CN1623018A - Three-dimensional sheet - Google Patents

Abstract

A three-dimensional sheet (10) comprising a 1 st fiber layer (1) containing heat-shrinkable fibers, a 2 nd fiber layer (2) composed mainly of non-heat-shrinkable fibers and containing heat-fusible fibers laminated on one surface thereof, and a 3 rd fiber layer (3) composed of heat-fusible fibers laminated on the other surface of the 1 st fiber layer (1), wherein the 1 st to 3 rd fiber layers have heat-fusible portions (4) formed in a predetermined pattern in the three-dimensional sheet, the heat-fusible portions (4) penetrate from the 2 nd fiber layer (2) to the 3 rd fiber layer (3), and the 2 nd fiber layer (2) is raised in a portion other than the heat-fusible portions (4).

Description

Stereoscopic film

technical field

The present invention relates to a three-dimensional sheet having desired unevenness on the surface and a bulky structure.

Background technique

In Japanese Patent No. 3131557, it is described that on one side of the first fiber layer, thermally fused adhesive fibers made of heat-shrinkable fibers and a resin having a melting point lower than the heat-shrinkage initiation temperature of the heat-shrinkable fibers are laminated by A multi-pleated nonwoven fabric formed of a second fiber layer composed of non-heat-shrinkable fibers. The two fiber layers are integrally bonded in the thickness direction by linear thermal fusion bonding, the thermal fusion bonded portion becomes a concave portion, and the portion between the thermal fusion bonded portions becomes a convex portion, and a plurality of tendon-like pleats are formed on the second fiber layer. The multi-pleated non-woven fabric is prepared as follows: the first fiber layer and the second fiber layer are overlapped, and the two fibers are bonded by heat fusion at a temperature lower than the heat shrinkage initiation temperature of the above-mentioned heat-shrinkable fibers. After the layers are integrated, the heat-shrinkable fibers are heat-shrunk by blowing hot air at or above the heat-shrinkage temperature. However, in this nonwoven fabric, the thermal fusion bonding of the first fiber layer and the second fiber layer depends on the thermal fusion bonding fibers contained in the first fiber layer in an amount of 30 to 50% by weight, so the two fiber layers The joining force is limited. Therefore, when the first fiber layer is thermally shrunk, and when the nonwoven fabric is post-processed or used, the above-mentioned thermally fused bonded portion is easily peeled off, and as a result, the concave-convex pattern becomes unclear, or the desired concave-convex shape may not be obtained. In addition, since the shrinkage temperature of the heat-shrinkable fibers is higher than the melting point of the heat-fusible fibers, the heat-fusible fibers are melted during shrinkage, and the quality and style are deteriorated, making them unsuitable for direct contact with the skin.

In order to improve the joining force of the two fiber layers, it is considered to increase the proportion of the heat-melt adhesive fibers contained in the first fiber layer, or to increase the temperature or pressure during the heat-melt bonding process, but if it is the former, the heat-shrinkable fiber If the ratio is lowered, the shrinkability of the first fiber layer becomes insufficient, and the desired concave-convex shape may not be obtained. In addition, in the latter case, the hot-melt bonded part becomes hard, and as a result, the flexibility of the entire sheet is lowered, and the quality and style are deteriorated.

In addition, when the above-mentioned pleated nonwoven fabric is fixed to other materials and used, the surface on the side of the first fiber layer is fixed to the other material, etc., but in order to ensure shrinkage force, it cannot be fixed in the first fiber layer. A large amount of heat-melt adhesive fibers are used. In addition, since heat-shrinkable fibers such as heat embossing are performed below the shrinkage temperature of heat-shrinkable fibers, heat-shrinkable fibers do not melt. Sufficient joint strength could not be obtained.

Patent No. 3181195 describes a non-woven fabric used as a concave material for surface fasteners, by laminating and shrinking one of the first and second fiber layers partially thermally fused to make the other protrude from the surface. A nonwoven fabric with regular protrusions formed on one side. This non-woven fabric is used by fixing the heat-shrinkable one fiber layer side to another member. In order to ensure the shrinkage force, it is not possible to use a large amount of heat-melt adhesive fibers in this fiber layer. Therefore, even with heat embossing, etc. Even if thermocompression bonding is used to join other members, sufficient joint strength cannot be obtained, and even if it is obtained, it is not good at first, and the quality and style such as skin contact are further deteriorated.

Contents of the invention

Therefore, an object of the present invention is to provide a three-dimensional sheet that has good quality and style, excellent thermocompression bonding properties with other materials, and can form desired unevenness during production.

Another object of the present invention is to provide a three-dimensional sheet fixing method capable of firmly joining a three-dimensional sheet using heat-shrinkable fibers to an object to be fixed made of a fiber material.

The present invention achieves the above-mentioned first object by providing the following three-dimensional sheet, which is laminated (or laminated) on one side of the first fiber layer containing heat-shrinkable heat-shrinkable fibers to avoid heat shrinkage. The second fiber layer containing thermally-adhesive fibers as the main body and containing heat-melting adhesive fibers is laminated on the other side of the first fiber layer. The third fiber layer containing thermally-melting adhesive fibers, wherein the first fiber layer to the second The 3-fiber layer forms a heat-melt bonding part having a predetermined pattern in the above-mentioned three-dimensional sheet, and the above-mentioned heat-melt bonding part penetrates from the second fiber layer to the third fiber layer, and the second fiber layer is outside the above-mentioned heat-melt bonding part The part becomes convex shape (hereinafter referred to as the first invention refers to this invention).

The present invention achieves the above-mentioned second object by providing a method for fixing a three-dimensional sheet by laminating non-heat-shrinkable fibers on one surface of a first fiber layer containing heat-shrinkable fibers. The main body and the second fiber layer containing heat-melt adhesive fibers, and the second fiber layer side of the three-dimensional sheet formed by forming the junction of the first and the second fiber layers in a predetermined pattern is fixed to the side of the fixed object as the fixed object side. On the object to be fixed made of material, wherein the third fiber layer containing heat-fusible adhesive fibers is interposed between the above-mentioned three-dimensional sheet and the above-mentioned object to be fixed, and they are integrated by heat embossing (or embossing) processing (Hereinafter, this invention is referred to as the second invention).

Description of drawings

Fig. 1 is a schematic cross-sectional view showing a three-dimensional sheet as one embodiment of the three-dimensional sheet of the present invention (first invention) and an object to be fixed when it is fixed for use.

2( a ) to FIG. 2( c ) are plan views each showing an example of the formation pattern of the thermal fusion bonded portion formed on the three-dimensional sheet.

Fig. 3 is a schematic cross-sectional view showing a cross-section in the width direction of a sanitary napkin (absorbent article) manufactured using a three-dimensional sheet.

Fig. 4 is a schematic cross-sectional view showing an embodiment of a method for fixing a three-dimensional sheet of the present invention (second invention).

Detailed ways

The present invention will be described below on the basis of its preferred embodiments with reference to the accompanying drawings.

FIG. 1 shows a schematic cross-sectional view of a three-dimensional sheet 10 as one embodiment of the present invention (first invention). The three-dimensional sheet 10 has a three-layer structure in which the second fiber layer 2 is laminated on one surface of the first fiber layer 1 containing heat-shrinkable fibers, and the third fiber layer 3 is laminated on the other surface of the first fiber layer 1 . The first fiber layer 1 is composed of an aggregate of fibers. On the other hand, the second fiber layer 2 and the third fiber layer 3 are respectively composed of fiber aggregates of different types and/or mixed with the fibers constituting the first fiber layer 1 . The second fiber layer 2 and the third fiber layer 3 are composed of aggregates of the same type and mixture of fibers, or aggregates of fibers of different types and/or mixtures.

When the three-dimensional sheet 10 is viewed from above, the thermally fused bonded portions 4 in a rhombic lattice pattern shown in FIG. 2( a ) are formed in the three-dimensional sheet 10 . The thermal fusion bonding portion 4 is formed by partially thermocompression-bonding the first to third fiber layers in a laminated state.

The heat-melt bonding portion 4 penetrates from the second fiber layer 2 to the third fiber layer 3 . The junction of the 2nd fiber layer and the 1st fiber layer and the junction of the 1st fiber layer and the 3rd fiber layer overlap completely in the state which planarly viewed the three-dimensional sheet 10, respectively. The heat-melt adhesive portion 4 is formed by melt-solidification of a heat-melt adhesive resin. As will be described later, the hot-melt adhesive resin is preferably contained in the second fiber layer 2 and the third fiber layer 3 in the state of the hot-melt adhesive fibers containing it. The resin in the 1 fiber layer can be melted and permeated without being completely melted, and is bonded to each other to form a 3-layer bonding. Moreover, it is preferable to contain also in a 1st fiber layer as needed. It is preferred that the thermal fusion bonding part 4 penetrates from the second fiber layer to the third fiber layer in each thermal fusion bonding part of the three-dimensional sheet 10, and in addition, it is preferred that each fusion bonding part penetrates the entire area in the thickness direction of the three-dimensional sheet of this part .

In addition, each heat-melt bonding portion in this embodiment may be circular, but the shape of each heat-melt bonding portion may also be oval, triangular, or rectangular, or a combination thereof. In addition, a shape such as a straight line or a curved line may be formed in which the joint portion is continuous. The formation pattern of the heat-melt adhesive portion 4 can be, for example, the patterns shown in FIG. 2( b ) and FIG. 2( c ).

The area ratio (area of the thermally fused adhesive portion 4 of the three-dimensional sheet 10 per unit area) of the thermal fusion bonding portion 4 with respect to the area of the three-dimensional sheet 10 is determined by the specific use of the three-dimensional sheet 10, etc., but from fully improving the first In terms of the bonding strength of the fiber layer to the third fiber layer, and from the point of view that the convex three-dimensional shape is sufficiently formed by the deformation of the second fiber layer to exhibit bulkiness, after the formation of the heat-melt bonding portion 4 and the first Before thermal shrinkage of the fibrous layer 1, the area ratio is preferably 3-50%, particularly preferably 5-35%, and after thermal shrinkage, it is preferably 6-90%, particularly preferably 10-70%.

The three-dimensional sheet 10 is formed above the shrinkage initiation temperature of the heat-shrinkable fibers contained in the first fiber layer 1 after the first fiber layer in the laminated state to the third fiber layer are partially thermocompression-bonded to form a whole. Manufactured by heat treatment, the portion of the second fiber layer 2 other than the thermally fused bonded portion 4 becomes convex due to thermal shrinkage of the first fiber layer. In the present embodiment, the three-dimensional sheet 10, as shown in Figure 2 (a), has a plurality of closed areas surrounded by thermally fused adhesive parts 4 formed in a rhombus lattice pattern, and in each area of the closure, The second fiber layer 2 is deformed into a dome-shaped convex shape. On the other hand, the thermal fusion bonded portion 4 is relatively recessed compared with the convex portion (also referred to as the convex portion 5) of the second fiber layer 2, so that the surface of the second fiber layer side of the three-dimensional sheet 10 is formed by A concavo-convex shape consisting of a plurality of convex and concave parts. In this embodiment, the same concavo-convex shape is formed also on the third fiber layer 3 side by shrinkage of the first fiber layer 1 .

The first fiber layer 1 contains heat-shrinkable fibers. The heat-shrinkable fibers are in a heat-shrunk state in the three-dimensional sheet 10 . The heat-shrinkable fibers are not particularly limited, and known heat-shrinkable fibers can be used. It is preferable to use latent crimping fibers as heat-shrinkable fibers because the properties of an elastic body are imparted to the first fiber layer 1 and the three-dimensional sheet 10 as a whole exhibits properties of an elastic body. If the three-dimensional sheet 10 has the properties of an elastic body, when the three-dimensional sheet 10 is used as, for example, a constituent member of a disposable absorbent article described later, the followability to the movement of the wearer becomes good, and the absorbent article is suitable for use. The performance is improved and the liquid leakage is effectively prevented, so it is preferable.

Potentially crimped fibers, such as eccentric core-sheath composite fibers or side-by-side composite fibers composed of two types of thermoplastic polymer materials with different shrinkage rates. Examples thereof include fibers described in JP-A-9-296325 or Japanese Patent No. 2759331. Examples of two types of thermoplastic polymer materials having different shrinkage rates include combinations of ethylene-propylene random copolymer (EP) and polypropylene (PP), polyethylene terephthalate (PET), A combination of a copolymer of polyethylene terephthalate and polyethylene isophthalate (CoPET). The heat-shrinkable fibers may be staple fibers or filaments. The thickness is preferably about 1 to 7 dtex.

The heat-shrinkage start temperature of the heat-shrinkable fiber may be, for example, 90 to 110°C. The so-called thermal shrinkage initiation temperature refers to the measured temperature at which the fiber substantially begins to shrink when the fiber is placed in a furnace that can be heated at a certain rate.

The first fiber layer 1 may be composed of 100% heat-shrinkable fibers, or may contain other fibers. Examples of other fibers contained in the first fiber layer 1 include thermally fusible fibers to be described later, for example, thermally fusible fibers contained in the second and/or third fiber layers.

Other fibers may be contained in the first fiber layer 1, and the amount of the heat-shrinkable fiber is 70% by weight or more relative to the weight of the first fiber layer 1 from the viewpoint of not hindering the shrinkage of the heat-shrinkable fiber when the three-dimensional sheet is produced. , particularly preferably 90 to 100% by weight.

Examples of the form of the first fiber layer 1 before thermal shrinkage include a fiber web or a nonwoven fabric in which constituent fibers are not bonded. Examples of the first fibrous layer 1 in the form of a fibrous web include fibrous webs containing heat-shrinkable fibers and formed by a carding method. Examples of the first fiber layer 1 in the form of a nonwoven fabric include nonwoven fabrics that contain heat-shrinkable fibers and are manufactured by various nonwoven fabric manufacturing methods. Examples of the method for producing the nonwoven fabric include thermal fusion bonding, hydroentanglement, needle punching, solvent bonding, spunbonding, and meltblowing.

The second fiber layer 2 is mainly composed of non-heat-shrinkable fibers. The so-called non-heat-shrinkable fibers in this specification include fibers that do not show heat-shrinkability, and fibers that show heat-shrinkability but do not substantially cause heat shrinkage below the heat-shrinkage initiation temperature of the heat-shrinkable fibers contained in the first fiber layer. Both of the fibers.

From the perspective that the first fiber layer becomes more three-dimensional, it is preferable that the amount of non-heat-shrinkable fibers in the second fiber layer 2 is at least 70% by weight relative to the weight of the second fiber layer 2, preferably 90% by weight or more, particularly preferably 100% by weight.

In addition, from the viewpoint of adjusting the three-dimensionality and shrinkability, it is preferable that the second fiber layer contains about 10 to 30% by weight of the same heat-shrinkable fiber as the heat-shrinkable fiber in the first fiber layer.

The second fiber layer 2 and the third fiber layer 3 each contain heat-melt-adhesive fibers. The heat-melt-adhesive fiber is a fiber which contains a heat-melt adhesive resin, and melt-bonds between fibers by the melt-hardening of this resin. From the point of view of further improving the bonding strength of the heat-melt bonded portion, it is preferable that the heat-melt-adhesive fibers contained in the second fiber layer 2 and the third fiber layer 3 contain more heat-shrinkable fibers than those contained in the first fiber layer 1, respectively. Hot-melt adhesive resin with low melting point for fibers. When the heat-shrinkable fibers in the first fiber layer are core-sheath type (eccentric or concentric) conjugate fibers or side-by-side conjugate fibers, it is preferable that the heat-melt-adhesive fibers contained in the second and third fiber layers contain A resin having a lower melting point than the sheath component of the core-sheath conjugate fiber or the heat-melt bonding component of both side-by-side conjugate fibers.

Here, the melting point of the heat-shrinkable fiber refers to the peak value when the heat of fusion is measured by DSC (differential scanning calorimeter).

From the point of view that the thermal fusion adhesive fibers contained in the second fiber layer can be melted and bonded without shrinking the first fiber layer in contact with the skin, the second fiber layer 2 and the third fiber layer are preferably The melting point of the heat-melting adhesive resin contained in the heat-melting adhesive fibers contained in 3 is lower by 10°C or more, particularly preferably 20°C or more, than the melting point of the heat-shrinkable fibers of the first fiber layer. When the heat-melt-adhesive fiber is a multi-component type conjugate fiber, it is preferable that the heat-melt adhesive resin having the lowest melting point is lower than the melting point of the heat-shrinkable fiber of the first fiber layer.

In addition, from the viewpoint of not shrinking the first fiber layer, the heat-melt adhesive fibers contained in the second fiber layer can be melted and have sufficient bonding strength, it is preferable that the second fiber layer 2 and the third fiber layer 3 contain The melting point of the heat-melt adhesive resin in the heat-melt-adhesive fiber is lower than the thermal shrinkage temperature of the heat-shrinkable fiber of the first fiber layer by 30°C or more, particularly preferably 40°C or more.

In addition, from the point that the bonding strength of the first fiber layer to the third fiber layer can be further improved, and the temperature conditions of the heat treatment for integrating them can be carried out at a lower temperature, and the quality and style of the three-dimensional sheet can be further improved. Preferably, the melting point of the heat-melt adhesive resin in the heat-melt adhesive fibers contained in the second fiber layer 2 is the same as the melting point of the heat-melt adhesive resin in the heat-melt adhesive fibers contained in the third fiber layer 3, or the two The difference between the melting points of the hot-melt adhesive resins is within 20°C, particularly preferably within 10°C.

From the point of view of improving the joint strength between the fiber layers of the heat-melt bonding portion 4 and making the quality style of the three-dimensional sheet good, it is preferable that the amount of the heat-melt-bonding fibers contained in the second fiber layer is less than that of the second fiber layer. The weight of layer 2 is 70 to 100% by weight, particularly preferably 90 to 100% by weight.

From the aspects of improving the joint strength between the fiber layers of the heat-melt bonding part 4 and making the quality style of the three-dimensional sheet become good, and improving the thermocompression bondability with other materials, etc., especially with the fiber material, it is preferable The quantity of the heat-melt adhesive fiber contained in a 3rd fiber layer is 70-100 weight% with respect to the weight of the 3rd fiber layer 3, Especially preferably, it is 90-100 weight%.

Examples of the heat-melt-adhesive fibers contained in the second fiber layer 2 and the third fiber layer 3 include polyethylene (PE), polypropylene (PP), polyethylene-propylene copolymer, polyethylene terephthalate Polyethylene glycol ester (PET), polyester such as polybutylene terephthalate, polyethylene terephthalate-ethylene isophthalate copolymer, polyamide-ethylene-acrylic acid copolymer , ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-methyl methacrylate-acrylic acid ternary copolymer composed of fibers. In addition, core-sheath type composite fibers or side-by-side type composite fibers composed of combinations of these thermoplastic polymer materials can also be used. These fibers can be staple or filament. The thickness is preferably about 1 to 7 dtex. When the first fiber layer 1 contains heat-melt-bond fibers, the same fibers as these can be used.

Examples of the form of the second and third fiber layers 2 and 3 before the first fiber layer 1 is thermally shrunk include a fiber web or a nonwoven fabric in which constituent fibers are not bonded. The forms of the second fiber layer 2 and the third fiber layer 3 before thermal shrinkage may be the same or different.

If the form of the second fiber layer is a fiber web, the area and shape of the second fiber layer 2 can be easily changed by shrinkage, and the second fiber layer 2 can easily bulge into a convex shape in the thickness direction, which is particularly preferable. In addition, since the swollen protrusions are filled with fibers, a sheet with good cushioning properties and a soft quality can be obtained, which is preferable. When the second fiber layer 2 and/or the third fiber layer 3 are in the form of a fiber web, the fiber web can be formed by, for example, a carding method. The second fiber layer 2 forms bulky convex portions 5 filled with fibers constituting the fiber web in the three-dimensional sheet 10 formed of the fiber web, and the fibers are oriented along the convex portions 5 . In particular, if the second fiber layer 2 is in the form of a fiber web formed by a carding machine method, and the second fiber layer 2 has a very sparse structure, the three-dimensional sheet 10 of the present invention can permeate or retain high-viscosity liquids. In addition, the compression deformability when the three-dimensional sheet 10 is compressed in the thickness direction is also improved. Examples of high-viscosity liquids include loose stools and menstrual blood, cleansers and moisturizers for humans, and cleansers for objects.

On the other hand, if the form of the second fiber layer is a non-woven fabric before joining and shrinkage, it has the advantages of good conveyability and high strength. In addition, since it is not necessary to melt-bond the constituent fibers of the second fiber layer after bonding with the first fiber layer, there is also an advantage in that the shrinkage temperature can be selected from a wide range.

The three-dimensional sheet 10 of this embodiment is produced as follows, for example, using a known method to manufacture the first fiber layer to the third fiber layer respectively, and make them overlap so that the first fiber layer 1 is sandwiched by the second fiber layer 2 And between the 3rd fiber layer 3, then use the hot embossing roll device that is made up of concave-convex roll or concave-convex roll and smooth roll, make the laminated 1st fiber layer to the 3rd fiber layer partly (partially) with predetermined pattern ) thermocompression bonding, and then, the heat-shrinkable fibers contained in the first fiber layer 1 are shrunk by heat treatment at or above the heat-shrinkage temperature of the heat-shrinkable fibers. In addition to the method of blowing hot air to the laminated and integrated first to third fiber layers, the method of heat treatment can also use methods such as microwave, steam, infrared rays, and hot roller contact.

According to the three-dimensional sheet 10 of this embodiment, under the state of overlooking this three-dimensional sheet 10, the heat-melt bonding part 4 of the predetermined pattern that forms penetrates from the 2nd fiber layer to the 3rd fiber layer, therefore can improve from heat-melt bonding. Bond strength of the 2nd fiber layer to the 3rd fiber layer in part 4. Therefore, while sufficiently maintaining sufficient shrinkage of the first fiber layer and joint strength from the second fiber layer to the third fiber layer, for example, thermocompression bonding during production can be performed at a relatively low temperature. . Therefore, it is possible to obtain a three-dimensional sheet that is soft and has a good quality when touching the skin.

In addition, by thermally compressing (thermally embossing, etc.) the side of the third fiber layer to the side of other materials (also referred to as the object to be fixed 6) to be fixed to the three-dimensional sheet 10, the three-dimensional sheet 10 can be firmly thermocompressed. Connect to the other materials, so that the three-dimensional sheet 10 and the object to be fixed are not easy to peel off.

Fig. 3 shows following state: take the 3rd fiber layer side as this fixed object side, make the three-dimensional sheet 10 of above-mentioned structure be fixed on the sanitary napkin (absorbency article) on the absorbent body 61 and the leak-proof sheet 62.

That is, in the central region of the sanitary napkin, the three-dimensional sheet 10 is thermocompression-bonded to the skin-contacting surface side surface of the absorber 61 by heat embossing using a heat-sealing apparatus, An annular central anti-leakage groove is formed on the skin-contacting surface of the sanitary napkin. In addition, the three-dimensional sheet 10 is similarly bonded to the leak-proof sheet arranged on the absorber 61 by thermal embossing using a heat-sealing device on both sides of the sanitary napkin in the longitudinal direction. The portion 72 forms a pair of side leakage prevention grooves on both sides of the central leakage prevention groove on the skin contact surface of the sanitary napkin. In addition, the surface of the absorber in the thermocompression bonding portion 71 is formed of cardboard made of cellulose fiber material, and the leakage prevention sheet 62 in the thermocompression bonding portion 72 is formed by laminating polyethylene on the cellulose fiber material. In addition, since the leak-proof sheet 62 has better adhesiveness, it was used with the lamination side (polyethylene) facing the surface sheet side (the same applies to Examples and Comparative Examples described later).

In the two thermocompression bonding parts 71, 72, when adopting heat sealing device to carry out heat embossing processing, the thermal fusion adhesive resin in the 3rd fibrous layer melts and solidifies with the state that enters between the constituent fibers of fixed object 6, so The separation between the three-dimensional sheet 10 and these fixed objects 6 is not easy to occur.

In addition, as the heat-sealing device, conventionally used heat-sealing devices for groove formation, heat-sealing devices for end-seal portion formation, and the like can be used in sanitary napkins, disposable diapers, and the like. In addition, in FIG. 3, illustration of the uneven|corrugated etc. formed on the surface of the three-dimensional sheet 10 is abbreviate|omitted. In the sanitary napkin shown in Fig. 3, the three-dimensional sheet 10 is used as the liquid-permeable surface material (surface sheet), and between the three-dimensional sheet 10 and the liquid-impermeable back material (back sheet) 8 There is an absorbent body 61 having liquid retentivity. The three-dimensional sheet 10 is fixed on the leak-proof sheet 62 and the back material 8 with a hot-melt adhesive 91 near both sides of the absorber 61 , and the leak-proof sheet 62 is fixed on the back material 8 with a hot-melt adhesive 92 .

Fig. 4 shows the preferred embodiment of the three-dimensional sheet fixing method of the present invention (the 2nd invention), and the three-dimensional sheet 10 ' shown in Fig. 4 is laminated with a non-thermal The first fiber layer 1 and the second fiber layer 2 form a heat-melt bonded part (junction part) 4 having a predetermined pattern. The three-dimensional sheet 10' has the same structure as the above-mentioned three-dimensional sheet 10 except that the third fiber layer is not laminated on the other surface of the first fiber layer 1. In the three-dimensional sheet 10', the first fibrous layer 1 and the second fibrous layer 2 are heat-fused and bonded in the same pattern as the three-dimensional sheet 10, thereby forming the fusion-bonded portion 4 of the above-mentioned predetermined pattern. The respective preferred configurations of the first fiber layer 1 and the second fiber layer 2 are the same as those of the first fiber layer and the second fiber layer in the three-dimensional sheet 10 .

In the fixing method of the three-dimensional sheet of the present embodiment, when the three-dimensional sheet 10' is fixed to the absorber 61 of the sanitary napkin (absorbent article) as the object to be fixed 6 made of fibrous material by embossing, Make the 3rd fibrous layer containing thermal fusion adhesive fiber manufactured separately with this three-dimensional sheet 10' between the second fibrous layer 2 of the three-dimensional sheet 10' and the object to be fixed 6, and implement from the three-dimensional sheet 10' side Hot embossing.

Adopt the fixation method of this embodiment, adopt heat-sealing device to carry out the part of thermal embossing processing, be the same as above-mentioned three-dimensional sheet 10, through the thermal fusion bonding of the thermal fusion bonding fiber in the 1st fiber layer and the 3rd fiber layer. The melting and solidification of the bonding resin makes the second fiber layer 2 and the third fiber layer 3 extremely firmly bonded together, and at the same time, during the heat embossing process, due to the thermal fusion of the bonding resin in the third fiber layer, the object to be fixed is trapped The state between the constituent fibers is melted and solidified, so sufficient bonding strength can be obtained between the three-dimensional sheet and these objects to be fixed.

The invention is not limited to the embodiments described.

The three-dimensional sheet of the present invention is suitably used, for example, as a constituent member of a disposable article that is discarded after being used once or several times. In addition, it can also be used as a concave material (ring material) or a convex material of a surface fastener. It is particularly suitable as a constituent material of disposable absorbent articles such as sanitary napkins and disposable diapers, cleaning wipes, and disposable wipes such as human wipes. When used as a constituent member of a disposable absorbent article, such as an absorbent article having a liquid-permeable surface material, a liquid-impermeable backside material, and an absorbent body interposed between two sheets, it constitutes a part of the member Can be used as part of any component such as face material, back material or side body flaps.

When using thermal embossing to fix the three-dimensional sheet of the present invention to other materials, etc. Sheets etc. However, especially in the case of an object to be fixed made of a fibrous material, especially the above-mentioned absorbent body of disposable absorbent articles such as sanitary napkins or disposable diapers, etc., soft objects to be fixed that are deformed due to compression Under the situation, the effect of the present invention embodies more remarkably.

Below in conjunction with embodiment the present invention is described in more detail. However, the scope of the present invention is not limited to this embodiment.

Example

(1) Manufacture of the first fiber layer

As the heat-shrinkable fiber, a latent crimping core-sheath composite fiber (trade name: CPP, manufactured by Daiwa Bou Polytec Co., Ltd., core: polypropylene (melting point 165-170° C.), sheath: ethylene-propylene copolymer (melting point 145-147° C.) was used. ℃), core/sheath weight ratio = 5/5, fineness 2.2dtex, fiber length 51mm, heat shrinkage initiation temperature 90 ℃). With this fiber as raw material, after forming fiber web with roller carding machine, pass through embossing roll (28% of embossing rate, temperature condition: pattern 145 ℃, speed 80m/min), make it pass through cooling roll, form unit area weight 20g/ ^m2 thermal roll non-woven fabric for the 1st fiber layer.

(2) Manufacture of the second fiber layer

As the heat-shrinkable fiber, a core-sheath composite fiber (trade name SHW6) manufactured by Daiwa Bou Polytec Co., Ltd. was used, the core polyethylene terephthalate (melting point 250-255° C.), sheath: polyethylene (melting point 128-130° C. ℃), core/sheath weight ratio=5/5, denier 2.2dtex, fiber length 51mm). With this fiber as raw material, after the fiber web is formed with a roller carding machine, it is passed through a wind-through method heat treatment machine (speed 138m/min, through-air velocity 1m/sec, treatment time is about 10 seconds) to form a fabric with a weight per unit area of 12g/m ² Air-permeable nonwoven fabric for the second fiber layer.

(3) Manufacture of the third fiber layer

The air-through nonwoven fabric obtained in the same manner as the production of the above-mentioned second fiber layer was used as the third fiber layer.

(4) Manufacture of three-dimensional film

The above-mentioned first fiber layer to the third fiber layer are overlapped and bonded with an embossing roll (pattern roll 145°C, flat roll 135°C, embossing handle Figure 2(c), spot diameter 1.5mm, area ratio 7.4%) . Then, heat-shrink quickly with a needle tenter (wind speed up and down is about 4.2m, temperature is 110°C to 116°C, and processing time is about 14 seconds), and it is set mechanically to make it shrink to the length of the size before processing. 70%, 70% wide. The weight per unit area of the prepared nonwoven fabric was about 84 g/m ² .

comparative example

A three-dimensional sheet was produced in the same manner as in the examples except that the third fiber layer was not bonded and then shrunk.

[Performance Evaluation]

Using each prepared three-dimensional sheet as a surface material for absorbent articles, 100 or more sanitary napkins having the cross-sectional configuration shown in FIG. 3 were continuously produced for each sheet. Each three-dimensional sheet was fixed to the surface made of cardboard (about 16 g/m ^{2 ) in the absorbent body 61 (about 250 g/m 2 )} with a hot roll at a temperature of 190° C. (heat embossing) At the same time, it is fixed to the paper laminated with a waterproof polyethylene sheet (the lamination weight per unit area is about 7g/m ² , and the basis weight of the paper is 16g/m ² ) On the leak-proof sheet 62 formed.

Regarding the sealability of the thermocompression bonded portion 71 fixed to the absorbent body 61 and the thermocompression bonded portion 72 fixed to the leak-proof sheet 62 for each manufactured sanitary napkin, the presence or absence of floating of the pattern portion was visually observed. Table 1 shows the number of sanitary napkins that were judged to have no problem with the appearance of the thermocompression bonded portion (good appearance) according to the following evaluation criteria (N=100).

<Evaluation criteria>

Appearance is good: The shape of the sealing area is clearly bonded to the base material, and there is no floating (bulge) at all.

Defective appearance: A part of the shape of the sealed area is not clear, and a part or the whole of the seal area has floating.

Table 1 Thermocompression part 71 Thermocompression part 72 Example 100 98 comparative example 0 88

Out of 100 sanitary napkins, the number of seal parts with good appearance

From the results shown in Table 1, it can be seen that the three-dimensional sheet of the example (the product of the present invention) has excellent thermocompression bondability with the absorber and the leak-proof sheet, and has excellent thermocompression bonding properties with other materials, especially fibrous materials. Excellent thermocompression bonding properties.

In contrast, in the three-dimensional sheet of the comparative example, the shape of the sealing region was partly unclear, or some or all of the seal area was raised, and there was a problem in product performance.

The three-dimensional sheet of the present invention has good quality and style, excellent thermocompression bondability with other materials, and can form desired unevenness during manufacture.

According to the fixing method of the three-dimensional sheet of the present invention, the three-dimensional sheet using heat-shrinkable fibers can be firmly bonded to an object to be fixed made of a fiber material.

Claims (7)

1. A three-dimensional sheet comprising a second fiber layer mainly composed of non-heat-shrinkable fibers and containing heat-melt-adhesive fibers on one surface of a first fiber layer containing heat-shrinkable heat-shrinkable fibers , on the other side of the first fiber layer, laminate the third fiber layer containing heat-melt adhesive fibers, wherein the first fiber layer to the third fiber layer form a heat-melt bond with a predetermined pattern in the above-mentioned three-dimensional sheet part, the above-mentioned heat-melt bonding part penetrates from the second fiber layer to the third fiber layer, and the part of the second fiber layer other than the above-mentioned heat-melt bonding part is convex. 2. The three-dimensional sheet according to claim 1, wherein the heat-melt adhesive fibers contained in the second fiber layer and the third fiber layer contain a heat-melt adhesive resin having a melting point lower than that of the heat-shrinkable fibers. 3. The three-dimensional sheet according to claim 1, wherein the melting point of the heat-melt adhesive resin in the heat-melt adhesive fibers contained in the 2nd fiber layer is the same as that of the heat-melt adhesive fibers contained in the 3rd fiber layer. The melting points of the two hot-melt adhesive resins are the same, or the difference between the melting points of the two hot-melt adhesive resins is within 20°C. 4. The three-dimensional sheet according to claim 1, wherein the third fiber layer side is fixed to the fixed object made of a fiber material as the fixed object side by thermal embossing. 5. The three-dimensional sheet according to claim 4, wherein the object to be fixed is an absorber of absorbent articles such as sanitary napkins and disposable diapers. 6. A method for fixing a three-dimensional sheet, wherein, on one surface of the first fiber layer containing heat-shrinkable fibers, a second fiber layer containing non-heat-shrinkable fibers as the main body and heat-melt-adhesive fibers is laminated, And the 2nd fiber layer side of the three-dimensional sheet formed by forming the junction part of the predetermined pattern with the 1st fiber layer and the 2nd fiber layer is fixed on the to-be-fixed object made of fibrous material as the fixed object side, Furthermore, a third fiber layer containing heat-fusible fibers is interposed between the above-mentioned three-dimensional sheet and the above-mentioned object to be fixed, and they are integrated by heat embossing. 7. The fixing method of the three-dimensional sheet according to claim 6, wherein the object to be fixed is an absorber of absorbent articles such as sanitary napkins and disposable diapers.

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