JP2001123332A - Thermally adhesive conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a thermally adhesive conjugate fiber which has excellent thermal adhesivity to polyester fibers including polyethylene terephthalate fibers at low temperature, and can give a nonwoven fabric having a soft touch without generating a trouble caused by the thermally adhesive component on the production process. SOLUTION: This thermally adhesive conjugate fiber comprises a polyester and a copolyester comprising terephthalic acid component, a 6 to 12C aliphatic and/or alicyclic dicarboxylic acid component, isophthalic acid component, and trimethylene glycol component, wherein the copolyester is disposed so as to be exposed to at least the surface of the fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-adhesive conjugate fiber, and more particularly, to a heat-adhesive conjugate fiber,
Particularly, the present invention relates to a heat-adhesive conjugate fiber which has excellent heat-adhesive properties at low temperatures, has no trouble in its production and use steps, and can provide a product having excellent flexibility after heat-adhesion with polyester fibers.

[0002]

2. Description of the Related Art In recent years, in the use of non-woven fabrics, as the proportion of polyester fibers used as the constituent fibers has increased, polyester polymers having good heat adhesion to the polyester fibers have been used as heat-bonding components. Is desired.
Further, in the production of nonwoven fabrics and the like, from the viewpoint of production efficiency and energy saving, a method of bonding by a heat treatment at a relatively low temperature of 100 to 150 ° C. and for a short time is often used. There is a demand for a polyester-based heat-adhesive conjugate fiber.

[0003] In addition, troubles in the process of manufacturing the heat-adhesive conjugate fiber, such as fusion of chips or spinning in a cutter step when taking out a molten polymer from a polymerization tank and forming chips. There is no sticking between the heat-adhesive conjugate fibers in the process, trouble in the process of manufacturing a nonwoven fabric using this heat-adhesive conjugate fiber, for example, adhesion of the heat-adhesive conjugate fiber to the device during the heat bonding process, It is also required that no fusion occurs.

In order to satisfy these requirements, Japanese Patent Publication No.
No. 0926 proposes a fiber using an amorphous copolymerized polyester as the heat bonding component. But,
Although the fiber has a sufficient performance in terms of thermal adhesiveness, it has not been able to solve the above-mentioned troubles in the fiber manufacturing process and the nonwoven fabric manufacturing process to a satisfactory degree.

In order to solve these problems, Japanese Patent Laid-Open No.
JP-A-34327 proposes a heat-adhesive conjugate fiber obtained by adding an aliphatic dicarboxylic acid to a copolyester to form a heat-adhesive component. The fiber eliminates the problems of heat adhesion, adhesion and fusion, and can reduce problems in the nonwoven fabric manufacturing process.However, the resulting nonwoven fabric has a slightly harder texture and requires softness. For example, it was difficult to apply to sanitary materials and the like.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester resin such as polyethylene terephthalate which has excellent thermal adhesion at low temperatures and causes troubles in the production process due to the thermal adhesive component. It is an object of the present invention to provide a heat-adhesive conjugate fiber that can provide a nonwoven fabric having a soft feel without any problem.

[0007]

The present inventor has conducted intensive studies in view of the above prior art in order to achieve the above object,
Composite fibers with a specific copolyester as a heat-adhesive component are heat-adhesive and manufactured, process stability during use,
The present inventors have found that the nonwoven fabric is excellent in both texture and texture, and have completed the present invention.

That is, an object of the present invention is to provide at least one polyester selected from the group consisting of polyethylene terephthalate polyester, polytrimethylene terephthalate polyester, and polybutylene terephthalate polyester, and a copolymerized polyester.
A thermobonding, wherein the copolyester is a composite fiber arranged to be exposed at least on the fiber surface, wherein the copolyester simultaneously satisfies the following requirements (a) to (d): This can be achieved by a composite conjugate fiber.

(A) 50% of terephthalic acid component based on all dicarboxylic acid components constituting the copolymerized polyester
Occupies ~ 90 mol%. (B) The aliphatic and / or alicyclic dicarboxylic acid component having 6 to 12 carbon atoms occupies 0 to 5 mol% based on all dicarboxylic acid components constituting the copolymerized polyester. (C) The isophthalic acid component and the constituent carbon number of 6-1 are based on all dicarboxylic acid components constituting the copolymerized polyester.
(2) the sum with the aliphatic and / or alicyclic dicarboxylic acid component accounts for 10 to 50 mol%. (D) 90 mol% of trimethylene glycol component based on all glycol components constituting copolymerized polyester
Occupy the above.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The requirements (a) to (d) that the copolymerized polyester of the present invention should satisfy will be described. In the copolymerized polyester of the present invention, it is necessary that the terephthalic acid component accounts for 50 to 90 mol% based on all dicarboxylic acid components constituting the copolymerized polyester. When the content of the terephthalic acid component is less than 50 mol%, the resulting polymer or fiber is likely to fuse and stick. On the other hand, if it exceeds 90 mol%, the texture becomes hard,
Adhesion is also reduced.

If the content of the aliphatic dicarboxylic acid having 6 to 12 carbon atoms exceeds 5 mol%, fusion of the polymer chips,
Alternatively, the resulting heat-adhesive conjugate fibers tend to stick together, causing troubles in the chipping step and the fiber manufacturing step, and furthermore, sticking and fusing to the device in the nonwoven fabric manufacturing step, which is not preferable. The amount of the aliphatic dicarboxylic acid is preferably at most 4 mol%, more preferably at most 3 mol%. Further, when the number of constituent carbon atoms is less than 6, the thermal adhesion at low temperatures is lowered, and when it exceeds 12, adhesion of polymer chips, sticking of fibers, and sticking and fusing to equipment in a nonwoven fabric manufacturing process occur, which is unsuitable. It is.

The aliphatic and / or alicyclic dicarboxylic acids having 6 to 12 carbon atoms include adipic acid, heptane diacid, octane diacid, azelaic acid, sebacic acid, undecandioic acid and dodecane diacid. Examples include aliphatic dicarboxylic acids such as acids, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and dicyclohexanedimethylenedicarboxylic acid. Of these, adipic acid and sebacic acid are particularly preferred in terms of cost.

When the sum of the isophthalic acid component and the aliphatic and / or alicyclic dicarboxylic acid component having 6 to 12 carbon atoms is less than 10 mol% based on all dicarboxylic acid components constituting the copolymerized polyester. If it is, the heat adhesion is undesirably reduced. On the other hand, if the content exceeds 50 mol%, the cost is disadvantageous, and the copolyester chips and the resulting heat-adhesive conjugate fibers are easily fused. The sum of the isophthalic acid component and the aliphatic and / or alicyclic dicarboxylic acid component having 6 to 12 carbon atoms is 12 mol%.
It is preferably at least 14 mol%, more preferably at least 14 mol%.

Further, in the copolymerized polyester of the present invention, it is necessary that the trimethylene glycol component accounts for 90 mol% or more based on all glycol components constituting the copolymerized polyester. If the trimethylene glycol component is less than 90 mol%, the flexibility is undesirably reduced. The preferred range of the trimethylene glycol component is 95 mol% or more.

The intrinsic viscosity (measured in an orthochlorophenol solvent at 30 ° C.) of the copolymerized polyester of the present invention is as follows:
It is preferably from 0.40 to 1.00. When the intrinsic viscosity is lower than 0.40, the mechanical properties of the copolymerized polyester are reduced, and the strength of the finally obtained heat-bonded product such as a nonwoven fabric tends to be insufficient. On the other hand, if it is higher than 1.00, the fluidity of the polymer tends to decrease, and the thermal bonding performance tends to decrease. The intrinsic viscosity of the copolymerized polyester is preferably in the range of 0.45 to 0.90, more preferably 0.50 to 0.90.
A range of 80 is more preferred.

The copolymerized polyester of the present invention is in a range not impairing its properties, preferably in a range of 5 mol% or less, a terephthalic acid component, an isophthalic acid component, an aliphatic dicarboxylic acid component, an alicyclic dicarboxylic acid component, and trimethylene glycol. Components other than the components may be copolymerized, for example, naphthalenedicarboxylic acid, orthophthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfondicarboxylic acid, benzophenonedicarboxylic acid, phenylindanedicarboxylic acid, metal 5-sulfoxyisophthalate Salts, aromatic dicarboxylic acids such as phosphonium 5-sulfoxyisophthalate, ethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene Recol, neopentylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, aliphatic glycols such as polytetramethylene glycol, alicyclic glycols such as cyclohexanediol and cyclohexanedimethanol, o-xylylene glycol, m-xylylene Glycol, p-xylylene glycol, 1,4-bis (2-
(Hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxyethoxy) benzene, 4,4′-bis (2-hydroxyethoxy) biphenyl, 4,4′-bis (2-hydroxyethoxyethoxy) biphenyl,
2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, 2,2-bis [4- (2-hydroxyethoxyethoxy) phenyl] propane, 1,3-bis (2-hydroxyethoxy) benzene, 1,3-bis (2-hydroxyethoxyethoxy) benzene, 1,2
-Bis (2-hydroxyethoxy) benzene, 1,2-
Bis (2-hydroxyethoxyethoxy) benzene,
Aromatic glycols such as 4,4'-bis (2-hydroxyethoxy) diphenylsulfone and 4,4'-bis (2-hydroxyethoxyethoxy) diphenylsulfone, hydroquinone, 2,2-bis (4-hydroxyphenyl)
And diphenols such as propane, resorcin, catechol, dihydroxynaphthalene, dihydroxybiphenyl and dihydroxydiphenylsulfone. These may be used alone or in combination of two or more.

The above-mentioned copolymerized polyester can be produced by a conventionally known method. For example, the dicarboxylic acid component is subjected to an esterification reaction with trimethylene glycol, or the lower alkyl ester component of the dicarboxylic acid is subjected to a transesterification reaction with trimethylene glycol in the presence of a transesterification catalyst to obtain a bisglycol ester and / or The initial condensate is obtained and then subjected to a polycondensation reaction in the presence of a polycondensation catalyst, or the isophthalic acid, aliphatic dicarboxylic acid and / or trimethylene glycol ester thereof used as a copolymerization component is combined with a terephthalic acid component. A method can be employed in which the polycondensation reaction is carried out in the presence of a polycondensation catalyst by adding to the bisglycol ester with trimethylene glycol and / or its prepolymerized product.

In the copolymerized polyester used in the present invention, a small amount of additives such as a lubricant, a pigment,
Dyes, antioxidants, solid-state polymerization accelerators, optical brighteners, antistatic agents, antibacterial agents, ultraviolet absorbers, light stabilizers, heat stabilizers,
It may contain a light-shielding agent, a matting agent, and the like.

The heat-adhesive conjugate fiber of the present invention is a composite comprising at least one polyester selected from the group consisting of polyethylene terephthalate-based polyester, polybutylene terephthalate-based polyester and polytrimethylene terephthalate-based polyester, and the above-mentioned copolymerized polyester. Fiber.

The term "polyethylene terephthalate-based polyester" as used herein means that the number of repeating units of ethylene terephthalate is 90% based on all repeating units of the polyester.
The polytrimethylene terephthalate-based polyester is at least 90 mol%, preferably at least 9 mol%, preferably at least 95 mol%, based on all repeating units of the polyester.
The polybutylene terephthalate-based polyester of 5 mol% or more refers to a polyester in which the butylene terephthalate repeating unit accounts for 90 mol% or more, preferably 95 mol% or more, based on all repeating units of the polyester. In these polyesters, another copolymer component may be copolymerized as long as the properties of the polyester itself are not impaired.

The intrinsic viscosity of polyethylene terephthalate-based polyester, polytrimethylene terephthalate-based polyester, and polybutylene terephthalate-based polyester used in the heat-adhesive conjugate fiber of the present invention is generally 0. .50-1.0
0 is used.

In the heat-adhesive conjugate fiber of the present invention, the copolymerized polyester disposed as an adhesive component needs to be exposed at least on the surface of the conjugate fiber, and 40% of the surface is exposed.
It is preferable that it is exposed so as to occupy the above.
If the copolymerized polyether is not exposed on the surface of the composite fiber, the adhesive effect cannot be obtained, which is inappropriate. In addition,
The area ratio of the copolyester in an arbitrary cross section of the conjugate fiber is preferably 10 to 70%, more preferably 3%.
It is 0 to 70%, particularly preferably 30 to 50%.

As the composite fiber having such a composite form, core-sheath type composite fiber, eccentric core-sheath type composite fiber, side-by-side type composite fiber and the like can be adopted. In the case of a core-sheath type composite fiber, a copolymerized polyester is disposed as a sheath component, and a polyethylene terephthalate-based polyester,
A core-sheath type composite fiber in which either polybutylene terephthalate polyester or polytrimethylene terephthalate polyester is disposed as a core component is particularly preferable. In the case of using a copolymer polyester as a core component in the case of a core-sheath type conjugate fiber, it is necessary to provide an eccentric type so that the core component is exposed at least on the fiber surface. Furthermore, it can be preferably used also as a side-by-side type composite fiber.

The heat-adhesive conjugate fiber of the present invention may be formed into a nonwoven fabric after being formed into an aggregate of the heat-adhesive conjugate fiber alone, but usually contains the heat-adhesive conjugate fiber in an amount of 10% by weight or more. After forming a mixed fiber aggregate with other fibers, it is used as a nonwoven fabric.

The heat-adhesive conjugate fiber of the present invention is suitable for use in producing a nonwoven fabric by heat-bonding polyester fibers. Can also be widely used.

[0026]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The parts in the examples are parts by weight. Various properties were evaluated by the following methods. (1) Intrinsic viscosity [η]: Measured at 30 ° C. using orthochlorophenol as a solvent, and determined from the relative viscosity by an ordinary method. (2) Adhesive strength: The tensile strength at break was measured at a grip interval of 10 cm and an elongation speed of 20 cm / min according to the method described in JIS L1096. The adhesive strength was a value obtained by dividing the tensile breaking strength by the weight of the test piece. (3) Chip fusion: When the polymer did not fuse with each other when cutting the polymer with a chip cutter,
The case where even a little fusion occurred was indicated by x. (4) Adhesion of fibers: を indicates that no adhesion occurred between the fibers during spinning and / or drawing of the heat-adhesive conjugate fiber,
The case where even a little sticking occurred was indicated by x. (5) Adhesion to non-woven fabric manufacturing equipment: In the non-woven fabric manufacturing process, "○" indicates that no adhesion or fusion of the heat-adhesive conjugate fiber to the production equipment occurred, and "X" indicates that slight adhesion or fusion occurred. Indicated.

Example 1 Dimethyl terephthalate 60
Reaction, 38 parts of dimethyl isophthalate, 2.37 parts of dimethyl sebacate, 54.9 parts of trimethylene glycol and 0.078 part of titanium tetrabutoxide as a catalyst, provided with a stirrer, a rectification column and a methanol distillation condenser. The mixture was charged into a vessel, and the temperature was gradually raised from 140 ° C., and transesterification was carried out while distilling methanol produced as a result of the reaction out of the system. 3 hours after the start of the reaction, the internal temperature was 210
° C was reached.

Next, the obtained reaction product was transferred to another reactor equipped with a stirrer and a glycol distilling condenser, and the temperature was gradually raised from 210 ° C. to 265 ° C., and the pressure was reduced from normal pressure to a high vacuum of 70 Pa. The polymerization reaction was performed while reducing the pressure. The melt viscosity of the reaction system is tracked and the intrinsic viscosity [η]
Was reached when the polymerization reaction reached 0.65.

The molten polymer was extruded from the bottom of the reactor into strands in cooling water, and cut into chips using a strand cutter. Chip fusion did not occur at all, and the processability in the cutter process was extremely good.

The obtained copolymerized polyester is used as a sheath component, and polyethylene terephthalate having an intrinsic viscosity of 0.64 is used as a core component, and melted and discharged from a core-sheath type composite spinneret at a sheath / core = 50/50 (weight ratio). It was withdrawn at a speed of 800 m / min. At this time, the melting temperature of the sheath component was 240 ° C, and the melting temperature of the core component was 280 ° C.

The obtained unstretched yarn was stretched at a stretching temperature of 60 ° C. and a stretching ratio of 3.0 to give a crimp having a crimp rate of 10%. Next, the obtained crimped yarn was cut into a length of 51 mm to obtain a heat-adhesive conjugate short fiber of 10 dtex (9 de).

The area ratio of the copolyester in the cross section of the fiber was 50%, and there was no sticking between the fibers during spinning and drawing, and the fiber could be manufactured stably.

20 parts by weight of this heat-adhesive composite short fiber and polyethylene terephthalate short fiber 8 having a cut length of 51 mm
And 0 parts by weight, and heat-bonded at 130 ° C. to obtain a nonwoven fabric. The heat-adhesive conjugate fiber did not stick to the device during the production of the nonwoven fabric, and the processability was good. The adhesive strength of the obtained nonwoven fabric was 195 N / g. The above results are summarized in Tables 1 and 2.

[Examples 2 to 5, Comparative Examples 1 and 2]
, A similar operation was performed except that the composition of the copolymerized polyester was changed as shown in Table 1, to obtain a copolymerized polyester, a heat-adhesive conjugate fiber and a nonwoven fabric. The results were as shown in Table 2, but in Comparative Example 1, chips and fibers were stuck and could not be evaluated.

[0035]

[Table 1]

[0036]

[Table 2]

Example 6 and Comparative Example 3 The same operation as in Example 1 was carried out except that the spinneret was changed to a side-by-side type and a side-by-side type conjugate fiber was used. Fibers and nonwovens were obtained. The results were as shown in Tables 3 and 4.

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

The heat-adhesive conjugate fiber of the present invention has excellent heat-adhesive performance at low temperature to polyester fibers such as polyethylene terephthalate and, at the same time, forms a copolyester as a heat-adhesive component into chips. In this case, the chips are not fused, the fibers do not stick in the spinning and drawing process, and furthermore, they are not stuck to the device during the production of the nonwoven fabric, and are not stuck and fused, and can be stably produced and used. The obtained nonwoven fabric has an excellent texture and can be usefully used for a wide range of nonwoven fabric applications.

Claims (6)

[Claims] 1. A polyester comprising at least one polyester selected from the group consisting of polyethylene terephthalate-based polyester, polytrimethylene terephthalate-based polyester, and polybutylene terephthalate-based polyester, and a copolymerized polyester, the copolymerized polyester having at least a fiber surface. Wherein the copolymerized polyester is arranged so as to be exposed to
A heat-adhesive conjugate fiber which simultaneously satisfies the requirements of (d). (A) 50 to 90 mol% of a terephthalic acid component based on all dicarboxylic acid components constituting the copolymerized polyester
Occupy. (B) The aliphatic and / or alicyclic dicarboxylic acid component having 6 to 12 carbon atoms occupies 0 to 5 mol% based on all dicarboxylic acid components constituting the copolymerized polyester. (C) The isophthalic acid component and the constituent carbon number of 6-1 are based on all dicarboxylic acid components constituting the copolymerized polyester.
(2) the sum with the aliphatic and / or alicyclic dicarboxylic acid component accounts for 10 to 50 mol%. (D) 90 mol% of trimethylene glycol component based on all glycol components constituting copolymerized polyester
Occupy the above. 2. The copolymerized polyester has an intrinsic viscosity of 0.4.
The heat-adhesive conjugate fiber according to claim 1, which has a molecular weight of 1.0. 3. The heat-adhesive conjugate fiber according to claim 1, wherein the conjugate fiber is a core-sheath conjugate fiber in which a polyethylene terephthalate-based polyester is disposed in a core component and a copolymer polyester is disposed in a sheath component. 4. The conjugate fiber according to claim 1, wherein the core component is a polytrimethylene terephthalate-based polyester and the sheath component is a co-polyester.
The heat-adhesive conjugate fiber according to the above. 5. The heat-adhesive conjugate fiber according to claim 1, wherein the conjugate fiber is a core-sheath conjugate fiber in which a polybutylene terephthalate-based polyester is disposed in a core component and a copolymer polyester is disposed in a sheath component. 6. The heat-adhesive conjugate fiber according to claim 1, wherein the conjugate fiber is a side-by-side type conjugate fiber.