JPH10264331A - Release paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release paper wherein a release agent can be applied without any cissing to polyolefin laminated paper in which a polyolefin film is laminated on base paper or a release base material of a polymer film, adhesion of a release base material to a release agent layer is excellent, and required release force and adhesion force can be obtained. SOLUTION: A release paper is so constituted that a polyolefin laminated paper in which a polyolefin film is laminated on a base paper, or a polymer film is used as a release base material, and a release agent layer is formed at least on one side face of the release base material. In this case, the release agent layer is composed of emulsion silicone and styrenebutadiene copolymer latex as a main constituent. Further, the release agent layer contains 300-500 pts.wt. of styrenebutadiene copolymer latex to 100 pts.wt. of emulsion silicone. Furthermore, the styrene-butadiene copolymer is selected from that of which a glass transition temperature is -50 deg.C or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a release paper, and more particularly, to a release paper used for adhesive paper. More specifically, a release agent can be applied to a polyolefin laminated paper obtained by laminating a polyolefin film on a base paper or a release substrate of a polymer film without repelling, and the adhesion between the release substrate and the release agent layer is good. And a release paper capable of obtaining desired release force and adhesive force.

[0002]

2. Description of the Related Art Adhesive paper is used for labels, stickers, stickers,
It is used for a wide range of applications such as commercial use, office use, home use, etc. as patches. This adhesive paper is generally formed by laminating a surface substrate, an adhesive layer, and a release paper in this order. Paper, film, metal foil, etc. are used as the surface substrate, and the release paper is applied to a release substrate such as high-density paper such as glassine paper, clay-coated paper, polyethylene laminated paper, etc. What formed the layer is used.
Examples of the release agent include a silicone compound, a fluorine compound, an aminoalkyd compound, a polyester compound, and the like. The release agent is used as an emulsion type, a solvent type, or a non-solvent type, and a typical material is a silicone compound. For the pressure-sensitive adhesive layer, various types of pressure-sensitive adhesives such as rubber-based, acrylic-based, and vinyl ether-based, solvent-based, and solvent-free adhesives are used.

At present, the above-mentioned release agent is generally obtained by diluting a silicone resin with a solvent, that is, applying a so-called solvent-type silicone to a release substrate. The reason is that
Usually, the molecular weight of the solvent type silicone is hundreds of thousands, and when this is applied to a release substrate, it is diluted with a solvent and adjusted to a viscosity suitable for each coating apparatus. Therefore, the amount of liquid applied to the release substrate is large, and leveling to the release substrate is easy, and a uniform film can be easily formed. Therefore, the performance of the release agent can be easily maximized.

On the other hand, in recent years, there has been a strong demand for consideration of safety and pollution, and there has been a strong demand for solvent-free release agents from the viewpoint of maintaining the health of workers. Is being done.

However, since the solventless silicone is applied at a concentration of 100%, the amount of liquid applied to the release substrate is small. Therefore, when using solventless silicone,
A thinner uniform release agent film must be formed on the release substrate as compared to solvent-based silicone. As a coating method for this purpose, a multi-stage roll coater is used. As the current method of applying solvent-type silicone,
Since bar coaters and gravure coaters are used, coating equipment must be remodeled in order to eliminate the use of solvent for silicone, which imposes a heavy economic burden. Therefore, an emulsion type silicone that can be coated with the current coating equipment is being studied.

[0006] When the emulsion type silicone is used as a release substrate, a clay coat type in which an undercoat layer is formed by applying a paint mainly composed of an inorganic pigment and an organic adhesive to the surface of glassine paper or base paper is used as a substrate. A uniform and thin release agent layer can be formed similarly to the solvent type silicone. However, when a polyethylene laminate paper or a polymer film such as polypropylene or polyethylene terephthalate is used as the release substrate, when only the emulsion type silicone is applied to the release substrate, cissing occurs and a uniform release agent layer is obtained. However, the force applied when the surface substrate with the pressure-sensitive adhesive layer is peeled from the release paper, that is, a phenomenon in which the peeling force increases, occurs. In addition, the adhesion between the release base material and the emulsion type silicone is insufficient, and the silicone comes off from the release base material and adheres to the pressure-sensitive adhesive layer, thereby causing a problem such as a decrease in adhesive strength.

For this reason, a method has been used in which a water-soluble polymer such as polyvinyl alcohol, carboxymethylcellulose, starch or the like is mixed with an emulsion type silicone, and the mixture is applied to a release substrate of polyethylene laminated paper or a polymer film. However, even when these water-soluble polymers are mixed and used, repelling when applied to base paper or adhesion to a base material cannot be said to be sufficient, and a heavy peeling phenomenon and a decrease in adhesive strength occur.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to use a polyolefin laminated paper obtained by laminating a polyolefin film on a base paper, or a polymer film as a release substrate, and apply emulsion type silicone to the release substrate without repelling. The present invention relates to a release paper which can be used, has good adhesion between a release substrate and a release agent, and does not cause a heavy release phenomenon or a decrease in adhesive strength.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the present situation, and as a result, have found that a release agent layer is formed of an emulsion type silicone (hereinafter referred to as emulsion silicone).
It has been found that the object of the present invention can be achieved by using styrene and styrene-butadiene copolymer latex as main components, and the present invention has been completed.

The present invention relates to a polyolefin laminated paper obtained by laminating a polyolefin film on base paper, or
A release paper that can be applied to a polymer film without repelling and has good adhesion between a release substrate and a release agent. The main components of the release agent are emulsion silicone and a styrene-butadiene copolymer latex. .

According to the present invention, there is provided a polyolefin laminated paper obtained by laminating a polyolefin film on a base paper, or a release paper comprising a polymer film as a release substrate and a release agent layer formed on at least one surface of the release substrate. The present invention also provides a release paper containing an emulsion silicone and a styrene-butadiene copolymer latex as main components, and a release agent layer containing the styrene-butadiene copolymer latex in an amount of 30 to 500 parts by weight per 100 parts by weight of the emulsion silicone. The present invention is a release paper characterized in that the styrene-butadiene copolymer latex has a glass transition temperature of -50 ° C or higher.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The release paper of the present invention uses a polyolefin laminate paper obtained by laminating a polyolefin film typified by polyethylene or polypropylene on a base paper, or a polymer film as a release substrate, and peels off at least one surface of the release substrate. In the release paper on which the agent layer is formed,
Release paper characterized in that the main components of the release agent layer are emulsion silicone and styrene-butadiene copolymer latex.

[0013] Silicones generally used for release paper are classified into solvent type, emulsion type and non-solvent type according to their forms.
It is classified into ultraviolet curing type and electron beam curing type. The solvent type includes a condensation reaction type and an addition reaction type which cure by heat, and the non-solvent type includes an addition reaction type, an ultraviolet curing type and an electron beam curing type. In the emulsion type used in the present invention, there are a condensation reaction type and an addition reaction type, like the solvent type, and the addition reaction type is preferably used.

In the condensation reaction type, silanol polydimethylsiloxane at both ends is reacted with polymethylhydrogensiloxane or polymethylmethoxysiloxane in the presence of a catalyst such as a tin compound, whereas the addition reaction type is A dimethylsiloxane / methylvinylsiloxane copolymer is reacted with polymethylhydrogensiloxane in the presence of a platinum catalyst, and an addition reaction is caused by heating to form an ethylene bond. By-products are generated as in the condensation reaction type. It is more preferably used because it is easy to handle.

The styrene-butadiene copolymer latex used in the present invention is not particularly limited, and a usual styrene and butadiene monomer is emulsified and dispersed in water with a surfactant, and a radical polymerization catalyst is added thereto. Polymerizes.
The ratio of styrene / butadiene in the styrene-butadiene copolymer, the amount of the functional group, the particle size, the gel content, and the like are not particularly limited, and may be any of those usually used for coated paper.

In the present invention, a mixture of an emulsion silicone and a styrene-butadiene copolymer latex is used as a coating liquid for a release agent layer. When a polyolefin laminate paper or a polymer film is used as a release substrate, When the emulsion silicone alone is used, repelling occurs at the time of coating, and a uniform coated surface cannot be obtained. In addition, the adhesion to the substrate is insufficient, and the silicone falls off from the substrate. Therefore, polyvinyl alcohol and carboxymethyl cellulose are used in a mixture with emulsion silicone.

Water-soluble polymers such as polyvinyl alcohol and carboxymethylcellulose are hydrophilic and are composed of cellulose such as glassine paper used as a usual release substrate.
Adhesion to a cissing or substrate at the time of coating becomes good. However, since the polyolefin laminated paper and the polymer film are hydrophobic polymers, the contact angle of the water-soluble polymer becomes large, and the adhesiveness to repelling and the substrate during coating becomes insufficient. As described above, when the water-soluble polymer has high hydrophilicity of the substrate, repelling and poor adhesion do not occur. However, as the hydrophobicity of the substrate increases, repelling and poor adhesion tend to occur.

On the other hand, the styrene-butadiene copolymer latex is a hydrophobic polymer emulsion,
The contact angle is smaller for hydrophobic substrates such as polyolefin laminated paper and polymer films. In addition, as the water-soluble polymer increases the hydrophobicity of the substrate, the wettability of the substrate decreases, but the hydrophobic polymer emulsion having a hydrophobic functional group in the molecule has a higher wettability than the water-soluble polymer. Decrease is small. In other words, for a substrate having a large hydrophobicity, a substrate having a hydrophobic functional group has a larger wetting force, and therefore does not cause problems such as repelling during coating and poor adhesion to the substrate.

The weight ratio of the solid content of the emulsion silicone and the styrene-butadiene copolymer latex is not particularly limited.
Preferably, the styrene-butadiene copolymer latex is in the range of 30 to 500 parts by weight based on parts by weight. If the amount is less than 30 parts by weight, the amount of the styrene-butadiene copolymer latex in the release agent layer is insufficient,
No effect is obtained on the adhesion to repelling or the substrate. 50
If the amount exceeds 0 parts by weight, the amount of the emulsion silicone is insufficient, and an appropriate peeling force cannot be obtained.

The styrene-butadiene copolymer latex of the present invention is not particularly limited, but preferably has a glass transition temperature of -50 ° C or higher. If the glass transition temperature is lower than −50 ° C., blocking occurs, which is not preferable. If the glass transition temperature exceeds 40 ° C., the film-forming ability is inferior, the film becomes hard, and the adhesion to the substrate may be deteriorated.

The amount of the release agent of the present invention is desirably adjusted so as to be in the range of about 0.3 to 5.0 g / m ^{2 on} one side by dry weight. If it is less than 0.3 g / m ² , a desired peeling force cannot be obtained, and if it exceeds 5.0 g / m ² , the effect is saturated and it is not economically preferable. Further, as a coating apparatus for forming a release agent layer, for example, various coaters for applying a general release agent such as a bar coater and a gravure coater or a printing machine are appropriately used.

In general, as a release substrate, high-density base paper such as glassine paper, clay-coated paper, kraft paper or woodfree paper, etc., for example, casein, dextrin, starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, Styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, acrylate copolymer natural or synthetic resin and pigment as main components Polyolefin-laminated paper in which a synthetic resin such as polyethylene or polypropylene is laminated on a base material provided with a sealing layer, or kraft paper or woodfree paper,
Alternatively, a polymer film such as polypropylene and polyethylene terephthalate may be mentioned, and the present invention is particularly effective for a release substrate having poor wettability such as a polyolefin laminate paper and a polymer film.

As long as the object of the present invention is not impaired, pigments such as kaolin, clay, aluminum hydroxide and calcium carbonate can be used. Of course, two or more pigments can be used in combination. In addition, hydrocarbon-based, fatty acid-based, fatty acid amide-based, ester-based, alcohol-based, lubricants such as metal soaps, wetting agents, defoamers, coloring agents, fluidity regulators, water-proofing agents, oil-proofing agents, and curing agents And the like are appropriately blended, and two or more kinds of auxiliaries can be used in combination.

The method of using the release paper of the present invention to form an adhesive paper is carried out according to a conventional method, for example, natural rubber, styrene-butadiene copolymer, styrene-isoprene block copolymer, recycled rubber, synthetic rubber, etc. Rubber-based, acrylic-based, silicone-based pressure-sensitive adhesives are appropriately used. These pressure-sensitive adhesives are applied in the form of a solvent system, an aqueous emulsion system, a hot melt system, a liquid curable type or the like, for example, by a knife coater, a roll coater, a die coater, a gravure coater, screen printing or the like. In this case, the coating amount is 10 to 40 g / m ² in terms of dry weight, more preferably 1 to 40 g / m ² .
It is adjusted within a range of about 5 to 25 g / m ² . By the way, 10
If it is less than g / m ² , the effect as an adhesive layer is poor,
If the amount exceeds 40 g / m ² , the effect is saturated, which is not economically preferable.

Examples of the surface substrate include cast coated paper, art paper, coated paper, woodfree paper, thermal paper,
There are synthetic paper, vapor-deposited paper, cloth, nonwoven fabric, metal foil, various polymer films, and the like, which can be used as appropriate according to the use and purpose.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but of course, the present invention is not limited to these examples. Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 (1) Production of release base material A low-density polyethylene (manufactured by Sumitomo Chemical Co., Ltd.) melted on high-quality paper having a basis weight of 70 g / m ² was laminated by a laboratory melt extruder and used as a release base material. Was prepared. As a result of observing the cross section of this polyethylene laminated paper with a scanning electron microscope, the thickness of the polyethylene film layer was 18 microns.

(2) Production of Release Paper An addition-reaction emulsion silicone (trade name: X-52-195, manufactured by Shin-Etsu Chemical Co., Ltd.) is formed on the obtained release base material.
100 parts, 5 parts of a platinum-based catalyst (CAT-PM-10), styrene-butadiene copolymer latex (Polylac 5
18, glass transition temperature -36 ° C, manufactured by Mitsui Toatsu Chemicals)
00 parts, wetting agent (Lapisol B-07, manufactured by NOF Corporation)
The mixed solution composed of 5 parts was coated with a bar coater so that the dry weight was 0.8 g / m ² . The obtained release paper was evaluated for cissing on the emulsion silicone coated surface and adhesion to the substrate, and the results are shown in Table 1.

(3) Production of pressure-sensitive adhesive paper An acrylic emulsion-type pressure-sensitive adhesive (trade name: Nicazole L-144, manufactured by Nippon Carbide Co.) was applied to the obtained release paper by a reverse roll coater to a dry weight of 22 g / m ^2. After coating and drying as described above, high-quality paper having a basis weight of 64 g / m ² was attached to obtain an adhesive paper. The peel strength and adhesive strength of the obtained pressure-sensitive adhesive paper were evaluated, and the results are shown in Table 1.

Example 2 In the production of the release paper of Example 1, a styrene-butadiene copolymer latex (Polylac 518, glass transition temperature -36 ° C., manufactured by Mitsui Toatsu Chemicals) was replaced with a styrene-butadiene copolymer latex ( Release paper and adhesive paper were obtained in the same manner as in Example 1 except that P-6873, a glass transition temperature of 6 ° C., manufactured by Sumika A & L) was used. With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength and the adhesive strength were evaluated in the same manner as in Example 1.

Example 3 A release paper and an adhesive paper were obtained in the same manner as in Example 1 except that the polyethylene laminated paper was changed to a 75 micron polyethylene terephthalate film in the production of the release substrate of Example 1. About the obtained release paper and adhesive paper, cissing of the coated surface, adhesion to a substrate, release force,
The adhesive strength was evaluated, and the results are shown in Table 1.

Example 4 Except that 200 parts of styrene-butadiene copolymer latex (Polylac 518, glass transition temperature -36 ° C., manufactured by Mitsui Toatsu Chemicals) was changed to 400 parts in the production of the release paper of Example 1. In the same manner as in Example 1, release paper and adhesive paper were obtained. With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength, and the adhesive strength were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 In the production of the release paper of Example 1, styrene-butadiene copolymer latex (Polylac 518, glass transition temperature -36 ° C., manufactured by Mitsui Toatsu Chemicals, Inc.) was converted to polyvinyl alcohol (trade name: PVA117, trade name). A release paper and an adhesive paper were obtained in the same manner as in Example 1 except for changing to Kuraray Co., Ltd.). With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength, and the adhesive strength were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 In the production of the release paper of Example 1, styrene-butadiene copolymer latex (Polylac 518, glass transition temperature -36 ° C., manufactured by Mitsui Toatsu Chemicals, Inc.) was replaced with carboxymethyl cellulose (trade name: Cellogen WSC). , Manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to obtain release paper and adhesive paper in the same manner as in Example 1. With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength, and the adhesive strength were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 3 In the production of the release paper of Example 1, styrene-butadiene copolymer latex (Polylac 518, glass transition temperature -36 ° C., manufactured by Mitsui Toatsu Chemicals, Inc.) was oxidized starch (trade name: ACE A) , Manufactured by Oji Cornstarch Co., Ltd.) to obtain release paper and adhesive paper in the same manner as in Example 1. With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength, and the adhesive strength were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 4 In the production of the release paper of Example 1, a coating liquid for a release agent layer was added to an addition-reaction emulsion silicone (trade name: X-52-
195, Shin-Etsu Chemical Co., Ltd.) 100 parts, platinum-based catalyst (C
AT-PM-10) Example 1 except that only 5 parts were changed.
In the same manner as above, a release paper and an adhesive paper were obtained. With respect to the obtained release paper and pressure-sensitive adhesive paper, the repellency of the coated surface, the adhesion to the substrate, the peeling strength, and the adhesive strength were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

The release paper obtained in Examples and Comparative Examples,
Each evaluation test described below was performed on the adhesive paper. (1) Repelling The silicone-coated surface of the obtained release paper was observed, and the degree of repelling was visually evaluated. (Evaluation criteria) 〇: No repelling is observed on the silicone-coated surface. Δ: Repelling was slightly observed on the silicone-coated surface. ×: Repelling of the silicone-coated surface is observed on the entire surface. (2) Adhesion to Substrate The silicone-coated surface of the obtained release paper was rubbed five times with a finger to evaluate whether the silicone was removed from the substrate. (Evaluation criteria) 〇: The silicone does not fall off the substrate at all. Δ: Silicone is slightly removed from the substrate. X: Silicone falls off the substrate considerably. (3) Peeling force 10 cm x length of adhesive paper with machine direction as long side
Prepare a 5 cm sample and use the INTESCO MODEL
In 2001, the peeling force was measured when the film was peeled at a tensile angle of 180 degrees in the flow direction under the test conditions of a peeling speed of 0.3 m / min. (4) Adhesive force Adhesive force was measured based on the measuring method of normal adhesive force of JIS Z-0237. (Unit: g / 25mm)

[0038]

[Table 1]

[0039]

As is clear from Table 1, the release paper of the present invention can be applied to a polyolefin laminated paper obtained by laminating a polyolefin film on a base paper or a polymer film without repelling, and the release base It is a release paper that has good adhesion between a material and a release agent and can obtain desired release strength and adhesive strength.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09D 183/04 C09D 183/04 D21H 27/00 C09J 7/02 Z // C09J 7/02 D21H 5/00 B

Claims (3)

[Claims] 1. A polyolefin laminated paper obtained by laminating a polyolefin film on a base paper, or a release paper using a polymer film as a release substrate and a release agent layer formed on at least one surface of the release substrate, wherein the release agent layer is And a release paper comprising an emulsion type silicone and a styrene-butadiene copolymer latex as main components. 2. The method of claim 1, wherein said release agent layer is an emulsion type silicone 1
The release paper according to claim 1, which contains 30 to 500 parts by weight of styrene-butadiene copolymer latex based on 00 parts by weight. 3. The release paper according to claim 1, wherein the styrene-butadiene copolymer has a glass transition temperature of -50 ° C. or higher.