TW201432012A - Substrate-less double-sided adhesive sheet - Google Patents

Abstract

A substrate-less double-sided adhesive sheet (10) in which release films (31, 32) are laminated on each side of an adhesive layer (11) and the peel force of one release film (first release film) (31) is smaller than the peel force of the other release film (second release film) (32), wherein the second release film (32) simultaneously satisfies the following conditions (a) to (c). (a) A release film in which a release layer (25) is provided on a surface of a coating layer (24) which comprises a hydrolytic silicon compound provided on a biaxially oriented polyester film. (b) Variation in the angle of orientation in the film surface of the biaxially oriented polyester film is 6 degrees/500 mm or less. (c) The amount of oligomer extracted from the surface of the release layer (25) of the release film (32) by dimethylformamide is 0.5 mg/m2 or less.

Description

Non-substrate two-sided adhesive sheet

The present invention relates to a non-substrate double-sided adhesive sheet, which is excellent in antistatic property, mold release property, oligomer sealing property, and ease of inspection, and does not cause peeling static electricity when the release film is peeled off, and can be peeled off with good peelability. Further, it is characterized in that after the adhesive is applied and after the release film is attached, the peeling variation on the adhesive layer is small, and the movement of the oligomer on the adhesive layer is carried out. Precipitate as little as possible. For example, in the production of a liquid crystal polarizing plate, a capacitive touch panel, or the like, a suitable substrate-free double-sided adhesive sheet is provided for various applications in which an adhesive layer is bonded.

Conventionally, various adhesive sheets which are placed between the objects are known, and as one of the adhesive sheets, it is known whether or not the substrate is adhered on both sides. The non-substrate two-sided adhesive sheet is formed by laminating a lightly peeling film having a relatively low peeling force on both sides of the adhesive layer and a laminate having a relatively high peeling force, and removing the peeling film on both sides, and then forming only There are two-sided adhesive sheets that do not have an adhesive layer supporting the substrate.

As a method of using the substrate-free double-sided adhesive sheet, for example, the light release film is first peeled off, and then on one side of the exposed adhesive layer. After the object surface of the other surface to which the surface is bonded, the heavy peeling film is further peeled off, and the other side of the exposed adhesive layer is followed by a different object surface, thereby processing the surface between the objects. step.

In recent years, there has been no adhesive substrate on both sides of the substrate, and attention has been paid to the viewpoint of good workability, and the use has been gradually increased, and it has also been used for various optical applications such as mobile phones. In particular, the capacitive touch panel has a rapidly expanding use as a information terminal by a multi-touch operation using two fingers for screen operations. In the capacitive touch panel, the thickness of the touch panel tends to be thicker than that of the resistive film method. Therefore, it has been proposed to increase the thickness of the adhesive layer to eliminate the difference in printing. When the pressure-sensitive adhesive layer is thickened, when the release film is peeled off, there is a problem that the adhesive layer is adhered to the release film or the air bubbles are mixed in the adhesive layer transferred to the release film. The situation. Therefore, when the non-substrate double-sided adhesive sheet is used for optical use, it is not only that there is no adhesive sheet on both sides of the substrate, and the release film to be combined also has a mold release film which is more strict and higher in quality than the conventional one.

On the other hand, when the release film is used, there is a case where the static electricity is peeled off when the adhesive layer is peeled off, and as a result, there is a possibility of occurrence of product defects or the like due to adhesion or entrapment of foreign matter or the like at the processing site. The situation of bad conditions.

Therefore, the antistatic countermeasures performed only in accordance with the equipment in the manufacturing step are not necessarily sufficient, and the antistatic treatment from the release film itself is strongly desired. Further, in the release film in which the release layer of the heavy release type is provided, it is peeled off after being adhered to the adhesive layer for a long period of time. The tendency to peel off when heavy. When the release film is bonded to the release film via the adhesive layer as in the case of the present invention, when the ratio of the peeling force deviates from the desired range, if it is necessary to peel off, there is a problem that the peeling is difficult.

Further, in the state in which the pressure-sensitive adhesive layer is provided on the second release film (the heavy release side), it is bonded to the counterpart member, and the inspection with the optical evaluation is performed. At this time, when the inspection is performed by the optical member having a polarizing effect, the inspection visual field may be dark due to the angle.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application No. 2010-56884

[Patent Document 2] Japanese Patent Application No. 2010-121101

[Patent Document 3] Japanese Patent Application No. 2010-97765

[Patent Document 4] Japanese Patent Application No. 2010-97925

[Patent Document 5] Japanese Patent Application No. 2010-165733

[Patent Document 6] Japanese Patent Application No. 2011-48410

[Patent Document 7] Japanese Patent Application No. 2011-75120

The present invention has been made in view of the above circumstances, and provides a substrate-free double-sided adhesive sheet which is attached to an adhesive layer. A non-substrate two-sided adhesive sheet on which a release film is laminated on both sides, which is suitable for use as a member for a touch panel such as a capacitive method, and has excellent antistatic property, mold release property, oligomer sealing property, and easy inspection property. And the release film itself has oligomer sealing properties.

In view of the above-described actual conditions, the inventors of the present invention have found that the above problems can be easily solved by the substrate-free double-sided adhesive sheet formed by a specific configuration, and the present invention has been completed. The present invention consists of two related inventions, and the gist of each invention is as follows.

That is, the first aspect of the invention is a substrate-free double-sided adhesive sheet characterized in that a release film is laminated on both surfaces of an adhesive layer, and one release film (first release film) is used. In the substrate-free double-sided adhesive sheet having a peeling force smaller than that of the other release film (second release film), the second release film satisfies the conditions (a) to (c) described below. , (a) A release film provided with a release layer on the surface of a coating layer containing a hydrolyzable ruthenium compound provided on a biaxially stretched polyester film.

(b) The variation of the alignment angle in the plane of the biaxially stretched polyester film film is 6 degrees/500 mm or less.

(c) The amount of the oligomer extracted from the surface of the release layer of the release film by dimethylformamide is 0.5 mg/m ² or less.

Further, according to a second aspect of the invention, there is provided a substrate-free double-sided adhesive sheet, characterized in that the substrate having the first object is adhesively bonded on both sides. In the sheet, the film haze of the first release film was 6% or more.

The first invention is excellent in antistatic property and mold release property and has oligomer sealing performance. Therefore, it is suitable as a substrateless double-sided adhesive sheet for use in, for example, a capacitive touch panel, and has high industrial value. According to the second aspect of the invention, the easiness of inspection and the visibility are further improved.

10‧‧‧No substrate double-sided adhesive sheet

11‧‧‧Adhesive layer

13‧‧‧1st release film substrate

14‧‧‧1st coating layer

15‧‧‧1st release agent layer

23‧‧‧Second release film substrate

24‧‧‧2nd coating layer

25‧‧‧Second release agent layer

31‧‧‧1st release film (light release sheet)

32‧‧‧Second release film (heavy release sheet)

Fig. 1 is a schematic cross-sectional view showing a substrate-free double-sided adhesive sheet according to an embodiment of the present invention.

<First invention>

In the present invention, the polyester film constituting the first and second release films may have a single layer structure or a laminate structure, and may be composed of, for example, two or three layers, and that the present invention does not exceed the gist of the present invention. The multilayer of 4 or more layers is not particularly limited.

The polyester used in the polyester film in the present invention may be a homopolymer polyester or a copolymerized polyester. When it consists of a homopolyester, it is preferable to obtain the polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalene dicarboxylic acid, and examples of the aliphatic diol include aliphatic diols. Ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and the like. As a representative polyester, polyethylene terephthalate (PET) or the like can be exemplified. On the other hand, examples of the dicarboxylic acid component of the copolymerized polyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and hydroxycarboxylate. One or more of an acid (for example, p-hydroxybenzoic acid, etc.), and examples of the diol component include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, 1,4-cyclohexanedimethanol, and neopentyl One or more of alcohols and the like. In any case, the term "polyester" as used in the present invention means a polyester such as polyethylene terephthalate having an ethylene terephthalate unit of usually 60 mol% or more, preferably 80 mol% or more. .

In the present invention, it is preferred to blend particles in the polyester layer for the main purpose of imparting slipperiness. The type of the particles to be blended is not particularly limited as long as it imparts slipperiness, and specific examples thereof include cerium oxide, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, and kaolin. Particles such as alumina and titania. In addition, the heat-resistant organic particles described in Japanese Patent Publication No. 59-217755, and the like. Examples of the other heat-resistant organic particles include a thermosetting urea resin, a thermosetting phenol resin, a thermosetting epoxy resin, and a benzoguanamine resin. Further, in the polyester production step, precipitated particles in which a part of the metal compound such as a catalyst is precipitated or finely dispersed may be used.

On the other hand, the shape of the particles to be used is not particularly limited, and a spherical shape, a block shape, a rod shape, a flat shape, or the like can be used. also. There are no special restrictions on the hardness, specific gravity, color, and the like. The series of grains It is also possible to combine two or more types as needed.

Further, the average particle diameter of the particles to be used is usually in the range of 0.01 to 3 μm, preferably 0.01 to 1 μm. When the average particle diameter is less than 0.01 μm, the particles tend to aggregate, and the dispersibility may be insufficient. When the thickness exceeds 3 μm, the surface roughness of the film becomes too thick, which may cause a problem such as when the release layer is applied in the subsequent step.

Further, the content of the particles in the polyester layer is usually in the range of 0.001 to 5% by weight, preferably 0.005 to 3% by weight. When the content of the particles is less than 0.001% by weight, the slipperiness of the film may be insufficient. On the other hand, when the amount is more than 5% by weight, the transparency of the film may be insufficient.

The method of adding the particles to the polyester layer is not particularly limited, and a conventionally known method can be employed. For example, it may be added at any stage of producing the polyester constituting each layer, but it is preferred to carry out the polycondensation reaction at the stage of esterification or after completion of the transesterification reaction.

Further, the dried particles are obtained by blending a slurry of particles dispersed in ethylene glycol or water with a polyester raw material by using a kneading extruder equipped with a vent hole, or by using a kneading extruder. It is carried out by a method of blending with a polyester raw material or the like.

Further, in the polyester film of the present invention, in addition to the above particles, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments and the like may be added as needed.

The thickness of the polyester film constituting the first release film and the second release film of the present invention is not limited as long as it can be used as a film. It is specifically limited, but it is usually in the range of 25 to 250 μm, preferably 38 to 188 μm, and more preferably 50 to 125 μm.

Next, a production example of the polyester film of the present invention will be specifically described, but it is not limited to the following production examples.

Preferably, the melted sheet extruded from the die is first solidified by a cooling roll using a polyester raw material as described above to obtain an unstretched sheet. At this time, in order to improve the planarity of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling cylinder, and it is preferable to use an electrostatic application sealing method and/or a liquid coating sealing method. The resulting unstretched sheet is then extended in the biaxial direction. At this time, the aforementioned unstretched sheet is first extended in a roll or tenter type stretching machine in one direction. The stretching temperature is usually 70 to 120 ° C, preferably 80 to 110 ° C, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, the extension temperature orthogonal to the extending direction of the first stage is usually 70 to 170 ° C, and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Then, heat treatment is continued under tension of 180 to 270 ° C or relaxation within 30% to obtain a biaxial alignment film. In the above extension, a method of extending in one direction in two or more stages may be employed. In this case, it is preferred to finally perform the method in which the stretching ratios in the two directions are each in the above range.

Further, in the production of the polyester film of the present invention, a simultaneous biaxial stretching method can also be employed. At the same time, the biaxial stretching method is a method in which the unstretched sheet is controlled to a temperature of 70 to 120 ° C, preferably 80 to 110 ° C, and is extended toward the machine direction and the width direction, and the stretching ratio is increased by the area magnification. Calculated as 4 to 50 times, preferably 7 to 35 times, more preferably 10 ~25 times. Then, heat treatment is continued under tension at a temperature of 170 to 250 ° C or under a relaxation of 30% to obtain an extended alignment film. Regarding the simultaneous biaxial stretching device using the above extension method, a conventionally known extension method such as a screw method, a scale drawing method, or a linear driving method can be employed.

Further, in the step of extending the above-mentioned polyester film, a so-called coating stretching method (in-line coating) for treating the surface of the film can be applied. When the coating layer is provided on the polyester film by the coating stretching method, the coating can be carried out simultaneously with the stretching, and the thickness of the coating layer can be made thinner according to the stretching ratio, and a film suitable as a polyester film can be produced.

The coating layer constituting the release film of the present invention will be described.

The coating layer constituting the release film of the present invention is excellent in antistatic property and oligomer deposition preventing property, and is excellent in adhesion between the release film and the polyester film over time. It is essential to contain a hydrolyzable hydrazine compound.

The hydrolyzable hydrazine compound used in the present invention is preferably represented by the general formula Si(OR ¹ )x(R ² ) _4-x for the use of the present invention. In the above general formula, x is preferably an integer of 2 to 4. In the above general formula, R ^{1 is} preferably either an alkyl group or a fluorenyl group. The alkyl group may, for example, be a methyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group or a tert-butyl group; Ethyl group and other carbon groups of 1 to 4 carbon atoms. In the above general formula, R ² is an organic group having 1 to 10 carbon atoms, for example, an unsubstituted or substituted hydrocarbon group. The unsubstituted hydrocarbon group may, for example, be methyl, ethyl, n-propyl, i-propyl, n-butyl, tert-butyl, n-hexyl, cyclohexyl, n-octyl, tert-octyl, n. An alkyl group such as a fluorenyl group; an aryl group such as a phenyl group; an alkenyl group such as a vinyl group or an allyl group; Further, examples of the substituted hydrocarbon group include γ-glycidoxypropyl group, γ-mercaptopropyl group, 3,4-epoxycyclohexylethyl group, and γ-methylpropenyloxypropyl group. These hydrolyzable hydrazine compounds may be used singly or in combination of two or more kinds.

Specific examples of the hydrolyzable hydrazine compound of x = 4 include tetramethoxy decane, tetraethoxy decane, tetra-n-propoxy decane, tetra-n-butoxy decane, and tetra-ethoxycarbonyl. Decane and so on. Specific examples of x = 3 include methyl trimethoxy decane, methyl triethoxy decane, ethyl trimethoxy decane, ethyl triethoxy decane, n-propyl trimethoxy decane, and n- Propyltriethoxydecane, i-propyltrimethoxydecane, i-propyltriethoxydecane, γ-chloropropyltrimethoxydecane, γ-chloropropyltriethoxydecane, γ- Glycidoxypropyltrimethoxydecane, γ-glycidoxypropyltriethoxydecane, γ-methylpropenyloxypropyltrimethoxydecane, γ-mercaptopropyltriethoxy Baseline, phenyltrimethoxydecane, vinyltriethoxydecane, 3,4-epoxycyclohexylethyltrimethoxydecane, 3,4-epoxycyclohexylethyltriethoxydecane Wait. The alkoxydecane compound of x=2 may, for example, be dimethyldimethoxydecane, dimethyldiethoxydecane, methylphenyldimethoxydecane, diethyldimethoxydecane, or the like. Ethyldiethoxydecane, di-n-propyldimethoxydecane, di-n-propyldiethoxydecane, di-i-propyldimethoxydecane, di-i-propyl Diethoxydecane, diphenyldimethoxydecane, divinyldiethoxydecane, and the like.

Further, as a material constituting the coating layer of the present invention, in order to further improve the sealing property of the oligomer, it is preferred to use a metal in combination. Organic compound of the element.

Specifically, it is preferable that the coating layer contains at least one organic compound containing at least one metal selected from the group consisting of aluminum, titanium, and zirconium.

Specific examples of the organic compound having an aluminum element include exemplified (ethyl acetoacetate) aluminum, acetoacetate bis(ethyl acetonitrile) aluminum, and di-n-butoxy-monoethyl acetoacetic acid. Aluminum, di-iso-propoxylated-monomethylacetic acid aluminum acetate, and the like.

Specific examples of the organic compound having a titanium element include, for example, tetra-n-butyl titanate, tetraisopropyl titanate, butyl titanate dimer, tetrakis(2-ethylhexyl) titanate, and titanic acid. Titanium orthoesters such as tetramethyl ester; titanium acetate pyruvate, titanium tetraacetate pyruvate, titanium polyacetylate pyruvate, titanium octyl glycol ester, titanium lactate, titanium triethanolamine, titanium ethyl acetoacetate Such as titanium chelate and the like.

Specific examples of the organic compound having a zirconium element include zirconium acetate, zirconium n-propionate, zirconium n-butyrate, zirconium tetraethatepyruvate, zirconium monoacetate pyruvate, and zirconium acedate pyruvate.

Among them, in particular, from the viewpoint of good oligomer deposition preventing performance, an organic compound containing a metal element selected from aluminum or zirconium, and an organic compound having a chelate structure are more preferable. In addition, the "Crosslinking Handbook" (Shanxia Jinsan, Jin Dongzhu Editor (share) Dacheng Society, Heisei 2nd Edition) also has specific records.

In the coating layer constituting the release film of the present invention, it is preferred to use a hydrolyzable hydrazine compound (A) in order to improve the sealing property of the oligomer. It is preferred to mix with the organic compound (B) containing a metal element. The blending ratio (weight ratio) of the two is preferably in the range of (A): (B) = 1:0.001 to 1:0.01. When it deviates from this range, the surface specific resistance (R) of the surface of the mold release layer in the release film may not reach a desired level, or the sealing property of an oligomer may be inadequate.

Next, the formation of the release layer in the present invention will be described.

The release layer constituting the first release film and the second release film in the present invention means a release layer, specifically, a release force by an acrylic adhesive tape and a release layer (F The invention can be completed within a certain range.

The peeling force of the first release film 31 corresponding to the light release side to the adhesive layer 11 is preferably 5 to 40 mN/cm. When the peeling force of the first release film is less than 5 mN/cm, the release film may be easily peeled off if it is not required to be peeled off. Further, when the peeling force of the first release film exceeds 40 mN/cm, a step of peeling off the first release film may cause a peeling phenomenon called floating between the second release film and the adhesive layer.

When the absolute value of the peeling force of the first release film 31 is suppressed to a low level, even if the absolute value of the peeling force of the second release film 32 is made low, the peeling force of the two release films 31 and 32 can be made poor. Become bigger. In addition, when the peeling force of the first release film 31 is equal to or greater than a predetermined value, it is possible to prevent the first release film 31 from being easily peeled off from the adhesive layer 11 or the first one before the use. The release film 31 is lifted by the adhesive layer 11.

On the other hand, the second release film corresponding to the heavy peeling side The peeling force of 32 is preferably 45 to 100 mN/cm, more preferably 50 to 80 mN/cm. When the peeling force of the second release film is less than 45 mN/cm, when the first release film is peeled off, a problem such as partial peeling of the second release film may occur. In addition, when the peeling force of the second release film exceeds 100 mN/cm, there may be a problem that the second release film remains from the component of the adhesive layer.

In the substrateless double-sided adhesive sheet of the present invention, in addition to the above-described peeling force adjustment, it is preferable to provide a difference in peeling force between the first release film and the second release film.

The peeling force of the second release film 32 is preferably 2.0 times or more, preferably 3.0 times or more, the peeling force of the first release film 31. When the peeling force of the second release film 32 is less than 2.0 times the peeling force of the first release film 31, when the first release film 31 on the light release side is peeled off, the second release film 32 is adhered. The adhesive layer component of the phenomenon in which the agent layer 11 floats may cause a problem that the second release film 32 remains or the peeling tearing sound or the like occurs.

The release layer constituting the first release film of the present invention may be provided on the polyester film by the above-described coating stretching method (in-line coating). The coating stretching method (in-line coating) is not limited to the following, but for example, in the sequential biaxial stretching, the coating treatment can be applied particularly before the end of the extension of the first stage and the extension of the second stage. When the release layer is provided on the polyester film by the coating stretching method, it can be applied simultaneously with the stretching, and the thickness of the release layer can be made thinner in accordance with the stretching ratio, whereby a film suitable as a polyester film can be produced.

Moreover, in order to make mold release property favorable in the mold release layer which comprises the release film of this invention, it is preferable to contain the hardening type poly It may be a type containing a hardening type polyoxymethylene resin as a main component, and grafting with an organic resin such as a urethane resin, an epoxy resin or an alkyd resin may be used without departing from the scope of the present invention. Denatured polyoxane type obtained by polymerization or the like.

The type of hardened polyoxyl resin is added. Condensed type. UV curing type. Electron beam hardening type. Solvent-free type, etc., any type of hardening reaction can be used. Specific examples include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, and X-62 manufactured by Shin-Etsu Chemical Co., Ltd. -1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A/B, X-62-7052, X-62-7028A/B , X-62-7619, X-62-7213, YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430 by Momentive Performance Materials , TPR6600, TPR6604, TPR6605, Toray. Dow Corning's SRX357, SRX211, SD7220, SD7292, LTC750A, LTC760A, LTC303E, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210 Wait. Further, a peeling control agent may be used in combination in order to adjust the peeling property of the release layer or the like.

In the present invention, the curing conditions in forming the release layer on the polyester film are not particularly limited, and when the release layer is provided by off-line coating, it is usually 120 to 200 ° C for 3 to 40 seconds. Heat treatment is carried out at 100 to 180 ° C for 3 to 40 seconds. Further, active energy ray irradiation such as heat treatment or ultraviolet irradiation may be used as needed. Further, as an energy source for hardening the active energy ray irradiation, a conventionally known device or energy source can be used. The coating amount of the release layer (after drying) is usually 0.005 to 1 g/m ² , preferably 0.005 to 0.5 g/m ² , more preferably 0.01 to 0.2 g/m ² in terms of coating properties. range. When the amount of application (after drying) is less than 0.005 g/m ² , there is a lack of stability in terms of coating properties, and it may be difficult to obtain a uniform coating film. On the other hand, when it is thicker than 1 g/m ² , the coating film adhesion and the hardenability of the release layer itself may be lowered.

In the second release film of the present invention, it is necessary that the variation of the alignment angle in the film is 6 degrees/500 mm or less. When the variation of the alignment angle exceeds 6 degrees / 500 mm, it is not suitable for this purpose.

In the present invention, as a method of providing a release layer to a polyester film, conventionally known methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating can be used. Coating method. As for the coating method, there is a description in the 1979 issue of the "Coating Method" bookstore.

In the first release film and the second release film of the present invention, an adhesive layer, an antistatic layer, or an oligo may be provided on the film surface on which the release layer is not provided, without impairing the gist of the present invention. A coating layer of a polymer precipitation preventing layer or the like.

Further, the surface of the polyester film constituting the first release film and the second release film may be subjected to corona treatment or plasma treatment in advance. Reason.

In the present invention, when the release film is produced, the coating layer may be applied onto the polyester film, and after the film is rolled up at one end, the release layer may be further provided on the coating layer or may be coated on the polyester film. After the cloth coating layer is dried and dried, a release layer is continuously provided on the coating layer, and any method can be used in the present invention.

In the release film constituting the substrate-free adhesive sheet of the present invention, the surface specific resistance (R) value of the release surface is preferably 1 from the viewpoint of adhesion to foreign matter on the surface of the adhesive layer or peeling off from static electricity. ×10 ¹² (Ω) or less. The R value is preferably 1 × 10 ¹¹ (Ω) or less, more preferably 1 × 10 ¹⁰ (Ω) or less. When R is deviated from the above range, there is a case where a release film or the like is peeled off due to a problem that a foreign matter is caught.

Further, in the release film of the present invention, after the heat treatment (180 ° C, 10 minutes), the amount of the oligomer (OL) extracted from the surface of the release layer is preferably 0.5 mg/m ² or less. When the OL exceeds 0.5 mg/m ² , when the release surface of the release film is bonded to the pressure-sensitive adhesive layer, the oligomer is precipitated over time, and the inspection step with optical evaluation may result in inspection. Obstruction.

Next, the adhesive layer constituting the substrate-free double-sided adhesive sheet of the present invention will be described below. The adhesive layer of the present invention means a layer composed of a material having adhesiveness, and a conventionally known material can be used without departing from the gist of the present invention. As a specific example, the case of using an acrylic adhesive is demonstrated below.

In the present invention, an acrylic adhesive means that it contains C The olefinic acid monomer is an adhesive layer formed of an essential monomer component as an adhesive layer of a base polymer. The acrylic polymer preferably has an alkyl (meth)acrylate and/or an alkoxyalkyl (meth)acrylate having a linear or branched alkyl group as an essential monomer component (more preferably An acrylic polymer formed as a main monomer component. Further, the acrylic polymer is preferably an acrylic polymer formed of an alkyl (meth)acrylate and an alkoxyalkyl acrylate having a linear or branched alkyl group as an essential monomer component.

The pressure-sensitive adhesive layer of the present invention is preferably an acrylic pressure-sensitive adhesive layer formed of an alkyl (meth) acrylate having a linear or branched alkyl group and an alkoxyalkyl acrylate as an essential monomer component.

Further, the monomer component of the acrylic polymer forming the base polymer in the adhesive layer of the present invention may further contain a polar group-containing monomer, a polyfunctional monomer or other copolymerizable monomer as Copolymerization of monomer components. Further, the above "(meth)acrylic acid" means "acrylic acid" and/or "methacrylic acid", and the others are also the same. Further, although not particularly limited, the content of the acrylic polymer of the base polymer in the adhesive layer of the present invention is preferably 60% by weight or more based on the total weight (100% by weight) of the adhesive layer. Preferably, it is 80% by weight or more.

The monomer component of the above-mentioned acrylic polymer can be suitably used, and an alkyl (meth)acrylate having a linear or branched alkyl group (hereinafter also referred to simply as "alkyl (meth)acrylate)" can be suitably used. Specific examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. Isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, (methyl) Amyl acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ( Isooctyl methacrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate Ester, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecane (meth)acrylate The alkyl group of the ester, heptadecylate (meth) acrylate, octadecyl (meth) acrylate, pentadecyl (meth) acrylate, eicosyl (meth) acrylate, etc. is 1~ 20 (meth)acrylic acid alkyl ester and the like. Further, the alkyl (meth)acrylate may be used alone or in combination of two or more. Among them, an alkyl (meth)acrylate having an alkyl carbon number of 2 to 14 is preferred, and an alkyl (meth)acrylate having an alkyl carbon number of 2 to 10 is more preferred.

The polar group-containing monomer may, for example, be a carboxyl group-containing monomer such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid or isocrotonic acid or an anhydride thereof (maleic anhydride). Et.); 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, etc. a hydroxyalkyl acrylate; a hydroxyl (hydroxyl)-containing monomer such as vinyl alcohol or allyl alcohol; (meth) acrylamide, N,N-dimethyl(meth) acrylamide, N -Hydroxymethyl (meth) acrylamide, N-methoxy a mercapto group-containing monomer such as a (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-hydroxyethyl acrylamide or the like; an amine (meth) acrylate An amine group-containing monomer such as ester, dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, etc.; glycidyl (meth)acrylate, (methyl) a monomer containing a glycidyl group such as methyl epoxidized propyl acrylate; a cyano group-containing monomer such as acrylonitrile or methacrylonitrile; N-vinyl-2-pyrrolidone, (methyl) Propylene decylmorpholine, in addition to N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-ethylene a heterocyclic-containing vinyl monomer such as oxazole; a sulfonic acid group-containing monomer such as sodium vinyl sulfonate; a phosphate group-containing monomer such as 2-hydroxyethyl propylene decyl phosphate; A monomer containing an oxime imine group such as hexamethylene imine or isopropyl maleimide; an isocyanate group-containing monomer such as 2-methylpropenyloxyethyl isocyanate or the like. The above polar group-containing monomers may be used singly or in combination of two or more.

Examples of the polyfunctional monomer include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, and (poly)propylene glycol. Di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trihydroxyl Methylpropane tri(meth)acrylate, tetramethylol methane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate , polyester acrylate, urethane acrylate, and the like. These polyfunctional monomers may be used alone or in combination of two or more.

The content of the polyfunctional monomer is preferably 0.5% by weight or less based on 100% by weight of the monomer component forming the acrylic polymer. When the content is more than 0.5% by weight, for example, the cohesive force of the adhesive layer may become too high and the stress relaxation property may be lowered.

Further, examples of the copolymerizable monomer (other copolymerizable monomer) other than the polar group-containing monomer or the polyfunctional monomer include cyclopentyl (meth)acrylate and cyclomethacrylate (meth)acrylate. a (meth) acrylate having an alicyclic hydrocarbon group such as an ester of an alicyclic hydrocarbon group or a (meth) acrylate having an aromatic hydrocarbon group such as an ester of an alicyclic hydrocarbon group such as isodecyl (meth)acrylate or the like. Ethylene (meth)acrylate, (meth)acrylic acid alkoxyalkyl ester or polar group-containing monomer or polyfunctional monomer (meth)acrylate; vinyl acetate, vinyl propionate, etc. An ester; an aromatic vinyl compound such as styrene or vinyl toluene; an olefin or a diene such as ethylene, butadiene, isoprene or isobutylene; or a vinyl ether such as a vinyl alkyl ether; Vinyl chloride and the like.

The acrylic polymer may be prepared by polymerizing the above monomer components by a conventionally known or conventional polymerization method. Examples of the polymerization method of the acrylic polymer include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or a polymerization method using active energy ray irradiation (active energy ray polymerization method). Among the above, a solution polymerization method and an active energy ray polymerization method are preferred from the viewpoints of transparency, water resistance, production cost, and the like.

Examples of the active energy rays to be irradiated during the active energy ray polymerization (photopolymerization) include an α line, a β line, a γ line, a neutron beam, and electricity. Ionizing radiation such as beamlets, or ultraviolet rays, etc., among which ultraviolet rays are particularly suitable for use in the present invention. Further, the irradiation energy of the active energy ray, the irradiation time, the irradiation method, and the like are not particularly limited as long as they do not impair the scope of the present invention.

Further, in the case of the above solution polymerization, various general solvents can be used. Examples of such a solvent include esters of ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; and cyclohexane. An organic solvent such as an alicyclic hydrocarbon such as methylcyclohexane or a ketone such as methyl ethyl ketone or methyl isobutyl ketone. The solvent may be used singly or in combination of two or more.

In the preparation of the above-mentioned acrylic polymer, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) may be used depending on the type of the polymerization reaction. The polymerization initiator may be used alone or in combination of two or more.

The photopolymerization initiator is not particularly limited, and a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-keto alcohol photopolymerization initiator, and an aromatic sulfonate can be used. Mercapto chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, diphenylethylenedione photopolymerization initiator, benzophenone photopolymerization A starter, a ketal photopolymerization initiator, a thioxanthone photopolymerization initiator, and the like. The amount of the photopolymerization initiator to be used is not particularly limited as long as it does not impair the scope of the present invention. For example, it is preferably 0.01 to 0.2 with respect to 100 parts by weight of the total monomer component of the acrylic polymer. The range of parts by weight.

Specific examples of the benzoin ether photopolymerization initiator include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin Butyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, anisole methyl ether and the like. The acetophenone-based photopolymerization initiator may, for example, be 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone or 1-hydroxycyclohexyl phenyl ketone. , 4-phenoxydichloroacetophenone, 4-(t-butyl)dichloroacetophenone, and the like. The α-keto alcohol-based photopolymerization initiator may, for example, be 2-methyl-2-hydroxypropionylbenzene or 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropane-1- Ketones, etc. Specific examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalenesulfonyl chloride. The photoactive oxime-based photopolymerization initiator may, for example, be 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-ruthenium or the like. The benzoin-based photopolymerization initiator includes, for example, benzoin or the like. The diphenylethylenedione photopolymerization initiator contains, for example, diphenylethylenedione or the like. Specific examples of the benzophenone-based photopolymerization initiator include benzophenone, benzamidine benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and polyethylene II. Benzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Specific examples of the ketal-based photopolymerization initiator include benzyldimethylketal and the like. Specific examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, and isopropylthioxan Ketone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

Specific examples of the above thermal polymerization initiator include an azo polymerization initiator [for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2 , 2'-azobis(2-methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, azobisisoprene, 2,2'-azo double (2-mercaptopropane) Dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis(2-A a bisulphate, a 2,2'-azobis(N,N'-dimethyleneisobutylphosphonium) dihydrochloride, etc., a peroxide-based polymerization initiator (for example, peroxidation) a dibenzyl sulfonyl group, a tert-butyl permaleate or the like), a redox polymerization initiator, and the like. The amount of the thermal polymerization initiator to be used is not particularly limited as long as it does not impair the scope of the gist of the present invention.

In the acrylic pressure-sensitive adhesive layer used as one of the adhesive layers in the present invention, a crosslinking agent, a crosslinking accelerator, and an adhesion-imparting agent may be used as needed within the range which does not impair the characteristics of the present invention (for example). Rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc.), anti-aging agent, filler, colorant (pigment or dye, etc.), ultraviolet absorber, antioxidant, chain transfer agent, plasticizer, A known additive such as a softener, a surfactant, an antistatic agent or the like. Further, when the adhesive layer is formed, various general solvents can be used. The type of the solvent is not particularly limited, and those which are used for the solution polymerization described above can be used.

The above crosslinking agent can control the gel fraction of the adhesive layer by crosslinking the base polymer of the adhesive layer. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, and a peroxide crosslinking agent, and examples thereof include a urea crosslinking agent and a metal alkoxide crosslinking agent. Metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent, oxazoline crosslinking agent, aziridine crosslinking agent, amine crosslinking agent, etc. An isocyanate crosslinking agent or an epoxy crosslinking agent is used. The crosslinking agent may be used alone or in combination of two or more.

Next, in the substrateless double-sided adhesive sheet of the present invention, when the acrylic adhesive composition is used in the formation of the adhesive layer, for example, an optical member (for example, a surface protective layer, a touch panel, and an image display unit) is used. The gap existing between the display surface and the like is replaced by a transparent adhesive sheet having a refractive index close to that of the optical member, thereby improving light transmittance, and in view of suppressing the luminance or contrast reduction of the image display device, the adhesive layer is preferably used. It is designed to be soft. For example, the storage modulus (G') in the dynamic viscoelasticity is preferably 1.0 × 10 ⁵ Pa or less, more preferably 5.0 × 10 ⁴ Pa or less. When the storage modulus (G') exceeds 1.0 × 10 ⁵ Pa, for example, when filling the gap existing between the optical members, the filled adhesive layer cannot reach every corner, and may be peeled off at the end or floated. The situation of the bad situation.

The thickness of the adhesive layer constituting the substrate-free double-sided adhesive sheet of the present invention is in the range of 25 μm to 200 μm, preferably 50 μm to 150 μm. When the thickness of the adhesive layer is 25 μm or less, for example, the voids generated between the optical members become excessively large, and it may be difficult to fill the adhesive layer to each corner. On the other hand, when the thickness of the adhesive layer exceeds 200 μm, the thickness of the adhesive layer becomes thicker than the gap formed between the optical members, and there is a possibility that the adhesive layer component which is excessive is excessively filled between the optical members. The situation.

<Second invention>

The present invention is different from the above-described first invention in that the film haze of the first release film is 6% or more as a constituent element from the viewpoint of facilitating external recognition. The film haze of the first release film is preferably It is 10% or more. When the film has a haze of less than 6%, the release film may be misaligned when it is peeled off from the non-substrate double-sided adhesive sheet.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples as long as they do not. Further, the measurement method used in the present invention is as follows.

(1) Determination of the inherent viscosity of polyester:

The fine scale was prepared by dissolving 100 g of a polyester solvent in which a polyester-incompatible polymer component and a pigment were removed, and adding 100 ml of a mixed solvent of phenol/tetrachloroethane = 50/50 (weight ratio), and measuring at 30 ° C. .

(2) Determination of average particle diameter (d ₅₀ : μm):

The value of 50% of the integral (weight basis) in the equivalent spherical distribution measured by a centrifugal sedimentation type particle size distribution measuring apparatus (Model SA-CP3 manufactured by Shimadzu Corporation) was used as the average particle diameter.

(3) Determination of film haze of the first release film:

The film haze (turbidity) was measured by a ball turbidity meter NDH-20D manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS-K6714.

(4) Determination of the change of the alignment angle in the main alignment axis and the film:

For the width direction of the polyester film constituting the second release film, As the center position, the sample was cut from the two ends at the ends of each 500mm position. The polarizing microscope made by Carl Zeiss was used to observe the alignment of the polyester film, and the main alignment axis in the surface of the polyester film was obtained. The direction is inclined by a few degrees with respect to the MD of the polyester film. Further, in the measurement, when the main alignment axis exceeds 90 degrees, the complementary angle is used as the angle of the main alignment axis with respect to the MD direction. Further, when the variation of the alignment angle including the position of the most end is calculated, when the position between the samples does not satisfy 500 mm, the variation of the alignment angle per 500 mm is calculated by the ratio calculation. In this way, the variation of the alignment angle per 500 mm in the width direction was obtained, and the average value was changed as the alignment angle in the width direction of the film.

(judgment basis)

A. . . The change of the alignment angle is 6 degrees/500 mm or less.

B. . . The change of the alignment angle exceeds 6 degrees / 500mm.

(5) Determination of in-plane retardation in the second release film:

In-plane hysteresis as a center position with respect to the film width direction was measured using a cellgap inspection apparatus RETS-1100A manufactured by Otsuka Electronics Co., Ltd. The in-plane retardation of the film was measured by an optical interference method using an aperture diameter of 5 mm at 23 °C.

(6) Determination of peeling force (F1.F2) of release film:

After attaching a single-sided adhesive tape ("No. 502" manufactured by Nitto Denko Corporation) to the surface of the release layer of the sample film, the cut was 50 mm × 300 mm. Inches, the peel force after standing at room temperature for 1 hour was measured. The peeling force was 180° peeling using a tensile tester ("Intesco model 2001" manufactured by Intesco) at a tensile speed of 300 mm/min.

(7) Determination of the surface specific resistance (R) of the release film:

The surface specific resistance (R) of the release surface was measured in the sample film, and the determination was made by the following criteria. The measurement conditions were carried out in an environment of 23 ° C and 50% RH. Will be Henghe. Hewlett-Packard company's inner electrode 50mm diameter, outer electrode 70mm diameter concentric electrode 16008A (trade name), set in a 23 ° C, 50% RH environment as a sample, apply a voltage of 100V, with the company's high resistance The surface specific resistance value of the sample was measured by measuring 4329A (trade name).

(judgment basis)

A. . . R (Ω) is 10 ¹² or less (a practical grade).

B. . . R (Ω) exceeds 10 ¹² (level of practical difficulty).

(8) Determination of the amount of oligomer (OL) extracted from the surface of the release layer of the release film:

The unheated release film was previously heated in air at 180 ° C for 10 minutes. Thereafter, the heat-treated film was adhered as much as possible to the inner surface of the box having an upper opening of 10 cm and a height of 3 cm, and was formed into a box shape. In the case where the coating layer is provided, the coating layer is made inside. Next, 4 ml of DMF (dimethylformamide) was added to the box prepared by the above method, and after standing for 3 minutes, DMF was recovered. The recovered DMF was supplied to liquid chromatography (manufactured by Shimadzu Corporation: LC-7A), and the amount of the oligomer in the DMF was determined, and the value was divided by the area of the film contacting the DMF as the amount of the surface surface oligomer (mg/m ^{2 ).} ).

The amount of oligomer in DMF is determined by the ratio of the peak area of the standard sample to the peak area of the peak area of the sample (absolute check curve method). The preparation of the standard sample is carried out by accurately weighing the previously-divided oligomer (cyclic trimer) and dissolving it in a properly weighed DMF. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg/ml.

Further, the conditions of the liquid chromatography are as follows.

Mobile phase A: acetonitrile

Mobile phase B: 2% aqueous acetic acid solution

Pipe column: MCI GEL ODS 1HU by Mitsubishi Chemical Corporation

Column temperature: 40 ° C

Flow rate: 1ml/min

Detection wavelength: 254nm

(9) Determination of the amount of metal elements on the side of the release surface of the release film:

In the surface of the sample sample on which the release layer is provided, a fluorescent X-ray measuring device ("Xijin Shimatsu Co., Ltd." type "XRF-1500") is used, and the FP (Fundamental Parameter Method) method is used. The amount of metal elements was measured under the measurement conditions shown in Table 1.

(10) Coating film adhesion promotion evaluation of release film (utility evaluation evaluation):

The sample film was placed in a constant temperature and humidity chamber at 60 ° C and 80% RH for 4 weeks, and then the sample film was taken out. Thereafter, the release surface of the sample film was rubbed by the tentacle for 5 times, and the degree of detachment of the release layer was determined by the following criteria.

(judgment basis)

A. . . No peeling of the film (a practical grade) is seen.

B. . . Although the coating film turns white, it does not fall off (a practical grade).

C. . . It was confirmed that the coating film was peeled off (level of practical difficulty).

(11) Determination of the storage modulus (G') of the adhesive layer:

The separator was peeled off from the double-sided adhesive sheet obtained in the examples and the comparative examples, and only the acrylic pressure-sensitive adhesive layer was laminated, and a laminate of an acrylic pressure-sensitive adhesive layer having a thickness (after drying) of 1.5 mm ± 0.1 mm was prepared as a measurement sample. The measurement sample was measured at a temperature rise rate of 5 ° C/min at a frequency of 1 Hz using an "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific Co., Ltd. to obtain a storage mold at a temperature of 23 ° C. Number (G`). Further, the storage modulus (G') of the adhesive layer used in the examples and comparative examples of the present invention was 5.0 × 10 ⁴ Pa.

(12) Evaluation of tearing soundness of peeling (utility evaluation of utility characteristics):

The following adhesive composition was applied to the second release film, and heat-treated at 100 ° C for 5 minutes to obtain an adhesive layer having a thickness (after drying) of 50 μm. Then, the first release film was bonded to the non-substrate double-sided adhesive sheet on the surface of the adhesive layer, and the peeling state was observed when the first release film was peeled off, and the occurrence of tearing of the peeling was as follows. The judgment criterion is determined.

<Acrylic adhesive composition> (monomer blending composition)

2-ethylhexyl acrylate 70% by weight

2-methoxyethyl acrylate 29% by weight

4-hydroxybutyl acrylate 1% by weight

To 100 parts by weight of the above monomer composition, CORONATE L and 0.1 part of CORONATE L manufactured by Japan Polyurethane were added to obtain a composition for forming an acrylic pressure-sensitive adhesive layer.

(judgment basis)

A: Very smoothly peeled off, no peeling streaks, and no peeling sound was produced.

B: A slight peeling streak was observed, and the peeling sound was extremely slight, or a slight peeling tear sound (a level which sometimes caused a problem in practical use).

C: The peeling streaks were visible, and a peeling sound was generated. A peeling tear (a level of practical problem) is produced.

(13) Evaluation of peelability of the first and second release films (utility evaluation evaluation):

In the item (7), when the first release film was peeled off, the state of the interface between the second release layer and the adhesive layer was evaluated by the following criteria.

(judgment basis)

A: No abnormality was observed at the interface between the second release layer and the adhesive layer (a practically problem-free grade).

B: At the interface between the second release layer and the adhesive layer, it is seen that it floats very little (a level that is sometimes a problem in practical use).

C: At the interface between the second release layer and the adhesive layer, a clear float (a practically problematic grade) can be seen.

(14) Assessment of the easiness of inspection (utility evaluation of utility characteristics):

Using the non-substrate double-sided adhesive sheet obtained in the examples and the comparative examples, the first release film was peeled off, and the exposed surface of the adhesive layer was bonded to the polarizing plate to obtain a polarizing plate/adhesive layer/second. A laminate formed by the formation of a release film.

Next, using the obtained laminate, the inspection of the polarizing plate was carried out by the crossed Nicols method.

The non-substrate two-sided adhesive sheets obtained in the examples have good inspection easiness, but in the non-substrate two-sided adhesive sheets obtained in the comparative examples, the change of the alignment angle exceeds 6 degrees/500 mm, and the cross nibs are bright and dark. It is not clear, it is difficult to check the situation.

(judgment basis)

A. . . The change of the alignment angle is 6 degrees/500 mm or less.

B. . . The change of the alignment angle exceeds 6 degrees / 500mm.

(15) Evaluation of oligomer sealing (utility evaluation of utility characteristics):

The amount of the oligomer obtained in the item (8) is determined by the following criteria.

(judgment basis)

A. . . The amount of the oligomer is 0.5 mg/m ² or less.

B. . . The amount of oligomer exceeds 0.5 mg/m ² .

(16) Cognitive assessment (utility feature surrogate assessment)

The substrate-free adhesive sheet was visually observed, and the release film on the side where the peeling force was light was attached to the side, and the judgment was made based on the following criteria.

(judgment basis)

A. . . Recognizable.

B. . . Identification is difficult.

(17) Antistatic property evaluation (utility evaluation of utility characteristics)

In the measurement environment of 23 ° C and 50% RH, the first release film was prepared by sufficiently adjusting the humidity of the non-substrate double-sided adhesive sheet. Thereafter, the exposed surface of the adhesive layer was slowly approached to the ash of the tobacco which was previously broken into fine powder, and the determination of the adhesion state of the ash at this time was performed by the following criteria.

(judgment basis)

A: Even if the film is brought into contact with ash, it does not adhere.

B: The film is only attached to the gray, that is, a large amount.

(18) Comprehensive assessment (utility characteristics surrogate assessment):

Evaluation items for the occurrence of peeling sound generation, peeling property, antistatic property, oligomer sealing property, adhesion, and ease of inspection using the substrate-free double-sided adhesive sheet produced in the examples and the comparative examples The comprehensive evaluation is carried out by the following criteria.

(judgment basis)

A: The tearing sound generation state, the peeling property, the antistatic property, the oligomer sealing property, the adhesion property, and the easiness of inspection are all "A" (a practically problem-free grade).

B: at least one of peeling sound generation state, peeling property, antistatic property, oligomer sealing property, adhesion property, and ease of inspection "B" (a level that sometimes causes problems in practice).

C: At least one of tearing sound generation state, peeling property, antistatic property, oligomer sealing property, adhesiveness, and ease of inspection is "C" (a practically problematic grade).

<First invention>

The polyesters used in the examples and comparative examples were prepared as follows.

<Manufacture of polyester> Production Example 1 (polyethylene terephthalate A1)

Take 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol and magnesium acetate. 4, 0.09 parts of water salt was placed in the reactor, and the temperature was raised while heating, and methanol was distilled off to carry out a transesterification reaction. Starting from the reaction, the temperature was raised to 230 ° C in 4 hours to substantially terminate the transesterification reaction. Next, 0.04 parts of ethylene glycol slurry ethyl acid phosphate and 0.03 parts of antimony trioxide were added, and the temperature was brought to 280 ° C in 100 minutes, and the pressure was 15 mmHg. Thereafter, the pressure was gradually reduced, and finally 0.3 mmHg. After 4 hours, the system was returned to normal pressure to obtain polyethylene terephthalate A1 having an intrinsic viscosity of 0.61.

Production Example 2 (polyethylene terephthalate A2)

In the same manner as in Production Example 1, except that 0.6 parts of cerium oxide particles having an average particle diameter of 2.5 μm were added, the polyethylene terephthalate A2 having an intrinsic viscosity of 0.62 was obtained.

Production Example 3 (Polyester Film F1a)

The raw material obtained by blending polyethylene terephthalate A1 and A2 in a ratio of 80% and 20%, respectively, is used as a surface layer raw material, and a raw material of polyethylene terephthalate A1=100% is used as an intermediate layer. The raw materials were supplied to two extruders equipped with vent holes, and supplied to an extruder equipped with a vent hole, and melt-extruded at 290 ° C, and then subjected to static electricity application to a cooling roll having a surface temperature of 40 ° C. The film was cooled and solidified to obtain an amorphous film having a thickness of about 1300 μm.

The film was stretched 3.5 times in the longitudinal direction at 90 ° C, and extended 4.1 times in the transverse direction at 130 ° C, and heat-treated at 230 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film F1a.

Production Example 4 (Polyester Film F2a)

The raw material obtained by blending polyethylene terephthalate A1 and A2 in a ratio of 80% and 20%, respectively, is used as a surface layer raw material, and a raw material of polyethylene terephthalate A1=100% is used as an intermediate layer. The raw materials were supplied to two extruders equipped with vent holes, melt-extruded at 290 ° C, and then cooled and solidified on a cooling roll having a surface temperature of 40 ° C by electrostatic application to obtain a thickness of about 740 μm. Shaped film.

The film was stretched 3.5 times in the longitudinal direction at 90 ° C, and extended 4.1 times in the transverse direction at 130 ° C, and heat-treated at 230 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film. Then, the coating layer composed of the coating agent composition described below was applied by reverse gravure coating so as to have a coating amount (after drying) of 0.05 g/m ² , and then applied at 120 ° C for 30 seconds. After heat treatment, a polyester film F2a having a coating layer having a thickness of 50 μm was obtained.

(coating layer composition)

AC1: Colcoat N-103X (manufactured by Colcoat)

AC2: ginseng (acetyl acetonate) aluminum

AC3: Tetraethylpyruvium pyruvate

AC4: titanium tetraacetate pyruvate

(mixing conditions)

AC1: 99.5 wt%

AC2: 0.5% by weight

AC3: 0% by weight

AC4: 0% by weight

Production Example 5 (Polyester Film F3a)

A polyester film F3a was obtained in the same manner as in Production Example 4 except that the coating layer was mixed in Production Example 4.

Production Example 6 (Polyester Film F4a)

A polyester film F4a was obtained in the same manner as in Production Example 4 except that the coating layer was mixed in Production Example 4.

Production Example 7 (Polyester Film F5a)

A polyester film F5a was obtained in the same manner as in Production Example 4 except that the coating layer was mixed in the production example 4.

Production Example 8 (Polyester Film F6a)

The raw material obtained by blending polyethylene terephthalate A1 and A2 in a ratio of 80% and 20%, respectively, is used as a surface layer raw material, and a raw material of polyethylene terephthalate A1=100% is used as an intermediate layer. The raw materials were supplied to two extruders equipped with vent holes, melt-extruded at 290 ° C, and then cooled and solidified on a cooling roll having a surface temperature of 40 ° C by electrostatic application to obtain a thickness of about 740 μm. Shaped film.

This film was stretched 2.8 times in the longitudinal direction at 90 ° C, 5.4 times in the transverse direction at 120 ° C, heat-treated at 200 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film. Then, the coating layer composed of the coating agent composition described below was applied by reverse gravure coating so as to have a coating amount (after drying) of 0.05 g/m ² , and then applied at 120 ° C for 30 seconds. After heat treatment, a polyester film F6a having a coating layer of 50 μm in thickness was obtained.

(coating layer composition)

AC1: Colcoat N-103X (manufactured by Colcoat)

AC2: ginseng (acetyl acetonate) aluminum

AC3: Tetraethylpyruvium pyruvate

AC4: titanium tetraacetate pyruvate

(mixing conditions)

AC1: 99.5 wt%

AC2: 0.5% by weight

AC3: 0% by weight

AC4: 0% by weight

Production Example 9 (Polyester Film F7a)

A polyester film F7a was obtained in the same manner as in Production Example 4 except that the coating layer was not provided in Production Example 4.

(release layer composition -A) Hardened polyoxyl resin

(LTC303E: Toray. Dow Corning) 100 copies

Hardener (SRX212: made by Toray Dow Corning) 1 part

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition - B)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition - C)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 10 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition -D)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 1 part

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

Example 1: <Manufacture of First Release Film>

The polyester film F1a was applied off-line, and the following release layer composition -A was applied by reverse gravure coating so as to have a coating amount (after drying) of 0.1 g/m ² at 120 ° C. Heat treatment for 30 seconds.

(release layer composition -A) Hardened polyoxyl resin

(LTC303E: Toray. Dow Corning) 100 copies

Hardener (SRX212: made by Toray Dow Corning) 1 part

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

From the above, the properties of the obtained first release film are shown in Tables 2 to 4. Furthermore, the embodiment numbers in Table 4 mean the following Table 5 The example number in the case (the same applies hereinafter).

<Manufacture of second release film>

In the polyester film F2a, the following release layer composition -D was applied to the coating layer so that the coating amount was 0.1 g/m ² (after drying), and the coating was applied by reverse gravure coating off-line. Heat treatment at °C for 30 seconds. The characteristics of the obtained second release film are shown in Tables 1 to 4.

(release layer composition - C)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 10 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

<Manufacture of non-substrate two-sided adhesive sheet>

On the release layer of the obtained second release film, a coating liquid composed of the following acrylic pressure-sensitive adhesive composition was applied by an applicator, and then heat-treated at 100 ° C for 5 minutes using a hot air circulating furnace. The coating amount (after drying) was an adhesive layer of 50 g/m ² .

<Acrylic adhesive layer forming composition> (monomer blending composition)

2-ethylhexyl acrylate 70% by weight

2-methoxyethyl acrylate 29% by weight

4-hydroxybutyl acrylate 1% by weight

To 100 parts by weight of the above monomer composition, CORONATE L and 0.1 part of CORONATE L manufactured by Japan Polyurethane were added to obtain a composition for forming an acrylic pressure-sensitive adhesive layer.

Next, using a 2 kg rubber roller, the release layer of the first release film and the adhesive layer were bonded to each other to obtain a substrate-free double-sided adhesive sheet. The properties of the obtained substrate-free double-sided adhesive sheet are shown in Table 5.

Example 2 to Example 6 and Comparative Example 1 to Comparative Example 3:

In the same manner as in Example 1, except that the coating agent composition, the release agent composition, and the thickness of the polyester film substrate were changed to those shown in Tables 2 and 3 below, Table 4 was obtained. The first release film and the second release film are shown. Thereafter, the two were bonded together via an adhesive layer to obtain a substrate-free two-sided adhesive sheet. The properties of the release film and the substrate-free double-sided adhesive sheet obtained in the above Examples and Comparative Examples are shown in Tables 2 to 5.

<Second invention>

The polyesters used in the examples and comparative examples were prepared as follows.

<Manufacture of polyester> Production Example 10 (polyethylene terephthalate A1)

100 parts of dimethyl terephthalate, 60 parts of ethylene glycol and 0.09 parts of magnesium acetate. 4 water salt were placed in the reactor, and the mixture was heated and heated to distill off methanol, and the transesterification reaction was started. The reaction started for 4 hours. The transesterification reaction was substantially terminated to 230 °C. Next, 0.04 parts of ethylene glycol slurry ethyl acid phosphate and 0.03 parts of antimony trioxide were added, and the temperature was brought to 280 ° C in 100 minutes, and the pressure was 15 mmHg. Thereafter, the pressure was gradually reduced, and finally 0.3 mmHg. After 4 hours, the system was returned to normal pressure to obtain polyethylene terephthalate A1 having an intrinsic viscosity of 0.61.

Production Example 11 (polyethylene terephthalate A2)

In the same manner as in Production Example 1, except that 0.6 parts of cerium oxide particles having an average particle diameter of 2.5 μm were added in the production example 10, polyethylene terephthalate A2 having an intrinsic viscosity of 0.62 was obtained.

Production Example 12 (polyethylene terephthalate A3)

In the same manner as in Production Example 10 except that 1.0 part of the synthetic calcium carbonate particles having an average particle diameter of 0.8 μm was added, the polyethylene terephthalate A3 having an intrinsic viscosity of 0.62 was obtained.

Production Example 13 (Polyester Film F1b)

The raw materials obtained by blending polyethylene terephthalate A1 and A3 at a ratio of 92% and 8%, respectively, are used as a surface material to make polyethylene terephthalate A1 and A3 80%, respectively. The raw material blended in a ratio of 20% is used as an intermediate layer raw material, supplied to two extruders with vent holes, and supplied to an extruder equipped with a vent hole, and melt-extruded at 290 ° C to use electrostatic printing. The film was condensed and solidified on a cooling roll having a surface temperature of 40 ° C to obtain an amorphous film having a thickness of about 1300 μm.

The film was stretched 3.5 times in the longitudinal direction at 90 ° C, and extended 4.1 times in the transverse direction at 130 ° C, and heat-treated at 230 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film F1b.

Production Example 14 (Polyester Film F2b)

The raw materials obtained by blending polyethylene terephthalate A1 and A3 at a ratio of 92% and 8%, respectively, are used as a surface material to make polyethylene terephthalate A1 and A3 80%, respectively. The raw material blended in a ratio of 20% is used as an intermediate layer raw material, and is supplied to two extruders with vent holes. After melt extrusion at 290 ° C, the surface temperature is set to 40 ° C using electrostatic printing. The cooling roll was cooled and solidified to obtain an amorphous film having a thickness of about 740 μm.

The film was stretched 3.5 times in the longitudinal direction at 90 ° C, and extended 4.1 times in the transverse direction at 130 ° C, and heat-treated at 230 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film. Then, the coating layer composed of the coating agent composition described below was applied by reverse gravure coating so as to have a coating amount (after drying) of 0.05 g/m ² , and then applied at 120 ° C for 30 seconds. After heat treatment, a polyester film F2b having a coating layer having a thickness of 50 μm was obtained.

(coating layer composition)

AC1: Colcoat N-103X (manufactured by Colcoat)

AC2: ginseng (acetyl acetonate) aluminum

AC3: Tetraethylpyruvium pyruvate

AC4: titanium tetraacetate pyruvate

(mixing conditions)

AC1: 99.5 wt%

AC2: 0.5% by weight

AC3: 0% by weight

AC4: 0% by weight

Production Example 15 (Polyester Film F3b)

A polyester film F3b was obtained in the same manner as in Production Example 14 except that the coating layer was mixed in the production example 14.

Production Example 16 (Polyester Film F4b)

A polyester film F4b was obtained in the same manner as in Production Example 14 except that the coating layer was mixed in Production Example 14.

Production Example 17 (Polyester Film F5b)

A polyester film F5b was obtained in the same manner as in Production Example 14 except that the coating layer was mixed in the production example 14.

Production Example 18 (Polyester Film F6b)

The raw materials obtained by blending polyethylene terephthalate A1 and A3 at a ratio of 92% and 8%, respectively, are used as a surface material to make polyethylene terephthalate A1 and A3 80%, respectively. The raw material blended in a ratio of 20% is used as an intermediate layer raw material, and is supplied to two extruders with vent holes. After melt extrusion at 290 ° C, the surface temperature is set to 40 ° C using electrostatic printing. The cooling roll was cooled and solidified to obtain an amorphous film having a thickness of about 740 μm. The film was stretched 2.8 times in the longitudinal direction at 90 ° C, 5.4 times in the transverse direction at 120 ° C, heat-treated at 200 ° C, and then subjected to a relaxation treatment of 4.3% in the width direction to obtain a thickness of 50 μm (thickness composition ratio = 2.5 μm). /45 μm / 2.5 μm) polyester film. Then, the coating layer composed of the coating agent composition described below was applied by reverse gravure coating so as to have a coating amount (after drying) of 0.05 g/m ² , and then applied at 120 ° C for 30 seconds. After heat treatment, a polyester film F6b having a coating layer having a thickness of 50 μm was obtained.

(coating layer composition)

AC1: Colcoat N-103X (manufactured by Colcoat)

AC2: ginseng (acetyl acetonate) aluminum

AC3: Tetraethylpyruvium pyruvate

AC4: titanium tetraacetate pyruvate

(mixing conditions)

AC1: 99.5 wt%

AC2: 0.5% by weight

AC3: 0% by weight

AC4: 0% by weight

Production Example 19 (Polyester Film F7b)

A polyester film F7b was obtained in the same manner as in Production Example 14 except that the coating layer was not provided in Production Example 14.

Production Example 20 (Polyester film F8b)

In the same manner as in Production Example 14, except that the raw material of the surface layer and the intermediate layer was mixed and the coating layer was not formed as described below, a polyester film F8b was obtained.

Surface material: A raw material obtained by blending polyethylene terephthalate A1 and A2 in a ratio of 80% or 20%, respectively.

Intermediate layer material: Raw material of polyethylene terephthalate A1 = 100% was used.

(release layer composition -A) Hardened polyoxyl resin

(LTC303E: Toray. Dow Corning) 100 copies

Hardener (SRX212: made by Toray Dow Corning) 1 part

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition - B)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition - C)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 10 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

(release layer composition -D)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 1 part

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

Example 7 <Manufacture of First Release Film>

In the polyester film F1b, the following release layer composition -A was applied by reverse gravure coating method at a coating amount (after drying) of 0.1 g/m ² at 120 ° C, 30 Second heat treatment.

(release layer composition -A) Hardened polyoxyl resin

(LTC303E: Toray. Dow Corning) 100 copies

Hardener (SRX212: made by Toray Dow Corning) 1 part

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

From the above, the properties of the obtained first release film are shown in Tables 6 to 8. Incidentally, the example numbers in Table 8 mean the example numbers (the same applies hereinafter) in Table 9 to be described later.

<Manufacture of second release film> Polyester film F

In 2b, on the coating layer, the following release layer composition -D was applied by a reverse gravure coating method in a manner that the coating amount was 0.1 g/m ² (after drying). Heat treatment at °C for 30 seconds. The characteristics of the obtained second release film are shown in Tables 6 to 8.

(release layer composition - C)

Hardened polyoxyl resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts

Heavy peeling control agent (BY24-4980: made by Toray Dow Corning) 10 parts

Hardener (PL-50T: Shin-Etsu Chemical) 1 copy

MEK/toluene mixed solvent (mixing ratio 1:1) 1500 parts

<Manufacture of non-substrate two-sided adhesive sheet>

On the release layer of the obtained second release film, a coating liquid composed of the following acrylic pressure-sensitive adhesive composition was applied by an applicator, and then heat-treated at 100 ° C for 5 minutes using a hot air circulating furnace. The coating amount (after drying) was an adhesive layer of 50 μm.

<Acrylic adhesive layer forming composition> (monomer blending composition)

2-ethylhexyl acrylate 70% by weight

2-methoxyethyl acrylate 29% by weight

4-hydroxybutyl acrylate 1% by weight

To 100 parts by weight of the above monomer composition, CORONATE L and 0.1 part of Japan Polyurethane were added to obtain an acrylic pressure-sensitive adhesive layer. Composition.

Next, using a 2 kg rubber roller, the release layer of the first release film and the adhesive layer were bonded to each other to obtain a substrate-free double-sided adhesive sheet.

Example 8 to Example 12 and Comparative Example 4 to Comparative Example 7:

In the same manner as in Example 7, except that the coating agent composition, the release agent composition, and the thickness of the polyester film substrate were changed to those shown in the following Tables 6 and 7, the results of Table 8 were obtained. The first release film and the second release film are shown. Thereafter, the two were bonded together via an adhesive layer to obtain a substrate-free two-sided adhesive sheet. The properties of the release film and the non-substrate double-sided adhesive sheet obtained in the above examples and comparative examples are shown in Tables 6 to 9.

[Industrial availability]

The substrate-free double-sided adhesive sheet of the present invention is excellent in antistatic property, mold release property, oligomer sealing property, and ease of inspection, and is suitable as, for example, a liquid crystal polarizing plate manufacturing device or a capacitive touch panel manufacturing member. Various optical components.

10‧‧‧No substrate double-sided adhesive sheet

11‧‧‧Adhesive layer

13‧‧‧1st release film substrate

14‧‧‧1st coating layer

15‧‧‧1st release agent layer

23‧‧‧Second release film substrate

24‧‧‧2nd coating layer

25‧‧‧Second release agent layer

31‧‧‧1st release film (light release sheet)

32‧‧‧Second release film (heavy release sheet)

Claims (5)

A non-substrate two-sided adhesive sheet characterized in that a release film is laminated on both sides of an adhesive layer, and a release force of one release film (first release film) is released from the other In the non-substrate double-sided adhesive sheet in which the peeling force of the film (second release film) is smaller, the second release film satisfies the conditions (a) to (c) described below, and (a) is set in the double a surface of a coating layer containing a hydrolyzable cerium compound on a shaft-extending polyester film, a release film provided with a release layer; (b) a variation of an alignment angle of the biaxially stretched polyester film in the plane of 6 degrees /500 mm or less; (c) The amount of the oligomer extracted from the surface of the release layer of the release film by dimethylformamide is 0.5 mg/m ² or less. A non-substrate two-sided adhesive sheet characterized in that, in the non-substrate two-sided adhesive sheet of claim 1, the first release film has a film haze of 6% or more. The substrate-free two-sided adhesive sheet of claim 1 or 2, wherein the hydrolyzable hydrazine compound is a compound represented by the following general formula, [Chemical Formula 1] Si(OR ¹ ) × (R ² ) _4-x (only, x An integer of 2 to 4, R ¹ represents an alkyl group or a fluorenyl group, and R ² represents an organic group having 1 to 10 carbon atoms. The substrate-free double-sided adhesive sheet according to any one of claims 1 to 3, wherein the coating layer of the second release film contains an organic compound containing a metal element. The non-substrate adhesive sheet according to claim 4, wherein the blending ratio (weight ratio) of the hydrolyzable cerium compound (A) to the organic compound (B) containing the metal element (A): (B) is 1:0.001 1:0.01 range.