JP2827296B2 - Image receiving sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image receiving sheet. More specifically, the present invention relates to an image receiving sheet that is excellent in color proofing properties in plate making and printing processes and is excellent in handling properties.

[Related Art] In recent years, in order to improve the quality and stabilization of printed matter and the efficiency of the printing process, etc., a method of making a negative or positive film of a manuscript in the process of plate making and printing and correcting characters, line drawings, and colors Because of its excellent reproduction characteristics, it has been systematized and is being actively implemented. Above all, for color proofing, an image receiving sheet having excellent adhesion to a color light-sensitive material film is required. The structure of the image receiving sheet comprises an image receiving layer and a support layer. In general, the support layer is dominated by paper which has been specially processed by coating, impregnation or the like.

[Problems to be Solved by the Invention] However, the above-mentioned image receiving sheet has the following problems. That is, an image receiving sheet using paper as a support has insufficient mechanical strength, water resistance, and chemical resistance, or has strong fold marks due to bending or the like, so that the image receiving layer or the light-sensitive material layer near the fold is missing. Is easy to occur and handling is inferior.

The present invention solves these disadvantages of the prior art, and has a coating layer having excellent adhesion to a support and adhesion to a light-sensitive material layer, and furthermore, mechanical strength, water resistance, and chemical resistance. An object of the present invention is to provide an image receiving sheet having excellent antistatic properties.

[Means for Solving the Problems] The present invention provides a biaxially oriented polyester film, on one surface of which is provided a coating layer mainly composed of a halogenated polyolefin containing 10 to 80% by weight of halogen, and on the other surface. The gist of the present invention is an image receiving sheet provided with an antistatic layer.

The polyester in the present invention is a well-known polyester,
Specifically, for example, at least bifunctional carboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis-α, β (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid, adipic acid, and sebacic acid Polyesters obtained by polycondensing one kind with at least one kind of glycol such as ethylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol and the like can be mentioned. Further, the polyester may be blended or copolymerized with another polymer within a range not to impair the object of the present invention, and may include an antioxidant, a heat stabilizer, a lubricant, a pigment, an ultraviolet absorber and the like. May be. The intrinsic viscosity of the polyester (measured in orthochlorophenol at 25 ° C.) is from 0.4 to 2.0, preferably from 0.5 to 1.0.

In the present invention, polyethylene terephthalate, polyethylene-2,6-naphthalate, polyethylene-α, β-bis (2-chlorophenoxy) ethane-
Particularly excellent effects are obtained when 4,4'-dicarboxylate is used.

The coating layer of the present invention is a layer composed of a composition mainly containing a halogenated polyolefin containing 10 to 80% by weight of halogen. The layer as the main component in the present invention refers to a layer which is 50% by weight or more, preferably 60% by weight or more in the coating layer, and other substances may be appropriately added. The resin to be added is not particularly limited, but typical examples include various resins such as urethane resin, polyester resin, acrylic resin, vinyl resin, and styrene resin.

In the present invention, the halogenated polyolefin is obtained by halogenating a polyolefin, and examples thereof include the following.

A. Halogenated polyethylene and its copolymer B. Halogenated polypropylene and its copolymer C. Halogenated polybutylene and its copolymer D. Halogenated polyisobutylene and its copolymer Based on things
10 to 80% by weight. If the content of halogen is less than this, the adhesion will be poor, while if it is more than this, the solubility of this polymer in the solvent will be low, the film-forming property will be poor, the softening point will be too high and the laminability will be poor.

The halogenated polyolefin can be produced by a generally known method. For example, it is produced by dissolving a polyolefin in a halogen-based solvent, heating, halogenating under pressure or normal pressure, and then subjecting the process to distillation, washing, drying and the like. Among the halogenated polyolefins, those having a low impurity content such as halogen molecules, hydrogen halides and other halogen compounds are preferably used. Known stabilizers, antioxidants, ultraviolet absorbers, and the like may be added to the halogenated polyolefin as needed as long as the properties of the present invention are not impaired. Of the halogenated polyolefins, chlorinated polyolefins are particularly preferably used in terms of ease of production.

In the present invention, when the sheet is used as an image-receiving sheet, if the sheet is transparent, it may impair the clarity of the transferred image and the color proofing, and it is preferable to include white inorganic particles in the biaxially oriented polyester film.

Examples of the white inorganic particles according to the present invention include zinc carbonate, zinc oxide, zinc sulfide, talc, kaolin, heavy / light or synthetic calcium carbonate, titanium oxide, silica, lithium fluoride, barium sulfate, alumina, and zirconia. , Calcium phosphate, natural or synthetic swellable or non-swellable mica, etc., among these, titanium oxide, calcium carbonate, silica is desirable, the particle form is hollow porous or non-hollow porous,
It may be in the form of a plate, a column or the like, but a spherical one is preferred.

Further, the average particle size of the white inorganic particles is preferably 0.1 to 4.0 μm, more preferably 0.1 to 2.0 μm. Average particle size is 0.1
If it is less than μm, it tends to form aggregates and is poor in uniform dispersibility,
If it exceeds 4.0 μm, the smoothness tends to deteriorate. The content of the white inorganic particles is 1 to 50 parts by weight, preferably 5 to 30 parts by weight based on 100 parts by weight of the resin. If the content is less than 1 part by weight, the whiteness is insufficient, and if it exceeds 50 parts by weight, tearing in the film stretching step frequently occurs, which is not preferable.
For the white inorganic particles, it is preferable to use a whitening agent or a fluorescent coloring agent having a function to further increase the whiteness of the base film.

In the present invention, when used as an image receiving sheet, flexibility and cushioning properties are imparted to improve the transferability by lamination, and in order to reduce the weight of the image receiving sheet, a biaxially oriented polyester film is made of a different material from the biaxially oriented polyester film. It is preferable to include a compatible thermoplastic resin.

The thermoplastic resin referred to in the present invention is preferably a thermoplastic resin other than polyester and incompatible with polyester. The thermoplastic resin incompatible with the polyester is defined as a glass transition temperature corresponding to the polyester in a system obtained by melt-mixing the polyester and the thermoplastic resin in a measurement by a known method using a differential scanning calorimeter (DSC). (Hereinafter abbreviated as Tg) other than Tg corresponding to the thermoplastic resin
Is the resin observed. A thermoplastic resin that is incompatible with the polyester has a great effect of dispersing in a particle state in the polyester and forming voids in the polyester film by stretching. The melting point of such a thermoplastic resin is preferably lower than the melting point of the polyester and higher than the temperature used to orient the film support. From such a point, an olefin-based polymer such as polyethylene, polypropylene, and poly-4-methyl-1-pentene or a copolymer thereof is preferable. In particular, polypropylene is preferable. Miniaturize the empty space by stretching,
In order to reduce the surface roughness, the addition of olefin-based polymers and copolymers having a carboxyl group, a polar group such as an epoxy group, or a functional group reactive with polyester reduces the dispersion diameter, and thus, It is more preferable because the voids can be made finer by stretching and the surface roughness can be reduced.

The content of the thermoplastic resin is 100% of the polyester resin.
It is 5 to 100 parts by weight, preferably 10 to 50 parts by weight based on parts by weight.

In the present invention, when used as an image receiving sheet, the image receiving sheet has an antistatic function in order to avoid adhesion of dust and the like due to static electricity and sticking between the image receiving sheets, and to improve image clarity, transferability, handling, and the like. Must be granted.

The antistatic layer referred to in the present invention is a coating layer made of an antistatic agent, a resin layer containing an antistatic agent, a vapor-deposited layer made of a metal or a metal oxide, and the like. Agents, conductive polymers, conductive carbon fine particles, metal or metal oxide fine particles, and the like. The antistatic property is based on the surface resistivity, which is one of the criteria,
-Measured by a high insulation resistance meter based on C-1303
The range is preferably 10 ⁵ to 10 ¹³ (Ω), and more preferably 10 ⁸ to 10 ¹¹ (Ω).

The polyester film constituting the image receiving sheet of the present invention needs to be in a biaxially oriented state in terms of mechanical strength, dimensional stability, heat resistance, chemical resistance, rigidity and the like. The thickness of the biaxially oriented polyester film is not particularly limited, but is preferably from 10 to 500 µm, more preferably from 30 to 300 µm, and excellent in practical handling as a base material. The surface roughness and optical haze of the biaxially oriented polyester film are not particularly limited and may be desired.However, in the case of a film containing white inorganic particles, JIS-L-1074 It is desirable that the whiteness is 50% or more and the light reflectance is 60% or more according to the measuring method based on JIS. The surface roughness (Ra) of the film is preferably 1.0 μm or less, more preferably 0.5 μm or less, as measured according to JIS-B-0601.

The integrated thickness of the coating layer constituting the image receiving sheet of the present invention,
Although not particularly limited, the thickness is preferably 0.01 to 50 μm, and the thickness within the range of 0.05 to 20 μm is desirable in terms of uniformity of formation of the coating layer, adhesion, and the like.

The surface roughness (Ra) of the coating layer is preferably 0.5 μm or less, more preferably 0.2 μm or less.

Further, if necessary, known additives such as an antifoaming agent and a coating improver in an amount not impairing the effects of the present invention may be added to the coating layer.
It may contain a thickener, an antistatic agent, an antioxidant, an ultraviolet absorber, a dye, a pigment, and the like, or may contain fine particles made of an inorganic or organic compound as a lubricant.

Next, the manufacturing method of the present invention will be described. First, after sufficiently drying the polyester pellets polymerized by a conventional method, a known extruder, preferably fed to a melt extruder having a compression ratio of 3.8 or more, the temperature at which the pellets are melted, the temperature at which the polymer is decomposed or lower. At a temperature, the sheet is melt-extruded from a slit-shaped die into a sheet and cooled and solidified to form an unstretched sheet. At this time, the intrinsic viscosity of the unstretched sheet is desirably 0.5 or more from the viewpoint of film properties. Next, the unstretched sheet is stretched as necessary by a known method to obtain a biaxially oriented polyester film. The stretching method is not particularly limited, for example, simultaneous biaxial vertical-horizontal, vertical
It is preferable that the film is biaxially stretched by stretching such as horizontal, vertical, or double-length.

Next, as a method of providing a coating layer on one side of the polyester film and providing an antistatic layer on the other side, first, the coating layer is first applied to a biaxially oriented film serving as a substrate in a film forming step by a predetermined amount. A method in which the prepared solution is applied and then dried.

A method of providing a coating-drying step after winding as a single base film.

A method in which a solution adjusted to a predetermined amount is applied to a basic polyester unstretched film in a film forming step, dried, and then biaxially stretched sequentially or simultaneously.

A method in which a polyester unstretched film serving as a substrate is stretched in one direction in advance in a film forming process, a solution adjusted to a predetermined amount is applied thereto, dried, and stretched in a direction perpendicular to the primary stretching direction.

And the like can be preferably applied. Next, for the antistatic layer, a conventional method such as a method of applying and drying a coating material having an antistatic property on the opposite surface of the coating layer provided in the above or a method of vacuum-depositing a metal or metal oxide is applied. it can. The composition to be applied may be used in the form of an organic solvent such as an organic solvent using an organic solvent, for example, an aromatic hydrocarbon system, a chlorinated hydrocarbon system, an ester system, a ketone system, or a mixture thereof. It may be used in the form of a dispersed suspension.

The method for applying the coating layer and the antistatic layer is not particularly limited, and generally known methods are effectively used. For example, as a coating method, a known method such as a gravure coating method, a reverse coating method, a kiss coating method, a die coating method, and a metaling bar coating method can be applied.

In addition, by performing a known surface treatment such as a corona discharge treatment in the air or in various other atmospheres as needed before coating, not only the coatability is improved, but also the coating layer and the antistatic layer are more improved. Can be formed firmly on the polyester film surface. The concentration of the coating material and the conditions for drying the coating film are not particularly limited, but the drying conditions for the coating film are desirably performed within a range that does not adversely affect the properties of each layer and the base film.

[Evaluation Method] The characteristic values of the present invention are based on the following measurement methods and evaluation criteria.

(1) Adhesiveness of coating layer The adhesive force of the coating layer / base film was measured by inserting a cross cut (100 pieces / cm ² ) on the coating layer and making a 45 ° cello tape: CT-24 (Nichiban) on the cross cut surface. Co., Ltd.), apply a load of about 5 kg using a hand roller, reciprocate 10 times, press and compress, and forcibly peel the cellophane tape in the 180 ° direction by hand. Observed and evaluated. The criterion is ◎: extremely good (no peeling),
：: good (peeling area less than 5%), Δ: slightly poor (peeling area 5% or more and less than 20%), ×: bad (peeling area 20% or more).

(2) Water resistance After the polyester film having the coating layer formed thereon is immersed in warm water at 50 ° C for 30 minutes, a cross cut (10
0 / cm ² ) and evaluated and judged in the same manner as in the above (1).
In addition, when the surface condition was visually observed to be abnormal (white turbidity, etc.), the cellophane evaluation was good (○), but was poor (×).

(3) Blocking resistance The blocking property was measured at 20 ° C and 60 ° C according to JIS-Z-0219.
The blocking property after 24 hours was evaluated by applying a load of 300 g / 12 cm ² in ± 5% RH. The evaluation criteria were ：: good, Δ: slightly poor, ×: bad.

(4) Laminating property A commercially available color art film (manufactured by Fuji Photo Film Co., Ltd.) was used as the photosensitive material film, and the photosensitive material layer was superimposed on the image receiving sheet, and then thermally laminated at a temperature of 115 ° C. with a laminator machine. The material film was peeled off, and the transfer adhesion of the light-sensitive material layer was evaluated.

：: good (good adhesion) △: slightly good (slightly poor adhesion) ×: poor (poor adhesion) (5) Bendability An image-receiving sheet using the same photosensitive material film as in (4) above After the photosensitive material layer was transferred well, the image receiving sheet was repeatedly bent at 180 ° five times, and the state of the transferred image in the vicinity of the fold was visually observed to make a judgment based on the following criteria. That is, a sample having no change at all was judged as “○”, a sample with a slight image uplift was judged as “△”, and an image with peeled or raised image was judged as “x”.

(6) Chemical resistance The biaxially oriented polyester film having the coating layer formed thereon was immersed in a 1% by weight aqueous sodium hydroxide solution for 15 minutes, and evaluated in the same manner as in (1) above.

[Function of the Invention] In the present invention, an antistatic layer is formed on one surface of a polyester film, and a coating layer is formed on the other surface using a coating material containing a specific halogenated polyolefin as a main component. The following excellent effects could be obtained without deteriorating the properties of the film.

[Effects of the Invention] (1) The image receiving sheet of the present invention has high mechanical strength and excellent bending resistance, and thus has good handleability.

(2) The image-receiving sheet of the present invention is excellent in adhesion to a transferred image, so that a clear transferred image is obtained.

(3) The image-receiving sheet of the present invention is excellent in chemical resistance and water resistance, so that the characteristics do not deteriorate even if a hot water treatment or the like is performed in post-processing.

(4) Since the image receiving sheet of the present invention has antistatic properties, clear transferability can be obtained without adhesion of dust and the like in handling.

[Uses of the Invention] The image receiving sheet of the present invention is used for proofreading of printed matter, and is preferably used for color proofing.

EXAMPLES The present invention will be described with reference to the following Examples and Comparative Examples.
The present invention is not limited to these. The amount of each compound is defined as weight%.

Example 1 A homopolymer chip of polyethylene terephthalate (intrinsic viscosity: 0.62, melting point: 259 ° C.) manufactured by a conventional method was mixed with 1
It was dried under reduced pressure (3 mm Hg) at 80 ° C. for 2 hours. 28
It is fed to an extruder having a screw having a compression ratio of 3.8 at 0 ° C.
Melt extrusion from mold die, surface temperature of 20 using electrostatic imprinting
The film was wound around a cooling drum at ℃ to be cooled and solidified to obtain an unstretched film. The obtained film was stretched 3.3 times in the machine direction by a roll stretching method at 90 ° C., and then stretched 3.6 times in the width direction by a tenter stretching method, and relaxed by 2% in the transverse direction.
Heat treatment was performed at 10 ° C. for 10 seconds to obtain a biaxially oriented film having a thickness of 100 μm.

After subjecting one surface of the obtained biaxially oriented polyester film to a corona discharge treatment, 2.5 parts by weight of a carboxyl group and a methylol group were introduced as functional groups into methyl methacrylate / ethyl acrylate (50/50) mol% on the surface. Acrylic polymer (average molecular weight 500,000) and SO ₂ O ^- X ⁺ group X ⁺
A water-based coating material having H ⁺ as an ion and having a weight ratio of 80:20 and a weight ratio of 80:20 to sulfonated polyethylene having an average molecular weight of 70,000 was bar-coated and dried at 110 ° C. to give a surface specific resistance of 8 An antistatic layer of × 10 ⁹ (Ω) was formed.

Next, on the opposite side of the antistatic layer, a chlorinated polypropylene with a chlorine content of 30% (Supercron, manufactured by Sanyo Kokusaku Pulp Co., Ltd.) was used as a diluting solvent and toluene was used as a diluting solvent, and a coating material of 20% was applied by a reverse coating method. Then, the coating layer was dried at 120 ° C. for 1 minute to obtain an image receiving sheet having a coating layer of 2.0 μm. The properties of this image receiving sheet were good (O) in all of the adhesion, water resistance, blocking resistance, laminating property, bending property, and chemical resistance of the coating layer.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-200535 (JP, A) JP-A-63-179356 (JP, A) JP-A-47-324 (JP, A) JP-A 55-1979 2241 (JP, A) JP-A-1-96640 (JP, A) JP-A-1-96641 (JP, A) JP-A-1-165633 (JP, A) JP-A-63-74052 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03F 7/105 G03F 7/11

Claims (4)

(57) [Claims] 1. A biaxially oriented polyester film having a coating layer mainly composed of a halogenated polyolefin containing 10 to 80% by weight of halogen on one surface and an antistatic layer provided on the other surface. Characteristic image receiving sheet. 2. The image receiving sheet according to claim 1, wherein a main component of the coating layer is a chlorinated polyolefin. 3. The film according to claim 1, wherein the biaxially oriented polyester film contains white inorganic particles.
The image receiving sheet as described in the above. 4. The image receiving sheet according to claim 1, wherein the biaxially oriented polyester film contains a different kind of thermoplastic resin which is incompatible with the biaxially oriented polyester film.