JPS6223009B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing a phosphorus-containing flame retardant. More specifically, the present invention relates to a method for producing a phosphorus-containing flame retardant that exhibits excellent compatibility and thermal stability and imparts high flame retardancy when added to a polymer compound such as polyester or polyamide to produce a molded article. It is known that phosphorus-containing compounds are effective as flame retardants for imparting flame retardancy to linear polymeric materials, particularly polyesters, polyamides, and the like. However, when conventionally known phosphorus-containing compounds are added to linear polymeric materials to produce molded products, they may cause thermal decomposition, imparting undesirable coloration to the molded products, or They have disadvantages such as lowering the degree of polymerization or accelerating crosslinking, resulting in lower mechanical properties of molded articles, and the need to use large amounts in order to impart the desired flame retardancy. Attempts have also been made to improve the thermal stability of phosphorus-containing polymeric compounds as flame retardants, but the effects are still insufficient or the compatibility with polymeric substances is poor. There were some drawbacks, such as dryness. In view of the above circumstances, the present inventors have developed a flame retardant that has good compatibility with linear polymeric substances, especially polyester, is resistant to thermal decomposition even when molded at high temperatures, and can impart excellent flame retardancy. As a result of extensive research into production, we have finally arrived at the novel phosphorus-containing flame retardant shown below. That is, the present invention relates to an unsaturated compound having two carboxyl groups or ester-forming functional groups thereof, and 9,10-dihydro-9-oxa-10phosphorphenanthrene-10-oxide (hereinafter abbreviated as DOP) or its benzene. A phosphorus-containing flame retardant obtained by subjecting a phosphorus compound a represented by the following general formula () obtained by reacting a nuclear substituted product with a diol or an ester-forming derivative thereof to a transesterification reaction or an esterification reaction. This is the manufacturing method. [However, in the formula, R ₁ and R ₂ are the same or different groups, and are a halogen atom or a hydrocarbon group having 1 to 6 carbon atoms that may contain a halogen atom, and p and q are each 0 Represents an integer from ~4. In addition, B is a trivalent alkyl group having 2 to 4 carbon atoms, and R ₃ is a hydrogen atom and 1 carbon atom.
-6 alkyl groups and aryl groups are shown. In addition, when R ₃ is a hydrogen atom, it may be an acid anhydride that forms a ring through a dehydration reaction. ] In the general formula (), B is

【formula】

【formula】

【formula】

Examples include [Formula]. In addition, in the present invention, those without substituents R ₁ and R ₂ on the benzene nucleus, that is, those in which p and q are each o, are preferred in the present invention because they are easily available. used to synthesize phosphorus compound a
DOP or its nuclear substituted product, for example,
As shown in Japanese Patent No. 45397, it is synthesized from 2-hydroxybiphenyl or its nuclear substituted product and phosphorus trichloride. In order to produce the flame retardant of the present invention, it is necessary that the benzene nucleus has no substituent, that is, in the above formula (), p and q are each O.
It is particularly preferred to use one that is (i.e. DOP). Unsaturated compounds as starting materials used to produce phosphorus compound a by reacting with DOP or its benzene-nucleated derivative include dicarboxylic acids such as fumaric acid, maleic acid, mesaconic acid, citraconic acid, glutaconic acid, and itaconic acid. or anhydrides and esters thereof; particularly preferred unsaturated compounds in the present invention include maleic acid, itaconic acid, and anhydrides thereof;
Examples include lower alkyl esters. The method for producing phosphorus compound a by reacting the above DOP or its nuclear substituted product with an unsaturated compound is not particularly limited, but for example, the following method is used.
It can be produced according to the method of reacting DOP and dimethyl itaconate. That is, the target phosphorus compound a can be easily produced by reacting DOP and dimethyl itaconate under heating under reflux in an inert gas atmosphere. The phosphorus-containing flame retardant of the present invention is produced by reacting the phosphorus compound a produced as described above with a diol or an ester-forming derivative. , for example, aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, trimethylene glycol, and tetramethylene glycol, alicyclic glycols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and the following general formula ( ), () and glycols containing aromatic groups. (However, in the formula, X represents a halogen atom, and Y
represents an alkylene group having 1 to 6 carbon atoms, an alkylidene group, a cycloalkylidene group, an aralkylidene group, or a divalent group represented by -O-, -S-, -SO-, or _-SO2- . Further, m ₁ and m ₂ each represent an integer from 0 to 4, and m ₃ represents 0 or 1. ) Carbonic esters of the above-mentioned glycols or ester-forming derivatives of diols such as ethylene oxide and propylene oxide may also be used in the present invention. When producing the flame retardant of the present invention by reacting phosphorus compound a with the diol or its ester-forming derivative, the phosphorus content in the obtained flame retardant is
It is desirable to adjust the amount of each starting material used so that it is 2000 ppm or more, preferably in the range of 5000 to 90000 ppm. This is because if the phosphorus content becomes less than 2000 ppm, the flame retardant performance that can be obtained decreases, which is no longer desirable. On the other hand, if the phosphorus content in the flame retardant becomes too high, a satisfactory result cannot be obtained even by the method described below. The method for producing the flame retardant of the present invention is not particularly limited, except that it is used so that the phosphorus content of the flame retardant from which the phosphorus compound a and the ester-forming compound are obtained falls within the above range. It can be manufactured as described in . That is, in the present invention, phosphorus compound a
When R ₃ is an alkyl group or an aryl group, a flame retardant can be produced by a so-called transesterification reaction using the phosphorus compound a and a diol. Conditions for this transesterification reaction can be substantially similar to those used for producing aromatic polyesters. That is, a metal compound selected from zinc, manganese, titanium, cobalt, and magnesium is used as a catalyst for the transesterification reaction, and the reaction can be heated to reflux at a temperature in the range of about 50 to about 280° C. under normal pressure. On the other hand, when phosphorus compound a is in the form of a free acid or acid anhydride, using a diol,
The flame retardant of the present invention can be produced according to so-called direct esterification when producing aromatic polyester. That is, by using the same metal compound or tin compound as in the case of the above-mentioned transesterification reaction as an esterification catalyst, heating to a temperature range of about 100 to about 280°C under normal pressure or an increased pressure of up to 5 kg/cm ² . The substance can be obtained. In addition, in the case of this method or the above-mentioned transesterification reaction, if the final stage of the reaction is carried out at a slightly higher temperature and reduced pressure, the softening point of the obtained flame retardant will be increased, and therefore the phase of this flame retardant into the polymer compound will be reduced. Since the solubility is improved, it is highly practical and therefore preferred. Flame retardants with a softening point of 30°C are sufficiently practical, but those with a softening point of 70°C or higher are much easier to absorb. The flame retardant of the present invention produced as described above not only has excellent flame retardant properties but also
When a polymer compound, especially a polyester, is added or blended to produce a molded product, it does not thermally decompose or reduce the degree of polymerization of the polyester, so it does not adversely affect the physical properties and color tone of the resulting polyester molded product. Very little to give. Furthermore, the flame retardant obtained by the method of the present invention has extremely good compatibility with polyester, probably because it has a chemical structure similar to the basic skeleton of polyester. Therefore, it can be mixed with polyester and used to produce various molded articles with excellent flame retardancy through simple operations. Note that when polyester is produced using polyester-forming components such as dimethyl terephthalate and ethylene glycol as starting materials, a copolymerized polyester can be produced, but in this method, the phosphorus compound controls the polymerization rate. In addition, the phosphorus compound will undergo a long thermal history. Therefore, it is more practical to mix the flame retardant of the present invention with polyester to produce flame-retardant molded articles because it is easier to produce flame-retardant molded articles with good color tone. The present invention will be explained in more detail below based on Examples, but the present invention is not necessarily limited to these Examples. In the examples, the intrinsic viscosity was measured by dissolving a sample in a mixture of phenol and tetrachloroethane in a 6/4 weight ratio and using an Ubbelohde viscometer at 30°C. Example 1 32.8 parts of a phosphorus compound represented by the following formula () was placed in an autoclave equipped with a pressure and temperature regulator,
Supply 31.0 parts of ethylene glycol and 0.04 parts of potassium titanyl oxalate and heat at 200°C in a nitrogen atmosphere.
The reaction was carried out with stirring in the temperature range of ~220°C for 120 minutes, and then the pressure of the reaction system was gradually reduced to 1 mmHg over 60 minutes. Subsequently, the reaction was carried out for 120 minutes at 220°C and 1 mmHg or less. The product obtained is a yellow solid with a softening point of 75°C and an intrinsic viscosity of
0.21, and the phosphorus content was 8.30%. Example 2 In the same autoclave as used in Example 1, 35.8 parts of 9,10-dihydro-10-(1,2-dicarboxy)ethyl-9-oxa-10 phosphorphenanthrene-10-oxide and ethylene were added. 31.0 parts of glycol and 0.04 parts of potassium titanyl oxalate were supplied and reacted in a nitrogen atmosphere at a temperature range of 160°C to 240°C with stirring for 120 minutes, and then the pressure of the reaction system was gradually reduced to 1 mmHg over 60 minutes. . Subsequently, the reaction was carried out at 240°C and under a pressure of 1 mmHg for 60 minutes. The resulting product is a yellow solid with a softening point of about 30°C, an intrinsic viscosity of 0.18, and a phosphorus content of 8.90%.
It was hot. Example 3 In the same autoclave as used in Example 1,
18.7 g of 10-dihydro-10-(2,3-dimethoxycarbonyl)propyl-9-oxa-10-phosphaphenanthrene-10-oxide, 14.4 parts of 1,4-cyclohexanedimethanol and 0.02 part of titanyl ammonium oxalate. The mixture was allowed to react in a temperature range of 200-250℃ under nitrogen atmosphere for 90 minutes, and then the pressure of the reaction system was gradually reduced to 5 mm in 60 minutes.
It was set as Hg. Continued at 250℃ and 5mmHg pressure for 60 minutes.
Allowed to react for minutes. The product obtained is a yellow solid with a softening point of 78°C, an intrinsic viscosity of 0.19, and a phosphorus content of
It was 6.48%. Example 4 9,10-dihydro- was added to the reactor used in Example 1.
18.7 parts of 10-(1,2-dicarboxy)ethyl-9-oxa-10-phosphaphenanthrene-10-oxide, 9.7 parts of dimethyl terephthalate, 24.8 parts of ethylene glycol, 0.01 part of zinc acetate, and 0.02 parts of potassium titanyl oxalate. The reactor was reacted in a nitrogen atmosphere at a temperature range of 150°C to 240°C with stirring for 200 minutes, and then the pressure of the reaction system was gradually reduced to 1 mmHg over 60 minutes. Continued 240
The reaction was carried out for 100 minutes at a temperature of 1 mmHg or less.
The resulting product was a yellow solid with a softening point of 79°C, an intrinsic viscosity of 0.18, and a phosphorus content of 5.41%. Example 5 In the autoclave used in Example 1, 32.8 parts of a phosphorus compound represented by the formula () and ethylene glycol were added.
12.4 parts of 2,2-bis(3,5-dibromo4-hydroxyphenyl)propane and 0.04 parts of potassium titanyl oxalate were supplied, and the mixture was reacted for 60 minutes in a temperature range of 150°C to 200°C in a nitrogen atmosphere. Then, the pressure of the reaction system was gradually reduced to 1 mmHg for 80 minutes. Subsequently, the reaction was carried out at 210°C and 1 mmHg for 120 minutes. The resulting product is a yellow solid with a softening point of 78°C, an intrinsic viscosity of 0.14, and a phosphorus content of 5.70.
%, and the bromine content was 17.63%. Reference Example 1 A mixture of 2500 parts of dimethyl terephthalate, 1600 parts of ethylene glycol, 0.04% by weight of zinc acetate and 0.05% by weight of antimony trioxide relative to dimethyl terephthalate was transesterified at 150°C to 230°C for 120 minutes. . Subsequently, the temperature of the reaction system was gradually raised and at the same time the pressure was gradually reduced, and finally, after 100 minutes, the temperature was reduced to 275°C and 0.09 mmHg, and polymerization was carried out over a further 30 minutes. The intrinsic viscosity of the obtained polymer was 0.62, and the b value measured using a color difference meter 101D manufactured by Nippon Denshoku Industries was 3.0. The flame retardant obtained in Example 3 was pulverized into granules and mixed into the pellets in a blender to a concentration of 6.2% by weight, and the pellets were spun at a spinning speed of 600 m/min using a melt spinning device at a spinning temperature of 285°C according to a conventional method. Spun at min. The obtained filament has an intrinsic viscosity of 0.55 and a phosphorus content of
It was 0.4%. This filament was stretched 4.6 times on a hot plate at 90°C, and the resulting stretched yarn was knitted into knitted yarn, and the b value was measured in the same manner and found to be 4.5. In addition, this flame retardant property is defined in Article 4-3 of the Fire Service Act Enforcement Order.
- When measured according to the flame retardant performance standards (coil method) specified in Section 4, the average number of times of flame contact (measured 5 times) was 5.0 times. Reference example 2 2500 parts dimethyl terephthalate, 1600 parts ethylene glycol, 122 parts 9,10-dihydro-10
-(2,3-dimethoxycarbonyl)propyl-
A mixture of 9-oxa-10-phosphaphenanthrene-10 oxide, dimethyl terephthalate, 0.04% by weight of zinc acetate, and 0.05% by weight of antimony trioxide was transesterified at 150 to 230°C for 140 minutes. Next, the temperature of the reaction system is gradually increased and at the same time the pressure is gradually reduced, and finally
After 100 minutes, the temperature was set to 275°C and 0.09 mmHg, and polymerization was continued for a further 67 minutes. The obtained polymer had an intrinsic viscosity of 0.60 and a b value of 6.1. This pellet was spun and drawn in the same manner as in Example 7 to obtain a filament. The filament had an intrinsic viscosity of 0.56 and a phosphorus content of 0.4%. Furthermore, the b value of the stockinette knitted material was 6.7. The flame retardancy (coil method) of this product was 5.1 times.

Claims (1)

[Scope of Claims] 1. An unsaturated compound having two carboxyl groups or their ester-forming functional groups and 9,10-dihydro-9-oxa-10 phosphenanthrene-10
-Produced by transesterification or esterification of a phosphorus compound a represented by the following general formula () obtained by reacting an oxide or its benzene-nucleated derivative with a diol or an ester-forming derivative thereof. A method for producing phosphorus-containing flame retardants. [However, in the formula, R ₁ and R ₂ are the same or different groups, and are a halogen atom or a hydrocarbon group having 1 to 6 carbon atoms that may contain a halogen atom, and p and q are each 0 Represents an integer from ~4. In addition, B is a trivalent alkyl group having 2 to 4 carbon atoms, and R ₃ is a hydrogen atom and 1 carbon atom.
-6 alkyl groups and aryl groups are shown. In addition, when R ₃ is a hydrogen atom, it may be an acid anhydride that forms a ring through a dehydration reaction. ]