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JP-2026075749-A - Active energy ray curable composition, cured coating film, and hard coat film

JP2026075749AJP 2026075749 AJP2026075749 AJP 2026075749AJP-2026075749-A

Abstract

[Problem] To provide an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film. [Solution] An active energy ray curable composition comprising: (A) Component: inorganic fine particles; (B) Component: polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and a polymer Tg of 0°C or less when homopolymerized; (C) Component: polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains, wherein the content of oxyethylene groups in the solid content of the active energy ray curable composition is 14 to 30% by mass. [Selected Figure] None

Inventors

  • 長野 尭
  • 西田 卓哉
  • 奥村 彰朗

Assignees

  • ＤＩＣ株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (7)

  1. (A) Component: Inorganic fine particles (B) Component: Polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and the glass transition temperature (Tg) of the polymer when homopolymerized is 0°C or less (C) Component: Polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains, comprising an active energy ray curable composition, The content of oxyethylene groups in the solid content of the active energy ray curable composition is 14 to 30% by mass. Active energy ray curable composition
  2. The active energy ray curable composition according to claim 1, further comprising a polyfunctional (meth)acrylate having a (meth)acryloyl group concentration of 7.0 mmol/g or more, wherein the content of component (D) in the solid content of the active energy ray curable resin composition is 0.5 to 10% by mass.
  3. The active energy ray curable composition according to claim 1, wherein the (C) component is a compound represented by the following formula (3), or a compound having a branched structure in the polysiloxane skeleton obtained by the condensation of siloxane moieties of compounds represented by the following formula (3). (In formula (3), each R7 independently represents a hydrogen atom, an alkyl group, or a phenyl group; each R8 independently represents a hydrogen atom or a (meth)acryloyl group, and at least two of the n R8s are (meth)acryloyl groups; and each Q1 independently represents an optionally substituted alkylene group, an optionally substituted alkenylene group, or an optionally substituted phenylene group. n represents an integer of 2 or more.)
  4. The active energy ray curable composition according to claim 1 for forming a hard coat film for flexible displays.
  5. A cured coating film which is a cured reaction product of an active energy ray curable composition according to any one of claims 1 to 4.
  6. A hard coat film comprising a cured coating film and a substrate as described in claim 5, wherein the thickness of the cured coating film is 20 to 100 μm.
  7. The hard coat film according to claim 6, wherein the Martens hardness calculated by the nanoindation method based on ISO 14577 under the following measurement conditions (1) and (2) is 100 N/ mm² to 300 N/ mm² , and the indentation recovery rate calculated by the following formula (1) using the work of plastic deformation (Wplast) and work of elastic deformation (Welast) obtained from the load variation curve obtained by the nanoindation method is more than 75%. Measurement conditions (1) Measurement environment: temperature 23℃, humidity 50% Measurement conditions (2) Measurement program: A Vickers indenter is used to apply a load to the surface of the hard coat film, gradually increasing the load at a rate of 1 mN/5 seconds. After reaching 1 mN, the load is held for 2 seconds, and then the load is removed while decreasing the load at a rate of 1 mN/5 seconds. Calculation formula (1): Indentation recovery rate (%) = [West / (Wplast + West)] × 100

Description

This invention relates to an active energy ray-curable composition, a cured coating film, and a hard coat film. With the rapid development of various display devices (liquid crystal displays, plasma displays, etc.), various projector devices (OHPs (overhead projectors), liquid crystal projectors, etc.), optical fiber communication devices (optical waveguides, optical amplifiers, etc.), and imaging devices such as cameras and video cameras, there is a growing demand for optical components with new functions and higher quality. Materials for optical components require properties tailored to various applications. For example, various resin films are used on the surface of liquid crystal displays. However, because the surface of resin films is soft and has low scratch resistance, it is common practice to apply a hard coat layer to the film surface to compensate for this. Specifically, a hard coat agent consisting of an active energy ray curable composition is applied to the film surface, dried, and then cured by irradiation with active energy rays such as ultraviolet light to create a hard coat layer. Hard coat layers used in optical components require high hardness to provide scratch resistance. Generally, it is known that increasing the crosslinking density by using polyfunctional monomers can improve the hardness of the hard coat layer (see, for example, Patent Document 1). Japanese Patent Publication No. 2019-006897 The following describes in detail the active energy ray-curable composition, cured coating film, and hard coat film of the present invention. However, the description of the constituent elements described below is an example (representative example) of one embodiment of the present invention and is not limited to these contents. In the following explanation, "(meth)acryloyl" means acryloyl and/or methacryloyl. "(meth)acrylate" means acrylate and/or methacrylate. Furthermore, "(meth)acrylic" means acrylic and/or methacrylic. (Activated energy ray curable composition) The active energy ray curable composition of the present invention (hereinafter sometimes simply referred to as "the composition") contains the following components (A) to (C) as essential components. (A) Component: Inorganic fine particles (B) Component: Polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and a glass transition temperature (Tg) of the polymer when homopolymerized of 0°C or less (C) Component: Polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains Generally, when a composition forming a cured coating film contains compounds with a low Tg and high mobility, such as polyethylene glycol chains or polytetramethylene glycol chains, the recovery rate of the cured coating film improves. However, as mentioned above, there is a trade-off relationship between recovery rate and elastic modulus. To improve the elastic modulus, increasing the crosslinking density using polyfunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate or dipentaerythritol hexa(meth)acrylate improves the elastic modulus, but reduces the recovery rate. The active energy ray curable composition of the present invention selectively contains component (B), a polyfunctional (meth)acrylate that contributes to improving elastic modulus while possessing a low Tg and high mobility that contributes to improving recovery rate. Therefore, it is possible to achieve both high recovery rate and high elastic modulus in the cured coating film. Furthermore, the inventors have found that including inorganic fine particles (component (A)), which are generally used to improve elastic modulus, in the composition can suppress the decrease in recovery rate, which is in a trade-off relationship with elastic modulus. Because the active energy ray curable composition of the present invention selectively contains component (A), which contributes to improving elastic modulus while suppressing the decrease in recovery rate, it is possible to achieve both high recovery rate and high elastic modulus in the cured coating film. Furthermore, the inventors have discovered that incorporating a polyfunctional (meth)acrylate (component (C)) having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains into the composition results in excellent balance between recovery rate and elastic modulus. Because the active energy ray curable composition of the present invention selectively contains component (C), it is possible to achieve both recovery rate and elastic modulus in the cured coating film. Therefore, the present invention provides an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film. The content of oxyethylene groups ( -CH2 - CH2 -O-) in the solid content of the active energy r