JPH08216502A - Ink jet recording sheet - Google Patents

Abstract

PURPOSE: To provide an ink jet recording sheet imparting high image density, excellent in ink absorbability and the light fastness and water resistance of an image. CONSTITUTION: An ink jet recording sheet is characterized in that a ultraviolet absorbing cationic polymer composed of a copolymer consisting of a polymerizable vinyl compd. having a quaternary ammonium base bonded thereto and a polymerizable vinyl compd. having a structural unit having ultrasonic absorbing capacity bonded thereto and a polyvinylamine copolymer with a mol.wt. of 50000 or more and a vinylamine mol ratio of 20mol% or more obtained from a copolymer of N-vinylformamide and acrylonitrile are added to the interior or at least one surface of a support or the ink receiving layer on the support. Pref., ultrafine particles of inorg. pigment, more pref., cationic colloid particles are together used in the ink receiving layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more particularly to an ink jet recording sheet having a high image density and excellent ink absorbency, image water resistance and light resistance.

[0002]

2. Description of the Related Art The ink jet recording system is a system in which minute droplets of ink are ejected by various operating principles to adhere to recording paper such as paper to record images, characters, etc., but at high speed and low noise. , Easy to multicolor, great flexibility of recording pattern, no need for development-fixing,
As a recording device for various figures including Kanji and color images, it is rapidly spreading in various applications. further,
An image formed by the multicolor inkjet system can obtain a print comparable to that of the multicolor printing by the plate making system or the printing by the color photographic system. Also,
For applications requiring a small number of copies, it is being widely applied to the field of full-color image recording because it is cheaper than the photographic technique.

As an ink jet recording sheet used in this ink jet recording system, efforts have been made from the viewpoint of equipment and ink composition so as to use high quality paper or coated paper which is usually used for printing and writing. However, as the performance of inkjet recording devices has improved and the applications have expanded, such as higher-speed, higher-definition or full-color devices, it is expected that recording sheets will also have the following more advanced characteristics. Became.

(1) The recording dot density and the image density are high. (2) Image color and sharpness are good. (3) The print dot shape is good. (4) Good ink absorption. (5) The recorded image has good image storability such as water resistance, light resistance, and ozone resistance. (6) In the coat type recording sheet, the adhesiveness of the coating layer is high and the powder drop is small.

In response to such demands, some proposals have been made in the past. For example, a method of providing an ink receiving layer on a support in order to improve ink absorbency and print dot shape (Japanese Patent Laid-Open Nos. 52-9074 and 58-58).
No. 144172, etc.), a method of using a specific material that adsorbs a dye component, paying attention to the fact that the distribution state of the dye component in the ink in the ink receiving layer influences the color property and the sharpness (Japanese Patent Laid-Open No. Sho 55-55). No. 144172) is disclosed.

Further, in order to improve the water resistance, a method of impregnating the surface with a polycationic polyelectrolyte (Japanese Patent Application Laid-Open No. 5 (1999) -58242).
No. 6-84992), a water-resistant method of forming a dye and a chelate in a water-soluble ink (JP-A-55-150396), and the like.

Further, in order to improve water resistance, light resistance and ozone resistance at the same time, a basic oligomer is contained (JP-A-60-11389), and as an example using a polyvinylamine copolymer, A recording material using vinylamine that does not contain a (meth) acrylic acid monomer unit (JP-A-64-8085) is disclosed.

However, while the requirements for these characteristics are becoming more and more severe, the ink jet recording apparatus is inexpensive and the image reproducibility such as sharpness and color reproducibility and the color reproducibility are excellent at the personal computer level. Since they can be easily obtained, inkjet recording devices have changed from special recording devices used by specific people to general-purpose recording devices, and the obtained images are difficult to distinguish from printed matter and photographs. Ink absorption, water resistance,
Problems such as light resistance and ozone resistance cannot be solved. Therefore, under the present circumstances, ensuring these characteristics is an essential condition for the inkjet recording apparatus and the inkjet recording sheet.

[0009]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an ink jet recording sheet having a high print density, excellent ink absorbency, and excellent image water resistance and light resistance.

[0010]

DISCLOSURE OF THE INVENTION As a result of intensive studies in view of the above, the present inventor has invented the ink jet recording sheet of the present invention. That is, the inkjet recording sheet of the present invention comprises a UV-absorbing cationized polymer comprising a copolymer of a polymerizable vinyl compound having a quaternary ammonium salt group and a polymerizable vinyl compound having a structural unit having an UV-absorbing ability. A polyvinylamine copolymer having a molecular weight of 50,000 or more and a vinylamine molar ratio of 20 mol% or more obtained from a copolymer of N-vinylformamide and acrylonitrile is contained in at least one of the inside and the surface of the support. It is characterized by.

In the ink jet recording sheet of the present invention, it is preferable that an ink receiving layer containing an ultrafine particle inorganic pigment as a main component is provided on a support. More preferably, an ink receiving layer composed of the ultraviolet absorbing cationized polymer, the polyvinylamine copolymer, and the ultrafine particle inorganic pigment is provided.

In the ink jet recording sheet of the present invention, preferably, the structural unit having an ultraviolet absorbing ability is 2-
It is a hydroxybenzophenone residue or a 2-hydroxybenzotriazole residue.

Further, the ink jet recording sheet of the present invention comprises an ink receiving layer provided on a support, and the composition of the ink receiving layer comprises a polymerizable vinyl compound having a quaternary ammonium salt group and an ultraviolet absorbing ability. A UV-absorbing cationized polymer consisting of a copolymer with a polymerizable vinyl compound having a structural unit having a molecular weight of 50,000 or more, and vinylamine in a molar ratio obtained from a copolymer of N-vinylformamide and acrylonitrile. It is characterized by containing a polyvinylamine copolymer of 20 mol% or more.

The ink jet recording sheet of the present invention will be described in detail below.

In the ink jet recording sheet of the present invention, a specific ultraviolet absorbing cationized polymer and a polyvinylamine copolymer are used in combination inside or on the support or in the ink receiving layer provided on the support. The light resistance and the water resistance can be further improved by containing the above.

In order to improve the water resistance of direct dyes and acid dyes contained in water-based inks for ink jet recording,
It is self-evident that the fixing and water-proofing of the dye by the reaction of the anionic part of the dye and the cationic substance are effective. On the other hand, the use of a tertiary or quaternary cationic substance having a strong cationic property tends to promote fading, and light resistance and water resistance are contradictory properties. In neutral papermaking, it is necessary to use a tertiary or quaternary cationic polymer in order to exert sufficient cationicity, and when a vinylamine containing no (meth) acrylic acid monomer unit is used, The water resistance was insufficient.

The primary amine is said to exhibit almost no cationic property in a neutral atmosphere, but the polyvinylamine copolymer of the present invention has a polymer structure even at pH 7 or above. Does not lose its cationic character. Therefore, acidic paper having an extraction pH of 6 or less, which is made in an acidic atmosphere, is naturally used. Even neutral paper having an extraction pH of 6 to 9 or an alkaline paper, which is made in a neutral to weakly alkaline atmosphere, has a water resistance of a water-soluble dye. There was a feature that it was obtained and the light resistance was not lowered.

The polyvinylamine copolymer of the present invention having 20% by mole or more of vinylamine obtained by copolymerizing N-vinylformamide and acrylonitrile and having a molecular weight of 50,000 or more is used as a fixing agent for water-soluble ink in the inside of a support or on the surface thereof. Water resistance could be imparted by including it in at least one side or in the ink receiving layer.

However, the polyvinylamine copolymer having a vinylamine ratio of 20 mol% or less does not provide sufficient water resistance, and the polyvinylamine copolymer having a small molecular weight has a pulp and a coating of the polyvinylamine copolymer. The fixing property to the layer was deteriorated, and it exuded together with the dye, which was not preferable from the viewpoint of water resistance.

The polyvinylamine copolymer of the present invention is
For example, Japanese Patent Application Laid-Open No. 58-23809 and Japanese Patent Application Laid-Open No. 1-4
It is a copolymer as exemplified in JP-A-0694.

As the monomers for synthesizing the polyvinylamine copolymer, other than N-vinylformamide,
Examples thereof include N-vinylacetamide, N-vinylpropionamide, methyl N-vinylcarbamate, ethyl N-vinylcarbamate, and isopropyl N-vinylcarbamate. Examples of the monomer to be copolymerized with N-vinylformamide include acrylonitrile, (meth) acrylic acid ester composed of alcohol having 1 to 4 carbon atoms and (meth) acrylic acid, acrylamide, (meth) acrylic acid and the like. Of these, acrylonitrile and acrylamide are particularly preferable.

In the ink jet recording sheet of the present invention, the UV-absorbing cationized polymer, when used in combination with the above-mentioned polyvinylamine copolymer, exhibits an ink-fixing function and a UV-absorbing function. The light resistance and water resistance can be further improved.

In the UV-absorbing cationized polymer of the present invention, structural units having UV-absorbing ability, that is, 2-hydroxybenzophenone residue, 2-hydroxybenzotriazole residue, etc., are bonded to the main chain of the polymerizable vinyl compound monomer. And a polymerizable vinyl compound having a quaternary ammonium salt group bonded thereto.

The copolymerization ratio (p / q) in the copolymer of the polymerizable vinyl compound (p) having a structural unit having ultraviolet absorption ability and the polymerizable vinyl compound (q) having a quaternary ammonium salt group is , Can be set appropriately. The water-soluble or self-dispersible UV-absorbing cationized polymer can be obtained by changing the ratio of p and q. For example, when the ratio of the polymerizable vinyl compound to which a quaternary ammonium salt group is bound is reduced, the water-soluble type is shifted to the self-dispersible type.

As the structural unit having an ultraviolet absorbing ability,
A 2-hydroxybenzophenone derivative, a 2-hydroxybenzotriazole derivative, a salicylic acid derivative, a cyanoacrylate derivative, and the like, preferably a 2-hydroxybenzophenone derivative and a 2-hydroxybenzotriazole derivative can be mentioned. For example, they are exemplified as follows. be able to.

1) 2-Hydroxybenzophenone derivative 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfo Benzophenone, 2,
4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, bis (2
-Methoxy-4-hydroxy-5-benzoylphenyl) methane, 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4- (2-acryloyloxy) ethoxybenzophenone, 2 -Hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone, 2-hydroxy-4- (2-methyl-2)
-Acryloyloxy) ethoxybenzophenone and the like.

2) 2-Hydroxybenzotriazole derivative 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-)
Butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-3 ', 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-
3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-t-amylphenyl) benzotriazole, 2- {2'-hydroxy-3'-(3 ", 4",
5 ", 6" -tetrahydrophthalimidomethyl) -5 '
-Methylphenyl} benzotriazole, 2,2-methylenebis {4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol}, 2- {2'- Hydroxy-5 '-(methacryloyloxy) phenyl} benzotriazole, 2-
{2'-hydroxy-5 '-(acryloyloxy) phenyl} benzotriazole, 2- {2'-hydroxy-3'-t-butyl-5'-(methacryloyloxy)
Phenyl} benzotriazole, 2- {2'-hydroxy-3'-methyl-5 '-(acryloyloxy) phenyl} benzotriazole, 2- {2'-hydroxy-
5 '-(methacryloyloxypropyl) phenyl}-
5-chlorobenzotritriazole, 2- {2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl} benzotriazole, 2- {2'-hydroxy-
5 '-(acryloyloxyethyl) phenyl} benzotriazole, 2- {2'-hydroxy-3'-t-butyl-5'-(methacryloyloxyethyl) phenyl} benzotriazole, 2- {2'-hydroxy-
3'-methyl-5 '-(acryloyloxyethyl) phenyl} benzotriazole, 2- {2'-hydroxy-5'-(methacryloyloxypropyl) phenyl}
-5-chlorobenzotriazole, 2- {2'-hydroxy-5 '-(acroyloxybutyl) phenyl}-
5-methylbenzotriazole, {2-hydroxy-3
-T-butyl-5- (acryloyloxyethoxycarbonylethyl) phenyl} benzotriazole and the like.

3) Salicylic Acid Derivatives Phenyl salicylate, pt-butylphenyl salicylate, p-octylphenyl salicylate and the like.

4) Cyanoacrylate-based derivatives 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano-3,3'-diphenyl acrylate and the like.

The polymerizable vinyl compound having a quaternary ammonium salt group is a polymerizable vinyl compound having a copolymerizable polymerizable vinyl compound having a tertiary amino group in the molecule as a monomer and a structural unit having an ultraviolet absorbing ability. After being copolymerized with a compound, the amino group is quaternized with an alkylating agent, or the tertiary amino group of the monomer is converted into a quaternary ammonium salt with an alkylating agent in advance, and then this is copolymerized. By doing so, it can be introduced into the ultraviolet absorbing cationized polymer.

Examples of the copolymerizable polymerizable vinyl compound having a tertiary amino group in the molecule include N, N-dimethylaminopropyl acrylate, N, N-diethylaminoethyl acrylate and N, N-dimethylaminoethyl methacrylate. , N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl methacrylate, N, N-dimethylaminobutyl methacrylate, N, N-dimethylaminoethyl acrylate, N,
N-dimethylaminopropyl acrylamide, N, N-
Examples thereof include dimethylaminoethylacrylamide, acryloylmorpholine, N-2-hydroxy-3-acryloyloxypropyl-N, N-dimethylamine, N-3-methacryloyloxy-2-hydroxypropyl-N, N-diethylamine and the like.

As the alkylating agent for converting the amino group of the polymerizable vinyl compound having a tertiary amino group into a quaternary ammonium salt, halogenated alkyls such as benzyl chloride and methyl chloride; sulfuric acid such as dimethylsulfate and diethylsulfate. Examples thereof include esters, and the betaine-type quaternary ammonium group can be obtained by reacting with monochloroacetic acid, β-propiolactone and the like.

Examples of the polymerizable vinyl compound containing a quaternary ammonium salt group include glycidyl trimethyl ammonium chloride, 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride.
Chloro-2-hydroxypropyltriethanolammonium chloride, glycidyldimethylbenzylammonium chloride, glycidyldimethylbutylammonium chloride, N-2-hydroxy-3-acryloyloxypropyl-N, N, N-trimethylammonium chloride, N-methacryloylaminoethyl -N,
N, N-dimethylbenzyl ammonium chloride, N
-Methacryloxy-N, N, N-triethylammonium ethyl sulfuric acid and the like can be mentioned.

In the ink jet recording sheet of the present invention, when the ultrafine inorganic pigment contained in the ink receiving layer on the support is used, the ink receiving layer can form a porous layer structure, so that the ink jet recording is carried out by an ink jet printer. When the sheet is hit with aqueous ink, the aqueous ink can be quickly absorbed into the ink receiving layer. As the ultrafine particle inorganic pigment, the smaller the particle size is, the more porous layer structure can be formed. Therefore, the primary particle size is 300 nm or less, preferably the primary particle size is 100 nm.
It is preferable to use an ultrafine particle inorganic pigment having a particle size of nm or less.

The following can be exemplified as the ultrafine particle inorganic pigment. For example, silica (colloidal silica), alumina or hydrated alumina (alumina sol, colloidal alumina), aluminum silicate, magnesium silicate, magnesium carbonate and the like can be mentioned. It is more preferable if the primary particles are porous, but non-porous. However, it is preferable that they are aggregated at the time of preparing the coating liquid or further aggregated at the time of drying the coating to form a porous ink receiving layer surface on the surface of the support.

[0036] Among the ultrafine inorganic pigments, -SO ₃ cationic colloidal silica is a dye component in the ink
Na group, -SO ₃ H groups, since the formation of insoluble salts by reacting with such a -NH ₂ group in water, has an ink fixing property functions, it is possible to exert an effect as a water-resistant ,
Particularly preferably used.

The cationic colloidal silica used in the present invention is obtained by coating the surface of the colloidal silica with a metal oxide hydrate which is a cation modifier to obtain cation modification, which is spherical or acicular. , Columnar, beaded,
There are various forms such as a rod shape, a plate shape, a lump shape, a fiber shape, and a spindle shape.

As the cationic colloidal silica, preferably used is a colloidal silica coated with a cation modifier composed of a metal oxide hydrate such as aluminum oxide hydrate, zirconium oxide hydrate and tin oxide hydrate. ,
In particular, cation-modified aluminum oxide hydrate is preferably used.

As a method of cation modification, US Pat. No. 3,007,878, Japanese Patent Publication No. 47-26959.
It can be carried out by the method described in Japanese Patent Publication.

The maximum minor axis of the cationic colloidal silica is 50 nm or less, preferably 30 nm or less, and the length of the colloidal silica is 300 nm or less, preferably 100 nm or less.

As the cationic colloidal silica, those which are dispersed in water in a colloidal state while maintaining the primary particle size are usually used.

In the cationic colloidal silica, the coating amount of the metal oxide hydrate which is the cation modifier is
1 with a metal oxide in terms of the silica (SiO ₂ conversion)
A range of 30% by weight is useful. The coating amount is preferably 2.5 to 25% by weight.

The cationic colloidal silica dispersion may also contain an acid component such as acetic acid, citric acid, sulfuric acid or phosphoric acid for the purpose of a colloid stabilizer.

Further, as the inorganic pigment that can be used in combination with the ultrafine particle inorganic pigment, any conventionally known one can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, synthetic amorphous silica. , Aluminum hydroxide, lithopone, zeolite, hydrohaloysite, magnesium hydroxide and the like.

Among these inorganic pigments, porous inorganic pigments are preferable, and examples thereof include porous synthetic amorphous silica, porous magnesium carbonate, porous alumina, and the like. Particularly, porous synthetic amorphous having a large pore volume. Silica is preferred.

Further, organic pigments such as styrene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins and melamine resins can be used together with the above ultrafine inorganic pigments.

As the binder used together with the ultrafine inorganic pigment, for example, polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, soybean protein, silyl modified polyvinyl alcohol. Etc .; Conjugated diene copolymer latex such as maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer; polymer or copolymer of acrylic acid ester and methacrylic acid ester, acrylic acid and methacrylic acid Acrylic polymer latex such as acid polymer or copolymer; vinyl polymer latex such as ethylene vinyl acetate copolymer; or functional group such as carboxyl group of these various polymers Functional group-modified polymer latex with monomers; water-based binders such as thermosetting synthetic resin systems such as melamine resins and urea resins; polymethylmethacrylate, polyurethane resins, unsaturated polyester resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral, A synthetic resin binder such as an alkyd resin may be used, and at least one kind may be used.

Further, a cationic resin added for the purpose of fixing a conventionally known dye can be used together.

Further, as other additives, a pigment dispersant, a thickener, a fluidity improver, an antifoaming agent, a foam suppressor, a release agent,
Foaming agents, penetrants, coloring dyes, coloring pigments, optical brighteners, ultraviolet absorbers, antioxidants, preservatives, anti-bacterial agents, water resistance agents, wet paper strength enhancers, dry paper strength enhancers, etc. It can also be blended.

The support used in the present invention is LB
Chemical pulp such as KP, NBKP, GP, PGW, RM
P, TMP, CTMP, CMP, CGP and other mechanical pulps, DIP and other waste paper pulps and other wood pulps and conventionally known pigments as main components, and binders and sizing agents and fixing agents, retention aids, cationizing agents, Starch, polyvinyl alcohol, and base paper manufactured by various devices such as Fourdrinier paper machine, cylinder paper machine, twin wire paper machine, etc. Base paper with a size press or anchor coat layer on it, art paper with a coat layer on them,
It also includes coated paper such as coated paper and cast coated paper.
Such a base paper and a coated paper may be provided with the coating layer according to the present invention as they are, or a calender device such as a machine calender, a TG calender or a soft calender may be used for the purpose of controlling the flatness. .

As the support, a polyolefin resin layer may be provided on the above-mentioned base paper, polyethylene,
Polypropylene, polyester, nylon, rayon,
It is also possible to apply it to a synthetic resin such as polyurethane, a film material of a mixture thereof, or a sheet formed by molding the synthetic resin into fibers.

The method for coating the ink receiving layer according to the present invention is carried out by using various devices such as a blade coater, a roll coater, an air knife coater, a bar coater, a rod blade coater, a curtain coater, a short dwell coater and a size press. Alternatively, it can be used off-machine.

The aqueous ink referred to in the present invention is a recording liquid composed of the following colorant, liquid medium and other additives.

The colorant is a water-soluble dye such as a direct dye, an acid dye, a basic dye, a reactive dye or a food dye.

As the solvent for the water-based ink, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, C1-C4 alkyl alcohols such as isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol, polypropylene glycol Polyalkylene glycols such as; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodig Call, hexylene glycol, an alkylene group such as diethylene glycol 2
~ 6 alkylene glycols; lower alkyl ethers of polyhydric alcohols such as glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, and triethylene glycol monomethyl ether.

Among these many water-soluble organic solvents,
Polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether are preferred.

Other additives include, for example, a pH adjusting agent, a sequestering agent, an antifungal agent, a viscosity adjusting agent, a surface tension adjusting agent, a wetting agent, a surfactant and a rust preventive agent.

The ink jet recording sheet according to the present invention is not limited to being used as an ink jet recording sheet, and may be used as any recording sheet using a liquid ink during recording. For example, an ink sheet in which a heat-fusible ink containing a heat-fusible substance, a dye or pigment as a main component is applied on a thin support such as a resin film, high-density paper, or synthetic paper is heated from the back surface of the ink sheet, An image-receiving sheet for thermal transfer recording that melts and transfers, an inkjet recording sheet that heat-melts a heat-melting ink into fine droplets for flight recording, an inkjet recording sheet that uses an ink in which an oil-soluble dye is dissolved in a solvent, photopolymerization An image receiving sheet corresponding to a light and pressure sensitive donor sheet using microcapsules containing a type monomer and colorless or colored dyes and pigments can be mentioned.

The common point of these recording sheets is that the ink is in a liquid state at the time of recording. The liquid ink permeates or spreads in the depth direction or the horizontal direction of the ink receiving layer of the recording sheet before being cured, solidified, or fixed. The various recording sheets described above require absorptivity according to their respective systems, and the inkjet recording sheet of the present invention may be used as the various recording sheets described above.

Further, the ink jet recording sheet of the present invention may be used as a recording sheet for heat-fixing the toner of the electrophotographic recording system which is widely used in copying machines, printers and the like, and an adhesive layer may be provided. It can also be used for labels.

[0061]

In the ink jet recording sheet of the present invention, a specific ultraviolet absorbing cationized polymer and polyvinylamine copolymer are provided inside or on at least one of the surfaces of the support or in the ink receiving layer provided on the support. It is characterized by containing, high image density,
Excellent ink absorption, water resistance and light resistance.

The reason is that it reacts with the dye components --SO ₃ Na group, --SO ₃ H group, --NH ₂ group, etc. in the ink to form a water-insoluble salt. It has a function and can improve water resistance.
The UV-absorbing cationized polymer is incorporated into the support or the ink-receiving layer without being affected by external conditions because the UV-absorbing structural unit is bonded to the polymerizable vinyl compound to which a quaternary ammonium salt group is bonded. Since it is fixed, it is presumed that it can contribute to the light resistance to the dye in the ink. Furthermore, it is considered that the polymerizable vinyl compound itself having a quaternary ammonium salt group bonded thereto also acts as an ink fixing agent, similar to the function of the cationic colloidal silica.

[0063]

EXAMPLES The present invention will be described in detail below with reference to examples. The present invention is not limited to this. All parts and% in the following are by weight.

Preparation examples of the polyvinylamine copolymer and the ultraviolet absorbing cationized polymer are shown below in advance.

[Preparation of Polyvinylamine Copolymer A] Preparation Example A-1 A polyvinylamine copolymer was synthesized by a known method, for example, a method based on JP-A-4-11094.

To a reactor equipped with a stirrer, a nitrogen introducing pipe and a cooling pipe, 4 g of a raw material simple substance having a molar ratio of N-vinylformamide and acrylonitrile of 45/55 and 35.9 g of demineralized water were charged. In a nitrogen gas stream, the temperature was raised to 60 ° C. with stirring, and then 10% by weight of 2,2′-azobis-2-amidinopropane dihydrochloride aqueous solution 0.12 g was added. With stirring, the temperature was maintained at 60 ° C for 3 hours to obtain a polymer. At this time, the monomer reaction rate was about 93%. Further, an equivalent amount of concentrated hydrochloric acid was added to the formyl group in the polymer, and the mixture was stirred and held at 75 ° C. for 8 hours to hydrolyze the polymer. The resulting polymer solution was added to acetone,
The precipitated and vacuum dried polymer was dissolved in demineralized water. The weight average molecular weight of this product was about 80,000. The molar ratio of vinylamine was about 40 mol% when measured according to the method for quantifying primary amine with copper- (ethylenedinitro) tetraacetic acid described in Analytical Chemistry Handbook.

Preparation Example A-2 A polymer was obtained in the same manner as in Preparation Example 1 except that the molar ratio of N-vinylformamide and acrylonitrile was changed to 24/78. The weight average molecular weight of this product is about 80,000,
The vinylamine molar ratio was 20 mol%.

Preparation Example A-3 A polymer was obtained in the same manner as in Preparation Example 1 except that the molar ratio of N-vinylformamide and acrylonitrile was changed to 24/78 and the polymerization time was set to 1 hour. This product has a weight average molecular weight of about 30,000 and a vinylamine molar ratio of 20 m.
It was ol%.

Preparation Example A-4 A polymer was obtained in the same manner as in Preparation Example 1 except that the molar ratio of N-vinylformamide and acrylonitrile was changed to 12/88. The weight average molecular weight of this product is about 70,000,
The vinylamine molar ratio was about 10 mol%.

[Preparation of UV Absorbing Cationized Polymer] Preparation Example B-1 30 g of 2- [2'-hydroxy-5 '-(methacryloyloxy) phenyl] benzotriazole, 70 g of N, N-diethylaminoethyl acrylate, ethyl cellosolve An ultraviolet absorber polymer aqueous solution was synthesized in the same manner as in Preparation Example 1 using 100 g. Subsequently, 30 g of monochloroacetic acid was added dropwise over 30 minutes, and the reaction was performed for 2 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to obtain an ultraviolet absorbing cationized polymer aqueous solution (solid content 20% by weight) of Preparation Example 1.

Preparation Example B-2 2-Hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone 30 g, N-2-hydroxy-3
-Preparation Example 1 using 70 g of acryloyloxypropyl-N, N-dimethylamine and 100 g of ethyl cellosolve
An ultraviolet absorbent polymer aqueous solution was synthesized in the same manner as in.
Subsequently, 30 g of methyl chloride was added dropwise over 30 minutes, and the reaction was performed in a nitrogen atmosphere for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to obtain an ultraviolet absorbing cationic polymer aqueous solution (solid content 20% by weight) of Preparation Example 2.

Preparation Example B-3 2- [2'-hydroxy-5 '-(methacryloyloxy) phenyl] -5-chlorobenzotriazole 30
g, N, N-diethylaminoethyl acrylate 70
g and 100 g of ethyl cellosolve, an ultraviolet absorbent polymer aqueous solution was synthesized in the same manner as in Preparation Example 1. Subsequently, 30 g of benzyl chloride was added dropwise over 30 minutes, and the reaction was performed in a nitrogen atmosphere for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to obtain an ultraviolet absorbing cationized polymer aqueous solution (solid content 20% by weight) of Preparation Example 3.

Preparation Example B-4 2-Hydroxy-4-methacryloyloxybenzophenone (30 g), N, N-dimethylaminopropyl acrylamide (70 g) and ethyl cellosolve (100 g) were provided with a Dimroth, a dropping funnel, a thermometer, a nitrogen introducing pipe and a stirrer. It was put into a separable flask and heated to 80 ° C. while introducing nitrogen from a nitrogen introducing tube. After that, 0.1 g of azobisisobutyronitrile dissolved in a small amount of ethyl cellosolve was divided into 4 portions and added dropwise over 30 minutes. After completion of the dropping, reaction was carried out for 2 hours in a nitrogen atmosphere to synthesize an ultraviolet absorbent polymer aqueous solution. Subsequently, 30 g of diethyl sulfuric acid
Was added dropwise over 30 minutes, and the reaction was performed for 2 hours under a nitrogen atmosphere. After the reaction is complete, cool to room temperature, dilute with water,
An ultraviolet absorbing cationic polymer aqueous solution (solid content 20% by weight) of Preparation Example 4 was obtained.

Example 1 70 parts of LBKP (freezing degree 450 mlcsf) and NBKP
(Freeness 480 mlcsf) To 100 parts of wood pulp consisting of 30 parts, calcium carbonate (manufactured by Okutama Kogyo; T
P-121) 17 parts, anionic neutral rosin sizing agent (manufactured by Arakawa Kagaku; NT-80) 0.08 part, Preparation Example A-1
5 parts of the polyvinylamine copolymer of Example 1, 3 parts of the UV-absorbing cationized polymer of Preparation Example B-1 and 0.5 part of a sulfuric acid band are mixed to form a pulp slurry, and the pulp slurry is used to make a paper using a Fourdrinier paper machine, An inkjet recording sheet of Example 1 made of a base paper having a basis weight of 85 g / m ² was obtained.

Example 2 Using the base paper obtained in Example 1, colloidal silica (Snowtex-YL, manufactured by Nissan Kagaku Co., Ltd., primary particle size 50 to 80 nm) 1 was further coated on the base paper as an ink receiving layer coating liquid.
00 parts, polyvinyl alcohol (PVA1 as an adhesive
(17, manufactured by Kuraray Co., Ltd.) 30 parts of an aqueous dispersion having a solid content of 10% was dried with a rod coater to obtain a solid content of 1.5
The ink jet recording sheet of Example 2 was prepared by coating, drying so as to be g / m ² and calendering.

Example 3 The base paper obtained in Example 1 was used, and a cationic colloidal silica (Snowtex-AK (3), manufactured by Nissan Kagaku Co., Ltd., primary particle diameter) was further applied on the base paper as an ink receiving layer coating liquid. 10 to 20 nm) 100 parts, and polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd.) as an adhesive, 30 parts, and an aqueous dispersion having a solid content concentration of 10% are used to obtain a dry solid content of 1.5 g / m ² using a rod coater. Was coated, dried and calendered to prepare an ink jet recording sheet of Example 3.

Example 4 Using the base paper obtained in Example 1, colloidal silica (Snowtex-YL, manufactured by Nissan Kagaku Co., Ltd., primary particle size 50 to 80 nm) 1 was further coated on the base paper as an ink receiving layer coating liquid.
00 parts, polyvinyl alcohol (PVA1 as an adhesive
17, Kuraray Co., Ltd.), 30 parts, 10 parts of the polyvinylamine copolymer of Preparation Example A-2, and 5 parts of the UV-absorbing cationized polymer of Preparation Example B-4 at a solid concentration of 10% as a rod. Example 4 was applied using a coater so that the dry solid content was 2 g / m ² , dried, and calendered.
An inkjet recording sheet of was prepared.

Example 5 The base paper obtained in Example 1 was used, and a cationic colloidal silica (Snowtex-AK (3), manufactured by Nissan Kagaku Co., Ltd., primary particle diameter) was further applied as a coating liquid for the ink receiving layer on the base paper. 10 to 20 nm) 100 parts, polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd.) 30 parts as an adhesive, polyvinylamine copolymer 10 parts of Preparation Example A-2, Preparation Example B-
An aqueous dispersion having a solid content of 10% and comprising 5 parts of the UV-absorbing cationized polymer of No. 4 was applied to a dry solid content of 2 g / m ² using a rod coater, dried, and calendered to give an example. Inkjet recording sheet No. 5 was produced.

Example 6 70 parts of LBKP (freezing degree 380 mlcsf) and NBKP
(Freeness 450 mlcsf) To 100 parts of wood pulp consisting of 30 parts, 10 parts of light calcium carbonate (manufactured by Okutama Kogyo; TP-121) and alkyl ketene dimer (trade name: size pine K903, manufactured by Arakawa Chemical Co., Ltd.). 0.1 part, sulfuric acid band 0.6 part, amphoteric starch (trade name: Cato3210, manufactured by Oji National Co., Ltd.) 0.8
The parts were mixed to form a pulp slurry, which was used for paper making with a Fourdrinier paper machine to produce a base paper having a basis weight of 80 g / m ² . Subsequently, the base paper was subjected to a size press treatment with an aqueous dispersion having a solid content concentration of 10% and comprising 20 parts of the polyvinylamine copolymer of Preparation Example A-2 and 10 parts of the ultraviolet absorbing cationic polymer of Preparation Example B-3. Was applied in an amount of 0.2 g / m ² to obtain an inkjet recording sheet of Example 6.

Example 7 The base paper prepared in Example 6 was used, and an alumina hydrate (Cataloid AS- was used as an ink receiving layer coating liquid on the base paper.
3, manufactured by Catalyst Kasei Kogyo Co., Ltd., primary particle size: about 10 nm) 100
And polyvinyl alcohol (PVA11
7, manufactured by Kuraray Co., Ltd.), 25 parts of a polyvinylamine copolymer of Preparation Example A-2, and 15 parts of an ultraviolet absorbing cationized polymer of Preparation Example B-4, and an aqueous dispersion having a solid content concentration of 15% is aired. Dry solid content 5 g / using a knife coater
The ink jet recording sheet of Example 7 was prepared by coating, drying so as to have m ^2, and calendering.

Example 8 Using the base paper prepared in Example 6, needle-shaped colloidal silica was added to silica (SiO ₂ equivalent) Al ₂ on the base paper.
Needle-like cationic colloidal silica modified with 7.0% by weight of aluminum oxide hydrate in terms of O ₃ (particle size;
Width 10 to 20 nm x length 50 to 200 nm) 100 parts,
15% solid content concentration consisting of 30 parts of polyvinyl alcohol (PVA117, Kuraray Co., Ltd.) as an adhesive, 25 parts of polyvinylamine copolymer of Preparation Example A-2, and 15 parts of UV absorbing cationic polymer of Preparation Example B-4 Example 8 was prepared by coating the aqueous dispersion of Example 1 with an air knife coater to a dry solid content of 5 g / m ² , followed by calendering.
An inkjet recording sheet of was prepared.

Comparative Example 1 An ink jet recording sheet of Comparative Example 1 was prepared in the same manner as in Example 1 except that the polyvinylamine copolymer of Preparation Example A-1 mixed in the pulp slurry of Example 1 was not used. did.

Comparative Example 2 An ink jet recording sheet of Comparative Example 2 was prepared in the same manner as in Example 1 except that the UV absorbing cationized polymer of Preparation Example B-1 mixed in the pulp slurry of Example 1 was not used. It was made.

Comparative Example 3 Preparation Example A-in an aqueous dispersion to be coated on the base paper of Example 6
An inkjet recording sheet of Comparative Example 3 was produced in the same manner as in Example 6 except that the polyvinylamine copolymer of 2 was not used.

Comparative Example 4 Preparation Example B- in an aqueous dispersion coated on the base paper of Example 6
An inkjet recording sheet of Comparative Example 4 was prepared in the same manner as in Example 6 except that the ultraviolet absorbing cationized polymer of 3 was not used.

Comparative Example 5 Preparation Example A-in an aqueous dispersion to be coated on the base paper of Example 6
An inkjet recording sheet of Comparative Example 5 was produced in the same manner as in Example 6 except that the polyvinylamine copolymer of 2 was replaced with the polyvinylamine copolymer of Preparation Example A-3.

Comparative Example 6 In the same manner as in Example 8 except that the polyvinylamine copolymer of Preparation Example A-2 in the aqueous dispersion of Example 8 was replaced with the polyvinylamine copolymer of Preparation Example A-4. An inkjet recording sheet of Comparative Example 6 was produced.

Comparative Example 7 On the base paper prepared in Example 6, the ink receiving layer coating solution used in Example 3 was dried to a solid content of 1.5 using a rod coater.
The ink jet recording sheet of Comparative Example 7 was prepared by coating, drying to give g / m ² and calendering.

The inkjet recording sheets obtained in Examples 1 to 8 and Comparative Examples 1 to 7 were evaluated by the following evaluation methods, and the results are shown in Table 1 below.

[Dot Shape Factor] An ink jet printer (IO-720: manufactured by Sharp Corporation) is used to print a single color dot of black ink, and an image analyzer (Luzex 500 is used as an evaluation of ink bleeding.
0, manufactured by Nireco Co., Ltd.), the perimeter of the dot and the area of the dot were measured, and the shape factor SF2 was calculated. Shape factor S
F2 is an index that is closer to 100 as it is closer to a perfect circle, and is practically no problem if it is 250 or less.

[Image Density] The image density is a reflection densitometer (trade name: Macbeth RD918, a product name: Macbeth RD918, which is solid printed with black ink, cyan, magenta and yellow inks).
It was measured using a Macbeth company). The higher the value is, the higher the image density is, and the better the image quality is.

[Ink Absorbency] Ink absorbency and image sharpness are determined by the boundaries between solid color solid print portions, for example, red print (magenta + yellow) and green print (cyan + yellow).
The degree of ink bleeding at the boundary portion of was visually determined. When the red printed portion and the green printed portion did not overlap and were separated, the characteristics were good, and when the overlapping was large and a black line was formed, the characteristics were bad. If the ink absorption is poor,
Since it significantly impairs the image quality (image sharpness), it does not make any sense even if other characteristics such as image density are good. In addition, as an evaluation criterion, A indicates a good characteristic, B indicates a good practically acceptable range, C indicates a practical problem, and D indicates a poor characteristic.

[Light resistance of image] Regarding the light resistance of the image, an ink jet printer (MJ-700V2C,
Solid printing of magenta ink was performed by using EPSON. The inkjet recording sheet after recording was used with a xenon arc fade meter, Atlas Ci-35f, black panel temperature 63 ° C., relative humidity 65% RH.
The color difference of the magenta ink color before and after the light irradiation for 30 hours under the above environment was measured. The color difference can be defined by the following mathematical formula 1 based on the result of measuring the color of each inkjet recording sheet before and after light irradiation according to L ^* a ^* b ^* (color specification method based on CIE). The larger the color difference, the more the color deterioration occurs. The measurement was performed using a standard light C, CR100 manufactured by Minolta. If the color difference is less than 1.0, it is almost impossible to visually recognize the color difference.

[0094]

## EQU1 ## ΔE = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 where ΔE is the color difference, ΔL ^* and Δa ^* and Δb ^* Is the difference between L ^* and a ^* and b ^* before and after light irradiation.

[Water resistance] The water resistance was measured by immersing a recording sheet solidly printed with a black ink in running water for 10 minutes and measuring the residual ratio (residual ratio = optical density after processing / optical density of original image). If the residual ratio of the optical density is 90% or more, it is good, and even 85% is a level with no practical problem.

[0096]

[Table 1]

Evaluation: From the results shown in Table 1 above, the ink jet recording sheets of Examples 1 to 8 according to the present invention had high image density, excellent ink absorbability, and excellent light fastness and water fastness. It was shown.

On the other hand, the ink jet recording sheets of Comparative Examples 1 to 7 were prepared without using either or both of the polyvinylamine copolymer and the UV absorbing cationized polymer, or the polyvinylamine copolymers outside the scope of the present invention. In the case of using both the polymer and the UV-absorbing cationized polymer, both were inferior in light resistance and water resistance.

[0099]

The ink jet recording sheet of the present invention is
The inside of the support or the surface thereof, or the ink receiving layer on the support, by containing a specific polyvinyl amine copolymer and a UV-absorbing cationized polymer, high image density, excellent ink absorbability, and It has excellent effects on light resistance and water resistance of an image.

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[Procedure amendment]

[Submission date] March 3, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0070

[Correction method] Change

[Correction content]

[Preparation of UV Absorbing Cationized Polymer] Preparation Example B-1 30 g of 2- [2'-hydroxy-5 '-(methacryloyloxy) phenyl] benzotriazole, 70 g of N, N-diethylaminoethyl acrylate, ethyl cellosolve 100 g of jim funnel, dropping funnel, thermometer, nitrogen
Put into a separable flask equipped with an element introduction tube and a stirrer
Then, while introducing nitrogen from the nitrogen introduction pipe, raise the temperature to 80 ° C.
Warmed. Then, dissolve in a small amount of ethyl cellosolve.
Divide 0.1g of zobisisobutyronitrile into 4 parts, 30 minutes
Dropped between. After dropping, react for 2 hours under nitrogen atmosphere
Then, an ultraviolet absorbent polymer aqueous solution was synthesized. Subsequently, 30 g of monochloroacetic acid was added dropwise over 30 minutes, and the reaction was performed for 2 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to obtain an ultraviolet absorbing cationized polymer aqueous solution (solid content 20% by weight) of Preparation Example 1.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0071

[Correction method] Change

[Correction content]

Preparation Example B-2 2-Hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone 30 g, N-2-hydroxy-3
-Preparation Example B using 70 g of acryloyloxypropyl-N, N-dimethylamine and 100 g of ethyl cellosolve
A UV absorber polymer aqueous solution was synthesized in the same manner as in Example 1. Subsequently, 30 g of methyl chloride was added dropwise over 30 minutes, and the reaction was performed in a nitrogen atmosphere for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to prepare an aqueous solution of ultraviolet absorbing cationized polymer of Preparation Example 2 (solid content: 20% by weight).
I got

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0072

[Correction method] Change

[Correction content]

Preparation Example B-3 2- [2'-hydroxy-5 '-(methacryloyloxy) phenyl] -5-chlorobenzotriazole 30
g, N, N-diethylaminoethyl acrylate 70
g and 100 g of ethyl cellosolve were used to synthesize an ultraviolet absorbent polymer aqueous solution in the same manner as in Preparation Example B- 1. Subsequently, 30 g of benzyl chloride was added dropwise over 30 minutes, and the reaction was performed in a nitrogen atmosphere for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to obtain an ultraviolet absorbing cationized polymer aqueous solution (solid content 20% by weight) of Preparation Example 3.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0073

[Correction method] Change

[Correction content]

[0073] Preparation Example B-4 2-hydroxy-4-methacryloyloxy benzophenone 30 g, N, N-dimethylaminopropyl acrylamide 70 g, ethyl cellosolve 100g used, the preparation
An ultraviolet absorbent polymer aqueous solution was synthesized in the same manner as in Example B-1 . Subsequently, 30 g of diethyl sulfuric acid was added dropwise over 30 minutes, and the reaction was performed for 2 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature and diluted with water to prepare an aqueous solution of ultraviolet absorbing cationized polymer of Preparation Example 4 (solid content: 20% by weight).
I got

Claims (8)

[Claims] 1. An ultraviolet ray comprising a copolymer of a polymerizable vinyl compound having a quaternary ammonium salt group bonded to at least one of the inside and the surface of the support and a polymerizable vinyl compound having a structural unit having an ultraviolet absorbing ability bonded thereto. The molecular weight obtained from the absorptive cationized polymer and the copolymer of N-vinylformamide and acrylonitrile is 50,000 or more,
An inkjet recording sheet comprising a polyvinylamine copolymer having a vinylamine molar ratio of 20 mol% or more. 2. The ink jet recording sheet according to claim 1, wherein an ink receiving layer containing an ultrafine particle inorganic pigment as a main component is provided on a support. 3. The ink jet recording sheet according to claim 1, wherein an ink receiving layer comprising the ultraviolet absorbing cationized polymer, the polyvinyl amine copolymer, and the ultrafine particle inorganic pigment is provided on a support. 4. The inkjet recording sheet according to claim 2, wherein the ultrafine inorganic pigment is a cationic colloidal particle. 5. A structural unit having an ultraviolet absorbing ability is 2-
A hydroxybenzophenone residue or a 2-hydroxybenzotriazole residue.
4. The inkjet recording sheet according to 4 above. 6. An ink jet recording sheet having an ink receiving layer provided on a support, wherein a polymerizable vinyl compound having a quaternary ammonium salt group and a structural unit having an ultraviolet absorbing ability are bound to the ink receiving layer composition. The molecular weight obtained from the ultraviolet-absorbing cationized polymer composed of a copolymer with the polymerizable vinyl compound and the copolymer of N-vinylformamide and acrylonitrile is 50,000 or more, and vinylamine is 20 mol% or more in a molar ratio. An inkjet recording sheet comprising a polyvinylamine copolymer. 7. The ink jet recording sheet according to claim 6, wherein the ink receiving layer composition contains an ultrafine particle inorganic pigment. 8. The inkjet recording sheet according to claim 6, wherein the ultrafine inorganic pigment is a cationic colloidal particle.