JPH05214155A - Biodegradable cushioning material and its production - Google Patents

Abstract

PURPOSE:To provide a process for easily producing a biodegradable cushioning material without lowering the extremely excellent cushioning characteristics of foamed polystyrene. CONSTITUTION:The objective cushioning material is a molding composed of primary expanded polystyrene beads and porous cellulose beads bonded with a water-expandable polyisocyanate resin.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a biodegradable buffer material,
And a manufacturing method thereof. For more details,
The present invention relates to a method for producing a biodegradable cushioning material having biodegradability and excellent in cushioning and compressing properties in view of the recent environmental pollution caused by plastic wastes.

[0002]

2. Description of the Related Art A cushioning material is used in an extremely large amount in automobiles, furniture, electricity, construction materials, foods, fisheries / agriculture, and the like. Among the buffer materials used in many of these fields, expanded polystyrene is the mainstream plastic material.

However, the most important reason for environmental pollution due to plastic waste is that many plastics containing expanded polystyrene do not have biodegradability and remain in the soil as they are, thus enormous landfill sites. It is necessary to secure. Even if incinerated, plastics generally have a large amount of heat of combustion, and there is a problem in the quality and amount of combustion gas, so it is difficult to handle with simple equipment such as incineration of lignocelluloses. Therefore, it has been desired to introduce a buffer material having biodegradability or biodegradability, which replaces expanded polystyrene which has been a mainstream of plastic waste as a buffer material.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have aimed to obtain a buffer material having biodegradability, and can easily provide a buffer material without deteriorating the extremely excellent buffer property of expanded polystyrene. It is to develop a new method that can be obtained.

That is, to develop a means by which a cushioning material having an excellent cushioning effect and also having biodegradability can be produced from expanded polystyrene and other expanded beads.

[0006]

The object of the present invention is to use expanded polystyrene beads and porous cellulose beads, and as their binder, an organic polyisocyanate compound and / or its isocyanate group-terminated prepolymer and a polyoxyalkylene addition higher class. This is solved by using a water-foamable polyisocyanate resin obtained by reacting one or more kinds of aliphatic amine derivatives.

[0007]

That is, according to the present invention, the foamed beads as a base material are used for molding and manufacturing a biodegradable buffer material using foamed beads, a water-foamable polyisocyanate resin and / or an additive. Are primary expanded polystyrene beads and porous cellulose beads, and the water-expandable polyisocyanate resin as a binder contains an organic polyisocyanate compound containing two or more isocyanate groups in the molecule and / or its isocyanate group-terminated prepolymer. Polymer and one or more polyoxyalkylene-added higher aliphatic amine derivative represented by dialkoxylate monoalkylamine, trialkoxylate monoalkyldiamine, dialkoxylate monoalkylamide and trialkoxylate monoalkylamidoamine Get by reacting with To a method forming and fabrication of biological disintegration buffer material, characterized by the use of what is.

Substrates that can be used in the present invention are used in a mixed system of expanded polystyrene beads and porous cellulose beads. Expanded polystyrene beads
Mainly contributing to imparting buffering / compressing properties and reducing weight, the purpose of the porous cellulose beads is to utilize the biodegradability of the beads themselves.

Expanded polystyrene beads have a particle size of 1 to 8 m.
m, preferably 3 to 5 mm is used.

As the expanded polystyrene beads themselves, those conventionally produced during the production of expanded polystyrene can be widely used as long as they have the above-mentioned particle size.

The porous cellulose beads used in the present invention have a particle size of 2 to 6 mm, preferably 3 to 4.5.
The typical porous cellulose beads are, for example, Japanese Patent Application No. 2-59452 (JP-A-3-259934) and Japanese Patent Application No. 1-314142.
No. 9 (JP-A-3-170501) and the like can be exemplified. The porous cellulose beads exemplified above are particularly preferable examples, and other beads can be used in the present invention.

It is necessary to use polystyrene beads and porous cellulose beads in combination, and if either one of them is used, the object of the present invention cannot be achieved. Expanded polystyrene beads alone slow biodegradability, and porous cellulose beads alone reduce the buffering effect.

Therefore, the ratio in the case of using both of these is
Normal polystyrene beads: cellulose beads 1: 1
It is 1: 100, preferably 1: 1 to 1:20, and particularly preferably 1: 5 to 1:10 (weight ratio).

The water-foamable polyisocyanate resin used in the present invention is an organic polyisocyanate compound containing two or more isocyanate groups in the molecule and / or its isocyanate group-terminated prepolymer and dialkoxylate monoalkylamine, Obtained from the reaction with one or more polyoxyalkylene addition higher aliphatic amine derivatives represented by trialkoxylate monoalkyldiamines, dialkoxylate monoalkylamides and trialkoxylate monoalkylamide amines.

Examples of the organic polyisocyanate compound for the resin include tolylene diisocyanate, xylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, biphenylene diisocyanate, diphenyl ether diisocyanate having two or more functional groups. Examples thereof include trisine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like. These isocyanate derivatives and the similar compounds can be used alone or as a mixture of two or more kinds.

Further, the isocyanate group-terminated prepolymer is obtained by reacting an organic polyisocyanate compound with a polyol having active hydrogen. As the polyol having active hydrogen, all polyols having at least two or more hydroxyl groups in one molecule can be used, but typical ones are polyester polyol, polyether polyol, epoxy polyol and the like. It is also possible to use a combination of two or more polyols.

Examples of polyester polyols include ethylene glycol, diethylene glycol, triethylene glycol 1,2-propylene glycol, trimethylene glycol, 1,3-butylene glycol,
One or more compounds having at least two hydroxyl groups such as tetramethylene glycol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol and sorbitol, and malonic acid, maleic acid and succinic acid. Acid, adipic acid, tartaric acid, sebacic acid, oxalic acid, phthalic acid, terephthalic acid, azelaic acid, trimellitic acid and the like, one or more compounds having at least two carboxyl groups are used, It can be manufactured by a method. Also included are lactone-based polyester polyols obtained by ring-opening polymerization of monomers having lactones typified by caprolactone and valerolactone.

Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, glycerin, sorbitol,
Alkylene having 2 or more carbon atoms such as ethylene oxide, propylene oxide, butylene oxide and styrene oxide, using one or more compounds having at least two active hydrogens such as sucrose, bisphenol A and pentaerythritol as a polyol starting material. It is produced by addition-polymerizing one or more monomers such as oxide and epichlorohydrin by a conventional method.

In addition, these active hydrogen-containing polyols include the general formula R ₃ O (R ₄ O) _n H (R ₃ : alkyl group, R
₄ : alkylene group) molecular weight of 250 to 4000
Alkoxy polyalkylene glycols of are also included.

The polyoxyalkylene non-higher aliphatic amine derivative used in the present invention has the chemical formula (1):
It is shown by (2), (3) and (4).

[0021]

[Chemical 1]

[0022]

[Chemical 2]

[0023]

[Chemical 3]

[0024]

[Chemical 4]

However, in the formula, R, R ₁ , R ₂ , X ₁ , X ₂ ,
Y ₁ , Y ₂ , Y ₃ , Z ₁ , Z ₂ and n are as follows.

R: a linear or branched alkyl group or hydroxyalkyl group having an average carbon number of 8 to 40 (however, an alkenyl group, a hydroxyalkenyl group, a phenyl group and a group having an ether bond in the carbon chain are also included).

R _{1 is} hydrogen or a methyl group (however, hydrogen and a methyl group may be introduced randomly or in a block form).

R _{2 is} a linear or branched alkyl group or hydroxyalkyl group having an average carbon number of 7 to 39 (however, an alkenyl group, a hydroxyalkenyl group, a phenyl group and a group having an ether bond in the carbon chain are also included).

X ₁ , X ₂ , Y ₁ , Y ₂ , Y ₅ , Z ₁ , Z ₂ : 1
An integer from ~ 350

N is an integer of 2 or 3.

R in the chemical formulas (1) to (4) and the chemical formula (5)

[0032]

[Chemical 5]

The fatty acid residue of is a natural fatty acid residue of vegetable or animal origin. Examples of the natural fatty acid residue of vegetable origin include corn oil, cottonseed oil, peanut oil, rapeseed oil, sesame oil, soybean oil, safflower oil, coconut oil, balm oil, balm kernel oil, etc. Is
Obtained from pork oil, beef tallow oil, sardine oil, herring oil, squid oil, sardine oil, whale oil, etc.

These fatty acid residues from animal and vegetable oils may be used alone or in admixture of two or more.

The following may be used as the additive. For example, a catalyst, a foam stabilizer, and optionally a flame retardant and a viscosity modifier can be used.

Examples of the catalyst include tertiary amines such as dimethylethanolamine, triethylenediamine, tetramethylpropanediamine, tetramethylhexamethylenediamine and dimethylcyclohexylamine, and organic tin compounds such as stannas octoate and dibutyltin dilaurate. Examples thereof include alkoxylate aliphatic quaternary ammonium salt compounds that are said to be effective in promoting the curability of the organic polyisocyanate compound and water.

Examples of the foam stabilizer include various siloxane-polyalkylene oxide block copolymers, the selection of which is determined by the formulation. Examples of the flame retardant include trischloroethyl phosphate, trischloropropyl phosphate, tricrudyl phosphate, chlorinated paraffin and the like.

The water-foamable polyisocyanate resin used in the present invention is a hydrophilic polyisocyanate resin composition having a relatively low viscosity. For this reason, the resin composition of the present invention does not particularly require a viscosity modifier, but may be added and blended depending on the case. However, low-boiling organic solvents such as acetic acid esters and ketones are not preferable from the viewpoints of deterioration of working environment and risk of ignition. Alkylene carbonates and phthalates have high boiling points and flash points, and are preferable as viscosity modifiers.

From the water-foamable polyisocyanate resin used in the present invention, foams having various properties can be obtained. That is, by changing the type of the organic polyisocyanate compound, or by directly modifying the organic polyisocyanate compound with a polyoxyalkylene addition higher aliphatic amine derivative which is a compound in the present invention, or a general-purpose polyether polyol, polyester By changing the type of modifiers for the production of prepolymers such as polyols and the structure and molecular weight of polyoxyalkylene-added higher aliphatic amine derivatives, from soft foams with elasticity to hard foams with rigidity Since the expansion ratio can be arbitrarily adjusted from several times to several tens of times, it is possible to provide the characteristics suitable for the use of the buffer material.

Further, although the obtained water-foamable polyisocyanate resin shows a difference in the degree of degradability depending on the type of the modifier, the degree of modification, the type of the organic polyisocyanate compound, etc., it is biodegradable by the soil burying method. In the test, a weight change of 50% or more was observed in several months, and the buffer material obtained by using the water-foamable polyisocyanate resin of the present invention as a binder was prepared by using non-biodegradable expanded polystyrenes as one of the base materials. Was also confirmed to have considerable biodegradability.

Molding / manufacturing of the cushioning material of the present invention can be generally accomplished by the following method.

In advance, water or catalyst water and, if necessary, other additives are applied and mixed on the beads as the base material,
Water-foaming polyisocyanate resin is applied and mixed.

It is possible to obtain a buffer material by filling a predetermined amount of beads sprinkled with a binder into a mold having a desired shape as uniformly as possible and sealing the upper mold. Mold temperature can be sufficiently molded even at room temperature, but 40 ℃ to accelerate curing.
Above, it is desirable to heat to 50 to 70 ° C. Although the demolding time depends on the heating temperature, it is usually 5 to 10 minutes.

The buffer material produced by using the water-foamable polyisocyanate resin of the present invention as a binder has various properties such as resin type, substrate type and mixing ratio, resin coating amount, and filling amount in a mold. Since the hardness, elasticity, feel, etc. of the cushioning material can be variously changed by adjustment and the like, it can be applied to an extremely wide range of fields. For example, it can be applied to tatami floors, mats under carpets, packing agents, lining materials (partitions, ceiling materials, doors, etc.).

[0045]

EFFECT OF THE INVENTION The buffer material of the present invention can be molded in a low temperature range in a short time, does not use a solvent having a low boiling point, has a small defect rate because uniformity of molded products can be easily obtained, and the like. Although many advantages are recognized, the characteristic advantages of the molded article itself are that it has excellent buffer compression characteristics, sound absorption / sound insulation characteristics, water resistance, heat insulation characteristics, and the like.
What is more important to note is that when it is landfilled as waste, it has a biodegradability, and therefore exhibits a sufficient volume reduction effect in a short time.

[0046]

[Examples] Production examples of water-foamable polyisocyanate resins used in the following examples are shown, and examples are also shown.

The polyoxyalkylene addition higher aliphatic amine derivative used in the examples is abbreviated as amine derivative polyol. Unless otherwise specified, parts and% in the following examples refer to “parts by weight” and “% by weight”, respectively.

<Production of water-foamable polyisocyanate resin>

[0049]

Reference Example 1 A water-foamable polyisocyanate resin (I) was prepared in the following manner.

Polymethylene polyphenyl polyisocyanate (manufactured by Nippon Polyurethane Industry, "Coronate 103"
9 "NCO content 32.2%) and 35 parts of toxypolyethylene glycol having an average molecular weight of 700 were reacted at 80 ° C for 3 hours to obtain a self-emulsifying polyisocyanate resin.

After the resin was cooled to 40 ° C. or lower, sardine oil amine E15 (alkyl distribution: carbon number 20 to 22) was obtained as an amine derivative polyol (corresponding to general formula (1)).
Is about 90%, the number of moles of ethylene oxide added is 15, and 242 parts of a hydroxyl value of 138) is added while confirming the temperature rise, and finally held at 80 ° C. for 3 hours to obtain a water-foamable polyisocyanate resin. It was The NCO content of this resin was 21.8%.

[0052]

[Reference Example 2] A water-foamable polyisocyanate resin (II) was prepared in the following manner.

Liquid diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry, "Millionate MT
L ", NCO content 29.0%) 1000 parts, and 312 parts of polyether polyol having an average molecular weight of 8400 obtained by randomly adding ethylene oxide to pentaerythritol at an addition molar ratio of 80/20 are reacted at 80 ° C for 3 hours. A hydrophilic polyisocyanate resin was obtained.

After cooling 1000 parts of this resin to 40 ° C. or lower, an amine derivative polyol (general formula (2)
Beef tallow diamine E13 (Alkyl distribution: 18% carbon has about 24%, 18 carbons with one unsaturated bond)
Was 37%, the number of carbon atoms was 30%, the number of moles of ethylene oxide added was 3, and the hydroxyl value was 390 (62 parts) was reacted in the same manner as in Reference Example 1 to obtain a water-foamable polyisocyanate resin. The NCO content of this resin was 19%.

[0055]

Reference Example 3 A water-foamable polyisocyanate resin (III) was prepared in the following manner.

1000 parts of "Millionate MTL" and 1049 parts of polyether polyol having an average molecular weight of 3000 in which ethylene oxide and propylene oxide are randomly added to glycerin at an addition molar ratio of 90/10 are reacted at 80 ° C. for 3 hours to make them hydrophilic. A polyisocyanate resin was obtained.

After cooling 1000 parts of this resin to 40 ° C. or lower, an amine derivative polyol (general formula (3)
Beef tallow amide E50 (alkyl distribution:
About 63% of carbon number, 16% of carbon number, 30%, the number of moles of ethylene oxide added is 50, and the hydroxyl value is 48) 134 parts are reacted in the same manner as in Example 1 to obtain a water-foamable polyisocyanate resin. It was The NCO content of this resin is 10
%Met. In order to reduce the viscosity of this resin, resin 750
250 parts of a mixture of ethylene carbonate and propylene carbonate 1: 1 was added to parts to obtain the final resin.

[0058]

[Reference Example 4] A water-foamable polyisocyanate resin (IV) was prepared in the following manner.

A self-emulsifying type polymethylene polyphenyl polyisocyanate (manufactured by Nippon Polyurethane Industry, "Coronate 3053", NCO content 29.5%) was added to 1000 parts of beef tallow amide amine E15 (corresponding to general formula (4)) as an amine derivative polyol (corresponding to general formula (4)). Alkyl distribution: 3 carbons 18
Example 7: 7%, carbon number 16 = 30%, ethylene oxide addition mole number = 15, hydroxyl value 190) = 174.5 parts
A reaction was carried out in the same manner as in, to obtain a water-foamable polyisocyanate resin. The NCO content of this resin was 23%.

[0060]

Examples 1 to 4 and

[Comparative Examples 1 to 4] Water-foamable polyisocyanate resins (I) to (IV), and the same organic polyisocyanate compound as a base, the same as (I) to (IV) were used, and finally A resin that is not modified with an amine derivative polyol is used as a comparative example, and resin (V), (VI), (VI
I) and (VIII). Resin (I) corresponds to resin (V), and (II), (III), and (IV) are (V
Corresponds to I), (VII), and (VIII). A buffer material was prepared using these eight kinds of resins, and the buffer property and biodegradability were measured.

However, the expanded polystyrene beads are those which are expanded about 50 times by a known method and have a diameter of 3-4.
mm mixture, apparent density 0.017 g /
It was cm ³ . Porous cellulose beads are disclosed in
No. 170501 manufactured in Example 1 and produced by foaming, regenerating and drying granularly from viscose, which is composed of a mixture having a diameter of 3.5 to 4.5 mm and an apparent density of 0. It was 02 ± 0.05 g / cm ³ .

As the buffer material, after measuring a predetermined amount of beads,
Water is applied evenly to the surface of the beads, and then the resin is applied in the same manner as water. 2 this mixture
A mold having a size of 0 cm × 20 cm × 2.5 cm was filled as uniformly as possible, and then heated and cured in an oven at 60 ° C. for 5 minutes.

In Table 1, expanded polystyrene beads (mixture having a diameter of 2.5 to 3.5 mm) are PS-B and porous cellulose beads (mixture having a diameter of 3.5 to 4.5 mm) are C-.
It is abbreviated as B. Thickness reduction (%) is based on JIS Z 1
It was calculated from the thickness of the sample piece after 50% compression in accordance with 536 “Cushioning material for polystyrene foam packaging”.

Water-foamable polyisocyanate resins (I), (II), (III), (IV), (V) and (V
Each of I), (VII) and (VIII) is used. 1 part of expanded polystyrene beads and 6 parts of porous cellulose beads are weighed and mixed with 2 parts of water by spraying, and then any of water-expandable polyisocyanate resins (I) to (VIII) 6
After adding the parts, a desired mold is uniformly filled while uniformly mixing, and heated and cured in an oven at 60 ° C. for 5 minutes.

After drying at 105 ° C., the apparent density and buffer characteristics were measured. The results are shown in Table 1.

Each of the water-foamable polyisocyanate resins (I) to (IV) is used as an adhesive. After spraying and mixing water on the porous cellulose beads, one of the water-expandable polyisocyanate resins (I) to (IV) is applied to the expanded polystyrene beads, and the desired mixture is obtained by uniformly mixing with the porous cellulose beads. After filling the mold uniformly,
Heat cure for 5 minutes in an oven at 60 ° C. 105
After drying at ℃, the apparent density and the buffer property were measured. The results are shown in Table 2. When the buffer was observed to be burned in a small household incinerator, black smoke was less likely to be generated during the burning, but rather the burning state when burning paper or wood was shown. When observed outdoors, it was found that disintegration was easily caused by repeated water injection and drying. The buffer is designated ASTM-G
According to the mold resistance test of -21-70, remarkable growth of bacteria was observed in 3 weeks, and cracking / deformation was observed in 6 weeks and collapse was observed.

The mechanical strength of the foamed cushioning body in Table 1 is expressed by static compressive stress and settability (thickness reduction), PS-B / C-
B = 1/9 (W / W).

[0068]

[Table 1]

With respect to the resins (V) to (VIII), poor adhesion was caused, and molding was possible by prolonging the pressing time, but the density exceeded 500 Kg / m ^3, and therefore it was unsuitable.

The mechanical strength of the foamed cushioning body in Table 2 is shown by static compressive stress and settability (thickness reduction).

The conventional expanded polystyrene in Table 2 is
It is a product of Daiwa Shiki Co., Ltd. with a foaming ratio of 50 times.

[0072]

[Table 2]

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical indication location C08L 25/04 LDQ 9166-4J 75/04 NGG 8620-4J F16F 7/00 B 9240-3J (72) Inventor Kensuke Tani 440, Akiba-cho, Totsuka-ku, Yokohama-shi, Kanagawa Nihon Polyurethane Industry Co., Ltd.

Claims (3)

[Claims] 1. A biodegradable cushioning material comprising primary expanded polystyrene beads and porous cellulose beads bound by a water-expandable polyisocyanate resin. 2. When producing a biodegradable buffer material using expanded beads and a water-expandable polyisocyanate resin, (a) primary expanded polystyrene beads and porous cellulose beads are used together as expanded beads, and B) Water-foamable polyisocyanate resin has 2 in the molecule
An organic polyisocyanate compound having one or more isocyanate groups and / or an isocyanate group-terminated prepolymer thereof and one obtained by reacting one or more polyoxyalkylene-added higher aliphatic amine derivatives are used. To produce a biodegradable buffer material. 3. The polyoxyalkylene-added higher aliphatic amine derivative is at least one kind of dialkoxylate monoalkylamine, trialkoxylate monoalkyldiamine, dialkoxylate monoalkylamide and trialkoxylate monoalkylamidoamine. The method according to claim 2.