JP2017167218A - Composition for producing projection film, projection film, and projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection film excellent in tear resistance, scratch resistance and optical characteristics.SOLUTION: There is provided a projection film which has a base material and a resin layer formed on the base material, where the base material is formed from a resin film having a glass transition temperature of 95°C or higher, the resin layer contains hollow particles and a resin, an average particle size of primary particles of the hollow particles is 30 nm or more and 500 nm or less, a void ratio of the hollow particles is 20 vol.% or more and 95 vol.% or less, a content of the hollow particles is 10 pts.mass or more and 150 pts.mass or less with respect to 100 pts.mass of the resin, and a thickness of the resin layer is twice or more of the average particle size of the hollow particles. The projection screen has a member and a projection film stuck to the member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a composition for producing a projection film, a projection film produced using the composition for producing a projection film, and a projection screen using the projection film.

  Projectors are used for various purposes such as personal use such as home theater, digital signage such as product advertisements, and in-house activities such as projecting data in a conference room. The projection screen of such a projector includes a transmissive screen that projects an image on the back of the projection screen and visually recognizes the transmitted light, and a reflective screen that projects the image on the front of the projection screen and visually recognizes the reflected light. There are two types. What is important for each type of screen is that the projected image can be clearly confirmed, that is, visibility. In order to improve visibility, it is necessary for transmitted light to be particularly bright in a transmissive screen.

  In recent years, in order to save space, ultra-short focus projectors in which the distance between the projector and the projection screen is shortened have been commercialized. The ultra-short focus projector differs from the conventional projector in the image projection angle. Conventional projectors project images from the front direction onto the projection screen, whereas ultra-short focus projectors place the projector close to the projection screen, so project images from an extremely oblique direction. Become. When an ultra-short focus projector is used in this way, the incident angle of the projection light with respect to the projection screen increases, so the amount of light transmitted through the screen decreases, and the projected image becomes darker than when a conventional projector is used. It will be inferior.

  In order to obtain an image with good visibility on a transmissive screen using an ultra-short focus projector, it is conceivable to employ a method of increasing the amount of light compared to a conventional projector or a method of increasing the light transmittance of a projection screen. . The present inventors have adopted a method for increasing the light transmittance of the projection screen, and have started studies for that purpose. As a result, it has been found that in order to increase the light transmittance of the projection screen, a layer containing hollow particles may be provided on the surface of the projection film used for the projection screen.

  By the way, as an example of using hollow particles for a projection film, for example, in Patent Document 1, a cyclic olefin resin and a hollow organic olefin resin having an affinity for a cyclic olefin resin and an average particle diameter of 2.0 μm or more are used. It has been proposed to use a resin composition containing. This resin composition is excellent in moldability. By using this resin composition, it is said that it is possible to provide a transmissive screen diffusion plate with improved brightness and image clarity. However, such a cyclic olefin-based resin has a low tear strength and is also susceptible to impact, so that it is difficult to handle when used in a projection film.

  Moreover, there exist patent documents 2-6 and nonpatent literature 1 and 2 as a prior art document relevant to this invention.

JP 2008-64951 A Japanese Patent No. 4046921 (Japanese Patent Laid-Open No. 2001-233611) Japanese Patent No. 4654428 (Japanese Patent Laid-Open No. 2005-263550) Japanese Patent No. 4816634 (Japanese Patent Laid-Open No. 2006-256721) Japanese Patent No. 4853662 (Japanese Patent Laid-Open No. 2008-247664) Japanese Patent No. 5194935 (Japanese Patent Laid-Open No. 2009-234848)

Masanori Fuji et al., Nagoya Institute of Technology Advanced Ceramics Research Center Annual Report, 2, 25 (2013) Hideki Sakai et al., Material Technology, 30, 147 (2012)

  In the present invention, the projection film is not easily torn during cutting or processing of the projection film before being applied to a glass substrate or the like, and even if the application is performed using a squeegee or the like, the projection film It is an object of the present invention to provide a projection film that is less likely to be scratched on its surface and that has good visibility.

  The composition for producing a projection film of the present invention is a composition for producing a projection film containing hollow particles and a polymerizable compound, and the average particle diameter of primary particles of the hollow particles is 30 nm or more and 500 nm or less. The porosity of the hollow particles is 20% by volume or more and 95% by volume or less, and the content of the hollow particles is 100 parts by mass of the solid component containing the polymerizable compound other than the hollow particles. It is 10 parts by mass or more and 150 parts by mass or less.

  The projection film of the present invention is a projection film including a base material and a resin layer formed on the base material, and the base material has a glass transition temperature of 95 ° C. or less. The resin layer includes hollow particles and a resin, the primary particles of the hollow particles have an average particle size of 30 nm or more and 500 nm or less, and the void ratio of the hollow particles is 20% by volume or more and 95%. The content of the hollow particles is 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the resin, and the thickness of the resin layer is an average particle diameter of the hollow particles. It is characterized by being twice or more.

  The projection screen of the present invention is a projection screen including a member and a projection film affixed to the member, wherein the projection film is the projection film of the present invention. To do.

  ADVANTAGE OF THE INVENTION According to this invention, the film for projection excellent in tear resistance, scratch resistance, and an optical characteristic can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of the projection screen of the present invention. FIG. 2 is a schematic diagram showing an example of a state in which an image is projected onto the projection screen of the present invention using an ultrashort focus projector.

(Composition for producing a projection film of the present invention)
The present inventors have studied various means for improving scratch resistance and optical properties in the projection film, and found that a resin layer containing hollow particles and a resin may be formed on the surface of the projection film. The composition for producing a projection film of the present invention was completed.

  That is, the composition for producing a projection film of the present invention includes hollow particles and a polymerizable compound, and the average particle diameter of primary particles of the hollow particles is 30 nm to 500 nm, and the voids of the hollow particles The rate is 20% by volume or more and 95% by volume or less, and the content of the hollow particles is 10 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the solid component containing the polymerizable compound other than the hollow particles. It is characterized by the following.

  Since the composition for producing a projection film of the present invention contains hollow particles having an average primary particle diameter of 30 nm to 500 nm and a porosity of 20 vol% to 95 vol%, A projection film having excellent scratch resistance and optical properties can be provided.

  Further, the content of the hollow particles must be set to 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the solid component containing the polymerizable compound other than the hollow particles, and 20 parts by mass or more. 120 parts by mass or less is more preferable. When the content of the hollow particles is less than 10 parts by mass, the effect of improving the light transmittance of the projection film is reduced. When the content of the hollow particles exceeds 150 parts by mass, the scratch resistance of the projection film is reduced. descend.

  Hereinafter, each component of the composition for producing a projection film of the present invention will be described in detail.

<Hollow particles>
The average particle size of the hollow particles used in the present invention needs to be 30 nm or more and 500 nm or less, and more preferably 50 nm or more and 300 nm or less. When the average particle diameter is less than 30 nm, the specific surface area of the particles is increased, and more solvent is required to disperse the particles. Therefore, the viscosity of the composition for producing a projection film decreases, and the coating film In some cases, sufficient thickness cannot be secured. On the other hand, if the average particle diameter exceeds 500 nm, the scattering of light increases, or the haze of the projection film increases and the image visibility is not improved.

  The porosity of the hollow particles needs to be 20% by volume or more and 95% by volume or less. When the porosity is less than 20% by volume, the light transmittance of the projection film is not improved, and the visibility of the image is poor. On the other hand, if the porosity exceeds 95% by volume, the shell wall of the particle becomes thin and easily broken, or the light transmittance of the projection film is not improved and the image visibility is poor.

  The average particle diameter and porosity of the hollow particles can be calculated by observing the hollow particles with a scanning electron microscope (SEM) or a transmission electron microscope (TEM). In the above observation, the hollow particles may be observed directly, or the hollow particles may be cross-sectionally processed by ion milling, and the hollow particles may be cross-sectionally processed with a microtome or the like after being embedded in a resin. May be observed. In any case, with respect to 10 or more particles of the hollow particles, the particle diameter and the shell wall thickness are measured, and the average particle diameter and the average shell wall thickness are obtained. Find the rate. Here, the particle diameter of the hollow particles refers to the size of so-called primary particles, and when the hollow particles are spherical or ellipsoidal in which the ratio of the major axis length to the minor axis length is 1 to 3.5. The maximum delivery diameter is defined as the particle diameter, and in the case of other particles, the major axis diameter is defined as the particle diameter of the particle.

Porosity (%) = [(average particle diameter−average thickness of shell wall × 2) / average particle diameter] ³ × 100 (1)

  As described above, the content of the hollow particles contained in the projection film preparation composition of the present invention is 10 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the solid component containing the polymerizable compound other than the hollow particles. The solid component excluding the polymerizable compound includes, for example, optional components such as a photopolymerization initiator, a resin polymer, a dispersant, and a tackifier. The content of the hollow particles can be measured by, for example, a thermal analysis method. That is, after the non-solid component such as a solvent is removed by heating the film-forming composition for projection, the mass of the remaining solid component is measured, and further heated to around 700 ° C. to obtain a solid component other than the hollow particles. The mass of the residue after burning is measured. Since the mass of the residue is considered to be the mass of the hollow particles, the content of the hollow particles contained in the projection film preparation composition can be determined from the mass of the residue and the mass of the solid component.

The material of the hollow particles is not limited, and both hollow inorganic particles and hollow organic particles can be used, but hollow silica particles that are hollow inorganic particles are particularly preferable. This is because the hollow silica particles have high physical strength and are excellent in dispersibility in the composition for producing a projection film. The hollow silica particles may contain other metal elements in addition to SiO ₂ as a constituent component, or may be a hydrous compound.

  The method for producing hollow silica particles having an average particle diameter of 30 nm or more and 500 nm or less is not particularly limited. For example, the hollow silica particles can be produced by a template method as described in Non-Patent Document 1 described above. More specifically, a method using the bubbles described in Non-Patent Document 2 as a template, an inorganic template method using inorganic particles described in Patent Documents 2, 3, and 4 as a template, Patent Document 5 described above, It can be produced by an organic template method using the organic particles described in 6 as a template.

  Further, the hollow silica particles may be subjected to a surface treatment in order to improve compatibility with a resin formed by polymerizing the polymerizable compound. The surface treatment may be performed, for example, by adding a silicon coupling agent to a dispersion or suspension of hollow silica particles. Although the organic functional group that modifies the surface of the hollow silica particles varies depending on the silicon coupling agent to be used, it is preferable to modify the surface with a methyl group, a phenyl group, or the like for surface treatment.

<Polymerizable compound>
Although various monomers or oligomers can be used for the polymerizable compound used in the present invention, the polymerizable compound preferably contains at least the oligomer. As the oligomer, urethane acrylate, polyether acrylate, polyester acrylate and the like can be suitably used. When the oligomer is used, the so-called film-forming property is improved and the molecular weight between cross-linking points is increased, and the warpage of the film after production, so-called curling, can be reduced as compared with the case where the monomer is used alone.

  As the monomer, a conventionally known ultraviolet curable resin monomer is preferably used. For example, polyfunctional monomers such as pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate may be used.

  The polymerizable compound contains a functional group that reacts when irradiated with radiation such as gamma rays, electron beams, and ultraviolet rays, and the functional group that reacts upon irradiation with radiation is preferably an acryl group or a methacryl group. When ultraviolet rays are used as the radiation, the composition for producing a projection film of the present invention preferably contains a photopolymerization initiator together with the polymerizable compound. Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one. 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethyl Benzoyl-diphenyl-phosphine oxide or the like can be preferably used. The addition amount of the photopolymerization initiator may be 0.1 to 10 parts by mass, preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the polymerizable compound.

  The method for producing the composition for producing a projection film of the present invention is not particularly limited. For example, the above-described components may be mixed with a solvent as necessary, and each solid component may be sufficiently dispersed. Although the said mixing method is not specifically limited, For example, it can mix using a disper, a homomixer, a ribbon mixer, a paddle mixer, a planetary mixer, a roll mill, a kneader, a ball mill, a sand mill, a high-pressure homogenizer, an ultrasonic disperser, etc.

  A conventionally known solvent may be used as the solvent. For example, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone and isophorone, esters such as methyl acetate, ethyl acetate and butyl acetate, aliphatics such as hexane and octane, and aromatics such as toluene and xylene , Alcohols such as ethylene glycol, methanol, ethanol, isopropanol, terpenes such as terpineol, dihydroterpineol, limonene, methyl glycol, isopropyl glycol, methyl propylene glycol, propyl propylene glycol, butyl propylene glycol, methyl propylene glycol acetate, dimethyl glycol A glycol ether solvent such as dimethyldiglycol may be used alone or in combination. What is necessary is just to use the amount of the said solvent required in order to give the fluidity | liquidity suitable for application | coating the said composition for film production for projection.

(Projection film of the present invention)
The projection film of the present invention includes a base material and a resin layer formed on the base material, and the base material is composed of a resin film having a glass transition temperature of 95 ° C. or less. Hollow particles and a resin, the primary particles of the hollow particles have an average particle diameter of 30 nm to 500 nm, the void ratio of the hollow particles is 20% to 95% by volume, and the hollow The content of the particles is 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the resin, and the thickness of the resin layer is twice or more the average particle diameter of the hollow particles. And

  Since the substrate of the projection film of the present invention is made of a resin film having a glass transition temperature of 95 ° C. or lower, the projection film is cut when the projection film is applied to a glass substrate or the like before cutting. It is hard to tear.

  Moreover, since the resin layer of the projection film of the present invention contains hollow particles having an average primary particle diameter of 30 nm to 500 nm and a porosity of 20 vol% to 95 vol%, A projection film excellent in scratch resistance and optical properties can be provided.

  Moreover, it is necessary to set content of the said hollow particle in the said resin layer to 10 to 150 mass parts with respect to 100 mass parts of the said resin, and 20 to 120 mass parts is more preferable. When the content of the hollow particles is less than 10 parts by mass, the effect of improving the light transmittance of the projection film is reduced. When the content of the hollow particles exceeds 150 parts by mass, the scratch resistance of the projection film is reduced. descend.

  The content of the hollow particles contained in the resin layer of the projection film of the present invention is set to 10 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the resin. It can be measured by the method. That is, the resin layer of the projection film peeled off from the substrate is heated to around 700 ° C., the mass of the residue is measured, and the mass of the hollow particles contained in the resin layer is determined from the mass of the residue. The content of the hollow particles contained in the resin layer can be determined from the mass of the hollow particles.

  Furthermore, the thickness of the resin layer needs to be at least twice the average particle diameter of the hollow particles. By making the thickness of the resin layer at least twice the average particle diameter of the hollow particles, the surface of the resin layer can be smoothed and rubbed with a squeegee or the like when the projection film is attached to a glass substrate or the like. The film surface is not scratched.

  Hereinafter, each component of the projection film of the present invention will be described in detail.

<Base material>
The base material used in the present invention may be a resin film having a glass transition temperature of 95 ° C. or lower. For example, a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, etc. can be used. From the viewpoint, a PET film is preferable. By using a resin film having a glass transition temperature of 95 ° C. or lower, the tear resistance can be improved as described above.

  The thickness of the said base material is not specifically limited, For example, it can be 10-200 micrometers.

  On the other hand, when a cyclic olefin-based resin film having a glass transition temperature exceeding 95 ° C. is used, for example, the elastic modulus is high, but the tear resistance is low.

<Resin layer>
The resin layer used in the present invention contains hollow particles and a resin, and the same hollow particles used in the above-mentioned composition for producing a projection film of the present invention can be used for the hollow particles.

  Examples of the resin that can be used include acrylic resins, polyurethane resins, polystyrene resins, polycarbonate resins, polyester resins, and polyether resins. Moreover, resin which superposed | polymerized the polymeric compound used with the composition for film production for projection of the above-mentioned this invention can also be used as said resin.

  If the thickness of the said resin layer is 2 times or more of the average particle diameter of the said hollow particle, the upper limit will not be specifically limited, For example, it can be set to 5 micrometers or less.

  The production method of the projection film of the present invention is not particularly limited. For example, a coating liquid containing the empty particles, the resin, and a solvent is prepared, the coating liquid is applied to the substrate, and dried. It can manufacture by forming the said resin layer on a base material.

  The method for applying the coating solution is not particularly limited as long as it is a coating method capable of forming a smooth coating film. For example, a gravure roll method, a micro gravure roll method, a micro gravure coater method, a slit die coat Method, comma coat method, spin method, knife method, kiss method, squeeze method, reverse roll method, dipping method, bar coat method and the like.

  Further, the projection film of the present invention is obtained by polymerizing the polymerizable compound contained in the projection film preparation composition after applying the projection film preparation composition of the present invention to the substrate. It can also be produced by forming the resin layer on the substrate. Although the method for polymerizing the polymerizable compound is not particularly limited, a method of irradiating the coating film with ionizing radiation such as ultraviolet rays can be used.

  As the ionizing radiation, for example, ultraviolet rays, electron beams, β rays, and the like can be used, but ultraviolet rays are frequently used because they can be easily used. As the ultraviolet light source, a high-pressure mercury lamp, a metal halide lamp, an ultraviolet LED lamp, or the like can be used. When ultraviolet rays are used as the ionizing radiation, it is preferable to include a photopolymerization initiator in the composition for producing a projection film as described above.

(Projection screen of the present invention)
The projection screen of the present invention comprises a member and a projection film affixed to the member, and the projection film is the projection film of the present invention. Since the projection screen of the present invention includes the projection film of the present invention, it has excellent visibility.

  The projection screen of the present invention can be used as both a transmissive screen and a reflective screen, but is particularly excellent in visibility when used as a transmissive screen.

  It is preferable that the member and the projection film are bonded together with an adhesive. Thereby, peeling of the projection film from the substrate can be prevented. Moreover, the said adhesive is not specifically limited.

  Although it does not specifically limit as said member, For example, a glass substrate, a glass sheet, a resin substrate, a resin sheet etc. can be used.

  The resin layer of the projection film is preferably disposed on the outermost layer. Thereby, the visibility of a screen can be improved more.

  The method for producing the projection screen of the present invention is not particularly limited. For example, the projection film may be bonded to the member with an adhesive or the like.

  Next, the projection screen of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the projection screen of the present invention. In FIG. 1, a projection screen 10 of the present invention includes a projection film 11 and a glass substrate 12, and the projection film 11 is bonded onto the glass substrate 12 via an adhesive (not shown). ing. The projection film includes a PET film 11a and a resin layer 11b disposed on the PET film 11a. The resin layer 11b is formed of hollow particles and a resin, and is disposed on the outermost layer of the projection screen.

  FIG. 2 is a schematic diagram showing an example of a state in which an image is projected by an ultra-short focus projector using the projection screen shown in FIG. 1 as a transmissive screen. In FIG. 2, the projection screen 10 is arranged with the projection film 11 side facing the ultrashort focus projector 13 side. In FIG. 2, the projection light from the ultra-short focus projector 13 is projected to the projection direction 13a side, and the viewer of the image visually recognizes from the viewing direction 14 side. In FIG. 2, the projection film 11 is composed of a PET film 11 a and a resin layer 11 b disposed on the PET film 11 a as in FIG. 1, and is attached to the glass substrate 12.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples. In the following examples, “part” means “part by mass”.

Example 1
<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (urethane acrylate: Nippon Kayaku Co., Ltd., trade name “KAYARAD DPHA-40H”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio) -phenyl ] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 1379 parts

Next, the following component (4) is blended into the above mixed solution, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water, and finally filtered through a filter having a pore size of 1 μm. Liquid 1 was obtained.
(4) Methyl isobutyl ketone solution of hollow silica particles (manufactured by JGC Catalysts & Chemicals, trade name “Thruria”, solid content concentration: 25 mass%): 100 parts

<Production of projection film>
On a 100 μm-thick polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc., trade name “Lumirror”, glass transition temperature: 70 ° C.), the coating solution 1 was coated with a coating thickness of 0. 0 using a bar coater. It apply | coated and dried so that it might become 15 micrometers. Next, ultraviolet rays are irradiated using a high pressure mercury lamp so that the integrated light quantity is 250 mJ / cm ² , the coating film is cured, and a resin layer is formed on the PET film to produce a projection film 1. did.

(Example 2)
<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 155 parts

Next, the following component (4) is blended into the above mixed solution, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water, and finally filtered through a filter having a pore size of 1 μm. Liquid 2 was obtained.
(4) Methyl isobutyl ketone solution of hollow silica particles (manufactured by JGC Catalysts & Chemicals, trade name “Thruria”, solid content concentration: 25 mass%): 300 parts

  A projection film 2 was produced in the same manner as in Example 1 except that the coating liquid 2 was used and the coating film thickness was 1.7 μm.

(Example 3)
<Preparation of hollow silica particles>
75 parts of polystyrene particle suspension (manufactured by Polysciences, amino group modification, average particle diameter of particles: 0.1 μm, solid content concentration: 2.5 mass%) was heated to 40 ° C., and the suspension was The following components (1) to (4) were blended with stirring, and further stirred for 30 minutes to prepare a mixed solution.
(1) Water: 155 parts (2) Isopropanol: 800 parts (3) Ammonia water (concentration: 28%): 30 parts (4) Tetraethoxysilane: 15 parts

  Subsequently, the mixture was allowed to stand at 40 ° C. for 10 hours, and then returned to room temperature. Thereafter, the produced particles were collected by centrifugation and dispersed in water. The above centrifugation, particle recovery, and water dispersion were repeated twice, and after filtration through a filter, the particles were recovered by centrifugation. Thereafter, the collected particles were dried at 100 ° C. for 5 hours, and then the obtained powder was put into a firing furnace, heated to 500 ° C. at a rate of 1 ° C./minute while airflowing, and fired at 500 ° C. for 3 hours. Furthermore, the temperature was raised to 900 ° C. at a rate of 5 ° C./minute, and after firing at 900 ° C. for 3 hours, the mixture was gradually cooled to room temperature to obtain hollow silica particles.

<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 290 parts

  Next, 45 parts of the hollow silica particles prepared above and 255 parts of the solvent (methyl ethyl ketone) were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended into the mixed liquid, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water, whereby a coating liquid 3 was obtained.

  A projection film 3 was produced in the same manner as in Example 1 except that the coating solution 3 was used and the coating thickness was 2.5 μm.

Example 4
<Preparation of hollow silica particles>
Using 75 parts of polystyrene particle suspension (manufactured by Polysciences, amino group modification, average particle diameter of particles: 0.2 μm, solid content concentration: 2.5 mass%), the amount of tetraethoxysilane is 7 parts. Except for the change, hollow silica particles were produced in the same manner as in Example 3.

<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 292 parts

  Next, the hollow silica particles prepared above: 7.5 parts and the solvent (methyl ethyl ketone): 42.5 parts were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended into the mixed liquid, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water to obtain a coating liquid 4.

  A projection film 4 was produced in the same manner as in Example 1 except that the coating solution 4 was used and the coating thickness was 2.8 μm.

(Example 5)
<Preparation of hollow silica particles>
Using 75 parts of polystyrene particle suspension (manufactured by Polysciences, amino group modification, average particle diameter of particles: 0.2 μm, solid content concentration: 2.5% by mass), the amount of water added to 465 parts, isopropanol The hollow silica particles were prepared in the same manner as in Example 3 except that the amount was 2400 parts, the amount of ammonia water was 90 parts, and the amount of tetraethoxysilane was 40 parts.

<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 292 parts

  Next, 15 parts of the hollow silica particles prepared above and 85 parts of the solvent (methyl ethyl ketone) were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended into the mixed solution, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water to obtain a coating solution 5.

  A projection film 5 was produced in the same manner as in Example 1 except that the coating solution 5 was used and the coating thickness was 2.4 μm.

(Comparative Example 1)
<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (urethane acrylate: Nippon Kayaku Co., Ltd., trade name “KAYARAD DPHA-40H”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio) -phenyl ] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 620 parts

Next, the following component (4) is blended into the above mixture and stirred and mixed, and then the mixture is subjected to ultrasonic dispersion treatment while cooling the vessel with water, and finally filtered through a filter having a pore size of 2 μm. Liquid 6 was obtained.
(4) Methyl ethyl ketone solution of solid silica particles (manufactured by Nissan Chemical Industries, trade name “MEK-ST-ZL”, solid concentration: 30% by mass): 83.3 parts

<Production of projection film>
The coating solution 6 is coated on a cyclic olefin-based resin film (manufactured by Nippon Zeon Co., Ltd., trade name “Zeonor film ZF14-100”, glass transition temperature: 136 ° C.) using a bar coater. Was applied to a thickness of 0.27 μm and dried. Next, the coating film is cured by irradiating ultraviolet rays so that the integrated light quantity becomes 250 mJ / cm ² using a high-pressure mercury lamp, and a resin layer is formed on the film to produce a projection film 6. did.

(Comparative Example 2)
<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 292 parts

  Next, 80 parts of hollow silica particles prepared in Example 3 and 453 parts of solvent (methyl ethyl ketone) were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended into the mixed liquid, stirred and mixed, and then subjected to ultrasonic dispersion treatment while cooling the container with water, whereby a coating liquid 7 was obtained.

  A projection film 7 was produced in the same manner as in Example 1 except that the coating liquid 7 was used and the coating thickness was 2.6 μm.

(Comparative Example 3)
<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 292 parts

  Next, 2.5 parts of hollow silica particles prepared in Example 3 and 15 parts of solvent (methyl ethyl ketone) were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended into the mixed liquid, stirred and mixed, and further subjected to ultrasonic dispersion treatment while cooling the container with water, whereby a coating liquid 8 was obtained.

  A projection film 8 was produced in the same manner as in Example 1 except that the coating liquid 8 was used and the coating thickness was 2.8 μm.

(Comparative Example 4)
<Preparation of hollow silica particles>
Using 75 parts of a polystyrene particle suspension (manufactured by Polysciences, amino group modification, average particle diameter of particles: 0.2 μm, solid content concentration: 2.5 mass%), the amount of water is 1550 parts, and isopropanol is used. The hollow silica particles were prepared in the same manner as in Example 3 except that the amount was 8000 parts, the amount of ammonia water was 300 parts, and the amount of tetraethoxysilane was 125 parts.

<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 290 parts

  Next, the hollow silica particles prepared above: 50 parts and the solvent (methyl ethyl ketone): 285 parts were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, the hollow silica particle suspension was blended with the mixed liquid, stirred and mixed, and then subjected to ultrasonic dispersion treatment while cooling the container with water to obtain a coating liquid 9.

  A projection film 9 was produced in the same manner as in Example 1 except that the coating liquid 9 was used and the coating thickness was 2.4 μm.

(Comparative Example 5)
75 parts of polystyrene particle suspension (manufactured by Polysciences, amino group modification, average particle diameter of particles: 0.5 μm, solid content concentration: 2.5 mass%) is used, and the amount of tetraethoxysilane is 6.0. Hollow silica particles were produced in the same manner as in Example 3 except that the part was changed to the part.

<Preparation of a composition for producing a projection film (coating solution)>
First, the following components (1) to (3) were placed in a stainless steel container and stirred and mixed to prepare a mixed solution.
(1) Polymerizable compound (polyfunctional acrylate: manufactured by Nippon Kayaku Co., Ltd., trade name “KAYARAD DPCA-60”): 50 parts (2) Photopolymerization initiator [2-methyl-1- [4- (methylthio)- Phenyl] -2-morpholinopropan-1-one]: 1.5 parts (3) Solvent (methyl ethyl ketone): 194 parts

  Next, the hollow silica particles prepared above: 7.5 parts and the solvent (methyl ethyl ketone): 42.5 parts were sufficiently stirred and mixed to prepare a hollow silica particle suspension. Next, after the hollow silica particle suspension was blended with the mixed solution and stirred and mixed, ultrasonic dispersion treatment was further performed while the container was cooled with water to obtain a coating solution 10.

  A projection film 10 was produced in the same manner as in Example 1 except that the coating solution 10 was used and the coating thickness was 0.78 μm.

(Comparative Example 6)
Instead of the PET film, a coating solution 1 produced in Example 1 using a cyclic olefin-based resin film (manufactured by Nippon Zeon Co., Ltd., trade name “Zeonor Film ZF14-100”, glass transition temperature: 136 ° C.). A projection film 11 was produced in the same manner as in Example 1 except that was used.

(Reference example)
Only the PET film used in Example 1 was used as the projection film. That is, the resin film is not provided on the projection film.

  Next, the following characteristics were evaluated using the film for projection produced in Examples 1-5 and Comparative Examples 1-6.

<Tear resistance>
First, the end surfaces of the projection film were held at positions where the thumbs and the index fingers contact each other so that the thumbs and index fingers of both hands pinch. Next, the projection film was torn by twisting both hands in the opposite direction. As a result, the tear resistance was judged to be good when the film was not cut, and the tear resistance was judged to be poor when the film was cut.

<Average particle diameter and porosity of hollow silica particles>
Except for reference examples, a sample obtained by processing a cross section of the produced projection film was prepared, the sample was observed with an SEM, and the primary particle diameter of 20 hollow silica particles and the thickness of the shell wall were measured to obtain an arithmetic average. By doing this, the average particle diameter of hollow silica particles and the average thickness of the shell wall were determined, and from these values, the porosity of the hollow silica particles was determined from the above formula (1).

  Subsequently, the projection films produced in Examples 1 to 5, Comparative Examples 1 to 6, and Reference Example were attached to a float glass plate having a length of 50 mm, a width of 50 mm, and a thickness of 3 mm, with the resin layer facing outside, and evaluation. A sample was used. For the attachment, a 20 μm-thick substrate-less optical adhesive tape (manufactured by Hitachi Maxell, “highly transparent substrate-less double-sided tape No. 5075”) was used. The characteristics of the evaluation samples were evaluated as follows.

<Abrasion resistance>
The projection film side of the sample for evaluation was rubbed with a squeegee three times to check for scratches. As a result, when the number of scratches was 2 or less, the scratch resistance was judged to be good, and when the number of scratches was 3 or more, the scratch resistance was judged to be poor.

<Optical characteristics>
The total light transmittance of the sample for evaluation was measured by a method corresponding to JIS K7361-1, using a turbidimeter “NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.

  The results are shown in Table 1. Table 1 also shows the content, type and coating thickness of the hollow silica particles used.

  From Table 1, in Examples 1-5, in the resin layer of the film for projection, hollow particles having an average particle diameter of 30 to 500 nm and a porosity of 20 to 95% by volume are used. Since it was 10 to 150 parts by mass with respect to 100 parts by mass of the resin, the total light transmittance of the prepared evaluation sample was 92% or more, and the projection was better in visibility than the reference example using only the base material. A film was obtained. Moreover, in Examples 1-5, since the PET film was used as the base material for the projection film, the tear resistance was good, and the coating thickness (resin layer thickness) was twice the average particle diameter of the hollow particles. As described above, the scratch resistance was good.

  On the other hand, since the comparative example 1 used the cyclic olefin resin film for the base material, the tear resistance was inferior, and since solid particles were used, the optical properties were inferior compared to Examples 1-5. Comparative Example 2 was inferior in scratch resistance because the amount of hollow particles added exceeded 150 parts by mass. In Comparative Example 3, since the addition amount of the hollow particles was less than 10 parts by mass, the optical characteristics were inferior compared with Examples 1-5. In Comparative Example 4, since the void ratio of the hollow particles was less than 20% by volume, the optical characteristics were inferior compared to Examples 1-5. In Comparative Example 5, since the average particle diameter of the hollow particles exceeded 500 nm, the optical properties were inferior, and the coating thickness was less than twice that of the hollow particles, so that the scratch resistance was inferior. In Comparative Example 6, since a cyclic olefin resin film having a glass transition temperature of more than 95 ° C. was used as the substrate of the projection film, the tear resistance was poor.

  The present invention can provide a projection film having excellent tear resistance, scratch resistance, and optical properties, can realize a projection screen with excellent visibility, and can be used as a screen for various projectors.

DESCRIPTION OF SYMBOLS 10 Projection screen 11 Projection film 11a PET film 11b Resin layer 12 Glass substrate 13 Ultra-short focus projector 13a Projection direction 14 Viewing direction

Claims (12)

A composition for producing a film for projection, comprising hollow particles and a polymerizable compound,
The average particle diameter of the primary particles of the hollow particles is 30 nm or more and 500 nm or less,
The porosity of the hollow particles is 20% by volume or more and 95% by volume or less,
The composition for producing a projection film, wherein the content of the hollow particles is 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the solid component containing the polymerizable compound other than the hollow particles. object.   The composition for producing a film for projection according to claim 1, wherein the hollow particles are hollow silica particles.   The composition for producing a projection film according to claim 1, wherein the polymerizable compound contains a polymerizable oligomer.   The composition for producing a film for projection according to claim 3, wherein the polymerizable oligomer is at least one selected from urethane acrylate, polyether acrylate, and polyester acrylate.   The composition for film production for projection of any one of Claims 1-4 which further contains a photoinitiator. A projection film comprising a substrate and a resin layer formed on the substrate,
The substrate consists of a resin film having a glass transition temperature of 95 ° C. or less,
The resin layer includes hollow particles and a resin,
The average particle diameter of the primary particles of the hollow particles is 30 nm or more and 500 nm or less,
The porosity of the hollow particles is 20% by volume or more and 95% by volume or less,
The content of the hollow particles is 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the resin.
A film for projection, wherein the resin layer has a thickness of at least twice the average particle diameter of the hollow particles.   The projection film according to claim 6, wherein the hollow particles are hollow silica particles.   The projection film according to claim 6 or 7, wherein the resin is at least one selected from a polyurethane resin, a polyether resin, and a polyester resin. A projection screen comprising a member and a projection film affixed to the member,
The projection screen according to claim 6, wherein the projection film is the projection film according to claim 6.   The projection screen according to claim 9, wherein the member and the projection film are bonded together with an adhesive.   The projection screen according to claim 9 or 10, wherein the member is at least one selected from a glass substrate, a glass sheet, a resin substrate, and a resin sheet.   The projection screen according to claim 9, wherein the resin layer of the projection film is disposed on an outermost layer.

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