JPH0466255B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for producing a copolymerized polyester, more specifically, a copolyester having a sufficient degree of polymerization, exhibiting a melt viscosity suitable for melt molding, especially melt spinning, and having excellent color tone.
Therefore, the present invention relates to a method for producing a cationic dye-dyable copolyester with significantly improved color development. <Prior Art> Polyester has many excellent properties and is therefore widely used as fibers and films, but it has low dyeability and is particularly difficult to dye with dyes other than disperse dyes. Various proposals have been made to improve this dyeability. One of the methods is to copolymerize polyester with an isophthalic acid component containing a sulfonic acid metal group, such as a 5-sodium sulfoisophthalic acid component, to make it dyeable with a cationic dye (Japanese Patent Publication No. -Refer to Publication No. 10497). However, in this method, when the isophthalic acid component containing the sulfonic acid metal base is copolymerized in an amount necessary to increase the dyeability to a satisfactory level, the thickening effect of the isophthalic acid component containing the sulfonic acid metal salt is caused. , the melt viscosity of the polymerization reaction product increases significantly,
It became difficult to sufficiently increase the degree of polymerization, and at the same time, spinning became difficult. Therefore, in order to keep the melt viscosity of a polyester copolymerized with an isophthalic acid component containing such an amount of sulfonic acid metal base to a range where polymerization is easy and spinning is possible, the degree of polymerization of the copolymerized polyester is kept low. There is a need. As a result, the strength of the resulting yarn decreases,
This significantly limits the uses of the resulting cationic dye-dyeable polyester fibers. On the other hand, a method using an isophthalic acid component having a quaternary phosphonium sulfonic acid base as a cationic dye dyeing agent is known (Japanese Patent Publication No. 47-22334
(see US Pat. No. 3,732,183). According to this method, the thickening effect during the polymerization reaction is small, so even if the degree of polymerization of the copolyester is increased,
The melt viscosity is kept within a range that allows normal spinning.
For this reason, high-strength cationic dye-dyeable polyester fibers can now be easily obtained, and in addition to the advantages of cationic dyes such as vivid color development and non-transferability, the high tenacity of yarn can be utilized to create products such as sportswear. There is a possibility of expanding the application to other fields. However, in this method, probably because the heat resistance of the isophthalic acid component containing a quaternary phosphonium sulfonic acid base used is poor, the decomposition is accelerated by itself under high heat conditions such as the polymerization reaction process of the copolymerized polyester or the melt molding process. This method has the serious drawback that the polyester produced and the spun yarn are colored yellow-brown, and furthermore, this coloration deteriorates the color tone when dyed. For this reason, this method has never been industrially adopted. <Problems to be Solved by the Invention> In view of the above-mentioned advantages of the copolymerized polyester obtained by copolymerizing an isophthalic acid component having a quaternary phosphonium sulfonic acid base, the inventors of the present invention sought to overcome the above-mentioned disadvantages by improving the stability of ordinary polyesters. Although various phosphorus compounds effective as agents were added, little effect was obtained in reducing the yellowish brown coloring described above.
As a result of further intensive study on this problem, the inventors of the present invention found that even if an isophthalic acid compound having a triphosphonium sulfonic acid base is used in a very small amount, the yellowish brown color caused by the isophthalic acid component having a quaternary phosphonium sulfonic acid base may occur. It has been discovered that this method has the effect of significantly suppressing coloring. The present invention was completed as a result of further studies based on this knowledge. <Structure of the Invention> That is, the present invention is directed to the production of polyester by reacting a difunctional carboxylic acid, mainly terphthalic acid, or an ester-forming derivative thereof with at least one alkylene glycol or an ester-forming derivative thereof. (a) from 0.5 to the difunctional carboxylic acid component at any stage until the production reaction is completed;
10.0 mol% of the following general formula () [In the formula, A ₁ is an aromatic group or an aliphatic group, X ₁ is an ester-forming functional group, X ₂ is an ester-forming functional group or a hydrogen atom that is the same as or different from X ₁ ,
R ₁ , R ₂ , R ₃ and R ₄ represent the same or different groups selected from alkyl groups and aryl groups. ] For the sulfonic acid quaternary phosphonium salt represented by and (b) the sulfonic acid quaternary phosphonium salt
The following general formula () in an amount of 0.5 to 10.0 mol% [In the formula, A ₂ is an aromatic group or an aliphatic group, X ₃ is an ester-forming functional group, X ₄ is an ester-forming functional group or a hydrogen atom that is the same as or different from X ₃ ,
R ₅ , R ₆ and R ₇ represent the same or different groups selected from alkyl groups and aryl groups. ] This is a method for producing a copolymerized polyester characterized by carrying out addition copolymerization of a tertiary sulfonic acid phosphonium salt represented by the following. The polyester used in the present invention is a polyester having terphthalic acid as the main acid component and at least one type of glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol as the main glycol component. The main target is It may also be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/or a part of the glycol component is replaced with the above-mentioned glycol or other diol component other than the main component. It may also be polyester. Examples of difunctional carboxylic acids other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid,
Aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as diphenoxyethane digabonic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. can be given. Furthermore, isophthalic acid having a sulfonic acid metal base such as 5-sodium sulfoisophthalic acid may be used as a copolymerization component within the range where the effects of the present invention can be substantially achieved. It is desirable to suppress the amount to less than 1.8 mol% based on the components. Examples of diol compounds other than the above-mentioned glycols include fatty acids such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S, alicyclic and aromatic diol compounds, and polyoxyalkylene glycols. can be given. Furthermore, polycarboxylic acids such as trimellitic acid and pyromellitic acid, polyols such as glycerin, trimethylolpropane, and pentaerythritol can be used as long as the polyester is substantially linear. Such polyesters can be synthesized by any method. For example, when talking about polyethylene terephthalate, it is usually a direct esterification reaction between terephthalic acid and ethylene glycol, or
A step in which a lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol are transesterified or terephthalic acid and ethylene oxide are reacted to produce a glycol ester of terephthalic acid and/or a low polymer thereof. It is produced by a one-stage reaction and a second-stage reaction in which the reactive materials of the first stage are heated under reduced pressure and polycondensed until a desired degree of polymerization is achieved. In the method of the present invention, the sulfonic acid quaternary phosphonium salt used as a copolymerization component has the following general formula () It is expressed as In the formula, A ₁ represents an aromatic group or an aliphatic group, and among them, an aromatic group is preferable. X ₁ represents an ester-forming functional group, and specific examples include

【formula】 【formula】

[Formula] (-CH ₂ )- _a OH, -O(-CH ₂ ) _b ---[-O(CH ₂ ) _b ]
― _d OH, (However, R' is a lower alkyl group or a phenyl group,
(a and d are integers of 1 or more, b is an integer of 2 or more), etc. X ₂ represents an ester-forming functional group or a hydrogen atom that is the same as or different from X ₁ , and is preferably an ester-forming functional group. R ₁ , R ₂ , R ₃ and R ₄ represent the same or different groups selected from alkyl groups and aryl groups. Such quaternary phosphonium sulfonic acid salts can generally be easily synthesized by reacting the corresponding sulfonic acid with phosphines or by reacting the corresponding metal sulfonic acid salt with quaternary phosphonium halides. Preferred specific examples of the quaternary phosphonium sulfonic acid salt include 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt, 3,5
-Dicarboxybenzenesulfonic acid ethyltributylphosphonium acid, 3,5-dicarboxybenzenesulfonic acid benzyltributylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid phenyltributylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid tetra Phenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid ethyltriphenylphosphonium salt, 3,
5-dicarboxybenzenesulfonic acid butyltriphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid benzyltriphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tetrabutylphosphonium acid, 3,5-
Dicarbomethoxybenzenesulfonic acid ethyltributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid benzyltributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid phenyltributylphosphonium salt,
3,5-dicarbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid ethyltriphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid butyltriphenylphosphonium salt, 3, 5-dicarbomethoxybenzenesulfonic acid benzyltriphenylphosphonium salt, 3-carboxybenzenesulfonic acid tetrabutylphosphonium salt, 3-carboxybenzenesulfonic acid tetraphenylphosphonium salt, 3-carbomethoxybenzenesulfonic acid tetrabutylphosphonium salt, 3 -Carbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetrabutylphosphonium salt, 3,5-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetraphenylphosphonium salt,
-hydroxyethoxycarbonyl)benzenesulfonic acid tetraphenylphosphonium salt, 3-(β
-Hydroxyethoxycarbonyl)benzenesulfonic acid tetrabutylphosphonium salt, 3-β-hydroxyethoxycarbonyl)benzenesulfonic acid tetraphenylphosphonium salt, 4-hydroxyethoxybenzenesulfonic acid tetrabutylphosphonium salt, 2,6-dicarboxynaphthalene-
4-sulfonic acid tetrabutylphosphonium salt, α
-Tetrabutylphosphonium sulfosuccinic acid and the like can be mentioned. The above quaternary phosphonium sulfonic acid salts may be used alone or in combination of two or more. In order to copolymerize the above quaternary phosphonium sulfonic acid salt into a polyester, it may be added at any stage before the synthesis of the polyester described above is completed, preferably at any stage before the first stage reaction is completed. good. The proportion of the quaternary phosphonium sulfonic acid salt copolymerized with the polyester is in the range of 0.5 to 10 mol% based on the bifunctional carboxylic acid component (excluding the sulfonate) constituting the polyester.
If the copolymerization ratio is less than 0.5 mol%, the resulting copolymerized polyester will have insufficient dyeability with cationic dyes, and if it exceeds 10 mol%, the cationic dyeability will no longer show any significant improvement, and the physical properties of the polyester will deteriorate. decreases, making it difficult to achieve the objective of the present invention. The sulfonic acid tertiary phosphonium salt used in combination with the above-mentioned sulfonic acid quaternary phosphonium salt is represented by the following general formula (). In the formula, A ₂ represents an aromatic group or an aliphatic group, and among them, an aromatic group is preferable. X ₃ represents an ester-forming functional group, as a specific example:

【formula】 【formula】

[Formula] (-CH ₂ )- _a OH, -O(-CH ₂ ) _b ---[-O(CH ₂ ) _b ]
― _d OH, (However, R' is a lower alkyl group or a phenyl group,
(a and d are integers of 1 or more, b is an integer of 2 or more), etc. X ₄ represents an ester-forming functional group or a hydrogen atom that is the same as or different from X ₃ , and is preferably an ester-forming functional group. R ₅ , R ₆ and R ₇ represent the same or different groups selected from alkyl groups and aryl groups. Such tertiary phosphonium sulfonic acid salts can be easily synthesized, for example, by reacting the corresponding metal sulfonic acid salts with tertiary phosphonium halides. Preferred specific examples of the tertiary phosphonium sulfonic acid salts include tributylphosphonium 3,5-dicarboxybenzenesulfonate, triethylphosphonium 3,5-dicarboxybenzenesulfonate, and tripropyl 3,5-dicarboxybenzenesulfonate. Phosphonium salt, 3,5-dicarboxybenzenesulfonic acid triphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid tribenzylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid trihexylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid triphenylphosphonium salt, Carboxybenzenesulfonic acid trioctylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid tricyclohexylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid butyldiphenylphosphonium salt,
3,5-dicarboxybenzenesulfonic acid phenyldibutylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tributylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid triethylphosphonium salt, 3,5-dicarboxybenzene Sulfonic acid tripropylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid triphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid tribenzylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid trioctylphosphonium salt ,3,
5-dicarbomethoxybenzenesulfonic acid tricyclohexylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid butyldiphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid phenyldibutylphosphonium salt,
m-carbomethoxybenzenesulfonic acid tributylphosphonium salt, m-carbomethoxybenzenesulfonic acid triphenylphosphonium salt, 3,5
-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid tributylphosphonium salt, 3,
5-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid triphenylphosphonium salt,
m-(β-hydroxyethoxycarbonyl)benzenesulfonic acid tributylphosphonium salt, m-
(β-hydroxyethoxycarbonyl)benzenesulfonic acid triphenylphosphonium salt, p-hydroxyethoxybenzenesulfonic acid tributylphosphonium salt, p-hydroxyethoxybenzenesulfonic acid triphenylphosphonium salt, 2,
Examples include tributylphosphonium 6-dicarboxynaphthalene-4-sulfonic acid salt and α-tributylphosphonium sulfosuccinic acid. To copolymerize the sulfonic acid tertiary phosphonium salt into a polyester, it may be added at any stage before the synthesis of the polyester described above is completed, preferably at any stage before the first stage reaction is completed. Bye. The relationship with the addition timing of the quaternary phosphonium sulfonic acid salt may be arbitrary, and both may be added separately or may be mixed in advance and added simultaneously. The amount of the sulfonic acid tertiary phosphonium salt used is 0.5 to 10.0 mol% based on the quaternary phosphonium wire.
The amount is particularly preferably in the range of 1.0 to 4.0 mol%. If the amount is less than 0.5 mol%, the effect of preventing the polyester produced or the spun yarn from being colored yellowish brown will be insufficient, and if the amount exceeds 10.0 mol%, the coloring prevention effect will no longer show any significant improvement, and the polyester will become more Formability and physical properties begin to deteriorate. In the step of producing the quaternary phosphonium sulfonic acid salt, a tertiary phosphonium sulfonic acid salt may be produced as a by-product, and a portion thereof may remain in the produced quaternary phosphonium sulfonic acid salt. In this case, if the purification conditions are controlled so that the amount of the remaining tertiary phosphonium sulfonic acid salt falls within the above range, there is no need to use it separately. <Effects of the Invention> According to the method of the present invention, thermal discoloration and thermal decomposition of the polymer during the synthesis reaction of polyester copolymerized with a quaternary phosphonium sulfonic acid salt, and further under high temperature conditions such as during melt molding, are significantly suppressed. As a result, it has become possible to industrially obtain cationic dye-dyable polyesters with high whiteness and high degree of polymerization, as well as molded products thereof. A high-strength cationic dyeable yarn with vivid colors can be obtained. In addition, an improvement in light resistance was observed, probably due to the suppression of polymer coloration and decomposition. The thus obtained quaternary phosphonium sulfonic acid salt copolymerized polyester has the following advantages over conventional sulfonic acid metal salt copolymerized polyester. (1) Compared to the metal ion of the sulfonic acid metal salt, the diffusion rate of the cationic dye is higher, probably because the sulfonic acid quaternary phosphonium salt is bulkier, so in the case of the sulfonic acid quaternary phosphonium salt, a smaller amount The same level of cationic dyeing property as sulfonic acid metal salts can be obtained. (2) Since the thickening effect inherent to sulfonic acid metal salts does not occur, melt spinning of highly polymerized polymers can be easily carried out using ordinary spinning methods, and high strength cationic dye-dyeable polyesters can be produced. Molded products can be easily obtained. (3) Furthermore, according to the present invention, since a quaternary phosphonium salt is used instead of a metal salt, the amount of foreign matter by-produced during the polycondensation reaction is small, and the back pressure increases during molding, especially during spinning, and the resulting The effect is that the decrease in yarn quality is small. (4) In relation to 2 and 3 above, the copolymerized polyester obtained by the present invention and method has extremely excellent spinnability, has a take-up speed of 3000 m/min or more,
In particular, spinning is possible even at ultra high speeds of 5000 m/min or higher. Also, 1 denier or less, and even
It is possible to spin ultrafine fibers of 0.5 denier or less. (5) Furthermore, the fibers obtained from the copolymerized polyester of the present invention do not cause problems of strength reduction or fusion even when subjected to false twisting processing at high temperatures, and can provide excellent processed yarns. . (6) Contrary to the fact that copolyesters copolymerized with sulfonic acid metal salts are extremely prone to generating static electricity, the copolyesters of the present invention exhibit excellent antistatic properties. (7) Furthermore, since the copolymerized polyester of the present invention contains a quaternary phosphonium salt, it has excellent flame retardancy and antibacterial properties. Note that the copolymerized polyester of the present invention may contain optional additives, such as catalysts, color inhibitors,
Heat resistant agents, flame retardants, antioxidants, matting agents, coloring agents,
Inorganic fine particles and the like may also be included. <Example> Examples will be given below for further explanation. Parts and % in Examples indicate parts by weight and % by weight, respectively.
The intrinsic viscosity [η] of the polymer was determined from the value measured in an orthochlorophenol solution at 35°C, and the softening point (SP) was measured by the penetration method. The hue of the polymer was indicated by the L value and b value determined by a Hunter color difference meter. The larger the L value, the better the whiteness, and the higher the b value on the + side, the stronger the yellowness. The number of terminal carboxyl groups in the polymer was determined by heating and dissolving a sample in benzyl alcohol and titrating with a sodium hydroxide solution. The larger the number of terminal carboxyl groups, the more thermal decomposition occurs. Examples 1 to 5 and Comparative Examples 1 and 2 100 parts of dimethyl terphthalate, 60 parts of ethylene glycol, 0.03 part of manganese acetate tetrahydrate (0.024 mol% relative to dimethyl terephthalate), and cobalt acetate tetrahydrate as a coloring agent. 0.009 part (0.007 mol% based on dimethyl terphthalate) was charged into a transesterification tank, and the mixture was heated for 3 hours under a nitrogen gas atmosphere.
The temperature was raised from 140°C to 220°C, and the resulting methanol was distilled out of the system while transesterification was carried out.
The product obtained was then treated with 3,5
- a mixture of dicarboxybenzenesulfonic acid tetrabutylphosphonium salt and 3,5-dicarboxybenzenesulfonic acid tributylphosphonium salt;
Add 20% heated ethylene glycol solution, 220
After stirring for 20 min at °C, orthophosphoric acid was added as a stabilizer.
0.03 part of a 56% aqueous solution (0.033 mol % based on dimethyl terephthalate) was added, and at the same time, expulsion of excess ethylene glycol by heating was started. After 10 minutes, 0.04 part of antimony trioxide (0.027 mol % based on dimethyl terephthalate) was added as a polycondensation catalyst. When the internal temperature reached 240°C, expulsion of ethylene glycol was completed and the reaction product was transferred to a polymerization vessel. Next, the reaction was carried out under normal pressure while increasing the temperature until the internal temperature reached 260℃, and then the temperature was increased to 760mm for 1 hour.
The pressure was reduced from Hg to 1 mmHg, and at the same time the internal temperature was raised to 280°C over 1 hour and 30 minutes. The polymerization reaction was terminated after further polymerization for 2 hours at a polymerization temperature of 280° C. under reduced pressure of 1 mmHg or less. The [η], SP, hue, and number of terminal carboxyl groups of the obtained polymer are
Shown in the table. These polymers are melt-spun and spun according to conventional methods.
The fibers obtained by stretching are dyed with cationic dye Cathilon CD−.
FRLH/Cathilon Blue CD-FBLH=1/1
(manufactured by Hodogaya Chemical Co., Ltd.) in a dye bath containing 2% owf (contains 3 g of mirabilite and 0.3 g of acetic acid as auxiliaries).
Stained for 60 min at °C. Table 1 shows the clarity of the dyed fabric. Example 6 and Comparative Example 3 In place of the 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt used as the cationic dye dyeable copolymerization component (sulfonic acid quaternary phosphonium salt) in Example 1 and Comparative Example 1 The same procedure as in Example 1 and Comparative Example 1 was conducted except that 3,5-dicarboxybenzenesulfonic acid tetraphenylphosphonium salt was used. The quality of the obtained polymer and the clarity of the dyed fabric were as shown in Table 1. Example 7 The same procedure was carried out except that 3,5-dicarboxybenzenesulfonic acid triphenylphosphonium salt was used in place of the 3,5-dicarboxybenzenesulfonic acid tributylphosphonium salt used as the sulfonic acid tertiary phosphonium salt in Example 1. Example 1
I did the same thing. The quality of the obtained polymer and the clarity of the dyed fabric are shown in Table 1. Example 8 and Comparative Example 4 3 and 5 used in Example 1 and Comparative Example 1
- The same procedure as in Example 1 and Comparative Example 1 was carried out except that the addition time of dicarboxybenzenesulfonic acid tetrabutylphosphonium salt and 3,5-dicarboxybenzenesulfonic acid tributylphosphonium salt was changed before the start of the transesterification reaction. . The result is the first
It was as shown in the table. Example 9 Same as Example 2 except that 0.014 part of sodium acetate trihydrate (0.020 mol % based on dimethyl terephthalate) was further used as an ether formation inhibitor and added before the start of the transesterification reaction. I went to The quality of the obtained polymer and the clarity of the dyed fabric were as shown in Table 1.

【table】

【table】

【table】

Claims (1)

[Scope of Claims] 1. In producing a polyester by reacting a difunctional carboxylic acid, mainly terephthalic acid, or an ester-forming derivative thereof with at least one alkylene glycol or an ester-forming derivative thereof, At any stage until the reaction is completed (a) from 0.5 to the difunctional carboxylic acid component;
10.0 mol% of the following general formula [In the formula, A ₁ is an aromatic group or an aliphatic group, X ₁ is an ester-forming functional group, _{X 2} is the same or different ester-forming functional group or hydrogen atom, R ₁ , R ₂ ,
R ₃ and R ₄ represent the same or different groups selected from alkyl groups and aryl groups. ] Sulfonic acid quaternary phosphonium salt represented by
(b) For the sulfonic acid quaternary phosphonium salt
The following general formula () in an amount of 0.5 to 10.0 mol% [In the formula, A ₂ is an aromatic group or an aliphatic group, X ₃ is an ester-forming functional group, _{X 4} is the same or different ester-forming functional group or hydrogen atom, R ₅ , R ₆
and R ₇ represent the same or different groups selected from alkyl groups and aryl groups. ] A method for producing a copolymerized polyester, which comprises adding and copolymerizing a sulfonic acid tertiary phosphonium salt represented by the following.