JPH01280581A - Ink recording sheet - Google Patents

Abstract

PURPOSE:To ensure an excellent receptivity for water-based inks and make it possible to obtain clear line images with high density, by providing a layer comprising a polyoxyethylene-polyoxypropylene block compolymer type surfactant and a water-soluble polymer, on at least one side of a transparent support. CONSTITUTION:A mixture of a surfactant having a polyoxypropylene as a hydrophobic group in the molecule thereof and a polyoxyethylene as a hydrophilic group at both terminals thereof with a water-soluble polymer such as polyvinyl alcohol is dissolved or dispersed in water or an appropriate organic solvent to prepare a coating liquid. The coating liquid is applied to at least one side of a transparent support such as a polyester resin film, followed by drying to provide an ink-receiving layer. The recording sheet thus obtained has an excellent receptivity for water-based inks, and gives clear line images with high density. Also, the recording sheet gives an ink record with excellent resolution and color reproducibilities and high image quality.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an ink recording sheet using water-based ink, particularly for inkjet recording that has excellent depiction of line images such as characters and excellent light transmittance. It concerns the seat.

(Prior technology) Ink chef) Recording is noiseless and allows high-speed recording, and has been adopted in terminal printers, etc., and has rapidly become contradictory in recent years. Furthermore, by using a large number of ink nozzles, it is easy to perform multicolor recording, and multicolor inkjet recording using various inkjet recording methods is being considered.

In recent years, in particular, the use of inkjet printers, which can quickly and accurately form complex images, has been attracting attention as a device for creating hard copies of computer-generated image information such as characters and various figures. Furthermore, there is an increasing demand for recording image information created by a computer on a transparent ink recording sheet using an inkjet printer and using this as a manuscript for OHP (overhead projector) and the like.

In addition to inkjet printing, ink recording sheets are also used for plotters and handwriting using water-based inks.

From the standpoint of safety and recording properties, water-based inks containing water as a main component are mainly used as recording inks for these inks, and polyvalent inks are used to prevent clogging of pens and nozzles and to improve ejection properties. Alcohol etc. are often added.

Conventionally, as the ink recording sheet, a recording sheet formed by providing a porous ink absorbing layer on a support called ordinary paper or ink recording paper has been used.

However, there are several problems when using these conventional recording sheets as OHP originals. That is, these recording sheets usually have poor light transmittance, and even in the case of transparent recording sheets, their aqueous ink receptivity is poor.

That is, most conventional recording sheets use a method in which a porous ink absorbing layer is provided on the surface, and ink is absorbed into the porous voids to fix the ink. Therefore, even if a transparent support is used, there is a problem that the porous ink absorbing layer deteriorates light transmittance.

In addition, when the surface of the ink absorption layer is non-porous, the light transmittance is improved, but the water-based ink receptivity is poor, so the image recording water-permeable ink remains on the surface of the recording sheet for a long time and dries. There was a problem that the fixing time was long.

That is, there was a problem in that ink flow was likely to occur.

In order to solve these problems, many recording sheets have been proposed in which a transparent ink receiving layer with high aqueous ink receptivity is provided on a transparent support.

For example, JP-A-60-168651 uses polyvinyl alcohol and polyacrylic acid-based water-soluble polymers, JP-A-60-262,685 uses hydroxyethyl cellulose, and JP-A 61-181,679 uses carboxymethyl cellulose. The use of a mixture of polyethylene oxide and JP-A-61-193879 proposes the use of a mixture of water-soluble cellulose and polyvinylpyrrolidone.

(Intelligence B to be Solved by the Invention) The recording sheets described in these patents have the characteristics of excellent light transmittance and high aqueous ink receptivity, that is, excellent ink flow prevention properties. This had the problem of poor image depiction.

In particular, in inkjet recording, line images such as characters are formed by a collection of ink dots, and each ink dot is required to spread appropriately in the ink receiving layer. However, if the highly ink-absorbing polymer described in the above-mentioned patent is used in the ink-receiving layer to prevent ink flow, the ink droplets do not spread in the ink-receiving layer and there are gaps between the dots that make up the line drawing. There was a problem that this resulted in a weak line image with low density.

Accordingly, a first object of the present invention is to provide an ink recording sheet which has excellent receptivity to aqueous ink and which provides clear line images with high density.

The second object is to provide an ink recording sheet that provides high quality ink recording with excellent resolution and color reproducibility.

A third object is to provide an ink recording sheet that has the above characteristics and can be used as a color transbearing range.

(Means for solving the problems) The above aspects of the present invention include a layer containing a block polymerized surfactant of polyoxyethylene and polyoxypropylene and a water-soluble polymer on at least one side of a transparent support. This was achieved by an ink recording sheet characterized by the following.

The present invention will be explained in detail below.

As described above, the ink recording sheet of the present invention is provided with an aqueous ink receiving layer containing a block polymerized surfactant of polyoxyethylene and polyoxypropylene and a water-soluble polymer on at least one side of a transparent support. It is being

The block-polymerized surfactant of polyoxyethylene and polyoxypropylene used in the present invention (hereinafter referred to as POEP surfactant) has - a hydrophobic group of polyoxypropylene in the molecule, and polyoxypropylene as a hydrophilic group at both ends. Refers to a surfactant having oxyethylene, and has the following general formula (1
) or (n).

General formula (1) % formula %) General formula (n) where aSb, c, m, and n each represent a positive integer. These POEP surfactants are manufactured by Wyandotte Chemical Co. and Asahi Denka Kogyo. , Pluronic surfactants (corresponding to general formula (1)) and Tetronic surfactants (corresponding to general formula (n)) are commercially available and can be used. The surfactant belongs to the so-called nonionic surfactants, but its hydrophobic group is located in the center of the molecule, the hydrophilic groups occupy both ends, and the chain length of the hydrophobic group is relatively long. It differs from general nonionic surfactants in this respect.

In general formula (1), b is preferably 10 to 100,
a+c is preferably 2 to 400, the polyoxyethylene content is preferably 10 to 80%, and the average molecular weight is preferably 1,000 to 2o, ooo.

In general formula (II), m is preferably 2-5Q, n
is preferably 1 to 200, the polyoxyethylene content is preferably 10 to 80%, and the average molecular weight is preferably 1,000 to 40,000.

Preferred examples of the POEP surfactant used in the present invention are shown below.

As the water-soluble polymer used in the present invention, any conventionally known water-soluble polymer can be used.

Specific examples of these water-soluble polymers include vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinylpyridinium halide, cationic modified polyvinyl alcohol, and derivatives thereof (JP-A-60-145879, JP-A-60-220750, JP-A-60-220750; No. 61-143177, No. 61-235182, No. 6
No. 1-245183, No. 61-237681, No. 61
-261089) containing acrylic groups such as polyacrylamide, polydimethylacrylamide, polydimethylaminoacrylate, polysodium acrylate, acrylic acid methacrylic acid copolymer salt, polysodium methacrylate, acrylic acid vinyl alcohol copolymer salt, etc. Polymer (JP-A-60-168651
No. 62-9988), starch, oxidized starch, starch acetate, amine starch, carboxyl starch, dialdehyde starch, cationic starch, dextrin, sodium alginate, gum arabic, casein, pullulan, dextran, methyl cellulose, ethyl cellulose, carboxy Natural polymers such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose or derivatives thereof (JP-A-59-174382, JP-A-60-262685)
Gelatin such as lime-treated gelatin, acid-treated gelatin, phthalated gelatin, acetylated gelatin, succinated gelatin, Synthetic polymers such as derivatives thereof, polyethylene glycol, polypropylene glycol, polyvinyl methyl ether, maleic acid-vinyl acetate copolymer, maleic acid-alkyl vinyl ether copolymer, maleic acid-N-vinylpyrrole copolymer, polyethyleneimine, etc.
JP-A-61-32787, JP-A No. 61-237680,
61-277483), and JP-A-56-5
Examples include water-soluble polymers described in No. 8869.

In addition, super absorbent polymers such as starch-polyacrylonitrile hydrolyzate, starch-polyacrylate crosslinked product, carboxymethylcellulose crosslinked product, ketonized product of vinyl acetate-methyl acrylate copolymer, and polysodium polyacrylate crosslinked product Partially crosslinked water-soluble polymers known as (see, for example, "High-Tech Polymer Materials", page 216, published by Agne Co., Ltd., 1986) can also be used in the present invention.

In the present invention, conventional nonionic, anionic, cationic or amphoteric surfactants can be used with POEP surfactants.

For example, saponins (steroids), alkylene oxide derivatives (e.g. polyethylene glycol, polyethylene glycol alkyl ethers or polyethylene glycol alkyl aryl ethers, polyethylene glycol sorbitan esters, polyalkylene glycol alkyl amines or amides, polyethylene oxide adducts of silicones) ), glycidol derivatives (nonionic surfactants such as cf alkenylsuccinic acid polyglycerides, alkylphenol polyglyceride fatty acid esters, alkyl esters of sugars; alkyl carboxylates, alkyl sulfonates, alkylbenzenesulfone alkyl sulfates) , alkyl phosphate esters,
Carboxy groups, sulfo groups, phosphor groups, such as N-acyl-N-alkyl taurines, sulfosuccinic acid esters, sulfo-oxyethylene alkylphenyl ethers, bo-1-oxyethylene alkyl phosphates, etc. Anionic surfactants containing acidic groups such as sulfate ester groups and phosphate ester groups; Ampholytic surfactants such as amino acids, aminoafrekylsulfonic acids, aminoalkyl sulfates and phosphates, alkyl betaines, and amine oxides. using cationic surfactants such as alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium and imidazolium, and phosphonium or sulfonium salts containing aliphatic or heterocyclic rings; be able to.

Further, in the present invention, fluorine-based surfactants described in JP-A-60-244945, JP-A-61-20944, JP-A-62-135826, etc. can be used.

Among these surfactants, amphoteric surfactants and fluorosurfactants give particularly favorable results when used in combination with the POEP surfactant of the present invention.

In the present invention, the dry film thickness of the aqueous ink receiving layer is 1.0
It is preferably from μm to 20 μm, more preferably from 2 μm to 10 μm.

The amount of POEP surfactant added is 100 g of the binder (1!II water-soluble polymer) that constitutes the aqueous ink receiving layer.
The amount is preferably 0.05 to 5 g, more preferably 0.05 to 5 g.
It is 2 to 2.5 g.

In the present invention, the aqueous ink receiving layer may have a single layer structure or a multilayer structure. An example of a multilayer structure is Japanese Patent Application Laid-Open No. 57-8
No. 9954, No. 60-224578, No. 61-123
Examples include those described in No. 88.

For example, the ink-permeable layer described in JP-A-61-12388 may be further provided on the aqueous ink-receiving layer of the present invention.

Further, although the aqueous ink receiving layer is provided on at least one side of the transparent support, it is more preferable to provide the aqueous ink receiving layer on both sides of the transparent support because this prevents the resulting recording sheet from curling.

As the transparent support used in the present invention, any conventionally known support can be used, such as polyester resin, diacetate resin, triacetate 411L acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyimide resin, cellophane resin, etc. , films or plates such as celluloid, and glass plates.

Such a transparent support has a thickness of about 10 to 200μ
It is preferable that the diameter is about m.

A method for forming an aqueous ink-receiving layer on the above-mentioned transparent support is to prepare a coating solution by dissolving or dispersing a mixture of a water-soluble polymer and a POEP surfactant in water or an appropriate organic solvent; The liquid may be coated on a transparent support by a known method such as a roll coating method, a road per coating method, an air knife coating method, or a spray coating method, and then dried. , a single aqueous ink receiving layer sheet is formed by a known method such as the T-dye method, and used so that the aqueous ink receiving layer also functions as a support, or the sheet is used as a transparent support as described above. The aqueous ink-receiving layer may be formed on the transparent support by a method of laminating the ink on the transparent support, a method of net-melt coating the above-mentioned mixture, or the like.

In the present invention, in order to improve the adhesion between the transparent support and the aqueous ink receiving layer, the surface of the transparent support may be subjected to anchor coating treatment or corona discharge treatment.

In the present invention, for example, silica, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolite, zinc oxide,
Fillers such as Litopone, Satin White, etc. can also be dispersed in the aqueous ink-receiving layer.

Furthermore, the aqueous ink receiving layer contains a dispersant, a fluorescent dye, a pH
Various known additives such as regulators, antifoaming agents, lubricants, antifading agents, preservatives, and polymer crosslinking agents may also be added.

Since the ink recording sheet of the present invention has excellent translucency and ink drawing properties, its use is not limited to OHP only, but also for projection observation of recorded images using optical equipment other than OHP, such as slides, onto a screen, etc. It can also be applied to applications other than conventional surface image observation, such as color separation plates used in producing positive plates for color printing, and CMF used in color displays such as liquid crystals.

Furthermore, even for OHP use, recording means other than ink shared printers, such as blocks using an aqueous ink pen, handwriting, etc., are also included in the application of the present invention.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited by these Examples.

A coating solution having the following structure was coated by a bar coating method on a polyethylene terephthalate film support having a thickness of 100 μm and provided with an anchor coating to obtain a recording sheet.

Recording sheet resistance 1> (present invention) Acid-treated gelatin (isoelectric point 9.0) 2.80 g/i carboxymethyl cellulose 3.20 Compound of the present invention 1-7 0.05 Matting agent
0.02〃(Silica particle size 2-6μm
) Crosslinking agent *l O, lO <Recording sheet magnetic 2> (invention) Acid-treated gelatin (isoelectric point 9.0) 2. 80g/r
d Carboxymethylcellulose 3゜20 Compound of the present invention 1-19 0.07g/m.

Surfactant-1120,03~ Surfactant-2 $3 0.06 Matting agent
0.02〃(Silica particle size 2
~ 6 μm) Crossing agent * 1 0.10〃 <Recording sheet bottleneck 3> (present invention) Futalized gelatin 3.50 GIRD (98 % Futalization) polyethylene oxide 2.50 〃 (molecular weight 300,000) 12 0.07 Matting agent *4 0.02” Crosslinking agent $1
0.20 Chelating agent *5
0.10"<Recording sheet 1lkL4> (Invention) Water-soluble polymer *6 2.50g/Icarboquine methylcellulose 2.00g/n (Hydroquine ethylcellulose 1.50 Invention compound 11-
5 0.10” cloak agent 0
．． 02-(Silica particle size 2 to 6 μm) Crosslinking agent *1 0.20"<Recording sheet IIkL5> (Comparative example) A recording sheet with the same configuration as the recording sheet list I except that it does not contain the compound of the present invention was prepared. 5 was prepared.

<Recording Sheet 11kL6> (Comparative Example) A recording sheet HkL6 was prepared using a nonionic surfactant *7 instead of the compound of the present invention in recording sheet No. 4.

CFs (crt)t sot N-CHz CO
x KsHt *3 (Surfactant-2) Hs *4 (Matting agent) Benzoguanamine resin (Nippon Shokubai Kagaku side type, average particle size 10 μm) 5 (Chelate 7f11) Sodium ethylenediaminetetraacetate *6 (Water-soluble polymer) Acrylic acid -Vinyl alcohol copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name Sumikagel L-5H) *7 (Nonionic surfactant) Recording sheets Nos. 1 to 6 obtained as above were coated with Sharp ■ No. 10- An image was recorded using a 725 inkjet printer, and the drawability of the character portion (printed line portion) and image portion (uniform image portion) was evaluated.

All of the m 1-11h 4 recording sheets of the present invention had high density in the image area, sharp line edges, and little unevenness in the uniform image area. On the other hand, the positive 5 recording sheet was good with little unevenness in the uniform image area, but the density in the image area was low and was unsuitable as an OHP sheet. The patient record sheet 6 had a high density of text, but the text was difficult to read because the lines were cut off in the middle or merged with adjacent lines. Furthermore, there were many unevenness in the uniform image area.

Patent applicant: Fuji Photo Film Co., Ltd.
Mon-12th

Claims (1)

[Claims] (1) An ink recording sheet characterized in that a layer containing a block-polymerized surfactant of polyoxyethylene and polyoxypropylene and a water-soluble polymer is provided on at least one side of a transparent support.