JPH07266550A - Ink jet recording method - Google Patents

Abstract

PURPOSE:To prevent impossibility of paper feed and its disturbance from occurring by a method wherein a coefficient of static friction between a recorded face of a material to be recorded and its rear face, a coefficient of static coefficient between the recorded face of the material to be recorded and its pad and a coefficient of static friction between the rear face and a paper feed roller are respectively specified within each range of a specific value. CONSTITUTION:A coefficient of static friction mu1 between a recorded face of a material to be recorded and its rear face is taken as 0.1<=mu1<=1.0, a coefficient of static friction mu2 between the recorded face of the material to be recorded and its pad is taken as 0.4<=mu2<=1.5, a coefficient of static friction mu3 between the rear face of the material to be recorded and a paper feed roller is taken as 1.0<=mu3<=3.0, and mu1<mu2<mu3 sre taken. When mu1 is less than 0.1, feed in layers occurs frequency. When mu1 is more than 1.0, a projected image with an OHP becomes dull. When mu1<1.0 and mu3<mu1, the material to be recorded is not separated and fed in layers. When mu2>1.5 and mu3<mu2, the paper feed roller slips. When mu3>=3.0, the paper feed roller can not be revolved, and paper can not be fed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method.

[0002]

2. Description of the Related Art Conventionally, as an ink for ink jet recording, an aqueous ink has been mainly used from the viewpoint of safety and recording characteristics, and a polyvalent alcohol has been added to prevent nozzle clogging and ejection stability. There is.

Recording materials used in this ink jet recording method include high-quality paper, bond paper, plain paper for writing, and coat paper and OHP sheet in which an ink receiving layer is applied to a base material. It is used.

In particular, when ink jet recording is performed on an OHP sheet, there are defects in ink fixability and dryness,
In addition to the problem that it is difficult to obtain a clear image, a blocking phenomenon occurs in which the front and back sides of the OHP sheet are in close contact with each other, and paper feeding disorder occurs in the recording device, which increases the reliability of the transportability of the recording device. There is also a problem in that

As a method for solving such a problem, Japanese Patent Laid-Open Nos. 60-239274 and 60-2 are available.
As disclosed in Japanese Patent No. 39275 and Japanese Patent Laid-Open No. 60-239276, at least one of the recording surface and the back surface has a concavo-convex shape so that good blocking properties and a clear image are compatible. A method by improving the recording material is mentioned.

[0006]

However, the above-mentioned conventional method has the following problems.

At present, as a method of automatically feeding a recording material for automatic continuous printing, as shown in FIG. 1, the recording material 11 is pressed against a paper feeding roller 13 by a hopper 12 to feed the material. A method of feeding the recording material to the paper feed roller 15 in a state where the recording material is separated one by one by the roller 13 and the pad 14 is being studied.

However, when continuous printing is performed by the above method using a conventional recording material, the recording material and the paper feeding roller slip and a paper feeding failure occurs, or the recording material There are many serious problems in transportation such as double feeding in which two or more sheets are fed by blocking each other under high temperature (30 ° C or more) and high humidity (80% or more). Further, if the unevenness is increased too much to solve the blocking, the frictional force between the pad and the recording material becomes larger than the force that the paper feeding roller conveys the recording material, and the paper feeding roller slips. Transport becomes impossible. Further, increasing the unevenness significantly reduces the light transmittance, and there is a problem that a clear projection image cannot be obtained with an OHP (overhead projector).

Therefore, the present invention is to solve such a problem, and an object of the present invention is to provide an ink jet recording method capable of continuously forming a clear and high quality image on a recording material. To provide.

[0010]

In the ink jet recording method of the present invention, a recording material having an ink receiving layer provided on a base material is brought into pressure contact with a paper feed roller with a back surface of the recording material by a hopper. A step of rotating the paper feed roller to separate the recording materials one by one by a paper feed roller and a pad, feeding the recording material, causing the liquid ink to fly to the recording material, and discharging the paper. In the continuous feeding process of the inkjet recording method, the coefficient of static friction between the recording surface and the back surface of the recording material is μ1, the coefficient of static friction between the recording surface of the recording material and the pad is μ2, and the back surface of the recording material. If the coefficient of static friction between the paper feed roller and the paper feed roller is μ3, then 0.1 ≦ μ1 ≦ 1.0 0.4 ≦ μ2 ≦ 1.5 1.0 ≦ μ3 ≦ 3.0 and μ1 <μ2 <Μ3.

Further, in the above recording method, the load applied by the hopper to the paper feed roller is 20 g or more and 300 g or more.
The load applied to the paper feed roller by the pad is set to 1 below.
It is characterized by being set to 00 g or more and 400 g or less.

[0012]

In the ink-jet recording method of the present invention, as shown in FIG. 2, the frictional force between the recording surface and the back surface of the recording material 21 is F1, and the friction between the pad 22 and the recording surface of the recording material is F1. When the force is F2 and the force for feeding the recording material in the paper feeding direction by the rotation of the paper feeding roller 23 is F3, the following relationship is established.

F1 <F3 ... Equation 1 F2 <F3 ... Equation 2 F1 <F2 ... Equation 3 Equation 1 expresses the force of the paper feed roller to feed the recording material in the paper feeding direction. By making it larger than the frictional force between the front surface and the rear surface, it is possible to prevent the paper feeding roller from slipping during the transportation to the pad and making it impossible to transport the recording material.

Formula 2 makes the force for feeding the recording material of the paper feed roller larger than the frictional force between the pad and the recording material, so that the paper feeding roller is fed during the conveyance to the paper feeding roller. It is possible to prevent the paper roller from slipping and making it impossible to convey the recording material.

Formula 3 makes the frictional force between the pad and the recording material larger than the frictional force between the recording surface and the back surface of the recording material, so that two or more recording materials are fed from the paper feed roller. When the paper is fed, the recording material can be separated and fed one by one to the paper feed roller.

From the above relationship, as an effect of the present invention, the recording material can be easily separated from each other by the paper feed roller and the pad, and can be conveyed without slipping by the paper feed roller. Therefore, during continuous automatic printing, it is possible to prevent the conveyance from being disabled or the paper feeding being disturbed.

[0017]

EXAMPLES The ink jet recording method of the present invention will be specifically described below.

The static friction coefficient characterizing the recording material used in the present invention is a value measured according to the method of ASTM-D-1984-63. Specifically, it is a value obtained from the following equation, by placing an object having a plane body on a plane, gradually inclining this plane, and determining from the angle at which the object begins to slide.

Μ = tan θ μ: Coefficient of static friction θ: Friction angle The coefficient of static friction between the recording surface and the back surface of the recording material is preferably 0.1 or more and 1.0 or less, more preferably 0.2 or more and 0.1.
It is preferably 6 or less. The coefficient of static friction between the recording surface of the recording material and the pad is preferably 0.4 or more and 1.5 or less,
More preferably, it is desired to be 0.6 or more and 1.3 or less. The coefficient of static friction between the back surface of the recording material and the paper feed roller is preferably 1.0 or more and 3.0 or less, more preferably 1.
It is preferably 2 or more and 2.0 or less.

When the value of the coefficient of static friction between the recording surface and the back surface of the recording material is smaller than 0.1, blocking occurs when the recording materials are piled up under high temperature and high humidity, and double feeding frequently occurs. To do. The value of the coefficient of static friction between the recording surface and the back surface of the recording material is 1.
When it is larger than 0, the projected image on the OHP becomes dull and a clear image cannot be obtained. If the coefficient of static friction between the recording surface and the back surface of the recording material is less than 1.0 and the coefficient of static friction between the paper feeding roller and the back surface of the recording material is smaller than that, the paper feeding roller is Since the force for feeding the recording material in the sheet feeding direction is smaller than the frictional force between the recording surface and the back surface of the recording material, the recording materials are not separated from each other and are fed in duplicate. If the coefficient of static friction between the pad and the recording surface of the recording material is larger than 1.5 and the coefficient of static friction between the paper feed roller and the back surface of the recording material is smaller than that, the pad is Since the frictional force with the recording material is greater than the force of the paper feed roller that feeds the recording material, the paper feed roller moves the paper feed roller.
The paper feed roller slips during the transportation to the point where the recording material cannot be transported. When the coefficient of static friction between the paper feed roller and the recording surface of the recording material is 3.0 or more, the friction force of the recording material is too large, so that the paper feeding roller cannot rotate and paper cannot be fed. If the coefficient of static friction between the paper feed roller and the recording surface of the recording material is smaller than the value of the coefficient of static friction between the recording surface and the back surface of the recording material, the paper feed roller slips during conveyance to the pad and The recording material cannot be conveyed.

The base material of the paper feeding roller and pad suitable for achieving the above-mentioned coefficient of friction includes synthetic rubber, acrylic, urethane, cork, plastic, etc., so that the coefficient of friction does not decrease due to abrasion. A highly durable material is used. Particularly preferable materials for the paper feed roller and the base material of the pad are synthetic rubber for the paper feed roller and urethane foam for the pad.

As a method of controlling the static friction coefficient of the recording material, a filler may be appropriately added to the ink receiving layer on at least one surface of the recording material, or unevenness may be imparted by printing.

The base material of the recording material is paper, polyester, polyethylene terephthalate, polycarbonate,
Films of polystyrene, polyvinyl chloride, polymethylmethacrylate, cellulose acetate, polyethylene, etc. are used. These films may be a transparent film containing no solid pigment, a white film filled with a white pigment, or a white film formed by fine foaming.

As the white pigment to be filled, for example, titanium oxide, calcium sulfate, calcium carbonate, silica, clay, talc, zinc oxide and the like are used.

The thickness of the substrate is preferably 200 μm or less, more preferably 70 to 130 μm. If the thickness of the substrate exceeds 200 μm, the recording material cannot be discharged because the stiffness is too strong.

As components of the ink receiving layer, albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resin such as soda alginate, polyamide, polyacrylamide, polyvinylpyrrolidone, polyethyleneimine, melamine resin, polyurethane, carboxymethyl. Cellulose, polyvinyl alcohol, polyester,
There are synthetic resins such as sodium polyacrylate.
More than one material is used.

Further, SBR latex, NBR latex, polyvinyl formal, polymethyl methacrylate
, Polyvinyl butyral, polyacrylonitrile, phenol resin, alkyd resin, etc. may be used together or a cross-linking resin may be used.

The thickness of the ink receiving layer is preferably in the range of 2 to 20 μm, and the dry coating material is preferably in the range of 5 to 30 g / m 2. When the dry coating amount is 5 g / m 2 or less, all the ink cannot be absorbed, and the drying property and the fixing property of the ink are poor and a high quality printed image cannot be obtained.

As the filler component, silica-based pigments such as synthetic silica, aluminum silicate, calcium silicate, magnesium silicate, calcium carbonate, titanium oxide, zinc oxide,
Diatomaceous earth, talc, kaolin, clay, bentonite, zirconium oxide, aluminum oxide, aluminum hydroxide, glass beads, synthetic zeolite, inorganic powder such as barium carbonate, silicon, polyethylene, polystyrene, epoxy, benzoguanamine resin, acrylic resin Organic pigments such as plastic pigments and surfactants are used, but not limited thereto, and the ink receiving layer may be formed of a single layer or a plurality of layers.

As a method for imparting an uneven shape by printing, an embossing roll method, a sandblasting method, a pressing method, a molding method, an etching method or the like can be used.

As a method for forming an ink receiving layer on a substrate, the above-mentioned materials are dissolved or dispersed in a suitable solvent to prepare a coating solution, and a roll coating method or a rod bar coating method is used. It may be applied to the substrate by a known method such as a coating method, a spray coating method, an air knife coating method, a dip coating method, and dried or cured.

The load on the paper feed roller of the hopper is 20 g.
The amount is preferably 300 g or less and more preferably 50 g or more and 200 g or less. When the load is less than 20 g, the recording material is fed by the paper feed roller without being separated. If the load is larger than 300 g, the paper feed roller slips and the conveyance becomes impossible.

The load of the pad on the paper feed roller is 100 g
It is preferably 400 g or less and more preferably 150 g
It is preferably 350 g or less. If the load is less than 100 g, the recording materials cannot be separated one by one, causing double feeding. If the load is larger than 400 g, the paper feed roller slips and the conveyance becomes impossible.

The present invention will be specifically described below based on examples.

Example 1 An ink receiving layer was applied to a polyethylene terephthalate film having a thickness of 100 μm to prepare static friction coefficients of 0.05, 0.1, 0.5, 1.0 and 1.3. .

The material of the paper feed roller is synthetic rubber (μ
(Rubber: manufactured by Hokushin Kogyo), and cork and urethane foam were used as the material for the pad.

The load on the paper feed roller of the hopper and pad was set to 200 g.

For each of the recording materials of the above-mentioned Examples and Comparative Examples, the recording material was fed by pressing the back side of the recording material to the paper feed roller by the hopper and rotating the paper feed roller. The recording material is separated and fed by a paper roller and a pad one by one, and a liquid ink is ejected onto the recording material by an on-demand type inkjet recording head in which ink is ejected by a piezo-vibrator to eject the recording material. Inkjet recording was performed using an inkjet recording apparatus that continuously performs the steps from paper feeding to paper ejection in the process. The ink composition used is shown below.

Yellow Ink C.I. I. Direct Yellow 86 2 parts Diethylene glycol 17 parts Water 81 parts Red ink C.I. I. Acid Red 52 2 parts Diethylene glycol 16 parts Water 82 parts Blue Ink C.I. I. Direct Bull-199 3 parts Diethylene glycol 15 parts Water 82 parts Black ink C.I. I. Direct Black 195 5 parts Diethylene Glycol 5 parts Water 90 parts Whether or not the recorded matter thus obtained was sufficiently suitable for the purpose of the present invention was tested and evaluated by the following method. The evaluation results are shown in Table 1. Regarding μ1, μ2, and μ3 in Table 1, μ1 is the coefficient of static friction between the recording surface and the back surface of the recording material, μ2 is the coefficient of static friction between the recording surface of the recording material and the pad, and μ3 is the recording material. The coefficient of static friction between the back surface and the paper feed roller is shown.

[0040]

[Table 1]

The evaluation methods shown in Table 1 were carried out as follows.

(1) Conveyability When 50 sheets of recording material are set in the automatic paper feeding device and the recording material can be conveyed smoothly, ○, when the conveyance is disturbed due to double feeding or slipping Was designated as x.

(2) Image When an image recorded on a recording material was projected by an OHP and observed, the image was clear, and the image was dull, and the image was dull.

(3) Blocking Under the environment of 35 ° C. and 80%, 50 OHP sheets were left stacked for 24 hours, and when the front and back of the OHP sheets were in close contact with each other, x was given, and when there was no problem, ◯ was given. .

(Example 2) A 100 μm polyethylene terephthalate film was coated with an ink receiving layer to prepare a static friction coefficient of 0.5.

The material of the paper feed roller is synthetic rubber (μ
(Rubber: manufactured by Hokushin), urethane foam is used as the material of the pad, and the coefficient of static friction with the recording material is 1.0,
It was set to 2.3.

The load on the paper feed roller of the hopper was set to 10 g, 20 g, 200 g, 300 g and 400 g.
The load on the paper feed roller of the pad is 50g, 100g, 2
It was 50 g, 400 g, and 500 g.

With respect to the recording material, the recording material is pressed by the hopper to the back of the recording material against the paper feed roller under the load of each of the above-mentioned examples and comparative examples, and the paper feed roller is pressed.
By rotating the paper feed roller and the pad for applying the load of each of the above-mentioned examples and comparative examples to the paper feed roller, the recording materials are separated one by one and fed, and the ink is ejected by the piezo vibrator. Ink jet recording was performed using an ink jet recording apparatus in which liquid ink is ejected onto a recording material by the on-demand type ink jet recording head and the steps from sheet feeding to sheet discharging are continuously performed in the process of discharging the sheet. The evaluation results are shown in Table 2 below. Set 50 sheets of recording material in the automatic paper feeder and
When 0 sheets were continuously recorded and the recording material was able to be conveyed smoothly, the mark was ◯, when double feeding was caused, Δ, and when slippage occurred and conveyance was impossible, x was given.

[0049]

[Table 2]

As shown in Tables 1 and 2, the coefficient of static friction μ1 between the recording surface and the back surface of the recording material is 0.1 or more and 1.0 or less, and the coefficient of static friction μ2 between the recording surface of the recording material and the pad is 0.4 to 1.5, the back side of the recording material and the paper feed roller
The coefficient of static friction μ3 is 1.0 or more and 3.0 or less, and μ1 <μ2 <μ3. Further, the load on the paper feed roller of the hopper and the pad is set to a constant value, and the hopper and the paper feed roll are fixed. The recording materials can be easily separated from each other by the rollers and can be conveyed without slipping by the paper feeding roller, and it is possible to prevent the conveyance from being impossible or to prevent double feeding. Furthermore, a clear image can be obtained by inkjet printing, and it is possible to achieve both print quality and blocking.

[0051]

As described above, according to the ink jet recording method of the present invention, the coefficient of static friction between the recording surface and the back surface of the recording material is μ1, and the coefficient of static friction between the recording surface of the recording material and the pad is μ2. Assuming that the coefficient of static friction between the back surface of the recording material and the paper feed roller is μ3, 0.1 ≦ μ1 ≦ 1.0 0.4 ≦ μ2 ≦ 1.5 1.0 ≦ μ3 ≦ 3.0 And using a recording material with μ1 <μ2 <μ3,
Furthermore, by keeping the load on the paper feed roller of the hopper and pad to a constant value, the recording material can be easily separated by the hopper and the paper feed roller, and can be conveyed without slipping on the paper feed roller. It can be carried out, and there is an effect that it is possible to prevent the conveyance from being disabled or the paper feeding being disturbed. Further, there is an effect that a clear image can be obtained by ink jet printing and both print quality and blocking can be achieved at the same time.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a paper feeding method.

FIG. 2 is a diagram showing a relationship of action of force related to sheet feeding.

[Explanation of symbols]

 11 ... Recording material 12 ... Hopper 13 ... Paper feeding roller 14 ... Pad 15 ... Paper feeding roller 21 ... Recording material 22 ... Pad 23 ... Paper feeding roller

Claims (2)

[Claims] 1. A hopper for lifting a recording material having an ink receiving layer provided on a base material to a paper feeding roller, presses the back surface of the recording material to the paper feeding roller under a constant load, and presses the paper feeding roller. -By rotating the roller, the recording material is separated one by one by the paper feed roller and the pressing plate (hereinafter, referred to as a pad) that applies a constant load to the paper feed roller through the recording material, and then the paper is fed. An inkjet recording method is performed in which liquid ink is ejected onto the recording material and the paper is discharged. The coefficient of static friction between the recording surface and the back surface of the recording material is μ1, and the recording surface of the recording material and the pad are Assuming that the coefficient of static friction is μ2 and the coefficient of static friction between the back surface of the recording material and the paper feed roller is μ3, 0.1 ≦ μ1 ≦ 1.0 0.4 ≦ μ2 ≦ 1.5 1.0 ≦ μ3 ≦ 3.0 and μ1 <μ2 <μ3 An ink jet recording method according to symptoms. 2. A recording material having an ink receiving layer provided on a base material is fed by pressing a back surface of the recording material to a feeding roller by a hopper and rotating a feeding roller. It is an ink jet recording method in which the recording material is separated and fed by a roller and a pad one by one, liquid ink is ejected onto the recording material, and the paper is ejected, and the load applied to the feeding roller by the hopper. 20 g
The inkjet recording method according to claim 1, wherein the amount is 300 g or less and the load applied to the paper feed roller by the pad is 100 g or more and 400 g or less.