JP2019025765A - Laminate, cover film, and production method of laminate - Google Patents

Abstract

To provide a laminate achieving both flexibility and suppression of press marks, and a cover film for display.SOLUTION: A laminate has a surface layer on a substrate and satisfies the following conditions. (A) Total light transmittance of the laminate is 85% or more. (B) The surface layer has at least two glass transition temperatures. (C) When the glass transition temperature of the lowest temperature side is indicated by Tg1 and the glass transition temperature of the highest temperature side is indicated by Tg2, the laminate satisfies relations of Tg1<-5°C and 30°C<Tg2-Tg1<130°C. (D) The laminate has elasticity modulus distribution in the thickness direction of the surface layer and satisfies relations of 3 μm≤Ta≤10 μm, 1 μm≤Tb≤9 μm, and 1.0≤Ta/Tb≤10.0 when integrated thickness of portions with elasticity modulus higher than the average is indicated by Ta13 and integrated thickness of portions with elasticity modulus lower than the average is indicated by Tb14.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a laminate having both flexibility and suppression of imprints, a method for producing the laminate, and a cover film using the laminate.

  Conventionally, for the purpose of surface protection of optical materials such as color filters and flat panel displays (prevention of scratches and imparting antifouling properties), a plastic film “hard coat material” provided with a surface layer made of synthetic resin or the like has been used. The surface coating layer is required to have scratch resistance as an important characteristic. In general, a “high crosslink density material obtained by coating-drying-heating or UV-curing a coating composition containing various prepolymers such as organosilanes and polyfunctional acrylics described in Non-Patent Document 1, oligomers, etc. ”Or“ organic-inorganic hybrid material ”in which various surface-modified fillers are combined to increase the surface hardness of the coating film, thereby imparting scratch resistance.

  On the other hand, in recent years, taking advantage of the light and flexible characteristics of plastic films, not only the display surface of PCs and smartphones, but also the “curved surface protection” of the housing surface and the so-called “flexible device” The use for the housing which is rich in property is progressing. In such applications, in addition to “surface hardness” such as scratch resistance of the surface layer, it is required that both cracking and peeling hardly occur at the time of bending, that is, “flexibility”. In order to achieve both “flexibility” and “scratch resistance”, a coat film using a so-called “self-healing material” that suppresses damage by deformation / restoration of a soft surface layer may be used. “Self-healing material” is a material that has excellent scratch resistance against soft materials such as cloth and relatively light loads, but is rubbed against hard materials such as metal with strong pressure. In such a case, it has a problem that it is easily scratched.

  Furthermore, in the case of the plastic film having “flexibility” as described above, the film is deformed by the pressure caused by bending during handling, the step difference during roll processing, or the pressure applied from the outside during use of the final product. The problem is that “scratches” occur.

  In a hard coat material, as a laminate that focuses on both scratch resistance and flexibility, Patent Document 1 discloses that “hard coat / substrate adhesion, film bending cracks, curls, and the like fall within a practical tolerance. And a hard coat film having a pencil hardness value of 4H or higher is disclosed. Specifically, “a cured resin coating layer comprising a two-layer structure in which a cured resin coating layer composed of a blend of a radical polymerization resin and a cationic polymerization resin and a cured resin coating layer composed only of a radical polymerization resin are formed in this order” Has been proposed.

  On the other hand, Patent Document 2 discloses “a hard coat film that improves surface hardness, prevents damage to the hard coat film due to stress concentration, and is hardly damaged”. Specifically, “the hard coat layer is formed in two or more layers, and the elastic modulus σm of the hard coat layer formed closest to the transparent substrate is higher than the elastic modulus σs of the hard coat layer of the surface layer. Has been proposed.

  Patent Document 3 discloses “a laminate with a hard coat layer that can be easily produced, has excellent film adhesion, and has high film strength and scratch resistance”. Specifically, “a structure in which two layers having different inorganic particle concentrations are alternately stacked, a layer group having a high inorganic particle concentration is an A layer unit, and a layer group having a low inorganic particle concentration is a B layer unit. A layered product with a hard coat layer in which the sum ΣAh of the dry film thickness of the A layer unit and the sum ΣBh of the dry film thickness of the B layer unit satisfy the relationship ΣAh ≧ ΣBh ”is proposed ing.

  On the other hand, Patent Document 4 discloses “a laminate having both high surface hardness and flexibility”. Specifically, “a laminate in which a surface layer is laminated on a support substrate, and in the elastic modulus distribution in the thickness direction of the surface layer, a maximum value whose elastic modulus is higher than the elastic modulus of the support substrate; There is a minimum value where the elastic modulus is lower than the elastic modulus of the supporting substrate, and both the elastic modulus on the interface side with the supporting substrate in the surface layer and the elastic modulus on the outermost surface side are both higher than the elastic modulus of the supporting substrate. A laminate characterized by being high is proposed.

  Furthermore, as an example of a plastic film obtained by laminating resins having different Tg, Patent Document 5 describes “a laminated film for optics having a first layer made of at least one thermoplastic resin and a second layer made of the other thermoplastic resin. An optical laminate characterized by satisfying a relationship of | Tg1-Tg2 | ≧ 100 ° C., where Tg1 is the glass transition temperature of one thermoplastic resin and Tg2 is the glass transition temperature of the other thermoplastic resin. "Film."

JP 2000-071392 A JP 2000-214791 A International Publication No. 2009/130975 Pamphlet International Publication No. 2016/098658 Pamphlet JP 2006-208655 A

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

  The above-mentioned plastic film having “surface hardness” and “flexibility” suppresses scratches on the surface by designing the slipperiness and elastic modulus of the surface of the coat layer. However, the balance between “surface hardness” and “flexibility” is not suitable for hard coat materials, and even if the above conditions are satisfied, the entire film including the base substrate is likely to be deformed by pressing and easily damaged. There are challenges.

  For example, the configuration of Patent Document 1 suppresses “curling” due to shrinkage of the hard coat layer. The configuration of Patent Document 1, that is, “a hard coat film obtained by laminating a coat layer having an elastic modulus in the range of 2.0 GPa to 4.5 GPa on a coat layer having an elastic modulus in the range of 1.5 GPa to 4.5 GPa”. As a result of an investigation by the present inventors, sufficient “flexibility” has not been obtained.

  Further, the configuration proposed in Patent Document 2 is “the elastic modulus σm of the hard coat layer formed closest to the base material is higher than the elastic modulus σs of the hard coat layer of the surface layer”. However, when the present inventors confirmed these structures, it turned out that the surface of a hard-coat layer is easy to be damaged, and it is difficult to apply as a cover film.

  Furthermore, the configuration of Patent Document 3, that is, “a group of inorganic particles having a high inorganic particle concentration of 30.0 vol% or more and 70.0 vol% or less, and an inorganic particle concentration of 0 vol% or more and 40.0 vol% In the following “hard coat layer in which layers having low inorganic particle concentration are alternately laminated”, although the surface hardness is improved, the resin material is selected from highly crosslinkable actinic ray curable resins. It is not designed to be “flexible”.

  On the other hand, the structure proposed in Patent Document 4, that is, “the surface layer includes a maximum value whose elastic modulus is higher than the elastic modulus of the supporting substrate and a minimum value whose elastic modulus is lower than the elastic modulus of the supporting substrate, Both the elastic modulus on the interface side with the supporting substrate and the elastic modulus on the outermost surface side are both higher than the elastic modulus of the supporting substrate. ”Although the film can achieve both surface hardness and flexibility, it is compressed with strong pressure. In this case, it was confirmed that the designed elastic region was deviated and “scratches remained easily” on the coating film.

  In addition, the configuration of Patent Document 5, that is, “an optical laminated film having a first layer made of at least one thermoplastic resin and a second layer made of the other thermoplastic resin” corresponds to the supporting substrate of the present invention. It relates to a film and has not yet been conceived as an integral laminate including a scratch-resistant hard coat layer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a laminate that has both surface hardness necessary for a cover film and sufficient flexibility to withstand use in a flexible device, and also suppresses generation of imprints on the 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 laminate having a surface layer on a supporting substrate, which satisfies all of the following (A) to (C).
(A) The total light transmittance of the laminate is 85% or more. (B) The surface layer has at least two different glass transition points Tg1 and Tg2. Here, the glass transition point on the lowest temperature side is Tg1, (C) satisfying Tg1 ≦ −5 ° C. and 30 ° C. ≦ Tg2−Tg1 ≦ 130 ° C. (2) Thickness direction in a cross section perpendicular to the supporting substrate of the surface layer In the elastic modulus distribution, a portion having a high modulus and a low modulus relative to the average value of the elastic modulus, and the thickness of each portion estimated from the elastic modulus distribution in the thickness direction satisfies the following (D) The laminate according to (1), characterized in that
(D) Satisfying 3 μm ≦ Ta ≦ 10 μm, 1 μm ≦ Tb ≦ 9 μm, and 1.0 ≦ Ta / Tb ≦ 10.0 Ta: Integrated thickness where the elastic modulus is higher than the average value Tb: Average elastic modulus (3) Elasticity E70 with cumulative frequency 70% and elasticity with cumulative frequency 30% in the histogram calculated from the elastic modulus distribution in the thickness direction in the cross section perpendicular to the supporting substrate of the surface layer The cumulative frequency 70% elastic modulus e70 and the elastic modulus e30 with a cumulative frequency of 30% in the histogram calculated from the modulus E30 and the elastic modulus distribution in the direction parallel to the interface in the cross section perpendicular to the support substrate of the surface layer are as follows: (E) is satisfied, The laminate according to (1) or (2).
(E) 100 <[E70 / E30] / [e70 / 30]
(4) A display cover film comprising the laminate according to any one of (1) to (3).
(5) A step of forming a coating film having two or more coating layers by applying two or more kinds of coating compositions on a support substrate by a die coating method (step 1), and applying an active energy ray to the coating film The step of irradiating (step 2), the step of drying the coating film (step 3), and the step of curing the coating film (step 4) are performed in this order once (1) to (4) The manufacturing method of the laminated body in any one of.

  ADVANTAGE OF THE INVENTION According to this invention, in addition to high scratch resistance and flexibility, the laminated body which made compatible generation | occurrence | production suppression of imprints can be provided. The laminated body of the present invention can suppress the occurrence of curling due to stress concentration, cracking during peeling and peeling of the coating film, as well as compression and collision, as compared to a homogeneous resin layer of equivalent thickness. Occurrence of dents and dents can be suppressed. In addition, it is possible to achieve both scratch resistance due to excellent surface hardness.

It is a conceptual diagram of the cross-sectional schematic diagram of the laminated body of this invention, and the elastic modulus distribution of the thickness direction in a cross section. It is a conceptual diagram of the elastic modulus distribution in the thickness direction, the maximum elastic modulus, and the minimum elastic modulus. It is a conceptual diagram of the part whose elastic modulus distribution and elastic modulus of a thickness direction are higher than the elastic modulus of a support base material, and a part whose elastic modulus is lower than the elastic modulus of a support base material. It is an example (multilayer slide die coat) of the manufacturing method which forms a surface layer. It is an example (multilayer slot die coat) of the manufacturing method which forms a surface layer. It is an example (wet-on-wet coat) of the manufacturing method which forms a surface layer. It is an example of the manufacturing process of a laminated body.

  In order to achieve the above-mentioned problem, first, the deformation of the laminated body during pushing was analyzed. There are various types of impact and time scales such as indentation during machining and impact during actual use, but there is a common point that high pressure is concentrated in a very small area such as dots and lines. As a result, the appearance changes due to cracking of the highly elastic material or permanent deformation of the low elastic material.

  Therefore, the present inventors have conceived the design of a restoration phase that recovers the deformation at the time of pushing in with time. Specifically, an attempt was made to restore the imprint marks by using a resin in a rubber-like elastic region near room temperature. However, it has been confirmed that the resin having resilience as described above is vulnerable to scratches caused by a hard material such as metal because of its flexibility. Further, it was found that “scratch resistance” and “scratch resistance” are traded off by simple mixing with the above-mentioned highly crosslinked material, and characteristics satisfying both cannot be obtained.

  The point of the present invention is to achieve both of these characteristics by effectively arranging a material that is highly crosslinked and excellent in “scratch resistance” and a flexible material that has “indentation resistance” so as to satisfy specific physical properties. It has been achieved. As a result of investigations by the present inventors, it has been found that a surface layer that satisfies the conditions described later achieves both high scratch resistance and flexibility, as well as suppression of generation of indentations. Hereinafter, embodiments of the present invention will be described in detail.

[Glass transition point of surface layer]
One of the indexes for evaluating the physical properties of plastic materials is the glass transition point (Tg). This is an index for evaluating the temperature dependence of the mechanical properties of resin, such as the method using a differential scanning calorimeter (DSC) and the dynamic viscoelasticity measurement (DMA) method. It is measured by. In particular, the method using DSC is excellent as a qualitative analysis prescription because analysis is possible even from resin fragments and scraped powder.

  As a characteristic of the resin, since the elastic modulus is relatively low in a temperature region higher than Tg, in the case of a material having a similar resin skeleton, the material having a lower Tg may have a lower room temperature elastic modulus. However, in reality, there is no direct correlation with the elastic modulus at room temperature, and there are materials having different elastic moduli even with the same Tg, and a resin having a relatively low room temperature elastic modulus even if Tg is relatively high. There may also be a combination of

  In general, a highly crosslinked coating film such as a hard coat material is designed using a high elastic modulus in a glassy region. On the other hand, in the case of a so-called self-healing material that recovers scratches over time, its Tg is set just around room temperature, and small dents can be recovered using intermediate physical properties between glass and rubber. . Further, examples of the material having a low Tg include a polymer for an adhesive. Since it greatly exceeds Tg at room temperature, it is a material having tackiness and tackiness.

  On the other hand, when binder materials having different Tg are mixed and cured, the value of Tg generally shifts to an intermediate point according to the mixing ratio. However, in the case where two or more binder components are not completely mixed in the coating film and exist in the form of domains composed of only individual resins, a plurality of Tg may exist in the surface layer. obtain. And in the laminated body of this invention, it confirmed that formation of such a domain was effective in achieving the above-mentioned subject. That is, by specifying the relationship between a plurality of Tg in the surface layer (specifically, a preferable range of Tg1 and a preferable range of Tg2−Tg1, which is a difference between Tg2 and Tg1, which will be described later) As a result of the Tg satisfying the preferable range described later, scratch resistance, impression resistance, and the like can be realized.

  That is, there is a Tg condition to be satisfied in the surface layer of the laminate of the present invention. Specifically, when the surface layer is first analyzed by a differential scanning calorimeter, it is necessary to have at least two different glass transition points Tg1 and Tg2. Here, the glass transition point on the lowest temperature side is Tg1, and the glass transition point on the highest temperature side is Tg2. When one Tg or no Tg exists, the above-described resin design is not performed, and it is impossible to achieve both “scratch resistance” and “scratch resistance”.

  Furthermore, Tg1 satisfies −5 ° C. or lower, and Tg2−Tg1 satisfies 30 ° C. or higher and 130 ° C. or lower. When Tg1 exceeds −5 ° C., the fluidity in the vicinity of room temperature is insufficient, so that the effect of restoring the impressions may not be sufficiently obtained. When Tg2−Tg1 is less than 30 ° C. (specifically, when the above-mentioned hard coat material and self-healing material are used), “scratch resistance” and “scratch resistance” are trade-offs. It may be difficult to achieve both. On the other hand, when Tg2−Tg1 exceeds 130 ° C., the interface between the high Tg phase and the low Tg phase tends to be distorted, and the entire film becomes brittle and mechanical properties may be deteriorated. The glass transition point of the surface layer is a glass transition point when the surface layer is scraped off by the method described in the Examples and measured by DSC. A specific method for measuring the glass transition point using a differential scanning calorimeter will be described later. In this evaluation method, when only one glass transition point is observed due to resin mixing, or there is a Tg bias observed depending on the sampling position. In some cases (specifically, when only one glass transition point is observed in three randomly selected measurements or when Tg2-Tg1 varies by 10 ° C. or more), the present invention Properties such as transparency, scratch resistance, and scratch resistance to be solved cannot be obtained.

[Total light transmittance]
On the other hand, high transparency is desirable for exhibiting good properties as a laminate. When resin materials having different refractive indexes form domains, light reflection or scattering occurs at the interface, which may lead to a decrease in transparency. When used as an image display device with low transparency, image quality may decrease due to a decrease in image saturation, etc., which may lead to deterioration in design such as dullness or discoloration in the case of housing protection There is.

  On the other hand, with respect to scratches and imprints on the surface, the higher the transparency, the more noticeable, and the lower the transparency, the relatively less visible. That is, since the laminate of the present invention has high transparency, it can be said that demands for scratch resistance and indentation resistance are high. Although the total light transmittance can be used for evaluating the transparency of the laminate of the present invention, a haze value or the like can also be used.

  The total light transmittance is an index of light transmittance of the transparent material defined in JIS-K 7361-1 (1997). The higher the light transmittance, the higher the transparency. The total light transmittance of the laminate is 85% or more, more preferably 90% or more. A realistic upper limit is expected to be about 94%. When the total light transmittance is less than 85%, the above-described deterioration in image quality and appearance may be caused.

  The haze value is an index of turbidity of the transparent material defined in JIS-K 7136 (2000). The smaller the haze value, the higher the transparency. The haze value (Hz) of the laminate is preferably used as an indicator of the visibility of the display material, preferably 1.5% or less, more preferably 1.0% or less, still more preferably 0.5% or less. The smaller the value, the better the transparency, but it is difficult to make it 0%, and the realistic lower limit is considered to be about 0.01%. If the haze is greater than 1.5%, there is a possibility that image deterioration is likely to occur.

[Elastic modulus of surface layer in cross section perpendicular to supporting substrate]
Then, the preferable range of the elasticity modulus in the cross section perpendicular | vertical to the support base material of the surface layer which the laminated body of this invention has is demonstrated using figures. First, the laminated body of this invention is the laminated body 3 by which the surface layer 2 was laminated | stacked on one surface of the support base material 1, as shown in FIG. And since the surface layer 2 has two or more domains having different Tg in its cross section, the elastic modulus is not constant and exists with a certain distribution.

  On the other hand, the “elastic modulus of the cross section of the laminate” in the present invention is measured by an atomic force microscope. Elastic modulus measurement with an atomic force microscope is a compression test with a probe of a very small portion, and measures the degree of deformation due to pressing force. Therefore, the elastic modulus in the cross section of the surface layer is measured using a cantilever with a known spring constant. Specifically, the laminate is cut, and the elastic modulus in the cross section at each position in the thickness direction of the surface layer is measured with an atomic force microscope. Details will be described in the Examples section, but the cantilever obtained by using the atomic force microscope shown below, contacting the tip of the cantilever tip to the cross section of the surface layer, and measuring the force curve with a pressing force of 55 nN Can be measured.

Atomic force microscope: MFP-3DSA-J manufactured by Asylum Technology
Cantilever: A cantilever “R150-NCL-10 manufactured by NANOSENSORS (material Si, spring constant 48 N / m, radius of curvature of the tip 150 nm).

  At this time, the spatial resolution depends on the scanning range of the atomic force microscope and the number of scanning lines, but under realistic measurement conditions, about 50 nm is the lower limit. Details of the measurement method will be described later, but typical parameters will be described.

[Average value of elastic modulus in surface layer]
A region attributed to the surface layer is extracted from the measured elastic modulus mapping, and the average value can be treated as a physical property value representing the surface layer.

[Elastic modulus distribution in the thickness direction, elastic modulus distribution in the direction parallel to the interface]
By measuring the elastic modulus of the cross section of the laminate using the above-described atomic force microscope, it is possible to obtain a mapping image in which the elastic modulus is evaluated with respect to lattice-like measurement points in the cross section of the laminate. Using this elastic modulus map, it is possible to evaluate the average information of the surface layer and the bias of the elastic modulus distribution with respect to an arbitrary orientation. For example, as shown in FIG. 2, the distribution of the elastic modulus with respect to the thickness direction (that is, the depth) of the surface layer and the distribution of the elastic modulus with respect to the distance in the direction parallel to the interface between the surface layer and the supporting substrate are extracted. be able to.

[Histogram calculated from elastic modulus distribution]
Based on the elastic modulus distribution data for each predetermined distance in the specific orientation, a histogram of the elastic modulus distribution with respect to the specific direction can be created. The histogram is useful for evaluating the degree of variation in elastic modulus and the characteristics formed by two or more domains.
Hereinafter, a preferable mode of the elastic modulus distribution of the surface layer will be described.

[Thickness of high elastic modulus, thickness of low elastic modulus]
There is a preferable relationship between the elastic modulus and the thickness as a structure that relaxes the impression mark when the laminate is pushed. Specifically, in the elastic modulus distribution in the thickness direction with respect to an arbitrary point of the surface layer, as shown in FIG. 3, there are a portion where the elastic modulus is higher and lower than the average elastic modulus 8 in the surface layer. Is preferred. Further, in the elastic modulus distribution in the thickness direction of the surface layer, as shown in FIG. 3, the integrated thickness of the portion 13 where the elastic modulus is higher than the average value 8 of the elastic modulus in the surface layer, and the elastic modulus in the surface layer It is more preferable that the integrated thickness of the thickness 14 of the portion lower than the average value 8 of the elastic modulus satisfies the following relationship. (D) 3 μm ≦ Ta ≦ 10 μm, 1 μm ≦ Tb ≦ 9 μm, and 1.0 ≦ Ta / Tb ≦ 10.0, that is, the portion where the elastic modulus is higher than the average value The cumulative thickness Ta is 3 μm or more and 10 μm or less, and the cumulative thickness Tb of the portion where the elastic modulus is lower than the average value is preferably 1 μm or more and 9 μm or less, and Ta / Tb is 1.0 or more and 10.0 or less. .

  When Ta is less than 3 μm, sufficient surface hardness cannot be obtained, and scratches may be easily formed, and when it exceeds 10 μm, flexibility may be impaired. On the other hand, when Tb is less than 1 μm, it may be difficult to obtain the restoring property of the stamp mark, and when it exceeds 9 μm, the surface layer may be easily damaged. When Ta / Tb is less than 1.0, flexibility may be impaired. When Ta / Tb exceeds 10.0, imprint marks may remain easily.

[Elastic modulus E30, e30 with cumulative frequency 30% and elastic modulus E70, e70 with cumulative frequency 70%]
The laminate of the present invention has a preferable elastic modulus distribution when both the transparency and glass transition point of the laminate are satisfied. Specifically, an elastic modulus E70 having a cumulative frequency of 70% and an elastic modulus E30 having a cumulative frequency of 30% in the histogram calculated from the elastic modulus distribution in the thickness direction in a cross section perpendicular to the supporting base material of the surface layer, and the surface The cumulative frequency 70% elastic modulus e70 and the elastic modulus e30 of the cumulative frequency 30% in the histogram calculated from the elastic modulus distribution in the direction parallel to the interface in the cross section perpendicular to the supporting substrate of the layer satisfy the following (E): It is preferable.
(E) 100 <[E70 / E30] / [e70 / e30].

  (E) is the cumulative frequency distribution E (X) of the elastic modulus distribution in the thickness direction in the cross section perpendicular to the supporting substrate and the elastic modulus in the direction parallel to the interface of the surface layer in the cross section perpendicular to the supporting substrate. In the cumulative frequency distribution e (X) of the distribution, E (X) means that the value variation is larger than 100 times. That is, the distribution of resins having different glass transition points is anisotropic. It means that a layered structure laminated in the thickness direction is particularly preferable. The elastic modulus of the surface layer may be a laminate in which a plurality of layers having different elastic moduli are laminated as long as the above-described conditions are satisfied, and the elastic modulus is different in the thickness direction in the same layer. Such a layer may be used. When the above (E) is not satisfied, that is, when [E70 / E30] / [e70 / e30] is 100 or less, the effect of suppressing the indentation cannot be obtained uniformly in the surface, resulting in the indentation. May be easily attached.

[Laminated body and surface layer]
The “surface layer” in the present invention refers to a layer formed on a support substrate, and a combination of all the series of layers including the surface layer and the support substrate is referred to as a “laminate”. That is, when only one layer is formed on the support base material, the one layer becomes a “surface layer”. For example, when two or more layers are formed on a supporting base material, all the two or more layers excluding the supporting base material are referred to as one “surface layer”.

  Here, the “layer” refers to a part having a finite thickness that can be distinguished by having a boundary surface and a part adjacent to the part in the thickness direction from the surface side of the laminate in the thickness direction. More specifically, when the cross section of the said laminated body is cross-sectional-observed with an electron microscope (a transmission type, a scanning type) or an optical microscope, it points out what is distinguished by the presence or absence of a discontinuous interface. The laminate 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-mentioned physical properties. The thickness of the entire laminate is not particularly limited, but is preferably 10 μm or more and 300 μm or less, and more preferably 50 μm or more and 280 μm or less.

  The laminate is an object of the present invention, in addition to the scratch resistance, particularly the repeated scratch resistance and flexibility, as well as antifouling properties, antireflection properties, antistatic properties, antifouling properties, electrical conductivity, and heat ray reflectivity. It may have a layer having other functions such as near infrared absorptivity, electromagnetic wave shielding, easy adhesion, etc., and these functions may be imparted to the surface layer as long as they are within the range of each physical quantity. .

[Supporting substrate]
The material constituting the support substrate used in the laminate 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. More preferably, the resin constituting the support substrate is preferably a thermoplastic resin from the viewpoint of moldability.

  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, polyester resins, polycarbonate resins and polyarylate resins. Fluorine resins such as polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, trifluoroethylene resin, tetrafluoroethylene-6-fluoropropylene copolymer, vinylidene fluoride resin, acrylic Resins, methacrylic resins, polyacetal resins, polyglycolic acid resins, polylactic acid resins, 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 or a polyamide, an aromatic polyamide, a polyimide, an aromatic polyimide, a polyamideimide, an aromatic polyamideimide, a polycarbonate resin, or a methacrylic resin from the viewpoint of strength, heat resistance, and transparency. Preferably, polyester resin is more preferable from the viewpoint of transparency and coloring, and from the viewpoint of strength and heat resistance, at least selected from the group consisting of polyamide, aromatic polyamide, polyimide, aromatic polyimide, polyamideimide and aromatic polyamideimide A film that is one kind of resin is particularly preferable.

  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.

  Hereinafter, a polyamide film or an example using a polyamide film as a film that is at least one resin selected from the group consisting of polyamide, aromatic polyamide, polyimide, aromatic polyimide, polyamideimide, and aromatic polyamideimide will be described. However, the present invention is not limited to this.

  Various methods can be used as a method for obtaining a polyamide solution, that is, a film forming stock solution. For example, a low temperature solution polymerization method, an interfacial polymerization method, a melt polymerization method, a solid phase polymerization method, and the like can be used. When it is obtained from a low temperature solution polymerization method, that is, from carboxylic acid dichloride and diamine, it is synthesized in an aprotic organic polar solvent.

  Carboxylic acid dichlorides include terephthalic acid dichloride, 2 chloro-terephthalic acid dichloride, 2 fluoro-terephthalic acid dichloride, isophthalic acid dichloride, naphthalene dicarbonyl chloride, 4,4′-biphenyl dicarbonyl chloride, terphenyl dicarbonyl chloride, 1, Examples include 4-cyclohexanedicarboxylic acid chloride, 1,3-cyclohexanedicarboxylic acid chloride, and 2,6-decalin dicarboxylic acid chloride, and preferably 1,4-cyclohexanedicarboxylic acid chloride, terephthalic acid dichloride, 4,4′- Biphenyl dicarbonyl chloride and isophthalic acid dichloride are used.

  Examples of the diamine include 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, and 2,2′-ditrifluoromethyl-4,4. '-Diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) fluorene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis (4-Aminophenyl) hexafluoropropane, o-tolidine, 2,2'-dimethyl-4,4'- Examples thereof include aminobiphenyl (m-tolidine), 1,1-bis (4-aminophenyl) cyclohexane, 3,3 ′, 5,5′-tetramethylbenzidine, and the like, preferably 2,2′-ditrifluoromethyl. -4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl sulfone. Polyamide solution uses acid dichloride and diamine as monomers to produce hydrogen chloride as a by-product. When neutralizing this, inorganic neutralizers such as calcium hydroxide, calcium carbonate, lithium carbonate, and ethylene Organic neutralizers such as oxide, propylene oxide, ammonia, triethylamine, triethanolamine, diethanolamine are used. The reaction between isocyanate and carboxylic acid is carried out in an aprotic organic polar solvent in the presence of a catalyst.

  When diamine and dicarboxylic acid dichloride are used as raw materials, they are amine terminals or carboxylic acid terminals depending on the composition ratio of the raw materials. Alternatively, the end capping may be performed with other amine, carboxylic acid chloride, or carboxylic acid anhydride.

  Compounds used for end-capping include benzoyl chloride, substituted benzoyl chloride, acetic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 4-ethynylaniline, 4-phenylethynylphthalic anhydride, maleic anhydride, etc. It can be illustrated.

  Examples of the aprotic polar solvent used in the production of polyamide include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, and N, N. Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol , Phenolic solvents such as halogenated phenols and catechols, hexamethylphosphoramide, γ-butyrolactone, etc., and these are preferably used alone or as a mixture. Tribe The use of hydrogen is possible. Furthermore, for the purpose of accelerating the dissolution of the polymer, 50% by mass or less of an alkali metal or alkaline earth metal salt can be added to the solvent.

  The film-forming stock solution prepared as described above is formed into a film by a so-called solution casting method. The solution casting method includes a dry-wet method, a dry method, a wet method, etc., and any method may be used, but here, the dry-wet method will be described as an example.

  In the case of forming a film by a dry-wet method, the stock solution is extruded from a die onto a support such as a drum, an endless belt, or a support film to form a thin film, and then dried until the thin film layer has self-holding property. Drying conditions can be performed in the range of room temperature to 220 ° C. and within 60 minutes, for example. Further, the smoother the surface of the drum, endless belt, and support film used in this drying step, the smoother the surface. The film (sheet) that has been subjected to the dry process is peeled off from the support and introduced into the wet process, where desalting and solvent removal are performed, and further, stretching, drying, and heat treatment are performed to form a film. The heat treatment temperature is preferably 280 to 340 ° C, more preferably 300 to 320 ° C, from the viewpoint of strength and heat resistance described above. If it exceeds 340 ° C., yellowness (YI) may increase. The heat treatment time is preferably 30 seconds or longer, more preferably 1 minute or longer, still more preferably 3 minutes or longer, more preferably 5 minutes or longer. The heat treatment is preferably performed in an inert atmosphere such as nitrogen or argon.

  A base film made of any one of polyamide, aromatic polyamide, and polyimide containing fluorine in the polymer structure can also be used as a laminated film. As the production method, it is preferable to use a dry-wet process of a solution film-forming method in which an organic solvent solution of a resin is extruded from a die and cast on a support, and is dried, solvent-extracted and heat-set, and a laminated film is produced. In this case, at any stage of this process, the organic solvent solution of the resin composition comprising any one of polyamide, aromatic polyamide, and polyimide containing fluorine in the polymer structure is placed before or in the die. Lamination and casting to a support. Examples of a method of laminating in front of the die include a method of laminating using a laminating apparatus called a pinole, a composite tube, or a feed block. Moreover, as a method of laminating in the die, a method using a multilayer die or a multi-manifold die can be mentioned. An organic solvent solution of a resin and an organic solvent solution of a polymer (resin composition) such as an aromatic polyamide often have different solution viscosities. For this reason, it may be difficult to obtain a good laminated structure by a method of laminating before a die such as pinol. For this reason, it is preferable to laminate using a multi-manifold base.

  As the method for producing the film, from the viewpoint of the strength and heat resistance described above, the longitudinal direction of the film (the film-conveying direction; hereinafter referred to as MD) and the width direction (the direction perpendicular to the longitudinal direction in the film plane. (It may be called TD) It is preferable to extend | stretch by the draw ratio of 1.05 times or more and 10.0 times or less. The draw ratio in the MD direction is preferably 1.05 times to 5.0 times, more preferably 1.05 times to 3.0 times, still more preferably 1.05 times to 2.00 times, most preferably It is 1.05 times or more and 1.50 times or less. The draw ratio in the TD direction is preferably 1.05 times to 5.0 times, more preferably 1.05 times to 3.00 times, still more preferably 1.05 times to 2.00 times, most preferably It is 1.05 times or more and 1.50 times or less. Further, the draw ratio in the TD direction is preferably 1.0 times or more and 1.5 times or less with respect to the draw ratio in the MD direction. More preferably, it is 1.05 times or more and 1.20 times or less, and most preferably 1.1 times or more and 1.15 times or less.

  The structure of the film is determined by its raw materials. In the case of conducting a structural analysis of a film whose raw material is unknown, mass spectrometry, analysis by a nuclear magnetic resonance method, spectroscopic analysis, or the like can be used.

  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. In this case, it is preferable to provide an easy adhesion layer. In addition, as long as these functional layers can be distinguished as the above-mentioned “layers”, they are all handled as a part of the surface layer, not the supporting base material.

[Manufacturing method of laminate]
The production method of the laminate of the present invention is not particularly limited, and examples thereof include a method of dividing a domain with a resin emulsion and a method of laminating different surface layers by sequential coating and lamination. A coating film is formed by coating more than one type of coating composition in the thickness direction on a supporting substrate to form a coating film, and then immediately partially polymerizing the components in the coating composition. And a method of suppressing the mass transfer caused by the concentration gradient of the components in the coating film and the mass transfer accompanying the diffusion of the solvent due to the drying of the coating film.

  Furthermore, after removing the solvent in the coating film in the drying step, the method of polymerizing the remaining portions of the components in the coating composition to cure the coating film creates a surface layer having the desired specific glass transition point. Is preferable.

  Specifically, two or more kinds of coating compositions described later are applied on a supporting substrate by a die coating method to form a coating film having two or more coating layers (step 1), and the coating film A process for producing a laminate is preferred in which the step of irradiating active energy rays (step 2), the step of drying the coating film (step 3), and the step of curing the coating film (step 4) are performed once in this order. By performing the steps 1 to 4 in this order, the mutual diffusion of the components constituting each coating layer in the coating film can be controlled, whereby the thickness direction of the surface layer of the laminate is defined by the elastic modulus. It is preferable for providing a specific structure.

  Here, the coating layer refers to a “liquid layer” formed by an individual coating composition applied on a supporting substrate, and the “coating layer” refers to the entire coating layer formed on the supporting substrate. In other words, the coating film becomes a “surface layer” by going from the liquid to solid through the above-mentioned drying and curing processes. The definition of the coating composition and the layer will be described later.

  In the method for producing a laminate of the present invention, step 1 is a step of forming a coating film having two or more coating layers on a supporting substrate, and two or more types of coating compositions are formed by a die coating method. Apply on top to form a coating. In the die coating method, each coating composition is ejected in layers through the die slot, and is applied after being laminated on the slide surface to form a coating film consisting of a plurality of coating layers. (FIG. 4) or “multilayer slot die coating” in which a coating film composed of a plurality of coating layers is formed simultaneously with coating on a substrate by supplying a plurality of coating compositions to a die having a plurality of slots (FIG. 5). ) After forming one coating layer on the support substrate, the other coating layer is laminated in an undried state to form a coating film such as “wet-on-wet coating” (FIG. 6), etc. Either is acceptable.

  Hereinafter, examples of various die coating methods and coating layers will be described with reference to the drawings.

  FIG. 4 shows an example of a multilayer slide die coat and shows a cross-sectional view of simultaneous application of four layers. The coating composition forming each coating layer is supplied to the most upstream slot 18, the second slot 19 from the upstream side, the third slot 20 from the upstream side, and the most downstream slot 21 of the four-layer slide die 17. And discharged onto the slide surface 22. Since the slide surface is inclined, the discharged coating compositions are stacked in the process of flowing down on the slide surface. The supporting substrate is conveyed from the upstream side 24 toward the downstream side 25, and the coating composition flowing down the slide surface 22 by the die lip 23 is applied onto the supporting substrate, and four coating layers are formed on the supporting substrate. The coating film which has is formed.

  FIG. 5 is a cross-sectional view of simultaneous application of two layers as an example of a multilayer slot die coat. The coating composition forming each coating layer is supplied to the upstream slot 27 and the downstream slot 28 of the two-layer slot die 26. These coating compositions are discharged from the slot and then merge at the die lip portion 29.

  The support base material is coated on the support base material by the die lip portion 29 that is conveyed from the upstream side 30 toward the downstream side 31 to form a coating film having two coating layers.

  FIG. 6 is a cross-sectional view showing an example of a wet-on-wet coat. In this example, the coating composition for forming each coating layer is supplied to the upstream single-layer slot die 32 and the downstream single-layer slot die 33. First, the coating composition discharged from the upstream single-layer slot die 32 is applied onto a support substrate that is transported from the upstream side 34 toward the downstream side 35 of the support substrate, so that one coating layer is formed. The coating film which has is formed. Next, the coating composition discharged from the downstream single-layer slot die 33 is applied onto the coating film applied from the single-layer slot die 32 to form a coating film having two coating layers.

  In the method for producing a laminate of the present invention, among the two or more coating compositions applied in step 1, at least one coating composition may contain two or more photopolymerization initiators having different absorption wavelength ranges. Preferably, among the two or more types of coating compositions, at least one type of coating composition preferably contains at least one photopolymerization initiator having an absorption maximum wavelength at a wavelength of 350 nm or more.

  The reason why the coating composition preferably contains two or more photopolymerization initiators having different absorption wavelength ranges is that the components in the coating film are partially polymerized in step 2 and the portion remaining in the coating film in step 4 This is because it is necessary to polymerize, and it is necessary to use different photopolymerization initiators at each stage.

  As described above, when at least one of the coating compositions of the coating composition contains the specific photopolymerization initiator, it becomes easy to provide a specific composition gradient structure defined by the elastic modulus in the thickness direction of the surface layer.

  In the method for producing a laminate of the present invention, step 2 is to irradiate the coating film formed on the supporting substrate in the previous step with active energy rays. It is important that the step 2 is performed immediately after coating and before the drying step in which the coating film contains a solvent. The reason for this is that the coating formed on the support base material hardly evaporates in the solvent immediately after coating, so the mass transfer of each component contained in each coating layer does not progress much, When active energy rays are irradiated in this state, the liquid viscosity of the entire coating film can be increased by polymerizing a material that causes a polymerization reaction with the active energy rays in the coating film.

  By increasing the liquid viscosity of the entire coating film, the substances that occur when the solvent in the coating film diffuses to the surface during mass transfer due to the concentration gradient of each substance in the coating film in Step 3 or the drying process Movement can be suppressed. Furthermore, since the degree of mass transfer of each component contained in each coating layer can be adjusted by appropriately adjusting the irradiation conditions of the active energy rays, the specific composition gradient structure of the present invention can be obtained. .

  When step 2 is not performed, a coating film having a plurality of coating layers is formed and then a drying process is entered. Therefore, mass transfer in a direction to eliminate the concentration gradient of components in the coating film in the drying process. In addition, mass transfer accompanying the diffusion of the solvent may progress, and it may be difficult to form a composition gradient structure in the surface layer.

  In the step 2, the active energy rays to be irradiated are preferably electron beams or ultraviolet rays, and more preferably ultraviolet rays. The light source of the active energy ray irradiated for thickening the coating film is not particularly limited. For example, in the case of ultraviolet rays, a UV-LED lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, There are those using a xenon lamp or the like as a light source, and two or more of these may be used.

  In the step 2, there is a preferable region in the integrated spectral distribution of the active energy rays to be irradiated, and the median value of the integrated spectral distribution is preferably 350 nm or more, more preferably 350 to 450 nm, still more preferably 350. ~ 400 nm.

  By setting the median of the integrated spectral distribution of the active energy rays irradiated in the step 2 to 350 nm or more, the irradiation wavelength of the active energy rays used when the coating film is cured in the step 4 described later can be shifted. Therefore, sufficient energy for curing can be given in Step 4.

  The reason why a specific photopolymerization initiator is used in at least one coating composition of two or more coating compositions used in the above-described step 1 is that the active energy with which one photopolymerization initiator is irradiated in step 2 It corresponds to the irradiation of the line.

  In step 2, the spectral distribution of the active energy ray to be irradiated may be any of a single wavelength, an emission line spectrum, and a continuous spectrum, but is preferably a single wavelength spectral distribution. Furthermore, in the said process 2, it is preferable that the full width at half maximum of the spectral distribution of the active energy ray to irradiate is 20 nm or less. By using an active energy ray having a spectral distribution with a full width at half maximum of 20 nm or less, one of the photopolymerization initiators can be selectively excited and cleaved. It becomes easy to express. Here, the “median value of the integrated spectral distribution” means the value of the wavelength when the spectral distribution is represented by an integral curve and the area is exactly half. The “full width at half maximum” means an interval between two points having a relative radiation intensity of ½ intensity of the maximum value in a single wavelength spectral distribution.

In the step 2, since the irradiation amount of the active energy ray to be irradiated varies depending on the kind of the coating composition, the thickness of the coating layer, and the like, a preferable condition is appropriately selected, but there is no particular limitation as long as the coating film can be thickened. An irradiation intensity of 1 to 3000 mW / cm ² and an integrated light quantity of 5 to 500 mJ / cm ² are preferable.

In Step 2, by setting the irradiation intensity and the integrated light amount to 1 mW / cm ² or more and 5 mJ / cm ² or more, respectively, mass transfer due to the concentration gradient of components in the coating film and diffusion of the solvent due to drying of the coating film In order to suppress the accompanying mass transfer, the viscosity of the coating film can be increased to an appropriate region, which is preferable in producing a surface layer having a specific composition gradient structure for a specific purpose.

Moreover, excessive thickening of the coating film can be avoided by setting the irradiation intensity of the active energy ray and the integrated light amount of the active energy ray to 3,000 mW / cm ² or less and 500 mJ / cm ² or less. It is possible to ensure the diffusion state of the solvent necessary for drying the coating film and to flatten the coating film.

  In the production method of the present invention, step 3 is a step of drying the coating film. In the step 3, in addition to removing the solvent contained in the coating film, it is preferable to heat the coating film in order to improve the adhesion of the coating layer to the supporting substrate. Examples of the drying method include heat transfer drying (adherence to a high-temperature object), convection heat transfer (hot air), radiant heat transfer (infrared ray), and others (microwave, induction heating). Among these, in the production method of the present invention, since it is preferable to make the drying rate uniform even in the width direction, a method using convective heat transfer or radiant heat transfer is preferable. When drying by convective heat transfer, the temperature of the hot air is preferably in the range of room temperature to 200 ° C, more preferably 60 ° C to 200 ° C, and still more preferably 80 ° C to 180 ° C.

  In the production method of the present invention, step 4 is a step of curing the coating film. In the step 4, it is preferable to cure the coating film by irradiation with heat or active energy rays. When curing with heat in the curing step, the temperature is preferably from room temperature to 200 ° C, more preferably from 60 ° C to 200 ° C, and even more preferably from 80 ° C to 180 ° C, from the viewpoint of the activation energy of the curing reaction. It is as follows. In the case of curing with active energy rays, electron beams and / or ultraviolet rays are preferred from the viewpoint of versatility, and ultraviolet rays are more preferred.

Further, when curing with ultraviolet rays in step 4, it is preferable that the oxygen concentration is as low as possible because oxygen inhibition can be prevented, and it is more preferable to cure in a nitrogen atmosphere. By lowering the oxygen concentration, the polymerization reaction on the outermost surface becomes difficult to be inhibited, it becomes easy to cure sufficiently, and the scratch resistance and alkali resistance are hardly 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 UV curing is performed using a high-pressure mercury lamp that is a discharge lamp method, it is more preferable to perform UV irradiation under the condition that the illuminance of UV is 100 to 3,000 mW / cm ² .

  Here, the ultraviolet illuminance 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 of the irradiated object that passes under the light source. 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 conveyance speed of the irradiated object passing under the light source, and is proportional to the number of times of irradiation and the number of lamps.

[Coating composition]
The laminate of the present invention forms a surface layer having a structure capable of achieving the above-mentioned physical properties by applying, drying and curing the coating composition on the support substrate using the above-described laminate production method. can do. 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.

  The surface layer of the present invention uses at least two types of coating compositions of the coating composition A capable of imparting the above-mentioned “scratch resistance” and the coating composition B capable of imparting “indentation resistance”. It is preferable to form them by applying them sequentially or simultaneously.

[Coating composition A]
As the coating composition A containing a high Tg component, a hard coat coating material that forms a coating layer having a high elastic modulus can be suitably used. The glass transition point of the single-layer coating layer is preferably 20 ° C to 150 ° C. As specific components, it is preferable to have a highly crosslinkable binder component containing many reactive sites and a particle component. It is preferable to include a highly crosslinkable binder composed of inorganic particles having a high elastic modulus and an organic compound. Preferred particle components and binder components will be described later. For example, as a coating material capable of forming a hard coat layer having a high elastic modulus, a composite coating material of an organic material and an inorganic material called an organic-inorganic hybrid coating material can be used. Examples of organic-inorganic hybrid coatings include “Taisei Fine Chemical Co., Ltd .; (Organic-Inorganic Hybrid Coating Material“ STR-SiA ”)” and “Toagosei Co., Ltd .; (trade name“ Photocuring SQ Series ”)” And “Toyo Ink Co., Ltd. (trade name“ Rioduras ”(registered trademark))”.

[Coating composition B]
As the coating composition B containing a low Tg component, a resin coating rich in flexibility and moldability can be suitably used. The glass transition point of the coating layer single film preferably has -5 ° C to -60 ° C. Specifically, modified acrylates and various polymers used as the main component of acrylic pressure-sensitive adhesives can be used.

  Examples of specific materials include “Daicel Ornex Co., Ltd .; Urethane Acrylate EBECRYL Series”, “Taisei Fine Chemical Co., Ltd .; Acrylic Polymers 8KX Series, 8UA Series”, “Nippon Synthetic Chemical Industry Co., Ltd .; Etc.

  Although it is possible to use a paint designed as an adhesive, it is more preferable to use a binder raw material because streaks or the like are likely to occur during lamination coating. A preferable paint component will be described later.

[Particulate material, particle component]
The surface layer of the laminate of the present invention preferably contains a particle component. In particular, the coating composition A suitable for forming the surface layer of the present invention preferably contains hard inorganic particles. On the other hand, organic particles imparting flexibility can be added to the coating composition B. Here, the particles may be either inorganic particles or organic particles, but inorganic particles are preferred from the viewpoint of durability.

  The number of types of inorganic particles is preferably 1 or more and 20 or less. The number of types of inorganic particles is more preferably 1 or more and 10 or less, and particularly preferably 1 or more and 4 or less. Here, “inorganic particles” include those subjected to surface treatment. This surface treatment means introducing a compound onto the particle surface by chemical bonds (including covalent bonds, hydrogen bonds, ionic bonds, van der Waals bonds, hydrophobic bonds, etc.) and adsorption (including physical adsorption and chemical adsorption). Point to.

Here, the kind of inorganic particles is determined by the kind of elements constituting the inorganic particles, and when some surface treatment is performed, the kind is determined by the kind of elements constituting the particles before the surface treatment. For example, since titanium oxide (TiO ₂ ) and nitrogen-doped titanium oxide (TiO _2−x N _x ) in which part of oxygen in titanium oxide is replaced with nitrogen as an anion, the elements constituting the inorganic particles are different, Different types of inorganic particles. Further, if particles (ZnO) consisting only of the same element, for example, Zn and O, even if there are a plurality of particles having different number average particle diameters, and the composition ratio of Zn and O is different, These are the same type of particles. Even if there are a plurality of Zn particles having different oxidation numbers, as long as the elements constituting the particles are the same (in this example, all elements other than Zn are the same), these are the same kind of particles. .

  In addition, the particles contained in the coating composition suitable for forming the surface layer of the present invention change its surface state by heat, ionizing radiation or the like in a process such as coating, drying, curing or vapor deposition. And is included in the surface layer. Here, the particles present in the coating composition used in the present invention are “particulate material”, and the coating composition is present in the surface layer formed by a process such as coating, drying, curing or vapor deposition. The particles are called “particle components”.

  The inorganic particles are not particularly limited, but are preferably metal or metalloid oxides, nitrides, borides, chlorides, carbonates, sulfates, composite oxides containing two metals, metalloids, Different elements may be introduced between the lattices, lattice points may be replaced with different elements, or lattice defects may be introduced.

  The inorganic particles are oxide particles in which at least one metal or semimetal selected from the group consisting of Si, Al, Ca, Zn, Ga, Mg, Zr, Ti, In, Sb, Sn, Ba, and Ce is oxidized. More preferably.

Specifically, silica (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), indium oxide (In ₂ O ₃ ), tin oxide It is at least one metal oxide or semimetal oxide selected from the group consisting of (SnO ₂ ), antimony oxide (Sb ₂ O ₃ ), and indium tin oxide (In ₂ O ₃ ). Particularly preferred is silica (SiO ₂ ).

  As the particle component of the coating composition for forming the surface layer of the present invention, it is particularly preferable that the surface modification necessary for stably dispersing silica in the good solvent of the binder raw material is made. For example, when an acrylic monomer or oligomer is used as the binder material, the surface modification requires an alkyl group having 1 to 5 carbon atoms, an alkenyl group, a vinyl group, a (meth) acryl group, etc. It is preferable that it is introduced on the surface.

  Here, the number average particle diameter of the inorganic particles means the number-based arithmetic average length diameter described in JIS Z8819-2 (2001). In both the particle component and the particle material, the primary particles are observed using a scanning electron microscope (SEM), a transmission electron microscope, etc., and the diameter of the circumscribed circle of each primary particle is defined as the particle diameter. Refers to the calculated value. In the case of a laminate, the number average particle diameter can be determined by observing the surface or cross section. In the case of a coating composition, the coating composition diluted with a solvent is dropped and dried. Thus, it is possible to prepare and observe a sample.

[Binder material, binder component]
The coating composition suitable for forming the surface layer of the present invention preferably contains a binder raw material. Here, the binder refers to a compound having a reactive site or a higher order compound formed by the reaction. Here, the binder present in the coating composition used in the present invention is “binder material”, and the binder present in the surface layer formed by coating, drying, curing treatment, vapor deposition or the like of the coating composition. Is called “binder component”. The reactive site refers to a site that reacts with other components by external energy such as heat or light. Among such reactive sites, preferred are silanol groups in which alkoxysilyl groups and alkoxysilyl groups are hydrolyzed from the viewpoint of reactivity, carboxyl groups, hydroxyl groups, epoxy groups, vinyl groups, allyl groups, acryloyl groups, And a methacryloyl group. The coating composition A suitable for forming the surface layer of the present invention preferably contains a “highly crosslinkable binder” described later, and the coating composition B preferably contains at least a “flexible binder” described later. May be contained simultaneously.

[Highly crosslinkable binder]
The highly crosslinkable binder can be suitably used mainly as a binder component of the coating composition A, and may be contained in the coating composition B from the viewpoint of improving adhesion and film forming property. A material having 2 or more and 20 or less reactive sites in one molecule is preferable. Moreover, either a thermosetting resin or an ultraviolet curable resin may be used, and two or more kinds of blends may be used, but an ultraviolet curable resin is particularly preferable from the viewpoint of a preferable production method. The glass transition point of the binder component is preferably 20 ° C to 150 ° C. When the temperature is lower than 20 ° C., sufficient scratch resistance cannot be obtained, and when the temperature exceeds 150 ° C. or cannot be measured as a clear peak, the coating film becomes brittle, and flexibility and scratch resistance may decrease. is there.

  Suitable UV curable resins in the highly crosslinkable binder are preferably polyfunctional acrylate monomers, oligomers, alkoxysilanes, alkoxysilane hydrolysates, alkoxysilane oligomers, urethane acrylate oligomers, etc., and polyfunctional acrylate monomers, oligomers, urethane acrylate oligomers. Is more preferable.

  Examples of the polyfunctional acrylate monomer include polyfunctional acrylates having two or more (meth) acryloyloxy groups in one molecule and modified polymers thereof. Specific examples include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate hexanemethylene diisocyanate urethane polymer, and the like can be used. These monomers can be used alone or in combination of two or more.

  Commercially available polyfunctional acrylic compositions include Mitsubishi Rayon Co., Ltd. (trade name “Diabeam” (registered trademark) series, etc.), Nippon Synthetic Chemical Industry Co., Ltd. (trade name “SHIKOH” (registered trademark)). ) Series), Nagase Sangyo Co., Ltd .; (trade name “Denacol” (registered trademark) series, etc.), Shin-Nakamura Chemical Co., Ltd. (trade name “NK ester” series, etc.), DIC Corporation; "(Registered trademark) etc.), Toagosei Co., Ltd .; (" Aronix "(registered trademark) series, etc.), NOF Corporation; (" Blemmer "(registered trademark) series, etc.), Nippon Kayaku Co., Ltd .; Name “KAYARAD” (registered trademark) series, etc.), Kyoeisha Chemical Co., Ltd. (trade name “light ester” series, etc.) It is possible to use these products.

[Flexible binder]
The flexible binder can be suitably used mainly as a binder component of the coating composition B. The glass transition point of the binder component is preferably -60 ° C to -5 ° C. If it exceeds −5 ° C., it may be difficult to obtain indentation resistance. On the other hand, when the temperature is lower than −60 ° C., there is no significant problem in performance, but productivity may be reduced, such as appearance defects such as streaks are likely to occur during coating. A material having 4 or less reactive sites in one molecule is preferable, and the active reactive sites may be deactivated like an acrylic polymer. The following acrylic polymers, oligomers and monomers that are commercially available can be used in appropriate combination using the Tg upon curing as an index.

  Examples of materials that can be used as a flexible binder are given below. Mitsubishi Rayon Co., Ltd. (trade name “Diabeam” (registered trademark) series, etc.), Nippon Synthetic Chemical Industry Co., Ltd. (trade name “SHIKOH” (registered trademark) series, etc.), Nagase Sangyo Co., Ltd. (trade name “ (Denacol "(registered trademark) series, etc.), Shin-Nakamura Chemical Co., Ltd. (trade name" NK ester "series, etc.), DIC Corporation; (trade name" UNIDIC "(registered trademark), etc.), Toagosei Co., Ltd .; "Aronix" (registered trademark) series, etc.), NOF Corporation; ("Blemmer" (registered trademark) series, etc.), Nippon Kayaku Co., Ltd .; (trade name "KAYARAD" (registered trademark) series, etc.), Kyoeisha Chemical Co., Ltd. (trade name “Light Ester” series, etc.) can be mentioned, and these products can be used.

[Photopolymerization initiator]
As described above, it is preferable that at least one of the two or more coating compositions used in the production method of the present invention contains a photopolymerization initiator, and more preferably, two or more coating compositions. All of these preferably contain a photopolymerization initiator.

  As the photopolymerization initiator, various photopolymerization initiators, photoacid generators, and photobase generators that can be used can be used, but the coating composition is polymerized by radical polymerization reaction or the like. Those capable of initiating or promoting silanol condensation and / or crosslinking reaction are preferred.

  Examples of such photopolymerization initiators include, but are not limited to, alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, amine compounds, and the like.

  Of these, alkylphenone compounds are preferred because of their high curability. Specific examples of the alkylphenone compounds include 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1- ON, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one, 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4 -Yl-phenyl) -butan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butane, 2- (dimethylamino) -2-[(4-methylphenyl) ) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butane, α-hydroxyketone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl- -[4- (Methylthio) phenyl] -2-morpholinopropan-1-one, 2-methyl-1-phenylpropan-1-one, 1- [4- (2-ethoxy) -phenyl] -2-hydroxy 2-methyl-1-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 1,2-octane Examples include dione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], and acylphosphine oxide.

  Of the two or more types of coating compositions used in the production method of the present invention, at least one type preferably includes two or more types of photopolymerization initiators having different absorption wavelength ranges. More preferably, all of the two or more types of coating compositions contain two or more types of photopolymerization initiators having different absorption wavelength ranges. In the present invention, “different in the absorption wavelength region” means that the absorption maximum wavelength of the photopolymerization initiator differs by 5 nm or more. The absorption maximum wavelength is preferably different by 10 nm or more, and more preferably 50 nm or more. By containing two or more types of photopolymerization initiators having different absorption wavelength regions in the coating composition, in the step of irradiating the active energy ray (step 2), the coating film is not completely cured but is increased in viscosity. Furthermore, by irradiating energy rays in the curing step 4, the two-layer coating film can be easily cured, and the interlayer diffusion of the two-layer coating layer can be easily suppressed. The step of irradiating active energy rays (step 2) is performed before the drying step (step 3).

  It is preferable that at least one of the two or more coating compositions used in the method for producing a laminate of the present invention includes at least one photopolymerization initiator having an absorption maximum wavelength at a wavelength of 350 nm or more. It is more preferable that all of the two or more coating compositions contain at least one photopolymerization initiator having an absorption maximum wavelength at a wavelength of 350 nm or more. By irradiating the active energy whose median spectral distribution is 350 nm or more in Step 2 by irradiating at least one type of photopolymerization initiator with a photopolymerization initiator having an absorption maximum wavelength at 350 nm or more, Since thickening is likely to occur sufficiently and interlayer diffusion is less likely to occur in the drying process, functions required for the respective layers are easily exhibited.

  Examples of the photopolymerization initiator having an absorption maximum wavelength of 350 nm or more include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 2-hydroxy-2. -Methyl-1-phenyl-propan-1-one, benzophenone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy- 1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one, 2-di Tylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2 , 4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], α-hydroxyketone, acylphosphine oxide Etc.

  Of the two or more types of coating compositions used in the production method of the present invention, at least one type may be used in combination with the photopolymerization initiator, and a curing agent and a catalyst may be added. By using the curing agent and the catalyst together, the reaction between the inorganic particles, between the binder raw materials, and between the inorganic particles and the binder raw materials may be more easily promoted. Examples of the curing agent and catalyst include an acidic catalyst and a thermal polymerization initiator. Examples of the thermal polymerization initiator include peroxides and azo compounds. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, acetic acid and the like.

[solvent]
The coating composition A and the coating composition B preferably 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, and still more preferably 1 or more and 6 or less. Here, the “solvent” refers to a substance that is liquid at room temperature and normal pressure, and can be removed from the coating film by evaporating almost the whole amount in the drying step after coating.

  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.

[Other additives]
The coating composition A and the coating composition B preferably contain a polymerization initiator, a 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.

  In addition, a leveling agent, an ultraviolet absorber, a lubricant, an antistatic agent, etc. may be added to the coating composition A and the coating composition B 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.

[Application example]
The laminate of the present invention can be widely used for a member having a curved surface in order to achieve both excellent surface hardness and flexibility, for example, an electrical appliance, an automobile interior member, and a building member.

  Examples include plastic products such as glasses / sunglasses, cosmetic boxes, food containers, smartphone housings, touch panels, keyboards, home appliances such as remote controls for TVs and air conditioners, buildings, dashboards, car navigation systems, touch panels, and rooms. It can be suitably used for vehicle interior parts such as mirrors, and the surfaces of various printed materials.

  When the laminate of the present invention is used as a “cover film for display” that protects a display or a touch panel, it is possible to prevent the display surface from being scratched or cracked, and can be struck with a hard object such as a key or pebbles. It is particularly preferable because it can form a surface that is not easily deformed and can also be designed to have a curved surface.

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

<Preparation of coating composition>
The following materials were mixed to obtain coating compositions 1 to 8.

[Coating composition 1]
・ Binder raw material 1 42.5 parts by mass (“KAYARAD” DPHA-40H Nippon Kayaku Co., Ltd.)
・ Particulate material 1 25.0 parts by mass (alumina dispersion “NANOBYK-3602” manufactured by Big Chemie Japan Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 31.0 mass part.

[Coating composition 2]
・ Binder raw material 2 21.25 parts by mass (“New Frontier” TMP-3P, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
・ Binder raw material 3 21.25 parts by mass (“New Frontier” R1216, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
・ Particulate material 1 25.0 parts by mass (alumina dispersion “NANOBYK-3602” manufactured by Big Chemie Japan Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 31.0 mass part.

[Coating composition 3]
・ Binder raw material 4 50.0 parts by mass (“KAYARAD” UX-3204 Nippon Kayaku Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 48.5 mass parts.

[Coating composition 4]
・ Binder raw material 5 50.0 parts by mass (urethane acrylate EBECRYL270 manufactured by Daicel Ornex Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 48.5 mass parts.

[Coating composition 5]
・ Binder raw material 6 35.0 parts by mass (“New Frontier” RST-402, Daiichi Kogyo Seiyaku Co., Ltd.)
・ Particulate material 2 15.0 parts by mass ("Art Pearl" JB-800T Negami Industrial Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 48.5 mass parts.

[Coating composition 6]
・ Self-healing paint 7.1 parts by mass (“Folceed” NO.521C China Paint Co., Ltd.)
-92.86 mass parts of ethyl acetate.

[Coating composition 7]
・ 71.4 parts by weight of binder raw material 7 ("purple light" UV3520EA Nippon Synthetic Chemical Industry Co., Ltd.)
-Photo radical polymerization initiator 1.5 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).
-Methyl ethyl ketone 27.1 mass parts.

[Coating composition 8]
・ Binder raw material 8 100.0 parts by mass (acrylic polymer “8KX-078” Taisei Fine Chemical Co., Ltd.)
-Photoradical polymerization initiator 1.2 mass part ("Irgacure" (trademark) 184 BASF Japan Ltd.).

<Method for producing laminate>
23 μm thick “Lumirror” (registered trademark) U40 (manufactured by Toray Industries, Inc., hereinafter referred to as “Lumirror” (registered trademark) U40) is used as the substrate film A. And the following base film B was used. Table 1 shows the method for preparing the laminate, the coating composition to be used, and the film thickness of each layer corresponding to each example and comparative example. That is, each Example and Comparative Example manufactured the laminated body by the combination of the support base material shown in Table 1, the coating composition, the manufacturing method of a laminated body, etc. For example, in Example 1, the substrate film A is used as a supporting substrate, and the coating composition 3 is dried on one side of the substrate film A by the laminate production method A (sequential application) shown below. After coating with a wire bar to a thickness of 3 μm, drying and curing to form a layer, further coating, drying and curing to a thickness of 8 μm after drying using the coating composition 1 To form a surface layer. The surface layer was similarly formed about Examples 2-10 and Comparative Examples 1-4.

  On the other hand, in Example 11, the base film A was used as a support base, and the coating material was applied to one surface of the base film A from the support base A side by the production method B (simultaneous application) of the laminate shown below. In the production method B of the laminate shown below, the composition 3 and the coating composition 1 were simultaneously applied onto the supporting substrate A using a multilayer slot die so that the thickness after drying was 3 μm and 8 μm, respectively. The surface layer was formed on one surface of the supporting substrate A by drying under drying conditions. In Examples 12 and 13, the surface layer was formed by repeating the above simultaneous application twice.

(1) Base film B
Stirrer (the shape of the stirring blade is 1,000 L glass-lined reaction tank equipped with three retreating blades, 19.9 kg of diamine 1 and 3.85 kg of diamine 2 and anhydrous lithium bromide (Honjo Chemical Co., Ltd.) 7.0 kg and N-methyl-2-pyrrolidone (433 kg) were added, cooled to 0 ° C. in a nitrogen atmosphere, and acid dichloride 2 was added in 4.33 kg over 5 minutes with stirring over 90 minutes. After stirring for 1 minute, 12.46 kg of acid dichloride 1 was added in 10 portions, and after stirring for 1 hour, the hydrogen chloride generated in the reaction was neutralized with lithium carbonate to prepare a polymer solution having a polymer concentration of 7% by mass. Obtained.

  The obtained polymer solution was cast on an endless belt having a mirror-like surface so that the final film thickness was 23 μm using a die having a lip gap of 0.7 mm. Next, the cast polymer solution was heated with hot air at 130 ° C. for 6 minutes to evaporate the solvent, and peeled off from the endless belt while stretching 1.11 times in the longitudinal direction. Subsequently, it introduce | transduced into the water tank which 40 degreeC pure water flows, and desalted and desolvated. Furthermore, the film that came out of the water tank was introduced into a tenter, stretched 1.29 times at 260 ° C., then relaxed 0.98 times at 340 ° C., and further heat treated at the same temperature to obtain a base film B It was.

[Manufacturing Method A (Sequential Application) of Laminate]
Apply the coating composition on the support substrate using a wire bar, adjusting the count so that the thickness of the surface layer after drying will be the specified film thickness, then drying and curing processes under the following conditions went. By repeating these series of coating, drying and curing in sequence, a surface layer was formed on one surface of the support substrate.
"Drying process other than the outermost layer of sequential coating"
Air temperature and humidity: Temperature: 100 ° C
Wind speed: Application surface side: 5 m / sec, anti-application surface side: 5 m / sec Air direction: Application surface side / anti-application surface side: Vertical residence time with respect to the substrate surface: 2 minutes Curing process "
Integrated light quantity: 120 mJ / cm ²
Oxygen concentration: Atmospheric atmosphere.
"Drying process of outermost surface and single layer of sequential coating"
Air temperature and humidity: Temperature: 80 ° C
Wind speed: coating surface side: 5 m / sec, anti-coating surface side: 5 m / sec Wind direction: coating surface side: parallel to substrate surface, anti-coating surface side: vertical residence time to substrate surface: 3 Minute "Sequential coating outermost surface and single layer curing process"
Integrated light quantity: 120 mJ / cm ²
Oxygen concentration: 200 ppm or less.

[Lamination body production method B (simultaneous application)]
A multilayer body was manufactured by using the multilayer slot die 26 shown in FIG. 5 as the die 36 by the manufacturing process shown in FIG. First, the support base material is transported in the transport direction 44, and the coating composition shown in Table 1 is applied onto the support base material to form a coating film (Step 1) 40, upstream in the transport direction of the multilayer slot die. Coating composition B is applied from the slot on the side, and coating composition A is applied from the slot on the downstream side in the transport direction by adjusting the discharge flow rate so as to have the thickness of the coating layer necessary for forming the surface layer. A film was formed. Here, the thickness of the coating layer refers to the thickness of the layer of the coating composition applied on the support substrate.

  Subsequently, in the process (process 2) 41 which irradiates an active energy ray to a coating film, the active energy ray was irradiated using the active energy ray irradiation apparatus 40. FIG. Then, the coating film was dried using the drying furnace 41 in the process (process 3) 42 of drying a coating film. Finally, in the step of curing the coating film (step 4) 43, the active energy ray irradiation device 39 was used to cure the coating film to form a surface layer to obtain a laminate. Moreover, the following conditions were used for the process 2, the process 3, and the process 4.

[Step 2]
Active energy ray irradiation device: UV-LED
(CCS model: HLUV-126UV385)
(Median of integrated spectral distribution: 385 nm, full width at half maximum: 15 nm)
Irradiation intensity: 50 mW / cm ²
Irradiation time: 2 seconds [Step 3]
Drying furnace: Convective heat transfer (hot air)
Air temperature and humidity: Temperature: 100 ° C
Wind speed: coating surface side: 5 m / sec, anti-coating surface side: 5 m / sec Wind direction: coating surface side: parallel to substrate surface, anti-coating surface side: vertical residence time to substrate surface: 1 Minutes [Step 4 (when applying more)]
Curing method: Active energy ray irradiation Active energy ray irradiation device: High pressure mercury lamp irradiation intensity: 300 mW / cm ²
Integrated light quantity: 200 mJ / cm ²
Oxygen concentration: Air atmosphere [Step 4 (when located on the outermost surface)]
Curing method: Active energy ray irradiation Active energy ray irradiation device: High pressure mercury lamp irradiation intensity: 300 mW / cm ²
Integrated light quantity: 200 mJ / cm ²
Oxygen concentration: 200 ppm or less.

<Evaluation of laminate>
About the created laminated body, the performance evaluation shown next was implemented and the obtained result is shown to Tables 2-4. Unless otherwise specified, in each of the examples and comparative examples, the measurement was performed three times at different locations for each sample, and the average value was used.

[Measurement of total light transmittance and haze value]
The transparency of the laminate was determined by measuring the total light transmittance and haze value. The measurement is based on JIS-K7136 (2000), using a haze meter manufactured by Nippon Denshoku Industries Co., Ltd., so that light can be transmitted from the side opposite to the support substrate of the laminate sample (laminated film side). The measurement was performed. In addition, it measured in three different places of the same sample, and made the average value the total light transmittance and the haze value.

[Measurement of glass transition point of surface layer]
Measurement was performed using a differential scanning calorimeter DSCII type manufactured by Seiko Instrument Co., Ltd. The surface layer was cut out from the laminate with a cutter knife. When the surface layer is a thin film, the surface layer of the laminate can be scraped off with a scissors or a cutter knife, and the resulting sample can be analyzed. In order to sample the surface layer without excess or deficiency, after measuring the thickness of each layer with an atomic force microscope described later, it is necessary to scrape to a predetermined thickness. 5 mg of the surface layer sample thus prepared was held at −70 ° C. for 5 minutes in a nitrogen atmosphere and then 20 ° C./min. It measured with the temperature increase rate of. From this DSC curve, indium was used as a standard, and the glass transition point (Tg) was determined.

[Measurement of elastic modulus by atomic force microscope]
The laminates of Examples 1 to 13 and Comparative Examples 1 to 4 were embedded and cured with an electron microscope epoxy resin (Quetol 812 manufactured by Nissin EM Co., Ltd.), then a cross section was cut out by a freezing microtome method, and the cross section was measured. And fixed to a dedicated sample fixing base. Using an AFM “MFP-3DSA-J” manufactured by Asylum Technology and a cantilever “R150-NCL-10 (material Si, spring constant 48 N / m, radius of curvature of the tip 150 nm) manufactured by NANOSENSORS” The surface image was measured on the cross section in the taping mode and the resolution of 512 × 512 pixels.

  Subsequently, the magnification was adjusted from the obtained surface image so that the thickness of the surface layer was within the viewing angle. At this time, the interface between the surface layer and the supporting substrate is observed as a bright line or a dark line due to a mismatch in elastic modulus at the boundary between the surface layer and the supporting substrate, and the center of this bright line or dark line is a measurement standard in the thickness direction of the surface layer. A line. Similarly, for the outermost surface, the center of the bright line or dark line generated by the mismatch in elastic modulus between the surface layer and the embedding resin was used as a measurement reference line in the thickness direction of the surface layer. In the following measurement, the “distance in the thickness direction from the outermost surface” refers to the distance from the center of the bright line or dark line on the outermost surface. Similarly, the “distance in the thickness direction from the interface between the surface layer and the supporting substrate” refers to the distance from the center of the bright line or dark line at the aforementioned interface. The distance between the aforementioned surface layer-supporting substrate interface and the outermost surface was taken as the total thickness of the surface layer.

  Subsequently, a force curve (cantilever moving speed: 2 μm / s, maximum indentation load: 2 μN) was measured in contact mode at lattice point-like measurement points with a resolution of 512 × 512. From the Force-Ind curve obtained from the force curve, the software “IgorPro 6.22A MFP3D101010 + 1313” attached to the AFM apparatus was analyzed based on the Hertz theory attached to obtain the elastic modulus distribution. Note that Tip Geometry = Sphere, Radius = 150 nm, Select = Fused Silica, νTip = 0.17, Etip = 74.9 GPa, νSample = 0.33, Force tab Low = 10%, Force tab High = 90% Calculated.

[Measurement of average elastic modulus in surface layer]
Domain data belonging to the surface layer was extracted from the lattice point-like measurement points having a resolution of 512 × 512. Specifically, the distance in the thickness direction from the surface layer / support base material interface is less than 100 nm (reference numeral 9 in FIG. 2), and the distance in the thickness direction from the outermost surface is less than 100 nm (FIG. 2). The elastic modulus calculated from the data belonging to the inner belt-like domain was integrated, and the arithmetic average was taken as the average value of the elastic modulus in the surface layer.

[Measurement of elastic modulus distribution in thickness direction]
A data group on a straight line that cuts through the surface layer was selected from the lattice point-like measurement points having a resolution of 512 × 512. Furthermore, the distance in the thickness direction from the interface between the surface layer and the supporting substrate at each data point is calculated from the angle formed by the straight line that cuts through the surface layer to which the data group belongs and the normal line of the laminate, and the distance in the thickness direction is calculated. The elastic modulus distribution in the thickness direction was obtained by measuring the elastic modulus by the above-described method so as to be approximately 100 nm. At this time, the point in the thickness direction from the surface layer-supporting substrate interface is less than 100 nm (symbol 9 in FIG. 2), and the point in the thickness direction from the outermost surface is less than 100 nm (symbol in FIG. 2). 10) was excluded from the measurement because it was easily affected by the interface and surface. When the measurement is performed by the above method, the lower limit of the distance between the measurement points that can be set practically is determined from the thickness of the surface layer and the resolution. Specifically, it is about 1/500 of the thickness of the surface layer. For example, if the thickness of the surface layer is 50 μm, the spatial resolution is about 100 nm. Although it is possible to further increase the resolution in setting the apparatus, the above-mentioned value of about 100 nm is a practically measurable value from the curvature of the cantilever, the number of measurement points, and the like.

[Calculation of parameters from elastic modulus distribution in the thickness direction]
Based on the elastic modulus distribution in the thickness direction obtained by the method described above, the integrated thickness (Ta) of the portion where the elastic modulus is higher than the average value, and the integrated thickness (Tb) of the portion where the elastic modulus is lower than the average value, respectively. The following method was carried out.

  First, a portion where the elastic modulus is higher than the average and a portion where the elastic modulus is lower than the average are calculated from the elastic modulus distribution in the thickness direction and the average value of the elastic modulus in the surface layer. The concept is shown in FIG. 3, specifically, the coordinates of the intersection of the “average value of the elastic modulus in the surface layer” and the “elastic modulus distribution in the thickness direction” were calculated by the following method.

  As described above, since the “elastic modulus distribution in the thickness direction” is a set of discrete data points at intervals of about 100 nm, “one elastic modulus is lower than average and the other elastic modulus is higher than average”. Two adjacent points satisfying the condition were extracted, and the coordinates of the intersection of the straight line connecting the two points satisfying the condition and the straight line indicating the average value of the elastic modulus in the surface layer (hereinafter simply referred to as the coordinates of the intersection) were calculated. Then, the distance in the thickness direction between the intersections was calculated from the calculated coordinates of the intersections, and “the thickness of the portion where the elastic modulus was higher than the average” and “the thickness of the portion where the elastic modulus was lower than the average” were obtained. The thickness on the interface side with the support substrate is the distance from the surface layer-support substrate interface (reference numeral 12 in FIG. 3) to the coordinate of the shortest intersection (reference numeral 15 in FIG. 3). The thickness of the portion higher than the elastic modulus of the supporting substrate ”. Further, the thickness on the outermost surface side is the distance from the outermost surface (reference numeral 11 in FIG. 3) to the shortest intersection (reference numeral 16 in FIG. 3) of “the portion where the elastic modulus is higher than the elastic modulus of the supporting substrate. "Thickness". Furthermore, the thickness of the portion where the calculated elastic modulus is higher than the average and the thickness of the portion where the elastic modulus is lower than the average are integrated, respectively, and the integrated thickness (Ta) and the elastic modulus of the portion where the elastic modulus is higher than the average are obtained. The integrated thickness (Tb) of the part lower than the average was calculated.

[Measurement of elastic modulus distribution in the direction parallel to the interface]
Select a data group on a straight line parallel to the interface between the surface layer and the support substrate from the lattice point-like measurement points with a resolution of 512 × 512 obtained by the above method, and calculate the horizontal distance of each data point. Then, the elastic modulus distribution in the direction parallel to the interface was obtained by measuring the elastic modulus by the above-described method so that the distance between the interface and the horizontal direction was approximately 100 nm and the total length was 50 μm. At this time, the point in the thickness direction from the surface layer-supporting substrate interface is less than 100 nm (symbol 9 in FIG. 2), and the point in the thickness direction from the outermost surface is less than 100 nm (symbol in FIG. 2). 10) was excluded from the measurement because it was easily affected by the interface and the surface, and the measurement was performed on three straight lines near the outermost surface, near the center of the surface layer, and near the supporting substrate. In addition, the lower limit of the distance between each measurement point which can be set practically is equivalent to the elastic modulus distribution in the thickness direction.

[Calculation of histogram]
The histogram was calculated from the elastic modulus distribution in the thickness direction and the elastic modulus distribution in the direction parallel to the interface obtained by the above method. At this time, the elastic modulus was divided every 5 MPa, and stratification was performed using the histogram function of Microsoft Excel 2010 based on this. Next, a cumulative frequency distribution is calculated for the obtained histogram, and the elastic modulus E30 and e30 having a cumulative frequency of 30% is used as the average value of the class values crossing the cumulative frequency of 30%, and the average of the class values crossing the cumulative frequency of 70%. As values, elastic moduli E70 and e70 having a cumulative frequency of 70% were calculated, respectively.

[Surface hardness measurement by pencil hardness test method of surface layer]
The prepared laminate was allowed to stand under normal conditions (24 ° C., relative humidity 65%) for 12 hours, and then in accordance with the scratch hardness (pencil method) described in JIS K 5600-5-4 (1999) in the same environment. The surface hardness of the layer was measured.

[Scratch resistance of surface layer]
The prepared laminate is allowed to stand under normal conditions (24 ° C., relative humidity 65%) for 12 hours, and then steel wool (# 0000) having a load of 1,000 g / cm ² is perpendicular to the surface having the surface layer. The approximate number of scratches visually observed when the length of 5 cm was reciprocated 10 times was described, and the following classification was performed.
5 points: 0 4 points: 1 or more, less than 5 3 points: 5 or more, less than 10 2 points: 10 or more, less than 20 1 point: 20 or more.

[Flexibility of laminate]
The prepared laminate is allowed to stand for 12 hours under normal conditions (24 ° C., relative humidity 65%), and then in the same environment, the bending resistance described in JIS K 5600-5-1 (1999) (cylindrical mandrel method) Evaluation was performed according to type 1 of While maintaining the bent state, it is left for 24 hours under conditions of 85 ° C. and 85% relative humidity, and further left under normal conditions (24 ° C., relative humidity 65%) for 1 hour, after which the laminate is removed and a judgment is made. It was. The mandrels having diameters of 2, 3, 4, and 5 mm were used, and classification was performed as follows according to the minimum diameter at which cracks and coating film peeling were not observed by visual judgment. In addition, the same evaluation was implemented on the conditions which fold so that the surface which has a surface layer may become inside (valley fold).
5 points: No crack or peeling at 2 mmφ 4 points: Cracking or peeling at 2 mmφ 3 points: No cracking or peeling at 3 mmφ 3 points: Cracking or peeling at 4 mmφ 2 points: No cracking or peeling at 4 mmφ 2 points: Cracking or peeling at 4 mmφ No crack or peeling at 5 mmφ 1 point: Cracking or peeling at 5 mmφ

[Curlability of laminate]
The prepared laminate was allowed to stand under normal conditions (24 ° C., relative humidity 65%) for 12 hours, then cut into a 10 cm square shape and left on a horizontal plane. Next, the distance between the four corner points of the laminate and the horizontal plane was measured, and classified into five levels based on the average of the numerical values.
5 points: less than 1 mm 4 points: 1 mm or more, less than 10 mm 3 points: 10 mm or more, less than 20 mm 2 points: 20 mm or more 1 point: cylindrical and cannot be measured.

[Adhesion of surface layer]
The prepared laminate was allowed to stand under normal conditions (24 ° C., relative humidity 65%) for 12 hours, and then 100 pieces of 1 mm ² crosscuts were placed on the surface having the surface layer, and “Cello tape” (registered) manufactured by Nichiban Co., Ltd. (Trademark) is affixed on it, reciprocated three times with a load of 19.6 N using a rubber roller, pressed, peeled off in the direction of 90 degrees, and evaluated in five stages based on the number of remaining conductive layers (5:96) -100, 4: 81-95, 3: 71-80, 2: 61-70, 1: 0-60).

[Indentation resistance of laminate]
The prepared laminate was allowed to stand under normal conditions (24 ° C., relative humidity 65%) for 12 hours, and then the surface having the surface layer was placed on the top and allowed to stand on a stainless steel plate. Subsequently, it pressurized using the durometer (type D) based on JISK6253 (2012), and hold | maintained for 1 minute. Thereafter, the surface of the film was observed and classified into the following four stages.
5 points: No traces remain on the laminate.
4 points: There is a light dent in the laminate, but I don't mind.
3 points: There is a light dent in the laminate, but it does not matter depending on the angle.
2 points: There is a dent in the laminate, which is visible regardless of the angle.
1 point: A strong dent is generated in the laminate, and scratches are generated in the surface layer or the supporting substrate.

  The laminate according to the present invention can also be used for imparting similar functions to the surfaces of plastic molded products, home appliances, buildings, vehicle interiors, and various printed materials.

DESCRIPTION OF SYMBOLS 1 Support base material 2 Surface layer 3 Laminate body 4 Outermost surface 5 of surface layer Measurement start point 6 of elastic modulus of outermost surface side Interface 7 of surface layer and support base material Measurement start point 8 of elastic modulus of interface side In surface layer Average value of elastic modulus 9 Area 10 where measurement is not performed due to the influence of the supporting base material Area 11 where measurement is not performed due to the influence of the surface 11 Position 12 on the outermost surface of the surface layer Position 13 at the interface between the surface layer and the supporting base Thickness 14 of the portion where the modulus distribution and the elastic modulus are higher than the elastic modulus of the supporting substrate 14 Elastic modulus distribution in the thickness direction and the thickness 15 of the portion where the elastic modulus is lower than the elastic modulus of the supporting substrate 15 Average elasticity of the surface layer The point 16 closest to the interface between the surface layer and the supporting substrate 16 The point closest to the outermost surface 17 among the points where the elastic modulus of the surface layer is equal to the average value Multilayer slide dies 18, 27 Slots 19 and 28 on the most upstream side The second slot from the upstream side G 20 Third slot 21 from the upstream side Slot 22 at the most downstream side Slide surface 23, 29 of the die Die 24, 30, 34 Upstream side 25, 31, 35 in the conveying direction of the supporting substrate The conveying direction of the supporting substrate Downstream side 26 Multi-layer slot dies 32, 33 Single-layer slot dies 36 Dies 37, 39 Active energy ray irradiation device 38 Drying furnace 40 A step of applying a coating on a supporting substrate to form a coating film (step 1)
41 Step of irradiating the coating film with active energy rays (Step 2)
42 Step of drying the coating film (Step 3)
43 Step of curing the coating film (Step 4)
44 Transport direction

Claims (5)

A laminate having a surface layer on a support substrate, wherein the laminate satisfies all of the following (A) to (C).
(A) The total light transmittance of the laminate is 85% or more. (B) The surface layer has at least two different glass transition points Tg1 and Tg2. Here, the glass transition point on the lowest temperature side is Tg1, (C) Tg1 ≦ −5 ° C. and 30 ° C. ≦ Tg2−Tg1 ≦ 130 ° C. In the elastic modulus distribution in the thickness direction in a cross section perpendicular to the support substrate of the surface layer, the elastic layer has a portion having a high elastic modulus and a low portion relative to the average value of the elastic modulus, and from the elastic modulus distribution in the thickness direction. The thickness of each estimated part satisfies the following (D), The laminated body of Claim 1 characterized by the above-mentioned.
(D) Satisfying 3 μm ≦ Ta ≦ 10 μm, 1 μm ≦ Tb ≦ 9 μm, and 1.0 ≦ Ta / Tb ≦ 10.0 Ta: Integrated thickness where the elastic modulus is higher than the average value Tb: Average elastic modulus Integrated thickness of lower part An elastic modulus E70 having a cumulative frequency of 70% and an elastic modulus E30 having a cumulative frequency of 30% in a histogram calculated from the elastic modulus distribution in the thickness direction in a cross section perpendicular to the supporting substrate of the surface layer, and the supporting base of the surface layer The cumulative frequency 70% elastic modulus e70 and the elastic frequency e30 of the cumulative frequency 30% in the histogram calculated from the elastic modulus distribution in the direction parallel to the interface in the cross section perpendicular to the material satisfy the following (E): The laminate according to claim 1 or 2.
(E) 100 <[E70 / E30] / [e70 / 30] A display cover film comprising the laminate according to claim 1. A process of forming two or more coating compositions on a supporting substrate by a die coating method to form a coating film having two or more coating layers (process 1), a process of irradiating the coating film with active energy rays The step (step 2), the step of drying the coating film (step 3), and the step of curing the coating film (step 4) are performed once in this order. The manufacturing method of the laminated body.