JP2971740B2 - Method for producing phosphate ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phosphoric acid ester which, when compounded with a resin, provides a flame-retardant effect and excellent coating adhesion.

[0002]

2. Description of the Related Art The most commonly used method for making a resin flame-retardant is to add a flame retardant such as an inorganic hydroxide, an organic halide or a phosphoric ester.
Of these, phosphate esters are particularly effective for resins containing an oxygen atom in the molecule, and are widely used. Industrially important phosphate ester flame retardants include triphenyl phosphate (TPP) and tricresyl phosphate (TC
No. 51-39, which has improved the volatility of triaryl phosphates and triaryl phosphates such as P).
No. 271, Japanese Patent Publication No. 54-32818, Japanese Patent Publication No. 62-2
No. 5706 and the like, and polyphosphoric acid aryl esters in which phosphorus atoms are cross-linked with divalent phenols, and the like.

[0003] These phosphate esters are usually synthesized by the dehydrochlorination reaction of phosphorus oxychloride and the corresponding monohydric phenols and / or dihydric phenols. Phosphorous oxychloride is extremely easy to react with water. In order to easily cause a dehydrochlorination reaction, the above-mentioned ester synthesis reaction has conventionally been performed under water-free conditions. On the other hand, recently, when various thermoplastic resins are used for exterior materials and other various structural materials due to their moldability and recyclability, good appearance of the molded products is strongly required, and they are used after being painted. There are many things. In order to increase the affinity between the resin surface and the paint for coating that is uniform and difficult to peel off, that is, to impart coating adhesion,
Surface modification and use of additives have been performed.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for producing an aryl phosphate ester which can impart excellent paint adhesion as well as flame retardancy by being added to a resin.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, when performing a dehydrochlorination reaction between phosphorus oxychloride and phenols, a specific concentration of water was added to the reaction system. Was found to significantly improve the coating adhesion of the resin composition to which the phosphate ester formed was added, and completed the present invention.

That is, the present invention relates to a method for producing a phosphate ester by a dehydrochlorination reaction of phosphorus oxychloride and monohydric phenols and / or dihydric phenols. A method for producing a phosphoric acid ester, characterized in that 10 to 2,000 wt ppm of water is present relative to the class. In the production of phosphoric esters, there has been no technique for adjusting the water concentration of the raw material to change the properties of the product, especially the coating adhesion.

The raw material monohydric phenols are represented by the following general formula having only one hydroxyl group directly bonded to an aromatic ring.

[0008]

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Wherein R is an arbitrary substituent other than a hydroxyl group, n is an integer of 1 to 5, and when n is 2 or more, a plurality of Rs may be the same or different from each other. In compounds, for example, phenol, cresol, xylenol, trimethylphenol, ethylphenol, methyl-ethylphenol, diethylphenol, propylphenol, isopropylphenol, methyl-propylphenol, ethyl-propylphenol, dipropylphenol, butylphenol, t-butylphenol, Methoxyphenol, ethoxyphenol, nitrophenol, dichlorophenol, pentachlorophenol, bromophenol, dibromophenol, pentabromophenol, α-naphthol, β-naphthol,
Hydroxydiphenyl and the like, but phenol,
Cresol and xylenol are particularly preferred.

The other raw material, a dihydric phenol, is represented by the following general formula having two hydroxyl groups directly bonded to an aromatic ring.

[0011]

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Wherein R ′ is a divalent aromatic group, such as catechol, resorcinol,
Examples thereof include hydroquinone, biphenyl-3,3 ′ diol, biphenyl-4,4 ′ diol, bisphenol A, bisphenol F, bisphenol S, and tetrabromobisphenol A, with hydroquinone, resorcinol and bisphenol A being particularly desirable.

The amount of water present in the reaction system is 10 to 2 with respect to the total amount of monohydric phenols and dihydric phenols as raw materials.
000 wtppm is preferable, and 100 to 50
A range of 0 wtppm is more preferred. At 10 wtppm or less, there is no effect of improving coating adhesion,
If it is more than m, the resin will deteriorate during molding. Moisture
It may be mixed with a monohydric phenol and / or a dihydric phenol in advance and then subjected to a reaction, or may be separately added after charging the phosphorus oxychloride and the monohydric phenol and / or a dihydric phenol. May be.

The method of the ester synthesis reaction is not particularly limited, but can be carried out, for example, by the following well-known method. That is, the reaction is carried out for 1 to 20 hours at a reaction temperature of 100 to 200 ° C. in the absence of a catalyst or in the presence of a Lewis acid catalyst while removing hydrochloric acid as a by-product. In the case of producing an aryl polyphosphate, a predetermined amount of a monohydric phenol or a dihydric phenol is reacted with phosphorus oxychloride to form an intermediate, and if necessary, impurities are separated by distillation. A general method is to add raw materials to complete the reaction. In this case, the water may be added at the time of the first reaction for producing the intermediate, may be added at the time of the second reaction for completing the reaction, or may be added separately for both.

Examples of the phosphate ester produced by the method of the present invention include, for example, triphenyl phosphate, tricresyl phosphate, trixylyl phosphate, diphenylcresyl phosphate, phenyldicresyl phosphate, diphenylxylyl phosphate, dicresylxylyl phosphate. , Phenyldixylylphosphate, phenylcresylxylylphosphate, cresyldixylylphosphate, tri (ethylphenyl) phosphate, diphenyl (ethylphenyl) phosphate, phenyldi (ethylphenyl) phosphate, dicresyl (ethylphenyl) phosphate, diphenyl (npropyl) Phenyl) phosphate, diphenyl (isopropylphenyl) phosphate, diphenyl (nbutylphenyl) phosphate , Diphenyl (isobutylphenyl) phosphate, diphenyl (t-butylphenyl) phosphate, phenyldi (n-propylphenyl)
Triaryl phosphates such as phosphate, phenyldi (isopropylphenyl) phosphate, phenyldi (nbutylphenyl) phosphate, phenyldi (isobutylphenyl) phosphate, phenyldi (tbutylphenyl) phosphate, trinaphthylphosphate, diphenylnaphthylphosphate and trisdiphenylphosphate; Resorcinol-polyphenyl phosphate, resorcinol-polycresyl phosphate,
Resorcinol-polyxylyl phosphate, hydroquinone-polyphenyl phosphate, hydroquinone-polycresyl phosphate, hydroquinone-polyxylyl phosphate, bisphenol A-polyphenyl phosphate, bisphenol A-polycresyl phosphate,
Bisphenol A-polyxylyl phosphate, bisphenol F-polyphenyl phosphate, bisphenol F-polycresyl phosphate, bisphenol F-
Polyphosphate aryl esters represented by the following general formula, such as polyxylyl phosphate, bisphenol S-polyphenyl phosphate, bisphenol S-polycresyl phosphate, and bisphenol S-polyxylyl phosphate

[0016]

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[In the formula, Ar ¹ , Ar ² , Ar ³ , and Ar ⁴ are the same or different and each is a phenyl group or an aryl group in which 1 to 3 C _{1 to} C ₄ alkyl groups are substituted. Is

[0018]

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Wherein A is a bond, a sulfone group or C
_{A 1 to} C ₄ alkylidene group or an alkylene group), and n is an integer of 1 to 100. And the like, but resorcinol-polyphenyl phosphate, resorcinol-polycresyl phosphate, resorcinol-polyxylyl phosphate,
Polyphosphoric acid aryl esters such as hydroquinone-polyphenyl phosphate, hydroquinone-polycresyl phosphate, hydroquinone-polyxylyl phosphate, bisphenol A-polyphenyl phosphate, bisphenol A-polycresyl phosphate, and bisphenol A-polyxylyl phosphate Particularly preferred.

The reason why the phosphate obtained by the production method of the present invention imparts excellent coating adhesion is not clear, but a small amount of P-produced by the reaction between phosphorus oxychloride and water.
It is considered that the phosphoric acid residue represented by O—H acts to increase the affinity with the paint.

[0021]

The present invention will be described below in detail with reference to examples. Cresol used for the reaction was dehydrated by molecular sieve. Water measured by Karl Fischer method is 3p
pm. Bisphenol A and resorcinol used in the reaction were each dried at 120 ° C. and 100 ° C. in a vacuum dryer.
Dry at 24 ° C. for 24 hours. Moisture measured in the same way
They were 2 ppm and 5 ppm, respectively.

[0022]

EXAMPLE 1 114 g of bisphenol A, 157 g of phosphorus oxychloride, 0.1 g of distilled water and anhydrous magnesium chloride 3
g was placed in a 500 ml four-necked flask equipped with a stirrer and a reflux tube, and reacted at 100 to 140 ° C under a nitrogen stream. Hydrogen chloride gas generated during the reaction is collected by water,
The progress of the reaction was monitored based on the amount generated. After completion of the reaction, the flask was evacuated to a pressure of 200 mmHg or less by a vacuum pump while maintaining the reaction temperature, and unreacted phosphorus oxychloride was collected by a trap. Then, the flask was cooled to room temperature, 216 g of cresol was added, and the mixture was heated to 120 to 180 ° C. to react. Hydrogen chloride gas generated during the reaction was collected with water, and the progress of the reaction was monitored based on the generated amount. After completion of the reaction, the flask was evacuated to a pressure of 200 mmHg or less by a vacuum pump while maintaining the reaction temperature, and unreacted phosphorus oxychloride was collected by a trap. Water and 0.1N-N
After washing with an aqueous solution of aOH, a pale yellow transparent compound of the general formula (1)
334 g of the reaction product represented by was obtained.

[0023]

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[0024]

Example 2 Except that the amount of distilled water added was 0.01 g,
In the same manner as in Example 1, a pale yellow transparent reactant 33 was prepared.
2 g were obtained.

[0025]

Example 3 A light yellow transparent reactant 330 was prepared in the same manner as in Example 1 except that the amount of distilled water added was 0.5 g.
g was obtained.

[0026]

Example 4 276 g of a pale yellow transparent reactant represented by the general formula (2) was obtained in the same manner as in Example 1 except that 55 g of resorcinol was used instead of 114 g of bisphenol A.

[0027]

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[0028]

Comparative Example 1 335 g of a pale yellow transparent reaction product was obtained in the same manner as in Example 1 except that distilled water was not added.

[0029]

Comparative Example 2 332 g of a pale yellow transparent reactant was obtained in the same manner as in Example 1 except that the amount of distilled water added was 2 g.

[0030]

Example 5 50 parts by weight of poly 2,6 dimethyl 1,4 phenylene ether resin, 50 parts by weight of impact-resistant polystyrene resin, and 0.1 part by weight of tetrafluoroethylene resin were used in Examples 1 to 4 and Comparative Example 1, respectively. 20 parts by weight of the phosphoric ester obtained in Step 2 were added, and the mixture was melt-kneaded in a nitrogen atmosphere using a twin-screw extruder ZSK-25 (manufactured by W & P) with the cylinder temperature set at 300 ° C. to obtain pellets. Using the pellets, injection molding was performed at 280 ° C. to prepare a 1/16 inch UL combustion test sample piece and a 75 × 75 × 3 mm sample piece.

The coating adhesion was determined by coating a 75 × 75 × 3 mm sample piece with a commercially available urethane paint, and then performing a grid test. The number of peeled grids in 100 grids was determined as follows. Was ranked. ：: No peeling ○: Peeling number 1 to 10 △: Peeling number 11 to 20 ×: Peeling number 21 or more To evaluate the deterioration of the resin during molding, the amount of smoke emitted from the nozzle of the injection molding machine and the coloring of the sample piece are visually observed. Judged. The evaluation of the flame retardant performance was performed according to the vertical combustion method specified in UL-94. The results are shown in Table 1.

[0032]

[Table 1]

[0033]

As is clear from the examples, when producing a phosphate ester from phosphorus oxychloride and monohydric phenols and / or dihydric phenols, 10 to 2000 wtppm of water is added to the total amount of phenols as the raw material. The presence of the compound significantly improves the coating adhesion of a resin composition using the compound as a flame retardant.

Claims (2)

(57) [Claims] 1. A method for producing a phosphoric acid ester by a dehydrochlorination reaction of phosphorus oxychloride and a monohydric phenol and / or a dihydric phenol with respect to the total amount of the raw materials of the monohydric phenol and the dihydric phenol. 10 to 2000
What is claimed is: 1. A method for producing a phosphoric acid ester, characterized in that wt ppm of water is present. 2. The phosphoric acid ester is selected from phosphorus oxychloride, one or more monohydric phenols selected from phenol, cresol, and xylenol, and hydroquinone, resorcinol, and bisphenol A. The method for producing a phosphate according to claim 1, wherein the phosphate is a polyphosphate produced by a dehydrochlorination reaction of a dihydric phenol.