JP2022151490A - Resin film, laminate, laminate production method, electric circuit, healthcare sensor, wearable sensor and production method for resin film processed goods - Google Patents

Abstract

To provide: the resin film and laminate having both printing plate separability and adhesiveness with a printed layer while having high flexibility and restorability; laminate production method; electric circuit; healthcare sensor; wearable sensor; and production method for resin film processed goods.SOLUTION: The resin film satisfying all of the following conditions 1 to 3 is provided. Condition 1: the storage elastic modulus of the resin film at 25°C under the condition of frequency 1 Hz is 0.5 MPa or more and 50 MPa or less. Condition 2: the loss tangent of the film at 25°C is 0.5 or less. Condition 3: the flat part percentage in at least one surface of the film by a laser microscope is 70% or less.SELECTED DRAWING: Figure 1

Description

The present invention provides a resin film, a laminate, a method for producing a laminate, an electric circuit body, and a health product, which has high flexibility and resilience, and has both printing plate releasability during the printing process and adhesion to the printing layer. The present invention relates to care sensors, wearable sensors, and methods for manufacturing resin film processed products.

In recent years, with the development of the IoT society, the development of wearable sensors has been actively carried out. Wearable sensors are attached to a part of the body, such as the arm, leg, or head, to constantly monitor the dynamic movement of the entire body, microscopic pressure in the body, electrical signals, etc. It is being developed in a variety of fields, including industrial and medical applications, and is expected to fundamentally change our lives through the collection of vast amounts of data and the use of such data as alarms and advice.

Various resin films have been studied as substrates for these devices. However, conventional materials are films with rigid chemical bonds and strong crystallinity, such as polyimide, which can be freely bent but cannot be stretched. Therefore, as a base material, a material that can be easily stretched and instantly restored is desired.

A representative example of such a resin film having high flexibility and resilience is a polyurethane produced by reacting a polyether polyol (a) having a carbonate bond with an isocyanate compound (b) described in Patent Document 1. and the polyether polyol (a) has a hydroxyl value of 55 or less”. In addition, in Patent Document 2, "In addition to wearability and shape followability, a conductive film with a small change in electrical resistance during stretching" and Patent Document 3, "It has excellent stretchability and strength, In addition, a stretchable film that has excellent water repellency on the film surface and does not have a sticky surface has been proposed.

JP 2015-189886 A JP 2017-199654 A JP 2020-105485 A

In order to use it as a sensor, it is required to mount stretchable wiring and electrodes on the base material, and offset printing, gravure printing, screen printing, etc. are considered as mounting methods. . As the realization of sensors using materials that can be easily stretched and instantly restored is approaching, while ensuring the adhesion between the printed layer and the resin film, including wiring and electrodes, during the printing process, Recently, there has been a demand for improving productivity without causing printing defects such as sticking between a printing plate and a resin film.

The resin film used in the aforementioned wearable sensor has "flexibility" that allows it to be greatly stretched with a weak force, and it is almost completely restored at a temperature of 0 ° C or less and at a rapid cycle of more than 1 time per second. "Restorability" is required. Materials with high flexibility are basically characterized by high tackiness, but we found that there is a problem that printing defects such as sticking to the printing plate tend to occur if the tackiness is high during printing. As a method to achieve both "flexibility" and "printing plate releasability", there is a method of reducing the interfacial interaction between the printing plate and the resin film by making the surface of the resin film less polar. The interfacial interaction between the printed layer and the resin film is also reduced, and the adhesion is likely to be reduced. In other words, it is necessary for the resin film to satisfy all four items of "flexibility", "restoration", "printing plate release", and "printing layer adhesion" at a high level.

In response to the above demands, the present inventors confirmed the above-mentioned viewpoints, and found that the material proposed in Patent Document 1 has excellent "flexibility" and good "printing layer adhesion". However, "restorability" and "printing plate release" were insufficient.

The material proposed in Patent Document 2 is excellent in "printing plate releasability" and "printing layer adhesion", but insufficient in "flexibility" and "restoration".

Further, the material proposed in Patent Document 3 is excellent in "flexibility", "restoration", and "printing plate separation", but is insufficient in "printing layer adhesion". In addition, when the uneven shape described in Patent Document 3 is added to the material described in Patent Document 1, improvement in "printing plate releasability" can be seen compared to Patent Document 1, but it is insufficient. In addition, although an improvement in "printing layer adhesion" was observed compared to that of Patent Document 3, it was insufficient.

From the above points, the problem of the present invention is to produce a resin film, a laminate, and a laminate that have both high flexibility and resilience, and are compatible with printing plate release during the printing process and adhesion with the printing layer. An object of the present invention is to provide a method for manufacturing an electric circuit body, a healthcare sensor, a wearable sensor, and a resin film processed product.

In order to solve the above problems, the present inventors completed the following invention as a result of earnest research. That is, a preferred embodiment of the resin film, the laminate, the method for producing the laminate, the electric circuit body, the healthcare sensor, the wearable sensor, and the method for producing the resin film processed product of the present invention is as follows.
(1) A resin film that satisfies all of the following conditions 1 to 3.

Condition 1: The storage elastic modulus of the resin film at a temperature of 25° C. and a frequency of 1 Hz is 0.5 MPa or more and 50 MPa or less.

Condition 2: The loss tangent of the resin film at 25°C is 0.5 or less.

Condition 3: The ratio of flat portions on at least one surface of the resin film is 70% or less as measured by a laser microscope.
(2) The resin film according to (1), which satisfies condition 4 below.

Condition 4: The root-mean-square roughness Rq of at least one surface of the resin film is 400 nm or more.
(3) The resin film according to (1) or (2), which satisfies condition 5 below.

Condition 5: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to water, which is obtained by the dynamic contact angle expansion/shrinkage method.

Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle.
(4) The resin film according to any one of (1) to (3), which satisfies condition 6 below.

Condition 6: At least one surface of the resin film has an arithmetic mean roughness Ra of 430 nm or more.
(5) The resin film according to any one of (1) to (4), which satisfies condition 7 below.

Condition 7: The maximum height Rz on at least one surface of the resin film is 8 µm or more.
(6) The resin film according to any one of (1) to (5), which satisfies condition 8 below.

Condition 8: At least one surface of the resin film has a surface free energy of 30 mN/m or more.
(7) The resin film according to any one of (1) to (6), which satisfies condition 9 below.

Condition 9: At least one surface of the resin film has a surface area of 1.3 mm ² or more per 1 mm square of the resin film.
(8) The resin film according to any one of (1) to (7), which satisfies condition 10 below.

Condition 10: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to propylene glycol monomethyl ether acetate (PGMEA) obtained by the dynamic contact angle expansion/shrinkage method.

Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle.
(9) The resin film according to any one of (1) to (8), which satisfies condition 11 below.

Condition 11: The resin film has a haze of 30% or more and 70% or less.

R ¹ in Formula 1 represents hydrogen or a methyl group.
(11) The resin film according to any one of (1) to (10), which contains the segment of Chemical Formula 2 and further contains either the segment of Chemical Formula 3 or the segment of Chemical Formula 4.

p is an integer of 1 or more.

r is an integer of 1 or more.

s is an integer of 1 or more.
(12) containing at least one segment selected from the group consisting of the segment of chemical formula 5, the segment of chemical formula 6, the segment of chemical formula 7, the segment of chemical formula 8, and the hydrogenated segments thereof, (1) to (11) ) The resin film according to any one of ).

(13) The resin film according to any one of (1) to (12), which is a single layer.
(14) A laminate comprising a substrate on at least one of the resin films according to any one of (1) to (13).
(15) The method for producing a laminate according to (14), wherein steps 1, 2, 3 and 4 are performed in this order.
Step 1: A step of applying a coating composition containing a resin precursor containing a segment of chemical formula 9 and a solvent onto a substrate A that satisfies condition 12 to form a coating layer.
Condition 12: The flat portion ratio on at least one surface of the substrate A surface measured by a laser microscope is 70% or less.

Step 2: A step of removing the solvent from the coating layer.
Step 3: A step of irradiating an active energy ray to crosslink the resin precursor.
Step 4: A step of peeling off the base material A after attaching the base material B to the surface opposite to the base material A of the coating layer.
(16) An electric circuit body comprising the resin film according to any one of (1) to (13) and a conductor circuit formed on the resin film.
(17) A healthcare sensor comprising the resin film according to any one of (1) to (13) and a conductor circuit formed on the resin film.
(18) A wearable sensor comprising the resin film according to any one of (1) to (13) and a conductor circuit formed on the resin film.
(19) A method for producing a resin film processed product, comprising a step of processing the resin film according to any one of (1) to (13) by screen printing.

Resin films and laminates that have both high flexibility and resilience, release from the printing plate during the printing process, and adhesion to the printing layer, methods for manufacturing laminates, electrical circuits, healthcare sensors, and wearables. A method for manufacturing a sensor and a resin film processed product can be provided.

It is a sectional view showing an example of a layered product in the present invention. It is a sectional view showing an example of a layered product in the present invention. It is a sectional view showing an example of a layered product in the present invention. It is a sectional view showing an example of a layered product in the present invention. 1 is a plan view showing an example of a screen plate in the present invention; FIG. 1 is a plan view showing an example of a screen plate in the present invention; FIG. 1 is a plan view showing an example of an electric circuit body in the present invention; FIG. 1 is a plan view showing an example of an electric circuit body in the present invention; FIG.

The inventors consider the reason why it is difficult to solve the problems of the present invention with the prior art as follows.

First, the mechanism by which the resin film sticks to the printing plate will be considered. A highly flexible resin film, which is required for this application, easily follows the uneven shape of the printing plate, and interfacial interaction occurs between the resin film and the printing plate, resulting in "tackiness". In particular, a flat resin film is considered to have a large degree of tackiness because the entire surface follows the uneven shape of the printing plate. Therefore, a highly flexible and flat resin film tends to stick to the printing plate during the printing process.

As a method of suppressing sticking to the printing plate, there is a method of lowering the surface free energy of the resin film, such as using a silicone-based or olefin-based material. In this case, interfacial interaction with the printed layer is reduced, and "adhesion to the printed layer" may become a trade-off. There is also a method of lowering the tackiness by increasing the elastic modulus of the resin film, but in this case, the crosslink density of the resin film is increased, which may result in a trade-off in "flexibility". Therefore, with these countermeasures, it is considered difficult to satisfy all of "flexibility", "restorability", "printing plate separation" and "printing layer adhesion".

From the above point of view, the reasons why the materials described in the patent document could not satisfy the four items of "flexibility", "restoration", "printing plate release", and "printing layer adhesion" were examined in detail. do.

The material described in Patent Document 1 uses polyurethane, and the polyether polyol portion functions as a soft segment with flexibility, and the urethane portion functions as a hard segment with high cohesion, which form a microphase-separated structure. is doing. In order to impart flexibility, the cohesive force of the urethane portion, which is a hard segment, is lowered, and along with this, the restorability is lowered. In addition, this material has high flexibility and a flat shape on the entire surface. Therefore, it is presumed that the printing plate releasability of this material was insufficient because the entire surface follows the uneven shape of the printing plate. On the other hand, both the soft segment and the hard segment are formed of segments with relatively high polarity, and it is assumed that the adhesiveness to the printed layer is good.

The material described in Patent Document 2 is an epoxy material having a high elastic modulus, onto which a base material having a concavo-convex shape formed by plasma treatment is transferred. It is presumed that the high elastic modulus results in low tackiness and good printing plate releasability, but the high crosslink density results in insufficient flexibility.

The material described in Patent Document 3 is a material obtained by patterning an uneven shape on a silicone material. Since the surface free energy is low and the shape is given to the surface, when the resin film comes into contact with the printing plate, it has a part of the non-contact portion, which reduces the contact area. Therefore, it is considered that the printing plate releasability is good. On the one hand, this material has a low surface free energy, which reduces the interfacial interaction with the printed layer. Furthermore, this material includes a flat portion and has a sharp change in the height difference direction of the uneven shape. It is thought that a gradient of Therefore, it is presumed that the print layer adhesion became insufficient.

In addition, when the polyurethane described in Patent Document 1 is provided with an uneven shape as described in Patent Document 3, the contact area with the printing plate is reduced, so that the separation of the printing plate from the polyurethane described in Patent Document 1 is reduced. Although there is a convex portion, it is flat, and it is considered that this portion causes sticking to the printing plate, resulting in insufficient printing plate releasability. In addition, although the adhesion of the printed layer is improved compared to Patent Document 3 by increasing the polarity of the resin composition, this material includes a flat portion and changes sharply in the direction of the height difference of the uneven shape. It is presumed that the printing paste does not easily enter the recessed portions of the resin film during printing, and the printed layer has a slope in the recessed portions and the raised portions, resulting in insufficient adhesion to the printed layer.

On the other hand, as a method for solving the above-mentioned problems, the present inventors used a material with high flexibility and resilience and reduced the flat portion ratio of the surface, so that during the printing process The present inventors have succeeded in obtaining a resin film that has both printing plate releasability and adhesion to the printing layer, leading to the present invention. Furthermore, as an unexpected effect obtained by achieving both printing plate separation and adhesion with the printing layer, it is possible to suppress the resistance value change of the printing layer even if the expansion and contraction behavior is repeated, and it is possible to stably detect electrical signals. all right. The details of the present invention are described below.

A preferred embodiment of the laminate of the present invention is a resin film that satisfies all of the following conditions 1 to 3.

Condition 1: The storage elastic modulus of the resin film at a temperature of 25° C. and a frequency of 1 Hz is 0.5 MPa or more and 50 MPa or less.

Condition 2: The loss tangent of the resin film at 25°C is 0.5 or less.

Condition 3: The ratio of flat portions on at least one surface of the resin film is 70% or less as measured by a laser microscope.

By adopting the above-described mode, it is possible to achieve both the releasability of the printing plate during the printing process and the adhesion to the printing layer while maintaining high flexibility and restorability. Furthermore, it is possible to suppress a change in the resistance value of the printed layer during expansion and contraction.

(Conditions 1 and 2)
The resin film of the present invention preferably has a storage elastic modulus of 0.5 MPa or more and 50 MPa or less at a temperature of 25° C. and a frequency of 1 Hz. When the storage elastic modulus is 0.5 MPa or more, it is possible to prevent handling from becoming difficult due to excessive tackiness, and when it is 50 MPa or less, the resin film can be easily deformed. . From the same viewpoint, it is more preferably 1.0 MPa or more and 25 MPa or less, and further preferably 3.0 MPa or more and 10 MPa or less.

The resin film of the present invention preferably has a loss tangent of 0.5 or less at 25°C. By setting the loss tangent to 0.5 or less, sufficient restorability can be obtained when used as a resin film. From the same point of view, the loss tangent of the resin film at 25° C. is more preferably 0.2 or less, more preferably 0.05 or less.

The storage modulus and loss tangent refer to values measured by a DMA (dynamic viscoelasticity measurement) method, which will be described later.

In order to keep the storage modulus and loss tangent of the resin film within the above range, the polymer must have a soft segment with flexibility and a hard segment with high cohesive strength, and these segments must form a microphase-separated structure. In addition, this hard segment can reduce the contribution of physical crosslinks such as π-π interactions and hydrogen bonds to the minimum necessary while forming small and strong chemical crosslinks such as acrylic crosslinks at a low density. is important. In order for physical crosslinks such as π-π interactions and hydrogen bonds to function as hard segments, it is necessary to increase the volume of the hard segments. Along with this, the elastic modulus increases and the flexibility decreases. Therefore, it is necessary to form small, strong chemical crosslinks at a low density. As a specific method, one or more polymer polyols having an alkyl group or alkenyl group having 3 or more carbon atoms selected from polyester polyols, polyether polyols, polycarbonate polyols, and polyolefin diols are used. and, TDI (tolylene diisocyanate), MDI (4,4′-diphenylmethane diisocyanate), NDI (1,5-naphthalene diisocyanate), TODI (tolidine diisocyanate), XDI (xylylene diisocyanate), PPDI (paraphenylene diisocyanate), One or more bifunctional isocyanates selected from TMXDI (tetramethylxylylene diisocyanate), HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), H6XDI (hydrogenated xylylene diisocyanate), H12MDI (dicyclohexylmethane diisocyanate), and HEA (hydroxyethyl acrylate) and 4HBA (4-hydroxybutyl acrylate), and one or more acrylic raw materials selected from 4HBA (4-hydroxybutyl acrylate), charged at a molar ratio of 1: (1 to 2): (0.4 to 1.0). A method of reacting at a ratio and polymerizing with heat or an active energy ray can be preferably adopted. Here, regarding the charge molar ratio, when the charge amount of the high molecular polyol is 1, a low molecular weight of 500 g/mol or less such as 1,6-hexanediol, triethylene glycol, or 3-methyl-1,5-pentanediol is used. The charged amount of the molecular polyol is preferably 0.1 or less. Further, with regard to the charging molar ratio, the charging amount of the tri- or higher functional isocyanate is preferably 0.1 or less when the charging amount of the bifunctional isocyanate is 1. In addition, the content of ash contained in 100% by mass of the resin film is preferably 1% by mass or less. Here, ash refers to the component when heated at 500° C. for 1 hour under nitrogen.

In addition, in order for the resin film to have a desirable storage modulus and loss tangent, the content of the monomer unit derived from the bifunctional isocyanate is 1 to 2 mol when the content of the monomer unit derived from the polymer polyol is 1 mol. , the content of the monomer unit derived from the acrylic raw material is 0.4 to 1.0 mol, the content of the monomer unit derived from the low-molecular-weight polyol is 0.1 mol or less, and the monomer unit derived from the trifunctional or higher isocyanate The content is preferably 0.2 mol or less. The qualitative/quantitative determination of each monomer unit can be performed by combining nuclear magnetic resonance spectroscopy, GC-MS, size exclusion chromatography, and time-of-flight mass spectrometry after alkaline hydrolysis of the resin film.

(Condition 3)
The resin film of the present invention preferably satisfies Condition 3.

Condition 3: At least one surface of the resin film has a flat portion ratio of 70% or less as measured by a laser microscope.

Here, the flat portion ratio of the resin film surface is a parameter that indicates the frequency of the thickness height difference of 100 nm or less per 1 μm in the plane direction in the line roughness data obtained by observing the resin film with a laser microscope. That is, by decreasing this value, the height difference in the thickness of the resin film surface constantly changes, and the entire surface becomes matte. Therefore, the number of contact points with the printing plate during the printing process can be reduced, and the releasability of the printing plate can be improved. Even if there are partial projections, if the pitch is wide and the ratio of flat portions exceeds 70%, the influence of the large number of flat portions that are partially generated will be stronger, and the printing plate separation will be worse. Therefore, it is important that the flat portion ratio is 70% or less from the viewpoint of printing plate releasability. In addition, when the protrusions are small and the flat portion ratio exceeds 70%, the printing plate and the resin film end up in contact with the entire surface due to the flexibility of the printing plate, and the printing plate separation becomes poor. Therefore, it is important that the flat portion ratio is 70% or less from the viewpoint of printing plate release. Furthermore, by setting the flat portion ratio to 70% or less, the entire surface becomes matte, and the entire interface between the resin film and the printed layer exhibits an anchor effect, thereby enhancing adhesion to the printed layer. If a part of the resin film becomes matte, it is conceivable that the anchoring effect will be exerted only in a part of the film and the adhesion between the resin film and the printed layer will become non-uniform at the interface. In this case, the smooth portion where the adhesiveness between the resin film and the printed layer is weak triggers peeling, and the adhesiveness with the printed layer is weakened when the resin film as a whole is viewed. Therefore, reducing the flat portion ratio of the surface is a method for improving both the releasability of the printing plate and the adhesion to the printing layer. In particular, a material that satisfies conditions 1 and 2 and has both flexibility and restorability, and in order to provide printing plate release and printing layer adhesion, the flat area ratio shown above is 70. % or less. From the same point of view, the flat portion ratio of the resin film surface is more preferably 50% or less, further preferably 40% or less.

Also, the flat portion ratio is preferably 5% or more, more preferably 10% or more. By adopting the above aspect, when the resin film is stretched, it is possible to prevent the depressions on the surface from becoming a trigger for breakage, and the original stretchability of the resin film can be maintained.

The flat portion ratio of the resin film surface is calculated by the method described below. Specifically, using a laser microscope (VK9700 manufactured by Keyence), observation is performed with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm, and analysis software (VK viewer) is used at any point on the observation surface. Acquire line roughness data for 100 μm. The number of pixels per 1 μm is calculated from the XY calibration values (the distance in the XY direction for each pixel) of the obtained line roughness data. In the real cross-sectional profile (the height in the Z direction for each pixel), the difference in the real cross-sectional profile is obtained so that the height difference (a) in the Z direction per 1 μm is obtained. These operations are performed three times, a histogram is taken from the line roughness data acquired three times, and the frequency of 100 nm or less is calculated. In addition, the directions of the acquired line roughness data for three times are shifted by 120° from any one direction.

A specific method for satisfying the condition 3 is to use a base material in which particles are kneaded, a sandblasted base material, or a base material laminated with a coating layer containing particles for the base material in producing the resin film. and the details of these methods will be described later.

The resin film required for this application is a resin film that has flexibility and resilience, and at the same time has good adhesion to the printing layer and good releasability from the printing plate during the printing process. Conditions 1 and 2 are conditions relating to flexibility and resilience, respectively, and by satisfying these conditions, a high level of flexibility and resilience can be achieved. On the other hand, as described above, a highly flexible resin film has high tackiness, and tends to have high adhesion to the printing plate during the printing process. As a method for suppressing sticking to the printing plate, 1. Decrease in surface free energy;2. 2. Decrease in tackiness due to increase in elastic modulus; Matting of the surface can be considered. 1. In the method of (1), the interfacial interaction on the surface of the resin film is lowered, and the adhesion with the printed layer becomes a trade-off. 2. In the method of (1), flexibility becomes a trade-off because the crosslink density in the resin film increases. On the other hand, 3. Since the method does not change the interfacial interaction on the resin film surface or the crosslink density in the resin film, it maintains a high level of flexibility, resilience, and adhesion with the printing layer, while maintaining a high level of adhesion with the printing plate. It is a preferable method for suppressing the sticking property of. On the other hand, it is not enough to just give the surface a matte shape, and in the method of increasing the surface roughness and surface height by giving a pattern shape to the resin film surface as described in Patent Document 3, it is difficult to remove the printing plate. was insufficient. When the cause of this was investigated, it was found that these resin films had high surface roughness, but the pitch of the irregularities was large, and flat portions were present in the concave portions or convex portions. It was considered that this flat portion was in strong contact with the printing plate, and that the printing plate releasability was insufficient.

Therefore, in the present invention, by focusing on the flat portion ratio of the surface and setting this value to 70% or less, it has all the flexibility, restorability, printing plate release, and printing layer adhesion that could not be achieved in the past. became possible.
Furthermore, as a result of extensive studies by the present inventors, it was found that the printing plate releasability and printing layer adhesion affect the resistance value change of the printing layer during expansion and contraction. It is believed that the high printing plate releasability makes it difficult for the wiring of the printed layer to be blurred or uneven in thickness, and the wiring can be expanded and contracted uniformly when the resin film is stretched, suppressing disconnection of the wiring. In addition, due to the high adhesiveness of the printed layer, when the resin film is stretched and stretched, the resin film and the printed layer can be stretched uniformly without peeling, and it is thought that disconnection of wiring can be suppressed. Therefore, by setting the flat portion ratio of the surface to 70% or less as in the present invention, it is possible to have all of flexibility, restorability, printing plate release, and printing layer adhesion, and furthermore, during expansion and contraction It was found that the resistance value change of the printed layer can be suppressed.
(Condition 4)
The resin film of the present invention preferably satisfies Condition 4.

Condition 4: The root-mean-square roughness Rq of at least one surface of the resin film is 400 nm or more.

The root-mean-square roughness Rq corresponds to the standard deviation of the arithmetic mean roughness, and a large value indicates non-uniformity in the surface unevenness size. Therefore, by increasing this value, the number of contact points with the printing plate during the printing process can be reduced, and the printing plate release property can be further enhanced. In addition, the interface between the resin film and the printed layer can be increased, and the adhesion with the printed layer can be enhanced by the anchor effect. From the same point of view, the Rq of the resin film is more preferably 600 nm or more, more preferably 800 nm or more.

The Rq of the resin film is calculated by the method described below. Specifically, according to the measurement of the flat portion ratio, using a laser microscope (Keyence VK9700), observation was performed with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm, and analysis software (VK viewer) Surface roughness data for 100 μm×100 μm is obtained at any point on the observation surface. These operations are performed three times, and the Rq of the resin film is obtained by averaging the Rq values of each data.

A specific method for satisfying the condition 4 is to use a base material in which particles are kneaded, a sandblasted base material, or a base material laminated with a coating layer containing particles for the base material in producing the resin film. and the details of these methods will be described later.

(Condition 5)
The resin film of the present invention preferably satisfies Condition 5.

Condition 5: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to water, which is obtained by the dynamic contact angle expansion/shrinkage method.

Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle (θa) and the receding contact angle (θr) obtained by the expansion contraction method in the dynamic contact angle. In the case of the so-called “Wenzel mode”, in which the solid surface is mat-shaped and the droplet enters the recesses of the solid surface, the droplet senses the surface roughness of the mat-shaped surface, and when the droplet expands and contracts, the surface The roughness of the droplets acts as a resistance against the traveling direction of the droplets. Therefore, the greater the surface roughness of the mat shape, the greater the contact angle hysteresis. On the other hand, when the solid surface has a flat portion and the concave portion is deep, the liquid droplet does not enter the concave portion of the solid surface, and the concave portion has an air layer, which is a so-called “Cassie mode”. It is known that this "Cassie mode" is likely to occur especially when water with high surface tension is used. In this case, the droplet cannot be sensed on the uneven part of the surface, and the contact angle hysteresis is smaller than in the “Wenzel mode”. Therefore, by increasing the contact angle hysteresis, the droplets land on the solid surface in the "Wenzel mode", the number of contact points with the printing plate can be reduced, and the releasability of the printing plate can be improved. From the same point of view, it is more preferable that the contact angle hysteresis of the resin film to water is 8° or more.

As a specific method for satisfying condition 5, it is preferable to use a sandblasted substrate or a substrate laminated with a coating layer containing particles as the substrate for producing the resin film. , the details of these methods will be described later.

(Method for measuring dynamic contact angle)
The measurement of the dynamic contact angle is carried out after leaving the sample in an environment of 25° C. for 12 hours. Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. is used, and droplets are created under conditions that allow the creation of droplets that are as small as possible without creeping up the needle. The dynamic contact angle was measured by repeatedly injecting and sucking the liquid at a liquid ejection speed of 8.5 μL/s while the tip of the syringe needle was pointing after the droplet landed on the resin film surface. The shape is photographed continuously every 100 milliseconds and the respective contact angles are determined during the process. The contact angle of the droplet during the expansion/contraction process first changes as the droplet expands/contracts, and then exhibits a constant behavior. The contact angle during expansion is defined as the advancing contact angle, and the contact angle during contraction is defined as the receding contact angle. Here, when the contact angle is constant, the contact angle is arranged in the direction in which the droplet expands and contracts, and five consecutive points are selected in that order. ° or less.

(Condition 6)
The resin film of the present invention preferably satisfies Condition 6.

Condition 6: At least one surface of the resin film has an arithmetic mean roughness Ra of 430 nm or more.

By increasing the arithmetic mean roughness Ra, the number of contact points with the printing plate during the printing process can be reduced, and the releasability of the printing plate can be enhanced. Moreover, the interface between the resin film and the printed layer can be increased, and the anchor effect can increase the adhesion with the printed layer. From the same point of view, Ra of the resin film is more preferably 550 nm or more, more preferably 600 nm or more.

The Ra of the resin film is calculated by the method described below. Specifically, similarly to the above Rq, using a laser microscope (Keyence VK9700), observation was performed with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm, and analysis software (VK viewer) Surface roughness data for 100 μm×100 μm is acquired at an arbitrary point on the observed surface. These operations are performed three times, and the Ra of each data is averaged to obtain the Ra of the resin film.

As a specific method for satisfying condition 6, it is preferable to use a sandblasted substrate or a substrate laminated with a coating layer containing particles as the substrate for producing the resin film. , the details of these methods will be described later.

(Condition 7)
The resin film of the present invention preferably satisfies Condition 7.

Condition 7: The maximum height Rz on at least one surface of the resin film is 8 µm or more.

A large maximum height Rz means that the absolute value of the surface roughness is large, thereby reducing the contact points with the printing plate during the printing process and improving the printing plate release property. In addition, the interface between the resin film and the printed layer can be increased, and the adhesion with the printed layer can be enhanced by the anchor effect. From the same point of view, Rz of the resin film is preferably 9 μm or more, more preferably 10 μm or more.

The Rz of the resin film is calculated by the method described below. Specifically, similarly to the above Rq and Ra, a laser microscope (VK9700 manufactured by Keyence) is used to observe with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm, and analysis software (VK viewer) Surface roughness data for 100 μm×100 μm is obtained at any point on the observation surface. These operations are performed three times, and the Rz of each data is averaged to obtain the Rz of the resin film.

A specific method for satisfying condition 7 is to use a substrate that has been subjected to sandblasting so that Ra is 620 nm or more, or a coating that contains 20 parts by mass or more of particles of 5 μm or more for the substrate when producing the resin film. It is preferable to use a base material having laminated layers, and the details of these methods will be described later.

(Condition 8)
The resin film of the present invention preferably satisfies Condition 8.

Condition 8: At least one surface of the resin film has a surface free energy of 30 mN/m or more.

Here, the surface free energy of the resin film is obtained by determining the static contact angle of water, ethylene glycol, and diiodomethane with respect to the surface of the resin film at 25° C., the static contact angle of each liquid, and the following non- The dispersion term, polar term, and hydrogen bond term of the surface free energy of each liquid described in Patent Document 1 are introduced into the “Hata and Kitazaki extended Hawks equation” described in Non-Patent Document 2 below, and the simultaneous equations refers to the value obtained by solving Details of the measurement method will be described later.
Non-Patent Document 1: J.P. Panzer: J.P. Colloid Interface Sci. , 44, 142 (1973). .
Non-Patent Document 2: Yasuaki Kitazaki, Toshio Hata: Japan Adhesive Association Paper, 8, (3) 131 (1972). .

When the surface free energy of the resin film is 30 mN/m or more, the adhesion between the resin film and the printed layer can be made more sufficient, and a circuit pattern is formed on the resin film, and the resin film is repeatedly stretched. Occasionally, an increase in resistivity and a decrease in the signal-to-noise ratio of the signal obtained from the sensor can be mitigated. Furthermore, it is possible to suppress the occurrence of poor continuity due to breakage of the circuit pattern. From the same point of view, it is more preferable that the surface free energy of at least one surface of the resin film is 35 mN/m or more.

The surface free energy can be set within the above range by appropriately selecting a material including a resin film described later and a surface treatment method.

(Method for measuring static contact angle)
The static contact angle is measured after leaving the sample in an environment of 25° C. for 12 hours. Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. is used, and droplets are created under conditions that allow the creation of droplets that are as small as possible without creeping up the needle. The static contact angle is calculated using the θ/2 method using an image taken 5 seconds after the droplet is applied on the resin film surface.

(Condition 9)
The resin film of the present invention preferably satisfies Condition 9.

Condition 9: At least one surface of the resin film has a surface area of 1.3 mm ² or more per 1 mm square of the resin film.

Here, the surface area per 1 mm square is a value calculated based on line roughness data obtained by observing the resin film with a laser microscope. That is, by increasing this value, it is possible to increase the interface between the resin film and the printed layer, and to increase the adhesion to the printed layer due to the anchor effect. From the same point of view, the surface area per 1 mm square is more preferably 1.5 mm ² , more preferably 2.0 mm ² or more.

The surface area per 1 mm square resin film is calculated by the method described below. Specifically, similarly to the flat portion ratio of the surface described above, observation was performed using a laser microscope (Keyence VK9700) with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm. viewer) to obtain line roughness data for 100 μm at any point on the observation surface. The number of pixels per 1 μm is calculated from the XY calibration values (the distance in the XY direction for each pixel) of the obtained line roughness data. In the real cross-sectional profile (the height in the Z direction for each pixel), the difference in the real cross-sectional profile is obtained so that the height difference (a) in the Z direction per 1 μm is obtained. Subsequently, the surface length (L ₁ = (1+a) ^1/2 ) is calculated for each 1 μm, and after summing the actual cross-sectional profile data, the surface length (L ₂ ) is calculated for each 1 mm. Standardize. By squaring this value, the surface area per 1 mm square (S=(L ₂ ) ² ) is obtained.

As a specific method for satisfying condition 9, it is preferable to use a sandblasted substrate or a substrate laminated with a coating layer containing particles as the substrate for producing the resin film. , the details of these methods will be described later.

(Condition 10)
The resin film of the present invention preferably satisfies Condition 10.

Condition 10: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to propylene glycol monomethyl ether acetate (PGMEA) obtained by the dynamic contact angle expansion/shrinkage method.

Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle (θa) and the receding contact angle (θr) obtained by the expansion contraction method in the dynamic contact angle, as in Condition 5. Also, PGMEA is a general-purpose solvent contained in printing paste used during printing. That is, by increasing this value, droplets land on the solid surface in the "Wenzel mode", the number of contact points with the printing plate can be reduced, and the printing plate release property can be improved. Furthermore, the printing paste penetrates into the unevenness of the surface of the resin film during printing, and the printed layer after removing the solvent can enhance the adhesion to the resin film. From the same point of view, the contact angle hysteresis of the resin film to PGMEA is more preferably 8° or more.

A specific method for satisfying condition 10 is to use a substrate that has been sandblasted so that Ra is 620 nm or more, or a coating that contains 20 parts by mass or more of particles of 5 μm or more for the substrate when producing the resin film. It is preferable to use a base material having laminated layers, and the details of these methods will be described later.

(Condition 11)
The resin film of the present invention preferably satisfies Condition 11.

Condition 11: The haze of the resin film is 30% or more and 70% or less.

Here, the haze of the resin film is a parameter that indicates the cloudiness of the resin film and indicates the degree of diffusion of light. The haze can be increased by increasing the size of the unevenness on the surface. On the other hand, if this value is too large, the film becomes opaque, and the shapes, colors, marks, etc. of objects placed under the film become blurred, making it difficult to adjust the position when modularizing. From the same point of view, the haze of the resin film is more preferably 40% or more and 60% or less.

The haze of the resin film is measured three times with NDH-5000 (Nippon Denshoku) with the surface of the resin film having high surface roughness facing upward, and the haze is taken as the average value.

In particular, when a layer containing particles is laminated on a resin film, the difference in composition between the particles and the resin film tends to change the refractive index and increase the haze. Therefore, as a method that satisfies the condition 11, it is preferable to transfer a base material when producing a resin film instead of laminating a layer containing particles.

(Material, structure, bonding)
The resin film of the present invention contains one or more selected from acrylic resins, methacrylic resins, silicone resins, urethane resins, acrylic urethane resins, epoxy resins, and styrene resins. It is preferable from the viewpoint of obtaining the properties.

Among others, the resin film of the present invention preferably contains the structure of chemical formula 1 and urethane bonds.

R ¹ in Formula 1 represents hydrogen or a methyl group.

Whether the resin film contains the above structures and bonds can be examined by various analytical methods, but at least FT-ATR-IR (Fourier transform total reflection infrared spectrophotometry) or pyrolysis GC-MS (Gas chromatograph mass spectrometry) analysis method, or if it can be understood that the resin film contains the above structure or bond from the raw material forming the resin film, the resin film has the above structure or bond. shall include binding.

By having the above structure, the resin film can form a strong chemically crosslinked structure and impart strong restorability. In addition, by including a urethane bond, it is possible to impart resilience while maintaining flexibility by forming weak physical crosslinks by hydrogen bonding.

More preferably, the structure of Chemical Formula 1 includes the structure of Chemical Formula 10.

R ¹ in Chemical Formula 10 represents hydrogen or a methyl group.

R ² in Chemical Formula 10 refers to any of the following.
- a substituted or unsubstituted alkylene group,
- a substituted or unsubstituted arylene group,
- an alkylene group having an ether group, an ester group, or an amide group inside;
- an arylene group having an ether group, an ester group, or an amide group inside;
- an unsubstituted alkylene group having an ether group, an ester group, or an amide group inside;
- An unsubstituted arylene group having an ether group, an ester group, or an amide group inside.

The urethane-bonded segment preferably includes a structure represented by Chemical Formula 11.

In addition, R ³ in Chemical Formula 11 refers to any of the following.
- a substituted or unsubstituted alkylene group,
- A substituted or unsubstituted arylene group.

In addition, it is preferable that the resin film of the present invention contains 30% by mass or more of an acrylic urethane resin in 100% by mass from the viewpoint of obtaining a high level of flexibility and resilience.

The resin film of the present invention preferably contains the segment of Chemical Formula 2 and further contains either the segment of Chemical Formula 3 or the segment of Chemical Formula 4.

p is an integer of 1 or more.

r is an integer of 1 or more.

s is an integer of 1 or more.

Here, the segment of chemical formula 2 is preferable as the aforementioned urethane bond. The segment of Chemical Formula 3 and the segment of Chemical Formula 4 are preferred as polyol residues. By combining the segment of chemical formula 2 and the segment of chemical formula 3, or the combination of the segment of chemical formula 2 and the segment of chemical formula 4, the interaction between each segment can be within a preferable range, and physical effects such as hydrogen bonding Strong chemical crosslinks of acrylic crosslinks can be formed at a low density while suppressing the formation of crosslinks.

Further, the resin film of the present invention contains at least one segment selected from the group consisting of the segment represented by Chemical Formula 5, the segment represented by Chemical Formula 6, the segment represented by Chemical Formula 7, the segment represented by Chemical Formula 8, and hydrogenated segments thereof. is preferred. In the chemical formulas 5 to 8, optional substituents can be adopted for omitted substituents, but hydrogen atoms are preferable.

Here, the segment represented by Chemical Formula 5, the segment represented by Chemical Formula 6, the segment represented by Chemical Formula 7, the segment represented by Chemical Formula 8, and hydrogenated segments thereof are preferred as polyol residues. In particular, the hydrogenated segment of Chemical Formula 5 or the hydrogenated segment of Chemical Formula 6 is particularly preferred. By using the segment of chemical formula 5, the segment of chemical formula 6, the segment of chemical formula 7, the segment of chemical formula 8, and the hydrogenated segment thereof, the formation of physical crosslinks such as hydrogen bonds is further suppressed, and acrylic crosslinks are formed. Strong chemical crosslinks can be formed at low densities. Moreover, solvent resistance can be improved when the printing paste is applied to the resin film.

(Layer structure)
The resin film of the present invention preferably consists of a single layer. Here, "consisting of a single layer" means that no discontinuous interface is observed when the cross section is observed by a scanning electron microscope (SEM) method. A specific observation method is to use a microtome to obtain a cross section in the thickness direction of a resin film embedded in a UV curable resin, and a cross section obtained by cutting the resin film together with the embedded resin. A method of observing a test piece obtained by vapor-depositing platinum under the conditions of 30 mA × 20 seconds × 2 times using an auto fine coater, using a scanning electron microscope (SEM) at a magnification of 5000 and an acceleration voltage of 3 kV. is. A more detailed observation method will be described in detail in the measurement method in Examples.

(Laminate structure)
The laminate of the present invention is preferably a laminate containing a substrate on at least one of the resin films. An example is shown in FIG. Here, the substrate is an article on the surface of which the coating composition for forming a resin film can be spread. The reason why it is preferable to provide a substrate in the laminate of the present invention is to ensure transportability and workability during production and processing of the resin film.

Moreover, in the method for producing a resin film of the present invention, it is preferable to perform steps 1, 2, 3, and 4 in this order.
Step 1: A step of applying a coating composition containing a resin precursor containing a segment of chemical formula 9 and a solvent onto a substrate A that satisfies condition 12 to form a coating layer.
Condition 12: The flat portion ratio on at least one surface of the substrate A surface measured by a laser microscope is 70% or less.

^R4 refers to hydrogen or a methyl group.
R ⁵ is preferably any of the following.
- A substituted or unsubstituted alkylene group.
- A substituted or unsubstituted arylene group.
- An alkylene group having an ether group, an ester group, or an amide group inside.
- An arylene group having an ether group, an ester group, or an amide group inside.
- An unsubstituted alkylene group having an ether group, an ester group, or an amide group inside.
- An unsubstituted arylene group having an ether group, an ester group, or an amide group inside.
R ⁶ is preferably any of the following.
- A substituted or unsubstituted alkylene group.
- A substituted or unsubstituted arylene group.
Step 2: A step of removing the solvent from the coating layer.
Step 3: A step of irradiating an active energy ray to crosslink the resin precursor.
Step 4: A step of peeling off the base material A after attaching the base material B to the surface opposite to the base material A of the coating layer.

Examples of laminate structures are shown in FIGS. Here, the substrate A is a substrate for improving transportability, and may be a multilayer laminate including a release layer. By including the release layer, it becomes easy to peel the base material A from the resin film, and it becomes easy to transfer the shape of the base material A to the resin film. In addition, when the base material A is peeled off from the resin film, it is possible to suppress so-called separation, in which the base material B and the resin film are separated.

Further, the substrate B is a substrate for improving transportability and preventing damage after peeling of the substrate A, and may be a multilayer laminate including a release layer and an adhesive layer. By including the release layer, the substrate B can be easily peeled off from the resin film, and the resin film alone can be post-processed. In addition, by including the adhesive layer, the base material B strongly adheres to the resin film, and when the base material A is peeled off from the resin film, it is possible to suppress so-called separation, that is, peeling between the base material B and the resin film. can.

[Mode of the present invention]
Embodiments of the present invention will be specifically described below.

[Resin film]
The resin film of the present invention, in addition to flexibility, restorability, printing plate release property, and printing layer adhesion, which are the problems, has hiding property, glossiness, fingerprint resistance, moldability, design property, scratch resistance, It may have other functions such as antifouling properties, solvent resistance, antireflection, antistatic, conductivity, heat ray reflection, near-infrared absorption, electromagnetic wave shielding, anchoring, and easy adhesion. Layers may be formed to form a laminate. For example, an adhesive layer, an electronic circuit layer, a printed layer, an optical adjustment layer, and other functional layers may be provided.

The thickness of the resin film is not particularly limited, and is appropriately selected according to its use. The lower limit of the thickness of the resin film is affected by the elastic modulus of the resin film itself, the elongation at break, the peeling force and peeling angle between the substrate and the resin film, etc., so it cannot be determined unconditionally. When using the manufacturing method to achieve physical properties equivalent to those of general flexible materials, the lower limit is about several μm.

[Laminate]
Preferred embodiments of the laminate of the present invention are as described above, but the laminate preferably has a base material on at least one surface of the resin film exhibiting the physical properties described above. Or it may be any three-dimensional shape after being molded.

[Base material]
The substrate used in the laminate of the present invention may be either a thermoplastic resin or a thermosetting resin, may be a homoresin, may be a copolymer, or may be a blend of two or more. The resin that constitutes the base material is preferable as long as it has good moldability, and from this point of view, thermoplastic resins are more preferable.

Examples of thermoplastic resins suitable for the base material include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, and polyimide resins. , polyester resin, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene-hexafluoropropylene copolymer, Fluororesins such as vinylidene fluoride resins, acrylic resins, methacrylic resins, polyacetal resins, polyglycolic acid resins, polylactic acid resins, and the like can be used.

Examples of thermosetting resins suitable for the substrate include phenol resins, epoxy resins, urea resins, melamine resins, unsaturated polyester resins, polyurethane resins, polyimide resins, and silicone resins. The thermoplastic resin is preferably a resin having sufficient stretchability and followability. From the viewpoint of strength, heat resistance, and transparency, the thermoplastic resin is more preferably polyester resin, polycarbonate resin, acrylic resin, or methacrylic resin.

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

The substrate preferably has a matte surface over the entire surface and a flat portion ratio of 40% or less. Examples of the method for imparting a matte shape include addition of particles during preparation of the base material, sandblasting treatment after preparation of the base material, coating of the particle layer, and the like, and sandblasting and coating of the particle layer are particularly preferred.

In addition, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, refractive index A dopant or the like for adjustment may be added.

Furthermore, the base material may have either a single layer structure or a laminated structure.

In addition to the resin film of the present invention, functional layers such as an easy-adhesion layer, an antistatic layer, an undercoat layer, an ultraviolet absorption layer, and a release layer may be provided in advance on the surface of the base material. The laminate of the present invention preferably has a release layer in order to reduce the peeling force between the substrate and the resin film. Details of the release layer will be described later.

Various surface treatments may be applied to the surface of the substrate before forming the resin film. Examples of 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.

[Release layer]
In the laminate of the present invention, when the resin film alone is post-processed, it is preferable that the substrate has a release layer as described above. A substrate having a release layer is also called a release film. The release layer may be composed of a plurality of layers from the viewpoint of imparting adhesion, antistatic properties, solvent resistance, etc., and may be present on both sides of the substrate.

The thickness of the release layer is preferably 10 to 500 nm, more preferably 20 to 300 nm, from the viewpoint of in-plane uniformity, appearance quality, and peel strength of the release layer. In addition, "~" indicates above and below.

[Method for producing resin film]
In the method for producing a resin film of the present invention, a coating composition containing a resin precursor containing a segment of chemical formula 2 is applied onto a substrate A to form a coating layer (step 1), and then a solvent is removed from the coating layer. is removed and dried (step 2), irradiated with active energy rays to crosslink the resin precursor (step 3), and finally after attaching the base material B to the opposite side of the base material A, the base material A is Peeling off (step 4) is preferred.

The method of applying the coating composition onto the substrate A in step 1 is not particularly limited as long as the coating composition can be applied onto the substrate A to form an in-plane uniform coating layer. The coating method on the film can be appropriately selected from a dip coating method, a roller coating method, a wire bar coating method, a gravure coating method, a die coating method (US Pat. No. 2,681,294), and the like. Here, the coating layer refers to a "liquid layer" formed by a coating process.

The method of removing the solvent in step 2, that is, the drying method, is not particularly limited as long as the solvent can be removed from the coating layer formed on the substrate. Examples of the drying method include heat transfer drying (adhesion to a high-temperature object), convective heat transfer (hot air), radiant heat transfer (infrared rays), and others (microwaves, induction heating). In the manufacturing method of (1), a method using convective heat transfer or radiant heat transfer is preferable because it is necessary to precisely uniform the drying speed even in the width direction.

In the cross-linking method of step 3, after drying, the coating layer from which the solvent has been removed is irradiated with an active energy ray to cause a reaction, thereby cross-linking the coating film.

For cross-linking with active energy rays, electron beams (EB) and/or ultraviolet rays (UV) are preferred from the viewpoint of versatility. Further, the types of ultraviolet lamps used for irradiating ultraviolet rays include, for example, a discharge lamp method, a flash method, a laser method, an electrodeless lamp method, and the like. When ultraviolet curing is performed using a discharge lamp type high-pressure mercury lamp, the ultraviolet illuminance is preferably 100 to 3,000 (mW/cm ² ), more preferably 200 to 2,000 (mW/cm ² ), still more preferably. is preferably 300 to 1,500 ⁽ mW/cm ² ). It is preferable to irradiate ultraviolet rays under the condition of 2,000 (mJ/cm ² ), more preferably 300 to 1,500 (mJ/cm ² ). Here, the ultraviolet illuminance is the irradiation intensity received per unit area, and varies depending on the lamp output, the emission spectrum efficiency, the diameter of the light-emitting bulb, the design of the reflecting mirror, and the distance from the light source to the irradiated object. However, the illuminance does not change with the transport speed. Further, the cumulative amount of ultraviolet light is the irradiation energy received per unit area, and is the total amount of photons that reach the surface. The integrated amount of light is inversely proportional to the irradiation speed passing under the light source, and proportional to the number of times of irradiation and the number of lamp lights.

The base material B in step 4 is not particularly limited as long as it has a higher peel strength than the base material A. A multilayer laminate including a release layer and an adhesive layer may also be used. By including the release layer, the substrate B can be easily peeled off from the resin film, and the resin film alone can be post-processed. In addition, by including the adhesive layer, the base material B strongly adheres to the resin film, and when the base material A is peeled off from the resin film, it is possible to suppress so-called separation, that is, peeling between the base material B and the resin film. can.

[Resin precursor]
The resin precursor is not particularly limited as long as it is a compound having a site that can be crosslinked.
A resin precursor containing the structure of Formula 9 is preferred, and a resin precursor containing the structure of Formula 12 is more preferred.

^R4 and ^R7 refer to hydrogen or methyl groups.
R ⁵ , R ⁸ and R ¹⁰ are preferably any of the following, and n is preferably an integer of 3 or more.
- A substituted or unsubstituted alkylene group.
- A substituted or unsubstituted arylene group.
- An alkylene group having an ether group, an ester group, or an amide group inside.
- An arylene group having an ether group, an ester group, or an amide group inside.
- An unsubstituted alkylene group having an ether group, an ester group, or an amide group inside.
- An unsubstituted arylene group having an ether group, an ester group, or an amide group inside.
R ⁶ and R ⁹ are preferably any of the following.
- A substituted or unsubstituted alkylene group.
- A substituted or unsubstituted arylene group.

As described above, the structures of chemical formulas 9 and 12 have a (meth)acrylic group at the end indicated by X in the figure, and the (meth)acrylic group (X) at the end is a site that can be crosslinked corresponds to Furthermore, the (meth)acrylic group (X) is adjacent to the polyisocyanate residue indicated by Y in the figure. Furthermore, the segment of chemical formula 12 means that the other end of the polyisocyanate residue represented by Y and the polyol residue (Z) represented by Z in chemical formula 12 are adjacent.

Polyisocyanate residues (Y) of chemical formulas 9 and 12 are preferably TDI (tolylene diisocyanate), MDI (4,4′-diphenylmethane diisocyanate), NDI (1,5-naphthalene diisocyanate), TODI (tolidine diisocyanate) , XDI (xylylene diisocyanate), PPDI (paraphenylene diisocyanate), TMXDI (tetramethylxylylene diisocyanate), HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), H6XDI (hydrogenated xylylene diisocyanate), H12MDI (dicyclohexylmethane diisocyanate) and other polyisocyanate residues.

The polyol residue of Formula 12 is preferably a polyester polyol, a polyether polyol, a polycarbonate polyol, or a polyol containing one or more segments selected from the segments of Formulas 5 to 8 above.

[Paint composition]
The "coating composition" used in the method for producing the laminate of the present invention is not particularly limited as long as it can be applied uniformly on the substrate and can form a resin film exhibiting the characteristics of the present invention. It is preferable that the coating composition is suitable for the manufacturing method of the laminate. Specifically, it is preferable to add the resin precursor described above, a solvent described later, and other components to form a coating composition.

[solvent]
The coating composition used in the method for producing a laminate of the present invention may contain a solvent, and preferably contains a solvent in order to uniformly form a coating layer in the plane. The number of types of solvents is preferably 1 to 20, more preferably 1 to 10, still more preferably 1 to 6, and particularly preferably 1 to 4. As used herein, the term "solvent" refers to a substance that is liquid at normal temperature and normal pressure and that can be almost completely evaporated in the drying process described above.

Here, the type of solvent is determined by the molecular structure that constitutes the solvent. That is, even if the elemental composition is the same and the type and number of functional groups are the same, the bonding relationship is different (structural isomers). Those that do not overlap exactly (stereoisomers) are treated as different kinds of solvents. For example, 2-propanol and n-propanol are treated as different solvents.

[Other components in the coating composition]
The coating composition used in the method for producing a laminate of the present invention preferably contains an antioxidant, a polymerization initiator, a curing agent and a catalyst. Polymerization initiators and catalysts are used to promote cross-linking of the resin film. As the polymerization initiator, those capable of initiating or promoting the polymerization, condensation or crosslinking reaction of components contained in the coating composition by anionic, cationic or radical polymerization reactions are preferred.

Antioxidants are broadly classified into radical chain initiation inhibitors, radical scavengers, and peroxide decomposers according to their mechanism of action, and the effects of the present invention can be obtained in any of these for suppression of deterioration under high temperature conditions. However, a radical scavenger or a peroxide decomposer is more preferable, and a hindered phenol-based or semi-hindered phenol-based radical scavenger, or a phosphite-based or thioether-based peroxide decomposer is more preferable.

Various polymerization initiators, curing agents and catalysts can be used. The polymerization initiator, curing agent and catalyst may be used singly, or multiple polymerization initiators, curing agents and catalysts may be used simultaneously. Furthermore, an acidic catalyst or a thermal polymerization initiator may be used in combination. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, acetic acid, and the like. Examples of thermal polymerization initiators include peroxides and azo compounds. Examples of photopolymerization initiators include alkylphenone-based compounds, sulfur-containing compounds, acylphosphine oxide-based compounds, and amine-based compounds. Examples of cross-linking catalysts that promote the formation reaction of urethane bonds include dibutyltin dilaurate and dibutyltin diethylhexoate.

As the photopolymerization initiator, it is preferable to use an alkylphenone-based compound or an acylphosphine oxide-based compound from the viewpoint of curability. Furthermore, from the viewpoint of heat and humidity resistance, it is more preferable to use an alkylphenone-based compound into which a hydroxyethoxy group is introduced. Specific examples of alkylphenone-type compounds include 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-(4-methylthiophenyl)- 2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]- 1-(4-phenyl)-1-butane, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl ) methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexyl-phenylketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy )-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2-phenyl-2-oxoacetic acid)oxybisethylene, and high molecular weight products of these materials. . Specific examples of acylphosphine oxide-based compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and polymerizing these materials. The following are listed. These may be used alone or in combination of two or more.

In addition, a leveling agent, a lubricant, an antistatic agent, etc. may be added to the coating composition used for forming the resin film as long as the effects of the present invention are not impaired. This allows the resin film to contain leveling agents, lubricants, antistatic agents, and the like.

Examples of leveling agents include acrylic copolymers, silicone-based leveling agents, and fluorine-based leveling agents. Examples of antistatic agents include metal salts such as lithium, sodium, potassium, rubidium, cesium, magnesium and calcium salts.

[Example of use]
INDUSTRIAL APPLICABILITY The resin film of the present invention can be suitably used for applications requiring particularly high flexibility and stretchability, taking advantage of its excellent optical properties, flexibility, stretchability, transportability, and appearance quality.

Examples include glasses/sunglasses, cosmetic boxes, plastic molded products such as food containers, aquariums, showcases for exhibitions, etc., smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, and wearables. Devices, sensors, circuit materials, electrical and electronic applications, home appliances such as keyboards, TV/air conditioner remote controls, mirrors, window glass, buildings, dashboards, car navigation/touch panels, vehicle parts such as rearview mirrors and windows, etc. printed matter, medical film, sanitary material film, medical film, agricultural film, building material film, etc., can be suitably used for each surface material, internal material, constituent material, and manufacturing process material. The quality of these materials can be improved by using the resin film of the present invention. Moreover, since the resin film of the present invention is excellent in printing plate releasability and adhesion to the printing layer, it can be particularly preferably used for electronic device circuit board applications.

EXAMPLES Next, the present invention will be described based on Examples, but the present invention is not necessarily limited to these.

"Synthesis of Resin Precursor"
Raw materials used in the synthesis of the resin precursor are as follows.

"Diisocyanate"
・IPDI: isophorone diisocyanate ・HMDI: hexamethylene diisocyanate ・MDI: 4,4′-diphenylmethane diisocyanate “Polyol”
・ PBAA: Polybutylene adipate manufactured by Tosoh Corporation “Nipporan” (registered trademark) 3027 (weight average molecular weight 2500)
· PTMG: Polytetramethylene glycol PTMG2000 manufactured by Mitsubishi Chemical Corporation (weight average molecular weight 2000)
・ PEAA: Polyethylene glycol adipate Tosoh Corporation “Nipporan” (registered trademark) 4040 (weight average molecular weight 2000)
・ MPDAA: Poly (3-methylpentanediol adipate) Kuraray Co., Ltd. “Kuraray Polyol” (registered trademark) P-2010 (weight average molecular weight 2000)
・ PB: polybutadiene with hydroxyl groups introduced at both ends Nippon Soda Co., Ltd. G-3000 (weight average molecular weight 3000)
・ HPB: hydrogenated polybutadiene with hydroxyl groups introduced at both ends Nippon Soda Co., Ltd. GI-3000 (weight average molecular weight 3100)
"hydroxy acrylate"
- HEA: hydroxyethyl acrylate [resin precursor 1]
IPDI as a diisocyanate, PBAA as a polyol, and toluene were placed in a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet. At this time, the molar ratio of diisocyanate and polyol was adjusted to 0.43:0.29, and the solid content concentration was adjusted to 60% by mass. When the reaction is carried out at 90° C. and the residual isocyanate group is 100% by mass when unreacted, the temperature is lowered to 70° C. when the residual isocyanate group becomes 1.4% by mass by the reaction, and HEA is added as a hydroxyacrylate. rice field. At this time, the molar ratio of the unreacted diisocyanate, polyol and hydroxyacrylate was adjusted to 0.43:0.29:0.29. Assuming that the residual isocyanate group in the unreacted state is 100% by mass, when the residual isocyanate group reaches 0.3% by mass by the reaction, the heating is stopped to terminate the reaction, and toluene is added to adjust the solid content concentration to 60%. A toluene solution of Resin Precursor 1 was obtained by adjusting the content to % by mass.

[Resin precursors 2 to 12]
Toluene solutions of Resin Precursors 2 to 12 were obtained in the same manner as in Resin Precursor 1 except that the combination and molar ratio of diisocyanate and polyol were changed to those shown in Table 1.

[Photoinitiator]
The following materials were used as photoinitiators.
Photopolymerization initiator 1 "IRGACURE" (registered trademark) 184 (manufactured by BASF Japan Ltd.)
[Leveling agent]
The following materials were used as leveling agents 1-3.
Leveling agent 1 FT-650AC (manufactured by Neos Co., Ltd.): fluorine-based leveling agent 2 “BYK” (registered trademark)-394 (manufactured by BYK Chemie Japan Co., Ltd.): acrylic leveling agent 3 “BYK” (registered trademark)-UV -3500 (manufactured by Big Chemie Japan Co., Ltd.): Silicone [Preparation of coating compositions 1 to 13]
Resin precursor, photopolymerization initiator, and leveling agent were mixed so that each solid content was in the ratio shown in Table 2, diluted with methyl ethyl ketone, and resin film-forming coating composition 1 having a solid content concentration of 40% by mass. ~13 was obtained.

[Preparation of coating composition 14]
A bifunctional methacrylic-modified polyisoprene ("Kuraprene" (registered trademark) UC-102AM, weight average molecular weight 17,000, manufactured by Kuraray Co., Ltd.) having methacrylic groups attached to side chains was diluted with toluene to obtain a solid content concentration of 60 mass. % of resin precursor 14 in toluene was obtained.

[Preparation of coating composition 15]
74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 0.1 g of potassium siliconate were placed in a 300 mL separable flask equipped with a cooling tube and a stirring blade, which was replaced with argon gas, and the temperature was raised and stirred at 120° C. for 30 minutes. . After that, the temperature was raised to 155° C. and stirring was continued for 3 hours. After 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was further stirred at 155° C. for 4 hours.

Furthermore, after 4 hours, it was diluted with 250 mL of toluene and then washed with water three times. The washed organic layer was washed several times with 1.5 L of methanol for reprecipitation purification to separate the oligomer and polymer. The obtained polymer was dried under reduced pressure at 60° C. overnight to obtain vinyl group-containing linear organopolysiloxane A1.

In the step of synthesizing vinyl group-containing linear organopolysiloxane A1, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl Vinyl group-containing linear organopolysiloxane A2 was synthesized in the same manner as the synthesis process for vinyl group-containing linear organopolysiloxane A1, except that 0.86 g (2.5 mmol) of cyclotetrasiloxane was used. did.

A silicone rubber compound 1 was obtained by kneading the following materials in advance.
- Vinyl group-containing linear organopolysiloxane A1: 72 parts by mass.
- Vinyl group-containing linear organopolysiloxane A2: 18 parts by mass.
- Hexamethyldisilazane SIH6110.1 (manufactured by Gelest): 10 parts by mass.
- Divinyltetramethyldisilazane SID4612.0 (manufactured by Gelest): 0.5 parts by mass.
- Deionized water: 5.25 parts by mass.

Then, 25 parts by mass of silica particles "AEROSIL" (registered trademark) 300 (manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by mass of silicone rubber compound 1, and the temperature was set to 60 to 90°C under a nitrogen atmosphere for the coupling reaction. After a first step of kneading for 1 hour at a low temperature and a second step of kneading for 2 hours at 160 to 180 ° C. under a reduced pressure atmosphere to remove a by-product (ammonia), then cooling, 8 parts by mass of vinyl group-containing linear organopolysiloxane A1 and 2 parts by mass of vinyl group-containing linear organopolysiloxane A2 were added and kneaded for 20 minutes to obtain silicone rubber compound 2.

Subsequently, the material was diluted with the following materials and toluene to obtain a resin film-forming coating composition 15 having a solid content concentration of 30% by mass.
- Silicone rubber compound 2: 100 parts by mass.
- Organohydrogenpolysiloxane 88466 (manufactured by Momentive): 0.35 parts by mass.
- Platinum catalyst SIP6831.2 (manufactured by Gelest): 0.05 parts by mass.
- Reaction inhibitor (1-ethynyl-1-cyclohexanol): 0.1 part by mass.

[Paint composition for particle layer]
47 parts by mass of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation) in terms of solid content, and an isocyanate-based cross-linking agent ("Coronate" (registered trademark) manufactured by Nippon Polyurethane Industry Co., Ltd. 23 parts by mass of solid content conversion of beads (Fuji Silysia Chemical Co., Ltd. silica particles “Sylysia” (registered trademark) 740, average particle size 5 μm) of 30 mass parts of solid content conversion, acetic acid Prepared by dissolving or dispersing in ethyl.

[Original film]
The following materials were used as raw films 1 to 8.
Original film 1 Biaxially stretched PET film thickness 50 μm Ra 80 nm.
Raw film 2 Biaxially stretched PET film thickness 50 μm Ra 220 nm.
Raw film 3 Biaxially stretched PET film thickness 50 μm Ra 420 nm.
Original film 4 “Lumirror” (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was sandblasted so that Ra was 410 nm.
Raw film 5 "Lumirror" (registered trademark) T60 50 µm (manufactured by Toray Industries, Inc.) was sandblasted so that Ra was 550 nm.
Raw film 6 “Lumirror” (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was sandblasted so that Ra was 750 nm.
Original fabric film 7 “Lumirror” (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was coated with paint 1 described below so that the thickness after drying was 5 μm, and then dried at 100° C. for 30 seconds.
Raw film 8 “Lumirror” (registered trademark) T60 50 μm (manufactured by Toray Industries, Inc.) was coated with paint 2 described below so that the thickness after drying was 5 μm, and then dried at 100° C. for 30 seconds.

<Paint 1>
53 parts by mass of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation) in terms of solid content, an isocyanate cross-linking agent ("Coronate" (registered trademark) manufactured by Nippon Polyurethane Industry Co., Ltd. 27 parts by mass of solid content conversion of beads (Fuji Silysia Chemical Co., Ltd. silica particles ““Sylysia” (registered trademark) 740” average particle size 5 μm) of 20 mass parts of solid content conversion, acetic acid Prepared by dissolving or dispersing in ethyl.

<Paint 2>
40 parts by mass of an acrylic binder ("Acrydic" (registered trademark) A-187" manufactured by DIC Corporation) in terms of solid content, an isocyanate cross-linking agent ("Coronate" (registered trademark) manufactured by Nippon Polyurethane Industry Co., Ltd. 20 parts by mass of solid content conversion of beads (Fuji Silysia Chemical Co., Ltd. silica particles “Sylysia” (registered trademark) 740, average particle size 5 μm) of 40 mass parts of solid content conversion, acetic acid Prepared by dissolving or dispersing in ethyl.

[Release layer coating composition]
The following materials were mixed and diluted with a mixed solvent of methyl ethyl ketone/isopropyl alcohol (mixing ratio by mass: 50/50) to obtain a release layer coating composition having a solid concentration of 5% by mass.
・Side chain type carbinol-modified reactive silicone oil (X-22-4015 Shin-Etsu Chemical Co., Ltd. Solid content concentration: 100% by mass): 5 parts by mass ・Both end-type polyether-modified reactive silicone oil (X-22 -4952 Shin-Etsu Chemical Co., Ltd. Solid content concentration: 100% by mass): 5 parts by mass Acryl-modified alkyd resin solution (Haliftal KV-905 Harima Chemicals Co., Ltd. Solid content concentration 53% by mass): 100 parts by mass Isobutyl alcohol modification Melamine resin solution (“Melan” (registered trademark) 2650L, Hitachi Chemical Co., Ltd., solid content concentration 60% by mass): 20 parts by mass Para-toluenesulfonic acid: 5 parts by mass.
[Method for producing laminate and resin film]
[Formation of substrate with release layer]
Using a coating device having a small diameter gravure coater, the number of lines of the gravure roll and the peripheral speed of the gravure roll are adjusted so that the thickness of the release layer after drying the release layer coating composition on the raw film is about 200 nm. , The coating composition for the release layer was applied by adjusting the solid content concentration, and then held at a hot air temperature of 140 ° C. for 30 seconds to perform drying and cross-linking, to obtain substrates 1 to 8 with a release layer. . The raw film types used are as shown in Table 3.

[Method of Forming Laminate]
<Examples 1 to 9, 11 to 32, Comparative Examples 1 to 8>
A laminate and a resin film were produced by the following method.

(Step 1)
As the substrate A, the above-mentioned substrate with a release layer is used, and the above-mentioned coating composition for forming a resin film is applied on the release layer of the substrate with a release layer using a continuous coating device using a slot die coater. A coating layer was formed by adjusting the discharge flow rate and coating so that the thickness of the resin film after cross-linking was 50 μm.

(Step 2)
The coating layer formed in step 1 was dried under the following conditions to remove the solvent.

Air temperature: 50°C
Wind speed; Coated surface side: 5 m/sec, Anti-coated surface side: 5 m/sec Wind direction: Coated surface side: parallel to the substrate surface, anti-coated surface side: vertical to the substrate surface Residence time: 2 minutes.

(Step 3)
In step 2, the coating layer (uncrosslinked resin film) obtained by removing the solvent is irradiated with active energy rays under the following conditions to be crosslinked, and the base material A, the release layer and the resin film are formed. A laminate was obtained.

Irradiation light source: high pressure mercury lamp Irradiation output: 400 W/cm ²
Accumulated amount of light: 120 mJ/cm ²
Oxygen concentration: 0.1% by volume.

(Step 4)
On the surface of the coating layer obtained in step 3 opposite to the substrate A, the raw film 1 as the substrate B was laminated by roll-to-roll. Subsequently, the base material A was peeled off to obtain a laminate composed of the base material B and the resin film.

<Example 10>
A laminate and a resin film were produced by the following method.

(Step 1)
As the substrate A, the above-described substrate 1 with a release layer is used, and a continuous coating device with a slot die coater is used to apply the coating composition 2 onto the release layer of the substrate with a release layer, after crosslinking. A coating layer was formed by adjusting the discharge flow rate and coating so that the resin film had a thickness of 50 μm.

(Step 2)
The coating layer formed in step 1 was dried under the following conditions to remove the solvent.

Air temperature: 50°C
Wind speed; coated surface side: 5 m/sec, non-coated surface side: 5 m/sec Wind direction; coated surface side: parallel to the surface of the substrate, non-coated surface side: vertical to the surface of the substrate Dwell time: 2 minutes.

(Step 3)
In step 2, the coating layer (uncrosslinked resin film) obtained by removing the solvent is irradiated with active energy rays under the following conditions to be crosslinked, and the base material A, the release layer and the resin film are formed. A laminate was obtained.

Irradiation light source: high pressure mercury lamp Irradiation output: 400 W/cm ²
Accumulated amount of light: 120 mJ/cm ²
Oxygen concentration: 0.1% by volume.

(Step 4)
Using a continuous coating device using a slot die coater, the coating composition for particle layer described above was applied to the surface of the laminate on the resin layer side by adjusting the discharge flow rate so that the film thickness after drying was 2 μm. , formed a particle layer.

(Step 5)
The coating layer formed in step 1 was dried under the following conditions to remove the solvent and obtain a laminate comprising the substrate A, the resin film, and the particle layer.

Air temperature: 100°C
Wind speed; coated surface side: 5 m/sec, anti-coated surface side: 5 m/sec Wind direction; coated surface side: parallel to the substrate surface, anti-coated surface side: vertical to the substrate surface Dwell time: 30 seconds.

Laminates and resin films of Examples 1 to 32 and Comparative Examples 1 to 8 were prepared by the above method. The resin film-forming coating compositions, release layer-attached substrates, and particle layers corresponding to each example and comparative example are shown in Table 4.

[Evaluation of Resin Film]
The resin films were subjected to the following performance evaluations, and the obtained results are shown in the table.

A measurement sample of the resin film was obtained by peeling the substrate from the laminate. Unless otherwise specified, the measurement was performed three times for each sample in each example and comparative example at different locations, and the average value was used.

[Measurement of storage modulus and loss tangent of resin film]
A measurement sample was cut into a rectangle with a width of 10 mm and used as a test piece.

Based on the tensile vibration-nonresonance method of JIS K7244-4 (1999) (this is referred to as a dynamic viscoelasticity method), the temperature of the resin film is 25 ° C. using a dynamic viscoelasticity measuring device DMS6100 manufactured by Seiko Instruments Inc. The storage elastic modulus and loss tangent at a frequency of 1 Hz were determined.
Measurement mode: Distance between tensile chucks: 20mm
Width of test piece: 10 mm
Frequency: 1Hz
Strain amplitude: 10 μm
Minimum tension: 20mN
Force amplitude initial value: 40mN
Measurement temperature: from -100°C to 200°C Heating rate: 5°C/min.

[Static contact angle measurement]
The static contact angle was measured after the sample was left in an environment of 25°C for 12 hours in advance. Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. was used, and droplets were prepared under conditions that would allow droplets to be as small as possible without crawling up the needle. The static contact angle was calculated using the θ/2 method using an image taken 5 seconds after the droplet was applied on the resin film surface.

[Calculation of flat part ratio of resin film surface and base material]
The flat portion ratio of the resin film surface and the base material is observed using a laser microscope (Keyence VK9700) with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm. , line roughness data for 100 μm was acquired at an arbitrary point on the observed surface. The number of pixels per 1 μm was calculated from the XY calibration values (the distance in the XY direction for each pixel) of the obtained line roughness data. In the real cross-sectional profile (the height in the Z direction for each pixel), the difference in the real cross-sectional profile was obtained so that the height difference (a) in the Z direction per 1 μm. These operations were performed three times, and a histogram was taken from the data obtained three times, and the frequency of 100 nm or less was calculated.

[Calculation of surface area per 1 mm square of resin film]
Specifically, the surface area per 1 mm square of the resin film was measured using a laser microscope (VK9700 manufactured by Keyence Corporation) with a 50-fold objective lens, a light amount of 100%, and a Z measurement pitch of 0.5, similarly to the above-mentioned surface flat portion ratio. Observation was performed at 02 μm, and line roughness data for 100 μm was acquired at an arbitrary point on the observed surface on analysis software (VK viewer). The number of pixels per 1 μm was calculated from the XY calibration values (the distance in the XY direction for each pixel) of the obtained line roughness data. In the real cross-sectional profile (the height in the Z direction for each pixel), the difference in the real cross-sectional profile was obtained so that the height difference (a) in the Z direction per 1 μm. Subsequently, the surface length (L ₁ = (1+a) ^1/2 ) is calculated for each 1 μm, and after summing the actual cross-sectional profile data, the surface length (L ₂ ) is calculated for each 1 mm. standardized. By squaring this value, the surface area per 1 mm square (S=(L ₂ ) ² ) was obtained.

[Calculation of Ra, Rq, and Rz of Resin Film]
Specifically, Ra, Rq, and Rz of the resin film are observed using a laser microscope (Keyence VK9700) with a 50x objective lens, a light intensity of 100%, and a Z measurement pitch of 0.02 μm. A surface roughness data of 100 μm×100 μm was acquired at an arbitrary point on the observation surface on the viewer). These operations were performed three times, and the Ra, Rq, and Rz of the resin film were obtained by averaging the values of Ra, Rq, and Rz for each data.

[Method for measuring dynamic contact angle]
The measurement of the dynamic contact angle was carried out after leaving the sample in advance in an environment of 25°C for 12 hours. Distilled water manufactured by FUJIFILM Wako Pure Chemical Co., Ltd. and Wako first grade PGMEA manufactured by FUJIFILM Wako Pure Chemical Co., Ltd. were used as measurement solvents, and Drop Master DM-501 manufactured by Kyowa Interface Science Co., Ltd. was used for each measurement solvent. The droplets were prepared under the conditions under which the droplets could be made as small as possible without creeping up the needle. The dynamic contact angle was measured by repeatedly injecting and sucking the liquid at a liquid ejection speed of 8.5 μL/s while the tip of the syringe needle was pointing after the droplet landed on the resin film surface. The shape was continuously photographed every 100 milliseconds and the contact angle was determined for each process. The contact angle of the droplet during the expansion/contraction process first changes as the droplet expands/contracts, and then exhibits a constant behavior. The contact angle during expansion was defined as the advancing contact angle, and the contact angle during contraction was defined as the receding contact angle. Here, when the contact angle is constant, the contact angle is arranged in the direction in which the droplet expands and contracts, and five consecutive points are selected in that order. ° or less. The contact angle hysteresis was defined as the absolute value of the difference between the advancing contact angle and the receding contact angle.

[Observation of resin film thickness and number of layers]
Observation of the thickness and the number of layers of the resin film was performed by cross-sectional SEM observation of the film using SEM JSM-6700F manufactured by JEOL Ltd. The procedure for preparing a test piece for cross-sectional SEM observation was as follows.
1. The resin film was embedded with a UV curable resin.
2. The resin film was cut together with the embedded resin using a rotary microtome RMS manufactured by Nippon Microtome Co., Ltd. so that a cross section in the thickness direction of the resin film could be obtained.
3. Using an auto fine coater JFC-1600 manufactured by JEOL Ltd., platinum was vapor-deposited to a thickness of about 10 μm (conditions: 30 mA×20 seconds×twice) on the cross section of the cut sample to obtain a test piece.

The conditions for cross-sectional SEM observation were as follows.
・Measurement mode: LEI mode ・Magnification: 5000 times ・Acceleration voltage: 3 kV
- WD (sample distance): 8.0 mm.

The thickness of the resin film was calculated from the above vertical distance between the embedding resins in the obtained cross-sectional SEM image, and the arithmetic mean value was adopted. The number of layers of the resin film was calculated from the number of discontinuous interfaces in the vertical direction between the embedding resins in the cross-sectional SEM image.

[Method for measuring haze of resin film]
The haze of the resin film was measured three times with NDH-5000 (Nippon Denshoku) with the rough surface of the resin film facing upward, and the haze was taken as the average value.

[Evaluation of flexibility of resin film]
A rectangular test piece having a width of 10 mm and a length of 150 mm was cut out of the resin film. The direction of each 150 mm length was aligned with the longitudinal direction of the resin film. Using a tensile tester (“Tensilon” (registered trademark) UCT-100 manufactured by Orientec), a tensile test was performed at a measurement temperature of 23° C. with an initial tension chuck distance of 50 mm and a tensile speed of 300 mm/min.

The load b (N) applied to the sample when the chuck-to-chuck distance was a (mm) was read, and the amount of strain x (%) and the stress y (N/mm ² ) were calculated from the following equations. However, let the sample thickness before the test be k (mm).
Strain amount: x = ((a-50) / 50) x 100
Stress: y=b/(k×10).

When the longitudinal direction was unknown, samples were taken in an arbitrary direction, then rotated by 60 degrees and 120 degrees, and the average value of the measurement results of a total of three samples was used for evaluation.

[Evaluation of resilience of resin film]
A rectangular test piece having a width of 10 mm and a length of 150 mm was cut out of the resin film. The direction of each 150 mm length was aligned with the longitudinal direction of the resin film. Using a tensile tester (“Tensilon” (registered trademark) UCT-100 manufactured by Orientec) at a measurement temperature of 23° C., evaluation was performed under two conditions with different deformation rates in order to determine the superiority or inferiority of the resilience.

Condition A: Initial distance between chucks 50 mm, tensile speed 50 mm/min After stretching the sample to a strain amount of 100%, the tensile load on the sample is released, and the distance marked as the initial test length before measurement is measured to L mm. As such, the elastic recovery rate z ₁ (%) was calculated from the following formula.

Elastic recovery rate z ₁ = (1-(L-50)/100) x 100 (%).

Condition B: Initial distance between chucks 50 mm, tensile speed 300 mm/min After stretching the sample to 100% strain, release the tensile load on the sample and measure the distance marked as the initial test length before measurement. As Lmm, the elastic recovery rate z ₂ % was calculated from the following formula.

Elastic recovery rate z ₂ =(1−(L−50)/100)×100 (%).

[Screen printing of resin film]
Screen plate (100 × 100 SUS325-28-C NU-55 emulsion thickness 5 μm Nakanuma Art Screen Co., Ltd.) having a pattern shown in FIG. A printing paste (LS-453-6B manufactured by Asahi Kagaku Kenkyusho Co., Ltd.) was placed on the screen plate. Then, the resin film was fixed on the stage of the printing machine, and the printing operation was started. After that, it was dried at 80° C. for 30 minutes to form a printed layer having a pattern shown in FIG. 7 or 8 on the resin film.

[Evaluation of printing plate releasability of resin film]
After printing with the screen plate shown in FIG. 5, the presence or absence of sticking to the screen plate was visually confirmed, and evaluated according to the following three grades.
◯: No sticking between the printing plate and the resin film, and the resin film is placed on the stage of the printing machine after printing.
Δ: The printing plate/resin film is weakly adhered, but the printing plate/resin film is peeled off during printing operation, and the resin film is placed on the printing press stage after printing.
x: Strong adhesion between the printing plate and the resin film, and the resin film did not rest on the stage of the printing machine after printing.

[Evaluation of Print Layer Adhesion of Resin Film]
A solid pattern printed layer as shown in FIG. 7 was formed on the resin film by screen printing. The adhesion between the printed layer and the resin film was evaluated according to the adhesion (cross-cut method) described in JIS K5600-5-6 (1999).
[Measurement of resistance change rate]
The rate of change in resistance value was measured by measuring the resistance value with a digital multimeter while stretching the resin film on which the printed layer of the wiring pattern was formed with a tensile tester.
By screen printing, a printed layer of a wiring pattern having a linear portion of 1 mm width and 50 mm length between electrode portions was formed on the resin film as shown in FIG. A 20 mm wide×150 mm long test piece was cut from the center of the wiring pattern. The direction of each 150 mm length was aligned with the longitudinal direction of the resin film. A 30 mm square copper plate was brought into contact with the electrode portion of this test piece and fixed with a tape. This test piece and the copper plate were connected to a tensile tester (“Tensilon” (registered trademark) UCT-100 manufactured by Orientec). The chuck-to-chuck distance was set to 50 mm, and adjustments were made so that the chuck-to-chuck and linear portions were aligned. The copper plate was connected to a digital multimeter ("Digital Multimeter" 34465A manufactured by Keysight Technologies) via a clip. While recording the resistance value with a digital multimeter, the sample was stretched to a strain of 20% at a tensile speed of 100 mm/min, held for 10 seconds, restored to 0%, and held for 10 seconds, which was repeated 20 times. From the maximum resistance value P (Ω) in the 1st cycle and the maximum resistance value Q (Ω) in the 20th cycle at this time, the resistance value change rate Q/P was obtained.

When the longitudinal direction was unknown, samples were prepared in an arbitrary direction, and then samples were prepared by rotating them by 60 degrees and 120 degrees, and the average value of the measurement results of a total of 3 samples was used for evaluation.

Table 5 shows the evaluation results of conditions 1 to 11 described above, Table 6 shows the structures of chemical formulas 1 to 8 of the resin film, the presence/absence of urethane bonds, and the layer structure of the resin film, and Table 7 shows the resin film. The results of flexibility, restorability, releasability of printing plate, adhesion of printing layer, and rate of change in resistance value were summarized.

In Table 6, the meaning of "containing" in the column of the structure of chemical formula 1 means that each example etc. includes the structure of chemical formula 1, and the meaning of "not containing" is that each example etc. contains the structure of chemical formula 1 structure is not included. The same applies to chemical formulas 2 to 8 and urethane bonds.

1, 4, 7, 11, 21, 24: Laminates 2, 5, 8, 12, 22, 25: Resin films 6, 9: Base material A
3, 10, 13: Base material B
14, 17: Screen plate 15, 18: Emulsion 16: Mesh (solid pattern)
19: Mesh (wiring pattern electrode part)
20: Mesh (wiring pattern linear part)
23: Print layer (solid pattern)
26: Print layer (wiring pattern electrode portion)
27: Print layer (wiring pattern linear part)

INDUSTRIAL APPLICABILITY The resin film of the present invention can be suitably used for applications requiring particularly high flexibility and stretchability, taking advantage of its excellent optical properties, flexibility, stretchability, transportability, and appearance quality.

Examples include glasses/sunglasses, cosmetic boxes, plastic molded products such as food containers, aquariums, showcases for exhibitions, etc., smartphone housings, touch panels, color filters, flat panel displays, flexible displays, flexible devices, and wearables. Devices, sensors, circuit materials, electrical and electronic applications, home appliances such as keyboards, TV/air conditioner remote controls, mirrors, window glass, buildings, dashboards, car navigation/touch panels, vehicle parts such as rearview mirrors and windows, etc. printed matter, medical film, sanitary material film, medical film, agricultural film, building material film, etc., can be suitably used for each surface material, internal material, constituent material, and manufacturing process material.

Claims (19)

A resin film that satisfies all of the following conditions 1 to 3.
Condition 1: The storage elastic modulus of the resin film at a temperature of 25° C. and a frequency of 1 Hz is 0.5 MPa or more and 50 MPa or less.
Condition 2: The loss tangent of the resin film at 25°C is 0.5 or less.
Condition 3: The ratio of flat portions on at least one surface of the resin film is 70% or less as measured by a laser microscope. The resin film according to claim 1, which satisfies condition 4 below.
Condition 4: The root-mean-square roughness Rq of at least one surface of the resin film is 400 nm or more. The resin film according to claim 1 or 2, which satisfies condition 5 below.
Condition 5: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to water, which is obtained by the dynamic contact angle expansion/shrinkage method.
Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle. The resin film according to any one of claims 1 to 3, which satisfies condition 6 below.
Condition 6: At least one surface of the resin film has an arithmetic mean roughness Ra of 430 nm or more. The resin film according to any one of claims 1 to 4, which satisfies condition 7 below.
Condition 7: The maximum height Rz on at least one surface of the resin film is 8 µm or more. The resin film according to any one of claims 1 to 5, which satisfies condition 8 below.
Condition 8: At least one surface of the resin film has a surface free energy of 30 mN/m or more. The resin film according to any one of claims 1 to 6, which satisfies condition 9 below.
Condition 9: At least one surface of the resin film has a surface area of 1.3 mm ² or more per 1 mm square of the resin film. The resin film according to any one of claims 1 to 7, which satisfies condition 10 below.
Condition 10: At least one surface of the resin film has a contact angle hysteresis of 5° or more with respect to propylene glycol monomethyl ether acetate (PGMEA) obtained by the dynamic contact angle expansion/shrinkage method.
Here, the contact angle hysteresis refers to the absolute value of the difference between the advancing contact angle and the receding contact angle. The resin film according to any one of claims 1 to 8, which satisfies condition 11 below.
Condition 11: haze of resin film is 30% or more and 70% or less 10. The resin film according to any one of claims 1 to 9, comprising the structure of Chemical Formula 1 and urethane bonds.

R ¹ in Formula 1 represents hydrogen or a methyl group. 11. The resin film according to any one of claims 1 to 10, comprising a segment represented by Chemical Formula 2 and further comprising either a segment represented by Chemical Formula 3 or a segment represented by Chemical Formula 4.

p is an integer of 1 or more.
r is an integer of 1 or more.
s is an integer of 1 or more. Any one of claims 1 to 11, comprising at least one segment selected from the group consisting of the segment of chemical formula 5, the segment of chemical formula 6, the segment of chemical formula 7, the segment of chemical formula 8, and the hydrogenated segments thereof The described resin film.

The resin film according to any one of claims 1 to 12, which is a single layer. A laminate comprising a substrate on at least one of the resin films according to any one of claims 1 to 13. 15. The method for producing a laminate according to claim 14, wherein steps 1, 2, 3 and 4 are performed in this order.
Step 1: A step of applying a coating composition containing a resin precursor containing a segment of chemical formula 9 and a solvent onto a substrate A that satisfies condition 12 to form a coating layer.
Condition 12: The flat portion ratio on at least one surface of the substrate A surface measured by a laser microscope is 70% or less.

Step 2: A step of removing the solvent from the coating layer.
Step 3: A step of irradiating an active energy ray to crosslink the resin precursor.
Step 4: A step of peeling off the base material A after attaching the base material B to the surface opposite to the base material A of the coating layer. An electric circuit body comprising the resin film according to any one of claims 1 to 13 and a conductor circuit formed on the resin film. A healthcare sensor comprising the resin film according to any one of claims 1 to 13 and a conductor circuit formed on the resin film. A wearable sensor comprising the resin film according to any one of claims 1 to 13 and a conductor circuit formed on the resin film. A method for producing a resin film processed product, comprising a step of processing the resin film according to any one of claims 1 to 13 by screen printing.

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