JP2003128771A - Flame-retardant polyester and fiber comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant polyester which has an excellent color tone, hardly develops deposits on a spinneret, even when the polyester is continu ously melt-spun through the spinneret for a long period, and has excellent moldability, and to provide a fiber using the flame-resistant polyester. SOLUTION: This flame-retardant polyester in which at least 80 mol.% of repeating units constituting the polyester are ethylene terephthalate units, and which is copolymerized with a phosphorus compound A represented by a specific structure in an amount of 0.3 to 1.5 wt.% as phosphorus on the basis of the weight of the polyester is characterized by using a titanium/phosphorus reaction product obtained by thermally reacting a titanium compound represented by a specific structure with a phosphorus compound B represented by formula (III) (see the specification) in a phosphorus element (P)/titanium element (Ti) of 1 to 4 in ethylene glycol and controlling the content of the titanium in the polyester to 2 to 40 mmol.%. And the fiber comprises the flame-resistant modified polyester.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polyester and a fiber comprising the same. More specifically, using a catalyst for producing a polyester containing a specific titanium compound and phosphorus compound, the color tone is excellent, and the amount of spinneret deposits is extremely small even when continuously spun through the spinneret for a long time. The present invention relates to a polyester having high flame retardancy and a fiber comprising the same, which has excellent performance of being excellent.

[0002]

2. Description of the Related Art Polyesters, particularly polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate and polytetramethylene terephthalate are excellent in mechanical, physical and chemical properties, and therefore, fibers, films and other molded products are obtained. Widely used in. However, polyester is flammable like many other chemical fibers, but in recent years, there has been an increasing demand for flame retardancy from the viewpoint of respect for human life and fire prevention. The flame-retardant properties are not sufficient to use such polyesters as fibers for clothing or fibers for non-clothing mainly in interiors such as curtains and interior covers. Conventionally, in order to make up for such drawbacks, as a flame retarding technique, a post-processing method of adding phosphorus and a halogen-based flame retardant after molding, and a blending method of adding a flame retardant during molding are known. However, since all of these are merely added with agents, there is a problem in terms of durability. Therefore, a method of copolymerizing a flame retardant in a polymerization step is known (JP-A-5-106168, JP-A-6-106168).
-13666 publication).

By the way, in such a flame-retardant polyester, usually terephthalic acid and ethylene glycol are directly esterified or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol. Alternatively, terephthalic acid is reacted with ethylene oxide to produce an ethylene glycol ester of terephthalic acid and / or a low polymer thereof, and then the reaction product is heated under reduced pressure in the presence of a polycondensation catalyst to give a predetermined amount. It is manufactured by polycondensation reaction until it reaches the degree of polymerization.

It is well known that the type of catalyst used in these polycondensation reaction steps greatly influences the reaction rate and the quality of the obtained polyester. Flame-retardant polyester can be subjected to polycondensation reaction using the same polycondensation catalyst as known polyesters, for example, antimony compounds are most widely used because they have excellent polycondensation catalyst performance. There is.

However, in the case of a polyester using an antimony compound as a polycondensation catalyst, when the polyester is continuously melt-spun for a long period of time, the reduced antimony metal becomes foreign matter and the pressure (pack pressure) in the spinning filtration section is increased. There is a problem that the rise of In addition, foreign matter (hereinafter, sometimes simply referred to as the foreign matter of the die) adheres and accumulates around the mouth of the die, causing a bending phenomenon (bending) of the molten polyester flow, which causes fluff and spinning in the spinning and drawing processes. And / or there is a problem of formability such as yarn breakage. As a result, they have been a cause of markedly reducing productivity.

It has also been proposed to use a titanium compound such as titanium tetrabutoxide as a polycondensation catalyst other than the antimony compound. However, when such a titanium compound is used, the problem of moldability due to the accumulation of foreign matter on the die as described above can be solved, but the obtained polyester itself is colored yellow, and the melt thermal stability is also high. There is a new problem of being defective.

In order to solve the above coloring problem, it is generally practiced to add a cobalt compound to polyester to suppress yellowing. It is true that the yellowing (b value) of polyester can be improved by adding a cobalt compound, but the addition of the cobalt compound lowers the melt thermal stability of the polyester and makes it easier for the polyester to decompose. There's a problem.

Further, as another titanium compound, Japanese Patent Publication No.
No. 8-2229 discloses titanium hydroxide and Japanese Patent Publication No.
JP-A 7-26597 discloses the use of α-titanic acid as a catalyst for polyester production. However, in the former method, it is not easy to pulverize titanium hydroxide into powder, while in the latter method, α-titanic acid is likely to be deteriorated, so that its storage and handling are not easy.
Therefore, neither is suitable for industrial use, and it is also difficult to obtain a polyester having a good yellowness (b value).

Further, JP-B-59-46258 discloses a product obtained by reacting a titanium compound with trimellitic acid, and JP-A-58-38722 discloses a titanium compound and a phosphite. It is disclosed that each of the products obtained by reacting with and is used as a catalyst for producing polyester. Certainly, according to these methods, the melt heat stability of the polyester is improved to some extent, but the color tone of the obtained polyester is not sufficient. In order to suppress the generation of foreign matter in the die, it is an effective means not to use an antimony compound as a catalyst as described above. It could not be used.

Therefore, there is a demand for polyester fibers which are less likely to cause foreign matter in the die and have an excellent color tone.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide an excellent color tone, and even when continuously spun for a long time, the increase in pack pressure and the amount of foreign matter in the die are very small, the moldability is excellent, and the high productivity is achieved. A flame-retardant polyester having improved properties and improved color tone, and a fiber using the same.

[0012]

The present inventors have completed the present invention as a result of extensive studies to achieve the above object. That is, the present invention is: At least 80 mol% of the repeating units constituting the polyester are ethylene terephthalate units,
Formula (I)

[0013]

[Chemical 5]

(In the formula, R is a saturated, linear, branched or cyclic alkylene group having 10 or less carbon atoms, and 6 to 6 carbon atoms.
An arylene group having 10 carbon atoms or an arylalkylene group having 7 to 10 carbon atoms, and R ₁ represents an alkyl group having 6 or less carbon atoms, an aryl group having 6 to 10 carbon atoms, or an arylalkyl group having 7 to 10 carbon atoms. R ₂ and R ₃ have a carbon number of 1 to
It represents an alkyl group having 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a hydrogen atom. ) The phosphorus compound A represented by 0.3 to 1.5 as a phosphorus element based on the polyester component.
In the polyester copolymerized by weight, the following formula (II) is used as a catalyst during polyester polymerization.

[0015]

[Chemical 6]

(Wherein R ₄₁ , R ₄₂ , R ₄₃ and R ₄₄ are the same or represent an alkyl group having 2 to 10 carbon atoms,
m represents an integer of 1 to 3. ) And a titanium compound represented by the following formula (III)

[0017]

[Chemical 7]

(In the formula, R ₅ is an alkyl group having 2 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms, and n is 1
Alternatively, 2 and p are 0 or 1. ), A titanium / phosphorus reaction product obtained by heating and reacting phosphorus compound B in ethylene glycol with a composition in which the number of moles of phosphorus element relative to the number of titanium element (P / Ti) is 1 to 4 is used. A flame-retardant polyester, characterized in that the amount of titanium element contained in the polyester is in the range of 2 to 40 mmol% with respect to the total dicarboxylic acid component.

2. In the phosphorus compound B of the above formula (III), p = 0. Flame-retardant polyester described in.

3. 1. The phosphorus compound B of the above formula (III) is a monoarylphosphonic acid.2. Flame-retardant polyester described in.

4. In the phosphorus compound B of the above formula (III), p = 1. Flame-retardant polyester described in.

5. 3. The phosphorus compound B of the above formula (III) is a monoalkyl phosphate. Flame-retardant polyester described in.

6. The titanium compound of the above formula (II) is at least one compound selected from the group consisting of titanium tetraalkoxides, octaalkyl trititanates, and hexaalkyl dititanates. ~ 5. The flame-retardant polyester according to any one of 1.

7. The titanium compound of the above formula (II) is previously prepared by the following formula (IV)

[0025]

[Chemical 8]

(In the above formula, q represents an integer of 2 to 4)
After reacting with a polyvalent carboxylic acid represented by and / or an acid anhydride thereof at a composition in a reaction molar ratio range of (2: 1) to (2: 5), the phosphorus compound B of the above formula (III) is added. Characterized by reacting 1. ~ 6. The flame-retardant polyester according to any one of 1.

8.1. ~ 7. A flame-retardant polyester fiber obtained by melt spinning the polyester described in any one of 1.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

In the polyester of the present invention, at least 80 mol% or more of the repeating units must be ethylene terephthalate units. When the ethylene terephthalate unit content is less than 80 mol%, basic physical properties such as strength and elongation of the obtained polyester fiber cannot be sufficiently maintained, which is not preferable.

The phosphorus compound A in the present invention acts as a flame retardant and has the following formula (I)

[0031]

[Chemical 9]

(In the formula, R is a saturated, linear, branched or cyclic alkylene group having 10 or less carbon atoms, and 6 to 6 carbon atoms.
An arylene group having 10 carbon atoms or an arylalkylene group having 7 to 10 carbon atoms, and R ₁ represents an alkyl group having 6 or less carbon atoms, an aryl group having 6 to 10 carbon atoms, or an arylalkyl group having 7 to 10 carbon atoms. R ₂ and R ₃ have a carbon number of 1 to
It represents an alkyl group having 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a hydrogen atom. ) Is a compound represented by.

In the above formula (I), R is a saturated, linear, branched or cyclic alkylene group having 10 or less carbon atoms, an arylene group having 6 to 10 carbon atoms, or 7 to 7 carbon atoms.
10 represents the arylalkylene group. When R is a functional group having a large number of carbon atoms other than these, the thermal stability of the R group portion becomes poor, which is not preferable. Preferable examples of R include ethylene group, propylene group, phenylene group and the like. R ₁ represents an alkyl group having 6 or less carbon atoms, an aryl group having 6 to 10 carbon atoms, or an arylalkyl group having 7 to 10 carbon atoms. If R ₁ is a functional group having a large number of carbon atoms other than these, the R ₁ portion is likely to be thermally decomposed, which is not preferable. Further, groups in which R and / or R ₁ contain one or more heteroatoms are also preferred. In particular, it may contain F, Cl, O or S.

R ₂ and R ₃ represent an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a hydrogen atom. When the number of carbon atoms exceeds 18, it becomes difficult for the phosphorus compound to copolymerize with the polyester molecular chain by the transesterification reaction, and the durability becomes inferior like the addition type flame retardant, which is not preferable.

Specific compounds of phosphorus compound A include
3-methyl-phosphinicopropionic acid, 2-methyl-2,5-dioxo-1,2-oxaphosphorane,
3-ethyl-phosphinicopropionic acid, 3-phenyl-phosphonicopionic acid, 2-phenyl-2,
5-dioxo-1,2-oxaphosphorane and the like can be mentioned.

The phosphorus compound A in the present invention is 0.3 to 1.5% by weight as a phosphorus element based on polyester.
Must be copolymerized within the range. When the copolymerization amount is less than 0.3% by weight as elemental phosphorus, the flame retarding effect becomes poor, which is not preferable. On the other hand, if the phosphorus element content exceeds 1.5% by weight, the heat resistance of the polyester fiber as a whole becomes poor, resulting in poor physical properties of the obtained polyester fiber.
Further, the thermally-decomposed organic foreign matter causes a remarkable increase in pack pressure, which is not preferable.

The polyester in the present invention has a third component other than the ethylene terephthalate component which constitutes the polyester.
The components may be copolymerized, and the third component may be either a dicarboxylic acid component or a glycol component. Third
Examples of the dicarboxylic acid component preferably used as the component include aromatic dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid and phthalic acid, adipic acid, azelaic acid, sebacic acid, decandicarboxylic acid. Examples thereof include aliphatic dicarboxylic acids such as acids and the like, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, etc., and examples of the glycol component include diols such as diethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexanedimethanol. These may be used alone or in combination of two or more.

The flame-retardant polyester and fiber of the present invention have the following formula (II)

[0039]

[Chemical 10]

(Wherein R ₄₁ , R ₄₂ , R ₄₃ and R ₄₄ are the same or different and each represents an alkyl group having 2 to 10 carbon atoms, and m is an integer of 1 to 3). Compound and the following formula (III)

[0041]

[Chemical 11]

(In the formula, R ₅ is an alkyl group having 2 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms, and n is 1
Alternatively, 2 and p are 0 or 1. ) Are polymerized using a titanium / phosphorus reaction product obtained by reacting the phosphorus compound B represented by the formula (1) with a composition in which the number of moles of phosphorus element to the number of moles of titanium element (P / Ti) is 1 to 4. There is a need.

If the number of moles of phosphorus element relative to the number of moles of titanium element (P / Ti) is less than 1, the polyester obtained may have a poor color tone and its heat resistance may deteriorate, which is not preferable. If greater than 4,
The catalytic activity for the polyester polycondensation reaction becomes insufficient, which is not preferable. The number of moles of phosphorus element relative to the number of moles of titanium element (P / Ti) is preferably in the range of 1.2 to 3.5, and more preferably in the range of 1.5 to 3.0.

Further, the catalyst preparation of the titanium compound component and the phosphorus compound B component needs to be heated and reacted in ethylene glycol. As a reaction method, for example, the component consisting of the phosphorus compound B and ethylene glycol are mixed. Then, a part or all of the phosphorus compound B component is dissolved in a solvent, the titanium compound component is added dropwise to this mixed solution, and the reaction system is heated to a temperature of 0 ° C to 200 ° C for 30 minutes or more, preferably 60 ° C.
It is carried out by heating to a temperature of ~ 150 ° C for 40 to 90 minutes. In this reaction, there is no particular restriction on the reaction pressure, and it is usually carried out under normal pressure.

Examples of the titanium compound represented by the above formula (II) include titanium tetrabutoxide, titanium tetraisopropoxide, titanium tetra-n-propoxide, titanium tetraethoxide and titanium tetraoctyloxide. Examples thereof include titanium tetraalkoxide, octaalkyl trititanate, hexaalkyl dititanate, and the like.

As the phosphorus compound B represented by the above formula (III), the case where p = 0 in the above formula is preferably mentioned. For example, monoaryl sulfonic acid and the like, specifically, phenylphosphonic acid, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid, butylphosphonic acid, tolylphosphonic acid, xylylphosphonic acid, biphenylphosphonic acid, Naphthylphosphonic acid, anthrylphosphonic acid, 2-carboxyphenylphosphonic acid, 3-carboxyphenylphosphonic acid, 4-carboxyphenylphosphonic acid, 2,3-dicarboxyphenylphosphonic acid, 2,4-dicarboxyphenylphosphonic acid, 2,5-dicarboxyphenylphosphonic acid,
2,6-dicarboxyphenylphosphonic acid, 3,4-dicarboxyphenylphosphonic acid, 3,5-dicarboxyphenylphosphonic acid, 2,3,4-tricarboxyphenylphosphonic acid, 2,3,5-tricarboxy Phenylphosphonic acid, 2,3,6-tricarboxyphenylphosphonic acid, 2,4,5-tricarboxyphenylphosphonic acid, 2,4,6-tricarboxyphenylphosphonic acid,
Etc.

The case of p = 1 is also preferred.
Examples thereof include monoalkyl phosphate and the like, and specifically, monomethyl phosphate, monoethyl phosphate, monotrimethyl phosphate, mono-n-butyl phosphate, monoheptyl phosphate, monohexyl phosphate, monoheptyl phosphate, monononyl phosphate, monodecyl phosphate. , Monododecyl phosphate, monophenyl phosphate, monobenzyl phosphate, mono (4-dodecyl) phenyl phosphate, mono (4-methylphenyl) phosphate, mono (4-ethylphenyl) phosphate, mono (4-propylphenyl) phosphate, mono (4-dodecylphenyl) phosphate, monotolyl phosphate, monoxylyl phosphate, monobiphenyl phosphate,
Examples thereof include mononaphthyl phosphate and monoanthryl phosphate.

The titanium compound represented by the above formula (II) is previously represented by the following formula (IV)

[0049]

[Chemical 12]

(In the above formula, q represents an integer of 2 to 4)
A method of using by reacting with a polyvalent carboxylic acid represented by and / or an acid anhydride thereof is also preferably used. In that case, the reaction molar ratio of the titanium compound to the polycarboxylic acid and / or its acid anhydride is preferably in the range of (2: 1) to (2: 5). A particularly preferred range is (1: 1) to (1: 2).

The amount of titanium element contained in the flame-retardant polyester of the present invention must be 2 to 40 mmol% based on the total dicarboxylic acid residue component. When the amount of titanium element is less than 2 mmol%, the polycondensation reaction becomes slow,
When it exceeds the millimole%, the color tone of the obtained polyester may be poor and the heat resistance thereof may be deteriorated, which is not preferable. The amount of titanium element is preferably in the range of 5 to 35 mmol%, more preferably in the range of 10 to 30 mmol%.

The method for producing the flame-retardant polyester of the present invention using the catalyst thus produced is not particularly limited,
It can be produced by a conventionally known method such as a melt polycondensation method or a solid phase polymerization method.

Further, the flame-retardant polyester fiber of the present invention is not particularly limited as a production method, and can be produced by a conventionally known melt spinning method. For example, it is preferable to produce polyester by melt spinning in the range of 270 ° C. to 300 ° C., and the melt spinning speed is 400 to 5000.
Spinning at m / min is preferred. When the spinning speed is in this range, the strength of the obtained fiber is sufficient and the fiber can be wound stably. In addition, the stretched yarn can be obtained by winding the polyester fiber or by continuously stretching the fiber without once winding it. Further, the flame-retardant polyester fiber of the present invention is preferably subjected to alkali weight reduction treatment in order to enhance the feeling.

In producing the flame-retardant polyester fiber of the present invention, there is no limitation on the shape of the spinneret used during spinning, and any shape such as circular, irregular, solid or hollow can be adopted.

The flame-retardant polyester fiber in the present invention can be dyed with a conventionally used dye, and a flame-retardant polyester fiber having a clear and excellent color tone can be obtained.

[0056]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, the part in an Example shows a weight part. Various characteristics were evaluated by the following methods. (1) Intrinsic viscosity [η]: Measured at 35 ° C. using orthochlorophenol as a solvent, and determined from the relative viscosity by a conventional method. (2) Color tone (L value and b value): 290 for polymer sample
Melt for 10 minutes under vacuum at ℃, form a plate with a thickness of 3.0 ± 1.0 mm on an aluminum plate, then immediately quench in ice water, and dry the plate at 160 ℃ for 1 hour. The plate was placed on a white standard plate for color difference meter adjustment, and the Hunter L value and b value on the plate surface were measured using a Hunter type color difference meter CR-200 manufactured by Minolta.
The L value indicates lightness, the larger the value, the higher the lightness, and the larger the value, the larger the degree of yellowness. (3) Metal element content: fluorescent X-ray measuring device 3 manufactured by Rigaku Corporation
270 was used. (4) Evaluation of pressure rise in the spinning filter: 24 just above the spinneret
2 in a spinning machine equipped with a wire mesh of 00 mesh 25 mm in diameter
Polyester chips were discharged at 30 g / min at 90 ° C. for 7 days, and the filtration pressurization per day was obtained. (5) Evaluation of spinneret foreign matter generated in the spinneret: Polyester was used as a chip, which was melted at 290 ° C. and the pore size was adjusted to 0.
Discharge from a spinneret with 15 mmφ and 12 holes, 600
The layer was spun at m / min for 2 days, and the height of the layer of the foreign substance on the die generated at the outer edge of the die outlet was measured. The higher the height of the foreign substance layer of the die, the easier the bending of the filamentous flow of the molten polyester discharged, and the lower the moldability of this polyester. That is, the height of the spinneret foreign substance layer generated in the spinneret is an index of the moldability of the polyester. (6) Flame retardancy: The polyester multifilament produced was twisted and subjected to SZ twisting at 2500 T / M, and a taffeta fabric was woven using this yarn. About 35 from the fabric
Sampling a 0 mm x 250 mm fabric sample,
The woven fabric sample was subjected to JIS L1091 A1 method (45
The afterflame time was measured by the micro burner method). The measurement was performed for each of the three samples and expressed as the average afterflame time. The practically allowable afterflame time is 3 seconds or less.

[Reference Example 1] 3.5 parts by weight of phenylphosphonic acid was dissolved in 131 parts by weight of ethylene glycol by heating at 120 ° C for 10 minutes. 134.5 parts by weight of this ethylene glycol solution was further added with 40 parts of ethylene glycol.
After adding parts by weight, titanium tetrabutoxide 3.
8 parts by weight were dissolved. The resulting reaction system was heated at 120 ° C for 6
After stirring for 0 minutes, the titanium compound was reacted with phenylphosphonic acid to obtain a white slurry of the catalyst containing the reaction product. The titanium content of this catalyst slurry was 0.3% by weight.

[Reference Example 2] 0.8 parts by weight of trimellitic anhydride was dissolved in 2.5 parts by weight of ethylene glycol, and 0.7 part by weight of titanium tetrabutoxide (based on the molar amount of trimellitic acid anhydride) was added to this solution. 0.5 mol%) was added dropwise, and the reaction system was kept in the air at 80 ° C. for 60 minutes under atmospheric pressure to react titanium tetrabutoxide with trimellitic anhydride to age the reaction product. After that, the reaction system was cooled to room temperature, 15 parts by weight of acetone was added thereto, and the precipitate was separated into No. 5. Filter with 5 filter paper and collect it.
It was dried at the temperature of 2 hours. The titanium content of the obtained reaction product was 11.2% by weight.

Next, 3.5 parts by weight of phenylphosphonic acid was dissolved in 131 parts by weight of ethylene glycol by heating at 120 ° C. for 10 minutes. This ethylene glycol solution 13
After further adding 40 parts by weight of ethylene glycol to 4.5 parts by weight, 5.0 parts by weight of the above titanium compound was dissolved therein. The resulting reaction system is stirred at 120 ° C. for 60 minutes to react the titanium compound with phenylphosphonic acid,
A white slurry of catalyst containing the reaction product was obtained. The titanium content of this catalyst slurry was 0.3% by weight.

Reference Example 3 3.5 parts by weight of mono-n-butyl phosphate were dissolved in 131 parts by weight of ethylene glycol by heating at 120 ° C. for 10 minutes. After adding 40 parts by weight of ethylene glycol to 134.5 parts by weight of this ethylene glycol solution, 3.8 parts by weight of titanium tetrabutoxide was dissolved therein. The reaction system obtained was 1
The mixture was stirred at 20 ° C. for 60 minutes to react the titanium compound with mono-n-butyl phosphate to obtain a white slurry of the catalyst containing the reaction product. The titanium content of this catalyst slurry was 0.3% by weight.

[Reference Example 4] 0.8 parts by weight of trimellitic anhydride was dissolved in 2.5 parts by weight of ethylene glycol, and 0.7 parts by weight of titanium tetrabutoxide was added to the solution. 0.5 mol% based on the molar amount of mellitic acid) was added dropwise, and the reaction system was kept at 80 ° C. for 60 minutes in air under normal pressure to react titanium tetrabutoxide with trimellitic anhydride, thereby producing a reaction. Aged. Then cool the reaction system to room temperature,
Acetone (15 parts by weight) was added to this, and the precipitate was collected. It was filtered with 5 filter paper, collected, and dried at a temperature of 100 ° C. for 2 hours. The titanium content of the obtained reaction product was 11.2.
% By weight.

Next, 120 parts of 3.5 parts by weight of mono-n-butyl phosphate were added to 131 parts by weight of ethylene glycol.
It melt | dissolved by heating at 10 degreeC for 10 minutes. After adding 40 parts by weight of ethylene glycol to 134.5 parts by weight of this ethylene glycol solution, 5.0 parts of the above titanium compound was added thereto.
Part by weight was dissolved. The obtained reaction system is 60 at 120 ° C.
After stirring for a minute, the titanium compound was reacted with mono-n-butyl phosphate to obtain a white slurry of the catalyst containing the reaction product. The titanium content of this catalyst slurry was 0.3% by weight.

Example 1 90 parts of terephthalic acid and 55 parts of ethylene glycol were esterified at 0.1 MPa and 250 ° C. Then, the obtained reaction product was placed in a polycondensation flask equipped with a rectification column, and 3.1 parts of 3-methyl-phosphinico-propionic acid as a flame retardant, 20%
1.7 parts of titanium oxide ethylene glycol slurry of
1.92 slurry produced in Reference Example 1 as polycondensation catalyst
Parts by weight (20 mmol% in terms of titanium atom based on the amount of terephthalic acid + isophthalic acid) were added, and the obtained reaction system was subjected to polycondensation reaction under high vacuum at a temperature of 285 ° C. and 30 Pa to obtain The obtained polyester was made into chips according to a conventional method. The obtained polymer has an intrinsic viscosity of 0.50.
The amount of titanium element was 20 mmol% with respect to the terephthalic acid residue component + isophthalic acid residue component. The chips were dried and dried at 160 ° C. for 4 hours, spun at 290 ° C., stretched 4.3 times, and then 83.25 dtex / 24 fi.
l of multifilament was obtained. The results are shown in Tables 1 and 2.

[Examples 2 to 4, Comparative Example 1] The procedure of Example 1 was repeated, except that the catalyst was changed as shown in Table 1.
The results are shown in Tables 1 and 2.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

EFFECTS OF THE INVENTION According to the present invention, a Ti catalyst is used to eliminate the deterioration of hue, which is a drawback of the prior art, enables stable spinning with a small amount of foreign matter in the spinneret, is excellent in hue, and has excellent flame retardancy. It is possible to provide flame-retardant polyester and fibers having properties.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // D01F 6/62 306 D01F 6/62 306E F term (reference) 4J029 AA03 AB01 AB04 AC02 AE02 BA03 CB06A JC161 JC562 JC571 JC581 JF251 KB03 4L035 BB31 EE14 JJ25 JJ29

Claims (8)

[Claims] 1. At least 80 mol% of the repeating units constituting the polyester are ethylene terephthalate units, and the following formula (I): (In the formula, R represents a saturated, linear, branched or cyclic alkylene group having 10 or less carbon atoms, an arylene group having 6 to 10 carbon atoms, or an arylalkylene group having 7 to 10 carbon atoms, and R ₁ represents carbon. C6 or less alkyl group, C6-10
Or an arylalkyl group having 7 to 10 carbon atoms. R ₂ and R ₃ represent an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a hydrogen atom. In the polyester in which 0.3 to 1.5% by weight of phosphorus compound A represented by the formula (1) is copolymerized as a phosphorus element based on the weight of the polyester, the following formula (II): ] (In the formula, R ₄₁ , R ₄₂ , R ₄₃ and R ₄₄ each represent the same or different alkyl group having 2 to 10 carbon atoms, and m is 1
Represents an integer of 3; ) And a titanium compound represented by the following formula (III): (In the formula, R ₅ is an alkyl group having 2 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms, and n is 1 or 2, p
Is 0 or 1. ) The phosphorus compound B represented by
Using a titanium / phosphorus reaction product obtained by heating and reacting in ethylene glycol with a composition in the range of 1 to 4, and the amount of titanium element contained in the polyester is 2 to 40 mmol based on all dicarboxylic acid residue components. % Flame-retardant polyester used. 2. The flame-retardant polyester according to claim 1, wherein in the phosphorus compound B of the formula (III), p = 0. 3. The flame-retardant polyester according to claim 2, wherein the phosphorus compound B of the formula (III) is a monoarylphosphonic acid. 4. The flame-retardant polyester according to claim 1, wherein in the phosphorus compound B of the formula (III), p = 1. 5. The flame-retardant polyester according to claim 4, wherein the phosphorus compound B of the formula (III) is a monoalkyl phosphate. 6. The titanium compound of the formula (II) is at least one compound selected from the group consisting of titanium tetraalkoxides, octaalkyl trititanates and hexaalkyl dititanates. The flame-retardant polyester according to any one of 1. 7. A titanium compound of the above formula (II) is previously prepared from the following formula (IV): (In the above formula, q represents an integer of 2 to 4) and a composition having a reaction molar ratio of (2: 1) to (2: 5) with the polyvalent carboxylic acid and / or its acid anhydride represented by The flame-retardant polyester according to any one of claims 1 to 6, wherein the flame-retardant polyester is reacted with the phosphorus compound of the formula (III). 8. A flame-retardant polyester fiber obtained by melt-spinning the polyester according to claim 1.