JPS596318B2 - Method for producing organophosphorus compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing organophosphorus-containing condensation products.

The present inventors first prepared the formula 1a or Ib (wherein, X is a residue, x is an integer of 1 to 6, y is an integer of 1 to 4, and R1. , carbon number 1-8
It has been found that organophosphorus compounds represented by the general formula A (indicating an alkyl, aralkyl, cyclohexyl or phenyl group) are useful flame retardants, and
Patent Application No. 1972-1 discloses a process for producing the target compound of general formula 1a or Ib, which comprises dehydrating and condensing the organophosphorus compound (3 as described above) with melamine or benzoguanamine.
No. 78874.

However, according to this production method, the oxidation product of the general formula A of the starting material (i.e., the same as the oxidation product of the general formula described later) is produced as a by-product in an amount of about 10% of the target compound. Difficulty in separation limits its use.

Furthermore, at the end of the heating condensation reaction, there is a risk of rapidly generating gas, foaming, and blowing up the highly viscous reaction product, so it is necessary to reduce the amount charged per reaction vessel in advance or stop the reaction frequently to avoid this danger. There is a need. Further, a considerable amount of hydrogen and other combustible gases are generated simultaneously with the oxidation product of general formula (A), which may cause a fire or explosion. The present invention reduces the amount of by-products produced,
It facilitates the heating condensation reaction and reduces the risks in industrial production.

It is an object of the present invention to provide a method for producing general formula 1a or Ib. The present invention provides an alkoxymethylmelamine or alkoxymethylbenzoguanamine, that is, an alkoxymethylated aminotriazine, and a general formula () (wherein R1, R2, and R3 are each hydrogen, carbon atom, an alkyl group having 1 to 8 carbon atoms, or an aralkyl group). group, cyclohexyl group or phenyl group.

) is characterized by thermal condensation with a compound represented by the general formula (1) {In formula (1), A is a phenyl group or a -N group, and when A is a phenyl group, 1 is 1~
An integer of 4, m is 4, and when A is -N (group), 1 is an integer of 1 to 6, m is 6.

}Also, X is the general formula (), {In the general formula (), R1, R2 and R3 are each hydrogen,
Halogen, alkyl group having 1 to 8 carbon atoms, aralkyl group,
Indicates a cyclohexyl group or a phenyl group.

} The present invention relates to a method for producing an organophosphorus compound represented by .

According to the production method of the present invention, the amount of the oxidation product of the general formula as a by-product is 2% or less, and the target compound can be obtained more purly, which has the advantage of expanding the range of applications without the need for difficult separation of by-products. There is. Furthermore, the reaction proceeds smoothly in the final stage of the reaction, improving productivity. Furthermore, the generation of flammable gas is extremely low, and the risk of fire or explosion is almost eliminated. In the present invention, alkoxymethylmelamine and alkoxymethylbenzoguanamine refer to NH of melamine or benzoguanamine.
At least one hydrogen atom of the group is replaced by one R4OCH2 group (
In the formula, R4 represents lower alkyl).

Alkoxymethylbenzoguanamine or alkoxymethylmelamine is generally known as one of the amino resins,
It is especially widely used in paint applications.

Structurally, benzoguanamine can be 1 to 4 alexoxymethylated, and melamine can be 1 to 6 alkoxymethylated, and literature reports that each has been isolated on a laboratory scale. The alkoxymethyl melamine or alkoxymethyl benzoguanamine used in the present invention has a content of free methylol groups and dimethylene ether groups. Less is preferred, with 1 to 6 preferably 2.0 to 3.0 alkoxymethyl substitutions for melamine and 1 to 4 preferably 1.0 to 2.0 for benzoguanamine.
Alkoxymethyl-substituted derivatives of are suitable.

However, alkoxymethylmelamine or alkoxymethylbenzoguanamine may contain bonding groups such as -NH-CH2-NH- and -N(CH2OR4)2 in addition to the -NHCH2OR4 group, and the condensation reaction of the present invention may include bonding groups such as -NH-CH2-NH- and -N(CH2OR4)2. It has been confirmed by the following experimental facts that the target compound of the present invention can be obtained almost unaffected by the presence of the bonding group. The condensation reaction between alkoxymethylmelamine and alkoxymethylbenzoguanamine with the general formula () is mainly represented by the empirical formula (), and is either a dealcoholization reaction or actually corresponds to a more complex composition of alkoxymethylmelamine and alkoxymethylbenzoguanamine. It was found based on the following empirical formula (V) and empirical formula () that the desired product of the present invention is produced through a more complicated reaction process.

As can be easily understood from their structures, the products according to the empirical formula (), the empirical formula (V), and the empirical formula () have a strong intramolecular hydrogen bond between the oxygen of the p=o bond and the hydrogen of the N-H bond. In fact, infrared absorption based on the stretching vibration of hydrogen-bonded N-H is observed as a broad peak at wave number 3350.

This ensures that the product of the process according to the invention has the general formula 1a
Or, it is confirmed that it has the structure Ib. To obtain alkoxymethylmelamines and alkoxymethylbenzogs suitable for the purposes of the present invention, it is known that melamine or benzoguanamine is methylolated with formalin or paraform as a source of formaldehyde in the presence of an alkaline catalyst, followed by acidic conditions. to perform dehydration condensation with alcohol. As the alcohol, lower alcohols such as methanol, ethanol, isopropanol, butanol, secondary butanol or isobutanol are used. In order to prevent gelation due to multimerization due to the methylene bond of the triazine ring, it is preferable to use the alcohol in a large excess of the theoretical amount. If the methylolated product of melamine or benzoguanamine remains unetherified with alcohol, water will be produced during the condensation reaction with the compound of the general formula (
) gives an oxidation product of the compound of general formula (), so the N-methylolated product either completes the reaction with a very large amount of alcohol or the water produced by the etherification reaction is removed from the system. It is preferable to complete the reaction by removing the compound and shifting the X equilibrium. When the reaction is to be completed by the former method, methanol with the smallest molecular weight is preferred, and when the reaction is to be completed by the latter method, butanol, secondary butanol, or isobutanol is preferred because water can be easily removed by azeotropy. Appropriate. Separation of water from the azeotrope becomes more effective if benzene, toluene, or xylene is added. Alkoxymethylmelamine or alkoxymethylbenzoguanamine can be reacted according to the two general formulas () even if they contain a catalyst or alcohol. The compound of the general formula () is known, and
45397 and Japanese Patent Publication No. 50-17979, or a method similar thereto.

As a specific example of the general formula (), 9,10-dihythro9
-Oxa-10-phosphaphenanthrene-10-oxide (hereinafter abbreviated as HCA), 6,8-dichloro-
9,10-dihythro9-oxa-10-phosphaphenanthrene-10-oxide, 6-methyl-9,10
-dihythro9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tritertyabutyl-9,10-dihythro9-oxa-10-phosphaphenanthrene-10-oxide, 6- Examples include phenyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-110-oxide or 6,8-dibenzyl-9,10-dihythro-9-oxa-10-phosphaphenanthrene-110-oxide. It will be done.

The reaction of the present invention uses both alkoxymethyl melamine and alkoxymethyl benzoguanamine as the general formula ()
It may be condensed with a compound of

The condensation reaction of the present invention is carried out by heating, but a catalyst may be added to the reaction system if desired to shorten the reaction time. Heating is preferably carried out at a temperature of up to 250°C, and preferably adjusted to a temperature of up to 220°C to prevent coloring of the reaction product. In order to completely remove volatile components from the target product resulting from the condensation reaction, the reaction system can be reduced in pressure or an inert gas can be blown into the reaction system to promote distillation of the volatile components. The time required for the condensation reaction is controlled by the desired conversion rate, temperature, and the presence or absence of a catalyst, but in reality it is possible to adjust these requirements to keep the reaction time within 1 to 10 hours. is preferable. As a catalyst for condensation reaction,
General metal compounds that are effective for dehydration condensation can be used, and specific examples include sodium hydroxide,
Sodium carbonate, sodium acetate, potassium hydroxide, potassium carbonate, potassium acetate, calcium hydroxide, calcium oxide, barium hydroxide, zinc hydroxide, zinc oxide, zinc acetate, zinc chloride, cadmium chloride, aluminum chloride, germanium oxide, chloride Examples include tin or lead acetate. The progress of the condensation reaction can be followed by liquid chromatography to determine the end point of the reaction.

The product is a colorless or light yellow transparent glassy solid with a softening point of 100℃ to 180℃, and can be mixed with AS resin, ABS resin, polystyrene, polycarbonate, polyester, polyamide, phenoxy resin, etc. It can provide heat-resistant and heat-retardant plastics.

Its blending amount is 1 to 2 parts by weight per 10'0 parts by weight of plastic.
It is 0 parts by weight. Next, specific examples will be given and explained.

Example 1 A four-bottle flask with an internal volume of 2000 ml was equipped with a stirrer, a thermometer, a gas inlet, a packed column rectifier with a diameter of 3 cm and a filling height of 40 cm, and a dehydration device with a reflux condenser. 561 grams (3.0 moles) of benzoguanamine, 80 percent paraform 225
(3.0 x 2 moles) and 962 grams of butanol (3.0 x 5 moles, 1 mole), stir while gently blowing nitrogen gas, and bring the temperature of the contents to 800 g.
Make it.

When 2 milliliters of a 10% aqueous sodium carbonate solution is added to make the reaction system alkaline, the addition of formaldehyde to benzoguanamine occurs and the inside of the flask becomes transparent after about 1 hour. After keeping this temperature for another hour, add 0.5 ml of formic acid and keep at this temperature for another hour. Then, gently pour benzene into the reaction system from the top of the dehydrator so that 100 milliliters of benzene is added to the reaction system. Subsequently, the flask is further heated to boil the contents of the flask to such an extent that the packed column does not flood, and water is removed by an azeotropic method. After about 20 hours, the theoretical amount of water has been removed and water distillation stops. This
Remove benzene and butanol from the water outlet of the dehydrator and bring the temperature of the contents to 120°C. This is cooled and a small amount of undissolved material is removed to obtain dibutoxymethylbenzoguanamine. Separately, HCAl2 was placed in a four-bottle flask with an internal volume of 2000 ml, equipped with a stirrer, a thermometer, a dropping load, and a vacuum distillation device with a rectifier column with a diameter of 4 cm and a filling height of 20 cm.
Charge 96 grams (3.0 x 2 moles). After bringing the temperature of the contents to 130°C, begin stirring and create a vacuum of 30 mm of mercury inside the flask. In this state, the entire amount of dibutoxymethylbenzoguanamine mentioned above is dripped from the dripping load. The dropping rate is kept at a level that allows a slight reflux from the top of the rectification column and does not cause the rectification column to flatten. During this time, heating is continued to keep the contents of the flask at 130°C. After the dropwise addition is completed, the inside of the flask is evacuated to about 5 mm of mercury and the temperature is gradually raised to bring the temperature of the contents to 200°C. The reaction is completed approximately 6 hours after the temperature reaches 200°C, so at this temperature the reactants are poured into a stainless steel vat and cooled.

The end point of the reaction is determined by confirming the disappearance of HCA by liquid chromatography. The product is a pale yellow transparent glassy solid with a softening point of 125°C to 125°C by capillary method.
The temperature is 142°C. According to infrared absorption spectrum analysis, two sharp absorptions, one due to the stretching vibration of P-H of the starting material at a wave number of 2370 and the other due to the stretching vibration of N-H near the wave number 3400, disappeared, indicating that N- due to intramolecular hydrogen bonding. One weak absorption is observed at wave number 3350 due to the proton based on the stretching vibration of H. The main product was isolated by column chromatography on silica gel, and elemental analysis showed 9.61% phosphorus (9.64% theoretical) and 11.0% nitrogen (10.89% theoretical).
, carbon 16.80% (theoretical value 16.80%) and hydrogen 4.09% (theoretical value 4.20%), and the molecular weight measurement result by the boiling point elevation method showed 625. From these data, It is determined that the main product is of structural formula (). It was confirmed that 82% of the structure had the structural formula (). Example 2 561 grams of benzoguanamine (
3.0 mono, 124 grams of 80 percent paraform (3.0 x 1.1 mono and 962 grams of butanol)
Butoxymethylbenzoguanamine is obtained from 3.0×5 mol).

Furthermore, in the same flask as in Example 1, 3 grams of HCA7l (3
．． In the same manner as in Example 1, the entire amount of butoxymethylbenzoguanamine was added dropwise at 130°C. After dropping, the inside of the flask is evacuated to about 5 mm of mercury and the temperature of the contents is raised to 210°C. After 2 hours at this temperature, the reactants are discharged into a stainless steel vat and cooled. The product is a pale yellow transparent glassy solid with a capillary softening point of 115°C to 1
Indicates 32°C. According to liquid phase chromatography, which detects ultraviolet absorption at 254 molymicrons, the product has the structural formula (), that is, about 39% benzoguanamine disubstituted product, about 17% benzoguanamine, and the largest peak is 42%. The area ratio is shown.

A single compound corresponding to this largest peak was fractionated by thin layer chromatography, and the ratio of nitrogen to phosphorous was determined to be an atomic ratio of 5:1. From this, it is clear that the main product of this example is a compound in the general formula (1) where A = phenyl group, m = 4, and 1 = 1, and R1, R2, and R3 each correspond to hydrogen. It is. Example 3 A four-lobe flask with an internal volume of 2000 ml, equipped with a stirrer, a thermometer, a gas inlet, a packed column rectifier with a diameter of 3 cm and a filling height of 40 cm, and a dehydrator with a reflux condenser. 252 grams of melamine,
Add 515 g (2.0 x 3 moles) of 35% formalin and 2 ml of 10% aqueous sodium carbonate solution, stir slowly while blowing nitrogen gas, and raise the temperature to 65°C.

After about 30 minutes the flask contents become clear. When the liquid becomes clear, add a little butanol until the liquid becomes opaque.
Drip. Once it becomes transparent, add butanol dropwise, and after an hour, add 962
Add butanol to make 2.0 x 7.5 mono and heat the flask to azeotrope the butanol and water, removing about 300 grams of water. This will remove 0.5 ml from the top of the rectification column. 100 from the top of the formic acid and reflux condenser
Add milliliters of benzene. If the mixture is further removed in water for 15 hours while azeotropically distilling, almost no water will be distilled out, so benzene and butanol are expelled until the temperature of the contents reaches 118°C. After cooling, a small amount of undissolved matter is filtered off to obtain tributoxymethylmelamine. 296 g (2.0 x 3 mol) of HCAl was added to a 2000 ml four-loaf flask with an internal volume of 2000 ml, which was equipped with a separate stirrer, a thermometer, a dropping load, and a vacuum distillation apparatus with a rectification column 4 cm in diameter and 20 cm in height. After preparation, the temperature was raised to 140℃, and the inside of the flask was reduced to 17 columns of mercury.
Apply a millimeter vacuum, stir, and add the entire amount of the above tributoxymethylmelamine dropwise in the same manner as in Example 1. The temperature is gradually increased and the heating is adjusted so that the temperature inside the flask is exactly 190° C. at the end of the dropwise addition. After the dropwise addition was completed, the temperature was further increased until the content reached 215°C, and the reaction was completed in 1.5 hours. At this temperature, the contents are poured into a stainless steel vat and cooled. The product is a colorless and transparent glassy solid with a capillary softening point of 145°C to 1.
It shows 63°C. In the infrared absorption spectrum, as in Examples 1 and 2, a weak absorption at a wave number of 3350 is observed due to the N-H plod having intramolecular hydrogen bonds. The main product was isolated by column chromatography in the same manner as in Example 1, and subjected to elemental analysis and molecular weight measurement, and as a result it was confirmed to have the structural formula ().

Molecular weight 852, phosphorus content 11.25%, nitrogen content 9.9
It is 8%. Example 4 374 grams (2.0 moles) of benzoguanamine and 127 grams (2.0 x 2 mole), methanol 1280 grams (2
60 x 2.0 mol) and 0.1 g of sodium hydroxide are charged and stirred while slowly blowing in nitrogen gas to bring the temperature of the contents to 60°C. Eventually, the contents of the flask become transparent.

One hour after the mixture becomes transparent, add 1 ml of formic acid and heat for another 10 hours until the contents gently reflux. After cooling, remove any undissolved matter to obtain dimethoxymethylbenzoguanamine. 2000 internal volume with separate stirrer, thermometer, drip load and vacuum distillation port with dry ice cold trap
6,8-dichloro-9 in a milliliter four-loaf flask
・1140 grams of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (2.0X2
After charging the contents to a temperature of 170°C, the inside of the flask is evacuated to about 3 mm of mercury. At this temperature, the entire amount of dimethoxymethylbenzoguanamine is slowly added dropwise. Upon mixing, volatile components are almost completely removed from the reaction system and condensed in a cold trap. After completion of the dropwise addition, the temperature of the reactant was raised to 200°C and maintained at this temperature for 5 hours to complete the reaction. At this temperature, the reactants are poured into a stainless steel vat and cooled to give a pale yellow transparent glassy solid. The softening point determined by the capillary method was 105°C to 126°C, and infrared absorption spectra, liquid phase chromatography, elemental analysis, and molecular weight measurements showed that the main product was a chlorinated product of structural formula (), and the reactant This accounted for 76% of the total. Molecular weight 782,
Cll8.5%, P795%, N9. O%o Example 5 296 grams of HCAl (3 A butanol solution of dibutoxymethylmelamine (3.0 moles of melamine and formaldehyde components) was prepared in the same manner as in Example 3. 3.0 x 2 mol) is added.

After the addition, the temperature was gradually raised to 200° C., and then the inside of the flask was evacuated to 5 mm of mercury to continue heating. After 6 hours, the contents were poured into a stainless steel vat and cooled. The product is an almost colorless and transparent glassy solid,
The softening point measured by the capillary method was 135°C to 150°C. When this was analyzed by liquid phase chromatography, it was found that the trisubstituted phosphorus compound (i.e., structural formula) for melamine was approximately 3
5 percent, about 40 percent di-substituted and about 17 percent mono-substituted. Example 6 In the same manner as in Example 1, 8-phenyl-9,10-dihythro-9-oxa-10-phosphaphenanthrene-1
1168 grams (2.0 x 2 moles) of O-oxide and 2 moles of dibuhyxymethylbenzoguanamine were combined in 18 columns of mercury.
Millimeter, ^0t-0t- -Airt:k-β"
After a long time, a 1f lees Δ↓I wide ^^ glassy solid is obtained.

The product has a softening point of 145 to 160°C, and liquid phase chromatography and elemental analysis show that in the general formula (), A is a phenyl group, R1 is a phenyl group, R2 and R3 are hydrogen, and m is 4, 1
It was confirmed that the main component is a compound with 2. Molecular weight 800, P, 7.80%, N, 8.8% o Experimental example 1
Experimental examples proving that the compound according to the present invention has a remarkable flame retardant effect when added to a synthetic resin will be described below.

Flame retardancy was evaluated by measuring the burning time of the test piece according to the method of Subject 94 (hereinafter abbreviated as UL-94) of the Underwriters Laboratory standard. The size of the test piece is 3.2 m thick, 12.2 m wide, and 152 m long.
A 4 mm one was used. (1) Test piece A-1; polyethylene terephthalate resin 10 with a number average molecular weight of 27,000
5 parts by weight of the organic phosphorus compound obtained in Example 1 were added to 0 parts by weight, and the mixture was thoroughly kneaded for 10 minutes in a Brabender kept at 280°C, and compression molded at 290°C and 200k9/Cril for 5 minutes.

(2) Test piece A-2: A test piece A-2 was prepared in the same manner as the above test piece A-1 except that the amount of the organic phosphorus compound was changed to 2 parts by weight.

(3) Test piece B-1: Prepared in the same manner as above test piece A-2 except that the organic phosphorus compound obtained in Example 3 was used.

The test results are shown in Table-1.

Experimental example 2 Polycarbonate (bisphenol A) was used as a synthetic resin.
The flame retardancy was evaluated in the same manner as in Experimental Example 1 using 100 parts by weight of V. It received a rating of -1.

Experimental Example 3 Example 3 was added to 100 parts by weight of resol type phenolic resin powder.
Flame retardancy was evaluated in the same manner as in Experimental Example 1 using test pieces to which 4 parts by weight of the organic phosphorus compound obtained in V-
Obtained a rating of 0.

Claims (1)

[Claims] 1. General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) {Formula (III)
Among them, R_1, R_2 and R_3 each represent hydrogen, halogen, an alkyl group having 1 to 8 carbon atoms, an aralkyl group, a cyclohexyl group, or a phenyl group. } General formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) In formula (I), A is a phenyl group or a -N■ group; when A is a phenyl group, l is an integer of 1 to 4; m is 4; when A is a -N■ group, l is an integer of 1 to 6; m is 6. Also, X is general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (general formula (I
In I), R_1, R_2 and R_3 are the same as defined in general formula (III).