ ethylene-1,2-bis- expansion substance (ethylphosphinic acid)/ 0-100 [ppm/ C.] Example mixture ethylphosphinic acid Z X Y 7 100:0 69 20 7 8 90:10 100:0 68 20 7 9 90:10 0:100 70 21 7 10 90:10 99.9:0.1 66 18 5 (from example 2) 11 90:10 98:2 63 16 5 (from example 3) 12 90:10 90:10 60 16 5 (from example 4)

[0114] The mixtures from examples 5 and 6 likewise give rise to a decrease in the coefficients of thermal expansion.

[0115] Compared to the pure laminate (example 7), there is a decrease in the values for the laminate comprising the inventive mixture of ethylene-1,2-bis(ethylphosphinic acid) and ethylphosphinic acid; thermal expansion is thus very low. An increase in the ethylphosphinic acid content brings about a further improvement.

[0116] Compared to the prior art (example 7), the inventive mixtures exhibit lower values for the coefficient of thermal expansion, meaning that the inventive products lead to lower expansion of the moldings produced and hence meet the demands on dimensional stability.

EXAMPLE 15: PRODUCTION OF POLYESTER-BASED POLYMER MOLDINGS

a) Preparation of Phosphorus-Modified Polyethylene Terephthalate

[0117] 1000 g of dimethyl terephthalate are transesterified with 720 ml of ethylene glycol and 230 mg of Mn(OCOCH.sub.3).sub.4*4H.sub.2O at temperatures of 170-220 C. under a nitrogen atmosphere. After the methanol has been separated out, 17.2 g of the inventive mixture from example 4 are added at 220 C. and, after addition of 350 mg of Sb.sub.2O.sub.3, the reaction vessel is heated further to 250 C. and a vacuum is applied simultaneously. The polymerization is effected at 0.2 mm Hg and 287 C. within 2 hours. The resulting product has a melting point of 240-244 C. and a phosphorus content of 0.5%.

b) Production of Polymer Moldings

[0118] The aforementioned polymer pellets are mixed with any additives and they are incorporated in a twin-screw extruder (model: Leistritz LSM 30/34) at temperatures of 250 to 290 C. (PET-GR). The homogenized polymer strand was drawn off, cooled in a water bath and then pelletized. After sufficient drying, the molding compositions were processed on an injection molding machine (model: Aarburg Allrounder) at melt temperatures of 250 to 300 C. (PET-GR) to give test specimens. The UL 94 fire class and the LOI were determined on test specimens of thickness 1.6 mm. Moldings of thickness 1.6 mm result in V-0 and an LOI of 28%.