HK1145042B - Hard coat film - Google Patents

Description

Hard coating film

Technical Field

The present invention relates to an ionizing radiation polymerizable resin composition for forming a hard coat layer used for forming a protective layer on the surface of a display such as CRT, LCD, PDP, FED, or organic EL, a touch panel such as a home electric appliance, or glass, and a hard coat film used as such a protective film.

Background

In recent years, plastic products have been replacing glass products from the viewpoint of processability and weight reduction, but since the surfaces of these plastic products are easily damaged, hard coating films are often used in order to impart scratch resistance.

In addition, in the conventional glass products, a plastic film is often bonded to prevent scattering, and a hard coat layer is widely formed on the surface of the film to enhance the hardness of the film surface.

The conventional hard coat film is generally formed as follows: a hard coat layer is formed by forming a thin coating film of less than about 10 μm on a substrate (for example, a triacetyl cellulose film) directly or through a primer layer of about 1 μm using a coating material containing an actinic radiation polymerizable resin such as a thermosetting resin or an ultraviolet curable resin, and then curing the coating film by applying heat or light.

However, in the conventional hard coat film, not only the hardness of the hard coat layer is insufficient, but also when the base material of the primer layer is deformed, the hard coat layer is deformed correspondingly to this, and the hardness of the hard coat film as a whole is lowered. Therefore, the conventional hard coat film is not satisfactory enough.

For example, a hard coat film formed by applying an ultraviolet curable coating material to a triacetyl cellulose film in the above thickness (less than about 10 μm) is usually at a level of 3H or less in terms of pencil hardness.

If the hardness is insufficient, the hardness of the hard coat film is increased to easily obtain a 4H pencil hardness by simply making the thickness of the hard coat layer thicker than 10 μm, but the hard coat layer is likely to be cracked or peeled off, and the problem of an increase in curl due to curing shrinkage during curing of the coating material is also caused (see patent document 1: Japanese patent application laid-open No. 2000-127281).

On the other hand, japanese patent No. 1815116 (patent document 2) discloses a coating composition in which a resin-forming component of a hard coat layer is a polyfunctional acrylate monomer, and a powdery inorganic filler such as alumina, silica, or titanium oxide and a polymerization initiator are added thereto.

Further, japanese patent No. 1416240 (patent document 3) discloses photopolymerizable resin compositions containing an inorganic filler composed of silica or alumina surface-treated with alkoxysilane or the like, but these compositions do not satisfy the surface hardness of hard coat layers required in recent years when used for hard coat layers.

In particular, in the case of a scratch having a relatively wide contact area such as a pencil hardness scratch, the resistance is improved when a filler having a high hardness such as alumina is added, and in the case of a hard scratch having a large load per unit area such as a mechanical pencil scratch, numerous cracks are generated in the scratch, and the scratch strength is rather deteriorated.

Jp 2000 a-52472 a (patent document 4) proposes a method of satisfying curling and flaw resistance by forming a hard coat layer into a double layer and adding microsilica to the first layer, but a sufficient effect cannot be obtained.

Patent document 1: japanese patent laid-open publication No. 2000-127281

Patent document 2: japanese laid-open patent publication No. 57-74369 (Japanese patent No. 1815116)

Patent document 3: japanese Kokoku publication Sho 58-500251 (Japanese patent No. 1416240)

Patent document 4: japanese patent laid-open publication No. 2000-52472

Disclosure of Invention

The invention aims to provide a resin composition capable of forming a hard coating layer with high hardness and difficult cracking and curling, and a hard coating film.

The present inventors have conducted extensive studies and, as a result, have found that when a material of a hard coat layer is a material in which a cured product after polymerization of a polyfunctional acrylic monomer, a polyfunctional oligomer or the like is hard, strength is improved but curl is also enhanced, and conversely, when a material of a hard coat layer is a material in which curl is weak, strength is reduced.

The present inventors have further studied and found that when an acrylic resin having a multi-branched structure is added in addition to an acrylic component such as a polyfunctional acrylic monomer or a polyfunctional oligomer, a hard coating film having high hardness and weak curling can be obtained.

The present invention, which has been completed based on the above findings, provides an ionizing radiation polymerizable resin composition for forming a hard coating layer, comprising:

65.0 to 95 parts by weight of an acrylic component containing a polyfunctional acrylic monomer and either or both of a polyfunctional acrylic oligomer having a main skeleton of a linear chain or a main skeleton and having 1 branch point,

0.5 to 12 parts by weight of a siloxane component containing either one or both of a siloxane monomer having an acryloyl group at the end and a siloxane oligomer having an acryloyl group at the end,

2.0 to 20.0 parts by weight of a multi-branched acrylate resin having 9 to 16 functional groups in the chemical structure and having 2 or more branch points in the main skeleton, and

0.5 to 6.0 parts by weight of silica particles.

Further, the present invention provides a hard coat film having a resin film and a hard coat layer disposed on a surface of the resin film, wherein the hard coat layer is a cured product formed by curing the following ionizing radiation polymerizable resin composition by irradiation with ionizing radiation, the ionizing radiation polymerizable resin composition comprising:

65.0 to 95.0 parts by weight of an acrylic component containing a polyfunctional acrylic monomer and either or both of a polyfunctional acrylic oligomer having a main skeleton of a linear chain or a main skeleton and having 1 branch point,

0.5 to 12.0 parts by weight of a silicone component containing either one or both of a silicone monomer having an acryloyl group at the end and a silicone oligomer having an acryloyl group at the end,

2.0 to 20.0 parts by weight of a multi-branched acrylate resin having 9 to 16 functional groups in the chemical structure and having 2 or more branch points in the main skeleton, and

0.5 to 6.0 parts by weight of silica particles.

In particular, as a preferable embodiment of the hard coat film of the present invention, a hard coat film having a film thickness of 6.0 to 12.0 μm of the hard coat layer and a hard coat film having an average particle diameter of 10 to 50nm of silica particles are provided.

The hard coat layer formed from the ionizing radiation polymerizable resin composition of the present invention or the hard coat film of the present invention exhibits excellent effects of having high surface hardness, excellent scratch resistance, and being less likely to cause curling. Further, when the hard coat layer or the hard coat film is provided on the image display surface, an image display device having a protective layer excellent in surface hardness and abrasion resistance can be provided.

Drawings

Fig. 1 is a sectional view showing an example of a hard coat film of the present invention.

Fig. 2 is a schematic diagram for explaining an example of the chemical structure of a multi-branched acrylate resin.

Fig. 3 is a schematic cross-sectional view showing a state where a hard coat film is attached to a display device.

Description of the symbols

Hard coating film

Resin film

Hard coating

Detailed Description

The ionizing radiation polymerizable resin composition of the present invention contains the following acrylic component, silicone component, multi-branched acrylate resin, silica particles, and, if necessary, additives such as a photopolymerization initiator and a sensitizer.

The polyfunctional acrylic monomer used in the acrylic component has 2 or more functional groups such as acryloyl groups. Further, the acryl group in the present invention also includes methacryl group.

Examples of the polyfunctional acrylic monomer include polyol polyacrylates such as ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate, epoxy acrylates such as di (meth) acrylate of bisphenol a diglycidyl ether and di (meth) acrylate of hexanediol diglycidyl ether, urethane acrylates obtained by reaction of a polyisocyanate with a hydroxyl group-containing acrylate such as hydroxyethyl (meth) acrylate, and the like.

The polyfunctional acrylic oligomer used in the acrylic component is, for example, a conventional oligomer such as polyester acrylate, epoxy acrylate, urethane acrylate, or polyol acrylate, and is an oligomer in which the main skeleton of the oligomer is linear (the branch point is 0) or the branch point of the main skeleton is 1.

In order to impart high hardness by the hard coat layer, a urethane oligomer is preferably used as the acrylic component. However, depending on the use of the hard coat film, high hardness (for example, pencil hardness 4H) may not be required, and in this case, the acrylic component is not particularly limited.

Fig. 2 is a schematic diagram showing the chemical structure of an example of a multi-branched acrylate resin having a main skeleton of a structure having a plurality of constant repeating structural units, the main skeleton having a multi-branched structure (hyperbranched structure) having 2 or more branch points b.

The symbol R in the figure represents a functional group, the broken line in the figure represents a bond in which the functional group R is bonded to the main skeleton, and the functional group R is bonded to the main skeleton at one point as indicated by the symbol a in the figure. That is, the functional group R is attached to one carbon atom of the main skeleton.

In fig. 2, the number of the branch points b is 8, but when the number of the branch points b is 2 or more, the structure of the main skeleton or the number of the branch points is not particularly limited. When an example of the main skeleton of a multi-branched acrylate resin is described, there is a dendrimer called a dendrimer.

More specifically, the multi-branched acrylate resin has an oligomer having 2 or more monomers bonded as repeating units as a main skeleton, and a hyperbranched oligomer having a functional group such as an acryloyl group bonded to the oligomer.

The number of functional groups in the chemical structure of the multi-branched acrylate resin is 9 to 16. If the number of functional groups is less than 9 or exceeds 16, the pencil hardness decreases or the curl increases.

The kind of the functional group is not particularly limited, but at least one of the functional groups bonded to the main skeleton is an acryloyl group.

Examples of the multi-branched acrylate resin include multifunctional acrylic oligomers having 2 or more branch points in the main skeleton, such as polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate.

Further, the polyfunctional acrylic oligomer used in the acrylic component is different from the polyfunctional acrylic oligomer used in the multi-branched acrylate resin in whether or not the main skeleton has 2 or more branch points.

The siloxane component contains either one or both of a siloxane monomer having an acryloyl group at a terminal and a siloxane oligomer having an acryloyl group at a terminal.

In the siloxane monomer and the siloxane oligomer, the main skeleton has a siloxane bond, respectively. The material having the acrylic monomer bonded to the main skeleton is a siloxane monomer, and the material having the acrylic oligomer bonded to the main skeleton is a siloxane oligomer.

The acryl group at the terminal of the siloxane monomer is an acryl group of the acrylic monomer, and the acryl group at the terminal of the siloxane oligomer is an acryl group of the acrylic oligomer.

As the acrylic monomer bonded to the main skeleton of the siloxane monomer, there is, for example, an acrylic monomer exemplified as a polyfunctional acrylic monomer of the above-mentioned acrylic component, and as the acrylic oligomer bonded to the main skeleton of the siloxane oligomer, there is, for example, an acrylic oligomer exemplified as a polyfunctional oligomer of the above-mentioned acrylic component.

The multifunctional acrylic monomer and the multifunctional acrylic oligomer used in the acrylic component and the multifunctional acrylic oligomer used in the multi-branched acrylate resin are different from the siloxane monomer and the siloxane oligomer of the siloxane component in that they do not contain a main skeleton having a siloxane bond.

Examples of the silica particles in the present invention include colloidal silica, hollow silica, and silica sol.

The average particle diameter of the silica particles is preferably 10nm or more and less than 60nm, and particularly preferably 10nm to 50 nm. When the particle diameter of the silica particles is 60nm or more, transparency, universal pen ink repellency (マジツクは, き properties), and fingerprint wipeability are deteriorated.

Further, the addition of the silica particles can roughen the surface of the hard coat layer to some extent, and hence the handling property of the hard coat film can be improved. That is, the hard coat film is usually sold in a state of being wound into a roll shape. When the hard coat film is wound in a roll shape, if the surface of the hard coat layer is too flat, the adhesion to the resin film becomes too high, and the unwinding property is deteriorated. Therefore, from the viewpoint of decoiling properties, it is also preferable to add silica particles to the hard coat layer to improve the surface roughness to some extent.

In addition to the above components, an ionizing radiation polymerization initiator is preferably added to the ionizing radiation polymerizable resin composition in order to promote polymerization of the acrylic component, the multi-branched acrylate resin, and the silicone component.

As the ionizing radiation polymerization initiator, a polymerization initiator generally used as a photopolymerization initiator can be used, and for example, any one or more photopolymerization initiators selected from the group consisting of acetophenones, benzophenones, michler's ketone, benzoyl benzoate, benzoins, α -acyloxime esters, tetramethylthiuram monosulfide, and thioxanthone can be added.

In addition to the photopolymerization initiator, a photosensitizer may be used, and if a photosensitizer is added, the polymerization speed is faster. The photosensitizer is not particularly limited, and for example, any one or more photosensitizers selected from the group consisting of n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone may be added.

The composition comprises 65 to 95 parts by weight of an acrylic component, 2.0 to 20.0 parts by weight of a multi-branched acrylate resin, 0.5 to 12.0 parts by weight of a silicone component, and 0.5 to 6.0 parts by weight of silica particles.

When the acrylic component is less than the above range, pencil hardness decreases, and when it exceeds the above range, curl increases.

If the amount of the multi-branched acrylate resin is less than the above range, the curl increases, and if the amount exceeds the above range, the pencil hardness decreases.

When the siloxane component is less than the above range, the pencil hardness decreases, and when the siloxane component exceeds the above range, the pencil hardness decreases.

When the silica particles are smaller than the above range, the warpage increases, and when the silica particles exceed the above range, the transparency is impaired.

The ionizing radiation polymerization initiator is used in an amount of preferably 0.1 to 15 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the total of the acrylate monomer and oligomer (i.e., the acrylic component), the multi-branched acrylate resin, and the silicone component.

The ionizing radiation polymerizable resin composition is used for producing a hard coating film by applying the composition to the surface of a display such as CRT, LCD, PDP, PED, or organic EL, or the surface of a touch panel of a home electric appliance, glass, or the like, and curing the composition to form a hard coating layer, or applying the composition to a resin film to form a hard coating layer.

The ionizing radiation for curing the ionizing radiation polymerizable resin composition includes radiation, γ -ray, α -ray, electron beam, ultraviolet ray, and the like, and preferably ultraviolet ray.

The thickness of the hard coat layer is preferably more than 5 μm and less than 13 μm, and particularly preferably 6.0 μm to 12.0. mu.m. When the thickness of the hard coat layer is 5 μm, the pencil hardness is less than 4H, and when it is 13 μm, the value exceeds 20mm when the curl is measured by the measurement method of the following examples, which is a hindrance.

The resin film used for the hard coat film of the present invention is not particularly limited, but a transparent resin film (transparent plastic film) is preferably used when the film is adhered to the surface of a display or a touch panel or used as a protective film for glass or the like.

The transparent plastic film is not particularly limited, and may be appropriately selected from known transparent plastic films. As specific examples, conventional films such as triacetylcellulose, polyethylene terephthalate, polycarbonate, diacetylcellulose, polyvinyl chloride, polyester, polyethylene, polypropylene, acetylcellulose butyrate, polystyrene, and the like can be used. Among them, especially triacetyl fiber and polyethylene terephthalate are preferable as a hard coat film to be pasted to an image display device or the like from the viewpoint of no optical anisotropy, in addition to being excellent in transparency.

The film thickness of the resin film is not particularly limited, but in the case of a triacetyl cellulose film, the film thickness is preferably 40 to 500 μm, and is more preferably 80 to 200 μm because the film strength is weak when it is too thin and is too hard and poor in flexibility when it is too thick.

Next, a step of forming a hard coat layer on the surface of the resin film will be described.

For example, a coating solution of a photopolymerizable resin composition is prepared by adding a dispersion of hard inorganic fine particles and a dispersion of soft fine particles, which have been surface-modified, to a solution obtained by dissolving the above acrylic component, multi-branched acrylate resin, siloxane component, and additive (photopolymerization initiator or photosensitizer) in an organic solvent such as a ketone, alcohol, or ester.

The hard inorganic fine particle dispersion having been surface-modified is, for example, a dispersion obtained by dispersing hollow silica in a solvent, and the soft fine particle dispersion is a dispersion obtained by dispersing either or both of colloidal silica and a silica sol in a solvent.

A coating layer of the photopolymerizable resin composition is formed by applying a coating liquid of the photopolymerizable resin composition on the surface of the resin film by a known film forming method such as a dip coating method, a spin coating method, a spray coating method, a roll coating method, a gravure coating method, or a wire bar coating method.

After the coating layer is dried and the solvent is removed, the coating layer is irradiated with ionizing radiation (actinic radiation).

Since the acrylic component, the multi-branched acrylate resin, and the siloxane component all have an acryloyl group in their chemical structures, irradiation with ionizing radiation causes the acryloyl group of the acrylic component, the acryloyl group of the multi-branched acrylate resin, and the acryloyl group of the siloxane component to polymerize, and the coating layer to be cured, thereby forming a hard coating layer.

Reference numeral 10 in fig. 1 denotes a hard coat film in which a hard coat layer 15 is formed on the surface of a resin film 11.

In order to improve the adhesion between the hard coat layer 15 and the resin film 11, one or both surfaces of the resin film 11 may be subjected to a surface treatment by an oxidation method, an embossing method, or the like. Examples of the oxidation method include corona discharge treatment, glow discharge treatment, chromic acid treatment (wet treatment), flame treatment, hot air treatment, ozone/ultraviolet irradiation treatment, and the like.

The hard coat film of the present invention includes a hard coat film in which 1 or more kinds of functional films are laminated at any 1 place on the surface of the hard coat layer, between the hard coat layer and the resin film, and on the surface of the resin film opposite to the surface on which the hard coat layer is disposed.

The functional film includes an antireflection film, an ultraviolet/infrared absorption layer, a wavelength selective absorption layer, an electromagnetic wave shielding layer, an antifouling layer, and the like. The hard coat film having a functional film is provided in the form of a functional film having high hardness. These functional films can be produced by coating a solution of a known material on a hard coat layer or by vacuum deposition such as sputtering or vapor deposition.

The hard coat film of the present invention is suitably used for a protective film of a display device such as a cathode ray tube display device (CRT), a liquid crystal display device (LCD), a Plasma Display Panel (PDP), a Field Emission Display (FED), or an organic EL display.

Reference numeral 2 in fig. 3 denotes a display device, the display device 2 has a display surface 3 on which characters and images are displayed, and the hard coat film 10 of the present invention is attached as a protective film on the display surface 3, for example, with a transparent adhesive 18.

Examples

< example 1>

Acrylic acid component: a polyfunctional acrylic urethane oligomer (trade name "1290K" manufactured by DAICEL chemical Co., Ltd., functional group number: 6) 38.80% by weight

Multi-branched acrylate resin: hyperbranched oligomer (trade name "CN 2302", functional group number: 16, manufactured by Sartomer Co., Ltd.) was 5.30% by weight

Siloxane component: .90.90% by weight of a siloxane oligomer (trade name "CN 990", manufactured by Sartomer Co., Ltd.)

1.50% by weight of silica particles having an average particle diameter of 30nm

.. 1.50% by weight of a photopolymerization initiator (trade name "Irgacure 184" manufactured by Ciba Specialty Chemicals)

Solvent (methyl ethyl ketone) 50% by weight

The mixed solution having the above composition was stirred with a dispersion machine for 1 hour to prepare a coating liquid.

The multi-branched acrylate resin used in example 1 has a polyester skeleton having 2 or more branch points as a main skeleton, and 16 acryloyl groups are bonded to the end of the main skeleton.

The coating solution was coated on an 80 μm triacetyl cellulose film using a wire bar, and dried in an oven at 70 ℃ for 1 minute. Then, using a high-pressure mercury lamp, 500mJ/cm in terms of cumulative light quantity²Irradiation was carried out to obtain a hard coat film of example 1 having a thickness of a hard coat layer of 8 μm.

< examples 2 and 3>

Hard coating films of examples 2 and 3 were obtained under the same conditions as in example 1 except that the number of the wire rods used for coating the coating liquid was changed so that the thickness of the hard coating layer was 6 μm and 12 μm, respectively.

< examples 4 to 11 and 19>

Hard coat films of examples 4 to 11 and 19 were produced under the same conditions as in example 1 except that coating liquids were prepared by changing the compounding ratios of the acrylic component, the multi-branched acrylate resin, the siloxane component, the silica particles, the photopolymerization initiator and the solvent to the compounding ratios shown in table 1. The compounding ratios of examples 4 to 11 and 19, the compounding ratios of examples 1 to 3, and the compounding ratios of examples 12 to 18 described below are shown in Table 1.

The compounding ratios in table 1 and table 2 below show the compounding ratios (parts by weight) of the respective components with respect to 100 parts by weight of the total amount of the acrylic component, the multi-branched acrylate resin, the silicone component, the silica particles and the photopolymerization initiator in the photopolymerizable composition coating liquid, that is, the weight%.

< examples 12 and 13>

Hard coat films of examples 12 and 13 were produced under the same conditions as in example 1 except that the average particle diameter of the silica particles was changed from 30nm to 10nm and 50 nm.

< example 14>

A hard coat film of example 14 was produced under the same conditions as in example 1 except that a hyperbranched oligomer as a hyperbranched acrylate resin was changed from 16 functional groups to 9 functional groups (trade name "CN 2301" manufactured by Sartomer corporation).

< example 15>

The hard coat film of example 15 was produced under the same conditions as in example 1 except that the material of the resin film was changed from triacetyl cellulose to polyethylene terephthalate.

< examples 16 to 18>

Hard coat films of examples 16 to 18 were produced under the same conditions as in example 1 except that the acrylic component polyfunctional acrylic urethane oligomer was changed to the trade name "CN 9006" (6 functional groups) manufactured by Sartomer K.K., the trade name "UV 1700B" (10 functional groups) manufactured by Nippon Kabushiki Kaisha, and the trade name "NTX 767" (15 functional groups) manufactured by Sartomer K.K.

< comparative examples 1 to 7>

Except for changing the compounding ratios of the acrylic component, the multi-branched acrylate resin, the silicone component, the silica particles, the photopolymerization initiator and the solvent as shown in table 2, the hard coating films of comparative examples 1 to 7 were obtained under the same conditions as in example 1. The compositions of the coating liquids used in comparative examples 1 to 7 are shown in Table 2.

[ Table 2]

Blending ratio of coating liquid and photopolymerizable composition (comparative example)

< comparative examples 8 and 9>

Hard coat films of comparative examples 8 and 9 were produced under the same conditions as in example 1, except that the number of functional groups of the multi-branched acrylate resin was changed from 16 functional groups to 8 functional groups and 18 functional groups.

The hard coat films of examples 1 to 19 and comparative examples 1 to 9 were used to carry out the following "pencil hardness measurement", "scratch resistance test", "evaluation test of curl", "transparency test", "contact angle measurement", "all-purpose pen ink repellency test" and "fingerprint wipeability test", respectively.

[ Pencil hardness measurement ]

The hard coat film was left to stand at a temperature of 25 ℃ and a relative humidity of 60% for 2 hours, and then measured by a pencil hardness evaluation method defined in JIS-K-5400 using a test pencil defined in JIS-S-6006.

[ scratch resistance test ]

After the surface of the hard coat layer of the hard coat film was wiped with steel wool #0000 for changing the load, the change was visually observed and evaluated on the following 3 grades.

A: no scratch

B: slightly scratched

C: with scratch

The load was changed to 200g, 500g, 1000g, or 2000g, and the measurement was performed.

[ evaluation test of curl ]

The hard coat film was cut into a square shape of 100mm × 100mm to obtain a sample, the sample was placed on a flat glass plate with the hard coat layer facing upward, the distances (mm) from the glass plate to the four corners of the sample were measured, and the average value thereof was taken as the curl value. The hard coat film formed in a cylindrical shape due to the large curl was excluded from the measurement.

[ transparency test ]

The light transmittance of the hard coat film was measured using a spectrophotometer ("U-4100" manufactured by Hitachi, Ltd.).

[ contact Angle measurement ]

The water contact angle of the hard coat film was measured by a measurement method defined in JIS K2396. The higher the water contact angle, the higher the stain resistance.

[ ink repellency test with Universal Pen ]

The surface of the hard coat layer of the hard coat film was scribed with an oily master pen (trade name "sharpie f" available from Sanford) and visually observed whether the ink was repelled by the master pen, and evaluated on the following 3 scales.

A: repellent, no-residue universal pen ink trace

B: slightly non-repelling and residual universal pen ink marks

C: is not exclusive

[ fingerprint removability test ]

After forming a fingerprint on the hard coat layer surface of the hard coat film, the film was wiped with a paper towel or BEMCOT (registered trademark) of ASAHI kaseifer, and the film was evaluated on the following 3 scales by visual observation for the presence or absence of residual marks.

A: is wiped off

B: slight residual mark

C: is not wiped off

The measurement results and evaluation results are shown in table 3 below.

[ Table 3]

Evaluation results

As is clear from the results of examples 1 to 3 in Table 3, the results were good when the thickness of the hard coat layer of the present invention was 6.0 to 12.0. mu.m.

From the results of example 4, example 5, comparative example 1, and comparative example 2, it is clear that the results are good when the content of the acrylic component in the photopolymerizable resin composition is 65.0 wt% to 95.0 wt%.

From the results of examples 6 and 7 and comparative examples 1 to 4, it is clear that the results are good when the content of the multi-branched acrylate in the photopolymerizable resin composition is 2.0 wt% to 20.0 wt%.

From the results of example 8, example 9, comparative example 2, comparative example 5, and comparative example 6, it is understood that the results are good when the content of the siloxane component in the photopolymerizable resin composition is 0.5 wt% to 12.0 wt%.

As is clear from examples 10, 11, 19, 2 and 7, the photopolymerizable resin composition contained silica particles in an amount of 0.5 to 6.0 wt%, and the results were good.

From examples 12 to 13, it is understood that when the silica particles contained in the hard coat layer of the present invention have a particle diameter (average particle diameter) of 10nm to 50nm, the transparency, the universal pen ink incompatibility, and the fingerprint erasability are good.

As is clear from example 1, example 14, comparative example 8, and comparative example 9, the multi-branched acrylate resin contained in the hard coat layer of the present invention has good results when the number of functional groups is 9 to 16.

As is clear from example 15, the resin film used in the present invention is not particularly limited, and is also preferable to films other than triacetyl cellulose.

In examples 1, 16 to 18 in which the number of functional groups of the acrylic component was changed in the range of 6 to 15, excellent results were obtained in all of pencil hardness, scratch resistance, curl, transparency, contact angle, universal pen ink incompatibility, and fingerprint wiping-off property.

Industrial applicability

The present invention is useful as a technique for forming a protective layer on the surface of a display such as a CRT, LCD, PDP, FED, or organic EL, or on a touch panel or glass of a home appliance.

Claims (4)

1. An ionizing radiation polymerizable resin composition for forming a hard coat layer, comprising:

65.0 to 95 parts by weight of an acrylic component containing a polyfunctional acrylic monomer and either or both of a polyfunctional acrylic oligomer having a main skeleton of a linear chain or a main skeleton and having 1 branch point,

0.5 to 12 parts by weight of a siloxane component containing either one or both of a siloxane monomer having an acryloyl group at the end and a siloxane oligomer having an acryloyl group at the end,

2.0 to 20.0 parts by weight of a multi-branched acrylate resin having 9 to 16 functional groups in the chemical structure and having 2 or more branch points in the main skeleton, and

0.5 to 6.0 parts by weight of silica particles.

2. A hard coat film having a resin film and a hard coat layer disposed on a surface of the resin film, wherein the hard coat layer is a cured product formed by curing the following ionizing radiation polymerizable resin composition by irradiation with ionizing radiation, the ionizing radiation polymerizable resin composition comprising:

65.0 to 95.0 parts by weight of an acrylic component containing a polyfunctional acrylic monomer and either or both of a polyfunctional acrylic oligomer having a main skeleton of a linear chain or a main skeleton and having 1 branch point,

0.5 to 12.0 parts by weight of a silicone component containing either one or both of a silicone monomer having an acryloyl group at the end and a silicone oligomer having an acryloyl group at the end,

2.0 to 20.0 parts by weight of a multi-branched acrylate resin having 9 to 16 functional groups in the chemical structure and having 2 or more branch points in the main skeleton, and

0.5 to 6.0 parts by weight of silica particles,

the thickness of the hard coat layer exceeds 5 μm and is less than 13 μm.

3. The hard coating film according to claim 2, wherein the film thickness of the hard coating layer is 6.0 μm to 12.0 μm.

4. The hard coating film according to claim 2 or 3, wherein the silica particles have an average particle diameter of 10nm to 50 nm.