JPH02274713A - Photocurable resin - Google Patents

Abstract

PURPOSE:To obtain a polyurethane acrylate which can be used as a nonyellowing base resin and is useful for obtaining a photocurable resin composition excellent in surface curability by selecting a specified polyurethane acrylate. CONSTITUTION:A polyurethane acrylate of formula l [wherein R groups are groups of formula II and/or formula III (wherein R) is II or CH3; R<2> is an ethylene or propylene group; and (n) is 1 to 6)] is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel polyurethane acrylate and a photocurable resin composition containing the same.

BACKGROUND OF THE INVENTION Generally, a photocurable resin is used as a component of a photocurable resin composition comprising a reactive diluent, a photopolymerization initiator, and the like. Conventionally, polyurethane acrylate, polyester acrylate, epoxy acrylate, etc. have been mainly used as photocurable resins. Among them, polyurethane acrylate has particularly excellent curability, flexibility, abrasion resistance, adhesion, etc. Therefore, it is used in a wide range of fields such as coating agents for various plastics, overprint surfaces, wood paints, paints for PVC flooring, and various printing inks.

Problem to be SolvedHowever, when polyurethane acrylate is used as a clear coating agent for overprint surfaces that do not contain pigments, fillers, etc., the cured polyurethane acrylate film is colorless and transparent. It is required that
Therefore, the condition is that there is no yellowing. Therefore, non-yellowing isophorone diisocyanate and the like are used as isocyanate compounds used in the synthesis of polyurethane acrylates, but when such compounds are used, the problem of yellowing on the surface of the coating film is resolved, but On the other hand, the problem remains that the surface hardening properties of the coating film are insufficient.

The present invention was made in order to solve these problems, and it is a photocurable resin that has the original performance as a photocurable resin, is non-yellowing, and has excellent surface curing properties. The object of the present invention is to provide a photocurable resin composition.

(CH2)6 NHCO-R [wherein, R is the general formula CH2-CR' Coo R2-0eco CH
2CH2CH2CH2CH20+n and/or general formula % formula % (wherein R1 represents a hydrogen atom or a methyl group, R2 represents an ethylene group or a propylene group, and n represents an integer of 1 to 6.

). ] It concerns on the photocurable resin composition characterized by containing the polyurethane acrylate shown by these and said polyurethane acrylate as a base resin.

As a result of intensive research, the present inventors have found that by using the polyurethane acrylate of the above formula (I) as a base resin of a photocurable resin composition, it is possible to express the original performance as a photocurable resin. It has been found that a photocurable resin and a photocurable resin composition which are non-yellowing and have excellent surface curability can be obtained.

The polyurethane acrylate of the present invention represented by the above formula (I) has 1, 3. represented by the formula (n) (CH2) 6 NGO. 5 Tris (isocyanatohexyl) 1, 3. 5 Triazine-2,4゜6- (IH,3H,5H) General formula (m
)CH2-CRI -Coo-R2-0+co-CH2
CH2CH2CH2CH2O桔H(m) (In the formula, R1 is a hydrogen atom or a methyl group, R2 is an ethylene group or a propylene group, and n is an integer of 1 to 6.)
ε-caprolactone modified vinyl monomer and general formula CIV) CH2=CRI-Coo-R2-OH (IV) (in the formula,
R1 and R2 are the same as above. ) can be obtained by reacting at least one hydroxy-containing vinyl compound selected from hydroxyacrylate monomers represented by:

In the present invention, 1,3.5 represented by formula (n) used as an isocyanate compound as a hard segment
-Tris(isocyanatohexyl')-1,3,5-
)Ryazine-2,4,6-(IH,3H,5H))-ion is a known compound, and can be obtained, for example, by trimerizing hexamethylene diisocyanate. An example thereof is the product name Coronate EH1 manufactured by Nippon Polyurethane Industries Co., Ltd., and the like.

Furthermore, the hydroxy-containing vinyl compounds of general formulas (m) and (IV), which are soft segments to be reacted with the isocyanate compound of formula (n) above, are all known compounds. The ε-caprolactone-modified vinyl monomer represented by the general formula (m) can be obtained, for example, by ring-opening addition polymerization of ε-caprolactone to a hydroxyacrylate monomer represented by the general formula (IV). Specific examples include the trade names Plaxel FA-1, Plaxel FA-4, manufactured by Daicel Chemical Industries, Ltd., and the like. In the above compound, the average value n of the number of moles of ring-opening addition of ε-caprolactone to 1 mole of hydroxyacrylate monomer is 1 to 6, and when n exceeds 6, the resulting cured film becomes brittle, which is not preferred.

Further, examples of the hydroxyacrylate monomer represented by general formula (IV) include 2-hydroxyethyl acrylate, 2-hydroxymethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate.

The method for producing the polyurethane acrylate of the present invention is not particularly limited, and usually uses an isocyanate compound represented by formula (II), general formula (m) and general formula (IV
) A method may be adopted in which one or more of the hydroxy group-containing vinyl compounds represented by the following formulas are simultaneously charged and reacted. The mixing ratio is 1 mole of formula (■) to 1 mole of general formula (I
It is preferable that the total number of moles of II) and/or general formula (IV) is 3 moles, but even if it exceeds 3 moles, the excess vinyl compound remains unreacted and is mixed with the desired product. The vinyl compound is present in the reaction mixture and acts as a reactive diluent for the photocurable resin composition (therefore, an excess of the vinyl compound may be used if necessary).

Further, it is also optional to use a catalyst such as stannous octylate, if necessary. The amount used is 100 of the total amount of preparation.
It is preferably 0.02 to 0.05 parts by weight.

Usually, the reaction is carried out under heating, but it is preferable to use mild heating conditions of about 70 to 80°C. Reaction time is 2-3
About an hour is normal.

Completion of the reaction can be easily confirmed by quantifying isocyanate residues using IR.

The photocurable resin composition of the present invention uses the polyurethane acrylate as a base resin, and may further contain reactive diluents, photopolymerization initiators, additives, pigments, etc. as necessary.

Examples of the reactive diluent include N-vinylpyrrolidone, 2-ethylhexyl acrylate, ethylcarpitol acrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, phenoxyethyl acrylate, and other various known reactive diluents. can be used.

Photopolymerization initiators include benzophenone, benzyl methyl ketal, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl 1-phenylpropane.
Various known materials such as 1-one can be used.

Further, examples of additives include antifoaming agents, leveling agents, matting agents, etc., and these can be appropriately selected and used depending on the purpose.

The above base resin in the photocurable resin composition of the present invention,
The proportions of other ingredients such as reactive diluents, photopolymerization initiators, and additives are not particularly limited and can be selected from a wide range depending on the purpose and use of the resulting photocurable resin composition. The following ranges are preferred. The base resin preferably accounts for at least 10% by weight of the photocurable resin composition. Preferably it is 10 to 90% by weight. When the amount is less than 10% by weight, it is difficult to obtain a cured coating film with excellent surface curability. That is, the compounding ratio of the photocurable resin composition is 10 to 90% by weight of the base resin, 5 to 60% by weight of the reactive diluent, 1 to 10% by weight of the photopolymerization initiator, and other additives, pigments, etc. The content is preferably 0 to 20% by weight.

Effects of the Invention The photocurable resin composition containing the polyurethane acrylate of the present invention not only has excellent curability, flexibility, abrasion resistance, and adhesion, which are characteristics of photocurable resins. When used as a clear coating agent, it does not cause yellowing and has excellent surface hardening properties.

Therefore, it can be used not only in applications for which photocurable resins have traditionally been used, but also in a wide range of fields such as various plastic coatings, overprint surfaces, wood coatings, PVC floor coatings, and various printing inks.

EXAMPLES The present invention will be specifically described below with reference to production examples, working examples, and comparative examples, but the present invention is not limited to these examples.

Production Example 1 1.3.5-tris(isocyanatohexyl)- was placed in 11 four-eye flasks equipped with a stirrer, a thermometer, and a condenser.
1,3,5-1 riazine-2,4゜6- (IH,3H
, 5H) Trion (trade name: Coronate EH1, manufactured by Nippon Polyurethane Industries, Ltd., isocyanate group content: 21
．． 3%) 300g (0°51 mol), ε-caprolactone-β-hydroxyethyl acrylate adduct (n-1 in general formula (m)) (trade name Plaxel FA-1, manufactured by Daicel Chemical Industries, Ltd.) 352g (1,53 mol),
4 methoxyphenol 0.652g (1000ppm
) and gradually heat while stirring. 7 over 1.5 hours while paying attention to the heat generated by the reaction.
The temperature was raised to 5°C, and after keeping at 75-80°C for 1 hour, 0.130 g (200 ppm) of stannous octylic acid was added, and the temperature was kept for another 1 hour. Remaining Ison Ana-1 in IR
After confirming that the base had disappeared, cooling was performed to obtain 652 g of a pale yellow viscous liquid. This was designated as resin A.

Production Example 2 300g of Coronate EH was placed in the same reaction apparatus as Production Example 1.
(0.51 mol), ε-caprolactone β-hydroxyethyl acrylate adduct (n=4 in general formula (III)
) (trade name Plaxel FA-4, manufactured by Daicel Chemical Industries, Ltd.) 145. 9g (0°255 mol), 2-hydroxyethyl acrylate) 147.9g (1,27
5 mol) was charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 593 g of a pale yellow viscous liquid. This was designated as resin B.

Production Example 3 Coronate EH3] 200 g (0.51 mol) and Plaxel FA-4291 were placed in the same reaction apparatus as Production Example 1.
, 7 g (0.51 mol) and 118.3 g (1.02 mol) of 2-hydroxyethyl acrylate were charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 710 g of a pale yellow viscous liquid. This was designated as resin C.

Production Example 4 100g of Coronate EH was placed in the same reactor as Production Example 1.
(0.17 mol), Plaxel FA-4194, 5g
(0.34 mol) and 19.7 g (0.17 mol) of 2-hydroxyethyl acrylate were charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 314 g of a pale yellow viscous liquid. This was made into resin.

Production Example 5 300g of Coronate EH was placed in the same reactor as Production Example 1.
(0.51 mol) and 177.5 g (L 5B mol) of 2-hydroxyethyl acrylate were charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 477 g of a pale yellow viscous liquid. This was designated as resin E.

Production Example 6 222.3 g (1,00 mol) of isophorone diisocyaner and Plaxel FA-
1460.0 g (2.00 mol) was charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 682 g of a pale yellow viscous liquid. This was designated as Resin F.

Production Example 7 Into the same reaction apparatus as in Production Example 1, 271.0 g (1,22 mol) of isophorone diisocyanate and 265°0 g of polyester diol (cocondensate of adipic acid and 1,4-butanediol, average molecular weight 500) were added. (0,!53 mol), 2-hydroxyethyl acrylate) 160.0g
(1.38 mol) was charged and the reaction was carried out in the same manner as in Production Example 1 to obtain 696 g of a pale yellow viscous liquid. This was designated as Resin G.

Example 1 75 parts by weight of the resin A obtained in Production Example 1, 25 parts by weight of tetraethylene glycol diacrylate as a reactive diluent, and 3 parts by weight of a photopolymerization initiator (trade name Darocure-1173, manufactured by Merck Co., Ltd.) A composition consisting of the following was mixed, a sample was prepared, and the sample was subjected to the following test.

Examples 2 to 5 and Comparative Example 1.2 The compositions were mixed in the same manner as in Example 1 except that resin A was changed to resins B-G, samples were prepared, and the samples were subjected to the following tests.

Example 6 As a reactive diluent, 25 parts by weight of phenoxyethyl acrylate was mixed in place of 25 parts by weight of tetraethylene glycol diacrylate, a sample was prepared, and the sample was subjected to the following test.

Examples 7 to 10 and Comparative Example 3.4 The compositions were mixed in the same manner as in Example 6, except that resin A was changed to resins B-G, and samples were prepared and subjected to the following tests.

Various performance test methods> Performance tests were conducted using the samples obtained in each of the above Examples and Comparative Examples using the following methods.

1 Curing test Sample obtained on glass plate] Second applicator to film thickness 2
The cure property was measured by changing the irradiation dose under the conditions of one 80 W/cm high-pressure mercury lamp and an irradiation distance of 10 cm. Curability was judged by lightly rubbing the surface of the cured film immediately after curing with the tip of a fingernail, and visually judging the scratchability of the surface.

○...No scratches remain.

△...Slight scratches remain.

×... Scratches remain clearly.

2 Pencil hardness curability test (Pencil hardness was measured using a cured film obtained at an irradiation dose of 192 mD (JIS K5400).

3. Elongation/strength The cured film obtained in the hardening test (irradiation dose: 192 jm) was used to measure the elongation/strength.

Test piece: Width: 6 mm, length: 5 cm (distance between chucks: 2.5 cm) Elongation: Pulled at a pulling speed of 50 mm/min,
The elongation rate with respect to the length at break was measured.

Strength: It was pulled at 50 mm/min and the load at break was measured.

4. Yellowing Test Using the curable film obtained in the curability test (irradiation dose: 192 m), ΔE was measured after 300 hours of sunshine weather off-site (JIS K 7105).

The results obtained are shown in Table 1 below.

Department table (Hereafter oneto) 1

Claims (2)

[Claims] (1) Formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R is the general formula CH_2=-CR^1-COO-R^2-O-(CO-
CH_2CH_2CH_2CH_2CH_2O)-_n
and/or the general formula CH_2=CR^1-COO-R^2-O- (wherein R
^1 represents a hydrogen atom or a methyl group, R^2 represents an ethylene group or a propylene group, and n represents an integer of 1 to 6. ). ] Polyurethane acrylate shown by. (2) A photocurable resin composition containing the polyurethane acrylate according to claim 1 as a base resin.