WO2010104084A1

WO2010104084A1 - Method for producing microorganism carrier made from soft polyurethane foam and microorganism carrier made of soft polyurethane foam

Info

Publication number: WO2010104084A1
Application number: PCT/JP2010/053918
Authority: WO
Inventors: 大輔賀来; 孝之佐々木
Original assignee: 旭硝子株式会社
Priority date: 2009-03-11
Filing date: 2010-03-09
Publication date: 2010-09-16
Also published as: JP5692061B2; TW201036998A; JPWO2010104084A1

Abstract

Provided is a method for producing a microorganism carrier made from a soft polyurethane foam that absorbs a large volume of water and has a low COD load and can be used for purposes such as water purification. Also provided is a microorganism carrier made from a soft polyurethane foam which is produced by means of this method. By means of the method for producing a microorganism carrier made from a soft polyurethane foam, a polyol (I), which comprises a specific polyol (A) or a combination of the polyol (A) and a specific monool (X), and has an oxyethylene group content that accounts for 5 to 50 mass% of the total oxyalkylene groups, and a polyisocyanate compound (II) are reacted in an open system, substantially without the use of a silicone foam regulator and in the presence of a urethane catalyst and a foaming agent. The microorganism carrier made from a soft polyurethane foam is obtained by this production method.

Description

Method for producing microbial carrier made of flexible polyurethane foam and microbial carrier made of flexible polyurethane foam

The present invention relates to a method for producing a flexible polyurethane foam-made microorganism carrier and a flexible polyurethane foam-made microorganism carrier.

Flexible polyurethane foam (hereinafter referred to as “soft foam”) is used in various applications. As a manufacturing method, there are a method in which a polyol and a polyisocyanate compound are reacted in an open system (slab method) and a method in which a polyol and a polyisocyanate compound are reacted in a closed system (mold method). The reaction between the polyol and the polyisocyanate compound is performed in the presence of a urethanization catalyst, a foaming agent, and a foam stabilizer, and a silicone foam stabilizer is widely used as the foam stabilizer. For example, it is known to produce a flexible foam using a dimethylpolysiloxane-polyoxyalkylene copolymer which is a silicone foam stabilizer (Patent Document 1).
However, since the silicone-based foam stabilizer contains a volatile organic compound (VOC), it may bleed out from the foam to generate a strange odor or cause a problem in the surrounding electronic members. Silicone foam stabilizers generally have the highest unit price in the production of flexible foams, and are disadvantageous in terms of economy.

Then, the method shown below is shown as a method of manufacturing a polyurethane foam, without using a silicone type foam stabilizer.
A method of producing a polyurethane foam for use as a soundproofing material in an open system, wherein a polyether polyol having a molecular weight distribution in the range of 1.02 to 1.2 and having a primary hydroxyl group as a terminal group is used (patented) Reference 2).
A method for producing a flexible foam in a closed system, in which propylene oxide is subjected to ring-opening addition polymerization using a double metal cyanide complex catalyst (DMC catalyst), and ethylene oxide is terminated at the end with an alkali metal compound catalyst or a phosphazenium complex. A method using a polyol obtained by ring-opening addition polymerization (Patent Document 3).

On the other hand, in the field of water treatment, it is known to purify wastewater and the like by microbial treatment using activated sludge. However, the method using activated sludge is not suitable for purification of water having a relatively low biochemical oxygen demand (BOD) such as rivers and swamps. In order to purify such water, it is effective to immerse the carrier in water and perform the microbial treatment in a state where the microorganism is supported on the carrier. Therefore, it has been studied to use a flexible foam produced in an open system as a resin-made microorganism carrier. For example, Patent Document 4 discloses a method for producing a flexible foam in the presence of a silicone-based foam stabilizer as a water treatment microorganism carrier. Patent Document 5 discloses a water treatment method using a flexible foam as a microorganism carrier.

Japanese Patent Laid-Open No. 2001-200028 JP 2005-301000 A International Publication No. 2006/054657 Pamphlet JP 2007-111153 A JP 2004-089803 A

However, it turned out that the flexible foam manufactured using the silicone type foam stabilizer like patent document 4 is unsuitable for this use. This is because the flexible foam produced using the silicone foam stabilizer increases the chemical oxygen demand (COD) of the water in which the flexible foam is immersed.
Patent Document 4 does not have a detailed description of a polyol structure suitable for a flexible foam for use as a microorganism support. Furthermore, Patent Document 5 does not describe a method for producing a flexible foam.

Therefore, the use of the polyurethane foam produced without using the silicone-based foam stabilizer of Patent Document 2 as a microorganism carrier was examined. However, since the polyurethane foam obtained by the technique described in Patent Document 2 has a density of 80 kg / m ³ or more and very low air permeability, it is difficult for water to enter the foam, so that it can be used as a microorganism carrier. Was unsuitable.
Similarly, since the flexible foam of Patent Document 3 obtained without using a silicone foam stabilizer is manufactured by a reaction in a closed system, the density is large, and there is a problem similar to that of Patent Document 2. Further, the closed-system reaction conditions in Patent Document 3 cannot be directly applied to an open-system reaction. That is, in general, when the reaction is performed in a closed system, the foaming state is controlled so that the volume of the obtained flexible foam is larger than the volume of the mold to be sealed. Therefore, the reaction conditions are significantly different from those in the case of foaming in an open system.
As described above, in the conventional method, it is difficult to produce a flexible foam that can easily enter water and can be suitably used as a microorganism carrier without using a silicone-based foam stabilizer.

The present invention provides a method for producing a microbial carrier made of flexible polyurethane foam, which has a large water absorption amount and has a low COD load, and can be used for water purification, and a microbial carrier made of flexible polyurethane foam obtained by the production method. The purpose is to do.

The present invention employs the following configuration in order to achieve the above-described problems.
[1] A method in which polyol (I) and polyisocyanate compound (II) are reacted in an open system in the presence of a urethanization catalyst and a foaming agent, substantially without using a silicone foam stabilizer. The urethanization catalyst contains a metal catalyst and an amine catalyst, and the polyol (I) contains the following polyol (A) or a combination of the following polyol (A) and the following monool (X), and the polyol (I ) In which the content of oxyethylene groups in all oxyalkylene groups is 5 to 50% by mass.
Polyol (A): a polyether polyol having a hydroxyl value of 10 to 90 mgKOH / g, obtained by ring-opening addition polymerization of alkylene oxide to an initiator using a double metal cyanide complex catalyst, At least in part, a mixture of ethylene oxide and other alkylene oxides is used.
Monool (X): a polyether monool having a hydroxyl value of 5 to 200 mg KOH / g, obtained by ring-opening addition polymerization of alkylene oxide as an initiator using a double metal cyanide complex catalyst, A mixture of ethylene oxide and another alkylene oxide is used as at least a part of the oxide.
[2] The method for producing a microorganism support for flexible polyurethane foam according to [1], wherein the degree of unsaturation of the polyol (A) is 0.05 meq / g or less.
[3] The method for producing a microorganism-supported body made of flexible polyurethane foam according to [1] or [2], wherein the polyol (I) contains a polymer-dispersed polyol.
[4] The method for producing a microorganism-supported body made of flexible polyurethane foam according to [1] to [3], wherein the primary ratio of the polyol (A) is 5 to 50%.
[5] The method for producing a microbial support of flexible polyurethane foam according to [1] to [4], wherein only water is used as a foaming agent.
[6] A method for producing a microbial support of flexible polyurethane foam according to [1] to [5], wherein the isocyanate index is 90 to 130.
[7] A microorganism support made of a flexible polyurethane foam having a gas permeability of 40 L / min or more, obtained by the method for producing a microorganism support made of a flexible polyurethane foam according to [1] to [6].
[8] A flexible polyurethane foam for a microorganism carrier, obtained by the production method of [1] to [6] and having an air permeability of 40 L / min or more.
[9] The flexible polyurethane foam for a microorganism carrier for purifying water according to [8].

According to the production method of the present invention, it is possible to produce a flexible polyurethane foam-made microorganism carrier that can be suitably used for water purification, which has a large water absorption amount and a low COD load.
Moreover, since the microorganism-supporting body made of the flexible polyurethane foam of the present invention has a large amount of water absorption and a low COD load, it can be suitably used for applications such as water purification.

The method for producing a flexible polyurethane foam-made microorganism carrier (hereinafter simply referred to as “microorganism carrier”) of the present invention comprises a polyol (I) and a polyisocyanate compound (II) in the presence of a urethanization catalyst and a blowing agent. In this method, the silicone-based foam stabilizer is reacted in an open system substantially without using it. That is, the microorganism carrier in the present invention is a microorganism carrier comprising a flexible foam obtained by a reaction in an open system.

<Polyol (I)>
Polyol (I) includes polyol (A) or a combination of polyol (A) and monol (X).
[Polyol (A)]
Polyol (A) is a polyether polyol obtained by ring-opening addition polymerization of alkylene oxide (a2) to initiator (a1) using a double metal cyanide complex catalyst (hereinafter referred to as “DMC catalyst”). Polyoxyalkylene polyol). Therefore, the polyol (A) has a polyoxyalkylene chain obtained by ring-opening addition polymerization of alkylene oxide (a2) with a DMC catalyst.

The initiator (a1) is not particularly limited as long as the polyol used for the production of the flexible foam can be obtained. Examples include polyhydric alcohols, amines having 2 to 6 active hydrogens, high hydroxyl group polyester polyols, high hydroxyl group polycarbonate polyols, and high hydroxyl group polyether polyols. Here, the high hydroxyl value polyol means that the polyol has a hydroxyl value of 110 to 280 mgKOH / g. Among these, a high hydroxyl group polyether polyol is preferable, and a high hydroxyl group polyether polyol having no nitrogen atom is particularly preferable.
Examples of the polyhydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol, and the like.
Examples of amines having 2 to 6 active hydrogens include diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine and the like.
The number of active hydrogens possessed by the initiator (a1) is preferably 2 to 6, and particularly preferably 2, 3 or 4, from the viewpoint of ease of water uptake of microorganisms and microorganisms and processability.
An initiator (a1) may be used individually by 1 type, and may use 2 or more types together.

As the alkylene oxide (a2) to be subjected to ring-opening addition polymerization using a DMC catalyst, a mixture of ethylene oxide and another alkylene oxide is used as at least a part thereof. Examples of alkylene oxides other than ethylene oxide include propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane.
The alkylene oxide (a2) is preferably a combination of ethylene oxide and propylene oxide from the viewpoint of the hydrophilicity and mechanical strength of the microorganism carrier. That is, the polyol (A) is preferably polyoxypropyleneoxyethylene polyol.

In the ring-opening addition polymerization of alkylene oxide (a2), at least a part thereof is subjected to ring-opening addition polymerization using ethylene oxide and another alkylene oxide as a mixture. That is, at least part of the alkylene oxide (a2) is subjected to ring-opening addition polymerization to the initiator (a1) by random copolymerization of ethylene oxide and another alkylene oxide. When the main chain terminal of the polyol (A) is an oxyethylene group, the reactivity of the polyol (A) is very high, and it is difficult to control the reaction in foaming in an open system. On the other hand, when random copolymerization with other alkylene oxides is performed, the amount of oxyethylene groups at the end of the main chain of the polyol (A) can be controlled. That is, the reaction can be controlled in foaming in an open system by random copolymerization of ethylene oxide and other alkylene oxides. In addition, when alkylene oxide (a2) undergoes ring-opening addition polymerization of an alkylene oxide other than ethylene oxide alone, the air permeability of the resulting flexible foam and microbial support tends to be difficult to improve, whereas ethylene oxide, Breathability can be improved by random copolymerization with other alkylene oxides. The polyol (A) has an oxyalkylene random chain of ethylene oxide and other alkylene oxide obtained using a DMC catalyst.

In the ring-opening addition polymerization of alkylene oxide (a2), the proportion of the reaction of ethylene oxide with another alkylene oxide as a mixture is preferably 50% by mass or more with respect to the total (100% by mass) of alkylene oxide (a2). 80 mass% or more is more preferable, and 100 mass% is particularly preferable. That is, it is preferable to use a mixture of ethylene oxide and another alkylene oxide as all of the alkylene oxide (a2). In this case, all oxyalkylene chains based on the alkylene oxide (a2) are oxyalkylene random chains.
Further, in the case where all of the alkylene oxide (a2) is not the above mixture, it is preferred that the ethylene oxide is subjected to ring-opening addition polymerization only as a mixture with other alkylene oxides, and the other alkylene oxides alone are subjected to ring-opening addition polymerization. That is, as described above, when the main chain terminal is only an oxyethylene group, it is difficult to control the reaction of the polyol (A). Therefore, it is preferable to finally perform ring-opening addition polymerization of another alkylene oxide alone. .

The ethylene oxide content with respect to the total amount of alkylene oxide (a2) is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 20 to 50% by mass. When the content is 5% by mass or more, a microorganism-supporting body excellent in hydrophilicity is easily obtained. In addition, when the content is 80% by mass or less, it is easy to produce a microorganism carrier without substantially using a silicone-based foam stabilizer, and a microorganism carrier excellent in mechanical strength such as tear strength is obtained. It is easy to be done.

As the DMC catalyst, for example, those described in JP-B-46-27250 can be used. Specifically, for example, a complex mainly composed of zinc hexacyanocobaltate can be mentioned, and an ether and / or alcohol complex thereof is preferable.
Examples of ethers include ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether (diglyme), ethylene glycol mono-tert-butyl ether (METB), ethylene glycol mono-tert-pentyl ether (METP), diethylene glycol mono-tert-butyl ether (DETB), Tripropylene glycol monomethyl ether (TPME) is preferred.
As the alcohol, tert-butyl alcohol is preferred.

As the DMC catalyst, zinc hexacyanocobaltate-tert-butyl alcohol complex, zinc hexacyanocobaltate-ethylene glycol dimethyl ether complex, from the viewpoint of high effect of suppressing cell roughening and foam shrinkage of the resulting microbial support (soft foam), Zinc hexacyanocobaltate-diethylene glycol mono-tert-butyl ether complex is preferred.

A polyol produced using a DMC catalyst is a polyol having a narrower molecular weight distribution than a polyol produced using another catalyst. A polyol having a narrow molecular weight distribution has a similar average molecular weight (polyol having the same hydroxyl value) and a lower viscosity than a polyol having a wide molecular weight distribution. Therefore, the polyol (A) is excellent in miscibility with other raw materials in the urethanization reaction, and is excellent in foam stability during production of the microorganism carrier. Moreover, since there are few low molecular weight monools, durability of the obtained flexible foam and microorganism support body improves.

The amount of the DMC catalyst used is preferably 0.001 to 0.1 parts by mass, with 0.003 to 0 parts by mass, where the total mass of the initiator (a1) and the alkylene oxide (a2) is 100 parts by mass. More preferably, it is 0.03 parts by mass.
If the amount of the DMC catalyst used is 0.001 part by mass or more, the foaming stability during the production of the microorganism carrier is improved, and cell roughening and foam shrinkage are easily suppressed. Moreover, if the said usage-amount of a DMC catalyst is 0.1 mass part or less, it will be easy to control the reaction rate of the ring-opening addition polymerization at the time of polyol manufacture.

The average number of hydroxyl groups in the polyol (A) is preferably 2 to 6, and more preferably 2.2 to 3.5. However, the average number of hydroxyl groups in the polyol (A) means the average number of active hydrogens in the initiator (a1) (the same applies hereinafter).
When the average number of hydroxyl groups of the polyol (A) is 2 or more, the hardness of the foam is appropriately increased and the workability is improved. Moreover, if the average number of hydroxyl groups is 6 or less, the mechanical strength of the obtained microorganism carrier is improved, and it is easy to suppress the hardness from becoming too high.

The hydroxyl value of the polyol (A) is 10 to 90 mgKOH / g, and preferably 10 to 60 mgKOH / g.
If the hydroxyl value of the polyol (A) is 10 mgKOH / g or more, collaps etc. can be suppressed and the microorganism carrier can be produced stably. Moreover, if the hydroxyl value is 90 mgKOH / g or less, the workability of the resulting microorganism carrier is improved.

The unsaturation degree of the polyol (A) is preferably 0.05 meq / g or less, more preferably 0.01 meq / g or less, and further preferably 0.008 meq / g or less. If the degree of unsaturation is 0.05 meq / g or less, a low molecular weight monool produced as a by-product can be reduced and a polyol having a narrow molecular weight distribution can be obtained. Therefore, the durability of the flexible foam and the microorganism carrier in water is improved. improves.
The lower limit of the degree of unsaturation is ideally 0 meq / g. The degree of unsaturation can be measured by a method based on JIS K1557 (1970 edition).

The polyol (A) may be a polymer-dispersed polyol. However, the polyol (A) being a polymer-dispersed polyol means a dispersion system in which polymer fine particles (dispersoid) are stably dispersed using the polyol (A) as a base polyol (dispersion medium). That is, the hydroxyl value of the polymer-dispersed polyol in the present invention is the hydroxyl value of the polyol (A) of the base polyol.
When polymer fine particles are present in a polyol, the hydroxyl value of the polyol is generally lower than that of the base polyol. Therefore, if the polyol (A) is a polymer-dispersed polyol, the mechanical properties such as the hardness of the microorganism carrier are improved, and the hydroxyl value is reduced compared with the case where the hydroxyl value is lowered without dispersing the polymer fine particles. This is advantageous in terms of stability.

Examples of the polymer that can be used as the polymer fine particles include addition polymerization polymers and condensation polymerization polymers. Of these, addition polymerization polymers are preferred.
Examples of the addition polymerization polymer include a polymer obtained by homopolymerizing monomers such as acrylonitrile, styrene, methacrylic acid ester, and acrylic acid ester, or a polymer obtained by copolymerization.
Examples of the condensation polymerization polymer include polyester, polyurea, polyurethane, and polymethylol melamine.

The content of the polymer fine particles in the polymer-dispersed polyol is preferably 5 to 50% by mass with respect to 100% by mass of the polyol (A). If the content of the polymer fine particles is 5% by mass or more, the effect of improving the mechanical properties of the microorganism-supporting body is easily obtained. Moreover, if content of a polymer fine particle is 50 mass% or less, the increase in the viscosity of a polymer dispersion | distribution polyol can be suppressed. When the polymer-dispersed polyol is used, the content of the polymer fine particles in the polyol (I) is preferably more than 0% by mass and 50% by mass or less, and more preferably 1 to 10% by mass.
However, various properties (unsaturation, hydroxyl value, oxyethylene group content, etc.) of the polymer-dispersed polyol as a polyol are considered with respect to the base polyol (polyol (A)) excluding polymer fine particles.

In the production method of the present invention, a flexible foam and a microorganism carrier are produced by substantially including no silicone foam stabilizer by incorporating polyol (I) into polyol (I) using a DMC catalyst. it can.
Since ring-opening addition polymerization of alkylene oxide to the initiator occurs from the primary carbon side when a catalyst other than the DMC catalyst is used, the resulting polyol has a terminal secondary hydroxyl group. On the other hand, as a result of studies by the present inventors, it was found that when alkylene oxide was subjected to ring-opening addition polymerization with an initiator using a DMC catalyst, the direction of addition of alkylene oxide was partially reversed. For example, when propylene oxide is subjected to ring-opening addition polymerization to an initiator using a DMC catalyst, propylene oxide is added from the primary carbon side and also from the secondary carbon side at a rate of about 15%, and the terminal is 1 A certain amount of polyol which is a primary hydroxyl group is obtained.

In the present invention, at least a part of the alkylene oxide (a2) used for the polyol (A) includes random copolymerization of ethylene oxide and other alkylene oxides. In the case where all of the alkylene oxide (a2) is the random copolymerization, since the reaction rate of ethylene oxide and other alkylene oxides is high, other alkylene oxides come to the end of the main chain of the polyol (A). The probability is very high. When ring-opening polymerization is performed using a DMC catalyst, a part of the main chain ends become primary hydroxyl groups due to partial inversion of the direction of ring-opening addition polymerization. As a result, the surface activity of the polyoxyalkylene chain changes, and an appropriate surface tension can be obtained during foam foaming. For this reason, it is considered that a flexible foam can be foamed without using a silicone-based foam stabilizer, and a microorganism carrier can be produced.

Moreover, when producing the flexible foam used as a microorganism support body, since the urethanation reaction and foaming by a polyol and a polyisocyanate compound occur competitively, it is necessary to appropriately control the speed of the urethanization reaction. The speed of the urethanization reaction affects whether the hydroxyl group at the end of the polyol is a primary hydroxyl group or a secondary hydroxyl group. For this reason, the polyol (A) preferably has a primary conversion rate (ratio where the terminal is a primary hydroxyl group) of 5 to 50%. In particular, in the slab method to be described later in the method for producing a microorganism-supported body of the present invention, it is preferable to control the degree of primaryization to a certain extent from the viewpoint of good foam moldability.
The primary rate of polyol (A) can be controlled by the content of ethylene oxide in the alkylene oxide (a2) used, the type of DMC catalyst, and the like.

[Monoall (X)]
Monool (X) is a polyether monool obtained by ring-opening addition polymerization of alkylene oxide (x2) to an initiator (x1) having an active hydrogen number of 1 using a DMC catalyst.

Examples of the initiator (x1) include monools such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and tert-butyl alcohol; monohydric phenols such as phenol and nonylphenol; dimethylamine, Secondary amines such as diethylamine can be mentioned.
Further, polyether monool obtained by ring-opening addition polymerization of alkylene oxide to the compound can also be used.
An initiator (x1) may be used individually by 1 type, and may use 2 or more types together.
As the initiator (x1), monools or polyether monools are preferably used.

As the alkylene oxide (x2) to be subjected to ring-opening addition polymerization using a DMC catalyst, a mixture of ethylene oxide and another alkylene oxide is used as at least a part thereof. Examples of alkylene oxides other than ethylene oxide include propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane.
The alkylene oxide (x2) is preferably a combination of ethylene oxide and propylene oxide from the viewpoint of the hydrophilicity and mechanical strength of the microorganism carrier. That is, it is preferable that monool (X) is polyoxypropylene oxyethylene monool.

For the same reason as the ring-opening addition polymerization of alkylene oxide (a2) in polyol (A), at least a part of the ring-opening addition polymerization of alkylene oxide (x2) is opened to initiator (x1) by random copolymerization. Cycloaddition polymerization is performed. Monool (X) has an oxyalkylene random chain of ethylene oxide and other alkylene oxide obtained using a DMC catalyst.

The ethylene oxide content relative to the total amount of alkylene oxide (x2) is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 20 to 50% by mass. When the content is 5% by mass or more, a microorganism-supporting body excellent in hydrophilicity is easily obtained. In addition, when the content is 80% by mass or less, it is easy to produce a microorganism carrier without substantially using a silicone-based foam stabilizer, and a microorganism carrier excellent in mechanical strength such as tear strength is obtained. It is easy to be done.

In the ring-opening addition polymerization of alkylene oxide (x2), the proportion of the reaction of ethylene oxide and another alkylene oxide as a mixture is preferably 50% by mass or more with respect to the entire alkylene oxide (x2) (100% by mass). 80 mass% or more is more preferable, and 100 mass% is particularly preferable. That is, it is preferable to use a mixture of ethylene oxide and another alkylene oxide as all of the alkylene oxide (x2). In this case, all oxyalkylene chains based on the alkylene oxide (x2) are oxyalkylene random chains.
Further, when all of the alkylene oxide (x2) is not the above mixture, it is preferable that ethylene oxide is subjected to ring-opening addition polymerization only as a mixture with other alkylene oxides, and the other alkylene oxides alone are subjected to ring-opening addition polymerization. That is, if the main chain terminal is only an oxyethylene group as described above in the section of polyol (A), it is difficult to control the reaction of monool (X). It is preferable to perform ring-opening addition polymerization.

As the DMC catalyst used for the production of the monool (X), the same DMC catalyst used for the production of the polyol (A) can be used.
The amount of the DMC catalyst used is preferably 0.001 to 0.1 parts by mass, with 0.003 to 0 parts by mass, where the total mass of the initiator (x1) and the alkylene oxide (x2) is 100 parts by mass. More preferably, it is 3 parts by mass.
If the amount of the DMC catalyst used is 0.001 part by mass or more, the foaming stability during the production of the microorganism carrier is improved, and cell roughening and foam shrinkage are easily suppressed. Moreover, if the said usage-amount of a DMC catalyst is 0.1 mass% or less, it will be easy to control the reaction rate of the ring-opening addition polymerization at the time of monool manufacture.

The average number of hydroxyl groups of monool (X) is 1.
The hydroxyl value of monool (X) is 5 to 200 mgKOH / g, preferably 5 to 120 mgKOH / g.
If the hydroxyl value of monool (X) is 5 mgKOH / g or more, collaps etc. can be suppressed and a microorganism carrier can be manufactured more stably. Moreover, if a hydroxyl value is 200 mgKOH / g or less, the workability of the microorganism support body obtained will improve.

Similarly to polyol (A), when all of alkylene oxide (x2) is the random copolymer, monool (X) has another alkylene oxide at the end of the main chain of monool (X). Since the probability is very high and ring-opening addition polymerization is performed using a DMC catalyst, a part of the main chain end becomes a primary hydroxyl group due to partial inversion of the direction of the ring-opening addition polymerization. As a result, the surface activity of the polyoxyalkylene chain changes, and an appropriate surface tension can be obtained during foam foaming. For this reason, it is thought that a flexible foam can be foamed without using a foam stabilizer and a microorganism carrier can be produced.
The primary rate of monool (X) is preferably 5 to 50%. The primary rate of monool (X) can be controlled by the content of ethylene oxide in the alkylene oxide (x2) used, the type of DMC catalyst, and the like.

The polyol (I) may contain the polyol (B) and / or monool (Y) shown below.
[Polyol (B)]
The polyol (B) is a polyol other than the polyol (A). That is, the polyol (B) is a polyol having no oxyalkylene random chain of ethylene oxide and another alkylene oxide obtained using a DMC catalyst, or ethylene oxide and other alkylene oxide obtained using a DMC catalyst. And a hydroxyl value outside the range of 10 to 90 mgKOH / g.
As the polyol (B), those usually used for the production of flexible foam other than the polyol (A) can be used. The polyol (I) preferably contains at least the polyol (B1) shown below as the polyol (B).

(Polyol (B1))
Polyol (B1) is obtained by ring-opening addition polymerization of alkylene oxide (b1-2) to initiator (b1-1) using an alkylene oxide ring-opening addition polymerization catalyst other than a DMC catalyst. The average number of hydroxyl groups is 2. A polyether polyol having a hydroxyl value of 15 to 250 mgKOH / g.
The alkylene oxide ring-opening addition polymerization catalyst other than the DMC catalyst is preferably a phosphazenium complex compound or a Lewis acid compound, and more preferably an alkali metal compound catalyst.
Examples of the alkali metal compound catalyst include potassium hydroxide (KOH), cesium hydroxide (CsOH), and the like.

The initiator (b1-1) is a compound having 2 to 6 active hydrogen atoms. For example, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin. And polyhydric alcohols such as pentaerythritol and sorbitol; polyhydric phenols such as bisphenol A; and amines such as monoethanolamine, diethanolamine, triethanolamine, and piperazine. Of these, polyhydric alcohols are preferable. Moreover, you may use the high hydroxyl value polyether polyol obtained by carrying out ring-opening addition polymerization of alkylene oxide to these compounds using catalysts other than the above-mentioned DMC catalyst.
As the initiator (b1-1), one type may be used alone, or two or more types may be used in combination.

Examples of the alkylene oxide (b1-2) include ethylene oxide, propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane. Of these, combined use of propylene oxide and ethylene oxide is preferable from the viewpoint of the hydrophilicity and mechanical strength of the resulting microorganism-supported body.

In the ring-opening addition polymerization of alkylene oxide (b1-2), it is preferable to perform ring-opening addition polymerization using ethylene oxide and propylene oxide as a mixture at least in part. That is, at least a part of the alkylene oxide (b1-2) is preferably subjected to ring-opening addition polymerization to the initiator (b1-1) by random copolymerization. When propylene oxide alone is subjected to ring-opening addition polymerization as part of alkylene oxide (b1-2), the air permeability of the resulting flexible foam and microbial support tends to be difficult to improve, whereas ethylene oxide and propylene oxide Breathability can be improved by random copolymerization.

In the ring-opening addition polymerization of alkylene oxide (b1-2), the proportion of the reaction of ethylene oxide and propylene oxide as a mixture is 50% by mass or more with respect to the total (100% by mass) of alkylene oxide (b1-2). Is preferable, 80 mass% or more is more preferable, and 100 mass% is particularly preferable. That is, it is preferable to use a mixture of ethylene oxide and propylene oxide as all of the alkylene oxide (b1-2). In this case, all oxyalkylene chains based on the alkylene oxide (b1-2) are oxyalkylene random chains.
The content of ethylene oxide with respect to the total amount of alkylene oxide (b1-2) is preferably 10 to 90% by mass, more preferably 20 to 85% by mass.

The average number of hydroxyl groups of the polyol (B1) is 2-6. By setting the average number of hydroxyl groups to 2 to 6, it is possible to balance the durability, hardness, and mechanical strength of the resulting microorganism carrier.
The hydroxyl value of the polyol (B1) is 15 to 250 mgKOH / g, preferably 20 to 200 mgKOH / g. When the hydroxyl value is 15 mgKOH / g or more, the microorganism carrier can be stably produced by suppressing collapse and the like. Moreover, if the hydroxyl value is 250 mgKOH / g or less, a microorganism carrier having excellent mechanical strength can be obtained.

The polyol (B1) may be a polymer-dispersed polyol. Examples of the polymer of the polymer fine particles include the same as those described for the polyol (A). The content of the polymer fine particles in the polymer-dispersed polyol is preferably 5 to 50% by mass, and more preferably 20 to 50% by mass with respect to the total amount of the polyol (B1).

(Polyol (B2))
The polyol (I) may contain a polyol (B2) as the polyol (B) in addition to the polyol (B1). The polyol (B2) is a polyol other than the polyol (A) or the polyol (B1).

[Monoall (Y)]
Monool (Y) is a monool other than monool (X). That is, the monool (Y) is a monool having no oxyalkylene chain of ethylene oxide and another alkylene oxide obtained by using a DMC catalyst, or ethylene oxide and other alkylene obtained by using a DMC catalyst. Monool having an oxyalkylene random chain with oxide and having a hydroxyl value outside the range of 5 to 200 mgKOH / g.

[Polyol (I)]
Polyol (I) in the present invention includes polyol (A) or a combination of polyol (A) and monol (X). The combination of the polyol (A) and the monool (X) improves the air permeability of the microorganism carrier obtained from the polyol (A). In addition, polyol (B) or monool (Y) may be contained. That is, the polyol (I) in the present invention is one of the combinations shown below.

(1) Polyol (I) containing only polyol (A) as a polyol (polyol (A) alone system).
(1a) Polyol (I) consisting only of polyol (A)
(1b) Polyol (I) comprising polyol (A) and monool (X)
(1c) Polyol (I) comprising polyol (A) and monool (Y)
(1d) Polyol (I) comprising polyol (A), monool (X) and monool (Y)

(2) Polyol (I) (polyol combined system) in which polyol (A) and polyol (B) are used in combination as polyol.
(2a) Polyol (I) comprising polyol (A) and polyol (B)
(2b) Polyol (I) comprising polyol (A), polyol (B) and monool (X)
(2c) Polyol (I) comprising polyol (A), polyol (B) and monool (Y)
(2d) Polyol (I) comprising polyol (A), polyol (B), monool (X) and monool (Y)

In the polyol (A) single system of (1), the mass ratio of the polyol (A) in the polyol (I) (100 mass%) is preferably 75 mass% or more, and preferably 80 mass% or more. More preferred.
The mass ratio of the monool (X) in the polyol (I) is preferably 30 parts by mass or less and more preferably 25 parts by mass or less with respect to 100 parts by mass of the polyol (A).
The mass ratio of the monool (Y) in the polyol (I) is preferably 30 parts by mass or less and more preferably 25 parts by mass or less with respect to 100 parts by mass of the polyol (A).
In the polyol alone system of (1), the microorganism carrier is substantially used without using a silicone foam stabilizer by setting the polyol (A), monool (X), and monool (Y) within the above range. It becomes easy to manufacture. Moreover, it is easy to obtain a microorganism carrier having excellent hydrophilicity, water and microorganisms and good mechanical strength.

In the polyol combination system (2), the mass ratio of the polyol (A) to the total mass (100 mass%) of the polyol (A) and the polyol (B1) is preferably 10 to 90 mass%, More preferably, it is 80 mass%.
The total mass ratio of the polyol (A) and the polyol (B1) in the polyol (I) (100% by mass) is preferably 75% by mass or more, more preferably 80% by mass or more. preferable.
By making the total mass ratio of the polyol (A) and the polyol (B1) in the polyol (I) within the above range, a microorganism carrier can be produced without substantially using a silicone foam stabilizer. It becomes easy. Moreover, it is easy to obtain a microorganism carrier having excellent hydrophilicity, water and microorganisms and good mechanical strength.

The mass ratio of the monool (X) is preferably 30 parts by mass or less and 25 parts by mass or less with respect to the total mass (100 parts by mass) of the polyol (A) and the polyol (B1). More preferred.
The mass ratio of the monool (Y) is preferably 30 parts by mass or less and 25 parts by mass or less with respect to the total mass (100 parts by mass) of the polyol (A) and the polyol (B1). More preferred.
By setting the mass ratio of monool (X) and monool (Y) within the above range, a microorganism carrier having excellent durability in water and good air permeability can be easily obtained.

Specific examples of suitable compositions of polyol (I) in the polyol combination system (2) include 50 to 95 parts by weight of polyol (A), 5 to 50 parts by weight of polyol (B1), and 0 for polyol (B2). To 10 parts by mass, 0 to 30 parts by mass of monool (X), and 0 to 30 parts by mass of monool (Y) (however, the total of the polyols (A) and (B1) is 100 parts by mass) Is).

In the polyol (I), the content of oxyethylene groups in all oxyalkylene groups contained in the polyol (I) is 5 to 50% by mass in any of the combinations described above. For example, in the case of polyol (I) composed of polyol (A) and polyol (B), polyol (A) and polyol (B) with respect to the total amount of all oxyalkylene groups possessed by polyol (A) and polyol (B) ) Content of all oxyethylene groups in the range of 5 to 50% by mass. When the polyol (I) contains a monool, the monool is also considered.
When the content of the oxyethylene group is 5% by mass or more, a microorganism carrier having excellent hydrophilicity can be obtained. Moreover, if the said content of an oxyethylene group is 50 mass% or less, a microorganisms carrier can be manufactured without using a silicone type foam stabilizer substantially.
The content of the oxyethylene group is adjusted by adjusting the amount of ethylene oxide in the total alkylene oxide to be subjected to ring-opening addition polymerization by the initiator.
In addition, in the polyol (I), in the case of any combination described above, when the monool (X) is used, the mass ratio of the monool (X) in the polyol (I) is the polyol (I). It is preferably 1 part by mass or more, and more preferably 2 parts by mass or more, based on 100 parts by mass of the total amount of polyols such as the polyol (A). The upper limit of the mass ratio of monool (X) is as described above.

<Polyisocyanate compound (II)>
As the polyisocyanate compound (II), those capable of obtaining a flexible foam by reacting with the polyol (I) can be used. For example, an aromatic, alicyclic or aliphatic polyisocyanate compound having two or more isocyanate groups, a mixture of two or more of the above polyisocyanate compounds, or the polyisocyanate compound or polyisocyanate compound mixture may be modified. The modified polyisocyanate obtained in this way is mentioned.

Examples of the polyisocyanate compound include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate. (HMDI).
Examples of the modified polyisocyanate include a prepolymer type modified product, a nurate modified product, a urea modified product, and a carbodiimide modified product of the polyisocyanate compound.

The polyisocyanate compound (II) is preferably TDI, MDI, crude MDI, TDI modified product, MDI modified product, or crude MDI modified product. Especially, it is more preferable to use TDI, a TDI modified body, a crude MDI, or a crude MDI modified body (especially a crude MDI prepolymer modified body is preferable) from the viewpoint of improving foaming stability, durability, and the like. . Among the TDI, crude MDI and modified products thereof, it is preferable to use a polyisocyanate compound having a relatively low reactivity from the viewpoint of excellent air permeability of the obtained microorganism carrier. Examples thereof include a TDI mixture having 2,4-TDI / 2,6-TDI = 80/20% by mass, or a TDI mixture having a large proportion of 2,6-TDI (particularly preferably 30% by mass or more).

In the production method of the present invention, the isocyanate index of the polyol (I) to be reacted and the polyisocyanate compound (II) is preferably 90 to 130, more preferably 95 to 110, and more preferably 100 to 110. More preferably. However, the isocyanate index means 100 times the numerical value obtained by dividing the equivalent of the isocyanate group of the polyisocyanate compound (II) by the total equivalent of all active hydrogen atoms such as polyol (I) and water.
When the isocyanate index is 90 or more, a microorganism-supporting body excellent in durability in water can be easily obtained. Moreover, the urethanization catalyst mentioned later is hard to disperse | distribute and the flexible foam and microorganisms carrier which are obtained become difficult to discolor.

<Foam stabilizer>
The production method of the present invention is characterized in that the reaction between the polyol (I) and the polyisocyanate compound (II) is carried out without substantially using a silicone foam stabilizer. However, substantially not using a silicone foam stabilizer means that the silicon content in the silicone foam stabilizer is 0.05 mass% or less with respect to 100 mass% of the polyol (I). . The silicon content in the silicone foam stabilizer relative to 100% by mass of the polyol (I) is preferably 0.03% by mass or less, and particularly preferably zero.
The silicone foam stabilizer contained in the microorganism carrier can be detected by gas chromatography analysis or the like. More specifically, a method of immersing a microbial support in a solvent such as THF (tetrahydrofuran), extracting the solution into the solvent and analyzing the extract, and heating the microbial support (for example, 200 ° C. or higher) to analyze volatile matter And the like.
In the production method of the present invention, a foam stabilizer other than the silicone foam stabilizer may be used, but it is more preferable not to use a foam stabilizer other than the silicone foam stabilizer.

<Urethane catalyst>
The reaction between polyol (I) and polyisocyanate compound (II) is carried out in the presence of a urethanization catalyst.
The urethanization catalyst is a catalyst that promotes the urethanization reaction, and includes a metal catalyst and an amine catalyst. By using a metal catalyst and an amine catalyst in combination as a urethanization catalyst, a microorganism-supporting body having an excellent cell state in an open system can be produced.

Examples of the metal catalyst include carboxylic acid metal salts such as potassium acetate, potassium 2-ethylhexanoate and tin 2-ethylhexanoate, and examples of the organic metal compound include tin acetate, tin octylate, tin oleate, tin laurate, Examples include dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, lead octoate, lead naphthenate, nickel naphthenate, and cobalt naphthenate.

Examples of the amine catalyst include triethylamine, tripropylamine, polyisopropanolamine, tributylamine, trioctylamine, hexamethyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, diethylenetriamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropylenediamine, N, N, N ′, N′-tetramethylbutanediamine, N, N, N ′, N′— Tetramethyl-1,3-butanediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, bis [2- (N, N-dimethylamino) ethyl] ether, N, N-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-pe Tamethyldiethylenetriamine, triethylenediamine; organic and inorganic salts of the above compounds; oxyalkylene adducts of amino groups of primary and secondary amines; azacyclic compounds such as N, N-dialkylpiperazines; various N, N ′ , N ″ -trialkylaminoalkylhexahydrotriazines.

The amount of the metal catalyst used as the urethanization catalyst varies somewhat depending on the type of polyol (I) used, but is preferably 0.1 to 2.0 parts by mass with respect to 100 parts by mass of polyol (I). More preferably, it is 0.3 to 1.5 parts by mass.
The amount of the amine catalyst used as the urethanization catalyst is preferably 0.1 to 1.5 parts by weight, and preferably 0.2 to 1.0 parts by weight with respect to 100 parts by weight of the polyol (I). Is more preferable.

<Foaming agent>
Examples of the foaming agent include known foaming agents such as water, inert gas, and fluorinated hydrocarbon. Especially, it is preferable to use water and an inert gas, and it is more preferable to use water. Examples of the inert gas include air, nitrogen, and carbon dioxide gas.
As the blowing agent, it is particularly preferable to use only water.

The amount of the foaming agent used is preferably 10 parts by mass or less, and 0.1 to 4 parts by mass or less with respect to 100 parts by mass of the polyol (I) when water is used as the foaming agent. Is more preferable.

<Other additives>
In the production of the microorganism carrier of the present invention, additives other than the urethanization catalyst and the foaming agent may be used.
Examples of additives include fillers such as potassium carbonate and barium sulfate; surfactants such as emulsifiers; anti-aging agents such as antioxidants and UV absorbers; Agents, colorants, antifungal agents, foam breakers, dispersants, anti-discoloring agents.

<Reaction>
As a method for mixing each component, a method (slab method) is used in which each component is mixed in an open system and the reactive mixture is foamed. The slab method is preferable because a homogeneous microorganism carrier can be easily produced. Specific examples include known methods such as a one-shot method, a semi-prepolymer method, and a prepolymer method. Moreover, the manufacture apparatus normally used for manufacture of a flexible foam can be used for manufacture of a microorganisms carrier.

In the production method of the present invention described above, a polyol (A) obtained by subjecting an alkylene oxide to ring-opening addition polymerization to an initiator using a DMC catalyst, or a combination of a polyol (A) and a monool (X) is used. By using it, the microorganism carrier can be produced in an open system without substantially using a silicone foam stabilizer. Thereby, the increase in the COD load derived from the silicone foam stabilizer can be suppressed.
In general, in the production of a flexible foam, a urethanization reaction by a hydroxyl group of a polyol and an isocyanate group of a polyisocyanate compound and foaming by a foaming agent occur competitively. Therefore, in order to control the foaming stability, the cell state, the suppression of shrinkage of the obtained foam, etc., it is necessary to examine the types and amounts of suitable silicone foam stabilizers depending on the foaming conditions. However, in the present invention, since a microorganism carrier can be produced without using a silicone-based foam stabilizer, it is also effective that such a study is not required.

The measurement of the COD load of the microorganism carrier can be performed by the following method.
The microorganism carrier is cut into a cube having a side of 1 cm. 10 g of the cut foam sample is immersed in 200 mL of distilled water for 5 days. About the distilled water used for immersion, the oxygen consumption by the potassium permanganate in 100 degreeC is measured by the method based on JISK0102. Hereinafter, the COD measured by the method is particularly referred to as COD _Mn .
The microorganism carrier in the present invention preferably has a COD _Mn of 100 mg / L or less, more preferably 0 to 80 mg / L. When the COD _Mn is 100 mg / L or less, the microorganism carrier can be suitably used for uses such as water purification. The COD _Mn can be adjusted by the amount of the silicone foam stabilizer used in the production of the microorganism carrier, and can be 100 mg / L or less if the silicone foam stabilizer is not substantially used.

In addition, the flexible foam and the microorganism carrier in the present invention preferably have a water absorption amount of 30 g or more, and more preferably 40 g or more, in a water absorption test based on JIS A9511, from the viewpoint of excellent hydrophilicity. There is no particular upper limit, but 500 g or less is preferable in consideration of the balance with air permeability.
The water absorption amount of the flexible foam and the microorganism carrier in the present invention increases when the hydrophilic property and air permeability of the flexible foam and the microorganism carrier in the present invention are high. It can be adjusted by the hydroxyl value of the polyol and monool used, the content of oxyethylene groups in all oxyalkylene groups in the polyol composition, and the like. Specifically, the smaller the hydroxyl value of the polyol and monool, the better the air permeability of the microorganism carrier and the greater the water absorption. Moreover, the greater the content of oxyethylene groups, the better the hydrophilicity of the microorganism carrier and the greater the amount of water absorption.

The air permeability of the flexible foam and the microorganism carrier is preferably 40 L / min or more, and more preferably 60 L / min or more. When the air permeability is 40 L / min or more, it is easy to obtain a flexible foam and a microorganism carrier having a water absorption of 30 g or more. Although there is no upper limit in particular, 100,000 L / min or less is preferable when the balance with the amount of water absorption is taken into consideration.
The air permeability is measured by a method based on the method B of JIS K6400 (1997 edition).
The air permeability of the flexible foam and the microorganism carrier can be adjusted by the hydroxyl value of the polyol and monool used, the content of oxyethylene groups, and the like. As the hydroxyl value of the polyol and monool is smaller, the polyoxyalkylene chain tends to be longer and the air permeability tends to be improved.

The tear strength of the flexible foam and the microorganism carrier is preferably 2.0 N / cm or more, and more preferably 3.0 N / cm or more. If the tear strength is 2.0 N / cm or more, the workability of the foam is improved. Although there is no particular upper limit, it is preferably 30 N / cm or less in consideration of microorganism fixation and ease of handling of the carrier.
The tear strength is measured by a method based on JIS K6400 (1997 edition).
The tear strength of the flexible foam and the microorganism carrier can be adjusted by the average number of hydroxyl groups of the polyol and monool used and the amount of the polymer-dispersed polyol added.

Moreover, it is preferable that the flexible foam and the microorganism carrier have excellent durability expressed by compression residual strain and wet heat compression residual strain. The wet heat compression residual strain is an index of durability in a steamed state. Both compression residual strain and wet heat compression residual strain are measured by a method in accordance with JIS K6400 (1997 edition).
The compressive residual strain of the flexible foam and the microorganism carrier is preferably 5% or less, more preferably 4% or less, and further preferably 3.5% or less. The wet heat compression residual strain of the flexible foam and the microorganism carrier is preferably 5% or less, more preferably 4% or less, and further preferably 3.5% or less.

The core density of the flexible foam and the microorganism carrier is preferably 15 to 110 kg / m ³ , and more preferably 40 to 80 kg / m ³ . The core density is measured by a method based on JIS K6400 (1997 edition).

The microorganism carrier in the present invention is preferably used for water purification such as wastewater treatment of sewage, low BOD (biochemical oxygen demand) water treatment of rivers, swamps, etc., and purification of low BOD water. It is more preferable to use for.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following description.
The raw materials used for the production of the microorganism carrier are shown below.
[Polyol (I)]
(Polyol (A))
Polyol A1: Polyoxypropylene polyol having a hydroxyl value of 160 mgKOH / g obtained by ring-opening addition polymerization of propylene oxide to glycerol using a potassium hydroxide catalyst and purifying with magnesium silicate is used as an initiator (a1). It was. The polyoxypropylene polyol is subjected to ring-opening addition polymerization of a mixture of ethylene oxide (EO) and propylene oxide (PO), which are alkylene oxides (a2), using a zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst which is a DMC catalyst. Thus, polyoxypropyleneoxyethylene polyol (polyol A1) was obtained.
Polyol A1 has an average number of hydroxyl groups of 3, a hydroxyl value of 45 mg KOH / g, an unsaturation of 0.005 meq / g, and a primary rate of 12%. The content of oxyethylene groups in all oxyalkylene groups is 24 mass%, and EO and PO are randomly added.

Polyol A2: Polyoxypropylene polyol having a hydroxyl value of 160 mgKOH / g obtained by subjecting glycerin to ring-opening addition polymerization of propylene oxide using potassium hydroxide catalyst and purification with magnesium silicate is used as an initiator (a1). It was. A polyoxypropylene oxyethylene polyol is obtained by subjecting the polyoxypropylene polyol to ring-opening addition polymerization of a mixture of EO and PO, which is an alkylene oxide (a2), using a zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst which is a DMC catalyst. (Polyol A2) was obtained.
Polyol A2 has an average number of hydroxyl groups of 3, a hydroxyl value of 56 mgKOH / g, an unsaturation of 0.005 meq / g, and a primary rate of 7%. The content of oxyethylene groups in all oxyalkylene groups is 7 mass%, and EO and PO are randomly added.

Polyol A3: A polymer-dispersed polyol having an amount of fine particle polymer of 42% by mass, an average number of hydroxyl groups of 3, and a hydroxyl value of 32 mgKOH / g, obtained by copolymerizing acrylonitrile and styrene in polyol A2.

(Polyol (B))
Polyol B1-1: A mixture of EO and PO, which is an alkylene oxide (b1-2), is subjected to ring-opening addition polymerization with glycerin, which is an initiator (b1-1), using a potassium hydroxide catalyst, and polyoxypropyleneoxy Ethylene polyol (polyol B1-1) was obtained.
Polyol B1-1 has an average number of hydroxyl groups of 3, a hydroxyl value of 48 mg KOH / g, a primary conversion rate of 50%, the content of oxyethylene groups in all oxyalkylene groups is 80% by mass, PO is randomly added.

Polyol B1-2: A mixture of EO and PO, which is an alkylene oxide (b1-2), is subjected to ring-opening addition polymerization with glycerin, which is an initiator (b1-1), using a potassium hydroxide catalyst, and polyoxypropyleneoxy Ethylene polyol (polyol B1-2) was obtained.
Polyol B1-2 has an average number of hydroxyl groups of 3, a hydroxyl value of 45 mg KOH / g, a primary rate of 12%, the content of oxyethylene groups in all oxyalkylene groups is 24% by mass, PO is randomly added.

Polyol B2-1: Polyoxypropylene polyol having a hydroxyl value of 160 mgKOH / g obtained by ring-opening addition polymerization of propylene oxide to glycerin using potassium hydroxide catalyst and purifying with magnesium silicate is used as an initiator (b2- Used as 1). The polyoxypropylene polyol is subjected to ring-opening addition polymerization of propylene oxide, which is an alkylene oxide (b2-2), using a zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst, which is a DMC catalyst, to produce a polyoxypropylene polyol (polyol B2 -1) was obtained. Polyol B2-1 has an average number of hydroxyl groups of 3, a hydroxyl value of 56 mgKOH / g, and an unsaturation degree of 0.005 meq / g.

(Monoall (X))
Monool X1: A mixture of EO and PO which is alkylene oxide (x2) is opened with n-butyl alcohol which is initiator (x1) and zinc hexacyanocobaltate-tert-butyl alcohol complex catalyst which is DMC catalyst. Cycloaddition polymerization was carried out to obtain polyoxypropyleneoxyethylene monool (monool X1).
Monool X1 has an average number of hydroxyl groups of 1, a hydroxyl value of 17 mg KOH / g, a primary conversion rate of 12%, an oxyethylene group content in all oxyalkylene groups of 24% by mass, EO and PO Are randomly added.

(Monoall (Y))
Monool Y1: A mixture of EO and PO, which is an alkylene oxide (y2), is subjected to ring-opening addition polymerization with n-butyl alcohol, which is an initiator (y1), using a potassium hydroxide catalyst. All (monool Y1) was obtained.
Monool Y1 has an average number of hydroxyl groups of 1, a hydroxyl value of 17 mgKOH / g, a primary conversion rate of 12%, a content of oxyethylene groups in all oxyalkylene groups of 24% by mass, EO and PO Are randomly added.

[Polyisocyanate Compound (II)]
Polyisocyanate compound II-1: TDI-80 (mixture of 2,4-TDI / 2,6-TDI = 80/20% by mass), isocyanate group content 48.3% by mass (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) : Coronate T-80).

[Urethane catalyst]
Metal catalyst M1: Tin 2-ethylhexanoate (Air Products and Chemicals, trade name: DABCO T-9).
Amine catalyst N1: Dipropylene glycol solution of triethylenediamine (manufactured by Tosoh Corporation, trade name: TEDA-L33).

[Foaming agent]
Foaming agent: water.

[Silicone-based foam stabilizer]
Foam stabilizer S1: Silicone foam stabilizer, silicon content 18.5% (product name: SZ-580, manufactured by Toray Dow Corning)

Hereinafter, examples and comparative examples will be described.
[Example 1]
A liquid temperature of a mixture of polyol A1 (100 parts), water (1.3 parts), metal catalyst M1 (0.4 parts), and amine catalyst N1 (0.25 parts) (hereinafter referred to as “polyol system”). Adjusted to 21 ± 1 ° C. The liquid temperature of polyisocyanate compound II-1 (isocyanate index 100) was adjusted to 21 ± 1 ° C. Next, polyisocyanate compound II-1 is added to the polyol system and mixed for 5 seconds with a mixer (1,425 revolutions per minute). At room temperature, the top is open. A plastic foam microbial carrier (slab foam) was produced by injecting a plastic sheet into a box. The obtained microorganism carrier was taken out and allowed to stand for 24 hours or more in a room adjusted to a room temperature of 23 ° C. and a humidity of 50%, and various physical properties were measured.

[Examples 2 to 8]
A flexible foam microorganism carrier was produced in the same manner as in Example 1 except that the composition of the raw materials used was changed as shown in Table 1.

[Comparative Examples 1 to 3]
A flexible foam microorganism carrier was produced in the same manner as in Example 1 except that the composition of the raw materials used was changed as shown in Table 1.
However, “EO content” in Table 1 is the content of oxyethylene groups relative to all oxyalkylene groups in polyol (I).

[Evaluation methods]
The measurement and evaluation methods for the flexible foam-made microorganism carrier obtained in Examples 1 to 8 and Comparative Examples 1 to 3 are as follows.
(Foaming stability)
The foaming stability was evaluated based on the following criteria.
○ (Good): Foam is molded and settling is not visible.
Δ (slightly good): The foam is molded and the settling rate is 5% or more, but the foam shape is maintained.
X (defect): The foam collapses (collapses) or the mixed liquid is boiling.
Settling refers to the phenomenon that the molded foam sinks after reaching the maximum height, and the settling rate was calculated from the following formula.
Settling rate (%) = [(AB) / A] × 100
However, in the formula, A means the maximum height (mm) of the foam, and B means the height (mm) when the foam sinks.

(Cell state)
The cell state was evaluated based on the following criteria.
○ (Good): Cell roughening does not occur in the foam, and fine cells can be obtained.
Δ (slightly good): Cell roughness occurs in a part of the foam.
X (defect): Cell roughening occurs in the entire form.

(Foam shrinkage)
Foam shrinkage was evaluated based on the following criteria by visual inspection after taking out the foam from a wooden box and leaving it in a room adjusted to room temperature 23 ° C. and humidity 50% for 24 hours.
○ (Good): No shrinkage occurred in the foam, and the state immediately after foaming was maintained.
Δ (slightly good): Shrinkage occurs in a part of the foam.
X (defect): The entire foam is contracted.

Moreover, it shows below about the measurement of the physical property of the manufactured microorganisms support body (soft foam).
(Core density, core rebound resilience)
The core density and core rebound resilience were measured by a method based on JIS K6400 (1997 edition). What was cut out into a size of 100 mm in length and width and 50 mm in height excluding the skin part from the center part of the foam was used for the measurement.
(25% hardness, breathability, tensile strength, tear strength, elongation, compression residual strain, wet heat compression residual strain)
25% hardness (ILD), tensile strength, tear strength, elongation, compressive residual strain, and wet heat compressive residual strain were measured by methods in accordance with JIS K6400 (1997 edition). The air permeability was measured by a method based on the method B of JIS K6400 (1997 edition).
However, the 25% hardness, air permeability, and core rebound resilience were measured after hand crushing.

Moreover, the carrier performance of the produced microorganism carrier (soft foam) was evaluated by measuring the water absorption and COD _Mn shown below.
(Water absorption)
The amount of water absorption of the produced microorganism carrier was measured by a method based on JIS A9511.
(COD _Mn )
COD _Mn of the produced microorganism carrier was carried out as follows. The microorganism carrier was cut into a cubic shape with a side of 1 cm. 10 g of the cut foam sample was immersed in 200 mL of distilled water for 5 days. About distilled water used for immersion, it measured as oxygen consumption by the potassium permanganate in 100 degreeC by the method based on JISK0102.

As shown in Table 1, the microbial carriers of Examples 1 to 8 using the polyol (A) produced by the DMC catalyst can be produced without using the silicone foam stabilizer, and COD _Mn is low. . Further, it has a large amount of water absorption and has sufficient performance as a microorganism support. In addition, the formability of the foam was good, and the mechanical properties such as tear strength were also good.

On the other hand, in Comparative Example 1 in which the polyol (A) and the silicone-based foam stabilizer were not used, the foaming stability was inferior and foam shrinkage occurred, so that the microorganism carrier could not be produced.
In Comparative Example 2 using a silicone foam stabilizer without using polyol (A), although a flexible foam having good mechanical properties could be produced, COD _Mn was high and sufficient as a support for microorganisms. It did not have performance. This is considered that the silicone type foam stabilizer dissolved in water.
In Comparative Example 3 using a DMC catalyst but using a polyol produced without using ethylene oxide, a flexible foam having good mechanical properties could be produced, but the water absorption amount was low and a microbial support was obtained. Did not have sufficient performance. This is considered to be because the hydrophilicity of the obtained flexible foam was inferior because ethylene oxide was not used.
The entire contents of the description, claims and abstract of Japanese Patent Application No. 2009-058000 filed on March 11, 2009 are incorporated herein by reference as the disclosure of the specification of the present invention. It is.

Claims

A method in which polyol (I) and polyisocyanate compound (II) are reacted in an open system in the presence of a urethanization catalyst and a foaming agent, substantially without using a silicone foam stabilizer,
The urethanization catalyst includes a metal catalyst and an amine catalyst,
The polyol (I) includes the following polyol (A) or a combination of the following polyol (A) and the following monool (X), and the content of oxyethylene groups in all oxyalkylene groups in the polyol (I) is A method for producing a microorganism support made of a flexible polyurethane foam, characterized by comprising 5 to 50% by mass.
Polyol (A): a polyether polyol having a hydroxyl value of 10 to 90 mgKOH / g, obtained by ring-opening addition polymerization of alkylene oxide to an initiator using a double metal cyanide complex catalyst, At least in part, a mixture of ethylene oxide and other alkylene oxides is used.
Monool (X): a polyether monool having a hydroxyl value of 5 to 200 mg KOH / g, obtained by ring-opening addition polymerization of alkylene oxide as an initiator using a double metal cyanide complex catalyst, A mixture of ethylene oxide and another alkylene oxide is used as at least a part of the oxide.
The method for producing a flexible polyurethane foam-made microorganism carrier according to claim 1, wherein the degree of unsaturation of the polyol (A) is 0.05 meq / g or less.
The method for producing a microorganism-supporting body made of flexible polyurethane foam according to claim 1 or 2, wherein the polyol (I) contains a polymer-dispersed polyol.
The method for producing a flexible polyurethane foam-made microorganism carrier according to any one of claims 1 to 3, wherein the primary rate of the polyol (A) is 5 to 50%.
The method for producing a microorganism-supported body made of flexible polyurethane foam according to any one of claims 1 to 4, wherein only water is used as a foaming agent.
The method for producing a microorganism-supported body made of flexible polyurethane foam according to any one of claims 1 to 5, wherein the isocyanate index is 90 to 130.
A microbial carrier made of flexible polyurethane foam having a gas permeability of 40 L / min or more, which is obtained by the method for producing a microbial carrier made of flexible polyurethane foam according to any one of claims 1 to 6.
A flexible polyurethane foam for a microorganism carrier, which is obtained by the production method according to any one of claims 1 to 6 and has an air permeability of 40 L / min or more.
9. A flexible polyurethane foam for a microorganism carrier for purifying water according to claim 8.