JP2009098608A - Manufacturing method of substrate for liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a color filter substrate for a liquid crystal display apparatus by which a flattening layer and a patternizing layer can be batch-processed with high film thickness accuracy and further high performance and cost reduction of the liquid crystal display apparatus can be attained. <P>SOLUTION: The flattening layer which is nonphotosensitive and is hardly soluble or insoluble in a developing solution is formed by application and semicuring on the color filter substrate having two or more colored layers. Then a photosensitive resin is applied on the flattening layer, semicured and is exposed via a photomask. Only a photosensitive resin layer is etched by the developing solution and thereby the flattening layer and the patternizing layer can be batch-processed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a substrate for a liquid crystal display device comprising a planarizing layer made of a non-photosensitive resin and a patterned layer made of a photosensitive resin.

  Currently, liquid crystal display devices are used in various applications such as notebook PCs, portable information terminals, desktop monitors, digital cameras, and large liquid crystal televisions, taking advantage of characteristics such as light weight, thinness, and low power consumption. In a portable terminal, visibility regardless of location is regarded as important, and a transflective liquid crystal display device has been developed that enables display in each of transmissive display and reflective display within one pixel. In liquid crystal television applications, characteristics such as high-speed response, wide viewing angle, and high contrast are being improved.

  Along with the improvement in performance of liquid crystal display devices, conventional color filters consisting of a light-shielding layer, a colored layer, and a flattening layer, fixed spacers, resin protrusions for liquid crystal alignment control, resin layers for cell gap adjustment, etc. Color filters with additional structures have been developed.

  For example, as disclosed in Patent Document 1, in a conventional liquid crystal display device in which bead spacers are dispersed, the orientation of liquid crystal is disturbed around the bead spacers and the contrast is lowered. In the liquid crystal display device in which is formed, the contrast can be improved by forming the fixed spacer in the non-display region.

  Further, as disclosed in Non-Patent Document 1, in a vertical alignment mode liquid crystal display device using negative liquid crystal, a resin protrusion for controlling liquid crystal alignment so as to divide the liquid crystal alignment into a plurality of regions. By forming the, it is possible to increase the viewing angle.

  Furthermore, in Non-Patent Document 2, in a transflective liquid crystal display device, a transparent resin layer is formed in a reflective display region, and the cell gap of the reflective display region is narrowed, so that the optical path length with the transmissive display region is approximately the same. In addition, a configuration is disclosed in which the reflective display region and the transmissive display region are both bright transflective liquid crystal display devices.

  A configuration for keeping the distance between the opposing substrates of the display region and the non-display region in the liquid crystal display device constant is disclosed in Patent Document 3. According to this method, it is described that a transparent resin film having the same thickness as that of the color filter is formed on the liquid crystal side surface in the non-display area of one substrate to achieve the object. These additional structures are patterned and are usually formed through a photolithography process. Therefore, the color filter provided with the additional structure used in the high-performance liquid crystal display device has a problem that the photolithographic process is increased and the cost is increased as compared with the color filter having a simple configuration.

As a method for solving these problems, Patent Document 2 discloses an exposure mask formed of a semi-transmissive film having an ultraviolet transmittance control function capable of forming a flattening layer and a fixed spacer of a color filter at once and a light shielding film. Is disclosed. According to this method, the difference in photocuring of the negative resist is reflected in the film slide by utilizing the difference in ultraviolet transmittance between the semi-transmissive film made of ITO film and the light shielding film made of chromium film or the like. A flattening layer and a fixed spacer of the filter are formed at a time. However, with this method, it has been difficult to maintain the uniformity of the film thickness of the transflective exposed portion having a large amount of film slip, that is, the planarizing layer.
JP 2001-324716 A JP 2006-184399 A JP 2003-202551 A Electronic Journal October 1997, page 33 Nikkei Macrodevices separate volume "Flat Panel Display 2003 Practice" 108 pages

  An object of the present invention is to provide a manufacturing method capable of obtaining a liquid crystal display device substrate comprising a planarizing layer made of a non-photosensitive resin and a patterned layer made of a photosensitive resin at low cost and with high quality. To do.

In order to achieve the above object, the present invention comprises the following constitution.
1. A first layer formed by curing a non-photosensitive resin is formed on a transparent substrate having a plurality of colored layers, and a patterned photosensitive resin is further cured thereon. A method for manufacturing a substrate for a liquid crystal display device in which a second layer is laminated,
The manufacturing method of the board | substrate for liquid crystal display devices characterized by including the following process at least in this order.
(1) A step of applying and semi-curing a non-photosensitive resin on a transparent substrate on which a colored layer is formed (2) A step of applying and semi-curing a photosensitive resin on the non-photosensitive resin layer (3) The photosensitive resin layer (4) Step of exposing through a photomask (4) Step of etching only the photosensitive resin layer with a developer (5) Step of heating and curing the non-photosensitive resin layer and the photosensitive resin layer The method for producing a substrate for a liquid crystal display device according to (1), wherein the photosensitive resin is a resin composition containing at least a polymer, a photopolymerizable monomer, and a photopolymerization initiator.
3. The method for producing a substrate for a liquid crystal display device according to (1), wherein the photosensitive resin is a photosensitive resin composition containing a naphthoquinonediazide compound.
4. The method for producing a substrate for a liquid crystal display device according to any one of (1) to (3), wherein the non-photosensitive resin is insoluble or hardly soluble in the developer.
5. The method for producing a substrate for a liquid crystal display device according to any one of (1) to (4), wherein the second layer made of the patterned photosensitive resin is a protrusion for controlling the alignment of the vertical alignment liquid crystal.
6. The method for producing a substrate for a liquid crystal display device according to any one of (1) to (4), wherein the second layer made of the patterned photosensitive resin is a fixed spacer.
7. The liquid crystal display device according to any one of (1) to (4), wherein the second layer made of the patterned photosensitive resin is a gap adjustment layer that adjusts the thickness of the liquid crystal layer in the reflective region of the transflective liquid crystal display device. Manufacturing method for industrial use.
8. The liquid crystal display device according to any one of (1) to (4), wherein the patterned second layer made of a photosensitive resin is formed in at least a part of the frame region of the liquid crystal display device. A method for manufacturing a substrate.
9. The method for producing a substrate for a liquid crystal display device according to (8), wherein the patterned photosensitive resin contains a black pigment or a blue pigment.

  According to the method for manufacturing a substrate for a liquid crystal display device of the present invention, the flattening layer and the patterned layer of the color filter for the liquid crystal display device can be collectively processed with high film thickness accuracy, and the performance and cost of the liquid crystal display device can be improved. Can be achieved.

  As a result of intensive studies on a method of collectively processing the flattening layer and the patterned layer of the color filter for a liquid crystal display device with high film thickness accuracy, the present inventors have found that the following method is possible.

  That is, a non-photosensitive and insoluble or insoluble flattening layer is applied to a developing solution on a color filter substrate having a plurality of colored layers. After semi-curing, a photosensitive resin is applied and semi-cured. Subsequently, after exposure through a photomask, only the photosensitive resin layer is etched with a developer, whereby the planarization layer and the patterned layer can be collectively processed.

  As a method for obtaining a color filter by photolithography, there are a non-photosensitive polyimide method and a photo-acrylic method, but it is more preferable to apply to a non-photosensitive polyimide method manufacturing apparatus. In the non-photosensitive polyimide method, a non-photosensitive polyimide paste is applied, semi-cured, a positive resist is applied, semi-cured, and exposed, and then the non-photosensitive polyimide and the positive resist are patterned at once with a developer. Thereafter, the positive resist is stripped with a suitable stripping solvent and cured by heating. Thus, in the manufacturing apparatus of the non-photosensitive polyimide method, two coating and semi-cure processes are included in one process, and it is easy to apply the manufacturing method of the present invention.

  The semi-cure in the present invention refers to heat treatment at a relatively low temperature mainly for the purpose of volatilization of the solvent component, and specifically refers to heat treatment at 180 ° C. or lower. The temperature of the semi-cure is not particularly limited as long as it is in the above range, but when the solvent is not sufficiently volatilized, solvent replacement occurs when the photosensitive resin is applied, and the underlying non-photosensitive planarizing layer is Since there exists a possibility of swelling, 100 degreeC or more is preferable. More preferably, it is 130 ° C or higher, and further preferably 150 ° C or higher. The method for performing the semi-cure is not particularly limited as long as it does not affect the underlying non-photosensitive planarizing layer, and a known method such as a hot plate, a hot air oven, an IR heater can be used. Similarly, the semi-cure time is not particularly limited, and can be performed in a time of about 1 minute to 90 minutes.

  About the non-photosensitive planarization layer in this invention, there is no limitation in particular about the resin component, An epoxy resin, an acrylic epoxy resin, an acrylic resin, a siloxane polymer, a polyimide, a silicon containing polyimide, a polyimide siloxane etc. can be used.

  The photosensitive resin can also be used without any particular limitation, and may be a so-called negative photosensitive resin composition containing a polymer, a photopolymerizable monomer, a photopolymerization initiator, or the like, such as a naphthoquinone diazide compound. A positive photosensitive resin composition containing the photoacid generator may be used. As the solvent used in the photosensitive resin composition, any solvent can be used without particular limitation as long as it dissolves the resin component and does not swell and dissolve the non-photosensitive resin layer after semi-curing as a base.

  For example, ethylene glycol or propylene glycol derivatives such as methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, propylene glycol monoethyl ether, or propylene glycol monoethyl ether acetate, ethyl acetoacetate, methyl-3-methoxypropionate Aliphatic esters such as 3-methyl-3-methoxybutylacetate, aliphatic alcohols such as ethanol and 3-methyl-3-methoxybutanol, ketones such as cyclopentanone and cyclohexanone, N-methyl- Amide polar solvents such as 2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-va Rorakuton, .gamma.-caprolactone, lactones such as ε- caprolactone can be used. It is preferable to use a single solvent or a mixed solvent of two or more solvents that dissolve these resin components in an appropriate combination. In this case, a poor solvent for the resin to be used can be used as the auxiliary solvent. The preferred solvent is not particularly limited, and examples thereof include a mixed solvent of ethylene glycol or propylene glycol derivative such as propylene glycol monoethyl ether and ketones such as cyclohexanone.

  Suitable methods for applying the non-photosensitive resin composition and the photosensitive resin composition include a dipping method, a roll coating method, a spin coating method, a die coating method, a die coating and spin coating combined method, and a wire bar coating method. Used for. After the photosensitive resin composition is applied on the substrate, the solvent is removed by air drying, reduced pressure drying, heat drying or the like to form a coating film of the photosensitive resin composition. It is more preferable to provide a reduced-pressure drying step before performing semi-cure in an oven or a hot plate, since the coating defects caused by convection are eliminated. Subsequently, an exposure process of photolithography processing is performed. A mask is set on the coating film of the photosensitive resin composition and selectively exposed to ultraviolet rays using an ultrahigh pressure mercury lamp, a chemical lamp, a high pressure mercury lamp or the like.

The amount of exposure is not particularly limited, but is preferably 30 to 500 mJ / cm ² when expressed by the time integral value of irradiance at 365 nm. The exposure gap is not particularly limited, but is preferably 50 μm or more from the viewpoint of mask contamination.

  As the alkali developer, either an organic alkali developer or an inorganic alkali developer can be used. In the inorganic alkaline developer, an aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide or the like is preferably used. In the organic alkali developer, an aqueous amine solution such as an aqueous tetramethylammonium hydroxide solution or methanolamine is preferably used.

  The concentration of the alkaline substance in the developer is not particularly limited, but is usually 0.01 to 50% by mass, preferably 0.05 to 5% by mass. Further, a surfactant is also preferably used in the developer, and the pattern shape is improved by adding a nonionic surfactant or the like in an amount of 0.01 to 10% by mass, more preferably 0.1 to 5% by mass. You can also.

  Alkali development can be performed by dip development, shower development, paddle development or the like, and these may be combined. After the development, a washing step with pure water or the like may be appropriately added to remove the alkali developer.

  Thereafter, the laminated resin layer of the planarized film obtained through the development process and the patterned layer obtained from the photosensitive resin is subjected to heat treatment. The heat treatment is usually performed in air, in a nitrogen atmosphere, or in a vacuum at a temperature of 170 to 300 ° C, preferably 180 to 260 ° C, continuously or stepwise for 0.25 to 5 hours. Done.

  The patterned layer obtained by patterning the photosensitive resin is not particularly limited in its function, shape, etc., and has various functions, shapes, etc., such as fixed spacers, transparent resin layers, liquid crystal alignment control projections, etc. It may be.

For example, in a color filter for a transflective liquid crystal display device, a flattening layer made of a non-photosensitive resin on the entire surface of the substrate, and a transparent resin for adjusting the thickness of the liquid crystal layer to a position facing the reflective electrode of the counter substrate Patterned layers consisting of layers may be processed at once, or in a color filter for a liquid crystal display device, the total thickness of the flattened layer made of non-photosensitive resin, the display area and the frame area on the entire surface of the substrate is made equal. That is, a patterned layer made of a transparent resin layer may be collectively processed in the frame region so that the cell gap is uniform.
Here, the frame region refers to a light shielding portion formed at the peripheral edge of the display region.

Example 1
[Preparation of non-photosensitive resin composition (for flattening layer)]
After dissolving 65.05 g of trimellitic acid in 280 g of γ-butyrolactone, 74.95 g of γ-aminopropyltriethoxysilane was added and heated at 120 ° C. for 2 hours. To 20 g of the resulting solution, 7 g of bisphenoxyethanol fluorenediglycidyl ether and 15 g of diethylene glycol dimethyl ether were added and stirred at room temperature (about 23 ° C.) for 2 hours to obtain a non-photosensitive resin solution composition for a color filter.

[Application of non-photosensitive resin composition, semi-cure]
The obtained non-photosensitive resin solution composition for color filter was spin-coated on a color filter substrate consisting of a resin black matrix layer and a colored layer separately prepared so that the thickness after this curing was 1.5 μm, and a hot air oven Was heated at 130 ° C. for 5 minutes to obtain a semi-cured non-photosensitive resin composition coating film.

[Preparation of photosensitive resin composition (for transparent resin layer)]
70.0 g of acrylic copolymer solution (Daicel Chemical Industries, Ltd., Cyclomer P, ACA-250, 43 mass% solution), 30.0 g of dipentaerythritol hexaacrylate as a polyfunctional monomer, and 2-meryl as a photopolymerization initiator 10.0 g of -1- “4- (methylthio) phenyl” -2-morpholinopropan-1-one and 2- (2H-benzotriazol-2-yl) -4- (1,1, 3 g of 3,3-tetramethylbutyl) phenol and 217.5 g of cyclopentanone as a solvent were added, and a photosensitive transparent resin composition (A) having an acrylic resin concentration (total concentration of acrylic copolymer and monomer) of 20% by mass. Got.

[Coating of photosensitive resin composition, semi-cure]
The color filter substrate obtained by applying and semi-curing the non-photosensitive resin solution composition is spin-coated with the photosensitive transparent resin composition (A) so that the film thickness after the main curing is 2.0 μm. Then, by heating in a hot air oven at 90 ° C. for 5 minutes, a laminated coating film of a planarizing layer made of a semi-cured non-photosensitive resin composition and a resin layer made of the photosensitive resin composition (A) was obtained.

[Batch formation of flattening layer and transparent resin layer]
Using a UV exposure machine PLA-501F manufactured by Canon Inc., exposure was carried out through a photomask pattern at 300 mJ / cm ² (365 nm UV intensity). After the exposure, the film was immersed in a developer composed of a 0.5% aqueous solution of tetramethylammonium hydroxide and developed. A heat treatment is performed at 230 ° C. for 30 minutes, and a transparent resin layer having a thickness of 2.0 μm and a width of 30 μm is formed in a stripe shape on the reflective region of the color filter for a transflective liquid crystal display device on the planarizing layer having a thickness of 1.5 μm. The obtained color filter substrate could be obtained by batch formation.
Example 2
[Preparation of photosensitive resin composition (for fixed spacer)]
70.0 g of acrylic copolymer solution (Daicel Chemical Industries, Ltd., Cyclomer P, ACA-250, 43 mass% solution), 30.0 g of dipentaerythritol hexaacrylate as a polyfunctional monomer, and 2-meryl as a photopolymerization initiator −1- “4- (methylthio) phenyl” -2-morpholinopropan-1-one was added in an amount of 10.0 g, and cyclopentanone 217.5 g was added as a solvent, and the acrylic resin concentration (total concentration of acrylic copolymer and monomer) was added. ) 20% by mass of a photosensitive transparent resin composition (B) was obtained.

[Batch formation of flattening layer and transparent resin layer (for fixed spacer)]
A non-photosensitive resin solution composition prepared in the same manner as in Example 1 was applied and semi-cured, and the film thickness after the main curing of the photosensitive transparent resin composition (B) was 4 on the color filter substrate. A flattened layer made of a non-photosensitive resin composition and a resin layer made of a photosensitive resin composition (B), which were spin-coated to 0.0 μm and heated in a hot air oven at 90 ° C. for 5 minutes. A laminated coating film was obtained.

Then, 300 mJ / cm < ² > (365 nm ultraviolet intensity) exposure was carried out through the photomask pattern using Canon Inc. ultraviolet exposure machine PLA-501F. After the exposure, the film was immersed in a developer composed of a 0.5% aqueous solution of tetramethylammonium hydroxide and developed. Heat treatment is performed at 230 ° C. for 30 minutes, and a color filter substrate in which a transparent resin layer having a thickness of 4.0 μm and a diameter of 15 μm is formed in a non-display region on a flattening layer having a thickness of 1.5 μm can be obtained by batch formation did it.
Example 3
[Batch formation of planarization layer and liquid crystal alignment control protrusions]
A positive resist “SRC-200” manufactured by Shipley Far East is applied to a color filter substrate obtained by applying and semi-curing a non-photosensitive resin solution composition prepared in the same manner as in Example 1, and the film thickness after this cure is thick. The film was applied to a thickness of 1.5 μm and dried in an oven at 90 ° C. for 10 minutes to obtain a laminated coating film of a planarizing layer made of a semi-cured non-photosensitive resin composition and a resin layer made of a positive resist.

Subsequently, exposure was carried out at 50 mJ / cm ² (ultraviolet intensity of 365 nm) through a photomask pattern using a UV exposure machine PLA-501F manufactured by Canon Inc. After exposure, the film was developed by being immersed in a developer composed of a 2.0% aqueous solution of tetramethylammonium hydroxide. Heat treatment at 230 ° C. for 30 minutes to obtain a color filter substrate having a 1.5 μm-thick stripe-shaped projection for controlling liquid crystal alignment formed on a flattening layer having a thickness of 1.5 μm by batch formation. I was able to.
Example 4
[Batch formation of flattening layer and transparent resin layer on frame]
The film thickness after the main curing of the photosensitive transparent resin composition (A) is applied to the color filter substrate obtained by applying and semi-curing the non-photosensitive resin solution composition prepared in the same manner as in Example 1. A flattened layer made of a non-photosensitive resin composition and a resin layer made of a photosensitive resin composition (A), which were spin-coated to 0.0 μm and heated in a hot air oven at 90 ° C. for 5 minutes. A laminated coating film was obtained.

Then, 300 mJ / cm < ² > (365 nm ultraviolet intensity) exposure was carried out through the photomask pattern using Canon Inc. ultraviolet exposure machine PLA-501F. After the exposure, the film was immersed in a developer composed of a 0.5% aqueous solution of tetramethylammonium hydroxide and developed. A color filter that is heat-treated at 230 ° C. for 30 minutes, a transparent resin layer having a thickness of 2.0 μm is formed in a frame region on a flattening layer having a thickness of 1.5 μm, and the total thickness of the display region and the frame region is equal to each other The substrate could be obtained by batch formation.
Example 5
[Preparation of photosensitive black resin composition]
Weigh 300 g of Titanium Black 13M-T (titanium nitride) manufactured by Mitsubishi Materials Corporation, 150 g of a 45% by weight 3-methyl-3-methoxybutanol solution of acrylic polymer (P3), and 1050 g of propylene glycol tertiary butyl ether, and zirconia beads. Was dispersed at 2000 rpm for 4 hours to obtain a pigment dispersion (TB1) having a pigment concentration of 20% by mass. Propylene glycol of dipentaerythritol hexaacrylate (DHPA manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional monomer in 533 g of this pigment dispersion (TB1), 32.6 g of a 50% by weight solution of propylene glycol monomethyl ether acetate of bisphenoxyethanol full orange acrylate Monomethyl ether acetate 50 mass% solution 32.6 g, “Irgacure” 369 15.5 g as photopolymerization initiator, Asahi Denka Kogyo Co., Ltd. “ADEKA (registered trademark) Optmer” N-1919 4.3 g and N, N′- 1.6 g of tetraethyl-4,4′-diaminobenzophenone, 8.57 g of E2-AP1 (50% solution) as an adhesion improver (2% by mass of solid content), propylene glycol monomethyl ether acetate 10 of silicone surfactant quality A solution prepared by dissolving 5.36 g of a% solution in 439 g of 3-methyl-3-methoxy-butyl acetate and 16 g of propylene glycol monomethyl ether acetate was added and mixed to prepare a black color resist (solid content concentration 18% by mass). A photosensitive black resin composition (C) was obtained.

[Batch formation of flattening layer and black resin layer on frame]
A non-photosensitive resin solution composition prepared in the same manner as in Example 1 was applied and semi-cured, and then the photosensitive black resin composition (C) was cured to a thickness of 2 after the main curing. Spin coating to 0.0 μm, heating in a hot air oven at 90 ° C. for 5 minutes, a semi-cured planarization layer made of a non-photosensitive resin composition and a resin layer made of a photosensitive resin composition (C) A laminated coating film was obtained.

Then, 300 mJ / cm < ² > (365 nm ultraviolet intensity) exposure was carried out through the photomask pattern using Canon Inc. ultraviolet exposure machine PLA-501F. After the exposure, the film was immersed in a developer composed of a 0.5% aqueous solution of tetramethylammonium hydroxide and developed. A color filter that is heat-treated at 230 ° C. for 30 minutes, a black resin layer having a thickness of 2.0 μm is formed in a frame region on a flattening layer having a thickness of 1.5 μm, and the total thickness of the display region and the frame region is equal to each other The substrate could be obtained by batch formation.

Claims (9)

A first layer formed by curing a non-photosensitive resin is formed on a transparent substrate having a plurality of colored layers, and a patterned photosensitive resin is further cured thereon. A method for manufacturing a substrate for a liquid crystal display device in which a second layer is laminated,
The manufacturing method of the board | substrate for liquid crystal display devices characterized by including the following process at least in this order.
(1) A step of applying and semi-curing a non-photosensitive resin on a transparent substrate on which a colored layer is formed (2) A step of applying and semi-curing a photosensitive resin on the non-photosensitive resin layer (3) The photosensitive resin layer (4) Step of etching only the photosensitive resin layer with a developer (5) Step of heating and curing the non-photosensitive resin layer and the photosensitive resin layer The method for producing a substrate for a liquid crystal display device according to claim 1, wherein the photosensitive resin is a resin composition containing at least a polymer, a photopolymerizable monomer, and a photopolymerization initiator. The method for producing a substrate for a liquid crystal display device according to claim 1, wherein the photosensitive resin is a photosensitive resin composition containing a naphthoquinone diazide compound. The method for producing a substrate for a liquid crystal display device according to claim 1, wherein the non-photosensitive resin is insoluble or hardly soluble in the developer. The method for producing a substrate for a liquid crystal display device according to claim 1, wherein the second layer made of the patterned photosensitive resin is a protrusion for controlling the alignment of vertical alignment liquid crystal. The method for manufacturing a substrate for a liquid crystal display device according to claim 1, wherein the second layer made of a photosensitive resin subjected to pattern processing is a fixed spacer. 5. The liquid crystal display device substrate according to claim 1, wherein the second layer made of the patterned photosensitive resin is a gap adjusting layer that adjusts the thickness of the liquid crystal layer in the reflective region of the transflective liquid crystal display device. Method. 5. The method for producing a substrate for a liquid crystal display device according to claim 1, wherein the second layer made of the photosensitive resin subjected to pattern processing is formed on at least a part of the frame region of the liquid crystal display device. . The method for producing a substrate for a liquid crystal display device according to claim 8, wherein the patterned photosensitive resin contains a black pigment or a blue pigment.