JP4802567B2 - UV-curable liquid composition for adhesive and adhesive - Google Patents

Description

  The present invention relates to an ultraviolet curable liquid composition suitable for an adhesive such as a polymer material. Specifically, the present invention relates to an ultraviolet curable liquid composition for adhesives in the fields of optical disks (DVDs, etc.), various building materials, packaging materials, printing materials, display materials, electric / electronic component materials, optical component materials, liquid crystal panels and the like.

  With the development of information communication devices, various display means for these information communication devices have been developed. Examples of such display means include a CRT, a liquid crystal panel, a device that performs projection by projecting light onto a screen, a PDP panel, and the like. In these display means, display performance is improved by combining polymer films, polymer lenses, and the like having various optical characteristics. For example, in order to optically treat the lens surface, a method using a polymer film is known. In this case, the polymer film is bonded to the lens body via an adhesive.

In general, various adhesives can be used for bonding the polymer material. For example, (a) urethane (meth) acrylate having a number average molecular weight of 5,000 to 15,000, (b) a compound selected from acryloylmorpholine, dimethylacrylamide, diethylacrylamide and diisopropylacrylamide, and (c) phenoxypolyethylene It has been reported that a liquid curable adhesive / adhesive composition containing glycol acrylate has excellent adhesion to PVC and PET (see Patent Document 1).
In recent years, the tendency to desire the use of a solvent-free adhesive excellent in environmental protection without using a solvent and an improvement in productivity for the bonding means of a polymer material has increased. Solvent-free adhesives that can be bonded by irradiation with radiation, particularly UV light, are expected as materials that satisfy these requirements.

  When polymer materials having various optical properties are bonded to each other through an adhesive, it is necessary that the adhesive does not change in hue due to heating, exposure to ultraviolet rays, or the like. However, a material that sufficiently satisfies this demand has not been obtained.

  On the other hand, (1) urethane (meth) acrylate, (2) silane compound having mercapto group, (3) photopolymerization initiator, (4) ethylenically unsaturated monomer having amino group, and (5) (meth) acrylate It has been reported that a photocurable liquid composition containing a compound is useful as a coating layer for a copper-coated copper wire used as a tension member of an optical fiber unit (see Patent Document 2).

  Furthermore, Patent Document 3 describes that when a specific phenolic compound is used in a multilayer coating, yellowing due to a fluorescent lamp is improved. However, use as an adhesive is not described.

In recent years, with the development of information technology including computer device technology, computer software technology, communication technology, etc., more information can be transmitted at high speed. Accordingly, a recording medium capable of recording a larger amount of information at a high density is desired, and development thereof is being advanced.
As such a high-density recording medium, a DVD (digital video disk) has been developed as a next-generation general-purpose recording medium. Unlike a conventional CD (compact disc), a DVD is manufactured by bonding two discs, and therefore an adhesive for bonding is necessary.
Attempts have been made to use hot melt adhesives, thermosetting adhesives, anaerobic curing adhesives, and the like as such adhesives.
However, when a hot melt adhesive is used, the thermal stability and weather resistance are not sufficient, and since it softens in a high temperature environment, there is a problem that the adhesive strength is reduced and the bonded disc is peeled off or deformed. is there. Further, since the transparency is not high, it is difficult to use the DVD with a two-layer structure having a semi-transmissive film as a recording film.
In addition, when a thermosetting adhesive is used, there are problems that the base material constituting the disk is deformed due to heat at the time of curing, and that a long time is required for curing.
Furthermore, when an anaerobic adhesive is used, since it takes a long time to cure, there is a problem that productivity is low.
Therefore, in order to solve such various problems, a photo-curing adhesive has been proposed. For example, Patent Documents 4 to 6 disclose ultraviolet curable resin adhesives mainly composed of urethane acrylate.

JP-A-7-310067 JP 2000-198824 A JP 2002-264276 A Japanese Patent Laid-Open No. 61-142545 JP-A-6-89462 JP 2004-139706 A

As described above, various adhesives for bonding polymer materials to each other have been proposed.
However, the compositions of Patent Documents 1 and 2 have problems such as insufficient adhesive strength.
Moreover, the conventional photocurable resins such as Patent Documents 4 and 5 have the following problems. That is, an LED light source having a sharp emission spectrum at 365 nm has a longer life than conventional mercury lamps and metal halide lamps, and has a feature of greatly reducing variations in irradiation intensity, and a DVD using a photocurable adhesive. It is useful for bonding of the component parts. However, a cured film made of a photocurable adhesive after bonding tends to cause poor curing. In addition, a photocurable resin that can sufficiently prevent corrosion due to moisture of a metal vapor deposition film as a DVD recording layer has not been obtained. Furthermore, when the curing rate of the photo-curable adhesive is excessive, the cured film (adhesive layer) is warped, resulting in a problem that an object to be bonded such as a DVD disk is deformed.
Accordingly, an object of the present invention is to provide an adhesive that is not cured poorly when cured with 365 nm light (ultraviolet light), has excellent adhesiveness, has a moderate curing rate, and has little warping of the cured film (adhesive layer). It is providing the ultraviolet curable liquid composition for agents.

  As a result of intensive studies to achieve the above object, the present inventors have used a photopolymerization initiator that uses a predetermined type of monomer at a predetermined blending ratio and has an absorbance at 365 nm of a predetermined value or more. By using it, the curability of the UV curable liquid resin is improved, the adhesiveness when used as an adhesive is improved, the curing speed becomes an appropriate size, and the cured film (adhesive layer) is warped. The present invention has been completed by finding that it can be reduced.

That is, the present invention provides the following [1] to “5”.
[1] For the total amount of the composition,
(A) Trimethylolpropane tri (meth) acrylate, trimethylolpropane EO modified tri (meth) acrylate, trimethylolpropane PO modified tri (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol diacrylate, tetraethylene Glycol di (meth) acrylate, bis ((meth) acryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate , 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, both ends (meth) acrylate of bisphenol A diglycidyl ether Acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanate Di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of hydrogenated bisphenol A, Nu (R) di (meth) acrylate, Di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of bisphenol A and selected from the group consisting of triethylene glycol divinyl ether, compounds having 2 or more polymerizable unsaturated groups 30-98 wt%, and (B) to 365nm of 0.1 wt% solution The photopolymerization initiator has an absorbance (optical path length of 1 cm) of 0.1 to 15% by mass, and the component (A) is composed of two polymerizable unsaturated groups, with the total amount being 100% by mass. A compound containing 50 to 80% by mass of a compound having 10 to 40% by mass of a compound having three polymerizable unsaturated groups, and the total amount of the component (A) is 100% by mass. An ultraviolet curable liquid composition for adhesives, comprising: mass%.
[2] The adhesive according to [1], wherein the compound having three polymerizable unsaturated groups in the component (A) contains 5 to 30% by mass of a methacrylate compound, with the total amount being 100% by mass. UV-curable liquid composition for use.
[3] The compound having a polymerizable unsaturated group contained in the composition, the total amount of which is 100% by mass, and the component (A) is contained in a content of 80% by mass or more [1] or [2] The ultraviolet curable liquid composition for adhesives described in 1.
[4] The ultraviolet curable liquid composition for adhesives according to any one of [1] to [3], wherein the component (A) includes trimethylolpropane EO-modified triacrylate and trimethylolpropane EO-modified trimethacrylate. .
[5] An adhesive comprising the ultraviolet curable liquid composition according to any one of [1] to [4].

When the ultraviolet curable liquid composition of the present invention is used as an adhesive in optical disk components or the like, when it is cured with 365 nm light (ultraviolet rays) emitted from an LED light source, curing failure does not occur and adhesion is improved. In addition to being excellent, it has an advantage that the curing rate is moderate, the warp of the cured film (adhesive layer) is small, and the deformation of an object to be bonded such as an optical disk is small.
The ultraviolet curable liquid composition of the present invention is useful, for example, as an adhesive for bringing a surface of a member made of silver or a silver alloy in a DVD-R into contact with a surface of a member made of polycarbonate.
Moreover, since the ultraviolet curable liquid composition of this invention is a solvent-free, it is preferable from a viewpoint of environmental protection.
Moreover, since the ultraviolet curable liquid composition of this invention has moderate viscosity at the time of use (at the time of application | coating), workability | operativity is favorable.
Furthermore, since the ultraviolet curable liquid composition of the present invention has little hue change even under high-temperature atmosphere or exposure to ultraviolet rays, optical devices other than DVD, various building materials, packaging materials, printing materials, display materials It can be suitably used for electrical and electronic component materials, optical component materials, liquid crystal panels and the like.

The ultraviolet curable liquid composition for adhesives of the present invention comprises (A) trimethylolpropane tri (meth) acrylate, trimethylolpropane EO modified tri (meth) acrylate, trimethylolpropane PO modified tri (meth) acrylate, ethylene glycol Di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, bis ((meth) acryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane, polyethylene glycol di (meth) ) Acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, bisphenol A Glycidyl ether end (meth) acrylic acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate , Tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of bisphenol A, adduct of ethylene oxide or propylene oxide of hydrogenated bisphenol A di (meth) acrylate of a diol is, and selected from the group consisting of triethylene glycol divinyl ether, compounds having 2 or more polymerizable unsaturated groups from 30 to 98 wt% And it is intended to include a photopolymerization initiator 0.1 to 15 wt% or (B) the absorbance at 365nm of 0.1 wt% solution (optical path length 1 cm) of 0.2 or more.
Here, (A) component makes the whole quantity 100 mass%, 50-80 mass% of compounds which have two polymerizable unsaturated groups, and 10-40 mass of compounds which have three polymerizable unsaturated groups. % Is included.
Moreover, (A) component makes the whole quantity 100 mass%, and also contains 1-20 mass% of methacrylate compounds.
Hereinafter, the component (A), the component (B), and other optional components that can be blended as necessary will be described in detail.
[(A) component]
(A) component is trimethylolpropane tri (meth) acrylate, trimethylolpropane EO modified tri (meth) acrylate, trimethylolpropane PO modified tri (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol diacrylate , Tetraethylene glycol di (meth) acrylate, bis ((meth) acryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane, polyethylene glycol di (meth) acrylate, 1,4-butanediol di ( Both ends of (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, bisphenol A diglycidyl ether Acrylic acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) Isocyanurate di (meth) acrylate, di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of bisphenol A, di (meth) of diol which is an adduct of hydrogenated bisphenol A ethylene oxide or propylene oxide It is a compound having two or more polymerizable unsaturated groups selected from the group consisting of acrylate and triethylene glycol divinyl ether .
Here, among the above compounds , “EO” represents ethylene oxide, and “PO” represents propylene oxide.

As the component (A), a compound having 2 to 6 polymerizable unsaturated groups is generally used, but a compound having 2 to 3 polymerizable unsaturated groups is preferably used as a main component.
Specifically, the ratio of the compound having two polymerizable unsaturated groups in the total amount (100% by mass) of the component (A) is 50 to 80% by mass, preferably 50 to 70% by mass.
(A) The ratio of the compound which has three polymerizable unsaturated groups in the whole quantity (100 mass%) of a component is 10-40 mass%, Preferably it is 20-40 mass%.
The ratio of the total amount of the compound having two polymerizable unsaturated groups and the compound having three polymerizable unsaturated groups in the total amount (100% by mass) of the component (A) is preferably 60% by mass or more. More preferably, it is 70% by mass or more, and particularly preferably 80% by mass or more.

The curing rate of the composition of the present invention can be controlled mainly by the components (A) and (B). In order to control the curing rate and suppress the warpage of the cured film, it is preferable that the component (A) contains a methacrylate compound. By blending the methacrylate compound, it is possible to prevent the curing rate from becoming excessive and to reduce the warp of the cured film.
Content of a methacrylate compound is 1-20 mass% in the whole quantity (100 mass%) of (A) component, Preferably it is 1-10 mass%. When the content of the methacrylate compound is too small, the curing rate becomes too high and the cured film is likely to warp. If the content of the methacrylate compound is excessive, the curing rate is too low, so that the surface property may be deteriorated, for example, the curing at the interface with air becomes insufficient and the adhesion surface becomes sticky.

The methacrylate compound preferably has three polymerizable unsaturated groups.
The ratio of the methacrylate compound having three polymerizable unsaturated groups in the total amount (100% by mass) of the compound having three polymerizable unsaturated groups contained in the composition of the present invention is preferably 5 to 30 mass. %, More preferably 5 to 20% by mass.

  Among the compounds that can be used as the component (A), trimethylolpropane EO-modified tri (meth) acrylate, bisphenol A diglycidyl ether end (meth) acrylic acid adduct, tripropylene glycol di (meth) acrylate, etc. preferable.

  Examples of commercially available components (A) include Iupimer UV, SA-1002 (above, manufactured by Mitsubishi Chemical Corporation), Aronix M-215, M-315, M-325, TO-1210 (above, manufactured by Toagosei Co., Ltd.), GX-8345 (Daiichi Kogyo Seiyaku Co., Ltd.), KS-TPGDA, KAYARAD R-115 (Nippon Kayaku Co., Ltd.), Biscote # 360 (Osaka Organic Chemical Co., Ltd.), Light Ester TMP (Kyoeisha Chemical Co., Ltd.) ), NK ester TMPT-9EO (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be used.

  The blending ratio of the component (A) in the total amount (100% by mass) of the composition of the present invention is preferably 30 to 98% by mass, more preferably 50 to 98% by mass, and particularly preferably 70 to 98% by mass. .

  The blending ratio of the component (A) in the total amount (100% by mass) of the compound having a polymerizable unsaturated group contained in the composition of the present invention is preferably 80% by mass or more, more preferably 90% by mass or more, particularly Preferably it is 100 mass%.

[Component (B)]
The component (B) is a photopolymerization initiator having an absorbance (optical path length of 1 cm) at 365 nm of a 0.1% by mass solution of 0.2 or more.

When the absorbance of the component (B) is within the above numerical range, excellent curability can be obtained when an LED light source having a sharp emission spectrum at 365 nm is used.
“Absorbance of 0.1% by weight solution at 365 nm (optical path length: 1 cm)” is obtained by adding (B) to an appropriate organic solvent (for example, toluene, acetonitrile, etc.) that has substantially no absorption with respect to light having a wavelength of 365 nm. ) After the component is dissolved to a concentration of 0.1% by mass to prepare a sample containing the component (B), the sample containing the component (B) and the sample consisting only of the organic solvent are each in the optical path. It is possible to calculate by storing the sample in a measurement cell having a length of 1 cm and measuring the absorbance of these samples with a UV spectrophotometer.
The absorbance is calculated according to the following formula.
Absorbance = log ₁₀ (S ₀ / S ₁ )
Wherein, S ₀ denotes a transmitted light intensity of a cell that contains a sample consisting only of an organic solvent, S ₁ denotes a transmitted light intensity of the cell containing the sample containing the component (B). ]

  Preferable specific examples of component (B) include, for example, (i) 2,4,6-trimethylbenzoyldiphenylphosphine oxide (the above-mentioned absorbance: 0.7), (ii) 2-methyl-1- [4-methylthio Phenyl] -2-morpholinopropan-1-one (absorbance described above: 0.4), (iii) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 (absorbance described above) : 1 or more). These may be used alone or in combination of two or more.

  A commercial item can be used as said 4 types of compounds which are a component (B). Specifically, (i) 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Lucirin TPO (manufactured by BASF); (ii) 2-methyl-1- [4-methylthiophenyl] -2-morpholinopropane -1-one as Irgacure 907 (manufactured by Ciba Specialty Chemicals); and (iii) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 as Irgacure 369 (Ciba Specialty Chemicals). Chemicals, Inc.).

Specific examples of photopolymerization initiators that do not fall under component (B) because the absorbance at 365 nm (optical path length 1 cm) of a 0.1% by weight solution are less than 0.2 include benzyldimethyl ketal, 1-hydroxycyclohexylphenyl Ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the like.
In the present invention, these photopolymerization initiators can also be used in combination.

  The blending ratio of the component (B) in the total amount (100% by mass) of the composition of the present invention is preferably 0.1 to 15% by mass, more preferably 0.3 to 10% by mass. If the blending ratio is in the range of 0.1 to 15% by mass, curing failure does not occur when used as an adhesive, and a cured film having excellent adhesion can be formed.

[Component (C)]
(C) Antioxidant can be mix | blended with the ultraviolet curable liquid composition of this invention in the range which does not impair the effect of this invention. (C) By mix | blending antioxidant, the yellowing of the cured film which consists of a composition of this invention can be suppressed effectively.
As the component (C), a known antioxidant can be used. For example, hindered phenol compounds such as Irganox 1035 (manufactured by Ciba Specialty Chemicals) and sulfur compounds such as mercaptobenzothiazole are preferable.

  The blending ratio of the component (C) in the total amount (100% by mass) of the composition of the present invention is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass.

[Other ingredients]
In the composition of the present invention, a compound having one polymerizable unsaturated group may be blended within a range not impairing the effects of the present invention.
Examples of the compound having one polymerizable unsaturated group include N-vinylpyrrolidone, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, Acryloyl morpholine, vinyl imidazole, vinyl pyridine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl Examples include (meth) acrylate.

The compounding ratio of the compound having one polymerizable unsaturated group in the total amount (100% by mass) of the composition of the present invention is preferably 0 to 20% by mass, more preferably 0 to 10% by mass.
It is.

  Various arbitrary components can also be added to the ultraviolet curable liquid composition of the present invention within a range not impairing the effects of the present invention. For example, urethane (meth) acrylate oligomer other than the component (A), ultraviolet absorber, silane coupling agent, light stabilizer, anti-aging agent, antifoaming agent, leveling agent, antistatic agent, surfactant, storage stability An agent, a thermal polymerization inhibitor, a plasticizer, a wettability improving agent, and the like can be blended as necessary.

The ultraviolet curable liquid composition of the present invention is produced as follows.
The composition of the present invention is charged with a component (A), a component (B) and other components blended as necessary in a reaction vessel equipped with a stirrer, and the liquid temperature is 20 to 20 until a uniform solution is obtained. It is obtained by stirring while maintaining at 60 ° C.

The ultraviolet curable liquid composition of the present invention exhibits particularly excellent curability when cured with light having a wavelength of 365 nm (ultraviolet rays), but in the same manner as in the case of a normal photocurable liquid composition, It can also be cured by irradiation with radiation such as visible light, electron beam (other than wavelength 365 nm).
The adhesive strength of the cured product of the ultraviolet curable liquid composition prepared as described above to a polymer material is, for example, a peel strength of 10 N / m or more in the adhesion between a PET film and a PET film.

The ultraviolet curable liquid composition of the present invention includes plastics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), metals such as gold, aluminum, silver, and silicon, inorganic compounds such as glass, It shows good adhesive strength between materials, and is particularly suitable as an adhesive for optical discs.
The ultraviolet curable liquid composition of the present invention exhibits particularly good curability and adhesiveness when an optical disc (for example, DVD) is bonded using an LED light source having a sharp emission spectrum at 365 nm, It is useful as an adhesive for optical disks (DVD).

  In the bonding of the optical disk using the DVD adhesive of the present invention, for example, the composition of the present invention is filled between adherends so that the thickness of the cured film (adhesive layer) is 10 to 100 μm. Then, it hardens | cures by irradiating 365 nm light (ultraviolet rays) with the said LED light source, and is performed by adhere | attaching adherends firmly.

The ultraviolet curable liquid composition of the present invention is excellent in heat resistance, water resistance, and moldability in addition to excellent adhesiveness. Therefore, in addition to use as an adhesive for DVD, optical properties are required. Used as an adhesive in the fields of molecular films (for example, MS films and PET films), synthetic resin plates, glass, building materials, packaging materials, printing materials, display materials, electrical and electronic component materials, optical component materials, and liquid crystal panels be able to.
For example, the composition of the present invention can be used for laminating an MS film or a PET film on a vinyl chloride sheet.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
[Example 1]
A compound was charged into a reaction vessel equipped with a stirrer at a blending ratio (parts by mass) shown in Table 1, and stirred at a liquid temperature of 50 ° C. until a uniform solution was obtained, whereby an ultraviolet curable liquid composition was obtained.
[Example 2, Comparative Examples 1-2]
A liquid composition was obtained in the same manner as in Example 1 except that each component was blended in the ratio shown in Table 1.

The cure shrinkage and polymerization rate of the obtained liquid composition were evaluated. The evaluation results are shown in Table 1.
The measuring method of cure shrinkage and polymerization rate is as follows.

<Curing shrinkage>
A liquid composition was applied onto a glass substrate and irradiated with light from a metal halide lamp in air at a dose of 1.0 J / cm ² to prepare a cured film having a thickness of 200 μm. The obtained cured film was cut into 5 cm square, and the weight of the film piece was measured with a balance, and the buoyancy was measured from the change in the tension of the yarn when the film piece was hung with water and put in water. The volume was calculated, and the specific gravity of the cured film was obtained from these values. On the other hand, the specific gravity of the liquid composition before light irradiation was measured using a specific gravity bottle. From the specific gravity of the obtained cured film and the specific gravity of the liquid composition before light irradiation, the curing shrinkage was calculated using the following formula.
Curing shrinkage (%) = {1− (specific gravity of liquid composition before light irradiation / specific gravity of cured film)} × 100
Evaluation criteria for curing shrinkage are as follows.
◎: 7.7 (%) or less ○: Over 7.7 (%) to 7.9 (%) or less ×: Over 7.9 (%) Note that the evaluation of curing shrinkage is good. It shows that the warp of the cured film (adhesive layer) made of the composition of the present invention is small, and it is difficult to cause deformation of an object to be bonded such as a DVD.

<Polymerization rate>
A measurement sample in which a liquid composition was applied to a thickness of 10 μm on an aluminum substrate was subjected to FT-IR (Fourier transform infrared spectrophotometer: FTS6000, manufactured by BIO-RAD; UV irradiation device: USHIO SPOT CURE SP-3, Set to USHIO INC.). Under a nitrogen atmosphere, measurement of the infrared absorption spectrum of the resin was started every 45 milliseconds, and then light from a mercury lamp was irradiated through a 365 nm bandpass filter under the condition of an illuminance of 20 mW / cm ² . The absorption intensity of 810 cm ⁻¹ of the acrylic group after the start of light irradiation was measured for 60 seconds from the start of light irradiation. The value of Rp every 45 milliseconds was calculated by the following formula (1), and the maximum value of Rp for 60 seconds was taken as the resin curing rate (polymerization rate).

R _p = [M] ₀ × (A ⁸¹⁰ _t −A ⁸¹⁰ _{t + Δt} ) / Δt (1)

[Wherein [M] ₀ is the concentration (mmol / g) of vinyl group per unit weight of the liquid composition before light irradiation, and A ⁸¹⁰ _t and A ⁸¹⁰ _{t + Δt} are respectively after time t after light irradiation. The absorption intensity is 810 nm after 45 ms, and Δt is 45 ms. ]
In addition, when the polymerization rate is 600 or less, the efficiency of adhesion is lowered, and the curing tends to be poor. On the other hand, when the polymerization rate exceeds 800, the warp of the cured film (adhesive layer) made of the composition of the present invention increases, and deformation of an object to be bonded such as a DVD tends to occur.

Table 1 in _{[M] 0} is a _{[M] 0} in the formula (1). The details of each component are as follows.
[Component (A)]
(1) Tripropylene glycol diacrylate: KS-TPGDA (manufactured by Nippon Kayaku Co., Ltd.)
(2) Bisphenol A diglycidyl ether end-terminal acrylic acid adduct: KAYARAD R-115 (Nippon Kayaku Co., Ltd.)
(3) Trimethylolpropane EO-modified triacrylate: Biscoat # 360 (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
(4) Trimethylolpropane trimethacrylate: light ester TMP (Kyoeisha Chemical Co., Ltd.)
(5) Trimethylolpropane EO-modified trimethacrylate (EO: 9 mol): NK ester TMPT-9EO (manufactured by Shin-Nakamura Chemical Co., Ltd.)
[Component (B)]
(1) Lucirin TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF)
[Component (C)]
(1) Irganox 1035: 2,2′-thiodiethyl-bis- [3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals)
(2) Mercaptobenzothiazole: 2-mercaptobenzothiazole (manufactured by Tokyo Chemical Industry Co., Ltd.)

Claims (5)

For the total amount of the composition,
(A) Trimethylolpropane tri (meth) acrylate, trimethylolpropane EO modified tri (meth) acrylate, trimethylolpropane PO modified tri (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol diacrylate, tetraethylene Glycol di (meth) acrylate, bis ((meth) acryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate , 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, both ends (meth) acrylate of bisphenol A diglycidyl ether Acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanate Di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of hydrogenated bisphenol A, Nu (R) di (meth) acrylate, Di (meth) acrylate of diol which is an adduct of ethylene oxide or propylene oxide of bisphenol A and selected from the group consisting of triethylene glycol divinyl ether, compounds having 2 or more polymerizable unsaturated groups 30-98 wt%, and (B) to 365nm of 0.1 wt% solution Kicking absorbance (optical path length 1 cm) is 0.2 or more photoinitiators 0.1 to 15 wt%
Including
The component (A) includes 50 to 80% by mass of a compound having two polymerizable unsaturated groups and 10 to 40% by mass of a compound having three polymerizable unsaturated groups, with the total amount being 100% by mass. ,And,
Component (A) is an ultraviolet curable liquid composition for adhesives, comprising 1 to 20% by mass of a methacrylate compound, with the total amount being 100% by mass.   The ultraviolet curable adhesive for adhesive according to claim 1, wherein the compound having three polymerizable unsaturated groups in the component (A) contains 5 to 30% by mass of a methacrylate compound, with the total amount being 100% by mass. Liquid composition.   The compound having a polymerizable unsaturated group contained in the composition, the total amount of which is 100% by mass, and the component (A) is contained at a content of 80% by mass or more. UV curable liquid composition.   The said (A) component is a ultraviolet curable liquid composition for adhesive agents of any one of Claims 1-3 containing a trimethylol propane EO modified | denatured triacrylate and a trimethylol propane EO modified | denatured trimethacrylate.   An adhesive comprising the ultraviolet curable liquid composition according to any one of claims 1 to 4.