JP5693204B2 - Method for manufacturing ink jet recording head - Google Patents

Description

  The present invention relates to a method for manufacturing an ink jet recording head capable of ejecting ink droplets.

  In the ink jet recording head, it is important to control the surface characteristics of the discharge port surface in order to obtain good ink discharge performance. If an ink pool remains in the vicinity of the ejection port, the flying direction of the ink droplet may be deflected, or a load may be applied to the ejected ink droplet, resulting in a decrease in the ejection speed of the ink droplet. As a method of improving these and discharging ink with high accuracy, there is a method of performing water-repellent processing around the discharge port.

  In order to arrange the discharge ports at high density, a method using photolithography is useful for forming the member provided with the discharge ports. Patent Document 1 discloses the use of a condensation product of a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationic polymerizable group as a water-repellent material having photosensitivity. Yes. In Patent Document 1, the water repellent material is used to perform water repellent processing by simultaneously performing patterning exposure and development on a water repellent layer and a layer forming a member provided with a discharge port. .

JP 2010-23525 A

  In general, many of the water repellent materials contain fluorine atoms that have a low affinity with organic resins, so that the water repellent materials may aggregate depending on the application conditions. In particular, when a solution of a compound containing a perfluoroalkyl group or a perfluoropolyether group exhibiting high water repellency is applied, the water repellent material may aggregate in the process of volatilization of the solvent.

  As shown in FIG. 1, in Patent Document 1, after forming an uncured photosensitive resin layer 1 as a water repellent treatment (FIG. 1A), on the photosensitive resin layer 1 provided on the substrate 5. The water repellent material layer 2 is provided by applying a water repellent material solution to the substrate and performing a heat treatment (FIG. 1B). Thereafter, pattern exposure and development are performed to form a fine pattern including ejection openings. When the water repellent material is applied, the photosensitive resin layer 1 is uncured and soft. Therefore, depending on the type of water repellent material solution, the water repellent material agglomerates as shown in FIG. 1B during the steps such as application of the water repellent material, pattern exposure, and heating on the photosensitive resin layer 1. There is a concern that the object 3 sinks into the photosensitive resin layer 1 to cause a dent. In the case where the photosensitive resin layer 1 is depressed due to aggregation of the water repellent material, the photosensitive resin layer 1 is a member provided with a discharge port, and therefore a member surface (referred to as a discharge port surface) where the discharge port exists. ) Is indented. Since a part of the dent on the discharge port surface falls on the edge of the discharge port, the surface shape around the discharge port becomes non-uniform, and ink components such as pigments tend to adhere, leading to poor printing. . Further, in some inkjet heads, the discharge port surface is covered with a protective tape from the time it is shipped until the user starts use, and the user peels off the protective tape at the start of use. If the discharge port surface is uneven, the adhesive of the protective tape tends to remain on the discharge port surface when the tape is peeled off, which may be a factor affecting printing.

  An object of the present invention is to suppress the occurrence of dents in a member provided with discharge ports due to aggregation of water repellent material, and to form a discharge port surface with excellent water repellency, thereby realizing high-density and high-quality printing. An ink jet recording head is provided.

An example of the present invention is a method for manufacturing an ink jet recording head, comprising: a substrate; and a discharge port member provided with a discharge port for discharging ink, and having a surface on which the discharge port is open and having water repellency, a step of providing a curable resin layer containing a curable resin material for serving as the discharge port member on the substrate, and curing the discharge port member to become part of the cured resin layer, the curing A step of performing a plasma treatment on the surface of the curable resin layer performed, and reacting with a functional group of the curable resin material on the surface of the curable resin layer subjected to the plasma treatment to bond a step of providing a water-repellent layer comprising a water-repellent material capable of forming, with the uncured portions of the curable resin layer, and a portion corresponding to the uncured portions of the curable resin layer of the water repellent layer, By forming the discharge port by removing Forming a serial discharge port member, a method for producing an ink jet recording head having a.

  According to an example of the present invention, on the surface of a member provided with a fine pattern including a discharge port, the generation of a dent due to aggregation of the water repellent material is suppressed, and a discharge port surface having excellent water repellency and durability is formed. Therefore, it is possible to provide an ink jet recording head that realizes high-density and high-quality printing.

It is sectional drawing which shows the formation method of the conventional water repellent layer. It is sectional drawing which shows the formation method of the water repellent layer which concerns on this invention. It is a perspective view which shows an example of the inkjet recording head manufactured by the method based on this invention. It is sectional drawing which shows an example of the manufacturing method of the inkjet recording head which concerns on this invention. It is a schematic diagram which shows an example of the plasma processing apparatus which concerns on this invention. (A) A schematic view of a direct plasma processing apparatus. (B) A schematic diagram of a remote type plasma processing apparatus.

  As a result of intensive studies, the inventors of the present invention formed a discharge port surface excellent in flatness, water repellency, and durability without a dent due to aggregation of the water repellent material by the following method. The present invention for providing an ink jet recording head for realizing printing has been completed.

  FIG. 2 shows a cross-sectional view when the water repellent layer is formed by the method according to the present invention. After forming a negative photosensitive resin layer 1 as an example of an uncured curable resin layer on the substrate 5, pattern exposure is performed on the photosensitive resin layer 1 using a mask 9, thereby including a discharge port. A latent image having a fine pattern is formed (FIG. 2A). In the exposed portion 4 of the photosensitive resin layer, the polymerization reaction of the resin proceeds and hardens, so that the hardness of the resin increases as compared with the unexposed portion 1. Thereafter, a water-repellent layer containing a water-repellent material is formed (FIG. 2B), and an unexposed portion is removed by development processing to form a fine pattern (FIG. 2C). As shown in FIG. 2, the deformation of the photosensitive resin layer 1 can be suppressed by forming the water repellent layer 2 after the latent image is formed.

  An example of an ink jet recording head manufactured by the method according to the present invention is shown in FIG. The ink jet recording head shown in FIG. 3 has a discharge port member 100 provided with discharge ports 13 for discharging ink on a substrate 5 having a plurality of energy generating elements 15 for discharging ink. The ink flow path 16 that holds the ink in communication and the groove 17 formed to reduce the internal stress of the discharge port member 100 are further provided. The substrate 5 is provided with an ink supply port 14 for supplying ink to the ink flow path 16. The outer surface where the discharge port of the discharge port member 100 is open is water-repellent.

  Hereinafter, although an example of embodiment of this invention is demonstrated in detail, this invention is not limited to this. FIG. 4 is a view showing a method of manufacturing an ink jet recording head according to the present invention, and FIGS. 4A to 4H are process sectional views corresponding to the A-A 'section of FIG.

  First, a mold resist 6 serving as an ink flow path is formed on a substrate 5 provided with wiring, a protective film (not shown), and an energy generating element 15 for generating ink ejection energy on a Si substrate (FIG. 4 ( A)). At this time, in addition to the portion that becomes the ink flow path, a mold resist 7 that serves as a base for controlling the coating film thickness of the photocationic polymerizable resin layer 8 that becomes the discharge port member 100 is formed as necessary. Since the type resists 6 and 7 need to be dissolved and removed in a later step, positive type photosensitive resins are used for the type resists 6 and 7. Specifically, for example, vinyl ketone photodegradable polymer compounds such as polymethyl isopropenyl ketone and polyvinyl ketone are used.

  Next, a cationic photopolymerizable resin layer 8 is formed on the mold resists 6 and 7 as an example of a curable resin to be a discharge port member (FIG. 4B). The cationic photopolymerizable resin layer 8 can be formed by a general application method such as spin coating, slit coating, or roll coating.

  The cationic photopolymerizable resin layer 8 contains a cationic photopolymerizable resin. Examples of the cationic photopolymerizable resin include epoxy compounds, vinyl ether compounds, oxetane compounds and the like. Especially, since high mechanical strength and strong adhesiveness with a foundation | substrate are required, the epoxy resin which has those characteristics is preferable. Examples of the epoxy resin include bisphenol A type epoxy resin and novolac type epoxy resin. For commercial products, polyfunctional epoxy resins such as SU8 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and EHPE3150 (trade name, manufactured by Daicel Chemical Industries, Ltd.) are suitable.

  The epoxy compound preferably has an epoxy equivalent of 100 or more and 2000 or less, and more preferably an epoxy equivalent of 1000 or less. When the epoxy equivalent is 2000 or less, it is possible to prevent the crosslinking density from being lowered during the curing reaction, the glass transition temperature of the cured product from being lowered, or the adhesion from being lowered. Moreover, when an epoxy equivalent is too small, mechanical strength and a photosensitive characteristic may fall.

  In addition, the photocationically polymerizable resin layer 8 is solid at room temperature of 5 to 35 ° C. because the resolution may be deteriorated if there is fluidity during the patterning step. Is preferred.

  Examples of the photocationic polymerization initiator for curing the photocationic polymerizable resin layer 8 included in the photocationic polymerizable resin layer 8 include photoacid generators such as aromatic iodonium salts and aromatic sulfonium salts. . Furthermore, cationic polymerization can be accelerated | stimulated by using a thermal acid generator together with this photocationic polymerization initiator, and heating. Examples of the thermal acid generator include copper triflate in consideration of reactivity and solubility in an epoxy resin.

  Next, pattern exposure is performed through the mask 9 so that the positions at which the discharge ports 13 and the grooves 17 of the photocationically polymerizable resin layer 8 are formed are unexposed portions 10 to form a latent image of the discharge port pattern. (FIG. 4C). And the bridge | crosslinking arises in the exposure part 11 of the photocationic polymerizable resin layer 8 with the acid which generate | occur | produced when exposed (FIG.4 (D)). If the crosslinking rate is too small, deformation such as dents may occur in the photocationically polymerizable resin layer 8 due to the influence of the water-repellent material coating on the photocationically polymerizable resin layer 8 in the next step. It is preferable to cure to such an extent that it does not occur. In order to advance the curing, it is also useful to perform a heat treatment after the exposure. The heating conditions depend on the type of the photocationically polymerizable resin, but when heated to a temperature close to the glass transition temperature of the resin, the curing reaction proceeds rapidly.

  Moreover, in order to produce | generate a chemical bond between the water-repellent layer 12 and the photocationic polymerizable resin layer 8 which are provided in the next step, it is preferable that the reactive group remains. For example, when an epoxy compound is used as the cationic photopolymerizable resin, it is preferable to suppress the crosslinking rate so that an epoxy group remains. Here, when the crosslinking rate indicating the degree of crosslinking is defined by the following formula (1), the crosslinking rate is preferably 5% or more and 95% or less, and more preferably 20% or more and 90% or less. . The residual amount of epoxy groups can be measured by infrared spectroscopy.

  In order to increase the reactivity between the photo cationic polymerizable resin layer 8 and the water repellent layer 12, it is also useful that the photo cationic polymerizable resin layer 8 contains a compound containing a hydroxyl group or a compound capable of generating a hydroxyl group.

  Specific examples of the compound containing a hydroxyl group include 1,4-HFAB (1,4-bis (hexafluoro-2-hydroxy-2-propyl) benzene). As a compound which can produce | generate a hydroxyl group, the compound etc. which have a hydrolyzable silyl group are mentioned, for example. Specific examples include silane compounds having an alkoxysilyl group, so-called silane coupling agents. As specific examples of the silane compound, an alkoxysilane compound having an epoxy group is preferable, such as a commercial product A-187 (trade name, manufactured by GE Toshiba Silicone), KBE-403 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. Since the silane compound having an epoxy group can react with both the water repellent layer 12 and the photocationically polymerizable resin layer 8, it is suitable for improving the adhesion of the water repellent layer 12.

Further, as a useful means for increasing the reactivity between the photocationically polymerizable resin layer 8 and the water repellent layer 12, plasma treatment can be mentioned. In general, plasma is an ionized gas state, which is composed of active species in various states such as ions, electrons, radicals, etc., and activates the surface of the photocationically polymerizable resin layer 8 by plasma treatment to react with the surface. It is possible to add a functional group. By this treatment, the water repellent layer 12 and the photo-cationic polymerizable resin layer are used. As the plasma treatment, one using a direct type treatment apparatus and one using a remote type treatment apparatus can be given. FIG. 5 shows a configuration example of a plasma processing apparatus of (A) direct type and (B) remote type, but the present invention is not limited to these. In the direct type plasma treatment, a gas to be reacted is introduced between opposed electrodes 18 and a high frequency power is applied to generate plasma 19, and a substrate 20 to be treated is placed between the electrodes to perform the treatment. It is. On the other hand, the remote type plasma treatment means a configuration in which a plasma 19 generated between the electrodes 18 is ejected from between the electrodes by a carrier gas, and the substrate 20 to be treated at a position away from the electrodes 18 is treated.

  As a surface treatment of the photo-cationic polymerizable resin layer, when a remote type plasma treatment apparatus is used, it is possible to effectively suppress the curing reaction of the unexposed area and react with the water repellent material on the resin surface as described later. It becomes possible to introduce a group.

  Remote plasma processing apparatuses include atmospheric pressure plasma processing (= atmospheric pressure plasma processing) in which processing is performed under atmospheric pressure, and reduced pressure plasma processing in which processing is performed in a reduced pressure environment. In the atmospheric pressure plasma treatment, a carrier gas is used to blow a plasma gas from between the electrodes as shown in FIG. As described above, the plasma contains charged particles by ionization, but the active species having a charge has a shorter lifetime than the active species having no charge such as radicals. Therefore, by leaving the electrodes and reaching the surface of the substrate to be processed, charged particles such as ions and electrons are almost disappeared, and only particles having substantially no charge such as radicals remain in the plasma. . Therefore, it becomes difficult to influence the polymerization reaction of the cationic polymerizable resin. In order to prevent the charged particles from reaching the substrate, it is also preferable to provide a filter 21 having a charge shielding function at the plasma outlet.

  In the case of low-pressure plasma treatment, it is necessary to install a reduced-pressure chamber. On the other hand, the active species in the plasma has a relatively long life, so the distance from the plasma source electrode to the substrate to be treated is atmospheric pressure. Many are longer than in the case of plasma treatment. Therefore, in the low-pressure plasma apparatus, the influence on the patterning characteristics can be suppressed without installing a charge shielding filter. Examples of the low-pressure plasma processing method include a processing method in which a processing chamber is set in a plasma atmosphere.

  As the plasma generation source and the carrier gas, a non-reactive gas such as helium or argon or a reactive gas such as oxygen, nitrogen, carbon dioxide, or nitrogen oxide can be used. For the purpose of introducing a functional group to the resin surface, it preferably contains at least one of an oxygen atom and a nitrogen atom. In the case of atmospheric pressure plasma, oxygen plasma can usually be generated by the influence of the surrounding atmosphere even if only the non-reactive gas is used. On the other hand, in the case of low-pressure plasma, it is performed by using a reactive gas such as oxygen, nitrogen or carbon dioxide. Nitrogen plasma is less reactive than oxygen plasma or carbon dioxide plasma, and its introduction efficiency to the resin surface is low. Therefore, a mixing ratio of oxygen gas of 10% or less is sufficient. A higher content ratio is preferred. In the case of using non-reactive gas and nitrogen gas without using oxygen, the treatment is performed with nitrogen gas at 50% or more, preferably 90% or more.

  Even when the plasma treatment is not performed, functional groups such as a hydroxyl group, an epoxy group, and an oxetane group are usually present on the surface of the photo cationic polymerizable resin layer 8. Oxygen plasma treatment further increases hydroxyl groups and introduces oxygen-containing groups such as carboxyl groups and carbonyl groups onto the resin surface. In the nitrogen plasma treatment, nitrogen-containing groups such as amino groups, nitro groups, and nitroso groups are introduced. In addition, oxygen and moisture in the air are easily added to the resin surface that has become very active by the plasma treatment, and oxygen-containing groups such as hydroxyl groups may be generated even in the nitrogen plasma treatment.

Next, the water repellent layer 12 is formed on the photocationically polymerizable resin layer 8 (FIG. 4E). The water repellent layer 12 can be formed by a film forming method such as a general-purpose spin coating method, slit coating method, roll coating method, dip coating method, or vacuum deposition method. As the water repellent material contained in the water repellent layer 12, a compound having a fluorine-containing group is used. In particular, in order to obtain high water repellency, it is more preferable to use a compound having a perfluoroalkyl group or a perfluoropolyether group. As the perfluoroalkyl group, for example, the following formula (2)
_{F- (CF 2) n- (2} )
(In the formula (2), n is an integer of 3 or more). As the perfluoropolyether group, for example, the following formula (3)

(In formula (3), p, q, r, and s are 0 or an integer of 1 or more, and at least one is an integer of 1 or more).

  Comparing the number of repeating units (n, p, q, r, s) of these water repellent groups, generally, in commercially available water repellent materials, n is often an integer of 11 or less, and p, q, r , S is often relatively large, such as about 10 to 50. In a perfluoroalkyl group, when the number n of repeating units is too large, the solubility of the compound is lowered and handling becomes difficult. Further, compounds having n of 7 or more are subject to environmental problems, but compounds having a relatively small n may have insufficient water repellency. Therefore, the water repellent material having a perfluoropolyether group contains more fluorine atoms in one molecule than the water repellent material having a perfluoroalkyl group, and tends to exhibit high water repellency. The average molecular weight of the perfluoropolyether group is preferably from 500 to 20000, since water repellency is not exhibited if it is too small, and if it is too large, the solubility in a solvent is reduced. It is more preferable that In addition, in the case of the said Formula (3), the average molecular weight of a perfluoro polyether group shows the average molecular weight of the part shown by a repeating unit.

  As described above, as the water repellent material contained in the water repellent layer 12, a compound that can react with a functional group on the resin surface of the photocationically polymerizable resin layer 8 to form a bond is used. In addition to the hydroxyl group, epoxy group, and oxetane group originally contained in the resin layer, the above oxygen-containing group and nitrogen-containing group are present on the surface of the photocationically polymerizable resin layer 8 by plasma treatment. Therefore, a water repellent material having a hydroxyl group, an epoxy group, a carboxyl group, a silyl group or the like as a functional group capable of reacting with these functional groups to form a bond is used.

  From the viewpoint of reactivity, a compound having a hydrolyzable silyl group at the terminal is preferred. As such a water repellent material, for example, the following formula (4)

(In the formula (4), Rf is a perfluoroalkyl group or perfluoropolyether group, R is a hydrolyzable substituent, X is an alkylene group having 1 to 3 carbon atoms, Y is a non-hydrolyzable substituent, and a is A compound represented by the following formula (5):

(In Formula (5), Rf, R, X, Y, and a are synonymous with Formula (4).), The following formula (6)

(In formula (6), Rf, R, X, Y and a are as defined in formula (4), Z is a hydrogen atom or an alkyl group, and m is an integer of 1 to 5). Compounds.

  Examples of the hydrolyzable substituent R in the formula include a halogen atom, an alkoxy group, an amino group, and a hydrogen atom. Among them, an alkoxy group such as a methoxy group or an ethoxy group is preferable because the group eliminated by the hydrolysis reaction does not inhibit the cationic polymerization reaction and the reactivity is easily controlled. Examples of the non-hydrolyzable substituent Y include an alkyl group having 1 to 20 carbon atoms and a phenyl group. Examples of X include a methylene group, an ethylene group, and a propylene group.

  Among commercially available products, OPTOOL DSX, OPTOOL AES (trade name, manufactured by Daikin Industries, Ltd.), Novec EGC-1720 (trade name, manufactured by Sumitomo 3M Limited), FG-5010, FG-5020, FS-2050 (over product) Name, manufactured by Harves Co., Ltd.), OPC-700, OPC-800, XOPC-900 (all trade names, manufactured by Noda Screen Co., Ltd.), and the like.

  When the water repellent material has a hydrolyzable silyl group, hydrolysis occurs due to moisture in the air, and a silanol group is generated. Furthermore, reaction with a silanol group and the epoxy group and hydroxyl group which exist in the photocationic polymerizable resin layer 8 surface is accelerated | stimulated by heating. At this time, in order to promote hydrolysis of the water repellent material and further generate silanol groups, the water repellent layer 12 is formed in a humidified environment, or a humidified environment is experienced after the water repellent layer 12 is formed. Is also useful.

  The concentration of the water repellent material solution when the water repellent material is applied as a solution is appropriately determined depending on the application method, the intended use, and the material of the photocationically polymerizable resin layer 8. The concentration of the water repellent material in the water repellent material solution is preferably 0.01 to 1.0% by weight. More preferably, it is 0.05 to 0.5% by weight. When the concentration of the water repellent material is within the above range, sufficient water repellency and durability are exhibited, and uniform water repellency can be obtained over the entire coating film surface. At this time, it is preferable that the thickness of the water repellent layer 12 is applied in a range of 1 to 20 nm.

  Examples of the solvent for diluting the water repellent material include so-called fluorinated solvents such as hydrofluorocarbon, perfluorocarbon, hydrofluoroether, hydrofluoropolyether, and perfluoropolyether. As those having a relatively low global warming potential, Novec HFE-7100, HFE-7200, and HFE-7600 (trade names, manufactured by Sumitomo 3M Limited), which are hydrofluoroethers, are suitable.

  Next, by developing the photocationically polymerizable resin layer 8, the photocationically polymerizable resin layer 8 and the water repellent layer 12 in the unexposed portion 10 are removed, and the discharge port 13 and the groove 17 are formed (FIG. 4 ( F)). The water repellent layer 12 is formed very thin with a thickness of about 1 to 20 nm, and the water repellent layer 12 in contact with the unexposed portion 10 can be removed together with the unexposed portion 10 during development. For development of the cationic photopolymerizable resin layer 8, a solvent capable of dissolving the unexposed portion 10 of the cationic photopolymerizable resin layer 8 can be used.

  Since the water repellent layer 12 is often poorly soluble in the solvent used for development, it is possible to perform washing to remove the water repellent material that could not be removed after development. As the removal solvent for the water repellent layer 12, it is preferable to use a fluorine-based solvent, which is a solvent for the above-mentioned water-repellent material, or a mixed solvent of a fluorine-based solvent and an organic solvent.

Next, the ink supply port 14 is formed on the back surface of the substrate 5 (FIG. 4G). Finally, the mold resists 6 and 7 are removed using a solvent that can dissolve the mold resists 6 and 7 (FIG. 4H). Thereafter, heating is performed to completely react and cure the unreacted photocationic polymerizable resin material in the photocationic polymerizable resin layer 8. At that time, the reaction between the photocationically polymerizable resin layer 8 and the water repellent layer 12 also proceeds, and the bond between the member provided with the discharge port 13 and the water repellent layer 12 can be further strengthened. Through the above steps, the member having the ejection port 13 and the ink flow path 16 can be provided on the substrate 5.

  Hereinafter, an exemplary embodiment of the present invention will be described with reference to FIG.

[Example 1]
FIG. 4 is a diagram showing a method for manufacturing an ink jet recording head according to the present invention. First, polymethylisopropenyl ketone (manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name: ODUR-1010) on a silicon substrate 5 (6 inch wafer) provided with electrical wiring, a protective film (not shown) and an energy generating element 15 as appropriate. ) With a thickness of 14 μm. Subsequently, the pattern of the mold resist 6 serving as the ink flow path 16 and the pattern of the mold resist 7 serving as the base was exposed by an exposure apparatus UX3000 (manufactured by Ushio Electric Co., Ltd.) and developed with methyl isobutyl ketone to form the mold resists 6 and 7. (FIG. 4 (A)).

  Next, as shown in FIG. 4B, a solution containing the material shown in Table 1 was applied on the substrate 5 having the mold resists 6 and 7 and heat-treated at 60 ° C. for 9 minutes. Thereby, the photocationically polymerizable resin layer 8 was formed. The film thickness of the photocationically polymerizable resin layer 8 was 25 μm at the portions where the mold resists 6 and 7 were not present.

Next, using the exposure apparatus MPA-600 (manufactured by Canon Inc.), the photomask 9 is applied to the photocationically polymerizable resin layer 8 so that the portions that become the discharge ports 13 and the grooves 17 become the unexposed portions 10. Was exposed at an irradiation dose of 300 mJ / cm ² (FIG. 4C). Further, heat treatment was performed at 90 ° C. for 4 minutes (FIG. 4D).

  Thereafter, the compound 7 represented by the following formula (7) (actually, a mixture of compounds having different t and n) is 0.2 weight by fluorine solvent Novec HFE7600 (manufactured by Sumitomo 3M Limited). % To prepare a water repellent solution. 2 ml of the solution was dropped on the photocationically polymerizable resin layer 8 and applied by rotating at 500 rpm. Furthermore, by heat-treating at 90 ° C. for 1 minute, the solvent is volatilized, and at the same time, the reaction between the epoxy resin and hydroxyl group present on the surface of the photocationically polymerizable resin layer 8 and the methoxy group or hydroxyl group of the compound 7 is carried out. Promoted. As a result, a water repellent layer 12 made of a perfluoropolyether group-containing water repellent material was formed. (FIG. 4E). In addition, when it apply | coated also on the silicon wafer on the same conditions and the thickness of the water repellent layer was measured with the ellipsometer, the result of about 10 nm was obtained.

(In formula (7), t represents an integer of 20 to 30, n represents an integer of 1 to 3, and t and n have different values).

  Next, the photocationically polymerizable resin layer 8 was developed with a solution of xylene / MIBK = 6/4 (weight ratio). By this development processing, the unexposed portion 10 of the cationic photopolymerizable resin layer 8 and the water-repellent layer 12 in contact with the unexposed portion 10 are simultaneously removed to form the discharge ports 13 and the grooves 17 (FIG. 4F). ).

Next, a mask for producing the ink supply port 14 is appropriately disposed on the back surface of the substrate 5 , the surface of the substrate 5 is protected by a rubber film (not shown), and then anisotropic using a tetramethylammonium aqueous solution is used. An ink supply port 14 was formed in the substrate 5 by etching (FIG. 4G). Thereafter, the rubber film is removed, and the entire surface of the substrate 5 is irradiated with ultraviolet rays using an exposure apparatus UX3000 to decompose the mold resists 6 and 7, and the photocations obtained by dissolving and removing the mold resists 6 and 7 using methyl lactate. In order to completely cure the polymerizable resin layer 8 and promote the reaction between the functional groups remaining on the surface of the photo-cationic polymerizable resin layer 8 and the functional groups of the water repellent layer 12, heating is performed at 200 ° C. for 1 hour. Processing was performed (FIG. 4 (H)).

  Thus, the discharge port member 100 was formed. Thereafter, means for electrical connection and ink supply were appropriately arranged to produce an ink jet recording head.

  As an evaluation of the manufactured inkjet recording head, the surface state of the member 100 provided with the discharge ports 13 is observed using a color 3D laser microscope VD-9710 (manufactured by Keyence Corporation), and the presence or absence of dents and pattern residues is determined. confirmed. Further, the dynamic receding contact angle θr with respect to pure water on the surface of the member was measured using an automatic contact angle measuring device CA-W (manufactured by Kyowa Interface Science Co., Ltd.). Subsequently, the water-repellent surface of the discharge port member was immersed in an alkaline dye ink BCI-7C (manufactured by Canon Inc.) at 60 ° C. for 1 week, and then θr was measured by the method described above.

Table 1 summarizes the types, concentrations, and plasma treatment conditions of the water repellent materials of Example 1 and the following Examples and Comparative Examples, and the evaluation results thereof. In addition, the evaluation index of each evaluation result is as follows.
<Dent>
○: A dent with a diameter of 1 μm or more is not confirmed and is smooth.
Δ: Recesses having a diameter of 1 μm or more are confirmed.
<Residue>
◎: No residue ○: Residue is slightly present (although it is hardly observed with the above microscope, there is no significant influence on the actual discharge to the extent confirmed by SEM)
<Change in contact angle after ink immersion>
A: The difference between the contact angle after storage and the initial contact angle is less than 15 degrees. ○: The difference between the contact angle after storage and the initial contact angle is 15 degrees or more and less than 30 degrees.

[Examples 2 and 5]
An ink jet recording head was prepared in the same manner as in Example 1 except that the type and concentration of the water repellent material were set to the values shown in Table 2, and the measurement was performed in the same manner. In the ink jet recording heads produced by any of the methods of Examples 2 and 5, no dents and residues were found on the surface, and the water repellency was good. Further, in printing evaluation, printing deviation or the like was not observed, and high printing quality was shown.

[Examples 3 and 4]
The ink jet recording head was manufactured in the same process as in Example 1 except that the type and concentration of the water repellent material were set to the values shown in Table 2 and the plasma treatment was performed before the water repellent material was applied. For the plasma treatment, a low-pressure plasma processing apparatus CDE-7-4 (manufactured by Shibaura Mechatronics, described as “depressurized” in Table 2) and a remote atmospheric pressure plasma processing apparatus AP-T03 (manufactured by Sekisui Chemical Co., Ltd., Table 2). In this case, “Atmospheric pressure 1” is used. In the atmospheric pressure plasma processing apparatus AP-T03, a charge shielding plate was used. The evaluation results are shown in Table 2. In the ink jet recording heads produced by any of the methods of Examples 2 and 5, no dents and residues were found on the surface, and the water repellency was good. Further, in printing evaluation, printing deviation or the like was not observed, and high printing quality was shown.

[Examples 6 to 28]
Using the values shown in Table 2 as the type and concentration of the water repellent material and the plasma treatment conditions, the ejection port pattern of the ink jet recording head was produced on the silicon substrate in the same process as in Example 1. Although print evaluation is not performed for simple evaluation, the state of the discharge port surface having the discharge port pattern as in Examples 1 to 5 was evaluated in terms of dents, residue, and contact angle. As the plasma treatment “atmospheric pressure 2”, a direct type plasma treatment apparatus AP-T02 (manufactured by Sekisui Chemical Co., Ltd.) was used. Also in the discharge port member produced by any of the methods of Examples 6 to 28, no dent was seen on the surface, and the water repellency was good.

  As can be seen from the result of the item of change after immersion in the evaluation of the contact angle in Table 1, those subjected to plasma treatment (for example, Examples 3 and 4) have little change in water repellency between the initial stage and after immersion. By performing the plasma treatment, it is considered that an ink jet recording head that can withstand long-term use and has high reliability can be obtained.

<Composition analysis>
Next, in order to investigate the introduction of functional groups onto the resin surface by plasma treatment, composition analysis of the resin surface was performed on the samples with and without plasma treatment before applying the water repellent material.
In Example 1, composition analysis of the surface of the cationic polymerizable resin layer 8 in a state before the water repellent layer 12 was formed was performed. For the measurement, an X-ray photoelectron spectrometer Quantum 2000 (manufactured by ULVAC-PHI Co., Ltd.) was used. As a result, the elemental composition of the surface was 23 atom% oxygen atoms and 0 atom% nitrogen atoms.

  In Example 3 and Example 13, the same measurement was performed on the surface of the cation polymerizable resin layer 8 after the plasma treatment. The results are shown in Table 3. In the case of 100% nitrogen plasma treatment, nitrogen atoms are introduced on the resin surface, and it is considered that amino groups, nitro groups, nitroso groups, cyano groups, and the like are introduced. In addition, when plasma with a nitrogen / oxygen mixed gas was used, the oxygen content on the resin surface increased, and oxygen-containing groups such as hydroxyl groups, carbonyl groups, and carboxyl groups were introduced into the resin surface. Is guessed.

In order to confirm whether nitrogen-containing groups were actually introduced on the resin surface, the time-of-flight secondary ion mass spectrometer TRIFT V was used for the surface of the cationic polymerizable resin layer 8 before application of the water repellent material in Examples 1 and 3. Surface analysis by ULVAC-PHI Co., Ltd. was performed. When Au ions were irradiated as primary ions, NH4 ⁺ , CN ⁻ , and CNO ⁻ ions were observed on the surface subjected to nitrogen plasma treatment (Example 3) compared to the surface without plasma treatment (Example 1). Was observed. Also from this measurement result, it was confirmed that nitrogen atoms were introduced into the resin surface by the nitrogen plasma treatment.

  The structures of the water repellent materials, compounds 8 to 10 shown in Table 2 are shown below.

(In formula (8), u represents an integer of 20-30.)

(In formula (10), v represents an integer of 0 to 20, and w represents an integer of 0 to 30).

[Comparative Example 1]
A step of forming the water repellent layer 12 was performed before the photocationic polymerizable resin layer 8 was exposed, and an ink jet recording head was prepared in the same manner as in Example 1 except that. Evaluation similar to Example 1 was performed. The evaluation results are as shown in Table 1. In Comparative Example 1, θr was high and good water repellency was exhibited, but a dent was generated on the surface of the member provided with the discharge port 13. In printing evaluation, printing deviation occurred. This is considered to be due to the influence of the concave surface.

[Comparative Examples 2 to 9]
As shown in Table 2, the water repellent compound, concentration, and plasma treatment were changed, and an ink jet recording head was prepared by the same production method as in Comparative Example 1 and evaluated.

DESCRIPTION OF SYMBOLS 1 Uncured part of photosensitive resin layer 2 Water repellent material 3 Aggregate of water repellent material 4 Cured part of photosensitive resin layer 5 Substrate 6 Mold resist to be ink flow path 7 Mold resist to be a base 8 Photocationic polymerizable resin Layer 9 Photomask 10 Unexposed portion of the photo cationic polymerizable resin layer 11 Exposed portion of the photo cationic polymerizable resin layer 12 Water repellent layer 13 Discharge port 14 Ink supply port 15 Energy generating element 16 Ink flow channel 17 Groove 18 Electrode 19 Plasma Place of occurrence 20 Substrate to be treated 21 Charge blocking filter

Claims (9)

A method for manufacturing an ink jet recording head, comprising: a substrate; and a discharge port member provided with a discharge port for discharging ink, the discharge port member having a water-repellent surface on which the discharge port is opened.
A step of providing a curable resin layer containing a curable resin material for serving as the discharge port member on the substrate,
Curing the portion serving as the discharge port member of the curable resin layer,
Performing a plasma treatment on the surface of the curable resin layer that has been cured;
Providing a water repellent layer including a water repellent material capable of reacting with a functional group of the curable resin material to form a bond on the surface of the curable resin layer subjected to the plasma treatment ;
The discharge port member is formed by removing the uncured portion of the curable resin layer and the portion corresponding to the uncured portion of the curable resin layer of the water repellent layer to form the discharge port. Forming a step;
A method for manufacturing an ink jet recording head comprising: The functional group is introduced into the surface of the curable resin layer by the plasma treatment, and the introduced functional group contains at least one of an oxygen atom and a nitrogen atom. A method for manufacturing an inkjet recording head. The curable resin layer is a photosensitive resin layer , and in the step of curing the portion to be the discharge port member , the curable resin layer is heated after pattern exposure of the curable resin layer. The manufacturing method of the inkjet recording head of description.   The method for manufacturing an ink jet recording head according to claim 1, wherein the water repellent material is a compound having a perfluoroalkyl group or a perfluoropolyether group. A pre-Symbol curable resin layer is cationically photopolymerizable, the resin material is a hydroxyl group, a epoxy group, oxetane group, carboxyl group, a carbonyl group, an amino group, a nitro group, at least one functional group of the nitroso group the water-repellent material, method for manufacturing an ink jet recording head according to any one of claims 1 to 4 by reacting with the functional group is a compound having a functional group capable of forming a bond to the resin material has . 6. The method of manufacturing an ink jet recording head according to claim 5 , wherein the water repellent material is a compound having a silyl group as the functional group. The plasma processing method for producing an ink jet recording head according to any one of claims 1 to 6, characterized in that is carried out using the remote type plasma processing apparatus.   A functional group containing at least one of oxygen atoms or nitrogen atoms on the surface of the curable resin layer by performing a surface treatment using plasma generated by a gas containing at least one of oxygen atoms or nitrogen atoms The method of manufacturing an ink jet recording head according to claim 2, wherein: The water repellent material has the following formulas (4), (5) and (6):

(In the formula (4), Rf is a perfluoroalkyl group or perfluoropolyether group, R is a hydrolyzable substituent, X is an alkylene group having 1 to 3 carbon atoms, Y is a non-hydrolyzable substituent, and a is Indicates an integer from 1 to 3.)

(In Formula (5), Rf, R, X, Y, and a are synonymous with Formula (4).)

(In Formula (6), Rf, R, X, Y, and a are synonymous with Formula (4). Moreover, Z is a hydrogen atom or an alkyl group, and m shows a positive integer.)
A method for producing an ink jet recording head according to any one of claims 1 to 8 comprising any of the compounds of the compound represented by.