WO2021006527A1 - Non-woven fabric of crimped composite fiber and laminate thereof, and article - Google Patents

Abstract

Disclosed are non-woven fabric of crimped composite fiber and a laminate thereof, and an article. The disclosed non-woven fabric of crimped composite fiber is non-woven fabric of crimped composite fiber comprising a first propylene-based polymer and a second propylene-based polymer, wherein, in the first propylene-based polymer and the second propylene-based polymer, the melting point of the second propylene-based polymer is higher than the melting point of the first propylene-based polymer by 30 °C or more as measured using a differential scanning calorimeter (DSC), a ratio (the second propylene-based polymer/the first propylene-based polymer) of melt flow rates (MFR: measurement temperature of 230 °C, load of 2.16 kg) of the first propylene-based polymer and the second propylene-based polymer is 1.7 or more as measured in accordance with ASTM D1238, a ratio (the second propylene-based polymer/the first propylene-based polymer) of molecular weight distributions (MWD) of the first propylene-based polymer and the second propylene-based polymer is 1.5 or more as measured by gel permeation chromatography (GPC), and a component ratio represented by the first propylene-based polymer/the second propylene-based polymer (weight ratio) is 50/50-10/90.

Description

Nonwoven fabric of crimped composite fibers, laminates thereof, and articles

Disclosed are a nonwoven fabric of crimped composite fibers, a laminate thereof, and an article. In more detail, a nonwoven fabric of crimped conjugated fibers having improved softness and bulky properties, a laminate thereof, and an article are disclosed.

The final physical properties of the nonwoven fabric are determined according to the web forming method and the bonding method.

In the manufacture of the existing spunbond nonwoven fabric, the web is formed through single spinning or core-sheath composite spinning. The web thus formed has a simple structure without crimping, and is bonded by a heating calender to form a thin nonwoven fabric.

The thin non-woven fabric is used for top sheet and back sheet during diaper manufacturing, but the bulkiness is significantly lower than the short-fiber air-through non-woven fabric formed by carding and bonded with hot air. There is this.

In addition, due to the lack of crimp when forming the web, it has a large area that directly touches the baby's buttocks skin during diaper manufacturing, and there is no free space between the ADL layer (Aquisition Distribution Layer) when laminating nonwoven fabrics, so some urine during urination. There is a problem that remains on the top sheet, sores the baby's ass or causes a rash. In addition, there is a problem that urine leaks to the outside of the diaper.

One embodiment of the present invention provides a nonwoven fabric of crimped composite fibers with improved softness and bulky properties.

Another embodiment of the present invention provides a non-woven fabric laminate comprising two or more non-woven fabrics of the crimped composite fibers.

Another embodiment of the present invention provides an article including the nonwoven fabric laminate.

One aspect of the present invention,

As a nonwoven fabric of crimped composite fibers comprising a first propylene polymer and a second propylene polymer,

The first propylene-based polymer and the second propylene-based polymer have a melting point of the second propylene-based polymer measured by a differential scanning calorimeter (DSC) higher than the melting point of the first propylene-based polymer by 30°C or more, and the first propylene-based polymer The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the polymer and the second propylene polymer measured according to ASTM D1238 (the second propylene polymer/the first propylene polymer) is 1.7 or more And the ratio of the molecular weight distribution (MWD) measured by gel permeation chromatography (GPC) of the first propylene-based polymer and the second propylene-based polymer (the second propylene-based polymer/the first propylene-based polymer) is 1.5 The above, and the component ratio represented by the first propylene-based polymer/the second propylene-based polymer (weight ratio) is 50/50 to 10/90 provides a crimped composite fiber nonwoven fabric.

The first propylene-based polymer further includes 1 to 5% by weight of a nucleating agent in addition to the propylene-based polymer component as a main component, and the crystallization temperature of the first propylene-based polymer is 19°C or higher than the crystallization temperature of the second propylene-based polymer. I can.

The first propylene-based polymer includes a propylene homopolymer, and the second propylene-based polymer includes 70 to 90 parts by weight of a propylene homopolymer and 10 to 30 parts by weight of a propylene-ethylene-butylene terpolymer, and the propylene-ethylene -Butylene terpolymer may include 90 to 95% by weight of propylene, 2.5 to 5.0% by weight of ethylene, and 1.5 to 5.0% by weight of butene.

The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the first propylene-based polymer and the second propylene-based polymer measured according to ASTM D1238 (the second propylene-based polymer/the first propylene-based polymer ) May be 1.7 or more, and the number of crimps may be 29ea/10mm or less.

Each of the first propylene-based polymer and the second propylene-based polymer independently of each other further includes 1 to 5% by weight of a softener in addition to the propylene-based polymer component as a main component, and the Silksoft coefficient of friction may be 0.45 or less.

The crimped composite fiber may be a mono-type, a core sheath-type, a side-by-side type, or a sandwich-type composite fiber.

The crimped composite fiber nonwoven may include an embossing portion and a non-embossing portion, and the embossing portion may include a plurality of unit embossing pattern portions continuously arranged at the same or different intervals in an open embossing type.

Each embossing pattern included in the unit embossing pattern portion may have an area of 0.2 to 0.7 mm ² .

The crimped composite fiber nonwoven fabric may have a bonding rate of 13% or less.

The crimped composite fiber nonwoven fabric may be a spunbond nonwoven fabric.

Another aspect of the invention,

A nonwoven fabric laminate having at least two or more layers, of which at least one layer is a nonwoven fabric of the crimped composite fiber is provided.

The nonwoven fabric of the crimped composite fiber may be a spunbond nonwoven fabric, and the nonwoven fabric laminate may be configured such that the spunbond nonwoven fabric is exposed only on one side of both surface layers.

Another aspect of the invention,

It provides an article comprising the non-woven fabric laminate.

The article may be a diaper, absorbent article, toilet article, support layer or top sheet.

When the article is a diaper, the nonwoven fabric laminate may have a hydrophilic agent impregnation amount (OPU) of 0.7% or less so that the water absorption rate when applied to the top sheet layer of the diaper may be 3 sec or less.

The nonwoven fabric of the crimped composite fiber according to an embodiment of the present invention has a clear shape of a crimp and good shape safety, and excellent softness and bulkiness can be improved.

Accordingly, the diaper including the nonwoven fabric of the crimped composite fiber may not hurt the wearer's skin or cause a rash.

1 is a partial view showing an embossing pattern of a nonwoven fabric of a crimped composite fiber according to an embodiment of the present invention.

2 is a partial view showing an embossing pattern of a nonwoven fabric made of a crimped composite fiber according to another embodiment of the present invention.

3 is a cross-sectional view of a crimped composite fiber used in Examples and Comparative Examples.

4 is a partial view showing the embossing pattern of the nonwoven fabric of the crimped composite fiber prepared in Example 4.

Hereinafter, a nonwoven fabric of a crimped composite fiber according to an embodiment of the present invention will be described in detail.

The nonwoven fabric of the crimped composite fiber (hereinafter, simply referred to as "composite fiber") according to an embodiment of the present invention includes a first propylene polymer and a second propylene polymer.

The first propylene-based polymer and the second propylene-based polymer (i) the melting point of the second propylene-based polymer measured by a differential scanning calorimeter (DSC) is higher than the melting point of the first propylene-based polymer by 30°C or more, ( ii) The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the first propylene-based polymer and the second propylene-based polymer measured according to ASTM D1238 (the second propylene-based polymer/the first propylene Polymer) is 1.7 or more, and (iii) the ratio of the molecular weight distribution (MWD) of the first propylene polymer and the second propylene polymer measured by gel permeation chromatography (GPC) (the second propylene polymer/ The first propylene-based polymer) is 1.5 or more, and (iv) the component ratio expressed as the first propylene-based polymer/the second propylene-based polymer (weight ratio) is 50/50 to 10/90.

The molecular weight distribution (MWD) means the ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC).

For example, the melting point of the first propylene-based polymer may be 30°C to 60°C or 30°C to 100°C higher than the melting point of the second propylene-based polymer.

For example, the ratio of the melt index (the second propylene-based polymer/the first propylene-based polymer) may be 1.7-2.0, 1.7-3.0, or 1.7-4.0.

When the first propylene-based polymer and the second propylene-based polymer satisfy all of the above conditions (i) to (iv), the composite fiber has crimping properties, and the nonwoven fabric composed of the composite fiber has excellent softness and bulky properties. Can have

The first propylene-based polymer and the second propylene-based polymer are arranged to substantially occupy respective regions within the cross-section of the composite fiber, are continuously elongated along a length direction, and the first propylene-based polymer and the second propylene-based polymer 2 At least one component of the propylene-based polymer may continuously form at least a part of the surface of the peripheral portion along the length direction of the composite fiber.

In that it is possible to obtain a nonwoven fabric of composite fibers having excellent softness and bulky properties, the first propylene-based polymer contains a propylene homopolymer, and the second propylene-based polymer is 70 to 90 parts by weight of a propylene homopolymer and propylene -Including 10 to 30 parts by weight of ethylene-butylene terpolymer, the propylene-ethylene-butylene terpolymer may include 90 to 95% by weight of propylene, 2.5 to 5.0% by weight of ethylene, and 1.5 to 5.0% by weight of butene .

The first propylene-based polymer further includes 1 to 5% by weight of a nucleating agent in addition to the propylene-based polymer component as a main component, and accordingly, the crystallization temperature of the first propylene-based polymer is determined by the crystallization of the second propylene-based polymer. It can be 19℃ or more higher than the temperature.

The melting point of the first propylene-based polymer may be in the range of 120 to 175°C, and the melting point of the second propylene-based polymer may be in the range of 110 to 155°C. In addition, the difference in melting point of the two components may be in the range of 30°C or higher, 30°C to 60°C, or 30°C to 100°C as described above.

The nonwoven fabric may include 70 to 90 parts by weight of fibers formed by spinning of the first propylene-based polymer and 10 to 30 parts by weight of fibers formed by spinning of the first propylene-based polymer.

The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the first propylene-based polymer and the second propylene-based polymer measured according to ASTM D1238 (the second propylene-based polymer/the first propylene-based polymer ) Is 1.7 or more, and accordingly, the number of crimps in the crimped composite fiber nonwoven fabric may be 29ea/10mm or less.

Each of the first propylene-based polymer and the second propylene-based polymer independently of each other further includes 1 to 5% by weight of a softener in addition to the propylene-based polymer component as a main component, and the Silksoft coefficient of friction may be 0.45 or less.

In addition, the nonwoven fabric may further include 1 to 5% by weight of a softener.

The softener may include a fatty acid amide having 5 to 25 carbon atoms.

The fatty acid amide may include oleic acid amide, erucamide, stearic acid amide, or a combination thereof.

The first propylene-based polymer and the first propylene-based polymer may be prepared using a highly stereoregular polymerization catalyst.

The high stereoregular polymerization catalyst may include a diester component catalyst, a succinate component catalyst, a metallocene catalyst, or a combination thereof.

In addition, by further including the nucleating agent in addition to the propylene-based polymer component in which the first propylene-based polymer is a main component, the crystallization temperature of the first propylene-based polymer is increased to differentiate it from the recrystallization temperature of the second propylene-based polymer. By improving the thickness of the nonwoven fabric according to the expression, it is possible to further improve the softness and bulkiness of the nonwoven fabric.

The nucleating agent may include a granular additive, a self-assembled nucleating agent, a reactive nucleating agent, or a combination thereof. The granular additive may include sodium benzoate, titanium dioxide, silica, nano clay, sodium salt, calcium titanate, metal oxide, metal hydroxide, or a combination thereof. The self-assembled nucleating agent may include bis(p-methylbenzylidene)sorbitol, dibenzylidene sorbitol, monobenzylidene sorbitol (MBS), bis(p-methylbenzylidene)sorbitol, derivatives thereof, or combinations thereof. . The reactive nucleating agent may include a metal salt, 4-biphenyl carboxylic acid, 4-biphenylmethanol, adipic acid, or a combination thereof.

The nonwoven fabric containing the conjugated fiber may be obtained by a conventional composite melt spinning method without using a special device, for example, it may be a spunbond nonwoven fabric manufactured by a spunbonding method having excellent productivity.

Hereinafter, a method of manufacturing the spunbond nonwoven fabric will be described in detail.

First, the first propylene-based polymer forming one region of the composite fiber and the second propylene-based polymer forming the other region are separately melted with an extruder, etc., and the composite spinning is configured to form and discharge a desired fiber structure. Each melt is discharged from a spinneret having a nozzle to release the composite long fibers.

Thereafter, the discharged long fibers are cooled by cooling air, and tension is applied by stretching air to give a predetermined fineness, and as it is, collected on a collection belt and deposited to a predetermined thickness.

Thereafter, post-processing is performed by means of a needle punch, water jet, ultrasonic wave, or the like, embossing using a heated embossing roll, or thermally fused by high-temperature ventilation.

In one embodiment of the present invention, the crimped composite fiber nonwoven fabric may be formed by heat-sealing by embossing.

The embossing process may be performed under conditions of a bonding rate (ie, an embossing area rate) of 13% or less, and a non-embossing unit area of 0.2 mm ² or more, for example, 0.2 to 0.7 mm ² . Here, the non-embossing unit area means the largest area of a square inscribed to the embossing in the non-embossing unit of the smallest unit surrounded by the embossing unit on all sides. When embossing is performed under the conditions of this range, a nonwoven fabric having a larger bulky property can be obtained while maintaining the necessary nonwoven fabric strength.

The bonding rate and the non-embossing unit area can be adjusted by changing the embossing pattern.

As a result of the embossing process, the crimped composite fiber nonwoven fabric includes an embossing portion and a non-embossing portion, and the embossing portion may include a plurality of unit embossing pattern portions successively arranged at the same or different intervals in an open embossing type.

1, a partial view showing an embossing pattern of a nonwoven fabric 10 made of a crimped composite fiber according to an embodiment of the present invention. Referring to FIG. 1, a nonwoven fabric 10 made of crimped composite fibers according to an embodiment of the present invention includes an embossing portion 11 and a non-embossing portion 12.

2 is a partial view showing an embossing pattern of a nonwoven fabric 20 of a crimped composite fiber according to another embodiment of the present invention. Referring to FIG. 2, the nonwoven fabric 20 of crimped composite fiber according to another embodiment of the present invention includes an embossing portion 21 and a non-embossing portion 22.

The fineness and basic weight of the crimped composite fiber nonwoven fabric may be appropriately selected according to the application, and the fineness is usually 1.0 to 2.5 denier, for example, 0.7 to 2.0 denier, and the basis weight is 15 to 100 g/m ² , For example, it may be 7 to 30 g/m ² .

In addition, each embossing pattern included in the unit embossing pattern portion may have an area of 0.2 to 0.7 mm ² .

In addition to the first propylene-based polymer and the second propylene-based polymer, the composite fiber may contain other components as necessary within a range not impairing the object of the present invention. The other ingredients may include known heat-resistant stabilizers, weather-resistant stabilizers, various stabilizers, antistatic agents, anti-blocking agents, anticlouding agents, fillers, dyes, pigments, natural oils, synthetic oils, waxes, or combinations thereof. .

The stabilizer may be an anti-aging agent such as 2,6-di-t-butyl-4-methylphenol (BHT); Tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, β-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid Phenolic antioxidants such as alkyl esters and 2,2'-oxamidobis[ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; Fatty acid metal salts such as zinc stearate, calcium stearate, and calcium 1,2-hydroxystearate; Polyhydric alcohol fatty acid esters such as glycerin monostearate, glycerin distearate, pentaerythritol monostearate, pentaerythritol distearate and pentaerythritol tristearate; Or a combination thereof.

The fillers are silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balun, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, talc, clay, mica , Asbestos, calcium silicate, montmorillonite, bentonite, graphite, aluminum powder, molybdenum sulfide, or a combination thereof.

The above-described propylene-based polymer and the other components used as necessary may be mixed using a known method.

The composite fiber may be a mono-type (Mono), a core-sheath (Core/sheath), a side-by-side type (Side-by-side) or a sandwich-type (Sandwitch) composite fiber.

For example, the conjugated fiber is a side-by-side type conjugated fiber having a thickness direction cross section including a first section made of the first propylene-based polymer and a second section made of the second propylene-based polymer, and the first section May be smaller than the second cross section.

Hereinafter, a nonwoven fabric laminate according to an embodiment of the present invention will be described in detail.

The nonwoven fabric laminate according to an embodiment of the present invention is a laminate having at least two or more layers, and at least one of them may be the aforementioned nonwoven fabric.

The nonwoven fabric laminate may include a spunbond nonwoven fabric among the aforementioned nonwoven fabrics.

For example, the nonwoven fabric of the crimped composite fiber may be a spunbond nonwoven fabric, and the nonwoven fabric laminate may be configured such that the spunbond nonwoven fabric is exposed only on one surface of both surface layers.

In addition, the nonwoven fabric laminate may be formed by stacking four spunbond nonwoven fabrics, and in this case, the nonwoven fabric laminate may have a uniformity (CV%) of 3% or less. In the present specification, "uniformity (CV%)" refers to the percentage of the value obtained by dividing the weight deviation of the 30 test pieces by the average weight of the plurality of test pieces after cutting the nonwoven fabric laminate to a size of 1 m ² to make 30 test pieces. it means.

The nonwoven fabric laminate formed by laminating four spunbond nonwoven fabrics has a thickness of 0.02mm or more, a crimp number of 10/10mm or more, a bonding rate of 13% or less, and an MD strength showing the softness of the nonwoven fabric laminate. (MD stiffness) may be 40 mm or less. In the present specification, "MD strength" refers to the bending deformation in the machine direction of the nonwoven fabric laminate (ie, the degree to which the nonwoven fabric laminate is bent).

Hereinafter, an article according to an embodiment of the present invention will be described in detail.

An article according to an embodiment of the present invention includes the above-described nonwoven fabric laminate.

The article may be a diaper, absorbent article, toilet article, support layer or top sheet.

When the article is a diaper, the nonwoven fabric laminate may have a hydrophilic agent impregnation amount (OPU: Oil Pick-UP) of 0.7% or less, so that the water absorption rate when applied to the top sheet layer of the diaper may be 3 sec or less.

The hydrophilic agent impregnation amount (OPU) may be calculated according to Equation 1 below.

[Equation 1]

OPU(%) = (W1-W0)/W0 X 100

In the formula, W0 is the weight of the nonwoven fabric laminate containing no hydrophilic agent, and W1 is the weight of the nonwoven fabric laminate (solid content only) containing the hydrophilic agent. In addition, in Equation 1, W1 is a value obtained by summing the weight of the nonwoven fabric laminate not containing the hydrophilic agent and the weight of only the solid component of the hydrophilic agent. As the hydrophilic agent, an emulsion-type hydrophilic agent (Zschimmer, Lertisan HD 20/3, docusate sodium-containing material) having a concentration of 2.0 to 5.0% by weight may be used.

Hereinafter, the present invention will be described in more detail through examples. The present examples are for explaining the present invention more specifically, and the scope of the present invention is not limited to these examples.

Examples 1 to 6 and Comparative Examples 1 to 10

The first propylene polymer (A) to which an erucamide softener or/and a nucleating agent (MBT, NB3010C, sodium benzoate-containing material) is added (the first component) and the second propylene polymer to which the erucamide softener is added (B ) (Second component) was used to perform composite melt spinning by spun bonding to deposit the side-by-side composite fiber (1) having the configuration of FIG. 3 on the collection surface, and embossing as shown in FIG. A nonwoven fabric including a crimped composite fiber was prepared by embossing using a calender roll heated to a top temperature of 155°C and a bottom temperature of 150°C by the pattern. Here, adding a nucleating agent (MBT, NB3010C, sodium benzoate-containing material) to the first propylene-based polymer (A) sets the crystallization temperature of the first propylene-based polymer (A) to the second propylene-based polymer (B) It is to give it higher than 19 degreeC. Here, the addition of an erucamide softening agent to the first propylene-based polymer (A) and the second propylene-based polymer (B), respectively, is to improve the Silksoftness of the nonwoven fabric. The types, properties and content ratios of the first and second propylene-based polymers (B), the content of the nucleating agent, the content of the erucamide softener, and the characteristics of the embossing pattern are shown in Table 1 below. In Table 1 below, MFR refers to a melt index measured under conditions of a temperature of 230° C. and a load of 2.16 kg according to ASTM D1238.

			Example						Comparative example
			One	2	3	4	5	6	One	2	3	4	5
First ingredient	polymer		PA1	PA2	PA3	PA4	PA5	PA1	PA1	PA6	PA7	PA1	PA1
	Melting point(℃)		130	120	100	130	130	130	130	140	130	130	130
	MFR (g/10min)		35	35	35	30	20	35	35	35	35	35	35
	Crystallization temperature (℃)		129	129	129	129	129	129	110	110	110	110	110
	Nucleating agent content (% by weight)		5	5	5	5	5	5	0	0	0	0	0
	Softener content (% by weight)		4	4	4	4	4	4	One	One	One	One	One
Second component	polymer		PB	PB	PB	PB	PB	PB	PB	PB	PB	PB	PB
	Melting point(℃)		160	160	160	160	160	160	160	160	160	160	160
	MFR (g/10min)		60	60	60	60	60	60	60	60	35	60	60
	Crystallization temperature (℃)		110	110	110	110	110	110	110	110	110	110	110
	Softener content (% by weight)		4	4	4	4	4	4	One	One	One	One	One
Melting point difference of the first and second components (℃)			30	40	60	30	30	30	30	20	30	30	30
MFR ratio of the first and second components			1.7	1.7	1.7	2.0	3.0	1.7	1.7	1.7	1.0	1.7	1.7
MWD ratio of the first and second components			1.5	1.5	1.5	2.0	3.0	1.5	1.5	1.5	1.0	1.5	1.5
Crystallization temperature difference (℃)			19	19	19	19	19	19	0	0	0	0	0
1st/2nd component ratio (weight ratio)			50/50	50/50	50/50	50/50	50/50	10/90	90/10	50/50	50/50	5/95	60/40
Nucleating agent content (% by weight)			5	5	5	5	5	5	0	0	0	0	0
Embossing pattern		Bonding rate (%)	12	12	12	12	12	12	12	12	12	12	12
		Non-embossing unit area (mm 2 )	22.944	22.944	22.944	22.944	22.944	22.944	22.944	22.944	22.944	22.944	22.944
			Comparative example
			6		7		8		9		10
First ingredient	polymer		PA1		PA6		PA7		PA1		PA1
	Melting point(℃)		130		140		130		130		130
	MFR (g/10min)		35		35		35		35		35
	Crystallization temperature (℃)		129		129		129		129		129
	Nucleating agent content (% by weight)		5		5		5		5		5
	Softener content (% by weight)		4		4		4		4		4
Second component	polymer		PB		PB		PB		PB		PB
	Melting point(℃)		160		160		160		160		160
	MFR (g/10min)		60		60		35		60		60
	Crystallization temperature (℃)		110		110		110		110		110
	Softener content (% by weight)		4		4		4		4		4
Melting point difference of the first and second components (℃)			30		20		30		30		30
MFR ratio of the first and second components			1.7		1.7		1.0		1.7		1.7
MWD ratio of the first and second components			1.5		1.5		1.5		1.5		1.5
Crystallization temperature difference (℃)			19		19		19		19		19
1st/2nd component ratio (weight ratio)			90/10		50/50		30/70		5/95		60/40
Nucleating agent content (% by weight)			5		5		5		5		5
Embossing pattern		Bonding rate (%)	12		12		12		12		12
		Non-embossing unit area (mm 2 )	22.944		22.944		22.944		22.944		22.944

In Table 1, PA1 to PA7 and PB mean the following, respectively.

(1) PA1: a mixture of 70% by weight of a propylene homopolymer (LG Chemical, H7700) and 30% by weight of an elastomer-based random copolymer in which ethylene is copolymerized with polypropylene (LG Chemical, T-7700)

(2) PA2: a mixture of 60% by weight of a propylene homopolymer (LG Chemical, H7700) and 40% by weight of an elastomer-based random copolymer in which ethylene is copolymerized with polypropylene (EXXON, VISTAMAXX 7020)

(3) PA3: a mixture of 40% by weight of a propylene homopolymer (LG Chemical, H7700) and 60% by weight of an elastomeric random copolymer in which ethylene is copolymerized with polypropylene (DOW, VERSIFY 4200)

(4) PA4: a mixture of 70% by weight of a propylene homopolymer (LG Chemical, H7700) and 30% by weight of an elastomeric random copolymer in which ethylene is copolymerized with polypropylene (LG Chemical, T-7700)

(5) PA5: a mixture of 70% by weight of a propylene homopolymer (LG Chemical, MH7700) and 30% by weight of an elastomeric random copolymer (LG Chemical, T-7700) copolymerized with ethylene in polypropylene

(6) PA6: a mixture of 60% by weight of a propylene homopolymer (LG Chemical, MH7700) and 40% by weight of an elastomeric random copolymer in which ethylene is copolymerized with polypropylene (LG Chemical, T-7700)

(7) PA7: a mixture of 70% by weight of a propylene homopolymer (LG Chemical, H7700) and 30% by weight of an elastomeric random copolymer in which ethylene is copolymerized with polypropylene (LG Chemical, T-7700)

(8) PB: propylene homopolymer (PMC, H562T)

Evaluation Example: Evaluation of properties of spunbond nonwoven fabric

The properties of the spunbond nonwoven fabrics prepared in Examples 1 to 6 and Comparative Examples 1 to 10 were evaluated in the following manner, and the results are shown in Table 2 below.

(1) Weight per unit area (weight: g/m ² ): It was measured according to ASTM D 3776-1985.

(2) Tensile strength: The maximum tensile load was obtained by performing a tensile test under the conditions of a width of 5 cm, an interval of 10 cm, and a tensile speed of 500 mm/min according to KSK 0520 method using a tensile strength elongation device (Instron) measuring equipment.

(3) Tensile elongation: The elongation at maximum elongation measured by the method of (2) was calculated.

(4) Silksoftness index (COF: coefficient of friction): When a force is applied to a stationary object, the friction force is proportional to the component force in the vertical direction of the object.At this time, the proportional constant is called the static friction coefficient, and the static friction coefficient is It is determined according to the state of the object and the contact surface. The static friction coefficient was measured according to KS M 3009.

(5) Thickness (mm): It was measured according to the method of KSK 0506.

(6) Number of crimps: The number of filament crimps within the range of 10 mm was directly measured using a microscope.

(7) Spinning: Filament shaking was observed with the naked eye during melt spinning, and polymer drip was detected with a defect detector.

	Example						Comparative example
	One	2	3	4	5	6	One	2	3	4	5
Tensile strength (MD)(kgf/5cm)	3.63	4.00	3.79	4.27	3.33	4.07	3.51	3.00	2.88	2.74	3.17
Tensile strength (CD)(kgf/5cm)	2.13	2.44	2.31	2.86	1.66	2.61	1.89	1.28	1.20	1.02	1.57
Tensile elongation (MD)(%)	103	104	112	112	115	110	97	104	99	109	97
Tensile elongation (CD)(%)	110	110	117	114	128	116	109	114	109	118	105
Silksoft property index (C.O.F)	0.37	0.38	0.37	0.36	0.32	0.35	0.49	0.52	0.53	0.50	0.49
Thickness(mm)	0.45	0.45	0.51	0.53	0.57	0.49	0.30	0.42	0.22	0.43	0.26
Number of crimps (pcs/10mm)	13	14	18	23	29	18	4	7	0	8	11
Radioactive	Good	Good	Good	Good	Good	Good	Good	Good	Good	Good	Good
	Comparative example
	6		7		8		9		10
Tensile strength (MD)(kgf/5cm)	3.55		3.56		3.37		3.04		3.29
Tensile strength (CD)(kgf/5cm)	1.78		1.82		1.70		1.32		1.72
Tensile elongation (MD)(%)	98		100		110		102		102
Tensile elongation (CD)(%)	108		105		120		112		111
Silksoft property index (C.O.F)	0.43		0.46		0.47		0.49		0.48
Thickness(mm)	0.34		0.37		0.26		0.43		0.33
Number of crimps (pcs/10mm)	7		10		4		11		11
Radioactive	Good		Good		Good		Good		Good

Referring to Table 2, the nonwoven fabric of the crimped composite fibers prepared in Examples 1 to 6 has a thicker thickness compared to the nonwoven fabric of the crimped composite fibers prepared in Comparative Examples 1 to 10, and has a small Silksoftness Index (COF), It has a large number of crimps, and other properties such as tensile strength (MD: Machine direction), tensile strength (CD: Cross direction), tensile elongation (MD: Machine direction), tensile elongation (CD: Cross direction) and spinnability are excellent or similar. Appeared.

4 is a partial view showing the embossing pattern of the nonwoven fabric of the crimped composite fiber prepared in Example 4.

4, the nonwoven fabric of the crimped composite fiber prepared in Example 4 was found to have a crimp number of about 20/10 mm.

The present invention has been described with reference to the drawings and embodiments, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (15)

1. As a nonwoven fabric of crimped composite fibers comprising a first propylene polymer and a second propylene polymer,

   The first propylene-based polymer and the second propylene-based polymer have a melting point of the second propylene-based polymer measured by a differential scanning calorimeter (DSC) higher than the melting point of the first propylene-based polymer by 30°C or more, and the first propylene-based polymer The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the polymer and the second propylene polymer measured according to ASTM D1238 (the second propylene polymer/the first propylene polymer) is 1.7 or more And the ratio of the molecular weight distribution (MWD) measured by gel permeation chromatography (GPC) of the first propylene-based polymer and the second propylene-based polymer (the second propylene-based polymer/the first propylene-based polymer) is 1.5 The above, and the component ratio represented by the first propylene-based polymer / the second propylene-based polymer (weight ratio) is 50/50 to 10/90 crimped composite fiber nonwoven fabric.
2. The method of claim 1,

   The first propylene-based polymer further includes 1 to 5% by weight of a nucleating agent in addition to the propylene-based polymer component as a main component, and the crystallization temperature of the first propylene-based polymer is 19°C or higher than the crystallization temperature of the second propylene-based polymer. Crimped composite fiber nonwoven fabric.
3. The method of claim 1,

   The first propylene-based polymer includes a propylene homopolymer, and the second propylene-based polymer includes 70 to 90 parts by weight of a propylene homopolymer and 10 to 30 parts by weight of a propylene-ethylene-butylene terpolymer, and the propylene-ethylene -Butylene terpolymer is a crimped composite fiber nonwoven fabric comprising 90 to 95% by weight of propylene, 2.5 to 5.0% by weight of ethylene, and 1.5 to 5.0% by weight of butene.
4. The method of claim 1,

   The ratio of the melt index (MFR: measurement temperature 230°C, load 2.16 kg) of the first propylene-based polymer and the second propylene-based polymer measured according to ASTM D1238 (the second propylene-based polymer/the first propylene-based polymer ) Is 1.7 or more, and the number of crimps is 29ea/10mm or less.
5. The method of claim 1,

   The first propylene-based polymer and the second propylene-based polymer each independently contain 1-5% by weight of a softener in addition to the propylene-based polymer component, which is a main component, respectively, and a crimped composite having a Silksoft coefficient of friction of 0.45 or less Fiber non-woven fabric.
6. The method of claim 1,

   The crimped composite fiber is a mono-type, core sheath-type, side-by-side type or sandwich-type non-woven fabric of crimped composite fiber.
7. The method of claim 1,

   The crimped composite fiber nonwoven fabric includes an embossing portion and a non-embossing portion, and the embossing portion is an open embossing type, including a plurality of unit embossing pattern portions successively arranged at the same or different intervals.
8. The method of claim 7,

   Each embossing pattern included in the unit embossing pattern portion is a non-woven fabric of crimped composite fibers having an area of 0.2 to 0.7 mm ² .
9. The method of claim 7,

   The crimped composite fiber nonwoven fabric is a crimped composite fiber nonwoven fabric having a bonding rate of 13% or less.
10. The method of claim 1,

    The crimped composite fiber nonwoven fabric is a nonwoven fabric of a crimped composite fiber that is a spunbond nonwoven fabric.
11. A nonwoven fabric laminate having at least two or more layers, wherein at least one layer is a nonwoven fabric of the crimped composite fibers according to any one of claims 1 to 10.
12. The method of claim 11,

    The nonwoven fabric of the crimped composite fiber is a spunbond nonwoven fabric, and the nonwoven fabric laminate is configured such that the spunbond nonwoven fabric is exposed only on one side of both surface layers.
13. An article comprising the nonwoven laminate according to claim 11 or 12.
14. The method of claim 13,

    The article is a diaper, an absorbent article, a toilet article, a support layer or a top sheet.
15. The method of claim 14,

    When the article is a diaper, the non-woven fabric laminate has a hydrophilic agent impregnation amount (OPU) of 0.7% or less so that the water absorption rate when applied to the top sheet layer of the diaper is 3 sec or less.

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