JPS6235870A - Recording material - Google Patents

Abstract

PURPOSE:To provide a recording material having excellent ink receptivity, water resistance and the clearness or recorded images, by providing an ink- receiving layer and a flexible protective layer on a base, which ink-receiving layer comprises a polymer complex of a basic polymer and an acidic polymer. CONSTITUTION:The ink jet recording material comprises the base and the ink-receiving layer and the flexible protective layer which are provided on the base, the ink-receiving layer comprising a polymer complex of a basic polymer and an acidic polymer. The recording material generally comprises the base, the ink-receiving layer comprising a specified material provided on the surface of the base, and the flexible protective layer provided thereon. An embodiment in which all of the base, ink-receiving layer and protective layer are light-transmitting so that the recording material as a whole is light- transmitting, an embodiment in which at least one of the base, ink-receiving layer and protective layer is opaque so that the recording material as a whole is opaque, or the like is particularly preferred.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a recording material suitably used in an inkjet recording method, and in particular to a recording material that has excellent ink receptivity, sharpness of recorded images, and water resistance. Regarding.

(Prior Art) Inkjet recording methods include various ink (recording liquid) ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, and a method that heats the ink to foam it. This method utilizes the pressure to generate and fly ink droplets, and some or all of them adhere to a recording material such as paper to perform recording, but it generates little noise and It is attracting attention as a recording method that can perform high-speed printing and multicolor printing.

Ink for inkjet recording is mainly composed of water for safety and recording characteristics, and polyhydric alcohols are added to prevent nozzle clogging and improve ejection stability. In many cases.

The recording material used in this inkjet recording method has conventionally been a recording material consisting of a base material called ordinary paper or inkjet recording paper on which a porous ink receiving layer is provided.

However, as the performance of inkjet recording apparatuses increases and becomes more widespread, such as faster recording speeds and multicolor recording, more advanced and wide-ranging properties are being required of recording materials.

That is, it can be used as a recording material for inkjet recording to obtain high-resolution, high-quality recorded images.

(1) The ink must be received by the recording material as quickly as possible; (2) Even if ink dots overlap, ink deposited later will not flow into the dot deposited earlier; (3) ) The diameter of the ink dot should not become larger than necessary due to the ink droplet spreading on the recording material, (4) The shape of the ink dot should be close to a perfect circle, and the circumference should be smooth; (5) ) The 00 (optical density) of the ink dots is high.

The area around the dot will not be blurred, It is necessary to satisfy basic requirements such as:

Furthermore, in order to obtain a high-resolution recorded image quality comparable to that of a color photograph using a multicolor inkjet recording method, in addition to the above-mentioned required performance.

(6) The coloring components of the ink should have excellent color development properties; (7) The ink fixation properties are particularly excellent because the same number of droplets as the number of ink colors may overlap and adhere to the same location. (8) A glossy surface; (9) High whiteness.

In addition, images recorded by the inkjet recording method have traditionally been used exclusively for surface image observation, but as the performance of inkjet recording devices has improved and become more widespread, recording materials suitable for purposes other than surface image observation have become available. is becoming required.

Applications of recording materials other than surface image observation include those used to project recorded images onto a screen etc. using an optical device such as a slide or OHP (overhead projector) and observe those images, and color recording materials. Examples include color separation plates used to create positive plates for printing, and CMF (color mosaic filters) used in color displays such as liquid crystals.

When a recording material is used for surface image observation, the diffused light of the recorded image is mainly observed, whereas for recording materials used in these applications, the problem is mainly the transmitted light of the recorded image. Become. Therefore, it is required to have excellent light transmittance, especially linear light transmittance, in addition to the above-mentioned performance requirements of the general recording material for inkjet recording.

(The problem that the invention is trying to solve) However,
The reality is that there is still no known recording material that satisfies all of these required performances.

In addition, many conventional recording materials for surface image observation use a method in which a porous ink-receiving layer is provided on the surface, and the ink is received in the porous voids to fix the recording material. The surface of the recording material was not glossy due to the nature of the recording material.

On the other hand, when the surface of the ink-receiving layer is non-porous, non-volatile components such as polyhydric alcohols in the ink remain on the surface of the recording material for a long time after recording, and the drying and fixing time of the ink is long. There are disadvantages in that clothing may get dirty or the recorded image may be damaged if it comes into contact with the recorded image.

In addition, in the case of recording materials that use water-soluble polymers to form the ink-receiving layer in order to improve affinity with ink and ink receptivity, the surface of this ink-receiving layer becomes sticky under high humidity conditions. Therefore, when it is installed in a printer, it adheres to the printer's feed roller, etc., making it impossible to convey the recording material, and also causing blocking of the recording materials when stacked.

Therefore, an object of the present invention is to provide a recording material for inkjet recording that is particularly excellent in ink receptivity, water resistance, and clarity of recorded images.

Another object of the present invention is to provide a recording material for full-color inkjet recording that has excellent ink receptivity, sharpness of recorded images, and surface gloss, and does not cause surface stickiness, blocking, etc. even under high humidity conditions. It is in.

Another object of the present invention is to use an optical device such as a slide or OHP to project a recorded image onto a screen for observation, a color separation plate for creating a positive plate for color printing, or a color separation plate for liquid crystal display. C used for display
An object of the present invention is to provide a recording material for inkjet recording that can be used for observation of transmitted light such as MF.

The above and other objects of the invention are achieved by the following invention.

(Disclosure of the Invention) That is, the present invention has a base material, an ink-receiving layer provided on the base material, and a flexible protective layer, and the ink-receiving layer comprises:
This is an inkjet recording material characterized by being made of a polymer complex of a basic polymer and an acidic polymer.

To explain the present invention in detail, the recording material of the present invention has an ink-receiving layer made of a specific material formed on a base material.
Furthermore, the main feature is that a flexible protective layer is provided, and the object of the present invention is mainly achieved thereby.

The recording material of the present invention generally consists of a base material as a support, an ink-receiving layer made of a specific material provided on the surface of the base material, and a flexible protective layer provided on the ink-receiving layer.
For example, particularly preferred embodiments include (1) an embodiment in which the base material, the ink-receiving layer, and the protective layer are all translucent, and the recording material as a whole is translucent; (2) the base material, the ink-receiving layer, and the protective layer are translucent; at least one of the protective layers
Examples include an embodiment in which the layer is opaque and the recording material as a whole is opaque.

In any of the above cases, the ink receiving layer may also have the function of a support.

The present invention will be explained in more detail using the above two preferred embodiments as representative examples.As the base material that can be used as a support in the present invention, any of the conventionally known base materials such as transparent and opaque base materials can be used. Examples of suitable transparent substrates that can be used include 1, polyester resins, 2 diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, polyimide resins, cellophane, celluloid, etc. Examples include films or plates and glass plates.

Preferred examples of the opaque substrate include, for example, general paper, cloth, wood, metal plates, synthetic paper, and the like, as well as the above-mentioned transparent substrates treated to make them opaque by known means. Such a substrate has a thickness of about lO~20
Preferably, it is in the range of 0 ILm.

The ink-receiving layer in the present invention is characterized by being formed from a polymer complex that can quickly and stably hold ink several times its own weight and form a layer with excellent water resistance and moisture resistance.

The polymer complex preferably used in the present invention is composed of a basic polymer and an acidic polymer, and is already known per se, for example, in Japanese Patent Publications No. 51-37017 and Japanese Patent Publication No. 55-42744.

In the present invention, preferred basic polymers include, for example, the following.

N-vinylpyrrolidone, N-vinyl-3-methylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-3,3,5-)limethylpyrrolidone, N-vinyl-3
-Benzylpyrrolidone, N-vinylpiperidone, N-vinyl-4-methylpiperidone, N-vinyl-caprolactam, N-vinylcapryllactam, N-vinyl-3-
Morpholine, N-vinylthiopyrrolidone, N-vinyl-
Homopolymers such as 2-pyridone or random copolymers, block copolymers, graft copolymers, etc. with other common monomers; N-vinyl-2-oxazolidone, N-vinyl-5-methyl-2 -Oxazolidone, N-vinyl-5-ethyl-
2-oxazolidone, N-vinyl-4-methyl-2-oxazolidone, N-vinyl-2-thioxazolidone,
Homopolymers such as N-vinyl-2-mercaptobenzothiazole or random copolymers with other common monomers, block copolymers, graft copolymers, etc.; N-vinylimidazole, N-vinyl-2- Homopolymers such as methylimidazole and N-vinyl-4-methylimidazole, or random copolymers and block copolymers with other common monomers.

Graft copolymers, etc.: Examples include homopolymers such as 2- or 4-vinylpyridine, or random copolymers with other common heptamers, block copolymers, graft copolymers, etc. Other copolymerizable septamers that may be used include methacrylate, acrylate, acrylamide, acrylonitrile, vinyl ether, vinyl acetate, vinylimidazole,
Ethylene, styrene and other common monomers, such as those particularly useful in the present invention, include N-vinylpyrrolidone, N-vinylpiperidone, N-vinylprolactam, N-vinylmorpholine, N-vinyl-2-oxacylidone. , a homopolymer, a copolymer of N-vinyl-5-methyl-2-oxazolidone, and the like. In the case of a copolymer, it is preferable that the above-mentioned nitrogen-containing monomer is included in an amount of 50 mol % or more.

In addition, an acidic polymer that can form a polymer complex with the above basic polymer (in the present invention, the term "acidic polymer" refers to a sulfonic acid group, a carboxylic acid group, a sulfuric acid ester group, a phosphoric acid ester group, or a phenolic acid group in its molecule). In addition to those having a hydroxyl group, the examples also include those having an alcoholic hydroxyl group.) include, for example, the following.

1. Polymer having a carboxylic acid group Terminal carboxyl obtained by reacting a polycarboxylic acid such as citric acid, tartaric acid, or phthalic acid with a polyhydric alcohol such as ethylene glycol, 1.4-butanediol, or diethylene glycol in excess of acid. Base polyester: Acidic cellulose derivative modified with various polyhydric carboxylic acids (
Homopolymers such as vinyl ether ester monomers of polyvalent carboxylic acids, random copolymers, block copolymers, graft copolymers, etc. with other common monomers (see Japanese Patent Publication No. 35-5093); 35-8495
(Refer to the publication No. 2002-12-13); A heptamer homopolymer such as acrylic acid or methacrylic acid or a random copolymer with other common monomers,
Block copolymers, graft copolymers, etc.; Homopolymers of α,β-unsaturated vinyl humers such as maleic anhydride and itaconic acid, or random copolymers and block copolymers with other common heptamers Coalescence, graft copolymers, etc. (citrus, Inoue, valley line, synthetic polymer (m) P, 25
0-257 and P, 374-380, Breakfast Bookstore (19
71); 2. Polymers with sulfonic acid groups 0-Ethylcellulose hydrogen acetate hydrogen sulfate phthalate, cellulose hydrogen acetate hydrogen sulfate phthalate, ethylcellulose hydrogen-〇-sulfobenzoate ester, 0-P-sulfonebenzylcellulose acetic acid ester, 0-ethyl-
〇-Cellulose derivatives such as P-sulfoethyl cellulose acetate (see Japanese Patent Publication No. 35-5093)
; Sulfonic acid compounds of polyvinyl alcohol or vinyl alcohol copolymers (e.g., 0-sulfobenzoic acid,
3. Polymers with phenolic acidic groups in the main chain of polymers with phenolic hydroxyl groups.

For example, phenol, m-cresol, 3.5-xylenol, P-alkylphenol, resorcinol, α- or β-naphthol, etc., which have a hydroxyl group in the aromatic ring, or their derivatives are used as monomers, and aldehydes such as formalin are used as monomers. Examples include so-called phenol resins obtained by addition/condensation reactions or initial condensates thereof. These polymers may be homopolymers, copolymers, or random, block, or graft copolymers.

These phenolic acidic polymers range from those with relatively low molecular weights that are soluble in water and organic solvents to those with high molecular weights that are insoluble and infusible. Particularly useful are those that are soluble, such as precondensates of phenolic resins.

Although these phenolic acidic polymers are generally hydrophilic, they can only form a hard and brittle film and cannot be used at all as an ink-receiving layer of a recording material. By forming a complex with a polymer, an ink-receiving layer having various excellent properties can be formed.

In addition, examples of polymers having phenolic hydroxyl groups in the side chains include polymers of vinyl monomers having phenolic hydroxyl groups such as vinylphenol and vinylnaphthol, or copolymers with other general monomers; A modified polymer obtained by modifying a general polymer having a functional group such as an amino group with a compound having a phenolic hydroxyl group can also be used in the same manner as the above-mentioned phenolic resin.

Although any of the above acidic polymers can be used, particularly preferred in the present invention are polymers having phenolic hydroxyl groups.

When a basic polymer and an acidic polymer such as those mentioned above are mixed in a solution, both polymers interact in some way, forming a polymer complex that is different from either polymer, and comparing both polymers. If mixed in a relatively good solvent, a polymer complex will precipitate, and if mixed in a relatively good solvent, a significant increase in viscosity will occur, resulting in properties different from a simple mixture of both polymers used. .

Therefore, the polymer complex used in the present invention means a polymer complex made of the above-mentioned polymers (details of basic polymers, acidic polymers, and polymer complexes made of these polymers can be found in Japanese Patent Publication No. 51-37017). (Please refer to Japanese Patent Publication No. 55-42744).

The inventor further conducted various studies on the uses of these polymer complexes, and found that although the coatings made of these polymer complexes are extremely hydrophilic, they are water and moisture resistant, making them suitable for inkjet recording materials. When used to form an ink-receiving layer, it was discovered that it exhibited ink-receptivity equivalent to that of conventional water-soluble polymers, provided clear images, and formed an ink-receptive layer with sufficient water resistance. .

As mentioned above, polymer complexes generally contain water,
Since it does not dissolve in relatively poor solvents such as alcohols, esters, hydrocarbons, etc., the polymer complex used in the present invention can be prepared by dissolving both polymers in these poor solvents and mixing the re-solutions. Can be isolated. Alternatively, a solution of the polymer complex can be obtained by mixing in a relatively good solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, or the like.

Preferred basic polymers and acidic polymers for forming the above polymer complexes each have a molecular weight of 500 or more, preferably t,ooo or more, and by using both polymers with these molecular weights, It is possible to form an ink-receiving layer that has high strength, excellent clarity of ink-receptive single images, and excellent water resistance.

Furthermore, the ratio of both polymers used is in a range such that the weight ratio of basic polymer/acidic polymer is 20/l to 1/l O, and preferably, the basicity and acidity of each polymer are approximately equal. It is a percentage. If the weight ratio deviates from the above range, the bond between both polymers will be insufficient, and the object of the present invention will not be fully achieved. That is, if the basic polymer is too large, the water resistance will be reduced, and if the acidic polymer is too large, the ink receptivity will be reduced.

The ink-receiving layer of the recording material of the present invention is formed using one or more polymer complexes, but in the present invention, general water-soluble to hydrophilic You may use a mixture of the above-mentioned polymer and the above-mentioned polymer complex.

Furthermore, in order to reinforce the strength of the ink-receiving layer and/or improve the adhesion with the base material, SBR latex, NBR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride may be added as necessary. , polyvinyl acetate,
Phenolic resin.

Resins such as alkyd resins may be used in combination.

In addition, in order to improve the ink absorbency of the ink receiving layer, various fillers such as silica, clay, etc. are added to the ink receiving layer.
Fillers such as talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolites, alumina, zinc oxide, lithopone, satin white, and the like can also be dispersed in the ink-receiving layer.

As a method for forming such an ink-receiving layer, a coating solution is prepared by dissolving or dispersing the above-mentioned polymer complex alone or a mixture with other suitable polymers in a suitable solvent, and the coating solution is prepared by: For example, it can be formed by coating on a translucent substrate by a known method such as a roll coating method, a rod bar coating method, a spray coating method, an air knife coating method, etc., and then rapidly drying it. A particularly preferred method is to dissolve the polymer complex with a good solvent capable of dissolving the polymer complex to form a coating solution, then apply and dry this as described above, or to use either a solution of a basic polymer or an acidic polymer. There is a method in which a polymer complex is formed on the substrate by coating and then another solution is applied, and another method is a method in which the above-mentioned polymer complex alone or a mixture with other polymers is hot-melt coated, or once from the above-mentioned materials. A separate ink-receiving layer film is formed,
Other methods such as laminating the film to the above substrate may also be used.

In the above invention, the thickness of the ink receiving layer formed on the substrate is usually about 1 to 2004 m, preferably about 3 to 1100 m, more preferably about 5 to 30 m.

The present inventor believes that the above-mentioned polymer complex is useful for forming an ink-receiving layer of a recording material, and that an ink-receiving layer formed using such a polymer complex has rapid ink absorption during recording, It was discovered that a recording material with excellent subsequent ink fixability, water resistance, and various other properties can be obtained (see Japanese Patent Application No. 60-26333 and other specifications).
.

However, since the ink receiving layer obtained in this way absorbs ink quickly during recording, the portion of the receiving layer that has absorbed the ink locally expands and bulges.
In particular, when receiving high-density ink dots, that part of the ink-receiving layer expands and swells significantly, which weakens the film strength of the ink-receiving layer. It is said that these may cause blocking, and when the surface is touched by fingers or objects, the printed area may peel or peel off from the base film, damaging the ink-receiving layer of the recording material. A new problem arose.

As a result of further research, the present inventors aimed to solve the above problems while retaining the various advantages of the prior invention, such as excellent ink absorption, ink fixation, and water resistance. By forming a flexible protective layer on the surface of the ink-receiving layer made of the polymer described above, which can sufficiently follow the expansion and swelling of the ink-receiving layer due to ink absorption during recording, various excellent performances can be maintained. The above problems have been solved, and it has been discovered that the film of the ink receiving part is strong and does not easily peel or break, and does not cause blocking, especially in areas where ink dots are concentrated.
This led to the present invention.

A preferred example of a material useful for forming such a flexible protective layer is a polyurethane resin, and such a polyurethane resin includes a polyisocyanate compound and a compound 1 having two or more active hydrogens, such as a polyol. , polyamines, and polycarboxylic acids, any of which are conventionally known can be used. A particularly preferred material is a terminal NGO obtained by reacting a polyisocyanate compound and a polyol compound with an excess of NGO.
A urethane prepolymer is used, and the prepolymer is polymerized and crosslinked on the ink retaining layer with a suitable chain extender such as water, hydrazine, low molecular weight polyol, low molecular weight polyamine, low molecular weight alcohol amine, etc. .

Polyisocyanates useful in forming polyurethanes or urethane prepolymers having two inocyanate groups include 1,2-diisocyanateethane, 1,2-diisocyanatepropane, tetramethylene-1,4-diisocyanate, and pentamethylene. -1,
5-diisocyanate, hexamethylene-1,6-diisocyanate, nonamethylene-1,9-diisocyanate, decamethylene-1,10-diisocyanate, ω,
ω'-dipropyl ether diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexahydrodiphenyl di-4,4'-diisocyanate, hexahydrodiphenyl ether-4,4'-diisocyanate, phenylene- 1,4-diisocyanate, tolylene-2,
6-diisocyanate, tolylene-2,4-diisocyanate, l-methoxybenzene-2°4-diisocyanate, 1-chlorophenylene diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate.

Paraxylylene diisocyanate, diphenylmethane
4,4'-Diincyanate, diphenyl sulfide
4,4'-diisocyanate, diphenylsulfone-4
, 4'-diisocyanate, diphenyl ether-4,
4'-diisocyanate, diphenyl ether 3,4'
2.4"
-Biphenyl diisocyanate, 4,4'-biphenyl diisocyanate, 3゜3'-dimethoxy-4,4'-
Biphenyl diisocyanate, anthraquinone-2,6
-Diisocyanate, triphenylmethane-4,4'-
Examples include diisocyanate and azobenzene-4,4'-diisocyanate.

Examples of those containing three isocyanate groups include triphenylmethane triisocyanate, compounds represented by the following structural formulas (I) to (mV), and derivatives of these compounds. Alternatively, one or more of these compounds can be selected and used as desired to form a urethane prepolymer.

(1) O t OCN (CH,), NHCNH (CH,), NGO
(III) (CH2), NCO■ (■) 0 In addition, as a compound having two or more active hydrogens, a preferable compound is a polyol that is insoluble in water but has wood-philicity, and is suitable as such a polyol. Examples include polyester polyols, polyether polyols, and polyester polyether polyols, and the most preferred is polyether polyols.

A polyester polyol is a compound produced from a polybasic acid and a polyhydroxy compound, and a terminal hydroxy polyester is preferred. As polybasic acids, saturated fatty acids such as oxalic acid, succinic acid, adipic acid, and pimelic acid, unsaturated fatty acids such as maleic acid and fumaric acid, aromatic acids such as phthalic acid and inphthalic acid, or their anhydrides may be used alone or in combination. As the polyhydroxy compound, one or two types of diols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol, triols such as trimethylolpropane, trimethylolethane, hexanetriol, and glycerin, and hexaols such as sorbitol are used. The above can be used in combination.

Such polyester polyols generally have low hydrophilicity, so if a hydrophilic polyurethane resin is required, use one that has an unsaturated group as part of the raw material polybasic acid, and use it as a polyester polyol. It is preferable to make it wood-philic by a known method such as graft polymerization of a sulfonic acid group, a cationic group, or a water-soluble hetamine using the unsaturated groups present after the polyurethane or after it has been made into polyurethane.

The polyether polyol used in the present invention is a compound that contains two or more hydroxyl groups in one molecule and has an ether bond, and is a compound that contains fullylene oxide such as ethylene oxide (EO) or propylene oxide (PO) alone. Polymers or copolymers, and triols such as glycerin, trimethylolpropane, hexanetriol,
Polyhydric alcohols such as hexaol such as sorbitol or ethylene diamine, benzene sulfur atom, 2-7
Examples include polyols formed by optionally adding alkylene oxides such as EO or PO to amines such as minoethanolamine, N-methyljetanolamine, diethylenetriamine, and amines having an aromatic group, or derivatives thereof. It is possible to use one type or a mixture of two or more types.

The polyester polyether polyol is obtained by condensing the above polybasic acid and polyether polyol so as to form terminal hydroxyl groups.

Other polyols include, for example, castor oil, tall oil or their derivatives, acrylic polyols, urethane polyols, and the aforementioned low molecular weight polyhydric alcohols can also be used as polyol components. Furthermore, it goes without saying that the various polyols mentioned above can be used alone or as a mixture.

Conventionally known methods are used to produce the polyurethane as described above. As an example, a compound having active hydrogen and a polyisocyanate compound having the same number of moles or more as the active hydrogen group are heated at 30 to 120°C for 30 minutes to 1 hour.
It can be synthesized by reacting for 68 hours using dibutyltin dilaurate or triethylene diamine as a catalyst if necessary.

In the production of polyurethane, the aforementioned low molecular weight polyols, low molecular weight diamines, low molecular weight alcohol amines or i±water, hydrazine, etc. are used as chain extenders.

The polyurethane or inocyanate-terminated urethane prepolymer comprising the above-mentioned components can be prepared by any known method, but the inocyanate-terminated urethane prepolymer may be commercially available,
For example, a prepolymer which is an adduct of tolylene diisocyanate and various polyester polyols or polyether polyols and which is a terminal isocyanate can also be used.

Furthermore, the urethane polymer may be a blocked urethane prepolymer stabilized by blocking its terminal NCO.

Polyurethanes or urethane prepolymers made of such components can be used in combination with other polymers, such as homopolymers or copolymers made of vinyl acetate, acrylic esters, ethylene, vinyl chloride, other vinyl monomers, and various vinyl monomers such as those mentioned above. Polymers consisting of wood-philic vinyl monomers, further polymers such as vinylon, cellulose derivatives, polyesters, polyamides, etc.
It can also be used in combination with the above-mentioned wood-philic polymer for forming an ink-retaining layer.

The polyurethane or urethane prepolymer described above may be used in any state, including as a solution in an organic solvent, as an emulsion in an aqueous medium, or as a fine dispersion in an organic solvent or an aqueous medium. When used as a solution, it is preferable to use a relatively dilute solution or a concentration such that the layer formed falls within the above range.

In addition to the polyurethane described above, a cellulose derivative can also be used to form a flexible protective layer useful in the present invention. Such cellulose derivatives are obtained by adding alkyl groups such as methyl groups and ethyl groups and/or hydroxyalkyl groups such as hydroxyethyl groups, hydroxypropyl groups, and ethylhydroxyethyl groups to cellulose (cellulose). Examples include cellulose ethers, cellulose esters obtained by esterifying the hydroxyl group of cellulose with acetic acid, nitric acid, sulfuric acid, propionic acid, acetic acid, higher fatty acids, etc., nitrocellulose, carboxymethylcellulose, carboxymethylethylcellulose, and the like.

Furthermore, in order to improve its properties against water, modified water-soluble celluloses such as those treated with glyoxal or cationized with a cationizing agent such as 2,3-epoxypropyltrialkylammonium chloride are used. Derivatives can be used as well.

The degree of polymerization of the water-soluble cellulose derivative is determined by the degree of polymerization of cellulose as a raw material, and is not particularly limited.
It is sufficient if it is about 00 or more.

The cellulose derivatives described above may be used in any state, including as a solution in water or an organic solvent, as an emulsion in an aqueous medium, or as a fine dispersion in an organic solvent or an aqueous medium.

The method for forming a flexible protective layer using the above-mentioned materials can be the same as that for forming the ink receiving layer described above, and the thickness of the protective layer to be formed is 0.601 to 10 g.
If the thickness of the protective layer exceeds 10 ILm, the ink receiving speed will not be sufficient when recording with a large amount of ink, which is undesirable. , OI ILm is not preferable because the desired effect of the present invention by the protective layer will not be sufficient.

In the present invention, by forming the above-mentioned flexible protective layer on the above-mentioned ink-receiving layer, the above-mentioned problems can be solved without impairing the various advantages of the ink-receiving layer formed solely from the above-mentioned polymer complex. point, i.e.
The problems of decreased film strength and blocking caused by expansion and swelling of the ink-receiving layer due to rapid absorption of ink during recording are fully resolved, and the ink fixation properties of the recording material are further improved. .

These remarkable effects are due to the fact that the protective layer made of polyurethane material or cellulose derivative as described above has sufficient water resistance, has high ink permeability, and is a flexible and elastic coating. This is thought to be due to the fact that even if the ink-receiving layer is rapidly absorbed by the ink-receiving layer and the ink-receiving layer expands and bulges locally, the protective layer can sufficiently follow these bulges and bulges.

Furthermore, the surface of the protective layer made of polyurethane or cellulose derivatives is irregular on a microscopic scale.

As a result, the adhered ink quickly spreads on the surface,
As a result, the contact area between them is expanded, and rapid expansion and swelling of the ink-receiving layer is suppressed.

It is considered that the problem of decreased strength of the ink-receiving layer has also been solved.

The recording material of the embodiment (1) formed as described above is a light-transmitting recording material having sufficient light-transmitting properties.

In the present invention, sufficient light transmittance means that the recording material preferably exhibits a linear transmittance of at least 2%, preferably 10% or more.

If the in-line transmittance is 2% or more, it is possible to project the recorded image onto a screen and observe it using an OHP, and furthermore, in order to clearly observe the details of the recorded image,
It is desirable that the in-line transmittance is 105 or more.

The linear transmittance T (%) here refers to the incident perpendicular to the sample, transmitted through the sample, and at least 8
The spectral transmittance of the straight light that passes through the light-receiving side slit on the extension of the incident optical path that is further away than C and is received by the detector is 1. Then, from the measured spectral transmittance, the Y value of the tristimulus value of the color is determined, and the value is determined by the following formula.

T=Y/Y, An integrating sphere is placed behind the sample to determine transmittance including diffused light.) and opacity (
The white and black backings are placed on the back of the sample and the ratio is calculated. ), which evaluates translucency using diffused light.

Since the behavior of straight-line light is a problem with devices that use optical technology, it is important to evaluate the straight-line transmittance of the recording material when evaluating the translucency of the recording material to be used in these devices. Asking is especially important.

For example, when observing a projected image on an OHP, in order to obtain a clear and easy-to-see image with high contrast between recorded and non-recorded areas, the non-recorded areas in the projected image must be bright;
That is, the in-line transmittance of the recording material is required to be at a certain level or higher. In an OHP test chart test, in order to obtain an image suitable for the above purpose, the in-line transmittance of the recording material is 2% or more, and in order to obtain a clearer image, it is preferably A 105 or more. That is required. Therefore, recording materials suitable for this purpose are:
It is necessary that the straight line transmittance is 2% or more.

Furthermore, in the embodiment (2) above in which the recording material of the present invention is opaque, an opaque material may be used for at least one layer among the base material, ink receiving layer, and protective layer.

The method of forming each layer used in this embodiment is the same as in the transparency embodiment described above.

In this opaque embodiment, when forming the ink-receiving layer and the protective layer, a large amount of the filler is used to the extent that film-forming properties are not impaired, and further excellent ink-receptivity and fixing properties can be improved. .

Furthermore, in the present invention, fine organic or inorganic powder is applied to the recording surface of the recording materials of various embodiments as described above at a rate of about 0.01 to about 1.0 g/rrf. By doing so, it is possible to further improve the transportability in the printer, the blocking resistance during stacking, the fingerprint resistance, etc. of the obtained recording material.

The present invention has been explained above by illustrating typical aspects of the recording material of the present invention, but of course the recording material of the present invention is not limited to these aspects. Also, the ink-receiving layer and the protective layer contain a dispersant,
Various known additives such as fluorescent dyes, pH adjusters, antifoaming agents, lubricants, preservatives, and surfactants can be included.

Note that the recording material of the present invention does not necessarily have to be colorless, and may be a single colored recording material.

The recording material of the present invention as described above has various types of ink receptivity, such as excellent ink receptivity similar to those in which the ink receptive layer is formed with a conventional water-soluble polymer and the ink receptive layer formed with a polymer complex in the previously filed invention. It exhibits high performance and provides recorded images with excellent clarity, and its surface does not become sticky or sticky even under high humidity conditions, and the strength of the ink-receiving layer does not decrease even if ink dots are concentrated during recording. It does not cause

Therefore, when recording full-color images as well as monochrome images, even if ink of different colors adheres repeatedly to the same location within a short period of time, there will be no ink flow or seepage phenomenon, and the strength of the ink-receiving layer will be reduced. Clear recorded images with high resolution can be obtained without any deterioration.

Therefore, the recording material of the present invention can be used not only for conventional surface image observation, but also for observation by projecting a recorded image onto a screen using an optical device such as a slide or OHP, and for creating a positive plate for color printing. It can be applied to applications such as color separation plates in production, or CMF used in color displays such as liquid crystals.

Hereinafter, the present invention will be explained in more detail according to Examples. In addition, parts and percentages in the text are based on weight unless otherwise specified.

Example 1 Polyvinylpyrrolidone (PVP-90, manufactured by GAF) 1
88 parts of 0% dimethylformamide (hereinafter referred to as DMF) solution and novolac type fer/-resin (Regitop PS)
12 parts of a 10% DMF solution (K-2320, manufactured by Gunei Chemical Co., Ltd.) was mixed. The mixed solution gelled and a polymer complex was formed, and the mixed solution was heated at 90°C while stirring.
When heated, it becomes a solution, which is used as the coating liquid (A).

A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 100 mm was used as the translucent base material.

Coating liquid (A) having the above composition was applied onto this film using a bar coater method so that the film thickness after drying was 6 mm, and dried at 100°C for 10 minutes. After forming the ink-receiving layer, the following coating solution (B) was applied onto the ink-receiving layer so that the dry film thickness was o, iILm, and then dried at 80°C for 5 minutes to form a flexible protective layer. A recording material of the present invention was obtained.

For coating 〇〇- Condensation product of isocyanate compound and polyether polyol (Tricoat G wood, manufactured by Taiho Industries) 80 parts Methyl ethyl ketone 20 parts Zero Copolymer of PO and EO (PO/EO = 20/80) Average molecular weight 4 , 500, a condensation product of 6 moles of polyether polyol and 1 mole of tolylene diisocyanate.

The thus obtained recording material of the present invention was colorless and transparent.

Examples 2 to 5 Coating solutions (A) and (B) were prepared in the same manner as in Example 1 using the following compositions, and coated on the same polyethylene terephthalate film as used in Example 1. An ink-receiving layer and a protective layer were similarly provided to obtain four types of translucent recording materials of the present invention.

Polyvinylpyrrolidone (PVPK-90, manufactured by GAF)
o% DMF solution 88 parts Novolac type phenol resin (Regitop PSK-2320, manufactured by Gunei Chemical Co., Ltd.) 10% DMF solution 12 parts
l-Hydroxyethyl cellulose (HEC AH-15, manufactured by Fuji Chemical) 5 parts water
95 parts polyvinylpyrrolidone (PVPK-90, manufactured by GAF) 10% DM
F solution 88 parts Novolac type phenol resin (Regitop PSK-2320, manufactured by Gunei Chemical Co., Ltd.) 10% DMF solution 1 plate to 12 parts Ethyl hydroxyethyl cellulose (E HE C-High, manufactured by Percules) 5 parts Methyl ethyl ketone 95 parts JLf1 Dish-based polyvinylpyrrolidone (PVPK-90, manufactured by GAF) 1
0% DMF solution 75 parts Inbutylene/maleic anhydride copolymer (isopan 1O, Clareisoprene) 10% DMF solution 25 parts 1 liter
L-5 hydroxyethyl cellulose (HEC AH-15, manufactured by Fuji Chemical) 5 parts water
95 parts polyvinylpyrrolidone (manufactured by PVPK-90GAF) 10% D
MF solution 75 parts Inbutylene/maleic anhydride copolymer (isopan 1O, Talalay isoprene) 10% DMF solution 25 parts 1 lq
LL Kogo Nitrocellulose (R5-1, manufactured by Daicel Chemical Industries, Ltd.) 5 parts Methyl ethyl ketone 95 parts Comparative Examples 1 to 2 Using the following coating solution, the coating of Example 1 was coated on the same polyethylene terephthalate film as in Example 1. Two types of recording materials for comparison were obtained in the same manner as for the ink receiving layer.

Comparison 11 Polyvinylpyrrolidone (PVPK-90, manufactured by GAF)
1o part DMF
90 parts comparison 1” Polyvinylpyrrolidone (PVPK-90, manufactured by GAF)
5 parts polyviny/lz7'/
1z)-ru (PVA-217, manufactured by Kuraray)
5 parts water
90 copies Comparative Example 3 A comparative recording material was obtained in the same manner as in Example 3, except that no protective layer was provided.

Regarding the recording materials of the above examples and comparative examples.

Inkjet recording is performed using the following four types of ink using a recording device that has an on-demand inkjet recording head that ejects ink using a piezo vibrator (discharge orifice diameter 60 pm, piezo vibrator drive voltage 70 V, frequency 2 KHz). was carried out.

On moxibustion! (Composition) C, 1, Direct Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts L-shiel (composition) C, 1, Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts 1 EL (composition) C, 1, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts 1 ether (composition) C, 1, food black 2 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 copies The evaluation results of the recording materials of the Examples and Comparative Examples are shown in Table 1.

Each evaluation item in Table 1 was measured according to the following method.

(1) Ink fixation time is the time required for the ink to dry and stop adhering to your finger when you leave the recording material at room temperature (20°C, 65% RH) after recording and touch the recorded image with your finger. was measured.

(2) The dot density was calculated using Sakura Microdensidometer PD by applying JISK7505 to the printed microdots.
The black dots were measured using M-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

(3) OHP suitability was measured as a representative example of optical equipment, and the recorded image was projected onto a screen using OHP.
Judging by visual observation, the non-recorded area is bright, the 00 (optical density) of the recorded image is high, and a clear and easy-to-see projection image with high contrast is obtained. OD is slightly low.

If the line with pitch width 0.5 shoulder layer and thickness 0.25 m cannot be clearly distinguished, Δ indicates that the non-recorded area is quite dark, the OD of the recorded image is quite low, pitch width 1 ml, and thickness 0.3 layer. A case in which a hazy line could not be clearly distinguished or a case in which a non-recorded area and a recorded image could not be distinguished was rated as "×".

(4) Linear transmittance was measured using a 323-type Hitachi self-recording spectrophotometer (manufactured by Hitachi, Ltd.), keeping the distance from the sample to the light-receiving side at approximately 9C layer, and measuring the spectral transmittance as described above ( 1) It was calculated using the formula.

(5) Regarding the formation of a polymer complex, when the respective solutions of the basic polymer and the phenolic acidic polymer were mixed, a case where there was a sudden increase in viscosity or formation of a gel was rated as 0, and a case where no gel was formed was rated as x.

(6) For blocking, after 1 hour of printing, high-quality paper was brought into close contact with the printed surface and stored for 12 hours. After storage, the case where no adhesion occurred between the recording material and the high-quality paper was rated 0, and the case where no adhesion occurred was rated X.

(7) Water resistance is rated as 0 when the printed matter is visually observed after being immersed in still water for 1 minute after printing and the image before immersion can be seen even after immersion. , If the image before immersion could not be distinguished, it was marked as ×.

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Claims (3)

[Claims] (1) An inkjet device comprising a base material, an ink-receiving layer provided on the base material, and a flexible protective layer, wherein the ink-receiving layer is made of a polymer complex of a basic polymer and an acidic polymer. Recorded material. (2) The inkjet recording material according to claim (1), wherein the protective layer is made of polyurethane. (3) The recording material according to claim (1), wherein the protective layer is made of a cellulose derivative.