JP2018178277A - Clear coated paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide clear coated paper having natural whiteness regardless of light sources.SOLUTION: The clear coated paper contains one or more layers of a clear coated layer on base paper and does not contain a fluorescent brightener. The clear coated paper has F1 in accordance with JIS P8148 being lower than or equal to 0.10 and whiteness being higher than or equal to 80%. By controlling a Labvalue under a light source not involving UV light in accordance with JIS P8150, in which a Lvalue is higher than or equal to 90 and lower than or equal to 98, a avalue is higher than or equal to -5 and lower than or equal to 2, and a bvalue is higher than or equal to -5 and lower than or equal to 5, respectively, the clear coated paper having a natural whiteness can be provided.SELECTED DRAWING: None

Description

  The present invention relates to a clear coated paper which is excellent in whiteness despite containing no fluorescent dye. More specifically, the present invention relates to a printing paper having a surface strength that is natural but has good whiteness and can withstand offset printing.

In recent years, high white sheets are sometimes required due to the beautifulness of printing, but on the other hand, users who desire natural colors, which are natural yellowish tones, are also increasing.
In order to whiten the paper or to make it appear whiter, a means for utilizing a fluorescent whitening effect generally using a fluorescent whitening agent (Patent Document 1), or a high white pigment such as calcium carbonate is coated (Patent Document 2) is used. A paper containing an optical brightening agent absorbs ultraviolet light of 300 to 400 nm and emits blue light of 400 to 500 nm to emit a visible light, thereby obtaining a whitening effect. In addition, there is also a technology in which by adding a blue coloring material, the appearance whiteness of the paper is increased, and the whiteness appears more prominent than the whiteness measured by the device (Patent Document 3).

JP, 2006-183192, A JP, 2013-129939, A JP, 2010-287426, A

However, papers containing optical brighteners can not be used for food applications due to health effects. Moreover, the whitening effect of the fluorescent dye not only can not be obtained under a light source having no ultraviolet light, but also the hue of the paper is changed. Since inks used in offset printing and the like often do not contain a fluorescent whitening agent, when printed on paper containing a fluorescent whitening agent, the hue of the paper changes when the light source changes. Since the contrast between the printed portion and the non-printed portion changes, there arises a problem that the image of the finished print changes.
Moreover, although the paper which added the blue coloring material increases the whiteness of appearance, it will become not bluish white but bluish white. There is regionality in the way of feeling the color, and in areas with strong ultraviolet light such as southern countries, fluorescent whitening agents and bluish white are preferred, but yellowish in relatively low latitude especially in Japan It is known that they tend to prefer natural white. In addition, there is also a method of adding a yellow dye to make a yellowish paper, but with this method, the yellowishness becomes too strong, and the natural yellowishness is lost.

  In view of the above background, it is an object of the present invention to provide a clear coated paper with natural whiteness that does not depend on a light source.

As a result of intensive studies to solve the above problems, the present inventors have found that natural whiteness not due to a light source can be obtained by not containing a fluorescent whitening agent and not using DIP or a material derived from broke. It has been found that a clear coated paper can be obtained, and the present invention has been completed. Although not limited to this, the above-mentioned subject is solved by the following invention.
(1) A clear coated paper having one or more clear coated layers on a base paper, wherein the clear coated layer does not contain a fluorescent brightening agent, F1 according to JIS P8148 is 0.10 or less, white Clear coated paper with a degree of 80% or more.
(2) ^L by the light source that does not contain an ultraviolet by JIS P8150 ^{* a} * ^b * values respectively, ^{L *} values of 90 or more 98 or less, ^{a *} value is -5 to 2, ^{b *} value is -5 to 5 The clear coated paper described in (1).
(3) The clear coated paper according to (1) or (2), wherein the base paper contains no fluorescent whitening agent.
(4) The clear coated paper according to any one of (1) to (3), wherein the base paper does not contain deinked pulp.
(5) The clear coated paper according to any one of (1) to (4), which is an offset printing paper.

  According to the present invention, it is possible to obtain a clear coated paper having natural whiteness not depending on a light source.

The clear coated paper of the present invention can be provided with a clear coated layer containing an adhesive as a main component (hereinafter sometimes referred to as a size press layer in the present specification). In the present invention, clear coated paper is made of base paper (hereinafter sometimes referred to as "base paper" or "base paper layer" in the present specification), or at least one layer on one side or both sides of the base paper. It is a paper having a clear coating layer.
The clear coated paper obtained by the present invention is printed by a printing method such as lithographic printing such as cold offset printing and heat offset printing, intaglio printing such as gravure printing, letterpress printing, inkjet printing, wet / dry electrophotographic printing etc. can do. Moreover, printing paper, envelope paper, wrapping paper, a paper bag etc. are mentioned as an application, and it can also be used for envelope paper, wrapping paper, a paper bag etc., after giving printing. The clear coated paper of the present invention is particularly suitably used as a printing paper because a natural-feeling printed matter can be obtained.

Production of Clear Coated Paper The clear coated paper of the present invention can be produced by a known method. For example, in the clear coated paper of the present invention, the papermaking raw material described below can be made into a paper by a wire part, and then it can be subjected to a press part and a pre-dryer part to produce a base paper. The coating solution to be coated is coated on a base paper, and then applied to an after-dryer part, a calendar part, a reel part, a winder part, and the like. In addition, it is possible to make a papermaking material with a wire part and then to provide a press part and a pre-dryer part to manufacture a base paper, and to clear coat a water-soluble polymer (binder) on the base paper.

[Base paper]
The clear coated paper of the present invention has at least a base paper layer. The base paper used in the present invention may be a single layer paper or a multilayer paper. The process for producing the base paper of the present invention is not particularly limited, and can be carried out by known methods using known raw materials.

[Raw pulp]
The pulp used in the present invention is not particularly limited, and general pulp raw materials can be used. Specifically, in addition to general wood, non-linter, hemp, bagasse, kenaf, esparto grass, straw etc. Wood, various synthetic raw materials, etc. can be used. In addition, as pulp, mechanical pulp (MP), deinked pulp (DIP, also called waste paper pulp), hardwood kraft pulp (LKP), softwood kraft pulp (NKP), etc. are generally used as paper making materials for paper It is preferable to use the following materials: semi-synthetic fibers such as rayon and acetate; and synthetic fibers such as polyolefin, polyamide and polyester. These pulps and fibers are used by blending one or more kinds. The mechanical pulp may, for example, be ground pulp (GP), refiner ground pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemigland pulp (CGP), semichemical pulp (SCP), etc. .

  In general, since deinked pulp contains waste paper containing a fluorescent whitening agent as a raw material, the base paper of the present invention includes deinked pulp using waste paper containing a fluorescent whitening agent as a raw material, and fluorescence increase It is preferable not to use a broke-derived material containing a whitening agent.

[Filler]
The filler used for the clear coated paper of the present invention is not particularly limited, and for example, calcium carbonate such as ground calcium carbonate and light calcium carbonate, titanium oxide, clay, silica, talc, kaolin, calcined kaolin, delami Kaolin, magnesium carbonate, barium carbonate, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, titanium oxide, inorganic fillers such as bentonite; urea-formalin resin, polystyrene Organic fillers such as resins, melamine resins, phenol resins, and micro hollow particles can be used singly or in appropriate combination of two or more. In the present invention, in particular, calcium carbonate is preferably used as a filler, and light calcium carbonate is particularly preferably used, since it is inexpensive and has excellent optical properties. In addition, composite fillers such as calcium carbonate-silica composites (for example, light calcium carbonate-silica composites described in JP-A 2003-212539 or JP-A 2005-219945) can also be used. In acidic papermaking, fillers obtained by removing acid-soluble ones from the above-mentioned fillers used in neutral papermaking are used, and they are used singly or in combination of two or more kinds as appropriate.

In the present invention, it is particularly preferable to contain calcium carbonate as an internally added filler because the opacity and whiteness of paper can be improved at relatively low cost. From the viewpoint of increasing the opacity and whiteness, the calcium carbonate content of the base paper is preferably 5% by weight or more, more preferably 7% by weight or more, and more preferably 10% by weight or more with respect to 100% by weight of pulp. It is further preferred that In addition, talc may be used in combination to adjust the balance of natural whiteness. When calcium carbonate and talc are used in combination as a filler, the ratio of both in paper is preferably calcium carbonate: talc = 50: 50 to 99: 1. By setting it as the said range, the clear coated paper with well-balanced natural whiteness as mentioned above can be obtained.

[adhesive]
In the present invention, although not particularly limited, an adhesive can be used. As the adhesive, a water-soluble polymer substance can be used, and as the water-soluble polymer, raw starch, oxidized starch, esterified starch, cationized starch, enzyme modified starch, aldehyde modified starch, hydroxyethylated starch , Starches such as hydroxypropylated starch; cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose; modified alcohols such as polyvinyl alcohol and carboxyl modified polyvinyl alcohol; styrene-butadiene copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate Copolymers, polyvinyl chloride, polyvinylidene chloride, polyacrylic acid esters and the like can be used alone or in combination. In the present invention, it is preferable to use starches which are inexpensive and have an effect of improving fiber fraction retention and ash content retention, more preferably cationized starch. Further, the adhesive content of the base paper is preferably 0.2% by weight or more and 3% by weight or less, and particularly preferably 0.5% by weight or more and 1.5% by weight or less with respect to 100% by weight of bone dry pulp.

[Other additives]
In the present invention, known papermaking additives can be used. The papermaking chemicals are not particularly limited, and various chemicals can be used alone or in combination. For example, retention agents, drainage improvers, coagulants, sulfate bands, bentonites, silica, sizing agents, dry strength agents, wet strength agents, bulking agents, fillers, dyes, pH adjusters, antifoaming agents, ultraviolet light Paper making chemicals such as inhibitors, antifading agents, pitch control agents, slime control agents can be used. Among them, it is preferable to add a retention agent as a papermaking chemical, and two or more may be mixed. Polyacrylamide polymers, polyvinyl alcohol polymers, cationic starches, various modified starches, urea / formalin resins, melamine / formalin resins can be suitably used as papermaking chemicals according to the present invention, in addition to retention agents. Internal dry strength agents such as polyamide; internal wet strength agents such as polyamidepolyamine epichlorohydrin resin; rosin type sizing agent, AKD type sizing agent, ASA type sizing agent, petroleum type sizing agent, neutral rosin Internal sizing agents such as sizing agents; and the like. In the present invention, it is preferable to use an ASA sizing agent to control the water absorbency of the base paper, etc. Further, to obtain a clear coated paper having a natural whiteness not depending on the light source, Preferably no brightener is added.

[Paper making method, paper machine]
The stock mixed with the paper making chemicals as described above is sent to the head box, and jetted from the head box onto the wire for paper making. The present invention can be applied to various papermaking machines and papermaking methods. As the paper machine, for example, papermaking can be suitably carried out with a Fourdrinier paper machine, twin wire paper machine, gap former paper machine, Yankee paper machine etc. As a twin wire paper machine, a gap former, an on top former, etc. may be mentioned. . In the present invention, a Fourdrinier paper machine is preferred. The papermaking system of the present invention is not particularly limited and may be neutral paper or acid paper, but when the paper of the present invention contains a relatively large amount of calcium carbonate, it is preferable to be neutral paper. Specifically, in the present invention, the paper surface pH is preferably 6.0 to 9.0, and more preferably 6.8 to 8.0. The papermaking speed is not particularly limited.

[Basic weight of base paper]
The basis weight of the base paper of the present invention is not particularly limited, but is about 35 g / m ² or more and 245 g / m ² or less.

  Furthermore, in the present invention, various surface treatments can be applied to the papermaking base paper. As surface treatment, surface coating, such as clear coating, can also be given, and calendar processing can also be given.

  In the present invention, when the surface treatment agent is coated on the base paper surface, for example, a surface coating apparatus or the like installed between a pre-dryer and an after-dryer can be used. As a coating apparatus, one generally used can be used.

Pre-calendar processing
In the present invention, the base paper prior to coating may be pre-calendered by an on-line soft calender, an on-line chilled calender, or the like to make the base paper smooth in advance.

[Clear coating]
The clear coated paper of the present invention has a clear (transparent) coated layer on one side or both sides of the above-mentioned base paper. In the present invention, clear coating means, for example, various starches such as starch and oxidized starch using a coater (coating machine) such as a size press, a gate roll coater, a premetaling size press, a curtain coater, or a spray coater. It means applying (size press) coating liquid (surface treatment liquid) which has water-soluble polymers, such as polyacrylamide and polyvinyl alcohol, as a main component on base paper.

  By applying clear coating on the base paper, the surface strength and smoothness of the base paper can be improved, and the coatability at the time of pigment coating can be improved. In the present invention, in order to obtain a clear coated paper having natural whiteness independent of a light source, it is preferable that the clear coating layer does not contain a fluorescent brightening agent.

  The type and composition of the surface coating agent to be clear-coated are not particularly limited, but as a water-soluble polymer substance for the purpose of strengthening the surface strength, raw starch, oxidized starch, esterified starch, cationized starch, Starches such as enzyme-modified starch, aldehydeated starch, hydroxyethylated starch, hydroxypropylated starch; cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, methylcellulose; modified alcohols such as polyvinyl alcohol and carboxyl modified polyvinyl alcohol; styrene butadiene copolymer Polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polyacrylic acid ester, polyacrylamide, etc. are used alone or in combination. Among them, application of starch is preferable, and corn starch and tapioca starch which use corn and tapioca as a raw material are particularly preferable. Also, in order to impart water absorption resistance to paper, common surface sizing agents such as styrenic compounds, olefinic compounds and alkyl (meth) acrylate compounds are applied in addition to the above water-soluble polymer substance. Is preferred. As a surface sizing agent to be used, an AKD sizing agent is preferred. Moreover, you may use it, mixing 2 or more types of surface sizing agents.

  When a surface treatment agent consisting of a water-soluble polymer substance and a surface sizing agent is applied, the mixing ratio of the water-soluble polymer substance to the surface sizing agent may be in the range of public use. Molecular substance: surface sizing agent = 5: 1 to 50: 1 is preferable.

In the present invention, the coating amount of the clear coating layer is preferably 0.5 g / m ² or more and 6.0 g / m ² or less in solid content (both sides), and 1.2 g / m ² or more and 5.0 g / m ² The following are more preferable, and more preferably 1.5 g / m ² or more and 4.0 g / m ² or less. By providing the clear coating layer in the above range, it is possible to obtain a clear coated paper having a surface strength that can withstand offset printing.

[Pigment coating]
The clear coating paper of this invention can also provide a pigment coating layer by pigment coating on a clear coating layer. When the pigment coated layer is provided on the printing paper of the present invention, the pigment coated layer may be a single layer or a multilayer, but in order to obtain the effects of the present invention, the fluorescence is also increased to the pigment coated layer. It is preferable not to contain a whitening agent.

In the present invention, the method for drying the wet coating layer is not limited, and for example, various methods such as steam heating cylinder, heated hot air dryer, gas heater dryer, electric heater dryer, infrared heater dryer may be used alone or in combination. it can.

  In the present invention, the paper surface may be subjected to calendering, but the type and processing conditions of the calendering device are not particularly limited, and common calenders made of metal rolls, soft nip calenders, high temperature soft nip calenders, etc. Devices may be selected appropriately, and conditions may be set within the controllable range of these devices according to the quality target value.

[Clear coated paper]
[Basic weight]
The basis weight of the printing paper of the present invention is not particularly limited, but is preferably 40 g / m ² or more and 250 g / m ² or less, and more preferably 45 g / m ² or more and 215 g / m ² or less.

[ash]
In the present invention, the ash content is measured by a method in which the combustion temperature is set to 525 ± 25 ° C. in accordance with the ash content test method for paper and paperboard specified in JISP 8251. The ash content of the clear coated paper of the present invention is preferably 5% by weight or more. In particular, the ash content is preferably 8% by weight or more, and more preferably 12% by weight or more. The upper limit of the ash content is not particularly limited, but in consideration of the strength and operability of the paper, 25% by weight or less is preferable, and 20% by weight or less is more preferable. If the ash content is higher than 25% by weight, the paper strength and interlayer strength may be reduced, and the printability and the processability may be reduced. In addition, if the ash content is less than 5% by weight, the opacity and whiteness may not be sufficiently improved.

[Hue]
The hue of the clear coated paper of the present invention is 90 ^* 98 or less in L ^* value, −5 or more and 2 or less in a ^* value, and b ^* value in the measurement with / without ultraviolet light specified in JIS P8150. Is preferably -5 or more and 5 or less. More preferably, L ^* value is 91 or more and 97 or less, a ^* value is -3 or more and 1 or less, b ^* value is -2 or more and 2 or less, L ^* value is 92 or more and 96 or less, a ^* value is -2 Above 0, b ^* value is -1 or more and 1 or less. By setting the L ^* a ^* b ^* value in the above range as described above, it is possible to obtain a clear coated paper having a sufficient whiteness while having a natural texture. If it is out of the above range, the color of the clear coated paper may not be visible as natural white, which is not preferable. Moreover, it is preferable that F1 value measured using Murakami Color Co., Ltd. product color difference meter CMS-35SPX based on JISP8148 is 0.10 or less, More preferably, it is 0.05 or less. When the clear brightening paper is contained in the clear coated paper, the F1 value becomes higher than 0.10, because the brightening whitening agent is added to the base paper and coating layer, and the base paper contains DIP. The light source changes the hue. As a measuring apparatus, Murakami Color Co., Ltd. product color-difference meter CMS-35SPX etc. are mentioned.

[Whiteness]
80% or more is preferable and, as for ISO whiteness measured based on JISP8148 of the clear coated paper of this invention, 83% or more is more preferable. If it is less than 80%, it is difficult to say that it is a clear coated paper excellent in whiteness even for eyes. As a measuring apparatus, Murakami Color Co., Ltd. product color-difference meter CMS-35SPX etc. are mentioned.

Opacity
The opacity of the clear coated paper of the present invention measured according to JIS P8149 is preferably 75% or more, more preferably 80% or more, and still more preferably 85% or more. If the opacity is lower than 75%, problems such as penetration of printed matter may occur, or contents may be seen through when used as an envelope. As a measuring apparatus, Murakami Color Co., Ltd. product color-difference meter CMS-35SPX etc. are mentioned.

[density]
The density of the clear coated paper of the present invention is preferably 0.70 g / cm ³ or more and 1.00 g / cm ³ or less, and more preferably 0.75 g / cm ³ or more and 0.95 g / m ³ or less. If the density is lower than 0.75 g / m ² , the strength at the time of offset printing may be insufficient, which may result in unnecessary printing or contamination of the printing press.

  The present invention will be described in more detail by way of examples and comparative examples relating to clear coated paper below, but the present invention is of course not limited to the examples. In the examples, parts and% indicate parts by weight and% by weight, respectively.

[Quality evaluation method]
The quality of the clear coated paper of the present invention was evaluated by the quality evaluation method described below.
(1) Hue measurement method (a ^* , b ^* ): Based on JIS P8150, Murakami Color Co., Ltd. product color difference meter CMS-35SPX, base paper or clear coated paper from a light source containing ultraviolet light and ultraviolet light It measured by the light source which does not contain.
(2) F1: Based on JIS P8148, the base paper or clear coated paper was measured with a light source containing ultraviolet light using Murakami Color Co., Ltd. product color difference meter CMS-35SPX.
(3) ISO Whiteness Measurement Method: Measured according to JIS P8148 using a color difference meter CMS-35SPX manufactured by Murakami Color Co., Ltd. using a light source containing ultraviolet light.
(4) Opacity measurement method: According to JIS P8149, it measured by Murakami Color Co., Ltd. product color difference meter CMS-35SPX.
(5) Ash content measuring method: It measured based on JISP8251.
(6) Basis weight: According to JIS P8124: 1998 (ISO 536: 1995).
(7) Texture (visual evaluation): The obtained clear coated paper was evaluated according to the following criteria.
:: natural texture with natural whiteness :: slightly yellowish or bluish ×: yellowish or bluish

[Example 1] Talc and light calcium carbonate as a filler were added to a pulp slurry of 100 parts of LBKP at a ratio of 1: 4 so that the ash content was 15%, and the stock was adjusted.
Thereafter, the above-mentioned stock was jetted out from the head box onto a long wire type papermaking wire to make a paper, water was squeezed by a press part and dried by a pre-dryer, and a base paper was made at a paper making speed of 550 m / min. A clear coating solution containing 5% of corn modified starch, 0.25% of styrene sizing agent and 0.1% of AKD sizing agent is applied to the obtained base paper using a pound type size press, and the coated amount is double-sided Both sides were uniformly coated so as to be 1.72 g / m ² (solid content). After drying, a clear coated paper having a basis weight of 81.5 g / m ² , a paper thickness of 97 μm, and an ash content in paper of 14.4% was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

Example 2
The total amount of internally added filler as light calcium carbonate is adjusted to 9% ash content as the pulp composition of the base paper is 97 parts by weight of LBKP and 3 parts by weight of NBKP, and the stock is adjusted. A clear coated paper is prepared by the method described in Example 1 except that the coated paper is evenly coated on both sides so as to be 56 g / m ² (solid content), and the basis weight is 47.5 g / m ² and the paper thickness is 61 μm. Clear coated paper with 8.9% ash content in paper was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

[Example 3]
As a filler, talc and light calcium carbonate are set to 2: 3, 6.5% by weight of starch in the clear coating liquid, 0.3% by weight of styrenic sizing agent, 0.2% by weight of AKD sizing agent, coating amount A clear coated paper is prepared by the method described in Example 1 except that the both sides are evenly coated to give 3.50 g / m ² (solid content) on both sides, and the basis weight is 128.7 g / m ² , paper A clear coated paper with a thickness of 152 μm and an ash content of 14.8% in paper was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

Example 4
The clear coating liquid contains 8% by weight of starch, 0.5% by weight of a styrene sizing agent, and 0.08% by weight of an AKD sizing agent, and the coating amount is 3.43 g / m ² (solid content) on both sides. equally except for the coating creates a clear coated paper in example 3 described methods, basis weight 210.3g / ^{m 2,} paper thickness 239 g / ^{m 2,} clear coating of 14.9% in ash content of paper as I got a craft paper. The measured values of paper quality and the evaluation results are shown in Table 1.

Comparative Example 1
The ratio of talc to light calcium carbonate in the internal addition filler of base paper is 1: 9, the starch of clear coating liquid is 7% aqueous solution, 0.05% fluorescent dye is added, and the coating amount is double sided. in except for uniformly applied so that the 2.58 g / ^{m 2} is to create a clear coated paper by the method described in example 1, basis weight 81.6 g / ^{m 2,} the sheet thickness 97 [mu] m, in the paper A clear coated paper with an ash content of 15.9% was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

Comparative Example 2
A clear coated paper is prepared in the same manner as in Comparative Example 1 except that the addition amount of the fluorescent dye is 0.32%, and the basis weight is 81.0 g / m ² , the paper thickness is 96 μm, and the ash content in the paper is 17.2%. Clear coated paper was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

Comparative Example 3
A clear coated paper was prepared by the method described in Example 1 except that the ratio of talc to heavy calcium carbonate in the internally added filler of the base paper is 2: 8 and the clear coating liquid contains 200 g / t of yellow dye. A clear coated paper having a basis weight of 80.9 g / m ² , a paper thickness of 96 μm, and an ash content of 13.8% was obtained. The measured values of paper quality and the evaluation results are shown in Table 1.

As can be seen from Table 1, in Examples 1 to 4 which do not contain a fluorescent whitening agent, the whiteness with a light source containing ultraviolet light is slightly lower than that of Comparative Example 1 which contains a fluorescent whitening agent, but the F1 value Became a clear coated paper with a natural texture. Further, Comparative Example 2 in which the added amount of the fluorescent whitening agent is larger than that of Comparative Example 1 has a b ^* (UV-cut) value as low as -3.91 and is clear coated paper with bluish tint compared to the example. It became. Furthermore, Comparative Example 3 containing a yellow dye has a high b ^* (UV-cut) value of 9.17 and a strong yellowishness, so the whiteness is low as compared with Examples 1 to 4, and a natural feeling is obtained. It was also inferior.

Claims (5)

A clear coated paper having one or more clear coating layers on a base paper,
The clear coating layer does not contain a fluorescent whitening agent,
Clear coated paper having an F1 of 0.10 or less and a whiteness of 80% or more according to JIS P8148. JIS P8150, each ^L * ^a * ^{b *} values by the light source that does not contain UV by, ^{L *} value is 90 or more 98 or less, ^{a *} value is -5 to 2, ^{b *} value is -5 to 5, The clear coated paper according to claim 1.   The clear coated paper according to claim 1 or 2, wherein the base paper contains no fluorescent whitening agent. The clear coated paper according to any one of claims 1 to 3, wherein the base paper does not contain deinked pulp.   The clear coated paper according to any one of claims 1 to 4, which is an offset printing paper.