JP3034094B2 - Adhesive tape base material for diaper fastening and adhesive tape for diaper fastening - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning adhesive tape base material and an adhesive tape using the base material, and is particularly useful as a medical hygiene material such as a diaper fastening tape.

[0002]

2. Description of the Related Art A fastening tape such as a disposable diaper is required to be a soft base material that is gentle on the skin. Such a soft adhesive tape is a soft and cushioning foam made of rubber and / or synthetic resin. An adhesive tape made of a material is known.

[0003] Such an adhesive tape is usually supplied in a form in which a long tape is wound into a roll, so that the tape can be satisfactorily unwound from the roll when processing as a diaper tape or the like. Thus, the pressure-sensitive adhesive layer provided on one side of the substrate and the back surface of the substrate need to be peelable between the winding layers. In general, in order to enable such rewinding, a release agent such as a silicone-based or long-chain alkyl-based release agent is applied to the back surface of the base material, or between the adhesive layer and the back surface of the base material. A separator such as release paper is interposed.

[0004]

However, the above-mentioned base material for an adhesive tape comprising the rubber and / or synthetic resin foam base material has a large number of pores formed on the surface thereof due to the gas decomposition action of the organic foaming agent. Since it is a closed or simultaneous cellular structure, it is difficult to form a uniform release agent layer on the surface because the release agent is absorbed in the pores even if the release agent is applied to the surface. It is. For this reason, in the type in which the release treatment agent is applied, it is difficult to obtain good rewindability from a roll. On the other hand, if a separator such as a release paper is interposed between the pressure-sensitive adhesive layer and the back surface of the base material, the cost is high, and there is a problem such as disposal of the separator. Furthermore, since the above-mentioned foamed base material is a thick product having a thickness of about 2 to 10 mm, it is bulky for medical uses such as fastening diapers and is not practical.

[0005]

According to the present invention, as a result of intensive studies on the above-mentioned problems, the pressure-sensitive adhesive tape base material and the pressure-sensitive adhesive tape obtained by using a specific heat-expanding agent for forming the base material have the above problems. The inventors have found that all points can be solved and completed the present invention.

That is, the base material for the pressure-sensitive adhesive tape of the present invention is formed into a thin layer of a composition obtained by mixing a microcapsule-type heat-expanding agent in a rubber and / or synthetic resin base, and heat-expands the composition. It is a configuration comprising, preferably a reinforcing layer provided on one side of this substrate, as the pressure-sensitive adhesive tape of the present invention, a configuration in which a pressure-sensitive adhesive layer is provided on at least one side of the substrate for the pressure-sensitive adhesive tape Is done.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 1 denotes a pressure-sensitive adhesive tape substrate of the present invention, which is a thin layer of a rubber and / or synthetic resin composition obtained by mixing a microcapsule-type heat-expanding agent in a rubber and / or synthetic resin base. It is formed and then heat-expanded (11 in the figure shows the expanded portion of the heat-expanding agent). Reference numeral 2 denotes an adhesive layer provided on one side of the substrate 1.

[0008] As the rubber and / or synthetic resin base component, a polymer component having sufficient flexibility and elasticity when formed into a thin layer, for example, chloroprene rubber, ethylene propylene rubber, ABA type or AB type block Copolymer (A is a thermoplastic block, B is a rubber block, for example, styrene-isoprene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer obtained by adding hydrogen to styrene,
Styrene-ethylene-butadiene-styrene copolymer,
Rubbers such as thermoplastic rubbers such as styrene-butadiene copolymer, etc .;
Synthetic resins such as a thermoplastic resin such as an ethylene-vinyl acetate copolymer can be suitably used, and a blend thereof is also included.

The microcapsule type heat-expanding agent mixed in the base is heated to 90 to 150 ° C. to form
A gaseous substance such as butane gas or propane gas which expands 70 times, preferably 25 to 45 times, is encapsulated in a shell made of a thermoplastic resin such as acrylonitrile copolymer, vinylidene chloride-methyl methacrylate copolymer. It can be suitably used and expands by heating or bursts after expansion. Such a heat expanding agent usually has a particle size of 1 to 50 μm.
m, preferably 10 to 20 μm. Specific examples include commercially available products such as “Matsumoto Microsphere” manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.

The amount of the heat-expanding agent can be appropriately determined in consideration of the type and application of the heat-expanding agent, and is usually 0.1 to 30 parts by weight based on 100 parts by weight of the polymer.
It is blended in the range of parts by weight. Heat expansion temperature is usually 90 ~
The temperature is preferably set to 140 ° C., and the expansion ratio is usually about 1.5 to 10 times.

A composition obtained by mixing a microcapsule-type heat-expanding agent in a rubber and / or synthetic resin base may contain a softening agent, if necessary, in order to further soften the obtained base material. A small amount of tackifying resin can be added to impart light tackiness. Further, an antioxidant or the like may be added for improving the weather resistance and heat resistance of the obtained base material.

In order to prepare the pressure-sensitive adhesive tape base 1 from the rubber and / or synthetic resin composition, first, the above-mentioned heat-expanding agent is added to a polymer solution obtained by dissolving a rubber and / or synthetic resin base in a solvent. After mixing, this composition solution is applied and formed into a thin layer state on an easily peelable support, for example, so that the thickness in the naturally dried state is about 5 to 100 μm. Then, the composition liquid thus formed in a thin layer state is heated in a drier having a temperature zone of 90 to 140 ° C. for about 0.1 to 60 minutes, so that the heating expanding agent does not burst and pores are not formed on the surface. To give a base material 1 for an adhesive tape having a thickness of about 20 to 400 μm.

While a large number of closed-cell inflatable portions are formed in the inside of the obtained base material 1, the surface 10 has a gentle uneven surface due to the expansion of the heating expander. On the other hand, when the easily peelable support is separated from the substrate, the surface of the support is smooth, so that the other surface of the substrate 1 is formed smoothly.

The pressure-sensitive adhesive layer 2 is formed on the surface of the base material 1 for the pressure-sensitive adhesive tape opposite to the surface 10 (the smooth surface side adhered to the easily peelable support) by a rubber-based or acrylic-based pressure-sensitive adhesive. 4 ~
It is provided by coating to a thickness of about 1000 μm.

The surface of the pressure-sensitive adhesive tape thus constructed is coated with a release agent such as a silicone-based or long-chain alkyl-based product to produce a product, but the surface 10 is smooth without holes. Since an uneven surface skin is formed, the release agent can be applied to a uniform thickness.

FIG. 2 shows an example in which a reinforcing layer 3 is provided on one side of a base material 1 for an adhesive tape. Usually, the base material for an adhesive tape obtained as described above has a 50% tensile stress of 0.5.
It is an easily stretchable base material of about 10 kg / cm ² (tensile speed 30 cm / min). Therefore, in applications requiring a predetermined waist and tensile strength, such as for diapers, it is desirable to provide a reinforcing layer as shown in FIG. 2 to suppress the elongation of the adhesive tape.

A reinforcing layer 3 is provided on one side of the base material 1 for an adhesive tape.
May be formed by laminating a reinforcing film constituting the layer 3 on one surface of the base material 1 for an adhesive tape prepared in advance, but mixing a heating expander as described above on the surface of the reinforcing film. The rubber and / or synthetic resin composition may be formed in a thin layer and expanded by heating to be integrally manufactured.

The reinforcing film is made of, for example, a polyester film such as polyethylene terephthalate, a polypropylene film, or polypropylene and one or more of polyethylene, ethylene-vinyl acetate copolymer and ethylene-propylene copolymer. Plastic film with a thickness of 4-20
Approximately 0 μm, the compressive strength in the width direction of the ring crush method is in the range of 10 to 1500 g (film width 25 mm, roll diameter
A flexible film having a thickness of 20 mm) is preferable because a predetermined rigidity and strength can be obtained by suppressing the elongation of the base material without reducing the softness of the base material.

If necessary, an undercoating agent containing an isocyanate-based crosslinking agent or the like is applied to the film surface in advance,
The adhesion to the substrate 1 can be increased.

FIG. 3 shows a specific example of the present invention which is suitably used for a fastening portion of a diaper, such as a diaper fastener tape. Such a pressure-sensitive adhesive tape is prepared by preparing a long pressure-sensitive adhesive tape base material 1 and coating (10a, 10b) a release treatment agent on both sides thereof in such a manner as to be arranged in reverse in half in the width direction. Attach the reinforcing films 30a and 30b to the other half, and
It is made by applying the adhesive layers 20a, 20b on a, 30b. When this is folded in the width direction, the release agent 10a and the pressure-sensitive adhesive layer 20a come into contact with each other. When the tape is wound in the longitudinal direction as shown in FIG. 4, the surface of the release agent 10b protects the pressure-sensitive adhesive layer 20b. . When using this as a diaper fastener tape, cut it to a certain length in the longitudinal direction and cut the outer adhesive layer.
20b is fixed to the back of the diaper, for example, and the other adhesive layer 20a is fixed to the front of the diaper.

[0017]

According to the present invention, the release treatment agent is applied with a uniform thickness because it is constituted as described above and is composed of a base material covered with a smooth uneven surface skin having no holes. It is possible to provide a soft adhesive tape base material that is thin and skin-friendly. In addition, the base material for an adhesive tape provided with a reinforcing layer on one side of the base material can suppress the elongation of the base material to obtain a predetermined stiffness and strength, and provide an adhesive layer on one side thereof to provide an adhesive layer. The tape is characterized in that it is soft and has a sufficient cushioning property, does not require a separator, and provides good rewinding properties. In particular, when this is used for medical hygiene such as fastening of a diaper to be touched by human skin or fixing of a napkin, a thin and soft skin-friendly touch is obtained, which is preferable.

The effects of the present invention will be described in more detail with reference to the following examples.

Example 1 Styrene-butadiene-styrene copolymer
A composition solution obtained by mixing 10 parts of "Matsumoto Microsphere F-301D" as a heat-expanding agent in a solution obtained by dissolving 100 parts by weight of toluene in toluene so as to have a solid content of 40% was added to a solution of 25 μm.
m Polyester film with 50mm width and thickness (reinforced film)
Apply on the top so that the thickness after air drying is 45 μm.
By heating and expanding at 0 ° C. for 1 minute, a base material for a pressure-sensitive adhesive tape with a reinforcing layer having a total thickness of 200 μm was prepared. The compressive strength in the width direction described in the text of the polyester film is 120 g. The surface of this substrate is a smooth uneven surface with no holes, and an addition type silicone (“X-62-2378” manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to this surface and heated at 130 ° C. for 1 minute. Thus, a release agent layer having a uniform thickness of 0.5 g / m ² was formed. Then, on the opposite side of the polyester film, 50 μm
A thick rubber-based pressure-sensitive adhesive layer was applied and formed. This was manufactured to a length of 100 m and wound up in a roll to obtain a sample.

[0019]

Example 2 A sample was prepared in the same manner and under the same conditions as in Example 1 except that a styrene-ethylene-butadiene-styrene copolymer was used in place of the styrene-butadiene-styrene copolymer as a base component. .

[0020]

Comparative Example 1 Foamed with a gas decomposition type organic foaming agent 2
A release agent layer was formed on one side of the urethane foam sheet having a thickness of mm (expansion ratio about 30 times) in the same manner as in Example 1, and an adhesive layer was formed on the other side in the same manner as in Example 1. The sample was taken up in a roll.

[0021]

Comparative Example 2 A sample was prepared in the same manner as in Comparative Example 1, except that a polyethylene foam sheet having a thickness of 2 mm (expansion ratio: about 10 times) was used instead of the urethane foam sheet.

Each of the roll-shaped samples having a length of 100 m prepared in Examples 1 and 2 and Comparative Examples 1 and 2 was heated at 23 ° C. × 1 day at 40 ° C.
The tape was stored for 1 day, and the rewinding force of the tape was measured (rewinding speed was 10 m / min). Table 1 shows the results.

[0023]

[Table 1]

The tape obtained in Examples 1 and 2 was cut into a size of 2.5 cm × 7.0 cm and used as a fastening part (fastener tape) for a diaper. This was used to monitor 50 mothers with infants. The person who answered that it was soft was a conventional polypropylene tape (100μm thick)
As a result, the result was as high as 45 in both Example 1 and Example 2.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an example of the present invention.

FIG. 2 is an explanatory sectional view showing another example of the present invention.

FIG. 3 is an explanatory sectional view showing another example of the present invention.

FIG. 4 is a partially sectional explanatory view showing another example of the present invention.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C09J 7/02 B32B 7/10 C08J 5/18

Claims (4)

(57) [Claims] 1. A diaper fastening adhesive obtained by forming a composition obtained by mixing a microcapsule-type heat-expanding agent in a rubber and / or synthetic resin base into a thin layer and heat-expanding the composition.
Tape base material. 2. A pressure-sensitive adhesive tape base material for fastening a diaper , wherein the base material according to claim 1 is provided with a reinforcing layer on one surface. 3. A pressure-sensitive adhesive tape for fastening a diaper , comprising a pressure-sensitive adhesive layer provided on at least one side of the substrate according to claim 1 . 4. A pressure-sensitive adhesive tape for fastening a diaper , comprising a pressure-sensitive adhesive layer provided on at least one side of the substrate according to claim 2 .