JPS636022A - Preparation of modified polyester - Google Patents

Abstract

PURPOSE:To reduce the amt. of insoluble foreign substances, by adding a heat- treated product of an isophthalic acid compd. having a metal sulfonate group with an amine compd. and/or an alkali metal compd. to an esterified product in such a ratio that a specified relation should be satisfied. CONSTITUTION:A treated product obtd. by heat-treating an isophthalic acid compd. having a metal sulfonate group represented by formula I with an amine compd. and/or an alkali metal compd. in ethylene glycol in advance (hereinafter called the compd. A) is added to an esterified or ester-exchanged product of a difunctional arom. carboxylic acid compd. and a difunctional glycol in such a ratio that the compd. A satisfies the relationship II. After the polycondensation reaction system is temporarily kept under an ordinary pressure, the polycondensation reaction is carried out under reduced pressure. In formula I, R1 and R2 are H, -CnH2n+1 (n=1-4), etc.; M is a metal atom such as Na, K, etc. In formula II, X is the average degree of polymerization of the esterified product when the heat-treated product is added; Y is the quantity of the compd. A added (m mol% based on the difunctional arom. carboxylic acid compd.).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a modified polyester that has excellent productivity and is easily dyed with basic dyes.

(Prior art) Polyester, especially polyester whose main acid component is terephthalic acid, has excellent mechanical, physical, and chemical properties, so it is widely used in fibers, films, and other molded products.
It's being used.

However, such polyester fibers have insufficient dyeability, and many attempts (and proposals) have been made to improve the dyeability. A method of copolymerizing a sulfonate group-containing isophthalic acid compound is known as a preferred method for improving dyeability with basic dyes.

However, the copolymerized polyester of such a metal sulfonate group-containing isophthalic acid compound (hereinafter sometimes referred to as modified polyester) is used as a polyester that is usually employed! 8! Direct esterification method, i.e., polycondensation reaction of the esterification reaction product of mainly terephthalic acid and mainly ethylene glycol, or polycondensation of the transesterification reaction product of mainly dimethyl terephthalate and mainly ethylene glycol. When produced by a reaction transesterification method, insoluble foreign substances are likely to be generated in the resulting polymer, resulting in a high rate of increase in pack pressure during molding, particularly during melt spinning. For this reason, if the spinning bank pressure is too high (if the spinning bank pressure becomes too high, the number of spun yarn breakages will increase and/or the number of drawn yarn breakage will increase).
Problems arise such as an increase in fuzz, which deteriorates the quality of the spinning process and/or the quality of the drawing process, and furthermore, worsens process passability in the Takaku-Uko process, or deteriorates the quality of the final product.
Spinning punctures must be replaced in a short period of time, which significantly reduces productivity.

As a way to improve this drawback of reduced productivity,
JP-A-58-138731 also proposes regulating the addition ratio of an alkali metal compound and a phosphorus-containing compound to be used together with a metal sulfonate group-containing isophthalic acid compound, but the resulting modified polyester is not necessarily satisfactory. The reality is that it cannot be said that it has the level of productivity that could be achieved.

%K, the modified polyester obtained by the direct esterification method has more insoluble foreign substances in the polymer than the modified polyester obtained by the transesterification method.
For example, a method (%
Publication No. 51-41795), or bis(p-hytoxyethyl) of isophthalic acid containing a metal sulfonate group.
A method of adding an ethylene glycol solution of an ester and an alkali metal compound to an esterification reaction product (Japanese Patent Application Laid-open No.
No. 2-47098 (1% Publication No. 1987-106922)) have been proposed.

However, according to the studies conducted by the present inventors, it was found that even in the modified polyester obtained by this method, insoluble foreign substances in the polymer were not sufficiently reduced, and the rate of increase in spinning back pressure was still large. did.

(Object of the Invention) The object of the present invention is to provide a modified polyester in which insoluble foreign substances in the polymer, which cause an increase in spinning puncture pressure, are significantly reduced in the modified polyester co-incorporated with a metal sulfonate group-containing isophthalic acid compound. The objective is to provide a manufacturing method.

(Structure) As a result of studies to achieve the above objectives, the present inventors determined that the amount of the alkali metal compound added together with the metal sulfonate group-containing isophthalic acid compound and the average degree of esterification reaction or transesterification reaction product. It has been discovered that insoluble foreign substances in the obtained modified polyester can be reduced if the relationship between the above and the above is within a certain range, and the present invention has been achieved based on this finding.

That is, the present invention provides a method for producing a polyester by subjecting an esterification reaction or transesterification reaction product of a difunctional aromatic carboxylic acid compound and a difunctional glycol to a polycondensation reaction in the presence of a polycondensation catalyst. A metal sulfonate group-containing isophthalic acid compound represented by the following formula CI) and an amine compound and/or an alkali metal compound are added to the reaction product obtained after the esterification reaction or transesterification reaction is substantially completed. The treated product obtained by heat treatment in advance is added to the amine compound and/or alkali metal compound so that the added W food satisfies the following formula (II), and then the polycondensation reaction system is once heated under normal pressure. This is a method for producing a modified polyester, which is characterized in that it is held and then subjected to a polycondensation reaction under reduced pressure.

General formula CI) 808M [II] Formula % Formula % As the difunctional aromatic carboxylic acid compound (hereinafter sometimes referred to as difunctional carboxylic acid) used as a raw material for polyester in the present invention, terephthalic acid is the main target. As the ester-forming wire conductor, lower dialkyl esters having 1 to 4 carbon atoms, phenyl esters, etc. are preferably used. Further, a part (usually 20 mol % or less) of this terephthalic component may be replaced with a bifunctional carboxylic acid other than terephthalic acid or an ester-forming derivative thereof. Examples of difunctional carboxylic acids other than terephthalic acid include difunctional aromatic acids such as isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, and β-hydroxyethoxybenzoic acid. Examples include group carboxylic acids.

Moreover, as the bifunctional glycol, ethylene glycol is mainly used. Also, instead of ethylene glycol, other glycols such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol,
Fatty glycols such as cyclohexane-1,4-dylotyl may also be used, with tetramethylene glycol being preferred. It is also possible to replace a part of the main glycol with another glycol or diol compound.

Any method can be used to produce polyester from such a difunctional carboxylic acid compound and a difunctional glycol, but for polyethylene terephthalate, terephthalic acid and ethylene glycol are subjected to an esterification reaction, or terephthalate is A first stage reaction is a transesterification reaction of a lower fullkyl ester such as dimethyl terephthalic acid and ethylene glycol to produce a glycol ester of terephthalic acid and/or a low polymer thereof, and the reaction product of this first stage is transesterified under reduced pressure. Generally, a method of manufacturing using a trap and a second-stage reaction in which a condensation reaction is carried out using heat from a rabbit is generally used.

Any catalyst can be used in these reactions depending on the reaction. Among these, when employing the transesterification method, calcium compounds, manganese compounds, magnesium compounds, zinc compounds, cobalt compounds, etc. are preferred as the transesterification medium, and these may be used alone or in combination of two or more. The amount used is 0.01 to 0.1 based on the difunctional carboxylic acid component used as the polyester raw material.
Mol% is preferred.

Also, antimony compounds are used as polycondensation catalysts.

Titanium compounds and germanium compounds are preferred, and organic titanium compounds, especially reaction products obtained by reacting titanium tetraalkoxide and trimellitic anhydride in ethylene glycol, are preferred.

Incidentally, the titanium compound can be obtained by the method described in JP-A-53-45395.

These polycondensation catalysts can also be used alone or in combination.
The amount used is 0.00 per bifunctional carboxylic acid component trap.
3 to 0.1 mol% is preferred.

In the present invention, during the production of the polyester, the esterification reaction or transesterification reaction product is heat-treated with a metal sulfonate group-containing isophthalic acid compound and an amine compound and/or an alkali metal compound in ethylenethenephthalate. It is important to add the treated product obtained at ℃.

The metal sulfonate group-containing isophthalic acid compound used in the present invention is represented by general formula (I).

OsM Preferable compounds represented by the above formula (I3 include 5-sodium dimethyl sulfoisophthalate, 5
- Lithium dimethyl sulfoisophthalate, 5-sodium sulfoisophthalate bis(p-hydroxyethyl) ester, 5-lithium sulfoisophthalate bis(p-hydroxyethyl) ester, and the like. Among them, 5-sodium sulfoisophthalate bis(p-hydroxyethyl)
Esther is preferable.

Such a metal sulfonate group-containing isophthalic acid compound is
0 for the difunctional aromatic carboxylic acid compound that is the raw material
．． It is preferable to copolymerize 5 to 10 mol%, particularly preferably 1.0 to 6.0 mol%.

If the metal sulfonate group isophthalic acid compound is less than 0.5 mol %, the resulting modified polyester tends to have insufficient affinity for basic dyes, and if it exceeds 10 mol %, the excellent properties unique to polyester may be lost. Not only is the quality impaired, but the manufacturing cost of the polyester tends to increase.

Examples of the amine compound and/or alkali metal compound to be heat-treated with the metal sulfonate group-containing isophthalic acid compound include triethanolamine and tetrabutyl heptanium hydroxide.

Examples include tetrabutylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, sodium acetate, and lithium acetate. Among them, tetrabutylammonium bromide,
Sodium acetate is preferred.

Such amine compound and/or alkali metal compound additive MJ violet (Y) has the following (II ) is a child who satisfies the formula.

6l-11X≦Y≦233-33X ・・・・・・
[II] M (sometimes referred to as DEC) is at a significantly high concentration (as a result, the softening point, heat resistance, and weather resistance of the modified polyester decreases. The resulting insoluble foreign matter also increases, causing an increase in spinning puncture pressure.

On the other hand, when Y>233-33x), the amount of insoluble foreign substances in the obtained modified polyester increases again. Particularly, when titanium dioxide is added as a matting agent to produce a matte modified polyester, the titanium dioxide particles agglomerate significantly and the spinning pack pressure increases rapidly.

Generally, as shown in the examples below, the average degree of polymerization of the Nisderization reaction product is higher than that of the transesterification reaction product, so when the direct esterification method is used, the transesterification method is used. It is necessary to reduce the amount of the amine compound and/or alkali metal compound added than in the case. In this regard, in the above-mentioned JP-A-52-47098 and JP-A-56-106922, since the amount of alkali metal compound added is large, a large amount of insoluble foreign matter (easily generated) is present in the resulting polymer. .

In the present invention, the heat treatment of the metal sulfonate group-containing isophthalic oxidized metal material and the amine compound in ethylene glycol is carried out at a temperature of 50 to 150°C.
Preferably, the heat treatment is performed for a minute.

If the heat treatment temperature or time is outside the above range, the effect of suppressing the by-product of DEC and metal sulfonate group isophthalic acid compounds (caused by insoluble foreign matter) tends to be insufficient. In particular, if the heat treatment is performed at room temperature without heat treatment, When treated, the DEC and insoluble foreign substances increase rapidly.

The heat-treated product obtained in this way is added to the reaction product obtained after the esterification reaction or transesterification reaction is substantially completed, and the polycondensation reaction is carried out under reduced pressure after being maintained under normal pressure. Start.

Here, if the heat-treated product is added before the completion of the esterification reaction or transesterification reaction, or if the polycondensation reaction is started under reduced pressure without temporarily holding it under normal pressure, DEC and Insoluble foreign matter increases.

It is preferable to hold the polyester under normal pressure for 5 to 20 minutes at a temperature of 230 to 260°C, since this can extremely reduce the amount of DEC and insoluble foreign substances in the resulting polyester.

In addition, in the present invention, a phosphorus compound can be used as a stabilizer, and it is also preferable to do so. As the phosphorus compound, any phosphorus compound that can be used as a stabilizer for polyester can be used, but phosphoric acid, phosphorous acid, mohaji or triestyl thereof are preferable, and esters having 1 to 6 carbon atoms are preferred. Furkyl esters and furkyl esters are preferred. Also preferred are these alkyl ester laflicols, especially the products obtained by heat treatment in ethylene glycol at 0.degree. The amount of such a phosphorus compound to be used is suitably in the range of 0.001 to 0.5 mol % based on the difunctional carboxylic acid component used as a polyester raw material. Further, it is preferable that the phosphorus compound is added at the time when the first stage reaction is substantially completed. The addition method may be arbitrary, and it may be added as is, or it may be added after being dispersed or dissolved in a glycol, especially the same type of glycol as the glycol used as the polyester raw material.

It is not necessary to adopt special conditions for the ILla synthesis reaction in the present invention. The conditions used are arbitrarily adopted.

Furthermore, in carrying out the present invention, other condensation catalysts may be used in combination without departing from the purpose of the present invention, and optional additives such as colorants and matting agents may be added as necessary. , optical brightener, stabilizer.

Ultraviolet absorber, ether bond inhibitor, dyeing agent.

Flame retardants, antistatic agents, etc. may also be used.

(Function) According to the method for producing modified polyester of the present invention, it is possible to suppress the formation of insoluble foreign substances in the obtained polymer, and as a result, the rise in the internal puncture pressure during melt molding can be suppressed to a low level. As a result, the bag exchange cycle can be significantly extended, and the process condition after the spinning process can be significantly improved.

Moreover, since the DIG component in the resulting modified polymer is small, heat resistance and weather resistance can also be improved.

(Effects of the invention) The modified polyester obtained by the production method of the present invention not only improves productivity, which has been a problem in the past, but also improves the quality of the final product, which allows for good process passability in high-order processing. become.

In particular, when the production method of the present invention is applied to the production of modified polyester by a direct esterification method, the above effects become remarkable.

(Example) Next, the present invention will be explained in further detail by giving examples.

The parts in the examples are it parts, and [η] is the intrinsic viscosity determined from the value measured at 30° C. in orn chlorophenol solvent. The b value and b value representing color tone are values measured using a Hunter-O color difference meter, and the higher the (L-b) value, the better the color tone.

In addition, in the examples, the average degree of polymerization of the direct polymerization method oligomer was calculated from the following formula by measuring the saponification value and acid value of the oligomer.

Average degree of 1 degree Pn However, the saponification value was determined as the number of potassium hydroxide lambda consumed per y of oligomer by saponifying the oligomer by adding an excess alcoholic alkaline solution and back titrating the excess alkali with acid. . The acid value was determined by dissolving the oligomer in pyridine, adjusting it with an alkaline solution, and calculating the titer as the number of potassium hydroxide consumed per y of oligomer.

Mata, spinnability is 40 mesh, 60. '7 Shiyu, filtration area 32ffl puncture using 7 random sand 200y and 0.10m! Using a 24-hole spinneret, spinning was carried out at a spinning temperature of 300° C. and a take-up speed of 1200 m/m, and changes in puncture internal pressure were investigated.

Example-1 A mixture consisting of 100 parts of dimethyl terephthalate (DMT), 70 parts of ethylene glycol, and 0.022 parts of manganese acetate as a transesterification catalyst was heated from 150°C to 240°C for 21D, and methanol was distilled over a period of 4 hours. The transesterification reaction was carried out while the mixture was being discharged. Next, 0.03 part of phosphorous acid as a stabilizer and 0.0 part of a titanium compound as a condensation catalyst were added.
2 parts of titanium dioxide were added thereto, and an ethylene glycol slurry containing 0.3 parts of titanium dioxide as a quenching agent was further added.

The average degree of integration (X) of the resulting transesterification product was 1.8. This transesterification product contains 5-
4.8 parts of sodium sulfoisophthalate bis(p-hydroxyethyl) ester (A) and 0.07 part of sodium acetate trihydrate (Y) were heated in 12 parts of ethylene glycol at 130°C for 60 minutes under normal pressure. After adding the treated product and maintaining it at 240°C for 10 minutes under normal pressure, 1wH
Polycondensation reaction was carried out by heating at 285°C for 4 hours under a reduced pressure of less than 100 g. O, b value 5.4 No modification ytj 'J
Obtained 7 tallates of F-Lentele.

The titanium compound used here was ethylene glycol 2
．． After dissolving 0.8 part of trimellitic anhydride in 5 parts, 0.7 part of tetrabutyl titanate (1 part 2 mol based on trimellitic anhydride) was added dropwise, and the solution was kept at 80°C under normal pressure in air for 60 This is a precipitate obtained by reacting and maturing for 1 minute, then cooling until drying, adding 15 parts of acetone, filtering the precipitate through 45 f paper, and drying at 100° C. for 2 hours.

The average puncture pressure increase for this polymer over 7 days was 1.01v.
The particle size was as small as /g/day, and the spinnability was good.

In addition, Y at this time is 100 mi! 1 mol% (mmo1%;
), and (61-11X) is 41 and (23
3-33X) was 174.

Examples-2 to 11. Comparative Examples-1 to 2 Example-1 except that the metal sulfonate group-containing isophthalic acid compound and the alkali metal compound class 81, the amount added, the heat treatment conditions, and the holding conditions were changed as shown in Table 1. The same procedure as 1 was carried out.

The quality and puncture pressure increase rate of the obtained modified polyester are also listed in Table 1.

In Table 1, in Comparative Examples 1 and 2, the amount of the fulkaline metal compound added was outside the range specified by the present invention, so compared to Examples 2 to 11, the resulting modified polyester was punctured. High pressure rise rate.

Example-12゜teL/7ptR(TA) 86%, x-chiL
/7j Charge the Ris-Reel 3B part into a pressure-resistant autoclave, apply a pressure of 3.0 kg/crx-G, heat from 190°C to 240°C, and carry out the esterification reaction while distilling water for 3 hours. I forced it. Next, 0.04 part of 7th monium dioxide was added as a polycondensation catalyst, and ethylene glyfur slurry containing 0.3 part of titanium dioxide was further added as a matting agent. The average storm degree (X
) was 5.0.

5-sodium sulfoisophthalate bis(p-hydroxyethyl) ester (A) 4
．． 8 parts of sodium acetate trihydrate (yO, 0.014 parts) were heat-treated in 12 parts of ethylene glyfur at 130°C for 60 minutes under normal pressure, and the resulting mixture was heated at 250°C for 10 minutes under normal pressure. After that, under reduced pressure of 1 mjllil or less 2
Heat at 85°C for 3 hours to cause Xa combination reaction, [da]
0.48.

Softening point 255.0℃ 9 colors fJI4L value 75. O, b value 4
．． Modified polyethylene terephthalate No. 8 was obtained. The average back pressure increase for this polymer over 7 days was 1.4 kg/
ad/day, and the spinnability was good.

In addition, Y at this time is 20 ramo1% (vs. TA), (61-11X) is 6, and (233-33X) is 6.
It was 8.

Comparative Example-3 The amount of sodium acetate/trihydrate used was the same as in Example-1.
A polycondensation reaction was carried out in the same manner as in Example 12 except that the amount was 0.07 part. The obtained modified polyethylene terephthalate has a [η) 0.48° softening point 256.0°C 0 color ali L value? 4,5. Although the b value was good at 5.2,
The presence of significant agglomerates of titanium dioxide was observed even when visually observed, and the rate of increase in back pressure was extremely high at 97 cd/day in 15' (fiber breakage occurred frequently and spinnability was extremely poor).

In addition, Y at this time is 99 mmo1% (to TA), (61-11X) is 6 and (233-33X) is 68
Met.

Claims (8)

[Claims] (1) When producing a polyester by subjecting the esterification reaction or transesterification reaction product of a difunctional aromatic carboxylic acid compound and a difunctional glycol to a polycondensation reaction in the presence of a polycondensation catalyst, the esterification reaction Alternatively, a metal sulfonate group-containing isophthalic acid compound represented by the following general formula [I] and an amine compound and/or an alkali metal compound are added to the reaction product obtained by substantially completing the transesterification reaction in ethylene glycol. The amine compound and/or alkali metal compound are added to the heat-treated product in such a manner that the alkali metal compound satisfies the following formula [II], and then the condensation reaction system is temporarily maintained under normal pressure and then under reduced pressure. A method for producing modified polyester characterized by carrying out a polycondensation reaction. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R_1 and R_2 are hydrogen atoms, -C_nH_2
_n_+_1 (n=1 to 4), or -C_mH_2_m
OH (m=2-4), M is Na, Li, K, Ti
, Ca, Zn, Mg, and Zn metal atoms, respectively. ] [II] Formula 61-11X≦Y≦233-33X [In the formula, ...Additional amount of amine compound and/or alkali metal compound [mmol% (to difunctional aromatic carboxylic acid compound)] (2) The metal sulfonate group-containing isophthalic acid compound represented by the general formula [I] is 5-sodium dimethyl sulfoisophthalate, 5-lithium dimethyl sulfoisophthalate, 5-sodium sulfoisophthalate bis(p-hydroxyethyl) ester, or 5-lithium sulfoisophthalic acid bis(p-hydroxyethyl) ester, the method for producing a modified polyester according to claim (1). (3) The method for producing a modified polyester according to claim (1), wherein the amine compound is triethanolamine, tetrabutylammonium hydroxide, tetrabutylammonium chloride, or tetrabutylammonium bromide. (4) The method for producing a modified polyester according to claim (1), wherein the alkali metal compound is sodium acetate or lithium acetate. (5) The method for producing a modified polyester according to claim (1), wherein the polymerization catalyst is a reaction product obtained by reacting titanium tetraalkoxide and trimellitic anhydride in ethylene glycol. (6) The amount of the metal sulfonate group-containing isophthalic acid compound added is 0.5 with respect to the difunctional aromatic carboxylic acid compound.
10 mol % of the modified polyester according to claim (1). (7) Claims (1) to (4) in which the temperature and time of heat treatment of the metal sulfonate group-containing isophthalic acid compound and the amine compound and/or alkali metal compound are 50 to 150°C and 30 to 120 minutes, respectively. ) A method for producing a modified polyester according to any one of the above. (8) The holding temperature and time of the polycondensation reaction system are each 230~
Claim No. (1) which is 260°C and 5 to 20 minutes
Method for producing modified polyester as described in section.