JP3090592B2 - Sugar ester polyol, method for producing the same, and biodegradable polyurethane using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sugar ester polyol produced from saccharides and a method for producing the same.
More specifically, the present invention relates to a sugar ester polyol which is easily decomposed by microorganisms and the like in a natural environment after use and is used as a raw material of polyurethane, a method for producing the same, and a biodegradable polyurethane prepared using the same.

[0002]

2. Description of the Related Art In recent years, attempts have been made widely to impart natural degradability to synthetic polymers such as plastics. Polyurethanes prepared by reacting a polyol component with an isocyanate component are also required to be biodegradable. Various attempts have been made to provide

For example, in Japanese Patent Publication No. 58-56605,
A hydrophilic urethane foam obtained by adding a powdery organic filler of a microbe-promoting microorganism to a hydrophilic urethane foam, and JP-A-63-284232 discloses a method in which a vegetable fine fiber or a vegetable powder contains an ester group. Disclosed are naturally decomposable sheets and molded articles bonded to a urethane resin obtained by a reaction between a polyol and an organic polyisocyanate.

In each of the above inventions, the presence of additives such as natural organic substances and vegetable fibers is essential, and it is said that the additives are not basically decomposable but decomposable.

By the way, recently, unlike the above method, a method has been developed in which a polyurethane itself is made biodegradable by adding molasses to a polyol component (Japanese Patent Application No. 3-33302). Polyurethane obtained by this technique does not use vegetable microfibers, etc., so it has satisfactory biodegradability while having the same appearance as normal one, but because the molasses used is a natural product Depending on the conditions, it was difficult to control polyurethane foaming and the like.

[0006]

Although the use of molasses described above has made it possible to impart almost satisfactory biodegradability to polyurethane itself, it has been required to further solve the above-mentioned processing problems. Accordingly, an object of the present invention is to provide a technique for producing a biodegradable polyurethane which has solved this problem.

[0007]

Means for Solving the Problems The present inventors have studied the possibility of using a saccharide as a polyol for producing polyurethane, and as a result, modified the hydroxyl group of the saccharide with an ester group to obtain a biodegradable saccharide. The present inventors have found that a polyol having excellent performance can be obtained as a raw material for polyurethane, and completed the present invention.

That is, the present invention provides the following formula (I)

Embedded image (Wherein, R represents a sugar skeleton, A represents an alkylene group, n represents the total number of hydroxyl groups in the sugar, m represents the number of hydroxyl groups to be esterified in the sugar, and nm is not esterified. Is the number of hydroxyl groups in the remaining sugar, and indicates a number in the range of 0 to n-1, and the product of l and m indicates the number of cyclic lactone added to the hydroxyl group of the sugar. To provide.

The sugar ester polyol of the present invention is produced by adding a cyclic lactone represented by the formula (III) to a saccharide represented by the formula (II) according to the following formula to form an ester.

Embedded image (Wherein, R, A, m, n and l have the meaning described above)

Examples of the saccharide (II) include monosaccharides such as glucose, fructose, mannose, arabinose, xylose and galactose, disaccharides such as sucrose, cellobiose and maltose, oligosaccharides such as cellotriose, cellulose, starch and glycogen. , Caronine, laminaran, dextran, inulin, levan,
Mannan, xylan, pectic acid, alginic acid, chitin, guaran, heparin, chondroitin sulfate, hyaluronic acid, meskit gum, gatch gum, gum arabic,
Polysaccharides such as plant mucilage and bacterial polysaccharides are used.

Alternatively, molasses, which is a mixture thereof, may be used. Molasses is obtained from sugarcane, sugar beet, etc., and may be purified molasses, molasses, or molasses obtained after sugar production, but molasses is advantageous in terms of economy. is there.

On the other hand, examples of the cyclic lactone (III) include, for example, methyl ε-caprolactone, ε-caprolactone, β-propiolactone, β-butyrolactone, δ-
Cyclic lactones such as valerolactone and compounds having an aliphatic or aromatic substituent on them can be preferably used. These cyclic lactones are 2
More than one species can be used in combination.

The above saccharide (II) and cyclic lactone (III)
Reaction with the number of hydroxyl groups to be esterified in the saccharide is m
In general, about 1 to 100 moles of the cyclic lactone (III) per mole of the hydroxyl group of the saccharide (II)
What is necessary is to perform using.

The reaction is carried out in the presence or absence of a solvent, generally, for example, a catalyst such as a metal alcoholate such as tin, lead, manganese or aluminum, a metal carboxylate, an alkyl metal or a chelate metal, more specifically, For example, di-n-butyltin dilaurate, tin di (2-ethylhexanoate),
Using a catalyst such as titanium tetraisopropoxide or aluminum triisopropoxide, the reaction may be performed at a temperature of room temperature to about 180 ° C. for about 1 to 24 hours.

In the above reaction, a saccharide (II) and a polyhydric alcohol may be used in combination to react with the cyclic lactone (III).

The sugar ester polyol of the present invention thus obtained can be used as a raw material for producing polyurethane, similarly to a usual polyol component. For example,
If necessary, the sugar ester polyol of the present invention is mixed with a conventionally known polyol component and reacted with a known isocyanate component to produce a biodegradable polyurethane.

For example, a polyisocyanate component is added to and mixed with the sugar ester polyol obtained as described above or a mixture of the sugar ester polyol and a known polyol component.
The reaction can be performed at a temperature of 50 ° C, preferably 20 to 120 ° C, at normal pressure or under pressure.

The proportion of the polyisocyanate component used in the production of the polyurethane is 25 to 75%, preferably about 35 to 65%.

As the isocyanate component to be used,
There is no particular limitation, and examples thereof include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates, and modified products thereof.

Among them, the aliphatic polyisocyanate includes, for example, hexamethylene diisocyanate, and the alicyclic polyisocyanate includes, for example, isophorone diisocyanate.

Examples of the aromatic polyisocyanate include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate (MDI), polymeric diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatephenyl) thiophosphate. .

Further, examples of the modified polyisocyanate include urethane prepolymer, hexamethylene diisocyanate buret, hexamethylene diisocyanate trimer, isophorone diisocyanate trimer and the like.

In the production of polyurethane, it is preferable to add a catalyst for the urethane reaction to the sugar ester polyol. As such a catalyst, a conventionally known catalyst such as a tin-based catalyst or an amine-based catalyst may be used. it can.

In the production of polyurethane according to the present invention, a mixture obtained by adding and mixing a polyisocyanate to a sugar ester polyol is used as a molding material, molded into a required shape, and then subjected to a urethane-forming reaction to obtain a polyurethane having a required shape. It can be a composite molded article.
Further, by adding an appropriate amount of water as a foaming agent to the sugar ester polyol, a foam molded article can be obtained. The shape of the molded product can be various shapes such as a sheet shape, a plate shape, a column shape, and a container shape.

[0025]

The reason that the polyurethane prepared by using the sugar ester polyol of the present invention has high strength and exhibits biodegradability as will be described in Examples below is due to the action of the sugar component in the sugar ester polyol. . That is, since sugar acts as a hard segment in the polyurethane, the strength can be increased. And, in the biodegradable polyurethane of the present invention, the sugar component incorporated therein is preferentially subjected to the action of the microorganism, and is rapidly decomposed.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention.

EXAMPLE 1 5 g of glucose was weighed and dissolved in 5 g of ethylene glycol. 5.84 g of the resulting solution
0.02 g of di-n-butyltin dilaurate was added to
Then, a mixture of 80 g of ε-caprolactone and 0.05 g of di-n-butyltin dilaurate was added dropwise at 150 ° C. over 1 hour and 30 minutes. After the dropwise addition, the reaction was further continued at 150 ° C. for 22 hours to prepare a glucose-ethylene glycol-based sugar ester polyol.

The resulting sugar ester polyol had a number average molecular weight of 2,018, a weight average molecular weight of 4,965, a softening point of 35.6 ° C., and a hydroxyl value of 60.84 mg KOH / g.

Further, the following absorption was confirmed from the infrared absorption spectrum. Ester: 1726 cm ^-1 , 1244 cm ^-1 Ether: 1192 cm ^-1 Alcohol: 3437 cm ^-1 , 1047 cm ^-1 Methylene: 2946 cm ^-1 , 2866 cm ^-1 , 733
cm ^-1

Example 2 In Example 1, 5.84 g of a solution in which fructose was dissolved in ethylene glycol in an equal amount instead of glucose.
Was used to prepare a fructose-ethylene glycol-based sugar ester polyol in the same manner as in Example 1.

The obtained sugar ester polyol has a number average molecular weight of 3,061, a weight average molecular weight of 5,413, a softening point of 34.70 ° C., and a hydroxyl value of 71.97 mg KOH / g.
Met.

Further, the following absorption was confirmed from the infrared absorption spectrum. Ester: 1728 cm ^-1 , 1244 cm ^-1 Ether: 1190 cm ^-1 Alcohol: 3444 cm ^-1 , 1048 cm ^-1 Methylene: 2946 cm ^-1 , 2868 cm ^-1 , 732
cm ^-1

Example 3 A solution obtained by dissolving an equal amount of sucrose in ethylene glycol in place of glucose in Example 1 6.30 g
Was used to prepare a sucrose-ethylene glycol-based sugar ester polyol in the same manner as in Example 1.

The obtained sugar ester polyol had a number average molecular weight of 1,762, a weight average molecular weight of 3,935, a softening point of 33.7 ° C., and a hydroxyl value of 73.97 mg KOH / g.

Further, the following absorption was confirmed from the infrared absorption spectrum. Ester: 1726 cm ^-1 , 1244 cm ^-1 Ether: 1192 cm ^-1 Alcohol: 3437 cm ^-1 , 1047 cm ^-1 Methylene: 2946 cm ^-1 , 2866 cm ^-1 , 733
cm ^-1

Example 4 80 g of molasses was weighed out in 20 g of ethylene glycol, and mixed and stirred with a mixing stirrer for about 2 hours. Then
The mixture was centrifuged at 8,000 rpm for 20 minutes using a centrifuge to remove solid residue. 14.74 g of the obtained mixture (moisture ratio: 23%) was subjected to water removal, and then to a water content of 0.47 g.
02 g of di-n-butyltin dilaurate are added, and a mixture of 80 g of ε-caprolactone and 0.05 g of di-n-butyltin dilaurate is added at 150 ° C. for 1 hour 3 hours.
It was added dropwise over 0 minutes. After the addition, the temperature was further increased to 150 ° C for 22 minutes.
The reaction was continued for an hour to prepare a molasses-ethylene glycol-based sugar ester polyol.

The obtained sugar ester polyol had a number average molecular weight of 1,845, a weight average molecular weight of 4,503, a softening point of 34.1 ° C., and a hydroxyl value of 77.88 mg KOH / g.

The following absorption was confirmed from the infrared absorption spectrum. Ester: 1726 cm ^-1 , 1246 cm ^-1 Ether: 1194 cm ^-1 Alcohol: 3437 cm ^-1 , 1047 cm ^-1 Methylene: 2944 cm ^-1 , 2866 cm ^-1 , 733
cm ^-1

Example 5 A mixture of 80 g of ε-caprolactone and 0.07 g of di-n-butyltin dilaurate was added dropwise to 7.48 g of sucrose at 150 ° C. for 1 hour and 30 minutes. After dripping,
Further, the reaction was continued at 150 ° C. for 22 hours.
A sugar ester polyol was prepared.

The following absorption was confirmed from the infrared absorption spectrum of the obtained sugar ester polyol.

Ester: 1726 cm ^-1 , 1244 cm ^-1 Ether: 1192 cm ^-1 Alcohol: 3437 cm ^-1 , 1047 cm ^-1 Methylene: 2946 cm ^-1 , 2866 cm ^-1 , 733
cm ^-1

Example 6 A solution obtained by dissolving 1 g of cellulose in 50 ml of hexamethylphosphonamide in which 4 g of lithium chloride was dissolved and adding a small amount of dibutyl tin dilaurate to the solution containing a small amount of dibutyl tin dilaurate was added. ε-caprolactone
5 g was added dropwise at 170 ° C., and the mixture was reacted for 2 hours. 50 ml of water was added to the obtained solution, which was placed in a cellophane tube for desalting, and then water in the tube content was distilled off under reduced pressure. In the infrared absorption spectrum of the obtained compound, absorption at 1730 cm ^{-1 due} to an ester bond was observed.

Example 7 30 g of the sugar ester polyol obtained in Example 4 was heated and melted, and then deaerated in a vacuum. 5.64 there
g of crude diphenylmethane diisocyanate (M
DI), and the mixture was slowly mixed and stirred, and then degassed.

The obtained mixture was heated at 110 ° C. and 200 kgf
/ Cm ² for 2 hours to prepare a polyurethane sheet. The glass transition temperature of this polyurethane sheet is-
The temperature was 49.6 ° C and the thermal decomposition temperature was 337.4 ° C.

Example 8 8.0 g of the sugar ester polyol obtained in Example 3 was melted, weighed into 12.0 g of commercially available polycaprolactone (average molecular weight: 550), mixed slowly and stirred, and then stirred under vacuum. Degassed. To this, 7.33 g of MDI was added, and the mixture was slowly mixed and stirred, followed by degassing.

The obtained mixture was heated at 110 ° C. and 200 kgf
/ Cm ² for 2 hours to prepare a polyurethane sheet. The glass transition temperature of this polyurethane sheet is-
The temperature was 19.1 ° C and the thermal decomposition temperature was 333.7 ° C.

Example 9 50 g of the sugar ester polyol obtained in Example 4 was used in an amount of 50 g.
In a commercially available polycaprolactone (average molecular weight: 2,000), into which 3.0 g of water, 2.7 g of a foam stabilizer (NUC Silicone L-520; manufactured by Nippon Unicar Co., Ltd.), and a tin-based catalyst (dilaurate di- 0.6 g of an n-butyltin) and 0.6 g of an amine catalyst (diazabicyclooctane) are added and stirred well. 73.4 g of MDI is added thereto and stirred, and when the foaming starts, the stirring is stopped. After the foaming had sufficiently proceeded, the product was further left overnight to prepare a polyurethane foam.

[0048]

The polyurethane prepared by using the sugar ester polyol of the present invention has excellent biodegradability and decomposes rapidly in nature. Therefore, the biodegradable polyurethane of the present invention returns to nature after it is no longer needed, and can be widely used not only as agricultural and horticultural materials but also for household and industrial uses. that's all

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruichi Teruya 5-1 Kashizaki, Gushikawa-shi, Okinawa Inside the Tropical Techno Center Co., Ltd. (72) Inventor Takeshi Ken Kobashigawa 5-1 Jushizaki, Gushikawa-shi, Okinawa Tropical Techno Inside the Center (72) Inventor Yui Tokashiki 5-1, Kashizaki, Gushikawa-shi, Okinawa Tropical Techno Center Co., Ltd. (56) References JP-A-8-73575 (JP, A) (58) Fields surveyed (Int. Cl ^7, DB name) C07H 13/04 C08G 18/28 -. 18/32 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A compound represented by the following formula (I): (Wherein R is a monosaccharide, disaccharide, oligosaccharide or polysaccharide)
(However, excluding molasses) , A represents an alkylene group, n represents the total number of hydroxyl groups in the sugar, m represents the number of hydroxyl groups to be esterified in the sugar, and nm represents esterification. Is the number of hydroxyl groups in the remaining sugar, and represents a number in the range of 0 to n-1, and the product of l and m represents the number of cyclic lactone added to the hydroxyl group of the sugar. Polyol. 2. The cyclic lactone is methyl ε-caprolactone, ε-caprolactone, β-propiolactone,
The sugar ester polyol according to claim 1, which is one or more of β-butyrolactone, δ-valerolactone, and a compound having an aliphatic or aromatic substituent on these. 3. The following formula (II): (Wherein, R represents the sugar skeleton of a monosaccharide, disaccharide, oligosaccharide or polysaccharide (excluding molasses), and n represents the total number of hydroxyl groups in the sugar). (III) Wherein A represents an alkylene group, wherein a cyclic lactone represented by the following formula (I) is added: (Wherein, R, A and n have the above-mentioned meanings, m represents the number of hydroxyl groups to be esterified in the sugar, and nm is the number of hydroxyl groups in the remaining sugar that is not esterified, 0-n-
And the product of 1 and m indicates the number of cyclic lactones added to the hydroxyl groups of the sugar). 4. A biodegradable polyurethane obtained by reacting the sugar ester polyol according to claim 1 with an isocyanate. 5. The cyclic lactone is methyl ε-caprolactone, ε-caprolactone, β-propiolactone,
The biodegradable polyurethane according to claim 4, which is one or more kinds of β-butyrolactone, δ-valerolactone, or a compound having an aliphatic or aromatic substituent on these.