KR102460871B1 - Hygienic Non-woven Soft Thermal Bonding Compound Fiber - Google Patents

Abstract

The present invention is a soft heat-adhesive composite fiber for sanitary material non-woven fabric, wherein the composite fiber is a polyester-based resin as a first component and a polyolefin-based resin having a melting point lower than that of the polyester-based resin by 20° C. or more as a second component. Doedoe formed in a core type, wherein the polyester-based resin is a mixture of 30 to 95% by weight of the first polyester-based resin and 5 to 70% by weight of the second polyester-based resin, and the first polyester-based resin is an aromatic dicarbonate. It is one or a mixture of two or more selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate as a polycondensate of levonic acid and glycol, and the second polyester-based The resin esterifies diol and dicarbonic acid, which are raw materials for the hard segment, and polyol, which is a raw material for the soft segment, is polycondensed with the reaction product, wherein the diol is 1,4-butanediol. (1,4-BD) or a mixture of 1,4-butanediol (1,4-BD) and 2-methyl 1,3-propanediol (MPO), wherein the dicarbonic acid is dimethyl tere It is either phthalate (DMT) or dimethyl isophthalate (DMI), or it is composed of a mixture of an anhydride resin in any one composition, and the polyol is poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) and polypropylene glycol (PPG) relates to a soft heat-adhesive composite fiber for non-woven sanitary material characterized in that it is composed of any one.

Description

Hygienic Non-woven Soft Thermal Bonding Compound Fiber

The present invention relates to a soft heat-adhesive composite fiber for sanitary material non-woven fabric to which a technology that does not fluoresce and emit UV light is applied.

Low-density non-woven fabric with a fabric density of 10 to 45 g/m2 is used as a surface material for paper diapers and sanitary napkins. As the use of the nonwoven fabric is diversified, the properties required for the nonwoven fabric also become strict, and there has been a demand for a nonwoven fabric having high strength while maintaining a soft touch.

In order to meet these demands, a composite fiber that is fine and has heat-adhesive properties and that has a low melting point component not only provides sufficient heat-adhesive strength but also provides flexibility is needed.

Conventionally, a cis-core type or side-by-side type composite fiber in which a polyolefin-based component such as polyethylene or polypropylene is used as a low-melting component and a polyolefin-based component such as polyester such as polyethylene terephthalate and polypropylene is used as a high-melting component. is well known in the past.

For example, U.S. Patent No. 5,866,488 discloses that the first component is polyethylene and the second component is polyester, wherein the polyethylene continuously occupies at least a portion of the fiber surface in the longitudinal direction and has 1.5 atoms/1000 carbon atoms in its molecular chain. A heat-sealable composite fiber having the following methyl branches, a density of 0.940 to 0.965 g/cm 3 , and a Q value (weight average molecular weight/number average molecular weight) of 4.8 or less is proposed.

In addition, U.S. Patent No. 5,798,305 discloses polypropylene or a high-melting component made of polypropylene and a low-melting component made of polyethylene, and the polyethylene continuously forms at least a part of the fiber surface in the fiber direction and has 0 to 1.5 methyl A hot melt adhesive composite fiber having a branch/carbon number of 1000, a density of 0.950 to 0.965 g/cm 3 , and a Q value (weight average molecular weight/number average molecule) of 4.5 or less is proposed.

In addition, as the performance of nonwoven fabrics used in sanitary materials such as sanitary napkins and diapers is diversified, functions such as high elasticity, high bulkiness, and high water absorption/water repellency are emphasized. Non-woven fabrics for sanitary materials use visible color-based non-woven fabrics to emphasize the liquid permeation and absorption functions. products are also being developed. However, in the case of Asian regions, including Korea, Japan, and China, fluorescent whitening agents are recognized as environmental hormones and their use in hygiene products is strictly prohibited.

Even in the case of polyester-based resins that do not contain fluorescent substances, the use of fibers made of polyester is limited due to fluorescence due to molecular structure.

Accordingly, the present inventors have come to develop a heat-adhesive composite fiber suitable for use as a sanitary material by suppressing the fluorescence of polyester in a heat-adhesive composite fiber containing one or more components of a polyester-based resin.

The present invention's soft heat-adhesive composite fiber for sanitary material non-woven fabric was invented to solve the problems of the prior art of UV fluorescence and light emission, and a UV absorber component that can block UV in the core of the conventional sheath-score composite fiber. An object of the present invention is to provide a heat-adhesive composite fiber containing

In order to solve the above problems, the present invention provides a soft heat-adhesive composite fiber for a sanitary material nonwoven fabric, wherein the composite fiber has a polyester-based resin as a first component and a second component, and has a melting point of 20°C than that of the polyester-based resin. It is formed in a sheath-core type with a low polyolefin-based resin, and the polyester-based resin is a mixture of 30 to 95% by weight of the first polyester-based resin and 5 to 70% by weight of the second polyester-based resin, 1 The polyester-based resin is a polycondensate of aromatic dicarboxylic acid and glycol. One or a mixture of two or more selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate. And, the second polyester-based resin is a hard segment raw material diol (Diol) and dicarbonic acid (Dicarbonic acid) esterification reaction, the reaction product is polyol (Polyol) soft segment raw material doedoe polycondensation, the diol ( Diol) is composed of 1,4-butanediol (1,4-BD) or a mixture of 1,4-butanediol (1,4-BD) and 2-methyl 1,3-propanediol (MPO), The main acid (Dicarbonic acid) is either dimethyl terephthalate (DMT) or dimethyl isophthalate (DMI), or is composed of a mixture of an anhydride resin mixed with any one composition, and the polyol (Polyol) provides a soft heat-adhesive composite fiber for sanitary material non-woven fabric, characterized in that it is composed of any one of poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) and polypropylene glycol (PPG).

In addition, the present invention provides a soft heat-adhesive composite fiber for sanitary material non-woven fabric, characterized in that the composite fiber is in the form of one circle or two to four circles attached in a line, and the core is square or circular.

The present invention also provides a soft heat-adhesive composite fiber for sanitary material non-woven fabric, characterized in that the composite fiber has a weight ratio of 80:20 to 20:80 of the first component and the second component.

As described above, the soft heat-adhesive composite fiber for sanitary material non-woven fabric according to the present invention contains TiO ₂ in the core portion, thereby having an effect of not fluorescing and not emitting UV light.

In addition, the core part contains a polyester component that increases flexibility, so that the bending rigidity of the composite fiber is lowered, so that the soft touch feeling is improved when used as a nonwoven fabric.

1 is a photograph showing whether fluorescence was measured in Examples and Comparative Examples of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. First, in describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the gist of the present invention.

As used herein, the terms 'about', 'substantially' and the like are used in or close to the numerical value when manufacturing and material tolerances inherent in the stated meaning are presented, and provide an understanding of the present invention. To help, precise or absolute figures are used to prevent unfair use by unscrupulous infringers of the stated disclosure.

As used herein, the terms about, substantially, etc., are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to be precise or to aid in the understanding of the present invention. Absolute figures are used to prevent unreasonable exploitation of the stated disclosure by unscrupulous infringers.

The present invention relates to a soft heat-adhesive composite fiber for sanitary material non-woven fabric, comprising: 45 to 85 weight ratio of a first polyester-based resin as a core part, which is a first component of the composite fiber; The UV absorber is composed of 0.1 to 5 weight ratio and the second polyester-based resin is 10 to 50 weight ratio, and the sheath part of the second component is composed of a low melting point polyester resin.

The first polyester-based resin is a polycondensate of aromatic dicarboxylic acid and glycol, and as the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc. may be used, and the glycol is ethylene glycol, 1, 3-propanediol, 1,4-butanediol, etc. can be used.

Or the first polyester-based resin is a polycondensate of aromatic dicarboxylic acid and glycol, one selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, or Mixtures of two or more may be used.

Preferably, polyethylene terephthalate may be used, and it will be preferable to use a polyester-based resin having an intrinsic viscosity (IV) of 0.50 to 0.80 dL/g measured according to ASTM 02857.

The second polyester-based resin is an esterification reaction of diol and dicarbonic acid, which are hard segment raw materials, and polyol, a soft segment raw material, is polycondensed with the reaction product,

The diol may be composed of 1,4-butanediol (1,4-BD) or a mixture of 1,4-butanediol (1,4-BD) and 2-methyl 1,3-propanediol (MPO), ,

The dicarbonic acid may be any one of dimethyl terephthalate (DMT) or dimethyl isophthalate (DMI), or a mixture in which an anhydride resin is mixed with any one of the compositions.

The polyol (Polyol) is characterized in that it may be composed of any one of poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) and polypropylene glycol (PPG).

The dimethyl isophthalate (DMI) is a structural isomer of dimethyl terephthalate (DMT) and exhibits the same effect although it is expensive.

In addition, the anhydride resin is methyl tetrahydrophthalic anhydride (MeTHPA), methyl hexahydrophthalic anhydride (MeHHPA), terahydrophthalic anhydride (THPA) and hexahydrophthalic anhydride. It can be composed of a mixture in which any one or more of hydride (HHPA) is added,

The polyol (Polyol) may be composed of any one of poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG), or polypropylene glycol (PPG).

In addition, although an anhydride resin of the dicarbonic acid may be used directly as a starting material for the esterification reaction, conjugated diene having two double bonds and maleic anhydride A product through Diels-Alder reaction of maleic anhydride may also be used.

First, the esterification reaction is described with respect to the method for producing the polyester-based elastic adhesive resin composition. A low molecular weight diol component of butylene glycol of 1,4-butanediol (1,4-BD) and dimethyl terephthalate to form a hard segment. (DMT) and esterification reaction.

As for the reaction capacity, the mole fraction of dicarbonic acid and diol is added in a ratio of 1 to 1.0 to 1.5, and the excess diol component is mostly recovered through a reduced pressure process during the polycondensation reaction, and dicarboxylic acid (Dicarbonic acid) and diol (Diol) have a value of 30 to 90% by weight of the total second polyester-based resin.

In addition, the mixture of 1,4-butanediol (1,4-BD) and 2-methyl 1,3-propanediol (MPO) contains 70 to 95 mol% of 1,4-butanediol (1,4-BD) and 5 ~30 mole % of 2-methyl 1,3-propanediol (MPO) can be used. Here, when a certain amount of 2-methyl 1,3-propanediol (MPO) is added, a tendency to decrease the hardness of the polyester-based elastic adhesive resin occurs, thereby increasing the property of restoring it to its original state.

In addition, the mixture of dimethyl terephthalate (DMT) and anhydride resin may be composed of 80 to 95 mol% of dimethyl terephthalate (DMT) and 5 to 20 mol% of anhydride resin. .

In addition, the anhydride resin may have a molar ratio of methyl terahydrophthalic anhydride (MeTHPA) and methyl hexahydrophthalic anhydride (MeHHPA) of 4 to 6 to 6 to 4.

Conventionally, in order to control the melting point of the polyester-based elastic adhesive resin without using only dimethyl terephthalate (DMT), aromatic or aliphatic ticarboxylic acids such as isophthalic acid, adipic acid, and succinic acid were used as copolymer raw materials.

Methyl tetrahydrophthalic anhydride (MeTHPA), methyl hexahydrophthalic anhydride (MeHHPA), terahydrophthalic anhydride (THPA) and hexahydrophthalic anhydride as anhydride resins When any one or more of (HHPA) is added to terephthalate (DMT), it is possible to easily control the melting point required in various ways in the molding process of the final product while maintaining the elastic and physical properties, which are important properties of the present invention. have an advantage

Substantially, even if a small amount of methyl tetrahydrophthalic anhydride (MeTHPA) is added, a melting point lowering phenomenon occurs, and the effect of a drop of about 4°C per mole can be obtained, and methyl tetrahydrophthalic anhydride (MeTHPA), methyl When hexahydrophthalic anhydride (MeHHPA) is mixed and used in a molar ratio of 4 to 6 to 6 to 4, the lowering of the melting point occurs more significantly.

For example, when an anhydride (MeTHPA) is used alone, when it is used in combination, the effect of lowering the melting point is greater by about 5° C. per mole of the mixture.

The catalyst used in the esterification reaction is selected from the group consisting of zinc acetate, sodium acetate, magnesium acetate, tetranomalbutoxytitanate, tetraisopropyltitanate, titanium oxide/siloxide microcopolymer, and nanotitanate. It is used in the range of 50 to 1000 ppm based on 100 parts by weight of the polyester-based elastic adhesive resin. If the amount of catalyst is insufficient, the esterification reaction rate is slowed, and if excessive, the thermal stability of the polyester-based elastic adhesive resin is reduced. it gets worse

After the esterification reaction, polycondensation is performed.

The oligomer solution obtained by the esterification reaction and the soft segment polyol, together with a polycondensation catalyst, a heat stabilizer, and a photooxidation stabilizer, are put into a pressure-resistant and heat-resistant reactor capable of vacuum decompression, and then a pressure of 760 to 1000 Torr and 200 After distillation of excess diol (Doil) at a temperature of ~270 ℃, to complete the polycondensation under a high vacuum of 1mmHg or less final vacuum degree to obtain a second polyester-based resin.

Here, the polyol may be any one of poly(tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG), or polypropylene glycol (PPG), and the molecular weight of the polyol is 400 to 20000, and the polyether ester It contains 10 to 80% by weight compared to the system resin.

In addition, the polymerization catalyst used in the polycondensation step is one selected from the group consisting of antimony trioxide, antimony acetate, tetranormal butoxytitanate, tetraisopropyl titanate, titanium oxide/silica oxide microcopolymer, and nano titanate. Above, it can be used in the range of 50 to 2000 ppm based on 100 parts by weight of the polyester-based elastic adhesive resin.

As for the UV absorber, titanium dioxide (TiO2) is one of the materials widely used as an inorganic sunscreen. Titanium dioxide has a high refraction, so it has an excellent light scattering effect, and its fine particles have optical properties such as whiteness, hiding power and coloring power this is excellent

The second component is a sheath portion of the composite fiber and is composed of a low-melting-point polyester resin.

The low-melting polyester resin is an acid component consisting of terephthalic acid or an ester-forming derivative thereof, and 2-methyl-1,3-propanediol (2-Methyl 1,3 Prorpanediol), 2-methyl-1,3-pentanediol ( 2-Methyl 1,3 Pentanediol) and ethylene glycol (EG) are formed as a diol component.

The 2-methyl-1,3-propanediol of the low-melting polyester resin used in the present invention has a methyl group bonded to the second carbon to facilitate rotation of the polymer main chain, and acts as a polymer end portion to act as a free space between the main chains. By widening the space, the flowability of the entire molecular chain is increased. This makes the polymer amorphous and has the same thermal properties as isophthalic acid. Due to the flexible molecular chains present in the polymer main chain, it improves elasticity and thus improves the tear properties during binding of the nonwoven fabric.

That is, 2-methyl-1,3-propanediol is a methyl group on the ethylene chain bonded to terephthalate.

By including a group (-CH3) as a side chain to secure a space so that the main chain of the polymerized resin can rotate, it induces an increase in the degree of freedom of the main chain and a decrease in the crystallinity of the resin to induce a softening point (Ts) and/or a glass transition temperature (Tg) ) can be adjusted. This may exhibit the same effect as in the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to reduce the crystallinity of the conventional crystalline polyester resin.

The 2-methyl-1,3-pentanediol, like 2-methyl-1,3-propanediol, has a methyl group bonded to the second carbon to facilitate rotation of the polymer main chain and impart low melting point properties to the polyester resin. It has a characteristic of increasing the melt viscosity of the polyester resin with a longer molecular chain than 2-methyl-1,3-propanediol, and prevents the melt viscosity from rapidly lowering at high temperatures.

The low-melting-point polyester resin of the present invention formed of the diol component as described above contains 20 to 50 moles of 2-methyl-1,3-propanediol in the low-melting-point polyester resin in order to improve low melting point characteristics and adhesion. % would be preferable.

When the content of 2-methyl-1,3-pentanediol in the diol component is less than 0.01 mol%, the effect of improving the melt viscosity is insignificant, and when it exceeds 5 mol%, the melt viscosity rapidly increases and spinning processability may be deteriorated. 2-methyl-1,3-pentanediol may preferably contain 0.01 to 5 mol% of the diol component.

The content of 2-methyl-1,3-pentanediol is most preferably 0.05-2 mol%.

The low-melting-point polyester resin containing the 2-methyl-1,3-pentanediol was

The difference between the melt viscosity and the melt viscosity of 260° C. is 600 poise or less, and the melt viscosity does not decrease rapidly at high temperature.

The lower the difference between the melt viscosity of 220 °C and the melt viscosity of 260 °C of the low-melting polyester resin, the lower it is preferable, and it will be more preferably 500 poise or less.

As described above, the low-melting polyester resin of the present invention containing 2-methyl-1,3-propanediol and 2-methyl-1,3-pentanediol has a softening temperature of 100°C to 150°C, and a glass transition temperature of It has excellent physical properties at 50°C to 90°C and an intrinsic viscosity of 050 dL/g or more.

In addition, in the composite fiber, the first component and the second component may preferably be formed in a weight ratio of 80:20 to 20:80.

Hereinafter, examples of a method for producing a molded cross-section heat-adhesive composite fiber for a sanitary material nonwoven fabric according to the present invention are shown, but the present invention is not limited thereto.

Example 1

As the first component composition, 0.1wt% of UV absorber (TiO2) is contained in 89.9wt% of polyethylene terephthalate having an intrinsic viscosity of 0.64 dL/g, 50% by weight of a one-component composition containing 10wt% of the second polyester-based resin, and As a two-component composition, 50% by weight of a low-melting polyester resin was put into an extruder and melted.

The molten first and second component compositions were introduced into a conventional sheath-core soft composite spinning apparatus and then spun at a spinning speed of 800 m/min. The composite fiber spun at a temperature higher than the glass transition temperature of polyethylene terephthalate was stretched 3.0 to 4.0 times and cut to 38 to 64 mm by applying a crimp to prepare a soft heat-adhesive composite fiber according to the present invention.

Example 2

It was prepared in the same manner as in Example 1, except that the TiO2 component content in the first component was changed to 3wt%.

Example 3

It was prepared in the same manner as in Example 1, except that the TiO2 component content in the first component was changed to 5 wt%.

Example 4

It was prepared in the same manner as in Example 1, except that the TiO2 component content in the first component was changed to 3wt% and the flexible polyester-based component was changed to 20%.

Comparative Example 1

It was prepared in the same manner as in Example 1, but there was no TiO2 component in the first component, and 20% of the flexible polyester-based component was included.

Comparative Example 2

Prepared in the same manner as in Example 1, except that the first component consists only of the first polyester-based resin.

◈ Evaluation of physical properties of Examples and Comparative Examples

1. Physical property evaluation method

* Fluorescent

By irradiating a 5x5cm (25cm2) sample with a wavelength of 350 to 370 nm, the fluorescence is visually judged together with the comparative sample.

* Softness

The nonwoven fabric was manufactured in 20GSM standard using the fabricated fibers, and the score was converted into a 10-person emotional evaluation.

The softness of one specimen of Example and one specimen of Comparative Example having the same material composition and the same fineness was emotionally evaluated, and the score was converted into scores as many as selected from among 10 evaluators.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 1st component (50wt%) First polyester-based resin content 89.9 wt% 47wt% 45wt% 77 wt% 80 wt% 100wt% UV absorber) component (TiO2)
content 0.1wt% 3wt% 5 wt% 3wt% 0 wt% 0 wt% Second polyester-based resin content 10wt% 50wt% 10wt% 20wt% 20wt% 0 wt% 2 component (low melting point polyester resin) content 50wt% 50wt% 50wt% 50wt% 50wt% 50wt% UV fluorescence/luminescence doesn't exist doesn't exist doesn't exist doesn't exist radiation radiation softness 80 points 90 points 80 points 90 points 90 points 40 points

The features and other advantages of the present description as described above will become more apparent from the examples described below, and the following examples are only described for illustrative purposes and cannot be construed as limiting or limiting the protection scope of the present invention. .

Claims (4)

In the soft heat-adhesive composite fiber for sanitary material non-woven fabric,
The first component of the composite fiber is 45 to 85 weight ratio of the first polyester-based resin to the core portion; It consists of 0.1 to 5 weight ratio of UV absorber and 10 to 50 weight ratio of the second polyester-based resin,
The sheath part of the second component is composed of a low-melting polyester resin,
The first polyester-based resin is a polycondensate of aromatic dicarboxylic acid and glycol, one or two selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate. a mixture of the above,
The second polyester-based resin is an esterification reaction of diol and dicarbonic acid, which are hard segment raw materials, and polyol, a soft segment raw material, is polycondensed with the reaction product,
The diol is composed of 1,4-butanediol (1,4-BD) or a mixture of 1,4-butanediol (1,4-BD) and 2-methyl 1,3-propanediol (MPO),
The dicarbonic acid is either dimethyl terephthalate (DMT) or dimethyl isophthalate (DMI), or is composed of a mixture of an anhydride resin mixed with any one composition,
The polyol (Polyol) is composed of any one of poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) and polypropylene glycol (PPG),
The low-melting polyester resin is an acid component composed of terephthalic acid or an ester-forming derivative thereof, and a diol component composed of 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol, and ethylene glycol. formed,
The UV absorber is titanium dioxide (TiO2), characterized in that the soft heat-adhesive composite fiber for sanitary material non-woven fabric.
delete The method of claim 1,
2-methyl-1,3-pentanediol of the low-melting polyester resin is a soft for sanitary non-woven fabric comprising a low-melting polyester fiber, characterized in that it contains 0.01 to 5 mol% of the diol component. heat-bonded composite fiber.
The method of claim 1,
The composite fiber is a soft heat-adhesive composite fiber for sanitary material non-woven fabric, characterized in that the first component and the second component have a weight ratio of 80:20 to 20:80.

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