JP2018035263A - Composition for preparing porous body with polyurethane resin having high biocompatibility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for preparing a porous body having a homogeneous pore size with a polyurethane resin having high biocompatibility.SOLUTION: A composition has a constant ratio of a water-soluble porogen in a polyurethane resin having such a crosslinked structure that at least one component selected from the group consisting of aliphatic isocyanate and alicyclic isocyanate and at least one component selected from the group consisting of polycarbonate-based polyol and polyether-based polyol are reacted with each other. A polyurethane porous body having a homogeneous pore size thereon can be produced by elution of porogen with particles formed of the composition.SELECTED DRAWING: None

Description

The present invention relates to a polyurethane resin composition containing a water-soluble porogen. More specifically, the present invention relates to a composition capable of obtaining porous particles characterized by having a sharp pore size distribution in a wide particle size range by eluting porogen. Further, it is a non-aromatic polyurethane resin composition that does not produce a toxic aromatic amine even if it is hydrolyzed, and is optimal for the life science field and the food field where high safety is required.

As a method for obtaining a porous polyurethane resin, a method of foaming a so-called polyurethane foam has been widely known. Mainly, aromatic polyols such as MDI (methylenediphenyl diisocyanate) and TDI (toluene diisocyanate) are used in combination with polyester polyols and polyether polyols, and heat insulation (hard polyurethane foam) and cushioning materials (soft polyurethane foam) It is manufactured. In general, the polyurethane foam is used in combination with an auxiliary agent such as a tertiary amine catalyst, a silicone foam stabilizer, or a viscosity reducing agent in order to realize a high expansion ratio and high moldability.
As another method of obtaining a polyurethane resin porous body, a microporous material is prepared by introducing a polyurethane solution using a water-soluble polar solvent such as DMF (NNN-dimethylformamide) into a poor solvent (mainly water). A so-called wet method (phase separation molding method) for molding a simple resin is known as a molding method for artificial leather or foam roll (Patent Document 1).
In addition, a method of forming a nonwoven fabric (web) as a polyurethane resin porous body has been known for a long time (Patent Document 2).

Furthermore, a method of obtaining a polyurethane resin porous body by extruding and shaping a polyurethane solution containing a pore-forming material (porogen) and then immersing it in water and elution-removing the pore-forming material simultaneously with gelation is also known. (Patent Document 3).
In the case of polyurethane foam, it has not been realized yet to completely suppress the bleed-out of the auxiliary agent used at the time of molding, for example, the smell inside the car unique to a new car or the amine odor from a new sofa or bed. This is an experienced phenomenon. Furthermore, aromatic polyurethanes such as MDI and TDI are used for general polyurethane foams, and urethane bonds in the molecule are hydrolyzed by long-term use, resulting in aromatic amines that are toxic to the human body. Known (Patent Document 4).

  In the case of a polyurethane resin porous body molded by a wet method (phase separation molding method), the water-soluble polar solvent (DMF, etc.) dissolved in the resin must be completely removed even after the molded product is thoroughly washed with water. This residual solvent is concerned as an SVHC (substance of high concern) in artificial leather sheets and the like.

Nonwoven fabrics are divided into several molding methods. Among them, nonwoven fabrics molded by the mainstream dry spinning method or wet spinning method contain the problem of residual solvent as described above.
The molded body has a sheet shape, and porous particles cannot be obtained. Further, similarly to the above, it is very difficult to avoid the remaining solvent in the molded body.
In any case of the prior art, since MDI is used in most cases, the generation of aromatic amines during long-term use becomes a safety problem as in the case of foam.

JP-A-4-264144 JP 52-81177 A JP-A-3-47131 Japanese Patent Laid-Open No. 7-224141

An object of the present invention is to provide a composition for obtaining a highly safe polyurethane resin porous body that is optimal for the life science field and food field. Before the water-soluble porogen is eluted, the porous body is a polyurethane resin containing a porogen, and the porogen is eluted to become a polyurethane resin porous body. The polyurethane resin porous body of the present invention is characterized in that the particle size can be arbitrarily set, the particle size distribution is narrow, and the pore size distribution is sharp. Moreover, even if it hydrolyzes, it consists of a non-aromatic polyurethane resin which does not produce an aromatic amine that is toxic to the human body.

As a result of intensive research to achieve these objects, the present inventors have produced a reaction product of a specific polyisocyanate compound (I), a polyol compound (P), a chain length agent (E), and a crosslinking agent (X). The present inventors have found that the series of problems described above can be solved with a composition in which a specific water-soluble porogen (B) is combined in a predetermined blending amount with a polyurethane resin (A) containing a product, and the present invention has been completed.
That is, this invention is shown by the following (1)-(7).
[1] In the solventless polyurethane resin (A), the porogen (B) that is not compatible with the solventless polyurethane resin and dissolves in water is (A) :( B) = 1.0 by mass ratio. : The composition contained in the ratio of 5.0-1.0: 30.0.
[2] The polyurethane resin (A) is
A polyfunctional isocyanate compound (I) containing at least one selected from the group consisting of aliphatic polyisocyanates and alicyclic polyisocyanates;
A high molecular weight polyol compound (P) containing at least one selected from the group consisting of a polycarbonate-based polyol and a polyether-based polyol;
The composition according to [1], further comprising a reaction product of a chain extender (E) and a crosslinking agent (X).
[3] The composition according to [2], wherein the polyfunctional isocyanate compound (I) includes at least one selected from the group consisting of isocyanurates and allophanates of aliphatic polyisocyanates.
[4] The composition according to [2], wherein the polyfunctional isocyanate compound (I) includes at least one selected from the group consisting of an isocyanurate body and an allophanate body of an alicyclic polyisocyanate.
[5] At least one selected from the group consisting of the polycarbonate-based polyol and the polyether-based polyol has an average functional group number of less than 3.0 and an average molecular weight of 400 to 3,000, [3] Or the composition as described in [4].
[6] The composition according to any one of [1] to [5], wherein the porogen (B) has an average particle size of 5 μm or more and less than 900 μm.
[7] The composition according to any one of [1] to [6], wherein the shape is particulate.

According to the polyurethane resin composition of the present invention, a polyurethane resin porous body having a narrow particle size distribution, a sharp pore size distribution, excellent heat resistance and hydrolysis resistance, and high safety to living bodies can be obtained.

It is the figure which showed the particulate polyurethane resin composition. It is the figure which showed the relationship of a porogen (B) and the shape of a porous body (D).

The present invention includes at least
(1) at least one isocyanate compound (I) selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates;
(2) reacting at least one high molecular weight polyol compound (P) selected from the group consisting of polycarbonate-based and polyether-based polyols, a chain extender (E), and a crosslinking agent (X) in an environment where no organic solvent is used. ,
(3) Next, the water-soluble porogen (B) having a sharp particle size distribution is uniformly dispersed in the reaction solution under the condition that the shape of the porogen does not easily collapse,
It is a polyurethane resin composition in which the reaction is completed and solidified.

Moreover, it is possible to obtain a porous body by eluting the porogen from this composition.
According to the inventor's study, because of the urethane resin using the aliphatic or alicyclic isocyanate compound (I), even if the urethane bond is hydrolyzed, there is no occurrence of an aromatic amine that is feared of toxicity. It is characterized by high safety. Furthermore, polycarbonate-based and polyether-based polyols have far superior hydrolysis resistance of the polyol skeleton as compared with other polyester-based polyols and polycaprolactone-based polyols, for example.

In addition, in order to obtain a porous body having a sharp pore size distribution, it is a major premise to use a porogen having a narrow particle size distribution, and further, the porogen is added to the polyurethane resin under the condition that the shape of the porogen is not destroyed during the preparation. It is important to disperse uniformly.
The present invention will be described in detail below.
First, the raw material used for this invention is demonstrated.
The high molecular weight polyol compound (P) used in the present invention preferably contains a polycarbonate-based or polyether-based polyol having an average functional group number of less than 3 and a number average molecular weight of 400 or more and 3000 or less.

The number average molecular weight of the polyol can be calculated from the hydroxyl value according to JIS K1557.
Moreover, the number average molecular weight of a polyol can be measured by converting into polyethylene, polystyrene, etc. using a gel permeation chromatograph (GPC).
Here, the “average functional group number” means a calculated value obtained from the hydroxyl value and the number average molecular weight.
The total amount of the polycarbonate polyol and the polyether polyol preferably accounts for 75% or more of the high molecular weight polyol compound (P) by mass ratio, more preferably 85% or more, and most preferably 95% or more.
The polycarbonate polyol can be obtained by a known method in which a low molecular weight diol and a low molecular weight carbonate are subjected to a condensation reaction.

The low molecular weight diol is a compound having two or more active hydrogen groups and a number average molecular weight of less than 400, and includes ethylene glycol, 1,2- or 1,3-propanediol, 1,2- or 1,3-butane. Diol, 1,4-butanediol (hereinafter abbreviated as 1,4-BD), 1,5-pentanediol, 1,6-hexanediol (hereinafter abbreviated as 1,6-HD), neopentyl glycol, alkane (7-22) Diol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,4-cyclohexanediol, alkane-1,2-diol (C17 -20), 3-methyl-1,5-pentanediol (hereinafter abbreviated as MPD), 2-ethyl -1,3-propanediol, 2-normalpropyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 2-normalbutyl-1,3-propanediol, 2-isobutyl-1,3 -Propanediol, 2-tertiarybutyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2 Normal-propyl-1,3-propanediol, 2-ethyl-2-normalbutyl-1,3-propanediol, 2-ethyl-3-ethyl-1,4-butanediol, 2-methyl-3-ethyl- 1,4-butanediol, 2,3-diethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2,3,4 Triethyl-1,5-pentanediol, dimethylolpropionic acid, dimethylolbutanoic acid, dimer acid diol, alkylene oxide adduct of bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol A, 1,4-dihydroxy-2-butene P-xylylene glycol, bis (2-hydroxyethyl) terephthalate, bis (2-hydroxyethyl) isophthalate, 1,4-bis (2-hydroxyethoxy) benzene, 1,3-bis (2-hydroxyethoxy) Benzene, resorcin, hydroquinone, 2,2'-bis (4-hydroxycyclohexyl) propane, 2,6-dimethyl-1-octene-3,8-diol, 3,9-bis (1,1-dimethyl-2- Hydroxyethyl) -2,4,8,10-tetraoxaspir [5,5] undecane, bisphenol F, include dihydric alcohols such as bisphenol A, it can be used alone or in combination.
Examples of the low molecular weight carbonate include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate (hereinafter abbreviated as DEC), diaryl carbonates such as diphenyl carbonate, and alkylene carbonates such as ethylene carbonate and propylene carbonate.

The preferred number average molecular weight of the polycarbonate polyol in the present invention is 400 or more and 3,000 or less, more preferably 400 or more and 2,000 or less, and most preferably 400 or more and 1,000 or less. When the number average molecular weight is increased, the viscosity of the liquid is increased, workability in preparing the polyurethane resin (A) is decreased, the mixing property with the polyfunctional isocyanate compound (I) is deteriorated, and the reaction is not uniform. The evil of is easy to be born.
Polyether polyol is generally a low molecular weight active hydrogen compound used as an initiator and ethylene oxide or alkylene oxide having 3 or more carbon atoms added alone or in combination using a Lewis acid catalyst or the like. is there. Examples of the “alkylene having 3 or more carbon atoms” include 1,2-propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, tetrahydrofuran (1,4-butylene oxide) and the like. In the present invention, ethylene oxide, propylene oxide, or tetrahydrofuran is preferable.

  As the low molecular weight active hydrogen compound serving as an initiator for the polyether polyol, in addition to the low molecular weight diol, a low molecular weight polyol having a number average molecular weight of less than 400 having three or more active hydrogen groups is preferable. Glycerin, trimethylolpropane Polyhydric alcohols having four or more hydroxyl groups such as trihydric alcohols (hereinafter abbreviated as TMP), tetramethylolmethane, pentaerythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, D-mannitol, Low molecular weight polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, tolylenediamine, diethyltolylenediamine, diaminodiphenylmethane, isophoronediamine, monoethanolamine, diethanolamine, triethanol Addition of alkylene oxide to low molecular weight aminoalcohols such as amine, monopropanolamine, dipropanolamine, tripropanolamine, N-methyl-diethanolamine, N-phenyl-dipropanolamine, and the aforementioned low molecular weight polyamines and low molecular weight aminoalcohols The compound etc. which were made to be mentioned are mentioned, These can be used individually or in combination of 2 or more types.

  The number of functional groups in the initiator of the polyether polyol is preferably less than 4.0, and more preferably less than 3.0. When the number of functional groups of the initiator exceeds the upper limit, the flexibility and toughness of the obtained polyurethane resin (A) are easily lost.

  In the present invention, a polyester polyol can be used in combination with a part of the high molecular weight polyol compound (P) as long as the performance is not impaired. Examples of the polyester polyol include polycondensates obtained by reacting a low molecular weight active hydrogen compound and a polybasic acid under known conditions.

Examples of the low molecular weight active hydrogen compound include the low molecular weight diols and low molecular weight polyols described above, and these can be used alone or in combination of two or more.
As polybasic acids, oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelain Acid, sebacic acid, other aliphatic dicarboxylic acids (carbon number 11 to 13), suberic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, Carboxylic acids such as eicosane diacid, methylhexane diacid, citraconic acid, hydrogenated dimer acid, maleic acid, fumaric acid, itaconic acid, orthophthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, dimer acid, het acid, and Acid anhydrides derived from these carboxylic acids, acid halides, ricinoleic acid, 12-hydro Etc. Shisutearin acid, and the like.
Specific examples of polycondensates of low molecular weight polyols and polybasic acids include poly (ethylene butylene adipate) polyol, poly (ethylene adipate) polyol, poly (ethylene propylene adipate) polyol, poly (propylene adipate) polyol, poly (Butylenehexamethylene adipate) polyol, poly (butylene adipate) polyol, poly (hexamethylene adipate) polyol and the like.

Further, as the polyester polyol, polycaprolactone polyol, polyvalerolactone polyol obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using the low molecular weight polyol as an initiator, and further to them Examples thereof include lactone polyols copolymerized with the dihydric alcohol.
The chain extender (E) used in the present invention is a compound selected from the aforementioned low molecular weight diols, and can be used alone or in combination of two or more.

  In the present invention, the molar ratio with respect to the high molecular weight polyol (P) is desirably a ratio of 0.01 or more and 0.20 or less. When it is less than 0.01, aggregation of urethane bonds, so-called hard segment domains, is insufficient, and the strength and heat resistance of the polyurethane resin (A) are lowered. On the other hand, when the upper limit is exceeded, the hard segment domain becomes excessive, and the flexibility and toughness of the resulting polyurethane resin (A) are likely to be lost.

The crosslinking agent (X) used in the present invention is selected from the above low molecular weight polyol (trivalent or higher active hydrogen compound) alone or in combination of two or more, and has a molecular weight per functional group of 30 or more and 450 or less. Compounds are preferred, with 40 to 400 being even more preferred. Moreover, the preferable active hydrogen group of a crosslinking agent is a hydroxyl group and an amino group.
Particularly preferable examples of the crosslinking agent (X) in the present invention include TMP.
In the present invention, the molar ratio with respect to the high molecular weight polyol (P) is desirably a ratio of 0.01 or more and 0.20 or less. If it is less than 0.01, the effect due to the use of the cross-linking agent is not seen, and if it exceeds 0.20, the hard segment domain is excessive, and the flexibility and toughness of the resulting polyurethane resin (A) are likely to be lost. .

In the present invention, it is desirable to use a urethanization catalyst in consideration of advantages such as shortening the reaction time of the polyurethane resin (A) and completion of the reaction.
As the catalyst, any of the commonly used urethanization catalysts can be used. However, so-called amine-based catalysts such as tertiary amines and quaternary ammonium salts are harmful due to residual catalysts in the resin (adverse effects on living organisms and odors). ) Is not preferable. Preferred are metal catalysts, bismuth, lead, tin, iron, titanium, zirconium, antimony, uranium, cadmium, cobalt, thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese, calcium And organic compounds such as inorganic compounds and the like.
Among these, bismuth-based catalysts and zirconium-based catalysts are most preferable.

The catalyst may be used either alone or in the form of a mixture of two or more.
The amount of catalyst used is determined by the properties of other raw materials, reaction conditions, desired reaction time, and the like, and is not particularly limited, but is generally about 0. 0 of the total mass of the polyurethane resin (A). 001-0.05 mass% is preferable, and it is further more preferable to use in the range of 0.002-0.02 mass%.

  Furthermore, as necessary, lubricants, flame retardants, plasticizers, hydrolysis inhibitors, antioxidants, UV absorbers, colorants, various fillers, internal mold release agents, antiblocking agents, reinforcing fibers, etc. Although a processing aid can be added and used, it is desirable to suppress the amount used as much as possible in consideration of bleeding out from the polyurethane resin (A) after molding. Of these auxiliaries, those that do not have an active hydrogen group capable of reacting with isocyanate can be used by mixing in advance with the polyfunctional isocyanate compound (I).

As the polyfunctional isocyanate compound (I) used in the present invention, at least one selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates is used, and can include respective isocyanurates or allophanates.
The polyfunctional isocyanate compound (I) used in the present invention includes hexamethylene diisocyanate (hereinafter referred to as HDI), tetramethylene diisocyanate, 2-methyl-pentane-1,5-diisocyanate, 3-methyl-pentane-1,5- Aliphatic diisocyanates such as diisocyanate, decamethylene diisocyanate, lysine diisocyanate, trioxyethylene diisocyanate; aromatic aliphatic diisocyanates such as xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, tetramethylxylylene diisocyanate; isophorone diisocyanate ( (Hereinafter referred to as IPDI), norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, methylene dicyclo Xyl diisocyanate (also known as hydrogenated diphenylmethane diisocyanate, hereinafter referred to as H12-MDI), cycloaliphatic diisocyanates such as hydrogenated tetramethylxylene diisocyanate, and trimers, allophanates, biurets, dimers, dimers and trimers of the above isocyanates The adduct body obtained by reaction of a body, a carbodiimide body, a uretonimine body, a bifunctional or higher polyol and the like with the isocyanate.

These organic isocyanates may be used alone or in the form of a mixture of two or more. In the present invention, an isocyanate selected from aliphatic, araliphatic, and alicyclic is preferable in consideration of the biosafety of the resulting porous body, and particularly HDI, IPDI, or H12- from the viewpoint of heat resistance and the like. MDI is preferred. These organic diisocyanates have a high vapor pressure at room temperature, and in view of the working environment when preparing urethane resins, those obtained by distilling off unreacted diisocyanates after adducting, trimerizing, allophanating, biureting, etc. Further preferred. These reactions may be used alone or in combination.
As a preferable form of the polyfunctional isocyanate compound (I) of the present invention, the organic isocyanate is adducted with the low molecular weight diol (divalent alcohol), the organic isocyanate is trimerized, or the organic isocyanate with a monovalent or higher alcohol. Is allophanated, and then the unreacted isocyanate monomer component is distilled off. These reactions may be used alone or in combination.
The most preferred form of the polyfunctional isocyanate compound (I) of the present invention is that after adducting an organic isocyanate with the low molecular weight diol (divalent alcohol), trimerizing it, and distilling off unreacted isocyanate monomer components. The polyol is partially reacted to be prepolymerized.

As the polyol used for prepolymerization, the polyether polyol is preferable. Of these, polyethylene glycol (hereinafter abbreviated as PEG) is preferred.
The number average molecular weight of PEG is preferably 200 to 1,500, more preferably 300 to 1,000, and most preferably 400 to 800.
It is preferable to mix | blend the quantity of the polyether polyol introduce | transduced by prepolymerization so that it may become the range of 1-20% with respect to the polyurethane resin (A) to prepare. Preferably it is 1 to 15%, more preferably 1 to 10%.
In the case of a prepolymer using PEG, when the introduction amount is below the lower limit, the polyurethane resin (A) becomes white turbid under high temperature and high humidity (for example, during the elution operation of porogen) (reversible whitening, and becomes transparent when dried). There is a fear). On the other hand, when the introduction amount exceeds the upper limit, the viscosity of the polyfunctional isocyanate compound (I) increases, the workability when preparing the polyurethane resin (A) decreases, or the miscibility with the high molecular weight polyol compound (P). Detrimental effects such as poor reaction and non-uniform reaction are likely to occur.

  The porogen (B) that can be used in the present invention is water-soluble, polyvinyl alcohol (saponification degree: 70% or more and less than 98%), polyethylene glycol having a terminal alkoxylation, water-soluble cellulose derivative (methyl cellulose, carboxymethyl cellulose, Carboxymethylcellulose sodium salt, hydroxypropylmethylcellulose, etc.), polyacrylamide, polymethacrylamide, sodium chloride, potassium chloride, and polysaccharides, or a combination of two or more. Among these, water-soluble cellulose derivatives, sodium chloride, potassium chloride, and polysaccharides are preferable. Particularly preferred are sodium chloride, potassium chloride and polysaccharides. Most preferred are sodium chloride and potassium chloride.

  The proportion of the porogen (B) contained in the polyurethane resin composition is suitably about 500 to 3,000%, more preferably about 700 to 2,000% with respect to the polyurethane resin (A).

That is, when the amount of the porogen is less than 500%, the polyurethane resin (A) and the porogen (B) do not adhere to each other at the time of granulation, and not only particles are hardly formed, but also the surface of the composition tends to be non-uniform. Defects such as a decrease in the yield of the composition are likely to occur. On the other hand, when it exceeds 2,000%, there is a problem that economics at the time of producing the composition is lowered.
The shape of the porogen (B) may be either particulate or fibrous, but its size (or diameter) is an important point. If the sizes are not uniform, the pores of the porous body after the porogen is eluted from the polyurethane resin composition tend to be uneven.

  When the porogen (B) contained in the polyurethane resin composition is in the form of particles, the average particle size is preferably 5 μm or more and less than 900 μm. More preferably, the average particle size is 7 μm to 500 μm, and most preferably the average particle size is 10 μm to 400 μm.

When the porogen (B) contained in the polyurethane resin composition is particulate, it is desirable that ε {(D90−D10) ÷ D50}, which is an index of the particle size distribution of the porogen (B), is less than 2.00. This particle size distribution can be measured by Microtrac HRA (manufactured by Nikkiso Co., Ltd., laser diffraction particle size distribution meter, measured by wet circulation using a poor solvent for porogen).
When the polyurethane resin composition is granulated by mixing the reaction solution of the polyurethane resin (A) and the porogen (B), it is necessary to consider that the porogen (B) is not crushed as much as possible. Specifically, the agitation blade of the agitation granulator is selected as a type having a small shearing force, and the agitation speed is suppressed as much as possible, the agitation time is shortened, and the polyurethane reaction liquid and porogen (in accordance with the vessel capacity) It is also necessary to adjust the charge amount of B).

The polyurethane resin composition thus granulated can complete the urethanization reaction by curing for 2 to 5 days in an environment of 60 to 120 ° C.
The porous body can be obtained by completely eluting the porogen (B) contained in the polyurethane resin composition in which the reaction has been completed in a water bath or a hot water bath and then drying. The porous body preferably has an average particle size = 400 μm or more and 3.0 mm or less, an average pore size = 5 μm or more and 900 μm or less, and a pore volume of 2.0 cm 3 / g or more. More preferably, the average particle diameter is 450 μm or more and 2.5 mm or less, the average pore diameter is 7 μm or more and 500 μm or less, and the pore volume is 3.0 cm 3 / g or more. Most preferably, the average particle size is 10 μm to 400 μm.

Before elution of the porogen (B) from the polyurethane resin composition in which the reaction has been completed, it is preferable to classify as necessary and adjust it to a predetermined particle size range. This is because the apparent specific gravity of the porous material after elution of the porogen is reduced, and classification using a sieve becomes difficult.
Moreover, when using a porous body in water, it is also possible to store the particle | grains after porogen (B) elution in water, without drying. This is also effective in suppressing the floating of the porous body due to the bubbles remaining in the pores when the once dried porous body is immersed again in water.

  When applying a porous body to a use requiring biocompatibility, it is desirable to sterilize in advance. As a sterilization method, a known method can be used, and examples thereof include sterilization by immersing in ethanol having a concentration of 30% by volume or more, sterilization in an autoclave at 120 ° C., sterilization by gamma irradiation, and the like.

The particulate polyurethane resin composition and the production method thereof according to the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, “%” means “% by mass”.
<Preparation method of particulate polyurethane resin composition>
(1) A high molecular weight polyol (P), a chain extender (E), a crosslinking agent (X), and auxiliary agents such as a catalyst as necessary are mixed in advance to adjust the temperature.
(2) The porogen (B) is sufficiently pre-dried to remove moisture to 0.1% or less.
(3) Charge porogen into a vertical mixer with impeller blades and purge with nitrogen.
(4) In another mixer, the polyfunctional isocyanate compound (I) and the polyol mix preliminarily mixed in (1) are mixed uniformly.
(5) The liquid mixture sufficiently degassed by a decompression operation or the like is dropped into the mixer simultaneously with the start of stirring of the mixer charged with the porogen.
(6) The rotation speed of the mixer is the upper limit of rotation speed at which the porogen particles are not crushed, and the mixing time is as short as possible.
(7) Particles in which the porogen (B) adheres to the polyurethane resin (A) in a clothing shape are obtained.
(8) The obtained particles are put in a sealed container and cured in an atmosphere at 90 ° C. for 2 days.
(9) A particulate polyurethane resin composition is obtained by classifying with an arbitrary sieve.

For mixing the above-mentioned polyol mix and polyfunctional isocyanate compound (I), a low-pressure injector equipped with a known mechanical stirring device or a high-pressure injector utilizing a high-pressure collision mixing system can be used.
The R value ([total number of moles of isocyanate groups of the polyfunctional isocyanate compound] / [total number of moles of hydrogen groups in the polyol mix]) at this time is preferably 0.70 or more and less than 1.30. More preferably, it is 0.70 or more and less than 1.25, More preferably, it is the range of 0.70 or more and less than 1.20.
Under a good working environment, the particulate polyurethane resin composition thus obtained is a spherical particle having a porogen on its outer surface, as shown in FIG.

<Synthesis Example 1>
In a four-necked flask with a capacity of 1,000 ml equipped with a stirrer, a thermometer, and a cooling tube, 995 g of HDI (manufactured by Tosoh Corporation, NCO content: 49.9% by mass), 1.0 g of phenol, 1,3- 5 g of butanediol (manufactured by Daicel Chemical Industries, Ltd., hereinafter referred to as 1,3-BG) was charged, and urethanization reaction was performed at 80 ° C. for 2 hours under a nitrogen stream. Thereafter, the reaction solution was kept at 60 ° C., 0.5 g of a 20% diethylene glycol (manufactured by Adeka) solution of potassium octylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and an isocyanuration reaction was performed for 2 hours. After the NCO content reached 39.5% by mass, 0.3 g of 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., hereinafter referred to as JP-508) was added to carry out a termination reaction. The reaction solution was thin-film distilled at 130 ° C. × 0.04 kPa to remove unreacted HDI, and purified polyisocyanate (hereinafter referred to as PI) 1 was obtained in a yield of 37.1% by mass. PI-1 is a transparent viscous liquid, the NCO content is 21.8% by mass, the GPC number average molecular weight is 680, the average number of functional groups based on the formula (1) is 3.5, and the EO content (PEG content) is The content of 0% by mass and free HDI was 0.2% by mass. The average number of NCO functional groups was calculated from the formula (1).

Average number of NCO functional groups = NCO content × GPC number average molecular weight / (100 × 42) (1)
<GPC: Measurement of number average molecular weight>
Measuring instrument: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSKgel (manufactured by Tosoh Corporation)
・ G3000H-XL
・ G2500H-XL
・ G2000H-XL
・ G1000H-XL
・ Carrier: Tetrahydrofuran (THF)
-Detector: RI (refractive index) detector-Sample: 0.5% THF solution-Temperature: 40 ° C
・ Flow rate: 1.000 ml / min
-Calibration curve: Standard polystyrene (manufactured by Tosoh Corporation)
F-80 (molecular weight: 7.06 × 105, molecular weight distribution: 1.05)
F-20 (molecular weight: 1.90 × 105, molecular weight distribution: 1.05)
F-10 (molecular weight: 9.64 × 104, molecular weight distribution: 1.01)
F-2 (molecular weight: 1.81 × 104, molecular weight distribution: 1.01)
F-1 (molecular weight: 1.02 × 104, molecular weight distribution: 1.02)
A-5000 (molecular weight: 5.97 × 103, molecular weight distribution: 1.02)
A-2500 (molecular weight: 2.63 × 103, molecular weight distribution: 1.05)
A-500 (molecular weight: 5.0 × 102, molecular weight distribution: 1.14)
<Synthesis Example 2>
A reaction vessel similar to Synthesis Example 1 was charged with 850 g of HDI, 150 g of PEG-400 (Sanyo Chemical Industries, polyoxyethylene glycol, average number of EO units 8, terminal OH functional group number 2, number average molecular weight 410), nitrogen The urethanization reaction was performed at 80 ° C. for 2 hours under an air stream. Thereafter, 0.10 g of zirconyl octylate (manufactured by Daiichi Rare Element Chemical Industry Co., Ltd., zirconium octylate) was added, and an allophanatization reaction was performed at 110 ° C. for 2 hours. After the NCO content reached 36.1% by mass, 0.11 g of JP-508 was added to stop the reaction, and the reaction solution was cooled to room temperature. This reaction solution was subjected to thin-film distillation at 130 ° C. × 0.04 kPa to remove unreacted HDI, and purified PI-2 was obtained in a yield of 38.4% by mass. PI-2 is a transparent viscous liquid having an NCO content of 14.0% by mass, a GPC number average molecular weight of 1450, an average NCO functional group number based on the formula (1) of 4.8, an EO content (PEG content) Amount) was 43.1% by weight. The free HDI content was 0.2% by weight.

<Synthesis Example 3>
A reaction vessel similar to Synthesis Example 1 was charged with 995 g of IPDI (Evonik, NCO content: 37.8% by mass), 1.0 g of phenol, and 5 g of 1,3-BG, and at 80 ° C. under a nitrogen stream. The urethanization reaction was carried out for 2 hours. Thereafter, the reaction solution was kept at 60 ° C., 0.5 g of 20% diethylene glycol solution of potassium octylate was added, and isocyanuration reaction was performed for 2 hours. After the NCO content reached 36.1% by mass, 0.3 g of JP-508 was added and a termination reaction was performed. This reaction solution was thin-film distilled at 130 ° C. × 0.04 kPa to remove a part of unreacted IPDI, and purified PI-3 was obtained in a yield of 38.4% by mass. PI-3 is a transparent viscous liquid, the NCO content is 20.0% by mass, the GPC number average molecular weight is 700, the average number of functional groups based on the formula (1) is 3.3, and the EO content (PEG content) is The content of 0% by mass and free IPDI was 15.0% by mass.
When free IPDI was distilled off to 0.2% by mass by thin film distillation, a solid having an NCO content = 17.3% by mass and a melting point = 108 ° C. was obtained.

<Synthesis Example 4>
In a reaction vessel similar to Synthesis Example 1, 960 g of 4,4′-dicyclohexylmethane diisocyanate (manufactured by Evonik, NCO content: 32.0 mass%, hereinafter referred to as H12-MDI), ethyl alcohol (Wako Pure Chemical Industries, Ltd.) Manufactured, purity = 99.5%) was charged, and urethanization reaction was carried out at 80 ° C. for 2 hours under a nitrogen stream. Thereafter, 0.10 g of zirconyl octylate was added, and an allophanatization reaction was performed at 110 ° C. for 2 hours. After the NCO content reached 20.4% by mass, 0.11 g of JP-508 was added to stop the reaction, and the reaction solution was cooled to room temperature. This reaction solution was subjected to thin-film distillation at 130 ° C. × 0.04 kPa to remove unreacted H12-MDI, and purified PI-4 was obtained in a yield of 37.5% by mass. PI-4 was a transparent viscous liquid, the NCO content was 9.6% by mass, the GPC number average molecular weight was 875, and the average NCO functional group number based on the formula (1) was 2.0. The EO content (PEG content) is 0% by mass. The free H12-MDI content was 0.2% by weight.

<Synthesis Example 5>
In a reaction vessel similar to Synthesis Example 1, 900 g of PI-1 and 100 g of PEG-600 (manufactured by Sanyo Kasei Kogyo Co., Ltd., polyoxyethylene glycol, number of terminal OH functional groups, number average molecular weight 600) were charged under nitrogen flow, 80 The urethanization reaction was performed at 5 ° C. for 5 hours to obtain PI-5. PI-5 was a transparent viscous liquid, the NCO content was 19.3% by mass, the GPC number average molecular weight was 795, and the average NCO functional group number based on the formula (1) was 3.6. The EO content (PEG content) is 10% by mass.

<Synthesis Example 6>
A reaction vessel similar to Synthesis Example 1 was charged with 850 g of PI-3 and 150 g of PEG-1000 (manufactured by Sanyo Chemical Industries, polyoxyethylene glycol, terminal OH functional group number 2, number average molecular weight 1000) under a nitrogen stream, 80 The urethanization reaction was performed at 5 ° C. for 5 hours to obtain PI-6. PI-6 was a transparent viscous liquid, had an NCO content of 17.5% by mass, a GPC number average molecular weight of 815, and an average NCO functional group number of 3.4. The EO content (PEG content) is 15% by mass.

<Synthesis Example 7>
In a reaction vessel similar to Synthesis Example 1, 970 g of PI-4 and 30 g of Leocon GE1000 (Lion Corporation polyoxyethylene glyceryl ether, terminal OH functional group number 3, number average molecular weight 1000) were charged at 80 ° C. under a nitrogen stream. Urethane reaction was performed for 5 hours to obtain PI-7. PI-7 was a transparent viscous liquid, had an NCO content of 8.9% by mass, a GPC number average molecular weight of 955, and an average NCO functional group number of 2.0. The EO content (PEG content) is 3% by mass.

<Synthesis Example 8>
In a reaction vessel similar to Synthesis Example 1, 500 g of 4,4′-diphenylmethane diisocyanate (Millionate MT manufactured by Tosoh Corporation, NCO content: 33.6% by mass, hereinafter referred to as MT) and 150 g of PEG-1000 were charged, and a nitrogen stream The urethanization reaction was carried out at 80 ° C. for 5 hours. Thereafter, 350 g of polyphenylene polymethylene polyisocyanate (Millionate MR-200 manufactured by Tosoh Corporation, NCO content: 30.8% by mass, hereinafter referred to as MR-200) was added and mixed uniformly to obtain PI-8. PI-8 was a brownish-brown transparent liquid having an NCO content of 26.3% by mass, a GPC number average molecular weight of 355, and an average NCO functional group number of 2.2. The EO content (PEG content) is 15% by mass.

<Preparation Examples 1 to 11: Preparation of porogen (B)>
Porogen (B) was prepared according to the formulation shown in Table 3.
For NaCl, Nakuru UM05 (manufactured by Naikai Shigyo Co., Ltd., average particle size = 5 μm), Osiomicron T-0 (manufactured by Ako Kasei Co., Ltd., mean particle size = 12 μm), Nakuru UM20 (manufactured by Naikai Shigyo Co., Ltd., average particle size) = 20 μm), Nakuru UM (manufactured by Naikai salt industry, average particle size = 45 μm), Nakuru Four 5 (manufactured by Naikai salt industry, average particle size = 135 μm), Nakuru for B (manufactured by Naikai salt industry, average particle size = 700 μm) ) Were appropriately classified with a predetermined sieve and before use, they were dried for 48 hours or more with a hot air dryer at 90 ° C. and used for granulation.
A special grade reagent (manufactured by Wako Pure Chemical Industries, average particle size = 200 μm) was used for KCl, and similarly classified and dried and used for granulation.
For sucrose, Frost Sugar (Nisshin Sugar Co., average particle size = 1.5 mm) and Frost Sugar FS-2 (Nisshin Sugar Co., average particle size = 41 μm) are used, and similarly classified and dried. Used for granulation.

Hydroxypropylmethylcellulose (Dow Chemical Co., Methocel HPMC, average particle size = 85 μm) was similarly classified and dried and used for granulation.
Table 3 shows the volume distribution D10 (particle diameter at the position of 10% by mass from the smallest particle diameter side) and D50 (particle diameter at the position of 50% by mass) as measured by the laser diffraction particle size distribution diameter. , Average particle diameter) and D90 (particle diameter at a position of 90% by mass counted from the smallest particle diameter side).
Furthermore, the ε value was listed as a guide for the particle size range. In addition, it means that the width | variety of a particle size distribution is so narrow that the value of (epsilon) is small.
ε = (D90−D10) ÷ D50 (2)

<Synthesis Examples 9 to 29: Preparation of particulate polyurethane resin composition>
In accordance with the formulations shown in Tables 4 to 6, the high molecular weight polyol (P), the chain extender (E), the cross-linking agent (X), and the urethanization catalyst are first mixed at 80 ° C. for 1 hour, and a mixture of polyol components (hereinafter referred to as polyol) A mix).
Explanation of symbols in the table.
[E] / [P]: (ratio of the number of moles of active hydrogen groups [E] of the chain extender (E) to the number of moles of active hydrogen groups [P] of the high molecular weight polyol (P))
[X] / [P]: (ratio of the number of moles of active hydrogen groups [X] of the crosslinking agent (X) to the number of moles of active hydrogen groups [P] of the high molecular weight polyol (P))
Average molecular weight of polyol mix: Calculated value based on analytical value of each polyol component Total number of functional groups of polyol mix: Calculated value based on analytical value of each polyol component Next, polyol mix and polyfunctional isocyanate compound (I) was adjusted to 60 ° C., respectively, and mixed at a blending ratio described in Tables 4 to 6 to prepare a polyurethane reaction solution.
For the mixing, a rotation and revolution type mixer (manufactured by Sinky, ARE-310 type, stirring conditions: 2000 rpm × 120 seconds, defoaming conditions: 2200 rpm × 60 seconds) was used.
Formulation of polyurethane resin (A) reaction solution

Explanation of symbols in the table PCD-500: obtained by reacting a mixture of 3-methyl-1,5-pentanediol and 1,6-hexamethylenediol (molar ratio = 9: 1) with diethyl carbonate, Polycarbonate polyol (high molecular weight polyol, manufactured by Tosoh, molecular weight = 500, functional group number = 2.0)
1,4-BD: 1,4-butanediol (chain extender, manufactured by Mitsubishi Chemical Corporation, molecular weight = 90.1, number of functional groups = 2.0)
TMP: trimethylolpropane (crosslinking agent, manufactured by Mitsubishi Gas Chemical Company, molecular weight = 134.2, number of functional groups = 3.0)
PCD-1000: Polycarbonate polyol (high molecular weight) obtained by reacting a mixture of 3-methyl-1,5-pentanediol and 1,6-hexamethylenediol (molar ratio = 5: 5) and diethyl carbonate Polyol, manufactured by Tosoh, molecular weight = 1000, number of functional groups = 2.0)
PPG-2000: polyether polyol obtained by addition reaction of propylene oxide with 1,2-dipropylene glycol by ring-opening polymerization (high molecular weight polyol, Sanyo Chemical Industries, molecular weight = 2000, functional group number = 2.0)
Bismuth-based catalyst: Neostan U-600 (manufactured by Nitto Kasei Co., Ltd., bismuth tris (2-ethylhexanoate, Bi content: 18.0 to 19.0%)
Molecular weight of polyol component: Average value of molecular weight per mole of each polyol component Number of functional groups of polyol: Average value of number of functional groups per mole of each polyol component EO content: Mass% of polyethylene glycol units in the system
Next, porogen (B) was charged in advance in a tank of a high speed mixer (manufactured by Nippon Coke, FM-10 type), and sufficiently purged with nitrogen gas to prepare for granulation. Then, simultaneously with the start of stirring (1200 rpm), the polyurethane reaction liquid was added dropwise based on the formulations described in Tables 7-10. After 40 seconds from the start of stirring, stirring was stopped and the granulated particles were collected.
The recovered granulated product was put in a stainless steel container, covered, and cured in a hot air dryer at 90 ° C. Thereafter, when the peak near 2270 cm −1 in the ATR-FT-IR spectrum (manufactured by JASCO Corporation) disappeared, it was determined that the urethanization reaction was completed, and the resulting particles were sieved with a predetermined sieve. Classification (example: 1.4 mm sieve, 1.0 mm sieve) was performed to obtain a polyurethane resin composition. Properties of Composition C are summarized in Tables 7-10.

When the porogen (B) is NaCl or KCl, the obtained polyurethane resin composition is put in a crucible and baked at 500 ° C. for 24 hours to ash the polyurethane resin, and the particle size distribution of the recovered porogen (B) is measured. Thus, the present invention was confirmed to have properties within the scope of the right of the present invention.
In addition, about the polyurethane resin composition collect | recovered as a granulated product, when the porogen (B) used is a water-soluble cellulose derivative, a porogen (B) is completely eluted by fully washing with 25 degreeC ion-exchange water. It was possible to obtain a porous body of the polyurethane resin (A) by drying it.
When the porogen (B) used is other than the water-soluble cellulose derivative, the porogen (B) can be completely eluted by washing thoroughly with warm water at 90 ° C., and the polyurethane resin (A ) Was obtained. Properties of the porous body are described in Tables 7 to 10, and the relationship between the obtained porogen (B) and the shape of the porous body (D) is shown in FIG.
Properties of composition (C) and porous body (D)

Explanation of Symbols in Table HPMC: Hydroxypropylmethylcellulose average pore size: The average value was determined by observation with an optical microscope.
Pore volume: Measured with a mercury porosimeter.
Surface brittleness of the porous body: Judgment was made based on the presence or absence of a resin falling off the surface when the dried porous body was rubbed with a finger. ◎: None, ○: Almost none, Δ: Slightly, ×: Yes.
Strength of porous body: Judged by the presence or absence of particle breakage when the porous body was immersed in water and stirred with a spoon. ◎: None, ○: Almost none, Δ: Slightly, ×: Yes.
Heat resistance of porous body: Judged from the state of particles after the porous body was immersed in water and sterilized by autoclaving at 121 ° C. for 3 hours. A: No change, B: Almost no change, B: Slight change, X: Change.

  Elution of aromatic amine from porous body: Judgment was made based on the presence or absence of aromatic amine eluted from porous body (D) immersed in high-temperature water. Specifically, 1 g of the porous body (D) was added to 100 ml of ion-exchanged water, and treated with an autoclave at 121 ° C. for 8 hours. Thereafter, the sample cooled to room temperature was placed in a 1000 ml eggplant-shaped flask, and further 70 ml of methanol was added and heated at 70 ° C. for 30 minutes. After completion of the heating, the mixture was cooled to room temperature within 2 minutes, and the aromatic amine was extracted into the organic layer with 50 ml of tert-butyl methyl ether. The aromatic amine contained in this extract was qualitatively determined, and then the amount of the aromatic amine was quantified by GC-MS (gas chromatograph-mass spectrometer) and HPLC (high performance liquid chromatograph).

<Examples 1 to 24>
As described in Tables 7 to 8, the porous body obtained by the present invention is characterized in that the pore size distribution is sharp in a wide particle size range. In addition, it was confirmed that it is a non-aromatic polyurethane resin composition that does not produce toxic aromatic amines even if it is hydrolyzed, and is optimal for the life science field and food field where high safety is required. .

<Comparative Examples 1-9>
As described in Table 9, the porous bodies obtained in Comparative Examples 1 to 9 were lower than the porous bodies obtained in the Examples in terms of surface brittleness, strength, and heat resistance.
In Comparative Examples 1 and 2, unlike porogen (B) used in Examples 1 to 6, ε {(D90−D10) ÷ D50} which is an index of the particle size distribution of porogen (B) is a value of 2.00. Since it was in the vicinity, the particle size distribution of the porogen recovered from the composition (C) was 2.00 or more.
In Comparative Example 3, since sucrose was used for the porogen (B), the pore volume of the porous body (D) was larger than that of the porous body obtained by the present invention.

In Comparative Examples 4 and 5, when the chain extender [E] / high molecular weight polyol compound [P] (molar ratio) is out of the range of 0.10 or more and 0.50 or less, the surface brittleness of the porous body (D) From the viewpoints of strength and heat resistance, the results were lower than the porous bodies obtained in the examples.
In Comparative Example 6, since the crosslinking agent [X] / high molecular weight polyol compound [P] (molar ratio) is 3.5 or more, it is obtained in Examples from the surface brittleness of the porous body (D). The result was lower than that of the porous body.

In Comparative Examples 7 and 8, the ratio of the number of moles of NCO groups in the polyfunctional isocyanate compound (I) used in the examples to the number of moles of active hydrogen groups in the polyol component was calculated as [NCO group] / [active hydrogen group]. By deviating from the range of 0.70 or more and less than 1.30, the results were lower than the porous bodies obtained in the examples in terms of surface brittleness, strength, and heat resistance.
In Comparative Example 8, the aromatic amine from the porous body (D) was eluted by using an aromatic amine different from the examples.

Claims (7)

  In the solventless polyurethane resin (A), the porogen (B) that is not compatible with the solventless polyurethane resin and dissolves in water is (A) :( B) = 1.0: 5. The composition contained in the ratio of 0-1.0: 30.0. The polyurethane resin (A) is
A polyfunctional isocyanate compound (I) containing at least one selected from the group consisting of aliphatic polyisocyanates and alicyclic polyisocyanates;
A high molecular weight polyol compound (P) containing at least one selected from the group consisting of a polycarbonate-based polyol and a polyether-based polyol;
The composition according to claim 1, further comprising a reaction product of a chain extender (E) and a crosslinking agent (X).   The composition according to claim 2, wherein the polyfunctional isocyanate compound (I) includes at least one selected from the group consisting of isocyanurates and allophanates of aliphatic polyisocyanates.   The composition according to claim 2, wherein the polyfunctional isocyanate compound (I) includes at least one selected from the group consisting of an isocyanurate body and an allophanate body of an alicyclic polyisocyanate.   At least one selected from the group consisting of the polycarbonate polyol and the polyether polyol has an average functional group number of less than 3.0 and an average molecular weight of 400 or more and 3,000 or less, according to claim 3 or 4. The composition as described.   6. The composition according to claim 1, wherein the porogen (B) has an average particle size of 5 μm or more and less than 900 μm.   The composition according to any one of claims 1 to 6, wherein the shape is particulate.

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