JPH0465794B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a laser recording film using a heat mode recording method, and particularly to a laser recording film that has excellent performance as a plate-making film. In recent years, many methods using laser light have been proposed in fields where high-speed or real-time recording of information is required. This method utilizes the strength and resolution of the optical energy of laser light, and the laser light is irradiated onto a substance with good light absorption, and the heated material that absorbs the light is deposited on the image receiving surface. It records images. [Prior Art] The present inventors also achieved high blackening density with respect to such recording films by using a non-self-oxidizing binder as a binder and further using graphite as heat-absorbing fine particles. Furthermore, by containing a heat ray absorber that has a strong absorption ability in the wavelength range of the YAG laser beam used for recording, it is possible to easily transfer the recording medium to the transfer image receiving surface of paper, printing plates, etc., and it is also transparent. The patent application No. 59-41724 was filed under the heading that it is possible to obtain a laser recording film which can prevent any residue of the recording medium from remaining on the substrate and which can produce high-resolution negative and positive images.
However, such a recording layer itself is easily scratched, and the dry coating film thickness is as thin as approximately 0.5 μm.
The scratches easily reach not only the surface of the recording layer but also the surface of the substrate. Such scratches significantly impair the function of the film for laser recording. As a way to solve this problem, the present inventors provided a protective layer made of thermoplastic polymer on the recording layer, thereby obtaining a laser recording film that has remarkable scratch resistance compared to conventional laser recording films. I discovered this and applied for a special patent application in 1982.
No. 112311, filed as 59-185176. [Problems with the Prior Art] However, when a protective layer is provided, the overall thickness of the coating increases, and there is a concern that the sensitivity of laser recording may decrease. The scratch resistance is also affected by the material of the protective layer, but in general, the scratch resistance improves as the film thickness increases. Further, the sensitivity by laser recording is good as long as the coating thickness is thin, and image forming performance and scratch resistance are inversely proportional. If a protective layer is provided, when a laser beam is irradiated from the support side, heat attenuation occurs between the recording layer and the protective layer, which may affect transferability and cause a decrease in resolution. [Means for Solving the Problems] As a result of intensive studies to solve these problems, the inventors of the present invention have developed a protective layer consisting of a thermoplastic polymer and a heat-absorbing pigment on the surface of the recording layer on a transparent support. The present invention was achieved by discovering that by providing a layer, a laser recording film having remarkable image forming properties and scratch resistance compared to conventional laser recording films can be obtained. That is, the present invention contains, on a transparent substrate, a non-self-oxidizing binder, fine particles that provide high blackening density and absorb heat, and a heat ray absorber that has strong absorption ability in the wavelength range of laser light used for recording. The present invention provides a laser recording film having a recording layer provided thereon, characterized in that a protective layer made of a thermoplastic polymer and a heat-absorbing pigment is provided on the recording layer. [Structure of the present invention] As a method of recording on the laser recording film of the present invention, as shown in FIG. 2, a laser beam 3 adjusted through a normal lens system and adjustment device is scanned from the transparent support 1 side. A method can be used in which a layer (transfer supply body) 2 coated with a recording medium is deposited on the image receiving surface of the transfer image receptor 4 to record an image. It is desirable that the transfer image receiver 4 be mounted in contact with the transfer supply member 2, and resolution can be improved by improving the degree of adhesion by reducing the pressure. According to this method, the transfer image receptor 4 can be transferred in one operation.
A positive image can be obtained on the top and a negative image can be obtained on the transfer supply body 2. The negative film can be used as an original film when producing a printing resin plate, and the positive image can be used as a proof copy or a direct printing plate depending on the type of transfer image receptor 4. The support for the laser recording film of the present invention, especially the laser platemaking film, may be any film that transmits laser light, such as polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, polypropylene, polycarbonate, nylon-6, polycarbonate, etc. Examples include films such as ether sulfone. In particular, biaxially stretched films of polyethylene terephthalate and polypropylene are preferred because they have excellent transparency, strength, and dimensional stability. Examples of pigments that absorb heat in the recording medium and those that have high light-shielding properties include graphite. This graphite can be used alone or in a mixture with carbon black or the like. In order to provide a thin film with a high blackening density, the graphite preferably has fine particles of 2 μm or less in size. More preferably
More than 50% are less than 0.4μ, 25% are less than 0.2μ
Graphite having a particle size distribution of % or more is suitable. Non-self-oxidizing binders in the recording medium include acrylic resins, cellulose derivatives other than nitrocellulose, phenolic resins, polyvinyl chloride,
Polyvinyl chloride-vinyl acetate copolymer and the like can be used. By using a non-self-oxidizing binder resin, there are no concerns about the safety of self-oxidizing binder resins such as nitrocellulose during storage or the problems that occur when irradiated with laser light. The blackening density of the recording medium is 0.5 to provide light-shielding properties.
It is preferably 2.0 or more. If the blackening density is low, the light-shielding performance as a negative film (original film for plate making) will be poor, and the print will be weak even as a positive image. Therefore, the non-self-oxidizing binder resin is used in an amount of 20 to 100 parts by weight, preferably 50 parts by weight or less, based on 100 parts of graphite. Examples of the heat ray absorbent contained in the recording layer of the present invention include compounds represented by the following general formula or. General formula; (Here, R is hydrogen or a lower alkyl group, X is an anion selected from the group consisting of hexafluoroarsenate ion, hexafluoroantimonate ion, fluoroborate ion, and perchlorate ion, and m is 0 or an integer between 1 and 2. Ar is

[expression] or

[Formula], n is an integer of 1 or 2, and m is 2, then A is

〔Effect of the invention〕

The laser recording film of the present invention is a real-time recording that does not require post-processing such as developing and fixing, and is not sensitive to visible light, so darkroom operation is not necessary. It is ideal for directly recording computer-processed information, and has excellent resolution and scratch resistance, so it can be widely applied. [Example] The present invention will be described below with reference to Examples. All parts in the examples represent parts by weight. Example 1 A graphite dispersion having the following formulation 1 was coated onto a 100 μm polyester film by bar coating and dried at 90° C. to form a recording layer. A liquid mixture consisting of Formulation 2 was applied onto this recording layer by dip coating and dried at 90°C to form a protective layer. Dry film thickness, blackening concentration, scratch resistance test results, and Nd-YAG laser (wavelength 1064nm output)
Table 1 summarizes the results of the image formation test using 10W irradiation of 0.5 Joule/cm ² ) on the recording medium. Formulation 1 Graphite 100 parts Ethylcellulose 36 parts Ethyl acetate 1224 parts Bis(P-diethylaminophenyl)
6.8 parts [N,N-bis-(P-diethylaminophenyl)-P-aminophenyl] Aminium hexafluoro antimony acetate Formulation 2 Carbon black 100 parts Solvent-soluble type 200 parts Polyester resin (Toyobo Co., Ltd. "Vylon") 200") Methyl ethyl ketone 2700 parts Example 2 A coating solution consisting of Formulation 3 was applied by dip coating onto the recording layer coated in Example 1 and heated at 90°C.
to form a protective layer. Dry film thickness, blackening density, scratch resistance test results and Nd-YAG laser (wavelength 1064nm output 10W on recording medium)
0.5Joule/cm ² ) The results of the imaging test by irradiation are summarized in Table 1. Prescription 3 Titanium Black 100 parts (“Titanium Black” manufactured by Mitsubishi Metals Co., Ltd.)
12S") 300 parts of solvent-soluble polyester resin ("Vylon 200" manufactured by Toyobo Co., Ltd.) 3600 parts of methyl ethyl ketone Example 3 A coating solution consisting of Formulation 4 was applied on the recording layer coated in Example 1 by dip coating. 90℃
to form a protective layer. Dry film thickness, blackening density, scratch resistance test results and Nd−
Table 1 summarizes the results of image forming tests performed by YAG laser (wavelength 1064 nm, output 10 W, 0.5 Joule/cm ² on the recording medium layer) irradiation. Formulation 4 Perylene Black 100 parts (BASF “Paliogen Black L0084”) Solvent-soluble polyamide 300 parts (Dainippon Ink Co., Ltd. “Laccamide”
5003'') Methanol 3600 parts Comparative Example A coating solution consisting of Formulation 5 was applied on the recording layer applied in Example 1 to form a protective layer. Formulation 5 Solvent-soluble polyester 100 parts (Toyobo Co., Ltd.) "Vylon 200") 900 parts of methyl ethyl ketone Dry film thickness, blackening density, scratch resistance test results and Nd-YAG laser (wavelength 1064nm output)
Table 1 summarizes the results of the image formation test using 10W irradiation of 0.5 Joule/cm ² ) on the recording medium.

[Table] Note 2) The scratch resistance test of the examples was conducted according to the following method. As shown in Fig. 3, a film consisting of a support 1, a recording layer 2, and a protective layer 3 is cut into 10 cm x 10 cm pieces, a piece of paper 5 with an area of 1 cm ² is placed on the coated surface, and the film is moved about 5 cm in the horizontal direction while applying a load 6. let After that, check the moved part for any damage. An experiment was conducted while applying a load, and the value of the load when the recording layer was scratched was evaluated as the scratch resistance of the protective layer using the following criteria. A: The recording layer will not be damaged under a load of 500g. B: The recording layer is not scratched under a load of 250g. C: Scratches occur under a load of 50g.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a laser recording film of the present invention, FIG. 2 is a schematic cross-sectional view of a recording device using the film of the present invention, and FIG. 3 is a diagram showing a measuring method for a scratch resistance test. . 1... Support, 2... Recording layer, 3... Protective layer,
4...Transfer image receptor.

Claims (1)

[Claims] 1. A recording medium layer consisting of a non-self-oxidizing binder, a highly light-shielding pigment that absorbs heat, and a heat ray absorber that has a strong absorption ability in the wavelength range of the laser light used for recording is provided on a transparent substrate. 1. A laser recording film characterized in that a protective layer comprising a thermoplastic polymer and a heat-absorbing pigment is provided on the recording medium layer.