JP2023021736A - Resin composition for water-repellent lens protective film and method for protecting water-repellent lens - Google Patents

Abstract

To provide a resin composition which can be uniformly coated even to an ultra water-repellent lens having high antifouling property, and enables formation of a protective film that is not peeled from the water-repellent lens upon the processing, has such adequate adhesiveness as to be easily peelable after processing, has such toughness as to prevent breakage of a cured film upon the peeling, and does not affect water-repellency of a base material after peeling.SOLUTION: A resin composition for a water-repellent lens protective film is provided, containing (A) polyfunctional (meth)acrylate having a weight average molecular weight of 250-30,000, (B) a polyfunctional thiol compound, (C) a photopolymerization initiator, and (D) a block copolymer which has a weight average molecular weight of 25,000 to 100,000 and is composed of a fluorine-based segment and a non-fluorine-based segment, wherein the resin composition for a water-repellent lens protective film includes, with respect to 100 pts.mass of the component (A), 0.5-30 pts.mass of the component (B), 0.1-25 pts.mass of the component (C), and 0.1-25 pts.mass of the component (D).SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin composition for a water-repellent lens protective film for protecting the lens surface during peripheral processing of the water-repellent lens. The present invention also relates to a method for protecting a water-repellent lens so as to hold the lens in a processing device during peripheral processing of the water-repellent lens.

The spectacle lens is processed by using a processing device so as to match the frame shape of the spectacle frame. In this processing device, a spectacle lens is held by a pair of lens chuck shafts, the lens is rotated by the rotation of the lens chuck shafts, and a processing tool such as a grindstone is pressed against the lens, thereby processing the lens into a desired shape. Machine. At that time, a jig is attached to the spectacle lens with double-sided tape, and the lens chuck shaft holds the spectacle lens via the jig.

In recent years, water-repellent lenses coated with a water-repellent/oil-repellent substance to which dirt such as water and oil are less likely to adhere have been widely used. Since the surface of these water-repellent lenses is slippery, if the same processing method is used for lenses that are not water-repellent, the adhesive strength of the double-sided tape will be insufficient, and the rotation angle of the lens relative to the rotation angle of the lens chuck axis will be reduced. There is a problem that the so-called axis misalignment occurs. A method of temporarily providing a protective film on the lens surface is known as a method of preventing this axial displacement. In this method, a double-faced tape for fixing jigs and a protective layer having good adhesion to the lens surface are formed on the lens surface, thereby preventing misalignment during lens processing. Moreover, after processing, the protective film can be easily peeled off from the lens.

The composition for forming the above protective film is required to be able to be uniformly applied to the surface of the water-repellent lens (coatability). In addition, the protective film obtained from this composition should have appropriate adhesion (adhesion) so that it does not peel off from the water-repellent lens during processing and can be easily peeled off after processing. It is also required not to affect the water repellency of the coating (non-staining property). After the protective film is formed on the lens, it may take several months before the peripheral processing is performed. Desired.

As such a composition, in Patent Document 1, an acrylic resin is used as a material for temporarily forming a protective film on the surface of a plastic spectacle lens on which an antifouling film having water and oil repellency is formed. is dissolved in an organic solvent.

In addition, Patent Document 2 describes a composition in which an acrylic oligomer, an acrylic monomer, a thiol compound and a photoinitiator are combined as a material capable of forming a protective film having an appropriate peel strength when the cured product is peeled off from the adherend. is described.

JP 2009-109611 A WO2013/073364

Recently, however, there has been an increase in the number of water-repellent treatments called super-water-repellent, in which the contact angle of water droplets on the coating surface is 150° or more. The inventions described in Document 1 and Patent Document 2 have the problem that coatability, adhesion and non-staining properties cannot be achieved at the same time.

The present invention has been made in view of the prior art described above, and its object is to enable uniform coating even on super water-repellent lenses with particularly high antifouling properties, and to provide a water-repellent lens during processing. It does not peel off from the substrate and has moderate adhesion that allows it to be easily peeled off after processing. It also has toughness so that the cured film does not break when peeled off, and does not affect the water repellency of the substrate after peeling. To provide a resin composition capable of forming a film, and a method for forming a protective film on a water-repellent lens so as to prevent misalignment of the lens during processing and to process the lens into a desired shape.

The present invention comprises (A) a polyfunctional (meth)acrylate having a weight average molecular weight of 250 to 30,000, (B) a polyfunctional thiol compound, (C) a photopolymerization initiator, and (D) a weight average molecular weight of 25,000 to 100,000 and containing a block copolymer consisting of fluorine-based segments and non-fluorine-based segments, wherein 0 parts by mass of component (B) is contained in 100 parts by mass of component (A). .5 to 30 parts by mass, 0.1 to 25 parts by mass of component (C), and 0.1 to 25 parts by mass of component (D). .

The present invention also provides a method for protecting a water-repellent lens by providing a cured film obtained by coating and curing the above resin composition for a protective film on the water-repellent lens as a protective layer.

The resin composition for a water-repellent lens protective film of the present invention has particularly high antifouling properties, and can be uniformly coated even on super-water-repellent lenses that are difficult to coat on the surface. In addition, the cured film obtained by curing the resin composition for a protective film for a water-repellent lens of the present invention has an appropriate adhesive strength to the water-repellent lens, so that it is possible to prevent misalignment of the axis during processing. can be easily removed without leaving any residue.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a test method for evaluating holding power of protective films in Examples of the present invention. FIG. 4 is a schematic diagram illustrating a method for evaluating holding power of a protective film in Examples of the present invention.

The present invention will be described in detail below. In the present invention, "(meth)acrylate" means a generic term including both acrylate and methacrylate. In the present invention, "○○ to XX", which indicates a numerical range, is a concept including its lower limit ("○○") and upper limit ("XX") unless otherwise specified. That is, it means "more than XX and less than XX" exactly.

The resin composition for a water-repellent lens protective film of the present invention is a curable resin composition containing the following components (A), (B), (C) and (D) as essential components.
<(A) component: polyfunctional (meth)acrylate>
(A) The polyfunctional (meth)acrylate is not particularly limited as long as it is a compound having a weight average molecular weight (Mw) of 250 to 30,000 and having two or more (meth)acryloyl groups in the molecule. materials can be used. In addition, (A) component may be used individually by 1 type, and may be used in combination of 2 or more types.

Preferred examples of the polyfunctional (meth)acrylate (A) include compounds represented by the following general formula (Formula 1).

In the formula, a is preferably 2-30.
R ¹ is a hydrocarbon group having 2 to 300 carbon atoms or a hydrocarbon group having 2 to 300 carbon atoms containing at least one selected from the group consisting of ether oxygen (-O-) and hydroxyl group (-OH); An isocyanurate ring or a group consisting of an isocyanurate ring and a hydrocarbon group or a hydrocarbon group having 2 to 20 carbon atoms, or a hydrocarbon group having 2 to 250 carbon atoms or an ether oxygen (-O-) and a hydroxyl group (- OH) is a hydrocarbon group having 2 to 250 carbon atoms containing at least one selected from the group consisting of: ^R2 is a hydrogen atom or a methyl group.

(A) Specific examples of polyfunctional (meth)acrylates include polyfunctional (meth)acrylate monomers such as trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate; ) Polyfunctional (meth)acrylate oligomers such as epoxy-modified (meth)acrylate obtained by reaction of acrylic acid, urethane (meth)acrylate obtained by reaction of diisocyanate compound, diol compound and hydroxyl group-containing (meth)acrylate compound, etc. is mentioned.

Among these, it is preferable to use urethane (meth)acrylate. By using a compound having a flexible urethane bond, the adhesion between the cured film and the water-repellent lens is improved, and misalignment during processing can be suppressed. In addition, the toughness of the cured film is improved, and breakage of the cured film during peeling can be suppressed.

Specific examples of urethane (meth)acrylates include UN-352 (number of functional groups: 2, Mw: 3,000), UN-333 (number of functional groups: 2, Mw: 3,000), UN-353 (number of functional groups: 2, Mw: 5,000), UN-1255 (number of functional groups: 2, Mw: 8,000), UN-6200 (number of functional groups: 2, Mw: 6,500), UN-6201 (number of functional groups: 2, Mw: 1,600), UN-9000PEP (number of functional groups: 2, Mw: 5,000), UN-9200A (number of functional groups: 2, Mw: 15,000), UN-3320HA (number of functional groups: 6, Mw: 1,500), UN-904 (number of functional groups: 10, Mw: 4,900), UN-953 (number of functional groups: 20, Mw: 14,000 to 40,000), UN-954 (number of functional groups: 6, Mw: 4,500), UN-6305 (number of functional groups: 2, Mw: 27,000), H-219 (number of functional groups: 9, Mw: 25,000 to 50,000) (all of the above are trade names, Neagari Kogyo Co., Ltd.), EBECRYL230 (number of functional groups: 2, Mw: 5,000), EBECRYL9260 (number of functional groups: 3, Mw: 1,500), EBECRYL4666 (number of functional groups: 4, Mw: 1,100) (above are all trade names, manufactured by Daicel Allnex Co., Ltd.), UX-4101 (number of functional groups: 2, Mw: 6,500), UX-6101 (number of functional groups: 2, Mw: 6,500) (all of the above product name, manufactured by Nippon Kayaku Kogyo Co., Ltd.) and the like.

(A) The polyfunctional (meth)acrylate preferably has a weight average molecular weight of 250 to 30,000, more preferably 500 to 15,000. If the weight-average molecular weight is less than 250, the adhesive strength between the cured film and the water-repellent lens is reduced. Workability is reduced when the cured film is peeled off from the water-repellent lens.

In the present specification, the weight average molecular weight is measured using a gel permeation chromatography device HLC-8220GPC manufactured by Tosoh Corporation, using TSKgel HZM-M manufactured by Tosoh Corporation as a column, using THF as an eluent, It was measured with an RI detector and calculated by polystyrene conversion.

(A) The number of (meth)acryloyl groups in the molecule of the polyfunctional (meth)acrylate (number of functional groups) is not particularly limited as long as it is 2 or more, and is, for example, 2-30. The upper limit is preferably 20 or less, more preferably 15 or less, still more preferably 10 or less, and particularly preferably 8 or less.

(A) The content of polyfunctional (meth)acrylate is preferably 70 to 97% by mass, more preferably 75 to 95% by mass, based on the total amount of components (A) to (D). When the content of component (A) is 70% by mass or more, the toughness of the cured film is improved, and breakage of the cured film during peeling is suppressed. improves. When the content is 97% by mass or less, the adhesion between the cured film and the water-repellent lens is appropriately adjusted, and the cured film can be easily peeled off.

<(B) component: polyfunctional thiol compound>
The polyfunctional thiol compound as component (B) is not particularly limited as long as it has two or more thiol groups (--SH groups) in the molecule, and known materials can be used. In addition, (B) component may be used individually by 1 type, and may be used in combination of 2 or more types.

(B) Specific examples of polyfunctional thiol compounds include trimethylolpropane tris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis (3-mercapto propionate), tetraethylene glycol bis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate) and the like.

The content of the polyfunctional thiol compound (B) is preferably 0.5 to 30 parts by mass, more preferably 1.0 to 25 parts by mass, per 100 parts by mass of the component (A). If the content of component (B) is less than 0.5 parts by mass with respect to 100 parts by mass of component (A), the adhesion between the cured film and the water-repellent lens becomes excessive, and the cured film may be peeled off. If it exceeds 30 parts by mass, the toughness of the cured film will be insufficient, and the cured film will break when peeled off, resulting in reduced workability when peeling the cured film from the water-repellent lens.

The ratio of thiol groups derived from component (B) to (meth)acryloxy groups derived from component (A) (hereinafter referred to as (B)/(A) functional group ratio) is preferably 0.05 to 5.0. , more preferably 0.10 to 3.0. When the (B)/(A) functional group ratio is less than 0.05, the adhesion between the cured film and the water-repellent lens becomes excessive, making it difficult to peel off the cured film. In addition, the toughness of the cured film becomes insufficient, and the cured film breaks when peeled off, resulting in a decrease in workability when the cured film is peeled off from the water-repellent lens.

<(C) Component: Photoinitiator>
The photopolymerization initiator that is the component (C) is not particularly limited, and known materials can be used. In addition, (C) component may be used individually by 1 type, and may be used in combination of 2 or more types.

(C) Specific examples of the photopolymerization initiator include acylphosphine oxide-based, oxime ester-based, aromatic ketone-based, quinone-based, alkylphenone-based, imidazole-based, acridine-based, and phenylglycine-based photopolymerization initiators. mentioned.

(Acylphosphine oxide photopolymerization initiator)
The acylphosphine oxide photopolymerization initiator has an acylphosphine oxide group (>P(=O)-C(=O)-group), and specific examples include (2,6-dimethoxybenzoyl)- 2,4,6-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (“IRGACURE-TPO” (manufactured by BASF)), Ethyl-2,4,6-trimethylbenzoylphenylphosphinate, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (“IRGACURE-819” (manufactured by BASF)), (2,5-dihydroxyphenyl ) diphenylphosphine oxide, (p-hydroxyphenyl)diphenylphosphine oxide, bis(p-hydroxyphenyl)phenylphosphine oxide, tris(p-hydroxyphenyl)phosphine oxide and the like.

(Oxime ester photopolymerization initiator)
The oxime ester photopolymerization initiator is a photopolymerization initiator having an oxime ester bond, and specific examples include 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime) (trade name: OXE-01, manufactured by BASF), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) (trademark Name: OXE-02, manufactured by BASF), 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime] (trade name: Quantacure-PDO, manufactured by Nippon Kayaku Co., Ltd.), etc. mentioned.

(Aromatic ketone-based photopolymerization initiator)
Specific examples of aromatic ketone-based photopolymerization initiators include benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one ("IRGACURE-651" (manufactured by BASF)), 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl)-butan-1-one ("IRGACURE-369" (manufactured by BASF)), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1- ON (“IRGACURE-907” (manufactured by BASF)) and the like.

(Quinone photopolymerization initiator)
Specific examples of quinone photopolymerization initiators include 2-ethylanthraquinone, phenanthrenequinone, 2-t-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, etc. mentioned.

(Alkylphenone photopolymerization initiator)
Specific examples of alkylphenone-based photopolymerization initiators include benzoin-based compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin phenyl ether, and 2,2-dimethoxy-1,2-diphenylethane-1. -one (“IRGACURE-651” (manufactured by BASF)), 1-hydroxy-cyclohexyl-phenyl-ketone (“IRGACURE-184” (manufactured by BASF)), 2-hydroxy-2-methyl-1-phenyl-propane -1-one (“IRGACURE-1173” (manufactured by BASF)), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (“IRGACURE -2959" (manufactured by BASF)), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one ("IRGACURE-127" (manufactured by BASF)) and the like.

(Imidazole-based photopolymerization initiator)
Specific examples of imidazole-based photopolymerization initiators include 2,4,5-triarylimidazole dimers, more specifically, 2-(2-chlorophenyl)-1-[2-(2-chlorophenyl 2-(o-chlorophenyl)-4,5-diphenylimidazole dimers such as )-4,5-diphenyl-1,3-diazol-2-yl]-4,5-diphenylimidazole, 2-(o- Chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenyl Examples include imidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, and the like.

Among these, it is preferable to use an aromatic ketone-based photopolymerization initiator from the viewpoint of curability when using various light sources.

The content of (C) photopolymerization initiator is preferably 0.1 to 25 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of component (A). If the content of component (C) is less than 0.1 part by mass with respect to 100 parts by mass of component (A), curing will be insufficient, resulting in reduced adhesion between the cured film and the water-repellent lens and toughness of the cured film. When the protective film is peeled off, the residue of the uncured component lowers the water repellency of the substrate. Further, when the content of component (C) exceeds 25 parts by mass with respect to 100 parts by mass of component (A), the photopolymerization initiator becomes excessive, and when the protective film is peeled off, the residue of the photopolymerization initiator causes The water repellency of the base material is lowered.

<(D) Component: Block Copolymer Consisting of Fluorinated Segment and Non-Fluorinated Segment>
Known materials can be used for the block copolymer consisting of a fluorine-based segment and a non-fluorine-based segment, which is the component (D). In addition, (D) component may be used individually by 1 type, and may be used in combination of 2 or more types.

(D) Specific examples of block copolymers composed of fluorine-based segments and non-fluorine-based segments include block copolymers of ethylenically unsaturated compounds. By using a block copolymer consisting of a fluorine-based segment and a non-fluorine-based segment, when the resin composition for forming a protective film is applied to the water-repellent lens, the component (D) is easily segregated on the surface, and the water-repellent lens becomes can improve the coatability of. In addition, by increasing the surface segregation, it becomes difficult for the component (D) to inhibit the curing reaction between the (A) polyfunctional (meth)acrylate and (B) the polyfunctional thiol compound inside the coating film, resulting in a tougher coating. An excellent cured film is obtained.

(D) Examples of commercially available block copolymers composed of fluorine-based segments and non-fluorine-based segments include MODIPER F206, MODIPER F246, and MODIPER F3636 (all trade names, manufactured by NOF Corporation).

(D) The block copolymer consisting of fluorine-based segments and non-fluorine-based segments preferably has a weight average molecular weight of 25,000 to 100,000, more preferably 30,000 to 80,000. If the weight-average molecular weight is less than 25,000, the water repellency of the substrate is lowered due to the residue of the surfactant when the protective film is peeled off. descend. The method for measuring the weight average molecular weight is the same as the method for measuring the weight average molecular weight of (A) polyfunctional (meth)acrylate.

(D) The content of the block copolymer consisting of fluorine-based segments and non-fluorine-based segments is preferably 0.1 to 25 parts by mass, more preferably 0 parts by mass, per 100 parts by mass of component (A). .5 to 20 parts by weight, particularly preferably 1.0 to 15 parts by weight. If the content of component (D) is less than 0.1 parts by mass based on 100 parts by mass of component (A), the coating properties on the water-repellent lens will be insufficient. When the is peeled off, the water repellency of the substrate is lowered due to the residue of the surfactant.

<Diluent>
The resin composition for a water-repellent lens protective film of the present invention may be diluted with an organic solvent or a reactive diluent before use in order to homogenize the reaction system and facilitate coating. Examples of such organic solvents include alcohol-based solvents, aromatic hydrocarbon-based solvents, ether-based solvents, ester-based solvents, ether-ester-based solvents, and ketone-based solvents. A monofunctional photopolymerizable monomer having a vinyl group, an acryloyl group, a methacryloyl group, or the like can be used as the reactive diluent. Among these, (meth)acrylate compounds having an acryloyl group or a methacryloyl group are preferred, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, tert -Butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-hexyl (meth)acrylate, stearyl (meth)acrylate and the like. The blending amount of the diluent may be arbitrarily adjusted within a range that does not impair the characteristics of the present invention.

The resin composition for a water-repellent lens protective film of the present invention contains coloring agents such as pigments and dyes, stabilizers, flame retardants, organic fillers, plasticizers, antioxidants, and anti-oxidants as long as the properties of the present invention are not impaired. Additives such as foaming agents, coupling agents, and rheology control agents may be added in appropriate amounts.

<Formation of protective film>
The method for forming a protective film using the resin composition for a water-repellent lens protective film of the present invention is not particularly limited, and examples thereof include methods such as dip coating, spray coating, and spin coating. The thickness of the protective film formed using the resin composition for a water-repellent lens protective film of the present invention is not particularly limited, but from the viewpoints of preventing misalignment during peripheral processing of the lens and preventing damage during processing and storage. , is preferably 10 μm or more. On the other hand, the thickness of the coating film is preferably 100 μm or less so as not to cause misalignment when specifying the lens center.

After coating the resin composition for a water-repellent lens protective film of the present invention, the composition coated on the substrate is irradiated with active energy rays such as ultraviolet rays to obtain a protective film. Examples of light sources used in the active energy ray irradiation process include UV-LEDs (ultraviolet LEDs), low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arcs, xenon arcs, gas lasers, solid-state lasers, and electron beam irradiation devices. etc.
Among them, UV-LED, which consumes significantly less power than conventional UV lamps, etc., and emits particularly little heat from the light source compared to UV lamps, is preferable. By using a certain UV-LED, it is possible to suppress the influence of UV irradiation on the water-repellent lens and suppress the occurrence of cracks in the water-repellent layer.

<(A) component: polyfunctional (meth)acrylate>
A-1: Ethylene oxide-modified bisphenol A dimethacrylate (Blenmer PDBE-200A manufactured by NOF Corporation: bifunctional, weight average molecular weight 541)
A-2: Urethane acrylate (Artresin UN-333, manufactured by Negami Kogyo Co., Ltd.: bifunctional, weight average molecular weight 3,000)
A-3: Polyether-based urethane acrylate (Artresin UN-1255, manufactured by Negami Kogyo Co., Ltd.: bifunctional, weight average molecular weight 8,000)
A-4: Polycarbonate-based urethane acrylate (Artresin UN-9200A, manufactured by Negami Kogyo Co., Ltd.: bifunctional, weight average molecular weight 15,000)
A-5: Aliphatic urethane acrylate (EBECRYL4666 manufactured by Daicel Allnex Co., Ltd.: tetrafunctional, weight average molecular weight 1,100)
A'-1: Ethylene glycol dimethacrylate (light ester EG manufactured by Kyoeisha Chemical Co., Ltd.: bifunctional, weight average molecular weight 198)
A'-2: Urethane acrylate (Shikou UV-3700B, manufactured by Mitsubishi Chemical Corporation: bifunctional, weight average molecular weight 38,000)

<(B) component: polyfunctional thiol compound>
B-1: Dipentaerythritol hexakis (3-mercaptopropionate) (manufactured by DPMP SC Organic Chemical Co., Ltd.: hexafunctional, weight average molecular weight 783)
B-2: Trimethylolpropane tris (3-mercaptopropionate) (manufactured by TMMP SC Organic Chemical Co., Ltd.: trifunctional, weight average molecular weight 399)

<(C) Component: Photoinitiator>
C-1: 2,2-dimethoxy-2-phenylacetophenone (OMNIRAD651 manufactured by IGM)

<(D) Component: Block Copolymer Consisting of Fluorinated Segment and Non-Fluorinated Segment>
D-1: Fluorinated block copolymer (Modiper F206 manufactured by NOF Corporation, weight average molecular weight 38,000)
D-2: Fluorinated block copolymer (MODIPER F246 manufactured by NOF Corporation, weight average molecular weight 25,000)
D-3: Fluorinated block copolymer (MODIPER F3636 manufactured by NOF Corporation, weight average molecular weight 77,000)
D'-1: Polyether-modified silicone oil (DOWSIL L-7001 Dow Toray Industries, Inc.)

<Diluent>
MEK: methyl ethyl ketone IPAC: isopropyl acetate BA: butyl acrylate

The components (A) to (D) and the diluent are added to the mixing container at the compounding ratios shown in Tables 1 to 3, and stirred until uniform using a three-one motor at room temperature (23 ° C.) under UV protection. , a sample of a resin composition for a water-repellent lens protective film was obtained. The obtained resin compositions for water-repellent lens protective films of Examples and Comparative Examples were evaluated for coatability, adhesion (holding power, peelability, toughness) and non-staining properties as follows. The results are shown in Tables 1-3.

[Formation of protective film on superhydrophobic lens]
For the evaluation, a plastic lens (diameter 75 mm) provided with a superhydrophobic layer having a pure water contact angle of 150° or more was used. This super water-repellent lens was coated with the resin compositions for a water-repellent lens protective film of Examples and Comparative Examples by a dip coating method so that the film thickness after curing was 20 μm. After coating, it is allowed to stand for 10 minutes at room temperature (23 ° C.) in a space where ultraviolet rays are cut off, and dried using an LED ultraviolet irradiation device (Unijet E110IIHD-395 manufactured by Ushio Inc.) so that the illuminance is 500 mW / cm ² . The distance to the lens was adjusted to irradiate one side at a time. The contact angle of the superhydrophobic lens was calculated from the angle formed by the lens and the droplet when a droplet of 1 μL of pure water was brought into contact with the surface of the objective lens.

[Evaluation of coatability]
The superhydrophobic lens was coated with the resin composition for a water-repellent lens protective film by the above-described dip coating method and cured. When cissing was observed, the maximum width of the uncoated portion from the edge of the lens was measured as the size of cissing and evaluated as follows. As regards the coatability, the size of repellency of 10 mm or less was regarded as acceptable.
A: No cissing.
◯: The portion not coated from the edge is 5 mm or less.
Δ: The portion not coated from the edge is greater than 5 mm and 10 mm or less.
x: The part which cannot be coated from the edge is larger than 10 mm.

[Holding power evaluation]
As an evaluation of axial misalignment during peripheral processing of the lens, the holding power of the protective film formed on the superhydrophobic lens was evaluated. The holding power evaluation was performed by changing the load according to JIS-Z0237. An adhesive tape (CT405AP-24 manufactured by Nichiban Co., Ltd.) with a width of 24 mm and a length of 130 mm is attached to the center of a super water-repellent lens with a protective film formed on it that has been stored for 3 months under an environment of temperature: 23°C and relative humidity: 50% ( See Figure 1). At this time, mark with a permanent marker so that the adhesive tape overlaps with the center of the concave portion of the lens. A load of 14.7 N was applied to the end of the adhesive tape opposite to the end attached to the lens, and after 10 minutes, the distance by which the marks on the convex and concave surfaces were displaced was measured (see FIG. 2). The obtained measurement results were evaluated as follows. A holding force measurement result of 2.0 mm or less was regarded as acceptable.
A: The holding force measurement result is 0.0 mm.
○: The holding force measurement result is greater than 0.0 mm and 0.5 mm or less.
Δ: The holding force measurement result is greater than 0.5 mm and 2.0 mm or less.
x: The holding force measurement result is larger than 2.0 mm.

[Peelability]
An adhesive tape (CT405AP-24 manufactured by Nichiban Co., Ltd.) was affixed to the end of a super water-repellent lens with a protective film formed thereon, which had been stored for 3 months under an environment of temperature: 23°C and relative humidity: 50%, and then the tape was peeled off by hand. bottom. The adhesion and peeling of the adhesive tape were repeated at the same position, and the number of peelings of the tape required until the protective film was peeled off was confirmed and evaluated as follows. For peelability, ◯ or Δ was regarded as acceptable.
◯: The protective film can be peeled off by one tape peeling.
Δ: The protective film can be peeled off by tape peeling 2 to 5 times.
x: The protective film cannot be peeled off even if the tape is peeled off 5 times or more.

[Toughness]
An adhesive tape (CT405AP-24 manufactured by Nichiban Co., Ltd.) was affixed to the end of a super water-repellent lens with a protective film formed thereon, which had been stored for 3 months under an environment of temperature: 23°C and relative humidity: 50%, and then the tape was peeled off by hand. bottom. The shape of the peeled protective film was confirmed and evaluated as follows. For the toughness, ◯ or △ was regarded as a pass.
O: No cracks in the protective film.
Δ: The protective film has cracks of less than 30 mm.
x: The protective film was broken, and the protective film could not be peeled off by one tape peeling.

[Non-staining]
Temperature: 23 ° C., Relative humidity: 50% After peeling off the protective film from the protective film-formed super water-repellent lens stored for 3 months, the lens was applied with an oil-based marker (marker ink (black) manufactured by Teranishi Kagaku Kogyo Co., Ltd.). When a line was drawn on the lens with , repelling of the ink was observed and evaluated as follows. Although the lens surface before the protective film is formed repels oil-based marker ink, the water repellency decreases if contaminants remain on the lens surface. For the non-staining property, ◯ or △ was regarded as acceptable.
◯: The ink drawn with a straight line becomes dot-like.
Δ: The ink drawn with a straight line becomes a thin line.
x: No cissing is observed in ink drawn in a straight line.

From the results in Tables 1 and 2, all of the resin compositions of Examples 1 to 19 had good coatability for super water-repellent lenses. In addition, the protective films obtained by curing the resin compositions of Examples 1 to 19 had moderate adhesion to the superhydrophobic lens even after being stored for 3 months in an environment at a temperature of 23°C and a relative humidity of 50%. It had a high level of holding power, peelability and toughness. Furthermore, the decrease in water repellency of the superhydrophobic lens after peeling off the protective film was suppressed, and the non-staining property was also excellent.

On the other hand, from the results in Table 3, in Comparative Examples 1 and 2, the weight-average molecular weight of the component (A) was too small or too large, so that the resulting protective film had poor holding power or toughness for the superhydrophobic lens. was lacking. In Comparative Examples 3 and 4, the content of the component (B) was too little or too much, so that the resulting protective film lacked releasability from the superhydrophobic lens or lacked toughness. In Comparative Example 5, since the content of component (C) was too small, the obtained protective film lacked holding power, toughness, and non-staining properties for superhydrophobic lenses. In Comparative Example 6, since the content of the component (C) was excessive, the non-staining property of the obtained protective film was insufficient. In Comparative Examples 7, 9, and 10, the content of the component (D) was too small, the silicone-based surfactant was used as the component (D), or the component (D) was not contained. The coatability was insufficient. In Comparative Example 8, since the content of the component (D) was excessive, the non-staining property of the obtained protective film was insufficient.

Claims (2)

A resin composition characterized by containing the following components (A) to (D),
Per 100 parts by mass of component (A), 0.5 to 30 parts by mass of component (B), 0.1 to 25 parts by mass of component (C), and 0.1 to 25 parts by mass of component (D) A resin composition for a water-repellent lens protective film, comprising:
(A) component: polyfunctional (meth) acrylate having a weight average molecular weight of 250 to 30,000 (B) component: polyfunctional thiol compound (C) component: photopolymerization initiator (D) component: weight average molecular weight of 25 ,000 to 100,000 and a block copolymer consisting of a fluorine-based segment and a non-fluorine-based segment A method for protecting a water-repellent lens by providing a protective film formed by coating and curing the resin composition for a water-repellent lens protective film according to claim 1 on the water-repellent lens.

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