JP2001278285A - Paper for envelope, and envelope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new communication medium toy easily printing in color on an envelope. SOLUTION: On one face of a paper for an envelope, an ink jet recording layer suitable for full color printing formed by binding a porous pigment such as silica sol or alumina sol with a safe binding agent such as polyvinyl alcohol is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an envelope, and more particularly to an envelope capable of performing color printing by ink jet recording.

[0002]

2. Description of the Related Art Recent advances in computers have made it possible to display a screen in full color, and there has been a growing demand for outputting this screen as a hard copy. Actually, in the past, all documents in offices were almost black printing, but recently, it has been demanded that a large number of colors and figures can be used for accurate and prompt transmission of document contents. Colorization is progressing in all fields, and in the field of recording, colorization is also progressing not only in full color by ink jet recording but also in an electrophotographic method.

[0003] As various businesses become increasingly interdisciplinary, it is increasingly important for customers to promote their businesses.
There is direct mail as a means. Because direct mail has a large amount of information, so-called confidential postcards cannot be used in time, and sufficient information is usually enclosed in an envelope and sent to specified or unspecified customers. Due to postage costs, plastic film envelopes are frequently used to make the envelope as light as possible, but plastic products are being avoided from the viewpoint of environmental protection.

[0004]

To cope with such a situation, no countermeasure to be taken at present has been taken. Therefore, the present invention focuses on envelopes that have not been omitted in the past, and to obtain an envelope that can individually and colorly imprint a logo mark and an advertising image as well as a sender and a destination on this envelope. Assigned.

[0005]

Means for Solving the Problems When full-color ink jet recording is performed on envelope paper, it is possible to perform recording, of course, but the image is extremely poor and dull.
Inadequate for publicity purposes. The envelope is manufactured by folding, molding, and gluing an envelope sheet into the shape of an envelope.
In use, after writing necessary items on the envelope surface, the opening is sealed with glue or an adhesive tape. As described above, envelopes have processes that are not required for conventional ink jet recording paper, such as folding, gluing, and sealing of openings. Therefore, a recording layer that considers only recording suitability is not sufficient. For example, when a recording layer is provided on envelope paper to provide color ink jet recording suitability, if the strength of the coated recording layer is insufficient, paper powder will fall from the folded portion, and the folding machine will be soiled. Depending on the state of adhesion between the glue for gluing and the coated surface, there is a problem that the bonded surface is peeled off during handling or peeled off from the coated surface.

As a result of intensive studies in such a state, colloidal silica or colloidal alumina is mainly used as a pigment of a coating layer for forming an ink jet recorded image, thereby satisfying recording suitability, folding suitability and gluing suitability. The inventors have found that the present invention has been completed and completed the present invention.

That is, the object of the present invention has been solved by providing a coating layer having a suitability for full-color ink jet recording using colloidal silica or colloidal alumina as a main pigment on a recording surface such as an address of an envelope paper.

The main pigment of the coating layer used in the present invention is
Known examples include colloidal silica (silica sol) and colloidal alumina (alumina sol). These contain fine colloidal particles of silica or alumina, and when this sol is dried, it has the ability to form a film without any other adhesive. However, in the present invention, another adhesive (binder) is required. Although the binder is not particularly limited, the amount of the binder is important, and the binder is required to be 20 to 50 parts by weight, which is much larger than usual, based on 100 parts by weight of colloidal silica or colloidal alumina.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Pigments usable in combination with colloidal silica or colloidal alumina include calcium carbonate, clay, silica, and the like used in the field of ink jet recording.
Alumina and the like, the amount of which is determined in consideration of recording suitability, gluing suitability, and moldability.

As the binder, various water-soluble polymers and thermoplastic resin emulsions can be used. Among them, polyvinyl alcohol or a modified product thereof, vinyl acetate emulsion has good binding properties between paper and pigment, is industrially available in various grades, is inexpensive, has high safety, and is used after use. It is also preferable in terms of recycling.

Hereinafter, the present invention will be described in detail with reference to examples. In the following Examples and Comparative Examples, "parts" and "%" represent parts by weight of solid content and% by weight of solid content unless otherwise specified.

[Examples 1 to 4] The degree of Stechcht sizing was 2
Colloidal silica 10 as pigment on white high quality paper for 5 seconds
0 parts, polyvinyl alcohol (PVA1) as binder
17 Kuraray Co., Ltd.), 10 parts of styrene butadiene latex, and 10 parts of diallyldimethylammonium chloride as an ink fixing agent were mixed to obtain a 20% concentration paint. The recording layer after drying this coating material has a coating amount of 6, 10,
Coating was performed with a blade coater so as to obtain 15,20 g / m ² to obtain envelope sheets for inkjet recording of Examples 1 to 4.

[Examples 5 to 8] The coating amount of the dried recording layer was 8, 12, 17, 22 g / m ^{2 in the same} manner as in Examples 1 to 4, except that the colloidal silica was replaced with alumina sol.
Are obtained.

[Comparative Examples 1 to 4]
100 parts of amorphous silica (average particle size: 5.5 μm) as a pigment, 15 parts of polyvinyl alcohol (manufactured by Kuraray PVA117) as a binder, and 10 parts of diallyldimethylammonium chloride as an ink fixing agent were added to white high-quality paper for 5 seconds. The mixture was added and mixed to obtain a paint having a concentration of 20%. The coating amount of the recording layer after drying this paint was 7, 11, 16, 2
Coating was performed with a blade coater so as to be ² g / m ² , to thereby obtain inkjet recording envelope papers of Comparative Examples 1 to 4.
Comparative Example 5 A commercially available white envelope was used as inkjet recording paper.

Each of the sheets prepared in Examples and Comparative Examples was evaluated as follows, and the results are shown in Table 1.

(Printability) Printability is determined by a commercially available inkjet printer EM-900C (manufactured by Seiko Epson).
Was evaluated as described below. A solid image of ink-absorbing red and green was printed, and evaluation was made based on the degree of bleeding at the boundary with a blank paper portion. ：: The boundary is clear and no bleeding is observed. ：: The boundary is slightly unclear but no bleeding is observed. Δ: The boundary is unclear and bleeding is observed. X: The boundary is unclear and Noticeable bleeding

Each solid image was printed for black, cyan, magenta and yellow, and after being left for one day, the print density of each image portion was measured with a reflection densitometer (RD914 manufactured by Macbeth). The evaluation was made based on the sum of the measured values. ◎: Total of 4 colors is 6 or more ○: Total of 4 colors is 5 to 6 △: Total of 4 colors is 4 to 5 ×: Total of 4 colors is less than 4

[0018] The coated surface of the envelope paper that has aptitude create folded and rated the surface state at the time of folding in such a manner that on the surface. ：: Easy bending, good bent end face △: Rough end face rubbed with fingers during bending ×: Paper powder falls from end face during bending

Gluing Suitability A glue was glued in the form of a standard envelope using an aqueous glue, and left for one day to evaluate the releasability. ：: Easy to glue, not peeling by hand one day later. Easily peels off

The envelope paper thus prepared was molded into an envelope paper, sealed with a cellophane tape, and one day later, the state of adhesion was evaluated. ：: The tape adheres tightly and can be sealed. 部分: Partially peels off and some of the adhesion is bad. ×: The coating layer adheres to the tape and peels off immediately.

[0021]

[Table 1]

[0022]

By using the envelope of the present invention, the user can not only print the address and sender's name of the envelope in color using a color ink-jet printer which is inexpensive, but also print the logo mark and other senders. The color output of the impressive favorite design has a novel effect of becoming a new transmission medium beyond the conventional concept of an envelope.

Claims (3)

[Claims] 1. An envelope paper comprising an envelope paper provided with a coating layer having a suitability for full-color ink jet recording using colloidal silica or colloidal alumina as a main pigment on a recording surface such as a destination. 2. The envelope paper according to claim 1, wherein the ratio of the pigment to the binder is 20 to 50 parts of the binder with respect to 100 parts of the pigment in terms of the weight ratio of the solid content. 3. An envelope obtained by molding and gluing the envelope paper according to claim 1 or 2 so that the coated surface is the surface.