JPH0422349Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to an electrophotographic image-receiving material, and more particularly to an electrophotographic image-receiving material from which reproduced images with improved sharpness can be obtained. [Background of the invention] Generally, in electrophotography, toner is attached to the electrostatic latent image area on a photoreceptor to form a visible image, and this visible image is further transferred to an image receiving paper such as paper, and then heated, etc. It has been established and a copy has been obtained. Nowadays, electrophotographic copying machines are widely used, and an increasing number of users desire improved image quality, particularly sharpness. For this reason, efforts have been made to develop toner particles with finer toner particles, toners with a uniform particle size distribution, and transfer methods that prevent transfer misalignment between the photoreceptor and image receiving paper, but the current situation is that this is still not sufficient. It is. [Purpose of the invention] In view of the above-mentioned conventional circumstances, an object of the present invention is to provide an image-receiving material for electrophotography suitable for obtaining high-quality copied images with high sharpness. [Structure of the invention] The above object of the invention is achieved by providing an electrophotographic image-receiving material in which the toner image-receiving layer mainly consists of a hydrophilic polymeric material layer. [Specific structure of the invention] Hydrophilic polymeric substances used in the invention include, for example, gelatin, proteins, graft polymers of gelatin and other polymeric substances, synthetic hydrophilic polymeric substances, etc. In particular, gelatin is preferred. Gelatin includes lime-processed gelatin, acid-processed gelatin, Bull, Soc, Sci, Phot, Japan.No.
16, p. 30 (1966) may be used, and gelatin hydrolysates and oxygen-decomposed products may also be used. Examples of gelatin derivatives include gelatin with acid halides,
Those obtained by reacting various compounds such as acid anhydrides, isocyanates, bromoacetic acids, alkanesultones, vinylsulfonamides, maleimide compounds, polyalkyleonoxides, and epoxy compounds are used. Specific examples are U.S. Patent No. 2614928, U.S. Patent No. 3132945, U.S. Patent No. 3186846,
British Patent No. 3312553, British Patent No. 861414, British Patent No. 1033189,
It is described in No. 1005784, Special Publication No. 42-26845, etc. Preferred proteins include albumin and casein; preferred cellulose derivatives include hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfate; and preferred sugar derivatives include sodium alginate and starch derivatives. The above-mentioned graft polymer of gelatin and other polymers includes gelatin and derivatives such as acrylic acid, methacrylic acid, their esters and amides, and single (homo) or copolymers of vinyl monomers such as acrylonitrile and styrene. A grafted material can be used. In particular, polymers which are compatible to some extent with gelatin, such as acrylic acid, acrylamide, methacrylamide,
Graft polymers with polymers such as hydroxyalkyl methacrylates are preferred. Examples of these are U.S. Pat.
It is described in issues such as No. 2956884. Typical synthetic hydrophilic polymer substances are single or copolymers such as polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, and polyvinylpyrazole. For example, West German Patent Application (OLS) No. 2312708, U.S. Patent No. 3620751
No. 3879205 and Special Publication No. 7561 of 1973. By including fine particle powder (hereinafter referred to as a matting agent) in the hydrophilic polymer material layer, the transferability of the toner can be improved. For example, matting agents with an average particle size of 1 to 20 μm are suitable for this purpose. The amount of matting agent used is preferably 5 to 1000 mg per 1 g of the hydrophilic polymeric substance. If a large amount of matting agent is used, the matting agent will easily fall off during toner transfer, causing a drop in image quality due to missing toner images, and the falling matting agent will be collected together with the recovered toner, gradually reducing the matting agent content in the toner. becomes high, leading to a decrease in copy density. As matte agents, British Patent No. 1055713, US Patent No. 1939213, US Patent No. 2221873, US Patent No. 2268662,
Same No. 2322037, No. 2376005, No. 2391181, Same No.
No. 2701245, No. 2992101, No. 3079257, No.
No. 3262782, No. 3443946, No. 3516832, No.
No. 3539344, No. 3591379, No. 3754924, No.
Organic matting agents described in No. 3767448, West German Patent No. 2529321, British Patent No. 760775,
1260772, US Patent No. 1201905, US Patent No. 2192241,
Same No. 3053662, No. 3062649, No. 3257206, Same No.
No. 3322555, No. 3353958, No. 3370951, No.
No. 3411907, No. 3437484, No. 3523022, No. 3411907, No. 3437484, No. 3523022, No.
No. 3615554, No. 3635714, No. 3769020, No. 3615554, No. 3635714, No. 3769020, No.
Inorganic matting agents described in No. 4021245, No. 4029504, etc. can be preferably used. Further, it is preferable to include a hardening agent in the hydrophilic polymer material layer for the purpose of increasing the film strength. The amount of hardening agent used depends on the type of hardening agent, but is suitably 3 to 150 mg per gram of hydrophilic polymeric substance. As a hardening agent, aldehyde type, aziridine type (for example, PB Report, 19921, US Patent No.
2950197, 2964404, 2983611, and 3271175, and those described in Japanese Patent Publication No. 46-40898 and Japanese Patent Application Laid-Open No. 50-91315), isoxazole type (e.g. , described in U.S. Patent No. 331609), epoxy systems (for example, described in U.S. Patent No. 3047394, West German Patent No. 1085663, British Patent No. 1033518, and Japanese Patent Publication No. 1983-35495) ), vinyl sulfone type (e.g.
PB Report 19920, West German Patent No. 1100942, same
No. 2337412, No. 2545722, No. 2635518, No.
No. 2742308, No. 2749260, British Patent No. 1251091,
Those described in the specifications of Japanese Patent Application No. 45-54236, No. 48-110996, U.S. Patent No. 3539644, and U.S. Patent No. 3490911)
No. 27949, U.S. Patent No. 3640720), carbodiimides (for example, U.S. Pat. Gansho 49-15095
(described in the specification), triazine-based (e.g.
West German Patent No. 2410973, West German Patent No. 2553915, US Patent No.
3325287, those described in JP-A-52-12722), polymer type (for example, British Patent No.
822061, U.S. Patent No. 3623878, U.S. Patent No. 3396029,
Specifications of No. 3226234, Japanese Patent Publication No. 47-18578,
18579 and 47-48896),
In addition, maleimide-based, acetylene-based, methanesulfonic acid ester-based, and N-methylol-based hardeners can be used alone or in combination. Useful combination techniques include, for example, West German Patent No. 2447587;
No. 2505746, No. 2514245, U.S. Patent No. 4047957
No. 3832181, specifications of 3840370, JP-A No. 48-43319, JP-A No. 50-63062, JP-A No. 52-127329
Examples include combinations described in Japanese Patent Publication No. 48-32364. Surfactants such as alkylbenzene sulfonates, saponins, alkyl succinates, and the like may optionally be included in the hydrophilic polymer layer, if necessary. Substrates used in the present invention include, for example, paper such as pulp paper and coated paper, paper laminated with α-olefin polymers (polyethylene, polypropylene, ethylene/butene copolymer, etc.) on a paper base, and α-polyolefin polymers. Suitable materials include synthetic films made of , cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyamide, etc., and synthetic paper. In the present invention, the hydrophilic polymer material layer can be applied directly or after treating the substrate surface with corona discharge, ultraviolet irradiation, etc. as necessary, or 1 to improve properties such as wear resistance, friction properties, anti-halation properties, etc.
It may be applied through more than one subbing layer. These layers can be applied using any of various known methods. As shown in the accompanying drawings, the electrophotographic image-receiving material 1 according to the present invention has, for example, a hydrophilic polymer material layer 3 for receiving toner on a substrate 2, and has a high toner transfer property. It is suitable for obtaining high-quality images with very high sharpness, with little deformation or thickening of the image lines during heat fixing. [Examples] Hereinafter, specific examples of the present invention will be described in detail, but the present invention is not limited to these embodiments. Example 1 Gelatin solutions A to G having the compositions shown in Table 1 were coated on art coated paper with a basis weight of 80 g/m ² so that the amount of gelatin applied was 2.0 g/m ² , and dried. Materials A-1 to G-1 were produced.

[Table] Electrophotographic copying machine U- manufactured by Konishiroku Photo Industry Co., Ltd.
Copying was done using Bix1810MR. That is, image receiving materials A-1 to G-1 and comparison (1) are placed in the paper feed section.
Set a piece of paper without a gelatin layer,
A resolution chart of 1, 3, 5, 7, 10, and 15 lines/mm and a solid black image were placed on the document table, and the surface temperature of the heat fixing roller was set at 115°C. The results of the resolution and solid black density of the copied image are shown in Table 2. In Table 2, the vertical direction refers to the case where the resolution chart is parallel to the scanning direction of the light source, and the horizontal direction refers to the case where the resolution chart is perpendicular to the scanning direction of the light source. say if it is written. Also, like the image receiving materials A-1 to G-1, the weight is 80
Coating liquids with the compositions shown in Table 1B were applied to art coated paper of g/ ^m2 so that the amount of polyvinyl alcohol applied was 2.0g/ ^m2 , and dried to produce image-receiving materials H to K. , Copying was performed in the same manner, and the resolution and solid black density of the copied image were determined. However, the resolution chart is 3, 4, 5, 6, 7, 8,
9, 10 and 15 lines/mm were used. The results are shown in Table-2.

[Table] Next, weigh 80 in the same way as image-receiving materials A-1 to G-1.
g/ ^m2 art coated paper with a gelatin amount of 2.0g/ ^m2.
Image-receiving materials L to N were prepared by coating and drying, and copies were made in the same manner as for comparison image-receiving materials H to K to determine the resolution and solid black density of the copied images. The results are shown in Table-2.

【table】

【table】

[Table] From the results in Table 2, the resolution in the horizontal direction is 3 to 5 lines/mm in the comparison, while the resolution in the present invention is 7 lines/mm.
It can be seen that the solid black image density is also high and the image quality is good. Example image receiving material sample C- containing gelatin as a binder
It can be seen that the comparative image-receiving material samples H to K, which do not contain gelatin, are inferior to Samples No. 1 to G-1 in both resolution and solid black density. Comparative image-receiving material samples L to N containing more than 1000 mg of matting agent per gram of hydrophilic polymeric material resulted in a decrease in image quality, and furthermore, it was observed that the matting agent fell off from the surface of the copy. Example 2 The deformation of toner during heat fixing was investigated using the comparative image receiving paper of Example 1 and the image receiving material G-1 of the present invention. That is, with respect to the line width (0.5 mm) of the toner image on the image receiving paper before heat fixing, the change in line width after heat fixing was determined and is shown in Table 3.

[Table] From the results in Table 3, it can be seen that in the comparative image-receiving paper, the toner diffused during heat fixing, thickening the image lines and lowering the resolution. In contrast, in the image receiving material of the present invention, there is almost no thickening of the image line, and it can be seen that good resolution can be obtained. Example 3 The above-mentioned first polyethylene laminated paper was prepared by laminating a 20 μm thick polyethylene layer containing 13% titanium oxide on the first side of an inner paper with a basis weight of 75 g and a 18 μm thick polyethylene layer on the other second side. The gelatin solutions A, B, C, E, and G of Example-1 were applied to the surfaces of the image-receiving materials A-2, B-2, and C-2, respectively, so that the amount of gelatin applied was 2.0 g/m ² and dried. ，
E-2 and G-2 were produced. A test was conducted in the same manner as in Example 1 using a comparison image-receiving paper in which no gelatin layer was provided on the polyethylene laminate paper and the image-receiving material of the present invention described above. Note that the surface temperature of the heat fixing roller was changed from 115°C to 100°C. The results are shown in Table 4.

【table】

[Table] * When the toner on the image surface was rubbed strongly, it was observed that it came off.
From the results in Table 4, the image receiving material of this invention is heated to 100°C.
It can be seen that both the resolution and the solid black density are good. In addition, at 115℃, both the comparison paper and the paper of the present invention had pressure lines caused by the roller.
When the temperature was lowered to 100°C, no deformation of the paper was observed.
When the temperature was lowered to 100°C, toner was observed to come off in the comparative product, but in the product of the present invention, no toner came off at all, and it can be seen that the adhesion between the toner and the image-receiving material is good. Example 4 In the same manner as in Example 1, coating liquids having the compositions shown in Table 5 were applied to art coated paper weighing 80 g/m ² so that the amount of gelatin applied was 2.0 g/m ² , and dried. , image-receiving materials O to S were prepared, and copies were made in the same manner as in Example-1. The black density of the 5 lines/mm portion in the horizontal direction of the resolution chart of the obtained copy image was measured using a microdensitometer. The results are shown in Table-6.

【table】

[Table] As is clear from the results in Table 6, samples containing matting agents in a range of 5 to 1000 mg per gram of hydrophilic polymeric material have excellent resolution.

[Brief explanation of drawings]

The accompanying drawing is a sectional view showing an embodiment of the electrophotographic image receiving material according to the present invention. 1... Image receiving material for electrophotography, 2... Substrate, 3...
...Hydrophilic polymer material layer.

Claims (1)

[Scope of utility model registration request] An image-receiving material for electrophotography, characterized in that the layer for receiving a toner image contains a hydrophilic polymeric substance containing at least gelatin, and contains a matting agent in an amount of 5 to 1000 mg per gram of the hydrophilic polymeric substance.