JP2014077094A - Urethane adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane adhesive composition having stably excellent adhesiveness to an adherend without the application of a primer composition.SOLUTION: A urethane adhesive composition includes a base compound containing a urethane prepolymer and an isocyanate silane compound, and a curing agent containing polybutadiene diol. The urethane adhesive composition can have stably excellent adhesiveness to an adherend without the application of a primer composition.

Description

  The present invention relates to a urethane adhesive composition.

  Urethane resin compositions utilizing moisture curing are widely used in various fields such as the automotive field and the architectural field. Generally, a window sealant is used for bonding an automobile body and a window glass. However, in many cases, sufficient adhesion cannot be obtained by bonding using only a window sealant. Therefore, if sufficient adhesiveness cannot be obtained with the sealant or adhesive alone, after applying the primer composition to the adhesive surface in advance, apply adhesive etc. on it to ensure sufficient adhesiveness. (For example, refer to Patent Documents 1 to 6).

JP 2007-51287 A JP 2006-335921 A JP 2001-123092 A JP 2000-63768 A JP 2000-327956 A JP 2009-280682 A

  However, since the primer composition uses a large amount of solvent so that it can be uniformly applied, there is an environmental problem, and only a line for applying the primer composition requires a separate process such as ventilation. It is. For this reason, even if the body of the automobile and the window glass are directly bonded without using a primer composition in order to simplify the bonding work between the body of the automobile and the window glass as much as possible so that it can be bonded more easily. There is a need for an adhesive composition that can stably ensure sufficient adhesion.

  The present invention has been made in view of the above circumstances, and provides a urethane adhesive composition having stable and excellent adhesion to an adherend without applying a primer composition. Objective.

The present invention includes the following (1) to (4).
(1) a main agent containing a urethane prepolymer and an isocyanate silane compound;
A curing agent containing polybutadiene diol;
A urethane adhesive composition characterized by comprising:
(2) The urethane adhesive composition according to (1), wherein the content of the isocyanate silane compound is 1% by mass or more and 10% by mass or less in the main agent.
(3) The urethane adhesive composition according to the above (1) or (2), wherein the content of the polybutadiene diol is 5% by mass or more and 100% by mass or less in the curing agent.
(4) The urethane adhesive composition according to any one of (1) to (3), which is applied to an adherend formed of glass.

  According to the present invention, it is possible to stably and excellently adhere to an adherend without applying a primer composition.

FIG. 1 is a view showing a pair of test bodies used in Examples and Comparative Examples.

  The present invention will be described in detail below. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

  The urethane adhesive composition according to the present embodiment (hereinafter referred to as “the composition of the present embodiment”) includes a main agent containing a urethane prepolymer and an isocyanate silane compound, and a curing agent containing a polybutadiene diol. It is the urethane adhesive composition which has.

<Main agent>
The main agent contained in the composition of this embodiment contains a urethane prepolymer and an isocyanate silane.

(Urethane prepolymer)
The urethane prepolymer contained in the main component of the composition of the present embodiment is a prepolymer containing a plurality of isocyanate groups in the molecule at the molecular ends. The urethane prepolymer is preferably liquid at room temperature from the viewpoint of handling. The method for producing the urethane prepolymer is not particularly limited, and conventionally known methods can be mentioned. The urethane prepolymer is, for example, a reaction product obtained by reacting a polyisocyanate compound and a polyol compound so that isocyanate groups (NCO groups) are excessive with respect to hydroxy groups (OH groups). The urethane prepolymer generally contains 0.5% by mass or more and 10% by mass or less of NCO groups at the molecular ends. This isocyanate group may be bonded to either an aromatic hydrocarbon or an aliphatic hydrocarbon.

The polyisocyanate compound used when producing the urethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule. Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4 ' -MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, tolidine Aromatic polyisocyanates such as diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), triphenylmethane triisocyanate; Aliphatic polyisocyanates such as xamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanate methyl) ) Cycloaliphatic polyisocyanates such as cyclohexane (H ₆ XDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI); polyisocyanate compounds such as polymethylene polyphenylene polyisocyanates; carbodiimide-modified polyisocyanates of these isocyanate compounds; these isocyanate compounds Isocyanurate-modified polyisocyanates; these isocyanates Urethane prepolymer obtained a polyol compound to be described later compound is reacted; and the like. These polyisocyanate compounds can be used alone or in combination of two or more.

  The polyol compound used when producing the urethane prepolymer is not particularly limited, and may be, for example, any of polyether polyol, polyester polyol, acrylic polyol, polycarbonate polyol, and other polyols. These polyols can be used alone or in combination of two or more. Specific examples of the polyol compound include polypropylene ether diol, polyethylene ether diol, polypropylene ether triol, polytetramethylene glycol, polyethylene glycol (PEG), polypropylene glycol (PPG), polyoxyethylene glycol, polyoxypropylene glycol, polyoxy Propylene triol, polyoxybutylene glycol, polytetramethylene ether glycol (PTMG), polymer polyol, poly (ethylene adipate), poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate) ), Poly (neopentylene adipate), poly-ε-caprolactone, poly (hexamethylene carbonate) Sulfonate) and the like. A natural polyol compound such as castor oil may be used.

  The equivalent ratio of the polyol and the polyisocyanate in producing the urethane prepolymer is, for example, that the equivalent ratio of the isocyanate group in the polyisocyanate to the hydroxy group in the polyol (NCO group / OH group) is 1.2 to 2. 2 is preferable, and 1.5 to 1.8 is more preferable.

  The number average molecular weight of the urethane prepolymer is 2000 or more, preferably 2000 or more and 15000 or less, and more preferably 2000 or more and 10,000 or less.

  As a one-component moisture-curing urethane adhesive containing an isocyanate compound contained in the main component of the composition of the present embodiment, carbon black as a reinforcing agent is added to the urethane prepolymer, calcium carbonate and a catalyst are added as a filler, For example, a one-component moisture-curing urethane adhesive that is used with respect to the bonding surface of the inner and outer parts of the automobile for the purpose of bonding the inner and outer parts of the automobile is used. However, since it is a one-component moisture-curing urethane adhesive, it takes time to cure the inside, and it is not suitable for bonding parts and the like that require strength by curing for a short time.

(Isocyanate silane compound)
The isocyanate silane compound contained in the main component of the composition of the present embodiment is a compound obtained by modifying an isocyanate compound with a silane compound. In this embodiment, the isocyanate silane compound functions as an adhesion-imparting agent. In the present embodiment, the isocyanate silane compound is also referred to as an adhesion-imparting agent. The isocyanate silane compound is not particularly limited as long as it is a compound obtained by modifying an isocyanate compound with a silane compound. As an isocyanate silane compound, the isocyanate silane compound etc. which are represented by following formula (1) etc. are mentioned suitably, for example. The isocyanate silane compound represented by the following formula (1) includes a hexamethylene diisocyanate burette body (HDI burette body) having a structure represented by the following formula (2) and a structure represented by the following formula (3). It is obtained by reacting 3- (N-phenyl) aminopropyltrimethoxysilane having In the isocyanate silane compound represented by the following formula (1), one of the three NCOs in the molecule of the HDI buret body represented by the following formula (2) is substituted with 3- (N-phenyl) represented by the following formula (3). It is modified with one aminopropyltrimethoxysilane to be modified with isocyanate silane.

  The isocyanate silane compound represented by the above formula (1) is an HDI burette having the structure represented by the above formula (2) and 3- (N-phenyl) having the structure represented by the above formula (3). ) Aminopropyltrimethoxysilane is obtained by adding an isocyanate group / amino group (NCO group / NH group) within a range of 1.5 / 1.0 or more and 9.0 / 1.0 or less. The NCO group / NH group is a structure represented by the above formula (2) per amino group in 3- (N-phenyl) aminopropyltrimethoxysilane having a structure represented by the above formula (3). The ratio of isocyanate groups in HDI having

  The NCO group / NH group comprises an HDI burette having a structure represented by the above formula (2) and 3- (N-phenyl) aminopropyltrimethoxysilane having a structure represented by the above formula (3). Although it is made to react so that it may become in the range of 1.5 / 1.0 or more and 9.0 / 1.0 or less, Preferably it is 1.5 / 1.0-6.0 / 1.0, and more Preferably it is 3.0 / 1.0-6.0 / 1.0. If the NCO group / NH group is within the above range, the adhesion of the adhesion-imparting agent is sufficiently exhibited. At this time, the HDI burette body having the structure represented by the above formula (2) may remain unreacted.

  The content of the isocyanate silane compound is 1 part by mass or more and 10 parts by mass or less, preferably 1.5 parts by mass or more and 8 parts by mass or less, more preferably 1.5 parts by mass or more with respect to 100 parts by mass of the main agent. 5 parts by mass or less. When the content of the isocyanate silane compound is 1 part by mass or more, an effect of improving the adhesive performance is obtained. In addition, when the content of the isocyanate silane compound is 10 parts by mass or less, the cured product of the composition of the present embodiment is hardened, and foaming is suppressed and the increase in cost is suppressed. it can. Therefore, when the content of the isocyanate silane compound is within the above range, the composition of the present embodiment is a primer composition for an adherend made of a material such as glass or polypropylene resin or an olefin resin. Stable and excellent adhesion without using.

  The production of the isocyanate silane compound can be carried out in the same manner as the production of ordinary polyurethane. For example, the HDI burette having the structure represented by the above formula (2) with the above-mentioned equivalent ratio and the above formula (3) ) With 3- (N-phenyl) aminopropyltrimethoxysilane having a structure represented by a reaction temperature of 50 ° C. to 60 ° C. Moreover, urethanation catalysts, such as an organic tin compound, organic bismuth, and an amine, etc. can also be used as needed.

By containing an isocyanate silane compound in the main component, the composition of the present embodiment can stably have excellent adhesiveness without using a primer composition. In particular, the composition of the present embodiment has excellent adhesiveness to adherends made of materials such as glass and olefin resins such as polypropylene resin. The composition of the present embodiment utilizes compatibility between the nonpolar skeleton of polybutadiene diol, which is a curing component of the curing agent, and the adhesion-imparting agent contained in the main agent. In the adhesion, it is necessary that the adhesion imparting agent migrates to the surface of the adhesive, that is, between the glass or olefin resin and the adhesive. Since the one-component adhesive has a slow internal curing, the adhesion imparting agent may be gradually transferred. However, since the two-component adhesive cures quickly, it is necessary to transfer the adhesion-imparting agent to the surface immediately after mixing. Since the adhesion-imparting agent and the polybutadiene diol in the curing agent are poorly compatible, the adhesion-imparting agent moves quickly to the adhesive surface, and the isocyanate silane compound easily migrates to the interface. And after the methanol (CH ₃ OH) generated when the hydroxyl group (OH group) of trimethoxysilane of the isocyanate silane compound reacts with the OH group of glass is removed, the hydroxyl group (OH group) formed on trimethoxysilane and The OH group of the glass reacts to remove water (H ₂ O). Thereby, an O—Si group is formed between the OH group of trimethoxysilane and the OH group of glass. It is thought that this O-Si group imparts high adhesiveness. As a result, it is considered that the isocyanate silane compound and the glass are more strongly bonded and the adhesiveness is increased. On the other hand, it is considered that the adhesion with the resin is enhanced by the bonding form of the NCO group in the adhesion-imparting agent and the polar part in the resin.

<Curing agent>
The curing agent contained in the composition of this embodiment contains polybutadiene diol.

(Polybutadiene diol)
The polybutadiene diol contained in the curing agent of the composition of the present embodiment is a kind of polyol compound. In the present embodiment, the polybutadiene diol promotes the transition of the adhesive surface (interface between the adhesive and glass or resin) of the adhesion imparting agent contained in the crosslinking agent and the main agent. Polybutadiene diol may be used in combination with other polyol compounds. As other polyol compounds, for example, polypropylene ether diol, polyethylene ether diol, polypropylene ether triol, polytetramethylene glycol, polyethylene glycol (PEG), polypropylene glycol (PPG), polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene Triol, polyoxybutylene glycol, polytetramethylene ether glycol (PTMG), polymer polyol, poly (ethylene adipate), poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate) , Poly (neopentylene adipate), poly-ε-caprolactone, poly (hexamethylene carbonate) Sulfonate) and the like. Moreover, a diol compound obtained by using natural castor oil as a raw material, a rosin diol (tackfire) using pine resin as a raw material, and the like can be exemplified. These diol compounds may be used alone or in combination of two or more.

  In the present embodiment, among these diol compounds, it is necessary to contain polybutadiene diol from the viewpoints of water resistance, adhesiveness, physical properties, and the like. The polybutadiene diol is one in which a hydroxyl group (OH group) is bonded to the end of the polybutadiene skeleton.

  The polybutadiene diol has a number average molecular weight of preferably 200 or more and 10,000 or less, more preferably 1000 or more and 3000, from the viewpoint of improving the excellent and stable adhesion to the adherend of the composition of the present embodiment. The following is preferable.

  The content of the polybutadiene diol is 5 parts by mass or more and 100 parts by mass or less, preferably 30 parts by mass or more and 60 parts by mass or less, more preferably 40 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the curing agent. It is. When the content of the polybutadiene diol is less than 5 parts by mass or more than 100 parts by mass, the curability of the adhesive and the transferability to the surface of the adhesion imparting agent cannot be balanced. The composition of this embodiment has stable and excellent adhesiveness without using a primer composition to an adherend made of a material such as glass or polypropylene resin or other olefinic resin.

(filler)
The composition of this embodiment may contain a filler in the main agent and the curing agent. The filler contained in the main agent and the curing agent is not particularly limited. For example, calcium carbonate, aluminum hydroxide, carbon black, white carbon, silica, glass, kaolin, talc (magnesium silicate), fumed silica, precipitated Silica, anhydrous silicic acid, hydrous silicic acid, clay, calcined clay, bentonite, glass fiber, asbestos, glass filament, ground quartz, diatomaceous earth, aluminum silicate, zinc oxide, magnesium oxide, titanium oxide, or surface treatment thereof Inorganic fillers such as carbonates; carbonates, organic bentonite, high styrene resin, coumarone-indene resin, phenol resin, formaldehyde resin, modified melamine resin, cyclized rubber, lignin, ebonite powder, shellac, cork powder, bone powder, wood powder , Cellulose powder, Organic fillers such as coconut palm, wood pulp, etc .; inorganic pigments such as lamp black, titanium white, bengara, titanium yellow, zinc white, red lead, cobalt blue, iron black, aluminum powder and neozabon black RE, neoblack RE And organic pigments such as Orazole Black CN, Orazole Black Ba (all manufactured by Ciba-Geigy) and Spiron Blue 2BH (manufactured by Hodogaya Chemical Co., Ltd.). Of these, carbon black and calcium carbonate are preferably used in order to impart desired characteristics. These carbon black and calcium carbonate are not particularly limited, and commercially available products can be used. For example, carbon black includes N110, N220, N330, N550, N770, etc., or a mixture thereof according to the American Society for Testing Materials standard, and calcium carbonate includes heavy calcium carbonate, precipitated calcium carbonate, and the like. These fillers can be used singly or in combination of two or more.

(catalyst)
The composition of this embodiment may contain a catalyst in one or both of the main agent and the curing agent. The catalyst is not particularly limited as long as it can react with the polymer contained in the main agent and the curing agent. The catalyst is not particularly limited, for example, stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, dibutyltin dimaleate, dibutyltin bisacetylacetonate, dibutyltin silylate, Metal catalysts such as bismuth octylate; divalent organic tin compounds such as tin octoate, tin octylate, tin butanoate, tin naphthenate, tin caprylate, tin oleate, tin laurate; dibutyltin dioctoate, dibutyltin Dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dibutyltin dioleate, dibutyltin benzoate, dioctyltin dilaurate, dioctyltin diversate, diphenyltin diacetate, dibutyltin diester Tetravalent organic tin compounds such as toxide, dibutyltin oxide, dibutyltin bis (triethoxysilicate), reaction product of dibutyltin oxide and phthalate; dibutyltin diacetylacetonate, dibutyltin bis (acetylacetonate), etc. Tin-based chelate compounds such as: primary amines such as butylamine, hexylamine, octylamine, dodecylamine, oleylamine, cyclohexylamine, and benzylamine; secondary amines such as dibutylamine; diethylenetriamine, triethylenetetramine, guanidine, Polyamines such as diphenylguanidine and xylylenediamine; triethylenediamine and derivatives thereof, 2-methyltriethylenediamine, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole Cyclic amines such as 1,8-diazabicyclo [5.4.0] -7-undecene; aminoalcohol compounds such as monoethanolamine, diethanolamine and triethanolamine; 2,4,6-tris (dimethylaminomethyl) phenol Amine compounds such as aminophenol compounds and carboxylic acid salts thereof; quaternary ammonium salts such as benzyltriethylammonium acetate; low molecular weight amide resins obtained from excess polyamines and polybasic acids; excess polyamines and epoxy compounds The reaction product etc. are mentioned. Among these, a tin-based catalyst and an amine-based catalyst are preferable from the viewpoint of having a small amount and a large catalytic ability. These catalysts can be used singly or in combination of two or more.

  The composition of this embodiment can be obtained by mixing a main ingredient, a hardening | curing agent, and each said arbitrary component. The composition of this embodiment can contain an additive in the range which does not impair the objective of this invention as needed other than a main ingredient, a hardening | curing agent, and each said arbitrary component. As additives, in addition to the above fillers and curing accelerators (catalysts), for example, curing agents, plasticizers, reactive diluents, thixotropic agents, silane coupling agents, pigments, dyes, anti-aging agents, Examples thereof include an antioxidant, an antistatic agent, a flame retardant, a drying oil, an adhesion-imparting agent, a dispersant, a dehydrating agent, an ultraviolet absorber, and a solvent. Two or more of these may be contained. Additives and the like can be kneaded by a general method to form a composition and used for crosslinking. The blending amounts of these additives can be conventional conventional blending amounts as long as the object of the present embodiment is not violated.

  The usage method of the composition of this embodiment is not specifically limited. For example, after sufficiently mixing the above main agent and curing agent using a rotary mixer, static mixer, etc., after applying to the adherend, it is bonded to the non-adherent, and both adherends are pressure-bonded and bonded. Form a structure.

  Thus, the composition of the present embodiment contains a main agent containing a urethane prepolymer and an isocyanate silane compound, and a curing agent containing a polybutadiene diol, the isocyanate silane compound as an adhesion promoter, and a polybutadiene diol. It is a urethane adhesive composition contained as a crosslinking agent. The main component contains a predetermined amount of an isocyanate silane compound and the curing agent contains a predetermined amount of polybutadiene diol, so that it has stable and excellent adhesiveness even when the primer composition is not applied to the surface of the adherend. Can do. In particular, the composition of this embodiment can be satisfactorily adhered by applying and adhering the composition of this embodiment to a glass substrate, so that the primer composition is not applied to the surface of the adherend. Even if it is a case, it can stably have excellent adhesiveness.

  The composition of this embodiment is mainly used as an adhesive composition to be applied to objects to be bonded such as automobile interior and exterior parts such as automobile bodies, front doors, rear doors, back doors, front bumpers, rear bumpers, and rocker moldings. be able to. In particular, the composition of the present embodiment can be suitably used as a window sealant because it can improve the adhesion between a glass member such as an automobile window glass and a coating member such as a body. In addition, the composition of the present embodiment is a structure formed using a resin and a structure formed using a metal, an adhesive property between structures formed using a material such as an automobile resin, etc. Therefore, it can be suitably used as an automotive structural adhesive. Furthermore, the composition of the present embodiment is a structure formed by using a material such as plastic or polypropylene resin such as polypropylene resin subjected to surface treatment such as flame treatment, corona treatment, plasma treatment, and intro treatment. Since the adhesiveness can be improved, it can be suitably used as an adhesive for such a structure.

  As described above, since the composition of the present embodiment has the above-described characteristics, it is used for bonding automobiles, vehicles (bullet trains, trains), ships, aircraft, architecture / civil engineering, electronics, space industry, and other industrial products. In particular, it can be suitably used as an adhesive for the construction of interior and exterior parts of automobiles and vehicles such as automobiles and vehicle bodies and glass plates.

  Although the composition of the present embodiment has been described in detail, the present invention is not limited to the above, and various changes and improvements may be made without departing from the gist of the present invention.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Production of urethane prepolymer>
600 g of polypropylene ether triol having a number average molecular weight of 5000 (G-5000, trade name “EXCENOL5030”, manufactured by Asahi Glass Co., Ltd.), and 300 g of polypropylene ether diol having a number average molecular weight of 2000 (D-2000, trade name “EXCENOL2020”, Asahi Glass Co., Ltd.) Made into a flask, heated to 100 ° C. to 130 ° C., stirred while degassing, and dehydrated until the water content became 0.01% or less. Thereafter, the mixture is cooled to 90 ° C., and diphenylmethane diisocyanate (MDI, trade name “Sumijoule 44S”, manufactured by Sumitomo Bayer Japan Co., Ltd.) is added in such an amount that the NCO group / OH group equivalent ratio (NCOmol / OHmol) is 1.70. After the addition, the reaction was allowed to proceed under a nitrogen atmosphere for about 24 hours to produce urethane prepolymers shown in Tables 1 to 3.

<Preparation of main agent>
Each component of main agent 1 (S-1) to main agent 3 (S-3) shown in Tables 1 to 3 is added in the amount (parts by mass) shown in the same table, and deaerated with a mixer (5 L level). Then, the mixture was uniformly mixed for about 1 hour to prepare Main Agent 1 (S-1) to Main Agent 3 (S-3) shown in Tables 1 to 3. Tables 1 to 3 show the blending amount (parts by mass) of each component in each main ingredient.

<Production of curing agent>
Each component of the curing agents (B-1 to B-7) shown in Tables 1 to 3 is blended in the blending amounts (parts by mass) shown in the table, and about 1 while degassing with a mixer (5 L level). It mixed uniformly for time and produced each hardening | curing agent (B-1 to B-7) shown in Tables 1 to 3. Tables 1 to 3 show the blending amount (parts by mass) of each component in each curing agent.

<Preparation of adhesive>
Main ingredients 1 to 3 (S-1 to S-3) and curing agents (B-1 to B-7) obtained above were uniformly mixed at a mixing ratio (mass mixing ratio) of 10: 1, Each adhesive of Examples and Comparative Examples shown in Tables 1 to 3 was prepared. Tables 1 to 3 show combinations of main agents and curing agents in Examples and Comparative Examples shown in Tables 1 to 3.

<Evaluation>
About each adhesive agent of each Example obtained by the above and a comparative example, the adhesiveness with the glass after hardening and the fracture | rupture form were evaluated by the method shown below.

[Preparation of specimen]
First, the test body obtained using each adhesive of the Example obtained by the above and a comparative example was produced. FIG. 1 is a diagram showing a pair of test bodies used in each example and comparative example. As shown in FIG. 1, an electrodeposition coating plate 11 (25 mm × 150 mm × 3 mm) and a glass substrate 12 (25 mm × 150 mm × 3 mm) were prepared as adherends. Subsequently, the adhesive composition 14 of each Example and Comparative Example shown in Tables 1 to 3 is bonded to the joint 13 (25 mm × 10 mm) on the opposite surface side between the electrodeposition coating plate 11 and the glass substrate 12. The coating composition 14 was applied to a thickness of about 3 mm, the electrodeposition coating plate 11 and the glass substrate 12 were pressure-bonded, cured at 60 ° C. for 30 minutes, and then 72 ° C. at 20 ° C. and 60% RH. The adhesive composition 14 was cured by curing for a time, and a test body 15 was produced.

[Adhesiveness]
For the evaluation of adhesiveness, the shear strength was measured using the test body 15. Moreover, the fracture | rupture form in a shear test was observed visually. The evaluation results are shown in Tables 1 to 3.

(Shear strength)
The shear strength was measured according to JIS K6850-1999 under the conditions of 20 ° C. and 60% RH at a tensile rate of 50 mm / min. The evaluation results are shown in Tables 1 to 3.

(Destruction mode)
The evaluation of the fracture mode is based on the fracture mode of the cured product (adhesive) of each adhesive composition 14 after shearing the above-mentioned surface-treated electrodeposition coating plate 11 and the glass substrate 12 in the shear strength test. Evaluation was made by visual observation. The evaluation of the breaking mode was performed by expressing the breaking mode of the adhesive of the adhesive composition 14 with respect to the bonding area and the ratio (%) of the area by numbers. The higher the ratio of cohesive failure (CF), the better the adhesiveness of the adhesive of the adhesive composition 14, and the higher the ratio of the interface composition (AF) between the adhesive of the adhesive composition 14 and the glass substrate 12, the higher the adhesion. It was evaluated that the adhesive property of the adhesive composition 14 was poor. Further, when the above two destruction states coexist, the ratio of the area is described as, for example, “CF50AF50”. Tables 1 to 3 show the evaluation results of the fracture modes.

(Adhesion evaluation criteria)
The case where the shear strength was 3.0 MPa or more and the fracture state was CF100 (complete adhesive fracture mode) was evaluated as good adhesion.

The components shown in Tables 1 to 3 are as follows.
(Main agent: S-1 to S-3)
Urethane prepolymer: Urethane prepolymer obtained above, manufactured by Yokohama Rubber Co., Ltd. Isocyanate silane compound: HDI burette ("D-165N", manufactured by Mitsubishi Chemical Corporation) and 3- (N-phenyl) Reaction product with aminopropyltrimethoxysilane (“Y9669”, manufactured by Momentive Performance Materials Japan GK) • Plasticizer: diisononyl adipate (“DINA”, manufactured by J Plus)
-Carbon black: "MA600", manufactured by Mitsubishi Chemical Corporation-Calcium carbonate: "Super S", manufactured by Maruo Calcium Co., Ltd.-Amine catalyst: 2-methyltriethylenediamine ("ME-DABCO", manufactured by Air Products Japan Co., Ltd.)
-Tin catalyst: Dibutyltin diacetate ("U-200", manufactured by Nitto Kasei Co., Ltd.)
(Curing agents: B-1 to B-7)
Polyol compound 1: Polypropylene glycol (“EXCENOL 2020”, number average molecular weight: 2000, manufactured by Asahi Glass Co., Ltd.)
Polyol compound 2: Polypropylene glycol ("EXCENOL 1020", number average molecular weight: 1000, manufactured by Asahi Glass Co., Ltd.)
-Diol compound 1: Hydroxyl-terminated liquid polybutadiene ("poly bd R-15HT", manufactured by Idemitsu Kosan Co., Ltd.)
-Diol compound 2: Hydroxyl-terminated liquid polybutadiene ("poly bd R-45HT", manufactured by Idemitsu Kosan Co., Ltd.)
・ Calcium carbonate: “Calfine 500”, manufactured by Maruo Calcium Co., Ltd. ・ Amine catalyst: 2-methyltriethylenediamine (“ME-DABCO”, manufactured by Air Products Japan Co., Ltd.)
Tin catalyst: Dibutyltin diacetate (“U-200”, manufactured by Nitto Kasei Co., Ltd.)

  From the results shown in Tables 1 to 3, in Examples 1-1 to 1-5, 2-1 to 2-5, and 3-1 to 3-5, curing with any of the main agents S-1 to S-3 The adhesive of the test body 15 obtained by using the adhesive composition 14 in combination with any of the agents B-1 to B-3, B-6, or B-7 is 20 ° C. and 60% RH. The shear strength after curing for 72 hours was 4.1 MPa or more. Further, the fracture mode of the adhesive was all cohesive fracture CF100. Therefore, the adhesive obtained by using any one of the main agents S-1 to S-3 and any one of the curing agents B-1 to B-3, B-6 or B-7, All were confirmed to have stable and excellent adhesiveness even without applying the primer composition.

  On the other hand, in Comparative Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, one of the main agents S-1 to S-3, a curing agent B-4, The adhesive of the test body 15 obtained using the adhesive composition in combination with any of B-5 has a shear strength of 2.8 MPa or less after curing for 72 hours at 20 ° C. and 60% RH. Yes, the fracture mode of the adhesive was CF50AF50 or AF100. Moreover, most of the adhesives were broken at the interface between the electrodeposition coated plate 11 and the glass substrate 12. Therefore, the combination of any one of the main agents S-1 to S-3 and any one of the curing agents B-4 and B-5 did not have good adhesion to glass, and the strength was not sufficient. Therefore, any of the adhesives obtained using the adhesive compositions of Comparative Examples 1-1, 1-2, 2-1, 2-2, 3-1, 3-2 may be inferior in adhesiveness. confirmed.

  Therefore, the adhesive obtained by combining any one of the main agents S-1 to S-3 and any one of the curing agents B-1 to B-3, B-6 or B-7 is the main agent S-1 to S. -3 and any one of curing agents B-4 and B-5 in combination, the strength of the adhesive is higher than that of the adhesive, and the electrodeposition coating plate 11 and the glass substrate 12 can be used without using a primer composition. Can be stably bonded.

  Therefore, the composition of the present embodiment includes a main agent containing a urethane prepolymer and a predetermined amount of an isocyanate silane compound and a curing agent containing a predetermined amount of polybutadiene diol. It has been found that an adhesive having a stable and excellent adhesion to an adhesive such as a glass substrate can be obtained without using a primer composition.

DESCRIPTION OF SYMBOLS 11 Electrodeposition coating board 12 Glass substrate 13 Joint part 14 Adhesive composition 15 Test body

Claims (4)

A main agent containing a urethane prepolymer and an isocyanate silane compound;
A curing agent containing polybutadiene diol;
A urethane adhesive composition characterized by comprising:   The urethane adhesive composition according to claim 1, wherein the content of the isocyanate silane compound is 1% by mass or more and 10% by mass or less in the main agent.   The urethane adhesive composition according to claim 1 or 2, wherein the content of the polybutadiene diol is 5% by mass or more and 100% by mass or less in the curing agent.   The urethane adhesive composition according to claim 1, wherein the urethane adhesive composition is applied to an adherend formed of glass.

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