JP2011162645A - Porous structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous structure which is used in the applications of synthetic leather, artificial leather, filters, cushioning materials and the like which excel in the property balance of sweat resistance, hydrolysis resistance, weatherability, flexibility and the like. <P>SOLUTION: The porous structure is obtained by wet membrane formation of a polyurethane resin comprising a reaction product of an organic diisocyanate, a polycarbonate diol, and a chain extender and a 70-100 mol% repeating unit of the polycarbonate diol are repeating units represented by formula (B) (wherein R<SB>2</SB>and R<SB>3</SB>are each a 1-8C aliphatic hydrocarbon group and R<SB>2</SB>and R<SB>3</SB>may be the same or different) or formula (C) (wherein n is an integer of 2-12). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a porous structure used for applications such as synthetic leather, artificial leather, filters, and cushioning materials having excellent balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility.

  As a conventional porous structure, a polyurethane resin solution polymerized using a polyether polyol such as polypropylene glycol or polytetramethylene glycol is applied to a fibrous base material or a film formation slope and solidified in water. There is. Although these porous structures are excellent in flexibility, they have a problem in durability because they are easily decomposed by components such as sweat. There is also a porous structure obtained by coagulation using a polyurethane resin solution polymerized using a polyester polyol obtained by reacting a hydroxy compound and a dibasic acid. This porous structure has a problem in hydrolysis resistance.

In order to solve these problems, a method for obtaining a porous structure using a polyurethane resin solution polymerized using a polycarbonate diol is disclosed. However, the polyurethane resin solution polymerized using polycarbonate diol has problems such as poor wet coagulation and hard texture. In order to solve this problem, a method of wet coagulation using a special film forming aid has been disclosed (see Patent Document 1). However, depending on the amount of the film-forming auxiliary, the surface has a wet feeling or a problem with durability or the like occurs. In addition, when polycarbonate diol with high crystallinity is used, wet coagulation tends to be poor, and therefore a method using a polyurethane solution polymerized using copolycarbonate diol with low crystallinity is disclosed (patent) Reference 2). In addition, a synthetic leather is disclosed in which the polyurethane film layer is formed of an amorphous polycarbonate polyurethane having a 100% modulus of 20 to 200 kg / cm ² (see Patent Document 3). Further, in the synthetic leather in which the polyurethane resin skin layer is laminated on the surface of the fiber base material via the polyurethane resin adhesive layer, the fiber base material layer is a weft knitted fabric having a double-sided knitted structure and forms the polyurethane resin skin layer. A synthetic leather in which the polyurethane resin is a silicone-modified non-yellowing polycarbonate polyurethane is disclosed (see Patent Document 4). Furthermore, an aliphatic oligocarbonate diol obtained by transesterification of an aliphatic diol and a dialkyl carbonate, and a polyester polyol obtained by ring-opening addition polymerization of a cyclic ester compound using a compound having an active hydrogen group as an initiator A synthetic leather surface film layer using a urethane resin comprising a polyester polycarbonate polyol, a polyisocyanate, and a chain extender obtained by a transesterification reaction is disclosed (see Patent Document 5).

  However, the porous structure obtained by these methods has been required to have physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility in a balanced manner. As described above, there has been a demand for a porous structure having an excellent balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility.

  On the other hand, by using a polycarbonate diol having a specific structure, a porous structure having an excellent balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, flexibility, and adhesion has been disclosed (Patent Literature). 6). However, since the polycarbonate diol has a high viscosity, it is difficult to handle, and further, there is a problem that a process for producing a porous structure is required and a large amount of solvent is required.

Japanese Patent No. 3305358 Japanese Patent Laid-Open No. 5-186631 JP-A-5-5280 Japanese Patent Laid-Open No. 9-31862 JP 2005-346094 A JP 2008-37988 A

  The present invention provides a porous structure used for applications such as synthetic leather, artificial leather, filters, and cushioning materials having excellent balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility. For the purpose.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by using a specific polycarbonate diol, and has led to the present invention.

（但し、式中のＲ_１は、炭素数２〜１２の二価の脂肪族又は脂環族炭化水素基を表す。）

（但し、式中のＲ_２及びＲ_３は、炭素数１〜８の脂肪族炭化水素基を表し、Ｒ_２とＲ_３は、同じでもよく異なってもよい。）

（但し、式中のｎは、２から１２の整数。）
そして式（Ｂ）で表される繰り返し単位と式（Ｃ）で表される繰り返し単位との割合が、モル比率で１：９９〜４０：６０であり、該ポリカーボネートジオール（ｂ）の数平均分子量が３００〜１００００であることを特徴とする、上記多孔質構造体、
（２）前記ポリカーボネートジオール（ｂ）において、前記式（Ｃ）で表される繰り返し単位の少なくとも一部が、下記式（Ｄ）で表される繰り返し単位であることを特徴とする、上記（１）に記載の多孔質構造体、

（但し、式中のｎは、４、５，又は６のいずれかの整数。）
を提供するものである。 That is, the present invention
(1) A porous structure obtained by wet-forming a polyurethane resin comprising a reaction product of (a) an organic diisocyanate, (b) a polycarbonate diol, and (c) a chain extender by a wet coagulation method. The polycarbonate diol (b) is a polycarbonate diol having a repeating unit represented by the following formula (A) and a terminal hydroxyl group, and 70 to 100 mol of the repeating unit represented by the formula (A) % Is a repeating unit represented by the following formula (B) or (C),

(However, R ₁ in the formula represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 12 carbon atoms.)

(However, R ₂ and R ₃ in the formula represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and R ₂ and R ₃ may be the same or different.)

(However, n in the formula is an integer of 2 to 12.)
And the ratio of the repeating unit represented by Formula (B) and the repeating unit represented by Formula (C) is 1: 99-40: 60 by molar ratio, The number average molecular weight of this polycarbonate diol (b) Wherein the porous structure is 300 to 10,000,
(2) In the polycarbonate diol (b), at least a part of the repeating unit represented by the formula (C) is a repeating unit represented by the following formula (D), ) Porous structure according to

(However, n in the formula is an integer of 4, 5, or 6)
Is to provide.

  The present invention provides a porous structure used for applications such as synthetic leather, artificial leather, filters, and cushioning materials having excellent balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility. It has the effect of being able to.

  Hereinafter, the present invention will be specifically described.

Polyurethane resin In the present invention, the polyurethane resin comprises a reaction product of an organic diisocyanate (a), a polycarbonate diol (b), and a chain extender (c).

Organic diisocyanate (a)
Examples of the organic diisocyanate (a) used in the present invention include 2,4-triresin diisocyanate, 2,6-triresin diisocyanate and mixtures thereof, diphenylmethane-4,4′-diisocyanate (MDI), and naphthalene-1,5-diisocyanate. Aromatic diisocyanates such as (NDI), 3,3′-dimethyl-4,4′biphenylene diisocyanate (TODI), crude TDI, polymethylene polyphenylene polyisocyanate (PMDI), crude MDI, xylylene diisocyanate (XDI), phenylene diisocyanate Araliphatic diisocyanates such as 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), It can be exemplified aliphatic diisocyanates such as cyclohexane diisocyanate (hydrogenated XDI), but is not limited to. Usually, one type of organic diisocyanate is selected and used, but two or more types may be selected from these organic diisocyanates, and these may be mixed or sequentially added. The amount of the organic diisocyanate used is usually 0.95 to 1.2 equivalents relative to the total amount of polycarbonate diol and chain extender.

Polycarbonate diol (b)
The polycarbonate diol (b) used in the present invention can be obtained by subjecting it to transesterification using diol and carbonate as raw materials.

In the present invention, 2,2-dialkyl-substituted-1,3-propanediol (hereinafter referred to as 2,2-substituted PDL) and a diol having no side chain are used as the diol, but are not limited thereto. By using 2,2-substituted PDL as a raw material, the repeating unit represented by the formula (B) can be introduced into the polycarbonate diol (b). By using a diol having no side chain as a raw material, the repeating unit represented by the formula (C) can be introduced into the polycarbonate diol (b).
The 2,2-substituted PDL is 1,3-propanediol in which the carbon at the 2-position is substituted with an aliphatic hydrocarbon having 1 to 8 carbon atoms, 2,2-diethyl-1,3-propanediol, Examples include 2-butyl-2-ethyl-1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol. Is not limited.
Examples of the aliphatic diol having no side chain include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 , 8-octanediol, 1,9-nanodiol, 1,10-dodecanediol, 1,11-undecanediol, 1,12-dodecanediol, and the like, but are not limited thereto.
One or a plurality of diols can be selected and used from the 2,2-substituted PDL and the aliphatic diol having no side chain.

  Since 2,2-substituted PDL has as few as 3 carbon atoms in the main chain, the polycarbonate diol obtained using it has a high carbonate bond density. Thereby, the sweat resistance of the porous structure is improved. On the other hand, since the 2,2-substituted PDL has a bulky structure in which two alkyl groups are bonded to one carbon, regularity is greatly reduced by introducing the structure into polycarbonate diol. Furthermore, since 2-butyl-2-ethyl-1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol, and the like have side chains with more carbon atoms than the main chain, Alternatively, the interaction between carbonate bonds in the molecule tends to be inhibited. Due to the above effects, the polycarbonate diol using 2,2-substituted PDL as a raw material has high flexibility, and the viscosity of the polyurethane solution is lower than that of the polycarbonate diol not having the above structure. Furthermore, the flexibility and strength of the porous structure can be controlled by combining a 2,2-substituted PDL having a bulky structure and an aliphatic diol having no side chain. When 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol is used, a balance between flexibility and strength is preferable. By using any of these three diols, the repeating unit represented by the formula (D) can be introduced into the polycarbonate diol (b). It is preferable that at least a part of the repeating unit represented by the formula (C) in the polycarbonate diol (b) is a repeating unit represented by the formula (D), and all of the repeating units represented by the formula (C) are represented by the formula (C). The repeating unit represented by D) is particularly preferred.

  Ratio of repeating units derived from 2,2-substituted PDL in the molecule (the above formula (B)) and repeating units derived from a diol having no side chain (the above formula (C)) (hereinafter referred to as a copolymerization ratio) The above formula (B): represented by the above formula (C)) is 1:99 to 40:60 in molar ratio. If the molar ratio of the repeating units derived from 2,2-substituted PDL is 40 or less, the strength is not insufficient. On the other hand, if the molar ratio of the repeating units derived from 2,2-substituted PDL is 1 or more, sweat resistance is not insufficient and flexibility is also improved. When the copolymerization ratio is 3:97 to 25:75, it is preferable because a porous structure having flexibility and high strength and high sweat resistance can be obtained, and is preferably 5:95 to 15:85. Most preferred.

  Further, 2-methyl-1,8-octanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4- Diols having side chains such as dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl)- One kind or two or more kinds of diols can be selected and used as a raw material from cyclic diols such as propane. The amount of the repeating unit represented by the above formula (B) or (C) in the repeating unit represented by the above formula (A) (hereinafter referred to as the main component ratio) is less than 70 mol%. It is decided in the range which cannot be. A main component ratio of 70% or more is preferable because problems such as a decrease in strength of the porous structure and insufficient sweat resistance are suppressed. If it is 85% or more, more preferably 90% or more, a porous structure having high strength and sweat resistance can be obtained.

  In addition, in the production of the polycarbonate diol according to the present invention, a small amount of a compound having 3 or more hydroxyl groups per molecule, for example, trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol and the like can be used. In this case, since the produced polycarbonate diol has a part of the triol component, it is precisely “polycarbonate polyol”. However, in this case, for convenience, the polycarbonate diol is referred to as “polycarbonate diol”. To do. When too many compounds having three or more hydroxyl groups in one molecule are used, gelation occurs due to crosslinking during the polymerization reaction of the polycarbonate. Therefore, when a compound having 3 or more hydroxyl groups in one molecule is used, the content is preferably 0.1 to 5 mol% based on the total amount of 2,2-substituted PDL and aliphatic diol having no side chain. preferable. More preferably, it is 0.1-2 mol%, More preferably, it is 0.1-0.5 mol%.

（式中、Ｒ_２はアルキレン基を表し、該アルキレン基は２種類以上であっても構わない。また、ｘは２以上の整数を表す。）
ポリカーボネートジオール分子中の式（Ｅ）の繰り返し単位の含有量は、本発明に影響しない範囲であれば特に限定するものではないが、その量が増えると耐熱性や耐薬品性が低下する。下記式（Ａ）で表されるカーボネートの繰り返し単位に対し上記式（Ｅ）で表されるエーテルの繰り返し単位が０．０５〜５モル％以下であることが好ましく、０．０５〜３モル％以下であることがさらに好ましい。 The range of the average molecular weight of the polycarbonate diol (b) used in the present invention is 300 to 10,000, preferably 400 to 5,000, more preferably 400 to 2,500 in terms of number average molecular weight. For this purpose, the molecule may contain a structure represented by a repeating unit of the following formula (E).

(In the formula, R ₂ represents an alkylene group, and the alkylene group may be of two or more types. X represents an integer of 2 or more.)
The content of the repeating unit of the formula (E) in the polycarbonate diol molecule is not particularly limited as long as it does not affect the present invention, but heat resistance and chemical resistance decrease as the amount increases. It is preferable that the repeating unit of the ether represented by the above formula (E) is 0.05 to 5 mol% or less with respect to the repeating unit of carbonate represented by the following formula (A), More preferably, it is as follows.

  As the polycarbonate diol used in the present invention, carbonate esters such as alkylene carbonate, dialkyl carbonate and diaryl carbonate are used as raw materials, but are not limited thereto. Examples of the alkylene carbonate include, but are not limited to, ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 1,2-pentylene carbonate, and the like. . Further, examples of the dialkyl carbonate include dimethyl carbonate, diethyl carbonate, and di-n-butyl carbonate, and examples of the dialkylene carbonate include diphenyl carbonate, but are not limited thereto. Of these, ethylene carbonate, dimethyl carbonate, and diethyl carbonate are preferably used, and ethylene carbonate is more preferably used.

  The method for producing the polycarbonate diol of the present invention is not particularly limited. For example, it can be produced by various methods described in Schnell, Polymer Reviews Vol. 9, p9-20 (1994).

Chain extender (c)
Examples of the chain extender (c) used in the present invention include short-chain diols such as ethylene glycol and 1,4-butanediol, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, and diamino. Examples include, but are not limited to, diamines such as diphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine, and water. Normally, one type of chain extender is selected and used, but two or more types may be selected from these chain extenders and used in combination. The amount of the chain extender used is usually 50 to 500 moles, where the number of moles of the polycarbonate diol (b) is 100.

Production of polyurethane resin The polyurethane resin of the present invention can be obtained by methods known in the polyurethane industry. For example, a polycarbonate diol and an organic diisocyanate are reacted at 20 to 150 ° C. for 2 to 12 hours to synthesize a urethane prepolymer having an isocyanate group at the end, and then a chain extender is added thereto at 20 to 150 ° C. A prepolymer method for reacting for 2 to 12 hours, or adding a polycarbonate diol, an organic isocyanate, and a chain extender all at once, and reacting at 20 to 150 ° C. for 3 to 12 hours. There is a one-shot method for obtaining a molecular weight.

  In this reaction, a urethane reaction catalyst can be added as necessary. Examples of the catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine and morpholine, metal salts such as potassium acetate, zinc stearate and tin octylate, and organometallic compounds such as dibutyltin dilaurate. A polymerization terminator can also be added as needed. As the polymerization terminator, monohydric alcohols such as methanol, butanol and cyclohexanol, dibutylamine and the like can be used. These reactions may be performed in a solvent, or after reacting without a solvent, a solvent may be added to dissolve the polyurethane resin.

  As the organic solvent, dimethylformamide (DMF), dimethylsulfoxide, diethylformamide, dimethylacetamide, tetrahydrofuran (THF), methyl ethyl ketone (MEK), dioxane, acetone, cyclohexane, toluene and the like can be used. These organic solvents can be used as one kind or a mixture of two or more kinds. Practically preferred organic solvents are amide solvents, with DMF being particularly preferred. The concentration of the polyurethane resin solution in the organic solvent is generally 5 to 50% by weight.

  A film forming aid may be added to the polyurethane resin solution. As film forming aids, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, melicic acid and other aliphatic carboxylic acids having a relatively large number of carbon atoms, octyl alcohol, nonyl alcohol, decyl Long chain alcohols such as alcohol, dodecyl alcohol, tetradecyl alcohol, cetyl alcohol, stearyl alcohol and the like can be mentioned. Further, a carboxylic acid ester obtained from an alkyl alcohol having 1 to 6 carbon atoms and an aliphatic carboxylic acid having 6 to 18 carbon atoms, glycerin and an aliphatic carboxylic acid monoester having 10 to 22 carbon atoms, a diester, a triester, and sorbitan Examples thereof include aliphatic carboxylic acid monoesters and diester triesters having 10 to 22 carbon atoms.

  If necessary, the polyurethane resin solution may include a colorant, an antioxidant, an ultraviolet absorber, a flame retardant, a water / oil repellent, a deodorant, an antistatic agent, an aromatic, a release agent, a lubricant, a filler, An additive such as a foaming agent may be added alone or in combination of two or more. Furthermore, if necessary, synthetic rubber, polyvinyl chloride or vinyl chloride copolymer, vinyl acetate or vinyl acetate copolymer, amino acid resin, polyurethane / polyamino acid block copolymer, polyester elastomer, polyamide elastomer, polyamide, etc. A polymer can also be added.

Porous structure The porous structure of the present invention can be obtained by applying or impregnating a polyurethane resin solution to a substrate and wet coagulating it. Moreover, you may peel and use the obtained porous structure from a base material as needed.

  Various substrates can be used as the substrate. For example, examples of the fibrous base material include a fiber assembly in which the fibers are formed into a nonwoven fabric, a woven fabric, a net cloth, or the like, or a fiber assembly in which each fiber of the fiber assembly is bonded with an elastic polymer. Examples of the fibers used in this fiber assembly include natural fibers such as cotton, hemp and wool, regenerated or semi-synthetic fibers such as rayon and acetate, and synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol and polyolefin. These fibers may be single-spun fibers or mixed-spun fibers. Examples of other substrates include paper, release paper, polyester and polyolefin plastic films, metal plates such as aluminum, and glass plates.

  When the substrate is a raised fabric, a knitted fabric, or a non-woven fabric, the polyurethane resin solution applied to the surface easily penetrates into the substrate, and the flexibility is inferior. Therefore, it is possible to pre-treat the substrate in advance. As the pretreatment method, there are a method of treating the substrate with a fluorine-based water repellent or the like, and a method of crushing and smoothing the swelling of the substrate through a calendar.

  The application or impregnation of the polyurethane resin solution is generally performed by a commonly used method. Examples of the coating method include a floating knife coater, a knife over roll coater, a reverse roll coater, a roll doctor coater, a gravure roll coater, and a kiss roll coater.

  As a wet coagulation method, for example, a base material impregnated or coated with a polyurethane resin solution has an affinity with a solvent of the polyurethane resin solution, and the polyurethane resin has no affinity and is directly immersed in a coagulation bath which is a non-solvent. There is a method of coagulating by extracting the organic solvent. Examples of non-solvents that have an affinity for the above organic solvents and no affinity for polyurethane resins include water, ethylene glycol, glycerin, ethylene glycol monoethyl ether, hydroxyethyl acetate, and the like. A mixture of more than one type can be used. Furthermore, an organic solvent can also be mixed and used in arbitrary ratios.

  The temperature of the coagulation bath is usually 30 to 50 ° C. When the temperature is lower than 30 ° C. or higher than 50 ° C., in the case of a polycarbonate diol-based polyurethane resin, a porous structure is often not obtained, which is not preferable in practice. The coagulation process can be performed continuously in several stages. In this case, the first stage coagulation bath temperature is preferably 30 to 50 ° C. In the coagulation bath after the first stage, the temperature can be set on either the high temperature side or the low temperature side as necessary. After wet coagulation, washing and drying are performed by a normal method.

  In the present invention, when the substrate has a large porosity such as a knitted fabric, when the polyurethane resin solution is directly applied or impregnated, the polyurethane resin may penetrate into the entire substrate and reduce flexibility. In that case, a laminating method in which an adhesive is interposed may be employed. As the adhesive, polyurethane, polyacryl, polyamide, polyester, or the like can be used, but it is preferable to use polyurethane. The adhesive can be applied to the entire surface of the porous structure, but from the viewpoint of texture and moisture permeability, the adhesive is applied to the surface of the porous structure in the form of dots or lines and laminated. The method is preferred.

  The obtained porous structure can be used as it is, but for the purpose of imparting various properties, a polymer solution or an emulsion such as polyurethane resin, vinyl chloride or cellulose resin is applied, or a separate release paper is used. It can also be used as a laminate obtained by peeling off the release paper after pasting the above-mentioned polymer solution or emulsion coated thereon with a coating obtained by drying.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited at all by these examples.
1) Average molecular weight of polycarbonate diol Hydroxyl value is determined by “neutralization titration method (JIS K 0070-1992)” in which acetic anhydride and pyridine are used and titrated with an ethanol solution of potassium hydroxide, and the following formula (1) is used. The number average molecular weight was calculated.

Number average molecular weight = 2 / (OH value × 10 ⁻³ /56.1) (1)
2) Copolymerization ratio and main component ratio of polycarbonate diol 1 g of a sample is taken into a 100 ml eggplant flask, and 30 g of ethanol and 4 g of potassium hydroxide are added and reacted at 100 ° C. for 1 hour. After cooling to room temperature, add 2-3 drops of phenolphthalein to the indicator and neutralize with hydrochloric acid. After cooling in the refrigerator for 1 hour, the precipitated salt is removed by filtration, and using gas chromatography (GC), it is derived from the 2,2-substituted PDL derived from the repeating unit (B) and the formula (C). The diol was quantified. GC analysis was performed using gas chromatography GC-14B (manufactured by Shimadzu Corporation, Japan) with DB-WAX (manufactured by J & W, USA) as a column, diethylene glycol diethyl ester as an internal standard, and a detector as FID. The temperature rising profile of the column was maintained at 60 ° C. for 5 minutes and then heated to 250 ° C. at 10 ° C./min.
(i) Copolymerization ratio Using the above analysis results, the molar ratio of 2,2-substituted PDL to diol other than 2,2-substituted PDL (number of moles of 2,2-substituted PDL: diol other than 2,2-substituted PDL) The total number of moles).
(ii) Main component ratio Based on the above analysis results, the main component ratio was determined by the following mathematical formula (2).

Main component ratio (mol%) = (B + C) / A × 100 (2)
B: Number of moles of 2,2-substituted PDL C: Total number of moles of diol derived from the above formula (C) A: Total number of moles of diol derived from the above formula (A) 3) Viscosity The viscosity was measured at 50 ° C. using a viscometer TVE-20H (manufactured by Toki Sangyo).
4) Sweat resistance Oleic acid was used as a substitute for sweat. The sample was immersed in oleic acid at 45 ° C. for 1 week, and the surface was observed. Sweat resistance was evaluated by assuming that the case where there was no change from before immersion was good (◯), the case where a feeling of sliminess was felt (Δ), and the case where the surface shape was changed was impossible (×).
5) Weather resistance The porous body was cut into 5 cm × 5 cm to obtain sample pieces. The test piece surface properties in the sunshine type weatherometer WEL-SUN-DC (manufactured by Suga Test Instruments Co., Ltd.) after a predetermined time (200 hours) with one cycle of 60 minutes and 12 minutes of precipitation repeated. The change was visually observed, and the change was evaluated in five stages from the first grade (no change compared to the untested test piece) to the fifth grade (the porous body was broken).
6) Flexibility Since the porous structure created in Comparative Example 2 to be described later corresponds to a synthetic leather material that has been used in the past, whether or not it is flexible is determined based on the tactile sensation based on this material. evaluated.
[Polycarbonate diol polymerization example 1]
655 g (7.4 mol) of ethylene carbonate and 150 g of 2-butyl-2-ethyl-1,3-propanediol (0,0 .mu.m) were added to a 2 L glass flask equipped with a rectification column packed with a regular packing and a stirring device. 9 mol) and 750 g (6.4 mol) of 1,6-hexanediol were charged. 0.10 g of titanium tetrabutoxide was added as a catalyst, and the mixture was stirred and heated at normal pressure. The reaction was carried out at a reaction temperature of 140 ° C. to 150 ° C. and a pressure of 3.0 to 5.0 kPa for 20 hours while distilling off the resulting mixture of ethylene glycol and ethylene carbonate. Thereafter, the pressure was reduced to 0.5 kPa, and the reaction was further performed at 150 to 160 ° C. for 14 hours while distilling off ethylene carbonate and diol. When the obtained polycarbonate diol was analyzed, the number average molecular weight was 2007, the main component ratio was 100 mol%, and the copolymerization ratio was 12:88. This polycarbonate diol is referred to as PC1.
[Polycarbonate diol polymerization example 2]
Using the same apparatus as in polymerization example 1 of polycarbonate diol, 700 g (8.0 mol) of ethylene carbonate, 330 g (2.1 mol) of 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol 520 g (5.9 mol) was charged. Titanium tetrabutoxide (0.10 g) was added as a catalyst, and the reaction was performed under the same conditions as in Synthesis Example 1 for polycarbonate diol. When the obtained polycarbonate diol was analyzed, the number average molecular weight was 1989, the main component ratio was 100 mol%, and the copolymerization ratio was 24:76. This polycarbonate diol is referred to as PC2.
[Polycarbonate diol polymerization example 3]
Polycarbonate except that 360 g (4.0 mol) of 2-methyl-1,3-propanediol, 390 g (3.3 mol) of 1,6-hexanediol, and 640 g (7.3 mol) of ethylene carbonate were used. The molecular weight of the obtained polycarbonate diol, which was reacted in the apparatus and conditions shown in Polymerization Example 1 for diol, was 1997, and the main component ratio was 49 mol%. This polycarbonate diol is referred to as PC3.
[Polymerized diol polymerization example 4]
The obtained polycarbonate diol was reacted using the apparatus and conditions shown in Polymerization Example 1 of polycarbonate diol, except that 705 g (6.0 mol) of 1,6-hexanediol and 525 (6.0 mol) of ethylene carbonate were used. The molecular weight of 1992 was 1992 and the copolymerization ratio was 0: 100. This polycarbonate diol is referred to as PC4.
[Synthesis Examples 1 to 4 of polyurethane]
A reactor equipped with a reflux condenser, a thermometer, and a stirrer is charged with 330 g of polycarbonate diol (hereinafter abbreviated as PCD) and dimethylformamide (hereinafter abbreviated as DMF) and sufficiently stirred. 0.017 g of dibutyltin dilaurate as a catalyst and isophorone diisocyanate (hereinafter abbreviated as IPDI) were added and reacted at 75 ° C. for 5 hours to obtain a prepolymer having an isocyanate terminal. After the temperature was lowered to 40 ° C., isophoronediamine (hereinafter abbreviated as IPDA) was added, and when the number average molecular weight reached 70,000, 1 g of n-hexylamine was added to stop the reaction.

  Table 1 below shows the amounts of raw materials for polyurethane. The obtained polyurethane is referred to as PU1 to PU4.

得られたポリウレタン溶液の粘度を下記表２に示す。表２に示す値は、合成例４のポリウレタンの粘度を１とする相対値で表した。

The viscosity of the obtained polyurethane solution is shown in Table 2 below. The values shown in Table 2 were expressed as relative values with the viscosity of the polyurethane of Synthesis Example 4 being 1.

［実施例１］
７０デニールのナイロン６６基布（経密度１３６本／インチ、緯密度１０４本／インチ）を、０．８％のフッ素系撥水剤（明成化学株式会社製、アサヒガードＬＳ３１７）を入れた浴に浸漬し、絞り率８０％で絞った後、１５０℃の乾燥機で５分間乾燥した。該基布の上に、アプリケータを用いて、クリアランス１００μｍでポリウレタン樹脂溶液ＰＵ１を塗布した。２５℃の１０％ＤＭＦ水溶液に５分間浸漬して湿式凝固した後、６５℃の温水に５分間浸漬して溶媒を取り除いた後、絞液ロールで絞り、１１０℃で乾燥して多孔質構造体１を得た。
［実施例２］
ポリウレタン溶液ＰＵ２を用いた以外は実施例１と同様の方法で多孔質構造体２を得た。
［比較例１〜２］
ポリウレタン樹脂溶液ＰＵ３又はＰＵ４を用いた以外は、実施例１と同様の方法で多孔質構造体（以下、ポリウレタン樹脂溶液ＰＵ３を用いた多孔質構造体を構造体３、ポリウレタン樹脂溶液４を用いた多孔質構造体を構造体４とそれぞれ称す。）を得た。

[Example 1]
70 denier nylon 66 base fabric (warp density 136 / inch, weft density 104 / inch) in a bath containing 0.8% fluorinated water repellent (Aseihi LS317, manufactured by Meisei Chemical Co., Ltd.) After dipping and squeezing at a squeezing rate of 80%, it was dried with a dryer at 150 ° C. for 5 minutes. On the base fabric, a polyurethane resin solution PU1 was applied with a clearance of 100 μm using an applicator. Porous structure by dipping in a 10% DMF aqueous solution at 25 ° C. for 5 minutes to wet solidify, then dipping in warm water at 65 ° C. for 5 minutes to remove the solvent, squeezing with a squeezing roll, and drying at 110 ° C. 1 was obtained.
[Example 2]
A porous structure 2 was obtained in the same manner as in Example 1 except that the polyurethane solution PU2 was used.
[Comparative Examples 1-2]
Except for using the polyurethane resin solution PU3 or PU4, the porous structure (hereinafter, the porous structure using the polyurethane resin solution PU3 was used as the structure 3 and the polyurethane resin solution 4 was used in the same manner as in Example 1. The porous structure was referred to as the structure 4 respectively).

  The resulting porous structure was evaluated for weather resistance, sweat resistance and flexibility, and the results are shown in Table 3 below.

  It can be used for applications such as synthetic leather, artificial leather, filters, and cushioning materials that have a good balance of physical properties such as sweat resistance, hydrolysis resistance, weather resistance, and flexibility.

Claims (2)

A porous structure obtained by wet film-forming a polyurethane resin comprising a reaction product of (a) an organic diisocyanate, (b) a polycarbonate diol, and (c) a chain extender, The polycarbonate diol (b) is a polycarbonate diol having a repeating unit represented by the following formula (A) and a terminal hydroxyl group, and 70 to 100 mol% of the repeating unit represented by the formula (A) is A repeating unit represented by formula (B) or (C),

(However, R ₁ in the formula represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 12 carbon atoms.)

(However, R ₂ and R ₃ in the formula represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and R ₂ and R ₃ may be the same or different.)

(However, n in the formula is an integer of 2 to 12.)
And the ratio of the repeating unit represented by Formula (B) and the repeating unit represented by Formula (C) is 1: 99-40: 60 by molar ratio, The number average molecular weight of this polycarbonate diol (b) Is 300 to 10000, The porous structure as described above, 2. The polycarbonate diol (b) according to claim 1, wherein at least a part of the repeating unit represented by the formula (C) is a repeating unit represented by the following formula (D). Porous structure.

(However, n in the formula is an integer of 4, 5, or 6)