JP6961470B2 - Liquid discharge head and its manufacturing method - Google Patents

Description

The present invention relates to a liquid discharge head having improved durability and a method for manufacturing the same.

The liquid discharge head is used for recording with ink on a recording medium by an inkjet recording method, applying a liquid for surface treatment to a surface to be treated, and the like. An inkjet recording head applied to an inkjet recording method in which ink is ejected onto a recording medium for recording generally provides energy for ejecting ink from a fine ejection port, a flow path communicating with the ejection port, and the ejection port. It is equipped with a plurality of energy generating elements to generate.
Patent Document 1 discloses an inkjet print head having such a configuration. Patent Document 1 discloses photosensitive polyimide (Polyimide), photosensitive polyamide (Polyamide), and photosensitive epoxy (Epoxy) as materials for a flow path forming member.
On the other hand, Patent Document 2 describes a cured product of a resin composition containing a curable epoxy compound, a compound having fluorocarbon, and a curing agent as a material for forming a component of a liquid discharge head including a flow path forming member. It is disclosed. Patent Document 2 describes that a liquid discharge head capable of stable discharge over a long period of time can be provided by using a cured product of this resin composition as a constituent material of the liquid discharge head.

Japanese Unexamined Patent Publication No. 2009-1003 U.S. Pat. No. 7,055,938

As ink for inkjet, a wide variety of inks are known, such as water-based ink as a general-purpose product in general households and pigment ink for forming durable and robust commercial printed matter. Further, for inkjet, there is known an ink in which the content of an organic solvent is higher than that of a water-based ink as a general-purpose product in general households in order to obtain a desired function. There is a demand for a liquid ejection head that has durability and can stably maintain its performance even when an ink having a high content of such an organic solvent is used.
However, in the flow path forming member disclosed in Patent Document 1, when an ink containing a large amount of an organic solvent component is used, the ink ejection amount fluctuates due to the swelling of the flow path forming member and the like, resulting in printed matter. Problems may occur.
Patent Document 2 uses a resin composition for a flow path forming member in which a compound having fluorocarbon is combined with an epoxy compound, and the cured product has a high crosslink density and is excellent in ink resistance and mechanical strength. Therefore, in the liquid discharge head in which the flow path forming member is formed from the cured product of the resin composition disclosed in Patent Document 2, the occurrence of swelling of the above-mentioned flow path forming member is suppressed, and stable recording can be achieved for a long period of time. It will be possible.
An object of the present invention is to provide a liquid ejection head and a method for manufacturing the same, which can be applied to a liquid such as an ink having a large content of an organic solvent and can further improve the durability.

The liquid discharge head according to the present invention is
A substrate having an energy generating element for liquid discharge, a flow path forming member having a flow path, and a discharge port forming member having a discharge port for discharging the liquid supplied from the flow path by energy from the energy generating element. A liquid discharge head in which the flow path forming member and the discharge port forming member are provided in this order on the substrate.
The flow path forming member contains a crosslinked cured product of a polyfunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the structure.
The concentration of the component derived from the polyhydric alcohol in the flow path forming member is lower on the substrate side than on the discharge port forming member side.
The method for manufacturing such a liquid discharge head according to the present invention is as follows.
A substrate having an energy generating element for liquid discharge, a flow path forming member having a flow path, and a discharge port forming member having a discharge port for discharging the liquid supplied from the flow path by energy from the energy generating element. A method for manufacturing a liquid discharge head, wherein the flow path forming member and the discharge port forming member are provided in this order on the substrate.
(1) A step of forming a layer of a photosensitive resin composition for a flow path forming member containing a polyfunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the structure on a substrate.
(2) A step of exposing a pattern for forming a flow path on the layer of the photosensitive resin composition formed on the substrate to form a latent image having the pattern of the flow path.
(3) A step of developing a latent image having the pattern of the flow path to form the flow path, and
(4) A step of laminating a layer of a material for a discharge port forming member on a layer of a photosensitive resin composition for the flow path forming member.
(5) A step of forming a discharge port in a layer of a material for the discharge port forming member to obtain a discharge port forming member, and
Have,
The layer of the photosensitive resin composition for the flow path forming member has a first surface on the substrate side and a second surface facing the first surface, and the photosensitive resin composition The concentration of the polyhydric alcohol in the layer is lower on the first surface side than on the second surface side.

According to the present invention, it is possible to deal with liquids such as inks containing a large amount of organic solvent, and by further improving the durability, stable droplet ejection for a long period of time is possible. It is possible to provide a liquid discharge head having a long life.

It is a schematic diagram of one form of the inkjet recording head of this invention. It is a schematic diagram of another form of the inkjet recording head of this invention. It is a figure for demonstrating an example of the manufacturing method of the inkjet recording head of this invention. It is a schematic diagram which shows an example of the discharge port shape of the inkjet recording head of this invention. It is a schematic diagram which shows an example of the manufacturing method of the inkjet recording head of this invention. It is a schematic diagram which shows an example of the manufacturing method of the inkjet recording head of this invention.

The liquid discharge head according to the present invention includes a substrate having an energy generating element for liquid discharge, a flow path forming member having a flow path, and a discharge port for discharging the liquid supplied from the flow path by energy from the energy generating element. It is provided with a discharge port forming member having the above. The flow path forming member is provided in contact with the substrate, and the discharge port forming member is provided in contact with the flow path forming member. That is, the flow path forming member and the discharge port forming member are provided on the substrate in the order of the flow path forming member and the discharge port forming member.
The flow path forming member contains a crosslinked cured product of a polyfunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the structure (hereinafter, referred to as “polyhydric alcohol”). Therefore, this crosslinked cured product is derived from at least a resin component derived from a polyfunctional epoxy resin and a component derived from a polyhydric alcohol derived from a polyhydric alcohol and bonded to the resin component (hereinafter referred to as "polyhydric alcohol component"). It is composed. The content of the polyhydric alcohol component in the flow path forming member is smaller on the substrate side than on the discharge port forming member side. That is, the flow path forming member has a distribution of the content ratio of the polyhydric alcohol component in the thickness direction, that is, a concentration distribution, in which the polyhydric alcohol component is less on the substrate side than on the discharge port forming member side. As an example, the concentration of the polyhydric alcohol component in the surface layer portion including the interface of the crosslinked cured product contained in the flow path forming member in contact with the substrate is the concentration of the polyhydric alcohol component in the surface layer portion including the interface in contact with the discharge port forming member. A lower concentration distribution of the polyhydric alcohol component in the thickness direction is formed.
By using a crosslinked cured product of a polyfunctional epoxy resin and a polyhydric alcohol for forming the flow path forming member, the strength and ink resistance of the flow path forming member itself can be further improved. However, according to the study by the present inventors, when a liquid such as ink having a high content of organic solvent is used, the polyhydric alcohol component contained in the flow path forming member adheres to the flow path forming member and the substrate. It was found that the flow path forming member may be peeled off from the substrate. Therefore, in the present invention, the concentration distribution of the polyhydric alcohol component in the thickness direction of the flow path forming member described above is used, and as a result, the flow path is formed by the cross-linking curing structure for the characteristics such as ink resistance. It is possible to obtain the entire member and improve the joint strength between the substrate and the flow path forming member. As a result, further improvement in durability of the liquid discharge head can be achieved.
The concentration distribution of the polyhydric alcohol component in the thickness direction of the flow path forming member is not particularly limited as long as the effect of the present invention can be obtained. In one embodiment, the concentration of the polyhydric alcohol component is 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass or more and 10% by mass or less on the substrate side of the flow path forming member, and the discharge port forming member side. It can be selected from the range of 5% by mass or more and 30% by mass or less, preferably 10% by mass or more and 25% by mass or less.
The concentration of the multivalent alcohol component in the channel forming member is determined by using an infrared spectrophotometer (IR) to quantify the peak derived from the polyhydric alcohol in the channel forming member, for example, the peak of the perfluoroalkyl group. It can be obtained by. Specifically, it can be obtained by converting the detected peak quantification result into the mass of the polyhydric alcohol and dividing by the mass of the entire flow path forming member.
An example of the IR spectrum measurement method will be described below. The ATR method (total reflection measurement method) is used for measuring the IR spectrum. In the ATR method, it is generally possible to obtain information up to a depth of 1 μm from the outermost surface of the measurement target. That is, the concentration of the polyhydric alcohol component on the substrate side and the discharge port forming member side in the present specification is the concentration up to a depth of 1 μm from the surface of the flow path forming member on the substrate side and the discharge port forming member side.

The liquid ejection head can be used as an inkjet recording head that ejects ink to perform characters, images, various patterns, dyeing, and the like. Further, the liquid discharge head can be used to apply liquids for various surface treatments to the surface to be treated by using an inkjet method.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a schematic oblique view showing a cross section of a part of the liquid discharge head according to the embodiment of the present invention. Further, FIG. 1B is a schematic partial cross-sectional view of the liquid discharge head as seen in a plane perpendicular to the substrate passing through AB in FIG. 1A.
The liquid ejection head shown in FIGS. 1A and 1B has a substrate 2 in which energy generating elements 1 for generating energy used for ejecting ink are formed at a predetermined pitch. Examples of the energy generating element include an electric heat conversion element such as a heater and a piezoelectric element such as a piezo element. The substrate 2 is opened with a supply port 3 for supplying ink. The substrate 2 is a substrate made of an inorganic material. Examples of the inorganic material include silicon, silicon carbide, silicon nitride, glass (quartz glass, borosilicate glass, non-alkali glass, soda glass), alumina, gallium arsenic, gallium nitride, aluminum nitride, and aluminum alloys. A silicon substrate is generally used as the substrate 2. On the surface layer side of the substrate 2, a wiring film for driving the energy generating element 1 and an insulating layer and a protective layer made of an inorganic material such as _{SiO 2 and SiN are provided.} A side wall of the flow path 5 is formed on the substrate 2 by the flow path forming member 4. Further, a discharge port forming member 8 having a discharge port 6 and a discharge port 7 as a passage portion including a through hole communicating the flow path 6 and the discharge port 5 is formed on at least the flow path 5 of the flow path forming member 4. Has been done. Further, a liquid repellent layer 9 is formed on the discharge port forming member 8 as needed. The substrate 2 may be in direct contact with the flow path forming member 4, and a resin material such as a polyether amide may be arranged between them as an adhesion improving layer.
The thickness of the flow path forming member 4 and the discharge port forming member 8 can be appropriately determined by the discharge design of the liquid discharge head. The thickness of the flow path forming member 4 is preferably, for example, 3 μm or more and 25 μm or less. The thickness of the discharge port forming member 8 is preferably, for example, 1 μm or more and 25 μm or less.
This liquid discharge head droplets a liquid such as ink supplied from the supply port 3 through the flow path 5 from the discharge port 6 via the discharge portion 7 by applying a pressure generated by the energy generating element 1. Discharge as.
The flow path 5 is also called a pressure chamber. The pressure chamber refers to a region up to the ejection portion 7 on the energy generating element 1 in the space through which the liquid passes, and is a region in which pressure is substantially applied to the ink when the ink is ejected. For example, when the energy generating element 1 is an electric heat conversion element, the pressure chamber is at least a region where bubbles grow due to heat given from the electric heat conversion element.
Further, FIG. 2 is a schematic partial cross-sectional view of a liquid discharge head according to another embodiment of the present invention. Similar to the liquid discharge heads shown in FIGS. 1A and 1B, the liquid discharge head shown in FIG. 2 includes a substrate 2 having an energy generating element 1 and a flow path forming member 4 having a flow path 5. A discharge port forming member 8 having a discharge port 6 is provided. In the liquid discharge head shown in FIG. 2, two supply ports 3a and 3b are connected to one flow path 5, and the liquid in the flow path 5 is passed through the two supply ports (pressure chamber) 5. Can be circulated between the inside and the outside of. Specifically, as shown by the arrow in FIG. 2, the liquid can flow into the flow path 5 through the supply port 3a on the left side and flow out from the supply port 3b on the right side. Due to this flow of liquid, for example, when the liquid ejection head according to the present embodiment is applied to an inkjet recording head, it is possible to suppress thickening of ink in the ejection port 6 and the flow path 5.
The liquid discharge head that circulates the liquid between the flow path 5 and the outside as in the present embodiment is compared with the liquid discharge head that does not circulate because the flow path forming member 4 is in contact with the flowing liquid for a long time. The flow path forming member 4 is likely to swell. Therefore, in the liquid discharge head according to the present embodiment, including the polyhydric alcohol component in the flow path forming member 4 is very effective in improving the strength and ink resistance of the flow path forming member 4. When the polyhydric alcohol component is contained in the flow path forming member 4, the concentration distribution of the polyhydric alcohol component on the substrate side is lower than that on the discharge port forming member side is formed in the flow path forming member. As shown above, the joint strength between the substrate 1 and the flow path forming member 4 can be improved.

Next, the method for manufacturing the liquid discharge head of the present invention will be described below.
The method for manufacturing a liquid discharge head according to the present invention has the following steps.
(1) A step of forming a layer of a photosensitive resin composition for a flow path forming member containing a polyfunctional epoxy resin and a polyhydric alcohol on a substrate.
(2) A step of exposing a pattern for forming a flow path on a layer of a photosensitive resin composition formed on a substrate to form a latent image having a flow path pattern.
(3) A step of developing a latent image having a flow path pattern to form a flow path.
(4) A step of laminating a layer of a material for a discharge port forming member on a layer of a photosensitive resin composition for a member for forming a flow path, and (5) a layer of a material for a discharge port forming member. A process of forming a discharge port and obtaining a discharge port forming member.
The layer of the photosensitive resin composition for the member for forming the flow path has a first surface on the substrate side and a second surface facing the first surface, and is in the thickness direction of the polyhydric alcohol. Has a concentration distribution of polyhydric alcohol whose concentration on the second surface side is lower than that on the first surface side.
The step (1) is particularly limited as long as it is a method capable of obtaining the concentration distribution of the target polyhydric alcohol in the thickness direction in the layer of the photosensitive resin composition as the material for forming the flow path forming member. Can be used without. Examples of the method for step (1) include the following methods.
(I) Layers of two or more photosensitive resin compositions containing a polyfunctional epoxy resin and a polyhydric alcohol and having different concentrations of the polyhydric alcohol are laminated in order from the substrate side so that the concentration of the polyhydric alcohol increases. Method.
(II) A layer of a resin composition containing a polyfunctional epoxy resin and a polyhydric alcohol is heat-treated to form a concentration distribution of the polyhydric alcohol in the thickness direction, and the heat-treated resin composition layer is placed on a substrate. A method of laminating to form a layer of a photosensitive resin composition for a member for forming a flow path on a substrate.
(III) A method for transferring a dry film having a concentration distribution of a target polyhydric alcohol to a substrate.
The layer of the photosensitive resin composition in the method (I) may be formed by using a dry film. The method for forming the concentration distribution of the polyhydric alcohol, which is a feature of the embodiment of the present invention described above, is used when the layer of the photosensitive resin composition is transferred onto the substrate by a dry film. It is very effective in improving the adhesion. The method using a dry film is compared with other methods, for example, a method of directly coating a liquid photosensitive resin composition on a substrate (coating method), when laminating a layer of the photosensitive resin composition on the substrate. This is because the affinity between the layer and the substrate is low, and the adhesion between the obtained layer and the substrate tends to be poor. Compared with the coating method, the dry film method can uniformly form the layer when the layer is formed on the substrate on which through holes such as the supply port and other irregularities have already been formed. It has the advantage of being able to.
As the method (III) for transferring the dry film, a method including the following steps (1-1) to (1-3) can be preferably used.
(1-1) A step of applying a photosensitive resin composition for forming a dry film containing a polyfunctional epoxy resin and a polyhydric alcohol onto a substrate to prepare a dry film.
(1-2) In the dry film, the second surface side where the concentration of the polyhydric alcohol in the film thickness direction is on the substrate side is the surface side as the first surface facing the substrate side of the dry film. A step of forming a higher concentration distribution of polyhydric alcohol, and (1-3) a dry film having a concentration distribution of polyhydric alcohol is passed through a liquid discharge head via the surface side as a second surface of the dry film. A step of transferring to a substrate for forming a layer of a photosensitive resin composition for a member for forming a flow path on the substrate.
Steps (1-1) and (1-2) can be performed as separate steps, or at least as one step in which at least a part is overlapped.
In step (1-2), any method can be used as long as the concentration distribution of the target polyhydric alcohol in the thickness direction can be obtained in the layer of the photosensitive resin composition as the material for forming the flow path forming member. It can be used without any restrictions. Examples of the method for step (1-2) include the following methods.
(I) The number of layers of two or more photosensitive resin compositions for forming a dry film containing a polyfunctional epoxy resin and a polyhydric alcohol and having different concentrations of the polyhydric alcohol is increased in order from the substrate side for forming the dry film. A method of laminating so that the concentration of valent alcohol is low and forming each layer into a dry film.
(Ii) Two or more dry films containing a polyfunctional epoxy resin and a polyhydric alcohol and having different concentrations of the polyhydric alcohol are laminated in order from the base material side so that the concentration of the polyhydric alcohol decreases to form a plurality of layers. How to form a dry film.
(Iii) A method for heat-treating a layer of a photosensitive resin composition containing a polyfunctional epoxy resin and a polyhydric alcohol formed on a base material.
The methods (i) and (ii) are methods in which the steps (1-1) and (1-2) are performed at the same time. The heat treatment in the method (iii) may be performed after forming the dry film on the base material, or may be performed at the same time as forming the dry film from the photosensitive resin composition on the base material as in Examples described later. You may.
By the heat treatment in the method (iii), it is volatile at the heat treatment temperature from the second surface (open surface) which faces the first surface of the dry film on the substrate side and is open to the vapor phase such as air. Polyhydric alcohol evaporates. The amount of evaporation of this polyhydric alcohol decreases according to the depth of the dry film toward the base material. As a result, it is possible to obtain a concentration distribution having a slope that gradually decreases toward the substrate side when the concentration of the polyhydric alcohol changes in the thickness direction of the dry film. When the dry film is transferred to the substrate for the liquid discharge head in step (1-3), the second surface on which the concentration of the polyhydric alcohol facing the first surface of the dry film on the substrate side is reduced is the substrate. The first surface that is in contact with the substrate and forms an interface with the base material becomes the surface for laminating the discharge port forming member. By these steps, it is possible to obtain a concentration distribution of the polyhydric alcohol component in the crosslinked cured product constituting the flow path forming member, in which the concentration of the polyhydric alcohol component is lower on the substrate side than on the discharge port forming member side. ..
The concentration distribution of the polyhydric alcohol formed in the dry film by the heat treatment in the method (iii) in the film thickness direction becomes the lowest with respect to the polyhydric alcohol concentration on the surface facing the base material, and as it approaches the base material side. It has an increasing slope and usually does not have a maximum. Further, the position where the concentration of the polyhydric alcohol is maximized is inside the open surface region facing the base material of the dry film, and the portion where the concentration of the polyhydric alcohol is low is intended as a substrate for the liquid discharge head. Any position may be used as long as the bonding strength to be obtained can be obtained. Further, the dry film can also have a concentration distribution in which the maximum concentration of the polyhydric alcohol is maintained from the position where the polyhydric alcohol concentration is maximum in the film thickness direction of the dry film to the interface with the base material.
In order to obtain such a concentration distribution of the polyhydric alcohol in the film thickness direction in the method (iii), it is preferable to use a base material made of a material that does not allow the polyhydric alcohol to permeate.
Among these, the method (iii) is preferable because the concentration distribution of the polyhydric alcohol can be formed relatively easily.
The order in which the steps (2) to (5) are performed is not limited to this order, and can be changed so that a structure including a flow path forming member and a discharge port forming member on the target substrate can be obtained. The exposure for forming the latent image in the step (2) can be performed before the step (4) or after the step (4). Further, the step (3) can be incorporated in the step (5) or performed after the step (5).
The above steps (2) to (5) when the dry film as a material for the flow path forming member is transferred to the substrate and used are the following steps (2A) to (5A) or (2B) to (2B) to ( It can be carried out by a method including 5B).
Combination of Steps (2A) to (5A) (2A) A step of exposing a pattern for forming a flow path on a dry film transferred onto a substrate to form a latent image having a flow path pattern.
(3A) A step of forming a layer of a photosensitive composition for a discharge port forming member on a dry film on which a latent image is formed so as to cover at least the latent image having a flow path pattern.
(4A) A step of forming a discharge port in a layer of a photosensitive composition for a discharge port forming member to obtain a discharge port forming member, and (5A) developing a latent image having a flow path pattern to form a flow path. Process to do.
Combination of Steps (2B) to (2B) (2B) A step of forming a laminated structure by providing a layer of a photosensitive composition for a discharge port forming member on a dry film transferred onto a substrate.
(3B) A step of exposing a pattern for forming a flow path in a laminated structure to form a latent image having a flow path pattern on a dry film.
(4B) A step of exposing a pattern for forming a discharge port on a laminated structure to form a latent image having a discharge port pattern on a layer of a photosensitive composition for a discharge port forming member, and (5B) flow. A step of developing a latent image having a road pattern and a latent image having a discharge port pattern to form a flow path and a discharge port.
In a latent image having a flow path pattern or a latent image having a discharge port pattern, when the photosensitive resin composition has negative photosensitive properties, the unexposed portion serves as the flow path or the discharge port. Form.

Hereinafter, the first embodiment of the method for manufacturing a liquid recording head according to the present invention will be shown.
3 and 6 are schematic cross-sectional views showing an example of the method for manufacturing the liquid discharge head of the present invention, and are views taken at the same cross-sectional position as in FIG. 1 (B) in the completed state. Hereinafter, an example of the manufacturing method of the present invention will be described in order with reference to the drawings.
FIG. 6: Preparation of dry film and heat treatment First, as shown in FIG. 6, a film base film (base film) 14 made of a photosensitive resin composition (1) dissolved in a solvent, made of polyethylene terephthalate (PET), polyimide, or the like. It is applied onto the surface to prepare a dry film 10 (hereinafter referred to as DF). In this embodiment, a case where a negative type photosensitive resin composition (1) is used for forming DF is shown.
The photosensitive resin composition (1) contains at least a polyfunctional epoxy resin, a swelling inhibitor, and a photoacid generator. The details of the constituent components of this photosensitive resin composition will be described below.
(Multifunctional epoxy resin)
Examples of the polyfunctional epoxy resin include a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a bisphenol A type novolac type epoxy resin, and a polyfunctional epoxy resin having an oxycyclohexane skeleton. As the polyfunctional epoxy resin, a trifunctional or higher functional epoxy resin is preferable. One of these or a combination of two or more of these can be used. Commercially available epoxy resins include "EHPE3150" (trade name) manufactured by Daicel Chemical Corporation, "157S70" (trade name) manufactured by Mitsubishi Chemical Corporation, "jER1031S" (trade name), and "EPICLIN N" manufactured by Dainippon Ink and Chemicals Co., Ltd. -865 ”,“ EPICLON N-695 ”(trade name) and the like can be mentioned.
(Swelling inhibitor)
A polyhydric alcohol is used as the swelling inhibitor. This polyhydric alcohol contains a perfluoroalkyl group in its molecular structure. The perfluoroalkyl group has an effect of suppressing the invasion of water and solvent components in the ink into the resin. In addition, the hydroxyl groups in the polyhydric alcohol ensure good compatibility with the polyfunctional epoxy resin, and in the process of ring-opening polymerization of the epoxy, they chemically bond with the epoxy groups to form a strong crosslinked cured product. It plays a role as a cross-linking agent that constitutes the above. Therefore, a polyhydric alcohol having two or more hydroxyl groups in one molecule is preferable.
Further, when the desired concentration distribution of the swelling inhibitor in the film thickness direction of the dry film is obtained by the heat treatment of DF described later, the swelling inhibitor is volatile or sublimable under the treatment conditions such as the temperature of the heat treatment. It is preferable to have. For example, when the swelling inhibitor has a boiling point, the heat treatment temperature is 90 ° C. or higher and 140 ° C. or lower (details will be described later), and the boiling point is preferably in the range of 90 ° C. or higher and 450 ° C. or lower.
The weight average molecular weight of the swelling inhibitor is preferably 200 or more and 500 or less.
Specific examples of the swelling inhibitor include the following compounds.

(In equation (4), n represents an integer of 1 to 20.)
Further, in order to obtain the desired properties, the swelling inhibitor is preferably a compound having two trifluoromethyl groups and one or two phenyl groups and / or phenylene groups.
As the compound for the swelling inhibitor, preferably, the compounds represented by the above formulas (1) to (3) can be mentioned. Examples of commercially available products include "1,4-HFAB", "1,3-HFAB" and "BIS-AF" (trade name) manufactured by Central Glass. One of these or a combination of two or more of these can be used.
(Photoacid generator)
As the photoacid generator, a sulfonic acid compound, a sulfonium salt compound, an iodonium salt compound, a disulfone compound, a phosphoric acid compound and the like are preferable. Commercially available products include "ADEKA PUTMER SP-170", "ADEKA PTOMER SP-172", "SP-150" (trade name) manufactured by ADEKA, and "BBI-103" and "BBI-102" manufactured by Midori Kagaku Co., Ltd. ( Product name), Sanwa Chemical Co., Ltd. "IBPF", "IBCF", "TS-01", "TS-91" (product name), San Appro Co., Ltd. "CPI-210", "CPI-300", "CPI" -410 ”(trade name),“ Irgacure 290 ”(trade name) manufactured by Ciba Japan, and the like can be mentioned. Two or more kinds of these photoacid generators can be mixed and used.
(Other additives)
Further, a silane coupling agent can be added for the purpose of improving the adhesion performance of the flow path forming member with the adjacent member. Examples of commercially available silane coupling agents include "A-187" (product name) manufactured by Easy Toshiba Silicone Co., Ltd.
In addition, for improving pattern resolution and adjusting sensitivity (exposure amount required for curing), sensitizers such as anthracene compounds, basic substances such as amines, and weak acidity (pKa = -1.5 to 3.). An acid generator or the like that generates the toluenesulfonic acid of 0) can also be added as a cation trapping agent. Examples of commercially available acid generators that generate toluenesulfonic acid include "TPS-1000" (product name) manufactured by Midori Kagaku Co., Ltd. and "WPAG-376" (product name) manufactured by Wako Pure Chemical Industries, Ltd.
The composition of the photosensitive resin composition (1) may be set so as to obtain the desired photosensitivity and physical properties as a flow path forming member, and is not particularly limited.

Next, the DF is heat-treated to partially remove the swelling inhibitor from the DF10 formed using the photosensitive resin composition (1). By using a compound that volatilizes (sublimates) at a relatively low temperature as the swelling inhibitor, heat treatment is performed at the time of DF formation and / or in the DF state, so that the second surface 10B on the film substrate 14 side of the DF 10 is used. The concentration of the swelling inhibitor gradually decreases toward the first surface 10A (DF surface) on the opposite side thereof, and it is possible to give an inclination to the concentration change in the film thickness direction. The temperature and time conditions in the heat treatment can be arbitrarily set so as to have a desired inclination. When the temperature is extremely low, it takes a long time to volatilize, and when the temperature is extremely high, it may be difficult to control the amount of volatilization. Therefore, the temperature of the heat treatment is preferably in the range of 90 ° C. or higher and 140 ° C. or lower. Further, for the purpose of accelerating volatilization, heat treatment may be performed under reduced pressure conditions.
The amount of the swelling inhibitor added before the heat treatment for producing the concentration distribution of the swelling inhibitor is such that the desired characteristics of the crosslinked cured product obtained by the concentration distribution in the film thickness direction can be obtained. Although it can be set arbitrarily, the effect of suppressing swelling may be insufficient when the amount of the swelling inhibitor added to the polyfunctional epoxy resin is extremely small. Further, when the amount of the swelling inhibitor added is extremely large, the crosslink density between the epoxy groups becomes low, and when ink or the like having a high content of organic solvent is used as the liquid for ejection, it is used for the liquid ejection head. This may cause problems such as a decrease in the adhesion with the substrate and the discharge port forming member described later. The amount of the swelling inhibitor added is in the range of 10 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the polyfunctional epoxy resin, and the particularly preferable amount of the swelling inhibitor is added to 100 parts by mass of the polyfunctional epoxy resin. The range is 15 parts by mass or more and 40 parts by mass or less, and more preferably 15 parts by mass or more and 30 parts by mass or less.
Further, the concentration distribution of the polyhydric alcohol in the layer of the photosensitive resin composition forming the DF between the base material side after the heat treatment and the exposed surface side on the opposite side is the exposure to the DF and the exposure to the DF, which will be described later. Since it does not fluctuate significantly even after the process of PEB (Post Exposure Bake), it is preferable that the concentration distribution of the polyhydric alcohol component in the following flow path forming member mentioned above as one embodiment is the same:
0.1% by mass or more and 20% by mass or less on the exposed surface side, preferably 0.1% by mass or more and 10% by mass or less, and 5% by mass or more and 30% by mass or less on the base material side, preferably 10% by mass or more and 25% by mass or less. Less than.
As described above, instead of the heat treatment method, when the concentration distribution of the multivalent alcohol in the thickness direction is obtained from two or more layers having different polyhydric alcohol concentrations, the same polyhydric alcohol can be obtained. Concentration distribution can be used.
The content of the polyhydric alcohol in the DF can be measured in the same manner as the measurement of the concentration of the polyhydric alcohol component in the flow path forming member. For example, the surface of DF before and after heat treatment can be determined by quantifying the peaks of perfluoroalkyl groups and hydroxyl groups using an infrared spectrophotometer (IR). Further, when detecting the inclination due to the change in the concentration of the DF in the film thickness direction, the DF after the heat treatment can be detected by diagonally cutting the DF and performing line analysis of the above peak using infrared rays (IR).

FIGS. 3 (A) and 6 (C): Laminate A DF10 having a concentration distribution of a polyhydric alcohol in the thickness direction is transferred onto a substrate 2 in which an energy generating element 1 and a supply port 3 are arranged by a laminating method. To form a film.
In the photosensitive resin composition (1), in the state of DF10, the concentration of the swelling inhibitor on the side of the second surface 10B on the film substrate 14 side is relatively higher than that on the surface side as the first surface 10A. On the other hand, as shown in FIG. 6C, after laminating on the substrate 2, the concentration of the swelling inhibitor on the first surface 10A side of the substrate 2 side is relative to that of the surface side as the second surface 10B. It becomes low. Therefore, when the liquid discharge head is finally used, the flow path 5 is formed by reducing the concentration of the swelling inhibitor on the side of the first surface 10A of the flow path forming member 4 on the substrate 2 side. There is no concern that the adhesive force between the flow path forming member 4 and the substrate 2 will be reduced. Further, since a sufficient amount of the swelling inhibitor is contained on the side of the second surface 10B on the side of the discharge port forming member 8 forming the discharge port 6 and the discharge portion 7, swelling due to a liquid such as ink is suppressed. It becomes possible.
In order to bring the DF 10 and the substrate 2 into close contact with each other, the DF 10 may be laminated while the substrate 2 is heated. By laminating the DF10 in a state where the substrate 2 is heated, the adhesion between the substrate 2 and the flow path forming member 4 can be further improved in the final liquid discharge head. The heating temperature of the substrate 2 at the time of laminating is preferably relatively low so as not to greatly fluctuate the concentration of the polyhydric alcohol contained in the DF10. Specifically, the heating temperature is 30 ° C. or higher and 100 ° C. or lower, preferably 40 ° C. or higher and 90 ° C. or lower.
FIG. 3B: Exposure of the flow path pattern Next, the DF10 is pattern-exposed through the mask 11 for forming the flow path having the flow path pattern to form a latent image composed of an exposed portion and an unexposed portion. Further, the exposed portion is cured by heat treatment as PEB to form the flow path forming member 4. The unexposed portion having the pattern of the flow path is left as a portion that can be removed by development.
The mask 11 is formed by forming a light-shielding film such as a chrome film on a substrate made of a material such as glass or quartz that transmits light having an exposure wavelength in accordance with a pattern such as a flow path. As the exposure device, use a single wavelength light source such as an I-line exposure stepper or KrF stepper, or a projection exposure device having a broad wavelength of a mercury lamp such as a mask aligner MPA-600 Super (trade name, manufactured by Canon) as a light source. Can be done.
The conditions of PEB are not particularly limited as long as a desired flow path pattern can be formed. PEB can be carried out, for example, at 40 ° C. or higher and 110 ° C. or lower for 3 to 10 minutes. The temperature of PEB is preferably 40 ° C. or higher and 90 ° C. or lower, preferably 50 ° C. or higher and 80 ° C. or lower so as not to significantly change the concentration of the polyhydric alcohol contained in DF10.
FIG. 3 (C): Film formation of discharge port forming member Next, the DF12 of the photosensitive resin composition (2) is prepared in the same manner as in the above-mentioned DF manufacturing step, and a laminating method is performed on the DF10 having a latent image. Transfer to form a film using. In this embodiment, a negative type photosensitive resin composition is used as a material for forming DF12. The DF12 may be laminated in a state in which the substrate 2 is heated in the same manner as the DF10 lamination.
Further, if necessary, the liquid repellent layer 9 is formed on the DF12. The liquid-repellent layer 9 is required to have liquid-repellent properties against a liquid for ejection such as ink. When a water-based ink is used as the ejection liquid, a cationically polymerizable perfluoroalkyl composition or perfluoropolyether composition is preferably used.
The photosensitive resin composition (2) is required to have mechanical strength as a cured product thereof, and further, as a photolithography material, it is necessary to consider the resolvability for forming a fine discharge port. Therefore, a negative type epoxy based on an epoxy resin such as a bisphenol A type novolac type epoxy resin, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, or a trifunctional or higher epoxy resin having an oxycyclohexane skeleton. A resin composition is preferably used. One of these or a combination of two or more of these can be used.
The details of the constituent components of the photosensitive resin composition (2) will be described below.
(Epoxy resin)
By using the above-mentioned epoxy resin having three or more functional epoxy groups, the cured product can be three-dimensionally crosslinked, which is suitable for obtaining desired properties. Commercially available epoxy resins include "Selokiside 2021", "GT-300 series", "GT-400 series", "EHPE3150" (trade name) manufactured by DIC CORPORATION, and "157S70" (trade name) manufactured by Mitsubishi Chemical Corporation. Examples thereof include "Epoxy N-695" and "Epoxy N-865" (trade name) manufactured by Dainippon Ink and Chemicals Co., Ltd. One of these or a combination of two or more of these can be used.
(Photopolymerization initiator)
As the photopolymerization initiator for curing the epoxy resin composition, the same photoacid generator as in the photosensitive resin composition (1) can be used. In the present invention, it is preferable that the sensitivity is higher than that of the above-mentioned photosensitive resin composition (1). Therefore, it is preferable to adjust the type and the amount of addition so as to obtain the desired sensitivity.
(Swelling inhibitor)
Similar to the photosensitive resin composition (1), a swelling inhibitor may be added to the photosensitive resin composition (2). As the swelling inhibitor, a polyhydric alcohol containing a perfluoroalkyl group similar to that of the photosensitive resin composition (1) can be used. However, the concentration of the DF in the film thickness direction is preferably uniform, and the solvent drying when producing the DF is preferably performed at a temperature lower than 90 ° C.
Therefore, the concentration of the polyhydric alcohol as the swelling inhibitor in the photosensitive resin composition (2) can be selected from the range of 0% by mass or more and 30% by mass or less, preferably 0% by mass or more and 20% by mass or less. ..
(Other additives)
Various additives can be used as in the photosensitive resin composition (1), but in the present invention, anthracene compounds and the like are added for the purpose of making the sensitivity higher than that of the photosensitive resin composition (1). A sensitive agent may be added. As a commercially available product, "ADEKA PUTMER SP-100" manufactured by ADEKA Corporation is preferably used.
The composition of the photosensitive resin composition (2) is not particularly limited as long as it can be set so as to obtain the desired photosensitivity and physical properties as a flow path forming member.

FIG. 3D: Exposure of discharge port pattern Next, the DF12 and the liquid repellent layer 9 are pattern-exposed via a mask 13 for forming a discharge port having a discharge port pattern, and the exposed portion and the unexposed portion are formed. Form a latent image. Further PEB cures the exposed portion to form the discharge port forming member 8. The unexposed portion having the pattern of the discharge port 6 and the discharge portion 7 is left in a state where it can be developed and removed.
As the exposure apparatus, the same apparatus as that used for the exposure of the photosensitive resin composition (1) can be used.
In the present embodiment, the exposure amount for curing the DF 12 needs to be smaller than the exposure amount for curing the photosensitive resin composition (1) forming the DF 10. That is, when the photosensitive resin composition (2) forming the DF 12 is exposed, if the light transmitted through the DF 12 has an exposure amount that cures the DF 10, it becomes difficult to remove the unexposed portion of the DF 10 in a later step. , The flow path 5 cannot be formed. For this reason, the photosensitive resin composition (2) needs to have a relatively higher sensitivity than the photosensitive resin composition (1). The difference in light sensitivity of these photosensitive resin layers can be adjusted by the type of resin component, the type of photoinitiator, the blending ratio of these, and the like. Further, the discharge port pattern does not necessarily have to be circular, and the shapes shown in FIGS. 4 (a) to 4 (c) may be appropriately selected in consideration of discharge characteristics and the like. In particular, by using a discharge port having protrusions 15 in the discharge port as shown in FIG. 4C, the liquid is held between the protrusions 15 and a plurality of ink droplets (main droplet and satellite) are formed when the ink droplets are ejected. It is possible to significantly reduce the number of divisions and realize high-quality printing.
FIG. 3 (E): Development Next, the uncured portions of the DF10 and DF12 and the liquid repellent layer 9, which both have latent images, are removed with an organic solvent and developed to form a flow path 5, a discharge port 6, and a discharge portion 7. do. Further, if necessary, heat treatment is performed to complete the liquid discharge head for the purpose of promoting the cross-linking reaction of the flow path forming member 4, the discharge port forming member 8, and the liquid repellent layer 9.

In the above-mentioned manufacturing method, an example in which the DF12 is laminated after the DF10 is exposed is shown, but it is also possible to laminate the DF12 before the exposure of the DF10. The manufacturing method thereof will be described below with reference to FIG.
FIG. 5 is a schematic cross-sectional view showing an example of a method for manufacturing a liquid discharge head according to a second embodiment of the present invention, and is a view seen at the same cross-sectional position as in FIG. 1 (B) in a completed state. The method for producing the DF is the same as the production method according to the first embodiment described above.
First, the DF10 produced using the photosensitive resin composition (1) is transferred onto a substrate 2 on which the energy generating element 1 and the supply port 3 are arranged by a laminating method to form a film (FIG. 5 (A)). )).
Next, the DF12 produced by using the photosensitive resin composition (2) is transferred onto the DF10 by a laminating method and laminated to form a laminated structure composed of the DF10 and the DF12. Further, if necessary, a liquid repellent layer 9 is formed on the DF12 (FIG. 5 (B)).
Next, the photosensitive resin composition (1) 10 and the photosensitive resin composition (2) 12 forming the laminated structure are pattern-exposed through the mask 11 for forming the flow path having the flow path pattern, and exposed. A latent image consisting of a portion and an unexposed portion is formed. Further PEB cures the exposed portion to form a flow path forming member 4 and a part of the discharge port forming member 8 (FIG. 5 (C)).
Next, the DF12 and the liquid-repellent layer 9 forming the laminated structure are pattern-exposed via the mask 13 for forming the discharge port having the discharge port pattern to form a latent image composed of an exposed portion and an unexposed portion. Further, the exposed portion is hardened by PEB to form the discharge port forming member 8 (FIG. 5 (D)). Here, the exposure of the discharge port pattern may be performed before the exposure of the flow path pattern.
Next, the uncured portions of the DF10, DF12, and the liquid repellent layer 9 are removed with an organic solvent to form the flow path 5, the discharge port 6, and the discharge portion 7, and the liquid discharge head is completed (FIG. 5 (E)). ..
In the embodiments shown in FIGS. 3 and 5, the supply port 3 is provided on the substrate 2 before the DF10 is laminated, but the step of forming the supply port 3 on the substrate 1 is not limited to these embodiments. For example, when the step (D) of FIGS. 3 and 5 is completed, the supply port 3 can be formed on the substrate 2 and used as a passage for removing the uncured portion by development.

Examples of the present invention will be shown below, and the present invention will be described in detail, but the present invention is not limited to these examples.
(Examples 1 to 22)
Table 1 summarizes the types and amounts of the swelling inhibitor added to the photosensitive resin composition (1), the baking conditions for DF formation, and the evaluation results of the liquid discharge heads prepared under those conditions. .. Further, in each example, the liquid discharge head was manufactured by using the manufacturing process shown in FIGS. 6 and 3.
First, as shown in FIG. 6 (A), the raw material solution of the photosensitive resin composition (1) is applied onto the film substrate 14, baked, and the photosensitive resin composition (1) having a thickness of 15 μm is obtained. DF10 was prepared. As the film base material 14, a PET film having a thickness of 100 μm was used. The composition of the raw material solution of the photosensitive resin composition (1) is as follows.
-Multifunctional epoxy resin ("EPICLON N-695" manufactured by Dainippon Ink and Chemicals Co., Ltd.): 100 parts by mass- "CPI-210" manufactured by San-Apro Co., Ltd .: 0.5 parts by mass- "A-187" manufactured by Easy Toshiba Silicone Co., Ltd. 5 parts by mass ・ Swelling inhibitor shown in Table 1: See Table 1 for the amount (parts by mass) added to 100 parts by mass of the polyfunctional epoxy resin ・ Propropylene glycol monomethyl ether acetate: 120 parts by mass The abbreviation of the compound part for the agent indicates the following compound.
1,4-HFAB: 1,4-bis (2-hydroxyhexafluoroisopropyl) benzene 1,3-HFAB: 1,3-bis (2-hydroxyhexafluoroisopropyl) benzene BIS-AF: 2,2-bis ( 4-Hydroxyphenyl) Hexafluoropropyl Further, “film side” in Table 1 indicates the surface of DF on the film substrate side.
Here, when the raw material solution of the photosensitive resin composition (1) applied to the film base material 14 was baked, a part of the swelling inhibitor was removed together with the volatilization of the solvent.
・ Bake conditions (temperature and time)
-Concentration of swelling inhibitor after baking (surface side and PET film side)
Is also shown in Table 1.
An oven replaced with a nitrogen atmosphere was used for baking. The concentration of the swelling inhibitor was measured by diagonally cutting the DF and then quantifying the perfluoroalkyl group by IR according to the method described above.
Next, the produced DF was transferred to the substrate 2 on which the energy generating element 1 and the supply port 3 were arranged by using a laminating method while applying heat at 70 ° C. (FIGS. 6 (B) and 6 (C), FIG. 3). (A)). Since the surface side of the DF becomes the side in contact with the substrate 2 due to the lamination, the DF 10 is inclined so that the concentration of the swelling inhibitor increases from the substrate 2 side toward the surface of the DF 10 on the opposite side of the substrate 2. Since the temperature at the time of laminating is as low as 70 ° C., the concentration of the swelling inhibitor does not change in this step.
Next, the DF 10 was pattern-exposed with an exposure amount of ^{9000 J / m 2} using an I-line stepper via a flow path forming mask 11 having a flow path pattern. Further, PEB was performed at 70 ° C. for 5 minutes to cure the exposed portion to form the flow path forming member 4 (FIG. 3 (B)).
Next, in the same manner as in the formation of DF10, the raw material solution of the photosensitive resin composition (2) was applied onto a PET film having a thickness of 100 μm and baked at 80 ° C. for 5 minutes to prepare a DF12 having a thickness of 10 μm. .. As the raw material solution of the photosensitive resin composition (2), the one having the following composition was used.
-"EHPE-3150" manufactured by Daicel Chemical Industries: 100 parts by mass- "CPI-410" manufactured by San-Apro: 2 parts by mass- "A-187" manufactured by Easy Toshiba Silicone Co., Ltd .: 5 parts by mass-Central Glass Co., Ltd. "1,4" -HFAB ": 20 parts by mass, propylene glycol monomethyl ether acetate: 120 parts by mass Since the baking conditions for producing DF from the photosensitive resin composition (2) are 80 ° C. and 5 minutes, the photosensitive resin composition Almost no volatilization of the swelling inhibitor from the coating layer of the raw material solution of (2) and DF12 occurs. Further, DF12 was transferred and laminated on DF10 while applying heat at 70 ° C. using a laminating method. Subsequently, a water-repellent layer 9 composed of a condensate of (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, glycidoxypropyltrimethoxysilane, and methyltriethoxysilane was laminated (FIG. 3 (FIG. 3). C)).
Next, the DF12 and the water-repellent layer 9 were pattern-exposed with an exposure amount of ^{600 J / m 2} using an I-line exposure stepper via a mask 13 for forming a discharge port having a discharge port pattern. Further, PEB was performed at 90 ° C. for 5 minutes to cure the exposed portion to form the discharge port forming member 8 (FIG. 6 (D)).
Next, the uncured portions of the DF10, DF12, and the water-repellent layer 9 were removed with propylene glycol monomethyl ether acetate to form the liquid flow path 5, the discharge port 6, and the discharge portion 7. Then, heating was performed at 200 ° C. for 1 hour to obtain a liquid discharge head (FIG. 6 (E)).
Since the swelling inhibitor is incorporated into the crosslinked network of epoxy groups through the exposure and PEB steps, the concentration of the swelling inhibitor in the flow path forming member 4 and the discharge port forming member 8 in the heating step. Does not fluctuate.
According to each embodiment, since the amount of the swelling inhibitor is small on the substrate 2 side of the flow path forming member 4, it is possible to maintain excellent adhesion. Further, since the discharge port forming member 8 side is in a state in which a large amount of the swelling inhibitor is contained, the swelling can be suppressed even when an ink containing a large amount of an organic solvent is used.

(Comparative Examples 1-2)
A liquid discharge head was produced in the same manner as in Example 1 except that the conditions shown in Table 2 were used. In Comparative Example 1, a liquid discharge head having no swelling inhibitor was produced. Further, in Comparative Example 2, a liquid discharge head having a large amount of swelling inhibitor uniformly contained in the flow path forming member 4 was produced. The evaluation results are also shown in Table 2.
(Comparative Example 3)
In Comparative Example 3, a liquid discharge head having a high concentration of the swelling inhibitor on the substrate 2 side and a low concentration of the swelling inhibitor on the discharge port forming member 8 side was produced. The evaluation results are also shown in Table 3.
The liquid discharge head was manufactured by the following manufacturing method.
First, the raw material solution of the photosensitive resin composition (1) 10 prepared in Example 1 was spin-coated on the substrate 2 on which the supply port 3 was not formed so as to have a thickness of 15 μm, and prebaked under the conditions shown in Table 3. Was done. After that, the liquid flow path 5, the discharge port 6, and the discharge portion 7 were formed in the same steps as in each embodiment. Finally, the supply port 3 was formed by dry etching to complete the liquid discharge head.

(Evaluation method)
The liquid ejection heads obtained in each Example and Comparative Example were mounted on an inkjet printer, and the ink having the following composition was used as the ink, and the head after printing 30,000 sheets was evaluated.
・ Ink composition ・ ・ 2-Pyrrolidone: 20 parts by mass ・ ・ 1,2-Hexanediol: 5 parts by mass ・ ・ Ethylene glycol: 10 parts by mass ・ ・ Black pigment: 5 parts by mass ・ ・ Acrylic resin for dispersion: 10 parts by mass・ ・ Water: 100 parts by mass (peeling evaluation)
The flow path was observed from the discharge port forming surface (opening surface of the discharge port) side of the liquid discharge head with an optical microscope, and the presence or absence of peeling between the substrate 2 and the flow path forming member 4 was confirmed.
No peeling is seen: ◎
Partial peeling is seen, but level that does not affect discharge: ○
Level at which peeling is observed and affects discharge: ×
(Discharge rate fluctuation)
The amount of change in the discharge amount from the initial stage was measured.
Change amount = less than 5%: ◎
Change amount = 5% or more and less than 10%: ○
Change amount = 10% or more: ×

1 Energy generating element 2 Substrate 3 Supply port 4 Flow path forming member 5 Flow path 6 Discharge port 7 Discharge part 8 Discharge port forming member 9 Liquid repellent layer 10 Dry film of photosensitive resin composition (1) 11 For flow path formation Mask 12 Dry film of photosensitive resin composition (2) 13 Mask for forming discharge port 14 Film base material 15 Projection

Claims (20)

A substrate having an energy generating element for liquid discharge, a flow path forming member having a flow path, and a discharge port forming member having a discharge port for discharging the liquid supplied from the flow path by energy from the energy generating element. A liquid discharge head in which the flow path forming member and the discharge port forming member are provided in this order on the substrate.
The flow path forming member contains a crosslinked cured product of a polyfunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the structure.
A liquid discharge head characterized in that the concentration of the component derived from the polyhydric alcohol in the flow path forming member is lower on the substrate side than on the discharge port forming member side. The polyhydric alcohols are 1,4-bis (2-hydroxyhexafluoroisopropyl) benzene, 1,3-bis (2-hydroxyhexafluoroisopropyl) benzene, and 2,2-bis (4-hydroxyphenyl) hexafluoro. The liquid discharge head according to claim 1, which is at least one selected from the group consisting of propyl. The polyfunctional epoxy resin is selected from at least a group consisting of a bisphenol A type novolac type epoxy resin, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, and a trifunctional or higher functional epoxy resin having an oxycyclohexane skeleton. The liquid discharge head according to claim 1 or 2, which is one type. The liquid discharge head according to any one of claims 1 to 3, wherein the concentration of the component derived from the polyhydric alcohol in the flow path forming member is 0.1% by mass or more and 20% by mass or less on the substrate side. .. The liquid discharge according to any one of claims 1 to 4, wherein the concentration of the component derived from the polyhydric alcohol in the flow path forming member is 5% by mass or more and 30% by mass or less on the discharge port forming member side. head. Any one of claims 1 to 5, wherein the concentration distribution of the component derived from the polyhydric alcohol in the thickness direction of the flow path forming member has an inclination that decreases from the discharge port forming member side toward the substrate side. The liquid discharge head according to the section. The liquid discharge head according to any one of claims 1 to 6, wherein the substrate is a silicon substrate. The liquid discharge head according to any one of claims 1 to 7, wherein the flow path forming member is in direct contact with the substrate. The passage according to any one of claims 1 to 8, wherein the flow path is a pressure chamber including the energy generating element inside, and the liquid inside the pressure chamber is circulated to and from the outside of the pressure chamber. Liquid discharge head. A substrate having an energy generating element for liquid discharge, a flow path forming member having a flow path, and a discharge port forming member having a discharge port for discharging the liquid supplied from the flow path by energy from the energy generating element. A method for manufacturing a liquid discharge head, wherein the flow path forming member and the discharge port forming member are provided in this order on the substrate.
(1) A step of forming a layer of a photosensitive resin composition for a flow path forming member containing a polyfunctional epoxy resin and a polyhydric alcohol having a perfluoroalkyl group in the structure on a substrate.
(2) A step of exposing a pattern for forming a flow path on the layer of the photosensitive resin composition formed on the substrate to form a latent image having the pattern of the flow path.
(3) A step of developing a latent image having the pattern of the flow path to form the flow path, and
(4) A step of laminating a layer of a material for a discharge port forming member on a layer of a photosensitive resin composition for the flow path forming member.
(5) A step of forming a discharge port in a layer of a material for the discharge port forming member to obtain a discharge port forming member, and
Have,
The layer of the photosensitive resin composition for the flow path forming member has a first surface on the substrate side and a second surface facing the first surface, and the photosensitive resin composition A method for producing a liquid discharge head, wherein the concentration of the polyhydric alcohol in the layer is lower on the first surface side than on the second surface side. In the step (1), the layers of the polyfunctional epoxy resin and the photosensitive resin composition containing the polyhydric alcohol are heat-treated to form a concentration distribution of the polyhydric alcohol, and the heat-treated photosensitive. The liquid discharge head according to claim 10, further comprising a step of laminating a layer of the resin composition on the substrate and forming a layer of the photosensitive resin composition for the flow path forming member on the substrate. Manufacturing method. The method for manufacturing a liquid discharge head according to claim 10, wherein the step (1) is performed by a method including the following steps (1-1) to (1-3).
(1-1) A step of applying the polyfunctional epoxy resin and a photosensitive resin composition for forming a dry film containing the polyhydric alcohol onto a substrate to prepare a dry film.
(1-2) In the dry film, the concentration of the polyhydric alcohol is higher on the second surface side on the base material side than on the surface side as the first surface facing the base material side of the dry film. A step of forming the concentration distribution of the polyhydric alcohol, which is higher than that of the above, and (1-3) a dry film having the concentration distribution of the polyhydric alcohol is passed through the surface side of the dry film as a second surface. A step of transferring to the substrate to form a layer of a photosensitive resin composition for the flow path forming member on the substrate. The method for manufacturing a liquid discharge head according to claim 12, wherein the step (1-2) includes a step of heat-treating the dry film on the base material to form a concentration distribution of the polyhydric alcohol. The method for manufacturing a liquid discharge head according to claim 11 or 13, wherein the temperature of the heat treatment is selected from the range of 90 ° C. or higher and 140 ° C. or lower. 11. A method for manufacturing a liquid discharge head. The polyhydric alcohols are 1,4-bis (2-hydroxyhexafluoroisopropyl) benzene, 1,3-bis (2-hydroxyhexafluoroisopropyl) benzene, and 2,2-bis (4-hydroxyphenyl) hexafluoro. The method for producing a liquid discharge head according to any one of claims 10 to 15, which is at least one selected from the group consisting of propyl. The polyfunctional epoxy resin is selected from at least a group consisting of a bisphenol A type novolac type epoxy resin, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, and a trifunctional or higher functional epoxy resin having an oxycyclohexane skeleton. The method for manufacturing a liquid discharge head according to any one of claims 10 to 16, which is one type. The method according to any one of claims 10 to 17, wherein the concentration of the polyhydric alcohol in the layer of the photosensitive resin composition is 0.1% by mass or more and 20% by mass or less on the first surface side. A method for manufacturing a liquid discharge head. The liquid discharge according to any one of claims 10 to 18, wherein the concentration of the polyhydric alcohol in the layer of the photosensitive resin composition is 5% by mass or more and 30% by mass or less on the second surface side. How to manufacture the head. Claims 10 to 19 have an inclination in which the concentration distribution of the polyhydric alcohol in the thickness direction of the layer of the photosensitive resin composition decreases from the second surface side toward the first surface side. The method for manufacturing a liquid discharge head according to any one of the following items.

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