Method for antimicrobially treating printed matter

Abstract

 A method for antimicrobially treating printed matter such as a notebook cover by forming an antimicrobial layer on an outermost surface of the printed matter.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a method for antimicrobially treating printed matter.

Prior Art

[0002] Printed matter such as a notebook cover is repeatedly touched with hands and might be contaminated by bacterium such as Escherichia coli, etc., which is sanitarily unfavorable. It is desirable to conduct an antimicrobial treatment to keep the printed matter clean. When such a treatment is applied to paper products, an antimicrobial agent is generally impregnated in the paper. In a case of printed paper, however, it has been a problem that an antimicrobial effect is insufficient because a surface of the paper is covered by a printing ink.

[0003] Accordingly, it is an aim of the present invention to provide a novel method for antimicrobially treating printed matter which can exhibit a sufficient antimicrobial effect and thus keep it clean.

SUMMARY OF THE INVENTION

[0004] According to the present invention, there is provided a method for antimicrobially treating printed matter in which a layer of an antimicrobial agent is formed on an outermost surface of paper material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Fig. 1 is a cross-sectional view of printed matter used in Example 1.

[0006] Fig. 2 is a cross-sectional view of printed matter used in Example 4.

[0007] Fig. 3 is a cross-sectional view of printed matter used in Example 5.

DETAILED DESCRIPTION AND THE PREFERRED EMBODIMENTS

[0008] The antimicrobial layer on the outermost surface of the paper material may be formed either by coating a paint containing a powdered antimicrobial agent therein or an aqueous solution or an aqueous suspension of the antimicrobial agent on the paper after printing of the paper is conventionally conducted in advance, or by printing the surface of the paper with a printing ink containing the powdered antimicrobial agent therein.

[0009] Materials to which the present invention is applicable include any repeatedly usable printed matter made of paper, cloth, plastics, glass and the like.

[0010] Using an antimicrobial metal such as silver or an organic compound e.g. a benzalkonium compound such as the chloride, a cetylpyridinium compound such as the chloride etc., a sparingly soluble phosphate may be intercalated or ion-exchanged to form an antimicrobial agent.

[0011] Preferably, about 2.5 to 5 parts by weight of the antimicrobial agent is added to 100 parts by weight of a paint, water or a printing ink. Further, it is more preferable to add thereto 5 to 10 parts by weight of wood vinegar liquid.

[0012] Although paints used herein include OP varnish (offset printing varnish), aquapack varnish, UV-OP varnish and the like, any kind of paints generally used for coating in the printing industry may be employed.

[0013] Coating is conducted by offset printing, offset rotary printing, photogravure printing and the like, which may be employed depending on material to be printed. It is also possible to coat using a suitable coater instead of printing.

[0014] According to the method of the present invention, a layer of the antimicrobial agent is formed on the outermost surface of the printed matter, which effectively affects bacterium absorbed on the printed surface.

[0015] The present invention will be described in detail in the following examples. However, these examples are intended to illustrate the invention and are not to be constructed to limit the scope of the invention.

Example 1

[0016] Using a printing ink of the following composition, a design 2 was printed on a surface of cardboard 1 used as a notebook cover.

pigment	23 (wt %)
synthetic resin	29
drying oil	25
petroleum solvent	18
film reinforcing agent	2
set-off preventing agent	1
drying agent and other solvent	2

[0017] Then, a mixture of 3.5 parts by weight of a powdered antimicrobial agent prepared by intercalating (ion-exchanging) a sparingly soluble phosphate with silver and 100 parts by weight of OP varnish having the following composition was coated by offset printing thoroughly on the printed layer thus obtained so as to form an antimicrobial layer 3.

synthetic resin	35 (wt %)
drying oil	28
high-boiling petroleum solvent	28
wax	9

[0018] The notebook cover thus treated showed the same appearance and suitability as a conventional one which had no antimicrobial layer.

[0019] The thus treated notebook cover and a conventional one, each having a size of 30 cm x 30 cm, were passed out to a hundred kindergarteners after their daily lesson who were allowed to rub one palm on the treated cover according to the present invention and the other palm on the conventionally printed cover. It was considered that a nearly equal amount of bacterium was absorbed on these two kinds of covers. These covers were kept two days and nights under conditions of humidity of 60 % and temperature of 25 °C. As a result, it was observed that an amount of bacterium absorbed on the conventional cover was seven times compared with the cover treated according to the present invention.

Example 2

[0020] Using an aquapack varnish of the following composition instead of the OP varnish, Example was repeated to prepare a printed notebook cover.

synthetic resin	40 (wt %)
isopropyl alcohol	4
ethyl alcohol	4
ammonia	1
water	51

[0021] The notebook cover treated according to the present invention exhibited the same effect as what was obtained in Example 1.

Example 3

[0022] Using UV-OP varnish of the following composition instead of the OP vanish, Example 1 was repeated to prepare a printed notebook cover.

acrylic oligomer	40 (wt %)
acrylic monomer	40
photo-initiator	10
synthetic wax	10

[0023] The notebook cover treated according to the present invention exhibited the same effect as what was obtained in Example 1.

Example 4

[0024] A design 5 was printed on cardboard 4 used as a notebook cover similarly to Example 1. An aqueous suspension containing 100 parts of water and 3 parts by weight of the same antimicrobial agent used in Example 1 was thoroughly coated on the printed surface thus obtained by means of a roll coater so as to form an antimicrobial layer 6.

[0025] Similarly to Example 1, the notebook cover thus treated showed the same appearance and suitability as a conventional one which had no antimicrobial layer.

[0026] An antimicrobial test was repeated similarly to Example 1 and yielded nearly the same result.

Example 5

[0027] Using a mixture of 100 parts by weight of the same printing ink and 3.5 parts by weight of the same antimicrobial agent used in Example 1, a design 8 was printed on the cardboard 7 which was also used in Example 1.

[0028] The notebook cover thus treated showed the same appearance and suitability as a conventional one which had no antimicrobial layer.

[0029] An antimicrobial test was repeated similarly to Example 1 and yielded nearly the same result.

Claims

1. A method for antimicrobially treating printed matter, wherein a layer consisting of or containing an antimicrobial agent is provided on an outermost surface of the printed matter.

2. A method for antimicrobially treating printed matter as claimed in claim 1 in which said layer is formed by coating a paint containing the powdered antimicrobial agent on the printed matter after printing.

3. A method for antimicrobially treating printed matter as claimed in claim 1 in which said layer is formed by coating a solution of the antimicrobial agent on the printed matter after printing.

4. A method for antimicrobially treating printed matter as claimed in claim 1 in which said layer is formed by coating a suspension of the antimicrobial agent on the printed matter after printing.

5. A method for antimicrobially treating printed matter as claimed in claim 1 in which said layer is formed by printing on a surface of material to be printed with a printing ink containing the powdered antimicrobial agent.

6. A method for antimicrobially treating printed matter as claimed in any preceding claim wherein the printed matter is of cardboard.

7. Antimicrobially-treated printed matter, wherein a layer consisting of or containing an antimicrobial agent is provided on an outermost surface of the printed matter.

Drawing