JPH05178975A - Production of fire-resistant polyester - Google Patents

Abstract

PURPOSE:To obtain a fire-resistant polyester stably at a low cost by carrying opt a specific reaction step in the presence of both a specific phosphorus compd. and an unsatd. carboxylic acid or its ester-forming deriv. in the process for producing the polyester. CONSTITUTION:A phosphorus compd. of the formula [wherein R1 and R2 are each alkyl, aryl (optionally substd. by alkyl, alkoxy, or halogen), or alkoxy provided that they may be the same or different and that they may combine with each other to form a ring] is added to an unsatd. carboxylic acid or its ester-forming deriv. at an arbitrary step when the intrinsic viscosity of a polyester formed is below 0.5 in the process for preparing a polyester by reacting at least one dicarboxylic acid or its ester-forming deriv. and at least one diol or its ester-forming deriv. and/or at least one hydroxycarboxylic acid or its ester-forming deriv.

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 flame resistant polyester capable of forming molded articles such as fibers, films and boards having excellent flame resistance.

[0002]

2. Description of the Related Art In recent years, from the standpoint of respect for human beings, various molded products such as fibers are required to be flame retardant, and various efforts have been made. In order to impart flame resistance even to molded products manufactured from linear polyester, a method of copolymerizing or blending by adding a flame resistance-imparting substance at the time of polymer production, kneading the flame resistance-imparting substance to polyester at the time of manufacturing a molded product. A method of adding flame resistance by post-processing a molded article made of polyester has been proposed.

Among these methods, considering the industrial value, it is the simplest method and does not impair the various performances of the obtained molded product, so that a flame resistance-imparting substance is added at the time of polymer production to carry out copolymerization. For this purpose, various phosphorus compounds, for example, phosphoric acid esters such as triphenyl phosphate and phosphonic acids such as benzenephosphonic acid derivatives have been conventionally used.

However, when such a compound is used, the catalyst is deactivated during the production of the polyester, the polymerization time is significantly extended, and the melting point of the polymer obtained by forming an ether bond is lowered. It has also been a cause of three-dimensionalization of the polymer. Further, the phosphorus compound may be scattered from the polyester production system, the amount of the phosphorus compound introduced into the polyester may be reduced, and the flame resistance effect of the polyester may be reduced, or the scattered phosphorus compound may cause problems such as environmental pollution. ..

As a method for solving these various problems, the present applicant has previously proposed a method for producing a flame-resistant polyester by copolymerizing a specific phosphorus compound (Japanese Patent Publication No. 55-4).
1610). According to this method, the above-mentioned problems can be solved, but the phosphorus compound used in the method is a special and expensive one, and when a phosphorus atom capable of imparting sufficient flame resistance to the polyester is introduced, it is produced. It has the drawback of being expensive.

As a means for solving such a drawback, there has been proposed a method for producing an inexpensive flame resistant polyester by reacting a polyester which is copolymerized with a specific unsaturated carboxylic acid with a specific phosphorus compound in advance (special feature: (See Japanese Patent Publication No. 3-59087).

[0007]

According to the above method, it is not necessary to separately produce a copolymerizable phosphorus compound.
It is possible to significantly reduce the manufacturing costs of flame resistant polyesters. However, in this method, an active and unstable unsaturated carboxylic acid or an unstable phosphorus compound having a P—H bond is reacted under severe conditions under high temperature, so that a part of the obtained flame resistant polyester is tertiary The original cross-linked structure is formed, and the processing operability for fibers and films decreases,
In addition, problems such as deterioration of physical properties of the obtained fiber or film occur.

Further, since the unsaturated carboxylic acid is copolymerized at a high temperature, the unsaturated bond may be damaged and the reaction with the phosphorus compound may not proceed quantitatively. Furthermore, addition of a phosphorus compound active at high temperature causes problems such as decomposition of the produced polyester.

It is an object of the present invention to provide a stable and inexpensive flame-resistant polyester production method which does not have the above problems.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that when producing a polyester, the unsaturated carboxylic acid or its ester-forming derivative is added at a specific time. The present invention has been completed by finding that a sufficient phosphorus atom capable of imparting flame resistance can be introduced into a polyester by a simple method of allowing a specific phosphorus compound to coexist and react.

That is, the method for producing a flame-resistant polyester of the present invention comprises one or more dicarboxylic acids or their ester-forming derivatives and one or more diols or their ester-forming derivatives and / or one or more oxycarboxylic acids. Alternatively, in the production of a flame resistant polyester from its ester-forming derivative, at any stage where the intrinsic viscosity of the polyester is less than 0.5, the following general formula (I)
The phosphorus compound [hereinafter referred to as phosphorus compound (I)] and the unsaturated carboxylic acid or its ester-forming derivative are allowed to coexist.

[0012]

[Chemical 2]

In the formula, R ₁ and R ₂ are the same or different and each represents an alkyl group, an aryl group (which may be substituted with an alkyl group, an alkoxy group or a halogen atom) or an alkoxy group, and R ₁ , R ₂ may form a ring with each other.

The present invention will be described in more detail below. The phosphorus compound (I) used in the production of the flame-resistant polyester of the present invention has an effect of imparting flame resistance to the polyester, but does not have an ester-forming ability by itself and is inactive to an ester-forming reaction. is there. On the other hand, the unsaturated carboxylic acid coexisting with the phosphorus compound itself does not have a function of imparting flame resistance to the polyester,
It is an indispensable raw material in order to make a phosphorus compound a derivative capable of forming an ester. In other words, the phosphorus compound (I) and the unsaturated carboxylic acid cannot obtain the desired flame-resistant polyester from their own use, but only when both compounds are used in coexistence, practical value can be obtained. It is possible to produce a flame resistant polyester having

The alkyl group for R ₁ and R ₂ may be linear or branched, and may be, for example, methyl, ethyl,
Examples include propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, octyl, decyl, dodecyl and the like having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms.

With respect to R ₁ and R ₂ , the alkoxy group may be linear or branched and has, for example, 1 carbon atom such as methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, pentyloxy and hexyloxy. -10, preferably 1-6 are mentioned. Examples of the aryl group for R ₁ and R ₂ include phenyl, naphthyl, diphenyl and the like. The aryl group may have a substituent, and the substituent is an alkyl group (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl or the like having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms). An alkyl group), an alkoxy group (for example, methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, pentyloxy, hexyloxy, etc., having 1 to 1 carbon atoms)
10, preferably 1 to 6 alkoxy groups) and halogen atoms (eg chlorine, bromine, fluorine, etc.).

The ring formed by R ₁ and R ₂ has the following structure.

[0018]

[Chemical 3]

[0019]

[Chemical 4]

[0020]

[Chemical 5]

Examples of the phosphorus compound (I) include dimethylphosphine oxide, diethylphosphine oxide, dipropylphosphine oxide, dibutylphosphine oxide, diphenylphosphine oxide, methylhydrogenmethylphosphonite, ethylhydrogenmethylphosphonite and methylhydrogen. Methyl phosphonite, ethyl hydrogen ethyl phosphonite, methyl hydrogen propyl phosphonite, ethyl hydrogen propyl phosphonite, methyl hydrogen butyl phosphonite, ethyl hydrogen butyl phosphonite, methyl hydrogen benzene phosphonite, ethyl hydrogen benzene Phosphonite, 9,
Examples thereof include 10-dihydro-9-phospha-10-oxaphenanthrene-9-oxide (hereinafter abbreviated as HCA) and the like. Of these, dimethylphosphine oxide, diethylphosphine oxide, dipropylphosphine oxide and dibutylphosphine oxide are particularly preferable. , Diphenylphosphine oxide and HCA are preferred.

Further, as the unsaturated carboxylic acid or its ester-forming derivative, acrylic acid, methyl acrylate, ethyl acrylate, crotonic acid, methyl crotonic acid, ethyl crotonic acid, methacrylic acid, methyl methacrylate, meta Ethyl acrylate, maleic acid, dimethyl maleate, diethyl maleate, maleic anhydride,
Fumaric acid, dimethyl fumarate, diethyl fumarate, mesaconic acid, dimethyl mesaconate, diethyl mesaconate, citraconic acid, dimethyl citraconic acid, diethyl citraconic acid, citraconic anhydride, itaconic acid, dimethyl itaconate, diethyl itaconate, itaconic anhydride Examples thereof include acids such as acids and ester-forming derivatives thereof, and of these, dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, or ester-forming derivatives thereof are particularly preferable.

In the present invention, it is desirable that the phosphorus compound (I) and the unsaturated carboxylic acid or its ester-forming derivative are used in substantially equimolar amounts, but one of them is in excess of 20 mol%. It does not matter if there is a shortage. However, when the range of excess and deficiency of the phosphorus compound and the unsaturated carboxylic acid exceeds 20 mol%, not only the production of the flame resistant polyester becomes difficult but also the physical properties of the obtained fiber or film are deteriorated. It is not preferable.

The flame-resistant polyester of the present invention has a phosphorus atom content of 500 to 50,000 pp in the polyester in consideration of flame resistance and physical properties of the obtained fibers and films.
m, particularly preferably in the range of 1,000 to 10,000 ppm. If the phosphorus atom content of the flame-resistant polyester is less than 500 ppm, it becomes difficult to impart the desired flame resistance to the polyester, while if it exceeds 50,000 ppm, not only the operability at the time of producing the polyester decreases but also However, the physical properties of the obtained fiber or film are deteriorated, and the manufacturing cost becomes high, which is not preferable.

In the method for producing a flame-resistant polyester of the present invention, since the phosphorus atom is introduced into the polyester, the phosphorus compound (I) and the unsaturated carboxylic acid or the ester-forming derivative thereof are mixed with each other in the intrinsic viscosity in the production process of the polyester. Is required to be added and present at any time of less than 0.5.

In general, polymeric substances tend to have a marked increase in melt viscosity with an increase in the degree of polymerization due to the reaction, and polyesters are no exception. If the phosphorus compound (I) and the unsaturated carboxylic acid are added under such a high viscosity condition, it takes time until they are uniformly mixed, and the reaction becomes non-uniform, and the unstable compound remains for a long time. Since it is exposed to high temperatures, problems such as the decomposition of polyester occur.

Therefore, it is necessary to add the phosphorus compound (I) and the unsaturated carboxylic acid at a time when the viscosity of the reaction system is as low as possible. In the present invention, the intrinsic viscosity of the polyester is less than 0.5, preferably 0. 0.3 or less, more preferably at a known esterification reaction or transesterification reaction time in the polyester production process.

The phosphorus compound (I) and the unsaturated carboxylic acid can be added at any temperature as long as the reaction temperature is applied during the production of polyester. Since phosphorus compounds and unsaturated carboxylic acids that are unstable with respect to temperature are used, decomposition and partial three-dimensionalization of the polyester are induced, which adversely affects the operability during the production and molding of the polyester. It will cause deterioration of the physical properties of the obtained fiber or film.

Therefore, in the present invention, when the phosphorus compound and the unsaturated carboxylic acid are added to the polyester polymerization system, the temperature of the reaction system is usually 260 ° C. or lower, preferably 200 ° C.
Will be done below.

In order to specifically explain the present invention, HCA is selected as the phosphorus compound (I) and itaconic acid is selected as the unsaturated carboxylic acid, and they are coexisted with terephthalic acid and ethylene glycol. A production method of introducing a phosphorus atom into polyethylene terephthalate will be described. The process of forming the flame resistant polyester of the present invention from the above raw materials is as shown in the reaction formula below.

[0031]

[Chemical 6]

As can be understood from this reaction formula, in the production method of the present invention, a reaction for producing an ester-forming phosphorus compound derivative by reacting a phosphorus compound which does not itself have an ester-forming ability with an unsaturated carboxylic acid is used. , A reaction known in the art to form a polyester. The reaction formula shown here is an example in the production of flame-resistant polyester, and a different reaction route may be adopted depending on the production conditions such as the addition timing of HCA and unsaturated carboxylic acid or the order of raw material charging. Even if selected, there is no difference in that the above-mentioned two reactions are basic. Thus, both the phosphorus compound (I) and the unsaturated carboxylic acid are unstable substances by themselves, but when these two compounds react to form a new phosphorus compound derivative, they become very stable thermally, and A good flame resistant polyester can be produced without causing decomposition or side reaction during production.

The reaction of the phosphorus compound (I) with the unsaturated carboxylic acid usually proceeds only by heating, but in order to accelerate the reaction, sodium alcoholate, potassium alicholate, sodium hydroxide, potassium hydroxide or the like is used. It is also possible to use metal salts as catalysts. In short, the method for producing a flame-resistant polyester of the present invention is a conventionally known polyester production process, which does not have an ester forming ability by itself but is essential for imparting flame resistance to the polyester, and the phosphorus compound (I) and the unsaturated compound. By reacting with a carboxylic acid, as a phosphorus compound derivative of ester forming,
It is intended to produce a flame resistant polyester, which is significantly different from the method adopted in the above-mentioned known examples of producing a flame resistant polyester by adding a separately produced flame resistance imparting agent in the polyester production process. in this way,
According to the method of the present invention, it is not necessary to separately manufacture the flame resistance-imparting agent, and it becomes possible to manufacture the flame resistance polyester at such a low cost.

The dicarboxylic acid component used to produce the flame resistant polyester of the present invention includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
1,5-naphthalenedicarboxylic acid, 4,4′-diphenylcarboxylic acid, 5-sodium sulfoisophthalic acid,
Examples thereof include aromatic dicarboxylic acids such as 2,5-dibromoterephthalic acid, aliphatic and alicyclic dicarboxylic acids such as adipic acid, azelaic acid, sepacic acid and hexahydroterephthalic acid, or a mixture thereof.

On the other hand, examples of the diol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, neopentyl glycol and 1,4-cyclohexanedimethanol.

As the oxycarboxylic acid component, 4
-Oxybenzoic acid, 4-hydroxyethoxybenzoic acid,
Examples thereof include oxypivalic acid.

The flame-resistant polyester of the present invention is produced from the above-mentioned dicarboxylic acid component, diol component or oxycarboxylic acid component, phosphorus compound (I) and unsaturated carboxylic acid component. The production of this polyester is carried out, for example, by a transesterification reaction, an esterification reaction, a polycondensation reaction and the like, and the reaction conditions can follow the conventionally known conditions.

When the flame-resistant polyester is produced by the above transesterification reaction, conventionally known metal compounds such as lithium acetate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, zinc acetate, manganese acetate, Cobalt acetate, titanium tetrabutoxide, potassium titanyl oxalate or the like is used as a catalyst, and after transesterification at a temperature of 100 to 240 ° C., a metal compound such as germanium oxide, antimony trioxide or tungstic acid is further added if necessary. 2 as a catalyst under high vacuum of 1 mmHg or less
The target flame resistant polyester can be obtained by polycondensation at a temperature of 40 to 320 ° C.

On the other hand, when a flame resistant polyester is produced through the above esterification reaction, an organic amine compound, an alkali metal salt such as sodium acetate, an alkaline earth metal salt such as calcium acetate, tin acetate, titanium is used as a catalyst. Atmospheric pressure ~ 5kg / in the presence of metal salts such as tetrabutoxide
Under a pressure of cm ² , an esterification reaction is performed at a temperature of 200 to 280 ° C. to obtain a predetermined reaction product, and then polycondensation is performed according to the method described in the above transesterification method to obtain a desired flame-resistant polyester. Obtainable.

In the method for producing a flame-resistant polyester of the present invention, additives usually used in the production of polyester, for example, pigments such as titanium oxide and carbon black, stabilizers such as thermal decomposition and ultraviolet absorbers, and A plasticizer or the like can be used.

[0041]

As described in detail above, according to the method of the present invention, a special phosphorus compound is not required and a simple method of reacting the polyester in the presence of the phosphorus compound and the unsaturated carboxylic acid during polyester production A phosphorus atom can be introduced into the resin to obtain a flame resistant polyester having stable physical properties.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following examples. In the examples, the intrinsic viscosity is phenol / 1,
1,2,2-tetrachloroethane mixed solvent (weight ratio 3:
It is a value obtained by measuring at 30 ° C. in 2). In the flame resistance test, a yarn obtained by spinning and drawing a polyester polymer by an ordinary method is used as a knitting knit, and 1 g of the yarn has a length of 10
Round it into cm and insert it into a wire coil with a diameter of 10 mm,
The sample was held at an angle of °, ignited from the lower end, and when the fire source was moved away to extinguish the fire, the ignition was repeated again, and the number of ignitions required to burn all samples was obtained. In the evaluation of the flame resistance test, the number of ignitions of five samples is represented by an average value, and the larger the value, the better the flame resistance.

Example 1 1203 g of terephthalic acid, 1030 ethylene glycol
g, HCA 62.8 g, itaconic acid 39.7 g and triethylamine 3.8 g were heated in an autoclave under a pressure of 2.51 g / cm ² at 238 ° C. for 2 hours to carry out an esterification reaction. Subsequently, 0.88 g of antimony trioxide was added as a catalyst, and the system temperature was adjusted to 2 in 70 minutes.
The temperature was raised to 75 ° C., and the system pressure was gradually reduced to 0.15 mmHg during this period, and polycondensation was carried out for 3 hours under these conditions. The polymer obtained has an intrinsic viscosity of 0.63 and a melting point of 250.
C., the phosphorus atom residual rate was 97.6%. The flame resistance was 5.2 times.

Example 2 Polymerization was carried out for 2 hours in the same manner as in Example 1 except that 0.63 g of germanium dioxide was used instead of the antimony trioxide used in Example 1. The polymer obtained has an intrinsic viscosity of 0.64, a melting point of 251 ° C., and a phosphorus atom residual ratio of 98.7.
%Met. Moreover, the number of times of flame resistance was 5.1 times.

Example 3 1219 g of terephthalic acid, 1030 of ethylene glycol
g, itaconic acid 33.1 g and triethylamine 3.
2.5 kg / cm ^{2 of a} mixture consisting of 8 g in an autoclave
After heating at 235 to 241 ° C. for 2 hours under esterification, the system pressure is returned to normal pressure, and HCA is 52.4 g.
Was added to the reaction system and reacted at 235 ° C. for 1 hour, 0.40 g of germanium dioxide was added, and polymerization was carried out for 115 minutes in the same manner as in Example 1. The intrinsic viscosity when HCA was added was 0.08. The polymer obtained has an intrinsic viscosity of 0.6.
The melting point was 0, the melting point was 253 ° C., and the phosphorus atom residual ratio was 98.6%. In addition, the number of times of flame resistance was 4.8 times.

Example 4 1219 g of terephthalic acid, 1030 of ethylene glycol
g, HCA 52.4 g, itaconic acid 33.1 g and triethylamine 3.8 g in an autoclave under pressure of 2.5 kg / cm ² and heated at 194 ° C. for 3 hours, then heated to 235 ° C. and heated to the same temperature. The esterification was carried out by heating for 2 hours. 0.55 g of antimony trioxide was added and polymerization was carried out for 150 minutes in the same manner as in Example 1. The obtained polymer had an intrinsic viscosity of 0.61, a melting point of 254 ° C., and a phosphorus atom residual ratio of 98.9%. In addition, the number of times of flame resistance was 4.9 times.

Example 5 A mixture of 1030 g of ethylene glycol, 41.9 g of HCA and 25.2 g of itaconic acid was heated to 196 ° C. in an autoclave for 1 hour under a nitrogen stream. Thereafter, the same temperature was maintained for 1 hour. Then terephthalic acid 1
234 g and triethylamine 3.8 g were added, 2.
The temperature of the reaction system was raised to 235 ° C. under a pressure of 5 kg / cm ² , and esterification was carried out at the same temperature for 2 hours. Then, 0.56 g of antimony trioxide was added, and 1 was added in the same manner as in Example 1.
Polymerization was carried out for 00 minutes. The obtained polymer had an intrinsic viscosity of 0.
The melting point was 60, the melting point was 256 ° C., and the phosphorus atom residual ratio was 99.4%. In addition, the number of times of flame resistance was 4.8 times.

Example 6 1203 g of terephthalic acid, 1030 ethylene glycol
g of triethylamine and 3.8 g of triethylamine in an autoclave under a pressure of 2.5 kg / cm ² at 240 ° C. for 2 hours.
After the esterification for a period of time, the reaction system was returned to normal pressure, 62.8 g of HCA and 41.6 g of itaconic acid were added under a nitrogen stream, and the reaction was carried out at 240 ° C. for 1 hour. The intrinsic viscosity when HCA and itaconic acid were added was 0.09. Then, 0.47 g of germanium dioxide was added and polymerization was carried out for 160 minutes in the same manner as in Example 1. The polymer obtained has an intrinsic viscosity of 0.59, a melting point of 251 ° C., and a phosphorus atom residual ratio of 98.1%.
Met. Moreover, the number of times of flame resistance was 5.0 times.

Comparative Example 1 1297 g of terephthalic acid, ethylene glycol 1065
g, HCA 62.8 g and triethylamine 3.9 g
The mixture consisting of was subjected to esterification at 236 ° C. for 2 hours in an autoclave under a pressure of 2.5 kg / cm ² . Next, 0.55 g of antimony trioxide was added, and polymerization was carried out in the same manner as in Example 1 for 3 hours. The obtained polymer had an intrinsic viscosity as low as 0.16 and could not be subjected to molding processing such as spinning or film formation.

Comparative Example 2 1290 g terephthalic acid, 1030 ethylene glycol
g, itaconic acid 37.8 g and triethylamine 3.
Esterification and polycondensation were performed on the mixture of 8 g in the same manner as in Example 1. The polymer obtained after a polycondensation time of 45 minutes had an intrinsic viscosity as low as 0.59 and had a flame resistance of 1.3 times and no flame resistance.

Comparative Example 3 1203 g of terephthalic acid, 1030 ethylene glycol
A mixture of g and 3.8 g of triethylamine was esterified in the same manner as in Example 1. Then, 0.55 g of antimony trioxide was added, polycondensation was carried out in the same manner as in Example 4, and when the intrinsic viscosity of the polymer reached 0.58, the pressure in the system was returned to normal pressure with nitrogen gas, 62.8 g of HCA and itacon. After adding 38.5 g of acid and reacting at 275 ° C. for 1 hour, the reaction system was evacuated to 0.15 mmHg to carry out polymerization for 2 hours. The polymer obtained has an intrinsic viscosity of 0.59 and HCA.
There was almost no increase in viscosity after the addition of itaconic acid. The obtained polymer was colored black and was very dirty, and the residual rate of phosphorus atoms was as low as 81%.

Example 7 1207 g of terephthalic acid and 1030 of ethylene glycol
g, 58.8 g of diphenylphosphine oxide (hereinafter abbreviated as DPPO), 37.8 g of itaconic acid and 13.8 g of triethylamine were subjected to esterification at 233 ° C. for 3 hours in an autoclave under a pressure of 2.5 kg / cm ^2. It was Then add 0.55 g of antimony trioxide to 70
The temperature of the system was raised to 275 ° C. over a period of time, during which the system pressure was gradually reduced to a vacuum degree of 0.1 mmHg. Polycondensation was performed for 145 minutes under these conditions. The obtained polymer had an intrinsic viscosity of 0.60, a melting point of 250 ° C., and a phosphorus atom residual ratio of 97.8%. Moreover, the number of times of flame resistance was 5.2 times.

Example 8 1222 g of terephthalic acid, 1030 ethylene glycol
g, 50 g of DPPO, 33.1 g of itaconic acid and 3.8 g of triethylamine were kept in an autoclave under pressure of 2.5 kg / cm ² at 196 ° C. for 3 hours, and then the temperature of the reaction system was raised to 238 ° C. The esterification was carried out at the same temperature for 2 hours. Then germanium dioxide 0.
47 g was added and polycondensation was carried out for 2.5 hours in the same manner as in Example 1. The polymer obtained has an intrinsic viscosity of 0.63 and a melting point of 2.
The phosphorus atom residual ratio was 53% at 98%. Moreover, the number of times of flame resistance was 4.9 times.

Example 9 1237 g of terephthalic acid and 1030 of ethylene glycol
and 3.9 g of triethylamine were esterified in an autoclave under a pressure of 2.5 kg / cm ² at 238 ° C. for 2 hours. Then, the pressure of the reaction system was set to normal pressure, 39.2 g of DPPO and 27.7 g of itaconic acid were added, and the mixture was reacted for 1 hour under a nitrogen atmosphere. The intrinsic viscosity was 0.08 when DPPO and itaconic acid were added. Subsequently, 0.5 g of germanium dioxide was added, and polycondensation was carried out for 2 hours in the same manner as in Example 1. The polymer obtained has an intrinsic viscosity of 0.63, a melting point of 255 ° C., and a phosphorus atom residual ratio of 98.5.
% The number of times of flame resistance was 4.8 times.

Example 10 A mixture of 58.8 g of DPPO, 39.7 g of itaconic acid and 1030 g of ethylene glycol was kept at 195 ° C. for 3 hours, and subsequently 1207 g of terephthalic acid and 3.8 g of triethylamine were added to the reaction system to give 2.5 kg / cm ²
The pressure is increased to 241 ° C. The same temperature was maintained for 2 hours for esterification. Then antimony trioxide 0.
After adding 55 g, polycondensation was carried out for 115 minutes in the same manner as in Example 1. The polymer obtained has an intrinsic viscosity of 0.60 and a melting point of 25.
The residual rate of phosphorus atoms was 99% at 0 ° C., and the number of times of flame resistance was 5.3 times.

Comparative Example 4 1254 g of terephthalic acid, 1030 ethylene glycol
g, DPPO 58.7 g and triethylamine 4.0
Esterification was carried out by reacting the mixture consisting of g in an autoclave under a pressure of 2.5 kg / cm ² at 239 ° C. for 2 hours. Then, 0.70 g of antimony trioxide was added to Example 1
Polycondensation was carried out for 3 hours in the same manner as in. The obtained polymer had an intrinsic viscosity of 0.18 and could not be molded into fibers or films at all.

Comparative Example 5 1297 g of terephthalic acid, ethylene glycol 1065
g and 3.8 g of triethylamine were added, esterification was carried out in the same manner as in Example 1, and polycondensation was carried out for 92 minutes. The polymer obtained has an intrinsic viscosity of 0.65 and a melting point of 2
It was 59 ° C. The flame resistance was 1.2 times, which was very low.

Example 11 1253 g of terephthalic acid, ethylene glycol 1055
g, diethylphosphine oxide (hereinafter abbreviated as DEPO) 20.5 g, itaconic acid 25.9 g and triethylamine 3.8 g were esterified in the same manner as in Example 8, and 0.63 g of germanium dioxide was added. Polycondensation was carried out in the same manner as in No. 8 for 115 minutes.
The polymer obtained has an intrinsic viscosity of 0.62 and a melting point of 253.
It was ℃. The phosphorus atom residual rate was 96.7%. The flame resistance was 4.8 times.

Example 12 A mixture of 25.7 g DEPO, 33.1 g itaconic acid and 1053 g ethylene glycol was kept at 194 ° C. for 3 hours, followed by the addition of 1242 g terephthalic acid and 3.8 g triethylamine at 2.5 kg / cm ² . Esterification was performed under pressure at 243 ° C. for 2 hours. Subsequently, 0.55 g of antimony trioxide was added, and 1 was added in the same manner as in Example 8.
Polycondensation was carried out for 18 minutes. The polymer obtained had an intrinsic viscosity of 0.61 and a melting point of 252 ° C. The phosphorus atom residual rate was 97.5%, and the flame resistance was 5.0 times.

Comparative Example 6 1297 g of terephthalic acid, ethylene glycol 1065
g, DEPO 30.8 g and triethylamine 3.8
The mixture consisting of g was esterified according to Comparative Example 1.
Then, 0.63 g of germanium dioxide was added and Comparative Example 1
Polycondensation was carried out for 200 minutes in the same manner as in. The obtained polymer had an intrinsic viscosity as low as 0.18 and could not be spun or formed into a film at all.

Comparative Example 7 1203 g of terephthalic acid, 1030 ethylene glycol
g, itaconic acid 39.7 g and triethylamine 3.
242 a mixture consisting of 8 g under a pressure of 2.5 kg / cm ^2.
The esterification reaction was carried out at 0 ° C for 2 hours. Then, 0.55 g of antimony trioxide was added and polycondensation was carried out according to Example 1. At the time when the intrinsic viscosity of the polymer reached 0.61, the reaction system was brought to normal pressure with nitrogen gas, and 62.8 g of HCA was added thereto.
Stir for minutes. Then, the pressure of the reaction system is gradually reduced to 60
Polycondensation was carried out for 60 minutes at 0.1 mmHg per minute. The obtained polymer was colored in blackish gray. The intrinsic viscosity of the polymer was 0.63, and there was almost no increase in viscosity. Further, the melting point was 248 ° C., and the phosphorus atom residual ratio was as low as 76%. The flame resistance was 4.7 times.

[Structural Analysis of Polymer] A feature of the method for producing a flame-resistant polyester of the present invention is that the phosphorus compound (I) having no ester forming ability in the polyester production process is used.
Is reacted with an unsaturated carboxylic acid to react as an ester-forming phosphorus compound derivative to introduce a phosphorus atom into the polyester. In order to confirm this intention of the present invention, structural analysis of the polyesters obtained in the above-mentioned Examples was conducted.

(Preparation of Standard Sample) A mixture of 65 g of HCA represented by the following chemical formula and 50 g of dimethyl itaconate was reacted at 170 ° C. for 6 hours in a nitrogen atmosphere. The obtained slightly pale yellow viscous liquid was recrystallized in ethylene glycol to obtain white crystals. The structure of the white crystal was confirmed from the results of IR, H ¹ NMR and elemental analysis.

[0064]

[Chemical 7]

[0065]

[Table 1]

A mixture of 61 g of diphenylphosphine oxide represented by the following chemical formula and 50 g of dimethyl itaconate was synthesized according to the standard sample. The obtained light brown colored viscous liquid was recrystallized from methanol to obtain white crystals. The structure of the white crystal was confirmed from the results of IR, H ¹ NMR and elemental analysis, and the results are shown in Table 2.

[0067]

[Chemical 8]

[0068]

[Table 2]

A mixture of 53 g of diethylphosphine oxide represented by the following chemical formula and 80 g of dimethyl itaconate was reacted under a nitrogen atmosphere at 110 ° C. for 1 hour and then at 170 ° C. for 2 hours. The resulting yellow colored viscous liquid was purified by vacuum distillation. Boiling point of purified product is 1
It was a colorless and transparent viscous liquid of 75 to 177 ° C./0.3 mmHg. The structure of the liquid was confirmed from the results of IR, H ¹ NMR and elemental analysis.

[0070]

[Chemical 9]

[0071]

[Table 3]

[Analysis of Polymer] Each of the polymers obtained in Examples 1 to 3 was heated in a sealed tube at 250 ° C. for 8 hours to decompose methanol. This methanol decomposition product was separated by gas chromatography to isolate phosphorus compound (I). The isolated phosphorus compound was analyzed by IR, H ¹ NMR and elemental analysis, and its structure was confirmed by comparing with the result of the standard sample.

[0073]

[Table 4]

[0074]

[Table 5]

[0075]

[Table 6]

As shown by the above structural analysis results, it was confirmed that the phosphorus compound (I) was introduced into the polyester by reacting with the unsaturated carboxylic acid in the method for producing a flame-resistant polyester of the present invention. ..

[0077]

According to the method of the present invention, a flame resistant polyester capable of providing molded articles such as fibers, films and boards having excellent flame resistance and various physical properties can be produced stably and at low cost. Therefore, it is important to contribute to the social environment and industry that are derived from fire prevention and respect for people.

Claims (1)

[Claims] 1. A polyester is produced from one or more dicarboxylic acids or ester-forming derivatives thereof and one or more diols or ester-forming derivatives thereof and / or one or more oxycarboxylic acids or ester-forming derivatives thereof. In this case, the flame resistance is characterized in that the phosphorus compound represented by the following general formula (I) and an unsaturated carboxylic acid or an ester-forming derivative thereof coexist at an arbitrary stage where the intrinsic viscosity of the polyester is less than 0.5. For producing water-soluble polyester. [Chemical 1] [In the formula, R ₁ and R ₂ are the same or different and each represents an alkyl group, an aryl group or an alkoxy group (the aryl group is
An alkyl group, an alkoxy group, or a halogen atom may be substituted), and R ₁ and R ₂ may form a ring with each other.]