Microcapsule

Abstract

To provide a microcapsule having excellent marine biodegradability.SOLUTION: Microcapsules contain a core material and a wall material that coats the core material. The wall material contains polyurethane resin, and the polyurethane resin contains a reaction product of polyurethane raw materials. The polyurethane raw materials include isocyanate group terminal prepolymer and chain extender. The isocyanate group terminal prepolymer contains a reaction product of the prepolymer raw materials. The prepolymer raw materials include polyisocyanate components and polyol components. The polyol components include plant oil polyol and / or polycaprolactone polyol, as well as hydrophilic group-containing active hydrogen compounds.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to microcapsules.

Background Art

[0002] Conventionally, microcapsules have been widely used in various industrial fields (for example, perfumes, agricultural chemicals, pharmaceuticals, paints, and adhesives). Microcapsules contain a core substance and a wall material that coats the core substance. The core substance is selected according to the use of the microcapsules. Examples of the wall material include polyurethane resin.

[0003] More specifically, polyurethane having an allophanate group has been proposed as the wall material of microcapsules. Also, a method for producing microcapsules by emulsifying and dispersing an allophanate group-containing polyisocyanate and a core substance in an active hydrogen-containing dispersion medium has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, from the viewpoint of environmental properties, microcapsules that can be marine biodegraded are required.

[0006] The present invention is a microcapsule having excellent marine biodegradability.

Means for Solving the Problems

[0007] The present invention [1] relates to microcapsules containing a core substance and a wall material that coats the core substance. The wall material contains a polyurethane resin, the polyurethane resin contains a reaction product of a polyurethane raw material, the polyurethane raw material contains an isocyanate group-terminated prepolymer and a chain extender, the isocyanate group-terminated prepolymer contains a reaction product of a prepolymer raw material, the prepolymer raw material contains a polyisocyanate component and a polyol component, and the polyol component contains a vegetable oil polyol and a hydrophilic group-containing active hydrogen compound.

[0008] The present invention [2] includes the microcapsules according to [1] above, wherein the chain extender contains a polymethylene diamine having 2 to 8 carbon atoms.

[0009] The present invention [3] includes the microcapsules according to [1] or [2] above, wherein the polyurethane raw material further contains an isocyanate crosslinking agent.

[0010] The present invention [4] includes the microcapsules according to any one of [1] to [3] above, wherein the hydrophilic group-containing active hydrogen compound contains an anionic group-containing active hydrogen compound.

[0011] The present invention [5] includes the microcapsules according to any one of [1] to [4] above, wherein the content ratio of the vegetable oil polyol and / or polycaprolactone polyol is 30 to 95% by mass with respect to the total amount of the vegetable oil polyol and / or polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender.

[0012] The present invention [6] includes the microcapsules according to any one of [1] to [5] above, wherein the core substance contains a fragrance.

[0013] The present invention [7] contains the microcapsules according to any one of the above [1] to [6], having a volume average particle diameter of 1.0 to 50.0 μm.

Effects of the Invention

[0014] In the present invention, the polyol component of the prepolymer raw material contains a vegetable oil polyol and / or a polycaprolactone polyol and a hydrophilic group-containing active hydrogen compound. Therefore, the microcapsules of the present invention have excellent marine biodegradability.

Embodiments for Carrying Out the Invention

[0015] 1. Microcapsules The microcapsules include a core substance (core layer) and a wall material (shell layer) that coats the core substance. Preferably, the microcapsules consist of a core substance and a wall material that coats the core substance.

[0016] (1) Core Substance The core substance is not particularly limited and is selected according to the use of the microcapsules. Examples of the core substance include an aqueous core substance and an oily core substance, and preferably an oily core substance. Examples of the oily core substance include fragrances, agricultural chemicals, pharmaceuticals, color formers, and functional polymers. These can be used alone or in combination of two or more. Preferably, a fragrance is used as the core substance. Examples of the fragrance include animal-derived fragrances, plant-derived fragrances, and synthetic fragrances (for example, butyl acetate). These can be used alone or in combination of two or more.

[0017] The content (encapsulation amount) of the core substance in the microcapsules is appropriately set according to the purpose and use.

[0018] (2) Wall Material The wall material contains a polyurethane resin. Preferably, the wall material consists of a polyurethane resin. The polyurethane resin contains a reaction product of polyurethane raw materials. Preferably, the polyurethane resin consists of a reaction product of polyurethane raw materials. The polyurethane raw materials contain an isocyanate group-terminated prepolymer and a chain extender. The isocyanate group-terminated prepolymer contains a reaction product of prepolymer raw materials. Preferably, the isocyanate group-terminated prepolymer consists of a reaction product of prepolymer raw materials. The prepolymer raw materials contain a polyisocyanate component and a polyol component. Preferably, the prepolymer raw materials consist of a polyisocyanate component and a polyol component.

[0019] That is, a polyisocyanate component and a polyol component are contained in the prepolymer raw materials. And by the reaction of the prepolymer raw materials, an isocyanate group-terminated prepolymer is obtained as a reaction product (primary reaction product).

[0020] Also, an isocyanate group-terminated prepolymer and a chain extender are contained in the polyurethane raw materials. By the reaction of the polyurethane raw materials, a polyurethane resin is obtained as a reaction product (secondary reaction product).

[0021] And the polyurethane resin is used as the wall material of the microcapsules. More specifically, in the presence of the core material, by producing the polyurethane resin as the wall material, the core material can be coated with the wall material, and microcapsules can be obtained. Hereinafter, the method for producing microcapsules will be described in detail.

[0022] 2. Method for Producing Microcapsules In the production of microcapsules, as described above, first, the prepolymer raw materials are reacted to produce an isocyanate group-terminated prepolymer (prepolymer synthesis step). Next, the isocyanate group-terminated prepolymer and the core material are mixed (mixing step). Then, the polyurethane raw materials are reacted to obtain a polyurethane resin as the wall material and to coat the core material with the wall material (chain extension step). Hereinafter, each will be described in detail.

[0023] (1) Prepolymer synthesis step In the prepolymer synthesis step, an isocyanate group-terminated prepolymer is synthesized by reacting prepolymer raw materials. The prepolymer raw materials contain a polyisocyanate component and a polyol component. The prepolymer raw materials preferably consist of a polyisocyanate component and a polyol component.

[0024] [Polyisocyanate component] The polyisocyanate component is a component containing a compound having two or more isocyanate groups in the molecule (hereinafter referred to as a polyisocyanate compound). Examples of the polyisocyanate compound include polyisocyanate monomers and polyisocyanate derivatives.

[0025] Examples of the polyisocyanate monomer include aliphatic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0026] Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 1,2-propanediisocyanate, 1,2-butanediisocyanate, 2,3-butanediisocyanate, 1,3-butanediisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanatemethyl caproate, and lysine diisocyanate. These can be used alone or in combination of two or more.

[0027] In addition, the aliphatic polyisocyanate includes alicyclic polyisocyanate. Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), methylene bis(cyclohexyl isocyanate) (hydrogenated diphenylmethane diisocyanate, H 12 MDI), and bis(isocyanatomethyl)cyclohexane (hydrogenated xylylene diisocyanate, H 6 XDI). Examples of methylene bis(cyclohexyl isocyanate) include 4,4'-methylene bis(cyclohexyl isocyanate), 2,4'-methylene bis(cyclohexyl isocyanate), and 2,2'-methylene bis(cyclohexyl isocyanate). Examples of bis(isocyanatomethyl)cyclohexane include 1,2-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-bis(isocyanatomethyl)cyclohexane. These can be used alone or in combination of two or more.

[0028] Examples of the aromatic polyisocyanate include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), toluidine diisocyanate (TODI), paraphenylene diisocyanate, and naphthalene diisocyanate (NDI).

[0029] Examples of the araliphatic polyisocyanate include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). Examples of xylylene diisocyanate include 1,2-xylylene diisocyanate (o-XDI), 1,3-xylylene diisocyanate (m-XDI), and 1,4-xylylene diisocyanate (p-XDI).

[0030] Examples of the polyisocyanate derivative include modified products obtained by modifying the above polyisocyanate monomer by a known method. Examples of the polyisocyanate derivative include multimers, isocyanurate-modified products, allophanate-modified products, polyol-modified products, biuret-modified products, urea-modified products, oxadiazinetrione-modified products, and carbodiimide-modified products. Further, polymethylene polyphenylene polyisocyanate is also included as the polyisocyanate derivative.

[0031] The polyisocyanate component can be used alone or in combination of two or more. Preferably, the polyisocyanate monomer is mentioned as the polyisocyanate component.

[0032] From the viewpoint of improving biodegradability, more preferably, aliphatic polyisocyanates are included, still more preferably, linear aliphatic polyisocyanates are included, and particularly preferably, pentamethylene diisocyanate is included. That is, from the viewpoint of improving biodegradability, the polyisocyanate component more preferably contains an aliphatic polyisocyanate, still more preferably contains a linear aliphatic polyisocyanate, and particularly preferably contains pentamethylene diisocyanate.

[0033] From the viewpoint of improving barrier properties, more preferably, aromatic polyisocyanates and araliphatic polyisocyanates are included, still more preferably, araliphatic polyisocyanates are included, and particularly preferably, xylylene diisocyanate is included. That is, from the viewpoint of improving barrier properties, the polyisocyanate component more preferably contains an aromatic polyisocyanate and / or an araliphatic polyisocyanate, still more preferably contains an araliphatic polyisocyanate, and particularly preferably contains xylylene diisocyanate.

[0034] The average isocyanate functionality of the polyisocyanate component is, for example, 2 to 6, preferably 2 to 4, more preferably 2 to 3, and particularly preferably 2. That is, as the polyisocyanate component, diisocyanate is particularly preferably mentioned.

[0035] As will be described later, the content ratio of the polyisocyanate component is set based on the equivalent ratio of the isocyanate group to the hydroxyl group (isocyanate group / hydroxyl group) in the polyisocyanate component with respect to the hydroxyl group in the polyol component in the prepolymerization reaction.

[0036] [Polyol component] The polyol component contains a vegetable oil polyol and / or a polycaprolactone polyol, and a hydrophilic group-containing active hydrogen compound.

[0037] [Vegetable oil polyol and / or polycaprolactone polyol] Examples of the vegetable oil polyol include vegetable oils and polyols containing plant-derived fatty acids.

[0038] Examples of the vegetable oil include castor oil, soybean oil, palm oil, sesame oil, rapeseed oil, coconut oil, and hydrogenated products thereof, and preferably castor oil. The vegetable oils can be used alone or in combination of two or more.

[0039] Examples of the polyol containing plant-derived fatty acids include polyester polyols obtained by subjecting plant-derived fatty acids to a condensation reaction using a low molecular weight polyol (described later) as an initiator, ester-modified polyols obtained by reacting plant-derived fatty acids with polyoxypropylene polyols, and polyester polyols obtained by subjecting vegetable oils to a condensation reaction with plant-derived fatty acids.

[0040] Incidentally, plant-derived fatty acids are fatty acids obtained from plant raw materials (including the above-described vegetable oils), and can be obtained, for example, by hydrolyzing the above-described vegetable oils. As the vegetable oil, its hydrogenated product (i.e., hardened vegetable oil) can also be used. That is, as the plant-derived fatty acid, its hydrogenated product (i.e., hardened fatty acid) can also be used.

[0041] The method for hydrolyzing vegetable oil is not particularly limited, and known methods are used.

[0042] Moreover, the plant-derived fatty acid preferably contains a fatty acid containing a hydroxyl group (hereinafter referred to as a hydroxyl group-containing fatty acid). When the plant-derived fatty acid does not contain a hydroxyl group-containing fatty acid, after hydrolyzing the vegetable oil, a hydroxyl group can be added to the obtained unsaturated fatty acid by methods such as air oxidation, epoxidation, and hydroformylation to obtain a hydroxyl group-containing fatty acid.

[0043] Examples of the hydroxyl group-containing fatty acid include hydroxyl group-containing monocarboxylic acids such as ricinoleic acid, 12-hydroxystearic acid, and lactic acid, and hydroxyl group-containing dicarboxylic acids such as malic acid. Preferably, hydroxyl group-containing monocarboxylic acids are mentioned, and more preferably, ricinoleic acid is mentioned. The hydroxyl group-containing fatty acid can be used alone or in combination of two or more. The hydroxyl group-containing fatty acid contained in the plant-derived fatty acid is appropriately selected according to the type of vegetable oil used.

[0044] In the following description, a polyol containing castor oil and fatty acids derived from castor oil (including its hydrogenated product) will be referred to as castor oil polyol. That is, examples of castor oil polyol include polyols containing castor oil and fatty acids derived from castor oil. The fatty acid derived from castor oil is a fatty acid obtained from castor oil and can be obtained, for example, by hydrolyzing castor oil. The fatty acid derived from castor oil may be referred to as castor oil fatty acid.

[0045] Examples of the polyol containing fatty acids derived from castor oil include, for example, ester-modified castor oil polyol obtained by reacting castor oil fatty acid with polyoxypropylene polyol, castor oil polyester polyol obtained by subjecting a hydroxycarboxylic acid such as castor oil fatty acid or hydrogenated castor oil fatty acid to a condensation reaction using a low molecular weight polyol (described later) as an initiator, and castor oil polyester polyol obtained by subjecting castor oil to a condensation reaction with a hydroxycarboxylic acid such as castor oil fatty acid or hydrogenated castor oil fatty acid.

[0046] The fatty acids derived from castor oil mainly contain ricinoleic acid, which is a hydroxyl group-containing fatty acid.

[0047] In addition, as fatty acids other than ricinoleic acid, the fatty acids derived from castor oil contain, for example, unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and saturated fatty acids such as palmitic acid and stearic acid.

[0048] The content of each fatty acid in the fatty acids derived from castor oil is, for example, 87% to 90% by mass of ricinoleic acid, 2.5% to 4% by mass of oleic acid, 4% to 5% by mass of linoleic acid, 0.5% to 1.5% by mass of linolenic acid, 0.5% to 1.5% by mass of palmitic acid, and 0.5% to 1.5% by mass of stearic acid with respect to the total amount of the fatty acids derived from castor oil.

[0049] When hydrogenated castor oil is used as the vegetable oil, the hydrogenated castor oil fatty acid obtained by its hydrolysis mainly contains 12-hydroxy stearic acid, which is a hydroxyl group-containing fatty acid.

[0050] The vegetable oil polyol is produced by a known method. Also, the vegetable oil polyol can be obtained as a commercial product.

[0051] The number average molecular weight (or molecular weight) of the vegetable oil polyol is, for example, 200 to 10,000, preferably 300 to 5,000, more preferably 500 to 3,000, still more preferably 750 to 2,500.

[0052] The hydroxyl value (OH value) of the vegetable oil polyol is, for example, 20 mgKOH / g to 500 mgKOH / g, preferably 25 mgKOH / g to 300 mgKOH / g, more preferably 30 mgKOH / g to 200 mgKOH / g, still more preferably 35 mgKOH / g to 100 mgKOH / g, and particularly preferably 40 mgKOH / g to 80 mgKOH / g.

[0053] The hydroxyl value (OH value) of the vegetable oil polyol is, for example, 20 mgKOH / g or more, preferably 25 mgKOH / g or more, more preferably 30 mgKOH / g or more, still more preferably 35 mgKOH / g or more, and particularly preferably 40 mgKOH / g or more. Also, for example, it is 500 mgKOH / g or less, preferably 300 mgKOH / g or less, more preferably 200 mgKOH / g or less, still more preferably 100 mgKOH / g or less, and particularly preferably 80 mgKOH / g or less.

[0054] The average number of hydroxyl groups of the vegetable oil polyol is, for example, 1.6 to 6.0, preferably 1.7 to 4.0, more preferably 1.8 to 2.5, still more preferably 1.8 to 2.2.

[0055] The average number of hydroxyl groups of the vegetable oil polyol is, for example, 1.6 or more, preferably 1.7 or more, more preferably 1.8 or more. Also, for example, it is 6.0 or less, preferably 4.0 or less, more preferably 2.5 or less, still more preferably 2.2 or less.

[0056] The polycaprolactone polyol is a ring-opening polymer of lactone using a low molecular weight polyol (described later) as an initiator.

[0057] Examples of lactones include β-lactone, γ-lactone, σ-lactone, and ε-lactone. These can be used alone or in combination of two or more.

[0058] The polycaprolactone polyol is produced by a known method. Also, the polycaprolactone polyol can be obtained as a commercially available product.

[0059] The number average molecular weight (or molecular weight) of the polycaprolactone polyol is, for example, 200 to 10,000, preferably 300 to 5,000, more preferably 500 to 3,000, still more preferably 750 to 2,500.

[0060] The hydroxyl value (OH value) of the polycaprolactone polyol is, for example, 20 mgKOH / g to 500 mgKOH / g, preferably 25 mgKOH / g to 300 mgKOH / g, more preferably 30 mgKOH / g to 200 mgKOH / g, still more preferably 35 mgKOH / g to 100 mgKOH / g, and particularly preferably 40 mgKOH / g to 80 mgKOH / g.

[0061] The hydroxyl value (OH value) of the polycaprolactone polyol is, for example, 20 mgKOH / g or more, preferably 25 mgKOH / g or more, more preferably 30 mgKOH / g or more, still more preferably 35 mgKOH / g or more, and particularly preferably 40 mgKOH / g or more. Also, for example, it is 500 mgKOH / g or less, preferably 300 mgKOH / g or less, more preferably 200 mgKOH / g or less, still more preferably 100 mgKOH / g or less, and particularly preferably 80 mgKOH / g or less.

[0062] The average number of hydroxyl groups of the polycaprolactone polyol is, for example, 1.6 to 3.5, preferably 1.7 to 3.0, more preferably 1.8 to 2.5, still more preferably 1.8 to 2.2.

[0063] The average number of hydroxyl groups of the polycaprolactone polyol is, for example, 1.6 or more, preferably 1.7 or more, more preferably 1.8 or more, and, for example, 3.5 or less, preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.2 or less.

[0064] The vegetable oil polyol and the polycaprolactone polyol may be used alone or in combination of two or more. Preferably, the vegetable oil polyol is used alone, and the polycaprolactone polyol is used alone.

[0065] From the viewpoint of marine biodegradability, more preferably, the vegetable oil polyol is mentioned, still more preferably, an ester-modified polyol obtained by reacting a plant-derived fatty acid and a polyoxypropylene polyol is mentioned, and particularly preferably, an ester-modified polyol obtained by reacting a castor oil-derived fatty acid and a polyoxypropylene polyol is mentioned.

[0066] The content ratio of the vegetable oil polyol and / or the polycaprolactone polyol is, for example, 40 to 99% by mass, preferably 60 to 98% by mass, more preferably 80 to 97% by mass, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound described later.

[0067] More specifically, from the viewpoint of marine biodegradability, the content ratio of the vegetable oil polyol and / or the polycaprolactone polyol is, for example, 40% by mass or more, preferably 60% by mass or more, more preferably 80% by mass or more, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound described later.

[0068] Also, from the perspective of marine biodegradability, the content ratio of the vegetable oil polyol and / or polycaprolactone polyol is, for example, 99% by mass or less, preferably 98% by mass or less, more preferably 97% by mass or less, based on the total amount of the vegetable oil polyol and / or polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound described later.

[0069] Also, the content ratio of the vegetable oil polyol and / or polycaprolactone polyol is, for example, 30 to 95% by mass, preferably 40 to 90% by mass, more preferably 50 to 80% by mass, based on the total amount of the vegetable oil polyol and / or polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound described later, and the chain extender described later.

[0070] More specifically, from the perspective of environmental properties, the content ratio of the vegetable oil polyol and / or polycaprolactone polyol is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, based on the total amount of the vegetable oil polyol and / or polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound described later, and the chain extender described later.

[0071] Also, from the perspective of marine biodegradability, the content ratio of the vegetable oil polyol and / or polycaprolactone polyol is, for example, 95% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, based on the total amount of the vegetable oil polyol and / or polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound described later, and the chain extender described later.

[0072] [Hydrophilic Group-Containing Active Hydrogen Compound] The hydrophilic group-containing active hydrogen compound is an organic compound having both an active hydrogen group and a hydrophilic group. Examples of the active hydrogen group include, for example, a hydroxyl group and an amino group, and preferably, a hydroxyl group. Examples of the hydrophilic group include, for example, an anionic group and a polyoxyethylene group, and preferably, an anionic group. In other words, the polyurethane resin has, as a hydrophilic group, an anionic group and / or a polyoxyethylene group, and preferably, an anionic group.

[0073] Examples of the hydrophilic group-containing active hydrogen compound include, for example, an ionic group-containing active hydrogen compound and a nonionic group-containing active hydrogen compound.

[0074] Examples of the ionic group-containing active hydrogen compound include, for example, an anionic group-containing active hydrogen compound and a cationic group-containing active hydrogen compound, and preferably, an anionic group-containing active hydrogen compound.

[0075] The anionic group-containing active hydrogen compound is, for example, an organic compound having one or more anionic groups and two or more active hydrogen groups in one molecule. Examples of the anionic group include, for example, a carboxy group (carboxylic acid group) and a sulfo group (sulfonic acid group), and preferably, a carboxy group.

[0076] As the anionic group-containing active hydrogen compound, preferably, an organic compound having one carboxy group and two or more hydroxyl groups in one molecule can be mentioned, more preferably, an organic compound having one carboxy group and two hydroxyl groups in one molecule can be mentioned. Examples of the organic compound having one carboxy group and two hydroxyl groups in one molecule include carboxy group-containing diols. Examples of the carboxy group-containing diol include dihydroxyalkanoic acids. Examples of the dihydroxyalkanoic acid include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (also known as dimethylolpropionic acid, DMPA), 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. These can be used alone or in combination of two or more. From the viewpoint of water dispersibility, preferably, 2,2-dimethylolpropionic acid can be mentioned.

[0077] In the nonionic group-containing active hydrogen compound, examples of the nonionic group include, for example, a polyoxyethylene group. Examples of the nonionic group-containing active hydrogen compound include polyoxyethylene group-containing active hydrogen compounds. Examples of the polyoxyethylene group-containing active hydrogen compound include a monoalcohol containing a polyoxyethylene group in the main chain and a polyol containing a polyoxyethylene group in the side chain. That is, the polyoxyethylene group-containing active hydrogen compound does not contain a polyol containing a polyoxyethylene group in the main chain. Therefore, the polyoxyethylene group-containing active hydrogen compound is distinguished from the low molecular weight polyol (described later) and the high molecular weight polyol (described later).

[0078] More specifically, examples of the polyoxyethylene group-containing active hydrogen compound include, for example, one-end-blocked polyoxyethylene glycol and a diol containing a polyoxyethylene side chain.

[0079] Examples of the mono-end-capped polyoxyethylene glycol include alkoxyethylene glycol (monoalkoxypolyoxyethylene glycol) mono-end-capped with an alkyl group. Examples of the alkyl group include alkyl groups having 1 to 20 carbon atoms, preferably alkyl groups having 1 to 10 carbon atoms, more preferably alkyl groups having 1 to 4 carbon atoms, still more preferably alkyl groups having 1 to 2 carbon atoms, and particularly preferably methyl and ethyl groups. More specific examples of the mono-end-capped polyoxyethylene glycol include methoxypolyoxyethylene glycol (MeOPEG) and ethoxypolyoxyethylene glycol, with methoxypolyoxyethylene glycol being preferred. The number average molecular weight (polystyrene-equivalent molecular weight measured by GPC) of the mono-end-capped polyoxyethylene glycol is, for example, 200 to 5000, preferably 400 to 2000.

[0080] The polyoxyethylene side chain-containing diol is a diol having a polyoxyethylene group in the side chain. The polyoxyethylene side chain-containing diol is produced by a known method. For example, a polyoxyethylene chain-containing monoisocyanate can be obtained by reacting a known diisocyanate with the above mono-end-capped polyoxyethylene glycol. Further, a polyoxyethylene side chain-containing diol can be obtained by reacting the polyoxyethylene chain-containing monoisocyanate with a dialkanolamine. The number average molecular weight (polystyrene-equivalent molecular weight measured by GPC) of the polyoxyethylene side chain-containing diol is, for example, 200 to 5000, preferably 400 to 2000.

[0081] These can be used alone or in combination of two or more. Preferred examples of the polyoxyethylene group-containing active hydrogen compound include mono-end-capped polyoxyethylene glycol.

[0082] The hydrophilic group-containing active hydrogen compound can be used alone or in combination of two or more kinds. That is, as the hydrophilic group-containing active hydrogen compound, an anionic group-containing active hydrogen compound may be used alone, a polyoxyethylene group-containing active hydrogen compound may be used alone, or an anionic group-containing active hydrogen compound and a polyoxyethylene group-containing active hydrogen compound may be used in combination. From the viewpoint of the productivity of microcapsules, as the hydrophilic group-containing active hydrogen compound, preferably, an anionic group-containing active hydrogen compound is mentioned.

[0083] The content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 1 to 60% by mass, preferably 2 to 40% by mass, more preferably 3 to 20% by mass, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound.

[0084] More specifically, from the viewpoint of the productivity of microcapsules, the content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 1% by mass or more, preferably 2% by mass or more, more preferably 3% by mass or more, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound.

[0085] Also, from the viewpoint of marine biodegradability, the content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 60% by mass or less, preferably 40% by mass or less, more preferably 20% by mass or less, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol and the hydrophilic group-containing active hydrogen compound.

[0086] Also, the content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 1 to 30% by mass, preferably 2 to 20% by mass, more preferably 3 to 10% by mass, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender described later.

[0087] More specifically, from the perspective of environmental properties, the content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 1% by mass or more, preferably 2% by mass or more, more preferably 3% by mass or more, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender described later.

[0088] Also, from the perspective of marine biodegradability, the content ratio of the hydrophilic group-containing active hydrogen compound is, for example, 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender described later.

[0089] [Other polyols] The polyol component can contain other polyols. Other polyols are polyols excluding the vegetable oil polyol and the polycaprolactone polyol, and the hydrophilic group-containing active hydrogen compound.

[0090] Examples of other polyols include, for example, low molecular weight polyols and high molecular weight polyols (excluding the vegetable oil polyol and the polycaprolactone polyol, and the hydrophilic group-containing active hydrogen compound).

[0091] The low molecular weight polyol is an organic compound having two or more hydroxyl groups in the molecule and a relatively low molecular weight. The relatively low molecular weight means a number average molecular weight of less than 400, preferably 300 or less.

[0092] Note that the low molecular weight polyol does not have the above ionic group. That is, the low molecular weight polyol is distinguished from the ionic group-containing active hydrogen compound. Also, when the low molecular weight polyol has an oxyethylene group, the oxyethylene group is contained in the main chain of the low molecular weight polyol and not in the side chain. That is, the low molecular weight polyol is distinguished from the oxyethylene group-containing active hydrogen compound.

[0093] Examples of the low molecular weight polyol include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of the dihydric alcohol include dihydric alcohols having 1 to 20 carbon atoms. Examples of the dihydric alcohol having 1 to 20 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol (NPG), diethylene glycol, triethylene glycol, dipropylene glycol, bisphenol A, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol (1,4-CHDM), and isosorbide. Examples of the trihydric alcohol include trihydric alcohols having 1 to 20 carbon atoms. Examples of the trihydric alcohol having 1 to 20 carbon atoms include glycerin and trimethylolpropane (TMP). Examples of the tetrahydric or higher alcohol include pentaerythritol, diglycerin, sorbitol, and sucrose. Further, examples of the low molecular weight polyol also include a polymer obtained by addition polymerization of an alkylene (C2-3) oxide to a di- or trihydric alcohol so that the number average molecular weight is less than 400. These low molecular weight polyols can be used alone or in combination of two or more.

[0094] From the viewpoint of marine biodegradability, the content ratio of the low molecular weight polyol is, for example, 0 to 50% by mass, preferably 0 to 10% by mass, and particularly preferably 0% by mass, based on the total amount of the polyol component. That is, from the viewpoint of marine biodegradability, the polyol component particularly preferably does not contain a low molecular weight polyol.

[0095] The high molecular weight polyol (excluding vegetable oil polyol and polycaprolactone polyol and a hydrophilic group-containing active hydrogen compound) is an organic compound having two or more hydroxyl groups in the molecule and having a relatively high molecular weight. The relatively high molecular weight means a number average molecular weight of 400 or more, preferably 500 or more. The number average molecular weight indicates the number average molecular weight in terms of polystyrene by GPC measurement (the same applies hereinafter).

[0096] In addition, the high molecular weight polyol does not have the above ionic group. That is, the high molecular weight polyol is distinguished from the ionic group-containing active hydrogen compound. Further, when the high molecular weight polyol has an oxyethylene group, the oxyethylene group is contained in the main chain of the high molecular weight polyol and not in the side chain. That is, the high molecular weight polyol is distinguished from the oxyethylene group-containing active hydrogen compound.

[0097] Examples of the high molecular weight polyol include polyether polyol, polyester polyol (excluding vegetable oil polyol and polycaprolactone polyol and hydrophilic group-containing active hydrogen compound), polycarbonate polyol, polyurethane polyol, epoxy polyol, polyolefin polyol, acrylic polyol, vinyl monomer-modified polyol, and lignin. These may be used alone or in combination of two or more.

[0098] From the viewpoint of marine biodegradability, the content ratio of the high molecular weight polyol is, for example, 0 to 20% by mass, preferably 0 to 10% by mass, and particularly preferably 0% by mass, based on the total amount of the polyol component. That is, from the viewpoint of marine biodegradability, the polyol component particularly preferably does not contain a high molecular weight polyol.

[0099] That is, the polyol component preferably consists of a vegetable oil polyol and / or a polycaprolactone polyol and a hydrophilic group-containing active hydrogen compound.

[0100] [Prepolymerization reaction] In the reaction between the polyisocyanate component and the polyol component (prepolymerization reaction), for example, bulk polymerization or solution polymerization is employed. In bulk polymerization, the above polyisocyanate component and the above polyol component are blended and reacted at a predetermined equivalent ratio in the absence of a solvent under a nitrogen atmosphere. In solution polymerization, the above polyisocyanate component and the above polyol component are blended and reacted at a predetermined equivalent ratio in an organic solvent under a nitrogen atmosphere. Preferably, solution polymerization is employed.

[0101] Examples of the organic solvent include solvents that are inert to isocyanate groups. Examples of the organic solvent include acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, hexane, toluene, and acetonitrile. These can be used alone or in combination of two or more. Preferably, ethyl acetate is mentioned.

[0102] In the prepolymerization reaction, the above polyisocyanate component and the above polyol component may react all at once or sequentially. More specifically, for example, the polyisocyanate component, the vegetable oil polyol and / or the polycaprolactone polyol, and the hydrophilic group-containing active hydrogen compound may be reacted all at once. Also, for example, first, the polyisocyanate component may be reacted with the vegetable oil polyol and / or the polycaprolactone polyol, and then the reaction product thereof may be reacted with the hydrophilic group-containing active hydrogen compound. Also, for example, first, the polyisocyanate component may be reacted with the hydrophilic group-containing active hydrogen compound, and then the reaction product thereof may be reacted with the vegetable oil polyol and / or the polycaprolactone polyol.

[0103] Preferably, first, the polyisocyanate component is reacted with the vegetable oil polyol and / or the polycaprolactone polyol, and then the reaction product thereof is reacted with the hydrophilic group-containing active hydrogen compound.

[0104] In the prepolymerization reaction, the equivalent ratio of isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component (isocyanate groups / hydroxyl groups) exceeds, for example, 1, preferably 1.1 or more. Also, the equivalent ratio of isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component (isocyanate groups / active hydrogen groups) is, for example, 20 or less, preferably 10 or less.

[0105] In the prepolymerization reaction, the reaction temperature is, for example, 20 to 80°C. The reaction time is, for example, 1 to 20 hours. Also, a catalyst can be added as needed. Examples of the catalyst include amine-based catalysts and organometallic catalysts. These can be used alone or in combination of two or more. Note that the addition amount of the catalyst is appropriately set according to the purpose and application.

[0106] Also, in the prepolymerization reaction, the polymerization is continued until the isocyanate group concentration of the reaction product liquid reaches a predetermined value. The isocyanate group concentration is, for example, 1 to 60% by mass, preferably 3 to 30% by mass.

[0107] Thereafter, if necessary, the unreacted polyisocyanate component is removed from the reaction product liquid by a known removal method. Examples of the removal method include distillation and extraction. Thereby, an isocyanate group-terminated prepolymer is obtained. More specifically, a solution of the isocyanate group-terminated prepolymer in the above organic solvent (organic solvent solution) is obtained.

[0108] The average number of isocyanate groups of the isocyanate group-terminated prepolymer is, for example, 1.5 or more, preferably 1.9 or more, more preferably 2.0 or more. Also, the average number of isocyanate groups of the isocyanate group-terminated prepolymer is, for example, 3.0 or less, preferably 2.5 or less.

[0109] (2) Mixing step Next, in this method, the isocyanate group-terminated prepolymer and the core material are mixed (mixing step).

[0110] More specifically, in this method, the above-mentioned core substance is added to and mixed with the solution of the isocyanate group-terminated prepolymer. The core substance may be solid or liquid. Preferably, the core substance is liquid.

[0111] The addition amount of the core substance is appropriately set according to the use of the microcapsules. For example, based on 100 parts by mass of the solid content of the isocyanate group-terminated prepolymer, the amount of the core substance is, for example, 10 to 1000 parts by mass, preferably 100 to 500 parts by mass.

[0112] Then, a mixed solution is obtained by mixing the solution of the isocyanate group-terminated prepolymer and the core substance by an appropriate method. The mixing conditions are not particularly limited. Conditions under which the solution of the isocyanate group-terminated prepolymer and the core substance can be uniformly mixed are appropriately set.

[0113] (3) Neutralization step If necessary, in this method, the isocyanate group-terminated prepolymer is neutralized (neutralization step). Preferably, the isocyanate group-terminated prepolymer is neutralized after the mixing step and before the chain extension step (described later).

[0114] More specifically, when the polyol component of the prepolymer raw material contains an ionic group-containing active hydrogen compound as a hydrophilic group-containing active hydrogen compound, the above-mentioned isocyanate group-terminated prepolymer has an ionic group. Therefore, preferably, the isocyanate group-terminated prepolymer is neutralized with a neutralizing agent to form a salt of the ionic group.

[0115] The neutralizing agent is appropriately selected according to the type of ionic group. For example, when the ionic group is an anionic group, examples of the neutralizing agent include conventional bases. Specific examples of the base include organic bases and inorganic bases. Note that the base refers to a Lewis base. An organic base is a Lewis base containing an organic component. Examples of the organic base include tertiary amines and secondary amines. Examples of the tertiary amine include trialkylamines and alkanolamines. Examples of the trialkylamine include trialkylamines having 1 to 4 carbon atoms. Such trialkylamines include, for example, trimethylamine (TMA) and triethylamine (TEA). Examples of the alkanolamine include dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. Examples of the secondary amine include heterocyclic amines. Examples of the heterocyclic amine include morpholine. These organic bases can be used alone or in combination of two or more. An inorganic base is a Lewis base composed of an inorganic component. Examples of the inorganic base include ammonia, compounds containing an alkali metal, and compounds containing an alkaline earth metal. Examples of the compounds containing an alkali metal include alkali metal hydroxides, alkali metal carbonates, and alkali metal hydrogen carbonates. Examples of the alkali metal hydroxide include lithium hydroxide (LiOH), sodium hydroxide (NaOH), and potassium hydroxide (KOH). Examples of the alkali metal carbonate include sodium carbonate and potassium carbonate. Examples of the alkali metal hydrogen carbonate include sodium hydrogen carbonate and potassium hydrogen carbonate. Examples of the compounds containing an alkaline earth metal include alkaline earth metal hydroxides and alkaline earth metal carbonates. Examples of the alkaline earth metal hydroxide include magnesium hydroxide and calcium hydroxide. Examples of the alkaline earth metal carbonate include magnesium carbonate and calcium carbonate. Further, the inorganic base may be a hydrate. These inorganic bases can be used alone or in combination of two or more.These neutralizing agents can be used alone or in combination of two or more kinds.

[0116] The method for neutralizing the isocyanate group-terminated prepolymer is not particularly limited. For example, a neutralizing agent is added to the isocyanate group-terminated prepolymer. The addition amount of the neutralizing agent is, for example, 0.4 to 1.2 equivalents, preferably 0.6 to 1.0 equivalents, per 1 equivalent of the anionic group in the isocyanate group-terminated prepolymer.

[0117] (4) Chain extension step Next, in this method, the polyurethane raw materials are reacted to obtain a polyurethane resin. The polyurethane raw materials contain the above-mentioned isocyanate group-terminated prepolymer and a chain extender.

[0118] [Chain extender] Examples of the chain extender include compounds having two or more active hydrogen groups (amino group and / or hydroxyl group) in the molecule. Examples of the chain extender include polyamines, amino alcohols, and the above-mentioned low molecular weight polyols.

[0119] Examples of the polyamine include aromatic polyamine, araliphatic polyamine, alicyclic polyamine, aliphatic polyamine, and polyamine containing a polyoxyethylene group. Examples of the aromatic polyamine include 4,4'-diphenylmethanediamine and tolylenediamine. Examples of the araliphatic polyamine include m-xylylenediamine (m-XDA) and p-xylylenediamine (p-XDA). Examples of the alicyclic polyamine include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (also known as isophoronediamine, IPDA), 4,4'-dicyclohexylmethanediamine, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,4-cyclohexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis-(4-aminocyclohexyl)methane, diaminocyclohexane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,3-bis(aminomethyl)cyclohexane (1,3-H 6 XDA), and 1,4-bis(aminomethyl)cyclohexane (1,4-H 6Examples of the aliphatic polyamine include polymethylenediamine having 1 to 10 carbon atoms. Examples of the polymethylenediamine having 1 to 10 carbon atoms include ethylenediamine (dimethylenediamine), 1,3-propanediamine (trimethylenediamine), 1,4-butanediamine (tetramethylenediamine), 1,5-pentanediamine (pentamethylenediamine), 1,6-hexanediamine (hexamethylenediamine), 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine. In addition to the above, examples of the aliphatic polyamine include 1,2-propanediamine (propylenediamine), hydrazine, hydrazine hydrate, diethylenetriamine (DETA), triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane. Examples of the polyamine containing a polyoxyethylene group include polyoxyalkylene ether diamine. Examples of the polyoxyalkylene ether diamine include polyoxyethylene ether diamine. These can be used alone or in combination of two or more.

[0120] Examples of the amino alcohol include 2-((2-aminoethyl)amino)ethanol (AEA) and 2-((2-aminoethyl)amino)-1-methylpropanol. Preferably, 2-((2-aminoethyl)amino)ethanol (AEA) is included. These can be used alone or in combination of two or more.

[0121] Examples of the low molecular weight polyol include the low molecular weight polyols described above.

[0122] In addition, examples of the chain extender include a compound having an alkoxysilyl group (hereinafter referred to as an alkoxysilyl compound). That is, the chain extender can contain an alkoxysilyl compound. Examples of the alkoxysilyl compound include an amino group-containing alkoxysilyl compound.

[0123] Examples of the amino group-containing alkoxysilyl compound include alkoxysilyl compounds having a primary amino group and no secondary amino group. Examples of the alkoxysilyl compound having a primary amino group and no secondary amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. These can be used alone or in combination of two or more.

[0124] In addition, examples of the amino group-containing alkoxysilyl compound include alkoxysilyl compounds having a primary amino group and a secondary amino group. Examples of the alkoxysilyl compound having a primary amino group and a secondary amino group include N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane. These can be used alone or in combination of two or more.

[0125] Preferred examples of the alkoxysilyl compound include alkoxysilyl compounds having a primary amino group and a secondary amino group. More preferred examples include N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane. Even more preferred is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

[0126] The chain extender can be used alone or in combination of two or more kinds. From the viewpoint of marine biodegradability, the chain extender is preferably a polyamine, more preferably an aliphatic polyamine, still more preferably a polymethylene diamine having 1 to 10 carbon atoms and hydrazine hydrate, still more preferably a polymethylene diamine having 1 to 10 carbon atoms, still more preferably a polymethylene diamine having 2 to 8 carbon atoms, still more preferably a polymethylene diamine having 4 to 6 carbon atoms, and particularly preferably a polymethylene diamine having 6 carbon atoms (hexamethylene diamine).

[0127] As described later, the content ratio of the chain extender is set based on the equivalent ratio of the active hydrogen group of the chain extender to the isocyanate group of the isocyanate group-terminated prepolymer (active hydrogen group / isocyanate group).

[0128] Further, the content ratio of the chain extender is, for example, 5 to 70% by mass, preferably 10 to 60% by mass, more preferably 20 to 50% by mass, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender.

[0129] More specifically, from the viewpoint of environmental properties, the content ratio of the chain extender is, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender.

[0130] Further, from the viewpoint of marine biodegradability, the content ratio of the chain extender is, for example, 70% by mass or less, preferably 60% by mass or less, more preferably 50% by mass or less, based on the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender.

[0131] [Chain extension reaction] In this step, in the presence of the above core material, an isocyanate group-terminated prepolymer and a chain extender are reacted with each other.

[0132] More specifically, an isocyanate group-terminated prepolymer (primary reaction product) and a chain extender are reacted with each other to obtain a polyurethane resin (secondary reaction product). For example, by reacting an isocyanate group-terminated prepolymer and a chain extender in water, a polyurethane resin is produced and water-dispersed.

[0133] Also, by reacting an isocyanate group-terminated prepolymer and a chain extender in water, a polyurethane resin is formed on the surface of the droplets of the core material. That is, the core material is coated with a wall material containing the polyurethane resin. As a result, microcapsules are produced and water-dispersed.

[0134] The method of reacting an isocyanate group-terminated prepolymer and a chain extender in water is not particularly limited. For example, first, the core material and the isocyanate group-terminated prepolymer are emulsified and dispersed in water.

[0135] The method of emulsifying and dispersing the core material and the isocyanate group-terminated prepolymer is not particularly limited. For example, a mixed solution of the core material and the isocyanate group-terminated prepolymer is added to water and stirred. In this case, the amount of water is 100 to 1000 parts by mass with respect to 100 parts by mass of the isocyanate group-terminated prepolymer.

[0136] Next, a chain extender is added to the water in which the core material and the isocyanate group-terminated prepolymer are emulsified and dispersed, and the isocyanate group-terminated prepolymer is chain-extended in water.

[0137] The equivalent ratio of the active hydrogen group of the chain extender to the isocyanate group of the isocyanate group-terminated prepolymer (active hydrogen group / isocyanate group) is, for example, 0.8 to 1.2. The chain extension reaction is completed, for example, at room temperature. The time until the completion of the reaction is, for example, 1 minute to 10 hours.

[0138] Then, through the above chain extension reaction, a polyurethane resin is obtained as a reaction product of the polyurethane raw material. Further, the above core material is coated on the polyurethane resin. That is, microcapsules having a core material and a wall material containing the polyurethane resin are obtained.

[0139] Microcapsules are particles having a micro size and are distinguished from particles having a nano size (nanoparticles). The volume average particle diameter of the microcapsules is, for example, 1.0 to 100.0 μm, preferably 1.0 to 50.0 μm, and more preferably 2.0 to 10.0 μm. The method for measuring the volume average particle diameter of the microcapsules conforms to the examples described later.

[0140] The microcapsules are preferably dispersed in water. That is, by the above method, preferably, an aqueous dispersion of the microcapsules is obtained. The solid content concentration of the aqueous dispersion of the microcapsules is, for example, 0.1 to 50% by mass, preferably 1 to 30% by mass.

[0141] (5) Crosslinking agent The prepolymer raw material and / or the polyurethane raw material can contain a crosslinking agent as required. From the viewpoints of the mechanical properties and marine biodegradability of the microcapsules, preferably, the polyurethane raw material contains a crosslinking agent. Also, preferably, the prepolymer raw material does not contain a crosslinking agent.

[0142] Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, carbodiimide-based crosslinking agents, aziridine-based crosslinking agents, and oxazoline-based crosslinking agents. These can be used alone or in combination of two or more. Preferably, an isocyanate crosslinking agent is mentioned as the crosslinking agent. That is, more preferably, the polyurethane raw material contains an isocyanate crosslinking agent.

[0143] Examples of the isocyanate crosslinking agent include aqueous isocyanate crosslinking agents and non-aqueous isocyanate crosslinking agents.

[0144] Examples of the aqueous isocyanate crosslinking agent include polyisocyanate monomers modified with monofunctional polyethylene glycol, polyisocyanate derivatives modified with monofunctional polyethylene glycol, and their blocked isocyanates. These can be used alone or in combination of two or more. As the aqueous isocyanate crosslinking agent, preferably, polyisocyanate monomers modified with monofunctional polyethylene glycol are mentioned, and more preferably, hexamethylene diisocyanate modified with monofunctional polyethylene glycol is mentioned. The polyisocyanate monomer modified with monofunctional polyethylene glycol can be obtained, for example, by the reaction of monofunctional polyethylene glycol (for example, methoxypolyethylene glycol) and the above polyisocyanate monomer.

[0145] Examples of the non-aqueous isocyanate crosslinking agent include the above polyisocyanate monomers not modified with monofunctional polyethylene glycol, the above polyisocyanate derivatives not modified with monofunctional polyethylene glycol, and their blocked isocyanates. These can be used alone or in combination of two or more. As the non-aqueous isocyanate crosslinking agent, preferably, the above polyisocyanate derivatives not modified with monofunctional polyethylene glycol are mentioned, and more preferably, isocyanurate derivatives of pentamethylene diisocyanate are mentioned.

[0146] From the viewpoint of marine biodegradability, preferably, non-aqueous isocyanate crosslinking agents are mentioned as the isocyanate crosslinking agent.

[0147] The timing of adding the crosslinking agent is not particularly limited. For example, when the polyurethane raw material contains a crosslinking agent, after the above neutralization step and before the chain extension reaction, the isocyanate group-terminated prepolymer and the crosslinking agent are mixed. Then, the mixture of the isocyanate group-terminated prepolymer and the crosslinking agent is emulsified and dispersed in water by the above method and subjected to a chain extension reaction.

[0148] The content ratio of the crosslinking agent is appropriately set according to the purpose and application. For example, based on 100 parts by mass of the solid content of the isocyanate group-terminated prepolymer, the content ratio of the crosslinking agent is, for example, 1 to 300 parts by mass, preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, and even more preferably 15 to 50 parts by mass.

[0149] (6) Additives The aqueous dispersion of microcapsules can contain additives (excluding the crosslinking agent). Examples of the additives include heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, surfactants, pH adjusters, defoamers, rust preventives, viscosity adjusters, chelating agents, antistatic agents, binders, fragrances, dyes, and pigments. These can be used alone or in combination of two or more. The addition amount and the timing of adding the additives are appropriately set according to the type of the additives.

[0150] 3. Action and effect In the production of the above microcapsules, the polyol component of the prepolymer raw material contains a vegetable oil polyol and / or a polycaprolactone polyol and a hydrophilic group-containing active hydrogen compound. Therefore, the above microcapsules have excellent marine biodegradability.

[0151] As a result, the above microcapsules are suitably used in various industrial fields where marine biodegradability is required. Examples of the industrial fields where marine biodegradability is required include the fragrance field, the agricultural chemical field, the pharmaceutical field, the paint field, and the adhesive field.

[0152] Note that the usage form of the microcapsules is not particularly limited and is appropriately selected according to the application. For example, depending on the application, the above microcapsules can be used as an aqueous dispersion. Also, the above microcapsules can be used as a dry powder.

Examples

[0153] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. Note that "parts" and "%" are based on mass unless otherwise specified. Also, in the following description, specific numerical values such as blending ratios (content ratios), physical property values, and parameters used can be replaced with the upper limit values (numerical values defined as "hereinafter" and "less than") or lower limit values (numerical values defined as "above" and "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention".

[0154] 1. Production of Microcapsules Example 1 Into a four-necked flask (1 L), 186.6 parts by mass of Econicol EBT-396 (trade name, an ester-modified polyol obtained by the reaction of vegetable oil fatty acid and polyoxypropylene diol (molecular weight 400), average hydroxyl value 56 mgKOH / g, manufactured by Mitsui Chemicals), 191.6 parts by mass of isophorone diisocyanate (IPDI, manufactured by Fujifilm Wako Pure Chemical Industries), 100 parts by mass of ethyl acetate (solvent), and 0.08 parts by mass of stannous octoate (catalyst, trade name Stannocto, manufactured by Mitsubishi Chemical Corporation) were charged. Then, Econicol EBT-396 (vegetable oil polyol) and isophorone diisocyanate (manufactured by Fujifilm Wako Pure Chemical Industries) were reacted at 75°C. Next, 21.8 parts by mass of dimethylolpropionic acid (DMPA, manufactured by Tokyo Chemical Industry Co., Ltd.) was charged into the flask, and subsequently, the contents of the flask were reacted at 75°C. By the above reaction, a reaction product solution containing an isocyanate group-terminated prepolymer (hereinafter, prepolymer solution) was obtained.

[0155] Incidentally, the equivalent ratio of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component (the total amount of the hydroxyl groups in Econicol EBT-396 and the hydroxyl groups in dimethylolpropionic acid) (isocyanate groups / hydroxyl groups) was approximately 3.3.

[0156] The isocyanate group concentration of the prepolymer solution was 10.6% by mass. Also, the solid content concentration of the prepolymer solution was 76.3% by mass.

[0157] Next, 15.7 parts by mass of the prepolymer solution (12.0 parts by mass of the isocyanate group-terminated prepolymer solid content) and 24.3 parts by mass of butyl acetate (core substance) were mixed to obtain a mixture. Next, 0.51 part by mass of triethylamine was added to the mixture to neutralize the prepolymer solution. Next, the entire amount of the neutralized prepolymer solution was added to 360 parts by mass of distilled water, and water and the prepolymer solution were stirred at 12,000 rpm for 2 minutes using a homogenizer. Thus, the isocyanate group-terminated prepolymer was emulsified and dispersed to obtain an emulsion of the isocyanate group-terminated prepolymer (hereinafter, prepolymer emulsion).

[0158] Next, while stirring the prepolymer emulsion at 10°C, 19.8 parts by mass of a 10% aqueous solution of hydrazine monohydrate was added to the prepolymer emulsion and stirred for 2 hours. Thereafter, the temperature was raised to 20°C, and the isocyanate group-terminated prepolymer and hydrazine monohydrate were subjected to a chain extension reaction at 20°C for 2 hours.

[0159] The equivalent ratio of the active hydrogen groups of the chain extender to the isocyanate groups of the isocyanate group-terminated prepolymer (active hydrogen groups / isocyanate groups) was approximately 0.98.

[0160] Thus, a microcapsule aqueous dispersion was obtained. The core substance of the microcapsules contained ethyl acetate, and the wall material contained a polyurethane resin. The solid content concentration of the microcapsule aqueous dispersion was 3.3% by mass.

[0161] 1 g of the microcapsule aqueous dispersion and 10 g of distilled water were mixed, and the volume average particle diameter of the microcapsules was measured using a particle size analyzer Microtrac HRA (manufactured by Nikkiso Co., Ltd.). The volume average particle diameter of the microcapsules was 2.8 μm.

[0162] Examples 2 to 10 and Comparative Example 1 According to the formulation in Table 1, a prepolymer solution and microcapsules were produced in the same manner as in Example 1.

[0163] [Polyisocyanate component] In Examples 2 to 7, pentamethylene diisocyanate (trade name Stabio PDI, manufactured by Mitsui Chemicals, Inc.) was used instead of isophorone diisocyanate (IPDI).

[0164] Also, in Example 8, 1,3-xylylene diisocyanate (trade name Takenate T-500, XDI, manufactured by Mitsui Chemicals, Inc.) was used instead of isophorone diisocyanate (IPDI).

[0165] Also, in Example 9, 1,3-bis(isocyanatomethyl)cyclohexane (trade name Takenate T-600, H 6 XDI, manufactured by Mitsui Chemicals, Inc.) was used instead of isophorone diisocyanate (IPDI).

[0166] [Polyol component] In Example 10, Placcel 210N (trade name, polycaprolactone polyol (CPL2000) with a number average molecular weight of 2000, manufactured by Daicel Corporation) was used instead of Econicol EBT-396 (vegetable oil polyol).

[0167] Also, in Comparative Example 1, PTG-1000 (trade name, polytetramethylene ether glycol with a number average molecular weight of 1000, manufactured by Mitsubishi Chemical Corporation) was used instead of Econicol EBT-396 (vegetable oil polyol).

[0168] [Chain extender] In Examples 4 to 5, hexamethylenediamine was used instead of the 10% hydrazine monohydrate aqueous solution.

[0169] [Crosslinking agent] In Examples 3 and 5, when mixing the prepolymer solution and butyl acetate (core substance), Stabio D-370N (trade name, isocyanate crosslinking agent, isocyanurate derivative of pentamethylene diisocyanate, manufactured by Mitsui Chemicals) was blended. Also, in Example 6, Takenate WD-726 (trade name, isocyanate crosslinking agent, hexamethylene diisocyanate modified with methoxypolyoxyethylene glycol, manufactured by Mitsui Chemicals) was blended into the prepolymer solution. Further, in Example 7, Stabio D-370N (trade name, isocyanate crosslinking agent, isocyanurate derivative of pentamethylene diisocyanate, manufactured by Mitsui Chemicals) and Takenate WD-726 (trade name, isocyanate crosslinking agent, isocyanate compound having a polyoxyethylene chain (methoxy-terminal polyethylene glycol modified hexamethylene diisocyanate), manufactured by Mitsui Chemicals) were blended into the prepolymer solution.

[0170] 2. Evaluation (1) Sample preparation A microcapsule aqueous dispersion was placed in a polypropylene tray so that a film with a thickness of about 100 μm could be obtained. Then, the microcapsule aqueous dispersion was left at room temperature for several days to volatilize water, and then heated at 110 °C for 1 hour to obtain a sample (film).

[0171] (2) Marine biodegradation 600 ml of seawater and 100 g of sea sand were collected on the coast into a 1000 ml flask. Ultrasonic waves were irradiated to the seawater and sea sand for 60 seconds using an ultrasonic irradiation device (manufactured by AS ONE, Vs-F100). Then, the seawater was filtered using a filter bag (manufactured by AS ONE, 420-10). Thus, microorganisms were extracted into the seawater.

[0172] Subsequently, the seawater from which the microorganisms were extracted was placed in a glass bottle. Also, the above sample was cut into a size of 1.5 cm × 3.0 cm, placed in the above glass bottle, and left for 28 days.

[0173] Then, by measuring the Biochemical Oxygen Demand (BOD) in the glass bottle, the amount of carbon dioxide generated by marine biodegradation was calculated to evaluate the marine biodegradability.

[0174] More specifically, first, a pressure sensor type BOD measurement head (manufactured by Zylem) was placed in the head part, and sodium hydroxide pellets for absorbing carbon dioxide were put in.

[0175] Next, the pressure sensor type BOD measurement head (manufactured by Zylem) was attached to the above glass bottle, and the Biochemical Oxygen Demand (BOD) in the glass bottle was measured.

[0176] In the BOD measurement, the capacity of the container (measured value) was 1118 mL. Also, the amount of seawater from which the microorganisms were extracted was 225 mL.

[0177] Then, the oxygen consumption was calculated based on the pressure change of the gas in the container. Also, based on the oxygen consumption, the amount of carbon dioxide generated by marine biodegradation was calculated. Also, the amount of carbon dioxide generated was converted to the amount of carbon dioxide generated per 1.0 × 1.5 cm size (mg). The converted value was used as the measurement value of marine biodegradability.

[0178] For comparison, using cellulose (manufactured by Advantec, filter paper 5C), the amount of carbon dioxide generated by marine biodegradation was calculated in the same manner as above. Also, the amount of carbon dioxide generated was converted to the amount of carbon dioxide generated per 1.0 × 1.5 cm size (mg). The converted value was 6.9 mg.

[0179]

Table 1

[0180] The details of the abbreviations in the table are described below. IPDI: Isophorone diisocyanate, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd. PDI: Pentamethylene diisocyanate, trade name Stabio PDI, manufactured by Mitsui Chemicals, Inc. XDI: 1,3-Xylylene diisocyanate, trade name Takenate T-500, manufactured by Mitsui Chemicals, Inc. H 6 XDI: 1,3-Bis(isocyanatomethyl)cyclohexane, trade name Takenate T-600, manufactured by Mitsui Chemicals, Inc. DMPA: Active hydrogen compound containing hydrophilic group, dimethylolpropionic acid EBT-396: Vegetable oil polyol (ester-modified polyol obtained by reacting castor oil fatty acid with polyoxypropylene diol (molecular weight 400)), average hydroxyl value 56 mgKOH / g, manufactured by Mitsui Chemicals, Inc. CPL2000: Polycaprolactone polyol with a number average molecular weight of 2000, trade name Placcel 210N, manufactured by Daicel Corporation PTG-1000: Polytetramethylene ether glycol with a number average molecular weight of 1000, trade name PTG-1000, manufactured by Mitsubishi Chemical Corporation D-370N: Trade name Stabio D-370N, isocyanate crosslinking agent, isocyanurate derivative of pentamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc. WD-726: Trade name Takenate WD-726, isocyanate crosslinking agent, hexamethylene diisocyanate modified with methoxypolyoxyethylene glycol, manufactured by Mitsui Chemicals, Inc.

Claims

1. A microcapsule containing a core substance and a wall material that coats the core substance, wherein the wall material contains a polyurethane resin, the polyurethane resin contains a reaction product of polyurethane raw materials, the polyurethane raw materials contain an isocyanate group-terminated prepolymer and a chain extender, the isocyanate group-terminated prepolymer contains a reaction product of prepolymer raw materials, the prepolymer raw materials contain a polyisocyanate component and a polyol component, wherein the polyol component contains a vegetable oil polyol and / or a polycaprolactone polyol, and a hydrophilic group-containing active hydrogen compound, is a microcapsule.

2. The microcapsule according to claim 1, wherein the chain extender contains a polymethylene diamine having 2 to 8 carbon atoms.

3. The microcapsule according to claim 1, wherein the polyurethane raw materials further contain an isocyanate crosslinking agent.

4. The microcapsule according to claim 1, wherein the hydrophilic group-containing active hydrogen compound contains an anionic group-containing active hydrogen compound.

5. With respect to the total amount of the vegetable oil polyol and / or the polycaprolactone polyol, the hydrophilic group-containing active hydrogen compound, and the chain extender, the content ratio of the vegetable oil polyol and / or the polycaprolactone polyol is 30 to 95% by mass, and the microcapsule according to claim 1.

6. The microcapsule according to claim 1, wherein the core substance contains a fragrance.

7. The microcapsule according to claim 1, having a volume average particle diameter of 1.0 to 50.0 μm.

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