TWI444290B - A release sheet, a polarizing plate with a release sheet, and a non-substrate double-sided adhesive sheet - Google Patents

Description

Release sheet, polarizing plate with release sheet, and substrateless double-sided adhesive sheet

The present invention relates to a release sheet, a polarizing plate with a release sheet, and a substrateless double-sided adhesive sheet.

In recent years, while the technological advancement of LCD has been remarkable and the screen is large, the luminance of the backlight has been increased, and so-called high-luminance type LCD is spreading. In such an LCD, even if foreign matter and defects (so-called defects) in the respective members constituting the LCD such as a polarizing plate are small, since the display is visually recognized as a bright spot, the inspection accuracy of the lifting defect becomes variable. It is getting more and more important.

For example, the inspection of the defects of the polarizing plate is generally performed by visual inspection by orthogonal polarization. In the orthogonal polarization method, when the two polarizing plates are overlapped with each other such that the alignment main axes are orthogonal to each other to form a matte state, if there is a defect, a bright spot is formed at the place, whereby visual defects can be obtained. an examination.

The polarizing plate is attached to the LCD by attaching it to other components such as liquid crystal cells by an adhesive, and the ease of operation and the like are used as an object. Generally, an adhesive having a release sheet is attached to one surface of the polarizing plate in advance. Such a polarizing plate is usually subjected to a visual inspection by a crossed polarizing method in the case where a peeling sheet is attached. Therefore, in order to prevent the obstacle of the inspection by the orthogonal polarization method, it is known that a film having a small inclination (alignment angle) of the alignment main axis is used for the base material of the release sheet (for example, see Patent Document 1).

Further, it is conventionally known that a release agent layer of a release sheet used in a polarizing plate application is formed by coating a resin composition on one side of a substrate and then heat-hardening. For example, Patent Document 2 (see, for example, Patent Document 2) is used as the oxime resin composition.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-172694

[Patent Document 2] Japanese Patent Laid-Open No. 7-11026

However, when the resin composition described in Patent Document 2 is used to form a release agent layer, in order to improve the hardenability of the release agent layer, it is necessary to increase the curing temperature, and the release sheet substrate often occurs due to such high temperature heating. The heat shrinkage causes a variation in the distribution range (the difference between the maximum value and the minimum value) of the alignment angle. Therefore, even if a film having a small distribution angle of the alignment angle is used as the release sheet substrate, there is a problem that the distribution angle of the alignment angle of the release sheet substrate becomes large after the formation of the release agent layer, and the release sheet The substrate will become an obstacle to the inspection of the orthogonal polarization method, and the inspection accuracy cannot be sufficiently improved. On the other hand, in order to suppress the change in the alignment angle of the release sheet substrate, when the heating temperature at the time of curing is lowered, there is a problem that the release agent layer is not sufficiently cured or the release property of the release agent layer is lowered.

In view of the above, it is an object of the present invention to provide a peeling sheet which is capable of performing high-precision inspection and excellent peeling performance in the inspection of the orthogonal polarizing method when attached to a polarizing plate, and the use of the peeling sheet. A polarizing plate with a release sheet and a double-sided adhesive sheet without a substrate.

The release sheet of the present invention is provided with a release agent layer on one side of the release sheet substrate, wherein the release sheet substrate is a uniaxial or biaxially stretched polyester film; and the release agent layer is an additional reaction type resin. When the composition is formed by curing a film, the reaction-reactive resin composition includes an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms in the molecule, and an MQ resin having an alkenyl group in the molecule; In the release sheet substrate provided with the release agent layer, the distribution of the inclination (alignment angle) of the alignment main axis of the release sheet substrate opposite to the linear axis set in any direction is 5° or less, and the straight line is When the axis is set to the longitudinal direction or the width direction when the polyester film is stretched, the maximum value of the inclination (alignment angle) of the alignment main axis of the release sheet base material is 5 or less.

Preferably, the MQ resin has SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, and CH ₂ =CH(CH ₂ ) _Z (CH ₃ ) ₂ SiO _1/2 units (wherein z represents 0 An anthracene resin having a structure of an integer of ~4).

The polarizing plate with a release sheet according to the present invention is provided in the order of a polarizing plate, an adhesive layer, and a release sheet, and is characterized in that the release sheet is formed by providing a release agent layer on one surface of the release sheet substrate. And the release agent layer is detachably attached to the adhesive layer; the release sheet substrate is a uniaxial or biaxially stretched polyester film; and the release agent layer is a hardened film for the additional reaction type bismuth resin composition. As a result, the additional reaction type oxime resin composition includes an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms in the molecule, and an MQ resin having an alkenyl group in the molecule; and a release agent layer is provided In the release sheet substrate, the distribution of the inclination (alignment angle) of the alignment main axis of the release sheet substrate opposite to the linear axis set in any direction is 5° or less, and the linear axis is set to a polyester film. In the longitudinal direction or the width direction at the time of extension, the maximum value of the inclination (alignment angle) of the alignment main axis of the release sheet base material is 5 or less.

Further, the substrateless double-sided adhesive sheet of the present invention has a light release sheet and a heavy release sheet laminated on both sides of the adhesive layer, wherein the release sheet is provided with a release agent layer on one side of the release sheet substrate. Further, the release agent layer is temporarily fixed to the adhesive layer in a peelable manner; the peeling force with respect to the adhesive layer of the light release sheet is lower than the peeling force of the adhesive layer of the heavy release sheet; The release sheet substrate is a uniaxial or biaxially stretched polyester film; the release agent layer is formed by curing the additional reaction type bismuth resin composition, and the additional reaction type bismuth resin composition contains carbon number in the molecule. An organopolyfluorene having 6 to 10 alkenyl groups and an MQ resin having an alkenyl group in a molecule; and in a release sheet substrate provided with a release agent layer, opposite to a linear axis set in an arbitrary direction The distribution of the inclination (alignment angle) of the alignment main axis of the release sheet substrate is 5° or less, and the alignment of the release sheet substrate is performed when the linear axis is set to the longitudinal direction or the width direction when the polyester film is extended. Slope of the main shaft (alignment angle) The maximum value is 5° or less.

Preferably, the pressure-sensitive adhesive layer is formed of an adhesive having a storage modulus (G') at 23 ° C of 0.3 MPa or more.

In the present invention, by using a predetermined resin composition in a release agent, Even if the release agent layer is hardened at a relatively low temperature, since the hardenability can be further improved, the peeling performance of the release sheet can be further improved. Further, by curing the release agent layer at a low temperature, even after the release agent layer is formed, since the distribution range of the small alignment angle of the release sheet substrate can be maintained, high precision can be performed in the inspection of the orthogonal polarization method. an examination.

The present invention will be described in more detail below using embodiments.

The release sheet according to the embodiment of the present invention has a release layer layer formed on one of the areas of the release sheet substrate, and can be used, for example, in a polarizing plate.

As the release sheet substrate of the release sheet, although a uniaxial or biaxially stretched stretched polyester film having a low distribution range of the alignment (alignment angle) of the main axis is used, it is preferable to use a biaxially stretched extension. Polyester film. In the sample sampled from the release sheet obtained by curing the release agent layer on the release sheet substrate, the distribution angle of the release sheet of the release sheet substrate opposite to the linear axis set in any direction is 5° or less. The best is below 4°. As the polyester film, a uniaxially stretched film in which a strip-shaped film extends in the width direction (or the longitudinal direction) or a biaxially stretched film in which a strip-shaped film extends in the width direction and the longitudinal direction is used. Meanwhile, in the sample sampled as described above, preferably, when the linear axis is set to the longitudinal direction or the width direction of the film when the film is extended, the inclination (alignment angle) of the alignment main axis of the release sheet substrate is the largest. The value is 5° or less. As the polyester film, a PET film, a PEN film or the like is exemplified, but a biaxially stretched PET film is particularly suitable. The reason is because transparency, heat resistance, planarity, and strength are preferred.

The release agent layer of the present embodiment is obtained by applying an additional reaction-type enamel resin composition diluted with a suitable organic solvent to a release sheet substrate, and then applying heat by heating or ultraviolet light. The reactive oxime resin composition is formed by hardening the film. The additional reaction type oxime resin composition is a main component comprising an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms in the molecule, and an MQ resin, a bridging agent, and a catalyst having an alkenyl group in the molecule are added. Further, an additional reaction inhibitor, a adhesion enhancer, or the like may be added as desired. In addition, in hardening and stripping In the process of the agent, when light irradiation such as ultraviolet rays is added to the heating, a photo-starting agent may be added to the above composition. The heating temperature at the time of curing the release agent layer is lower than the heating temperature at the time of curing the usual release agent layer, and preferably, for example, 95 to 105 °C.

As the organopolyfluorene having an alkenyl group having 6 to 10 carbon atoms, an organopolyfluorene having at least two alkenyl groups in one molecule is used. The alkenyl group having 6 to 10 carbon atoms is exemplified by, for example, a hexenyl group or an octenyl group, but is preferably a hexenyl group from the viewpoint of cost. As a specific example of such an organic polyfluorene oxide, those exemplified by the following general formula (I) are used.

R ¹ _a R _(3-a) SiO(R ₂ SiO) _m (PR ¹ SiO) _n SiR _(3-b) R ¹ _b (I)

In the general formula (I), a, b, m, and n are integers, 0≦a≦3, 0≦b≦3, and m≧1, n≧0. R is the same or different monovalent hydrocarbon group having no aliphatic unsaturated bond, and R ¹ is an alkenyl group having 6 to 10 carbon atoms as described above. The monovalent hydrocarbon group of R is exemplified by a carbon number of 1 to 12, preferably 1 to 10, but specifically, an alkyl group such as a methyl group, an ethyl group or a propyl group, or a tolyl group is exemplified. An aryl group such as a phenyl group. However, from the viewpoint of hardenability and peelability, it is preferred that 80% or more of R is a methyl group.

As the MQ resin having an alkenyl group in the molecule, for example, SiO ₂ unit, (CH ₃ ) ₃ SiO _1/2 unit, and CH ₂ =CH(CH ₂ ) _Z (CH ₃ ) ₂ SiO _{1/2 are used.} An anthracene resin having a structure of a unit (wherein, z represents an integer of 0 to 4). The content of the alkenyl group in the molecule of the MQ resin is preferably, for example, 0.5 to 5 mass%. In the present embodiment, by adding the MQ resin to the additional reaction type oxime resin composition, the peeling force of the release agent layer can be increased and set to a desired peeling force. In the resin composition, it is preferable that the MQ resin is added in an amount of 1 to 50 parts by mass with respect to 100 parts of the organic polyoxo group having an alkenyl group having 6 to 10 carbon atoms.

As the bridging agent, for example, a bridging agent having an organic polyoxygen having a hydrogen atom (hydroxyl group) bonded to at least two deuterium atoms in one molecule is used. Specifically, it can be exemplified that the dimethylhydrogenoxy end-blocking of the dioxime-hydrogen oxime-oxygen co-reclosure, the trimethyl methoxy end-blocking of the dioxime oxime oxime co-reclosure, the trimethyl hydrazine The oxy terminal blocks methyl methoxide, poly(oxetane sesquioxane) and the like. In the present embodiment, the cured film is formed by an additional reaction of a hydroxyl group of the bridging agent and an alkenyl group in the oxime resin composition.

The bridging agent is contained in an amount of 0.1 to 100 parts by mass, preferably 0.3 to 50 parts by mass, based on 100 parts by mass of the additional reaction type resin. Meanwhile, the number of hydrogen atoms combined with the ruthenium atom contained in the bridging agent is preferably 1.0 to 5.0 (mole ratio) with respect to the number of alkenyl groups in the additional reaction type oxime resin composition, more preferably It is 1.2~3.0 (Morbi). When the above molar ratio is less than 1.0 and the hardenability of the composition is deteriorated to exceed 5.0, the peeling force of the peeling sheet obtained often becomes excessive.

As the catalyst used for the additional reaction type oxime resin composition, for example, a platinum compound is used. Examples of the platinum-based compound include fine particle-shaped platinum, fine-grained platinum adsorbed on a carbon powder carrier, chlorinated white gold, ethanol-denatured chloroauric acid, and chlorogalic acid olefin complex. , palladium, rhodium catalysts, etc. The platinum-based metal-based catalyst can be added with a platinum-based metal of about 1 to 1000 ppm by mass based on the total amount of the additional reaction-type resin and the bridging agent.

In the present embodiment, by using an organic polyfluorene having an alkenyl group having a carbon number of 6 to 10 on the main component of the release agent, the heating temperature at the time of heat curing of the release agent layer is set to a relatively low temperature. (For example, 95 to 105 ° C), it is also possible to form a release agent layer having excellent hardenability. In this manner, the release agent layer having good curability has excellent peeling strength in terms of stability over time, and when the release sheet is peeled off from the adhesive layer, it is not necessary to completely lower the adhesive force of the adhesive layer, and good residue can be obtained. Then force. Further, by setting the heating temperature at the time of heat curing to a low temperature, since the heat shrinkage of the release sheet substrate can be suppressed and the original alignment property of the substrate can be maintained, the adhesive for the release sheet substrate can be removed as described above. The distribution angle of the alignment angle after the formation of the layer is set to be 5 or less.

The polarizing plate with a release sheet according to an embodiment of the present invention is formed by laminating a polarizing plate (polarizing film), an adhesive layer, and a release sheet. As the release sheet, the release sheet is used, and the release sheet is used. The release agent layer and the adhesive layer are temporarily fixed in a peelable manner. In the polarizing plate with the peeling sheet, about peeling In the release sheet, the longitudinal direction or the width direction of the polyester film at the time of stretching is laminated in accordance with the direction of the polarization axis of the polarizing plate. After the peeling sheet is peeled off, the polarizing plate with the peeling sheet is bonded to the other member by the exposed adhesive layer.

The adhesive for forming the adhesive layer can be used without any limitation as an adhesive for a polarizing plate, but it is preferable to use a storage elastic modulus (G') at 23 ° C of 0.3 MPa or more. Adhesive. The adhesive having a storage modulus (G') of 23 MPa or more at 23 ° C has a high light leakage prevention property, and therefore can be suitably used for polarizing plate applications. The upper limit of the storage modulus (G') at 23 ° C is not particularly limited, but is preferably 50 MPa or less, and more preferably 15 MPa or less. The range of the storage elastic modulus (G') at 23 ° C of the adhesive is particularly preferably 0.35 to 12 MPa, and most preferably 0.5 to 5 MPa.

For example, as disclosed in Japanese Laid-Open Patent Publication No. 2007-197659, the propylene-based cohesive body having a monomer composition ratio of 0.5% by mass or less and activity is included in the monomer containing a carboxyl group. The adhesive material of the curable compound after the irradiation of the energy ray is irradiated with an active energy ray such as ultraviolet rays, and the storage elastic modulus (G') at 23 ° C after the irradiation of the active energy ray is 0.3 MPa or more. Further, the propylene-based cohesive body is preferably a superposed body of, for example, a (meth) acrylate conjugate or a monomer having no carboxyl group.

Further, as an adhesive, for example, as disclosed in Japanese Laid-Open Patent Publication No. H2007-212995, the weight average molecular weight of 1,000,000 is contained in a monomer containing a hydroxyl group-containing monomer at a monomer composition ratio of 10% by mass or less. The propylene-based polymer ((A) component) and the carboxy-containing monomer having a monomer composition ratio of 10% by mass or less and a weight average molecular weight of 1,000,000 or more, a propylene-based polymer (component (B)), and active energy The adhesive material of the wire-curing compound is composed of an active energy ray. The adhesive has a storage modulus (G') of 23 MPa or more at 23 ° C after the irradiation of the active energy ray, and the mass ratio of the component (A) and the component (B) is 100:1 to 100:50. Further, as each monomer composition, it is preferred to have a monomer having a hydroxyl group content of 0.1% by mass or more, and a monomer A monomer having a carboxyl group of 0.1% by mass or more.

These adhesives are formed by applying an adhesive material to a release agent layer such as a release sheet and drying it, and then curing it by irradiation with an active energy ray to form an adhesive layer. The adhesive layer used for the polarizing plate is often peeled off after being attached to the polarizing plate in order to correct the deviation of the bonding. Since the above-mentioned adhesive can maintain a relatively low adhesive force after a long period of time in stability, it can be easily peeled off from the polarizing plate even after being applied to the polarizing plate for a long time. Further, the above-mentioned adhesive has a high cohesive force and hinders the improvement of the peeling force of the release sheet. However, as in the present embodiment, an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms and an olefin are used. The release agent composition of the base MQ resin can sufficiently increase the peeling force of the release sheet.

Further, in the present specification, the weight average molecular weight is a value in terms of polystyrene measured by a Gel Permeation Chromatography (GPC) method. In addition, the storage elastic modulus (G') at 23 ° C is an adhesive having a thickness of 30 μm, and a test piece having a cylindrical shape of 8 mm Φ x 3 mm thick, and is measured by the following conditions using a twisting shear method.

Measuring device: Dynamic viscoelasticity measuring device "DYNAMIC ANALYZER RDAII" manufactured by REOMETRIC

Frequency: 1Hz

Temperature: 23 ° C

A substrate-free double-sided adhesive sheet according to an embodiment of the present invention is one in which one of the adhesive layer layers is peeled off and the other layer is protected. In the substrateless double-sided adhesive sheet, the adhesive layer and the release sheet have the same structure as described above. In the substrateless double-sided adhesive sheet, the release sheet is a so-called heavy release sheet, and the release agent layer and the adhesive layer of the release sheet are detachably attached. The protective sheet is a so-called light release sheet which is composed, for example, of a one-layer release agent layer on the protective sheet substrate, and the release agent layer is detachably attached to the adhesive layer. The release agent layer of the protective sheet is preferably an oxime resin, and particularly preferably an additional reaction type lanthanide resin. The substrate-free double-sided adhesive sheet of the present embodiment is used, for example, in a polarizing plate, and after the protective sheet is peeled off, the exposed adhesive layer is attached. Used in combination with a polarizing plate or the like. At this time, the longitudinal direction or the width direction of the polyester film at the time of the extension is the direction of the polarization axis of the polarizing plate. The substrate-free double-sided adhesive sheet can be protected by a protective sheet for storage before use.

In the polarizing plate with the release sheet and the non-substrate double-sided adhesive sheet, the peeling force of the adhesive layer with respect to the release sheet (heavy release sheet) is preferably 25 to 100 mN/20 mm, more preferably 30 to 30. 90mN/20mm.

In the substrateless double-sided adhesive sheet, the peeling force with respect to the adhesive layer of the protective sheet (light release sheet) is lower than that of the adhesive layer of the release sheet (heavy release sheet), preferably 2~80mN/20mm, more preferably 25~70mN/20mm. When the adhesive force against the adhesive layer of the protective sheet (light release sheet) is set to X [mN/20 mm], and the peeling force with respect to the adhesive layer of the release sheet (heavy release sheet) is set to Y [mN When /20mm], it is preferable to satisfy the relationship of YX>20. By setting the difference in peeling force between the two sheets to a predetermined value or more, it is possible to prevent peeling failure which occurs when the protective sheet is peeled off from the adhesive layer. In addition, the peeling force of the peeling sheet and the protective sheet described here is measured based on JIS-Z0237 as described in detail below.

In each of the embodiments of the present invention, the resin composition and the adhesive material are used, for example, by the GRAVIURE COAT method, the BAR COAT method, the SPARY COAT method, the SPIN COAT method, the KNIFE COAT method, the ROLL COAT method, the DYE COAT method, or the like. The method is applied.

[Examples]

The present invention has been described using the following examples, but the present invention is not limited to the structures of the following embodiments.

[Example 1]

<Production of peeling sheet>

A ruthenium resin solution (manufactured by DOW CORNING Co., Ltd., trade name "LTC-750A") containing an organic polyfluorene having a hexyl group and an organic polyoxyloxy group having a hydroxy group is converted into 30 parts by a solid content, and is provided. The ethyl ester MQ (manufactured by DOW CORNING Co., Ltd., trade name "SD7292") was diluted and mixed with each other in a solid content of 30 parts by mass to form a solid content concentration in the toluene solvent of 2.0% by mass. A platinum-based catalyst (manufactured by DOW CORNING Co., Ltd., trade name "SRX-212") of a three-mass portion was added to the solution to obtain a solution of an additional reaction-type oxime resin composition. The PET film having a film thickness of 0.1 μm after drying in a width direction and a longitudinal direction of a thickness of 38 μm (manufactured by DOW CORNING Co., Ltd., trade name " Above a R64") After the coating, the composition was cured by heating and drying at 100 ° C for 30 seconds to obtain a release sheet in which a release agent layer was formed on the release sheet substrate.

<Production of polarizing plate with peeling sheet>

On the release agent layer of the release sheet, the adhesive material solution was formed to have a film thickness of 25 μm after drying and coated with an applicator, and then dried at 90 ° C for one minute to form an adhesive material layer. In addition, the adhesive material solution is a mass ratio of 100 parts of acryl alkyne, and tris(acryloyloxyethyl)isocyanuric acid (manufactured by Toagosei Co., Ltd., product name). M-315") 15 mass parts, photo-coincidence starter (manufactured by CIBA SPECIALTY CHEMICALS, product name " 500") 1.5 mass part, polyisocyanate bridging agent (made by Japan POLYURETHANE company, trade name " L") The mass portion and the decane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed with 0.1 mass portions, and then a toluene was added as a solvent to adjust the solid content to a solution of 20% by mass. Next, a polarizing plate composed of a polarizing film with a disk-shaped liquid crystal layer is attached to the release sheet so that the adhesive material layer and the disk-shaped liquid crystal layer are in close contact with each other. At this time, the linear axis set in the width direction when the biaxially stretched PET film for the release sheet substrate is stretched is bonded to be parallel to the polarization axis of the polarizing plate. Thirty minutes after the lapse of the bonding, the ultraviolet ray (UV) was irradiated from the side of the release sheet substrate by the following conditions to harden the adhesive material to form an adhesive layer, and a polarizing plate with a release sheet was obtained. In the polarizing plate to which the release sheet is attached, the thickness of the adhesive layer is 25 μm. Further, the storage elastic modulus (G') at 23 ° C of the adhesive layer was 0.94 MPa.

<UV irradiation conditions>

FUSION company's electrodeless lamp uses H valve plug

Illuminance: 600mW/cm ² , light quantity 150mJ/cm ²

UV illumination. The light meter is "UVPF-36" manufactured by ARGO GRAPHICS.

[Comparative Example 1]

In addition to the use of a ruthenium resin solution (manufactured by DOW CORNING Co., Ltd., trade name "BY-24-561") containing an organic polyfluorene having a vinyl group and an organic polyoxyloxy group having a hydroxyl group, the oxime resin solution is used. A release sheet and a polarizing plate with a release sheet were produced in the same manner as in Example 1.

[Comparative Example 2]

A release sheet and a polarizing plate with a release sheet were produced in the same manner as in Example 1 except that the heat drying temperature at the time of curing the additional reaction type oxime resin composition was 120 °C.

The release sheets of the respective examples and comparative examples were evaluated by the following methods.

(1) Residual adhesion rate

Adhesive tape (manufactured by Nitto Denko Corporation, product name "polyester resin adhesive tape 31B") having a width of 20 mm and a length of 20 cm was bonded to the surface of the release sheet layer of the peeling sheet obtained in each of the examples and the comparative examples. A load of 9.81 x 10 ^-3 N/mm ² was applied thereto and placed at 70 ° C for 24 hours. Thereafter, the sheet was allowed to stand under a condition of a humidity of 65% at 23 ° C for 24 hours, and then the adhesive tape was peeled off from the release sheet and attached to a stainless steel plate. At the same time, the adhesive tape was peeled off from the stainless steel plate at an angle of 180° at a speed of 300 mm/min to measure the adhesion force (A). Moreover, the adhesive tape which was not bonded to the peeling sheet was adhered to the stainless steel plate as white, and the adhesive force (B) was measured in the same manner. The residual adhesion ratio was set to 100x (A/B) and evaluated by the following evaluation criteria.

O: The residual adhesion ratio was 90% or more, and the residual adhesion ratio was good.

△: The residual adhesion ratio is 80% or more and less than 90%, and can be used.

X: The residual adhesion rate is less than 80% and cannot be used.

(2) substrate shrinkage

In each of the examples and comparative examples, the release sheet before and after the formation of the release agent layer was measured. The length of the substrate in the width direction was calculated using the following calculation formula to calculate the shrinkage ratio of the release sheet substrate.

The substrate shrinkage ratio (%) = 100 - (the length in the width direction of the release sheet substrate after the release agent layer is formed / the length in the width direction of the release sheet substrate before the release agent layer is formed) x 100.

(3) Alignment angle

In each of the examples and the comparative examples, the alignment main axis of the release sheet base material before and after the formation of the release agent layer was inclined by a few degrees with respect to the linear axis set in the width direction of the release sheet base material, and was made by a lightness meter (manufactured by Otsuka Electronics Co., Ltd., The product name "RETS R&D" is measured. This measurement is performed using ten points equally from the end in the width direction to the end to calculate the maximum value, the minimum value, and the distribution range (difference between the maximum value and the minimum value) of the alignment angle.

(4) Peel force

In each of the examples and the comparative examples, the obtained polarizing plate with a release sheet was subjected to a tensile tester using JIS-Z0237 as a reference to measure the peeling force of the release sheet. Specifically, the polarizing plate with the release sheet was cut into a width of 20 mm and a length of 200 mm, and the polarizing plate was fixed, and the peeling sheet was stretched in the 180° direction at a peeling speed of 300 mm/min to measure relative to The peeling force of the peeling sheet of the polarizing plate.

(5) Time-dependent changes in peel force

After the polarizing plate with the release sheet of each of the examples and the comparative examples was produced, the peeling force (F1) of the peeling sheet when it was left for seven days under the condition of a temperature of 23 ° C and a humidity of 50% was measured by the method of the above (4). . In the same manner, the peeling force (F2) of the peeling sheet placed 30 days after the production was measured under the conditions of a temperature of 23 ° C and a humidity of 50%, and the peeling force change rate (F2/F1) was calculated by the following criteria for evaluation. .

O: 0.6 ≦ F2 / F1 ≦ 1.4.

△: 0.5 ≦ F2 / F1 < 0.6 or 1.4 < F2 / F1 ≦ 1.5.

X: Outside the range of 0.5 ≦ F2 / F1 ≦ 1.5.

(6) Disadvantage checkability

In each of the examples and comparative examples, the obtained polarizing film with a release sheet was obtained. The plate was subjected to a polarizing plate for overlap inspection and visually observed by a crossed polarizing method to confirm the defect inspectability. At this time, the polarization axis of the polarizing plate for inspection was made perpendicular to the polarization axis of the polarizing plate with the release sheet, and a release sheet was disposed between the two polarizing plates. Those who have no light interference, can be visually inspected as O, and those who have light interference and cannot be visually inspected are referred to as X.

As described above, in the first embodiment, the curing temperature of the release agent is set to a lower temperature (100 ° C), and by suppressing heat shrinkage of the release sheet substrate, the release agent layer can be maintained even after the release agent layer is formed. The distribution range of the alignment angle before formation is formed, and the defect checkability can be made good. On the other hand, in the use of higher temperatures (120 In Comparative Example 2 in which the hardened release agent layer was cured, the release sheet substrate was thermally shrunk, and the distribution range of the alignment angle before the formation of the release agent layer could not be maintained, and the defect checkability could not be improved.

Further, in the examples, since the organic polyfluorene having a hexyl group on the release agent composition and the MQ resin having an alkenyl group are used, the residual adhesion rate and the peeling force can be obtained even if the curing temperature is lowered to a low temperature. Any change over time is excellent. On the other hand, in Comparative Example 1 using an organopolyfluorene having an ethyl group on the release agent composition, when the curing temperature was lowered to a low temperature, the residual agent composition was not sufficiently hardened, so the residual adhesion ratio was The lowering of the peeling force also becomes larger with time, and it is not possible to provide a peeling sheet having good peeling properties. Further, in Comparative Example 2 in which Example 1 and the release agent composition were used in the same manner, by changing the curing temperature, the change in peeling force with time was also large, and it was not possible to provide a release sheet having good peeling performance.

Claims (6)

A release sheet comprising a release agent layer on one side of a release sheet substrate, wherein the release sheet substrate is a uniaxial or biaxially stretched polyester film; and the release agent layer is an additional reaction type resin The composition is formed by curing a film, and the additional reaction type oxime resin composition comprises an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms in the molecule, and an MQ resin having an alkenyl group in the molecule; And in the peeling sheet base material provided with the release agent layer, the inclination (alignment angle) of the alignment main axis of the release sheet base material facing the linear axis set in an arbitrary direction is 5° or less. In the case where the linear axis is set to the longitudinal direction or the width direction when the polyester film is stretched, the maximum value of the inclination (alignment angle) of the alignment main axis of the release sheet base material is 5 or less. The release sheet of claim 1, wherein the MQ resin has SiO ₂ units, (CH ₃ ) ₃ SiO _1/2 units, and CH ₂ =CH(CH ₂ ) _Z (CH ₃ ) ₂ SiO _1/ An anthracene resin having a structure of ₂ units (wherein, z represents an integer of 0 to 4). A polarizing plate with a release sheet is provided in the order of a polarizing plate, an adhesive layer, and a release sheet, wherein the release sheet is formed by providing a release agent layer on one surface of the release sheet substrate, and The release agent layer is temporarily fixed to the adhesive layer in a peelable manner; the release sheet substrate is a uniaxial or biaxially stretched polyester film; and the release agent layer is used to harden an additional reaction type resin composition. In the film formed by the film, the additional reaction type oxime resin composition includes an organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms in the molecule, and an MQ resin having an alkenyl group in the molecule; In the release sheet base material of the release agent layer, the distribution of the inclination (alignment angle) of the alignment main axis of the release sheet base material facing the linear axis set in an arbitrary direction is 5° or less, and When the linear axis is set to the longitudinal direction or the width direction when the polyester film is extended, the release sheet The maximum value of the inclination (alignment angle) of the alignment main axis of the substrate is 5 or less. A polarizing plate with a release sheet according to the third aspect of the invention, wherein the pressure-sensitive adhesive layer is formed of an adhesive having a storage modulus (G') at 23 ° C of 0.3 MPa or more. A non-substrate double-sided adhesive sheet is formed by laminating a light release sheet and a heavy release sheet on both sides of an adhesive layer, wherein the release sheet is formed by providing a release agent layer on one side of the release sheet substrate. And the release agent layer is temporarily fixed to the adhesive layer in a peelable manner; the peeling force against the adhesive layer of the light release sheet is greater than the peeling force of the adhesive layer of the heavy release sheet The release sheet substrate is a uniaxial or biaxially stretched polyester film; the release agent layer is formed by curing a film of an additional reaction type bismuth resin composition, and the additional reaction type ruthenium resin composition is contained in the molecule An organic polyfluorene having an alkenyl group having 6 to 10 carbon atoms; and an MQ resin having an alkenyl group in a molecule; and the release sheet substrate provided with the release agent layer, and in any direction The distribution range of the inclination (alignment angle) of the alignment main axis of the release sheet base material with respect to the set linear axis is 5° or less, and the linear axis is set to the longitudinal direction or width when the polyester film is extended. In case, the maximum value of the base sheet with the release of the inclined spindle (alignment angle) is 5 ° or less. The non-substrate double-sided adhesive sheet according to claim 5, wherein the adhesive layer is formed of an adhesive having a storage modulus (G') at 23 ° C of 0.3 MPa or more.