JP2012187768A - Chromatic color removable pressure adhesive recording paper and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide chromatic color removable pressure adhesive recording paper, which eliminates color unevenness, is excellent in productivity, obtains even and precise peeling feeling, enabling smooth peeling when the receiver of the paper is intentionally peeled, and is chromatically colored and achieves excellent visibility in personal information.SOLUTION: The removable chromatic color pressure adhesive recording paper including a pressure sensitive adhesion layer containing a nonionic surfactant and a chromatic coloring pigment is colored so that ΔE calculated under condition 1 may be 2 or larger, and the lightness index L calculated under the condition 1 of the pressure adhesion layer is 88 or larger.

Description

  The present invention is a recording paper whose surface layer is colored with a color pigment, the colored surface layer has no color unevenness, and the recording paper does not adhere in a normal state, adheres by pressure, and peels again when necessary. The present invention relates to a colored releasable pressure-sensitive recording paper that can be used.

  Confidential postcards using releasable pressure-sensitive recording sheets have become widespread as means for notifying personal information such as savings and balances from banks, credit companies, insurance companies, government agencies, etc. to each individual. For confidential postcards, pressure sensitive adhesive is applied to the substrate, common information is printed by offset printing, gravure printing, etc., personal information is printed by laser beam method, ink jet method, etc. It is possible to obtain information by adhering by adding, mailing to each individual, and then re-peeling.

  In recent years, the use of releasable pressure-sensitive recording paper, such as direct mail for product introductions and private postcards for individuals of banks and insurance, has been kept secret, such as placing information on new products on parts other than personal information. It is expanding beyond the information notice. This is because the spread of digital printing machines capable of full color printing by ink jet or laser beam method has begun instead of conventional printing machines. Since the digital printing machine does not depend on the plate making like the conventional offset printing, unlike the printing machine, it is possible to print individual symbols in a small lot.

  However, among these, the releasable pressure-sensitive recording paper used in conventional confidential postcards is based on white, and contains a highly concealed pigment such as titanium or black pigment to improve the concealability. Thus, the opacity is improved (for example, see Patent Document 1 or 2).

  As a method of coloring, there is a method of applying a colored overcoat agent to a conventional uncolored inkjet paper and coloring it to some extent (see, for example, Patent Document 3). In addition, there is a method of halftone printing on the surface of ink jet paper (see, for example, Patent Document 4).

JP 2006-028706 A JP 2004-250834 A Japanese Patent Laid-Open No. 10-235993 JP-A-8-230307

Tokyo Chamber of Commerce and Industry, "Color Coordination", June 2002 4th Edition

  As in the technique described in Patent Document 1 or 2, re-peelable pressure-sensitive recording sheets are mostly based on white color and improve opacity. There was no re-peelable pressure-sensitive recording sheet. In addition, when black pigment or black dye is used for the purpose of providing concealment as in Patent Document 2, the personal information on the confidential postcard is printed with black ink or toner, so the visibility of the personal information is significantly reduced. To do. The reduction in visibility referred to here is caused by the color difference between the color of the pressure-sensitive recording paper and the black ink or black toner, which is personal information, and the brightness index L is lower than the decrease in the whiteness of the pressure-sensitive recording paper. This is due to the decline.

  Further, the coloring method of Patent Document 3 is liable to cause color unevenness, and further, the coloring is a separate process, which is uneconomical. When the entire surface is colored by halftone printing according to the method of Patent Document 4, the pressure-bonding force of the confidential postcard is reduced between the printed surfaces and cannot be used as the confidential postcard.

  Further, when the entire surface is colored by the above-described digital printer, a large amount of ink is consumed for both the ink jet type and the toner type, which is uneconomical. In addition, in an ink jet type digital printer, drying is not in time, and the printing speed must be reduced.

  Although there are various effects of coloring the recording medium, as described in Non-Patent Document 1, it is possible to give an image of place, use, person, meaning, beauty to an object at a low cost and to appeal the product There is. Although there are individual differences in color preferences, it is said that most people have the same image and associated color. For example, as the color temperature, the warm color system is red to yellow, and the cold color system is blue to blue purple. The colors that image the four seasons are spring “green, peach”, summer “yellow, blue”, autumn “orange, brown”, winter “red, black, white”, and color “association” with red “apple, amber, "Passion", yellow "lemon, banana, sunflower", green "spring, leaves, grass, forest, lawn, watermelon", orange "autumn, tangerine, persimmon, autumn leaves, sunset", blue "sky, sea, water", tea "Autumn, fallen leaves, soil", purple "red, coconut, violet". By selecting the appropriate color tone from the image given by these colors and applying it to confidential postcards and direct mail, it is possible to meet unprecedented social needs. Value can be created inexpensively.

  In the present invention, there is no color unevenness in a releasable pressure-sensitive recording paper chromatically colored and excellent in productivity, and when the recipient intentionally peels off, a uniform and fine peeling feeling can be obtained and smooth peeling is achieved. Another object of the present invention is to provide a colored releasable pressure-sensitive recording sheet that has a chromatic color tone and is excellent in the visibility of personal information, and a method for producing the same.

The chromatic colored releasable pressure-sensitive recording paper according to the present invention does not exhibit adhesiveness and adhesiveness at normal temperature and normal pressure on both sides of the support, exhibits adhesiveness when pressed, and re-peels after pressure bonding In a releasable pressure-sensitive adhesive recording paper on which a pressure-sensitive adhesive layer is formed, the pressure-sensitive adhesive layer contains a nonionic surfactant and a chromatic color pigment, and ΔE obtained under condition 1 is The lightness index L obtained by condition 1 of the pressure-sensitive adhesive layer is 88 or more.
(Condition 1)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support and the surface of the pressure-sensitive adhesive layer are measured. The measured values of the surface of the support are Lx, ax, bx, and the measured values of the surface of the pressure-sensitive adhesive layer are L, a, b. ΔE is calculated by Equation 1.
(Equation 1) ΔE = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )

The chromatic colored releasable pressure-sensitive recording paper according to the present invention does not exhibit adhesiveness or adhesiveness at normal temperature and normal pressure on one side of a support, exhibits adhesiveness when pressed, and is re-peeled after pressure bonding In a releasable pressure-sensitive adhesive recording sheet formed by forming a pressure-sensitive adhesive layer that is possible and forming a non-pressure-sensitive adhesive layer on the opposite surface of the support, the pressure-sensitive adhesive layer and the non-pressure-sensitive adhesive layer are , Containing a nonionic surfactant and a chromatic coloring pigment, and colored so that ΔE1 and ΔE2 determined in Condition 2 are both 2 or more, and determined in Condition 2 of the pressure-sensitive adhesive layer. The lightness index L1 is 88 or more.
(Condition 2)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support, the surface of the pressure-sensitive adhesive layer, and the surface of the non-pressure-sensitive adhesive layer are measured. The measured value of the surface of the support is Lx, ax, bx, the measured value of the surface of the pressure-sensitive adhesive layer is L1, a1, b1, and the measured value of the surface of the non-pressure-sensitive adhesive layer is L2, a2, b2, ΔE1 is calculated by Equation 2, and ΔE2 is calculated by Equation 3.
(Equation 2) ΔE1 = √ ((Lx−L1) ² + (ax−a1) ² + (bx−b1) ² )
(Equation 3) ΔE2 = √ ((Lx−L2) ² + (ax−a2) ² + (bx−b2) ² )

  When the lightness index L or L1 of the surface of the pressure-sensitive adhesive layer is 88 or more, the visibility of confidential information / personal information is excellent while having a chromatic color.

In the chromatic colored releasable pressure-sensitive recording paper according to the present invention, in (Condition 3), it is preferable that at least 9 points out of 10 points of ΔE3 satisfy 0.2 or less in both of the front surface and the back surface.
(Condition 3)
10 points along the width direction of the paper, 10 points every 5 mm, according to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", JIS Z 8730: 2009 "Color display method-Object color Both the front surface and the back surface are measured for the lightness index L and the perceptual chromaticity indices a and b defined by “color difference”. The measured values at 10 points are L, a, and b, respectively, and the average values at 10 points are Lx, ax, and bx. For each of 10 measured values, ΔE3 for 10 points is calculated according to Equation 4.
(Equation 4) ΔE3 = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )

  In the chromatic color releasable pressure-sensitive recording paper according to the present invention, the chromatic color pigment is preferably nonionic. When the color pigment is contained in the coating liquid, it hardly aggregates, and as a result, color unevenness hardly occurs.

  In the chromatic colored releasable pressure-sensitive recording paper according to the present invention, it is preferable that the support does not contain a colorant. Rather than producing a number of colored supports, applying a colored coating amount to a white support that does not contain a colorant can cope with multicolor products at low cost in the production process.

  The method for producing a chromatic colored releasable pressure-sensitive recording sheet according to the present invention is a method for producing a chromatic colored releasable pressure-sensitive recording sheet according to the present invention, comprising the nonionic surfactant and the chromatic color. A step of preparing a coating liquid containing the coloring pigment, and coating the coating liquid on the surface of the support to form the pressure-sensitive adhesive layer or the non-pressure-sensitive adhesive layer. To do. Color unevenness hardly occurs, production efficiency is high, and peel strength is easily obtained.

  The releasable pressure-bonded recording paper toned in chromatic color according to the present invention has no color unevenness, and when the recipient intentionally peels it off, a uniform and dense peel feeling can be obtained and can be smoothly peeled off. In addition to being highly colored, it has excellent visibility of personal information and high productivity. Moreover, if it is applied to direct mail and the like, it is possible to meet social needs that have not existed before, and it is possible to create a commercial value that is not found in general releasable pressure-sensitive recording paper at a low cost.

  Next, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  The releasable pressure-sensitive recording paper of the present invention preferably contains no colorant and is a non-colored support, more preferably one or both sides on a support having a whiteness of 78% or more according to JIS P 8148: 2001. A pressure-sensitive adhesive layer can be formed. When the pressure-sensitive adhesive layer is provided only on one side, it is a releasable pressure-sensitive adhesive recording sheet in which a non-pressure-sensitive adhesive layer is formed on the other side. This releasable pressure-sensitive recording sheet is printed with fixed information by an ultraviolet curable printing press for foam and the like, and then variable information is printed by an ink jet method or an electrophotographic method. The above-described digital printing machine can simultaneously print fixed information and variable information. Then it is folded in half or in three, and is mailed as a postcard, direct mail, etc. mainly in the form of a postcard.

  The pressure-sensitive adhesive layer does not exhibit tackiness and adhesiveness under normal conditions of normal temperature and normal pressure, exhibits adhesiveness when pressed, and has the property of being removable after pressure bonding. Filler and adhesive The coating liquid for forming the pressure-sensitive adhesive layer is mainly applied to the inner surface when folded in two and both surfaces when folded in three. The main component of the non-pressure-sensitive adhesive layer is different depending on the application, but does not show adhesiveness when pressed, and the coating solution for forming the non-pressure-sensitive adhesive layer is mainly applied as the outer surface when folded in two. . A chromatic coloring pigment is added to the coating liquid for forming the pressure-sensitive adhesive layer and the coating liquid for forming the non-pressure-sensitive adhesive layer, and the color tone is changed to the chromatic color of the pressure-sensitive adhesive layer and the non-pressure-sensitive adhesive layer.

  The chromatic coloring pigment is preferably nonionic. When writing personal information on a releasable pressure-sensitive recording sheet, water-based dye inks are frequently used in inkjet line printers. For this reason, since a strong ionic chemical is used for the pressure-sensitive adhesive layer and the non-pressure-sensitive adhesive layer in order to fix the aqueous dye ink, the ionic pigment is likely to aggregate and cause color unevenness. The paint for the re-peeling pressure-sensitive recording layer is made of silicon oil used for the purpose of absorbing the inkjet ink for recording the personal information described above, or for cleaning the toner fixing roll in the case of electrophotography. In order to prevent the pressure-sensitive adhesive strength from being reduced, an inorganic filler is blended for the purpose of absorbing this. However, since inorganic fillers generally have ionic properties, ionic coloring pigments tend to aggregate and cause uneven color. Cause. When a dye is used as the colorant, the storage stability is inferior, and fading is significant depending on environmental conditions such as light, heat and humidity. In addition, when a plurality of dyes are blended, since the degree of fading between the dyes is different, variation in color becomes a problem even in short-term storage.

  In the present embodiment, the coating liquid for forming the pressure-sensitive adhesive layer and the coating liquid for forming the non-pressure-sensitive adhesive layer are directly chromatically colored with a coloring pigment, and after coating and drying on the support, The lightness index L determined in Condition 1 of the pressure-sensitive adhesive layer or the lightness index L1 determined in Condition 2 of the pressure-sensitive adhesive layer is 88 or more, preferably 89 or more.

  Here, when forming a pressure-sensitive adhesive layer on both sides of the support, the lightness index L obtained under Condition 1 of the pressure-sensitive adhesive layer is obtained, the pressure-sensitive adhesive layer is formed on one side of the support, When forming the pressure-sensitive adhesive layer, the lightness index L1 obtained under condition 2 of the pressure-sensitive adhesive layer is obtained. Here, Condition 1 and Condition 2 are as follows.

(Condition 1)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support and the surface of the pressure-sensitive adhesive layer are measured. The measured values of the surface of the support are Lx, ax, bx, and the measured values of the surface of the pressure-sensitive adhesive layer are L, a, b. ΔE is calculated by Equation 1.
(Equation 1) ΔE = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )

(Condition 2)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support, the surface of the pressure-sensitive adhesive layer, and the surface of the non-pressure-sensitive adhesive layer are measured. The measured value of the surface of the support is Lx, ax, bx, the measured value of the surface of the pressure-sensitive adhesive layer is L1, a1, b1, and the measured value of the surface of the non-pressure-sensitive adhesive layer is L2, a2, b2, ΔE1 is calculated by Equation 2, and ΔE2 is calculated by Equation 3.
(Equation 2) ΔE1 = √ ((Lx−L1) ² + (ax−a1) ² + (bx−b1) ² )
(Equation 3) ΔE2 = √ ((Lx−L2) ² + (ax−a2) ² + (bx−b2) ² )

  When the lightness index L obtained in Condition 1 or the lightness index L1 obtained in Condition 2 is less than 88, confidential information / personal information is recorded mainly with black inkjet ink or toner, and thus visibility is poor. In the prior art, the whiteness is defined by adjusting the black color to prevent opacity, but the problem with the visibility of confidential information is actually obtained with the lightness index L obtained under Condition 1 or Condition 2. The lightness index L1. For example, the color tone with enhanced yellowness is low as whiteness, but the value of the lightness index L obtained in Condition 1 or the lightness index L1 obtained in Condition 2 is high, and the visibility is good. On the contrary, the black toning has poor visibility, and the indigo color also has poor visibility when the density is high. This is because visibility is due to the color difference between the color of the pressure-bonded paper and the color of the black text rather than the whiteness of the pressure-sensitive paper because the confidential information is black characters. Since the density of black characters actually used for confidential information varies, it is not particularly specified, but according to a measurement method according to JIS Z8722: 2009, the lightness index L of the surface specified by JIS Z 8730: 2009 is used. Using the method calculated from the perceptual chromaticity indexes a and b, the visibility is good if ΔE between the surface of the colored releasable pressure-sensitive recording sheet and the confidential information recording portion is 60 or more. In addition, when the lightness index L obtained in Condition 1 or the lightness index L1 obtained in Condition 2 is less than 88, color unevenness is likely to occur. Similar to visibility, even if the yellow color is strengthened, the value of the lightness index L obtained in Condition 1 or the value of Lightness Index L1 obtained in Condition 2 does not drop significantly, so color unevenness does not occur, but indigo colors are dark. In this case, color unevenness is easily noticeable.

  In this embodiment, when forming a pressure sensitive adhesive layer on both surfaces of a support body, a pressure sensitive adhesive layer is colored so that (DELTA) E calculated | required on the conditions 1 may be 2 or more. Preferably, ΔE is set to 3-50. When ΔE is less than 2, there is a problem that coloring is thin and design is poor.

  In the present embodiment, when a pressure-sensitive adhesive layer is formed on one side of the support and a non-pressure-sensitive adhesive layer is formed on the opposite side, the pressure-sensitive adhesive layer and the non-pressure-sensitive adhesive layer have ΔE1 obtained in Condition 2 and Each of them is colored so that ΔE2 is 2 or more. Preferably, ΔE1 is set to 3-50. When ΔE1 and ΔE2 are less than 2, there is a problem that coloring is thin and design is poor.

In this embodiment, as a criterion for determining the degree of color unevenness, in (Condition 3), it is preferable that at least 9 points out of 10 points of ΔE3 satisfy 0.2 or less in both of the front surface and the back surface. It is a practical lower limit that 9 points out of 10 points of ΔE3 satisfy 0.2 or less. If it is 8 points or less, it becomes easy to recognize color unevenness.
(Condition 3)
10 points along the width direction of the paper, 10 points every 5 mm, according to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", JIS Z 8730: 2009 "Color display method-Object color Both the front surface and the back surface are measured for the lightness index L and the perceptual chromaticity indices a and b defined by “color difference”. The measured values at 10 points are L, a, and b, respectively, and the average values at 10 points are Lx, ax, and bx. For each of 10 measured values, ΔE3 for 10 points is calculated according to Equation 4.
(Equation 4) ΔE3 = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )

  Examples of chromatic coloring pigments to be blended in the pressure-sensitive adhesive layer-forming coating solution and the non-pressure-sensitive adhesive layer-forming coating solution include organic pigments such as phthalocyanine pigments and azo pigments, oxide pigments, Examples thereof include inorganic pigments such as hydroxide pigments.

  In the present embodiment, the surfactant contained in the pressure-sensitive adhesive layer forming coating solution is limited to the nonionic surfactant. A surfactant is a uniform coating of a pressure-sensitive adhesive layer-forming coating solution on a substrate without color unevenness. If this is not used, even if the concentration is relatively light, uneven penetration will occur. And color irregularities such as repellency and damage to the appearance. In addition, these coating liquids often use strong ionic materials, so when an ionic surfactant is used, chromatic color pigments aggregate, which may cause color unevenness. Become. The compounding amount of the nonionic surfactant is not particularly limited, but preferably 0.1 to 8% by mass in the state of the pressure-sensitive adhesive layer after application and drying of the coating liquid for forming the pressure-sensitive adhesive layer. More preferably, it is 0.5 to 5% by mass.

  The pressure-sensitive adhesive layer-forming coating solution is mainly composed of a filler and a pressure-sensitive adhesive, but various materials can be selected in consideration of the quality required by the application and processing steps.

  As the inorganic filler, synthetic silica, titanium oxide, kaolin, clay, calcium carbonate, talc, plastic pigment, barium sulfate, aluminum hydroxide and the like may be used in combination as appropriate. Moreover, combined use with wheat starch having an average particle size of about 20 μm, for example, 12 to 24 μm, forms an uneven state with two peaks on the surface of the pressure-sensitive adhesive layer, while improving the re-peeling strength, while providing blocking resistance. Most preferably, the other average particle size is about 20 μm, for example, 12-24 μm starch, such as potato, tapioca, corn, or the like, or silica, kaolin, clay, talc, calcium carbonate, Aluminum hydroxide, titanium oxide, plastic pigment and the like can be used in combination as appropriate.

  As the pressure sensitive adhesive, synthetic natural rubber such as modified natural rubber, SBR, chloroprene rubber, acrylic resin having a low glass transition point, or the like can be used.

  In addition to the pressure-sensitive adhesive effect, oxidized starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, soy protein, synthetic protein, casein, etc., and vinyl acetate emulsions for the purpose of improving printing strength (surface strength) Further, methyl methacrylate / butadiene emulsion, styrene / butadiene emulsion, acrylic / butadiene emulsion and the like can be used in combination as long as the quality of the present invention is not impaired.

  The pressure-sensitive adhesive layer-forming coating solution may contain various additives. For improving the work during coating, leveling agents, antifoaming agents, antifoaming agents, and waxes to improve post-processing properties. In order to impart conductivity, fluorescent dyes, and so-called antistatic agents composed of surfactants or inorganic salts can be included. In addition, dispersants, printability improvers, lubricants, water repellents, penetrants, thickeners, anti-aging agents, ultraviolet absorbers, dyes, dye fixing agents, sizing agents, paper strength enhancers, as necessary Additives such as water retention agents, deodorants, preservatives, and antifungal agents can be used in combination as long as the quality of the present invention is not impaired.

  Moreover, as a material used for the non-pressure-sensitive adhesive layer forming coating solution, the same material as the pressure-sensitive adhesive layer forming coating solution can be used, and adjustment is performed so as not to be pressure-bonded during pressurization. The non-pressure-sensitive adhesive layer forming coating liquid may be mainly composed of a filler and an adhesive, or may be a clear liquid for coloring a color pigment and an adhesive. A nonionic surfactant is also contained in the non-pressure-sensitive adhesive layer forming coating solution. The amount of the nonionic surfactant to be blended in the non-pressure-sensitive adhesive layer forming coating solution is preferably in the state of the non-pressure-sensitive adhesive layer after coating and drying when the filler and the adhesive are mainly used. 0.1 to 8 mass%, more preferably 0.5 to 5 mass%. In the case of a clear liquid, the mixing ratio of the liquid is preferably 0.1 to 8% by mass, more preferably 0.5 to 5% by mass.

  The coating liquid for forming pressure-sensitive adhesive layer and the coating liquid for forming non-pressure-sensitive adhesive layer can be applied to common coaters such as air knife coater, roll coater, blade coater, rod blade coater, bar coater and die coater. Coated by.

  The support may be either single layer papermaking or multilayer papermaking. Examples of the pulp fiber that is the main element of the support include chemical pulp such as hardwood bleached kraft pulp (LBKP) and softwood bleached kraft pulp (NBKP), ground pulp (GP), pressurized ground pulp (PGW), refiner ground wood Pulp (RMP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemimechanical pulp (CMP), and other wood pulp such as waste paper pulp such as deinked pulp Is mentioned. Among them, it is particularly preferable to use NBKP, LBKP and a mixture thereof. By using exposed kraft pulp (BKP), the physical strength of the base paper can be ensured. In consideration of the balance with the stiffness of the paper, the use ratio (mass ratio) of NBKP and LBKP is preferably 9: 1 to 1: 9. More preferably, it is 8: 2 to 2: 8, and particularly preferably 6: 4 to 4: 6. In the case of multilayer papermaking, the pulp used in the middle layer may be composed only of wood pulp, but may also include recovered pulp (waste paper).

  The support may be mixed with various additives such as conventionally known fillers, binders, sizing agents, fixing agents, yield improvers, and paper strength enhancers as necessary. The support is prepared by mixing pulp fibers and the above-mentioned additives, and using a generally known paper machine such as a long net paper machine, a circular net paper machine, a twin wire paper machine, or a super ultraformer paper machine. It can be obtained by drying after forming a web with a paper machine. In addition, in this embodiment, it is not limited to the papermaking method of a base paper.

  In this embodiment, it is preferable that the support does not contain a colorant such as a color pigment and a color dye and is not colored. For example, JIS P 8148: 2001 “Paper, paperboard and pulp—ISO whiteness (diffuse blue) The whiteness according to “Measurement method of light reflectance” is preferably 78% or more. Rather than manufacturing colored substrates in many colors, applying a colored coating amount to an uncolored white substrate can cope with multicolor products at low cost in the manufacturing process.

  The present invention will be described with reference to the following examples and comparative examples, but the present invention is not limited to these examples. Note that “parts” and “%” shown in Examples or Comparative Examples indicate parts by mass and mass% unless otherwise specified.

Example 1
<Production of support>
5% titanium oxide (A-110: manufactured by Sakai Chemical Co., Ltd.), cationized starch (Kate 308: manufactured by NSC Japan) 0% to 100% absolute dry pulp in pulp slurry made of hardwood bleached kraft pulp L-BKP 8%, neutral rosin sizing agent (NT-85: Arakawa Chemical Co., Ltd.) 0.4%, wet paper strength enhancer 0.3% (WS-4020: Seiko PMC Co., Ltd.) A base paper having a whiteness according to 8148: 2001 of 82% and a weight of 110 g / m ² was made. The lightness index L and the perceptual chromaticity indices a and b defined by JIS Z 8730: 2009 were found to be Lx = 93.8, ax = −0.2, and bx = 2.7.

<Preparation of pressure-sensitive adhesive layer forming coating solution>
Fine seal X-60 (synthetic amorphous silica manufactured by Tokuyama Corporation) 100 parts by mass PVA-117 (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) 10 parts by mass Emulgen 709 (nonionic surfactant manufactured by Kao Corporation) 11 parts by mass Cybinol X-103 -204E (methyl methacrylate graft copolymer natural rubber) 100 parts by mass A paint having a concentration of 17.5% by mass was prepared with the above blending, and a color pigment (TB110-YELLOW2G manufactured by Dainichi Seika Co., Ltd.) was used in a weight ratio to the liquid. 0.25 part of this coating material was blended to obtain a coating solution for forming a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer-forming coating solution was applied on both sides of the support in a dry weight of 7 g / m ² (wet coating amount 40 g / m ² ), and a colored releasable pressure-sensitive adhesive recording paper was obtained.

(Example 2)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 1 except that the color pigment (TB110-YELLOW2G manufactured by Dainichi Seika Co., Ltd.) was changed to 1.0 part by mass with respect to the liquid weight in Example 1.

(Example 3)
In Example 1, a colored releasable pressure-sensitive adhesive recording sheet is obtained in the same manner as in Example 1 except that the color pigment is TB520 Blue 2B manufactured by Dainichi Seika Co., Ltd. and the blending amount is 0.038 parts by mass with respect to the liquid. It was.

Example 4
A colored releasable pressure-sensitive adhesive recording sheet was obtained in the same manner as in Example 3 except that the amount of TB520 Blue 2B in Example 3 was 0.094 parts by mass with respect to the liquid weight.

(Example 5)
A colored releasable pressure-sensitive adhesive recording sheet is obtained in the same manner as in Example 1 except that the color pigment is TB1100 RedFGN manufactured by Dainichi Seika Co., Ltd. and the blending amount is 0.02 parts by weight with respect to the liquid. It was.

(Example 6)
A colored removable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 5 except that the amount of TB1100 RedFGN in Example 5 was 0.08 parts by mass with respect to the liquid.

(Example 7)
In Example 1, the coloring pigments were TB520 Blue2B and TB110 Yellow2G manufactured by Dainichi Seika Co., Ltd., and the blending amounts were 0.025 parts by mass and 0.083 parts by mass, respectively. A colored releasable pressure sensitive adhesive recording paper was obtained.

(Example 8)
A colored releasable pressure-sensitive adhesive recording paper was prepared in the same manner as in Example 7 except that the mixing amounts of TB520 Blue2B and TB110 Yellow2G were 0.08 parts by mass and 0.28 parts by mass, respectively, in the liquid weight ratio. Obtained.

Example 9
A colored removable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 1 except that the blending amount of Emulgen 709 (non-ionic surfactant manufactured by Kao Corporation) in Example 1 was 1.5 parts by mass.

(Example 10)
<Preparation of non-pressure-sensitive adhesive layer forming coating solution>
Fine seal X-60 (synthetic amorphous silica manufactured by Tokuyama Corporation) 100 parts by mass PVA-117 (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) 20 parts by mass Emulgen 709 (non-ionic surfactant manufactured by Kao Corporation) 6 parts by mass AD-13 50 (ethylene vinyl acetate copolymer resin manufactured by Showa Polymer Co., Ltd.) 20 parts by mass A paint having a concentration of 17.5% by mass is prepared with the above composition, and a color pigment (TB110-YELLOW2G manufactured by Dainichi Seika Co., Ltd.) is used as a liquid weight. In comparison, 0.16 parts by mass with respect to 100 parts of the coating material was blended to obtain a non-pressure-sensitive adhesive layer forming coating solution. A non-pressure-sensitive adhesive layer-forming coating solution was applied to one side of the support by a dry weight of 7 g / m ² , and the pressure-sensitive adhesive layer-forming coating solution obtained in Example 1 was applied to the opposite surface by a dry weight. 7 g / m ^{2 was} applied to obtain a colored removable pressure-sensitive adhesive recording paper.

(Comparative Example 1)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 3 except that the coloring pigment, TB520 Blue 2B manufactured by Dainichi Seika Co., Ltd. was changed to 0.20 parts by mass with respect to the liquid weight.

(Comparative Example 2)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 3 except that the color pigment, TB520 Blue 2B manufactured by Dainichi Seika Co., Ltd. was used in an amount of 0.30 parts by weight.

(Comparative Example 3)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 5 except that the coloring pigment, TB1100 Red FGN manufactured by Dainichi Seika Co., Ltd. was used in an amount of 0.15 parts by weight to the liquid.

(Comparative Example 4)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 5 except that the color pigment, TB1100 RedFGN manufactured by Dainichi Seika Co., Ltd. was changed to 0.25 parts by weight with respect to the liquid.

(Comparative Example 5)
Colored re-peelable pressure in the same manner as in Example 7, except that the color pigment, TB520 Blue2B manufactured by Dainichi Seika Co., Ltd. was 0.15 parts by mass and TB110 Yellow2G was 0.33 parts by mass in Example 7. An adhesive recording paper was obtained.

(Comparative Example 6)
Colored releasable pressure-sensitive adhesive recording paper in the same manner as in Example 1 except that the color pigment in Example 1 was changed to TB510 BlackTR manufactured by Dainichi Seika Co., Ltd. and the blending amount was 0.021 parts by mass with respect to the liquid. Got.

(Comparative Example 7)
Colored releasable pressure-sensitive adhesive recording paper in the same manner as in Example 1 except that the color pigment in Example 1 was changed to TB510 Black TR manufactured by Dainichi Seika Co., Ltd., and the blending amount was 0.03 parts by mass with respect to the liquid. Got.

(Comparative Example 8)
A colored releasable pressure-sensitive adhesive recording paper was obtained in the same manner as in Example 4 except that the nonionic surfactant was not blended in Example 4.

(Comparative Example 9)
<Preparation of overcoat solution>
PVA-117 (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) 1 mass% solution, 0.09 parts by mass of TB520Blue2B was added to 100 parts by mass with respect to the liquid to obtain an overcoat solution.
<Preparation of pressure-sensitive adhesive layer forming coating solution>
Fine seal X-60 (synthetic amorphous silica manufactured by Tokuyama Corporation) 100 parts by mass PVA-117 (polyvinyl alcohol manufactured by Kuraray Co., Ltd.) 10 parts by mass Emulgen 709 (non-ionic surfactant manufactured by Kao Corporation) 8 parts by mass Cybinol X-103 -204E (methyl methacrylate graft copolymer natural rubber) 100 parts by mass A pressure-sensitive adhesive layer-forming coating solution having a concentration of 17.5% by mass was obtained with the above formulation. The pressure-sensitive adhesive layer-forming coating solution was applied to both sides of the support in a dry weight of 7 g / m ² (wet coating amount 40 g / m ² ), and then the overcoat solution was applied in a dry weight of 0.4 g on both sides. / M ² (wet coating amount 40 g / m ² ) was applied and colored.

(Comparative Example 10)
The pressure-sensitive adhesive layer-forming coating solution obtained in Comparative Example 9 was applied to both sides of the support by a dry weight of 7 g / m ² (wet coating amount 40 g / m ² ) to obtain a releasable pressure-sensitive adhesive recording paper. After that, color was applied by offset printing.

  Table 1 shows the evaluation results of the pressure-sensitive adhesive recording sheets obtained in the above examples and comparative examples.

<Evaluation method>
The obtained releasable pressure-sensitive recording paper was 23 ° C.-50% R.D. H. After the humidity was controlled in a constant temperature and humidity chamber for 24 hours, the evaluation was performed in the same environment by the following methods.

(1) Color difference of releasable pressure-bonded recording paper and (2) ΔE with support surface
According to the measurement method prescribed | regulated by JISZ8722: 2009, it obtained by an Example and a comparative example using the method calculated from the lightness index L of this surface prescribed | regulated by JISZ8730: 2009, and the perceptual color index a and b. The surface of the obtained releasable pressure-sensitive recording paper and the support was measured.
ΔE = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )
In addition, the measured value of the support surface: Lx, ax, bx
Measured values on the surface of the releasable pressure-sensitive recording paper in Examples and Comparative Examples: L, a, b
Note that Example 10 complies with Condition 2.

(3) Color unevenness evaluation According to the measurement method defined in JIS Z 8722: 2009, the method was calculated again using the method calculated from the lightness index L and the perceptual chromaticity index a and b of the surface defined in JIS Z 8730: 2009. Ten points were measured every 5 mm in the width direction of the peelable pressure-sensitive recording paper, and ΔE3 of 10 points was evaluated for 10 points on both the front and back, based on the average value. This corresponds to condition 3 above.
ΔE3 = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )
The average value of 10 measurement points: Lx, ax, bx
Values at each measurement point: L, a, b

The color unevenness evaluation is described in the following manner.
○ ΔE is 0.2 or less at 10 measurement points (practical level).
Δ ... ΔE is more than 0.2 at one measurement point, and the remaining 9 measurement points are 0.2 or less (practical level lower limit).
X: ΔE is 2 or more and more than 0.2, and the remaining measurement points are 0.2 or less (unsuitable).

(4) Confidential Information Visibility Cytex 1040 black ink for line printer ink jet printers was injected into the ink cartridge of an ink jet printer (HP DeskJet 560J, manufactured by Hewlett Packard) on the surface of the obtained releasable pressure-sensitive recording paper, and tested. Printing patterns (barcode, characters, solid) were printed, and the visibility of inkjet printing was evaluated. The lightness index L and the perceptual chromaticity indices a and b of the solid print portion were 32.5, 1, 2, 5.0.

(4-1) Visibility evaluation 1
Visually check the characters recorded by inkjet printing and evaluate the visibility,
A: Characters are clearly visible (practical level).
○: Characters can be visually recognized without problems (practical level).
Δ: Characters are a little difficult to see (unsuitable).
×: Characters are difficult to see (unsuitable).
And judged whether it was good, good, impossible or inferior.
(4-2) Visibility evaluation 2
ΔE = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )
Measured value of Cytex ink 1040 solid printing part: Lx, ax, bx
Measured values on the surface of the releasable pressure-sensitive recording paper of Examples and Comparative Examples: L, a, b
○ Good: When the lightness index L of the releasable pressure-sensitive recording paper obtained in Examples and Comparative Examples is 88 or more, and ΔE between the Cytex ink printing portion and the releasable pressure-sensitive recording paper is 60 or more, it is colored. Even if it was, it was judged that visibility was favorable.
× Impossible: Coloring was applied when the lightness index L of the releasable pressure-sensitive recording paper obtained in Examples and Comparative Examples was less than 88 and ΔE between the Cytex ink printed portion and the releasable pressure-sensitive recording paper was less than 60. Therefore, it was difficult to determine the confidential information, and it was determined that the visibility was not possible.

(5) Economic evaluation It evaluated from the chemical cost and productivity of the coating liquid.
The chemical cost and productivity evaluation of the coating solution were described in the following manner.
○: An additional process for coloring is not required, and profitability level (practical level).
X: An additional step for coloring is necessary, and it is not profitable (unsuitable).

(6) Peel strength test The obtained releasable pressure-sensitive recording paper is cut into a width of 100 mm and a length of 100 mm, the coated surfaces are overlapped with each other, and a gap is formed using a dry sealer (Pressle Econo: manufactured by Toppan Foams). Pressure bonding was performed at 0.20 mm. Next, the width direction center part of this sample was cut | judged to 25 mm width, and 23 degreeC and 50% R. H. Peel strength gf / 25mm is obtained by peeling with a strograph M-1 type (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a speed of 300 mm / min and a peel angle of 90 ° (T-type peel) and averaging the resistance values. .
◯: The peel strength is at a practical level for 100 to 200 gf / 25 mm.
(Triangle | delta): 50 or more-less than 100gf / 25mm has a weak peeling strength, and does not reach a practical minimum.
X: 0 or more to less than 50 gf / 25 mm is unsuitable for practical use because of low peel strength.

(7) Whiteness The whiteness of the releasable pressure-sensitive recording paper obtained in the Examples and Comparative Examples was measured by a method according to JIS P 8148: 2001.

  As shown in Table 1, the releasable pressure-sensitive recording sheets of Examples 1 to 10 of the present invention are excellent in visibility of confidential information even if they are colored, and are uniform and free of color unevenness, such as direct mail. If applied to the above, it is possible to meet the needs of society that have not existed before, and to create a commercial value that is not found in general releasable pressure-sensitive recording paper at a low cost.

  On the other hand, it can be seen that Comparative Examples 1 to 10 are inferior in color unevenness, visibility of confidential information, production cost, crimping performance, and the like. In addition, when coloring is performed from Table 1, it can be seen that the decrease in whiteness does not affect the visibility of confidential information, but is greatly influenced by the brightness index L.

Claims (6)

Removable pressure-sensitive adhesive recording with a pressure-sensitive adhesive layer formed on both sides of the support that does not exhibit tackiness and adhesiveness under normal conditions of normal temperature and normal pressure, but exhibits adhesiveness when pressed and can be re-peeled after pressure bonding In paper
The pressure-sensitive adhesive layer contains a nonionic surfactant and a chromatic color pigment, and is colored so that ΔE obtained in condition 1 is 2 or more,
A chromatic colored releasable pressure-sensitive recording sheet, wherein the lightness index L obtained under Condition 1 of the pressure-sensitive adhesive layer is 88 or more.
(Condition 1)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support and the surface of the pressure-sensitive adhesive layer are measured. The measured values of the surface of the support are Lx, ax, bx, and the measured values of the surface of the pressure-sensitive adhesive layer are L, a, b. ΔE is calculated by Equation 1.
(Equation 1) ΔE = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² ) A pressure-sensitive adhesive layer is formed on one side of the support that does not exhibit tackiness or adhesiveness under normal conditions of normal temperature and normal pressure, exhibits adhesiveness when pressed, and can be peeled again after pressure bonding. In the releasable pressure-sensitive adhesive recording paper formed by forming a non-pressure-sensitive adhesive layer on the surface,
The pressure-sensitive adhesive layer and the non-pressure-sensitive adhesive layer contain a nonionic surfactant and a chromatic color pigment, and are colored so that ΔE1 and ΔE2 obtained under condition 2 are both 2 or more. And
A chromatic colored releasable pressure-sensitive recording sheet, wherein the lightness index L1 obtained under Condition 2 of the pressure-sensitive adhesive layer is 88 or more.
(Condition 2)
According to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", according to the measurement method JIS Z 8730: 2009 "Color display method-Color difference of object color", Lightness index L, Perceptual chromaticity index For a and b, the surface of the support, the surface of the pressure-sensitive adhesive layer, and the surface of the non-pressure-sensitive adhesive layer are measured. The measured value of the surface of the support is Lx, ax, bx, the measured value of the surface of the pressure-sensitive adhesive layer is L1, a1, b1, and the measured value of the surface of the non-pressure-sensitive adhesive layer is L2, a2, b2, ΔE1 is calculated by Equation 2, and ΔE2 is calculated by Equation 3.
(Equation 2) ΔE1 = √ ((Lx−L1) ² + (ax−a1) ² + (bx−b1) ² )
(Equation 3) ΔE2 = √ ((Lx−L2) ² + (ax−a2) ² + (bx−b2) ² ) 3. The chromatic colored releasable pressure-sensitive recording sheet according to claim 1, wherein at least 9 points out of 10 of ΔE3 satisfy 0.2 or less in both of the front and back surfaces in (Condition 3) .
(Condition 3)
10 points along the width direction of the paper, 10 points every 5 mm, according to JIS Z8722: 2009 "Color measurement method-Reflection and transmission object color", JIS Z 8730: 2009 "Color display method-Object color Both the front surface and the back surface are measured for the lightness index L and the perceptual chromaticity indices a and b defined by “color difference”. The measured values at 10 points are L, a, and b, respectively, and the average values at 10 points are Lx, ax, and bx. For each of 10 measured values, ΔE3 for 10 points is calculated according to Equation 4.
(Equation 4) ΔE3 = √ ((Lx−L) ² + (ax−a) ² + (bx−b) ² )   The chromatic colored releasable pressure-sensitive recording sheet according to any one of claims 1 to 3, wherein the chromatic color pigment is nonionic.   The chromatic colored releasable pressure-sensitive recording paper according to any one of claims 1 to 4, wherein the support does not contain a colorant. A method for producing a chromatic colored releasable pressure-sensitive recording paper according to any one of claims 1 to 5,
A step of preparing a coating liquid containing the nonionic surfactant and the chromatic coloring pigment; and coating the coating liquid on a surface of the support to form the pressure-sensitive adhesive layer or the non-sensitive layer. A method for producing a chromatic colored releasable pressure-sensitive recording sheet, comprising forming a pressure-bonding layer.