JP2002347331A - Material to be recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material to be recorded, which is excellent in water resistance and sticking resistance, has a small degree of bleeding, is excellent in clearness of a recorded picture and further excellent in ink absorbency. SOLUTION: In this material to be recorded, an ink absorbing layer, which consists of a vinyl alcohol-based polymer (A) and a maleic anhydride-based polymer (B) under the condition that the weight compounding ratio (B)/(A) is 0.1/99.9 to 40/60, is provided in a supporting base or on its surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink which has not only excellent water resistance and sticking resistance, but also a low degree of print bleeding, excellent clarity of recorded images, and excellent ink absorbability. The present invention relates to a recording material used for recording.

[0002]

2. Description of the Related Art As a writing instrument using a water-based ink such as a water-soluble dye ink or a pigment-dispersible ink as a recording liquid,
For example, fountain pens, water-based ballpoint pens, water-based felt pens, ceramic pens, fluorescent pens, and pen plotters using these pens are known. An ink jet recording method for recording by attaching an image or an image has become widespread.

[0003] Ink jet recording systems are being applied to facsimile machines, various printers, and the like because of low noise, easy colorization, and high speed recording. Conventionally, ordinary paper has been used as the recording material used in the ink jet recording method.However, with the recent improvements in the performance of the ink jet recording machine such as high-speed recording and multi-color recording, the recording material has been Even more advanced characteristics are being required. The required characteristics are, first, that the ink absorption speed is high, second, that the diameter of the ink dot does not become larger than necessary, and third, that the shape of the ink dot is close to a perfect circle,
Fourth, the handleability and preservability are good.
In order to satisfy these required properties, various studies have been made, such as using a vinyl alcohol-based polymer, polyacrylamide, or the like as the ink-absorbing material. However, improving the ink-absorbing property leads to a decrease in water resistance. At present, there are problems such as dropout of the ink absorbing layer upon contact with water and blurring of printing.

In recent years, as a use of the ink jet recording method on-mind, attention has been paid to an ink jet recording material for a wide format, and particularly to an advertisement used for outdoor signage. In such outdoor applications, an overcoat layer formed by laminating polyethylene is often provided on the surface of the recording material so as to withstand the exposure to the weather. However, providing an overcoat layer on the surface of the recording material leads to an increase in cost, and furthermore, it is necessary to separate the paper and the overcoat layer when collecting the recording material as used paper, which is not suitable for collection. Therefore, development of an inkjet recording material having excellent water resistance without providing an overcoat layer has been desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide not only excellent water resistance and sticking resistance, but also
It is an object of the present invention to provide a recording material having a small degree of print bleeding, excellent in clarity of a recorded image, and also excellent in ink absorbability, particularly a recording material for inkjet. Furthermore, an object of the present invention is to provide an ink jet recording material having a water-based ink absorbing layer on a base material and having excellent water resistance suitable for a wide format such as an outdoor advertisement, and optical devices such as slides and OHPs. To provide a recording material for projecting a recorded image onto a screen or the like, or an ink jet recording material having excellent transparency for observation of transmitted light such as a color display.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-mentioned problem is caused by the vinyl alcohol-based polymer (A) and the maleic anhydride-based polymer (B) in the support base or on the surface thereof. Having an ink absorbing layer in which the weight blend ratio (B) / (A) of the vinyl alcohol polymer (A) and the maleic anhydride polymer (B) is 0.1 / 99.9 to 40/60. The present invention has been found to be achieved by a recording material, and the present invention has been completed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The recording material of the present invention will be described below in more detail.

[0008] Vinyl alcohol-based polymer used in the recording material of the present invention (hereinafter sometimes abbreviated as PVA)
There is no particular limitation on the degree of polymerization of
000, preferably 150-8000, more preferably 200-6000. Here, PVA
Is measured according to JIS K6726, and PV
It is determined from the intrinsic viscosity measured in water at 30 ° C. using a resaponified and purified A. PVA polymerization degree is 1
If it is smaller than 00, the water resistance and sticking resistance of the recording material may decrease. If the degree of polymerization is greater than 10,000, the viscosity of the coating solution may increase when applied to a substrate, or the stability of the coating solution may be deteriorated.

The degree of saponification of PVA is not particularly limited, but it is usually 65 to 99.99 mol%, preferably 75 to 99.95 mol%, more preferably 80 to 99.95 mol%.
99.9 mol%. Here, the degree of saponification of PVA is J
It is measured according to IS K6726. If the saponification degree of PVA is less than 65 mol%, the water resistance of the recording material may be reduced. Further, the saponification degree of PVA is 99.9.
PVA greater than 9 mole% makes industrial production difficult.

[0010] In general, PVA can be produced by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester monomer. Vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl caproate,
Examples thereof include vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, and vinyl versatate. Vinyl acetate is preferably used. Known polymerization methods such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method can be used as the polymerization method of the vinyl ester-based monomer, but usually an alcohol such as methanol is used as a solvent. The solution polymerization method used is used. The polymerization temperature is not particularly limited, and can be arbitrarily selected usually from the range of 0 ° C to 150 ° C.

As a method for saponifying a vinyl ester polymer, a known method using an acid or base catalyst can be used. Usually, sodium alkoxide or sodium alkoxide in an alcohol solvent (which may contain a small amount of water) is used. A saponification method using a base catalyst such as sodium hydroxide or potassium hydroxide is used.

In the recording material of the present invention, when PVA contains an α-olefin unit having 4 or less carbon atoms, the water resistance of the recording material is significantly improved.
The use of modified PVA containing olefin units is recommended. The content of the α-olefin unit contained in the modified PVA is from 1 to 1 based on the number of moles of all monomer units in the polymer.
It is 20 mol%, preferably 1.5 to 18 mol%, and more preferably 2 to 15 mol%. When the content of the α-olefin unit is less than 1 mol%, the effect of the modification is insufficient. When the content of the α-olefin unit exceeds 20 mol%, the stability of the coating liquid when the recording material is applied to the substrate may be reduced.

Modified PVA containing α-olefin unit
Can be produced by saponifying an α-olefin-vinyl ester copolymer obtained by polymerizing a vinyl ester monomer in the presence of an α-olefin. The same vinyl ester polymer, polymerization method and saponification method as described above are applied to the types of the vinyl ester monomer, the method for polymerizing the vinyl ester monomer and the method for saponifying the vinyl ester polymer which can be used. It is possible.

In the recording material of the present invention, when PVA contains a silyl group represented by the following formula, the water resistance and other physical properties of the recording material are greatly improved. (Hereinafter, silyl-modified PV)
A may be abbreviated as A).

[0015]

Embedded image (Here, R ¹ represents a hydrogen atom or a hydrocarbon group having 8 or less carbon atoms which may have a substituent, and R ² has 1 to 1 carbon atoms which may have a substituent containing oxygen. 40 represents an alkoxy group or an acyloxy group, n represents an integer of 0 to 2, m represents an integer of 0 to 3, provided that the sum of n and m is 3 or less, and X represents a monovalent metal atom )

As described above, R ¹ represents a hydrogen atom or an optionally substituted hydrocarbon group having 8 or less carbon atoms. Here, the hydrocarbon group having 8 or less carbon atoms includes a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group,
An alkyl group such as an octyl group is preferably exemplified, and among them, a methyl group and an ethyl group are frequently used. The substituent may contain a heteroatom such as oxygen, nitrogen, sulfur or the like, and examples of the hydrocarbon group having this substituent include a methoxyethyl group. R ² is as described above.
1-4 carbon atoms which may have an oxygen-containing substituent
Represents an alkoxy group or an acyloxy group of 0; Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group, a lauryloxy group, an oleyloxy group, and an acetoxy group as the alkoxy group or the acyloxy group having 1 to 40 carbon atoms. Among them, methoxy, ethoxy and acetoxy groups are frequently used. X represents a monovalent metal atom, and specific examples thereof preferably include alkali metals such as sodium and potassium.

The content of the silyl group contained in the silyl-modified PVA is from 0.01 to 2 mol%, preferably from 0.03 to 1 mol%, based on the number of moles of all monomer units in the polymer.
It is 8 mol%, and more preferably 0.05 to 1.5 mol%. When the content of the silyl group is less than 0.01 mol%, the effect of improving the performance by introducing the silyl group is small or almost not improved,
If it is more than 2 mol%, the viscosity of the coating liquid when applied to the substrate may be too high, or the stability of the coating liquid may be reduced.

In the above silyl-modified PVA, the silyl group is present on the side chain or terminal of the PVA. The silyl group may be directly bonded to the side chain or terminal of PVA, or may be bonded via a linking group such as a hydrocarbon group or an oxyalkylene group that is not cleaved during saponification of the vinyl ester polymer.

The above-mentioned silyl-modified PVA can be produced by various known methods, and usually, an olefinically unsaturated monomer having a silyl group represented by the above formula,
Or a vinyl ester copolymer obtained by polymerizing a vinyl ester monomer in the presence of an olefinically unsaturated monomer having a substituent capable of forming a silyl group represented by the above formula after polymerization and saponification reaction Is saponified by the same method as described above. In the silyl group represented by the above formula, the metal atom X typified by an alkali metal such as sodium or potassium is mainly used as a base catalyst such as sodium alkoxide, sodium hydroxide, or potassium hydroxide for the above-mentioned vinyl ester copolymer. Introduced when saponifying using.

Specific examples of the olefinically unsaturated monomer having a silyl group represented by the above formula or the olefinically unsaturated monomer having a substituent capable of forming a silyl group represented by the above formula after polymerization and saponification reaction Examples include vinyltrimethoxysilane, vinyltri (β-methoxyethoxy) silane, allyltrimethoxysilane, vinyltriacetoxysilane, allyltriacetoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinylmethyldiethoxysilane, vinyl Dimethylethoxysilane, vinylmethyldiacetoxysilane, vinyldimethylacetoxysilane, vinylisobutyldimethoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltrihexyloxysilane,
Vinyl methoxy dihexyloxy silane, vinyl dimethoxy octyloxy silane, vinyl methoxy dioctyloxy silane, vinyl trioctyloxy silane, vinyl methoxy dilauroxy silane, vinyl dimethoxy lauroxy silane, vinyl methoxy dioleyloxy silane, vinyl dimethoxy oleyloxy Silane, 3- (meth) acrylamido-propyltrimethoxysilane, 3- (meth)
Acrylamido-propyltriethoxysilane, 3-
(Meth) acrylamide-propyltri (β-methoxyethoxy) silane, 2- (meth) acrylamide-2-
Methylpropyltrimethoxysilane, 2- (meth) acrylamide-2-methylethyltrimethoxysilane, N
-(2- (meth) acrylamido-ethyl) -aminopropyltrimethoxysilane, 3- (meth) acrylamido-propyltriacetoxysilane, 2- (meth) acrylamido-ethyltrimethoxysilane, 1- (meth)
Acrylamide-methyltrimethoxysilane, 3- (meth) acrylamido-propylmethyldimethoxysilane, 3- (meth) acrylamido-propyldimethylmethoxysilane, 3- (N-methyl- (meth) acrylamido) -propyltrimethoxysilane, 3 -((Meta)
Acrylamide-methoxy) -3-hydroxypropyltrimethoxysilane, 3-((meth) acrylamide-
Methoxy) -propyltrimethoxysilane, dimethyl-
3- (meth) acrylamido-propyl-3- (trimethoxysilyl) -propylammonium chloride, dimethyl-2- (meth) acrylamido-2-methylpropyl-3- (trimethoxysilyl) -propylammonium chloride and the like. .

The silyl-modified PVA can also be obtained by introducing a silyl group into PVA or a modified polyvinyl acetate containing a carboxyl group or a hydroxyl group by post-modification using a silylating agent. This method
For example, benzene, toluene which does not react with the silylating agent,
A silylating agent is dissolved in an organic solvent such as xylene, hexane, heptane, ether or acetone, and powdered PVA or the modified polyvinyl acetate is suspended in the solution under stirring, and the silylating agent is dissolved at room temperature. The reaction can be carried out by reacting a silylating agent with PVA or the above-mentioned modified polyvinyl acetate under a temperature condition up to the boiling point, or by further saponifying a vinyl acetate unit with an alkali catalyst or the like. Silylating agents that can be used for this purpose include trimethylchlorosilane,
Organohalogen silanes such as dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluorosilane,
Organosilicon esters such as trimethylacetoxysilane and dimethyldiacetoxysilane; organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane; organosilanols such as trimethylsilanol and diethylsilanediol; aminos such as N-aminoethylaminopropyltrimethoxysilane Examples thereof include organosilicon isocyanates such as alkylsilane and trimethylsilicon isocyanate.

As another method for obtaining a silyl-modified PVA, for example, a vinyl ester monomer is polymerized in the presence of an epoxy group-containing monomer such as allyl glycidyl ether or butadiene monoxide. Vinyl ester copolymer having epoxy group
A method of reacting a compound having a mercapto group and a silyl group in the same molecule, such as (trimethoxysilyl) -propylmercaptan, followed by saponification is exemplified. Also,
A vinyl ester polymer obtained by polymerizing a vinyl ester monomer using a compound having a mercapto group and a silyl group in the same molecule as a chain transfer agent, such as 3- (trimethoxysilyl) -propylmercaptan Can be obtained to obtain a silyl-modified PVA (the silyl-modified PVA obtained in this case is a terminal-modified product) by saponification of the compound. However, the method is not limited to these methods.

In the recording material of the present invention, α-
When both the olefin unit and the silyl group represented by the above formula are contained, various physical properties such as water resistance of the recording material are greatly improved. In such a modified PVA, α
The content of olefin units is from 1 to 20 mol%, preferably from 1.5 to 18 mol%, more preferably from 2 to
And the content of the silyl group is 0.01 to 2 mol%.
Mol%, preferably 0.03 to 1.8 mol%, more preferably 0.05 to 1.5 mol%. Further, as long as the gist of the present invention is not impaired, PVA used in the recording material of the present invention may be a vinyl ester unit and a saponified product thereof, an α-olefin unit, a monomer having a silyl group represented by the above formula. A monomer unit having a substituent capable of forming a silyl group represented by the above formula after polymerization and saponification reaction;
It may have more than one kind of other monomer units. Examples of such a monomer unit include α-olefins having 5 or more carbon atoms; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid and itaconic acid, and salts or carbon atoms thereof. 1-18 mono- or dialkyl esters; acrylamide, carbon number 1
-18, acrylamides such as N-alkylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, 2-acrylamidopropanesulfonic acid and salts thereof, acrylamidopropyldimethylamine and salts thereof or quaternary salts thereof; N-alkyl methacrylamide having 1 to 18 carbon atoms,
N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid and its salt, methacrylamidopropyldimethylamine and its acid salt or 4
N-vinylamides such as N-vinylpyrrolidone, N-vinylformamide and N-vinylacetamide; vinyl cyanides such as acrylonitrile and methacrylonitrile;
Vinyl ethers such as alkyl vinyl ethers, hydroxyalkyl vinyl ethers, and alkoxyalkyl vinyl ethers; polyethylene glycol allyl ether, methoxy polyethylene glycol allyl ether,
Allyl ethers having a poly (oxyalkylene) group such as polypropylene glycol allyl ether and polyethylene glycol-polypropylene glycol allyl ether; vinyl halides such as vinyl chloride, vinyl fluoride and vinyl bromide; vinylidene chloride, vinylidene fluoride and the like Halogenated vinylidenes; allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, and the like, but are not limited thereto. The content of these monomer units is not particularly limited as long as the obtained polymer is water-soluble, but is usually 10 mol% or less based on all monomer units in the polymer. Is preferred.

Further, the PV used for the recording material of the present invention
A is a terminal modified product obtained by polymerizing a vinyl ester monomer in the presence of a thiol compound such as thiolacetic acid, mercaptopropionic acid, or an alkylmercaptan having 18 or less carbon atoms, and saponifying the obtained polymer. May be.

Furthermore, a compound obtained by reacting PVA with a carbonyl group-containing compound such as formaldehyde, acetaldehyde or butyraldehyde in the presence of an acid catalyst to form an acetal or an acetoacetyl group obtained by reacting PVA with diketene is contained. PVA modified by a post-reaction such as PVA to be used may be used.

In using the above-mentioned PVA in the present invention, when dissolving the PVA in water, the PVA is dispersed in water, and if necessary, an alkali compound such as sodium hydroxide is added, followed by heating with stirring. Thereby, a uniform aqueous solution can be obtained.

The maleic anhydride polymer (B) used for the recording material of the present invention includes a copolymer of an α-olefin having 8 or less carbon atoms and maleic anhydride, and an alkyl vinyl ether having 8 or less carbon atoms and an anhydride of Examples include a maleic acid copolymer and a styrene / maleic anhydride copolymer. Among these maleic anhydride polymers, water-soluble ones are preferable, and specifically, methyl vinyl ether / maleic anhydride copolymer, ethylene / maleic anhydride copolymer, isobutene / maleic anhydride copolymer and the like are preferable. It is mentioned as a thing. These maleic anhydride polymers do not necessarily have to be used alone, and may be used as a mixture of two or more as needed.

In the recording material of the present invention, the vinyl alcohol-based polymer (A) and the maleic anhydride-based polymer (B) are contained in a weight ratio (B) / (A) of 0.1 /.
It is essential to be used in 99.9-40 / 60,
It is preferably from 0.5 / 99.5 to 30/70, more preferably from 1/99 to 25/75.

In the recording material of the present invention, PVA (A)
Is usually used alone, but may be used in combination with another water-soluble or water-dispersible resin in some cases. PVA
Other water-soluble or water-dispersible resins that can be used in combination with (A) include cellulose derivatives such as albumin, gelatin, casein, starch, cationized starch, gum arabic, methylcellulose, hydroxyethylcellulose, polyamide resins, melamine resins, Poly (meta)
Nonionic water-soluble resins such as acrylamide and polyvinylpyrrolidone, carboxymethylcellulose (CMC),
Anionic water-soluble resins such as sodium poly (meth) acrylate, sodium alginate, water-soluble polyester,
Styrene-butadiene copolymer latex (SB
R), nitrile rubber latex (NBR), water-dispersible resins such as vinyl acetate emulsion, ethylene / vinyl acetate copolymer emulsion, (meth) acryl ester emulsion, vinyl chloride emulsion, etc. It is not limited to.

In the present invention, PVA can be used in combination with particulate fillers such as synthetic silica, clay, talc, diatomaceous earth, zeolite, calcium carbonate, alumina, zinc oxide, satin white, and organic pigments. ,
It is not limited to these.

In the recording material of the present invention, a cationic resin can be used in combination as a fixing agent for ink. The cationic resin is a monomer, oligomer or polymer of a primary to tertiary amine or quaternary ammonium salt which dissociates when dissolved in water to exhibit a cationic property, and is preferably an oligomer or polymer. Specifically, dimethylamine / epichlorohydrin polycondensate, acrylamide / diallylamine copolymer, polyvinylamine copolymer, dimethyldiallylammonium chloride polymer, polyethyleneimine and the like can be exemplified, but are not limited thereto. is not.

As the support substrate used in the recording material of the present invention, any of transparent or opaque conventionally known support substrates can be used. Examples of the transparent support substrate include films such as polyester, polystyrene, polyamide, polyvinyl chloride, polymethyl methacrylate, cellulose acetate, polycarbonate, polyimide, cellophane, and celluloid, sheets, and highly transparent paper. Examples of the opaque support substrate include ordinary paper, pigment-coated paper, cloth, wood, metal plate, synthetic paper, and synthetic resin film or sheet subjected to opacity treatment.

As a method for forming an ink absorbing layer containing PVA (A) and a maleic anhydride polymer (B) in or on a supporting substrate, PVA (A) and a maleic anhydride polymer (B) are used. ), Or PVA
(A) and an aqueous solution or aqueous dispersion composed of a mixture of the maleic anhydride polymer (B) and another water-soluble resin or a water-dispersible resin and / or a filler;
Impregnated into the support substrate by a normal coating method using an air knife coater, roll coater, bar coater, blade coater, curtain coater, cast coater, or the like, or on the upper surface of the support substrate or on both upper and lower surfaces For example, a method of forming a coat layer. When the supporting substrate is paper, a method of internally adding the above aqueous solution or aqueous dispersion at the time of papermaking can be adopted. In the recording material of the present invention, having the ink absorbing layer in or on the supporting substrate means that the recording medium has the ink absorbing layer in the supporting substrate or on the surface of the supporting substrate, It means both aspects when both have an ink absorbing layer.

In the present invention, the PVA in the recording material
The total content of (A) and the maleic anhydride polymer (B) is not particularly limited, but is usually 0.1 to 200 g / m ^2.
Is preferably used in the range of
It is often used within the range of g / m ² .

[0035]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following Examples and Comparative Examples, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified. In the following Examples and Comparative Examples, PVA used for manufacturing an inkjet recording material was synthesized as follows.

(1) PVA containing ethylene units (P
Synthesis of VA-3) Synthesis Example 1 A vinyl acetate monomer was placed in a 50 L pressure reactor equipped with a stirrer, a nitrogen inlet, an ethylene inlet, and an initiator inlet.
After 0 kg and 8.0 kg of methanol were charged and heated to 60 ° C., the system was replaced with nitrogen gas by nitrogen bubbling for 30 minutes. Next, ethylene was introduced and charged so that the pressure in the reaction tank was 0.58 MPa. After adjusting the internal temperature of the reaction vessel to 60 ° C., 0.9 g of 2,2′-azobis (dimethylvaleronitrile) was added as an initiator to initiate polymerization. During the polymerization, ethylene was introduced to maintain the pressure of the reaction vessel at 0.58 MPa and the polymerization temperature at 60 ° C.
After a lapse of time, when the conversion reached 40%, the polymerization was stopped by cooling. After opening the reaction tank and removing ethylene,
The ethylene was completely removed by bubbling nitrogen gas.
Subsequently, unreacted vinyl acetate monomer was removed while occasionally adding methanol at 30 ° C. under reduced pressure, and ethylene-
A methanol solution of the vinyl acetate copolymer was obtained. Next, an alkali molar ratio (mol number of NaOH / mol number) was added to a methanol solution of the ethylene-vinyl acetate copolymer adjusted to a concentration of 35%.
Saponification was performed by adding a methanol solution of NaOH (concentration: 10%) so that the molar ratio of vinyl acetate units in the polymer was 0.08, to obtain ethylene-modified PVA (PVA-3). When the degree of saponification of PVA-3 was measured according to JIS K6726, the degree of saponification was 98.5 mol%. After the polymerization, the methanol solution of the ethylene-vinyl acetate copolymer obtained by removing the unreacted vinyl acetate monomer was n
After performing reprecipitation purification by precipitating in hexane and dissolving in acetone three times, drying under reduced pressure at 60 ° C.
A vinyl acetate copolymer was obtained. With respect to this purified ethylene-vinyl acetate copolymer, the amount of ethylene modification determined by ¹ H NMR measurement was 7 mol%. The above ethylene-
After saponifying the methanol solution of the vinyl acetate copolymer at an alkali molar ratio of 0.2, methanol-Soxhlet extraction was performed for 3 days, and then dried to obtain purified PVA. The P
The average degree of polymerization of VA was 1,000 in accordance with JIS K6726.

SYNTHESIS EXAMPLE 2, SYNTHESIS EXAMPLE 3 AND SYNTHESIS EXAMPLE 8 The procedure of Synthesis Example 1 was repeated except that the conditions such as the vinyl acetate monomer, the amount of methanol and the ethylene pressure during polymerization were changed as shown in Table 1. An ethylene-vinyl acetate copolymer was obtained. Then, ethylene-modified PVA (PVA-) was prepared in the same manner as in Synthesis Example 1 except that the polymer concentration and the amount of alkali used (alkali molar ratio) during saponification were changed as shown in Table 2.
4, PVA-5 and PVA-11) were obtained.

(2) PVA having a silyl group (PVA-
Synthesis of 6) Synthesis Example 4 A vinyl acetate monomer (21.0 k) was placed in a 50 L reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer.
g, 90 g of vinyltrimethoxysilane and 9.0 kg of methanol were charged, and degassed by bubbling nitrogen gas for 30 minutes. The temperature of the reactor was started, and when the internal temperature reached 60 ° C., 9.1 g of 2,2′-azobis (isobutyronitrile) was added to start the polymerization. %, The polymerization was stopped by cooling.
Subsequently, unreacted vinyl acetate monomer was removed while occasionally adding methanol at 30 ° C. under reduced pressure to obtain a methanol solution of a vinyl acetate copolymer. Next, a NaOH methanol solution having an alkali molar ratio of 0.03 (concentration of 1) was added to a methanol solution of a vinyl acetate copolymer adjusted to a concentration of 25%.
0%) for saponification, and a PV having a silyl group.
A (PVA-6) was obtained. JI for the degree of saponification of PVA-6
As a result of measurement according to SK6726, the degree of saponification was 9
8.0 mol%. After the polymerization, a methanol solution of the vinyl acetate copolymer obtained by removing the unreacted vinyl acetate monomer was precipitated in n-hexane, and reprecipitated by dissolving with acetone three times. Drying and a purified vinyl acetate copolymer were obtained. With respect to this purified vinyl acetate copolymer, the amount of vinyltrimethoxysilane modification determined by ¹ H NMR measurement was 0.25 mol%. After saponifying the above methanol solution of the vinyl acetate copolymer at an alkali molar ratio of 0.2, methanol Soxhlet extraction was performed for 3 days, and then dried to obtain a purified modified PVA product. The average degree of polymerization of the modified PVA was 1,750 as measured according to JIS K6726.

Synthesis Example 5, Synthesis Example 6, Synthesis Example 9 and Synthesis Example 10 Synthesis Example 4 was repeated except that the amounts of the vinyl acetate monomer, methanol, vinyltrimethoxysilane and the initiator were changed as shown in Table 1. Similarly, a vinyl acetate copolymer was obtained. Next, Synthesis Example 4 was repeated except that the polymer concentration and the amount of alkali used (alkaline molar ratio) during saponification were changed as shown in Table 2.
In the same manner as described above, PVA having a silyl group (PVA-7,
PVA-8, PVA-12 and PVA-13) were obtained.

(3) Synthesis of PVA having an ethylene unit and a silyl group (PVA-9) Synthesis Example 7 Vinyl acetate was placed in a 50 L pressure reactor equipped with a stirrer, a nitrogen inlet, an ethylene inlet and an initiator inlet. Monomer 24.
8 kg, 40 g of vinyltrimethoxysilane and 5.2 kg of methanol were charged, the temperature was raised to 60 ° C., and the system was replaced with nitrogen gas by bubbling nitrogen for 30 minutes. Next, ethylene was introduced and charged so that the pressure in the reaction tank became 0.46 MPa. After adjusting the internal temperature of the reaction tank to 60 ° C., 0.8 g of 2,2′-azobis (dimethylvaleronitrile) was added as an initiator to initiate polymerization. During the polymerization, ethylene was introduced to raise the pressure of the reaction vessel to 0.46 MPa.
The polymerization temperature was maintained at 60 ° C., and after 4 hours, the polymerization rate was 4
When it reached 0%, it was cooled to stop the polymerization. After the reaction tank was opened and ethylene was removed, nitrogen gas was bubbled through to completely remove ethylene. Subsequently, unreacted vinyl acetate monomer was removed while occasionally adding methanol at 30 ° C. under reduced pressure to obtain a methanol solution of an ethylene-vinyl acetate copolymer. Next, to a methanol solution of the ethylene-vinyl acetate copolymer adjusted to a concentration of 25%, a NaOH methanol solution (concentration: 10%) having an alkali molar ratio of 0.05 was added, and saponification was performed to convert ethylene units and silyl groups. Having PVA (PVA-9) was obtained. PVA
When the degree of saponification of -9 was measured according to JIS K6726, the degree of saponification was 98.5 mol%. After polymerization,
Ethylene obtained by removing unreacted vinyl acetate monomer
A methanol solution of the vinyl acetate copolymer was precipitated in n-hexane and purified by reprecipitation by dissolving in acetone three times.
Drying under reduced pressure at 0 ° C. gave a purified ethylene-vinyl acetate copolymer. For the purified ethylene-vinyl acetate copolymer, the amount of ethylene modification determined by ¹ H NMR measurement was 5 mol%, and the amount of modification of vinyltrimethoxysilane was 0.1%.
It was 2 mol%. After saponifying the methanol solution of the ethylene-vinyl acetate copolymer at an alkali molar ratio of 0.2, methanol-Soxhlet extraction was performed for 3 days, and then dried to obtain a purified modified PVA product. When the average degree of polymerization of the modified PVA was measured according to JIS K6726, it was 1550.

[0041]

[Table 1]

[0042]

[Table 2]

Table 3 shows details of the PVA used in the following Examples and Comparative Examples.

[0044]

[Table 3]

In Examples and Comparative Examples, various physical properties of the ink jet recording material were evaluated as follows. (1) Inkjet recording method Using a recording apparatus having a high on-demand type inkjet recording head having a discharge orifice diameter of 60 μm, the following 4
Perform color inkjet recording using color inks,
The recording characteristics were evaluated. Yellow ink (composition) CI Acid Yellow 2.3 2 parts Diethylene glycol 30 parts Water 70 parts Magenta ink (Composition) CI acid red 32 2 parts Diethylene glycol 30 parts Water 70 parts Cyan ink (Composition) Direct Blue 86 2 parts Diethylene glycol 30 parts Water 70 parts Black ink (composition) CI Direct Black 19 2 parts Diethylene glycol 30 parts Water 70 parts

(2) Ink Absorption (Ink Absorption Rate) After ink jet recording, the print on the recording material is rubbed with a finger at regular intervals until the printed portion does not change (until the print portion is not disturbed). Was measured. The shorter the time, the higher the ink absorption speed. (3) Bleeding degree The diameter of the printing dot was measured with a stereoscopic microscope, and the number of times the ink droplet became larger was measured. The lower the magnification, the less bleeding and the better the sharpness of the image. (4) Transparency The visible light transmittance (%) of the non-printed portion of the recording material for inkjet was measured with a spectrophotometer using visible light having a wavelength of 500 nm. This transmittance is defined as transparency. The higher the transmittance, the higher the transparency. (5) Water resistance After the recording material for inkjet was immersed in distilled water at 20 ° C. for 1 minute, the sheet surface was rubbed with a finger and evaluated according to the following criteria. ：: The ink absorbing layer hardly falls off. Also, when the finger is separated from the sheet surface, no stringing of the finger is observed (good sticking resistance). Δ: The ink absorbing layer was slightly dropped. In addition, two to three strings are found on the finger (sticking resistance is slightly poor). ×: The ink absorbing layer was considerably dropped. In addition, a large amount of stringing is observed on the entire surface of the finger (poor sticking resistance).

Example 1 (Preparation of mat type ink absorbing layer) PVA having a degree of polymerization of 1000 and a saponification degree of 98.5 mol%
(A) (“PVA-110” manufactured by Kuraray Co., Ltd.) (PVA
A 10% aqueous solution (b) of -1) was prepared. Silica powder (“Mizukasil P-78D” manufactured by Mizusawa Chemical Co., Ltd.) 100
To 400 parts of water, 200 parts of aqueous solution (b) was slowly added at room temperature while sufficiently dispersing by adding 400 parts of water to prepare a PVA silica aqueous dispersion. Methyl vinyl ether / maleic anhydride alternating copolymer ("GANTREZ" manufactured by ISP)
AN-119 ") 10.5 parts of a 10% aqueous solution of (B) was slowly added to an aqueous dispersion of silica in PVA while stirring at room temperature, and an appropriate amount of distilled water was further added to obtain a solid concentration of 16%.
The coating liquid was prepared. {Weight ratio: (B) / (A) = 5]
/ 95｝. When this coating liquid was left at 30 ° C. for 2 weeks, the viscosity of the coating liquid was hardly changed, and the viscosity stability was good. Next, on a polyester film having a thickness of 50 μm and a transparency of 95%, the above coating liquid was applied at a coating amount (total solid content) of 15 g / m ² @PVA (A) and methyl vinyl ether / maleic anhydride. An ink-absorbing layer was formed by hand-coating so that the total solid content of the alternating copolymer (B) was 2.6 g / m ² ｝, and dried at 100 ° C. for 3 minutes with a hot-air dryer to form an ink-jet ink. A recording material for use was obtained. Table 4 shows the results of the evaluation of this sheet.

Example 2 In Example 1, PVA (A) having a polymerization degree of 1700 and a saponification degree of 98.5 mol% (“PVA-117” manufactured by Kuraray Co., Ltd.) (PVA-2) was used as PVA. Except for the above, a coating liquid was prepared in the same manner as in Example 1 to produce a recording material. Table 4 shows the results of evaluating the obtained recording materials.

Examples 3-12 In Example 1, the type of PVA and / or 10% of the methyl vinyl ether / maleic anhydride alternating copolymer
A coating liquid was prepared in the same manner as in Example 1 except that the content of the aqueous solution was changed to the content shown in Table 4, and a recording material was manufactured. Table 4 shows the results of evaluating the obtained recording materials.

Examples 13 and 14 In Example 1, a commercial ethylene / maleic anhydride alternating copolymer (Aldrich) was used in place of the methyl vinyl ether / maleic anhydride alternating copolymer, and PVA was used.
A coating liquid was prepared in the same manner as in Example 1 except that the type of was changed to that shown in Table 4, and a recording material was manufactured. Table 4 shows the results of evaluating the obtained recording materials.

Example 15 (Production of a gloss type ink absorbing layer) PVA having a degree of polymerization of 2400 and a degree of saponification of 87.0 mol%
(A) (“PVA-224” manufactured by Kuraray Co., Ltd.) (PVA
-10) was prepared. To 100 parts of colloidal silica (“Snowtex 30” manufactured by Nissan Chemical Industries, Ltd.), 30 parts of the above PVA aqueous solution was slowly added at room temperature.
An aqueous colloidal silica dispersion of PVA was prepared. Methyl vinyl ether / maleic anhydride alternating copolymer (IS
Company G "GANTREZ AN-119") (B) 1
1.6 parts of a 0% solution was slowly added to a colloidal silica dispersion aqueous solution of PVA while stirring at room temperature, and an appropriate amount of distilled water was further added to prepare a coating solution having a solid concentration of 20%. {Bounding ratio: (B) / (A) = 5/95 °. Next, thickness 5
The above coating solution was hand-coated on a polyester film having 0 μm and 95% transparency so that the coating amount after drying was 15 g / m ^2, and dried at 100 ° C. for 3 minutes with a hot-air drier for inkjet. A recording material was obtained. Table 4 shows the results of the evaluation of this sheet.

Examples 16 to 18 In Example 15, the type of PVA and / or 10% of the methyl vinyl ether / maleic anhydride alternating copolymer were used.
A coating solution was prepared in the same manner as in Example 13 except that the content of the aqueous solution was changed to the content shown in Table 4, and a recording material was manufactured. Table 4 shows the evaluation results of the obtained recording materials.
Shown in

Comparative Examples 1 to 4 In Example 1, the type of PVA and / or 10% of the methyl vinyl ether / maleic anhydride alternating copolymer
A coating liquid was prepared in the same manner as in Example 1 except that the content of the aqueous solution was changed to the content shown in Table 4, and a recording material was manufactured. Table 4 shows the results of evaluating the obtained recording materials.

Comparative Examples 5 to 7 The same as Example 13 except that the type of PVA and the amount of the 10% aqueous solution of the ethylene / maleic anhydride alternating copolymer were changed to those shown in Table 4 To prepare a coating liquid, thereby producing a recording material. Table 4 shows the results of evaluating the obtained recording materials.

Example 19 A recording material was produced in the same manner as in Example 1 except that a substrate on which a polyethylene laminate (15 μm) was applied was used as a supporting substrate. Table 4 shows the results of evaluating the obtained recording materials.

[0056]

[Table 4]

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The recording material of the present invention is excellent in water resistance and sticking resistance, has a small degree of print bleeding, has excellent recorded image clarity, and has excellent ink absorption.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C056 EA05 FC01 2H086 BA15 BA35

Claims (4)

[Claims] The present invention comprises a vinyl alcohol-based polymer (A) and a maleic anhydride-based polymer (B) in or on a support substrate, wherein the vinyl alcohol-based polymer (A) and the maleic anhydride-based polymer ( B) Weight ratio (B) /
(A) A recording material having an ink absorbing layer having a ratio of 0.1 / 99.9 to 40/60. 2. The recording material according to claim 1, wherein the vinyl alcohol polymer (A) is a vinyl alcohol polymer containing 1 to 20 mol% of an α-olefin unit having 4 or less carbon atoms. 3. The recording material according to claim 1, wherein the vinyl alcohol polymer (A) is a modified polyvinyl alcohol having a silyl group in a molecule. 4. The recording material according to claim 1, wherein the recording material is a recording material for an ink jet.