KR100880753B1 - Ink jet head and its manufacture method - Google Patents

Abstract

The ink jet head of the present invention is formed with a nozzle surface having liquid repellency. The nozzle surface comprises a condensation product made from a hydrolyzable silane compound having a fluorine containing group and a hydrolyzable silane compound having a cationically polymerizable group.

Ink jet head, nozzle, liquid repellent, condensation product

Description

Ink jet head and manufacturing method thereof {INK JET HEAD AND ITS MANUFACTURE METHOD}

The present invention relates to a liquid repellent treatment on a nozzle surface in an ink jet head.

In recent years, technology development for smaller droplet size, higher driving frequency and performance improvement of a larger number of nozzles continues to further improve the recording characteristics in the ink jet recording system. Image recording is performed by discharging the liquid from the discharge opening as a small droplet adhered to a recording medium represented by paper.

Here, the surface treatment is becoming more important for maintaining the discharge performance by keeping the discharge opening surface always in the same state.

It is also common to periodically wipe off the ink remaining on the surface, for example with a rubber blade, to maintain the state of the ejection opening surface in the ink jet head. Liquid repellent materials are required for easy wiping and wiping durability.

Since the ink used for the ink jet head is not neutral in most cases, the liquid repellent material also needs to be durable to the ink and adherence to the nozzle.

Moreover, in recent years, precise nozzle structures are required for the nozzles to obtain high quality images, so the liquid repellent material also needs to have photosensitivity corresponding to patterning by photolithography.

This invention applies the hydrolyzable silane compound which has a fluorine-containing group, and performs a liquid repulsion process on the surface of a nozzle.

In the following official documents there is shown a conventional example of using a hydrolyzable silane compound having a fluorine-containing group.

Japanese Patent Application Laid-Open Nos. Hei 06-171094 and Hei 06-210857 use a hydrolyzable silane compound having a fluorine-containing group to perform a so-called silane coupling treatment on a nozzle surface in which an oxide particle layer is formed in advance. It is starting.

However, the method described above does not achieve sufficient wiping durability. In addition, the above-described system also makes it difficult to impart photosensitivity to the liquid repellent material.

U.S. Pat. No. 5,910,372, EP 778869 and Japanese Patent Publication No. Hei 10-505870 disclose a coating consisting of a condensation composition comprising a hydrolyzable silane compound having a fluorine-containing group, and a silane compound having a substituent reacting with the substrate. The applicability of the to an ink jet nozzle is disclosed. In addition, an amino group, a carboxyl group, etc. are mentioned as a substituent which reacts with a board | substrate.

In the above-mentioned composition, crosslinking of the liquid repellent layer means forming a siloxane network through hydrolysis and condensation.

In general, crosslinked siloxane reticular bodies are affected by the inks used in ink jet recording systems, especially when the inks are not neutral aqueous solutions. The siloxane reticulum is hydrolyzed to reduce liquid repellency. In addition, the composition does not mention photosensitivity.

US Pat. No. 6,283,578 and European Patent B1 816094 disclose surface treatment methods with silane compounds having photo-radically polymerizable groups for liquid repellent properties. In this composition, crosslinking of the liquid repellent layer means the formation of siloxane reticulum and photo-radical polymerization, wherein the photo-radical polymerization corresponds to photosensitivity. Liquid repellency comes from the siloxane reticular itself.

The document also refers to the coating of hydrolyzable silane compounds with fluorine containing groups as the second layer of the siloxane structure when higher liquid repellency is required.

However, in the composition of the two layers mentioned above, since the hydrolyzable silane compound layer itself which has a fluorine-containing group does not have photosensitivity, photosensitivity cannot be imparted.

Jpn. J. Appl. Phys. Vol. 41 (2002) P.3896-3901 discloses condensation products of certain aryl silanes with hydrolyzable silane compounds having a fluorine-containing group exhibiting excellent durability in alkaline inks as liquid repellent layers. However, in the composition, it is difficult to add photosensitivity.

The applicant also proposes a method given in Japanese Patent Application Laid-Open Nos. 04-10940 to 04-10942 as a high quality IJ recording method.

In addition, this applicant is Japanese Patent Application Laid-Open No. 06-286149 as a method for producing an IJ head which is optimal for the above-mentioned IJ recording method given in Japanese Patent Application Laid-Open Nos. Hei 04-10940 to No. 04-10942. The method given in suggests.

The method uses a photosensitive material for the nozzle portion and realizes a precise nozzle structure by photolithography technology.

The liquid repellent materials shown in the conventional examples described herein above were difficult to have photosensitivity and difficult to apply to nozzle formation using photolithography techniques.

On the other hand, this applicant is Japanese Patent Application Laid-Open No. 11-322896, Japanese Patent Application Laid-Open No. 11-335440, the same as a liquid repellent material having photosensitivity applicable to Japanese Patent Application Laid-Open No. 06-286149. The material of 2000-322896 is proposed.

The liquid repellent material is excellent in photosensitivity, high liquid repellency, adhesion to the nozzle material, etc., but it is necessary to output a higher quality image at a higher speed, so that higher liquid repellency, durability against wiping ( To maintain high liquid repellency) and ease of wiping is required.

US Pat. No. 5,644,014, European Patent B1 587667 and Japanese Patent Publication No. 3306442 disclose liquid repellent materials using hydrolyzable silane compounds having fluorine containing groups.

Although the material exhibits photocurability using photo-radical polymerization, no mention is made of the formation of patterns using photolithographic techniques or its application to ink jet heads.

The present invention has been completed in consideration of the above-described points, and simultaneously provides high liquid repellency, high durability against wiping (to maintain high liquid repellency), ease of wiping, and high adhesion to nozzle material. The liquid repellent material is provided to the ink jet head to realize high quality image recording.

Further, the present invention is to provide a method of manufacturing an ink jet head for high quality image recording by providing photosensitivity to the liquid repellent material.

One aspect of the present invention devised to achieve the above object consists of a condensation product comprising a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group, and having liquid repellency. It relates to an ink jet head.

Another aspect of the present invention devised to achieve the above object comprises forming a photopolymerizable liquid repellent layer on the photopolymerizable resin layer, and then simultaneously pattern-exposure and developing to form a nozzle surface having liquid repulsion; The photopolymerizable liquid repellent layer relates to a method for producing an ink jet head comprising a condensation product of a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group.

Forming an ink passage pattern with a soluble resin material on the ink discharge pressure generating element on the substrate,

Forming a polymerizable coating resin layer on the soluble resin material pattern,

Forming a liquid repellent layer on the coating resin layer,

Removing the coating resin layer and the liquid repellent layer on the ink discharge pressure generating element to form an ink discharge opening, and

Dissolving the soluble resin material pattern

It is also preferable that the liquid repellent layer contains a condensation product of a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group.

1A, 1B, 1C, and 1D are diagrams showing an example of a method of manufacturing the ink jet head of the present invention.

2A, 2B, 2C, and 2D are views showing another example of the method of manufacturing the ink jet head of the present invention.

3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3I, 3J, and 3K are diagrams showing still another example of the manufacturing method of the ink jet head of the present invention.

<Best way to carry out the invention>

The present invention will be described in detail. As described above, it is well known to use hydrolyzable silane compounds having fluorine-containing groups for the liquid repellent layer of the ink jet head.

However, when the hydrolyzable silane compound having a fluorine-containing group is reacted with the nozzle surface through a hydrolysis reaction so that the liquid repellent layer is formed almost as a molecular layer, the liquid repellent layer is peeled off during the wiping operation of wiping the nozzle surface. The liquid rebound performance of the surface cannot be maintained. In general, since the liquid repellent layer is always in contact with the recording liquid which is not neutral, the liquid repellency deteriorated in response to the hydrolysis reaction. In addition, it was difficult to provide photosensitivity for forming a highly accurate nozzle structure. MEANS TO SOLVE THE PROBLEM The present inventors earnestly discovered that the said subject could be solved by forming a liquid repulsion layer with the condensation product of the hydrolyzable silane compound which has a fluorine-containing group, and the hydrolyzable compound which has a cationically polymerizable group as a result of experiment.

According to the composition of the liquid repellent layer of the present invention, the cured material has a siloxane frame (inorganic frame) formed from hydrolyzable silane and a frame by curing of a cationic polymerizable group (organic frame: ether bond when using an epoxy group). . Accordingly, the cured material becomes a so-called organic and inorganic hybrid cured material, so that the durability to the wiping and its recording liquid is rapidly improved. That is, since the liquid repellent layer of the present invention has an organic frame, it is considered that the strength as a film is improved and its wiping resistance is improved as compared with the liquid repellent layer formed only of the siloxane frame.

In addition, since the organic frame is formed by cationic polymerization (typically forming ether bonds), the frame of the liquid repellent layer is hardly hydrolyzed even if the recording liquid is not neutral, so that significant resistance to the recording liquid is obtained. When the organic frame is obtained by radical polymerization, many radically polymerizable groups represented by methacryloxy groups contain ester bonds which are significantly weak in hydrolysis, and thus may be undesirable in terms of recording solution resistance. In the present invention, the liquid repellent layer formed of the organic frame and the siloxane frame by cationic polymerization reduces the rehydrolysis of the siloxane frame, thereby contributing to the remarkable improvement in recording solution resistance.

Further, according to the present invention, the formation of the siloxane frame and the organic frame by cationic polymerization when curing the liquid repellent layer also contributes to the formation of chemical bonds with the nozzle surface and to the adhesion to the nozzle surface. In particular, it is particularly preferable from the standpoint of the adhesion property that the liquid repellent layer is formed on the cationic polymerizable nozzle layer and then the liquid repellent layer and the nozzle layer are simultaneously cured. In the liquid repellent layer of the present invention, an acid can be generated by light irradiation by including a cationic photopolymerization initiator in the liquid repellent layer, and the liquid repellent layer can be cured by polymerization of a cationically polymerizable group. Curing of the hydrolyzable silane compound (hydrolysis and condensation reactions) is generally carried out by heat, but the hydrolysis reaction can be accelerated due to the presence of acid to form a rigid frame. Furthermore, in the above embodiment, since the photosensitivity can be provided to the liquid repellent layer, a precise nozzle structure can be formed. Also in embodiments where a liquid repellent layer is formed on the cationic polymerizable nozzle layer and then the liquid repellent layer and the nozzle layer are simultaneously cured, both layers are included when a cationic photopolymerization initiator is included inside both the liquid repellent layer and the nozzle layer. Naturally, it can be cured. The inventors have found that the liquid repellent layer can be cured by cationic polymerization even in surprising embodiments in which the liquid repellent layer does not include a cationic photopolymerization initiator and only the nozzle layer contains the initiator. It is believed that this phenomenon is that the acid generated from the cationic photopolymerization initiator in the nozzle layer by light irradiation can diffuse into the liquid repellent layer, so that the liquid repellent layer can also be cured. As an advantage of this embodiment, the curing of the liquid repellent layer occurs only at the portion where the nozzle layer is cured, so the conditions for nozzle patterning do not depend on the liquid repellent layer. That is, there is no need to consider the photosensitive difference between the liquid repellent layer and the nozzle layer. In general, it is difficult to completely match the photosensitive characteristics of two or more photosensitive resin layers.

Next, the composition material of the liquid repellent layer used in the present invention will be described in detail.

As the hydrolyzable silane compound having a fluorine-containing group, an alkoxysilane having a fluorinated alkyl group represented by the following general formula (1) is suitably used.

R _f Si (R) _b X _(3-b)

_Wherein R _f is a non-hydrolyzable substituent having 1 to 30 fluorine atoms bonded to a carbon atom, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, b is 0 to 2, preferably Zero or one, in particular zero.

Particularly preferred substituents R _f are CF ₃ (CF ₂ ) _n -Z-, wherein n and Z are as defined in formula (4) below.

CF ₃ (CF ₂ ) _n -Z-SiX ₃

Wherein X is as defined in Formula 1, preferably methoxy or ethoxy, Z is a divalent organic group, n is 0 to 20, preferably 3 to 15, more preferably Preferably an integer from 5 to 10, Z preferably contains up to 10 carbon atoms, Z is more preferably a divalent alkylene or alkyleneoxy group having up to 6 carbon atoms, such as methylene, Ethylene, propylene, butylene, methyleneoxy, ethyleneoxy, propyleneoxy and butyleneoxy, most preferably ethylene.

Examples of the compound of Formula 4 include the following compounds, but the present invention is not limited thereto.

CF ₃ -C ₂ H ₄ -SiX ₃

C ₂ F ₅ -C ₂ H ₄ -SiX ₃

C ₄ F ₉ C ₂ H ₄ -SiX ₃

C ₆ F ₁₃ -C ₂ H ₄ -SiX ₃

C ₈ F ₁₇ -C ₂ H ₄ -SiX ₃

C ₁₀ F ₂₁ -C ₂ H ₄ -SiX ₃

X is a methoxy group or an ethoxy group. The said condensation product is manufactured using 2 or more types of hydrolysable silanes which have a fluorine-containing group, and the said silanes differ in the number of fluorine atoms containing.

For example, C ₆ F ₁₃ -C ₂ H ₄ -SiX ₃ , C ₈ F ₁₇ -C ₂ H ₄ -SiX _3, and C ₁₀ F ₂₁ -C ₂ H ₄ -SiX ₃ are used simultaneously. The fluorine-containing groups tend to be arranged on the surface of the liquid repellent layer. Since the fluoride concentration on the surface is higher in the presence of fluoro-alkyl groups of different lengths as compared to the case where all fluoro-alkyl groups have the same length, the inventors have found that liquid repellency, wiping resistance and recording liquid resistance are I found improvement. The reason for this phenomenon is not clear, but because fluoro-alkyl groups are linear and optimally arranged on the surface for the high electron density repulsion of fluorine atoms, fluoro-alkyl groups of different lengths may naturally be present at higher densities. It seems to be because there is.

Subsequently, examples of the silane compound having a cationically polymerizable group are represented by the following general formula (2).

R _c -Si (R) _b X _(3-b)

In the above formula, R _c is a non-hydrolyzable substituent having a cationically polymerizable group, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, and b is an integer of 0 to 2.

As the cationically polymerizable organic group, a cyclic ether group, a vinyl ether group and the like represented by an epoxy group and an oxetane group can be used. From the viewpoint of availability and reaction control, an epoxy group is preferable.

More specifically, glycidoxy propyl trimethoxysilane, glycidoxy propyl triethoxy silane, epoxy cyclohexyl ethyl trimethoxysilane, epoxy cyclohexyl ethyl triethoxy silane, etc. are mentioned.

The invention is not limited to these compounds.

In the present invention, the liquid repellent layer consists of a cured condensation product comprising a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group. More preferably, in addition to the hydrolyzable silane compound having a fluorine-containing group and the hydrolyzable silane compound having a cationically polymerizable group, the cured condensation product includes an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. The alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound is useful for controlling physical properties of the liquid repellent layer.

Examples of the alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound are represented by the following general formula (3).

R _a -SiX _(4-a)

In the above formula, R _a is a non-hydrolyzable substituent selected from a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, X is a hydrolyzable substituent, and a is an integer of 0 to 3.

Specifically, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri Propoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysilane, diphenyldiethoxy Silane, dimethyldimethoxy silane, dimethyldiethoxysilane and the like. The invention is not limited to these compounds.

The composition of the condensation product, that is, the compounding ratio of the hydrolyzable silane compound having a fluorine-containing group which is a constituent of the present invention, the hydrolyzable silane compound having a cationically polymerizable group, and an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound depending on the application It is determined appropriately. The addition amount of the hydrolyzable silane compound having a fluorine-containing group is preferably 0.5 to 20 mol%, more preferably 1 to 10 mol%. When the addition amount is small, sufficient liquid repellency is not obtained, and when the addition amount is high, a homogeneous liquid repulsion layer is not obtained. If the uniformity of the surface of the liquid repellent layer is not sufficient, light is scattered at the surface of the liquid repellent layer. This is particularly undesirable when the liquid repellent layer is photosensitive.

Moreover, as for the compounding ratio of the hydrolyzable silane compound which has a cationically polymerizable group, and an alkyl substituted, aryl substituted, or unsubstituted hydrolysable silane compound, 10: 1-1:10 are preferable.

In general, in the liquid repellent layer of the ink jet head, it is preferable to have a substantially uniform flat surface. The non-uniform liquid repellent layer exhibits high liquid repellency (large advancing contact angle or high static contact angle) with respect to the recording liquid droplets. However, when the liquid repellent layer is rubbed with the recording liquid in a wiping operation or the like, the recording liquid remains in the recess, and as a result, the liquid repellency of the liquid repellent layer may deteriorate. This phenomenon is remarkable in the embodiment in which the recording liquid contains a pigment, i.e., colorant particles, because the colorant particles enter and adhere to the recesses. Therefore, the surface roughness Ra showing the nonuniformity of the liquid repellent layer is preferably less than 5.0 nm, more preferably Ra is less than 1.0 nm. In order to form a liquid repellent layer having a flat surface, the present invention controls the amount of hydrolyzable silane compound having a fluorine-containing group, and appropriately adjusts the amount of alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound.

The liquid repellent layer of the present invention is formed on a nozzle by curing a condensation product of a hydrolyzable silane compound having a fluorine-containing group, a hydrolyzable silane compound having a cationically polymerizable group, and, if necessary, an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. Is formed.

The hydrolyzable condensation product is prepared by the hydrolysis reaction of a hydrolyzable silane compound having a fluorine-containing group in the presence of water, a hydrolyzable silane compound having a cationically polymerizable group, and, if necessary, an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. .

Condensation degree of a product can be suitably adjusted with the temperature, pH, etc. of a condensation reaction. It is also possible to adjust the degree of condensation as a result of the hydrolysis reaction using a metal alkoxide as a catalyst of the hydrolysis reaction. As metal alkoxides, aluminum alkoxides, titanium alkoxides, zirconium alkoxides and their complexes (acetyl acetone complexes and the like) are mentioned.

Also mentioned as cation photopolymerization initiators are onium salts, borate salts, compounds having imide structures, compounds having triazine structures, azo compounds or peroxides. Aromatic sulfonium salts or aromatic iodonium salts are preferred for sensitivity and stability.

Subsequently, an example of the ink jet head having the liquid repellent layer of the present invention will be described.

1A, 1B, 1C, and 1D are conceptual diagrams illustrating a method of manufacturing the ink jet head of the present invention.

First, FIG. 1A shows the liquid repellent layer 11 formed on the nozzle plate 12 which is a resin or an SUS plate.

The liquid repellent layer 11 is a condensation product produced by the hydrolysis reaction of a hydrolyzable silane compound having a fluorine-containing group, a hydrolyzable silane compound having a cationically polymerizable group, and, if necessary, an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. It is applied by spray coating, immersion coating or spin coating with a liquid containing and then cured by heat treatment or light irradiation. The thickness of the liquid repellent layer 11 is appropriately determined according to the use form, and the range thereof is preferably about 0.1 to 2 m. Subsequently, an ink discharge port is formed by a machining technique such as excimer laser processing, pulse laser processing and discharge processing on the nozzle plate on which the liquid repellent layer is formed (FIG. 1B).

Naturally, the liquid repellent layer can be cured after the ink discharge port 13 is formed. In addition, a protective film or the like can be appropriately arranged on the liquid repellent layer during the ink discharge port processing.

The above technique is a preferred embodiment because the liquid repellent material is not placed inside the ink discharge port because the nozzle plate and the liquid repellent layer can be processed comprehensively.

Subsequently, a substrate 14 (FIG. 1C) containing the ink discharge pressure generating element 15 and the flow path member 16 is manufactured. The ink jet head is completed by attaching the nozzle plate and the substrate 14 having the ink discharge port therein, through an adhesive layer if necessary.

Moreover, when using a photocurable substance as a nozzle plate in the said method, a nozzle plate can also be manufactured as follows.

The nozzle material 21 is formed on the base member 22 as shown in FIG. 2A. The liquid repellent layer 23 is a hydrolyzable compound prepared by hydrolysis reaction of a hydrolyzable silane compound having a fluorine-containing group, a hydrolyzable silane compound having a cationically polymerizable group, and, if necessary, an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. The liquid containing the condensation product is applied and formed on the nozzle material 21 (FIG. 2B). The nozzle material 21 and the liquid repellent layer 23 are cured using pattern exposure as shown in Fig. 2C, and the unexposed portions are developed and removed (Fig. 2D). After forming the nozzle with a liquid repulsion layer, it peels suitably from a parent member. Subsequently, a substrate in which the ink discharge pressure generating element and the flow path member are incorporated is manufactured. The ink jet head is completed by attaching a nozzle plate and a substrate having an ink discharge port therein, through an adhesive layer, if necessary.

Next, an embodiment of the present invention to be applied to the above-described method for producing an ink jet head described in Japanese Patent Application Laid-Open No. 06-286149 will be described.

The ink jet head manufacturing method

Forming an ink flow path pattern of a soluble resin material on a substrate on which an ink discharge pressure generating element is formed,

Applying a soluble coating resin on the soluble resin material layer as an ink flow path wall to form a coating resin layer,

Forming an ink discharge port in the coating resin layer and the liquid repellent layer on the ink discharge pressure generating element, and

Dissolving the soluble resin material layer

Wherein the liquid repellent layer contains a cured condensation product of a hydrolyzable silane compound having a fluorine containing group and a hydrolyzable silane compound having a cationic polymerizable group.

This will be described later using a conventional conceptual diagram.

3A is a perspective view of the substrate 31 on which the ink discharge pressure generating element 32 is formed. 3B is a cross-sectional view taken along 3B-3B of FIG. 3A. 3C is a diagram of a substrate on which an ink flow path pattern 33 is formed of a soluble resin material. In order to prevent the ink flow path pattern from collapsing even when the nozzle material layer is formed in the induction process, a positive resist, in particular a relatively high molecular weight photodegradable positive resist, is suitably used.

Subsequently, FIG. 3D shows that the coating resin layer 34 is formed on the ink flow path pattern.

The coating resin layer is a material which can be polymerized by light irradiation or heat treatment, and a cationic photopolymerizable resin is particularly suitable as the coating resin layer. 3E shows that the liquid repellent layer 35 is further formed on the coating resin layer.

The coating resin layer and the liquid repellent layer can be appropriately formed by spin coating, direct coating or the like. Direct coating is particularly suitably used for the formation of a liquid repellent layer. The coating resin layer includes a cationic initiator as an essential component, but the liquid repellent layer does not need to include the cationic initiator. The liquid repellent layer can be cured by an acid generated during curing of the coating resin layer. Subsequently, the pattern is exposed through a mask as shown in FIG. 3F and developed as shown in FIG. 3G to form the ejection opening 36. Further, only the liquid repellent layer can be partially removed except for the discharge port forming portion by appropriately setting the mask pattern and the exposure conditions. That is, when the mask pattern is below the limit, only the liquid repellent layer is partially removed. Limit resolution means the pattern size in which the coating resin layer is not developed on the substrate (FIGS. 3H and 3I).

As described above, the liquid repellent layer of the present invention has high liquid repellency and wiping resistance. Therefore, when performing the wiping operation, the recording liquid droplets to be removed can be rolled off and drawn to the discharge port. In conclusion, the recording liquid droplets may not be discharged.

In order to prevent this phenomenon, Japanese Patent Application Laid-Open No. 06-210859 proposes to establish a liquid repellent region and a non-liquid repellent region on the nozzle surface. As described above, the present invention can easily form a pattern which does not exist partially in the liquid repellent layer, and can prevent the ink from being discharged.

Subsequently, the ink supply opening 37 is appropriately formed in the substrate (FIG. 3J), and the ink flow path pattern 33 is dissolved (FIG. 3K). Finally, if necessary, heat treatment is used to completely cure the nozzle material and the photosensitive liquid repellent material and to complete the ink jet head. The drawing also described the case where a cationic photopolymerizable material is used as the coating resin layer.

Instead of removing the coating resin layer and the liquid repellent layer by pattern exposure after forming the liquid repellent layer, a discharge opening can be formed by using a thermosetting cationic polymerization material as the coating resin layer and using an excimer laser.

Synthesis Example 1

The hydrolytic condensation product was prepared according to the following procedure. 28 g (0.1 mol) of glycidylpropyltriethoxysilane, 18 g (0.1 mol) of methyltriethoxysilane, 6.6 g of trideca fluoro-1,1,2,2-tetrahydrooctyltriethoxysilane 0.013 mol, corresponding to 6 mol% of the total amount of the hydrolyzable silane compound), 17.3 g of water, and 37 g of ethanol were stirred at room temperature, and then refluxed for 24 hours to obtain a hydrolyzable condensation product.

In addition, the condensation product was diluted with 2-butanol and ethanol to a nonvolatile content of up to 7% by weight to obtain a composition 1 that forms a liquid repellent layer.

Furthermore, 0.04 g of aromatic sulfonium hexafluoroantimonate salt (trade name: SP170, manufactured by Asahi Denka Kogyo KK) as a cationic photopolymerization initiator was added to 100 g of the composition 1 to form a liquid repellent layer. Composition 2 was obtained.

Synthesis Example 2

Tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane and heptadeca instead of 6.6 g of tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane in Synthesis Example 1 A hydrolysable condensation product was obtained using 4.4 g of a mixture of fluoro-1,1,1,2-tetrahydrodecyltriethoxysilane. All other conditions were the same.

In addition, the condensation product was diluted with 2-butanol and ethanol to a nonvolatile content of up to 7% by weight to obtain a composition 3 which forms a liquid repellent layer. Furthermore, 0.04 g of aromatic sulfonium hexafluoroantimonate salt (trade name: SP170, manufactured by Asahi Denka Kogyo Co., Ltd.) as a cationic photopolymerization initiator was added to 100 g of Composition 3 to obtain a composition 4 having a liquid repellent layer. .

(Example 1)

The compositions 2 and 4 were applied on a polyamide film by a roll coating method, the application solvent was dried at 90 ° C., and heated for 1 minute to form a coated film.

Subsequently, compositions 2 and 4 were exposed using a UV irradiation apparatus and heated at 90 ° C. for 4 minutes to cure. The curing reaction was terminated by heating at 200 ° C. for 1 hour in a heating oven to form a liquid repellent layer. Subsequently, the liquid repellency was evaluated by measuring the contact angle with respect to the ink jet ink using an automatic contact angle measuring instrument (Kyowa Interface Science, CA-W). Hereinafter, θa means a receding contact angle and θr means a forward contact angle. According to the experiments of the inventors, the higher the contact angle with respect to the ink, in particular, the backward contact angle which has a strong influence on the removal of the ink from the nozzle surface by wiping, the higher. The results are shown in Table 1 below.

Record amount Ink BCI-3Bk Ink BCI-8Bk θa θr θa θr Liquid repellent layer 2 85 ° 75 ° 90 ° 78 ° Liquid repellent layer 4 89 ° 80 ° 95 ° 83 °

Here, BCI-3Bk, available from Canon, is a neutral pigment ink with a surface tension of about 40 mN / m, and BCI-8Bk, available from Canon, is an alkaline dye ink with a surface tension of about 42 mN / m. .

Subsequently, the polyamide film on which the liquid repellent layer was formed was immersed in BCI-3Bk and 8Bk inks at 60 ° C. for 4 weeks to test the ink resistance of the liquid repellent layer. The results are shown in Tables 2 or 3 below.

Results for BCI-3Bk Ink Recording liquid (BCI-3Bk ink) First step After soaking for 4 weeks θa θr θa θr Liquid repellent layer 2 85 ° 75 ° 71 ° 61 ° Liquid repellent layer 4 89 ° 80 ° 83 ° 69 °

Results for BCI-8Bk Ink Recording liquid (BCI-8Bk ink) First step After soaking for 4 weeks θa θr θa θr Liquid repellent layer 2 90 ° 78 ° 72 ° 56 ° Liquid repellent layer 4 95 ° 83 ° 84 ° 67 °

From the above results, the liquid repellent layer according to the present invention has a very large contact angle with respect to ink, that is, high liquid repellency.

In addition, sufficient liquid repellency is maintained even after immersion testing, assuming long term preservation.

In addition, even when the hydrolyzable condensation product is composed of two or more hydrolyzable silane compounds having different lengths of fluorinated alkyl groups, the resistance to liquid repellency, especially alkali inks, is improved.

According to the method, an excimer laser was irradiated to a polyamide film having a liquid repellent layer on its surface to form an ink discharge port. Subsequently, as shown in FIGS. 1A, 1B, 1C, and 1D, a film was integrated on a substrate having an ink discharge pressure generating element and an ink flow path wall to obtain an ink jet head. The print quality of the ink jet head was highly precise.

(Example 2)

In this embodiment, an ink jet head was prepared according to the procedure shown in FIGS. 3A, 3B, 3C, 3D, 3E, 3F and 3G above.

First, a silicon substrate having an electrothermal conversion element as an ink discharge pressure generating element was prepared, and the coating film and polymethyl isopropenyl ketone (ODUR-1010, Tokyo Oka Kogyo Kabushiki Kaisha) were soluble. The resin material was applied by spin coating on this silicon substrate. Subsequently, after preliminary baking at 120 degreeC for 6 minutes, the pattern exposure of the ink flow path was performed by the mask aligner UX3000 (USHIO Electrical machinery).

The exposure time was 3 minutes, developed with methyl isobutyl ketone / xylene = 2/1, and washed with xylene.

The polymethyl isopropenyl ketone is a so-called positive resist that is decomposed by UV irradiation and dissolved in an organic solvent. The pattern of soluble resin material was formed in the unexposed part in the case of pattern exposure, and obtained the ink supply flow path pattern (FIG. 3C). The thickness of the soluble resin material layer after development was 20 µm. Subsequently, the cationic photopolymerizable coating resin shown in Table 4 below was dissolved in a methyl isobutyl ketone / xylene mixed solvent at a concentration of 55% by weight, which was applied by spin coating onto an ink flow path pattern formed of the above soluble resin material layer, Firing at 90 ° C. for 4 minutes. The thickness of the coating resin layer on the ink flow path pattern after repeating the above application and baking three times was 55 탆 (Fig. 3D).

Epoxy resin EHPE-3150 (Daicel Chemical) 100 parts additive 1,4-HFAB (Central Glass) 20 copies Cationic photopolymerization initiator SP172 (Asahi Tenka High School Kabushikiisha) Part 5 Silane coupling agent A187 (Nippon Unicar) Part 5 1,4-HFAB: (1,4-bis (2-hydroxyhexafluoroisopropyl) benzene)

Subsequently, composition 1 consisting of the hydrolyzable condensation product of the fluorine-containing silane compound was applied directly onto the coating resin layer by coating. Subsequently, upon prefiring at 90 ° C. for 1 minute, the layer thickness was 0.5 μm. Here, the cationic photopolymerization initiator is not included in the composition 1. Subsequently, pattern exposure of the ink ejection openings was performed using a mask aligner MPA600 super (Canon) (FIG. 3F).

After heating at 90 ° C. for 4 minutes, it was developed with methyl isobutyl ketone (MIBK) / xylene = 2/3 and washed with isopropyl alcohol to form an outlet pattern. While the coating resin layer was cured to form the ejection opening pattern, the layer of the composition 1 was cured except for the ejection opening by the cationic photopolymerization initiator in the coating resin layer. The pattern edges of the pattern were sharp (Figure 3G). Subsequently, an ink supply opening forming mask was properly arranged on the rear surface of the substrate, and an ink supply opening was formed by anisotropic etching of the silicon substrate. During the anisotropic etching of the silicon, the surface of the substrate on which the nozzle was formed was protected with a rubber film. After the anisotropic etching was completed, the rubber film was removed, and the UX3000 was used again to irradiate UV on the entire surface to decompose the soluble resin material layer to form an ink flow path pattern. Subsequently, the ink flow path pattern was dissolved by soaking in methyl lactate for 1 hour using ultrasonic waves. Subsequently, in order to completely cure the coating resin layer and the liquid repellent layer, a heating process was performed at 200 ° C. for 1 hour (FIG. 3K). Finally, the ink supply member was attached onto the ink supply opening to complete the ink jet head. The ink jet head obtained by the above method was filled with BCI-3Bk ink manufactured by Canon Inc., and an image was output, whereby a high quality image was obtained. Further, the forward contact angle of the ink jet head for the BCI-3Bk ink was 86 degrees and the backward contact angle was 65 degrees, demonstrating that the liquid repellent layer exhibits high liquid repellency. Subsequently, the surface roughness of the liquid repellent layer of the ink jet head was measured in contact mode with a scanning probe model microscope JSPM-4210. As a result, the surface roughness index Ra is 0.2 to 0.3 nm (injection area is 10 μm ² ), demonstrating that the liquid repellent layer forms a very flat and smooth surface. Subsequently, the wiping operation was performed 30,000 times with the HNBR rubber blade while spraying ink onto the nozzle surface of this ink jet head. After the wiping operation, an image of the same high quality as before the wiping was obtained, and excellent wiping durability was confirmed. In addition, the composition 3 was used as the liquid repellent layer instead of the composition 1, and the ink jet head was completed in the same manner. Even after the wiping operation was performed, the quality of the printed image did not change as before, and excellent wiping durability was confirmed.

According to the above results, the liquid repellent layer of the present invention can be applied onto the cationic photopolymerizable nozzle material and then pattern-exposed the nozzle material and the liquid repellent layer simultaneously to form a precise ejection opening structure and exhibit high liquid repellency. have. Thanks to the excellent wiping durability, high quality images can be obtained even after wiping.

Claims (34)

Has a member having a discharge opening, And the surface of the member includes a condensation product prepared from a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group different from the hydrolyzable silane compound having the fluorine-containing group. The method of claim 1 wherein the condensation product is prepared further comprising a hydrolyzable silane compound having at least one alkyl substituent, a hydrolyzable silane compound having at least one aryl substituent or a hydrolyzable silane compound having no non-hydrolyzable substituent. Inkjet head. The ink jet head according to claim 1 or 2, wherein the hydrolyzable silane compound having the fluorine-containing group is represented by the following formula (1). <Formula 1> R _f Si (R) _b X _(3-b) In the above formula, R _f is a non-hydrolyzable substituent having 1 to 30 fluorine atoms bonded to a carbon atom, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, and b is an integer of 0 to 2. The ink jet head of claim 3, wherein the non-hydrolyzable substituent R _f has five or more fluorine atoms bonded to carbon atoms. The ink jet head according to claim 3, wherein the hydrolyzable silane compound having the fluorine-containing group has two or more hydrolyzable silane compounds having fluorine-containing groups having different numbers of fluorine atoms. The ink jet head according to claim 1 or 2, wherein the hydrolyzable silane compound having a cationically polymerizable group is represented by the following formula (2). <Formula 2> R _c -Si (R) _b X _(3-b) In the above formula, R _c is a non-hydrolyzable substituent having a cationically polymerizable group, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, and b is an integer of 0 to 2. The ink jet head of claim 2, wherein the hydrolyzable silane compound having an alkyl substituent, an aryl substituent, or no non-hydrolyzable substituent is represented by the following formula (3). <Formula 3> R _a -SiX _(4-a) In the above formula, R _a is a non-hydrolyzable substituent selected from a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, X is a hydrolyzable substituent, and a is an integer of 0 to 3. The ink jet head according to claim 1 or 2, wherein the condensation product further contains a cationic initiator. The ink jet head of claim 8, wherein the cationic initiator causes polymerization by light irradiation. The ink jet head according to claim 1 or 2, wherein the surface is a discharge opening surface. delete The ink jet head according to claim 1 or 2, wherein the molar ratio of the hydrolyzable silane compound having the fluorine-containing group is 0.5 to 20 mol% based on the total amount of the hydrolyzable compound used. Applying a photopolymerizable liquid repellent layer on the photopolymerizable resin layer, and simultaneously performing pattern-exposure and development to form a nozzle surface having liquid repellency, wherein the photopolymerizable liquid repellent layer has a fluorine-containing group. And a condensation product made from a hydrolyzable silane compound having a hydrolyzable silane compound and a cationic polymerizable group. The method of claim 13, wherein the condensation product is further prepared by further comprising a silane compound represented by Formula 3 below. <Formula 3> R _a -SiX _(4-a) In the above formula, R _a is a non-hydrolyzable substituent selected from a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, X is a hydrolyzable substituent, and a is an integer of 0 to 3. The manufacturing method of the ink jet head of Claim 13 or 14 in which the said photopolymerizable resin layer is formed from a cationically polymerizable resin. 16. The method of claim 15, wherein the photopolymerizable resin layer contains a cationic initiator and the photopolymerizable liquid repellent layer does not contain a cationic initiator. 15. The part according to claim 13 or 14, wherein the photopolymerizable resin layer and the photopolymerizable liquid repellent layer are both pattern-exposed and developed at the same time, thereby being comprehensively removed from the photopolymerizable resin layer and the photopolymerizable liquid repellent layer, and photopolymerizable. Forming a portion to be removed only from the liquid repellent layer. 18. The method of claim 17, wherein the portion removed only from the photopolymerizable liquid repellent layer is formed by pattern-exposure below the limit resolution of the photopolymerizable resin layer. Forming an ink flow path pattern of a soluble resin material on the ink discharge pressure generating element on the substrate, Forming a polymerizable coating resin layer on the soluble resin material pattern, Forming a liquid repellent layer on the coating resin layer, Removing the coating resin layer and the liquid repellent layer on the ink discharge pressure generating element to form an ink discharge opening, Dissolving the soluble resin material pattern Wherein the liquid repellent layer contains a condensation product prepared from a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group. 20. The method of claim 19, wherein the condensation product is prepared further comprising an alkyl substituted, aryl substituted or unsubstituted hydrolyzable silane compound. The manufacturing method of the ink jet head of Claim 19 or 20 whose said polymeric coating resin layer is a photopolymerizable coating resin layer. The manufacturing method of the ink jet head of Claim 19 or 20 whose said polymeric coating resin layer is a cationically polymerizable coating resin layer. 21. The method of claim 19 or 20, wherein the polymerizable coating resin contains an epoxy compound that is solid at room temperature. 21. The method of claim 19 or 20, wherein the polymerizable resin layer contains a cationic initiator, and the liquid repellent layer does not contain a cationic initiator. 21. The method according to claim 19 or 20, wherein both the polymerizable resin layer and the liquid repellent layer are pattern-exposed and developed at the same time, thereby removing only the part which is comprehensively removed from the polymerizable resin layer and the liquid repellent layer, and only the liquid repellent layer. Forming a portion to be formed. The method of manufacturing an ink jet head according to claim 25, wherein the portion removed only from the liquid repellent layer is formed by pattern-exposure below the limit resolution of the polymerizable resin layer. The method for producing an ink jet head according to any one of claims 13, 14, 19 or 20, wherein the hydrolyzable silane compound having a fluorine-containing group is represented by the following formula (1). <Formula 1> R _f Si (R) _b X _(3-b) In the above formula, R _f is a non-hydrolyzable substituent having 1 to 30 fluorine atoms bonded to a carbon atom, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, and b is an integer of 0 to 2. 28. The method of claim 27, wherein the non-hydrolyzable substituent R _f has five or more fluorine atoms bonded to carbon atoms. A method for producing an ink jet head according to claim 27, wherein the hydrolyzable silane compound having the fluorine-containing group has two or more hydrolyzable silane compounds having a fluorine-containing group having a different number of fluorine atoms. The method for producing an ink jet head according to any one of claims 13, 14, 19 or 20, wherein the hydrolyzable silane compound having a cationic polymerizable group is represented by the following formula (2). <Formula 2> R _c -Si (R) _b X _(3-b) In the above formula, R _c is a non-hydrolyzable substituent having a cationically polymerizable group, R is a non-hydrolyzable substituent, X is a hydrolyzable substituent, and b is an integer of 0 to 2. delete 21. An ink jet head according to any one of claims 13, 14, 19, or 20, wherein the ejection opening is formed by pattern-exposure and development, followed by light irradiation or heat treatment to cure the liquid repellent layer. Manufacturing method. A liquid repellent material for an ink jet head, comprising a condensation product prepared from a hydrolyzable silane compound having a fluorine-containing group and a hydrolyzable silane compound having a cationically polymerizable group different from the hydrolyzable silane compound having a fluorine-containing group. An ink jet head according to claim 10, wherein a cured layer of liquid repellent material constitutes the discharge opening surface.

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