JPS61210090A - Production of diaryl phosphate metal salt - Google Patents

Abstract

PURPOSE:To obtain the titled metal salt useful as an agent for improving the physical properties of resins or an intermediate for various industrial chemicals, without using a large amount of water, in high yield, by reacting a diaryl phosphate compound with an alkali metal hydroxide. CONSTITUTION:The objective compound of formula III or formula IV can be produced by kneading (A) the diaryl phosphate compound of formula I or formula II (R1 and R2 are H or alkyl; M is alkali metal [e.g. bis(4-t-butylphenyl) phosphate] with (B) essentially equimolar amount of an alkali metal hydroxide (e.g. sodium hydroxide), optionally in the presence of <=50wt% organic solvent such as methanol based on the compound A, and reacting the components with each other in the presence of 0-100wt% water based on the compound A, generally for 30min-3hr. The reaction is carried out in the presence of preferably 5-50% water in the form of e.g. an aqueous solution of the compound B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an alkali metal diaryl phosphate salt, and more particularly to a method for producing an alkali metal salt of a diaryl phosphate by reacting a diaryl phosphate with an alkali metal hydroxide.

Diaryl phosphate alkali metal salts are extremely useful compounds as physical property improvers for synthetic resins or as raw material intermediates for various industrial chemicals.

As a method for producing diaryl phosphate alkali metal salts, a method of hydrolyzing diaryl phosphate monochloride in an alkaline aqueous solution is conventionally known, but the raw material diaryl phosphate monochloride contains triaryl phosphate and monoaryl phosphate as impurities. Due to the high content of acid dichloride, the purity of the product was low and required further purification. However, it is extremely difficult to purify alkali metal salts, and moreover, a large amount of water must be used, resulting in a disadvantage that the yield per batch is extremely low.

For this reason, JP-A No. 59-93088 discloses a method for obtaining a highly purified alkali metal salt of diaryl phosphate in high yield by hydrolyzing triaryl phosphate with an alkali metal hydroxide in an aqueous medium. Proposed. However, the method described in this publication requires a step to remove liberated phenol, which not only makes the operation complicated but also requires the use of a large amount of water, so the yield per batch is still low. It was only big.

In view of the current situation, the inventors of the present invention have conducted intensive studies to find a method for obtaining high-purity alkali metal salts of diaryl phosphates with simple operations and high yields. The present invention was achieved based on the discovery that the reaction proceeds extremely easily and does not require the use of large amounts of water, resulting in a significantly large yield per batch.

That is, in the present invention, a diaryl phosphate compound represented by the following formula (Ia) or (!b) is reacted with substantially equimolar amount of alkali metal hydroxide to form the following formula (If a
) or (nb), the reaction is carried out with respect to the diarylphosphate compound in the presence of 0 to 100% by weight of water. The manufacturing method is also presented.

R,R.

R+ R+ (wherein, R
2 and R2 each represent a hydrogen atom or an alkyl group, and M represents an alkali metal. ) Hereinafter, the manufacturing method of the present invention will be explained in more detail.

In the above formula, the alkyl groups represented by R9 and R2 include methyl, ethyl, prop, pyl, isopropyl, butyl, isobutyl, 5ec-butyl, t-butyl, amyl,
Examples include hexyl, octyl, isooctyl, 2-ethylhexyl, t-octyl, and the like.

Examples of the alkali metal represented by M include sodium, potassium, and lithium.

In the method of the present invention, water is produced by the reaction between the diaryl phosphate compound and the alkali metal hydroxide, so the reaction proceeds without adding water. The amount of water added is preferably 100% by weight or less, preferably 5 to 50% by weight based on the diarylphosphate.

If the amount of water added is 100% by weight or more, not only will the yield per batch be small, but the diaryl phosphate and/or the alkali metal salt will become sticky, making stirring difficult, and drying the product will be difficult. This is not preferable because it requires a lot of effort.

Although water may be added separately, it is generally preferable to add water as an aqueous solution of an alkali metal hydroxide.

The method for reacting the diaryl phosphate compound and the alkali metal hydroxide is to use any device and stir/
A method of mixing and kneading can be adopted. Examples of the equipment used in this case include a Nigoo, an extruder, a Blengoo, and a ball mill.

Further, although it depends on the apparatus used, a reaction time of 5 hours or less is sufficient, and is generally about 30 minutes to 3 hours.

When carrying out the method of the present invention, a small amount of an organic solvent may be added to facilitate stirring and mixing. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, and butanol; aliphatic or aromatic carbonized solvents such as hexane, heptane, octane, mineral spirits, benzene, toluene, xylene, ethylbenzene, cumene, and pseudocumene; Hydrogen etc. can be used. The amount of these organic solvents used is 100% by weight or less, preferably 50% by weight or less, based on the diarylphosphate compound, and the total amount of water and organic solvent is 20% by weight or less, preferably 100% by weight. It is as follows.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to specific examples, but the present invention is not limited by the following examples.

Example 1 Bis(4-t-butylphenyl)phosphate 1810
g (5 moles), sodium hydroxide 200 g (5 moles)
A solution of 500 g of water and 362 g of methanol were placed in a kneader and kneaded at room temperature for 1 hour. The mixture was then dried under reduced pressure and then ground to obtain 1910 g of white powder of bis(4-t-butylphenyl)phosphate sodium salt. The purity was 99.2% by potentiometric titration, and the yield in terms of purity was 98.7%.

Example 2 A solution of 1250 g (5 moles) of diphenyl phosphate, 200 g (5 moles) of sodium hydroxide and 500 g of water, and 250 g of methanol were placed in a kneader, and 1
Kneaded for hours. Next, it is dried under reduced pressure and then ground to give 1
349 g of diphenylphosphate sodium salt as a white powder was obtained.

(Purity 98.9%, yield 98.1%) Example 3 1390 g of bis(4-methylphenyl)phosphate (
5 moles), 200 g (5 moles) of sodium hydroxide and 5 moles of water
00 g of the solution and 278 g of methanol were placed in a kneader and kneaded for 1 hour at room temperature. The mixture was then dried under reduced pressure and then ground to obtain 1489 g of white powder of bis(4-methiphenyl)phosphate sodium salt. (Purity 99.0%, yield 98.3%) Example 4 1458 g (3 moles) of 2.2-methylenebis(4,6-di-t-butylphenyl) phosphate, 120 g (3 moles) of sodium hydroxide A solution of 300 g of water and 292 g of methanol were charged into a Nigu and kneaded at room temperature for 1 hour. After drying under reduced pressure and grinding, 1515 g of white powder of 2.2"-methylenebis(4,6-di-t-
Butylphenyl)phosphate sodium salt was obtained.

(Purity 99.3%, yield 98.6%) Example 5

Claims (1)

[Scope of Claims] A diaryl phosphate compound represented by the following formula (Ia) or (Ib) is reacted with substantially equimolar amount of alkali metal hydroxide to form the following formula (IIa) or (Ib). When producing the diaryl phosphate metal salt represented by IIb), the reaction is carried out at 0 to 1
1. A method for producing a diarylphosphate alkali metal salt, the method being carried out in the presence of 0.00% by weight of water. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I a)▲Mathematical formulas,
There are chemical formulas, tables, etc. ▼ (I b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IIa) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IIb) (In the formula, R_1 and R_2 are each a hydrogen atom or an alkyl group, and M represents an alkali metal.)