JPH10217484A - Formation of ink repellent layer and ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an ink repellent layer having high formation strength with respect to a member to be formed. SOLUTION: An ink repellent layer 320 is formed on the nozzle plate 303 of a printer head in an ink jet printer. The method for forming an ink repellent layer 320 having in intermediate layer and an uppermost ink repellent layer comprises a first step for forming the intermediate layer containing a material having high affinity to both the nozzle plate 303 and the ink repellent layer on the surface of the nozzle plate 303 through plasma polymerization, and a second step for forming the uppermost layer containing a material having low affinity to the nozzle plate on the intermediate layer through plasma polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-repellent layer forming method for forming an ink-repellent layer on a surface of a member which is in contact with ink, and an ink jet head using the same.

[0002]

2. Description of the Related Art Heretofore, there has been an ink jet printer using a piezoelectric element as a print head. In such a printer head, a predetermined space (ink channel) formed by the piezoelectric element and the nozzle plate due to the distortion of the piezoelectric element driven by the application of a voltage.
The ink inside is pressurized. The pressurized ink forms ink drops from the nozzles provided on the nozzle plate and flies toward the recording sheet, thereby forming an image on the recording sheet.

A small amount of ink may unnecessarily flow out of the periphery of the nozzle of the nozzle plate from which the ink is flying before and after the ink drop is made to fly. The spilled ink forms an ink puddle on the periphery of the nozzle, causing the size of the ink drop to fluctuate,
It changes the flight direction of the ink drop.

[0004] In order to prevent the formation of ink pools at the peripheral portion of the nozzle, there is known a technique for forming a liquid-repellent layer at the peripheral portion of the nozzle as disclosed in Japanese Patent Publication No. 3-43065. In the ink jet recording head disclosed in Japanese Patent Publication No. 3-43065, the composition of R.Si.X3 (R; a fluoroalkyl group, a fluoroaryl group, a fluorocycloalkyl group and a fluoroalkylaryl group A group having 2 to 12 carbon atoms selected,
X; a liquid-repellent layer comprising a hydrolyzable group having 1 or 2 carbon atoms selected from an alkoxy group and an acyloxy group, a halogen group or an alkyl group) is formed.

[0005]

However, such a liquid-repellent layer is formed by immersing a nozzle plate formed in advance in a liquid-repellent agent, and the liquid-repellent agent attached to the nozzle plate surface is thermally cured by the immersion. Therefore, the nozzle holes may be narrowed and clogged depending on the thickness of the liquid-repellent layer, and the sizes of the plurality of nozzle holes provided in one recording head are not uniform. This non-uniform size of the nozzle holes greatly affects the printing of small-diameter dots, in particular, and causes a significant reduction in image quality.

As described above, there is a problem in the method of forming a liquid-repellent layer by using a liquid phase, and a method of forming a liquid-repellent layer by using a gaseous phase, which does not cause narrowing and clogging of nozzle holes, has been considered. However, the formation strength of the liquid-repellent layer is not sufficient.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a method for forming an ink-repellent layer having a high forming strength with a member to be formed.

[0008]

The invention described in claim 1 is an ink-repellent layer forming method for forming an ink-repellent layer for repelling ink on a surface of a member in contact with the ink.

The ink-repellent layer forming method includes a first step of forming an intermediate layer containing a material having a high affinity for both the member and the surface layer on the surface of the member, and an ink-repelling method containing a material having a low affinity for the member. A second step of forming a neutral surface layer on the surface of the intermediate layer formed by the first step.

According to the first aspect of the present invention, the ink-repellent surface layer containing a material having low affinity with the member is provided via an intermediate layer containing a material having high affinity with both the member and the surface layer.
Glued to the surface of the member. Accordingly, it is possible to provide a method for forming an ink-repellent layer having high formation strength with a member to be formed.

According to the second aspect of the present invention, an ink-repellent layer is provided around an nozzle for discharging ink via an intermediate layer, and the intermediate layer is formed of a material having an affinity for the nozzle and the ink-repellent layer. An ink jet head characterized in that:

According to the second aspect of the present invention, the ink-repellent layer around the nozzle is provided with an intermediate layer interposed therebetween, and the intermediate layer is formed of a material having an affinity for the nozzle and the ink-repellent layer. . Accordingly, it is possible to provide an ink jet head having an ink-repellent layer having high formation strength with a member to be formed.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A printer head of an ink-jet printer having an ink-repellent layer by an ink-repellent layer forming method according to one embodiment of the present invention will be described, and then, an ink-repellent layer forming method according to the present invention will be described.

FIG. 1 is a perspective view showing a schematic configuration of an ink jet printer 1 having an ink repellent layer according to the present invention in an ink jet head 3.

[0015] The ink jet printer 1 uses paper or OH.
A recording sheet 2 that is a recording medium such as a P sheet, an inkjet head 3 that is an inkjet printer head, a carriage 4 that holds the inkjet head 3, and the carriage 4 is reciprocated in parallel with the recording surface of the recording sheet 2. Shafts 5 and 6 for driving, a drive motor 7 for reciprocatingly driving the carriage 4 along the swing shafts 5 and 6,
A timing belt 9 for changing the rotation of the drive motor 7 into a reciprocating motion of the carriage and an idle pulley 8 are included.

The ink jet printer 1 has a platen 10 also serving as a guide plate for guiding the recording sheet 2 along the transport path, a paper pressing plate 11 for pressing the recording sheet 2 between the platen 10 and preventing floating. Recording sheet 2
Roller 12, spur roller 13 for discharging
It includes a recovery system 14 for recovering the ink ejection failure of the inkjet head 3 to a satisfactory state, and a paper feed knob 15 for manually conveying the recording sheet 2.

The recording sheet 2 is fed to a recording section where the ink jet head 3 and the platen 10 face each other by a paper feeding device such as a manual feed or a cut sheet feeder. At this time, the rotation amount of a paper feed roller (not shown) is controlled, and the conveyance to the recording unit is controlled.

The ink jet head 3 uses PZT which is a piezoelectric element as an energy source for flying ink. A voltage is applied to PZT, causing distortion. This distortion changes the volume of the channel filled with ink. Due to this change in volume, ink is ejected from nozzles provided in the channel, and recording on the recording sheet 2 is performed. Here, the nozzle is provided on the nozzle plate, and the method of forming the ink-repellent layer on the nozzle plate is according to the present invention, which will be described in detail later.

The carriage 4 is driven by the drive motor 7, idle pulley 8, and timing belt 9 in the main scanning direction of the recording sheet 2, which is a direction crossing the recording sheet 2. Record the image for the line. Each time recording of one line is completed, the recording sheet 2 is fed in the vertical direction and sub-scanned, and the next line is recorded.

The image is recorded on the recording sheet 2 in this manner, and the recording sheet 2 that has passed through the recording section is discharged by a discharge roller 12 disposed downstream of the conveyance direction and a spur roller 13 pressed against the discharge roller 12. Is done.

FIGS. 2 to 4 are views for explaining the configuration of the ink jet head 3. FIG. FIG. 2 is a top view of the inkjet head 3, and FIG.
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3.

The ink jet head 3 has a large diameter head 301 and a small diameter head 302. The large-diameter head portion 301 and the small-diameter head portion 302 have a configuration in which a nozzle plate 303, a partition wall 304, a vibration plate 305, and a substrate 306 are integrally stacked. Among the ink drops having a plurality of dot diameters, an ink drop having a large dot diameter is ejected from the large diameter head section 301, and
2 ejects an ink drop having a small dot diameter.

The nozzle plate 303 is made of metal, ceramic, or the like, and has a surface 320 having an ion-repellent layer. Each of the large-diameter head section 301 and the small-diameter head section 302 has a plurality of ink channels 308 for accommodating ink 307 and each of the ink channels 308 is connected to the ink supply chamber 3.
An ink inlet 311 connected to the ink inlet 10 is formed.

As shown in FIG. 3, the ink channels 308 of the large-diameter head portion 301 and the small-diameter head portion 302 have a long groove shape extending in the direction in which the large-diameter head portion 301 and the small-diameter head portion 302 face each other. They are formed in parallel. In addition, the ink supply chamber 310 and the ink channel 30
8 is formed symmetrically with respect to the center line 312,
It is connected to an ink tank (not shown).

A thin film is used for the partition wall 304, and is fixed between the nozzle plate 303 and the diaphragm 305. The partition 304 is fixed in a state where a predetermined tension is applied.

The diaphragm 305 includes the PZT 315. The processing of the vibration plate 305 is performed by first fixing to the substrate 306 with an insulating adhesive, and then forming and separating the separate grooves 318 and 319 by dicer processing. In addition, by this division, the PZT 315 corresponding to each ink channel 308 and the adjacent PZT 3
15 and a peripheral wall 317 surrounding the PZT pillars 316 are separated from each other.

In the ink jet head 3 configured as described above, the ink supply chamber 31 is moved from an ink tank (not shown).
0 is supplied with ink 307. The ink 307 in the ink supply chamber 310 is distributed to each ink channel 308 via the ink inlet 311.

The operation of the ink jet head 3 is controlled by the control unit of the ink jet printer 1. A predetermined voltage, which is a print signal, is applied between the common electrode and the individual electrodes provided at both ends of the PZT 315 from the control unit, and the PZT 315 is deformed in a direction to push the partition 304. The deformation of the PZT 315 is the partition 304
, The ink 307 in the ink channel 308 is pressurized, and the ink drop flies toward the recording sheet 2 via the nozzle 309.

In this embodiment, an ink jet head having a large diameter nozzle and a small diameter nozzle has been described, but the diameter of the nozzle may be the same. When applying the present invention to an ink-jet head, performing gradation printing by controlling the dot diameter having the same size nozzle as the nozzle diameter,
Since it is particularly important to accurately control the dot diameter and to prevent variations in the dot diameter, the following ink-repellent layer forming method is effective.

The method of forming the ink-repellent layer on the nozzle plate will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the nozzle plate 303 for explaining the ink-repellent layer forming method according to the present invention. FIG. 5A is a view showing the nozzle plate 303 before the ink repellent layer is formed.
FIG. 5B is a view showing the nozzle plate 303 on which the intermediate layer is formed by the first step described below, and FIG. 5C is a nozzle having the outermost layer formed on the intermediate layer by the second step. FIG. 4 is a view showing a plate 303.

As described above, the ink-repellent layer 320 is formed on the nozzle plate 303. The ink repellent layer 320 includes an intermediate layer and an outermost layer having ink repellency, and the method of forming the ink repellent layer includes the following two steps. (1) An intermediate layer containing a material having a high affinity for both the nozzle plate and the outermost layer is formed by known plasma polymerization (plasma CVD in a broad sense).
A first step of forming on the surface of the nozzle plate.
(2) A step of forming an ink-repellent outermost layer containing a material having low affinity with the nozzle plate on the surface of the intermediate layer by known plasma polymerization.

In these plasma polymerizations, Si: H and C: H are used as source gases when forming the intermediate layer, and F: H and C: H are used as source gases when forming the outermost layer.

FIG. 6 is a diagram for explaining the effect of the ink-repellent layer formed on the nozzle plate 100. FIG.

A nozzle made of nickel or polyimide as shown, having a nozzle diameter as shown, a maximum fluorine content (atomic ratio), and a film thickness comprising an intermediate layer and an outermost layer. The adhesiveness, durability, and ink repellency shown in the evaluation items are evaluated for the plates a, b, c, and d. Here, the adhesiveness was measured by a tape peeling test according to JIS K5400 6.15, the durability was measured by a straightness test of an ink drop after wiping a rubber blade 60,000 times, and the ink repellency was measured by DIC MAT-1002BL. The evaluation is performed by measuring the contact angle of the ink using the ink. Here, as a comparative example, an evaluation of the nozzle plate e having no intermediate layer is shown.

In the nozzle plates a, b, and d, a-SiC: H is formed in the intermediate layer and a-CF: H is formed in the outermost layer as described above. In the nozzle plate c, as in other nozzle plates, a-SiC: H is formed in the intermediate layer and a-CF: H is formed in the outermost layer. When forming each of these layers, the composition of the source gas is changed. Go.

FIG. 7 is a diagram showing a change in the composition of the source gas when an ink-repellent layer is formed on the nozzle plate c.

When starting film formation on the surface of the nozzle plate, the Si content is set to 80 atm% (atomic ratio).
This Si is gradually reduced as the film is formed, and the content of Si is set to 30 atm% on the surface of the intermediate layer. The outermost layer is formed on the intermediate layer. When the film formation of the outermost layer is started, the F content is set to 0, and the F content is gradually increased as the film is formed. 30% content
tm%.

Referring again to FIG. 6, the evaluation results will be examined.
As for the adhesiveness, all of the nozzle plates a, c, and d show good results, and it can be said that the ink-repellent layer is firmly adhered. Peeling was observed at a part of the edge portion of the nozzle plate b, but this was not a problem in practical use. With respect to the nozzle plate e, peeling was observed around the nozzles, and reached a level that hindered practical use.

Regarding the durability, the nozzle plate a,
Both c and d show good results. No good results can be said for the nozzle plates b and e, but they have not yet reached a practically problematic level. The straightness of the ink drop is evaluated by measuring the displacement of the flying position of the ink drop from the nozzle to the recording sheet (Super Fine Paper manufactured by Epson Corporation) after wiping the rubber blade. For the nozzle plates a, b, c, d, and e, the flying positions of the ink drops were within ± 10 μm, within ± 20 μm, within ± 5 μm, within ± 10 μm, and within ± 20 μm, respectively.

Regarding the ink repellency, the contact angle becomes smaller in the order of nozzle plates c, be, e, a, and d.
The result was decreasing in this order.

With reference to these results, in particular, a nozzle plate a having an ink-repellent layer and having the conditions shown in FIG.
Each of c and d has high adhesiveness, durability, and ink repellency, and it can be seen that the adhesiveness, durability, and ink repellency of the nozzle plate b have reached practically acceptable levels. Also, with reference to these results, it is confirmed that the nozzle plate e given as a comparative example has a particularly low level of adhesiveness that causes practical problems.

As described above, by forming an intermediate layer having a high affinity for both the member and the outermost layer before forming the outermost layer which is the ink-repellent layer, a method for forming an ink-repellent layer having a high formation strength with the member to be formed is provided. And an ink jet head using the same.

In the above description, during plasma polymerization, a gas containing Si was used as a source gas so that the affinity with both the nozzle plate and the outermost layer was increased when the layer was formed.
It is also possible to use a gas containing n, As, St, or a metal of Group 4A.

In the above description, a gas containing F is used as a source gas during plasma polymerization so that the ink repellency is increased when a layer is formed. However, a gas containing another halogen may be used. It is possible.

In the present embodiment, the intermediate layer and the outermost layer were clearly separated during the plasma polymerization, but these were not separated, and each gas for forming the intermediate layer was formed at the start of film formation. It is also possible to set the composition and the ratio of the same and gradually change it as a grating layer while changing the gas flow rate and the kind as the film is formed, thereby making the outermost surface water-repellent.

By not clearly separating the outermost layer and the intermediate layer from each other, an ink-repellent layer having higher formation strength can be formed.

Further, in the embodiment of the present invention, the nozzle plate of the printer head of the ink jet printer has been described, but the present invention is naturally applied to a plate cylinder, a blanket cylinder, and the like used in an ink transfer process. It is also possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an ink jet printer 1 having an ink repellent layer according to the present invention in an ink jet head 3. FIG.

FIG. 2 is a top view for explaining the configuration of the inkjet head 3. FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a cross-sectional view of a nozzle plate 303 for explaining an ink-repellent layer forming method according to the present invention.

FIG. 6 is a diagram for explaining the effect of the ink-repellent layer formed on the nozzle plate 100.

7 is a diagram showing a change in composition of a source gas when an ink-repellent layer is formed on a nozzle plate c shown in FIG.

[Explanation of symbols]

 303 nozzle plate 309 nozzle 320 ink-repellent layer

Claims (2)

[Claims] 1. A method for forming an ink-repellent layer, wherein an ink-repellent layer for repelling ink is formed on a surface of a member in contact with ink, wherein an intermediate layer containing a material having high affinity with both the member and the surface layer is formed on the member. A first step of forming on the surface; and a second step of forming the ink-repellent surface layer containing a material having low affinity with the member on the intermediate layer formed in the first step. And a method for forming an ink-repellent layer. 2. An ink-repellent layer is provided around an nozzle for discharging ink via an intermediate layer, and the intermediate layer is formed of a material having an affinity for the nozzle and the ink-repellent layer. Inkjet head.