KR20070017916A - Method for Producing Liquid Ejecting Recording Head - Google Patents

Abstract

Disclosed is a liquid discharge recording head having improved working reliability. The first coating resin layer of the ink jet recording head having a liquid flow duct and a liquid discharge orifice is formed of an oxetane resin composition containing an oxetane compound having at least one oxetanyl group in one molecule and a cationic photopolymerization initiator as essential components.

Ink jet recording head, liquid discharge recording head, printer, oxetane, resin composition

Description

Method for Producing Liquid Ejection Recording Head {Method for Producing Liquid Ejecting Recording Head}

1 is a perspective view of an ink jet recording head according to an embodiment of the present invention.

2 is a cross-sectional view of the ink jet recording head.

3A and 3B show an ink jet recording head, FIG. 3A is a sectional view showing a state where bubbles are generated in the emission energy generating device, and FIG. 3B is a sectional view showing a state where ink is ejected from the nozzle.

4 is a sectional view of a substrate on which an ink ejection energy generating device has already been provided;

Fig. 5 is a sectional view showing a state in which an ink flow duct pattern is formed on a substrate with soluble resin.

6 is a cross-sectional view showing a state in which a first coating resin layer is formed in an ink flow duct pattern.

7 is a cross-sectional view showing a state in which an activation energy ray is irradiated to the first coating resin layer.

8 is a cross-sectional view showing a state in which a first coating resin layer is formed by patterning.

Fig. 9 is a cross-sectional view showing a state in which an ink flow duct pattern and a substrate having a first coating resin layer on top thereof are cut by a dicer;

10 is a cross-sectional view showing a state in which an ink flow duct pattern is formed and a soluble resin is dissolved.

<Explanation of symbols for the main parts of the drawings>

1: ink jet recording head 2: joint flow duct

3: ink supply member 3a: recess

4: first base material 4a: ink discharge energy generating device

4b: Regulating Circuit 5: Individual Flow Paths

6: nozzle 7: first coating resin layer

7a: discharge surface 8: second base material

9: second coating resin layer 10: top plate

11: ink supply orifice 12: ink flow duct pattern

13: patterning mask 14: activating energy rays

15: dicer b: bubble

i: ink

This application claims priority to Japanese Patent Application No. 2005-229864, filed August 8, 2005 with the Japan Patent Office, the entirety of which is incorporated herein.

The present invention relates to a method of manufacturing a liquid ejecting type recording head which exhibits a high resistance to chemicals and a low stress, and comprises a plurality of flow ducts formed with high precision, for example, by pattern molding by ultraviolet irradiation.

Among the liquid discharge type recording heads is, for example, an ink jet recording head applied to an ink jet recording system (liquid jet recording system) for ejecting ink as a liquid phase. Such an ink jet recording head has a number of constituent devices, that is, a plurality of ejection orifices for ejecting ink in a finely divided form, a plurality of flow ducts in communication with these ejection orifices, and a plurality of inks provided in certain portions of the flow ducts. And a discharge pressure generating device. In order to produce a high quality image with such an ink jet recording head, it is preferable that a small ink droplet discharged from the discharge orifice is always discharged from each discharge orifice at the same volume and at the same discharge rate.

Among the ink jet recording heads which realize these discharge conditions, for example, Patent Publication 1 (Japanese Patent Publication No. 56-123869), Patent Publication 2 (Japanese Patent Publication No. 57-208255), and Patent Publication 3 (Japanese Patent Publication No. 57-208256). In the ink jet recording heads disclosed in the above-mentioned patent publications 1 to 3, a plurality of nozzles each comprising an ink flow duct and an orifice portion is formed on a substrate carrying a plurality of ink discharge pressure generating devices, for example, a photosensitive resin material or Patterned with photoresist. A lid formed, for example by a glass plate, is joined on the component part carrying the ink flow duct and the orifice part. Examples of photosensitive resin materials or photoresists are dimers using diazo resins, p-diazoquinones, photo-polymerized photopolymers containing vinyl monomers and polymerization initiators such as polyvinyl cinnamates and photosensitizers. Embodied photosensitive polymers, mixtures of orthoquinone diazide and phenol novolak resins, and mixtures of polyvinyl alcohol and diazo resins. Other examples include polyether photosensitive polymer obtained from copolymerization of benzophenone or glycidyl chalcone with 4-glycidyl ethylene oxide, NN-dimethyl methacrylamide-acrylamide benzophenone copolymer, unsaturated polyester photosensitive resin, unsaturated The photosensitive composition obtained by mixing a urethane type photosensitive resin and a photoinitiator and a polymer with a bifunctional acrylic monomer is contained. Further examples include dichromate photoresists, non-chrome based water soluble photoresists, and polyvinyl cinnamate based photoresists.

Another ink jet recording head that satisfies the above conditions for ejection can be exemplified by the ink jet recording head obtained by the manufacturing method disclosed in Patent Publication 4 (Japanese Patent Publication No. 61-154947) shown below. In the method of manufacturing an ink jet recording head disclosed in Patent Publication No. 4, a plurality of ink flow duct patterns are formed on a substrate site, and these are ink flow ducts together with soluble resin, and the ink flow duct patterns thus formed are made of epoxy resin. Coated. Subsequently, the substrate is cut and the soluble resin forming the ink flow duct pattern is dissolved and removed to yield an ink jet recording head.

Further, in contrast to those shown in Patent Publications 1 to 4, as the ink ejection pressure generating device, a plurality of electric heat transducers are mounted facing the ejection orifices, and the growth direction of bubbles formed on the electric heat transducers is substantially the ink jet ejection direction. There is also the same ink jet recording head as. Examples of this type of ink jet recording head are disclosed in Patent Publications 5 (Japanese Patent Laid-Open No. 58-8658) and Patent Publication 6 (Japanese Patent Laid-Open No. 62-264957) shown below. In the ink jet recording head disclosed in the above-mentioned patent publication 5, the dry film, which later becomes an orifice plate, is bonded together with another patterned dry film on a substrate provided with an electric heat converter. A plurality of discharge orifices are formed by photolithography techniques in the place where they later become orifice plates facing the electric thermal transducers of the dry film. In the ink jet recording head disclosed in the above-mentioned patent publication 6, the substrate accompanying the ink discharge pressure generating device and the orifice plate produced by electrical casting are joined together through a patterned dry film.

In addition, in the ink jet recording head, it is necessary not only to eject the ink at the same volume and the same ejection speed through the ejection orifice, but also to eject the fine ink droplets at the precisely set position. In order for the ink jet recording head to eject ink at a precisely set position, it is preferable that the distance between the electric heat converter and the discharge orifice, which is referred to below as the 'OH' interval, is as short as possible.

An exemplary method for producing an ink jet recording head in which the OH interval is set to high precision is disclosed in Patent Publication 7 (Japanese Patent Laid-Open No. 6-286149). Patent Document 7 discloses a method of manufacturing an ink jet recording head comprising an ink flow duct pattern forming step, a coating resin layer forming step, and a soluble resin layer dissolving step. In the ink flow duct pattern forming step, an ink flow duct pattern, which later becomes an ink flow duct, is formed by the soluble resin on the substrate already carrying the ink discharge pressure generating device. In the step of forming the coating resin layer, the coating resin containing the epoxy resin that is solid at ambient temperature is dissolved in the solvent and applied with a solvent coating on the soluble resin layer forming the ink flow duct pattern, which is then flowed onto the soluble resin layer. A layer of coating resin is formed that is the wall region of the duct. In the resin layer dissolving step, the soluble coating layer forming the ink flow duct pattern is dissolved. In the manufacturing method of the ink jet recording head described in the above Patent Publication 7, the cationic polymer of the alicyclic epoxy resin is used as the coating resin in view of forming a high aspect ratio and securing high resistance to ink.

In the ink jet recording heads disclosed in the above-mentioned patent publications 1 to 4, a plurality of heater resistors provided in a predetermined portion of the ink flow duct to be the ink discharge pressure generating device are mounted along a line parallel to the ink flow direction. An ink ejection orifice is provided at the end of the ink flow duct to extend perpendicular to the ink flow direction. In this type of ink jet recording head, since the ink ejection orifices are disposed substantially perpendicular to the line of the heater resistor, the ink ejection direction is perpendicular to the growth direction of the bubbles on the resistor heater, i.e., the growth direction of the bubbles is It is different from the discharge direction of the ink.

In the ink jet recording head, since the portion of the discharge orifice disposed at the distal end of the ink flow duct is formed by the distal end of the substrate, the distance between the ink discharge pressure generating device and the discharge orifice is set as a result of cutting the substrate. Therefore, when adjusting the distance between the ink ejection pressure generating device and the ejection orifice, the precision when the substrate is cut is important. The operation of cutting the substrate uses a mechanical device such as a dicing saw. However, it is difficult to achieve the desired high precision with such a mechanical device.

In the ink jet recording heads disclosed in Patent Publications 5 and 6, the orifice plate has a thin thickness of, for example, 20 μm or less. In addition, it is difficult to produce orifice plates with uniform thickness. Even if the orifice plate is manufactured, it is very difficult to bond the orifice plate to the substrate already involving the ink discharge pressure generating device because of the brittleness of the orifice plate.

On the other hand, in the ink jet recording head, the following problems are newly faced by using the methods and materials disclosed in the above-mentioned patent publications 7 and 8 (Japanese Patent Laid-Open No. 7-214783).

The cured cationic polymer of the alicyclic epoxy resin has a high binding force to the underlying substrate. However, the polymer has a high internal stress and is therefore likely to peel off from the underlying substrate. In addition, the polymer is liable to crack (film breakage) at corners where stress is likely to be concentrated, which severely impairs the reliability of the ink jet recording head. In addition, among the materials disclosed in the above patent publications, there are many materials in which the patterning performance is insufficient, and thus the sophisticated patterning performance required for the ink jet recording head structure cannot be achieved.

In ink jet recording heads, especially when the resin layer is of extended length, or when the thickness of the coating resin layer serving as the ink flow duct wall zone is thicker, or when the ink flow duct exhibits a difficult or complex structure, the coating resin The layer tends to peel off or crack. In addition, in the ink jet recording head, in order to maintain the print quality, it may be necessary to clean the surface of the head from which the ink is ejected to remove the excess ink adhering to the recording head. When cleaning the ink jet recording head, the head surface is wiped with the cleaning member. Accordingly, a mechanical load is applied to the head surface, and as a result, the coating resin layer tends to peel off from the substrate.

Therefore, it is desirable to provide a method of manufacturing a liquid discharge recording head having a low stress coating film, for example, capable of accurate and easy pattern molding by ultraviolet irradiation.

It is an object of the present invention to provide a liquid ejecting recording head and a manufacturing method thereof without the above-mentioned problems of the prior art.

According to an embodiment of the present invention, a method of manufacturing a liquid discharge recording head is provided. The method includes forming a liquid flow duct pattern from soluble resin in a portion of the substrate followed by a liquid discharge energy generating device, which subsequently becomes a liquid flow duct. The method also includes forming a coated resin layer of soluble resin having a liquid flow duct pattern formed therein, forming a liquid discharge opening in a portion of the coated resin layer overlying the liquid discharge energy generating device, and dissolving the soluble resin. Steps. The coating resin layer is formed of an oxetane resin composition containing, as a necessary component, an oxetane compound having at least one oxetanyl group in one molecule and a cationic photopolymerization initiator. In the step of forming the coated resin layer, a solution of the raw material component of the oxetane resin composition and the cationic photopolymerization initiator dissolved in a solvent which does not dissolve the soluble resin is used, and a cured product of the raw material component of the solution is produced. The soluble resin dissolves out of the liquid discharge opening to form a liquid flow duct in communication with the liquid discharge opening.

According to the invention in which the coated resin layer forming the liquid flow duct and liquid discharge orifice of the liquid discharge recording head is formed of an oxetane resin composition, the stress of the coated resin layer is reduced, so that the substrate of the coated resin layer is cracked. And peeling can be prevented. This makes the liquid discharge recording head show better durability. In addition, according to the present invention, chemical resistance is obtained by forming a coated resin layer of an oxetane resin composition. Thus, according to the present invention, it is possible to obtain a liquid discharge recording head which has improved production yield and product quality and shows high reliability for an extended period of time.

A method of manufacturing a liquid discharge recording head according to one embodiment of the present invention will be described with reference to the drawings. The liquid discharge recording head is provided in an ink jet printer adapted to discharge ink (i), for example, as a liquid phase. 1 and 2, the ink jet recording head 1 is formed of an ink supply member 3 having a recess 3a that forms part of a cavity flow duct 2, and an ink supply member 3; The recess 3a comprises the first substrate 4 provided on one side. The ink jet recording apparatus 1 is also provided with a plurality of individual flow paths 5 and a plurality of nozzles 6, the first coating resin layer 7 formed on the first substrate 4, and the first substrate 4 having a height. And a second substrate 8 provided on the opposite side of the recess 3a of the ink supply member 3. The ink jet recording head 1 is formed on the second substrate 8, the second coating resin layer 9 whose height is equivalent to the first coating resin layer 7, and the first resin layer 7 and the second coating resin layer ( 9) further comprises a top plate 10 provided above and adapted to close the common flow duct 2.

In the ink jet recording head 1, the ink supply member 3, the end face of the first base material 4, the end face of the first coating resin layer 7, the end face of the second base material 8, the second coating resin layer ( The end face of 9) and the top plate 10 define a common flow duct 2. Each of the flow paths 5 formed by the first substrate 4 and the first coating resin layer 7 provides a liquid chamber in which each ink discharge energy generating device 4a is confined. In the ink jet recording head 1, ink i from the ink cartridge (not shown) is supplied to the common flow duct 2, and thus ink i supplied to the common flow duct 2 is separated from the individual flow path ( 5) Go through each.

The ink supply member 3 which forms part of the cavity flow duct 2 is formed of, for example, a resin that is resistant to ink, and includes a recess 3a that forms part of the cavity flow duct 2. do.

The first base material 4 is, for example, a silicon base material, and a plurality of electric heat converters are formed as the ink discharge energy generating device 4a at a surface surface set in advance in accordance with the semiconductor manufacturing process. The first base 4 is provided with a control circuit 4b for controlling the ink discharge energy generating device 4a. The end face of the first substrate 4 facing the cavity flow duct 2 forms part of the cavity flow duct 2. The surface of the first substrate 4 facing the ink discharge energy generating device 4a forms the lower surface of the individual flow path 5. The ink discharge energy generating device 4a is not limited to the electric heat converter, but may also be an electromechanical converter such as a piezo device.

The first coating resin layer 7 is patterned and formed on the first substrate 4, and supplies ink i from the cavity flow duct 2 near the ink discharge energy generating device 4a provided in the first substrate 4. Entails a separate flow path 5. The individual flow paths 5 are provided in connection with the ink discharge energy generating device 4a and are concave in the direction perpendicular to the depth direction of the cavity flow duct 2. At the distal end of the individual flow path 5 towards the cavity flow duct 2 is provided an ink supply orifice 11 for communicating with the cavity flow duct 2.

The nozzle 6 is set to communicate with the individual flow route 5 and to be heated and pressurized by the energy generated by the ink ejection energy supply device 4a to eject the ink i in the individual flow path 5. .

In particular, the first coating resin layer 7 is formed by patterning the oxetane resin composition on the surface of the first base material 4 with the ink discharge energy generating device 4a and curing the patterned oxetane resin composition. The oxetane resin composition contains, as essential components, an oxetane compound having at least one oxetanyl group in one molecule and a cationic photopolymerization initiator.

The oxetane resin composition for forming the first coating resin layer 7 will now be described. The oxetane compound in the oxetane resin composition has a four-membered ring which is an oxirane ring of an epoxy to which one carbon atom is added. Oxetane compounds show higher cation curing properties than epoxy compounds. The cured cationic polymer of the oxetane compound has a higher molecular weight than the cured epoxy polymer and can exhibit high tenacity, elongation, high reliability mechanical strength, higher water resistance and higher chemical resistance. The characteristics of the cured cationic polymer of the oxetane compound are very different from those of the hard and brittle cured epoxy polymer. On the other hand, the cured cationic polymer of the oxetane compound exhibits no mutation-inducing action attributable to the quaternary oxetanyl group, and is superior to the photo-curable epoxy resin with regard to safety.

There are two kinds of oxetane compounds, that is, a monofunctional oxetane compound having a single oxetanyl group in one molecule and a polyfunctional oxetane compound having two or more oxetanyl groups in a molecule. The monofunctional oxetane compound is represented by the following formula (1).

In formula (1), R ₁ represents a C1 to C6 alkyl group, a C1 to C6 fluoroalkyl group, an allyl group, an aryl group, a furyl group, or thienyl group such as a hydrogen atom, a methyl group, an ethyl group, a propyl group, or a butyl group. R ₂ is a C1 to C6 alkyl group such as methyl group, ethyl group, propyl group or butyl group, 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-bute C2 to C6 alkenyl, phenyl, benzyl, fluorobenzyl, methoxybenzyl or phenoxyethyl groups with aromatic rings, ethyl carbonyl and propyl carbonyl groups Or C2 to C6 alkyl carbonyl group such as butyl carbonyl group, ethoxy carbonyl group, propoxy carbonyl group, or C2 to C6 alkoxy carbonyl group such as butoxy carbonyl group, or ethyl carbamoyl group, propyl carbamoyl group, butyl carbamoyl group or pentyl carbamo C2 to C6 N-alkyl carbamoyl groups such as diary are shown.

The bifunctional oxetane compound having two oxetanyl groups is represented by the following formulas (2) and (3).

In formula (2), R ₁ has the same meaning as in formula (1).

In formula (3), R ₁ has the same meaning as in formula (1). R ₃ is a straight or branched saturated hydrocarbon of C 1 to C 12, a straight or branched unsaturated hydrocarbon of C 1 to C 12, an aromatic hydrocarbon, and a carbonyl group represented by Formulas F and G It is a divalent group selected from the group which consists of a linear or cyclic alkylene which has, and the aromatic hydrocarbon containing the carbonyl group represented by following formula (H) and (I).

<Formula A>

<Formula B>

<Formula C>

<Formula D>

<Formula E>

<Formula F>

<Formula G>

<Formula H>

<Formula I>

Other difunctional oxetane compounds are caldo type compounds and naphthalene type compounds.

In formulas A to E, R ₄ represents a hydrogen atom, a C1 to C12 alkyl group, an aryl group, or an aralkyl group, and R ₅ represents —O—, —S—, —CH ₂ —, —NH—, —SO ₂ — _{, -CH (CH 3) -,} -C (CH 3) 2 -, or -C (CF _{3) 2} - represents a, R ₆ represents a hydrogen atom or a C1 to C6 alkyl group.

In formula F, n represents an integer of 1 or more.

Tri- or higher-functional oxetane compounds include phenol-novolac oxetane compounds represented by the following formula (4), cresol-novolak oxetane compounds represented by the following formula (5), and triazines represented by the following formulas (6) and (7) And oxetane compounds having a backbone.

Other trifunctional or higher functional oxetane compounds include etherified compounds with hydroxyl group-containing silicone resins such as poly (hydroxylstyrene), calixarylene, silsesquioxane, and unsaturated monomers comprising oxetane rings And copolymers of alkyl (meth) acrylates.

In formulas 4 and 5, R ₁ is the same as in formula 1, and n is an integer of 1 or more. In the novolak oxetane compound, the number average number of the skeleton is preferably 3 to 10 when n is 1 to 8. If the number average of the number of skeletons exceeds 10, the viscosity value is higher and the density of crosslinking does not increase due to structural disturbances.

In formula (6), R ₁ has the same meaning as in formula (1).

In formula (7), R ₁ has the same meaning as in formula (1). R ₇ is a C1 to C12 branched alkylene group represented by the following formulas J, K, and L or an aromatic hydrocarbon represented by the formulas M, N, and P, wherein n is the number of functional groups linked to R ₇ as shown in formula (7) Indicates.

<Formula J>

<Formula K>

<Formula L>

<Formula M>

<Formula N>

<Formula P>

In formula (P), R ₈ represents a hydrogen atom, a C1 to C6 alkyl group or an aryl group.

These oxetane compounds are used alone or as a mixture. For the purpose of stronger chemical resistance or higher durability, it is preferred to use polyfunctional oxetane compounds. If the desired viscosity is not obtained by the use of a polyfunctional oxetane compound, they can be diluted with a monofunctional oxetane compound.

Oxetane compounds yield cured compounds that ultimately exhibit a high degree of cation cure. In the initial reaction step the cure rate can be increased with the addition of an appropriate amount of epoxy compound or vinyl ether compound. In this case, the addition amount is preferably 5 to 95% by weight based on the oxetane compound.

Since the first coating resin layer 7 is formed by a cured skeleton obtained when curing the oxetane resin composition, a cationic polymerization initiator is included in the oxetane resin composition in addition to the oxetane compound mentioned above. When activating energy rays such as ultraviolet rays are irradiated to the oxetane resin composition for patterning, a cationic photopolymerization initiator is used. These cationic photopolymerization initiators can be used alone or in combination.

Examples of commercially available cationic photopolymerization initiators include Opmeromers manufactured by CYRACURE UV1-6950 and UVI-6970, Asahi Denka Kogyo KK manufactured by Union Carbide Corporation. -SP-150, SP-151, SP-152, SP-170 and SP-171, CI-2855 manufactured by NIPPON SODA Co., LTD., Manufactured by Degussa Inc. Triaryl sulfonium salts, such as degacere KI85B, unsaturated or saturated aryl diazonium salts and diaryl iodonium salts. The sulfonic acid derivative may be PAI-101 manufactured by Midori Kagaku Co., Ltd.

The proportion of the cationic photopolymerization initiator is preferably 2 to 40 parts by weight based on 100 parts by weight of the oxetane compound. When the proportion of the cationic photopolymerization initiator is less than 2 parts by weight, the amount of acid generated by the irradiation of the activating energy ray is only small, which faces difficulties in patterning. Conversely, when the proportion of the cationic photopolymerization initiator exceeds 40 parts by weight, the cationic photopolymerization initiator itself tends to absorb light and lower the photosensitivity. In addition, when it is desired to improve the degree of curing, a combination of a cationic thermal polymerization initiator or a cationic photosensitive agent may be used.

The first coating resin layer 7 is formed of an oxetane resin composition containing an oxetane compound having at least one oxetanyl group in the molecule and a cationic photopolymerization initiator as essential components. Therefore, the first coating resin layer can exhibit high mechanical strength with high stiffness and elongation, so that it is possible to prevent inconvenience such as cracking or peeling of the resin layer from the first base material 4.

In addition to the above-mentioned oxetane resin composition consisting of an oxetane compound and a cationic photopolymerization initiator, various additives may be added to the first coating resin layer 7 if necessary. As such an additive, a coupling agent for further improving the intimate bond between the oxetane resin composition and the underlying first substrate 4 is preferred. As such a coupling agent, an aluminate-based, titanate-based, zirconate-based or silane-based coupling agent may optionally be used. Of these, the silane coupling agent is most preferred.

Examples of aluminate-based coupling agents include acetoalkoxy aluminum diisopropylate, aluminum diisopropoxy monoethyl acetoacetate, aluminum trisethyl acetoacetate and aluminum trisacetyl acetonate.

Examples of titanate-based coupling agents include isopropyl tristearoyl titanate, isopropyl tris (dioctylpyrophosphate) titanate, isopropyl tri (N-aminoethyl aminoethyl) titanate, tetraoctyl bis (ditridecyl Phosphate) Titanate, Tetra (2-2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphate titanate, bis (dioctyl pyrophosphate) oxyacetate titanate and bis (dioctyl pyrophosphate) ethylene Titanate is included.

Examples of zirconate-based coupling agents include zirconium tetrakisacetyl acetonate, zirconium dibutoxy bisacetyl acetonate, zirconium tetrakisethyl acetoacetate, zirconium tributoxy monoethyl acetoacetate and zirconium tributoxy acetylacetonate .

Examples of the silane coupling agent include vinyl trimethoxysilane, vinyl triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane, 3-glycidoxy propyl trimethoxysilane, 3-mer Captopropyl trimethoxysilane, 3-methacryloxy propyl trimethoxysilane, 3-glycidoxy propylmethyl dimethoxysilane, 3-chloropropyl trimethoxysilane and 3-isocyanate propyl triethoxysilane.

Among the silane coupling agents, the amino coupling agents are not preferred because they absorb the acid derived from the cationic photopolymerization initiator to lower the photosensitivity. The amount of the additive added is, for example, 0.1% by weight or more and less than 1% by weight based on the total weight of the material of the first coating resin layer 7 containing the oxetane resin composition. If the addition amount is less than 0.1% by weight, the desired effect on the hard bond is only low, whereas when the addition amount is 1% by weight or more, the development speed is significantly lowered, so that residual development tends to be produced or the resolution may be lowered.

By using an optimal coupling agent, ie, a silane coupling agent, for the first coating resin layer 7, the binding force of the boundary surface between the first base material 4 mainly composed of inorganic components and the oxetane resin composition composed of organic materials can be improved. Can be. Therefore, even if the first coating resin layer is exposed to the ink (i), the first coating resin layer can maintain a firm bonding state with respect to the first substrate 4, thereby improving the working reliability of the ink jet recording head 1. .

The oxetane resin composition used to form the first coating resin layer 7 may remain dissolved in a solvent. By using the oxetane resin composition dissolved in a solvent, optimum viscosity and coating properties can be obtained when coating the first coating resin layer 7 with the required film thickness on the first substrate 4.

It is sufficient that the solvent used can dissolve the oxetane compound or additive used. Examples of solvents that can be used are ketones such as methylethylketone or cyclohexanone, aromatic hydrocarbons such as toluene, xylene, or tetramethylbenzene, and cellosolves, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl Glycol ethers such as carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether or triethylene glycol monoethyl ether. Other examples of solvents used include acetates such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethylether acetate or dipropylene glycol monomethylether glycol, ethanol Alcohols such as propanol, ethylene glycol or propylene glycol, aliphatic hydrocarbons such as octane or decane, petroleum ethers, petroleum naphtha, petroleum solvents such as hydrogenated petroleum naphtha or solvent naphtha, and terpenes such as limonene. By use of these solvents, optimum solubility of the oxetane resin composition can be obtained. Aliphatic hydrocarbons and petroleum solvents in the solvent do not dissolve the ink flow duct pattern 12 of the soluble resin layer used to form the individual flow paths 5 of the ink jet recording head 1, as described later. It may be used as a solvent capable of dissolving the oxetane resin composition. Petroleum-based solvents have low solubility with respect to the soluble resin layer used to form the patterns of the individual flow paths 5, so that the collapse of the ink flow duct pattern 12 can only occur in extremely rare cases.

The first coating resin layer 7 composed of an oxetane compound containing at least one oxetanyl group in one molecule as an essential component and a cationic photopolymerization initiator may have a low stress. In addition, high stiffness and elongation as well as high reliability mechanical strength can be imparted to the first coating resin layer 7 so that peeling or cracking from the first substrate 4 may not occur. The ink jet recording head 1 provided with the first coating resin layer 7 can improve not only the quality but also the production yield so that high working reliability can be maintained for an extended time.

In addition, the first coating resin layer 7 formed by the cured oxetane resin composition having a lower stress than the cured epoxy resin is the first substrate more efficiently than when the first coating resin layer 7 is formed of the cured epoxy resin composition. Peeling from (4) can be prevented. In addition, the first coating resin layer 7 exhibits water resistance and chemical resistance by containing an oxetane compound.

Moreover, the recording head, together with the first coating resin layer 7 formed of the oxetane resin composition, can be lengthy or thick, so that the individual flow paths 5 or nozzles 6 of complicated or difficult structure are of high precision. It can be formed easily.

In addition to the oxetane resin composition, the first coating resin layer 7 containing the optimum additive, ie, the silane coupling agent, may be attached with respect to the first substrate 4 to improve the firmness, and thus the first substrate 4 Desorption from can be prevented more efficiently.

The second substrate 8 attached to the other side of the recess 3a of the ink supply member 3 is attached to the ink supply member 3 with an adhesive. This second substrate 8 is provided for setting the height of one side of the recess 3a to which the first substrate 4 is bonded so as to be equal to the height of the other side of the recess. The second substrate is therefore the same thickness as the first substrate (4). Similar to the first substrate 4, the second substrate 8 may be formed by a silicon substrate, but the material of the second substrate is not limited.

The second coating resin layer 9 formed on the second substrate 8 is for example formed by spin coating on the second substrate 8. The second coating resin layer is first to provide the height of the side of the recess 3a of the ink supply member 3 with the second coating resin layer, which is equal to the height of the side of the recess with the first resin layer 7. It is formed in the same thickness as the resin layer 7. Similar to the first coating resin layer 7, the second coating resin layer 9 may be formed of an oxetane resin composition, but there is no limitation on the kind of material. On the other hand, the recess 3a when adjusting the height of one side to the height of the other side of the recess 3a as long as the used member has the height of one side and the height of the opposite side of the recess 3a set equal. The member provided on the opposite side of) may be any suitable material type or structure, and may be different from the second substrate 8 or the second coating resin layer 9.

The top plate 10 is formed by a first coating resin layer which discharges ink i not only to form part of the cavity flow duct 2 but also to prevent opening of the cavity flow duct 2 towards the discharge surface 7a ( 7) and the second coating resin layer 9.

In the ink jet recording head described above, the first substrate 4 and the first coating resin layer 7 are provided on one side of the recess 3a of the ink supply member 3, while the second substrate 9 and the second substrate are provided. The coating resin layer 9 is provided on the opposite side of the recess 3a. The top plate 10 is mounted so as to rest on the first coating resin layer 7 and the second coating layer 9. In the ink jet recording head 1, the cavity flow duct 2 is provided with the ink supply member 3, the end face of the second coating resin layer 9, the end face of the second substrate 8, the second coating resin layer 9 The limit is defined by the distal face of and the top plate 10. The plurality of individual flow paths 5, which act as liquid chambers and confine the ink discharge energy generating device 4a, are limited by the first substrate 4 and the first coating resin layer 7. The individual flow paths communicate with the common flow duct 2. In this ink jet recording head 1, ink i from the ink cartridge is supplied to the common flow duct 2. The ink i thus supplied to the common flow duct 2 is then fed to the individual flow paths 5.

In the ink jet recording head 1, ink i flows from the ink cartridge to the cavity flow duct 2 and is fed to the individual flow path 5 via the cavity flow duct 2 and the ink supply orifice 11. . The ink i is then heated and pressurized by the ink discharge energy generating device 4a to be discharged through the nozzle 6 as liquid droplets.

More specifically, as shown in FIGS. 3A and 3B, a pulse current is supplied to the ink discharge energy generation device 4a of the ink jet recording head 1 in order to quickly heat the ink discharge energy generation device 4a. Then, as shown in FIG. 3A, the bubble (b) is generated in the portion of the ink (i) in contact with the ink discharge energy generating device 4a. In the ink jet recording head 1, as shown in Fig. 3B, the bubble b is expanded so that the bubble b presses the ink i. The ink i thus pressurized is discharged from the nozzle 6 as liquid droplets. After a part of the ink i is discharged as liquid droplets, the ink i flows from the ink cartridge to the common flow duct 2 of the ink jet recording head 1. The ink i is then fed through the ink supply orifices 11 and into the individual flow paths 5 to return to the state before ejection. The above operation sequence occurs repeatedly for the ejection of the ink i successively.

The manufacturing method of the ink jet recording head 1 is described.

As shown in FIG. 4, a silicon (Si) substrate is first provided as the first substrate (4). As the ink discharge pressure generating device 4a, a plurality of electric thermal transducers are formed on the surface of the first base material 4 by, for example, a semiconductor process.

On the surface of the first base material 4 along with the ink discharge energy generating device 4a, a positive resist is coated as a layer mainly composed of soluble resin, here a novolak resin, while adjusting the number of rotations of the spin coater. The resulting assembly is prebaked on a hotplate for 6 minutes at a temperature of 110 ° C. Using Canon Inc.'s mirror projection aligner light exposure device MPA-600FA, the individual flow paths 5 were patterned to expose the individual flow paths 5 as shown in FIG. In place of the path (5) forms an ink flow duct pattern (12) of the soluble resin layer. In this case, the light exposure amount is 800 mJ / cm ^2, for example.

The resist is then developed by, for example, an immersion developing method using a P-7G exclusive developer (TMAH (aluminum hydroxide 3% solution)), followed by washing with running pure water. The ink flow duct pattern 12 formed by the soluble resin is formed to produce the individual flow path 5 provided between the cavity flow duct 2 and the ink discharge energy generating device 4a. The film thickness after image development is about 10 micrometers as an example.

The above oxetane resin composition is dissolved in a concentration of about 50% by weight in petroleum naphtha, for example, which does not dissolve the ink flow duct pattern 12 formed of the positive resist, thereby preparing a solution that also contains other additives. . This solution is spin-coated to form a photosensitive first coating resin layer 7 over the ink flow duct pattern 12, as shown in FIG. The photosensitive first coating resin layer 7 containing the oxetane resin composition and optional additives is designed for example with a film thickness of 20 μm over the ink flow duct pattern 12.

Then, as shown in FIG. 7, patterned light exposure is performed with a mirror projection collimator light exposure apparatus (MPA-600FA from Canon) to form the nozzle 6 and the ink supply orifice 11. In carrying out such patterned light exposure, the activation energy ray 14 is first passed through the patterning mask 13 so that the part of the first coating resin layer which becomes the nozzle 6 and the ink supply orifice 11 is not exposed. It is irradiated on the coating resin layer 7. On the other hand, the light exposure amount is, for example, 800 mJ / cm ² , and the post baking is performed at about 65 ° C. for 60 minutes.

The portion of the first resin layer 7 not exposed to light is developed with petroleum naphtha, as shown in FIG. The resulting product is soaked in isopropyl alcohol (IPA) to remove development residues to remove the unexposed portions of the first coating resin layer 7 and form the nozzle 6 and ink supply orifice 11. The nozzles 6 each have a diameter of about 15 μm. The ink flow duct pattern 12 does not dissolve in petroleum naphtha and remains practically insoluble.

On the first substrate 4, a plurality of first coating resin layers 7 of the same or different shape are erected at one time. Thus, as shown in FIG. 9, the first substrate 4 is cut in this step using, for example, a dicer 15 manufactured by DISCO, Inc. under the trade name DAD-561. At this time, since the ink flow duct pattern 12 remains intact, any dust or dust generated during cutting the first substrate 4 can be prevented from entering the individual flow path 5.

The cleaved product is then placed in, for example, a chip tray, then immersed in propylene glycol monomethylether acetate solution, and simultaneously sonicated in the solution. This solution is used, for example, as a polar solution capable of dissolving a positive resist. This process dissolves the ink flow duct pattern 12 which has remained so far as shown in FIG.

The resulting product is heated for post-curing at 150 ° C. for about 1 hour to fully cure the photosensitive first coating resin layer 7.

As shown in Fig. 1, the first base material 4 on which the first coating resin layer 7 is placed is joined to one side of the recess 3a of the ink supply member 3, and the second coating resin layer 9 The second substrate 8 on which the top rests is joined to the other side of the recess 3a of the ink supply member 3. The upper plate 10 adapted to close the ejection surface 7a of the first coating resin layer 7 is composed of the ejection surface 7a of the first coating resin layer 7 to complete the ink jet recording head 1, and The second coating is bonded to the resin layer (9).

In the method of manufacturing the ink jet recording head 1 described above, the first coating resin layer 7 accompanying the individual flow path 5 and the nozzle 6 has as essential components one or more oxetanyl groups in one molecule. It is formed from the oxetane resin composition containing an oxetane compound and a cationic photoinitiator. As a result, the first coating resin layer 7 can be produced which shrinks to a lesser extent during curing and exhibits not only stiffness and elongation but also mechanical strength, so as to ensure high reliability. In conclusion, in the case of the ink jet recording head 1 of the present invention, there is no worry that the first coating resin layer 7 cracks or peels off from the first substrate 4. In addition, in the case of the ink jet recording head 1 of the present invention, it is possible to prevent the first coating resin layer 7 from being detached from the first substrate 4 even when a load is applied to the discharge surface 7a during cleaning. .

In addition, with the manufacturing method of the ink jet recording head 1 of the present invention, wherein the first coating resin layer 7 is formed of an oxetane resin composition, the first coating resin layer can be imparted with ink ( Even in contact with i) it is possible to prevent the layer from detaching.

Furthermore, in the method of manufacturing the ink jet recording head 1, the bonding between the first substrate 4 and the first coating resin layer 7 is achieved by using the first coating resin layer 7 made of the oxetane resin composition to which the additive is added. As a result, the robustness can be improved, and as a result, the ink jet recording head 1 which maintains the adhesion firmness between the first substrate 4 and the first coating resin layer 7 to ensure high working reliability for an extended time This can be obtained.

In the above, the present invention was applied to a printer. However, this is merely illustrative and the present invention can be applied to a wide variety of other liquid ejection devices such as fax machines or copiers.

<Example>

The following shows the results of the physical property investigation of the oxetane resin composition forming the first coating resin layer and the evaluation results of the ink resistance and printing performance of the ink jet recording head provided with the first coating resin layer thus formed.

<Investigation of physical properties of oxetane resin composition>

The following experiment was conducted to examine the inherent problem of the resin, that is, the post-cure internal stress of the resin. The internal stress was examined by observing the precured film thickness and the post cured film thickness of the resin layer. If the two film thicknesses are the same, it can be inferred that the internal stress generated by the volume change accompanying resin curing is extremely small.

<Example 1>

In Example 1, the oxetane resin composition containing solution, shown in Table 1 below, was spin coated onto a 6 inch wafer. The resulting product was prebaked on a hotplate at 90 ° C. for 5 minutes. The coating was then made to a film thickness of 20 μm and then exposed to 1 J / cm ² light using a mirror projection light exposure apparatus (MPA 600FA from Canon). After prebaking on a hotplate for 5 minutes at 90 ° C., the resulting product was cured at 200 ° C. for 1 hour to prepare a cured film of the oxetane resin composition.

Phenolic novolac oxetane compound (average number of basic structures: 3) 100 parts by weight Cationic photopolymerization initiator (SP-170 of Asahi Denka Kogyo K.K) 2 parts by weight Silane coupling agent (2- (3,4-epoxy cyclohexyl) ethyl trimethoxysilane) 0.5 parts by weight Organic solvents (petroleum naphtha: IPSOL 150 by Idemitsu Kosan Co., Ltd) 100 parts by weight

Comparative Example 1

In Comparative Example 1, the cured film of the alicyclic epoxy resin composition was obtained in the same manner as in Example 1 using the alicyclic epoxy resin composition containing solution shown in Table 2 below.

Alicyclic epoxy resin (EHPE-3150 of DICEL CHEMICAL INDUSTRIES, LTD.) 100 parts by weight Cationic photopolymerization initiator (SP-170 of Asahi Denka Kogyo K.K) 2 parts by weight Silane coupling agent (2- (3,4-epoxy cyclohexyl) ethyl trimethoxysilane) 0.5 parts by weight Organic Solvents (Xylene) 100 parts by weight

The thicknesses of the cured films obtained in Example 1 and Comparative Example 1 were measured after curing on a hotplate at 200 ° C. for one hour. The measurement results showed that the film thickness did not decrease for the cured films containing the oxetane resin compositions shown in Table 1, whereas the film thickness decreased for the cured films containing the alicyclic epoxy resin compositions shown in Table 2. It was shown.

Internal stresses developed in each cured film were then measured using a thin film stress measurement apparatus. It was found that the stresses in the cured films containing the oxetane resin compositions shown in Table 1 were noticeably reduced when compared to the cured films containing the alicyclic epoxy resin compositions shown in Table 2.

<Evaluation of Ink Resistance and Printing Performance of Ink Jet Recording Head>

<Example 2>

In Example 2, the ink jet recording head 1 shown in Fig. 1 was manufactured in the following manner. First, PMER-P of a novolak resin (Tokyo Oka Kogyo Co., Ltd) mainly used as the soluble resin layer is the first base material 4 with the ink discharge energy generating device 4a shown in FIG. -LA900PM). The positive resist was prebaked on a hotplate for 6 minutes at 110 ° C., and then patterned light exposure was performed using a projection light exposure apparatus (MPA 600 FA from Canon) to form the individual flow paths 5. In this way, the ink flow duct pattern 12 was formed by the soluble resin layer in the region that later became the individual flow path 5, as shown in FIG. At this time, the light exposure amount was 800 mJ / cm ² .

The resist was then developed, for example, by immersion development using dedicated developer P-7G (TMAH (aluminum hydroxide 3% solution)) and then washed with running pure water. After development, the film thickness of the positive resist was 10 μm.

The oxetane resin composition described above was then dissolved in, for example, about 50% by weight in petroleum naphtha, which did not dissolve the ink flow duct pattern 12. This solution was spin coated to form a photosensitive first coating resin layer 7 on the flow duct pattern 12 as shown in FIG. 6. The photosensitive first coating resin layer 7 containing the oxetane resin composition and optional additives was designed on the ink flow duct pattern 12 to a film thickness of, for example, 20 μm.

Thereafter, patterned light exposure was performed with Canon's mirror projection collimator light exposure apparatus MPA-600FA to form the nozzle 6 and ink supply orifice 11 as shown in FIG. When performing such patterned light exposure, the activation energy ray 14 is first passed through the patterning mask 13 so that the portion of the first coating resin layer which becomes the nozzle 6 and the ink supply orifice 11 is not exposed. Irradiated onto the coating resin layer 7. On the other hand, the light exposure amount was, for example, 800 mJ / cm ² , and the post baking was performed at 65 ° C. for about 60 minutes.

The portion of the first coating resin layer 7 not exposed to light was developed with petroleum naphtha shown in FIG. 8. The resulting product was immersed in IPA for washing to remove the developing residue, thereby removing the unexposed portions of the first coating resin layer 7 and forming a nozzle 6 and an ink supply orifice 11. . The nozzle 6 had a diameter of about 15 μm. The ink flow duct pattern 12 did not dissolve in petroleum naphtha and remained substantially insoluble.

At this stage the first substrate was cut using a Dicer manufactured by Disco, for example under the trade name DAD-561 as shown in FIG. 9. At this time, since the ink flow duct pattern 12 remains intact, any dust and dust generated when cutting the first substrate 4 can be prevented from being introduced into the individual flow paths 5.

The cleaved product is then placed, for example, in a chip tray, then immersed in propylene glycol monomethylether acetate solution, and ultrasonically applied to the solution. This solution was used, for example, as a polar solution capable of dissolving the positive resist. This process dissolved the ink flow duct pattern 12 which remained so far as shown in FIG.

The resulting product was heated for post curing at 150 ° C. for about 1 hour to fully cure the photosensitive first coating resin layer 7.

The first substrate 4, on which the first coating resin layer 7 shown in Fig. 1 lies, is joined to one side of the recess 3a of the ink supply member 3, and the second coating resin layer 9 is The second substrate 8 lying in the was joined to the other side of the recess 3a of the ink supply member 3. The upper plate 10 was bonded to the discharge surface 7a and the second coating resin layer 9 of the first coating resin layer 7 to complete the ink jet recording head 1.

Comparative Example 2

In Comparative Example 2, the ink jet recording head 1 was the same as in Example 2 except that the coating resin layer was formed with the epoxy resin composition containing solution shown in Table 2 and the coated resin layer was developed with xylene. Prepared in the manner.

The ink jet recording head 1 of Example 2 and Comparative Example 2 was soaked in black ink at 60 ° C. for one week in the manner of an ink immersion experiment. As black ink, an ink composed of pure water, ethylene glycol, and a black dye, LPR-5000 from Sony Corporation was used.

The result of the ink immersion experiment showed that for the ink jet recording head 1 of Example 2 in which the first coating resin layer 7 was formed of the oxetane resin composition shown in Table 1, the first coating resin layer 7 from the first substrate 4 ), No change was observed. In contrast, in the case of the ink jet recording head 1 of Comparative Example 2 in which the first coating resin layer 7 was formed of the alicyclic epoxy resin composition shown in Table 2, after the ink immersion, the first coating resin layer 7 was probably cured. Partial peeling was observed due to the stress caused by.

As an evaluation of printing performance, the ink jet recording heads 1 of Example 2 and Comparative Example 2 were mounted in a recording apparatus, and ink containing pure water, diethylene glycol, and black dye in a ratio of 80, 17.5, and 2.5 was used. The recording was performed using. In the case of the ink jet recording head 1 of Example 2, stable printing could be performed, and it was found that the obtained printed matter showed high quality. In contrast, in the case of the ink jet recording head 1 of Comparative Example 2, it was found that the print quality was not stabilized. In addition, in the case of the ink jet recording head 1 of Comparative Example 2, the state of the recording head after extended use showed interference fringes, which was observed by an optical microscope, by peeling of the coated resin layer. It was thought to have happened.

Various modifications, combinations, subcombinations, and changes may occur depending on design conditions and other factors, but those skilled in the art should understand that they are within the scope of the appended claims or their equivalents.

According to the present invention, it is possible to obtain a liquid discharge recording head which has improved production yield and quality, and exhibits high reliability during an extended period.

Claims (8)

Forming a liquid flow duct pattern from the soluble resin on a portion of the substrate that accompanies the liquid discharge energy generating device and later becomes the liquid flow duct, Forming a coating resin layer on the soluble resin having the liquid flow duct pattern formed thereon; Forming a liquid discharge opening in a portion of the coating resin layer overlying the liquid discharge energy generator, and Dissolving the soluble resin, The coating resin layer is formed of an oxetane resin composition containing an oxetane compound having at least one oxetanyl group in one molecule and a cationic photopolymerization initiator as essential components, In the coating resin layer forming step, a solution of the raw material component of the oxetane resin composition and the cationic photopolymerization initiator dissolved in a solvent which does not dissolve the soluble resin is used, and a cured product of the raw material component of the solution is produced, wherein The soluble resin is dissolved to exit the liquid discharge opening to form the liquid flow duct in communication with the liquid discharge opening, Method for manufacturing a liquid discharge recording head. A method for producing a liquid discharge recording head according to claim 1, wherein said oxetane compound contains one aromatic ring in one molecule. The method for producing a liquid discharge recording head according to claim 2, wherein the skeleton of the oxetane compound is a novolak type. A method for manufacturing a liquid discharge recording head according to claim 3, wherein the number of number average basic structures is 3 to 10. The method for manufacturing a liquid discharge recording head according to any one of claims 1 to 4, wherein the coating resin layer contains a coupling agent. A method for manufacturing a liquid discharge recording head according to claim 5, wherein said coupling agent is a silane coupling agent. 7. The method for producing a liquid discharge recording head according to claim 6, wherein the content of the silane coupling agent is 0.1% by weight or more and less than 1% by weight. The method for producing a liquid discharge recording head according to claim 1, wherein the solvent which does not dissolve the soluble resin is an aliphatic hydrocarbon or a petroleum solvent.

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