JPH0629314B2 - Radical polymerizable urethane oligomer - Google Patents

Description

Detailed Description of the Invention A. INDUSTRIAL APPLICABILITY The compound of the present invention can be homopolymerized or copolymerized with an appropriate reactive monomer by using heat, ultraviolet rays, electron beams, etc., and is used for immobilizing paints, inks, adhesives, and yeasts. The present invention relates to a method for producing a radical-polymerizable urethane compound which is used as a dental filling material and the like and is also useful as a printing plate material, a photoresist, a resist ink for printed wiring, and the like by utilizing the property of being cured by ultraviolet rays.

B. 2. Description of the Related Art Radical-polymerizable urethane oligomers are often used as UV-curable prepolymers. The ultraviolet curable resin is a resin that changes from a liquid state to a solid state by irradiation with ultraviolet rays, and is usually composed of a reactive prepolymer, a reactive diluent and a photopolymerization initiator. The mainstream of this reactive prepolymer is an acrylic prepolymer.

Acrylic prepolymers include polyester acrylate type, epoxy acrylate type, urethane acrylate type, and the like, and prepolymers are appropriately used depending on the function and application.

Among them, the urethane acrylate type has a better air-curing property than other prepolymers and forms a tough coating film as compared with other prepolymers, as pointed out in Japanese Examined Patent Publication Nos. 48-41708 and 55-8013. It is expected to be promising in the future because it has excellent adhesiveness and, on the other hand, it can be expected to develop urethane acrylates having various different structures depending on the reactivity of isocyanate.

C. Problems to be Solved by the Invention As described above, when a urethane acrylate is produced, various molecular designs are possible due to the high reactivity of isocyanates, but there are many possibilities. There are few types of urethane acrylates available on the market. Among them, urethane acrylates having hardness, adhesion to iron surface and flexibility that are further excellent than those of conventional ones are currently desired.

D. Means for Solving the Problems In view of such a situation, the present inventors have made diligent studies, and as a result, the following (a) component, (b) component, (c) component (a) polyisocyanate (b) Bisphenol S (c) Compound represented by the following general formula (I) (In the formula, R ₁ is H or CH ₃ , n = 1 to 10), and the radically polymerizable urethane compound is a reaction product,
The present invention has been completed by finding that a cured product having excellent hardness, adhesion to an iron surface, and flexibility is produced.

The present inventors previously invented an oligomer having a structure similar to this substance and filed a patent application (Japanese Patent Application No. 59-14713).
3).

The present invention further improves the substances described in such patents, and provides a urethane compound exhibiting not only hardness and adhesion to an iron surface but also excellent flexibility.

The radically polymerizable urethane compound of the present invention is produced, for example, as follows.

Ratio of polyvalent isocyanate to hydroxyl group (OH / NCO) ≦
It is charged at a ratio of 1 (mol / mol) to produce a terminal isocyanate oligomer. Next, polycaprolactone (meth) acrylate [general formula (I)] is added and reacted at a ratio of hydroxyl groups per isocyanate group (OH / NCO) ≧ 1. The reaction is preferably carried out in a solvent such as tetrahydrofuran or methyl ethyl ketone. As the reaction catalyst, metal salts such as dibutyltin dilaurate and lead naphthenate, tertiary amines and the like are used. Hydroquinone, p-benzoquinone, p-cresol and the like may be added as a polymerization inhibitor. The reaction temperature is preferably 80 ° C or lower.

As the polyvalent isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4 and 2,6-
Tolylene diisocyanate mixture, 4,4'-diphenylmethane diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate , 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5- Naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate and the like are used.

E. Examples Examples are shown below.

[Example 1] 174 g (1.0 mol) of 2,4-tolylene diisocyanate (TDI) [manufactured by Tokyo Kasei Co., Ltd.] and bisphenol were placed in a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer. S
125 g (0.5 mol) and tetrahydrofuran (THF) 50
0 ml was added. Next, 0.2 g of dibutyltin dilaurate was added and heated. Although the reaction was exothermic at the start of the reaction, the maximum temperature during the reaction was 72 ° C. After the temperature rise due to the exotherm was completed, stirring was continued at 60 ° C. for about 2 hours. 0.02 g of hydroquinone monomethyl ether (MEHQ) was added to the obtained reaction product,
Praxel FA-1 [Daicel Chemical Industry Co., Ltd.] 230g
(1.0 mol) was added. Even in this case, the maximum temperature during reaction is 7
It was 0 ° C. After the exotherm was over, stirring was continued at 60 ° C. for about 1 hour. The obtained reaction product was subjected to T using an evaporator.
After distilling off HF, it was dried under reduced pressure at 40 ° C for 3 hours (5 mmH
g) to give a solid pale yellow substance.

The characteristic IR peak of this pale yellow substance is shown below.

Absorption of isocyanate groups of 2270 ^-1 cm was not observed at all.

Example 2 The 2,4-tolylene diisocyanate of Example 1 was added to isophorone diisocyanate (IPDI) and Praxel FA-
1 was changed to Praxel FA-5, and otherwise, Example 1
It carried out similarly to. As a result, a transparent viscous substance was obtained.

(Note) Praxel FA-1 Praxel FA-5 [Effects of the Invention] Using the urethane oligomers obtained in Examples 1 and 2, photocurable resins were obtained with the formulations shown in Table-1.

Apply the resin obtained in the formulation of Table-1 on a steel plate and apply 120W
/ Cm output of a high pressure mercury lamp 10 cm directly under 10 seconds still exposure, to obtain a coating film. Table 2 shows the results of physical property tests of the obtained coating film.

Claims (1)

[Claims] 1. When producing a reaction product of the following components (a), (b) and (c), (a) a polyvalent isocyanate (b) bisphenol S. (c) Compound represented by the following general formula (I) (In the formula, R ₁ is H or CH ₃ , n = 1 to 10) The ratio of the isocyanate group to the hydroxyl group (O)
H / NCO) ≦ 1 (mol / mol), the terminal isocyanate oligomer to be reacted is produced, and the terminal isocyanate oligomer and the component (c) are reacted with each other at a ratio of isocyanate groups to hydroxyl groups (OH / NCO) ≧ 1 (mol / mol). Mol) in the reaction.