JP6698673B2 - Offset printing composite material, and adhesive sheet, postcard, and window film using the same - Google Patents

Description

  The present invention relates to a composite material for offset printing, and an adhesive sheet, postcard, and window film using the same.

  In recent years, digitization is rapidly progressing in various printing processes such as an inkjet recording method, an electrophotographic method using powder toner, and an offset printing method. In particular, digital offset printing is a virtually complete plateless digital process that does not require the step of producing a prepress, which is an intermediate between digital data and printing, and surpasses the inkjet recording method and electrophotographic method described above. Since it is possible to print with high image quality, it is widely used as a high-definition printing method.

  In such digital offset printing, by adopting an offset cylinder covered with a replaceable elastic blanket, wear of the plate holding the ink image generated from digital data is prevented, and the ink image is It is also possible to transfer to a print medium composed of paper, plastic, other materials, or the like.

  As a printing medium to be used for offset printing, the present applicants have proposed a polyethyleneimine-based modified product as a copolymerization component on the surface of a support made of a resin film containing a thermoplastic resin such as a polyolefin resin or a polyester resin as a main component. It has been proposed that a recording paper obtained by applying and drying a coating liquid containing an acrylic copolymer containing styrene (for example, see Patent Document 1).

JP, 2005-077771, A

  By the way, in recent years, in various printing processes, high image quality in digital color printing is being spurred. Specifically, the dot size and the thin line width of the ink generated from digital data have been further narrowed, and in particular, the sharpness of edges of halftone dots and minute text display has been remarkably improved.

  Along with the reduction of the dot size and the narrow line width, the transferability of the ink from the offset cylinder to the print medium (transferability) tends to decrease, and the adhesion of the ink to the print medium after the transfer tends to decrease. Therefore, from the viewpoint of high image quality, further improvement has been required on the print medium side.

  On the other hand, there is an increasing demand for window decorations in windows, showcases, partitions, etc. of commercial facilities and offices. However, no window film has been reported yet that can realize the above-mentioned high image quality and realize various color variations and graphic expressions.

The present invention has been made in view of such background art. An object of the invention is to provide a composite material for offset printing, which is excellent in ink transferability and adhesion.
Another object of the present invention is to provide an adhesive sheet, postcard, etc. of a composite material for offset printing, which is excellent in ink transferability and adhesion.
Further, another object of the present invention is to provide a composite material for offset printing, which has excellent transferability and adhesion of ink, and transparency, and which has a paper feeding/discharging performance suitable as a print medium for offset printing. Especially. Another object of the present invention is to provide a window film or the like that is not only excellent in transparency, but can realize various color variations and graphic expressions with high image quality.

  It should be noted that the present invention is not limited to the purpose described here, and it is also possible to achieve the operational effects that are obtained by the respective configurations shown in the modes for carrying out the invention to be described later and are not obtained by the conventional technology. It can be positioned as another purpose.

  As a result of intensive investigations to solve the above problems, the present inventors have surprisingly used a specific adhesive, which has been conventionally used for bonding various metal plates or plastic films, in the ink coating layer. As a result, they have found that the above problems can be solved, and have completed the offset printing composite material of the present invention.

That is, the present invention provides various specific embodiments shown below.
[1] A support, and an ink coating layer provided on at least one surface side of the support, wherein the ink coating layer has a hydroxyl group-modified olefin adhesive and/or an acid value of 1 to 50 mgKOH. /G of an acid-modified olefin-based adhesive is contained in the composite material for offset printing.
[2] The offset printing according to the above [1], wherein the ink coating layer contains at least a white pigment, a urethane resin, and the hydroxyl group-modified olefin adhesive and/or the acid-modified olefin adhesive. For composites.
[3] The ink coating layer has a solid content of 5 to 40% by mass of a white pigment, 5 to 40% by mass of a urethane resin, and 30 to 80% by mass of the hydroxyl group-modified olefin adhesive. / Or the offset printing composite material according to the above [2], which contains at least the acid-modified olefin adhesive.
[4] The composite material for offset printing according to any one of the above [1] to [3], wherein the solid content of the ink-adhered layer is 0.5 to 10 g/m ² per side.
[5] The offset printing according to any one of the above [2] to [4], wherein the white pigment contains one or more selected from the group consisting of titanium oxide, barium sulfate, calcium sulfate, and zinc oxide. Composite material.

[6] The hydroxyl group-modified olefin-based adhesive is a hydroxyl group-modified product of an olefin-based (co)polymer, and the olefin-based (co)polymer is ethylene, propylene, butene-1,4-methyl-1-. In any one of the above [1] to [5], which is a homopolymer or copolymer of one or more monomers selected from the group consisting of pentene, hexene-1, octene-1, styrene, and conjugated dienes. The composite material for offset printing described.
[7] The acid-modified olefin adhesive is an acid-modified olefin (co)polymer, and the olefin (co)polymer is ethylene, propylene, butene-1,4-methyl-1-. [1] to [6], which is a homopolymer or copolymer of one or more monomers selected from the group consisting of pentene, hexene-1, octene-1, styrene, and conjugated dienes. Composite material for offset printing.
[8] The offset printing composite material according to any one of the above [1] to [7], wherein the ink coating layer further contains an anti-blocking agent.
[9] The offset printing according to any one of the above [1] to [8], wherein the support contains at least a thermoplastic resin and one or more selected from the group consisting of an inorganic filler and an organic filler. For composites.

[10] The offset printing composite material according to any one of the above [1] to [9], and the pressure-sensitive adhesive layer provided on at least one surface side of the offset printing composite material, Adhesive sheet.
[11] A postcard comprising the pressure-sensitive adhesive sheet according to [10] above, and a recording paper provided via the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet.

[12] The support is a transparent support containing a polyester resin, and the ink-adhering layer contains the hydroxyl-modified olefin adhesive and/or the acid-modified olefin adhesive and a polyisocyanate compound. The composite material for offset printing according to any one of [1] to [8] above, which contains and has an opacity of 10% or less measured according to JIS-P8149:2000.
[13] A window film comprising the composite material for offset printing according to the above [12].

ADVANTAGE OF THE INVENTION According to this invention, the composite material for offset printing etc. which are excellent in the transferability and adhesiveness of ink can be provided. Further, according to the present invention, it is possible to provide a pressure-sensitive adhesive sheet, postcard, etc. of a composite material for offset printing, which is excellent in ink transferability and adhesion. Furthermore, according to the present invention, it is also possible to provide a composite material for offset printing, which has excellent transferability and adhesion of ink, transparency, and blocking resistance suitable as a print medium for offset printing.
In particular, the composite material for offset printing of the present invention has ink transferability and adhesion that can be applied to digital offset printing using liquid ink containing ink particles having an average particle size of 0.5 to 4 μm. Therefore, it is possible to realize high-quality printing superior to the conventional inkjet recording method, the conventional electrophotographic method using powder toner, the conventional offset printing method, and the like. Further, by using the offset printing composite material of the present invention, not only an opaque adhesive sheet, an opaque postcard, and excellent transparency, it is possible to realize various color variations and graphic expressions with high image quality, a window film Etc. can be provided.

It is a schematic cross section which shows the composite material for offset printing of one Embodiment of this invention. It is a schematic cross section which shows the adhesive sheet of 1st embodiment of this invention. It is a schematic cross section which shows the postcard of one Embodiment of this invention.

  Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Each of the following embodiments is an example for explaining the present invention, and the present invention is not limited to the embodiment. Further, hereinafter, unless otherwise specified, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, for example, the notation of a numerical range of “1 to 100” includes both the lower limit value “1” and the upper limit value “100”. The same applies to other numerical ranges.

[Composite material for offset printing]
FIG. 1 is a schematic cross-sectional view showing the layer structure of a composite material 11 for offset printing according to an embodiment of the present invention. The offset printing composite material 11 includes a support 21 and an ink coating layer 31 provided on at least one surface 21a side of the support 21. This offset printing composite material 11 can be used as a sheet (composite sheet) for offset printing.

[Support]
The support 21 used here supports the ink coating layer 31 and imparts printability such as mechanical strength and stiffness to the offset printing composite material 11. A well-known thing can be used for the support body 21, and the kind is not specifically limited. For example, a non-woven fabric material made of organic fibers, inorganic fibers, or a composite material combining these; a resin film (synthetic paper) obtained by forming a thermoplastic resin, a thermosetting resin, or a composite material combining these into a film; pulp. Paper materials such as paper, metal vapor-deposited paper, and resin laminated paper;

  Among these, the support 21 is preferably one that approximates the texture of paper, and one that is excellent in water resistance. From such a viewpoint, a water resistant support such as synthetic paper, pulp paper, metal vapor deposition paper, or resin laminated paper is preferable.

[Synthetic paper]
In particular, from the viewpoint of easy adjustment of mechanical strength such as rigidity and tear resistance, physical characteristics such as smoothness and opacity, and chemical characteristics such as water resistance and chemical resistance, the support 21 is More preferred is a synthetic paper obtained by molding a thermoplastic resin into a sheet. A synthetic paper obtained by molding a thermoplastic resin into a sheet can be easily formed into a thin film by a stretching treatment, and it is easy to obtain not only mechanical strength and printability but also excellent water resistance and chemical resistance. When synthetic paper formed by molding a thermoplastic resin into a sheet is used as the support 21, any of unstretched, uniaxially stretched, and biaxially stretched resin films can be used.

  Specific examples of the above-mentioned thermoplastic resins include ethylene resins (high-density polyethylene, medium-density polyethylene, low-density polyethylene, etc.), propylene-based resins, polymethyl-1-pentene, and polyolefin-based ethylene-cyclic olefin copolymers and the like. Resin: ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid copolymer metal salt (ionomer), ethylene-acrylic acid alkyl ester copolymer, Functional group-containing polyolefin resin such as ethylene-methacrylic acid alkyl ester copolymer, maleic acid modified polyethylene, maleic acid modified polypropylene; nylon-6, nylon-6,6, nylon-6,10, nylon-6,12, etc. Polyamide-based resin; thermoplastic polyester-based resin such as aromatic polyester (polyethylene terephthalate and its copolymers, polyethylene naphthalate, polybutylene terephthalate, etc.), aliphatic polyester (polybutylene succinate, polylactic acid, etc.); aromatic Polycarbonate resins such as polycarbonate and aliphatic polycarbonate; polystyrene resins such as atactic polystyrene, syndiotactic polystyrene, acrylonitrile-styrene (AS) copolymer, acrylonitrile-butadiene-styrene (ABS) copolymer; polyvinyl chloride resin And polyphenylene sulfide; and the like. These can be used alone or in combination of two or more.

  Among these, from the viewpoints of mechanical strength, physical properties, chemical properties, productivity, etc. described above, high density polyethylene, polyolefin resin such as propylene resin, functional group-containing polyolefin resin, polyester such as polyethylene terephthalate, etc. Resins are preferred. In particular, from the viewpoint of excellent balance of the above-mentioned physical properties, high-density polyethylene, propylene-based resin, propylene-based resin and high-density or low-density polyethylene are more preferable, and propylene-based resin, propylene-based resin and high density or low-density. More preferred is a mixture with a polyethylene of high density.

  The support 21 is preferably a porous support having a large number of fine pores (foam cells, voids, etc.) inside. The holes inside the support 21 can be formed by, for example, a foaming method, an internal paper-forming method, a solvent extraction method, or the like. Further, as a preferable method for producing the porous support, an internal paper-making method can be mentioned. In this internal paper-forming method, a thermoplastic resin and a resin composition obtained by mixing an inorganic filler or an organic filler that serves as a core for forming pores are formed into a sheet by a known method, and the obtained sheet is uniaxially or biaxially formed. By axially stretching, many fine holes are formed inside. Thereby, the support 21 can be whitened, opaque, and lightweight. Hereinafter, as the porous support, a synthetic paper produced by an internal paper-making method will be described as an example.

  The synthetic paper prepared by the internal paper-making method contains at least a thermoplastic resin and an inorganic filler or an organic filler that can serve as a nucleus for forming pores. The synthetic paper may be either a single layer or a laminated body in which a plurality of layers are laminated. When the synthetic paper is a laminate, the holes may be formed in only one layer, plural layers, or all layers. As a specific example of a laminate of synthetic paper, a biaxially stretched thermoplastic resin layer containing an inorganic filler or an organic filler is used as a base material layer, and at least one surface thereof is uniaxially stretched containing an inorganic filler or an organic filler. An example thereof is one in which a thermoplastic resin layer is laminated as a paper-like layer.

[Thermoplastic resin]
Specific examples of the thermoplastic resin contained in the synthetic paper are as described above, and the duplicated description here is omitted. Examples of propylene-based resins that are particularly preferably used include propylene homopolymers (homopolypropylene) that exhibit isotactic or syndiotactic and various degrees of stereoregularity; propylene as a main component, ethylene, 1- And a copolymer with an α-olefin such as butene, 1-hexene, 1-heptene, 4-methyl-1-pentene; This copolymer may be a binary system or a multi-component system of ternary or more monomer components, and may be a random copolymer or a block copolymer. Further, it is particularly preferable to use a propylene-based resin in which 2 to 25% by mass of a resin having a melting point lower than that of the propylene homopolymer is blended and used. As such a resin having a low melting point, high-density or low-density polyethylene can be exemplified.

  The content ratio of the thermoplastic resin with respect to the total amount of the synthetic paper is not particularly limited, but is preferably 25 to 100% by mass, more preferably 30 to 95% by mass, and further preferably 35 to 92% by mass in terms of solid content. And particularly preferably 45 to 90% by mass. Within the above-mentioned preferred range, suitable mechanical strength and water resistance tend to be easily obtained.

[Inorganic filler and organic filler]
The synthetic paper may contain an inorganic filler that can serve as a nucleus for forming pores as described above. By including an inorganic filler, the synthetic paper can be made white or opaque. As a result, the visibility of printing can be improved, and the printing paper can be made more suitable.

  As the inorganic filler, for example, heavy calcium carbonate, light calcium carbonate, calcined clay, talc, diatomaceous earth, titanium oxide, barium sulfate, alumina, silica, zinc oxide, magnesium oxide, clay, zeolite, mica, sericite, bentonite, Examples thereof include sepiolite, vermiculite, dolomite, wollastonite, glass fiber, and hollow glass beads, but are not particularly limited thereto. Among these, from the viewpoint of pore moldability and cost, heavy calcium carbonate, light calcium carbonate, calcined clay, and talc are preferable, and heavy calcium carbonate is more preferable.

  From the viewpoint of enhancing the dispersibility and the like, the inorganic filler may be subjected to a surface treatment, if necessary. The surface treatment method of the inorganic filler is not particularly limited. For example, JP-A-5-43815, JP-A-5-139728, JP-A-7-300568, JP-A-10-176079, JP-A-11-256144, and JP-A-11-349846, The methods described in JP 2001-158863 A, JP 2002-220547 A, JP 2002-363443 A and JP 2010-66512 A are known.

  As the surface treatment agent for the inorganic filler, higher fatty acids, polymer surfactants and the like are known, and surface treatment agents known in the art can be appropriately selected and used according to required performance. Examples of the surface treatment agent for the inorganic filler include fatty acids, organic acids, sulfate ester type anionic surfactants, sulfonic acid type anionic surfactants, resin acids or petroleum resin acids or salts thereof (for example, sodium salts and potassium salts). (Eg, alkali metal salts such as ammonium salts), antistatic agents, aluminum oxides or hydroxides, diene polymers, nonionic surfactants, inert inorganic oxides, titanate coupling agents, etc. Examples thereof include, but are not limited to, silane coupling agents, phosphoric acid coupling agents, fatty acid esters, resin acid esters, waxes, and paraffins. These can be used alone or in combination of two or more.

  Examples of the fatty acid include caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, hepnic acid, oleic acid, linoleic acid, linolenic acid, and eleostearic acid. can do. Examples of the organic acid include maleic acid and sorbic acid.

  Examples of the sulfate ester type anionic surfactant include long chain alcohol sulfate ester, polyoxyethylene alkyl ether sulfate ester, sulfated oil, and salts thereof. Examples of the sulfonic acid type anionic surfactant include alkylbenzene sulfonic acid, alkylnaphthalene sulfonic acid, paraffin sulfonic acid, α-olefin sulfonic acid, alkyl sulfosuccinic acid, and salts thereof.

  Examples of the diene polymer include polybutadiene and isoprene. Examples of nonionic surfactants include polyethylene glycol ester type surfactants. Examples of the inert inorganic oxide include alumina and silica.

  The synthetic paper may contain an organic filler that can serve as a nucleus for forming pores as described above. By containing an organic filler, the synthetic paper can be made white or opaque. As a result, the visibility of printing can be improved, and the printing paper can be made more suitable.

  The organic filler used here is a resin of a different type from the above-mentioned thermoplastic resin which is a constituent base material of the synthetic paper, and its melting point or glass transition point is the melting point or the melting point of the thermoplastic resin constituting the synthetic paper or It is preferable that the resin is higher than the glass transition point. By using such an organic filler, it is possible to increase the incompatibility of the constituent base material of the synthetic paper with the thermoplastic resin, and to improve the pore forming property during stretch molding.

  For example, when a propylene-based resin is used as a thermoplastic resin that is a constituent base material of synthetic paper, preferable organic fillers include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyamide, polycarbonate, polystyrene, and cyclic olefin homopolymer. , Ethylene-cyclic olefin copolymer, polyethylene sulfide, polyimide, polymethacrylate, polyethyl ether ketone, polyethylene sulfide, polyphenylene sulfide, melamine resin particles, which have a melting point higher than the melting point of the propylene-based resin of the constituent base material (for example, 170 ˜300° C.) or a glass transition temperature (for example, 170 to 280° C.) and is incompatible with the propylene resin of the constituent base material.

  The average particle size of the inorganic filler and the average dispersed particle size of the organic filler may be appropriately selected according to the desired performance and are not particularly limited. From the viewpoint of stable film stretching and uniform pore formation, 0.01 to 15 μm is preferable, 0.02 to 8 μm is more preferable, 0.03 to 4 μm is still more preferable, and 0.05 to 1.5 μm is particularly preferable. , And most preferably 0.1 to 1.3 μm. When the average particle size of the inorganic filler and the average dispersed particle size of the organic filler are 0.01 μm or more, voids are easily obtained during stretch molding, and opacity tends to be easily achieved. On the other hand, when the average particle diameter of the inorganic filler and the average dispersed particle diameter of the organic filler are 15 μm or less, the mechanical strength tends to be difficult to decrease.

  In the present specification, the average particle size of the inorganic fillers is obtained by observing the cut surface of the synthetic paper with an electron microscope and measuring the primary particle size of each of 100 randomly extracted inorganic fillers. Means the calculated average value. The primary particle diameter is determined from the maximum value (maximum diameter) of the distance between two points on the contour of the particle.

  Similarly, in the present specification, the average dispersed particle size of the organic filler is obtained by observing the cut surface of the synthetic paper with an electron microscope and measuring the dispersed particle size of each of 100 randomly extracted organic fillers. It means an average value calculated based on this. The dispersed particle diameter is determined from the maximum value (maximum diameter) of the distance between two points on the contour of the particle.

  The synthetic paper may contain one kind of inorganic filler alone or two or more kinds of inorganic filler in combination. Further, the synthetic paper may contain one kind of organic filler alone or two or more kinds of organic filler in combination. Further, the synthetic paper may contain one kind of inorganic filler and one or more kinds of organic filler in combination.

[Other additives]
When the synthetic paper contains at least one of the inorganic filler and the organic filler, the compounding ratio of the total amount of the inorganic filler and the organic filler (may be referred to as the addition amount of the inorganic filler and the organic filler) with respect to the total amount of the synthetic paper is particularly preferable. Although not limited, it is preferably 5 to 75% by mass, more preferably 8 to 65% by mass, and further preferably 10 to 55% by mass in terms of solid content. Within the above preferred range, voids are likely to be obtained during stretch molding, and opaqueness tends to be easily achieved. In addition, suitable mechanical strength and water resistance tend to be easily obtained.

  In addition to the above three components (thermoplastic resin, inorganic filler and organic filler), synthetic paper is a thermal stabilizer (antioxidant), light stabilizer, ultraviolet absorber, dispersant, lubricant, slip agent such as fatty acid amide. Known additives such as anti-blocking agents, kneading-type antistatic agents, dyes, pigments, plasticizers, crystal nucleating agents, release agents, and flame retardants may be included. When the composite material for offset printing is used outdoors such as poster paper, it is preferable to add an antioxidant, a light stabilizer or the like from the viewpoint of enhancing durability.

  Examples of the heat stabilizer include heat stabilizers such as sterically hindered phenolic antioxidants, phosphorus antioxidants and amine antioxidants. The amount of the heat stabilizer added is not particularly limited, but is preferably 0.001 to 1 mass% in terms of solid content with respect to the thermoplastic resin.

  Examples of the light stabilizer include a sterically hindered amine light stabilizer, a benzotriazole light stabilizer, a benzophenone light stabilizer, and a sulfur light stabilizer. The amount of the light stabilizer added is not particularly limited, but is preferably 0.001 to 1 mass% in terms of solid content with respect to the thermoplastic resin.

  The dispersant is used, for example, for the purpose of highly dispersing the inorganic filler in the film layer containing the above-mentioned thermoplastic resin. Examples of the dispersant include silane coupling agents, higher fatty acids such as oleic acid and stearic acid, metal soaps, polyacrylic acid or polymethacrylic acid, and salts thereof. The amount of the dispersant added is not particularly limited, but is preferably 0.01 to 4 mass% in terms of solid content with respect to the thermoplastic resin.

[Synthetic paper molding method]
The method for molding the synthetic paper containing the thermoplastic resin is not particularly limited. For example, various known methods such as cast molding, calender molding, roll molding, and inflation molding in which a molten thermoplastic resin is extruded into a sheet by using a single-layer or multi-layer T die or I die connected to a screw type extruder. A synthetic paper containing a thermoplastic resin can be molded by the molding method. It is also possible to mold the synthetic paper containing the thermoplastic resin by a method of casting or calendering a mixture of a thermoplastic resin and an organic solvent or oil, and then removing the solvent or oil.

[Multilayered synthetic paper]
The synthetic paper may have a single layer structure or a multilayer structure of two or more layers. When the synthetic paper has a multi-layered structure, various conventionally known methods can be used and are not particularly limited. For example, a multi-layer die method using a feed block and a multi-manifold, an extrusion lamination method using a plurality of dies, and the like can be mentioned. It is also possible to use a combination of a multilayer die and extrusion lamination.

  As a support 21 of the composite material 11 for offset printing, one of preferred modes of synthetic paper is a multilayer structure in which desired properties are given to each layer. For example, synthetic paper has a three-layer structure of surface layer/base layer/surface layer, and the base layer is provided with rigidity, opacity, lightness, etc. suitable for offset printing paper, and one surface is a surface suitable for providing the ink coating layer 31. By having a structure and the other surface layer having a surface structure suitable for providing a pressure-sensitive adhesive layer, the offset printing composite material 11 suitable as a label paper can be obtained. In addition, by forming multiple layers, it is possible to add various functions such as writability, printability, scratch resistance, and secondary processing suitability to the surface layer. Furthermore, by properly designing the composition and thickness of one surface layer and the other surface layer, curl can be controlled within a specific range even if it is in the form of offset printing paper or label paper, not to mention synthetic paper. It becomes possible to do. In addition, the synthetic paper has a multi-layer structure, and by including a concealing layer such as a solid printing layer or a pigment-containing layer in this, it imparts high opacity to offset printing paper, and printing on one side when used for poster paper etc. Can be seen through from the back, and the visibility of individual prints on both sides can be improved.

[Stretch molding of synthetic paper]
As a stretch forming method of the synthetic paper, various conventionally known methods can be used and are not particularly limited. For example, longitudinal stretching utilizing the peripheral speed difference of the roll group, transverse stretching using a tenter oven, rolling, simultaneous biaxial stretching by a combination of a tenter oven and a linear motor, simultaneous biaxial stretching by a combination of a tenter and a pantograph, or Stretching can be performed using these combinations. Also. As a stretch forming method for the blown film, a simultaneous biaxial stretching method by a tubular method can be used.

  The stretch ratio at the time of stretch-molding the synthetic paper is not particularly limited and may be appropriately determined in consideration of the characteristics of the thermoplastic resin used and the like. For example, when a propylene homopolymer or a copolymer thereof is used as the thermoplastic resin and is uniaxially stretched, the stretch ratio is preferably about 1.2 to 12 times, more preferably 2 to 10 times. In the case of stretching in the biaxial direction, the stretching ratio is preferably 1.5 to 60 times, and more preferably 10 to 50 times in terms of area ratio. When high-density polyethylene or polyethylene terephthalate is used as the thermoplastic resin and is stretched in a uniaxial direction, the stretch ratio is preferably about 1.2 to 10 times, more preferably 2 to 5 times, and in the biaxial direction. In the case of stretching, the stretching ratio is preferably 1.5 to 20 times, more preferably 4 to 12 times in terms of area ratio. Within the above preferred range, stable stretch molding can be performed, desired pores are easily obtained, and opacity tends to be improved.

  The stretching temperature at the time of stretch-molding the synthetic paper is not particularly limited, but it is preferably carried out within a temperature range suitable for stretching the thermoplastic resin as the constituent base material. For example, when the thermoplastic resin is an amorphous resin, the stretching temperature is preferably equal to or higher than the glass transition temperature of the same thermoplastic resin. Further, when the thermoplastic resin is a crystalline resin, it is preferable that the temperature is not lower than the glass transition point of the amorphous portion of the thermoplastic resin and not higher than the melting point of the crystalline portion of the thermoplastic resin. Generally, the stretching temperature of the synthetic paper is preferably 2 to 60° C. lower than the melting point of the thermoplastic resin used.

  More specifically, when the thermoplastic resin is a homopolymer of propylene (melting point 155 to 167°C), the stretching temperature is preferably 100 to 165°C. When the thermoplastic resin is high density polyethylene (melting point 121 to 136°C), the stretching temperature is preferably 70 to 134°C. Further, when the thermoplastic resin is polyethylene terephthalate (melting point 246 to 252°C), the stretching temperature is preferably 104 to 115°C. After the stretching treatment, if necessary, a heat treatment at a higher temperature may be performed.

  The stretching speed when the synthetic paper is stretch-molded is not particularly limited, but from the viewpoint of stable stretch-molding, 20-350 m/min is preferable.

  When the synthetic paper is composed of a plurality of layers, at least one of the layers is preferably stretched. When a plurality of layers are stretched, they may be stretched individually before laminating each layer, or may be collectively stretched after laminating each layer. In addition, the stretched layers may be stretched again after being laminated. One of preferred methods for producing synthetic paper includes a step of laminating a plurality of layers constituting the synthetic paper and then stretching the layers together. It tends to be simpler and cheaper in manufacturing cost, as compared with the case of stretching and laminating separately.

  When the synthetic paper is composed of a plurality of layers, the number of stretching axes of each layer constituting the synthetic paper may be unstretched or unstretched, uniaxially stretched or biaxially stretched. For example, when the synthetic paper has a three-layer structure of surface layer/base layer/surface layer, the number of stretching axes of each layer is as follows. Unstretched/uniaxial/uniaxial, unstretched/uniaxial/biaxial, unstretched/biaxial/uniaxial, unstretched/biaxial/biaxial, uniaxial/uniaxial/uniaxial, uniaxial/uniaxial/biaxial, uniaxial/biaxial/ Any combination of uniaxial, uniaxial/biaxial/biaxial, biaxial/biaxial/biaxial, etc. can be used.

[Surface treatment of synthetic paper]
Before forming the composite material 11 for offset printing by providing the ink coating layer 31 on the surface of the molded synthetic paper, it is preferable to perform surface oxidation treatment on the surface of the synthetic paper for surface modification. By applying the surface oxidation treatment, the adhesion between the synthetic paper and the ink coating layer 31 can be further improved.

  Examples of the surface oxidation treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, ozone treatment and the like. These can be performed singly or in combination of two or more. When the surface oxidation treatment is performed, it is preferable to perform the corona discharge treatment or the flame treatment because of its high effect.

[Thickness of synthetic paper]
The thickness of the synthetic paper is an element that affects the mechanical strength (for example, rigidity and tear strength) and the weight of the offset printing composite material 11. The thickness of the synthetic paper can be measured according to JIS P8118. The thickness of the synthetic paper may be appropriately set according to the desired performance and is not particularly limited, but is preferably 20 μm or more, more preferably 30 μm or more, and further preferably 50 μm or more. When the thickness of the synthetic paper is 20 μm or more, sufficient mechanical strength tends to be obtained even when the composite material for offset printing is posted outdoors as a large printed matter. On the other hand, the thickness of the synthetic paper is preferably 500 μm or less, more preferably 400 μm or less, and further preferably 300 μm or less. When the thickness of the synthetic paper is 500 μm or less, the offset printing composite material 11 does not become too heavy and tends to be easily handled.

[Porosity of synthetic paper]
When the synthetic paper has pores inside, it is easy to impart opacity and lightness as described above. The proportion of voids in the synthetic paper can be expressed by the porosity. The porosity of the synthetic paper is preferably 10% or more, more preferably 12% or more, further preferably 15% or more, and particularly preferably 20% or more, from the viewpoint of obtaining opacity. On the other hand, the porosity of the synthetic paper is preferably 45% or less, more preferably 44% or less, further preferably 42% or less, and particularly preferably 40% or less from the viewpoint of maintaining mechanical strength. ..

  The porosity of the synthetic paper can be measured by observing the cut surface of the synthetic paper with an electron microscope and determining the ratio of the area occupied by the pores in the observation region. Specifically, cut out an arbitrary part of the synthetic paper sample, embed it in epoxy resin and solidify it, then make a cut surface perpendicular to the surface direction of the synthetic paper using a microtome, and observe the cut surface Affixed to the observation sample stand so that the surface becomes a surface, vapor-deposited gold or gold-palladium, etc. on the observation surface, and cut at an arbitrary magnification (for example, a magnification of 500 to 3000 times) easy to observe with an electron microscope. The vacancy rate can be obtained by observing the vacancy on the surface, taking in the observed region as image data, and subjecting the image to image processing by an image analysis device to obtain the area ratio of the vacancy portion. In this case, the porosity can be determined by averaging the measured values obtained by observing arbitrary 10 or more points.

  Such synthetic paper is described, for example, in Japanese Patent Publication No. 46-40794, Japanese Patent Application Laid-Open No. 57-149363, Japanese Patent Application Laid-Open No. 57-181829. Further, a commercially available product (trade name: Yupo) of Yupo Corporation can be used.

[Transparent support]
Further, in applications where transparency is required, the support 21 is more preferably a transparent support. As the transparent support 21, a synthetic resin film containing a polyester resin is preferably used. Polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are preferable from the viewpoints of dimensional stability, mechanical strength, weight reduction, and the like. In particular, a stretched film, particularly a biaxially stretched polyester film is particularly preferable because it has excellent mechanical strength and dimensional stability. The transparent support 21 may have a single-layer structure made of a synthetic resin film containing a polyester resin or a multi-layer structure having two or more layers in which another synthetic resin film is laminated.

  The transparent support 21 includes a heat stabilizer (antioxidant), a light stabilizer, an ultraviolet absorber, a dispersant, a lubricant, a slip agent such as a fatty acid amide, an antiblocking agent, an antistatic agent, a dye, a pigment, Known additives such as organic or inorganic fibers, organic or inorganic fillers, plasticizers, crystal nucleating agents, release agents, flame retardants and the like may be included. When the offset printing composite material 11 is used outdoors, for example, the transparent support 21 preferably contains an antioxidant, a light stabilizer, or the like, from the viewpoint of enhancing durability.

  The transparency of the transparent support 21 is not particularly limited as long as it is optically transparent, but from the viewpoint of increasing the transparency of the composite material 11 for offset printing as a whole, the total light transmittance is preferably 85% or more, It is preferably 88% or more, more preferably 90% or more.

  The thickness of the transparent support 21 is an element that influences the mechanical strength (for example, rigidity and tear strength) and the weight of the offset printing composite material 11. The thickness of the transparent support 21 can be measured according to JIS P8118. The thickness of the transparent support 21 can be appropriately set depending on the required performance and application and is not particularly limited, but is preferably 20 μm or more, more preferably 30 μm or more, and further preferably 40 μm or more. When the thickness of the transparent support 21 is 20 μm or more, sufficient mechanical strength tends to be easily obtained even when the wet electrophotographic paper is posted outdoors as a large printed matter. On the other hand, the thickness of the transparent support 21 is preferably 500 μm or less, more preferably 400 μm or less, and further preferably 300 μm or less. When the thickness of the transparent support 21 is 500 μm or less, the offset printing composite material 11 does not become too heavy and tends to be easily handled.

[Ink layer]
The ink coating layer 31 is provided on at least one surface 21 a side of the support 21. The ink-adhering layer 31 functions as a display surface of the print medium by having ink (ink image film) attached, transferred, transferred, or the like on the surface (outermost surface) opposite to the support 21. The ink coating layer 31 contains a hydroxyl group-modified olefin adhesive and/or an acid-modified olefin adhesive having an acid value of 1 to 50 mgKOH/g as an essential component. The hydroxyl-modified olefin-based adhesive and the acid-modified olefin-based adhesive may be used alone, or the hydroxyl-modified olefin-based adhesive and the acid-modified olefin-based adhesive may be used in combination.

[Hydroxyl-modified olefin adhesive, acid-modified olefin adhesive]
The hydroxyl group-modified olefin adhesive used here is a hydroxyl group-modified product of an olefin (co)polymer containing α-olefin as a raw material. Further, acid-modified olefin adhesives, acid-modified products of olefin (co)polymers containing α-olefin as a raw material (carboxylic acid-modified products, sulfonic acid-modified products, phosphoric acid-modified products, and acid anhydrides thereof, etc. ). Here, the (co)polymer is a concept including both a homopolymer and a copolymer. The α-olefin copolymer is a copolymer of at least one α-olefin and a comonomer other than the α-olefin. That is, the hydroxyl-modified product or acid-modified product of an olefin (co)polymer means an olefin (co)polymer having a site modified with a hydroxyl group or an acid group in the molecular chain. Such a hydroxyl group-modified or acid-modified olefin adhesive has a high affinity for inks used in various printing methods, particularly liquid inks and liquid electrostatic inks, and by using these for the ink coating layer 31. The composite material 11 for offset printing having excellent ink transferability and adhesion is realized.

  Examples of the α-olefin include ethylene, propylene, butene-1, pentene-1, 2-methylbutene-1,3-methylbutene-1, hexene-1,3-methylpentene-1,4-methyl-1-pentene, and 3. , 3-dimethylbutene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpentene-1. , Ethylhexene-1, methylethylpentene-1, diethylbutene-1, propylpentene-1, decene-1, methylnonene-1, dimethyloctene-1, trimethylheptene-1, ethyloctene-1, methylethylheptene -1, diethylhexene-1, dodecene-1, tetradecene-1, hexadecene-1, octadecene-1, eicosane-1 and the like are mentioned, but are not particularly limited thereto. Among these, α-olefins having 2 to 20 carbon atoms are preferable, and α-olefins having 2 to 15 carbon atoms are more preferable. These can be used alone or in combination of two or more.

  Examples of the α-olefin copolymerization component include styrene, butadiene, acrylonitrile, vinyl chloride, vinyl bromide, hydrogenated styrene, pentadiene, cyclopentadiene and dicyclopentadiene, but are not particularly limited thereto. These can be used alone or in combination of two or more.

  Specific examples of the olefin polymer include ethylene/propylene copolymer, ethylene/butene-1 copolymer, propylene/butene-1 copolymer, propylene/butene-1/ethylene copolymer, ethylene/octene copolymer. Examples thereof include a coalesce and an ethylene/butene-1/styrene copolymer. Further, specific examples of the olefin copolymer include an olefin-styrene copolymer containing styrene and olefin such as ethylene and/or 1-butene.

  A hydroxyl group-modified product of an olefin (co)polymer can be obtained, for example, by introducing a hydroxyl group into the main chain terminal or side chain of an α-olefin (co)polymer. A method of introducing a hydroxyl group can be performed by a known method and is not particularly limited. Typically, a hydroxyl group-modified product can be obtained by (grafting) copolymerizing an olefinic (co)polymer with a hydroxyl group-containing ethylenically unsaturated compound. The hydroxyl group introduced here may be either an alcoholic hydroxyl group or a phenolic hydroxyl group, but an alcoholic hydroxyl group is preferable from the viewpoint of more excellent transferability and adhesiveness of the liquid ink.

  Examples of the hydroxyl group-containing ethylenically unsaturated compound include hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol mono(meth)acrylate, trimethylolpropane mono(meth)acrylate, tetramethylolethane mono(meth)acrylate, butanediol mono( (Meth)acrylate, (meth)acrylic acid ester such as polyethylene glycol mono(meth)acrylate, 2-(6-hydroxyhexanoyloxy)ethyl acrylate, 10-undecen-1-ol, 1-octen-3-ol, 2 -Methanol norbornene, hydroxystyrene, N-methylol acrylamide, 2-(meth)acryloyloxyethyl acid phosphate, glycerin monoallyl ether, allyl alcohol, allyloxyethanol, 2-butene-1,4-diol, glycerin monoalcohol Etc., but are not particularly limited thereto. These can be used alone or in combination of two or more.

  The amount of the hydroxyl group introduced may be appropriately set according to the amount of the hydroxyl group-modified olefin adhesive used, the ink used, etc., and is not particularly limited. For example, when the above-mentioned hydroxyl group-containing ethylenically unsaturated compound is used, the content of the olefin in the resulting copolymer is usually 0.05 to 25% by weight, preferably 1 to 10% by weight. It may be introduced into the system copolymer.

  Further, the hydroxyl value of the hydroxyl group-modified olefin adhesive is not particularly limited, but is preferably 30 to 60 mgKOH/g, more preferably 35 to 55 mgKOH/g from the viewpoint of more excellent transferability and adhesion of the liquid ink. .. The hydroxyl group-modified olefin adhesive can be used as a mixture of two or more kinds having different hydroxyl values. Examples of commercially available hydroxyl-modified olefin adhesives include Mitsui Chemicals Co., Ltd. trade names “UNISTOL P-801” and “UNISTOL P-901”. At this time, a hydroxyl group-modified olefin adhesive having a hydroxyl value of less than 30 mgKOH/g and a hydroxyl group-modified olefin adhesive having a hydroxyl value of more than 60 mgKOH/g may be mixed to adjust the amount within the above-mentioned preferred numerical range. it can.

  The copolymer of the olefin (co)polymer and the hydroxyl group-containing ethylenically unsaturated compound can be prepared by using a radical polymerization initiator in the presence of a solvent. As a method for performing graft copolymerization, for example, in the presence of a radical polymerization initiator in an inert organic solvent such as toluene, the olefinic (co)polymer and the hydroxyl group-containing ethylenically unsaturated compound are added, Examples thereof include a method of heating and stirring to cause a graft copolymerization reaction. The reaction temperature at this time is usually 50° C. or higher, preferably 80 to 200° C., and the reaction time is approximately 2 to 10 hours. The reaction system is not particularly limited and may be a batch system or a continuous system. In particular, the batch system is preferable in that the graft copolymerization can be carried out uniformly.

  Examples of the radical polymerization initiator include organic peroxides, organic peroxides such as organic peresters, and azo compounds such as azobisisobutyronitrile and dimethylazoisobutyronitrile, but are not particularly limited to these. Not done. Among these, organic peroxides and organic peresters are particularly preferably used. Specific examples of the organic peroxide or organic perester include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butylperacetate, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl- 2,5-di(tert-butyl peroxide) hexane, tert-butyl benzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpiperate, cumyl Examples include perpiperate and tert-butyl perdiethyl acetate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di(tert- Dialkyl peroxides such as butylperoxy)hexane and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferred.

  The organic solvent used for the copolymerization or graft copolymerization reaction is not particularly limited. Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane, heptane, octane and decane; alicyclic hydrocarbons such as cyclohexane, cyclohexene and methylcyclohexane; ethanol, Aliphatic alcohols such as isopropanol; ketone solvents such as acetone, methyl isobutyl ketone, and methyl ethyl ketone; halogenated hydrocarbons such as trichloroethylene, trichloroethane, dichloroethylene, and chlorobenzene; and the like, but are not particularly limited to these. Not done. These can be used alone or in combination of two or more. Among these, aromatic hydrocarbons are preferable, and alkyl-substituted aromatic hydrocarbons are particularly preferable.

  The amount of the hydroxyl group-modified olefin adhesive used may be appropriately set according to the desired performance and is not particularly limited. From the viewpoint of adhesion to ink, printability, etc., the solid content is preferably 30 to 80% by mass, and more preferably 32 to 75% by mass, based on the total amount of the ink coating layer 31.

  The acid modified product of the olefin (co)polymer can be obtained, for example, by introducing an acid group into the main chain terminal or side chain of the α-olefin (co)polymer. The acid group introduced here is not particularly limited, and may be, for example, any of a carboxyl group, a sulfonic acid group, a phosphoric acid group, and an acid anhydride group thereof, but the transferability and adhesion of the liquid ink A carboxyl group and a carboxylic acid anhydride group are preferable because they are more excellent. In the modified olefin-based adhesive of the present specification, the modified product with a phenolic hydroxyl group corresponds to the above-mentioned hydroxyl-modified olefin-based adhesive and does not correspond to the acid-modified olefin-based adhesive. The method for introducing the acid group can be performed by a known method and is not particularly limited. For example, by (grafting) copolymerizing an olefinic (co)polymer with a carboxylic acid group-containing ethylenically unsaturated compound such as acrylic acid or methacrylic acid, or a carboxylic acid anhydride such as maleic anhydride, A carboxylic acid modified product can be obtained. Further, (grafting) copolymerization of an olefinic (co)polymer with an unsaturated carboxylic acid ester such as methyl acrylate or ethyl methacrylate, or an unsaturated carboxylic acid amide such as methacrylamide or maleic acid diamide. A carboxylic acid modified product can also be obtained by

  Examples of the carboxylic acid group-containing ethylenically unsaturated compound include, but are not limited to, acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. These can be used alone or in combination of two or more. Further, examples of the carboxylic acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, citraconic anhydride, and the like, but are not particularly limited thereto. For these introduction methods, radical polymerization and graft polymerization in the above-mentioned hydroxyl group-modified olefin adhesive can be applied, and duplicate explanations are omitted here.

  The amount of the acid group introduced may be appropriately set according to the amount of the acid-modified olefin adhesive used, the ink used, and the like, and is not particularly limited. For example, when using the above-mentioned carboxylic acid group-containing ethylenically unsaturated compound or carboxylic acid anhydride, the content in the obtained copolymer is usually 0.05 to 25% by mass, preferably 0.1 to 10%. It may be introduced into the olefin-based copolymer in an amount of 1% by mass, more preferably 1 to 5% by mass.

  The acid value of the acid-modified olefin-based adhesive is not particularly limited, but is preferably 1 to 50 mgKOH/g, more preferably 3 to 40 mgKOH/g, from the viewpoint of more excellent transferability and adhesion of the liquid ink. It is preferably 5 to 30 mgKOH/g. Examples of commercially available acid-modified olefin adhesives include, for example, Mitsubishi Chemical Co., Ltd., trade names “Surflen P-1000”, “Admer OF551”, and “Admer NF550”; trade name “Modic S525” manufactured by Mitsubishi Plastics Co., Ltd. Etc. The acid-modified olefin adhesive can be used as a mixture of two or more kinds having different acid values. At this time, the acid-modified olefin-based adhesive having an acid value of less than 50 mgKOH/g and the acid-modified olefin-based adhesive having an acid value of more than 50 mgKOH/g can be mixed and adjusted within the above-mentioned preferred numerical range. ..

  The content of the hydroxyl group-modified olefin-based adhesive and the acid-modified olefin-based adhesive in the ink coating layer 31 may be appropriately set according to the desired performance and is not particularly limited. From the viewpoint of the balance between ink adhesion, printability, etc. and blocking resistance, the total amount is preferably 50 to 98% by mass, more preferably 60 to 95% by mass in terms of solid content with respect to the total amount of the ink-adhering layer 31. And more preferably 70 to 90% by mass.

  In addition, from the viewpoint of making blocking resistance, hiding property, printing property, chromaticity, hue, and the like, in which the ink is less likely to be peeled off when the media are overlapped, the ink coating layer 31 is a hydroxyl group. In addition to the modified olefin-based adhesive and/or the acid-modified olefin-based adhesive, it is preferable to include a white pigment or a urethane-based resin. On the other hand, from the viewpoint of suppressing the stickiness after film formation and increasing the blocking resistance when the offset printing composite material 11 is superposed without excessively impairing the transparency of the ink coating layer 31, the ink coating layer 31 The layer 31 preferably contains a polyisocyanate compound in addition to the hydroxyl group-modified olefin adhesive and/or the acid-modified olefin adhesive. Hereinafter, each of these components will be described in detail.

[White pigment]
As the white pigment, various known pigments can be used and are not particularly limited. By using the white pigment in combination, the hiding property can be improved and the transparency of the ink coating layer 31 can be reduced. In addition, whiteness and hue can be improved by using a white pigment together. Considering the hiding property required for printing paper, titanium oxide, barium sulfate, calcium sulfate, and zinc oxide are preferably used. In particular, titanium oxide is particularly preferably used because it has a high hiding property and is excellent in whiteness and hue. As the titanium oxide, any of rutile type (tetragonal high temperature type), anatase type (tetragonal low temperature type) and brookite type (orthorhombic type) may be used. As various commercially available products, for example, titanium oxide particles (trade name: Taipaque) manufactured by Ishihara Sangyo Kaisha, Ltd. are available. Titanium oxide is generally produced by the sulfuric acid method and the chlorine method, but from the viewpoint of whiteness, the pigment produced by the chlorine method is preferable because the whiteness is high and excellent. As the titanium oxide, surface-modified titanium oxide that has been subjected to alumina surface treatment or silica surface treatment can be used.

  The average particle diameter of the white pigment (in the case of forming aggregates, the particle diameter of the aggregates, so-called secondary particle diameter) is pigment dispersibility, hiding power, suppression of coarse projection formation, printing characteristics, chromaticity and It may be appropriately set according to desired performance such as hue, and is not particularly limited. For example, in the case of titanium oxide, the thickness is preferably 0.01 to 1 μm, more preferably 0.1 to 0.5 μm. The average particle diameter referred to here means a so-called median diameter D50. The median diameter D50 can be measured by a known laser diffraction/scattering type particle size distribution measuring device.

  Further, the content ratio of the white pigment may be appropriately set according to the desired performance for the same reason as above, and is not particularly limited. From the viewpoints of whiteness, hiding power, adhesiveness with the support 21, adhesiveness with ink, suppression of formation of coarse protrusions, etc., 5 to 40% by mass is preferable in terms of solid content with respect to the total amount of the ink coating layer 31, More preferably, it is 10 to 35 mass %.

[Urethane resin]
The urethane resin is a compound obtained by copolymerizing a polyol compound and a diisocyanate compound by a condensation reaction. The urethane-based resin has a large number of highly polar groups such as urethane bonds in its molecule, and has excellent adhesiveness to various thermoplastic resins due to its intermolecular force. Although it depends on the amount of the hydroxyl group-modified olefin-based adhesive used and the like, the combined use of the urethane-based resin tends to reduce stickiness and enhance blocking resistance. Further, by using the urethane type resin together, the adhesion with the support 21 tends to be improved. Furthermore, when a white pigment is used in combination, the urethane resin also contributes to the retention and fixation of the white pigment as a dispersion matrix.

  The urethane resin blended in the ink coating layer 31 is not particularly limited, but is preferably solvent-dispersible or solvent-soluble in order to easily form the ink coating layer 31. Specifically, a urethane resin having an average molecular weight of 10,000 to 300,000 is preferable, and a urethane resin having an average molecular weight of 50,000 to 200,000 is more preferable. The urethane-based resin having such characteristics is suitable for coating applications and ink applications.

  The urethane resin can be manufactured by a conventionally known method, and the manufacturing method is not particularly limited. For example, JP-A-62-153366, JP-A-62-153367, JP-A-1-236289, JP-A-2-64173, JP-A-2-64174, and JP-A-2-64175. It can be obtained by the method disclosed in the official gazette. Specifically, a polyol compound and a diisocyanate compound are mixed in a ratio such that the amount of the isocyanate group is in excess, in a suitable solvent, for example, usually used as a solvent for non-toluene gravure ink, ethyl acetate, propyl acetate , Ester solvents such as butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, isopropyl alcohol, n-butanol; hydrocarbon solvents such as methylcyclohexane and ethylcyclohexane; Alternatively, a two-step method in which a prepolymer having an isocyanate group at the terminal is prepared by a condensation reaction in these mixed solvents and then a chain extender or a reaction terminator is reacted therewith may be mentioned. Alternatively, a one-step method in which a polyol compound, a diisocyanate compound, and a chain extender are reacted at once in the appropriate solvent described above can be mentioned. The two-step method is preferable because the molecular weight is easily adjusted and a uniform polymer solution is easily obtained.

  As the polyol compound used for synthesizing the urethane resin, various known polyol compounds generally used for the production of urethane resin can be used. Examples of the polyol compound include polymer or copolymer polyether polyols (1) such as methylene oxide, ethylene oxide and tetrahydrofuran; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2- Methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1 ,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2, Saturated or unsaturated low-molecular-weight polyols (2) such as 6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaesthritol; these low-molecular weight polyols (2), adipic acid, phthalic acid Polycarboxylic acids such as acids, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, trimellitic acid, and pyromellitic acid. Polyester polyols (3) obtained by dehydration condensation or polymerization with an acid or an anhydride thereof; cyclic ester compounds such as lactones such as polycaprolactone, polyvalerolactone and poly(β-methyl-γ-valerolactone) Polyester polyols (4) obtained by ring-opening polymerization of;, Polycarbonate polyols (5) obtained by reacting the low molecular weight polyols (2) and the like with dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene and the like. ); Polybutadiene glycols (6); Glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A (7); one or more hydroxyethyl, hydroxypropyl acrylate, acrylhydroxybutyl, etc. in one molecule. Alternatively, an acrylic polyol (8) obtained by copolymerizing the corresponding methacrylic acid derivative or the like with acrylic acid, methacrylic acid or an ester thereof, for example, is not particularly limited. These may be used alone or in combination of two or more. In addition, among the polyester polyols (3), a polymer diol obtained from a diol (glycol) and a dibasic acid is a low molecular weight compound having 5 or more mol% of the diol and three or more hydroxyl groups. It can be substituted with a polyol (2).

  As the diisocyanate compound used for synthesizing the urethane-based resin, various known aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates and the like generally used for the production of urethane-based resins can be used. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, m-tetramethylxylylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, butane-1,4-diisocyanate, hexamethylene Diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'- Examples thereof include diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, and dimerisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group, but are not particularly limited thereto. These may be used alone or in combination of two or more.

  Examples of the chain extender used for synthesizing the urethane-based resin include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and the like, 2- Hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyropyrethylenediamine, di Examples thereof include amines having a hydroxyl group in the molecule such as 2-hydroxypyropyrethylenediamine and di-2-hydroxypropylethylenediamine, but are not particularly limited thereto. These can be used alone or in combination of two or more.

  As the reaction terminator for the purpose of stopping the reaction, for example, a monovalent active hydrogen-containing compound can be used. Specific examples thereof include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol, but are not particularly limited thereto. When it is desired to introduce a carboxyl group into the polyurethane resin, amino acids such as glycine and L-alanine can be used as the reaction terminator. These can be used alone or in combination of two or more.

  The amount of the urethane resin used may be appropriately set according to the desired performance and is not particularly limited. From the viewpoint of adhesion with the support 12, blocking resistance, and the like, it is preferably 5 to 40% by mass, and more preferably 7 to 35% by mass in terms of solid content based on the total amount of the ink coating layer 31.

[Polyisocyanate compound]
The polyisocyanate compound is a polyfunctional polyisocyanate compound having at least two isocyanate groups in the molecule. The polyisocyanate compound is used in combination with the above-mentioned hydroxyl group-modified or acid-modified olefin-based adhesive, although it depends on the amount of the hydroxyl-modified olefin-based adhesive or acid-modified olefin-based adhesive used. There is a tendency that, without excessively impairing the transparency of 31, the stickiness after film formation is suppressed and the blocking resistance when the offset printing composite material 11 is superposed is increased.

The polyisocyanate compounds are roughly classified into aliphatic polyisocyanates, aromatic polyisocyanates, alicyclic polyisocyanates and the like. As the aromatic polyisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene Examples thereof include diisocyanate, diphenyl diisocyanate, polymethylene polyphenylene polyisocyanate, 1,5-naphthylene diisocyanate, diphenyl ether diisocyanate, and triphenylmethane triisocyanate, but are not particularly limited thereto.
Examples of the aliphatic polyisocyanate include propylene diisocyanate, isopropylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate. Etc., but are not particularly limited thereto.
As the alicyclic polyisocyanate, cyclohexane diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, isophorone diisocyanate, 2,2,4-trimethylhexahexane Examples thereof include methylene diisocyanate and dimeryl diisocyanate, but are not particularly limited thereto. These can be used alone or in combination of two or more.

  The content of the polyisocyanate compound in the ink coating layer 31 may be appropriately set depending on the desired performance and is not particularly limited. From the viewpoint of the balance between blocking resistance, ink adhesion, printability, etc., the solid content is preferably 2 to 45% by mass, more preferably 5 to 35% by mass, based on the total amount of the ink coating layer 31. More preferably, it is 7 to 30 mass %.

[Anti-blocking agent]
When a polyisocyanate compound is used, the ink coating layer 31 may further contain an antiblocking agent. The combined use of the anti-blocking agent tends to further improve the blocking resistance when the offset printing composite material 11 is superposed. As the anti-blocking agent used here, known anti-blocking agents such as silica fine particles such as aggregated silica and spherical silica, polymer beads and the like can be used and are not particularly limited. Among these, polymer beads are preferable from the viewpoints of homogeneity as an anti-blocking agent, detachment from the ink coating layer 31, transparency of the ink coating layer 31, and the like.

  Examples of the polymer beads include fine particles such as styrene resin, (meth)acrylic resin, polycarbonate resin, polyester resin, ethylene resin, propylene resin, and fluorine resin, but are not particularly limited thereto. In particular, from the viewpoints of miscibility when used in combination with a hydroxyl group-modified olefin adhesive or an acid-modified olefin adhesive, a difference in refractive index with these adhesives, and the like, (meth)acrylic resins and polyester resins are preferable, A meth)acrylic resin is more preferable. Among the (meth)acrylic resins, fine particles of crosslinked or uncrosslinked (meth)acrylic resin are particularly preferable. In the present specification, the (meth)acrylic resin includes both acrylic resin and methacrylic resin.

  The average particle size of the antiblocking agent may be appropriately set according to the desired performance, and is not particularly limited. From the viewpoint of the balance between blocking resistance and ink adhesion, printability, etc., 0.1 to 10.0 μm is preferable, 0.5 to 8.0 μm is more preferable, and 1.0 to 6. It is 0 μm. In addition, in this specification, the average particle diameter of the anti-blocking agent means a so-called median diameter D50 obtained by a laser diffraction/scattering method. This average particle diameter can be measured by a known laser diffraction/scattering type particle size distribution measuring device.

  The content of the anti-blocking agent in the ink coating layer 31 may be appropriately set according to the desired performance and is not particularly limited. From the viewpoint of dispersibility, light scattering and the like, the solid content is preferably 0.05 to 10% by mass, more preferably 0.1 to 8.0% by mass, and still more preferably the solid content based on the total amount of the ink coating layer 31. It is 0.2 to 5.0 mass %.

[Auxiliary agent]
In addition to the above-mentioned hydroxyl group-modified olefin-based adhesive, acid-modified olefin-based adhesive, white pigment or urethane-based resin, polyisocyanate compound, anti-blocking agent, the ink-adhering layer 31 may have printability as necessary. Various auxiliaries known in the art may be contained within a range that does not significantly impair the above. Examples of the auxiliaries include heat stabilizers (antioxidants), light stabilizers, dispersants, ink adsorbents, antistatic agents, ultraviolet absorbers, dyes, pigments, plasticizers, release agents, flame retardants, and inks. Examples thereof include adsorbents, antistatic agents, light stabilizers (ultraviolet stabilizers), leveling agents, etc., but are not particularly limited thereto. When the offset printing composite material 11 is used outdoors, such as poster paper, it is preferable that it contains an antioxidant, a light stabilizer, or the like, from the viewpoint of enhancing durability.

  Examples of the heat stabilizer include heat stabilizers such as sterically hindered phenolic antioxidants, phosphorus antioxidants and amine antioxidants. The amount of the heat stabilizer added is not particularly limited, but is preferably 0.001 to 1 mass% in terms of solid content with respect to the thermoplastic resin.

  Examples of the light stabilizer include a sterically hindered amine light stabilizer, a benzotriazole light stabilizer, a benzophenone light stabilizer, and a sulfur light stabilizer. The amount of the light stabilizer added is not particularly limited, but is preferably 0.001 to 1 mass% in terms of solid content with respect to the thermoplastic resin.

  The dispersant is used, for example, for the purpose of highly dispersing the inorganic filler in the film layer containing the above-mentioned thermoplastic resin. Examples of the dispersant include silane coupling agents, higher fatty acids such as oleic acid and stearic acid, metal soaps, polyacrylic acid or polymethacrylic acid, and salts thereof. The amount of the dispersant added is not particularly limited, but is preferably 0.01 to 4 mass% in terms of solid content with respect to the thermoplastic resin.

[Formation method of ink coating layer]
The method for forming the ink coating layer 31 is not particularly limited, but a step of dissolving the above-mentioned components constituting the ink coating layer 31 in a solvent to prepare a coating liquid, and the prepared coating liquid The ink coating layer 31 is formed by a method including a step of coating the coating solution on at least one surface (the surface 21a in FIG. 1) of the support 21 and a step of drying and solidifying the coated coating solution. It is preferably formed. At this time, various primer layers and adhesive layers may be provided on the surface of the support 21, and the ink coating layer 31 may be provided on these layers. Thereby, the composite material 11 for offset printing can also be manufactured by roll-to-roll, and productivity can be improved. In addition, by drying and solidifying the coating liquid in this manner, an ink coating layer 31 having excellent ink adhesion and blocking resistance can be easily obtained while maintaining relatively transparency in applications where transparency is required. There is a tendency. Furthermore, since the thickness of the ink coating layer 31 can be adjusted relatively easily, the thickness of the coating layer can be adjusted while maintaining the printability, and the desired whiteness and texture of the composite for offset printing can be obtained. The material 11 can be manufactured. The conditions for the drying and solidification can be appropriately set depending on the materials to be used, the compounding amount, the desired transparency, the ink adhesion, the blocking resistance, etc., and are not particularly limited, but from the viewpoint of productivity, etc., 30 ˜70° C., preferably about 1 second to 30 minutes.

  The formation of the ink coating layer 31 may be performed together with the molding of the support 21 in the molding line, or may be performed in a line separate from the molding of the support 21. Further, for example, when the coating liquid is applied onto the support 21, a die coater, bar coater, roll coater, lip coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater or the like is applied. A device can be used.

  The solvent used when preparing the coating liquid is not particularly limited, but is preferably an organic solvent. For example, ester solvents such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; alcohol solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butanol; Examples thereof include hydrocarbon solvents such as cyclohexane, methylcyclohexane and ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; or mixed solvents thereof, but are not particularly limited thereto. These can be used alone or in combination of two or more.

  The solid content concentration of the coating liquid may be appropriately set in consideration of the coating device used, handleability, productivity, etc., and is not particularly limited, but is 5 to 40% by mass with respect to the total amount of the coating liquid. Is preferable, and more preferably 10 to 35% by mass.

[Coating amount]
The coating amount of the ink coating layer 31 may be appropriately set in consideration of film-forming properties (coating unevenness), productivity, adhesiveness with the support 21 used, adhesiveness with the ink used, and the like. Good. The coating amount of the ink coating layer 31 is preferably 0.5 to 10 g/m ^{2 on} one side, more preferably 0.6 to 8.0 g/m ² , and further preferably 0 in terms of solid content after drying. It is 0.7 to 5.0 g/m ² .

  It is preferable that the support 21 is subjected to a surface oxidation treatment and surface modification prior to the film formation of the ink coating layer 31. By applying the surface oxidation treatment, the adhesion between the support 21 and the ink coating layer 31 can be further improved. Examples of the surface oxidation treatment include corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment, ozone treatment and the like. These can be performed singly or in combination of two or more. When the surface oxidation treatment is performed, it is preferable to perform the corona discharge treatment or the flame treatment because of its high effect.

When the corona discharge treatment is carried out, the treatment amount is not particularly limited, but preferably 600 J/m ² (10 W·min/m ² ) or more, more preferably 1,200 J/m ² (20 W·min/m ^{2 ).} ) Or more, and preferably 12,000 J/m ² (200 W·min/m ² ) or less, more preferably 10,800 J/m ² (180 W·min/m ² ) or less. When performing frame processing, the processing amount is not particularly limited, preferably 8,000J / ^{m 2} or more, more preferably 20,000J / ^{m 2} or more, and preferably 200,000 J / ^{m 2} Or less, more preferably 100,000 J/m ² or less.

[ink]
The type of ink attached (or transferred, transferred, etc.) to the ink coating layer 31 is not particularly limited. Not only the ink for offset printing, but also ink for ink jet recording, powder toner for electrophotography, etc. are applicable. In particular, the offset printing composite material 11 employs the ink-adhering layer 31 having excellent ink transferability and adhesiveness, and thus is much finer than the conventional one, for example, having an average particle diameter of 0.5 to 4 μm. When a liquid electrostatic ink containing the ink particles (typically, an electro ink manufactured by Hewlett-Packard) is used, the effect of improving the transferability and adhesiveness of the ink becomes apparent. This is because the transfer leakage of the ink and the dropout of the ink are likely to occur as the ink particles become ultrafine. Therefore, from this point of view, the offset printing composite material 11 of the embodiment is offset printing using a liquid ink containing ink particles having an average particle size of 0.5 to 4 μm, more preferably an average particle size of 1 to 2 μm. It can be said to be particularly useful in digital offset printing using a liquid electro ink containing the above ink particles.

[Adhesive layer]
Note that the offset printing composite material 11 can take the form of the pressure-sensitive adhesive sheet 51 that can be attached to an adherend by providing the pressure-sensitive adhesive layer 41 on one surface of the outermost layer thereof. For example, as shown in FIG. 2, by providing the pressure-sensitive adhesive layer 41 on the surface (front surface 21b) of the support 21 opposite to the surface (front surface 21a) on which the ink coating layer 31 is provided, the ink coating layer is formed. The pressure sensitive adhesive sheet 51 in which 31, the support 21, and the pressure sensitive adhesive layer 41 are laminated in this order can be used.

  The pressure-sensitive adhesive layer 41 can be formed by, for example, applying a solvent-based or water-based pressure-sensitive adhesive that is generally used, and performing a smoothing step and a drying step as necessary. The kind of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 41 and the thickness (coating amount) of the pressure-sensitive adhesive layer 41 can be variously selected according to the type of the adherend, the usage environment, the adhesive strength, and the like. As the adhesive, for example, a synthetic polymer adhesive such as a natural rubber type, a synthetic rubber type, or an acrylic type can be used. When the pressure-sensitive adhesive is applied, it may be used in the form of a solution dissolved in an organic solvent, a dispersion dispersed in an aqueous solvent, an emulsion or the like, if necessary. Further, in order to improve the opacity of the offset printing composite material 11, the adhesive may contain a pigment such as titanium white.

  Further, the pressure-sensitive adhesive layer 41 may be formed by applying it on a silicone-treated surface of a release sheet or process paper in a solution state, and then transferring this onto the composite material 11 for offset printing. Alternatively, it may be formed by directly coating the composite material 11 for offset printing. The pressure-sensitive adhesive can be coated by using a known coating device such as a die coater, a bar coater, a roll coater, a lip coater, a gravure coater, a spray coater, a blade coater, a reverse coater, and an air knife coater. The thickness of the pressure-sensitive adhesive layer can be appropriately set and is not particularly limited, but is usually preferably 2 to 30 μm, more preferably 5 to 20 μm.

[Release sheet]
A release sheet may be further provided on the surface 41a of the pressure-sensitive adhesive layer 41 described above. By providing the release sheet, the pressure-sensitive adhesive layer 41 can be protected when not in use. It is also possible to leave the release sheet provided at the time of offset printing and remove the release sheet when attaching to an adherend. As the release sheet, those known in the art can be used, and the type thereof is not particularly limited. For example, high-quality paper or kraft paper can be used as it is, or can be calendered, resin-coated or film-laminated, glassine paper, coated paper, plastic film, or the like subjected to silicone treatment. The release sheet used here has a silicone treatment on the surface in contact with the pressure-sensitive adhesive layer 41 in order to improve the releasability from the pressure-sensitive adhesive layer 41 when used by being stuck to the offset printing composite material 11. Is common.

[Postcard application]
On the other hand, the composite material 11 for offset printing and the adhesive sheet 51 are attached to a recording paper 61 such as a postcard-sized synthetic paper, pulp paper, or inkjet recording paper to form a postcard 71 (an inkjet recording postcard, a postcard with a photo, etc.). ) Can be adopted. For example, as shown in FIG. 3, a pressure-sensitive adhesive layer 41 is provided on the surface (front surface 21b) of the support 21 opposite to the surface (front surface 21a) on which the ink coating layer 31 is provided. By sticking the recording paper 61 on the surface 41a, a postcard 71 can be obtained in which the ink-adhering layer 31, the support 21, the adhesive layer 41, and the recording paper 61 are laminated in this order.

[Opacity]
In opaque printing applications such as the above postcards, the opacity of the offset printing composite material 11 is preferably 93% or more, more preferably 95% or more, and further preferably 97% or more. This is for the following reason. That is, the offset printing composite material 11 is used for various purposes by printing and/or printing various information by the ink adhering to the surface of the ink coating layer 31. For this reason, it is desirable that the characters and the like printed and/or printed on the offset printing composite material 11 can be read regardless of the background of the offset printing composite material 11. If the opacity of the composite material 11 for offset printing is 93% or more, the background cannot be seen through, and the legibility of characters printed on the printed surface tends to be improved. Then, for example, when the offset printing composite material 11 is attached to a postcard or the like, it is possible to prevent the impurities and the roughness of the postcard from being seen through. Here, in the present specification, "opacity" is measured in accordance with "paper and board-opacity test method (paper backing)-diffuse illumination method" defined in JIS P8149:2000. Means a value.

[Whiteness]
At this time, the whiteness of the composite material 11 for offset printing is preferably 80% or more, and more preferably 90% or more. When the whiteness of the composite material 11 for offset printing is 80% or more, the visibility of the printed content printed on the surface of the ink coating layer 31 tends to be improved. Here, in the present specification, the “whiteness” is L measured according to “Hunter Method of Whiteness (C Method)” defined in JIS L1015:1999, using a Hunter color difference meter. , A, b values. As the Hunter color difference meter, for example, SM color meter SM-T manufactured by Suga Test Instruments Co., Ltd. can be used.

[Hue]
As the hue of the composite material 11 for offset printing, it is preferable that L is 85 to 100, a is -10 to +10, and b is -15 to +7. Here, L, a, and b are the lightness index L and the chromaticness index a and b displayed by the method of displaying the color of the Hunter color system defined in JIS-Z8730:2009. Each parameter can be measured by the Hunter color difference meter used for measuring the whiteness. L is more preferably 87 to 99, and even more preferably 90 to 98. Further, a is more preferably -7 to +7, and further preferably -5 to +5. Further, b is more preferably -10 to +5, further preferably -7 to +3. Within the preferable numerical range, the whiteness of photographic paper is obtained, and the visibility of printed contents tends to be improved.

[Window film use]
The offset printing composite material 11 can be in the form of a window film that can be attached to an adherend by providing an adhesive layer on one surface of the outermost layer thereof. For example, by providing an adhesive layer on the surface of the transparent support 21 opposite to the surface (front surface 21a) on which the ink application layer 31 is provided (see FIG. 2), the ink application layer 31, the transparent support 21 and a pressure-sensitive adhesive layer may be laminated in this order to form a window film. The pressure-sensitive adhesive layer used here is not particularly limited, and the same one as the pressure-sensitive adhesive layer 41 described above can be used. Further, the release sheet described above may be further provided on the surface (exposed surface) of the pressure-sensitive adhesive layer described above. By providing the release sheet, the pressure-sensitive adhesive layer can be protected when not in use.

[Opacity]
In the transparent printing application such as the window film described above, the opacity of the composite material 11 for offset printing is preferably 10% or less, more preferably 8% or less, and further preferably 6% or less. When the opacity of the composite material 11 for offset printing is 10% or less, light transmission is not excessively hindered when used as a window film or the like, and various color variations and graphic expressions can be easily realized. .. Here, in the present specification, "opacity" is measured in accordance with "paper and paperboard-opacity test method (paper backing)-diffuse illumination method" defined in JIS P8149:2000. Means a value.

  In addition, as one of the preferable modes in applications where transparency is required, it is preferable that the ink coating layer 31 does not substantially contain an inorganic filler. Here, “not substantially containing” means that the content of the inorganic filler is 0.0 to 3.0 mass% in terms of solid content with respect to the total amount of the ink coating layer 31. The content is more preferably 0.0 to 1.0% by mass, further preferably 0.0 to 0.5% by mass, and particularly preferably 0.0 to 0.01% by mass. When at least one of the hydroxyl group-modified olefin adhesive and the modified olefin adhesive is used in combination with the polyisocyanate compound, the transferability and adhesion of the ink and the transparency are excellent even in the inorganic filler-less aspect, Furthermore, the offset printing composite material 11 having blocking resistance suitable as a printing medium for offset printing can be realized.

  Hereinafter, the present invention will be specifically described with reference to Preparation Examples and Examples. The materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the present invention is not limited to the following examples.

(Manufacture of support)
[Production Example A1 of Support]
Propylene homopolymer (trade name "Novatech PP MA-8", melting point: 164°C, manufactured by Nippon Polypro) 67% by mass, high-density polyethylene (trade name "Novatech HD HJ580", melting point: 134°C, manufactured by Nippon Polyethylene Co., Ltd. ) A resin composition (a) containing 10% by mass and 23% by mass of calcium carbonate powder having an average particle diameter of 1.5 μm is melt-kneaded at 260° C. using an extruder and extruded in a film form from a die to obtain 50 The film was cooled to °C. This film was heated again to 140° C., and then stretched 5 times in the machine direction by utilizing the peripheral speed difference of the roll group to obtain a uniaxially stretched film as a base layer.
On the other hand, propylene homopolymer (commercial name "Novatech PP MA-3", manufactured by Japan Polypro) 51.5% by mass, high-density polyethylene (commercial name "Novatech HD HJ580", manufactured by Japan Polyethylene Co., Ltd.) 3.5% by mass The resin composition (b) containing 42% by mass of calcium carbonate powder having an average particle size of 1.5 μm and 3% by mass of titanium oxide powder having an average particle size of 0.8 μm is used by another two extruders. The mixture was melt-kneaded at 250° C. and extruded on both sides of the uniaxially stretched film in a film form from a die and laminated to obtain a laminate (b/a/b) having a three-layer structure of surface layer/base layer/surface layer. ..
This three-layer laminate was introduced into a tenter oven, heated to 155°C, stretched in the transverse direction 8 times using a tenter, then heat set (annealed) at 164°C, and further cooled to 55°C. The ears were slit to obtain a thermoplastic resin film having a thickness of 110 μm, which was used as a support. The porosity of the support was 34%.

[Support Production Example A2]
The resin composition (a) of Production Example 1 was melt-kneaded at 260° C. using an extruder, extruded into a film form from a die, and the film was cooled to 50° C. This film was heated again to 140° C., and then stretched 5 times in the longitudinal direction and 8 times in the transverse direction by utilizing the peripheral speed difference of the rolls to obtain a single-layer structure having only the base layer of the resin composition (a). A biaxially stretched film having
This biaxially stretched film was heat set at 164° C. in the same manner as in Production Example 1, further cooled to 55° C., the ears were slit, and a thermoplastic resin film having a thickness of 80 μm was obtained, which was used as a support. And The porosity of the support was 40%.

[Production Example A3 of Support]
Instead of the resin composition (a), 87% by mass of propylene homopolymer (trade name "Novatech PP MA-8", melting point 164°C, manufactured by Nippon Polypro), high-density polyethylene (trade name "Novatech HD HJ580", A biaxially stretched thermoplastic resin film having a thickness of 50 μm is obtained in the same manner as in Production Example 2 except that a resin composition containing 13% by mass of a melting point of 134° C., manufactured by Japan Polyethylene Corporation) is used. It was used as a support. The porosity of the support was 0%.

[Example A4 of support]
A commercially available biaxially stretched PET film (trade name “E5200”, thickness 75 μm, manufactured by Toyobo Co., Ltd.) was used as a transparent support containing a polyester resin.

[Preparation Example A1]
12 parts by mass of toluene and 20 parts by mass of methyl ethyl ketone are mixed, and in this mixed solvent, 50 parts by mass of an adhesive (a product name "UNISTOL P-801", manufactured by Mitsui Chemicals, Inc.) containing a hydroxyl group-modified product of an olefin copolymer. Was added and mixed by a dissolver to obtain a coating liquid for the ink adhered layer.

[Preparation Example A2]
Silica (trade name "Sylysia 350", manufactured by Fuji Silysia Chemical Ltd.) 4.4 parts by mass, polyurethane resin (trade name "TA24-412A", manufactured by Hitachi Chemical Co., Ltd.) 19 parts by mass, toluene 12 parts by mass, methyl ethyl ketone 20 parts by mass Parts by a dissolver, and 50 parts by mass of an adhesive (trade name "UNISTOL P-801", manufactured by Mitsui Chemicals, Inc.) containing a hydroxyl-modified product of an olefinic copolymer is added to the mixed solution, and the dissolver is added. And mixed to obtain a coating liquid for the ink-coated layer.

[Preparation Example A3]
4.2 parts by mass of titanium dioxide (trade name "CR-67", manufactured by Ishihara Sangyo Co., Ltd.), 2.5 parts by mass of silica (trade name "Sylysia 350", manufactured by Fuji Silysia Chemical Ltd.), polyurethane resin (trade name "TA24-412A" (manufactured by Hitachi Chemical Co., Ltd.) 12 parts by mass, toluene 12 parts by mass, and methyl ethyl ketone 20 parts by mass were mixed by a dissolver and then dispersed by a sand mill to obtain 50 parts by mass of a pigment dispersion. To this pigment dispersion, 50 parts by mass of an adhesive (a product name “UNISTOL P-801”, manufactured by Mitsui Chemicals, Inc.) containing a hydroxyl-modified product of an olefin-based copolymer was added, mixed with a dissolver, and ink was applied. A layer coating solution was obtained.

[Preparation Example A4]
13.3 parts by mass of polyurethane resin (trade name "TA24-412A", manufactured by Hitachi Chemical Co., Ltd.), 12 parts by mass of toluene, and 20 parts by mass of methyl ethyl ketone were mixed by a dissolver, and this mixed solution was mixed with an olefin copolymer. 50 parts by mass of an adhesive containing a hydroxyl-modified product (trade name "UNISTOL P-801", manufactured by Mitsui Chemicals, Inc.) was added and mixed by a dissolver to obtain a coating liquid for an ink-adhering layer.

[Preparation Example A5]
13.3 parts by mass of polyurethane resin (trade name "TA24-412A", manufactured by Hitachi Chemical Co., Ltd.), 12 parts by mass of toluene, and 20 parts by mass of methyl ethyl ketone were mixed by a dissolver, and this mixed solution was mixed with an olefin copolymer. 50 parts by mass of an adhesive containing a hydroxyl-modified product (trade name "UNISTOL P-801", manufactured by Mitsui Chemicals, Inc.) was added and mixed with a dissolver. Next, 1.6 parts by mass of a polyisocyanate compound (trade name "VM Hardener", manufactured by Toyo Ink Co., Ltd.) was added to the obtained mixture, and the mixture was stirred and mixed for further 5 minutes to apply an ink coating layer. A liquid was obtained.

Table 1 shows details of each material used.

[Example A1]
Both sides of the support obtained in Production Example A1 were subjected to corona discharge treatment at a strength of 30 W·min/m ² . Then, the treated support was coated with the coating liquid of Preparation Example A1 by a roll coater so that the solid content of the ink-deposited layer after drying on one side was 2.0 g/m ² . Then, it was dried using an oven at 60° C. to form an ink-adhering layer, thereby obtaining a composite material for offset printing of Example A1.

[Example A2]
A composite material for offset printing of Example A2 was obtained in the same manner as in Example A1 except that the coating liquid of Preparation Example A2 was used instead of the coating liquid of Preparation Example A1.

[Example A3]
A composite material for offset printing of Example A3 was obtained in the same manner as in Example A1 except that the coating liquid of Preparation Example A3 was used instead of the coating liquid of Preparation Example A1.

[Example A13]
A composite material for offset printing of Example A13 was obtained in the same manner as in Example A1 except that the coating liquid of Preparation Example A4 was used instead of the coating liquid of Preparation Example A1.

[Example A14]
A composite material for offset printing of Example A14 was obtained in the same manner as Example A1 except that the coating liquid of Preparation Example A5 was used instead of the coating liquid of Preparation Example A1.

[Comparative Examples A1 to A3]
The coating liquids for the ink-adhering layer were prepared with the raw materials and the compounding ratios shown in Table 1 and Table 2, respectively. An ink coating layer was provided in the same manner as in Example A1 except that these coating liquids for the ink coating layer were used instead of the coating liquid for Preparation Example A1, respectively. A composite material for offset printing was obtained.

[Comparative Example A4]
The coating liquids for the ink-adhering layer were prepared with the raw materials and the compounding ratios shown in Table 1 and Table 2. Comparative Example A1 was repeated except that the coating liquid for the ink coating layer was used in place of the coating liquid of Preparation Example A1 and the corona discharge treatment was omitted. A composite material for offset printing of Example A4 was obtained.

Table 2 shows the blending ratio and coating amount of each coating liquid.

Table 3 shows the evaluation results for the suitability evaluation of the liquid inks of Examples A1 to A3 and A13 to A14 and Comparative Examples A1 to A4.

Table 4 shows the structure of each composite material for offset printing. Further, Table 5 shows the evaluation results of these paper quality evaluations.

[Examples A4 to A7]
The coating liquids for the ink-adhering layer were prepared with the raw materials and the compounding ratios shown in Table 1 and Table 6, respectively. The same procedure as in Example A3 was conducted except that these coating liquids for the ink coating layer were used in place of the coating liquids for the ink coating layer in Example A3, and the ink coating layer was formed and implemented. The offset printing composite materials of Examples A4 to A7 were obtained.

[Examples A8 and A9]
Example A3 was performed in the same manner as in Example A3, except that the coating amount was changed to the coating amount shown in Table 6 (solid content of the ink coating layer after drying on one side) to provide the ink coating layer. A composite material for offset printing of A8 and A9 was obtained.

[Example A10]
Example A7 was carried out in the same manner as in Example A7 except that the coating amount was changed to the coating amount shown in Table 6 (the solid content of the ink coating layer after drying on one side) in Example A7 to provide the ink coating layer. A composite material for offset printing of A10 was obtained.

[Example A11]
A composite material for offset printing of Example A11 was obtained in the same manner as in Example A3, except that the support of Production Example A2 was used instead of the support of Production Example A1.

[Example A12]
The support of Production Example A3 is used in place of the support of Production Example A1 and the coating amount (solid content of the dried ink coating layer after drying on one side) is changed to the coating amount shown in Table 6 to provide the ink coating layer. Except for this, the same procedure as in Example A3 was carried out to obtain a composite material for offset printing of Example A12.

[Adhesive sheet]
One side of a polypropylene film having a thickness of 60 μm (trade name “Pyrene P2761”, manufactured by Toyobo Co., Ltd.) was subjected to silicone treatment to obtain a release sheet. Next, a solvent-based acrylic pressure-sensitive adhesive (trade name "Olivine BPS1109", manufactured by Toyo Ink and Chemicals, Inc.) was applied as a pressure-sensitive adhesive layer on one surface of each of the composite materials for offset printing of Examples and Comparative Examples after drying. It was coated with a comma coater so that the amount of work was 30 g/m ^2, and dried to obtain an offset printing composite material with an adhesive (offset printing composite material+adhesive layer).
Both of these were laminated so that the pressure-sensitive adhesive layer surface of the pressure-sensitive adhesive composite with offset printing and the silicone-coated surface of the release sheet were in contact with each other to obtain a pressure-sensitive adhesive sheet (compressed offset-printing composite material).

[Postcard]
The release sheet of the pressure-sensitive adhesive sheet was peeled off to expose the pressure-sensitive adhesive layer, and a postcard-sized photographic paper was attached to the exposed surface to obtain a postcard on which the composite material for offset printing was attached.

Table 6 shows the blending ratio and coating amount of each coating liquid.

Table 7 shows the evaluation results of Examples A1 to A14 and Comparative Examples A1 to A4.

[Evaluation method]
Evaluation of the composite material for offset printing, the pressure-sensitive adhesive sheet, and the postcard in the adjustment example A group, the example A group, and the comparative example A group was performed by the following methods.

[Aptitude evaluation for liquid ink]
In the offset printing composite materials obtained in each of the examples and comparative examples, the following printing was performed using an electrophotographic offset printing machine using liquid ink (device name "Indigo 5600", manufactured by Hewlett-Packard Japan). The suitability was evaluated.

[Liquid ink transferability]
Using the above printing machine, a black ink dot pattern having a density of 100% and a black ink dot pattern having a density of 30% was printed on one surface of each of the composite materials for offset printing of Examples and Comparative Examples. The printed state of the printed composite material for offset printing was magnified with a magnifying glass and visually judged, and a three-stage evaluation was performed based on the following criteria.
⊚: Good (clear image can be obtained)
○: Yes (images and characters may be slightly blurred, but there is no problem)
×: No (images and characters are blurred)

[Liquid ink adhesion]
Using the above-mentioned printing machine, solid printing images are printed for each of the four colors of black, cyan, magenta, and yellow and the superposed color of four colors on one surface of the composite material for offset printing of each of the examples and comparative examples. Then, a tape peeling test was carried out on the solid printed portion of each color. In the tape peeling test, a cellophane adhesive tape having a width of 18 mm (trade name "Cellotape (registered trademark) CT-18", manufactured by Nichiban Co., Ltd.) was adhered to the printed part of each color without unevenness, and about 5 mm/in 180 degree peeling. The tape was slowly peeled off at the speed of 2 seconds. The degree of fixation of the liquid ink on the composite material after peeling was visually determined, and three-level evaluation was performed according to the following criteria.
⊚: Good (no ink peeling observed)
○: Yes (the ink peels off slightly)
×: Not allowed (peeling of 30% or more of the cellophane tape peeling portion is recognized)

(Composite material for offset printing Paper quality evaluation)
[Opacity]
The opacity of the offset printing composite material obtained in each of the examples and comparative examples was measured according to the method described in JIS P8149:2000. The opacity is expressed as a percentage by dividing the single-sheet luminous reflectance measured by placing a black plate on the back surface of the composite material sample by the intrinsic luminous reflectance measured by placing a white board on the back surface of the composite material sample. It is a thing.

[Hue and whiteness]
The hues of the composite materials for offset printing obtained in each of the examples and the comparative examples, that is, the lightness index L and the chromaticness index a and b of the Hunter color system were measured by a Hunter color difference meter (trade name "SM Color Meter SM- T" manufactured by Suga Test Instruments Co., Ltd.). The whiteness is calculated according to the method described in JIS L1015:1999.

[Blocking resistance]
First, the obtained composite material for offset printing was cut into 100 mm length×15 mm width to prepare a test piece. The two test pieces thus obtained were stacked 20 mm apart in the lengthwise direction so that the coated surface and the non-coated surface of the ink-coated layer were in contact with each other, and then the hydraulic press machine (trade name "High Pressure Jack"). J-15", manufactured by As One Co., Ltd.) was applied at a pressure of 10.3 MPa for 10 minutes to prepare an evaluation sample.
Then, using a tensile tester (trade name "RTM-250", manufactured by Orientec Co., Ltd.), both ends of the evaluation sample in the lengthwise direction are respectively gripped and pulled at a speed of 200 mm/min, and the maximum load at this time is measured. It measured and made this the blocking value. Based on this blocking value, the blocking resistance was evaluated according to the following criteria. The blocking value of the composite material for offset printing is preferably 12000 gf or less, more preferably 6000 gf or less, and further preferably 3000 gf or less. If the blocking value of the composite material for offset printing is 12,000 gf or less, it is easy to feed and discharge the paper in various offset printing machines, and if it is 6000 gf or less, it becomes particularly good.
⊚: 3000 gf or less ○: 3001 to 6000 gf
Δ: 6001-12000 gf
X: 12001 gf or more

[Water resistance evaluation Wet rub]
First, an electrophotographic offset printing machine using a liquid ink (device name "Indigo 5600", manufactured by Hewlett-Packard Japan, Inc.) was used to obtain a density of 100 on the ink coating layer side of the obtained offset printing composite material. % Ink black solid pattern was printed. Then, these printed matters were fixed to a friction tester (device name “FR-2”, manufactured by Suga Test Instruments Co., Ltd.). Attach a cotton cloth soaked with 40 μl of tap water to the friction part of the friction tester, rub the printed matter 100 times while applying a load with a weight of 215 g, visually judge the degree of ink peeling, and evaluate it in 3 levels based on the following criteria. went.
⊚: 90% or more of the ink remains on the composite material for offset printing ◯: 70% or more and less than 90% of the ink remains on the composite material for offset printing Δ: 60% or more and less than 70% of the ink Remaining on the offset printing composite material x: Less than 60% of the ink remains on the offset printing composite material

[Postcard appearance evaluation]
The appearance of the postcard provided with the pressure-sensitive adhesive sheet was judged, and four-level evaluation was performed according to the following criteria.
⊚: Good (postcard impurities and roughness are hardly visible)
○: Good (postcard impurities and roughness are slightly visible)
△: OK (I can see the foreign matters and the roughness of the postcard, but
There is no problem)
×: Impossible (postcard foreign matters and roughness are visible, and it is difficult to see because it overlaps with images and characters)

(Examples B1, B2, B8, B9, Reference Examples B3 to B7 and Comparative Examples B1 to B3)
[Preparation of transparent support]
A commercially available biaxially stretched PET film (trade name “E5200”, thickness 75 μm, manufactured by Toyobo Co., Ltd.) was used as a transparent support containing a polyester resin.

[Preparation of coating liquid for ink coating layer]
The coating liquids for ink- deposited layers of Examples B1, B2, B8, B9 and Reference Examples B3 to B7 were prepared by the following procedure. First, a mixed solvent of toluene/methyl ethyl ketone (trade name “LP402 Solvent S”, manufactured by Toyo Ink Co., Ltd.) and a predetermined amount of a hydroxyl group-modified olefin adhesive (trade name “UNISTOL P-801” manufactured by Mitsui Chemicals, Inc.) or An acid-modified olefin-based adhesive (trade name "Surflen P-1000", manufactured by Mitsubishi Chemical Co., Ltd.) was added. This mixture was stirred and mixed at 500 rpm for 5 minutes using a magnetic stirrer (trade name "REMIX RSH-6DN", manufactured by As One Co.).
Next, in the case of adding a polyisocyanate compound, a predetermined amount of the polyisocyanate compound (trade name "VM Hardener", manufactured by Toyo Ink Co., Ltd.) is added to the obtained mixture, and the mixture is supplied to the magnetic stirrer at 500 rpm. The mixture was stirred and mixed for another 5 minutes.
When an anti-blocking agent is added, a predetermined amount of polymethylmethacrylate resin beads (trade name “Unipowder NMB-0220C”, average particle diameter 2 μm, or “Unipowder NMB-0520C”, average particle diameter) is added to the mixed solution. 5 μm, both manufactured by JX Nippon Steel & Nisseki Co., Ltd.) were further mixed and stirred and mixed for 5 minutes at 500 rpm using a magnetic stirrer.
On the other hand, the ink coating layer coating liquids of Comparative Examples B1 to B3 were prepared by the following procedure. Only one of a hydroxyl-modified olefin adhesive, an acid-modified olefin adhesive, and an anti-blocking agent is blended in the above toluene/methyl ethyl ketone mixed solvent, and this mixture is used at 500 rpm for 5 minutes using the above magnetic stirrer. Mix with stirring.
The coating liquids for ink-deposited layers were prepared so that the total solid content concentration was 10% by mass.

[Production of composite material for offset printing]
Using a bar coater (trade name "PI-1210 film coater", manufactured by Tester Sangyo Co., Ltd.), a predetermined dry coating is performed on the corona-treated surface of the transparent support by using the coating liquid for the ink coating layer. The coating amount is adjusted to 50% and dried in an Irie hot-air dryer (trade name "MO-S-450", manufactured by Temperature Equipment Laboratory Co., Ltd.) for 1 minute to obtain Examples B1, B2, and B8. , B9, reference examples B3 to B7 and comparative examples B1 to B3 were produced.

Table 8 shows the details of each raw material.

Table 9 shows the evaluation results of the compounding ratio of each compounding component, the dry coating amount, and the ink adhesion.

As is clear from Table 9 , Example B1 in which an ink coating layer containing a hydroxyl group-modified olefin-based adhesive or an acid-modified olefin-based adhesive having an acid value of 1 to 50 mgKOH/g was provided on a polyester-based transparent support , It was proved that the composite materials for offset printing of B2, B8, B9 and Reference Examples B3 to B7 were excellent in balance of ink adhesion as compared with Comparative Examples B1 to B3. Further, from the comparison between Examples B1, B2, B9 and Reference Examples B3 to B7 and Comparative Examples B1 to B3, it was determined that a hydroxyl group-modified olefin adhesive or an acid value-modified olefin adhesive having an acid value of 1 to 50 mgKOH/g. It was proved that the combined use of the polyisocyanate compound improves the ink adhesion under the Wet condition without impairing the ink adhesion under the Dry condition.

Table 10 shows the constitution and evaluation results of each offset printing composite material.

As is clear from Table 10, Examples B1, B2, B8 in which an ink coating layer containing a hydroxyl group-modified olefin adhesive or an acid-modified olefin adhesive having an acid value of 1 to 50 mgKOH/g was provided on a support. , B9 and the composite materials for offset printing of Reference Examples B3 to B7 were proved to have an excellent balance of blocking resistance and water resistance as compared with Comparative Examples B1 to B3. Further, by using the hydroxyl-modified olefin adhesive or the acid-modified olefin adhesive having an acid value of 1 to 50 mgKOH/g and the polyisocyanate compound in combination, particularly, the hydroxyl-modified olefin adhesive or the acid value of 1 to 50 mgKOH The offset printing composite materials of Examples B1 and B2 and Reference Examples B3 to B7 in which an ink coating layer containing an acid-modified olefin adhesive and a polyisocyanate compound of 100 g/g were provided on a polyester transparent support, It was proved that all of them have high transparency and are excellent in balance of blocking resistance, water resistance, and ink adhesion.

  On the other hand, in Comparative Examples B1 to B3 in which the hydroxyl group-modified olefin adhesive or the acid-modified olefin adhesive having an acid value of 1 to 50 mgKOH/g and the polyisocyanate compound are not used in combination, the blocking resistance and the water resistance are Could not be achieved at the same time.

[Evaluation method]
The measuring methods and evaluation criteria of various performances in the composite materials for offset printing of Example B group and Comparative example B group are as follows.

[Ink adhesion (dry condition)]
First, an electrophotographic offset printing machine using a liquid ink (device name "Indigo 5600", manufactured by Hewlett-Packard Japan, Inc.) was used to obtain a density of 100 on the ink coating layer side of the obtained offset printing composite material. % Ink black solid pattern was printed.
Then, an adhesive surface of cellophane tape (trade name "Cellotape" (registered trademark) CT-18, manufactured by Nichiban Co., Ltd.) was attached to the printed surface of these printed materials, and rubbed with a finger three times for sufficient adhesion. Then, the cellophane tape was manually peeled off at a high speed in the direction of 180 degrees from the printed matter, the degree of ink peeling was visually judged, and the following criteria were used to make a three-stage evaluation. The residual amount of ink in the composite material for offset printing in this test is preferably 70% or more, and more preferably 90% or more. When the residual amount of ink is 70% or more, the ink adhesion of the composite material for offset printing is sufficient, and when it is 90% or more, it can be said that the ink is not easily peeled off, that is, a strong printed matter.
⊚: 90% or more of the ink remains on the composite material for offset printing ◯: 70% or more and less than 90% of the ink remains on the composite material for offset printing ×: Less than 70% of the ink composite for offset printing Remains on the material

[Ink adhesion (Wet condition)]
Similar to the above-described ink adhesion (Dry condition) evaluation, a solid black pattern having a density of 100% was printed on the ink-adhering layer side of the obtained offset printing composite material. Then, these printed matters were immersed in ion exchange water at 23°C.
After 24 hours, the printed matter was taken out from the water. After gently wiping off the water on the surface of the printed matter with a tissue paper (trade name "JK Wiper", made by Kimberly Clark Co., Ltd.), a cellophane tape (trade name "Cellotape (registered trademark) CT-18") was printed on the printed surface of the printed matter. (Manufactured by Nichiban Co., Ltd.) was adhered and rubbed with a finger three times for sufficient adhesion. Then, the cellophane tape was manually peeled off at a high speed in the direction of 180 degrees from the printed matter, and the degree of ink peeling was visually determined, and similarly to the Dyr condition, a three-level evaluation was performed based on the following criteria.
⊚: 90% or more of the ink remains on the composite material for offset printing ◯: 70% or more and less than 90% of the ink remains on the composite material for offset printing ×: Less than 70% of the ink composite for offset printing Remains on the material

[Opacity]
The opacity of the composite material for offset printing conforms to "Paper and board-Opacity test method (paper backing)-Diffuse illumination method" defined in JIS P8149:2000, and a color meter (trade name "SM color Meter SM-T", manufactured by Suga Test Instruments Co., Ltd.).
Specifically, a black standard plate was applied to one side of the obtained composite material for offset printing to measure the luminous reflectance of a single sheet, and separately from this, a white standard plate was applied to one side of the same sample. Then, the intrinsic luminous reflectance was measured, and the ratio of these reflectances (single sheet luminous reflectance/intrinsic luminous reflectance) was calculated as a percentage, which was taken as the opacity (%).

[Blocking resistance]
First, the obtained composite material for offset printing was cut into 100 mm length×15 mm width to prepare a test piece. The two test pieces obtained were overlapped so that the coated surface and the non-coated surface of the ink coating layer were in contact with each other while being shifted by 20 mm in the length direction, and then the hydraulic press machine (trade name: “High Pressure Jack”). J-15", manufactured by As One Co., Ltd.) was applied at a pressure of 10.3 MPa for 10 minutes to prepare an evaluation sample.
Then, using a tensile tester (trade name "RTM-250", manufactured by Orientec Co., Ltd.), both ends of the evaluation sample in the lengthwise direction are respectively gripped and pulled at a speed of 200 mm/min, and the maximum load at this time is measured. It measured and made this the blocking value. Based on this blocking value, the blocking resistance was evaluated according to the following criteria. The blocking value of the offset printing composite material is preferably 12000 gf or less, more preferably 6000 gf or less, and further preferably 3000 gf or less. If the blocking value of the composite material for offset printing is 12000 gf or less, it is easy to feed and discharge the paper in various offset printing machines, and if it is 6000 gf or less, it becomes particularly good.
⊚: 3000 gf or less ○: 3001 to 6000 gf
Δ: 6001-12000 gf
X: 12001 gf or more

[Water resistance evaluation Wet rub]
First, an electrophotographic offset printing machine using a liquid ink (device name “Indigo 5600”, manufactured by Hewlett-Packard Japan, Inc.) was used to obtain a density of 100 on the ink coating layer side of the obtained composite material for offset printing. % Ink black solid pattern was printed. Then, these printed matters were fixed to a friction tester (device name “FR-2”, manufactured by Suga Test Instruments Co., Ltd.). Attach a cotton cloth soaked with 40 μl of tap water to the friction part of the friction tester, rub the printed matter 100 times while applying a load with a weight of 215 g, visually judge the degree of ink peeling, and make a three-level evaluation based on the following criteria. went.
⊚: 90% or more of the ink remains on the composite material for offset printing ◯: 70% or more and less than 90% of the ink remains on the composite material for offset printing Δ: 60% or more and less than 70% of the ink Remaining on the offset printing composite material x: Less than 60% of the ink remains on the offset printing composite material

Example B10
A window film was produced by the following procedure.
[Preparation of transparent support]
A commercially available biaxially stretched PET film (trade name “TOYOBO ester film E5200”, thickness 75 μm, manufactured by Toyobo Co., Ltd.) was used as a transparent support containing a polyester resin.
[Preparation of coating liquid for ink coating layer]
The ink coating layer coating liquid was prepared by the following procedure. First, in 50 parts by mass of a mixed solvent of toluene/methyl ethyl ketone (trade name "LP402 solvent S", manufactured by Toyo Ink Co., Ltd.), a hydroxyl group-modified olefin adhesive (trade name "UNISTOL P-801", manufactured by Mitsui Chemicals, Inc.) is used. 100 parts by mass was compounded. This mixture was stirred and mixed at 500 rpm for 5 minutes using a magnetic stirrer (trade name "REMIX RSH-6DN", manufactured by As One Co.). Then, 20 parts by mass of a polyisocyanate compound (trade name “VM Hardener”, manufactured by Toyo Ink Co., Ltd.) was added to the obtained mixture, and the mixture was further stirred and mixed at 500 rpm for 5 minutes using the magnetic stirrer, A coating liquid for an ink coating layer was obtained.

[Molding of composite material for offset printing]
On the corona discharge treated surface of the transparent support, the coating liquid for the ink coating layer was dried using a bar coater (trade name "PI-1210 film coater" manufactured by Tester Sangyo Co., Ltd.). To a mass of 2.0 g/m ² (dry coating amount), and 1 at 50° C. with an Irie hot air dryer (trade name “MO-S-450”, manufactured by Temperature Equipment Research Institute) After being dried for a minute, the ink coating layer was laminated to obtain a composite material for offset printing.

[Preparation of adhesive coating liquid]
The adhesive coating liquid was prepared by the following procedure. First, 100 parts by mass of an adhesive (trade name "Ciavine SH-101", manufactured by Toyochem Co., Ltd.), 5 parts by mass of a curing agent (trade name "Ciavine T-501B", manufactured by Toyochem Co., Ltd.), solvent (toluene, Wako Pure Chemical Industries) 200 parts by mass). This mixture was stirred with a stirrer (trade name "Portable Mixer A640" manufactured by Satake Chemical Machinery Co., Ltd.) to obtain an adhesive coating solution.

[Molding of window film]
On the surface of the composite material for offset printing obtained by molding the composite material for offset printing, which is opposite to the surface on which the ink coating layer is laminated, a bar coater (trade name "PI-1210 film coater", Tester Sangyo Co., Ltd. The above-mentioned pressure-sensitive adhesive coating liquid was applied by using a product manufactured by K.K.) so that the solid content after drying was 30 g/m ² . After that, the pressure-sensitive adhesive coating liquid is dried at 70° C. for 5 minutes with an Irie hot-air dryer (trade name “MO-S-450”, manufactured by Temperature Equipment Research Institute), the pressure-sensitive adhesive layer is laminated, and the window film is formed. Got On the surface of the pressure-sensitive adhesive layer of the obtained window film, as a release sheet, one side of a polypropylene film having a thickness of 60 μm (trade name “Pyrene P2761”, manufactured by Toyobo Co., Ltd.) was subjected to silicone treatment, and the surface of the pressure-sensitive adhesive layer It was laminated so that the silicone treated surface of the release sheet was in contact.

[Making window film sample]
Next, a window film laminated with a release sheet was cut into A3 size, and an ink-applied layer was formed using an electrophotographic offset printing machine using liquid ink (device name "Indigo 5600", manufactured by Hewlett-Packard Japan). A pattern of ISO 12640-1:1997 (N5 of JIS X 9201:2001) was printed on the surface provided with, to obtain a window film sample.

[Appearance evaluation of window film]
The release sheet was peeled off from the sample, and the window film and the glass surface were adhered so that the surface of the pressure-sensitive adhesive layer of the window film was in contact with the smooth and vertical surface of the glass. It was confirmed that the window film attached to the glass surface retained the attached position without falling off from the vertical glass surface, and had a good appearance and function as a window film.

11 Offset Printing Composite Material 21 Support or Transparent Support 21a Surface 21b Surface 31 Ink Deposition Layer 41 Adhesive Layer 41a Surface 51 Adhesive Sheet 61 Recording Paper 71 Postcard

Claims (12)

A support, and a side opposite to the ink deposited layer printed media display surface ink is adhered to the outermost surface is formed of a Rutotomoni the support provided on at least one surface side of the support,
The composite material for offset printing, wherein the ink coating layer contains a hydroxyl group-modified olefin adhesive and a polyisocyanate compound . The ink deposition layer contains at least a white pigment and a urethane-based resins,
The composite material for offset printing according to claim 1 . The ink coating layer contains at least 5 to 40% by mass of the white pigment, 5 to 40% by mass of the urethane-based resin, and 30 to 80% by mass of the hydroxyl group-modified olefin-based adhesive , in terms of solid content. contains,
The composite material for offset printing according to claim 2 . The solid content of the ink-deposited layer is 0.5 to 10 g/m ² per side.
Offset printing composite material according to any one of claims 1-3. The white pigment contains one or more selected from the group consisting of titanium oxide, barium sulfate, calcium sulfate, and zinc oxide,
Offset printing composite material according to any one of claims 2-4. The hydroxyl group-modified olefin adhesive is a hydroxyl group-modified product of an olefin (co)polymer,
The olefin-based (co)polymer is one or more monomers selected from the group consisting of ethylene, propylene, butene-1,4-methyl-1-pentene, hexene-1, octene-1, styrene, and conjugated dienes. Is a homopolymer or a copolymer,
Offset printing composite material according to any one of claims 1-5. The ink deposition layer, offset printing composite material according to any one of claims 1 to 6 further containing an anti-blocking agent. The support contains a thermoplastic resin and at least one selected from the group consisting of inorganic fillers and organic fillers,
Offset printing composite material according to any one of claims 1-7. Comprises an offset printing composite material according to any one of claims 1-8, and an adhesive layer provided on at least one surface side of the offset printing composite, and
Adhesive sheet. The pressure-sensitive adhesive sheet according to claim 9 , and a recording sheet provided via the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet,
Postcard. The support is a transparent support containing a polyester resin,
The opacity of the offset printing composite material measured in accordance with JIS-P8149:2000 is 10% or less,
Offset printing composite material according to any one of claims 1-7. A window film comprising the composite material for offset printing according to claim 11 .

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