JP2001040085A - Cation curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cation curable composition having low viscosity, excellent workability and high refractive index and useful for paint, coating material, film or sheet material, molding material, sealing material, adhesive, lens, etc., by including a specific naphthalene derivative and a specific aromatic compound. SOLUTION: The objective resin contains (A) a naphthalene derivative having oxetanyl group and (B) an aromatic compound having epoxy group or an aromatic compound excluding naphthalene having oxetanyl group. The amounts of the components A and B are preferably 20-90 pts.wt. and 5-80 pts.wt., especially 40-90 pts.wt. and 10-60 pts.wt. based on 100 pts.wt. of the composition, respectively. The component A is preferably a 3-alkyl-3-(1-naphthyloxymethyl) oxetane or 3-(1-naphthyloxymethyl)oxetane of formula (R is H or a 1-4C alkyl).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cationically curable composition, which is useful for paints, coatings, films and sheets, molding materials, sealing materials, adhesives, lenses and the like. is there.

[0002]

2. Description of the Related Art As a compound which is cured by an active energy ray such as an ultraviolet ray or an electron beam, a compound having a cationically curable oxetanyl group (hereinafter referred to as an oxetane compound)
It has been known. Oxetane compounds are less susceptible to oxygen inhibition than polyfunctional acrylates, which also cure with active energy rays, and are excellent in thin-film curability, and have characteristics such as toughness, low shrinkage, and low skin irritation of the cured product. ing. Furthermore, since it is excellent in copolymerizability with general-purpose epoxy resins, a cured product having good mechanical strength and adhesiveness can be easily obtained (Japanese Patent Application Laid-Open No. 8-85775,
See JP-A-8-134405). On the other hand, in the field of optical materials such as lens materials, in recent years, resins have been widely used in place of glass, and for example, the ratio of resin for eyeglass lenses has been increased to about 85%. This is due to the features that it is light and hard to break, and that dyeing is easy. In addition, to use as an optical material, high refractive index,
Although characteristics such as light transmittance, high Abbe number and low specific gravity are required, it is particularly important to increase the refractive index of the resin. As a method of increasing the refractive index, the introduction of halogen atoms, sulfur atoms and aromatic rings with large atomic and molecular refraction is effective, but halogen atoms increase the specific gravity of the resin, and sulfur atoms tend to cause odor problems. Is a problem, and
The problem is that the introduction of an aromatic ring increases the viscosity of the formulation. The oxetane compound is extremely promising as an optical material because it has excellent mechanical strength and adhesiveness, as well as high productivity, fine workability and environmental compatibility, but an aromatic ring is introduced to increase the refractive index. As a result, the viscosity increases, and it is extremely difficult to achieve both workability and a high refractive index.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cationically curable composition having a low viscosity, excellent workability, and a high refractive index.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that naphthalene derivatives having an oxetanyl group, aromatic compounds having an epoxy group or aromatic compounds other than naphthalene having an oxetanyl group. The present inventors have found that a cationically curable composition comprising a compound has a low viscosity and a high refractive index, and has completed the present invention. That is, the present invention is a cationically curable composition comprising (A) a naphthalene derivative having an oxetanyl group and (B) an aromatic compound having an epoxy group or an aromatic compound excluding a naphthalene having an oxetanyl group.

[0005]

DETAILED DESCRIPTION OF THE INVENTION (A) Naphthalene Derivative Having Oxetanyl Group Component (A) in the present invention is a naphthalene compound having a cationically polymerizable oxetanyl group in the molecule, and has a high refractive index because of having a naphthyl skeleton. Become. In this naphthyl derivative, the number of oxetanyl groups in one molecule is preferably one or two, and it becomes difficult to produce a compound having three or more oxetanyl groups. Specific examples include 3-methyl-3- (2-naphthyloxymethyl) oxetane, 3-ethyl-3- (2-naphthyloxymethyl) oxetane, and 3-alkyl-3- represented by the following formula (1). (1-naphthyloxymethyl) oxetane and 3- (1-naphthyloxymethyl) oxetane, and 2,7-bis (1-ethyl-3-oxetanylmethoxy) naphthalene, 1,5-bis (1-ethyl-3- Oxetanylmethoxy) naphthalene and 2,3-bis (1
Naphthyl dioxetane such as -ethyl-3-oxetanylmethoxy) naphthalene;

[0006]

Embedded image

(Wherein, R represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms)

Among them, 3-alkyl-3- (1) is liquid at room temperature and is easy to produce.
-Naphthyloxymethyl) oxetane and 3- (1-
Naphthyloxymethyl) oxetane is preferred, and 3-alkyl-3- (1-naphthyloxymethyl) oxetane is particularly preferred. The above 3-alkyl-3- (1-
The method for producing (naphthyloxymethyl) oxetane is not particularly limited. For example, it can be produced by reacting a 3-halomethyloxetane compound with naphthyl alcohol by heating in the presence of a strong base. In addition, 3-
Halomethyloxetane may be produced by the methods disclosed in JP-A-10-204071 and JP-A-10-212282.

(B) An aromatic compound having an epoxy group or an aromatic compound excluding naphthalene having an oxetanyl group: The aromatic compound having an epoxy group and an aromatic compound other than naphthalene having an oxetanyl group in the present invention include glycidyl ether Type polyfunctional epoxy compounds, phenolic epoxy resins and oxetane-modified novolak resins. The glycidyl ether type polyfunctional epoxy compound is obtained by reacting a polyfunctional phenol compound such as bisphenol A, a phenol novolak resin and a cresol novolak resin with epichlorohydrin. Examples of the phenolic epoxy resin include bisphenol A diglycidyl ether, phenol novolak polyglycidyl ether, and cresol novolak polyglycidyl ether. Further, the oxetane-modified novolak resin includes (a) a phenol novolak resin, and (b) a plurality of oxetanyl groups in the molecule obtained by reacting a compound having an oxetane ring and a chloromethyl or glycidyl group in the molecule. Compounds. Examples of the compound (b) having an oxetane ring and a chloromethyl or glycidyl group in the molecule include 3-chloromethyl-3-alkyloxetanes disclosed in JP-A-47-14731 and JP-A-10-204071. , And JP-A-10-
3-[(oxiranylmethoxy) methyl] oxetane disclosed in JP-A-204072. The reaction between the phenol novolak resin and 3-chloromethyl-3-alkyloxetane is carried out at a reaction temperature of 60 to 100 ° C. for several hours in the presence of an alkaline catalyst to remove generated water, unreacted raw materials, catalyst, and the like. The desired oxetane-modified novolak resin is obtained.

Component (A) in the cationically curable composition
The mixing ratio of the component (B) and (A) is preferably 20 to 95 parts by weight and (B) 5 to 80 parts by weight, more preferably 100 parts by weight of the total amount of the cationically curable composition. , (A) 40 to 90 parts by weight and (B) 10
６０60 parts by weight. When the proportion of the component (A) is less than 20 parts by weight, the refractive index of the cured product is low, and when it exceeds 95 parts by weight, the mechanical properties of the cured product are reduced. On the other hand, when the proportion of the component (B) is less than 5 parts by weight, the strength of the cured product is low.

Further, it is desirable that the cationically curable composition contains an active energy ray cationic polymerization initiator. As the active energy ray cationic polymerization initiator,
Any compound that can be cleaved by the action of active energy rays to release a strong acid can be used without particular limitation. For example, a UV / EB curing material [CMC Co., Ltd., 199
2 years], section 3.1.5, pp. 63-65. Among them, the following formula (2)
Diaryliodonium salts and triarylsulfonium salts represented by the compounds represented by formulas (5) to (5) are preferred.

[0012]

Embedded image

[0013]

Embedded image

[0014]

Embedded image

[0015]

Embedded image

In the formulas (2) to (5), R ¹² is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alkyl group having 1 to 1 carbon atoms.
And R ¹³ represents a hydrogen atom, a hydroxyalkyl group or a hydroxyalkoxy group, preferably a hydroxyethoxy group. M represents a metal,
Preferably, it is antimony or phosphorus. X represents a halogen atom, preferably a fluorine atom, and k represents a valence of a metal, for example, 5 in the case of antimony. ｝

The initiator is preferably used in an amount of 0.2 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the cationically curable composition. If the proportion of the initiator is less than 0.2 parts by weight, the photocurability is insufficient,
If the amount exceeds 10 parts by weight, the physical properties of the cured product are reduced.

Further, to the cationically curable composition of the present invention, a compound having a known cationically polymerizable group is added as a diluting monomer for the purpose of reducing viscosity to improve processability and improving curability. can do. As the compound having a cationically polymerizable group, an epoxy compound, an oxetane compound, and vinyl ethers can be suitably used. Among these, epoxy compounds and oxetane compounds are particularly preferred. The amount of the diluent monomer used is preferably 40% by weight or less, more preferably 20% by weight or less, based on the cationic curable composition. If the amount used exceeds 40% by weight, the refractive index of the cured product decreases, which is not preferred. When the cationically curable liquid composition is used as an active energy ray-curable composition, a filler, a coupling agent, a flame retardant, a plasticizer, a low shrinkage agent, a lubricant, It is preferable to add a modifier and additives such as dyes and pigments.

The cationically curable composition of the present invention can be cured with an active energy ray or the like.
A composition in which the obtained cured product has a refractive index of 1.57 or more as measured by an Abbe refractometer at 25 ° C. is particularly preferable as an optical material.

[0020]

EXAMPLES The present invention will be described more specifically with reference to Production Examples, Examples and Comparative Examples. In addition, all the parts of the components in each example mean parts by weight. Production Example 1 Production of naphthyloxetane 1, equipped with a thermometer, a cooler, a stirrer and a dropping funnel
Α-naphthol 1 in a 000 ml three-necked round bottom flask
80.2 g (1.25 mol), 3-chloromethyl-3
-Ethyl oxetane 201.9 g (1.50 mol) and tetrabutylammonium bromide as catalyst.
4 g was added and heated and stirred at 40 ° C. To this, 175.3 g of a 48% by weight aqueous potassium hydroxide solution (1.50 mo)
l) was added dropwise from the dropping funnel over 30 minutes. After completion of the dropwise addition, the temperature was raised to reflux (about 120 ° C.), and the reaction was continued under reflux for 8 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, 300 ml of pure water was added, and the mixture was stirred well, and then allowed to stand to separate an organic phase and an aqueous phase. 300 ml of toluene was added to the organic phase, and the organic phase was washed three times with 250 ml of water.
Next, the obtained organic liquid was distilled under reduced pressure to distill off toluene as a solvent and 3-chloromethyl-3-ethyloxetane as a raw material. Subsequently, 150 to 15 was obtained by distillation under reduced pressure.
The light yellow liquid distilled under the condition of 2 ° C. (2 mmHg) is 2
13.5 g were obtained. As a result of GC analysis, the purity of the obtained compound was 99%, and the isolation yield was 70 mol%.
Further, the measurement result of ¹ H-NMR (deuterated acetone) is δ (pp
m); 0.95 to 1.00 (t, 3H, CH3-CH2), 1.92 to 2.02 (q, 2H, CH3-
CH2), 4.28 (s, 2H, -OCH2-), 4.45 to 4.49 ｛d, 2H, -OCH2-
(Oxetane ring)｝, 4.60-4.64 ｛d, 2H, -OCH2- (oxetane ring)｝, 6.98-7.02 (d, 1H, aromatic ring), 7.40-7.52 (m, 4H,
Aromatic ring), 7.83 to 7.87 (d, 1H, aromatic ring), 8.25 to 8.29 (d, 1H,
An aromatic ring), and the obtained compound is 3-ethyl-3-
(1-Naphthyloxymethyl) oxetane was confirmed.

Production Example 2 Production of oxetane-modified novolak resin Phenol novolak resin {Phenolite TD-2106 manufactured by Dainippon Ink and Chemicals, Inc .; phenolic hydroxyl equivalent 104; number average molecular weight 801 104 g;
269.2 g of chloromethyl-3-ethyloxetane (2
Mol) and 6.4 g of tetrabutylammonium bromide as a catalyst were charged into a reaction vessel, and the temperature was raised to 70 ° C. while stirring under a nitrogen atmosphere. Then
140.2 g of a 48% by weight aqueous KOH solution (KOH;
2 mol) was added over 30 minutes, and after completion of the addition, the temperature of the reaction solution was raised until the solution was refluxed, and the reaction was performed for 8 hours. After cooling the reaction solution, 400 g of methylene chloride and 400 g of water
Was added, and the mixture was stirred and allowed to stand, and an aqueous phase and an organic phase were separated. After washing the organic phase three times with 300 ml of water, the methylene chloride is distilled off and then the excess of 3-chloromethyl-3-
When ethyl oxetane was distilled off under reduced pressure, 185 g of an oxetane-modified novolak resin in which almost all of the phenolic hydroxyl groups had reacted with oxetane was obtained.

Examples 1 to 8 and Comparative Examples 1 to 2 Preparation of Cationic Curable Composition and Evaluation of Cured Product Using naphthyl oxetane synthesized in Production Example 1, a composition having the composition shown in Table 1 was blended and homogeneously prepared. A liquid was obtained. Conveyor type ultraviolet irradiation device (lamp height = 10 cm, conveyor speed) in which the compounding solution is poured into a mold (14 cm x 4 cm, thickness of about 0.2 mm) formed on a propylene film and a 120 W / cm metal halide lamp is installed. = 10m / min)
And cured in 6 passes. After the cured film was allowed to stand at room temperature for one day, the cured product was peeled off from the propylene film and the physical properties were examined. Measured viscoelastic spectrum @ Viscoelasticity measuring device DMS6 manufactured by Seiko Instruments Inc.
100 Tensile deformation mode (sine wave vibration, frequency 10H
z, the temperature rising rate was 4 ° C./min)｝, the transition temperature (tan δmax) was determined, the crosslinking density was calculated from the elastic modulus at the transition temperature + 40 ° C., and the refractive index was measured at 25 ° C. using an Abbe refractometer. The results are shown in Table 1.

[0023]

[Table 1]

The abbreviations in Table 1 indicate the following compounds.・ YD-128: Bisphenol A type epoxy resin manufactured by Toto Kasei Co., Ltd. ・ YDPN-638: Phenol novolak type epoxy resin manufactured by Toto Kasei Co., Ltd. ・ YD-701: Cresol novolak type epoxy resin manufactured by Toto Kasei Co., Ltd. ・ XDO : Xylylene dioxetane ・ Naphthyl dioxetane: 2,7-bis (1-ethyl-
3-oxetanylmethoxy) naphthalene UVI-6990: Photoinitiator manufactured by Union Carbide Triallylsulfonium hexafluorophosphate salt 50% pure

[0025]

The cationically curable composition of the present invention is a liquid having a low viscosity at room temperature, so that it is excellent in workability and workability, and a cured product obtained by curing the composition has a high refractive index of about 1.6. The cationic curable composition of the present invention can be applied to a wide range of fields including optical materials by utilizing these features because it has a specific gravity and a relatively low specific gravity.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J005 AA07 BB02 4J036 AD08 AF06 AF08 DB30 GA03 HA02 JA01 JA06 JA07

Claims (2)

[Claims] 1. A cationically curable composition comprising (A) a naphthalene derivative having an oxetanyl group and (B) an aromatic compound having an epoxy group or an aromatic compound excluding a naphthalene having an oxetanyl group. 2. The (A) naphthalene derivative having an oxetanyl group is a 3-alkyl-3 represented by the following formula (1):
-(1-naphthyloxymethyl) oxetane or 3-
The cationically curable composition according to claim 1, which is (1-naphthyloxymethyl) oxetane. Embedded image (Wherein, R represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms)