JPS63112704A - Tape for diaper - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is made of a blended polymer containing polypropylene, which has texture, firmness, and strength suitable for base materials such as adhesive tapes and release tapes in disposable diapers, and has a moderate The present invention relates to a diaper tape that has high heat resistance and excellent workability.

Conventional technology and problems Disposable diapers have been popular for a long time due to their convenience (Japanese Patent Publication No. 52-34978; type using knotting tape without release paper, Utility Model Application No. 55-75)
Publication No. 608; a type using a knotting tape in which three tapes are overlapped and re-peelable, etc.).

The base material of the adhesive tape used in disposable diapers should have a suitable texture in terms of skin contact, a suitable stiffness (rigidity) in terms of ease of handling such as wearability, and resistance to breakage etc. In addition to requiring moderate strength,
Safety is required to prevent redness, rashes, or burns on infants and young children. In addition, ease of cutting and heat resistance are also desired from the point of view of processing into adhesive tapes, release tapes, and the like.

Conventionally, the base material is made of nonwoven fabric. Things were known. However, since the manufacturing process of nonwoven fabrics is complicated and requires a lot of labor, there are disadvantages in that nonwoven fabrics are disposable and can be seen as being of excessive quality.

Perhaps in consideration of this difficulty, tapes made of films made solely of polypropylene have been proposed. However, this diaper has a problem in that it has a poor texture and is unsatisfactory, especially since it is a diaper worn by infants and young children.

Means for Solving the Problems The present invention aims to overcome the above-mentioned problems of the prior art while taking into account that the application is diapers. It is characterized by being made of a blended polymer with a special polymer and having a polypropylene content within a special range, and being excellent in mass production and processability.

That is, the present invention provides an ethylene-vinyl acetate copolymer,
To provide a tape for diapers, which is made of a blend of one or more polyethylene or ethylene-propylene copolymers and polypropylene, and has a polypropylene content of 5 to 75% by weight. It is.

The tape of the present invention is made of a film made of a blend polymer of polypropylene and one or more of ethylene-vinyl acetate copolymer, polyethylene or ethylene-propylene copolymer.

There are no particular limitations on the component polymers used. In general, compatibility, uniformity of flow, in the case of blends, especially blends of polypropylene and polyethylene;
Alternatively, from the viewpoint of the strength of the resulting film, a blend of polymers with similar melt indexes (M I ) is preferred. However, the strength of the obtained film does not decrease significantly due to the difference in Ml. In addition, as an ethylene-vinyl acetate copolymer, its vinyl acetate content is 3 to 15% by weight.
Those are usually preferably used. Furthermore, the blend is usually processed into a film by T-die extrusion at a temperature of 200 to 250°C, but the higher the temperature, the better the moldability and surface appearance of the resulting film. It is generally desirable to blend to a composition that allows high temperature molding.

The tape of the invention consists of a film containing 5 to 75% by weight of polypropylene. The higher the polypropylene content, the better the stiffness, strength, and heat resistance. Therefore, the amount of polypropylene to be blended is appropriately determined mainly from the viewpoint of the texture of the film or tape obtained and the relationship with other blend components.

The tape of the present invention is an adhesive tape provided with a pressure-sensitive adhesive layer on one or both sides, an adhesive tape provided with a releasable treated layer on one side, or an adhesive tape provided with a releasable treated layer on one or both sides. It is preferably used as a base material in release tapes, etc. In other words, for example, but not limited to, tying tape, fastener tape, center tape (for re-peeling), release tape (for protecting the glue surface), etc. in disposable diapers in the form of adhesive tapes, release tapes, etc. It is preferably used as

Effects of the Invention According to the tape of the present invention, it is possible to obtain a diaper that is excellent in handling when changing, etc., based on its waist, strength, and texture, and also has excellent compatibility with the skin.

In addition, it is excellent in mass production and, based on its heat resistance, is excellent in processability when producing adhesive tapes, release tapes, etc., for example.

Examples Example 1 30 parts (by weight, the same applies below) of polypropylene with an Ml of 9.0 g/10 min at 230°C and an ethylene-vinyl acetate copolymer (with an MI of 0.5 g/10 min at 190°C) 70 parts (vinyl acetate content: 3% by weight) were mixed in a Henschel mixer for 10 minutes, and then extruded with a T-die extruder at a cylinder temperature of 230°C to a thickness of 200p.
A film of m was obtained.

Example 2 10 parts of polypropylene with an Ml of 1.5 g/10 min at 230°C and 1.5 g/10 min of Ml at 190°C.
A film was obtained according to Example 1, except that 90 parts of 10-minute low-density polyethylene was used.

Example 3 A film was prepared according to Example 1, except that 15 parts of polypropylene with an Ml of 20 g/10 min at 230°C and 85 parts of low-pressure low-density polyethylene with an MI of 7.5 g/10 min at 190°C were used. Obtained.

Example 4 15 parts of polypropylene with an MI of 0.5 g/10 min at 230°C and 1.0 g/10 min of MI at 230°C.
15 parts of ethylene-propylene copolymer for 10 minutes;
Ethylene-vinyl acetate copolymer with Ml at 0°C of 1.5 g/10 min (vinyl acetate content 10% by weight)
A film was obtained according to Example 1 except that 70 parts were used.

Comparative Example 1 A film was obtained according to Example 1 except that polypropylene having an Ml of 9.0 g/10 min at 230° C. was used alone.

Comparative Example 2 Ethylene with Ml of 1.5 g/10 min at 190°C
A film was obtained according to Example 1 except that a vinyl acetate copolymer (vinyl acetate content: 3% by weight) was used alone.

Comparative Example 3 A film was obtained according to Example 1, except that low-density polyethylene having an Ml of 1.5 g/10 min at 190° C. was used alone.

Evaluation Test The tapes obtained by cutting the films obtained in Examples and Comparative Examples were evaluated as follows.

[Strength] TD (Tensile Strength) A tape of two widths of 10 m+a was pulled under conditions of a chuck interval of 20 and a pulling speed of 50/min, and the maximum stress up to breakage was measured.

MD (initial modulus of elasticity): The modulus of elasticity was calculated from the curve at the initial stage of tension based on the stress strain curve in the tensile test.

〔Heat-resistant〕

The tape was placed on a hot plate and the temperature was raised, and the temperature at which the base material melted and began to flow like a droplet was measured.

[Waist 1] A tape with a width of 25 rIrm and a length of 10 cm is placed on a horizontal table with half of its length (5 am) protruding from the table, and the tip of the protruding portion is determined with the protruding portion hanging down. Based on the horizontal table (the distance from the virtual horizontal plane, that is, the sagging distance was measured).

[Feel] The feel of the cut edge of the tape when it came into contact with the skin was evaluated in three levels: hard, good, and soft (too soft).

The results are shown in the table.

From the examples in the table, it can be seen that the tape of the present invention has appropriate strength, stiffness, and texture required for base materials in adhesive tapes for diapers, etc., and also has good heat resistance related to processability. .

Claims (3)

[Claims] 1. One or more types of ethylene-vinyl acetate copolymer, polyethylene or ethylene-propylene copolymer,
1. A tape for diapers, characterized in that the film is made of a blend with polypropylene and has a polypropylene content of 5 to 75% by weight. 2. The diaper tape according to claim 1, which has a pressure-sensitive adhesive layer and is in the form of an adhesive tape. 3. The diaper tape according to claim 1, which has a releasable treated layer.