JPS5889608A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain titled resin composition of transparency, with little change in its own characteristics with time, also having outstanding adherence, comprising, free from any initiator a specific thermoplastic resin and a polymerizable, acrylic group-contg. polymer. CONSTITUTION:The objective composition comprising (A) 100 parts by wt. of an organic solvent soluble-type acrylic thermoplastic resin (e.g., methyl methacrylate polymer) and (B) 500 parts by wt. of a polymerizable unsaturated acrylic group-contg. polymer (e.g., an acrylate ester oligomer). If required, a polymerization accelerator (e.g., hexamethylene diacrylate) is further incorporated. USE:For photo-curable lens adhesives, metal protective coat, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to curable resin compositions, particularly those referred to as photocurable resin compositions.

Photocurable resin composition is a general name for a type of functional polymer that increases its molecular weight through the reaction of acrylic groups incorporated in the resin composition by absorbing light energy. .

The composition of the photocurable resin composition is a resin composition whose basic component is what is called oligo i- or polymer, which has a polymerizable acrylic group as one molecular constituent factor.

ζ Due to its curing mechanism, the resin composition used as the basic component requires activation of the polymerizable acrylic group by absorption of light as the first condition for reaction. In order to make industrial use of this resin, there is a finite amount of time.
Preferably, the polymerizable acrylic group should sufficiently react to increase the molecular weight in as short a time as possible. Taking this point into consideration, the resin composition itself has poor light absorption efficiency and the reaction rate of the polymerizable acrylic group is extremely slow, making it difficult to exhibit sufficient properties within the finite time that can be used industrially. possible, but cannot be put to practical use. Therefore, in reality, a photocurable resin composition does not include a certain kind of substance in addition to a polymer containing a polymerizable acrylic group; in this sense, a photocurable resin composition is a polymer containing a polymerizable acrylic group. will be called the basic component. However, there are certain substances that increase the reaction rate of polymerizable acrylic groups and can be used industrially to increase the molecular weight. It will include things that are difficult to live with. - A polymerization initiator has the effect of increasing light absorption efficiency and increasing the utilization efficiency of light energy from a light source for polymerization. Its basic function is that the polymerization initiator absorbs light in a longer wavelength range than the wavelength of light that can activate the polymerizable acrylic group, and propagates that light energy to the polymerizable acrylic group. The purpose is to activate the group. This function of the polymerization initiator makes it possible to efficiently utilize the light energy of the light source for polymerization, increasing the reaction rate of the polymerizable acrylic group and increasing the molecular weight within the finite time that can be used industrially. can be achieved with.

Examples of the curing accelerator include those containing a polymerizable acrylic group in its structure and simply referred to as reactive monomers in terms of molecular weight. The function of the curing accelerator is to promote the reaction between polymers containing polymerizable acrylic groups, and to adjust the curing rate and properties, or to adjust the viscosity of the photocurable resin composition. What purpose is it used for?

In this way, a conventional photocurable resin composition is composed of (1) a polymer containing a polymerizable acrylic group, (2) a polymerization initiator, and (3) a polymerization accelerator. Note that the polymerization accelerator is not always contained.

Now, also in the photopolymerizable resin composition, the polymerization rate of the polymerizable acrylic group follows the generally accepted law of polymerization rate, that is, it is proportional to the concentration of the reactive component. Considering this point, the reaction of the polymerizable acrylic group progresses, and as the concentration becomes dilute, the reaction rate naturally decreases. It becomes completely impossible for the acrylic groups to be reacted. Therefore, under curing conditions, a certain amount of polymerizable acrylic groups must remain in the photocurable resin composition, which leads to various problems in terms of properties. In addition, various problems arise due to the characteristics of the polymer containing a polymerizable acrylic group and the inclusion of a polymerization initiator. If kept in captivity, the properties tend to change over time due to residual polymerizable acrylic groups. Even in the presence of a polymeric initiator, the reaction of the polymerizable acrylic group will proceed further on a time scale under practical conditions. This can cause various problems such as things becoming brittle, cracked seams having poor light resistance, and other problems such as poor surface contact and easy peeling.

Furthermore, in some cases, the addition of a polymerization initiator may cause the polymerization initiator to be colored, which may limit its use.

The main purpose is to

The curable resin composition according to the present invention is characterized in that it contains a polymer having a polymerizable unsaturated acrylic group and an organic agent-soluble acrylic thermoplastic resin, and does not contain a polymerization initiator. be.

As is already clear, the feature of the present invention is that the reaction of the polymerizable acrylic group proceeds without saturating the polymerization initiator. Therefore, in the curable resin composition according to the present invention, no reaction of the polymerizable acrylic group due to absorption of light by the polymerization initiator is observed on a time scale under practical conditions, so that the properties of the cured resin material change significantly over time. It can be seen that it is easy to use because it is stable and has little oxidation, and it is also easy to design a photocurable resin composition. In addition, since no polymerization initiator is added, the cured resin product is nearly colorless, making it extremely easy to use in various fields. In other words, it is ideal for transparent coating, or in the case of coloring, the color of the coloring agent will develop as it is.

Another feature is that excellent adhesion to metals, glass, etc. can be easily obtained. Taking advantage of this feature, it is also suitable for photocurable lens adhesives, vapor-deposited metal coatings, metal exterior coatings, metal insulation coatings, etc. In addition, various other properties can be obtained, such as water resistance, moisture resistance, and high electrical resistance.

As described above, the curable resin composition of the present invention does not require a polymerization initiator for curing, so it has excellent storage stability, and the properties of the cured resin have very little change over time (IS), and the stability of various properties and properties. It is possible to improve the properties and add new characteristics.

Polymers having polymerizable acrylic groups include various oligomers and poly! − is the general name of acrylates,
Specifically, it refers to acrylate ester oligomer, acrylate polyester, acrylate epoxy oligomer, acrylate polyepoxy, acrylate urethane oligo 1-acrylate polyurethane, and the like.

Suitable organic solvent-soluble acrylic thermoplastic resins include metamethyl acrylate, methyl acrylate,
Acrylates such as butyl acrylate or their derivatives! - or an acrylate monomer such as ethylene, butylene or
It is a copolymer with olefin monomers such as derivatives.

There is no limit to the percentage as long as the molecular weight is several thousand or more, and the constituent monomer components and molecular weight are selected according to the desired properties. Furthermore, if necessary, the addition of polymerization accelerators called additives due to their reactivity, such as hexamethylene diacrylate and trimethylolpropane triacrylate, may also affect the properties. A polymer made of acrylic monomer as a thermoplastic resin (trade name: Niacrybase CMZ-2).

A curable resin composition (1) consisting of 100 parts by weight (manufactured by Genkasei Co., Ltd.) and 500 parts by weight of a polymer containing a polymerizable acrylic group (trade name: Aroex M-8060 manufactured by Toagosei Co., Ltd.);
For comparison, the reaction rate and stability under sunlight of a thermoplastic resin were measured. These results are shown in Figures 1 and f12.

Figure 1 is a graph showing the reaction rate of acrylic groups in the curable resin compositions (■) and (to) by irradiating them with a high-pressure mercury lamp against the irradiation time. be. The song Ml is made of curable resin composition (summer), and the curve ■
is that of curable resin composition 1).

It is clear from FIG. 1 that the curable resin composition according to the present invention exhibits the reactivity of the polymerizable acrylic group even without containing a polymerization initiator), and the reaction rate is sufficiently high for industrial use. It can be seen that it is within a finite amount of time.

FIG. 2 is a graph showing the stability under sunlight, and is for the direct MItj curable resin composition (1).
Direct MII is for curable resin composition 0).

Therefore, when a polymerization initiator was used, no reaction of the crylic groups was observed, indicating that the polymer was stable.

A comparison of some other properties is shown in the table below.

(2) In the following experiments, a curable resin composition with good stability of properties was obtained as in the case of fruit feeding.

Fruit & Hook 2 Thermoplastic acrylic resin Polymer containing a polymerizable acrylic group (manufactured by Dainichiseika, trade name: MUVC-m-4) 100
1 Example 3 Island flexible acrylic resin (manufactured by Dainippon Ink, product name: Iridicum-808
) 30 parts by weight polymer containing polymerizable acrylic group (manufactured by Toagosei, trade name: Aroex M-8030) 1
00 parts by weight Working cylinder 4゜Thermoplastic acrylic resin (manufactured by Genkasei Co., Ltd., trade name Niakurybase CMZ-41)
Polymer containing 25 parts by weight of polymerizable acrylic group (manufactured by Dainippon Ink, trade name: Condic V-5502)
) 1001 parts

[Brief explanation of the drawing]

FIG. 1 is a graph showing the reaction rate of acrylic groups in a curable resin composition. It is a graph showing the stability of the second factor curable resin composition under sunlight. Applicant Canon Co., Ltd.

Claims (1)

[Claims] A curable resin composition comprising a polymer having a polymerizable unsaturated acrylic group and an organic solvent-compatible S-wave acrylic thermoplastic resin, and containing no polymerization initiator.