JP2008111032A - Urethane adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a urethane adhesive composition exhibiting excellent adhesiveness to various metals (including electrodeposition coating) and glass without using a primer. <P>SOLUTION: The urethane adhesive composition comprises a base material component containing a polyisocyanate compound (A), and a curing agent component containing a polyol compound (B) and an epoxysilane compound (C) having one or more of each of hydroxy groups, epoxy groups and alkoxysilyl groups, and totally four of the epoxy groups and the alkoxysilyl groups. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a urethane adhesive composition.

A polyisocyanate compound having two or more isocyanate groups in the molecule (for example, urethane prepolymer) forms a three-dimensional crosslinked structure by reaction with a curing agent such as an amine compound or a polyol compound, and has high strength and high elongation. It becomes a polyurethane cured product excellent in wear resistance, oil resistance and the like.
Conventionally, polyurethane resin compositions containing such a polyisocyanate compound as a main ingredient have been widely used as adhesives, joint materials, sealants and the like. In particular, polyurethane resin compositions used in automotive interior adhesives and architectural sealants are required to have excellent adhesion to various adherends such as glass, metal, plastic, coated steel sheet, mortar, and vinyl chloride. ing.

As such a polyurethane resin composition, for example, Patent Document 1 describes “a urethane-based adhesive composition characterized by containing an isocyanate alkoxysilane in a urethane-based adhesive composition”. Yes.
Patent Document 2 discloses that “a polyol (a) having a hydroxyl equivalent weight of 500 to 2000 consisting of a copolymer of tetrahydrofuran and ethylene oxide and other polyols (b), excess aromatic polyisocyanate (c) and A moisture-curing urethane adhesive or sealing agent comprising an isocyanate group-terminated urethane prepolymer comprising:
Furthermore, the present applicant also stated that “a main component containing a urethane prepolymer (A) and a compound (B) having at least one isocyanate group, isocyanurate group and hydrolyzable silicon-containing group, and a polyol compound ( A two-component curable polyurethane resin composition comprising a curing agent containing C) has been proposed (Patent Document 3).

JP-A-2-279784 JP 2000-230165 A JP 2006-1111811 A

However, the urethane-based adhesive compositions described in these patent documents are used for adhesion between a metal surface (including an electrodeposited surface) and a glass surface, on the premise that no primer is used. In some cases, a primer may be required depending on the type of metal or glass.
Therefore, an object of the present invention is to provide a urethane adhesive composition having excellent adhesion to various metals (including electrodeposition coating, the same applies hereinafter) and glass without using a primer. .

  As a result of intensive studies to solve the above problems, the present inventor has one or more of a hydroxyl group, an epoxy group, and an alkoxysilyl group, and a specific number having a total of four of the epoxy group and the alkoxysilyl group. By using a curing agent component containing an epoxysilane compound, it was found that a urethane adhesive composition having excellent adhesion to various metals and glasses can be provided without using a primer, and the present invention was completed. It was.

That is, the present invention provides the following (1) to (5).
(1) a base material component containing a polyisocyanate compound (A);
Curing agent component containing a polyol compound (B) and an epoxy silane compound (C) having at least one hydroxyl group, epoxy group and alkoxysilyl group, and having a total of four epoxy groups and alkoxysilyl groups. A urethane adhesive composition comprising:
(2) The above epoxy silane compound (C) has a substituent R on the nitrogen atom at the γ-position of the carbon atom to which the hydroxyl group is bonded, and the substituent R is an aryl group or an alicyclic hydrocarbon group ( 1. Urethane adhesive composition as described in 1).
(3) The urethane adhesive composition according to (1) or (2), wherein the epoxysilane compound (C) is obtained by a reaction between an aminosilane compound (c1) and a tetraglycidylamine compound (c2).
(4) The aminosilane compound (c1) is N-phenyl-γ-aminopropyltrimethoxysilane, and the tetraglycidylamine compound (c2) is 1,3-bis (N, N-glycidylaminomethyl) cyclohexane. N, N, N ′, N′-tetraglycidyl-m-xylylenediamine and at least selected from the group consisting of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane The urethane adhesive composition according to (3), which is one type.
(5) The urethane according to any one of (1) to (4), wherein the content of the epoxysilane compound (C) is more than 2% by mass and less than 20% by mass with respect to the total mass of the curing agent component. Adhesive composition.

  As shown below, according to the present invention, a urethane adhesive composition having excellent adhesion to various metals and glass can be provided without using a primer.

The urethane adhesive composition of the present invention (hereinafter also referred to as “the adhesive composition of the present invention”) includes a base component containing a polyisocyanate compound (A), a polyol compound (B), a hydroxyl group, and an epoxy group. And a curing agent component containing an epoxy silane compound (C) having at least one alkoxysilyl group and four epoxysilanes and a total of four alkoxysilyl groups, and a urethane adhesive composition comprising: is there.
Hereinafter, the polyisocyanate compound (A), the polyol compound (B) and the epoxysilane compound (C) will be described in detail.

<Polyisocyanate compound (A)>
The said polyisocyanate compound (A) is a component which reacts with the polyol compound (B) mentioned later at the time of use (at the time of construction) of the adhesive composition of the present invention to make a polyurethane.

The polyisocyanate compound (A) is not particularly limited as long as it is a compound having two or more isocyanate (NCO) groups in the molecule. Specific examples thereof include TDI (for example, 2,4-tolylene diisocyanate (2 , 4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI (for example, 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4′-diphenylmethane diisocyanate ( 2,4'-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), G Aromatic polyisocyanates such as phenylmethane triisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate methyl (NBDI); transcyclohexane-1,4 -Alicyclic polyisocyanates such as diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanatemethyl) cyclohexane (H ₆ XDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI), hydrogenated TDI (H ₆ TDI); Carbodiimide-modified polyisocyanates; isocyanurate-modified polyisocyanates of these isocyanate compounds; Isocyanate compound and a polyol compound and a urethane prepolymer obtained by reacting a; and the like, may be used those either alone, or in combination of two or more.
A monoisocyanate compound having only one NCO group in the molecule can also be used by mixing with a diisocyanate compound or the like.

Of these polyisocyanate compounds, urethane prepolymers are preferred from the viewpoints of cost and safety.
Such a urethane prepolymer is obtained by reacting a polyol compound with an excess of a polyisocyanate compound. Specific examples thereof include various polyisocyanate compounds exemplified above and various polyol compounds described later. The thing by a combination is mentioned.
Among these, from the viewpoint of availability, at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polypropylene triol and polytetraethylene glycol, and consisting of tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate and hexamethylene diisocyanate. A urethane prepolymer obtained from at least one selected from the group is preferred. In particular, an MDI urethane prepolymer obtained by reacting MDI and a polyol compound is more preferable.

  In the present invention, the method for producing the urethane prepolymer is not particularly limited, and specific examples thereof include a reaction temperature of 30 to 120 ° C., preferably about 50 to 100 ° C., and a polyol compound and a polyisocyanate compound under normal pressure. And a method of obtaining a urethane prepolymer. Further, a urethanization catalyst such as an organic tin compound or an organic bismuth compound can be used.

  Moreover, in this invention, in manufacture of the said urethane prepolymer, the equivalent ratio (NCO / OH) of the NCO group of the polyisocyanate compound with respect to the hydroxyl (OH) group of a polyol compound is 1.2-5.0. And is more preferably 1.5 to 3.0. When NCO / OH is within this range, there is no foaming due to the remaining polyisocyanate compound and no increase in the viscosity of the urethane prepolymer due to molecular chain extension, and the physical properties after curing of the adhesive composition of the present invention are improved. .

  In the present invention, as described above, the polyisocyanate compound (A) and the polyol compound (B) described below react to form a polyurethane upon use, so that the adhesive composition of the present invention is sticky during construction. The polyisocyanate compound (A) is contained so as to be an excessive amount of NCO groups with respect to the OH groups of the polyol compound (B) described later, from the viewpoint of preventing the adhesion and improving the adhesion to metals and glass. It is preferable.

Moreover, in this invention, it is preferable that content of the said polyisocyanate compound (A) is 20 mass% or more with respect to the whole mass of the said base material component, and 100 mass% may be sufficient.
When content of the said polyisocyanate compound (A) is less than 100 mass%, the said base material component is a reinforcing material (for example, carbon black etc.), an extender (for example, carbon black etc.) other than the said polyisocyanate compound (A). , Calcium carbonate, clay, etc.), plasticizers, silane coupling agents, catalysts, solvents, adhesion promoters, and the like.

<Polyol compound (B)>
As long as the polyol compound (B) is a compound having two or more hydroxyl groups, its molecular weight and skeleton are not particularly limited, and specific examples thereof include low-molecular polyhydric alcohols, polycarbonate polyols, polyether polyols, Examples thereof include polyester polyols, other polyols, and mixed polyols thereof.

  Here, specific examples of the low-molecular polyhydric alcohols include ethylene glycol (EG), diethylene glycol, propylene glycol (PG), dipropylene glycol, and (1,3- or 1,4-) butanediol. , Pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane (TMP), 1,2,5-hexanetriol, And low molecular polyols such as pentaerythritol; sugars such as sorbitol; and the like.

Next, as the polycarbonate polyol, for example, one obtained by a transesterification reaction between a polyol compound and a dialkyl carbonate can be used.
Specific examples of the polyol compound include 1,6-hexanediol, 1,4-butanediol, and 1,5-pentanediol among the various low-molecular polyhydric alcohols exemplified above. It is mentioned in.
Moreover, as this dialkyl carbonate, the dialkyl carbonate represented by following formula (1) can be used, for example.

（式中、Ｒ¹およびＲ²は、それぞれ独立に、炭素数１２以下のアルキル基である。）

(In the formula, R ¹ and R ² are each independently an alkyl group having 12 or less carbon atoms.)

  Specific examples of the dialkyl carbonate represented by the above formula (1) include dimethyl carbonate and diethyl carbonate.

  Specific examples of the catalyst suitable for the transesterification reaction between the polyol compound and the dialkyl carbonate include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide and potassium hydroxide; Metal alcoholates such as rate, potassium methylate, titanium tetraisopropylate, zirconium tetraisopropylate; and the like. Of these, titanium tetraisopropylate and zirconium tetraisopropylate are preferred.

Next, as the polyether polyol and polyester polyol, those derived from the above low-molecular polyhydric alcohols are usually used. In the present invention, the following aromatic diols, amines and alkanolamines are further used. Those derived from the above can also be suitably used.
Here, specific examples of the aromatic diols include resorcin (m-dihydroxybenzene), xylylene glycol, 1,4-benzenedimethanol, styrene glycol, 4,4′-dihydroxyethylphenol; Bisphenol A structure (4,4'-dihydroxyphenylpropane), bisphenol F structure (4,4'-dihydroxyphenylmethane), brominated bisphenol A structure, hydrogenated bisphenol A structure, bisphenol S structure, bisphenol AF Those having a bisphenol skeleton having a structure;

  Specific examples of amines include ethylenediamine and hexamethylenediamine. Specific examples of alkanolamines include ethanolamine and propanolamine.

As the polyether polyol, for example, at least one selected from the compounds exemplified as the low-molecular polyhydric alcohols, the aromatic diols, the amines, and the alkanolamines, an alkylene such as ethylene oxide and propylene oxide can be used. Polyols obtained by adding at least one selected from oxides and styrene oxides; polyols obtained by polymerizing monomers such as butylene oxide (tetramethylene oxide) and tetrahydrofuran using a cationic initiator; and the like .
Specific examples of such polyether polyols include polyethylene glycol, polypropylene glycol (PPG), polypropylene triol, ethylene oxide / propylene oxide copolymer, polytetramethylene ether glycol (PTMEG), polytetraethylene glycol, sorbitol-based polyol. Etc.
Specific examples of polyether polyols having a bisphenol skeleton include polyether polyols obtained by adding ethylene oxide and / or propylene oxide to bisphenol A (4,4′-dihydroxyphenylpropane).

Similarly, as the polyester polyol, for example, a condensate (condensed polyester polyol) of any one of the low molecular polyhydric alcohols, the aromatic diols, the amines and the alkanolamines with a polybasic carboxylic acid. ); Lactone polyols; and the like.
Specific examples of the polybasic carboxylic acid that forms the condensed polyester polyol include glutaric acid, adipic acid, azelaic acid, fumaric acid, maleic acid, pimelic acid, suberic acid, sebacic acid, phthalic acid, Examples include hydroxycarboxylic acids such as terephthalic acid, isophthalic acid, dimer acid, pyromellitic acid, other low-molecular carboxylic acids, oligomeric acids, castor oil, and a reaction product of castor oil and ethylene glycol (or propylene glycol). .
Further, as the lactone-based polyol, specifically, for example, a lactone such as ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone was ring-opened and polymerized with an appropriate polymerization initiator. And those having hydroxyl groups at both ends.
Examples of the polyester polyol having a bisphenol skeleton include condensed polyester polyols obtained by using a diol having a bisphenol skeleton instead of the low molecular polyhydric alcohols or together with the low molecular polyhydric alcohols. Specific examples include polyester polyols obtained from bisphenol A and castor oil, polyester polyols obtained from bisphenol A, castor oil, ethylene glycol, and propylene glycol.

  Specific examples of other polyols include acrylic polyols; polybutadiene polyols; polymer polyols having a carbon-carbon bond in the main chain skeleton, such as hydrogenated polybutadiene polyols.

  In the present invention, the various polyol compounds exemplified above may be used alone or in combination of two or more.

Of these polyol compounds, a compound having a higher reactivity with the polyisocyanate compound (A) than the epoxysilane compound (C) described later is preferable.
Specifically, when a urethane prepolymer is used as the polyisocyanate compound (A), it is a polybutadiene polyol, but the reactivity with the urethane prepolymer is sufficiently high, and a good pot life can be secured, Furthermore, the adhesive composition of the present invention containing these is preferable because of its excellent water-resistant adhesion.

  In the present invention, the number average molecular weight of the polyol compound (B) is not particularly limited. However, when a urethane prepolymer is used as the polyisocyanate compound (A), the reactivity with the urethane prepolymer and the present invention obtained are obtained. From the viewpoint of foamability and elasticity of the adhesive composition, it is preferably 300 to 10,000. In particular, when used as a sealing material in the adhesive composition of the present invention, it is preferably about 1000 to 7000.

  Moreover, in this invention, it is preferable that content of the said polyol compound (B) is less than 80 mass% with respect to the total mass of the said hardening | curing agent component. When the content is in this range, the adhesive property of the obtained adhesive composition of the present invention to glass is further improved, and the adhesion rate is further improved.

<Epoxysilane compound (C)>
The epoxysilane compound (C) is a compound having one or more hydroxyl groups, epoxy groups, and alkoxysilyl groups, and a total of four epoxy groups and alkoxysilyl groups.
Here, specifically as an alkoxysilyl group, the substituent represented by following General formula (2) is mentioned suitably, for example. In the following general formula (2), the bond on the left side of the silicon atom does not represent a methyl group.

In the general formula (2), R ³ and R ⁴ are each independently an alkyl group having 1 to 8 carbon atoms which may be branched, and n is an integer of 0 to 2. Moreover, several R < ³ > or R < ⁴ > may be same or different, respectively.

Specific examples of the optionally branched alkyl group having 1 to 8 carbon atoms of R ³ and R ⁴ include, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, and the like. The group may contain a double bond or a triple bond. Of these, a methyl group and an ethyl group are preferable.

Specific examples of the alkoxysilyl group represented by the general formula (2) include, for example, a trimethoxysilyl group (n = 0, R ⁴ = methyl group), a methyldimethoxysilyl group (n = 1, R ^3). = R ⁴ = methyl group), triethoxysilyl group (n = 0, R ⁴ = ethyl group), methyldiethoxysilyl group (n = 1, R ³ = methyl group, R ⁴ = ethyl group) and the like are preferred. Can be mentioned.

By containing such an epoxy silane compound (C) as a curing agent component, the adhesive composition of the present invention has excellent adhesion to various metals and glasses without using a primer. This is presumably because the epoxy group of the epoxysilane compound (C) contributes to the adhesion to the metal and the alkoxysilyl group contributes to the adhesion to the glass.
Therefore, in the case of bonding a hardly-adhesive metal (for example, SUS (stainless steel)) and glass, the epoxysilane compound (C) preferably has 2 to 3 epoxy groups. On the other hand, when bonding a metal and difficult-to-adhere glass (for example, float glass having a tin surface), the epoxysilane compound (C) preferably has 2 to 3 alkoxysilyl groups. .
In the above-mentioned patent documents, various silane coupling agents are used, but none of them corresponds to the epoxy silane compound (C). For example, as shown in Comparative Example 1 of the present specification. In addition, when 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) is used, the result is poor adhesion to metal and glass.

In the present invention, the epoxysilane compound (C) has a substituent R on the nitrogen atom at the γ-position of the carbon atom to which the hydroxyl group is bonded, and the substituent R is an aryl group (for example, a phenyl group) or It is preferably an alicyclic hydrocarbon group (for example, a cyclohexyl group).
By having such a substituent R, the adhesiveness of the adhesive composition of the present invention to metal and glass is further improved, and the storage stability of the curing agent component is also improved. This is considered to be because of the steric hindrance of these substituents R, the reactivity of the hydroxyl group to the isocyanate group of the polyisocyanate compound (A) is reduced, and the condensation reaction with the alkoxysilyl group can also be suppressed. .

Moreover, in this invention, it is preferable that the said epoxysilane compound (C) is a thing obtained by reaction of an aminosilane compound and a tetraglycidylamine compound.
Specifically, N-phenyl-γ-aminopropyltrimethoxysilane, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylyl Preferable examples include those obtained by reaction with range amine and at least one selected from the group consisting of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane.

  Furthermore, in this invention, it is preferable that content of the said epoxy silane compound (C) is more than 2 mass% and less than 20 mass% with respect to the total mass of the said hardening | curing agent component. When the content is within this range, the adhesion of the obtained adhesive composition of the present invention to metal and glass is further improved.

  In the present invention, the total content of the polyol compound (B) and the epoxysilane compound (C) includes the NCO group of the polyisocyanate compound (A), the polyol compound (B), and the epoxysilane compound ( It is preferable that the ratio of C) to OH groups (NCO / OH) is 10 to 0.9. When the content is within this range, a moderate pot life can be obtained without causing poor curing. In view of these characteristics, the molar ratio is more preferably 2.5 to 1.5.

  In the present invention, the content ratio of the polyol compound (B) and the silane compound (C) is such that the ratio of the OH group of the polyol compound (B) to the OH group of the silane compound (C) is 10. : 0.5 to 10: 5 is preferable. When the content ratio is within this range, a moderate pot life can be obtained without causing poor curing. From the point which is excellent by these characteristics, it is more preferable that it will be 10: 0.8-10: 1.2.

The adhesive composition of the present invention preferably further contains a metal catalyst such as a tin catalyst or a titanium catalyst.
Specific examples of the tin catalyst include tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate and tin naphthenate; a reaction product of dibutyltin oxide and phthalate; dibutyltin diacetylacetate Naruto.
Specific examples of the titanium catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate.

  The adhesive composition of the present invention can contain various additives as required in addition to the above-mentioned various components within a range not impairing the object of the present invention. Examples of the additive include a filler, an antioxidant, an antioxidant, an antistatic agent, a flame retardant, a dispersant, and a thixotropic agent.

  Examples of the filler include wax stone clay, kaolin clay, calcined clay; fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, oxidized Magnesium; calcium carbonate, magnesium carbonate, zinc carbonate; organic or inorganic fillers such as carbon black; these fatty acids, resin acids, fatty acid ester treated products, and fatty acid ester urethane compound treated products.

Examples of the antiaging agent include hindered phenol compounds and hindered amine compounds.
Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).
Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.
Examples of the thixotropic agent include hydrogenated castor oil, silica, and talc.
The above additives can be used in combination as appropriate.

  In the present invention, the above-described various additives (including a metal catalyst, the same applies hereinafter) can be contained as a main component and / or a curing agent component, if necessary.

  The method for producing the adhesive composition of the present invention is not particularly limited. For example, the base component containing the polyisocyanate compound (A), the polyol compound (B), the epoxysilane compound (C), and the above Produced at the time of use by mixing with hardener components containing various additives, mixing thoroughly at room temperature using a roll, kneader, extruder, universal agitator, etc., and uniformly dispersing (kneading) Can do.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to this.

<Synthesis of Polyisocyanate Compound A1>
First, 500 g of polypropylene diol (number average molecular weight 2000), 750 g of polypropylene triol (number average molecular weight 5000), and 1460 g of dioctyl phthalate as a plasticizer were mixed, and the resulting mixture was dehydrated at 110 ° C. for 16 hours under reduced pressure. did.
Thereafter, 214 g of 4,4′-diphenylmethane diisocyanate was added to the mixture so that the NCO / OH molar ratio was 1.80, and the mixture was reacted at 80 ° C. for 24 hours in a nitrogen stream. 1.11 mass% urethane prepolymer (number average molecular weight 6000) was obtained as polyisocyanate compound A1.

(Comparative example 1, Examples 1-3)
The obtained polyisocyanate compound A1 and each composition component shown in the following Table 1 were mixed so as to have a mass part shown in the following Table 1, thereby preparing a urethane adhesive composition.
About each prepared adhesive composition, adhesiveness was evaluated as follows. The results are shown in Table 1 below.

<Adhesiveness (I)>
SUS / Electrodeposited coated plate (size: 25mm x 120mm x 1mm) The surface of each adhesive composition is cleaned without using a primer so that the thickness of the adhesive layer after crimping is 3mm. An object was applied and pressure-bonded to prepare a test piece.

(I) Adhesiveness after 20 ° C. × 7 days (adhesiveness after initial curing)
The prepared test piece was left and cured under conditions of 20 ° C. and 60% RH for 7 days, and then subjected to a hand-peeling test with a knife cut specified in JASO (Automobile Standard) M338-89, and the state of destruction was visually observed. Observed at.
Specifically, a knife is put at 20 to 30 mm at the interface between the glass and the adhesive layer, and a part of the adhesive layer (part pulled by hand) is peeled off from the glass, and then the test piece is fixed, The adhesive layer was pulled by hand in a direction of 90 degrees or more. The pulling by hand was performed with a knife cut of about 60 degrees with a sharp knife or the like at an interval of 5 to 10 mm.
(Ii) Adhesiveness after 14 days at 90 ° C. (Adhesiveness after heat aging)
After the initial curing, it is further placed in an oven at 90 ° C. for 14 days, after which it is cooled to 20 ° C. at room temperature for one day or more, and then subjected to a hand-peeling test similar to the above to visually check the state of destruction. Observed.
In Table 1, “CF100” indicates the entire area of the adhesive surface between the electrodeposition coating surface and the glass plate (excluding the part where the adhesive layer is peeled off by hand pulling). (100%) indicates cohesive failure, “AF20” indicates interface failure at 20% of the bonded surface, “AF50” indicates interface failure at 50% of the bonded surface, “AF100” Indicates that interfacial breakage occurred in the entire area (100%) of the bonded surface.

<Adhesiveness (II)>
SUS (size: 25 mm × 120 mm × 1 mm) The surface was washed with isopropyl alcohol, and each adhesive composition was applied thereon without using a primer so that the thickness of the adhesive layer after pressure bonding was 3 mm. A test piece was prepared by pressure bonding.
About the produced test piece, adhesiveness was evaluated by the method similar to adhesiveness (I) mentioned above.

<Adhesiveness (III)>
Float glass (size: 25 mm x 100 mm x 5 mm) non-tin surface (surface that is easy to adhere) is washed with isopropyl alcohol, and without using a primer so that the thickness of the adhesive layer after crimping is 3 mm. Each adhesive composition was applied to and pressure-bonded to prepare a test piece.
About the produced test piece, adhesiveness was evaluated by the method similar to adhesiveness (I) mentioned above.

<Adhesiveness (IV)>
Flush glass (size: 25 mm x 100 mm x 5 mm) tin surface (surface that is difficult to adhere) is washed with isopropyl alcohol, and without using a primer so that the thickness of the adhesive layer after crimping is 3 mm Each adhesive composition was applied and pressed to prepare a test piece.
About the produced test piece, adhesiveness was evaluated by the method similar to adhesiveness (I) mentioned above.

Each composition component in Table 1 other than polyisocyanate compound A1 is as shown below.
・ Calcium carbonate: Fatty acid-treated precipitated calcium carbonate (Calfine 200, manufactured by Maruo Calcium Co., Ltd.)
・ Carbon black: A-2899 (Asahi Carbon Co., Ltd.)
Plasticizer: isononyl adipate (DINA, manufactured by Mitsubishi Gas Chemical Company)
Polyol compound B1: Polybutadiene diol (Poly bd R45, number average molecular weight 2000, manufactured by Idemitsu Kosan Co., Ltd.)

  Epoxysilane compound C1: 1 mol of N-phenyl-γ-aminopropyltrimethoxysilane (KBM573, manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 mol of N, N, N ′, N′-tetraglycidyl-m-xylenediamine (TETRAD-X, manufactured by Mitsubishi Gas Chemical Company) and a compound represented by the following formula (3) obtained by reacting at 60 ° C. for 24 hours

  Epoxysilane compound C2: 2 mol of N-phenyl-γ-aminopropyltrimethoxysilane (KBM573, manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 mol of 1,3-bis (N, N-glycidylaminomethyl) cyclohexane (TETRAD) -C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and a compound represented by the following formula (4) obtained by reacting at 60 ° C. for 24 hours.

  Epoxysilane compound C3: 3 mol of N-phenyl-γ-aminopropyltrimethoxysilane (KBM573, manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 mol of N, N, N ′, N′-tetraglycidyl-4,4 ′ -Compound represented by the following formula (5) obtained by reacting diaminodiphenylmethane (YH-434, manufactured by Tohto Kasei Co., Ltd.) at 60 ° C for 24 hours.

  ・ Epoxysilane 1: 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.)

From the results shown in Table 1, it was found that the adhesive compositions prepared in Examples 1 to 3 had excellent adhesion to various metals and glasses without using a primer. In particular, in Examples 1 to 3, it can be seen that it has good adhesion even to a hardly-adhesive metal (electrodeposition coating). Was also found to have good adhesion.
On the other hand, since the adhesive composition prepared in Comparative Example 1 does not contain the epoxysilane compound (C), the adhesiveness after heat aging is inferior in any of the adhesiveness (I) to (IV), In the evaluation of adhesiveness (II), it was found that the initial adhesiveness was also poor.

Claims (5)

A base material component containing a polyisocyanate compound (A);
Curing agent component containing a polyol compound (B) and an epoxy silane compound (C) having at least one hydroxyl group, an epoxy group and an alkoxysilyl group, and a total of four of the epoxy group and the alkoxysilyl group. A urethane adhesive composition comprising:   2. The epoxy silane compound (C) has a substituent R on a nitrogen atom at the γ-position of a carbon atom to which a hydroxyl group is bonded, and the substituent R is an aryl group or an alicyclic hydrocarbon group. Urethane adhesive composition.   The urethane adhesive composition according to claim 1 or 2, wherein the epoxysilane compound (C) is obtained by a reaction between an aminosilane compound (c1) and a tetraglycidylamine compound (c2).   The aminosilane compound (c1) is N-phenyl-γ-aminopropyltrimethoxysilane, and the tetraglycidylamine compound (c2) is 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, At least one selected from the group consisting of N, N ′, N′-tetraglycidyl-m-xylylenediamine and N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane The urethane adhesive composition according to claim 3.   The urethane adhesive composition according to any one of claims 1 to 4, wherein the content of the epoxysilane compound (C) is more than 2 mass% and less than 20 mass% with respect to the total mass of the curing agent component.