JP2000297149A - Active energy ray-induced cationic curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-induced cationic curable compsn. having a large curing speed relative to an active energy ray, having a sufficient curing property, and providing a cured product with excellentheat resistance. SOLUTION: This compsn. comprises the following components (A) and (B): (A) an oxetane-modified novolak rein obtd. by reacting (a) a phenolic novolak resin and (b) an oxetane compd. having a chloromethyl group or a glycidyl group in a molecule; and (B) an active energy ray-induced cationic polymerization initiator. The compsn. preferably comprises a compd. having an epoxy group or an oxetanyl group in addn. to the above-described components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray cation-curable composition, and the composition obtained by the present invention comprises a paint / coating agent, a film / sheet material, a molding material, a material sealing material, It can be suitably used as an adhesive or the like.

[0002]

2. Description of the Related Art Polyfunctional acrylate compounds, which are widely used as active energy ray-radical curable resins, have a variety of types and have the advantage of being able to control physical properties by copolymerization at will. Since the energy ray curing is basically a normal temperature reaction, the curing reaction does not proceed sufficiently, and no satisfactory heat resistance can be obtained. On the other hand, the alicyclic epoxy compound, which is one of the active energy ray cation-curable resins, has a stable growth terminal in the polymerization reaction, so the curing reaction continues even after irradiation with the active energy ray,
It is known that the chemical resistance and heat resistance are improved by leaving the substrate at room temperature for several days after irradiation with active energy rays.
However, the curability of the alicyclic epoxy compound is lower than that of the polyfunctional acrylate, so that the curing rate is low and the performance of the obtained cured product is not stable.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an active energy ray which has a high curing rate with respect to an active energy ray, has sufficient curability, and gives a cured product having excellent heat resistance. It is to provide a cationically curable composition.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that an oxetane-modified phenol novolak resin obtained by reacting with a specific oxetane compound can solve the above problems. The present inventors have found that the present invention has been solved. That is, the present invention is an active energy ray cation-curable composition comprising the following components (A) and (B). (A) Oxetane-modified novolak resin obtained by reacting the following components (a) and (b) (a) Phenol novolak resin (b) Oxetane compound having chloromethyl group or glycidyl group in molecule (B) Active energy ray Cationic polymerization initiator Hereinafter, the present invention will be described in more detail.

[0005]

DETAILED DESCRIPTION OF THE INVENTION (A) Oxetane-modified phenol novolak resin The oxetane-modified phenol novolak resin of the present invention is obtained by reacting (a) a phenol novolak resin and (b) an oxetane compound having a chloromethyl group or a glycidyl group in the molecule. It is obtained by doing. (A) A phenol novolak resin is prepared in the presence of an acid catalyst.
A thermoplastic resin obtained by the addition and condensation of phenols and formalin. Examples of phenols used include unsubstituted or substituted phenol compounds such as phenol, m-cresol, o-cresol, 3,5-xylenol, p-alkylphenol and resorcin, among which phenol, m-cresol and o-Cresol is preferred. On the other hand, (b) oxetane compounds having a chloromethyl group or a glycidyl group in the molecule include those disclosed in JP-A-47-14731 and JP-A-10-204071.
-Chloromethyl-3-alkyloxetane, JP-A-10
3-[(oxiranylmethoxy) methyl] oxetane disclosed in JP-204072A.

The method for producing the oxetane-modified novolak resin will be described using phenol novolak resin and 3-chloromethyl-3-alkyloxetane as examples. The phenol novolak resin is reacted with 3-chloromethyl-3-alkyloxetane for several hours at a reaction temperature of 60 to 100 ° C. in the presence of an alkaline catalyst such as sodium hydroxide or calcium hydroxide to form water and unreacted water. By removing the raw materials, the catalyst, and the like, the desired oxetane-modified novolak resin can be obtained. As the charging ratio of the raw materials in the above reaction, the molar ratio of chloromethyl group in 3-chloromethyl-3-alkyloxetane / phenol group in phenol novolak resin is 1/4 to
It is preferably 10/1, more preferably 1 /
The ratio is from 1 to 5/1, particularly preferably from 1/1 to 2/1. If the chloromethyl group is less than the above range, the curability is inferior, and if it is too large, the raw material cost increases. The ratio of oxetanyl groups in the oxetane-modified novolak resin is 1
It is preferable to adjust the charge ratio of the raw materials so that the number of raw materials is 2 or more per molecule. When the number of oxetanyl groups is less than 2 per molecule, the crosslinking density is low and the heat resistance becomes insufficient.

The amount of the alkaline catalyst used is optimally 0.5 to 1.2 mol per 1 mol of the phenolic hydroxyl group in the phenol novolak resin.

(B) Cationic polymerization initiator with active energy ray The cationic polymerization initiator with active energy ray in the present invention (hereinafter referred to as an initiator) is not particularly limited as long as it is a compound which is cleaved by the action of an active energy ray to release a strong acid. For example, 3.1.5 of UV / EB curing material [CMC Co., Ltd., issued in 1992]
Examples of the compound include those described in items 63 to 65. Among them, diaryliodonium salts and triarylsulfonium salts represented by the compounds represented by the following formulas (1) to (4) are preferable.

[0009]

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[0010]

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[0011]

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[0012]

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In the above formulas (1) to (4), R ¹² represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, R ¹³ represents a hydrogen atom, hydroxy It represents an alkyl group or a hydroxyalkoxy group, and is preferably a hydroxyethoxy group. M represents a metal, preferably, antimony and 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 total amount of the active energy ray cationically curable composition. If the amount of the initiator is less than 0.2 parts by weight, the curability is insufficient, and if it exceeds 10 parts by weight, the flexibility of the cured product is poor.

It is preferable to add a compound having a cationically polymerizable group as a diluent monomer to the curable composition of the present invention for the purpose of reducing viscosity, improving workability, and improving curability. . As these compounds, compounds having an epoxy group, compounds having an oxetanyl group, and vinyl ethers are preferable. Among these, a compound having an epoxy group and a compound having an oxetanyl group are preferable. Examples of the compound having an epoxy group include an alicyclic epoxy compound, an aliphatic epoxy compound, and an aromatic epoxy compound, and among these, an alicyclic epoxy compound having relatively good curability without impairing the heat resistance of the cured product. Compounds and aromatic epoxy compounds are preferred. Examples of alicyclic epoxy compounds include 3,4
And compounds having one or more epoxidized cyclohexyl groups, such as -epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and bis- (3,4-epoxycyclohexyl) adipate. These compounds are commercially available from Union Carbide CYRAC
It is commercially available as URE resin. Examples of the aromatic epoxy compound include glycidyl ether of bisphenol A, glycidyl ether condensate of bisphenol A, and epichlorohydrin-modified novolak resin and cresol resin. The preferable use amount of these epoxy compounds is 10 to 90 parts by weight based on 100 parts by weight of the total amount of the cationically curable composition. If the amount used is less than 10 parts by weight, the liquid viscosity is high and workability is poor, and if it exceeds 90 parts by weight, the heat resistance of the cured product decreases.

The compound having an oxetanyl group includes
JP-A-8-85775 and JP-A-8-13440
5 oxetane compounds, among which compounds having one or two oxetanyl groups in one molecule are preferably used because they are effective in lowering the viscosity of the curable composition. Is done. Examples of the oxetane compound having one oxetanyl group include 3-ethyl-3-[(phenoxy) methyl] oxetane represented by the following formula (5) and 3-ethyl-3- represented by the following formula (6).
(Hexyloxymethyl) oxetane, 3-ethyl-3- (hydroxymethyl) oxetane represented by the following formula (7), and the like. Examples of the oxetane compound having two oxetanyl groups include the following formula (8) 1, represented by
4-bis [(3-ethyl-3-oxetanylmethoxy)
Methyl] benzene, bis {[1
-Ethyl (3-oxetanyl)] methyl} ether and the like.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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The cationically curable active energy ray composition of the present invention may contain, if necessary, a filler, a coupling agent, a flame retardant, a plasticizer, a low-shrinking agent, a lubricant, a surface modifier, a dye. -Additives such as pigments can be blended. Hereinafter, the present invention will be described more specifically with reference to Production Examples and Examples.

[0023]

EXAMPLES In the following examples, all parts of the components are parts by weight. Production Example 1 Production of oxetane-modified novolak resin (1) Phenol novolak resin ｛Phenolite TD-2106 manufactured by Dainippon Ink and Chemicals, Inc., phenolic hydroxyl equivalent 104, number average molecular weight 801｝ 104 g, 3-chloromethyl-3 269.2 g (2 mol) of -ethyloxetane and 6.4 g of tetrabutylammonium bromide as a catalyst were charged into a reaction vessel, and the temperature was raised until the liquid temperature reached 70 ° C while stirring under a nitrogen atmosphere. Then
140.2 g (1.2 mol as KOH) of a 48% by weight KOH aqueous solution 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 in that state. After cooling the reaction solution, 400 g of methylene chloride and 400 g of water were added, and the mixture was stirred and allowed to stand to separate an aqueous phase and an organic phase. After washing the organic phase three times with 200 ml of water,
Methylene chloride was distilled off, and then excess 3-chloromethyl-3-ethyloxetane was distilled off under reduced pressure to obtain 188 g of oxetane-modified novolak resin (1).

Production Example 2 Production of oxetane-modified novolak resin (2) Phenol novolak resin in a 2 L three-necked flask equipped with a reflux condenser, a thermometer, and a stirrer {Phenolite TD- manufactured by Dainippon Ink and Chemicals, Inc. 2106, phenolic hydroxyl equivalent 104-208 g, 3-ethyl-3-[(oxiranylmethoxy) methyl] oxetane 361.6 g,
3.3 g of potassium hydroxide and 500 g of toluene were reacted for 6 hours under reflux of toluene. After the completion of the reaction, the product was washed with water, and toluene was distilled off under reduced pressure to obtain an oxetane-modified novolak resin (2) as a target product.

Examples 1 to 4 and Comparative Examples 1 to 2 Preparation and Curing Test of Cationic Curable Compositions Compositions shown in Table 1 below, diluted with methylene chloride to a concentration of 50% by weight, were thoroughly mixed. A homogeneous solution was obtained. A mold (14 cm × 4 cm) formed from the above composition solution on a propylene film
cm, thickness about 0.5 mm), air-dried for 2 hours, and then a conveyor type ultraviolet irradiation device (lamp height = 10 c) equipped with a 120 W / cm metal halide lamp.
m, conveyor speed = 10 m / min)
Ultraviolet curing was achieved by passing through. Next, the resulting cured film was allowed to stand at room temperature for one day, and then dried under vacuum for 5 hours to remove residual methylene chloride. Some samples are subjected to a heat treatment (the conditions are described in Table 1), the propylene film is peeled off, cut into a width of 0.5 cm and a length of 4.5 cm, and a viscoelastic spectrum (viscoelasticity measuring device DMS6100 manufactured by Seiko Instruments Inc.) is used. Tensile deformation mode (sine wave vibration, frequency 10 Hz) Heating rate 4 ° C /
It was measured in minutes. Transition temperature (E''max and tanδmax)
And the crosslink density calculated from the elastic modulus at tan δmax temperature + 40 ° C are shown in Table 1. As can be seen from Table 1, the cured product obtained from the active energy ray cation-curable composition of the present invention has a high transition temperature and a high crosslink density, and is a general-purpose alicyclic or aromatic epoxy as shown in Comparative Examples 1 and 2. It is clear that the heat resistance is superior to that of the compound.

[0026]

[Table 1]

[0027]

The cationically curable active energy ray composition of the present invention is rapidly cationically cured by active energy rays such as ultraviolet rays, and the resulting cured product has high heat resistance even when cured at room temperature. . Utilizing this feature, it can be applied to a wide range of fields such as paints / coating materials, molding materials, adhesives and electric insulating materials.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 3/10 C09K 3/10 LZ // C08G 8/28 C08G 8/28 Z (72) Inventor Kuriyama Akira 1 1 Funami-cho, Minato-ku, Nagoya-shi, Aichi F-term in Nagoya Research Institute, Inc. (reference) JC02 KA03 NA14 PA17 4J040 EB071 EE051 GA10 HB06 HB43 HD05 JB07 KA13 LA05 LA06 LA08

Claims (2)

[Claims] An active energy ray cation-curable composition comprising the following components (A) and (B). (A) Oxetane-modified novolak resin obtained by reacting the following components (a) and (b) (a) Phenol novolak resin (b) Oxetane compound having chloromethyl group or glycidyl group in molecule (B) Active energy ray Cationic polymerization initiator 2. The active energy ray cation-curable composition according to claim 1, further comprising a compound having an epoxy group or an oxetanyl group in addition to the above components.