KR20190124953A - Hygienic Non-woven Soft Thermal Bonding Compound Fiber - Google Patents

Abstract

The present invention relates to a soft thermal bonding composite fabric for a hygienic nonwoven fabric. More specifically, the soft thermal bonding composite fabric includes a core portion consisting of a polyester-based composition, and thus exhibits an improved softness when used as a nonwoven fabric. The soft thermal bonding composite fabric comprises a polyester-based resin as a first component and a polyolefin-based resin whose melting point is at least 20°C lower than that of the polyester-based resin, as a second component, wherein the polyester-based resin includes 30-95 wt% of a first polyester-based resin and 5-70 wt% of a second polyester-based resin mixed therein.

Description

Hygienic Non-woven Soft Thermal Bonding Compound Fiber

The present invention relates to a soft heat-bonded composite fiber for sanitary nonwoven fabrics to a soft heat-bonded composite fiber for sanitary nonwoven fabrics formed to improve the softness of the nonwoven fabric by applying a flexible polyester-based fiber. It is about.

Low-density nonwovens with a fabric density of 10-45 g / m 2 are used as surface materials for paper diapers and sanitary napkins. As the use of nonwoven fabrics is diversified, the characteristics required for nonwoven fabrics also become strict, and there has been a demand for nonwoven fabrics having high strength while maintaining a soft touch.

In order to meet these demands, there is a need for a composite fiber that is fine and heat-adhesive, and that a low melting point component not only provides sufficient heat adhesion strength but also gives flexibility.

Sheath-core or side-by-side composite fibers having a low melting point component of a conventional polyolefin-based component such as polyethylene and polypropylene, and a high melting point component of a polyester such as polyethylene terephthalate and a polyolefin-based component such as polypropylene Is known a lot.

For example, US Pat. No. 5,866,488 discloses that the first component is polyethylene and the second component is polyester, the polyethylene continuously occupying at least a portion of the fiber surface in the longitudinal direction and having a molecular chain of 1.5 / 1000 carbon atoms. A heat-sealable composite fiber having a methyl branch of less than or equal to 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 presented.

U.S. Patent No. 5,798,305 also includes a high melting point component of polypropylene or polypropylene and a low melting point component of polyethylene, wherein polyethylene forms at least a portion of the fiber surface continuously in the fiber direction and is from 0 to 1.5 methyl in the molecular chain. 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 presented.

Therefore, the pulled (FD) heat-adhesive fiber added with TiO ₂ is used for soft sensitivity of the sanitary nonwoven fabric as described above. to be.

As described above, the release cross-section heat-bonded composite fiber for sanitary nonwoven fabric according to the present invention is composed of a flexible polyester-based composition in the core portion and is formed in a circular or release cross-section to decrease the bending stiffness of the composite fiber, thereby improving softness when used as a nonwoven fabric. It is effective.

In addition, there is an effect of providing a heat-adhesive composite fiber for a nonwoven fabric binder excellent in softness and good processability.

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

In another aspect, the present invention is the composite fiber is one circular or two to four circles are attached in a line, the core provides a soft thermal adhesive composite fiber for sanitary nonwoven fabric, characterized in that the square or round.

In another aspect, the present invention is the composite fiber provides a soft heat-bonded composite fiber for sanitary nonwoven fabrics, characterized in that the first component and the second component has a weight ratio of 80:20 ~ 20:80.

As described above, the soft heat-bonded composite fiber for sanitary nonwoven fabric according to the present invention has an effect of lowering bending rigidity and improving softness when used as a nonwoven fabric.

In addition, there is an effect of providing a heat-adhesive composite fiber for a nonwoven fabric binder excellent in softness and good processability.

1 is a cross-sectional view showing a composite fiber of the present invention.
2 to 4 is a cross-sectional view showing a composite fiber of various cross-sectional cross-sectional shape according to the invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First, in describing the present invention, a detailed description of related known functions or configurations will be omitted so as not to obscure the subject matter of the present invention.

As used herein, the terms 'about', 'substantially', and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the stated meanings are set forth, and an understanding of the present invention may occur. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in the drawings, the same components or parts denote the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

As used herein, the terms "about", "substantially", and the like, are used at, or in close proximity to, numerical values as are indicative of preparation and material tolerances inherent in the meanings mentioned, and are intended to be accurate or to facilitate understanding of the invention. Absolute figures are used to prevent unfair use by unscrupulous infringers.

'Releasing ratio' disclosed in the present invention is a value defined by the following formula of the fiber cross section, when viewed in the horizontal axis of the long axis as shown in Figures 2 to 4, the short axis (A) is the longest length of the longitudinal axis of the fiber cross section The long axis means the longest length of the horizontal axis of the fiber section.

◈ Release ratio = Long axis (B) / Short axis (A)

1 to 4 is a cross-sectional view showing a composite fiber of various cross-sectional forms according to the present invention.

The composite fiber of the present invention is formed of a cis-core type with a polyolefin-based resin having a melting point of 20 ° C. or more lower than that of the polyester-based resin as a first component and a polyester-based resin as a second component.

The first component polyester resin is a mixture of 30 to 95% by weight of the first polyester resin and 5 to 70% by weight of the second polyester resin.

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

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

Preferably, polyethylene terephthalate may be used, and the polyester-based resin may preferably use an intrinsic viscosity (IV) of 0.50 to 0.80 dL / g according to ASTM 02857.

The second polyester-based resin esterifies a diol (Diol) and dicarbonic acid (hard segment raw material) and polycondenses the polyol (Polyol) as a soft segment raw material to the reactant,

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

The dicarbonic acid may be any one of dimethyl terephthalate (DMT) and dimethyl isophthalate (DMI), or may be composed of a mixture of anhydride resin and any one of the above compositions.

The polyol 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 and dimethyl terephthalate (DMT) is expensive but exhibits the same effect.

The anhydride resin is also methyl tetrahydrophthalic anhydride (MeTHPA), methyl hexahydrophthalic anhydride (MeHHPA), terahydrophthalic anhydride (THPA) and hexahydrophthalic anhydride May be composed of a mixture to which at least one of hydrides (HHPA) is added,

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

In addition, an anhydride resin of the dicarbonic acid may be used directly as a starting material of an esterification reaction, but a conjugated diene and a maleic hydride having two double bonds may be used. Products via the Diels-Alder reaction of maleic anhydride can also be used.

When the esterification reaction is first described for the method for preparing the polyester-based elastic adhesive resin composition, the low molecular weight diol component and dimethyl terephthalate of butylene glycol of 1,4-butanediol (1,4-BD) to form hard segments And esterification with (DMT).

The reaction capacity is a mole fraction of dicarbonic acid and diol in a ratio of 1 to 1.0 to 1.5, and the excess diol component is recovered through decompression during condensation polymerization. (Dicarbonic acid) and diol (Diol) has a value of 30 to 90% by weight of the total second polyester resin.

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

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

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

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

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

Substantially, a small amount of methyl tetrahydrophthalic anhydride (MeTHPA) is added to cause a melting point drop, and a drop of about 4 ° C per mole can be obtained, and methyl tetrahydrophthalic anhydride (MeTHPA), methyl When hexahydrophthalic anhydride (MeHHPA) is used in a molar ratio of 4-6 to 6-4, the melting point decreases more.

 For example, compared to the case of using only anhydride (MeTHPA) alone, when used in combination, the effect of a drop of about 5 ℃ per mol of the mixture shows a greater melting point lower effect.

The catalyst used in the esterification reaction is selected from the group consisting of zinc acetate, sodium acetate, magnesium acetate, tetranomalbutoxytitanate, tetraisopropyl titanate, titanium oxide / silicon oxide micropolymer, and nano titanate It is used in the range of 50 to 1000 ppm with respect to 100 parts by weight of polyester-based elastomeric adhesive resin, and when the input amount of the catalyst is insufficient, the reaction rate of esterification is slowed down, and if it is excessive, the thermal stability of the polyester-based elastic adhesive resin is exceeded. Worse

After the esterification reaction, condensation polymerization is carried out.

The oligomer solution obtained by the above esterification reaction and a soft segment of polyol (Polyol) were introduced into a pressure resistant, vacuum resistant, heat resistant reactor with a polycondensation catalyst, a thermal stabilizer and a photooxidation stabilizer, and then a pressure of 760 to 1000 Torr and 200 After distilling an excess of diol at a temperature of ˜270 ° C., condensation polymerization is completed under high vacuum having a final vacuum of 1 mmHg or less to obtain a second polyester resin.

The polyol may be selected from poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) or polypropylene glycol (PPG), the molecular weight of the polyol is 400 to 20000, the polyether ester It contains 10 to 80% by weight based on the resin.

In addition, the polymerization catalyst used in the condensation polymerization step is one selected from the group consisting of antimony trioxide, antimony acetate, tetranormal butoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide micropolymer, and nano titanate. As mentioned above, it can be used in 50-2000 ppm range with respect to 100 weight part of polyester-type elastic adhesive resins.

The polyolefin resin having a melting point of 20 ° C. or more lower than the first component resin may include at least one selected from high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), polypropylene, and ethylene-propylene copolymer. Mixtures may be used.

Preferably, high density polyethylene (HDPE) may be used, and the flow flow index (MI, Melting lndex) of the olefin resin is not particularly limited, but the flow flow index is 1 to 100 g / lO minutes, more preferably 5 to It would be desirable to be 40 g / 10 minutes.

In the composite fiber of the present invention, the first component and the second component form a composite fiber in a sheath-core structure, and the first component may form a sheath or core, and the second component may form a core or sheath. It is preferable that the resin having the higher melting point among the first component and the second component used as being constitutes the sheath with the resin having the lower melting point.

In addition, it is preferable that the composite fiber has a first component and a second component in a weight ratio of 80:20 to 20:80.

The shape of the cross section of the composite fiber is not limited, but in order to lower the bending stiffness of the fiber, it is reasonable that the release ratio is 1.5 or more. The release ratio is less than 1.5, and the softness of the nonwoven fabric produced may be reduced.

The heteromorphic cross section of the composite fiber is oval as shown in FIG. 2 (a), or is rectangular as shown in FIG. 2 (b) or a cross section in which 2 to 4 circles are lined up as shown in FIGS. 3 and 4. Preferably, when formed in the above-described release cross-section will be able to meet the conditions of the release ratio.

The release cross-section heat-bonded composite fiber of the present invention may have the same sheath cross-section and core cross-section as shown in FIGS. 2, 3 (a) and 4, but according to the nonwoven fabric used, The core cross section may be formed in other shapes.

In general, the sheath of the heat-bonded composite fiber is often heat-bonded when the nonwoven fabric is manufactured so that the original shape is not maintained, but the core is not melted by heat treatment and the initial shape is maintained. Most preferably, the core cross section is formed into a rectangle having a release ratio of 1.5 or more.

Hereinafter, an embodiment of a method for producing a release cross-section thermal adhesive composite fiber for a sanitary nonwoven fabric according to the present invention is shown, but the present invention is not limited to the embodiment.

Example  1 to 4

60% by weight of 5-50% by weight of the second polyester resin as the first component composition As the composition and the second component, 40 wt% of the high density polyethylene having a flow flow index of 20 g / 10 min was added to a separate extruder and melted.

The molten first component and the second component composition were introduced into a conventional cis-core hetero-section composite spinning device and spun at a spinning speed of 800 m / min. The composite fiber spun at 3.5 times or more at a temperature above the glass transition temperature of polyethylene terephthalate was stretched, crimped and cut to 38 mm to prepare a release cross-section heat-bonded composite fiber according to the present invention. Cross section and release ratio of the composite fiber is shown in Table 1.

Comparative Example 1

Prepared in the same manner as in Example 1, but contained 0 wt% of the flexible polyester-based component in the first component.

Comparative Example 2

Prepared in the same manner as in Example 1, but contained 80 wt% of the flexible polyester-based component in the first component.

Comparative Example 3

Prepared in the same manner as in Example 1, but contained 100 wt% of the flexible polyester-based component in the first component.

◈ Property evaluation of Examples and Comparative Examples

1. Property evaluation method

* Release ratio = Long axis (B) / Short axis (A)

* Softness

The non-woven fabric was manufactured in 20GSM standard using the manufactured fiber, and the score was converted into 10 people's sensitivity evaluation.

The softness of one example specimen and one comparative example specimen having the same material composition and the same fineness was emotionally evaluated and converted into a score by a selected person out of ten evaluators.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 1 ingredient PET PET PET PET PET PET Second polyester resin content (wt%) in one component 5 20 50 0 80 100 2-component HDPE HDPE HDPE HDPE HDPE HDPE section 1   3 (a)   Figure 2 (a)  1 1 1 Release ratio One 2.5 1.5 One One One Non-woven
contractility(%) 0 10 20 0 0 80 Softness 80 points 80 points 80 points 85 points 20 points 20 points

As shown in Table 1, Examples 1 to 3 according to the present invention had higher softness compared to Comparative Examples 1 to 3, and nonwoven fabric shrinkage was also 20% or less.

In particular, although Comparative Examples 2 to 3 contained a flexible polyester component, excessive shrinkage occurred due to excessive content, and thus softness was lowered.

Features and other advantages of the present disclosure as described above will become more apparent from the following examples, which are described for illustrative purposes only and should not be construed as limiting or limiting the scope of the invention. .

Claims (3)

In soft thermal adhesive composite fiber for sanitary nonwovens,
The composite fiber is formed of a cis-core type of a polyolefin resin having a melting point of 20 ° C. or more lower than that of the polyester resin as a first component and a polyester resin as a second component.
The polyester resin is a mixture of 30 to 95% by weight of the first polyester resin and 5 to 70% by weight of the second polyester resin,
The first polyester resin is one or two selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate as a condensation product of aromatic dicarboxylic acid and glycol. Is a mixture of the above,
The second polyester-based resin is esterified by diol (Diol), which is a hard segment material, and dicarbonic acid, and polycondensation of polyol, which is a soft segment material, to the reactant.
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 dicarboxylic acid (Dicarbonic acid) is any one of dimethyl terephthalate (DMT) or dimethyl isophthalate (DMI), or is composed of a mixture of an hydride (anhydride) resin in any one composition,
The polyol (Polyol) is a soft thermal adhesive composite fiber for the sanitary nonwoven fabric, characterized in that composed of any one of poly (tetramethylene ether) glycol (PTMG), polyethylene glycol (PEG) and polypropylene glycol (PPG).
The method of claim 1,
The composite fiber is one circular or two to four circles are attached in a row, the core is a soft heat-bonded composite fiber for sanitary nonwoven fabrics, characterized in that the square or round.
The method of claim 1,
The composite fiber is a soft heat-bonded composite fiber for sanitary nonwoven fabrics, characterized in that the first component and the second component has a weight ratio of 80:20 ~ 20:80.

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