JPH0257253A - Facing material of sanitary article - Google Patents

Abstract

PURPOSE:To obtain a flexible facing material improved in the absorbability of body fluids, suppressing the back flow of the liquid absorbed with the absorbing material as low as possible and having no feeling of physical disorder at the time of wearing by using a nonwoven fabric constituted of a fiber based on a hydrophobic fiber composed of a thermoplastic polymer. CONSTITUTION:A hydrophobic fiber composed of a thermoplastic polymer constituting a nonwoven fabric A is obtained by spinning at least one kind of a polymer selected, for example, from polyethylene, polypropylene or thermoplastic polyurethane. A nonwoven fabric B is constituted of a hydrophilic fine fiber or a hydropiylic agent coated fine fiber and, when said fiber is prepared by spinning, at least one kind of polymer wherein a hydrophilic substance is preliminarily compounded with a hydrophobic polymer is used. Next, the nonwove fabric or liquid permeable film A and the nonwoven fabric B are laminated while the obtained laminate is subjected to integrating treatment at least partially by heat-treatment, high frequency treatment or ultrasonic treatment to obtain a required laminated sheet like article.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to sanitary napkins, paper diapers, bats for incontinence,
The present invention relates to a facing material for covering absorbent articles that mainly absorb liquid, such as postpartum vats, breast milk vats, and cosmetic puffs.

[Conventional technology]

In recent years, many products have been developed due to the spread of sanitary products for absorbing body fluids. Sanitary products have various performance requirements depending on their use, but the surfaces that come into contact with the skin are particularly sensitive to tactility,
It is strictly evaluated in terms of texture and feel when worn. From this perspective, many proposals have been made for facing materials for conventional sanitary products. In particular, from the viewpoint of texture, many use hydrophobic fibers or a fibrous web made of a mixture of hydrophobic fibers and hydrophilic fibers as the facing material. For example, a method using an untreated fiber web made from polyolefin*M or polyester fiber is disclosed in JP-A-51-87.
No. 398, JP-A-59-200653, JP-A-61-60702, JP-A-6115693, and JP-A-62-27161 disclose compositions for improving surface texture and liquid absorbency. In JP-A-56-1574, a plurality of N4 layers of different fibers are laminated with different sacrificial ratios of rayon and thermoplastic fibers.
No. 4, JP-A No. 56-23949, or Utility Model Application No. 57-2, in which heat-adhesive fibers and hydrophobic fibers and/or hydrophilic fibers are mixed and laminated with different mixing ratios are disclosed.
6227, JP-A-57-61702, and JP-U-63-27406 disclose that the state of the laminated fiber web is changed, with a hydrophilic nonwoven fabric on the surface layer side and a hydrophobic nonwoven fabric on the absorbent side. The laminated structure with the material side was published in 1983.
-31659 Publication, JP-A No. 62-261363 K, the surface layer is a perforated nonwoven fabric made of fibers mainly composed of hydrophobic fibers, and the inner layer is a non-porous nonwoven fabric made of fibers mainly composed of hydrophilic fibers. A composite surface material was published in JP-A-62-170.
No. 565 discloses that the fiber web consists of an upper layer and a lower layer made of a fiber web mainly composed of hydrophobic fibers, the upper layer is formed with high density fibers having a thread fineness, the upper and lower layers are overlapped, and a binder is attached. An exterior nonwoven fabric is proposed in Japanese Patent Publication No. 17942/1983.

Furthermore, in order to improve liquid permeability by applying a treatment agent to a nonwoven fabric for facing, a nonwoven fabric obtained by treating a polypropylene fiber nonwoven fabric with a mixture of lanolin, an emulsifier, and a surfactant is disclosed in Japanese Patent Application Laid-Open No. 62-90371. 9 non-woven fabrics using polyester fibers whose surface has been made hydrophilic with polyester oligomers containing polyester groups were published in JP-A-62-19165.
It is disclosed in Japanese Patent Publication No. 62-2532 and Japanese Patent Publication No. 63-140 that a nonwoven fabric treated with a treatment agent containing potassium salt of linear alkyl phosphate having 12 to 22 carbon atoms is used.
This is proposed in Publication No. 81.

[Problem to be solved by the invention]

The conventional 7 Acing material was designed to be a non-woven fabric with less fuzz to improve the feel of the fabric, and prioritized smoothing, which resulted in loss of flexibility and poor wearing comfort.

However, if the surface that comes into contact with the skin is hydrophilic, once absorbed, bodily fluids will flow back, making it uncomfortable to wear.

On the other hand, it is possible to manufacture a thin fiber web such as a facing material into a laminated non-woven fabric with at least two layers, especially when the fibers used are fine fibers or specially treated fibers. Manufacturing control is not easy in order to efficiently obtain a homogeneous laminated nonwoven fabric.

The present invention provides a laminated nonwoven fabric with good homogeneity, which is a facing material that has good absorbency for body fluids, suppresses backflow of liquid absorbed into the absorbent material as much as possible, is flexible, and does not feel uncomfortable when worn. There is K.

[Means to solve the problem]

The present invention uses a nonwoven fabric mainly composed of hydrophobic fibers made of a thermoplastic polymer or a hydrophobic liquid-permeable film (A) made of a thermoplastic polymer as a surface layer, and a hydrophilic film made of a thermoplastic polymer. A laminated sheet-like product in which a nonwoven fabric (B) composed of fine fibers and/or hydrophilic agent-added fine fibers is laminated as an absorbent side, and at least a part of the nonwoven fabric (B) is integrated, the laminated sheet-like product having physiological saline. This is a facing material for sanitary products, characterized in that the water absorption time is 2 seconds or less.

Further, the present invention produces a nonwoven fabric made of fibers mainly composed of hydrophobic fibers made of a thermoplastic polymer, or a hydrophobic liquid-permeable film (A) made of a thermoplastic polymer. Hydrophilic polymers and/or hydrophobic polymers are melt extruded, spun into a fine fiber stream by high temperature and high pressure gas flow, collected in a collection body to form a fibrous web, and heated or non-heat pressed as required. When making a nonwoven fabric (B), a fiber-forming polymer, a hydrophilic agent-added fine fiber or/and a hydrophilic polymer spun by adding a hydrophilic substance or a water-absorbing substance in a melt system or a spinning system. A hydrophilic nonwoven fabric (B) made from a fiber web of spun hydrophilic fine fibers, a nonwoven fabric or a liquid-permeable film (
A) and a hydrophilic nonwoven fabric (B) are laminated, or a hydrophilizing agent-added fine fiber and/or a hydrophilic fine fiber are directly spun on the negative side of the nonwoven fabric or liquid-permeable film (A) to form a fibrous web. After the lamination, at least a portion of the laminated sheet is subjected to a process of integration to form a laminated sheet, and the laminated sheet has a degree of hydrophilicity such that the absorption time of 1 wit of physiological saline is 2 seconds or less. This is a method for manufacturing facing materials for sanitary products.

The hydrophobic fibers made of a thermoplastic polymer constituting the nonwoven fabric (A) of the present invention are, for example, polyethylene, polypropylene,
Polyolefins such as ethylene copolymers, nylon-6
, nylon-66, nylon-610, nylon-8,
Selected from polyamides such as nylon-11 and nylon-12, polyesters such as polyethylene terephthalate and ethylene terephthalate copolymers, polybutylene terephthalate and butylene terephthalate copolymers, vinyl chloride copolymers, thermoplastic polyurethanes, etc. It is a fiber obtained by spinning at least one kind of polymer. It also contains a thermal binder fiber containing a heat-fusible component in the hydrophobic fiber made of a thermoplastic polymer.

The thermal binder fiber is a core-sheath type composite fiber with a high melting point polymer as a core component and a low melting point polymer as a sheath component, or a bonded type composite fiber of a high melting point polymer component and a low melting point polymer component, such as polyethylene/polypropylene, Polyethylene/polyethylene terephthalate, polyethylene 2/polyamide, low melting point polyester/high melting point polyester, etc., and single component low melting point polymer fibers such as polyethylene,
These fibers are made of ethylene copolymer, vinyl chloride copolymer, polyester, etc. When hydrophobic fibers and thermal binder fibers are mixed, the amount of thermal binder fibers is preferably 15 to 100% by weight in terms of shape stability, bulkiness, and surface fluffiness of the nonwoven fabric (A). Ke25-1
00! It is within the range of quantity.

The fibers constituting the nonwoven fabric (A) may be filament-like and web-like, but from the standpoint of thinness and homogeneity of fiber accumulation, it is preferable to use short #& fibers wrapped around a card to form a fiber web. web, random web,
A desired thickness and basis weight are obtained as a cross-wrap web, and if necessary, a fiber-entangled nonwoven fabric is formed by a two-dollar punch method or/and a high-pressure fluid jet treatment method, and then heat treatment is applied to at least a portion of the fiber contact area. fuse.

In a fibrous web of hydrophobic fibers made of thermoplastic polymers, at least a portion of the polymers are fused! Heat treatment at −7°C temperature. In addition, in a fibrous web consisting of hydrophobic fibers and thermal binder fibers, at least a portion of the thermal binder fibers is heat-treated at a temperature sufficient for M-wearing and at a temperature that does not melt the other fibers. The temperature is selected within the range of 250°C.The heat-treated fiber web is heated or not heated, and is brought into contact with a calendered surface, pressed if necessary, to smooth the surface without fuzzy fibers, and fill it. Nonwoven fabric (A
). The basis weight of the nonwoven fabric varies depending on the desired sanitary product, but is generally in the range of 5 to 50 f/nI'.

In addition, a hydrophobic liquid-permeable film made of a thermoplastic polymer (A
) is 1, for example, flexible polyethylene, ethylene copolymer, polyvinylidene chloride, vinylidene chloride copolymer, polybutene, butene copolymer, thermoplastic polyurethane, ethylene/vinyl acetate copolymer or saponified product thereof. Liquid-permeable pores are formed in a flexible film obtained by molding a polymer selected from the following, using methods such as high frequency or ultrasonic treatment, hot pressing, electrical discharge machining, needle bunching, and stretching. Another method may be to form foam during film production and destroy the bubbles during lamination to transform them into liquid-permeable pores.

Next, the nonwoven fabric (B) of the present invention is obtained by melt-extruding a hydrophilic polymer or /' which is a thermoplastic polymer and a hydrophobic polymer, and spinning it into fine fibers that are not fiber bundles by spraying a high-temperature and high-pressure gas stream. A fibrous web is made by the melt-prone method of accumulating into a web, and is subjected to a press treatment (1.7) under heating or non-heating as required, and at least a portion of the #R fiber contact area is fused to form a non-woven fabric. The nonwoven fabric (B) is composed of hydrophilic aψ fibers or fine fibers to which a hydrophilic agent has been added. The hydrophilic fine fibers are made by spinning a hydrophilic polymer such as volvinyl alcohol, vinyl alcohol copolymer, ethylene vinyl alcohol copolymer, or polyoxyethylene copolyester. The fibers obtained by this process, and the fine fibers to which a hydrophilic agent has been added, are made of hydrophobic polymers, such as polyurethanes such as polyethylene, ethylene copolymers, polypropylene, and polybutylene, and olefin copolymers, nylon-6, nylon-66, and nylon-6. 6101
Polymers selected from polyamides such as nylon-11 and nylon-12, polyesters such as polyethylene terephthalate, ethylene terephthalate copolymers, polybutylene terephthalate, and thermoplastic polyurethanes are spun either singly or in combination. When producing fibers, a hydrophobic polymer melting system or spinning system (e.g., at a spinning nozzle, in a gas stream or a jetted fiber stream, etc.) uses at least one type of polymer in which a hydrophobic polymer is blended with a hydrophilic substance in advance. The fibers are obtained by adding a hydrophilic agent by a method such as adding a hydrophilic substance at any stage of the above process or by treating an integrated fiber web to add a hydrophilic substance.

The hydrophilic substance to be applied to the fibers is, for example, ethylene oxide-added surfactant 1. Nonionic surfactant, polyerylene oxide, polyvinylalcofur, vinyl alcohol copolymer, higher alkyl phosphate ester salt,
Contains substances selected from higher alcohols, ethylene oxide-added phosphate esters, water-absorbing organic polymers such as olefin-unsaturated carboxylic acid copolymer anhydrides, acrylic resins, and fine powder of hygroscopic inorganic materials. Or attach it. Alternatively, a polymer obtained by graft polymerizing hydrophilic groups may be mixed and spun.

The basis weight of the nonwoven fabric (B) varies depending on the desired sanitary product, but is generally in the range of 3 to 200 l/I.

Next, the nonwoven fabric or liquid-permeable film (A) and the nonwoven fabric (
B) is laminated. Nonwoven fabric (A) When K smoothing treatment is applied, the smoothed surface is the front surface, and the nonwoven fabric (B
) are stacked. At least a portion of the laminate is integrated by heat treatment, high frequency treatment, or ultrasonic treatment to form a laminate sheet-like product. As another method, when laminating the nonwoven fabrics (B), it is also possible to apply an adhesive in dots or planes to the laminated surface and laminate and integrate them. In addition, non-woven fabric (
It is also possible to directly accumulate and laminate B) on the nonwoven fabric or liquid-permeable film (A) to integrate at least a portion thereof.

Furthermore, the hydrophilic fine fiber nonwoven fabric of the nonwoven fabric (B) may be obtained by laminating multiple layers of nonwoven fabrics with different degrees of hydrophilicity and integrating at least a portion thereof, for example, a nonwoven fabric with a high degree of hydrophilicity may be laminated on the absorbent body side. This is effective in preventing backflow of sanitary products and thin sanitary products where backflow is a concern.

The laminated sheet-like material of the present invention is prepared using physiological saline solution l at
The degree of hydrophilicity is such that the absorption time is 2 seconds or less. If the absorption time of physiological saline is longer than 2 seconds, the user will feel wet or wet during use, which may cause discomfort.

The hydrophilicity of nonwoven fabrics or laminated sheets was determined using F paper (Product 4 manufactured by Toyo P Paper Co., Ltd.) as a liquid absorber.
5), stack 10 sheets, place the sample to be measured on top of it, drop 1 d of physiological saline, and judge by the travel time required until there are no water droplets on the surface, and the absorption time of physiological saline is short. The shell was evaluated as a fiber with a high degree of hydrophilicity. The nonwoven fabric of the present invention (
B) Alternatively, by using a laminated sheet material that absorbs physiological saline within 2 seconds, it is possible to obtain a product that does not cause discomfort when worn.

The laminated sheet material of the present invention can be used as a facing material for sanitary products,
For example, sanitary napkins, disposable diapers, bats for incontinence,
It is suitable for facings constituting liquid absorbent articles such as postpartum vats, breast milk vats, and cosmetic puffs.

〔Example〕

Embodiments of the present invention will be explained below using specific examples.

In addition, parts and percentages in the examples refer to weight unless otherwise specified.

Example 1 Polyethylene terephthalate fiber 45 with a fineness of 2 denier
%, 55 parts of eccentric conjugate fibers (binder fibers) whose core component is polypropylene and sheath component is high-flow polyethylene were mixed, and a fiber web was made with random univar, after a long time of 13
After heat treatment for 15 seconds in a heating machine at 5°C, the surface was polished to a mirror finish and pressed on nine calendar rolls to make a smooth surface, and most of the areas in contact with the binder fibers were melted and bonded.
5.5f/rr! , thickness 0.2-1m, apparent density 0.
A nonwoven fabric (Al) of 083 r/- was obtained.

Separately, a composition containing 30% ethylene oxide-added surfactant as a hydrophilic agent, 87% high-flow polyethylene, and 10% polypropylene was melted in an extruder, and spun into a fiber stream using a melt-blowing die by heating and high-pressure air flow. The fibers were taken out and collected on a collecting body to obtain a fiber web having a basis weight of 12 f/ni''.

A nonwoven fabric (B1) of fine fibers was obtained from this fibrous web in which a portion of the fiber contact area was fused. The hydrophilicity of this nonwoven fabric was achieved in 0.8 seconds.

Furthermore, a nonionic surfactant was added to the nonwoven fabric (Bl) to obtain a nonwoven fabric (B2) with increased hydrophilicity. The hydrophilicity of this non-woven fabric is 9 seconds or less.

Next, a nonwoven fabric (B1) was laminated on the back side of the nonwoven fabric (Al), and a laminated nonwoven fabric (sample 1) was obtained by integrating the nonwoven fabric (B1) using an ultrasonic treatment method. Similarly, a laminated nonwoven fabric (sample 2) in which the nonwoven fabric (B2) was laminated and integrated with the nonwoven fabric (A1)
), nonwoven fabric (Al), nonwoven fabric (Bt ), and nonwoven fabric (
A laminated nonwoven fabric (sample 3) in which Bx) was laminated and integrated was obtained.

For comparison, in the production of nonwoven fabric (Bl), a composition containing no hydrophilic agent was spun under the same conditions, and the fabric weight was 12.
．． A 1f/♂ nonwoven fabric (Bo) was obtained. The hydrophilicity of this nonwoven fabric was achieved in 10 seconds or more. This nonwoven fabric (Bo) was integrated with a nonwoven fabric (AI) to obtain a laminated nonwoven fabric (sample 4).

We evaluated the saline absorption time of each laminated nonwoven fabric, covered it with a liquid absorbent substance to make a sanitary bat, and evaluated the 7 dressing materials based on the liquid absorption and diffusion properties and the feeling of wearing when actually worn.
The results are shown in Table 1.

Table 1 However, ◎ Best, ○ Good, × Bad In other words, the facing material of the present invention had high flexibility, good texture, and fast liquid absorption rate.

Example 2 A composition consisting of 30% hydrophilized polyethylene, 60% high-flow polyethylene, and 10% polypropylene was spun using the melt-bun method under the same conditions as in Example 1, and the fabric weight was 15.
r/n? A nonwoven fabric (Ba) was obtained.

In addition, a composition consisting of 70% high-flow polyethylene, 27% polyvinyl arsil for melt molding, and 3% polyoxyethylene was spun using the melt-blanking method in the same manner as in Example 1, and the fabric weight was 15.3 f/i. A nonwoven fabric (B4) was obtained. The hydrophilicity of the nonwoven fabric (B3) was 1.4 seconds;
4) Hydrophilicity was 0.8 seconds.

Hole-open polyethylene thin film (A
2) and the nonwoven fabric (B3) were laminated and pressed through a heated air belt to obtain a laminated sheet (sample 5) in which the laminated sheets were integrated. Similarly, a laminated sheet (sample 6) was prepared by laminating a perforated polyethylene film (A2) and a nonwoven fabric (B4), and for comparison, a laminated sheet was prepared by laminating the nonwoven fabric (A1) made in Example 1 and a perforated polyethylene film (A2). Specializes in the J-sheet (sample 7).

Table 2 shows the results of the evaluation of the saline absorption time of each laminated sheet, the liquid absorption and diffusion property of the laminated sheet with the liquid-absorbing material laminated to form a breast milk bunt, and the feeling of wearing the facing material.

Table 2 In other words, the facing material of the present invention had a soft, dry surface with a feel of A, and had a good texture.

〔Effect of the invention〕

The facing material of the sanitary product of the present invention has good liquid absorption and diffusion properties, and it is possible to obtain a sanitary product that is soft and soft to the touch, and has good adhesion to the body.

Patent applicant RiRashi Co., Ltd.

Claims (1)

[Claims] (1) The surface layer is a nonwoven fabric mainly composed of hydrophobic fibers made of a thermoplastic polymer, or a hydrophobic liquid-permeable film (A) made of a thermoplastic polymer, and a hydrophilic fabric made of a thermoplastic polymer. A laminated sheet-like product in which a nonwoven fabric (B) composed of fine fibers and/or hydrophilic agent-added fine fibers is laminated as an absorbent side, and at least a part of the nonwoven fabric (B) is integrated, the laminated sheet-like product having physiological saline. A facing material for sanitary products, characterized in that the absorption time for 1 ml of water is 2 seconds or less.