KR840000972B1 - Gatherable laminated structure including an apertured elastic member - Google Patents

Abstract

A laminated structure to compact the human body consists of two adjacent layers of twistable, squeezable materials. Porous elastic members of elastic matter are inserted between the above layers, so that the two layers are fixed through the pores of the elastic members. The product is used for baby diapers.

Description

Tightened laminated structure with built-in pore elastic body

1 is an enlarged perspective view showing a mesh-like elastic body that can be used in one embodiment of the layer structure of the present invention.

2 is a perspective view showing the disposable diaper according to the present invention laid out in a plane.

FIG. 3 is an exploded perspective view showing the difference between the diaper elements shown in FIG.

4 is a perspective view showing another embodiment of a disposable diaper for practicing the present invention.

5 is a perspective view showing another embodiment of a disposable diaper for practicing the present invention.

6 is a plan view showing an embodiment of the disposable diaper of the present invention partially cut to show the interior in detail.

7 is an enlarged cross-sectional view taken along line 7-7 of FIG.

8 is a plan view of another embodiment of a disposable diaper of the present invention partially cut to show the interior in detail.

9 is a plan view of another embodiment of the disposable diaper of the present invention partially cut to show the interior in detail.

10 is a plan view of another embodiment of a disposable diaper of the present invention partially cut to show the interior in detail.

11 is a plan view of another embodiment of the present invention partially cut to show the interior in detail.

12 is a plan view of the disposable underwear according to the present invention folded in a plane to show the interior in detail.

Fig. 13 is a perspective view of the disposable undergarment of Fig. 12 in a shape when worn.

14 is a flow diagram illustrating one embodiment of a method of assembling the components of a disposable diaper according to the present invention.

The present invention relates to an improved layered structure that is used to tighten to fit a particular part of the human body. In recent years, there has been an increasing demand for the development of inexpensive clothes, new and inexpensive structural parts, and manufacturing methods of garment products.

In some cases, costumes have been required that are very inexpensive enough to wear. New elastomeric materials and methods of using them as part of clothing have also been developed to meet the demand for this type of clothing to fit the human body. For example, US Pat. No. 3,639,917 describes a method for use as a strip of heat recoverable elastomeric material that can tighten the end of a disposable hospital ward.

Disposable diapers with elastic bodies or elongates attached to the length of the diaper have been commercially available in order to have elasticity around the legs of babies when using children's diapers. Examples of stretchable diapers with elastics attached to the longitudinal edges of the diapers are described in US Pat. Nos. 3,860,003 and 4,050,462. When used in a baby, the diaper can be squeezed around the leg of the child by elastically contracting the longitudinal side of the diaper which becomes the part surrounding the leg and thigh of the diaper. Because of this squeezing, diapers are less likely to come off the baby's legs and the tighter they are, the less they are likely to come off. However, if the fit is too tight, it causes painful irritation to the soft part of the thigh, especially when the diaper is wet. There are also several patents that disclose how to stretch the waistline of disposable diapers that fit the diaper tightly at the waistline of the wearer, such as those described in U.S. Pat. have. Disposable diapers consist of a front layer and a backing layer having an almost equally stretchable and slightly smaller absorbent core or absorbent plate sandwiched therebetween. The front layer and backing are bonded to each other with a heat soluble adhesive or other known adhesive material around them. In manufacturing a stretch diaper, an elastic body that is in an extended or partially extended state is sandwiched between the front portion and the backing portion along one or more edges of the diaper. This elastic body is glued to either the front and / or backing portions by an adhesive or similar method to form the elastic portion at the base of the diaper. An example of a method of inserting an elastomer in a disposable diaper is disclosed in US Pat. No. 4,081,301.

When these elastic bodies are used for a disposable diaper, both the material cost and manufacturing cost of this disposable diaper will increase. The non-porous solid elastic bodies need to be attached to each other by directly adhering the side edges of the front sheet and the supporting sheet or by adhering them to the elastic bodies. In addition, in order to simplify the manufacturing process, it is necessary to use the same adhesive through the entire process of attaching the elastic body to the diaper, so that the adhesive can be mixed with the elastic body, the plastic film backing material and the soft fabric backing material, and have adhesiveness. Will be. In addition, when adhesively fixing an elastic body without a hole in a disposable diaper, the selected adhesive should be elastically polymerizable or intermittently used, otherwise the adhesive may become too hard to lose its ability to tighten. do.

In contrast, the pore elastic body of the present invention does not need to be bonded to either the front portion or the support portion, and the adhesive used to fix the front portion to the support portion does not need to have elastomeric property, but only the front portion and the support portion. It can be mixed with the part and has adhesiveness, but has nothing to do with the elastic body.

The inventors of the present invention relate to an improved layered structure used to tighten to fit a particular part of the human body and a method of manufacturing the same. This layered structure consists of a primary layer and a secondary layer substrate of flexible tightenable material and a pore elastomer positioned between these layer substrates.

The elastic body has a plurality of elastic materials connected to each other to form holes, and in the laminated structure, the primary and secondary layer substrates are fixed together through a certain number of spheres. The laminated structure of the present invention can be used for any custom-made clothing, but it is inexpensive, and it is judged that it is most suitable for use in clothes that can be discarded after use. This layered structure can be used as part of clothing sleeves, leg wraps, neck and waist. In particular, this layered structure can be used as part of both the waist and thigh circumference of disposable diapers or other disposable underwear.

The improved laminate of the present invention reduces the pressure on the wearer's skin and reduces the likelihood of irritation and rash when wet in disposable diapers or underwear. Surprisingly, these perforated elastomers can be easily sandwiched between primary and secondary layer substrates and these substrates can be easily bonded at high speed with good reliability and low cost while keeping the elastomer in place.

In addition, the present invention in a layered structure in which a layer is fixed through a hole in a pore body as compared to a similar structure using a non-porous elastic body on which one side or both sides of a solid body has to add a separate adhesive layer or an adhesive thickness. In the case of using the pore body, the thickness of the final layer structure can be reduced.

The thickness of this layer reduced by the use of elastomeric holes is a major cause of the mass loss of the tightening part, which reduces the tightening force in the final product. This reduced thickness and combination of holes is also an unexpected effect of better uniform distribution of the elastic force delivered directly to better fit the wearer's end circumference, for example the leg circumference of the base product, and to better match. Added.

인치 내지

이치의 폭을 갖고 1내지 50밀, 호적하게는 5 내지 20밀의 두께를 갖도록 한다. 이 탄성체는 신장하였다가 회복될 수 있고 100% 신장에서 평방인치당 약 20 내지 2000파운드의 탄성계수를 갖는 보통의 필름물질이면 어느 것으로도 만들수 있다.According to the present invention, the improved layered structure of the inventors consists of a porous elastomer comprising a plurality of interconnected elastic materials forming holes with the primary and secondary layer substrates of a flexible and tightenable material. The primary and secondary layer substrates are fixed to each other through at least some of the holes. Preferably this elastomer is about

Inches to

It should be 1 to 50 mils wide, preferably 5 to 20 mils thick. This elastomer can be stretched and recovered and can be made of any common film material having an elastic modulus of about 20 to 2000 pounds per square inch at 100% elongation.

In the disposable diaper according to the invention, the elastic body may be positioned between the base and the front of the diaper at the lengthwise edge of the diaper. In one method of disposable diaper production using the layered structure of the present invention, the front and back portions of the diaper are adhesively fixed to each other as in the past. That is, the adhesive is placed on the base and the absorbent core is fixed at the center of the base and the front part is glued at the edges.

The holes of the elastic body placed on one or more edges of the base allow the adhesive placed on the base to adhere to the front side through the holes. Also, when using this new perforated elastomer to bond the front part to the base through the hole, there is no need to adhere the front part to the base outside the elastomer, which is usually required when using a solid without holes. .

It can be pointed out that the use of a mesh-like or perforated elastic body in accordance with the present invention simplifies the insertion and adhesion of the elastic body into the product and thus has considerable economic advantages in the manufacturing process.

The holes or openings ensure a uniform intermittent layer between the stretchable and non-stretchable layers and reduce the critical point of adhesive use. In addition to the adhesion of the layered film through the openings or holes, these openings or holes act more like the original radial or hole-like elastomers in elongation and recovery and similar elasticity, further improving the quality and performance of the final product. You can certainly make corrections. In comparison, when non-solid solids are used, the behavior of the final product in relation to stretchability, resilience or similar resilience changes due to the method and extent of adhesion to the inelastic layer and the properties of the inelastic layer.

In addition, when the elastic body of the present invention having a horizontally and vertically developed element forming a square or rectangular hole is stretched in the longitudinal direction, ″ necking down ″ of the elastic body, that is, reduction of the width of the elastic body does not occur.

This transverse stability makes it very easy to align the elastics in line with the elastics deployed at or near the overlapping material, thus providing a new and improved fit between the layers according to the invention. There are significant advantages inherent in the method. In addition, even when the elasticity of the elastic body is released, the expansion of the elastic body and the incidental expansion of the contact portion for fixing the elastic body to the material in which the elastic body overlaps do not occur.

In the layered structure of the present invention, the pore elastic body is easily stretched, preferably thermoplastic, having a constant minimum elastic recovery. As used herein, the term "elastic" refers to sheets, films, reburns, filaments, and the like, having a recovery of at least 90% as measured by the following formula by stretching to within 10% of the elastic yield point.

Where L _o = original length of the specimen

L _e = Maximum elongated length

L _t = length of specimen measured 3 seconds after elongation is resolved

)로 할수 있으며 또 호적하게는 약 5 내지 20밀로 하고, 폭은 1/4인치에서 2인치로 하고 또 어린이 기저귀에 사용할 때는 가급적 1/2 내지 1 인치 목으로 하는 것이 바람직한 것으로 판명되었다.The thickness of the elastic body is about 1 to 50 mils (

It is found that it is desirable to use about 5 to 20 mils, preferably 1/4 to 2 inches in width, and preferably 1/2 to 1 inch neck when used in children's diapers.

In order to increase the extensibility, the elastic modulus when the elastic body is 100% elongated should not exceed about 2000 pounds / square inch, and it is preferable to considerably lower it to about 2000 pounds / square inch or less, and most preferably, It is preferred to lower it to about 75 to 400 pounds per square inch.

As used herein, the term "mesh" refers to a structure having openings or holes that are almost uniformly distributed to form a mesh structure.

As shown in FIG. 1, the openings or holes 20 of the mesh-like elastic body 21 are rectangular, but a rectangular or square shape is not necessary in the present invention, and the openings may have a circular, elliptical or other shape. There is also.

The "pore" elastomers of the present invention need not have a uniform and uniform array of holes, such as the rectangular holes of the mesh, but may simply comprise multiple interconnected elastomeric materials that form the holes. Depending on the elastic modulus of the material used and the thickness and width of the elastomer, the number of openings can range from two to 100 openings per inch in both longitudinal and transverse directions of the elastomer. In addition, the elastic material may have a different width in the vertical or horizontal direction, and the spacing between the materials may be different in the horizontal and vertical directions.

Referring to FIG. 2, the disposable diaper 25 embodying the present invention has longitudinal edges 26 and 27. The central part of each mat is elastic to fit around the baby thigh. The elastic bodies 28 and 29 at both edges in the longitudinal direction are made of a mesh-like film body according to the present invention. The individual components of the disposable diaper of FIG. 2 are shown in FIG.

The diaper additionally has a rectangular absorbent batt 31, which is made of a material which is impermeable to moisture, and which is superimposed with a series of adhesive lines 35 superimposed on and supported by the primary layer or backing layer 30 and fused to the backing layer. And a secondary layer or front layer 32 made of a material that can penetrate moisture and placed in a manner overlapping the batt. The absorbent batting has a smaller area than the backing layer when placed near the center of the backing layer and is positioned to have space on both the transverse and longitudinal sides of the diaper. The absorbent batt has a mesh-like elastic body 28 and 29 at the edge in the longitudinal direction, which are generally placed parallel to the long edge of the batt. In addition, the cotton is fixed between the supporting layer and the front layer using the fixing line 35 in the unfolded state. The surface layer 31, through which moisture can penetrate, is superimposed on the absorbent batting and fixed to the support layer using the end and side portions of the adhesive wire 35.

The face layer is also fixed to the backing layer between the openings of the mesh-like film body. In order to fix the diaper on the baby, the tapes 33 and 34 are attached to the diaper. At the time of manufacturing the diaper, only the central portions 36 and 37 of the mesh bodies 28 and 29 are kept elastic and fixed between the front layer and the backing layer. It should be noted that the elastic ends that are not adhered to the front layer and / or backing layer may or may not be meshed as desired. In the case of using a mesh or an elastic body having holes, the material cost can be reduced compared to using an elastic body having no holes of the same length and width used to apply a tightening force to the longitudinal edges.

The mesh elastic of the present invention may be produced by various methods such as passing a suitable stretchable and recoverable film between the shape forming roll and the supporting roll in a manner similar to that shown in US Pat. Nos. 3,881,381 and 3,632,269.

A technique that can be used to produce a diaper according to the present invention is to directly apply an adhesive to the mesh elastic body along the portion that needs to be bonded between the backing and the front layer. Another technique is to apply an adhesive to the portion of the backing layer or front layer on which the elastic body is to be fixed. In assembling the diaper, pressure is applied to the diaper in the elastic zone to bond the front layer and the backing layer together through the opening of the elastic body.

The components of the disposable diaper may be assembled according to one embodiment of the present invention as shown in FIG. The backing layer 180, the absorbent batt 182, the front layer 184, and the continuous elastic sieving burner 186 are placed in the assembly position. The elastic body is stretched on the way to the assembly unit by operating the shock roller 200, which is lower than the rotational speed of the compression roller 190.

In this embodiment the adhesive is applied to the elastic body with a nozzle 188. Pressure is applied to the diaper assembly by passing at least an elastic part through the compression section of the compression roller 190. In certain preferred embodiments, the surface of one roller may be made elastic.

The pressure exerted on the diaper to bond the backing layer to the front layer causes the adhesive to squeeze out through the opening in the elastomer so that the backing layer is applied to the front layer even when the adhesive is applied to only the original backing layer and either the front layer or the surface of the elastomer. It can be bonded.

In order to ensure that the front layer and the backing layer adhere to each other through the openings of the elastic body, it is desirable to make the upper compression roller 190 made of a very elastic material or to cover the outer surface with a very elastic cover. The resilient surface causes the roller surface to bend into the elastomeric opening and compress the thin areas with only the front and backing layers together.

Elastomeric portions that are not secured by the diaper construction may allow the front layer and the base to shrink into the diaper. There are several ways to shrink a portion of an elastic body without tightening the material layer. One such technique is to fix the elastomer with the front layer and / or the backing layer only in a portion of the elastomer.

When the elastic body is cut at an unfixed part such as cutting with a cutting knife 192 and a supporting roller and bill 194 to make a separate diaper, the unfixed part of the elastic body is the area where the elastic body is fixed to the front layer or the supporting layer. To contract. This shrinkage has no effect of tightening in the front and backing layers.

Either no adhesive is applied to a specific zone, or no pressure is applied to a specific zone until after the elastomer has been cut off, or a portion of the elastomer is treated with a release agent such as silicone to prevent the elasticity of the elastic body from adhering to the front or backing layer, or It is also possible to prevent the elastic body from sticking to the front and backing layers at certain points using various techniques, such as other methods of preventing part of the front and backing front layers from tightening.

An important and unexpected advantage of using new mesh-like elastomers with square or rectangular openings, as described above, is that the elastomers are ″ neck-down ″, i.e., when they are stretched in the longitudinal direction, reducing their width or transverse dimension. The phenomenon does not cause. This is very important because the elastic body is in a deployed state in the longitudinal direction when attached to the diaper. The elimination of neck phenomenon allows this elastic body to be attached in the correct position. The elastic body may be positioned at the shortest edges of the front and backing layers so that all materials can be used as the layer part of the final product so that other materials do not deviate outside the elastic body without trimming the edges. Moreover, the tolerance required to properly insert the elastomer into the diaper is reduced.

The above advantages simplify the manufacturing process of this diaper and increase productivity, and as a result are economically beneficial. 4 is a mesh with all four edges, i.e., two longitudinal edges 41 and 42 and the front and rear ends 43 and 44 being elastic at the center between the front and backing layers. Another disposable diaper 40 similar to that shown in FIG. 2 is shown except that the elastic body is fitted.

FIG. 5 shows a disposable diaper 50 similar to the diaper shown in FIG. 2, except that the front elastic waist portion 52 of the diaper has a mesh-shaped elastic body 51 to fit well around the waist of the child. have.

In the embodiment shown in FIG. 6, a disposable diaper 60 is shown having a substantially rectangular valve 61 sandwiched between the backing layer 62 and the front layer 63, which valve 61 is shown. The edge portions 64 and 65 are formed together with the backing layer and the front layer. Curved cutouts are provided at the centers of the sides of the front and backing layers, respectively, for better fit.

The pre-rolled mesh thermoplastic elastomer 68 is positioned at the longitudinal edge portion and fixed to the backing layer and the front layer along the longitudinal side of the absorbent plate. The mesh elastic bodies were not stretched at their end positions 69 and 70.

A technique used to make the end of the thermoplastic elastomer non-elastic is a method of heating the end sufficiently in the heating zone to remove the elasticity of the thermoplastic material, which is filed on December 21, 1979 together with the related art. It is disclosed and described in the pending patent application No. 106,336, which is used as a reference in the text. The adhesive line 71 fixes the front layer and the absorbent plate to the support layer, and the adhesive tape lines 72 and 73 provide the diaper fixing means.

Referring to FIG. 7, it is a cross-sectional view taken along line 7-7 of FIG. 6 and is a mesh-type elastic revolver fixed between the supporting portion 62 and the front portion 63 by the adhesive lines 74 and 75. An opaque pedestal 62 with 68 is shown.

In the embodiment shown in FIG. 8, disposable diaper 80 has an absorbent batt 81 and also has curved side cuts, which are a front layer 82 and a backing layer having similar cuts. It is sandwiched between (83). Adhesive line 84 serves to fix the sock and the front layer to the backing layer. Mesh-shaped elastic ribs 85 are generally located in the rectangular diaper side portions.

The mesh-shaped elastic reversal is fixed between the front layer and the backing layer at the central portion 86 with an adhesive line 88, which can be applied at the same time as the adhesive line 84, Can be placed along the lines.

The protrusions 89 and 90 of the absorbent batting overlap the four corners of the diaper and also prevent the elastomer from sticking to the front layer in these zones. Adhesion prevention at each end of the elastic body may be performed by other various methods.

As another method, there is a method of applying an adhesive in a suitable manner so that the mesh-like elastic body does not adhere at its ends.

Another method is to use heat or other energy at these ends to loosen the elasticity or burn the elastic body, such as the method described in US Patent Application No. 872,860 during the pending examination. Adhesive tape strings 91 and 92 are used as a means for fixing to the backing layer and for fixing the diaper to the child.

In the embodiment shown in FIG. 9, the disposable diaper 100 of the present invention is composed of an impermeable support 101, a watch glass-type absorbent pad 102, and an upper front layer 104. In this arrangement the top layer and the impermeable backing layer form zones 105 and 106 as part of the peripheral edge. This peripheral edge band does not have an absorbent core material. This reduces the size of the thick material between the child's legs. On each side of the diaper a mesh elastic body 109 is inserted between the impermeable backing layer and the permeable front layer.

The diaper has an absorbent body in the form of a watch glass in which the waist absorber is wider than the crotch absorber.

Adhesive tapes 113 and 114 are attached to the supporting part at the back of the diaper waist.

The embodiment shown in FIG. 10 is a disposable diaper 120 composed of a rectangular impermeable backing portion 121 having an absorbent core 122 with a small area bonded to the adhesive line bonded to the backing portion.

Above the absorbent core is a front portion 124 which is developed together with the supporting portion to form the longitudinal side portions 125 and 126 and the end recesses 127 and 128.

As a preferable structure, the mesh-shaped elastic body 129 is adhere | attached at the front waist part 128 between a support part and a front part. If necessary, a similar mesh-like elastic body may be inserted into the back portion 127 of the diaper. Adhesive tape strings 133 and 134 are glued to the base and used to secure the diaper to the child's body. Elastomers suitable for use in spherical diapers can be made from extruded, roller calendered, or otherwise formed films, with a desired thickness and opening using low elongation materials made from rubbery elastomeric materials. It can have the shape of. In particular, unvulcanized thermoplastic compositions made of elastomeric components and, if necessary, relatively low molecular weight thermoplastic polymers and blendable variants which are solid at ambient temperatures are known to be suitable for the production of elastomers suitable for use in the present invention.

Illustrative elastomeric components suitable for the purposes of the present invention are block copolymers comprising a terminal thermoplastic polymer block and a predetermined amount of non-terminal or mesoelastic polymer blocks. This general form of block copolymer can be prepared using a staged polymerization initiator such as an organolithium compound. Such block polymerization techniques are well known in the art.

The elastomeric component may be a linear or radial A ¹ -BA ² block copolymer with a simple A ¹ -B block copolymer or mixtures thereof, wherein A ¹ and A ² may be similar or may be another material, thermoplastic Polymer blocks such as poly (vinylarene) blocks, and B represents an elastomer block such as conjugated diene or lower (ie, C ₁ -C ₄ ) alkenes. The variant component is a low molecular weight thermoplastic polymer having an average molecular weight of about 500-7500 and is present in the composition in an amount of from 0 to about 200 parts by weight per 100 parts by weight of the elastomeric component.

Preferred thermoplastic film compositions for the production of elastomers consist of the following general arrangement, an elastomeric component containing, as a main component, an unvulcanized linear block copolymer in the form of A ¹ -BA ² , wherein A ¹ and A ² and B are It has the same meaning. In these block copolymers, A block is derived from styrene or styrene homologue, and B block is derived from conjugated diene or lower alkene.

The thermoplastic polymer variant is mixed with the elastomeric component and in principle is combined with the thermoplastic terminal block of the above-mentioned unvulcanized block copolymer. The thermoplastic polymer variant preferably has an average molecular weight of about 1000-3000 and is present in the film composition in an amount of about 80-200 parts by weight per 100 parts by weight of the elastomeric component. The preferred A ¹ -BA ² block copolymer is styrene or It has A block derived from styrene homologue, ie polymerized or copolymerized, and B block derived from lower alkene such as ethylene and butylene from conjugated diene such as isoprene or butadiene. Small amounts of other monomers may also be incorporated into the block copolymer. Each block A may have an average molecular weight in the range of at least about 6000, preferably about 8000-3000, and the block A constituent is about 5-50% by weight of the block copolymer, preferably about 10-30 Constitute weight percent.

The average molecular weight of the B block for preparing the linear A ¹ -BA ² block copolymer is in the range of about 45000-180 000, and the average molecular weight of the linear copolymer itself is preferably in the range of about 75000-200000.

The average molecular weight of the radial A ¹ -BA ² block copolymer is in the range of about 125000-400000 as possible. The term ″ linear block copolymer ″ (or copolymers) includes not only branched A ¹ -B -A ² copolymers but also branched A ¹ -BA ² copolymers.

Useful radial A ¹ -BA ² copolymer in the elastomer prepared for the diaper of the present invention water may be in the form described in the patent, issued, etc. U.S. Patent No. 3,281,383 as a material rinseuki call, and the next match to the general formula (ABn ^x) where A is a thermoplastic block polymerized from styrene or styrene homologue, B is an elastomer block derived from conjugated diene or lower alkene as described above, and X is about 2-4 as described in Patent No. 3,281,383 It may have a higher function as described in the article under the heading `` New rubber is in the position of a star '' or as listed on page 35 of the `` Chemical Week '' magazine, issued June 11, 1974. Organic or inorganic linkage molecules.

As used above, ″ n '″ has a value consistent with the function of X.

Preferred elastomers are highly thermoplastic and elastomeric, but differ from rubbers that exhibit relatively sensitive melting points and are capable of thermoforming. The elastomer can also form permanent thermal bonding at relatively low thermal bonding temperatures, generally at temperatures not exceeding about 350 ° F., for substrates such as nonwovens or the like. This elastomer is very flexible, extensible and soft, and typically exhibits about 1 or less Gurley stiffness at 1 mil film thickness.

Particularly suitable elastomers for disposable diapers can be made from a combination of thermoplastic rubber and amorphous polypropylene. The thermoplastic rubber used for such bonding is a block copolymer having a block of polybutadiene or polyisoprene and a polystyrene block.

Criticisms re-writing these materials include the structure and properties of block copolymers and the present and future potentials of polyphase polymers, written by SL Agabal in Polymer Part 17, p938-956, issued in November 1976. There is this.

Two representative types of thermoplastic rubbers useful in these combinations are ″ stars ″ with 4-20 arms connected in the co-center with a linear block copolymer (ABA) having a middle block of polybutadiene or polyisoprene and a final block of polystyrene. Or ″ radial ″ block copolymers.

Each arm is one A-B block copolymer, the inner part of which is polybutadiene or polyisoprene and the outer part of which is polystyrene. Mainly to improve processability, the material to be added or bonded to the thermoplastic rubber while maintaining the inherent rubbery properties of the rubber is amorphous polypropylene. Amorphous polypropylene is a known material. It is essentially an atactic polypropylene having an isotic content of not more than about 20 weight percent, and preferably a content not exceeding 10 weight percent.

Amorphous polypropylene is used in an amount sufficient to improve the processability of the thermoplastic rubber when extruding a thin film or sheet. The exact minimum amount of amorphous polypropylene to be used varies somewhat from case to case, but about 10% by weight, based on weight or rubber plastics amorphous polypropylene, is moderate and in some cases may be as low as about 5% by weight. The upper limit of polypropylene will also vary from case to case depending on the nature of the components and the intended use of the product. By the same criteria, the inherent rubbery elastomer properties are greatly reduced at a ratio of about 35 weight percent or more.

This phenomenon may be acceptable for some uses but not for others. Therefore, the upper limit of amorphous polypropylene should be the upper limit at which the product retains the rubbery elastomeric characteristics considerably. Other conventional materials used in conventional amounts may be used in the mixture for their known purposes. Such materials are pigments, anti-convex, stabilizers, antioxidants, ultraviolet stabilizers, bonding aids, and the like.

In one embodiment of the disposable diaper of the present invention, an elastic body is a body which has contracted to this body by adding heat or other forms of energy to the body, causing elastic properties. Part of this elastic body may be treated to have elastic means so that other parts are not processed.

The heat shrinkable film which may be used as an elastic body in the disposable diaper of the present invention may be a polyolefin film that is rotationally deformed to a certain degree and has elasticity when thermally contracted. A preferred technique for modifying polyethylene films to have usually heat shrink elastic properties is a method of irradiation as suggested in British Patent 866,820. Also useful as heat-shrinkable elastomers include copolymers of ethylene and vinyl acetate, copolymers of ethylene and ethyl acrylate, and the like. Methods for forming such copolymers are known and specific methods for forming such materials are described in US Pat. Nos. 2,200,429 and 2,953,551. After the copolymer is formed and made into a film, appropriate modifications as described in British Patent 866,820, described above, are made.

The pore elastomers useful in the present invention can also be made from other materials such as natural rubber, synthetic rubber and the like. The elastic body can be made into a film with intermittent longitudinal sections made of a mesh, separated into parts that are not mesh. The film can be cut to the required width and sandwiched between the backing sheet and the front sheet of the diaper.

Extensively, the elastomer is made from a material having a stretchability of 20-1000%, preferably about 50-500%, and a recoverability in the range of 20-100%, preferably 70-100%. can do. 30-2000 g of force must be applied to increase this material by 100%. The important thing to remember is that when this material is put into the final product, this quality has elasticity as defined above, so it must function as an elastic means in the final product. For example, in the leg band section of a diaper, this elastomer should have a recovery of 90% or more in a very short period of time, suitably at the same time, and also a relatively small amount of force to stretch the leg band section to its original length. Should be needed. This force should be less than 200g and can be as low as 20g. The pore elastic body may be bonded by applying an adhesive to the supporting layer and placing the pore elastic body on the adhesive.

The front layer is placed on the pore elastic body and pressurized using a roll to allow the adhesive to pass through the opening of the bielastic body to bond at least the front layer and the backing layer together. Another technique is to apply an adhesive on one or both sides of the elastic body and place the supporting and front parts on opposite sides and press them together so that they can adhere.

When the front part and the supporting part are bonded together through the opening of the elastic body, the front part and the supporting part need not be bonded together outside the elastic body. In fact, when the front part and the backing part are not bonded to each other on the elastic bar side, the edge of the diaper has a soft and pleasant wrinkle effect along the edge. So far, only the rectangular elastic body has been mentioned, but the elastic body can have the required shape according to the shape required for the final product.

The disposable diaper 140 shown in FIG. 11 has an elongate absorbent sock 141, a moisture impermeable backing layer 142, and a moisture permeable front layer 143. As shown in FIG. The diaper 140 includes lateral edges 144 and 145 having curved mesh elastics 146 and 147 therein. The front and backing layers were cut as shown so that the diaper had a django shape. The front and backing layers may be adhered to each other via holes in the elastic body and may also be attached to the elastic body. Tape strings 148 and 149 are provided to secure the diaper to the waistline of the wearer.

FIG. 12 illustrates disposable explosives 160 that are intended for use in young children for training in urine and for use by children or adults who are unable to control urine. The undergarment has a front portion 161 and a back portion 162 and a crotch portion 163 composed of a liquid absorbent intermediate plate 164 positioned between the outer layer 165 and the moisture permeable inner layer 166. have.

The waistband of the underwear may be tightened with a mesh stretchable member 167 located between the ends of the inner and outer layers at the back and optionally positioned between the ends of the inner and outer layers at the front. The underwear may also have a mesh-like elastic body 168 lying between the inner and outer layers at the side edges of the crotch region.

FIG. 13 shows the disposable underwear 160 of FIG. 12 in a form in which the user is wearing. Both side edge portions 169 and 170 of the front portion are joined to corresponding edge portions 171 and 172 of the rear portion, respectively, to form a leg configuration 174 that is formed by itself with the waist portion 173.

Several different front layer materials may be used in disposable underwear. For example, this front part is mostly composed of cheap, short cellulose fibers, such as wood pulp or rough cotton, of 75% to 98%, as described in US Pat. No. 3,663,348 to Liloia et al. It may also be a nonwoven made from the fiber mixture that is made up.

Suitable nonwoven frontal materials for the disposable underwear of the present invention may have a woven bag and a density of less than 0.15 g / cc, generally in the range of about 0.05 to 0.1 g / cc, in the range of about 0.5 to 5 ounces per square yard. have. The dry strength of a woven front sheet weighing approximately 21.5 ounces per square yard is at least 0.15 pounds per inch wide in the machine operating direction and at least 0.1 pounds per inch wide in the transverse direction.

Such woven fabrics have good stretchability and are characterized by noble, soft and sagging properties. The front face may also be made from woven fabrics having holes made according to the assigned US patents 2,862,251 and 3,081,514, 3,081,515 and the like. In addition, the front face can also be made from other woven fabrics, such as those disclosed in U.S. Patent No. 3,485,706 to Evans.

These fronts may be made of natural fibers, synthetic fibers or blends thereof. The typical front section, made of polyester fiber, weighs about 0.75 ounces per square yard.

The front part may have the same dimensions as the supporting part and may have the same limits, and on the other hand, the front part may be wider than the supporting part so that the front part may be folded inward, and the front part and the supporting part may have the same edge (see US Patent No. 3,612,055). 3).

In the latter case, the elastic body may be fixed on the front fold folded inward. In addition, the front part may be made of a holeless material such as an isotropic nonwoven fabric, or may be made of perforated polyolefin or polyester film having the required moisture permeability.

All of the above-mentioned fronts should be somewhat hydrophobic so that the materials can slow the permeability in the front.

Moisture absorbent batts or valves of the required type smaller than the front and backing portions may be prepared according to the description of US Pat. No. 3,612,055 to Mesek et al.

The support material suitable for disposable underwear in the present invention may be opaque polyolefin, for example, 0.001 inch thick polyethylene. Another material suitable for this purpose is polyethylene, terephthalate, having a thickness of about 0.005 inches.

In use, the disposable diaper is spread on a single plane and the baby is put on it. The diaper end on which the waist rests is the side with the filling strap, the opposite end of which extends downward through the baby crotch. Next, the unfolded end of the diaper is raised through the baby's crotch to cover the pubic area and fold it so that it is located in the pressure portion of the baby's waist.

After that, the edge of the diaper end that covers the abdomen to cover the abdomen as much as possible below the edge of the baby's body is brought to overlap with the first corner, so that the diaper tightly surrounds the baby's waist and fits the diaper to the baby.

At this time, the adhesive tape attachment is prepared for use, and the tape is fixed in the desired position by simply touching and pressing on the tape. In some cases, it may be desirable to provide a secondary attachment that can be used directly above the thigh of the baby and below the normal attachment to secure the diaper in a better fit.

The foregoing description is for the purpose of description and should not be construed as limiting the invention. Other changes or modifications are possible without departing from the spirit or scope of the invention.

Claims (1)

A primary layer substrate and a secondary layer substrate formed of a flexible tightenable material and located adjacent to each other; It is composed of an elastic body which connects several elastic materials and forms a hole therebetween, so as to be positioned in the middle of the both sides of the substrate, and to fix the secondary layer and the primary layer through at least a part of the holes, and to narrow the body to a specific part of the body. Laminate used.

Images