JP3110693B2 - Disposable diapers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable diaper having excellent fit, low skin irritation and good moldability.

[0002]

2. Description of the Related Art Conventionally, disposable diapers include liquid-permeable topsheets,
With a liquid-impermeable back sheet and a liquid-retentive absorber interposed between both sheets, the waist and the leg,
In each case, an elastic member is widely used in order to enhance the fit of the diaper and improve the leakage prevention.

[0003] However, such a disposable diaper has a problem that the skin of the wearer is irritated because the elastic member used is formed of ordinary rubber or the like. In addition, the above-described ordinary rubber has a problem that the productivity of the diaper is inferior due to poor molding processability.

Accordingly, it is an object of the present invention to provide a disposable diaper having excellent fit, low skin irritation, and excellent moldability.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the disposable diaper in which an elastic member formed of a specific copolymer is disposed at a waist portion or the like is described. It was found that the purpose could be achieved.

The present invention has been made based on the above findings, and comprises a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorber interposed between the two sheets. At least one of a part, a leg part, a waist part positioned around the wearer's waist when worn, and a three-dimensional guard formed by fixing the leak-proof sheet to the outer side of the diaper.
In the disposable diaper in which the elastic member is disposed at three places , the elastic member has a permanent set of 0 to 30% and a hysteresis ratio of 1.0 to 3.5.
An object of the present invention is to provide a disposable diaper characterized by being formed of an α-olefin copolymer.

[0007] The present invention also provides the disposable diaper, wherein the elastic member is disposed at a free end on the inner side of the diaper in the three-dimensional guard.

The present invention also provides the above disposable diaper, wherein the ethylene-α-olefin copolymer has a density of 0.90 g / cm ³ or less. The present invention also provides the disposable diaper, wherein the ethylene-α-olefin copolymer is a copolymer obtained by copolymerizing a cyclopentadienyl complex as a catalyst. Further, the present invention provides the above disposable diaper, wherein the ethylene-α-olefin copolymer is a copolymer obtained by copolymerizing using a metallocene catalyst.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the disposable diaper of the present invention will be described in more detail. The disposable diaper of the present invention is characterized in that an elastic member formed of a specific copolymer is arranged at at least one of a waist portion, a leg portion, a waist portion, and a three-dimensional guard.

The above specific copolymer used in the disposable diaper of the present invention has a permanent set of 0 to 30%.
And the hysteresis ratio is 1 . 0-3.5 ethylene-
It is an α-olefin copolymer. The above permanent distortion is preferred
Ku by 50% or less, it is possible to wide Ku fixable region of the elastic member, the hysteresis ratio
Responsiveness is improved by preferably being 5.0 or less. On the other hand, if the permanent set exceeds 50% or the hysteresis ratio exceeds 5.0, the fit of the gather portion formed by the elastic member to the body is reduced.

The permanent set and the hysteresis ratio are as follows:
Each is measured as follows. Measurement method of permanent set: In the same manner as the measurement method of the hysteresis ratio described below, after the sample was stretched by 100%, the length of the sample when the initial chuck distance was measured, and the initial length when the sample was stretched by 100%. The ratio (%) of the non-relaxable length (length of the portion elongated and longer than the initial length) to the length (initial chuck distance) was determined, and this was defined as the permanent strain. Hysteresis ratio measurement method; To examine the elasticity of each sample,
The hysteresis ratio was measured using an elongation tester with an integrating device. That is, a sample having a width of 25 mm was prepared using the elastic member, and the sample was placed on the tester with a distance between chucks of 100 m.
m and then each sample is 300 mm /
100% stretching at a speed of 10 min to form a stretching curve, and then loosening at the same speed to make the gap between the chucks equal to the initial length of 10%.
Relaxation was stopped at 0 mm to form a relaxation curve, the area under the stretching curve and the area under the relaxation curve were measured, and these were substituted into the following equation to calculate the hysteresis ratio. Hysteresis ratio = Area under stretch curve / Area under relaxation curve Here, the hysteresis ratio of a true elastomer is 1.0
Therefore, when the hysteresis ratio of the sample is measured, a sheet, film, or filament having a hysteresis ratio of less than 5 is suitable as an elastic material for sanitary articles such as sanitary napkins.

The ethylene-α-olefin copolymer is not particularly limited as long as it satisfies the above-mentioned permanent distortion and the above-mentioned hysteresis ratio, but ethylene-α-olefin copolymerized by using a cyclopentanedienyl complex as a catalyst is used.・
Olefin copolymers are preferred.

In the ethylene-α-olefin copolymer, the α-olefin to be copolymerized with ethylene is an α-olefin having 3 to 30 carbon atoms, for example, propylene, 1-butene, 1- Examples include pentene, 1-hexene, 1-octene, 1-heptene, 4-methylpentene-1, 4-methylhexene-1, 4,4-dimethylpentene-1, and octadecene. Among these, 1-hexene, 1-octene, 1-heptene, 4
-Methyl-pentene-1 is preferably used.

In the ethylene-α-olefin copolymer, the cyclopentadienyl complex used as a catalyst when copolymerizing ethylene and α-olefin is a compound represented by the following formula (I): And the like.

ML _X (I) wherein M is a transition metal selected from the group consisting of Zr, Ti, Hf, V, Nb, Ta and Cr, and L is
A ligand coordinated to the transition metal, a group having a cyclopentadienyl skeleton, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 1 to 12 carbon atoms.
Roxy group, trialkylsilyl group having 1 to 12 carbon atoms, S
An O ₃ R group (R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom, and x is the same number as the valence of the above transition metal It is. However, when a plurality of Ls are coordinated, they may be different groups, but at least one is a group having a cyclopentadienyl skeleton. That is,
When x is 1, the L is a group having a cyclopentadienyl skeleton, and when x is 2 or more, at least one of the plurality of Ls has a cyclopentadienyl skeleton. Is a group having ]

Examples of the group having a cyclopentadienyl skeleton include, for example, cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, and tetramethylcyclopentadienyl group. Enyl group, pentamethylcyclopentadienyl group, ethylcyclopentadienyl group, methylethylcyclopentadienyl group, propylcyclopentadienyl group, methylpropylcyclopentadienyl group,
Alkyl-substituted cyclopentadienyl groups such as butylcyclopentadienyl group, methylbutylcyclopentadienyl group and hexylcyclopentadienyl group; or indenyl group, 4,5,6,7-tetrahydroindenyl group, fluorenyl And the like. Further, these groups may be substituted with a halogen atom, a trialkylsilyl group or the like.

As the above-mentioned group having a cyclopentadienyl skeleton, an alkyl-substituted cyclopentadienyl group is particularly preferable among those exemplified above.

When the compound represented by the general formula (I) contains two or more groups having a cyclopentadienyl skeleton, two of the groups having a cyclopentadienyl skeleton are It may be bonded via an alkylene group such as ethylene or propylene; a substituted alkylene group such as isopropylidene or diphenylmethylene; or a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group or a methylphenylsilylene group.

The hydrocarbon group having 1 to 12 carbon atoms includes an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group and the like. More specifically, the alkyl group includes a methyl group, Ethyl group, propyl group,
Examples of an isopropyl group and a butyl group include a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; examples of an aryl group include a phenyl group and a tolyl group; and examples of an aralkyl group include a benzyl group and a neophyl group. And the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group. Examples of the aryloxy group include a phenoxy group. Examples of the halogen atom include fluorine, chlorine, bromine, and iodine.

Examples of the SO ₃ R group include a p-toluenesulfonato group, a methanesulfonato group, and a trifluoromethanesulfonato group.

The compound containing such a group having a cyclopentadienyl skeleton, for example, when the valence of the transition metal is 4, is more specifically represented by the following formula (II).

R ² _k R ³ _l R ⁴ _m R ⁵ _n M (II) wherein M is the above-mentioned transition metal, and R ² is a group having a cyclopentadienyl skeleton (ligand ) And R ³ , R
⁴ and R ⁵ are a group having a cyclopentadienyl skeleton, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, a trialkylsilyl group, an SO ₃ R group, a halogen atom or a hydrogen atom, respectively. And k is an integer of 1 or more, and k + 1 + m
+ N = 4. ]

In the present invention, in the above formula (II), R
Compounds in which at least two of R ² , R ³ , R ⁴ and R ⁵ , for example, R ² and R ³ are groups (ligands) having a cyclopentadienyl skeleton are preferably used. Groups having a skeleton (eg, R ² and R ³ ) may be linked as described above.

Specific examples of the above compound in which M is zirconium are shown below. Bis (indenyl) zirconium dichloride, bis (indenyl) zirconium dibromide, bis (indenyl) zirconium bis (p-toluenesulfonato) bis 4,5,6,7-
(Tetrahydroindenyl) zirconium dichloride, bis (fluorenyl) zirconium dichloride, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) zirconium dibromide, ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) diphenylzirconium, ethylenebis ( (Indenyl) methylzirconium monochloride, ethylenebis (indenyl) zirconiumbis (methanesulfonato), ethylenebis (indenyl) zirconiumbis (p-toluenesulfonate), ethylenebis (indenyl) zirconiumbis (trifluoromethanesulfonate), ethylene Bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, isopropylidene (cyclopentane Enyl - fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl - methylcyclopentadienyl) zirconium dichloride, dimethylsilylene bis (cyclopentadienyl)
Zirconium dichloride, dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (dimethylcyclopentadienyl)
Zirconium dichloride, dimethylsilylenebis (trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconiumbis (trifluoromethanesulfonato), dimethylsilylenebis (4,5,6,6) 7-tetrahydroindenyl) zirconium dichloride, dimethylsilylenebis (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl)
Zirconium dichloride, methylphenylsilylenebis (indenyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dibromide, bis (cyclopentadienyl) methylzirconium monochloride, bis (cyclopentane Dienyl) ethyl zirconium monochloride, bis (cyclopentadienyl) cyclohexyl zirconium monochloride, bis (cyclopentadienyl) phenyl zirconium monochloride, bis (cyclopentadienyl) benzyl zirconium monochloride, bis (cyclopentadienyl) ) Zirconium monochloride monohydride, bis (cyclopentadienyl) methylzirconium monohydride, bis (cyclopentadienyl) Methyl zirconium, bis (cyclopentadienyl) diphenyl zirconium, bis (cyclopentadienyl) dibenzylzirconium, bis (cyclopentadienyl) zirconium methoxychloride, bis (cyclopentadienyl) zirconium ethoxycyclolide, bis (cyclopentane Dienyl) zirconium bis (methanesulfonato), bis (cyclopentadienyl) zirconiumbis (p-toluenesulfonato), bis (cyclopentadienyl) zirconiumbis (trifluoromethanesulfonato), bis (methylcyclopentadiene) Enyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium ethoxycyclolide, bis (dimethylcyclopen Dienyl) zirconium bis (trifluoromethanesulfonato), bis (ethylcyclopentadienyl) zirconium dichloride, bis (methylethylcyclopentadienyl) zirconium dichloride, bis (propylcyclopentadienyl) zirconium dichloride, bis (methylpropylcyclo) (Pentadienyl) zirconium dichloride, bis (butylcyclopentadienyl) zirconium dichloride, bis (methylbutylcyclopentadienyl) zirconium dichloride, bis (methylbutylcyclopentadienyl) zirconium bis (methanesulfonate), bis (trimethyl) Cyclopentadienyl) zirconium dichloride, bis (tetramethylcyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadi Enyl) zirconium dichloride, bis (hexylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylcyclopentadienyl)
Zirconium dichloride.

In the compounds exemplified above, disubstituted cyclopentadienyl rings such as dimethylcyclopentadienyl include 1,2- and 1,3-substituted ones,
Trisubstituted compounds such as dimethylcyclopentadienyl are 1,2,2
Includes 3- and 1,2,4-substitutes. Also propyl,
Alkyl groups such as butyl are n-, i-, sec-, te
It includes isomers such as rt-. Examples of the compound also include a cyclopentadienyl complex in which zirconium is replaced with titanium, hafnium, vanadium, niobium, tantalum, or chromium in the above-mentioned compound in which M is zirconium.

The above cyclopentadienyl complex is
When used, they can be used alone or as a mixture. It may be used after being diluted with a hydrocarbon or a halogenated hydrocarbon. In particular, in the present invention, as the cyclopentadienyl complex, a zirconocene compound in which the central metal atom is zirconium and whose ligand is a group having at least two cyclopentadienyl skeletons is preferably used.

Further, the cyclopentadienyl complex is
It can be used in combination with an ordinary aluminoxane compound or a compound which reacts with the cyclopentadienyl complex to form a stable anion.

The cyclopentadienyl complex catalyst used in the present invention is disclosed in JP-A-4-253711.
JP-A-4-279592, JP-T-6-50358
No. 5, JP-A-3-188092 or JP-A-2-18092.
The polymerization catalyst described in 84407 can also be used.

The mixing ratio of ethylene to α-olefin in the ethylene-α-olefin copolymer is preferably 40 to 98% by weight of ethylene, and preferably 60 to 2% by weight of α-olefin.

The ethylene-α-olefin copolymer is prepared by converting ethylene and α-olefin to 100 to 3,000 kg / c in the presence of a cyclopentadienyl complex.
m ² , preferably 300 to 2,000 kg / cm ² ,
It can be produced by polymerizing at a temperature of 25 to 250 ° C, preferably 150 to 200 ° C by a high pressure ionic polymerization method. In particular, when the above-mentioned cyclopentadienyl complex and the above-mentioned aluminoxane compound are used in combination, polymerization is disclosed in
JP-A-1-130314, JP-A-60-35006,
According to the methods described in JP-A-58-19309, JP-A-60-35008, JP-A-3-1630088, etc., and the above cyclopentadienyl complex and a stable anion reacted with the cyclopentadienyl complex Can be used in combination with the compounds which form the carboxylic acids described in EP 277,004, WO 92/0172.
Polymerization can be carried out according to the high-pressure ionic polymerization method described in JP-A No. 3 (Kokai) No. 3 and the like.

The molecular weight distribution of the ethylene-α-olefin copolymer is preferably such that the ratio Mw / Mn of the weight average molecular weight to the number average molecular weight measured by GPC is 4 or less, preferably 2 or less. Is more preferred. In addition, the MFR of the ethylene-α-olefin copolymer (JIS K-7
210; measured at 190 ° C. under a load of 2.16 kg) is preferably 0.01 to 300 g / 10 min, more preferably 0.1 to 150 g / 10 min, and particularly preferably 0.5 to 3 g.
0 g / 10 minutes.

[0032] The ethylene-.alpha. · olefin copolymer, its density is preferably at 0.90 g / cm ³ or less, and even more preferably 0.880~0.860g / cm ^3. If the density exceeds 0.90 g / cm ³ , the tensile strength and the feeling (fitness) decrease, which is not preferable. Here, the density is measured in the same manner as in the measurement of the density of a known polymer.

The ethylene-α-olefin copolymer has a blocking strength (blocking strength at 40 ° C. for 24 hours) of 30 in a 180 ° peel test.
g / 55 mm or less, preferably 15 g / 55 m
m or less, and most preferably 5 g / 55 mm or less. The lower limit of the blocking strength of the ethylene-α-olefin copolymer is not particularly limited, as the lower the lower the roll of the ethylene-α-olefin copolymer roll does not slip, the better. The blocking strength is 30 g / 55 mm
If it exceeds, when the sheet made of the ethylene-α-olefin copolymer is in a roll shape, it may be stuck between the overlapping sheets, and the sheet may not be able to be unwound. Is preferred.

The ethylene-α-olefin copolymer has an adhesive strength of 50 g / 180 ° peel test.
It is preferably at least 30 mm, and 100 g / 30 mm
More preferably, it is 150 to 600 g / 30.
mm is most preferred. The upper limit of the adhesive strength is not particularly limited, since it is preferable that the upper limit is large enough to cause the material constituting the diaper to be broken. Also,
If the adhesive strength is less than 50 g / 30 mm, the ethylene-α-olefin copolymer may be peeled off from the back sheet or the like during diaper assembly.
If it exceeds 0 g / 30 mm, the film of the ethylene-α-olefin copolymer may be plastically deformed.

That is, the above-mentioned blocking strength and the above-mentioned adhesive strength are physical properties required from the viewpoint of improving diaper productivity. The above-mentioned blocking strength and the above-mentioned adhesive strength are each measured as follows.

[Blocking Strength (Blocking Strength at 40 ° C. for 24 hours)] First, a measurement sample is prepared as follows. The ethylene-α-olefin copolymer is formed into a sheet having a thickness of 50 μm, and the sheet is cut into a strip of 50 × 55 mm to obtain a sample sheet. Two obtained sample sheets were stacked to obtain a sheet laminate, and a 10 kg load (170 mm × 11 mm) was placed on the sheet laminate.
0 mm), and 40 ° C./8
Obtain a measurement sample stored at 0% environmental conditions for 24 hours. In addition, in the said sheet laminated body, when the said sheet is rolled up in a roll form, it is piled up so that the mutually contacting surfaces as a front surface and a back surface of a roll may contact. Then
Using the obtained measurement sample, a 180 ° peel test is performed according to a conventional method under the following conditions, and the obtained value is defined as blocking strength. -Measuring machine: tensile tester (Tensilon), product name "RTA-100" manufactured by Orientec Co., Ltd.-Distance between chucks: 100 mm-Pulling speed: 300 mm / min-Return speed: 300 mm / min

[Adhesive Strength] First, a measurement sample is obtained as follows. A hot melt (specifically, a styrene rubber hot melt adhesive) is applied to a 30 × 100 mm strip-shaped polyethylene terephthalate film (PET film) at a basis weight of 30 g / m ² , and a 30 × 100 mm film is formed on the PET film. 30mm HM coating and 30x70mm PE
A T film part is formed. A 30 × 100 mm sample sheet is superimposed thereon so that the periphery thereof overlaps the periphery of the PET film, and thereafter, the sample is pressed at a pressure of 5 kg / cm ² for 5 seconds to obtain a measurement sample. That is, in this measurement sample, both the PET film and the sample sheet have a 30 × 30 mm square portion at one end bonded through the HM coating portion, and the remaining 30 × 70 mm.
The portion of mm is a non-adhesion region. Next, using the obtained measurement sample under the following conditions, 180
° A peel test is performed, and the obtained value is defined as the adhesive strength. -Measuring machine: Tensilon tensile tester, manufactured by Orientec Co., Ltd., product name "RTA-100"-Distance between chucks: 100 mm-Pulling speed: 300 mm / min-Return speed: 300 mm / min-PET film and The measurement was performed by pulling the end of the non-adhesion region with the sample sheet and pulling it.

The ethylene-α-olefin copolymer has a blocking strength (40%) when wound into a roll.
(Blocking strength after storage at 1 ° C. for one month) is preferably 200 g / 55 mm or less at 180 ° peel strength.
More preferably, it is 0 g / 55 mm or less. The lower limit of the above-mentioned blocking strength is not particularly limited, since the lower the better, the smaller the roll of the ethylene-α-olefin copolymer does not cause a roll deviation.
When the blocking strength exceeds 200 g / 55 mm, when the sheet made of the ethylene-α-olefin copolymer is formed into a roll, the sheet may be stuck between overlapping sheets, and the sheet may not be able to be unwound. Therefore, it is preferable to be within the above range. The blocking strength is measured as described below. That is, the ethylene-α-olefin copolymer was formed into a sheet having a thickness of 50 μm, and a roll obtained by winding the sheet 2000 m into a roll was heated at 40 ° C./80% in an environment of 4 ° C.
After storing for a week (28 days), remove the sheet
The sample was cut out in a state of being laminated, and a sample (55 × 100 mm) in a state of two laminated layers was obtained. The 180 ° peel strength of the obtained sample was measured using a Tensilon tensile tester (trade name “RTA-10” manufactured by Orientec Co., Ltd.).
0 "), and a blocking strength is obtained by a measurement using a conventional method (distance between chucks: 50 mm
(Tensile speed: 300 mm / min). The measured value is 50
The length was calculated by averaging five points measured in mm length.

Further, the ethylene-α-olefin copolymer preferably has a surface friction coefficient of 1.0 or less, more preferably 0.5 or less, and more preferably 0.3 to 0.5.
Most preferably, it is 0.05. In the present invention,
As described later, the ethylene-α-olefin copolymer can be used in various forms such as a sheet, a thread rubber, and a nonwoven fabric. When used as a sheet, at least one surface has a surface friction coefficient in the above range. Is preferably satisfied. When the surface friction coefficient exceeds 1.0, blocking tends to occur when the film is rolled.
It is preferable to be within the above range. To be used as an elastic member of a disposable diaper, the hot melt adhesiveness and the blocking of the roll formed by winding the film are in a preferable range, that is, the blocking strength and the adhesive strength are in the above range. However, from this point as well, it is preferable that the surface friction coefficient be within the above-mentioned range. In order to keep the surface friction coefficient within the above range, for example, the surface of the T-die chill roll can be appropriately adjusted by roughening the surface or embossing the surface.

The coefficient of surface friction was measured using a friction tester (trade name "KES-SE") manufactured by Kato-Tech Co., Ltd. using a friction element wound with SUS304 wire having a thickness of 0.5 mm. The measurement can be similarly performed on any of the sheet, the thread rubber, and the nonwoven fabric by a known method.

Further, as the above-mentioned ethylene-α-olefin copolymer, a copolymer obtained by copolymerization using a known metallocene catalyst by an ordinary method can also be used.

The elastic member made of the ethylene-α-olefin copolymer can be used in the form of a foamed sheet, a rubber thread, a fiber aggregate (nonwoven fabric), a film or the like. The foamed sheet, the thread rubber, and the fiber aggregate (nonwoven fabric) can be formed as follows, respectively. In order to make the above-mentioned foamed sheet, “Basics of plastic processing” (Polymer Society of Japan, March 1982)
Published on March 25) or "Technical overview of foamed plastics"
As described in (Information Development Co., Ltd., issued on July 30, 1989), the above ethylene-α-olefin copolymer was cross-linked by electron beam cross-linking, chemical cross-linking, etc., and further obtained. It can be carried out by foaming the obtained crosslinked product by various methods. Known thread forming methods described in "Polymer processing, making one point fiber" (Kyoritsu Shuppan Co., Ltd., published on October 15, 1992) and "Plastic processing basics" described above can be used as the thread rubber. Can be performed according to The film can be formed according to a known T-die method, an inflation method, or a film processing method described in “Basics of Plastic Processing”. The fiber aggregate (nonwoven fabric) can be formed by using a known method such as spunbonding, meltblowing, or flash spinning.

The ethylene-α-olefin copolymer used in the present invention can be used in combination with various lubricants and antiblocking agents as long as the desired effects of the present invention are not impaired.

As the lubricant, lubricants described in "Plastic Lubricity and Lubricant" (published by Nikkan Kogyo Shimbun, June 30, 1977) can be preferably used. System, fatty acid system, fatty alcohol system, fatty acid amide system, ester system, partial ester system, composite lubricant and the like.

Examples of the hydrocarbon-based lubricant include liquid paraffin, industrial white mineral oil, petrolactam, petroleum wax, synthetic paraffin, synthetic hard paraffin, synthetic isoparaffin petroleum hydrocarbon, odorless light hydrocarbon, microcrystalline wax, and polyethylene wax. , Polypropylene wax,
3 (2-xenosyl) -1,2 epoxypropane, polyethylene oxide wax, chlorinated paraffin, petroleum hydrocarbon resin and the like. Examples of the fatty acid-based lubricant include higher fatty acids having 12 to 22 carbon atoms. Examples of the fatty alcohol-based lubricant include propylene glycol, glycerin, triethylene glycol, mono- and dipentaethyritol, and a straight-chain aliphatic saturated monohydric alcohol having 8 to 18 carbon atoms. As fatty acid amide-based lubricants,
Examples thereof include amides of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids.
N-substituted amides such as N'-methylenebisamide and N, N'-ethylenebisamide are preferably used. Specifically, higher fatty acid amides having 12 to 22 carbon atoms, ethylenebisstearic acid amide, ethylenebisoleic acid amide, erucic acid amide, stearic acid amide, oleic acid amide, ricinoleic acid amide, linoleic acid amide, linoleic acid amide , Stearyl erucamide, oleyl palmitamide, lauric amide, palmitic amide, N-stearyl stearamide,
Examples include N-oleyl oleamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, N-oleyl palmitamide, and the like.

Examples of the ester lubricant and the partial ester lubricant include stearic acid esters of straight-chain alcohols having 2 to 16 carbon atoms, ethanediol montanic acid esters, and the like.
Butyl ricinoleate, ethyl palmitate, stearyl palmitate, dibutyl sebacate, 2-ethylhexyl adipate, n-octyl adipate, dioctyl sebacate, butyl tartrate, triethyl citrate, poly (1,3-butanediol, adipic acid) ) Esters, tributyl acetyl citrate, isooctyl epoxy stearate, glycerin monoacetate, triglyceride waxes such as hydrogenated edible oils and fats, hydrogenated macaque oil and the like. In addition, as the above lubricant, in addition to these,
Silicones such as methylhydrodienepolysiloxane, dimethylpolysiloxane and methylphenylpolysiloxane, and rosins such as gum rosin, wood rosin, tall oil rosin, dark tall oil rosin, dark wood rosin, partially hydrogenated rosin, fully hydrogenated rosin, etc. It can also be used.

Examples of the antiblocking agent include those described in “Latest Techniques for Functional Fillers” (CMC Co., Ltd., issued on January 26, 1990). , Oxides (silica, alumina, iron oxide, titanium oxide, magnesia, etc.), metal powders (copper, silver, nickel, stainless steel, iron, aluminum, etc.), carbonates (calcium carbonate, magnesium carbonate,
Zinc carbonate), hydroxides (aluminum hydroxide, magnesium hydroxide, etc.), silicates (glass, kaolin,
Talc, mica, wollastonite, etc.), sulfates (calcium sulfate, barium sulfate, etc.), carbon (carbon black, graphite, etc.), titanates (potassium titanate, barium titanate, etc.), nitrides (aluminum nitride, Silicon nitride, etc.), carbide (silicon carbide, titanium carbide, etc.), sulfide (molybdenum sulfide, zinc sulfide, etc.),
Phosphates (calcium phosphate, iron phosphate, etc.), ferrites (barium ferrite, calcium ferrite, etc.), wood flour, starch, various organic pigments, polystyrene-based fillers, nylon-based fillers, acrylic-based fillers and the like are effectively used. These anti-blocking agents may be appropriately selected in consideration of resin processing suitability and anti-blocking function.

Next, an embodiment of the disposable diaper of the present invention will be described in more detail with reference to the drawings. here,
FIG. 1 is a partially cutaway perspective view showing one mode of the disposable diaper of the present invention, and FIG. 2 is a developed view of FIG.

The disposable diaper 1 of this embodiment shown in FIGS. 1 and 2 has a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid-retentive absorbent sheet interposed between the sheets 2, 3. A three-dimensional guard 8 comprising the body 4, a waist part 5, a leg part 6, a waist part 7 positioned around the wearer's waist when worn, and a leak-proof sheet 8 a fixed to the outer side of the diaper, Elastic members 10, 20, 30, 40 are provided, respectively.

More specifically, the above disposable diaper 1
Is a pants-type disposable diaper in which the left and right side edges A1, A2 of the abdominal part A and the left and right side edges B1, B2 of the back part B are joined to each other, as shown in FIGS. . As shown in FIG. 2, the three-dimensional guard 8 is formed by fixing the leak-proof sheet 8 to the outer side of the diaper on the top sheet 2.
Is a free end 8 on the inner side of the diaper in the three-dimensional guard 8.
In (b), the end of the leak-proof sheet 8a is folded back into a tubular shape, so that the sheet is covered with the leak-proof sheet 8a. In addition, as the above-mentioned leakproof sheet, a generally known sheet can be used without any particular limitation, but a hydrophobic nonwoven fabric or a water-repellent nonwoven fabric is preferably used. Such a configuration is the same as a conventional disposable diaper, and each member other than the elastic member can be formed using a known material without any particular limitation.

The disposable diaper of the present embodiment shown in FIGS. 1 and 2 has the elastic members 10, 20, 30, 40.
Are each formed of an ethylene-α-olefin copolymer having a permanent set and a hysteresis ratio in the above ranges.

More specifically, the elastic members 10 disposed on the waist portion 5 are a thin band-shaped film, and the elastic members 20 disposed on the leg portions are formed of thread rubber. Are arranged.

Further, the elastic member 30 disposed on the waist portion 7 located around the wearer's torso when worn is in the form of a thread rubber, and the elastic member 30 is arranged along the circumferential direction of the diaper. Each of the four back sides B is provided, so that the waist gathers formed by the elastic members 30 are substantially continuous along the circumferential direction of the diaper. The elastic members 40 are in the form of thread rubber, and are disposed one by one on each of the left and right sides.

Each of the above elastic members 10, 20, 30, 40
Are fixed via an adhesive or the like in the same manner as a normal elastic member of a diaper.

Since the disposable diaper of the present embodiment is configured as described above, it is excellent in fitting properties, excellent in leak prevention properties, and less irritating to the skin. Further, the ethylene-α-olefin copolymer is excellent in molding processability and excellent in productivity.

Next, another embodiment of the disposable diaper of the present invention will be described in detail with reference to FIG. Here, FIG.
It is a top view showing other forms of a disposable diaper of the present invention. Note that points which are not described in detail are the same as those of the above-described embodiment shown in FIGS. 1 and 2, and the above-described description is appropriately applied.

The disposable diaper 1A of the present embodiment shown in FIG.
Comprises a liquid-permeable top sheet 2A, a liquid-impermeable back sheet 3A, and a liquid-retentive absorber 4A interposed between the two sheets 2A, 3A. ,
B2, a pair of fastening tapes 10 for wearing diapers
A, which is a so-called deployable diaper in which the waist portion 5A, the leg portion 6A, the waist portion 7A located around the wearer's waist when worn, and the leak-proof sheet 8aA are fixed to the outer side of the diaper. The elastic members 20A, 30A, 50A, and 40A are respectively arranged on the formed three-dimensional guard 8A. A landing tape 9A for fastening the fastening tape is provided substantially at the center of the abdomen A. Such a configuration is the same as a conventional disposable diaper, and each member can be formed using a known material without any particular limitation.

The disposable diaper according to the present embodiment shown in FIG. 3 includes the elastic members 20A, 30A, 50A, 40A.
Are each formed of an ethylene-α-olefin copolymer having a permanent set and a hysteresis ratio in the above ranges. In addition, the elastic member 50A has a
And four of the back side parts B are arranged, and three of the elastic members 50A provided on the back side part B are arranged so as to be connected to the fastening tape 10A. This configuration is the same as the embodiment shown in FIGS. 1 and 2 described above. The fastening tape 10A includes an elastic member formed of the ethylene-α-olefin copolymer having a permanent set and a hysteresis ratio in the above-described ranges.

More specifically, the fastening tape 10A comprises a tape body 11A and a top sheet 2 of a diaper.
A, and a release tape (not shown) for affixing the surface of the locking portion 13A to which the adhesive is applied to protect the surface when not in use. Consists of The tape main body 11A is shown in FIG.
As shown in the figure, the base end portion 12 fixed to the back sheet 3A
A, a locking portion 13A formed by applying an adhesive to one surface (top sheet side), the base end portion 12A and the locking portion 13
A and 15 A of elastic parts located between A and the knob | pick part 14A formed by folding the front-end | tip. Then, in the fastening tape 10A, the tape main body 11A
Is formed of a composite sheet in which a nonwoven fabric is adhered to both sides of a sheet-like elastic member. That is, the base end 1
2A, the expansion / contraction part 15A, the locking part 13A, and the knob part 14A are all formed of the composite sheet. In addition, as the sheet-like elastic member, the ethylene-
In addition to an elastic member made of an α-olefin copolymer, a generally known rubber member or the like can be used. Here, as the nonwoven fabric 17A, a nonwoven fabric that can be extended in at least one direction such as a known nonwoven fabric formed with a large number of small folds or a spunlace nonwoven fabric can be used, and the extensible direction is the fastening tape 10A. Can be arranged and used along the longitudinal direction. With such a configuration, the elastic member 1
Fastening tape 10 without impairing the stretchability of 6A
The touch feeling of A can be made excellent. In this embodiment, a nonwoven fabric having a large number of the small folds is used.

The composite sheet is formed into a sheet by forming the fiber comprising the ethylene-α-olefin copolymer into a nonwoven fabric by a spun bond method or a melt blow method, and a card web is laminated on the obtained sheet by a high pressure water flow. It can be obtained by confounding the two and integrating them.
As the adhesive used for the locking portion 13A, a normal adhesive can be used without any particular limitation.

The base end portion 12A may be joined to the back side portion by partially bonding such as by heat fusion or the like, or by heat embossing or ultrasonic sealing. You may join.

Since the disposable diaper according to the present embodiment is configured as described above, the elastic portion 15 of the tape main body 11A is provided.
The diaper can be fixed by extending the length A, and the diaper is excellent in fitting property and leak preventing property, and has less skin irritation even if the fastening tape hits the wearer during wearing. Further, the ethylene-α-olefin copolymer is excellent in molding processability and excellent in productivity.

The disposable diaper of the present invention is shown in FIGS.
The present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit of the present invention. For example, FIGS. 1 and 2 above
In the embodiment shown in the above, an example in which the elastic member is disposed at any of the waist portion, the leg portion, the waist portion, and the three-dimensional guard has been described, but in the present invention, in any one of these locations, It is sufficient that an elastic member made of the above-mentioned ethylene-α-olefin copolymer is provided. Further, an elastic member made of a normal elastic material can be arranged in a place where the elastic member made of the ethylene-α-olefin copolymer is not arranged.

[0064]

EXAMPLES The present invention will be described below in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 An ethylene-α-olefin copolymer polymerized using a cyclopentadienyl complex (“Engage EG8200” (trade name, manufactured by Dow Chemical Co.); specifically, ethylene-1-octene copolymer Polymer, M
FR = 5, density = 0.870 g / cm ³ , permanent set = 17
%, Hysteresis ratio = 2.0, blocking strength [24
Time] = 4 g / 55 mm, blocking strength [4 weeks]
= 30 g / 55 mm, adhesive strength = 150 g / 30 mm,
A disposable diaper shown in FIG. 1 was produced using a film having a surface friction coefficient of 0.2) and a thread rubber as elastic members. In the obtained disposable diaper, each elastic member showed good elasticity, and a wearing test was performed on 10 panelists. As a result, there was no skin irritation. The results are shown in [Table 1].

Comparative Example 1 A disposable diaper was manufactured in the same manner as in Example 1 except that polyurethane was used instead of the ethylene-α-olefin copolymer. The permanent set of this polyurethane was 14%, the hysteresis ratio was 2.5, and the blocking strength [24 hours] = 4 g / 55.
mm, blocking strength [4 weeks] = 80 g / 55 m
m, adhesive strength = 140 g / 30 mm, surface friction coefficient =
0.25. In the obtained disposable diaper, although each elastic member showed good elasticity, skin irritation was high in a wearing test performed under the same conditions as in Example 1. The results are shown in [Table 1].

[Comparative Example 2] Instead of the ethylene-α-olefin copolymer, a conventional low-density polyethylene (“LLD
PE ", permanent set 80%, hysteresis ratio 7.0, blocking strength [24 hours] = 3 g / 55 mm, blocking strength [4 weeks] = 20 g / 55 mm, adhesive strength = 3
A disposable diaper was manufactured in the same manner as in Example 1 except that 00g / 30 mm and a surface friction coefficient = 0.15) were used. Although the obtained disposable diaper did not cause skin irritation, no elasticity was imparted to each elastic member. That is,
The low-density polyethylene did not exhibit elasticity. The results are shown in [Table 1].

[0068]

[Table 1]

[0069]

Industrial Applicability The disposable diaper of the present invention has excellent fit, low skin irritation, and excellent moldability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one mode of a disposable diaper according to the present invention.

FIG. 2 is a development view of the disposable diaper shown in FIG.

FIG. 3 is a plan view showing another embodiment of the disposable diaper of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Back sheet 4 Absorber 5 Waist part 6 Leg part 7 Waist part 8 Three-dimensional guard 8a Leak-proof sheet 8b Free end 10,20,30,40 Elastic member A Abdominal part B Back side

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiko Gunji 2606 Kabane-cho Akabane, Haga-gun, Tochigi Prefecture, Japan Kao Co., Ltd. References JP-A-7-24005 (JP, A) JP-A-5-293134 (JP, A) JP-A-6-9724 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB A61F 13/49 A61F 13/15

Claims (5)

(57) [Claims] 1. A liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorber interposed between the two sheets, the waist part, the leg part, and the waist of the wearer when worn. In a disposable diaper in which an elastic member is disposed at at least one of a waist portion and a three-dimensional guard formed by fixing a leak-proof sheet to an outer side of the diaper, the elastic member has a permanent distortion. Is 0 to 30% , and a hysteresis ratio is 1.0 to 3.5 . The disposable diaper characterized by being formed from an olefin copolymer. 2. The disposable diaper according to claim 1, wherein the elastic member is disposed at an inner free end of the diaper in the three-dimensional guard. 3. The disposable diaper according to claim 1, wherein the ethylene-α-olefin copolymer has a density of 0.90 g / cm ³ or less. 4. The method according to claim 1, wherein the ethylene-α-olefin copolymer is a copolymer obtained by copolymerization using a cyclopentadienyl complex as a catalyst.
The disposable diaper described. 5. The disposable diaper according to claim 1, wherein the ethylene-α-olefin copolymer is a copolymer obtained by copolymerization using a metallocene catalyst.