JP2883271B2 - Polyol composition for biodegradable flexible polyurethane and method for producing polyurethane foam 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 polyol composition for polyurethane as a raw material for producing polyurethane, and more particularly, to a biodegradable raw material for a flexible polyurethane foam which is easily decomposed by microorganisms in a natural environment. The present invention relates to a polyol composition for a flexible polyurethane, a biodegradable flexible polyurethane foam using the same, and a method for producing the same.

[0002]

2. Description of the Related Art Plastics are easy to process, cost,
Currently, it is widely used because of its lightness and ease of use. However, unlike naturally occurring polymer compounds, plastics are hardly decomposed by microorganisms in nature and cause environmental pollution, which is a major social problem.

[0003] That is, plastic waste is hardly decomposed by the action of soil bacteria and the like.
It remained long where it was dumped and was very unsightly. Also, when dumped on the sea, it drifts on the sea surface without undergoing biodegradation, which causes marine pollution, and also causes problems in the ecological environment, such as sea turtles swallowing food jellyfish mistakenly and leading to death. I was

[0004] Among plastics, polyurethane is prepared by reacting a polyol component and an isocyanate component. However, this plastic has almost no biodegradability like other plastics, and foamed polyurethane has a large capacity, so that it is environmentally friendly. It was a major source of pollution.

Heretofore, several attempts have been made to impart biodegradability to this polyurethane. For example, Japanese Patent Publication No. 58-56605 discloses a hydrophilic urethane foam obtained by adding a powdery organic filler of microorganisms to a hydrophilic urethane foam, and Japanese Patent Application Laid-Open No. 63-284232 discloses a vegetable fine fiber or Disclosed are sheets and molded articles that decompose in the natural world by combining vegetable powder with a urethane resin obtained by reacting an ester group-containing polyol with an organic polyisocyanate.

[0006] In any of these inventions, the presence of additives such as natural organic substances and plant fibers is essential, and it is considered that these greatly contribute to biodegradability. Is considered to be due not to the decomposability of the polyurethane itself but to the decomposability of the additive.

[0007]

However, there are various types of polyurethanes, and in some cases, the above-mentioned organic substances and plant fibers cannot be blended. There was a need for the development of technologies to make them more reliable.

[0008]

Means for Solving the Problems As a result of repeated studies to obtain a biodegradable polyurethane, the present inventors have found that by adding molasses to the polyol component which is a raw material of the polyurethane, the biodegradable polyurethane is first obtained. Can be produced (Japanese Patent Application No. 3-33302). However, in this technique, since molasses acts as a hard segment in the polyurethane, only a hard polyurethane can be obtained, and it is difficult to say that the polyurethane is sufficiently satisfactory.

Therefore, as a result of further study for solving the above drawback and obtaining a flexible polyurethane, it was found that, in addition to a polyol as a component for dissolving molasses and a polyol component acting as a plasticizer, a polyol for a flexible polyurethane can be obtained. The present inventors have found that they can be used as components and completed the present invention.

That is, the present invention provides the following three components (a):
(B) and (c) (a) molasses, (b) polyethylene glycol having an average molecular weight of 200 to 400
Coal or ethylene glycol or glycerin
La polyol (c) an average molecular weight selected is 600 to 3000, is to provide a polyethylene glycol, polypropylene glycol or Poriesu <br/> biodegradable flexible polyurethane Polyol composition comprising a polyol selected from ether polyol .

Further, the present invention provides a method for producing a biodegradable flexible polyurethane foam, which comprises reacting the above polyol composition for a biodegradable flexible polyurethane with an isocyanate compound, and a polyurethane foam obtained by this method. To provide.

The polyol composition for a biodegradable flexible polyurethane of the present invention (hereinafter referred to as "soft molasses polyol")
Among the components constituting the above, the molasses of the component (a) is obtained from sugarcane, sugar beet, or the like, and may be purified molasses or molasses, or may be molasses obtained after sugar production. However, molasses is advantageous in terms of economy.

Further, the average component (b) of the present invention is used.
Polyethylene glycol with a molecular weight of 200 to 400 or
PO selected from ethylene glycol or glycerin
Riol (hereinafter, referred to as “low molecular polyol”) has an action of dissolving molasses. This low molecular polyol is limited to those described above, and other polyols (eg, PEG, polypropylene glycol, and polyester polyol having a higher molecular weight) Polyols, etc.)
It is difficult to sufficiently dissolve molasses.

Further, PEG, polypropylene glycol (PPG) and polyester polyol (PE) having an average molecular weight of 600 to 3000, which is the component (c) of the present invention, are used.
The polyol selected from S) (hereinafter, referred to as “polymer polyol”) imparts flexibility to the hardened polyurethane by the incorporation of molasses as the component (a), and acts as a so-called plasticizer that replaces the softened polyurethane. Things.

Of the components (c), PEG can soften polyurethane from those having an average molecular weight of 600 or more, and is solid (room temperature) from a molecular weight of 1,000 or more, but molasses polyol having an average molecular weight of about 3000 Has a melting point below the temperature at which it does not denature and does not particularly thicken. In the case of PPG and the case of PES, the average molecular weight is 1000 to 40 for the same reason as PEG.
It is preferable to use those having a range of 00 and an average molecular weight of 1,000 to 3,000. Among them, examples of PES include polycaprolactone.

The soft molasses polyol of the present invention is prepared by first adding molasses as component (a) to low molecular polyol as component (b), mixing and dissolving the components, and then adding (c)
It is carried out by adding a polymer polyol as a component and subjecting the obtained mixed solution to centrifugation as needed to remove insolubles. This centrifugation is performed at 10 to 60 ° C.
It may be carried out at a rotation speed of about 2,000 to 8,000 rpm for about 10 to 60 minutes under such a temperature condition. Also,
The component (c) can be added to the molasses polyol composed of the components (a) and (b) together with a urethane reaction catalyst, water for foaming, and the like.

The amount of each component in the soft molasses polyol of the present invention is such that component (a) is 10 to 25% by weight.
(Hereinafter simply referred to as “%”), and component (b) is 25 to 40.
%, The component (c) is about 35 to 65%,
(A) component is 12 to 20%, and (b) component is 28 to 40.
%, Component (c) is preferably in the range of 40 to 60%.

Although the obtained molasses polyol can be used as a polyol component of polyurethane as it is, molasses generally contains about 17 to 25% of water. Preferably, water is removed from the soft molasses polyol to reduce the water content to about 0.1 to 3%.

That is, since the isocyanate component that reacts with the polyol component has high reactivity with water, if the water content in the polyol component is large, the foaming reaction between the isocyanate component and water proceeds preferentially, and The gelation reaction does not proceed sufficiently, resulting in non-uniform cells, insufficient strength of the cell membrane, etc., resulting in a decrease in the strength of the entire polyurethane, and because the reaction is an exothermic reaction, the inside of the polyurethane is scorched. As a result, polyurethane having excellent physical properties cannot be obtained.

As a method for removing water from the soft molasses polyol, a vacuum concentration method, a freeze-drying method and the like can be mentioned. Among them, under a reduced pressure of about 40 to 0.01 Torr,
A vacuum concentration method of removing water at a temperature of about 30 to 60 ° C is preferred.

The soft molasses polyol of the present invention obtained as described above can be used as a raw material for the production of a flexible polyurethane in the same manner as a usual polyol component.
By reacting with a conventionally known isocyanate component according to a conventional method, a biodegradable flexible polyurethane foam can be produced.

For example, the soft molasses polyol obtained as described above is mixed with a polyisocyanate component and, if necessary, a small amount of water, and mixed at a temperature of 10 to 150 ° C., preferably 20 to 120 ° C., normal pressure or pressure. By reacting under pressure, a flexible polyurethane foam having biodegradability is produced.

The proportion of the polyisocyanate component used in the production of the polyurethane is 25 to 75%, preferably 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, examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (H
DI), and examples of the alicyclic polyisocyanate include isophorone diisocyanate.

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

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

In producing a polyurethane foam, it is preferable to add a catalyst for a urethane-forming reaction to the soft molasses polyol. As such a catalyst, a conventionally known catalyst such as a tin-based or amine-based catalyst may be used. Can be.

In the case of producing a biodegradable flexible polyurethane foam according to the present invention, a mixture obtained by adding and mixing a soft molasses polyol, polyisocyanate and a small amount of water as required is used as a molding material and molded into a required shape. Thereafter, a polyurethane composite foam molded article having a required shape can be obtained by performing a urethanization reaction. The shape of the molded product can be various shapes such as a sheet, a plate, a column, and a container.

[0030]

The polyurethane foam prepared by using the molasses polyol of the present invention becomes a flexible polyurethane because the rigidity of molasses acting as a hard segment in the polyurethane is reduced by the action of the high molecular polyol. And
Once the polyurethane foam is discarded, the molasses component incorporated therein is preferentially subjected to the action of microorganisms and is rapidly decomposed.

[0031]

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 (1) Preparation of molasses polyol: molasses (moisture content 19.6)
%) 20 g to 40 g of polyethylene glycol 200
(PEG 200, average molecular weight 200), and mixed and stirred with a mixing stirrer for about 1 hour. Then, the mixture was centrifuged at 8,000 rpm for 20 minutes by a centrifuge to remove solid residue. The supernatant liquid after centrifugation was concentrated under reduced pressure at 1 Torr for 4 hours using a centrifugal evaporator. Furthermore, 6 g of polyethylene 600 (PEG 600, average molecular weight 600) was added to 40 g of the obtained solution.
0 g was added to obtain 100 g of soft molasses polyol.

(2) Preparation of polyurethane foam: 100 g of the soft molasses polyol obtained in the above (1) was added to water 1.0.
g, silicone-based surfactant (NUC silicone L-
520; manufactured by Nippon Unicar Co., Ltd.) 1.6 g, 0.8 g of a silicone-based foam breaker, 2.8 g of a tin-based catalyst (di-n-butyltin dilaurate), and an amine-based catalyst (N, N, N ', N ",
2.8 g of N "-pentamethyldiethylenetriamine) is added and stirred well. 49 g of crude MDI is added 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. The polyurethane foam thus obtained was a flexible foam in which cells were connected, and its density was 0.14 g / cm ³ .

Example 2 (1) Preparation of molasses polyol: molasses (moisture content 19.6)
%) Of 20 g was weighed into 40 g of PEG200, and mixed and stirred with a mixing stirrer for about 1 hour. Next, the mixture was centrifuged at 8,000 rpm for 20 minutes using a centrifuge to remove solid residue. The supernatant liquid after centrifugation was concentrated under reduced pressure at 1 Torr for 4 hours using a centrifugal evaporator. Further, 50 g of PEG 600 was added to 50 g of the obtained solution to obtain 100 g of soft molasses polyol.

(2) Preparation of polyurethane foam: 50 g of the soft molasses polyol obtained in (1) above, 25 g of a silicone-based surfactant (NUC Silicone L-520; manufactured by Nippon Unicar Co., Ltd.), and a tin-based catalyst (dilauric acid) Di-n
-Butyltin) 0.15 g and amine catalyst 1.15 g
(N, N, N ', N ", N" -pentamethyldiethylenetriamine) and stir well. Crude MD there
71.5 g of an equal mixture of I and HDI is added 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.

Example 3 (1) Preparation of molasses polyol: molasses (moisture content 19.6)
%) Of 20 g was weighed into 40 g of PEG200, and mixed and stirred with a mixing stirrer for about 1 hour. Next, the mixture was centrifuged at 8,000 rpm for 20 minutes using a centrifuge to remove solid residue. The supernatant liquid after centrifugation was concentrated under reduced pressure at 1 Torr for 4 hours using a centrifugal evaporator. Furthermore, polypropylene glycol 3000 (PPG3000, average molecular weight 300) was added to 50 g of the obtained solution.
0) was added to obtain 100 g of soft molasses polyol.

(2) Preparation of polyurethane foam: 50 g of molasses polyol obtained in (1) above, 10 g of water, and a silicone-based surfactant (NUC silicone L-520;
2.5 g, manufactured by Nippon Unicar Co., Ltd., silicone-based foam breaker
2.5 g, tin catalyst (di-n-butyltin dilaurate)
0.4 g and 0.4 g of an amine catalyst (N, N, N ', N ", N" -pentamethyldiethylenetriamine) are added and stirred well. 227 g of crude 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. The polyurethane foam thus obtained was a flexible foam in which cells were connected, and the density was 0.018 g / cm ³ .

[0038]

The polyurethane foam prepared by using the soft molasses polyol of the present invention has the same physical properties as the conventional flexible polyurethane foam while incorporating molasses. In addition, it was excellent in biodegradability and decomposed rapidly in the natural world. Therefore, the polyurethane foam prepared using the soft molasses polyol of the present invention can be used in the same manner as a conventional flexible polyurethane foam, but returns to nature after it is no longer needed. It can be widely used for home use, industrial use, and the like. that's all

Continued on the front page (72) Inventor Takeshi Ken Kobashigawa 2-23-17 Matsuyama, Naha City, Okinawa Inside Tropical Techno Center Co., Ltd. (72) Inventor Yui Tokashiki 2-23-17 Matsuyama, Naha City, Okinawa Tropical Co., Ltd. Examiner at the Techno Center Satoshi Morikawa (56) References JP-A-5-186556 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08G 18/65

Claims (5)

(57) [Claims] 1. The following three components (a), (b) and (c) (a) molasses, (b) polyethylene glycol having an average molecular weight of 200 to 400
Coal or ethylene glycol or glycerin
Et chosen polyol (c) an average molecular weight of 600 to 3000, polyethylene glycol, polypropylene glycol or Poriesu <br/> biodegradable flexible polyurethane Polyol composition comprising a polyol selected from ether polyol. 2. Component (a) is 10 to 25% by weight, (b)
The polyol composition for a biodegradable flexible polyurethane according to claim 1, comprising 25 to 40% by weight of the component and 35 to 65% by weight of the component (c). 3. The polyol composition for a biodegradable flexible polyurethane according to claim 1, which contains 0.1 to 3% by weight of water. 4. The following three components (a), (b) and (c): (a) molasses, (b) polyethylene glycol having an average molecular weight of 200 to 400.
Coal or ethylene glycol or glycerin
La polyol (c) an average molecular weight selected is 600 to 3000, polyethylene glycol, reacted with polypropylene glycol or Poriesu <br/> biodegradable flexible polyurethane Polyol composition comprising a polyol selected from ether polyol, an isocyanate compound A method for producing a biodegradable flexible polyurethane foam. 5. A polyurethane foam produced by the method according to claim 4 .