JPH07109333A - Photosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain a photosetting resin composition excellent in dark cure characteristics and useful for coating, etc., by blending a bisphenolic epoxy resin with a hydroxyl group-containing organic compound, a specific amount of an alkoxysilane and a photopolymerization initiator. CONSTITUTION:This photosetting resin composition is obtained by blending (A) a bisphenolic type epoxy resin with (B) preferably 0.1-200 pts.wt. (based on 100 pts.wt. of the component A) of a hydroxyl group-containing organic compound such as polyether polyol, (C) 0.1-10 pts.wt. (based on 100 pts.wt. of total amount of components A and B) of an alkoxysilane of the formula (R<5> to R<8> are alkyl, (e), (f) and (g) are 0 or 1) such as methyltrimethoxysilane and (D) preferably 1-5 pts.wt. (based on 100 pts.wt. of total amount of the components A and B) of a photopolymerization initiator such as a triarylsulfonium salt.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photocurable resin composition.

[0002]

2. Description of the Related Art UV curable resins are paints,
It is often used for adhesives and sealants, and the industries that use it are expanding to electrical machinery, electronics, machinery, automobiles, civil engineering, and so on. However, the biggest drawback of the UV curable resin is that the areas where the light does not reach and the areas not irradiated with light do not cure.
For this reason, ordinary UV-curable resins have many merits, but cannot be applied to opaque parts and parts with shadows. Since many actual parts have such a part, the application is limited to a wide range.
Therefore, in order to cure the non-irradiated area, so-called dual curable means have been studied, and heat-curable property, anaerobic curable property, primer-curable property, moisture-curable property, 2 liquid Addition of curability is being studied.
However, each of these conventional techniques has merits and demerits, and a method having a sufficient effect has not been developed yet. Further, any of the above-mentioned conventional techniques is intended for a radical polymerization type acrylic resin, and is not applicable to a cationic polymerization type resin.

On the other hand, in the photo-cationic polymerizable resin, a phenomenon known as dark cure in which the reaction proceeds even if the light irradiation is stopped is well known. The photocurable epoxy resin composition in which a very small amount of a hydroxyl group-containing organic compound such as Lewis base or polyether polyol is added to the epoxy resin has a slow reaction rate. Potting of parts with parts is under consideration (for example, Japanese Patent Laid-Open No. 63-24).
8825, J. Rad. Curing / Radi
ation Curing, Spring 1991
29-35). However, what has been examined in these is a method of applying a resin composition thinly on a base material, irradiating it with ultraviolet rays, and then adhering another base material thereto, which is not a practical method. On the other hand, using this dark cure, we propose a device that simultaneously irradiates ultraviolet rays while ejecting curable resin, casts it into the filling object as a liquid, and cures it as it is, simultaneously applying resin and irradiating ultraviolet rays. There is also (special fair 4
No. 26333). Therefore, the inventors of the present invention performed ultraviolet irradiation with a photocurable epoxy resin containing a small amount of Lewis base or polyether polyol in a device that radiates ultraviolet rays while ejecting a photocurable resin, The curable epoxy resin hardens in the light irradiation area and the resin cannot be ejected. On the other hand, if the ejection speed is increased, the irradiated photocurable resin can be ejected without being cured in the irradiation area. We have found that the resin does not cure at all, or even gels but does not cure completely. That is, in the case of using a conventionally known dark cure type epoxy resin composition using the above-mentioned device, the curing speed is changed by the change of the discharge speed, the degree of light irradiation, and the compounding ratio of the photocurable resin composition. It has been found that the influence is great and it is difficult to control this.

An object of the present invention is to solve the above problems. Particularly, when an ultraviolet ray irradiation is carried out while ejecting an epoxy resin composition suitable for curing by the above-mentioned method, gelation occurs in the irradiated part. Another object of the present invention is to provide an improved epoxy resin composition which does not cure and gels and cures as it is after a while.

[0005]

The present invention relates to a photocurable resin composition comprising a bisphenol type epoxy resin and a hydroxyl group-containing organic compound and a photopolymerization initiator, wherein an alkoxysilane is further added to the epoxy resin and the hydroxyl group. 0.1 to 1 to 100 parts by weight of contained organic compound
It is characterized by containing 0 parts by weight.

The bisphenol type epoxy resin used in the present invention is preferably glycidyl ether obtained by reacting bisphenol A, bisphenol F, or its alkylene oxide adduct with epichlorohydrin. Various types of epoxy with different epoxy equivalents are commercially available and easily available. It is also possible to add an alicyclic epoxy resin, a novolac type epoxy resin or the like to these epoxy resins for use.

As the hydroxyl group-containing organic compound used as the second component in the present invention, an appropriate compound known as a reaction retarder for cationic polymerization can be used. Alcohols such as methanol and isopropyl alcohol can be used as a matter of course, but this type of lower alcohol is liable to volatilize, which makes it difficult to handle. Normal,
A non-volatile and compatible hydroxyl group-containing organic compound is used, and polyetherpolyol known as a urethane raw material is particularly preferred because it is easily available and imparts flexibility to the cured product. The amount of the hydroxy group-containing organic compound added is usually 0.1 to 2 with respect to 100 parts by weight of the epoxy resin.
It is appropriately selected within the range of 00 parts by weight. If it is too large, the cured product becomes too soft or does not cure, which is not preferable, and if it is too small, the effect as a reaction retarder decreases, and when the resin is discharged while irradiating with ultraviolet rays, the resin cures in the mixer. I will end up.

As the photopolymerization initiator used in the present invention, a group of double salts which are conventionally known photocationic polymerization initiators and are onium salts which release a Lewis acid capable of initiating polymerization upon irradiation are appropriately used. A typical example is the general formula

[0009]

[Chemical 1]

It is a compound represented by:

In the formula, the cation is onium and Z is N≡.
N, S, Sc, Tc, P, As, Sb, Bi, O, halogen (for example, I, Br, Cl), and R ¹ , R ² , R
³ , R ⁴ are organic groups which may be the same or different. a, b, c, d are each an integer of 0 to 3 and
+ B + c + d is equal to the valence of Z. M is a metal or metalloid which is the central atom of the halide complex (metallo)
id) and B, P, As, Sb, Fe, Sn, B
i, Al, Ca, In, Ti, Zn, So, V, Cr,
Examples include Mn and Co. X is halogen, m is the net charge of the halide complex ion, and n is the number of halogen atoms in the halide complex ion.

These can be decomposed under irradiation of ultraviolet rays to cause polymerization or crosslinking of the epoxy resin, but usually a triarylsulfonium salt or a diaryliodonium salt is preferably used. The former is a general formula

[0013]

[Chemical 2]

Is a compound represented by In the formula, M is Sb,
P, As, and the like, and n is an integer that can change depending on M. For example, when M is Sb and X is F, n is 6. The latter is a general formula

[0015]

[Chemical 3]

Is a compound represented by: Where M, X, n
Is the same as above.

The addition amount of these photopolymerization initiators is usually 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight per 100 parts by weight of the total of the epoxy resin and the hydroxyl group-containing organic compound.
Parts by weight. If it is too small, the resin will not cure, and if it is too large, it becomes uneconomical.

The present invention is characterized in that an alkoxysilane is further added to the composition containing the above-mentioned components as essential components. Alkoxysilanes are usually of the general formula

[0019]

[Chemical 4]

Can be represented by In the formula, R ⁵ , R ⁶ , and R
⁷ are the same or different alkyl groups, e, f, g
Is an integer of 0 or 1. These alkoxysilanes are commercially available as silane coupling agents and are easily available. As a specific example, methyltrimethoxysilane,
Examples thereof include propyltrimethoxysilane, γ-methacryloxypropyl, trialkoxysilane, γ-glycidoxypropyl and trialkoxysilane.

These alkoxysilanes have the functions of adjusting the pot life of the photocurable composition of the present invention after irradiation with light, delaying the curing start time appropriately, and improving the physical properties of the cured product.

The amount of alkoxysilane added is 0.1 to 10 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the total of the epoxy resin and the hydroxyl group-containing organic compound. If the amount is less than 0.1 parts by weight, the effect of delaying the curing start time is not exerted, and if the amount is more than 10 parts by weight, the effect commensurate with the addition is not improved and it is uneconomical.

[0023]

EXAMPLES Using the irradiation apparatus shown in FIG. 1, ultraviolet rays were irradiated from the side of the mixer while flowing a liquid resin (composition) 2 into a transparent disposable mixer 1 made of polypropylene for mixing two liquids. Ultraviolet irradiation is performed from the 200 W spot type irradiator 3 using the three-branch optical fiber 4.
The distance from the direction was 20 mm. The resin was evaluated by irradiating the resin with ultraviolet rays using the above apparatus and discharging the resin into a measuring cup for 30 seconds. The amount of the resin was measured and used as the resin discharging speed. The time when the entire resin gelled was measured starting from the time when the resin was started to be discharged, and the hardness of the cured product after standing for one day at room temperature was measured. In this experiment, the discharge speed of the resin corresponds to a normal ultraviolet irradiation amount, and when the discharge speed is 0 mg / s, the curing is the same as the normal method.

<< Experiment 1 >> The cationic UV-curable resin used was a bifunctional resin having a molecular weight of 800 for polyurethane as a reaction retarder in 90 parts by weight of a bisphenol A type epoxy resin (Ep828 manufactured by Yuka Shell). 10 parts by weight of polyether all (BPX55 manufactured by Asahi Denka Co., Ltd.),
Using 1 part by weight of a triarylsulfonium salt (UVI6970 manufactured by Union Carbite) as an initiator,
As alkoxysilane, 1 part by weight of γ-glycidoxypropyltrialkoxysilane (KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.) was added. The results are shown in Figure 2.

In FIG. 2, when the discharge rate was 40 mg / s, the resin gelled immediately after being discharged, and the resin hardness after standing at room temperature for one day was 87 (Shore-D), which was the same as when the resin was cured by the usual method. there were. Similarly, when discharged at 100 mg / s, the resin gels after about 15 minutes and the hardness after one day is 8
7 (Shore-D). When the discharge speed is further increased (the irradiation dose is decreased), the gelation time of the resin becomes longer, and when the discharge speed exceeds 150 mg / s, the resin is not completely cured. On the contrary, the discharge speed is 40 mg / s
In the following cases, the resin will be hardened in the mixer and will not be discharged. Therefore, a discharge rate of 40 to 150 mg / s is a usable condition for this resin and device.

<< Experiment 2 >> γ-methacryloxypropyltrimethoxysilane was used as an alkoxysilane (K, manufactured by Shin-Etsu Chemical Co., Ltd.
The experiment was performed under the same conditions as in Experiment 1 except that BM503) was changed. The results are shown in Fig. 3.

In FIG. 3, as in Experiment 1, when the discharge rate was 40 mg / s, the resin gelled immediately after being discharged, and the resin hardness after standing at room temperature for one day was the same as when it was cured by the usual method. (Shore D). Similarly 100
When discharged at mg / s, the resin gelled after about 20 minutes and the hardness after one day was 87 (Shore D). When the discharge speed is further increased (the irradiation dose is decreased), the gelation time of the resin becomes longer, and when the discharge speed exceeds 100 mg / s, the resin is not completely cured. On the other hand, if the discharge rate is 40 mg / s or less, the resin will be hardened in the mixer and will not be discharged. Therefore, with this resin, a discharge rate of 40 to 100 mg / s is a usable condition.

[0028]

[Comparative Example] An experiment was conducted under the same conditions as in Experiment 1 except that alkoxysilane was not used. The results are shown in Fig. 4.

Similarly in FIG. 4, the discharge rate is 0 mg / s.
Corresponds to an ordinary irradiation method, and the hardness of the cured product was 85 (Shore-D). At a discharge rate of 43 mg / s, the hardness was cured to 85 (Shore-D) immediately after the discharge. Discharge rate 80 mg
At / s, the resin did not cure after ejection and remained gelled. It can be seen that there is almost no usable range.

[0030]

As can be seen from the above examples, the photocurable resin composition of the present invention can control the curing rate after irradiation with ultraviolet rays. For example, the photocurable resin composition can be photocured while being irradiated with light using a coating device. It is extremely easy to use when applying or filling the resin. Also, the physical properties of the cured product are improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an irradiation device used in Examples.

FIG. 2 is a graph showing the results of Experiment 1.

FIG. 3 is a graph showing the results of experiment 2.

FIG. 4 is a graph showing the results of a comparative example.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/032 501 501/07/07501

Claims (1)

[Claims] 1. A photocurable resin composition comprising a bisphenol type epoxy resin and a hydroxyl group-containing organic compound and a photopolymerization initiator, wherein an alkoxysilane is further added to the epoxy resin and the hydroxyl group-containing organic compound 1.
A photocurable resin composition, characterized by being mixed in an amount of 0.1 to 10 parts by weight with respect to 00 parts by weight.