JPS61178865A - Sheet for cushioning - 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 (Technical Field) The present invention relates to a cushioning sheet provided with a foam layer that is housed in an individual package together with a container for cosmetics or the like.

(Prior Art) Foamed sheets made of polystyrene, polypropylene, polyethylene, polyurethane, etc. have been used as cushioning members together with individual containers for cosmetics and the like. However, because these materials are bulky and have soft characteristics, they are difficult to fit into automatic packaging machines and must be manually packed into individual packages, which reduces work efficiency in the packaging process. It was also a factor in reducing this.

Also, when stored together with containers for cosmetics, etc. in individual packaging,
The above-mentioned foam sheets are not only bulky, but also tend to be wasteful, and are not necessarily satisfactory in terms of appearance.

Therefore, as a result of intensive research in view of the above circumstances, the inventors of the present invention printed desired characters and designs with foam ink on a slightly thick sheet such as paperboard, and formed a foam layer at appropriate locations. , has a beautiful appearance and shape, and exhibits an effective buffering effect. Furthermore, they found a buffer sheet suitable for automatic packaging machines and completed the present invention.

(Objective of the Invention) That is, the present invention is unprecedented in that it forms desired letters and designs three-dimensionally with a foam layer, exhibits a beautiful appearance, has an effective cushioning effect, and is suitable for automatic packaging machines. To provide a buffer sheet having good properties.

(Effects of the Invention) The buffer sheet of the present invention includes a foam layer with desired characters and designs formed by printing the sheet with foam ink and then subjecting the sheet to heat treatment.

(Specific Structure of the Invention) The sheet according to the present invention is a slightly thick sheet made of pulp, various types of fibers, plastic, metal, etc., and is a composite paper or laminated paper made of a combination of these materials. It's okay. Preferably, for example in the case of pulp paper, the thickness is 0.2
~0.5 tm and weighs 50 to 460 y/door.

In addition, foamed ink is made of thermally foamable resin particles and well-known vinyl.
Acrylic acid ester Kyodo 7~: Marujien.

It is composed of an aqueous emulsion type print binder such as a polyacrylic acid ester emulsion, or an organic solvent type print binder made of a thermoplastic resin and a drying organic solvent that does not attack the heat-foamable resin particles.

Thermal foamable resin particles are particles of a thermoplastic resin with low gas permeability that includes or contains a well-known expansion agent, and the particle size is 1 to 500 μm, preferably 5 to 100 μm, and the shape is approximately spherical. Preferably. In addition, the content of the swelling agent is 10 to 2 if the swelling agent is a low-boiling liquid swelling agent described below.
0 weight % (hereinafter, weight % is abbreviated as wt %), and 20 to 50 wt % is suitable for decomposable expansion agents.

Low-boiling liquid expansion agents include propane, butane, isobutane,
Pentane, impentane, neopentane.

Low-molecular hydrocarbons such as hexane and heptane, 10-genated hydrocarbons such as trichloromonofluoromethane, dichlorodifluoromethane, and dichlorotetrafluoroethane, and petroleum ethers are used as decomposable expanding agents. 2
, 2'-azobisisobutyronitrile, azodicarbonamide, azocarboxylic acid dialkyl ester, diazoaminobenzene.

Paratoluenesulfonyl hydrazide, sodium bicarbonate, ammonium bicarbonate, etc. are chemically thermally decomposed to generate gas, and are applied together with a decomposition accelerator if necessary.

Polymer resins with low gas permeability such as polyvinylidene chloride, polyacrylonide, lyl, polyester, polyamide, polyurethane, and polycarbonate are used as thermoplastic resins, and for the purpose of modification, divinylbenzene is used. , esters of methacrylic acid, esters of acrylic acid.

Vinyl acetate, vinyl chloride, styrene, etc. are applied together with various polymerization initiators and stabilizers. In order to obtain the thermally foamable resin particles, for example, a low-boiling point liquid expanding agent and a thermoplastic resin monomer may be mixed and polymerized under pressure, or a decomposable expanding agent and a thermoplastic resin may be mixed together. After mixing and dissolving in a solvent, the resin precipitated in a non-solvent may be pulverized.

The type of resin in the print binder, the resin content, and the content of expandable resin particles in the print binder are appropriately adjusted depending on characteristics such as adhesion to the sheet, thickness of the foam layer, and strength of the foam membrane. Generally, the resin content in the print binder is preferably 20 to 50 wt%, and the content of expandable resin particles is preferably 10 to 50 wt%.

Here, in the present invention, particularly preferred foaming inks include:
Expanding agents are butane, isobutane, and pentane.

It is at least one type of impentane, and is a copolymer resin whose main components are vinylidene chloride and acrylonitrile, and whose thermoplastic resin has a swelling agent content of 10 to
It is contained in an aqueous emulsion type print binder having a particle size of 5 to 5 wt % and a particle size of 20 to 50 wt %.

The above thermally foamable resin particles are heated at a temperature of 110 to 140°C for 5 seconds to
When heated for 1 minute, the particle size expands 4 to 5 times, and the foamed ink printed on a heat-shrinkable sheet has
Similarly, its thickness expands 5 to 15 times.

In addition to the above, the foamed ink also contains pigments 9 that exhibit various tones.
Colorants such as dyes, stabilizers, viscosity modifiers, etc. can be blended (Examples of the Invention) The present invention will be explained below with reference to Examples.

Example 1 An explanation of how to use Foundation Cake A (4), efficacy, etc. was printed on one side of a sheet of slightly thick pulp paper m (2s O?/rd). (Usage manual) Next , thermally foamable resin particles that are vinylidene chloride-acrylonitrile copolymer resin with a particle size of 10 to 20 pm and containing butane (15 wt%)...30 wt%, and an aqueous emulsion (resin content) of ethylene vinyl acetate copolymer resin. 4wt%)
...Using a foaming ink consisting of 70 wt%, four letters (2) rAJ are written on the other side of the sheet, 0, 0,
After screen printing to a thickness of 0.04~0.05 decoy, heat treatment is performed for 15~20 seconds in a hot air tunnel at a temperature of 140~150℃ to form a foam layer with a thickness of 0.4~0.5fl. Four letters rAJ were formed on the surface of the sheet.

(See Figure 1) By folding and wrapping the case (4) of the foundation cake A with the sheet (3) above and storing it in the paper bag (5), the contact surface between the sheet (3) and the case (4) Since the foam layer is interposed in the sheet (3), the sheet (3) can serve both as an instruction manual and as a cushioning sheet. (See Figure 2) Also, the sheet (
Since sheet 3) used a slightly thick and hard pulp paper, it was well suited for automatic packaging machines, similar to sheet (3) which did not have a foam layer.

Example 2 The heat-foamable resin particles of Example 1 were modified to contain 2,2'-azobisisobutyronitrile (40 wt%) and have a particle size of 10 to 3.
The thickness was determined in the same manner as in Example 1, except that the 0 μm acrylonitrile-butadiene-methyl methacrylate coelectrolyte tochi resin was used, and the treatment temperature and time for forming the foam layer were 120 to 130°C for 15 to 20 seconds. It was possible to obtain four l-AJ impact sheets (3) each consisting of a foam layer of 0.3 to 0.4 rxx.

(Effects of the Invention) As described above, the cushioning sheet of the present invention has a beautiful appearance by forming desired characters and patterns three-dimensionally in a foam layer, and is effective without being bulky like conventional foam sheets. It has a shock-absorbing effect, and it is possible to reduce the external size of individual packaging. In addition, since a somewhat thick sheet is used, it is compatible with automatic packaging machines and has good workability in the packaging process, reducing costs in terms of both work man-hours and material purchasing. Furthermore, by printing a normal print on one side or both sides of the sheet as an instruction manual, one member can serve both as an instruction manual and as a buffer member.

The buffer sheet of the present invention has an easy manufacturing process and can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a buffer sheet according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the process of wrapping a container for cosmetics or the like with the buffer sheet of the present invention and storing it in an individual packaging bag. fi+...sheet, (2)...foam layer on which the letters rAJ are formed, (
3)...Buffer sheet, (4)...Cosmetic container, (5)...Individual packaging.

Claims (3)

[Claims] (1) A cushioning sheet having a foam layer with desired characters and designs formed by printing foam ink on the sheet and then subjecting it to heat treatment. (2) The buffer sheet according to claim 1, wherein the foaming ink comprises thermoplastic resin particles containing a low-boiling point liquid expansion agent and an aqueous emulsion type print binder. (3) The low-boiling point liquid expansion agent is at least one of butane, isobutane, pentane, and isopentane, and the thermoplastic resin is a copolymer resin mainly composed of vinylidene chloride and acrylonitrile, and the water-based emulsion type print binder The buffer sheet according to claim 2, wherein is an ethylene-vinyl acetate copolymer emulsion.