JPH0747726B2 - Adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a photocurable type used for bonding metal parts, hermetically sealing, preventing loosening of fastening materials such as bolts, or fixing fitting parts. The present invention relates to an adhesive composition.

[Background of the Invention]

It does not cure with a photocurable adhesive composition while it is shielded from light and is stable for a long period of time, but generally has the property of being easily polymerized and cured by irradiation with light such as ultraviolet rays. It is a curable adhesive composition.

It goes without saying that this kind of adhesive composition is required to be cured rapidly under light irradiation and that the photocured product has high flexibility as a stress relaxation cured product.

[Conventional technology]

Conventionally known as this kind of adhesive composition is a composition containing a photopolymerization initiator as a polymerization initiator in a composition containing a radically polymerizable (meth) acrylic acid ester monomer as a main component. is there.

Such an adhesive composition does not cure while being shielded from light and is stable for a long period of time, but when used, it is polymerized and cured by irradiation with light such as ultraviolet rays.

[Problems to be Solved by the Invention]

However, since the above-mentioned conventional adhesive composition has hard and brittle physical properties after curing, there is a problem that sufficient reliability as a stress relaxation cured product cannot be obtained.

Although an adhesive composition which gives a cured product having some flexibility in order to improve the hard and brittle physical properties of the cured product of the above adhesive composition has been conventionally provided, the curing rate under light irradiation is slow and practical. It has become a big problem when it comes to commercialization.

[Means for Solving the Problems]

As a means for solving the above problems, the present invention has a (meth) acryloyloxy group which is a reaction product of a (meth) acrylate (A) having a hydroxyl group, an organic polyisocyanate (B), and a polycarbonate diol (C). Polycarbonate diol-modified urethane prepolymer [I]
Is a reaction product of (meth) acrylate (A) having one or more of the above and / or a hydroxyl group, an organic polyisocyanate (B), a polycarbonate diol (C), and a polyol (D) (meta). ) One or more of the polycarbonate diol-modified urethane prepolymers [II] having an acryloyloxy group, and the above-mentioned polycarbonate diol-modified urethane prepolymers [I] and [I] having a (meth) acryloyloxy group.
(Meth) acrylic acid ester compounds other than I] [III]
The present invention provides an adhesive composition containing one or more of the above and a photopolymerization initiator or [IV] and containing no organic peroxide.

The (meth) acrylate (A) is a generic term for acrylates and methacrylates, and the polycarbonate diol-modified urethane prepolymer [I] is a generic term for polycarbonate diol-modified urethane prepolymers having a (meth) acryloyloxy group. The (meth) acrylic acid ester-based compound [III] will be described later (meth) acrylic acid ester-based compounds (1) to (1
It is one or more kinds of (meth) acrylic acid ester compounds selected from the group consisting of 1).

The details of each component constituting the adhesive composition of the present invention will be described below.

<Polycarbonate diol-modified urethane prepolymer [I]> The urethane prepolymer [I] is a reaction product of (meth) acrylate (A) having a hydroxyl group, organic polyisocyanate (B), and polycarbonate diol (C).

Specific examples of the synthetic raw materials (A), (B), and (C) are as follows.

[(Meth) Acrylate (A) Having Hydroxyl Group]

Specific examples of the (meth) acrylate (A) having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate and hydroxyoctyl (meth). ) Acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and 2-hydroxy-3-chloropropyl (meth) acrylate.

[Organic polyisocyanate (B)]

Specific examples of the organic polyisocyanate (B) include toluene diisocyanate, 4,4'-diphenyl diisocyanate,
4,4'-diphenylmethane diisocyanate, dianidine diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenyl ether diisocyanate, p-phenylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate, cyclohexylene diisocyanate , Nonamethylene diisocyanate, octadecamethylene diisocyanate, 2-chloropropane diisocyanate, 2,2'-diethyl ether diisocyanate, tetrachlorophenylene diisocyanate, xylene diisocyanate, and 1,4,3-
Low molecular weight organic polyisocyanates, such as heptene diisocyanate, and excess amounts of these low molecular weight organic polyisocyanates, as already known, can be combined with primary amines, secondary amines, or polyhydric alcohols such as glycerol, polyoxy Add ethylene oxide and / or propylene oxide to ethylene triol, polyoxypropylene triol, polyoxyethylene tetraol, polyoxypropylene tetraol, polypropylene glycol, polyethylene glycol, polycaprolactone polyol, polytetramethylene ether glycol, bisphenol A There is a high molecular weight organic polyisocyanate obtained by reacting with a polyhydric alcohol such as an ether type glycol obtained as described above.

Particularly preferred organic polyisocyanates in the present invention are toluene diisocyanate, 4,4'-diphenylmethane diisocyanate and hexamethylene diisocyanate.

[Polycarbonate diol (C)]

The polycarbonate diol is a C _{2 to} C ₁₂ alkylene group, and / or a C _{1 to} C ₂₂ alkyl group, and / or a C _{6 to} C ₂₂ aromatic hydrocarbon group, and / or a C ₆
To C ₂₂ carbonic acid ester having cycloparaffinic hydrocarbon group and C _{2 to} C ₂₂ alkylene group, and / or C _{1 to} C
It is obtained by reacting a diol having a ₂₂ alkyl group and / or a C _{6 to} C ₂₂ aromatic hydrocarbon group, and / or a C _{6 to} C ₂₂ cycloparaffinic hydrocarbon group.

Specific examples of the carbonic acid ester include ethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and dicyclohexyl carbonate.

Further, specific examples of the diol include 1,6-hexanediol, 1,
4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 1,5-pentanediol, polyoxyethylene diol, polyoxypropylene diol, polyoxybutylene diol, polycaprolactone diol,
Examples include trimethylhexanediol and 1,4-butanediol.

A particularly suitable production method of the polycarbonate diol-modified urethane prepolymer [I] of the present invention is a predetermined amount of organic polyisocyanate (B) and polycarbonate diol (C).
Are first reacted with each other to produce a polycarbonate diol-modified urethane prepolymer (E) having an unreacted isocyanate group, and then the urethane prepolymer (E)
And (meth) acrylate (A) having a predetermined amount of hydroxyl groups
Is a method of reacting with.

(B) + (C) = (E) → (E) + (A) = [I] The reaction temperature during the production of the polycarbonate diol-modified urethane prepolymer [I] is preferably 120 ° C. or lower. If the temperature is too high, it may cause thickening of the reaction product or gelation during the reaction. If the reaction temperature is too low, the viscosity of the reaction product will be high, and the unreacted raw materials will be insufficiently dispersed / mixed to make smooth reaction difficult. Therefore, it is preferably carried out at 50 ° C to 120 ° C, more preferably 55 ° C to 100 ° C. It is preferable. The synthesis of the polycarbonate diol-modified urethane prepolymer [I] is carried out at each stage with the group -NCO.
When the infrared absorption spectrum analysis is performed on the group -NCO, the group -NCO exhibits strong absorption at around 2250 cm ^-1 , and therefore the progress of the reaction depends on the group -NCO in the reaction product. It can be easily confirmed by performing an external absorption spectrum analysis and tracing the consumption amount from the intensity change of the absorption characteristic, and when the consumption of the group -NCO is stopped, it may be set as the end point of each reaction step. Examples of the catalyst for smoothly proceeding the reaction include metal compounds such as tertiary amines such as triethylenediamine and tin such as dibutyltin dilaurate. To adjust the reaction rate, the latter dibutyltin dilaurate is preferable, and the addition amount thereof is 50 to 2000 ppm with respect to 100 parts by weight of the reaction product.
Is preferable, and more preferably 1 per 100 parts by weight of the reactant.
It is from 00 to 1500 ppm. Further, as the radical polymerization inhibitor, hydroquinone monomethyl ether, phenothiazine and the like may be added in appropriate amounts according to the reaction conditions. Further, when the viscosity of the reaction product becomes too high, an organic solvent having no active hydrogen group such as toluene or acetone, or a (meth) acrylate having no active hydrogen group may be used as a reaction diluent.

<Polycarbonate diol-modified urethane prepolymer [II]> The urethane prepolymer [II] is a hydroxyl group-containing (meth) acrylate (A), an organic polyisocyanate (B), a polycarbonate diol (C), and a polyol (D). It is a reaction product with.

The synthetic raw materials (A), (B), and (C) are the same as those of the urethane prepolymer [I], and specific examples of the polyol (D) are as follows.

[Polyol (D)]

Specific examples of the polyol (D) include 1,6-
Hexanediol, 1,4-cyclohexanedimethanol,
3-methyl-1,5-pentanediol, 1,5-pentanediol, polyoxyethylene diol, polyoxypropylene diol, polyoxybutylene diol, polycaprolactone diol, trimethylhexane diol, 1,4-butane diol, etc. There, as the trihydric or higher polyol, trimethylolethane, pentaerythritol, trimethylolpropane, polyoxyethylenetriol, polyoxypropylenetriol, trishydroxyethylisocyanurate, polyoxyethylenetetraol, polyoxypropylenetetraol, There are glycerin, polyphosphoric acid and the like.

A particularly suitable production method of the polycarbonate diol-modified urethane prepolymer [II] of the present invention is a predetermined amount of organic polyisocyanate (B) and polycarbonate diol (C).
Are first reacted with each other to produce a polycarbonate diol-modified urethane prepolymer (E) having an unreacted isocyanate group, and then the urethane prepolymer (E)
And (meth) acrylate (A) having a predetermined amount of hydroxyl groups
To produce a (meth) acryloyloxy compound (F) having an unreacted isocyanate group, and further reacting the (meth) acryloyloxy compound (F) with a predetermined amount of polyol (D). is there.

(B) + (C) = (E) → (E) + (A) = (F) →
(F) + (D) = [II] The reaction conditions in the above production method are the same as those for the urethane prepolymer [I].

<(Meth) acrylic acid ester compound [III]> The (meth) acrylic acid ester compound [III] means a (meth) acrylic acid ester compound other than the urethane prepolymers [I] and [II]. The present invention improves the cohesive force and interfacial adhesive force of the adhesive of the present invention, and is, for example, one or two selected from the group consisting of the following (meth) acrylic acid ester compounds (1) to (11). The above-mentioned (meth) acrylic acid ester compounds can be mentioned.

[(Meth) acrylic ester compound (1)] The (meth) acrylic ester compound (1) has the following general formula.

In the formula, R ₁ is hydrogen or —CH ₃ , and R ₂ is a straight or branched alkyl group having 2 to 4 carbon atoms in which one or more hydrogen atoms are replaced with —OH and / or halogen. Indicates an alkyl group.

The above-mentioned (meth) acrylate (1) is specifically 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,2-dihydroxyethyl (meth) acrylate, 3-chloro-2-hydroxy. Examples include propyl (meth) acrylate.

[(Meth) acrylic ester compound (2)] The (meth) acrylic ester compound (2) has the following general formula.

In the formula, R ₃ is hydrogen or —CH ₃ , R ₄ is hydrogen, —CH ₃ , —C ₂ H ₅ ,
-CH ₂ OH, or R ₅ is hydrogen, chlorine, -CH ₃ or -C ₂ H _5, R ₆ is hydrogen, -OH,
Or , M is an integer of 1 to 8, n is an integer of 1 to 20, and p is 0.
Or 1 is shown.

The (meth) acrylate (2) is specifically diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate. , Dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, diglycerol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, di-
Examples thereof include glycerol tetra (meth) acrylate.

[(Meth) acrylic ester compound (3)] The (meth) acrylic ester compound (3) has the following general formula.

In the formula, R ₇ is hydrogen or —CH ₃ , R ₈ is hydrogen or 1 to 4 carbon atoms.
Is a linear or branched alkyl group, R ₉ is a linear or branched alkylene group having 2 to 4 carbon atoms, and m is an integer of 1 to 10.

The (meth) acrylate (3) is specifically 2,2-
Bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-acryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxytriethoxyphenyl) propane, 2,2-bis ( 4-acryloxypentaethoxyphenyl) propane, 2-2bis (4-methacryloxyhexaethoxyphenyl) propane, 2,2-bis (4-acryloxyheptaethoxyphenyl) propane, 2,2-bis (4-methacryl Roxyoctaethoxyphenyl) propane, 2,2-bis (4-acryloxydipropoxyphenyl) propane, 2,2-bis (4-methacryloxytripropoxyphenyl) propane, 2,2-bis (4-acryloxydipto Xyphenyl) propane, 2,2-bis (4-methacryloxyoctabutoxyphenyl) propane, 2- (4- Takuri Loki Siji ethoxyphenyl) -2- (4-methacryloxy triethoxy phenyl) propane, 2- (4-acryloxydiethoxyphenyl isopropoxyphenyl) -2- (4-acryloxy triethoxy) propane and the like.

[(Meth) acrylic ester compound (4)] The (meth) acrylic ester compound (4) has the following general formula.

In the formula, R ₁₀ is hydrogen or —CH ₃ , R ₁₁ is a linear or branched alkylene group having 1 to 4 carbon atoms, and n is 0 or an integer of 1 to 10.

The (meth) acrylate (A) is specifically dicyclopentenyl (meth) acrylate, dicyclopentenyloxymethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyloxypropyl (meth). Acrylate and the like.

[(Meth) acrylic ester compound (5)] The (meth) acrylic ester compound (5) has the following general formula.

In the formula, R ₁₂ is hydrogen or —CH ₃ , R ₁₃ is hydrogen or 1 to 1 carbon atoms.
18 straight or branched alkyl groups, or 5 to 20 carbon atoms
Is a cyclic alkyl group, a phenyl group, a tetrahydrofurfuryl group, or a linear or branched alkyl group having 5 to 20 carbon atoms having these groups.

The (meth) acrylate (5) is specifically methacrylic acid, acrylic acid, methyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl ( Examples thereof include meth) acrylate and benzyl (meth) acrylate.

[(Meth) acrylic ester compound (6)] The (meth) acrylic ester compound (6) has the following general formula.

In the formula, R ₁₄ is hydrogen or —CH ₃ , R ₁₅ is a substituted alkylene group obtained by substituting —OH for hydrogen at any position of a linear or branched alkylene group having 3 or 4 carbon atoms, and R ₁₆ is 1 to 3 carbon atoms. 18 straight or branched alkyl groups are shown.

Specific examples of the (meth) acrylate (6) include 2-hydroxy-3-phenoxypropyl (meth) acrylate, cyclohexanoxy-β-hydroxypropyl (meth) acrylate, tetrahydrofurfuroxy-β-hydroxypropyl (meth). ) Acrylate, nonyloxy-β-hydroxypropyl (meth) acrylate and the like.

[(Meth) acrylic ester compound (7)] The (meth) acrylic ester compound (7) has the following general formula.

In the formula, R ₁₇ is hydrogen or —CH ₃ , and R ₁₈ is a linear or branched alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aryl group, an aralkyl group, or a linear or branched alkoxyalkyl group.

Specific examples of the (meth) acrylate (7) include methoxycarbonylmethyl (meth) acrylate, ethoxycarbonylmethyl (meth) acrylate, heptoxycarbonylmethyl (meth) acrylate, and isopropoxycarbonylmethyl (meth) acrylate. To be

[(Meth) acrylic acid ester compound (8)] In the formula, R ₁₉ is hydrogen or —CH ₃ , and R ₂₀ is a linear or branched alkylene group having 2 to 4 carbon atoms, m is an integer of 1 to 10 and n is 1 or 2.

[(Meth) acrylic ester compound (9)] The (meth) acrylic ester compound (9) has the following general formula.

In the formula, R ₂₁ is hydrogen or -CH ₃ , m is an integer of 1 to 10, and n is 1.
Or 2.

Specific examples of the (meth) acrylates (8) and (9) include acidtophosphoxyethyl (meth) acrylate, 3-chloro-2-acitophosphooxypropyl (meth) acrylate, and acitophosphooxypropyl (meth) acrylate. Examples thereof include (meth) acrylate.

[(Meth) acrylic acid ester compound (10)] A reaction product of a (meth) acrylate (A) having a hydroxyl group and an organic polyisocyanate (B).

[(Meth) acrylic acid ester compound (11)] Reaction product of (meth) acrylate (A) having a hydroxyl group, organic polyisocyanate (B), and trivalent or higher valent polyol and / or diol (D) Is.

The (meth) acrylate (A) having a hydroxyl group, the organic polyisocyanate (B) and the polyol (D) in the above (meth) acrylic acid ester compounds (10) and (11) are urethane prepolymers [I] and [II]. It is the same as the raw material.

The (meth) acrylic acid ester compounds (1) to (1
Among 1), the most preferable compounds as the adhesive of the present invention are as follows.

(1): 2-hydroxyethyl (meth) acrylate (2): trimethylolpropane tri (meth) acrylate (3): 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane (4): Dicyclopentenyl (meth) acrylate (5): Methyl (meth) acrylate (6): 2-Hydroxy-3-phenoxypropyl (meth) acrylate (7): Ethoxycarbonylmethyl (meth) acrylate (8): Acid phospho Oxypropyl (meth) acrylate (9): 3-chloro-2 acid phosphooxypropyl (meth) acrylate (10): 2-hydroxyethyl (meth) acrylate,
Reaction product of bisphenol A ethylene oxide with tolylene diisocyanate modified product (11): Reaction product of two components of (10) and trimethylolpropane <Photopolymerization initiator [IV]> Compounded in the composition in the present invention Specific examples of the photopolymerization initiator [IV] to be carried out include benzyl, benzophenone, Michler's ketone, 2-chlorothioxysanthone,
2,4-diethylthioxysandone, benzoin, benzoin ethyl ether, camphorquinone, benzoin isobutyl ether, benzoin octyl ether, diethoxyacetophenone, benzyl methyl ketal, 1-hydroxycyclohexyl phenyl ketone, diacetyl,
Examples thereof include methylanthraquinone, acetophenone, 2-hydroxy-2-methylprobiophenone, anthraquinone, and 3,3 ', 4,4'-tetra- (tert-butylperoxycarbonyl) benzophenone.

The mixing ratio of each component described above is as follows.

The polycarbonate diol-modified urethane prepolymer [I] and / or [II] is the adhesive composition 10 of the present invention.
It is preferably 5 to 80 parts by weight, more preferably 10 parts by weight.
~ 65 parts by weight.

The (meth) acrylic acid ester compound [III] is preferably 20 to 90 parts by weight in 100 parts by weight of the adhesive composition of the present invention,
It is more preferably 35 to 80 parts by weight.

The photopolymerization initiator [IV] is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the adhesive composition of the present invention.
~ 10 parts by weight.

<Desired Additive Components> In addition to the components described above, various substances may be added to the composition of the present invention for various purposes. For example, an appropriate amount of sensitizer may be added and mixed, and examples of the sensitizer include dimethylaminoethyl methacrylate, n-butylamine, triethylamine, triethyl-n-butylphosphine, and isoamyl 4-dimethylaminobenzoate. Such amines are used, and the addition amount varies depending on the type of the sensitizer and cannot be generally stated. However, as an example, 100 parts by weight of the (meth) acrylic acid ester is used, and in the case of triethylamine, it is 0.1 -4 parts by weight is preferred.

Furthermore, nitro compounds, nitroso compounds, and quinones for the purpose of improving stability, dyes and pigments for the purpose of coloring, thixotropic agents such as silica for the purpose of imparting thixotropic properties, for the purpose of thickening and increasing the amount. Acrylic resin, urethane resin, epoxy resin, silica, etc. can be mixed respectively.

Further, vinyl compounds such as N-vinylpyrrolidone and ethyl vinyl ether may be blended for the purpose of controlling photocurability and resin characteristics.

The adhesive composition according to the present invention can be easily prepared by mixing and dissolving the components described above at room temperature or under heating.

[Curing means]

The adhesive composition according to the present invention is excellent in storage stability because it does not contain an organic peroxide, but it can be used in the same manner as a conventional photocurable adhesive composition and is irradiated with light such as ultraviolet rays. By doing so, polymerization and curing can be easily achieved. And since the composition of the present invention does not contain an organic peroxide as described above, the heat generated by photopolymerization and the heat generated by a light irradiation device cause a radical thermal polymerization and curing reaction by the organic peroxide. Therefore, foaming due to such a radical reaction does not occur.

〔Example〕

Example 1 About 12.7 parts by weight of toluene diisocyanate as an organic polyisocyanate (B) and about 200 ppm of dibutyltin dilaurate were placed in a reactor, and a molecular weight of about 2000 was obtained as a polycarbonate diol (C) while maintaining a reaction temperature at about 70 ° C. About 77.8 parts by weight of polycarbonate diol (manufactured by Toagosei Kagaku Kogyo Co., Ltd .: reaction product of ethylene carbonate and 1,6-hexanediol) is gradually added under stirring to about 1
After reacting with stirring for about 2 hours, about 200 ppm of dibutyltin dilaurate was added, and about 9.5 parts by weight of 2-hydroxyethyl methacrylate as a (meth) acrylate (A) having a hydroxyl group was maintained under stirring and the reaction temperature was 70 ° C. While gradually adding and reacting, the reaction solution was analyzed by infrared absorption spectrum, and the reaction was continued until it was confirmed that the characteristic absorption of the group -NCO (around 2250 cm ^-1 ) disappeared.

As a result, 100 parts by weight of a rubber-like solid polycarbonate diol-modified urethane prepolymer [I] was obtained at room temperature. Further, as a result of analyzing the polycarbonate diol-modified urethane prepolymer [I] by infrared absorption spectrum, the following main peaks were confirmed.

-NHCOO- absorption; 1520 ~ 1550cm ^-1 , 1720 ~ 1740cm ^-1 Example 2 About 13.1 parts by weight of toluene diisocyanate as an organic polyisocyanate (B) and about 200 ppm of dibutyltin dilaurate were placed in a reactor, and a molecular weight of about 2000 was obtained as a polycarbonate diol (C) while maintaining a reaction temperature at about 70 ° C. About 80.3 parts by weight of polycarbonate diol (produced by Toagosei Kagaku Kogyo Co., Ltd .: a reaction product of ethylene carbonate and 1,6-hexanediol) is slowly added with stirring and stirred for about 1 hour to react, and then dilauryl acid is added. About 200 ppm of dibutyltin was added, and about 4.9 parts by weight of 2-hydroxyethyl methacrylate as a (meth) acrylate (A) having a hydroxyl group was gradually added with stirring and while maintaining the reaction temperature at 70 ° C, and the reaction was performed for about 2 hours. Then, about 1.7 parts by weight of trimethylolpropane as the polyol (D) was stirred and the reaction temperature was adjusted to 70 While gradually maintaining the temperature at 0 ° C, the reaction solution was analyzed by infrared absorption spectrum.
The reaction was continued until it was confirmed that the characteristic absorption of the group -NCO (around 2250 cm ^-1 ) disappeared.

As a result, 100 parts by weight of a polycarbonate diol-modified urethane prepolymer [II] which was a rubber-like solid at room temperature was obtained. In addition, as a result of analyzing the polycarbonate diol-modified urethane prepolymer [II] by infrared absorption spectrum, the following main peaks were confirmed.

-NHCOO- absorption; 1520 ~ 1550cm ^-1 , 1720 ~ 1740cm ^-1 Example 3 Using the polycarbonate diol-modified urethane prepolymers [I] and [II] obtained in Examples 1 and 2, photocurable adhesive compositions No. 1 to No. 6 having the compositions shown in Table 1 were prepared. Prepared.

The photo-curing performance is the time until the surface tack disappears when the No. 1 to No. 6 photo-curable adhesive compositions shown in Table 1 are applied on the glass plate in a film thickness of about 50 μm and irradiated with ultraviolet light. Was measured.

In addition, the softness is shown by No. 1 to No. 6 shown in Table 1 on the glass plate.
The photocurable composition of No. 2 was applied in a film thickness of about 5 mm, and ultraviolet light was irradiated for about 30 seconds according to the light irradiation conditions shown below, and its hardness was evaluated with a Shore hardness D type.

Photocuring performance and flexibility are shown in Table 2.

However, PCDUP means a polycarbonate diol-modified urethane prepolymer.

Photo-curing conditions; (UV irradiation equipment used); Ushio Electric Co., Ltd. <System model: UVC-1833 / IN4A-2D
I> (high pressure mercury lamp); semi-assembled light type, lamp output = 80 W / cm (illuminance [365 nm]); 140 mw / cm ² [Effect of the invention] The composition according to the present invention is a photocurable adhesive composition. When used for adhesion of metal parts, hermetic seals, loosening prevention, fixing of fitting parts, etc., it exhibits excellent flexibility as a stress relaxation cured product. The photocurable adhesive composition is excellent in that the speed of the curing step can also be improved, and is significantly improved in reliability of adhesive strength and productivity in comparison with conventional ones.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 63-165420 (JP, A) JP 61-2719 (JP, A) JP 60-11568 (JP, A) JP 60- 13868 (JP, A) JP 60-6773 (JP, A) JP 59-217778 (JP, A) JP-B 6-13692 (JP, B2)

Claims (1)

[Claims] 1. A polycarbonate diol-modified urethane prepolymer having a (meth) acryloyloxy group, which is a reaction product of a (meth) acrylate (A) having a hydroxyl group, an organic polyisocyanate (B), and a polycarbonate diol (C). It is a reaction product of one or more of [I] and / or a (meth) acrylate (A) having a hydroxyl group, an organic polyisocyanate (B), a polycarbonate diol (C), and a polyol (D). One or more of polycarbonate diol-modified urethane prepolymers [II] having a (meth) acryloyloxy group, and () other than the above-mentioned polycarbonate diol-modified urethane prepolymers [I] and [II] having a (meth) acryloyloxy group. (Meth) acrylic acid ester compound [III] One or more of
An adhesive composition comprising a photopolymerization initiator [IV] and containing no organic peroxide