WO1991002653A1

WO1991002653A1 - Heat-sensitive recording paper

Info

Publication number: WO1991002653A1
Application number: PCT/JP1989/001121
Authority: WO
Inventors: Yoshimi Ishibashi; Katsumi Moronuki
Original assignee: Honshu Paper Co., Ltd.
Priority date: 1989-08-23
Filing date: 1989-10-31
Publication date: 1991-03-07
Also published as: EP0439612A1; DE68918287D1; EP0439612A4; EP0439612B1; DE68918287T2

Abstract

This invention relates to heat-sensitive recording paper. More particularly, in heat-sensitive recording paper including a heat-sensitive recording layer containing a basic colorless dye and an acidic material causing coloration of the basic colorless dye upon heating on a substrate, the present invention relates to heat-sensitive recording paper wherein the support contains used paper and the content of the residual surfactant contained in the support is below 1,000 ppm. According to the present invention, heat-sensitive paper which is economical and has high storage stability and high reliability with respect to a thermal head can be obtained.

Description

Specification

Thermal recording paper

Technical field

The present invention relates to a thermosensitive recording paper, and more particularly, to a thermosensitive recording paper which is inexpensive, has high storage stability and high reliability for thermal heads.

Background art

The heat-sensitive recording method using a basic colorless dye and an acidic substance that causes the basic colorless dye to develop a color when heated has characteristics that a developing step is not required and that the maintenance of the hardness is easy. It is widely used for battery rims, printers, and recorders of measuring instruments.

At present, high quality paper that does not contain waste paper is used as a support for thermal recording paper.However, due to the demand for cost reduction of thermal recording paper and the viewpoint of recycling paper pulp, thermal recording paper will be used in the future. It is possible that more and more waste paper is being introduced into the support.

By the way, when waste paper is blended in the support of the thermal recording paper, the color print density decreases (fading) during high-humidity storage, the background frays during high-temperature storage, and further long-term running tests are performed. When this was done, there were many problems such as the thermal head coming off the dot (partial damage to the thermal head).

Accordingly, an object of the present invention is to provide a thermosensitive recording paper which is inexpensive and resource-saving, and has high storage stability and high reliability for thermal heads.

The present inventors have conducted intensive studies to achieve the above object, and as a result, the support of the heat-sensitive recording paper contains waste paper, and the amount of the residual surfactant contained in the support has been reduced to 100 m or less. By doing the above eyes I found that the target could be achieved. Further, it has been found that providing a barrier layer between the support and the heat-sensitive recording layer can provide a further excellent effect.

By the way, waste paper is generally made from a combination of the following three steps.

5 That is,

(1) Disintegration The waste paper is treated with mechanical force and chemicals using a pulp paper to loosen the fibers, and the printing ink is separated from the fibers.

(2) Dust removal-· · Remove foreign substances (such as plastic) and dust contained in waste paper. ·

, ο (3) Deinking Remove the printing ink separated from the fiber by a floatation method or a cleaning method.

When the support of the thermal recording paper simply contains waste paper, the thermal recording paper may be discolored during storage at high humidity, affected by the surfactant of the deinking agent used in the deinking step of step (3). Causes background blur when stored at high temperatures,

. 5 In addition, the dropout of the thermal head may occur. The present inventors have studied the effects of these surfactants. As a result, for example, the surfactants are polyalkylene alkylene alkyl ether, polyoxyalkylene alkyl ether, and polyoxyethylene alkyl ether. . Nonionic surfactants such as pyrene block polymer or quaternary compounds

20 In the case of surfactants such as ammonium salts, alkyl trimethyl chloride, cetyl trimethyl ammonium chloride, σ-lide, and alkyl benzyl ammonium chloride, etc. Discoloration during high-humidity storage and background capri during high-temperature storage occur, while surfactants are fatty acid ken, alkylbenzenesulfonate, high-grade

_{2 5} Turkey Lumpur sulfates, "- O Lev Lee Nsuruhone bets, to be impaired significantly reliability for head to support one circle in the case of § two sign nonionic surfactants such as dialkyl Kirusuruhosaku Shine DOO Find Was. The present invention has been made based on such findings.

Disclosure of the invention

That is, the present invention provides a heat-sensitive recording paper provided with a heat-sensitive recording layer containing a basic colorless dye and an acidic substance that causes the basic colorless dye to develop a color when heated. The present invention relates to a thermosensitive recording paper characterized in that the content of the residual surfactant contained in the support is not more than 0 ppm by ppm.

Hereinafter, the present invention will be described in detail.

As the support sheet used for the thermal recording paper of the present invention, a sheet containing waste paper is used.

Waste paper is a generic term for used paper or paperboard, or cuttings of such paper.

The support of the present invention may be formed entirely of waste paper. However, it is preferable to contain waste paper in an amount of 60% or less. If the amount is more than this, the strength of the support tends to decrease and the whiteness tends to deteriorate.

The content of the residual surfactant contained in the support is generally required to be 10 to 0 ppm or less, preferably 800 ppm or less. As the content of the residual surfactant increases, the storage stability deteriorates, and the dots easily drop out.

Examples of the base t raw colorless dye used in the heat-sensitive recording paper of the present invention include 3,3-bis (p-dimethylaminophenyl) 16-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3— (p-dimethylaminophenyl) 1-3_ (1,2—dimethyltin-ru 3 ) Phthalide, 3 — (p — dimethylaminophenyl) 1 3 — (2 — methylindole — 3 — yl) phthalide, 3, 3 — bis (1, 2 —Dim Chill Din —Rou 3 — 1) 5-dimethylaminophthalide, 3, 3-bis (1, 2-dimethylindol-3-yl) 1 6-dimethylaminophthalide, 3, 3-bis ( 9 —Ethylka rubazoru 3 —yl) 100 — dimethylaluminophthalide, 3,3 —bis (2—phenylindole 1 3 3 一 yl) 1 6 —dimethylaluminophthalide , 3 — Ρ — dimethylaminophenol 3 — (1 — methylvilol 13 — yl) 1 6 — trimethylamine dyes such as dimethylaminophthalide, 4,4'-bis (dimethylamino) benzhydrylbenzyl ether, 、 -Νσ-phenyl-co-auramin, Ν—2,4,5—trichlorophenyl

Diphenylmethanine dyes such as I.sup.0-nyllo-co-alumina, benzoyzolero-yco-methylene dyes, and p-nitrobenzene dyes such as p-nitrobenzene's ylero-ikomethylene blue; 3—methylsilyl pyro-naphthovirane, 3—ethylsilyl pyronaphthovirane, 3—vinyl pyrazine naphthopyran, 3 ^ nilyl pyrazine naphthopyran,

I 5 3 — Spiro dyes such as methyl naphtho (6 '— methoxybenzo) spiropyran, 3 — propyl spirodibenzopyran, and rhodamine B — anilinolactor Lactam dyes, such as lactam, α-damin (ρ—dichloroaniline) lactam, and rhodamine (ο—chloroanilino) lactam , 3 — dimethylamino 7 — methoxyfluoran, 3

2 0—Metichiamino 6—Metoxyfluoran, 3—Jetilamino 7—Metoxifluoran, 3—Metichiamino 1-7—Black mouth Fluorolan, 3—Jetilaumi No 6 — methyl 7 _ black mouth Fluorolan, 3 — getylamino 1-6, 7 — dimethylthiofluoran, 3 1 (Ν-ethyl ρ — tri-luino) 1 7 — methylthiofluoran , 3 — cetirumimino 7 — Ν-acetyl-Ν Ν — methilaminofluoran, 3 — cetiliamino 7-Ν — methilaminofluoran, 3 — getylamino 1-7 — dibenzylami Fluorine, 3 — di 7- N-methyl- N- ^?ジルァジル 3 3 ジェジェチル — — — メジルジルメメメメメジルジルジルジルジルジルジルジルジルジルジルジル— (Ν _ethyl-1 ρ — tolujino) 1 6 —methyl_7 1-phenylaminofluoran, 3 — (Ν-etchil 1 ρ — tolujino) 1 6 —.methyl 7 — (Ρ — toluin gino) Fluoro oran, 3 — gethylamino 6 — methyl 7 — phenylamino fluoran, 3 — gethylamino 1 7 — (2 — carbometoxif Enillumino) Fluoran, 3 — (Ν-ethyl) — 6 — methyl 1 7 — Phenylamine 3 — (cyclohexyl) KIRURU:-METHYLAMINO) 1-6-METHYL 7 FUNILA Luoran, 3 — pyrrolidino 1 6 — methyl 7 phenylamino fluoran, 3 — Piveridino 6 — methyl 7 — phenylamino fluoran, 3 — getylamino 6 — methyl _ 7 — xylidinofluoran, 3 — getylamino 7 — (0 — 口 mouth phenylamino) fluoran, 3 — dibutylamino 7 — (0 — クB mouth phenylamino) fluoran, 3-pi sigma 6-methyl-7-ρ-butylphenylamino fluoran, 3-getylamino 6-methyl -7 2 Rinofluoran, 3—Dibutylamino 1-6—Methyl 1 7—Anilinofluoran, 3— (Ν-Ethyl 1Ν—Isoamyl) Amino 1-6—Methyl 7 — Fluoran dyes such as anilinofluoran You.

Various types of inorganic or organic acidic substances that cause a basic colorless dye to develop color when heated are known, for example, activated clay, acidified clay, and Attano. Inorganic acidic substances, such as rugitite, bentonite, colloidal iron, aluminum silicate, etc., 4-t.er L-butyl phenol, 4-hydroxifenox, Naphthol, β—Naph Toll, 4—Hydroxy acetonol, 4—tert—year-old quilt, 2,2'-jijidokijifenol, 2,2'— Methylene bis (4-methyl-6-ter (_—isobutylphenol), 4, 4'-isopropylidenbis (2 —! _ E—butylphenol) 4, A ' sec—butylene diphenyl, 4—phenylphenol, 4,4′-isopropyl dendylphenol (bisphenol A), 2,2′—methylenebis (4-chlorophenol), metal quinone, 4, 4 '-cyclohexyl benzoyl, 4-hydroxybenzyl benzoate, 4-hydroxy Π-Dimethyl xyphthalate, hydroquinone monobenzyl ether, novolak-type phenolic resin, phenol weight Benzoic acid, benzoic acid, P-tert-butylbenzoic acid, trichlorobenzoic acid, telephthalic acid, 3-sec-butyl-14-hydroxybenzoic acid, 3 — Cyclohexyl 4- 4-hydroxybenzoic acid, 3, 5 — dimethyl 4- 4-hydroxybenzoic acid, salicylic acid, 3 — isopropyrisalicylic acid, 3-ter L— Butylsalicylic acid, 3—Benzylsalicylic acid, 3— (a-Methylbenzyl) salicylic acid, 3—Chlor-5- (Hismethylbenzyl) salicylic acid, 3, 5—Di—Ler butyl salicylic acid, 3-phenyl-1-yl 5 -— (, -dimethylbenzyl) salicylic acid, 3,5—Di-methyl benzylbenzenesalicylic acid Ruponic acid, and these funinolic compounds, Happo-Ren Ruponic acid and, for example, lead, magnesium Aluminum chloride, calcium, titanium emission, manganese, tin, organic acidic substances such as salts of polyvalent metals such as nickel and the like.

The ffl ratio of the salty colorless dye and the acidic substance in the heat-sensitive recording layer is appropriately selected according to the type of the basic colorless dye and the acidic substance to be used. Generally 1 to 5 parts by weight, preferably 1 part by weight of basic colorless dye, preferably Or ii About 0 parts by weight of acidic substances are used.

In preparing a coating solution containing these substances, water is generally used as a dispersion medium, and a basic colorless dye and an acid are mixed with a mill such as a ball mill, an attritor, and a sand grinder. The substance is dispersed together or separately and prepared as a coating solution. In this case, it is desirable that the dispersed particles are as small as possible, and more specifically, it is desirable that the particles be dispersed to particles of 2 m or less.

In such a coating solution, starches, hide mouth resilose, methylcellulose, carboxymethylcellulose, gelatin, casein, arabic gum, polyvinyl alcohol, disobutylene are used as adhesives. · Maleic anhydride copolymer salt, styrene 'Maleic anhydride copolymer salt, polyethylene · Ataryl acid copolymer salt, styrene • Ataryl acid copolymer salt, styrene' butadiene The copolymer (d) or the like is used in an amount of about 10 to 40% by weight, or about 15 to 0 to 0% by weight of the total solid.

Furthermore, an assistant for each electrode can be added to the coating solution. For example, sodium octyl sulfo succinate, sodium dodecyl benzene sulfonate, Dispersants such as uryl alcohol ester sodium salt, alginate, fatty acid metal salt, etc., UV absorbers such as benzofuninone, triazole etc., other defoaming agents, fluorescent dyes, coloring Dyes and the like.

Also, if necessary, lead sulphate phosphate, calcium sulphate sulphate, polyethylene wax, phenolic wax, "Raffinwax, esterwax etc. Lubricants, kaolin, clay, talc, carbonated calcium carbonate, calcined clay, titanium oxide, algae, inorganic pigments in the form of fine anhydrous silica, activated clay, etc., and inorganic pigments such as stearic acid Amide, methylene bisamide stearate, amide oleic acid Amide, fatty acid amide, calcium fatty acid amide, metabolic phenol, phenolic ester, "rabenzylbiphenyl, an ester derivative of hydroxysinaphthoic acid, dibenzyl terephthalate, A sensitizer such as tribenzylamine can also be added.

In the present invention, it is preferable to provide one barrier layer between the support and the heat-sensitive recording layer. This barrier layer reduces the influence of the surfactant contained in the support, and provides a thermosensitive recording paper having further improved discoloration during storage, background capri, and reliability against thermal head.

For example, a polymer layer having a film-forming property is used for one layer of the barrier, such as casein, polyvinyl alcohol, ammonium alginate, methyl acetate resin, hydroxyrese resin J-relose, and carboxyme. Tylcellulose, maleic anhydride copolymer, styrene ♦ Maleic anhydride copolymer, styrene / butadiene copolymer and the like. These high molecular compounds are usually used in emulsion form. The coating amount is generally 0.3 X m ^J to 5.0 g / m, preferably 0.5 g Z m 'to 2.0 g Z rrf ^. When the amount is less than 0.3 g Z nf, the effect of blocking the effect of the surfactant is reduced. On the other hand, when the amount is larger than 5.0 g Z rrf, the image quality tends to deteriorate.

Note that a protective layer may be provided on the heat-sensitive recording layer, if necessary. Further, an intermediate layer containing a pigment may be further provided on one of the barrier layers.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples.

Preparation of thermal paint

Black coloring basic dye 3 — (N-ethyl-N—isomil) R 6 1 — R 7 — R 2 R 1 Fluoran (S-205: Yamada Chemical Co., Ltd.) 9-fold: parts ♦ Polyvinyl alcohol 12% aqueous solution 15-fold. Parts • Polystyrene acrylate

2 ϋ% aqueous solution 0.7 layer:: part

• Water 30 times

Liquid · 2, 2 — Bis (4 years old)

H. 20 parts by weight

♦ Metadata unit 20 parts by weight

• Polyvinyl alcohol 12% aqueous solution 50 parts by weight

• Polystyrene ammonium ammonium

20% aqueous solution 3 parts by weight

.Water 62.3 parts by weight

Each of the solutions (1) and (2) was dispersed with a sand grinder so that the dispersed particles had an average particle size of 2 μm or less.

Solution C · Light carbonic acid calcium lime 2 5 parts by weight

• 40% aqueous solution of sodium polyacrylate 丄 parts by weight

24 parts by weight of water

Solution C was dispersed with a homomixer for i 0 minutes

54.7 parts by weight of the solution prepared as described above, 15.5.3 parts by weight of the solution B and 50 parts by weight of the solution C were mixed, and 30% of zinc stearate was dispersed in the obtained mixture. Rest 33.3 parts by weight and polyvinyl alcohol 12% water solution 0 () parts by weight and water 1'3 () parts by weight were added to obtain a heat-sensitive paint. Example JL

The above heat-sensitive paint was applied to 50 g / m 'base paper of rice tsubo with a residual amount of 240 ppm of anionic surfactant (sodium alkylbenzene sulfonate) at a blending ratio of waste paper of 40%. , the coating amount after drying 5 g Z m ^s become O and urchin coated, dried and subjected to further calendars first processing, base of the recording surface Hot-Thermal recording paper with a smoothness of 6 6 seconds was obtained.

Example 2

Same as Example 1 from 50 gZm'-base paper with 50% of non-ionic surfactant (polyoxyethylene alkyl phenyl ether) remaining at a blending ratio of 50% waste paper Example 3 obtained thermal recording paper

Thermal recording was performed in the same manner as in Example 1 from a base paper of 50 gZn of 50 g / m2 of non-woven surfactant (polyoxyethylene alkylphenyl ether) with a blending ratio of waste paper of 60% and a nonionic surfactant (polyoxyethylene alkylphenyl ether) of 501 pm. Example 4 where paper was obtained

Same as Example 1 from 50 gZrf base paper with 50% rice tsubo containing 5% by weight of waste paper and a residual amount of cation-based surfactant (alkyltrimethylammonium chloride) of 7% () ppm Thus, a thermosensitive recording paper was obtained. Example 5

From the base paper of 50 gZrrf of rice tsubo with a blending ratio of waste paper of 50% and a residual amount of an anionic surfactant (sodium alkyl benzenesulfonate) of 950 pm, In the same manner, a thermosensitive recording paper was obtained. Comparative Example 1

In blending ratio of waste paper is 50%, carried out from the base paper of basis weight 5 0 g / m ^a residual amount of Anio emissions based field而活agent (alkyl downy Nzensuruhon Sanna Application Benefits um) is 1 2 0 0 ppm Thermal recording paper was obtained in the same manner as in Example 1. Comparative Example 2

A 50 g Znn base paper with a nonwoven surfactant (polyethylene alkylalkyl unyl ether) content of 50% and a nonionic surfactant (polyethylene alkylene alkyl ether) of 140 ppm was prepared in the same manner as in Example II. To obtain thermal recording paper n Comparative example 3

In blending ratio of waste paper is 50%, carried out from the base paper of mosquito thio emissions based surfactant (Arukiruto re main Chirua Nmoniu Solid La i de) residual amount of 1 5 0 Y basis weight 5 0 g / m ^s of ppm Thermal recording paper was obtained in the same manner as in Example 1. Comparative Example 4

Starting from 5 OgZn base paper with a blending ratio of waste paper of 4% and a nonionic surfactant (polyethylene alkylene alkyl ether) remaining at 150 ppm. Thermal recording paper was obtained in the same manner as in Example 1.

Example 6

A thermosensitive recording paper was obtained in the same manner as in Example 4, except that polyvinyl alcohol was applied on the base paper so as to give 1 g Zrrf.

Example 7

A thermosensitive recording paper was obtained in the same manner as in Example 5, except that polyvinyl alcohol was applied on the base paper so as to be 1 g Zn.

Example 8

A thermosensitive recording paper was obtained in the same manner as in Example 7, except that the coating amount of polyvinyl alcohol was 2 g Z rn ^s .

Next, the following tests were performed on the thermal recording papers obtained in Examples 1 to 8 and Comparative Examples 1 to 4, and the results are shown in Table 1.

) Preservation

Using a thermal facsimile FF 6 21 C [manufactured by Todo-tsudo], print a test pattern and record the background and the printed part with a Macbeth densitometer RD-5 14 11] And measured. Further, the sample printed with F'F621C was used in the following storage stability test.

a) Moisture resistance

Store for 24 hours under the high humidity condition of 40 "C-90% R II, and The background portion and the printed portion were measured using Macbeth RD-514. b) Heat resistance

6ϋI: Stored under high-temperature drying conditions of 24 hours, and measured the density of the background portion and the printed portion after storage using a Macbeth densitometer RD-514 with ffl. (2) Head destruction test

Using a commercially available Kyocera Samaru Head (KJT-216--8 MGF1), wrap the thermosensitive recording paper around the platen and secure the platen roll and the samlal head (0.15 kgf SQV-85% R II Under environmental conditions and stored for 20 hours with the voltage applied to the head, solid printing was performed and the dot missing rate was examined.

Evaluation 抜け Dot missing rate is 5% or less

△ Dot missing rate is 5 to 10% or less

X dot missing rate is 10% or more

Wastepaper / Storage Test Head Surfactant

Moisture resistance Heat resistance Destruction

(%) Type Remaining amount Background area Printing area Background area Printing area Background area Printing area Test Example 1 40 Anion 240 0.06 1,25 0.08 K20 0.13 1.26 〇

2 50 Nonionic 430 0.06 1.25 0.08 1.21 0.14 1.27 〇

3 60 Nonionic 510 0.06 1.26 0.08 1.22 0.13 1.25 〇

4 50 Cationic 700 0.06 1.25 0.12 1.23 0.14 1.22 〇

5 50 anion type 950 0.06 1.26 0.06 1.15 0.12 1.23 比較 Comparative example 1 50 anion type 1200 0.06 1.26 0.06 1.04 0.12 1.24 X

2 50 Nonion 1400 0.06 1.25 0.06 0.81 0.23 0.92 Δ

3 50 Cationic 1500 0.06 1.25 0.15 1.19 0.24 1.21 X

4 40 Non-ion type 1500 0.06 1.25 0.06 0.79 0.21 0.89 △ Example 6 50 Cationic type 700 0.06 1.25 0.08 1.22 0.13 1.21 〇

7 50 Ayuon 950 0.06 1.23 0.06 1.19 0.11 1.20 20

8 50 Anionic 950 0.06 1.22 0.06 1.20 0.12 1.23 Anionic surfactant Alkylbenzenesulfonate sodium

Non-ion type "polyethylene alkyl alkyl ether"

才系レノノノノレノノノノレノ

As can be seen from Table 1, the residual amount of the surfactant is set to 100 m or less even though the waste paper is blended. Highly reliable thermal recording paper for thermal heads can be obtained. Further, it can be seen that the performance is further improved by providing one barrier layer between the support and the thermal recording paper.

Claims

The scope of the claims

1. In a heat-sensitive recording paper provided with a heat-sensitive recording layer on a support, which contains a salt-based colorless dye and an acidic substance that causes the basic colorless dye to develop color when heated, wherein the support contains waste paper. A thermosensitive recording paper, characterized in that the content of residual surfactant contained in the support is 100 ppm or less.

2. The thermal recording paper according to claim 1, wherein the content of the waste paper is 60% or less.

3. The thermosensitive recording paper according to claim 1, wherein the content of the surfactant is 800 ppm or less.

4. The thermosensitive recording paper according to claim 1, wherein a barrier layer is provided between the support and the thermosensitive recording layer.

5. The above layers are made of casein, polyvinyl alcohol, ammonium arginate, methylcell σ-s, hydrocyanic acid, etc.

I5 It is composed of a polymer compound selected from the group consisting of lowose, carboxymethylcellulose, maleic anhydride copolymer, styrene / maleic anhydride copolymer, and styrene / butadiene copolymer. The thermal recording paper according to claim 4.

6. The barrier layer of the coating: is 0. 3 to 5. is 0 g Z m ² according

2 熱 Thermal recording paper according to range 15.

7. The heat-sensitive recording paper according to claim 6, wherein the application of the barrier layer is from 0.5 to 2. () g Z rrf.