JP2002317381A - Method for producing hydrophilic polyester-based fiber excellent in durability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a hydrophilic polyester-based fiber excellent in durability, capable of obtaining a product exhibiting good hydrophilic property even after carrying out wet forming such as washing, papermaking or water needling. SOLUTION: This method for producing the hydrophilic polyester-based fiber comprises attaching a treating agent, comprising (A) an aliphatic polyepoxy compound having two or more epoxy groups in the molecule and (B) a polyether polyester copolymer in which 40-95 wt.% of components is occupied by a polyalkylene glycol component, in an amount of 0.1-5.0 wt.% based on fiber weight to the surface of a polyester-based fiber and then bonding the treating agent to the fiber by heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber having excellent hydrophilicity. More specifically, a hydrophilic polyester fiber having excellent hydrophilic durability, and in particular, excellent durability is maintained even after washing and in applications where wet processing such as papermaking or water needle processing is performed. And a method for producing the same.

[0002]

2. Description of the Related Art Synthetic fibers represented by polyester are:
Because of its excellent mechanical strength, chemical resistance, heat resistance, etc., it is used in a wide range of fields such as clothing and cotton, industrial materials, household goods, sanitary materials, artificial leather, and the like. However, since synthetic fibers are more hydrophobic than natural fibers such as cotton, hemp, wool and the like, and semi-synthetic fibers such as rayon, various methods have been proposed to impart hydrophilicity comparable to that of natural fibers. I have.

For example, a method of treating a polyester fiber with an aqueous dispersion of a polyether polyester block copolymer comprising an aromatic polyester segment and a hydrophilic polyoxyalkylene segment (JP-B-45-13)
No. 17, JP-B-47-2512). A method of treating the aromatic polyester segment with a polyether polyester block copolymer obtained by copolymerizing a sulfoisophthalic acid alkali metal salt component (JP-A-59-183786, JP-B-63-46).
191) has also been proposed.

However, the polyester fibers obtained by these methods, when subjected to wet processing in which a high-pressure water flow acts such as washing, papermaking or water needling, the hydrophilicity of the fibers is compared with that before washing and before wet processing. Therefore, there is a problem that the resulting product is likely to have insufficient hydrophilicity. In order to cover the problem of the decrease in hydrophilicity, a method of additionally attaching a hydrophilic substance such as an aqueous dispersion of a polyester polyether copolymer to the product after molding is considered, but the feeling of the obtained product becomes hard. This tends to impair the soft feel of products obtained by wet molding or water needle processing.

As another method, a polymerizable monomer having a hydrophilic group is polymerized on the fiber surface to form a hydrophilic coating on the fiber surface (Japanese Patent Application Laid-Open No. 53-130396). A method in which a vinyl monomer having an acidic group is graft-polymerized on the fiber surface and then treated with a hydrophilic processing agent (Japanese Patent Application Laid-Open No. 7-90774), a method of dissolving water in an aqueous dispersion of a polyether polyester block copolymer. A method of treating with a treatment liquid to which a heat-reactive urethane and an acidic amino acid or a derivative thereof are added (JP-A-6-41872)
JP-B-36-6645, JP-B-38-17898, and JP-A-55-90680.
Publication) and the like.

However, in these methods, although the durability of hydrophilicity is improved as compared with the above-mentioned methods, the level is still insufficient and further improvement is desired. .

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object to provide good hydrophilicity even after washing, wet forming such as paper making or water needling. It is an object of the present invention to provide a method for producing a hydrophilic polyester fiber having excellent durability, which can provide a product exhibiting the following.

[0008]

According to the study of the present inventors, the above-mentioned object has been achieved by using an aliphatic polyepoxy compound (A) having two or more epoxy groups in the molecule, 40 to 95% by weight. A polyether polyester copolymer (B) occupied by a polyalkylene glycol component and a treating agent containing 0.1 to 5.0% by weight based on the weight of the fiber, A method for producing a hydrophilic polyester fiber having excellent durability characterized by being fixed by heat treatment. "

[0009]

Embodiments of the present invention will be described below in detail. First, the polyester fiber of the present invention refers to a fiber in which at least the fiber surface is composed of a polyester. As such a polyester, a polyester comprising an aromatic dicarboxylic acid having excellent thermal and mechanical properties and a glycol component Is the main target.
As the aromatic dicarboxylic acid component preferably used,
For example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyletherdicarboxylic acid, methyl terephthalic acid, methyl isophthalic acid, metal salts of 5-sulfoisophthalic acid, and the like, Particularly, terephthalic acid is preferred. On the other hand, preferred glycol components include, for example, ethylene glycol, trimethylene glycol, tetramethylene glycol, neopentylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, etc., and particularly, ethylene glycol, trimethylene glycol. And tetramethylene glycol are preferred. In addition, aliphatic dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, and ε-oxycaproic acid at a ratio of 30 mol% or less, particularly preferably 20 mol% or less, Components such as oxycarboxylic acids such as oxybenzoic acid and hydroxyethoxybenzoic acid, bisphenol A, and hydroquinone may be copolymerized.

[0010] Such polyesters contain various additives and functionalizing agents such as ultraviolet absorbers, antioxidants, pigments, optical brighteners, matting agents, flame retardants, plasticizers and the like. Is also good.

In the present invention, the aliphatic polyepoxy compound (A) having two or more epoxy groups in the molecule on the surface of the polyester fiber and 40 to 95% by weight of the polyalkylene glycol component are occupied. It is important to attach a treating agent containing the polyether polyester copolymer (B).

Here, the aliphatic polyepoxy compound (A) having two or more epoxy groups in a molecule is defined as an aliphatic polyepoxy compound having at least two epoxy groups in a molecule and being an aliphatic compound. Although it is optional, it is particularly possible to use two epoxies such as polyglycidyl ether of a water-soluble or water-dispersible aliphatic polyhydric hydroxy compound, specifically, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether. Preferred examples include those having three or more epoxy groups such as those having a group, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, and polyglycerol polyglycidyl ether. In particular, those having two epoxy groups are preferable because they can form a linear chain by a curing reaction such as heat treatment. Particularly, dioxyethylene glycol having a degree of polymerization of 1 to 30 oxyethylene units is preferred. Glycidyl ether is preferred in that higher hydrophilic durability can be imparted.

Here, when the number of epoxy groups in the epoxy compound is one, the hydrophilic durability of the obtained fiber is insufficient even after the heat treatment described later, and the fiber is not washed, paper-made or water-needled. When such wet processing as described above is performed, the treatment agent tends to fall off, which is not preferable.

On the other hand, the component used in combination with the aliphatic polyepoxy compound having two or more epoxy groups in the molecule used in the present invention is a polyalkylene glycol component which accounts for 40 to 95% by weight of the polyalkylene glycol component. It is an ether polyester copolymer (B). Here, when the proportion of the polyalkylene glycol component is less than 40% by weight, it is difficult to achieve the excellent hydrophilicity aimed at by the present invention. The affinity of the treated film with the fibers is reduced even if heat treatment is performed, and it is difficult to achieve the excellent hydrophilicity after washing or wet molding as the object of the invention. Is not preferred.

Examples of preferably used polyalkylene glycol components include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and random or block copolymers of ethylene oxide and propylene oxide.
Among them, polyethylene glycol is preferred from the viewpoint of hydrophilic performance. If the average molecular weight is too small, the hydrophilicity tends to decrease. On the other hand, if the average molecular weight is too large, the durability of the hydrophilicity tends to decrease.
A range of 0000 is appropriate.

As the dicarboxylic acid component constituting the polyether polyester copolymer (B), for example, terephthalic acid, isophthalic acid and alkali metal salt sulfoisophthalic acid are preferably used, and adipic acid, sebacic acid and azelaic acid are used. , Dodecanoic acid, 1,4-cyclohexanedicarboxylic acid and the like may be copolymerized in a small amount. Particularly, terephthalic acid and isophthalic acid and / or an alkali metal salt sulfoisophthalic acid are used at a ratio of 40:60 to 100: 0.
It is preferable to use together a molar ratio (terephthalic acid: isophthalic acid and / or alkali metal salt sulfoisophthalic acid). In this case, if the ratio of the alkali metal salt sulfoisophthalic acid is too large, the coating film of the treating agent tends to be hard and brittle. In addition, since the water solubility is too high and the hydrophilic durability tends to decrease, the content ratio of the component in the dicarboxylic acid component is desirably 40 mol% or less.

On the other hand, the diol component constituting the polyether polyester copolymer (B) may be the above-mentioned polyalkylene glycol alone, but from the viewpoint of improving the affinity with the polyester fiber, a diol component having a low molecular weight is used in combination. Is preferred. Preferably used diol components include ethylene glycol, trimethylene glycol,
In addition to alkylene glycols having 2 to 6 carbon atoms such as tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and bisphenol A can be exemplified. Among them, the same as the glycol component of the polyester fiber is particularly preferable.

The above-mentioned polyether polyester copolymer (B) is coated with a treatment agent coating by the reaction between the terminal functional group of the copolymer and the aliphatic polyepoxy compound (A). As long as the durability improvement effect is not impaired, one hydroxyl group of the polyalkylene glycol is, for example, a methyl group, in order to adjust the molecular weight of the copolymer.
One-terminal-blocked polyalkylene glycol type etherified with an ethyl group, a phenyl group or the like may be used.
However, in order to obtain higher hydrophilic durability, it is preferable that the terminal group is not blocked.

The mixing ratio of the aliphatic polyepoxy compound (A) and the polyether polyester copolymer (B) described above tends to decrease the hydrophilicity obtained when the former ratio is too large. On the other hand, if the amount is too small, the desired improvement in the hydrophilic durability tends to be small, so that the mixture weight ratio is (A) :( B) in the range of 10:90 to 8: 8.
A range of 0:20, particularly a range of 30:70 to 70:30 is preferred.

The treating agent used in the present invention contains a polyoxyalkylene alkyl tertiary amine (C) in addition to the aliphatic polyepoxy compound (A) and the polyether polyester copolymer (B). Is preferred. Since the tertiary amine (C) has a catalytic action of forming a cured film by a reaction between an epoxy group and a terminal hydroxyl group of, for example, a polyether polyester copolymer, a treatment agent film is more effectively formed, Furthermore, hydrophilicity with excellent durability can be obtained. Further, since the tertiary amine also has an effect of improving the wettability of the treating agent to the polyester-based fiber, the treating agent can quickly and uniformly permeate the polyester-based fiber between the fibers, More uniform hydrophilicity can be imparted.

It is essential that the polyoxyalkylenealkylamine is a tertiary amine, and the primary amine or the secondary amine has too large a catalytic action, and the tertiary amine cross-linking reaction proceeds rapidly. Therefore, the treatment agent film formed on the fiber surface cannot be made uniform, and conversely, the hydrophilic durability tends to decrease.

As the polyoxyalkylene alkyl tertiary amine (C) preferably used, the polyoxyalkylene group is a polyoxyethylene unit, and the total oxyethylene unit is in the range of 3 to 12, especially 6 to 10 A range is preferred. When the total number of oxyethylene units is 2 or less, the stability when the treating agent is used as an aqueous emulsion tends to decrease, while when it exceeds 13, the curing reaction catalysis of the treating agent film is insufficient. And the effect of improving the hydrophilic durability by the combined use of the tertiary amine is not recognized.

Also, polyoxyalkylene alkyl tertiary
If the number of carbon atoms of the alkyl group of the secondary amine is too small, the stability of the treating agent aqueous emulsion improves, but it tends to be colored and yellowish at the time of heat treatment, and if too large, the stability of the treating agent aqueous emulsion decreases. Thus, a range of 10 to 22, particularly a range of 12 to 18 is appropriate.

Such polyoxyalkylene alkyl tertiary
The amount of the tertiary amine (C) is 0.1 to 30% by weight, especially 0.1% by weight, based on the weight of the aliphatic polyepoxy compound (A).
A range of 1 to 20% by weight is suitable.

The polyoxyalkylene alkyl tertiary amine (C) is an aliphatic polyepoxy compound (A)
Catalyzing the curing of the tertiary amine treatment agent coating, even before or after the treatment agent is applied to the fiber surface, separately from the treatment agent containing the tertiary amine and the polyether polyester copolymer (B). The presence of the tertiary amine in the treating agent is preferred because the uniformity of the treating agent film is further improved and the hydrophilic durability is further improved.

In the present invention, the treatment agent described above must be applied in an amount of 0.1 to 5.0% by weight (as an active ingredient), particularly 0.3 to 2.0% by weight, based on the weight of the fiber. There is. When the amount is less than 0.1% by weight, the hydrophilic durability cannot be improved after washing or wet forming such as paper making and water needling, which is the object of the present invention. On the other hand, when the content exceeds 5.0% by weight, the card passing property such as winding onto the roller card clothing and scum generation is deteriorated, and water used in paper making and water needling is easily contaminated by falling off substances. It is not preferable.

The main method of attaching the treating agent to the fiber surface is as follows.
As the aqueous emulsion, besides a method of removing water by drying after dipping the fibers, a method of attaching the fibers by a roller or a guide provided with a spray or emulsion can be adopted. In addition, using an aqueous emulsion is
Since no harmful organic solvent is generated in the process of washing, papermaking, water needling, etc., it is more preferable from the viewpoint of wastewater treatment and safety to human bodies. Aqueous emulsions include emulsifiers for dispersion, antistatic agents, leveling agents, rust inhibitors, fungicides, antibacterial agents, flame retardants, antioxidant agents, inorganic additives such as titanium oxide and silicon, and fibers. A treatment agent such as an anionic, cationic or nonionic surfactant, a fatty acid ester, or a lubricant such as a mineral oil may be contained as long as the hydrophilic durability is not impaired.

The fibers having the treatment agent adhered thereto are then subjected to a heat treatment to be fixed. At this time, if the heat treatment temperature is too low, the crosslinking and curing reaction of the treatment agent film becomes insufficient, and even if the hydrophilicity is excellent, the durability becomes insufficient and the object of the present invention is hardly achieved, while If it is too high, the hydrophilicity tends to be insufficient, so that the range of 110 to 145 ° C is appropriate. If the heat treatment time is shortened, the crosslinking and curing reaction of the treatment agent film becomes insufficient and the durability tends to decrease. Therefore, it is preferable that the heat treatment time be 10 minutes or more in the above temperature range.

The hydrophilic polyester fibers obtained by the production method of the present invention described above can be cut into short fibers after crimping according to the intended use. For example, when applied to applications such as dry nonwoven fabric, fiber structure, and spun yarn, the number of crimps is 3 to 40/25 mm, and the crimp ratio is 3 to 4.
Suitably a crimp of 0% is provided. 3 crimps /
If the crimping ratio is less than 25 mm or less than 3%, the entanglement between short fibers is insufficient, and the passing property through the card is insufficient. On the other hand, when the number of crimps exceeds 40 pieces / 25 mm or the crimp rate exceeds 30%, the entanglement between short fibers becomes too large, so that carding cannot be performed sufficiently with a card. This is not preferable because the quality of the web or sliver is significantly impaired. A particularly preferred range of crimp is when the number of crimps is 5 to 3
0/25 mm, crimp rate is 5 to 30%. The form of crimping may be appropriately selected and set from either mechanical crimping or three-dimensional crimping according to the application and purpose.

On the other hand, when used for wet nonwoven fabric,
Depending on the purpose of the product, it may or may not be crimped.However, in order to give the nonwoven fabric bulkiness and stretchability, mechanical crimping and three-dimensional crimping are provided within the range that does not impair wet moldability can do.

The fineness and fiber length of the fiber according to the present invention may be arbitrarily selected according to the application. The polyester fiber targeted by the present invention does not need to be composed of 100% polyester. If the fiber surface is composed of polyalkylene terephthalate polyester, the core-sheath type and the eccentric core-sheath type are used. It may be a composite fiber having another polymer such as a sea-island type, split type or the like inside the fiber.

[0032]

The present invention will be described more specifically with reference to the following examples. The methods for evaluating various physical properties described in the examples are as follows.

(A) Amount of treatment agent attached At the time of stretching, the consumption y (g) of the aqueous emulsion having an emulsion concentration of c (% by weight) was measured. It measured using the formula. Treatment agent adhesion amount (% by weight) = c × y / d

(B) Initial hydrophilicity 1 g of the opened short fiber sample was uniformly filled in a capsule having a diameter of 25 mm and a length of 25 mm (total mass: 2 g), and placed in a 1 liter beaker filled with water to a height of 12 cm. The capsule was dropped and the number of seconds of falling to the bottom was measured. The smaller the number of seconds, the better the hydrophilicity.

(C) Hydrophilic durability After washing in accordance with JIS L 0217 Appendix (1) No. 103 of washing method, the number of seconds to fall to the bottom is measured according to the method described in (b) Initial hydrophilicity. . If this operation is repeated and the number of repetitions when the number of seconds falling to the bottom exceeds 60 seconds for the first time is n, (n−
1) The number of times is defined as the hydrophilic durability of the fiber. The higher the value of (n-1), the better the hydrophilic durability.

(D) Intrinsic viscosity (IV) It was measured at a temperature of 35 ° C. using orthochlorophenol as a solvent.

(E) Yellowing Degree A short fiber to be measured was used as a card web, and before and after a heat treatment for 10 minutes in air at 180 ° C., a comparison was made by visual observation. ：: No yellowing is observed. Δ: Appears slightly yellowish. X: Yellowing is clearly observed.

(F) Card Passability A short fiber sample was passed through a roller card, and web spots and cylinder winding were evaluated as poor (x), and other cases were evaluated as good (o).

Examples 1 to 5 and Comparative Examples 1 to 6 Polyethylene terephthalate having an intrinsic viscosity of 0.64 was melted at 290 ° C., and 750 g / min using a spinneret having a hole diameter of 0.3 mm and 1,300 holes. Discharge at discharge rate, take-off speed 1100
An undrawn yarn was obtained by melt spinning at m / min. After the obtained undrawn yarn was drawn 3.8 times, the treating agents shown in Table 1 were added to Table 1
Then, a mechanical crimp having a number of crimps of 13 pieces / 25 mm and a crimp rate of 12% was applied by an indentation crimping device. Subsequently, the fibers were subjected to relaxation heat treatment in hot air at 135 ° C. for 50 minutes to obtain short fibers having a fineness of 1.5 dtex and a fiber length of 44 mm. Table 2 shows the evaluation results.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

The hydrophilic polyester fiber obtained according to the present invention can be used to obtain a product exhibiting good hydrophilicity even after being subjected to a wet molding process such as washing, papermaking or water needling. It has excellent durability and excellent hydrophilicity, and is of great industrial value.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06M 13/328 D06M 13/328 15/507 101: 32 // D06M 101: 32 15/507 (72) Invention Person Shoji Makino 77, Kitayoshida-cho, Matsuyama-shi, Ehime Pref. In the Matsuyama Office of Teijin Limited (72) Inventor Shinichi Takahashi 77, Kitayoshida-cho, Matsuyama-shi, Ehime F-term in the Matsuyama Office of Teijin Limited 4J002 CD01W CF10X CH05Y GK02 HA07 4L033 AA07 AC07 BA08 CA45 CA48

Claims (6)

[Claims] 1. An aliphatic polyepoxy compound (A) having two or more epoxy groups in a molecule, comprising 40 to 95% by weight.
A polyether polyester copolymer (B) occupied by a polyalkylene glycol component and a treating agent containing 0.1 to 5.0% by weight based on the weight of the fiber, A method for producing a hydrophilic polyester-based fiber having excellent durability, which is fixed by heat treatment. 2. The method according to claim 1, wherein the treating agent contains a polyoxyalkylene alkyl tertiary amine (C). 3. The aliphatic polyepoxy compound (A) having two or more epoxy groups in the molecule is polyethylene glycol diglycidyl ether.
A method for producing a hydrophilic polyester fiber having excellent durability according to the description. 4. A polyether polyester copolymer (B) comprising a terephthalic acid component and an isophthalic acid component and / or an alkali metal salt sulfoisophthalic acid component as a dicarboxylic acid component in a molar ratio of 40:60 to 100: 0 ( Terephthalic acid component: isophthalic acid component and / or alkali metal salt sulfoisophthalic acid component) and a polyalkylene glycol component having a number average molecular weight of 60
The method for producing a hydrophilic polyester fiber having excellent durability according to any one of claims 1 to 3, wherein the method is polyethylene glycol of 0 to 10,000. 5. The polyoxyalkylene alkyl tertiary amine (C) according to claim 2, wherein the oxyalkylene units in the tertiary amine (C) are oxyethylene units, and the total number of the units is 3 to 12. A method for producing a hydrophilic polyester fiber having excellent durability according to the description. 6. The method according to claim 5, wherein the alkyl group of the polyoxyethylene alkyl tertiary amine (C) has 10 to 22 carbon atoms.