JP4920334B2 - Manufacturing method of color filter - Google Patents

Description

  The present invention relates to a method for manufacturing a color filter.

A method of creating a color filter by an ink jet method is disclosed (for example, see Patent Document 1 or 2). In carrying out this method, as a method for reducing the error of the ink landing position, a method of detecting the mask position and correcting the position (see, for example, Patent Document 3), the landing position is detected and the droplet ejection timing is corrected. A method (for example, see Patent Document 4), a method for determining a landing pitch according to ink droplet amount variation for each nozzle (for example, see Patent Document 5), and a method for appropriately setting a droplet landing diameter (for example, Patent Document 6) and the like are disclosed. In addition, a method (for example, refer to Patent Document 7) in which droplets are ejected by using a plurality of different nozzles while shifting the position in the pixel has been proposed. Further, a method for optimizing the landing pitch and the droplet diameter (for example, see Patent Document 8) has been proposed, and it is disclosed to optimize the droplet diameter in order to reduce the droplet trace caused by the overlapping of the landing droplets. ing.
JP 59-75205 A JP-A-6-347637 JP-A-8-82707 JP-A-8-292319 Japanese Patent Laid-Open No. 11-52118 JP-A-11-190804 JP-A-9-281324 JP 2004-290961 A

FIG. 1 is a diagram for explaining a change in the landing shape of ink droplets when a plurality of ink droplets are dropped.
In a method in which ink droplets are sequentially dropped into the inside of a droplet ejection area divided by a partition like a color filter, the ink droplets that have landed first spread over the substrate with time (FIG. 1A). When the succeeding droplets land in the spread area before the ink that has landed earlier (FIG. 1B), the ink droplets coalesce on the substrate, and the force that minimizes the surface area by the surface tension works. In this case, since a phenomenon in which subsequent landing droplets are attracted to the preceding landing droplet side occurs, the ink distribution in the region changes from the average position of each droplet to the preceding landing side (FIG. 1C), and the portion where the ink distribution is thin Or the part where ink does not spread occurs. As a result, the density becomes uneven and the density is lowered, and the performance of the color filter is lowered.
As described above, it is difficult to distribute at desired positions only by ejecting droplets at equal intervals.

Patent Documents 1 to 7 described above are countermeasures against variations in the transport position and landing position due to the transport device and the discharge device, and are not effective in changing the ink shape due to coalescence of ink droplets. No method or effect is disclosed.
Further, Patent Document 8 discloses that the droplet diameter is optimized in order to reduce the drop mark due to the overlap of the landing droplets. However, the change in the ink distribution due to the properties of the combined droplets described in the above problem is disclosed. Does not produce any effect.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a color filter manufacturing method capable of making the ink distribution uniform in the droplet ejection region.

That is, the present invention
<1> A plurality of ink droplets having the same diameter in the droplet ejection region by relatively scanning a substrate in which a plurality of droplet ejection regions are partitioned by a partition and an inkjet head having at least one nozzle hole. A method for producing a color filter having a step of ejecting droplets from the nozzle hole, wherein at least one droplet ejection interval in the droplet ejection region is larger than twice the ink droplet diameter, and at least one droplet ejection is performed. The color filter manufacturing method is characterized in that the interval is smaller than twice the ink droplet diameter.

  <2> The color filter manufacturing method according to <1>, wherein each of the droplet ejection regions is ejected from the same nozzle hole.

< 3 > The method for producing a color filter according to <1> or <2> , wherein a contact angle between the ink and the substrate at a substrate temperature is 5 degrees or more and 25 degrees or less.

< 4 > The method for producing a color filter according to any one of <1> to < 3 >, wherein a surface tension of the ink at a substrate temperature is 15 mN / m or more and 40 mN / m or less.

< 5 > The method for producing a color filter according to any one of <1> to < 4 >, wherein the viscosity of the ink at a substrate temperature is 20 mPa · s or less.

  According to the present invention, there is provided a method for manufacturing a color filter capable of making the ink distribution uniform in the droplet ejection region.

  Hereinafter, the manufacturing method of the color filter of this invention is demonstrated in detail. In the color filter manufacturing method of the present invention, a substrate in which a plurality of droplet ejection areas are divided by a partition and an ink jet head having at least one nozzle hole are relatively scanned to cause ink to enter the droplet ejection area. The step of ejecting from the nozzle hole as a plurality of ink droplets (ink droplet ejection step) is defined, and the ink ejected in the droplet ejection region is dried and cured as necessary to perform the ink ejection. Pixels corresponding to the shape of the droplet region are formed. First, the ink droplet ejection process, which is a feature of the present invention, will be described in detail.

<First Color Filter Manufacturing Method>
According to the first color filter manufacturing method of the present invention, a droplet is ejected by relatively scanning a substrate in which a plurality of droplet ejection regions are partitioned by a partition and an inkjet head having at least one nozzle hole. A method of manufacturing a color filter having a step of ejecting droplets from the nozzle hole as a plurality of ink droplets in a region, wherein a droplet ejection interval in at least one location in the droplet ejection region is larger than twice the ink droplet diameter. The at least one droplet ejection interval is smaller than twice the ink droplet diameter.

  Here, in the present invention, the “droplet ejection interval” is the distance between the target landing position of one ink droplet and the target landing position of another ink droplet positioned in the scanning direction of the target landing position of the one ink droplet. The distance.

  Here, the target landing position means (the position of the head relative to the substrate at the moment of droplet ejection) + scanning speed × (discharge direction distance from nozzle to substrate / droplet ejection speed).

In the present invention, the “ink droplet diameter” refers to a value measured by the following method.
A means for illuminating the ink droplets sequentially ejected from the nozzle at a timing delayed by a predetermined time from the ejection energy application timing, specifically, a strobe light or a light emitting diode (LED) is energized for a short time, and this is applied to a microscope. When the image is taken with a camera or the like attached to the lens, the droplets discharged from the nozzle can be observed as a still image. The diameter of the drop is measured from this image.

  In the first color filter manufacturing method, since the droplet ejection interval at at least one location (interval A) in the droplet ejection region is larger than twice the diameter of the ink droplet, the occurrence of ink droplet coalescence is prevented at this location. be able to. As a result, it is possible to control the movement of the ink due to coalescence, and the ink distribution in the droplet ejection area can be made uniform. As a result, pixel density unevenness can be reduced and pixel density reduction can be prevented.

  The droplet ejection interval of the interval A is preferably less than or equal to one half of the length of the droplet ejection region in the scanning direction. If the distance A is too large, adjacent landings are not connected to each other, and the uniformity is greatly impaired. In order to obtain a uniform distribution, one-half or less of the length in the scanning direction of the droplet ejection area is suitable. If it is larger than this, an area where the amount of ink is small or an area where the ink is not wet occurs.

  Further, in the first color filter manufacturing method, at least one droplet ejection interval (interval B) in the droplet ejection region is smaller than twice the ink droplet diameter, but the droplet ejection interval of the interval B is an ink droplet. It is preferably at least 1 / 100th of the droplet diameter. If the ink droplet spacing is smaller than one-hundred of the ink droplet diameter, it is necessary to deposit many ink droplets in order to deposit a predetermined area. Therefore, productivity will be reduced.

  In order to make at least one droplet ejection interval in the droplet ejection area larger than twice the ink droplet diameter and make at least one droplet ejection interval smaller than twice the ink droplet diameter, the landing position of the ink droplet is set. It is only necessary to appropriately control the ejection timing or scanning speed of the ink droplets so that the intervals are not uniform within the pixel, and such control can be easily performed by those skilled in the art.

  In the first color filter manufacturing method, it is preferable that each of the droplet ejection regions is ejected from the same nozzle hole. By applying droplets from the same nozzle, the time interval between the preceding and subsequent droplets can be reduced, and the subsequent droplets land before the preceding landing droplets dry. Uniform uniformity can be obtained. In order to perform droplet ejection using different nozzles, it is necessary to scan the droplet ejection again after moving the distance necessary to change the nozzle in a direction substantially perpendicular to the scanning direction of the nozzle and the substrate during droplet ejection, It takes time to stop and start the droplet ejection scan and move in the direction of the nozzle row, not only reducing productivity, but also drying the preceding droplet during the time to switch nozzles, Becomes a filter with poor uniformity.

<Method for producing second color filter>
According to the second color filter manufacturing method of the present invention, the ink droplets are ejected by relatively scanning a substrate in which a plurality of droplet ejection regions are divided by a partition and an inkjet head having at least one nozzle hole. A method of manufacturing a color filter having a step of ejecting ink droplets from the nozzle holes as a plurality of ink droplets in the region, wherein each of the droplet ejection regions is the same nozzle hole from the upstream side to the downstream side in the scanning direction. The droplets are sequentially ejected, and the distance between the first target landing position in the droplet ejection area and the partition wall upstream in the scanning direction is larger than the distance between the last target landing position and the partition wall downstream in the scanning direction. It is.

  In the second color filter manufacturing method, ink droplets are sequentially ejected onto the droplet ejection region from the upstream side to the downstream side in the scanning direction. That is, in the present invention, the “first target landing position” refers to a target landing position that is located on the most upstream side with respect to the scanning direction in one droplet ejection region. Further, the “last target landing position” refers to a target landing position that is located on the most downstream side in the scanning direction in one droplet ejection area.

  In the second color filter manufacturing method, the distance between the first target landing position and the partition upstream in the scanning direction is larger than the distance between the last target landing position and the partition downstream in the scanning direction. Even if the landing shape of the ink after the unification is closer to the upstream side in the scanning direction, poor wetting on the downstream side can be prevented, and the ink distribution in the droplet ejection area can be made uniform. As a result, pixel density unevenness can be reduced and pixel density reduction can be prevented.

In the second color filter manufacturing method, the scanning direction is the longitudinal direction of the droplet ejection region, the distance between the first target landing position and the partition upstream in the scanning direction is greater than the diameter of the ink droplets and It is smaller than the width in the short direction of the droplet ejection area, the distance between the last target landing position and the partition wall downstream in the scanning direction is larger than the radius of the ink droplet, and is 1 of the width in the short direction of the droplet ejection area. It is preferably smaller than / 2.
As a result, it is possible to further reduce pixel density unevenness and to more effectively prevent pixel density reduction.

Here, the manufacturing method of a 2nd color filter is demonstrated using drawing. FIG. 2 is a diagram for explaining a method of manufacturing the second color filter. A substantially rectangular droplet ejection region 20 is divided on the substrate by the partition wall 10. In the droplet ejection region 20, the scanning direction is the longitudinal direction, and the direction perpendicular to the scanning direction is the short direction. The target landing position 30 is indicated by a black dot in the figure. The first distance between the target landing position 30 ₁ and the scanning direction upstream of the partition wall 10A which is located on the most upstream side with respect to the scanning direction is defined in the figure P. Further, the distance between the last target landing position 30 _n located on the most downstream side in the scanning direction and the partition wall 10B downstream in the scanning direction is defined by Q in the drawing.

<Method for producing third color filter>
According to a third color filter manufacturing method of the present invention, a substrate in which a plurality of droplet ejection regions are divided by a partition and an inkjet head having at least one nozzle hole are relatively scanned to cause ink to eject the droplets. A method of manufacturing a color filter having a step of ejecting droplets from the nozzle hole as a plurality of ink droplets in a region, wherein a distance from a partition wall upstream in the first scanning direction in the droplet ejection region is a distance between the ink droplets. A position that is larger than the diameter and smaller than the width of the droplet ejection area in the short direction is a first initial target landing position, and a distance from a partition wall upstream in the second scanning direction opposite to the first scanning direction. Is a position where the diameter is larger than the diameter of the ink droplet and smaller than the width in the short direction of the droplet ejection area as a second first target landing position, and the distance from the partition wall upstream in the second scanning direction is the ink droplet diameter. Than twice When a predetermined threshold position is set as the first final target landing position, ink droplets are sequentially ejected from the first first target landing position to the first final target landing position in the first scanning direction. After that, the ink droplets are sequentially ejected from the second first target landing position to the second final target landing position in the second scanning direction.

In the third color filter manufacturing method, the partition between the first scanning direction upstream partition and the first first target landing position and the second scanning direction upstream partition and the second first target landing position By setting a predetermined interval between the ink droplets, it is possible to avoid the ink droplets climbing onto the partition walls and color mixing with adjacent pixels.
In addition, after droplets have been ejected from the first initial target landing position to the first final target landing position in the first scanning direction, the second final target from the second initial target landing position in the second scanning direction. By ejecting droplets to the target landing position, a portion for reducing the influence of ink droplet coalescence can be provided between the first final target landing position and the second final target landing position. For this reason, it is possible to maintain good wetting at both ends of the pixel, reduce pixel density unevenness, and prevent pixel density reduction.

  In the third color filter manufacturing method, the lower limit of the distance between the partition wall on the upstream side in the second scanning direction and the first final target landing position needs to be larger than twice the ink droplet diameter. The upper limit is preferably smaller than the width of the droplet ejection area in the short direction. The second final target landing position may be located upstream of the first final target landing position in the second scanning direction, and the first final target landing position and the second final target landing position may be located. The distance from the landing position is preferably smaller than twice the diameter of the ink droplet.

Here, a third color filter manufacturing method will be described with reference to the drawings. FIG. 3 is a diagram for explaining a third color filter manufacturing method. A substantially rectangular droplet ejection region 20 is divided on the substrate by the partition wall 10. In the droplet ejection region 20, the scanning direction is the longitudinal direction, and the direction perpendicular to the scanning direction is the short direction. The target landing positions 30 and 32 are indicated by black dots in the figure. The most upstream side with respect to the distance and the second scanning direction between a first initial target landing position 30 ₁ first scanning direction upstream of the partition wall 10A which is located on the most upstream side with respect to the first scanning direction the distance between the second initial target landing position 32 ₁ and the second scanning direction upstream of the partition wall 10B is located is defined in each view P and Q. In addition, the distance between the first final target landing position 30 _n and the second partition 10B upstream in the scanning direction is defined by R in the figure. Furthermore, the distance between the first final target landing position 30 _n and the second final target landing position 32 _n is defined by S in the figure.

<Fourth color filter manufacturing method>
According to a fourth color filter manufacturing method of the present invention, a substrate in which a plurality of droplet ejection regions are divided by a partition and an inkjet head having at least one nozzle hole are relatively scanned to cause ink to eject the droplets. A method of manufacturing a color filter having a step of ejecting ink droplets from the nozzle holes as a plurality of ink droplets in the region, wherein each of the droplet ejection regions is the same nozzle hole from the upstream side to the downstream side in the scanning direction. The droplets are sequentially ejected, and the total droplet ejection amount in the upper half of the scanning direction in the droplet ejection region is smaller than the total droplet ejection amount in the lower half region in the scanning direction. It is characterized by this.

  Here, the “target droplet ejection amount” refers to an amount obtained by multiplying the volume of one ink droplet obtained from the diameter of the droplet measured by the measurement method by the number of droplet ejection.

  Ink droplets are sequentially ejected from the upstream side in the scanning direction to the downstream side of the droplet ejection region so that the sum of the target droplet ejection amounts on the upstream side in the scanning direction is equal to the sum of the target droplet ejection amounts on the downstream side. In this case, since the ink droplets are united, the amount of ink after landing is likely to be distributed more on the upstream side in the scanning direction. In the fourth color filter manufacturing method, the total target droplet ejection amount in the half area on the upstream side in the scanning direction is smaller than the total droplet ejection amount in the half area on the downstream side in the scanning direction. In order to achieve this, that is, to eject more ink droplets on the downstream side, it is possible to make the ink distribution uniform after the ink droplets have been combined. Therefore, it is possible to reduce pixel density unevenness and prevent pixel density reduction.

  The difference between the total target droplet ejection amount on the upstream side and the total target droplet ejection amount on the downstream side is preferably 1/10 to 1/2 of the total target droplet ejection amount in the droplet ejection region, and 1/8 to 1/4. Is more preferable.

  The first to fourth color filter manufacturing methods described above are particularly effective when ink droplets are ejected onto a droplet ejection region that is divided into substantially rectangular shapes by a partition wall.

  Next, other requirements other than the ink droplet ejection process according to the color filter manufacturing method of the present invention will be described.

<Inkjet head>
As the ink jet head (hereinafter also simply referred to as a head), a known one can be applied, and a continuous type or a dot on demand type can be used. Among the dot-on-demand types, for the piezo head, for example, the heads described in European Patent A277,703, European Patent A278,590 and the like can be used. Among these, the piezo head is more preferable because the influence of heat on the ink can be reduced and the selection of usable organic solvents is wide. The head preferably has a temperature control function so that the temperature of the ink can be controlled. It is preferable to set the injection temperature so that the viscosity at the time of ejection is 5 to 25 mPa · s, and to control the ink temperature so that the fluctuation range of the viscosity is within ± 5%. Further, the drive frequency is preferably 1 to 500 kHz. The shape of the nozzle hole does not necessarily need to be circular, and is not particular about the shape such as an ellipse or a rectangle. The nozzle diameter is preferably in the range of 10 to 100 μm. In addition, although the opening part itself of a nozzle hole is not necessarily a perfect circle in that case, the nozzle diameter assumes the circle | round | yen equivalent to the area of this opening part, and makes it the diameter.
The color filter in the present invention is preferably in the form of a group composed of pixels of three colors by spraying ink of RGB three colors.

As the ink ejection method, a method in which charged ink is continuously ejected and controlled by an electric field, a method in which ink is ejected intermittently using a piezoelectric element, and an ink is intermittently ejected by heating and foaming the ink. Various methods, such as a method to do, can be adopted.
As the ink ejection conditions, it is preferable from the viewpoint of ejection stability that the ink is heated to 30 to 60 ° C. and ejected with the ink viscosity lowered. Inks generally have higher viscosities than water-based inks, and thus the viscosity fluctuation range due to temperature fluctuations is large. It is important to keep the ink temperature as constant as possible, since the viscosity variation directly affects the droplet size and the droplet ejection speed and easily causes image quality degradation.

<Ink>
The ink used in the present invention (hereinafter sometimes referred to as “inkjet ink”) is not particularly limited, and is a solventless ink containing at least a monomer having a colorant and two or more polymerizable groups. It may be any of solvent-containing inks further containing an organic solvent.
The inkjet ink used in the present invention may further contain a dispersant, a binder, a photopolymerization initiator, a thermal polymerization initiator, a surfactant, or other additives.

Below, each component contained in an inkjet ink is described in detail.
(Coloring agent)
As the colorant used in the ink-jet ink, known pigments such as organic pigments, inorganic pigments, and dyes can be used, but sufficient transmission density, light resistance, adhesion to the substrate, and other resistances are required. Various organic pigments are suitable. Specific examples of the colorant include pigments and dyes described in JP-A-2005-17716 [0038] to [0054], pigments described in JP-A-2004-361447 [0068] to [0072] The colorants described in JP-A-2005-17521 [0080] to [0088] can be preferably used. Among these, pigments are particularly preferable from the viewpoint of storage stability of pixels.
The content of the colorant in the present invention is not particularly limited, but from the viewpoint of obtaining a desired hue and density, the proportion of the colorant in the remainder of the ink is preferably 20% by mass or more, and 20 to 70% by mass. Is more preferable, 25-60 mass% is more preferable, and 30-50 mass% is especially preferable.

In the present invention, the combination of the above-described pigments preferably used in combination is C.I. I. In pigment red 254, C.I. I. Pigment red 177, C.I. I. Pigment red 224, C.I. I. Pigment yellow 139 or C.I. I. A combination with Pigment Violet 23; I. In Pigment Green 36, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 138 or C.I. I. A combination with CI Pigment Yellow 180, and C.I. I. In Pigment Blue 15: 6, C.I. I. Pigment violet 23 or C.I. I. A combination with Pigment Blue 60 is mentioned.
C. in the pigment when used together in this way. I. Pigment red 254, C.I. I. Pigment green 36, C.I. I. The content of Pigment Blue 15: 6 is C.I. I. Pigment Red 254 is preferably 60% by mass or more, particularly preferably 70% by mass or more. C. I. The pigment green 36 is preferably 50% by mass or more, particularly preferably 60% by mass or more. C. I. Pigment Blue 15: 6 is preferably 80% by mass or more, and particularly preferably 90% by mass or more.

  The pigment used in the present invention preferably has a number average particle size of 0.001 to 0.1 μm, more preferably 0.01 to 0.08 μm. When the number average particle diameter of the pigment is less than 0.001 μm, the particle surface energy is increased and the particles are easily aggregated, so that it is difficult to disperse the pigment and it is difficult to keep the dispersion state stable. On the other hand, if the number average particle diameter of the pigment exceeds 0.1 μm, the polarization is canceled by the pigment, and the contrast is lowered. The “particle diameter” as used herein refers to the diameter when the electron micrograph image of the particle is a circle of the same area, and the “number average particle diameter” is the above-mentioned particle diameter for a number of particles, The average value of 100 is said.

  The pigment is desirably used as a dispersion. This dispersion can be prepared by dispersing a composition obtained by previously mixing the pigment, a pigment dispersant described later, and an organic solvent using a known disperser. At this time, a small amount of resin may be added in order to impart dispersion stability of the pigment. Moreover, it is also possible to prepare the composition obtained by mixing the pigment and the pigment dispersant in advance by adding to a monomer described later and dispersing it. The disperser used for dispersing the pigment is not particularly limited. For example, a kneader described in Kazuzo Asakura, “Encyclopedia of Pigments”, first edition, Asakura Shoten, 2000, page 438, Known dispersing machines such as a roll mill, an atrider, a super mill, a dissolver, a homomixer, and a sand mill can be used. Further, fine grinding may be performed using frictional force by mechanical grinding described on page 310 of the document.

(Pigment dispersant)
It is preferable to add a pigment dispersant to the inkjet ink in order to obtain the dispersion stability of the pigment.
The amount used is preferably 0.1 to 10% by mass, more preferably 0.1 to 9% by mass, and more preferably 0.1 to 8% by mass with respect to the total mass of the inkjet ink. A range is particularly preferred.
Examples of the pigment dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a salt of a long chain polyaminoamide and a polar acid ester, a high molecular weight unsaturated ester, Polymer copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, polyoxyethylene nonyl Phenyl ether, stearylamine acetate, pigment derivatives and the like can be used.

  As specific examples of the pigment dispersant, the examples described in paragraphs [0021] to [0023] of JP-A-2005-15672 can be used as preferred examples of the present invention.

(monomer)
The monomer having two or more polymerizable groups used in the inkjet ink of the present invention (hereinafter sometimes referred to as a bifunctional or higher monomer) is particularly limited as long as it can be polymerized by active energy rays and / or heat. Although not intended, a monomer having three or more polymerizable groups (hereinafter sometimes abbreviated as a tri- or higher functional monomer) is more preferable from the viewpoint of pixel strength, solvent resistance, and the like. The proportion of the tri- or higher functional monomer in the whole monomer is preferably 20% by mass or more, and more preferably 30% by mass or more. The tri- or higher functional monomer preferably has a viscosity at 25 ° C. of 700 mPa · s or less, and more preferably 200 mPa · s or less.

The type of the polymerizable group is not particularly limited, but the viscosity of the polymerizable monomer itself is increased by increasing the number of functional groups. Therefore, it is preferable that the viscosity of the functional group itself is low, such as an acryloyloxy group, a methacryloyloxy group, Epoxy groups are particularly preferred.
Specific examples of the tri- or higher functional polymerizable monomer include a trifunctional epoxy group-containing monomer described in paragraph Nos. 0061 to 0063 of JP-A No. 2001-350012 and paragraph No. 0016 of JP-A No. 2002-371216. And trifunctional or higher acrylate monomers, methacrylate monomers, and trifunctional or higher functional monomers described in “Market Prospects of Reactive Monomers” published by CMC Publishing Co., Ltd. Among these, trimethylolpropane triacrylate, trimethylolpropane PO (propylene oxide) modified triacrylate, trimethylolpropane EO (ethylene oxide) modified triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate are particularly preferable. Examples include, but are not limited to, methacrylate, pentaerythritol triacrylate, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. It is also possible to use two or more of the above trifunctional monomers.

  A monofunctional monomer or a bifunctional monomer may be used in combination as appropriate for the purpose of accelerating the polymerization reaction in the pixel portion. Examples of these monofunctional monomers and bifunctional monomers include monofunctional epoxy group-containing monomers described in paragraph No. [0065] of JP-A No. 2001-350012, and paragraph Nos. 0015 to of JP-A No. 2002-371216. And monofunctional or bifunctional acrylate monomers and methacrylate monomers described in 0016, and monofunctional or bifunctional monomers described in “Market Prospects of Reactive Monomers” published by CMC Publishing Co., Ltd.

  A small amount of high-functionality polyfunctional monomer with a viscosity of 700 mPa · s or more at 25 ° C, high-polarity monomer such as urethane acrylate, oligomer, etc. is used in combination to compensate for pixel strength or to provide close contact with the substrate. It doesn't matter. There are no particular restrictions on the polyfunctional monomer or highly polar monomer and oligomer preferred for use in combination, and general-purpose ones can be used. For example, dipentaerythritol hexaacrylate, isocyanuric acid EO-modified diacrylate, isocyanuric acid EO-modified Triacrylate, ε-caprolactone modified tris (acryloxyethyl) isocyanurate, urethane acrylate (for example, Allonics M-1000, M-1200, M-1210, M-1600 manufactured by Toa Gosei Co., Ltd.), polyester acrylate (for example, Toa Gosei) Allonics M-6100, M-6200, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, M -9050), etc. That. The amount of these combined monomers added can be adjusted as appropriate within the range where the viscosity of the remaining ink becomes 4000 mPa · s or less at 25 ° C.

  The amount of the monomer used is preferably 20% by mass or more, more preferably 30% by mass or more, and further preferably 40% by mass or more in the ink solid content. When the amount of the monomer used is less than 20% by mass, the polymerization of the pixel becomes insufficient, so that the strength of the pixel is insufficient and the surface is easily damaged, or reticulation occurs when a transparent conductive film is applied. Or the problem of insufficient solvent resistance at the time of providing the alignment film occurs.

(Organic solvent)
Examples of the organic solvent include water-soluble organic solvents such as alcohols and water-insoluble organic solvents such as esters and ethers. Water-insoluble organic solvents are preferred for the following reasons.
When the solvent is a water-soluble organic solvent, the binder or monomer to be used needs to be water-soluble. Since these water-soluble binders and monomers have polar groups, the viscosity of the remaining ink after removal of the water-soluble organic solvent tends to increase, and it becomes difficult to flatten the shape of the color filter pixel.
There are no particular restrictions on the water-insoluble organic solvent, but organic solvents that have a low boiling point and are easy to remove from the inkjet ink usually evaporate quickly on the inkjet head, making it easy to increase the viscosity of the ink on the head. In many cases, it is accompanied by deterioration of the discharge property. In order to prevent the ink from being dried in the ink jet head, it is preferable to include at least an organic solvent having a boiling point of 160 ° C. or higher at normal pressure.

  The proportion of these organic solvents in the inkjet ink is preferably 40% by mass or more, more preferably 50% by mass or more, and further preferably 60% by mass or more. When the proportion of the organic solvent is less than 40% by mass, the amount of ink ejected in the droplet ejection amount area is small, so that wetting and spreading of the ink in the droplet ejection area is insufficient, and the flatness deteriorates. May occur.

  Moreover, it is preferable that 50 mass% or more of the organic solvent to contain an inkjet ink is a compound which has a boiling point of 160 degreeC or more at 760 mmHg (101.3 kPa). Examples of the organic solvent having a boiling point of 160 ° C. or higher at room temperature include the high boiling point solvents, alkylene glycol acetate, and alkylene glycol diacetate described in JP-A-2000-310706 [0031] to [0037]. Propylene glycol monomethyl ether, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, propylene glycol-n-butyl ether acetate, dipropylene glycol mono-n-butyl ether, tripropylene glycol methyl ether acetate, diethylene glycol monobutyl ether, 1,3-butane Diol diacetate, dipropylene glycol-n-propyl ether acetate, propylene carbonate, diethylene glycol monobuty Ruether acetate, dipropylene glycol-n-butyl ether acetate and the like are particularly preferable.

  Further, the upper limit of the boiling point of the organic solvent is not particularly limited as long as the color filter can be produced by the inkjet method using the inkjet ink, but the operability in the ink preparation process and the color filter production process is not limited. From this point of view, an organic solvent having a boiling point of 290 ° C. or lower, preferably 280 ° C. or lower and a liquid having a relatively low viscosity at room temperature (20 ° C.) is desirable.

(Polymerization initiator)
In the inkjet ink, a polymerization initiator may be used in combination for the purpose of promoting the polymerization reaction of the monomer. As the polymerization initiator, a photopolymerization initiator is used when the pixel is polymerized by active energy rays, and a thermal polymerization initiator is used when the pixel is polymerized by heat. Examples of the photopolymerization initiator include those described in paragraphs [0079] to [0088] of JP-A-2006-28455, and preferred specific examples include 2-trichloromethyl-5- (p-styryl). Styryl) -1,3,4-oxadiazole and 2,4-bis (trichloromethyl) -6- [4 ′-(N, N-bisethoxycarbonylmethylamino) -3′-bromophenyl] -s -Triazines are mentioned.

  As the thermal polymerization initiator, generally known organic peroxide compounds and azo compounds can be used. Thereby, the strength of the pixel can be improved. In addition to the thermal polymerization initiator, a curing catalyst such as imidazole can also be used. The organic peroxide compound and the azo compound can be used in combination of two or more in addition to the single use. Here, the organic peroxide is a derivative of hydrogen peroxide (H—O—O—H) and refers to an organic compound having a —O—O— bond in the molecule.

  When classified by chemical structure, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, peroxydicarbonates and the like can be mentioned. Specifically, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, benzoyl peroxide, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, di-t-butylperoxybenzoate, di-t-butylperoxyisophthalate, t- Butyl peroxyacetate, t-hexyl peroxybenzoate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl Peroxy-2-ethylhexyl monocarbonate, 2,5-bis (m-toluyl peroxy Hexane, 2,5-dimethyl-2,5-bis (benzoyl peroxy) hexane, t-hexyl peroxy isopropyl monocarbonate,

t-butylperoxyisobutyrate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxyisopropylmonocarbonate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxymaleic acid, cyclohexanone peroxide, methyl acetoacetate peroxide, methylhexanone peroxide, acetylacetone peroxide Oxide, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis ( -Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, diisopropylbenzene hydroperoxide, 1, 1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like are preferable, such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane Peroxyketal compounds, diacyl peroxide compounds such as benzoyl peroxide, and peroxyester compounds such as t-butyl peroxybenzoate are preferred.

  Examples of the azo compound include compounds described in paragraphs [0021] to [0023] of JP-A-5-5014. Among these compounds, a compound that has a decomposition temperature that is somewhat high and is stable at room temperature, is a compound that decomposes when heated to generate radicals and serves as a polymerization initiator. Among organic peroxide compounds or azo compounds (thermal polymerization initiators), those having a relatively high half-life temperature (preferably 50 ° C. or higher, more preferably 80 ° C. or higher) are used. The viscosity can be suitably configured without changing with time, and examples thereof include azobis (cyclohexane-1-carbonitrile).

As content of a photoinitiator and / or a thermal-polymerization initiator, 0.5-20 mass% is preferable with respect to the quantity of a monomer, More preferably, it is 1-15 mass%. When the content of the polymerization initiator is less than 0.5% by mass with respect to the monomer, the effect may be reduced. When the content exceeds 20% by mass, the viscosity of the ink-jet ink may change over time or Coloring by objects may be a problem.
These initiators can be used alone or in combination of two or more.

  In addition to the polymerization initiator, a binder, a surfactant, and other additives may be used in combination. Examples of the binder to be used in combination include the binder resin described in paragraphs [0015] to [0030] of JP-A No. 2000-310706 and the paragraph numbers [0041] to [0050] of JP-A No. 2001-350012. And the like.

  As examples of the surfactant, the surfactants disclosed in JP-A-7-216276, paragraph [0021], JP-A-2003-337424, and JP-A-11-133600 are preferable. As mentioned. The content of the surfactant is preferably 5% by mass or less with respect to the total amount of the inkjet ink.

  Examples of other additives include other additives described in paragraph numbers [0058] to [0071] of JP-A No. 2000-310706.

  The wetting of the ink on the substrate is largely governed by the surface tension and viscosity of the ink at the substrate temperature and the contact angle between the glass substrate and the ink.

In the present invention, the surface tension of the ink at the substrate temperature is preferably 15 mN / m or more and 40 mN / m or less.
The lower the surface tension of the ink at the substrate temperature, the lighter the droplets are coalesced. However, when the ink is less than 15 mN / m, the ink becomes mist when it is ejected from the nozzle hole and becomes unstable when separated from the nozzle. May be scattered. On the other hand, if it exceeds 40 mN / m, the coalescence force between the landing droplets is strong, and good wetting may not be obtained.
The surface tension is more preferably 20 mN / m to 40 mN / m, particularly preferably 25 mN / m to 35 mN / m.

In the present invention, the viscosity of the ink at the substrate temperature is preferably 20 mPa · s or less. The lower the viscosity of the ink at the substrate temperature, the better the fluidity on the substrate and the better the wetting.
The viscosity greatly depends on the concentration of the pigment dispersion. By increasing the concentration, a high concentration filter can be obtained with a small amount of ink, but the viscosity increases. When the viscosity rises, it becomes difficult to discharge with the head. 20 mPa.s. If it is more than s, it may not be able to be ejected by the head.
The viscosity is 17 mPa.s. s or less, more preferably 15 mPa.s. Particularly preferred is s or less.

In the present invention, the contact angle between the ink and the substrate at the substrate temperature is preferably 5 degrees or more and 25 degrees or less.
The smaller the contact angle of the ink with the glass substrate at the glass substrate temperature, the larger the landing area on the substrate, and good wetting can be obtained. The contact angle can be measured by using the Drop Master 700 manufactured by Kyowa Interface Science, and the angle after 500 msec after the 3 μl ink droplet leaves the syringe can be measured by the θ / 2 method.
The contact angle is more preferably 5 to 20 degrees, and particularly preferably 5 to 15 degrees.

  The contact angle depends on the amount of surfactant added and the monomer type. Although it can be reduced by increasing the surfactant, the surface tension is also lowered when the addition amount is increased, and the above-mentioned problems occur. Therefore, it may be difficult to make it less than 5 degrees. On the other hand, if the angle exceeds 25 degrees, the landing droplets do not spread on the glass substrate and good wetting may not be obtained.

  The above-described surface tension, viscosity, and contact angle range between the glass substrate and the ink can be achieved by appropriately selecting the components in the ink.

  In the present invention, a step of irradiating active ink rays to the ejected ink (hereinafter sometimes referred to as a photopolymerization step) and / or a step of heating (hereinafter also referred to as a thermal polymerization step). The ink may be polymerized to form pixels.

-Photopolymerization process-
Examples of the energy source used in the photopolymerization process include ultraviolet rays of 400 to 200 nm, far ultraviolet rays, g rays, h rays, i rays, KrF excimer laser rays, ArF excimer laser rays, electron beams, X rays, molecular rays, Alternatively, an ion beam or the like that is sensitive to the polymerization initiator described above can be appropriately selected and used. Specifically, a light source that emits actinic rays belonging to a wavelength region of 250 to 450 nm, preferably 365 ± 20 nm, for example, LD, LED (light emitting diode), fluorescent lamp, low pressure mercury lamp, high pressure mercury lamp, metal halide lamp, carbon arc lamp. , Xenon lamps, chemical lamps and the like. Preferred light sources include LEDs, high pressure mercury lamps, and metal halide lamps.

  The irradiation time of the active energy ray can be appropriately set according to the combination of the monomer and the polymerization initiator, and can be set to 1 to 30 seconds, for example.

-Thermal polymerization process-
The heating temperature and heating time in the thermal polymerization process depend on the composition of the ink-jet ink and the thickness of the pixel, but are generally about 120 ° C. to about 250 ° C. from the viewpoint of ensuring sufficient solvent resistance, alkali resistance, and ultraviolet absorbance. It is preferable to heat at about 10 minutes to about 120 minutes.

(Partition wall)
The partition used in the present invention may be any type, but is preferably a light-blocking partition having a black matrix function. The partition walls can be produced by the same material and method as those of known black matrixes for color filters. For example, paragraph numbers [0021] to [0074] of JP-A-2005-3861, black matrixes described in paragraph numbers [0012] to [0021] of JP-A-2004-240039, and JP-A 2006-17980 are disclosed. And the inkjet black matrix described in paragraphs [0009] to [0044] of JP-A No. 2006-10875.
Among the known production methods, it is preferable to use a photosensitive resin transfer material from the viewpoint of cost reduction. The photosensitive resin transfer material is a material in which at least a light-shielding resin layer is provided on a temporary support, and the resin layer having a light-shielding property can be transferred to the substrate by pressure bonding to the substrate.

The photosensitive resin transfer material is preferably formed using a photosensitive resin transfer material described in JP-A-5-72724, that is, an integral film. Examples of the constitution of the integral film include a temporary support / thermoplastic resin layer / intermediate layer / photosensitive resin layer (in the present invention, the “photosensitive resin layer” refers to a resin that can be cured by light irradiation, Is also referred to as a “light-shielding resin layer”, and when it is colored in a desired color, it is also referred to as a “colored resin layer”) / protective film laminated in this order.
Regarding the temporary support, the thermoplastic resin layer, the intermediate layer, the protective film, and the production method of the transfer material constituting the photosensitive resin transfer material, see paragraphs [0023] to [0066] of JP-A-2005-3861. Those described are preferred.

  The partition wall may be subjected to ink repellent treatment to prevent color mixing of the inkjet ink. As for the ink repellent treatment, for example, (1) a method of kneading an ink repellent substance into a partition wall (for example, see JP-A-2005-36160), and (2) a method of newly providing an ink repellent layer (for example, a special method) (See Kaihei 5-241101), (3) Method of imparting ink repellency by plasma treatment (for example, see JP-A-2002-62420), (4) Method of applying an ink-repellent material to the upper surface of the partition wall (See, for example, Japanese Patent Application Laid-Open No. 10-123500). In particular, (3) a method of performing an ink repellent treatment with plasma on a partition formed on a substrate is preferable.

  After forming the color filter by forming the pixel and the partition as described above, an overcoat layer can be formed so as to cover the entire surface of the pixel and the partition for the purpose of improving the durability.

The overcoat layer can protect the pixels such as R, G, and B and the partition walls and can flatten the surface. However, it is preferable not to provide from the point which the number of processes increases.
An overcoat layer can be comprised using resin (OC agent), and acrylic resin composition, an epoxy resin composition, a polyimide resin composition etc. are mentioned as resin (OC agent). Among them, an acrylic resin composition is desirable because it is excellent in transparency in the visible light region, and a resin component used for manufacturing a color filter usually contains an acrylic resin as a main component and has excellent adhesion. Examples of the overcoat layer include those described in paragraphs [0018] to [0028] of JP-A No. 2003-287618, and commercially available overcoat agents such as Optomer SS6699G manufactured by JSR.

  The color filter manufactured by the method for manufacturing a color filter of the present invention is suitably applied without particular limitation to applications such as a portable terminal such as a television, a personal computer, a liquid crystal projector, a game machine, and a mobile phone, a digital camera, and a car navigation system. it can.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited by the following Example.

[Preparation of dark color composition for barrier rib formation]
The dark color composition K1 is first weighed in the amount of K pigment dispersion 1 and propylene glycol monomethyl ether acetate listed in Table 1, mixed at a temperature of 24 ° C. (± 2 ° C.), stirred at 150 rpm for 10 minutes, and then Methyl ethyl ketone, binder 2, hydroquinone monomethyl ether, DPHA solution, 2,4-bis (trichloromethyl) -6- [4 '-(N, N-bisethoxycarbonylmethyl) amino-3' in the amounts shown in Table 1 -Bromophenyl] -s-triazine and Surfactant 1 are weighed out, added in this order at a temperature of 25 ° C. (± 2 ° C.), and stirred at 150 rpm for 30 minutes at a temperature of 40 ° C. (± 2 ° C.). It is done. In addition, the quantity of Table 1 is a mass part, and has the following composition in detail.

<K pigment dispersion 1>,
・ Carbon black (Nippex 35 manufactured by Degussa) 13.1%
-Dispersant 1 (the following compound 1) 0.65%
-Polymer (benzyl methacrylate / methacrylic acid = 72/28 molar ratio random copolymer, molecular weight 37,000) 6.72%
Propylene glycol monomethyl ether acetate 79.53%

<Binder 2>
・ Polymer (benzyl methacrylate / methacrylic acid = 78/22 molar ratio random copolymer, molecular weight 38,000) 27%
・ Propylene glycol monomethyl ether acetate 73%

<DPHA solution>
Dipentaerythritol hexaacrylate (containing 500 ppm of polymerization inhibitor MEHQ, manufactured by Nippon Kayaku Co., Ltd.,
Product name: KAYARAD DPHA) 76%
・ Propylene glycol monomethyl ether acetate 24%

<Surfactant 1>
・ The following structure 1 30%
・ Methyl ethyl ketone 70%

(Formation of partition walls)
The alkali-free glass substrate was cleaned with a UV cleaning apparatus, then brush-cleaned with a cleaning agent, and further ultrasonically cleaned with ultrapure water. The substrate was heat-treated at 120 ° C. for 3 minutes to stabilize the surface state.
After cooling the substrate and adjusting the temperature to 23 ° C., a dark color prepared as described above with a glass substrate coater (manufactured by FS Asia Co., Ltd., trade name: MH-1600) having a slit-like nozzle. Composition K1 was applied. Subsequently, a part of the solvent was dried with a VCD (vacuum dryer, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds to eliminate the fluidity of the coating layer, and then pre-baked at 120 ° C. for 3 minutes to obtain a dark colored composition having a thickness of 2 μm. Layer K1 was obtained.
In a proximity type exposure machine (manufactured by Hitachi High-Tech Electronics Engineering Co., Ltd.) with an ultra-high pressure mercury lamp, the exposure mask surface and dark color composition with the substrate and mask (quartz exposure mask with image pattern) standing vertically The distance between the physical layers K1 was set to 200 μm, and pattern exposure was performed at an exposure amount of 300 mJ / cm ² in a nitrogen atmosphere.
Next, pure water is sprayed with a shower nozzle to uniformly wet the surface of the dark color composition layer K1, and then a KOH developer (containing a nonionic surfactant, trade names: CDK-1, Fuji Film). Electronics Materials Co., Ltd. 100-fold diluted) was subjected to shower development at 23 ° C. for 80 seconds and a flat nozzle pressure of 0.04 MPa to obtain a patterning image. Subsequently, ultrapure water was sprayed at a pressure of 9.8 MPa with an ultra-high pressure cleaning nozzle to remove the residue, and post exposure was performed from the top surface at an exposure amount of 2500 mJ / cm ^{2 in} the atmosphere to obtain an optical density of 3. 9 barrier ribs were obtained. As a result, a rectangular droplet ejection area having a short direction of 84 μm and a longitudinal direction of 300 μm and a partition wall having a width of 15 μm are formed on the glass substrate.

[Ink repellent plasma treatment]
The substrate on which the barrier ribs were formed was subjected to ink repellent plasma treatment under the following conditions using a cathode coupling parallel plate type plasma treatment apparatus.
Gas used: CF ₄
Gas flow rate: 80sccm
Pressure: 40Pa
RF power: 50W
Processing time: 30 sec

<Preparation of inkjet ink>
An inkjet ink was prepared through the following steps.
-Preparation of pigment dispersion-
<Pigment dispersion for G (G1)>
Table 2 below shows pigment dispersant 1 (compound 1) and solvent (1,3-butanediol diacetate) (hereinafter abbreviated as 1,3-BGDA) in brominated phthalocyanine green (CI Pigment Green 36). After premixing, disperse for 9 hours with a motor mill M-50 (manufactured by Eiger Japan) using zirconia beads with a diameter of 0.65 mm at a peripheral speed of 9 m / s. A liquid (G1) was prepared.

<Other pigment dispersions>
In the G pigment dispersion (G1), the G pigment dispersion (G2) and the R pigment were the same as the G pigment dispersion (G1) except that the pigment and other components were blended as shown in Table 2. Dispersions (R1) and (R2) and pigment dispersions for B (B1) and (B2) were prepared.

-Preparation of ink-
<B inkjet ink>
After the following components were mixed and stirred at 25 ° C. for 30 minutes, it was confirmed that there was no insoluble matter, and a monomer liquid A was prepared.
(Monomer liquid A)
1,3-butanediol diacetate (1,3-BGDA; boiling point 232 ° C.) 4.0 parts propylene glycol monomethyl ether acetate (PGMEA; boiling point 146 ° C.)
28.0 parts Aronics M-309
(Trimethylolpropane triacrylate, viscosity: 85 mPa · s at 25 ° C.)
Toa Gosei Co., Ltd. 12.0 parts Surfactant 1 0.1 parts Thermal polymerization initiator V-40 (azobis (cyclohexane-1-carbonitrile))
0.6 parts manufactured by Wako Pure Chemical Industries, Ltd.

  Next, while stirring the following pigment dispersion, the monomer solution was slowly added and stirred at 25 ° C. for 30 minutes to prepare an inkjet ink for B (ink B-1).

B pigment dispersion (B1) 28.0 parts B pigment dispersion (B2) 28.0 parts

<Measurement of ink properties>
When the viscosity of the ink B-1 was measured under the following conditions using an E-type viscometer (RE-80L) manufactured by Toki Sangyo Co., Ltd., the viscosity was 8.5 mPa · s.
(Measurement condition)
-Rotor used: 1 ° 34 'x R24
・ Measurement time: 2 minutes ・ Measurement temperature: 25 ° C
Moreover, when the surface tension of the ink B-1 was measured using a surface tension meter (FACE SURFACE TENSIOMETER CBVB-A3) manufactured by Kyowa Interface Science Co., Ltd., the surface tension was 25.4 mN / m (at 25 ° C.). Met.

<Preparation of inkjet ink for R and inkjet ink for G>
The inkjet ink for B (ink B-1) was the same as the inkjet ink for B (ink B-1) except that the pigment dispersion and other components were blended as shown in Table 3. R-1) and an inkjet ink for G (G-1) were prepared.

  The contact angles (25 ° C.) of the inks B-1, R-1 and G-1 with the glass substrate were 10 degrees, 12 degrees and 9 degrees, respectively.

[Comparative Example 1]
As the inkjet head, SX-3 manufactured by Dimatix was used. This head has 128 nozzles at intervals of 508 μm, and each of the three heads is filled with ink of the three colors shown in Table 3. Each head is individually controlled for ejection. By setting the piezo voltage to 50 V, the pulse width to 8 μsec, and the frequency at the time of continuous ejection to 2 kHz, it is possible to eject a droplet of about 8 pl from each nozzle, and the droplet diameter at this time is about 25 μm.
The inkjet head is controlled to be transported two-dimensionally on the glass substrate, and can be ejected sequentially to a desired position by being controlled together with the ejection control of the head.

  By using this head to drop 30 drops into the droplet ejection area, 240 pl of ink is dropped into each droplet ejection area, and a suitable color filter can be obtained. At the time of droplet ejection, the substrate is held at 25 ° C.

  As shown in Table 4, 30 droplets were ejected at regular intervals on the 300 μm long side of the droplet ejection area. As shown in FIG. 4, the final droplet shape at this time was biased to the upstream side. As a result, a portion where the ink does not get wet occurs on the downstream side, causing a problem that the transmission density of the color filter is greatly reduced.

The cause of this phenomenon is estimated as follows. In order to land 30 droplets at equal intervals within a length of 300 μm in the longitudinal direction of the droplet ejection amount region, it is necessary to land at a droplet ejection interval of about 10 μm. Here, the diameter of the ink droplet is about 25 μm, and the first droplet that has landed isotropically spread on the glass surface, and then the next droplet lands. Since the force that tries to minimize the surface area works together with the first landing droplet that has landed and spread first from the moment when the second droplet contacted the preceding droplet, the central portion of the combined droplet shoots two drops each. It will be closer to the landing position of the first drop than the center of the target landing position. This phenomenon is repeated every time a subsequent droplet lands, and the shape after landing 30 droplets is biased toward the upstream side, and the amount of ink decreases on the downstream side.
When a portion where the ink does not get wet occurs, the density is greatly reduced. Even if the ink is wet, if the ink thickness in the droplet ejection amount region is not uniform, the density becomes uneven.
Further, since the distance between the landing position of the first droplet to land within the droplet ejection amount area and the partition wall is smaller than the radius of the droplet, the ink has run on the partition wall, and color mixing to adjacent pixels was observed.

[Comparative Example 2]
As shown in Table 5, when the droplet ejection interval is changed to unequal intervals, the area of the non-wetting portion on the downstream side is reduced as shown in FIG. 5, but there is still a non-wetting portion. By providing a portion with a large droplet ejection interval, a portion that delays the coalescence of droplets can be provided to improve the isotropic property of wetting, but if the size is insufficient, complete wetting is performed in this way. I can't get it. The ride on the partition wall generated in Comparative Example 1 did not occur by securing a predetermined distance between the initial landing position and the partition wall.
Here, in a portion where the droplet ejection interval is long, the ejection is temporarily stopped and the scanning is performed at a constant speed.

[Example 1] (First color filter manufacturing method)
As shown in Table 6, when a plurality of droplet ejection intervals were larger than twice the droplet diameter, a completely wet state could be secured as shown in FIG.

Example 2 (First Color Filter Manufacturing Method)
As shown in Table 7, it was also possible to ensure a completely wet state in the same manner as in Example 1 by taking a single droplet ejection interval larger than twice the droplet diameter.

As described above, when there is a portion where the droplet ejection interval is larger than twice the diameter of the ink droplet, the coalescence of the droplet with the upstream side is temporarily interrupted or weakened, so that wetting spreads downstream in the scanning direction. It was found that good results can be obtained.
In order to achieve this, scanning may be performed at a constant speed and ink droplets may be ejected from the head at unequal intervals. However, the scanning speed may be made variable to increase the scanning speed at a non-ejection portion. It is more effective to shorten

[ Reference Example 3] (Second Color Filter Manufacturing Method)
As shown in Table 8, when the distance between the first target landing position and the partition upstream in the scanning direction was larger than the distance between the last target landing position and the partition downstream in the scanning direction, the sample was completely wet as in Example 1. The state could be secured.

[ Reference Example 4] (third color filter manufacturing method)
After droplets are ejected in the first scanning direction to the first to fifteenth droplet ejection positions shown in Table 9, the same ink is scanned in the reverse direction, and the same ink is ejected from the sixteenth to thirty droplets. When droplets were ejected, a completely wet state could be ensured as in Example 1.
In this way, when the droplets are divided into two or more times, and the droplets are ejected from both ends in the scanning direction, the disadvantage that the positional fluctuation increases sequentially due to the interruption of the coalescence at the center is greatly reduced, and it is almost symmetrical from both ends. Good uniformity can be obtained by wetting and spreading at the center.

[ Reference Example 5] (Fourth Color Filter Manufacturing Method)
After droplets are deposited at approximately 12 μm intervals on the first to 20th droplets shown in Table 10, the droplet deposition interval is narrowed to approximately 3 μm from the 21st droplet, and the droplets are deposited on the 30th droplet. When dropped, it was possible to ensure a completely wet state as in Example 1.
In this way, a large gap is applied to a region of 250 μm upstream in the scanning direction of 300 μm, so that the unity is weak and thin and wet. Next, when 50 μm of the downstream side is narrowed and droplets are ejected, the ink ejected at a high density on the downstream side wets the downstream side well and flows to the upstream side to maintain good uniformity as a whole. I can do it.

It is a figure for demonstrating the change of the landing shape of the ink droplet at the time of dripping a some ink droplet. It is a figure for demonstrating the manufacturing method of a 2nd color filter. It is a figure for demonstrating the manufacturing method of a 3rd color filter. FIG. 4 is a diagram showing a final droplet shape of Comparative Example 1. FIG. 6 is a diagram showing a final droplet shape of Comparative Example 2. FIG. 3 is a diagram illustrating a final droplet shape of Example 1.

Explanation of symbols

10 Bulkhead 20 Drip amount range 30, 32 Target landing position

Claims (5)

The nozzle is formed as a plurality of ink droplets having the same diameter in the droplet ejection region by relatively scanning a substrate having a plurality of droplet ejection regions divided by a partition and an ink jet head having at least one nozzle hole. A method for producing a color filter having a step of droplet ejection from a hole,
Production of a color filter characterized in that at least one droplet ejection interval in the droplet ejection region is larger than twice the ink droplet diameter, and at least one droplet ejection interval is smaller than twice the ink droplet diameter. Method.   The color filter manufacturing method according to claim 1, wherein each of the droplet ejection regions is ejected from the same nozzle hole. The method for producing a color filter according to claim 1 or 2 , wherein a contact angle of the ink with the substrate at a substrate temperature is 5 degrees or more and 25 degrees or less. The method for producing a color filter according to any one of claims 1 to 3 , wherein the surface tension of the ink at a substrate temperature is 15 mN / m or more and 40 mN / m or less. The color filter manufacturing method according to any one of claims 1 to 4, characterized in that the viscosity of the ink at the substrate temperature is below 20 mPa · s.

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