JPH0673285A - Production of biodegradable foam - Google Patents

Abstract

PURPOSE:To provide a method for producing a biodegradable foam, wherein a vegetable residue, serving as the raw material, can be used without liquefying it and which gives a polyurethane foam scarcely suffering the falling off of the vegetable residue. CONSTITUTION:A polyol component is reacted with a polyisocyanate component in the presence of a vegetable residue, such as coffee grounds, to give a foam. As the vegetable residue, one activated by irradiation with ultraviolet rays or electron beams or by plasma treatment is used.

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 a biodegradable foam using a plant residue such as coffee bean extraction residue.

[0002]

2. Description of the Related Art Polystyrene foam has been widely used as a cushioning material for transporting goods, but in the present day when the problem of disposal after use has been highlighted, the development of biodegradable foam. Is an urgent task.

For such a purpose, various studies have been made on polyurethane compounded with wood materials.

In Japanese Patent Publication No. 509814/1975, lignin is used as a filler for producing a polyurethane foam by reacting an organic compound having an isocyanate group with a polyol in the presence of a foaming agent, a reaction catalyst and a filler. A method of making polyurethane foam using sulfonates is shown.

In JP-A-51-86597, when a polyisocyanate and a polyol are reacted in the presence of a foaming agent, a catalyst, a surfactant, etc., 10 parts of lignin sulfonate are added to 100 parts by weight of the polyol. A method for producing a flame-retardant polyurethane foam, which is added in an amount of up to 150 parts by weight, is shown.

JP-A-57-190014 discloses that a polyhydroxylated sulfite lignin obtained by dissolving solid sulfite lignin in a polyol, a diamine or an alkanolamide and then reacting with an alkylene oxide is used for polyurethane. A polyurethane composition used as one component of a polyol is shown.

Japanese Patent Laid-Open No. 58-96619 discloses a method for producing a polyurethane foam by reacting a polyol and a polyisocyanate in the presence of a catalyst, an additive such as a foaming agent, and the like. A method for producing a polyurethane foam using a lignin-based polyol obtained by adding an epoxide to a lignin derivative is shown.

Japanese Unexamined Patent Publication No. 61-171744 discloses a wood-based foam obtained by foaming and hardening a solution of chemically decorated wood dissolved in an organic solvent having an active group capable of polymerizing, and a method for producing the same. It is shown.

JP-A-64-35528 discloses that a wood material is dissolved in an organic solvent having an active group capable of polymerizing in the presence of an anhydride of a dibasic acid, and a cross-linking agent or a curing agent is added to the wood solution. , And, if necessary, a foaming agent is added to foam and harden the wood-based foam.

Japanese Unexamined Patent Publication (Kokai) No. 64-45440 discloses that a wood material is dissolved in an organic compound having an active group capable of polymerizing, and a substituent is introduced into the hydroxyl group of the obtained wood solution to chemically decorate it. There is disclosed a method for producing a wood-based foam in which a medicinal-chemically-decorated wood solution is foamed and cured. The organic compound having an active group capable of polymerizing is polyhydric alcohols, phenols, bisphenols, etc., and the cross-linking agent or curing agent for polymerizing,
When the organic compound is a polyhydric alcohol, it is a polyvalent isocyanate compound, a polyvalent glycidyl compound, a melamine derivative or the like.

Japanese Unexamined Patent Publication No. 1-298823 discloses a polyurethane containing a cellulosic material, a hemicellulose material or a lignin material as a hard segment. In this case, a polyol compound may be used in combination as the soft segment.

849 of "Paper and Paper Cooperative Magazine, Vol. 44, No. 8"
On page 855, a paper entitled "New Polyurethanes from Plant Materials" is published, in which kraft lignin, sorbosis lignin, eucalyptus lignin or wood flour is liquefied and then reacted with polyisocyanate to produce polyurethane. ing.

[0013]

Among the above, the method of liquefying a wood material as a polyol component and reacting it with a polyisocyanate component to form polyurethane requires complicated steps for liquefying the wood material. However, there is a problem that the cost becomes high.

This method is also limited in that only the liquefiable portion of the wood material can be used. Since the purpose of developing biodegradable foam is not only to prevent pollution when the foam is discarded, it is also important to effectively use a large amount of waste by-product such as plant extraction residue. ,
The availability of only part of the wood material means that the intended purpose cannot be fully achieved.

Of the above methods, the method of using a wood material as a filler in the production of polyurethane is preferable from the viewpoint of effective utilization of waste by-produced in a large amount such as plant extraction residue. However, since wood materials do not substantially react with polyisocyanate, they do not exhibit the action as polyols,
It is merely mixed in the foam as a filler.
Therefore, there is a problem that the wood material as a filler easily falls off from the obtained foam, and this foam is not necessarily suitable for use as a cushioning material.

Under such a background, the present invention makes it possible to use the plant residue as a raw material without liquefying the plant residue, and to prevent the plant residue from falling off when it is made into a polyurethane foam. It is an object of the present invention to provide a method for producing a biodegradable foam.

[0017]

The method for producing a biodegradable foam of the present invention comprises the steps of reacting a polyol component and a polyisocyanate component in the presence of a plant residue to obtain a foam, wherein the plant residue is UV rays. It is characterized by using a plant residue activated by irradiation treatment, electron beam irradiation treatment or plasma treatment.

The present invention will be described in detail below.

The present invention is to obtain a foam by reacting a polyol component and a polyisocyanate component in the presence of plant residues.

[0020] As plant residues, those which have been conventionally poorly disposed, for example, extraction residues of coffee beans, extraction residues generated in the process of sugar production, extraction residues generated in the process of producing food oil,
The extraction residue obtained by extracting and removing useful components from plants such as tea leaves is preferably used. In addition to the extraction residue, wood flour,
Bamboo powder, pulp, walnut husk, rice husk, buckwheat husk, palm husk, bean husk and the like can also be used. In addition, it is desirable to use crushed and dried plant residues.

In the present invention, a plant residue activated by ultraviolet irradiation treatment, electron beam irradiation treatment or plasma treatment is used as the plant residue.

The ultraviolet irradiation treatment is carried out by using a lamp such as a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp or a chemical lamp. The electron beam irradiation treatment is performed by using an electron beam accelerator, and an acceleration voltage of 300 keV or less is sufficient. Examples of the plasma treatment include corona discharge treatment and blow discharge treatment. In either case, preliminary experiments are conducted to obtain the optimum irradiation dose.

The polyol component is a polyhydric alcohol (ethylene glycol, diethyl glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylene glycol, 1,4-butanediol). , 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, etc.), polyester polyol, polyether polyol, polybutadiene polyol or hydrogenated product thereof, polyolefin polyol, castor oil or castor oil derivative-based polyol, alkylene of bisphenols Oxide adducts, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine and the like are used.

As the polyisocyanate component, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, diphenyl sulfone diisocyanate, triphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 3-isocyanate methyl-3,5,5- Trimethylcyclohexyl isocyanate, 3-isocyanate ethyl-3,
5,5-trimethylcyclohexyl isocyanate, 3
-Isocyanate ethyl-3,5,5-triethylcyclohexyl isocyanate, diphenylpropane diisocyanate, phenylene diisocyanate, cyclohexylylene diisocyanate, 3,3'-diisocyanate dipropyl ether, triphenylmethane triisocyanate, diphenyl ether-4,4'-diisocyanate, Alternatively, dimers and trimers of these polyisocyanates can be used.

In reacting the polyol component and the polyisocyanate component in the presence of the plant residue, the plant residue is blended with either or both of the polyol component and the polyisocyanate component, but it is generally blended with the polyol component side. Target.

The compounding amount of the plant residue can be set in a wide range, but it is often 5 to 60 parts by weight based on 100 parts by weight of the total amount of the polyol component and the polyisocyanate component. When the amount of the plant residue blended is extremely small, the meaning of blending the plant residue is lost. On the other hand, when the blending amount of the plant residue is extremely large, the physical properties of the obtained polyurethane foam will deteriorate.

A foaming agent is used in the urethanization reaction. As the foaming agent, water, carbon dioxide gas, air, hydrocarbon, methylene chloride or the like is used. CFCs or alternative CFCs can be used, but only those of the permitted type should be used. A thermal decomposition type foaming agent such as azodicarbonamide, ammonium carbonate or sodium bicarbonate can also be used.

Other compounding agents such as foam stabilizers, solvents, reactive diluents, fillers, pigments, antioxidants, leveling agents, dispersants, antisettling agents, wetting agents, thickeners, preservatives and deodorants. A foaming agent, a flame retardant, an ultraviolet absorber and the like can be added as required.

Although the biodegradable foam of the present invention is particularly useful as a cushioning material, it is also useful as a heat insulating material, a building material, a molded product, a core material, a container and the like.

[0030]

[Function] Even when a foam is obtained by reacting a polyol component and a polyisocyanate component in the presence of a plant residue, the plant residue practically does not react with the polyisocyanate component, so the plant residue falls off from the foam during use. Cannot be prevented.

However, if a plant residue activated by ultraviolet irradiation treatment, electron beam irradiation treatment or plasma treatment is used as the above-mentioned plant residue, such drop-off can be effectively prevented. The reason is considered to be that the surface of the plant residue is activated by the above activation treatment to form a reactive OH group, and the OH group chemically reacts with the polyisocyanate component. It is also considered that the above-mentioned activation treatment makes the surface of the plant residue porous and causes the entanglement with the produced polyurethane.

The presence of plant residues contributes to imparting biodegradability to the foam and reducing the cost of the foam, and also has an advantageous effect on the shape retention of the foam and the mechanical strength of the foam. .

[0033]

EXAMPLES The present invention will be further described with reference to examples. Hereinafter, “parts” means parts by weight.

Example 1 The extraction residue of coffee beans generated in a canned coffee manufacturing plant was dried and pulverized into a fine powder, which was then spread on a support film and irradiated with ultraviolet rays from a high pressure mercury lamp while traveling on a belt. Irradiated.

The molecular weight of 25 parts of the fine powder after ultraviolet irradiation was 1
It was put into 25 parts of polypropylene glycol of 000 and well stirred to obtain a polyol component containing a residue.

Next, 50 parts of the above residue-polypropylene glycol mixture, 50 parts of polymerized MDI (diphenylmethane diisocyanate) as an example of polyisocyanate component, 1.2 parts of water as a foaming agent, 0.6 part of a silicone type foam stabilizer, and as a catalyst. 0.2 parts of dibutyltin dilaurate of was mixed and stirred vigorously, and left at room temperature. The mixture self-heated and foamed to give a dark brown foam with a specific gravity of 0.045.

The obtained foam was cut into the shape of a cushioning material for transportation of precision equipment. This product had the strength and elasticity suitable for a cushioning material, and no residual powder was separated from the foam during the cutting and the actual use as a cushioning material.

When the buffer material thus produced was buried in soil and observed for its collapsed state, partial collapse was already observed after 1 month, and after 3 months, the collapse was almost completed.

Example 2 The extraction residue of coffee beans generated in a canned coffee manufacturing plant was pulverized and dried into a fine powder, which was then spread on a support film and run on a belt by an electron beam accelerator. It was irradiated with an electron beam.

The molecular weight of 25 parts of the fine powder after electron beam irradiation was 4
It was put into 25 parts of polyethylene glycol of No. 00 and well stirred to obtain a polyol component containing a residue.

Next, 50 parts of the above residue-polyethylene glycol mixture, 50 parts of polymerized MDI (diphenylmethane diisocyanate) as an example of a polyisocyanate component, 1.2 parts of water as a foaming agent, 0.6 part of a silicone type foam stabilizer, and as a catalyst. Polyamide polyamine
0.2 part was mixed, stirred vigorously and left at room temperature. The mixture self-heated and foamed to give a dark brown foam with a specific gravity of 0.048.

The obtained foam was cut into the shape of a cushioning material for transportation of precision equipment. This product had the strength and elasticity suitable for a cushioning material, and no residual powder was separated from the foam during the cutting and the actual use as a cushioning material.

When the collapsed state was observed by burying the buffer material thus produced in the soil, a partial collapse was already observed after 1 month, and the collapse was almost completed after 3 months.

Example 3 The same effect as in Example 1 was obtained by repeating Example 1 except that corona discharge treatment was carried out in place of the ultraviolet irradiation treatment.

[0045]

INDUSTRIAL APPLICABILITY In the present invention, since the plant residue can be used without liquefying, a complicated process for liquefying can be omitted altogether, and a foam can be produced at low cost.

Further, since the whole amount of the plant residue can be used, the waste produced as a large amount can be effectively used.

The present invention has the characteristic effect that the plant residue is effectively prevented from falling off from the foam.

The presence of plant residues imparts a favorable biodegradability to the foam, so that even if the foam is discarded by other than the proper processing route, it will eventually collapse and disappear. . Also, when this is incinerated, the incineration is performed smoothly.

The presence of plant residues indicates the shape retention of the foam,
It also has an advantageous effect on the mechanical strength of the foam.

[Procedure amendment]

[Submission date] September 24, 1992

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009] JP 64-3 66 28 No., the presence of the wood material anhydrides of dibasic acids, wood solution in an organic solvent having a polymerization capable active groups, the crosslinking agent or A method for producing a wood-based foam in which a curing agent and, if necessary, a foaming agent are added and foam-cured is shown.

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Claims (2)

[Claims] 1. When obtaining a foam by reacting a polyol component and a polyisocyanate component in the presence of a plant residue, as the plant residue, a plant residue activated by ultraviolet irradiation treatment, electron beam irradiation treatment or plasma treatment is used. A method for producing a biodegradable foam characterized by being used. 2. The production method according to claim 1, wherein the plant residue is an extraction residue obtained by extracting and removing useful components from plants.