JPH09217299A - Release paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain release paper for tacky sheets by using glassine paper having light transmissivity, obtained by carrying out papermaking of mixture of pulps having different beating degrees, without hindering detection of position in labeller equipped with a transmission type position detector. SOLUTION: Needle-leaf tree pulp having 100-250ml CSF freeness in an amount of 90-60 pts.wt. is mixed with 10-40 pts.wt. broadleaf tree pulp having >=400ml CSF or unbeaten broadleaf tree pulp and the mixed pulp is formed into paper to provide raw paper for glassine paper. An aqueous resin solution of polyvinyl alcohol is applied to the raw paper by a coating part such as a size press device and a gate roll coating machine and subjected to compression treatment with a super calender, etc., to provide the objective glassine paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release paper used for an adhesive sheet, and more particularly to a release paper using glassine paper which has no problem in position detection by a labeler having a transmission type position detector. Is.

[0002]

2. Description of the Related Art Conventionally, pressure sensitive adhesive sheets are used for labels, stickers,
It is used for a wide range of purposes such as stickers, patches, and over-laminations, including commercial, office, and household use. This pressure-sensitive adhesive sheet is generally constructed by laminating a surface base material, a pressure-sensitive adhesive, and release paper. Solvent type adhesives, emulsion type adhesives, hot melt type adhesives and the like are used as the adhesive.

The surface substrate includes high-quality paper, kraft paper, art paper, coated paper, cast coated paper, general paper such as thermal recording paper, aluminum foil laminated paper, aluminum vapor-deposited paper, resin-impregnated paper,
Special papers such as synthetic paper and films such as PET, polypropylene and polyvinyl chloride are used. Among them, films are used for pressure-sensitive adhesive sheets for over-lamination, outdoor, etc. because they have higher durability than papers for other surface base materials, and because they have extremely high gloss, they have high-class feeling. Used for certain adhesive sheets.

On the other hand, as the release paper, polyethylene laminate type, glassine type, clay coat type,
It can be classified into water-based resin coat type and film base type, etc.
The glassine type is widely used.

In particular, a polyethylene laminate type release paper is often used as an adhesive sheet using a film as a surface base material. Since the surface base material is a film, there is no dimensional change due to humidity change, but since the release paper is paper, the dimensional change due to humidity change is remarkable. As a result, the dimensional changes of the surface base material and the release paper are different, which causes a problem of curling of the pressure-sensitive adhesive sheet due to changes in humidity. In order to suppress this curl as much as possible, a polyethylene laminate type release paper is used in order to suppress dimensional change due to humidity change of the release paper.

The polyethylene laminate type is usually coated on the surface of the base paper in order to prevent the release agent such as silicone from soaking into the inside of the base paper such as high-quality paper and kraft paper, or for the purpose of exerting the release performance effectively. The polyethylene is laminated, and a release agent layer is provided thereon. Furthermore, when films are used as the surface substrate of the pressure-sensitive adhesive sheet, the back surface of the release paper may be subjected to polyethylene lamination treatment to prevent curling. As the polyethylene to be laminated, high-pressure low-density polyethylene is typically used. The polyethylene laminate type has an advantage of effectively exhibiting the peeling performance because the silicone (release agent) is completely retained on the polyethylene layer formed on the high quality paper or kraft paper rich in voids.

However, since high-quality paper or kraft paper is used as the base paper for the release paper, it has a poor light transmissivity and causes a problem in label position detection by a labeler having a transmissive position detector. In addition, when the adhesive sheet is used in the form of winding, the polyethylene laminate type uses thick paper such as high-quality paper and kraft paper, so the winding diameter becomes large and the efficiency during processing deteriorates. Has the drawback of.

On the other hand, the glassine type usually has a beating degree of 2
This is a glassine paper obtained by papermaking using chemical pulp that has been subjected to a high-level beating treatment in the range of 30 to 350 ml CSF as a raw material, and further densified with finishing equipment such as a super calender, and provided with a release agent such as silicone. Since the glassine type has a light transmitting property, it can be applied to a labeler having a transmission type position detector, and the release paper has a relatively thin paper thickness. When a film is used as the surface substrate to form a pressure-sensitive adhesive sheet, polyethylene coating may be applied to the release agent-coated surface or both surfaces before applying a release agent such as silicone to prevent curling.

Recently, for the purpose of accurately detecting the position with a labeler having a transmission type position detector by further increasing the transparency, or suppressing the penetration of the release agent into the inside of the base paper as much as possible, For the purpose of ensuring effective release performance by holding, a coater such as a size press machine installed in the middle of the drying section of the paper machine or an off-machine coater, etc., an aqueous solution of polyvinyl alcohol resin, etc. Is applied. Therefore, the release paper using the glassine paper has an advantage that it has excellent light transmittance and does not cause a problem in label position detection by a labeler having a transmission type position detector.

[0010]

However, in the case of a pressure-sensitive adhesive sheet in which a release paper using glassine paper and a film as a surface base material are combined, it does not occur when high-quality paper or kraft paper is used as a base paper for release paper. A new issue arose. That is, a pressure-sensitive adhesive sheet comprising a release paper using glassine paper and a film surface substrate has high gloss, but the surface of the pressure-sensitive adhesive sheet has an uneven appearance and gloss unevenness, which gives a high-grade pressure-sensitive adhesive sheet. Is difficult to obtain. In addition, even when a release paper is used as a base paper which is polyethylene laminated on glassine paper, the appearance of unevenness and uneven gloss on the surface of the pressure-sensitive adhesive sheet makes it difficult to obtain a high-quality pressure-sensitive adhesive sheet.

In view of the present situation, the present inventor has used the glassine paper as the base paper for the release paper and the cause of the unevenness of the surface of the pressure-sensitive adhesive sheet and the unevenness of gloss generated when the film is used as the surface substrate. The intensive research was conducted from all angles such as the surface base material, the adhesive layer, and the release paper.

As a result, it was found that the unevenness in the wavelength of 2 to 10 mm (texture unevenness) of the glassine paper used as the base paper for the release paper and the unevenness and gloss unevenness on the surface of the pressure-sensitive adhesive sheet are the same. That is, unevenness of the surface of the release paper itself occurs due to uneven texture of the glassine paper used as the base paper, and the film of the surface base material promotes the unevenness, and the unevenness and gloss of the adhesive sheet surface It turned out to be causing unevenness. Also,
Similar to glassine paper, when using release paper that uses high-quality paper or craft paper that has wavelength unevenness (formation unevenness) of 2 to 10 mm as the base paper, the release paper is polyethylene laminate type, clay coat type, water-based resin coat It was found that, regardless of the type, unevenness and uneven gloss on the surface of the pressure-sensitive adhesive sheet hardly occur.

As a result of further detailed research based on these results, from the physical viewpoint, glassine paper is used as a raw material pulp that is highly beaten as compared with high-quality paper and kraft paper, and Since it is subjected to a densification treatment with a super calendar or the like, a dimensional change due to moisture absorption or the like due to a humidity change is large, and this dimensional change and unevenness in the formation cause minute uneven thickness on the glassine paper. It has been found that the uneven thickness causes unevenness on the surface of the release paper, and the surface substrate film having high gloss promotes the unevenness and causes unevenness on the pressure-sensitive adhesive sheet surface and uneven gloss. In addition,
Release paper that uses high-quality paper or kraft paper as the base paper does not cause unevenness and uneven gloss of the adhesive sheet, probably because the beating material pulp is shallower than glassine paper and the dimensional change due to moisture absorption due to humidity change Is small, it is considered that the thickness unevenness is small.

From the optical viewpoint, as described above, 2 to 10
Unevenness due to wavelength unevenness of mm, in other words, 2 to 10
It was found that the unevenness at mm intervals and the uneven gloss visually hindered the high-grade feeling of the pressure-sensitive adhesive sheet. 2-10mm like this
The unevenness of the spacing is caused by the unevenness of the texture, and the unevenness of the texture is present in the glassine paper, the high-quality paper, and the craft paper. This unevenness and gloss unevenness are remarkable in the adhesive sheet using glassine paper, because the glassine paper is densified with highly calcined pulp with a super calender, etc. This is because it is very smooth, and extremely speaking, there is only unevenness in the formation at intervals of 2 to 10 mm, so that it is very noticeable visually. On the other hand, high-quality paper and kraft paper are 2-1 like glassine paper.
Although there is a wavelength unevenness of 0 mm, compared to glassine paper, the pulp is not beaten and it is not densified with a super calender, etc., so the surface of high-quality paper and kraft paper is much smoother than glassine paper. Is low. In other words, fine paper and kraft paper have a much rougher surface than glassine paper. That is, 2 for fine paper and kraft paper
In addition to unevenness unevenness at intervals of -10 mm, there are very many uneven unevennesses at intervals of 1 mm or less. It can be inferred that the unevenness with an interval of 1 mm or less causes light scattering on the surface of the pressure-sensitive adhesive sheet, and as a result, the unevenness with an interval of 2 to 10 mm and the unevenness in gloss are visually inconspicuous.

In order to obtain a high-grade pressure-sensitive adhesive sheet having no unevenness or uneven gloss on the surface, it is desirable to use a release paper using high-quality paper or kraft paper as the base paper, but the transmission type position detection When a labeler with a machine is used, the light transmission is poor and the position detection is difficult, and it cannot be used.
When using a labeler with a transmissive position detector,
Although it is necessary to manufacture adhesive sheets using glassine-type release paper, in actual glassine paper, even if any paper machine is used, the base paper always has texture unevenness. If a release paper is used, the surface of the pressure-sensitive adhesive sheet will have unevenness and uneven gloss, and a high-quality pressure-sensitive adhesive sheet cannot be obtained. The present invention provides a release paper, which has excellent suitability for a labeler having a transmission type position detector, and is a high-grade pressure-sensitive adhesive sheet having no unevenness on the surface or uneven gloss.

[0016]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, as a glassine type release paper base paper, highly beaten wood pulp,
A glassine paper, which is a base paper made by adding wood pulp with a low beating degree including unbeatenness, can be used as a release paper to obtain an excellent adhesive sheet with a sense of unevenness on the surface and a high-grade feeling without uneven gloss. Was found.

That is, according to the present invention, in the release paper having the release agent layer on the glassine paper, the pulp which is the raw material of the glassine paper has 90-60 parts of wood pulp having a freeness of 100-250 ml CSF and 400 ml CSF of the freeness.
The release paper is characterized by comprising 10 to 40 parts of the above or unbeaten wood pulp.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, the beating degree is 100.
90 to 60 parts of wood pulp subjected to advanced beating treatment in the range of up to 250 ml CSF, a beating degree of 400 ml C
10 to 40 or more SF or unbeaten wood pulp, preferably 400 to 500 ml CSF wood pulp is used.
The raw paper of glassine paper is made into a paper by using the material added with parts. This base paper is coated with an aqueous resin solution such as polyvinyl alcohol in a coating section such as a size press machine or a gate roll coating machine, and then compressed in a compression processing section such as a super calender to obtain glassine paper. Next, a release agent layer is provided on the glassine paper to obtain a release paper. Alternatively, polyethylene is laminated on the glassine paper and a release agent layer is provided thereon to obtain a release paper. In this way, the labeler with the transmission type position detector does not have a problem of light transmission for label position detection and peeling without unevenness or uneven gloss on the surface of the adhesive sheet. You can get the paper.

As described above, the raw material pulp used in the present invention contains wood pulp 9 having a beating degree of 100 to 250 ml CSF.
It is necessary to use a mixture of 0 to 60 parts and 10 to 50 parts of a beating degree of 400 ml CSF or more or unbeaten wood pulp. By using a highly beaten pulp with a beating degree of 100 to 250 ml CSF, the light transmissive property peculiar to glassine paper can be imparted by the compression treatment performed later.

Incidentally, the beating degree of pulp is 100 mlCS.
If it is less than F, it has sufficient light transmissivity for position detection by a labeler having a transmission type position detector, but drainage becomes poor, the papermaking speed cannot be increased, and economic efficiency deteriorates. Further, the strength of the glassine paper itself, particularly the tear strength, is remarkably reduced, and it cannot be used as a base paper for release paper. On the other hand, with only pulp having a beating degree of more than 250 ml CSF, sufficient light transmissivity for position detection by a labeler having a transmission type position detector cannot be obtained.

However, such a highly beaten pulp alone does not change from ordinary glassine paper, and causes unevenness of the surface of the pressure-sensitive adhesive sheet and uneven gloss due to uneven dimensional stability and uneven formation. Therefore, in the present invention, highly beaten pulp (beating degree 100 to 250 ml CSF) 9
10-60 parts of pulp with a very low beating degree of 400 ml CSF or more and unbeaten pulp with respect to 0 to 60 parts
By mixing 40 parts, this shallow beating degree and unbeaten pulp serve as the skeleton of the paper to improve the dimensional stability of the base paper, and the formation unevenness and poor dimensional stability when compressed into glassine paper are performed. The feeling of unevenness on the surface due to is reduced. On the other hand, this shallow beating pulp gives unevenness of 1 mm or less on the surface of glassine paper, and as a result, when a pressure sensitive adhesive sheet is manufactured using release paper using this glassine paper as a base paper As a result of scattering, an excellent pressure-sensitive adhesive sheet having no unevenness or uneven gloss on the surface can be obtained as in the case of release paper using high-quality paper or kraft paper as the base paper.
That is, highly beaten pulp imparts light transparency,
The unbeaten or unbeaten pulp physically provides the same dimensional stability as high-quality paper and kraft paper, and optically gives light scattering similar to that of high-quality paper and kraft paper. It is a paper that has the properties of both sides of paper and kraft paper.

Incidentally, the beating degree of pulp is 400 mlCS.
If the mixing amount of F or more is less than 10 parts, or if pulp with a low beating degree of less than 400 ml CSF is used, it is sufficient for position detection with a labeler having a transmission type position detector. However, it is not possible to obtain sufficient dimensional stability and light scattering to improve the unevenness and uneven gloss when the pressure-sensitive adhesive sheet is used. On the other hand, if pulp with a low beating degree or unbeaten pulp is mixed in an amount of more than 40 parts, sufficient light transmissivity cannot be obtained for position detection by a labeler having a transmission type position detector.

As the raw material wood pulp, hardwood bleached kraft pulp, softwood bleached kraft pulp, or other chemical pulp can be used alone or in combination. Softwood kraft pulp is used as a wood pulp with a beating degree of 100 to 250 ml CSF, and hardwood kraft pulp is used as a beating degree of 400 ml CSF or more or an unbeaten wood pulp has high transparency and sufficient dimensional stability to improve unevenness and gloss unevenness. It is particularly preferable because it becomes a base paper having properties. For beating pulp, a conical refiner,
Known devices such as a disc refiner and a beater can be used.

The base paper thus obtained, like the ordinary glassine paper, imparts transparency and suppresses the permeation of the release agent into the inside of the base paper as much as possible, and retains it on the surface of the base paper. For the purpose of achieving effective peeling performance, a polyvinyl alcohol-based resin aqueous solution or the like is applied by a size press device, a gate roll coater, or an off-machine coater installed in the middle of the drying section of the paper machine, A glassine paper is made by compression processing with a finishing facility such as a calendar.

The glassine paper obtained is a release paper obtained by directly or after laminating polyethylene, applying a release agent such as silicone and drying it to form a release agent layer. This release paper has excellent light transmittance, and even when a film or the like is used as the surface base material, a high-grade pressure-sensitive adhesive sheet having no unevenness or uneven gloss can be obtained. A known base material can be used as the surface base material of the pressure-sensitive adhesive sheet. In particular, in addition to films that have the problem of unevenness and uneven gloss, cast coated paper, metal foil, metal vapor-deposited paper, etc. that require glossiness, or a uniform recording layer for image recording, etc. It is also useful for required thermal recording materials, ink jet recording sheets, thermal transfer image receiving sheets and the like. As described above, the release paper of the present invention can be easily manufactured using existing equipment such as a paper machine simply by mixing a predetermined amount of two types of pulps having different beating degrees to make paper. It is possible and is extremely excellent in practicality.

[0026]

The present invention will be described in more detail with reference to the following examples, but of course the present invention is not limited thereto. In each example, "part" and "%"
Unless otherwise specified, “part by weight of solid content” and “% by weight of solid content” are respectively indicated.

Example 1 [Production of glassine paper] First, a stock having the following composition was prepared. Degree of beating: 120 ml CSF (softwood kraft pulp) 65 parts Degree of beating: 420 ml CSF (hardwood kraft pulp) 35 parts 30% Reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 parts 30% Aluminum sulphate 2 parts This paper material is put in a long wire multi-cylinder type paper machine and the basis weight of rice is 73 g / m 2.
The base paper of No. ^{2 was made into} a paper, dried, and then applied with a 5% concentration aqueous solution of polyvinyl alcohol resin (trade name: GH20, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) by a size press device and dried again. The coating amount at this time was 1.2 g / m ² . Then, the above base paper was used as a finished glassine paper in a super calendar facility.

[Production of polyethylene laminated glassine paper] After the corona discharge was applied to the side of the obtained glassine paper on which the release agent layer was provided, low density polyethylene was added by the melt extrusion coating method so that the film thickness became 25 μm. The resin was laminated at a temperature of 330 ° C. to form a surface coating layer.

[Production of Release Paper] A silicone solution having the following composition was prepared. -Addition reaction type silicone (trade name: SD7220, manufactured by Toray) 4.5 parts-Platinum catalyst (trade name: SRX212, manufactured by Toray) 0.5 parts-Toluene 95 parts The obtained polyethylene laminated glassine paper is a base paper As the above, the above solution was applied onto the surface coating layer with a Meyer bar so that the weight after drying was 2.0 g / m ² , to obtain a release paper.

[Production of Adhesive Sheet] An adhesive having the following composition was prepared. -Acrylic solvent-based adhesive (product name: Nisetsu KP-1954, manufactured by Nippon Carbide Co., Ltd.) 100 parts-Curing agent (product name: Nisetsu D-201) 1.5 parts Adhesion described above on the silicone coated surface of the release paper The agent was coated with a comma coater so that the coating amount was 25 g / m ² .
Next, on this adhesive, a commercially available aluminum vapor-deposited PET film having a thickness of 25 μm (trade name: MSN # 25, manufactured by Toray Industries, Inc.)
Were stacked and pasted together with a press roll to obtain an adhesive sheet.

Example 2 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock material was adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 120 ml CSF (softwood kraft pulp) 85 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 15 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Example 3 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock material was adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 240 ml CSF (softwood kraft pulp) 65 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 35 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Example 4 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock materials were adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 240 ml CSF (softwood kraft pulp) 85 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 15 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Example 5 A release paper and a pressure-sensitive adhesive sheet were obtained in the same manner as in Example 1 except that the glassine paper of Example 1 was provided with a release agent layer without being subjected to polyethylene lamination treatment.

Comparative Example 1 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock materials were adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 80 ml CSF (softwood kraft pulp) 65 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 35 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Comparative Example 2 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock material was adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 280 ml CSF (softwood kraft pulp) 85 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 15 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Comparative Example 3 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock material was adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 240 ml CSF (softwood kraft pulp) 65 parts-Beating degree: 380 ml CSF (hardwood kraft pulp) 35 parts-30% reinforced rosin sizing agent (trade name: SPE, Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Comparative Example 4 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock materials were adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 240 ml CSF (softwood kraft pulp) 95 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 5 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Comparative Example 5 A release paper and an adhesive sheet were obtained in the same manner as in Example 1 except that the stock materials were adjusted as follows in the production of the glassine paper of Example 1. Composition of stock material-Beating degree: 120 ml CSF (softwood kraft pulp) 50 parts-Beating degree: 420 ml CSF (hardwood kraft pulp) 50 parts-30% reinforced rosin sizing agent (trade name: SPE, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3 Part ・ 30% aluminum sulfate 2 parts

Comparative Example 6 Example 1 was repeated except that no glassine paper was produced and a high quality paper having a basis weight of 64 g / m ² was used as a base paper instead of glassine paper.
A release paper and an adhesive sheet were obtained in the same manner as in.

[Evaluation] The release paper and pressure-sensitive adhesive sheet thus obtained were evaluated as follows, and the results are shown in Table 1. "Paper Quality of Release Paper" The paper quality of the obtained release paper was evaluated.

"Evaluation of unevenness and uneven gloss" The unevenness and uneven gloss of the surface of the obtained pressure-sensitive adhesive sheet were measured by the following methods.

(Unevenness) The unevenness on the surface of the pressure-sensitive adhesive sheet was visually evaluated according to the following criteria. ⊚: No unevenness ○: Slightly unevenness, but practically no problem △: Unevenness ×: Many unevenness

(Gloss unevenness) The gloss unevenness of the pressure-sensitive adhesive sheet surface was visually evaluated according to the following criteria. ⊚: No gloss unevenness ○: Slight gloss unevenness but practically no problem Δ: Gloss unevenness ×: Many gloss unevenness

"Evaluation of Position Detection Suitability by Photoelectric Tube" The obtained pressure-sensitive adhesive sheet was subjected to label punching to produce a label, and the position detection suitability at the time of label issuing was examined using a label printer manufactured by Teraoka Seiko. (Evaluation criteria) ○: Detectable ×: Not detectable

[0046]

[Table 1]

As is clear from Examples 1 to 4 and Comparative Examples 1, 2 and 3 in Table 1, even if the mixing ratio of the highly beaten pulp and the lightly beaten pulp is proper, the highly beaten pulp is If the beating degree is less than 100 ml CSF, the tear strength becomes insufficient and it is not suitable for practical use. Further, when the beating degree of highly beaten pulp exceeds 250 ml CSF, the light transmittance is lowered, which hinders the position detection by the labeler. Further, when the beating degree of the pulp with a low beating is less than 400 ml CSF, the unevenness and uneven gloss of the surface of the adhesive sheet are not improved. From these results, the range of beating degree of highly beaten pulp is 100 to 250 ml CSF.
And, the range of beating degree of shallow beating pulp is 400mlC
It must be SF or higher.

Further, as is clear from Examples 1 to 4 and Comparative Examples 4 and 5, even if the beating degree of the pulp is proper, the pulp having the beating degree of 400 ml CSF or more is less than 10 parts in the blending amount. In this case, the unevenness and gloss unevenness on the surface of the pressure-sensitive adhesive sheet are not improved, and when it exceeds 40 parts, the unevenness and uneven gloss on the surface of the pressure-sensitive adhesive sheet are improved, but the light transmittance is poor and it is not suitable for position detection by a labeler. . From these results, it is necessary that the blending amount of pulp having a beating degree of 400 ml CSF or more or unbeaten be 40 to 10 parts. In addition,
As shown in Example 5, the present invention is effective regardless of whether glassine paper is subjected to polyethylene laminating treatment.

[0049]

EFFECT OF THE INVENTION The release paper of the present invention has a light-transmitting property that does not cause any problem in position detection by a labeler having a transmission type position detector, and is a release sheet of an adhesive sheet using a film as a surface base material. When used as, it is possible to provide a high-grade pressure-sensitive adhesive sheet having no unevenness or uneven gloss on the surface. Also. It can be easily produced by mixing two kinds of pulps having different beating degrees with an existing equipment such as a paper machine and making a paper, and is extremely excellent in practicality.

Claims (2)

[Claims] 1. A release paper having a release agent layer on glassine paper, wherein pulp as a raw material of the glassine paper is 90 to 60 parts of wood pulp having a freeness of 100 to 250 ml CSF and free pulp of 400 ml CSF or more to unbeaten wood pulp. A release paper comprising 40 parts. 2. A wood pulp having a beating degree of 100 to 250 ml CSF is a softwood kraft pulp, and a beating degree of 400 ml.
The release paper according to claim 1, wherein the wood pulp not less than CSF or unbeaten is a hardwood kraft pulp.