JP2018040931A - Method of forming light selective absorption resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a light selective absorption resin film with high homogeneous thickness, on a square substrate, by spin coating.SOLUTION: The present invention provides a method for forming a resin film having a light selection absorption function (light selective absorption resin film), on a square substrate, by spin coating. An acceleration time up to a maximum number of revolutions is less than 2 seconds, preferably less than 0.5 seconds, and a duration of the maximum number of revolutions is less than 5 seconds, preferably less than 3 seconds. The maximum number of revolutions is 1000 rpm or more, preferably 1500 rpm or more.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for forming a light selective absorption resin film using a spin coating method, and more particularly to a method for efficiently forming a uniform light selective absorption resin film on a square substrate such as a quadrangle or pentagon.

  For image sensor chips or solid-state image sensors built into video cameras, digital cameras, camera phones, tablet terminals with cameras, in-vehicle cameras, surveillance cameras, etc. An optical filter for reflecting the light is used.

  As such an optical filter, in addition to a kneading type in which a compound capable of absorbing light of a specific wavelength is contained in the substrate itself, a functional film that can extract (pass) or cut light of a specific wavelength on the substrate. There are stacked types.

  As the functional film used for the laminated type, there are an inorganic vapor-deposited film such as silica and titanium oxide, and a resin thin film containing a dye or a pigment. A spin coating method is known as a method for efficiently forming a homogeneous resin thin film on a substrate.

  JP 2013-137337 (Patent Document 1) discloses an infrared cut filter in which an infrared absorbing liquid composition containing an infrared absorbent, a polymerizable compound and a solvent is applied onto a glass substrate by a spin coating method. According to the manufacturing method, it is possible to obtain a resin film having a high uniformity of film thickness as compared with a resin film prepared by a bar coating method, and as a result, an infrared cut filter having excellent incident angle dependency characteristics can be obtained. It is disclosed.

  In Patent Document 1, from the viewpoint of film thickness uniformity, the rotation speed of the spin coater is preferably 1000 rpm to 4000 rpm, more preferably 1500 rpm to 2500 rpm, and the spin time for spin coating is 5 to 500 seconds, preferably 10 to 10 rpm. It is described as 400 seconds, or even 15-300 seconds (paragraph 0016). In the examples, cesium tungsten oxide is used as the infrared absorbing material, and the polymerizable compound and the methacrylate binder resin are dissolved in cyclohexanone (composition A) or propylene glycol monomethyl ether (composition B). An example in which a liquid composition or an infrared-absorbing liquid composition using a diimmonium dye (composition C) as an infrared-absorbing substance is applied to an 8-inch silicon substrate by a spin coating method is shown. Table 1 shows that in the spin coating method, the film thickness distribution tends to be inferior even if the rotational speed is too low (900 rpm) or too high (4500 rpm). In addition, it does not describe about the rotation time employ | adopted in the Example.

  JP-A-2006-27400 (Patent Document 2) discloses a liquid alicyclic epoxy resin (weight average molecular weight 120) and a solid alicyclic epoxy resin on an 8-inch (about 20 cm) round glass substrate. A liquid resin composition in which a mixed epoxy resin (weight average molecular weight 2900), a cationic curing agent, and phthalocyanine were dissolved in a mixed solvent of propylene glycol monomethyl ether (PGMEA) and tetrahydrofuran was formed using a spin coater. It is disclosed. Here, the spin coating conditions were that acceleration up to the maximum rotation speed (2500 rpm, 2000 rpm, 1500 rpm) was performed over 3 seconds, and the maximum rotation speed was continued for a predetermined time, and then returned to 0 rpm over 3 seconds (Example) ). In Patent Document 2, the film forming property, transmittance, adhesiveness, and heat resistance of the obtained light selective absorption resin film are evaluated.

  JP-A-2006-81056 (Patent Document 3) discloses a liquid alicyclic epoxy resin (weight average molecular weight 120) and a solid alicyclic epoxy resin (weight average molecular weight) on an 8-inch round glass substrate. 2900), a liquid resin composition in which a mixed epoxy resin, a cationic curing agent, and phthalocyanine are dissolved in a mixed solvent of propylene glycol monomethyl ether (PGMEA) and tetrahydrofuran is disclosed to form a film using a spin coater. ing. The spin coating conditions here were accelerated to 2000 rpm for 3 seconds, continued at 2000 rpm for 20 seconds, and then returned to 0 rpm for 3 seconds (Example). In patent document 3, the average surface roughness, weather resistance, and transmittance of the obtained light selective absorption resin film are evaluated.

  By the way, the shape of the optical filter is roughly classified into a circular shape and a rectangular shape. When a rectangular optical filter is manufactured by a spin coating method, there are a method using a rectangular substrate and a method of manufacturing an optical filter manufactured using a circular substrate by cutting it into a predetermined rectangular shape. In the latter case, a waste portion is generated, so the former method is desired from an economic viewpoint. Further, when a multilayer film combining a resin thin film and an inorganic vapor deposition film is employed as the functional film, a square substrate is preferably employed in relation to the vapor deposition process.

As a technique for forming a light selective absorption resin film by a spin coat method using a square substrate, for example, in the example of JP-A-2014-63144 (Patent Document 4), on a glass substrate of 100 × 100 mm, An optical filter having a near-infrared absorbing layer with a film thickness of 3 μm is applied by applying a composition for forming a near-infrared absorbing layer in which fluorene polyester, a silane coupling agent and an NIR dye are dissolved in cyclohexanone by spin coating at 800 rpm. It is disclosed that it was manufactured.
For such optical filters, the transmittance as a filter, the reliability of the transmittance under high temperature and high humidity, and the adhesiveness of the filter are evaluated.

  In JP-A-2006-71323 (Patent Document 5), a base layer is formed on a 60 mm × 60 mm glass substrate by spin coating, and then a polyimide resin and phthalocyanine are formed on the base layer with γ-butyrolactone. The Example which formed the resin thin film for photoselections using the melt | dissolved resin solution is disclosed. The spin coating conditions disclosed here accelerate to 1000 rpm in 0.2 seconds, hold 1000 rpm for 10 seconds, and then return to 0 rotation over 0.2 seconds (paragraph 0155). About the obtained near-infrared cut filter, the maximum absorption wavelength was measured and the peeling resistance with respect to the glass substrate of a resin thin film was evaluated.

JP 2013-137337 A JP-A-2006-27400 Japanese Patent Laid-Open No. 2006-81056 JP 2014-63144 A JP 2006-71323 A

  When the resin thin film is formed on the quadrilateral substrate under the conditions of the spin coating method for forming the resin thin film on the circular substrate as disclosed in Patent Documents 2 and 3, the film thickness at the four corners is near the center. There is a tendency to become thicker than. When a resin thin film containing a pigment is formed, such as an infrared cut filter, the pigment tends to become thicker at thicker portions, so the visible light transmission at the four corners decreases, resulting in a decrease in optical filter performance. Cause. Such a problem is a newly recognized problem in the spin coating method using a quadrangular substrate, and it is not clear why the film thickness uniformity in the quadrangular substrate is reduced, but the resin solution flows in the four corners. It can be thought that it accumulates.

  In Patent Documents 4 and 5, the film thickness distribution is not specifically described. However, when a resin thin film is formed on a quadrilateral substrate, the number of rotations is reduced compared to the case of using a circular substrate of the same size. The reality is that the uniformity of the formed film is ensured.

  However, when the rotational speed is lowered, the diffusion casting of the resin composition and the volatilization of the solvent are slowed, and therefore it is necessary to lengthen the rotational time. This reduces the productivity as compared with the case where a circular substrate is used.

  The present invention has been made in view of the circumstances as described above. The object of the present invention is to form a light-selective absorption resin film having high film thickness uniformity including a corner portion by a spin coating method. It is to provide a method of forming on a substrate.

  The present inventor completed various aspects of the present invention by variously examining spin coating conditions, the composition of the resin composition, the type of solvent, and the like when forming a light selective absorption resin film on a square substrate by spin coating. did.

  That is, in the method for forming a light selective absorption resin film according to the present invention, a resin film having a light selective absorption function (light selective absorption resin film) is applied onto a square substrate by dropping a resin solution that is a material of the resin film. In this method, the acceleration time to the maximum rotational speed is less than 2 seconds, and the duration of the maximum rotational speed is less than 5 seconds.

  It is preferable that the maximum rotation speed is 1000 rpm or more, the acceleration time is less than 0.5 seconds, and the duration time is less than 3 seconds. More preferably, the rotational speed is 1500 rpm or more, the acceleration time is less than 0.2 seconds, and the duration is less than 3 seconds.

The spin coating step is preferably performed in an open system that can volatilize the solvent of the resin solution.
The spin coating process is preferably performed in a state where a top plate to which droplets can adhere is provided above the surface of the substrate on which the light selective absorption resin film is formed. Further, a droplet adhesion preventing plate having a size larger than that of the substrate is provided on the opposite side of the surface of the substrate on which the light selective absorption resin film is formed, and between the substrate and the droplet adhesion preventing plate. The distance is preferably less than 1 mm.

  The resin solution is preferably a resin solution containing 10% or more of an organic solvent having a vapor pressure of 1 kPa or more at 20 ° C. or more. The solid content in the resin solution is preferably 5 to 50% by mass.

The resin solution is preferably a solution obtained by dissolving the cationic curable resin composition with the solvent, and preferably contains a light selective absorbent.
The viscosity of the resin solution is preferably 0.1 to 100 mPa · s.

The substrate is preferably a square having at least one side of 30 mm to 120 mm.
It is preferable that the resin solution has no fluidity after the spin coating process.

  Another aspect of the present invention is a cut filter manufacturing method including the method for forming a light selective absorption resin film of the present invention.

  Furthermore, in another aspect of the present invention, a near infrared or infrared cut filter in which a light selective absorption resin film is laminated on a square substrate, the light selective absorption resin film is obtained by curing an epoxy resin with a cationic curing catalyst. It is a cured product and contains an oxirane ring-containing compound as a light selective absorbent, and the deviation of the transmittance wavelength of the light selective absorption resin film is that of light in the visible light wavelength region of 600 to 700 nm, excluding the edge of 1 mm. A near infrared ray or infrared cut filter having a wavelength of 10% or less as a wavelength at which the transmittance is 50% is also included.

  According to the method for forming a light selective absorption resin film of the present invention, a light selective absorption resin film having excellent film thickness uniformity can be formed in a short time even on a rectangular substrate. It becomes possible to efficiently produce a rectangular optical filter having a high uniformity of the rate (or light absorption rate of a specific wavelength).

FIG. 1 is a schematic view for explaining one embodiment of a method for forming a light selective absorption resin film of the present invention. It is a figure for demonstrating the relationship between the transmittance | permeability spectrum of a light selective absorption resin film, and the uniformity of a film thickness. 2 is a transmittance spectrum of the light selective absorption resin film laminate obtained in Example 1. FIG. 2 is a transmittance spectrum of a light selective absorption resin film laminate obtained in Comparative Example 1. FIG.

  The method for forming a light selective absorption resin film of the present invention is a method of forming a resin film (light selective absorption resin film) having a light selective absorption function on a square substrate by a spin coating method up to the maximum number of rotations. The acceleration time is less than 2 seconds, and the duration of the maximum rotational speed is less than 5 seconds.

〔substrate〕
The substrate used in the forming method of the present invention is a substrate having a flat surface on which a light selective absorption resin film is laminated. In addition to a substrate serving as a support for the light selective absorption resin film in an optical film, an optical sensor such as an image sensor. The concept includes a member to be coated having a flat surface on which a light selective absorption resin film can be laminated.

  The material of the substrate used in the forming method of the present invention is not particularly limited, but a material having sufficient and sufficient strength and heat resistance as a support for the resin film is preferable. From this point, glass, metal, ceramic, thermosetting resin A manufactured substrate is used. Further, the substrate has a flat surface on which the light selective absorption resin film is laminated, and the flat surface has a square shape such as a triangle, a quadrangle, a pentagon, and a hexagon. Usually, a quadrangle such as a square or a rectangle is preferably used, but a pentagon formed by cutting a part of a vertex is also preferably used.

  Although the substrate size is not limited, when an optical filter is produced by forming a light selective absorption resin film on the substrate by the method of the present invention, usually a rectangular substrate having a side of 30 mm to 100 mm, preferably 50 to 120 mm, more preferably A square substrate of 60 mm × 60 mm to 100 mm × 100 mm is preferably used. The forming method of the present invention is not limited to a square substrate of these sizes, but can be applied to a rectangular substrate having at least one side of 30 to 120 mm.

  The thickness of the substrate varies depending on the type and purpose of the substrate, but when manufacturing an optical filter using the method for forming a resin film of the present invention, the thickness of the substrate to be used is usually from the viewpoint of thinness and weight reduction, 0.05 mm to 2 mm, preferably 0.1 to 0.5 mm.

[Spin coating process]
Spin coating is a thin film in which a resin solution, which is a material for a resin film, is dropped on a substrate and then rotated at a high speed to cast and diffuse the resin solution on the substrate by centrifugal force and to evaporate the solvent. It is the film-forming method of forming.

(1) Dropping step At the time of spin coating, first, a predetermined amount of a resin solution as a material for the resin film is dropped on the substrate.
The dropping rate is not particularly limited, but it is preferably dropped at about 0.1 to 5 g / sec in view of the relationship with the evaporation rate of the solvent.
The dripping amount is appropriately set according to the substrate size, the thickness of the resin film to be formed, the solid content concentration of the resin solution, the resin composition, and the like.

(2) Rotation condition (2-1) Rotation speed and rotation time The rotation speed (maximum rotation speed) when forming a uniform film in spin coating is preferably 1000 to 8000 rpm, more preferably 1500 to 3000 rpm, and still more preferably. In the range of 1800-2500 rpm, it is suitably set in relation to the rotation time, the composition of the resin solution, the conditions of the spin coater, and the like.

  The rotation time (the duration of the maximum rotation speed) is preferably less than 5 seconds from the viewpoint of reducing the deviation. More preferably, it is less than 3 seconds, and in order to volatilize a solvent, it is preferable to set it as 0.1 second or more, More preferably, it is 0.5 second or more. Conventionally, when a light selective absorption resin film for an optical filter is formed by spin coating, the rotation time is about 10 to 30 seconds. The present invention is characterized in that the number of rotations is high and the rotation time is short compared to the conventional spin coating conditions for forming a resin thin film on a square substrate.

In the forming method of the present invention, the resin solution can be cast and diffused to the corners on the substrate in a short time by rotating at a high speed. On the other hand, at high speed rotation, the resin solution tends to flow out and the amount of the resin solution scattered tends to increase. However, in the present invention, a combination in which the evaporation of the solvent and the drying and solidification of the resin composition are faster than before is selected. By doing so, the rotation time is shortened, and the increase in the amount of the resin liquid scattered is suppressed.
Moreover, centrifugal force and airflow are generated by high-speed rotation, and an environment in which the solvent is easily evaporated is obtained. Also from this point, the outflow of the resin solution from the peripheral edge can be suppressed.

  The “maximum number of revolutions” in this specification includes the case where the number of revolutions of 1000 to 8000 rpm continuously changes. When the number of revolutions changes within the range of the maximum number of revolutions, “Time” refers to the total time. On the other hand, when the rotation speed is reduced to less than 1000 rpm after rotating at the maximum rotation speed for less than 5 seconds and then increased again to 1000 rpm or more, the rotation time at the maximum rotation speed after deceleration is as follows. It is not included in the duration of the maximum speed.

(2-2) Acceleration time to maximum rotation speed Time (acceleration time) from the start of rotation to reaching the maximum rotation speed is less than 2 seconds, preferably less than 1 second, more preferably less than 0.5 second, More preferably, it is less than 0.3 second, Especially preferably, it is less than 0.2 second, Most preferably, it is 0.1 second or less. By rapidly reaching the maximum number of rotations in a short time, the resin solution is cast and diffused to the periphery of the substrate even though the solvent evaporates quickly. In the case of a circular substrate, since the distance from the center to the peripheral edge is constant, the resin solution was able to spread uniformly over the entire base material, but in the case of a rectangular substrate, the reason is not clear, but the corner of the rectangular substrate is not clear. There is a tendency that the resin solution tends to accumulate at corners (four corners in the case of a square substrate). In this regard, in the present invention, the resin solution is prevented from accumulating at the corners of the substrate by rapidly accelerating to the maximum rotational speed.

  The time until the start of rotation after dropping is not particularly limited, but is preferably started immediately after dropping. It is preferable to start rotation within a time during which local volatilization of the resin solution does not occur, specifically within 1 minute, preferably 10 seconds or less.

  The “acceleration time” is the number of rotations of 1000 rpm or more from the start of rotation of 200 rpm or more after the resin solution is applied to the substrate (after dropping), and the solvent in the resin solution as the material of the resin film can be volatilized. The time to reach. Therefore, the rotation time that is preliminarily less than 200 rpm and the rotation time during application (or dropping) of the resin solution are not included.

(2-3) Deceleration time to stop rotation After continuing the maximum rotation speed for a predetermined time, the rotation is then stopped. The time for stopping the rotation (deceleration time) is 2 seconds or less, preferably 1 second or less, more preferably 0.5 seconds or less. In order to eliminate the unevenness of the coating state of the resin solution due to the centrifugal force, it is preferable to perform the transition to the stopped state in a short time as in the acceleration time up to the maximum rotational speed.
The method for stopping the rotation is not particularly limited as long as it is not a method that impairs the uniformity of the formed resin film.

(2-4) Spin coating environment The formation method of the present invention is also characterized in that the spin coating process as described above is performed in an open system capable of evaporating the solvent.

  By carrying out in an open system, the solvent can be efficiently evaporated. Furthermore, by performing high-speed rotation in an open system, an air flow is generated by rotation, thereby increasing the drying efficiency. As described above, by performing an open system, drying due to solvent volatilization is accelerated, but coupled with shortening the rotation time than before, the central portion is not made too thin, and the resin is evenly distributed to the apex corner of the square. In other words, the film thickness deviation can be suppressed so as not to cause a difference in film thickness between the central part of the side and the apex part having different distances from the center.

On the other hand, in the conventional closed system spin coating method, the resin solution is prevented from flowing out of the substrate, and the system is filled with the volatile solvent. As a result, the evaporation of the solvent is suppressed. Even if it is long, the central portion is not thinned by casting diffusion. Rather, by increasing the rotation time, the resin solution can be cast to the corner, and as a result, it is possible to suppress the deviation in film thickness due to the difference in distance from the center. However, spin coating in such a closed system has a problem that efficiency is poor in terms of productivity because of a long rotation time, evaporation of the solvent, and drying of the resin layer.
In the method of the present invention, by combining the conditions of application in an open system, high-speed rotation and short-time rotation, the waste of the resin due to outflow is reduced despite the condition that the resin solution flows out. It is possible to prevent the resin amount from being excessively reduced, and to suppress the deviation in the film thickness at the corners of the side central portions having different distances from the center. Furthermore, since drying is quick, it becomes possible to satisfy the demand for production efficiency.

(2-5) Spin coater The spin coater as described above is not particularly limited, and commonly used spin coaters, commercially available products, and the like can be used. An open type spin coater is preferable.

When an open type spin coater is used, it is preferable to provide a top plate 2 for catching scattering above the coating surface of the rectangular substrate 1 as shown in FIG. Thereby, it can prevent that the scattered liquid composition falls on a coating film again during rotation and / or rotation stop.
In FIG. 1, reference numeral 3 denotes a resin solution dropped on the square substrate 1, and the square substrate 1 is placed on a rotary table 5 that is rotated by a rotary shaft 4.
Further, as shown in FIG. 1, the adhesion of droplets to the back surface of the substrate 1 (the surface opposite to the surface on which the resin film is formed) on the opposite side of the surface on which the resin film is formed on the substrate 1 is prevented. A droplet adhesion preventing plate 6 may be provided. The droplet adhesion preventing plate 6 can prevent the droplets from adhering to the back surface of the rectangular substrate 1 by reducing the distance to the rectangular substrate 1. The distance (d) between the rectangular substrate 1 and the droplet adhesion preventing plate 6 is preferably 1 mm or less.

  In FIG. 1, both the top plate 2 and the droplet adhesion preventing plate 6 are provided. However, the spin coater employed in the forming method of the present invention is not limited to this, and the top plate and the droplet adhesion preventing plate are used. Only one of them may be provided.

[Resin solution]
The light selective absorption resin film formed by the forming method of the present invention is a cured film of a resin solution dropped on a substrate. The resin solution used as a material is obtained by dissolving a resin composition containing a resin (or compound) serving as a resin film component and a light selective absorbent in a solvent. Hereinafter, the resin composition and the solvent will be described in detail.

(1) Resin composition (1-1) Base resin The base resin used in the resin fat composition forming the light selective absorption resin film can provide a highly transparent light selective absorption resin film for optical use. And after spin coating, it is a resin that can be in a state of no fluidity when the rotation is stopped.

  Specifically, after evaporation of the solvent by spin coating, the composition may be in a state where the fluidity of the composition is lost or solidified, and may be a composition of a thermoplastic resin or a thermosetting resin. From this point of view, it is possible to use a thermoplastic resin, a heat or photocurable resin composition having a glass transition point of 80 ° C. or higher, but from the viewpoint of heat resistance, it is necessary to use a heat or photocurable resin. preferable.

Resins that are cured (polymerized) by heat or light include compounds having a curable functional group, such as oxirane groups (oxirane rings), oxetane groups (oxetane rings), ethylene sulfide groups, dioxolane groups, trioxolane groups, vinyl ether groups. A cation curable group such as a styryl group; a radical curable group such as an acryl group, a methacryl group or a vinyl group; a compound having a curable functional group such as
Here, a group containing an oxirane ring which is a three-membered ether is also referred to as an “epoxy group”. In the “epoxy group”, in addition to an epoxy group in a narrow sense, a group in which an oxirane ring is bonded to carbon such as a glycidyl group, a group including an ether bond or an ester bond such as a glycidyl ether group and a glycidyl ester group, An epoxy cyclohexane ring and the like are included.

  Of the curable resins that are cured by heat or light, a cation curable resin that generates a cationic species from the catalyst by heat or light and is cured by a cation curing reaction thereby is preferable. Cationic curing (polymerization) is advantageous in that it is less susceptible to curing inhibition by oxygen and has less shrinkage during curing than radical polymerization.

In addition, since fluidity tends to be lost after spin coating, a high molecular weight resin that can be solidified in a state where the solvent evaporation of the composition has progressed (a state in which the resin fraction has increased), or a part of cross-linking curing is used. Resin compositions that are initiated and lose fluidity are preferred.
From this point, a thermosetting resin composition that can evaporate the solvent to such an extent that fluidity is lost by the spin coating process is preferably used.

As the thermosetting resin, a polycyclic aromatic polymer, a polyimide resin, an epoxy resin, or the like can be used.
As the cationic curable thermosetting resin, an epoxy resin is particularly preferably used. Preferred examples of the epoxy compound that is a constituent monomer of the epoxy resin include alicyclic epoxy compounds, hydrogenated epoxy compounds, aromatic epoxy compounds, and aliphatic epoxy compounds. From the viewpoint of heat resistance and strength, (hydrogenated) aromatic epoxy resins and alicyclic epoxy resins are preferably used.

  Examples of the alicyclic epoxy group include an epoxycyclohexane group (epoxycyclohexane skeleton), an epoxy group added to a cyclic aliphatic hydrocarbon directly or via a hydrocarbon (particularly an oxirane ring), and the like. Moreover, the polyfunctional alicyclic epoxy compound which has two or more alicyclic epoxy groups in a molecule | numerator at the point which can raise a hardening rate more may be sufficient.

  Specifically, for example, YED-216D manufactured by Japan Epoxy Resin Co., Ltd., YL-7217 manufactured by Japan Epoxy Resin Co., Ltd. (epoxy equivalent 437, oxyalkylene chain is oxybutylene, liquid epoxy resin (10 ° C. or higher); high molecular weight Epoxy resin (for example, hydrogenated bisphenol (manufactured by Japan Epoxy Resin, YL-7170, epoxy equivalent 1000, solid hydrogenated epoxy resin); alicyclic solid epoxy resin (manufactured by Daicel Industries, EHPE-3150); alicyclic Examples thereof include liquid epoxy resins (Delcel Kogyo Co., Celoxide 2081), or mixtures thereof, of which, since they can be dissolved in a solvent and easily solidify by evaporation of the solvent, they are solid epoxy at room temperature. A resin is preferably used, and the coating film is easily solidified at room temperature. Sea urchin, preferably a weight average molecular weight of 1000 or more, in order to more weight average molecular weight of 2,000 to well more preferred. Compatibility with a solvent, preferably a weight average molecular weight of 100,000 or less, preferably more weight average molecular weight of 10,000 or less.

(1-2) Photoselective Absorber As the photoselective absorber, a dye having a π electron bond in the molecule is preferable. The dye having a π electron bond in the molecule is preferably a compound containing an aromatic ring. More preferred are compounds containing two or more aromatic rings in one molecule. In addition, as an optical filter, it is preferable that the pigment | dye which has (pi) electron bond in the said molecule | numerator has an absorption maximum in the wavelength range of 600-900 nm, ie, a specific pigment | dye. In the case of an infrared or near-infrared cut filter, it is preferable to have an absorption maximum in the wavelength region of 600 to 900 nm.

  Examples of the dye having a π bond in the molecule include phthalocyanine dyes, porphyrin dyes, cyanine dyes, nickel complex dyes, copper ion dyes, and the like, and one or more of these are used. can do. From the viewpoint of heat resistance and weather resistance, a dye having neither a zwitterionic structure nor a cationic structure is preferable, and phthalocyanine dyes and porphyrin dyes are particularly preferable, and phthalocyanine dyes are more preferable. Further, from the viewpoint of high transparency in the visible light region of 400 to 600 nm, high absorption coefficient of 600 to 1100 nm, and high weather resistance after vapor deposition, oxocarbon compounds such as squarylium dyes and croconium dyes are preferable. .

  The oxocarbon compound is a compound having an oxocarbon skeleton in the chemical structure. Specifically, a squarylium compound represented by the following formula (1) or a croconium compound represented by the following formula (2) is used. Used.

R ^S1 and R ^S2 in the formula (1), R ^C1 and R ^C2 in the formula (2) may be the same or different, and each independently represents a structure represented by the following (1a) or (2a) Unit.

  In formula (1a), ring A is a 4- to 9-membered, preferably 6- to 8-membered unsaturated hydrocarbon ring. X and Y are each independently an organic group or a polar functional group. n is an integer of 0 to 6, and when n is 2 or more, the plurality of Y may be the same or different. Ring B is an optionally substituted alicyclic heterocycle, aromatic heterocycle or a condensed ring containing these ring structures. In addition, * represents the coupling | bond part with the 4-membered ring in Formula (1) or the 5-membered ring in Formula (2).

  Examples of the structure of ring A include cyclobutene, cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene, cycloheptene, cycloheptadiene, cycloheptatriene, cyclooctene, cyclooctadiene, cyclooctatriene, cyclononene, cyclononadiene, cyclononatriene, Examples include cycloalkene structures such as cyclononatetraene. Of these, cycloalkane monoenes such as cyclopentene, cyclohexene, cycloheptene, and cyclooctene are preferable.

  Examples of the aromatic heterocyclic ring constituting the ring B include a 5- or 6-membered monocyclic aromatic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, Examples thereof include condensed bicyclic or tricyclic condensed rings containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and more specifically, a pyridine ring, a pyrazine Ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, naphthyridine ring, cinnoline ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, thiophene ring, furan ring, Thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benztri Tetrazole ring, benzothiazole ring, benzoxazole ring, purine ring, carbazole ring.

  As the alicyclic heterocycle, for example, a 5- or 6-membered monocyclic alicyclic heterocycle containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and a 3- to 8-membered ring are condensed. A bicyclic or tricyclic condensed alicyclic heterocyclic ring containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom, and more specifically, a pyrrolidine ring, a piperidine ring, Examples include piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetrahydroisoquinoline ring, tetrahydrofuran ring, tetrahydropyran ring, dihydrobenzofuran ring, tetrahydrocarbazole ring and the like.

  Examples of the aromatic ring or condensed ring constituting ring B include those having 6 to 14 carbon atoms, such as a benzene ring, a naphthalene ring, and an anthracene ring.

  The substituent of the heterocyclic ring or aromatic ring may be the same or different and may be 1 to 5 substituents such as hydroxyl group, carboxyl group, nitro group, alkoxy group, alkyloxycarbonyl group, amide group, sulfonamide group, alkyl Group, aralkyl group, cyano group, halogen atom, -R '= R "-Ar (R' and R" are the same and represent N or CH, Ar represents a hydroxyl group, a carboxyl group, a nitro group, an alkoxy group And an aryl group which may be substituted with a substituent selected from the group consisting of an alkyl group optionally substituted with a halogen group, a cyano group and a halogen atom). Examples of the substituent of the alkyl group or the alkoxy group include the same or different 1 to 3 substituents such as a hydroxyl group, a carboxyl group, a nitro group, an alkoxy group, an aryl group, and a halogen atom. Among them, a 5-membered or 6-membered heterocyclic ring which may have a substituent or a 5-membered or 6-membered aromatic ring which may have a substituent is preferable.

  (1a) In formula, n is an integer of 0-6, Preferably it is an integer of 0-5, More preferably, it is an integer of 0-3, More preferably, it is an integer of 0-2. When n is 1 or more, the hydrogen atom bonded to the carbon atom constituting the ring A is substituted with Y.

Examples of the organic group as X and Y include, for example, alkyl group, alkoxy group, alkylthiooxy group (alkylthio group), alkyloxycarbonyl group, alkylsulfonyl group, aryl group, aralkyl group, aryloxy group, arylthiooxy group (an arylthio group), an aryloxycarbonyl group, an arylsulfonyl group, an arylsulfinyl group, an amide group (-NHCOR), a sulfonamido group (-NHSO ₂ R), a carboxy group (carboxylic acid group), benzothiazole group, halogenoalkyl Group, cyano group and the like. Examples of the polar functional group include a halogeno group, a hydroxyl group, a nitro group, an amino group, and a sulfo group (sulfonic acid group).

  As the organic group or polar functional group as an example of X, among the above, an alkyl group, an alkyloxycarbonyl group, and an aryl group are preferable, and an alkyl group or an aryl group is more preferable. In this case, the number of carbon atoms of the alkyl group is preferably 1 to 6 if it is a linear or branched alkyl group, more preferably 1 to 4, and 4 to 7 if it is an alicyclic alkyl group. Preferably, it is 5-6. 6-10 are preferable and, as for carbon number of an aryl group, More preferably, it is 6-8. Specific examples include a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, a cyclohexyl group, and a phenyl group.

  As the organic group or polar functional group as an example of Y, among the above, an alkyl group, an alkoxy group, a halogeno group, a phenyl group, an alkoxycarbonyl group (ester group), an amide group, a sulfonamide group, and a hydroxyl group are preferable. An alkyl group or a hydroxyl group is preferable. In this case, 1-5 are preferable, as for carbon number of an alkyl group, More preferably, it is 1-3, More preferably, it is 1-2. Specifically, preferred examples of the organic group or polar functional group as Y include a methyl group, an ethyl group, and a hydroxyl group. When n is 2 or more, each Y may be the same or different.

In the formula (2a), R ¹ , R ² , R ⁴ and R ⁵ are each independently an organic group, a polar functional group or a hydrogen atom, and R ³ is an organic group or a polar functional group containing a nitrogen atom. , R ¹ and R ⁵ are at least one of an organic group or a polar functional group containing a nitrogen atom or an oxygen atom. In addition, * represents the coupling | bond part with the 4-membered ring in (1) Formula or the 5-membered ring in (2) Formula.

  A particularly preferred squarylium-based compound is that in the structural unit of formula (1), ring A is cyclohexene, cycloheptene, or cyclooctene, X is an alkyl group having 1 to 4 carbon atoms, and ring B is a benzene ring or naphthalene ring. It is a compound which is. In the particularly preferred squarylium compound, when ring B has a substituent, the substituent is preferably an alkyl group, a trihalogenomethyl group, a phenyl group, an alkoxy group, a cyano group, a carboxyl group, or a halogeno group.

The oxocarbon-based compound having the above-described configuration can be synthesized, for example, by the synthesis method described in the following paper.
SAJJADIFAR ET AL: 'New 3H-Indole Synthesis by Fischer's Method. Part I.' Molecules 2010, No. 15, April 2010, pages 2491-2498
Serguei Miltsov ET AL; 'New Cyanine Dyes: Norindosquarocyanines', Tetrahedron Letters, Volume 40, Issue 21, May 1999, pages 4067-4068

  In addition to the above paper, examples of the synthesis method for reacting a pyrrole ring-containing compound with croconic acid include, for example, JP-A No. 2002-286931, JP-A No. 2007-31644, JP-A No. 2007-31645, and JP-A No. 2007. Reference may be made to the method described in JP-A 169315.

  In addition to the above oxirane ring-containing compounds, as the light selective absorber, phthalocyanine dyes, cyanine dyes, porphyrin dyes, pyromethene dyes, azo dyes, quinone dyes, squarylium dyes, triarylmethane dyes Further, near-infrared absorbing compounds such as indigo dyes, copper ion dyes, and diimonium dyes may be used in combination.

  Such a light selective absorbent is preferably 50 parts by mass or less, more preferably 20 parts by mass or less, from the viewpoint of solubility in a solvent per 100 parts by mass of the base resin. From the viewpoint of the amount of dye absorbed, it is preferably 1 part by mass or more, more preferably 3 parts by mass or more.

(1-3) Curing Agent When the resin composition used in the present invention is a curable resin composition, it preferably contains a curing agent that accelerates the curing reaction of the curable resin. The curing agent is appropriately selected depending on the type of curable resin.

  When an acrylic resin is contained as a curable resin, radical polymerization can generate radicals by heating or light irradiation and initiate polymerization of vinyl groups such as (meth) acryloyl groups in curable (meth) acrylic resins. An initiator can be used.

  When an epoxy resin is used as the curable resin, an acid anhydride, an amine, a phosphine phenol (including a phenol resin), or a thiol can be used as the curing agent.

  The acid anhydride is preferably an alicyclic carboxylic acid anhydride, more preferably methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, more preferably Methylhexahydrophthalic anhydride and hexahydrophthalic anhydride.

  In the case of a cationic curable resin, it is preferable to use a combination of Lewis acid and Lewis base as the cationic curing catalyst.

  Specific examples of the Lewis acid include tris (pentafluorophenyl) borane (TPB), bis (pentafluorophenyl) phenylborane, pentafluorophenyl-diphenylborane, and tris (4-fluorophenyl) borane. TPB is more preferable because it can improve the heat resistance, moisture heat resistance, low water absorption, UV irradiation resistance and the like of the molded body.

The Lewis base is not particularly limited as long as it can be coordinated to the Lewis acid, that is, can form a coordinate bond with the boron atom of the Lewis acid. A compound having a sulfur atom can be used.
Preferred examples of the compound having a nitrogen atom include amines (monoamines and polyamines) and ammonia. More preferred are amines having a hindered amine structure, low boiling point amines, and ammonia. The compound having the phosphorus atom is preferably a phosphine. Specific examples include triphenylphosphine, trimethylphosphine, tritoluylphosphine, methyldiphenylphosphine, 1,2-bis (diphenylphosphino) ethane, and diphenylphosphine.
Preferred examples of the compound having a sulfur atom include thiols and sulfides. Specific examples of thiols include methyl thiol, ethyl thiol, propyl thiol, hexyl thiol, decane thiol, and phenyl thiol. Specific examples of the sulfides include diphenyl sulfide, dimethyl sulfide, diethyl sulfide, methylphenyl sulfide, methoxymethylphenyl sulfide and the like.

  The content of the curing agent is appropriately selected according to the type of base resin and the type of curing agent. When the base resin is an epoxy resin and a combination of Lewis acid and Lewis base is used as the cationic curing agent, the cationic curing agent is preferably contained in an amount of 0.1 to 10 parts by mass, more preferably 100 parts by mass of the base resin. It is 0.5-8 mass parts, More preferably, it is 1-5 mass parts.

(1-4) Silane coupling agent It is preferable that the resin composition used as the material of the light selective absorption resin film contains a silane coupling agent. When a resin composition in which an oxirane ring-containing compound is combined with an oxocarbon-based compound is used, it is difficult to produce a cured product excellent in both photoselective permeability and heat-and-moisture resistance of the resin composition, but a silane coupling agent By containing, it can be set as the hardened | cured material which was excellent in both selective permeability and heat-and-moisture resistance, and also adhesiveness (especially adhesiveness to a glass substrate) can be improved.

  Examples of the silane coupling agent include mercapto group-containing silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane; 3-aminopropyltrimethoxysilane, Amino group-containing silane coupling agents such as 3-aminopropyltriethoxysilane and 3-aminopropyltriisopropoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- Epoxy ring-containing silane coupling agents such as (2,3-epoxycyclohexyl) propyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxy And unsaturated hydrocarbon group-containing silane coupling agents such as methyl dimethoxy silane can be used. Of these, an epoxy ring-containing silane coupling agent is particularly preferably used.

  The content of the silane coupling agent in the resin composition is preferably 0.001 part by mass or more, more preferably 0.1 part by mass or more, with respect to 100 parts by mass of the base resin, from the viewpoint of imparting adhesion. Part or more is more preferable.

(1-5) Mercapto group-containing compound The resin composition used in the present invention preferably further contains a mercapto group-containing compound. When using a resin composition that combines an oxocarbon-based compound and a curing catalyst, it is difficult to produce a cured product with sufficiently excellent selective permeability of the resin composition, but a combination of an oxocarbon-based compound and a curing catalyst. By including a mercapto group-containing compound in the resin composition, it is possible to obtain a cured product having sufficiently excellent selective permeability, and to further improve adhesiveness (particularly adhesion to a glass substrate). . That is, it can be used as a visible light transmittance improver. Moreover, it is thought that the production | generation of the coloring component which has absorption in a visible region is suppressed by containing a mercapto group containing compound in a resin composition.

  The mercapto group-containing compound may be a compound containing one or more mercapto groups in the compound, but is preferably a compound containing 2 to 6, more preferably 3 to 5. For example, β-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, methoxybutyl-3-methcaptopropionate, stearyl-3-mercaptopropio , Trimethylolpropane tris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] isocyanurate, pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol bis (3- Β-mercaptopropionic acids such as mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), and dipentaerythritol hexakis (3-mercaptopropionate) can be used. Among these, tris-[(3-mercaptopropionyloxy) -ethyl] isocyanurate (TEMPIC), pentaerythritol tetrakis (3-mercaptoprepionate) (PEMP), dipentaerythritol hexakis (3-mercaptopropionate) ) (DPMP) is preferred, and pentaerythritol tetrakis (3-mercaptoprepionate) (PEMP) is more preferred.

Moreover, you may use the mercapto group containing silane coupling agent represented by a following formula as a mercapto group containing compound.
HS-R-Si (OR ') _n (R ") _3-n
R is an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms. R ′ is an alkyl group, an acetyl group, or a methoxyalkyl group, preferably a methyl group or an ethyl group, and more preferably a methyl group. R ″ is an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. N is 1 or more and 3 or less, preferably 3. A mercapto group-containing silane cup Specific examples of the ring agent include mercapto group-containing silane coupling agents exemplified for the silane coupling agent.

  The content of the mercapto group-containing compound per 100 parts by mass of the base resin is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass.

(1-6) Surface Conditioner The resin composition may further contain a surface conditioner. By containing the surface conditioner, defects such as dents and striations in the formed resin film can be suppressed, and the homogeneity of the resin film surface can be improved.

  The surface conditioner is not particularly limited, and examples thereof include a siloxane-based surfactant, an acetylene glycol-based surfactant, a fluorine-based surfactant, and an acrylic leveling agent. A siloxane surfactant or an acrylic leveling agent is preferable, and a siloxane surfactant is more preferable.

  A siloxane-based surfactant is a surfactant having a siloxane bond (—Si—O—Si—), such as polyether-modified polydimethylsiloxane, alkyl-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, Examples include aralkyl-modified polydimethylsiloxane, and from the viewpoint of dispersibility of the oxocarbon-based compound in the resin composition, it is preferable that polyether-modified polydimethylsiloxane is included. The polyether-modified polydimethylsiloxane is preferably a nonionic surfactant having a hydrophilic group composed of polyalkylene oxide (more preferably ethylene oxide or propylene oxide) and a hydrophobic group composed of dimethylsiloxane.

  A commercially available product can also be used as the polyether-modified polydimethylsiloxane. Examples of commercially available products include BYK-306, BYK-307, BYK-330, BYK-331, BYK-337, BYK-344 (above, manufactured by BYK Chemie), KF-618, KF-351, KF-352, Examples thereof include KF-353, KF-6011, KF-6015 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, 5-dimethyl-1-hexyn-3-ol and the like.

  Examples of the fluorosurfactant include perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and perfluoroalkylamine oxide compounds. Etc.

  Examples of the acrylic leveling agent include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl. A polymer obtained by polymerizing acrylate, sec-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl metallate, etc. Or a copolymer obtained by copolymerizing two or more types Door can be.

  The content of the surface conditioner per 100 parts by mass of the base resin is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass.

(1-7) Other components The resin composition used in the present invention is a curing catalyst / curing agent other than the cationic curing catalyst, a curing accelerator, a reaction, as long as the effects of the present invention are not impaired. Diluent, saturated compound without unsaturated bond, pigment, dye, antioxidant, ultraviolet absorber, light stabilizer, plasticizer, non-reactive compound, chain transfer agent, thermal polymerization initiator, anaerobic polymerization initiation Agents, polymerization inhibitors, inorganic fillers, organic fillers, adhesion improvers such as coupling agents other than silane coupling agents, heat stabilizers, antibacterial / antifungal agents, flame retardants, matting agents, antifoaming agents , Leveling agents, wetting / dispersing agents, anti-settling agents, thickeners / anti-sagging agents, anti-coloring agents, emulsifiers, anti-slip / scratch agents, anti-skinning agents, desiccants, antifouling agents, antistatic agents, You may contain a electrically conductive agent (electrostatic adjuvant) etc.

(2) Solvent The solvent for dissolving the resin composition as described above is an organic solvent that can dissolve the base resin and the photoselective absorber, and may be one kind of organic solvent, or two or more kinds. It may be a mixture of organic solvents.

  The amount of the solvent in the resin solution is preferably 10% by mass or more, more preferably 30% by mass or more, and particularly preferably 50% by mass or more from the viewpoint of dissolving the material and spreading a uniform coating film during spin coating. For the same reason, the resin solid content in the resin solution is preferably less than 90% by mass, more preferably less than 70% by mass, and particularly preferably less than 50% by mass. The amount of the solvent in the resin solution is preferably less than 95% by mass from the viewpoint of film formation in a single hour and securing the coating film thickness. Less than 90% by weight is more preferred, and less than 80% by weight is particularly preferred. For the same reason, the resin solid content in the resin solution is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more.

  Usable organic solvents include, for example, toluene, xylene, benzene, ethylbenzene, tetralin, styrene, cyclohexane, dichloromethane, chloroform, ethyl chloride, 1,1,1-trichloroethane, 1-chlorobutane, cyclohexyl chloride, trans-dichloroethylene, Cyclohexanol, methyl cellosolve, n-propanol, n-butanol, 2-ethylbutanol, n-heptanol, 2-ethylhexanol, butoxyethanol, diacetone alcohol, benzaldehyde, γ-butyrolactone, acetone, methyl ethyl ketone, dibutyl ketone, methyl- i-butyl ketone, methyl-i-amyl ketone, cyclohexane, acetophenone, methylal, furan, β-β-dichloroethyl ether Dioxane, tetrahydrofuran, ethyl acetate, n-butyl acetate, amyl acetate, n-butyl acetate, cyclohexylamine, ethanolamine, dimethylformamide, acetonitrile, nitromethane, nitroethane, 2-nitropropane, nitrobenzene, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol Examples thereof include monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monomethyl ether acetate, cyclohexanone, N-methylpyrrolidone and the like.

  These solvents are used alone or as a mixture of two or more kinds within a range that satisfies the following requirements. As will be described later, in the forming method of the present invention, the spin time of the spin coating process is shorter than that of the conventional method in order to uniformly coat the substrate. For this reason, it is desired that the resin film be a solvent that can be dried in this time. “Dry” as used herein refers to a state of being hardened to such an extent that it does not flow, and includes a case where some solvent remains in the resin film.

As specific requirements, it is preferable that the following solvents are contained in an amount of 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% or more by total solvent. The vapor pressure at 20 ° C. is preferably 0.1 kPa or more, more preferably 0.5 kPa or more, and particularly preferably 1 kPa or more. The lower limit of the vapor pressure at 20 ° C. is preferably less than 30 kPa, more preferably 10 kPa or less, and particularly preferably 5 kPa or less. Moreover, it is preferable that it is 50 degreeC or more of boiling points, More preferably, it is 100 degreeC or more. The lower limit of the boiling point is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and particularly preferably 150 ° C. or lower.
When the vapor pressure is less than 0.1 kPa or the boiling point is 50 ° C. or higher, the solvent is not sufficiently evaporated until the rotation is stopped, and the formed resin film still maintains the fluidity. If it is in a state having fluidity even after the rotation is stopped, it is necessary to perform a separate drying step until the next post-curing step is performed, which is not preferable from the viewpoint of production efficiency. Further, the homogeneity of the resin film may change due to the flow after the rotation is stopped.

  On the other hand, if the vapor pressure at 20 ° C. exceeds 30 kPa or the boiling point is less than 50 ° C., the solvent evaporates and volatilizes too quickly, evaporating during dropping, and sufficient fluidity may not be ensured during rotation. In this case, the spin coating does not sufficiently diffuse and cast on the substrate, and as a result, the uniformity of the film decreases, the resin solid content concentration during rotation becomes too high, and a thin film cannot be formed. There is.

  Examples of the solvent that can satisfy the above conditions include, for example, toluene, xylene, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and cyclohexanone as a single organic solvent. Examples include a combination of toluene and xylene, a combination of cyclohexane and xylene, and the like.

  When the organic solvent remains in the light selective absorption resin film, the residual solvent may affect the light absorption. Also from this point, it is preferable that the solvent is completely removed at the end of the production process. In the case of a thermosetting resin solution, the solvent can be evaporated in the heat curing step performed after the spin coating step, but as will be described later, the heating step is often performed with the substrate standing vertically. For this reason, it is preferable that the resin film is in a dry state when it is subjected to the heat curing step.

[Solidification process]
After spin coating, the resin film is solidified. A solidification process is suitably selected according to the kind of resin composition, especially the kind of base resin.
The solidification step is a cooling step when a thermoplastic resin is used as the base resin, a light irradiation step when a photocurable resin is used, and a heat curing step when a thermosetting resin is used. .

Before such a solidification step, a drying step for completely removing the solvent may be performed as necessary.
Examples of the drying step include standing at a temperature at which the solvent can be evaporated and heating. When the thermosetting resin composition is used, the solvent can be completely evaporated in the heat curing step, so that the drying step does not have to be performed.

Hereinafter, the solidification process in the case of using a cationic curable resin composition which is a preferable resin composition, that is, a heat curing process will be described.
The heat curing conditions are appropriately set according to the composition of the resin composition to be used.
In the case of a combination of an epoxy resin and a curing agent, it is kept at 80 to 300 ° C., preferably 100 to 250 ° C. for about 30 minutes to 2 hours to completely cure and completely evaporate the solvent.

The heat curing step is performed by leaving it in a heating oven.
It is preferable from the viewpoint of production efficiency that a plurality of the produced resin film laminated substrates are collectively heat-cured. It is preferable that the substrate is left standing in an oven with the substrate standing vertically. From the viewpoint of preventing impurities and foreign matters such as dust and dust from adhering to the formed coating film, it is preferable to perform heat curing in a vertically standing state.
In view of performing the heat curing step in a vertically standing state, it is preferable that the resin film is dried, that is, in a state having no fluidity before being put in the oven.

The heat curing step is preferably performed in an inert gas atmosphere such as nitrogen, and more preferably, a nitrogen stream is introduced into the system or gas replacement in the oven is performed with an inert gas, followed by heat curing. It is preferable.
Thereby, modification | denaturation of the light selective absorber in a heat-hardening process can be prevented.

[Light selective absorption resin film]
The thickness of the light selective absorption resin film formed as described above varies depending on the type of optical filter, the composition of the resin composition used, the dye, the substrate, and the like, but is usually 0.1 to 20 μm, preferably 0.5. 10 μm, more preferably 1 to 5 μm.
And the formed light selective absorption resin film is excellent in film thickness uniformity. Specifically, the ratio between the maximum film thickness and the minimum film thickness is less than ± 10%, preferably less than 6%, with respect to the total film thickness.

The transmittance spectrum of a light selective absorption film containing a light selective absorber that absorbs light of a specific wavelength generally depends on the film thickness. For example, as shown in FIG. 2, when the light selective absorption resin layer having a certain film thickness is formed as an infrared cut filter, the spectrum is a solid line (50% transmittance wavelength T ₁ = 645 nm). The transmittance drops to a spectrum as shown by a broken line. As a result, in the thick light selective absorption resin film part such as the four corners, the 50% transmittance wavelength (T ₂ ) in the visible light wavelength region (500 to 700 nm) is shifted to the short wavelength side, and the transmitted color changes. To do. In addition, when it becomes too thin, there is a possibility that not only the change of the transmitted color but also the cut of the light in the infrared absorption region wavelength will be insufficient.

  In the light selective absorption resin film produced by the forming method of the present invention, the uniformity of the film thickness is high even for a rectangular substrate. Therefore, the variation deviation of the 50% transmittance wavelength in the light selective absorption film (maximum wavelength and Difference in the minimum wavelength) can be suppressed to 10 nm or less, preferably 8 nm or less, more preferably 5 nm or less, and further preferably 4 nm or less. Specifically, when a square substrate is divided into squares of about 3 mm × 3 mm to 8 mm × 8 mm and a transmittance spectrum of a circular region having a center of 2 mm is obtained, a square at the center of the substrate and a square at the corner are obtained. 50% transmittance wavelength difference can be suppressed to 10 nm or less, preferably 8 nm or less, more preferably 5 nm or less, and even more preferably 4 nm or less. In other words, it is possible to suppress variations and deviations in transmittance within the above range except for a region of 1 mm or less, preferably 0.5 mm or less, more preferably 0.3 mm or less from the edge.

  Furthermore, according to the method for forming a light selective absorption resin film of the present invention, the spin coating method is characterized by high speed rotation and a short time of spin coating, so that the spin coating method does not increase the disposal of the resin material. Also, the productivity of film formation is high.

[Use]
The light selective absorption resin film formed as described above can be used as a light selective absorption resin film of an optical filter or a light selective absorption coat of an optical member, depending on the type of substrate.

  When a glass substrate or a transparent resin substrate having a thickness of 1 mm or less is used as the substrate, an optical filter can be obtained by laminating a light selective absorption resin film. The optical filter that can be manufactured by applying the forming method of the present invention has various functions that selectively extract (pass) or cut a part of incident light according to the type of substrate and the type of light selective absorber. The optical filter can be obtained.

Specifically, a bandpass filter having a function of transmitting only a specific wavelength; a color filter having a function of absorbing a certain band and transmitting the other band with respect to the visible spectrum (400 to 700 nm); A dichroic filter that has a function of reflecting the band and transmitting the other band; a neutral density filter (ND) filter that averagely attenuates light of all wavelengths in the visible light region; a wavelength that blocks transmission Long pass filter or short pass filter having both a band and a pass band which is a transmission wavelength band; a cut filter and the like.
In particular, an infrared cut filter, an ultraviolet cut filter, and a near infrared cut filter are suitable, and a near infrared or infrared cut filter is preferable.

  When an optical filter is manufactured by applying the formation of the light selective absorption resin film of the present invention, after the light selective absorption resin film is formed, the side on which the light selective resin film of the base material is not laminated. A vapor deposited film of a dielectric inorganic material may be laminated on this surface. The vapor deposition film is not limited to one layer but may be a multilayer film. Depending on the kind of inorganic material to be deposited, the layer structure, and the number of layers, a functional film such as a reflection film or an antireflection film can be obtained.

  As the reflection film (or antireflection film), it is preferable to use a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately laminated. As a material constituting the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index range of 1.7 to 2.5 is usually selected. Examples of the material constituting the high refractive index material layer include oxides such as titanium oxide, zinc oxide, zirconium oxide, lanthanum oxide, yttrium oxide, indium oxide, niobium oxide, tantalum oxide, tin oxide, and bismuth oxide; silicon nitride Nitrides such as oxides, mixtures of the nitrides and the like, and those doped with metals or carbon such as aluminum or copper (for example, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO)), etc. Can be mentioned. As a material constituting the low refractive index material layer, a material having a refractive index of 1.6 or less can be used, and a material having a refractive index range of 1.2 to 1.6 is usually selected. Examples of the material constituting the low refractive index material layer include silicon dioxide (silica), alumina, lanthanum fluoride, magnesium fluoride, and aluminum hexafluoride sodium. By adjusting the kind, number of layers, and film thickness of these low refractive materials and high refractive materials, a reflective film (or antireflection film) can be obtained.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples.

[Evaluation method of film thickness uniformity]
A vertical side and a horizontal side of a 76 mm × 76 mm glass substrate were each divided at intervals of 7.6 mm and divided into 100 squares. For each mass, the transmittance spectrum of each mass is measured using a UV-VIS spectrophotometer (Agilent 8453, manufactured by Agilent Technologies), and the wavelength when the transmittance at 600 nm to 700 nm is 50% is determined. It was.
Based on the photoselective absorber used, the film was formed so that the 50% transmittance wavelength was around 645 nm. Obtain the average value of the 50% transmittance wavelength of the entire resin film laminated substrate (100 squares), the variation range of the 50% transmittance wavelength of 100 squares, and the deviation (difference between the maximum value and the minimum value of 50% transmittance). It was.
In addition, the measurement of the transmittance | permeability of each mass measured the transmittance | permeability in the circular area | region of diameter 2mm of the center of each mass.

(Preparation of resin composition)
(1) Cationic curing catalyst (1-1) TPB-containing powder (Lewis acid)
In accordance with a synthesis method described in WO1997 / 031924, 255 g of Isopar (registered trademark) E solution manufactured by Ando Parachemi with a TPB (tris (pentafluorophenyl) borane) content of 7% was prepared.
When water was dropped into the Isopar E solution at 60 ° C., white crystals were precipitated from the middle of dropping. After cooling the reaction solution to room temperature, the resulting slurry was filtered with suction and washed with n-heptane. The obtained cake was dried at 60 ° C. under reduced pressure, and 18.7 g of TPB / water complex (TPB-containing powder) as white crystals was obtained. This complex had a water content of 9.2% (Karl Fischer moisture meter) and a TPB content of 90.8%.
The complex after drying was subjected to ¹⁹ F-NMR analysis and GC analysis, but no peak was detected other than TPB. The results of ¹⁹ F-NMR analysis are as follows.

¹⁹ F-NMR (CDCl ₃ ) ppm (standard substance CFCCl ₃ 0 ppm)
δ = −135.6 (6F, m)
δ = -156.5 (3F, dd)
δ = −163.5 (6F, d)

(1-2) Preparation of Cationic Curing Catalyst A combination of the above TPB-containing powder (Lewis acid) and ammonia as a Lewis base was mixed as follows to prepare a cationic curing catalyst.
To 2 g of TPB-containing powder (TPB pure content: 1.816 g (3.547 mol) and water 0.184 g (10.211 mmol), 1.1 g of toluene was added and mixed at room temperature for 10 minutes.
To the obtained toluene solution of TPB, 2.6 g of a 2 mol / L ammonia / ethanol solution was added and mixed at room temperature for 60 minutes. The obtained homogeneous solution was used as a cationic curing catalyst.

上記スクアリリウム化合物は、ピロール環含有化合物とスクアリン酸とを反応させる公知の合成方（例えば、すでに述べた論文に記載の方法）によって合成することができる。 (2) Near-infrared absorber As a near-infrared absorber, the squarylium compound which has a structure of following (3) Formula was used. The maximum absorption wavelength of this squarylium compound is 730 nm.

The squarylium compound can be synthesized by a known synthesis method in which a pyrrole ring-containing compound and squaric acid are reacted (for example, the method described in the paper already described).

(3) Silane coupling agent solution 4 parts of silane coupling agent (ofs-6040 (3-glycidoxypropyltrimethoxysilane which is conventional Z-6040) of Toray Dow Corning), 2-propanol (Wako Pure Chemical Industries, Ltd.) (Made) 5.2 parts, pure water (made by Wako Purechemical) 0.6 part, and formic acid 0.2 part were mixed for 90 minutes at 25 degreeC, and the uniform solution of the silane coupling agent was obtained.

(4) Preparation of Resin Solution for Coating As the base resin, an alicyclic epoxy resin (EHPE3150) manufactured by Daicel, which is an oxirane compound, was used. 100 parts of base resin was mixed with 150 parts of toluene (manufactured by Wako Pure Chemical Industries, Ltd.) and 75 parts of o-xylene at 80 ° C.
In this resin solution, 9 parts of the squarylium compound synthesized above, 0.4 part of BYK-306 (polyether-modified polydimethylsiloxane) manufactured by Big Chemie as a surface conditioner, and PEMP manufactured by SC Organic Chemical Co., Ltd. as a transmittance improver 10 parts of pentaerythritol tetrakis (3-mercaptopropionate), see formula below was added and mixed at 25 ° C. for 60 minutes to obtain a uniform solution. To this solution, 2.5 parts of the cation curing catalyst prepared above was added and then mixed at 25 ° C. for 5 minutes. Furthermore, 10 parts of the silane coupling agent solution prepared above was mixed at 25 ° C. for 30 minutes. The obtained uniform solution was filtered through a PTFE filter having a pore size of 0.1 μm (manufactured by GE Helthcare, Whatman 6784-2501) to remove foreign matters.

[Manufacture of optical filters]
Example 1:
As a coating apparatus, a spin coater (MS-A200 manufactured by Mikasa Corporation) was used.
After 1 g of the resin solution prepared above was dropped on a 76 mm × 76 mm glass substrate, the resin solution was accelerated to 1800 rpm in 0.1 seconds, maintained at 1800 rpm for 1 second, then stopped in 0.1 second, and rotated. Applied.

  The formed glass substrate is placed in an inert oven (CL0-9CH manufactured by Koyo Thermo Systems Co., Ltd.), and the inside of the oven is purged with nitrogen at room temperature for 30 minutes (oxygen concentration less than 100 ppm), and then heated to 200 ° C. in 30 minutes. The temperature was maintained. After holding at 200 ° C. for 30 hours, the temperature was lowered to 150 ° C. in 30 minutes, and the light selective absorption resin film laminated substrate was taken out. The thickness of the light selective absorption resin film in the thus obtained light selective absorption resin film laminated substrate was 2 μm.

About the light selective absorption resin film | membrane laminated substrate obtained in this way, the transmittance | permeability spectrum of each 100 mass was obtained using the UV-VIS spectrophotometer (Agilent 8453, product made by Agilent Technology). Furthermore, the 50% transmittance wavelength of each mass was determined.
Moreover, based on the said evaluation method, the average value of 50% transmittance | permeability wavelength of 100 squares and the deviation of 50% transmittance | permeability wavelength were computed.

Comparative Example 1:
A resin laminated substrate on which a light selective absorption resin film was formed by forming a film on a glass substrate and drying and curing in the same manner as in Example 1 except that the spin coating conditions were changed as follows. The transmittance spectrum of 100 squares was obtained, and the 50% transmittance wavelength of each square was obtained.
Spin coating conditions Accelerated to 1300 rpm in 0.5 seconds, maintained at 1300 rpm for 20 seconds, and then returned to 0 rpm in 0.1 seconds.

  About the resin laminated substrate of the created Example and Comparative Example, the average value (nm) of 50% transmittance wavelength, 50% transmittance wavelength (nm) at four corners, and deviation (nm) of transmittance wavelength are summarized. Table 1 shows. Also, among the transmittance spectra obtained for each square, the mass spectrum at the center of the substrate, and the transmittance spectrum of the mass at which the 50% transmittance wavelength shows the maximum and minimum values at the four corners are shown in FIG. Example 1) and FIG. 4 (Comparative Example 1) are shown.

  As can be seen from Table 1 and FIG. 3, in the formation method of the embodiment in which the acceleration time up to the maximum rotation speed and the duration of the maximum rotation speed were shortened, the difference in the 50% transmittance wavelength between the center position and the four corners is It can be seen that a light selective absorption resin film having a high homogeneity can be formed on the entire rectangular substrate as small as 4 nm. In FIG. 3, the transmittance spectrum at the center of the substrate and the transmittance spectrum at the four corners almost coincided.

  On the other hand, in the formation method of the comparative example in which the acceleration time to the high speed rotation speed is 0.5 seconds and the duration time of the maximum rotation speed is 20 seconds, the average value of 50% transmittance is 646.5 nm. However, it was recognized that the four corners shifted to less than 630 nm such as 627 nm and 630 nm, and the film thickness was increased at the four corners. Specifically, as shown in FIG. 4, the transmittance spectrum (dashed line) at the corner where the 50% transmittance shows the minimum value with respect to the transmittance spectrum (solid line) at the center of the substrate is totally transmitted. The rate was falling. The deviation of the 50% transmittance wavelength is as large as 22 nm, indicating that a light selective absorption resin film having poor uniformity was formed.

Example 2
An alternating vapor deposition film (infrared reflective film) of 25 layers of titanium oxide / 26 layers of silica was formed on the surface opposite to the side on which the resin film of the light selective absorption resin film laminate obtained in Example 1 was formed. Then, an alternate vapor deposition film (a visible light antireflection film) of titanium oxide 2 layers / silica 3 layers was formed on the resin film. Thereby, a good infrared reflection absorption type infrared cut filter for an imaging device was obtained.

  According to the method for forming a light selective absorption resin film of the present invention, it is possible to form a light selective absorption resin film having a film homogeneity and, therefore, excellent light selective absorption / transmission characteristics even for a rectangular substrate. Therefore, by applying the method for forming a light selective absorption resin film of the present invention, a rectangular optical filter can be efficiently manufactured.

1 Square substrate 2 Top plate 3 Resin solution 6 Droplet prevention plate

Claims (15)

A method of forming a resin film (light selective absorption resin film) having a light selective absorption function on a square substrate by a spin coating method in which a resin solution that is a material of the resin film is dropped.
A method for forming a light selective absorption resin film, wherein an acceleration time to a maximum rotation speed is less than 2 seconds and a duration time of the maximum rotation speed is less than 5 seconds.   The forming method according to claim 1, wherein the maximum rotational speed is 1000 rpm or more, the acceleration time is less than 0.5 seconds, and the duration is less than 3 seconds.   The forming method according to claim 1, wherein the rotational speed is 1500 rpm or more, the acceleration time is less than 0.2 seconds, and the duration time is less than 3 seconds.   The said spin coat process is a formation method of any one of Claims 1-3 performed by the open system which can volatilize the solvent of the said resin solution.   The forming method according to claim 4, wherein the spin coating step is performed in a state where a top plate to which droplets can adhere is provided above a surface of the substrate on which the resin film is formed. In the spin coating step, a droplet adhesion preventing plate having a size larger than that of the substrate is provided on the opposite side of the surface of the substrate on which the resin film is formed,
The formation method according to claim 4 or 5, wherein a distance between the substrate and the droplet adhesion preventing plate is less than 1 mm.   The forming method according to claim 1, wherein the resin solution is a resin solution containing 10% or more of an organic solvent having a vapor pressure of 1 kPa or more at 20 ° C. or more.   The forming method according to claim 1, wherein a solid content ratio in the resin solution is 5 to 50% by mass.   The forming method according to claim 1, wherein the resin solution is a solution obtained by dissolving a cationic curable resin composition with the solvent.   The forming method according to claim 1, wherein the resin solution contains a light selective absorbent.   The forming method according to claim 1, wherein the resin solution has a viscosity of 0.1 to 100 mPa · s.   The formation method according to claim 1, wherein the substrate is a square having at least one side of 30 mm to 120 mm.   The forming method according to claim 1, wherein the resin solution has no fluidity after the spin coating process.   The manufacturing method of the cut filter containing the formation method of any one of Claims 1-13. An infrared or near-infrared cut filter in which a light selective absorption resin film is laminated on a square substrate,
The light selective absorption resin film is a cured product obtained by curing an epoxy resin with a cationic curing catalyst, and includes an oxirane ring-containing compound as a light selective absorber.
An infrared or near-infrared cut filter in which the transmittance wavelength deviation of the light selective absorption resin film is 10 nm or less as a wavelength at which the transmittance of light in the visible light wavelength region of 600 to 700 nm is 50%.

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