JPH0931232A - Cushioning/heat-insulating material prepared by foaming cellulosic substance and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cushioning heat insulating material, extremely useful as a cushioning material due to its great shock absorbing power, having ultrahigh heat insulating effects due to the formation of innumerable pores in the interior thereof, capable of not only being decomposed more rapidly than usual cellulosic materials in the nature and causing no pollution problem but also preventing the pollution in recycling and utilization of waste resources and utilizable as the so-called green product for a packaging secondary material for exported merchandise and a method for producing the material.

SOLUTION: A cellulosic material is beaten and dehydrated and a usual water-soluble adhesive and a usual foaming agent are added thereto and expanded into a desired form by a wet process. The resultant foam is subsequently dried to produce a cushioning heat insulating material.

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buffer heat insulating material in which a cellulosic material is foamed and a method for manufacturing the same.

[0002]

BACKGROUND OF THE INVENTION In the packaging of goods, cushioning material is an important auxiliary material used for preventing damage and deformation of goods during transportation and storage.

Such a cushioning material must be elastic or shock-absorbing in itself.

Conventionally, a plastic material has been foamed and used as such a buffer material. For example, polyethylene (PE), polypropylene (PP), ethylene vinyl acetate copolymer (EVA), polystyrene (P
S), modified EVA, soft PVC, phenoxy resin, butadiene resin or other foamed plastic material obtained by foaming; or natural rubber, SBR rubber, styrene-butadiene thermoplastic rubber, butadiene rubber ( BR), isoprene rubber (IR), ethylene-
Propylene copolymer rubber (EMP), polychloropropylene rubber (CR), butyl rubber (IIR), urethane rubber, silicone rubber, acrylic rubber, chlorosulfonated styrene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, propylene oxide rubber The elastic bodies such as ethylene vinyl acetate rubber and thermoplastic rubber have been used, or the cushioning bodies obtained by foaming foreign substances have been used.

Of these, inexpensive polyethylene foams or polystyrene foams have been widely used.

However, although such plastic substances and / or rubber substances have excellent characteristics as cushioning materials, they do not decompose in the natural environment and thus cause environmental pollution, and in particular, they burn. Since it emits toxic gas at times, industrialized countries have already banned the use of these plastic foams or cushioning materials of natural or synthetic rubber materials, and their use will be regulated worldwide under the green round in the future. I have no choice.

In order to solve such a problem,
It is also used as a cushioning material by directly molding pulp or a cellulose material or the like.

However, such a cushioning material has been restricted in its use because its shock absorbing power is lowered and it cannot fully serve as a cushioning material.

Examples of such a cushioning material made of a cellulose material include those described in the following US patent specifications.

US Pat. No. 5,230,943 describes a free-flow cushioning filler having a non-planar dish shape.

US Pat. No. 4,937,131 describes a flexible cushioning filler obtained by processing a roll-shaped sheet material such as biodegradable paper.

US Pat. No. 5,312,665 discloses a loose unit composed of a plurality of filler units, each filler unit having at least two paper rings joined together with their outer ring surfaces in contact. -Fill filler is described.

US Pat. No. 5,308,677 discloses a flat base having an arcuate or geometric cross section and a plurality of bases cut out from one side of the base to project in opposite arcs. The packaging stuffing which consists of the convex part of is described.

In US Pat. No. 5,173,352, a plurality of elongated strip-shaped paper materials having natural elasticity are compressed in the longitudinal direction by folding the paper material a plurality of times so as to traverse the natural elasticity. An elastic filler produced by the above is described.

US Pat. No. 5,151,312 discloses a lightweight, non-fitting peanut-like filler obtained by recycling and molding newspaper, which has a hollow double-walled shell structure,
Preferably, a cup-shaped structure is described, which has a flange, an opening and an integrally molded double wall separator.

US Pat. No. 5,213,867 describes a regular tetrahedral loose-fill filler made of paper.

US Pat. No. 4,566,831 describes a shock absorbing buffer in which a water-reduced wood flour filler is sealed in the jacket.

US Pat. No. 4,109,040 describes a cushioning filler having a relatively dense structure which is manufactured using a sheet material such as rolled paper.

However, a cushioning material having a cushioning and heat insulating effect produced by directly foaming a cellulosic material such as pulp or waste paper (paper waste) has not been developed so far.

[0020]

DISCLOSURE OF THE INVENTION The present invention provides a cushioning material which exhibits a cushioning and heat insulating effect obtained by directly foaming a cellulosic material such as pulp or waste paper (paper waste), and a suitable manufacturing method thereof. The purpose is to

[0021]

SUMMARY OF THE INVENTION As a result of years of research, the present inventors have found that cellulosic materials such as waste newspaper or other waste paper or pulp, along with conventional foaming agents and conventional water-soluble adhesives. If it is wet-foamed and dried, it can be foamed to about 120 to 500% of the original volume of the cellulosic material, and the foamed cellulosic foamed in this way has a very large impact absorption, and thus is a cushioning material. As a result, the present invention has been completed by discovering the surprising fact that a large number of pores are formed in the interior, so that the heat insulating effect is also very high.

In addition, the buffer heat insulating material using the cellulosic material produced as described above not only has extremely excellent buffering effect and heat insulating effect, but also has numerous pores formed therein, so that it is natural. Not only does it decompose much faster than ordinary cellulosic substances and does not cause pollution problems, but it can also prevent pollution by recycling and utilizing waste resources, and is also compatible with the Uruguay Round, so-called green products (Green products). It can be widely used as a supplementary material for packaging of exported products.

Accordingly, it is an object of the present invention to provide a buffer utilizing a cellulosic material obtained by foaming the cellulosic material with an adhesive and a foaming agent to a desired suitable volume and drying.
It is to provide thermal insulation.

Another object of the present invention is to provide a method for producing a cushioning and heat insulating material using a cellulosic material by foaming and drying the cellulosic material together with an adhesive and a foaming agent.

That is, according to the present invention, a buffer heat insulating material is produced by beating and dehydrating a cellulosic material, adding a conventional water-soluble adhesive and a conventional foaming agent thereto, and foaming them in a desired form by wet-drying and drying. Is provided.

Further, in the present invention, after the cellulosic substance is beaten and dehydrated, a usual water-soluble adhesive and a usual foaming agent are added thereto, and the mixture is wet-foamed in a desired form and dried to produce a buffer heat insulating agent. It provides a way to do it.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Cellulose substances usable in the present invention include pulp, waste paper and other ordinary cellulosic substances.

Adhesives that can be used in the present invention include starch paste, sodium carboxymethyl cellulose, ethyl cellulose, methyl cellulose, sodium alginate, casein, gelatin, polyvinyl alcohol (PVA),
Polyvinyl acetate (PVAc) and other ordinary water-soluble adhesives can be used alone or in combination of two or more.

The amount of these adhesives used may vary depending on the type of adhesive, adhesive strength, etc., but is usually 0.1 to 20%.
(Weight) can be used.

In the present invention, a conventional foaming agent is used for foaming. As a foaming agent, azodicarbonamide (ADCA), azobisformamide (ABFA), azobisisobutyronitrile (AIB)
N), dinitrosopentamethylenetetramine (N, N'-di
nitroso Pentamethylene Tetramine; DPT), p-
Toluenesulfonyl hydrazide (p-Toluenesulfonylhyd
razide; TSH), p, p'-oxybis (benzenesulfonyl) hydrazide (p, p'-Oxybis (benzenesulfo
Organic foaming agents such as nyl) hydrazide; OBSH) and inorganic foaming agents such as ammonium carbonate and sodium hydrogen carbonate can be used.

The amount of these foaming agents used may be 0.5 to 20% (weight) based on the total weight. The cellulose substance can be used as it is. In the case of waste paper, foreign substances are removed, beaten, and dehydrated before use. The water content after dehydration is about 30%. 50 pieces of this waste paper
-80% (by weight) is used.

Moisture content in the manufacturing process is 10-30%
(Weight).

This can be represented by the following steps.

1. Pulping process: (When using waste paper) A process of crushing various waste papers with water to produce pulp.
When pulp is used, it is used as it is, and this step is omitted.

2. Screening step: (When waste paper is used) A step of selecting and removing various impurities (various plastic substances such as vinyl, iron powder, impurities in soil or sand) from the pulp produced in the first step. If pulp is used, this step is omitted.

3. Refining
Step: A step of making the pulp obtained in the second step into a finer fiber. This step may be omitted depending on the used waste paper.

4. Dehydration step: The water content obtained in the second step (when the third step is omitted) or the water content obtained in the third step is dehydrated by a dehydrator to have a water content of about 10-30%.
Dewater with a normal dehydrator to (weight).

5. Mixing step: Mix the pulp obtained in the fourth step or pure pulp with a water-soluble adhesive, a foaming agent or water if necessary.

6. Preheat Step The mixture obtained in Step 5 is preheated to about 30-90 degrees Celsius. (When ammonium carbonate is used as a foaming agent, it is preheated at a low temperature, and when a foaming agent having a relatively high decomposition temperature is used, it is preheated at a high temperature.) Molding and secondary foaming process: The preheated mixture obtained in the 6th process is put into a molding frame having a desired shape, and about 70-150.
Heat at a temperature (Celsius) to mold and foam. When ammonium carbonate having a low decomposition temperature is used as a foaming agent, it can be foamed at a low temperature.

8. Drying process: The molded and foamed product obtained in the seventh process is dried to produce a foam.

[0041]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples of the present invention and Comparative Examples thereof, but the present invention is not limited to these Examples.

Example 1 1 kg of waste paper is put into about 600 ml of water and beaten. Various impurities are removed from the beaten waste paper material and dehydrated to a water content of about 30% (by weight).

Separately, about 20 g of gelatin is dissolved in water at about 60 ° C. to have a concentration of about 30% (by weight). About 2 g of sodium carboxymethyl cellulose (Sodium CMC) is dissolved in water to a concentration of about 3% (by weight). The gelatin solution and the sodium CMC solution are mixed, and about 10 g of azobisisobutyronitrile (AIBN) as a foaming agent is mixed with the beaten waste paper, and the whole is heated to about 85 degrees.
Pour the heated mixture into a constant molding frame,
Heat to form and foam. The foamed product is dried in a drying oven to produce a foamed product that is foamed at about 150% (volume).

Example 2 Water was added to 1 kg of pulp to adjust the water content to about 25%. Separately, 30 g of sodium alginate was dissolved in water and adjusted to a concentration of about 20% (weight) and then mixed with pulp, and about 3 g of ammonium carbonate was dissolved in cold water to about 10% (weight), Mix homogeneously into the pulp. The mixture is heated to about 40 degrees and placed in a molding frame for about 8
Approximately 200% by heating to 0 degree, molding, foaming and drying
A foamed product foamed to (volume) is produced.

Example 3 1 kg of waste paper is put in about 600 ml of water and beaten, and then various impurities are removed and dehydrated so that the water content becomes about 30%. Separately, 30% of starch is put in 100 ml of hot water and boiled to remove the starch paste and cooled, and then 10 g of azobisformamide (ABFA) is mixed as a foaming agent. This mixture is mixed with pulp. Next, after heating at about 90 degrees, it is put into a molding frame and heated at about 150 degrees to mold and foam. The foamed product is dried in a drying oven to produce a foamed product expanded to about 200% (volume).

Other foaming agents and adhesives were also used in Examples 1-3.
Can be carried out to produce an expanded cellulosic product.

In order to produce a rigid foam, the amount of the adhesive used may be reduced or the degree of foaming may be reduced, and in order to produce a soft foam, a large amount of the foaming agent may be added. It is also possible to increase the degree of foaming or reduce the amount of adhesive used.

[0048]

INDUSTRIAL APPLICABILITY The cellulosic material foam produced by the method of the present invention is not only good in elasticity but also light in weight and has an excellent heat insulating effect, and can be used as various cushioning materials and heat insulating materials.

The foam of the present invention is harmless to the human body and not only uses a biodegradable cellulosic material,
The adhesive used is also harmless to the human body, and the foams used are all harmless to the human body converted into a nontoxic gas.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Yu Yi Park, 203-49, Neonnai 2-dong, Koto-ku, Seoul, Republic of Korea

Claims (6)

[Claims] 1. A buffer heat insulating material produced by beating and dehydrating a cellulosic material, and then adding an ordinary water-soluble adhesive and an ordinary foaming agent thereto, followed by wet foaming into a desired form and drying. 2. After solidifying and dehydrating the cellulosic material, a conventional water-soluble adhesive and a conventional foaming agent are added thereto, and the desired volume is foamed to 120 to 500% of the original volume and dried. The manufactured buffer insulation material according to claim 1. 3. A cellulosic substance is beaten and dehydrated, and then a starch paste, sodium carboxymethyl cellulose, ethyl cellulose, methyl cellulose, sodium alginate, casein, gelatin, polyvinyl alcohol (PVA), polyvinyl acetate (PVA) as a water-soluble adhesive is added thereto.
Vac) one or more water-soluble adhesives and azodicarbona as a conventional blowing agent (Azodicarbona
mide; ADCA), Azobisformamide
amide; ABFA), azobisisobutyronitrile (A
zobisisobutyronitrile; AIBN), dinitrosopentamethylene tetramine (N, N'-dinitroso Pentamethy)
lene Tetramine; DPT), p-toluenesulfonylhydrazide, p, p '
-Oxybis (benzenesulfonyl) hydrazide (p,
p′-oxybis (benzenesulfonyl) hydrazide ； OBS
The buffer heat insulating material according to claim 1 or 2, which is produced by adding at least one foaming agent selected from H), ammonium carbonate and sodium hydrogen carbonate, foaming it in a wet manner and drying it. 4. A method for producing a buffer heat insulating material, which comprises beating and dehydrating a cellulosic material, adding an ordinary water-soluble adhesive and an ordinary foaming agent thereto, and foaming in a desired form by wet and drying. 5. A buffer insulation material, which is prepared by beating and dehydrating a cellulosic material, adding a water-soluble adhesive and a conventional foaming agent, foaming it to a desired volume of 120 to 500% of its original volume, and drying. The method according to claim 4, which comprises: 6. Paper waste (waste paper) is beaten and dehydrated, and then starch paste, sodium carboxymethyl cellulose, ethyl cellulose, methyl cellulose, sodium alginate, casein, gelatin, polyvinyl alcohol (PVA) is used as an ordinary water-soluble adhesive. , One or more water-soluble adhesives selected from polyvinyl acetate (PVAc) and azodicarbonamide (Azodicar) as usual foaming agent
bonamide; ADCA), azobisformamide (Azob
isformamide; ABFA), azobisisobutyronitrile (AIBN), dinitrosopentamethylenetetramine (N, N'-dinitroso Pent)
amethylene Tetramine; DPT), p-toluenesulfonylhydrazide, p,
p'-oxybis (benzenesulfonyl) hydrazide (OBS)
A process according to claim 4 or 5, wherein a conventional foaming agent selected from H), ammonium carbonate and sodium hydrogen carbonate is added and foamed in the desired form to 120 to 500% of the original volume to produce a buffer insulation. .