JPH0564165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a radiation-curable resin that is cured by radiation such as ultraviolet rays or electron beams to form a strong coating film.

Structure of conventional example and its problems In recent years, many resins that are cured by radiation such as ultraviolet rays and electron beams have been commercially available. These resins have become widely used because they cure in a much shorter time than conventional thermosetting resins and exhibit superior properties. However, many of these resins are esters such as acrylates, methacrylates, and arylates, or polyester resins, so they have problems such as poor chemical resistance and solvent resistance, which limits their range of use, or poor heat resistance. have. Additionally, the surface hardness of these resins is generally inferior to that of resins with excellent surface hardness such as phenolic resins, and if they are intentionally made particularly hard, the adhesion and flexibility will be poor, and low molecular weight compounds Because of the use of paint, it has drawbacks such as poor leveling properties when used as a paint. On the other hand, as is well known, phenolic resins, xylene resins, etc. have the drawback of requiring high temperatures and long periods of time for curing.

Purpose of the Invention The purpose of the present invention is to cure quickly with radiation such as ultraviolet rays or electron beams, exhibit excellent surface hardness and adhesion, and exhibit remarkable heat resistance and solvent resistance not found in conventional radiation-curable resins. The object of the present invention is to provide a resin having properties.

Structure of the Invention In order to achieve this object, the present invention is made by converting the hydroxyl group or methylol group of a phenol-modified xylene resin into an acrylic acid or methacrylic acid ester, and using the following structure as a monomer unit.

(However, R is a hydrogen atom, an acryloyl group, or a methacryloyl group.) The radiation-curable resin according to the present invention is cured in a short time by ultraviolet rays, infrared rays, or electron beams, and as shown in the examples, is smooth and smooth. It also provides a coating film with high surface hardness and is particularly suitable as a paint resin. Moreover, this resin is not only preferable for general paints, but also exhibits a remarkable effect in dispersing magnetic powder when used in paints for magnetic recording media. For this reason, it is also optimal as a resin for addition to electron beam curable magnetic ink.

Description of examples Examples will be explained below.

(Example 1) A commercially available phenol-modified xylene resin (J made by Matsushita Electric Works Co., Ltd.) was placed in a flask equipped with a thermometer and a stirrer.
-1000) at a weight ratio of 1:1, and methanol contained in the phenol-modified xylene resin was removed under reduced pressure. Acrylic acid was added to the resin without methanol at a weight ratio of approximately 5:3, and P-toluenesulfonic acid was added at 0.3% based on the solid content of the resin, and the mixture was heated at 60°C± under reduced pressure.
React at 1°C for 6 hours. After the reaction, unreacted acrylic acid is removed under reduced pressure to obtain an ester solution.

The infrared absorption spectrum of the resin thus obtained is shown in FIG. 1, and the same spectrum of a commercially available phenol-modified xylene resin (J-1000, manufactured by Matsushita Electric Works, Ltd.) is shown in FIG.

It can be seen that the absorption at 1405 cm ^-1 in the spectrum shown in Figure 1 is vinyl absorption, and that an acryloyl group has been introduced.

2% benzoin ethyl ether, which is a photopolymerization initiator, is added to the resulting solution based on the resin, and it is applied onto an alumina substrate using a 25 μ doctor blade. After drying, an energy of 120 W/cm is applied. Irradiation was performed for 30 seconds from a high-pressure mercury lamp at a distance of 10 cm. The coating film thus obtained was extremely smooth and hard, exhibiting a pencil hardness of 5H. This is 350
When it was immersed in solder at ℃ for 10 seconds, it only turned brown and no peeling or cracking of the paint film was observed. Further, no abnormality was observed even when this was ultrasonically cleaned in Triclean. For comparison, when we conducted a solder immersion test at 350°C on a commercially available ultraviolet curing resin, the resin decomposed and generated gas. In addition, when ultrasonic cleaning was performed in Triclean, a decrease in surface hardness was observed.

Next, 50μ of this solution was applied directly onto the iron plate, and after drying, an electron beam with an energy of 165KeV was applied.
When irradiated with 10 Mracl, a hard coating film with a pencil hardness of 7H was obtained. This coating film is then heated to 190℃.
Post-cure for 5 minutes with
It rose to 9H.

(Example 2) In Example 1, methacrylic acid was used instead of acrylic acid, and the reaction was carried out at 60°C±1°C for 6 hours. Figure 3 shows the infrared absorption spectrum of this resin.

2% of benzoin ethyl ether was added to the solid content of the resulting solution, and when it was applied onto an alumina substrate, dried, and irradiated with ultraviolet rays for 30 seconds, a coating film with a pencil hardness of 6H was obtained. Ta. This coating did not peel or crack in the solder immersion test at 350°C.

Next, apply this solution on the iron plate and after drying,
When irradiated with 10Mracl of 165KeV electron beam, 8H
A hard coating film was obtained with a pencil hardness of . This coating film was then post-cured at 190°C for 5 minutes, and the pencil hardness increased to 9H or higher.

In addition, coatings made by applying this solution onto a paper-based phenolic resin board, drying it, and curing it by irradiating it with electron beams are also available.
Shows 8H pencil hardness, cellophane tape peeling (checkerboard)
It showed 100% adhesion in the test.

The phenol-modified xylene resin used in the present invention is one obtained by modifying a xylene resin with a trifunctional phenol, as described in, for example, Industrial Chemistry Magazine, Vol. 58, page 517 (1955). Therefore, the phenol-modified xylene resin contains a methylol group as a functional group.

The radiation-curable resin of the present invention is obtained by esterifying the methylol group and hydroxyl group in the phenol-modified xylene resin with acrylic acid or methacrylic acid, and has the following structure as a monomer unit.

However, R is a hydrogen atom, an acryloyl group, or a methacryloyl group.

Effects of the Invention As described above, the radiation-curable resin according to the present invention is cured by various types of radiation, and has surface hardness, solvent resistance, and heat resistance that conventional similar resins do not have, as well as flatness and adhesion. It provides an excellent coating film, and has great industrial effects.

[Brief explanation of the drawing]

Figure 1 shows the transmittance in infrared spectroscopic analysis of a radiation-curable resin according to the present invention esterified with acrylic acid, and Figure 2 shows the transmittance in infrared spectroscopic analysis of a commercially available phenol-modified xylene resin. FIG. 3 is a diagram showing the transmittance in infrared spectroscopy of the radiation-curable resin according to the present invention, which has been esterified with methacrylic acid.

Claims (1)

[Scope of Claims] 1. A radiation-curable resin characterized in that the hydroxyl group or methylol group of a phenol-modified xylene resin is converted into an acrylic acid or methacrylic acid ester, and the monomer unit has the following structure. (However, R is a hydrogen atom, an acryloyl group, or a methacryloyl group.)