JP7396152B2 - Method for forming patterned film, patterned film and article - Google Patents

Description

The present invention relates to a method for forming a patterned film, a patterned film, and an article.

Various methods have been reported for forming patterned films, including methods using irradiation with active energy rays such as ultraviolet rays and electron beams, and methods using self-organizing materials such as block copolymers.

JP2009-260330A Japanese Patent Application Publication No. 2016-197176

In order to open up unexplored technological fields, it is necessary to develop new patterned films with special structures, and new methods that can easily provide patterned films with arbitrary shapes, structures, or sizes with a high degree of freedom. It is desirable to develop a method for forming patterned films.

In view of these circumstances, the present invention provides a method for forming a pattern film that can easily produce a pattern film having a special structure, and a pattern film having a special structure. The purpose is to

According to the first aspect of the present invention, the base material includes dispersed particles containing a first liquid that hardens upon irradiation with active energy rays, and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays. forming a film consisting of an emulsion;
The film was irradiated with the active energy rays in a pattern at an integrated light intensity that exceeded the integrated light intensity that maximized the difference in height of the pattern between the irradiated area and the non-irradiated area of the active energy rays. hardening the first liquid present in the region;
removing at least a portion of the second liquid from the film after irradiation with the active energy ray;
A method for forming a patterned film is provided, which includes curing the uncured first liquid contained in the film from which at least a portion of the second liquid has been removed.

According to the second aspect of the present invention, the base material includes dispersed particles containing a first liquid that hardens upon irradiation with active energy rays, and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays. forming a film consisting of an emulsion;
The film was irradiated with the active energy rays in a pattern at an integrated light intensity that exceeded the integrated light intensity that maximized the difference in height of the pattern between the irradiated area and the non-irradiated area of the active energy rays. Curing the dispersed particles present in the region to form a granular layer consisting of a cured product of the dispersed particles;
After irradiation with the active energy rays, at least a portion of the second liquid is removed from the film, and at least a portion of the uncured first liquid is transferred from the region not irradiated with the active energy rays to the particles. moving to a layer;
A method for forming a patterned film is provided, which includes curing the uncured first liquid contained in the film from which at least a portion of the second liquid has been removed.

According to a third aspect of the present invention, there is provided a patterned film formed by the method for forming a patterned film according to the first or second aspect.

According to a fourth aspect of the present invention, there is provided an article that includes a patterned film formed by the method for forming a patterned film according to the first or second side, and a base material that supports the patterned film.

According to the present invention, it is possible to provide a method for forming a patterned film that can easily produce a patterned film that has a special structure, and a patterned film that has a special structure.

FIG. 1 is a cross-sectional view schematically showing an example of an article including a patterned film formed by the patterned film forming method according to the first embodiment. FIG. 3 is a cross-sectional view schematically showing another example of an article including a patterned film formed by the patterned film forming method according to the first embodiment. FIG. 2 is a cross-sectional view schematically showing an example of a state in which a film made of an emulsion is formed on a base material. FIG. 2 is a cross-sectional view schematically showing an example of a state in which dispersed particles existing in an ultraviolet irradiation area are cured by patterned ultraviolet irradiation, and a granular layer made of a cured product of the dispersed particles is formed. FIG. 3 is a cross-sectional view schematically showing an example of a state in which dispersed particles coalesce in a region not irradiated with ultraviolet rays by starting removal of the second liquid from the film. A cross-sectional view schematically showing an example of a state in which the coalescence of dispersed particles further progresses in a non-irradiated region of ultraviolet rays, and the coalescence of dispersed particles penetrates and diffuses into a granular layer made of a cured product of dispersed particles. . FIG. 3 is a cross-sectional view schematically showing an example of a state in which the removal of the second liquid has been completed and the coalescence of dispersed particles has completely moved to the granular layer. FIG. 3 is a cross-sectional view schematically showing an example of a state in which an uncured first liquid is cured by irradiating the entire surface with ultraviolet rays. 2 is a graph schematically showing the relationship between the integrated light amount of active energy rays and the pattern height difference between the active energy ray irradiation area and the non-irradiation area. A graph schematically showing the relationship between the integrated light amount of active energy rays and the inclination of a pattern side wall portion. Graph showing the particle size distribution of the first to third emulsions prepared in Examples. A cross-sectional profile (a) in the thickness direction of the line-and-space pattern film and a differential waveform peak (b) obtained by differentially processing the cross-sectional profile (a). 2 is a graph showing the relationship between the integrated light amount of active energy rays and the pattern height difference between the active energy ray irradiation area and the non-irradiation area. A graph showing the relationship between the integrated light amount of active energy rays and the slope of the pattern side wall portion. Optical micrographs of line-and-space pattern films formed using the first to third emulsions prepared in Examples and varying the cumulative light amount (exposure amount). 3 is a photograph showing, in chronological order, the occurrence of convection in a liquid film due to heat of polymerization of dispersed particles (emulsion droplets) containing a first liquid. FIG. 3 is a schematic diagram for explaining the mechanism of generation of convection in a liquid film due to heat of polymerization of dispersed particles (emulsion droplets) containing the first liquid.

Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are more specific implementations of any of the above aspects. Note that elements having the same or similar functions are given the same reference numerals, and redundant explanations will be omitted.

[First embodiment]
FIG. 1 is a cross-sectional view schematically showing an example of an article according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing another example of the article according to the embodiment of the present invention.

The article shown in FIGS. 1 and 2 includes a base material 1 and a patterned film 2. The article shown in FIGS.
The material and shape of the base material 1 are arbitrary. It is desirable that the base material 1 has a smooth surface. As the base material 1, for example, a film or a sheet can be used.

The pattern film 2 is supported by the base material 1. In the example shown in FIGS. 1 and 2, the pattern film 2 forms a line and space pattern. The pattern film 2 may form a pattern other than a line and space pattern.

The patterned film 2 may be formed, for example, by a patterned film forming method according to an embodiment of the present invention described below (hereinafter also referred to as "pattern forming method according to this embodiment" or simply "this embodiment"). I can do it. This method uses an emulsion as a composition for forming a patterned film, and uses a phase separation structure resulting from self-organization of the emulsion to form a patterned film. This method uses the ET method (patterning) or ET method.

In the ET method, an emulsion containing dispersed particles containing a first liquid that hardens upon irradiation with active energy rays and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays is used.

Although the details will be described later, the basic steps of the ET method include forming a film made of this emulsion, irradiating the film with active energy rays in a pattern, and removing the first curing the liquid; removing at least a portion of the second liquid from the film after irradiation with active energy rays; and curing uncured liquid contained in the film from which at least a portion of the second liquid has been removed. 1. Curing the liquid.

In other words, the basic steps of the ET method include forming a film made of the emulsion, irradiating the film with active energy rays in a pattern, and dispersing the dispersed particles present in the area irradiated with the active energy rays. curing to form a granular layer made of a cured product of the dispersed particles; removing at least a portion of the second liquid from the film after irradiation with active energy rays; and removing at least a portion of the uncured first liquid. from a region not irradiated with active energy rays to the granular layer, and curing the uncured first liquid contained in the film from which at least a portion of the second liquid has been removed.

The patterned film 2 shown in FIGS. 1 and 2 can be formed by adjusting the cumulative amount of active energy rays in the ET method described above. The pattern film 2 includes a cured product 21b1 of dispersed particles, which will be described later, and a polymerized phase 21b2, and the cured product 21b1 forms a granular layer 21b.

Further, the patterned film 2 includes a side wall 2c having an inclination in the non-irradiated region R _S of active energy rays. The cured product 21b1 of dispersed particles forming the inclination of the side wall 2c is a cured product of dispersed particles that has moved from the active energy ray irradiation region R _L to the non-irradiation region R _S. This movement of the cured product 21b1 is due to the flow within the film made of the emulsion (convection within the liquid film) caused by polymerization heat generated by irradiation with active energy rays, and the details will be described in detail.

In this way, the side wall 2c of the pattern film 2 is formed by depositing the cured material 21b1 of dispersed particles that has moved from the irradiated area _RL to the non-irradiated area _RS , and the deposited thickness of the cured material 21b1 is continuously increased. It has a varying slope. A patterned film having such a side wall 2c can be formed by adjusting the cumulative amount of active energy rays, as described above. That is, it can be formed by irradiating a film made of the emulsion with active energy rays in a pattern such that the cumulative amount of active energy rays (hereinafter also referred to as "exposure amount") exceeds a predetermined cumulative amount of light. can. Here, the predetermined cumulative light amount is the cumulative light amount (hereinafter also referred to as " _EM ") that exceeds the cumulative light amount at which the difference in height of the pattern between the active energy ray irradiation area and the non-irradiation area is maximum. , details will be described later.

The pattern film 2 in FIGS. 1 and 2 both has a side wall 2c in the non-irradiation region R _S in which the deposited thickness of the cured product 21b1 of dispersed particles changes continuously, and the slope thereof is as shown in FIG. The patterned film 2 of is more gentle than the patterned film 2 of FIG. This is due to the difference in the cumulative amount of active energy rays in the ET method. That is, when _{the cumulative amount of light used in the pattern film 2 of FIG. 1 is E 1 and the} cumulative amount of light used in the pattern film ₂ of _FIG . ₁ >E _M , E ₂ >E _M ), and the second integrated light amount E ₂ is larger than the first integrated light amount E ₁ (E ₁ <E ₂ ).

As described above, according to the pattern forming method according to the present embodiment, which will be described later, it is possible to obtain a patterned film in which the side walls 2c formed by depositing the cured material 21b1 have different inclinations simply by changing the integrated light amount of active energy rays. I can do it.

The pattern film 2 can be formed, for example, by a pattern forming method according to the present embodiment described below. First, the basic steps included in the ET method will be explained in the order of emulsion preparation, film formation, active energy ray irradiation, second liquid removal, and pattern fixation, with reference to FIGS. 3 to 8. explain.

<Preparation of emulsion>
First, an emulsion is prepared that includes dispersed particles containing a first liquid that hardens upon irradiation with active energy rays and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays.
The emulsion may be an oil-in-water (O/W) emulsion or a water-in-oil (W/O) emulsion.

The dispersed particles contain a first liquid that is cured by irradiation with active energy rays. Examples of active energy rays include visible light, ultraviolet rays, electron beams, and X-rays. As the first liquid, for example, an acrylic monomer or oligomer, a methacrylic monomer or oligomer, an epoxy monomer or oligomer, or a mixture containing one or more of these can be used. As the first liquid, it is preferable to use an acrylic monomer or oligomer or a methacrylic monomer or oligomer because of the advantages of a wide range of options and a high degree of freedom in adjusting physical properties. As the first liquid, for example, trimethylolpropane triacrylate or the like can be used. The proportion of the monomer and oligomer in the first liquid is, for example, 30 to 100% by mass.

Note that there are more types of lipophilic liquids than hydrophilic liquids that harden upon irradiation with active energy rays. Therefore, the O/W type emulsion has a higher degree of freedom in material selection than the W/O type emulsion.

The dispersion medium includes a second liquid that does not harden upon irradiation with active energy rays. If the first liquid is lipophilic, the second liquid can be a hydrophilic liquid, such as water, a lower alcohol such as methanol or ethanol, or a mixture thereof. On the other hand, if the first liquid is a hydrophilic liquid, the second liquid can be a lipophilic liquid, such as an isoparaffinic solvent or mineral spirit.

The size of the dispersed particles depends on the pattern size to be formed, but preferably has an average particle size of 0.5 μm to 0.5 mm. Here, the "average particle size" is a weight average diameter obtained by particle size distribution measurement according to a laser diffraction/scattering method. When the dispersed particles have the above size, the uncured first liquid can be efficiently penetrated into the gaps between the particles in a later step.

Further, the proportion of dispersed particles in the emulsion is preferably 25% by mass or more. When the dispersed particles occupy the above proportion in the emulsion, the temperature of the region irradiated with active energy rays is increased by effectively utilizing polymerization heat, thereby destabilizing the dispersion state of the dispersed particles containing the first liquid. At the same time, a cohesive layer can be formed. Further, the upper limit of the proportion of the dispersed particles in the emulsion is not particularly limited as long as the phase inversion of the emulsion does not occur. According to one example, this proportion is less than or equal to 70-80% by weight.

The first liquid may further contain a photopolymerization initiator. As the photopolymerization initiator, a known photopolymerization initiator such as an alkylphenone photopolymerization initiator can be used. Examples of the alkylphenone photopolymerization initiator include 1-hydroxycyclohexylphenyl ketone. The first liquid can contain a photopolymerization initiator in an amount of, for example, 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of monomers and oligomers.

If the emulsion is of the O/W type, for example, the dispersed particles may contain hydrohobe in addition to the first liquid. Hydrohobes include, for example, higher alcohols with low solubility in water such as cetyl alcohol, hexadecane, polymerizable monomers with relatively large molecular weight hydrocarbon chains such as lauryl methacrylate and stearyl methacrylate, hydrophobic dyes, polymethyl methacrylate, etc. Examples include polymers such as polystyrene. The hydrohobe serves to stabilize the emulsion. The hydrohobe can be included in an amount of, for example, 0.1 to 10 parts by mass per 100 parts by mass of the first liquid.

The dispersion medium may further contain a surfactant. As the surfactant, for example, those commercially available for use in emulsion polymerization can be used. As the surfactant, for example, a sulfosuccinate type surfactant such as dioctyl sodium sulfosuccinate can be used. The emulsion may contain a surfactant in an amount of, for example, 0.1 to 5.0% by weight, based on the total weight of the emulsion.

In the case of an O/W type emulsion, the dispersion medium generally contains a surfactant in order to ensure emulsification and stability of dispersed particles. Further, the O/W emulsion can also contain water-soluble polymers, cellulose nanofibers, etc. in the dispersion medium in order to improve the long-term storage stability of the emulsion. Furthermore, if necessary, the O/W emulsion can also contain a viscosity modifier and an antifoaming agent in the dispersion medium.

On the other hand, in the case of a W/O emulsion, in order to prepare a stable emulsion, the dispersion medium contains a nonionic surfactant and a polymeric dispersion stabilizer having an appropriate hydrophilic-lipophilic balance (HLB) value. be able to. If necessary, it is also effective for the W/O emulsion to contain an ionic surfactant in the dispersion medium.

The emulsion can be prepared by using known emulsification/dispersion techniques, such as a paint shaker, an ultrasonic homogenizer, a colloid mill, a homogenizer, and a membrane emulsification method.

<Film formation>
Next, a film made of the above emulsion is formed on the base material. Hereinafter, the "film made of emulsion" will also be referred to as a liquid film. Specifically, a liquid film can be formed on a base material by applying the above emulsion onto the base material. As the base material, any base material can be used, such as a film or a sheet.

The coating method is not particularly limited, but an appropriate coating method such as die coating, comma coating, or curtain coating can be selected depending on the thickness of the liquid film. The thickness of the liquid film can be, for example, 10 to 3000 μm. Further, when applying a small amount of emulsion to form a liquid film with a small area, a dispenser or the like may be used as necessary.

FIG. 3 schematically shows an example of a state in which a film made of an emulsion is formed on a base material. In FIG. 3, a film 2a made of an emulsion composed of dispersed particles 21a and a dispersion medium 22 is formed on a base material 1.

<Irradiation of active energy rays>
Next, the formed film is irradiated with active energy rays in a pattern.
As mentioned above, examples of active energy rays include ultraviolet rays, electron beams, and X-rays. Pattern irradiation can be performed, for example, by selectively irradiating active energy rays through a mask or by selectively irradiating laser beams.

By pattern irradiation of the active energy rays, the first liquid contained in the dispersed particles is cured by polymerization in the area irradiated with the active energy rays (hereinafter also simply referred to as "irradiation area"). Thereby, a granular layer consisting of a cured product of dispersed particles can be formed.

FIG. 4 schematically shows an example of a state in which the dispersed particles existing in the area irradiated with ultraviolet rays are cured by pattern irradiation of ultraviolet rays, and a granular layer consisting of a cured product of the dispersed particles is formed.

As shown in FIG. 4, in the area irradiated with ultraviolet rays, the first liquid contained in the dispersed particles 21a is cured by polymerization, and the dispersed particles 21a become a cured product 21b1 of dispersed particles. The cured particles 21b1 of dispersed particles are aggregated and stacked, and as a result, a granular layer 21b consisting of the cured particles 21b1 of dispersed particles is formed.

In the area irradiated with ultraviolet rays, the second liquid contained in the dispersion medium 22 does not harden, so the dispersion medium 22 exists in the granular layer 21b, specifically, in the gaps between the cured materials 21b1. On the other hand, in FIG. 4, the first liquid contained in the dispersed particles 21a remains uncured in the non-irradiated area (hereinafter also simply referred to as "non-irradiated area") where the ultraviolet rays were not irradiated.

Regarding the aggregation mechanism of the cured material 21b1 in the irradiation area, the present inventor considers the reason as follows.

By irradiating the active energy rays, the dispersed particles 21a polymerize and generate heat, thereby increasing the temperature of the irradiated area. Due to this temperature rise, the surfactant that had been adsorbed onto the surface of the dispersed particles 21a to stabilize the dispersion of the dispersed particles 21a is desorbed. As a result, the surface potential of the dispersed particles 21a in which polymerization has progressed decreases. As a result, the dispersion of the dispersed particles 21a or their cured product 21b1 becomes unstable, and aggregation of the particles is promoted. Furthermore, in the process of particles agglomerating and coming into contact with each other, polymerization crosslinking may occur between particles.

Further, this aggregation is completed before the surfactant, which has been desorbed due to the temperature increase due to the heat generated by polymerization, is re-adsorbed onto the particles. This allows the aggregated particles to maintain their aggregated state without being redispersed.

Aggregation of the cured product 21b1 in the irradiation area may be promoted by adding a crosslinking agent to the dispersion medium in advance. This facilitates formation of crosslinks between particles during irradiation with active energy rays, and as a result, aggregation of particles is promoted.

<Removal of second liquid>
After irradiation with the active energy rays, at least a portion of the second liquid is removed from the film. In this step, at least a portion of the second liquid may be removed, but all of the second liquid may be removed. Removal of the second liquid can be performed, for example, by drying the membrane. Drying is preferably performed until the amount of the second liquid becomes 30% by mass or less, more preferably 5% by mass or less of the amount of the second liquid immediately after forming the liquid film. Although the second liquid may be removed by leaving the membrane at room temperature, it is preferably carried out by heating and drying the membrane. Heat drying can be performed, for example, by heating the membrane at a temperature in the range of 40 to 100° C. for 0.1 to 1 hour. By removing the second liquid, at least a portion of the uncured first liquid can be moved from the area not irradiated with active energy rays to the granular layer made of the cured product of dispersed particles.

In this step, by removing the second liquid, at least a portion of the uncured first liquid is moved from the non-irradiated area to the granular layer made of the cured product of the dispersed particles. The movement of the uncured first liquid from the non-irradiated area to the granular layer may be performed so that all of it moves to the granular layer, or only a part of it may move to the granular layer. .

Note that in this method, there is no need to perform a development step, that is, removal of the uncured first liquid using a developer after irradiation with active energy rays.

5 to 7 schematically illustrate an example of a change in state of the membrane caused by removal of the second liquid. FIG. 5 schematically shows an example of a situation in which coalescence of dispersed particles has occurred in the non-irradiated region by initiating the removal of the second liquid from the membrane. FIG. 6 schematically shows an example of a state in which the coalescence of dispersed particles further progresses in the non-irradiated area, and the coalescence of dispersed particles penetrates into a granular layer consisting of a cured product of dispersed particles and diffuses. ing. FIG. 7 schematically shows an example of a state in which the removal of the second liquid has been completed and the aggregates of dispersed particles have completely moved into the granular layer.

When a part of the second liquid contained in the dispersion medium 22 is removed from the film 2a, as shown in FIG. In the non-irradiated region, as the second liquid decreases, the dispersed particles 21a coalesce to form a coalesced body 21a'. Then, as shown in FIG. 6, the uncured first liquid forming the combined body 21a' permeates into the gaps in the granular layer 21b and diffuses into the granular layer 21b. This penetration and diffusion is thought to proceed due to capillary force.

When the removal of the second liquid is completed, the movement of the uncured first liquid from the non-irradiated area to the granular layer 21b is completed. As a result, for example, the structure shown in FIG. 7 is obtained. Note that when the second liquid is completely removed from the membrane, the liquid remaining in the membrane is, for example, only the liquid constituting the dispersed particles 21a or their combined bodies 21a'.

As described above, the pattern made of the granular layer 21b includes a plurality of portions having different pattern densities, similar to the patterned film 2 finally obtained. As explained below, the amount of the first liquid that permeates into the gaps in the granular layer 21b differs between areas where the pattern density is lower and areas where the pattern density is higher.

That is, there is a larger non-irradiated area around the portions where the pattern density is lower, and therefore a larger amount of the first liquid is present. On the other hand, around areas with higher pattern density there is a narrower non-irradiated area and therefore a smaller amount of first liquid.

As a result, in areas where the pattern density is lower, a larger amount of the first liquid permeates into the gaps within the granular layer 21b. For example, the entire gap is filled with the first liquid.

On the other hand, in areas where the pattern density is higher, a smaller amount of the first liquid permeates into the gaps within the granular layer 21b. For example, only a portion of the gap is filled with the first liquid.

<Pattern fixation>
Finally, the uncured first liquid contained in the film from which the second liquid has been removed is cured. The uncured first liquid can be cured, for example, by irradiating the entire film with active energy rays. As a result, a patterned film is formed.

FIG. 8 schematically shows an example of a state in which the uncured first liquid is cured by irradiating the entire surface with ultraviolet rays. As shown in FIG. 8, when the entire film is irradiated with ultraviolet rays, the uncured first liquid is cured by polymerization. As a result, a polymeric phase 21b2 is formed. Furthermore, in the cured product 21b1 constituting the granular layer 21b, further polymerization progresses due to ultraviolet irradiation. As a result, a patterned film 2 consisting of the cured product 21b1 of dispersed particles and the polymerized phase 21b2 is formed.

As mentioned above, before the entire surface is irradiated with ultraviolet rays, in the part of the granular layer 21b where the pattern density is lower, the entire gap is filled with the first liquid, and in the part where the pattern density is higher, the gap is filled with the first liquid. Only a portion is filled with the first liquid. Therefore, in the patterned film 2 obtained by irradiating the entire surface with ultraviolet rays, the portions where the pattern density is higher have a higher porosity than the portions where the pattern density is lower.

Note that, as described above, the uncured first liquid can be cured after all of the uncured first liquid existing in the non-irradiated area has moved from this area to the granular layer. Alternatively, the curing of the uncured first liquid may occur when only a portion of the uncured first liquid present in the non-irradiated area moves from this area to the granular layer. For example, irradiation of the entire film with active energy rays is performed before the second liquid is completely removed from the film (i.e., the first liquid in the non-irradiated area penetrates into the granular layer and diffuses into the granular layer). (intermediate stage), for example, the stage shown in FIG. In this way, it is possible to obtain a patterned film that has a thickness in the non-irradiated area and in which the irradiated area is thicker than the non-irradiated area.

Next, the cumulative amount of active energy rays for forming the patterned film 2 having the sidewalls 2c shown in FIGS. 1 and 2 will be described below with reference to FIGS. 9, 10, and 17.
<Accumulated light amount of active energy rays>
The method for forming a patterned film according to the present embodiment is to form a side wall 2c in the non-irradiated region R _S shown in FIGS. This is to form a patterned film 2 having the same structure. As described above, the side wall 2c has an inclination formed by continuously changing the deposited thickness of the cured product 21b1 of dispersed particles. A patterned film having such sidewalls can be formed by pattern irradiation with active energy rays at an integrated light amount exceeding the integrated light amount E _M at which the difference in height of the pattern between the irradiated area and the non-irradiated area is maximum. .

FIG. 9 is a graph schematically showing the relationship between the integrated light amount of active energy rays for a film (liquid film) made of an emulsion and the difference in height of a pattern between an irradiated area and a non-irradiated area. Here, the height difference of the pattern in the irradiated area and the non-irradiated area is the height difference between the pattern convex part in the active energy ray irradiation area and the pattern concave part in the non-irradiated area, and is simply referred to as "pattern height difference" below. There are times when that happens.

As shown in FIG. 9, as the cumulative light amount of active energy rays is increased, there exists a cumulative light amount _EM at which the pattern height difference is maximum. This is presumed to indicate that the deposition (fixation) of the dispersed particles in the irradiated area due to aggregation ("primary aggregation" to be described later) of the cured product has been completed.

In a region where the integrated light amount exceeds _EM , the pattern height difference decreases as the integrated light amount increases. This decrease in pattern height difference is due to an increase in the amount of cured particles of dispersed particles that move from the irradiated area and deposit in the non-irradiated area as the cumulative amount of light increases.

When the integrated light amount is further increased, the height difference of the pattern stops changing and saturation is reached. The cumulative amount of light when the pattern height difference stops changing and reaches saturation is hereinafter referred to as "E _S " (E _M <E _S ).

The above relationship between the integrated light amount of active energy rays and the pattern height difference is a common tendency regardless of the size of the dispersed particles contained in the emulsion. The above relationship is observed for emulsions in the range of .5 mm.

Note that the schematic graph shown in FIG. 9 does not show the influence of "secondary agglomeration" (described later) of the cured material of dispersed particles, which may occur when the integrated light amount is further increased beyond _ES . do not have. Due to secondary aggregation, a phenomenon may be observed in which the pattern height difference increases in a region exceeding the integrated light amount _ES .

FIG. 10 is a graph schematically showing the relationship between the integrated light amount of active energy rays for a film (liquid film) made of an emulsion and the inclination of the pattern sidewall. Here, the inclination of the pattern side wall is the inclination of the side wall of the convex part with respect to the base material that supports the pattern film, and means that the side wall angle (the angle formed between the base material and the side wall of the convex part) is on the acute angle side. . Here, the average of the maximum values of the slopes of the pattern sidewalls (hereinafter referred to as "maximum slopes") is defined as the slope of the pattern sidewalls.

As shown in FIG. 10, the relationship between the cumulative amount of active energy rays and the inclination of the pattern sidewall has a similar tendency to the relationship between the cumulative amount of active energy rays and the pattern height difference shown in FIG.

That is, as the integrated light amount of active energy rays is increased, the slope of the pattern side wall becomes the largest at the integrated light amount _EM where the pattern height difference is maximum, resulting in a sharp pattern.

In a region where the integrated light amount exceeds _EM , the slope of the pattern sidewall decreases as the integrated light amount increases. This decrease in the slope of the pattern sidewall is due to an increase in the amount of cured particles of the dispersed particles that move from the irradiated area and deposit in the non-irradiated area as the cumulative amount of light increases. As the cumulative amount of light increases, the slope of the pattern sidewall tends to decrease continuously.

When the integrated light amount is further increased, the change in the slope of the pattern side wall reaches saturation at _ES , where the change in the pattern height difference is saturated.

Note that the schematic graph shown in FIG. 10, like FIG. 9, does not show the influence of "secondary aggregation" (described later) of the cured product of dispersed particles. Due to secondary aggregation, a phenomenon may be observed in which the slope of the pattern sidewall increases in a region exceeding the integrated light amount _E.sub.S.

Here, the pattern height difference between the irradiated area and the non-irradiated area can be measured, for example, from the cross-sectional profile of the patterned film (see FIG. 12(a)) obtained using a 3D shape measuring device described later. Further, the maximum inclination of the pattern sidewall can be measured, for example, from the peak of a differential waveform (see FIG. 12(b)) obtained by performing differential processing on the cross-sectional profile.

In the method for forming a patterned film according to the present embodiment, the integrated light amount (exposure amount) of the active energy rays is not particularly limited as long as it exceeds the integrated light amount E _M at which the height difference of the pattern is maximum. do not have. By selecting an integrated light amount exceeding _EM , it is possible to obtain a patterned film having inclined sidewalls formed by depositing cured particles of dispersed particles.

In one example, the cumulative light amount E of the active energy rays may be larger than E _M and smaller than E _S (E _M <E<E _S ).
In addition, in other examples, the integrated light amount E of active energy rays is an integrated amount in the range of [( _ES - _EM ) x 5% + _EM ] to [( _ES - _EM ) x 95% + _EM ]. It may be the amount of light.

In addition, in other examples, the cumulative light amount of active energy rays is within the range of [(E _S - E _M ) x 10% + E _M ] to [(E _S - E _M ) x 80% + E _M ]. It may be.
In addition, in other examples, the cumulative amount of active energy rays is within the range of [( _ES - _EM ) x 20% + _EM ] to [( _ES - _EM ) x 70% + _EM ]. It may be.

Here, the cumulative light amount (mJ/cm ² ) may be the cumulative light amount when the irradiation intensity (mW/cm ² ) is kept constant and the irradiation time is changed, or the irradiation intensity is kept constant and the irradiation time is constant. It may be the cumulative amount of light when changing , or it may be the cumulative amount of light when changing both.

The mechanism of the above phenomenon shown in FIGS. 9 and 10 can be explained by the dynamic behavior within the liquid film made of the emulsion (convection within the liquid film) during irradiation with active energy rays. This will be explained below with reference to FIGS. 17 ((A) to (D)).

When irradiation of active energy rays is started on the liquid film surface (SUR) consisting of an emulsion, as shown in _FIG . a and a surface tension flow b are generated.

When irradiation with active energy rays is continued, as shown in FIG. 17(B), the dispersion particles (emulsion droplets) containing the first liquid progress in the irradiation area _RL by polymerization and aggregation, riding on the upward flow a. At the same time, surface tension b is generated in the direction of the non-irradiated area so as to be transmitted along the liquid surface.

When the irradiation with active energy rays is further continued, the aggregation (primary aggregation) of the emulsion polymer particles in the irradiation area _RL is completed, and the rise of the "primary polymerization aggregation fixed area" d shown in FIG. 17(C) is stopped. The temperature is dropping. However, since the polymerization heat is transferred to the periphery (non-irradiated area) of the irradiated region R _L , an upward flow (natural convection e) is generated in the periphery of the primary polymerization aggregation fixed region d.

When the irradiation with active energy rays is further continued, the uncured emulsion droplets riding on the upward flow (natural convection e) generated around the primary polymerization agglomeration fixing zone d reach near the liquid film surface (SUR). A part of the dispersed particles covers the irradiation area _RL , resulting in a cured product of dispersed particles (cured emulsion droplets).

A part of the dispersed particles hardened near the liquid film surface (SUR) accumulates on the top of the primary polymerization agglomeration fixation zone d, and forms a new "secondary polymerization cohesion fixation zone d" as shown in FIG. 17(D). ``It is considered to form f.

On the other hand, a flow (surface tension flow b) to the non-irradiated area continues to occur, and as shown in FIG. 17(D), a convection g is generated due to a combination of the natural convection e and the surface tension b. Another part of the dispersed particles hardened near the liquid film surface (SUR) moves to the non-irradiated area by this convection g and is deposited thereon. It is presumed that the deposition of the cured emulsion droplets forms a slope in the sidewall, thereby reducing the difference in height of the pattern between the irradiated area and the non-irradiated area.

[Second embodiment]
In the pattern forming method according to the present embodiment, the cumulative amount of active energy rays irradiated onto the film (liquid film) made of the emulsion is not limited to one type. In other words, two or more types of integrated light amounts that are larger than _EM and different from each other may be selectively irradiated onto the same plane.

As an example, a case will be described in which two types of integrated light amounts are used as active energy rays. A first integrated light amount and a second integrated light amount are selected as the two types of integrated light amounts. These two types of integrated light amounts are larger than _EM and satisfy different relationships. The step of irradiating the film made of the emulsion (liquid film) with active energy rays includes irradiating one or more first regions of the liquid film with active energy rays at a first integrated light amount; The method includes irradiating the one or more second regions with active energy rays at a second integrated light amount.

In this way, by selecting two or more types of cumulative light amount of active energy rays that exceed _EM and are different from each other, and irradiating active energy rays with different cumulative light amounts selectively within the same plane. , multiple types of patterns having different pattern sidewall inclinations can be easily formed within the same plane.

When using two or more types of cumulative light amounts, the two or more types of cumulative light amounts only need to be larger than _EM and different from each other, as described above, but in one example, at least one type of cumulative light amount is , E _M and less than E _S , and all integrated light amounts may exceed E _M and less than E _S.

In addition, when using two or more types of integrated light amount, in other examples, at least one type of integrated light amount is [(E _S - E _M ) x 5% + E _M ] to [(E _S - E _M ) x 95% +E _M ], or in the range of [(E _S - E _M ) x 10%+E _M ] to [(E _S - E _M ) x 80% + E _M ], or, It is sufficient if it is in the range of [(E _S - E _M )×20%+E _M ] to [(E _S - E _M )×70%+ E _M ]. Alternatively, two or more kinds of integrated light amounts consisting of a combination of these may be used.

In addition, when using two or more types of integrated light amounts, in other examples, all integrated light amounts are [(E _S - E _M ) x 5% + E _M ] to [(E _S - E _M ) x 95% + E _M ], or may be in the range of [(E _S - E _M ) x 10% + E _M ] to [(E _S - E _M ) x 80% + E _M ], or [( It may be in the range of [(E _S - _{E M} ) x 70% + E M ] to [(E _S - _{E M )} x 70% + E _M ].

<Effect>
As described above, according to the present embodiment, by irradiating active energy rays with an integrated light amount exceeding _EM , the non-irradiated area is provided with an inclined side wall formed by depositing a cured product of dispersed particles. A patterned film can be obtained. Furthermore, according to this embodiment, by changing the integrated light amount, the inclination of the pattern sidewall (the deposited thickness of the cured material) can be changed. Therefore, it is possible to selectively form multiple types of patterns with different pattern sidewall inclinations within the same plane by selectively irradiating two or more types of integrated light intensity exceeding _EM in the same plane. I can do it. This means that pattern films that require special expressions such as "bleeding", "blurring", and "watermarking" can be selectively formed in a non-contact manner without using a printing plate or the like.

In addition, the method for forming a patterned film according to this embodiment can be formed in a self-organized manner by simply irradiating the emulsion film with active energy rays in a pattern and then removing the second liquid. . This method does not require a guide pattern to be provided on the base material in advance, nor does it require a developing step. Therefore, this pattern film 2 can be manufactured by a simple method.

Further, while the pattern size that can be realized by the conventional technology is, for example, a line width of several nanometers to several hundred micrometers and a height difference of several nanometers to several hundred micrometers, the pattern film forming method according to the present embodiment is different. For example, a wide range of pattern sizes can be realized. For example, according to the method for forming a patterned film according to the present embodiment, a patterned film having a large line width or height difference, for example, a patterned film having a line width from a micro order to a millimeter order and a height difference from a micro order to a millimeter order. It is possible to form According to one example, according to the above method, a patterned film having a line width within a range of 10 μm to 5 mm and a pattern film having a height difference within a range of 10 μm to 2 mm can be formed.

Furthermore, the method for forming a patterned film according to the present embodiment has excellent controllability of the shape and size of the pattern, and it is possible to form patterned films of various shapes and sizes.

[Example 1]
<Preparation of first emulsion>
An O/W emulsion was prepared using the following materials.
Monomer or oligomer: Trimethylolpropane triacrylate (Light Acrylate (registered trademark) TMP-A manufactured by Kyoeisha Chemical Co., Ltd.)
Photoinitiator: 1-benzoylcyclohexanol (Lunacure (registered trademark) 200, commercially available from DKSH Japan)
Surfactant: Sodium dioctyl sulfosuccinate (Sanmorin (registered trademark) OT-70 manufactured by Sanyo Chemical Industries, Ltd. <86.7% aqueous solution>)
Second liquid: distilled water First, in a brown vial with a capacity of 50 mL, 0.375 g of Lunacure (registered trademark) 200, 0.259 g of Sanmorin (registered trademark) OT-70, and 7.5 g of light acrylate (registered trademark) Trademark) TMP-A were added in this order and subjected to rotational mixing treatment on a ball mill roll. Next, 9 g of distilled water was further added to this vial, and this was subjected to emulsification and dispersion treatment. The emulsification and dispersion treatment was performed using a homogenizer (HSIANGTAI MODEL HG200 Shaft Generator K-12S (AS ONE)). The rotation speed of the shaft was 4000 rpm, and the stirring time was 1 minute. The room temperature during the emulsification and dispersion treatment was 24.8°C. Thereafter, the vial was subjected to rotational mixing for 30 minutes. The first emulsion was prepared as described above.

<Preparation of second emulsion>
A second emulsion was prepared in the same manner as described above for the first emulsion, except that the shaft rotation speed in the emulsification and dispersion treatment was changed to 5000 rpm.

<Preparation of third emulsion>
A third emulsion was prepared in the same manner as described above for the first emulsion, except that the shaft rotation speed in the emulsification and dispersion treatment was changed to 7000 rpm.

<Measurement of particle size distribution>
Particle size distribution and average particle diameter were measured for each of the first to third emulsions. For this measurement, a measurement system was used in which a particle size distribution measuring device Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. was equipped with a liquid circulation pump Microtrac USVR manufactured by Nikkiso Co., Ltd., and the mass average diameter was determined as the average particle size. Note that the obtained emulsion is composed of dispersed particles (hereinafter also referred to as emulsion droplets) containing the first liquid and a dispersion medium containing the second liquid. The average particle diameters of the first to third emulsions are summarized in Table 1 below. Further, the particle size distribution of the first to third emulsions is shown in FIG.

<Film formation>
A plurality of films were formed using each of the first to third emulsions by the following method. First, five layers of 3M masking tape having a width of 20 mm and a thickness of 80 μm were pasted on the surface of a microscope slide glass. The center of this five-layer laminate was cut out into a rectangular shape, thereby producing a cell having a liquid reservoir with a depth of 400 μm and an opening size of 10 mm x 30 mm (hereinafter referred to as a liquid reservoir cell). did.

Next, 112 μL of emulsion was collected with a micropipette, and this was expanded and filled into a liquid reservoir cell to form a film (i.e., liquid film) made of emulsion with a thickness of approximately 375 μm, calculated considering specific gravity. did.

<Ultraviolet irradiation>
A 0.25 mm thick copper mask having striped openings was placed on the liquid film via a 1 mm thick aluminum spacer so as not to contact the liquid surface. Here, a mask having striped openings corresponding to a line-and-space pattern (line/space = 2 mm/2 mm) was used as the copper mask.

Next, using a UV parallel light exposure machine (UVC-2502S manufactured by SAN-EI ELECTRONIC), ultraviolet rays with an irradiation intensity (hereinafter referred to as "illuminance") of 4.6 mW/cm ² are applied over the mask for a predetermined period of time. Irradiated. By changing the UV irradiation time for each liquid film while keeping the illuminance constant, each liquid film was irradiated with a different arbitrary integrated light amount. As a result, the first liquid present in the area irradiated with ultraviolet rays was polymerized to form a granular layer consisting of a cured product of dispersed particles.

<Drying of membrane>
Next, the film exposed to ultraviolet light was naturally dried for 90 minutes at room temperature (21° C., 51% RH). This removed water from the membrane.

<Pattern fixation>
Finally, the entire surface of the dried film was exposed to ultraviolet light with an integrated light amount of 414 mJ/cm ² (=4.6 mW/cm ² ×90 seconds). This fixed the pattern. A patterned film was formed as described above.

<Measurement of shape of uneven pattern>
Regarding the obtained pattern film, the difference in height of the pattern between the ultraviolet irradiation area and the non-irradiation area and the maximum inclination of the pattern sidewall were measured from the cross-sectional profile in the thickness direction of the uneven pattern (line and space pattern).

In order to obtain a cross-sectional profile, aluminum was deposited to a thickness of about 80 nm on the surface of the patterned film as a sample using a vacuum deposition machine (VC-500P manufactured by JEOL Ltd.). Next, a cross-sectional profile of the uneven shape of the sample was obtained using a 3D shape measuring machine (one-shot 3D shape measuring machine VR3100 manufactured by Keyence Corporation) (see FIG. 12(a)). From the shape data obtained from the cross-sectional profile of this uneven pattern, (i) the pattern height difference and (ii) the maximum inclination of the pattern sidewall were measured.

(i) Pattern height difference From the cross-sectional profile of the uneven pattern (see FIG. 12(a)), the pattern height difference between the irradiated area and the non-irradiated area was measured. FIG. 13 shows the average value of n=5 measured values.
Although there are variations in the data shown in FIG. 13 (see below for the reason), it can be seen that roughly the same trends are observed regardless of the average particle size of the emulsion. That is, as the integrated light amount increases, the height difference of the pattern becomes maximum when the integrated light amount is about 30 mJ/cm ² to 40 mJ/cm ² . As the cumulative amount of light is further increased, the difference in height gradually becomes smaller, and eventually almost no change in the difference in height can be seen.
In the region where the pattern height difference exceeds the maximum integrated light amount, the effect of the above-mentioned convection within the liquid film increases, and the cured particles of the dispersed particles move from the ultraviolet irradiation region to the non-irradiation region. The moved hardened dispersed particles accumulate in the non-irradiated area, reducing the height difference.

In addition, in the graph for the average particle size of 28.1 μm, there is a sample that shows a tendency for the pattern height difference to become slightly larger when the integrated light amount is about 200 mJ/cm ² or more, but this is due to the secondary polymerization aggregation fixation region mentioned above. It is assumed that this is due to the fact that it was formed.

(ii) Maximum slope of pattern sidewall A differential waveform was obtained by differentiating the data obtained from the cross-sectional profile of the uneven pattern (see FIG. 12(a)) (see FIG. 12(b)). The peak value of this differential waveform was measured as the maximum slope of the pattern sidewall. The average value of the measured values of the maximum inclination was taken as the inclination of the pattern sidewall, and the results are shown in FIG.
Slope of pattern sidewall = average of maximum slope of pattern sidewall
=(Σf'(x)max－|Σf'(x)min)|/(Nmax+Nmin)
N: Number of measurement data

Although there are variations in the data shown in FIG. 14 (see below for the reason), from FIG. 14, the relationship between the cumulative amount of ultraviolet light and the slope of the pattern sidewall is It can be seen that the relationship between the pattern height difference and the pattern height difference shows roughly the same tendency.
That is, as the cumulative amount of light is increased, the slope of the pattern sidewall becomes maximum when the cumulative amount of light at which the difference in height of the pattern becomes maximum is approximately 30 mJ/cm ² to 40 mJ/cm ² . As the integrated light amount is further increased, the slope of the pattern sidewall gradually becomes smaller, and eventually almost no change is observed. The mechanism is as explained in FIG. 17.

Note that the data shown in FIGS. 13 and 14 have relatively large variations. This is because it is not possible to continuously track and measure the pattern formation process while changing the integrated light intensity for a single sample, so a separate sample must be prepared for each data point to create and evaluate the pattern. It is. However, even though there are variations, the essential trends can be extracted as described above.

<Image of pattern film surface>
The surface of each pattern film was photographed using a microscope (L-815 zoom lens manufactured by HOZAN) equipped with a USB camera (L-835 manufactured by HOZAN). Some of the images obtained in this way are shown in FIG. From FIG. 15, it can be seen that the relationship between the cumulative light amount and the pattern appearance when the first to third emulsions having different average particle diameters are used.

From the appearance of the patterned film shown in Figure 15, it can be seen that regardless of the average particle size of the emulsion, as the integrated light amount increases from around 30 mJ/cm ² to 40 mJ/cm ² , the amount of dispersed particles deposited in the non-irradiated area increases. It can be seen that the amount of cured material tends to increase. Therefore, as shown in FIG. 13, it could be confirmed from the appearance that the pattern height difference between the irradiated part and the non-irradiated part became smaller.

As mentioned above, the essential trends commonly seen in FIGS. 13 to 15 were the same regardless of the average particle size of the emulsion, but as a tendency due to the difference in the average particle size of the emulsion, The following trends can be seen. That is, when a pattern film is formed by the method for forming a pattern film according to this embodiment under the same conditions except that the average particle size of the emulsion is different, the slope of the pattern sidewall becomes smaller as the particle size becomes smaller, and the pattern becomes smaller. There is a tendency for the sharpness to decrease. The reason for this is, for example, that the smaller the particle size, the more difficult it is for polymerization to proceed under the same light source due to the effects of light scattering, etc., which makes it difficult to form a cohesive layer. Furthermore, in the case of small particle sizes, the irradiation light transmittance per unit liquid film thickness is small, and the deep part of the liquid film tends to be insufficiently cured. In this case, the exposed pattern portion may not be fixed to the base material and may float within the liquid film and move easily, which is also considered to be a contributing factor. Therefore, it is assumed that appropriate illuminance setting is required according to the particle size.

[Example 2]
The generation of convection within a liquid film due to heat of polymerization of emulsion droplets will be described below with reference to FIGS. 16 and 17. The movement of the emulsion within the liquid film during exposure was observed using the following method.
<Preparation of fourth emulsion>
The emulsion was colored by adding a blue coloring agent (Kayaset Blue A-2R manufactured by Nippon Kayaku Co., Ltd.) to the preparation of the first to third emulsions in Example 1, and the emulsion dispersion treatment conditions are listed in Table 2 below. A fourth emulsion was prepared under the same conditions and method, except that the conditions were changed to (intermittent handshake 10 times) and stirring was continued for 2 hours after the emulsification and dispersion treatment.

<Film formation>
The movement of the emulsion within the liquid film during exposure was observed using the following method.
A liquid storage cell and a microscope observation system were constructed as shown below, and these were used to directly observe the dynamic processes within the liquid film that occur when the emulsion liquid is partially irradiated with ultraviolet (UV) light. .

・Preparation of liquid reservoir cell A 0.8 mm thick multipurpose strong double-sided tape made by 3M was attached to one side of a slide glass. With the release film attached, a cut was made with a cutter about 5 mm from the long edge to the center and about 8 mm as the bottom of the liquid reservoir cell, and then this part was peeled off. Note that the portion of the double-sided tape protruding from the slide glass was cut and removed. By peeling off the remaining release film from the slide glass with double-sided tape prepared in this way and attaching another slide glass with the long sides aligned, a liquid reservoir cell for observation is created. Created.

The liquid reservoir cell is made by pasting these two glass slides together with the double-sided tape with the above cut in it, with a gap of 0.8 mm thick in the double-sided tape, and a length of about 8 mm and a depth of about 5 mm in the center. , the thickness of the gap is 0.8 mm.

- Preparation of observation system using a microscope The above liquid reservoir cell was fixed to a square element holder on an optical laboratory bench. At this time, the liquid reservoir cell was fixed so as to be perpendicular to the horizontally installed optical experimental table. Next, using a copper plate (thickness 0.25 mm) provided with a 1 mm wide slit as a mask, a UV-LED irradiator (described later) was placed so that UV irradiation could be performed from directly above it. In order to take pictures from the side of the liquid reservoir cell placed perpendicular to the optical laboratory table, a microscope was installed so that its optical axis was parallel to the optical laboratory table. In this way, an observation system using a microscope was prepared.

The fourth emulsion was expanded and filled into this liquid reservoir cell using a micropipette, and left for 7 minutes to form a film (ie, a liquid film) made of the emulsion. The purpose of this 7 minute standing time was to allow the emulsion to settle a little and form a supernatant layer, thereby making it easier to observe the movement of the liquid.

<Ultraviolet irradiation>
A UV-LED irradiator (EXECURE-H-1VC II manufactured by HOYA CANDED OPTRONICS) was applied to the liquid film directly above a 0.25 mm thick copper mask with a 1 mm wide slit at an illuminance of 9. Ultraviolet light (λ=365 nm) of 8 mW/cm ² was irradiated for 57 seconds. The cumulative amount of light at this time was 558.6 mJ/cm ² .

The process from the start of UV irradiation was observed from the side of the cell (in a direction parallel to the optical bench) using a microscope (L-816 zoom lens manufactured by HOZAN) equipped with a USB camera (L-835 manufactured by HOZAN). I shot a video. Figure 16 is a photograph taken from a video showing the movement of the liquid. Based on FIG. 16, the flow phenomenon in the liquid film due to the polymerization heat of the emulsion droplets and the agglomeration behavior of the emulsion droplets are summarized as an illustration in FIG. Hereinafter, based on FIG. 17, the mechanism of occurrence of convection in the liquid film due to the heat of polymerization of the emulsion droplets, as estimated by the present inventor, will be explained.

[Figure 17(A): 3 seconds elapsed from the start of ultraviolet (UV) irradiation]
Three seconds after the start of ultraviolet irradiation on the liquid film surface (SUR) made of the emulsion, an upward flow a due to buoyancy due to the heat generated by polymerization of the emulsion and a surface tension flow b occur in the ultraviolet irradiation region R _L. .

[Figure 17(B): 4 to 6 seconds elapsed from the start of ultraviolet (UV) irradiation]
When irradiation with ultraviolet rays is continued, the upward flow a continues due to buoyancy due to heat generated by polymerization of the emulsion. At the timing when the swelling of the emulsion settling interface c riding on this upward flow a reaches the liquid surface, the non-irradiated area _R Occurs in the area direction. During this process, the aggregation of the emulsion droplets in the irradiation region R _L (polymerization and aggregation progress region) also progresses at the same time.

[Figure 17(C): 7 seconds have elapsed since the start of ultraviolet (UV) irradiation]
When irradiation with ultraviolet rays is continued, the aggregation of the emulsion polymer particles in the irradiation area _RL is completed, and the rise of the "primary polymerization aggregation fixed area" d is stopped. In this way, the movement of the irradiated area _RL stops when it is aggregated and fixed, and the temperature decreases. However, since the polymerization heat is transferred to the periphery (non-irradiated area), the uncured emulsion droplets existing in the periphery of the primary polymerization coagulation fixation zone d are affected by natural convection e toward the liquid film surface SUR. Occur.

[Figure 17(D): 8 seconds to 57 seconds elapsed from the start of ultraviolet (UV) irradiation]
The uncured emulsion droplets riding on the upward flow (natural convection e) generated around the primary polymerization agglomeration fixation zone d reach the vicinity of the liquid film surface SUR, and part of them covers the ultraviolet irradiation area _RL . , a "secondary polymerization agglomeration fixation area" f is newly piled up above the outer periphery of the primary polymerization aggregation fixation area d.

On the other hand, surface tension flow b, which is a flow toward the non-irradiated area, continues to occur. At this stage, the emulsion droplets move to the non-irradiated area by convection g caused by a combination of upward flow (natural convection e) and surface tension flow b. It is thought that the emulsion droplets that move to the non-irradiated area due to this flow are a mixture of those that have been UV-cured near the surface and those that are carried in an uncured state. It is inferred that the cured emulsion droplets (cured material of dispersed particles) included in this flow are deposited in the non-irradiated area, and this forms the deposited layer that becomes the slope of the pattern sidewall described above.

[Figure 17(E): Stopping ultraviolet (UV) irradiation]
When UV irradiation is stopped, additional polymerization heat is no longer generated, so the polymer coagulation and fixation zone, which had been raised by the buoyancy caused by the polymerization heat, cools and sinks (h). In parallel with this, uncured emulsion droplets that had continued to rise at the outer periphery of the polymerization exothermic aggregation zone were also observed to sink.

DESCRIPTION OF SYMBOLS 1... Base material, 2... Patterned film, 2a... Film made of emulsion, 21a... Dispersed particles, 21a'... Combined body, 21b... Granular layer, 21b1... Cured product of dispersed particles, 21b2... Polymerized phase, 2c... Side wall, 22...Dispersion medium.

Claims (9)

Forming on a substrate a film made of an emulsion containing dispersed particles containing a first liquid that hardens upon irradiation with active energy rays and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays. ,
The film was irradiated with the active energy rays by irradiating the active energy rays in a pattern with an integrated light amount exceeding the integrated light amount at which the height difference of the pattern between the irradiated area and the non-irradiated area of the active energy rays was maximum. curing the first liquid present in the region;
removing at least a portion of the second liquid from the film after irradiation with the active energy ray;
A method for forming a patterned film, the method comprising: curing the uncured first liquid contained in the film from which at least a portion of the second liquid has been removed. Forming on a substrate a film made of an emulsion containing dispersed particles containing a first liquid that hardens upon irradiation with active energy rays and a dispersion medium containing a second liquid that does not harden upon irradiation with active energy rays. ,
The film was irradiated with the active energy rays by irradiating the active energy rays in a pattern with an integrated light amount exceeding the integrated light amount at which the height difference of the pattern between the irradiated area and the non-irradiated area of the active energy rays was maximum. Curing the dispersed particles present in the region to form a granular layer made of a cured product of the dispersed particles;
After irradiation with the active energy rays, at least a portion of the second liquid is removed from the film, and at least a portion of the uncured first liquid is transferred from the region not irradiated with the active energy rays to the granular particles. moving to a layer;
A method for forming a patterned film, the method comprising: curing the uncured first liquid contained in the film from which at least a portion of the second liquid has been removed. 3. The method for forming a pattern film according to claim 2, wherein the pattern film includes an inclined side wall formed by depositing a cured product of the dispersed particles in a region not irradiated with the active energy ray. The cured product of the dispersed particles deposited in the non-irradiation area of the active energy ray and forming the slope of the side wall is the cured product of the dispersed particles that have moved from the area irradiated with the active energy ray to the non-irradiation area. The method for forming a patterned film according to claim 3. When the film is irradiated with active energy rays, the cumulative amount of light at which the difference in height of the pattern between the active energy ray irradiation area and the non-irradiation area is maximum is _EM , and the cumulative light amount of the active energy rays is increased from _EM . A claim comprising irradiating active energy rays with an integrated light amount greater than E _M and smaller than E _S , where E _S is the integrated light amount when the change in height difference reaches saturation. 5. The method for forming a patterned film according to any one of 1 to 4. The active energy rays are irradiated onto the film at an integrated light intensity in the range of [( _ES - _EM ) x 5% + _EM ] to [( _ES - _EM ) x 95% + _EM ]. The method for forming a patterned film according to claim 5, comprising irradiating with. The irradiation of the active energy ray to the film includes irradiating the active energy ray to one or more first regions of the film at a first integrated light amount, and irradiating the active energy ray to one or more second regions of the film. irradiating active energy rays with a second integrated light amount different from the first integrated light amount, wherein the first integrated light amount and the second integrated light amount are larger than the integrated light amount at which the height difference is maximum. 7. The method for forming a patterned film according to any one of 1 to 6. A patterned film obtained by the method according to any one of claims 1 to 7. An article comprising a patterned film obtained by the method according to any one of claims 1 to 7, and a base material supporting the patterned film.