JPS58193139A - Damping sheet and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

Conventional manufacturing methods for cushioning materials using general cell spaces are broadly divided into thermoplastic resin foam and thermosetting resin foam.For the former, a chemical foaming agent is mixed and one bead is heated. A bead method in which the resin is foamed using a bath melt extrusion method, a bath melt extrusion method in which gas is blown into the resin in the equipment during bath melt extrusion, or a chemical foaming agent is added to foam the resin, and a method in which raw materials containing gas are foamed under normal pressure or pressurization. etc., and the latter is,
Methods such as the use of reaction gas produced by urethane foam and phenol foam, and methods of stirring and foaming a mixture of an uncured resin solution and a surfactant are known, and are used in the production of cushioning materials used as packaging materials. The former thermoplastic resin foam is used because of its flexibility.

In addition to this, a method has also been implemented in which air vacuoles are provided by laminating a base material with a vacuum-formed vacuole space and an unmolded base material. Among the cushioning materials using thermoplastic plastics described above, most cushioning sheets used in sheet form are manufactured using bath melt extrusion and vacuum forming, which are relatively easy to manufacture continuously.

By the way, the characteristics of a cushioning material that generally has excellent cushioning properties include that the material itself is flexible, and that the structure has a structure that provides cushioning properties, such as bubbles or spaces. However, in the physical foaming method used for many thermoplastic resin foams or the chemical foaming method using a chemical foaming agent, the size of the resulting bubbles is usually
The limit is several tens of microns, and in order to obtain larger bubbles, it is necessary to destroy the wall of the bath-melted thermoplastic resin as the bubbles grow, or to break the membrane during film formation in the extrusion method into a sheet. Many problems need to be taken into consideration, such as reduced bubble growth due to gases diffusing into the molten resin and escaping out of the resin.Furthermore, a common drawback of conventional foaming methods is that the foamed and unfoamed parts are There are problems such as the technical difficulty of creating cushioning materials by forming them on the same plane, so a method of laminating a vacuum-formed base material with bubble-like spaces and a flat base material has been implemented. It's just that.

The object of the present invention is to improve the above-mentioned drawbacks of the conventional method and to easily provide a cushioning sheet made of thermoplastic resin foam.

In the present invention, a pyrolysis gas generating material layer (3) in a regular halftone pattern is formed on the surface or both front and back surfaces of the plastic film base material (A) in FIG. 1, and the material layer (3) of the base material fAJ is ) A cross-linking reaction-curing adhesive layer (4) with a reverse halftone pattern is formed on the non-coated portion, and the adhesive layer (4) is formed on the base material (N) and another plastic film base material (Bl').
), and between the base material (AJ and (Bl), the above material η layer +
3) The cell space (
5) is a cushioning sheet characterized by forming the above.

The cushioning sheet of the present invention has a pyrolysis gas generating material layer (3) formed in a regular pattern of halftone dots on the surface or both sides of the base material (N) as shown in FIG. As shown in FIG. ) Another plastic film base material (B) is laminated to the adhesive layer (4) while being heated, thereby forming an adhesive layer (4) as shown in FIG.
) A regular mesh-shaped cell space (5) expanded by gas generated from the pyrolysis gas generating material layer (3) sealed with
is formed, and buffer cells (6) are formed in an uneven manner on the base material (Al) facing the base material (N soil material layer (3). In this way, the pyrolysis gas generating material layer (3) The height of the cell space (5) formed in the coated part is uneven in the range of 1 to 109 times higher than the non-coated part.Furthermore, the base material maintains dimensional stability and strength. In order to
Use a laminated material such as metal foil such as aluminum or non-woven fabric for a part of the material. In addition, the sheet of the present invention is shown in FIG.
On the surface of the substrate (A), the unevenness forming cells (6
) In addition to the cushioning sheet having a structure in which a base material (B
) Includes structures in which cells (6) are formed on both the front and back surfaces.

To explain the manufacturing method of the cushioning sheet of the present invention, a plastic film base material (a material in which a pyrolysis gas-generating inorganic compound is dispersed in a resin liquid binder on a gradient) is coated in a regular halftone pattern by gravure coating. After coating and drying at low temperature, a cross-linking reaction curing adhesive is applied to the non-applied portion of the substrate in a reverse halftone dot pattern of the regular halftone dot pattern by another gravure coating means,
After drying with low-temperature air, the adhesive is cured while bonding the adhesive-coated surface of the base material (AJ) to another plastic film base material (B) under pressure and heat. The generated substances are thermally decomposed to generate gas,
This is a method for manufacturing a cushioning sheet characterized by forming a dot-shaped cell space between a base material (N) and a softened base material (B1).

The plastic film base material of the cushioning sheet of the present invention (N is a normal polyethylene film, ethylene-vinyl acetate copolymer resin film, polypropylene film, polyamide film, polyester film, etc., and a laminate of these may also be used) In addition, metal, foil,
Alternatively, laminates with non-woven fabrics etc. may also be used.

Next, the pyrolytic gas generating inorganic compound and resin binder that constitute the gas generating substance layer (3) will be explained in detail. Ammonium bicarbonate (decomposition start temperature about 60℃, generated gas CO2, B20.'267m119.), which is an inorganic compound lower than the softening temperature, ammonium carbonate (decomposition start temperature about 40℃, generated gas CO2)
2, NH,, B20.700m1/9) ammonium bicarbonate (decomposition start temperature approximately 36°C, generated gas C02, NH,
, B20.570WLl/g) or a mixture thereof. The resin binder is used to adjust the coating viscosity and improve the coating performance when dispersed in the solvent of the pyrolysis gas generating inorganic compound, and is used to adjust the coating viscosity and improve the coating performance. Vinyl acetate copolymer, cyclized rubber, chlorinated rubber, chlorinated polypropylene, urethane, etc., or a mixture thereof is used, and the pyrolysis gas generating inorganic compound and resin binder are dispersed in a hydrocarbon solvent. . The prepared coating liquid is applied in a pattern using a conventional gravure coating method.

Furthermore, the cross-linking reaction curing adhesive applied to areas other than the gas generating substance layer (3) area of the base material (11) is applied by a gravure coating method using an ordinary urethane-isocyanate-based reactive adhesive. At this time, the adhesive is applied continuously so as to surround the regular halftone dot pattern made of the pyrolysis gas generating inorganic compound/resin binder that has been applied previously, and the adhesive is There must be a device for sealing off the gas generated.

The base material (B) used in the present invention is 1. Any of low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer resin, ionomer resin, and ethylene-propylene copolymer resin, each having a Vikato softening point measured by Tl5K7206 in the range of 70°C to 95°C, or
Compounds of these and laminates of these materials are also applicable. The base material (A) and the base material fB) are laminated by the usual dry lamination method. At the same time as softening, the pyrolysis gas-generating inorganic compound is decomposed and the part where the gas-generating substance (3) is applied between the base material (AJ and the base material (B)) expands and forms cells.
Of course, it is also possible to form cells by further heating separately after bonding the base material (N) and the base material (B).

The method for manufacturing the cushioning sheet of the present invention will be explained in more detail with reference to examples. For example, using the apparatus shown in FIG.
Using a gravure plate 0υ′ made into a halftone dot pattern, it was coated with a gravure coating device Qυ, and then dried in a dryer (7
)' and dried. Next, gravure plate Q2, which was made in a reverse pattern to the above-mentioned gravure plate (old)'
Using 1”Y, apply the base material (
The cross-linking adhesive layer (4) is gravure coated on the non-coated portion of 1), and after drying by passing through a hot air blower (7), the base material (2) is coated with a layer for pressurization and lamination. The material is pasted between heating rolls (8) and (8) to produce a cushioning sheet.

The layer corresponding to the base material FB+ can also be supplied onto the base material drawing by the melt extrusion method shown in FIG. The extruded base material (2) and the coated surface of the base material (1), on which the gas generating substance layer (3) and adhesive layer (4) were applied in a pattern in the previous stage, are rolled using pressure rolls (+15) and cooled. The cushioning sheet (91
' can also be manufactured.

The cushioning sheet produced in this way has a high density of cells formed in order to satisfy the cushioning effect, elasticity and handling properties.
It is possible to create unevenness within the range of 19 to 10% from the bonded area, and it also has a cushioning effect with buffer cells formed on both the front and back sides.
IJ's ability is to produce superior W, amphoteric sheets that can be produced efficiently and have arbitrary shapes, which has been difficult with conventional methods.

<Example> Using the apparatus shown in Fig. 4, ammonium carbonate as a pyrolysis gas generating inorganic compound and vinyl chloride-vinyl acetate copolymer resin ( Vinylai, )'VMCH, union carbide g) was mixed and dispersed in a binder dissolved in ethyl acetate, and the weight solids ratio was adjusted to ammonium carbonate/binder resin - 1:1, and the solid content of the entire liquid was 40%. Using a round pattern gravure plate with a depth of microns, it was applied at a coating amount of 2c4/, 1, dried, and then
15013/ 1nch - Using a reverse pattern gravure plate with a depth of 60 microns, apply a two-component curing urethane adhesive (Adco) to the non-coated area of the polyester film.
305/355, Toyo Morton #), and a 10-micron-thick low-density polyethylene film (density 0916, melt index 1.6,
(Vicat softening point: 86°C) i By laminating while heating at 170°C, a cushioning sheet was manufactured. The cell shape of the obtained sheet had a circular bottom and a height of about 2.3 mm, and was sufficient to function as a cushioning sheet.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the cushioning sheet of the present invention and its cross-sectional structure, Figures 2 and 3 are plan views of the process of creating the cushioning sheet of the invention, and Figure 4 is the method for creating the cushioning sheet of the invention. FIG. 5 is an explanatory diagram showing another embodiment of the manufacturing method of the present invention. (1)...Base material A (2)...Base material B (3)...Gas generating substance layer (4)...Adhesive layer (6)...
- Cell (7)...Drying roll (8)...Lamination roll (II... Winding section aυ...Coating device a
2... Coating device α4... T-die film forming device Q61
...Cooling roll patent applicant Toppan Printing Co., Ltd.

Claims (1)

[Scope of Claims] (1) A pyrolysis gas generating material layer (3) in a regular halftone pattern is formed on the surface of the plastic film base material (gradient) or on both the front and back surfaces of the base material (the above-mentioned material of AJ) Layer (3)
A cross-linking reaction-curing adhesive layer (4) in a reverse line dot pattern is formed on the non-coated area, and the adhesive layer (4) is applied to the base material (4) and another plastic film base material (B)'. A cushioning sheet characterized by forming a cell space (5) in which the decomposition gas generated from the material layer (3) is sealed between the base material fA) and the material layer (3). (2+Plastic) A material in which a pyrolysis gas-generating inorganic compound is dispersed in a resin liquid binder is coated onto a film base material in a regular halftone pattern using a gravure coating method, and after drying at a low temperature, the material shown in the diagram of the base material is applied. A cross-linking reaction curing type adhesive is applied to the non-applied area using another gravure coating method in a dot pattern inverse to the regular halftone dot pattern, and after drying with low temperature air, On the other hand, another plastic film base material (BJ
While bonding under Y pressure and heat, the adhesive is cured and the pyrolysis gas generating substance is thermally decomposed to generate gas, forming a halftone dot between the base material (N) and the softened base material (B1). (3) A method for manufacturing a cushioning sheet, characterized in that a part of the plastic film base material (A) is made of gold foil or nonwoven fabric. (4) Pyrolysis gas generating material layer (3) The height of the cell space (5) formed in the coated area is uneven in the range of 1% to 10 degrees higher than that of the non-coated area. Claim 1
Cushioning sheet as described in section. (5) The manufacturing method according to claim 2, wherein the plastic film base material (the base material (Bl layer) bonded on the AI layer is formed by a melt extrusion method.