JPH09279076A - Ultraviolet curable ink composition based on urethane acrylate and application film for marking using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet curable ink compsn. based on a urethane acrylate resin which are excellent particularly in processability, deposition, weather resistance and other properties. SOLUTION: This ultraviolet curable ink compsn. based on an urethane acrylate resin comprises as indispensable components a urethane acrylate oligomer (A), with a wt. average mol.wt. of 1,000 to 5,000, having about two or more, on average, (meth)acryloyl groups in one molecule and at least one urethane bond in one molecule, a monomer (B), with a wt. average mol.wt. of 85 to less than 1,000, having about one or more, on average, polymerizable double bonds in one molecule, an aliph. and/or an alicyclic polyisocyanate compd. (C), and an ultraviolet polymn. initiator (D), at least one of the oligomer (A) and the monomer (B) having a hydroxyl group.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel urethane acrylate resin-based UV-curable ink composition and a pressure-sensitive adhesive film for marking.

[0002]

2. Description of the Related Art Conventionally, a printing system using an ultraviolet curable ink is effective for, for example, a plastic material which is easily deformed by heat because it can be cured without heating or an inorganic material which has a large heat capacity and requires a long time for heating and cooling. It has advantages that it is used, and that it requires a smaller device than a hot-air stove, and that the curing time is short, so that the process can be shortened. As such an ultraviolet curable ink, one prepared by blending a polyacrylate oligomer, an acrylate monomer and an ultraviolet polymerization initiator is known. However, the cured film formed from this ultraviolet-curable ink is not always satisfactory in performance such as processability, adhesion to raw materials, and weather resistance. For this,
It could not be used for outdoor applications where durability is required.

[0003]

SUMMARY OF THE INVENTION The present invention has as its object the development of a urethane acrylate resin-based UV curable ink which is particularly excellent in performance such as processability, adhesion and weather resistance.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to solve the above-mentioned problems, a urethane acrylate resin-based UV-curable ink having a specific composition was found to be The inventors have found that all of the problems are solved and have completed the present invention.

That is, the present invention provides a urethane acrylate having a weight average molecular weight of 1,000 to 20,000, which has an average of about 2 or more (meth) acryloyl groups in one molecule and at least one urethane bond in one molecule. G-based oligomer (A), a monomer (B) having a weight average molecular weight of not less than 85 and less than 1000, having an average of about 1 or more polymerizable double bonds in one molecule, and less than 1000, an aliphatic and / or alicyclic group. Urethane acrylate containing a polyisocyanate compound (C) and an ultraviolet polymerization initiator (D) as essential components, and at least one of the oligomer (A) and monomer (B) components containing a hydroxyl group. -Resin-based UV-curable ink composition, 2. The above-mentioned urethane acrylate resin-based UV-curable ink composition, wherein the ink composition further contains a hydroxyl group-containing acrylate copolymer resin (E). A pressure-sensitive adhesive layer, a polyvinyl chloride film layer, a colored printing layer, and a clear ink coating layer, which are laminated in that order, and the clear ink coating layer is the urethane acrylate layer. A clear-curing coating formed from a resin-based UV-curable ink composition
Involved in adhesive film for king.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the ink composition of the present invention, the urethane acryl-based oligomer (A) and the monomer (B) used in the composition are irradiated with ultraviolet rays when the polymerizable initiator (D) is present. Causes the unsaturated group of the (meth) acryloyl group to undergo radical polymerization reaction and cure, and at the same time the oligomer
It is cured by a urethanization reaction between the hydroxyl group of (A) or the monomer (B) and the polyisocyanate compound (C). The urethanization reaction does not require heating like ultraviolet curing, and the curing rate is fast.

In the present invention, the curing by ultraviolet curing is excellent in weather resistance because the main chain is a bond with a (meth) acryloyl group, and the oligomer having the (meth) acryloyl group has a urethane bond as a side chain. The coating film having excellent processability is formed because it has Further, the curing by the urethane-forming reaction causes less volume shrinkage and the like, so that a film having excellent performance such as adhesion to a material and workability is formed.

The ink composition of the present invention will be described.

The urethane acrylate type oligomer (A) used in the ink composition of the present invention has an average of about 2 or more, preferably about 2 to 4 (meth) acryloyl groups in one molecule. It has a weight average molecular weight of 1,000 to 20,000, preferably 1,000 to 10,000, having at least one urethane bond in one molecule. (Meta)
When the average number of acryloyl groups is less than about 2, the cured film has poor performances such as hardness, weather resistance and stain resistance. On the other hand, if the weight average molecular weight is less than 1000, the hardness, workability and water resistance of the cured coating deteriorate, while if it exceeds 20,000, the printing workability deteriorates, which is not preferable.

The oligomer (A) containing a hydroxyl group or not containing a hydroxyl group can be used. When the oligomer (A) containing a hydroxyl group is used, As the monomer (B), those having a hydroxyl group or those not having a hydroxyl group can be used. Further, when the oligomer (A) having no hydroxyl group is used, the monomer ( B)
The one containing a hydroxyl group is used.

Urethane acrylate type oligomer (A)
Is, for example, polyol (ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, trimethylolpropane, glycerin, diglycerin, pentaerythritol. Etc.), polyester polyol, polycaprolactone polyol and polyether polyol, and a polyisocyanate compound are reacted with a hydroxyl group-containing compound to form a polyurethane polyol (two or more hydroxyl groups in one molecule). Polyurethane compound containing) or polyurethane polyisocyanate (polyurethane compound containing two or more isocyanate groups in one molecule) is prepared, and then polyurethane polyol and acrylate monomer containing isocyanate group are prepared. Or (meth) acrylic acid and polyurethane Cyanate - Doo and the hydroxyl group-containing acrylate -
It can be obtained by reacting tomonomers with each other while preventing the acrylic polymerization reaction. The oligomer (A) may or may not contain a hydroxyl group.

Preferred examples of the polyisocyanate compound include hexamethylene diisocyanate.
Aliphatic polyisocyanates, such as trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, pentamethylene diisocyanate, lysine diisocyanate, and isophorone diisocyanate. G, 4-4'-
Alicyclic polyisocyanates such as methylenebis (cyclohexyl isocyanate); biuret-type adducts of these polyisocyanates; and isocyanuric ring-type adducts. As the isocyanate group-containing acrylate monomer, for example, isocyanatoethyl (meth) acrylate and the like can be mentioned.

The hydroxyl group-containing acrylate monomer is, for example, 2-hydroxyethyl (meth) acrylate.
2-hydroxypropyl (meth) acrylate, 3
-Hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, (poly) alkylene glycol monoacrylate, and adducts of these monomers with lactones (eg, ε-caprolactone). Included.

The monomer (B) having a polymerizable double bond has a weight average molecular weight of 8 having an average of about 1 or more, preferably about 1 to 4 polymerizable double bonds in one molecule.
It is 5 or more and less than 1000, preferably in the range of 100 to 500. If the average number of polymerizable double bonds is less than 1, the curability will be poor. Further, those having a weight average molecular weight of less than 85 are difficult to obtain, while those having a weight average molecular weight of 1,000 or more are not preferable because the printing workability is deteriorated.

In the monomer (B) having a polymerizable double bond, as the monomer not containing a hydroxyl group, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- Butyl (meth) acrylate, isobutyl (meth) acrylate, tertbutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth)
Alkyl of (meth) acrylic acid such as acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexylcarbitol (meth) acrylate Or a cycloalkyl ester; an alkoxyalkyl ester of (meth) acrylic acid such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate; an aromatic alcohol such as benzyl (meth) acrylate and (meth) ) Ester with acrylic acid; glycidyl (meth) acrylate or hydroxyalkyl ester of (meth) acrylic acid with capric acid, lauric acid,
Adducts with monocarboxylic acid compounds such as linoleic acid and oleic acid, (meth) acrylic acid and "Cadula E10"
(Manufactured by Shell Chemical Co., Ltd.) and other adducts with monoepoxy compounds; styrene, α-methylstyrene, vinyltoluene,
Α, β-ethylenically unsaturated carboxylic acids such as (meth) acrylic acid and maleic acid; glycidyl (meth) acrylate, vinyl glycidyl ether; ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Chain alkyl vinyl ethers such as hexyl vinyl ether and octyl vinyl ether; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether; allyl ethers such as allyl glycidyl ether and allyl ethyl ether; perfluorobutylethyl (meth) acrylate, perfluoroisononylethyl ( Fluorine-containing unsaturated monomers such as (meth) acrylate, perfluorooctylethyl (meth) acrylate; (meth) acryloylmorpholine, 2-vinylpyridine, 1-vinyl-2-pyrrolidone, vinylcaprolactam, dimethyl (meth) ) Nitrogen-containing unsaturated monomers such as acrylamide, N, N-dimethylethyl (meth) acrylate; (poly) ethylene glycol, (poly) propylene glycol, Kisanjio - le, neopentyl glycolate - Le, trimethylolpropane - carboxyl group-containing monomers such as Le compound (meth) acrylic acid - - and 1 obtained by esterification reaction trimethylolpropane, polyhydric alcohols such as glycerine
Examples thereof include a monomer having two or more polymerizable double bonds in the molecule, and a monomer having a hydroxyl group.
Examples thereof include the hydroxyl group-containing acrylate monomers and the hydroxyl group-containing unsaturated monomers such as vinyl alcohol and allyl alcohol. These can be used alone or in combination of two or more. Among the above-mentioned monomers, it is particularly preferable to use a nitrogen-containing unsaturated monomer as an essential component.

In the present invention, the above-mentioned oligomer
The hydroxyl group contained in (A) and the monomer (B) reacts with the isocyanate group of the polyisocyanate compound (C) to form a cured ink film. The content of the hydroxyl group is preferably in the range of about 10 to 200, especially about 20 to 100 in terms of the total amount of oligomers (A) and (B). The compounding ratio of the above-mentioned oligomer (A) and monomer (B) is about 2 in total of both oligomers (A).
A range of 0 to 80% by weight, particularly about 30 to 70% by weight, a range of about 20 to 80% by weight of the monomer (B), especially a range of about 30 to 70% by weight are preferable. Oligomer (A) ratio is about 20
Less than wt% (monomer (B) exceeds about 80 wt%)
And the processability of the cured film deteriorates, while the oligomer (A)
Ratio exceeds about 80% by weight (about 2% for monomer (B))
If it is less than 0% by weight), the surface hardness of the coating film decreases, which is not preferable.

As the aliphatic and / or alicyclic polyisocyanate compound (C), the above-mentioned polyisocyanate is used.
The same compounds as those described above can be used. The compounding ratio of the polyisocyanate compound (C) is about 1 part by weight of the polyisocyanate compound (C) based on 100 parts by weight of the total amount of the oligomer (A) and the monomer (B).
A range of 50 parts by weight, especially about 3 to 20 parts by weight is preferred.
When the compounding ratio of the polyisocyanate compound (C) is less than about 1 part by weight, the coating performance such as weather resistance and adhesion is deteriorated, while when it exceeds about 50 parts by weight, the unreacted polyisocyanate compound (C) is used. ) Is increased, and the coating properties such as workability, weather resistance and water resistance are deteriorated, which is not preferable.

As the UV polymerization initiator (D), conventionally known ones can be used. Specifically, for example, 4-
Phenoxydichloroacetophenone, 4-ter-butyl-dichloroacetophenone, 4-ter-butyl-trichloroacetophenone, diethoxyacetophenone,
2-hydroxy-2-methyl-1-phenylpropane-
1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-
Dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyphenoxy)-
Phenyl (2-hydroxy-2-propyl) ketone, 1
-Hydroxycyclohexyl phenyl ketone, acetophenone compounds such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethyl Examples thereof include thioxanthone compounds such as thioxanthone, isopropylthioxanthone, and 2,4-dichlorothioxanthone, benzoin compounds such as benzoin and benzoin methyl ether, dimethylbenzyl ketal, and acylophosphine oxide. These can be used alone or in combination of two or more. Among these, acetophenone compounds are preferable.

The UV initiator (D) is blended in an amount of about 0.1 to 100 parts by weight based on the total weight of the oligomer (A) and the monomer (B). 10
A range of parts by weight is preferred. If the compounding ratio of the compound (D) is less than about 0.1 part by weight, the curability will decrease, while if it exceeds about 10 parts by weight, the weather resistance of the coating film will decrease, such being undesirable.

In the ink composition of the present invention, a hydroxyl group-containing acrylate copolymer resin (E) can be blended in addition to the components (A) to (D) described above. By blending the copolymer, there is an advantage that the weather resistance and adhesion of the coating are further improved. The hydroxyl group-containing acrylate
The hydroxyl group value of the copolymer resin (E) is about 5 to 3
00, preferably in the range of about 10 to 200 and having a weight average molecular weight of about 1000 to 20,000, preferably about 20.
The range of 00 to 10,000 is preferable. When the hydroxyl value is less than about 5, the adhesiveness is not improved so much, while when it exceeds about 200, the water resistance of the coating is lowered, which is not preferable. On the other hand, if the average molecular weight is less than about 1,000, the water resistance and weather resistance of the coating film will decrease, while the average molecular weight of about 200
If it exceeds 00, printing workability is deteriorated, which is not preferable.

The hydroxyl group-containing acrylate copolymer resin (E) is, for example, the above-mentioned alkyl or cycloalkyl ester and the above-mentioned hydroxyl group-containing acrylate monomer.
It is preferable to use a copolymer mainly composed of (b).
The mixing ratio of the copolymer resin (E) is about 0.5 to about 100 parts by weight of the total amount of the oligomer (A) and the monomer (B). A range of 20 parts by weight, preferably about 1-10 parts by weight is preferred. When the blending ratio of the copolymer resin (E) is less than about 0.5 parts by weight, the adhesion and weather resistance of the coating are not improved so much.
If the amount exceeds about 20 parts by weight, the hardness of the coating film decreases, which is not preferable.

In the ink composition of the present invention, a photopolymerization accelerator can be added in order to accelerate the photocrosslinking reaction by the ultraviolet polymerization initiator. Specifically, for example, tertiary amines such as triethylamine, triethanolamine, and 2-dimethylaminoethanol, alkylphosphines such as triphenylphosphine, thiols such as β-thioglycol, and the like. Can be mentioned.

In the ink composition of the present invention, in addition to the above-mentioned components, an ultraviolet absorber (benzotriazole-based, benzophenone-based, oxalic acid anilide-based, cyanoacrylate-based and derivatives thereof, oligomers, etc.
0.5 with respect to 100 parts by weight of (A) and monomer (B)
10 parts by weight), antioxidants (such as hindered amine and its derivatives, oligomer (A) and monomer (B) 1
0.5 to 10 parts by weight with respect to 00 parts by weight), a cissing inhibitor, a fluidity modifier, a pigment, an organic solvent and the like can be blended as necessary.

The ink composition of the present invention can be applied to substrates such as paper, plastics, metals, and combinations thereof.

Next, the adhesive film for marking of the present invention will be described.

The pressure-sensitive adhesive film is a pressure-sensitive adhesive film, a polyvinyl chloride film layer, a colored printing layer, and a clear ink coating layer, which are laminated in this order, and the clear ink is used. The coating layer is a clear-cured coating formed from the urethane acrylate-based UV-curable ink composition.

The pressure-sensitive adhesive layer used in the adhesive film is, for example, natural rubber, acrylic resin, ethylene /
A layer formed of a conventionally known pressure-sensitive adhesive such as vinyl acetate copolymer, polyurethane, polyester, silicone rubber, fluorine rubber, polyvinyl butyral, etc. is included. Examples of the pressure-sensitive adhesive include a tackifier, a pressure-sensitive adhesive,
Anti-aging agents, stabilizers, colorants and the like can be included.
Also, one side of the pressure-sensitive adhesive layer (the side not the polyvinyl chloride film layer) is treated with a release agent such as silicon, wax or fluororesin, a release film such as a film or a film showing the release property itself. The sex sheet can be laminated. The thickness of the film is in the range of about 10-100 microns, preferably about 20-50 microns.

The polyvinyl chloride film layer is a colored or transparent flexible film which is a base material of the colored printing layer, and facilitates the pressure bonding work and enables display of a myriad of designs by combining with the ink layer. It is what

The film is not particularly limited as long as it is usually used in the field, and a conventionally known film can be used. The film may also contain, for example, a plasticizer, a heat (light) stabilizer, a pigment and the like. The thickness of the film is in the range of about 20-500 microns, preferably about 30-100 microns.

The colored printing layer is made of, for example, polyamide resin,
By a colored printing composition prepared by blending a coloring agent and an organic solvent with a resin component such as chlorinated rubber, urethane resin, epoxy resin, acrylic resin, polyester resin, silicone resin, vinyl chloride, vinyl chloride / vinyl acetate copolymer, etc. It is formed. Of these, vinyl chloride / vinyl acetate copolymers have excellent solubility in organic solvents, and have good adhesion to polyvinyl chloride films and urethane acrylate resin-based UV-curable clear coating layers. Is preferably used. The colored printing layer can be formed by printing means such as letterpress printing, intaglio printing, lithographic printing, and stencil printing (screen printing). Among these, the stencil printing method is preferable.

The urethane acrylate resin-based UV-curable clear composition is coated by a conventionally known method, for example, a spray, roll coater, gravure coater, screen, or the like. After printing, a cured film can be formed by irradiating with ultraviolet rays. The thickness of the clear layer is a cured film thickness of about 5 to 50 microns, preferably about 10 to 10.
A range of 40 microns is preferred.

Examples of the ultraviolet ray irradiation source include a mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a carbon arc, and a metal halide. Although the irradiation amount of the ultraviolet ray is not particularly limited, it is usually 1
It is preferably in the range of 0 to 2000 mj / cm ² .

The adhesive marking film of the present invention can be attached to the surface of an object such as a building, a vehicle, a machine, an electric appliance, a road sign, etc. for display, decoration, protection or the like.

[0034]

EXAMPLES The present invention will be described in more detail with reference to Examples.

Production Example of UV-Curable Ink Composition (1) Urethane acrylic oligomer (polyester polyol "phthalic anhydride / neopentyl glycol / trimethylol propane") is reacted with hexamethylene diisocyanate. Polyester polyurethane polyol obtained by reacting acrylic acid with about 2 in one molecule
70 parts by weight of acryloyl group, and a weight average molecular weight of about 8,000 oligomer having a hydroxyl value of about 20, 20 parts by weight of acryloylmorpholine, 10 parts by weight of ethyl carbyl acrylate, polyisocyanate compound (1 mol of trimethylolpropane, Reaction product of 3 mol of ε-caprolactone and 3 mol of hexamethylene diisocyanate) 5
Parts by weight, 2-methyl-1- [4- (methylthio) phenyl-1-2-morpholinepropane-1 (polymerization initiator) 5
2 parts by weight, TINUVIN 1130 (trade name, benzotriazol derivative, UV absorber manufactured by Ciba-Geigy), SANOL LS-292 (trade name, hindered amine derivative, manufactured by Ciba-Geigy, antioxidant) ) 2 parts by weight were mixed to prepare an ink composition (1).

Production Example of UV-Curable Ink Composition (2) In the above ink composition (1), urethane acrylic oligomer 35 is used as an oligomer and a monomer component.
2 parts by weight of a urethane acryl-based oligomer (a polyurethane triisocyanate obtained by reacting trimethylolpropane with hexamethylene diisocyanate)
35 parts by weight of an oligomer having an average molecular weight of about 3000 containing 3 average acryloyl groups in one molecule obtained by reacting 2 moles of hydroxyethyl acrylate, 10 parts by weight of vinylcaprolactam, acryloylmorpholine, 10
An ink composition (2) was produced in the same manner as the ink composition (1) except that 10 parts by weight of ethyl carbitol and 10 parts by weight of ethyl carbyl acrylate were used.

Production Example of UV-Curable Ink Composition (3) In the above ink composition (2), the ink composition (2)
Hydroxyl group-containing acrylate copolymer resin (styrene /
Methyl methacrylate / isobutyl methacrylate / hydroxyethyl methacrylate / methacrylic acid = 20 /
10/50/19/1, average molecular weight about 20,000, hydroxyl group about 80) same as ink composition (2) except that 10 parts by weight of 50% by weight solution diluted with 2-ethylhexyl carbitol acrylate was added. To prepare an ink composition (3).

Production Example of UV-Curable Ink Composition (4) Ink composition (1) was prepared in the same manner as ink composition (1) except that the polyisocyanate compound was not added. 4) was obtained.

Production Example of UV-Curable Ink Composition (5) Ink composition (2) produced in the same manner as in Ink Composition (2) except that the polyisocyanate compound is not added. 5) was obtained.

Production Example of UV-Curable Ink Composition (6) An ink composition (3) prepared in the same manner as the ink composition (3) except that the polyisocyanate compound is not added. 6) was obtained.

Example 1 Releasable sheet, polyisobutyl acrylate adhesive (3
0 micron), and polyvinyl chloride sheet (white, 50
Micron) is used as the base material for the adhesive film
VK911 Sumi [manufactured by Teikoku Ink Co., Ltd., black, trade name, vinyl chloride /
[Vinyl acetate copolymer] is screen-printed to form a pattern, which is then left to stand at room temperature for 2 hours and dried, and then the ultraviolet curable ink composition (1) is applied to a film thickness of 10 μm. Screen printing was carried out and ultraviolet rays were irradiated under the condition of 500 mj / cm ² to obtain the marking film of Example 1. Example 2 The marking film of Example 2 was produced in the same manner as in Example 1 except that the ultraviolet curable ink composition (1) was replaced with the ultraviolet curable ink composition (2). Got

Example 3 The procedure of Example 1 was repeated except that the ultraviolet curable ink composition (1) was replaced with the ultraviolet curable ink composition (3). -King film obtained.

Comparative Example 1 The procedure of Example 1 was repeated except that the ultraviolet curable ink composition (1) was replaced with the ultraviolet curable ink composition (4). -King film obtained.

Comparative Example 2 The procedure of Comparative Example 2 was repeated except that the ultraviolet curable ink composition (1) in Example 1 was replaced with the ultraviolet curable ink composition (5). -King film obtained.

Comparative Example 3 The procedure of Comparative Example 3 was repeated except that the ultraviolet curable ink composition (1) in Example 1 was replaced with the ultraviolet curable ink composition (6). -King film obtained.

The performance results of the marking film are shown in Table 1.

[0047]

[Table 1]

In Table 1, the finished appearance and performance were measured by the following methods.

Tensile elongation (%): The ultraviolet-curable ink composition used in the examples and comparative examples was prepared from polyvinyl chloride raw material (manufactured by Dainippon Ink and Co., Ltd. with a pressure-sensitive adhesive) so that the film thickness became 15 μm. The film was screen-printed to a film thickness of 80 μm) and irradiated with ultraviolet rays under the condition of 500 mj / cm ² to form a film. The tensile elongation of the obtained material was measured under the following test conditions. Test piece Measured using a 150 mm length × 25 mm width, a pulling speed of 300 mm / min, a measuring temperature of 25 ° C., and a Tensilon type tensile tester.

Appearance: The clear coating surface was visually observed,
The presence or absence of abnormalities such as gloss reduction, cracking, and discoloration were evaluated. A good one is one without these abnormalities.

Adhesion: A 2 mm-width cross-cut is cut into the film with a sharp knife so as to reach the polyvinyl chloride sheet from the clear film, and an adhesive cellophane tape is adhered to the film and it is rapidly peeled off. After that, the following criteria were evaluated. ◎ Each cut is thin and smooth on both sides, and there is no peeling at the intersection of the cuts and the square at a glance, ○
Indicates that there is a slight peeling at the intersection of the cuts and there is no peeling at the intersection of the cuts and the square at a glance, and the area of the defect is less than 5% of the total square area. △ indicates that there is peeling at the intersection of the cuts. , The area of the defect is 5 to 15 of the total square area.
%, The width of peeling due to cuts is wide, and the area of the defective portion exceeds 15% of the total square area. Boiling water resistance: The clear coating film after being immersed in boiling water for 1 hour was observed, and the presence or absence of abnormalities such as gloss reduction, blistering, and whitening was evaluated by comparing with those before the test. The adhesion was performed by the same method as above.

Accelerated weather resistance: QUV accelerated baculo test using an accelerated weather resistance tester manufactured by Q Panel Co. (UV irradiation 16H /
The clear coating film was observed after 60 hours at 60 ° C. and 8 hours / 50 ° C. with ice condensation, and the presence or absence of abnormalities such as gloss reduction, blistering, and discoloration was evaluated by comparing with that before the test. The adhesion was performed by the same method as above.

Cold-heat cycle property: heating (90 ° C., 2 hours)
/ Cooling (-40 ° C, 1.5 hours) / (70 ° C, 2 hours)
/ Cooling (-40 ° C, 1.5 hours) was set as one cycle, and this cycle was repeated 5 times. The appearance (cracks, peeling, discoloration, etc.) of the clear coating film after the test was evaluated in comparison with that before the test. The adhesion was performed by the same method as above.

[0054]

According to the ultraviolet curable ink composition of the present invention, a weight average molecular weight of 1000 having an average of about 2 or more (meth) acryloyl groups in one molecule and at least one urethane bond in one molecule is 1000. To 5000 urethane acrylate oligomers (A), monomers (B) having a weight average molecular weight of 85 or more and less than 1000 and having an average of about 1 or more polymerizable double bonds in one molecule (B), and aliphatic And / or an alicyclic polyisocyanate compound (C) and an ultraviolet polymerization initiator (D) are contained as essential components, and at least one of the above-mentioned oligomer (A) and monomer (B) components is Since it contains a hydroxyl group, the coating film formed from it exhibits remarkable effects such as excellent weather resistance and adhesion to the substrate.

[0055]

Claims (3)

[Claims] 1. A urethane acrylate oligomer (A) having a weight average molecular weight of 1,000 to 20,000 and having an average of about 2 or more (meth) acryloyl groups in one molecule and at least one urethane bond in one molecule. ) The weight average molecular weight having an average of one or more polymerizable double bonds in one molecule is 8
5 or more and less than 1000 monomer (B), aliphatic and / or
Alternatively, an alicyclic polyisocyanate compound (C) and an ultraviolet polymerization initiator (D) are contained as essential components, and at least one of the components of the oligomer (A) and the monomer (B) has a hydroxyl group. A urethane acrylate resin-based UV-curable ink composition, which comprises: 2. The urethane acrylate resin-based UV curable ink according to claim 1, wherein the ink composition further contains a hydroxyl group-containing acrylate copolymer resin (E). Composition. 3. A pressure-sensitive adhesive film for marking, comprising a pressure-sensitive adhesive layer, a polyvinyl chloride film layer, a colored printing layer, and a clear ink coating layer, which are laminated in this order. A pressure-sensitive adhesive film for marking, which is a clear-cured film formed from the above urethane acrylate resin-based UV-curable ink composition.