JP4639478B2 - Method for producing modified polyester - Google Patents

Description

表１から明らかなように、本発明による実施例は、いずれも酸化チタン凝集塊およびＤＥＧの副生が少なく、濾圧上昇が遅いのに対して、比較例１、２は酸化チタン凝集塊が多数形成し濾圧上昇が早く、比較例３、４はＤＥＧの副生が多く、さらにＳＩ成分による不溶性異物が形成し濾圧上昇が早かった。
【００３０】
【発明の効果】
本発明の実施により、直重法オリゴマーを用いて、酸化チタン凝集塊が少なくジエチレングリコールの副生が少ないスルホン酸塩基を有するイソフタル酸成分を共重合した改質ポリエステルを製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a modified polyester containing titanium oxide obtained by copolymerizing an isophthalic acid component having a sulfonate group.
[0002]
[Prior art]
Polyester, particularly polyethylene terephthalate, is widely used for fibers, films, industrial materials, and the like because of its excellent mechanical and chemical properties, but it cannot be said that dyeability is necessarily good for clothing fibers. Moreover, since it is dye | stained by a disperse dye, only limited dye can be used and it has the faults, such as inferior | clearness of dyed goods.
[0003]
Conventionally, in order to make up for such drawbacks, as shown in Japanese Patent Publication No. 34-10497, an isophthalic acid component having a sulfonate group in the form of a metal salt (hereinafter referred to as SI component) is copolymerized. A method for producing a cationic dye dyeable modified polyester (hereinafter referred to as a modified polyester) is known.
[0004]
However, in the case of producing a modified polyester containing titanium oxide using a direct heavy oligomer that uses terephthalic acid and ethylene glycol (hereinafter referred to as EG) as main raw materials, the SI component and the direct heavy oligomer In addition to the poor compatibility, the affinity between the SI component and titanium oxide is good, so that titanium oxide aggregates are formed, resulting in problems such as a rapid increase in filtration pressure and frequent yarn breakage in the yarn production process. Furthermore, since the SI component is usually added as an EG solution, the ratio of EG in the reaction system is increased, and a large amount of diethylene glycol (hereinafter referred to as DEG) is by-produced during the esterification reaction and polycondensation reaction. There arises a problem that the mechanical properties, heat resistance, and light resistance of the resin deteriorate.
[0005]
As a method for suppressing the formation of titanium oxide agglomerates and the by-production of DEG, for example, JP-A-56-106922 discloses a dialkyl ester of isophthalic acid having a sulfonate group (hereinafter referred to as SIDA) and EG. A method of adding an SI component having a transesterification rate of 40 to 74% produced by a transesterification reaction to a direct weight oligomer, and JP-A-3-227318 discloses that the transesterification rate is 5 to 40%. A method of adding SI component to a direct weight oligomer, and further, JP-A-54-94598 discloses di-2-hydroxyethyl ester of isophthalic acid having SIDA and a sulfonate group (hereinafter referred to as SIHE). Although a method of adding a specific SI component to a direct heavy oligomer, such as a method of mixing and adding to the direct heavy oligomer, has been proposed. Byproduct effect of suppressing formation inhibiting effect and DEG in either method titanium oxide agglomerates is not sufficient.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to produce a modified polyester obtained by copolymerizing a titanium oxide aggregate and an isophthalic acid component having a sulfonate group with little by-product of diethylene glycol by using a direct polymerization oligomer.
[0007]
[Means for Solving the Problems]
The above-mentioned problem is that when producing a modified polyester obtained by copolymerizing an isophthalic acid component having a sulfonate group using a direct heavy oligomer mainly composed of terephthalic acid and ethylene glycol, an isophthalic acid component having a sulfonate group is produced . An isophthalic acid component having a sulfonate group having a transesterification reaction rate of 50 to 90% from a dialkyl ester and ethylene glycol is added to a direct heavy oligomer as a 50 to 150 ° C. ethylene glycol solution, and then titanium oxide is added. This can be solved by polycondensation.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0009]
The modified polyester in the present invention is ethylene isophthalate having main constituent units of ethylene terephthalate and sulfonate group, but dicarboxylic acid components such as isophthalic acid and naphthalene-2,6-dicarboxylic acid, propylene glycol, 1,4 -Copolymerization components already known, such as diol components such as butanediol, can be used.
[0010]
When the SI component is added, the esterification reaction rate of terephthalic acid and EG, which is a direct oligomer, is preferably 90% or more.
[0011]
Examples of the SI component used in the present invention include SIHE, SIDA, and mono-2-hydroxyethyl-monoalkyl ester of isophthalic acid having a sulfonate group (hereinafter referred to as SIHA). Specific examples of SIHE include sodium 3,5-di (carbo-2-hydroxyethoxy) benzenesulfonate and lithium 3,5-di (carbo-2-hydroxyethoxy) benzenesulfonate. Specific examples of SIDA Examples include dimethyl 5-sodium sulfoisophthalate and dimethyl 5-lithium sulfoisophthalate, and specific examples of SIHA include 3- (carbo-2-hydroxyethoxy) -5- (carbomethoxy) benzenesulfonic acid. Examples include sodium and lithium 3- (carbo-2-hydroxyethoxy) -5- (carbomethoxy) benzenesulfonate. The addition amount of the SI component is preferably 0.5 to 20% by weight with respect to the modified polyester.
[0012]
These are alone or can be used combined mixed. Moreover, you may use SI component manufactured by transesterifying SIDA, SIHA, and EG . Anti応率is 50-90%, and more preferably because it suppressed uses the formation of titanium oxide agglomerates 60 to 80% of the SI components. Here, the reaction rate represents the ratio of the EG group in the SI component. If the reaction rate is 0%, SIDA alone means that the reaction rate is 100%, and SIHE alone means.
[0015]
The SI component is added as an EG solution at 50 to 150 ° C., preferably 60 to 120 ° C. When the temperature is set to 50 ° C. or higher, the direct polymerization oligomer is not cooled excessively, the SI component and the direct polymerization oligomer easily become a uniform melt, the titanium oxide is well dispersed, and the titanium oxide aggregate is formed. Can be suppressed. Further, when the temperature is set to 150 ° C. or less, there is little by-product of DEG in the EG solution or in the reaction system, and insoluble foreign matters due to SI components are not formed in the EG solution, and a high-quality modified polyester is obtained. be able to.
[0016]
The concentration of the SI component EG solution is preferably 5 to 50%, more preferably 10 to 40%. When the concentration is 5% or more, there is little by-product of DEG in the reaction system, and a higher quality modified polyester can be obtained. In addition, when the concentration is 50% or less, the SI component and the direct heavy oligomer easily become a uniform melt, and the formation of titanium oxide aggregates can be further suppressed, the stability of the EG solution is good, and the SI component is precipitated. Easy to handle without settling.
[0017]
The EG solution of the SI component is added to the direct polymerization oligomer for 5 to 30 minutes, preferably 10 to 25 minutes continuously. When the addition time is 5 minutes or more, the SI component and the direct-weight oligomer easily become a uniform melt, and the formation of titanium oxide aggregates can be further suppressed. Further, when the addition time is 30 minutes or less, there is little by-product of DEG, and a higher quality modified polyester can be obtained. This continuous addition is preferably performed at a constant supply rate.
[0018]
Furthermore, when the EG solution of the SI component is added and held for 5 to 20 minutes, the SI component and the direct heavy oligomer become a uniform melt more easily, and the formation of titanium oxide aggregates can be further suppressed, and the by-product of the DEG This is preferable because a modified polyester of higher quality can be obtained. The temperature of the reaction system during the holding is preferably 210 to 260 ° C, and more preferably 220 to 250 ° C.
[0019]
Next, the titanium oxide used in the present invention is added in an amount of 0.01 to 5% by weight with respect to the polymer. When titanium oxide is added to the direct weight oligomer in advance or simultaneously with the SI component, a titanium oxide aggregate is formed. Even after the SI component is uniformly copolymerized, a part of the titanium oxide aggregate remains in the polymer. Therefore, it is important to add titanium oxide after the addition of the SI component. Preferably, holding for 5 to 20 minutes after the addition of the SI component, and addition after the SI component and the direct heavy oligomer form a more uniform melt, formation of titanium oxide aggregates can be further suppressed.
[0020]
As the polycondensation catalyst used in the present invention, metal compounds such as antimony and germanium generally used in the production of polyester can be used, and preferably antimony trioxide can be used.
[0021]
In the present invention, it is preferable to add an alkali metal compound because it is possible to further suppress the formation of DEG and to obtain a higher quality modified polyester. As the alkali metal compound used in the present invention, a hydroxide, an organic carboxylate and the like are preferable. Specific examples include sodium, potassium, and lithium hydroxides, carboxylates such as formate and acetate. The alkali metal compound may be added at any time from the end of the esterification reaction to the start of the polycondensation reaction, preferably from the time when the SI component is added to the time when the polycondensation catalyst is added.
[0022]
In the present invention, known additives such as a light resistance imparting agent such as a manganese compound and a stabilizer such as a phosphorus compound may be used.
[0023]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Each characteristic described in the present invention was measured by the following method.
[0024]
(1) Titanium oxide dispersible polymer (20 mg) was heated and dissolved on a slide glass, and the number of titanium oxide aggregates having a size of 5 μm or more was counted by microscopic observation. If it is 10 pieces / 20 mg or less, there is no practical problem, and further, 5 pieces / 20 mg or less is preferable.
[0025]
○○: 5 or less / 20 mg, ○: More than 5/10 or less / 20 mg, ×: More than 10/20 mg
(2) DEG
The polymer was thermally decomposed with monoethanolamine and then determined by gas chromatographic analysis, and judged in the following three stages. If it is 2.0% or less, there is no practical problem, and further 1.8% or less is preferable.
[0026]
○○: 1.8% or less, ○: more than 1.8% and less than 2.0%, ×: more than 2.0% (3) A 5 μm non-woven filter with an inner diameter of 25 mm was prepared by 2 kg of polymer melted at 280 ° C. The inside of the provided pack was allowed to pass through, and the pressure difference applied to the inside of the pack at the start of passage and at the end of passage was determined and determined in the following three stages. If it is 2 MPa or less, there is no practical problem, and 1.2 MPa or less is more preferable.
○○: 1.2 MPa or less, ○: more than 1.2 MPa and 2 MPa or less, ×: more than 2 MPa Example 1
A slurry of terephthalic acid and EG (EG / terephthalic acid molar ratio 1.2) was continuously fed for 3 hours to an esterification reactor in which bis (2-hydroxyethyl) terephthalate and its oligomer existed. During the supply of the slurry, a pressure of 0.1 MPa was applied to the esterification reactor and an esterification reaction was carried out at 250 ° C. to obtain a direct heavy oligomer having an esterification reaction rate of 97% in a reaction time of 4 hours.
[0027]
A 70% conversion SI component (SIHE: SIHA: SIDA = 5: 4: 1) produced by subjecting this straight oligomer to a transesterification reaction with dimethyl 5-sodium sulfoisophthalate and EG at a concentration of 30% The EG solution was heated to 90 ° C. and continuously added for 20 minutes so that the SI component was 8% by weight based on the modified polyester. Then, after maintaining at 240 ° C. for 10 minutes, 0.03% by weight of antimony trioxide, 0.2% by weight of lithium acetate, 0.03% by weight of phosphoric acid, and 0.3% by weight of titanium oxide were added. Then, pressure reduction was started and the polycondensation reaction was performed until the intrinsic viscosity ([η]) became 0.55. The properties of the resulting modified polyester are shown in Table 1.
[0028]
Example 2-5, Comparative Examples 1-4
A modified polyester was produced in the same manner as in Example 1 except that the temperature of the EG solution of the SI component, the continuous addition time of the EG solution of the SI component, and the reaction rate of the SI component were as shown in Table 1. The properties of the resulting modified polyester are shown in Table 1.
[0029]
[Table 1]

As can be seen from Table 1, in the examples according to the present invention, both the titanium oxide aggregates and DEG by-products are small and the filtration pressure rises slowly, whereas Comparative Examples 1 and 2 have the titanium oxide aggregates. A large number of filters were formed, and the filtration pressure increased rapidly. In Comparative Examples 3 and 4, there were many by-products of DEG, and further, insoluble foreign matters were formed due to the SI component, and the filtration pressure increased rapidly.
[0030]
【The invention's effect】
By carrying out the present invention, it is possible to produce a modified polyester obtained by copolymerizing an isophthalic acid component having a sulfonate group with a small amount of titanium oxide aggregates and a small amount of by-product of diethylene glycol by using a straight-weight oligomer.

Claims (2)

In the production of a modified polyester obtained by copolymerizing an isophthalic acid component having a sulfonate group using a direct heavy oligomer mainly composed of terephthalic acid and ethylene glycol, a dialkyl ester of the isophthalic acid component having a sulfonate group and ethylene An isophthalic acid component having a sulfonate group having a transesterification rate of 50 to 90% from glycol is added as an ethylene glycol solution at 50 to 150 ° C. to a direct polymerization oligomer, followed by addition of titanium oxide and polycondensation. The manufacturing method of the modified polyester characterized by the above-mentioned. A straight weight method in which an ethylene glycol solution of an isophthalic acid component having a sulfonate group having a transesterification rate of 50 to 90% from a dialkyl ester of an isophthalic acid component having a sulfonate group and ethylene glycol is continuously applied for 5 to 30 minutes. The method for producing a modified polyester according to claim 1, wherein the modified polyester is added to an oligomer.