Curable polyurethane resin composition

Abstract

Provided is a curable polyurethane resin composition that can provide a resin with even better physical properties such as elongation at break. [Solution] A one-component moisture-cure curable polyurethane resin composition containing a urethane prepolymer, a filler, a low-molecular-weight isocyanate compound, and a catalyst, wherein the low-molecular-weight isocyanate compound contains an aliphatic isocyanate component and an aromatic isocyanate component, the aliphatic isocyanate component contains an isocyanurate obtained by trimerizing an aliphatic isocyanate monomer, and the aromatic isocyanate component contains a carbodiimide-modified isocyanate monomer, and when 8.8% by weight of the total amount of the urethane prepolymer is taken as 100 parts by weight, the amount of the aliphatic isocyanate component is y parts by weight, the amount of the aromatic isocyanate component is x parts by weight, and x and y satisfy specific formulas 1) to 5).

Description

[Technical Field]

[0001] The present invention relates to a curable polyurethane resin composition. [Background technology]

[0002] Traditionally, automotive window glass has been attached to the body via a rubber gasket. However, because gaskets have a low ability to hold the glass in place during a collision, in recent years, methods have been adopted in which the window glass is bonded to the painted vehicle body without a rubber gasket. One example of a method for bonding window glass to a painted vehicle body without a rubber gasket is the direct glazing method, in which laminated glass is bonded to the body with an adhesive layer.

[0003] Direct glazing generally uses a one-component adhesive composition containing a urethane prepolymer. The present inventors previously proposed the technology described in Patent Documents 1 and 2 for one-component moisture-curing polyurethane compositions. The invention described in Patent Document 1 provides a one-component moisture-curing polyurethane composition that has a high shear modulus, excellent adhesion under high temperature and humidity conditions, and good storage stability. The invention described in Patent Document 2 is a further improvement of the invention described in Patent Document 1, and eliminates the problem of the composition solidifying inside the pump when pumping the composition, causing the pump to stop working. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 203750 [Patent Document 2] Patent No. 6708207 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the present inventors have found that there is room for further improvement in physical properties such as breaking elongation of the resins obtained by curing the one-component adhesive compositions described in Patent Documents 1 and 2. Therefore, an object of the present invention is to provide a curable polyurethane resin composition that can give resins with even better physical properties such as breaking elongation. [Means for solving the problem]

[0006] The present inventors have found that the above problems can be solved by more appropriately selecting the composition and amount of the isocyanate component contained in the curable polyurethane resin composition.

[0007] In order to achieve the above object, in one embodiment, the present invention has the following configuration. [1] A one-component moisture-curable curable polyurethane resin composition containing a urethane prepolymer, a filler, a low-molecular-weight isocyanate compound, and a catalyst, the low molecular weight isocyanate compound contains an aliphatic isocyanate component and an aromatic isocyanate component, the aliphatic isocyanate component contains an isocyanurate obtained by trimerizing an aliphatic isocyanate monomer, the aromatic isocyanate component comprises a carbodiimide-modified isocyanate monomer; When 8.8% by weight of the total amount of the urethane prepolymer is taken as 100 parts by weight, the amount of the aliphatic isocyanate component blended is y parts by weight, the amount of the aromatic isocyanate component blended is x parts by weight, and x and y are expressed by the following formula: 1)-20 / 7x+596 / 7≦y 2) y≦-2 / 9x+70 3) y≦-3x+143 4) x≦34 5) 24≦y A curable polyurethane resin composition that satisfies the above requirements. [2] The aliphatic isocyanate component is mainly composed of a trimer of hexamethylene diisocyanate, The curable polyurethane resin composition according to [1], wherein the aromatic isocyanate component is a carbodiimide-modified diphenylmethane diisocyanate as a main component. [3] A resin obtained by curing the curable polyurethane resin composition according to [1] or [2]. [Effects of the Invention]

[0008] The curable polyurethane resin composition of the present invention can provide a resin that is even more excellent in physical properties such as elongation at break. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram visually showing that each example satisfies the conditions of formulas 1) to 5), and each comparative example does not satisfy at least one of formulas 1) to 5).

[0010] The present invention will be described in detail below. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] As used herein, the term "major component" means that the component is present in an amount of 50% by weight or more, based on the total weight of the component containing the component. In other preferred embodiments, the component may be present in an amount of 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 99% by weight or more, based on the total weight of the component containing the component.

[0013] [Adhesive composition] <Urethane prepolymer> The urethane prepolymer contained in the composition of the present invention is a urethane prepolymer having an isocyanate group at its terminal. The urethane prepolymer may be, for example, a urethane prepolymer obtained by reacting a polyisocyanate with a compound (active hydrogen compound) having two or more active hydrogen-containing groups per molecule such that the isocyanate groups of the polyisocyanate are in excess relative to the active hydrogen-containing groups of the active hydrogen compound. The urethane prepolymer may contain 0.5 to 5 mass % of isocyanate groups at its molecular terminals, based on the total amount of the urethane prepolymer.

[0014] The polyisocyanate used in producing the urethane prepolymer may be a compound having two or more isocyanate groups in the molecule. Examples of the polyisocyanate used in producing the urethane prepolymer include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI; for example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1, Aromatic polyisocyanates such as 5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate; hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (H6XDI), dicyclohexylmethane diisocyanate (H 12 The polyisocyanates may be aliphatic polyisocyanates (including alicyclic polyisocyanates) such as MDI; carbodiimide-modified polyisocyanates thereof; or isocyanurate-modified polyisocyanates thereof.

[0015] The polyisocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred, and MDI is more preferred, because of their excellent curability.

[0016] The compound having two or more active hydrogen-containing groups per molecule (active hydrogen compound) used in producing the urethane prepolymer may be a compound having two or more active hydrogen groups per molecule. The active hydrogen compounds may be used alone or in combination of two or more. The active hydrogen-containing group may be, for example, a hydroxyl (OH) group, an amino group, or an imino group. The active hydrogen compound may be, for example, a polyol compound having two or more hydroxyl (OH) groups per molecule. Among these, polyol compounds are preferred.

[0017] The polyol compound used in producing the urethane prepolymer is a compound having two or more hydroxy groups. The polyol compound may be, for example, polyether polyol; polyester polyol; polymer polyol having a carbon-carbon bond in the main chain skeleton such as acrylic polyol, polybutadiene diol, or hydrogenated polybutadiene polyol; low molecular weight polyhydric alcohol; or a mixed polyol thereof. Among these, polyether polyol is preferred.

[0018] The polyether polyol may be a compound having a polyether as a main chain and having two or more hydroxy groups. The polyether is a group having two or more ether bonds, and specific examples thereof include the structural unit -R a -OR b In the above structural unit, R a and R b are each independently a hydrocarbon group. The hydrocarbon group is not particularly limited. For example, it may be a linear alkylene group having 1 to 10 carbon atoms.

[0019] Examples of polyether polyols include polyoxyethylene diol (polyethylene glycol), polyoxypropylene diol (polypropylene glycol: PPG), polyoxypropylene triol, ethylene oxide / propylene oxide copolymer, polytetramethylene ether glycol (PTMEG), polytetraethylene glycol, and sorbitol-based polyols.

[0020] The polyether polyol is preferably polypropylene glycol or polyoxypropylene triol from the viewpoint of excellent compatibility with polyisocyanate.

[0021] The weight-average molecular weight of the polyether polyol is preferably 500 to 20,000, from the viewpoint that the viscosity of the urethane prepolymer obtained by the reaction with isocyanate can have appropriate fluidity at room temperature. In the present invention, the weight-average molecular weight is a polystyrene-equivalent value obtained by the GPC method (solvent: tetrahydrofuran (THF)).

[0022] From the viewpoint of superior adhesiveness and curability, the urethane prepolymer is preferably a urethane prepolymer obtained by reacting a polyether polyol with an aromatic polyisocyanate. The urethane prepolymer is more preferably a urethane prepolymer obtained by reacting at least one selected from the group consisting of polyoxypropylene diol and polyoxypropylene triol with diphenylmethane diisocyanate. Each urethane prepolymer can be used alone or in combination of two or more types.

[0023] The method for producing the urethane prepolymer is not particularly limited. For example, the urethane prepolymer may be produced by using a polyisocyanate so that 1.5 to 2.5 moles of isocyanate groups react with 1 mole of active hydrogen-containing groups (e.g., hydroxy groups) in the active hydrogen compound, and mixing and reacting them.

[0024] <Low molecular weight isocyanate compounds> The composition of the present invention contains a low molecular weight isocyanate compound. The low molecular weight isocyanate compound contains an aliphatic isocyanate component and an aromatic isocyanate component. The aliphatic isocyanate component contains an isocyanurate obtained by trimerizing an aliphatic isocyanate monomer. The aromatic isocyanate component contains a carbodiimide-modified isocyanate monomer. Note that the term "low molecular weight isocyanate compound" as used herein refers to an isocyanate compound that is not a urethane prepolymer having a structure obtained by reacting a polyol with a polyisocyanate, and that has multiple isocyanate groups. "Low molecular weight" refers to a compound having a molecular weight of 500 (g / mol) or less.

[0025] In the composition of the present invention, when the total amount of the urethane prepolymer contained in the composition is taken as 100 parts by weight, the amount of the low molecular weight isocyanate compound is preferably 1 to 15 parts by weight, more preferably 2 to 10 parts by weight, particularly preferably 3 to 9 parts by weight, and more preferably 4 to 8 parts by weight.

[0026] <Amount of aliphatic isocyanate component and aromatic isocyanate component> In the composition of the present invention, when 8.8% by weight of the total amount of urethane prepolymer contained in the composition is taken as 100 parts by weight, the amount of the aliphatic isocyanate blended is y parts by weight, the amount of the aromatic isocyanate blended is x parts by weight, and x and y are expressed by the following formula: Equation 1) -20 / 7x+596 / 7≦y Equation 2) y≦-2 / 9x+70 Equation 3) y≦-3x+143 Equation 4) x≦34 Equation 5) 24≦y Satisfy all of the above.

[0027] In the above formula 2), it is more preferable that y≦−2 / 9x+208 / 3. In the above formula 3), it is more preferable that y≦−3x+136. In the above formula 4), x≦32 is more preferred. In the above formula 5), ​​it is more preferable that 28≦y.

[0028] <Aliphatic isocyanate component> The aliphatic isocyanate component is described below. The aliphatic isocyanate component contained in the composition of the present invention includes an aliphatic isocyanate compound having at least one isocyanate group. By containing the aliphatic isocyanate component, the composition of the present invention is less likely to form an air gap between the adhesive and the adherend surface after curing, resulting in excellent adhesion.

[0029] The aliphatic hydrocarbon group contained in the aliphatic isocyanate compound may be linear, branched, or cyclic, and is preferably linear. The aliphatic hydrocarbon group may be saturated or unsaturated, and is preferably saturated. From the viewpoint of excellent adhesiveness, the number of isocyanate groups contained in the aliphatic isocyanate compound is preferably two or more, and more preferably two to three. Hereinafter, an aliphatic isocyanate having two or more isocyanate groups per molecule may be referred to as an aliphatic polyisocyanate compound.

[0030] Aliphatic polyisocyanate compounds include hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (H6XDI), dicyclohexylmethane diisocyanate (H 12 The aliphatic polyisocyanate compound may be a modified aliphatic polyisocyanate compound.

[0031] The modified aliphatic polyisocyanate is preferably a tri- or higher functional compound modified from an aliphatic diisocyanate, as this provides a better effect of the present invention and provides excellent primerless adhesion to coated plates.

[0032] The tri- or higher functional compound obtained by modifying an aliphatic diisocyanate is preferably at least one aliphatic isocyanate modified product a selected from the group consisting of, for example, a reaction product of a tri- or higher functional polyol with an aliphatic diisocyanate, an allophanate of an aliphatic diisocyanate, an isocyanurate (nurate) of an aliphatic diisocyanate, and a biuret of an aliphatic diisocyanate.

[0033] The aliphatic diisocyanate used in the aliphatic isocyanate modified product a may be the same as the above-mentioned aliphatic diisocyanate, but from the viewpoints of storage stability and adhesiveness, it is preferably a linear aliphatic diisocyanate compound, and HDI is more preferred.

[0034] The aliphatic isocyanate modified product a is preferably a trifunctional compound A obtained by modifying hexamethylene diisocyanate (HDI).

[0035] Examples of the trifunctional compound A modified with hexamethylene diisocyanate include reaction products of hexamethylene diisocyanate with trifunctional polyols such as trimethylolpropane (TMP) and glycerin; allophanate forms of hexamethylene diisocyanate, isocyanurate forms (nurate forms) of hexamethylene diisocyanate, and biuret forms of hexamethylene diisocyanate.

[0036] Examples of the reaction product of a trifunctional polyol and hexamethylene diisocyanate include a reaction product of TMP and HDI (e.g., a compound represented by the following formula (5)), and a reaction product of glycerin and HDI (e.g., a compound represented by the following formula (6)).

[0037] [ka]

[0038] [ka]

[0039] In the allophanate of hexamethylene diisocyanate, all of the isocyanates constituting the allophanate may be derived from hexamethylene diisocyanate, or a portion of the isocyanates may be derived from an isocyanate compound other than hexamethylene diisocyanate.

[0040] An example of a biuret of hexamethylene diisocyanate is a compound represented by the following formula (7). [ka]

[0041] The isocyanurate (nurate) of hexamethylene diisocyanate may be a compound represented by the following formula (8). [ka] The aliphatic isocyanate component preferably contains an isocyanurate of hexamethylene diisocyanate as a main component.

[0042] The aliphatic isocyanate component may be present in an amount that satisfies the above formulas 1) to 5), and for example, when the total amount of the urethane prepolymer is 100 parts by weight, the amount is preferably 1.0 to 10.0 parts by weight, more preferably 1.5 to 8.0 parts by weight, even more preferably 2.0 to 6.4 parts by weight, particularly preferably 2.2 to 6.2 parts by weight, and most preferably 2.4 to 6.0 parts by weight.

[0043] <Aromatic isocyanate component> The aromatic isocyanate component will be described below. The aromatic isocyanate component contained in the composition of the present invention includes an aromatic isocyanate compound having at least one isocyanate group and at least one aromatic ring in one molecule. From the viewpoint of excellent adhesiveness, the number of isocyanate groups in one molecule of the aromatic isocyanate compound is preferably 2 or more, more preferably 2 to 3. An aromatic isocyanate compound having two or more isocyanate groups in one molecule may be referred to as an aromatic polyisocyanate compound hereinafter. The number of aromatic rings in one molecule of the aromatic isocyanate compound is preferably 1 to 7, more preferably 2 to 6, particularly preferably 3 to 5, and most preferably 4.

[0044] Examples of aromatic polyisocyanate compounds include toluene diisocyanate (TDI), diphenylmethane diisocyanate (unsubstituted MDI, also known as pure MDI or monomeric MDI), 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate, polymeric MDI (a compound obtained by increasing the molecular weight of diphenylmethane diisocyanate (pure MDI)), and carbodiimide-modified MDI. The aromatic polyisocyanate component may contain one or more of these compounds. The aromatic isocyanate component preferably contains carbodiimide-modified MDI as the main component.

[0045] The aromatic isocyanate component may be present in an amount that satisfies the above formulas 1) to 5). For example, when the total amount of the urethane prepolymer is taken as 100 parts by weight, the amount is preferably 0.2 to 5.0 parts by weight, more preferably 0.45 to 3.1 parts by weight, particularly preferably 0.45 to 3.0 parts by weight, and most preferably 0.50 to 2.9 parts by weight.

[0046] <Filler> The composition of the present invention preferably contains a filler. The filler preferably contains an organic filler mainly composed of an organic compound and an inorganic filler mainly composed of an inorganic compound. The organic filler preferably contains carbon black as a main component. The inorganic filler preferably contains calcium carbonate as a main component.

[0047] <Carbon black> The composition of the present invention may contain carbon black as a filler. The carbon black preferably consists of multiple types of carbon black. The composition of the present invention may contain a first carbon black and a second carbon black as fillers.

[0048] (First carbon black) In the present invention, the dibutyl phthalate oil absorption (DBP oil absorption) of the first carbon black is 23 to 40 cm 3 / 100g may also be used. The DBP oil absorption of the first carbon black is 23 to 33 cm 3 / 100g is preferable, 27-30cm 3 / 100g is more preferred. The DBP oil absorption of the first carbon black is 28 to 40 cm 3 / 100g is preferable, 28-32cm 3 / 100g is more preferred. In the present invention, the dibutyl phthalate oil absorption of carbon black was measured in accordance with JIS K 6217-4:2008 "Carbon black for rubber - Fundamental properties - Part 4: Determination of oil absorption."

[0049] The first carbon black may be, for example, FT (Fine Thermal) grade. Examples of commercially available carbon black that can be used as the first carbon black include Nitelon #20 (manufactured by Shin-Nichika Carbon Co., Ltd., DBP oil absorption 29 cm 3 / 100g), Asahi Thermal (manufactured by Asahi Carbon Co., Ltd., DBP oil absorption capacity 28cm 3 / 100g). The first carbon black may be used alone or in combination of two or more kinds.

[0050] (Second carbon black) In the present invention, the dibutyl phthalate oil absorption of the second carbon black is 85 to 120 cm 3 / 100g may also be used. The DBP oil absorption of the second carbon black is preferably 95 to 120 cm in order to provide a superior effect of the present invention and excellent sagging resistance (the composition hardly sags or sags only slightly). 3 / 100g is preferable, 98-115cm 3 / 100g is more preferred. The DBP oil absorption of the second carbon black is preferably 85 to 115 cm3 in order to obtain a more excellent effect of the present invention and to have a superior shape retention. 3 / 100g is preferable, and 90 to 115cm3 / 100g is more preferable.

[0051] Examples of the second carbon black include HAF (High Abrasion Furnace) grade and ISAF (Intermediate Super Abrasion Furnace) grade. Commercially available carbon blacks that can be used as the second carbon black include, for example, Nitelon #200 (DBP oil absorption of 101 cm 3 / 100g), Niteron #300 (DBP oil absorption 115cm 3 / 100g) (both manufactured by Shin-Nichika Carbon Co., Ltd.). The second carbon black may be used alone or in combination of two or more kinds.

[0052] In the present invention, the content 1 of the first carbon black may be 25 parts by mass or more relative to 100 parts by mass of the urethane prepolymer, and is preferably 140 parts by mass or less relative to 100 parts by mass of the urethane prepolymer. The content 1 is preferably 45 parts by mass or more, more preferably 60 to 130 parts by mass, and even more preferably 75 to 100 parts by mass, per 100 parts by mass of the urethane prepolymer, in that the effects of the present invention are more excellent. In this case, the content 1 is sometimes referred to as the content 1-1. The content of 1 is preferably 25 to 95 parts by mass, more preferably 35 to 65 parts by mass, per 100 parts by mass of the urethane prepolymer, in that the effects of the present invention are more excellent and the balance between the shape retention and fluidity of the blended composition is excellent. In this case, content 1 is sometimes referred to as content 1-2.

[0053] The content 2 of the second carbon black is 9 parts by mass or more per 100 parts by mass of the urethane prepolymer. The content 2 is preferably 45 parts by mass or less per 100 parts by mass of the urethane prepolymer. The content 2 is preferably 10 to 30 parts by mass, more preferably 15 to 25 parts by mass, per 100 parts by mass of the urethane prepolymer, in order to achieve better effects of the present invention and excellent sagging resistance. In this case, the content 1 may be referred to as the content 2-1. The content 2 is preferably 15 to 45 parts by mass, more preferably 20 to 40 parts by mass, per 100 parts by mass of the urethane prepolymer, in that the effects of the present invention are more excellent and the balance between fluidity and shape retention is excellent. In this case, the content 1 is sometimes referred to as the content 2-2.

[0054] <Calcium carbonate> The composition of the present invention may contain calcium carbonate as a filler. The calcium carbonate contained in the composition of the present invention may be, for example, heavy calcium carbonate, precipitated calcium carbonate (light calcium carbonate), or colloidal calcium carbonate. The 50% cumulative particle size of calcium carbonate is preferably 1 to 10 μm. In the present invention, the 50% cumulative particle size of calcium carbonate was measured in accordance with JIS M 8511. Each calcium carbonate may be used alone or in combination of two or more types.

[0055] In the present invention, the content of calcium carbonate is 5 to 30 parts by mass relative to 100 parts by mass of the urethane prepolymer, and from the viewpoint of achieving better effects of the present invention and excellent deep curing properties, the content is preferably 6 to 20 parts by mass, and more preferably 8 to 20 parts by mass, relative to 100 parts by mass of the urethane prepolymer.

[0056] In the present invention, the content of calcium carbonate is 5 to 50 parts by mass relative to 100 parts by mass of the total of Content 1 (content of the first carbon black) and Content 2 (content of the second carbon black). In terms of achieving better effects of the present invention and excellent deep section curing, the content is preferably 10 to 30 parts by mass, and more preferably 12 to 18 parts by mass, relative to 100 parts by mass of the total of Content 1 and Content 2.

[0057] <Catalyst> The composition of the present invention preferably contains a catalyst capable of promoting the reaction of isocyanate groups with water, and more preferably contains a metal catalyst and an amine catalyst.

[0058] <Metal catalyst> The metal catalyst contained in the composition of the present invention is not particularly limited as long as it is a compound that can promote the reaction of isocyanate groups. For example, an organic metal catalyst and a metal catalyst consisting only of a metal without an organic group (also called an inorganic metal catalyst) can be mentioned. Examples of the metal contained in the metal catalyst include tin, bismuth, and titanium.

[0059] The organic group contained in the organometallic catalyst is not particularly limited. Examples of the organometallic catalyst include metal carboxylates, alkoxides, and complexes. The organometallic catalyst may contain, for example, at least one selected from the group consisting of a carboxylic acid, an alkoxy group, and a ligand. The carboxylic acid, the alkoxy group, and the ligand are not particularly limited. The metal catalyst preferably contains an organotin catalyst.

[0060] Examples of organotin catalysts include tin carboxylates such as dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin maleate, stannous octate, dibutyltin diacetylacetonate, and dioctyltin maleate; and reaction products of 1,3-diacetoxy-1,1,3,3-tetrabutyl-distannoxane and ethyl silicate in a molar ratio of 1:0.8 to 1:1.2.

[0061] Examples of organic titanium catalysts include tetrapropyl titanate, tetrabutyl titanate, tetraoctyl titanate, and titanium diisopropoxybis(ethylacetoacetate).

[0062] The metal catalyst is not limited in terms of its production, etc. Examples include conventionally known metal catalysts. The metal catalysts may be used alone or in combination of two or more.

[0063] The content of the metal catalyst is preferably 0.0003 to 0.04 parts by mass, more preferably 0.0004 to 0.03 parts by mass, and even more preferably 0.005 to 0.02 parts by mass, per 100 parts by mass of the urethane prepolymer, in order to achieve superior effects of the present invention and excellent primerless adhesion to painted plates.

[0064] <Amine catalyst> The amine catalyst contained in the composition of the present invention is a compound that has a nitrogen atom and promotes the reaction of an isocyanate group.

[0065] The amine catalyst preferably has a tertiary amino group (one nitrogen atom is single-bonded to three carbon atoms, or one nitrogen atom is single-bonded to one carbon atom and double-bonded to another carbon atom). Examples of amine catalysts having a tertiary amino group (tertiary amines) include trimethylamine, triethylamine, tripropylamine, tributylamine, triamylamine, trihexylamine, trioctylamine, trilaurylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethylamylamine, dimethylhexylamine, dimethylcyclohexylamine, dimethyloctylamine, dimethyllaurylamine, triallylamine, tetramethylethylenediamine, triethylenediamine, N -methylmorpholine, 4,4'-(oxydi-2,1-ethanediyl)bis-morpholine, N,N-dimethylbenzylamine, pyridine, picoline, dimethylaminomethylphenol, trisdimethylaminomethylphenol, 1,8-diazabicyclo[5.4.0]undecene-1,1,4-diazabicyclo[2.2.2]octane, triethanolamine, N,N'-dimethylpiperazine, tetramethylbutanediamine, bis(2,2-morpholinoethyl)ether, bis(dimethylaminoethyl)ether, and the like.

[0066] The amine catalyst preferably contains a dimorpholinodiethyl ether structure, since it has excellent effects of the present invention and excellent moisture curing properties. The dimorpholinodiethyl ether structure is a structure having dimorpholinodiethyl ether as a basic skeleton. In the dimorpholinodiethyl ether structure, the hydrogen atoms of the morpholine ring may be substituted with a substituent. The substituent is not particularly limited. For example, an alkyl group may be used. Examples of the alkyl group include a methyl group and an ethyl group.

[0067] An example of the amine catalyst containing a dimorpholinodiethyl ether structure is a compound represented by the following formula (1). [ka] In the above formula (1), R 1 , R 2are each independently an alkyl group, and m and n are each independently 0, 1, or 2. Specific examples of amine catalysts containing a dimorpholinodiethyl ether structure include dimorpholinodiethyl ether, di(methylmorpholino)diethyl ether, and di(dimethylmorpholino)diethyl ether. Each of these amine catalysts can be used alone or in combination of two or more.

[0068] The content of the amine catalyst is preferably 0.01 to 0.5 parts by mass, more preferably 0.02 to 0.4 parts by mass, and even more preferably 0.08 to 0.2 parts by mass, per 100 parts by mass of the urethane prepolymer, in terms of achieving better effects of the present invention and excellent moisture curing properties.

[0069] (additives) The composition of the present invention may contain additives, as needed, such as fillers other than carbon black and calcium carbonate, isocyanate compounds other than aliphatic isocyanates, catalysts other than metal catalysts and amine catalysts, plasticizers, anti-sagging agents, antioxidants, antioxidants, pigments (dyes), thixotropy-imparting agents, ultraviolet absorbers, flame retardants, surfactants (including leveling agents), dispersants, dehydrating agents, adhesion-imparting agents, and antistatic agents.

[0070] Among these, one of the preferred embodiments of the composition of the present invention further contains a plasticizer. Examples of the plasticizer include diisononyl phthalate (DINP), dioctyl adipate, isodecyl succinate, diethylene glycol dibenzoate, pentaerythritol ester, butyl oleate, methyl acetylricinoleate, tricresyl phosphate, trioctyl phosphate; propylene glycol adipate polyester, and butylene glycol adipate polyester. These plasticizers may be used alone or in combination of two or more. The content of the plasticizer is preferably 5 to 35% by mass based on the total amount of the composition.

[0071] The composition of the present invention can be obtained by any suitable production method. For example, the composition of the present invention can be produced by mixing and stirring the urethane prepolymer, carbon black, calcium carbonate, aliphatic isocyanate, metal catalyst, amine catalyst, and optional components that can be used as needed at room temperature or under heated conditions (40 to 60°C, for example, 40°C) using a roll, kneader, extruder, universal mixer, or the like.

[0072] The composition of the present invention is a one-component type and can be moisture-cured. The composition of the present invention can be cured, for example, by atmospheric moisture at temperatures between -20 and +50°C. In some cases, the composition of the present invention may be a two-component type.

[0073] The composition of the present invention can be used as an adhesive. The adherend to which the composition of the present invention can be applied may be, for example, metal (including coated plates), plastic, rubber, or glass. The composition of the present invention can be applied to the adherend without using a primer. The adherend to which no primer is used may be a coated plate. The coated plate may be a conventionally known one.

[0074] When the composition of the present invention is used in a direct glazing system for bonding a window glass to a body (painted panel), the composition of the present invention can be applied directly to the body without using a primer on the body. A primer may be used on the glass side. There are no particular restrictions on the primer used on the adherend. [Example]

[0075] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. <Production of Composition> Each component in the following table was used in the composition (parts by mass) shown in the table and mixed with a stirrer to produce a composition.

[0076] <Evaluation> The compositions produced as described above were evaluated as follows. The results are shown in Table 1. Table 2 shows whether the more preferable numerical ranges of formulas 1) to 5) were satisfied.

[0077] JPEG0007795031000007.jpg71135

[0078] JPEG0007795031000008.jpg54135

[0079] Details of each component shown in Tables 1 and 2 are as follows.

[0080] Urethane prepolymer 1: 500 g of polyoxypropylene diol (weight average molecular weight 2000), 750 g of polyoxypropylene triol (weight average molecular weight 5000), and 214 g of 4,4'-diisocyanate phenylmethane (molecular weight 250) were mixed (NCO / OH = 1.8 at this time), and 160 g of diisononyl phthalate was added. The mixture was stirred in a nitrogen stream at 80°C for 24 hours to react, synthesizing urethane prepolymer 1 containing 1.95% isocyanate groups. Carbon black F (first carbon black): Trade name Nitelon #20, manufactured by Shin-Nichika Carbon Co., Ltd., DBP oil absorption 29 cm 3 / 100g, FT grade Carbon black A (second carbon black): Trade name Nitelon #300, manufactured by Shin-Nichika Carbon Co., Ltd., DBP oil absorption 115 cm 3 / 100g, ISAF grade The oil absorption of carbon black is the dibutyl phthalate oil absorption (DBP oil absorption), and its unit is cm 3 / 100g. Calcium carbonate: Heavy calcium carbonate, 50% cumulative particle size 8.5 μm (Super S, Maruo Calcium Co., Ltd.) C-MDI: Carbodiimide-modified MDI represented by the following formula: Trade name: MILLIONATE MTL (Tosoh Corporation) HDI trimer: HDI isocyanurate represented by the above formula (8) (D170N, manufactured by Mitsui Takeda Urethane Co., Ltd.) Sn catalyst: dioctyl tin laurate (Neostan U-810, manufactured by Nitto Kasei Co., Ltd.) Amine catalyst (DMDEE): Dimorpholinodiethyl ether (San-Apro Co., Ltd.)

[0081] [ka]

[0082] Tensile modulus Each composition prepared as described above was cured for 336 hours under conditions of 20°C and 65% RH, and a dumbbell-shaped No. 3 sample was cut from the resulting cured product to prepare a 3 mm thick sample. Using the dumbbell-shaped samples prepared as described above, the tensile modulus (unit: MPa) was measured at 23°C and a pulling rate of 500 mm / min in accordance with JIS K 6251. The tensile modulus was calculated from two stresses: 10 N and 20 N. A tensile modulus of 8 to 14 MPa was evaluated as having high hardness, i.e., high rigidity, for the resulting cured product.

[0083] [Breaking elongation measurement] Using dumbbell-shaped samples obtained in the same manner, the elongation at break (%) was measured in accordance with JIS K6251-1993. Elongation at break of 200% or more was evaluated as good.

[0084] [Adhesion to painted board (P2P adhesion test)] Each composition prepared as described above was applied to a painted panel (electrodeposition-coated steel plate coated with a clear coat: KINO-1200TW manufactured by Kansai Paint Co., Ltd., and baked at 140°C for 30 minutes). Each painted panel coated with each composition was cured for one week at 5°C and 50% RH, then immersed in 50°C warm water for two weeks, and then subjected to a knife cut test. The results of the evaluation of the state of failure are shown in Table 1. CF indicates cohesive failure of the cured product, AF indicates interfacial failure between the coated plate and the cured product, and B indicates the presence of bubbles at the adhesive interface. CF was evaluated as good.

[0085] [Short-time cure water immersion adhesion test] The adhesive was applied to glass coated with glass primer and pressed to a thickness of 3 mm. After leaving it for 3 hours in an environment of 20°C and 60% humidity, it was immersed in warm water at 45°C and after 7 days, a knife cut test was carried out. The results of the evaluation of the state of failure are shown in Table 1. CF indicates cohesive failure of the cured material, AF indicates interfacial failure between the coated plate and the cured material, and B indicates the presence of bubbles at the adhesive interface. CF was evaluated as good.

[0086] The composition of the present invention, which satisfies all of the conditions of formulas 1) to 5), exhibited good adhesion in both the P2P adhesion test and the short-time cure water immersion adhesion test, and was also excellent in tensile modulus and elongation at break.

Claims

1. A one-component moisture-curable curable polyurethane resin composition containing a urethane prepolymer, a filler, a low-molecular-weight isocyanate compound, and a catalyst, the low molecular weight isocyanate compound contains an aliphatic isocyanate component and an aromatic isocyanate component, The aliphatic isocyanate component is mainly composed of a trimer of hexamethylene diisocyanate, the aromatic isocyanate component is composed mainly of a carbodiimide-modified diphenylmethane diisocyanate, When 8.8% by weight of the total amount of the urethane prepolymer is taken as 100 parts by weight, the blending amount of the aliphatic isocyanate component is y parts by weight, the blending amount of the aromatic isocyanate component is x parts by weight, and the x and y are expressed by the following formula: 1) -20 / 7x+596 / 7≦y 2) y≦-2 / 9x+70 3) y≦-3x+143 4) x≦34 5) 24≦y A curable polyurethane resin composition that satisfies the above requirements.

2. A curable polyurethane resin composition according to claim 1, wherein the above formula 3) satisfies y≦−3x+136.

3. A resin obtained by curing the curable polyurethane resin composition according to claim 1 or 2.

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