JP2020116888A - Peeling sheet - Google Patents

Abstract

To provide a peeling sheet that achieves light peeling at high speed peeling while maintaining a certain level of peeling at low speed peeling.SOLUTION: A peeling sheet has a silicone peeling agent layer on at least one surface side of a substrate layer, the silicone peeling agent layer containing 0.5-30.0 wt.% of silicone resin fine particles, the silicone resin fine particles with an average particle size of 0.1-1.0 μm.SELECTED DRAWING: None

Description

The present invention relates to a release sheet in which a silicone release agent layer containing silicone resin fine particles is formed on at least one side of a base material layer.

Conventionally, single-sided tape used for packaging, double-sided tape used for joining parts for home appliances and automobiles, display/marking uses (labels, stickers), industrial use (masking film for automobiles, marking for building materials) Film, etc.), pharmaceutical-related applications (sticking plasters, patches, etc.), electronic material applications (flexible printed circuit boards, etc.), engineering material applications (flat panel displays and mobile-related applications), A release sheet is attached as a protective material.

The release sheet is generally manufactured by applying a release agent to at least one surface of the base material. Silicone-based release agents are most commonly used as the release agent, and when the base material used for the release sheet is paper, it is usually used between the paper and the release agent layer to prevent the release agent from penetrating into the paper. Provide a sealing layer.

As the release characteristics required for a release sheet, light release with high-speed release is required in order to cope with high-speed rewinding and high-speed label scrap removal.

In Patent Document 1, a branched organopolysiloxane having a vinyl group at the terminal of the molecular chain, an organohydrogenpolysiloxane having at least three hydrogen atoms bonded to silicon atoms in the molecule, and a platinum group metal-based catalyst are essential. There is described a release paper that is lightly peeled by low-speed peeling and high-speed peeling by using a solventless silicone release agent as a component.
In Patent Document 2, by laminating a first release agent layer containing no fine particles on a base film and a second release agent layer containing inorganic fine particles and/or polymer fine particles, the peeling force is small and the adhesion is low. A peeling film is described in which the peeling force is less likely to increase even after a lapse of time in the state of being stuck to the agent layer.
In Patent Document 3, a release agent layer containing silicone resin fine particles having an average particle diameter of 0.1 to 15 μm is formed on the surface of the base material to have a thickness of 1 to 20 μm, thereby controlling appropriate release strength. A release sheet is described which is possible and whose release properties do not change over time.

JP-A-9-78032 JP, 2017-61081, A JP-A-4-301491

Since the release paper shown in Patent Document 1 is a low-speed release and a light release, the adhesive layer may float from the release sheet when rolled into an adhesive tape, or may be necessary in addition to the residue when removing the residue of the adhesive sheet. Problems such as peeling of parts also tend to occur.
The release film disclosed in Patent Document 2 has two release agent layers laminated on a base material, and it is difficult to say that manufacturing with such a composition is industrially advantageous because the process becomes complicated.
Further, in the release sheet shown in Patent Document 3, the thickness of the release agent layer is formed to be 1 to 20 μm, and when the coating amount is set, the amount of the release agent to be used increases and the price is reduced. Will be disadvantageous.

Under these circumstances, the problem to be solved by the present invention is to provide a release sheet that realizes light release by high-speed release while maintaining a release level to some extent in low-speed release.

The present invention is a release sheet having a silicone release agent layer on at least one side of a substrate layer,
The silicone release agent layer contains 0.5 to 30.0 mass% of silicone resin fine particles,
It is a release sheet in which the average particle diameter of the silicone-based resin fine particles is 0.1 to 1.0 μm.

According to the present invention, it is possible to provide a release sheet capable of maintaining a release level to some extent to prevent floating of an adhesive layer in low-speed release and improving rewindability by light release in high-speed release.

(Outline of the present invention)
A release sheet according to an embodiment of the present invention is a release sheet having a silicone release agent layer on at least one side of a base material layer,
The silicone release agent layer contains 0.5 to 30.0 mass% of silicone resin fine particles,
It is a release sheet in which the average particle diameter of the silicone-based resin fine particles is 0.1 to 1.0 μm.
Unless otherwise specified in this specification, “A to B” indicating a numerical range means “A or more and B or less”.
The thickness of the silicone release agent layer may be 0.4 μm or more and less than 1.0 μm.

(Layer structure of release sheet)
In the release sheet according to one embodiment of the present invention, a silicone release agent layer containing fine particles of silicone resin is formed on at least one surface side (first surface) of a base material layer.
The layer structure on the other one surface (second surface) side of the base material layer is not particularly limited, and for example, it may not have any layer or may have a silicone release agent layer. .. The silicone release agent layer on the second surface may or may not contain the silicone resin fine particles.

(Base material layer)
The base material forming the base material layer in the release sheet according to one embodiment of the present invention is not particularly limited, and various plastic films, papers and the like can be mentioned.
When paper is used as the base material, clay-coated paper, glassine paper, or the like that has been subjected to sealing treatment, or polyethylene or the like that has been laminated is desirable.
Examples of the plastic film include polyester films, polyamide films, polyolefin films, polyethylene films, polypropylene films, polyethylene terephthalate films, and the like. In either type of film, both an unstretched film and a stretched film can be used, but a stretched film is generally preferable because it has a higher melting point.

The base material layer may be one layer or two or more layers. In the case of two or more layers, the types of base materials may be the same or different. In the case of two or more layers, known methods such as a dry laminating method, a wet laminating method and an extrusion laminating method may be used for laminating between the base materials.

(Silicone release agent layer)
The silicone release agent constituting the silicone release agent layer in the release sheet according to the present embodiment is not particularly limited, and among solvent addition type silicone release agent, solventless addition type silicone release agent, solvent condensation type silicone release agent Can be selected as appropriate. From the viewpoint of coatability and curability, a solvent-added silicone release agent is desirable.
The coating amount of the silicone release agent is preferably 0.4 μm or more and less than 1.0 μm as the thickness of the silicone release agent layer in terms of performance and cost, and more preferably 0.5 μm to 0.8 μm.
When the thickness of the silicone release agent layer is less than 0.4 μm, the original release performance cannot be exhibited and heavy release is likely.
If the thickness of the silicone release agent layer is 1.0 μm or more, the amount of silicone itself used increases and the amount of energy required for curing also increases, which is disadvantageous in terms of cost.

(Silicone-based resin particles)
The silicone resin fine particles can be produced, for example, by hydrolytic condensation of alkyltrialkoxysilane. Examples of the alkyltrialkoxysilane used include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, and methyltriisopropoxysilane.
A specific method for producing the silicone resin fine particles is, for example, using hydrolyzable silane as a starting material, hydrolyzing with water, and growing the fine particles in water while forming a siloxane bond by a condensation reaction of the hydrolyzate. The aqueous dispersion containing the grown particles can be dried by a spray dryer method to obtain a powder of silicone resin fine particles. Further, by substituting the aqueous dispersion with an organic solvent, it is possible to obtain silicone resin fine particles dispersed in the organic solvent.

As the silicone resin fine particles, for example, polymethylsilsesquioxane particles (produced by Chugoku Kako Co., Ltd.) can be used.

The content of the silicone resin fine particles contained in the silicone release agent layer with respect to the silicone release agent layer is 0.5 to 30.0% by mass. Further, from the viewpoint of cost and quality stability, 1.0 to 10.0 mass% is preferable, and 1.0 to 5.0 mass% is more preferable.

The silicone resin fine particles have an average particle diameter of 0.1 to 1.0 μm. In the present specification, the average particle size refers to “number average particle size”. For example, the number average particle diameter (μm) of the silicone resin fine particles is measured by diluting the silicone resin fine particles with ion-exchanged water and measuring with a light scattering particle size distribution analyzer (“NicompMODEL380” manufactured by Particle Sizing Systems). Obtainable.

(Method of manufacturing release sheet)
The release sheet according to one embodiment of the present invention is, for example, as shown in Examples, a silicone release agent obtained by applying a silicone release agent containing silicone resin fine particles to a base material forming a base material layer. It can be manufactured by forming layers.

The peeling load of the release sheet according to one embodiment of the present invention can be measured using a peeling tester, for example, as shown in the examples.

Examples will be shown below to describe the embodiments of the present invention in more detail. Of course, the present invention is not limited to the following examples, and it goes without saying that various aspects are possible in details. Furthermore, the present invention is not limited to the above-described embodiments, various modifications can be made within the scope of the claims, and the present invention is also applicable to embodiments obtained by appropriately combining the disclosed technical means. It is included in the technical scope of the invention. Moreover, all the documents described in this specification are incorporated by reference.

The methods for measuring physical properties in Examples and Comparative Examples are as follows. In the examples,% represents mass% unless otherwise specified.

(1) Average Particle Size A dispersion of silicone resin fine particles is diluted with ion-exchanged water and measured with a light scattering particle size distribution measuring device (“NicompMODEL380” manufactured by Particle Sizing Systems), and the number average particle size (μm) is measured. Was determined, and this value was defined as the average particle diameter of the silicone resin fine particles.

(2) Peeling load (unit: g/25mm)
The pressure-sensitive adhesive BPS-8170 (manufactured by Toyochem Co., Ltd.) was applied on the surface of the silicone release agent layer of the release sheet at a thickness of 200 μm using an applicator. After heating in an oven at 70° C. for 5 minutes, the sheet was taken out of the oven, and high-quality paper (78 g/m ² ) was attached to the adhesive surface using a hand roller.
The sample was sandwiched between two glass plates, a pressure of 1.96 kPa was applied, and the sample was stored in an oven at 70° C. for 20 hours. Then, after curing at 23° C. and 65% RH for 1 hour or more, three cut test pieces having a size of 200 mm×25 mm were prepared. Then, the peeling load was measured under the following conditions using a high-speed peeling tester TE-701 (manufactured by Tester Sangyo Co., Ltd.). The results shown in Table 1 and Table 2 are average values of the values obtained from the three test pieces. The smaller the peeling load, the better.
Tensile speed: 0.3, 5, 10, 30, 50, 100 (m/min)
Peeling angle: 180°

(3) Residual adhesion rate (unit: %)
A Teflon (registered trademark) plate, which had been cleaned by wiping the surface with acetone and then wiping with ethyl alcohol, to a 25 mm wide polyester adhesive tape No. 31B (manufactured by Nitto Denko Corporation) was attached. After pressing back and forth once with a 2 kgf rubber roller, it was sandwiched between glass plates and a load of 1.96 kPa was applied. It was stored in an oven at 70° C. for 20 hours. Then, after curing at 23°C and 65% RH for 1 hour or more, remove the tape from the Teflon (registered trademark) plate, use a stainless steel plate (SUS301) specified in JIS G4305, and use water resistant abrasive paper (P280) specified in JIS R6253. The test piece was attached to a polished standard plate, pressure-bonded back and forth once with a 2 kgf rubber roller, and the adhesive force after 30 minutes was measured under the following conditions using a high-speed peel tester TE-701. The average value of the three samples was taken as the basic adhesive strength.
Peeling speed: 0.3 m/min Peeling angle: 180°
Next, a 25 mm width polyester adhesive tape No. 31B was adhered, and after reciprocally pressure-bonded with a 2 kgf rubber roller, the adhered portion was cut into a size of 300 mm×25 mm to obtain a test piece. After the step of sandwiching between the glass plates, the residual adhesive strength (average value of 3 samples) was measured by the same method as the basic adhesive strength.
Further, the residual adhesion rate was calculated using the following formula.
Residual adhesion rate (%)=(residual adhesion)/(basic adhesion)×100

[Example 1]
A solvent-added silicone release agent containing silicone resin particles was applied to one surface of the base material to prepare a release sheet. Details of the base material, the silicone release agent, and the silicone resin fine particles are as follows. Table 1 shows the physical property values of the obtained release sheet.
Base material: polyethylene laminated paper (hereinafter referred to as "PE laminated paper")
Silicone release agent: KS847 (manufactured by Shin-Etsu Chemical Co., Ltd.)
Silicone resin fine particles: 1.0 μm polymethylsilsesquioxane particles (made by Chugoku Kako Co., Ltd.)
Addition amount of silicone resin fine particles: 10% by mass (the amount of the silicone release agent is 100% by mass)

[Example 2]
A release sheet was produced in the same manner as in Example 1 except that the silicone resin fine particles were changed to 0.45 μm polymethylsilsesquioxane particles (produced by Chugoku Kako Co., Ltd.).
Table 1 shows the physical property values of the obtained release sheet.

[Example 3]
A release sheet was produced in the same manner as in Example 1 except that the silicone resin fine particles were changed to 0.1 μm polymethylsilsesquioxane particles (produced by Chugoku Kako Co., Ltd.).
Table 1 shows the physical property values of the obtained release sheet.

[Example 4]
A release sheet was produced in the same manner as in Example 1 except that the amount of the silicone resin fine particles added was changed to 5% by weight (the amount of the silicone release agent was 100% by weight).
Table 1 shows the physical property values of the obtained release sheet.

[Example 5]
A release sheet was produced in the same manner as in Example 2 except that the addition amount of the silicone resin fine particles was changed to 5% by weight (the amount of the silicone release agent was 100% by weight).
Table 1 shows the physical property values of the obtained release sheet.

[Example 6]
A release sheet was produced in the same manner as in Example 3 except that the amount of the silicone resin fine particles added was changed to 5% by weight (the amount of the silicone release agent was 100% by weight).
Table 1 shows the physical property values of the obtained release sheet.

[Example 7]
A release sheet was produced in the same manner as in Example 5 except that the amount of the silicone resin fine particles added was changed to 30% by weight (the amount of the silicone release agent was 100% by weight).
Table 1 shows the physical property values of the obtained release sheet.

[Example 8]
A release sheet was produced in the same manner as in Example 5, except that the addition amount of the silicone resin fine particles was changed to 1% by weight (the amount of the silicone release agent was 100% by weight).
Table 1 shows the physical property values of the obtained release sheet.

[Comparative Example 1]
A solvent-added silicone release agent containing no silicone-based resin particles was applied to one surface of the base material to prepare a release sheet. Details of the base material and the silicone release agent are as follows. Table 1 shows the physical property values of the obtained release sheet.
Base material: polyethylene laminated paper Silicone release agent: KS847

[Example 9]
A release sheet was produced in the same manner as in Example 2 except that the silicone release agent was changed to SRX211 (manufactured by Toray Dow Corning Co., Ltd.), which is a solvent-added type silicone release agent.
The physical properties of the obtained release sheet are shown in Table 2.

[Comparative Example 2]
A release sheet was produced in the same manner as in Comparative Example 1 except that the silicone release agent was changed to SRX211.
The physical properties of the obtained release sheet are shown in Table 2.

[Example 10]
A release sheet was produced in the same manner as in Example 2 except that the substrate was changed to glassine paper.
The physical properties of the obtained release sheet are shown in Table 2.

[Comparative Example 3]
A release sheet was produced in the same manner as in Comparative Example 1 except that the substrate was changed to glassine paper.
The physical properties of the obtained release sheet are shown in Table 2.

[Example 11]
A release sheet was produced in the same manner as in Example 2 except that the base material was changed to a polyester film (referred to as PET).
The physical properties of the obtained release sheet are shown in Table 2.

[Comparative Example 4]
A release sheet was produced in the same manner as in Comparative Example 1 except that the base material was changed to a polyester film.
The physical properties of the obtained release sheet are shown in Table 2.

[Example 12]
A release sheet was prepared in the same manner as in Example 7, except that the solvent release type silicone release agent KS560Z (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the silicone release agent.
The physical properties of the obtained release sheet are shown in Table 2.

[Comparative Example 5]
A release sheet was prepared in the same manner as in Comparative Example 1 except that the silicone release agent was changed to KS560Z.
The physical properties of the obtained release sheet are shown in Table 2.

As shown in Table 1 and Table 2, the release sheets of Examples 1 to 12 maintained a certain level of release when the release rate was low. Further, when the peeling speed was high, it was light peeling.

Claims (2)

A release sheet having a silicone release agent layer on at least one side of a base material layer,
The silicone release agent layer contains 0.5 to 30.0 mass% of silicone resin fine particles,
A release sheet in which the average particle diameter of the silicone resin fine particles is 0.1 to 1.0 μm. The release sheet according to claim 1, wherein the silicone release agent layer has a thickness of 0.4 μm or more and less than 1.0 μm.