JP5052428B2 - Telescopic sheet - Google Patents

Description

  The present invention relates to a stretchable sheet formed by combining an elastic filament and a stretchable non-stretchable sheet.

  For example, a technique described in Patent Document 1 is known as a conventional technique related to a stretchable sheet formed by combining an elastic fiber and a nonwoven fabric. The stretch sheet described in the same document is a nonwoven fabric having an elongation of 100% or more in at least one direction, and a stretchability of 200% or more continuously arranged in a spiral on the nonwoven fabric and bonded to the nonwoven fabric. The rubber strand which has. This stretchable sheet has high stretchability in the width direction (CD) when the sheet is manufactured. However, the stretchability in the flow direction (MD) is inferior in the width direction.

  The present applicant has also previously proposed a stretchable sheet formed by combining elastic fibers and a nonwoven fabric (see Patent Document 2). In the stretchable sheet described in the same document, a first web made of non-elastic fibers and a second web made of elastic fibers are superposed, and the hot air treatment is performed on these webs in a state where the webs are not integrated therewith. The fiber sheet is heat-sealed to obtain a fiber sheet, the fiber sheet is stretched in the flow width direction, and then stretched to release, thereby providing stretchability in the width direction. This stretchable sheet also has high stretchability in the width direction (CD) like the stretchable sheet described in Patent Document 1, but the stretchability in the flow direction (MD) greatly exceeds the width direction. It is not a thing.

  Patent Document 3 includes a liquid-permeable inner sheet, a liquid-impervious outer sheet, and a liquid-absorbent core interposed between the two sheets. The front waist area, the rear waist area, and both A disposable diaper is described having a side waistline region located between the regions. In this diaper, a part of the side waistline region is stretchable in the waistline direction and has a non-stretchable breathable nonwoven fabric, and elastic stretchability in the waistline direction, the nonwoven fabric On the other hand, it is composed of a plurality of elastic materials that are continuous in the waist circumference direction (stretching direction) and intermittently applied in the vertical direction (non-stretching direction) of the diaper. The elastic material is made of an elastic stretchable hot melt adhesive and is applied to the nonwoven fabric in a non-stretched state. The side waist region of the diaper is not stretchable in a direction perpendicular to the stretch direction.

  Patent Document 4 describes an elastic laminate that is elastically extensible in at least one direction. This elastic laminate is composed of a first nonwoven fabric layer 122, a second nonwoven fabric layer 126, and an elastomer layer 124 located between both nonwoven fabric layers as described in FIG. The elastomer layer 124 is composed of a scrim, a perforated film, an elastomer woven fabric, and a nonwoven fabric. FIG. 1 of this document describes that the elastomer layer 124 is composed of an elastomer scrim 130 including a plurality of first strands 125 and a plurality of second strands 127 orthogonal to each other. Since the strands 125 and 127 and the nonwoven fabric layers 122 and 126 are joined by heat and pressure from the outside, the strands 125 and 127 bite into the nonwoven fabric layers 122 and 126, and the nonwoven fabric layers 122 and 126 feel soft. Damaged. Since the strands 125 and 127 and the nonwoven fabric layers 122 and 126 are joined by the heat and pressure applied from the nonwoven fabric 122 or 126 side, the temperature on the outer nonwoven fabric side tends to be high at the time of adhesion, and the strand side The temperature tends to be lower than that of the nonwoven fabric. For this reason, when trying to obtain sufficient bonding strength, there is a problem that the nonwoven fabric is melted before the strands by heat and pressure and is formed into a film. Moreover, since it is necessary to melt the resin of the internal fiber in contact with the strand, there is a problem in that the temperature and pressure are increased and the texture is deteriorated. If a non-woven fabric with a high melting point is used, the non-woven fiber itself will not melt, but it will be difficult to fuse with the elastomer scrim, and it will be difficult to use a non-woven fabric with a soft texture and a relatively low melting point. .

JP 2002-205357 A JP 2007-191829 A JP-A-10-286279 Special table 2003-524534 gazette

  An object of the present invention is to provide a stretchable sheet having further improved stretchability compared to the above-described stretchable sheets of the prior art.

The present invention is an elastic sheet in which a large number of elastic filaments arranged so as to extend in one direction without crossing each other are joined between two stretchable non-elastic sheets,
Between the two sheets or on the outer surface of at least one of the two sheets, a stretchable adhesive is applied in a substantially continuous linear coating pattern,
The linear coating pattern provides a stretchable sheet having, in part, a linear portion extending in a direction substantially orthogonal to the extending direction of the elastic filament.

In the present invention, a large number of elastic filaments arranged to extend in one direction are sandwiched between two stretchable non-stretchable sheets, and between the two sheets or between the two sheets. An elastic adhesive is stretched on the outer surface of at least one of the sheets along a direction in which the elastic filament extends in a composite coated with a substantially continuous linear coating pattern. A method for producing an elastic sheet,
The linear coating pattern has, in part, a linear portion extending in a direction substantially orthogonal to the direction in which the elastic filament extends,
Expansion / contraction including a step of performing a biting / extending process for biting the complex between the tooth gap rolls in an elastic expression processing apparatus having a pair of tooth gap rolls in which teeth and roots are alternately formed in the circumferential direction. A method for manufacturing a sheet is provided.

  The stretchable sheet of the present invention exhibits stretchability in the direction in which the elastic filament extends and also exhibits stretchability in a direction perpendicular to the direction. That is, stretchability is expressed in the vertical and horizontal directions. In particular, it has high stretchability in the direction in which the elastic filament extends, and the balance of stretchability becomes good.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 shows a partially broken perspective view of the first embodiment of the stretchable sheet of the present invention. The stretchable sheet 10 of the present embodiment includes a first stretchable non-stretchable sheet (hereinafter also referred to as “first stretchable sheet”) 11 and a second stretchable non-stretchable sheet (hereinafter “ It is also referred to as a “second extensible sheet.”) It includes a total of two sheets and a large number of elastic filaments 13 sandwiched between the two sheets. Each elastic filament 13 is joined to the first and second extensible sheets 11 and 12. In the present invention, the term “elasticity” refers to the original length when the force is released from a state where it can be stretched and stretched 50% of the original length (which is 150% of the original length). The property of returning to a length of 113% or less.

  Both the sheet 11 and the sheet 12 are extensible. However, both the sheet 11 and the sheet 12 are non-stretchable. The sheet 11 and the sheet 12 can be extended in the same direction as the direction in which the elastic filament 13 extends. In the present application, the stretchable sheet means that the sheet can be stretched by a desired necessary external force (external force during stretching or external force due to human force on the use surface). For example, in the case of a non-woven fabric, stretchable is, for example, (a) when the constituent fiber itself of the non-woven fabric is stretched, and (b) even if the constituent fiber itself does not stretch, the fibers connected at the intersection are separated. Or when the three-dimensional structure formed by a plurality of fibers is structurally changed due to bonding of fibers, the constituent fibers are broken, the slack of the fibers is stretched, and the whole nonwoven fabric is stretched. Include. Taking film as an example, stretchable means (i) when the molecular chain of the constituent resin itself of the film is extended or shifted, and (b) when the constituent resin itself does not extend, the film Is partially broken (including slit opening, partial opening, particle-resin interfacial peeling, etc.), the slack of the film is stretched, or the whole film is stretched due to the deformation of the hole like an open film Including. Taking thin paper as an example, (b) when the constituent fibers themselves of the thin paper are stretched, and (b) even if the constituent fibers themselves are not stretched, the bound fibers are separated or the fibers are joined together. This includes a case where the three-dimensional structure formed by the fibers of the book is structurally changed, the constituent fibers are torn, or the slack of the fibers is stretched to stretch as a whole thin paper.

The stretchable sheet is preferably highly extensible. As a highly stretchable material, the stretchability of the stretchable non-stretchable sheet (including the stretchable sheet after stretching) is 30% at 100 cN / 50 mm strength. It is preferable to show the above. Further, it is preferably 70% or more. When the maximum strength is 100 cN / 50 mm or less, the maximum elongation when the maximum strength is shown is preferably 30% or more. Elongation is based on the length before stretching. Similarly, in the stretchable sheet 10 using a highly stretchable sheet, the stretched sheet (including those stretched by post-processing) has an elongation of 200 cN / 50 mm strength. The degree is preferably 30% or more. When the maximum strength is 200 cN / 50 mm or less, the maximum elongation when the maximum strength is shown is preferably 30% or more. Elongation is based on free tension when no tension is applied. A stretchable sheet exhibiting the above-described characteristics can be regarded as a highly stretchable non-stretchable sheet. These are determined in the same manner as the maximum intensity measurement.

  The maximum strength of the stretchable sheet that has been stretched in a highly stretchable stretchable sheet is preferably 5 cN / 50 mm or more, more preferably 100 cN / 50 mm or more, and even more preferably 500 cN / 50 mm or more. The maximum strength of the stretchable sheet 10 that has been stretched using a highly stretchable sheet is preferably 7 cN / 50 mm or more, more preferably 150 cN / 50 mm or more, and even more preferably 1000 cN / 50 mm or more.

  Further, in the present invention, non-stretchability means “when the force is released from a state where it can be stretched and stretched by 50% of the original length (which is 150% of the original length). In other words, it does not have the property of returning to a length of 113% or less of the original length.

  A further preferred embodiment of the present invention is that at least one of the extensible sheet sheets 11 and 12 is a highly extensible inelastic sheet. The reason for this is that, when stretched to the desired elongation, excessive breakage occurs, the strength is greatly reduced, and even if a sheet that cannot be used alone is used on one side, a highly stretchable sheet is used on the other. This is because the use of the stretchable sheet 10 provides excellent transportability during processing and durability on the product. In a more preferred embodiment of the present invention, a nonwoven fabric is used as the highly extensible sheet.

  The extensible sheets 11 and 12 may already be extensible in the state of the original fabric before being joined to the elastic filament 13. Alternatively, it is not stretchable in the state of the original fabric before being joined to the elastic filament 13, but is processed so as to be stretchable after being joined to the elastic filament 13, and becomes stretchable. Also good. Specific methods for making the extensible sheets 11 and 12 extensible (also referred to as “elastic development treatment” in the present specification) include heat treatment, inter-roll stretching, biting and stretching by tooth spaces and gears, Examples include tensile stretching with a tenter. In view of a preferable manufacturing method of the stretchable sheet 10 to be described later, the sheets 11 and 12 are improved in terms of transportability of the sheets 11 and 12 when the elastic filament 13 is fused to the extensible sheets 11 and 12. It is preferably not stretchable in the original fabric state. Moreover, generally speaking, the extensible sheets 11 and 12 do not have stretchability in both the original fabric state and the state after being joined to the elastic filament 13.

  Each elastic filament 13 is substantially continuous over the entire length of the stretchable sheet 10. The elastic filament 13 contains an elastic resin. The elastic filaments 13 are arranged so as to extend in one direction without crossing each other. However, the elastic filaments 13 are allowed to cross unintentionally due to inevitable fluctuations in the manufacturing conditions of the stretchable sheet 10. Each elastic filament 13 may extend linearly as long as it does not cross each other, or may extend while meandering.

  The fact that the filaments do not cross each other means that there are few intersections. When there is an intersection point, it means that there are a plurality of fibers between the intersection points. Usually, however, it is rare that the lengths of fibers existing between the intersection points coincide with each other industrially. If stretching is performed while the lengths of the fibers existing between the intersections are different, stress is applied only to the shorter fibers contained between the intersections. However, many fibers are not involved in elongation. When compared with fibers of the same weight, the shrinkage force becomes smaller as the number of fiber intersections increases. Therefore, cost is wasted. Considering expansion and contraction only in the vertical direction, if there are fibers in the horizontal direction like a net, the fibers in the horizontal direction are not only useless, but the intersections mentioned above occur, and the fibers in the vertical direction are also used in the same way. The part will occur.

  The direction in which the elastic filament 13 extends may coincide with the flow direction when the extensible sheets 11 and 12 are manufactured, or may be orthogonal to the flow direction when the sheets 11 and 12 are manufactured. When the stretchable sheet 10 is manufactured according to a preferable manufacturing method described later, the extending direction of the elastic filament 13 coincides with the flow direction at the time of manufacturing the extensible sheets 11 and 12.

  The elastic filament 13 is joined to the extensible sheets 11 and 12 in a substantially non-extended state. The extensible sheets 11 and 12 are non-stretchable and extensible. Since the elastic filament 13 is joined to the extensible sheets 11 and 12 in a state where the elastic filament 13 is not stretched, the stretchable sheet 10 of the present embodiment has an advantage that the stretchability does not decrease and the stretchability is not easily lowered. is there. Further, for example, when the elastic filament 13 is stretched twice and bonded to the extensible sheets 11 and 12, if it is temporarily returned to 1.3 times the initial value, it will be stretched only 1.54 times from this state. I can't. However, when pasting is performed in a non-stretched state, the initial origin when the stretchable sheet is stretched is different, so that the stretchable sheets 11 and 12 can be stretched or the elastic filament 13 can be stretched to the maximum elongation. There is an advantage that it can be extended.

  There is the following advantage in joining the elastic filament 13 to the extensible sheets 11 and 12 in a state where the elastic filament 13 is not elongated. The elastic sheet 10 of the present embodiment, for example, joins the substantially non-stretched elastic filament 13 to the non-stretched sheets 11 and 12 to form a take-up raw fabric (at this time, the elastic filament 13 is joined to the elastic sheet 13). Sheet 11 and 12 is non-stretchable), and this unstretched sheet is drawn out and stretched in another process (for example, tooth gap stretching) to make the unstretched sheets 11 and 12 into stretchable sheets. Manufactured. In the state of the original fabric, the original fabric is non-stretchable and non-stretchable, so that no external force acts on the elastic filament 13. As a result, there is an advantage that even if the original fabric is stored for a long period of time, relaxation due to elongation does not occur.

  The elastic filament 13 can be a thread-like synthetic rubber thread or natural rubber. Alternatively, it may be obtained by dry spinning (melt spinning) or wet spinning. Among these, in view of a suitable manufacturing method to be described later, the elastic filament 13 is preferably obtained by direct melt spinning without temporarily winding or storing the elastic filament 13.

  The elastic filament 13 is preferably obtained by stretching a molten resin discharged from a nozzle on a spinning line. By stretching, the polymer constituting the elastic filament 13 is molecularly oriented in the length direction of the elastic filament 13, so that the going / returning ratio at the time of 50% elongation, which will be described later, is increased and the hysteresis loss is reduced. Further, a thin elastic filament can be obtained by stretching. From this point of view, the elastic filament 13 is preferably stretched 1.1 to 400 times, particularly 4 to 100 times.

  In particular, the elastic filament 13 is preferably formed by being stretched in a state where the elastic resin is melted or softened. This makes it possible to obtain a sufficiently thin filament, and the texture is improved for reasons described later. Further, the elastic filament 13 is stretched in a state where the elastic resin is melted or softened, so that the elastic filament 13 which has become normal temperature after being bonded to the extensible sheets 11 and 12 does not show a force to shrink, It becomes the same state as having joined to the extensible sheets 11 and 12 in a non-extendable state. Specific operations for stretching in the present embodiment are as follows: (a) A resin as a raw material of the elastic filament 13 is melt-spun to obtain an unstretched yarn, and the elastic filament of the unstretched yarn is heated again to soften the temperature. (B) Operation for stretching in a state higher than (hard segment glass transition temperature Tg), and (b) operation for directly stretching a molten fiber obtained by melt spinning a resin as a raw material of the elastic filament 13 . When the stretchable sheet 10 is manufactured according to a preferable manufacturing method described later, the elastic filament 13 is obtained by directly stretching a molten fiber obtained by melt spinning.

  The elastic filament 13 obtained by drawing after spinning preferably has a diameter of 10 to 700 μm, particularly 10 to 300 μm, and particularly 20 to 160. This range is determined in consideration of the texture of the stretchable sheet 10 and the productivity of the elastic filament 13. Specifically, if the diameter of the elastic filament 13 is too large, a step due to the elastic filament 13 is easily perceived when the elastic sheet 10 is touched. This step acts negatively on the texture of the stretchable sheet 10. From this point of view, it is preferable that the elastic filament 13 has a smaller diameter because only the texture of the extensible sheets 11 and 12 is easily perceived. Further, the elastic filament 13 is preferably thin in order to reduce the light transmittance of the extensible sheets 11 and 12 so as to provide a so-called body fluid color hiding performance. Furthermore, in the elastic expression processing by the tooth space roll described later, the diameter of the elastic filament 13 is equal to or less than the tooth-to-tooth clearance between the tooth space rolls (preferred clearance is to increase the endurance of the tooth and the draw ratio by the amount of biting. Since the clearance is reduced at a higher point and is 250 μm or less, more preferably 200 μm or less, the elastic filament is less likely to be damaged (cracked or cut) during stretching. The ratio between the diameter of the elastic filament and the clearance is preferably 0.2 to 1, and more preferably 0.2 to 0.5. However, the smaller the elastic filament 13 is, the less easy it is to manufacture. Considering these, the diameter of the elastic filament 13 is preferably within the above-mentioned range.

  From the viewpoint of preventing the above-described step from being generated, the ratio of the diameter of the elastic filament 13 in the thickness direction of the elastic filament 13 to the thickness of the elastic sheet 10 is preferably 1 to 30%, particularly preferably 5 to 12%. .

  The elastic filament 13 may have a circular cross section, but in some cases may have an elliptical or flat cross section. For example, when the stretchable sheet 10 is manufactured according to the manufacturing method described later, the cross section of the elastic filament 13 tends to be flat. In this case, in the stretchable sheet 10, the elastic filament 13 has a flat major axis substantially in the same direction as the plane direction of the stretchable sheet 10 and a short axis substantially in the same direction as the thickness direction of the stretchable sheet 10. It is preferable that they are arranged as described above.

  When the cross section of the elastic filament 13 is flat, the ratio of long axis / short axis (average flatness ratio) is 1.0 to 7.0, particularly 1.1 to 3.0. This is preferable from the viewpoint that the bonding strength between the filament 13 and the constituent materials of the sheets 11 and 12 and the hiding performance of the stretchable sheet 10 are increased. The elastic filaments 13 having a flat cross section are arranged so that the major axis direction thereof substantially coincides with the plane direction of the stretchable sheet 10. In addition, when the cross section of the elastic filament 13 is flat, the diameter of the elastic filament 13 means what averaged the major axis diameter and the minor axis diameter. The major axis in the elastic filament 13 having a flat shape refers to the length of the longest transverse line on the outer periphery of the elastic filament 13 extracted by microscopic observation. The short axis in the elastic filament 13 refers to the length of the short side when a rectangle having two sides parallel to the long axis determined as described above and circumscribing the outer periphery is drawn. These are measured with respect to five arbitrary elastic filaments, and the average flatness is defined as the average flatness, and the average diameter is defined as the diameter of the elastic filament.

  The elastic filament 13 is also preferably colored in a color different from the color of the extensible sheets 11 and 12. As a result, the elastic filament 13 can be seen through the sheet 11 and / or the sheet 12, and the design effect that the stretchable sheet 10 exhibits a striped pattern is exhibited. Such an effect becomes more remarkable particularly when the thickness and basis weight of the extensible sheets 11 and 12 are within the ranges described below.

  From the viewpoints of the stretchable sheet 10 exhibiting sufficient stretchability, the fabric-like texture, and the above-described design effects as necessary, the pitch of the adjacent elastic filaments 13 (adjacent The distance between the elastic filaments 13) is preferably 0.1 to 5 mm, particularly preferably 0.4 to 1 mm, provided that the diameter of the elastic filament 13 is in the above-described range.

  The elastic filament 13 is preferably bonded to the extensible sheets 11 and 12 over its entire length. Here, “joined over the entire length” means that all the portions (extension fibers in the case of nonwoven fabric) of the extensible sheets 11 and 12 that are in contact with the elastic filament 13 are the elastic filament 13. The elastic filament 13 and the extensible sheets 11 and 12 are bonded in such a manner that there is no intentionally formed non-bonded portion in the elastic filament 13. Say. Since the elastic filament 13 is bonded to the extensible sheets 11 and 12 over the entire length, the bonding force between the elastic strand 13 and the extensible sheets 11 and 12 can be sufficiently increased. As a result, even if the stretchable sheet 10 is stretched, the elastic filament 13 is difficult to peel from the extensible sheets 11 and 12. If the elastic filament 13 is peeled off from the extensible sheets 11 and 12, in the natural state (relaxed state), floating occurs between the elastic filament 13 and the extensible sheets 11 and 12, and the elastic sheet 10 is wrinkled. It becomes easy to generate | occur | produce and it lacks the sense of unity as the elastic sheet 10 whole.

  As a mode of joining the elastic filament 13 and the extensible sheets 11 and 12, for example, fusion is mentioned. When the stretchable sheet 10 is manufactured according to a suitable manufacturing method described later, the elastic filament 13 is bonded to the extensible sheets 11 and 12 by fusion bonding. The fusion includes both a state in which the elastic filament 13 and the extensible sheets 11 and 12 are melted and bonded to each other, or a state in which either one is melted and the other bites into and adheres. According to this method, excessive heat is not applied to the extensible sheets 11 and 12, and the elastic filaments 13 are fused to the extensible sheets 11 and 12 before the elastic filaments 13 obtained by melt spinning are solidified. Therefore, only the site | part which exists around the elastic filament 13 among the extensible sheets 11 and 12 joins with the elastic filament 13, and the site | part in the position away from it has the texture of the extensible sheets 11 and 12. Since it is maintained as such, there is an advantage that the texture of the stretchable sheet 10 is kept good. In this case, before joining the extensible sheets 11 and 12 and the elastic filaments 13, an adhesive can be applied as an auxiliary joining means. Alternatively, after the extensible sheets 11 and 12 and the elastic filament 13 are joined, heat treatment (steam jet, heat embossing) or the like can be performed as an auxiliary joining means. However, these auxiliary joining means may damage the texture of the resulting stretchable sheet 10 or damage the elastic filament 13. Therefore, it is preferable to fuse the elastic filament 13 to the extensible sheets 11 and 12 with the heat of fusion.

  An adhesive 30 is applied between the two extensible sheets 11 and 12. The adhesive 30 has elastic stretchability. The adhesive 30 is used for the purpose of joining the two extensible sheets 11 and 12. The adhesive 30 is used for the purpose of joining the elastic filament 13 and the extensible sheets 11 and 12. Further, the adhesive 30 is used for the purpose of imparting stretchability to the stretchable sheet 30. The stretchability in this case is stretchability in a direction orthogonal to the direction in which the elastic filament 13 extends, as will be described later.

  The adhesive 30 is coated with a linear coating pattern. By setting it as a linear coating pattern, it can join, without impairing the texture etc. which the extensible sheets 11 and 12 have originally. The linear shape is a fiber shape, a thread shape, or a belt shape, and may be a network in which the adhesive 30 is attached to the fiber. This coating pattern is substantially continuous. “Substantially continuous” means that when the adhesive 30 is applied in the manufacturing process of the stretchable sheet 10, the coating pattern is unintentionally interrupted due to unavoidable fluctuations in the coating apparatus. It is a purpose to allow. The coating pattern of the adhesive 30 in the present embodiment is a spiral pattern extending in the same direction as the direction in which the elastic filament 13 extends. A large number of spiral patterns are formed in a row along a direction orthogonal to the direction in which the elastic filament 13 extends. Adjacent spiral patterns are partially overlapped. By adopting such a coating pattern, it is possible to perform bonding more reliably without impairing the texture or the like inherent to the extensible sheets 11 and 12. In the following description, the direction in which the elastic filament 13 extends is referred to as the MD direction for convenience, and the direction orthogonal thereto is referred to as the CD direction.

  The spiral coating pattern of the adhesive 30 has a linear portion 31 extending in the CD direction at a part thereof. There are two locations 31 in the spiral of one turn. As described above, the adhesive 30 has elastic stretchability, and because the spiral coating pattern of the adhesive 30 has a portion 31 extending in the CD direction, the stretchable sheet 10 is made of MD. In addition to exhibiting elasticity in the direction, it also exhibits elasticity in the CD direction. However, when the stretchability due to the elastic filament 13 and the stretchability due to the adhesive 30 are compared, the stretchability due to the elastic filament 13 is large, so the stretchable sheet 10 of this embodiment is high in the MD direction. It is particularly useful for applications where return strength is required.

  When paying attention to one spiral row, the spiral row is preferably coated so as to straddle two or more elastic filaments 13. By applying in this way, a higher return strength can be obtained in the CD direction with a smaller amount of adhesive 30. Further, when focusing on one spiral row, adjacent spiral rows may be applied so that the portions 31 extending in the CD direction do not overlap each other, or may be applied so as to overlap each other. From the viewpoint of obtaining a higher return strength in the CD direction, in one spiral row and a spiral row adjacent thereto, portions 31 extending in the CD direction overlap with each other, and a linear pattern that apparently extends in the CD direction is MD It is preferable that many are formed along the direction.

The coating amount of the adhesive 30 is 0.5 to 60 g / m ² , particularly ² to 10 g / m ² , and the stretchable sheet 11, It is preferable from the point that joining can be performed more reliably without impairing the texture etc. that 12 originally has.

  As described above, the stretchable sheet 10 can be stretched in the MD direction and the CD direction. The stretchability of the stretchable sheet 10 is expressed due to the elasticity of the elastic filament 13 and the adhesive 30. When the stretchable sheet 10 is stretched in the same direction as the MD direction or the CD direction, the elastic filament 13 or the adhesive 30 and the extensible sheets 11 and 12 are stretched. When the stretching of the stretchable sheet 10 is released, the elastic filament 13 or the adhesive 30 contracts, and the extensible sheets 11 and 12 return to the state before stretching as the contraction occurs. The degree of stretchability is more remarkable in the MD direction than in the CD direction.

  Regarding the stretchability of the stretchable sheet 10, the stretchable sheet 10 is stretched 50% along the MD direction, and a load A (hereinafter also referred to as 25% return strength) when returned from that state by 25%, It is preferable that the ratio (A / B) of the load B (hereinafter also referred to as 25% strength) when it is stretched 25% along the line is 50% or more, particularly 65% or more. The value of the return strength ratio (A1 / (A1 + A2)) in the direction 2 perpendicular to the direction 1 in which the elastic filament 13 extends is preferably 70% or more, particularly 90% or more. By doing so, it is possible to achieve both prevention of width shrinkage and expansion and contraction in the vertical and horizontal directions. Furthermore, the ratio (the former / the latter) of the ratio (A / B) value measured in the MD direction and the ratio (A / B) value measured in the CD direction is 1.0 to 3.0, particularly It is preferable that it is 1.5-2.5.

  The stretchable sheet 10 preferably has a ratio (C1 / C2) of the load C1 when stretched 50% along the MD direction and the load C2 when stretched 50% along the CD direction (C1 / C2), preferably 0.1-2. More preferably, it is 0.2-1. These can be adjusted by the draw ratio in the elastic expression process of the composite 19 described later. The ratio (E1 / E2) between the elongation E1 when the load is 200 cN / 50 mm when stretched along the MD direction and the elongation E2 when the load is 200 cN / 50 mm when stretched in the CD direction is preferably 0.1. It is 5-20, More preferably, it is 1-10. That is, it is preferable to extend in the MD direction with low stress and high elongation and in the CD direction with high stress and low elongation. When the stretchable sheet 10 is used, for example, in the crotch part of an absorbent article, a material having a high elongation in the front-rear direction and a material having a low elongation in the orthogonal direction (width direction) are used. This is preferable because it can prevent twisting and slipping during wearing.

  The above A / B value is measured by the following method. The elastic sheet is cut out in a size of 200 mm in the direction of expansion and contraction and 50 mm in a direction perpendicular to the expansion / contraction direction to obtain a test piece. A test piece is attached to a tensile tester AG-1kNIS manufactured by Shimadzu Corporation at a distance between chucks of 150 mm. The test piece is stretched in the expansion / contraction direction at a speed of 300 mm / min. The load at the time of 50% elongation is recorded, and the value is taken as 50% strength. Subsequently, the test piece is stretched to 100% and then shrunk at the same speed in the return direction (shrinking direction) to be in a state stretched by 50%. Record the load at that time and give 50% return strength. The above measurement is performed in an environment of temperature 20 ± 2 ° C. and humidity 65 ± 5% RH.

  2A and 2B are longitudinal sectional views along the MD direction in the stretchable sheet 10 according to the embodiment of the present invention. The embodiment shown in FIGS. 2 (a) and 2 (b) is a form that remarkably develops when biting stretching is used in the elastic expression processing step in the manufacturing process of the stretchable sheet 10. Fig.2 (a) is a longitudinal cross-sectional view of the elastic sheet 10 in a natural state (relaxed state), and FIG.2 (b) is a longitudinal cross-sectional view of the elastic sheet 10 in an expansion | extension state. These drawings show the state of the stretchable sheet 10 when a nonwoven fabric is used as the extensible sheets 11 and 12. In the natural state, the elastic sheet 10 is alternately formed with minute convex portions and concave portions extending in the same direction (CD direction) on one surface and the other surface. At the position of the convex portion and the concave portion on one surface, the concave portion and the convex portion on the other surface are located. Specifically, it has a corrugated shape in which top portions 14 'corresponding to the convex portions and trough portions 14 "corresponding to the concave portions are alternately arranged. The top portions 14' and the trough portions 14" are connected via the ridge line portion 15 '. It is lined up. The thickness of the top portion 14 'and the valley portion 14 "is slightly smaller than the thickness of the ridge line portion 15', and is easier to transmit light than the ridge line portion 15 '. When the stretchable sheet 10 is viewed in plan view The top portion 14 ′, the ridge line portion 15 ′, and the valley portion 14 ″ extend in a direction orthogonal to the extending direction of the stretchable sheet 10. Therefore, in the stretchable sheet 10, in its natural state, a horizontal stripe pattern caused by the ridge portion 15 ′ that easily transmits light and the top portion 14 ′ and the valley portion 14 ″ that hardly transmit light appears slightly. The horizontal stripe pattern may become more conspicuous depending on conditions such as an elastic expression process described later.

  That is, as shown in FIG. 2B, in the stretchable stretchable sheet 10, the high basis weight portions 14 and the low basis weight portions 15 are alternately arranged along the MD direction. Each of the portions 14 and 15 extends in a strip shape in the CD direction. The high basis weight portions 14 and the low basis weight portions 15 are alternately arranged at a constant period. About the high basic weight part 14, what protrudes above the elastic sheet 10 and what protrudes below the elastic sheet 10 are arrange | positioned alternately. The high basis weight portion 14 protruding above the stretchable sheet 10 is derived from the top portion 14 ′ of the stretchable sheet 10 in the natural state shown in FIG. On the other hand, the high basis weight portion 14 projecting downward from the stretchable sheet 10 is derived from the valley portion 14 ″ in the stretchable sheet 10 in the natural state shown in FIG. 2A. 2 (a) is derived from the ridge line portion 15 'in the stretchable sheet 10 in the natural state shown in Fig. 2 (a) The high basis weight portion 14 and the low basis weight portion 15 emit light due to the difference in basis weight. As a result, the stretchable sheet 10 has a horizontal stripe pattern extending in the CD direction and has high design properties.In particular, as described above, the stretchable sheet 10 is formed on the elastic filament 13. Since the resulting striped pattern is also exhibited, the stretchable sheet 10 also exhibits a lattice-like pattern in which the striped pattern is combined with the striped pattern derived from the high basis weight portion 14 and the low basis weight portion 15. Becomes even higher.

  The high basis weight portion 14 has a larger basis weight and a larger thickness than the low basis weight portion 15. As a result, the high basis weight portion 14 and the low basis weight portion 15 differ in the degree of light transmission, and a striped pattern is exhibited due to the difference. Each high basis weight portion 14 is substantially equal in width to each other, and similarly, each low basis weight portion 15 is also substantially equal in width to each other.

The thickness of the high basis weight portion 14 is preferably 0.3 to 10 mm, particularly preferably 0.5 to 1 mm. The thickness of the low basis weight portion 15 is preferably 0.1 to 3 mm, particularly preferably 0.2 to 0.6 mm from the viewpoints of stretchability and air permeability. The thickness is measured by the following method after the stretchable sheet 10 is left unloaded for 2 days or more in an environment of 20 ± 2 ° C. and 65 ± 5% RH. First, the stretchable sheet 10 is sandwiched between flat plates with a load of 0.5 cN / cm ^{2 in} a state where the stretchable sheet 10 is stretched 1.5 times. The cross section is observed with a microscope at a magnification of 50 to 200 times, and an average thickness is obtained in each field of view, and is obtained as an average value of the thicknesses of three fields of view. The high basic weight portion 14 and the low basic weight portion 15 are easily formed by manufacturing the stretchable sheet 10 according to the manufacturing method described later.

  Next, the constituent materials of the extensible sheets 11 and 12, the elastic filaments 13, and the adhesive 30 constituting the stretchable sheet 10 will be described. The extensible sheets 11 and 12 are made of a non-stretchable film material or fiber material. In the present embodiment, the extensible sheet 12 may be the same as the extensible sheet 11 described in detail below. In this case, the extensible sheet 12 can be the same or different from the extensible sheet 11. Therefore, regarding the extensible sheet 12, the explanation about the extensible sheet 11 described below will be replaced with the explanation of the extensible sheet 12. Here, the same type means sheets having the same manufacturing process, type of constituent resin, thickness, basis weight, and the like. When at least one of these is different, the sheets are different.

  As the extensible sheet 11, a film material or a fiber material (nonwoven fabric or paper) can be used as described above. In the case of using a fiber material, it is preferable to use a clogged material from the viewpoint of preventing leakage of the adhesive 30. The extensible sheet 11 may be substantially regularly broken or broken. By doing in this way, when the elastic sheet 10 is used, for example as a surface sheet of an absorbent article, it becomes possible to absorb water from the hole by this tear. Substantially regular breaks and breaks can be formed by post-processing after bonding by, for example, biting and stretching. Further, when the stretchable sheet 10 using thin paper as the extensible sheet 11 is applied to the absorbent body of the absorbent article, the tear or breakage serves as a water inlet and an absorbent article having a high absorption rate can be obtained.

  When the extensible sheet 11 is made of a film material, the film material is preferably water-impermeable or water-permeable. The film material is also preferably moisture permeable or moisture permeable. A particularly preferable film material is a non-water-permeable and moisture-permeable film (hereinafter also referred to as a non-stretchable moisture-permeable film). This non-stretchable moisture permeable film is obtained by, for example, melt-molding a resin composition obtained by kneading a material incompatible with the resin into a thermoplastic resin into a film shape, and the obtained film is uniaxial or biaxial. It is made porous by axial stretching. Examples of the thermoplastic resin that can be used include polyolefins such as polyethylene, polypropylene, and olefin copolymers. Examples of substances that are not compatible with thermoplastic resins include calcium carbonate, gypsum, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium sulfate, hydrated silicic acid, anhydrous silicic acid, soda ash, sodium chloride, sodium sulfate, and barium sulfate. Inorganic fillers such as talc, clay, various cements, volcanic ash, shirasu, titanium oxide, iron oxide and carbon black, various metal powders, other inorganic substances, and organic metal salts mainly composed of inorganic substances. Moreover, polymers such as thermosetting resins such as phenol resin, epoxy resin, and sodium polyacrylate, or resins having a melting temperature higher than the molding temperature of the thermoplastic resin are mentioned. These substances are desirably used as a granular material having an average particle diameter of 50 μm or less, preferably 0.05 to 30 μm, particularly about 0.1 to 5 μm. The blending ratio of the thermoplastic resin and the substance is preferably 50 to 400 parts by weight, more preferably 60 to 300 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

When the extensible sheet 11 is a film material having moisture permeability, the moisture permeability (measured at 30 ° C. and 90% RH according to JIS Z0208) is 0.4 to 6 g / (100 cm ² · hr), particularly It is preferably 0.8 to 4 g / (100 cm ² · hr). The water pressure resistance (JIS L1092) is preferably 0.5 m or more, particularly 2 m or more. Further, the sheet 11 made of a film material having a moisture permeability, on condition that the moisture permeability and water pressure resistance is in the range described above, a basis weight of 5 to 100 g / m ^2, in particular at 10 to 30 g / m ² Preferably there is.

  When the extensible sheet 11 is a highly extensible film, the original film for use in this film is preferably unstretched or low-stretched. Such an unstretched or low-stretched film is preferably stretched at a magnification of 1.0 to 3 times, more preferably 1.0 to 1.5 times. Thereby, the extensible sheet 11 having high strength and high elongation can be obtained. Moreover, it becomes difficult to generate | occur | produce a tear etc. at the time of extending | stretching by post-processing. In the case of a moisture permeable film, a pinhole is hardly generated and a highly permeable film is obtained.

  The extensible sheet 11 can also be a thin paper. As the thin paper, natural paper, synthetic paper, a mount used for an absorbent body of an absorbent article, and the like can be used. The stretchable sheet 10 when thin paper is used as the extensible sheet 11 is useful as an auxiliary agent for instantaneous absorption at the time of water absorption and as diffusion paper. As the thin paper, functional paper having effects such as deodorization and antibacterial can be used. When the extensible sheet 11 is a highly extensible thin paper, such a thin paper is preferably creped. In that case, the crepe rate is preferably 10% or more, more preferably 30% or more.

  The stretch sheet 11 can also be a nonwoven fabric. As the fibers constituting the nonwoven fabric, substantially inelastic fibers are used. Examples thereof include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the nonwoven fabric may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The nonwoven can be a continuous filament or short fiber nonwoven. In particular, from the viewpoint of making the stretchable sheet 10 thick and bulky, the nonwoven fabric is preferably a short fiber nonwoven fabric. When the stretchable sheet 10 is used as a member that comes into contact with the skin, a short fiber nonwoven fabric with good texture may be used on the skin contact side, and a high-strength continuous filament nonwoven fabric may be used on the opposite surface.

  The non-woven fabric is preferably composed of two or more components of a low melting point component and a high melting point component. In that case, the constituent fibers are joined at fiber intersections by at least thermal fusion of the low melting point components. As the core-sheath type composite fiber composed of two or more components of a low melting point component and a high melting point component, those having a core of high melting point PET, PP and a sheath of low melting point PET, PP, PE are preferable.

The thickness of the nonwoven fabric is preferably 0.05 to 5 mm, more preferably 0.1 to 1.0 mm, and still more preferably 0.15 to 0.5 mm. The thickness was measured by sandwiching the flat sheet between flat plates with a load of 0.5 cN / cm ² and observing the cross section of the stretchable sheet 10 with a microscope at a magnification of 50 to 200 times. It can obtain | require as an average value of thickness. The thickness of the entire stretchable sheet 10 is obtained by measuring the distance between the flat plates. The basis weight of the nonwoven fabric is preferably ³ to 100 g / m ² , particularly preferably 10 to 30 g / m ² , from the viewpoints of texture, thickness, and design properties.

  The extensible sheet 11 made of a nonwoven fabric is preferably made of substantially inelastic fibers from the viewpoints of texture, stickiness and the like. The proportion of inelastic fibers in the nonwoven fabric is preferably 70% by weight or more, particularly 90% by weight or more, and particularly preferably 100% by weight. Moreover, the substantially inelastic fiber may contain a small amount of elastic resin in the inelastic resin. In this case, the proportion of the inelastic resin is preferably 70% by weight or more, more preferably 90% by weight, and still more preferably 100% by weight.

  When the extensible sheet 11 made of a non-woven fabric is a highly extensible non-woven fabric, it is particularly preferable to use a non-elastic fiber whose fiber thickness is not uniform in the length direction (hereinafter referred to as this). Fiber is called indefinite fiber). That is, indefinite-diameter fibers have a large fiber cross-sectional area (diameter) and a small part when viewed along the length direction. In the indefinite fiber, the diameter (cross-sectional area) may continuously change from the smallest part to the largest part. Or the diameter (cross-sectional area) of the fiber may be changing in the substantially step shape like the necking phenomenon observed in the extending | stretching process of an undrawn yarn. An example of an inelastic fiber in which the fiber diameter (cross-sectional area) is changed in a substantially step shape is shown in FIG.

  The inelastic fiber is made from a fiber having a constant fiber diameter and a high elongation (for example, the maximum elongation of the fiber is 80 to 800%, particularly 120 to 650%). It is preferable at the point obtained. The elongation of the fiber conforms to JIS L-1015, based on the measurement environment temperature and humidity 20 ± 2 ° C., 65 ± 5% RH, tensile tester gripping distance 20 mm, tensile speed 20 mm / min. To do. In addition, when collecting fibers from an already manufactured non-woven fabric and measuring the elongation, when the gripping interval cannot be 20 mm, that is, when the length of the fiber to be measured is less than 20 mm, the gripping interval is set. Measure by setting to 10 mm or 5 mm.

  The high-stretch fiber is preferably a low-stretch inelastic fiber. When the stretchable sheet 10 of the present embodiment is manufactured using a low-stretched inelastic fiber as a raw material in accordance with the manufacturing method described later, the stretched low-stretched fiber is stretched in the elastic expression treatment, resulting in a thin portion of the fiber. An indefinite fiber is formed. As a result, in the elastic expression treatment of the stretchable sheet 10 of the present embodiment, the nonwoven fabric is changed into a form that is easily stretched structurally, but the entire nonwoven fabric structure is easily stretched by stretching the fibers, It becomes possible to minimize the breakage of the joining points between the amorphous fibers and the joining points of the extensible sheet 11 and the elastic filaments 13, and the strength of the stretchable sheet 10 is increased while maintaining the stretchability. can do. That is, the stretchable sheet 10 having both high elongation and high strength is obtained. Further, in the elastic expression treatment, the bonding between the indefinite fibers is less likely to be destroyed, which also has the effect of making the nonwoven fabric less likely to become fluffy. This is advantageous from the viewpoint of improving the appearance of the stretchable sheet 10 of the present embodiment.

  Furthermore, by using the low-stretched fiber as a raw material, the number (length) of thin fibers is substantially increased as compared to before fiber stretching. Thereby, the light impermeability of the stretchable sheet 10 of the present embodiment is improved.

  In addition, if the region where the indefinite fiber is densely present is periodically changing on the nonwoven fabric, the surface of the nonwoven fabric will be finely wavy and the touch will be good. There is also a positive effect. In this case, the period of change, that is, the distance between the thick part in the nonwoven fabric and the adjacent thick part is preferably 0.5 mm to 10 mm, particularly 2 to 5 mm. This period can be measured from microscopic observation of the nonwoven fabric. The diameter of the amorphous fiber is measured by the following procedures (1) to (5).

(1) The extensible sheet 11 is sampled from an area of 5 mm × 5 mm or more on the surface of the stretchable sheet 10. At this time, the sample may be collected by separating the extensible sheet 11 from the elastic filament 13 or the entire stretchable sheet 10 may be collected. (2) The collected sample is fixed to the SEM observation sample stage. At this time, in order to easily observe the sample, the sample may be fixed to the sample stage with a double-sided tape in a state where the sample is stretched to such an extent that the structure of the sample is not destroyed (until the nonwoven fabric can be loosened). The stretch amount at this time is, for example, approximately equal to or less than the stretching ratio at which the precursor of the stretchable sheet 10 is stretched in the stretching step when the step of producing the stretchable sheet 10 (elastic development treatment) is used.
(3) SEM observation is performed at a magnification of 200. The visual field area at one place is about 0.4 mm × 0.4 mm or more, and five places are observed.
(4) Fibers are extracted at random, and the diameter is measured in units of 0.1 μm at 20 or more locations every 10 μm in the fiber axis direction (fiber fusion points or broken parts are not included in the measurement. ). Four or more fibers are measured for each field, and a total of 20 fibers are measured for five fields.
(5) Extract the maximum diameter and the minimum diameter of each of the ten fibers from these values. When the difference between the maximum diameter and the minimum diameter of one fiber is 1 μm and the relationship between the position in the fiber axis direction and the change in diameter is graphed, a fiber having a maximum position or two or more minimum positions is called an amorphous fiber.

  From the viewpoint of making the above effects even more remarkable, the indefinite fiber is preferably 2 to 15 μm in thickness at the thinnest part, more preferably 5 to 12 μm, and preferably 10 to 10 at the thickest part. It is 40 μm, more preferably 12 to 30 μm. The difference between the maximum diameter and the minimum diameter of the indefinite fiber is preferably 3 μm or more, particularly 5 μm or more, and particularly preferably 10 μm or more. Moreover, the value of the fiber diameter ratio defined by “maximum fiber diameter / minimum fiber diameter” is preferably 1 to 15, more preferably 1.2 to 10, and 2 to 5. Even more preferred.

  The non-constant fiber preferably has an inter-fiber fusion point strength higher than the strength at 100% elongation of the non-constant fiber. Thereby, in the elastic expression processing step when manufacturing the elastic sheet 10, when the elastic sheet 10 before the elastic expression process is stretched and subjected to the elastic expression processing, the fibers of the extensible sheet 11 before the elastic expression process are fused. The point breakage is less likely to occur, and the strength of the elastic sheet 10 obtained through the elastic expression treatment process is less likely to be lower than the strength of the elastic sheet 10 before the elastic expression treatment. The fusion point strength is measured according to the description in paragraph [0040] of Japanese Patent Application Laid-Open No. 2004-218183 relating to the previous application of the present applicant. The strength at 100% elongation is measured using a tensile tester under conditions of a distance between chucks of 20 mm and a tensile speed of 20 mm / min.

  The low-stretched inelastic fibers described above include both fibers drawn at a low draw ratio after spinning and unstretched fibers, that is, unstretched fibers. As the low-stretched fiber, it is preferable to use a fiber having a high elongation of 80 to 800%, particularly 120 to 650% as described above. By using a low-stretched fiber having an elongation in this range, the fiber is successfully stretched by a stretching apparatus 22 shown in FIG. 4 to be described later, and an indefinite fiber is easily formed. The fiber diameter of the low-stretched fiber is preferably 10 to 35 μm, particularly preferably 12 to 30 μm.

  As described above, the non-constant diameter fiber is preferably made from a low-stretched fiber having a constant fiber diameter as a raw material. In this case, the low-stretched fiber may be a fiber made of a single raw material, or a composite fiber using two or more raw materials, such as a core-sheath type composite fiber or a side-by-side type composite fiber. Good. Considering the ease of joining the indefinite diameter fibers and the ease of joining the extensible sheet 11 and the elastic filament 13, it is preferable to use a composite fiber. In the case of the core-sheath type composite fiber, the core is preferably polyester (PET or PBT) or polypropylene (PP), and the sheath is preferably low melting point polyester (PET or PBT), polypropylene (PP) or polyethylene (PE). In particular, when these composite fibers are used, when the elastic filament 13 contains a polyolefin-based elastomer, it is preferable in that the thermal fusion between the elastic filament 13 and the constituent fibers of the extensible sheet 11 becomes strong and layer peeling does not easily occur.

  The non-constant diameter fiber may be a short fiber such as a staple fiber, or may be a long fiber such as a continuous filament. In view of a preferable method for manufacturing the stretchable sheet 10 described later, it is preferable to use short fibers. The indefinite fiber may be hydrophilic or water repellent.

  The extensible sheet 11 made of a non-woven fabric may be composed of only indefinite diameter fibers, or may contain other inelastic fibers having a constant diameter in addition to the indefinite diameter fibers. Other inelastic fibers include those mentioned above. When the non-woven fabric contains non-elastic fibers having other fixed diameters in addition to the non-constant diameter fibers, the blending amount of the other non-elastic fibers is preferably 1 to 30% by weight, particularly preferably 5 to 20% by weight. .

  As described above, the elastic filament 13 is made of, for example, an elastic resin such as a thermoplastic elastomer or rubber. In particular, when a thermoplastic elastomer is used as a raw material for the elastic resin, melt spinning using an extruder is possible in the same manner as a normal thermoplastic resin, and the filaments thus obtained are easy to heat-seal, It is suitable for the elastic sheet of this embodiment. Examples of the thermoplastic elastomer include SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), and SEPS (styrene-ethylene-propylene-styrene). And olefin elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene / butene / octene), polyester-based elastomers, and polyurethane-based elastomers. These can be used individually by 1 type or in combination of 2 or more types. A core-sheath type or side-by-side type composite fiber made of these resins can also be used. In particular, use of a styrene-based elastomer, an olefin-based elastomer, or a combination thereof is preferable in terms of moldability, elastic properties, and cost of the elastic filament 13.

  From the viewpoint of lowering the compatibility with the adhesive 30 described later, it is also preferable to use a crosslinked polyurethane yarn or a natural rubber yarn produced in advance as the elastic filament 13. In this case, the elastic filament 13 is fed from the take-up roll and bonded to the extensible sheets 11 and 12. In the lamination, the stretchable elastic filaments 13 are connected to the extensible sheets 11 and 12 in terms of obtaining a high return strength, obtaining a material with a good texture by increasing the thickness at the time of biting and stretching described later, and transportability. It is preferable to join. In this case, the insertion elongation rate of the elastic filament 13 is preferably 1.2 to 5.0 times. It is preferable to use a moisture-permeable film and thin paper as the extensible sheets 11 and 12 because a concavo-convex structure can be easily formed on the stretchable sheet 10.

  The elastic stretchable adhesive 30 is preferably composed of an elastic resin, a pressure-sensitive adhesive, a softening agent and the like, and contains 10 to 60% by weight of an elastic resin out of a solid content excluding a solvent. As such an adhesive, a hot-melt adhesive, a solvent-type adhesive, an emulsion-type adhesive, or the like can be used. As the elastic resin contained in the adhesive 30, the same elastic resin used for the elastic filament 13 can be used. For example, elastomers such as SBS, SIS, SEBS, and SEPS, ethylene copolymers such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, atactic polypropylene, isotactic polypropylene, propylene-1-butene Examples thereof include olefin resins such as copolymers, propylene-1-butene-ethylene copolymers, and ethylene-propylene rubber. The adhesive 30 is preferably one that does not melt, swell, or soften the elastic filament 13. Thereby, the fall of the expansion-contraction characteristic during the preservation | save of the elastic sheet 10 can be suppressed. From the viewpoint of lowering the compatibility, it is preferable to use different elastic resins for the elastic filament 13 and the adhesive 30. The adhesive 30 preferably has a low content of pressure-sensitive adhesive or softening agent.

  Next, the preferable manufacturing method of the elastic sheet 10 of this embodiment is demonstrated, referring FIG. In this manufacturing method, a large number of molten elastic filaments 13 spun from the spinning nozzle 16 are drawn and stretched at a predetermined speed, and the elastic filaments 13 do not cross each other before the elastic filaments 13 are solidified. The elastic filament 13 is fused to the extensible sheets 11 and 12 so as to be arranged in one direction, and then the composite 19 to which the elastic filament 13 is fused is elastically developed at least along the extending direction of the elastic filament 13. The composite 19 is treated to give stretchability. Before the elastic filament 13 is fused to the extensible sheets 11 and 12, the adhesive 30 is applied to the surface of the at least one extensible sheet 11 and 12 facing the elastic filament 13. By doing in this way, while the interlayer adhesiveness of the extensible sheet | seats 11 and 12 increases, the damage to the elastic filament 13 at the time of the biting extending | stretching mentioned later may be reduced by the adhesive agent 30.

  The spinning nozzle 16 is provided in the spinning head 17. The spinning head 17 is connected to an extruder. Resin can also be supplied to the spinning head 17 via a gear pump. The elastic resin melt-kneaded by the extruder is supplied to the spinning head 17. The spinning head 17 has a large number of spinning nozzles 16 arranged in a straight line. The spinning nozzle 16 is arranged along the width direction of the first and second nonwoven fabrics 11 and 12. The interval between the adjacent spinning nozzles 16 corresponds to the interval between the elastic filaments 13 in the target stretchable sheet 10. The spacing between adjacent spinning nozzles 16 can be 0.5-30 mm, in particular 1-5 mm. The spinning nozzle 16 is usually circular, and its diameter affects the diameter of the elastic filament 13 and the draw ratio. From this viewpoint, the diameter of the spinning nozzle 16 is preferably 0.1 to 2 mm, particularly preferably 0.2 to 0.6 mm. For the purpose of increasing the bonding strength with the extensible sheets 11 and 12, the purpose of increasing the spinnability of the elastic filament 13, and the purpose of improving the expansion / contraction characteristics of the expansion / contraction sheet 10, the elastic filament 13 is in a composite form (side-by-side, core sheath, Sea-island structure). Specifically, it is preferable to combine a PP elastomer resin and a styrene elastomer resin.

  In parallel with the spinning of the elastic filament 13, the adhesive 30 is applied to the surface facing the elastic filament 13 in at least one of the extensible sheets 11 and 12 using the coating device 40. In the embodiment shown in FIG. 4, an adhesive 30 is applied to the extensible sheet 11. The coating device 40 is installed on the upstream side of the joining portion between the extensible sheets 11 and 12 and the elastic filament 13. The coating pattern of the adhesive 30 by the coating apparatus 40 is spiral. As the coating device 40, a known hot melt coating device or printing device can be used. Specifically, coating, spiral, curtain, spray, omega, dulau eve, screen mesh, intermittent application of these, gravure printing, flexographic printing, and the like are used. Spiral coating and curtain coating are particularly preferable in terms of air permeability and stretchability.

  The spun elastic filaments 13 spun together join the extensible sheets 11 and 12 that are fed from the original fabric at the same speed, and are sandwiched between the sheets 11 and 12 and taken up at a predetermined speed. The take-up speed of the elastic filament 13 coincides with the feeding speed of both sheets 11 and 12. The take-up speed of the elastic filament 13 affects the diameter and the draw ratio of the elastic filament 13. The tension generated in the elastic filament 13 by stretching prevents the elastic filament 13 from being disturbed due to wind or static electricity when the elastic filament 13 is bonded to the extensible sheets 11 and 12. Thereby, the elastic filaments can be arranged in one direction without crossing each other. From these viewpoints, the drawing speed of the elastic filament 13 is 1.1 to 400 times, particularly 4 to 100 times, more preferably 10 to 80 times the resin discharge speed in the spinning nozzle hole. It is preferable to adjust.

  The elastic filament 13 merges with the first and second extensible sheets 11 and 12 before solidification, that is, in a state capable of being fused. As a result, the elastic filament 13 is fused to these sheets 11 and 12 while being sandwiched between the extensible sheets 11 and 12. In addition, the adhesive 30 is also auxiliary bonded. That is, the elastic filament 13 is pulled and stretched while the elastic filament before solidification is fused and bonded to the conveyed sheets 11 and 12. When the elastic filament 13 is fused, heat is not applied to the extensible sheets 11 and 12 from the outside. That is, the elastic filament 13 and the sheets 11 and 12 are fused and bonded only by the heat of fusion caused by the elastic filament 13 that can be fused and the adhesive 30. As a result, of the constituent materials of both sheets 11 and 12, only the material existing around the elastic filament 13 is fused with the elastic filament, and the material existing at a position further away is not fused. As a result, since the heat applied to both the extensible sheets 11 and 12 is kept to a minimum, the good texture inherent to the sheets themselves is maintained. Thereby, the texture of the stretchable sheet 10 obtained becomes favorable.

  Until the spun elastic filament 13 joins the extensible sheets 11 and 12, the elastic filament 13 is stretched and molecules are oriented in the stretching direction. Also, the diameter is reduced. Due to the molecular orientation, an elastic filament 13 having a small strength going / return ratio (hysteresis) at 50% elongation can be obtained. From the viewpoint of sufficiently stretching the elastic filament 13 and from the viewpoint of preventing the elastic filament 13 from being broken, a wind (hot air or cold air) of a predetermined temperature is blown onto the spun elastic filament 13 to set the temperature of the elastic filament 13. You may adjust.

  The stretching of the elastic filament 13 may be not only stretching in the molten state of the raw material resin (melt stretching), but also stretching in the softened state (softening stretching) in the cooling process. The molten state is a state in which the resin flows when an external force is applied. The melting temperature of the resin is measured as a peak temperature of Tan δ by viscoelasticity measurement (for example, measured by adding vibration strain in the rotational direction to a resin sandwiched between circular parallel plates). In order to prevent thread breakage when using an elastic resin, it is preferable to secure a long stretch section. Similarly, the melting temperature of the elastic resin is preferably 130 to 300 ° C. so that the yarn breakage does not occur. Furthermore, the melting temperature is preferably 220 ° C. or less from the viewpoint of the heat resistance of the elastic resin. The molding temperature (die temperature) of the elastic filament 13 is preferably + 50 ° C. or higher of the melting temperature of the raw material resin in order to improve the flowability of the resin and improve moldability, and is preferably + 110 ° C. or lower for heat resistance. The softening temperature is measured as the Tg temperature in the viscoelastic property of the measurement sample of the elastic resin in sheet form. The range from the softening temperature to the melting temperature is called a softened state. Moreover, the state of temperature lower than softening temperature is called solidified state. The softening temperature is preferably 60 ° C. or higher, and more preferably 80 ° C. to 180 ° C., from the viewpoint of the growth of elastic resin crystals during storage of the stretchable sheet 10 and the decrease in stretchability of the stretchable sheet 10 due to body temperature.

  The temperature of the elastic filament 13 when the elastic filament 13 and the extensible sheets 11 and 12 are bonded is preferably 100 ° C. or higher in order to ensure fiber fusion. More preferably, it is 120 degreeC or more, More preferably, it is 140 degreeC or more. Further, from the viewpoint of obtaining the stretchable sheet 10 having a good stretchability by maintaining the shape of the elastic filament 13, the temperature of the elastic filament is preferably 180 ° C. or lower. More preferably, it is 160 degrees C or less. As a result, the optimum filament temperature is in the range of 120 to 160 ° C, more preferably 140 to 160 ° C. The bonding temperature is observed using a film made of a modified polyethylene or a modified polypropylene having a melting point different from the melting point of the elastic resin constituting the elastic filament as a laminate base material to be bonded to the elastic filament 13. Can be measured. At this time, if the elastic filament and the laminate base material are fused, the joining temperature is equal to or higher than the melting point of the laminate base material.

  At the time of joining the elastic filament 13 and the extensible sheets 11 and 12, the elastic filament 13 is substantially in a non-extended state (a state in which the elastic filament 13 does not shrink when an external force is removed). In some cases, the elastic filament 13 may be joined to the extensible sheets 11 and 12 under the extended state. In the joined state, at least part of the material constituting the extensible sheets 11 and 12 is fused to the elastic filament, or at least one of the materials constituting the elastic filament 13 and the extensible sheets 11 and 12. It is more preferable that both the parts are fused. This is because sufficient bonding strength can be obtained. The expansion / contraction characteristics of the resulting elastic sheet 10 are affected by the density of the joint points between the elastic filament 13 and the extensible sheets 11 and 12. In addition, the expansion / contraction characteristics can be adjusted by the joining temperature, the joining pressure, and the detachment of the joining point by the elastic expression treatment of the extensible sheets 11 and 12 described later. By bonding the constituent materials of the extensible sheets 11 and 12 to the elastic filament 13, the bonding strength of each bonding point is increased. It is preferable to reduce the density of the bonding points because the expansion / contraction inhibition by the extensible sheets 11 and 12 is reduced and the expansion / contraction sheet 10 having sufficient bonding strength can be obtained.

  When the elastic filaments 13 are merged with the extensible sheets 11 and 12, the elastic filaments 13 are arranged in one direction without crossing each other. Then, in a state where the elastic filament 13 is joined with the extensible sheets 11 and 12 and the elastic filament 13 is sandwiched between the sheets 11 and 12, these three members are clamped by a pair of nip rolls 18 and 18. The condition of the clamping pressure affects the texture of the stretchable sheet 10 obtained. If the pinching pressure is too large, the elastic filament 13 is likely to bite into both the extensible sheets 11 and 12, and the texture of the stretchable sheet 10 obtained due to this tends to be lowered. From this point of view, the clamping pressure by the nip rolls 18 and 18 is sufficient for the elastic filament 13 to contact both the extensible sheets 11 and 12, and an excessively high clamping pressure is not required.

  Another condition for the clamping pressure by the nip roll 18 is the temperature of the nip roll 18. As a result of the study by the present inventors, it is better not to heat the nip roll 18 in a heated state (that is, to leave it to the result), or to perform the pressing while cooling, a better texture. It was found that the elastic sheet 10 was obtained. When cooling the nip roll 18, it is preferable to use a coolant such as cooling water and adjust the temperature so that the surface setting temperature of the nip roll 18 is 10 to 50 ° C.

  In this way, a composite 19 in which the elastic filament 13 is sandwiched between the two extensible sheets 11 and 12 is obtained. When the stretchable sheets 11 and 12 are inherently stretchable, the composite 19 becomes the stretchable sheet 10 itself. On the other hand, when the extensible sheets 11 and 12 that do not inherently have extensibility are used, the composite 19 including the extensible sheets 11 and 12 is elastically developed along the direction in which the elastic filament 13 extends. Processing is performed to give stretchability to the composite 19. The composite 19 in this state can be expanded and contracted to some extent not only in the MD direction but also in the CD direction. When it is desired to further increase the stretchability in the CD direction, an elastic expression process may be performed in the CD direction. An example of this method is the method described in Patent Document 2. Specifically, the composite 19 may be stretched in the CD direction by a stretching device including a pair of concavo-convex rolls in which large diameter portions and small diameter portions are alternately formed in the axial length direction.

  The elastic development treatment is preferably performed after the temperature of the adhesive 30 is 40 ° C. or less, from the viewpoint that the residual strain associated with the elastic development treatment is reduced. Specific means for the elastic development treatment include, as described above, heat treatment, inter-roll stretching, biting and stretching with tooth gaps and gears, and tensile stretching with a tenter. In the following description, biting and stretching, which is a particularly preferable means among these means, will be described. In biting and stretching, an elastic expression processing device 22 having a pair of tooth gap rolls 20 and 21 in which teeth and roots are alternately formed in the circumferential direction is used, and the composite 19 is conveyed in its conveying direction, that is, in the MD direction. Along with the elastic development.

  The elastic expression processing device 22 has a known lifting mechanism (not shown) for vertically displacing the pivot portion of one or both of the tooth gap rolls 20 and 21, and the interval between the tooth gap rolls 20 and 21 can be adjusted. It has become. In this manufacturing method, each tooth gap roll 20 and 21 is inserted freely between the teeth of one tooth gap roll 21 and the tooth of the other tooth gap roll 21 is one tooth. It combines so that it may be loosely inserted between the teeth of the groove roll 20, and the composite body 19 is inserted between the both tooth groove rolls 20 and 21 of the state, and this is elastically processed.

  In the elastic expression processing device 22, both the pair of tooth groove rolls 20 and 21 may be driven by a driving source (co-rotating roll), and only one tooth groove roll 20 or 21 is driven by the driving source. In this manufacturing method, only the lower tooth gap roll 21 is driven by the drive source, and the upper tooth groove roll 20 is connected to the drive source. Instead, it is driven (rotated) as the tooth gap roll 21 rotates. The use of the accompanying roll is that the high basis weight portion 14 and the low basis weight portion 15 are likely to appear clearly and striped on the stretchable sheet 10 after the elastic expression treatment, and the design of the stretchable sheet 10 is improved. The low basis weight part 15 is preferable in that the basis weight is lower and the air permeability is improved. As the tooth profile of the tooth gap rolls 20 and 21, a general involute tooth profile and a cycloid tooth profile are used. However, these tooth widths are narrowed and backlash (gap between teeth of a pair of meshed rolls). A larger one is preferred. The backlash value is preferably 0.3 mm to 3 mm, preferably 0.5 mm to 1.5 mm.

  FIG. 5 schematically shows a state in which the composite 19 is subjected to an elastic expression process. When the composite 19 passes between the tooth gap rolls 20 and 21, the composite 19 is in a region that contacts the teeth 23 and 24 of the tooth gap rolls 20 and 21 (between P 3 and P 2 and between P 1 and P 4). Is hardly stretched. On the other hand, in the region (between P2 and P1) pressed toward the tooth surface of the tooth 23 of the tooth space roll 20 that is the driven roll by the tooth surface of the tooth 24 of the tooth space roller 21 that is the driving roll. The fibers are greatly stretched by both teeth 20 and 21 to make the fibers thinner. Further, in the region (between P4 and P3) that is separated from the tooth 23 of the tooth space roll 20 by the tip of the tooth 24 of the tooth space roll 21, it is not as large as the region (between P2 and P1), but is greatly stretched. The fiber becomes thinner.

  The composite 19 is hardly stretched as described above in the region (between P3 and P2 and between P1 and P4) in contact with the tips of the teeth 23 and 24 of the tooth gap rolls 20 and 21, but the teeth 23 and 24 are as described above. Is pushed in the radial direction, that is, in the thickness direction of the composite 19, so that it becomes thinner in the thickness direction. However, because the region (between P3 and P2) and the region (between P1 and P4) are in the opposite direction, the thinning direction is the opposite direction.

  While the elastic filament 13 and both extensible sheets 11 and 12 are prevented from being peeled by the stretching process, the both extensible sheets 11 and 12 in the composite 19 are efficiently stretched to make the composite 19 stretchable. Can be granted. And the area | region (between P2-P1 and between P4-P3) extended | stretched greatly becomes the low basic weight part 15, and the area | region (between P3-P2 and between P1-P4) hardly extended becomes the high basic weight part 14.

  In particular, when the extensible sheets 11 and 12 are made of a nonwoven fabric and the nonwoven fabric contains low-stretched fibers, the fibers are stretched between (P2-P1) and (P4-P3) described above. As a result, an indefinite fiber is formed which becomes thinner and whose thickness periodically changes. The stretching of the low-stretched fibers varies depending on the distance between (P2-P1) and (P4-P3).

  When the extensible sheets 11 and 12 are made of a nonwoven fabric containing low-stretched fibers, the stretching force by the tooth gap rolls 20 and 21 mainly acts on the stretching of the low-stretched fibers, and the extensible sheets 11 and 12 and the elastic filament 13 Excessive force is not applied to the joint area. As a result, the composite 19 can be efficiently stretched while preventing breakage of the bonded portion and peeling of the extensible sheets 11 and 12 and the elastic filament 13. Further, by this stretching, as shown in FIG. 6, the stretchable sheets 11 and 12 are sufficiently stretched without breaking the bonding between the fibers, whereby the stretchable sheets 11 and 12 are free of the elastic filaments 13. The degree of inhibiting expansion and contraction is greatly reduced. As a result, according to this production method, the stretchable sheet 10 having high strength and high stretchability and having a good appearance with little tearing and fluffing can be efficiently produced. In FIG. 6, the thickness of the inelastic fiber generated by stretching is uniformly expressed for convenience.

  As described above, when the extensible sheets 11 and 12 are made of a nonwoven fabric containing low-stretched fibers, the fibers are successfully stretched, and the joint between these fibers is not broken by stretching. The decrease in strength of the extensible sheets 11 and 12 is suppressed as much as possible. Specifically, the ratio of the tensile strength of the stretchable sheet 10 obtained after the elastic expression treatment to the tensile strength of the composite 19 before the elastic expression treatment is 0.3 to 0.99, particularly 0.5 to 0.99. Furthermore, it becomes a value close to 1 of 0.7 to 0.99. The tensile strength mentioned here is measured according to the maximum strength measuring method described below.

<Measurement of maximum strength>
A rectangular test piece was cut out in a size of 200 mm in the direction of expansion and contraction of the stretchable sheet 10 and 50 mm in a direction perpendicular thereto. The distance between chucks was 150 mm. The test piece was extended at a speed of 300 mm / min in the expansion / contraction direction of the elastic sheet 10, and the load at that time was measured. The load at the maximum point at that time was defined as the maximum strength. By the same method, the maximum strength of the composite 19 before the elastic expression treatment was also measured. The maximum strength is measured using a tensile tester AG-1kNIS manufactured by Shimadzu Corporation under the conditions of a measurement environment of 20 ± 2 ° C. and a humidity of 65 ± 5% RH.

  The composite body 19 is elastically treated by the pair of tooth space rolls 20 and 21, whereby the intended stretchable sheet 10 is obtained. After the obtained elastic sheet 10 passes through the tooth gap rolls 20 and 21, the stretched state in the MD direction is quickly released by its own contraction restoring force. As a result, the length of the stretchable sheet 10 is generally restored in the transport direction. Thereby, in the extended state, the high basis weight portions 14 and the low basis weight portions 15 are alternately arranged in the MD direction. When the stretched state is released, the stretched state may be completely released, or the stretched state may be released in a state where a certain stretched state is maintained as long as stretchability is exhibited.

  By the elastic expression processing, the thickness of the stretchable sheet 10 is preferably 1.1 to 4 times, particularly 1.3 to 3 times the thickness of the composite 19 before the elastic expression processing. . As a result, the constituent fibers of both extensible sheets 11 and 12 are plastically deformed and stretched to make the fibers thinner. At the same time, both the extensible sheets 11 and 12 become more bulky, feel better, and cushioning becomes better.

Moreover, although it also depends on a specific use, the stretch sheet 10 preferably has an overall basis weight of 10 to 150 g / m ² , particularly 25 to 60 g / m ² . Regarding the thickness of the stretchable sheet 10, it is preferably 0.05 to 5 mm, particularly preferably 0.5 to 2 mm. The thickness of the stretchable sheet 10 is measured by the same method as the measurement of the thickness of the extensible sheet 11 described above.

  The stretchable sheet 10 of the present embodiment is used for various purposes depending on the type of the extensible sheets 11 and 12. For example, when the sheets 11 and 12 are both non-woven fabrics, the stretchable sheet 10 can be used as a three-dimensional mask, a diaper exterior material, or a disposable gown. Moreover, when the sheet | seat 11 consists of a moisture-permeable film and the sheet | seat 12 consists of nonwoven fabrics, the elastic sheet 10 can be used as an elastic back sheet | seat which has the elasticity in a diaper, an absorption pad, a sanitary napkin, etc. Furthermore, when the sheet 11 is made of a moisture-impermeable film and the sheet 12 is made of a nonwoven fabric, the stretchable sheet 10 can be used as a stretchable patch.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the above-described embodiment, the adhesive 30 is applied between the two extensible sheets 11 and 12. Instead, at least one of the two extensible sheets 11 and 12 is used. On the outer surface of the sheet, the elastic adhesive 30 may be arranged in a substantially continuous linear coating pattern. Since the contact between the elastic filament 13 and the adhesive 30 is reduced, it is possible to suppress a decrease in the expansion / contraction characteristics due to storage. The adhesive 30 may be applied directly to the stretchable sheet 10, but in order to reduce thermal damage to the elastic filament by the adhesive 30, the adhesive 30 is applied to another sheet and this is attached to the stretchable sheet 10. It is preferable to match. The adhesive 30 may be applied either before or after the elastic sheet 10 is subjected to the elastic expression treatment. In the former case, it is preferable that another sheet or an absorbent body in an absorbent article is bonded to the adhesive 30. This bonding may be in the stretched state of the stretchable sheet 30 or in the relaxed state returned after stretching. In particular, the stretched state is preferable in that good stretchability can be obtained. When the elastic sheet 10 is bonded to another sheet before the elastic expression process, the three-sheet structure is formed. In this embodiment, the elastic expression process is performed on the composite 19 having the three-sheet structure.

  Further, the coating pattern of the adhesive 30 is not limited to that shown in FIG. 1, and for example, the coating pattern shown in FIG. 7 can be adopted.

  In addition, regarding the elastic expression processing using the elastic expression processing device 22 in the method for manufacturing the stretchable sheet, the elastic expression processing direction is not limited to the flow direction of the extensible sheets 11 and 12, but may be, for example, oblique. Furthermore, it is possible to combine two or more kinds of elastic expression treatment methods, increase the draw ratio stepwise, or partially perform the elastic expression treatment. The elastic development processing direction may be not only one direction but also two orthogonal directions.

  Moreover, in the manufacturing method of the said embodiment, although the elastic expression processing apparatus provided with a pair of tooth space roll 20 and 21 was used for the elastic expression processing, it replaced with using the elastic expression processing apparatus provided with the tenter. Elasticity treatment processing may be performed.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
The stretchable sheet 10 shown in FIGS. 1 and 2 was manufactured using the apparatus shown in FIG. As the extensible sheet 11, a stretched moisture permeable film (basis weight 20 g / m ² ) having a moisture permeability of 2.2 g / (100 cm ² · hr) containing calcium carbonate and polyethylene was used. As the extensible sheet 12, a water-repellent air-through nonwoven fabric having a basis weight of 20 g / m ^{2 made} of a core-sheath type composite fiber (core: PET, sheath: PE) having a fiber diameter of 19 μm and a fiber length of 44 mm was used. The maximum elongation of this nonwoven fabric was 170%. As an elastic filament material resin, an elastomer made of SEPS resin (weight average molecular weight 50,000, MFR 60 g / 10 min (230 ° C., 2.16 kg) (JIS K7210: 1999) was used. The spinning condition of the elastic filament 13 was spinning. The temperature of the head 17 was 310 ° C., the diameter of the spinning nozzle 16 was 450 μm, and the pitch of the spinning nozzle 16 was 1.5 mm, and the filament diameter was an average of 145 μm. Was applied by curtain coating at 190 ° C. so that the basis weight was 8 g / m ² , and the apparent basis weight of the filament (filament weight in the stretch sheet 10 / area of the stretch sheet 10) was 10 g / m ² , stretching ratio was 9.6 times. draw ratio is defined by (a nozzle hole diameter / stretch expression pretreated fiber diameter) ² The nip roll 18, using a metal roll and a rubber roll. The elastic filaments 13 fusion and adhered during the extension sheet 11 by the rolls. Was thereby obtain a composite 19.

The elastic expression processing of the composite 19 was performed using an elastic expression processing device 22 provided with a pair of tooth space rolls 20 and 21 in which teeth and roots were alternately formed in the axial length direction. The pitch between teeth and the bottom of each tooth was 2.0 mm (the pitch P between teeth in the meshed state was 1.0 mm). The indentation amount of the upper and lower tooth gap rolls was adjusted, and the composite 19 was elastically treated in the MD direction at a draw ratio of 2.0 times. Next, in the CD direction, stretching was performed using the stretching apparatus described in Patent Document 2, and an elastic expression treatment was performed. This stretching apparatus includes a pair of concave and convex rolls in which large diameter portions and small diameter portions are alternately formed in the axial length direction. The pitch between the large diameter part and the large diameter part of the one-sided roll was 2.0 mm. The draw ratio was 1.5 times. As a result, the stretchable sheet 10 having a basis weight of 53 g / m ² that stretches well in both the MD direction and the CD direction was obtained.

[Example 2]
In Example 1, as the extensible sheet 11, the same one as the extensible sheet 12 was used. Except for this, the stretchable sheet 10 was obtained in the same manner as in Example 1. The obtained stretchable sheet stretched well in both the MD direction and the CD direction.

Example 3
In Example 1, as the extensible sheet 11, the same one as the extensible sheet 12 was used. Further, the adhesive 30 was not applied. The composite 19 before the elastic expression treatment obtained in this way was wound up. Next, while this composite 19 was fed out, a stretchable hot melt was applied to the outer surface of the extensible sheet 11 with a basis weight of 8 g / m ² . On top of that, the same stretched breathable film used in Example 1 was bonded. Thereafter, the same elastic development treatment as in Example 1 was performed to obtain an elastic sheet 10. The obtained stretchable sheet stretched well in both the MD direction and the CD direction.

FIG. 1 is a partially broken perspective view showing a first embodiment of the stretchable sheet of the present invention. 2A and 2B are longitudinal sectional views in a natural state and an extended state, respectively, along the extending direction of the elastic filament in the stretchable sheet shown in FIG. FIG. 3 is an SEM image showing an example of an inelastic fiber in which the diameter (cross-sectional area) of the fiber is changed in a substantially step shape. FIG. 4 is a schematic view showing an apparatus suitably used for manufacturing the stretchable sheet shown in FIG. FIG. 5 is a schematic view showing a state in which the composite is subjected to an elastic expression treatment by the apparatus shown in FIG. FIG. 6 is a schematic diagram showing a state where the non-elastic fiber is subjected to an elastic expression process. FIG. 7 is a schematic view showing another application pattern of the adhesive.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stretch sheet 11 Stretchable non-stretchable sheet 12 Stretchable non-stretchable nonwoven fabric 13 Elastic filament 14 High basis weight area 14 'Top part 14 "Valley part 15 Low basis weight area 15' Ridge part 30 Adhesive

Claims (2)

A composite in which a large number of elastic filaments arranged so as to extend in one direction are sandwiched between two stretchable non-stretchable sheets is subjected to an elastic expression treatment at least along the extending direction of the elastic filaments. A method for producing a stretchable sheet that imparts stretchability to a composite and stretches along a direction in which the elastic filament extends,
An adhesive having elasticity, is applied to another sheet from said non-stretchable sheet,
Wherein after the elastic expression treatment was performed to the composite body, said further sheet the adhesive has been applied having stretchability, hand among the two in the said complex extended state non-stretchable sheet A part of the linear portion extending in a direction perpendicular to the direction in which the elastic filament extends is partially bonded to the outer surface of one of the non-stretchable sheets. Formed in a substantially continuous linear pattern to have
The elastic development process is a biting and stretching process in which the complex is bitten between the tooth gap rolls in an elastic expression processing apparatus including a pair of tooth gap rolls in which teeth and roots are alternately formed in the circumferential direction. The manufacturing method of the elastic sheet which is. In the said elasticity expression process, the manufacturing method of the expansion-contraction sheet | seat of Claim 1 which sets ratio of the diameter of the said elastic filament, and the tooth | gear clearance between said tooth gap rolls to 0.2-1.