Adhesive tape and method for manufacturing nozzle plate of inkjet head using the adhesive tape

Abstract

To provide an adhesive tape which is used in such a manner that the tape is bonded to a liquid repellent layer formed on a base material for nozzle plate of an ink jet head, and can manufacture the nozzle plate, in which process tolerance of a nozzle hole is good, with good yielding percentage when performing outer shape processing and nozzle hole processing with laser beam.SOLUTION: An adhesive layer contains a process oil comprising styrene-isoprene-styrene block copolymer and petroleum hydrocarbon, and a tackifying resin containing at least one kind from a group comprising aliphatic hydrocarbon resin, aliphatic aromatic hydrocarbon resin, hydrogenated petroleum resin and terpene resin, a storage elastic modulus (G')100Hz of the adhesive layer at 23°C when measuring a dynamic viscoelasticity under the condition of a frequency of 100 Hz and a rate of temperature rise of 2°C / min has a range of 3.0×105 Pa or more and 6.5×105 Pa or less, and a content of the tackifying resin in the adhesive layer has a range of 23 mass parts or more and 78 mass parts or less to the styrene-isoprene-styrene block copolymer of 100 mass parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an adhesive tape. Specifically, when forming a plurality of nozzle holes on a base material for a nozzle plate of an inkjet head by a laser processing method, on which a liquid-repellent layer is formed on its surface, it is an adhesive tape for being attached to the surface of the liquid-repellent layer of the base material for the nozzle plate and used, and a method for manufacturing a nozzle plate of an inkjet head using the adhesive tape.

Background Art

[0002] An inkjet head that discharges ink in the form of fine droplets from an ink discharge port, which is used for performing image recording on a recording medium such as paper, cloth, or a resin sheet, highly requires the straightness of the ink droplets discharged from the discharge port in order to achieve high-quality image recording. When ink adheres to the periphery of the discharge port, problems such as the ink droplets discharged from the discharge port bending in direction, the straightness of the ink droplets being impaired, the discharge amount decreasing, or the ink not being discharged occur. As a result, the resolution of the recorded image is significantly reduced. For this reason, a non-ink film (liquid-repellent layer) is usually formed on the surface of the nozzle plate of the inkjet head (the surface on the ink discharge side) to impart liquid-repellent properties. By doing so, ink is prevented from adhering to the peripheral portion of the discharge port, and the straightness of the ink during ink discharge is not impaired and the discharge amount does not decrease.

[0003] As an inkjet head nozzle plate having an ink repellent treatment applied to the surface of the nozzle plate or an inkjet head using the nozzle plate, various types have been disclosed so far. For example, in Patent Document 1, a dispersion of tetrafluoroethylene - hexafluoropropylene copolymer (FEP) for ink repellent treatment is applied to a nozzle plate substrate made of polyimide, an adhesive sheet (adhesive tape) is bonded to the coated surface, nozzle holes are drilled by irradiating with an excimer laser, and then the adhesive sheet (adhesive tape) is peeled off and heat - treated to form an inkjet head nozzle plate having an ink repellent film.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the ejection characteristics (ejection volume, ejection speed, landing accuracy) of an inkjet head are greatly influenced by variations in the size of the nozzle holes of the nozzle plate, shape uniformity, processing position accuracy, etc. of the nozzle plate. Therefore, when manufacturing the nozzle plate of an inkjet head, the adhesive sheet (adhesive tape) used by attaching to the liquid - repellent layer (ink - repellent film, ink - repellent treatment surface) of the base material for the nozzle plate of the inkjet head, especially when processing the base material for the nozzle plate using a laser, (1) When performing outer shape (cutting) processing on a nozzle plate of a predetermined size from the base material for the nozzle plate or when cleaning after the outer shape processing, it should be possible to temporarily fix the base material for the nozzle plate and its cut - off and separated pieces so that they do not shift in position. (2) When drilling nozzle holes in each of the outer - shape - processed base materials for the nozzle plate, it should not affect the processing accuracy of the holes on the nozzle outlet side (hole shape, hole clogging, variations in hole diameter, etc.). is required.

[0006] In Patent Document 1, it is described that rubber-based materials such as natural rubber, polyisoprene rubber, styrene-butadiene rubber, and polyisobutylene are preferably used as the material constituting the pressure-sensitive adhesive layer of the above-mentioned pressure-sensitive adhesive sheet (pressure-sensitive adhesive tape). However, the specific pressure-sensitive adhesive composition and physical properties of the pressure-sensitive adhesive layer have not been studied. Further, actually, when laser processing is performed using a pressure-sensitive adhesive composition mainly composed of a styrene-isoprene-styrene copolymer (SIS) as the pressure-sensitive adhesive composition of the pressure-sensitive adhesive layer as a rubber-based material, sagging or burrs may occur at the edge portion of the nozzle on the outlet side of the nozzle hole, and variations may occur in the diameter of the nozzle hole. In this case, the breakage of the ink ejected from the nozzle hole deteriorates, and ink that sags and blocks the ink ejection port of the nozzle hole adheres to the ink ejection surface of the nozzle hole, causing a problem that the nozzle hole becomes clogged. On the other hand, clogging of the pressure-sensitive adhesive composition was also observed in the nozzle holes, and the yield during laser processing was deteriorated. Therefore, depending on the type of the pressure-sensitive adhesive sheet (pressure-sensitive adhesive tape) used, it may not be possible to fully satisfy the above requirements, and there is still room for improvement and consideration regarding the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (pressure-sensitive adhesive tape) applied when manufacturing the nozzle plate of the inkjet head.

[0007] The present invention solves the above-mentioned conventional problems, and in order to perform external shape processing and nozzle hole processing on a base material for a nozzle plate of an inkjet head having a liquid-repellent layer formed on its surface by laser, it is a pressure-sensitive adhesive tape that is attached to and used for the base material for the nozzle plate. During external shape processing or cleaning after external shape processing, there is no displacement of the base material for the nozzle plate or its cut and separated pieces, and during nozzle hole processing, a nozzle hole with good processing accuracy can be drilled, that is, an object is to provide a pressure-sensitive adhesive tape capable of manufacturing a high-quality nozzle plate with good yield. Another object is to provide a method for manufacturing a nozzle plate of an inkjet head using the pressure-sensitive adhesive tape.

Means for Solving the Problems

[0008] The pressure-sensitive adhesive tape of the present invention is used by being attached to a liquid-repellent layer formed on a base material for a nozzle plate of an inkjet head when performing external shape processing and nozzle hole processing on the base material for the nozzle plate by laser. The pressure-sensitive adhesive tape includes a base material and a pressure-sensitive adhesive layer laminated on one surface of the base material. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape A) A styrene-isoprene-styrene block copolymer, B) A process oil composed of a petroleum-based hydrocarbon, C) A tackifier resin containing at least one selected from the group consisting of an aliphatic hydrocarbon resin, an aliphatic / aromatic copolymer hydrocarbon resin, a hydrogenated petroleum resin, and a terpene resin and contains When the dynamic viscoelasticity of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is measured in a shear mode under the conditions of a frequency of 100 Hz and a temperature increase rate of 2 °C / min, the storage elastic modulus (G’) at 23 °C 100Hz is in the range of 3.0×10 5 Pa or more and 6.5×10 5 Pa or less, and The content of the tackifier resin in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is in the range of 23 parts by mass or more and 78 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer, which is characterized.

[0009] In a certain preferred embodiment, the styrene-isoprene-styrene block copolymer has a styrene content in the range of 14% by mass or more and 25% by mass or less, and a styrene-isoprene diblock content in the range of 12% by mass or more and 78% by mass or less.

[0010] In a certain preferred embodiment, the softening point of the tackifier resin is in the range of 80 °C or more and 135 °C or less.

[0011] In a certain preferred embodiment, the content of the process oil composed of the petroleum-based hydrocarbon is in the range of 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer.

[0012] In a preferred embodiment, the liquid repellent layer has a contact angle of distilled water on the surface of the liquid repellent layer of 110° or more and 180° or less.

[0013] In a preferred embodiment, the liquid repellent layer is composed of a fluorine-based compound, and the fluorine-based compound is (1) a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoroalkyl group, (2) a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoropolyether group, (3) a mixture containing a compound having a perfluoroalkyl group, or (4) a mixture containing a compound having a perfluoropolyether group.

[0014] In a preferred embodiment, the pressure-sensitive adhesive tape has a tack of the pressure-sensitive adhesive layer in the range of 6 or more and 14 or less.

[0015] Further, the present invention provides a step of bonding any one of the above-described pressure-sensitive adhesive tapes to a base material for a nozzle plate of an inkjet head having a liquid repellent layer formed on the surface so that the pressure-sensitive adhesive layer and the liquid repellent layer face each other; a step of machining the outer shape of the base material for the nozzle plate of the inkjet head into a nozzle plate having a desired size to be mounted on the inkjet head using a laser on the pressure-sensitive adhesive tape; a step of forming nozzle holes in the outer shape machined nozzle plate using a laser; and a step of peeling the pressure-sensitive adhesive tape from the obtained nozzle plate; and provides a method for manufacturing a nozzle plate of an inkjet head including the above steps.

Advantages of the Invention

[0016] According to the present invention, for performing external shape processing and nozzle hole processing on a base material for a nozzle plate of an inkjet head having a liquid-repellent layer formed on its surface by laser, when it is used by being attached to the liquid-repellent layer formed on the base material for the nozzle plate, it is possible to provide an adhesive tape for temporary fixing that can produce a high-quality nozzle plate with good processing accuracy of the nozzle holes with a good yield. Further, it is possible to provide a method for manufacturing a nozzle plate of an inkjet head using the adhesive tape, which can produce a high-quality nozzle plate with a good yield.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described. [Configuration of Adhesive Tape 1] FIG. 1 is a diagram showing an example of the configuration of the adhesive tape 1 to which the present embodiment is applied. As shown in FIG. 1, the adhesive tape 1 of the present embodiment includes a base material 2 and an adhesive layer 3 laminated on one surface of the base material 2. Further, the adhesive tape 1 of the present embodiment includes a release liner 4 having releasability with respect to the adhesive layer 3 on the adhesive layer 3. In the description of the present embodiment, the state where the release liner 4 is peeled off (the laminated structure of the base material 2 and the adhesive layer 3) may be referred to as the adhesive tape 1.

[0019] [Usage method of the adhesive tape 1] FIG. 2 is a diagram showing the usage state of the adhesive tape to which the present embodiment is applied. As shown in FIG. 2, the adhesive tape 1 of the present embodiment is used in a state of a laminate 20 by bonding the adhesive layer 3 side to the liquid-repellent layer 6 formed on the base material 5 for nozzle plate of an inkjet head in a state where the release sheet 4 is peeled off in order to protect the liquid-repellent layer 6 formed on the base material 5 for nozzle plate when manufacturing the nozzle plate of the inkjet head by laser processing.

[0020] More specifically, when the base material 5 for nozzle plate of the inkjet head on which the liquid-repellent layer 6 is formed is cut and nozzle holes are processed into a predetermined size by laser, the adhesive tape 1 of the present embodiment is used in a state of a laminate 20 by bonding the adhesive layer 3 side of the adhesive tape 1 to the liquid-repellent layer 6 formed on the base material 5 for nozzle plate in order to prevent damage to the surface of the liquid-repellent layer 6 formed on the base material 5 for nozzle plate and to prevent the entry of dust into the nozzle holes while performing nozzle hole processing with high precision. That is, it is used as a temporary fixing protection sheet for the base material 5 for nozzle plate on which the liquid-repellent layer 6 is formed.

[0021] FIG. 3 is a cross-sectional view showing the state of laser nozzle hole machining on the base material 5 for a nozzle plate provided with a liquid-repellent layer 6 to which the pressure-sensitive adhesive tape 1 to which the present embodiment is applied is attached. By irradiating the laminate 20 with laser light L from the side of the base material 5 for the nozzle plate, a predetermined number of through holes are formed by ablation that penetrates the base material 5 for the nozzle plate and the liquid-repellent layer 6. The holes formed in the laminated portion of the base material 5 for the nozzle plate and the liquid-repellent layer 6 by these through holes become the nozzle holes h. Therefore, the number of through holes is the same as the number of nozzle holes h provided in the nozzle plate 30 to be produced, but only one through hole is shown here. When forming through holes in the laminate 20 in this way, as shown in FIG. 3, the nozzle plate base material 5, the liquid-repellent layer 6, and the adhesive layer 3 of the pressure-sensitive adhesive tape 1 are penetrated, but hole machining is performed to such an extent that the base material 2 of the pressure-sensitive adhesive tape 1 is not penetrated. By doing so, the machining accuracy on the nozzle outlet side can be further improved. And the pressure-sensitive adhesive tape 1 of the present embodiment is peeled off from the surface of the liquid-repellent layer 6 provided on the base material 5 for the nozzle plate after a predetermined laser processing is completed.

[0022] Subsequently, the configuration of each layer of the pressure-sensitive adhesive tape 1 to which the present embodiment is applied will be described in detail. <Base material 2> The base material 2 of the pressure-sensitive adhesive tape 1 of the present embodiment is not particularly limited, but is preferably a flexible base material. For example, (meth)acrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyether ketone, polysulfone, polyethersulfone, polyimide, polyetherimide, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyimide-based thermoplastic elastomer, aramid-based thermoplastic elastomer, silicone-based elastomer, epoxy resin, etc. A resin film formed from a resin material containing the above, and further, a resin film formed by laminating two or more layers of the above resin materials can be mentioned. Among these resin materials, polyethylene terephthalate and polyimide are particularly preferably used from the viewpoints of versatility and mechanical properties.

[0023] Further, the thickness of the base material 2 of the present embodiment is not particularly limited, but is preferably in the range of, for example, 10 μm or more and 1,000 μm or less, more preferably in the range of 20 μm or more and 500 μm or less, and particularly preferably in the range of 50 μm or more and 300 μm or less from the viewpoint of handleability.

[0024] Furthermore, the base material 2 of the present embodiment may be surface-treated as necessary for the purpose of improving the adhesion to the adhesive layer 3. The surface treatment applied to the base material 2 is not particularly limited, and examples thereof include corona treatment and plasma treatment. Further, an anchor coating agent or the like may be applied to the surface of the base material 2.

[0025] <Adhesive layer 3> The pressure-sensitive adhesive layer 3 of the present embodiment is composed of a styrene-isoprene-styrene block copolymer (SIS), a process oil composed of a petroleum-based hydrocarbon, and a tackifier resin containing at least one selected from the group consisting of an aliphatic hydrocarbon resin, an aliphatic / aromatic copolymer hydrocarbon resin, a hydrogenated petroleum resin, and a terpene resin, and is composed of a pressure-sensitive adhesive composition containing the tackifier resin in a range of 23 parts by mass or more and 78 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer.

[0026] And the pressure-sensitive adhesive layer 3 composed of the above pressure-sensitive adhesive composition has the following dynamic viscoelastic properties with respect to a specific frequency. That is, the pressure-sensitive adhesive layer 3 of the present embodiment has a storage elastic modulus (G’) at 23°C when measuring dynamic viscoelasticity under the conditions of a frequency of 100 Hz and a temperature rising rate of 2°C / min in a shear mode. 100Hz is in the range of 3.0×10 5 Pa or more and 6.5×10 5 Pa or less, more preferably 3.6×10 5 Pa or more and 5.8×10 5 Pa or less, still more preferably 4.6×10 5 Pa or more and 5.5×10 5 Pa or less.

[0027] The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 3 and the dynamic viscoelastic properties of the pressure-sensitive adhesive layer 3 with respect to a specific frequency in the present embodiment were found by the present inventors using a pressure-sensitive adhesive tape 1 provided with a pressure-sensitive adhesive layer 3 composed of various styrene-isoprene-styrene block copolymer (SIS)-based pressure-sensitive adhesive compositions, and studying in detail the relationship with the temporary fixing force, the shape processing property, and the processing accuracy of the nozzle hole h in nozzle hole processing with respect to the substrate 5 for a nozzle plate on which the liquid-repellent layer 6 was formed. That is, when manufacturing a nozzle plate of an inkjet head by laser processing, an excimer laser having a repetition frequency usually set to about several tens to several hundreds Hz is preferably used as the laser. That is, only the pressure-sensitive adhesive tape 1 provided with a specific pressure-sensitive adhesive layer 3 showing an appropriate hardness (storage elastic modulus) with respect to vibrations having a repetition frequency of several tens to several hundreds Hz can suppress minute fluctuations of the member to be processed during laser light irradiation, and stable ablation processing with an excimer laser having a repetition frequency of about several tens to several hundreds Hz becomes possible with respect to the substrate 5 for a nozzle plate on which the liquid-repellent layer 6 is formed, and it was found to have good shape processing property and nozzle hole processing property, thus leading to the completion of the present invention. In the present invention, for convenience, the repetition frequency is set to 100 Hz.

[0028] The storage elastic modulus (G’) at 23°C 100Hz is less than 3.0×10 5 Pa, for example, when applied to the pressure-sensitive adhesive layer 3 for laser processing with a repetition frequency of 100 Hz, due to the hardness of the pressure-sensitive adhesive layer 3 becoming excessively low, the substrate 5 for the nozzle plate tends to shake on the pressure-sensitive adhesive layer 3 during laser processing, and further the pressure-sensitive adhesive layer 3 tends to deform, making stable ablation processing difficult, and there is a risk that the shape of the nozzle hole h deteriorates or the nozzle hole h becomes clogged during nozzle hole processing by laser. In addition, when the pressure-sensitive adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (glue residue) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 and the edge portion of the nozzle hole h.

[0029] On the other hand, the storage elastic modulus (G’) at 23°C 100Hz is 6.5×105 When it exceeds Pa, in the pressure-sensitive adhesive layer 3 composed of a pressure-sensitive adhesive composition with a low content of tackifier resin, due to the excessive hardness of the pressure-sensitive adhesive layer 3, the temporary fixing force on the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate tends to decrease. Therefore, during a series of processing steps, the base material 5 for the nozzle plate may peel off from the adhesive tape 1, or the base material 5 for the nozzle plate and its cut and separated pieces may be displaced during laser processing or cleaning. Also, peeling may occur at the interface between the pressure-sensitive adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a poor shape of the nozzle hole h.

[0030] The thickness of the pressure-sensitive adhesive layer 3 of the present embodiment is not particularly limited. However, from the viewpoints of the temporary fixing force on the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate and the processing accuracy by laser, for example, a range of 5 μm or more and 100 μm or less is preferable, and a range of 10 μm or more and 50 μm or less is more preferable.

[0031] (styrene-isoprene-styrene block copolymer) The styrene-isoprene-styrene block copolymer (SIS) contained in the pressure-sensitive adhesive layer 3 of the present embodiment is composed of a polystyrene block and a polyisoprene block, and includes a styrene-isoprene diblock copolymer and a styrene-isoprene-styrene triblock copolymer. The styrene-isoprene-styrene block copolymer (SIS) has the maximum absorption wavelengths of styrene and isoprene, which are its constituent units, at around 260 to 270 nm and 220 to 225 nm, respectively, for ultraviolet rays, and is likely to absorb laser light oscillating in the ultraviolet to vacuum ultraviolet region. Therefore, it can be a pressure-sensitive adhesive material suitable for photochemical ablation.

[0032] The styrene-isoprene-styrene block copolymer of the present embodiment is not particularly limited. However, from the viewpoint of achieving both the adhesion to the liquid-repellent layer 6 and an appropriate hardness against vibrations with a repetition frequency of the laser in the range of several tens to several hundreds of Hz, the styrene-isoprene diblock amount (SI diblock amount) is preferably 12% by mass or more and 78% by mass or less, more preferably 15% by mass or more and 55% by mass or less, and even more preferably 25% by mass or more and 35% by mass or less. When the SI diblock amount in the styrene-isoprene-styrene block copolymer is less than 12% by mass, the adhesive layer 3 tends to become hard, especially when the content of the process oil in the adhesive layer 3 is small. In this case, since the temporary fixing force to the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate tends to decrease, during a series of processing steps, the base material 5 for the nozzle plate may peel off from the adhesive tape 1, or the base material 5 for the nozzle plate or its cut and separated pieces may be displaced during laser processing or cleaning. Also, peeling may occur at the interface between the adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a poor shape of the nozzle hole h.

[0033] On the other hand, when the SI diblock amount in the styrene-isoprene-styrene block copolymer exceeds 78% by mass, the adhesive layer 3 tends to become soft, especially when the content of the process oil in the adhesive layer 3 is large. In this case, due to the excessive decrease in the hardness of the adhesive layer 3 as an adhesive layer applicable to laser processing with a repetition frequency in the range of several tens to several hundreds of Hz, the base material 5 for the nozzle plate tends to shake on the adhesive layer 3 during laser processing, and further, the adhesive layer 3 tends to deform, making stable ablation processing difficult, and there is a possibility that the shape of the nozzle hole h deteriorates or clogging of the nozzle hole h occurs during nozzle hole processing by laser. Also, when the adhesive tape 1 is peeled off, there is a possibility of contamination due to adhesive residue (adhesive remaining) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 or at the edge portion of the nozzle hole h.

[0034] Regarding the above-mentioned malfunction phenomenon, although the details are not clear, it is presumed to be due to the following reasons. For example, when the drilling of the base material 5 for the nozzle plate by excimer laser irradiation progresses and the adhesive layer 3 begins to be exposed after a certain pulse shot, the surface layer of the adhesive layer 3 that absorbs photons with a certain intensity or more due to the irradiation of each pulse of the excimer laser is ablated. However, a considerable amount of photons are also absorbed in the layers below that. In this layer, some of the chemical bonds of the adhesive are broken, but the decomposition fragments cannot be completely gasified and do not evaporate. Also, not all of the energy absorbed by light is used for bond cleavage, and it dissipates as thermal energy. In the limited layer below ablation in the adhesive layer 3, a temporarily high-temperature layer is formed, and a certain layer of the film melts, but it is an extremely thin layer, and the total amount of heat is not much, so it solidifies immediately. Therefore, if the adhesive layer 3 is soft, minute thermal deformation occurs in the part of the adhesive layer 3 adjacent to the edge part (rim part) of the nozzle hole h of the base material 5 for the nozzle plate and in the side part of the through-hole of the adhesive layer 3 close to the edge part. The deformed parts are gradually deposited for each irradiation pulse and finally solidify in the deformed state. Then, the ablation process for each pulse shot becomes unstable, and there is a risk that the shape of the nozzle hole h deteriorates during nozzle hole processing by the laser or that the nozzle hole h becomes clogged. Also, when the adhesive tape 1 is peeled off, it is presumed that the adhesive caught on the edge part of the nozzle hole h of the base material 5 for the nozzle plate is torn and adhesive residue (glue residue) is likely to occur.

[0035] Also, the styrene content in the styrene-isoprene-styrene block copolymer contained in the adhesive layer 3 is preferably in the range of 14% by mass or more and 25% by mass or less, more preferably in the range of 14% by mass or more and 20% by mass or less, from the viewpoint of achieving both the adhesive force to the liquid-repellent layer 6 and an appropriate hardness against vibrations with a repetition frequency of the laser in the range of several tens to several hundreds of Hz.

[0036] When the styrene content in the styrene-isoprene-styrene block copolymer is less than 14% by mass, especially when the content of the process oil in the pressure-sensitive adhesive layer 3 is high, the pressure-sensitive adhesive layer 3 tends to become overly soft. In this case, due to the excessive low hardness of the pressure-sensitive adhesive layer 3 as applied to laser processing with a repetition frequency of several tens to several hundreds of Hz, the base material 5 for the nozzle plate tends to shake on the pressure-sensitive adhesive layer 3 during laser processing. As a result, the pressure-sensitive adhesive layer 3 is more likely to deform, making stable ablation processing difficult, and there is a risk that the shape of the nozzle hole h deteriorates or the nozzle hole h becomes clogged during nozzle hole processing by laser. In addition, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (adhesive remaining) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 or the edge portion of the nozzle hole h.

[0037] On the other hand, when the styrene content in the styrene-isoprene-styrene block copolymer exceeds 25% by mass, especially when the content of the process oil in the pressure-sensitive adhesive layer 3 is low, the pressure-sensitive adhesive layer 3 tends to become overly hard. In this case, since the temporary fixing force for the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate decreases, there is a risk that the base material 5 for the nozzle plate peels off from the adhesive tape 1 during a series of processing steps, or that the base material 5 for the nozzle plate and its cut and separated pieces are displaced during laser processing or cleaning. In addition, peeling occurs at the interface between the pressure-sensitive adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing cannot be performed, and there is a risk that the shape of the nozzle hole h deteriorates.

[0038] Furthermore, the weight average molecular weight (Mw) of the styrene-isoprene-styrene block copolymer contained in the pressure-sensitive adhesive layer 3 of the present embodiment is not particularly limited, but is preferably in the range of, for example, 150,000 or more and 250,000 or less. When the weight average molecular weight (Mw) of the styrene-isoprene-styrene block copolymer is less than 50,000, especially when the content of process oil and tackifier resin in the pressure-sensitive adhesive layer 3 is large, the cohesive force of the pressure-sensitive adhesive layer 3 decreases. Also, due to the excessive softness of the pressure-sensitive adhesive layer 3 as an adhesive layer applied to laser processing with a repetition frequency of several tens to several hundreds of Hz, the base material 5 for the nozzle plate tends to shake on the pressure-sensitive adhesive layer 3 during laser processing. Furthermore, since the pressure-sensitive adhesive layer 3 is more likely to deform, stable ablation processing becomes difficult, and there is a risk that the shape of the nozzle hole h deteriorates or the nozzle hole h becomes clogged during nozzle hole processing by laser. In addition, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (adhesive remaining) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 and the edge portion of the nozzle hole h. This is the same as the above-mentioned presumed reason. In this case, however, the level of this defect is more likely to be more prominent due to the decrease in cohesive force.

[0039] On the other hand, when the weight average molecular weight (Mw) of the styrene-isoprene-styrene block copolymer exceeds 250,000, especially when the content of process oil in the pressure-sensitive adhesive layer 3 is small, the pressure-sensitive adhesive layer 3 tends to become hard. In this case, the temporary fixing force for the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate decreases, and during a series of processing steps, there is a risk that the base material 5 for the nozzle plate peels off from the adhesive tape 1, or that the base material 5 for the nozzle plate and its cut and separated pieces are displaced during laser processing or cleaning. Also, peeling may occur at the interface between the pressure-sensitive adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a risk that the shape of the nozzle hole h deteriorates.

[0040] Further, the adhesive layer 3 containing a styrene-isoprene-styrene block copolymer may contain other synthetic rubbers, natural rubbers, etc. within a range that does not impair its properties, in addition to the styrene-isoprene-styrene block copolymer. Further, the adhesive layer 3 may contain additives such as an antioxidant, a heat stabilizer, a colorant, etc., as necessary.

[0041] (Process oil composed of petroleum-based hydrocarbons) The adhesive layer 3 of the present embodiment contains a process oil composed of petroleum-based hydrocarbons. The process oil composed of petroleum-based hydrocarbons blended with the above styrene-isoprene-styrene block copolymer is for facilitating the processing of the styrene-isoprene-styrene block copolymer and imparting tack and plasticity to the styrene-isoprene-styrene block copolymer, and acts as a softening agent.

[0042] The process oil composed of petroleum-based hydrocarbons is generally called a rubber compounding oil and includes an extender oil (extending oil) and a process oil (processing oil). The process oil composed of petroleum-based hydrocarbons has its molecules penetrate between the styrene-isoprene-styrene block copolymer molecules, improving lubricity. As a result, the fluidity between the molecules of the styrene-isoprene-styrene block copolymer increases, and the internal friction between the molecules is reduced. As a result, in each step of producing the adhesive layer containing the above styrene-isoprene-styrene block copolymer, heat generation due to friction between molecules is reduced, and processability is improved. Further, the adhesive properties of the adhesive layer at low temperatures are improved.

[0043] The process oil composed of petroleum-based hydrocarbons is generally a mixture of paraffinic hydrocarbons, naphthenic hydrocarbons, and aromatic hydrocarbons, and is classified into paraffinic process oil, naphthenic process oil, and aromatic hydrocarbon-based process oil according to the mixing ratio. These process oils can be used alone or in combination. Among these process oils, it is preferable to use a process oil having a high specific gravity and a high boiling point because of its good affinity with styrene-isoprene-styrene block copolymer.

[0044] Paraffinic process oil and naphthenic process oil can be obtained, for example, by subjecting paraffin-base crude oil, intermediate-base crude oil or naphthene-base crude oil to atmospheric distillation, or by subjecting the residue oil of atmospheric distillation to vacuum distillation and purifying the distillate oil obtained by a known method. Further, deep dewaxed oil obtained by further subjecting to deep dewaxing treatment after purification, and hydrogenated oil obtained by hydrogenation treatment may also be used. The purification method is not particularly limited, and a known method can be adopted.

[0045] Also, a commercially available product may be used as the process oil composed of petroleum hydrocarbons. Specific examples of paraffinic process oil include NA Solvent (trade name) manufactured by NOF Corporation, PW-380 (trade name) manufactured by Idemitsu Kosan Co., Ltd., Diana Freshia S32 (trade name), PS-32 (trade name), IP-Solvent 2835 (trade name), Diana Process Oil PW-90 (trade name), Neo Thiozol (trade name) manufactured by Sanko Chemical Industries, Ltd., and the like.

[0046] Specific examples of naphthenic process oil include Diana Freshia N28 (trade name), Diana Freshia U46 (trade name), Diana Process Oil NR (trade name) manufactured by Idemitsu Kosan Co., Ltd., Shellflex 371N (trade name) manufactured by Shell Chemical Co., Ltd., and the like.

[0047] Furthermore, specific examples of aromatic hydrocarbon-based process oil include Diana Process Oil AC-460 (trade name) manufactured by Idemitsu Kosan Co., Ltd., and the like.

[0048] The content of the process oil composed of the above petroleum-based hydrocarbon is not particularly limited, but it is preferably in the range of 2 parts by mass or more and 20 parts by mass or less, more preferably 3 parts by mass or more and 18 parts by mass or less, and still more preferably 4 parts by mass or more and 8 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer. When the content of the process oil composed of the petroleum-based hydrocarbon is too small, especially when the amount of the SI diblock in the styrene-isoprene-styrene block copolymer is small or the amount of styrene is large, the adhesive layer 3 tends to become hard. In this case, since the temporary fixing force with respect to the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate decreases, during a series of processing steps, the base material 5 for the nozzle plate may peel off from the adhesive tape 1, or the base material 5 for the nozzle plate or its cut and separated pieces may be displaced during laser processing or cleaning. Further, peeling may occur at the interface between the adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and there is a risk that the shape of the nozzle hole h deteriorates and stable ablation processing cannot be performed.

[0049] On the other hand, when the content of the process oil composed of the petroleum-based hydrocarbon exceeds 20 parts by mass, especially when the amount of the SI diblock in the styrene-isoprene-styrene block copolymer is large or the amount of styrene is small, the adhesive layer 3 tends to become soft. In this case, the cohesive force of the adhesive layer 3 decreases, and also, due to the hardness of the adhesive layer 3 as applied to laser processing with a repetition frequency of several tens to several hundreds of Hz being excessively low, the base material 5 for the nozzle plate tends to shake on the adhesive layer 3 during laser processing, and further, the adhesive layer 3 tends to be deformed, making stable ablation processing difficult, and there is a risk that the shape of the nozzle hole h deteriorates or clogging of the nozzle hole h occurs during nozzle hole processing by laser. Further, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (adhesive remaining) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 or the edge portion of the nozzle hole h. This is the same as the above-described presumed reason, but in this case, the defect level tends to be more prominent due to the decrease in the cohesive force.

[0050] (Pressure-sensitive adhesive resin) The pressure-sensitive adhesive layer 3 of the present embodiment contains, as a pressure-sensitive adhesive resin, at least one resin selected from the group consisting of an aliphatic hydrocarbon resin, an aliphatic / aromatic copolymer hydrocarbon resin, a hydrogenated petroleum resin, and a terpene resin. These may be used alone or in combination. The pressure-sensitive adhesive resin is a component that auxiliary improves the adhesive force of the pressure-sensitive adhesive resin, and is an oligomer having a mass average molecular weight (Mw) of usually less than 10,000, and the mass average molecular weight (Mw) is preferably in the range of 400 or more and 4,000 or less, more preferably in the range of 800 or more and 1,500 or less. By containing these pressure-sensitive adhesive resins in the pressure-sensitive adhesive layer 3 containing the styrene-isoprene-styrene block copolymer within an appropriate content range described later, compared with the case where these pressure-sensitive adhesive resins are not contained, the adherend, that is, the adhesive force (fixing force) to the liquid-repellent layer 6 can be improved, and the elasticity against vibrations with a repetition frequency of several tens to several hundreds of Hz during laser processing can be improved. That is, it is possible to achieve both the temporary fixing force to the base material for the nozzle plate on which the liquid-repellent layer of the inkjet head is formed and the stable ablation processability by a laser with a repetition frequency of several tens to several hundreds of Hz.

[0051] The aliphatic hydrocarbon resin used as the pressure-sensitive adhesive resin of the present embodiment is not particularly limited. For example, Quintone R100 (trade name, softening point: 96°C), Quintone M100 (trade name, softening point: 95°C), Quintone A100 (trade name, softening point: 100°C) manufactured by Nippon Zeon Co., Ltd., T-REZ RB093 (trade name, softening point: 93°C), T-REZ RB100 (trade name, softening point: 100°C), T-REZ RC100 (trade name, softening point: 100°C), T-REZ RC115 (trade name, softening point: 115°C) manufactured by TonenGeneral Sekiyu K.K. can be used.

[0052] In addition, the aliphatic / aromatic copolymer hydrocarbon resin used as the tackifying resin in the present embodiment is not particularly limited. For example, Quintone N180 (trade name, softening point: 80°C), Quintone S195 (trade name, softening point: 94°C), Quintone D100 (trade name, softening point: 99°C), Quintone E200SN (trade name, softening point: 102°C) manufactured by Nippon Zeon Co., Ltd., T-REZ RD104 (trade name, softening point: 104°C) manufactured by TonenGeneral Sekiyu K.K., etc. can be used.

[0053] Furthermore, the hydrogenated petroleum resin used as the tackifying resin in the present embodiment is not particularly limited. For example, Alcon P-100 (trade name, softening point: 100°C), Alcon P-115 (trade name, softening point: 115°C), Alcon P-125 (trade name, softening point: 125°C) manufactured by Arakawa Chemical Industries, Ltd., T-REZ HA085 (trade name, softening point: 85°C), T-REZ HA103 (trade name, softening point: 103°C), T-REZ HA125 (trade name, softening point: 125°C) manufactured by TonenGeneral Sekiyu K.K., etc. can be used.

[0054] Furthermore, the terpene resin used as the tackifying resin in the present embodiment is not particularly limited. For example, YS Resin PX800 (trade name, softening point: 80°C), YS Resin PX1000 (trade name, softening point: 100°C), YS Resin PX1150 (trade name, softening point: 115°C), YS Resin PX1250 (trade name, softening point: 125°C), YS Resin TO115 (trade name, softening point: 115°C) manufactured by Yasuhara Chemical Co., Ltd., etc. can be used.

[0055] Among the above-mentioned tackifying resins, from the viewpoint of achieving both the temporary fixing force to the liquid repellent layer 6 and the nozzle hole processing accuracy, aliphatic / aromatic copolymer hydrocarbon resins, hydrogenated petroleum resins, and terpene resins are preferable, and hydrogenated petroleum resins and terpene resins are more preferable.

[0056] The content of the tackifier resin is in the range of 23 parts by mass or more and 78 parts by mass or less, more preferably 25 parts by mass or more and 75 parts by mass or less, and still more preferably 30 parts by mass or more and 55 parts by mass or less, based on 100 parts by mass of the styrene-isoprene-styrene block copolymer. When the content of the tackifier resin is less than 23 parts by mass, the effect of adding the tackifier resin is insufficient, and the amount of the styrene-isoprene-styrene block copolymer in the pressure-sensitive adhesive layer 3 becomes too large, so that the elastic modulus in the vicinity of room temperature of the rubbery flat region of the pressure-sensitive adhesive layer 3 cannot be sufficiently reduced, and further, the elasticity of the pressure-sensitive adhesive layer 3 with respect to vibrations at a repetition frequency of several tens to several hundreds of Hz during laser processing cannot be sufficiently improved. In this case, since the temporary fixing force for the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate and the tack of the pressure-sensitive adhesive layer 3 are reduced, during a series of processing steps, the base material 5 for the nozzle plate may peel from the adhesive tape 1, and the base material 5 for the nozzle plate or its cut and separated pieces may be displaced during laser processing or cleaning. Further, peeling may occur at the interface between the pressure-sensitive adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a poor shape of the nozzle hole h. Further, since the base material 5 for the nozzle plate is likely to shake on the pressure-sensitive adhesive layer 3 during laser processing, the pressure-sensitive adhesive layer 3 is more likely to be deformed, making stable ablation processing difficult, and there is a risk that the shape of the nozzle hole h will deteriorate during nozzle hole processing by laser.

[0057] On the other hand, when the content of the tackifier resin exceeds 78 parts by mass, the content of the styrene-isoprene-styrene block copolymer in the pressure-sensitive adhesive layer 3 decreases, and the content ratio of the oligomeric tackifier resin increases, so that the tackifier resin begins to be unevenly distributed on the surface of the pressure-sensitive adhesive layer 3, and the cohesive force of the pressure-sensitive adhesive layer 3 decreases. In this case, there is a risk of clogging of the nozzle hole h during nozzle hole processing by laser. Further, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (adhesive remaining) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 and the edge portion of the nozzle hole h. This is the same as the above-described presumed reason, but in this case, since the cohesive force is reduced, the level of this defect is likely to be more prominent.

[0058] When the content of the tackifier resin is within the above range, after ensuring the temporary fixing force of the liquid-repellent layer of the inkjet head on the substrate for the nozzle plate on which the liquid-repellent layer is formed, stable ablation processing can be performed by a laser with a repetition frequency of several tens to several hundreds of Hz. As a result, it becomes possible to manufacture a high-quality nozzle plate with good processing accuracy of the nozzle holes with a high yield.

[0059] The above tackifier resin preferably has a softening point in the range of 80°C or higher and 135°C or lower, more preferably in the range of 90°C or higher and 125°C or lower, and still more preferably in the range of 96°C or higher and 120°C or lower. When the softening point of the tackifier resin is less than 80°C, there is a risk of clogging of the nozzle holes h when the addition amount of the tackifier resin is large. In addition, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (glue residue) on the surface of the liquid-repellent layer 6 of the nozzle plate 30 and the edge portion of the nozzle holes h. In this specification, the softening point of the tackifier resin means a value measured in accordance with JIS K 2531.

[0060] On the other hand, when the softening point of the tackifier resin exceeds 135°C, when the addition amount of the tackifier resin is large, the elastic modulus of the rubbery flat region of the adhesive layer 3 near room temperature tends to become excessively large. In this case, since the temporary fixing force on the liquid-repellent layer 6 formed on the substrate 5 for the nozzle plate and the tack of the adhesive layer 3 decrease, there is a risk that the substrate 5 for the nozzle plate peels off from the adhesive tape 1 during a series of processing steps, or that the substrate 5 for the nozzle plate and its cut and separated pieces are displaced during or after laser processing. In addition, peeling may occur at the interface between the adhesive layer 3 and the substrate 5 for the nozzle plate during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a deterioration of the shape of the nozzle holes h.

[0061] <Release liner 4> The release liner 4 is not particularly limited. For example, a film such as paper, polyethylene, polypropylene, or polyethylene terephthalate that has been subjected to a release treatment to enhance the releasability from the adhesive layer 3 can be used. Also, the thickness of the release liner 4 is not particularly limited, but it is usually in the range of 25 μm to 125 μm.

[0062] [Method for manufacturing the adhesive tape 1] Subsequently, the method for manufacturing the adhesive tape 1 of the present embodiment will be described. Note that the following description is an example, and the method for manufacturing the adhesive tape 1 is not limited to the following. To produce the adhesive tape 1, for example, an adhesive is applied and dried on the base material 2 to form the adhesive layer 3. Subsequently, the release-treated surface side of the release liner 4 is bonded onto the formed adhesive layer 3. Thereafter, by heating and curing as necessary, the adhesive tape 1 having the laminated structure shown in FIG. 1 can be obtained.

[0063] [Method for manufacturing the nozzle plate 30 of the inkjet head using the adhesive tape 1] FIG. 4 is a flowchart showing an example of the manufacturing process of the nozzle plate 30 using the adhesive tape 1 to which the present embodiment is applied. FIGS. 5(a) to (d) are perspective views showing the manufacturing steps (Part 1: corresponding to steps S1 to S4 in FIG. 4) in a typical method for manufacturing the nozzle plate 30 using the adhesive tape 1 to which the present embodiment is applied. FIGS. 6(a) and (b) are perspective views showing the manufacturing steps (Part 2: corresponding to steps S5 and S6 in FIG. 4) in a typical method for manufacturing the nozzle plate 30 using the adhesive tape 1 to which the present embodiment is applied.

[0064] As an example of the method for manufacturing the nozzle plate 30 of the inkjet head using the adhesive tape 1 to which the present embodiment is applied, steps S1 to S7 shown in FIG. 4 and the manufacturing steps shown in FIGS. 5 and 6 can be cited. The details thereof will be described below.

[0065] <Step S1> Step S1 shown in FIG. 4 and FIG. 5(a) are the preparation steps of the base material 5 for the nozzle plate, which is the base material of the nozzle plate 30. The base material 5 for the nozzle plate may be a single-sheet-like sheet or a roll-shaped raw material.

[0066] (Base material 5 for nozzle plate) As the material of the base material 5 for the nozzle plate, a resin sheet capable of ablation by laser light can be used. For example, resin sheets such as polycarbonate, polysulfone, polyimide, polyetherimide, polybenzimidazole, polyacetal, polyethylene, polyethylene terephthalate, polyethylene naphthalate, polyether ketone, polyether sulfone, polystyrene, polyamide, polyphenylene oxide, polyphenylene sulfide, cellulose acetate, phenol resin, acrylic resin, and liquid crystal polymer can be preferably used. Among these, from the viewpoints of versatility, heat resistance, chemical stability, etc., resin sheets made of polyimide, polyphenylene sulfide, and polyethylene terephthalate are preferable.

[0067] The thickness of the base material 5 for the nozzle plate is not particularly limited, but is usually in the range of 10 μm or more and 200 μm or less, preferably in the range of 10 μm or more and 150 μm or less, and more preferably in the range of 20 μm or more and 100 μm or less. When the above thickness is less than 10 μm, the strength of the nozzle plate 30 may decrease. On the other hand, when the above thickness exceeds 200 μm, the processing time using a laser for forming the nozzle holes h becomes long, so there is a possibility of reducing the production efficiency.

[0068] Also, the surface of the base material 5 for the nozzle plate may be subjected to a roughening treatment such as oxygen plasma treatment or sandblasting treatment as necessary for the purpose of improving the adhesion with the liquid-repellent layer 6 described later.

[0069] <Step S2> Step S2 shown in FIG. 4 and FIG. 5(b) is a step of forming a liquid repellent layer 6 on one side (the side where ink is ejected) of a sheet-like base material 5 for a nozzle plate from which a plurality of nozzle plates 30 can be produced. Thereby, ink repellency is imparted to the surface of the base material 5 for the nozzle plate.

[0070] (Liquid repellent layer 6) From the viewpoint of imparting the above ink repellency, the liquid repellent layer 6 formed on one side (the side where ink is ejected) of the base material 5 for the nozzle plate preferably has a contact angle of distilled water on the surface of the liquid repellent layer 6 of 110° or more and 180° or less, more preferably 115° or more and 180° or less, and even more preferably 120° or more and 180° or less. When the surface of the liquid repellent layer 6 is smooth, the upper limit value of the contact angle of the distilled water may be, for example, 140°. The contact angle of the distilled water is measured by the following method. That is, in an environment with a measurement atmosphere of 23°C and 50% RH, using a contact angle meter (manufactured by Jasco International Co., Ltd. (First Ten Angstroms, USA), product name "FTA1000 type", control / analysis software "FTA32"), measurement is performed by the droplet method. The dropping amount of distilled water on the surface of the liquid repellent layer 6 formed on one side of the base material 5 for the nozzle plate is 3 μL, and the contact angle is calculated by the Θ / 2 method from the image 10 seconds after dropping (performed with N = 5, and the average value is calculated).

[0071] The material for forming the liquid repellent layer 6 is not particularly limited, and examples thereof include fluorine-based compounds. The fluorine-based compound is preferably (1) "a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoroalkyl group", (2) "a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoropolyether group", (3) "a mixture containing a compound having a perfluoroalkyl group, or (4) a mixture containing a compound having a perfluoropolyether group".

[0072] As the fluorine-based compound, commercially available products can also be used. Specifically, as the compound having an alkoxysilyl group-terminated perfluoropolyether group, for example, "Optool DSX (trade name)" manufactured by Daikin Industries, Ltd., and as the compound having an alkoxysilyl group-terminated fluoroalkyl group, for example, "Fluorosurf FG-5010Z130-0.2 (trade name)" manufactured by Fluoro Technology Co., Ltd. can be mentioned. Further, as the polymer having a perfluoroalkyl group, for example, "EFF Coat (trade name) series" manufactured by AGC Seimi Chemical Co., Ltd., and as the polymer having a fluorine-containing heterocyclic structure in the main chain, for example, "Cytop CTX-105 (trade name)", "Cytop CTX-805 (trade name)" manufactured by AGC Inc. can be mentioned. Also, a mixture of a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) dispersion and a polyamideimide resin can be mentioned.

[0073] As other materials for forming the liquid-repellent layer 6, fluororesins can also be applied. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), etc. can be used. Also, for example, a hydrolyzable silane compound containing a fluorine group described in JP-A-2017-154055, an organic fluorine compound described in WO2008 / 120505, a fluorine-containing organometallic compound, etc. can also be used.

[0074] The method for forming the liquid-repellent layer 6 on one side (the side where the ink is ejected) of the base material 5 for the nozzle plate is not particularly limited, but a thin film forming method such as a wet method or a dry method can be appropriately selected according to the characteristics of the material used for forming the liquid-repellent layer 6.

[0075] As a method for forming the liquid-repellent layer 6 by a wet method, for example, a method of coating a solution of a material containing the above fluorine-based compound, a method of coating a dispersion of a material containing the fluorine-containing compound and then performing a heat melting treatment, etc. can be mentioned. Specific wet methods include a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, an inkjet printing method, etc. When forming the liquid-repellent layer 6 by such a wet method, the thickness of the liquid-repellent layer 6 is preferably in the range of 5 nm or more and 5 μm or less.

[0076] Also, as a method for forming the liquid-repellent layer 6 by a dry method, 1) physical vapor deposition (PVD) methods, such as a resistance heating type vacuum evaporation method, an electron beam heating type vacuum evaporation method, an ion plating method, an ion beam assist vacuum evaporation method, a sputtering method, etc., 2) chemical vapor deposition (CVD) methods, such as plasma CVD, thermal CVD, metalorganic CVD, photo CVD, etc. can be mentioned. When forming the liquid-repellent layer 6 by such a dry method, the thickness of the liquid-repellent layer 6 is preferably in the range of 1 nm or more and 500 nm or less.

[0077] The thickness of the liquid-repellent layer 6 is generally preferably in the range of 1 nm or more and 5 μm or less as described above, but from the viewpoint of the processing accuracy of the nozzle holes by laser processing, it is more preferably in the range of 1 nm or more and 300 nm or less, and particularly preferably in the range of 1 nm or more and 30 nm or less.

[0078] Also, when forming the liquid-repellent layer 6, if necessary, after forming a film of the material for forming the liquid-repellent layer 6 on the surface of the base material 5 for the nozzle plate by a wet method or a dry method, the excess material is removed, and solvent washing may be performed to form a uniform liquid-repellent layer 6 without film unevenness. Here, examples of the solvent to be used include solvents that can dilute the material for forming the liquid-repellent layer 6. Specifically, for example, fluorine-based solvents such as chlorofluorocarbon and perfluorohexane, methanol, ethanol, ethyl acetate, benzene, etc. may be mentioned. Note that it is desirable to further wash with pure water after the solvent washing.

[0079] The liquid-repellent layer 6 may be heat-treated after the solvent washing or after the water washing, if necessary, to improve the durability and chemical resistance of the liquid-repellent layer 6. When performing the heat treatment, for example, it may be performed at 50°C to 200°C for about 1 hour to 2 hours using an oven or a hot plate. Note that if the heat treatment is not performed, for example, it may be left in a normal temperature and atmospheric atmosphere for about 1 day.

[0080] In the nozzle plate 30 according to the present invention, in addition to the base material 5 for the nozzle plate and the liquid-repellent layer 6, various constituent layers such as an underlayer and a conductive layer can be provided as necessary. Further, an adhesion layer can also be provided between the base material 5 for the nozzle plate and the underlayer or the conductive layer.

[0081] (Underlayer) The nozzle plate 30 according to the present invention can be provided with an underlayer between the base material 5 for the nozzle plate and the liquid-repellent layer 6 for the purpose of improving the adhesion.

[0082] As the underlayer, for example, (1) a compound containing one or more kinds of metal elements selected from tantalum, zirconium, hafnium, niobium, titanium, tungsten, cobalt, molybdenum, vanadium, lanthanum, manganese, chromium, yttrium, praseodymium, ruthenium, rhodium, rhenium, iridium, cerium, and aluminum, and containing one or more kinds of elements selected from oxygen, nitrogen, and carbon; (2) a compound selected from silicon oxide, silicon carbide oxide, tantalum silicate, and silicon carbon oxide; (3) a polyamide resin or an isocyanate compound; and (4) a polysilazane or a silane coupling agent, etc. may be mentioned.

[0083] The method for forming the underlayer is not particularly limited, and examples thereof include a chemical vapor deposition method, a physical vapor deposition method, and a coating method using a solution material containing silicon (such as polysilazane, silane coupling agent, etc.). Further, these methods may be used in appropriate combination.

[0084] The thickness of the underlayer is preferably in the range of 0.5 nm or more and 1 μm, and more preferably in the range of 1 nm or more and 50 nm from the viewpoint of the processing accuracy of the nozzle holes by laser processing.

[0085] (Conductive layer) In the nozzle plate 30 according to the present invention, a conductive layer can be provided at an arbitrary position between the base material 5 for the nozzle plate and the liquid repellent layer 6 for the purpose of preventing the adhesion of ink droplets to the nozzle surface due to charging during ink injection.

[0086] The sheet resistance value of the above conductive layer measured by the double ring method conforming to JIS K 6911, ASTM D257 is preferably 1.0×10 10 Ω / sq. or less, more preferably 5.0×10 8 Ω / sq. or less, and still more preferably 3.0×10 4 Ω / sq. or less (however, excluding 0).

[0087] The conductive layer is preferably formed of a sublimable compound, and examples of the sublimable compound include a conductive carbon material or a metal compound.

[0088] Specific examples of the carbon material include, for example, fullerenes (fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C84, fullerene C240, fullerene C540, mixed fullerenes, fullerene nanotubes, multi-walled nanotubes, single-walled nanotubes, nano-horns (conical), etc.), graphene, carbon nanotubes, amorphous carbon (glass-like carbon, amorphous carbon containing at least one element of i, O, H, diamond-like carbon, hydrogen-free diamond-like carbon), etc.

[0089] Also, as the metal compound, a metal oxide can be preferably used. Specifically, for example, ITO (tin-doped indium oxide), ZnO, Nb 2 O 5 , ZnO / Sb 2 O 5 (zinc antimonate), ZrO 2 , CeO 2 , Ta 2 O 5 , TiO 2 , Ti 3 O 5 , Ti 4 O 7 , Ti 2 O 3 , TiO, SnO 2 , La 2 Ti 2 O 7 , IZO (indium-zinc oxide), AZO (aluminum-doped zinc oxide), GZO (gallium-doped zinc oxide), ATO (antimony-tin oxide), ICO (indium-cerium oxide), Bi 2 O 3 , Ga 2 O 3 , GeO 2 , SiO 2 , Al 2 O 3 , HfO 2, SiO, MgO, Y 2 O 3 , WO 3 , a-GIO (amorphous gallium indium oxide), IGZO (indium gallium zinc oxide), etc. can be mentioned.

[0090] As a method for forming the conductive layer using the above carbon material or metal compound, it is not particularly limited. For example, a method of forming the above carbon material or metal compound as a conductive layer by a vapor deposition method, or a method of forming it as a conductive layer by a coating method using a dispersion in which these materials are dispersed in a resin solution in a particulate state, etc. can be mentioned.

[0091] Also, the above conductive layer may be formed of an organic conductive polymer.

[0092] As the organic conductive polymer, it may be a material that itself functions as a binder and forms a conductive resin layer, or a method of forming conductive resin fine particles with a conductive polymer compound and adding it in a dispersed state (resin emulsion) to an existing resin material to form a conductive resin layer.

[0093] Specific examples of the organic conductive polymer include, for example, chain conductive polymers such as polypyrroles, polyindoles, polycarbazoles, polythiophenes, polyanilines, polyacetylenes, polyfurans, polyparaphenylenevinylenes, polyazulenes, polyparaphenylenes, polyparaphenylenesulfides, polyisothianaphthenes, polythiazyls, etc., and polyacene-based conductive polymers. Among these, at least one cationic π-conjugated conductive polymer selected from polythiophenes, polyanilines, and polypyrroles is preferable.

[0094] As a method for forming a conductive layer using the above organic conductive polymer, for example, a method of forming a conductive layer by a coating method using a solution in which the organic conductive polymer is dissolved in water or an organic solvent or a finely dispersed dispersion, a method of forming a conductive layer by an organic molecular beam deposition method in which a monomer is polymerized on the surface of a substrate to obtain an organic conductive polymer thin film, etc. can be mentioned.

[0095] The thickness of the conductive layer is preferably in the range of 1 nm or more and 3 μm or less, and more preferably in the range of 5 nm or more and 500 nm or less from the viewpoint of the processing accuracy of the nozzle holes by laser processing.

[0096] (Adhesion layer) In the nozzle plate 30 according to the present invention, an adhesion layer can also be provided between the substrate 5 for the nozzle plate and the conductive layer or the underlayer.

[0097] Specifically, as the adhesion layer, for example, it is preferably made of at least one oxide selected from the group consisting of tantalum, zirconium, hafnium, titanium, ruthenium, rhodium, rhenium, iridium, aluminum, silicon, and carbon. It may be an oxide of one of these elements such as silicon oxide, or an oxide in which two or more of these elements are bonded such as tantalum silicate.

[0098] As a method for forming the adhesion layer, the same method as the method for forming the above-described underlayer can be used.

[0099] The thickness of the adhesion layer is preferably in the range of 0.5 nm or more and 1 μm or less, and more preferably in the range of 1 nm or more and 50 nm or less from the viewpoint of the processing accuracy of the nozzle holes by laser processing.

[0100] <Step S3> Step S3 shown in FIG. 4 and FIG. 5(c) are steps of preparing the adhesive tape 1 to be bonded in step S4 of the next process in order to protect the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate. The adhesive tape 1 may be prepared as a single-sheet form or a roll-shaped raw material according to the form of the base material 5 for the nozzle plate.

[0101] (Adhesive tape 1) As described above, the adhesive tape 1 includes a base material 2 and an adhesive layer 3 laminated on one surface of the base material 2. The adhesive layer 3 includes A) a styrene-isoprene-styrene block copolymer, B) a process oil composed of a petroleum-based hydrocarbon, and C) an adhesion-imparting resin containing at least one selected from the group consisting of an aliphatic hydrocarbon resin, an aliphatic / aromatic copolymer hydrocarbon resin, a hydrogenated petroleum resin, and a terpene resin. The adhesion-imparting resin is composed of an adhesive composition containing the adhesion-imparting resin in a range of 23 parts by mass or more and 78 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer. And further, the adhesive layer 3 has a storage elastic modulus (G') at 23°C when measuring the dynamic viscoelasticity under the conditions of a frequency of 100 Hz and a heating rate of 2°C / min in a shear mode. 100Hz is 3.0×10 5 Pa or more and 6.5×10 5 Pa or less.

[0102] As the laser in the laser processing of step S6 described later, an excimer laser with a repetition frequency usually set to about several tens to several hundreds of Hz is preferably used. The adhesive tape 1 of the present embodiment has a storage elastic modulus (G') at 23°C when measuring the dynamic viscoelasticity under the conditions of a frequency of 100 Hz and a heating rate of 2°C / min. 100Hz is 3.0×10 5 Pa or more and 6.5×10 5Since the pressure-sensitive adhesive layer 3 has a range of less than Pa, according to the pressure-sensitive adhesive tape 1, when laser processing with a repetition frequency set to about several tens to several hundreds of Hz is performed on the nozzle plate base material 5 on which the liquid-repellent layer 6 is formed, the pressure-sensitive adhesive layer 3 can exhibit an appropriate hardness (storage elastic modulus) with respect to the vibration of the repetition frequency. As a result, the nozzle plate base material 5 provided with the liquid-repellent layer 6 on the pressure-sensitive adhesive layer 3 can be favorably cut and separated, and nozzle holes h with better processing accuracy than before can be formed, so that the nozzle plate 30 can be manufactured with good yield.

[0103] The adhesive force of the adhesive tape 1 with respect to the liquid-repellent layer 6 formed on the nozzle plate base material 5 is preferably in the range of 0.030 N / 10 mm or more and 0.160 N / 10 mm or less, and more preferably in the range of 0.050 N / 10 mm or more and 0.130 N / 10 mm or less. When the adhesive force is less than 0.030 N / 10 mm, during a series of processing steps, the liquid-repellent layer 6 may peel off from the adhesive tape 1, and the nozzle plate base material 5 or its cut and separated pieces may be displaced during laser processing or cleaning. Also, peeling may occur at the interface between the pressure-sensitive adhesive layer 3 and the nozzle plate base material 5 during nozzle hole processing by laser, and stable ablation processing may not be possible, resulting in a poor shape of the nozzle hole h. On the other hand, when the adhesive force exceeds 0.160 N / 10 mm, when the nozzle plate 30 is peeled off from the adhesive tape 1 after a predetermined laser processing is completed, the nozzle plate 30 may be deformed (dimensional distortion). The adhesive force is the adhesive force when peeled off at a speed of 5 mm / second in the 90° direction with respect to the liquid-repellent layer 6 formed on the nozzle plate base material 5.

[0104] The adhesive tape 1 preferably has a tack of the adhesive layer 3 measured using a ball transfer device provided with an inclined plate having an inclination angle of 30° in the range of 6 or more and 14 or less, more preferably in the range of 7 or more and 12 or less. When the tack is less than 6, during a series of processing steps, the liquid repellent layer 6 may peel off from the adhesive tape 1, or the base material 5 for the nozzle plate may be displaced during laser processing or cleaning. Also, peeling may occur at the interface between the adhesive layer 3 and the base material 5 for the nozzle plate during nozzle hole processing by laser, and there is a risk that stable ablation processing cannot be performed and the shape of the nozzle hole h may deteriorate. On the other hand, when the tack exceeds 14, especially if the hardness of the adhesive layer 3 becomes excessively low, there is a risk that the shape of the nozzle hole h may deteriorate or clogging of the nozzle hole h may occur during nozzle hole processing by laser. Also, when the adhesive tape 1 is peeled off, there is a risk of contamination due to adhesive residue (glue residue) on the surface of the liquid repellent layer 6 of the nozzle plate 30 or at the edge portion of the nozzle hole h. Further, when the nozzle plate 30 is peeled off from the adhesive tape 1 after a predetermined laser processing is completed, there is a risk of dimensional distortion occurring in the nozzle plate 30.

[0105] The total thickness of the adhesive tape 1 is preferably in the range of 15 μm or more and 1100 μm or less, more preferably in the range of 30 μm or more and 550 μm or less, and particularly preferably in the range of 60 μm or more and 350 μm or less from the viewpoints of handleability, productivity, and processing accuracy by laser.

[0106] <Step S4> Step S4 shown in FIG. 4 and FIG. 5(d) is a step of obtaining a laminate 20 by bonding the adhesive tape 1 from which the release liner 4 has been peeled to the liquid repellent layer 6 formed on the base material 5 for the nozzle plate so that the adhesive layer 3 and the liquid repellent layer 6 face each other. In addition to the purpose of protecting the liquid repellent layer 6 as described above, this step aims to temporarily fix the cut pieces of each nozzle plate size so that they do not separate when performing outer shape processing to a predetermined nozzle plate size by laser in step S5 of the next step.

[0107] When bonding the adhesive tape 1 from which the release liner 4 has been removed so that the adhesive layer 3 and the liquid repellent layer 6 face each other, it is preferable to perform pressure bonding at room temperature from the viewpoint of workability. However, if necessary, heat pressure bonding may be performed. The heating temperature condition is preferably in the range of 40°C or higher and 150°C or lower. Also, the pressure condition is preferably in the range of 0.3 MPa or higher and 5 MPa or lower in any case.

[0108] <Step S5> Step S5 shown in FIG. 4 is an external shape processing step using a laser for cutting and dividing the base material 5 for the nozzle plate provided with the liquid repellent layer 6 into a nozzle plate 30 of a desired size to be mounted on the inkjet head on the adhesive tape 1 (the laminated portion of the base material 5 for the nozzle plate and the liquid repellent layer 6: at this stage, the nozzle holes h are not formed).

[0109] Specifically, as shown in FIG. 6(a), from the side of the base material 5 for the nozzle plate of the laminate 20, by performing scan processing with the laser beam L using the laser oscillator 7, external shape processing is performed along the external shape processing line 8 to the size of the predetermined nozzle plate 30. When performing scan processing with the laser beam L, the base material 5 for the nozzle plate, the liquid repellent layer 6, and the adhesive layer 3 of the adhesive tape 1 are penetrated (cut), but external shape processing is performed to such an extent that the base material 2 of the adhesive tape 1 is not penetrated (cut).

[0110] As a method for processing the external shape of the laminate 20 (the base material 5 for the nozzle plate provided with the liquid repellent layer 6), a method using a laser for the external shape processing is preferable, and the laser is preferably a pulse oscillation type laser (pulse laser) or a continuous oscillation type laser (CW laser).

[0111] Specific examples of the laser beam L generated by the laser oscillator 7 include gas lasers such as Ar laser, Kr laser, and excimer laser, single crystal YAG, YVO 4 , forsterite (Mg 2 SiO 4 ), YAlO 3 , GdVO 4or polycrystalline (ceramic) YAG, Y2O 3 YVO 4 YAlO 3 GdVO 4 Lasers oscillated from one or more of a laser using, as a medium, a material in which one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta are added as dopants to YAG, Y2O, YVO, YAlO, GdVO, a glass laser, a ruby laser, an alexandrite laser, a Ti:sapphire laser, a copper vapor laser, or a gold vapor laser.

[0112] Among these, as the laser light L, for example, solid laser light such as YAG-UV (yttrium aluminum garnet crystal: wavelength 266 nm) or YVO4 (wavelength: 355 nm), or excimer laser light such as ArF (wavelength 193 nm), KrF (248 nm), XeCl (wavelength 308 nm), or XeF (wavelength 351 nm) is preferably mentioned.

[0113] After performing external shape processing using a laser, in order to remove the decomposition residue deposits generated during laser cutting, it is preferable to clean the surface of the laminate 20. The cleaning method is not particularly limited, and examples include spraying (ejection) treatment with pure water, a solvent, and air, immersion treatment in pure water or a solvent, and a removal method using ultrasonic vibration.

[0114] <Step S6> Step S6 shown in FIG. 4 is a step of forming nozzle holes h in the nozzle plate 30 (the laminated portion of the nozzle plate base material 5 and the liquid repellent layer 6). In the present embodiment, the nozzle holes h are preferably formed by a laser processing method, more preferably an excimer laser is used as the laser for the laser processing method, and it is particularly preferable to form the nozzle holes h by a reduction transfer method of the mask pattern 12.

[0115] (Mask formation by reduction transfer method) An example of mask formation by the reduction transfer method is shown in FIG. 6(b).

[0116] With respect to the nozzle plate 30 (the laminated portion of the nozzle plate base material 5 and the liquid repellent layer 6) on the adhesive tape 1 that has been subjected to external shape processing by the steps up to step S5, nozzle holes h are formed by drilling through holes as shown in FIG. 3. The nozzle holes h are formed in the nozzle plate 30 by appropriately selecting the pitch and number thereof in accordance with the pitch of the ink flow paths of the member to which the nozzle plate 30 is joined.

[0117] As shown in FIG. 6(b), a laser oscillator 9, a homogenizer optical system 10 including a plurality of lenses for making uniform the amount of laser light L for drilling the nozzle holes h emitted from the laser oscillator 9, and a photomask 11 for masking the laser light L that has passed through the homogenizer optical system 10 are arranged. The homogenizer optical system 10 is composed of a cylindrical lens, a condenser lens, and the like. The photomask 11 is provided with a nozzle-shaped mask pattern 12 for forming the nozzle holes h in the nozzle plate 30 at a predetermined interval. The laser light L that has passed through the photomask 11 via the mask pattern 12 is reflected by a reflection mirror M and then reduced and transferred onto the nozzle plate 30 (the laminated portion of the nozzle plate base material 5 and the liquid repellent layer 6) by an objective lens 13 to perform pattern processing of the nozzle holes h.

[0118] As the laser light L generated by the laser oscillator 9, for example, excimer laser light or the like can be preferably exemplified. This is because excimer laser light has a short wavelength and enables preferable microfabrication. The wavelength of the excimer laser light is in the range of 190 nm or more and 355 nm or less. Specifically, for example, ArF (wavelength 193 nm), KrF (248 nm), XeCl (wavelength 308 nm), XeF (wavelength 351 nm), etc. can be preferably mentioned. The pulse repetition frequency of the excimer laser light is preferably set in the range of several tens to several hundreds of Hz.

[0119] The photomask 12 is composed of a substrate that transmits the laser beam L and a pattern film provided on the surface of the substrate. The pattern film has a predetermined mask pattern formed thereon that blocks the laser beam L. The substrate is made of synthetic quartz, quartz, or the like. Further, the pattern film is made of, for example, a chromium film, a dielectric multilayer film, or the like.

[0120] <Step S7> According to the above method, by finally peeling off the adhesive tape 1 from the surface of the liquid repellent layer 6 of the nozzle plate 30 that has been externally shaped and nozzle hole processed by laser on the adhesive tape 1, a nozzle plate 30 having a plurality of nozzle holes h formed therein is obtained (see FIG. 3). According to the adhesive tape 1 of the present embodiment, it is possible to manufacture a nozzle plate 30 having a high processing accuracy on the nozzle side on the laser beam irradiation side and the nozzle outlet side, and having nozzle holes h with a stable shape, with a good yield.

[0121] [Inkjet head 100 to which nozzle plate 30 is applied] FIG. 7 is an exploded perspective view showing an example of the inkjet head 100. The manufactured nozzle plate 30 has its surface on the ink flow path side (the side opposite to the liquid repellent layer 6) joined to the front end surface 42 of an ink flow path member 40 in which a plurality of ink chambers 41 corresponding to the nozzle holes h are formed, via a thermosetting adhesive such as a thermosetting epoxy adhesive or a room temperature curing adhesive such as a two-component mixed epoxy adhesive, thereby manufacturing the inkjet head 100. According to the inkjet head 100 to which the nozzle plate 30 manufactured using the adhesive tape 1 of the present embodiment is applied, since the processing accuracy on the ink flow path side and the ink ejection side (nozzle outlet side) of the nozzle plate 30 is high and nozzle holes h with a stable shape are formed, the landing accuracy of the ejected ink droplets is high, and it is possible to record high-quality images.

[0122] As the ink flow path member 40, here an example is shown in which the volume inside the ink chamber 41 is changed by shear-deforming the side wall of the ink chamber 41, and the ink inside the ink chamber 41 is ejected as ink droplets from the nozzle holes h by the pressure generated at that time. However, any structure may be used as long as the ink inside the ink chamber 41 can be ejected as ink droplets from the nozzle holes h.

[0123] As described above, an example of the manufacturing method of the nozzle plate 30 using the adhesive tape 1 of the present embodiment and the application of the nozzle plate 30 to the inkjet head has been shown, but it is not particularly limited thereto. For example, as another aspect in the case of performing external shape processing by scanning with a laser beam L, the aspect disclosed in Japanese Patent Application Laid-Open No. 2001-315339 can also be applied. That is, first, as shown in FIG. 2, after the adhesive tape 1 is bonded to the nozzle plate base material 5 provided with the liquid repellent layer 6, a second adhesive tape is further bonded onto the base material 2 of the adhesive tape 1, and cutting to the nozzle plate size by the laser beam L is completely performed from the nozzle plate base material 5 side in the depth direction up to the nozzle plate base material 5, the liquid repellent layer 6, and the adhesive tape 1, and an aspect in which the second adhesive tape is partially cut and left may be applied. Thereafter, the nozzle holes of the nozzle plate 30 are processed by irradiating with the laser beam L. After the above processing is completed, only the second adhesive tape is peeled off to obtain the nozzle plate 30 with the adhesive tape 1 bonded thereto. The nozzle plate 30 is bonded to the front end face 42 of the ink flow path member 40 via an adhesive in a state where the adhesive tape 1 is bonded, and finally the adhesive tape 1 is peeled off from the surface of the liquid repellent layer 6 of the nozzle plate 30. Here, the second adhesive tape may be the same as the adhesive tape 1, but it is preferably an ultraviolet irradiation peelable adhesive tape provided with an adhesive layer whose adhesive force decreases by ultraviolet irradiation or the like on a base material such as polyethylene terephthalate. When peeling the second adhesive tape, by irradiating the second adhesive tape with ultraviolet rays or the like, the adhesive force of the adhesive layer decreases, and after performing the nozzle hole processing, only the second adhesive tape can be easily peeled off, improving workability.

Example

[0124] Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to the following examples.

[0125] 1. Preparation of Adhesive Tape 1 and Laminate 20 <Example 1> (Preparation of Adhesive Tape 1) To 100 parts by mass of a styrene-isoprene-styrene block copolymer (trade name: Qintac3450, styrene content: 19% by mass, SI diblock content: 30% by mass, polymer structure: radial type) manufactured by Nippon Zeon Co., Ltd., 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115 °C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 0.67 parts by mass of an antioxidant (trade name: Irganox1010, hindered phenolic antioxidant) manufactured by BASF Japan Ltd., and 6 parts by mass of a process oil (trade name: Diana Process Oil NS-90S, petroleum hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. were mixed, and then diluted with toluene so that the non-volatile content was 50% by mass, and stirred at room temperature for 48 hours or more to obtain an adhesive solution.

[0126] Subsequently, the obtained adhesive solution was applied onto a polyester film "#125-S10" (trade name, thickness: 125 μm) manufactured by Toray Industries, Inc. using a comma coater so that the dry thickness of the adhesive layer was 40 μm, and dried at about 110 °C for 3 minutes to form an adhesive layer. On the adhesive layer formed on this polyester film, the release-treated surface side of a release liner "NS-38-FXA" (trade name, thickness: 38 μm, polyester film) manufactured by Nakamoto Pax Co., Ltd. was laminated to produce Adhesive Tape 1.

[0127] (Formation of Liquid Repellent Layer 6 on Substrate 5 for Nozzle Plate and Preparation of Laminate 20) Next, as the base material 5 for the nozzle plate, a polyimide sheet "Upilex" (trade name, thickness: 75 μm) manufactured by Ube Industries, Ltd. was prepared. The size of the base material 5 for the nozzle plate was 220 mm in length and 150 mm in width. A conductive layer with a layer thickness of 20 nm composed of amorphous carbon was formed on the prepared polyimide sheet by sputtering using a carbon target. Further, adjacent to the formed conductive layer, as an underlayer forming material, a film-forming gas containing an alkyl silicon compound (abbreviation: TMS, tetramethylsilane, Si(CH 3 ) 4 ) and carbon dioxide as an additive gas and argon as an inert gas were used, and vapor deposition was performed by a known plasma CVD method to form an underlayer with a layer thickness of 5 nm composed of silicon carbide oxide.

[0128] Next, as the coating solution A for forming the liquid-repellent layer, an alkoxysilyl group-terminated perfluoropolyether compound "Optool DSX-E" (trade name) manufactured by Daikin Industries, Ltd. was prepared. Using the above coating solution A, adjacent to the formed underlayer, a liquid-repellent layer 6 with a layer thickness of 5 nm was formed by spray coating. When the contact angle of distilled water was measured on the surface of the obtained liquid-repellent layer 6 by the above droplet method, it was 120°.

[0129] Subsequently, the release liner of the adhesive tape 1 cut to the same size as the base material 5 for the nozzle plate was peeled off from the adhesive layer, and while pressing at a pressure of 0.5 MPa so that the exposed adhesive layer and the liquid-repellent layer of the polyimide sheet on which the liquid-repellent layer was formed faced each other, they were bonded together to produce a laminate 20 having the configuration shown in FIGS. 2 and 5(d).

[0130] <Example 2> In the preparation of the adhesive solution of the adhesive tape 1, the adhesive tape 1 was produced in the same manner as in Example 1 except that the blending amount of the tackifying resin (trade name: YS resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 30 parts by mass, and then the laminate 20 was obtained.

[0131] <Example 3> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amount of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 70 parts by mass, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0132] <Example 4> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, the compounding amount of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 25 parts by mass, and the compounding amount of the process oil (trade name: Diana Process Oil NS-90S, petroleum hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. was changed to 8 parts by mass. Except for this, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0133] <Example 5> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amount of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 75 parts by mass, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0134] <Example 6> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 50 parts by mass of the tackifier resin (trade name: Alcon P-115, softening point: 115 ° C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was used instead of 50 parts by mass of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0135] <Example 7> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amount of the tackifier resin (trade name: Alcon P-115, softening point: 115 ° C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was changed to 30 parts by mass, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 6, and then the laminate 20 was obtained.

[0136] <Example 8> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amount of the tackifier resin (trade name: Alcon P-115, softening point: 115 ° C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was changed to 75 parts by mass, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 6, and then the laminate 20 was obtained.

[0137] <Example 9> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 50 parts by mass of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was replaced with 50 parts by mass of the tackifier resin (trade name: Quintone CX495, softening point: 96 ° C, aliphatic hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0138] <Example 10> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 50 parts by mass of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was replaced with 50 parts by mass of the tackifier resin (trade name: Quintone G115, softening point: 115 ° C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0139] <Example 11> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 50 parts by mass of the tackifier resin (trade name: YS Resin PX1150, softening point: 115 ° C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was replaced with 50 parts by mass of the tackifier resin (trade name: Quintone N180, softening point: 80 ° C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0140] <Example 12> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 100 parts by mass of a styrene-isoprene-styrene block copolymer (trade name: Qintac3450, styrene content: 19% by mass, SI diblock content: 30% by mass, polymer structure: radial type) manufactured by Nippon Zeon Co., Ltd. was replaced with 100 parts by mass of a styrene-isoprene-styrene block copolymer (trade name: Qintac3421, styrene content: 14% by mass, SI diblock content: 26% by mass, polymer structure: linear type) manufactured by Nippon Zeon Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0141] <Example 13> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was replaced with 50 parts by mass of a tackifier resin (trade name: YS Resin PX1250, softening point: 125°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0142] <Example 14> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 100 parts by mass of a styrene-isoprene-styrene block copolymer (trade name: Qintac3450, styrene content: 19% by mass, SI diblock content: 30% by mass, polymer structure: radial type) manufactured by Nippon Zeon Co., Ltd. was replaced with 50 parts by mass of a styrene-isoprene-styrene block copolymer (trade name: Qintac3520, styrene content: 15% by mass, SI diblock content: 78% by mass, polymer structure: linear type) manufactured by Nippon Zeon Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0143] <Example 15> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1 except that the blending amount of the process oil (trade name: Diana Process Oil NS-90S, petroleum-based hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. was changed to 3 parts by mass, and then the laminate 20 was obtained.

[0144] <Example 16> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1 except that the blending amount of the process oil (trade name: Diana Process Oil NS-90S, petroleum-based hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. was changed to 18 parts by mass, and then the laminate 20 was obtained.

[0145] <Example 17> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, instead of 50 parts by mass of the tackifier resin (trade name: Alcon P-115, softening point: 115°C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd., The pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 5 except that 50 parts by mass of the tackifier resin (trade name: Alcon M-135, softening point: 135°C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was used, and then the laminate 20 was obtained.

[0146] <Comparative Example 1> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1 except that the blending amount of the tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 20 parts by mass, and then the laminate 20 was obtained.

[0147] <Comparative Example 2> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1 except that the blending amount of the tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd. was changed to 80 parts by mass, and then the laminate 20 was obtained.

[0148] <Comparative Example 3> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 20 parts by mass of a tackifier resin (trade name: Alcon P-115, softening point: 115°C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was used instead of 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0149] <Comparative Example 4> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 80 parts by mass of a tackifier resin (trade name: Alcon P-115, softening point: 115°C, hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd. was used instead of 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0150] <Comparative Example 5> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 20 parts by mass of a tackifier resin (trade name: Quintone N180, softening point: 80°C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. was used instead of 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0151] <Comparative Example 6> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that 80 parts by mass of a tackifier resin (trade name: Quintone N180, softening point: 80°C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. was used instead of 50 parts by mass of a tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0152] <Comparative Example 7> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, instead of 50 parts by mass of the tackifier resin (trade name: YS Resin PX1150, softening point: 115°C, terpene resin) manufactured by Yasuhara Chemical Co., Ltd., 100 parts by mass of the tackifier resin (trade name: Quintone N180, softening point: 80°C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. and 80 parts by mass of the tackifier resin (trade name: Quintone CX495, softening point: 96°C, aliphatic hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. were used. The pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1 except that no process oil was used, and then the laminate 20 was obtained.

[0153] <Comparative Example 8> To 100 parts by mass of the styrene-isoprene-styrene block copolymer (trade name: Qintac 3520, styrene content: 15% by mass, SI diblock content: 78% by mass, polymer structure: linear type) manufactured by Nippon Zeon Co., Ltd. for the pressure-sensitive adhesive tape 1, 100 parts by mass of the tackifier resin (trade name: Quintone N180, softening point: 80°C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd., 80 parts by mass of the tackifier resin (trade name: Quintone CX495, softening point: 96°C, aliphatic hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd., 0.67 part by mass of the antioxidant (trade name: Irganox 1010, hindered phenol antioxidant) manufactured by BASF Japan Ltd., and 40 parts by mass of the process oil (trade name: Diana Process Oil NS-90S, petroleum hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. were mixed, and then diluted with toluene so that the non-volatile content became 50%, and stirred at room temperature for 48 hours or more to obtain a pressure-sensitive adhesive solution. Subsequently, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Example 1, and then the laminate 20 was obtained.

[0154] <Comparative Example 9> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amounts of the tackifier resin (trade name: Quintone CX495, softening point: 96 ° C, aliphatic hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. and the process oil (trade name: Diana Process Oil NS-90S, petroleum hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. were changed to 40 parts by mass and 10 parts by mass, respectively, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Comparative Example 8, and then the laminate 20 was obtained.

[0155] <Comparative Example 10> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the tackifier resin (trade name: Quintone CX495, softening point: 96 ° C, aliphatic hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. was not used, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Comparative Example 9, and then the laminate 20 was obtained.

[0156] <Comparative Example 11> In the preparation of the pressure-sensitive adhesive solution of the pressure-sensitive adhesive tape 1, except that the compounding amounts of the tackifier resin (trade name: Quintone N180, softening point: 80 ° C, aliphatic / aromatic copolymer hydrocarbon resin) manufactured by Nippon Zeon Co., Ltd. and the process oil (trade name: Diana Process Oil NS-90S, petroleum hydrocarbon) manufactured by Idemitsu Kosan Co., Ltd. were changed to 75 parts by mass and 25 parts by mass, respectively, the pressure-sensitive adhesive tape 1 was produced in the same manner as in Comparative Example 10, and then the laminate 20 was obtained.

[0157] 2. Production of the nozzle plate 30 According to the method shown in FIG. 6(a), for each laminate 20 in which the adhesive tapes 1 prepared in Examples 1 to 17 and Comparative Examples 1 to 11 were respectively bonded to the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate, from the side of the base material surface of the base material 5 for the nozzle plate (the surface opposite to the surface on which the liquid-repellent layer 6 was formed), using a laser oscillator 7, under a temperature condition of 23° C., a solid laser (YAG-UV, wavelength: 266 nm) was irradiated, and cutting and dividing were performed into 24 nozzle plates with a size of 81.5 mm in length and 4.6 mm in width. At the time of cutting and dividing, the base material 5 for the nozzle plate, the liquid-repellent layer 6, and the adhesive layer 3 of the adhesive tape 1 were penetrated (cut), but the outer shape processing was such that the base material 2 of the adhesive tape 1 was not penetrated (cut). After cutting and dividing, cleaning water composed of pure water and air was jetted onto the surface of the laminate 20 to remove the decomposition residue deposits generated during laser cutting.

[0158] Next, according to the reduction transfer method using the mask pattern shown in FIG. 6(b), using a laser oscillator 7, a KrF pulsed oscillation excimer laser (wavelength: 248 nm, repetition frequency: 100 Hz) was irradiated, and under a temperature condition of 23° C., nozzle holes were formed so that the diameter on the nozzle outlet side was about 23 μm. At the time of forming the nozzle holes, the base material 5 for the nozzle plate, the liquid-repellent layer 6, and the adhesive layer 3 of the adhesive tape 1 were penetrated, but the hole processing was such that the base material 2 of the adhesive tape 1 was not penetrated. The number of nozzle holes per nozzle plate was 256 per row, and 4 rows were formed.

[0159] 3. Evaluation method Subsequently, the evaluation methods for the characteristics of the adhesive tape 1 and the laser processability in the laminate 20 will be described.

[0160] <Tape characteristics> Thickness of the adhesive tape 1 The thicknesses of the adhesive tapes 1 prepared in Examples 1 to 17 and Comparative Examples 1 to 11 were measured using a dial gauge according to JIS Z 0237 (2009).

[0161] (2) Adhesive force to the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate Under the temperature condition of 23°C, for the adhesive tapes 1 prepared in Examples 1 to 17 and Comparative Examples 1 to 11, an adhesion test (peel adhesion test) was conducted on the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate in accordance with the method described in JIS Z 0237 (2009). Specifically, the adhesive tape 1 was attached to the liquid-repellent layer 6 formed on the base material 5 for the nozzle plate, and a roller with a mass of 2000 g was reciprocated twice at a speed of 5 mm / second for crimping. Subsequently, using a tensile tester, the adhesion force was measured when peeling off at a speed of 5 mm / second in the 90° direction with respect to the base material 5 for the nozzle plate.

[0162] (3) Tack of the adhesive layer 3 Under the temperature condition of 23°C, for the adhesive tapes 1 prepared in Examples 1 to 17 and Comparative Examples 1 to 11, evaluation was carried out using a ball rolling device in accordance with JIS Z 0237 (2009). Specifically, using a ball rolling device equipped with an inclined plate with an inclination angle of 20°, the ball was rolled so that the length of the auxiliary walking path was 100 mm, and the maximum ball number that stopped within the adhesive surface (measurement part) in the range of 100 mm from the lower end of the auxiliary walking path was obtained and used as each tack.

[0163] (4) Storage modulus (G’) of the adhesive layer 3 The storage elastic modulus (G’) of the pressure-sensitive adhesive layer 3 of the pressure-sensitive adhesive tapes 1 produced in Examples 1 to 17 and Comparative Examples 1 to 11 was measured by the following method. First, for the pressure-sensitive adhesive solutions for coating adjusted in each Example and Comparative Example, they were respectively coated on the first release film, dried and cured under the same conditions as in each Example and Comparative Example, and the second release film was laminated to obtain a pressure-sensitive adhesive tape (substrate-free). Subsequently, each of the obtained pressure-sensitive adhesive tapes was cut into small pieces, the release film was peeled off, and a sample was prepared by stacking only the pressure-sensitive adhesive layer to a thickness of about 500 μm. For these samples, the dynamic viscoelasticity was measured using a viscoelasticity measuring device “DMA6100” (product name) manufactured by Hitachi High-Technologies Corporation, and the storage elastic modulus (G’) of the pressure-sensitive adhesive layer 3 was determined. The measurement conditions were as follows: while applying shear strain under the condition of a frequency of 100 Hz, the temperature was changed from 0 °C to 100 °C at a temperature rising rate of 2 °C / min, and the dynamic viscoelasticity spectrum was measured respectively. Then, from the viscoelasticity spectrum, the storage elastic modulus (G’) at 23 °C 100Hz was determined.

[0164] <Laser processability in the laminate 20> (1) Adhesiveness, positional deviation For the laminates 20 produced in Examples 1 to 17 and Comparative Examples 1 to 11, under the temperature condition of 23 °C, outer shape processing (cutting and dividing into 24 pieces) was respectively performed using an excimer laser by the method described above. After washing and removing decomposition residue deposits and the like during the laser processing, the presence or absence of air bubble entrapment at the interface between the pressure-sensitive adhesive layer 3 and the liquid-repellent layer 6 was visually confirmed to evaluate the adhesiveness. In addition, the amount of positional deviation of the cut and divided pieces of the base material 5 for the nozzle plate on which the liquid-repellent layer was formed with respect to the predetermined processing line of the laser on the pressure-sensitive adhesive tape 1 was measured with a laser microscope, and it was evaluated whether the amount of positional deviation was within the range of ±25 μm. The evaluation was performed for all 24 cut and divided pieces.

[0165] The evaluation criteria were as follows, and an evaluation of B or higher was regarded as passing. A: All 24 pieces had no air bubble entrapment and the amount of positional deviation was within the range of ±25 μm. B: Out of 24 pieces, the number of pieces without air bubble entrapment and with the positional deviation amount within the range of ±25 μm was 22 to 23 pieces. C: Out of 24 pieces, the number of pieces without air bubble entrapment and with the positional deviation amount within the range of ±25 μm was 21 pieces or less.

[0166] (2) Variation in the diameter of the nozzle holes For the cut and divided pieces of each laminate 20 of the examples and comparative examples machined by an excimer laser, nozzle holes with a diameter of approximately 23 μm were machined using an excimer laser by the method described above under the temperature condition of 23°C. After peeling off the adhesive tape 1, the diameter of the holes on the nozzle exit side (the side where the liquid repellent layer 6 is formed) of the nozzle plate 30 was measured with a laser microscope, and the 3σ (σ: standard deviation) of the diameters of 60 arbitrary nozzle holes was obtained. Specifically, three arbitrary pieces were extracted from 24 pieces of the cut and divided pieces (nozzle plate 30) on which the nozzle hole machining was performed, and for 20 arbitrary nozzle holes per piece, a total of 60 arbitrary nozzle holes from 3 pieces were measured for their diameters, and the value of 3σ was obtained. According to the following evaluation criteria, the degree of variation in the diameter of the nozzle holes was evaluated. The diameter of the nozzle holes was measured at a total of 4 locations: vertical, horizontal, and diagonal, and the average value was taken as the diameter of the nozzle hole.

[0167] The evaluation criteria were as follows, and an evaluation of B or above was considered a pass. A: The value of 3σ of the diameter was 0.4 μm or less. B: The value of 3σ of the diameter exceeded 0.4 μm but was within the range of 0.5 μm or less. C: The value of 3σ of the diameter exceeded 0.5 μm.

[0168] (3) Shape of the nozzle holes Regarding the shape of the holes on the nozzle exit side of 60 arbitrary nozzle holes selected in the evaluation of the variation in the diameter of the nozzle holes in (2) above, they were observed with a laser microscope. Specifically, the presence or absence of sag at the edge portion of the nozzle holes, the presence or absence of burr generation at the edge portion, and the measurement of the height of the burr were performed, and the shape of the nozzle holes was evaluated according to the following evaluation criteria.

[0169] The evaluation criteria were as follows, and an evaluation of B or above was considered a pass. A: Among 60 nozzles, the number of nozzles without sag at the distinct edge part, without burr generation, or with a burr height of 0.5 μm or less was 57 or more and 60 or less. B: Among 60 nozzles, the number of nozzles without sag at the distinct edge part, without burr generation, or with a burr height of 0.5 μm or less was 54 or more and 56 or less. C: Among 60 nozzles, the number of nozzles without sag at the distinct edge part, without burr generation, or with a burr height of 0.5 μm or less was 53 or less.

[0170] (4) Nozzle hole clogging After performing the above nozzle hole processing, three arbitrary pieces were extracted from 24 cut and divided pieces (nozzle plates 30) peeled from the adhesive tape 1. For 1024 nozzle holes per piece, a total of 3072 nozzle holes in 3 pieces, the presence or absence of nozzle hole clogging due to the adhesive was observed with an optical microscope, and the occurrence rate of nozzle hole clogging for 3072 nozzle holes was determined.

[0171] The evaluation criteria were as follows, and an evaluation of B or above was considered a pass. A: The occurrence rate of nozzle hole clogging was less than 3.0%. B: The occurrence rate of nozzle hole clogging exceeded 3.0% and was 5.0% or less. C: The occurrence rate of nozzle hole clogging exceeded 5.0%.

[0172] 3. Evaluation results The evaluation results of Examples 1 to 17 are shown in Tables 1 to 3, and the evaluation results of the adhesive tapes 1 of Comparative Examples 1 to 11 are shown in Tables 4 and 5.

[0173]

Table 1

[0174]

Table 2

[0175]

Table 3

[0176]

Table 4

[0177]

Table 5

[0178] As shown in Tables 1 to 3, when manufacturing the nozzle plate of an inkjet head from a substrate for a nozzle plate with a liquid-repellent layer by laser processing and applying the pressure-sensitive adhesive tapes of Examples 1 to 17 that meet the requirements of the present invention, it was confirmed that good results were obtained in all evaluation items such as adhesiveness, positional deviation, variation in the diameter of nozzle holes, nozzle hole shape, and nozzle hole clogging. That is, it was found that by using the pressure-sensitive adhesive tapes of Examples 1 to 17 that meet the requirements of the present invention, a high-quality nozzle plate of an inkjet head with good processing accuracy of nozzle holes can be manufactured with a high yield.

[0179] On the other hand, as shown in Tables 4 and 5, when applying the pressure-sensitive adhesive tapes of Comparative Examples 1 to 11 that do not meet the requirements of the present invention, it was confirmed that at least one of the evaluation items such as adhesiveness, positional deviation, variation in the diameter of nozzle holes, nozzle hole shape, and nozzle hole clogging was inferior compared to the pressure-sensitive adhesive tapes of Examples 1 to 17.

[0180] Specifically, the pressure-sensitive adhesive tapes of Comparative Examples 1, 3, and 5 in which the content of the tackifier resin in the adhesive layer 3 is less than 23 parts by mass have low adhesive force to the liquid-repellent layer 6 and low tack of the adhesive layer 3, and it was confirmed that they are inferior compared to the pressure-sensitive adhesive tapes of the examples in the evaluation items of adhesiveness, positional deviation, variation in the diameter of nozzle holes, and nozzle hole shape.

[0181] In addition, for the pressure-sensitive adhesive tapes of Comparative Examples 2, 4, 6, 9, and 10 in which the content of the tackifier resin in the adhesive layer 3 exceeds 78 parts by mass, since the tackifier resin is unevenly distributed on the surface of the adhesive layer 3 and the cohesive force of the adhesive layer 3 decreases, it was confirmed that they are inferior compared to the pressure-sensitive adhesive tapes of the examples in the evaluation item of nozzle hole clogging.

[0182] Furthermore, since the adhesive layer 3 does not contain process oil, the value of the storage elastic modulus at 23°C at a measurement frequency of 100 Hz exceeds 6.6×10, which is the upper limit value of the claims of the present invention. 5The pressure-sensitive adhesive tape of Comparative Example 7, which is Pa, has a small adhesive force to the liquid-repellent layer 6, and it was confirmed that it is inferior to the pressure-sensitive adhesive tape of the Example in terms of the adhesion property and the positional deviation evaluation item.

[0183] Furthermore, since the content of the process oil in the adhesive layer 3 is excessively large, the value of the storage elastic modulus at 23 °C at a measurement frequency of 100 Hz is 1.7×10 which is less than the lower limit value of the claims of the present invention. 5 Pa for Comparative Example 8 and 1.5×10 5 The pressure-sensitive adhesive tape of Comparative Example 11, which is Pa, has an excessively low hardness as the adhesive layer 3 applied to laser processing with a repetition frequency of 100 Hz, and it was confirmed that it is inferior to the pressure-sensitive adhesive tape of the Example in terms of the evaluation item of nozzle hole clogging.

Explanation of symbols

[0184] 1... Pressure-sensitive adhesive tape, 2... Base material, 3... Adhesive layer, 4... Release liner, 5... Base material for nozzle plate, 6... Liquid-repellent layer, L ··· Laser beam, h ··· Nozzle hole, 7, 9... Laser oscillator, 8... Outer shape processing line, 10... Homogenizer optical system, 11... Photomask, 12... Mask pattern M ··· Reflective mirror, 13... Objective lens, 20... Laminate, 30... Nozzle plate, 40... Ink flow path member, 41... Ink chamber, 42... Front end face, 100... Inkjet head

Claims

1. When performing external shaping and nozzle hole processing on a base material for a nozzle plate of an inkjet head having a liquid-repellent layer formed on its surface by laser, it is used by being attached to the liquid-repellent layer formed on the base material for the nozzle plate. An adhesive tape comprising a base material and an adhesive layer laminated on one surface of the base material, wherein the adhesive layer of the adhesive tape, A) a styrene-isoprene-styrene block copolymer, B) a process oil composed of a petroleum-based hydrocarbon, C) an adhesion-imparting resin containing at least one selected from the group consisting of an aliphatic hydrocarbon resin, an aliphatic / aromatic copolymer hydrocarbon resin, a hydrogenated petroleum resin, and a terpene resin is included, The adhesive layer of the adhesive tape has a storage elastic modulus (G') at 23°C when measuring the dynamic viscoelasticity under the conditions of a frequency of 100 Hz and a heating rate of 2°C / min in the shear mode. １００Ｈｚ is 3.0×10 ５ Pa or more and 6.5×10 ５ Pa or less, and and the content of the adhesion-imparting resin in the adhesive layer of the adhesive tape is in the range of 23 parts by mass or more and 78 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer. The adhesive tape is characterized by this.

2. The styrene-isoprene-styrene block copolymer has a styrene content in the range of 14% by mass or more and 25% by mass or less, and a styrene-isoprene diblock content in the range of 12% by mass or more and 78% by mass or less. The adhesive tape according to claim 1.

3. The softening point of the adhesion-imparting resin is in the range of 80°C or more and 135°C or less. The adhesive tape according to claim 1 or 2.

4. The content of the process oil composed of the petroleum-based hydrocarbon is in the range of 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the styrene-isoprene-styrene block copolymer. The adhesive tape according to any one of claims 1 to 3.

5. The liquid-repellent layer has a contact angle of distilled water on the surface of the liquid-repellent layer in the range of 110° or more and 180° or less. The adhesive tape according to any one of claims 1 to 4.

6. The liquid-repellent layer is composed of a fluorine-based compound, and the fluorine-based compound is (1) a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoroalkyl group, (2) a compound having at least one group selected from the group consisting of an alkoxysilyl group, a phosphonic acid group, and a hydroxy group and a perfluoropolyether group, (3) a mixture containing a compound having a perfluoroalkyl group, or (4) a mixture containing a compound having a perfluoropolyether group. The adhesive tape according to any one of claims 1 to 5.

7. The pressure-sensitive adhesive tape according to any one of claims 1 to 6, wherein the tack of the pressure-sensitive adhesive layer is in the range of 6 or more and 14 or less.

8. A step of laminating the pressure-sensitive adhesive tape according to any one of claims 1 to 7 onto a base material for a nozzle plate of an inkjet head having a liquid-repellent layer formed on the surface thereof so that the pressure-sensitive adhesive layer and the liquid-repellent layer face each other; A step of machining the outer shape of the base material for the nozzle plate of the inkjet head into a nozzle plate having a desired size to be mounted on the inkjet head using a laser on the pressure-sensitive adhesive tape; A step of forming nozzle holes in the outer-shaped nozzle plate using a laser; and A step of peeling the pressure-sensitive adhesive tape from the obtained nozzle plate; A method for manufacturing a nozzle plate of an inkjet head, comprising:

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