JPH07122239B2 - Release paper - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release paper which is used by being stuck to an adhesive surface in an adhesive processed product such as wallpaper, stickers and stickers.

[0002]

2. Description of the Related Art In recent years, along with the increasing demand for seals, stickers, callus products, etc., the demand for release paper to be used by sticking to the adhesive surface of these adhesive processed products has also increased, and the quality requirements thereof have also become strict. There is. Conventionally, as this type of release paper, a paper serving as a support, for example, glassine paper having a release layer formed by coating a release agent such as a release silicone resin on one or both surfaces is generally used. However, in a release paper having such a constitution, the release agent penetrates into the paper layer which is the support, and a large amount of release agent is required to form a release layer having a release property sufficient for practical use. It left the problem that a release agent was needed. In addition, the effect of the surface irregularities of the paper support itself appears on the surface of the release layer, resulting in uneven adhesion with the adhesive after the adhesive processing, and when the release paper is peeled off, the surface of the adhesive has fine irregularities. And had a problem in appearance. Further, in a release paper using such a simple paper as a support, the paper absorbs and dehumidifies due to changes in the humidity of the surrounding environment, and as a result, the release paper curls, causing problems in the manufacturing process. , The quality of the bonded product was deteriorated.

On the other hand, in order to solve the above problems,
A release paper in which a resin such as polyethylene is laminated on one side or both sides of a paper support and a release agent is applied on the film is also used. The release paper having such a structure has an advantage that the polyethylene layer prevents the release agent from penetrating into the support and a sufficient release property can be obtained with a small amount of the release agent. Compared with the coating layer, the thickness of the layer is thicker, it is difficult to make it thinner, it is difficult to form a uniform layer thickness, and there is a large variation in thickness.Therefore, a thin, low-cost release paper with a uniform thickness can be obtained. It has a problem that it cannot be done. Therefore, instead of laminating a resin such as polyethylene on the support, it has been proposed to coat the resin with the same performance as a polyethylene film laminate. However, even with release papers having these resin coating layers, as with the paper-based release papers described above, the property of preventing the infiltration of moisture is inferior to that of the polyethylene laminate layer, so curling due to changes in ambient humidity is avoided. It was not there. As described above, a good release paper that solves all of these problems has not yet been obtained.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a release paper which can be uniformly applied with a small amount of release agent applied. Further, the present invention provides a release paper that suppresses the occurrence of curling due to changes in the humidity of the surrounding environment.

[0005]

According to the present invention, a pigment layer, a resin layer and a release layer are sequentially laminated on at least one surface of a support, and the pigment layer contains mica as a main component, and the resin layer Is a release paper characterized by containing a vinylidene chloride resin as a main component. That is, one example of the present invention will be described with reference to the drawings. As shown in FIG. 1, a support 1 has a pigment layer 2 containing mica as a main component on one surface thereof, and a vinylidene chloride resin as a main component on the pigment layer 2. The resin layer 3 and the peeling layer 4 are sequentially provided. In addition,
Of course, the above-mentioned layered structure on both sides of the support can be used.
The pigment layer 2 on the support 1 in the present invention is provided in order to impart good humidity barrier property (moisture resistance barrier) to the release paper. The pigment layer 2 is mainly composed of mica as a pigment and resin as a binder, and in order to obtain a good humidity barrier property, the ratio of mica / resin is 1 by weight.
/ 1 to 3/1 is preferable, and especially 1/1 to 2 /
The range of 1 is preferable because the surface smoothness can be easily enhanced by a method such as calendering. As described above, after the pigment layer 2 is formed, the smoothness of the surface of the pigment layer can be increased by the calendering treatment before the resin layer is provided. In the pigment layer, when the mixing ratio of mica exceeds 3 parts by weight with respect to 1 part by weight of the resin, good humidity barrier property cannot be obtained. Further, when the amount of mica is less than 1 part by weight with respect to 1 part by weight of the resin, the humidity barrier property becomes insufficient and there is a possibility that curling is likely to occur.

Examples of the mica used in the present invention include sericite, muscovite, phlogopite, soda mica, sericite, vanadine mica, biotite, phlogopite, lithia mica, tinwald micas, synthetic mica (for example, Examples include mica groups such as MK series and ME series manufactured by Coop Chemical Co.,
These can be used alone or in combination. These mica groups generally have a scale-like crystal structure, and when they are layered with an appropriate resin, the scale-like crystals partially overlap each other, and good barrier properties can be exhibited. It is possible to suppress the permeation of the coating material into the support body at the time of doing. Therefore, by forming a layer of mica, it is possible to obtain a uniform thin film of the release agent, and it is possible to provide good release characteristics with a smaller amount of the release agent. Of these, muscovite, lithia mica, and sericite are preferable because of their natural color and low cost.

In addition to the above-mentioned mica, various commonly used pigments can be used in combination in the pigment layer of the present invention. Specific examples of these various pigments include silica, clay, mica, talc, kaolin, diatomaceous earth,
Calcium carbonate, calcium sulfate barium sulfate, aluminum silicate, synthetic zeolite, alumina, zinc oxide,
In addition to conventionally used fillers such as lithopone and satin white, organic or inorganic color pigments and the like can be mentioned, but not limited to these.

As the resin used as the binder when forming the pigment layer of the present invention, various resins generally used for coating can be used. Specific examples of these resins include, for example, acrylic resins, polyester resins, polyurethane resins, styrene-butadiene copolymer resins, acrylonitrile-butadiene copolymer resins, polyvinyl alcohol resins, other vinyl resins, amide resins. Resins, oxidized starch, casein, polyethylene oxide, polyvinylpyrrolidone, silicone resins, rosin-modified maleic acid resins, rosin-modified phenol resins, alkyd resins, coumarone-indene resins, butyral resins, etc., alone or in combination of two or more thereof. Can be used. Among these, water-soluble or water-based emulsion resins are preferable because of the dispersibility of mica and the ease of handling during production.

The resin layer 3 of the present invention contains a vinylidene chloride resin as a main component and has a low hygroscopic property which is a characteristic of the vinylidene chloride resin. In this way, the release paper is prevented from curling. The content of the vinylidene chloride resin used as the main component is preferably about 70% by weight or more. Further, this resin layer 3 is preferably formed of a resin alone without using a pigment or a filler, and even if a pigment is used for the reason of blocking prevention, it does not function as a humidity barrier as described above. It is necessary to use only a small amount so as not to damage it. The vinylidene chloride-based resin used in the resin layer of the present invention is a vinylidene chloride homopolymer, a copolymer with a copolymerizable vinyl-polymerizable monomer, or a modified one thereof, which has been conventionally used. Known types of materials such as emulsion type and solution type can be used.

In the present invention, as the support, not only general high-quality paper, but also various kinds of papers and non-woven fabrics made of wood pulp, synthetic pulp and the like by a wet papermaking method, and other sheet-like materials by a dry papermaking method are appropriately used. can do. The release layer is made of a conventionally known release material, that is, a release agent. That is, as the release layer, for example, a release layer made of various addition-type or condensation-type silicone compounds or silicone rubber, a reactive silicone oil and a functional group-containing resin, a release layer in which a cross-linking agent is combined therewith, fluorine, A release layer made of a polymer, a release layer made of a non-silicone release agent (for example, Pyroyl series manufactured by Yansha Yushi Kogyo Co., Ltd.) can be applied, but the release agent is not limited to this and various release agents can be used. Can be used to form the release layer.

In the release paper of the present invention, when the pigment layer, the resin layer and the release layer are provided on the support, a coating material prepared by uniformly mixing and dispersing the materials for forming each layer is prepared by a roll coating method, Blade coating method,
Spray coating method, air knife coating method,
A coating method such as a rod bar coating method may be applied and dried according to the lamination order of the present invention.
The coating amount of the pigment layer is about 5 to 15 g / m ² , preferably 8 to 10 g / m ² , and the coating amount of the resin of the resin layer is about ² to 10 g / m ² , preferably 3 to 5 g / m 2. ² and the coating amount of the release agent of the release layer is 0.1 to ² g / m ²
The degree is preferably 0.5 to 1 g / m ² .

[0012]

EXAMPLES Next, the present invention will be described in detail by way of examples. In addition, all the parts showing the composition represent parts by weight. Example 1 A pigment layer coating composition (dry coating amount: 8 g / m ² ) was provided by coating and drying a pigment layer coating material having the following composition on both sides of a support made of woodfree paper having a basis weight of 90 g / m ² . Sericite (Microclean, manufactured by Dowa Mining Co., Ltd.) 10 parts Styrene-butadiene latex 23 parts (Lack Star 6071A, Dainippon Ink and Chemicals, Inc., solid content 45%) Water 30 parts Next, provided as above. The resin layer coating material having the following composition is applied and dried on both surfaces of the pigment layer to form a resin layer (application amount: 5
g / m ² ) was provided. -Vinylidene chloride-based latex (Saran latex L-530, manufactured by Asahi Kasei Kogyo KK, solid content 49%) Next, the support on which the pigment layer and the resin layer are placed is subjected to a calendering treatment to improve smoothness on both sides. , A release layer coating material having the following composition is applied only on one side, and
The release paper of the present invention was prepared by drying and curing for 60 seconds with hot air at 0 ° C. to provide a release layer having a thickness of 0.1 μm.・ Silicon 10 parts (SD7226, manufactured by Toray Dow Corning Silicone, solid content 30%) ・ Curing catalyst 0.03 part (Platinum curing catalyst SRX212, manufactured by Toray Dow Corning Silicone) ・ Toluene 20 parts ・ Ethyl acetate 10 parts

Example 2 Except that the following composition was used as the paint for the pigment layer,
A release paper of the present invention was produced in exactly the same manner as in Example 1. White muscovite (A-11, Yamaguchi Mica Kogyo Co., Ltd.) 10 parts Styrene-butadiene latex 15 parts (Lack Star 6071A, Dainippon Ink and Chemicals, Inc., solid content 45%) Water 30 parts

Example 3 A release paper of the present invention was produced in exactly the same manner as in Example 1 except that the paints for the pigment layer and resin layer having the following compositions were used. Pigment layer paint-Sequin mica (Microclean, Dowa Mining Co., Ltd.) 10 parts-Acrylic emulsion 10 parts (Movinyl 767, Hoechst Synthetic Co., solid content 45%)-Water 30 parts Resin layer paint-Polyvinylidene chloride Emulsion (Kureharon latex, LA412 Kureha Chemical Industry Co., solid content 46%)

Example 4 A resin layer coating material having the following composition was used, except that
A release paper of the present invention was produced in exactly the same manner as in Example 3. -Polyvinylidene chloride resin (Saran resin, F-216 manufactured by Asahi Kasei Corporation) 10 parts-Tetrahydrofuran 90 parts

Comparative Example 1 A release paper for comparison was prepared in the same manner as in Example 1 except that the resin layer was not provided. Comparative Example 2 A release paper for comparison was prepared in exactly the same manner as in Example 1, except that the pigment layer was not provided in Example 1. Comparative Example 3 Glassine paper having a basis weight of 50 g / m ² was used as a support,
The coating amount for the release layer used in Example 1 was applied and dried without providing the pigment layer and the resin layer, and the coating amount was 0.1 g / m 2.
^Two release layers were provided to produce a release paper for comparison.

With respect to the release papers obtained in the above Examples 1 to 4 and Comparative Examples 1 to 3, a curl humidity dependency test was conducted. Curling humidity dependence test method After each sample was left in an environment of 20 ° C. and 65% RH for 24 hours, a polyethylene terephthalate film having a thickness of 25 μm, which was adhesive processed in the same environment, was attached.
After each bonded sample was further left in an environment of 20 ° C and 65% RH for 24 hours, it was cut into A4 size, high humidity (30 ° C.80% RH) and low humidity (30 ° C, 20% R).
The curl after leaving for 4 hours in each environment of H) was confirmed. When the curl was large and caused a problem in the process or quality, the mark was X, and when the curl was small and there was no problem in practical use, the mark was ○.
The test results are as shown in Table 1. The number in parentheses in Table 1 indicates the curl amount of the curled sample, and the unit is mm. The curl amount is measured by measuring the distance (height) from the floor to the curved four corners of the sample, and the maximum value is shown. As is clear from the results shown in Table 1, it was confirmed that the release paper of the present invention has the property of not causing a large curl even when the humidity changes. The sample of Comparative Example 3 was completely rolled into a cylinder under high humidity, and the distances at the four corners could not be measured.

[0018]

[Table 1]

[0019]

The release paper of the present invention is provided with a pigment layer containing mica and a resin layer containing vinylidene chloride as a lower layer of the release layer, whereby good barrier properties can be obtained and penetration of the release agent can be achieved. Sufficient release performance can be obtained with a small amount of release agent, and curling does not occur due to changes in humidity.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of Codes] 1 Support 2 Pigment layer containing mica as a main component 3 Resin layer containing vinylidene chloride resin as a main component 4 Release layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-257395 (JP, A) Actually open 5-10438 (JP, U) Actually open 62-75045 (JP, U)

Claims (1)

[Claims] 1. A support, wherein a pigment layer containing mica as a main component, a resin layer containing vinylidene chloride resin as a main component, and a release layer are sequentially laminated on at least one surface of a support. Release paper.