JPH09158096A - Partly coated release paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain partly coated release paper which has compatibility of characteristics such as air permeability, water absorptivity, oil absorptivity, oil resistance, waterproofness, etc., and is useful as a packaging material for foods, etc., by forming releasant layers only on tops of the raised parts of base paper whose surface has been processed to have continuous unevennesses. SOLUTION: This partly coated release paper has releasant layers 4 only on tops of the raised parts 3 of base paper 1 which is any one of ordinary paper, no-sized paper, highly sized paper, water-repellent paper, oil-resistant paper, white boards, or corrugated boards, whose surface has been processed to have continuous unevennesses 2, 3 of embossed pattern. The continuous unevennesses 2, 3 are preferably formed by a craping or corrugating process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a packaging material for wrapping an adhesive material, a warming bag for a microwave oven, or a release paper as a cooking sheet material for cooking, and in particular, an uneven surface. By coating the release agent only on the convex parts of the base paper with a certain amount, not only the peelability but also the characteristics that make use of the characteristics of the base paper depending on the end use application can be applied, and the partially coated release paper that can greatly expand the application Regarding

[0002]

2. Description of the Related Art Among processed papers which have been given a property according to a specific application by subjecting the paper to secondary processing, there is a release paper as a paper which has particularly good releasability. This release paper is
Originally, it has been used for labels, paper seals, etc., which can be pasted on the surface of paper that has been coated with adhesive paste and can be peeled off immediately before use.

Recently, this type of release paper has a releasability as a commercial packaging material for packaging to protect highly sticky contents, a packing sheet for sticky food, and a cooking sheet for cooking. Applications are expanding into various fields where the good characteristics can be utilized. For example, it has been used as a material for a reheating bag for warming food in a microwave oven, an underlay for sticking sticky food such as cooked rice, and a mount.

Conventionally, release paper is obtained by subjecting the surface of paper to secondary processing with silicone resin. Since paper has innumerable irregularities on its surface, it is necessary to improve the releasability in order to save the amount of the release agent and to prevent the release agent from seeping. In the conventional release paper, as shown in FIG.
The mainstream is one in which a sealing material 41 typified by a synthetic resin film, polyvinyl alcohol, or a nitrified cotton coating is laminated on the surface of the base paper 40, and a silicone-based release agent 42 is coated on it.

On the other hand, a paper having a very smooth surface,
For example, when high density paper such as glassine paper or solvent resistant paper such as oil resistant paper is used as the base paper, a silicone release agent is applied to the surface of the paper without applying a sealing agent. Directly coated, or a coated paper coated with a paint mixture of a silicone resin emulsion and a binder represented by an acrylic resin emulsion, or a release agent such as a copolymer of a silicone resin and a binder resin. There is.

As such a release paper, a release paper obtained by further embossing the release paper as described above is also known in order to give a pattern to the surface and enhance its decorativeness.

Among special-purpose release papers, there is a release paper in which a release agent is partially printed on a highly smooth paper by using a gravure plate or the like. In the case of this release paper, for example,
It is used for packaging foods that require proper adhesion and peelability, such as meat buns.

[0008]

However, in the conventional release paper, basically, in order to add releasability to the paper, after smoothing the paper, a uniform release agent layer is formed over the entire surface thereof. It has the structure of being formed. For this purpose, FIG.
As shown schematically in Fig. 8, the breathability of water vapor is reduced, and it becomes difficult for water and oil to be absorbed, and the breathability, water absorption, water resistance, and oil absorption originally possessed by the base paper. At present, the properties are not compatible with the releasability, and the original properties are lost.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide the peeling property and the inherent breathability, water absorption, oil absorption, oil resistance, and waterproof property of the paper. It is to provide a partially coated release paper which can utilize the original properties of the paper by satisfying both of the properties described in (1) and (2) above and can add properties that are not present in conventional release papers.

Another object of the present invention is to provide a partially coated release paper having excellent properties especially for food packaging applications.

[0011]

In order to achieve the above-mentioned object, the present invention provides that a release agent layer is formed only on the top surface of the convex portion of the base paper having the surface processed with continuous irregularities. It is characterized by. The irregularities may preferably be embossed patterns, or irregularities formed by continuous creping or corrugating of the paper surface.

As the base paper, general paper, non-size paper, high-size paper, water repellent paper, oil resistant paper, white paperboard, cardboard, etc. can be used.

Further, the present invention is characterized by comprising a multi-layered laminate containing a release paper in which continuous unevenness is formed on the surface of the base paper and a release agent layer is formed only on the top surface of the projections. Is.

The multilayer laminate has a structure in which at least one of release paper, paper, plastic film, nonwoven fabric, and resin coat layer is laminated.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a partially coated release paper according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a release paper according to an example of the embodiment of the present invention. Reference numeral 1 is a base paper, 2 is a thin groove formed in a line on the surface of the base paper 1 at a constant pitch,
Reference numeral 3 denotes a ridge between the narrow grooves 2. In this way, the surface of the base paper 1 is continuously formed with a line-shaped concavo-convex pattern including the fine grooves 2 and the convex stripes 3, and the release agent layer 4 is formed only on the top surface of the convex stripes. is there.

As the base paper 1, in order to finally select the characteristics of the paper according to the use of the release paper, ordinary paper, glassine paper, no-side paper, high-side paper, water-repellent paper, oil-resistant paper,
Various papers such as white paperboard can be used.

As the separating agent, a silicone resin,
And wax-based release agents commonly used in the manufacture of release papers can be used.

Next, FIGS. 2 and 3 are explanatory views of a method for manufacturing a release paper. First, as shown in FIG. 2, in the first step, the surface of the base paper 1 is embossed so that the fine grooves 2 and the ridges 3 are formed.
The line-shaped unevenness made of is processed. This embossing can be performed by holding the base paper 2 between the nip roll 10 and the engraving roll 11 in which the convex portion corresponding to the narrow groove 2 is formed, and rotating the paper.

In the case of embossing, the uneven pattern formed on the surface of the base paper is not limited to the uneven line stripe pattern shown in FIG. For example, the unevenness of a lattice pattern as shown in FIG. 8 or the lightning-shaped unevenness pattern as shown in FIG. 9 or the unevenness pattern as shown in FIG. May be formed. Further, although not shown, various irregular patterns can be used as long as they can be embossed, such as specific patterns, scattered irregularities of patterns, and irregularities forming a pictorial pattern.

Next, FIG. 3 is a view showing a method of processing the release agent layer 4 after forming the unevenness. The base paper 1 having the unevenness composed of the fine grooves 2 and the ridges 3 is coated with the release agent. While sandwiching between the nip roll 10 of the machine and the gravure roll 12,
The release agent 4 can be selectively applied only to the top surface of the ridge 3.

Next, FIG. 4 is an enlarged cross-sectional view showing a state in which the adhesive tape 14 is attached to the release paper 6 of the present invention.

In the release paper 6, the pressure-sensitive adhesive layer 15 applied to one surface of the pressure-sensitive adhesive tape 14 and the release agent layer 4 on the top surface of the ridge 3 are in contact with each other. Therefore, the peeling property is added and the adhesive tape 14 can be easily peeled off.

FIG. 5 is an enlarged cross-sectional view schematically showing how the adhesive solid material 15 is attached to the release paper 6. The releasability of the release paper is related to the width W and the depth D of the narrow groove 2. When the width W of the narrow groove 2 is wide because of the relative relationship with the size of the adhesive 15, the area of the uncoated portion of the release agent other than the protrusions 3 increases, and the contact between the adhesive 15 and the release agent layer 4 increases. The area becomes smaller and the peeling effect is reduced. Further, if the width W is wide and the depth D is shallow, the sticky substance is likely to come into contact with the fine groove 2 in the uncoated portion. Therefore, the depth D may be shallow when the width W is narrow, but needs to be deepened as the width W is widened.

The above is a description of the releasability of the release paper of the present invention. Next, its advantageous properties will be described in relation to the properties of the base paper.

FIG. 6 is a diagram for explaining the absorption action of water and oil and the permeation action of water vapor and gas in the release paper 6. In the case of this release paper 6, among the unevenness of the surface, in the narrow groove 2 where the release agent 4 is not applied and the surface of the paper is directly exposed, water vapor and gas permeate through the surface of the paper, and Water and oil fluids can easily penetrate.

Next, specific examples of the present invention will be described.
explain.

Example As an example of the release paper of the present invention, as the base paper 1, a non-size stripe type embossed paper (convex width of 1.1 mm, narrow groove width of 0.4 mm, depth of 20 μm) was used. A release paper coated with a silicone release agent was produced by using a gravure coater, and the performance test was performed with a commercially available cooking sheet having release characteristics and a release paper for labels. Table 1 shows the results.

The performance test method is as follows.

Tape peeling: Cellotape (trademark) is attached to a test paper with a constant load and its peeling property is examined.

-Air permeability ... According to JIS P 8117 Air permeability test method for paper and paperboard.

Moisture Permeability ... According to JIS Z 0208 moisture proof packaging material moisture permeability test method, the peeled surface was measured upward, and moisture absorption conditions were 40 ° C. and 90% RH.

Water Absorption ... The water absorption of JIS P 8140 paper and paperboard was measured according to the test method (Cobb), and the water absorption time was 1 minute to allow water to be absorbed from the peeling surface for measurement.

-Oil Absorption Degree: According to JIS Z 8140, the oil was absorbed from the peeled surface in 1 minute with an oil absorption time of 1 minute using a salad oil instead of water.

[0035]

[Table 1] As is apparent from the above test results, in the conventional commercially available release paper, in addition to the releasability, waterproof properties and oil resistance are in tune with properties that are in harmony with the releasability. While ensuring the releasability equivalent to commercially available release paper, the water-absorbing property, the oil-absorbing property, which is a property contradictory to the releasability,
It is possible to obtain a release paper excellent in air permeability such as air permeability and moisture permeability.

Next, another embodiment of the release paper of the present invention will be described.

The release paper according to the second embodiment is formed by combining paper, film, and non-woven fabric and laminating them to add characteristics according to the end use application.

The release paper shown in FIG. 11 is obtained by coating the top surface of the ridge 3 with the undercoat 20 and then coating the release agent 20.

By using a general paper having water absorbency as the base paper 1 for this release paper, for example, sticky rice can be prevented from sticking and water can be appropriately absorbed. Therefore, this release paper can be used as a water absorbent sheet for diapers and cooked rice containers, and as a mount for steaming Chinese buns in a steaming basket.

FIG. 12 shows a release paper in which a plastic film 21 is laminated and laminated on the back surface of the embossed surface of the base paper 1 using the embossed paper. In the case of this laminated release paper, by laminating a plastic film on the back surface, the surface has releasability, water absorption, etc., and in addition to this, properties such as waterproofness, antifouling property, and sealing property are added. can do. Therefore, this release paper can be used as a warm bag in a microwave oven or an oven. In particular, as a warming bag for cooked rice, the rice is peeled off due to its airtightness and can be warmed deliciously.

Next, the release paper of FIG. 13 is a release paper having a three-layer laminated structure in which a white paperboard 22 is further laminated on the film laminate release paper of FIG. In this laminated release paper, rigidity can be added to the paper by laminating the white paperboard 22, and it can be used as a material for a box for food packaging such as a lunch box.

The release paper of FIG. 14 is a release paper having a two-layer laminated structure in which a bag oil paper 24 or a waterproof paper 25 is bonded to the base paper 1 of embossed paper with an adhesive layer 23.

This release paper is suitable as a material for a warm bag for oil such as fried chicken and croquettes, since it can add oil resistance to the surface in addition to air permeability and water absorption that allow water vapor and moisture to escape to the outside. Is.

FIG. 15 shows a release paper having a two-layer laminated structure in which the surface of the embossed paper is coated with an oil resistant agent 26 or a waterproof agent 27 in place of the paper having a specific property. This release paper is suitable as a process paper when baking bread and cakes, and because the same effect can be obtained by using the coat layer instead of oil-resistant paper and waterproof paper, the treatment at the time of disposal is environmental friendly. There is an advantage that it does not become a problem.

Next, FIG. 16 shows a crepe paper 3 as a base paper.
This is an embodiment using 0. Since the crepe paper 30 has irregularities due to crepe processing, in this embodiment, the release agent 4 is applied to the top surface of the convex portion 31 of the crepe paper 30.

FIG. 17 shows an embodiment in which the release agent 4 is applied to the tops of the corrugated ridges 33 in the single-faced corrugated board 32.

As described above, in the embodiment shown in FIGS. 16 and 17, the unevenness is not formed by the secondary processing,
The release agent 4 can be applied by utilizing the unevenness of the paper itself.

[0048]

As is clear from the above description, according to the present invention, the releasability and the nature of the paper,
It is possible to achieve both properties such as breathability, water absorption, oil absorption, oil resistance, waterproofness, etc., and utilize the original properties of paper, as well as water absorption, oil absorption, breathability that conventional release paper does not have. sex,
Since it is a product that does not exist in conventional release paper that exhibits properties such as moisture permeability, its application can be greatly expanded. In addition, the release paper of the present invention can be added with excellent properties especially as a material for food packaging, so that excellent paper can be obtained as a material for food packaging and a heating bag for a microwave oven.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a release paper according to the present invention.

FIG. 2 is an explanatory view showing a step of making unevenness on the embossed paper in the step of manufacturing the release paper of FIG.

FIG. 3 is an explanatory view showing a step of applying a release agent to the protrusions in the step of manufacturing the release paper of FIG.

FIG. 4 is a cross-sectional view of a state in which an adhesive tape is attached to the release paper of FIG.

5 is a cross-sectional view of the release paper of FIG. 1 with sticky solids attached.

FIG. 6 shows the water absorbency and oil absorbency of the release paper according to the present invention.
Explanatory drawing of the action of breathability.

FIG. 7 is a schematic diagram showing a stripe-shaped unevenness as one example of embossed unevenness patterns on the surface of the base paper.

FIG. 8 is a schematic diagram showing a grid-shaped unevenness as one example of embossed unevenness patterns on the surface of the base paper.

FIG. 9 is a schematic diagram showing a lightning bolt type unevenness as one example of embossed unevenness patterns on the surface of the base paper.

FIG. 10 is a schematic view showing a round groove-shaped unevenness as one example of embossed unevenness patterns on the surface of the base paper.

FIG. 11 is a cross-sectional view of another embodiment of the release paper of the present invention in which the release agent 20 is coated on the top surface of the ridges via an undercoat.

FIG. 12 is a cross-sectional view of a release paper in which a plastic film is laminated and laminated on the back surface of an embossed surface of a base paper using embossed paper.

13 is a cross-sectional view of a release paper having a three-layer laminated structure in which white paperboard is further attached to the film laminate release paper of FIG.

FIG. 14 is a cross-sectional view of a release paper having a two-layer laminated structure in which a bag oil paper or waterproof paper is bonded to an embossed base paper via an adhesive layer.

FIG. 15 is a cross-sectional view of a release paper having a two-layer laminated structure in which the back surface of the embossed paper is coated with an oil resistant agent or a waterproof agent instead of the paper having a specific property.

FIG. 16 is an explanatory diagram of another embodiment using crepe paper as a base paper.

FIG. 17 is an explanatory diagram of another embodiment in which a release agent is applied to the tops of the piles of single-faced cardboard.

FIG. 18 is an explanatory view showing the structure of a conventional release paper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base paper 2 Narrow groove (concave part) 3 Convex strip (convex part) 4 Release agent 10 Nip roll 11 Engraving roll 12 Gravure roll 14 Adhesive tape 15 Adhesive solid matter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 7/02 JKW C09J 7/02 JKW 7/04 7/04

Claims (8)

[Claims] 1. A partially coated release paper, characterized in that a release agent layer is formed only on the top surface of the projections of a base paper having a surface with continuous irregularities. 2. The partially coated release paper according to claim 1, wherein the irregularities are embossed patterns. 3. The partial coat peeling according to claim 1, wherein the base paper is any one of plain paper, non-size paper, high-size paper, water-repellent paper, oil-proof paper, white paperboard, and corrugated board. paper. 4. The partially coated release paper according to claim 3, wherein the continuous unevenness on the paper surface is unevenness formed by crepe processing or corrugation processing. 5. A partially coated release paper comprising a multi-layered laminate including a release paper in which continuous unevenness is formed on the surface of a base paper and a release agent layer is formed only on the top surfaces of the projections. 6. The partial coat peeling according to claim 5, wherein the base paper is any one of ordinary paper, non-size paper, high-size paper, water-repellent paper, oil-proof paper, white paperboard and cardboard. paper. 7. The partially coated release paper according to claim 6, wherein the continuous irregularities on the paper surface are irregularities formed by embossing, creping or corrugating. 8. The partially coated release paper according to claim 6, wherein the multi-layer laminate comprises release paper and at least one layer of paper, a plastic film, a non-woven fabric and a resin coat layer.