JP2003098715A - Gloss protective layer structure - Google Patents

Abstract

(57) [Problem] To provide a glossy protective layer structure capable of forming a high-quality image in which a recorded image shows a clear and specular gloss, and has no unevenness due to the image. An electrophotographic transfer sheet having a sheet-like base material and a toner receiving layer formed on at least one surface thereof and containing a thermoplastic resin as a main component is used. Provided with a protective film layer,
A toner image is formed on the toner receiving layer by a dry electrophotographic method, the toner image is fixed to a surface layer of the toner receiving layer by heat fixing, and a protective film layer is further formed on the image formed toner receiving layer. It is characterized by being provided. Further, the surface of the protective film layer,
The unevenness due to the toner is 5 μm or less, and JIS
The glossiness at 20 degrees based on Z8741 is preferably 80% or more.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalog which is protected by a protective film layer after creating images, characters and the like,
The present invention relates to a glossy protective layer structure having a laminated structure of paper sheets such as a cover and a book cover.

[0002]

2. Description of the Related Art Paper sheets such as catalogs and covers have conventionally been used to form images and characters by printing and to be used for predetermined purposes. Depending on these applications, the printed surface may be protected by a film for protection from water wetting and dirt, or for imparting gloss. In order to deal with this, there are overprinting, vinyl drawing, press coating, film attachment, etc., and it is necessary to perform surface treatment after printing.

On the other hand, recently, information is frequently changed, and the number of systems capable of outputting variable information such as changing information one by one is increasing, and there is a demand for speeding up print output. On-demand printing is used as a printing method suitable for this. Furthermore, UV varnish processing has become possible online for protective film layer processing.

As the equipment used for on-demand printing, there are usually an electrophotographic system and an inkjet system.
An electrophotographic method using toner is mainly used for output including images. When an image is formed by this method, when toners corresponding to cyan, magenta, yellow, and black are stacked and fixed on the paper, unevenness occurs, and when a protective layer is provided on the surface, unevenness remains and the appearance is poor. Therefore, there is a problem that the commercial value is reduced.

When a toner image is formed by a dry electrophotographic method, the height of the toner after fixing varies depending on the color image density and hue. For example, in JP-A-63-92965, unevenness of about 10 to 100 μm is used. Is described as occurring. In addition, according to the observation result of “Electronic Photography Society, Vol. 35, No. 2, (1996) p132”, the maximum is 2
It is described that it becomes 7 μm. In particular, when using coated paper, it is known that the toner melted by heating and fixing melts each color of cyan, magenta, yellow, and black on the coated paper, so that irregularities are easily noticeable.

The surface provided with the protective film layer on the characters and images formed by the toner has unevenness in the high image density portion, and when the high quality image is handled, the unevenness of the glossy surface of the protective film layer is generated. Since it looks more prominent, its improvement has been desired.

[0007]

In general, high-quality paper is mainly used for toner image formation, but in a high-density image portion where a large amount of toner is used, toner is stacked and compared with a non-image portion. A step having a height of about 30 μm is formed. In order to avoid this, a toner receiving layer having good compatibility with the toner is provided on the sheet-shaped substrate, so that an image surface in which the toner height after fixing is 5 μm or less as compared with the non-image portion can be formed. .

Further, the present inventor uses a glossy protective layer structure having a protective film layer formed thereon to reduce the unevenness of the image surface to such an extent that it does not pose a problem when the unevenness is visually observed. I found that. Further, they have found that by forming a protective film layer for protection from water wetting and stains and for imparting gloss after forming a toner image, it is possible to prevent deterioration of quality due to unevenness of the toner, and completed the present invention. It was

The present invention has been made in view of the above-described problems, and a recorded image is clear and has a specular gloss, and a gloss that enables high-quality image formation without unevenness caused by the image is formed. It is to provide a protective layer structure.

[0010]

Means for Solving the Problems A glossy protective layer structure according to the present invention comprises a sheet-shaped base material and a toner-receiving layer formed on at least one surface of the base material and containing a thermoplastic resin as a main component. A transfer sheet for electrophotography having is used, in which a protective film layer is provided on the toner receiving layer, a toner image is formed on the toner receiving layer by a dry electrophotographic method, and the toner image is a thermal image. It is characterized in that it is fixed to the surface layer portion of the toner receiving layer by fixing, and a protective film layer is provided on the toner receiving layer on which the image is formed.

On the surface of the protective film layer, unevenness due to the toner is 5 μm or less, and JIS Z 8 is used.
It is preferable that the 20 degree glossiness based on 741 is 80% or more.

[0012] In other words, in order to solve the above-mentioned problems, the present invention provides a glossy protective layer constitution in which a protective film layer is provided after an image is formed on an electrophotographic transfer sheet having a toner receiving layer, whereby It is possible to obtain a surface having no unevenness even in the density image portion.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In order to reduce the image height of the toner after dry toner fixing to 5 μm or less, the electrophotographic transfer sheet has a toner receiving layer having a high affinity for the toner, and after the toner image is formed, By forming the protective film layer on the protective film layer, it is possible to obtain a glossy protective layer structure which is protected from water wetting and stains and has gloss.

The sheet-like base material of the electrophotographic transfer sheet which can be used in the present invention is not particularly limited. For example, an acidic paper having a paper making pH of about 4.5 and an alkaline filler such as calcium carbonate as a main component. Including, papermaking pH is about 6
A paper substrate such as a neutral papermaking machine having a weak acidity of about 9 to a weak alkalinity of about 9 is used. A paper substrate having a highly smooth surface due to its surface glossiness and unevenness is preferred. As a papermaking method, a general long-mesh multi-cylinder type, circular-net single-cylinder type, Yankee type, or the like is appropriately used. Depending on the application, coated paper, cast coated paper, synthetic paper, non-woven fabric, synthetic resin film, synthetic resin film laminated sheet-like base material, multi-layered structure in which polyolefin resin is melt-extruded and laminated on one or both sides of the paper substrate. The sheet-shaped base material can also be used.

In the toner receiving layer on the surface of the electrophotographic transfer sheet used in the present invention, a resin component having a high affinity with the toner and having a viscoelasticity compatible with the molten toner at the toner fixing temperature is mainly formed. ing. For example, polyester resin, styrene-acrylic acid ester resin,
A styrene-methacrylic acid ester-based resin, a polyacetal resin or the like can be used, but it is preferable to use a resin of the same type as the main resin constituting the toner as a main component. The glass transition point is preferably 55 to 75 ° C. in order to improve the compatibility with the toner in the temperature characteristics of the resin used in the toner receiving layer and to keep the toner height on the surface at 5 μm or less. When the glass transition temperature is less than 55 ° C, electrophotographic transfer sheets may be laminated when not in use and may be easily fused with the back surface to block when stored at high temperature. On the other hand, when the temperature exceeds 75 ° C., the image height of the toner becomes higher than 5 μm, and when the protective film layer is laminated, unevenness becomes remarkable, which is not preferable.

The toner receiving layer of the present invention may contain a pigment, a release agent, a conductive agent, a fluorescent whitening agent, a colorant and the like. The toner affinity resin component in the toner receiving layer is 80
It is desirable that the content is at least mass%. 2 from toner transferability
It is desirable that the surface electric resistance value of the electrophotographic transfer sheet that has been conditioned under the environment of 3 ° C. and 50% is in the range of 1 × 10 ⁹ Ω to 1 × 10 ¹³ Ω.

As a method for providing the toner receiving layer on the sheet-shaped substrate, a generally known coating apparatus can be used, for example, a reverse roll coater, a bar coater, a curtain coater, a die coater, a gravure coater or the like. Selected and used. After coating, it may be subjected to a smoothing treatment if necessary, and this smoothing treatment can be carried out by a smoothing treatment device such as a normal super calender, gloss calender or soft calender.

Using the electrophotographic transfer sheet of the present invention,
After forming the dry toner image, UV protection varnish treatment or lamination treatment is performed in-line or off-line to provide a protective film layer to obtain a glossy protective layer structure. The basic composition of the UV curable varnish consists of reactive oligomers, reactive monomers, sensitizers and additives. As reactive oligomers, acrylic acid esters of polyhydric alcohols, epoxy acrylates, urethane acrylates, polyester acrylates, polyether acrylates, acrylate alkyds,
One type or two or more types are appropriately selected and used from melamine, acrylate and the like. The crosslinkable monomer is appropriately selected from monoacrylate, diacrylate, triacrylate and the like. The sensitizer can be selected from anthraquinone, benzophenone, 2-ethylanthraquinone and the like.

The coating of the UV-curable varnish is performed by a roll coater coating, followed by surface treatment and curing with a UV lamp. Alternatively, after the image is formed on the transfer sheet for electrophotography, the UV-curable varnish is offline on the surface. Coating and surface treatment. It is selected from an off-line laminating treatment, a method of melt-extruding polyethylene or polypropylene and treating the surface, a method of laminating a polyethylene or polyethylene terephthalate film with an adhesive, and the like. From the viewpoint of gloss, smoothness and transparency after the surface treatment, surface treatment with a UV curable varnish is preferable.

[0020]

EXAMPLES Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, "part" and "%" in Examples and Comparative Examples are
Unless otherwise specified, "mass part of solid content" and "mass%" are shown.

Example 1 Commercially available coated paper for printing OK top coat 157 g / m ² (manufactured by Oji Paper Co., Ltd.)
Polyester resin (trade name: TP
220, number average molecular weight Mn: 16000, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the dry mass is 10 g using a gravure coater.
After coating so as to be / m ² , the moisture content was adjusted to be 4.5% to prepare an electrophotographic transfer sheet having a basis weight of 165 g / m ² .

Using a transfer sheet for electrophotography, IPSiO
  Image recording using Color 2100 (manufactured by Ricoh)
After recording, 5g of UV curable varnish coating solution with the following composition
/ M ^TwoCoated with a slit bar to achieve high pressure mercury UV
Irradiate with an irradiation lamp (80W / cm) to cure and protect
A film layer was formed. UV curable varnish used here
Cloth liquid is polyester acrylate 50 parts, accretion
Tomonomer 20 parts, benzophenone 5 parts as a sensitizer
used.

The surface of the glossy protective layer structure thus obtained had specular glossiness and exhibited good water resistance. The maximum height Rmax of surface irregularities is JIS K 06
01-based method, the result is 5 μm, 2
The 0 degree glossiness was 80%.

Example 2 An electrophotographic transfer sheet was prepared in the same manner as in Example 1 except that commercially available cast paper mirror coat platinum 157 g / m ² was used as the sheet-shaped substrate, and IPSiOColor 2100 ( (Ricoh)
An image was formed with the above, and the surface was gloss-finished with a rotary drum dryer heated to 100 ° C., and then a protective film layer was formed with a UV curable varnish. The surface of the gloss protective layer structure thus obtained had specular gloss and had good water resistance. The maximum height Rmax of the surface irregularities was 1 μm, and the 20 degree glossiness was 88%.

Example 3 An image was formed in the same manner as in Example 1 except that a digital coated paper gloss type (manufactured by Fuji Xerox Co., Ltd.) was used as the transfer sheet for electrophotography, and the surface was treated with a UV curable varnish. To form a protective film layer. The surface of the gloss protective layer structure thus obtained had specular gloss and had good water resistance. The maximum height Rmax of the surface irregularities was 4 μm, and the 20 degree glossiness was 93%.

[Comparative Example 1] JD was applied to a transfer sheet for electrophotography.
Example 1 except that a coat (manufactured by Fuji Xerox Co., Ltd.) was used.
An image was formed in the same manner as in (1) and the surface was treated with a UV curable varnish to form a protective film layer. Although the gloss protection layer structure thus obtained has good water resistance, its surface is glossy, but unevenness is observed along the contour of the image portion, and the surface is lacking in quality. Maximum height of surface irregularities Rmax
Was 15 μm, and the 20 degree glossiness was 78%.

[Comparative Example 2] An image was formed in the same manner as in Example 1 except that a digital coated paper gloss type (manufactured by Fuji Xerox Co., Ltd.) was used as the transfer sheet for electrophotography, and a protective film layer was formed on the surface thereof. Nakatsuta. The surface of the electrophotographic transfer sheet thus obtained had glossiness, but the glossiness was lower than that of the varnish-treated surface. The maximum height Rmax of the surface irregularities was 5 μm, but the 20 degree glossiness was 5
It was 6%.

[0028]

EFFECTS OF THE INVENTION The glossy protective layer structure according to the present invention is very useful in practice because a recorded image is clear and exhibits mirror gloss, and a high-quality recorded image having no unevenness caused by the image is obtained. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gloss protective layer structure of the present invention.

[Explanation of symbols]

1: Gloss protective layer structure 2: Sheet-shaped substrate 3: Toner receiving layer 4: Toned toner image 5: Protective film layer

Claims (2)

[Claims] 1. A transfer sheet for electrophotography, comprising a sheet-shaped substrate and a toner-receiving layer formed on at least one surface thereof and containing a thermoplastic resin as a main component, the toner-receiving layer being used. In a glossy protective layer structure having a protective film layer provided thereon, a toner image is formed on the toner receiving layer by a dry electrophotographic method, and the toner image is fixed on the surface layer portion of the toner receiving layer by heat fixing, Furthermore, a glossy protective layer structure characterized in that a protective film layer is provided on the image-formed toner receiving layer. 2. The surface of the protective film layer has an unevenness of 5 μm or less due to the toner, and JIS Z 87
The glossiness of 20 degrees based on 41 is 80% or more.
The glossy protective layer structure described in [4].