JPS6164485A - Pressure-sensitive recording paper - Google Patents

Abstract

PURPOSE:To form pressure-sensitive recording paper capable of easily forming a stable image excellent in durability, by coating a support with a microcapsule prepared by dispersing fine pigment particles throughout a hydrophobic solution of an adhesive component to encapsulate the same along with said adhesive component. CONSTITUTION:This invention is constituted so that an adhesive component encapsulated in a microcapsule along with fine pigment particles strongly fixes the fine pigment particles transferred from the microcapsule to thin paper being a support by the compressive destruction of said microcapsule. The fine pigment is especially important and the fine particle size thereof is pref. 1,000Angstrom or less, especially pref., 500Angstrom or less. It is proper to set the ratio of the adhesive component, which is necessary for stably fixing the fine pigment particles to the support, and a solvent to 8/2-5/5.

Description

[Detailed Description of the Invention] The present invention relates to a pressure-sensitive recording paper, and more specifically, to a pressure-sensitive recording paper that has excellent image durability by using microcapsules containing fine pigment particles together with an adhesive component. Regarding pressure-sensitive recording paper.

Juren M Co., Ltd. Conventionally, as the most common pressure-sensitive recording paper, there is a paper called carbonless paper that uses a coloring material produced by the reaction of a colorless dye and a color developer for image formation.

This kind of pressure-sensitive recording paper is made by micro-capsulating a colorless dye solution dissolved in a solvent and applying it to the back side of a support (paper) (this is called a CB receipt), which reacts with the colorless dye to develop color. It is composed of a sheet (referred to as a CF receipt) in which a color developer is coated on the surface of a support (paper) to form a body. Furthermore, if a large number of copies are required using this method, a sheet (called a CFB sheet) coated with a color developer on the surface of the support (paper) and microcapsules of a colorless dye solution on the back side is used. added,
It is composed of a combination of three types of sheets. (Tokuko Showa 4
9-2124, [15P-3, 836, 383) Pressure-sensitive recording paper based on this method has excellent performance for copying and recording, and is widely used.

On the other hand, however, the composition is complicated because it requires a variety of chemicals, and furthermore, it uses a coloring body that uses chemical reactions, so chemicals such as water are used.

It is easy to change due to pressure-sensitive recording paper, and great care is required to preserve the pressure-sensitive recording paper or preserve the colored image. It disappears. A similar phenomenon occurs with light, further complicating its handling.

Furthermore, carbon paper is conventionally known as another type of pressure-sensitive recording paper. This type of pressure-sensitive recording paper has pigments weakly fixed with wax on the back side of the support (paper).
Images are formed by pressure-sensitive transfer onto other papers that do not use special chemicals.

This type of pressure-sensitive recording paper has the advantage of being able to form images on plain paper (paper that does not use special chemicals), but because the fixation of the pigment to the support is extremely weak, , easy to cause contamination during storage or handling. Also,
Excessive caution is required when handling as it adheres to the hands and clothes of the person handling it. Furthermore, the transferred image is essentially only weakly fixed to the surface of the support, and surface friction after printing contaminates the periphery of the image1, which not only spoils the aesthetic appearance but also causes misreading.

In addition, in pressure-sensitive recording paper made by microcapsulating a colored oil-soluble dye solution and coating it on the back side of the support, as seen in JP-A No. 57-98390, the light resistance of the image is poor. Long (Unable to obtain stable images.

1. As mentioned above, the pressure-sensitive recording paper obtained by the prior art does not have sufficient durability or sharpness of the recorded image. The situation is difficult to describe as performance. On the other hand, these conventional pressure-sensitive recording papers also have problems with stability before color development. For example, in the case of carbonless paper, light causes color development on the entire paper surface, and carbon In the case of paper, contamination of the paper occurs due to heat. For this reason, great care has been required in handling the recording paper before color development, storage, and handling of the recording paper after forming a recorded image.

That is, although it is strongly desired to provide pressure-sensitive recording paper that is easy to store and handle and has good stability of recorded images, this objective has not yet been achieved.

As a result of intensive research to solve the above-mentioned problems with pressure-sensitive recording paper, the present inventors have found that by using minute pigment particles that are microencapsulated with an adhesive component, the durability of recorded images can be improved. Moreover, the present invention was successfully achieved by successfully obtaining a pressure-sensitive recording paper that was not complicated to handle.

The structural feature of the present invention is that fine pigment particles are dispersed in a hydrophobic solution of an adhesive component and microcapsules containing the fine particles are coated on a support (in this case, paper). Specifically, in the present invention, the adhesive component encapsulated in microcapsules together with fine pigment particles firmly transfers the fine pigment particles from inside the capsule onto the lower paper as a support by pressure-sensitive destruction of the microcapsules. It is designed to be fixed.

. Among the materials used to bring out the effects of the present invention,
Micropigments are of particular importance, with microparticles having a size of 10
The thickness is preferably 0.00 angstroms or less, particularly preferably 500 angstroms or less.

If it exceeds 1000 angstroms, the transfer from the microcapsules will be poor and sufficient image density cannot be obtained. Furthermore, it is necessary that the b1 degree of the micropigment particles to be microencapsulated is 25% or less.

If it exceeds 25%, sufficient metastasis cannot be obtained.

On the other hand, the adhesive component may be any adhesive component that can be dissolved in a hydrophobic solvent and capable of adhering and holding the pigment fine particles to the support after the capsules are broken (although not particularly limited, the adhesive component is effective for the present invention). Specific examples include polystyrene, polymethacrylate, polymethylmethacrylate, low-molecular polyethylene, ethyl cellulose, natural rubber, chloroprene rubber, etc.In addition, in order to stably fix micropigment particles to a support, The appropriate ratio of the required adhesive component to the solvent is 872 to 515.

Next, as hydrophobic liquids that can be used in the present invention, aromatic solvents such as alkylbenzenes such as toluene, xylene, ethylbenzene, mesitylene, cymene, and cumene; methylnaphthalene, ethylnaphthalene, dimethylnaphthalene, Alkylnaphthalenes such as diethylnaphthalene, isopropylnaphthalene, diisopropylnaphthalene, methylisopropylnaphthalene, methylbutylnaphthalene, amylnaphthalene; and alkyls such as methylbiphenyl, dimethylbiphenyl, ethylbiphenyl, diethylbiphenyl, isopropylbiphenyl, diisopropylbiphenyl, butylbiphenyl, etc. Biphenyl M wo'III can be shown. Furthermore, in addition to these, hydrogenated aromatics such as cyclohexane, tetralin, and decalin; and esters such as diethyl phthalate, diisopropyl phthalate, dibutyl phthalate, dioctyl phthalate, diethyl sebacate, dibutyl sebacate, diethyl adipate, and ethyl benzoate are also used. It is possible. These solvents mentioned above are suitable for use alone or as a mixture of two or more, but there is no problem in using other solvents in combination for controlling viscosity or for other purposes, and the effect of the present invention will still be achieved. It's not something you lose.

Microcapsules having the above-mentioned pigment fine particles, adhesive component, and their solvent as core materials can be produced by a known method. The membrane material constituting the microcapsules is not particularly limited due to the transferability of the micropigment particles, but polyurethane microcapsules and amino resin microcapsules are recommended from the viewpoint of storage stability before use. Most preferred.

As mentioned above, the pressure-sensitive recording paper according to the present invention is made by coating a support such as paper with microcapsules containing fine pigment particles and an adhesive component, so it is difficult to store and handle. It is easy to use, and when pressure such as pen pressure is applied during use, the microcapsules are destroyed, and at that time, the pigment particles transferred from the capsules to the support are firmly fixed by the adhesive component. Become. Therefore, according to the present invention, stable images with excellent durability can be easily obtained.

EXAMPLES The effects of the present invention will be explained in more detail below with reference to Examples and Comparative Examples.

1. To 670 g of diisopropyl naphthalene, 85 g of carbon black (manufactured by Mitsubishi Kasei Co., Ltd. - #33/280 angstrom), polystyrene (manufactured by Dainippon Ink Chemical Co., Ltd.)
Elastyrene) 50g-t-mixed and dissolved in water 1790g
g, and 26 g of 6% Neoperex aqueous solution (sodium alkylbenzenesulfonate aqueous solution, manufactured by Kao Atlas Co., Ltd.)
and 89 g of Neelamine P 1500 aqueous solution (Neelamine Kogyo!! Li) and 89 g of 10% triethanolamine were added, and this solution was diluted with 10% citric acid aqueous solution.
The mixture was adjusted to H4.8 and dispersed using an emulsifying machine. 700 g of this dispersion was kept at 30°C while stirring, and 700 g of melamine 70
Formalin adjusted to pH 8.5 with g and 2% NaOH aqueous solution (same as below 37% formaldehyde aqueous solution) 29
0g and 360g of distilled water were mixed and reacted at 50°C for 60 minutes, then 51g of MF prepolymer and 280g of formalin adjusted to pH 8.5 with triethanolamine and urea 1)
5g were mixed and reacted at 70°C for 1 hour, 26g of UF polymer was added, and 1 volume of 10% citric acid was added to adjust the pH to 3.0.The reaction was continued with stirring, and the adhesive was removed manually. - Microcapsules of bomb black dispersion were obtained. Polyvinyl alcohol (manufactured by Kurashiki Rayon Co., Ltd. - Kuraray Bobal 105) was added to the slurry of the obtained microcapsules.
) Add 5% and add 3g/sqm to 50g/sqm high-quality paper
After coating and drying, a pressure-sensitive recording paper was obtained.

Xylene and methylnaphthalene (50/50wt/
A pressure-sensitive recording paper was obtained in the same manner as in Example 1 except that the mixture wt) was used.

Back 1 Plate 1 Pressure-sensitive recording paper was obtained in the same manner as in Example 1, except that ethyl cellulose (manufactured by Vercules/N-4) was used in place of polystyrene in Example 1.

1. Carbon black microcapsules prepared in the same manner as in Example 1 except that carbon black (#5B/850 angstroms manufactured by Mitsubishi Kasei Corporation) was used instead of the carbon black in Example 1 were applied and pressure sensitive was obtained. I got the recording paper.

Comparison plate 1 Carbon powder-containing microcapsules were prepared in the same manner as in Example 1 except that carbon powder of 0.15 microns was obtained by classifying a crushed product of our company's petroleum pitch instead of the carbon black in Example 1. This was prepared and coated in the same manner as in Example 1 to obtain coated paper.

Next, the results of investigating the performance of each of these pressure-sensitive recording papers are shown in the table below.

For reference, the performance of conventional carbon paper is also shown in the table.

Procedure ■↑JE book October 16, 1980

Claims (3)

[Claims] (1) Pressure-sensitive recording paper made by coating a support with microcapsules containing fine pigment particles and an adhesive component. (2) The pressure-sensitive recording paper according to claim (1), wherein the size of the pigment particles is 500 angstroms or less. (3) The ratio of the adhesive component to the hydrophobic liquid in the microcapsule core material is from 8/2 to 5/5.
Pressure-sensitive recording paper described in section 1).