KR101651666B1 - High-softness polyolefin staple fiber and method for fabricating the same and thermal bonding non-woven using thereof - Google Patents

Abstract

The present invention relates to a method for producing a polyolefin-based staple fiber, comprising the steps of: melting a polymer copolymerized with 74 to 82% by weight of propylene, 12 to 18% by weight of ethylene and 6 to 8% by weight of butene; Spinning the melt at a spinning temperature of from 220 to 270 캜 at a rate of from 50 to 140 m / min; Stretching the spinning non-drawn yarn to a draw ratio of 1.5 to 4.0 and a preheating temperature of 50 to 80 캜; A crimping step of applying a crimp to the stretched filament; A surface treatment step of spraying a spinning oil on the crimped filaments to fix them; And a short fiber forming step of cutting the surface-treated filament by a predetermined length after thermally fixing the filament. The present invention also provides a method for producing a high-softness polyolefin-based staple fiber.

Nonwoven fabric, polyolefin, butene, ethylene

Description

TECHNICAL FIELD [0001] The present invention relates to a high-softness polyolefin staple fiber and a method for manufacturing the same, and a thermal bond non-woven fabric using the same,

The present invention relates to a copolymerized polyolefin short fiber and a polyolefin short fiber having a hypoallergenic, highly flexible and heat-sealable property as a copolymerized polymer, a method for producing the same, and a nonwoven fabric using the same.

Generally, polyolefin-based short fibers of polyethylene, polypropylene and copolymers thereof are widely used as materials for nonwoven fabrics due to their unique low melting point and excellent chemical resistance.

Such a nonwoven fabric is a fabric made by adhering or tangling a fiber aggregate by a machine or a chemical treatment such as a machine operation or a heat treatment without going through a process of weaving, weaving or knitting, and is used as felt, a nonwoven fabric bonded with resin, needle punch, spun bond, spun lace, Emboss film, and wet nonwoven fabric. In the discussion, it means that the contact between the web and the web overlapping randomly is bonded to the resin and used as a wick. It is also called bonded fabric and also called bonded fabric. Such nonwoven fabrics can be produced by various methods, such as needle punching, chemical bonding, thermal bonding, melt blowing, spun lacing, stitch bonding, and spunbond.

Nonwoven fabrics made of polyolefin-based staple fibers are used as sanitary articles such as napkins and diapers because of their soft feel and high strength. In particular, polypropylene staple fibers are processed into a thermal bond nonwoven fabric by a calender bonding method or an air through bonding method due to a unique low melting point and excellent chemical resistance, and are used for disposable diapers for infants, disposable diapers for adults, sanitary napkins for sanitary purposes, A cover material such as a nonwoven fabric, a water towel, a mask, a filter bag of a vacuum cleaner, and a table cover fabric. Therefore, in many cases, the skin is in contact with the skin, so that the skin is required to have flexibility that improves hypoallergenicness and texture.

The polypropylene thermosetting nonwoven fabric disclosed in Japanese Patent Laid-Open No. 2002-235237 seeks softness and high tensile strength through the use of three finenesses by introducing the salicylic acid metal salt into the masterbatch pellet as a crystallization inhibitor in order to impart soft touch and high tensile strength to the nonwoven fabric However, the test method for spunbonded nonwoven fabric differs from that of the thermal bond nonwoven fabric by using short fibers. The spunbond nonwoven fabric has a higher tensile strength than the single-fiber thermal bond nonwoven fabric, but soft tactile feeling usually falls. Further, according to the present invention, when the ethylene content of the spunbonded nonwoven fabric made from the propylene / ethylene random copolymer is 1.5% by weight or more, low crystallinity may be caused and the strength of the nonwoven fabric may be lowered.

Accordingly, there is a need to develop a high-softness staple fiber and a nonwoven fabric which are excellent in the feeling of use of sanitary articles such as infant diapers, surface materials for women's products, and wet tissues, which have skin irritation prevention and relieving effects such as inflammation due to soft touch .

In order to solve the above problems, it is an object of the present invention to provide a polyolefin short fiber having high softness and little skin irritation, a method for producing the same, and a thermal bond nonwoven fabric using the same.

The present invention also provides a high-soft polyolefin short fiber excellent in all properties of short fibers and nonwoven fabric while having high ductility and low polarity, and a method for producing the same and a thermal bond nonwoven fabric using the same.

In order to accomplish the above object, the present invention provides a method for producing a polyolefin-based staple fiber, comprising the steps of: melting a polymer copolymerized with 74 to 82% by weight of propylene, 12 to 18% by weight of ethylene and 6 to 8% Spinning the melt at a spinning temperature of from 220 to 270 캜 at a rate of from 50 to 140 m / min; Stretching the spinning non-drawn yarn to a draw ratio of 1.5 to 4.0 and a preheating temperature of 50 to 80 캜; A crimping step of applying a crimp to the stretched filament; A surface treatment step of spraying a spinning oil on the crimped filaments to fix them; And a short fiber forming step of cutting the surface-treated filament by a predetermined length after thermally fixing the filament. The present invention also provides a method for producing a high-softness polyolefin-based staple fiber.

The copolymerized polymer has a melt index (MI) of 10 to 30 g / 10 min, an isotactic index of 80 or more, and a melting point (DSC) of 135 to 150 ° C. .

The present invention also provides a method for producing a high-softness polyolefin-based staple fiber, wherein the melt further comprises one or more additives selected from the group consisting of an antioxidant, a UV stabilizer, a process stabilizer, and a colorant.

Also, the present invention provides a method for producing a high-softness polyolefin-based staple fiber, wherein the additive is contained in the melt in an amount of 0.1 to 3% by weight.

The present invention also provides a high-softness polyolefin-based staple fiber characterized in that it is made of a copolymer of 12 to 18% by weight of ethylene, 6 to 8% by weight of butene and 74 to 82% by weight of propylene in the polyolefin-based staple fiber.

Also, the copolymerized polymer is made of a homopolypropylene having a melt index (MI) of 10 to 30 g / 10 min, an isotacticity index of 95 or more, and a melting point (DSC) of 160 to 165 ° C. Provide staple fibers.

The present invention also provides a highly flexible polyolefin-based staple fiber produced by the above method.

The present invention also provides a high-softness polyolefin-based nonwoven fabric which is produced by the thermal bonding method using the functional polyolefin-based staple fibers produced by the above-mentioned method or the above-mentioned staple fibers.

In addition, the thermal bonding method is a calender bonding method or an air through bonding method, and provides a highly flexible polyolefin based nonwoven fabric.

The calender bonding method is characterized in that short fiber is carded at a speed of 80 to 150 mpm and then a nonwoven web is prepared and the web is passed through between hot rolls set at 140 to 165 ° C to produce hot- By weight based on the total weight of the polyolefin-based nonwoven fabric.

Hereinafter, preferred embodiments of 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 have the same reference numerals as much as possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms "substantially", "substantially", and the like are used herein to refer to a value in or near the numerical value when presenting manufacturing and material tolerances inherent in the meanings mentioned, Absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

As used herein, the term nonwoven fabric refers to a fabric collectively referred to as a fabric, a felt, and a fibrous web formed by bonding or tangling a fiber aggregate by a machine or chemical treatment such as a machine operation or a thermal bonding without going through a weaving, weaving or knitting process use.

1 shows a process for producing a polyolefin-based staple fiber according to a preferred embodiment of the present invention.

TECHNICAL FIELD The present invention relates to a polyolefin-based short fiber for a nonwoven fabric which is copolymerized with propylene, ethylene, and butene to have no skin irritation and has a high softness.

The polyolefin-based staple fiber according to a preferred embodiment of the present invention comprises a spinning step of spinning a melt to produce an undrawn yarn through a melting step of polymerizing propylene, ethylene, and butene, as shown in FIG. 1, And then passes the crimped step of stretching the spinning non-drawn yarn and crimping the drawn filament. Forming a short fiber by forming a short fiber by cutting a predetermined length through a surface treatment step of spraying a spinning agent on the crimped filament and fixing and fixing the filament by heat.

The raw material of the fibers according to the present invention is prepared by copolymerizing propylene, ethylene and butene randomly copolymerized with 74 to 82% by weight of propylene, 12 to 18% by weight of ethylene and 6 to 8% by weight of butene.

If the mixing ratio is exceeded, the radioactivity may be lowered or the flexibility may be deteriorated after manufacturing the short fibers.

The copolymerized polymer preferably has a melt index (MI) of 10 to 30 g / 10 min, an isotacticity index of 80 or more, and a melting point (DSC) of 135 to 150 ° C.

The polypropylene staple fiber made of the copolymerized polymer has a specific low melting point and excellent chemical resistance and is suitable as a surface material for sanitary articles such as diapers and sanitary napkins due to its low ductility.

When the copolymerized polymer is produced as a short fiber, the copolymerized polymer is melted and then radiated at a spinning temperature of about 220 to 270 DEG C at a spinning speed of about 50 to 140 m / min to properly adjust the spinning ratio between 1.5 and 4.0, After stretching at a temperature of 50 to 80 캜, crimp is given, and a radial emulsion is sprayed to adhere the radial emulsion to the fiber surface.

The melt obtained by melting the copolymerized polymer may further include at least one additive selected from the group consisting of antioxidants, ultraviolet stabilizers, process stabilizers and colorants including white pigments, If it is more than 3.0% by weight based on the weight of the short fibers, the physical properties of the short fibers are impaired. Therefore, it is preferably contained in an amount of 3.0% by weight or less. If the amount is less than 0.1% by weight, the effect of additives can not be expected. Lt; / RTI > Accordingly, it is preferable that the additive is contained in the short fiber in an amount of 0.1 to 3.0% by weight of the polyolefin-based short-staple fiber.

After that, the fiber is opened and fixed at a temperature of about 100 to 120 ° C for about 8 to 12 minutes, and then the fiber is cut to a length of about 30 to 50 mm to obtain a polyolefin having a final fiber fineness of 2.0 to 4.0 denier and an average elongation of 300 to 400% Fibers can be produced.

The above-mentioned radial emulsions may be used as lubricants for smoothing the fiber production process, and may be machine oil, liquid paraffin, white oil, etc. as mineral oil and synthetic oil lubricant.

Alternatively, heat-resistant spinning emulsions can be used to enhance the heat resistance of the polyolefin staple fibers. The heat-resistant spinning emulsion may be a double-quaternary polydimethylsiloxane-based hydrophilic lubricant, and it may further preferably include an antistatic agent.

When the double quaternary polydimethylsiloxane-based hydrophilic lubricant and the antistatic agent are used, 95 to 99% by weight of the second quaternary polydimethylsiloxane-based hydrophilic lubricant and 1 to 5% by weight of the antistatic agent are mixed and used as a heat-resistant oil repellent .

Alternatively, a functional radial emulsion obtained by mixing the above-mentioned radial emulsion and phytoncide may be used to enhance the antibacterial properties of the polyolefin staple fiber.

The phytoncide is an aromatic substance which is sprayed to protect itself from various insects and bacteria, and contains a sterilizing and insecticide component itself. The main component of phytoncide is terpene-based organic compounds. These terpenes are known to have antimicrobial, sedative, deodorizing and stress relieving functions.

In addition, phytoncide, a natural substance, is known to be most effective at preventing house dust mite allergy by virtue of avoiding house dust mite up to 90%.

The mixing ratio of the radial emulsion and the phytoncide may be preferably 50 to 99% by weight of the spinning oil and 1 to 50% by weight of the phytonchid.

The radial emulsion described above may preferably be applied to the short fibers in an amount of 0.1 to 10% by weight of the polyolefin-based staple fibers.

When the staple fiber is produced by the method according to the preferred embodiment of the present invention, the thermal bond processing for producing the nonwoven fabric may be performed. The thermal bonding method can be accomplished using a calender bonding method and an air through bonding method. The calender bonding method is a method in which a short fiber is carded at a speed of 80 to 150 mpm, and then a nonwoven web is prepared, and the web is passed between hot rolls set at about 140 to 165 DEG C, . At this time, the basis weight of the nonwoven fabric is preferably 20 to 40 gsm.

On the other hand, when foreign substances are adhered to the surface of the fibers, bubbles are generated during fixing, which causes a deterioration of the physical properties of the nonwoven fabric. In this case, since the emulsion or the like may act as a foreign material, proper content is important.

In the present invention, in manufacturing a thermal bond nonwoven fabric through the calendering bonding facility, the temperature of the hot roll with the best hot fixation depends on the production speed of the nonwoven fabric, the emboss pattern of the roll, the difference between the setting temperature and the surface temperature of the roll And it is a relative result rather than an absolute result because it can be changed according to the production equipment condition of the calendering bonding method of the present invention and the fineness of the short fiber used as the raw material.

The high-soft polyolefin staple fiber according to the present invention is produced by copolymerizing propylene, ethylene and butene, and is superior in physical properties to conventional polyolefin staple fibers and nonwoven fabric.

In addition, the high-soft polyolefin nonwoven fabric of the present invention, unlike the thermal bond nonwoven fabric composed of short fibers made only of homopolypropylene which is widely used as a hygiene material, has a very soft characteristic that conventional polyolefin short fibers do not have, Prevention and mitigation effects.

Accordingly, the highly flexible polyolefin short fibers and nonwoven fabric of the present invention are suitable for sanitary articles such as diapers, sanitary articles, and wet tissues, and have a skin irritation prevention and alleviating effect, so that they can be applied as sanitary articles having superior functionality.

1. Preparation of polyolefin staple fibers

Example 1

82% by weight of propylene, 12% by weight of ethylene and 6% by weight of butene were mixed to prepare an unstretched fiber at a spinning temperature of 230 DEG C and a spinning speed of 50 to 100 m / min.

The stretching ratio of the undrawn yarn was adjusted to between 1.5 and 4.0, the yarn was stretched at a preheating temperature of 70 DEG C to crimp the yarn in the crimper, and the yarn emulsion was sprayed so that the content of the yarn emulsion was 0.6 wt% And then thermally fixed at a temperature of 100 to 110 ° C for about 10 minutes and then cut to a length of 40 mm so that the final fiber fineness is 1.5 to 3.0 denier and the average elongation is 300 to 380% Staple fibers.

Example 2

The procedure of Example 1 was followed except that the copolymerized polymer was mixed with 80 wt% of propylene, 13 wt% of ethylene and 7 wt% of butene to prepare polyolefin staple fibers.

Example 3

The procedure of Example 1 was repeated except that the copolymerized polymer was mixed with 74 wt% of propylene, 18 wt% of ethylene and 8 wt% of butene to prepare polyolefin staple fibers.

Comparative Example 1

The procedure of Example 1 was repeated except that homopolypropylene was used instead of the copolymerized polymer to prepare polyolefin staple fibers.

2. Production of polyolefin thermal bonding nonwoven fabric

Each of the polyolefin short fibers obtained by the above method was carded at a speed of 115 mpm to prepare a nonwoven web and passed between two hot rolls to prepare a calender-bonded nonwoven fabric having a basis weight of 22 g / m 2.

At this time, while setting the temperature of the hot roll at 130 to 150 ° C., the optimum temperature which has the highest tensile strength of the nonwoven fabric was determined as the open hardening temperature (hereinafter referred to as optimum hot rolling temperature).

* Analysis method

1. Melt Index (MI): according to ASTM D 1238

Homopolypropylene and random copolymer series: 230 占 폚, load of 2.16 kg

* HDPE, LDPE etc. PE series: 190 ℃, load of 2.16kg

2. Isotactic Index (ISO): ISO 9113: 1986 ... Plastics - Polypropylene (PP) and propylene-copolymer thermoplastics Determination of isotactic index: After boiling n-heptane to dissolve the atactic component, the remaining isotactic component is weighed and expressed as wt%, and this is expressed as isotactic index .

3. Xylene Soluble (hereinafter referred to as XS): ISO 16152: 2005

4. Radioactive: Evaluate the frequency of the drop of fiber and the number of drop of fiber at the bottom of the cage with 37,125 holes.

Single thread or drop less than once / hour: ◎

Single thread or drop 1 to 3 times / hour: ○

Single thread or drop 3 times / hour or more: △

No radiation: ×

5. Extensibility: Evaluate the number of times of refusal in the process of softening work

1 time / less than: ○, 1 to 2 times / hour: Δ, 3 times / hour or more: ×

6. Crimping workability: Failed number of times when the tow drawn by the naked eye passes through the crimper

1 time / less than: ○, 1 to 2 times / hour: Δ, 3 times / hour or more: ×

7. Monofilament fineness: Determination of fineness based on ASTM D1577

8. Non-woven carding property: It is judged to be bad when a short fiber is passing through a card machine and a curling phenomenon or a flying phenomenon occurs between card rolls or a web formation is not good

9. Basis weight: Weight of nonwoven fabric (g / ㎡)

10. Tensile strength and elongation of nonwoven fabric: cut-strip method (sample width 5 cm, length 14 cm) of JIS L 1096,

MD: machine direction of nonwoven fabric / CD: transverse direction of nonwoven fabric

11. TBI (Thermal Bondability Index) = {(MD intensity x CD intensity)} x (20 / basis weight)

division weight Strength (kg / 5 cm) Shinto (%) (g / m 2) MD CD MD CD Example 1 22.0 4.75 1.31 52 96 Example 2 22.0 4.73 1.35 56 94 Example 3 22.0 4.76 1.34 53 97 Comparative Example 22.0 4.10 0.95 38 63

Table 1 shows the physical properties of the nonwoven fabric prepared from the above Examples and Comparative Examples. The nonwoven fabric made of the high-softness polyolefin-based staple fibers according to the present invention has higher strength and elongation than the nonwoven fabric made of homo polypropylene .

◎ Evaluation method of skin irritation

To evaluate the skin irritation of nonwoven fabric, a patch test was performed on 25 healthy adults (male and female)

In order to examine the degree of skin irritation of the thermally bonded nonwoven fabrics of the polyolefin staple fibers prepared in the above-described Examples and Comparative Examples, they were compared with cosmetics generally used for skin protection. After the nonwoven fabric was adhered to the skin of the subject for 24 hours, the skin condition change after 2 hours after the removal of the nonwoven fabric and the cosmetic sample were added to the pin chamber with a certain amount (about 0.2 g) For 24 hours, and then the pin chamber was removed and the skin condition change after 2 hours was judged by two experts. The stimulus and stimulus responses were evaluated according to the criteria shown in Table 2. The results are shown in Table 3 Respectively.

Irritation degree Stimulus response Criteria 0 - No symptoms One + - When there is only a slight erythema reaction 2 + If there is clear erythema edema but no blisters 3 ++ If you have a clear erythema, edema, blisters 4 +++ When there is a logarithm

division Judgment result (number of people) Skin irritation index ++ + + - - Example 1 0 0 0 25 0.00 Example 2 0 0 One 23 0.04 Example 3 0 0 One 24 0.04 Comparative Example 0 0 3 23 0.13 Cosmetic A 0 0 3 24 0.13 Cosmetics B 0 0 2 23 0.09 Cosmetics A is a men's skin lotion, and cosmetics B is a women's skin lotion.
Skin irritation index = irritation degree x number of subjects showing the reaction / total number of subjects

As shown in Table 3, the comparative example was evaluated with the stimulation index of stimulation such as cosmetic A, and the skin irritation index of Example 1 was 0.00, which is the lowest value among the other examples and the comparative example, cosmetics A and B have. It can be seen from Table 3 that the skin irritation index of Examples 2 and 3 is lower than that of Comparative Example, cosmetics A and B, and that the nonwoven fabric made of the highly flexible polyolefin short fibers of the present invention has little skin irritation .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of a process for producing a polyolefin-based staple fiber according to a preferred embodiment of the present invention.

Claims (10)

A method for producing a polyolefin-based staple fiber, Melting a polymer copolymerized with 74 to 82% by weight of propylene, 12 to 18% by weight of ethylene and 6 to 8% by weight of butene; Spinning the melt at a spinning temperature of from 220 to 270 캜 at a rate of from 50 to 140 m / min; Stretching the spinning non-drawn yarn to a draw ratio of 1.5 to 4.0 and a preheating temperature of 50 to 80 캜; A crimping step of applying a crimp to the stretched filament; A surface treatment step of spraying a spinning oil on the crimped filaments to fix them; And And a step of forming a short fiber by cutting the surface-treated filament by a predetermined length after heat-setting, Wherein the copolymerized polymer has a melt index (MI) of 10 to 30 g / 10 min. delete delete delete In the polyolefin-based staple fiber, From 12 to 18% by weight of ethylene, from 6 to 8% by weight of butene and from 74 to 82% by weight of propylene, Wherein the copolymerized polymer has a melt index (MI) of 10 to 30 g / 10 min. delete delete delete delete delete

Images