JP2006159764A - Inkjet head and method for manufacturing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head which hardly generates deformation of an orifice caused by absorption of an ink in an ink flow path constituting member even when a high alkali ink is used or an extremely small orifice is prepared, and is capable of stably delivering for a long time, and a method for manufacturing it. <P>SOLUTION: The inkjet head has an ink delivering port and an ink flow path communicated with the ink delivering port and capable of introducing the ink at a position where the ink delivering pressure generating element can act on a substrate on which the ink delivering pressure generating element is formed, and has at least the ink flow path formed by an ink flow path constituting member connected with the substrate. The ink flow path constituting member is formed of a cured article of a resin composition comprising an alkoxysilyl group-containing epoxy resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet head for generating recording liquid droplets used in an ink jet recording system.

  An ink jet head applied to an ink jet recording system (liquid jet recording system) is generally a fine recording liquid discharge port (hereinafter sometimes referred to as an orifice), a liquid flow path, and a liquid provided in a part of the liquid flow path. A plurality of discharge energy generating units are provided. Conventionally, as a method for producing such an ink jet head, for example, the following steps described in Patent Document 1 are known.

  First, an ink flow path pattern is formed of a soluble resin on a substrate on which an ink discharge pressure generating element is formed, and an epoxy resin and a photocationic polymerization initiator that serve as an ink flow path wall are formed on the ink flow path pattern. And forming an orifice in the coating resin layer located above the ink discharge pressure generating element by photolithography, and then eluting the soluble resin to form an ink flow path. The coating resin layer that becomes the road wall is cured.

  Examples of the epoxy resin contained in the coating resin serving as the ink flow path wall include epoxy resins having bisphenol A, F, and S skeletons described in Patent Document 2, and o-cresol novolac type epoxy resins. Moreover, the epoxy resin etc. which have the oxycyclohexane skeleton of patent document 3, patent document 4, patent document 5, and patent document 6 are known.

  By the way, with the recent progress of recording technology, higher-definition recording is required for inkjet recording technology. One method that satisfies this requirement is minimization of ink droplets ejected from the ink jet head, that is, miniaturization of the ink jet head. However, when an inkjet head having a minimal orifice is produced by a conventional manufacturing method, the influence of volume swelling due to ink absorption of the ink flow path constituting member that becomes the ink flow path wall cannot be ignored, and the orifice may be deformed. As a result, the ejection direction of the ejected ink droplets may vary, and the output image may be uneven.

  In addition, with the high demand for image recording by ink jet recording technology, the performance required for ink has also become high, and urea as a humectant has been contained in the ink. . Further, in order to improve the water resistance of the recorded matter, a poorly water-soluble dye is used as a coloring material, and an alkali salt is contained in the ink in order to dissolve this dye. As described above, when urea or an alkali salt is contained in the ink, the ink exhibits a relatively high alkalinity. However, the high alkali ink tends to swell the ink flow path constituent member as in the case of the polar solvent. Therefore, in the conventional ink jet produced by the above-described manufacturing method using a highly alkaline ink, the ink flow path is deformed due to the volume swelling due to the ink absorption of the ink flow path constituting member that becomes the ink flow path wall, and the desired discharge state May not be obtained, and the ink flow path wall constituting member may be peeled off from the substrate, which is not necessarily sufficient from the viewpoint of the reliability of the inkjet head.

As described above, the above-described inkjet manufacturing method has a technical problem of reducing the volume swelling due to ink absorption on the ink flow path wall when a very small orifice is formed or when a highly alkaline ink is used.
JP-A-6-286149 Japanese Patent Laid-Open No. 03-184868 Japanese Patent Laid-Open No. 60-161973 JP-A-63-221121 JP-A 64-92216 JP-A-2-140219

  The present invention solves the above-mentioned problems in the prior art, and even when a highly alkaline ink is used or when a very small orifice is produced, the orifice is not easily deformed by the ink absorbed by the ink flow path component, and is stable for a long time. It is an object of the present invention to provide an inkjet head that can perform the ejection and a method for manufacturing the inkjet head.

  As a result of diligent research to solve the above-described problems in the prior art and to achieve the above-mentioned problems, the present inventors have, for example, used epoxy resin having a hydroxyl group and an alkoxysilane compound as ink flow path constituent members in a conventional inkjet head. When an alkoxysilyl group-containing epoxy resin such as that obtained by condensation reaction is used, the volume swelling amount of the ink flow path component due to the ink absorption is reduced, and an inkjet head capable of desired stable ejection can be manufactured. I got the knowledge.

  In the alkoxysilyl group-containing epoxy resin, the alkoxysilyl group is condensed together with the ring-opening polymerization of the epoxy ring at the time of curing to form a siloxane bond in the cured product. The siloxane bond formed in the resin cured product is considered to impart excellent ink resistance, heat resistance, and high adhesion to a metal substrate to the cured product. That is, by using a resin composition containing an alkoxysilyl group-containing epoxy resin and introducing a siloxane bond formed by condensation of alkoxysilyl groups into the ink flow path component, the ink absorption amount is low, and as a result It has been found that the volume swelling amount of the cured resin can be reduced and the above-mentioned problems can be solved.

The present invention
On the substrate on which the ink discharge pressure generating element is formed, there are provided an ink discharge port, and an ink flow path that can communicate with the ink discharge port and can introduce the ink at a position where the ink discharge pressure generating element can act. An ink jet head in which at least the ink flow path is formed by an ink flow path constituting member bonded to the substrate,
The ink flow path constituent member includes a cured product of a resin composition containing an alkoxysilyl group-containing epoxy resin.

The present invention also provides:
(A) forming a pattern serving as an ink flow path with a soluble resin on a substrate on which an ink discharge pressure generating element is formed;
(B) forming a coating resin layer with an ink flow path constituent member on the substrate on which the pattern is formed;
(C) forming an ink discharge port in a coating resin layer located above the ink discharge pressure generating element;
(D) eluting the soluble resin to form an ink flow path;
A method for manufacturing an ink-jet head according to claim 1, wherein the ink flow path component contains a cured product of a resin composition containing an alkoxysilyl group-containing epoxy resin.

  According to the present invention, there is provided an inkjet head that is less likely to be deformed due to ink absorption of an ink flow path component member and can be stably ejected for a long time even when a high alkali ink is used or when a very small orifice is produced. It can be provided.

  The present invention relates to an ink discharge port on a substrate on which an ink discharge pressure generating element is formed, and an ink flow channel capable of introducing the ink to a position that communicates with the ink discharge port and can act on the ink discharge pressure generating element. And an ink jet head in which at least the ink flow path is formed by an ink flow path constituting member bonded to the substrate.

Moreover,
(A) forming a pattern serving as an ink flow path with a soluble resin on a substrate on which an ink discharge pressure generating element is formed;
(B) forming a coating resin layer with an ink flow path constituent member on the substrate on which the pattern is formed;
(C) forming an ink discharge port in a coating resin layer located above the ink discharge pressure generating element;
(D) eluting the soluble resin to form an ink flow path;
The present invention relates to a method of manufacturing an inkjet head having In particular, the present invention relates to a method for manufacturing an inkjet head in which the step (c) is performed by photolithography in order to obtain a higher-definition orifice (ink discharge port).

  In the present invention, the ink flow path constituent member in the ink jet head is formed of a cured product of a resin composition containing an alkoxysilyl group-containing epoxy resin.

  The alkoxysilyl group-containing epoxy resin in the present invention can be obtained, for example, by a condensation reaction between an epoxy resin having a hydroxyl group and an alkoxysilane compound. According to this condensation reaction, without opening the epoxy ring using a catalyst such as organic tin or organic acid tin, the hydroxyl group of the epoxy resin and the alkoxy group (or the hydroxyl group after hydrolysis) of the alkoxysilane compound are formed. It can be condensed and regioselectively chemically bonded.

  The alkoxysilane compound is preferably at least one of alkoxysilanes represented by the following general formula (1) and condensates thereof.

R ^a _q Si (OR ^b ) _4-q (1)
(In formula (1), q represents an integer of 0 to 2, R ^a represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 8 carbon atoms, and R ^b represents an alkyl having 1 to 4 carbon atoms. Group.)
In addition, when there are a plurality of R ^a and / or R ^b in one molecule, each is a group independently selected from the above. R ^a is preferably an alkyl group having 1 to 4 carbon atoms or a phenyl group. R ^b is preferably an alkyl group having 1 to 3 carbon atoms.

  Specific examples of the alkoxysilane compound include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane; methyltrimethoxysilane, methyltriethoxysilane, and methyltripropoxysilane. , Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyl Triethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, phenyl Trialkoxysilanes such as trimethoxysilane, phenyltriethoxysilane, 4-methylphenyltrimethoxysilane, 4-methylphenyltriethoxysilane, 4-ethylphenyltrimethoxysilane, 4-ethylphenyltriethoxysilane; dimethyldimethoxysilane , Dimethyldiethoxysilane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane , Di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-octyl Methoxysilane, di-n-octyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, bis (4-methylphenyl) dimethoxysilane, bis (4-methylphenyl) diethoxysilane, bis (4-methylphenyl) dimethoxy Examples thereof include, but are not limited to, dialkoxysilanes such as silane and bis (4-methylphenyl) diethoxysilane; or partial condensates thereof. Tetraalkoxysilanes, trialkoxysilanes, and partial condensates thereof are preferable. These can also be used independently and can also be used combining the plurality selected suitably.

  Moreover, the epoxy resin which has a hydroxyl group will not be specifically limited if it is an epoxy resin containing the hydroxyl group condensable with an alkoxysilane compound.

  The amount of the alkoxysilane compound used in the condensation reaction between the epoxy resin having a hydroxyl group and the alkoxysilane compound as described above is 5% by mass to 50% by mass with respect to the total of the epoxy resin having a hydroxyl group and the alkoxysilane compound. % Is preferred. That is, if it is less than 5% by mass, the desired ink resistance may not be obtained. If it exceeds 50% by mass, the cured product becomes brittle due to an increase in the number of siloxane bonding sites condensed in the cured product. There is a risk that.

  In addition to the above alkoxysilyl group-containing epoxy resin, other epoxy resins can be used in combination with the resin composition used in the present invention.

  The resin composition used in the present invention preferably further contains a photocationic polymerization initiator. By using such a resin composition, a photolithography technique can be used when forming ink discharge ports in the ink flow path constituting member. As the cationic photopolymerization initiator, aromatic iodonium salt, aromatic sulfonium salt, SP-150, SP-170, SP-172 (trade name) marketed by Asahi Denka Kogyo, and Rhodia are marketed. Rhodorsil 2074 (trade name) and the like. These cationic photopolymerization initiators can initiate cationic polymerization by irradiation with ultraviolet rays. The photocationic polymerization initiator is preferably used in an amount of 0.5 to 10% by mass with respect to 100% by mass of the resin component contained in the resin composition.

  Moreover, it is possible to add an additive etc. to said resin composition suitably as needed. For example, a flexibility imparting agent may be added for the purpose of lowering the elastic modulus of the cured product, or a silane coupling agent may be added to obtain further adhesion to the substrate. The amount of the additive can be set as appropriate so that the target effect can be exhibited.

(Experimental example 1)
In this experimental example, a pattern is formed on a substrate with an alkoxysilyl group-containing epoxy resin and a resin composition in which part or all of the alkoxysilyl group-containing epoxy resin is replaced with another epoxy resin, and the resin is subjected to an acceleration test. An experiment was conducted to confirm the amount of change in pattern width due to volume swelling by ink absorption of the cured product.

First, a 6-inch Si wafer was prepared as a substrate, and a 1.0 μm SiO ₂ layer was formed by thermal oxidation. Next, using the resin compositions (1) to (4) and (c1) described in Table 1 dissolved in a suitable solvent (methyl isobutyl ketone), a resin composition layer is formed on the substrate by spin coating. The coating solvent was evaporated by baking at 90 ° C. for 5 minutes to obtain a resin composition layer having a thickness of 20 μm.

Next, using a Canon mask aligner MPA600 (trade name), patterning of the resin composition layer on the substrate with an exposure amount of 3000 mJ / cm ² (line and space pattern with a length of 5 cm and a width of 50 μm) was performed on the hot plate after exposure. The film was developed with a methyl isobutyl ketone / xylene mixed solvent after heating at 90 ° C. for 4 minutes, and further heated at 200 ° C. for 1 hour after the development for main curing. Thus, a line & space pattern having a length of 5 cm and a width of 50 μm was formed.

  Next, these samples were immersed in a highly alkaline ink having a pH of 10 consisting of ethylene glycol / urea / isopropyl alcohol / black dye / water and subjected to a pressure cooker (PCT) test (121 ° C., 2 atm, 100 hours). The pattern change was observed. The reason why this acceleration test was performed during ink immersion was that ink resistance when used as an ink flow path constituent member was also taken into consideration.

  After completion of the PCT test, the sample was washed with water and blown dry, and then the line pattern width was measured. The line width increase rate in the line & space pattern produced with the resin compositions (1) and (2) was 2%. there were. Moreover, the increase rate of the line width in the line & space pattern produced with the resin compositions (3) and (4) was 4%. On the other hand, the increase rate of the line width in the line & space pattern produced with the resin composition (c1) was 10%. In all samples, the line & space pattern was in close contact with the substrate after the PCT test was completed.

  From this result, it was confirmed that the cured product of the resin composition containing the alkoxysilyl group-containing epoxy resin is an excellent material having a low volume swelling due to ink absorption and good adhesion to the substrate.

  The numerical value in a table | surface represents a mass part. Abbreviations in the table are as follows.

EHPE-3150: Product name SP-172 manufactured by Daicel Chemical Industries, Ltd. Product name A-187 manufactured by Asahi Denka Kogyo Co., Ltd. Product name manufactured by Nihon Unicar Co., Ltd. In addition, alkoxy group-containing silane-modified bisphenol A type epoxy which is epoxy resin (I) The resin can be easily synthesized by dissolving and mixing methyltrimethoxysilane in a general bisphenol A type epoxy resin and then performing a demethanol reaction under a tin catalyst. Epoxy resin (II), an alkoxy group-containing silane-modified alicyclic epoxy resin, can be easily synthesized by dissolving and mixing methyltrimethoxysilane with an alicyclic epoxy resin having a hydroxyl group, followed by demethanol reaction under a tin catalyst. can do. Epoxy resin (III) is marketed by US Shell Chemical Company as EPON-SU-8 (trade name).

(Examples 1-4 and Comparative Example 1)
As Examples 1 to 4 and Comparative Example 1, the resin compositions described in Table 1 (Examples 1 to 4: resin compositions (1) to (4), Comparative Example 1: resin composition (c1)) were used as inks. An ink jet head having a minimal orifice was prepared by using the following manufacturing method as a flow path component, and the influence of volume swelling due to ink absorption on orifice shape stability was evaluated. Hereinafter, description will be given with reference to the drawings.

  As shown in FIG. 1, an electrothermal conversion element (TaN) is disposed as an ink discharge pressure generating element 2 on a Si wafer substrate 1 having a crystal axis (100) provided with an ink supply port forming mask 3 on the back surface, and further protection is provided. A SiN layer 4 and a Ta layer 5 were formed as layers. The ink discharge pressure generating element 2 is connected to a control signal input electrode for operating the element (not shown). FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG. 1.

Next, a layer made of polyetheramide was formed on the substrate 1 as an adhesion layer 6 with a thickness of 2.0 μm by the following method. The polyether amide layer was applied to the substrate 1 with a spinner using Hitachi Chemical's HIMAL1200 (trade name), and baked at 100 ° C./30 minutes + 250 ° C./1 hour. Next, a resist layer of a positive resist OFPR800 (trade name) manufactured by Tokyo Ohka Kogyo Co., Ltd. was formed on the adhesion layer 6 and patterned. Further, the adhesion layer 6 was patterned by O ₂ plasma ashing using the resist pattern as a mask, and finally the resist pattern used as the mask was peeled to form the adhesion layer 6 as shown in FIG.

  Next, as shown in FIG. 4, an ink flow path pattern was formed on the substrate 1 using a positive resist ODUR (trade name) manufactured by Tokyo Ohka Kogyo Co., Ltd. (thickness: 12 μm).

  Furthermore, the coating resin layer 8 is formed on the substrate 1 by using the resin compositions (1) to (4) and (c1) described in Table 1 dissolved in an appropriate solvent (methyl isobutyl ketone). A tiny orifice 9 (ink ejection port, diameter 8 μm) was formed by photolithography (see FIG. 5).

Next, the back surface of the substrate 1 was etched by Si anisotropic etching to form an ink supply port 10. (See Figure 6)
Next, in order to completely remove the SiN film on the ink supply port 10 and the ink flow path pattern 7 and to completely cure the resin composition constituting the coating resin layer 8 that becomes the ink flow path wall, 200 ° C./1 hour. Heating was performed to obtain an inkjet head (see FIG. 7).

  Next, when 10,000 test prints were performed with the above-described high alkali ink with the produced inkjet head, the inkjet head of Comparative Example 1 produced some image disturbance. On the other hand, in the inkjet heads of Examples 1 to 4, image disturbance did not occur.

  As described above, the cured product of the resin composition containing an alkoxysilyl group-containing epoxy resin used in the present invention has less volume swelling due to ink absorption, and a highly reliable ink jet head by using it as an ink flow path constituent member. It can be seen that

It is a perspective view which shows the structure of the board | substrate used for manufacture of the inkjet head of this invention. It is sectional drawing of the board | substrate of FIG. It is sectional drawing of the state which formed the contact | adherence layer in the board | substrate of FIG. FIG. 4 is a cross-sectional view of a state where an ink flow path pattern is formed on the substrate of FIG. 3. It is sectional drawing of the state which formed the coating resin layer in the board | substrate of FIG. 4, and formed the minimum orifice. FIG. 6 is a cross-sectional view of a state where an ink supply port is formed on the back surface of the substrate of FIG. 5. It is sectional drawing which shows the structure of the inkjet head of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Ink discharge pressure generating element 3 Ink supply port forming mask 4 SiN layer 5 Ta layer 6 Adhesion layer 7 Ink flow path pattern 8 Covering resin layer 9 Ink discharge port 10 Ink supply port

Claims (8)

On the substrate on which the ink discharge pressure generating element is formed, there are provided an ink discharge port, and an ink flow path that can communicate with the ink discharge port and can introduce the ink at a position where the ink discharge pressure generating element can act. An ink jet head in which at least the ink flow path is formed by an ink flow path constituting member bonded to the substrate,
The ink-jet head, wherein the ink flow path constituent member contains a cured product of a resin composition containing an alkoxysilyl group-containing epoxy resin.   2. The inkjet head according to claim 1, wherein the alkoxysilyl group-containing epoxy resin is an alkoxysilyl group-containing epoxy resin obtained by a condensation reaction of an epoxy resin having a hydroxyl group and an alkoxysilane compound. The inkjet head according to claim 2, wherein the alkoxysilane compound is at least one of alkoxysilanes represented by the following general formula (1) and condensates thereof.
R ^a _q Si (OR ^b ) _4-q (1)
(In formula (1), q represents an integer of 0 to 2, R ^a represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 8 carbon atoms, and R ^b represents an alkyl having 1 to 4 carbon atoms. Group.) (A) forming a pattern serving as an ink flow path with a soluble resin on a substrate on which an ink discharge pressure generating element is formed;
(B) forming a coating resin layer with an ink flow path constituent member on the substrate on which the pattern is formed;
(C) forming an ink discharge port in a coating resin layer located above the ink discharge pressure generating element;
(D) eluting the soluble resin to form an ink flow path;
An ink jet head manufacturing method, wherein the ink flow path constituent member contains a cured product of a resin composition containing an alkoxysilyl group-containing epoxy resin.   5. The method for producing an ink jet head according to claim 4, wherein the alkoxysilyl group-containing epoxy resin is an alkoxysilyl group-containing epoxy resin obtained by a condensation reaction between an epoxy resin having a hydroxyl group and an alkoxysilane compound. The method for manufacturing an ink jet head according to claim 5, wherein the alkoxysilane compound is at least one of alkoxysilanes represented by the following general formula (1) and condensates thereof.
R ^a _q Si (OR ^b ) _4-q (1)
(In formula (1), q represents an integer of 0 to 2, R ^a represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 8 carbon atoms, and R ^b represents an alkyl having 1 to 4 carbon atoms. Group.)   The method for manufacturing an ink jet head according to claim 4, wherein the resin composition further contains a photocationic polymerization initiator.   8. The method of manufacturing an ink jet head according to claim 4, wherein the step (c) is performed by photolithography.

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