JP4276044B2 - Shape-retaining material for diapers and diapers - Google Patents

Description

  The present invention relates to a diaper shape-retaining material and a diaper, and more particularly, to a diaper shape-retaining material capable of preventing sagging of an absorbent body due to urination or defecation and a diaper using the same.

  Conventionally, various types of diapers such as pants-type diapers and tape-type diapers are frequently used for excretion of urination and defecation of infants and the elderly.

  In the diaper as described above, it is required to prevent the absorber from sagging due to the weight of excrement such as urine and feces and to suppress the leakage of excrement. For example, Patent Document 1 discloses a disposable paper diaper. There is disclosed a disposable paper diaper in which an elastic lifting member for lifting an absorbent body, which is fixed to an absorbent body placement region along the longitudinal direction, is disposed.

  However, depending on the elastic modulus and expansion / contraction characteristics of the elastic elastic member as described above, it is not always possible to prevent the absorber from sagging, and the wearing feeling may deteriorate, or the excrement may not leak. There was a problem that it could not be done.

  In addition, depending on the material of the elastic elastic member, there has been a problem that environmental load becomes large, such as generation of harmful substances during incineration after disposal.

  In order to prevent sagging of the absorber as described above, for example, instead of the elastic elastic member or in combination with the elastic elastic member, when a metal shape retaining material is used, the metal one is Problems such as being easily rusted or deteriorated by moisture, problems that may cause damage to the body, problems that are detected by a metal detector when using an aircraft, problems that require time and labor to separate during disposal, etc. there were.

JP 2001-178771 A

  An object of the present invention is a resin diaper shape-retaining material in view of the above-mentioned conventional problems, which can prevent sagging of the absorbent body due to urination and defecation and leakage of excrement, and has a low environmental impact during disposal. The object is to provide a shape-retaining material for diapers that can be easily incinerated or recycled and a diaper using the same.

The shape retaining material for diapers according to claim 1 is a stretched olefin resin sheet having a tensile modulus of 10 GPa or more and a stretch ratio of 13 to 40 times, and the sheet shape is changed, for example, by bending the sheet. It has a shape-retaining property which means that it has a plastic deformability that keeps its shape .

The shape-retaining material for diapers according to claim 2 is characterized by comprising a laminated sheet in which a thermoplastic resin film is laminated on at least one side of the stretched olefin resin sheet according to claim 1 .

A diaper according to claim 3 is composed of a diaper body, a long waterproof film covering the outer surface of the diaper body, and an absorbent body interposed between the diaper body and the waterproof film. A plurality of diaper shape-retaining materials according to claim 1 or 2 are arranged substantially in parallel along the direction.

The diaper according to claim 4 comprises a diaper main body, a long waterproof film covering the outer surface of the diaper main body, and an absorbent body interposed between the diaper main body and the waterproof film. The shape-retaining material for diapers according to claim 1 or 2 is arranged so as to intersect at least two in a X shape.

Hereinafter, the present invention will be described in detail.
The shape-retaining material for diapers of the present invention comprises a stretched olefin resin sheet having a tensile modulus of 10 GPa or more and a stretch ratio of 13 to 40 times . If the tensile modulus is too low, it may not be possible to prevent the absorbent body from sagging or excrement leakage when used as a shape retaining material for diapers. The upper limit of the tensile elastic modulus is not particularly recognized. However, if it exceeds 50 GPa, it is necessary to be careful because the rigidity of the sheet becomes excessively high and the wearing feeling tends to deteriorate and cracks and the like tend to occur.

  When the resin sheet becomes thin, the strength decreases, and when the resin sheet becomes thick, the resin sheet tends to crack. Therefore, the thickness is generally 0.03 to 1.0 mm, and preferably 0.05 to 0.5 mm.

The olefin-based resin is stretched to obtain a sheet having a high elastic modulus and can prevent problems such as sagging of the absorber. In addition, it is preferable in that the environmental load at the time of disposal is small and harmful substances are hardly generated.

The stretched olefin-based resin sheet has shape retainability which means that when the sheet shape is changed, for example, the sheet is bent, the shape is retained . If the stretch ratio of the stretched olefin-based resin sheet is too low, the tensile elastic modulus and shape retention are liable to be insufficient, and if it is too high, the sheet is liable to laterally tear, and is 13 to 40 times, preferably 20 to 35. Is double.

  As the olefin-based resin constituting the stretched olefin-based resin sheet, any olefin-based resin having a film forming ability can be used. For example, a high-density polyethylene resin, a medium-density polyethylene resin, a low-density polyethylene resin, a linear low-density Polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-pentene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate copolymer, ethylene-vinyl chloride copolymer, Examples thereof include an ethylene-propylene-butene copolymer, and a high-density polyethylene resin is preferably used.

If the density of the high-density polyethylene resin is small, the tensile elastic modulus and shape retention will not be improved even if it is stretched, so 0.94 g / cm 3 or more is preferable.
In addition, if the weight average molecular weight of the high density polyethylene resin is too small, the tensile elastic modulus and shape retention will not be improved much even if stretched, and if it is too large, it will be difficult to form and stretch the film. 500,000 is preferable, and the melt index (MI) is preferably from 0.1 to 20 and more preferably from 0.2 to 10 because the film formability is excellent.

  In the present invention, the high-density polyethylene may be used alone, but other polyolefins may be mixed in a proportion of 30 parts by weight or less with respect to 100 parts by weight of the high-density polyethylene. Examples of other polyolefins used in combination include low density polyethylene, ethylene-vinyl acetate copolymer, and polyvinyl acetate.

  Further, the high-density polyethylene may be cross-linked. In this case, it is preferable that the gel fraction of the resin sheet obtained is 20% or more.

  As the stretching method of the olefin resin sheet, any conventionally known method may be employed. To stretch the olefin resin sheet to a high degree of 13 to 40 times, the olefin resin sheet is rolled and then stretched or stretched a plurality of times. A method of repeated multistage stretching is preferred.

  The rolling is a method in which an olefin-based resin sheet is supplied to a pair of rolls rotating in opposite directions and pressed to reduce the thickness of the sheet and extend, and the rolled sheet differs from the stretched sheet in that it is an olefin-based sheet. Since the resin is dense without being oriented, it is highly stretchable.

  The rolling temperature cannot be uniformly rolled when the temperature is low, and melt-cut when it is high. Therefore, the roll temperature during rolling is preferably in the range of "melting point-40 ° C" to the melting point of the olefin resin of the olefin resin sheet to be rolled. More preferably, it is “melting point−30 ° C.” to “melting point−5 ° C.” of the olefin resin.

  In the present invention, the melting point refers to the maximum point of the endothermic peak that accompanies melting of the crystal, which is recognized when thermal analysis is performed with a differential scanning calorimeter (DSC).

  If the rolling ratio is small, the subsequent stretching is burdened, and increasing the rolling ratio makes rolling difficult, so 4 to 10 times is preferable. In the present invention, the rolling ratio and the stretching ratio are values obtained by dividing the cross-sectional area of the sheet before rolling or stretching by the cross-sectional area of the sheet after rolling or stretching.

  The stretching may be any conventionally known method, and examples thereof include a method of stretching while heating with a heater or hot air by a roll stretching method or a zone stretching method.

  The stretching temperature cannot be uniformly stretched when the temperature is lowered, and the sheet melts and cuts when the temperature is increased. Therefore, the range of “melting point−60 ° C.” to the melting point of the olefin resin of the stretched olefin resin sheet is preferable, and more preferably, the olefin It is “melting point−50 ° C.” to “melting point−5 ° C.” of the base resin.

  The stretching ratio after rolling may be determined so that the entire stretching ratio is within this range in consideration of the rolling ratio in order to make the entire stretching ratio 13 to 40 times. If the stretching is small, the mechanical strength is not improved, so it is preferably 2 times or more, more preferably 3 times or more. In addition, the whole draw ratio is a numerical value obtained by multiplying the draw ratio after rolling and the draw ratio after rolling.

  In the present invention, a laminated sheet in which a thermoplastic resin film is laminated on at least one surface of the resin sheet may be used. Lamination of the thermoplastic resin film makes it easy to prevent cracking of the resin sheet, and improves heat-fusibility when laminating these sheets on other materials or laminating sheets. can do.

  Since the thermoplastic resin used for the thermoplastic resin film is preferably one that is firmly bonded to the stretched olefin resin sheet, the above-mentioned olefin resins can be suitably used.

  When the thermoplastic resin has a melting point lower than the melting point of the olefin resin constituting the resin sheet and can be adhered to the olefin resin, for example, the thermoplastic resin film by an adhesive means such as heat fusion Is preferable in that the stretched olefin-based resin sheet can be bonded without substantially heat shrinking. More preferably, the thermoplastic resin has a melting point 5 to 50 ° C. lower than the melting point of the olefin resin.

  Therefore, for example, when the olefin resin is a high density polyethylene resin, the thermoplastic resin is preferably a linear low density polyethylene resin or a low density polyethylene resin.

  Although it does not specifically limit as thickness of the said thermoplastic resin film, Since the feeling of wearing of the diaper obtained will become easy to fall when it is too thick, generally it is 0.01-0.3 mm, Preferably it is 0.02-0. 1 mm.

  In the shape-retaining material for diapers of the present invention, the thermoplastic resin film may be laminated on one side of the resin sheet or may be laminated on both sides. Further, the shape retaining material for diapers may have a multilayer structure in which a plurality of the thermoplastic films and resin sheets are used, for example, alternately laminated.

  As a diaper using the shape retaining material for diapers of the present invention, for example, as illustrated in FIG. 1, a long waterproof film 2 that covers the outer surface of the diaper main body 51, a diaper main body 51, and a waterproof film 2. A diaper shape-retaining material 1 cut into two elongated strips along the longitudinal direction of the waterproof film 2 of a tape-type disposable paper diaper 5 comprising an absorbent body 3 interposed therebetween is a waterproof film 2. And those which are heat-sealed substantially in parallel with each other.

  The part using the shape-retaining material 1 is not particularly limited as long as it is a part that can prevent the sag of the absorbent body. For example, as shown in FIG. Alternatively, it may be arranged in a U shape as shown in FIG.

  Further, the shape retaining material 1 for diapers is used by processing the laminated sheet into an appropriate shape according to the shape of the diaper, and may be, for example, an elongated strip as described above. It may be a curvilinear strip or may be cut into an appropriate shape such as a wide plate. Moreover, you may use together with other elastic materials, such as a rubber string, as needed.

According to the shape-retaining material for diapers of the present invention, when the tensile elastic modulus is 10 GPa or more and the stretched olefin resin sheet has a stretch ratio of 13 to 40 times, and the sheet shape is changed, for example, the sheet is bent It has a shape-retaining property that means that it has a plastic deformability that keeps its shape, so that the tensile modulus is extremely high, the shape-retaining property is excellent, and it is used for diapers. It has an excellent wearing feeling, prevents the absorbent body from sagging due to the weight of excrement such as urine and feces, prevents leakage of excrement, and has low environmental impact during disposal and is easy to incinerate and recycle A shape retaining material for diapers can be provided.

  When the shape-retaining material for diapers of the present invention is a laminated sheet in which a thermoplastic resin film is laminated on at least one side of the resin sheet, the heat-fusibility when the sheets are laminated is improved. Can do.

  The diaper of the present invention comprises a diaper main body, a long waterproof film covering the outer surface of the diaper main body, and an absorbent body interposed between the diaper main body and the waterproof film, and in the longitudinal direction of the waterproof film. A plurality of the diaper shape-retaining materials are disposed substantially parallel to each other, or at least two of the diaper shape-retaining materials are disposed so as to intersect in the X shape on the waterproof film. The diaper which exhibits the same effect can be provided.

The present invention will be specifically described below by showing examples and comparative examples.
In addition, this invention is not limited only to the following Example.
(Example 1)
A polyethylene film (unstretched, thickness 30 μm) as a thermoplastic resin film is melted on one side of a polyethylene stretched sheet (elastic modulus 25.5 GPa) having a stretch ratio of 25 times and a thickness of 200 μm obtained by rolling and stretching. The obtained stretched polyethylene composite sheet (hereinafter also simply referred to as “composite sheet”) was cut into a strip having a width of 4 mm and a length of 900 mm to obtain a shape retaining material for diapers.

  As shown in FIG. 1, a diaper main body 51, a long waterproof film 2 (made of polyethylene) that covers the outer surface of the diaper main body 51, and an absorbent body 3 interposed between the diaper main body 51 and the waterproof film 2. To the waterproof film 2 of the tape-type disposable paper diaper 5 (maximum length of about 900 mm × maximum width of about 700 mm as a whole), the two diaper shape-retaining materials 1 obtained as described above are used as the shape-retaining material 1. A tape-type disposable paper diaper 5 with a shape-retaining material was obtained by heat-sealing so that the surface on which the thermoplastic resin film was laminated was in contact. At this time, the two shape retaining materials 1 were heat-sealed at an interval of about 80 mm so as to be substantially parallel to each other along the longitudinal direction of the waterproof film 2. During heat sealing, heating was performed only from the waterproof film 2 side so that the mechanical properties of the shape-retaining material 1 hardly changed.

(Example 2)
Instead of arranging the shape-retaining materials 1 in parallel, as shown in FIG. 2, the same procedure as in Example 1 was performed except that the two shape-retaining materials 1 were arranged by heat-sealing in an X shape. Thus, a tape-type disposable paper diaper 5 with a shape-retaining material was obtained.

(Example 3)
A polyethylene film (unstretched, thickness 30 μm) as a thermoplastic resin film is melted on one side of a polyethylene stretched sheet (elastic modulus 25.5 GPa) having a stretch ratio of 25 times and a thickness of 200 μm obtained by rolling and stretching. The composite sheet thus obtained was cut out into a strip having a width of 4 mm and a length of 900 mm to obtain a shape retaining material for diapers.

  The two shape-retaining materials obtained as described above are spaced at intervals of about 80 mm so as to be substantially parallel to each other along the longitudinal direction of one polyethylene film (thickness 30 μm, width 100 mm, length 900 mm). The shape-retaining material 1 was heat-sealed so that the surface on which the thermoplastic resin film was laminated was in contact. During heat sealing, heating was performed only from the polyethylene film side so that the mechanical properties of the shape-retaining material hardly changed.

  As shown in FIG. 1, a diaper main body 51, a long waterproof film 2 (made of polyethylene) that covers the outer surface of the diaper main body 51, and an absorbent body 3 interposed between the diaper main body 51 and the waterproof film 2. A polyethylene film in which the two shape-retaining materials 1 are disposed on a waterproof film 2 of a tape-type disposable paper diaper 5 (maximum length of about 900 mm × maximum width of about 700 mm) is heat-melted. By wearing, a tape-type disposable paper diaper 5 with a shape-retaining material was obtained. At the time of heat-sealing, only the rectangular portion having a width of about 4 mm inside the end portion of the polyethylene film was heat-sealed.

(Comparative Example 1)
A disposable paper diaper 5 was obtained in the same manner as in Example 1 except that the shape retaining material 1 for diapers was not used.

(Comparative Example 2)
A tape-type disposable paper diaper 5 in the same manner as in Example 1 except that an elastic elastic member made of a polyurethane elastic film (thickness 40 μm) is used instead of the shape retaining material 1 and the waterproof film 2 is adhered with a hot melt adhesive. Got.

(Comparative Example 3)
A tape-type disposable paper diaper is used in the same manner as in Example 2 except that an elastic elastic member made of a polyurethane elastic film (thickness: 40 μm) is used in place of the shape retaining material 1, and the waterproof film 2 is bonded with a hot melt adhesive. 5 was obtained.

(Evaluation)
The following evaluation was performed about the tape type disposable diaper of the said Example and comparative example. The evaluation results are shown in Table 1.
(Absorber drop test)
Set the tape-type disposable diaper in the wearing state and add 400 ml of simulated urine (tea with about 0.9% saline) to the absorbent body with the waist height fixed. The position of the lowermost part of the absorber after the lapse of time was measured, and the amount of decrease was determined with the position of the lowermost part of the absorbent body before the pseudo-urine addition being taken as 0 point.

  As is apparent from Table 1, the shape retaining material and diaper for the diaper of the present invention have excellent shape retention despite the fact that a polyolefin resin having a low environmental load is used as the shape retaining material. It has been found that the absorber can be prevented from sagging due to urination or defecation, and the leakage of excreta can be prevented.

It is a schematic diagram which shows an example of the diaper using the shape-retaining material for diapers of this invention. It is a schematic diagram which shows another example of the diaper using the shape-retaining material for diapers of this invention. It is a schematic diagram which shows another example of the diaper using the shape-retaining material for diapers of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shape retention material for diapers 2 Waterproof film 3 Absorber 4 Tape 5 Tape type disposable paper diaper 51 Diaper body

Claims (4)

A stretched olefin resin sheet having a tensile modulus of 10 GPa or more and a stretch ratio of 13 to 40 times, and has a plastic deformability that maintains the shape when the sheet shape is changed, such as by bending the sheet. A shape-retaining material for diapers characterized by having shape retention. A shape-retaining material for diapers comprising a laminated sheet in which a thermoplastic resin film is laminated on at least one surface of the stretched olefin-based resin sheet according to claim 1. A diaper main body, a long waterproof film covering the outer surface of the diaper main body, and an absorbent body interposed between the diaper main body and the waterproof film, and along the longitudinal direction of the waterproof film. Alternatively, a plurality of shape-retaining materials for diapers described in 2 are arranged substantially in parallel. A diaper main body, a long waterproof film covering an outer surface of the diaper main body, and an absorbent body interposed between the diaper main body and the waterproof film, and the diaper according to claim 1 or 2 on the waterproof film. A diaper characterized in that at least two shape-retaining materials are arranged so as to intersect in an X shape.

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