JP3455687B2 - Adhesive composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition containing a specific fluorinated acrylate resin. 2. Description of the Related Art An ultraviolet curable adhesive is mainly composed of an acrylic resin, and therefore has a low glass transition temperature and has a problem in heat resistance. Further, conventional acrylic resins have a large curing shrinkage during curing and a large thermal expansion coefficient of the cured resin, and thus are not suitable for precision fixing of optical components and the like. In recent years, with the development of optical communication, there has been an increasing demand for organic materials suitable for molding optical components such as lenses and prisms, and for bonding and joining optical materials. In addition, when considering compounding with semiconductors such as laser diode light sources and photodiodes as optical communication devices, low-dielectric and insulating organic materials must be used for bonding and bonding with high-frequency electronic circuits. Demands are growing. In particular, an adhesive used for bonding optical materials needs to have a low refractive index in order to match the refractive index of an optical material such as glass. Since high temperatures are also applied to the peripheral members of the part, it is necessary to perform the bonding at a low temperature. Heretofore, epoxy resin-based adhesives have been mainly used as the adhesives used for the above-mentioned applications. However, bisphenol A type epoxy resins usually used for epoxy resin adhesives have a refractive index of 1.51 to 1.58, which is a common quartz material as an optical material. Significantly higher than 1.46. Therefore, there is a problem that the loss due to reflection at the interface between the quartz or the like and the adhesive increases. Also, there is a problem that the return light due to the reflection at the interface makes the operation of the laser diode light source of the optical communication line unstable. When an adhesive is used for bonding and molding of optical components used in an optical communication system, the adhesive strength must be high, but in addition, properties such as heat resistance and water resistance are improved. Need to be done. For that purpose, it is necessary to mix with a high refractive index adhesive composition having excellent heat resistance and water resistance. Therefore, an adhesive composition having a low refractive index close to that of quartz or the like and having high adhesive strength is required. The present invention has been made to solve the above problems, and an object of the present invention is to provide a low refractive index adhesive composition having a small difference in refractive index from an optical material and having excellent adhesive strength. Is to provide. The adhesive composition of the present invention has the following general formula: CH ₂ ＣＨCHCOO—R _f —OOCCH ＝ CH ₂ (I) And a photopolymerization initiator or a curing agent. The adhesive composition of the present invention comprises a compound represented by the following general formula and a photopolymerization initiator as essential components. CH ₂ ＣＨCHCOO—R _f —OOCCH ＝ CH ₂ (I) The compound of the formula (I) (I-1, I-
The mixing ratio of 2) and the photopolymerization initiator is appropriately selected according to the properties required for the adhesive. The compound represented by the above formula (I) is produced as follows. That is, according to the following reaction formula: The solution of compound (A) in isopropyl alcohol (IPA) is concentrated under reduced pressure, benzene is added to the residue, and the mixture is filtered to obtain white crystals of compound (A). Compound (A) 71
8 g, 844 g of triethylamine (TEA), 3.5 g of pyrogallol and 5 l of chloroform.
The mixture is cooled to 10 ° C or lower, and a solution of 600 g of acrylic acid chloride in 2.5 liters of chloroform is added dropwise at -10 ° C or lower. Stir until the next day, then add water, separate the layers, wash with saturated saline, dry over anhydrous magnesium sulfate, and evaporate. The residue (1543 g) is separated by a column (developing solvent: chloroform), and the eluate is washed and filtered with hexane to obtain a compound (I-1) consisting of 514 g of crystals and 1020 g of a candy (filtrate concentrate). The compound represented by the above formula (I) (I-
2) is manufactured as follows. That is, according to the following reaction formula: 1390 g (3.34 mol) of compound (B)
And 4.5 g of hydroquinone monomethyl ether were dissolved in 3750 ml of chloroform, and 1215 g of triethylamine was added while cooling with methanol / dry ice.
(12.0 mol) is added dropwise at 5 ° C. or less. Further, the reaction solution was cooled to -20 ° C or lower, and acrylic acid chloride 1
A solution of 000 g dissolved in 1500 ml of chloroform is added dropwise. After returning to room temperature, water was added to separate the layers,
The extract was washed with saturated aqueous NaCl, dried, filtered through celite, evaporated, and then separated on a silica gel column (developing solvent: chloroform) to give 1488 g of the compound (I-
Obtain 2). In the present invention, various acrylate resins such as an epoxy resin, an epoxy (meth) acrylate resin, a urethane acrylate resin, a butadiene acrylate resin or a modified product thereof may be contained in addition to the above essential components. (Reactivity) It may contain a diluent, a curing catalyst (curing accelerator), a coupling agent and the like. In the present invention, a compound known as a reactive oligomer or prepolymer having at least one carbon-carbon double bond in a molecule is mixed with the acrylate compound represented by the formula (I). It is also possible to use it. Examples of such compounds include (1) ethylenically unsaturated polyesters obtained by condensation oligomerization of a polybasic carboxylic acid with a polyhydric alcohol and an ethylenically unsaturated monocarboxylic acid, and (2) a polyvalent epoxy compound. Compounds obtained by adding an ethylenically unsaturated monocarboxylic acid to (3) ethylenically unsaturated monocarboxylic acid esters of polyether polyol, (4)
Ethylenically unsaturated polyurethanes obtained by adding a hydroxyalkyl ester of an ethylenically unsaturated monocarboxylic acid to a polyvalent isocyanate compound, diallyl phthalate prepolymer, diallyl isophthalate prepolymer, diallyl terephthalate isopolymer and the like can be mentioned. . Specific examples of the ethylenically unsaturated polyesters of the above (1) include oligoester (meth) acrylate obtained by condensation oligomerization with maleic anhydride, propylene glycol, and (meth) acrylic acid. Can be Specific examples of the compound (2) include an epoxy (meth) acrylate obtained by adding (meth) acrylic acid to bisphenol A diglycidyl ether and an epoxy obtained by adding (meth) acrylic acid to hydrogenated bisphenol A epoxide. (Meth) acrylate and the like can be mentioned. Specific examples of the ethylenically unsaturated monocarboxylic acid esters of the polyether polyol (3) include polyethylene glycol di (meth) acrylate and polytetraethylene glycol di (meth) acrylate. . Specific examples of the ethylenically unsaturated polyurethanes of the above (4) include a polyurethane having isocyanate groups at both terminals obtained by reacting an excess of diisocyanate with ethylene glycol, and 2-hydroxyethyl (meth) acrylate. And a urethane (meth) acrylate obtained by reacting the above. The curing agent used in the present invention includes, for example, 2,2'-azobisisobutylnitrile, 2,2 '
-Azobis (2,4-dimethylvaleronitrile), (1
-Phenylethyl) azodiphenylmethane, 2,2'-
Azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobitylate, 2,2'-azobis (2-methylbutylnitrile), 1,1-azobis (1- Cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2'-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-
Azo compounds such as methoxyvaleronitrile and 2,2'-azobis (2-methylpropane); diacyl peroxides such as benzoyl peroxide and p-chlorobenzoyl peroxide; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide. Kind,
Peresters such as tert-butyl perbenzoate and tert-butyl peroxy-2-ethylhexoate; hydroperoxides such as tert-butyl hydroperoxide and cumene hydroperoxide;
Thermal polymerization initiators such as diaryl peroxides such as tert-butyl peroxide, dicumyl peroxide, and di-sec-butyl peroxide are included. As the photopolymerization initiator used in the present invention, for example, 2,2-diethoxyacetophenone, 2,2
2-dimethoxy-2-phenylacetophenone, benzophenone, methyl o-benzoylbenzoate, benzoyl isobutyl ether, 2-chlorothioxanthone, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Examples include a photopolymerization initiator such as methylpropan-1-one. The reactive diluent used in the present invention includes styrene, 1,6-hexanediol di (meth) acrylate, isobornyl (meth) acrylate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, butylene glycol dimethacrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, lauryl acrylate, modified dicyclobentyl acrylate, glycidyl methacrylate, tetrahydrofurfuryl acrylate, 1,
Examples thereof include 3-butylene glycol dimethacrylate, and a compound having a carbon-carbon double bond represented by the following structural formula. Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image In the above equations (1) to (14), Y, Y ¹ ,
Y ² represents a C _{1 to} C ₁₂ alkyl group (provided that Y ¹ and Y ² in formulas (5) and (6) may be the same or different), and R is C _{1 to} C 12 ₁₂ represents an alkyl group, and Q represents any of H, Cl, Br, a C _{1 to} C ₁₂ alkyl group, and a fluoroalkyl group. In the present invention, a coupling agent such as trimethoxysilylpropyl (meth) acrylate can be mixed. Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Example 1 The following formula: The acrylate compound represented by the formula (“HA”
FA ”) and the following formula: An acrylate compound represented by the formula (“FC”
HA), cumene hydroperoxide (abbreviated as “CHPO”) as a thermal curing agent, and 2,2-dimethoxy-2-phenylacetophenone (abbreviated as “BDK”) as a photocuring agent. And the mixture was stirred to obtain a liquid adhesive composition. When cumene hydroperoxide ("CHPO") was used as a curing agent, the composition was cured by applying a temperature of 150 ° C for 3 hours and 2,2-dimethoxy-2-phenylacetophenone (“ In the case of using “DBK”), a cured product was obtained by irradiating 10 mW / cm ² ultraviolet rays for 10 minutes using a high-pressure mercury lamp. However, 1
It was molded and cured into a plate having a thickness of mm. The refractive index (n) of the liquid adhesive composition before curing
_L ) and the refractive index (n _D ²⁰ ) of the obtained cured product were measured with an Abbe refractometer. Table 1 shows the results. However, the refractive indices n _L and n _D ²⁰ indicate values at the room temperature (25 ° C.) at the wavelength of the sodium D line (589.3 nm). The glass transition temperature (Tg) of the obtained plate-like cured product was determined by dynamic viscoelasticity measurement. Table 1 shows the obtained results. Next, the shape as shown in FIGS.
A BK7 glass plate of a size was used, which
After applying the liquid adhesive composition as shown in (1), the composition was cured to prepare an adhesive test piece. However, the curing conditions were the same as for the preparation of the plate-like cured product. Here, FIG. 1 is a cross-sectional view showing a state in which two pieces of adhesive test pieces are shifted and partially overlapped and bonded, and FIG. A plan view of the test piece viewed from above is shown. Adhered as in FIG. 1 and FIG. 2, thickness 5 mm, length 30
mm, an adhesive test piece having a width of 20 mm, a temperature of 25 mm.
When the tensile shear adhesive strength was measured at a temperature of 5 ° C. and a tensile speed of 5 mm / min, the BK glass of the adherend was broken at 100 kgf / cm ² or more. From the results in Table 1, it was found that the obtained adhesive test piece exhibited good adhesiveness and a low refractive index. Further, the obtained adhesive test piece had a high glass transition temperature, and thus was excellent in heat resistance. [Table 1] Example 2 The liquid adhesive composition obtained in the same manner as in Example 1 was cured into a disk having a thickness of 1 mm and a diameter of 50 mm. However, as the compound of the formula (I) and the curing agent mixed, the compounds shown in Table 2 were used in the proportions shown in Table 2. The relative permittivity (ε) and dielectric loss tangent (tan δ) at 1 kHz and 1 MHz of the obtained cured product were measured using an LCR meter.
It was determined by a method based on the STM-D150 standard. The volume resistivity was measured using an ASTM-D using a super insulation resistance meter.
257 method. Table 2 summarizes the obtained results. [Table 2] As is clear from the results in Table 2, the cured adhesive composition of the present invention has a low dielectric constant and a high insulating property.
It was found to be useful as an adhesive and a molding agent for optical components used in optical communication systems in which optical components and electric circuits were mixed. As described above, the adhesive composition of the present invention has a lower refractive index than the conventional adhesive composition, and has a smaller difference from the refractive index of the optical material. The cured adhesive composition has a low dielectric constant and a high insulating property, and also has an excellent adhesive strength. Accordingly, it is useful as an adhesive for optical components and a molding agent for optical components used in an optical communication system in which optical components and electric circuits are mixed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a state in which adhesive test pieces are partially overlapped and bonded. FIG. 2 is a plan view showing a state in which adhesive test pieces are partially overlapped and bonded. [Description of Signs] 1 BK glass plate 2 Adhesive and bonded part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-129146 (JP, A) JP-A-2-160808 (JP, A) JP-A-60-208311 (JP, A) JP-A-61- 63802 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) C09J 4/00-201/10 C08F 2/00-2/50 C08F 20/00-238/00 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claim 1] The following general formula: CH ₂一般 CHCOO-R _f -OOCCH ＝ CH ₂ (I) An adhesive composition comprising: a compound represented by the formula: and a photopolymerization initiator or a curing agent.