JP2000167999A - Film having hardened film layer of radiation curable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hardened film of a low curl thick film by containing a component of a copolymerizable unsaturated double bond and/or a compound of non-copolymerizable unsaturated double bond, and a photopolymerization initiator of a specified molecular weight at the distal end of radiation curable type multi-functional (meth)acrylate. SOLUTION: A hardened film layer of a radiation curable type resin composition is provided on a film, which contains a compound of a copolymerizable unsaturated double bond and/or a compound of non-copolymerizable unsaturated double bond, and a photopolymerization initiator having a molecular weight of 250 or more. For such a photopolymerization initiator, there is given a polymer of hydroxyketone, i.e., oligo(2-hydroxy-2-methyl-1-1(1-methylvinyl)phenyl) propanone. Also, for such radiation curable (meth)acrylate, there are given epoxyacrylate, urethaneacrylate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film having a cured film of a radiation-curable resin composition, and more particularly, to abrasion of a plastic surface such as polyester, acrylic, polycarbonate and polyether sulfone. , Chemical resistance and / or heat during post-processing,
The present invention relates to a film having a cured film of a radiation-curable resin composition that generates a very small amount of gas.

[0002]

2. Description of the Related Art At present, plastics are widely used in various industries including the automobile industry, the home appliance industry, the electric and electronic industry, and the like. The reason why plastics are used in large quantities is because of their light weight, low cost, optical characteristics, and the like, in addition to their workability and transparency. However, it has drawbacks such as being softer than glass or the like and easily scratching the surface. In order to remedy these drawbacks, it is common practice to coat a surface with a hard coat agent. As the hard coat agent, a thermosetting hard coat agent such as a silicone paint, an acrylic paint, and a melamine paint is used. Among them, silicon-based hard coat agents have been used frequently because of their high hardness and excellent quality. Most high-value-added products such as glasses and lenses use this type of coating agent. However, the curing time is long, expensive and not suitable for a hard coat of a film to be processed continuously. Attempts have also been made to add a filler for preventing reflection to the silicon hard coat agent, but since the resin is a heat-curable resin, the filler agglomerates at the time of heating and a low reflectivity core within a range that does not impair transparency. At present, no product is available.

[0003] In recent years, radiation-curable acrylic hard coat agents have been developed and used. Radiation-curable hard coat agents are hardened immediately by irradiating radiation such as ultraviolet rays to form a hard film.
Since it has a high processing speed, has excellent performance such as hardness and abrasion resistance, and is inexpensive in terms of total cost, it is now the mainstream in the field of hard coating. It is particularly suitable for continuous processing of films such as polyester. As plastic films, there are polyester films, polyacrylate films, acrylic films, polycarbonate films, vinyl chloride films, polyethersulfone films, etc., and polyester films are one of the most widely used films because of their excellent characteristics. It is. This polyester film is
Widely used as a film on the surface of a whiteboard to improve the decorativeness by laminating it on a glass shatterproof film, a car light-shielding film, an electronic material such as a touch panel, or an iron plate of a housing of a home appliance such as a refrigerator. Used. In any of these applications, a hard coat is required to prevent the surface from being damaged.

In recent years, harder hard coating agents have been demanded, and materials and coating methods have been devised, such as using a material with less shrinkage and setting a thicker film. In a display such as a CRT or an LCD having a surface coated with a hard coat agent-coated film, the film surface becomes smooth, so that the display screen becomes difficult to see due to reflection, and a problem that eyes are easily tired occurs. Depending on the application, a hard coat treatment having a surface antireflection ability is required. As a method for preventing surface reflection, a method in which an inorganic filler or an organic fine particle filler is dispersed in a radiation-curable resin is coated on a film, and the surface is made uneven to prevent reflection (AG treatment); A method of providing two layers in order of a high refractive index layer and a low refractive index layer on a film, reflecting the difference in refractive index, and preventing reflection (AR processing);
Alternatively, an AG / AR processing method combining the above two methods is generally used.

[0005]

Performing the AG treatment with a radiation-curable resin is problematic in terms of the dispersion stability of the filler, but can be achieved by selecting a dispersant or a vehicle. Also, AR
Attempts have been made to coat each layer of the treatment using radiation-curable resin, but it is difficult to perform a low-refractive-index layer with radiation-curable resin. Currently, the first layer is coated. The mainstream is to perform the second layer by sputtering. Heat is applied in this sputtering process.
If heat of a certain temperature or more is applied to the first coating layer, gas is generated, which has a problem of adversely affecting a subsequent process. The present invention improves the above-mentioned drawbacks, makes it possible to apply a thick film with low curl, and furthermore, generation of gas during heat treatment is very small, and a cured film of a radiation-curable resin composition suitable for hard coat is provided. A film having the same.

[0006]

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a radiation-curable resin composition having a specific composition can solve the above-mentioned problems. The present invention has been completed. That is, the present invention
(1) Radiation-curable polyfunctional (meth) acrylate having at least two or more (meth) acryloyl groups in the molecule
(A), a compound having a copolymerizable unsaturated double bond at a terminal (B) and / or a compound having no copolymerizable unsaturated double bond (C), and photopolymerization having a molecular weight of 250 or more. A film having a cured film layer of a radiation-curable resin composition comprising a compound represented by the initiator (D); (2) the photopolymerization initiator (D) is a polymer of hydroxyketone (1) The film of (3), wherein the polymer of (3) hydroxyketone is oligo (2-hydroxy-2)
-Methyl-1- (4- (1-methylvinyl) phenyl)
The film according to (2), which is propanone,

(4) Polyfunctional (meth) acrylate (A)
Is in the range of 50 to 95 parts by weight, when the total amount of the composition is 100 parts by weight, (1) to (3).
The film according to any one of the above, (5) Compound (B)
Content, when the total weight of the composition is 100 parts by weight,
The film according to any one of (1) to (4), wherein the content of the compound (C) is in the range of 2 to 40 parts by weight,
When the total weight of the composition is 100 parts by weight, the film of any one of (1) to (5) and the content of (7) the compound (D) are in the range of 2 to 40 parts by weight. The film according to any one of (1) to (6), wherein the total weight of the product is 100 parts by weight,
(8) The film according to any one of (1) to (6), wherein the material of the film is polypropylene, polyethylene, polyester, polyacrylate, polycarbonate or polyether sulfone;

(9) Radiation-curable polyfunctional (meth) acrylate (A) having at least two or more (meth) acryloyl groups in the molecule, and a compound having a terminal copolymerizable unsaturated double bond at the terminal (B) and / or a compound (C) having no copolymerizable unsaturated double bond, and having a molecular weight of 2
(10) a hard coat agent for a film containing the compound represented by the photopolymerization initiator (D) of 50 or more, and (10) at least one layer other than the outermost layer having two or more coatings, A film, which is a cured film layer of a radiation-curable resin composition containing D), wherein the photopolymerization initiator (D) is a compound having a molecular weight of 250 or more.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polyfunctional (meth) acrylate (A) used in the present invention is a radiation-curable (meth) acrylate having at least two or more (meth) acryloyl groups in the molecule. For example, polyol polyacrylate, epoxy acrylate, polyester acrylate, urethane acrylate, polysiloxane polyacrylate and the like can be mentioned. More preferably, it has 2 to 6 (meth) acrylate groups in the molecule, and still more preferably, it has 3 to 6 (meth) acrylate groups in the molecule. Acrylate. These polyfunctional acrylates may be used alone or in combination of two or more. Component (A) is used in an amount of 50 to 95 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the total weight of the composition.
９３93 parts by weight, more preferably 70-90 parts by weight.

Examples of the polyol polyacrylate include neopentyl glycol diacrylate, 1,6 hexanediol diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, dipentane Erythritol hexaacrylate and the like. Examples of epoxy acrylate include bisphenol A
Diglycidyl ether diacrylate, neopentyl glycol diglycidyl ether diacrylate,
And diacrylates of 1,6 hexanediol diglycidyl ether.

The polyester acrylate can be obtained by esterifying a polyhydric alcohol with a polyhydric carboxylic acid and / or an anhydride thereof and an acrylic acid. The urethane acrylates include polyhydric alcohols, polyisocyanates and acrylates containing hydroxyl groups. Obtained by reacting

As the compound (B) having an unsaturated double bond at the terminal, for example, various polymers having an unsaturated double bond can be used. Examples of the group having an unsaturated double bond include a methacrylate group and a styryl group. Examples of the polymer include polymethyl methacrylate, polymethacrylate, polystyrene, polyethylene glycol, acrylonitrile-styrene copolymer, styrene-methyl methacrylate copolymer, and the like. The compound (B) having an unsaturated double bond is preferably, for example, terminal methacrylate polymethyl methacrylate, terminal styryl polymethacrylate, terminal methacrylate polystyrene, terminal methacrylate polyethylene glycol, terminal methacrylate acrylonitrile-
A polymer having an unsaturated double bond at a terminal, such as a styrene copolymer or a methacrylate styrene-methyl methacrylate copolymer, particularly a polymer having a methacrylate group or a styryl group at a terminal is preferable. The amount of the component (B) used is 2 to 40 when the total composition is 100 parts by weight.
Parts by weight, preferably 3 to 30 parts by weight, more preferably 5 to 20 parts by weight.

As the copolymerizable compound (C) having no unsaturated double bond, a polymer having no unsaturated double bond is preferable. For example, (meth) acrylic acid and its alkyl ester are used as essential components. Acrylic acid-acrylate copolymers obtained by polymerization and acrylic copolymers such as styrene-acryl copolymers obtained by copolymerizing styrene monomers with (meth) acrylic acid and / or alkyl esters thereof are used. More preferred. The average molecular weight is preferably from 5,000 to 10,000. Component (C) is used in an amount of 2 to 40 parts by weight, preferably 3 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the whole composition.

Either component (B) or component (C) may be used, but from the viewpoint of increasing the polymerization density,
The use of component (B) is preferred. Of course, both may be used in combination.

The component (D) is a photopolymerization initiator having a molecular weight of 250 or more, for example, ESACURE KIP 15
0 (manufactured by Nihon SiberHegner KK), Irgacure 907, Irgacure 651, Irgacure 369
(All manufactured by Ciba-Geigy) and Kayacure BMS (manufactured by Nippon Kayaku Co., Ltd.). Of these, polymers of high molecular weight, for example, polymers of hydroxyketones such as oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone are preferred. Methyl-1- (4- (1-methylvinyl) phenyl) propanone is represented by the following formula (1)

[0016]

Embedded image

(In the formula (1), R represents a hydrogen atom or a methyl group, and n represents a number of 2 to 3), and 204.7 ×
n is a compound having a molecular weight of ESACURE KIP
Commercially available as 150. The amount of the component (D) to be used is 1 to 10 parts by weight, preferably 2 to 8 parts by weight, more preferably 3 to 7 parts by weight, based on 100 parts by weight of the whole composition. The component (D) may be used alone or in combination with another photopolymerization initiator. Also, 2
A combination with an initiator having a molecular weight lower than 50 is also possible,
Careful attention must be paid to the molecular weight and the amount used, since heat treatment may cause gas generation.

The radiation-curable resin composition used in the present invention may contain a solvent in addition to the components (A), (B), (C) and (D). As the solvent, for example, a diluting solvent such as methyl ethyl ketone, ethyl acetate, toluene, xylene, and cyclohexanone is used. The amount of these solvents to be used is preferably 10 to 70 parts by weight, more preferably 20 to 50 parts by weight, when the total weight of the composition is 100 parts by weight.

Further, in addition to the above components, a leveling agent and an antifoaming agent can be added if necessary.

In the radiation-curable resin composition used in the present invention, the above-mentioned component (A), component (B) or / and component (C), component (D), solvent and other components are mixed in any order. Can be obtained. The resin composition used in the present invention is stable over time.

The film of the present invention is prepared by coating the above radiation-curable resin composition on a film substrate and drying the resin composition in a weight of 1 to 50 g / m2, preferably 5 to 30 g / m2.
2 (1 to 50 μm in thickness, preferably 5 to 30 μm
m), dried, and then irradiated with radiation to form a cured film. When a film having a lower refractive index than the cured film is sputtered on the cured film of the obtained film to further form a coating layer, a film having a two-layer coating film (having an antireflection ability) is obtained. Examples of the film substrate include polyester, polypropylene, polyethylene, polyacrylate, polycarbonate, and polyethersulfone. The film may be in the form of a sheet.

Examples of the method of applying the above radiation-curable resin composition include bar coater coating, air knife coating, and the like.
Gravure coating, offset printing, flexographic printing, screen printing and the like can be mentioned. At this time, the film to be used may be provided with a pattern or an easy-adhesion layer.

The radiation to be irradiated includes, for example, ultraviolet rays and electron beams. In the case of curing by ultraviolet rays, a xenon lamp, a high-pressure mercury lamp, an ultraviolet irradiation device having a metal halide lamp is used as a light source, and the light amount and the arrangement of the light source are adjusted as necessary. It is preferable to cure at a transport speed of 5 to 60 m / min with respect to one lamp having a light amount of 120 W / cm. On the other hand, when curing with an electron beam, 1
It is preferable to use an electron beam accelerator having an energy of 00 to 500 eV.

[0024]

Next, the present invention will be described more specifically with reference to preparation examples and examples, but the present invention is not limited to these examples. In addition, in a preparation example, a part means a weight part.

Formulation Example 1 40.3 parts of dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.) and epoxy acrylate (bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 187) 187 parts), 68 parts of acrylic acid, 0.13 part of methquinone, and 0.92 part of TAP (2,4,6-tris (dimethylaminomethyl) phenol).
16.1 parts of a compound reacted at 5 ° C. for about 12 hours until the acid value becomes 3 mgKOH / g or less, pentaerythritol triacrylate (KAYARA manufactured by Nippon Kayaku Co., Ltd.)
16.1 parts of DPET-30), macromonomer AN-
6S (Toagosei Co., Ltd. 50% solids toluene) 8.1
Part, oligo (2-hydroxy-2-methyl-1- (4-
(1-Methylvinyl) phenyl) propanone (ESACURE KIP15 manufactured by SiberHegner Japan KK)
0) 4.9 parts and ethyl acetate 14.5 parts were mixed to obtain a radiation-curable resin composition used in the present invention.

Formulation Example 2 40.3 parts of dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.) and epoxy acrylate (bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 187) 187 parts), 68 parts of acrylic acid, 0.13 part of methquinone, and 0.92 part of TAP (2,4,6-tris (dimethylaminomethyl) phenol).
16.1 parts of a compound reacted at 5 ° C. for about 12 hours until the acid value becomes 3 mgKOH / g or less, pentaerythritol triacrylate (KAYARA manufactured by Nippon Kayaku Co., Ltd.)
16.1 parts of DPET-30), macromonomer AN-
6S (Toagosei Co., Ltd. 50% solids toluene) 8.1
Part, oligo (2-hydroxy-2-methyl-1- (4-
(1-Methylvinyl) phenyl) propanone (ESACURE KIP15 manufactured by SiberHegner Japan KK)
0) 3.3 parts, 1.6 parts of Irgacure 184 (manufactured by Ciba Geigy) and 14.5 parts of ethyl acetate were mixed to obtain a radiation-curable resin composition used in the present invention.

Comparative Example 1 40.3 parts of dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.) and epoxy acrylate (bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 187) 187 parts), 68 parts of acrylic acid, 0.13 part of methquinone, and 0.92 part of TAP (2,4,6-tris (dimethylaminomethyl) phenol).
16.1 parts of a compound reacted at 5 ° C. for about 12 hours until the acid value becomes 3 mgKOH / g or less, pentaerythritol triacrylate (KAYARA manufactured by Nippon Kayaku Co., Ltd.)
16.1 parts of DPET-30), macromonomer AN-
6S (Toagosei Co., Ltd. 50% solids toluene) 8.1
, Irgacure 184 (manufactured by Ciba Geigy) 4.9
And 14.5 parts of ethyl acetate were mixed to obtain a radiation-curable resin composition for a comparative test.

Example 1 (1) Method for preparing a coating film The radiation-curable resin compositions obtained in the above Formulation Examples and Comparative Examples were mixed with a toluene / MEK = 1/1 diluting solvent to obtain a solid content of 50%.
% And a bar coater No. on a 188-micron polyester film (both sides are easily adhered). 7
(8 g / m2, dry) and dried in an oven at 80 ° C. for 1 minute, and then dried under a high pressure mercury lamp of 120 W / cm.
Ultraviolet rays were irradiated at a conveyor speed of 5 m / min from a distance of 0 cm to obtain a film having a cured film.

(2) Measurement of Amount of Residual Monomer Using FTIR-8200D (manufactured by Shimadzu Corporation), the infrared absorption spectrum of the obtained film having a cured film was measured. The base was corrected with the polyester film used for the substrate, and the measurement was performed. 80 of the measurement chart
Draw a baseline from 0cm-1 to 820cm-1,
The peak intensity at 810 cm-1 was read. Since 5 cm indicates an intensity of 0.1, the read length was converted to intensity. The smaller the numerical value, the smaller the residual monomer, and it can be compared as a measure of the reactivity.

(3) Confirmation of gas generation The generated gas was confirmed by thermal desorption GC / MS analysis.

(4) Measurement of Pencil Hardness The radiation-curable resin compositions obtained in the above Formulation Examples and Comparative Examples were adjusted to a solid content of 50% with a diluting solvent (ethyl acetate), and 188 micron polyester was used. A bar coater No. is applied to the film (both sides are easily adhered). Coating at 14 (14 g / m ² , dry) and 1 at 80 ° C. oven
After drying for 10 minutes, 10 cm under a high-pressure mercury lamp of 120 W / cm
UV light was irradiated twice at a conveyor speed of 10 m / min from the above distance to produce a film having a cured film. The film was measured with a pencil hardness tester (553-M, manufactured by Yasuda Seiki Seisakusho) at a load of 1 kg and an angle of 45 degrees.
It was represented by the number of a scratch-free pencil three or more times.

(5) Measurement of curl The radiation-curable resin compositions obtained in the above Formulation Examples and Comparative Examples were adjusted to a solid content of 50% with a diluting solvent (ethyl acetate), and a 50-micron polyester film was obtained. (Both coater No. has been applied) Coating at 4 (4.
6 g / m ² , dried), dried in an oven at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays from a distance of 10 cm under a high-pressure mercury lamp of 120 W / cm at a conveyor speed of 15 m / min to form a film having a cured film. Produced. When this film is cut into 10 x 15 cm and placed on a flat surface, 4
The maximum curl at the corner was measured.

Table 1 IR intensity Evolved gas Hardness Curl Formulation Example 1 0.06 Almost no large peak 3H 1.3cm Formulation Example 2 0.06 Almost no large peak 3H 1.2cm Comparative Example 0.06 3 There is a large peak 3H 2.0cm

As is evident from Table 1, the radiation-curable resin composition of the present invention has good reactivity and pencil hardness as well as the hard coat agent of the comparative example. The result was quite small. The curl was also good.

[0034]

According to the present invention, a film having a cured film of a radiation-curable resin composition having a low curl and a small amount of gas generated during heat treatment was obtained.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4F100 AH02A AH02H AK01C AK02A AK04B AK07B AK25A AK25B AK25J AK41B AK45B AK55B AL01A AL05A AL05C AT00B BA02 BA03 BA04 BA05 BA07 BA10ABAJJBCAB CAB JBCAB JBCAB JK12 JL04 YY00A 4J038 CE052 DL101 FA241 FA251 FA261 FA271 FA281 GA01 GA02 KA03 MA14 NA04 NA11 PA17 PB07 PB08 PB09 PC08

Claims (10)

[Claims] 1. A radiation-curable polyfunctional (meth) acrylate (A) having at least two or more (meth) acryloyl groups in a molecule, a compound having a copolymerizable unsaturated double bond at a terminal ( B) and / or a compound (C) having no copolymerizable unsaturated double bond and a photopolymerization initiator (D) having a molecular weight of 250 or more. A film having a cured film layer. 2. The film according to claim 1, wherein the photopolymerization initiator (D) is a polymer of hydroxyketone. 3. The polymer of hydroxyketone is oligo (2).
The film according to claim 2, which is -hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone. 4. The content of the polyfunctional (meth) acrylate (A) is 50 when the total amount of the composition is 100 parts by weight.
The film according to any one of claims 1 to 3, wherein the film content is in the range of -95 parts by weight. 5. The film according to claim 1, wherein the content of the compound (B) is in the range of 2 to 40 parts by weight based on 100 parts by weight of the total weight of the composition. 6. The film according to claim 1, wherein the content of the compound (C) is in the range of 2 to 40 parts by weight based on 100 parts by weight of the total weight of the composition. 7. The film according to claim 1, wherein the content of the compound (D) is in the range of 1 to 10 parts by weight based on 100 parts by weight of the total weight of the composition. 8. The film according to claim 1, wherein the material of the film is polypropylene, polyethylene, polyester, polyacrylate, polycarbonate or polyether sulfone. 9. A radiation-curable polyfunctional (meth) acrylate (A) having at least two (meth) acryloyl groups in a molecule, a compound having an unsaturated double bond copolymerizable at a terminal ( B) and / or a copolymerizable compound having no unsaturated double bond (C) and a photopolymerization initiator having a molecular weight of 250 or more (D), a hard coat agent for a film containing the compound represented by (D). 10. A film having two or more coating films, wherein at least one of the layers other than the outermost layer is a cured film layer of a radiation-curable resin composition containing a photopolymerization initiator (D), A film, wherein the photopolymerization initiator (D) is a compound having a molecular weight of 250 or more.