JPH04250092A - Recording sheet - Google Patents

Abstract

PURPOSE:To obtain a recording sheet suitable for a large-size ink jet recording using aqueous ink with a water resistance and strength sufficient for the use in the open air and superior ink glossiness, ink smoothness, and ink absorptivity. CONSTITUTION:On a substrate of a film base, a coating layer mainly composed of a pigment and an adhesive is provided. The coating layer contains 20-70% needle rhombic aragonite calcium carbonate having an oil absorptiveness of 30-55ml/100g as the pigment component and an epoxy resin and a thermoplastic resin as the adhesive component.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a water-based ink that has water resistance strength that can withstand harsh environmental conditions, especially outdoor use, and has excellent ink gloss, smoothness, ink absorption, and drying properties. The present invention relates to a large-sized inkjet recording sheet using.

0002

2. Description of the Related Art Inkjet recording systems are used in a wide variety of applications, such as in various printers, because they generate less noise, can perform high-speed recording, and can easily produce multiple colors. In particular, images formed using the multicolor inkjet recording method are comparable to normal multicolor printing, and are cheaper than the normal multicolor platemaking method or color photographic printing method for large posters that are produced in small numbers. It is attracting attention because it can be manufactured in

By the way, recording sheets used in this multicolor inkjet recording method, such as high-quality paper or coated paper used in general printing, are paper-based, so they are susceptible to changes in humidity, rainfall, etc. It cannot be used for outdoor posters as it is susceptible to damage.

[0004] In addition, baryta paper used as a support for photographic paper has its water resistance improved by adding wet paper strength agents to the base paper, but gelatin, casein, etc. used in the coating layer are Due to its poor water resistance, it is not suitable for outdoor use.

[0005] In this respect, synthetic paper has excellent water resistance, but
Because it has poor ink absorbency, if this is used as an inkjet recording sheet, the image will be smeared with residual ink. Especially in the case of multi-color recording, two
- Since the ink dots of four colors overlap, the amount of ink is large, resulting in problems such as ink being mixed without being absorbed or flowing out, which is not practical.

It has also been proposed to use a coated sheet in which a pigment coating layer used in conventional ink jet recording paper is formed on a synthetic film. For example, JP-A-58-1102
Japanese Patent No. 87 discloses a method in which the outermost layer, which the ink contacts first, is composed of pigment particles having an appropriate size so that the pore distribution curve has two peaks.

[0007] Also, in Japanese Patent Application Laid-Open No. 1-95092,
A method is disclosed in which secondary particles of silica having a large specific surface area are used as a white pigment in the coating layer.

However, these methods do not provide sufficient ink gloss or ink smoothness, resulting in only dull recorded images compared to multicolor printing using ordinary printing inks. Moreover, the color reproducibility is also poor, so that satisfactory results are not necessarily obtained.

[0009]

[Problems to be Solved by the Invention] In view of the current situation, the present inventors have focused particularly on inkjet recording sheets in which a pigment coating layer is formed on a film support, and as a result of intensive research into improving the above-mentioned drawbacks, When calcium carbonate having a specific oil absorption amount and shape is used as a pigment constituting the pigment coating layer, the gloss and smoothness of the ink during recording can be effectively improved. It has become clear that when pigments are used in combination, the ink absorbency and drying properties can be easily adjusted, and especially with calcined kaolin, these improving effects can be achieved in an extremely well-balanced manner. Furthermore, the inventors have also discovered that the water resistance and adhesive strength of the coated layer can be improved by using a specific resin as an adhesive without impairing this balance effect, leading to the completion of the present invention.

0010

[Means for Solving the Problems] The present invention provides the following methods: (a) having an oil absorption of 30 to 55 ml/1 on a film-based support;
00g of needle-shaped orthorhombic aragonite calcium carbonate in the total pigment in an amount of 20 to 70% by weight, and (b)
This is a recording sheet characterized by forming a coating layer containing an epoxy resin and (c) a thermoplastic resin.

[0011]

[Operation] The recording sheet of the present invention is suitable for large-sized inkjet recording. An example of a large-sized inkjet printer is a multicolor enlarging printing device devised by Nippon Enlarged Color Co., Ltd. and manufactured by Matsushita Electric Power Co., Ltd., for example. This device has a color separation control unit and a recording unit that has a large drum with a diameter of 1.5 m and a length of 3 m. Recording is performed while controlling the amount of ink ejected by adjusting the solenoid valve of the ink ejecting spray gun. Approximately 15 to 30 minutes of recording time is required to complete a large screen of 3 x 4 m, but since the screen is large, the recording sheet can be used for outdoor advertising posters and the like.

However, for such uses, quality characteristics different from those of general office inkjet recording paper are required. For example, weather resistance that can withstand outdoor use is required, and in particular water resistance against rain and wind and rain is required. is important. Also,
In order for the finished print to have sufficient visual appearance and excellent color characteristics, the sheet surface must have whiteness, gloss, shine, smoothness, etc. before recording, and the ink gloss, shine, and smoothness of the recorded image must be maintained.
Ink smoothness is also important.

As a result of intensive research based on these various quality requirements, the inventors of the present invention have developed the above structure by appropriately selecting the composition and shape of the pigment constituting the pigment coating layer, as well as the adhesive. This is the completed invention consisting of the following.

[0014] In the recording sheet of the present invention, the pigment constituting the pigment coating layer has an oil absorption amount of 30 to 55 ml/
100 g of aragonite calcium carbonate having a needle-like orthorhombic crystal form is used. This calcium carbonate is precipitated light calcium carbonate. For example, Okutama Kogyo Co., Ltd. sells various products under the trade name Tama Pearl, which has a specific gravity of 2.93 and a Mohs hardness of 3.5.
~4.0, refractive index Nx 1.530, Ny 1.631
, orthorhombic crystals with Nz 1.685 are commercially available. According to electron microscopy, the length of the long side of the needle-shaped particles (
L) is about 0.3 to 3 μm, and the short side length (W) is 0.0
Approximately 2 to 0.3 μm, aspect ratio (L/W) is 2 to 0.3 μm
It is about 20.

[0015] In the present invention, the oil absorption amount of this calcium carbonate is also an important factor, and JIS K-51
Calcium carbonate with an oil absorption of less than 30 ml/100 g as measured in accordance with 01 will reduce the ink smoothness of the recording sheet, and conversely, if it exceeds 55 ml/100 g, the ink gloss will decrease. Calcium carbonate with an oil absorption of 100 g is selectively used.

[0016] Moreover, this calcium carbonate accounts for 20% of the total pigment.
It needs to be contained in the coating layer in an amount of 70% by weight, and if it is outside this range, delicate quality control of the recording sheet becomes difficult and the desired effect of the present invention cannot be achieved.

[0017] In the recording sheet of the present invention, such specific calcium carbonate has an oil absorption of 80 ml/10
0g or more, more preferably 80-150ml/100g
When oil-absorbing pigments such as calcined kaolin, magnesium carbonate, magnesium silicate, titanium oxide, zinc oxide, satin white, silicon oxide, alumina, and plastic pigments are used together in a proportion of 30 to 80% by weight of the total pigment,
The resulting recording sheet has a better balance of ink gloss, smoothness, ink absorption, ink drying properties, etc., and especially when used in combination with calcined kaolin, which has an oil absorption of 80 to 120 ml/100 g, it has a good balance of ink gloss, smoothness, ink absorption, and ink drying properties, which is necessary for large-sized inkjet recording sheets. It has become clear that quality can be improved extremely efficiently.

The reason why such an effect is obtained is not clear, but it is presumed that the needle-shaped particles of calcium carbonate and the hexagonal plate-shaped particles of calcined kaolin are well dispersed and mixed together to exert a synergistic effect.

Furthermore, in the present invention, in addition to the above-mentioned specific needle-shaped orthorhombic aragonite calcium carbonate and the specific oil-absorbing pigment, general coating pigments can also be used in combination, if necessary. Such pigments include, for example, precipitated calcium carbonate, ground calcium carbonate, kaolin, calcined kaolin, talc, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, aluminum hydroxide. , diatomaceous earth, magnesium silicate, alumina, lithopone, and other inorganic pigments, plastic pigments, and organic fine particles such as microcapsules.

[0020] In the recording sheet of the present invention, an epoxy resin and a thermoplastic resin are particularly used in combination as an adhesive constituting the coating layer together with the pigment as described above. By using these adhesives together, the water resistance, adhesive strength, etc. of the coated layer can be maintained appropriately without impairing the balance effects such as excellent ink gloss and absorbency obtained by using special pigments. be.

[0021] Although it is not clear how they interact when used in combination, the use of an epoxy resin alone results in insufficient adhesive strength, and the use of a thermoplastic resin alone results in insufficient water resistance.

The epoxy resin used in the present invention is a compound having two or more highly reactive epoxy groups in its molecule, and preferably a water-soluble epoxy compound produced by glycidylation from epichlorohydrin. used.

Specific examples include glycols, di- or polyglycidyl ethers of aliphatic polyhydric alcohols, diglycidyl esters of dicarboxylic acids, and epoxy compounds having a nitrogen-containing heterocycle.
For example, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether [n=5, 9, 13, 23
etc.], propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether [n=3,7,
11 etc.], glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether,
Succinic acid diglycidyl ester, adipic acid diglycidyl ester, diglycidyl dimethyl hydanthrene, glycidyl trimethyl ammonium chloride, furfuryl glycidyl ether, trimethylolethane triglycidyl ether, 3-methylpentanetriol triglycidyl ether, polyglycerin triglycidyl ether, Examples include glycerin ethylene oxide triglycidyl ether, but two or more of these may of course be used in combination.

The amount of the above-mentioned epoxy resin used is adjusted within the range of 1 to 40 parts by weight, more preferably 1 to 25 parts by weight, based on 100 parts by weight of the pigment constituting the coating layer. If the amount used is less than 1 part by weight, the water resistance of the resulting coating layer will be insufficient, and if it exceeds 40 parts by weight, the ink absorbency may decrease.

Specific examples of thermoplastic resins used in combination with epoxy resins include conjugated diene polymer latexes such as styrene/butadiene copolymer latex and/or methyl methacrylate/butadiene copolymer latex; ) Acrylic polymer latex such as acrylic acid ester polymers and copolymers, vinyl polymer latex such as ethylene/vinyl acetate copolymer, and functionalized polymers with functional groups such as carboxyl groups introduced into these various polymers. Group-modified polymer latex, polymethyl methacrylate,
Examples include synthetic resin adhesives such as polyurethane resins, unsaturated polyester resins, vinyl chloride/vinyl acetate copolymers, polyvinyl butyral, alkyd resins, and maleic anhydride resins.

Among these thermoplastic resins, conjugated diene polymer latexes such as styrene/butadiene copolymer latex and/or methyl methacrylate/butadiene copolymer latex have a high interaction with the epoxy resin used in combination. It is preferable because it has excellent properties. In particular, the butadiene content is 30 to 30% of the total solid content of the conjugated diene copolymer.
Preferably it is 40% by weight.

Furthermore, the gel content of the styrene-butadiene copolymer latex is 30 to 85% of the total solid content of the copolymer.
The copolymer latex in the range of 40 to 70% by weight, more preferably 40 to 70% by weight, improves the water resistance strength, adhesive strength, and adhesive strength of the coating layer.
It is most preferably used because it has an excellent effect of improving ink absorption.

The amount of thermoplastic resin to be used is appropriately adjusted depending on the type of thermoplastic resin and the type of epoxy resin used together, but generally it is 2 to 2 parts by weight per 100 parts by weight of the pigment constituting the coating layer. It is adjusted to about 45 parts by weight, preferably about 5 to 30 parts by weight. The ratio of the epoxy resin to the thermoplastic resin is preferably 0.3:30 to 4:1, more preferably 1:30 to 3:1.

[0029] If the total amount of thermoplastic resin and epoxy resin used exceeds 50 parts by weight per 100 parts by weight of pigment, there is a risk that the ink absorbency will decrease, so the combined amount of both should take this point into account. It is desirable to make a decision based on

The interaction between the special pigment, epoxy resin, and thermoplastic resin that constitutes the coating layer is not clear, but the epoxy group of the epoxy resin and the hydroxyl group, carboxyl group, carbonyl group, etc. of the thermoplastic resin are carbonated. It is presumed that calcium reacts efficiently in the presence of calcium and forms crosslinks when the coated layer is heated and dried, giving it excellent water resistance and adhesive strength.

[0031] In the pigment coating liquid forming the coating layer,
If necessary, various auxiliary agents such as dispersants, thickeners, flow modifiers, antistatic agents, waterproofing agents, antifoaming agents, foam inhibitors, mold release agents, coloring agents, foaming agents, etc. are added as appropriate. You may do so.

A film-based support is used as the support constituting the recording sheet of the present invention. Specific examples include thermoplastic resin films such as polyester, polystyrene, polyvinyl chloride, polymethyl methacrylate, cellulose acetate, polyethylene, polypropylene, polycarbonate, etc., but are not limited to these. In addition, thermoplastic resin films are not limited to transparent films, but include titanium oxide, calcium carbonate,
It may be an opaque film filled with a white pigment such as calcium sulfate, silica, clay, talc, zinc oxide, etc., or made white by providing fine foam.

[0033] Further, in order to reinforce the above-mentioned film, it may be a composite sheet made by laminating materials with excellent water resistance such as non-woven fabrics and woven fabrics.

[0034] The thickness of the film and composite sheet is as follows:
Generally, it is adjusted in the range of about 10 to 2000 μm,
Of course, it is not limited to this range.

The above-mentioned pigment coating layer is coated on the film surface of such a film-based support, and examples of the coating machine include a blade coater, an air knife coater, a roll coater, a brush coater, Ordinary coating machines such as a curtain coater, die coater, bar coater, gravure coater, and spray coater are used as appropriate.

[0036] The coating amount of the pigment coating layer is generally 2 to 60 g.
/m2, preferably in the range of about 5 to 40 g/m2, but if the coating amount is too small, the ink absorbency will decrease, and if it is too large, the ink gloss will decrease. Incidentally, an intermediate layer may be provided to improve the adhesion between the film base and the pigment coating layer, if necessary.

As a drying method for the pigment coating layer, steam heating, hot air heating, gas heater heating, electric heater heating, infrared heater heating, high frequency heating, laser heating, electron beam heating, etc. are used as appropriate. It is desirable to adjust the surface temperature depending on the material.

The recording sheet thus obtained by forming the coating layer on the support can be used as is, but the surface may be smoothed using, for example, a super calender, a gloss calender, or the like. However, since excessive smoothing treatment may have a negative effect on suitability such as ink absorbency, it is desirable to adjust the treatment conditions as appropriate.

It is also possible to form a durable sheet by providing a pigment coating layer on the above film and subjecting it to smoothing treatment, and then laminating non-woven fabric, woven fabric, etc. on the non-coated surface.

[0040] It is also possible to apply an adhesive treatment to the back side of the recording sheet and finish it as a so-called tacked sheet. In this case, the adhesive treatment to the support is performed prior to coating the pigment coating layer. You can also do that.

[0041] In addition, it is of course possible to perform various finishing treatments and processing treatments that are practiced in the art, such as surface treatments such as antistatic treatment and treatment to impart writing suitability (printability) to the back side of the sheet. It is also possible to incorporate auxiliary agents such as ultraviolet absorbers and antioxidants into arbitrary positions of the sheet to improve the storage stability of recorded images.

[0042]

[Examples] The present invention will be explained in more detail with reference to Examples below, but it is of course not limited thereto. In addition, unless otherwise specified, parts and % in the examples indicate parts by weight and % by weight, respectively.

Example 1 Oil absorption amount is 40ml/100g and aspect ratio (L/W)
0.3 part of sodium polyacrylate was added to 50 parts of needle-shaped orthorhombic aragonite calcium carbonate having a diameter of 8, and 50 parts of calcined kaolin (trade name: Ancilex, oil absorption 110 ml/100 g, manufactured by EMC), and mixed with a stirrer. A pigment slurry having a solid content concentration of 50% was prepared.

[0044] To this pigment slurry, 4 parts of epoxy resin (trade name: Denacol EX810, manufactured by Nagase Sangyo Co., Ltd.) and styrene-butadiene with a butadiene content of 34% and a gel content of 54% were added as solid components. System copolymer latex (product name: T-1242, manufactured by Nippon Zeon Co., Ltd.)
A pigment coating liquid was prepared by adding 20 parts of antistatic agent, 3 parts of antistatic agent, and 4 parts of zirconium ammonium carbonate, and adjusting the solid content concentration with water to 45%.

[0045] This coating liquid was coated on one side of polypropylene synthetic paper (trade name: Yupo FPG-150, manufactured by Oji Yuka Co., Ltd.) using a bar coater so that the dry weight was 20 g/m2, and then heated with hot air at 60°C. It was dried in a dryer for 30 seconds to produce a recording sheet.

Example 2 The same procedure as in Example 1 was carried out, except that as the calcium carbonate, needle-shaped orthorhombic aragonite calcium carbonate having an oil absorption of 55 ml/100 g and an aspect ratio (L/W) of 13 was used. A recording sheet was manufactured.

Example 3 Example 1 except that needle-shaped orthorhombic aragonite calcium carbonate having an oil absorption of 32 ml/100 g and an aspect ratio (L/W) of 8 was used as the calcium carbonate.
A recording sheet was produced in the same manner as above.

Comparative Example 1 The same procedure as in Example 1 was carried out except that as the calcium carbonate, needle-shaped orthorhombic aragonite calcium carbonate having an oil absorption of 25 ml/100 g and an aspect ratio (L/W) of 10 was used. A recording sheet was manufactured.

Example 4 A recording sheet was produced in the same manner as in Example 1, except that the blending ratios of acicular orthorhombic aragonite calcium carbonate and calcined kaolin were changed to 65 parts and 35 parts, respectively.

Example 5 A recording sheet was produced in the same manner as in Example 1 except that the blending ratios of acicular orthorhombic aragonite calcium carbonate and calcined kaolin were changed to 30 parts and 70 parts, respectively.

Example 6 A recording sheet was produced in the same manner as in Example 1, except that fine powder alumina (manufactured by Mizusawa Chemical Co., Ltd.) having an oil absorption of 105 ml/100 g was used instead of calcined kaolin.

Example 7 Pigments include 40 parts of acicular orthorhombic aragonite calcium carbonate having an oil absorption of 40 ml/100 g and an aspect ratio (L/W) of 8, and calcined kaolin (trade name: Ancilex, oil absorption of 110 ml). /100g, manufactured by EMC) 4
0 parts, titanium oxide (product name: FA-55W, oil absorption 23
A pigment coating liquid was prepared in the same manner as in Example 1, except that the amount was changed to 20 parts (ml/100g, manufactured by Furukawa Kikai & Metals Co., Ltd.).

[0053] This coating liquid was applied to a white foamed polyethylene terephthalate film (trade name: Diafoil W-900).
-E #100, manufactured by Diafoil Co., Ltd.) with a bar coater to a dry weight of 25 g/m2.
A recording sheet was produced by drying for 30 seconds in a hot air dryer at 60°C.

Example 8 Pigments include 50 parts of acicular orthorhombic aragonite calcium carbonate having an oil absorption of 55 ml/100 g and an aspect ratio (L/W) of 13, and calcined kaolin (trade name: Ancilex, oil absorption of 110 ml). /100g, manufactured by EMC)
25 parts, kaolin (product name: UW-90, oil absorption 40m)
A pigment coating liquid was prepared in the same manner as in Example 1, except that 25 parts of 1/100 g (manufactured by EMC) were used.

[0055] This coating liquid was applied to a polyethylene terephthalate film and a nonwoven fabric (trade name: Marix 70200W).
SO, manufactured by Unitika) was coated with a bar coater on one side of the polyethylene terephthalate film side of a sheet laminated with molten polyethylene to a dry weight of 25 g/m2, and dried for 30 seconds in a hot air dryer at 60°C. A recording sheet was manufactured.

Comparative Example 2 A recording sheet was produced in the same manner as in Example 1 except that the blending ratio of acicular orthorhombic aragonite calcium carbonate was 100 parts and that calcined kaolin was not used.

Comparative Example 3 A recording sheet was produced in the same manner as in Example 1, except that the calcined kaolin content was 100 parts and calcium carbonate was not used.

Comparative Example 4 A recording sheet was produced in the same manner as in Example 1, except that spindle-shaped calcite calcium carbonate with an oil absorption of 47 ml/100 g was used instead of the needle-shaped orthorhombic aragonite calcium carbonate. .

Example 9 A recording sheet was produced in the same manner as in Example 1, except that the amount of epoxy resin (trade name: Denacol EX810, manufactured by Nagase Sangyo Co., Ltd.) was changed to 20 parts.

Comparative Example 5 A recording sheet was produced in the same manner as in Example 1, except that the amount of epoxy resin (trade name: Denacol EX810, manufactured by Nagase Sangyo Co., Ltd.) was 0.5 parts.

Example 10 Styrene/butadiene copolymer latex was converted into methyl methacrylate/butadiene copolymer latex (trade name: P-0X55P) with a butadiene content of 31%.
A recording sheet was produced in the same manner as in Example 1, except that the material was replaced with (manufactured by Sumitomo Naugatuck Co., Ltd.).

Example 11 Styrene-butadiene copolymer latex with a butadiene content of 41% and a gel content of 90% (trade name: L-1)
A recording sheet was produced in the same manner as in Example 1 except that the material was replaced with 571 (manufactured by Asahi Kasei Co., Ltd.).

Example 12 Styrene-butadiene copolymer latex was converted into acrylic polymer latex (trade name: Acronal YJ-27).
A recording sheet was produced in the same manner as in Example 1, except that the material was replaced with 41D (manufactured by Mitsubishi Yuka Verdeish Co., Ltd.).

Comparative Example 6 Oil absorption amount 40ml/100g and aspect ratio (L/W) 8
Needle-shaped orthorhombic aragonite calcium carbonate 5
Ultrafine particle silica (0 parts, oil absorption 150ml/100g)
0.5 part of sodium polyacrylate was added to 50 parts of Mizukashiru P527 (trade name, manufactured by Mizusawa Chemical Co., Ltd.) and dispersed with a stirrer to prepare a pigment slurry with a solid content concentration of 40%.

To this pigment slurry, 15 parts of polyvinyl alcohol (trade name: PVA117, manufactured by Kuraray Co., Ltd.) aqueous solution (
A pigment coating liquid was prepared by adding solid content) and adjusting the solid content concentration to 20% with water. A recording sheet was produced in the same manner as in Example 1 except that this coating liquid was used.

The characteristics of the 18 types of recording sheets thus obtained were evaluated using the following evaluation method, and the results are shown in the table.

[Water Resistance Strength] After the sample was immersed in water for 24 hours, the surface of the coating layer was rubbed 10 times using the fingertip method, and the degree of shedding of the coating layer was evaluated using the following evaluation criteria. ■: The coating layer was not removed at all and was very strong. ■: The coating layer could not be removed, but was slightly slippery. ■: The coating layer was slightly removed, but there is no problem in practical use. ■: The coating layer is removed, which is a practical problem. ■: A large amount of the coating layer was removed and it was weak. ■: The coating layer was removed from the first coat and was extremely weak.

[Ink gloss] Four colors of water-based ink, yellow, magenta, cyan, and black, are printed using a large inkjet multicolor enlarging printing device devised by Nippon Enraging Color Co., Ltd., and the ink gloss after drying is determined as Gross.
It was measured at an angle of 60° (%) using Meter GM-3D (manufactured by Murakami Color Research Institute). The higher the value, the better the gloss.

[Ink smoothing] Print in the same manner as above,
The ink smoothness after drying was measured using a smoother smoothness meter (manufactured by Toei Electronics Co., Ltd.) (cmHg). The smaller the value, the better the smoothness.

[Ink absorption time] When printing was performed in the same manner as above, the time (minutes) until the aqueous ink on the surface of the recording layer was absorbed and the change in surface gloss disappeared was measured.

[0071]

[Table 1]

[0072]

[Effects of the Invention] As is clear from the results in the table, the recording sheet of the present invention is well-balanced in all evaluations of water resistance strength, ink gloss, ink smoothness, and ink absorption time, and has excellent quality characteristics. was.

However, if the oil absorption amount of the needle-shaped orthorhombic aragonite calcium carbonate is too small (Comparative Example 1), the ink gloss, ink smoothness, ink drying property, etc. will decrease, and the blended amount of aragonite calcium carbonate will not exceed the specified amount. If it comes off (
Comparative Example 2) Ink drying properties are decreased, and (Comparative Example 3) Ink gloss and ink smoothness are decreased.

[0074] Also, if the amount of epoxy resin blended is small (
Comparative Example 5) The water resistance strength was decreased, and in the formulation example (Comparative Example 6) in which the adhesive composition was different, the water resistance strength, ink gloss, and ink smoothness were significantly decreased.

Claims (5)

[Claims] 1. On a film-based support, (a) acicular orthorhombic aragonite calcium carbonate having an oil absorption of 30 to 55 ml/100 g is present in an amount of 20 to 70% of the total pigment;
A recording sheet comprising a coating layer containing (b) an epoxy resin and (c) a thermoplastic resin. Claim 2: The coating layer further has an oil absorption amount of 80ml/100
2. The recording sheet according to claim 1, wherein the recording sheet contains an oil-absorbing pigment of 30 to 80% by weight of the total pigment. Claim 3: The oil-absorbing pigment has an oil absorption amount of 80 to 120 ml/1.
The recording sheet according to claim 2, which is 00g of calcined kaolin. 4. The recording sheet according to claim 1, wherein the content of the epoxy resin is 1 to 40 parts by weight based on 100 parts by weight of the pigment forming the coating layer. 5. A claim in which the thermoplastic resin is a styrene-butadiene copolymer, the butadiene content is 40% by weight or less of the total solids of the copolymer, and the gel content is 30 to 85% by weight. Recording sheet according to items 1 to 4.