JP3110694B2 - 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,
A liquid-impervious back sheet and a liquid-retentive absorber interposed between the two sheets, and a pair of fastening tapes for fastening a pair of diapers are arranged on the left and right side edges of the back side, Widely used. Recently, it has been proposed that the fastening tape itself has elasticity and stretchability in order to further improve the diaper's fit and leakage prevention.

[0003] However, when the fastening tape is provided with elastic elasticity, the fastening tape is formed of ordinary rubber or the like, so that the fastening tape hits the wearer's skin during wearing, and the wearer's skin is irritated. There was a problem. Further, the above-mentioned ordinary rubber has a problem that molding processability is poor and productivity is poor.

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 inventors of the present invention have made intensive studies to solve the above problems, and as a result, have found that a disposable diaper having a fastening tape formed of a specific copolymer can achieve the above object. did.

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. In a deployment type disposable diaper in which a pair of fastening tapes for fastening a diaper are disposed on left and right side edges of the side portion, the fastening tape has a permanent set of 0.
Is 30%, the hysteresis ratio is 1.0 to 3.5 Der
Using cyclopentadienyl complex as catalyst
An elastic member formed of an ethylene-α-olefin copolymer obtained by combining
Of the disposable diaper is connected to the back edge of the disposable diaper
The present invention provides a disposable diaper characterized by being made.

[0007] Further, the present invention provides the above-mentioned surface sheet,
A three-dimensional guard having a free end on the inner side of the diaper is formed by fixing the leak-proof sheet to the outer side of the diaper, and the elastic member is disposed on the free end. It is intended to provide disposable diapers. Also, the present invention
The ethylene-α-olefin copolymer has a density of 0.9
The present invention provides the above disposable diaper having a weight of 0 g / cm ³ or less . Also, the present invention, the elastic member is a sheet formed by the ethylene-.alpha. · olefin copolymer, the fastening tape is provided the disposable diaper having a composite sheet between the sheet and the nonwoven fabric Is what you do. Further, the present invention provides the above disposable diaper, wherein the fastening tape is provided with a convex member or a concave member of a mechanical fastener as a locking means thereof.

[0008]

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 the fastening tape is formed of a specific copolymer.

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 from the ethylene-α-olefin copolymer, and the sample was fixed to the tester so that the distance between the chucks was 100 mm. Then, each sample was formed at a speed of 300 mm / min. A stretching curve is created by stretching 100%, and then loosened at the same speed to stop loosening when the distance between the chucks reaches the initial length of 100 mm, and a relaxation curve is created. Under the stretching curve and under the relaxation curve, respectively. Were measured and the values 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.

[0011] The ethylene-.alpha. · olefin copolymer
It may satisfy the above permanent deformation and the hysteresis ratio,且
One Ru ethylene-.alpha. · olefin copolymer der made by copolymerization with a cyclopentadienyl complex as a catalyst.

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 a cyclopentadienyl group, a methylcyclopentadienyl group, a dimethylcyclopentadienyl group, a trimethylcyclopentadienyl group, and a 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 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 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 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.

The following are specific examples of the above compounds wherein M is zirconium. 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, the disubstituted cyclopentadienyl ring such as dimethylcyclopentadienyl includes 1,2- and 1,3-substituted compounds.
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.

The above 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 of 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 No.
A polymerization catalyst described in JP-A-84407 can also be used.

The mixing ratio of ethylene and 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 in the presence of a cyclopentadienyl complex to 100 to 3,000 kg / c.
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.

[0031] 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 in a 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 0.3 to 0.3.
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 surface friction coefficient 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.

[0040]

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 (non-woven 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 above lubricant, lubricants described in "Plastic Lubricity and Lubricant" (published by Nikkan Kogyo Shimbun, June 30, 1977) can be suitably 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 Jan. 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 plan view showing a back sheet side in one form of the disposable diaper of the present invention, and FIG. 2 is an enlarged perspective view showing a fastening tape in the disposable diaper shown in FIG. FIG. 3 is an enlarged perspective view showing another embodiment of the fastening tape used in the present invention.

The disposable diaper 1 of the present embodiment shown in FIG.
A liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid-retentive absorber 4 interposed between the two sheets 2 and 3; , A pair of fastening tapes 10 for fastening diapers is provided. A landing tape 9 for fastening the fastening tape is provided substantially at the center of the abdominal part A.

A three-dimensional guard 8 having a free end 8b on the inner side of the diaper is formed on the top sheet 2 by fixing the leak-proof sheet 8a to the outer side of the diaper. . 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 can be formed using a known material without any particular limitation.

The fastening tape 10 is
An elastic member 16 (see FIG. 2) formed of the ethylene-α-olefin copolymer having a permanent set and a hysteresis ratio in the above-mentioned ranges is provided.

More specifically, the fastening tape 10 is fixed to the tape body 11 and the top sheet 2 of the diaper so that the surface thereof can be peeled off. And a release tape (not shown) for abutting the surface to which the surface is applied to protect the surface. As shown in FIG. 1, the tape main body 11 has a base end portion 12 fixed to the back sheet 3 and a locking portion 1 formed by applying an adhesive to one surface (top sheet side).
3, a telescopic part 15 formed by disposing the elastic member 16 (see FIG. 2), and a knob part 14 formed by folding the tip. The structure of the fastening tape 10 will be described in more detail with reference to FIG.
2 and the elastic portion 15 are integrally formed of the same material, and the elastic portion 15 and the locking portion 13 are connected via a joining portion 18.

Then, the base end portion 12 and the elastic portion 15
Is formed by a composite sheet in which a nonwoven fabric 17 is adhered to both sides of a sheet-like elastic member 16. That is, the elastic member 16 is a film-like sheet formed of the ethylene-α-olefin copolymer, and the fastening tape 10 is formed of the sheet (elastic member 16).
And a nonwoven fabric 17. Here, as the nonwoven fabric 17, a nonwoven fabric which can be extended in at least one direction such as a known nonwoven fabric having a large number of small folds or a spunlace nonwoven fabric can be used. Can be used so as to be along the longitudinal direction of the fastening tape 10, thereby making it possible to make the fastening tape 10 excellent in tactile sensation without impairing the elasticity of the elastic member 16. In this embodiment, a nonwoven fabric having a large number of the small folds is used.

The above-mentioned composite sheet is formed into a sheet by forming a fiber made of ethylene-α-olefin into a non-woven fabric by a spun bond method or a melt blow method, and a card web is laminated on the obtained sheet and both are entangled by a high-pressure water flow. hand,
It can be obtained by integrating. The locking portion 13 is formed of a film sheet and an adhesive used for a normal fastening tape. The joining portion 18 is formed by joining the elastic portion 15 and the locking portion 13 using a normal joining method without any particular limitation. In the present embodiment, one end of the elastic portion 15 is used. And one end of the locking portion 13 are partially bonded by, for example, being partially heated and fused.

The base end 12 may be joined to the back side by partially bonding it by heat-sealing or the like, or by heat embossing or ultrasonic sealing. You may join.

When the diaper is worn, elastic members 20 and 30 are also provided on the waist portion 5 located on the waist of the wearer and the leg portion 6 located around the legs, respectively. 30 is also formed of the above-mentioned ethylene-α-olefin. Further, also in the three-dimensional guard 8, an elastic member 40 made of the above-described ethylene-α-olefin copolymer is disposed at the free end 8b. The elastic member 40 is covered with the leak-proof sheet 8a at the free end 8b on the inner side of the diaper in the three-dimensional guard 8 by folding the edge of the leak-proof sheet 8a into a tubular shape. .

Since the disposable diaper according to the present embodiment is configured as described above, the diaper can be fixed by extending the locking portion 13 of the tape main body 11, and has excellent fitting properties and leakage prevention. It is excellent and has little 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.

Next, another embodiment of the fastening tape used for the disposable diaper of the present invention will be described in detail with reference to FIG. Fastening tape 1 of the form shown in FIG.
In the case of 0A, the base end portion 12 is widened, and the expansion and contraction portion 15 is formed to be wider toward the base end portion 12 side, thereby further improving the fitting property. The other points are the same as those of the fastening tape of the embodiment shown in FIGS. 1 and 2 described above, and the above description is appropriately applied.

The disposable diaper of the present invention is not limited to the form shown in FIG. 1 and can be variously modified without departing from the spirit of the present invention. For example, the elastic member 16 does not need to be the above-mentioned ethylene-α-olefin copolymer in the form of a film, but may be in the form of a non-woven fabric (fiber aggregate).
-It may be formed of an olefin copolymer. Further, the entire fastening tape 10 may be formed of the ethylene-α-olefin copolymer, that is, the entirety may be formed as a stretchable portion,
For example, in the above-described embodiment, only the tape main body 11 is formed of the ethylene-α-olefin copolymer, and the release tape is formed of another normal film material or two normal film materials. Alternatively, a fastening tape having elasticity in the longitudinal direction may be formed by sandwiching a rubber-like ethylene-α-olefin copolymer. In addition, instead of the above-mentioned adhesive, the fastening tape 10 includes a convex member or a concave member of a mechanical fastener on the front side of the locking portion (the surface sheet side of the diaper) as a locking means. It may be. As the convex member or the concave member used at this time, a normal convex member or a concave member can be used without any particular limitation.
When the convex member is used as the locking means, the landing tape 9 is a concave material, and when the concave material is used as the locking means, the landing tape 9 is a convex member. is there.

[0059]

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., Ltd.); 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) as an elastic member. In the obtained disposable diaper, the fastening tape showed good elasticity, and a wearing test was conducted by 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, the fastening tape showed good elasticity, but the 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 ”80% permanent strain, hysteresis ratio 7.0, blocking strength [24 hours] = 3 g / 55 mm, blocking strength [4 weeks] = 20 g / 55 mm, adhesive strength = 30
A disposable diaper was manufactured in the same manner as in Example 1 except that 0 g / 30 mm and a surface friction coefficient = 0.15) were used. The obtained disposable diaper did not cause skin irritation, but did not impart elasticity to the fastening tape. That is, the low-density polyethylene did not exhibit elasticity. The results are shown in [Table 1].

[0063]

[Table 1]

[0064]

The disposable diaper according to the present invention has a good fit.
Excellent in skin irritation and excellent in moldability.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view showing a back sheet side in one embodiment of a disposable diaper according to the present invention.

FIG. 2 is an enlarged perspective view schematically showing a fastening tape in the disposable diaper shown in FIG.

FIG. 3 is an enlarged perspective view schematically showing another embodiment of the fastening tape used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Back sheet 4 Absorber 10 Fastening tape 11 Tape main body 12 Base end 13 Locking part 14 Knob part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B32B 27/32 (72) Inventor Akihiko Gunji 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Pref. Kao Corporation Research Institute (72) Inventor Haruo Sakahashi 2606 Akabane, Kaiga-cho, Haga-gun, Tochigi Prefecture Kao Corporation Research Institute (56) References JP-A-7-24005 (JP, A) JP-A-63-21904 (JP, A) JP-A-5-293134 (JP, A JP-A-6-9724 (JP, A) JP-A-5-272043 (JP, A) JP-A-6-55623 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61F 13/49 A61F 5/44 A61F 13/58 B32B 27/00 B32B 27/12 B32B 27/32

Claims (5)

(57) [Claims] 1. A diaper comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorber interposed between the two sheets, and a pair of diapers on left and right side edges of a back side. In the deployable disposable diaper on which the fastening tape for fastening is arranged, the fastening tape has a permanent set of 0 to 30%.
, And the hysteresis ratio Ri der 1.0 to 3.5, the consequent
Copolymerization using lopentadienyl complex as catalyst
An elastic member formed of the obtained ethylene-α-olefin copolymer is provided , and the base end of the elastic member is
Disposable diaper characterized that you have been joined to the side edges of the back side of the disposable diaper. 2. A three-dimensional guard having a free end on the inner side of the diaper formed by fixing the leak-proof sheet to the outer side of the diaper is provided on the top sheet. The disposable diaper according to claim 1, wherein the elastic member is disposed on the diaper. 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 sheet according to claim 1, wherein the elastic member is a sheet formed of the ethylene-α-olefin copolymer, and the fastening tape includes a composite sheet of the sheet and a nonwoven fabric. The disposable diaper according to 1. 5. The disposable diaper according to claim 1, wherein the fastening tape includes a convex member or a concave member of a mechanical fastener as a locking means.