JP7246817B2 - Ultraviolet absorption adsorption film - Google Patents

Description

The present invention provides an anchor that can be attached to or removed from an adherend, has good visible light transmittance, and has sufficient adhesion between a base material and an adsorption layer, and has ultraviolet absorption ability. It relates to a layered adsorption film.

Photographs, printed matter, resin products, etc. are degraded by ultraviolet rays. Fading occurs in photographs and printed materials, and surface whitening and cracking occur in resin products. In order to prevent these deteriorations, it is conceivable to incorporate an ultraviolet absorbing agent into the product itself or to provide a resin layer having ultraviolet absorbing ability on the surface.

In addition to this, a method of attaching a protective film capable of absorbing ultraviolet rays to the surface of the product is conceivable. In this case, when the protection from ultraviolet rays becomes unnecessary, it can be easily removed from the adherend, which is very convenient.

As a film that can be easily attached to and removed from an adherend, there is an adsorption film having an adsorption layer provided on one surface of a substrate (see Patent Document 1). In order not to damage the adherend, the adsorption layer is required to adhere to the adherend reliably with a weak force when applied, and to be easily peeled off with a small peeling force when peeled off. As an adsorption layer having such a function, there is an addition reaction type silicone adsorption layer made of a silicone resin obtained by curing a silicone composition through an addition reaction (see Patent Document 2).

In addition, in order to prevent ultraviolet deterioration of adherends in adsorption films, it has hitherto been practiced to incorporate an ultraviolet absorber into the film. Patent Document 3 discloses a screen protective film having a substrate and an adhesive layer, the adhesive layer containing an acrylic copolymer and a triazine-based ultraviolet absorber, and having an ultraviolet absorbing ability. there is

When the present inventors added an ultraviolet absorber to the addition reaction type silicone resin to a level at which the ultraviolet absorption ability is excellent, the compatibility between the addition reaction type silicone resin and the ultraviolet absorber deteriorated, and the adsorption layer became cloudy. Therefore, it was not suitable as a protective film.

Furthermore, some ultraviolet absorbers act as addition reaction inhibitors in addition reaction type silicone resins, and when the silicone composition contains them to a level that allows for excellent ultraviolet absorption, the addition reaction of the silicone composition is inhibited. Insufficient curing of the silicone resin. As a result, after the adsorption film is attached to the adherend, when the adsorption film is peeled off from the adherend, a part of the adsorption layer peels off and adheres to the adherend, which is a so-called adhesive residue. It was difficult to make an adsorption layer with ultraviolet absorption ability by including it in an addition reaction type silicone resin.

JP-A-6-198785 Japanese Patent Application Laid-Open No. 2004-59800 JP 2016-130276 A

The present invention provides an anchor that can be attached to or removed from an adherend, has good visible light transmittance, and has sufficient adhesion between a base material and an adsorption layer, and has ultraviolet absorption ability. To provide an adsorption film which protects an adherend from ultraviolet deterioration by providing a layer and leaves no adhesive residue on the adsorption layer when peeled from the adherend.

As a result of intensive studies, the present inventors have found that an adsorption film having a silicone-based adsorption layer made of a silicone resin obtained by curing a silicone composition through an addition reaction on one side of a base material made of resin. , By providing an anchor layer composed of an acrylic polyol resin and an ultraviolet absorber between the substrate and the adsorption layer, it has sufficient ultraviolet absorption ability, has good visible light transmittance, and can be used with the substrate and the adsorption layer. The inventors have found that sufficient adhesion can be obtained, and have completed the present invention.

Furthermore, since the adsorption film of the present invention includes an anchor layer having ultraviolet absorption ability, the adhesiveness between the base material and the silicone adsorption layer is good. The layer does not peel off, and processing such as cutting with an ultraviolet laser is possible, and it has good processing characteristics for various processing methods.

A first invention is an adsorption film in which an anchor layer and an adsorption layer are laminated in this order on one side of a substrate, wherein the adsorption layer is formed by curing at least one silicone composition by an addition reaction, and the anchor layer An adsorption film characterized by containing 85 to 93% by weight of an acrylic polyol resin, 0.30 to 1.80 g/m ² of an ultraviolet absorber, and a coating weight of the anchor layer of 3 to 12 g/m ² . is.

A second invention is the adsorption film according to the first invention, wherein the ultraviolet absorber in the anchor layer is an ultraviolet absorber having a benzotriazole skeleton.

In a third aspect of the present invention, the adsorption layer is obtained by curing a silicone composition containing at least a vinyl group-containing polydimethylsiloxane composition, a methylhydrogensiloxane-dimethylsiloxane copolymer, and a silicone resin as the silicone composition by an addition reaction, The adsorption film according to the first or second invention, wherein the adsorption layer has a thickness of 3 to 20 μm.

A fourth invention is the adsorption film according to any one of the first to third inventions, wherein the absorption film has an ultraviolet transmittance of 1.5% or less at a wavelength of 355 nm.

The adsorption film of the present invention is an adsorption film in which a silicone-based adsorption layer made of a silicone resin obtained by curing a silicone composition through an addition reaction is provided on one surface of a substrate made of a resin. An anchor layer consisting of an acrylic polyol resin and an ultraviolet absorber is provided between the layers, which is attached to the adherend for protection from ultraviolet rays, can be easily peeled off when no longer needed, and is further punched out. It has good processing characteristics for processing and processing with an ultraviolet laser.

The adsorption film of the present invention will be described in more detail below based on its constituent elements.

(overall structure)
The adsorption film of the present invention is an adsorption film provided with a silicone-based adsorption layer comprising a silicone resin obtained by providing an anchor layer on one surface of a base material made of a resin, and curing a silicone composition thereon by an addition reaction. and the anchor layer is an adsorption film made of an acrylic polyol resin and an ultraviolet absorber.

(Base material)
Among the components of the adsorption film of the present invention, a general resin film can be used as a base material made of resin, but there are many problems such as adhesion with the anchor layer, strength as a protective film, and the price of the film as a base material. In particular, polyethylene terephthalate (PET) film can be used favorably because of its availability, punching, and processing characteristics such as ultraviolet laser.

The thickness of the substrate is preferably 12-200 μm, more preferably 25-125 μm. If the thickness of the substrate is less than 12 μm, the strength of the protective film is insufficient. If the thickness is more than 200 μm, the flexibility will be lost and the peeling from the adherend will be difficult. Moreover, the adherend may be damaged during peeling, resulting in a high price.

The surface of the substrate may be subjected to a treatment such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, flame treatment, etc., as desired.

(anchor layer)
In the present invention, an anchor layer is provided between the substrate and the adsorption layer. As the material for the anchor layer, an acrylic polyol resin is preferable in terms of adhesion between the base material and the silicone-based adsorption layer and the anchor layer, compatibility with the ultraviolet absorber, processability, and the like. By using acrylic polyol resin as the main ingredient of the anchor layer, it is possible to ensure the adhesion between the base material and the silicone-based adsorption layer. and has UV absorbability.

The coating weight of the anchor layer is preferably 3-12 g/m ² , more preferably 3-10 g/m ² . If the coating amount of the anchor layer is less than 3 g/m ² , the amount of the UV absorber that can be contained in the anchor layer is small, making it difficult to have sufficient UV absorbability. When the coating amount is more than 12 g/m ² , flexibility is lost and it becomes difficult to peel the adsorption film from the adherend. Also, the price will be higher.

Considering the suitability for cutting with an ultraviolet laser, the ultraviolet absorber contained in the anchor layer is preferably one that absorbs the ultraviolet wavelength of the laser used for processing. is preferably used because one having a benzotriazole skeleton has an absorption characteristic in the vicinity of a wavelength of 355 nm.

The UV absorber having a benzotriazole skeleton is not particularly limited, but examples include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'- Di-tertbutylphenyl)benzotriazole, 2-(2′-hydroxy-3′,5′-di-tertbutylphenyl)-5-chlorobenzotriazole, 2-(2′-hydroxy-3′-tertbutyl- 5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tertbutyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'- Di-tert-amylphenyl)-5-chlorobenzotriazole, 2-(2′-hydroxy-3′-(3″,4″,5″,6″-tetrahydrophthalimidomethyl)-5′-methylphenyl)-benzo triazole, 2-(5-chloro-2H-benzotriazol-2-yl)-6-tertbutyl-4-methylphenol, 2,2′-methylenebis(4-tertoctyl-6-benzotriazolyl)phenol, etc. is mentioned.

The content of the ultraviolet absorbent in the anchor layer is preferably in the range of 0.30 to 1.80 g/m ² . Within this range, the anchor layer can sufficiently absorb ultraviolet rays. If the content is less than 0.30 g/m ² , the UV absorbability will be low. If the content exceeds 1.80 g/m ² , the compatibility with the acrylic polyol resin constituting the anchor layer is lowered, causing problems such as precipitation of the ultraviolet absorber and white turbidity of the anchor layer. Moreover, the addition reaction of the adsorption layer made of the addition reaction type silicone resin laminated on the anchor layer is inhibited, causing insufficient curing, and the adsorption layer causes adhesive residue on the adherend.

Further, it is preferable that the UV-absorbing adsorption film of the present invention has a UV transmittance of 1.5% or less at a wavelength of 355 nm. When the transmittance is 1.5% or less, the film has sufficient ultraviolet absorbing power and is suitable for processing with an ultraviolet laser.

As the acrylic polyol resin used for the anchor layer of the present invention, for example, a polymerizable monomer having one or more hydroxyl groups in the molecule and another monomer copolymerizable therewith are copolymerized. Polymerizable monomers having a hydroxyl group include, for example, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2- Dihydroxymethylbutyl (meth)acrylate, polyhydroxyalkyl maleate, polyhydroxyalkyl fumarate and the like. Examples of monomers copolymerizable with these include (meth)acrylic acid, alkyl (C1-C12) (meth)acrylates, maleic acid, alkyl maleates, fumaric acid, alkyl fumarate, itaconic acid, , alkyl itaconate, styrene, α-methylstyrene, vinyl acetate, (meth)acrylonitrile, 3-(2-isocyanato-2-propyl)-α-methylstyrene, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra( meth) acrylate and the like. An acrylic polyol resin can be obtained by copolymerizing these monomers in the presence of a suitable solvent and polymerization initiator.

In the anchor layer of the present invention, the acrylic polyol resin is used so that the hydroxyl groups in the acrylic polyol resin and the SiH groups in the silicone-based adsorption layer are crosslinked when the silicone composition undergoes an addition reaction to form the anchor layer. This improves the adhesion of the interface with the adsorption layer.

In the present invention, when the acrylic polyol resin in the anchor layer is crosslinked, particularly crosslinked with an isocyanate compound, the hydroxyl groups of the acrylic polyol resin are used for the crosslinking reaction with the NCO groups of the isocyanate. The number of available hydroxyl groups decreases, making it difficult to obtain the effect of improving the adhesion at the interface between the anchor layer and the adsorption layer. Therefore, in the present invention, the acrylic polyol resin is used without cross-linking in the anchor layer. Therefore, it is preferable that the anchor layer of the present invention does not contain a cross-linking agent such as an isocyanate compound.

The acrylic polyol resin to be used preferably has a hydroxyl value in the range of 20 to 90 (mgKOH/g) in terms of solid content. When the hydroxyl value is less than 20, the adhesion between the anchor layer and the adsorption layer is weak, and the adsorption layer tends to separate from the substrate. If the hydroxyl value exceeds 90, the hydroxyl groups derived from the acrylic polyol resin in the anchor layer consume too many SiH groups in the silicone composition forming the adsorption layer, and sufficient curing of the silicone resin cannot be obtained by the addition reaction.

The content of the acrylic polyol resin in the anchor layer in the present invention is preferably in the range of 85 to 97% by weight. If the content is less than 85% by weight, the content of the UV absorber is relatively high, resulting in a decrease in compatibility between the acrylic polyol resin and the UV absorber described above, and an addition reaction that occurs when the UV absorber is laminated on the anchor layer. It inhibits the addition reaction of the adsorption layer made of silicone resin and causes insufficient curing. If the content exceeds 97% by weight, the content of the ultraviolet absorbent becomes relatively small, and sufficient ultraviolet absorbing power cannot be obtained.

(adsorption layer)
The adsorptive layer of the adsorptive film of the present invention needs to be able to adhere reliably to an adherend and to be peelable without adhesive residue even after being exposed to ultraviolet rays. As an adsorption layer for such applications, resins such as natural and synthetic rubbers, silicone resins, urethane resins, acrylic resins, and resins obtained by curing these individual resins with a curing agent can be used. Because of its flexibility, an addition reaction type silicone resin obtained by curing a silicone composition through an addition reaction with heat is particularly suitable for use. By forming an adsorption layer with an addition reaction type silicone resin and combining it with the base material and the anchor layer of the present invention, it is possible to prevent deterioration of the adherend by ultraviolet rays, have good transparency to visible light, and furthermore, perform punching and ultraviolet rays. It is possible to obtain an adsorption film that can have good processing characteristics with respect to laser processing, and can be easily peeled off from the adherend without leaving an adhesive residue when it is no longer needed.

The addition reaction type silicone resin used in the adsorption layer of the present invention includes polyorganosiloxane and silicone resin having two or more vinyl groups in one molecule as a silicone composition, and organohydrogenol having a SiH group as a curing agent. A material obtained by thermally curing through an addition reaction of GENpolysiloxane is preferably used. A suitable adsorption layer can be obtained by containing the above-mentioned polyorganosiloxane, the above-mentioned silicone resin, and the above-mentioned organohydrogenpolysiloxane having SiH groups as a silicone composition and thermally curing the silicone composition.

The adsorption layer using the addition reaction type silicone resin will be described in more detail below.

(silicone resin adsorption layer)
As for the properties of the silicone resin used for the adsorption layer of the present invention, it is required that the surface of the adsorption layer conforms to the surface of the adherend with rubber-like flexibility. Furthermore, when peeling, it is required that the film can be easily peeled off with a small peeling force. In addition, in order to form an adsorption layer having a thickness of at least 5 μm only by coating and heat treatment, the curing reaction of the silicone composition must be performed at a low temperature of 150° C. or less for a short period of time under an addition reaction catalyst such as a platinum catalyst. Diorganopolysiloxane having two or more vinyl groups per molecule, silicone resin, and SiH as a curing agent. It is preferred to use an addition reaction type liquid silicone composition which is heat cured by an addition reaction with an organohydrogenpolysiloxane having groups.

The diorganopolysiloxane having two or more vinyl groups per molecule includes a linear diorganopolysiloxane having vinyl groups only at both ends and a linear diorganopolysiloxane having vinyl groups at both ends and side chains. It is preferable to use at least one selected from organopolysiloxane, branched diorganopolysiloxane having vinyl groups only at the terminals, and branched diorganopolysiloxane having vinyl groups at terminals and side chains.

One form of these diorganopolysiloxanes is a linear diorganopolysiloxane having vinyl groups only at both ends, and is a compound represented by the following general formula (Chem. 1).

(In the formula, R represents the following organic group, and n represents an integer.)

(In the formula, R represents the following organic group, and n and m represent integers.)

The organic group (R) bonded to the silicon atom other than the vinyl group may be different or the same type. Specific examples include alkyl groups such as methyl group, ethyl group and propyl group, and aryl groups such as phenyl group and tolyl group. , or monovalent hydrocarbon groups excluding the same or different unsubstituted or substituted aliphatic unsaturated groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, etc. Preferably, at least 50 mol % of the diorganopolysiloxane is a methyl group, and this diorganopolysiloxane may be used alone or in combination of two or more.

Linear diorganopolysiloxane having vinyl groups at both ends and side chains is a compound in which part of R in the general formula (1) is a vinyl group. A branched polyorganosiloxane having vinyl groups only at the terminals is a compound represented by the general formula (2). A branched polyorganosiloxane having vinyl groups at its terminals and side chains is a compound in which part of R in the general formula (2) is a vinyl group.

The weight average molecular weight of the diorganopolysiloxane having two or more vinyl groups per molecule is preferably in the range of 20,000 to 700,000. When the weight-average molecular weight of the diorganopolysiloxane is less than 20,000, the curability is lowered and the adhesive strength to adherends is lowered. On the other hand, if it exceeds 700,000, the viscosity of the composition becomes too high, making stirring during production difficult.

The silicone resin used in the adsorption layer of the present invention includes M units (R ₃ SiO _1/2 : R is a monovalent organic group such as a methyl group and a phenyl group), D units (R ₂ SiO _2/2 ), A silicone resin composed of T units (RSiO _3/2 ) and Q units (SiO _4/2 ) can be used. It is preferable to contain a so-called conventionally known MQ type organopolysiloxane resin (hereinafter sometimes abbreviated as MQ resin). The content of the MQ resin in the adsorption layer is preferably in the range of 0.01 to 20.00% by weight. A range of 0.10 to 15.00% by weight is particularly preferred. If the content is less than 0.01% by weight, it is difficult to obtain the effect of improving the adhesive strength. If the content exceeds 20.00% by weight, the adhesive strength becomes too strong, and when the adsorption layer is peeled from the adherend, the thin film substrate or thin film sheet that is the adherend may be damaged.

In the combination of the diorganopolysiloxane and the silicone resin, the curing agent used for the curing reaction may be a known one, and examples of the curing agent include organohydrogenpolysiloxanes having SiH groups in the molecule. be done. Among them, it is particularly preferable to use a methylhydrogensiloxane-dimethylsiloxane copolymer. The methylhydrogensiloxane portion of the copolymer preferably has at least 3 silicon-bonded hydrogen atoms in one molecule, but from a practical standpoint, those having two ≡SiH bonds in the molecule are preferred. Preferably, the total amount is up to 50% by weight, the remainder containing at least 3 ≡SiH bonds in the molecule. As for the shape of the molecule, linear, branched, and cyclic ones can be used.

Further, the molar ratio (A)/(B) of the SiH groups (B) in the organohydrogenpolysiloxane to the vinyl groups (A) in the diorganopolysiloxane having vinyl groups is 1.0 to 2.0. is preferably blended so as to be in the range of If the molar ratio (A)/(B) is less than 1.0, the cured density may be insufficient, resulting in a decrease in cohesive strength and holding power. As a result, it becomes difficult to obtain a suitable adhesive force, and it becomes difficult to obtain a sufficient adhesive force due to cross-linking of hydroxyl groups and SiH groups on the surface of the anchor layer.

The addition reaction catalyst used for the curing reaction is chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reaction product of chloroplatinic acid and alcohol, a reaction product of chloroplatinic acid and an olefin compound, and chloroplatinic acid and vinyl group-containing siloxane. reaction products, platinum-olefin complexes, platinum-vinyl group-containing siloxane complexes, rhodium complexes, ruthenium complexes, and the like. Alternatively, these substances may be used by dissolving or dispersing them in a solvent such as isopropanol or toluene, silicone oil or the like. The cured adsorption layer becomes flexible like silicone rubber, and this flexibility facilitates close contact with the adherend.

The addition amount of the addition reaction catalyst is preferably 5 to 2,000 ppm, more preferably 10 to 500 ppm, as a weight ratio of the noble metal component to 100 parts by weight of the silicone composition. If it is less than 5 ppm, the curability may be lowered, the cured density may be lowered, and the holding power may be lowered.

Commercially available forms of the silicone composition according to the present invention include non-solvent type, solvent type, and emulsion type, and any type can be used. Among them, the non-solvent type is very advantageous in terms of safety, sanitation and air pollution because it does not use a solvent. However, even in the solventless type, aromatic hydrocarbon solvents such as toluene and xylene, and fats such as hexane, heptane, octane, and isoparaffin may be used to adjust the viscosity to obtain the desired film thickness. group hydrocarbon solvents, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and isobutyl acetate, ether solvents such as diisopropyl ether and 1,4-dioxane, and mixed solvents thereof. is used.

The amount of the solvent added is preferably 20 to 1,000 parts by weight, particularly 25 to 900 parts by weight, per 100 parts by weight of the silicone composition. If the amount is less than 20 parts by weight, the adhesion between the adsorption layer and the anchor layer may become low and the anchor layer may peel off. During the period from later to curing, the coated adsorption layer partially flows, and the smoothness of the surface of the adsorption layer is reduced.

The properties of the adsorption layer of the present invention are required to have rubber-like flexibility and follow the unevenness of the surface of the adherend when adhered to the adherend to ensure adhesion. For example, when used as the protective film, the film thickness of the adsorption layer is preferably at least 3 μm or more, usually 3 to 20 μm, in order to secure a shearing force in the direction of the adhesion surface of the adsorption layer to the adherend. More preferably ~10 μm. If the thickness is less than 3 μm, the shearing force in the direction of the contact surface of the protective member against the adherend cannot be ensured, and the adsorption film tends to peel off from the adherend particularly during long-term attachment. In addition, when the thickness of the adsorption layer exceeds 20 μm, the amount of resin used for forming the adsorption layer increases, resulting in an increase in manufacturing cost of the adsorption film. In addition, it becomes difficult to cut the adsorption film in the ultraviolet laser processing.

As a method for forming the adsorption layer in the present invention, there is a method of dissolving the resin constituting the adsorption layer in an organic solvent and applying a resin solution whose viscosity is adjusted, or a method of dispersing the resin constituting the adsorption layer in water and applying it. A known method such as a method can be used. As the organic solvent, a general organic solvent can be used without particular limitation. Examples include, but are not limited to, organic solvents for adjusting the viscosity described above.

Examples of coating methods for the adsorption layer of the present invention include a comma knife coater, a die coater and a reverse coater.

The adsorption film of the present invention preferably has a haze value of 5.0% or less, more preferably 2.0% or less, as defined by JIS-K7136. When the haze value exceeds 5.0%, when a photograph or printed matter is used as an adherend, the adherend cannot be seen clearly.

(separator)
In the present invention, it is preferable to use a separator made of a plastic film attached to the surface of the adsorption layer for the purpose of preventing contamination and adhesion of foreign substances to the surface of the adsorption layer and improving the handling of the adsorption film. The separator is made of a highly releasable plastic film, and if desired, a release agent is formed on the surface of the plastic film.

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In addition, "parts" in each example indicate parts by weight unless otherwise specified.

(Examples 1 to 13, Comparative Examples 1 to 6)
Each example and comparative example in which one side of a polyethylene terephthalate (PET) substrate having a thickness of 50 μm was subjected to corona discharge treatment and mixed according to the formulations described in Examples 1 to 13 and Comparative Examples 1 to 6 in Tables 2 and 3. Each anchor layer coating solution was adjusted so that the coating amount after drying was each value shown in Tables 2 and 3, and was applied to the corona discharge-treated surface of each substrate, and heated at 100 ° C. Each anchor layer was formed by heating and drying in order to remove the organic solvent for 2 minutes at . Each adsorption layer coating solution shown in Table 1 below was applied thereon so that the thickness after drying would be the thickness shown in Tables 2 and 3, and then dried by heating at 100° C. for 2 minutes to remove the organic solvent. Then, the coating liquid was cured by heating at 150° C. for 100 seconds to form each adsorption layer, and adsorption films of Examples 1 to 13 and Comparative Examples 1 to 6 were produced. Each produced adsorption film was cut into a width of 25 mm, and the adsorption layer of each adsorption film was adhered to a soda glass plate having a thickness of 1 mm to produce a laminate.

単位：重量部

Unit: part by weight

Tables 2 and 3 show the material composition ratios and evaluation results of each example and comparative example, and each evaluation method is shown below.

(Evaluation method)

(Adhesion evaluation between anchor layer and substrate)
In the adsorption films formed up to the anchor layer of Examples 1 to 13 and Comparative Examples 1 to 6, the anchor layer was rubbed with a finger to visually observe the adhesiveness between the substrate and the anchor layer, and evaluated according to the following criteria.
A: No detachment from the base material after 50 finger rubbings.
○: Detachment from the substrate after rubbing with fingers 10 times or more and less than 50 times.
x: Falling off from the base material after less than 10 finger rubbings.

(Adhesion evaluation between adsorption layer and anchor layer)
The adhesion between the anchor layer and the adsorption layer was visually observed by rubbing the adsorption layers of the adsorption films of Examples 1 to 13 and Comparative Examples 1 to 6, and evaluated according to the following criteria.
A: No detachment from the base material after 15 finger rubbings.
◯: Detachment from the base material after finger rubbing 5 times or more and less than 15 times.
x: Less than 5 rubbings with a finger, falling off from the base material.

(Ultraviolet absorption capacity)
The ultraviolet transmittance at a wavelength of 355 nm of the adsorption films produced in Examples 1 to 13 and Comparative Examples 1 to 6 was measured and evaluated according to the following criteria.
Evaluation criteria ◎: Transmittance is 1.0% or less ○: Transmittance exceeds 1.0% and 1.5% or less ×: Transmittance exceeds 1.5%

(Haze value evaluation result)
The haze values of the adsorption films produced in Examples 1 to 13 and Comparative Examples 1 to 6 were measured according to JIS-K7136 and evaluated according to the following criteria.
◎: Haze value is 2.0% or less ○: Haze value is over 2.0% and 5.0% or less ×: Haze value is over 5.0% Measuring instrument: Nippon Denshoku Industries Co., Ltd. NDH- 2000

(Precipitation of UV absorber)
After the laminates of the soda glass plates and the respective adsorption films prepared in Examples 1 to 13 and Comparative Examples 1 to 6 were allowed to stand at room temperature for 1 week, the presence or absence of precipitation of the ultraviolet absorber was confirmed by visual confirmation. .
(double-circle): Precipitation is not seen.
○: Precipitation is slightly observed, but there is no problem.
x: Precipitation is observed.

(Adhesive residue evaluation of adsorption layer)
In the laminates of the soda glass plate and each adsorption film prepared in Examples 1 to 13 and Comparative Examples 1 to 6, the laminate was heated at 180° C. for 2 minutes and then cooled to room temperature. 180° peeling was performed at 300 mm/min, and adhesive residue was evaluated by a method of visually confirming adhesion of the adsorption layer to the soda glass plate after peeling the adsorption film.
Evaluation criteria ⊚: No adhesion of the adsorption layer to the soda glass plate.
◯: Fine dots of 0.5 mm ² or less attached to the soda glass plate of the adsorption layer.
x: Adherence of 0.5 mm ² or more on the soda glass plate of the adsorption layer.

(Processability evaluation)
The lamination of the soda glass plate and each adsorption film prepared in Examples 1 to 13 and Comparative Examples 1 to 6 was irradiated with an ultraviolet laser using an ultraviolet laser processing machine to confirm the processing characteristics. made an evaluation.
Irradiation laser: wavelength 355 nm, pulse width 30 ns, frequency 10 kHz, pulse energy 10 μJ/pulse
Good: The adsorption film could be cut with an ultraviolet laser.
x: The adsorption film could not be cut with an ultraviolet laser.

Claims (4)

An adsorption film in which an anchor layer and an adsorption layer are laminated in this order on one side of a substrate, wherein the adsorption layer is a silicone-based film obtained by laminating at least one silicone composition on the anchor layer and then curing it by an addition reaction. It is an adsorption layer , and the anchor layer contains 85 to 93% by weight of an acrylic polyol resin and 0.30 to 1.80 g/m ² of an ultraviolet absorber, and the coating weight of the anchor layer is 3 to 12 g/m ^{2 .} An adsorption film characterized by:
2. The adsorption film according to claim 1, wherein said UV absorber in said anchor layer is a UV absorber having a benzotriazole skeleton. The adsorption layer is obtained by curing a silicone composition containing at least a vinyl group-containing polydimethylsiloxane composition, a methylhydrogensiloxane-dimethylsiloxane copolymer, and a silicone resin as the silicone composition by an addition reaction, and the thickness of the adsorption layer 3 to 20 μm, the adsorption film according to claim 1 or 2. The adsorption film according to any one of claims 1 to 3, characterized in that the UV transmittance of said adsorption film at a wavelength of 355 nm is 1.5% or less.