JPS6036382B2 - Laminated materials and their manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a laminate and a method for manufacturing the same.

More specifically, the present invention relates to a laminate material that can be effectively used as a film for covered cultivation, and a method for producing the same. Conventionally, various plastic films used for covering cultivation in vinyl houses, vinyl tunnels, greenhouses, etc. have heat retention properties at night, but they tend to become damp during the week, and also cause phenomena such as water droplets to fall. This will lead to the occurrence of diseases and deterioration of quality of the plants.

If a relatively thick non-woven fabric is used, the overgreen condition can be avoided due to its breathability, but this time the heat retention is unsatisfactory. Therefore, a laminated material of a plastic film and a fibrous sheet such as a nonwoven fabric may be considered, but if the conventionally used plastic film is used, the formation of an overhumidity state cannot be avoided. SUMMARY OF THE INVENTION An object of the present invention is to provide a laminated material that has heat retaining properties while avoiding the formation of an overhumidified state and preventing water droplets from falling.

The present invention also provides a laminate material that is permeable to moisture but impermeable to gases other than water vapor, and this property further enhances heat retention and further prevents the formation of an excessively muddy state. The purpose is to Another object of the present invention is to provide a method for manufacturing such a laminate. The object of the present invention is to heat-treat a nonwoven fabric sheet on one side, preferably a spunbond nonwoven fabric made of continuous fibers of polyolefin such as polypropylene, polyethylene, polyamide, or polyester, and to apply polyvinyl on the other side of the nonwoven fabric sheet. This is achieved using a laminated material in which alcohol films are laminated and integrated. The structure of such a laminate is made by applying heat treatment to one side of a spunbond nonwoven fabric, and applying a polyvinyl alcohol film or film-like material to the other side in a hydrated and heat-softened state, or by using an adhesive. This is done by crimping and joining. In this case, the other surface may also be heat treated,
Such embodiments are also included in the present invention. The nonwoven fabric sheet used is a bulky sheet in which many layers of continuous fibers are stacked or intertwined three-dimensionally, and because it contains a large amount of air, it has excellent heat retention properties.

Therefore, bulkier materials are preferable, and from this point of view, structures in which continuous fibers including long fibers are assembled, such as continuous fiber sheet-like deposits produced by spunbond method, are preferable than short fibers. At least one side of this sheet-like deposit is
It is preferable to perform heat treatment, for example, heat embossing using a heated metal roll, particularly spot bonding. When moisture accumulates in such a nonwoven fabric sheet layer, it is drained in the plane direction, but polyolefin fibers such as polypropylene fibers and polyethylene fibers are preferable from the viewpoint of water resistance against such moisture, and membrane resistance is preferable. Polyester fibers are preferably used when the fibers are used in required applications, and polyamide fibers are also used. The film or film-like polyvinyl alcohol to be laminated and integrated with the nonwoven fabric sheet preferably has a degree of polymerization of about 1000 or more, a degree of saponification of about 95% or more, and a hot water dissolution temperature of about 50° C. or more. Additionally, the addition of glycol, which is generally used as a softening agent, increases the ease of handling as a polyvinyl alcohol film;
Since there is a risk that a water-curing softener will dissolve in water and fall onto the tower plants, damaging the plants, it is desirable to keep the amount added to a minimum and to select the type. The nonwoven fabric sheet and the film or film-like polyvinyl alcohol are laminated and integrated by a casting method or a laminating method.

In the casting method, a film-forming stock solution generally having a polyvinyl alcohol concentration of about 5 to 60%, preferably about 10 to 40%, is cast onto a rotary drying drum (roll) or belt through a slit or coated with a roll coater.
Since the polyvinyl alcohol film material cast in this manner immediately after film formation contains a large amount of water and is in a softened state by heating, the preferably fiber textured surface of the nonwoven fabric sheet is pressed onto this film material. Depending on the degree of this crimping, the polyvinyl alcohol layer is inserted into the nonwoven fabric sheet, preferably with one side of each of the nonwoven fabric sheet and the polyvinyl alcohol film layer forming both sides of the laminate, and then the drum ( By drying moisture on a roll or belt, the nonwoven fabric sheet and the polyvinyl alcohol film are laminated and integrated. Alternatively, a polyvinyl alcohol film-forming stock solution may be cast onto a nonwoven fabric sheet in the form of a film and pressed to form a laminate. Furthermore, the nonwoven fabric sheet and the polyvinyl alcohol film produced in advance or immediately after extrusion are bonded, and at the time of bonding, water is applied to the surface of the polyvinyl alcohol film and heated, or heated steam is sprayed to make the polyvinyl alcohol hydrated and It is also possible to employ a method in which they are heated to a soft, Q-lowered state and then laminated and integrated by pressure bonding. In the lamination method, a nonwoven fabric sheet and a preformed polyvinyl alcohol film are pressure-bonded via an adhesive, for example, an isocyanate adhesive solution, and the two are laminated and integrated.

In this case, although it is difficult to obtain a sufficiently high adhesive strength, heat retention and moisture permeability can be controlled by the adhesive layer. As shown in the drawing, which is a cross-sectional view of one embodiment of the laminate according to the present invention, the layer of polyvinyl alcohol film 4 that is laminated and integrated on the rough fiber surface 3 side opposite to the heat-treated surface 2 of the nonwoven fabric sheet 1 is The nonwoven fabric sheet and the polyvinyl alcohol film are bonded together under a little pressure compared to natural contact, and penetrates into the fiber layer to about half the thickness of the nonwoven fabric sheet. The fiber layer, which does not participate in bonding, functions as an air enclosing layer to increase heat retention.

If the pressure applied during crimping is further increased, the penetration depth of the polyvinyl alcohol can be increased to the entire thickness of the nonwoven fabric sheet. Approximately 100 to 1
Heat treatment at 8,000 ℃, preferably about 110 to 130 ℃, increases the crystallinity of the polyvinyl alcohol surface,
As a result, the hot water melting temperature and mechanical strength are improved. Furthermore, mechanical strength can also be improved by adding a humidity conditioning process. Furthermore, if the polyvinyl alcohol surface is embossed, or if a film is used that has been embossed on one side in advance, mutual adhesion will be improved and opening/closing work in the greenhouse will be facilitated. The polyvinyl alcohol film layer that constitutes a part of the laminate has extremely low permeability to gases other than water vapor, so together with the presence of the fibrous layer of the nonwoven fabric sheet, it further increases heat retention, while moisture is transferred to the outside by internal diffusion. Since the water evaporates into the air, it maintains an appropriate internal temperature and prevents water droplets from falling.

Therefore, the laminated material according to the present invention has a remarkable effect of preventing moisture while having heat retention properties. Moreover, since polyvinyl alcohol has good weather resistance, the laminate can withstand long-term outdoor use. By effectively utilizing these properties, the laminate material of the present invention can be used as a film for covering towers such as vinyl houses, vinyl tunnels, and greenhouses. For example, when used as a film for a vinyl house, this laminated material can of course be used alone, but it is effective to cover the outside with a normal plastic film, and then cover the inside with this coating at a slight interval. When used as a double house covered with wood, it is extremely effective in retaining heat, preventing moisture, and preventing water droplets from falling. The coating material of the present invention can also be effectively used as a base material for warm or lined compresses, separation membranes in the chemical field such as dialysis membranes, or wallpaper. When laminates are used for these purposes, the nonwoven sheet has a basis weight of about 20 to 6 g/m, preferably 30 to 50 g/m, and the thickness of the polyvinyl alcohol film layer is about 10 to 75 g/m, preferably about 30-50
The best effect can be obtained when the Buddha is combined. Next, the present invention will be explained with reference to examples.

Example Polypropylene was blended with an ultraviolet absorber, and continuous fibers with a weave of 8 denier were spun into fused paper yarn using a spunbond method to obtain a nonwoven fabric with a basis weight of 40 g.

This nonwoven fabric was passed between an embossed roll and a nylon roll heated to 16,000 ℃, and spot bonding was applied from one side to suppress the occurrence of fuzz. On the other hand, a 20% aqueous solution of polyvinyl alcohol was cast into a film through the slit onto a heated roll, and the nonwoven fabric sheet was placed on top of the heated roll.
The fiber assembly side opposite to the heat-treated side of the sheets was placed one on top of the other, and the sheets were dried with hot air while lightly pressurizing the rolls. After that, 110
Heat treatment was performed by contacting with a heated roll at ℃. In the obtained laminate, one side of the nonwoven fabric was heat-embossed, and the other side was formed with a film layer of polyvinyl alcohol at a rate of 45 g/a in a state that penetrated into the fiber gaps.

The tensile strength of this laminated material was adjusted to 20 qo and relative humidity of 65%.
When measured after the German time scale overflowed, the vertical direction was 12k9/
Values of 10 rib width and 4k9/IQ rib width in the lateral direction were obtained. Furthermore, when the moisture permeability of various materials including the laminate of the present invention was measured at a humidity of 40 qo and a relative humidity of 90%, the following values were obtained. Measurement material Moisture permeability (ground/de/2 hours) Laminated material of the present invention
1000 polypinyl alcohol film 1000 vinyl chloride-vinyl acetate copolymer film
100 Furthermore, in a vinyl house in which two types of films for covering cathedrals are double-strung at an interval of about 20 arcs, a polyvinyl chloride film is used as the outer film, and a polyvinyl chloride film of the present invention is used as the inner film. When the laminated material was stretched with the non-woven sheet layer on the inside, there was no temperature difference inside the vinyl house compared to when a single layer of polyvinyl chloride film was stretched, and the relative humidity was 88%, so no saturated state was formed. Ta.

In addition, even if moisture accumulates in the nonwoven fabric sheet layer, it does not fall onto the cultivated plants as water droplets, and on the contrary, it increases the tear resistance of the laminated material, which tends to tear easily when dried. bring about.

[Brief explanation of the drawing]

The drawing is a cross-sectional view of one embodiment of the laminate according to the present invention.

Claims (1)

[Scope of Claims] 1. A laminate comprising a nonwoven fabric sheet whose one surface is heat-treated and a polyvinyl alcohol film laminated on the other surface of the nonwoven fabric sheet. 2. The laminate according to claim 1, wherein the nonwoven fabric sheet is a spunbond nonwoven fabric made of continuous fibers of polyolefin, polyamide, or polyester. 3. The laminate material according to claim 1, which is used as a film for covered cultivation. 4 Heat treatment is applied to one side of a nonwoven fabric sheet made of continuous fibers produced by the spunbond method, and a cast polyvinyl alcohol film-like material containing water and softened by heat is bonded to the other side, A method for producing a laminated material characterized by laminating and integrating both. 5. The method for producing a laminate material according to claim 4, wherein the cast polyvinyl alcohol film-like material that is water-containing and heat-softened is a water-containing film immediately after being cast. 6. The laminate according to claim 4, wherein the casted polyvinyl alcohol film-like material containing water and being softened by heating is obtained by adding water to a dry casting film and heating it, or by spraying heated steam. Manufacturing method of wood. 7 Heat treatment is applied to one side of a nonwoven fabric sheet made of continuous fibers produced by the spunbond method, and a polyvinyl alcohol film is crimped to the other side via an adhesive, thereby laminating and integrating the two. Characteristic manufacturing method for laminated materials.