WO2006001094A1

WO2006001094A1 - Coating agent for recording layer protection and recording medium coated therewith

Info

Publication number: WO2006001094A1
Application number: PCT/JP2004/019093
Authority: WO
Inventors: Kenji Nasu
Original assignee: Seiko Pmc Corporation
Priority date: 2004-06-28
Filing date: 2004-12-21
Publication date: 2006-01-05
Also published as: JP4155235B2; CN100515792C; CN1956851A; JP2006007642A

Abstract

A coating agent for recording layer protection, characterized by comprising a carboxy-modified polyvinyl alcohol (A), a polyamide-polyamine epihalohydrin (B), and polyethyleneimine (C). Preferably, it is characterized in that the carboxy-modified polyvinyl alcohol (A) has a degree of saponification of 90 to 99.5 mol%. The coating agent for recording layer protection is highly effective in imparting water resistance to a recording medium. Also provided is a recording medium having high water resistance, characterized by being obtained by applying the coating agent for recording layer protection to a recording layer.

Description

Specification

Recording layer protective coating agent and recording medium coated with the same

Technical field

TECHNICAL FIELD [0001] The present invention relates to a recording layer protective coating agent containing carboxyl group-modified polybulal alcohol, polyamide polyamine epihalohydrin and polyethyleneimine, and a recording medium coated with the same on the recording layer. More specifically, the present invention relates to a recording layer protective coating agent having excellent water resistance and a recording medium having the recording layer coated thereon. Background art

[0002] Conventionally, for the purpose of protecting the recording layer, water soluble such as polybulal alcohol, starch and its derivatives, cellulose derivatives, styrene 'maleic anhydride resins, acrylic resins, vinyl acetate resins, gelatin, casein, etc. Resin is used. Among these, polyvinyl alcohol has the properties of excellent transparency, strength, and water-based ink permeability of the coating film, and has the advantage that it can be purchased at a relatively low cost, and protects thermal recording layers and inkjet recording layers. It is used as a coating agent. However, the coating film made of polyvinyl alcohol itself may have various problems such as stickiness when wet with rainwater such as rainwater, which is weak in water resistance (water resistance). Therefore, a technique using silicon-modified polybutyl alcohol for the protective layer has been proposed (see, for example, Patent Document 1), but its water resistance is not sufficient.

[0003] Patent Document 1: JP-A-58-193189

[0004] In the protective agent for the heat-sensitive recording layer, this water resistance is particularly important. A heat-sensitive recording medium having a heat-sensitive recording layer comprising a combination of a leuco dye and a developer can form a recorded image with a relatively simple device, and is easy to maintain and easy to record. Since it has the advantage of low noise, it is applied to a wide range of fields such as measurement recorders, facsimile machines, terminal printers such as computers, POS printers, automatic ticket vending machines, barcode label printers, etc. . In particular, in recent years, the use of thermal recording media has expanded to include various tickets, receipts, bank ATMs, and gas and electrical meter reading. Become a problem There are demands for harsh characteristics like never before. In particular, for meter reading applications that are used outdoors and in rainy weather, even better water resistance than before is required.

[0005] For this reason, acetacetyl-modified resin and a polyamidoamine'-epoxychlorohydrin resin have been proposed (see, for example, Patent Document 2), and although a relatively high level of water resistance can be obtained, the effect is still unsatisfactory. That's not enough.

[0006] Patent Document 2: JP 2002-301868 A

[0007] Further, a coating agent for water-based ink recording materials comprising polybulal alcohol, a crosslinking agent, and a crosslinking aid has been proposed (see, for example, Patent Document 3), and polyamide amine picrol hydride as a crosslinking agent. Polyethyleneimine is exemplified as phosphorus and a crosslinking aid. The above proposal is for use in water-based ink recording, and it is stated that “low saponification degree is preferred”, which does not describe what kind of polyvinyl alcohol is polybutyl alcohol.

[0008] In the present invention, as described later, carboxyl-modified polybulal alcohol is an essential component, and the use of other polyvinyl alcohol cannot achieve the object of the present invention.

Therefore, the present invention is a technical idea completely different from the above proposal.

Patent Document 3: Japanese Patent Laid-Open No. 9-194787

[0011] Patent Document 4 proposes a heat-sensitive recording material having a protective layer containing carboxy-modified polybutyl alcohol, an aldehyde compound and a polyamide epoxy resin. In Patent Document 4, examples of the aldehyde compound include aldehyde starch, dartal aldehyde, darioxal, and other resins having an aldehyde group, and examples of the polyamide epoxy resin include polyamide epichlorohydrin (Patent Document). (See claim 2 of 4). The protective layer described in Patent Document 4 states that “darioxal causes intermolecular cross-linking through the hydroxyl group of carboxy-modified PVA to develop the initial water resistance, and then the reaction between the polyamide epoxy resin and the carboxynole group is allowed to occur. “It was possible to obtain a film with excellent water resistance by proceeding with time” (see column 0015 of Patent Document 4), and using compounds other than aldehyde compounds such as dalyoxal. Also resistant There is no description suggesting that a good aqueous protective layer is formed.

Patent Document 4: Japanese Patent Laid-Open No. 8-230324

Disclosure of the invention

Problems to be solved by the invention

The present invention is to provide a recording layer protective coating agent necessary for obtaining a recording medium excellent in water resistance, and to obtain a recording medium excellent in water resistance coated on the recording layer. It is a problem.

Means for solving the problem

[0014] Therefore, the present inventors have conducted extensive studies in view of the strength and the situation, and as a result, have found that the carboxynole group-modified polybulal alcohol (A), the polyamide polyamine epihalohydrin (B) and the polyethylenimine (C The present inventors have found that a recording layer protective coating agent containing) can solve the above-mentioned problems, thereby completing the present invention.

[0015] That is, the present invention provides

(1) A recording layer protective coating agent comprising a carboxyl group-modified polyvinyl alcohol (A), a polyamide polyamine epihalohydrin (B) and a polyethyleneimine (C),

(2) recording layer protective coating agent for the saponification degree of the carboxyl group-modified poly Bulle alcohol (A) is a 90- 99, 5 mole ^_0/0 (1),

(3) The recording layer protective coating agent according to (1) or (2), wherein (B) is 1 to 30 parts by weight and (C) is 1 to 30 parts by weight with respect to 100 parts by weight of (A),

(4) A recording medium produced by coating the recording layer protective coating agent of any one of (1) and (3) above on the recording layer,

(5) The recording medium according to (4), wherein the recording layer is a thermosensitive recording layer.

Is to provide.

The invention's effect

The present invention can provide a recording layer protective coating agent that imparts excellent water resistance to a recording medium, and provides a recording medium having high water resistance that is coated on the recording layer. The power to do S.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, the present invention will be described in detail. As the carboxyl group-modified polybulal alcohol (A) which is one of the recording layer protective coating agent components of the present invention, known ones (see, for example, Patent Document 5) can be used, and acrylic acid, methacrylic acid, itacone can be used. It can be obtained by copolymerization of a carboxyl group-containing polymerizable monomer such as acid or maleic acid and a monomer containing butyl acetate as a main component and then partially or completely saponifying. As for the degree of saponification, those with a high saponification degree of 90-99.5 mol% are preferred. The higher the degree of saponification, the better the water resistance. This seems to be because it becomes easier to form a molecular structure in which hydrogen bonds between hydroxyl groups are easily formed.

Patent Document 5: Japanese Patent Laid-Open No. 53-91995

[0019] The carboxyl group-modified polyvinyl alcohol (A) is not particularly limited in terms of the carboxyl group modification rate and the degree of polymerization, but preferably the modification rate is 0.01-5 mol%, the average degree of polymerization is 100. — 5000, specifically K polymer KL 118, KL-318, KM-118 manufactured by Kuraray Co., Ltd., GOHSENAL T 3 30, T 1 330H, T 1 350 etc. manufactured by Nippon Synthetic Chemical Industry Co., Ltd. It can be mentioned as a representative example.

[0020] Next, as the polyamidepolyamine epihalohydrin (B) as the second component in the recording layer protective coating agent of the present invention, a known Ames negative or low molecular weight can be used. Polyamide polyamine epihalohydrin having a low content of organic halogen compound is preferred. Known polyamide polyamine epihalohydrins include: (1) Aliphatic dibasic basic carboxylic acid and / or its derivative and polyalkylene polyamine, aliphatic dibasic basic carboxylic acid and / or its derivative 1 mol. The polyalkylene polyamine was heat-condensed to 0.88 to 0.89 mol to obtain a polyamide polyamine-containing liquid. (2) The polyamide polyamine in the polyamide polyamine-containing liquid and the secondary in the polyamide polyamine (3) diluting the reaction condensate obtained in step (2) above by reacting 0.5-1.6 equivalent of epihalohydrin with respect to the amino group at a temperature of 5-50 ° C. Examples thereof include polyamide polyamine epihalohydrin, characterized by having a step of reacting at a temperature of 30 to 80 ° C. without being diluted or diluted (for example, Patent Documents). 6). Patent Document 6: Japanese Patent Application Laid-Open No. 2002-121280

[0022] The aliphatic dibasic rubonic acid used as a raw material for the polyamide polyamine ehalohydrin (B) includes malonic acid, succinic acid, gnoretanolic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, Examples thereof include sebacic acid, brassic acid, dodecanedioic acid and the like, and aliphatic dibasic carboxylic acids having 5 to 10 carbon atoms that are readily available and inexpensive are preferable. Polyalkylene polyamines used as raw materials for the polyamidopolyamine epihalohydrin (B) include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, and the like. Diethylenetriamine, which is readily inexpensive, is preferred. Further, examples of the epihalohydrin used as a raw material for the polyamide polyamine epihalohydrin (B) include epichlorohydrin, epip oral hydrin, and the like. Therefore, it is preferable.

[0023] Next, as the third component of the recording layer protective coating agent of the present invention, polyethyleneimine (C) may be a known one (see, for example, Patent Documents 7 and 8). (C) is a compound containing at least one repeating unit represented by the following general formula (1).

[0024] [Chemical 1]

R In the formula (1), R is hydrogen, an alkyl group, an aryleno group, a pyridine group, an anolenoquinamino group, or a hydrazine group, and an alkyl group, an aryl group, a pyridine group, an anolenoquinole group. The amino group and the azine group may have a substituent. >

Patent Document 7: US Patent No. 2182306

Patent Document 8: US Patent No. 3203910

[0025] Generally, polyethyleneimine (C) can be produced by ring-opening polymerization of ethyleneimine in the presence of an acid catalyst such as hydrochloric acid or sulfuric acid. Polyethyleneimine (C) molecular weight Although it is not particularly limited, it is usually 500 to 100,000. Specific examples include Epomin SP series and P series manufactured by Nippon Shokubai Co., Ltd., polymin series and Katyofast SF manufactured by BASF.

[0026] The recording layer protective coating agent of the present invention is a carboxyl group-modified polybulal alcohol.

It is possible to prepare by mixing (A), polyamide polyamineephalohydrin (B) and polyethyleneimine (C). In general, the carboxynole group-modified polybulal alcohol (A) is sold in the form of a powder, and when used, it must be dispersed in water and dissolved by heating (cooking). Therefore, as a mixing order, polyamide polyamine epihalohydrin (B) and polyethyleneimine (C) are added sequentially or simultaneously to an aqueous solution of carboxyl group-modified polybulal alcohol (A) dissolved in advance by heating. In general, it is prepared by stirring so as to be uniform.

[0027] The mixing ratio is as follows: 1 to 30 parts by weight of polyamide polyamine epihalohydrin (B) and 1 part by weight of polyethyleneimine (C) to 100 parts by weight of carboxyl group-modified polybulal alcohol (A) Part is preferred. If the polyamide polyamineephalohydrin (B) and the polyethyleneimine (C) are less than 1 part by weight, the water resistance effect may be insufficient. On the other hand, if it exceeds 30 parts by weight, the stability of the recording layer protective coating agent may be deteriorated and the water resistance may be insufficient.

[0028] The recording layer protective coating agent of the present invention includes a carboxyl alcohol group-modified polyvinyl alcohol (A), a polyamide polyamine epihalohydrin (B), and a polyethyleneimine (C), depending on the recording method. Conventional additives can be used in combination. For example, in the case of a thermal recording method, it is a dispersant, a sensitizer, a filler, a surfactant, a thermoplastic substance, a colorant, etc. Specific examples of the filler include calcium carbonate, magnesium carbonate, silica, zinc oxide. Titanium oxide, silicon oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, kaolin, calcined kaolin, talc, surface-treated inorganic fine powders such as calcium and silica, urea-formalin resin, styrene-methacrylic acid Organic fine powders such as copolymers and polystyrene resins can be mentioned. Specific examples of thermoplastic materials include higher fatty acids or esters, amides or metal salts thereof, various waxes, and aromatic carboxylic acids. Mixtures of amides and amines, benzoic acid phenyl esters, higher linear glycols, 3,4 epoxy-hexahydro Examples thereof include dialkyl phthalates and higher ketones.

[0029] The recording medium of the present invention can be produced by coating the recording layer protective coating agent on the upper surface of the recording layer. The recording layer is composed of components suitable for various recording methods such as a thermal recording method and an ink jet printing method. For example, a recording layer suitable for a thermal recording system, that is, a thermal recording layer is a coating liquid in which various known additives and auxiliaries are dispersed in water as known leuco dyes, color developers, binders, and the like. Is formed by coating and drying on a sheet-like support such as paper, synthetic paper, or plastic film. In addition, in a recording layer suitable for an ink jet printing method, that is, an ink jet recording layer, a coating liquid in which a known pigment, binder, dye fixing agent and other various additives and auxiliary agents are dispersed in water is used for paper, synthetic paper. It is formed by coating and drying on a sheet-like support such as a plastic film.

[0030] Specific examples of the leuco dye include 3,3_bis (p-dimethylaminophenyl) monophthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalic acid. 3, 3-bis (p-dimethylamino) -6-jetylaminophthalide 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide 3-dimethylamino-6-methoxy Fluorane, 7-acetamino-3-ethylaminofluorane, 3-jetylamino-5,7-dimethylfluorane, 3-jetylamino-5,7-dimethylfluorane, 3,6_i3-methoxyethoxyfluorane, and the like.

[0031] The developer is one that reacts and develops color when heated with the leuco dye, and liquefies or vaporizes at room temperature or higher, preferably 70 ° C or higher, such as phenol, p-methylenophenol. Nore, pt-Butinolevenole, p-Phenenolehuenore, α-Naphthonore, β-Naphthol, 4,4, -isopropylidenediphenol, 4,4, -cyclohexylidenediphenol, 4,4 'isopropylidene Bis (2_t_butylphenol), 4, 4, _ (1-Methyl-n—hexylidene) diphenol, 4, 4'_isopropylidene dicatechol, 4, 4'_benzylidene diphenol, 4, 4, monoisopropylidenebis (2—black mouth phenol), phenyl 4—hydroxybenzoate, salicinoleic acid, 3-phenylsalicylic acid, 5-methylsalicylic acid, 3, 5 Di _t_ butyl salicylate, 1_ Okishi _2_ Nafute acid, m_ Okishi benzoic acid, 4-O Kishifutaru acid.

[0032] Specific examples of the binder include polybutyl alcohol, starch or modified products and derivatives thereof, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose. Norellose, gum arabic, gelatin, casein, polybulurpyrrolidone, polyacryloleamide, polyacrylic acid, styrene 'maleic anhydride copolymer, isobutylene' maleic anhydride copolymer, styrene 'butadiene copolymer, polyvinyl acetate And polyacrylic acid esters.

[0033] As a coating machine for coating the recording layer protective coating agent on the upper surface of the recording layer, an air knife coater, a curtain coater, a size press, a Finorem press, a gate roll Nore ¹ to Ta ¹ to Fure ¹ to Doko ¹ to ¹ ~, Tyco ¹ ~ ta "~, Gravureko ~~ ¹ ~, Carenta '~, Ba' ~ Cotar, etc. It can also be applied to the substrate surface by a spray coater. After coating, the recording paper having a protective layer can be obtained by removing volatile components by heat drying.

[0034] A sufficient effect can be obtained if the coating amount of the recording layer protective coating agent is 0.5 to 8 g / m ² , preferably 1 to 15 g / m ^{2 in} terms of solid content.

[0035] Although the reason why the recording layer protective coating agent of the present invention exhibits excellent water resistance is not clear, it is not clear that carboxyl group-modified polyvinyl alcohol (A) and polyamide polyamine epihalohydrin (B ) And polyethyleneimine (C), it is assumed that it is due to the formation of ionic interactions and covalent bonds. When the polyamide polyamineephalohydrin (B) and polyethyleneimine (C) are used alone and in combination with the carboxyl group-modified polyvinyl alcohol (A), the object of the present invention cannot be achieved. A synergistic effect appears only when the above three components are combined.

Example

Hereinafter, embodiments of the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to the following examples. “%” Means “% by mass” unless otherwise specified.

Synthesis example of component (B) (Synthesis of resin b)

Thermometer, condenser, stirrer, GETS A 5-liter four-necked round bottom flask equipped with a nitrogen inlet tube Chirentoriamin 702 g (6. 8 Monore), 88 ^_0/0 phosphoric acid 11. 9 g of (0.11 Monore) Charge and agitate 1169 g (8 moles) of adipic acid while stirring and raise the temperature while removing the generated water out of the system. After reacting at 135 ° C for 7 hours, add 1583 g of water gradually. Polyamide polyamine included A liquid was obtained. This polyamide polyamine-containing liquid had a solid content of 51.8%, and the viscosity when the solid content was 50% was 405 mPa's (25 ° C.). In a 500 ml four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, 125.5 g of the polyamidopolyamine-containing liquid obtained above (0.18 equivalent as a secondary amino group) and water 18 Charge 9g (45% solids), 20. C. Epoxychlorohydrin (18.3 g, 0.2 monole) was added dropwise after 30 minutes. C was heated and kept at the same temperature for 3 hours. Next, 75.3 g of water was added to adjust the solid content to 35%, then 2.94 g of 30% sulfuric acid was added, heated to 65 ° C and held at this temperature, and the viscosity of the reaction solution was 360 mPa When s (25 ° C) is reached, further dilute with 82.5 g of water, adjust the pH to 3.6 with sulfuric acid, add 1.88 g of 88% formic acid, and add resin b (polyamide polyamine epoxy). Halohydrin) was obtained.

[0037] (Example 1)

As component (A), carboxyl group-modified polybulal alcohol KL-118 manufactured by Kuraray Co., Ltd. was heated and dissolved (cooked) in water so that the solid concentration was 9%. The resin b obtained in the above synthesis example as the component (B) and Catiof ast S F (polyethyleneimine) manufactured by BASF as the component (C) were added to 100 parts of the solid content of KL-118, respectively. The resulting mixture was added to 5 parts, and further diluted with water so that the solid content concentration of KL-1118 was 7% to obtain a recording layer protective coating agent D. Table 1 shows the results of the evaluation test.

[0038] (Example 2)

A recording layer protective coating agent E was obtained in the same manner as in Example 1 except that the addition amount of the resin (b) as the component (B) was changed to the amount shown in Table 1. Table 1 shows the results of the evaluation test.

[0039] (Comparative Example 1-6)

The recording layer protective coating agent g-1 was prepared in the same manner as in Example 1 except that the components (A), (B), (C), other components, and the amount added were changed as shown in Table 1. Obtained . Table 1 shows the results of the evaluation test.

[0040] [Table 1] Record protection

(A) Component 100 parts (I) Component (C) Component Other component Water resistance test 1 Coining agent

Example 1 D xyl group modification 5 5 4

Example 2 E Calfosyl group modification 10 5 5

Comparative Example 1 g Xyl group modification 10 3

Comparative Example 2 h Calfosyl group modification 10 1

Comparative Example 3 i Unmodified 5 5 1

Comparative Example 4 j Calfosyl group modification 5 3

Comparative Example 5 k Silicon modification 5 1

Comparative Example S 1 Carboxyl modified 1

[0041] Abbreviations in the above table are shown below.

[0042] Carboxyl group-modified: carboxyl group-modified polyvinyl alcohol (KL-1118 manufactured by Kuraray Co., Ltd.)

Unmodified: Unmodified polybulal alcohol (PVA-117 manufactured by Kuraray Co., Ltd.), Silicon modified: Silicon-modified polybulal alcohol (R-2105 manufactured by Kuraray Co., Ltd.) <Water resistance test 1>

The water resistance test method for the recording layer protective coating was as follows: a square film (30 mm x 30 mm, thickness 50 zm) was prepared at a drying temperature of 50 ° C, and the film was immersed in a 50 ° C water bath for 1 hour. This was done by measuring the degree of later swelling. The level of water resistance was shown stepwise by the ranks up to 51 shown below, depending on the result of the degree of swelling. In order to solve the problems of the present invention, a water resistance level of 4 or higher is required.

Swelling degree = (film area after test) ÷ (film area before test)

5: Swelling degree is less than 2.5 times.

4: Swelling degree is 2.5 times or more and less than 3 times.

3: Swelling degree is 3 times or more and less than 4 times.

2: The degree of swelling was 4 times or more, or the film was cut.

1: The film was completely cut or completely dissolved.

[0043] (Example 3)

As a filler for the recording layer protective coating agent D obtained in Example 1, silica (P-527: water) Sawa Chemical Industry Co., Ltd.) is mixed and stirred so that the concentration of the solids in the liquid is 2%, and is mixed with the roll paper ST138B41 (thermal recording paper without a protective layer) manufactured by Sharp Document System Co., Ltd. After coating the surface so that the amount was 3 g / m ² , it was dried to obtain a thermal recording medium F having a recording layer protective layer. Table 2 shows the results of the evaluation test.

[0044] (Comparative Example 7)

A thermal recording medium m having a recording layer protective layer was obtained in the same manner as in Example 3 except that the recording layer protective coating agent D was changed to the recording layer protective coating agent i. Table 2 shows the results of the evaluation test.

[0045] [Table 2]

The water resistance test method for the thermosensitive recording medium was a drop of water on the protective layer, left for 30 minutes and then reciprocated 10 times with a finger to evaluate the water resistance state (wetlab test method).

◯: The coating film is not removed at all.

X: A coating film is taken.

Claims

The scope of the claims

[1] Carboxyl group-modified polybutyl alcohol (A), polyamide polyamine epihalohydrin

A recording layer protective coating agent comprising (B) and polyethyleneimine (C).

2. The recording layer protective coating agent according to claim 1, wherein the saponification degree of the carboxyl group-modified polybulal alcohol (A) is 90 99.5 mol%.

[3] Carboxyl group-modified polyvinyl alcohol (A) 100 parts by weight of polyamide polyamine epihalohydrin (B) 1 to 30 parts by weight and polyethyleneimine (C) 1 to 30 parts by weight The recording layer protective coating agent according to claim 1 or 2, wherein

[4] A recording medium produced by coating the recording layer protective coating agent according to any one of claims 1 to 3 on the recording layer.

5. The recording medium according to claim 4, wherein the recording layer is a thermosensitive recording layer.