JPH05278322A - Recording sheet - Google Patents

Abstract

PURPOSE:To provide a recording sheet having good ink absorbability, imparting good image quality and excellent in water resistance. CONSTITUTION:A recording sheet is obtained by providing a recording layer based on a quaternary ammonium salt polymer, a cation modified polyvinyl alcohol and a hydroxyl group crosslinkable compd. on at least the single surface of a plastic film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet, and more specifically, it has a high image density and a clear image color tone,
The present invention also relates to a recording sheet for an ink jet printer which has excellent ink absorbability, water resistance, and abrasion resistance.

[0002]

2. Description of the Related Art In recent years, due to the widespread use of OA, there is an increasing demand for creating and recording documents in an office, and a printer with low noise and excellent image quality is required. Inkjet printers have been put into practical use as one of printers that meet these requirements.

Ink jet printers use inks that are difficult to dry to prevent nozzle clogging.
The components of this ink are generally prepared by dissolving a binder, a dye, a solvent, an additive and the like in water. Therefore, it is necessary to use a recording sheet with good water absorption,
Usually, a special paper with good ink absorption is used.

[0004]

On the other hand, when a sheet having a low ink absorbency is used, the ink may be insufficiently dried or may not be dried at all, and if it is rubbed with a finger or overlapped, it is recorded. The part is dirty and practically unusable.

In order to improve these points and improve the ink absorbency of the substrate, for example, polyvinyl alcohol, starch, gelatin, cellulose derivatives such as hydroxyethyl cellulose and methyl cellulose, polyacrylic acid, polymethacrylic acid and the like. It has been proposed to provide a water-soluble polymer recording layer such as salts, but even if the conventional recording layer satisfies the ink absorbency, the water resistance is poor and the recording layer and recording part dissolve in water. However, there are problems that the recorded image disappears, the surface becomes sticky and the recorded image bleeds, and blocking occurs when sheets are laminated.

An object of the present invention is to solve the above problems and to provide a recording sheet having excellent ink absorbability and dye fixing property.

[0007]

A recording sheet according to the present invention for this purpose is a recording film containing a quaternary ammonium salt polymer, a cation-modified polyvinyl alcohol and a hydroxyl group-crosslinking compound as main components on at least one side of a plastic film. It consists of layers.

The material of the plastic film in the present invention includes polyester, polyolefin, polyamide, polyesteramide, polyether, polyimide,
Polyamide imide, polystyrene, polycarbonate,
Poly-P-phenylene sulfide, polyether ester, polyvinyl chloride, poly (meth) acrylic acid ester are preferred. Moreover, these copolymers, blends, and further crosslinked products can be used. Further, among the above plastic films, polyester, preferably polyethylene terephthalate, is preferable from the viewpoint of mechanical properties and workability.

The polyester in the present invention is a well-known one, for example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis-α, β (2-chlorophenoxy) ethane 4,4'-dicarboxylic acid, At least one of bifunctional carboxylic acids such as adipic acid and sebacic acid
Seeds, ethylene glycol, triethylene glycol,
A polyester obtained by polycondensing at least one kind of glycol such as tetramethylene glycol, hexamethylene glycol, decamethylene glycol and the like can be mentioned. Further, the polyester may be blended with other polymers or copolymerized within a range not impairing the object of the present invention, and may include an antioxidant, a heat stabilizer, a lubricant, a pigment, an ultraviolet absorber and the like. It may be. The intrinsic viscosity of the polyester (measured in 25 ° C. orthochlorophenol) is 0.4 to 2.0, preferably 0.5 to 1.
Those in the range of 0 are usually used.

As the polyester film used in the recording sheet of the present invention, it is possible to use a polyester film which contains fine bubbles inside and is made white by scattering light with the bubbles. The formation of these fine air bubbles causes the formation of incompatible polymers such as poly-3-methylbutene-1, poly-4 in the film matrix such as polyester.
-Methylpentene-1, polypropylene, polyvinyl-
By finely dispersing t-butane, 1,4-trans-poly-2,3-dimethylbutadiene, cellulose triacetate, cellulose tripropionate, polychlorotrifluoroethylene, etc., and stretching them uniaxially or biaxially It is formed. During the stretching, voids (air bubbles) are formed around the incompatible polymer particles, and the voids are whitened because they exhibit a light scattering action. Further, since it has fine bubbles, it has a low specific gravity and also has cushioning properties.

Further, in the present invention, it is possible to use a polyester film in which fine particles such as calcium carbonate, amorphous zeolite particles, anatase type titanium dioxide, calcium phosphate, silica, kaolin, talc and clay are used in combination. In addition to such fine particles, fine particles precipitated by the reaction of the catalyst residue and the phosphorus compound in the polyester polymerization reaction system may be used in combination.

In the recording sheet of the present invention, a recording layer containing a quaternary ammonium salt polymer, a cation-modified polyvinyl alcohol and a hydroxyl group-crosslinking compound as main components is provided on at least one side of the plastic film.

The quaternary ammonium salt polymer is a polymer having at least one quaternary ammonium salt in the repeating unit chain and, for example, poly (2-hydroxy-3-methacryloxypropyltrimethylammonium). Chloride), poly (2-hydroxy-3-methacryloxypropyltriethylammonium chloride), poly (2-hydroxy2-acryloxypropyltrimethylammonium chloride), poly (2-hydroxy3)
-Acryloxypropyltriethylammonium chloride), poly (2-methacryloxyethyltrimethylammonium chloride), poly (2-methacryloxyethyltriethylammonium chloride) poly (2-acryloxyethyltrimethylammonium chloride), poly (2-acryloxy) Ethyltriethylammonium chloride), poly (vinylbenzyltrimethylammonium chloride), poly (dimethylaminoethylmethacrylate) salt, poly (diethylaminoethylmethacrylate) salt, poly (dimethylaminoethylacrylate) salt, poly (dimethylaminoethylacrylate) ) Salt, poly (vinylbenzyltriethylammonium chloride), poly (4-vinylN-methylpyridinium chloride), , N-Dimethyl-substituted 3,5-methylpiperidinium chloride resin, poly (dimethyldiallylammonium chloride), poly (diethyldiallylammonium chloride), polyethyleneimine hydrochloride, etc. and surfactant handbook (Industrial publication, 1960) There are polymers of various quaternary ammonium salts and piperidinium salts described, but other known polymers having various quaternary ammonium salts can be used.

In particular, poly (2-hydroxy-3-methacryloxypropyltrimethylammonium chloride),
Poly (2-hydroxy-3-methacryloxypropyltriethylammonium chloride), poly (2-hydroxy2-acryloxypropyltrimethylammonium chloride), poly (2-hydroxy3-acryloxypropyltriethylammonium chloride), poly (2
-Methacryloxyethyltrimethylammonium chloride), poly (2-methacryloxyethyltriethylammonium chloride), poly (2-acryloxyethyltrimethylammonium chloride), poly (2-acryloxyethyltriethylammonium chloride), poly (dimethylaminoethyl) Methacrylate) salt, poly (diethylaminoethylmethacrylate) salt, poly (dimethylaminoethylacrylate) salt,
A salt of poly (diethylaminoethyl acrylate) is the preferred polymer.

The quaternary ammonium salt polymer may be used alone or as a mixture of two or more kinds. Furthermore, the fourth
It may be a copolymer of a quaternary ammonium salt and styrene or an acrylic acid ester. The acrylic acid ester as used herein refers to an acrylic acid ester and a methacrylic acid ester, and is preferably an ester of an aliphatic alcohol. For example, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-hydroxyethyl methacrylate and the like can be mentioned. The primary ammonium salt polymer desirably contains a hydroxyl group, and particularly 2-hydroxyethyl acrylate,
2-Hydroxyethyl methacrylate and the like are preferably used.

Specific examples of the quaternary ammonium salt polymer used in the present invention include Elekondo (manufactured by Soken Chemical Industry Co., Ltd.), Chemistat (manufactured by Sanyo Kasei Co., Ltd.) and Colcoat (manufactured by Colcoat). , SAT-5 (manufactured by Nippon Pure Chemical Co., Ltd.), Dow ECR (manufactured by Dow Chemical Co., Ltd.) and the like, but not limited thereto.

The cation-modified polyvinyl alcohol is
A polyvinyl alcohol having a cationic group in its main chain or side chain, which can be generally obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate. ..

The cation-modified polyvinyl alcohol preferably used in the present invention is vinyloxyethyltrimethylammonium chloride, trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride, trimethyl- (2-acrylamido-2,2). −
Dimethylethyl) ammonium chloride, trimethyl- (3-methacrylamidopropyl) ammonium chloride, N- (1,1-dimethyl-3-dimethylaminopropyl) acrylamide, N- (3-dimethylaminopropyl) methacrylamide, N-vinyl A copolymer obtained by copolymerizing vinyl acetate and an ethylenically unsaturated monomer having a cationic group such as quaternary ammonium salt group such as imidazole, N-vinyl-N-methylimidazole and quaternary compounds thereof, is obtained. It can be obtained by saponification by a conventional method.

The cationic group unit content of the cation-modified polyvinyl alcohol is preferably in the range of 0.1 to 10 mol%. The saponification degree of the vinyl acetate unit of the cation-modified polyvinyl alcohol varies depending on the content of the cationic group and should be selected depending on the use of the recording sheet.
It is usually selected from the range of 50 to 100 mol%, preferably 70 to 99%. The degree of polymerization of the cation-modified polyvinyl alcohol is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually in the range of 500 to 3000.

In the recording sheet of the present invention, it is necessary that the recording layer contains the above-described quaternary ammonium salt polymer, cation-modified polyvinyl alcohol, and a hydroxyl group-crosslinking compound. is there.

Examples of the hydroxyl group-crosslinking compound include aldehyde compounds, carboxy compounds, activated vinyl compounds, polyvalent metal-containing compounds, methylol compounds and acid anhydrides. The hydroxyl group-crosslinking compound preferably used in the present invention is a water-soluble melamine resin, and a suitable water-soluble melamine resin is methylol melamine, particularly methylated methylol melamine resin. These resins are manufactured by methods well known in the industry.

The mixing ratio of the quaternary ammonium salt polymer and the cation-modified polyvinyl alcohol is 1/4 to 4/1, preferably 1/3 to the weight ratio of the quaternary ammonium salt polymer / cation-modified polyvinyl alcohol. It is selected from the range of 3/1, and more preferably from 1/2 to 2/1. When the amount of the quaternary ammonium salt polymer / cation-modified polyvinyl alcohol is less than 1/4, the water resistance of the recording layer to be formed is poor, and when it exceeds 4/1, the compatibility of the mixed solution becomes poor, which is not preferable.

The amount of the hydroxyl group-crosslinking compound added to the quaternary ammonium salt polymer and the cation-modified polyvinyl alcohol mixture is 50/1 to 2/1, preferably 20/1 to 20% by weight of the mixture / hydroxyl group crosslinkable compound. It is selected from the range of 5/1. 50 / mixture / hydroxyl-crosslinkable compound
If it is less than 1, the water resistance of the recording layer to be formed is less effective than in the case where no hydroxyl group-crosslinking compound is added, and if it exceeds 2/1, the hydrophilicity of the recording layer to be formed decreases.
Not preferable.

In the recording sheet of the present invention, inorganic and / or organic particles may be dispersed in order to improve the blocking resistance of the recording layer. Examples of the inorganic particles include silica, clay, talc, diatomaceous earth, calcium carbonate, barium sulfate, aluminum silicate, synthetic zeolite, alumina, zinc oxide, mica and the like. As the organic particles, for example, polymethylmethacrylate, polystyrene, copolymers thereof, polyvinyl chloride, polyethylene, polypropylene, polyvinylidene chloride, plastic pigments such as polycarbonate can be preferably used, but are not limited to these. Absent.

In the recording layer of the recording sheet of the present invention,
Known additives such as a defoaming agent, a coatability improving agent, a thickening agent, an antistatic agent, an antioxidant, an anti-UV agent, a dye and the like may be contained within the range of not impairing the characteristics of the present invention. The coating thickness of the recording layer is not particularly limited, but is 1 to 30 μm,
It is preferably 2 to 20 μm. If it is thinner than this range, the ink absorbency is poor, and if it is thicker than this range, the workability is deteriorated, which is not preferable.

The coating method of the recording layer is not particularly limited,
Gravure coat method, reverse coat method, kiss coat method,
Known methods such as a die coating method and a bar coating method can be applied. At this time, not only the coatability is improved by applying a known surface treatment such as a corona discharge treatment in air or other atmosphere on the film, or a primer treatment, if necessary, before coating. The recording layer can be more firmly formed on the film. The coating agent concentration and the coating film drying conditions are not particularly limited, but it is desirable that the coating film drying conditions be performed within a range that does not adversely affect various characteristics of the substrate.

[0027]

EXAMPLES First, methods for measuring various characteristics in the present invention will be described. (1) Recordability Personal computer 98not manufactured by NEC Corporation
Canon Inc. bubble jet printer BJ-
10 V was connected, a character pattern was recorded by inkjet recording, image quality and ink absorbency were evaluated, and recording property was determined as follows. The image quality was evaluated by visual observation with a magnifying glass, and the ink absorbency was evaluated by the degree of smearing of the recording layer with ink by rubbing the recorded portion once with a finger immediately after recording. [Printing quality] ◎: Very good (dots are uniform and clear) ○: Good Δ: Slightly inferior ×: Dotted flow, repelling, bleeding, etc. [Ink absorbency] ◎: Very good (recording layer is completely absent) No stain) ○: Good Δ: Slightly inferior ×: Ink is removed and the recording layer is stained.

(2) Water resistance of recording layer Evaluation was carried out by dipping the cotton swab in water and rubbing the recording layer lightly. ⊚: Good (the recording part does not fall off even after rubbing 20 times) ○: Slightly good (the recording part falls off after rubbing 10 to 20 times) ×: Poor (falls off after less than 10 times)

(3) Adhesion of recording layer The adhesion of the substrate / recording layer is determined by cross-cutting (1
00 pieces / cm ² ) and put 4 on the cross-cut surface.
A cellophane tape (CT-24, manufactured by Nichiban Co., Ltd.) was attached at 5 °, and reciprocated 10 times with a load of about 5 kg using a hand roller, and the cellophane tape was forcibly peeled in the direction of 180 ° to peel the recording layer. The degree was observed and evaluated. ◎: Very good (no peeling) ○: Good (peeling area less than 5%) △: Slightly inferior (peeling area 5% or more and less than 20%) ×: Poor (peeling area 20% or more)

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Example 1 Polyethylene terephthalate homopolymer chips produced by a conventional method (intrinsic viscosity: 0.62, melting point: 25)
(9 ° C.) was used to obtain a 75 μm biaxially stretched polyester film by a conventional method. The surface of the polyester film thus obtained was subjected to corona discharge treatment. Next, a recording layer having the following composition was used as a recording layer on the surface treated with corona discharge, and was applied by a gravure coater so that the thickness after drying was 5 g / cm ^2, and dried at 140 ° C. for 5 minutes, and then the recording sheet of the present invention Got The properties of the recording sheet thus obtained are as shown in Table 1, and the image quality and ink absorbency were good, and the water resistance was also excellent.

[Coating composition] 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride and 2
-Hydroxyethyl acrylate was polymerized by a conventional radical polymerization method to prepare a quaternary ammonium salt polymer. Next, trimethyl- (3-methacrylamidopropyl) ammonium chloride and vinyl acetate are copolymerized, and the resulting copolymer is saponified by a conventional method so that the content of the monomer unit having a cationic group is 3 mol. %, A cation-modified polyvinyl alcohol having a degree of saponification of vinyl acetate units of 88 mol% and a degree of polymerization of 1750 was prepared. The quaternary ammonium salt polymer, the cation-modified polyvinyl alcohol, and a water-soluble melamine resin (manufactured by Sanwa Chemical Co., Ltd.,
Nicalac MW-22) has a solid content ratio of 50/50/10.
Was dissolved in a water-methyl alcohol solvent to give a coating composition having a solid content of 10%.

Example 2 A recording sheet of the present invention was obtained in the same manner as in Example 1 except that the quaternary ammonium salt polymer (Colcoat NR-121X-9, manufactured by Colcoat) was used. The properties of the recording sheet thus obtained are as shown in Table 1, and the image quality and ink absorbency were good, and the water resistance was also excellent.

Example 3 In Example 1, a quaternary ammonium salt polymer (manufactured by Sanyo Kasei Co., Ltd., Chemistat 6300H), cation-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA-C) was used.
A recording sheet of the present invention was obtained in the same manner except that (-318-2A) was used. The properties of the recording sheet thus obtained are as shown in Table 1, and the image quality and ink absorbency were good, and the water resistance was also excellent.

Examples 4, 5, 6 In Example 1, a quaternary ammonium salt polymer (manufactured by Soken Chemical Industry Co., Ltd., Elecond B-149) / cation-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA) -C3
18-2A) / water-soluble melamine resin (manufactured by Sanwa Chemical Co., Ltd., Nikarac MW-12LF) at a solid content ratio of 5
A recording sheet of the present invention was obtained in the same manner except that the recording sheets were 0/50/5, 10, 20. The properties of the recording sheet thus obtained are as shown in Table 1, and the image quality and ink absorbency were good, and the water resistance was also excellent.

Example 7 In Example 6, quaternary ammonium salt polymer / cation-modified polyvinyl alcohol / water-soluble melamine resin /
A recording sheet of the present invention was obtained in the same manner except that polymethacryl fine particles (manufactured by Sekisui Kasei Co., Ltd., average particle diameter 8 μm) were added so that the solid content ratio was 50/50/20/2. The properties of the recording sheet thus obtained are as shown in Table 1, and the image quality and ink absorbency were good, and the water resistance was also excellent.

Comparative Example 1 A recording sheet was obtained in the same manner as in Example 1 except that the quaternary ammonium salt polymer was not added. The properties of the recording sheet are as shown in Table 1 and the water resistance of the recording layer was poor.

Comparative Example 2 A recording sheet was obtained in the same manner as in Example 4, except that the cation-modified polyvinyl alcohol was not added. The properties of the recording sheet are as shown in Table 1 and were inferior in ink absorbency.

[0038]

[Table 1]

[0039]

EFFECT OF THE INVENTION The recording sheet of the present invention has good adhesion to a substrate,
It has excellent water resistance, image quality, and ink absorbability, and can be preferably used in recording sheets for monochrome and color inkjet printers, offset printing, flexographic printing, and the like. Furthermore, the recording sheet of the present invention utilizes the excellent ink absorbency, adhesion of the substrate, etc., for other inks such as thermal ink receivers including sublimation type, electrophotographic toner receivers, and fabric ink receivers. It can also be applied as a toner receiver.

Claims (3)

[Claims] 1. A recording sheet comprising a plastic film and a recording layer containing a quaternary ammonium salt polymer, a cation-modified polyvinyl alcohol and a hydroxyl group-crosslinking compound as main components on at least one surface of the plastic film. 2. The recording sheet according to claim 1, wherein the quaternary ammonium salt polymer contains a hydroxyl group. 3. The recording sheet according to claim 1, wherein the hydroxyl group-crosslinking compound is a water-soluble melamine resin.