JPH0647808A - Manufacture of elastic composite body - Google Patents

Abstract

PURPOSE:To prevent the generation of loss in manufacture and the like by stretching an elastomer film in the biaxial direction, bonding the stretched film with a base of low stretching properties in the linear shape and the like in the vertical and horizontal directions and then heat a composite body thus prepared and heat shrinking the elastomer film only. CONSTITUTION:In the preparation of an elastic composite body 26, first a belt 2 is driven by a motor 1 and an elastomer film 20 delivered from a delivery section 3 is stretched in the biaxial direction, for instance, in the vertical direction and the horizontal direction respectively by a stretching tank 4. Then a base 22 of stretching properties lower than that of the elastomer film 20 is delivered from a delivery section 5 and polymerized with the biaxially stretched film 21, and the composite body 23 is bonded, for instance, into the linear shape and the like in the horizontal direction by a heat sealing section 6, and further a composite body 24 thus prepared is bonded into the linear shape and the like in the vertical direction by another at sealing section 9. Then, a composite body 25 thus prepared is passed through an oven 12, and the stretched film 21 only is heat shrinked. An elastic composite body 6, in which the base 22 represents the dome shape, is prepared by the arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an elastic composite body, which has various functions such as elasticity, and therefore can be used for various purposes such as gathers for helmet inner hats, arm bands, bandages, diapers and the like. It relates to a method for producing a composite.

[0002]

Unstretched elastic members are discontinuously bonded to a substrate that is less stretchable than the elastic members to form a composite, the composite is stretched, and then the composite is stretched. A method for producing an elastic composite by relaxing it has been proposed (Japanese Patent Laid-Open No. 59-59901).

[0003]

However, this method is
After the film and the substrate are bonded discontinuously, the film is stretched. Especially when the stretching is in the lateral direction, it is a method of gripping both ends of the composite with clips,
There is a drawback that loss is likely to occur at both ends and that the device cost is high. Further, in this method, there is a limitation that the base material can also be stretched for the purpose of stretching after bonding. The present invention aims to provide a technique capable of solving the drawbacks of the conventional technique.

[0004]

According to the present invention, after stretching an elastomer film in a biaxial direction, at least one surface of the biaxially stretched film and a substrate having a lower extensibility than the elastomer film are longitudinally and / or Alternatively, in a method for producing a stretchable elastic composite, which is formed by adhering linearly or dots in a lateral direction at appropriate intervals and then heating the composite to heat-shrink the biaxial elastomer film. It is related.

[0005]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an overall explanatory view showing an example of an embodiment process of the present invention, in which 1 is a drive motor, 2 is an axial drive belt, 3 is an elastomer film feeding portion, 4
Is a drawing tank, 5 is a base material feeding part, 6 is a heat seal part, 7 is a heat seal roll, 8 is a slide device, 9 is a heat seal part, 10 is a heat seal roll, 11 is a silicone rubber roll, and 12 is hot air. The circulation oven 13 is an elastic composite winder.

As shown in FIGS. 1 and 2A, first, the elastomer film 20 is biaxially stretched. The elastomer film 20 may be an elastomer film made of natural rubber or synthetic rubber, but is a composition of ethylene-propylene-propylene copolymer rubber (EPDM) and ethylene-vinyl acetate copolymer (EVA). Is preferably from the viewpoint of stretchability, thinning, low temperature shrinkability, printability, and the like. The E
An elastomer film composed of PDM and EVA can be prepared by combining 30 to 70% by weight of EPDM and 70 to 30% by weight of EVA having a vinyl acetate content of 5 to 30% by weight, and further adding polyethylene to this composition up to 30% by weight. Is kneaded at a temperature of 160 ° C. or lower, and a film is formed by an air-cooled inflation method with a blow-up ratio of 2.0 to 5.0. As a method for producing such a film, the method disclosed in JP-A-3-128945 can be applied. Stretching is carried out, for example, in a stretching tank 4 at a suitable stretching temperature, preferably from room temperature to 50 ° C., as shown in FIG. 2 (B), in the biaxial direction of the film, preferably in the longitudinal direction. (Machine Direction,
MD to 1.2 times to 4.0 times in the lateral direction (Transve
rse Direction, MD) 1.2 times to 4.
Draw 0 times. In addition, in the film formation by the air-cooled inflation method, if stretching corresponding to the above-mentioned magnification is performed in the MD direction and the TD direction, the stretching in the MD direction and the TD direction is not necessary before the composite with the substrate.

As shown in FIG. 1, a substrate 22 having a lower extensibility than the elastomer film 20 such as paper, plastic film, woven fabric, non-woven fabric, metal foil, etc. The base material 22 and the biaxially stretched film 21 that has been biaxially stretched as described above are overlapped, and the composite body 23 is adhered in a linear or dotted shape such as a line or a dotted line in the longitudinal and lateral directions. As shown in FIGS. 1 and 3 (A), the bonding is performed by using the heat-sealing portion 6 as shown in FIG.
The heat seal roll 7 having irregularities as shown in FIG.
The slide film 8 is appropriately slid and pressed, and the stretched film 21 and the substrate 22 are linearly adhered to each other in the transverse direction (TD) at appropriate intervals as shown in FIG. 3 (D). . The heat seal roll 7 used has, for example, a width (W ₁ ) of its convex portion of 1.0 to 5.0 mm and a width (W ₂ ) of its concave portion of 3.0 to 12.0 mm, and The height (H) is set to 2.0 mm (FIG. 3 (C)). Next, as illustrated in FIG. 1 and FIG. 4 (A), at the heat seal portion 9, an appropriate space is provided in the transverse direction (TD) between the heat seal roll 10 and the silicone rubber roll 11 as described above. Place and thread the linearly bonded composite 24 through FIG.
As shown in (B), it is further adhered linearly at appropriate intervals in the longitudinal direction (MD). A heat-sealing roll 10 as shown in FIG. 4B is used for the adhesion. The heat seal roll 10 has, for example, a width (W ₁ ) of its convex portion of 1.0 to 5.0 mm and a width (W ₂ ) of its concave portion of 3.0.
~ 12.0 mm, and its height (H) is 2.0 ~
It is configured to be 5.0 mm (FIG. 4 (C)). Thus, as shown in FIG. 4 (D), the composite 25 is linearly bonded at appropriate intervals in the horizontal direction (TD) and the vertical direction (MD). In addition to the heat sealing method, a hot melt method in which a hot melt adhesive is applied linearly or in dots, a dry laminating method, or a wet laminating method depending on the substrate may be used.

Examples of the plastic film for the substrate 22 include polyolefin films such as polypropylene and polyethylene. The base material 22 can be appropriately selected according to the application of the elastic composite of the present invention.
Are not required to have stretchability. As will be described later, the base material 22 can be freely expanded and contracted, and
It is possible to give the elastic composite the function of
When the base material 22 is paper, it imparts air permeability and water absorption, and when the base material 22 is a nonwoven fabric, it imparts air permeability and moisture permeability,
Further, when the substrate 22 is a plastic film,
Improve strength.

Then, as shown in FIG. 1, the composite body 25 adhered in a line at a proper interval in the transverse direction (TD) and the longitudinal direction (MD) is then slit into a predetermined size, It is passed through the hot air circulation type oven 12 at an appropriate temperature, for example, at 70 to 90 ° C. to heat-shrink only the elastomer stretched film 21 constituting the composite 25. The heat shrinkage is performed in the range of 10% to 100%, for example. The film is heat-shrinked in the longitudinal direction and the direction perpendicular thereto, while the base material 22 such as paper, plastic film, woven cloth, non-woven cloth, and metal foil is hardly shrunk, so that as shown in FIG. An elastic composite body 26 in which the base material 22 has a dome shape is obtained. In the above, the method of continuously producing the elastic composite body 26 has been described, but the composite film 25 may be once wound as it is after heat sealing and may be passed through the hot air circulation type oven 12 in another step. The method is effective in terms of preventing blocking and preventing bulkiness.

Next, examples of the present invention will be described. Example 1. 54% by weight of ethylene-propylene-diene copolymer (manufactured by Exxon Chemical Co., trade name V3708), 36% by weight of ethylene-vinyl acetate copolymer (manufactured by Nippon Unicar Co., trade name DQDJ-3269), and low-density polyethylene ( Made by Nippon Unicar, product name DFD-0148) 1
A film having a thickness of 20 μm (an air-cooled inflation film having a blow-up ratio of 5.0) made of a thermoplastic elastomer composition containing 0% by weight was added at 50 ° C. to 2.0 times in the longitudinal direction (MD direction) of the film. Lateral direction (T
A biaxially stretched film (hereinafter referred to as biaxially stretched film A) formed by stretching 2.0 times in the D direction) and a commercially available inorganic-filled linear low-density polyethylene film having a thickness of 35 μm (hereinafter referred to as film B). After saying that,
Using a device as shown in FIG. 1, a line speed of 10 m / min and a line speed of 30 m / min were set at regular intervals in the longitudinal direction of the film and the direction perpendicular to the longitudinal direction.
Heat sealing was performed for min to obtain a composite film. The heat sealing temperature at this time was 140 ° C. in the heat sealing portion 6 and 110 to 150 ° C. in the heat sealing portion 9. When the obtained composite film was passed through a hot air circulation type oven at a temperature of 80 ° C., the biaxially stretched film A contracted about 1/2 in the longitudinal direction and about 1/3 in the direction perpendicular to the longitudinal direction, Since the film B did not shrink, an elastic composite as shown in FIG. 5 was obtained.

Embodiment 2. The biaxially stretched film A used in Example 1 and an ethylene vinyl acetate copolymer resin (manufactured by Nippon Unicar Co., Ltd., trade name DQDJ186) containing 15% by weight of an inorganic substance (manufactured by Shiraishi Calcium Co., Ltd., trade name Ryton-A).
A film having a thickness of 35 μm (hereinafter, referred to as a film C) formed by inflation using 8) was used, and the film C and the biaxially stretched film A were used to obtain a composite film in the same manner as in Example 1 above. Then, the composite film was similarly passed through an oven of a hot air circulation type at a temperature of 70 ° C. to obtain an elastic composite.

Embodiment 3. Tissue paper (made by Tojo Kimberley, product name JK wiper tissue 1)
No. 00) was used to obtain a composite with the substrate (D) and the biaxially stretched film A used in Example 1 in the same manner as in Example 1 above, and then the composite was similarly heated with hot air. The mixture was passed through a circulating oven at a temperature of 80 ° C. to obtain an elastic composite.

Embodiment 4. As a base material, a polypropylene spunlace nonwoven fabric having a basis weight of 35 g / m ² which is slightly stretchable in length and width is used. This base material (E) and the biaxially stretched film A used in Example 1 are used in the above Example 1 After obtaining a composite in the same manner as in 1., the composite was passed through a hot air circulation type oven at a temperature of 85 ° C. to obtain an elastic composite.

For comparison, a composite film was obtained in the same manner as in Example 1 except that an elastomer film that was not stretched in the machine direction or the transverse direction was used. The composite film was stretched in the machine direction and the transverse direction at 50 ° C. However, it could not be stretched sufficiently, and the elasticity of the obtained composite was relatively small, and it was insufficient as an elastic composite.
(Comparative Examples 1 and 2) Also, for comparison, a composite film was obtained in the same manner as in Example 3 except that an elastomer film that was not stretched in the machine direction and the transverse direction was used. 50 of this composite film
When stretched in the machine direction and the transverse direction at 0 ° C., the tissue paper was cut and the desired elastic composite was not obtained. (Comparative Examples 3 and 4)

The features of the product of the present invention will be described from the results of the above-mentioned examples as follows. (1) The elastic composite of Example 1 has both a stretch function and a bulky feel. (2) The tensile strength at the initial elongation is the same as that of the elastomer film (A), and the elastic film is stretched with a weak force up to a certain point. When stretched by 30 to 50% or more (100%), the stretch strength shows the characteristics of the substrates to be laminated, and in this case, the strength of the film (B) appears. When the film (B) is stretched to 30% or more, the strain increases in proportion to the elongation and cannot be restored. However, in the elastic composite of Example 1, the film (A) is stuck at a constant interval. Therefore, when the stress is removed, the original shape is restored and no strain remains. That is, the composite has improved strength in proportion to the degree of elongation, has resilience, and has small strain. (3) Since the film (A) is stretched biaxially in the longitudinal and transverse directions, if it is wound up as it is, the winding tightness is large and a problem occurs in blocking at the time of unwinding. On the other hand, such a problem does not occur in the first embodiment. (4) Films (A) and (B) have almost no air permeability and moisture permeability as the substrate itself, but as shown in Example 1, according to the present invention, air permeability and moisture permeability are It imparts wettability and allows water vapor and gas to pass through the gaps. (5) The elastic composite body of Example 2 also has the same features and functions as those described in the above items. (6) Further, the features seen from the third and fourth embodiments will be described. The elastic composites of Examples 3 and 4 are made of spunlaced nonwoven fabric made of PP having a base material of tissue paper and slightly stretchable property, respectively. In the general function as an elastic composite, it has advantages similar to the above. In addition, there are the following advantages based on the function of the base material. It should be noted that each feature can be brought out according to the different functions of the base material. For example, since the base material of Example 3 is pulp, it has water absorbency, and based on this, it can be used as an edge band of a paper hat that is worn inside a helmet or the like to prevent dirt, and has various advantages. Can be a body. The base material of Example 4 was
Since it is a soft non-woven fabric, it matches human skin,
It can be used for various gathers such as arm bands (bandage stoppers) and diapers, and can also be made into an elastic composite body having various advantages as well.

[0016]

As described above, the present invention has the following advantages. (1) A conventional non-stretched elastic member is discontinuously bonded to a substrate having lower stretchability than the elastic member to form a composite, the composite is stretched, and then the composite is relaxed. In the method of obtaining an elastic composite by doing so, the clip is used to hold both ends to perform expansion, which results in a loss that is large and the device cost is high. Therefore, there is a limitation that the substrate can be stretched. In contrast,
According to the present invention, since the heat shrinkability of the stretched film is used, no loss occurs, and the present invention does not need to limit the substrate. (2) According to the present invention, it is possible to obtain an elastic composite body having both a stretch function and a bulky feel. This elastic composite has elasticity and volume feeling in common regardless of the substrate to be laminated. (3) When the conventional single base material is stretched to 30% or more, the strain increases in proportion to the elongation and cannot be restored. However, when the elastic composite of the present invention removes the stress, It returns to the shape of, and there is no distortion, and the strength is large and the distortion is small even at 100% elongation. (4) In the olefin film alone film, the substrate itself has almost no air permeability and moisture permeability, but according to the present invention, air permeability and moisture permeability are imparted, and water vapor or gas passes through the gap. become able to. The elastic composite of the present invention can be freely stretched and can also be used as a packaging member. Not only can it be applied to the packaging of lightweight or small products, but it can also be applied to the packaging of heavy or large products, allowing for flexible control. Therefore, when the stretchable film is used alone, it is possible to prevent a decrease in yield strength with respect to a heavy object or a bulky object, and it is also possible to solve the problem of a decrease in tensile strength at high temperature. In the above-described embodiments, the example is shown in which the lines or dots are adhered at appropriate intervals in the vertical direction and / or the horizontal direction, but the lines are formed at appropriate intervals in either the vertical direction or the horizontal direction. Alternatively, they may be adhered in spots. In addition, although an example of adhering linearly in the longitudinal direction and / or the lateral direction at appropriate intervals has been shown, for example, a base material having a lower extensibility than the elastomer film 20, such as paper, plastic film, woven fabric,
It is also possible to use a net-like material of the base material 22 such as a non-woven fabric or a metal foil and attach them in a dot shape at appropriate intervals in the longitudinal and / or lateral directions. Further, in the present invention, both surfaces of the biaxially stretched film and a base material having lower extensibility than the elastomeric film are adhered in a longitudinal or / and a transverse direction at appropriate intervals in a linear or dot shape. Alternatively, a plurality of these films or substrates may be used.

[Brief description of drawings]

FIG. 1 is an overall explanatory view illustrating a process of an embodiment of the present invention,

2A is an explanatory diagram of a stretching step in an example of the present invention, FIG. 2B is an explanatory diagram of the stretching,

3A is an explanatory view of a heat sealing process in an embodiment of the present invention, FIG. 3B is an external view of a heat sealing roll used for the heat sealing, and FIG. 3C is a configuration diagram of the heat sealing roll.
(D) is an explanatory view of the heat seal,

4A is an explanatory view of another heat sealing step in the embodiment of the present invention, FIG. 4B is an external view of a heat sealing roll used for the heat sealing, and FIG. 4C is a configuration of the heat sealing roll. Figure, (D) is an explanatory view of the heat seal,

FIG. 5 is a structural diagram of an elastic composite body showing an embodiment of the present invention.

[Explanation of symbols]

 20 ... Elastomer film, 21 ... Biaxially stretched elastomer film, 22 ... Substrate 23 ... Composite 24 ... Composite 25 ... Composite 26 ... Elastic composite

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B32B 7/14 9267-4F 25/04 // B29L 9:00 4F 31:48 4F

Claims (1)

[Claims] 1. An elastomer film is stretched biaxially, and at least one surface of the biaxially stretched film and a substrate having a lower extensibility than the elastomer film are longitudinally and / or laterally spaced at appropriate intervals. A method for producing an elastic composite, which comprises placing the composite on a line or in a spot and then heating the composite to thermally shrink the biaxially stretched elastomer film.