JPH09142007A - Ink jet recording paper - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an ink jet paper having high ink absorption, dimensional stability, excellent running property, and economically advantageous. SOLUTION: Freeness consisting of vegetable fibers (Canadian
Standard Freeness) Paper made using 600 ml or less of pulp, containing 8% by weight or more of a compound containing fluorite water as a filler per absolute dry pulp.
deral Test Method Standard No.101 Method 4046, the 10% cutoff time in the decay characteristic of the charging potential is 60 at the measurement at 20 ° C and 20% RH.
A coating layer is provided on the support within a second.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to ink strike-through,
The present invention relates to an ink jet recording sheet having no cockling and excellent in antistatic property.

[0002]

2. Description of the Related Art Ink jet recording has no process such as development and fixing, the apparatus is simple, plain paper can be used, and high quality paper can be used.
A wide range of recording media such as coated paper and film can be selected, and it is possible to easily record color and graphic characters easily. It also has the features of low noise, low cost, and high-speed printing.

If the ink supply amount of ink jet recording is a monochromatic solid portion, for example, 8 g / m ² of ink is transferred,
In the darkest part of the color record, Cyane, Magenta,
Ink of four colors of Yellow and Black overlap and U
Even if CR (Cyane + Magenta + Yellow ink is replaced with Black ink) image processing is performed, the ink supply amount is 200 to 300%. In color recording, high image quality can be obtained by providing a coating layer that has a high function of adsorbing and retaining dyes in ink and excellent color reproducibility.
When the recording paper continuously absorbs a large amount of ink, it partially expands in the recording area and causes wrinkles (cockling), which may cause contact troubles with the recording head and guides and stains. The expansion and contraction of leads to curling of the recording paper.

Further, since the coating type ink jet recording body uses a support having a high volume specific resistance such as high-quality paper, it is easily charged with electricity, and when it is printed by a printer such as being caught in a roll of a recording apparatus. There was a problem that it was easy to cause poor delivery. Defect feeding is a general term for double feeding of paper, paper jam, empty feeding of paper, and folding of the ears. These are insufficient rigidity of paper, curl of paper, large and small friction coefficient,
Although it is caused by static electricity or the like, a plurality of factors may be involved or other factors may be involved. For this reason, the support is subjected to a conductivity-imparting treatment, but the commonly used electrification agents (inorganic salts such as sodium chloride, quaternary ammonium salts, alkyl sulfonates, conductive resins) are deliquescent and sticky. There was a failure.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned various problems, that is, to enhance ink absorption, have dimensional stability, excellent running property, and economically. An object is to provide an advantageous ink jet paper.

[0006]

In order to solve the above problems, the present invention has the following constitution. That is, the pulp was made from vegetable fibers with a freeness (Canadian Standard Freeness) of 600 ml or less, and contained a compound containing fluorite water as a filler in an amount of 8% by weight or more based on absolute dry pulp. Stand
ard No.101 Method 4046, 10% cut-off time in the charge potential decay characteristics, 20 ℃ ・ 20%
It is an ink jet recording paper in which a coating layer is provided on a support, which has a measurement time of 60 seconds or less in an RH atmosphere.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The pulp used for producing the support of the present invention is not particularly limited as long as it is a pulp used for ordinary printing paper, information recording paper, electrophotographic transfer paper and the like. Any of chemical pulp (NBKP, LBKP, etc.), mechanical pulp (GP, CGP, RGP, TMP, etc.), and deinked waste paper pulp (DIP) may be used, or a mixture thereof may be mixed. The support targeted by the present invention has a basis weight of approximately 30 to 200 g / m ² in terms of the weight of rice.

The compound containing fluorite water used in the present invention is defined as having the following items. That is, the compound contains loosely bound water (hereinafter referred to as "fluorite water") in the "vacuum" in its structure, and the "vacuum" sufficiently contains hydrofluoric acid water. Even in the state, there is no stickiness seen in the deliquescent and efflorescence phenomena of sodium chloride, etc., and it is apparently kept dry. Even if the fluorite water contained in the compound is completely removed by means such as heating or reduced pressure, its crystal structure is not destroyed. The compound, from which fluorite water has been completely removed, immediately re-adsorbs water even in low humidity and immediately returns to the original saturated state.
Fluorine water coexists with various ions contained in the compound, and thus exhibits good electric conductivity. It is presumed that a compound containing fluorite water becomes electrically conductive due to the water incorporated therein and the ions ionized in the water. Therefore, there is an advantage that the change in the conductivity value is small due to the change in the water content in the air. In addition, since phenomena such as deliquescence and dissolution are not used, there is an advantage that the surface is not sticky.

Examples of the compound applicable to the present invention as the compound containing fluorite water include various condensed acids. Among them, natural zeolite minerals, synthetic zeolites and zeolite-like minerals are representative. . Natural zeolite minerals are called aluminosilicates and are represented by the general formula (1) below. Equation _{(1) W m Z n O} 2n · sH W ₂ 0 above formula represents a divalent and monovalent metal ions, but mostly Ca ²⁺ or Na ^+, a K ^+, rare Sr ²⁺ , Ba ²⁺
, Z is Si + Al (Si: Al> 1), and s is not constant. W is exchangeable with other cations.

These zeolite minerals have a unique "clearance" in the three-dimensional framework structure, and exchangeable cations are contained in this "clearance" together with water molecules. In addition to water, general solvents can also be adsorbed in the “clearance”, but the stronger the polarity, the more selectively it is adsorbed. There are many synthetic zeolites that have the same three-dimensional framework structure as natural zeolites and have the same basic properties as natural zeolites. Further, although minerals having the same “clearance” and the crystal structure thereof not changing by the desorption phenomenon of water molecules are the same as the zeolite minerals, minerals having a chemical composition different from that of the zeolite exist as natural and synthetic products. This is called a zeolite-like mineral and can be used in the present invention.

The zeolite minerals used in the present invention can be classified into the following six types by combining natural and synthetic, and structurally classifying them.

[0012] (1) fluoroborate stone group Anal site NaAlSi ₂ O ₆ · H ₂ O Bol sites _{(Ca, Na) AlSi 2 O} 6 · xH 2 O (x <1.0) Bisaito Ca ₁₀ Na ₂ Al ₁₀ Si ₆ P ₁₀ (H ₃ ) ₁₂ (H ₂ O) ₁₆ O ₉₆ Kehosite Zn _5.5 Ca _2.5 Al ₁₆ P ₁₆ (H ₃ ) ₁₆ (H ₂ O) ₃₂ O ₉₆

(2) Boraxoda Group Hydrosodalite Na ₅ (Al ₆ Si ₆ O ₁₂ ) (OH) ₂ Forge Stone Na _28.6 Ca _14.8 (Al _57.6 Si _134.4 O ₃₈₄ ) ・ 262.3H ₂ O Molecular Sieve A Type * Na ₁₂ (Al ₁₂ Si ₁₂ O ₂₄ ) NaAlO ₂ · 29H ₂ O X type * Na ₂ (Al ₂ Si _2.8 O _9.6 ) xH ₂ O (x = about 6) Y type * Na ₂ O.Al ₂ O ₃ ． 3-6 SiO ₂ · xH ₂ O (x = 7-9) SK type * Almost the same as forge stone

[0014] (3) Ryoufu' stone group chabazite _{(Ca.Na 2) Al 2 Si 4} O 12 · 6H 2 O Gurimenfu' stone _{(Na 2 .Ca) Al 2 Si} 4 O 12 · 6H 2 O erionite (Ca. Mg.Na ₂ .K ₂ ). Al ₂ Si ₄ O ₁₂・ 6H ₂ O Levinite Ca (Al ₂ Si ₄ O ₁₂ ) ・ 6H ₂ O Molecular sieve Similar to R type chabazite S type Similar to gmelin fluorite T type * Similar to erionite

(4) Soda Fluorite Group Soda Fluorite Na ₂ (Al ₂ Si ₃ O ₁₀ ) / 2H ₂ O Mesofluorite Na ₂ Ca ₂ (Al ₆ Si ₉ O ₃₀ ) / 8H ₂ O Scholes Fluorite Ca (Al ₂ Si) ₃ O ₁₀ ) ・ 3H ₂ O Thomson Fluorite NaCa ₂ (Al ₅ Si ₅ O ₂₀ ) ・ 6H ₂ O Eddington Fluorite Ba (Al ₂ Si ₃ O ₁₀ ) ・ 4H ₂ O Gonard Fluorite Na ₂ Ca (Al ₄ Si ₆ O ₂₀ ) ・ 6H ₂ O Rhodesite KNaCa ₂ (H ₂ Si ₈ O ₂₀ ) ・ 5H ₂ O Mountainete KNa ₂ Ca ₂ (HSi ₈ O ₂₀ ) ・ 5H ₂ O

(5) Gypsum Fluorite Group Gypsum Fluorite Ba ₂ (Al ₄ Si ₁₂ O ₃₂ ) · 4H ₂ O Kaiju Fluorite (K _x Na _1-x ) 5Al ₅ Si ₁₁ O ₃₂ · 10H ₂ O Dismond Fluorite Ca _{(Al 2 Si 2 O 5)} · 4H 2 O molecular sieve type B _{* Na 2 (Al 2 Si 3} O 10) · 5H 2 O Garonaito _{NaCa 2.5 (Al 3 Si 5 O} 16) 2 · 13.5H 2 O

(6) Morden Fluorite Group Morden Fluorite Na (AlSi ₅ O ₁₂ ) / 3H ₂ O Dachiald Fluorite (Na ₂ Ca) ₂ Al ₄ Si ₂₀ O ₄₈ / 12H ₂ O Ferrierite Na _1.5 Mg ₂ (Al _5.5 Si _30.5) O ₇₂ ) ・ 18H ₂ O Zeolone ** Same as Morden Fluorite (Note) * Synthetic zeolite manufactured by Union Carbide ** Norton

The support containing the compound containing fluorite water as used in the present invention is made from a pulp containing vegetable fibers having a freeness (Canadian Standard Freeness) of 600 ml or less, and a compound containing fluorite water as a filler. Containing 8% by weight or more per absolute dry pulp, and Federal Test Method Standard No.101 Method 4046
It is necessary that the 10% cut-off time in the attenuation characteristic of the charging potential specified in 1) is within 60 seconds in the measurement at 20 ° C. and 20% RH.

Regarding the running property of the conventional ink jet recording paper and the antistatic method and its evaluation method, the surface resistance value is controlled within a predetermined range by applying an antistatic treatment to one side or both sides of the support. However, with the method of internally adding an antistatic agent as in the present application, the Federal Test Me method
It was found that there is a strong correlation between the decay time and the runnability obtained by measuring the decay characteristic of the charging potential specified in thod Standard No.101 Method 4046.

Further, by containing 8% by weight or more of the compound containing fluorite water as a filler based on the dry pulp, the compound containing fluorite water is excellent in the property of absorbing ink, and the drying property, fixing property and strike through are excellent. (Ink strike-through property) It was found that the prevention property was excellent.

Since the support for ink jet recording paper is required to have excellent curl suitability and finish suitability in addition to the above-mentioned properties, it is preferable to satisfy the following requirements. A: An alkyl ketene dimer sizing agent is internally added, and
Coating with starch, alkyl ketene dimer sizing agent, and styrene resin mixed surface sizing agent B: Sizing degree specified in JIS P8122 for 30 seconds or more C: Static friction coefficient 0.5 to 0.6

The surface sizing agent further improves the dimensional stability and the ink jet recording suitability, that is,
It is necessary to prevent ink bleeding. For this purpose, alkyl ketene dimer sizing agent (hereinafter referred to as AK
Surface coating (abbreviated as D) is the most reliable and effective means. However, since AKD alone penetrates too much inside, it is necessary to mix starch. In addition, starch is also necessary in the sense of improving the surface strength and contributes to dimensional stability.

Further, when a surface sizing agent consisting of two components, starch / AKD, is applied, the friction coefficient becomes too low and there is a problem of unevenness in cutting. Therefore, the friction coefficient can be controlled by mixing with a styrene resin. There is a need to do. The reason for this is that unevenness causes heavy running and paper jams. The coating amount of the surface sizing agent is preferably 0.2 to ² g / m ² in order to achieve the above object.

The starch used in the present invention may be any of wheat starch, syrup starch, sweet potato starch, potato starch, tapioca starch, and modified starch thereof. Examples of the styrene resin include a styrene / maleic acid copolymer, a styrene / acrylic acid copolymer, a styrene / acrylic acid ester copolymer and the like.

Then, by appropriately combining with the internally added sizing agent, by setting the sizing degree to 30 seconds or more,
Each of the above objects is achieved. Size is the Steckigt method (J
It is a value measured by IS P8122). When ink jet recording is performed on paper having a low sizing degree, the ink bleeds in the lateral direction of the paper and clear printing cannot be performed. Therefore, in the present invention, the sizing degree is required to be 30 seconds or more.

When the coefficient of static friction is less than 0.5, the sheets are too slippery to cause unevenness in the cutting machine, and when the coefficient of static friction exceeds 0.6, two or more sheets of paper are fed in the printer. In order to prevent these, the coefficient of static friction in the above range is required.

The content of the compound containing fluorite water used in the present invention is 8 to 50% by weight based on absolute dry pulp,
The content is preferably 10 to 40% by weight, and if the content is less than this range, the characteristic effect cannot be obtained, and if the content is too large, the paper quality is deteriorated. It is also possible to blend a filler other than the compound containing fluorite water. The content in the present invention is a measured value of ash content in paper specified in JIS P8128.

As the other filler used in combination with the compound containing fluorite water, all kinds of fillers generally used as fillers for papermaking can be used. For example, general-purpose fillers such as clay, talc and calcium carbonate can be used. Can be mentioned.

Pigments in the coating layer of ink jet recording paper include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide,
Zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin and the like are used. Particularly, silicon oxide (silica) having high oil absorption is preferably used. The pigments are used as a mixture of two or more as needed.

As the binder in the ink jet coating layer, polyvinyl alcohols, modified polyvinyl alcohols, starches, cellulose derivatives such as hydroxyethyl cellulose, acrylic resins such as polyacrylic acid esters, polyacrylamide resins, Gelatin, casein, styrene-maleic anhydride copolymer,
Examples thereof include water-soluble binders such as ethylene-maleic anhydride copolymers and water-dispersible binders such as styrene-butadiene copolymers and acrylic ester-butadiene copolymers. In order to improve the performance such as water resistance against these binders, in addition to a curing agent, a waterproofing agent for ink (fixing agent), a dispersant such as sodium dioctylsulfosuccinate, a surfactant, a fluorescent dye, an antiseptic agent. Agents, pH adjusters, etc. are added as necessary. The mixing ratio of the pigment and the binder may be 10 to 100 parts by weight of the binder with respect to 100 parts by weight of the pigment. The coating amount is usually 5 to 30 g / m ² . These are not particularly limited as long as they satisfy the recording characteristics.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Example 1 A pulp comprising 50 parts by weight of deinked waste paper pulp deinked to a whiteness of 70% and 50 parts by weight of a 1: 1 mixed pulp of NBKP / LBKP adjusted to 500 cc with Canadian standard freeness. An ink jet recording base paper having a basis weight of 64 g / m ^{2 was} used to make a paper with a twin wire paper machine. As internal sizing agent, it is AK in terms of solid content with respect to pulp.
D (Arakawa Chemical's SPK287) 0.2% by weight and cationic starch 0.5% by weight were added, and natural zeolite (a mixture of mordenite and clinoptilolite) as a compound containing fluorite water was added as a filler to an ash content of 10% % (Vs pulp)
Was blended. 1 of modified tapioca starch as surface sizing agent
A 5 wt% glue solution was used. A surface sizing agent was prepared by adding 0.3% by weight of AKD (SS-362 manufactured by Japan PMC Co., Ltd.) and 5% by weight of a styrene-maleic acid copolymer resin to the starch paste solution based on the solid content of starch. The surface sizing agent was applied and dried on both sides of the paper with a gate roll coater so that the dry solid content was 1 g / m ² . Coating solution 1 below was applied to one side of the obtained support using a test bar coater.
The ink jet recording paper of the present invention was obtained by coating so as to be g / m ² and drying. Coating liquid 1 component Blending amount Finely powdered silicic acid 100 parts by weight Polyvinyl alcohol 50 parts by weight Water-soluble polyamide 1 part by weight Water 500 parts by weight

Example 2 Ink jet recording paper of Example 2 was prepared in the same manner as in Example 1 except that synthetic zeolite (Toyo Builder: Toyo Builder) was used instead of natural zeolite. Got

Example 3 In Example 1, the content of natural zeolite was changed to 20% ash.
The ink jet recording paper of the example was obtained in the same manner as in the example 1 except that it was blended in a weight percentage (based on pulp).

Comparative Example 1 An ink jet recording paper of Comparative Example 1 was obtained in the same manner as in Example 1 except that calcium carbonate was used instead of natural zeolite.

Comparative Example 2 In Example 1, calcium carbonate was used in place of the natural zeolite, and sodium chloride was added to the surface sizing solution.
Add 5% by weight, surface sizing agent as dry solids 1.3 g
An ink jet recording paper of Comparative Example 2 was obtained in the same manner as in Example 1 except that the ink jet recording paper was set to / m ² .

<Evaluation Method> Here, each evaluation method described in Table 1 will be described. (1) Ink jet suitability Epson ink jet printer (MJ800
According to C), printing was performed, and the drying property, the fixing property, and the strike-through (ink strike-through property) characteristics were evaluated. Drying property: Immediately after recording, the surface was strongly rubbed with gauze to check the transferability of the ink. ○ No transfer × Transfer was present Fixability: After 1 day of recording, it was immersed in tap water for 1 hour and then dried, and the readability of the print was evaluated. ○ Visible △ Difficult to see × Not visible Strike-through property: Solid recording was performed and the degree of ink strike-through from the back surface was visually evaluated. ○ No strike through △ Slightly present × strike through Runability: Cut each ink jet recording sheet into A-4 size, and prepare 30 sheets under the conditions of 20 ° C and 60% RH, and weigh 5 kg.
The load was applied to the entire surface for 8 hours, and after continuous printing, the presence or absence of double feeding was evaluated. ○ No double feed △ Double feed × Double feed occurred

(2) Evaluation method of charging property STATIC DECAY METER-406C (electro-tech systems, inc.
Federal Test Method Standard No. 101 Met
The 10% cutoff time specified in hod 4046 was measured. The measurement was performed in an atmosphere of 20 ° C. and 20% RH.

(3) Surface resistance measuring method For reference, a high resistance measuring device 4 manufactured by Hewlett-Packard Co.
Measurement was performed at an applied voltage of 100 V using 329A and resistance measurement box 16008A. The measurement was performed in an atmosphere of 20 ° C. and 20% RH.

(4) Cockling evaluation method Epson ink jet printer (MJ800
According to C), solid printing was performed while changing the ink amount, and the unevenness of the back surface of the paper immediately after recording was visually evaluated. ○ No unevenness △ Somewhat present × Uneven

[0040]

[Table 1]

[0041]

As shown in Table 1, since the ink jet recording paper of the present invention contains the compound containing fluorite water as a filler in the support, the ink jet recording suitability relating to the ink absorbability is excellent, The chargeability is low and the runnability is stable because there is no stickiness. In Comparative Example 1, double-feeding occurs due to sticking of sheets due to charging, and in Comparative Example 2, double-feeding occurs due to stickiness due to deliquescent. did.

Claims (1)

[Claims] 1. Freeness (Canadian) composed of vegetable fibers
Standard Freeness) Paper made using 600 ml or less of pulp, containing 8% by weight or more of a compound containing fluorite water as a filler per absolute dry pulp.
deral Test Method Standard No.101 Method 4046, the 10% cutoff time in the decay characteristic of the charging potential is 60 at the measurement at 20 ° C and 20% RH.
An ink jet recording paper characterized in that a coating layer is provided on a support which is within a second.