Polyurethane sealant

Abstract

To provide a polyurethane sealing material that can relatively suppress dripping and yield a cured product with relatively excellent mechanical properties. [Solution] The polyurethane sealing material contains a polyisocyanate component, a polyol component, and a quivimodulator. The polyol component contains a hydrophobic polyol. The quivimodulator contains inorganic fine particles, water, and polyethylene glycol. The content of inorganic fine particles is 30.0 parts by mass or more per 100 parts by mass of hydrophobic polyol. The content of water is 1.0 part by mass or more and 3.0 parts by mass or less per 100 parts by mass of inorganic fine particles. The content of polyethylene glycol is 10.0 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of inorganic fine particles.

Description

Technical Field

[0001] The present invention relates to a polyurethane sealing material.

Background Art

[0002] Conventionally, in various industrial fields, a polyurethane resin has been used as a sealing material (hereinafter referred to as a polyurethane sealing material).

[0003] As the polyurethane sealing material, for example, the following two-component room-temperature curing type urethane coating waterproof material composition has been proposed. The two-component room-temperature curing type urethane coating waterproof material composition includes a main agent and a curing agent. The main agent contains a urethane prepolymer. The curing agent contains a hydrophobic polyol having a number average molecular weight of 1500 to 4000, a polypropylene polyol, and an organic compound having a hydrophilic group and a hydrophobic group (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, for the polyurethane sealing material, suppression of dripping during construction is required. In addition, excellent mechanical properties are required for the cured product of the polyurethane sealing material.

[0006] The present invention is a polyurethane sealing material that can relatively suppress dripping and can obtain a cured product having relatively excellent mechanical properties.

Means for Solving the Problems

[0007] The present invention [1] includes a polyurethane sealing material comprising a polyisocyanate component, a polyol component, and a quinostat, wherein the polyol component contains a hydrophobic polyol, the quinostat contains inorganic fine particles, water, and polyethylene glycol, the content of the inorganic fine particles is 30.0 parts by mass or more per 100 parts by mass of the hydrophobic polyol, the content of the water is 1.0 part by mass or more and 3.0 parts by mass or less per 100 parts by mass of the inorganic fine particles, and the content of the polyethylene glycol is 10.0 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of the inorganic fine particles.

[0008] The present invention [2] includes the polyurethane sealing material described in [1] above, wherein the hydrophobic polyol contains a polybutadiene polyol.

[0009] The present invention [3] includes a polyurethane sealing material according to [1] or [2] above, wherein the polyisocyanate component contains an isocyanate-terminated prepolymer, the isocyanate-terminated prepolymer contains a reaction product of a raw material polyisocyanate and a raw material polyol, and the raw material polyisocyanate contains diphenylmethane diisocyanate.

[0010] The present invention [4] further comprises a polyurethane sealing material according to any one of the above [1] to [3], which contains an organic solvent.

[0011] The present invention [5] comprises the polyurethane sealing material described in [4] above, wherein the organic solvent contains mineral oil. [Effects of the Invention]

[0012] The polyurethane sealing material of the present invention contains a polyisocyanate component, a polyol component, and a quiviander. The polyol component contains a hydrophobic polyol. The quiviander contains inorganic fine particles, water, and polyethylene glycol in predetermined proportions. Therefore, the above polyurethane sealing material can relatively suppress dripping and produce a cured product with relatively excellent mechanical properties (particularly hardness and tensile properties). [Modes for carrying out the invention]

[0013] 1. Polyurethane sealant (1) Overall structure The polyurethane sealant contains a polyisocyanate component, a polyol component, and a quiviander. In other words, the polyurethane sealant is a polyurethane composition containing a polyisocyanate component, a polyol component, and a quiviander. The polyurethane sealant produces a cured product (described later) through a reaction between the polyisocyanate component and the polyol component.

[0014] The polyurethane sealing material may be, for example, a one-component polyurethane sealing material containing a polyisocyanate component, a polyol component, and a thixotroper.

[0015] Furthermore, the polyurethane sealant may be a two-component polyurethane sealant comprising, for example, a first liquid containing a polyisocyanate component and a second liquid containing a polyol component separately. In other words, the polyurethane sealant may be a two-component curing resin kit. In a two-component polyurethane sealant, the quivimodifier may be contained in the first liquid and / or the second liquid. Alternatively, the quivimodifier may be prepared separately from the first and second liquids and added when the first and second liquids are combined.

[0016] Alternatively, the polyurethane sealing material may be a three-component polyurethane sealing material that separately contains, for example, a first liquid containing a polyisocyanate component, a second liquid containing a polyol component, and a third liquid containing a thixotropic agent. That is, the polyurethane sealing material may be a three-component curable resin kit.

[0017] Preferably, the polyurethane sealing material is a two-component polyurethane sealing material. That is, the polyurethane sealing material separately contains a first liquid containing a polyisocyanate component and a second liquid containing a polyol component. In the two-component polyurethane sealing material, the thixotropic agent is preferably contained in the second liquid. Hereinafter, the first liquid and the second liquid will be described in detail.

[0018] (2) First Liquid The first liquid is a curing agent in the two-component polyurethane sealing material. The first liquid contains a polyisocyanate component.

[0019] [Polyisocyanate Component] Examples of the polyisocyanate component include isocyanate group-terminated prepolymers. That is, the polyisocyanate component contains, for example, an isocyanate group-terminated prepolymer and preferably consists of an isocyanate group-terminated prepolymer.

[0020] The isocyanate group-terminated prepolymer contains a reaction product of a raw material polyisocyanate and a raw material polyol.

[0021] Examples of raw material polyisocyanates include polyisocyanate monomers and polyisocyanate derivatives. Examples of polyisocyanate monomers include aromatic polyisocyanates, aliphatic polyisocyanates, and aromatic aliphatic polyisocyanates. Examples of aromatic polyisocyanates include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), toluidine diisocyanate (TODI), paraphenylenedi diisocyanate, and naphthalene diisocyanate (NDI). Examples of aliphatic polyisocyanates include linear aliphatic polyisocyanates and alicyclic polyisocyanates. Examples of linear aliphatic polyisocyanates include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and methylenebis(cyclohexyl isocyanate) (H 12 Examples include MDI and bis(isocyanatomethyl)cyclohexane (H6XDI). Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). Polyisocyanate monomers can be used alone or in combination of two or more. Examples of polyisocyanate derivatives include modified polyisocyanate monomers obtained by known methods. Examples of modified polyisocyanates include uretdione modified polyisocyanates, isocyanurate modified polyisocyanates, allophanate modified polyisocyanates, polyol modified polyisocyanates, biuret modified polyisocyanates, urea modified polyisocyanates, oxadiazinetrione modified polyisocyanates, and carbodiimide modified polyisocyanates. These can be used alone or in combination of two or more.

[0022] The raw material polyisocyanate can be used alone or in combination of two or more kinds. From the viewpoint of mechanical properties (especially hardness and tensile properties), as the raw material polyisocyanate, preferably, polyisocyanate monomers are mentioned, more preferably, aromatic polyisocyanates are mentioned, and still more preferably, diphenylmethane diisocyanate is mentioned. That is, the raw material polyisocyanate preferably contains polyisocyanate monomers, more preferably contains aromatic polyisocyanates, still more preferably contains diphenylmethane diisocyanate, and particularly preferably consists of diphenylmethane diisocyanate.

[0023] Examples of diphenylmethane diisocyanate include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate. These can be used alone or in combination of two or more kinds. As diphenylmethane diisocyanate, preferably, 4,4'-diphenylmethane diisocyanate is mentioned.

[0024] [Raw material polyol] Examples of the raw material polyol include low molecular weight polyols and high molecular weight polyols.

[0025] The low molecular weight polyol has two or more hydroxyl groups in the molecule and is a relatively low molecular weight organic compound. The molecular weight of the low molecular weight polyol is, for example, 40 or more and less than 400, preferably 300 or less.

[0026] Examples of low molecular weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols 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, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. In addition, polymers obtained by addition polymerization of alkylene (C2-3) oxide to dihydric to tetrahydric alcohols so that the number average molecular weight is less than 400 can also be used as low molecular weight polyols. These can be used individually or in combination of two or more types.

[0027] High molecular weight polyols are relatively high molecular weight organic compounds that have two or more hydroxyl groups in their molecule. The number-average molecular weight of high molecular weight polyols is, for example, 400 or more, preferably 500 or more, and for example, 20,000 or less. The number-average molecular weight can be calculated from the hydroxyl group equivalent and the average number of hydroxyl groups using known methods. The number-average molecular weight can also be measured as polystyrene-equivalent molecular weight by gel permeation chromatography (GPC) (the same applies hereinafter).

[0028] Examples of high molecular weight polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used individually or in combination of two or more types.

[0029] The number-average molecular weight of the high molecular weight polyol is, for example, 400 to 20,000, preferably 500 to 15,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 5,000. The average number of hydroxyl groups of the high molecular weight polyol is, for example, 2.0 to 6.0, preferably 2.0 to 4.0, and more preferably 2.0 to 3.0.

[0030] The raw material polyol can be used alone or in combination of two or more types. Preferably, the raw material polyol is a high molecular weight polyol, and more preferably, a polyether polyol. That is, the raw material polyol preferably contains a high molecular weight polyol, more preferably contains a polyether polyol, and even more preferably consists of a polyether polyol.

[0031] Examples of polyether polyols include polyoxyalkylene polyols. Examples of polyoxyalkylene polyols include polyoxyalkylene (carbon number (C) 2-3) polyols and polytetramethylene ether polyols.

[0032] Examples of polyoxyalkylene (C2-3) polyols include polyethylene polyols, polypropylene polyols, polyoxytriethylene polyols, and polyethylene-polypropylene polyols (random or block copolymers).

[0033] Examples of polytetramethylene ether polyols include ring-opening polymers (crystalline polytetramethylene ether glycols) obtained by cationic polymerization of tetrahydrofuran. Examples of polytetramethylene ether polyols include amorphous polytetramethylene ether glycols. In amorphous polytetramethylene ether glycols, tetrahydrofuran is copolymerized with alkyl-substituted tetrahydrofuran and / or dihydric alcohols. Crystalline refers to a solid at 25°C, while amorphous refers to a liquid at 25°C.

[0034] Polyether polyols can be used alone or in combination of two or more types. Preferably, polyoxyalkylene (C2-3) polyols are used as polyether polyols, and more preferably, polypropylene polyols are used.

[0035] The number-average molecular weight of the polyether polyol is, for example, 400 to 20,000, preferably 500 to 15,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 5,000. The average number of hydroxyl groups of the polyether polyol is, for example, 2.0 to 6.0, preferably 2.0 to 4.0, and more preferably 2.0 to 3.0.

[0036] The polyether polyol preferably contains two or more types of polyether polyols, and more preferably contains a polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 2.0 and a polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 3.0. The ratio of the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 2.0 to the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 3.0 is appropriately set according to the purpose and application. For example, the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 2.0 is present in an amount of 50 to 99% by mass, preferably 60 to 95% by mass, and more preferably 70 to 90% by mass, relative to the total amount of the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 2.0 and the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 3.0. Furthermore, the polyoxyalkylene (C2-3) polyol with an average hydroxyl group count of 3.0 is present in an amount of, for example, 1 to 50% by mass, preferably 5 to 40% by mass, and more preferably 10 to 30% by mass.

[0037] Preferably, the product contains a polyoxyalkylene (C2-3) polyol with a number average molecular weight of less than 3000 and a polyoxyalkylene (C2-3) polyol with a number average molecular weight of 3000 or more. The ratio of polyoxyalkylene (C2-3) polyol with a number average molecular weight of less than 3000 to polyoxyalkylene (C2-3) polyol with a number average molecular weight of 3000 or more is appropriately set according to the purpose and application. For example, the amount of polyoxyalkylene (C2-3) polyol with a number average molecular weight of less than 3000 is, for example, 50 to 99% by mass, preferably 60 to 95% by mass, and more preferably 70 to 90% by mass, relative to the total amount of polyoxyalkylene (C2-3) polyol with a number average molecular weight of less than 3000 and polyoxyalkylene (C2-3) polyol with a number average molecular weight of 3000 or more. Furthermore, the polyoxyalkylene (C2-3) polyol with a number average molecular weight of 3000 or more is present in an amount of, for example, 1 to 30% by mass, preferably 3 to 20% by mass, and more preferably 5 to 10% by mass.

[0038] Isocyanate-terminated prepolymers can be obtained, for example, by reacting a raw material polyisocyanate with a raw material polyol in a predetermined ratio.

[0039] The mixing ratio of the raw material polyisocyanate to the raw material polyol is adjusted so that there is an excess of isocyanate groups relative to hydroxyl groups. More specifically, the equivalent ratio of isocyanate groups in the raw material polyisocyanate to hydroxyl groups in the raw material polyol (isocyanate groups / hydroxyl groups) is, for example, 1.2 to 10, preferably 1.5 to 5, and more preferably 1.8 to 3.0.

[0040] The reaction method between the raw material polyisocyanate and the raw material polyol is not particularly limited. Specifically, the reaction methods include bulk polymerization and solution polymerization. In bulk polymerization, for example, the raw material polyisocyanate and the raw material polyol are reacted under a nitrogen atmosphere. The reaction temperature is, for example, 50 to 250°C, preferably 70 to 200°C. The reaction time is, for example, 0.5 to 24 hours, preferably 1 to 15 hours. In solution polymerization, the raw material polyisocyanate and the raw material polyol are reacted in the presence of a known organic solvent. The reaction temperature is, for example, 50 to 120°C, preferably 70 to 100°C. The reaction time is, for example, 0.5 to 24 hours, preferably 1 to 15 hours.

[0041] Furthermore, in the above reaction, known urethane catalysts may be added as needed. Examples of urethane catalysts include amine catalysts and organometallic catalysts. The addition ratio of the urethane catalyst is set appropriately according to the purpose and application.

[0042] Then, the reaction of the raw material polyisocyanate and raw material polyol yields a reaction product containing an isocyanate-terminated prepolymer. This reaction product can be used as a polyisocyanate component.

[0043] Furthermore, the reaction product obtained from the above reaction may contain unreacted raw material polyisocyanate in addition to the isocyanate-terminated prepolymer. In other words, the polyisocyanate component may contain unreacted raw material polyisocyanate in addition to the isocyanate-terminated prepolymer. The proportion of unreacted raw material polyisocyanate is set appropriately according to the purpose and application.

[0044] Furthermore, the polyisocyanate component does not necessarily have to contain unreacted raw material polyisocyanate. In such cases, the unreacted raw material polyisocyanate is removed from the reaction product. Examples of removal methods include distillation and extraction.

[0045] The isocyanate group concentration (isocyanate group content, NCO%) of the polyisocyanate component is, for example, 1.0 to 15.0% by mass, preferably 5.0 to 10.0% by mass. The isocyanate group concentration is measured in accordance with the isocyanate group content test described in JIS K 7301 (1995).

[0046] [Organic solvents] The first liquid may contain an organic solvent as needed. Examples of organic solvents include ketones, nitriles, alkyl esters, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ethers, glycol ether esters, halogenated aliphatic hydrocarbons, and polar aprotons. These can be used individually or in combination of two or more. The content ratio of the organic solvent is set appropriately according to the purpose and application. Preferably, the first liquid does not contain an organic solvent.

[0047] [Additives] The first liquid may contain additives as needed. Examples of additives include fillers, plasticizers, urethane catalysts (e.g., organotin compounds), antioxidants (e.g., bisphenol-based antioxidants and dithiocarbamate-based antioxidants), antioxidants, UV absorbers, heat stabilizers, light stabilizers, organic solvents, pigments (e.g., black toner), dyes, defoamers, toners, dispersants, anti-blocking agents, mold release agents, lubricants, hydrolysis inhibitors, rust inhibitors, and bluing agents. These may be used individually or in combination of two or more. The amount and timing of addition of the above additives should be appropriately determined according to the purpose and application.

[0048] (2)Second liquid The second liquid is the main component in the two-component polyurethane sealant. The second liquid contains a polyol component and a thixotroper. In other words, the second liquid is a polyol composition.

[0049] [Polyol components] The polyol component contains a hydrophobic polyol. A hydrophobic polyol is a polyol with a relatively high proportion of hydrocarbon moieties in its molecule. The hydrocarbon moieties are groups consisting of carbon atoms and hydrogen atoms. The content of the hydrocarbon moieties is, for example, 30% by mass or more, preferably 50% by mass or more, relative to the total amount of hydrophobic polyol. Furthermore, the content of the hydrocarbon moieties is, for example, 99% by mass or less, relative to the total amount of hydrophobic polyol. The content of the hydrocarbon moieties is calculated based on the molecular structure and molecular weight of the hydrophobic polyol.

[0050] More specifically, hydrophobic polyols include, for example, castor oils, dimer acid polyols, and polyolefin polyols. These can be used individually or in combination of two or more. From the viewpoint of mechanical properties (particularly hardness and tensile properties), polyolefin polyols are preferred. That is, hydrophobic polyols preferably contain polyolefin polyols, and more preferably consist of polyolefin polyols.

[0051] Examples of polyolefin polyols include polybutadiene polyols and partially saponified ethylene-vinyl acetate copolymers. These can be used individually or in combination of two or more. From the viewpoint of mechanical properties (particularly hardness and tensile properties), polybutadiene polyols are preferred. That is, polyolefin polyols preferably contain polybutadiene polyols, and more preferably consist of polybutadiene polyols. In other words, hydrophobic polyols, from the viewpoint of mechanical properties (particularly hardness and tensile properties), preferably contain polybutadiene polyols, and even more preferably consist of polybutadiene polyols.

[0052] The number-average molecular weight (standard polystyrene equivalent molecular weight by gel permeation chromatography (GPC)) of the hydrophobic polyol is not particularly limited, but for example, it is 400 to 20,000, preferably 500 to 15,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 5,000. The average number of hydroxyl groups of the hydrophobic polyol is not particularly limited, but for example, it is 2.0 to 6.0, preferably 2.0 to 4.0, more preferably 2.0 to 3.0, and particularly preferably 2.0.

[0053] The polyol component may contain other polyols (i.e., polyols other than hydrophobic polyols) as needed. That is, the polyol component may be a hydrophobic polyol alone, or it may be used in combination with other polyols. Examples of other polyols include non-hydrophobic polyols, and more specifically, the low molecular weight polyols and high molecular weight polyols (excluding hydrophobic polyols) mentioned above. Other polyols may be used alone or in combination of two or more types. The content ratio of other polyols is set appropriately according to the purpose and application. Preferably, the polyol component does not contain other polyols (polyols other than hydrophobic polyols). That is, the polyol component preferably consists of a hydrophobic polyol.

[0054] [Phenoxin] The quiviate contains inorganic fine particles, water, and polyethylene glycol. Preferably, the quiviate consists of inorganic fine particles, water, and polyethylene glycol.

[0055] Inorganic microparticles form a cross-linked structure through interactions at their particle surfaces. Therefore, inorganic microparticles regulate the thixotropy of polyurethane sealing materials, suppress dripping, and further improve the mechanical properties (particularly hardness and tensile properties) of the cured product (described later).

[0056] Inorganic nanoparticles are fine particles of inorganic compounds. Examples of inorganic compounds include silica, alumina, tin, and titanium. That is, examples of inorganic nanoparticles include silica nanoparticles, alumina nanoparticles, tin nanoparticles, and titanium nanoparticles. More specifically, inorganic nanoparticles include colloidal inorganic particles.

[0057] Examples of colloidal inorganic particles include slurries of inorganic fine particles and powders of inorganic fine particles. More specifically, examples of colloidal inorganic particles include colloidal silica, colloidal alumina (alumina sol), colloidal tin oxide (aqueous dispersion of tin oxide), and colloidal titanium oxide (titania sol). These can be used individually or in combination of two or more types.

[0058] Preferably, the inorganic fine particles are silica fine particles. The silica fine particles may be wet silica or dry silica. Preferably, the silica fine particles are dry silica. The shape of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose and application.

[0059] The average particle diameter of the primary particles of inorganic fine particles is, for example, 1 nm or more, preferably 5 nm or more, and more preferably 7 nm or more. Alternatively, the average particle diameter of the primary particles of inorganic fine particles is, for example, 1000 nm or less, preferably 100 nm or less, and even more preferably 40 nm or less. In other words, the average particle diameter of the primary particles of inorganic fine particles is, for example, 1 nm or more and 1000 nm or less, preferably 5 nm or more and 100 nm or less, and more preferably 7 nm or more and 40 nm or less. The average particle diameter of the primary particles of inorganic fine particles can be measured by known methods as the number-average particle diameter using dynamic light scattering.

[0060] Inorganic microparticles are manufactured by known methods. Examples of methods for manufacturing inorganic microparticles include known thermal decomposition methods, high-temperature hydrolysis methods, and sol-gel methods. Inorganic microparticles are also available commercially, for example. Examples of commercially available inorganic microparticles include the Aerosil series (colloidal silica, manufactured by Nippon Aerosil Co., Ltd.), Rheoroseal (colloidal silica, manufactured by Tokuyama Corporation), the HDK series (colloidal silica, manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), and the CAB-O-SIL series (colloidal silica, manufactured by CABOT Corporation). These can be used individually or in combination of two or more types.

[0061] The proportion of inorganic fine particles is adjusted according to the amount of hydrophobic polyol.

[0062] More specifically, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the content of inorganic fine particles (solids) is 30.0 parts by mass or more, preferably 30.2 parts by mass or more, more preferably 30.5 parts by mass or more, and even more preferably 30.7 parts by mass or more, per 100 parts by mass of hydrophobic polyol. Alternatively, the content of inorganic fine particles (solids) is, for example, 300 parts by mass or less, preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of hydrophobic polyol. In other words, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the content ratio of inorganic fine particles (solids) is, for example, 30.0 parts by mass or more and 300 parts by mass or less, preferably 30.2 parts by mass or more and 200 parts by mass or less, more preferably 30.5 parts by mass or more and 100 parts by mass or less, and even more preferably 30.7 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of hydrophobic polyol.

[0063] Furthermore, the proportion of inorganic fine particles can be adjusted, for example, as a mass ratio to the total volume of the second liquid.

[0064] More specifically, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the content of inorganic fine particles (solids) is, for example, more than 6.0% by mass, preferably 6.5% by mass or more, and more preferably 7.0% by mass or more, relative to the total amount of the second liquid. Also, the content of inorganic fine particles (solids) is, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less, relative to the total amount of the second liquid. That is, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the content of inorganic fine particles (solids) is, for example, more than 6.0% by mass and 30% by mass or less, preferably 6.5% by mass or more and 20% by mass or less, and more preferably 7.0% by mass or more and 10% by mass or less, relative to the total amount of the second liquid.

[0065] Water forms hydrogen bonds with the surface of inorganic microparticles, creating a pseudo-crosslinked structure. As a result, water regulates the thixotropy of the polyurethane sealant, suppresses dripping, and further improves the mechanical properties of the cured product (described later).

[0066] The water content is adjusted according to the amount of inorganic particles.

[0067] More specifically, from the viewpoint of suppressing dripping and the mechanical properties (particularly hardness) of the cured product (described later), the water content is 1.0 part by mass or more, preferably 1.05 parts by mass or more, and more preferably 1.1 parts by mass or more, per 100 parts by mass of inorganic fine particles (solids). Furthermore, from the viewpoint of suppressing foaming of the polyurethane sealant and obtaining a cured product (described later) with excellent mechanical properties (particularly tensile properties), the water content is 3.0 parts by mass or less, preferably 2.9 parts by mass or less, and more preferably 2.5 parts by mass or less, per 100 parts by mass of inorganic fine particles (solids). In other words, from the viewpoint of suppressing dripping and the mechanical properties (particularly hardness and tensile properties) of the cured product (described later), the water content is 1.0 part by mass or more and 3.0 parts by mass or less, preferably 1.05 parts by mass or more and 2.9 parts by mass or less, and more preferably 1.1 parts by mass or more and 2.5 parts by mass or less, per 100 parts by mass of inorganic fine particles (solids).

[0068] Furthermore, the water content can be adjusted, for example, as a mass ratio to the total volume of the second liquid.

[0069] More specifically, from the viewpoint of suppressing dripping and the mechanical properties (particularly hardness) of the cured product (described later), the water (solids) content is, for example, 0.08% by mass or more, preferably 0.09% by mass or more, and more preferably 0.10% by mass or more, relative to the total amount of the second liquid. Furthermore, from the viewpoint of suppressing foaming of the polyurethane sealing material and obtaining a cured product (described later) with excellent mechanical properties (particularly tensile properties), the water (solids) content is, for example, 0.20% by mass or less, preferably 0.18% by mass or less, and more preferably 0.15% by mass or less, relative to the total amount of the second liquid. In other words, from the viewpoint of suppressing dripping, suppressing foaming, and the mechanical properties of the cured product (described later) (especially hardness and tensile properties), the water (solid content) content is, for example, 0.08% by mass or more and 0.20% by mass or less, preferably 0.09% by mass or more and 0.18% by mass or less, and more preferably 0.10% by mass or more and 0.15% by mass or less, relative to the total amount of the second liquid.

[0070] Polyethylene glycol forms hydrogen bonds with the surface of inorganic fine particles, creating a pseudo-crosslinked structure and adjusting the crosslinking density through hydrogen bonding. As a result, polyethylene glycol regulates the thixotropy of polyurethane sealants, suppresses dripping, and further improves the mechanical properties of the cured product (described later).

[0071] Examples of polyethylene glycol include well-known polyethylene glycols. The number-average molecular weight (standard polystyrene equivalent molecular weight measured by GPC) of polyethylene glycol is, for example, 400 to 20,000, preferably 500 to 15,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 5,000. The average number of hydroxyl groups of polyethylene glycol is 2.0.

[0072] The polyethylene glycol content is adjusted according to the amount of inorganic fine particles.

[0073] More specifically, from the viewpoint of suppressing dripping and the mechanical properties (particularly hardness) of the cured product (described later), the polyethylene glycol content is 10.0 parts by mass or more, preferably 12.0 parts by mass or more, more preferably 13.0 parts by mass or more, and even more preferably 14.0 parts by mass or more, per 100 parts by mass of inorganic fine particles (solids). Furthermore, from the viewpoint of the mechanical properties (particularly tensile properties) of the cured product (described later), the polyethylene glycol content is 20.0 parts by mass or less, preferably 18.0 parts by mass or less, more preferably 16.0 parts by mass or less, and even more preferably 15.0 parts by mass or less, per 100 parts by mass of inorganic fine particles (solids). In other words, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the polyethylene glycol content is 10.0 parts by mass or more and 20.0 parts by mass or less, preferably 12.0 parts by mass or more and 18.0 parts by mass or less, more preferably 13.0 parts by mass or more and 16.0 parts by mass or less, and even more preferably 14.0 parts by mass or more and 15.0 parts by mass or less, per 100 parts by mass of inorganic fine particles (solids).

[0074] Furthermore, the polyethylene glycol content can be adjusted, for example, as a mass ratio relative to the total amount of the second liquid.

[0075] More specifically, from the viewpoint of suppressing dripping and the mechanical properties (particularly hardness) of the cured product (described later), the content of polyethylene glycol (solids) is, for example, 0.80% by mass or more, preferably 0.90% by mass or more, and more preferably 0.95% by mass or more, relative to the total amount of the second liquid. Furthermore, from the viewpoint of the mechanical properties (particularly tensile properties) of the cured product (described later), the content of polyethylene glycol (solids) is, for example, 1.20% by mass or less, preferably 1.15% by mass or less, and more preferably 1.10% by mass or less, relative to the total amount of the second liquid. In other words, from the viewpoint of suppressing dripping and the mechanical properties of the cured product (described later) (particularly hardness and tensile properties), the content of polyethylene glycol (solids) is, for example, 0.80% by mass or more and 1.20% by mass or less, preferably 0.90% by mass or more and 1.15% by mass or less, and more preferably 0.95% by mass or more and 1.10% by mass or less, relative to the total amount of the second liquid.

[0076] The thixotrope is prepared by known methods and mixed with the polyol component by known methods. For example, inorganic fine particles, water, and polyethylene glycol may be prepared individually without being mixed. In such cases, the inorganic fine particles, water, and polyethylene glycol are added to and mixed with the polyol component simultaneously or in any order in the above proportions. Alternatively, for example, at least one of the inorganic fine particles, water, and polyethylene glycol may be pre-mixed. For example, all of the inorganic fine particles, water, and polyethylene glycol may be pre-mixed in the above proportions. In such cases, the mixed composition of inorganic fine particles, water, and polyethylene glycol is added to and mixed with the polyol component.

[0077] [Organic solvents] The second liquid may contain an organic solvent as needed. Preferably, the second liquid contains an organic solvent. In other words, the polyurethane sealing material preferably contains an organic solvent.

[0078] Examples of organic solvents include hydrophilic solvents and hydrophobic solvents. From the viewpoint of compatibility, hydrophobic solvents are preferred. That is, the organic solvent preferably contains a hydrophobic solvent.

[0079] Examples of hydrophobic solvents include esters, ether esters, and hydrocarbons. Examples of esters include ethyl acetate and butyl acetate. Examples of ether esters include propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate. Examples of hydrocarbons include aromatic hydrocarbons and aliphatic hydrocarbons. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of aliphatic hydrocarbons include hexane, 2-ethylhexyl, cyclohexane, and methylcyclohexane. Examples of hydrocarbons include mineral oil. More specifically, examples of mineral oil include aliphatic hydrocarbons having 10 or more carbon atoms. Examples of aliphatic hydrocarbons having 10 or more carbon atoms include paraffinic aliphatic hydrocarbons and naphthenic aliphatic hydrocarbons. These can be used alone or in combination of two or more. Hydrophobic solvents are preferably hydrocarbons, and more preferably mineral oil. In other words, the organic solvent preferably contains a hydrophobic solvent, more preferably contains hydrocarbons, and even more preferably contains mineral oil.

[0080] Furthermore, from the viewpoint of improving the plasticity of the polyurethane sealing material, a high-boiling-point solvent is preferably used as the organic solvent in the second liquid. A high-boiling-point solvent is an organic solvent having a relatively high boiling point (for example, 300°C or higher). More specifically, the boiling point of the high-boiling-point solvent is, for example, 300°C or higher, preferably 350°C or higher. The boiling point of the high-boiling-point solvent is, for example, 500°C or lower. More specifically, mineral oil can be used as an example of a high-boiling-point solvent.

[0081] In the second liquid, the content ratio of the organic solvent is set appropriately according to the purpose and application. For example, from the viewpoint of the plasticity of the polyurethane sealing material, the content ratio of the organic solvent is, for example, 100 parts by mass or more, preferably 200 parts by mass or more, and more preferably 250 parts by mass or more, per 100 parts by mass of hydrophobic polyol. Alternatively, the content ratio of the organic solvent is, for example, 800 parts by mass or less, preferably 600 parts by mass or less, and more preferably 500 parts by mass or less, per 100 parts by mass of hydrophobic polyol. In other words, the content ratio of the organic solvent is, for example, 100 parts by mass or more and 800 parts by mass or less, preferably 200 parts by mass or more and 600 parts by mass or less, and more preferably 250 parts by mass or more and 500 parts by mass or less, per 100 parts by mass of hydrophobic polyol.

[0082] Furthermore, from the viewpoint of plasticity, the content of the organic solvent is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, relative to the total amount of the second liquid. Alternatively, the content of the organic solvent is, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, relative to the total amount of the second liquid. In other words, the content of the organic solvent is, for example, 30% by mass or more and 90% by mass or less, preferably 40% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 75% by mass or less, and even more preferably 60% by mass or more and 70% by mass or less, relative to the total amount of the second liquid.

[0083] [Additives] The second liquid may contain the above-mentioned additives as needed. The additives can be used alone or in combination of two or more types. Preferred additives include urethane catalysts (e.g., organotin compounds), antioxidants (e.g., bisphenol-based antioxidants and dithiocarbamate-based antioxidants), and pigments (e.g., black toner). The amount and timing of the addition of the above-mentioned additives should be appropriately set according to the purpose and application.

[0084] [2] How to use polyurethane sealant The method of using the polyurethane sealant is not particularly limited, and known methods can be employed. For example, when using a two-component polyurethane sealant, the first liquid and the second liquid are first mixed to prepare a mixed composition. The mixing ratio of the first liquid and the second liquid is adjusted, for example, based on the equivalent ratio of the isocyanate groups of the polyisocyanate component in the first liquid to the hydroxyl groups of the polyol component in the second liquid.

[0085] More specifically, from the viewpoint of pot life and mechanical properties, the equivalent ratio (isocyanate groups / hydroxyl groups) of the polyisocyanate component in the first solution to the hydroxyl groups of the polyol component in the second solution is, for example, 0.8 to 1.5, preferably 0.9 to 1.2, and more preferably 0.95 to 1.2.

[0086] Furthermore, in this method, the above-mentioned additive and / or the above-mentioned organic solvent can be added to the mixed composition of the first and second liquids as needed. The amount and timing of the addition of the above-mentioned additive and / or the above-mentioned organic solvent will be appropriately set according to the purpose and application.

[0087] Next, in this method, the mixed composition is applied to any location and cured under appropriate conditions. The curing conditions are not particularly limited. For example, the curing temperature is, for example, 0 to 60°C, preferably 5 to 50°C, and more preferably 10 to 40°C. The curing time is, for example, 1 to 240 hours, preferably 5 to 200 hours.

[0088] Then, by curing the above mixed composition, a polyurethane resin is obtained as a cured product of the polyurethane sealing material.

[0089] [3] Effects The polyurethane sealing material described above contains a polyisocyanate component, a polyol component, and a quiviander. The polyol component contains a hydrophobic polyol. The quiviander contains inorganic fine particles, water, and polyethylene glycol in predetermined proportions. Therefore, the polyurethane sealing material described above can relatively suppress dripping and produce a cured product with relatively excellent mechanical properties.

[0090] More specifically, in the polyurethane sealant described above, the thixotroper contains inorganic fine particles, water, and polyethylene glycol. The inorganic fine particles form a crosslinked structure through interactions on their particle surfaces, thereby adjusting the thixotropy of the polyurethane sealant. The water also forms a pseudo-crosslinked structure by hydrogen bonding with the surface of the inorganic fine particles. The polyethylene glycol also forms a pseudo-crosslinked structure by hydrogen bonding with the surface of the inorganic fine particles and adjusts the crosslinking density through hydrogen bonding. In the polyurethane sealant described above, the content ratio of inorganic fine particles, the content ratio of water, and the content ratio of polyethylene glycol are each adjusted to the above ranges. As a result, the crosslinking density can be appropriately adjusted with the polyurethane sealant described above, making it possible to suppress liquid dripping and achieve both excellent mechanical properties (particularly hardness and tensile properties).

[0091] Therefore, the polyurethane sealing material and its cured product are widely used in various industrial fields. For example, the polyurethane sealing material and its cured product are used to seal gaps in three-dimensional structures in various industrial fields.

[0092] More specifically, for example, the first liquid and the second liquid are mixed, and this mixed composition is applied to the gaps in the three-dimensional structures of various facilities using a known method and allowed to harden. As a result, a hardened polyurethane sealant is formed in the gaps of the three-dimensional structures. In other words, the gaps in the three-dimensional structures are sealed by the hardened polyurethane sealant.

[0093] Furthermore, because the polyurethane sealant described above is used in the method described above, dripping is relatively suppressed. Therefore, regardless of the position and angle of the gaps in the three-dimensional structure, the polyurethane sealant can be efficiently filled into the gaps and cured. Moreover, the gaps in the three-dimensional structure can be filled with a cured product that has relatively excellent mechanical properties. [Examples]

[0094] Next, the present invention will be described based on synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" and "%" are based on mass. Furthermore, specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0095] [1] First liquid (hardener) Manufacturing Example 1 Isocyanate-terminated prepolymers were prepared by the following method.

[0096] Specifically, 578 parts by mass of polyoxypropylene glycol (raw material polyol, average number of hydroxyl groups 2, number average molecular weight 2000), 101 parts by mass of polyoxypropylene triol (raw material polyol, average number of hydroxyl groups 3, number average molecular weight 5000), and 321 parts by mass of 4,4'-diphenylmethane diisocyanate (raw material polyisocyanate, 4,4'-MDI) were reacted under a nitrogen stream at 80°C for 2 hours to obtain an isocyanate-terminated prepolymer.

[0097] Furthermore, the equivalent ratio of isocyanate groups in the raw material polyisocyanate to hydroxyl groups in the raw material polyol (isocyanate groups / hydroxyl groups) was 4.02.

[0098] The isocyanate group content (NCO concentration) of the isocyanate-terminated prepolymer was 8.08% by mass. The viscosity of the isocyanate-terminated prepolymer at 25°C was 4,300 mPa·s. The obtained isocyanate-terminated prepolymer was used as the first liquid (curing agent). [2] Second solution (main component) Preparation Examples 1-4 and Comparative Preparation Examples 1-6 The polyol composition was prepared by the following method.

[0099] Specifically, according to the formulation shown in Table 1, the following are used: polybutadiene polyol (hydrophobic polyol, trade name Poly bd R-45 HT, number average molecular weight 2800, hydroxyl value 46.6 mgKOH / g, manufactured by Idemitsu Petrochemical Co., Ltd.), mineral oil (organic solvent, trade name Fucol FR-LA, manufactured by Air Water Inc.), bisphenol-based antioxidant (trade name Nocrack NS-30, manufactured by Ouchi Shinko Chemical Industry Co., Ltd., 2,2'-methylenebis(4-methyl-6-tert-butylphenol)), dithiocarbamate-based antioxidant (trade name Noxellar PZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd., zinc dimethyldithiocarbamate), black toner (pigment, trade name SKT 6-0613 Black, manufactured by Saika Chemical Industry Co., Ltd.), and organotin compound (urethane catalyst, trade name Neostan). U-100 (manufactured by Nitto Kasei Co., Ltd.) was placed in a 1-liter container, and the contents of the container were mixed for 10 minutes using a chemical stirrer.

[0100] Furthermore, according to the formulation shown in Table 1, colloidal silica (inorganic microparticle powder, thixotrope, trade name Aerosil #200, manufactured by Nippon Aerosil Co., Ltd.), water (thixotrope), and polyethylene glycol (thixotrope, trade name PEG-1000, number average molecular weight 1000, manufactured by Sanyo Chemical Industries, Ltd.) were added to the above container, and the contents of the container were mixed for 30 minutes using a chemical stirrer to obtain a polyol composition. The obtained polyol composition was used as the second liquid (main component).

[0101] [3] Polyurethane sealants and cured products Examples 1-4 and Comparative Examples 1-6 According to the formulation shown in Table 2, the first liquid (curing agent) and the second liquid (main component) were prepared to obtain a two-component curing type polyurethane sealant. Next, the first liquid (curing agent) and the second liquid (main component) were mixed to obtain a mixed composition.

[0102] Subsequently, the mixed composition was degassed, poured into a predetermined mold according to the evaluation method described later, and cured at 23°C for 168 hours to obtain a cured polyurethane sealant.

[0103] Table 2 shows the equivalent ratio (NCO / OH) of isocyanate groups (NCO) in the first solution to the hydroxyl groups (OH) in the second solution.

[0104] Furthermore, Table 2 shows the content ratio of inorganic fine particles (solids) per 100 parts by mass of hydrophobic polyol (parts by mass / 100 parts by mass of hydrophobic polyol), the content ratio of water per 100 parts by mass of inorganic fine particles (solids) (parts by mass / 100 parts by mass of inorganic fine particles (solids)), and the content ratio of polyethylene glycol per 100 parts by mass of inorganic fine particles (solids) (parts by mass / 100 parts by mass of inorganic fine particles (solids)).

[0105] [4] Rating The physical properties of the polyurethane sealant and the cured product were evaluated using the following method. The results are shown in Table 2.

[0106] (1) Viscosity The first and second liquids were mixed for 3 minutes under conditions of 25°C, and the viscosity at 25°C was measured using a BH-type viscometer (manufactured by Toki Sangyo Co., Ltd., rotation speed 2 rpm, rotor No. 7).

[0107] (2) Dripping properties (slump test) The drip properties of polyurethane sealant were evaluated in accordance with JIS A1439-5-1 (2016). Specifically, a mixed composition was obtained by mixing the first and second liquids. The mixed composition was filled into a predetermined grooved container to obtain a test specimen (width 20 mm × depth 10 mm × length 150 mm). The grooved container and the test specimen were then suspended vertically and left to stand for 30 minutes. After that, the length (mm) of the test specimen hanging from the grooved container was measured as the slump value (initial).

[0108] Furthermore, the channel-shaped container and the test specimen were left standing under conditions of 50°C while suspended vertically. After 14 days, the length (mm) of the test specimen hanging from the channel-shaped container was measured as the slump value (50°C × 14 days), and after 28 days, the length (mm) of the test specimen hanging from the channel-shaped container was measured as the slump value (50°C × 28 days).

[0109] (3)Hardness The first liquid and the second liquid were mixed to obtain a mixed composition. The mixed composition was filled into a designated container and cured at 23°C for 168 hours to obtain a cured product (50 mm long x 50 mm wide x 15 mm thick).

[0110] Next, the Asker C hardness of the cured material was measured in accordance with JIS K 7312 (1996).

[0111] The Asker C hardness of the cured material was evaluated according to the following criteria. A: Asker C hardness 3 or higher B: Asker C hardness 1 or more and less than 3 C: Asker C hardness less than 1

[0112] (4) Elongation at break and maximum tensile stress The first liquid and the second liquid were mixed to obtain a mixed composition. The mixed composition was filled into a designated container and cured at 23°C for 168 hours to obtain a cured product (260 mm long x 260 mm wide x 2 mm thick).

[0113] Next, the hardened material was punched out in accordance with JIS K 6251 (2017) to obtain a No. 3 dumbbell-shaped test specimen.

[0114] Then, using a universal tensile testing apparatus (crosshead speed 500 mm / min), the samples were subjected to tensile testing, and the elongation at which the sample fractured (elongation at fracture) was measured. In addition, the maximum tensile stress during the period leading up to the sample's fracture (maximum tensile stress) was measured.

[0115] The elongation at break of the cured material was evaluated according to the following criteria. A: Breaking elongation of 600% or more B: Elongation at break is between 300% and 600% C: Elongation at break is less than 300%

[0116] The maximum tensile stress of the cured material was evaluated according to the following criteria. A: Maximum tensile stress is 80 kN / m 2 That's all. B: Maximum tensile stress is 40 kN / m 2 More than 80kN / m 2 less than C: Maximum tensile stress is 40 kN / m 2 less than

[0117] [Table 1]

[0118] [Table 2]

[0119] Details of the abbreviations in the table are as follows. Polybutadiene polyol: Hydrophobic polyol, trade name Poly bd R-45 HT, number average molecular weight 2800, hydroxyl value 46.6 mgKOH / g, manufactured by Idemitsu Petrochemical Co., Ltd. Mineral oil: Organic solvent, product name Fucol FR-LA, manufactured by Air Water Inc. Bisphenol-based antioxidant: Product name: Nocrack NS-30, manufactured by Ouchi Shinko Chemical Industry Co., Ltd., 2,2'-methylenebis(4-methyl-6-tert-butylphenol) Dithiocarbamate-based anti-aging agent: Product name: Noxellar PZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd., zinc dimethyldithiocarbamate. Black toner: Pigment, Product name SKT 6-0613 Black, Manufactured by Saika Chemical Industry Co., Ltd. Organotin compound: Urethane catalyst, trade name Neostan U-100, manufactured by Nitto Kasei Co., Ltd. Inorganic microparticles: Colloidal silica, product name Aerosil #200, manufactured by Nippon Aerosil Co., Ltd. Polyethylene glycol: Product name PEG-1000, number average molecular weight 1000, manufactured by Sanyo Chemical Industries, Ltd.

Claims

1. It contains a polyisocyanate component, a polyol component, and a thixotrope, The aforementioned polyol component contains a hydrophobic polyol, The aforementioned thixotrope contains inorganic fine particles, water, and polyethylene glycol. The content ratio of the inorganic fine particles is 30.0 parts by mass or more per 100 parts by mass of the hydrophobic polyol. The water content is 1.0 part by mass or more and 3.0 parts by mass or less per 100 parts by mass of the inorganic fine particles. The polyurethane sealing material has a polyethylene glycol content of 10.0 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of the inorganic fine particles.

2. The polyurethane sealing material according to claim 1, wherein the hydrophobic polyol contains a polybutadiene polyol.

3. The aforementioned polyisocyanate component contains an isocyanate group-terminated prepolymer, The isocyanate-terminated prepolymer contains a reaction product of a raw material polyisocyanate and a raw material polyol. The polyurethane sealing material according to claim 1, wherein the raw material polyisocyanate contains diphenylmethane diisocyanate.

4. Furthermore, the polyurethane sealing material according to claim 1 contains an organic solvent.

5. The polyurethane sealing material according to claim 4, wherein the organic solvent contains mineral oil.

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