JP2017170671A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film having excellent abrasion resistance, in particular, excellent resistance to repeated abrasion while being a thin film.SOLUTION: There is provided a laminated film having a surface layer 8 on at least one side of a support substrate 10, which satisfies the following conditions. The condition 1: the surface layer 8 has an indentation elastic modulus Eof 1500 MPa or less. The condition 2: the support substrate 10 is a polyester film having a polyester A layer 8 and a polyester B layer 9 and the B layer 8 satisfies at least one of the following (A) or (B). (A) The diol component of a polyester constituting the B layer 8 contains 60 to 90 mol% of a structural unit derived from ethylene glycol and 10 to 40 mol% of a structural unit derived from the other diols. (B) The dicarboxylic acid component of a polyester constituting the B layer 8 contains 60 to 90 mol% of a structural unit derived from terephthalic acid and 10 to 40 mol% of a structural unit derived from the other dicarboxylic acids.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a laminated film having excellent scratch resistance, particularly excellent repeated scratch resistance.

  In recent years, plastic films provided with a surface layer made of a synthetic resin or the like have been used for the purpose of protecting the surface of optical materials such as color filters, flat panel displays, and touch panels (for preventing scratches and imparting antifouling properties). .

  Since these surface layers require scratch resistance as an important characteristic from the viewpoint of surface protection, in general, various prepolymers such as organosilanes and polyfunctional acrylics described in Non-Patent Document 1 are used. The coating composition containing an oligomer or the like is coated, dried, heated, or UV cured to form a “high crosslink density material”, or an “organic-inorganic hybrid material” combined with various surface-modified fillers. Scratch resistance is imparted by using a so-called “hard coat material” with increased surface hardness.

  On the other hand, the surface layer is required to have scratch resistance as an essential characteristic from the viewpoint of surface protection, and various characteristics such as chemical resistance, oil resistance, moldability, etc., and the entire material is a thin film depending on the application. It is required to be. Especially for thin film materials, the rigidity of the base material is reduced, so it is easy to cause “cracking” or “peeling” against deformation by simply hardening the coating film. And a thin film are required.

  On the other hand, Patent Documents 1 and 2 propose a film using a so-called “self-healing material” that repairs scratches on the surface by deformation of the elastic recovery range of the material of the surface layer and achieves scratch resistance. Furthermore, Patent Document 3 discloses that “at least one resin (A) selected from an epoxy resin, an oxetane resin, and a vinyl ether resin, a polyol (B) having a number average molecular weight of 400 or more, and an active energy ray-sensitive catalyst (C The polyol (B) is selected from the polyol (B1), the polycarbonate polyol (B2), the polyester polyol (B3), and the polyether polyol (B4) having a main chain composed of a carbon-carbon bond. An active energy ray-curable coating agent, characterized in that it is at least one polyol prepared. " It has been.

Plastic Hard Coat Applied Technology CM Publishing Co., Ltd. 2004

International Publication No. 2011/136042 Japanese Patent Laid-Open No. 11-228905 JP 2007-284613 A

  However, a molded body using the “hard coat material” for the surface layer is often scratched in daily life and has a poor appearance despite the extremely high surface hardness. As a result, it was found that the surface of the “hard coat material” is high in hardness, but if the surface is repeatedly rubbed with a soft cloth or the like, fine scratches are generated on the surface and the surface becomes cloudy.

  On the other hand, when the present inventors confirmed the materials proposed in Patent Documents 1 to 3, it is difficult to be scratched in daily life, and the wound is recovered by the self-repair function even after repeated rubbing. It was found that the scratch resistance equal to or higher than that of the hard coat material was obtained.

  However, it has been found that when the support substrate or the surface layer is made thin, the surface layer may be damaged when it is repeatedly rubbed, or the surface layer may be peeled off as a result.

  Accordingly, an object of the present invention is to provide a laminated film that is excellent in scratch resistance, particularly repeated scratch resistance, while being a thin film.

In order to solve the above-mentioned problems, the present inventors have intensively studied and as a result, completed the following invention. That is, the present invention is as follows.
<1>
A laminated film having a surface layer on at least one of the supporting substrates, wherein the following conditions 1 and 2 are satisfied:
Condition 1: Indentation elastic modulus _{EIT of the} surface layer is 1,500 MPa or less.
Condition 2: The support substrate is a polyester film having a polyester A layer and a polyester B layer, and the polyester B layer satisfies at least one of the following (A) or (B).
(A) About the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is contained in an amount of 60 mol% to 90 mol%, and the structural unit derived from other diol is contained in an amount of 10 mol% to 40 mol%. Become.
(B) About the dicarboxylic acid component of the polyester constituting the polyester B layer, 60 to 90 mol% of structural units derived from terephthalic acid, and 10 to 40 mol% of structural units derived from other dicarboxylic acids Do it.
<2>
The laminated film according to <1>, wherein the following conditions 3 and 4 are satisfied.
Condition 3: The following equation holds for the thickness T _{s of the} surface layer and the thickness T _t of the laminated film.
0.25 ≦ T _s / T _t ≦ 0.80
Condition 4: The following equation holds for the contact rigidity S _{s of the} surface layer and the contact rigidity S _b of the support base.
S _s N / mm <S _b N / mm ≦ 5.0 N / mm
<3>
The laminated film according to <1> or <2>, wherein the following condition 5 is satisfied.
Condition 5: contact stiffness _{S s} of the surface layer is 2.0 N / mm or less.
<4>
The laminated film according to any one of <1> to <3>, wherein the following condition 6 is satisfied.
Condition 6: The following formula is established for the contact stiffness S _{s of the} surface layer and the contact stiffness S _b of the support substrate.
0.35 ≦ S _s / S _b
<5>
The laminated film according to any one of <1> to <4>, wherein the following condition 7 is satisfied.

Condition 7: The thickness T _{t of the} laminated film is 80 μm or less.
<6>
The laminated film according to any one of <1> to <5>, wherein the following condition 8 is satisfied.
Condition 8: Retardation in the thickness direction of the laminated film is 1,000 nm or less.

  According to the present invention, it is possible to obtain a laminated film having good scratch resistance, in particular, repeated scratch resistance.

It is an example of the data obtained by a nano indenter. This is an example where the surface layer is composed of one layer. This is an example where the surface layer is composed of two layers. It is sectional drawing which shows an example of the formation method of the surface layer in this invention. It is sectional drawing which shows an example of the formation method of the surface layer in this invention. It is sectional drawing which shows an example of the formation method of the surface layer in this invention.

  Before describing the embodiments of the present invention, problems of the prior art, that is, optical characteristics, scratch resistance, particularly repeated scratch resistance, will be considered from the viewpoint of the present inventor.

[Comparison between the present invention and the prior art]
First, the reason why the “hard coat material” described in Non-Patent Document 1 cannot satisfy the scratch resistance, particularly the repeated scratch resistance is that the “hard coat material” is designed to have a very high surface hardness in order to impart scratch resistance. ing. This effect shows scratch resistance against external stress under low load, but the scratch resistance is insufficient against external stress under high load. This is because the surface hardness is extremely high, so there is almost no room for deformation with respect to the load, and stress concentration occurs in some places. Therefore, the scratch resistance is insufficient for high loads. It was. Further, as described above, since the surface hardness is extremely high, it has been found that the force of indentation or impact due to an external load propagates to the member to be protected and is destroyed. It was also found that the “hard coat material” itself was destroyed (cracked and cracked). From the above, it is considered that the repeated scratch resistance was insufficient.

  In addition, the reason why the conventional self-healing materials described in Patent Document 1 to Patent Document 3 cannot satisfy the scratch resistance, in particular, the repeated scratch resistance is that Self-healing properties are obtained by reducing the density of the crosslinked structure. However, this was focused only on the mechanical properties of the self-healing material layer, that is, the surface layer, so that the difference in mechanical properties with the support substrate increased by the amount of flexibility of the surface layer, and when subjected to a vertical load. Stress concentration at the interface between the surface layer and the supporting substrate. As a result, the unacceptable vertical load is propagated to the member to be protected and / or the surface layer and the supporting base material are destroyed, and the repeated abrasion resistance is not sufficient.

  Therefore, the present inventors proceeded with the examination of scratch resistance required for optical applications (display members, etc.), particularly repeated scratch resistance, and viscoelastic characteristics, that is, elastic modulus and contact rigidity, as the mechanical characteristics of the surface layer, Attention was focused on the contact rigidity, which is a viscoelastic property, and the thickness ratio of the surface layer to the support substrate as the mechanical properties of the support substrate. The following are described in order.

  When the surface layer is externally loaded, its mechanical response depends on the viscoelastic properties described above. In particular, the elastic modulus of the surface layer is important from the viewpoint of scratch resistance. When the elastic modulus of the surface layer is a certain value or less, the surface layer is deformed following the load when an external load is applied, so that the load portion can be converted “from point to surface”. As a result, the load per unit area can be reduced. Further, since the elastic modulus of the surface layer is low, it can return to its original shape after being deformed, that is, it can be self-repaired. On the other hand, there is a lower limit to the elastic modulus at which the above effect can be obtained. When the elastic modulus is extremely low, the amount of deformation becomes excessive with respect to the external load, resulting in a so-called “resin flowing state”. In such a case, the amount of deformation of the surface layer exceeds the limit that can be self-repaired, resulting in insufficient scratch resistance.

  From the above, it is preferable to lower the elastic modulus of the surface layer within the range of the lower limit value or more, because the scratch resistance of the surface layer can be enhanced by the above-described effects.

  Specifically, it is preferable that the indentation elastic modulus of the surface layer measured with a nanoindenter is in a specific range.

  Furthermore, in analyzing the scratch resistance and repeated scratch resistance of the laminated film, attention was paid to the characteristics of the supporting substrate. Conventionally, in the case of a laminated film having a surface layer as in the present application, attention has often been paid only to the design of the surface layer in improving the scratch resistance and repeated scratch resistance. However, as a result of the analysis, when the laminated film receives external force, the surface layer and the supporting substrate are deformed and internal stress is generated at the same time. Therefore, the surface layer and the supporting substrate need to be considered together. It was.

  The above is particularly important in the technology proposed by the present application for reducing the elastic modulus of the surface layer and improving the scratch resistance and repeated scratch resistance. The reason for this is that the surface layer follows and deforms against external forces to reduce the load, and is relatively affected by the characteristics of the supporting base material compared to conventional hard coat materials. .

  Particularly important as the characteristics of the support substrate are the relationship of the thickness to the surface layer, the mechanical properties of the surface layer, specifically the relationship of the contact rigidity.

  Regarding the thickness of the support substrate relative to the surface layer, this is to keep the thickness ratio of the surface layer in the entire laminated film at a certain level or more, and when the surface layer receives an external force, the entire laminated film receives the load and laminates it. The load can be reduced as a whole film. This effect not only reduces the load on the surface layer itself, but also has the effect of suppressing the interface breakdown between the surface layer and the supporting substrate, and as a result, the scratch resistance and repeated scratch resistance of the laminated film can be improved. .

Specifically, it is preferable that the ratio between the thickness T _{s of the} surface layer and the thickness T _t of the laminated film be in a specific range.

  Next, the contact rigidity with respect to the surface layer of the supporting base material influences when the surface layer receives an external force, similarly to the thickness ratio described above. The contact rigidity represents a characteristic that absorbs a load when an external force (particularly a vertical load) is applied, and the characteristic that absorbs an external force is improved as the contact rigidity is lower. Here, the present inventors not only lower the contact rigidity of the surface layer but also make the difference between the contact rigidity of the surface layer and the supporting substrate within a certain range so that the laminated film continuously receives external force. It has been found that the effect is improved and the scratch resistance and repeated scratch resistance of the laminated film can be improved.

Specifically, it is preferable that the contact rigidity S _s of the surface layer is in a specific range, and the ratio of the contact rigidity S _s of the surface layer and the contact rigidity S _b of the support base is in a specific range.

  Moreover, it becomes possible to control the contact rigidity of a support base material because resin which comprises a support base material contains specific polyester.

[Mode of the Invention]
Hereinafter, embodiments of the present invention will be specifically described.

  In order to satisfy the above-mentioned problems, that is, scratch resistance, particularly, repeated scratch resistance, the laminated film of the present invention is a laminated film having a surface layer on at least one of the supporting substrates, and the following conditions 1 and 2 It is preferable to satisfy.

Condition 1: Indentation elastic modulus _{EIT of the} surface layer is 1,500 MPa or less.

Condition 2: The support substrate is a polyester film having a polyester A layer and a polyester B layer, and the polyester B layer satisfies at least one of the following (A) or (B).
(A) About the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is contained in an amount of 60 mol% to 90 mol%, and the structural unit derived from other diol is contained in an amount of 10 mol% to 40 mol%. Become.
(B) About the dicarboxylic acid component of the polyester constituting the polyester B layer, 60 to 90 mol% of structural units derived from terephthalic acid, and 10 to 40 mol% of structural units derived from other dicarboxylic acids Do it.

From the viewpoint of scratch resistance, particularly repeated scratch resistance, the laminated film of the present invention preferably has an indentation elastic modulus _EIT in the surface layer of 1,500 MPa or less, more preferably 1,000 MPa or less, Particularly preferably, it is 500 MPa or less. By setting the indentation elastic modulus E _IT within a specific range, it is possible to increase the scratch resistance, particularly the repeated scratch resistance.

It is preferable that the indentation elastic modulus _EIT measured by the nanoindenter is in a specific range, because the above-described effects improve the scratch resistance, particularly the repeated scratch resistance. If the indentation elastic modulus E _IT is high, the rigidity is improved, but if it is excessively high, the surface layer may break, and the upper limit is considered to be about 1,500 MPa. On the other hand, when the indentation elastic modulus _EIT is excessively low, the rigidity of the surface layer is lowered, so that the surface layer may be destroyed due to the above-mentioned effects, and the surface layer becomes sticky and inappropriate. Therefore, the lower limit is considered to be about 100 MPa.

In order to set the indentation elastic modulus _EIT of the surface layer to 1,500 MPa or less, for example, the resin contained in the surface layer can be selected by selecting a material exemplified below.

From the viewpoint of scratch resistance, in particular, repeated scratch resistance, the laminated film of the present invention is a polyester film in which the supporting substrate has a polyester A layer and a polyester B layer, and the polyester B layer is the following (A) or (B): It is preferable to satisfy at least one of the above.
(A) About the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is contained in an amount of 60 mol% to 90 mol%, and the structural unit derived from other diol is contained in an amount of 10 mol% to 40 mol%. Become.
(B) About the dicarboxylic acid component of the polyester constituting the polyester B layer, 60 to 90 mol% of structural units derived from terephthalic acid, and 10 to 40 mol% of structural units derived from other dicarboxylic acids Do it.

  These details and the polyester A layer and the polyester B layer will be described later.

  It is preferable that the support base material is composed of the polyester A layer and the polyester B layer because the contact rigidity of the support base material can be lowered, and the above-described effects can improve the scratch resistance and the repeated scratch resistance.

  Furthermore, it is preferable that the laminated film satisfies the following conditions 3 and 4 from the viewpoint of scratch resistance, particularly, repeated scratch resistance.

Condition 3: The following equation holds for the thickness T _{s of the} surface layer and the thickness T _t of the laminated film.
0.25 ≦ T _s / T _t ≦ 0.80
Condition 4: The following equation holds for the contact rigidity S _{s of the} surface layer and the contact rigidity S _b of the support base.
S _s N / mm <S _b N / mm ≦ 5.0 N / mm
A method for measuring the contact stiffness will be described later.

From the viewpoint of repeated scratch resistance, the laminated film of the present invention preferably has T _s / T _t of 0.25 or more and 0.80 or less, more preferably 0.30 or more and 0.80 or less, particularly Preferably they are 0.40 or more and 0.80 or less. T _s / T _t is the thickness ratio between the surface layer of the laminated film and the supporting substrate, but it correlates with the response to vertical load. By making T _s / T _t within a certain range, repeated scratch resistance can be achieved. Can be increased.

When T _s / T _t is large, the effect of continuously receiving the vertical load in the entire laminated film is increased due to the above-described effects, and therefore, the repeated scratch resistance is improved, which is preferable. This effect is greater as T _s / T _t is larger, but if it is excessive, there is a limit because the handling property of the laminated film (ease of handling during transportation and use) is deteriorated, and the upper limit is about 0.80. it is conceivable that. On the other hand, if the T _s / T _t ratio is smaller than 0.25, the surface layer-supporting substrate interface of the member to be protected or the laminated film may be destroyed by the vertical load, and the repeated scratch resistance may be reduced.

In order to set T _s / T _t to 0.25 or more and 0.80 or less, it is possible, for example, by selecting a support base material and setting surface layer formation conditions.

From the viewpoint of repeated scratch resistance, it is preferable that “S _s N / mm <S _b N / mm ≦ 5.0 N / mm” is satisfied. The relationship of the contact stiffness has a correlation with the response to the vertical load, and by having the above-mentioned relationship, it is possible to increase the repeated scratch resistance.

When the _{"S s N / mm <S b} N / mm ≦ 5.0N / mm " is satisfied, the effect described above, for continuously receive effective vertical load across the laminated film becomes large, repetitive scratch resistance improvement It is preferable. This effect is greater as _Sb is smaller, but if it is excessive, there is a limit because the handleability of the laminated film (ease of handling during transport or use) may be reduced, and the lower limit is about 1.5. Conceivable. On the other hand, when “S _s N / mm ≧ S _b N / mm” or “S _b N / mm> 5.0 N / mm” is established, the surface layer-supporting base material of the member to be protected or the laminated film by the vertical load The interface may be broken, and the repeated scratch resistance may be reduced.

To the _{"S s N / mm <S b} N / mm ≦ 5.0N / mm ", for example selection of the supporting substrate and be selected from materials which illustrate the resin contained in the surface layer to be described later Is possible.

Furthermore, from the viewpoint of repeated scratch resistance, the laminated film preferably satisfies the following condition 5.
Condition 5: contact stiffness _{S s} of the surface layer is 2.0 N / mm or less.

  A method for measuring the contact stiffness will be described later.

From the viewpoint of repetitive abrasion resistant, laminated films of the present invention is preferably contact stiffness S _s of the surface layer is not more than 2.0 N / mm, more preferably not more than 1.5 N / mm, particularly preferably Is 1.0 N / mm or less. The contact rigidity S _s of the surface layer has a correlation with the response to vertical addition, and by setting the contact rigidity S _s to a specific value or less, it is possible to increase the repeated scratch resistance.

When the contact rigidity S _s is small, the effect of continuously receiving the vertical load with the whole laminated film is increased due to the above-described effect, and therefore, the repeated scratch resistance is improved, which is preferable. The smaller the contact stiffness S _{s, the} greater this effect is. However, when the contact stiffness S _s is extremely small, the stiffness decreases, and the scratch resistance may deteriorate, so the lower limit value is considered to be about 0.1 N / mm. On the other hand, the contact stiffness S _s is the larger than 2.0 N / mm, insufficient effect of enhancing the repetitive scratch resistance, surface layer of the protected member or a laminated film by a vertical load - supporting substrate interface is broken, repeated rubbing Resistance may be reduced.

To the contact stiffness S _s or less 2.0 N / mm is possible by selecting for example from a material illustrating a resin contained in the surface layer to be described later.

Furthermore, from the viewpoint of repeated scratch resistance, the laminated film preferably satisfies the following condition 6.
Condition 6: The following formula is established for the contact stiffness S _{s of the} surface layer and the contact stiffness S _b of the support substrate.
0.35 ≦ S _s / S _b
A method for measuring the contact stiffness will be described later.

From the viewpoint of repeated scratch resistance, the laminated film of the present invention preferably has S _s / S _b of 0.35 or more, more preferably 0.40 or more, and particularly preferably 0.50 or more. . S _s / S _b is the contact rigidity ratio between the surface layer of the laminated film and the supporting substrate, and has a correlation with the response to vertical load. By setting S _s / S _b within a certain range, repeated scratch resistance Can be increased.

When S _s / S _b is large, the effect of continuously receiving the vertical load in the entire laminated film is increased due to the above-described effects, and therefore, the repeated scratch resistance is improved, which is preferable. This effect increases as S _s / S _b increases, but the upper limit is approximately 1.0. On the other hand, when S _s / S _b is smaller than 0.35, the surface layer-supporting substrate interface of the member to be protected or the laminated film is broken by the vertical load, and the repeated scratch resistance may be lowered.

In order to set S _s / S _b to 0.35 or more, for example, it is possible to select a supporting base material and select a resin contained in the surface layer from materials exemplified below.

  Furthermore, from the viewpoint of thinning, the laminated film preferably satisfies the following condition 7.

Condition 7: The thickness T _{t of the} laminated film is 80 μm or less.

T _t is the thickness of the laminated film. The smaller the value, the more the product can be made thinner and lighter.

When _Tt is small, the member and product which use the said laminated film can be reduced in thickness and weight, and it is preferable. This effect is greater as _Tt is smaller. However, when it is extremely small, repeated scratch resistance may be insufficient, and the lower limit is about 5 μm. On the other hand, when _Tt becomes larger than 80 μm, members and products using the laminated film may be thickened or weighted.

In order to set _Tt to 80 μm or less, it is possible to select a support base material and set surface layer formation conditions.

Furthermore, from the viewpoint of optical properties, the laminated film preferably satisfies the following condition 8.
Condition 8: Retardation in the thickness direction of the laminated film is 1,000 nm or less.
A method for measuring retardation will be described later.

  From the viewpoint of optical characteristics, the laminated film of the present invention preferably has a retardation of 1,000 nm or less with respect to the thickness direction of the laminated film, more preferably 100 nm or less. Retardation represents optical properties, and optical quality can be improved by setting retardation within a certain range.

  A small retardation is preferable because the optical quality is improved when used for optical applications (such as a display member) due to the aforementioned effects. The smaller the retardation is, the greater this effect is. However, the lower limit is 0. On the other hand, if the retardation is higher than 1,000 nm, the optical quality when used for optical applications may be lowered.

  In order to set the retardation to 1,000 nm or less, for example, it is possible to select a supporting base material and select a resin contained in the surface layer from materials exemplified below.

[Laminated film and surface layer]
The laminated film of the present invention may be in a planar state or a three-dimensional shape after being molded as long as it has a surface layer exhibiting the above-described physical properties. The number of the surface layers is not particularly limited, and may be formed from one layer or may be formed from two or more layers.

  The thickness of the surface layer is not particularly limited, but the lower limit is preferably 1 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more. Further, the upper limit is preferably 100 μm or less, more preferably 50 μm or less, further preferably 40 μm or less, and particularly preferably 30 μm or less. The thickness of the surface layer can be selected according to the other functions described above.

  In addition to self-repairing and repeated scratch resistance, the surface layer is a subject of the present invention, glossiness, fingerprint resistance, moldability, designability, adhesion durability, antifouling properties, antireflection, antistatic, conductive It may have other functions such as property, heat ray reflection, near infrared absorption, electromagnetic wave shielding, and easy adhesion.

[Supporting substrate]
The resin constituting the supporting substrate used in the laminated film of the present invention may be either a thermoplastic resin or a thermosetting resin, may be a homo resin, may be a copolymer or a blend of two or more types. Good. The resin constituting the supporting base material is preferable if the moldability is good, and a thermoplastic resin is more preferable in that respect. As the support substrate used in the laminated film of the present invention, it is particularly preferable to use a polyester film described later from the viewpoint of optical properties and repeated scratch resistance.

  Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyimide resins, polyester resins, polycarbonate resins, Fluorine such as polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene-6 fluoropropylene copolymer, vinylidene fluoride resin Resins, acrylic resins, methacrylic resins, polyacetal resins, polyglycolic acid resins, polylactic acid resins, and the like can be used. As examples of the thermosetting resin, phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane resin, polyimide resin, silicone resin, and the like can be used. The thermoplastic resin is preferably a resin having sufficient stretchability and followability. The thermoplastic resin is more preferably a polyester resin, a polycarbonate resin, an acrylic resin, or a methacrylic resin from the viewpoint of strength, heat resistance, and transparency.

  The polyester resin in the present invention is a general term for polymers having an ester bond as a main bond chain, and is obtained by polycondensation of an acid component and its ester and a diol component. Specific examples include polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and the like. These may be copolymerized with other dicarboxylic acids and their esters or diol components as acid components or diol components. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferable in terms of transparency, dimensional stability, heat resistance and the like.

  In addition, for the support substrate, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, A dopant for adjusting the refractive index may be added. The support substrate may be either a single layer configuration or a laminated configuration.

  Various surface treatments can be applied to the surface of the support substrate before the surface layer is formed. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Among these, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment are preferred, and glow discharge treatment and ultraviolet treatment are more preferred.

  In addition to the surface layer of the present invention, a functional layer such as an easy-adhesion layer, an antistatic layer, an undercoat layer, and an ultraviolet absorption layer can be provided in advance on the surface of the support substrate. It is preferable to provide a layer.

(Polyester film used for support substrate)
The support substrate in the present invention is a polyester film having a polyester A layer and a polyester B layer, and the polyester B layer is preferably a polyester film satisfying at least one of the following (A) or (B).
(A) About the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is contained in an amount of 60 mol% to 90 mol%, and the structural unit derived from other diol is contained in an amount of 10 mol% to 40 mol%. Become.
(B) About the dicarboxylic acid component of the polyester constituting the polyester B layer, 60 to 90 mol% of structural units derived from terephthalic acid, and 10 to 40 mol% of structural units derived from other dicarboxylic acids Do it.

  The support substrate in the present invention may be a polyester film in which at least one polyester A layer and a polyester B layer satisfying the above-described conditions are included, and layers other than the polyester A layer and the polyester B layer are included. Alternatively, a plurality of polyester A layers and polyester B layers may be included.

  Furthermore, as a polyester film preferably used for the support base material in this invention, it is a laminated polyester film of 10 layers or less which has a polyester A layer and a polyester B layer. In particular, the resin constituting the polyester B layer preferably has a lower melting point than the resin constituting the polyester A layer. Since the resin constituting the polyester B layer has a lower melting point than the resin constituting the polyester A layer, the orientation of the polyester B layer can be easily relaxed in the heat treatment step during film formation, and the retardation can be controlled low. This is preferable because it becomes possible. The melting point in the present invention is an endothermic peak temperature that is manifested by a melting phenomenon when measured with a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min. When polyester resins having different compositions are blended and used as a film, a plurality of endothermic peaks accompanying melting may appear. In such a case, the temperature at which the absolute value of the heat flow is the largest is taken as the melting point. In addition, since the polyester B layer in the present invention has one of the purposes of relaxing the orientation in a heat treatment step or the like during film formation and controlling the retardation low, the crystallinity is low and there is no clear melting point. Polyester is also included.

  The polyester film particularly preferably used in the present invention has a polyester A layer and a polyester B layer having a melting point lower than that of the polyester A layer, and is not particularly limited as long as it is a laminated polyester film of 10 layers or less, and has other layers. However, from the viewpoint of film-forming properties and interlayer adhesion, a configuration in which the polyester A layer and the polyester B layer are alternately laminated is preferable, and the number of layers is 10 layers or less composed only of the polyester A layer and the polyester B layer. A laminated polyester film is preferred.

  The number of layers of the polyester film preferably used in the present invention is preferably 10 or less. When the number of layers to be laminated is more than 10, the thickness of each layer becomes thin, so that the lamination property at the time of film formation is lowered, a flow mark or the like is generated, and the film quality may be lowered. The polyester film preferably used in the present invention can have more polyester A layers when maintaining high dimensional stability while maintaining low retardation, so the number of layers to be laminated is 5 or more. It is preferable to have 9 layers or less. On the other hand, when it is desired to suppress the manufacturing cost while achieving low retardation, the number of layers to be laminated is preferably 2 or more and less than 5 layers.

  The polyester film preferably used in the present invention preferably has a retardation of 1,000 nm or less with respect to the thickness direction of the film. In the present invention, the retardation is calculated from the product of the maximum value of the refractive index difference between two orthogonal directions in the plane of the film and the film thickness, and is specifically sold by Oji Scientific Instruments Co., Ltd. It is assumed that values measured by the phase difference measuring device KOBRA series for measuring retardation using an optical method are used.

  When the polyester film preferably used in the present invention has a retardation value higher than 1,000 nm, an interference color may be produced when applied to an optical member (such as a display), and the optical quality may be lowered. In a biaxially stretched polyester film, stretching in a biaxial direction perpendicular to the production is carried out. In the stretching process, variations in retardation occur in the plane of the film. More specifically, in sequential biaxial stretching that is generally used for biaxially stretched films, stretching in the film longitudinal direction is followed by stretching in the film width direction, and in some cases, heat treatment is then performed. However, in particular, when stretching in the film width direction, a retardation difference occurs in the film width direction due to variations in stress between the film longitudinal direction and the film width direction. Therefore, even if retardation is suppressed at the center in the film width direction, it is generally known that the retardation increases as it approaches the end when viewed in the film width direction. When retardation variation occurs in the width direction of the film as described above, when applied as a large optical member (display, particularly 32 inches or more), variation in retardation occurs in the plane, and interference occurs at a high retardation portion. Color may occur. The polyester film preferably used in the present invention preferably has a film width of 400 mm or more, more preferably 1,000 mm or more, and particularly preferably 1,500 mm or more, from the viewpoint of a large optical member.

  When the polyester film preferably used in the present invention is applied to a large optical member (such as a display), the retardation with respect to the thickness direction of the film surface is less than 750 nm from the viewpoint of suppressing the occurrence of interference color. Preferably, it is more preferably 500 nm or less, and particularly preferably 1 nm or more and 200 nm or less.

  The method for suppressing retardation is not particularly limited as described above. For example, it is a laminated film of 10 layers or less having a polyester A layer and a polyester B layer, and a resin constituting the polyester B layer is a resin constituting the polyester A layer. And a method of relaxing the orientation of the polyester B layer by lowering the melting point. The polyester film of the present invention is preferably a biaxially oriented polyester film from the viewpoints of heat resistance, dimensional stability, and handleability, but as a method for relaxing the orientation of the polyester B layer with a biaxially oriented polyester film, A method in which the stretching temperature is increased and the heat treatment temperature after biaxial stretching is increased is preferred. A biaxially oriented polyester film is a sequential biaxial stretching method in which an unstretched film is stretched in the longitudinal direction and then stretched in the width direction, or stretched in the width direction and then stretched in the longitudinal direction. Stretching can be performed by a simultaneous biaxial stretching method or the like in which the directions are stretched almost simultaneously, but by increasing the stretching temperature, the film becomes difficult to be oriented. Specifically, the stretching temperature in the longitudinal direction is preferably 95 ° C. or higher and 130 ° C. or lower, and more preferably 100 ° C. or higher and 120 ° C. or lower. The stretching temperature in the width direction is preferably 100 ° C. or higher and 150 ° C. or lower.

  Further, the heat treatment temperature after biaxial stretching is preferably carried out at a temperature of (melting point of polyester B layer−10 ° C.) or more and (melting point of polyester B layer + 30 ° C.) or less. By performing the heat treatment in the temperature range as described above, the orientation of the polyester B layer is relaxed and the retardation can be controlled to be low.

  Further, as a method for controlling the retardation to be low, it is preferable to make the longitudinal orientation and the transverse orientation in the biaxial orientation as isotropic as possible. For example, the longitudinal stretching ratio and the stretching ratio in the width direction are the same. A method of obtaining a magnification is preferably used.

  The polyester film of the present invention preferably has a film haze difference (Δhaze) of less than 1 before and after holding the film for 400 hours under conditions of a temperature of 60 ° C. and a humidity of 95%. Even if the optical member (display etc.) using the film of the present invention is exposed to a high temperature and a high humidity by keeping the Δhaze when held at a high temperature and a high humidity for a long time as low as less than 1, Appearance change can be suppressed. As a method of setting the film haze difference (Δhaze) before and after holding the film for 400 hours under the conditions of a temperature of 60 ° C. and a humidity of 95% to be less than 1, the amount of cyclic trimer in the polyester film is determined by As 100 mass%, it is preferable to set it as 1 mass% or less, More preferably, it is 0.9 mass% or less, More preferably, it is 0.85 mass% or less.

  The polyester film preferably used in the present invention preferably has a retardation of 2,000 nm or less with respect to an angle inclined by 50 ° with respect to the plane direction of the film at the center of the film. By controlling the retardation with respect to the angle inclined by 50 ° with respect to the plane direction of the film as low as 2000 nm or less, when viewing an optical member (such as a display) using the laminated film of the present invention, coloring and brightness decrease depending on the viewing angle. Can be suppressed with high accuracy. The retardation with respect to the angle inclined by 50 ° with respect to the plane direction of the film is more preferably 1,500 nm or less, and most preferably 1 nm or more and 1,000 nm or less.

  As a method of setting the retardation for an angle inclined by 50 ° with respect to the plane direction of the film to 2,000 nm or less, any one direction of the plane direction of the film is the direction X, the direction orthogonal to the direction X is the direction Y, and the film thickness When the direction is the direction Z, it is preferable to make the difference between the average refractive index of X and Y of the polyester B layer and the refractive index in the Z direction as small as possible. The polyester film of the present invention is preferably biaxially oriented. However, when biaxially oriented, the refractive index in the film plane is significantly larger than the refractive index in the film thickness direction. For this reason, it is important to lower the refractive index in the film plane while maintaining biaxial orientation. As a method of lowering the refractive index in the film plane, for example, with respect to the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is from 60 mol% to 90 mol%, and the structural unit derived from other diol is used. About the method of making it the structure containing 10 mol% or more and 40 mol% or less, about the dicarboxylic acid component of the polyester which comprises the polyester B layer, the structural unit derived from terephthalic acid is 60 mol% or more and 90 mol% or less, and other dicarboxylic acid origin The method of setting it as the structure containing 10 mol% or more and 40 mol% or less of a structural unit is mentioned.

  About the diol component of the polyester constituting the polyester B layer, it is easy to control the refractive index in the film plane at the time of biaxial orientation by containing 10 mol or more of a diol-derived structural unit other than the structural unit derived from ethylene glycol. Become. Similarly, with respect to the dicarboxylic acid component of the polyester constituting the polyester B layer, by containing 10 mol or more of a structural unit derived from dicarboxylic acid other than the structural unit derived from terephthalic acid, the refractive index within the film plane during biaxial orientation It becomes easy to control low.

  Here, as the structural unit derived from diol other than the structural unit derived from ethylene glycol, for example, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4- Butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4-hydroxyethoxyphenyl) propane, isosorbate, spiroglycol and the like can be mentioned. Among these, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, isosorbate, and spiro glycol are preferably used. These diol-derived structural units may be used alone or in combination of two or more in addition to the ethylene glycol-derived structural unit.

  Examples of the structural unit derived from dicarboxylic acid other than the structural unit derived from terephthalic acid include, for example, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. Structural units derived from aromatic dicarboxylic acids such as 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, adipic acid, suberic acid, sebacic acid, dimer acid , Structural units derived from aliphatic dicarboxylic acids such as dodecanedioic acid and cyclohexanedicarboxylic acid, and ester derivatives thereof. Of these, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and cyclohexanedicarboxylic acid are preferably used. In addition to the structural unit derived from terephthalic acid, these dicarboxylic acid-derived structural units may be used alone or in combination of two or more, and some of the oxyacids such as hydroxybenzoic acid may be used together. Polymerization may be performed.

  The polyester film preferably used in the present invention has an X, Y, Z of the polyester B layer, where an arbitrary direction in the plane direction of the film is a direction X, a direction perpendicular to the direction X is a direction Y, and a film thickness direction is a direction Z. The average value of the refractive index in the direction is preferably 1.51 or more and 1.57 or less. By controlling the average value of the refractive index in the X, Y, and Z directions as low as the above range, the absolute value of the retardation can be easily controlled to be low. Therefore, when applied to an optical member (such as a display), the optical quality is improved. Can be increased.

  More preferably, the average value of the refractive index in the X, Y, and Z directions of the polyester B layer is within the above range. For the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is 65 mol% or more. Less than 85 mol%, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, isosorbate, a method containing a diol-derived structural unit selected from spiroglycol in an amount of 15 mol% to less than 35 mol%, the polyester B layer The structural unit derived from terephthalic acid is 65 mol% or more and less than 85 mol%, and the structural unit derived from isophthalic acid, 2,6-naphthalenedicarboxylic acid or cyclohexanedicarboxylic acid is 15 mol% or more with respect to the structural unit derived from dicarboxylic acid. A method containing less than 35 mol%, However, with respect to the structural unit derived from the diol of the polyester B layer, the structural unit derived from ethylene glycol is 65 mol% or more and less than 85 mol%, among neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, isosorbate, spiroglycol. A method in which a diol-derived structural unit selected from the group consisting of 15 mol% or more and less than 35 mol% is more preferably used.

  The polyester film preferably used in the present invention has a thermal shrinkage rate of 85% or less at 85 ° C. in any one direction X in the film plane in order to reduce warpage when applied to an optical member (display, etc.). It is preferable that When the heat shrinkage rate at 85 ° C. in the X direction is 0.5% or less, when applied to an optical member (such as a display), the film is prevented from shrinking due to the heat applied to the laminated film, and the product warps. Can be suppressed. Similarly, the polyester film of the present invention preferably has a heat shrinkage rate at 85 ° C. in the direction Y orthogonal to the direction X of 0.5% or less.

  The thermal contraction rate at 85 ° C. in the X direction and the Y direction is more preferably 0.3% or less, and most preferably 0.1% or less. As a method for setting the heat shrinkage rate at 85 ° C. in the X direction and the Y direction to 0.5% or less, it is preferable that the number of layers of the polyester A layer and the polyester B layer is 5 or more and 9 or less. Moreover, in the preheating process at the time of extending | stretching in a plane direction (longitudinal direction, width direction), it is preferable to preheat at 85 degreeC conditions for 1 second or more. In order to reduce the thermal shrinkage rate at the target temperature, it is effective to remove the distortion of the polyester film at the target temperature in the preheating step before stretching.

  In the polyester film preferably used in the present invention, it is preferable that the polyester A layer is located in at least one outermost layer, and the plane orientation coefficient of the A layer is larger than 0.11. By adopting the above-described configuration, it is possible to maintain the rigidity of the film at the same time while achieving low retardation, which is preferable because handleability is improved. The plane orientation coefficient of the A layer is more preferably 0.115 or more, and most preferably 0.12 or more. As a method for setting the plane orientation coefficient of the A layer in the above range, the polyester diol component of the polyester A layer contains 95 to 100 mol% of structural units derived from ethylene glycol, and the polyester A layer It is preferable that the structural unit derived from terephthalic acid is contained in an amount of 95 mol% to 100 mol%.

The plane orientation coefficient is the refractive index (nX) in any one direction X in the film plane and the direction Y orthogonal to the direction X using an Abbe refractometer using sodium D line (wavelength 589 nm) as a light source. The refractive index (nY) and the refractive index (nZ) in the thickness direction Z were measured, and the plane orientation coefficient (fn) was calculated from the following formula.
fn = (nX + nY) / 2−nZ.

  In the present invention, when the polyester B layer is composed of the polyester A layer and a resin having a melting point lower than that of the resin constituting the polyester A layer, a plurality of refractive indexes are observed in the X direction, the Y direction, and the Z direction. The For this reason, among the observed refractive indexes, in the X direction and the Y direction, the lowest value is the refractive index of the polyester B layer, the highest value is the refractive index of the polyester A layer, and the lowest value is in the Z direction. The value was the refractive index of the polyester A layer, and the highest value was the refractive index of the polyester B layer.

  In the polyester film preferably used in the present invention, the sum of the layer thicknesses of the A layers / the sum of the layer thicknesses of the B layers is preferably 0.1 or more and 1 or less. The total layer thickness referred to here is obtained for layers made of the same resin by observing the laminated state using a transmission electron microscope (TEM) in a cross section cut out in the center in the width direction of the laminated film. It is the sum total of all layer thicknesses. The smaller the sum of the layer thicknesses of the A layers / the sum of the layer thicknesses of the B layers, the lower the retardation, and the easier it is to control the retardation. Therefore, the sum of the layer thicknesses of the A layers / B layer layers The total thickness is more preferably from 0.1 to 0.5, and most preferably from 0.1 to 0.3.

  In addition, since the retardation is calculated from the product of the maximum value of the refractive index difference between two orthogonal directions in the plane of the film and the film thickness, it is preferable that the film thickness is thin in order to control the retardation low. . For this reason, the polyester film preferably used in the present invention has a thickness of preferably 5 μm or more and 75 μm or less, more preferably 10 μm or more and 50 μm or less, and more preferably 15 μm or more and 45 μm or less from the viewpoints of handleability and low retardation control. Is most preferable.

  Moreover, in order to achieve both low retardation control and rigidity, the thickness of the polyester A layer is preferably less than 3.2 μm. In order to maintain rigidity, the polyester A layer has a higher melting point than the polyester B layer, and the diol component of the polyester constituting the polyester A layer contains 95 to 100 mol% of structural units derived from ethylene glycol, And since it is preferable to contain the structural unit derived from a terephthalic acid about 95 mol% or more and 100 mol% or less about the dicarboxylic acid component of the polyester which comprises the polyester A layer, it is easy to add phase difference compared with the polyester B layer. For this reason, it is preferable to reduce the thickness of the polyester A layer. The thickness of the polyester A layer is more preferably 3 μm or less, and most preferably 1 μm or more and 2.8 μm or less. In addition, when the polyester film preferably used for this invention has two or more polyester A layers, it is preferable that the thickness of the whole polyester A layer shall be less than 3.2 micrometers.

  The polyester film preferably used in the present invention includes various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, a pigment, a dye, an organic or inorganic fine particle, a filler. An agent, an antistatic agent, a nucleating agent, etc. may be added to such an extent that the characteristics are not deteriorated.

[Coating composition]
Although the manufacturing method of the laminated film of the present invention is not particularly limited, the laminated film of the present invention is a step of applying a coating composition to at least one of the above-mentioned supporting substrates, a step of drying or a step of curing as necessary. Can be obtained through Here, the “coating composition” is a liquid composed of a solvent and a solute, and is a material that can be applied to the above-mentioned supporting substrate and volatilized, removed, and cured in a drying process to form a surface layer. Point to. Here, the “type” of the coating composition refers to liquids that are different in part even in the type of solute constituting the coating composition. This solute is a resin or a material that can form them in the coating process (hereinafter referred to as a precursor), particles, and polymerization initiators, curing agents, catalysts, leveling agents, ultraviolet absorbers, antioxidants, etc. Consists of various additives.

  In the laminated film of the present invention, it is preferable to form the surface layer by applying the coating composition A onto a supporting substrate.

[Coating composition A]
The coating composition A is a liquid containing a material suitable for constituting the surface layer of the present invention or a precursor that can be formed, and a resin containing the following segments (1) to (3) as a solute: Or it is preferable that a precursor is included.
(1) A segment containing at least one selected from the group consisting of a polycaprolactone segment, a polycarbonate segment and a polyalkylene glycol segment (2) A urethane bond (3) From a group consisting of a fluorine compound segment, a polysiloxane segment and a polydimethylsiloxane segment A segment containing at least one selected.

  About each segment which resin which comprises A layer in the surface of this surface layer contains, it can confirm by TOF-SIMS, FT-IR, etc.

  Moreover, the mass part of said (1), (2), (3) contained in coating composition A is (1) / (2) / (3) = 95/5/1-50/50/15. Is preferable, and (1) / (2) / (3) = 90/10/1 to 60/40/10 is more preferable. The details of (1), (2), and (3) will be described below.

  The details of the (1) polycaprolactone segment, polycarbonate segment and polyalkylene glycol segment will be described later, but the resin constituting the layer A on the surface of the surface layer has these segments, so that the self-healing property of the surface layer It is possible to improve the scratch resistance and to improve the repeated scratch resistance.

  Although details of the urethane bond will be described later, the toughness of the entire surface layer can be improved when the resin constituting the layer A on the surface of the surface layer has this bond.

  Although details of the fluorine compound segment will be described later, the resin constituting the surface layer contains these, so that molecules exhibiting low surface energy can be present at high density on the outermost surface, and the surface scratch resistance is improved. To do.

[Polycaprolactone segment, polycarbonate segment, polyalkylene glycol segment]
First, the polycaprolactone segment refers to a segment represented by Chemical Formula 1. Polycaprolactone includes those having caprolactone repeating units of 1 (monomer), 2 (dimer), 3 (trimer), and oligomers having caprolactone repeating units of up to 35.

n is an integer of 1 to 35.

  The resin containing the polycaprolactone segment preferably has at least one hydroxyl group (hydroxyl group). The hydroxyl group is preferably at the end of the resin containing the polycaprolactone segment.

  The resin containing a polycaprolactone segment is particularly preferably a polycaprolactone having 2 to 3 functional hydroxyl groups. Specifically, polycaprolactone diol represented by Chemical Formula 2,

Here, m + n is an integer from 4 to 35, m and n are each an integer from 1 to 34, R is C ₂ H ₄ , C ₂ H ₄ OC ₂ H ₄ or C (CH ₃ ) ₃ (CH ₂ ) _2.
Or polycaprolactone triol represented by Chemical Formula 3,

Here, l + m + n is an integer of 3 to 30, l, m and n are each an integer of 1 to 28, R is CH ₂ CHCH ₂ , CH ₃ C (CH ₂ ) ₃ or CH ₃ CH ₂ C (CH ₂ ). ₃
Such as polycaprolactone polyol and polycaprolactone-modified hydroxyethyl (meth) acrylate represented by Chemical Formula 4

Here, n is an integer of 1 to 25, and R can be active energy ray-polymerizable caprolactone such as H or CH ₃ . Examples of other active energy ray-polymerizable caprolactone include polycaprolactone-modified hydroxypropyl (meth) acrylate, polycaprolactone-modified hydroxybutyl (meth) acrylate, and the like.

  Furthermore, in the present invention, the resin containing the polycaprolactone segment may contain (or copolymerize) other segments and monomers in addition to the polycaprolactone segment. For example, a polydimethylsiloxane segment, a polysiloxane segment, or a compound containing an isocyanate compound described later may be contained (or copolymerized).

  In the present invention, the weight average molecular weight of the polycaprolactone segment in the resin containing the polycaprolactone segment is preferably 500 to 2,500, and more preferably 1,000 to 1,500. . When the weight average molecular weight of the polycaprolactone segment is 500 to 2,500, the self-repairing effect is more manifested, the scratch resistance is improved, and the repeated scratch resistance is further improved.

  Next, the polyalkylene glycol segment refers to a segment represented by Chemical Formula 5. The polyalkylene glycol includes those having an alkylene glycol repeating unit of 2 (dimer) and 3 (trimer) and an oligomer having an alkylene glycol repeating unit of up to 11.

  n is an integer of 2 to 4, and m is an integer of 2 to 11.

  The resin containing the polyalkylene glycol segment preferably has at least one hydroxyl group (hydroxyl group). The hydroxyl group is preferably at the end of the resin containing the polyalkylene glycol segment.

  The resin containing a polyalkylene glycol segment is preferably a polyalkylene glycol (meth) acrylate having an acrylate group at the terminal in order to impart elasticity. The number of acrylate functional groups (or methacrylate functional groups) of the polyalkylene glycol (meth) acrylate is not limited, but is most preferably monofunctional from the viewpoint of self-healing properties of the cured product.

  Examples of the polyalkylene glycol (meth) acrylate contained in the coating composition used for forming the surface layer include polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, and polybutylene glycol (meth) acrylate. . The structures are represented by the following chemical formula 6, chemical formula 7, and chemical formula 8, respectively.

  Polyethylene glycol (meth) acrylate:

  Polypropylene glycol (meth) acrylate:

  Polybutylene glycol (meth) acrylate:

In Chemical Formula 6, Chemical Formula 7, and Chemical Formula 8, R is hydrogen (H) or a methyl group (—CH ₃ ), and m is an integer from 2 to 11.

  In the present invention, the resin constituting the surface layer is preferably formed by reacting a compound containing an isocyanate group, which will be described later, with the hydroxyl group of (poly) alkylene glycol (meth) acrylate and using it as the urethane (meth) acrylate in the surface layer. However, (2) It can have a urethane bond and (3) (poly) alkylene glycol segment, and as a result, it can improve the toughness of the surface layer and improve self-repairability, which is preferable.

  Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl as the hydroxyalkyl (meth) acrylate compounded at the same time as the urethanization reaction between the compound containing an isocyanate group and the polyalkylene glycol (meth) acrylate Examples include (meth) acrylate.

  Next, the polycarbonate segment refers to a segment represented by Chemical Formula 9. Polycarbonate includes carbonate repeating units such as 2 (dimer) and 3 (trimer), and oligomers having up to 16 carbonate repeating units.

n is an integer of 2-16.
R ₄ represents an alkylene group or cycloalkylene group having 1 to 8 carbon atoms.

  The resin containing the polycarbonate segment preferably has at least one hydroxyl group (hydroxyl group). The hydroxyl group is preferably at the end of the resin containing the polycarbonate segment.

As the resin containing a polycarbonate segment, a polycarbonate diol having a bifunctional hydroxyl group is particularly preferable. Specifically, it is represented by Chemical Formula 10.
Polycarbonate diol:

  n is an integer of 2-16. R represents an alkylene group having 1 to 8 carbon atoms or a cycloalkylene group.

  The polycarbonate diol may have any number of repeating carbonate units, but if the number of repeating carbonate units is too large, the strength of the cured urethane (meth) acrylate will decrease, so the number of repeating units should be 10 or less. Is preferred. The polycarbonate diol may be a mixture of two or more types of polycarbonate diols having different repeating numbers of carbonate units.

  The polycarbonate diol preferably has a number average molecular weight of 500 to 10,000, more preferably 1,000 to 5,000. When the number average molecular weight is less than 500, suitable flexibility may be difficult to obtain, and when the number average molecular weight exceeds 10,000, the heat resistance and solvent resistance may be deteriorated. It is.

  Moreover, as polycarbonate diol used by this invention, UH-CARB, UD-CARB, UC-CARB (Ube Industries, Ltd.), PLACEL CD-PL, PLACEL CD-H (Daicel Chemical Industries, Ltd.), Kuraray polyol C Products such as the series (Kuraray Co., Ltd.) and the Duranol series (Asahi Kasei Chemicals Co., Ltd.) can be suitably exemplified. These polycarbonate diols can be used alone or in combination of two or more.

  Furthermore, in the present invention, the resin containing the polycaprolactone segment may contain (or copolymerize) other segments and monomers in addition to the polycaprolactone segment. For example, a polydimethylsiloxane segment, a polysiloxane segment, or a compound containing an isocyanate compound described later may be contained (or copolymerized).

  In the present invention, preferably, the resin constituting the surface layer is obtained by reacting a compound containing an isocyanate group, which will be described later, with a hydroxyl group of polycarbonate diol, as a urethane (meth) acrylate in the surface layer. It can have a urethane bond and (1) a polycarbonate diol segment. As a result, the toughness of the surface layer can be improved and the self-healing property can be improved, and the repeated scratch resistance can be improved.

[Compound containing urethane bond and isocyanate group]
In the present invention, the “urethane bond” refers to a bond represented by Chemical Formula 11.

  The resin constituting the surface layer has this bond, whereby the toughness of the entire surface layer can be improved.

  When the coating composition A contains a commercially available urethane-modified resin, the resin constituting the surface layer can have a urethane bond. Further, when the surface layer is formed, a urethane bond is generated by applying, drying and curing a coating composition A containing a compound containing an isocyanate group and a compound containing a hydroxyl group as a precursor, thereby forming a surface layer. It is also possible to contain a urethane bond.

  In this invention, it is preferable to introduce | transduce a urethane bond into resin which comprises a surface layer by making an isocyanate group and a hydroxyl group react, and producing | generating a urethane bond. By reacting an isocyanate group and a hydroxyl group to generate a urethane bond, the toughness of the surface layer is improved and the self-repairing property is improved, whereby the scratch resistance can be improved.

  In addition, if a resin containing the above-mentioned polycaprolactone segment, polycarbonate segment, polyalkylene glycol segment or a hydroxyl group is present, a urethane bond is formed between these resin and a compound containing an isocyanate group as a precursor by heat or the like. It is also possible to make it.

  When a surface layer is formed using a compound containing an isocyanate group and a resin containing a polysiloxane segment having a hydroxyl group, which will be described later, or a resin containing a polydimethylsiloxane segment having a hydroxyl group, the toughness of the surface layer and self-healing In addition to the properties, it is possible to improve the slip property of the surface, and it is more preferable from the viewpoint of repeated scratch resistance.

  In the present invention, the compound containing an isocyanate group refers to a resin containing an isocyanate group, and a monomer or oligomer containing an isocyanate group. Examples of the compound containing an isocyanate group include methylene bis-4-cyclohexyl isocyanate, trimethylolpropane adduct of tolylene diisocyanate, trimethylolpropane adduct of hexamethylene diisocyanate, trimethylolpropane adduct of isophorone diisocyanate, and tolylene diisocyanate. Examples include isocyanurate bodies, isocyanurate bodies of hexamethylene diisocyanate, (poly) isocyanates such as a burette body of hexamethylene isocyanate, and block bodies of the above isocyanates.

  Of these isocyanate group-containing compounds, aliphatic isocyanates are preferred because of their high self-healing properties compared to alicyclic and aromatic isocyanates. The compound containing an isocyanate group is more preferably hexamethylene diisocyanate. The isocyanate group-containing compound is particularly preferably an isocyanate having an isocyanurate ring from the viewpoint of heat resistance, and most preferably an isocyanurate of hexamethylene diisocyanate. Isocyanates having an isocyanurate ring form a surface layer having both self-healing properties and heat resistance.

[Fluorine compound segment, polysiloxane segment, polydimethylsiloxane segment]
In the laminated film of the present invention, the resin constituting the surface layer preferably has a segment containing at least one selected from the group consisting of a fluorine compound segment, a polysiloxane segment, and a polydimethylsiloxane segment.

  Further, a coating composition A containing a resin containing a segment containing at least one selected from the group consisting of a fluorine compound segment, a polysiloxane segment, and a polydimethylsiloxane segment, or a coating composition A containing a precursor is formed. By using it in one, the resin constituting the surface layer can have these.

  Hereinafter, these fluorine compound segment, polysiloxane segment, and polydimethylsiloxane segment will be described.

  First, the fluorine compound segment refers to a segment including at least one selected from the group consisting of a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group.

  Here, a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, and a fluorooxyalkanediyl group are alkyl groups, oxyalkyl groups, alkenyl groups, alkanediyl groups, and oxyalkanediyl groups. A part or all of the substituents are replaced by fluorine, both of which are mainly composed of fluorine atoms and carbon atoms, and there may be branching in the structure. A plurality of linked dimers, trimers, oligomers, and polymer structures may be formed.

  The fluorine compound segment is preferably a fluoropolyether segment, which is a site comprising a fluoroalkyl group, an oxyfluoroalkyl group, an oxyfluoroalkanediyl group or the like, more preferably represented by Chemical Formula 5 or Chemical Formula 6. As described above, it is a fluoropolyether segment.

  The fluoropolyether segment is a segment composed of a fluoroalkyl group, an oxyfluoroalkyl group, an oxyfluoroalkanediyl group, and the like, and has a structure represented by Chemical Formula 12 and Chemical Formula 13.

Here, n1 is an integer of 1 to 3, n2 to n5 are integers of 1 or 2, k, m, p, and s are integers of 0 or more, and p + s is 1 or more. Preferably, n1 is 2 or more, n2 to n5 are integers of 1 or 2, more preferably n1 is 3, n2 and n4 are 2, and n3 and n5 are integers of 1 or 2.
There is a preferred range for the chain length of the fluoropolyether segment, and the carbon number is preferably 4 or more and 12 or less, more preferably 4 or more and 10 or less, and particularly preferably 6 or more and 8 or less. When the number of carbon atoms is 3 or less, the surface energy is not sufficiently reduced, and thus the oil repellency may be lowered. When the number is 13 or more, the solubility in a solvent is lowered, and the quality of the surface layer may be lowered.

  When the resin contained in the surface layer contains a fluorine compound segment, the coating composition A described above preferably contains the following fluorine compound. This fluorine compound is a compound represented by Chemical Formula 14.

Here, R ^f1 represents a fluorine compound segment, R ₇ represents an alkanediyl group, an alkanetriyl group, and an ester structure, urethane structure, ether structure, and triazine structure derived therefrom, and D ¹ represents a reactive site.

  This reactive site refers to a site that reacts with other components by external energy such as heat or light. Examples of such reactive sites include alkoxysilyl groups and silanol groups in which alkoxysilyl groups are hydrolyzed from the viewpoint of reactivity, carboxyl groups, hydroxyl groups, epoxy groups, vinyl groups, allyl groups, acryloyl groups, methacryloyl groups, and the like. Can be mentioned. Of these, vinyl groups, allyl groups, alkoxysilyl groups, silyl ether groups, silanol groups, epoxy groups, and acryloyl (methacryloyl) groups are preferred from the viewpoints of reactivity and handling properties.

  An example of the fluorine compound is a compound shown below. 3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropyltriisopropoxysilane, 3,3,3-trifluoropropyltrichlorosilane, 3,3,3-trifluoropropyltriisocyanate silane, 2-perfluorooctyltrimethoxysilane, 2-perfluorooctylethyltriethoxysilane, 2-perfluorooctylethyltriisopropoxysilane, 2-perfluorooctylethyltri Chlorosilane, 2-perfluorooctyl isocyanate silane, 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2-perfluorobutylethyl acrylate, 3-perfluoro Butyl-2-hydroxypropyl acrylate, 2-perfluorohexylethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctylethyl acrylate, 3-perfluorooctyl-2-hydroxypropyl acrylate, 2- Perfluorodecylethyl acrylate, 2-perfluoro-3-methylbutylethyl acrylate, 3-perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate, 2-perfluoro-5-methylhexylethyl acrylate, 3-perfluoro -5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl acrylate, tetrafluoropropyl acrylate Octafluoropentyl acrylate, dodecafluoroheptyl acrylate, hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2-par Fluorobutylethyl methacrylate, 3-perfluorobutyl-2-hydroxypropyl methacrylate, 2-perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluoro- 3-methylbutylethyl methacrylate, 3-perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-perfluoro-5-methyl Hexylethyl methacrylate, 3-perfluoro-5-methylhexyl-2-hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-6-methyloctyl methacrylate, tetrafluoropropyl methacrylate, octafluoro Examples include pentyl methacrylate, octafluoropentyl methacrylate, dodecafluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyltrifluoroethyl methacrylate, hexafluorobutyl methacrylate, triacryloyl-heptadecafluorononenyl-pentaerythritol.

The fluorine compound may have a plurality of fluoropolyether moieties per molecule.
Examples of commercially available fluorine compounds include RS-75 (DIC Corporation), Optool DAC-HP (Daikin Industries Co., Ltd.), C10GACRY, C8HGOL (Oil Products Co., Ltd.), and the like. The product can be used.

  Next, the polysiloxane segment will be described. In the present invention, the polysiloxane segment refers to a segment represented by the following chemical formula 15.

  Here, the polysiloxane includes both those having a low molecular weight (so-called oligomer) having about 100 repeating units of siloxane and those having a high molecular weight (so-called polymer) having more than 100 repeating units of siloxane.

R ₁ and R ₂ are either a hydroxyl group or an alkyl group having 1 to 8 carbon atoms, each having at least one or more in the formula, and n is an integer of 100 to 300.

  The details of the polysiloxane segment and polydimethylsiloxane segment will be described later, but the resin constituting the surface layer has these segments to improve heat resistance and weather resistance, and scratch resistance due to the lubricity of the surface layer. Can be improved. More preferably, it contains a polydimethylsiloxane segment represented by the following chemical formula 16 from the viewpoint of lubricity.

  In the present invention, a partially hydrolyzed product of a silane compound containing a hydrolyzable silyl group, an organosilica sol or a coating composition obtained by adding a hydrolyzable silane compound having a radical polymer to the organosilica sol, a polysiloxane segment It can be used as a resin to contain.

  Resins containing polysiloxane segments are tetraalkoxysilane, methyltrialkoxysilane, dimethyldialkoxysilane, γ-glycidoxypropyltrialkoxysilane, γ-glycidoxypropylalkyldialkoxysilane, γ-methacryloxypropyltrimethyl. A hydrolyzable silyl group on the surface of an organosilica sol dispersed in a complete or partial hydrolyzate of a silane compound having a hydrolyzable silyl group such as alkoxysilane or γ-methacryloxypropylalkyldialkoxysilane or an organic solvent. The thing etc. which added the hydrolysis silane compound of this can be illustrated.

  In the present invention, the resin containing a polysiloxane segment may contain (copolymerize) other segments in addition to the polysiloxane segment. For example, a monomer component having a polycaprolactone segment and a polydimethylsiloxane segment may be contained (copolymerized).

  When the resin containing a polysiloxane segment is a copolymer having a hydroxyl group, the surface using a coating composition containing a resin (copolymer) containing a polysiloxane segment having a hydroxyl group and a compound containing an isocyanate group When the layer is formed, the surface layer having a polysiloxane segment and a urethane bond can be efficiently formed.

  Next, the polydimethylsiloxane segment will be described. In the present invention, the polydimethylsiloxane segment refers to a segment represented by Chemical Formula 16. Polydimethylsiloxane includes both those having a low molecular weight (so-called oligomer) having 10 to 100 repeating units of dimethylsiloxane and those having a high molecular weight having more than 100 repeating units of dimethylsiloxane (so-called polymer).

  m is an integer of 10 to 300.

  If the resin constituting the surface layer has a polydimethylsiloxane segment, the polydimethylsiloxane segment is coordinated to the surface of the surface layer. By coordinating the polydimethylsiloxane segment to the surface of the surface layer, the lubricity of the surface layer surface can be improved and the frictional resistance can be reduced. As a result, the scratch resistance can be improved.

  In the present invention, as the resin containing a polydimethylsiloxane segment, it is preferable to use a copolymer obtained by copolymerizing a vinyl monomer with a polydimethylsiloxane segment.

  For the purpose of improving the toughness of the surface layer, the resin containing polydimethylsiloxane segments is preferably copolymerized with a monomer having a hydroxyl group that reacts with an isocyanate group.

  When the resin containing a polydimethylsiloxane segment is a copolymer having a hydroxyl group, a coating composition containing a resin (copolymer) containing a polydimethylsiloxane segment having a hydroxyl group and a compound containing an isocyanate group is used. When the surface layer is formed, the surface layer having a polydimethylsiloxane segment and a urethane bond can be efficiently formed.

  When the resin containing the polydimethylsiloxane segment is a copolymer with a vinyl monomer, any of a block copolymer, a graft copolymer, and a random copolymer may be used. When the resin containing the polydimethylsiloxane segment is a copolymer with a vinyl monomer, this is referred to as a polydimethylsiloxane copolymer. Polydimethylsiloxane copolymer can be produced by living polymerization method, polymer initiator method, polymer chain transfer method, etc., but considering the productivity, polymer initiator method, polymer chain transfer method can be used. It is preferable to use it.

  When the polymer initiator method is used, it can be copolymerized with another vinyl monomer using a polymer azo radical polymerization initiator represented by Chemical Formula 17. In addition, a two-stage polymerization is carried out by synthesizing a prepolymer in which a peroxide group is introduced into the side chain by copolymerizing a peroxy monomer and polydimethylsiloxane having an unsaturated group at a low temperature, and then copolymerizing the prepolymer with a vinyl monomer. Can also be done.

  m is an integer of 10 to 300, and n is an integer of 1 to 50.

When the polymer chain transfer method is used, for example, HS-CH ₂ COOH or HS-CH ₂ CH ₂ COOH is added to the silicone oil represented by Chemical Formula 18 to form a compound having an SH group, and then the SH group A block copolymer can be synthesized by copolymerizing the silicone compound and vinyl monomer using chain transfer.

  m is an integer of 10 to 300.

  In order to synthesize a polydimethylsiloxane graft copolymer, for example, a graft copolymer can be easily obtained by copolymerizing a compound represented by Chemical Formula 19, that is, a methacrylic ester of polydimethylsiloxane and a vinyl monomer. it can.

  m is an integer of 10 to 300.

  Examples of vinyl monomers used in the copolymer with polydimethylsiloxane include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, n -Butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, styrene, α-methyl styrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride , Vinyl fluoride, vinylidene fluoride, glycidyl acrylate Glycidyl methacrylate, allyl glycidyl ether, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, acrylamide, methacrylamide, N-methylolacrylamide, N, N-dimethylacrylamide, N, N-dimethylaminoethyl Examples thereof include methacrylate, N, N-diethylaminoethyl methacrylate, diaceton acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and allyl alcohol.

  Polydimethylsiloxane copolymers include aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, ethanol, isopropyl alcohol, etc. It is preferable that the alcoholic solvent is produced by a solution polymerization method alone or in a mixed solvent.

  If necessary, a polymerization initiator such as benzoyl peroxide or azobisisobutylnitrile is used in combination. The polymerization reaction is preferably performed at 50 to 150 ° C. for 3 to 12 hours.

  The amount of the polydimethylsiloxane segment in the polydimethylsiloxane copolymer in the present invention is 1 to 100 mass% of all components of the polydimethylsiloxane copolymer in terms of lubricity and contamination resistance of the surface layer. It is preferably 30% by mass. The weight average molecular weight of the polydimethylsiloxane segment is preferably 1,000 to 30,000.

  In the present invention, when a resin containing a polydimethylsiloxane segment is used as the coating composition used for forming the surface layer, other segments are contained (copolymerized) in addition to the polydimethylsiloxane segment. May be. For example, a polycaprolactone segment or a polysiloxane segment may be contained (copolymerized).

  The coating composition used to form the surface layer includes a copolymer of a polycaprolactone segment and a polydimethylsiloxane segment, a copolymer of a polycaprolactone segment and a polysiloxane segment, a polycaprolactone segment, a polydimethylsiloxane segment, and a polymer. A copolymer with a siloxane segment can be used. The surface layer obtained using such a coating composition can have a polycaprolactone segment and a polydimethylsiloxane segment and / or a polysiloxane segment.

  The reaction of polydimethylsiloxane copolymer, polycaprolactone, and polysiloxane in a coating composition used to form a surface layer having a polycaprolactone segment, a polysiloxane segment, and a polydimethylsiloxane segment is a polydimethylsiloxane When synthesizing the copolymer, a polycaprolactone segment and a polysiloxane segment can be appropriately added and copolymerized.

[solvent]
The coating composition may contain a solvent. The number of solvent types is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less, still more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 4 or less.

  Here, the “solvent” refers to a substance that is liquid at room temperature and normal pressure, which can be evaporated in substantially the entire amount in the drying step after application.

  Here, the kind of solvent is determined by the molecular structure constituting the solvent. That is, the same elemental composition and the same type and number of functional groups have different bond relationships (structural isomers), which are not structural isomers, but what conformations are in three-dimensional space Those that do not overlap exactly even if they are removed (stereoisomers) are treated as different types of solvents. For example, 2-propanol and n-propanol are handled as different solvents.

  Furthermore, when it contains a solvent, it is preferable that it is a solvent which shows the following characteristics.

  Condition 1 When the solvent having the lowest relative evaporation rate (ASTM D3539-87 (2004)) based on n-butyl acetate is used as the solvent B, the relative evaporation rate of the solvent B is 0.4 or less.

  Here, the relative evaporation rate based on the solvent n-butyl acetate is an evaporation rate measured according to ASTM D3539-87 (2004). Specifically, it is a value defined as a relative value of the evaporation rate based on the time required for 90% by mass of n-butyl acetate to evaporate under dry air.

  When the relative evaporation rate of the solvent is larger than 0.4, the time required for the alignment of the polysiloxane segment and / or the polydimethylsiloxane segment and the fluorine compound segment to the outermost surface in the surface layer is shortened. Therefore, the self-restoring property and antifouling property of the obtained laminated film may be reduced. The lower limit of the relative evaporation rate of the solvent is not a problem as long as it is a solvent that can be evaporated and removed from the coating film in the drying process, and may be 0.005 or more in a general coating process.

  Solvents include isobutyl ketone (relative evaporation rate: 0.2), isophorone (relative evaporation rate: 0.026), diethylene glycol monobutyl ether (relative evaporation rate: 0.004), diacetone alcohol (relative evaporation rate: 0). .15), oleyl alcohol (relative evaporation rate: 0.003), ethylene glycol monoethyl ether acetate (relative evaporation rate: 0.2), nonylphenoxyethanol (relative evaporation rate: 0.25), propylene glycol monoethyl ether ( Relative evaporation rate: 0.1) and cyclohexanone (relative evaporation rate: 0.32).

[Other components in the coating composition]
Moreover, it is preferable that the said coating composition A contains a polymerization initiator, a hardening | curing agent, and a catalyst. A polymerization initiator and a catalyst are used to accelerate the curing of the surface layer. As the polymerization initiator, those capable of initiating or accelerating polymerization, condensation or crosslinking reaction by anion, cation, radical polymerization reaction or the like of components contained in the coating composition are preferable.

  Various polymerization initiators, curing agents and catalysts can be used. In addition, the polymerization initiator, the curing agent, and the catalyst may be used alone, or a plurality of polymerization initiators, curing agents, and catalysts may be used simultaneously. Furthermore, an acidic catalyst or a thermal polymerization initiator may be used in combination. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, acetic acid and the like. Examples of the thermal polymerization initiator include peroxides and azo compounds. Examples of the photopolymerization initiator include alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, amine compounds, and the like. Examples of the crosslinking catalyst that promotes the urethane bond formation reaction include dibutyltin dilaurate and dibutyltin diethylhexoate.

  In addition, the coating composition may include other crosslinking agents such as melamine crosslinking agents such as alkoxymethylol melamine, acid anhydride crosslinking agents such as 3-methyl-hexahydrophthalic anhydride, and amine crosslinking agents such as diethylaminopropylamine. It can also be included.

  As the photopolymerization initiator, an alkylphenone compound is preferable from the viewpoint of curability. Specific examples of the alkylphenone type compound include 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- (4-methylthiophenyl)- 2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-phenyl) -1-butane, 2- (dimethylamino) -2-[(4-methylphenyl) methyl]- 1- (4-phenyl) -1-butane, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butane, 2- (dimethylamino) -2-[(4-methylphenyl) ) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butane, 1-cyclohexyl-phenylketone, 2-methyl-1-phenylpropane-1-o , 1- [4- (2-Ethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, bis (2-phenyl-2-oxoacetic acid) oxybisethylene, and materials thereof And the like having a high molecular weight.

  In addition, a leveling agent, an ultraviolet absorber, a lubricant, an antistatic agent, and the like may be added to the coating composition used for forming the surface layer as long as the effects of the present invention are not impaired. Thereby, the surface layer can contain a leveling agent, an ultraviolet absorber, a lubricant, an antistatic agent, and the like. Examples of the leveling agent include acrylic copolymers, silicone-based and fluorine-based leveling agents. Specific examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, oxalic acid anilide-based, triazine-based and hindered amine-based ultraviolet absorbers. Examples of the antistatic agent include metal salts such as lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, magnesium salt and calcium salt.

[Production method of laminated film]
The surface layer formed on the surface of the laminated film of the present invention is preferably formed by applying the above-mentioned surface layer coating composition on the above-mentioned supporting substrate, drying and curing. Hereinafter, the process of applying the coating composition is described as an application process, the process of drying is described as a drying process, and the process of curing is described as a curing process. As the surface layer coating composition, two or more types of coating compositions may be applied sequentially or simultaneously to form a surface layer composed of two or more layers.

  Here, “sequentially apply” means that one type of coating composition is applied onto a supporting substrate, dried and cured, and then another coating composition is applied thereon and dried. It means that a surface layer composed of two or more layers is formed by curing. By appropriately selecting the type of coating composition to be used, it is possible to control the magnitude and gradient of the contact stiffness between the surface layer side and the support substrate side of the surface layer, and the contact stiffness between the support substrate and the surface layer. . Furthermore, the form of the contact rigidity distribution in the surface layer can be controlled stepwise or continuously by appropriately selecting the type, composition, drying conditions and curing conditions of the coating composition.

  Further, “apply simultaneously” means that two or more kinds of coating compositions are simultaneously applied on a supporting substrate, followed by drying and curing in the application step.

  In the coating process, the method of coating the coating composition is not particularly limited, but the coating composition is dip coating, roller coating, wire bar coating, gravure coating, die coating (US Pat. No. 2,681,294), etc. It is preferable to apply to the support substrate. Further, among these coating methods, the gravure coating method or the die coating method is more preferable as the coating method.

  In the case where two or more kinds of coating compositions are simultaneously applied, a method such as multilayer slide die coating, multilayer slot die coating, and wet-on-wet coating can be used, although not particularly limited.

  An example of a multilayer slide die coat is shown in FIG. In the multilayer slide die coating, a liquid film composed of two or more kinds of coating compositions is sequentially laminated using the multilayer slide die 17 and then applied onto a supporting substrate.

  An example of a multilayer slot die coat is shown in FIG. In the multilayer slot die coating, a liquid film composed of two or more kinds of coating compositions is laminated on a supporting substrate simultaneously with application using a multilayer slot die 18.

  An example of a wet-on-wet coat is shown in FIG. In the wet-on-wet coat, after forming a one-layer liquid film made of the coating composition discharged from the single-layer slot die 19 on the support substrate, the liquid film is in an undried state, A liquid film made of another coating composition discharged from the single-layer slot die 19 is laminated.

  Following the coating step, the liquid film coated on the support substrate is dried by a drying step. From the viewpoint of completely removing the solvent from the obtained laminated film, the drying step is preferably accompanied by heating of the liquid film.

  Examples of the heating method in the drying step include heat transfer drying (adhesion to a high-temperature object), convection heat transfer (hot air), radiant heat transfer (infrared rays), and others (microwave, induction heating). Among these, a method using convective heat transfer or radiant heat transfer is preferable because it is necessary to make the drying speed uniform in the width direction.

The drying process of the liquid film in the drying process is generally divided into (A) constant rate drying period and (B) reduced rate drying period. In the former, since the diffusion of solvent molecules into the atmosphere at the surface of the liquid film is the rate-limiting rate of drying, the drying rate is constant in this section, and the drying rate is the partial pressure of the solvent to be evaporated, wind speed, and temperature in the atmosphere. The film surface temperature is constant at a value determined by the hot air temperature and the partial pressure of the solvent to be evaporated in the atmosphere. In the latter, since the diffusion of the solvent in the liquid film is rate-limiting, the drying rate does not show a constant value in this section and continues to decrease, and is governed by the diffusion coefficient of the solvent in the liquid film, and the film surface temperature gradually increases. To rise. Here, the drying rate represents the amount of solvent evaporation per unit time and unit area, and has a dimension of g · m ⁻² · s ⁻¹ .

The drying speed is preferably 0.1 g · m ⁻² · s ⁻¹ or more and 10 g · m ⁻² · s ⁻¹ or less, and 0.1 g · m ⁻² · s ⁻¹ or more and 5 g · m ⁻² ·. More preferably, it is s ⁻¹ or less. By setting the drying speed in the constant rate drying section within this range, unevenness due to nonuniform drying speed can be prevented.

  The temperature is preferably 15 ° C. to 129 ° C., more preferably 50 ° C. to 129 ° C., and more preferably 50 ° C. It is particularly preferable that the temperature is from 99 to 99 ° C.

  In the reduced-rate drying period, the aforementioned polysiloxane segment and / or polydimethylsiloxane segment and fluorine compound segment are aligned with the evaporation of the residual solvent. In this process, since time for alignment is required, the film surface temperature increase rate during the decreasing drying period is preferably 5 ° C./second or less, and more preferably 1 ° C./second or less.

  Subsequent to the drying step, a further curing operation (curing step) may be performed by irradiation with heat or active energy rays.

As the active energy rays, electron beams (EB rays) and / or ultraviolet rays (UV rays) are preferable from the viewpoint of versatility. In the case of curing with ultraviolet rays, oxygen concentration is preferably as low as possible because oxygen inhibition can be prevented, and curing in a nitrogen atmosphere (nitrogen purge) is more preferable. When the oxygen concentration is high, the hardening of the outermost surface is inhibited, the hardening of the surface becomes weak, and the self-repairing property and the scratch resistance may be lowered. Examples of the ultraviolet lamp used when irradiating ultraviolet rays include a discharge lamp method, a flash method, a laser method, and an electrodeless lamp method. When using a high-pressure mercury lamp is a discharge lamp type, illuminance of ultraviolet rays is preferably 100~3,000mW / cm ^2, more preferably 200~2,000mW / cm ^2, more preferably the 300~1,500mW / cm ² It is preferable to perform ultraviolet irradiation under the following conditions. Integrated quantity of ultraviolet light is preferably 100~3,000mJ / cm ^2, more preferably 200~2,000mJ / cm ^2, is further preferably irradiated with ultraviolet rays under the condition that the 300~1,500mJ / cm ² preferable. Here, the illuminance of ultraviolet rays is the irradiation intensity received per unit area, and changes depending on the lamp output, the emission spectral efficiency, the diameter of the light emitting bulb, the design of the reflector, and the light source distance to the irradiated object. However, the illuminance does not change depending on the conveyance speed. Further, the UV integrated light amount is irradiation energy received per unit area, and is the total amount of photons reaching the surface. The integrated light quantity is inversely proportional to the irradiation speed passing under the light source, and is proportional to the number of irradiations and the number of lamps.

[Application example]
The laminated film of the present invention is required to have particularly high scratch resistance and repeated scratch resistance in applications in which optical quality is important, taking advantage of excellent optical properties, scratch resistance, repeated scratch resistance, and being a thin film. It can be suitably used for applications in which scratches and cracks are less conspicuous.

  For example, glasses / sunglasses, cosmetic boxes, plastic molded products such as food containers, water tanks, showcases for exhibitions, smartphone housings, touch panels, color filters, flat panel displays, keyboards, TV / air conditioner remote controls It can be suitably used for the surface and inside of each of home appliances such as, mirrors, window glass, buildings, dashboards, car navigation / touch panels, vehicle parts such as room mirrors and windows, and various printed materials.

  Next, although this invention is demonstrated based on an Example, this invention is not necessarily limited to these.

[Urethane (meth) acrylate A]
[Synthesis of Urethane (Meth) acrylate A1]
50 parts by mass of toluene, isocyanurate-modified type of hexamethylene diisocyanate (“Takenate” (registered trademark) D-170N manufactured by Mitsui Chemicals), polycaprolactone-modified hydroxyethyl acrylate (Placcel FA5 manufactured by Daicel Chemical Industries, Ltd.) 76 parts by mass, 0.02 parts by mass of dibutyltin laurate and 0.02 parts by mass of hydroquinone monomethyl ether were mixed and held at 70 ° C. for 5 hours. Thereafter, 79 parts by mass of toluene was added to obtain a toluene solution of urethane (meth) acrylate A1 having a solid content concentration of 50% by mass.

[Urethane (meth) acrylate B]
[Synthesis of urethane (meth) acrylate B1]
100 parts by mass of toluene, 50 parts by mass of methyl-2,6-diisocyanatohexanoate (LDI manufactured by Kyowa Hakko Kirin Co., Ltd.) and 119 parts by mass of polycarbonate diol (“Placcel” (registered trademark) CD-210HL manufactured by Daicel Chemical Industries, Ltd.) The parts were mixed, heated to 40 ° C. and held for 8 hours. Then, 28 parts by mass of 2-hydroxyethyl acrylate (Kyoeisha Chemical Co., Ltd., light ester HOA), 5 parts by mass of dipentaerythritol hexaacrylate (M-400, manufactured by Toagosei Co., Ltd.) and 0.02 parts by mass of hydroquinone monomethyl ether were added. The mixture was held at 70 ° C. for 30 minutes, 0.02 part by weight of dibutyltin laurate was added, and the mixture was held at 80 ° C. for 6 hours. Finally, 97 parts by mass of toluene was added to obtain a toluene solution of urethane (meth) acrylate B1 having a solid content concentration of 50% by mass.

[Urethane (meth) acrylate C]
[Synthesis of urethane (meth) acrylate C1]
Isocyanurate modified form of hexamethylene diisocyanate (“Takenate” (registered trademark) D-170N, manufactured by Mitsui Chemicals, Inc., isocyanate group content: 20.9% by mass), 50 parts by mass, polyethylene glycol monoacrylate (manufactured by NOF Corporation) "Blemmer" (registered trademark) AE-150, hydroxyl value: 264 (mgKOH / g)) 53 parts by mass, dibutyltin laurate 0.02 parts by mass and hydroquinone monomethyl ether 0.02 parts by mass were charged. And it reacted by hold | maintaining at 70 degreeC for 5 hours. After completion of the reaction, 102 parts by mass of methyl ethyl ketone (hereinafter sometimes referred to as MEK) was added to the reaction solution to obtain urethane (meth) acrylate C1 having a solid content concentration of 50% by mass.

[Acrylate compound]
[Acrylate 1]
As the acrylate compound 1, “EBECRYL” (registered trademark) 600 (a solid content concentration of 100 mass% manufactured by Daicel Ornex Co., Ltd.) was used.

[Polyfunctional acrylate compound]
[Multifunctional acrylate 1]
As the polyfunctional acrylate 1, dipentaerythritol hexaacrylate (“KAYARAD” DPHA manufactured by Nippon Kayaku Co., Ltd., solid content concentration: 100 mass%) was used.

[Fluorine compounds]
[Fluorine compound 1]
As the fluorine compound 1, an acrylate compound containing a fluoropolyether segment (“Megafac” (registered trademark) RS-75 manufactured by DIC Corporation, solid content concentration: 40 mass%, solvent (toluene and methyl ethyl ketone), 60 mass%)) was used.

[Photo radical polymerization initiator]
[Photoradical polymerization initiator 1]
As the photo radical polymerization initiator 1, “Irgacure” (registered trademark) 184 (manufactured by BASF Japan Ltd., solid content concentration: 100% by mass) was used.

[Preparation of coating composition A]
[Coating composition A1]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A1 having a solid concentration of 30% by mass.
-50 parts by mass of urethane (meth) acrylate A1 solution (solid content concentration 50% by mass)-50 parts by mass of urethane (meth) acrylate C1 solution (solid content concentration 50% by mass)-Fluorine compound 1 solution (solid content concentration 40% by mass) ) 3.8 parts by mass · radical photopolymerization initiator 1 1.5 parts by mass · ethylene glycol monobutyl ether 10 parts by mass.

[Coating composition A2]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A2 having a solid content concentration of 30% by mass.
・ Urethane (meth) acrylate A1 solution (solid content concentration: 50 mass%) 75 mass parts ・ Urethane (meth) acrylate C1 solution (solid content concentration: 50 mass%) 25 mass parts ・ Fluorine compound 1 solution (solid content concentration: 40 mass%) ) 3.8 parts by mass · radical photopolymerization initiator 1 1.5 parts by mass · ethylene glycol monobutyl ether 10 parts by mass.

[Coating composition A3]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A3 having a solid concentration of 30% by mass.
-50 parts by mass of urethane (meth) acrylate A1 solution (solid content concentration 50% by mass)-50 parts by mass of urethane (meth) acrylate B1 solution (solid content concentration 50% by mass)-Fluorine compound 1 solution (solid content concentration 40% by mass) ) 3.8 parts by mass · radical photopolymerization initiator 1 1.5 parts by mass · ethylene glycol monobutyl ether 10 parts by mass.

[Coating composition A4]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A4 having a solid content of 30% by mass.
-50 parts by mass of urethane (meth) acrylate B1 solution (solid content concentration 50% by mass)-50 parts by mass of urethane (meth) acrylate C1 solution (solid content concentration 50% by mass)-Fluorine compound 1 solution (solid content concentration 40% by mass) ) 3.8 parts by mass · radical photopolymerization initiator 1 1.5 parts by mass · ethylene glycol monobutyl ether 10 parts by mass.

[Coating composition A5]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A5 having a solid content concentration of 30% by mass.
・ Urethane (meth) acrylate A1 solution (solid content concentration: 50 mass%) 90 mass parts ・ Acrylate compound 1 5 mass parts ・ Fluorine compound 1 solution (solid content concentration 40 mass%) 3.8 mass parts ・ Photoradical polymerization initiator 1 1.5 parts by mass / ethylene glycol monobutyl ether 10 parts by mass.

[Coating composition A6]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition A6 having a solid content concentration of 30% by mass.
・ Urethane (meth) acrylate C1 solution (solid content concentration 50 mass%) 80 mass parts ・ Acrylate compound 2 50 mass parts ・ Fluorine compound 1 solution (solid content concentration 40 mass%) 3.8 mass parts ・ Radical radical polymerization initiator 1 1.5 parts by mass / ethylene glycol monobutyl ether 10 parts by mass.

[Preparation of coating composition B]
[Coating composition B1]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition B1 having a solid concentration of 40% by mass.
-Multifunctional acrylate 1 50 mass parts-Photoradical polymerization initiator 1 1.5 mass parts.

[Coating composition B2]
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition B2 having a solid content concentration of 30% by mass.
-Urethane (meth) acrylate A1 solution (solid content concentration 50 mass%) 60 mass parts-Acrylate compound 1 20 mass parts-Photoradical polymerization initiator 1 1.5 mass parts.

[polyester]
[Polyester 1]
Polyester 1 was a polyethylene terephthalate resin (intrinsic viscosity 0.65) in which the terephthalic acid (TPA) component was 100 mol% as the dicarboxylic acid component and the ethylene glycol (EG) component was 100 mol% as the glycol component.

[Polyester 2]
As polyester 2, copolymer polyester (GN001 manufactured by Eastman Chemical Co.) in which 1,4-cyclohexanedimethanol (CHDM) was copolymerized with 20 mol% with respect to the glycol component was used, and 1,4-cyclohexanedimethanol copolymerized polyethylene terephthalate. Used (intrinsic viscosity 0.75).

[Polyester 3]
Polyester 3 is an isophthalic acid copolymerized polyethylene terephthalate resin containing 82.5 mol% of terephthalic acid component as dicarboxylic acid component, 17.5 mol% of isophthalic acid (IPA) component, and 100 mol% of ethylene glycol component as glycol component. (Intrinsic viscosity 0.7) was used.

[Particle Master]
As the particle master, a polyethylene terephthalate particle master (intrinsic viscosity 0.65) containing polyester 1 with agglomerated silica particles having a number average particle size of 2.2 μm at a particle concentration of 2 mass% was used.

[Supporting substrate]
[Support base material A1]
The composition is as shown in the table, and the raw materials are supplied to separate bent co-directional twin-screw extruders each having an oxygen concentration of 0.2% by volume, the A layer extruder cylinder temperature is 280 ° C., and the B layer extruder cylinder temperature is Are melted at 270 ° C. and merged into a three-layer structure of A layer / B layer / A layer in the feed block. After joining, the short tube temperature is 275 ° C. and the die temperature is 280 ° C. The sheet was discharged in a sheet form on a cooling drum whose temperature was controlled to ° C. At that time, a wire electrode having a diameter of 0.1 mm was applied electrostatically and adhered to the cooling drum to obtain an unstretched sheet. Next, preheating was performed for 1.5 seconds at a preheating temperature of 85 ° C. in the longitudinal direction, the film was stretched 3.3 times in the longitudinal direction at a stretching temperature of 115 ° C., and immediately cooled with a metal roll whose temperature was controlled at 40 ° C. Next, pre-heating is performed for 1.5 seconds at a preheating temperature of 85 ° C. with a tenter-type horizontal stretching machine, and the film is stretched 3.3 times in the width direction at a stretching first half temperature of 115 ° C., a stretching middle temperature of 135 ° C., and a stretching second half temperature of 145 ° C. In the tenter, heat treatment was performed at a heat treatment temperature of 230 ° C. while relaxing by 5% in the width direction to obtain a biaxially oriented polyester film having a film thickness of 40 μm. This was designated as a supporting substrate A1.

[Support base material A2]
A biaxially oriented polyester film having a thickness of 40 μm was obtained in the same manner as in the supporting substrate A1, except that the composition was changed as shown in the table. This was designated as a supporting substrate A2.

[Support base material A3]
A biaxially oriented polyester film having a thickness of 25 μm was obtained in the same manner as in the supporting substrate A1, except that the composition was changed as shown in the table. This was designated as a supporting substrate A3.

[Support base material B1]
“Lumirror” (registered trademark) U48 (thickness 50 μm, manufactured by Toray Industries, Inc.) was used as the support base B1.

[Support base material B2]
“Lumirror” (registered trademark) U48 (thickness 125 μm, manufactured by Toray Industries, Inc.) was used as the supporting base material B2.

[Production method of laminated film]
[Production of laminated film]
The coating composition A and coating composition B are continuously applied to the support substrate using a slot die coater, and the discharge flow rate from the slot is adjusted so that the thickness of the surface layer after drying becomes a specified film thickness. And applied. The conditions of the drying wind that hits the liquid film from application to drying and curing are as follows.

[Drying process]
Ventilation temperature and humidity: Temperature: 80 ° C., Relative humidity: 1% or less Wind speed: Application surface side: 5 m / sec, Anti-application surface side: 5 m / sec Air direction: Application surface side: Parallel to the substrate surface, anti-application Surface side: perpendicular to the surface of the substrate Residence time: 2 minutes [curing step]
Irradiation output: 400 W / cm ²
Integrated light quantity: 120 mJ / cm ²
Oxygen concentration: 0.1% by volume.

  The laminated film of Examples 1-9 and Comparative Examples 1-4 was created with the above method. The production methods of the laminated film corresponding to each example and comparative example, and the film thickness of each layer are shown in Tables 2 and 3 described later.

[Evaluation of polyester resin]
The polyester resin used for the supporting substrate was subjected to the following performance evaluation, and the results obtained are shown in Table 1. Unless otherwise specified, the measurement was performed three times for each sample, and the average value was used.

[Polyester composition]
The polyester resin and film can be dissolved in hexafluoroisopropanol (HFIP), and the content of each monomer residue component and by-product diethylene glycol can be quantified using ¹ H-NMR and ¹³ C-NMR. In the case of a laminated film, the components constituting each layer can be collected and evaluated by scraping off each layer of the film according to the laminated thickness. In addition, about each laminated film of the Example and comparative example of this invention, the composition was computed by calculation from the mixing ratio at the time of film manufacture.

[Melting point of polyester]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., RDC220), measurement and analysis were performed in accordance with JIS K7121-1987 and JIS K7122-1987. Using 5 mg of a polyester film as a sample, the temperature at the apex of the endothermic peak obtained from the DSC curve when the temperature was raised from 25 ° C. to 300 ° C. at 20 ° C./min was defined as the melting point. In the case of a laminated film, the melting point of each layer alone can be measured by scraping each layer of the film according to the laminated thickness.

  Table 1 summarizes the evaluation results of the polyester resin used for the support substrate obtained.

[Evaluation of support substrate and laminated film]
About the support base material and the produced laminated film, the following performance evaluation was implemented and the obtained result is shown to Table 2, 3. Unless otherwise specified, the measurement was performed three times by changing the location of one sample in each example and comparative example, and the average value was used.

[Support substrate, surface layer thickness]
The thickness of the support base material and the surface layer on the support base material was measured by observing a cross section using an electron microscope (SEM). The thickness of each layer was measured according to the following method. The thickness of each layer was read by software (image processing software ImageJ) from an image obtained by photographing a cross section of the laminated film at a magnification of 3,000 with an SEM. The average value obtained by measuring the layer thickness of 30 points in total was taken as the measured value.

[Measurement of contact stiffness and indentation modulus]
For measurement, a nanoindenter “ENT-2100” manufactured by Elionix Co., Ltd. was used. One drop of “Aron Alpha” (registered trademark) professional impact resistance manufactured by Toagosei Co., Ltd. is applied to the support substrate side of the laminated film, and the laminated film is fixed to a dedicated sample fixing base via an instantaneous adhesive. Then, the measurement was performed using the surface layer side as the measurement surface. Moreover, when measuring a support base material, 1 drop of the said instantaneous adhesive agents was apply | coated to the one side of a support base material, and the measurement was performed similarly to the laminated | multilayer film. For the measurement, a triangular pyramid diamond indenter (Berkovich indenter) having a ridge angle of 115 ° was used. The measurement data is processed by dedicated analysis software (version 6.18) of “ENT-2100”, and the contact rigidity S _b (N / mm) of the support base material, the contact rigidity S _s (N / mm) of the surface layer, the surface The indentation elastic modulus E _IT (MPa) of the layer was measured.
Measurement mode: Load-unloading test Maximum load: 100 mN
Holding time when the maximum load is reached: 1 second load speed, unload speed: 10 mN / sec.

  For the evaluation of the supporting substrate, the surface layer is scraped off according to the laminated thickness, or the supporting substrate layer is exposed by peeling the surface layer, or the back surface of the supporting substrate not forming the surface layer is measured. It becomes possible to evaluate the supporting substrate by a method such as. As an example of the method of peeling the surface layer, in addition to the method of peeling without pretreatment, the laminated film is immersed in ethanol and left at 25 ° C. for 10 minutes, and then the surface layer of the laminated film is supported on the supporting substrate. The method of peeling from is mentioned.

  In addition, about the evaluation of the support base material of the Example and comparative example of this invention, it evaluated in the state before forming a surface layer.

[Retardation]
Using a phase difference measuring device (KOBRA-21ADH) manufactured by Oji Scientific Instruments Co., Ltd., installed in the device so that the film width direction is an angle defined by this measuring device, the incident angle is 0 ° (film Retardation at a wavelength of 590 nm in a direction perpendicular to the surface was measured. In addition, the test sample extract | collected and used the test piece cut out to the magnitude | size of laminated | multilayer film 35 mm x 35 mm.

[Self-healing property of surface layer]
After leaving at a temperature of 20 ° C. for 12 hours, in the same environment, the surface layer surface was subjected to the following load on a brass brush (manufactured by TRUSCO) and horizontally scratched five times, and then the wound was recovered after being left for 5 minutes. Was visually determined according to the following criteria.
10 points: No damage remains at a load of 9.8 N (1 kg weight) 7 points: No damage remains at a load of 9.8 N (1 kg weight), but no damage remains at 6.9 N (700 g weight) 4 points: Load 6 Scratches remain at 9.9N (700g weight), but no scratches remain at 4.9N (500g weight): Scratches remain at a load of 4.9N (500g weight).

[Repeated scratch resistance of laminated film]
After leaving at a temperature of 23 ° C. for 12 hours, after applying a load of 4.9 N (500 g weight) to a brass brush (manufactured by TRUSCO) on the surface layer surface in the same environment, scratching horizontally 20 times, Left for 5 minutes. Next, the following weight was placed on a brass brush (manufactured by TRUSCO), and the state of the surface when dropped 5 times from a height of 10 cm was determined visually according to the following criteria. The test was conducted three times, and the average value (rounded down) was taken as the test result, and 4 or more points were accepted.
10 points: A weight of 9.8 N (1 kg weight) leaves no scratches or marks.
7 points: Scratches and marks remain with a weight of 9.8 N (1 kg weight), but no scratch remains with 700 g.
4 points: Scratches and marks remain with a weight of 6.9 N (700 g weight), but no scratch remains with 4.9 N (500 g weight).
1 point: A scratch remains with a weight of 4.9 N (500 g weight).

[Optical quality of laminated film]
One side of a polarizer having a polarization degree of 99.9% prepared by adsorbing and orienting iodine in polyvinyl alcohol, 200 mm in the width direction from the central portion in the width direction of the laminated film (film width of 400 mm), longitudinal direction A sample cut out at a size of 310 mm was pasted through a laminator roll set at 85 ° C. to prepare an evaluation sample. The visibility when the prepared evaluation sample and the polarizing plate on which the laminated film was not bonded was placed on the LED light source (A3-101 manufactured by Tritech) in a crossed Nicol arrangement was confirmed.
10 points: Almost no interference color is seen. Or, no interference color is seen.
7 points: Some interference colors are seen only at the four corners of the sample.
4 points: Some interference color is seen in the entire sample.
1 point: Interference color is clearly seen in part or all of the sample.

  Table 3 summarizes the evaluation results of the finally obtained laminated film.

1 Thickness direction displacement h (μm)
2 Load P (mN)
3 Loading process 4 Unloading process 5 Tangent at the beginning of the unloading process (inclination: contact stiffness)
6 Layer in contact with support substrate 7 Support substrate 8 Layer in contact with layer B at surface layer (A layer)
9 Layer in contact with support substrate (B layer)
DESCRIPTION OF SYMBOLS 10 Support base material 11 Multilayer slide die 12 Multilayer slot die 13 Single layer slot die

  The laminated film of the present invention is required to have particularly high scratch resistance and repeated scratch resistance in applications in which optical quality is important, taking advantage of excellent optical properties, scratch resistance, repeated scratch resistance, and being a thin film. It can be suitably used for applications in which scratches and cracks are less conspicuous.

Claims (6)

A laminated film having a surface layer on at least one of the supporting substrates, wherein the following conditions 1 and 2 are satisfied:
Condition 1: Indentation elastic modulus _{EIT of the} surface layer is 1,500 MPa or less.
Condition 2: The support substrate is a polyester film having a polyester A layer and a polyester B layer, and the polyester B layer satisfies at least one of the following (A) or (B).
(A) About the diol component of the polyester constituting the polyester B layer, the structural unit derived from ethylene glycol is contained in an amount of 60 mol% to 90 mol%, and the structural unit derived from other diol is contained in an amount of 10 mol% to 40 mol%. Become.
(B) About the dicarboxylic acid component of the polyester constituting the polyester B layer, 60 to 90 mol% of structural units derived from terephthalic acid, and 10 to 40 mol% of structural units derived from other dicarboxylic acids Do it. The laminated film according to claim 1, wherein the following condition 3 and condition 4 are satisfied.
Condition 3: The following equation holds for the thickness T _{s of the} surface layer and the thickness T _t of the laminated film.
0.25 ≦ T _s / T _t ≦ 0.80
Condition 4: The following equation holds for the contact rigidity S _{s of the} surface layer and the contact rigidity S _b of the support base.
S _s N / mm <S _b N / mm ≦ 5.0 N / mm The laminated film according to claim 1 or 2, wherein the following condition 5 is satisfied.
Condition 5: contact stiffness _{S s} of the surface layer is 2.0 N / mm or less. The laminated film according to any one of claims 1 to 3, wherein the following condition 6 is satisfied.
Condition 6: The following formula is established for the contact stiffness S _{s of the} surface layer and the contact stiffness S _b of the support substrate.
0.35 ≦ S _s / S _b The laminated film according to any one of claims 1 to 4, wherein the following condition 7 is satisfied.
Condition 7: The thickness T _{t of the} laminated film is 80 μm or less. The laminated film according to any one of claims 1 to 5, wherein the following condition 8 is satisfied.
Condition 8: Retardation in the thickness direction of the laminated film is 1,000 nm or less.

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