KR102535128B1 - Polyurethane porous body and method for producing polyurethane porous body - Google Patents

Abstract

The polyurethane porous body includes an aqueous urethane polymer. An aqueous urethane polymer is a polyol compound (A) containing polyether polyol and polycaprolactone polyol, a polyisocyanate compound (B), a hydrophilic compound (C) having reactivity with an isocyanate group, and two hydroxyl groups in a molecule. It is a reactant of a component containing one or more short-chain diol compounds (D).

Description

Polyurethane porous body and method for producing polyurethane porous body

The present invention relates to a polyurethane porous body and a method for producing the polyurethane porous body. This application claims priority based on Japanese application No. 2018-30990 for which it applied on February 23, 2018, and uses all the description content described in the said Japanese application.

Polyurethane porous bodies are used for cosmetic sponges and the like. As one of the methods for producing such a polyurethane porous body, a wet coagulation method is known (for example, Patent Document 1).

Patent Document 1: Japanese Unexamined Patent Publication No. 2015-116370

In the wet coagulation method described above, for example, a kneaded composition obtained by kneading a polyurethane resin, a solvent, and an inorganic salt is first prepared. Then, the kneaded composition is degassed to form a molded body. The obtained molded body is solidified in water, and inorganic salts are extracted with water and removed from the solidified molded body. After that, it is dried to form a polyurethane porous body in which a plurality of pores are formed. Also, in the wet coagulation method, the pore size is controlled according to the particle size of the inorganic salt.

When using the polyurethane porous body as described above for a cosmetic sponge, it is preferable to increase flexibility and extensibility in order to improve texture such as touch. However, in the wet coagulation method, since the inorganic salt is extracted and removed with water, the shrinkage rate of the polyurethane porous body increases in the molding step, and the flexibility of the polyurethane porous body may decrease.

Therefore, one of the objects is to provide a polyurethane porous body having high flexibility and extensibility.

The polyurethane porous body according to the first aspect of the present invention includes an aqueous urethane polymer.

The water-based urethane polymer is a polyol compound (A) containing polyether polyol and polycaprolactone polyol, a polyisocyanate compound (B), a hydrophilic compound having reactivity with an isocyanate group (C), and two or more hydroxyl groups in a molecule. The branch is a reactant of a component containing a short-chain diol compound (D).

Further, the method for producing a polyurethane porous body according to the second aspect of the present invention is a polyol compound including polyether polyol and polycaprolactone polyol, a polyisocyanate compound, a hydrophilic compound reactive with an isocyanate group, and a molecule A step of preparing a raw material containing a short-chain diol compound having two or more hydroxyl groups, a polyol compound, a polyisocyanate compound, a hydrophilic compound having reactivity with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule to form a urethane prepolymer by reacting, stirring the urethane prepolymer, water and a surfactant together, dispersing the urethane prepolymer in water to form an O/W (Oil　In　Water) type emulsion, and further adding a water-soluble polymer to , A step of forming a urethane prepolymer aqueous dispersion containing water, an O/W type emulsion and a water-soluble polymer, a step of adding an amine compound to the urethane prepolymer aqueous dispersion and causing a crosslinking reaction to form an aqueous urethane polymer, and an aqueous urethane A process for removing moisture from the polymer is provided.

According to the present invention, it is possible to provide a polyurethane porous body having high flexibility and extensibility.

1 is a flowchart showing an outline of a method for producing a polyurethane porous body.

[Description of Embodiments of the Present Invention]

Embodiment of this invention is listed and demonstrated for the first time. The polyurethane porous body according to the first aspect of the present application includes an aqueous urethane polymer. The water-based urethane polymer is a polyol compound (A) containing polyether polyol and polycaprolactone polyol, a polyisocyanate compound (B), a hydrophilic compound having reactivity with an isocyanate group (C), and two or more hydroxyl groups in a molecule. The branch is a reactant of a component containing a short-chain diol compound (D).

The material constituting the polyurethane porous body of the present application includes an aqueous urethane polymer. A water-based urethane polymer is obtained by dispersing a urethane prepolymer obtained by reacting a polyol compound, a polyisocyanate compound, a hydrophilic compound having reactivity with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule in water, followed by a crosslinking reaction. will be. The hydroxyl group in the polyol compound and the isocyanate group in the polyisocyanate compound react to form a urethane polymer. By including a short-chain diol compound having two or more hydroxyl groups in the molecule, the chain length can be extended and the urethane polymer can be made high in molecular weight. By including a hydrophilic compound having reactivity with an isocyanate group, the dispersibility of the urethane prepolymer in water is improved, and fine pores can be provided in the porous body.

A urethane polymer having high flexibility is obtained by using polyether polyol as the polyol compound. Further, a urethane polymer having high strength can be obtained by using polycaprolactone polyol as the polyol compound. By using polyether polyol and polycaprolactone polyol together as polyol compounds, a soft urethane polymer having strength capable of withstanding deformation is obtained. For this reason, a polyurethane porous body having high flexibility and extensibility can be obtained.

Thus, according to the polyurethane porous body of the present application, a polyurethane porous body having high flexibility and extensibility can be provided.

In the polyurethane porous body, the hydrophilic compound (C) having reactivity with an isocyanate group may contain a polyhydroxy compound having two or more hydroxyl groups in a molecule. In this way, by including a polyhydroxy compound having two or more hydroxyl groups in the molecule, the dispersibility of the urethane prepolymer in water is further improved, and finer pores can be formed in the porous body.

In the polyurethane porous body, the polyisocyanate compound (B) may contain aromatic polyisocyanate and aliphatic polyisocyanate. Thus, by including two types of isocyanate components, the flexibility and extensibility of the polyurethane porous body can be further improved, and the polyurethane porous body with suppressed yellowing can be obtained.

In the polyurethane porous body, the content of the aromatic polyisocyanate relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C) and the short-chain diol compound (D) is 8% by mass or more and 17% by mass It may be made below. By setting the content of aromatic polyisocyanate to 8% by mass or more, both the flexibility and extensibility of the polyurethane porous body can be improved. When the content of the aromatic polyisocyanate is 17% by mass or less, yellowing of the polyurethane porous body can be suppressed.

In the polyurethane porous body, the mass ratio (polyether polyol/polycaprolactone polyol) between the amount of polyether polyol and the amount of polycaprolactone polyol may be 1 or more and 4 or less. By setting it as such range, both the flexibility and extensibility of a polyurethane porous body can be improved.

The method for producing a polyurethane porous body according to the second aspect of the present application is a polyol compound including polyether polyol and polycaprolactone polyol, a polyisocyanate compound, a hydrophilic compound reactive with an isocyanate group, and a hydroxyl group in a molecule A step of preparing a raw material containing a short-chain diol compound having two or more, a polyol compound, a polyisocyanate compound, a hydrophilic compound reactive with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule are reacted In the process of forming a urethane prepolymer, the urethane prepolymer, water and a surfactant are stirred together, the urethane prepolymer is dispersed in water to form an O/W (Oil In Water) type emulsion, a water-soluble polymer is further added, and water and A step of forming a urethane prepolymer aqueous dispersion containing an O/W type emulsion and a water-soluble polymer, a step of adding an amine compound to the urethane prepolymer aqueous dispersion and causing a crosslinking reaction to form an aqueous urethane polymer, and water from the aqueous urethane polymer Equipped with a process to remove.

As one of the methods for increasing the flexibility of the polyurethane porous body, it is conceivable to lower the density of the polyurethane porous body. The density of the polyurethane porous body can be lowered by increasing the proportion of water in the urethane prepolymer aqueous dispersion and reducing the concentration of the non-volatile content. However, if the proportion of water is increased, the cohesiveness of the O/W type emulsion is lowered, and a three-dimensional network structure cannot be formed in some cases. By the way, in the method for producing a polyurethane porous body related to the second aspect of the present application, a water-soluble polymer that dissolves in water and has a thickening property is added to the urethane prepolymer aqueous dispersion to lower the concentration of the non-volatile matter in the urethane prepolymer aqueous dispersion. , it is possible to form a low-density polyurethane porous body.

In addition, in the method for producing a polyurethane porous body according to the second aspect of the present application, two specific types of polyol compounds are included as the polyol compound. Two specific polyol compounds are polyetherpolyols and polycaprolactonepolyols. By doing in this way, the polyurethane porous body can be made soft and easy to deform. For this reason, the flexibility and extensibility of the polyurethane porous body are improved.

In this way, according to the method for producing a polyurethane porous body of the present application, a polyurethane porous body having high flexibility and extensibility can be provided.

[Details of the embodiment of the present invention]

Next, one embodiment of the polyurethane porous body of the present invention will be described. The polyurethane porous body according to the present embodiment includes an aqueous urethane polymer. Here, the water-based urethane polymer is obtained by crosslinking an aqueous urethane prepolymer dispersion obtained by dispersing a urethane prepolymer in water. The content of the aqueous urethane polymer in the polyurethane porous body is 80% by mass or more and 100% by mass or less.

The polyurethane porous body in this embodiment has a structure of an open cell body. More specifically, it has a structure in which pores are formed inside the polyurethane porous body and small holes are formed on the wall surface defining the pores to communicate with each other. By doing in this way, the polyurethane porous body can be made lightweight. In addition, the liquid can be absorbed and the liquid can be retained inside the polyurethane porous body.

The water-based urethane polymer is a polyol compound (A) containing polyether polyol and polycaprolactone polyol, a polyisocyanate compound (B), a hydrophilic compound having reactivity with an isocyanate group (C), and two or more hydroxyl groups in a molecule. The branch is a reactant of a component containing a short-chain diol compound (D). That is, the water-based urethane polymer in the present embodiment includes a structural unit derived from a polyol compound (A), a structural unit derived from a polyisocyanate compound (B), a structural unit derived from a hydrophilic compound (C) having reactivity with an isocyanate group, and a molecule A structural unit derived from the short-chain diol compound (D) having two or more hydroxyl groups is included in the inside.

In the present embodiment, at least polyether polyol and polycaprolactone polyol are included as the polyol compound. By including two types of polyol components in this way, the polyurethane porous body can be made soft and easily deformed. The content of the polyether polyol and the polycaprolactone polyol relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C) and the short-chain diol compound (D) is preferably 50% by mass or more and 70% by mass. % or less, more preferably 50 mass% or more and 65 mass% or less, still more preferably 50 mass% or more and 60 mass% or less.

The mass ratio (polyether polyol/polycaprolactone polyol) of the blending amount of the polyether polyol and the blending amount of the polycaprolactone polyol is preferably 1 or more and 4 or less. By setting it as such range, both the flexibility and extensibility of a polyurethane porous body can be improved. The preferred range of the mass ratio (polyether polyol/polycaprolactone polyol) is 1 or more and 3.8 or less, more preferably 1 or more and 3.5 or less.

As the polyether polyol, one obtained by polymerizing an alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) can be used. More specifically, polyethylene glycol, polypropylene glycol, polyethylene-polypropylene (block or random) glycol, polyethylene-tetramethylene glycol (block or random), polytetramethylene glycol, poly-2-methyl tetramethylene glycol, polyhexa Methylene glycol etc. are mentioned. Especially, polytetramethylene glycol can be used suitably.

As the polycaprolactone polyol, polycaprolactone diol, polycaprolactone triol and the like can be used. Especially, polycaprolactone diol can be used suitably.

As the polyol compound, in addition to polyether polyol and polycaprolactone polyol, polyols used in the production of normal polyurethanes and having two or more hydroxyl groups in the molecule may be included. Examples of such polyols include polycarbonate polyols, polyolefin polyols, acrylic polyols, castor oil polyols, and silicone polyols, and these may be used alone or in combination of two or more.

The number average molecular weight of the polyol compound is preferably 500 to 5000, more preferably 500 to 4000, and particularly preferably 500 to 3000. The number average molecular weight is measured by GPC (Gel Permission Chromatography) and calculated from a value calculated in terms of polystyrene. The hydroxyl value of the polyol compound is preferably 22 mgKOH/g to 340 mgKOH/g, more preferably 28 mgKOH/g to 340 mgKOH/g, and particularly preferably 37 mgKOH/g to 340 mgKOH/g. .

The polyisocyanate compound (B) has two or more isocyanate groups at terminals in the molecule. As the polyisocyanate compound (B) in the present embodiment, for example, aromatic polyisocyanates and their hydrogenated products, alicyclic polyisocyanates, aliphatic polyisocyanates, etc. can be used, and these are used alone or in a mixture of two or more types. It can be. Especially, what contains aromatic polyisocyanate and aliphatic polyisocyanate is preferable. In this way, by including the specific two types of polyisocyanate compounds, the flexibility and extensibility of the polyurethane porous body can be further improved, and yellowing of the polyurethane porous body can be suppressed.

When aromatic polyisocyanates and aliphatic polyisocyanates are included as the polyisocyanate compound (B), aromatics relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C) and the short-chain diol compound (D) The content of polyisocyanate is preferably 8% by mass or more and 17% by mass or less, more preferably 9% by mass or more and 15% by mass or less, and still more preferably 10% by mass or more and 15% by mass or less. By setting the content of aromatic polyisocyanate to 8% by mass or more, both the flexibility and extensibility of the polyurethane porous body can be improved. In addition, when the content of aromatic polyisocyanate is 17% by mass or less, yellowing of the polyurethane porous body can be suppressed.

Examples of aromatic polyisocyanates and hydrogenated substances thereof include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dichloro-4, 4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated chlorine Silylene diisocyanate etc. are mentioned. Especially, 4,4'- diphenylmethane diisocyanate can be used suitably.

As alicyclic polyisocyanate, 1, 4- cyclohexane diisocyanate, isophorone diisocyanate, norbornane diisocyanate etc. are mentioned, for example. As aliphatic polyisocyanate, tetramethylene diisocyanate, 1, 5- pentamethylene diisocyanate, 1, 6- hexamethylene diisocyanate etc. are mentioned, for example. Especially, 1, 6- hexamethylene diisocyanate can be used suitably.

As the hydrophilic compound (C) having reactivity with an isocyanate group in the present embodiment, for example, an anionic chain lengthening agent, a nonionic chain lengthening agent, a cationic chain lengthening agent, etc. can be used, and these may be used alone or in combination of two or more. and can be used. Especially, an anionic chain lengthening agent can be used suitably. As the anionic chain lengthening agent, polyhydroxy compounds having two or more hydroxyl groups in the molecule can be used, and examples thereof include polyhydroxy compounds having one or more hydrophilic groups (carboxyl groups or sulfone groups) in the molecule. can More specifically, 2,2-dimethylol lactic acid, 2,2-dimethylol propionic acid, 2,2-dimethylol butanoic acid, 2,2-dimethylol butyric acid, 2,2-dimethylol valeric acid, 1,4 -Butanediol-2-sulfonic acid etc. are mentioned. Especially, 2, 2- dimethylol butanoic acid can be used suitably. As a nonionic chain lengthening agent, an ethylene oxide compound etc. are mentioned, for example. As a cationic chain lengthening agent, N-methyldiethanolamine etc. are mentioned, for example.

The content of the hydrophilic compound (C) reactive with an isocyanate group relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C), and the short-chain diol compound (D) is preferably 1% by mass or more. It is 2 mass % or less, More preferably, it is 1.3 mass % or more and 1.9 mass % or less, More preferably, it is 1.4 mass % or more and 1.8 mass % or less. By setting it as such content, the dispersibility of the urethane prepolymer in water can be further improved, and a porous body in which fine pores are formed can be obtained. In addition, when the hydrophilic compound (C) reactive with an isocyanate group contains a hydroxyl group, the molar ratio of the hydroxyl group of the isocyanate group-reactive hydrophilic compound (C) to the isocyanate group of the polyisocyanate compound (B) is , Preferably they are 5 mol% - 8 mol%, More preferably, they are 5.5 mol% - 7.5 mol%.

The short-chain diol compound (D) having two or more hydroxyl groups in the molecule is a chain lengthening agent and can be used without particular limitation as long as it is used in the production of ordinary polyurethane. The short-chain diol compound (D) having two or more hydroxyl groups in the molecule is a compound other than the hydrophilic compound (C) having reactivity with an isocyanate group. More specifically, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3 -Methyl-1,5-pentanediol, nonanediol, octanediol, dimethylolheptane, etc. are mentioned, These can be used individually or in mixture of 2 or more types. Especially, 3-methyl-1,5-pentanediol can be used suitably. The number average molecular weight of the short-chain diol compound (D) is preferably 500 or less, more preferably 50 to 400, still more preferably 50 to 200. The number average molecular weight is measured by GPC and calculated from a value calculated in terms of polystyrene.

Here, the material constituting the polyurethane porous body in the present embodiment includes an aqueous urethane polymer. A water-based urethane polymer is obtained by dispersing a urethane prepolymer obtained by reacting a polyol compound, a polyisocyanate compound, a hydrophilic compound having reactivity with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule in water, followed by a crosslinking reaction. will be. The hydroxyl group in the polyol compound and the isocyanate group in the polyisocyanate compound react to form a urethane polymer. In the above components, by including a short-chain diol compound having two or more hydroxyl groups in the molecule, the chain length can be extended and the urethane polymer can be made high in molecular weight. By including a hydrophilic compound having reactivity with an isocyanate group in the above component, the dispersibility of the urethane prepolymer in water is improved, and fine pores can be formed in the porous body.

By using polyether polyol as the polyol compound, a urethane polymer having high flexibility is obtained. Further, by using polycaprolactone polyol as the polyol compound, a urethane polymer having high strength is obtained. By using polyether polyol and polycaprolactone polyol together as a polyol compound, a soft urethane polymer having strength capable of withstanding deformation is obtained. For this reason, a polyurethane porous body having high flexibility and extensibility can be obtained.

Thus, according to the polyurethane porous body of the present embodiment, a polyurethane porous body having high flexibility and extensibility can be provided.

The polyurethane porous body in the present embodiment is used in various applications such as absorbent rolls, rolls for OA equipment, absorbent members, seal members, bed mats, beauty or cosmetic products, abrasive sheets, air cleaner filters, artificial leather, agricultural materials, It can be suitably used for various products such as materials related to electronic device manufacturing and health and welfare products. In particular, when used for beauty or makeup tools (particularly, beauty or cosmetics pubs), it has high flexibility and extensibility, so it can improve the touch when it comes into contact with human skin.

Next, the method for producing the polyurethane porous body in the embodiment will be described. 1 is a flowchart showing an outline of a method for producing a polyurethane porous body. Referring to FIG. 1, as a first step (S10), a step of preparing raw materials including a polyol compound, a polyisocyanate compound, a hydrophilic compound reactive with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule. this is carried out It is prepared to contain at least polyether polyol and polycaprolactone polyol as polyol compounds. Specifically, a predetermined amount of the above raw material is blended into a flask or the like.

Next, as a step (S20), a step of forming a urethane prepolymer is performed. More specifically, an organic solvent is added to the flask in which the raw materials are mixed, and stirred at a temperature of about 80° C. for about 3 hours to form a urethane prepolymer. By adding the organic solvent in this way, the viscosity can be lowered at the time of formation of the urethane prepolymer. In addition, as a method for forming a urethane prepolymer by adding an organic solvent, various known methods can be used.

Examples of the organic solvent include acetone, methyl ethyl ketone, N-methylpyrrolidone, toluene, tetrahydrofuran, dioxane, N,N'-dimethylformamide, N,N'-diethylformamide, N,N'-dimethylacetamide etc. are mentioned. Especially, N,N'-dimethylformamide can be used suitably from a solubility viewpoint of a urethane prepolymer. Also, from the viewpoint of anti-environmental properties, low volatility N,N'-diethylformamide can be suitably used.

Next, as a step (S30), a step of forming a urethane prepolymer aqueous dispersion is performed. More specifically, the obtained urethane prepolymer is cooled to a temperature of 70°C to 80°C, triethylamine or the like is added as a neutralizer, and stirred for about 15 minutes. Then, the urethane prepolymer is added to the aqueous solution containing the surfactant and the antifoaming agent, and stirred for about 10 minutes with a dispersing device such as a disper mixer, homomixer or homogenizer, O / W containing the urethane prepolymer dispersed in water A type emulsion is formed. Alternatively, it may be formed by a method of emulsifying transmission by adding water to a urethane prepolymer. Then, a water-soluble polymer is added. As a result, a urethane prepolymer water dispersion comprising an O/W type emulsion containing water, a water-soluble polymer, and a urethane prepolymer is formed. In addition, a colorant, an antibacterial agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a pH adjuster, and the like may be further added. You may add these individually or in mixture of 2 or more types. The concentration of the non-volatile content of the urethane prepolymer component of the urethane prepolymer aqueous dispersion is preferably 10% by mass to 25% by mass, more preferably 12% by mass to 20% by mass, and more preferably 13% by mass to 17% by mass. . By setting it as such a range, the density of a polyurethane porous body can be made low. Here, the non-volatile matter concentration of the urethane prepolymer component of the urethane prepolymer aqueous dispersion is the ratio (mass%) of the solid content of the urethane prepolymer to the urethane prepolymer aqueous dispersion. In addition, the solid content of a urethane prepolymer is a residue obtained by removing volatile components from the urethane prepolymer.

As the surfactant, for example, anionic surfactants, nonionic surfactants, cationic surfactants and the like can be used. Examples of the anionic surfactant include alkyl ether sulfate ester salts, alkylbenzene sulfonate salts, and sulfosuccinic acid dialkyl ester salts. As the nonionic surfactant, a higher alcohol alkylene oxide adduct (polyoxyalkylene alkyl ether), a higher alcohol ethylene oxide adduct (polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether , polyoxyethylene oleyl ether, etc.), higher alcohol propylene oxide adducts, higher alcohol (ethylene oxide-propylene oxide) adducts, alkylphenol ethylene oxide adducts (polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, etc.), arylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, fatty acid polyethylene glycol esters, fatty acid amide ethylene oxide adducts, long-chain alkylamine ethylene oxide adducts, polyhydric alcohol fatty acid esters ethylene oxide Adducts, ethylene oxide adducts of fats and oils, glycerin fatty acid esters, polyglycerides, pentaerythritol fatty acid esters, sorbitol fatty acid esters (sorbitan esters), sorbitan esters, ethylene oxide adducts, sucrose fatty acid esters, alkyl ethers of polyhydric alcohols , fatty acid amides of alkanolamines, and the like. Especially, a higher alcohol alkylene oxide adduct can be used suitably. The HLB value of the surfactant in the present embodiment is preferably 10 to 15, more preferably 10 to 14, still more preferably 11 to 13, from the viewpoint of improving the water dispersibility of the urethane prepolymer.

As the water-soluble polymer, for example, cellulose ethers such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and hydroxypropyl methyl cellulose can be used. Especially, hydroxypropyl methyl cellulose can be used suitably. The blending amount of the water-soluble polymer is preferably 1.8 parts by mass or more and 3.4 parts by mass or less with respect to 100 parts by mass of the solid content of the urethane prepolymer. By setting it as such a compounding quantity, the aggregation state of the O/W type emulsion in water can be maintained favorably.

Next, as a step (S40), a step of forming an aqueous urethane polymer is performed. More specifically, to the urethane prepolymer aqueous dispersion, an amine compound is added and stirred for about 10 seconds. Then, it is poured into a mold or the like for shaping, and allowed to stand at about 40° C. for about 12 hours to cause a cross-linking reaction to obtain a molded article containing an aqueous urethane polymer. Then, as a step (S50), a step of removing moisture from the water-based urethane polymer is performed. More specifically, the obtained molded body is washed with water or the like, and hot air dried at a temperature of about 90°C to obtain a porous urethane body.

The amine compound is not particularly limited and can be used as long as it has two or more active hydrogen atoms in its molecule (two or more primary and/or secondary amino groups are contained in one molecule). Examples of the amine compound include ethylenediamine, propylenediamine, 1,3-diaminopentane, 1,5-diaminopentane, tetramethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, and 1,5 -Diamino-2-methylpentane, 3,3'-diaminodipropylamine, 3,3'-methylimino bispropylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylene hexa Min, polyethylenediamine, N,N'-bisaminopropyl-1,3-propylenediamine, N,N'-bisaminopropyl-1,4-butylenediamine, 1,2-bis(2-aminoethoxy) Ethane, 1,2-bis(3-aminopropoxy)ethane, 1,4-bis(3-aminopropoxy)butane, 2-hydroxyaminopropylamine, bis-(3-aminopropyl)ether, 1, and aliphatic polyamides such as 3-bis-(3-aminopropoxy)-2,2-dimethylpropane. Especially, ethylenediamine can be used suitably.

Here, as one of the methods for increasing the flexibility of the polyurethane porous body, it is conceivable to lower the density of the polyurethane porous body. The density of the polyurethane porous body can be lowered by increasing the proportion of water in the urethane prepolymer water dispersion and reducing the concentration of the non-volatile matter. However, if the proportion of water is increased, the cohesiveness of the O/W type emulsion is lowered, and a three-dimensional network structure cannot be formed in some cases. Therefore, in the method for producing a polyurethane porous body according to the second aspect of the present application, a water-soluble polymer that dissolves in water and has a thickening property is added to the urethane prepolymer aqueous dispersion to lower the concentration of the non-volatile matter in the urethane prepolymer aqueous dispersion. , it is possible to form a low-density polyurethane porous body.

In addition, in the method for producing a polyurethane porous body in the present embodiment, two specific types of polyol compounds are included as the polyol compound. Two specific polyol compounds are polyetherpolyols and polycaprolactonepolyols. By doing in this way, the polyurethane porous body can be made soft and easy to deform. For this reason, the flexibility and extensibility of the polyurethane porous body are improved. Thus, according to the method for producing a polyurethane porous body in the present embodiment, a polyurethane porous body having high flexibility and extensibility can be provided.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the scope of this invention is limited by description of these Examples, and is not interpreted. Incidentally, in Examples, unless otherwise specified, "parts" and "%" are based on mass.

(Example 1 to Example 3)

Based on the blending amounts shown in Table 1, each component was blended to obtain a urethane prepolymer. Also, under the compounding amounts of the components in Table 1, the content (% by mass) of each component relative to the total amount of components constituting the urethane prepolymer is shown. More specifically, as the polyol compound (A), polytetramethylene glycol (trade name "PTMG1500", manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 1500) and polycaprolactonediol (trade name "PLACCEL L220AL", manufactured by Daicel Corporation, number average Molecular weight: 2000), 3-methyl-1,5-pentanediol (trade name "MPD", manufactured by Kuraray Co., Ltd.) as a short-chain diol compound (D) having two or more hydroxyl groups in the molecule, reactive with isocyanate groups As the hydrophilic compound (C) having 2,2-dimethylolbutanoic acid (trade name "DMBA", manufactured by Nihon Kasei Co., Ltd.), as the polyisocyanate compound (B) 1,6-hexamethylene diisocyanate (trade name " HDI", manufactured by TOSOH CORPORATION) and 4,4'-diphenylmethane diisocyanate (trade name "millionate MT", manufactured by TOSOH CORPORATION), and dimethylformamide as a solvent are mixed in a three-necked round bottom flask in the proportions shown in Table 1. prepared Next, it stirred at 80 degreeC for 3 hours, and obtained the urethane prepolymer.

Next, triethylamine, a surfactant, an antifoaming agent, water-soluble cellulose ether and distilled water were blended with the urethane prepolymer obtained above based on the compounding amounts shown in Table 1 to obtain an aqueous urethane prepolymer dispersion. More specifically, the urethane prepolymer obtained above was cooled to a temperature of 70°C to 80°C, triethylamine was added as a neutralizer, and stirring was performed for 15 minutes. Next, the urethane prepolymer obtained above was mixed with a nonionic surfactant (trade name "NAROACTY CL-70", Sanyo Chemical Industries, Ltd., HLB: 11.7) and a silicone-based antifoaming agent (trade name "KS-538", Shin-Etsu Chemical Co. ., Ltd.) was added to a previously dissolved 30°C aqueous solution, and stirred for 10 minutes with a homomixer. Then, an aqueous solution in which water-soluble cellulose ether (trade name "hi METOLOSE 65 SH4000", manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in advance was added to obtain an aqueous urethane prepolymer dispersion.

To 100 parts by mass of the urethane prepolymer aqueous dispersion obtained above, 1.3 parts by mass of an aqueous solution containing 10% of ethylenediamine was added, and the mixture was stirred and mixed for 10 seconds in an environment of room temperature of 20 ± 5°C. Thereafter, the obtained mixture was poured into a mold for molding, and allowed to stand at 40° C. for 12 hours to react, thereby obtaining a molded product made of an aqueous urethane polymer. Next, the obtained molded body was washed with water and dried at 90°C to obtain a porous urethane body.

(Examples 4 to 5)

A urethane porous body was obtained in the same manner as in Example 2, except that the blending amount of water-soluble cellulose ether (trade name "hi METOLOSE 65 SH4000", manufactured by Shin-Etsu Chemical Co., Ltd.) was set to the blending amount shown in Table 2.

(Example 6)

A porous urethane body was obtained in the same manner as in Example 2, except that the solvent was changed from dimethylformamide to diethylformamide.

(Comparative Example 1)

As the polyol compound, polycarbonate diol (trade name "T-4671", manufactured by Asahi Kasei Corporation, number average molecular weight: 1000), ethylene glycol (trade name "EG", manufactured by NIPPON SHOKUBAI CO., LTD.), 2,2-dimethylol Propionic acid (trade name "DMPA", manufactured by Perstorp), 1,6-hexamethylene diisocyanate (trade name "HDI", manufactured by TOSOH CORPORATION) as a polyisocyanate compound, and dimethylformamide as a solvent were used in three round bottoms at the ratios shown in Table 2. It was prepared by blending in a flask. Next, it stirred at 80 degreeC for 3 hours, and obtained the urethane prepolymer.

The urethane prepolymer obtained above was heated at 80°C, and triethylamine was added as a neutralizer, followed by stirring for 15 minutes. Next, the urethane polymer obtained above was added to a 27°C aqueous solution in which a nonionic surfactant (trade name "ADEKA TOL TN-100", manufactured by Asahi Denka Kogyo K.K., HLB: 13.8) was dissolved in advance, followed by stirring for 2 minutes. did more Next, the urethane prepolymer to which the neutralizer and the surfactant were added was added to distilled water and stirred for 5 minutes with a homomixer to obtain an aqueous urethane prepolymer dispersion.

To 100 parts by weight of the urethane polymer aqueous dispersion obtained above, 1.5 parts by weight of ethylenediamine was added, and the mixture was stirred and mixed for 10 seconds in an environment of room temperature of 20±5°C. Thereafter, the obtained mixture was poured into a mold for molding, left to react for 12 hours in an environment of room temperature of 20±5° C., and a molded product made of an aqueous urethane polymer was obtained. Next, the obtained molded body was washed with water and dried at 80°C to obtain a porous urethane body.

The density, tensile strength, 100% modulus, and elongation of the porous urethane bodies obtained in Examples and Comparative Examples were measured according to the following methods.

(1) Density

A test piece having a size of 50 mm x 50 mm x 3 mm was cut from the obtained porous urethane body, and the mass of the test piece was measured. The density (g/cm 3 ) of the urethane porous body was calculated from the mass of the test piece.

(2) Tensile strength

Tensile strength was measured according to JIS "K" 6301. More specifically, a test piece having a size of 60 mm long × 10 mm wide × 2 mm thick was cut from the obtained urethane porous body and measured using an Autograph [Shimadzu Corporation, product number: AGS-50D]. The measurement was performed so that the tensile direction was the longitudinal direction of the test piece, and the tensile strength (N/mm 2 ) was calculated based on the following formula using the strength when the test piece broke. [Tensile strength (N/mm2)] = [Strength at break (N)]/[Cross-sectional area of test piece (mm2)]

(3) 100% modulus

100% modulus was measured according to JIS "K" 6301. More specifically, a test piece having a size of 60 mm long × 10 mm wide × 2 mm thick was cut from the obtained urethane porous body and measured using an Autograph [Shimadzu Corporation, product number: AGS-50D]. The measurement was performed so that the tensile direction was the longitudinal direction of the test piece, and the 100% modulus (N/mm 2 ) was calculated based on the following formula using the strength at 100% elongation of the test piece. [100% modulus (N/mm2)] = [strength at 100% elongation of the test piece (N)]/[cross-sectional area of the test piece (mm2)]

(4) Elongation

The elongation rate was measured according to JIS "K" 6301. More specifically, a test piece having a size of 60 mm long × 10 mm wide × 2 mm thick was cut from the obtained urethane porous body and measured using an Autograph [Shimadzu Corporation, product number: AGS-50D]. The measurement was performed with a gauge line of 20 mm so that the tensile direction was the longitudinal direction of the test piece, and the elongation rate (%) was calculated based on the following formula using the elongation when the test piece broke. [elongation rate (%)] = ([length between gauge lines at break (mm)] - [gauge line distance (mm)]) / [gauge line distance (mm)] × 100

Formulations of Examples (Examples 1 to 5) and Comparative Examples are shown in Tables 1 to 3. Table 4 shows the evaluation results of each evaluation item.

As can be seen from the evaluation results in Table 4, in Examples 1 to 6 containing polyether polyol and polycaprolactone polyol as polyol compounds, compared to Comparative Example 1 containing polyol compounds other than the above, porous urethane The 100% modulus, which is an indicator of the hardness of the sieve, is lowered and is becoming softer. Moreover, it turns out that density and tensile strength are also low in Example 1 - Example 6 similarly. In Examples 1 to 6, compared to Comparative Example 1, the elongation rate, which is an index indicating the ease of deformation of the urethane porous body, is improved, and the deformation becomes easy. From the above results, it can be said that the porous urethane bodies of Examples 1 to 6 are urethane porous bodies that have both softness and ease of deformation, and are excellent in flexibility and extensibility.

Further, in Examples 1 to 3 in which the content of the aromatic polyisocyanate in the urethane prepolymer is 9% by mass to 15% by mass, the 100% modulus is lowered as compared with Comparative Example 1, and the elongation rate is increased. Moreover, also in Example 2, Example 4, and Example 5 in which the compounding amount of water-soluble cellulose ether was changed, compared with Comparative Example 1, the 100% modulus was lowered and the elongation rate was increased. Also in Example 6 in which diethylformamide was used as the organic solvent used when forming the urethane prepolymer, the 100% modulus was lowered and the elongation rate was increased as compared with Comparative Example 1.

Thus, according to the urethane porous body of the present application, a polyurethane porous body having high flexibility and extensibility can be provided.

It is natural to understand that the embodiment disclosed this time is an example in all respects and not restrictive in any respect. The scope of the present invention is defined not by the above description, but by the claims, and it is intended that all changes within the scope and meaning equivalent to the scope of the claims are included.

The polyurethane porous body of the present application can be particularly advantageously applied in fields where it is required to provide a polyurethane porous body having high flexibility and extensibility.

Claims (6)

As a polyurethane porous body containing an aqueous urethane polymer,
The water-based urethane polymer,
A polyol compound (A) including polyether polyol and polycaprolactone polyol;
a polyisocyanate compound (B);
A hydrophilic compound (C) reactive with an isocyanate group, and
It is a reactant of a component containing a short-chain diol compound (D) having two or more hydroxyl groups in the molecule,
The content of the polyether polyol and the polycaprolactone polyol relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C), and the short-chain diol compound (D) is 50% by mass or more A polyurethane porous body that is 60% by mass or less. According to claim 1,
The polyurethane porous body, wherein the hydrophilic compound (C) having reactivity with an isocyanate group includes a polyhydroxy compound having two or more hydroxyl groups in a molecule. According to claim 1,
The polyisocyanate compound (B) includes an aromatic polyisocyanate and an aliphatic polyisocyanate. According to claim 3,
The content of the aromatic polyisocyanate relative to the total amount of the polyol compound (A), the polyisocyanate compound (B), the hydrophilic compound (C), and the short-chain diol compound (D) is 8% by mass or more and 17% by mass or less, poly Urethane porous body. According to any one of claims 1 to 4,
A polyurethane porous body wherein the mass ratio (polyether polyol/polycaprolactone polyol) of the blending amount of the polyether polyol and the blending amount of the polycaprolactone polyol is 1 or more and 4 or less. A step of preparing a raw material including a polyol compound including polyether polyol and polycaprolactone polyol, a polyisocyanate compound, a hydrophilic compound reactive with an isocyanate group, and a short-chain diol compound having two or more hydroxyl groups in a molecule;
Forming a urethane prepolymer by reacting the polyol compound, the polyisocyanate compound, the hydrophilic compound having reactivity with the isocyanate group, and the short-chain diol compound having two or more hydroxyl groups in the molecule;
The urethane prepolymer, water, and a surfactant are stirred together, and the urethane prepolymer is dispersed in water to form an O/W (Oil In Water) type emulsion, and a water-soluble polymer is further added to form water, the O/W type emulsion , And a step of forming a urethane prepolymer aqueous dispersion containing the water-soluble polymer,
A step of adding an amine compound to the urethane prepolymer aqueous dispersion and causing a crosslinking reaction to form an aqueous urethane polymer; and
A method for producing a polyurethane porous body according to claim 1, comprising a step of removing moisture from the water-based urethane polymer.

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