JPH024568A - record sheet - Google Patents

Abstract

PURPOSE:To improve ink fixing property by sequentially laminating an ink receiving layer containing as a main ingredient acrylic resin having 20 deg.C or lower of glass transition temperature and a surface layer containing as a main ingredient curable silicone resin on a support. CONSTITUTION:An ink receiving layer containing as a main ingredient acrylic resin having 20 deg.C or lower of glass transition temperature is provided at least on a support made of plastic film, a sheet, a synthetic fiber sheet, etc., and a surface layer containing as a main ingredient curable silicone resin is laminated thereon to form a recording sheet. The acrylic resin for the receiving layer includes resin having -10 deg.C or lower of glass transition temperature, and particularly 2-ethylhexylmethacrylate resin is proper. Concrete examples of the silicone resin include ultraviolet ray curable silicone resin, condensation reaction silicone resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a recording sheet suitable for a wire dot printer using an ink ribbon, and more particularly to a recording sheet with excellent ink receptivity.

<Prior Art> Wire dot printers are one of the most common printers available today, and are widely used. The ink used in this printer is made by dispersing coloring materials such as dyes and pigments using a wax-based substance as a binder, and when printed, the wax-based substance is driven into the unevenness of the surface of the recording paper and is fixed. It is something that forces you to do something.

However, in recent years, with the diversification of recording media, it has become desirable for wire dot printers to be able to print on special sheet-like materials different from conventional paper, such as various plastic films, synthetic fiber sheets, and metal-deposited sheets. However, these sheet-like materials have no or very little unevenness on the surface, so even if printing is done properly, the ink cannot be properly fixed, making it difficult to print with your fingertips. There was a problem in that the ink would fall off or be transferred to other objects even if rubbed.

In addition, in the case of conventionally used recording paper, the generation of paper dust cannot be suppressed due to the nature of the paper itself, and it is not suitable for use in environments where dust and dust are a problem, such as in a clean room. First, there is a demand for a recording sheet that does not generate paper dust or the like as an alternative to paper. In response to these demands, sheets such as plastic film solve the problem of paper dust, but as mentioned above, there is a problem with ink fixation, and there is a demand for a recording sheet that does not have any practical problems in environments such as clean rooms. has been done.

On the other hand, methods have been proposed to improve the ink fixation properties of plastic films such as those mentioned above (and to provide a surface layer containing a large number of pigment particles on the surface), but there are problems such as shedding of pigments and poor appearance, especially for overhead projectors. - There is a problem in that transparency is impaired when used for wire dot printers, and therefore, a film-type recording sheet of sufficiently satisfactory quality for use in wire dot printers has not yet been obtained.

<Problems to be Solved by the Invention> In view of the above circumstances, the present invention provides a recording sheet that has excellent ink fixing properties, does not generate dust such as paper powder, and is suitable for printing with a wire dot printer. be.

Means for Solving the Problems> The present invention provides an ink-receiving layer containing as a main component an acrylic resin having a glass transition temperature of 20° C. or less on at least one side of a support, and a curable silicone resin as a main component. This is a recording sheet characterized by sequentially laminating surface layers.

The ink-receiving layer constituting the recording sheet of the present invention is a part that receives ink from a recording means and fixes it during recording,
It contains as a main component an acrylic resin having a glass transition temperature (hereinafter referred to as Tg) of 20°C or less.

The acrylic resin with a Tg of 20'C or less is
Tg of homopolymers and copolymers of various monomers such as acrylic and methacrylic acids and esters, and their derivatives, or copolymers with other vinyl monomers, etc., is 20°C or less. belongs to. Even if the chemical composition is the same, the Tg of the resin varies depending on the structure of the polymer, the degree of polymerization and the distribution of the degree of polymerization, the aging conditions, and the measurement method, but the Tg in the present invention is the stable state after aging, which will be described later. It shows the Tg value measured by the measurement method. Examples of acrylic resins with a Tg of 20°C or lower include polymethyl acrylate (128°C,
Tg is shown in parentheses below), ethyl acrylate resin (-22℃), isopropyl acrylate resin (-5℃
), 2-hydroxyethyl acrylate resin (-15℃
), n-butyl methacrylate resin (20°C), n-amyl methacrylate resin (10°C), n-hexyl methacrylate resin (-5°C), n-octyl methacrylate resin (-20°C), n-tetradodecyl methacrylate Examples include, but are not limited to, resin (-9°C), 2-ethylhexyl methacrylate resin (-10°C), and 2-dimethylaminotyl methacrylate resin (19°C). The glass transition temperature in the present invention was measured using a compensated differential scanning calorimeter using alumina as a standard substance at a heating rate of 5°C/min. In curve 1, the temperature at intersection 2 on the extension line of each line between baseline 3 and endothermic peak was defined as the glass transition temperature.

The acrylic resin for the ink receiving layer has a Tg of 2 as described above.
A resin having a temperature of 0°C or lower is used, and a resin having a temperature of -10°C or lower is particularly suitable, and 2-ethylhexyl methacrylate resin is particularly suitable. In the ink receiving layer, the Tg
It is preferable that the acrylic resin having a temperature of 20° C. or less be contained in an amount of 30 to 100 M%.

The thickness of the ink-receiving layer is preferably about 2 to 10 μm; if it is less than 2 μm, sufficient ink fixing properties cannot be obtained;
Even with the above, commensurate effects cannot be obtained, and problems arise in terms of manufacturing, raw material costs, and the like.

The surface layer constituting the recording sheet of the present invention protects the ink-receiving layer and provides the recording sheet with good handling properties.
It imparts blocking resistance, is provided so that the head wire of a wire dot printer penetrates the surface layer during recording, and contains a curable silicone resin as a main component.

The curable silicone resin used as the resin for the surface layer can be cured by heating, UV irradiation, adding a curing agent and heating, or it can form a cured film at room temperature without using any of these methods. There are things. for example,
Examples include ultraviolet curing silicone resins, condensation reaction silicone resins, addition reaction silicone resins, peroxide curing reaction silicone resins, and silicone resins modified with alkyds, polyesters, epoxies, urethanes, acrylics, etc. be able to. Further, among these silicone resins, silicone resins having an antistatic function are particularly suitable for handling such as prevention of adhesion of dust and dirt due to static electricity and transportability. The silicone resin having an antistatic function includes, for example, a polysiloxane antistatic agent, and refers to a silicone resin whose surface resistivity after coating and drying is 101 IΩ/mouth or less. .

The surface layer contains 50% by weight of the above-mentioned curable silicone resin.
It is preferable to contain the above amount. Also, the thickness of the surface layer is approximately 2
It is preferably less than μ, and if it is more than 2 μ, good ink fixing properties cannot be obtained.

In the present invention, the support includes, for example, polyester such as polyethylene terephthalate, various acrylic and methacrylic polymers, polyvinyl chloride, polycarbonate, polyimide, acetate, cellophane, celluloid, and other plastic films or sheets, synthetic fiber sheets, metal Examples include vapor-deposited films, but the film is not limited to these (it may be selected as appropriate, taking into consideration the adhesion of the ink-receiving layer provided on the surface, depending on the purpose of recording and use).

The recording sheet of the present invention is composed of the support, the ink receiving layer and the surface layer as described above, and various additives may be added to these as necessary. For example, polyethylene oxide, silica, clay, talc, kaolin, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolite, alumina, zinc oxide, lithopone, Pigments such as satin white can be added, and additives such as dispersants, fluorescent dyes, antifoaming agents, lubricants, and low resistance agents can also be used to further improve sheet productivity, recording characteristics, etc. .

In order to produce the recording sheet of the present invention, a coating solution prepared by dissolving or dispersing the materials for forming each layer in water or an appropriate solvent is applied using a roll coating method, a blade coating method, a spray coating method, There are methods such as applying and drying by air knife coating method, rod bar coating method, etc., and methods of laminating a mixture of uniformly mixed materials for forming each layer by hot melt coating method, laminate coating method, etc. The ink-receiving layer and the surface layer may be sequentially laminated on the support by appropriately selecting one of these methods depending on the material used.

In the recording sheet of the present invention, an adhesive layer is provided on the back side of the support, that is, on the side where the ink receiving layer and the surface layer are not formed, using a commonly used adhesive,
Furthermore, if necessary, by laminating a release film or sheet with release properties on the adhesive layer, it can be used as an adhesive sheet or label that can be attached as desired. The area of use can be greatly expanded.

<Examples> Next, the present invention will be explained according to examples. In addition, all parts expressing the formulation indicate parts by weight.

Example 1 A coating liquid having the following composition was coated on one side of a polyethylene terephthalate film having a thickness of 100 μm using a Meyer bar coater and dried to form an ink-receiving layer. Note that the thickness of the ink receiving layer was 5 μm.

Next, a coating liquid having the following composition was applied to the surface of the ink-receiving layer using a gravure coater and dried to form a surface layer, thereby producing a recording sheet of the present invention. The thickness of the surface layer is 0.
It was set to 5μ.

Example 4 A recording sheet of the present invention was obtained in exactly the same manner as in Example 1, except that the coating liquid for the ink-receiving layer had the following composition.

Example 2 A recording sheet of the present invention was obtained in exactly the same manner as in Example Vfi11, except that the coating liquid for the surface layer had the following composition.

Example 3 A polysiloxane antistatic agent (manufactured by Toshiba Chemical Co., Ltd., Antistat C53900, solid content 5) was used as a coating liquid for the surface layer.
A recording sheet of the present invention was obtained in exactly the same manner as in Example 1 except that %) was used.

Example 5 A recording sheet of the present invention was obtained in the same manner as in Example 1 except that a 125 μm thick opalescent polyethylene terephthalate film was used as the support.

Example 6 A recording sheet of the present invention was obtained in exactly the same manner as in Example 1, except that a biaxially stretched polypropylene film having a thickness of 100 μm was used as the support.

Example 7 A recording sheet of the present invention was obtained in the same manner as in Example 1 except that the coating liquid for the surface layer had the following composition.

Example 8 A polysiloxane antistatic agent (manufactured by Nippon Colcoat Co., Ltd., Colcoat N103-X1 solid content: 16
A recording sheet of the present invention was obtained in exactly the same manner as in Example 1 except that %) was used.

Example 9 One J recording sheet of the present invention was prepared in exactly the same manner as in Example 1, except that the coating liquid for the ink-receiving layer had the following composition.

Comparative Example 2 A comparative recording sheet was prepared in exactly the same manner as in Example 1, except that the coating liquid for the surface layer had the following composition.

Comparative Example 3 A comparative recording sheet was prepared in exactly the same manner as in Example 1, except that the coating liquid for the surface layer had the following composition.

Comparative Example 1 A comparative recording sheet was prepared in exactly the same manner as in Example 1, except that the coating liquid for the ink-receiving layer had the following composition.

Comparative Example 4 A coating liquid having the following composition was coated on a polyethylene terephthalate film with a thickness of 100μ using a Meyer bar coater to a film thickness of 5μ.
A recording sheet for comparison was prepared by coating and drying to give the following properties.

Table 1 Regarding the recording sheets obtained in Examples 1 to 9 and Comparative Examples 1 to 4, wire dot printer (manufactured by NEC Corporation, P
C-PR201, ink ribbon is PC-PR-201-
A printing test was conducted using 01). The results are shown in the table-
1, it was confirmed that the recording sheet of the present invention exhibits extremely good ink retention ability when used in a wire dot printer that prints with an ink ribbon based on a wax-based substance.

[Margin below]

The evaluation method for each item in Table 1 is as follows.

(1) Ink receptivity: Visually evaluated good results as ◯, and poor results as ×.

(2) Ink retention: Rub the printed area with your fingertips immediately after printing. The ink does not come off at all and is in good condition. ◎, the ink is slightly ○ If the ink sticks to it, the ink will fall off. Items that would be affected were marked as ×.

<Effects of the Invention> Since the recording sheet of the present invention has excellent ink retention ability, it is possible to print on sheet-like materials other than paper such as plastic films, which were practically impossible to print with conventional wire dot printers. This has the advantage that the wire dot printer can be used in a very wide range of applications, including use in clean rooms, printing on sheets for overhead projectors, and many other applications.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing how to determine the glass transition temperature in the present invention. 1... Endothermic curve 2... Intersection point 3... Baseline

Claims (2)

[Claims] (1) An ink-receiving layer mainly composed of an acrylic resin with a glass transition temperature of 20°C or less and a surface layer mainly composed of a curable silicone resin are sequentially laminated on at least one side of the support. Record sheet. (2) The recording sheet according to claim 1, wherein the acrylic resin having a glass transition temperature of 20° C. or lower is 2-ethylhexyl methacrylate resin.