JPS61143426A - Production of modified polyester - Google Patents

Abstract

PURPOSE:To obtain in high productivity a modified polyester readily dyeable with basic dye with reduced foreign substances in the final polymer, by incorporating a specific amount of an aromatic carboxylic acid compound in sulfonic acid compound-copolymerized polyester. CONSTITUTION:An esterification or ester interchange reaction is carried out between. (A) an acid component (e.g., terephthalic acid) and (B) a glycol. Before the completion of the above reaction, (C) 0.5-10mol%, based on the component (A), of a sulfonic acid compound of formula I (R1 and R2 are each H or 1-4C alkyl; M is Na, Li, K, etc.) is brought to copolymerization; and furthermore, at such a pint that a conversion of 70% or higher has been reached, (D) aro matic carboxylic acid of formula II (R3 and R4 are each H, 1-4C alkyl, etc.) and/or formula III (R5 and R6 are each 1-4C alkyl) (e.g., benzaic acid) is added to the system is such an amount as to satisfy the equation IV (A is total mole number for both components (C) and (D); S is mole number for the component (B)) to perform polycondensation, thus obtaining the objective polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) 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) Polyesters, particularly polyesters containing terephthalic acid as a main acid component, have excellent mechanical, physical, and chemical properties, and are therefore widely used in fibers, films, and other molded products.

However, such polyester fibers have insufficient dyeability, and many attempts have been proposed to improve the dyeability. For example, as seen in Japanese Patent Publication No. 34-10497, a method of copolymerizing polyester with a compound containing a metal sulfonate group is known as a preferred method for improving the dyeability with basic dyes.

However, when such a copolyester of a metal sulfonate group-containing compound is produced by a conventional polyester production method, insoluble compounds are likely to be produced in the resulting polymer, and the rate of increase in pack pressure during molding, especially during melt spinning, is high. Become. For this reason, if the spinning pack pressure becomes too high, the spinning process condition and/or the drawing process condition will deteriorate due to an increase in yarn breakage and/or an increase in two fluffs in the drawn yarn breakage, and furthermore, the process in the higher processing process will be impaired. Problems such as deterioration in properties or deterioration in the quality of the final product occur, and it becomes necessary to replace the spinning pack 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 compound, but the resulting modified polyester may not necessarily be satisfactory. The reality is that it cannot be said to represent production.

(Object of the Invention) It is an object of the present invention to provide a method for producing a modified polyester in which the amount of foreign matter in the polymer is significantly reduced.

(Structure) As a result of intensive research aimed at achieving the above object, the present inventors discovered that aromatic carboxylic acid after esterification reaction or transesterification reaction in the production of modified polyester copolymerized with metal sulfonate group-containing compounds. The present invention was achieved based on the discovery that when a specific amount of a compound is added, insoluble foreign substances in the resulting modified polyester are significantly reduced.

That is, in the present invention, when producing a polyester from an aromatic carboxylic acid and/or an ester-forming derivative thereof and a glycol, the general formula (f) So , a sulfonic acid compound represented by M is added, and the reaction rate further increases to 7.
At the time when the concentration is 0% or more and after the addition time of the compound represented by the general formula (1), the following general formula (
This is a method for producing a modified polyester, which comprises adding a compound represented by II) and/or (III) in a manner that satisfies the following formula (IT), and then subjecting the compound to a polycondensation reaction.

General formula (n) General formula (m) R,R.

(rV)Formula %Formula %() The metal sulfonate group-containing compound used in the present invention is represented by the general formula (f).So,M Among the compounds represented by the above general formula (r), preferred are: 5-Sodium sulfoisophthalate dimethyl ester, 5-lithium sulfoisophthalate dimethyl ester, 5-potassium sulfoisophthalate dimethyl ester, 5-sodium sulfoisophthalate bis(p-hydroxyethyl) ester, 5-lithium sulfoisophthalate bis (p-hydroxyethyl) ester and the like.

Among these, 5-sodium sulfoiphthalic acid dimethyl ester is preferred.

Such a compound containing a metal sulfonate group is preferably copolymerized with 0.5 to 10 mol 5 of the aromatic carboxylic acid and/or its ester-forming derivative as a raw material, and has a %kIE mass of 1.0. ~6.0 mol%.

If the metal sulfonate group 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 this, but also the manufacturing cost of the polyester tends to increase.

In addition, in the case of a lower alkyl ester such as dimethyl 5-metal sulfoisophthalate, the timing of addition of the metal sulfonate group compound is before the beginning of the transesterification reaction R, and in the case of a lower alkyl ester such as dimethyl 5-metal sulfoisophthalate. In the case of sugelicol ester, it is preferable to carry out the reaction after the start of the transesterification reaction, or after the start of the esterification reaction and before the end of the transesterification reaction, or before the end of the esterification reaction.

Next, in the present invention, general formula (11) and/or (III
) is added in an amount that satisfies the formula (I) after the metal sulfonate group-containing compound is added and the reaction rate reaches 70% or more. This is necessary to improve the formability of the spinning pack, especially the increase in internal pressure of the spinning pack.

General formula (T1) General formula (m) R R6 (mV) Formula % Formula % () The number of moles of the compound shown is shown respectively. JHere, preferable specific examples of the compound represented by the general formula ([) include benzoic acid, monomethyl terephthalate, P-oxybenzoic acid, P-acetoxybenzoic acid, p-toluic acid, etc. Benzoic acid and P-oxybenzoic acid are preferred.

Preferred specific examples of the compound represented by the general formula (m) include trimellidic acid, hemimellitic acid, trimesic acid, and monomethyl trimellidate.

Dimethyl trimellitic acid and the like can be mentioned, with trimellidic acid and hemimellic acid being particularly preferred.

In the present invention, the compound represented by general formula (II) and the compound represented by general formula (III) may be used in combination.

The compounds represented by formulas (II) and (m) are hereinafter abbreviated as pack internal pressure increase suppressants.

If the ratio (A/S) between the total number of moles of the pack internal pressure increase suppressant (A) and the number of copolymerized moles of the metal sulfonate group-containing compound (S) is less than 0.01, the increase in the pack internal pressure may be sufficiently suppressed. If it exceeds 1.0, the progress of the polycondensation reaction will be delayed or the physical properties of the resulting modified polyester will be impaired.

Also, the timing of adding this pack internal pressure increase suppressant is as follows:
Any time after the metal sulfonate group-containing compound is added as long as the reaction rate is 70% or more is acceptable, but a particularly preferable time is at the beginning of the polycondensation reaction until the intrinsic viscosity [η] reaches 0.2. It was before.

However, the intrinsic viscosity [η] mentioned here is determined from the value measured at 30° C. in an orthochlorophenol solvent.

At the time of this addition, a pre-mixed mixture of the pack internal pressure increase suppressant and the glycol used as the polyester raw material may be added.

In this way, after adding the pack internal pressure increase inhibitor, it is preferable to react under normal pressure at a temperature of 220 ° C. or higher for at least 4110 minutes, because the added pack internal pressure increase inhibitor can be sufficiently reacted. Furthermore, Ki-ni IIA
The aromatic carboxylic acid (hereinafter sometimes referred to as difunctional carboxylic acid) used as a raw material for polyester is mainly terephthalic acid, and its ester-forming derivatives include lower dialkyl having 1 to 4 carbon atoms. Esters, 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 inphthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, and β-
Examples include difunctional aromatic carboxylic acids such as hydroxyethoxybenzoic acid.

The main target glycol is ethylene glycol. In addition, other glycols such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol, and aliphatic glycols such as cyclohexane-1,4-silotyrol may be used in place of ethylene glycol, and among these, tetramethylene glycol is preferred. . Furthermore, some of the main glycols may be replaced with other glycol or diol compounds.

Any method can be used to produce polyester from such difunctional carboxylic acid and/or its ester-forming derivative and glycol, but for polyethylene terephthalate, direct esterification of terephthalic acid and ethylene glycol is used. a first step reaction of reacting or transesterifying a lower alkyl ester such as dimethyl terephthalate with ethylene glycol to produce a glycol ester of terephthalic acid and/or a low polymer thereof; Generally, a method is employed in which the product is produced by subjecting the product to heat under reduced pressure to cause a polycondensation reaction.

Any catalyst can be used in these reactions as necessary. Among these, when employing the transesterification method, calcium compounds, manganese compounds, magnesium compounds, zinc compounds, cobalt compounds, etc. are preferred as transesterification catalysts, and these may be used alone or in combination of two or more. The amount used is o, o i ~ 0.1 with respect to the difunctional carboxylic acid component used as a polyester raw material.
So% is preferred. Further, as the polycondensation catalyst, antimony compounds, titanium compounds, and germanium compounds are preferable, and organic titanium compounds are particularly preferable. These may also be used alone or in combination, and the amount used is preferably 0.003 to 0.1 mol % based on the bifunctional carboxylic acid component.

Also, in the present invention, phosphorus compounds can be used as stabilizers, and this is also preferred. As the phosphorus compound, any phosphorus compound that can be used as a stabilizer for polyester can be used, but among these, tortoise phosphoric acid, phosphorous acid, and mono-, di-, or tri-esters thereof are preferable. The alkyl ester and phenyl ester of No. 6 are preferred. Also preferred are products obtained by heat treating these alkyl esters in glycols, especially ethylene glycol. The amount of the phosphorus compound used is 0.001 to 0.5 with respect to the difunctional carboxylic acid component used as the polyester raw material.
A range of mole % is suitable. Further, the timing of addition of the phosphorus compound is preferably when the reaction in the first stage 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 the same type of glycol as the glycol used as the polyester raw material.

The polycondensation reaction in the present invention does not require special conditions, and is employed when polycondensing the reaction product of a difunctional carboxylic acid and/or its ester-forming derivative with glycol to form a polyester. conditions are arbitrarily adopted.

Furthermore, in carrying out the present invention, other polycondensation catalysts may be used in combination without departing from the purpose of the present invention, and optional additives such as colorants, matting agents, Fluorescent brightener, stabilizer, ultraviolet absorber, ether bond inhibitor,
Easy dyeing north side, flame retardant, antistatic agent, etc. may be used.

(Function) According to the method for producing a modified polyester having the structure of the present invention, it is possible to suppress the formation of insoluble compounds in the obtained polymer, and as a result, it is possible to suppress the increase in pack internal pressure during melt molding. Therefore, the pack exchange cycle can be significantly extended, and the cutting condition after the spinning process can be significantly 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
The quality of the final product can also be improved, so the effects of this process are extremely large, such as improved passability in high-order processing.

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

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

In addition, the spinnability was determined using 40 mesh, 60 mesh, a pack with a filtration area of 32 cd using Morundum Sand 200F, and a 0-10 mφ, 24-hole spinneret at a spinning temperature of 300"C and a take-up speed of 1200111/l. !I
The fibers were spun using I and the changes in pack internal pressure were investigated.

Example-1 100 parts of dimethyl terephthalate, 7 parts of ethylene glycol
A mixture of 0 parts, 5 parts of dimethyl 5-sodium isophthalate, and 0.022 parts of manganese acetate and 0.07 parts of sodium acetate as transesterification catalysts was heated at 150°C for 2 hours.
The mixture was heated to 40° C. and transesterification was carried out over a period of 4 hours while methanol was distilled off. Next, 0.03 part of phosphorous acid as a stabilizer and 0.0 part of a titanium compound as a polycondensation catalyst were added.
．． 0.02 parts of titanium dioxide was added as a matting agent.
An ethylene glycol slurry containing 3 parts was added. Then, add 0.2 parts of P-oxybenzoic acid (A/S=0.0
9) was added and reacted for 10 minutes or more at an internal temperature of 220°C or higher, and then heated at 285°C for 4 hours under reduced pressure of 1111 IHg or lower to cause a polycondensation reaction, [η) 0.48, softening point 256.8 °C1 color tone value 69.3. A modified polyethylene terephthalate with a b value of 5.8 was obtained.

The titanium compound used here was ethylene glycol 2
．． After dissolving 0.8 parts of trimellidic anhydride in 5 parts of the solution, 0.7 parts of tetrabutyl titanate (1 part 2 moles relative to trimellitic anhydride) was added dropwise, and the mixture was kept at 80°C under normal pressure in air for 60 minutes. React and mature for a minute, then cool to room temperature,
This is a precipitate obtained by adding 15 parts of acetone, passing the precipitate through n5F1 paper, and drying it at 100° C. for 2 hours.

The average pack pressure increase for this polymer over 7 days is 1.9kl.
P77 FII/day was small, and the spinnability was good.

Examples 2 to 7 Polymers obtained by polycondensation reaction in the same manner as in Example 1, except that the amount of P-oxybenzoic acid used in Example 1 was varied as shown in Table 1. The quality and average pack pressure increase over 7 days are also shown in Table 1.

Example-8 A polymer obtained by polycondensation reaction in the same manner as in Example-1 except that benzoic acid was added instead of P-oxybenzoic acid used in Example-1 was [η) 0 .48,
Softening point: 256.7℃ 1 Color value: 68.9. The b value was 6.1.

The 7-day pack pressure increase for this polymer averages 1.9 k
The spinnability was small, g/cd/day, and the spinnability was good.

Comparative Example-1 [η] of the polymer obtained by polycondensation reaction in the same manner as in Example-1 except that the P-oxybenzoic acid added in Example-1 was not used was 0.4B.

The softening point is 256.7°C and the color tone value is 69.2. b value 5.9
Met.

The 7-day pack pressure increase for this polymer averaged 5.11
The spinnability was as large as qF/i/day, and the spinnability was extremely poor.

Example-9 Polymer obtained by polycondensation reaction in the same manner as in Example-1 except that 0.04 part of antimony Mikumaide was used as a polymerization catalyst instead of the titanium compound used in Example-1. is [η) 0.48.

Softening point 256.7℃ 1 color LL value 69.2. b value 5.7
Met.

The 7-day pack pressure increase for polymers with averages 2.0 k
The tt/cd was as small as 7 days, and the spinnability was good.

Comparative Example-2 A polymer obtained by polycondensation reaction in the same manner as in Example-1 except that the P-oxybenzoic acid added in Example-1 was added simultaneously with dimethyl 5-sodium isophthalate was
) 0.48, softening point 255.2℃9 color tone value 68
．． 6. The b value was 6.2.

The 7-day pack pressure increase for this polymer averaged 4.2k
It was as large as p/cIi/day, and the spinnability was poor.

Comparative Example-3 A polymer obtained by polycondensation reaction in the same manner as in Example-1 except that the P-oxybenzoic acid added in Example 1 was added at a transesterification reaction rate of 65% was ) 0.4
8, Softening point 255.9℃ 1 Color tone value 68.7. b value 6
．． It was 0.

The 7-day pack pressure rise for this polymer is the average a, sk
The spinnability was as large as p/cd/day, and the spinnability was poor.

Example-10 Polycondensation reaction was carried out in the same manner as in Example-1 except that 0.2 part of trimellidic acid (A/S = 0.06) was added in place of P-oxybenzoic acid. The obtained polymer had a [η) of 0.48. Softening point 256.7℃ 1 Color value 69.1. The b value was 6.0.

The 7-day pack pressure increase for this polymer averaged 1, s k
It was small at g/cd/day, and the spinning properties were good.

Examples-11 to 16 Example-1O except that the amount of Torino 17) acid used in Example-10 was varied as described in Table 1.
Table 1 also shows the quality of the polymer obtained by the polycondensation reaction in the same manner as above and the average increase in the nozzle pressure over 7 days.

Example 17 A polymer obtained by polycondensation reaction in the same manner as in Example 10 except that hemimellitic acid was added in place of the trimellidic acid used in Example 10 had [η) 0. 48
, Softening point 256.1°C 9 Color tone value 68.8. b value 6.
It was 0.

The average 7-day pack pressure increase for this polymer is 1.9 k
The spinnability was as small as 1/cd 7 days, and the spinnability was good.

Example 18 A polycondensation reaction product was obtained in the same manner as in Example 10, except that 0.04 part of antiseptane trioxide was used as a polymerization catalyst instead of the titanium compound used in Example 10. [η] of the polymer was 0.48. Softening point 256.7℃1
The color tone value was 69.0° and the b value was 5.9.

The average 7-day pack pressure increase for this polymer is 2.1 k
The p/cd was as small as 1 day, and the spinnability was good.

Comparative Example-4 Example-4 except that the trimellidic acid added in Example-10 was added simultaneously with dimethyl 5-sodium isophthalate.
The polymer obtained by polycondensation reaction in the same manner as in 10 is
[η) 0.48, softening point 255.5℃ 1 color tone value 6
8.5. The b value was 6.3.

The 7-day pack pressure rise of the polymer with average, a, s
It was as large as lv/cd/day, and the spinnability was poor.

Comparative Example-5 A polymer obtained by polycondensation reaction in the same manner as in Example-10 except that the trimellidic acid added in Example-10 was added at a transesterification reaction rate of 65% had a (η) of 0. 4
8, Softening point 256.0°C.

Color tone value 68.6. The b value was 6.1.

The 7-day pack pressure increase for this polymer averaged 3.9
kg/d7 days, which was large, and the spinnability was poor.

Claims (6)

[Claims] (1) When producing polyester from aromatic carboxylic acid and/or its ester-forming derivative and glycol, the general formula (I) ▲mathematical formula, chemical formula, There are tables, etc. ▼・・・・・・・・・
(I) [In the formula, R_1 and R_2 are hydrogen atoms or carbon atoms with 1
-4 alkyl group, M is Na, Li, K, Ti, Ca
, Zn, Mg, and Mn metal atoms. ] A sulfonic acid compound represented by is added, and the reaction rate further increases to 7.
At the point when the concentration is 0% or more and after the addition time of the compound represented by general formula (I), the following general formula (
The compound represented by II) and/or (III) below (IV
) A method for producing a modified polyester, which comprises adding the modified polyester in a manner that satisfies the formula and then subjecting it to a polycondensation reaction. General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
(II) [In the formula, R_3 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R_4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a carboxyl group, an oxy group, an acetoxy group, or a derivative thereof. . ] General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
(III) In the formula, R_5 and R_6 are alkyl groups having 1 to 4 carbon atoms,
Indicates a carboxyl group, oxy group, acetoxy group, or a derivative thereof. (IV) Formula 0.01≦A/S≦1.0 (IV) A
represents the total number of moles of the compound represented by the general formula (II) and/or (III), and S represents the number of moles of the compound represented by the general formula (I). (2) The method for producing a modified polyester according to claim (1), wherein the compound represented by general formula (I) is dimethyl 5-sodium sulfoisophthalate. (3) The compound represented by general formula (I) is dimethyl 5-lithium sulfoisophthalate.
1) Method for producing modified polyester as described in section 1). (4) Claim No. 1 in which the amount of the compound represented by general formula (I) added is 0.5 to 10 mol% based on the aromatic carboxylic acid and/or its ester-forming derivative.
) or (2), the method for producing a modified polyester. (5) The method for producing a modified polyester according to claim (1), wherein the compound represented by general formula (II) is terephthalic acid. (6) The method for producing a modified polyester according to claim (1), wherein the compound represented by general formula (III) is trimellitic acid.