JPH0143769B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photocurable urethane acrylic resin composition that has excellent adhesion to synthetic resins, particularly vinyl chloride resins. Photocurable urethane acrylic resins are widely used for surface coating of various materials, adhesives, various binders, etc., but none have been found to have sufficiently satisfactory adhesion to synthetic resins, especially vinyl chloride resins. However, as a result of intensive studies aimed at improving the adhesive performance of photocurable urethane acrylic resin without impairing its photocurability, the inventors found that 1.4-
Using a low molecular weight polyester resin (A) containing cyclohexanedimethanol as a polyhydric alcohol component, this is reacted with a diisocyanate compound (B), and then an active hydrogen-containing acrylic monomer is added to this.
The present inventors have discovered that the above object can be achieved by using a prepolymer obtained by reacting (C) as a base polymer, and have completed the present invention. Low molecular weight polyester resin (A) in the present invention
is a polyester resin containing 5 mol% or more of 1,4-cyclohexanedimethanol as a polyhydric alcohol component or 5 mol% of 1,4-cyclohexanedimethanol as a polyhydric alcohol component
It also contains a mixed polyester resin of a polyester resin containing the above and a polyester resin that does not contain any 1,4-cyclohexanedimethanol as a polyhydric alcohol component, and the prepolymer contains at least 2% by weight of 1,4-cyclohexane. There is no problem as long as it contains dimethanol. The low molecular weight polyester resin (A) contains, in addition to 1,4-cyclohexanedimethanol, succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, phthalic anhydride, maleic acid, maleic anhydride, and itaconic acid. , dicarboxylic acids such as terephthalic acid and isophthalic acid, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol,
Dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, hydrogenated bisphenol A, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone, glycerin, trimethylolethane, It is obtained by a normal esterification reaction using a polyhydric alcohol such as methylolpropane as a reaction component. The molecular weight is adjusted by the type of dicarboxylic acid and polyhydric alcohol and the hydroxyl value, and the hydroxyl value is approximately in the range of 335 to 55 (KOHmg/g).
The molecular weight must be in the range of 500 to 2000. If it deviates from this range, various drawbacks such as a decrease in adhesive strength to the material, a decrease in hardness, and residual tackiness are observed, which is not preferable. Next, when reacting the obtained low molecular weight polyester resin (A) with the diisocyanate compound (B), (A)
The ratio of the number of hydroxyl groups in (B) to the number of isocyanate groups in (A)/
(B) is used so that it is in the range of 0.3 to 0.9, and the reaction is carried out in an inert gas at 60 to 100°C until the remaining NCO groups in the resin are 70 to 10% of the original amount. Furthermore, when the active hydrogen-containing acrylic monomer (C) is subsequently reacted, the ratio of the number of isocyanate groups in (B) to the number of active hydrogen groups in (C) is (C)/(B) = 0.75 to 0.1. Using (C) at a ratio of
A polymerization inhibitor and a urethanization catalyst are added as necessary, and the reaction is carried out at a temperature of 40 to 50°C until the concentration of residual NCO groups in the obtained prepolymer becomes 1% or less. As the diisocyanate compound (B), 2.4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, P-xylylene diisocyanate, diphenylmethane 4,4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, these modified diisocyanates, hydrogenated Examples include diisocyanates, which may be used alone or in combination of two or more. As the active hydrogen-containing acrylic monomer (C), 2
-Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, N-vinylpyrrolidone, 2-
Hydroxyethyl acryloyl phosphate,
Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methoxymethyl acrylamide, N
Examples include -ethoxymethylacrylamide, ethylene glycol monoacrylate, dipropylene glycol monoacrylate, and N,N-dimethylaminoethyl acrylate, which may be used alone or in combination of two or more. As the copolymer monomer in the present invention, the above-mentioned
In addition to (C), styrene, vinyltoluene, α-methylstyrene, methyl methacrylate, methyl acrylate, ethyl acrylate, acrylonitrile,
Vinyl acetate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, phenoxy acrylate,
Dicyclopentenyl acrylate, lauryl methacrylate, furfuryl acrylate, carbitol acrylate, benzyl acrylate, butoxyethyl acrylate, allyl acrylate,
Phenoxyethyl acrylate, acryloxyethyl phosphate, 2-vinylpyridine, etc.
Furthermore, other known materials may be used. The ratio of the monomer to the prepolymer is suitably in the range of 25 to 60% by weight of the total amount. Examples of the photopolymerization initiator in the present invention include benzoin, benzoin methyl ether, benzoin propyl ether, benzoin n-butyl ether, benzoin phenyl ether, anthraquinone, naphthoquinone, benzophenone, pivaloin ethyl ether, benzoyl peroxide, benzyl ketal, 1・1-dichloroacetophenone, para-t-butyldichloroacetophenone,
2-chlorothioxanthone, 2,2-diethoxyacetophenone, Michler's ketone, 2,2-dichloro-4-phenoxyacetophenone, phenylglyoxylate, α-hydroxyisobutylphenone, dibenzosparone, benzophenone
Examples include amines (N-methyldiethanolamine, triethylamine), etc., and the amount thereof to be blended in the composition is appropriately selected from a range of approximately 1 to 10% by weight. When the composition of the present invention is used as a top coat for various substrates, a roll coater,
Apply an appropriate amount with a spray, etc., and apply a high pressure mercury lamp.
Light is irradiated using a medium-pressure, high-output mercury lamp, etc. The curing time varies depending on the amount of coating and the output of the light source, but when irradiated with a high-pressure mercury lamp (80 W/cm) at a height of 10 cm and the conveyor belt speed is 6 m/min, it will cure in approximately 1 to 10 seconds. The composition of the present invention is suitable for use as a top coat for various substrates such as paper, paperboard, fibers, plywood, woodwork, metal products, plastic molded products (films, sheets, molded products, etc.), and is particularly suitable for use on vinyl chloride. It has excellent adhesion performance to vinyl chloride resin molded products such as resin tiles, sheets, and films. Furthermore, when blended with other photocurable acrylic resins, the adhesion of that resin to vinyl chloride resins can be improved. Next, the present invention will be specifically explained with reference to Examples. In addition, "parts" in the examples represent "parts by weight" unless otherwise specified. Example 1 In a 2-volume flask equipped with a stirrer, thermometer, _N2 inlet, and water-cooled condenser, 591 parts of adipic acid were added.
224 parts of isophthalic acid, 389 parts of 1,4-cyclohexanedimethanol, 396 parts of diethylene glycol, and 0.8 parts of dibutyltin oxide were charged.
Reacted at 240℃ for 15 hours, acid value 1.2 (KOHmg/g),
A low molecular weight polyester resin (a) having a hydroxyl value of 85 (KOHmg/g) and a number average molecular weight of 1350 was obtained. In the same manner as above, 625 parts of the polyester resin (A) and 121 parts of tolylene diisocyanate were placed in a 1-volume flask, and reacted at 60 to 100°C for 6 hours to determine the NCO group concentration.
A 2.7% polyurethane precursor was obtained, and then the precursor was cooled to below 40°C, and then 55 parts of 2-hydroxyethyl acrylate, 0.32 parts of monomethyl ether hydroquinone, and dibutyltin dilaurate were added.
Add 0.08 parts and react at 40-50℃ for 9 hours to convert NCO.
A prepolymer with a group concentration of 1% or less was obtained. To 100 parts of this prepolymer, 50 parts of 2-hydroxypropyl methacrylate, 50 parts of 1,6-hexanediol diacrylate, and 3 parts of Irgakyure I-651 (manufactured by Ciba Geigy) were added to form a uniform solution. Next, use bar coater #16 on each hard, semi-hard, and soft vinyl chloride resin sheet (thickness 50μ).
Apply the resin solution and heat it with a high pressure mercury lamp (80W/cm,
(at a height of 10cm) below, conveyor belt 6m/min
The curing time was defined as the irradiation time required to become tack-free at a speed of . Furthermore, it was applied onto a glass plate coated with a release agent using an applicator of 0.2 mm, and irradiated with light in the same manner to produce a film with an average thickness of 100 μm, which was then subjected to a tensile test. The results are summarized in Table 1. Example 2 748 parts of adipic acid, 852 parts of 1,4-cyclohexanedimethanol, and 0.8 parts of dibutyltin oxide were charged into the same equipment as the polyester resin (a), and reacted at 220 to 240°C for 16 hours to give an acid value of 2.0. A low molecular weight polyester resin (b) having a hydroxyl value of 61 and a number average molecular weight of 1830 was obtained. Polyester resin (b) was added using the same equipment as in Example 1.
551 parts, 60 to 155 parts of isophorone diisocyanate
A polyurethane precursor with an NCO group concentration of 4.7% was obtained by reacting at 100°C for 6 hours, and then the precursor was cooled to below 40°C, and then 94 parts of 2-hydroxyethyl acrylate, 0.32 parts of monomethyl ether hydroquinone, and dibutyltin were added. Add 0.08 parts of dilaurate and react at 40 to 50℃ for 7 hours to achieve an NCO group concentration of 1%.
The following prepolymer was obtained. This prepolymer
50 parts of 1,6-hexanediol diacrylate, 2-ethylhexyl acrylate per 100 parts
50 parts of benzoin isopropyl ether and 3 parts of benzoin isopropyl ether were added to form a homogeneous solution. Various properties are summarized in Table 1. Control Example 1 In the same apparatus as in Example 1, 594 parts of adipic acid, 290 parts of isophthalic acid, and 265 parts of 1,4-butanediol were added.
1 part, diethylene glycol 451 parts, and dibutyltin oxide 0.8 parts, and reacted at 220 to 240°C for 16 hours to obtain an acid value of 1.5, a hydroxyl value of 109, and a number average molecular weight.
A low molecular weight polyester resin (c) of 1050 was obtained. Polyester resin (c) was added to the same apparatus as in Example 1.
439 parts of isophorone diisocyanate and 223 parts of isophorone diisocyanate were reacted for 6 hours at 60 to 100°C, resulting in an NCO group concentration of 7.4.
% of polyurethane precursor was obtained, then the precursor was cooled to below 40°C, and then 138 parts of 2-hydroxyethyl acrylate, 0.32 parts of monomethyl ether hydroquinone and 0.08 parts of dibutyltin dilaurate were added at 40-50°C. time response,
A prepolymer with an NCO group concentration of 1% or less was obtained. To 100 parts of this prepolymer, 50 parts of 1,6-hexanediol diacrylate, 50 parts of 2-ethylhexyl acrylate, and 3 parts of benzoin isopropyl ether were added to form a uniform solution.
Various properties are listed in Table 1. Control Example 2 In a device similar to Example 1, bisphenol A type epoxy resin (Epicoat 834: manufactured by Ciel Chemical Co., Ltd.) was added.
616 parts, 184 parts of acrylic acid, 2.4 parts of trimethylammonium benzyl chloride, and hydroquinone
A ring-opening addition reaction was carried out at 80 to 90°C for 19 hours to obtain an epoxy acrylic prepolymer with an acid value of 0.5. To 100 parts of the prepolymer, 50 parts of 1,6-hexanediol diacrylate, 50 parts of 2-ethylhexyl acrylate, and 3 parts of benzoin isopropyl ether were added to form a uniform solution.
Various properties are listed in Table 1. Example 3 Into the same apparatus as in Example 1, 645 parts of adipic acid,
645 parts of 1,4-cyclohexanedimethanol, 310 parts of trimethylolpropane, and 0.8 parts of dibutyltin oxide were charged and reacted at 220 to 240°C for 12 hours to obtain an acid value of 1.3, a hydroxyl value of 252, and a number average molecular weight of 690.
A low molecular weight polyester resin (d) was obtained. In the same apparatus as in Example 1, 134 parts of the low molecular weight polyester resin (d) and 204 parts of the low molecular weight polyester resin (c) were added.
and 280 parts of isophorone diisocyanate were charged and reacted at 60 to 100°C for 5 hours until the NCO group concentration was 10.6.
% of polyurethane precursor was obtained, and then the precursor was cooled to below 40°C, and then 182 parts of 2-hydroxyethyl acrylate, 0.32 parts of monomethyl ether hydroquinone and 0.08 parts of dibutyltin dilaurate were added at 40-50°C. time response,
A prepolymer with an NCO group concentration of 1% or less was obtained. For 100 parts of this prepolymer, 100 parts of 2-ethylhexyl acrylate, 3 parts of benzophenone, N
-Methyldiethanolamine was added in a proportion of 1.5 parts to form a homogeneous solution. Various properties are listed in Table 1. Examples 4 to 5 Example 4 is the resin solution in Example 2 and Control Example 1
In Example 5, the resin liquid in Example 2 and the resin liquid in Control Example 2 were mixed uniformly at a weight ratio of 1/1. This is the case of a resin liquid uniformly mixed at a ratio of . Various properties are listed in Table 1.

【table】

[Table] (2) Tensile test Autograph (manufactured by Shimadzu Corporation) at 20℃, 65
A tensile test was conducted at a tensile speed of 2.5 mm/min under the condition of %RH.

Claims (1)

[Claims] 1. In a photocurable resin composition comprising a prepolymer, a copolymerizable monomer, and a photoinitiator, 1.
A prepolymer obtained by reacting a low molecular weight polyester resin (A) containing 4-cyclohexanedimethanol as a polyhydric alcohol component with a diisocyanate compound (B), and then reacting with an active hydrogen-containing acrylic monomer (C). A photocurable urethane acrylic resin composition characterized by using.