JP2006263950A - Inkjet recording head, and inkjet recording device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head which includes a crosslinking membrane of a liquid repellent polymeric resin composition which can be easily formed at a temperature of 120°C or lower on the surface of a discharging port of the inkjet recording head, is excellent in liquid repellent property and wear resistance, and for which the characteristics are maintained after the activity under a condition being exposed to a basic ink for a long period of time, and of which the printing quality is high, and to provide an inkjet recording device loaded with the inkjet recording head. <P>SOLUTION: This inkjet recording head has the discharging port which discharges a liquid for recording, and for which an ink repellent process is applied at least on the surrounding of the discharging port. The ink repellent processing section of the recording head is constituted by containing the crosslinking body of the polymeric resin composition containing a polymerization unit having a perfluoroalkyl group on the main chain and a side chain, and a polymerization unit having a cationic polymerization group, and also, containing a polymer which does not contain a Si atom in the particle, as an indispensable component for the inkjet recording head. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording head and an ink jet recording apparatus using the ink jet recording head, and in particular, the periphery of an ink discharge portion of the head is subjected to ink repellent treatment, excellent in water repellency and wear resistance, and excellent in print quality of an image obtained. Regarding the head.

  An ink jet recording apparatus that performs recording by discharging ink (recording liquid) from an ejection port of a recording head is known as an excellent recording apparatus in terms of quietness and high-speed recording. The print quality of the image obtained by the recording head greatly depends on the positional accuracy of the dots made up of ink droplets on the recording paper. The dot position accuracy depends on the flying direction of the ink droplets ejected from the ejection port of the recording head. In order to keep the flying direction constant, the peripheral edge of the discharge port during ink droplet discharge should be made uniform and stable. Specifically, the ink repellent (hereinafter referred to as the present specification) on the surface of the recording head including the peripheral edge of the discharge port. In writing, “water repellent” and “liquid repellent” also represent “ink repellent” unless otherwise specified). Here, the water repellent treatment agent is required to have both sufficient water repellency and stability to ink (the ink is often adjusted to basic for dissolution stability). Further, when foreign matter such as ink or paper adheres to the peripheral edge of the discharge port subjected to the water repellent treatment, a scraping operation is performed with a cleaning member such as a blade. That is, the water repellent agent is also required to have durability against friction such as rubbing operation.

  As a water-repellent treatment method, a technique (for example, see Patent Document 1) is disclosed in which a recording head discharge port peripheral portion is treated with fluoroalkylalkoxysilane or the like to make it water repellent.

  As another water repellent treatment method, a technique for obtaining high water repellency even after a cleaning operation by using a fluorine compound having a reactive group and an epoxy resin in combination to fix the fluorine compound in the polymerized cured film (for example, , See Patent Document 2).

  Furthermore, the technique (for example, refer patent document 3) of processing with the processing agent containing fluorine-containing resin and blocked isocyanate is disclosed.

Furthermore, a technique for forming a cured film of a polymer having a perfluoroalkyl group and an epoxy group in the molecule to achieve both water repellency and adhesion (for example, see Patent Document 4) is disclosed.
JP 56-895669 A JP-A-7-148930 Japanese Patent No. 3382416 JP 2000-26575 A

  However, in the technique of Patent Document 1, in order to complete the water-repellent treatment, the material forming the discharge port is destroyed by heating at a high temperature of 150 ° C. or more for a long time or in a high pH solution. Processing that may cause fear is necessary, and yet the durability against friction such as wiping operation is insufficient.

Further, in the technique of Patent Document 2, since the fluorine compound is hardly dissolved in the epoxy resin, uniform treatment is often difficult. When the fluoroalkyl chain length of the fluorine compound is shortened to increase the solubility, the fluorocarbon on the surface is reduced. Transferability of alkyl chain is deteriorated and water repellency is decreased, and the amount of fluorine compound present in the crosslinked film is increased. Therefore, the crosslinking density of the film is decreased, the strength of the film is decreased, and the durability is deteriorated. Or

  Furthermore, in the technique of Patent Document 3, although high scratch resistance is reported, since the reactivity of the blocked isocyanate is poor, a heat treatment for a long time at a high temperature (160 ° C.) is necessary. However, it is difficult to increase the crosslinking density, and it is difficult to reproducibly produce a film with excellent performance.

  Furthermore, in the technique of Patent Document 3, a relatively high water repellency is reported, but the polymer shown here is a polyether resin having a perfluoroalkyl group introduced in the side chain, and the main chain not containing fluorine. And the component of the linking group occupies a relatively high proportion, and as a result, sufficient liquid repellency cannot be exhibited.

  In short, the currently proposed technology has not yet proposed an ink jet recording head that has both friction resistance and water repellency (ink repellency) as required. There is a demand for the development of an ink jet recording head having excellent print quality and excellent long-term friction resistance.

An object of the present invention is to solve the conventional problems and achieve the following objects.
That is, the present invention includes a crosslinked film of a liquid repellent polymerizable resin composition that can be easily formed at a temperature of 120 ° C. or less on the discharge port surface, and has excellent liquid repellency and wear resistance. It is an object of the present invention to provide an ink jet recording head with high print quality that has characteristics that can be maintained even after long-term use under conditions exposed to basic ink, and an ink jet recording apparatus equipped with such an ink jet recording head.

  As a result of intensive studies to solve the above problems, the present inventor obtained by curing a polymer having a perfluoroalkyl group in the main chain as well as a side chain and further having a cationic polymerizable group by cationic polymerization. The present inventors have found that the above object can be achieved by the coating film to be completed, and have completed the present invention.

That is, this invention achieves the said objective by the following content.
(1) In an ink jet recording head having an ejection port for ejecting a recording liquid and at least a portion around the ejection port being subjected to ink repellent treatment, the ink repellent treatment portion of the recording head has perfluoro in the main chain and side chain. It comprises a crosslinked product of a polymerizable resin composition, containing a polymer unit having an alkyl group and a polymer unit having a cationic polymerizable group, and a polymer containing no Si atom in the molecule as an essential component. An ink jet recording head.

(2) The ink jet recording head according to (1), wherein the polymer contains a polymer unit represented by the following general formula (1) as a polymer unit having a perfluoroalkyl group in the main chain and side chain.
General formula (1):

In the formula, R _f ¹¹ represents a fluorine atom, a C 1-8 perfluoroalkyl group or —OR _f ¹² group, and the R _f ¹² group represents a C 1-20 perfluoroalkyl group.

(3) The ink jet recording head according to (1) or (2), wherein the polymer contains a polymer unit represented by the following general formula (2) as a polymer unit having a perfluoroalkyl group in the side chain.
General formula (2):

In the formula, R _f ²¹ represents a C 1-20 perfluoroalkyl group, L ²¹ represents a C 1-20 linking group, and m is 0 or 1.

(4) The ink jet recording head according to any one of (1) to (3), wherein the polymer contains a polymer unit represented by the following general formula 3 as a polymer unit having a cationic polymerizable group.
General formula (3):

In the formula, L ³¹ represents a linking group having 1 to 20 carbon atoms, X ³¹ represents an organic group containing a cationic polymerizable group, and n is 0 or 1.

(5) The polymerizable resin composition further contains at least one of a curing agent and a curing accelerator, and a crosslinked body is formed by coating and curing the cured film forming composition. The ink jet recording head according to any one of (1) to (4) above.

(6) An ink jet recording apparatus including the ink jet recording head, wherein the ink jet recording head is the ink jet recording head according to any one of (1) to (5).

The ink jet recording head of the present invention is excellent in water repellency and abrasion resistance, and has high print quality. When the fluorine-containing polymer used in particular is a fluorine-containing polymer suitable for the present invention, wear resistance and liquid repellency are maintained for a long time.
In addition, the polymerizable resin composition for forming a water-repellent resin film in the present invention can easily form a crosslinked resin film at a temperature of 120 ° C. or less on the discharge port surface of an ink jet recording head.

<Inkjet recording head>
The ink jet recording head of the present invention will be described below.

(Polymerizable resin composition)
First, a polymerizable resin composition used in the inkjet recording head of the present invention, and a polymer unit having a perfluoroalkyl group in the main chain and side chain, which is contained as an essential component in the polymerizable resin composition, and cationic polymerization A polymer containing polymerized units having a functional group and containing no Si atom in the molecule (hereinafter also referred to as a fluorine-containing polymerizable polymer) will be described.
In the present specification, unless otherwise specified, () [] in the chemical formula represents a repeating unit, and the subscript of () [] represents a molar composition ratio.

[Fluorine-containing polymerizable polymer]
(Polymerized unit having a perfluoroalkyl group)
As described above, the fluorine-containing polymerizable polymer used in the ink jet recording head of the present invention is a polymer containing a polymer unit having a perfluoroalkyl group in the main chain and side chain and a polymer unit having a cationic polymerizable group. . Fluorine is an essential component for ink repellent properties, and the cationic polymerizable group is a polymerizable group-containing component that is added within the molecule of the fluorine-containing polymerizable polymer, between the fluorine-containing polymerizable polymer molecules, or as necessary. It is an essential component for increasing the strength of the water-repellent resin film by forming a crosslinked structure by a covalent bond and maintaining the adhesion with the surface of the constituent material of the head before processing, which is the lower layer.

  Here, the structure having a perfluoroalkyl group in the main chain means a structure in which all the hydrogen atoms bonded to one carbon atom forming the main chain of the polymer are substituted with fluorine, and the side chain The structure having a perfluoroalkyl group is a structure in which a perfluoroalkyl group is bonded to a carbon atom forming the main chain of the polymer directly or via an appropriate linking group.

(Polymerized units having perfluoroalkyl groups in the main chain and side chain)
In order to improve liquid repellency, it is important to contain a perfluoroalkyl group not only in the side chain but also in the main chain, and in order to achieve both strength and liquid repellency, it is efficient (ie, incidental). It is important to introduce a perfluoroalkyl group (with as little as possible no portion containing fluorine). From such a viewpoint, a polymer unit represented by the following general formula (1) can be preferably used.
General formula (1):

In the formula, R _f ¹¹ represents a fluorine atom, a C 1-8 perfluoroalkyl group or —OR _f ¹² group, and the R _f ¹² group represents a C 1-20 perfluoroalkyl group. Among these, preferred as R _f ^11, a fluorine atom, -CF _3, -CF ₂ CF _3, a -OCF ₂ CF ₂ CF _3, availability, handleability made, in view of the polymerizable, -CF ₃ and -OCF ₂ CF ₂ CF ₃ it is particularly preferred.

The polymerization unit represented by the general formula (1) may be used alone or in combination of two or more.
Specific examples of the polymerization unit represented by the general formula (1) are shown below.

(Polymerized unit having a perfluoroalkyl group in the side chain)
In the fluorine-containing polymerizable polymer used in the present invention, a polymer unit having a perfluoroalkyl group in the side chain is introduced for the purpose of further improving the liquid repellency. A preferred form of such a polymerized unit is a structure represented by the following general formula (2).
General formula (2):

Wherein, R _f ²¹ represents a perfluoroalkyl group having 1 to 20 carbon atoms, preferably a linear perfluoroalkyl group having 4 to 20 carbon atoms, particularly preferably straight-chain perfluoroalkyl group having 6 to 20 carbon atoms is there. L ²¹ represents a linking group having 1 to 20 carbon atoms. Preferable examples of L ²¹ include structures represented by the following general formula (2a) and general formula (2b).
General formula (2a):

L ³² represents a linking group having 1 to 20 carbon atoms, preferably a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, which may include a linear structure or a branched structure, It may contain a ring structure and may have a heteroatom selected from O, N and S.

  General formula (2b):

L ³³ represents the same contents as L ³² . m is 0 or 1.

The polymerization unit represented by the general formula (2) may be used as a single type, or two or more types may be used in combination.
Specific examples of the polymer unit represented by the general formula (2) are illustrated below.

  The fluorine content in the fluorine-containing polymerizable polymer used in the present invention is preferably 20 to 70% by mass, more preferably 30 to 65% by mass, and particularly preferably 35 to 60% by mass. It is. By setting the fluorine content within the above range, sufficient water repellency and crosslinkability can be achieved.

(Polymerized unit having a cationic polymerizable group)
The cationic polymerizable group is a reactive group that causes a polymerization reaction and / or a crosslinking reaction when irradiated with an active energy ray in the presence of an active energy ray-sensitive cationic polymerization initiator. As a preferable form of the polymerization unit containing a cationic polymerizable group, a polymerization unit represented by the following general formula (3) can be mentioned.
General formula (3):

In the formula, a preferred form of L ^{31 is the same as} the preferred form of L ²¹ . X ³¹ represents an organic group containing a cationically polymerizable group, and may be monovalent or divalent, and examples of the cationically polymerizable group include an epoxy group, an oxetanyl group, a cyclic acetal group, a cyclic lactone group, A cyclic thioether group, a spiro orthoester group, a vinyl group (such as vinyl ethers and styrene derivatives) and the like can be mentioned. Of these, a cyclic ether is preferable, and an epoxy group and an oxetanyl group are particularly preferable because of high polymerization reactivity. n is 0 or 1.

  Specific examples of the polymerization unit represented by the general formula (3) are illustrated below.

  In order to develop sufficient film strength, it is necessary to increase the composition ratio of the polymerized units containing a cationically polymerizable group. Although it differs depending on the type of polymerized unit having a perfluoroalkyl group, it is generally preferred that the polymerized unit containing a cationically polymerizable group occupies 10 to 70 mol% in the fluorine-containing polymerizable polymer, and 10 to 60 mol%. More preferably, it occupies 20-50 mol%.

(Other polymer units)
In addition to these polymerized units, the fluorine-containing polymerizable polymer may have other polymerized units as appropriate from various viewpoints such as adhesion to a substrate, polymer Tg (contributing to film hardness), dustproof / antifouling properties, etc. It may also contain polymerized units constituting other segments and polymerized units that serve as connecting sites of segments).

  The monomer constituting the other polymerization unit is not particularly limited as long as it can be copolymerized with the polymerization unit containing the perfluoroalkyl group and the monomer constituting the polymerization unit containing the cationic polymerizable group. Any of them may be used, and may contain any functional group, but preferably does not have a hydrophilic functional group (for example, a hydroxyl group, a carboxyl group, etc.) from the viewpoint of not hindering water repellency. When these hydrophilic functional groups are used in such a form as to react with a curing reactive additive, it can be preferably used.

  For the purpose of imparting further water repellency, introduction of a component containing a Si atom in the molecule, such as polydimethylsiloxane, may be considered as the other polymer unit. However, in many cases, the components of the ink used in the ink jet are basic, which leads to insufficient resistance to the ink. Therefore, in the present invention, the fluorine-containing polymerizable polymer is a polymer containing no Si atom in the molecule.

Among the examples of monomers constituting the above other polymerization units, those having no functional group include olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, ethyl acrylate) , 2-ethylhexyl acrylate, acrylate having polydimethylsiloxane at the ester site), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, allyl methacrylate, etc.), styrene derivatives (styrene, p-methoxystyrene, etc.), Vinyl ethers (methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N, N-dimethylacrylamide, Nt Butyl acrylamide, N-cyclohexyl acrylamide, etc.), methacrylamides (N, N-dimethylmethacrylamide), acrylonitrile, etc., and olefins, acrylic esters (ester groups having 4 or more carbon atoms acrylate, poly Particularly preferred are acrylates having dimethylsiloxane at the ester site), methacrylic acid esters (methacrylates having an ester group of 4 or more carbon atoms, methacrylates having polydimethylsiloxane at the ester site), styrene derivatives, and vinyl ethers.

  Hydroxyl group-containing vinyl monomers (2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl acrylate, N-hydroxyacrylamide, p-hydroxymethylstyrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, etc.), silane cups, etc., containing functional groups Ring group-containing vinyl monomers (3-trimethoxysilylpropyl acrylate, 3-triethoxysilylpropyl methacrylate, etc.), amino group-containing vinyl monomers (3-dimethylaminopropyl acrylate, 3-aminopropylacrylamide, etc.), carboxyl group-containing vinyl monomers (Acrylic acid, crotonic acid, maleic acid, itaconic acid, etc.).

  A plurality of monomers constituting the other polymerization units may be combined depending on the purpose. When other polymerized units are used, the total of other polymerized units is preferably introduced in a range of 65 mol% or less in the fluorine-containing polymerizable polymer, and is in a range of 40 mol% or less. Is more preferable, and the range of 30 mol% or less is particularly preferable.

  The number average molecular weight of the above-mentioned fluorine-containing polymerizable polymer of the present invention and the fluorine-containing polymerizable polymer containing other polymerization units used as necessary is preferably 1500 to 500,000, and the degree of polymerization is It is preferably 10 to 1,000. More preferably, the average molecular weight is 1500 to 200,000 and the degree of polymerization is 10 to 500. In particular, the average molecular weight is preferably 1500 to 100,000, and the degree of polymerization is preferably 10 to 200.

  Specific examples of the fluorine-containing polymerizable polymer of the present invention are shown below. The number attached to each polymer unit represents the mole fraction.

  The fluorine-containing polymerizable polymer used in the present invention can be synthesized by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

The polymerization initiation method includes a method using a radical initiator, a method of irradiating light or radiation, and the like. These polymerization methods and polymerization initiation methods are, for example, the revised version of Tsuruta Junji “Polymer Synthesis Method” (published by Nikkan Kogyo Shimbun, 1971), Takatsu Otsu, Masato Kinoshita, “Experimental Methods for Polymer Synthesis” It is described on pages 124-154, published in 1972.

Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable.
Solvents used in the solution polymerization method are, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, It may be a single organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, or a mixture of two or more, or a mixed solvent with water.

  The polymerization temperature needs to be set in relation to the molecular weight of the polymer to be produced, the type of initiator, etc., and can be from 0 ° C. or lower to 100 ° C. or higher, but the polymerization can be performed in the range of 50 to 100 ° C. preferable.

The reaction pressure can be selected as appropriate, but usually it is preferably 1 to 100 kg / cm ² , particularly about 1 to 30 kg / cm ² . The reaction time is about 5 to 30 hours. The obtained polymer may be subjected to purification such as reprecipitation.

[Polymerizable resin composition]
Next, the polymerizable resin composition will be described.
The polymerizable resin composition used in the inkjet recording head of the present invention is a resin composition containing at least one fluorine-containing polymerizable polymer described above, and the fluorine-containing polymerizable resin containing fluorine and a cationic polymerizable group. It is a composition containing a polymer and a solvent for dissolving or emulsifying and dispersing the polymer, and further contains other components appropriately selected as necessary.

(solvent)
The solvent contained in the polymerizable resin composition is not particularly limited as long as the fluorine-containing polymerizable polymer is uniformly dissolved or dispersed without causing precipitation, and <two or more kinds of solvents may be used in combination. it can.

  As the solvent used in the present invention, it is preferable to use a highly safe solvent. A solvent having high safety is a solvent having a high management concentration (an index indicated by a work environment evaluation standard), preferably having a management concentration of 100 ppm or more, and more preferably 200 ppm or more. Furthermore, in order to form a film on the polymerizable resin composition in an appropriate time, those that volatilize by heating from room temperature to 150 ° C. are preferable. Preferred examples include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), ethers (tetrahydrofuran, 1,4-dioxane, etc.), alcohols (methanol, ethanol, isopropyl). Alcohol, 2-butanol, ethylene glycol, etc.), aromatic hydrocarbons (toluene, xylene, etc.), water and the like.

(Other ingredients)
The polymerizable resin composition for forming a resin film of the present invention usually takes the form of a liquid, the fluorine-containing polymerizable polymer as an essential component, and if necessary, various additives and a polymerization initiator, It is prepared by dissolving in an appropriate solvent. At this time, the concentration of the solid content is appropriately selected depending on the application, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1 to 20% by mass. %.

Hereinafter, other components used will be described.
1) Polymerization initiator A curing system comprising a cationically polymerizable reactive group uses an acid or a photoacid generating compound as a curing accelerator. That is, a known compound such as a photo-initiator for cationic photopolymerization, a photo-decoloring agent for pigments, a photo-discoloring agent, a known acid generator used in a microresist, and the like, and a mixture thereof can be used. Examples of the acid generator include organic halogenated compounds and disulfone compounds.

  In the present invention, particularly preferably used acid generators include onium salts. Among them, diazonium salts, iodonium salts, sulfonium salts, iminium salts are used for photopolymerization initiation photosensitivity, compound material stability, etc. It is preferable from the point.

  Specific examples of onium salts that can be suitably used in the present invention include, for example, an amylated sulfonium salt described in paragraph [0035] of JP-A-9-268205, and JP-A-2000-71366. A diaryl iodonium salt or a triarylsulfonium salt described in paragraphs [0010] to [0011], a sulfonium salt of thiobenzoic acid S-phenyl ester described in paragraph [0017] of JP-A-2001-288205, Examples thereof include the onium salts described in paragraph numbers [0030] to [0033] of JP-A-2001-133696.

  Other examples of the acid generator include organic metal / organic halides described in paragraphs [0059] to [0062] of JP-A-2002-29162, and a photoacid generator having an o-nitrobenzyl type protecting group. And compounds such as compounds that generate photosulfonic acid to generate sulfonic acid (iminosulfonate, etc.).

2) Additives Reactive groups (epoxy groups, oxetane groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiro orthoester groups, vinyl ether groups, isocyanate groups, etc.) from the standpoint of interfacial adhesion to the substrate, etc. A compound having two or more, a polyfunctional (meth) acrylate compound, a reactive silane coupling agent, a curing agent such as aminoplast, polybasic acid or anhydride thereof, or inorganic fine particles such as silica, conductive fine particles {ITO, ATO, Sb ₂ O ₃ , SbO ₂ , In ₂ O ₃ , SnO ₂ , conductive ZnO, AZO (AL doped zinc oxide), conductive metal oxide fine particles such as antimony zinc pentoxide, titanium nitride, zirconium nitride , Conductive nitrides such as hafnium nitride, metal particles such as gold, silver, and copper} can also be added. When these are added, it is preferably in the range of 30% by mass or less, more preferably in the range of 20% by mass or less, based on the total solid content in the polymerizable resin composition for forming a resin film. A range of 10% by mass or less is particularly preferable.

  When using a compound containing a reactive group other than a cationic polymerizable group as an additive or when the fluorine-containing polymerizable polymer contains a reactive group other than cationic polymerizable, not only the cationic polymerization initiator, It is preferable to use a radical polymerization initiator and a crosslinking reaction accelerator in combination.

  In addition, for the purpose of further enhancing properties such as antifouling properties and water resistance, known silicone-based or fluorine-based antifouling agents, slipping agents, and the like can be appropriately added. When these additives are added, it is preferably added in a range of 20% by mass or less, more preferably in a range of 10% by mass or less, based on the total solid content of the polymerizable resin composition for resin film formation. Particularly preferably 5% by mass or less.

[Formation of ink repellent treatment part]
The ink jet recording head of the present invention is an ink jet recording head having an ejection port for ejecting a recording liquid, and has an ink repellent treatment portion of the recording head formed by ink repellent treatment at least around the ejection port. The ink-repellent treatment part comprises a crosslinked product of a polymerizable resin composition containing at least one fluorine-containing polymerizable polymer as an essential component, and the fluorine-containing polymerizable polymer has a main chain and a side chain. The polymer is characterized in that the polymer has a polymer unit having a perfluoroalkyl group and a polymer unit having a cationic polymerizable group, and does not contain a Si atom in the molecule. That is, the ink repellent treatment part includes a crosslinked product obtained by crosslinking the polymerizable resin composition. Here, the crosslinked product obtained by crosslinking the polymerizable resin composition is a resin film formed by applying the polymerizable resin composition and then drying and evaporating the solvent. In addition, it means a crosslinked product obtained by forming a crosslinked structure by polymerizing a polymerizable polymer in the polymerizable resin composition.

  The ink-repellent treatment part is preferably constructed by applying a coating solution of the polymerizable resin composition directly or through another layer to a substrate described later. The coating solution is prepared by mixing and diluting a matrix binder solution containing a cationically polymerizable fluorine-containing polymer and, if necessary, a coating dispersion medium to a predetermined concentration.

  In order to form a resin film using the above-mentioned polymerizable resin composition, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, a micro gravure on the surface of a nozzle plate A film of a polymerizable resin composition for forming a resin film is formed by a known thin film forming method such as a coating method or an extrusion coating method, and a crosslinking reaction is performed by active energy rays or heat.

As the active energy ray, α ray, γ ray, X ray, ultraviolet ray, visible ray, electron beam and the like can be used. Of these, ultraviolet rays and visible rays are preferably used from the viewpoint of cost and safety, and ultraviolet rays are more preferably used.
As a light source for irradiating ultraviolet rays or visible light, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, a xenon lamp, a chemical lamp, or the like can be used.

  Usually, since the cationic polymerization reaction is inhibited by moisture, it is preferable to carry out the curing reaction under conditions where the humidity of the reaction atmosphere is lowered. In addition, heating in the latter half of the curing process is preferable from the viewpoint of sufficiently promoting the curing reaction. In this case, a temperature range of about 30 to 150 ° C is preferable, more preferably 30 to 120 ° C, and still more preferably 50 to 120 ° C. The heating time is preferably in the range of 30 seconds to 100 hours, more preferably 1 minute to 10 hours, and particularly preferably 1 minute to 3 hours.

The coating solution is preferably filtered before coating. As a filter for filtration, it is preferable to use a filter having a pore diameter as small as possible within a range in which components in the coating solution are not removed. For the filtration, a filter having an absolute filtration accuracy of 0.1 to 100 μm is used, and a filter having an absolute filtration accuracy of 0.1 to 25 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, it is preferable to perform filtration at a filtration pressure of 15 kgf / cm ² or less, more preferably 10 kgf / cm ² or less, and further 2 kgf / cm ² or less.

  The filtration filter member is not particularly limited as long as it does not affect the coating solution. It is also preferable to ultrasonically disperse the filtered coating solution immediately before coating to assist defoaming and dispersion holding of the dispersion.

  The thickness of the ink-ink-treated portion (resin film) of the present invention is not particularly limited, but is preferably 0.01 to 100 μm, more preferably 0.1 to 10 μm, and particularly preferably 0.5 to 5 μm.

[Ink-repellent treatment part of inkjet recording head]
The ink jet recording head of the present invention may be any liquid discharge head that ejects a conventionally known minute droplet. For example, Pondo Stephen F.M. "Inkjet Technology and Product Development Strategies", (Torrey Pines, 2000), "Inkjet printer technology and materials" supervised by Takeshi Amari (CMC, 1998), "Inkjet recording and printer recording system and printhead development" ”{Heads of various recording methods described in {CMC Co., Ltd., 2000]}.

  Specifically, continuous methods such as charge control type and pressure vibration type, electro-mechanical conversion method (piezo type, etc.), electro-thermal conversion method (bubble jet type), electrostatic suction method, ultrasonic method, etc. On-demand method.

  The peripheral portion where the ink repellent treatment portion is formed is preferably at least the peripheral edge of the ink droplet discharge port of the various recording heads as described above. For example, an ink jet recording head having an ejection port for ejecting ink and an ink path communicating with the ejection port, a recording head unit having an ink supply member for supplying ink to the ink path, and the ink supply member In the ink jet recording head including an ink tank portion for storing ink supplied to the ink path, for example, the peripheral portion of the nozzle hole tip of the discharge portion (nozzle) forming member is used as the ink repellent treatment portion. Is preferred. However, the present invention is not limited to this by the recording method, the head structure, and the like.

[Method of forming ink repellent portion]
The ink repellent treatment may be performed at any time before and after the nozzle is drilled in the nozzle plate. The nozzle diameter perforated in the nozzle plate is such that the size of the ink droplet ejection port is preferably 15 to 100 μm, more preferably 20 to 60 μm. Examples of methods for drilling these nozzles include press working, electroforming, excimer laser processing, and photofabrication methods.

  In addition, when ink repellent treatment is performed after nozzle perforation, a method in which the inside of the nozzle hole is closed with a resist and the resist is removed after the treatment, a method in which a gas flow is passed through the nozzle, and the like are preferably performed. A masking method is also preferable as a method for precisely controlling the position and amount of the polymerizable resin composition for ink repellent treatment entering from the ink droplet discharge port into the nozzle hole. Further, when the nozzle plate is bonded to the head portion after the ink repellent treatment, it is preferable that the back surface of the plate is not subjected to the ink repellent treatment.

  A conventionally known substrate is used for the nozzle plate used in the present invention. For example, it is made of metal, ceramics, silicone, glass, plastic or the like. For example, simple metals such as titanium, chromium, iron, cobalt, nickel, copper, zinc, tin, gold, nickel-phosphorus alloy, tin-copper-phosphorus alloy (phosphor bronze), copper-zinc alloy, stainless steel 40, etc. Alloys and thermosetting, solvent-resistant, chemical-resistant, heat-resistant organic resin materials {for example, thermosetting polyimide, polyethersulfone, polyphenylene, polycarbonate, polysulfone, ABS resin (acrylonitrile / butadiene / styrene copolymer) ), Polyethylene terephthalate, polyethylene naphthalate, polyacetal, sulfide, etc.} materials formed of various photosensitive resins.

Further, these materials can be used by being laminated on a laminate. For example, the rigidity of the entire nozzle plate can be increased by bonding an organic resin material and a highly rigid inorganic material such as metal or ceramics. That is, the Young's modulus of the organic resin material is about 100 to 300 / mm ^2, since much less when compared metal 8000~15000kg / mm ^2, the 10000~20000kg / mm ² ceramics, the ink jet is only an organic resin material The ink drop velocity Vj may decrease due to deformation following the driving pressure of the ink, and the ink drop velocity Vj may decrease. However, a high-rigidity material is bonded to the resin material with a thin film adhesive (adhesive layer). Thus, the overall rigidity can be improved.

  The thickness of the plate is preferably about 30 to 50 μm in view of processing strength, energy load required for processing, lightness as a head, and the like.

  The surface of the substrate on which the resin film of the ink repellent treatment part of the present invention is formed preferably has irregularities. As a result, the adhesion with the resin film is maintained by the anchor effect with the resin film of the ink repellent portion, and the strength of the resin film is improved.

As for the surface shape of the surface of the substrate on which the resin film of the ink repellent treatment part is formed, the arithmetic average roughness (Ra) of surface irregularities based on JIS B-0601-1994 is 0.5 μm or less, and the ten-point average roughness (Rz). ) (Ra / Rz) is 0.1 or more, the maximum height (Ry) is 0.5 μm or less, and the average surface roughness (Sm) is preferably in the range of 0.005 to 1 μm. More preferably, Ra is 0.01 to 0.3 μm or less, the ratio (Ra / Rz) to the ten-point average roughness (Rz) is 0.15 or more, the maximum height (Ry) is 0.3 μm or less, and the surface An uneven | corrugated average space | interval (Sm) is 0.001-0.5 micrometer.
Within this range, it is preferable because the uniform coatability and adhesiveness of the resin film of the ink repellent treatment part can be maintained well.

  Further, instead of directly forming the resin film of the ink repellent treatment portion on the substrate, also when the intermediate layer described later is used, after the surface of the intermediate layer on which the resin film of the ink repellent treatment portion is formed is provided with an uneven shape. It is preferable to coat the polymerizable resin composition in the present invention. A preferable surface uneven state is the same range as described above.

[Middle layer]
The ink repellent treatment portion may be provided with at least one intermediate layer between the nozzle plate (substrate) and the resin film formed by the ink repellent treatment. The intermediate layer preferably has functions such as adhesion, hard coat properties, primer properties, and conductivity.

  The intermediate layer preferably has adhesion to the substrate and the resin film, and may be any of an inorganic layer, an organic layer, and an inorganic-organic hybrid layer. From the viewpoint of adhesion, the substrate and the ink repellent treatment It is appropriately selected depending on the combination of parts. The intermediate layer preferably has a hard coat property (a layer having a pencil hardness of 2 or more, preferably 3 or more). Furthermore, it is preferable that conductivity is imparted.

  When the intermediate layer is composed of an organic layer or an inorganic-organic hybrid layer, the intermediate layer is preferably formed by a crosslinking reaction or a polymerization reaction of a curable compound by light and / or heat. For example, a coating composition containing a polyfunctional monomer such as polyester (meth) acrylate, polyurethane (meth) acrylate, a polyfunctional oligomer, or a hydrolyzable functional group-containing organometallic compound is coated on a transparent support, It can be formed by crosslinking reaction or polymerization reaction.

  The curable functional group is preferably a photopolymerizable functional group, and the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound. Furthermore, the hard coat property is improved by appropriately using fine particles of the polymerizable resin composition in the ink repellent portion. Furthermore, electroconductivity can be provided by containing the said electroconductive fine particles.

When the intermediate layer is a layer immediately below the ink repellent portion of the present invention, it is preferable that the surface of the layer has irregularities. As a result, the adhesion with the resin film is maintained by the anchor effect with the resin film of the ink repellent portion, and the strength of the resin film is improved.
A preferable surface shape of the intermediate layer is in the same range as the surface shape value of the surface of the substrate on which the resin film of the ink repellent portion is formed.

[Method of imparting uneven shape]
The method for forming the fine irregularities as described above on the surface of the substrate or the intermediate layer on which the resin film of the ink-repellent treatment part is formed is a conventionally known method for modifying the shape of the substrate surface. A method of making the surface state of the intermediate layer into fine irregularities when formed, or a method of combining them can be used.

  As a method for modifying the shape of the substrate surface, for example, a dry etching method can be mentioned. When the substrate is an organic layer, an embossing method for transferring irregularities from an embossing plate or a sheet for pasting to the film surface, etc. It is done.

  As a dry etching method, for example, Hiroshi Mizumachi and Mitsuru Toba “Surface Treatment Technology Handbook-From Adhesion / Painting to Electronic Materials”, Volume 2, Section 3 {NTS Corporation, published in 2000} , Edited by Shigeo Tatsuki et al. “Beam Processing of Polymers-Utilization of Light, Plasma, and Radiation” {CMC Co., Ltd., published in 1986}, supervised by Eiji Kamijo “Plasma / Ion Beam Application and Nanotechnology” Examples include glow discharge etching, flame plasma etching, corona discharge etching, electron beam energy irradiation etching and the like described in Chapter 4 {CMC Corporation, published in 2002}.

  As the embossing method, any of a flat plate press, a continuous belt plate press, and a roll plate press can be adopted. Among these, continuous belt plate press and roll plate press are most preferable as continuous processing of the belt-like material, and roll plate press is most preferable from the viewpoint of the degree of freedom of press pressure and press temperature.

  As the intermediate layer to be surface irregularities, for example, a metal oxide film obtained by applying a sol-gel reaction product obtained by hydrolysis of a hydrolyzable group-containing organometallic compound, and heating or plasma irradiation, light and Examples thereof include a cured film obtained by coating and curing a composition containing a thermosetting compound and fine particles.

[Characteristics of ink-repellent treatment part]
(Surface shape)
The surface of the ink-repellent treatment portion, that is, the shape of the surface having the nozzle hole ejection port, has an arithmetic average roughness (Ra) of surface irregularities of 1 μm or less and a maximum height (Ry) based on JIS B-0601-1994. Is 3 μm or less, and the average surface roughness (Sm) is preferably 15 μm or less. Furthermore, it is preferable that (Ra) is 0.01 to 0.5 μm, the maximum height (Ry) is 2 μm or less, and the average surface unevenness (Sm) is 0.02 to 10 μm or less.
By adopting such a surface state, the ink repellency of the ink repellent portion is sufficiently maintained with respect to wiping that wipes the nozzle opening surface using a wiper made of rubber or cloth.

(Antistatic property)
When charging is applied to the surface of the ink repellent treatment portion and the attenuation is measured, the time required for the charge amount to be ½ of the initial charge (hereinafter referred to as charged voltage half-life) is 60 seconds or less. Is preferred. Particularly when the charged half-life is 30 seconds or less, the antistatic effect is high and desirable. If the charged half-life is within 60 seconds, the antistatic effect after providing the ink repellent portion is excellent, and the dust prevention effect in wiping operation or the like is not reduced. preferable.

Next, a specific method for measuring the charged half-life is described below.
First, the surface is charged by DC corona discharge while monitoring the charged voltage on the surface of the article with an electrostatic potentiometer. Since the charged voltage rises with the discharge and is saturated at a certain potential, this potential is set as the saturated voltage, the discharge is stopped, and the time from the moment until the charged voltage becomes 1/2 of the saturated voltage is measured.

<Inkjet recording apparatus>
The polymerizable resin composition used in the present invention can be used for forming an ink repellent treatment portion of an ink jet recording head that ejects fine droplets. The ink jet recording head having such an ink repellent treatment part can be used for any recording head of the ink jet recording method. Specifically, the contents described in the publications described in the section of the recording head described above can be given.

  Furthermore, the polymerizable resin composition used in the present invention is an appropriate device that ejects fine droplets through a small nozzle other than an inkjet recording device, and an appropriate device that requires liquid repellency on the nozzle plate. Applicable to. These droplets include paints (varnishes), solvents, pharmaceutical fluids and the like.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following, “%” represents “% by mass” unless otherwise specified.

(Polymerizable resin composition)
[Synthesis of fluorine-containing polymerizable polymer]
Synthesis Example 1: Synthesis of fluorinated polymerizable polymer (P-13) 1) Synthesis of monomer corresponding to polymerized unit (F-29) 170 g of 2-perfluorohexylethanol and 22 g of tetra-n-butylammonium hydrogen sulfate were mixed. Then, a sodium hydroxide aqueous solution in which 75 g of sodium hydroxide was dissolved in 112 mL of water was added and stirred at room temperature for 30 minutes. Furthermore, 200 g of chloroethyl vinyl ether was added, and the mixture was heated and stirred at 60 ° C. for 8 hours. Ethyl acetate was added to the reaction solution and washed with water. The organic layer was extracted and dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. Further purification by vacuum distillation yielded 195 g of the title fluorine-containing vinyl ether {also referred to as (Fm-29)} (boiling point 76-79 ° C., 500 Pa).

2) Synthesis of monomer corresponding to polymerized unit (C-2) When 500 g of hydroxyethyl vinyl ether and 50 g of tetra-n-butylammonium hydrogen sulfate were mixed, an aqueous sodium hydroxide solution in which 340 g of sodium hydroxide was dissolved in 380 mL of water was obtained. It was added over 30 minutes and stirred for an additional hour at room temperature. Next, 78.8 g of epichlorohydrin was added and stirred at 60 ° C. for 2 hours. Ethyl acetate was added to the reaction solution and washed with water. The organic layer was extracted and dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. Further purification by distillation under reduced pressure gave 530 g of the title vinyl ether {also referred to as (Cm-2) hereinafter} (boiling point 65 ° C., 532 Pa).

3) Synthesis of fluorinated polymerizable polymer (P-13) In a stainless steel autoclave with an internal volume of 100 mL, ethyl acetate 18.9 g, (Cm-2) 8.65 g (0.060 mol), (Fm- 29) 17.34 g (0.040 mol) and 0.57 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Furthermore, 18.0 g (0.120 mol) of hexafluoropropylene (HFP) {monomer corresponding to the polymerization unit (F-1): hereinafter also referred to as (Fm-1)} is introduced into the autoclave and the temperature is raised to 65 ° C. did. The pressure when the temperature in the autoclave reaches 65 ° C. is 8.4
kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 4.2 kg / cm ² , the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the solvent was removed by decantation, and the precipitated polymer was taken out. Furthermore, this polymer was dissolved in a small amount of ethyl acetate, and the remaining monomer was completely removed by performing reprecipitation twice from hexane. After drying, 35 g of the following fluorine-containing polymerizable polymer (P-13) was obtained. The number average molecular weight of the obtained polymer was 33,000. Other polymers in the present invention can be synthesized in the same manner.

Synthesis Example 2: Synthesis of Comparative Compound (a-1) In an autoclave with a stainless steel stirrer having an internal volume of 100 mL, 40 mL of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether (HEVE) (about 0.167 mol, 50 mol%) and 0.55 g of dilauroyl peroxide was charged, the inside of the system was deaerated and replaced with nitrogen gas. Furthermore, 25 g (about 0.167 mol, 50 mol%) of hexafluoropropylene (HFP = Fm-1) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 5.4 kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 3.2 kg / cm ² , the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Furthermore, this polymer was dissolved in a small amount of ethyl acetate, and the remaining monomer was completely removed by performing reprecipitation twice from hexane. After drying, 28 g of the following fluorinated polymer (a-1) having a molar ratio of 1: 1 of hexafluoropropylene and hydroxyethyl vinyl ether was obtained (the structure is shown below). The number average molecular weight of the obtained polymer was 30,000.

Synthesis Example 3: Synthesis of Comparative Compound (a-4) 1) Synthesis of Fluoropolymerizable Polymer (P-8) In Synthesis Example 2, 14.7 g (about 0.167 mol, 50%) of hydroxyethyl vinyl ether (HEVE) In the same manner as in Synthesis Example 2, except that 24 g (about 0.167 mol, 50 mol%) of the vinyl ether (Cm-2) obtained in 2) of Synthesis Example 1 was used instead of using mol%). The fluorine-containing polymerizable polymer (P-8) was obtained (number average molecular weight 42,000).

2) Synthesis of Comparative Compound (a-4) A mixture obtained by adding 7.5 g of reactive siloxane oligomer (SO-1) having the following structure and 93 g of xylene to 12.1 g of this fluorine-containing polymerizable polymer (P-8). After heating to 120 ° C., 0.01 g of dodecyldimethylamine was added and stirred for 6 hours. After cooling to room temperature, it was reprecipitated in 100 mL of petroleum ether, and the precipitate was collected and dried under reduced pressure to obtain a block copolymer (a-4) with a yield of 12 g. The number average molecular weight of the obtained polymer was 45,000.
In the GPC histogram, no peak corresponding to the reactive siloxane oligomer (SO-1) was observed.

[Preparation of polymerizable resin composition for resin film formation]
Each component shown in Table 1 below was mixed and dissolved in methyl ethyl ketone, and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a polymerizable resin composition for forming a resin film. In addition, the numerical value in a parenthesis represents the mass ratio of each component.

In Table 1 above, each symbol represents the following.
CEL 2021: “Celoxide 2021” (trade name), bifunctional alicyclic epoxy monomer, manufactured by Daicel Chemical Industries, Ltd.
EX252: “Denacol EX-252” (trade name), bisphenol A skeleton bifunctional epoxy monomer, manufactured by Nagase Chemtech Co., Ltd.
EX314: “Denacol EX-314” (trade name), trifunctional epoxy monomer, manufactured by Nagase Chemtech Co., Ltd.
OXT-221: “Aron oxetane OXT-221” (trade name), bifunctional oxetane monomer, manufactured by Toagosei Co., Ltd.).
D110N: “Takenate D110N” (trade name), polyfunctional isocyanate compound, manufactured by Takeda Pharmaceutical Co., Ltd.

  UVI: represents a compound shown below.

  a-2: represents a compound shown below.

  a-3: represents a compound shown below.

[Examples and Comparative Examples]
As shown in FIG. 1, the obtained resin composition is applied onto the surface of the nozzle plate on which the nozzle holes are arranged, and is subjected to a curing treatment as described below to form an ink repellent portion by ink repellent treatment. An ink jet recording head was obtained.

More specifically, the nozzle plate 1 in the obtained head has a water-repellent resin film formed on the periphery (periphery) of the nozzle hole 2 to form an ink-repellent portion 3. In the ink-repellent part 3, in the present invention product, the nozzle hole 2 part of the nozzle plate 1 is protected in advance from the back side of the plate with a positive resist, and the polymerizable resin composition is dried on the surface of the nozzle plate 1 after drying. The film was applied to a thickness of 1 μm, irradiated with ultraviolet rays of 500 mJ / cm ² with a “metal halide lamp”, heated at 120 ° C. for 3 hours to form a resin film, and then the resist was removed. . In this embodiment, the water-repellent resin film is provided after the nozzle holes are created in advance, but the nozzle holes may be provided after the water-repellent resin film is provided on the nozzle plate having no nozzle holes.

  The inkjet recording head of the present invention using the manufactured nozzle plate was confirmed to eject ink droplets stably from all nozzles. Further, the following durability test was conducted. The results are shown in Table 2.

(1) Adhesion As an evaluation of adhesion, the surface of the nozzle plate was dry-wiped 200 times with urethane rubber, and scratches and peeling were observed. A sample having no scratches or peelings was designated as A, a sample having slight scratches but no peelings was designated as B, and a sample having peelings was designated as C.

(2) Liquid repellency The contact angle with pure water was evaluated.

(3) Alkali ink resistance 4 g of copper phthalocyanine sulfonic acid, 9 g of diethylene glycol, 5 g of tetraethylene glycol monobutyl ether, 5 g of glycerin, “Orphine E1010” (trade name) {made by Air Products Co., Ltd.} 2 g and 75 g of water, The operation of immersing the plate in ink adjusted to pH 9 by adding 1 mol / L sodium hydroxide aqueous solution, heating at 70 ° C. for 10 hours, taking out the plate, and performing 10 reciprocating wet wipings with urethane rubber 10 times is repeated. It was. After completion of the work, it was confirmed whether or not there was a difference in liquid repellency before immersion. When the contact angle with respect to pure water after the work is 10 ° or more lower than that before immersion, × is less than 10 °.

  As is apparent from the results shown in Table 2, the inkjet recording head of the present invention formed by using a polymer not containing Si atoms, in which fluorine atoms are efficiently introduced not only in the side chain but also in the main chain, In any case, a high liquid repellency is exhibited when the contact angle with pure water is 100 ° or more. In addition, a water-repellent resin film having excellent discharge suitability and adhesion can be formed by gentle heat treatment at about 120 ° C. On the other hand, the ink jet recording heads of Comparative Examples 1 to 3 obtained by ink repellent treatment with a polymer having no polymerizable group are inferior in alkali ink durability, and do not contain fluorine in the main chain but only contain fluorine in the side chain. The ink jet recording head of Comparative Example 4 which was initially ink-treated with a polymer was inferior in ink repellency. In the ink jet recording head of Comparative Example 5 obtained by ink repellent treatment with a polymer having a polysiloxane structure, the polysiloxane structure was It can be seen that the ink deteriorates and the ink durability is poor.

FIG. 1 is an enlarged cross-sectional view showing a main part of the ink jet recording head of the present invention prepared in the embodiment.

Explanation of symbols

1: Nozzle plate 2: Nozzle hole 3: Ink repellent part

Claims (6)

In an ink jet recording head having a discharge port for discharging a recording liquid, and at least the periphery of the discharge port is subjected to ink repellent treatment,
The ink repellent processing part of the recording head is
A polymerizable resin composition comprising a polymer unit having a perfluoroalkyl group in a main chain and a side chain and a polymer unit having a cationic polymerizable group, and a polymer containing no Si atom in the molecule as an essential component An ink jet recording head comprising: 2. The ink jet recording head according to claim 1, wherein the polymer contains a polymer unit represented by the following general formula (1) as a polymer unit having a perfluoroalkyl group in the main chain and side chain.
General formula (1):

In the formula, R _f ¹¹ represents a fluorine atom, a C 1-8 perfluoroalkyl group or —OR _f ¹² group, and the R _f ¹² group represents a C 1-20 perfluoroalkyl group. The ink jet recording head according to claim 1 or 2, wherein the polymer contains a polymer unit represented by the following general formula (2) as a polymer unit having a perfluoroalkyl group in the side chain.
General formula (2):

In the formula, R _f ²¹ represents a C 1-20 perfluoroalkyl group, L ²¹ represents a C 1-20 linking group, and m is 0 or 1. The ink jet recording head according to any one of claims 1 to 3, wherein the polymer contains a polymer unit represented by the following general formula (3) as a polymer unit having a cationic polymerizable group.
General formula (3):

In the formula, L ³¹ represents a linking group having 1 to 20 carbon atoms, X ³¹ represents an organic group containing a cationic polymerizable group, and n is 0 or 1.   The polymerizable resin composition further contains at least one of a curing agent and a curing accelerator, and the crosslinked body is formed by coating and curing the composition for forming a cured film. The inkjet recording head in any one of -4. An ink jet recording apparatus equipped with an ink jet recording head, wherein the ink jet recording head is the ink jet recording head according to any one of claims 1 to 5.

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