JPH09316184A - Production of modified polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a process for producing a modified polyester whereby the formation of impurities in polymn. step is greatly inhibited and a modified polyester which can be spun with a small pressure rise in pack section is obtd. by adding a specific phosphorus compd. in producing a polyester by the copolymn. using sulfoisophthalic acid as a comonomer. SOLUTION: 0.01-1wt.% at least one phosphorus compd. selected from among compds. represented by formulas I, II, and III (wherein X1 to X7 and Y1 to Y3 are each H or a 1-10C monovalent org. group of which an oxygen atom is not directly bonded to a phosphorus atom; and A is a 1-10C divalent org. group) is added in producing a copolyester which contains 0.5-10mol% (based on the total carboxylic acid units) units derived from a metal-sulfonate-contg. ester-forming component and contains at least 80mol% ethylene terephthalate units. Pref, the polyester is produced by using 3-10mol% adipic acid in addition to ethylene terephthalate and the metal-sulfonate-contg. ester-forming component.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a modified polyester fiber obtained by copolymerizing a metal sulfonate-containing ester-forming component. More specifically, there is little generation of foreign substances that are clogged with time in the filtration section of the polymer melt during production (hereinafter referred to as the pack), and the pressure in the pack section during production is stable and stable. The present invention relates to a method for producing a modified polyester, which can be produced and can reduce the causes of quality deterioration such as fluff and yield reduction such as yarn breakage by enhancing filtration.

[0002]

2. Description of the Related Art Cationic dye dyeable polyesters obtained by copolymerizing a metal sulfonate-containing ester component typified by 5-sodium sulfoisophthalic acid have been widely known as a dyeing seat for cationic dyes (Japanese Patent Publication Sho-34).
-10497). However, when spinning a polyester obtained by copolymerizing a metal sulfonate-containing ester component, there is a phenomenon in which foreign matter is clogged in the filter for filtering the melt and the pressure in the pack portion increases with time. A yarn spun under such a high pack pressure lacks uniformity such as fineness and the like, and in an extreme case, fluff or yarn breakage occurs. Furthermore, if this state is left unattended, the pressure in the pack portion will suddenly rise at some point, and there will be a situation in which the spinning must be interrupted before the regular replacement of the pack.

A polyester obtained by copolymerizing a metal sulfonate-containing ester component occupies an extremely important position in the fiber industry as a raw material for a cationic dye-dyeable polyester fiber, in terms of the sharpness of the fiber or the compounding with other materials. Therefore, a method for producing a high-quality cationic dyeable polyester capable of drastically reducing the generation of foreign substances in the spinning process and enhancing filtration in order to industrially produce a stable product is desired.

On the other hand, of course, there have been conventionally disclosed some countermeasure techniques for foreign matters in the pack. However, there is virtually no radical solution. For example, decrease the copolymerization ratio of the metal sulfonate-containing ester component that is the causative agent of foreign substances (Japanese Patent Publication No.
No. 26 gazette), but this is not desirable because the number of dyeing seats themselves is reduced. Although the countermeasure technique using a modified titanium catalyst is effective in suppressing foreign matters, it has a problem in that the catalyst is complicated to synthesize and the finally obtained polyester chip is colored yellow (JP-A-61- 57618, Japanese Patent Laid-Open No. 61-14342.
6, JP-A-62-6022, JP-A-63-
No. 6022).

[0005] In addition, the technique of adding bis (oxyethyl) 5-sodium sulfoisophthalate instead of dimethyl 5-sodium sulfoisophthalate increases the cost of raw materials and does not have a remarkable effect of suppressing foreign substances. JP-A-52-63295). Addition of lithium acetate or further optimization of the quantitative ratio with dimethyl 5-sodium sulfoisophthalate (JP-A-51-84893, JP-A-58-138731) can certainly suppress the formation of foreign matter. However, the suppression effect is not satisfactory. The countermeasure technology for changing the metal portion of 5-sodium sulfoisophthalic acid dimethyl ester from commonly used sodium to lithium, potassium, etc. is difficult to obtain a raw material with high purity, and the effect of suppressing the foreign matter is not remarkable ( For example, JP-A-59-98130
Issue).

[0006] The suppression effect of the countermeasure technique such as using a heat reaction treatment of antimony trioxide and oxybenzoic acid used as a polycondensation catalyst is not remarkable (JP-A-62-174226). There is a technique in which a foreign substance is dispersed by adding polyethylene glycol during the polymerization, and the effect of suppressing the foreign substance is significant (for example, JP-A-63-48353), but this technique is a polyethylene glycol copolymer polyester. Since it becomes a polymer, the dyeing fastness of the fiber is changed and cannot be applied as a countermeasure technology for existing brands.

As described above, the polyester in which sulfoisophthalic acid is copolymerized, which is industrially excellent in spinnability, has not yet been obtained.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is that the increase in pack pressure with time during spinning is extremely low, and as a result, the pack replacement cycle is extended, productivity is improved, and filtration is strengthened more than before. It is possible to provide a method for producing a modified polyester having a metal sulfonate group, which is capable of providing a high quality fiber with less fluff and yarn breakage.

[0009]

As a result of intensive studies for solving the above-mentioned problems, the present inventors have isolated and identified a foreign substance produced when a polyester copolymerized with sulfoisophthalic acid is used, and identified the formation thereof. The mechanism was clarified. As a result, by adding a phosphorus compound having a certain specific structure in the polymerization process, the production of foreign substances is significantly suppressed, the increase in pack pressure is very small, and the spinning stability is the same as in ordinary polyethylene terephthalate. The inventors have found the possibility of obtaining a polymer and arrived at the present invention.

That is, the first aspect of the present invention is that the metal sulfonate-containing ester-forming component is 0.5 with respect to all carboxylic acids.
In the case of polymerizing a copolymerized polyester in which 10 mol% is copolymerized and 80 mol% or more of the constituent units are composed of ethylene terephthalate units, the general formula (1),
(2) A method for producing a modified polyester, which comprises adding 0.01 to 1% by weight of at least one phosphorus compound represented by (3),

[0011]

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[0012]

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[0013]

[Chemical 6]

(Here, Xn (n is an integer of 1 to 7) and Yn (n is an integer of 1 to 3) are hydrogen atoms or oxygen atoms in which an oxygen atom is not directly bonded to a phosphorus atom, or a carbon number of 1 to 1).
10 represents a monovalent organic group, and A represents a divalent organic group having 1 to 10 carbon atoms. According to the second aspect of the present invention, the copolyester has a metal sulfonate-containing ester forming component of 0.5 with respect to all carboxylic acids.
3. The modified polyester according to claim 2, wherein 10 to 10 mol% of the adipic acid component is copolymerized to 3 to 10 mol%, and 80 mol% or more of the constituent units are composed of ethylene terephthalate units. Is a manufacturing method.

Hereinafter, the present invention will be described in detail. In the present invention, examples of the structure corresponding to the metal sulfonate-containing ester forming component include 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, 5-lithium sulfoisophthalic acid and sodium sulfonaphthalenedicarboxylic acid. Of these,
5-sodium sulfoisophthalic acid has good spinnability,
It is preferable from the viewpoint of good color development by the cationic dye.
The metal sulfonate-containing ester forming component may be used alone or in combination of two or more.

The metal sulfonate-containing ester-forming component should be copolymerized from 0.5 to 10 mol% based on the total carboxylic acid. When it is less than 0.5 mol%, the degree of color development to a cationic dye is low, and when it is more than 10 mol%, spinnability, coloration and hydrolysis resistance are remarkably deteriorated. Considering good spinnability, dyeability and thermal stability, it is preferably 0.5 to 4 mol%, particularly preferably 0.
It is 8 to 3 mol%.

In the present invention, in order to suppress the generation of foreign matter that causes an increase in pack pressure, at least one phosphorus compound represented by the general formulas (1), (2) and (3) is used in the polymerization process. It is necessary to add 0.01 to 1% by weight.

[0018]

[Chemical 7]

[0019]

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[0020]

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Here, Xn (n is an integer from 1 to 7),
Yn (n is an integer of 1 to 3) each represents a hydrogen atom in which an oxygen atom is not directly connected to a phosphorus atom or a monovalent organic group having 1 to 10 carbon atoms, and A is 2 having 1 to 10 carbon atoms. Indicates a valent organic group. Specific examples of Xn (n is an integer of 1 to 7) include hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group,
t-butyl group, n-pentyl group, n-hexyl group, n-
Hydrocarbon groups such as heptyl group, n-octyl group, n-nonyl group, n-decyl group, phenyl group and benzyl group, or some or all of the hydrogen atoms of these hydrocarbon groups have more than 10 carbon atoms. -OH, -COOR,-
R, -OR, -F, -Cl, -Br, -NH2, -NH
It may be substituted with R (wherein R is a methyl group,
A hydrocarbon group represented by an ethyl group, an n-propyl group, an n-butyl group, a t-butyl group, a phenyl group, or a group in which some or all of the hydrogen atoms are -OH, -Cl, -Br, etc. It may be substituted. ).

Specific examples of Yn (n is an integer from 1 to 3) include hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t.
-Butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, phenyl group, benzyl group and other hydrocarbon groups, or hydrocarbons thereof In the range where some or all of the hydrogen atoms of the group do not exceed 10 carbon atoms, -OH, -COOR,-
R, -OR, -F, -Cl, -Br, -NH2, -NH
It may be substituted with R (wherein R is a methyl group,
A hydrocarbon group represented by an ethyl group, an n-propyl group, an n-butyl group, a t-butyl group, a phenyl group, or a group in which some or all of the hydrogen atoms are -OH, -Cl, -Br, etc. It may be substituted. ).

A represents a divalent organic group having 1 to 10 carbon atoms, and specific examples thereof include methylene group, ethylene group,
Hydrocarbon groups such as propylene group, butylene group, pentylene group, hexylene group, octylene group, nonylene group, decylene group, phenylene group, or some or all of the hydrogen atoms of these hydrocarbon groups have 10 carbon atoms. Within the range not exceeding, -OH, -COOR, -OCOR, -R, -O
R, -F, -Cl, -Br, -NH 2, optionally substituted with -NHR (wherein, R represents a methyl group, an ethyl group, n- propyl group, a hydrocarbon typified by phenyl group Group is shown).

General formulas (1), (2), used in the present invention,
The phosphorus compound represented by (3) has the above Xn (n is 1 to
All combinations of Yn (n is an integer from 1 to 3) can be used. The phosphorus compounds represented by the general formulas (1), (2) and (3) used in the present invention may be used alone or in combination of two or more kinds. However, when a phosphorus compound other than the phosphorus compounds represented by the general formulas (1), (2), and (3) shown in the present invention, such as trimethyl phosphate generally used in the polymerization of polyester, is allowed to coexist, the present invention is The effect may be significantly impaired, and the general formula (1) shown in the present invention,
It is recommended to use only the phosphorus compounds shown in (2) and (3). The amount used is 0.01 to 1% by weight based on the amount of the polymer obtained. When the amount is less than 0.01% by weight, the effect of suppressing the generation of foreign matter is small, and when the amount is more than 1% by weight, the polycondensation reaction is adversely affected, and more than the amount necessary for suppressing the foreign matter during spinning. The stabilizer itself deteriorates to become a foreign substance and increase the pack pressure. The amount of the phosphorus-based stabilizer is preferably 0.01 to 0.5% by weight, and particularly preferably 0.15% by weight in order to obtain a polymer having no problem in polymerization while sufficiently suppressing the generation of foreign matter.
~ 0.3% by weight.

The modified polyester of the present invention may contain a constituent unit other than ethylene terephthalate and a metal sulfonate-containing ester-forming component. Specifically, aromatic dicarboxylic acids such as isophthalic acid, naphthalene-2,6-dicarboxylic acid, etc. Acids, adipic acid, sebacic acid, aliphatic dicarboxylic acids such as dodecanedioic acid, P-oxybenzoic acid,
Oxycarboxylic acids such as P-β-oxyethoxybenzoic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,4-butanediol, neopentyl glycol, diethylene glycol, triethylene glycol,
Aliphatic diol such as tetraethylene glycol, alicyclic diol such as cyclohexanedimethanol, polyethylene glycol, random copolymer of polyoxyethylene and polyoxypropylene, polytetramethylene glycol, random of polytetramethylene glycol and neopentyl glycol Known copolymerization components such as copolymers can be used. In particular, when an aliphatic dicarboxylic acid is used, it is possible to dye at a normal pressure of 100 ° C. or lower. For this purpose, it is highly desirable to use adipic acid. In this case, the copolymerization ratio is 3 to 10 mol%, preferably 4 to 8 mol%.

The modified polyester of the present invention can be produced by a conventional method. That is, dimethyl terephthalate or the general formula (1) at any stage during the production of a polyester obtained by copolymerizing terephthalic acid and ethylene glycol with 5-sodium sulfoisophthalic acid
The phosphorus compounds represented by (2) and (3) may be added. It may be added at any time until the completion of polymerization,
The whole amount may be added at once, or may be added little by little in several times.

In the present invention, a matting agent, an anti-coloring agent,
It may contain additives such as an antioxidant, an ultraviolet absorber, a fluorescent whitening agent and a pigment.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to examples. The measured values in the examples were measured by the following method. (1) Reduced viscosity of polymer (ηsp / c) Using o-chlorophenol as a solvent, the polymer concentration was 1.
It was measured at 0% and 35 ° C. (2) Fluff ratio Stretched yarn wound in a pan state (5 kg per pirn)
The fluff of the amount of wrapping) was visually inspected to see if the fluff was on the surface or side of the pan, and the fluff rate (%) was determined according to the following formula.

Fluff ratio (%) = {(number of fluffs not found-number of fluff found pans) / (total number of fluffs)} × 100

[0030]

Example 1 100 parts of dimethyl terephthalate, 75 parts of ethylene glycol, dimethyl 5-sodium sulfoisophthalate (hereinafter abbreviated as SIPM) 3.3 parts (copolymerization ratio corresponds to 2.3 mol%), Lithium acetate dihydrate 0.07 part, manganese acetate 4 as transesterification catalyst
0.048 parts of a water salt was charged, gradually heated from 150 ° C. to 240 ° C., and transesterification was carried out while distilling methanol for 3 hours.

Then, as a phosphorus compound, phenylphosphonate
0.17 parts of dimethyl acid salt and triacid as polycondensation catalyst
Add 0.05 parts antimony oxide and prepolymerize over 50 minutes
Was done. The pressure is gradually reduced, and finally 0.5
Conduct polycondensation reaction at 280 ° C. for 2 hours and 40 minutes with Torr,
A modified polyester having ηsp / c = 0.56 was obtained. Next
Then, the above polymer was heated at 150 ° C. for 24 hours under a nitrogen stream.
After drying, it was spun through a pack shown below. sand
That's 50 and 80 mesh Moran in the pack.
Under 200 g of the mixture of dam sand, 8 from the bottom
0 mesh wire mesh, 150 mesh wire mesh, 30 μm
Sintered filter, 300 mesh wire mesh, 150 mesh
Filtration area 44 cm^TwoPack and 0.
A 25-mmφ 24-hole round mouthpiece was provided. Discharge rate 31g
/ Min, spinning temperature of 285 ° C for 1 week, 1500 / min
Melt spinning was performed at the spinning speed. Increase in spinning pack pressure at that time
Is 35 kg / cm in one week^TwoAnd on the pressure in question
There was no rise. 800 m / min of the obtained undrawn yarn
Was drawn at a speed of 2.6 times to prepare a drawn yarn. Obtained
The fluff rate was 0.8%, which was extremely good. By the way,
When polyethylene terephthalate is similarly spun,
The pressure rise is 33 kg / cm in one week ^TwoAnd fluff
The rate was 0.8%.

[0032]

Examples 2 to 10 The structures and addition rates of phosphorus compounds, the copolymerization ratios of dimethyl 5-sodium sulfoisophthalate, dimethyl adipate (hereinafter abbreviated as DMA) and the like are shown in Table 1 from the conditions of Example 1. The experiment was repeated under the same conditions as in Example 1 except for the conditions shown. Table 1 shows the results.

In all cases, the increase in pack pressure was small and the spinnability was extremely good. When DMA was copolymerized, it was charged with dimethyl terephthalate at the beginning of the polymerization.

[0034]

Example 11 The same experiment as in Example 1 was repeated except that 0.1% by weight of a 1: 1 mixture of dimethyl phenylphosphonate and dimethyl methylphosphonate was added. The increase in pack pressure was 30 kg / cm ² in one week, and the fluff ratio was 0.2%, which was good.

[0035]

Comparative Example 1 Instead of dimethyl phenylphosphonate,
The same experiment as in Example 1 was repeated except that 0.17% by weight of trimethyl phosphate was added. In this case, the pack pressure increased from the initial pressure to 150 kg / cm ² on the second day of spinning, and the spinning was stopped. A drawn yarn was prepared, and its fluff rate was determined. As a result, it was 3.5%, and the drawn yarn had many fluff.

[0036]

[Table 1]

[0037]

In the method for producing a copolyester of the present invention, the addition of a specific amount of a phosphorus compound having a specific structure during the polymerization significantly suppresses the generation of foreign matter during the polymerization, resulting in the spinning process. Since the increase in pressure in the pack part and the yarn breakage are improved, a yarn with less fluff is obtained as compared with the conventional one, the post-process passability such as false twisting is also improved, and there is an effect that the quality is comprehensively improved.

Claims (2)

[Claims] 1. A metal sulfonate-containing ester-forming component is copolymerized in an amount of 0.5 to 10 mol% with respect to all carboxylic acids,
Further, when polymerizing the copolyester in which 80 mol% or more of the constituent units are composed of ethylene terephthalate units, at least one of the phosphorus compounds represented by the general formulas (1), (2) and (3) is 0.01 A method for producing a modified polyester, which comprises adding 1 to 1% by weight. Embedded image Embedded image Embedded image (Here, Xn (n is an integer from 1 to 7) and Yn (n is an integer from 1 to 3) are each a hydrogen atom in which an oxygen atom is not directly connected to a phosphorus atom or a monovalent one having 1 to 10 carbon atoms. Represents an organic group, and A represents a divalent organic group having 1 to 10 carbon atoms.) 2. The copolyester has a metal sulfonate-containing ester-forming component of 0.5 to all carboxylic acids.
The modified polyester according to claim 1, wherein 10 mol% and an adipic acid component are copolymerized in an amount of 3 to 10 mol% and 80 mol% or more of the constituent units are composed of ethylene terephthalate units. Production method.