JPH0511573Y2 - - Google Patents

Description

[Detailed Description of the Invention] (A) Field of Industrial Application The present invention relates to a tack sheet having a thermosensitive color recording layer on one side of the paper and a thermal delayed tack layer on the other side.

(B) Problems to be solved by the prior art and the invention A thermosensitive coloring layer, which is usually colorless or light colored and develops color when heated, is applied to thermosensitive recording paper on a paper support for letters, numbers, designs, etc.
If symbols, patterns, etc. are thermally recorded and then affixed to an item, such as when attaching a barcode label for a POS system to a product, currently, a permanent tack process is applied to the back side of thermal recording paper and release paper or release paper is used. Heat-sensitive tack paper with (release paper) temporarily attached is used.

Permanent tack paper, which requires such release paper or release paper, has poor workability and productivity when attached as labels to items on factory lines, and is expensive due to the need for release paper or release paper. There are problems such as.

(C) Means for Solving the Problems The present invention is generally non-adhesive to the back side of thermosensitive recording paper, and therefore does not require release paper or release paper, is activated under heat to generate tack, and is not adhesive after cooling down. It is an object of the present invention to solve the above problems at once by providing a heat-sensitive tack paper provided with a thermal delayed tack layer that provides long-lasting tack.

Hot-melt adhesives are known as adhesives that are activated by heating, but these are activated only at high temperatures and are deactivated when the temperature drops to room temperature, so they must be applied at high temperatures when pasting them to articles. It is necessary to thermally press the entire label onto the object, and when applied to thermal recording paper, the entire surface becomes thermally colored, making it impractical.

Thermal delayed tack type adhesives are characterized by being activated when heated and maintaining tack and not deactivated even when the temperature drops to room temperature. Since the tack can be revealed by heating with hot air or infrared rays (heat rays), and then pressed onto the article with a low-temperature object after a while, the thermal fog on the thermosensitive coloring layer side is gradually reduced, making it practical.

However, even a slight color fog can cause misreading or malfunction when applied to bar code labels, for example, so color fog must be prevented as much as possible.

Therefore, the present invention provides a heat-sensitive tack paper having a structure that particularly prevents such slight color fogging.

This slight coloring fog is caused by the thermal
This occurs most often when heating and activating the delayed tack layer side, so in this invention,
A layer containing micro hollow spherical particles and/or a porous pigment as a main component was provided between the thermosensitive coloring layer and the support (paper) and/or between the support (paper) and the thermal delayed tack layer.

This also made it possible to prevent slight coloring fog in the heat-sensitive coloring layer.

Microscopic hollow particles include expanded thermally expandable microspheres (e.g., manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., manufactured by Kemanode), glass microscopic hollow spherical particles (e.g., manufactured by 3M, manufactured by Grabber Bell), Examples of porous pigments include aluminosilicate-based micro hollow spherical particles (manufactured by Nippon Filite Co., Ltd.), hollow latex-based organic plastic pigments (manufactured by Rohm & Haas), and urea-formaldehyde resin-based organic pigments (e.g., Civer-Geigy, Mitsui Higashi). (manufactured by Pressure Chemical Co., Ltd.), shirasu soil produced in southern Kyushu, etc. are useful in the present invention.

The thickness of this layer is determined in the range of several microns to several tens of microns depending on the purpose, application, and configuration.

In the present invention, a barrier layer may further be provided below and in contact with the thermal delayed tack layer. The barrier layer is a layer that prevents the heat-activated adhesive from penetrating into the support (paper) side and reducing the effective adhesive amount.

This layer may be, for example, a layer mainly consisting of a mineral pigment and a polymeric binder as proposed in JP-A-61-2783.

In order to manufacture the tack sheet of the present invention, it is practical to apply each layer on the surface of paper as a support using an aqueous coating, and dry it by heating within a range that does not cause color development or thermal activation. Then, it can be directly wound into a roll without a release paper.

In the present invention, the heat-sensitive coloring layer includes any layer based on any known principle, and is not particularly limited. A heat-sensitive coloring recording layer composed of multiple layers, for example, a heat-sensitive material coating layer + a pigment layer, is also considered to be one layer.

It is also the intention of the present invention to add a protective layer to the example diagrams described in this application to prevent the heat-coloring pattern formed on the heat-sensitive coloring recording layer from being erased by oils, hair conditioners, plasticizers, etc. is the same as
Included in this proposal.

Note that the support may be paper made mainly of natural fiber pulp, paper-like sheet made mainly of synthetic fibers, or plastic film, but in this invention, paper made mainly of natural fiber pulp gives the best results (least colored fog). ) was selected and used.

(D) Example Examples are shown in FIGS. 1-6.

In Figure 1, a layer 4 mainly composed of micro hollow spherical particles and/or porous pigment is provided between a paper 1 as a support and in contact with the lower side of a thermosensitive color recording layer 2 on the surface. As an example, when the thermal delayed tack layer 3 on the back side is activated by heating with hot air or infrared rays (hot rays), the coloring fog of the thermosensitive color recording layer 2 on the front side is compared to when layer 4 is not provided. This has been significantly reduced, making it suitable for practical use.

FIG. 2 shows an example in which a barrier layer 5 is further provided between the support paper 1 and the tack layer 3 in contact with the example shown in FIG. This not only prevents a decrease in the amount of effective glue, but also further reduces the coloring fog of the heat-sensitive coloring layer 2, making it even more desirable.

FIG. 3 shows an example in which a layer 4 mainly composed of micro hollow spherical particles and/or porous pigment is provided between the tack layer 3 on the back side and the support paper 1, and is similar to FIG. 1. Color fog was reduced.

FIG. 4 shows an example in which a barrier layer 5 is further provided between the tack layer 3 and the porous layer 4 in contact with the example shown in FIG. a decrease was brought about.

5 and 6 are examples in which a porous layer 4 is provided on both sides of the support paper 1, and the effect of preventing color development and fogging becomes even more remarkable. In particular, in an example in which a barrier layer 5 is provided as shown in FIG. The best results were obtained.

(E) Effect of the invention As detailed above, in a thermal delayed tack sheet having a thermosensitive coloring recording layer on the surface, a porous layer is provided between at least one of the layers, and if desired, a barrier layer is provided as a tack layer. By providing the heat-sensitive color recording layer in contact with the color recording layer, it was possible to obtain the article without color fog.

[Brief explanation of drawings]

1 to 6 are schematic cross-sectional views of heat-sensitive tack paper having both a heat-sensitive color recording layer and a thermal delayed tack layer, showing examples of the present invention. In the figure, 1... Paper, 2... Thermosensitive color recording layer, 3...
A thermal delayed tack layer, 4... a layer containing micro hollow spherical particles and/or a porous pigment as a main component, and 5... a barrier layer are shown, respectively.

Claims (1)

[Claims for Utility Model Registration] (1) A paper 1 as a support, on one side thereof a thermosensitive color recording layer 2 which is usually colorless or light colored and develops color when heated, and on the other side a generally non-adhesive recording layer 2. A thermal delayed tack sheet provided with a thermal delayed tack layer 3 that is activated to generate tack when heated and maintains tack even after the temperature is lowered, wherein micro hollow spherical particles and/or particles are provided between at least one of the layers. Or a thermal delayed tack sheet characterized by having a layer 4 mainly composed of porous pigment. (2) The thermal delayed tack sheet according to claim 1, further comprising a barrier layer 5 provided in contact with the thermal delayed tack layer 3.