JP2019077750A - Silicone adsorptive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide reworkability at the time of attaching to an adherend, air release property, and scratch resistance, and a position with respect to the adherend even after the protective film is not peeled from the adherend after being adhered to the adherend. Providing a protective film that can correct misalignment. SOLUTION: This is a silicone adsorption film in which a silicone adsorption layer 2 is laminated on a thermoplastic urethane elastomer substrate 3, wherein the silicone adsorption layer 2 contains MQ resin in an amount of 37 to 52% by weight in the solid content. The elastomer base material 3 has a tensile strength of 56 to 71 MPa, the hard coat layer 4 is laminated on the surface of the urethane elastomer base material 3 opposite to the surface on which the silicone adsorption layer 2 is laminated, and the hard coat layer 4 is made of urethane acrylate. Silicone adsorption film X having a thickness of 0.5 to 5.0 μm as a main component. Preferably, the silicone adsorption film X in which the diorganopolysiloxane is one or more selected from the group of linear/branched diorganosiloxanes having vinyl groups at the terminal and side chains. [Selection diagram] Figure 1

Description

The present invention relates to a silicone adsorption film for a protective film which is attached to the surface of a screen such as a touch panel and used to protect the screen.

DESCRIPTION OF RELATED ART Conventionally, the silicone adsorption film which laminates | stacks a silicone adsorption layer on a base material sheet, affixes the silicone adsorption sheet containing a base material sheet to a to-be-adhered body, and is used is disclosed by patent document 1 etc.

The silicone adsorption film used by sticking the silicone adsorption layer to the adherend has a property that the adsorption power does not rise after sticking, so it is easy to peel off and stick again after sticking, that is, it has good reworkability There is. In addition, the silicone adsorption film has the property that air does not easily enter between the adherend and the adherend at the time of adhesion, and even if air enters between the adherend and the adherend, this air can be easily removed. It has a good air venting property.

As described above, since the silicone adsorption film has good reworkability and air release property to the adherend, it is necessary to reattach when the attachment is mistaken and to replace when the film is deteriorated. In addition, it is suitably used for applications where air can not enter between the substrate and the substrate. As such applications, there are a protective film of a screen of an image display device, an advertising film attached to a glass surface of a shop front or a car window, and the like.

By the way, the silicone adsorption layer of the silicone adsorption film has the adhesion to the adherend as well as the reworkability to the adherend as described above. In particular, when the adherend is a smooth surface such as a screen of an image display device, the adhesion of the silicone adsorption layer becomes more remarkable. Therefore, when the silicone adsorption layer is attached to a smooth adherend, the adherend adheres to the silicone adsorption layer, making it difficult for the silicone adsorption film to slide on the adherend and move.

When sticking a protective film on the screen of an image display apparatus, it may stick accidentally at the position shifted with respect to the position to stick. When it pastes in the position which shifted in this way, position gap can be corrected by peeling off a protective film and sticking again. However, when the protective film is peeled off and attached again, dust may adhere to the silicone adsorption layer. Further, in the case of a small positional deviation, the positional deviation may be larger than at the beginning by pasting, and the positional deviation of the protective film could not be easily corrected.

JP, 2016-120646, A

The present invention has been made in view of the above-mentioned circumstances, and it has the reworkability, air leakage and scratch resistance when attached to an adherend, and the adherend after being attached to an adherend. Providing a protective film capable of correcting displacement of the protective film relative to the adherend simply by pressing the protective film with a finger or the like without sliding the protective film from the adherend by sliding while stretching the upper and lower sides It is the purpose.

  The first invention is a silicone adsorption film in which a silicone adsorption layer is laminated on a thermoplastic urethane elastomer substrate directly or through another layer, and the silicone adsorption layer has two or more alkenyl groups in one molecule. A silicone composition comprising an organohydrogenpolysiloxane and a diorganopolysiloxane having an epoxy group, cured by an addition reaction, and the silicone adsorption layer further comprises an MQ resin in an amount of 37% by weight of the solid content of the silicone adsorption layer. %, And the tensile strength of the thermoplastic urethane elastomer base is 56 MPa or more and 71 MPa or less, directly or otherwise on the surface of the urethane elastomer base opposite to the surface on which the silicone adsorption layer is laminated. The hard coat layer is laminated through the layer of A main component relations, the thickness of the hard coat layer is a silicone adsorbent film is 0.5μm or more 5.0μm or less.

In the second invention, the diorganopolysiloxane is a linear diorganopolysiloxane having a vinyl group only at both ends, a linear diorganopolysiloxane having a vinyl group at both ends and a side chain, a vinyl only at the end It is a silicone adsorption film given in the 1st invention which is at least one sort chosen from a branched diorganopolysiloxane which has a group, and a branched diorganopolysiloxane which has a vinyl group in a terminal and a side chain.

3rd invention is a silicone adsorption film as described in the 1st or 2nd invention whose thickness of the said thermoplastic urethane elastomer base material is 50 micrometers-150 micrometers.

4th invention is a silicone adsorption | suction film in any one of 1st-3rd invention whose gel fraction of the said silicone adsorption layer is 45% or more and 62% or less.

A fifth invention is the silicone adsorption film according to any one of the first to fourth inventions, wherein the indentation creep of the silicone adsorption layer is 4.1% or more and 8.0% or less.

The protective film of the present invention uses a thermoplastic urethane elastomer as a substrate, has a silicone adsorption layer on one side of the substrate, and has a hard coat layer on the substrate side opposite to the silicone adsorption layer And In the protective film of the present invention, the tensile strength of the substrate is 56 MPa or more and 71 MPa or less, and the silicone adsorption layer contains the MQ resin at a ratio of 37% by weight or more and 52% by weight or less in the solid content. Is mainly composed of urethane acrylate having a thickness of 0.5 μm to 5.0 μm. With such a configuration, in the protective film of the present invention, the protective film is stretched and shrunk simply by pressing the protective film with a finger or the like while being stuck to the adherend via the silicone adsorption layer. It is possible to slide on the adherend to correct the displacement of the protective film relative to the adherend. Therefore, the present invention provides a protective film having good reworkability, air leakage and scratch resistance due to a hard coat layer, as well as the ability to correct displacement of affixing position without peeling and reattaching. Can. In addition, since the protective film of the present invention can correct the positional deviation while being stuck to the adherend, it is possible to easily correct even a slight positional deviation.

The protective film (silicone adsorption film) of the present invention will be described in more detail below.

(Protective film)
The schematic diagram of a layer structure of the protective film X which is 1st Embodiment of this invention is shown in FIG. The protective film X has three layers of the anchor layer 2A, the silicone adsorption layer 2 and the separator A1 on one side of the thermoplastic urethane elastomer base material 3 (hereinafter referred to as TPU base material 3) from the TPU base material 3 side. The layers are stacked in this order, and the anchor layer 4A and the hard coat layer 4 are stacked on the other side of the TPU base 3 in this order from the TPU base 3 side.

(Thermoplastic urethane elastomer base material: TPU base material 3)
The TPU base material 3 in the present invention may contain an agent such as an antioxidant, an antistatic agent, an antifungal agent, and the like. The TPU base material 3 is prepared by adding a thermoplastic urethane elastomer and other components to an extruder, a kneader, a Banbury mixer or the like and melt-kneading it to prepare a kneaded product (master batch) by a conventionally known method. A sheet-like or plate-like sheet can be used by passing the sheet through a calender, a T-die or the like.

In the protective film X, it is preferable to form the TPU substrate 3 on a temporary support such as a PET film, or use a commercially available TPU substrate provided on the temporary support. This is because the TPU base material 3 alone has a small tensile strength, and when laminating the anchor layer 4A or the anchor layer 2A on the TPU base material 3, the TPU base material 3 may stretch or break. For this reason, it is preferable to laminate the anchor layer 4A on the TPU base material 3 in the state of being laminated on the temporary support. The thickness of the TPU substrate 3 is preferably 50 μm or more and 150 μm or less, and more preferably 70 μm or more and 100 μm or less. When the thickness of the TPU base material 3 is larger than 150 μm, it becomes difficult to correct the positional deviation of the protective film while being stuck on the adherend. On the other hand, when the thickness of the TPU base material is less than 50 μm, dents easily occur. As physical properties of the TPU substrate 3, it is preferable that the tensile strength is 56 MPa or more and 71 MPa or less. When the tensile strength exceeds 71 MPa, the flexibility of the protective film is lost, and it becomes difficult to correct the positional deviation of the protective film while being stuck on the adherend. On the other hand, when the tensile strength is less than 56 MPa, the TPU base material is easily plastically deformed and easily broken.

As a temporary support on which the TPU substrate 3 is laminated, a film having a single layer or multilayer structure made of polyethylene terephthalate, polyethylene, polystyrene, polypropylene, nylon, urethane, polyvinylidene chloride, polyvinyl chloride or the like can be used. The thickness of the temporary support is usually 10 to 300 μm, preferably 25 to 200 μm.

As a method of coating or laminating a kneaded product (master batch) obtained by melting a thermoplastic urethane elastomer on a temporary support, a multistage roll coater represented by a three offset gravure coater or a five roll coater, a direct gravure coater, Well-known methods, such as a bar coater, an air knife coater, and a T-die, are suitably used.

(Thermoplastic urethane elastomer)
As a thermoplastic urethane elastomer (TPU), although what was comprised from the following hard segment and soft segment is mentioned, it is a point which makes correction of the position gap in the state stuck on the adherend of protective film X easy. Thus, the tensile strength and the elongation at break of the TPU substrate 3 can be adjusted to appropriate values by appropriately adjusting the blending amounts of the isocyanate and the polyol component.

Examples of the hard segment include those composed of diisocyanate and 1,9 nonanediol, alkanediol such as 1,4-butanediol and diethylene glycol, or dialkylene glycol such as polytetramethylene ether glycol.

Examples of the soft segment include diisocyanates or adducts obtained by blending an alkanediol such as 1,3 butanediol with diisocyanate, or polyoxypropylene, polyoxyethylene, polyoxypropylene-polyoxyethylene, polyoxybutylene, polyoxybutylene-poly Polyethers such as oxyethylene, polytetramethylene, or polyoxybutylene-polyoxyethylene-glycol, or polyesters such as alkanediol-polyadipate, and polycarbonate diols can be mentioned. Here, as the diisocyanate, 4,4'-diphenylmethane-diisocyanate, 1,6-hexamethylene-diisocyanate, isophorone diisocyanate and the like can be mentioned.

  With the TPU base material 3 of the protective film X, the thermoplastic urethane elastomer component other than the thermoplastic urethane elastomer component is in a range that does not impair the flexibility for satisfying the property capable of positional displacement correction while being stuck on the adherend of the protective film X Can contain other ingredients. Examples of other components include modifiers (processing aids), plasticizers, heat stabilizers, antioxidants, light stabilizers, UV absorbers, flame retardant aids, antiblocking agents, etc. These can be used alone or in combination of two or more as needed.

(Silicone adsorption layer)
The protective film X of the present invention is provided on one surface of the TPU substrate 3 with a silicone adsorption layer for affixing onto an adherend such as a screen. The adsorptive layer of the present invention is preferably one having transparency in consideration of use as a screen protective film, and in the case where only the protective film is scratched in consideration of use by sticking to the screen of an expensive device And the like, it is preferable that re-sticking is easy. In order to satisfy these performances, the adsorbent used in the adsorption layer of the present invention is preferably a silicone adsorbent among various adsorbents. Among silicone adsorbents, an adsorbent containing an MQ resin is also a silicone adsorbent from the viewpoint of securing flexibility for satisfying the property capable of correcting positional deviation while being stuck on the adherend of the protective film X. Particularly preferably, the protective film X is provided with a silicone adsorption layer 2 using a silicone-based adsorbent containing an MQ resin.

(Anchor layer 2A)
In the protective film X according to the present invention, it is preferable to provide an anchor layer 2A between the TPU substrate 3 and the silicone adsorption layer 2. The purpose of providing the anchor layer 2A is to improve the adhesion between the TPU substrate 3 and the silicone adsorption layer 2, and to increase the adhesion with time due to the reaction between the glass surface and the silicone oligomer, particularly when the adherend is glass. When the protective film X is peeled off, it can be peeled off smoothly without generating a silicone residue on the glass surface which is the adherend.

As resin used for anchor layer 2A, it is preferred to use polyester system resin which has an acid value of 7-100 mgKOH / g.

When the acid value of the polyester resin is less than 7 mg KOH / g, the adhesion between the anchor layer 2A and the silicone adsorption layer 2 and between the anchor layer 2A and the TPU base material 3 is weak. It becomes easy to separate from the material 3. In addition, when the protective film X is peeled off after the protective film X is attached to the adherend, a silicone residue is easily generated on the adherend. When the acid value exceeds 100 mg KOH / g, the water resistance of the resin film is insufficient.

The anchor layer 2A coating liquid can be prepared by a conventionally known method.

 The thickness of the anchor layer 2A is preferably 0.1 to 5 μm, and more preferably 0.15 to 3 μm. When the thickness of the anchor layer 2A is less than 0.1 μm, the thermally crosslinked silicone adsorption layer 2 is easily separated from the anchor layer 2A, and the anchor layer 2A is also easily separated from the TPU substrate 3. On the other hand, when the thickness of the anchor layer 2A exceeds 5 μm, it is useless, the flexibility of the entire protective film X is lost, and the property that can be corrected for positional deviation is reduced while being stuck on the adherend.

The coating liquid for the anchor layer 2A of the protective film X is mixed with water in the range not to inhibit the dispersibility of the coating liquid in order to improve the wettability to the TPU substrate 3 in addition to the above resin components. Organic solvents such as organic alcohols may be added. In addition, as another method, a wettability improver can be added in a range not causing catalyst poisoning to the crosslinking reaction of the addition reaction type silicone resin. Further, if necessary, those generally added to this type of composition such as a vulcanizing agent, a vulcanization accelerator, etc. can be added in the range where the effect of the present invention is not reduced.

(Silicone adsorption layer 2)
The properties of silicone used for the silicone adsorption layer 2 of the protective film X are required to be high in transparency and to have flexibility like rubber. The performance of the silicone adsorption layer 2 is required to be such that the surface follows the surface of the adherend and can be easily peeled off from the surface of the adherend with a small peeling force at the time of peeling from the adherend. In addition, as processing performance of silicone used for the silicone adsorption layer 2, it is possible to provide a crosslinked silicone adsorption layer 2 only by coating and heat treatment without using a method of coating thickness with a film thickness of at least 10 μm or more. Is required. As such silicones, addition type liquid silicone resins which are cross-linked in a short time at a low temperature of 150 ° C. or less in curing reaction and which are transparent, heat resistant, excellent in compression set characteristics and low in viscosity and liquid type Use is preferred. The addition type liquid silicone resin is a hydroxyl catalyst of a diorganopolysiloxane having an alkenyl group such as two or more vinyl groups in one molecule and an organohydrogenpolysiloxane having a SiH group as a crosslinking agent under a platinum catalyst or the like. It can be thermally crosslinked by reaction.

As such a diorganopolysiloxane, a linear diorganopolysiloxane having a vinyl group at both ends, a linear diorganopolysiloxane having a vinyl group at both ends and a side chain, a vinyl group at only the end It is preferable to use at least one or more selected from branched diorganopolysiloxanes having one or more terminal groups and branched diorganopolysiloxanes having a vinyl group at the terminal and side chains.

A linear diorganopolysiloxane having a vinyl group only at both ends, which is one form of these diorganopolysiloxanes, is represented by the following general formula (Formula 1).

(Wherein R represents the following organic group, n represents an integer)

(Wherein R represents the following organic group, and m and n represent integers)

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

The linear diorganopolysiloxane having a vinyl group at both ends and a side chain is a diorganopolysiloxane in which a part of R in the general formula (Formula 1) is a vinyl group. The branched diorganopolysiloxane having a vinyl group only at the end is a diorganopolysiloxane represented by the above general formula (Formula 2). A branched diorganopolysiloxane having a vinyl group at the end and a side chain is a diorganopolysiloxane in which a part of R in the general formula (Formula 2) is a vinyl group.

(MQ resin)
In addition to the above components, the silicone composition constituting the silicone adsorption layer 2 of the present invention further comprises M units (R ₃ SiO _1/2 : R is a monovalent organic group such as a methyl group or a phenyl group) and Q It contains an MQ resin consisting of units (SiO _{4 · 1⁄2} ) as an essential component. The MQ resin may be either non-reactive or reactive, and may contain both non-reactive and reactive.

The MQ resin is preferably contained in an amount of 37% by weight or more and 52% by weight or less based on the solid content of the silicone adsorption layer 2. When the content of the MQ resin in the solid content of the silicone adsorption layer 2 is less than 37% by weight, the flexibility of the entire protective film X is lost, and the property that the positional deviation can be corrected while being stuck on the adherend is If the content is decreased to exceed 52% by weight, the silicone adsorption layer 2 is likely to be plastically deformed and dents are easily generated.

When non-reactive MQ resin is used, the molar ratio of M unit (R ₃ SiO _1/2 ) / Q unit (SiO _{4 1/2} ) is preferably 0.6 to 1.8. If the molar ratio of M unit / Q unit is less than 0.6, the adhesion and tack may decrease, and if it exceeds 1.8, the adhesion and retention may decrease.

The weight-average molecular weight (Mw) of the non-reactive MQ resin is preferably 100,000 to 300,000. If the weight average molecular weight (Mw) of the non-reactive MQ resin is less than the above range, the desired adsorptive power can not be obtained. On the other hand, when the weight average molecular weight (Mw) of the non-reactive MQ resin exceeds the above range, the adsorption layer is likely to be plastically deformed and dents are likely to be generated.

In addition, the reactive MQ resin is composed of (R1) ₂ (OH) SiO _1/2 units, (R1) ₃ SiO _1/2 units and SiO ₂ units, and one or more silanol groups (OH groups) in one molecule. Organopolysiloxane resin. In the silicone adsorption layer 2 of the present invention, from the viewpoint of low silicone migration, 0.5 of the total of all functional groups contained in the reactive MQ resin, that is, the functional group OH and the functional group (R1) 3 It is preferable that -10 mol% is a silanol group (OH group).

The sum of the molar ratio of (R1) ₂ (OH) SiO _1/2 units and (R1) ₃ SiO _1/2 units to the SiO ₂ units constituting the reactive MQ resin is 0.5 to 1.2. preferable. When the sum of the molar ratio of (R1) ₂ (OH) SiO _1/2 units and (R1) ₃ SiO _1/2 units to SiO ₂ units is less than 0.5, the adsorptive power may decrease, and the molar ratio is If it exceeds 1.2, the adhesion (holding power) of the silicone adsorption layer 2 obtained tends to decrease.

R1 is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and specifically, an alkyl group, an aryl group, a cycloalkyl group, an alkenyl group, and monovalent hydrocarbons thereof And groups in which one or more hydrogen atoms of the group are substituted with a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, a cyano group or the like. Industrially, methyl group is preferable, and 90 to 99.5 mol% of the total of all functional groups contained in the reactive MQ resin, that is, the total of the silanol group (OH group) and the functional group R1. Is preferably a methyl group.

The crosslinking agent used for the crosslinking reaction of the composition which comprises the silicone adsorption layer 2 here may be a well-known thing. Examples of crosslinking agents include organohydrogenpolysiloxanes. Organohydrogenpolysiloxanes have at least 3 hydrogen atoms bonded to silicon atoms in one molecule, but from a practical point of view, 50% by weight of those having two ≡SiH bonds in the molecule The remainder may include at least three 少 な く と も SiH bonds in the molecule.

The platinum-based catalyst used for the crosslinking reaction may be a known one, and examples thereof include chloroplatinic acid such as chloroplatinic acid and chloroplatinic acid, alcohol compounds of chloroplatinic acid, aldehyde compounds or chloroplatinic acid and various olefins Chain salt with and the like. The cross-linked silicone layer becomes flexible like silicone rubber, and this softness makes it easy to adhere to the adherend.

  Commercially available forms of silicone according to the present invention include solvent-free, solvent-type, and emulsion-type, but any type can be used. Among them, the non-solvent type is very advantageous in terms of safety, hygiene and air pollution since it does not use a solvent. However, even if it is a non-solvent type, an organic solvent such as toluene can be added as needed to adjust the viscosity to obtain a desired film thickness.

  As described above, as the properties of the silicone adsorption layer, it is required to have flexibility like rubber and to secure the adhesion following the irregularities of the surface of the adherend at the time of adhesion to the adherend. . When used as a screen protective film, the thickness of the silicone adsorption layer needs to be at least 10 μm, usually 15 to 50 μm, in order to secure the shear force in the adhesion surface direction of the silicone adsorption layer to the adherend. If the thickness is 10 μm or less, the adhesion of the protective film to the adherend can not be secured, and the protective film is likely to peel off from the adherend particularly when attached for a long period of time.

In order to ensure the property that the positional displacement can be corrected while being stuck on the adherend of the protective film X, the gel fraction of the silicone adsorption layer 2 is preferably in the range of 45% to 62%. When the gel fraction is less than 45%, the flexibility of the entire protective film X is lost, and the property of being able to be displaced can be reduced while being stuck on the adherend. In addition, even if the gel fraction of the silicone adsorption layer 2 exceeds 62%, the property capable of correcting displacement can be secured, but if it exceeds 62%, the silicone adsorption layer 2 is easily plastically deformed and dents are generated. 62% or less is preferable because it becomes easy to do.

Further, preferable physical properties of the silicone adsorption layer 2 can be expressed by indentation creep, and the preferable indentation creep is 4.1% or more and 8.0% or less. When the indentation creep of the silicone adsorption layer 2 is less than 4.1%, the flexibility of the entire protective film X is lost, and the property capable of positional deviation correction while being stuck on the adherend decreases, 8.0 If it exceeds 10%, the silicone adsorption layer 2 is likely to be plastically deformed and dents are likely to be generated.

As a result of earnest efforts, the inventors of the present invention have the property that in the protective film X, the positional displacement can be corrected while being stuck on the adherend by the combination of the substrate having specific physical properties and the specific adsorptive layer. I found that I could do things. Moreover, if it is a specific hard-coat layer, even if this hard-coat layer is provided in the outermost layer at the time of affixing the protective film X to a to-be-adhered body, positional shift correction is possible, as it is stuck on the to-be-adhered It has been found that it is possible to maintain That is, by combining TPU base material 3 having a tensile strength of 56 MPa or more and 71 MPa or less, and a silicone adsorption layer containing 37% by weight or more and 52% or less by weight of MQ resin in the silicone adsorption layer solid content, It has been found that it is possible to have the property of being able to correct positional displacement as it is attached. Moreover, if it is a hard-coat layer which has urethane acrylate as a main component and whose thickness is 0.5 micrometer-5.0 micrometers, when the protective film which laminated | stacked the said TPU base material and the silicone adsorption layer is stuck on a to-be-adhered body. It has been found that even if the hard coat layer is provided on the outermost layer of the above, it is possible to maintain the property of being able to correct positional deviation while being stuck on the adherend.

Furthermore, as a silicone adsorption layer combined with TPU base material 3 whose tensile strength is 56 MPa or more and 71 MPa or less, the gel fraction is in the range of 45 to 62%, or the indentation creep is 4. It was also found that one having 1% or more and 8.0% or less is more effective for the property that can be corrected for displacement while being stuck on the adherend.

By combining the TPU substrate 3 with the silicone adsorption layer 2 and pressing the protective film X pasted on the adherend with a finger or the like so as to slide on the adherend, the TPU substrate 3 and silicone adsorption are adsorbed. The layer 2 starts to deform in substantially the same direction, and the deformation starts the sliding of the silicone adsorption layer 2 relative to the adherend. When the content of MQ resin in the silicone adsorption layer increases, the adhesion of the silicone adsorption layer increases, and the silicone adsorption layer 2 becomes difficult to slip against the adherend, but the content of the MQ resin is the silicone adsorption layer If it is 52% by weight or less in the solid content, internal stress generated by deformation of the TPU substrate 3 and the silicone adsorption layer 2 acts, and the silicone adsorption layer 2 can slide on the adherend. Even if the adherend has a smooth surface such as glass or plastic, the positional displacement of the protective film X can be corrected as it is stuck on the adherend, but among these, slippage is particularly easy with respect to fluorine glass. And when the adherend is fluorine glass, it can be particularly suitably used.

One of TPU base material 3 and silicone adsorption layer 2 is out of the above range, that is, the tensile strength of TPU base material 3 is not 56 MPa or more and 71 MPa or less, or MQ resin in silicone adsorption layer solid content is 37 wt% or more 52 Since the TPU base material 3 and the silicone adsorption layer 2 do not deform at a similar ratio in a balanced manner unless the weight% or less, the protective film attached on the adherend may be slipped on the adherend Even if it is pressed with a finger or the like, it is not possible to correct positional deviation while the protective film is stuck on the adherend. For example, when the tensile strength of the TPU substrate 3 exceeds 37 MPa, the protective film attached to the adherend is 37 wt% or more and 52 wt% or less of the MQ resin in the solid content of the silicone adsorption layer. The TPU substrate 3 is not deformed even if it is pressed by a finger or the like so as to slide on the adherend. Since the TPU substrate 3 is on the upper layer with respect to the adherend rather than the silicone adsorption layer 2, the silicone adsorption layer 2 will not be deformed if the TPU substrate 3 is not deformed, and the position of the protective film It is not possible to correct the deviation. In addition, although the tensile strength of the TPU substrate 3 is in the range of 56 MPa to 71 MPa, the same applies to the case where the MQ resin in the solid content of the silicone adsorption layer exceeds 52 wt%. Since the material 3 is not easily deformed, the TPU substrate 3 is not deformed even if the protective film stuck on the adherend is pushed by a finger or the like so as to slide on the adherend, and as a result, the positional displacement of the protective film Can not be fixed.

If the MQ resin in the solid content of the silicone adsorption layer is less than 37% by weight and the tensile strength of the TPU substrate 3 exceeds 71 MPa, the entire protective film becomes hard, so the protection adhered on the adherend Even if the film is pushed by a finger or the like so as to slide on the adherend, the positional deviation of the protective film can not be corrected. On the other hand, when the MQ resin in the solid content of the silicone adsorption layer exceeds 52% by weight and the tensile strength of the TPU substrate 3 is less than 56 MPa, the entire protective film becomes too soft and is stuck on the adherend When the protective film is pressed with a finger or the like so as to slide on the adherend, the protective film is wrinkled, and the positional deviation can not be corrected as intended.

The protective film X is particularly suitable for position shift correction of about several millimeters. As described above, the TPU base material 3 and the silicone adsorption layer 2 begin to deform at substantially the same ratio, and this deformation becomes the starting point, and the silicone adsorption layer 2 slips against the adherend, and the protective film X Misalignment of is corrected. Therefore, when the displacement is corrected by pressing a part of the protective film having a large area with a finger or the like, the displacement is corrected by extending or shrinking only the protective film of the portion pressed by the finger. Also in the protective film X whose positional deviation has been corrected in such a state, an appearance defect such as whitening does not occur. On the other hand, it is difficult to correct the positional deviation by the method of peeling off and attaching one end to correct the positional deviation of about several mm, the protective film X is particularly suitable for such positional deviation correction of about several mm. It can be used suitably.

The protective film X is also capable of positional deviation of 10 mm or more, or positional deviation correction for moving the entire protective film. For example, if the protective film is moved while pressing the entire protective film X using a jig or the like having a flat surface substantially the same as the shape of the protective film, the protective film X is not partially deformed, The entire protective film can be moved. However, because the protective film X has good reworkability and air release property as well as such a property capable of correcting positional displacement, if large positional displacement is to be corrected, the film is pasted and re-adhered. If a positional deviation of about several mm remains, the positional deviation can be corrected while being stuck on the adherend.

As a coating method of the anchor layer 2A coating liquid and the silicone adsorption layer 2 coating liquid, a multistage roll coater represented by a three offset gravure coater or a five roll coater, a direct gravure coater, a bar coater, an air knife coater, etc. The method of is suitably used.

(Separator A1)
The separator A1 is a resin film separator for preventing dirt and foreign matter from adhering to the surface of the silicone adsorption layer 2 and improving the handling of the protective film X. The separator A1 is used by being bonded to the surface of the silicone adsorption layer 2. The separator A1 is made of a highly releasable resin film made of polyethylene terephthalate, polyethylene, polypropylene or the like, and, if desired, one coated with a release agent such as a silicone material on the surface is used.

(Anchor layer 4A)
In the protective film X which concerns on this invention, it is preferable to provide the hard-coat layer 4 in the surface on the opposite side of the TPU base material 3 in which the silicone adsorption layer 2 was provided. Since the TPU substrate 3 is soft, the surface of the protective film X is easily damaged if the protective film X is used in a state where the TPU substrate 3 is exposed. The hard coat layer 4 is preferably provided with an anchor layer 4A on the TPU base material 3 and laminated on the anchor layer 4A. The purpose of providing the anchor layer 4A is to uniformly coat the thin hard coat layer 4 to prevent the occurrence of curling during curing and to improve the adhesion between the hard coat layer 4 and the TPU substrate 3 is there.

The anchor layer 4A preferably contains a polyol as a main component, and although polyether polyol, polyester polyol, acrylic polyol, polycarbonate polyol, epoxy polyol and the like can be used, the solvent-based hard coat layer is coated on the anchor layer 4A. From the viewpoint of preventing whitening of the TPU base material 3 when the liquid is applied, polyester polyols are more preferable.

  In the present invention, it is preferable that the anchor layer 4A is compounded with 0.1 to 100 parts by weight of a carbodiimide compound as a crosslinking agent with respect to 100 parts by weight of the polyester polyol. When the blending amount of the carbodiimide compound is less than 0.1 parts by weight, the coating liquid of the anchor layer 4A is not sufficiently crosslinked. In addition, when the content of the carbodiimide compound exceeds 100 parts by weight, the anchor layer 4A is whitened. In the protective film X, by using such an anchor layer 4A, it is possible to ensure good adhesion of the hard coat layer 4 to the TPU base material 3.

  The polyester polyol which is the main component of the anchor layer 4A is one obtained by condensation polymerization of polyvalent carboxylic acid and polyvalent alcohol. Examples of polyvalent carboxylic acids include aliphatic polyvalent carboxylic acids such as malonic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, and unsaturated polyvalent carboxylic acids such as fumaric acid and maleic anhydride Acids, phthalic acid, dimethyl phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalic acid, aromatic polyvalent carboxylic acids such as 5-sodium sulfoisophthalic acid, and the like can be mentioned.

  Examples of polyhydric alcohols include aliphatic glycols, alicyclic glycols, aromatic glycols and aliphatic triols. Although various well-known polyester polyols by these combination can be used, the thing of the range of 1000-40000 as a number average molecular weight is preferable, and a thing of 1-30 mgKOH / g can be used as a hydroxyl value. If the number average molecular weight is less than 1000, the adhesion is insufficient, and if it exceeds 40000, the processability, the appearance of the coating film, and the solubility may be poor.

  As the carbodiimide compound, any one can be used, and among them, bis (2,6-diisopropylphenyl) carbodiimide and 2,6,2 ', 6'-tetraisopropyldiphenylcarbodiimide are preferable from the viewpoint of reactivity and stability. preferable. Furthermore, as said carbodiimide compound, a commercially available carbodiimide compound can be suitably used, without needing to synthesize | combine. As such commercially available carbodiimide compounds, for example, those of various grades sold by Nisshinbo Chemical Co., Ltd. under the trade name of "carbodiimide" (registered trademark) can be used.

  The carbodiimide compound is one having a carbodiimide equivalent (molecular weight / number of carbodiimide groups contained in the molecule) of 100 to 1,000.

The thickness of the anchor layer 4A is preferably 0.2 μm or more and 5 μm or less, more preferably 0.3 μm or more and 2 μm or less. If the thickness of the anchor layer 4A is less than 0.2 μm, the adhesion between the hard coat layer 4 and the TPU substrate 3 may be insufficient. On the other hand, if it exceeds 5 μm, the property of being able to correct the positional deviation is lowered while being stuck on the adherend of the protective film X.

(Hard coat layer 4)
The hard coat layer 4 should have flexibility in order to ensure the property of being able to correct the positional deviation of the protective film X as it is stuck on the adherend. In order to ensure the flexibility of the hard coat layer 4, it is necessary to make the hard coat layer 4 thin. Therefore, it is preferable that the hard coat layer 4 suitable for the present invention has sufficient scratch resistance even if it is thin and has the property of being hard to crack. As such a hard coat layer 4, it is preferable to apply a hard coat layer coating liquid containing urethane acrylate as a main component after heat or light curing after coating. It is preferable that the coating liquid which has a urethane acrylate as a main component is a solvent type coating liquid. It is difficult to make the viscosity of the non-solvent type coating liquid low and it is easy to generate coating unevenness, so it is not suitable for coating a thin hard coat layer as in the present invention, and coating unevenness occurs. By being easy to do, curling at the time of curing is also easily generated.

The urethane acrylate used in the present invention is produced by a known method using a polyol, diisocyanate or hydroxy (meth) acrylate in combination with one or more kinds.

Examples of the polyol include spiro glycol, ethoxylated bisphenol A, ethoxylated bisphenol S, polytetramethylene oxide diol, polytetramethylene oxide triol, polypropylene oxide diol, polypropylene oxide triol and the like.

Examples of the diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3′-dimethyl-4, 4-diphenyl diisocyanate, xylene diisocyanate, trimethylhexamethylene diisocyanate, 4, 4-diphenylmethane diisocyanate, tolylene diisocyanate, etc. may be mentioned.

As the above-mentioned hydroxy (meth) acrylate, for example, 2, 2-bis [4- (3-acryloxy 2-hydroxypropoxy) phenyl] propane, bis [4- (3-acryloxy 2- hydroxypropoxy) phenyl] methane , Bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] sulfone, bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] ether, 4,4-bis [4- (3-acryloxy-) 2-hydroxypropoxy) phenyl] cyclohexane, 9,9-bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, 9,9-bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl ] Anthraquinone, 2-hydroxyethyl (meth) acrylate 2-hydroxypropyl acrylate, glycidol dimethacrylate, pentaerythritol triacrylate, and the like.

Examples of the photopolymerization initiator used for the ionizing radiation polymerization reaction of the urethane acrylate used in the present invention include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, Dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzof Enone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, and the like. These may be used alone or in combination of two or more, and the amount thereof is usually selected in the range of 0.2 to 15 parts by weight with respect to 100 parts by weight of urethane acrylate.

Conventionally, an antireflective film having antireflective performance has been proposed by laminating a low refractive index layer on the hard coat layer 4, but the protective film X of the present invention prevents reflection of the hard coat layer 4. It is preferable to have performance. If a low refractive index layer or the like is provided separately from the hard coat layer 4, the entire protective film X becomes thick, and the property capable of correcting the positional deviation decreases while being stuck on the adherend of the protective film X, This is because the protective film X is more expensive than necessary.

As a method of giving the hard coat layer 4 anti-reflection performance, a method of containing particles in the hard coat layer 4 is most preferable. By including particles in the hard coat layer 4, antireflective performance can be added to the hard coat layer 4 and scratch resistance and antireflective performance can be achieved only with the thin hard coat layer 4, so the entire protective film X is It does not become thick, and the nature which can correct a position gap hardly falls, as it is stuck on the adherend of protective film X.

(particle)
The particles contained in the hard coat layer 4 may be any particles as long as they can satisfy the transparency required for the hard coat layer 4, but both antireflective performance and transparency of the hard coat layer can be compatible. From the point of point of view, it is preferable to use either acrylic particles or silica particles, or a combination of these. The average particle diameter of the particles contained in the hard coat layer 4 is preferably 1 μm or more and 5 μm or less. When the average particle size is smaller than 1 μm, the antireflective effect is reduced. If it exceeds 5 μm, the hard coat layer 4 can not obtain sufficient transparency. The content of particles in 100 parts by weight of the hard coat layer 4 is preferably 5 parts by weight or more and 14 parts by weight or less. When the amount is less than 5 parts by weight, sufficient antireflection performance can not be obtained, and when the amount exceeds 14 parts by weight, sufficient transparency of the hard coat layer 4 can not be obtained.

The hard coat layer 4 may be a thermoplastic polymer, an antifoaming agent, a coatability improver, a thickener, a surfactant, an organic lubricant, an antioxidant, an ultraviolet absorber, to the extent that hard coat properties are not significantly impaired. It may contain a foaming agent, a dye, a pigment, an antistatic agent and the like.

When the protective film X is attached to a touch panel or the like, the separator A1 is peeled off from the silicone adsorption layer 2, and the silicone adsorption layer 2 is attached to the surface of the touch panel or the like.

Hereinafter, the present invention will be described in detail by way of examples and comparative examples, but the present invention is not limited to the following examples. In the Examples and Comparative Examples, "parts" are by weight unless otherwise specified.

As the TPU substrate 3, a substrate A with a thickness of 60 μm, a substrate B with a thickness of 80 μm, a substrate B with a thickness of 100 μm, and a substrate C with a thickness of 100 μm made by Nippon Matai Co., Ltd. Higres (a registered trademark) Substrate D with a thickness of 100 μm of DUS 451, Substrate E with a thickness of 50 μm with a Hydres (registered trademark) DUS 501, a substrate E with a thickness of 150 μm produced by the following method, and a substrate with a thickness of 160 μm produced by the following method The material G was prepared.

(Polymer polyol H)
A polycarbonate diol (hydroxyl number = 112.2 mg KOH / g) with a number average molecular weight of 1,000 was obtained by the deethanolation reaction (condensation reaction) of 3 methyl 1,5 pentanediol and diethoxy carbonate as high molecular weight polyol H. .

(Diol J)
As diol J, 1,9-nonanediol was prepared.

(Organic diisocyanate K1, K2)
An adduct of hexamethylene diisocyanate as K2 and hexamethylene diisocyanate mixed with 1,3 butanediol as K2 (as the molar ratio is hexamethylene diisocyanate / 1,3 butanediol = 2/1, Were prepared).

(TPU base material F)
Polymer polyol H (501.90 kg) heated to 70 ° C. and zirconium acetylacetonate catalyst (0.03 kg) were mixed uniformly, and this was heated to 60 ° C. with diol J (201.07 kg) heated to 60 ° C. A homogeneous mixture of organic diisocyanates K1 (289.59 kg) and K2 (7.42 kg) was stirred and mixed at a weight ratio in the above-mentioned parenthesis using a mixing and discharging device, and this mixture was poured into a stainless steel container. Thereafter, curing was carried out for 16 hours under an atmosphere of 85 ° C., and after cooling to room temperature, a massive thermoplastic polyurethane resin was obtained. The mass was pulverized into flakes using a pulverizer and processed into pellets by a single screw extruder. The obtained pellet is dewatered and dried, supplied to another single-screw extruder, melt-kneaded, extruded into a sheet form with a T-die at the tip of the extruder, cooled in contact with a cooling roll having a surface temperature of 30 ° C. , To protect the exposed surface of the TPU substrate, take up a 150 μm thick TPU substrate F by winding it while sticking together a PET film (Lumirror (registered trademark) 50 μm thick) made on the exposed surface of the TPU substrate. Made.

(TPU base material G)
Polymer polyol H (402.18 kg) heated to 70 ° C. and zirconium acetylacetonate catalyst (0.03 kg) were mixed uniformly, and this was heated to 60 ° C. with diol J (257.80 kg) and 60 ° C. A homogeneous mixture of organic diisocyanates K1 (331.50 kg) and K2 (8.49 kg) was stirred and mixed at a weight ratio in the above-mentioned parenthesis using a mixing and discharging device, and this mixture was poured into a stainless steel container. Thereafter, curing was carried out for 16 hours under an atmosphere of 85 ° C., and after cooling to room temperature, a massive thermoplastic polyurethane resin was obtained. The mass was pulverized into flakes using a pulverizer and processed into pellets by a single screw extruder. The obtained pellet is dewatered and dried, supplied to another single-screw extruder, melt-kneaded, extruded into a sheet form with a T-die at the tip of the extruder, cooled in contact with a cooling roll having a surface temperature of 30 ° C. , To protect the exposed surface of the TPU substrate, a 160 μm-thick TPU substrate G is obtained by winding up a PET film (Lumirror (registered trademark) 50 μm thick) attached to the exposed surface of the TPU substrate. Made.

(Anchor layer 4A)
The materials shown in Table 1 were mixed and stirred in the amounts shown in Table 1 to prepare an anchor layer 4A coating liquid. The anchor layer 4A coating liquid is coated and dried on the TPU base material 3 so that the thickness after drying is 1.0 μm to the TPU base material of each example and comparative example shown in Tables 3 to 5 The anchor layer 4A was laminated on the About TPU base material 3 in which PET film was stuck on both sides, it passed paper to a coating machine in the state where only PET film of a side which coats anchor layer 4A was exfoliated. This is because the strength of the TPU base material alone is weak, and there is a possibility that the TPU base material may extend during traveling in a coating machine.

(Water dispersion of polyester polyol A)
An aqueous dispersion of polyester polyol A used for the anchor layer 4A coating liquid was produced by the method shown below.

  Distillation pipe, nitrogen inlet pipe, thermometer, four-necked flask equipped with a stirrer 854 parts of dimethyl terephthalate, 355 parts of 5-sodium sulfoisophthalic acid, 186 parts of ethylene glycol, 742 parts of diethylene glycol, as a reaction catalyst Then, add 1 part of zinc acetate, raise temperature from 130 ° C to 170 ° C over 2 hours, carry out transesterification, add 730 parts of isophthalic acid and 1 part of antimony trioxide, and add 2 hours from 170 ° C to 200 ° C. The temperature was raised to carry out the esterification reaction. Then, the temperature was raised gradually and the pressure was reduced gradually, and finally the polycondensation reaction was carried out at a reaction temperature of 250 ° C. and a degree of vacuum of 5 mmHg or less for 1 hour to obtain a polyester polyol A.

  25 parts of the obtained polyester polyol A was charged in a mixed solution of 15 parts of isopropanol and 60 parts of ion-exchanged water and stirred at 70 to 80 ° C. for 3 hours to obtain an aqueous dispersion of polyester polyol A having a solid content concentration of 25%. .

(Hard coat layer 4)
Using the urethane acrylate and particles shown in Table 2, the hard coat coating liquid is adjusted to have the compounding ratio shown in Table 2 as the solid content ratio of the hard coat layer, and Examples and Comparative Examples shown in Tables 3 to 5 The hard coat coating liquid of Table 2 is applied and dried on the anchor layer 4A coated on the TPU substrate of the above, and then ultraviolet rays of 500 mj / cm ² of accumulated light quantity are irradiated to cure the coating, and A hard coat layer having a thickness shown in 3 to 5 was formed.

(Anchor layer 2A)
(Polyester resin)
36.0 molar parts of terephthalic acid (TPA) as polyvalent carboxylic acid component, 4.0 molar parts of adipic acid (ADA), 36.0 molar parts of ethylene glycol (EG) as polyhydric alcohol component, neopentyl glycol The reaction vessel is charged with 11.5 parts by mole of NPG and 6.0 parts by mole of bisphenol A / ethylene oxide adduct as raw material components in a reaction vessel, and the esterification reaction is performed under a nitrogen atmosphere at a pressure of 0.3 MPa and a temperature of 260 ° C. for 3.5 hours Did. 2.5 × 10 ^-4 mol of antimony trioxide / 1 mol of polyvalent carboxylic acid component is added to the obtained esterified product, the pressure is reduced to 0.5 hPa, and a polycondensation reaction is carried out at 280 ° C. for 3 hours to obtain a polyester resin. The Next, 5.5 mol parts of trimellitic anhydride (TMA) and 1.0 mol part of isophthalic acid (IPA) are added as a depolymerization agent, and depolymerization is carried out at 250 ° C. for 2 hours under normal pressure to obtain terephthalic acid ( TPA) / adipic acid (ADA) / trimellitic anhydride (TMA) / isophthalic acid (IPA) / ethylene glycol (EG) / neopentyl glycol (NPG) / bisphenol A / ethylene oxide adduct = 36.0 / A polyester resin of 4 / 5.5 / 1.0 / 36.0 / 11.5 / 6.0 (molar ratio) was obtained. The above polyester resin was dissolved in an aqueous solution containing ammonia and an aqueous solution equivalent to 5% of butyl cellosolve to prepare an aqueous solution of 20% polyester resin, and the solution was stirred at a rotational speed of 7,000 rpm. Next, hot water was passed through a jacket of a stirrer and heated, and the system temperature was maintained at 73 to 75 ° C. and stirred for 60 minutes. Thereafter, cold water was poured into the jacket, and the rotational speed of the stirring blade was lowered to 5,000 rpm, and the mixture was cooled to room temperature (about 25 ° C.) while stirring to obtain an aqueous polyester resin solution (solid content 20% by weight). The acid value of the polyester resin was 99 mg KOH / g. The acid value of the resin was determined by titrating an aqueous solution of acid value polymer with 1/10 N KOH aqueous solution using phenolphthalene as an indicator to neutralize 1 g of polymer. The number of mg was determined.

 After adding 90 parts by weight of water and 50 parts by weight of the polyester resin solution (solid content 20% by weight) of the above production example and sufficiently stirring and mixing with a high speed mixer, 50 parts by weight of methanol is gradually added while stirring to obtain an anchor layer. It was set as 2A coating liquid. The remaining PET film is peeled off from the TPU base material of each of the Examples and Comparative Examples coated with the hard coat layer 4 described above, and the anchor layer 2A coating liquid is applied on the surface of the TPU base material 3 from which the PET film is peeled. Coating and drying were performed to form an anchor layer 2A having a thickness of 0.4 μm.

(Silicone adsorption layer 2)
After applying the silicone adsorption layer coating liquid shown in Tables 3 to 5 with an application thickness of 20 μm (after drying) on the above anchor layer 2A in an environment of 23 ° C. and 50% RH, the temperature is 150 ° C. in an oven. The silicone adsorption layer 2 was obtained by crosslinking for 100 seconds.

(Separator A1)
In order to protect the surface, a PET film (Lumirror (registered trademark) 50 μ thick) was attached to the silicone adsorption layer as a separator A1.

  The evaluation result of each Example and a comparative example is shown to Tables 3-5, 6 and 7, and each evaluation method is shown below.

(Evaluation method)
(Method of measuring gel fraction of adsorption layer)
The gel fraction of the silicone adsorption layer which comprises the protective film of this invention is measured in the following procedures. First, after applying the components of the silicone adsorption layer coating liquid of each Example and Comparative Example on a 50 μm thick PET sheet with a coating thickness of 20 μm (after drying), it is crosslinked at 150 ° C. for 100 seconds in an oven , To obtain a silicone adsorption layer sample. The obtained silicone adsorption layer sample is cut into a predetermined size to form a test piece, and the weight of the adsorption layer laminated on the test piece is measured (the weight is referred to as G1). Next, the test piece is immersed in 50 ml of toluene and left at 25 ° C. for 1 day. Subsequently, the test piece and the residue obtained by filtering the toluene solution are dried at 105 ° C. for 2 hours, and the dry weight of the adsorption layer laminated on the test piece and the dry weight of the residue obtained by filtering the toluene solution are measured. (The total weight is taken as G2.) Then, it calculates by gel fraction = (G2 / G1) x100. The measurement results are shown in Tables 3 to 5.

(Indentation creep of silicone adsorption layer)
The indentation creep CIT of the silicone adsorption layer was determined using a microhardness tester (Fisher scope H100C, manufactured by Fischer Inc.) in accordance with ISO 14577-1.
That is, when the test load is kept constant and the indenter is pushed into the material surface using a microhardness tester, the total mechanical work amount Wtotal of the depression shown during the pressing work is only one as the plastic deformation work amount Wplast of the depression. Only the department is consumed. On unloading of the test load, the remaining part is released as the elastic return deformation work Welast of the recess. If this mechanical work is defined as W = ∫Fdh, the relationship is as follows. The measurement results are shown in Tables 3 to 5.
CIT [%] = Welast / Wtotal
However, Wtotal = Welast + Wplast
<Measurement conditions>
Indenter: Square vertical diamond indenter initial load of facing angle 136 ° Initial load: 0 mN
Indented maximum load: 20mN (constant load)
Maximum load arrival time: 0.25 to 10 sec
Maximum load holding time: 5 sec
Loading time: 0.25 to 10 sec
Measurement temperature: 25 ° C

(TPU, tensile strength of thermoplastic urethane elastomer substrate)
Test pieces were punched out of each TPU base according to JIS K 7161, and tensile strength was measured using a tensile tester (model autograph DCS-500, manufactured by Shimadzu Corporation). The measurement results are shown in Tables 3 to 5.

(Position shift adjustment)
The protective film of each Example and Comparative Example was cut into a shape of 100 mm in length × 25 mm in width as a sample. The separator A1 was peeled off from the sample under an environment of 23 ° C. and 50% RH, and the exposed silicone adsorption layer was attached to a fluoroglass so as to prevent air from entering, and was crimped once with a 2 kg roll. Subsequently, the displacement glass was attached to a sample and allowed to stand under an atmosphere of 23 ° C. and 50% RH for 24 hours, and then the positional deviation adjustment evaluation was performed. As shown in FIG. 2, the corner of the sample was pressed with a finger for 30 seconds inside the middle direction of the two sides constituting the corner of the sample, and the distance the corner of the sample moved was measured. In the measurement, a mark is placed on the surface of the fluorine glass of the corner portion of the sample before movement, and the distance between the corner of the sample after movement and the marked position is measured. For measurement of the distance, a measuring microscope MM-800 manufactured by Nikon Corporation was used. The measurement is carried out for the first time in the order of Comparative Example 1 to Comparative Example 5 following Example 1 to Example 10, and the second time is the reverse of the first time in Comparative Example 5 to Comparative Example 1 to Example 10 It implemented in order of Example 1, and evaluated by the average value of 2 times. The evaluation results are shown in Table 6 and Table 7.
◎: 2 mm or more of misalignment could be adjusted.
○: 1 mm or more and less than 2 mm of positional deviation could be adjusted.
X: positional deviation adjustment was less than 1 mm.

(Removable)
The protective film of each Example and Comparative Example was cut into a shape of 100 mm in length × 25 mm in width, and used as a sample. The separator A1 was peeled off from the sample under an environment of 23 ° C. and 50% RH, and the exposed surface of the silicone adsorption layer 2 was attached to the polished stainless steel plate (SUS plate), and was crimped once with a 2 kg roll. The sample was left to stand in an atmosphere of 120 ° C. for 24 hours and further left to stand in an atmosphere of 23 ° C. for 1 hour in a state where the sample was attached to a SUS plate, and the sample was peeled off in the following procedure. The end of the sample in the longitudinal direction was peeled off and turned back 180 degrees, and the sample was peeled off at a speed of 300 mm per minute in the direction in which the end was turned back, and contamination of the SUS plate surface was visually evaluated according to the following criteria. The evaluation results are shown in Tables 6 and 7.
◎: Contamination can not be confirmed at all on the SUS plate. Particularly good ○: Almost no contamination can be confirmed on the SUS plate. Good :: The SUS plate was slightly contaminated. There is no problem in practical use ×: Significant contamination remained on the SUS plate. Not practical

(Dent dent)
The test was conducted using a pencil hardness tester. Specifically, when the tester is positioned horizontally, JIS K5600-5-II is set except that the tester is set to apply a load of 1000 g to the tip of the pencil whose pencil hardness is "H". The test was performed in accordance with 4. After the test, those with no noticeable dents were evaluated as ◎, those with dents as ○, and those with noticeable dents as ×. The evaluation results are shown in Tables 6 and 7.

It is a schematic diagram which shows the laminated constitution of the protective film X of embodiment of this invention. It is a schematic diagram showing the method of position shift adjustment evaluation of this invention.

X: Protective film 1: Separator A
2: Silicone adsorption layer 2A: anchor layer 3: TPU substrate 4A: anchor layer 4: hard coat layer

Claims (5)

  A silicone adsorption film in which a silicone adsorption layer is laminated on a thermoplastic urethane elastomer substrate directly or through another layer, wherein the silicone adsorption layer has two or more alkenyl groups in one molecule. The silicone composition comprising siloxane and organohydrogenpolysiloxane is cured by an addition reaction, and the silicone adsorption layer further comprises an MQ resin in an amount of 37% to 52% by weight based on the solid content of the silicone adsorption layer. The thermoplastic urethane elastomer base material has a tensile strength of 56 MPa to 71 MPa, and the thermoplastic urethane elastomer base material has a tensile strength of 56 MPa or more and 71 MPa or less, directly or via another layer on the surface opposite to the surface on which the silicone adsorption layer is laminated. A hard coat layer is laminated, and the hard coat layer is made of urethane acrylate. And component silicone adsorbent film thickness of the hard coat layer is 0.5μm or more 5.0μm or less. The diorganopolysiloxane is a linear diorganopolysiloxane having a vinyl group at both ends, a linear diorganopolysiloxane having a vinyl group at both ends and a side chain, and a branched group having a vinyl group at only the end. The silicone adsorption film according to claim 1, which is at least one selected from diorganopolysiloxanes and branched diorganopolysiloxanes having a vinyl group at the terminal and side chains.   The silicone adsorption film according to claim 1 or 2, wherein the thermoplastic urethane elastomer base material has a thickness of 50 μm to 150 μm. The silicone adsorption film according to any one of claims 1 to 3, wherein a gel fraction of the silicone adsorption layer is 45% or more and 62% or less. The silicone adsorption film according to any one of claims 1 to 4, wherein indentation creep of the silicone adsorption layer is 4.1% or more and 8.0% or less.

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