JP2001172485A - Modified polyester composition and fiber comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a modified polyester composition dyeable with a cationic dye, exhibiting a good spinnability suitable for manufacturing ultra fine fibers. SOLUTION: The polyester composition comprises a modified polyester obtained by copolymerizing 5-sodium sulfo isophthalic acid component and/or an isophthalic acid component having a phosphonium slat of sulfonic acid group, and at least one compound selected from the group consisting of a hindered phenolic compound, an alkylsulfonic acid or its metal salt, an alklylarylsulfonic acid or its metal salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified polyester and a modified polyester fiber which can be dyed with a cationic dye. More specifically, the present invention relates to a modified polyester which has a remarkably suppressed thickening effect and is improved in producing ultrafine fibers. The present invention relates to a modified polyester exhibiting a yarn property and a modified polyester fiber having significantly improved physical properties such as strength and abrasion resistance.

[0002]

2. Description of the Prior Art Polyesters are widely used as fibers and films because of their many excellent properties.
Among them, polytrimethylene terephthalate obtained by polycondensing terephthalic acid or a lower alcohol ester of terephthalic acid represented by dimethyl terephthalate with trimethylene glycol (1,3-propanediol) has a low elastic modulus. It is an epoch-making polymer that has characteristics such as soft texture and excellent elastic recovery, and has performance similar to polyamide and polyester. It is attracting attention not only in the field of materials but also in the field of clothing. However, it is difficult to dye polytrimethylene terephthalate with dyes other than disperse dyes, and improvements have been demanded.

[0003] As a method of improving the dyeability, for example, it is possible to dye with a cationic dye by copolymerizing an isophthalic acid component having a sulfonic acid metal base such as 5-sodium sulfoisophthalic acid in the polyester main chain. It has been known for a long time (Japanese Patent Publication No. 34-10
497). However, in this method, the melt viscosity of the polymer is remarkably increased by copolymerization of the components, and the degree of polymerization is sufficiently increased and, of course, molding such as spinning becomes difficult. As a result, only a low-strength molded product was obtained, and it was extremely difficult to spin ultrafine fibers having a dtex of 1.1 dtex or less, especially when molding into fibers.

Further, a method for producing a modified polyester obtained by copolymerizing an isophthalic acid component having a phosphonium sulfonate group and a modified polyester fiber have been proposed (see Japanese Patent Publication No. 3-61766), but in particular, polymethylene terephthalate. Because of its physical properties, which are inferior to polyethylene terephthalate in heat resistance, it has been desired to develop a copolymerizable cationic dye dyeing assistant which further reduces the thickening effect in order to maintain strength.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to improve the dyeability of a cationic dye exhibiting good spinnability when producing ultrafine fibers. It is to provide a polyester composition.

[0006]

Means for Solving the Problems In view of the above-mentioned prior art, the present inventors have made intensive studies especially on a cationic dye dyeing auxiliary agent, and have completed the present invention.

That is, an object of the present invention is to provide a polyester in which trimethylene terephthalate units account for at least 80 mol% based on all repeating units, a 5-sodium sulfoisophthalic acid component and / or an isophthalic acid component having a phosphonium sulfonate base. Is 0.1 to 10 mol% based on the acid component (excluding the 5-sodium sulfoisophthalic acid component or the isophthalic acid component having a phosphonium sulfonate group) constituting the polyester.
A copolymerized modified polyester having an intrinsic viscosity of 0.7 to 1.5, wherein the modified polyester comprises a hindered phenol compound (A), an alkylsulfonic acid, or a metal salt thereof, or an alkylarylsulfonic acid. Or at least one compound (B) selected from the group consisting of metal salts thereof, which is derived from the burning off of the compound (B) when held in an air atmosphere by a differential thermal analyzer, This is achieved by the modified polyester composition, characterized in that the time T in which the exothermic peak is observed (exothermic induction time) T is 10 or more.

[0008]

## EQU2 ## T = t ₂ / t ₁ (where, t ₁ is a heat generation induction time when the temperature is maintained at 320 ° C.,
t ₂ indicates the heat generation induction time when the temperature is maintained at 250 ° C., respectively. )

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polytrimethylene terephthalate used in the present invention means that the acid component is terephthalate and the glycol component is trimethylene glycol (1,
3-propanediol). In the modified polyester of the present invention, it is necessary that trimethylene terephthalate units account for at least 80 mol% of all the repeating units. If it is less than this, the characteristics of polytrimethylene terephthalate such as soft texture and elastic recovery will be impaired.

The 5-sodium sulfoisophthalic acid component used as a copolymer component in the present invention is 5-sodium sulfoisophthalic acid component.
Sodium sulfoisophthalic acid, dimethyl 5-sodium sulfoisophthalate, diethyl 5-sodium sulfoisophthalate, and the like can be suitably used. Examples of the isophthalic acid component having a sulfonate phosphonium base include isophthalic acid having a tetrabutyl phosphonium salt and a dibutytyl diethyl phosphonium salt as the base. These may be used alone or in combination of two or more, and the copolymerization amount thereof is determined by the acid component (5-) constituting the modified polyester of the present invention.
Excludes sodium sulfoisophthalic acid component or isophthalic acid component with phosphonium sulfonate base. ) Based on 0.1 to 10 mol%. If the copolymerization amount is less than 0.1 mol%, good cationic dyeability cannot be obtained, while if it exceeds 10 mol%, the melt viscosity becomes high, resulting in poor spinnability or heat stability. It becomes inferior in nature.

Other components may be copolymerized as long as they are within the above-mentioned copolymerization range. Examples of the components which may be copolymerized include isophthalic acid as an acid component other than terephthalic acid. Aromatic, aliphatic or naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid Alicyclic carboxylic acids can be mentioned, while the glycol components other than trimethylene glycol include cyclohexane-
Alicyclic, aliphatic or aromatic diol compounds such as 1,4-dimethanol, neopentyl glycol, bisphenol A and bisphenol S can be mentioned.

Further, within a range not to impair the object of the present invention, polycarboxylic acids such as trimellitic acid and pyromellitic acid, and polyols such as glycerin, trimethylolpropane and pentaerythritol can also be used.

The modified polyester of the present invention needs to have an intrinsic viscosity in the range of 0.7 to 1.5. When the intrinsic viscosity is less than 0.7, the spinnability is poor, and poor physical properties such as strength and abrasion resistance when formed into ultrafine fibers occur. On the other hand, if it exceeds 1.5, the viscosity is too high and the spinnability is rather poor, resulting in disadvantages such as an increase in the thread breakage rate.

[0014] The modified polyester as described above can be produced by any method, usually by directly esterifying terephthalic acid with trimethylene glycol, or with a lower alkyl ester of terephthalic acid such as dimethyl terephthalate. A first-stage reaction in which a transesterification reaction of trimethylene glycol or a reaction of terephthalic acid with trimethylene oxide to form a glycol ester of terephthalic acid and / or a low polymer thereof is performed; The reaction product is produced by a second-stage reaction in which a polycondensation reaction is carried out by heating under reduced pressure to a desired degree of polymerization. Further, the degree of polymerization can be further increased by a solid phase polymerization method.

In the present invention, it is necessary to contain the above-mentioned hindered phenol compound. A hindered phenol compound is a phenolic compound having a sterically hindered substituent on one or both of the two carbon atoms adjacent to the carbon atom having a phenolic hydroxyl group.

Preferred specific examples of the hindered phenol compound include 3,9-bis [2- [3- (3-te
rt-butyl-4-hydroxy-5-methylphenyl)
Propoxy] -1,1-dimethylethyl] -2,4,
8,10-tetraoxaspiro [5,5] undecane,
Triethylene glycol bis- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,1-bis (2-methyl-4-hydroxy-5-
tert-butylphenyl) butane, tris (4-alkyl-3-hydroxy-2,6-dimethylbenzyl)-
s-Triazine-2,4,6- (1H, 3H, 5H)-
Trione and tris (2,4-dialkyl-3-hydroxy-6-methylbenzyl) -s-triazine-2,4
6- (1H, 3H, 5H) -trione and the like, and as the alkyl group, secondary and tertiary alkyl groups having 3 to 12 carbon atoms are preferable.

The above hindered phenol compound is
Even if only one kind is used or two or more kinds are used in combination, it does not matter at all. Further, the content of the hindered compound is set to 0.1 based on the total weight of the modified polyester.
It is preferably in the range of 0.01 to 5%, and 0.01 to 1%.
% Is particularly preferred. When it is within the above range, the spinnability improving effect is particularly improved.

Further, the modified polyester of the present invention includes:
It is necessary to contain at least one compound selected from the group consisting of alkylsulfonic acids or metal salts thereof or alkylarylsulfonic acids and / or metal salts thereof.

Alkyl sulfonic acid includes 6 carbon atoms.
Alkylsulfonic acids in the range of from to 30 are preferred,
Examples include hexylsulfonic acid (having 6 constituent carbon atoms), decylsulfonic acid (having 10 constituent carbon atoms), and tetradecylsulfonic acid (having 14 constituent carbon atoms). Examples of the metal salts include potassium, sodium, lithium and calcium salts of alkylsulfonic acids. Among them, sodium tetradecylsulfonate (having 14 carbon atoms) is preferable because it has an excellent effect of suppressing thickening and is relatively stable to heat.

Examples of the alkylarylsulfonic acid include methylbenzenesulfonic acid, hexylbenzenesulfonic acid, dodecylbenzenesulfonic acid and the like.
Examples of the metal salt include a potassium salt, a sodium salt, and a calcium salt of an alkylbenzenesulfonic acid. Particularly preferred is sodium hexylbenzenesulfonate having excellent thermal stability.

In the present invention, the content selected from the group consisting of alkylsulfonic acids or metal salts thereof or alkylarylsulfonic acids or metal salts thereof may be one kind or a mixture of two or more kinds.

In the present invention, the content of the alkylsulfonic acid or the metal salt thereof or the alkylarylsulfonic acid is preferably from 0.01 to 10% based on the total weight of the modified polyester. Is within this range, the thickening suppressing effect and the thermal stability can be combined at a high level. Particularly preferably, it is 0.1 to 1%.

The composition of the present invention may further contain, if necessary, other antioxidants, ultraviolet absorbers, flame retardants, fluorescent brighteners, matting agents, coloring agents, and other additives. You may.

The modified polyester composition of the present invention has a time (heat generation) at which an exothermic peak represented by the following formula, which is derived from burning out of the compound (B) when held in an air atmosphere by a differential thermal analyzer, is observed. (Induction time) ratio T must be 10 or more.

[0025]

T = t ₂ / t ₁ (where, t ₁ is a heat generation induction time when the temperature is kept at 320 ° C.,
t ₂ indicates the heat generation induction time when the temperature is maintained at 250 ° C., respectively. )

If the T value is less than 10, sufficient strength and abrasion resistance cannot be obtained, resulting in frequent spun yarn breakage and poor abrasion resistance. The preferred T value is 20 or more, and a cationic dyeable polyester fiber having excellent heat resistance and strength can be obtained extremely stably.

In the case of producing fibers from the modified polyester composition of the present invention, any yarn-making conditions can be employed without any trouble. For example, a method of melt-spinning at a speed of 500 to 2500 m / min, stretching and heat treatment, 1500
A method of performing melt spinning at a speed of up to 5000 m / min and simultaneously or successively performing drawing and false twisting; a method of performing melt spinning at a high speed of 5000 m / min or more, and omitting the stretching depending on the application; Conditions can be adopted. At this time, the cross-sectional shape and fineness of the obtained fiber may be arbitrarily determined, but the effect of the present invention is particularly effective when the cross-sectional shape is an irregular cross-section other than circular or when the single-fiber fineness is 1 denier or less. Is particularly remarkably exhibited.

Further, the composition of the present invention can be used for the production of films and sheets, and in this case, any molding conditions can be adopted without any trouble. For example, a method of producing an anisotropic film by applying a tension in only one direction after film formation, a method of stretching a film in two directions simultaneously or in any order, and a method of stretching a film in two or more stages in multiple stages, etc. It can be adopted under any conditions.

[0029]

EXAMPLES The present invention will be described in more detail with reference to specific examples, but the present invention is not limited to these examples. Parts and% in Examples are parts by weight and% by weight, respectively. The intrinsic viscosity [η] of the polymer is 35
It was determined from the value measured with an orthochlorophenol solution at ° C.

The T value indicating the heat stability was measured as follows. A drawn yarn sample (10 mg) was weighed and measured by a differential thermal analyzer (Du).
Thermal A manufactured by Pont Instruments
nalyst 2100) in an air atmosphere at 10 ° C.
The temperature was raised to a predetermined temperature at a rate of / minute, and then maintained at the same temperature, and the time until the decomposition exothermic peak was observed (exothermic induction time) was measured. The heat induction time is 250 ° C and 320 ° C.
The T value was evaluated by the following formula.

[0031]

T = t ₂ / t ₁ (where, t ₁ is a heat generation induction time when the temperature is kept at 320 ° C.,
t ₂ indicates the heat generation induction time when the temperature is maintained at 250 ° C., respectively. )

Example 1 Dimethyl terephthalate 100
Parts, 60 parts of trimethylene glycol, 0.079 part of tetrabutoxytitanium as a catalyst, and a transesterification reaction of 5-sodium sulfoisophthalic acid as a cationic dye dyeing agent in an amount of 1.5 mol% based on dimethyl terephthalate. Charged in a can and put 140
The temperature was raised from 210 ° C. to 210 ° C., and transesterification was performed while distilling off the generated methanol out of the system.

Subsequently, 2 parts of sodium octylbenzenesulfonate and 3,9-bis [2-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) as a hindered phenol compound were added to the obtained product. ) Propoxy] -1,1-dimethylethyl] -2,4,8,10
0.5 parts of tetraoxaspiro [5,5] undecane was added, and a 56% aqueous solution of orthophosphoric acid 0.0 as a stabilizer was added.
Three parts (0.033 mol% based on dimethyl terephthalate) were added, and at the same time, excess trimethylene glycol was expelled. The reaction product was transferred to a polymerization vessel and reacted at normal pressure while raising the temperature until the internal temperature reached 215 ° C.
The pressure was reduced from normal pressure to 133 Pa over time, and at the same time, the internal temperature was raised to 265 ° C. over 1 hour and 30 minutes. 133P
a, the polymerization is further continued under a reduced pressure of
When the motor power value of the stirring blade rotating at a constant speed of m reached a predetermined value, the polymerization reaction was terminated, and the polymer was discharged under nitrogen gas pressurization, cooled, and formed into chips. The intrinsic viscosity [η] of the obtained polymer was 0.706.

After the obtained polymer chip was dried by a conventional method, it was melted at 265 ° C. using a spinneret having 72 circular ejection holes having a diameter of 0.15 mm, and was spun at a take-up speed of 3300 m / min. Thus, an ultrafine fiber yarn of 40 dtex / 72 filament (single fiber 0.555 dtex) was obtained. At this time, the running distance of the yarn from the spinneret to the first take-up roller (godet roller) was 3 m. The spinning condition at this time was good, and the intrinsic viscosity [η] of the yarn was 0.68.
0, the breaking strength of the yarn was 3.15 g / dtex, and the breaking elongation of the yarn was 40%. The T value was 23. This yarn is a cationic dye (Cathilon Blue CD-F)
RLH / Cathilon BlueCD-FBLH =
1/1 (manufactured by Hodogaya Chemical Co., Ltd.)) was able to dye a bright blue color. The results are shown in Table 1.

Example 2 The same operation as in Example 1 was carried out except that the 5-sodium sulfoisophthalic acid component was changed to 3,5-dicarbomethoxybenzenesulfonic acid tetra-n-butylphosphonium salt. . Table 1 shows the results.

Example 3 The same operation was performed as in Example 1, except that sodium tetradecylsulfonate was used instead of octylbenzenesulfonic acid. Table 1 shows the results.

Comparative Example 1 A transesterification reaction, a polycondensation reaction and a high-speed spinning were carried out in the same manner as in Example 1 except that neither the alkylbenzene sulfonic acid nor the hindered phenol compound was added. . The intrinsic viscosity [η] of the polymer obtained by terminating the polymerization reaction when the motor power value of the polymerization stirring blade reached the same value as in Example 1 was 0.699. The spinning condition during high-speed spinning was almost good, but single yarn breakage sometimes occurred. The T value was 5. The intrinsic viscosity [η] of the yarn is 0.66
0, the breaking strength of the yarn was 2.25 g / dtex, and the breaking elongation of the yarn was 43%. The results are shown in Table 1.

Comparative Example 2 The same operation as in Example 1 was carried out except that the hindered phenol compound was not added. Table 1 shows the results.

[0039]

[Table 1]

[0040]

As described above, the modified polyester composition of the present invention has a markedly reduced viscosity at the time of melting, so that it is possible to provide a modified polyester having excellent spinnability of ultrafine fibers. In addition, since it is possible to increase the degree of polymerization and lower the melt viscosity, polyester with high strength and high abrasion resistance, while maintaining the high texture and elastic recovery characteristic of polymethylene terephthalate. A molded article such as a fiber can be provided.

Since the modified polyester fiber of the present invention has a color developing property, strength and softness exceeding that of nylon, it can be usefully used for clothing.

The fiber obtained by melt-spinning the modified polyester of the present invention to a higher degree of polymerization by the solid-state polymerization method has high strength, excellent abrasion resistance, and can be dyed with a cationic dye. It is extremely useful as a fashionable material for material use.

The films and sheets obtained from the modified polyester of the present invention are very useful because they have excellent strength and abrasion resistance, and also have excellent antistatic properties, water absorption, printing properties, adhesive properties and the like. is there.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) D01F 6/92 301 D01F 6/92 301D 301J

Claims (3)

[Claims] 1. A polyester in which trimethylene terephthalate units occupy 80 mol% or more based on all repeating units, and a 5-sodium sulfoisophthalic acid component and / or an isophthalic acid component having a phosphonium sulfonate group constitute the polyester. 0.1 to 10 mol% based on the acid component (excluding the 5-sodium sulfoisophthalic acid component or the isophthalic acid component having a phosphonium sulfonate group).
A modified polyester of 7 to 1.5, wherein the modified polyester is a group consisting of a hindered phenol compound (A) and an alkylsulfonic acid or a metal salt thereof, an alkylarylsulfonic acid or a metal salt thereof. And an exothermic peak represented by the following formula, which is caused by burning of the compound (B) when the compound (B) is held in an air atmosphere by a differential thermal analyzer, is observed. The modified polyester composition, wherein the ratio T (heat generation time) is 10 or more. T = t ₂ / t ₁ (where, t ₁ is a heat generation induction time when the temperature is maintained at 320 ° C.,
t ₂ indicates the heat generation induction time when the temperature is maintained at 250 ° C., respectively. ) 2. A fiber comprising the modified polyester composition according to claim 1. 3. The fiber according to claim 2, wherein the single fiber fineness is 0.5 to 1.1 dtex.