JP2006096501A - Offset sheet-fed printing method of ink jet recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method of an ink jet recording material for a post card capable of restricting the generation of dirty in a blanket and having excellent damage resistance, in regard to offset sheet-fed printing method using an ink jet recording material using a polyolefin resin coated paper or a high molecular film as a base material and provided with an ink receiving layer comprising inorganic minute particles and hydrophilic binder, especially in regard to a printing method of an addressee surface of the ink jet recording material for a post card. <P>SOLUTION: In this offset sheet-fed printing method using the ink jet recording material provided with the ink jet receiving layer comprising inorganic minute particles and hydrophilic binder in at least one surface of the polyolefin resin coated paper or the high molecular film as a base material, width of a roller of a feeder part is set at 15.0 mm or more, or hardness of the roller of the feeder part is set at 70° or less. Especially, remarkable effect is recognized in the ink jet recording material provided with the ink receiving layer having a cavity ratio at 45% or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an offset sheet-fed printing method using an inkjet recording material provided with an ink receiving layer containing inorganic fine particles and a hydrophilic binder on at least one side of a resin-coated paper or polymer film coated with a polyolefin resin, More specifically, the present invention provides an offset sheet-fed printing method for a postcard ink jet recording material that has little blanket contamination and good scratch resistance in address side printing.

  As a recording material used in the inkjet recording system, a porous ink receiving layer comprising a pigment such as amorphous silica and a water-soluble binder such as polyvinyl alcohol on a support called ordinary paper or inkjet recording paper. The recording material provided is known.

  Many recording materials obtained by applying a silicon-containing pigment such as silica to a paper support together with an aqueous binder have been proposed (see, for example, Patent Documents 1 and 2).

  Also, many techniques have been disclosed for recording materials using synthetic silica fine particles (hereinafter referred to as vapor phase silica) by a vapor phase method (see, for example, Patent Documents 3 and 4). Vapor phase silica is an ultrafine particle having an average primary particle size of several nanometers to several tens of nanometers, and is characterized by high gloss and high ink absorbability. However, because of the ultrafine particles, there is a problem that scratches are likely to occur during conveyance of offset printing.

  There has been proposed a recording paper that improves the transportability of the printer by containing a specific lubricant on the opposite surface of the ink-receptive coating layer (see, for example, Patent Document 5), but has problems of blocking during storage, ink reception There is a problem of surface scratches. In addition, a recording sheet has been proposed in which a spherical fine particle polymer is contained in the backing layer of the support (see, for example, Patent Document 6). However, the spherical fine particle polymer alone has scratches on the surface of the ink receiving layer during production or processing. In particular, when fine inorganic fine particles are used in the ink receiving layer, there is a problem that scratches are easily noticeable.

  Conventionally, paper has been generally used as a support for inkjet recording materials, and the paper itself has a role as an ink absorbing layer. In recent years, photo-like recording sheets have been demanded, and recording sheets using a paper support have problems such as gloss, texture, water resistance, cockling after printing (wrinkles or undulations), and are water-resistant processed. Paper supports, for example, resin-laminated paper (polyolefin resin-coated paper) in which a polyolefin resin such as polyethylene is laminated on both sides of the paper, polymer films, and the like have been used (for example, see Patent Document 7). However, unlike the paper support, these water-resistant supports have a high surface smoothness provided with an ink receiving layer, and particularly when fine inorganic fine particles are used in the ink receiving layer, there is a problem that scratches are easily noticeable. is there.

Conventionally, both sides have ink jet recording suitability like postcards, and when surface-like high glossiness and print image quality are required, it is particularly glossy for improving transportability and scratch resistance on the surface. Due to the limitation due to the decrease, it was difficult and sufficient characteristics could not be obtained.
Under such circumstances, double-sided recording paper for ink-jet recording in which a pigment layer is provided on a paper substrate has been proposed (see, for example, Patent Document 8), but sufficient glossiness and a printed image could not be obtained. In addition, a proposal has been made to bond a base paper having an ink-receiving layer with a polyolefin resin laminate layer (see, for example, Patent Document 9). However, the transportability and scratch resistance of the printer were not sufficient.
Furthermore, there has been proposed an ink jet recording paper having a porous ink absorbing layer on one side of a paper substrate via a relatively thin hydrophobic resin layer and a direct ink absorbing layer on the other side ( For example, refer to Patent Document 10). Since the hydrophobic resin layer is provided only on one side, the problem of curling is likely to occur, and there is a problem in the transportability of the printer. In particular, it is common to print a border or the like in advance on the ink receiving layer on the address side of the postcard. However, there is a high possibility that scratches will occur during printing. In particular, when the ink receiving layer on the communication surface is highly glossy and the ink-jet ink has high absorbability, there is a problem that scratches are likely to occur even when transported by a printer.

Conventionally, a resin-coated paper-type support whose base paper surface is coated with a polyolefin resin is known as a photographic support.
A photographic support is disclosed in which a base paper is coated with a film-forming resin, preferably a polyolefin resin (see, for example, Patent Documents 11 and 12). In addition, since the rapid photographic development processing method for silver halide photosensitive materials has been applied, photographic supports in which both sides of the base paper are coated with a polyethylene resin have been mainly put into practical use for photographic printing paper, If necessary, the image forming resin layer usually contains a titanium dioxide pigment in order to impart sharpness.

  As for the resin-coated printing material whose base paper surface is coated with a polyolefin resin, a printing paper is disclosed in which a synthetic resin layer highly filled with an inorganic filler is provided on a base paper (see, for example, Patent Document 13). Moreover, the adhesive improvement of the ink by sharing a modified polyolefin resin, an acrylic ester resin, and polyolefin resin is disclosed by the resin coating layer (for example, refer patent document 14, 15).

  These resin-coated printing materials are usually produced by a so-called extrusion coating method in which a polyolefin resin such as polyethylene is melted at a high temperature and cast onto the surface of the base paper. At that time, polyolefin resin is a characteristic required for printing applications, scratches on the surface due to scratches, so-called scratch-resistant resins generally have poor adhesion between the base paper and the resin, and during printing Separation may occur due to Inktacks. Prior to extrusion coating, the surface of the base paper is activated in advance by corona treatment or the like. However, the adhesive strength between the base paper and the resin layer is lowered, and so-called blanket contamination is likely to occur.

  In relation to this problem, a technique related to a photographic support has been proposed in which various substances called so-called primers are applied to the surface of a polyolefin resin-coated paper to improve the adhesion between the base paper and the resin layer. Yes. Further, a technique relating to a photographic support made of a polyolefin resin-coated paper in which a copolymer having at least a salt of ethylene and acrylic acid (or methacrylic acid) as a constituent element is applied to the surface of the paper has been proposed (for example, , See Patent Document 16). Furthermore, a polyolefin resin-coated paper in which a liquid containing polyvinyl alcohol and an isocyanate compound is applied to the paper surface, or a copolymer containing at least ethylene and an unsaturated dicarboxylic acid or a derivative thereof is applied to the paper surface. A technique relating to a photographic support comprising the above has also been proposed (see, for example, Patent Documents 17 and 18).

In addition to the above patent documents, the following technologies have been proposed.
There is a disclosure of a photographic support made of a polyolefin resin-coated paper in which an ionomer is coated on the surface of the paper (see, for example, Patent Document 19).
There is a disclosure about a photographic support made of polyolefin resin-coated paper in which a layer containing finely dispersed aluminum oxide is provided on paper (see, for example, Patent Document 20)
There is a disclosure of a photographic support made of a polyolefin resin-coated paper in which an aqueous dispersion containing an ethylene / acrylic acid copolymer is coated on a base paper (for example, Patent Document 21,
22).
There is a disclosure of a photographic support comprising a polyolefin resin-coated paper having a copolymer polymer comprising isobutylene, N-phenylmaleimide and maleate on the surface of the base paper (see, for example, Patent Document 23).
There is a disclosure of a photographic support comprising a polyolefin resin-coated paper having a silane coupling agent on the surface (see, for example, Patent Document 24).

  However, even when these substances disclosed in the prior art are applied to the base paper, the ink tack at the time of printing is particularly in the case of coating a resin composition containing a polyolefin resin or an antistatic agent with good scratch resistance. There is no or no effect in improving the peelability due to ink, and the effect due to ink tack at the time of printing is different from the evaluation of adhesion between the base paper and the resin layer for photography. Expected.

  As a technique for coating a coating layer on a film or laminated paper, a chart or map paper in which a layer containing a pigment, a binder, a water repellent, and a surfactant is provided on the laminated paper is disclosed (for example, patents). Reference 25). Also disclosed is a paper manufacturing method in which a colloidal silica and ammonium bisulfate-containing layer is provided on a polyolefin laminate layer (see, for example, Patent Document 26). Furthermore, there is a disclosure of synthetic paper in which a layer of latex and inorganic powder is coated on a stretched film for the purpose of improving ink adhesion (see, for example, Patent Document 27).

  However, even if the layers (surface layers) disclosed in these prior arts are coated on laminated paper and film, the effect of improving ink adhesion is small, and it is necessary to increase the coating amount in order to increase the effect. When the coating amount is increased, the inherent high smoothness and glossiness of the laminated paper and film are lowered. In addition, the adhesion between the laminated paper or film and the surface layer is likely to deteriorate.

The present inventors have intensively studied to solve the above problem, but it is very difficult to impart the contradictory properties of ink jet suitability and offset suitability, and there is a natural limit from the formulation side of the formulation. I found it.
As described above, various studies have been made on the resin-coated paper for printing and the ink jet recording material from the viewpoint of blending. On the other hand, for photographic supports, resin-coated papers coated with a polyolefin resin are known, but no offset sheet-fed printing method for postcard inkjet recording materials that has taken measures from the offset printing side as in the present invention has yet to be found. .
JP-A-55-51583 Japanese Patent Laid-Open No. 64-11877 Japanese Patent Publication No. 3-56552 Japanese Patent Laid-Open No. 11-34481 Japanese Patent Laid-Open No. 6-55830 Japanese Patent Laid-Open No. 7-180025 JP 2001-96897 A JP-A-8-260382 JP-A-8-11422 JP 2000-301823 A Japanese Patent Publication No. 55-12584 US Pat. No. 3,501,298 JP-A-2-33399 Japanese Patent Laid-Open No. 3-64598 Japanese Patent Laid-Open No. 3-64599 Japanese Patent Publication No.51-25337 JP 54-56422 A Japanese Patent Laid-Open No. 54-111331 JP-A-55-4027 Japanese Patent Publication No.59-12167 JP 61-230142 A JP-A-1-180538 JP-A-4-149431 JP-A-4-149432 Japanese Utility Model Publication No. 51-15552 Japanese Patent Publication No.55-29200 JP 62-53345 A

  Accordingly, an object of the present invention relates to a method for offset sheet-fed printing of an ink jet recording material in which at least one side of the ink receiving layer has high gloss and has good ink absorbability, and can provide a photo-like image quality and good tactile sensation. An object of the present invention is to provide an offset sheet-fed printing method for an inkjet recording material for postcards having good printability when frame printing or the like is applied to the surface.

As a result of intensive studies by the present inventors in order to solve the above-described problems, an inkjet in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on at least one surface of a polyolefin resin-coated paper or a polymer film as a base material. In the printing method of the recording material, the roller width of the feeder portion is 15.0 mm or more, the hardness of the roller of the feeder portion is 70 ° or less, or a combination thereof, that is, the roller width is 15.0 mm or more and the hardness is It is achieved by making it 70 degrees or less.
Furthermore, this can be achieved when the inkjet recording material is a postcard inkjet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on both sides of a substrate. In particular, a remarkable effect is observed in an ink jet recording material provided with an ink receiving layer having a porosity of 45% or more.

  According to the present invention, even with an ink jet recording material having good ink jet aptitude, offset sheet-fed printing can be performed without any printing problems.

The printing paper of the present invention will be described in detail below.
The double-sided polyolefin resin-coated paper used as a substrate in the present invention comprises a base paper mainly composed of a pulp component and a polyolefin resin. The base paper may be composed of ordinary natural pulp, or synthetic pulp or synthetic fiber. Among these, natural pulp paper mainly composed of wood pulp of softwood pulp, hardwood pulp and softwood hardwood mixed pulp is effective.

These base papers can contain various polymer compounds and additives. For example, cationized starch, cationized polyacrylamide, anionized polyacrylad, carboxy-modified polyvinyl alcohol, gelatin, etc. as dry paper strength enhancing materials, fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, petroleum resin emulsions as sizing agents Clay, kaolin, calcium carbonate, barium sulfate, titanium oxide, etc. as pigments, melamine resin, urea resin, epoxidized polyamide resin, etc. as wet paper strength enhancers, polyvalent metal salts such as aluminum sulfate, aluminum chloride as fixing agents Cation-modified polymers such as cationized starch, caustic soda, sodium carbonate, hydrochloric acid, etc. as pH regulators, salt, bow glass, etc. as inorganic electrolytes, other dyes, fluorescent whitening agents, latex, etc. Out That.
Also, the base paper is preferably one having good surface smoothness, such as being compressed by applying pressure during or after paper making, and it needs moderate rigidity for postcard use, and its basis weight is 80 to 250 g / m ² is common, and the thickness is 70 to 260 μm.

The polyolefin resin that coats both surfaces of the substrate is a homopolymer of olefin such as low density polyethylene, high density polyethylene, polypropylene, polybutene, polypentene, or ethylene-propylene copolymer. White pigments such as zinc oxide, fatty acid metal salts such as zinc stearate and calcium stearate, and pigments and dyes such as ultramarine blue, bitumen and phthalocyanine blue. Among these additives, those which do not adversely affect the whiteness as in the case of the above base paper are appropriately selected. Among these additives, it is preferable to use titanium oxide as the pigment, and the coating amount of the resin covering the paper substrate is 10 g / m ^{2 to} 40 g / m ² is preferable. The olefin resin coating method is not particularly limited as long as the paper substrate can be coated, but a method of coating the molten resin with an extruder is preferable from the viewpoint of productivity and finish.

The polyolefin resin-coated paper or polymer film used in the present invention can be provided with a back coating layer on the back surface according to the purpose. Specifically, as means for solving the curl, the balance factor of these coating amounts is large, and it is preferable to reduce the difference between the front and back as much as possible.
In addition, an undercoat layer can be provided on the surface according to the purpose in order to impart printability. Specifically, it is more preferable that there is an aqueous coated undercoat layer containing a water-soluble binder such as PVA or gelatin and its hardener.

  The printing method used in the present invention is limited to a sheet-fed offset printing machine among offset printing, screen printing, and gravure printing. The reason for this is that an offset rotary press or a gravure rotary press is not a big problem because it is hardly damaged because of a roll method.

  The surface on which the ink receiving layer on the communication surface side of the present invention is coated is mainly formed by heating and melting polyolefin resin on one side of a base paper with an extruder, and extruding it into a film between a base paper and a cooling roll, and pressing and cooling. Manufactured. At this time, the cooling roll is used to form the surface shape of the polyolefin resin coating layer, and the surface of the resin layer is shaped into a mirror surface, a fine surface, or a patterned silk or mat shape depending on the shape of the cooling roll surface. Can be processed. From the gloss of the ink receiving layer, the thickness of the resin layer is 15 to 40 μm, preferably 20 to 35 μm.

  The surface on which the ink receiving layer of the addressed surface of the present invention is coated is obtained by heating and melting polyolefin resin with an extruder as in the case of the communication surface, and extruding it into a film between the base paper and the cooling roll, followed by pressure bonding and cooling. Manufactured.

  In the present invention, a polymer film is used as the substrate in addition to the polyolefin resin-coated paper. Specifically, a known resin such as polypropylene, polyethylene, or polyester is stretched and used as a film. In particular, polypropylene resin is good in scratch resistance, followed by high-density polyethylene resin.

  The inorganic fine particles used in the ink receiving layer of the present invention have an average primary particle size of 5.0 μm or less, specifically, synthetic silica, alumina, alumina hydrate, calcium carbonate, magnesium carbonate, titanium dioxide. Etc. are used. Particularly preferably, synthetic silica, alumina, and alumina hydrate are used. From the viewpoint of ink absorptivity, these pigments preferably have an average primary particle size of 0.005 to 0.5 μm and an average secondary particle size of 0.08 to 8 μm.

As the hydrophilic binder used in the ink receiving layer of the present invention, gelatin, polyvinyl pyrrolidone, pullulan, polyvinyl alcohol and the like and derivatives thereof are used, and gelatin, polyvinyl alcohol and derivatives thereof are preferable.
From the viewpoint of ink absorptivity, the amount of the hydrophilic binder is 5 to 150% by mass, preferably 10 to 100% by mass of the inorganic fine particles.

The coating amount of the ink receiving layer of the address side of the present invention is preferably 1~12g / m ^2, more preferably cracking of the ink receiving layer by a 3 to 10 g / m ^2, printing resistance, scratch resistance and better Become.
In the present invention, in addition to the surfactant and the hardener, the ink receiving layer further includes a coloring dye, a coloring pigment, an ink dye fixing agent, an ultraviolet absorber, an antioxidant, a pigment dispersant, and an antifoaming agent. , Various known additives such as leveling agents, preservatives, optical brighteners, viscosity stabilizers, and pH adjusters may be added.

  In the present invention, the application method of the ink receiving layer and the undercoat layer on the communication surface, the address surface is not particularly limited, and a known coating method can be used. For example, there are a slide bead method, a curtain method, an extrusion method, an air knife method, a roll coating method, a Ked bar coating method, a bar cotter method, a blade method, a dip method, and the like.

  Specific examples of the printing material used in the present invention include offset ink, dampening water, and PS plate, but general materials are used except that the present invention is limited.

The present invention is characterized in that the roller of the feeder portion of the offset sheet-fed printing press is defined.
In particular, since the postcard address surface is provided with an ink-jet ink receiving layer, the coating layer strength is significantly weaker than conventional postcards (whether the address surface is not coated or coated). The reason for this is that, in the present invention, a polyolefin resin-coated paper or a polymer film is used as a base material, and therefore, there is no base cushioning property compared to a conventional paper base. It is thought that it will be destroyed. For this reason, especially in the present invention, the width and material of the roller of the feeder section on the printing press, that is, the physical properties, JIS-A hardness is very important.

  That is, the width of the roller of the feeder part is 15.0 mm or more, preferably 20.0 mm or more. Alternatively, it can be achieved by setting the roller hardness of the feeder portion to 70 ° or less, preferably 40 ° or less. Specifically, here, the width of the roller refers to the width in contact with the ink receiving layer. When the contact width of the roller is less than 15.0 mm, the stress applied to the ink receiving layer becomes strong, so that the fragile coating layer is liable to be broken, and as a result, blanket stains of the printing press are induced. Similarly, when the JIS-A hardness of the roller exceeds 70 °, the cushioning property of the roller is lost, so that the coating layer is broken and the blanket becomes dirty.

  Rollers in the feeder section of conventional printing presses are generally roughly classified into plastic, rubber, and brush systems. Among these, the brush roller hits the ink receiving layer at the tip of the hair, whereas the plastic roller and rubber roller hit the destination surface as a surface compared to the brush system, so the influence of the contact width is large. I found. Further, conventional rollers used in printing presses are generally harder from the viewpoint of durability. Specifically, a JIS-A hardness of about 80 ° or more and a width of about 10 mm or less are usually used.

In the offset sheet-fed printing method using an inkjet recording material using a polyolefin resin-coated paper or a polymer film as a base material and provided with an ink receiving layer containing inorganic fine particles and a hydrophilic binder on at least one side, This is achieved by setting the width of the roller of the feeder part to 15.0 mm or more, or the hardness of the roller of the feeder part to 70 ° or less.
That is, if these conditions are not met, the coating layer of the ink receiving layer is likely to be broken, and the broken coating layer portion is liable to cause blanket contamination due to the tack and printing pressure of the printing ink.

The present invention is limited to inkjet recording materials, and does not include offset paper, so-called coated paper.
In general, the porosity of the coated paper is 30% or less, whereas the porosity of the ink receiving layer of the ink jet recording material of the present invention is usually larger than 30%, particularly 45% or more, and the effect of the present invention is remarkable. Recognized. The upper limit of the porosity is determined from the strength required for handling, but is generally 70 to 80%.

In the coated paper having a coating layer porosity of 30% or less, the structure of the coating layer is relatively dense as compared with the ink jet recording material, so that the strength can be sufficiently maintained even with a conventional roller. However, in an ink jet recording material having a high porosity and a weakly structured ink receiving layer, the stress applied to the ink receiving layer is increased in the conventional roller as described above, and the fragile coating layer is destroyed. In this case, the blanket of the printing press is induced.
The porosity defined by the present invention can be confirmed, for example, by measuring using a mercury porosimeter (Pore Sizer 9320-PC2 manufactured by Shimadzu Corporation).

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example. In addition, a part represents a mass part.

Example 1
<Preparation of polyolefin resin-coated paper support>
A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and hardwood bleached sulfite pulp (LBSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. As a sizing agent, 0.5% by mass of alkyl ketene dimer with respect to pulp, 1.0% by mass of polyacrylamide with respect to pulp as a strengthening agent, 2.0% by mass of cationized starch with respect to pulp, and polyamide epichlorohydrin resin 0.5 mass% of pulp was added and diluted with water to give a 1 mass% slurry (parts). This slurry was made into a paper having a basis weight of 170 g / m ² using a long paper machine, dried and conditioned to obtain a polyolefin resin-coated paper having a thickness of 180 μm. A polyethylene resin composition in which 10% by mass of anatase-type titanium is uniformly dispersed with respect to 100% by mass of low-density polyethylene having a density of 0.918 g / cm ³ is melted at 320 ° C. at 320 ° C. The resin layer on the surface was provided by extrusion coating using a cooling roll that had been subjected to extrusion coating to a thickness of 30 μm / min and processed to a fine surface. On the other side, a blend resin composition of 70 parts by mass of a high density polyethylene resin having a density of 0.962 g / cm ³ and 30 parts by mass of a low density polyethylene resin having a density of 0.918 was similarly melted at 320 ° C. to obtain a thickness. The resin layer on the back surface was provided by extrusion coating using a cooling roll that had been extrusion coated so as to have a thickness of 25 μm and subjected to rough surface processing.

After subjecting both surfaces of the polyolefin resin-coated paper to high-frequency corona discharge treatment, an undercoat layer having the following composition per side was coated and dried so that the gelatin was 500 mg / m ² to prepare a support. The thickness of each undercoat layer was 0.5 μm. In addition, a part represents a mass part.
<Underlayer>
Lime-processed gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome alum 10 parts

An ink receiving layer coating solution having the following composition was applied to the back surface of the resin-coated paper by a slide coating test coater so as to have a volume of 17 cm ³ / m ² and dried (the volume ratio of gelatin was 21% by volume). Subsequently, the following ink-receiving layer coating solution for the communication surface was applied to the surface of the resin-coated paper with a slide coating test coater so as to have a volume of 36 cm ³ / m ² and dried (volume ratio of polyvinyl alcohol is 8% by volume). . The porosity of the ink receiving layer on the address side and the ink receiving layer on the communication side was 55% and 40%, respectively.

<Ink receiving layer coating solution for address>
Wet silica 100 parts (P78A made by Mizusawa Chemical Industry Co., Ltd., average particle size 3 μm)
10 parts of polyethylene particles (average particle size 0.15 μm)
80 parts of gelatin (Nikka Gelatin, IK-2000)
Surfactant 0.3 part

<Ink-receiving layer coating solution for communication surface>
Gas phase method silica 100 parts (average primary particle size 7 nm, average secondary particle size 150 nm, specific surface area 300 m ² / g by BET method)
4 parts of dimethyldiallylammonium chloride homopolymer (Daiichi Kogyo Seiyaku Co., Ltd., Charol DC902P, molecular weight 10,000)
0.5 part of spherical particles (silica particles H121 manufactured by Asahi Glass Co., Ltd., average primary particle size 12 μm)
1 part of spherical particles (Polystyrene, SBX-6, average primary particle size 6 μm, manufactured by Sekisui Chemical Co., Ltd.)
Boric acid 3 parts Polyvinyl alcohol 26 parts (degree of saponification 88%, average degree of polymerization 3500)
Surfactant 0.3 part

After the recording material (postcard large size) produced as described above was left to stand at 23 ° C. and 55% RH for a day and night, 5000 sheets of offset printing were performed on the address surface under the following conditions, and the target inkjet ink for postcards was used. A recording material was obtained.
・ Printing machine: Lislon two-color machine manufactured by Komori Corporation ・ Ink: TK High Unite Red manufactured by Toyo Ink ・ Blanket: S-7000 manufactured by Kinyo
-Printing speed: 8000 revolutions / hour-Roller width: 15.0 mm
-Roller hardness: 70 °
At this time, the porosity of the ink receiving layer on the address side was 48%, and the porosity of the ink receiving layer on the communication surface was 59%.

(Example 2) to (Example 7), (Comparative Example 1) to (Comparative Example 3), (Reference Example 1)
In Example 1, offset printing was performed on the address side under the printing conditions shown in the table, and the intended inkjet recording material for postcards was obtained.
"Evaluation methods"
The printing results obtained in Examples / Comparative Examples and Reference Examples were evaluated for the following items and summarized in Table 1.
<Blanket dirt>
The degree of dirt on the blanket after printing 5000 sheets was evaluated with the naked eye. The evaluation criteria were as follows.
◎: No problem in actual use, ○: Slight dirt is observed but there is no problem in actual use, △: Dirt is observed and there is a problem in actual use, x: Not suitable for practical use.
<Scratch resistance>
As for the scratch resistance, three consecutive sheets including the 1000th sheet, the 3000th sheet, and the 5000th sheet were extracted during the printing of 5000 sheets, and the level of occurrence of scratches due to the roller in the feeder portion of the printing press was evaluated with the naked eye.
◎: No problem in actual use, ○: Slight scratches are observed, but there is no problem in actual use, △: Scratches are observed and there are slight problems in actual use, ×: Not suitable for practical use.
<Comprehensive evaluation>
The above items were evaluated comprehensively, and the effect of the invention was found to be 3 or more in a 5-step evaluation. The results are shown in Table 1.

From the results in Table 1, in the offset sheet-fed printing method using an inkjet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on at least one side of a polyolefin resin-coated paper or a polymer film as a base material, This can be achieved by setting the width of the roller of 15.0 mm or more or the hardness of the roller of the feeder portion to 70 ° or less. In particular, a remarkable effect is observed in an ink jet recording material provided with an ink receiving layer having a porosity of 45% or more.
The reason why Example 7 is better than Example 1 is that the communication surface is not required to be as writable as the address surface for the address surface that requires a certain degree of writability, and thus the smoothness is greatly different.

  According to the present invention, an offset sheet-fed printing method using an inkjet recording material using a polyolefin resin-coated paper or a polymer film as a base material and provided with an ink receiving layer containing inorganic fine particles and a hydrophilic binder on at least one side. It is possible to provide a printing method of an ink jet recording material with less contamination and good scratch resistance.

Claims (5)

  In a printing method of an ink jet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on at least one side of a polyolefin resin-coated paper or polymer film as a base material, the roller width of a feeder portion of a printing machine is 15 An offset sheet-fed printing method for an ink jet recording material, characterized by being 0.0 mm or more.   In a printing method of an ink jet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on at least one side of a polyolefin resin-coated paper or polymer film as a base material, the roller hardness of a feeder portion of a printing press is 70 An offset sheet-fed printing method for inkjet recording materials, characterized in that the temperature is not more than °.   In a printing method of an ink jet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on at least one side of a polyolefin resin-coated paper or polymer film as a base material, the roller width of a feeder portion of a printing machine is 15 An offset sheet-fed printing method for an ink jet recording material, wherein the offset sheet has a hardness of 0.0 mm or more and a hardness of 70 ° or less.   The ink jet recording material according to claim 1, wherein the ink jet recording material is a postcard ink jet recording material in which an ink receiving layer containing inorganic fine particles and a hydrophilic binder is provided on both surfaces of a substrate. Offset sheet-fed printing method for materials.   5. The offset sheet-fed printing method for an ink jet recording material according to claim 1, wherein an ink receiving layer having a porosity of 45% or more is provided in the ink jet recording material.