JP3129597B2 - Pressure-sensitive recording sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive recording sheet, and more particularly to a pressure-sensitive recording sheet for reading a bar code.

[0002]

2. Description of the Related Art A pressure-sensitive recording sheet is prepared by dissolving an electron-donating organic color-forming agent or the like in oil, and coating a color-forming agent microcapsule composition mainly composed of microcapsules in which oil droplets are encapsulated on one surface of a substrate. On the coated upper paper, one side of the base material is coated with an electron-accepting developer composition that forms a color when it comes into contact with the above color former, and on the other side, a medium paper or base material coated with the color former microcapsule composition Paper with a developer applied to one side of
Self-coloring paper coated with a color former microcapsule composition and a color developer composition on the same surface of the substrate, and partially printed with a color former microcapsule composition or a color developer composition as ink on a part of the substrate And others. These pressure-sensitive recording sheets are combined so as to obtain color, but a common combination is a copy set of upper and lower sheets, or a large number of copy sets with middle sheets between upper and lower sheets. It is. The combination of pressure-sensitive recording sheets is used for various slips such as sales slips and delivery slips, or contracts, since many copies can be obtained simultaneously by pressure.

On the other hand, in recent years, as a part of labor saving, a method has been proposed in which necessary information is added to slips using a barcode, the barcode is read by a barcode reader, and the information is automatically input to a computer. It is being actively performed. Even in slips formed by a combination of pressure-sensitive recording sheets, the bar code is printed by a dot impact printer, and a color bar code image is input by a bar code reader.

[0004]

However, when a known pressure-sensitive copying sheet used in a bar code reader is used, the printed bar code becomes thicker or has insufficient sharpness. There is a problem that the rate is low, and this tendency is particularly strong in a copied bar code.

[0005]

The inventors of the present invention have conducted various studies to solve these problems, and as a result, have used a synthetic paper made of polyester as a base material and having a thickness of 5%.
It has been found that the use of a pressure-sensitive recording sheet having an opacity of not more than 0 μm and an opacity of not less than 70% significantly improves the barcode reading rate.

That is, a synthetic paper made of polyester is used as a base material, and a microcapsule composition or a color developer composition is applied to the front or back surface thereof, and a thickness of 50% is applied.
By using a pressure-sensitive recording sheet having a thickness of not more than μm and an opacity of not less than 70%, the resolution and sharpness of a barcode printed by a dot impact printer are improved, and the transferability (copyability) is also improved. Therefore, for example, when upper paper based on synthetic paper made of polyester is combined with middle paper based on ordinary paper and lower paper, a bar copied on the second middle paper or lower paper is used. Since a bar code image with a small thickness of code printing and improved sharpness of a uniform thickness is obtained, the reading rate is improved.

Further, it is necessary that the opacity of a pressure-sensitive recording sheet based on synthetic paper made of polyester be 70% or more. Due to the influence, the reading rate of the barcode on the pressure-sensitive recording sheet decreases, and the object of the present invention is not achieved.

[0008] The pressure-sensitive recording sheet of the present invention is prepared by applying the microcapsule composition or the developer composition on the substrate separately or on the same surface of the substrate separately and drying. These compositions are prepared in the same manner as those used for known pressure-sensitive recording sheets. That is, the microcapsule composition is obtained by microencapsulating an electron-donating color former dissolved in oil and mixing it with a low-pressure destruction inhibitor, a binder, and the like. The developer composition comprises a developer and a binder. And the like, and is usually a water-dispersed composition. Coating of these compositions is
This is done by a charter. As the coater, an air knife coater, blade coater, curtain coater, rod coater, roll coater or the like is used. Since the composition of the present invention is suitably handled as an aqueous composition, drying after application is preferably performed by heating and drying. If the heat resistance of the substrate is insufficient, the substrate undergoes elongation due to heat and tension when passing through the drying zone, and coating cannot be performed. In the present invention using a polyester-based synthetic paper as a base material, the polyester-based synthetic paper has good heat resistance and can withstand heat-drying of an aqueous composition, so that it can be coated without any problem with a coater.

[0009] The polyester synthetic paper of the present invention enhances the opacity by filling a filler inside the polyester film or forming voids (voids) inside the polyester film. By applying a coating containing a molecule or a thermoplastic aqueous emulsion as a main component alone or in combination, or by applying a mixture of white pigments to these to impart aqueous ink receptivity and writability. It can be used like paper.

The electron-donating color-forming agent that can be used in the present invention has a color-forming portion formed by reaction with a color developer.
It is necessary to use a material having a relatively large absorption in a wavelength region of 0 to 720 nm, and any color-forming portion having an absorption in this region may be used.

Specifically, the following compounds can be exemplified. 3,3-bis [2- (4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethynyl] 4,5,6,7-tetrachlorophthalide 3,3-bis [2-2-bis ( 4-dimethylaminophenyl) ethynyl] 4,5,6,7-tetrachlorophthalide 3,3-bis [2-2-bis (4-dimethylaminophenyl) ethynyl] -5-pyrrolidinophthalide 3, 3-bis [2-2-bis (4-dimethylaminophenyl) ethynyl] -5-azaphthalide 3,3-bis [2- (p-methoxyphenyl) -2- (p-pyrrolidinophenyl) ethynyl] 4, 5,6,7-tetrachlorophthalide 3,3-bis [2- (p-methylphenyl) -2- (p-pyrrolidinophenyl) ethynyl] 4,5,6,7-tetrachlorophthalide 3, 3-bis [2- (p-methoxyphenyl) -2- (p-dimethylaminophenyl) ethynyl] 4,5,6,7-tetrachlorophthalide 6 '-[{4- (4-anilino) anilino} Anilino] -2'-chloro-3'-methylspiro [phthalide-3,9- Santen] 3- (Np-tolyl -N- ethylamino)-7-(N-phenyl--N-
Methyl) fluoran 6 '-{4- (4-anilino) anilino}
-2'-Phenylamino-3'-methylspiro [phthalide-
3,9-Xanthen] 6'-diethylamino-2- {4- (4-anilino) anilino}
-2'-phenylamino-3'-methylspiro [phthalide-3,
9-Xanthen] 3-3-bis (4'-dimethylamino-2-methoxyphenyl)
-4-azaphthalide, 3-3 bis (4'-diethylamino-2-
Ethoxyphenyl) -4-azaphthalide 3,6-di (N-dimethylamino) -fluorene-9-spiro
-3 '-(6'-dimethylamino) phthalide 3-diethylamino [a] (2,2-dimethyl-4-methyl)-
Pyridino-fluoran 3- (Np-tolyl-N-ethylamino)-(1'-N-ethyl-2 '
2'4'-trimethyl-pyridyl)-[a] -fluoran

Further, the following specific examples can be given as conventional pressure-sensitive dyes known in the field of pressure-sensitive copying paper which can be used in combination therewith. 3,3-bis- (P-dimethylaminophenyl) -6-dimethylaminophthalide 3,3-bis- (p-diethylaminophenyl) -6-dimethylaminophthalide 3,3-bis (2-methyl-1 -Octyl-3-indolyl) phthalide 3- (P-dimethylaminophenyl) -3- (1,2-dimethylindole-3-yne) phthalide 3,3-bis (1,2-dimethylindole-3-yne) Triarylmethane dyes such as -5-dimethylaminophthalide 3,3-bis- (p-diethylaminophenyl) -6-n-propylaminophthalide Thiazine dyes such as benzoyl leucomethylene blue and p-nitrobenzoyl leucomethylene blue Spiro dyes such as 1,3,3-trimethyl-6-nitro-indolino-benzospiropyran 3-methyl-spiro-dinaphthopyran 3-phenyl-spiro-dinaphthopyran 3-propyl-spiro-dinaphthopyran 3-diethylamino-6-methyl- 7- diethyla Rinofuruoran 3-diethylamino-6-methyl-7-anilinofluoran 3-dibutylamino-6-methyl-7-anilinofluoran 3- (N- ethyl--N--isopentylamino) -6-methyl-7-
Anilinofluoran 3- (N-cyclohexyl-N-methylamino) -6-methyl-7
-Anilinofluoran 3-diethylamino-7- (m-trifluoromethylanilino)
Fluoran 3-diethylamino-7- (o-fluoroanilino) fluoran 3-di-n-butylamino-7- (o-fluoroanilino) fluoran 3-diethylamino-7-dibenzylaminofluoran 3-diethylamino-5 -Fluoran dyes such as methyl-7-dibenzylaminofluoran

When these electron-donating color formers are encapsulated, they are usually dissolved in oil (hydrophobic medium) and used as a core substance. Examples of the hydrophobic medium include the following substances which are known in the field of pressure-sensitive copying paper. Phenylxylylethane, phenylxylylethane, phenylethylphenylethane, diarylalkanes such as phenylbutylphenylmethane, alkylnaphthalenes such as monoisopropylnaphthalene and dinoisopropylnaphthalene, isopropylbiphenyl, butylbiphenyl and partially hydrogenated terphenyl, and the like. A hydrophobic medium containing as a main component.

The microcapsules used in the present invention can be prepared by a conventionally known coacervation method (for example, US Pat. No. 280045).
7, 2800458, etc.), an interfacial polymerization method (for example, a method described in JP-A-57-140638 and 60-227828), an in-situ polymerization method (for example, Japanese Patent Publication No. 51-9)
No. 079, JP-A-53-84881).

The above-mentioned electron-donating color former which has a large absorption in the wavelength range of 620 to 720 nm by reacting with the color developer,
Usually, about 2 to 10% by weight is dissolved in the above-mentioned hydrophobic medium, and when the visual density is required to be improved, a conventional electron-donating color former is also dissolved together and microencapsulated by the above-mentioned encapsulation method. The microcapsule slurry thus obtained is applied on a support with a suitable amount of a binder together with a low-capacity destruction inhibitor for microcapsules, such as raw starch, in an amount of about 1 to 8 g / m ² according to a conventional method.

Examples of the binder used in this case include synthetic resin emulsions such as styrene-butadiene copolymer emulsion, polyacryl emulsion, acryl-styrene copolymer emulsion and polyester emulsion, polyvinyl alcohol, starch and cellulose derivatives. Water-soluble binders can be mentioned.

Examples of the color developing agent include acid clay, activated clay, natural solid acids such as attapulgite, zeolite and bentonite, metal salts of aromatic carboxylic acids, phenol formaldehyde resins and these metal salts, and carboxylated terpene phenol resins. And mixtures thereof as a main component.

The pressure-sensitive recording sheets according to the present invention, such as upper paper, middle paper, lower paper, and self-coloring paper, can form a pressure-sensitive copy set by themselves, or can be a conventional pressure-sensitive copy set. A pressure-sensitive copying sheet may be partially incorporated to form a pressure-sensitive copying set.

Hereinafter, the present invention will be described in detail with reference to examples. Since the effect of the present invention is most remarkable when the pressure-sensitive recording sheet of the present invention is an upper sheet, in the following examples, the case where the pressure-sensitive recording sheet of the present invention is an upper sheet was performed.

[0020]

【Example】

[Example 1] (Encapsulation) Acrylic acid-styrenesulfonic acid-ethyl acrylate copolymer (monomer ratio: 85: 8: 7, molecular weight: approx.
(240,000) 5% aqueous solution (180 parts) Dissolve urea (10 parts) resorcin (12 parts) and adjust to PH3.4 with 20% caustic soda to obtain hydrophilic liquid. Then, 5.0 parts of 3-3 bis (4'-diethylamino-2-ethoxyphenyl) -4-azaphthalide as a pressure-sensitive dye having an absorption in the wavelength region of 620 to 720 nm, and a normal pressure-sensitive dye for improving the visual density. 3-diethylamino-6-methyl-7
-A mixture of 3.0 parts of diethylanilinofluoran and 1 part of 3,3-bis (2-methyl-1-octyl-3-indolyl) phthalide, and 125 parts of a hydrophobic liquid dissolved in 117 parts of diisopropylnaphthalene are added. Was added with vigorous stirring to the obtained hydrophilic liquid to obtain an emulsion having an average particle size of 5.0 μm.
Next, 27 parts of a 37% formalin solution was added to the emulsion, and the mixture was heated to 55 ° C. while stirring and allowed to undergo an encapsulation reaction at this temperature for 3 hours. Adjusted to .5 and completed encapsulation.

(Preparation of Test Paper) A microcapsule obtained by adding 20 parts of starch particles and 30 parts of a polyacryl emulsion to 150 parts of the microcapsule dispersion prepared above and adding water to a concentration of 25%. The capsule composition was used as a paint. The base material is a 25 μm thick coated on polyester with a mixture of water-soluble polymer and polyester emulsion as the main component.
Using synthetic paper (Crisper G2311 manufactured by Toyobo Co., Ltd.)
The above-mentioned microcapsule coating material was applied at 5 g / m ² on the back surface opposite to the application surface by an air knife coater and dried with hot air to obtain a pressure-sensitive recording sheet of the upper paper. At this time, the upper sheet had a thickness of 33 μm and an opacity of 77%. Opacity is
The average value of the opacity measured by the method A of JIS P 8138 on the front and back surfaces of the upper paper was defined as the opacity of the present invention.

(Measurement of Reading Rate) The capsule surface of the test sheet prepared above and a commercially available lower paper (NW50 manufactured by Nippon Paper Industries Co., Ltd.)
BA), print a series of 100 barcodes with a dot impact printer (F9680M2, manufactured by Fujitsu Ltd.), and use a barcode verifier (RJS, INC, inspector II model 200) one day later to print on the top paper. The barcode reading rate was measured for the surface (dot impact surface) and the surface of the lower sheet (copying surface). The reading rate was obtained by measuring the number of barcode pairs that were correctly read in one scan for the upper sheet and the lower sheet, and expressed as a percentage (%) of the total number (100 pairs).

Example 2 As a base material, a 38 μm thick synthetic paper (Crisper manufactured by Toyobo Co., Ltd.) obtained by applying a paint containing a white pigment and a binder as main components on polyester to give ink receptivity. G7911) was used in the same manner as in Example 1 to obtain an upper pressure-sensitive recording sheet. The thickness of the upper sheet was 49μ and the opacity was 79%.

Example 3 As an electron-donating color former, 62
6.0 parts of 3-3 bis (2-4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethynyl-4,5,6,7-tetrachlorophthalide having an absorption in a wavelength range of 0 to 720 nm; Microcapsules and upper paper were prepared in the same manner as in Example 1 except that 3.0 parts of 3-diethylamino-6-methyl-7-diethylanilinofluoran, which is a usual electron-donating color developing agent, was used to improve the visual density. Was obtained. The thickness of the upper sheet was 32 μm, and the opacity was 77%.

Example 4 The same microcapsules as in Example 3 were applied to a 33 μm thick synthetic paper substrate of the same material as in Example 1 by the method of Example 1, and A pressure recording sheet was obtained. The thickness of the paper is 45μm, and the opacity is
86%.

[Comparative Example 1] The same material 50 as in Example 1 having a thickness of 50
An upper pressure-sensitive recording sheet was obtained in the same manner as in Example 1 except that a synthetic paper substrate of μm was used. The top paper thickness is 55
μm, opacity was 90%.

Comparative Example 2 The thickness of 25 μm used in Example 1
Example 2 except that the synthetic paper base material (Crisper G2311 manufactured by Toyobo Co., Ltd.) was replaced by a 38 μm-thick polyester synthetic paper (Crispar H2311 manufactured by Toyobo Co., Ltd.) of the same material and low opacity. The same treatment as in No. 1. The thickness of the upper sheet was 44 μm, and the opacity was 60%.

Comparative Example 3 A microcapsule paint of Example 1 was coated with an air knife coater in the same manner as in Example 1 using synthetic paper made of polypropylene having a thickness of 30 μm as a base material. As a result, when passing through the drying zone, the substrate was stretched in the flow direction, so that tension could not be applied and coating could not be performed.

Table 1 shows the results of Examples and Comparative Examples.

[0030]

[Table 1]

[0031]

By using the pressure-sensitive recording sheet of the present invention, the bar code reading rate is improved.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-125422 (JP, A) JP-A-5-177925 (JP, A) JP-A-49-130742 (JP, A) JP-A-4- 212882 (JP, A) JP-B 54-28766 (JP, B2)

Claims (3)

(57) [Claims] 1. A microcapsule containing an electron-donating color developing agent and an electron-accepting color developing agent are respectively or simultaneously applied onto a substrate, and the electron-donating color forming agent and the electron-accepting color developing agent are applied under pressure. Wherein the base material is a synthetic paper made of a polyester film , and the thickness of the pressure-sensitive recording sheet using the synthetic paper is 50 μm or less, and the opacity is 70%. A pressure-sensitive recording sheet for reading barcodes, characterized in that: 2. The pressure-sensitive recording sheet according to claim 1, wherein the pressure-sensitive recording sheet is an upper paper on which microcapsules containing an electron-donating color former are coated on the back surface of a substrate. 3. An electron-donating color former having a wavelength of 620 to 720 nm.
3. A pressure-sensitive recording sheet according to claim 1, wherein the pressure-sensitive recording sheet has significant absorption.