Resin composition

Abstract

To provide a polyisocyanate composition excellent in compatibility to a main agent under a low temperature environment of about -10°C, and excellent in flexibility at a low temperature of about -10°C and at normal temperature of about 23°C when formed into a coating film.SOLUTION: A polyisocyanate composition is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanate and alicyclic diisocyanate, polycaprolactone polyol (A) and polyether polyol (B); polypropylene glycol of 20 pts.mass or larger is contained for 100 pts.mass of the polyether polyol (B).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyisocyanate composition and a resin composition.

Background Art

[0002] In recent years, regarding curable polyurethanes, in order to achieve coating film physical properties that cannot be solved by conventional curing agents, there has been an increasing market need for higher quality and performance of curing agents. In particular, in coating films, adhesives, adhesives, sealants, etc. where the final physical properties are exhibited by curing, further development is required because the performance derived from the curing agent greatly contributes. In particular, there is a tendency in the market flow to require high flexibility of the composition after curing.

[0003] Patent Documents 1 and 2 disclose polyisocyanate compositions modified with polyester polyol or polyether polyol. It is disclosed that the coating film formed by blending the composition is excellent in stretchability and flex resistance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] There is a need for a polyisocyanate composition that can provide a coating film having better flexibility at low temperatures of about -10°C, i.e., in a more severe environment, than the polyisocyanate compositions described in Patent Documents 1 and 2.

[0006] The present invention has been made in view of the above circumstances, and provides a polyisocyanate composition that has good compatibility with a main agent in a low-temperature environment of about -10°C and is excellent in flexibility at a low temperature of about -10°C and a normal temperature of about 23°C when formed into a coating film. Further, a resin composition using the polyisocyanate composition is provided.

Means for Solving the Problems

[0007] That is, the present invention includes the following aspects. (1) A resin composition comprising a polyisocyanate and Acrylic a polyol, wherein the polyisocyanate is derived from at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B); the polyether polyol (B) contains 20 parts by mass or more of polypropylene glycol with respect to 100 parts by mass of the polyether polyol (B); the average number of hydroxyl functional groups of the polycaprolactone polyol (A) is 3, the number average molecular weight of the polycaprolactone polyol (A) is 500 or more and 1500 or less; the number average molecular weight of the polyether polyol (B) is 1000 or more and 7000 or less; the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polycaprolactone polyol (A) and the polyether polyol (B) is 2 or more and 10 or less, and the resin composition is an adhesive composition. (2) The resin composition according to (1), wherein in the polyether polyol (B), the mass ratio of polytetramethylene ether glycol to the polypropylene glycol is 0 / 100 or more and 60 / 40 or less. (3) The resin composition according to (1) or (2), wherein the mass ratio of the polycaprolactone polyol (A) to the polyether polyol (B) is 10 / 90 or more and 90 / 10 or less.

Effects of the Invention

[0008] According to the polyisocyanate composition of the above aspect, it has good compatibility with the main agent in a low-temperature environment of about -10°C, and can provide a polyisocyanate composition that is excellent in flexibility at a low temperature of about -10°C and a normal temperature of about 23°C when formed into a coating film. The resin composition of the above aspect contains the polyisocyanate composition and is excellent in flexibility at a low temperature of about -10°C and a normal temperature of about 23°C when formed into a coating film.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be variously modified without departing from its gist.

[0010] In this specification, "polyol" means a compound having two or more hydroxy groups (-OH) in one molecule. Also, in this specification, "polyisocyanate" means a reactant in which a plurality of monomer compounds having two or more isocyanate groups (-NCO) are bonded. Also, in this specification, unless otherwise specified, "(meth)acryl" includes methacryl and acryl, and "(meth)acrylate" includes methacrylate and acrylate.

[0011] ≪Polyisocyanate Composition≫ The polyisocyanate composition of this embodiment is derived from a diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B). That is, the polyisocyanate composition of this embodiment is a reaction product of a diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B), and contains a polyisocyanate modified with a polycaprolactone polyol (A) and a polyether polyol (B). The diisocyanate is at least one selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate. In the polyisocyanate composition of this embodiment, it contains 20 parts by mass or more of polypropylene glycol with respect to 100 parts by mass of the polyether polyol (B).

[0012] As described above, the polyisocyanate composition of this embodiment uses two different polyols and contains polypropylene glycol as the polyether polyol (B), so it exhibits higher flexibility than before. Specifically, it has good compatibility with the main agent in a low-temperature environment of about -10°C, and a coating film excellent in flexibility at a low temperature of about -10°C and a normal temperature of about 23°C can be obtained.

[0013] Next, each component of the polyisocyanate composition of this embodiment will be described in detail below.

[0014] <Polyisocyanate> The polyisocyanate composition of this embodiment may be a polyisocyanate having all the structural units derived from a diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B) in one molecule, or may be a mixture of polyisocyanates having structural units derived from at least one or more selected from the group consisting of a diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B) in one molecule.

[0015] The polyisocyanate can have at least one or more structures selected from the group consisting of allophanate structure, uretdione structure, iminooxadiazinedione structure, isocyanurate structure, urea structure, urethane structure, and biuret structure. Among them, it preferably has at least one structure selected from the group consisting of urethane structure, allophanate structure, biuret structure, urea structure, and isocyanurate group.

[0016] [Diisocyanate] The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanate and alicyclic diisocyanate.

[0017] Examples of the aliphatic diisocyanate include, but are not limited to, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato) hexanoate, 1,6-diisocyanatohexane (hereinafter sometimes abbreviated as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, etc. These aliphatic diisocyanates may be used alone or in combination of two or more.

[0018] Examples of the alicyclic diisocyanate include, but are not limited to, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter sometimes abbreviated as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl-1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes abbreviated as "IPDI"), 4,4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes abbreviated as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, etc. These alicyclic diisocyanates may be used alone or in combination of two or more.

[0019] These aliphatic diisocyanates and alicyclic diisocyanates may each be used alone, or two or more of the aliphatic diisocyanates and alicyclic diisocyanates may be used in combination.

[0020] Among them, as the diisocyanate, HDI, IPDI, hydrogenated XDI, or hydrogenated MDI is preferable, HDI or IPDI is more preferable, and HDI is even more preferable.

[0021] In the production of the polyisocyanate, in addition to the above-described diisocyanates, isocyanate monomers as shown below may further be used. (1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolylene diisocyanate (TDI), xylylene diisocyanate, m-tetramethylxylylene diisocyanate (TMXDI). (2) Triisocyanates such as 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter sometimes referred to as "NTI"), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as "HTI"), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter sometimes referred to as "GTI"), lysine triisocyanate (hereinafter sometimes referred to as "LTI").

[0022] <Polycaprolactone polyol (A)> The polycaprolactone polyol is not particularly limited, but specifically, it can be obtained by ring-opening polymerization of ε-caprolactone using a dihydric or higher alcohol, preferably a trihydric alcohol, as an initiator in the presence of a catalyst. Such initiators are not particularly limited, but specifically, dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, and neopentyl glycol; trihydric alcohols such as trimethylolpropane and glycerin are used. In terms of obtaining a low-viscosity polyisocyanate, a branched polycaprolactone polyol is preferred. Such a polycaprolactone polyol can be obtained by using an alcohol with a valence of 3 or higher as an initiator.

[0023] The catalyst is not particularly limited, but specifically, organotitanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate; tin compounds such as tin octylate, dibutyltin oxide, dibutyltin laurate, stannous chloride, and stannous bromide are used.

[0024] The ring-opening polymerization of ε-caprolactone is not particularly limited, but specifically, in a nitrogen gas atmosphere, the molar ratio of ε-caprolactone to the above initiator is set so as to obtain a desired molecular weight, and further, a catalyst is added in an amount of 0.1 mass ppm or more and 100 mass ppm or less based on ε-caprolactone, and the reaction is carried out at a temperature of 150°C or higher and 200°C or lower for 4 hours or more and 10 hours or less.

[0025] In the polyisocyanate, urethane groups are formed by the reaction of the hydroxyl groups of the polycaprolactone polyol (A) and the isocyanate groups of the diisocyanate.

[0026] The average number of hydroxyl functional groups of the polycaprolactone polyol (A) is preferably 2.0 or more and 8.0 or less, more preferably 2 or more and 6 or less, still more preferably 2 or more and 5 or less, and particularly preferably 3. Here, the average number of hydroxyl functional groups of the polycaprolactone polyol (A) is the number of hydroxyl groups present in one molecule of the polycaprolactone polyol (A).

[0027] The number average molecular weight of the polycaprolactone polyol (A) is preferably 500 or more and 1500 or less, more preferably 600 or more and 1400 or less, still more preferably 700 or more and 1300 or less, and particularly preferably 850 or more and 1250 or less. When the number average molecular weight of the polycaprolactone polyol (A) is within the above range, the flexibility of the resulting coating film at low temperature and normal temperature is excellent. The number average molecular weight Mn of the polycaprolactone polyol (A) is, for example, the number average molecular weight based on polystyrene measured by gel permeation chromatography (GPC).

[0028] Examples of commercially available polycaprolactone polyols include "Placcel 305" (number average molecular weight 550), "Placcel 308" (number average molecular weight 850), "Placcel 309" (number average molecular weight 900), "Placcel 312" (number average molecular weight 1250), "Placcel 205" (number average molecular weight 530), "Placcel 210" (number average molecular weight 1000) manufactured by Daicel Corporation; "Polyolite OD-X-2735" (number average molecular weight 500), "Polyolite OD-X-2586" (number average molecular weight 850), "Polyolite OD-X-2588" (number average molecular weight 1250), etc. manufactured by DIC Corporation.

[0029] <Polyether polyol (B)> The polyether polyol (B) contains polypropylene glycol (PPG, also referred to as polyoxypropylene polyol). In the polyisocyanate composition of the present embodiment, the content of PPG with respect to 100 parts by mass of the polyether polyol (B) is 20 parts by mass or more, preferably 40 parts by mass or more, more preferably 50 parts by mass or more, still more preferably 55 parts by mass or more, particularly preferably 60 parts by mass, and most preferably 100 parts by mass. When the content of PPG is at least the above lower limit value, the compatibility with the main agent under low temperature environment can be made better.

[0030] Although the polypropylene glycol is not particularly limited, specifically, polyoxypropylene diol or triol; a so-called Pluronic (registered trademark) type polyoxypropylene diol or triol obtained by addition polymerization of ethylene oxide to the terminal of polyoxypropylene diol or triol; polyoxypropylene polyoxyethylene polymer diol or triol, etc. may be mentioned. Among these, the Pluronic (registered trademark) type polyoxypropylene diol or triol is preferable because of its excellent reactivity with diisocyanate.

[0031] As a method for producing polypropylene glycol, a method of adding propylene oxide, ethylene oxide, etc. alone or as a mixture to an initiator and a catalyst can be mentioned. The initiator is not particularly limited, but specifically, polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines, or mixtures thereof can be mentioned. More specifically, dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A; trihydric alcohols such as glycerin, trimethylolpropane; diamines such as ethylenediamine; and mixtures thereof can be mentioned. Further, the catalyst is not particularly limited, but specifically, hydroxides such as lithium, sodium, potassium; strongly basic catalysts such as alcoholates, alkylamines; composite metal complexes such as metal porphyrins, composite metal cyanide complexes, complexes of metals and chelating agents having three or more coordination sites, zinc hexacyanocobaltate complexes, etc. can be mentioned. In addition, a method of dehydrating and condensing polyhydric alcohols to obtain polypropylene glycol can be mentioned.

[0032] Examples of commercially available polypropylene glycols include "Excenol 510" (polyoxypropylene diol with terminal EO addition, number average molecular weight 4000), "Excenol 840" (polyoxypropylene triol with terminal EO addition, number average molecular weight 6500), "Excenol 1020" (polyoxypropylene diol with terminal EO addition, number average molecular weight 1000), "Excenol 2020" (polyoxypropylene diol with terminal EO addition, number average molecular weight 2000), etc., manufactured by Asahi Glass Co., Ltd.

[0033] In addition to polypropylene glycol, polyether polyol (B) can include other polyether polyols. Although not particularly limited, examples of other polyether polyols include polyether polyols obtained by adding a single or a mixture of alkylene oxides to a single or a mixture of polyhydric alcohols using an alkali metal hydroxide or a strongly basic catalyst, polyether polyols obtained by reacting an alkylene oxide with a polyamine compound, and so-called polymer polyols obtained by polymerizing acrylamide or the like using the above polyether as a medium. Examples of alkali metals include lithium, sodium, potassium, etc. Examples of strongly basic catalysts include alcoholates, alkylamines, etc. Although not particularly limited, examples of polyhydric alcohols include at least one polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin. Examples of alkylene oxides include ethylene oxide, butylene oxide, cyclohexene oxide, styrene oxide, etc. Examples of polyamine compounds include ethylenediamines, etc.

[0034] Among these, as other polyether polyols, polytetramethylene ether glycol (PTMG, also referred to as polyoxytetramethylene polyol) is preferred.

[0035] Polytetramethylene ether glycol is produced by cationic polymerization of tetrahydrofuran using a catalyst, etc. The catalyst to be used is not particularly limited, but specifically, acetic anhydride - perchloric acid, fluorosulfonic acid, or fuming sulfuric acid, etc. are used. For example, the production of polyoxytetramethylene glycol is not particularly limited, but specifically, usually, fluorosulfonic acid of approximately 1% by mass or more and 30% by mass or less is added to the raw material tetrahydrofuran, and the reaction is carried out under the conditions of reacting at a temperature of 5°C or more and 65°C or less for several minutes or more and several tens of hours or less. Also, in the same manner as the production method of polypropylene glycol described above, it can be obtained by using a polyhydric alcohol, etc. as an initiator and using a strongly basic catalyst, etc. to add butylene oxide. Furthermore, the molecular weight of the produced polytetramethylene ether glycol is adjusted by changing the polymerization temperature, polymerization time, catalyst usage amount, etc.

[0036] Examples of commercially available polytetramethylene ether glycol include products with the trade names "PTMG1000" (number average molecular weight 1000), "PTMG2000" (number average molecular weight 2000), "PTMG3000" (number average molecular weight 2900), "PTMG4000" (number average molecular weight 4000), etc. manufactured by Mitsubishi Chemical Corporation.

[0037] In the polyether polyol (B), the mass ratio of polytetramethylene ether glycol to polypropylene glycol (mass ratio of PTMG / PPG) is preferably 0 / 100 or more and 80 / 20 or less, more preferably 0 / 100 or more and 60 / 40 or less, still more preferably 0 / 100 or more and 50 / 50 or less, and particularly preferably 0 / 100 or more and 45 / 55 or less. When the mass ratio of PTMG / PPG is within the above range, the compatibility with the main agent under a low - temperature environment can be made better.

[0038] The number average molecular weight of the polyether polyol (B) is preferably 1000 or more and 7000 or less, more preferably 2000 or more and 7000 or less, still more preferably 3000 or more and 6700 or less, and particularly preferably 4000 or more and 6500 or less. When the number average molecular weight of the polyether polyol (B) is within the above range, the flexibility of the resulting coating film at low temperature and normal temperature is excellent. The number average molecular weight Mn of the polyether polyol (B) is, for example, the number average molecular weight based on polystyrene by GPC measurement. Further, when two or more polyether polyols (B) are mixed and used, the number average molecular weight of the mixture is calculated.

[0039] In the polyisocyanate composition of the present embodiment, the mass ratio of the polycaprolactone polyol (A) to the polyether polyol (B) (mass ratio of (A) / (B)) is preferably 10 / 90 or more and 90 / 10 or less, more preferably 15 / 85 or more and 85 / 15 or less, and still more preferably 18 / 82 or more and 83 / 17 or less. When the mass ratio of (A) / (B) is equal to or higher than the above lower limit value, the compatibility with the main agent in a low temperature environment can be made better. On the other hand, when it is equal to or lower than the above upper limit value, a coating film excellent in flexibility at low temperature and normal temperature can be obtained. The mass ratio of (A) / (B) can be calculated, for example, from the blending amounts of the respective polyols.

[0040] <Method for producing polyisocyanate composition> The polyisocyanate is obtained by reacting the above diisocyanate with the polycaprolactone polyol (A) and the polyether polyol (B). Hereinafter, the polycaprolactone polyol (A) and the polyether polyol (B) may be collectively referred to as polyol in some cases.

[0041] The polycaprolactone polyol (A) and the polyether polyol (B) can be used alone or as a mixture, respectively. When used as a mixture, they may be mixed before reacting with the diisocyanate, or each polyol may be reacted with the diisocyanate alone to form a polyisocyanate and then mixed. That is, as a method for producing a polyisocyanate composition, for example, a method of simultaneously reacting a diisocyanate, a polycaprolactone polyol (A), and a polyether polyol (B) to obtain a polyisocyanate composition; a method of mixing a reaction product of a diisocyanate and a polycaprolactone polyol (A) with a reaction product of a diisocyanate and a polyether polyol (B) to obtain a polyisocyanate composition; a method of reacting a diisocyanate with a polycaprolactone polyol (A) or a polyether polyol (B) and then further reacting the remaining polyol to obtain a polyisocyanate composition, etc. can be mentioned.

[0042] The compounding amounts of the polycaprolactone polyol (A) and the polyether polyol (B) are preferably compounded so that the mass ratio of the polycaprolactone polyol (A) to the polyether polyol (B) is within the above range.

[0043] The reaction between the polyol and the diisocyanate is carried out as follows. The reaction temperature is usually from room temperature (about 23°C) to 200°C, preferably from 80°C to 120°C. If the reaction temperature is at or above the lower limit value, the reaction time will be shorter. On the other hand, if it is at or below the upper limit value, an increase in the viscosity of the polyisocyanate due to undesirable side reactions can be more avoided, and coloring of the produced polyisocyanate can also be more avoided.

[0044] The reaction may be carried out without a solvent, or may be carried out using any solvent inert to the isocyanate group. Also, if necessary, a known catalyst may be used to promote the reaction between the isocyanate group and the hydroxyl group.

[0045] In the reaction, the molar ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups of the polycaprolactone polyol (A) and the polyether polyol (B) (molar ratio of hydroxyl group / isocyanate group) is preferably 2 or more and 10 or less, more preferably 3 or more and 9 or less, and even more preferably 4 or more and 8 or less. When the molar ratio of hydroxyl group / isocyanate group is at least the above lower limit value, an increase in the viscosity of the polyisocyanate due to the sequential addition reaction between the diisocyanate and the polyol can be more avoided. On the other hand, when it is at most the above upper limit value, the productivity becomes better.

[0046] At the end of the reaction, the unreacted diisocyanate in the reaction mixture is recovered by a known method such as a thin-film distillation apparatus or solvent extraction. If the residual amount of the unreacted diisocyanate is small, odors, toxicity, irritation, etc. caused by the diisocyanate during thermosetting can be more avoided.

[0047] <Physical properties of the polyisocyanate composition> The isocyanate group content (NCO group content) of the polyisocyanate composition of this embodiment is preferably 3% by mass or more and 8% by mass or less, more preferably 3.1% by mass or more and 7.5% by mass or less, and even more preferably 3.3% by mass or more and 7.3% by mass or less, based on the total mass of the polyisocyanate composition in a state substantially free of solvents and diisocyanates. The NCO group content can be determined, for example, by reacting the isocyanate groups of the polyisocyanate composition with an excessive amine (such as dibutylamine), and back-titrating the remaining amine with an acid such as hydrochloric acid.

[0048] ≪Resin composition≫ The resin composition of this embodiment contains the above-described polyisocyanate composition as a curing agent component and a polyol as a main agent component.

[0049] By containing the above polyisocyanate composition as a curing agent component, the resin composition of this embodiment can obtain a coating film excellent in flexibility at a low temperature of about -10°C and a normal temperature of about 23°C.

[0050] The resin composition of the present embodiment can be used, for example, in architectural paints, automotive paints, automotive repair paints, plastic paints, adhesives, binders, building materials, household water-based paints, other coating agents, sealing agents, inks, casting materials, elastomers, foams, plastic raw materials, fiber treatment agents, etc. Among them, the resin composition of the present embodiment is preferably used as an adhesive composition because it has good flexibility at low and normal temperatures when formed into a coating film.

[0051] Next, each constituent component included in the resin composition of the present embodiment will be described in detail below.

[0052] <Polyol> Specific examples of the polyol include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, epoxy resins, fluorine-containing polyols, acrylic polyols, and the like. Among them, the polyol is preferably an acrylic polyol.

[0053] [Aliphatic hydrocarbon polyol] Examples of the aliphatic hydrocarbon polyol include terminal-hydroxylated polybutadiene and its hydrogenated products.

[0054] [Polyether polyol] Examples of the polyether polyol include those obtained by using any of the following methods (1) to (3). (1) Polyether polyols or polytetramethylene ether glycols obtained by adding a single or a mixture of alkylene oxides to a single or a mixture of polyhydric alcohols. (2) Polyether polyols obtained by reacting a polyfunctional compound with an alkylene oxide. (3) So-called polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyol obtained in (1) or (2) as a medium. Examples of the polyhydric alcohol include glycerin, propylene glycol, and the like. Examples of the alkylene oxide include ethylene oxide, propylene oxide, and the like. Examples of the polyfunctional compound include ethylenediamine, ethanolamine, and the like.

[0055] [Polyester polyol] Examples of the polyester polyol include, for example, any of the following (1) or (2) polyester polyols. (1) A polyester polyol resin obtained by a condensation reaction of a dibasic acid alone or a mixture of two or more kinds thereof and a polyhydric alcohol alone or a mixture of two or more kinds thereof. (2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with a polyhydric alcohol. Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, and the like. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, ethoxylated trimethylolpropane, and the like.

[0056] [Epoxy resin] Examples of the epoxy resin include epoxy resins such as novolac type epoxy resin, β-methyl epichlorohydrin type epoxy resin, cyclic oxirane type epoxy resin, glycidyl ether type epoxy resin, glycol ether type epoxy resin, epoxy type aliphatic unsaturated compound, epoxidized fatty acid ester, ester type polyvalent carboxylic acid, aminoglycidyl type epoxy resin, halogenated type epoxy resin, resorcin type epoxy resin, and resins obtained by modifying these epoxy resins with amino compounds, polyamide compounds, etc.

[0057] [Fluorine-containing polyol] Examples of the fluorine-containing polyol include copolymers such as fluoroolefin, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl ester, etc. disclosed in Reference 1 (Japanese Patent Laid-Open No. 57-34107), Reference 2 (Japanese Patent Laid-Open No. 61-275311), etc.

[0058] [Acrylic polyol] The acrylic polyol is obtained, for example, by polymerizing a polymerizable monomer having one or more active hydrogens in one molecule, or by copolymerizing a polymerizable monomer having one or more active hydrogens in one molecule and, if necessary, another monomer copolymerizable with the polymerizable monomer.

[0059] Examples of the polymerizable monomer having one or more active hydrogens in one molecule include those shown in the following (i) to (iii). These may be used alone or in combination of two or more. (i) Acrylic acid esters having active hydrogens such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate. (ii) Methacrylic acid esters having active hydrogens such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate. (iii) (Meth)acrylic acid esters having polyvalent active hydrogens such as monoacrylic acid esters or monomethacrylic acid esters of glycerin, and monoacrylic acid esters or monomethacrylic acid esters of trimethylolpropane.

[0060] Examples of other monomers copolymerizable with the polymerizable monomer include those shown in the following (i) to (v). These may be used alone or in combination of two or more. (i) Acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate. (ii) Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, glycidyl methacrylate. (iii) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid. (iv) Unsaturated amides such as acrylamide, N-methylolacrylamide, diacetoneacrylamide. (v) Styrene, vinyltoluene, vinyl acetate, acrylonitrile, etc.

[0061] In addition, examples include acrylic polyols obtained by copolymerizing polymerizable ultraviolet stability monomers disclosed in Reference 3 (Japanese Patent Laid-Open No. 1-261409) and Reference 4 (Japanese Patent Laid-Open No. 3-006273).

[0062] Specific examples of the polymerizable ultraviolet stability monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 2-hydroxy-4-(3-methacryloxy-2-hydroxypropoxy)benzophenone, etc.

[0063] For example, an acrylic polyol can be obtained by solution-polymerizing the above monomer components in the presence of a radical polymerization initiator such as a known peroxide or azo compound, and diluting with an organic solvent or the like as necessary.

[0064] When obtaining an aqueous-based acrylic polyol, it can be produced by a known method such as solution-polymerizing an olefinically unsaturated compound and converting it to an aqueous layer, or emulsion polymerization. In that case, water solubility or water dispersibility can be imparted by neutralizing an acidic moiety such as a carboxylic acid-containing monomer like acrylic acid or methacrylic acid, or a sulfonic acid-containing monomer, with an amine or ammonia.

[0065] [Isocyanate group / hydroxyl group] The molar ratio of the isocyanate group of the polyisocyanate composition to the hydroxyl group of the polyol contained in the resin composition of the present embodiment (molar ratio of isocyanate group / hydroxyl group) is determined by the physical properties of the required resin film, but is usually 0.01 or more and 22.5 or less.

[0066] <Other components> The resin composition of the present embodiment may further contain other additives. Examples of other additives include, for example, curing agents other than polyisocyanate compositions that can react with polyols, curing catalysts, solvents, pigments (extender pigments, coloring pigments, metallic pigments, etc.), photoinitiators, ultraviolet absorbers, light stabilizers, radical stabilizers, anti-yellowing agents that suppress coloring during the baking process, coating surface modifiers, flow regulators, pigment dispersants, defoaming agents, thickeners, film-forming aids, and the like.

[0067] Examples of the curing agent include, for example, melamine resins, urea resins, epoxy group-containing compounds or resins, carboxy group-containing compounds or resins, acid anhydrides, alkoxysilane group-containing compounds or resins, hydrazide compounds, and the like.

[0068] The curing catalyst may be a basic compound or a Lewis acidic compound. Examples of the basic compound include metal hydroxides, metal alkoxides, metal carboxylates, metal acetylacetinates, hydroxides of onium salts, onium carboxylates, halides of onium salts, metal salts of active methylene compounds, onium salts of active methylene compounds, aminosilanes, amines, phosphines, etc. Preferred examples of the onium salt include ammonium salts, phosphonium salts, or sulfonium salts. Examples of the Lewis acidic compound include organotin compounds, organozinc compounds, organotitanium compounds, organozirconium compounds, etc.

[0069] Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene glycol dimethyl ether, methyl ethyl ketone, acetone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, iso-propanol, 1-propanol, iso-butanol, 1-butanol, tert-butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, iso-pentane, hexane, iso-hexane, cyclohexane, solvent naphtha, mineral spirit, etc. These solvents may be used alone or in combination of two or more.

[0070] In addition, as pigments (extender pigments, coloring pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, radical stabilizers, anti-yellowing agents for suppressing coloring during the baking process, coating surface modifiers, flow modifiers, pigment dispersants, defoaming agents, thickeners, and film-forming aids, known ones can be appropriately selected and used.

[0071] <Method for manufacturing resin composition> The resin composition of this embodiment can be manufactured by a conventionally known method. When the resin composition of this embodiment is an adhesive composition, for example, a melting kneading method using a general mixer such as a Banbury mixer, a single-screw extruder, a twin-screw extruder, a kneader, a multi-screw extruder, etc., a method in which each component is dissolved or dispersed and mixed and then coated on a base film by a coater or the like and then the solvent is removed by heating, etc. are used.

[0072] The resin composition of this embodiment may be foamed in order to achieve the effects of weight reduction, softening, and improvement of adhesion. As the foaming method, there are a chemical method, a physical method, the use of a heat-expandable microballoon, etc. By adding a chemical foaming agent such as an inorganic foaming agent or an organic foaming agent or a physical foaming agent, or by adding a heat-expandable microballoon, etc., bubbles can be distributed inside the material.

[0073] In addition, by adding a hollow filler (already expanded balloon), weight reduction, softening, and improvement of adhesion may be achieved.

[0074] When the resin composition of this embodiment is an adhesive composition, an adhesion-imparting resin may be added to adjust the adhesive force and cohesive force. Examples of the adhesion-imparting resin include rosin-based adhesion-imparting resins, terpene-based adhesion-imparting resins, petroleum-based adhesion-imparting resins, styrene-based adhesion-imparting resins, etc. These adhesion-imparting resins may be used alone or in combination of two or more. Also, the softening point of the adhesion-imparting resin is preferably 90°C or higher and 160°C or lower.

Examples

[0075] Hereinafter, the present embodiment will be described in more detail based on examples and comparative examples, but the present embodiment is not limited in any way by the following examples. In the following, Example 8 is regarded as a reference example.

[0076] <Test Items> Regarding the polyisocyanate compositions produced in the examples and comparative examples, the measurement of each physical property and each evaluation were carried out according to the methods shown below.

[0077] [Physical Property 1] (Isocyanate Group (NCO) Content) First, 2 g or more and 3 g or less of the measurement sample was precisely weighed into a flask (W g). Next, 20 mL of toluene was added to dissolve the measurement sample. Then, 20 mL of a toluene solution of 2N di-n-butylamine was added, and after mixing, it was left at room temperature for 15 minutes. Then, 70 mL of isopropyl alcohol was added and mixed. Then, this solution was titrated with a 1N hydrochloric acid solution (factor F) using an indicator. The obtained titration value was taken as V2 mL. Next, without the polyisocyanate sample, the obtained titration value was taken as V1 mL. Then, the isocyanate group (NCO) content (NCO%) (mass%) of the polyisocyanate was calculated from the following formula.

[0078] Isocyanate Group (NCO) Content (mass%) = (V1 - V2) × F × 42 / (W × 1000) × 100

[0079] [Physical Property 2] (Number Average Molecular Weight) The number average molecular weight is the number average molecular weight based on polystyrene by gel permeation chromatography (GPC) measurement using the following apparatus.

[0080] (Measurement Conditions) Apparatus: HLC - 802A manufactured by Tosoh Corporation Column: G1000HXL × 1 piece manufactured by Tosoh Corporation G2000HXL × 1 piece G3000HXL × 1 piece Carrier: Tetrahydrofuran Detection Method: Differential Refractometer

[0081] [Preparation of Resin Composition] Each polyisocyanate composition and an acrylic polyol (manufactured by Allnex, trade name "Setalux1152") were mixed so that the molar ratio of isocyanate groups to hydroxyl groups was 1.0, and then diluted with butyl acetate so that the solid content was 50% by mass. Next, a tin catalyst (manufactured by Nitto Kasei Co., Ltd., trade name "Neo Stan U-100") was further mixed in an amount of 300 mass ppm based on the solid content to obtain each resin composition.

[0082] [Evaluation 1] (Compatibility with the Main Agent) Each resin composition immediately after preparation was held in an environment of -10°C for 5 days. The state of the coating solution was visually observed and evaluated according to the following evaluation criteria.

[0083] (Evaluation Criteria) ◎: Transparent and uniform △: Slightly turbid in part ×: Turbid throughout

[0084] [Preparation of Coating Film] Each resin composition was applied onto a polypropylene plate to a film thickness of 30 μm and dried by heating at 120°C for 30 minutes. Then, it was dried in an environment of 23°C and 50% humidity for 1 day to prepare each coating film.

[0085] [Evaluation 2] (Elongation at Low Temperature) The prepared coating film was cut into strips to prepare test pieces. Next, the test pieces were mounted on a tensile testing machine (Tensilon universal testing machine) to have a length of 20 mm and a width of 10 mm, and the test was carried out at a test temperature of -10°C and a tensile speed of 20 mm / min, and the elongation percentage at break was measured. Based on the elongation at break, the evaluation was made according to the following evaluation criteria.

[0086] (Evaluation Criteria) ◎: Elongation at break is 150% or more ○: Elongation at break is 100% or more and less than 150% ×: Elongation at break is less than 100%

[0087] [Evaluation 3] (Low-temperature and low-stress property (stress at 20% elongation)) The prepared coating film was cut into strip shapes to prepare test pieces. Subsequently, the test pieces were mounted on a tensile testing machine (Tensilon universal testing machine) to have a length of 20 mm and a width of 10 mm, and the test was carried out at a test temperature of -10°C and a tensile speed of 20 mm / min. Based on the stress value at 20% elongation, the evaluation was performed according to the following evaluation criteria.

[0088] (Evaluation criteria) ◎: Less than 10 MPa ○: 10 MPa or more and less than 30 MPa ×: 30 MPa or more

[0089] [Evaluation 4] (Normal-temperature and low-stress property (stress at 75% elongation)) The prepared coating film was cut into strip shapes to prepare test pieces. Subsequently, the test pieces were mounted on a tensile testing machine (Tensilon universal testing machine) to have a length of 20 mm and a width of 10 mm, and the test was carried out at a test temperature of 23°C and a tensile speed of 20 mm / min. Based on the stress value at 75% elongation, the evaluation was performed according to the following evaluation criteria.

[0090] (Evaluation criteria) ◎: Less than 2 MPa ○: 2 MPa or more and less than 5 MPa ×: 5 MPa or more

[0091] (Manufacture of polyisocyanate composition) [Example 1] (Manufacture of polyisocyanate composition PA-a1) A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube, and a dropping funnel was purged with nitrogen. 1000 g of HDI and 496.0 g of a trifunctional polycaprolactone polyol (manufactured by DIC Corporation, trade name "OD-X2588", number average molecular weight 1250) were charged, and the temperature inside the reactor was maintained at 100 °C with stirring to allow the urethanization reaction to proceed. After filtering the reaction solution, unreacted HDI was removed using a thin-film evaporator to obtain a polyisocyanate precursor. 100.0 g of the polyisocyanate precursor was charged into a flask, and 57.0 g of polyoxypropylene diol (manufactured by AGC Inc., trade name "Excenol 510", number average molecular weight 4000) was charged. The temperature inside the reactor was maintained at 100 °C with stirring to allow the urethanization reaction to proceed, and a polyisocyanate composition PA-a1 was obtained.

[0092] [Examples 2 to 6] (Production of polyisocyanate compositions PA-a2 to PA-a6) Except for using the compositions shown in Table 1, each polyisocyanate composition was obtained in the same manner as in Example 1.

[0093] [Example 7] (Production of polyisocyanate composition PA-a7) A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube, and a dropping funnel was purged with nitrogen. 1000 g of HDI, 150.0 g of a trifunctional polycaprolactone polyol (manufactured by DIC Corporation, trade name "OD-X2735", number average molecular weight 500), 200.0 g of polytetramethylene ether glycol (manufactured by Mitsubishi Chemical Corporation, trade name "PTMG1000", number average molecular weight 1000), and 300.0 g of polyoxypropylene diol (manufactured by AGC Inc., trade name "Excenol 510", number average molecular weight 4000) were charged, and the temperature inside the reactor was maintained at 100 °C with stirring to allow the urethanization reaction to proceed. After filtering the reaction solution, unreacted HDI was removed using a thin-film evaporator to obtain a polyisocyanate composition PA-a6.

[0094] [Examples 8 and Comparative Examples 1 to 3] (Production of Polyisocyanate Compositions PA-a8 and PA-b1 to PA-b3) Except for having the compositions shown in Table 2, each polyisocyanate composition was obtained in the same manner as in Example 7.

[0095] Table 1 and Table 2 show the physical properties of each obtained polyisocyanate composition and the evaluation results using the method described above.

[0096] In Table 1 and Table 2, each abbreviation represents the following compound.

[0097] (Polycaprolactone Polyol (A)) A: Polycaprolactone polyol OD-X-2735: A trifunctional polycaprolactone polyol manufactured by DIC Corporation, number average molecular weight 500 OD-X-2586: A trifunctional polycaprolactone polyol manufactured by DIC Corporation, number average molecular weight 850 OD-X-2588: A trifunctional polycaprolactone polyol manufactured by DIC Corporation, number average molecular weight 1250

[0098] (Polyether Polyol (B)) B1: Polypropylene glycol Excenol510: A polyoxypropylene diol manufactured by AGC Inc., number average molecular weight 4000 Excenol840: A polyoxypropylene triol manufactured by AGC Inc., number average molecular weight 6500 Excenol1020: A polyoxypropylene diol manufactured by AGC Inc., number average molecular weight 1000

[0099] B2: Other polyether polyol PTMG1000: A polytetramethylene ether glycol manufactured by Mitsubishi Chemical Corporation, number average molecular weight 1000

[0100]

Table 1

[0101]

Table 2

[0102] The polyisocyanate compositions PA-a1 to PA-a8 (Examples 1 to 8), which are derived from diisocyanate, polycaprolactone polyol (A), and polyether polyol (B) and contain 20 parts by mass or more of polypropylene glycol with respect to 100 parts by mass of polyether polyol (B), had good compatibility with the main agent in a low-temperature environment of about -10°C, excellent elongation at break at a low temperature of about -10°C when formed into a coating film, and excellent low stress properties at a low temperature of about -10°C and a normal temperature of about 23°C.

[0103] In the polyisocyanate composition PA-b1 (Comparative Example 1), which is derived from diisocyanate and polycaprolactone polyol (A), the compatibility with the main agent in a low-temperature environment of about -10°C was good, but the elongation at break at a low temperature of about -10°C when formed into a coating film and the low stress properties at a low temperature of about -10°C and a normal temperature of about 23°C were poor. Further, in the polyisocyanate composition PA-b2 (Comparative Example 2), which is derived from diisocyanate, polycaprolactone polyol (A), and polyether polyol (B) that does not contain polypropylene glycol, the elongation at break at a low temperature of about -10°C when formed into a coating film and the low stress properties at a low temperature of about -10°C and a normal temperature of about 23°C were within the allowable range, but the compatibility with the main agent in a low-temperature environment of about -10°C was poor. Also, in the polyisocyanate composition PA-b3 (Comparative Example 3), which is derived from diisocyanate, polycaprolactone polyol (A), and polyether polyol (B) and contains less than 20 parts by mass (10 parts by mass) of polypropylene glycol with respect to 100 parts by mass of polyether polyol (B), the elongation at break at a low temperature of about -10°C when formed into a coating film and the low stress properties at a low temperature of about -10°C and a normal temperature of about 23°C were within the allowable range, but the compatibility with the main agent in a low-temperature environment of about -10°C was poor.

Industrial Applicability

[0104] According to the polyisocyanate composition of the present embodiment, it is possible to provide a polyisocyanate composition having good compatibility with the main agent in a low-temperature environment of about -10°C and excellent flexibility at a low temperature of about -10°C and a normal temperature of about 23°C when formed into a coating film.

Claims

1. A resin composition comprising: a polyisocyanate and an acrylic polyol, wherein the polyisocyanate is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a polycaprolactone polyol (A), and a polyether polyol (B); 20 parts by mass or more of polypropylene glycol with respect to 100 parts by mass of the polyether polyol (B); the average number of hydroxyl functional groups of the polycaprolactone polyol (A) is 3; the number average molecular weight of the polycaprolactone polyol (A) is 500 or more and 1500 or less; the number average molecular weight of the polyether polyol (B) is 1000 or more and 7000 or less; the molar ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups of the polycaprolactone polyol (A) and the polyether polyol (B) is 2 or more and 10 or less; and the resin composition is an adhesive composition.

2. The resin composition according to claim 1, wherein in the polyether polyol (B), the mass ratio of polytetramethylene ether glycol to polypropylene glycol is 0 / 100 or more and 60 / 40 or less.

3. The resin composition according to claim 1 or 2, wherein the mass ratio of the polycaprolactone polyol (A) to the polyether polyol (B) is 10 / 90 or more and 90 / 10 or less.

Images