Removable adhesive tape, manufacturing method thereof and method for improving sealing of nozzle plate

Abstract

The invention provides a removable adhesive tape, a manufacturing method thereof and a method for improving sealing of a nozzle plate. The removable tape comprises: a polymeric backing film; a first platinum cured silicone adhesive layer having a first adhesive strength applied to the polymeric backing film; and a second platinum cured silicone adhesive layer having a second adhesive strength applied to the first adhesive layer. The second platinum cured adhesive layer is configured to adhere to a nozzle plate of a fluid ejection cartridge.

Description

Technical Field

[0001] The present disclosure relates to the field of fluid ejection cartridges and more particularly to an improved sealing tape for a fluid ejection cartridge, and more particularly to a removable tape and a method for making the tape and a method for improving the sealing of a nozzle plate. Background Art

[0002] Thermal inkjet printing has been around for decades as a way to eject fluid onto a substrate. Traditionally, inkjet printers were used to print water-based inks on paper, usually in a home or office setting. However, the inkjet printing market has shifted to commercial and industrial applications as demand for at-home printing has declined. Commercial inkjet printing consumers use aggressive solvents and ink formulations to print on a variety of materials including steel, glass, and cardboard. Therefore, due to this shift, fluid ejection heads and fluid ejection cartridges that are durable for non-traditional fluid formulations are needed.

[0003] In some cases, before installation or use, most of the life of the fluid jet box may be spent in the process from manufacturing to transportation and / or storage. Therefore, it is important that even if the box is kept stored for a long time period, the operability of the box will not deteriorate during transportation or storage. Usually, in order to maintain the operability of the box, a protective sealing tape or a plastic cover comprising an elastic seal can cover the jet head and the jet nozzle on the jet head. Both the plastic cover and the sealing tape are designed to prevent the jet head from being contaminated, prevent fluid from seeping out of the jet head, and reduce the amount of solvent evaporated from the fluid in the box during transportation and storage. Before use, remove the plastic cover or sealing tape from the fluid jet box, thereby exposing the jet nozzle. The plastic cover is effective in maintaining operability, but is much more expensive than the protective sealing tape.

[0004] Conventional pressure sensitive adhesive (PSA) sealing tapes used to seal nozzle holes in jet heads typically contain acrylic adhesives with polyvinyl chloride or polyethylene terephthalate backing films. These conventional acrylic adhesives are suitable for aqueous inks, but can be dissolved by more irritating solvents and fluid formulations used in commercial and industrial applications, thus causing fluid leakage from the fluid jet box and / or premature stripping of the tape from the jet head. Therefore, in order to ensure that the protective sealing tape is not stripped from the jet head prematurely, a suitable tape and adhesive system must be found that is not easily dissolved by these irritating solvents and ink formulations. The sealing tape must also be stable when heated during transportation and storage, and must be able to be completely removed from the jet head without leaving adhesive residue or damaging the underlying nozzle plate of the print head while also remaining firmly attached to the backing film. Therefore, there is a need for an improved adhesive tape sealing system that can be used for fluid jet boxes containing a wider variety of fluids and solvents. Summary of the invention

[0005] With respect to the foregoing, embodiments of the present disclosure provide an improved removable tape for a fluid jet cartridge and a method for making the improved removable tape. An advantage of the disclosed embodiments is that the removable adhesive tape material can be customized to be suitable for fluid jet cartridges containing a variety of fluids and solvents using a backing material having two layers of platinum-cured adhesive material with different peel strengths. The removable adhesive tape material can also be customized to have improved chemical resistance to fluids used in fluid jet cartridges by applying a larger thickness adhesive layer with greater adhesive strength directly to the backing material.

[0006] In one aspect of the present disclosure, a removable tape is configured to seal a nozzle plate attached to an ejection head and a portion of a fluid ejection box body that includes the ejection head. The removable tape includes: a polymeric backing film; a first platinum-cured silicone adhesive layer having a first adhesive strength applied to the polymeric backing film; and a second platinum-cured silicone adhesive layer having a second adhesive strength applied to the first adhesive layer. The second platinum-cured adhesive layer is configured to adhere to a nozzle plate on an ejection head of a fluid ejection box.

[0007] In some embodiments, the polymeric backing film may be selected from polyethylene terephthalate (PET), polypropylene, polyamide, and polyimide.

[0008] In some embodiments, the polymeric backing film has a thickness ranging from about 20 microns to about 30 microns, the first platinum-cured silicone adhesive layer has a thickness ranging from about 7 microns to about 20 microns on the polymeric backing film, and the second platinum-cured silicone adhesive layer has a thickness ranging from about 7 microns to about 20 microns on the first platinum-cured silicone adhesive layer.

[0009] In some embodiments, the polymeric backing film may include a corona treated polymeric backing film.

[0010] In some embodiments, the first adhesive strength is greater than the second adhesive strength.

[0011] In some embodiments, the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer may include different platinum-cured silicone adhesive base materials.

[0012] In some embodiments, wherein the first platinum-cured silicone adhesive base material is different from the second platinum-cured silicone adhesive base material, the first bonding strength may have a peel strength ranging from about 150 Newtons / meter (N / m) to about 500 N / m on a dry silicon wafer, and the second bonding strength has a peel strength ranging from about 25 N / m to about 65 N / m on a dry silicon wafer.

[0013] In some embodiments, the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer may include the same platinum-cured adhesive base material.

[0014] In some embodiments, wherein the first platinum-cured silicone adhesive base material is the same as the second platinum-cured silicone adhesive base material, the first adhesive strength has a peel strength on a dry silicon wafer ranging from about 150 Newtons per meter (N / m) to about 500 N / m, and the second adhesive strength has a peel strength on a dry silicon wafer ranging from about 25 N / m to about 65 N / m.

[0015] In another embodiment, the present disclosure provides a method for making a removable tape configured for sealing a nozzle plate. The method includes: providing a polymeric backing film; and mixing a crosslinker mixture comprising a platinum siloxane complex catalyst and polydimethylsiloxane (PDMS) and polymethylhydrosiloxane (PMHS) with a first platinum-cured silicone adhesive base material to provide a first platinum-cured silicone adhesive, and mixing the crosslinker mixture with a second platinum-cured silicone adhesive base material to provide a second platinum-cured silicone adhesive. The method also includes: applying a first layer of the first platinum-cured silicone adhesive having a first adhesive strength to the polymeric backing film, and applying a second layer of the second platinum-cured silicone adhesive having a second adhesive strength to the first layer. The method also includes curing the first adhesive layer and the second adhesive layer.

[0016] In certain embodiments, the method includes sequentially curing a first layer and a second layer of platinum-cured silicone adhesive. In a variation of this embodiment, the curing step includes first partially curing the first platinum-cured silicone adhesive layer at a temperature of at least about 90° C. for about 1 minute, and then curing the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer together at a temperature ranging from about 120° C. to about 150° C. for about 2 minutes to about 3 minutes.

[0017] In certain embodiments, the method includes simultaneously curing a first layer and a second layer of platinum-cured silicone adhesive. In a variation of this embodiment, the first adhesive layer and the second adhesive layer are simultaneously cured at a temperature ranging from about 120° C. to about 150° C. for about 2 minutes to about 3 minutes.

[0018] In certain embodiments, the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer include different platinum-cured adhesive base materials.

[0019] In certain embodiments, the first platinum-cured silicone adhesive and the second platinum-cured silicone adhesive include the same platinum-cured adhesive base material.

[0020] In a variation of the embodiment in which the first adhesive base material is the same as the second adhesive base material, the method may also include mixing a first amount of a cross-linker mixture with the first platinum-cured silicone adhesive base material and mixing a second amount of a cross-linker mixture with the second platinum-cured silicone adhesive base material, wherein the second amount of the cross-linker mixture is greater than the first amount of the cross-linker mixture.

[0021] In another aspect, the present disclosure provides a method for improving the sealing of a nozzle plate of an ejector head attached to a fluid ejection box containing a fluid. The method includes providing a box body having a cover that closes a first end of the box body, an ejector head located on a second end of the box body opposite to the first end, and side walls bonded to the first end and the second end between the first end and the second end. The side walls include a first side wall, a second side wall opposite to the first side wall, a first end wall bonded to the first side wall and the second side wall, and a second end wall bonded to the first side wall and the second side wall opposite to the first end wall. The method also includes bonding a removable tape to the nozzle plate of the ejector head and a portion of the box body. The removable tape includes a polymeric backing film and a platinum-cured silicone adhesive layer, the adhesive layer having a first bonding strength adjacent to the backing film and a second bonding strength adjacent to the nozzle plate that is less than the first bonding strength.

[0022] In some embodiments, the first adhesive strength has a peel strength ranging from about 150 Newtons per meter (N / m) to about 500 N / m on a dry silicon wafer, and the second adhesive strength has a peel strength ranging from about 25 N / m to about 65 N / m on a dry silicon wafer.

[0023] In some embodiments, the modified platinum-cured silicone adhesive layer has a thickness on the polymeric backing film ranging from about 20 microns to about 30 microns.

[0024] The disclosed embodiments provide a unique adhesive tape including two adhesive layers configured to provide a removable protective tape for jetting heads of fluid cartridges suitable for use with a variety of jetting fluids. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other advantages of the present disclosure will become apparent by referring to the detailed description in conjunction with the accompanying drawings, which are not drawn to scale in order to more clearly illustrate details, wherein like reference numerals indicate like elements throughout the several views, and in which:

[0026] Figure 1 is a side perspective view of a fluid ejection cartridge according to an embodiment of the present disclosure.

[0027] Figure 2 yes Figure 1 An end perspective view of a fluid ejection cartridge is shown.

[0028] Figure 3 yes Figure 1 A top perspective view of an ejection head of a fluid ejection cartridge is shown.

[0029] Figure 4 yes Figure 1 A schematic, exploded view, not drawn to scale, of a fluid ejection cartridge is shown.

[0030] Figure 5 It is used to protect Figure 1 A perspective view, not drawn to scale, of the protective sealing tape and peel sticker of an ejection head of a fluid ejection cartridge is shown.

[0031] Figure 6 is a cross-sectional view, not drawn to scale, of a protective sealing tape according to a first embodiment of the present disclosure.

[0032] Figure 7 is a cross-sectional view, not drawn to scale, of a protective sealing tape according to a second embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] Reference Figure 1 , a fluid jet cartridge 10 is shown, the fluid jet cartridge 10 comprising a protective sealing tape 12 and a pull tape 14 overlapping a portion 16 of the protective sealing tape 12. The protective sealing tape 12 is used to cover a nozzle plate 18 of an ejection head 20 attached to the fluid jet cartridge 10. The protective sealing tape 12 prevents contamination and damage to the ejection head 20 and seals the nozzle holes in the nozzle plate 18 so that the fluid in the fluid jet cartridge 10 does not leak out or dry out and clog the nozzle holes during transportation and storage of the fluid jet cartridge 10.

[0034] like Figure 2 As shown, the flexible circuit 22 is electrically connected to the injection head 20 to control the fluid to be ejected from the fluid injection box 10 when the fluid injection box 10 is used. The flexible circuit has an electrical contact 24, which is arranged on the first end wall 26 of the fluid injection box 10 for electrically connecting to a fluid injection device, such as a printer, an inhaler, an e-cigarette, a digital dispense system, etc. (not shown). The cover 28 is attached to the first end 30 of the fluid injection box 10, and the first end 30 is opposite to the second end 32 of the fluid injection box including the injection head 20. The easy-tear label 14 and the protective sealing tape 12 are removably attached to the fluid injection box body, for example, attached to the first side wall 34 ( Figure 1 The fluid ejection box 10 further includes a second side wall 38 opposite to the first side wall 34 and a second end wall 40 opposite to the first end wall 26 .

[0035] Before installing and using the cartridge 10 in a fluid ejection device, the tear-off tape 14 is peeled off from the body of the fluid ejection cartridge 10 by grasping a tab on one end of the tear-off tape 14 and pulling the tear-off tape 14 away from the body of the fluid ejection cartridge 10. When the tear-off tape 14 is removed from the fluid ejection cartridge 10, the protective sealing tape 12 adhered to the tear-off tape 14 in the overlap region 16 is also removed from the fluid ejection cartridge 10, so that the fluid can then be ejected from the ejection head 20.

[0036] Additional details of the fluid jet cartridge 10 may be found at Figure 4 1. The ejection head 20 includes a semiconductor substrate 42 to which the flexible circuit 22 is electrically attached, and the nozzle plate 18 is attached to the semiconductor substrate 42 in a window (not shown) of the flexible circuit 22. In some embodiments, the fluid ejection cartridge 10 is filled with an open cell foam material 46 that holds the fluid to be ejected from the ejection head 20 and provides back pressure to the fluid to reduce the flow of the fluid from the ejection head 20. In other embodiments, the body of the fluid ejection cartridge 10 does not have a back pressure device.

[0037] In the embodiments described herein, as described above, the protective sealing tape 12 is used to cover and protect the nozzle holes on the nozzle plate 18. In addition to one or more adhesive layers 51 ( Figure 6 ), the protective sealing tape 12 also has a polymeric base film layer or "backing film" 50 ( Figure 6 ). The backing film 50 comprises polyethylene terephthalate, polypropylene, polyethylene, polybutylene, polybutadiene, polymethylpentene, polybutylene terephthalate, polyurethane, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-meth(acrylic acid) alkyl ester copolymer, polystyrene, polyimide, polyamide or polycarbonate, and has a thickness of about 10 microns to about 40 microns, preferably about 20 microns to about 30 microns. A particularly preferred polymeric backing film material is polyimide.

[0038] It should be understood that the ejection head 20 with its semiconductor substrate 42 and nozzle plate 18 is a precisely manufactured device capable of high-resolution fluid ejection. Therefore, protection of the ejection head 20 is important for proper operation of a fluid ejection device using the cartridge 10. Figure 1As shown, the protective sealing tape 12 is applied to the injection head 20 and the main body of the fluid injection box 10, and the easy-tear label 14 is applied to the main body of the fluid injection box 10 and adjacent to one end of the protective sealing tape 12. In some embodiments, the protective sealing tape 12 is configured to be peeled off from the injection head 20 in a direction orthogonal to the longitudinal direction of the nozzle plate 18 and the substrate 42. This peeling direction will effectively reduce the stress that may occur in the injection head 20 when the protective sealing tape 12 is peeled off from the injection head 20, and reduce the possibility of the nozzle plate 18 peeling off from the substrate 42. Therefore, it is desirable that the protective sealing tape 12 be peeled off in an orthogonal direction relative to the injection head, rather than in the longitudinal direction. In addition, it is important that the protective sealing tape 12 (e.g., the protective sealing tape 12a or 12b ( Figure 6 to Figure 7 ))'s adhesive layer 51 or 52 contains very few impurities because the adhesive layer 51 or 52 is in close contact with the nozzle plate 18 and may contaminate the nozzle holes in the nozzle plate 18, so if any residue remains on the nozzle plate 18, it will prevent the nozzle holes from operating properly.

[0039] The protective sealing tape 12 includes a front side 58 of the protective sealing tape 12 and a back side 54 of the protective sealing tape 12. Figure 1 and Figure 5 As shown, it is important that the peelable sticker 14 overlaps the back side 54 of the protective sealing tape 12 to improve the removal of the protective sealing tape 12 from the box 10. The adhesive material used on the lower side 56 of the peelable sticker 14 is not particularly important for the disclosed embodiment. Therefore, the peelable sticker adhesive can be a pressure-sensitive adhesive selected from, for example, various radiation-curable polymers such as epoxy resins, dienes, urethanes, polyimides, acrylic acid, silicones, and vinyl ester polymers including polymerization initiators. Examples of usable acrylic polymers include homopolymers or copolymers of (meth) alkyl acrylates, and copolymers of (meth) acrylates and another copolymerizable monomer, such as (meth) hydroxyalkyl acrylates, (meth) glycidyl acrylates, (meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylamide, (meth) acrylic acid N-hydroxymethylamide, (meth) alkylaminoalkyl acrylates, silicone adducted acrylates, vinyl acetate, styrene or acrylonitrile. In addition to acrylic and epoxy adhesive materials, polyimide and silicone-based materials may also be used as the base material for the pressure-sensitive adhesive layer on the underside 56 of the peel sticker 14. The adhesive used on the underside 56 of the peel sticker 14 has a peel strength that is approximately 2 times greater than the peel strength of the portion of the protective sealing tape 12 that contacts the nozzle plate, and desirably at least about 3 times greater.

[0040] Platinum-cured silicone-based adhesives are suitable adhesive base materials for forming the adhesive layer of the protective sealing tape 12 that will contact and seal the nozzle holes in the nozzle plate 18. Platinum-cured silicone-based adhesives have been found to be particularly chemically resistant to organic solvent-based fluids, thereby maintaining suitable peel strength for extended periods of time when exposed to organic solvent-based fluids in the cartridge 10. Conventional adhesives (e.g., acrylic adhesives, peroxide-catalyzed silicone adhesives, natural and synthetic rubber-based adhesives, and hot melt adhesives) fail to maintain suitable peel strength and / or fail to remain in place on the nozzle plate despite relatively high initial peel strengths.

[0041] According to the present disclosure, a platinum-cured silicone adhesive is made by cross-linking the silane groups of polydimethylsiloxane (Formula I) with a high molecular weight vinyl end-capped polydimethylsiloxane (Formula II) in the presence of a platinum catalyst and heat to provide a platinum-cured silicone adhesive according to the following reaction,

[0042]

[0043] The cross-linked platinum-cured silicone adhesive is highly resistant to organic solvents and provides a significantly improved adhesive tape for sealing fluid jet ejection heads. The platinum-cured silicone adhesive was found to be more resistant to harsh environments than acrylics, rubbers, synthetic rubbers, acrylic / rubber blends, or hot melt adhesives.

[0044] However, one problem that arises when using a platinum-cured silicone adhesive is that the adhesive layer needs to have suitable strength of adhesion at two interfaces: at the interface of the adhesive layer and the nozzle plate 18 of the ejection head 20, and at the interface of the adhesive layer and the backing film 50. An adhesive layer including a single platinum-cured silicone adhesive layer will provide a single strength of adhesion at two interfaces, which may render the protective sealing tape 12 ineffective. For example, if the adhesion strength between the adhesive layer and the nozzle plate 18 is too great, removing the protective sealing tape 12 from the ejection head 20 may damage the fragile photoresist layer of the ejection head 20—for example, destroying the channel formed between the nozzle plate 18 layer and the fluid flow layer of the ejection head 20—and thus rendering the cartridge inoperable. Similarly, if the adhesion strength between the adhesive layer and the backing film is too low, removing the protective sealing tape 12 from the ejection head 20 will cause the adhesive layer to remain adhered to the ejection head 20, thereby preventing fluid from flowing out of the cartridge 10 and again rendering the cartridge inoperable.

[0045] The traditional method of achieving the desired balance and preventing nozzle plate failure is to add adhesive "deadening" agents to the tape formulation to reduce the adhesion of the tape to the desired level for both interfaces. For example, for acrylic adhesives used to seal printheads containing aqueous ink formulations, the adhesive contains plasticizers to reduce adhesion to acceptable levels. However, adhesion deadening agents tend to hinder the chemical resistance of silicone-based adhesive formulations. Therefore, pure and unmodified silicone adhesives are preferred to maintain suitable chemical resistance.

[0046] In addition, in order to improve the adhesion strength between the adhesive layer and the polymeric backing film, the backing film can be subjected to corona treatment before the adhesive material is applied to the backing film. In addition, an anchoring material can be added to the highly cross-linked adhesive formulation to improve the adhesion between the adhesive and the polymeric backing film. A suitable anchoring additive is 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, which is available from Dow Chemical Company under the trade name SYL-OFF 9176. Based on the gross weight of the adhesive formulation, the amount of the anchoring additive in the adhesive formulation can range from about 0.2% by weight to about 0.4% by weight.

[0047] To advance additional solutions, initial testing of potentially suitable adhesive layer materials was conducted using various pure and unmodified platinum-cured silicone adhesive base materials of varying adhesive strengths, including materials from The Dow Chemical Company. Among the materials tested, some of the materials included platinum-cured silicone adhesive base materials with trade names DOWSIL 7646, DOWSIL 7652, DOWSIL 7667, and DOWSIL 7657. Testing determined that DOWSIL 7667 provided an almost acceptable level of adhesion. DOWSIL 7652 had too little adhesion to the backing film and would remain on the nozzle plate 18, while DOWSIL 7657 had too much adhesion and would damage the photoresist layer of the ejector head 20. Although DOWSIL 7667 provided somewhat satisfactory adhesion results, the frequency of adhesion failures at both interfaces was not satisfactory.

[0048] To solve the adhesion problem at the interface, it was determined that the adhesive layer can be formed from multiple layers of a platinum-cured silicone adhesive base material. By utilizing the similar chemistry and the same cross-linking mechanism of the platinum-cured silicone adhesive base material, an adhesive layer can be prepared that has a rigid, high-adhesion structure on the side facing the backing film and a soft, low-adhesion structure on the side facing the nozzle plate.

[0049] exist Figure 6In one exemplary embodiment shown, the adhesive layer 51 of the sealing tape 12a may include two different layers. The first adhesive layer 60 in contact with the backing film 50 may include an adhesive base material that exhibits excellent cross-linking and high adhesion in a cured form at the expense of reduced wettability, such as DOWSIL 7657. The second adhesive layer 62 is applied to the first adhesive layer 60. The second adhesive layer 62, which is configured to contact the nozzle plate 18, may include one or more adhesive base materials (such as DOWSIL 7652) that exhibit less cross-linking and lower adhesion in a cured form, or a base material (such as DOWSIL 7667) with a lower adhesion base material (such as DOWSIL 7652 or DOWSIL 7646) mixed in various proportions (such as but not limited to 90% DOWSIL 7667 and 10% DOWSIL 7652 or DOWSIL 7646) to achieve an acceptable adhesive strength, or an alternative formulation with other platinum-cured silicone adhesive base materials.

[0050] In another aspect, the first adhesive layer 60 and the second adhesive layer 62 may comprise the same adhesive base material, but depending on the molar ratio of the crosslinker (I) added to the adhesive base material containing PDMS (II), the adhesion strength may be effectively "weakened" to an acceptable level. This single adhesive base material approach can reduce the manufacturing cost of the tape by eliminating the need for two different silicone adhesive base materials to produce the above-mentioned adhesive layer 51, and has adhesion strength properties that can be easily modified and optimized for various other applications while still maintaining purity at the expense of some chemical resistance of the modified material. In applications where the adhesion strength of the adhesive base material is optimized, the ideal molar ratio of the crosslinker (I) to the PDMS (II) in the adhesive base material is 2:1, which provides a 1:1 ratio of hydrogen to vinyl functional groups in the mixture of the crosslinker (I) and PDMS (II). According to product literature for crosslinking by hydrosilation (addition), excessive amounts of crosslinking agent degrade the crosslink density and result in compromised performance of the cured adhesive base material in the form of reduced adhesion strength, crosslink density, tack, chemical resistance and other performance properties. It has been found that any amount of crosslinking agent above the optimum amount results in some degree of degradation of the crosslink density and performance properties.

[0051] In an exemplary embodiment, the first adhesive layer 60 of the adhesive layer 51 in contact with the backing film 50 may include an adhesive base material with relatively high adhesion strength (e.g., Dow 7657), which is formulated with an optimal molar ratio of 2:1 of crosslinker (I) to PDMS (II) to maintain sufficient chemical resistance, backer adhesion, and strength. The second adhesive layer 62 of the adhesive layer 51 configured to contact the nozzle plate 18 may include the same adhesive base material with high adhesion strength (e.g., Dow 7657), which is formulated with a higher molar ratio of crosslinker to PDMS, such as, but not limited to, a molar ratio of 3:1, to reduce the adhesion strength of the second adhesive layer 62 to the nozzle plate 18.

[0052] In another embodiment, the first adhesive layer 60 and the second adhesive layer 62 may include different adhesive base materials, and depending on the molar ratio of the cross-linker (I) to PDMS (II), the adhesion strength may also be effectively "weakened" to an acceptable level. In an exemplary embodiment, the first adhesive layer may include an adhesive base material with greater adhesion strength (e.g., Dow 7657) formulated with an optimal molar ratio of cross-linker to PDMS of 2:1 to maintain sufficient chemical resistance, backing adhesion and strength. The second adhesive layer 62 of the adhesive layer 51 configured to contact the nozzle plate 18 may include an adhesive base material with high chemical resistance and higher adhesion strength (e.g., Dow 7667) formulated with a higher molar ratio of cross-linker to PDMS, such as, but not limited to, a molar ratio of 3:1, to reduce the adhesion strength of the second adhesive layer 62 to the nozzle plate 18 while still maintaining some increased chemical resistance.

[0053] As described above, the peel strength of the first adhesive layer 60 and the peel strength of the second adhesive layer 62 are selected to avoid failure at the following two interfaces: the interface between the backing film 50 and the first adhesive layer 60 and the interface between the second adhesive layer 62 and the nozzle plate 18. Therefore, the first adhesive layer 60 of the adhesive layer 51 has a peel strength in the range of about 150 N / m to about 500 N / m as measured using a 200 mm wide sample at a peel speed of 300 mm / min and an angle of 90 degrees on a silicon wafer. This range corresponds to an acceptable adhesion strength to avoid failure at the interface between the backing film 50 and the first adhesive layer 60. The second adhesive layer 62 of the adhesive layer 51 has a peel strength in the range of about 25 N / m to about 65 N / m as measured using a 200 mm wide sample at a peel speed of 300 mm / min and an angle of 90 degrees on a silicon wafer. This range corresponds to an acceptable adhesion strength to avoid failure at the interface between the second adhesive layer 62 and the nozzle plate 18. Since the adhesive strength of the first adhesive layer 60 is greater than that of the second adhesive layer, the second adhesive layer 62 is unlikely to be peeled off from the first adhesive layer 60 .

[0054] The protective sealing tape 12 can be produced by a method using conventional sealing tape manufacturing equipment (e.g., a slot die). In one embodiment, the method includes: providing a polymeric backing film; and preparing two different platinum-cured silicone adhesive compositions by mixing together the following two main components: (1) a platinum-cured silicone base material that can be supplied in a pre-mixed form in various Dow Chemical products (e.g., Dow 7652, 7657, 7646, and 7667); and (2) a crosslinker mixture, wherein the platinum-cured silicone base material includes an MQ silicone resin, a vinyl-terminated linear siloxane-based polymer (e.g., polydimethylsiloxane), or a copolymer (e.g., methylphenylsiloxane and diphenylsiloxane), or a similar compound, and one or more solvents (e.g., toluene, xylene, or ethylbenzene), wherein the crosslinker mixture includes: (a) a platinum siloxane complex catalyst, such as ... The invention relates to a method for preparing a platinum-cured silicone adhesive base material comprising: (a) a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum) supplied in a premixed form (e.g., SYL-OFF 4000 catalyst); and (b) a crosslinker comprising polydimethylsiloxane and polymethylhydrosilane, such as the crosslinkers supplied in premixed form in various Dow Chemical Company products (e.g., SYL-OFF 7678, 7215, and 7660). The components were mixed according to the manufacturer's technical data sheet for each adhesive base material (except when attenuation was required, in which case excess crosslinker was used, exceeding the optimal molar ratio of crosslinker to PDMS) to produce two different platinum-cured silicone adhesive base material compositions.

[0055] Then, the method includes coating the backing film 50 with a first adhesive layer 60 composed of a platinum-cured silicone adhesive base material composition having a high adhesion strength in a cured form (e.g., a composition including Dow 7657 or 7667). The slot die coater can distribute the adhesive base material onto the backing film 50 at a desired wet thickness corresponding to the amount of solvent present in the adhesive base material (i.e., the layer thickness when the platinum-cured silicone adhesive base material composition still contains solvent). The thickness of the cured layer can be approximately calculated by multiplying the wet film thickness by the solid ratio in the base material composition. For example, a layer comprising a base material composition having 50% by volume solvent and 50% by volume solid applied at a wet thickness of 100 microns will have a dry / cured thickness of 50 microns.

[0056] The method further includes applying a second adhesive layer 62 composed of a platinum-cured silicone adhesive base material composition having a lower adhesion strength in cured form, such as a composition including a mixture of Dow 7667 and Dow 7646, onto the first adhesive layer 60. Since the composition still contains solvent, the slot die coater can distribute the second adhesive layer 62 onto the first adhesive layer 60 at a desired wet thickness corresponding to the amount of solvent present in the adhesive base material.

[0057] The desired solidification thickness T1 of the first adhesive layer 60 and the thickness T3 of the second adhesive layer 62 can depend on several factors. In theory, no matter how thick, the first adhesive layer 60 will increase the adhesion between the adhesive layer 51 and the backing film 50. If it is the only goal to increase adhesion at this interface, the first adhesive layer 60 of about 7 microns thick will be acceptable. The lower limit of the thickness of 7 microns is for practical considerations, because, among other factors, due to the high viscosity of the platinum-cured silicone adhesive base material with higher adhesion, it is difficult to produce an acceptable uniform coating less than 7 microns thick. In some cases, the difficulties caused by high viscosity can be compensated by adding additional solvents in the base material composition, such as adding methyl ethyl ketone due to the low boiling point of methyl ethyl ketone compared with toluene or xylene. However, the larger platinum-cured silicone base material of adhesion under the cured form also shows a larger chemical resistance, and therefore, when the chemical resistance is the target, the first adhesive layer 60 should be thicker, and should account for the major part of the total thickness of the adhesive layer 51, preferably about 20 microns thick. In addition, the thicker first adhesive layer 60 also minimizes the "squeeze out" phenomenon - the phenomenon of adhesive layer 51 protruding from under backing film 50, which is common when using low-adhesion, low-viscosity platinum-cured silicone adhesive base materials and when sealing tape 12 is stored in roll form. Preferably, in the case where chemical resistance is given priority, second adhesive layer 62 accounts for about 1 / 5 to about 1 / 3 of the total thickness of adhesive layer 51. In a preferred embodiment where chemical resistance and adhesion of backing film 50 are given priority, the total thickness of adhesive layer 51 is 25 microns, the first adhesive layer 60 includes Dow 7667 adhesive base material and has a thickness of 18 microns, and the second adhesive layer 62 includes Dow 7652 adhesive base material and has a thickness of 7 microns. In the same preferred embodiment, the backing film includes polyimide and has a thickness T2 of 25 microns.

[0058] However, with the goal of having acceptable adhesion between the adhesive layer 51 and the nozzle plate 18 without damage, it may be preferred that the second adhesive layer 62 is thicker than the first adhesive layer 60. Some of the less adhesive adhesive base material migrates to the interface between the first adhesive layer 60 and the backing film 50 to still provide an acceptable strong adhesion between the adhesive layer 51 and the backing film 50. In addition, migration and mixing can be controlled and minimized by allowing the first adhesive layer 60 to partially dry or cure before coating the first adhesive layer 60 with the second adhesive layer 62, or the first adhesive layer 60 can be initially loaded with less solvent. Therefore, with the goal of acceptable adhesion, the second adhesive layer 62 should be thicker and should account for a majority of the total thickness of the adhesive layer 51, preferably about 20 microns thick. Preferably, the first adhesive layer 60 accounts for about 7 microns or more of the total cured thickness of the adhesive layer 51.

[0059] The method also includes one or more curing steps using a multi-zone oven or other suitable equipment. In one variation, the first adhesive layer 60 and the second adhesive layer 62 can be coated on the backing film 50 and cured simultaneously at about 120°C to 150°C for about 2 minutes to about 3 minutes. In another variation, the method may include sequentially curing the first adhesive layer 60 and the second adhesive layer 62 in two steps. In the first step, the first adhesive layer 60 can be partially cured for 1 minute at 90°C, and then the first adhesive layer 60 is coated with the second adhesive layer 62. In the second step, the partially cured first adhesive layer 60 and the second adhesive layer 62 are cured simultaneously at about 120°C to 150°C for about 2 minutes to about 3 minutes. Curing evaporates the solvent present in the adhesive base material composition and forms the cured thickness discussed herein.

[0060] Without being bound by theoretical considerations, it is believed that the long flexible siloxane chains of the second adhesive layer 62 can gradually intermix with the first adhesive layer 60 so that there is no gap between the first adhesive layer 60 and the second adhesive layer 62. Figure 7 Instead of a clear interface as shown, a gradual transition 64 is achieved from the first adhesive layer 60 to the second adhesive layer 62. Figure 7 , the combined adhesive layer 52 is formed by adhesive layers 62 and 60 of the same thickness T3 and T1, respectively, wherein the blending of the two layers 60 and 62 enables the two layers to achieve a gradual transition 64. Thus, without sacrificing the desired properties of the portion of the adhesive layer 52 in contact with the nozzle plate 18 (e.g., chemical resistance) and without the second adhesive layer 62 being separated from the first adhesive layer 60, the adhesive layer 52 remains firmly adhered to the backing film 50, but is cleanly detached from the nozzle plate 18 of the ejection head 20 without being damaged.

[0061] The following non-limiting examples illustrate embodiments of the present disclosure. In the following table, based on the supplier's information, formulations can be prepared to provide adhesives with specified strengths.

[0062] Table 1

[0063]

[0064] Adhesive 3 was prepared according to Table 1 and the peel strength of Adhesive 3 on a bare silicon wafer was tested as described above. The peel strength was 43 N / m. Adhesive 4 was prepared according to the table and the peel strength of Adhesive 4 on a bare silicon wafer was tested as described above. The peel strength was 24.5 N / m.

[0065] In some embodiments, the protective tape described herein may be preheated before using the fluid to fill the box. It is believed that preheating the protective tape greatly improves the conformity of the protective tape to the box, thereby preventing fluid leakage when heated during transportation and storage.

[0066] As described above, the fluid jet cartridge 10 can be used in a variety of applications including, for example, inkjet printing applications. The fluid jet cartridge can also be used in other non-printing applications, particularly applications where small amounts of liquid materials and vapor materials need to be accurately metered. For example, the jet cartridges described herein can be used in the preparation of cosmetics, paints, or lubricants and for medical liquid and vapor jetting, as well as in digital dispensing devices for analytical purposes.

[0067] The above description of the preferred embodiments of the present disclosure is provided for the purpose of illustration and description. The description and embodiments are not intended to be exhaustive or to limit the present disclosure to the exact form disclosed. Obvious modifications or changes can be made based on the above teachings. The embodiments are selected and described in order to provide the best illustration of the principles of the present disclosure and its practical application, and thereby enable ordinary technicians in the field to utilize the present disclosure in various embodiments and with various modifications suitable for the specific purpose intended. When interpreted according to the breadth that the attached claims fairly, legally and equitably possess, all such modifications and changes are within the scope of the present disclosure as determined by the attached claims.

Claims

1. A removable tape configured to seal a nozzle plate of an ejection head attached to a fluid ejection cartridge, the removable tape comprising: polymeric backing film; a first platinum-cured silicone adhesive layer having a first bond strength applied to the polymeric backing film; as well as A second platinum-cured silicone adhesive layer having a second adhesive strength is applied to the first platinum-cured silicone adhesive layer, wherein the second platinum-cured silicone adhesive layer is configured to adhere to the nozzle plate on the ejection head of the fluid ejection cartridge.

2. The removable tape of claim 1, wherein the polymeric backing film is selected from the group consisting of polyethylene terephthalate, polypropylene, polyamide, and polyimide.

3. The removable tape of claim 1 , wherein the polymeric backing film has a thickness in a range of 20 to 30 microns, the first platinum-cured silicone adhesive layer has a thickness in a range of 7 to 20 microns on the polymeric backing film, and the second platinum-cured silicone adhesive layer has a thickness in a range of 7 to 20 microns on the first platinum-cured silicone adhesive layer.

4. The removable tape of claim 1, wherein the polymeric backing film comprises a corona treated polymeric backing film. The removable tape of claim 1 , wherein the first adhesive strength is greater than the second adhesive strength.

6. The removable tape of claim 1, wherein the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer comprise different platinum-cured adhesive base materials.

7. The removable tape of claim 6, wherein the first adhesive strength has a peel strength ranging from 150 N / m to 500 N / m on a dry silicon wafer, and the second adhesive strength has a peel strength ranging from 25 N / m to 65 N / m on a dry silicon wafer.

8. The removable tape of claim 1, wherein the first platinum-cured silicone adhesive layer and the second platinum-cured silicone adhesive layer comprise the same platinum-cured adhesive base material.

9. The removable tape of claim 8, wherein the first adhesive strength has a peel strength ranging from 150 N / m to 500 N / m on a dry silicon wafer, and the second adhesive strength has a peel strength ranging from 25 N / m to 65 N / m on a dry silicon wafer.

10. A method of making a removable tape for making an improved removable tape configured to seal a nozzle plate of an ejection head attached to a fluid ejection cartridge, the method comprising: providing a polymeric backing film; mixing a crosslinker mixture comprising polydimethylsiloxane and polymethylhydrosilane with a first platinum-cured silicone adhesive base material to provide a first platinum-cured silicone adhesive, and mixing the crosslinker mixture with a second platinum-cured silicone adhesive base material to provide a second platinum-cured silicone adhesive; applying a first layer of the first platinum-cured silicone adhesive having a first bond strength to the polymeric backing film; applying a second layer of the second platinum-cured silicone adhesive having a second bond strength to the first layer; as well as The first layer and the second layer are cured. 11 . The method for making a removable tape according to claim 10 , wherein the method for making a removable tape comprises curing the first layer and the second layer in sequence.

12. The method for making a removable adhesive tape according to claim 11, wherein the curing comprises: The first layer is partially cured at a temperature of at least 90° C. for 1 minute, and then the first and second layers are cured at a temperature of 120° C. to 150° C. for 2 to 3 minutes. 13 . The method for making a removable tape according to claim 10 , wherein the method for making a removable tape comprises curing the first layer and the second layer simultaneously. 14 . The method for making a removable tape according to claim 13 , wherein the curing comprises curing the first layer and the second layer at a temperature of 120° C. to 150° C. for 2 minutes to 3 minutes. 15 . The method for making a removable adhesive tape according to claim 10 , wherein the first platinum-cured silicone adhesive and the second platinum-cured silicone adhesive comprise different platinum-cured adhesive base materials.

16. The method of making a removable tape according to claim 10, wherein the first platinum-cured silicone adhesive and the second platinum-cured silicone adhesive comprise the same platinum-cured adhesive base material.

17. The method for making a removable tape according to claim 15, further comprising mixing a first amount of a crosslinker mixture with the first platinum-cured silicone adhesive base material and mixing a second amount of a crosslinker mixture with the second platinum-cured silicone adhesive base material, and further, wherein the second amount of the crosslinker mixture is greater than the first amount of the crosslinker mixture.

18. A method of improving the sealing of a nozzle plate for an ejection head attached to a fluid ejection cartridge, the method of improving the sealing of a nozzle plate comprising: Providing a box body, the box body having: a cover closing a first end of the box body, the injection head located at a second end of the box body opposite to the first end, and a side wall attached to the first end and the second end between the first end and the second end; A removable tape is adhered to the nozzle plate of the ejector head and to one of the side walls, wherein the removable tape comprises a backing film and a modified platinum-cured silicone adhesive layer, the modified platinum-cured silicone adhesive layer having a first bonding strength adjacent to the backing film and a second bonding strength adjacent to the nozzle plate that is less than the first bonding strength.

19. A method for improving the sealing of a nozzle plate according to claim 18, wherein the first bonding strength has a peel strength ranging from 150 N / m to 500 N / m on a dry silicon wafer, and the second bonding strength has a peel strength ranging from 25 N / m to 65 N / m on a dry silicon wafer.

20. The method of improving the sealing of a nozzle plate according to claim 18, wherein the modified platinum-cured silicone adhesive layer has a thickness on the backing film ranging from 20 microns to 30 microns.

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