JP2015063028A - Release sheet and pressure-sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet which hardly imparts adverse influences to precision electronic apparatuses or the like, has a weak release force and can perform transfer application of a pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet including the release sheet.SOLUTION: A release sheet 1 includes a release substrate 11 and a release agent layer 12 formed on at least one surface of the release substrate 11. The release agent layer 12 contains substantially no silicone compound; and the release agent layer 12 is formed from a release agent composition comprising a perfluoropolyether compound having a hydroxyl group as a functional group, and a polyfunctional amino compound as a crosslinking agent.

Description

  The present invention relates to a release sheet and a pressure-sensitive adhesive sheet provided with the release sheet.

  In recent years, pressure-sensitive adhesive sheets have been used in various forms at various stages in the manufacturing process of precision electronic devices such as ceramic capacitors, hard disk drives, and semiconductor devices.

  Such a pressure-sensitive adhesive sheet is usually composed of a base material and a pressure-sensitive adhesive layer, and a release sheet is laminated on the pressure-sensitive adhesive layer before the sticking. A release agent layer is usually provided on the contact surface of the release sheet with the pressure-sensitive adhesive layer for the purpose of improving peelability.

  In pressure sensitive adhesive sheets used for general purposes other than precision electronic equipment, silicone compounds are often used in the release agent layer of the release sheet, but when silicone compounds are used for applications related to precision electronic equipment, the release agent The low molecular weight silicone compound contained in the layer may migrate to the pressure-sensitive adhesive layer and remain in the precision electronic device, and the low molecular weight silicone compound may cause trouble in the precision electronic device. Especially in the case of a hard disk drive, such a trouble is likely to occur.

  Therefore, as a non-silicone release agent, a long-chain alkyl resin (see, for example, Patent Document 1) or an olefin resin (see, for example, Patent Document 2) is used as a non-silicone release agent for a release layer for an adhesive sheet used for precision electronic equipment. Has been tried to use. However, release sheets using these non-silicone release agents have poor release properties, and the pressure-sensitive adhesive layer and the release agent layer may be difficult to release.

  Further, a release sheet using a polyfluoropolyether containing at least two reactive groups and an inert polyfluoropolyether oil as a release agent layer has been proposed (see Patent Document 3).

JP 2002-249757 A JP 2004-162048 A Japanese Patent No. 3009744

  However, in the release sheet described in Patent Document 3, the release agent layer is inferior in heat resistance and solvent resistance due to the inert polyfluoropolyether oil. In the production process of the pressure-sensitive adhesive sheet, a transfer coating method is often employed in which a pressure-sensitive adhesive solution is applied onto the release agent layer of the release sheet, and the adhesive layer with the release sheet is bonded to the substrate after heat drying. At that time, because of the above reasons, the peeling force between the pressure-sensitive adhesive layer and the release agent layer is increased by the transfer coating of the pressure-sensitive adhesive. Therefore, the release sheet described in Patent Document 3 is sufficient as a release sheet. The performance could not be demonstrated.

  The present invention has been made in view of such a situation, and is a release sheet that does not adversely affect precision electronic devices and the like, has a low peeling force, and can also be applied with a pressure sensitive adhesive. It aims at providing the adhesive sheet provided with the sheet.

  In order to achieve the above object, first, the present invention provides a release sheet comprising a release substrate and a release agent layer formed on at least one surface of the release substrate, the release agent The layer is substantially free of a silicone compound, and the release agent layer is formed of a release agent composition containing a perfluoropolyether compound having a hydroxyl group as a functional group and a polyfunctional amino compound as a crosslinking agent. A release sheet is provided (Invention 1).

  In the release sheet according to the above invention (Invention 1), since the release agent layer does not substantially contain a silicone compound, it is difficult to adversely affect precision electronic devices and the like. Moreover, when the release agent layer is formed of a release agent composition containing a perfluoropolyether compound having a hydroxyl group and a polyfunctional amino compound, the release sheet has a lower release force, and the adhesive is transferred. Coating is also possible.

  In the said invention (invention 1), it is preferable that the said perfluoropolyether compound has a hydroxyl group at both ends (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said polyfunctional amino compound is a methylated melamine resin (invention 3).

  In the said invention (invention 1-3), it is preferable that content of the said polyfunctional amino compound is 1-75 mass parts with respect to 100 mass parts of said perfluoro polyether compounds (invention 4).

  In the said invention (invention 1-4), it is preferable that the weight average molecular weights of the said perfluoro polyether compound are 500-10000 (invention 5).

  In the said invention (invention 1-5), it is preferable that the said releasing agent composition further contains p-toluenesulfonic acid as a catalyst (invention 6).

  2ndly, this invention provides the adhesive sheet provided with the said peeling sheet (invention 1-6) and the adhesive layer provided so that the said releasing agent layer of the said peeling sheet might be contact | connected. (Invention 7).

  The release sheet according to the present invention is less likely to adversely affect precision electronic devices and the like, has a low release force, and can be applied with a pressure sensitive adhesive. In addition, the pressure-sensitive adhesive sheet according to the present invention is unlikely to adversely affect precision electronic devices and the like, and can peel the release sheet with a low release force.

It is sectional drawing of the peeling sheet which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Peeling sheet]
As shown in FIG. 1, the release sheet 1 according to this embodiment includes a release substrate 11 and a release agent layer 12 formed on one surface of the release substrate 11.

  There is no restriction | limiting in particular as the peeling base material 11, Arbitrary things can be suitably selected and used from conventionally well-known things. Examples of the peeling substrate 11 include paper substrates such as glassine paper, coated paper, cast coated paper, dust-free paper, and fine paper; laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper substrates. Or polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, plastic films such as polycarbonate films and cellulose acetate films; non-woven fabrics; metal foils; or laminated sheets containing these; Can be mentioned.

  In the peeling base material 11 made of the above plastic film, for the purpose of improving the adhesiveness with the release agent layer 12 provided on the surface, a surface treatment by an oxidation method or a concavo-convex method on one side or both sides as desired, Alternatively, primer treatment can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method. These surface treatment methods are appropriately selected according to the type of the base film, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  The thickness of the peeling base material 11 should just be 10-300 micrometers normally, Preferably it is 15-200 micrometers, Most preferably, it is 20-125 micrometers.

  The release agent layer 12 in this embodiment is formed by the following release agent composition. The release agent composition in this embodiment contains a perfluoropolyether compound having a hydroxyl group as a functional group and a polyfunctional amino compound as a crosslinking agent.

  The release agent layer 12 in the present embodiment is formed by curing the release agent composition. Specifically, the release agent layer 12 has a structure obtained by crosslinking a perfluoropolyether compound having a hydroxyl group with a polyfunctional amino compound via the hydroxyl group. Such a release agent layer 12 has a low peeling force, that is, an excellent light release property. Further, the release agent layer 12 is excellent in heat resistance and solvent resistance, and therefore, transfer coating of an adhesive is also possible.

  The perfluoropolyether compound preferably has hydroxyl groups at both ends of the molecule, and particularly preferably has hydroxyl groups only at both ends of the molecule. Thereby, a perfluoro polyether compound will be bridge | crosslinked by the polyfunctional amino compound in the both terminal. According to this structure, the light release property and the transfer coating property of the pressure-sensitive adhesive are more excellent.

As the perfluoropolyether compound having a hydroxyl group at both ends, a perfluoropolyether diol represented by the following general formula (1) is preferable.
HO—R ¹ —R ² —O— (R ³ O) _n —R ² —R ¹ —OH (1)
(In Formula (1), R ¹ each independently represents a single bond, a methylene group or an ethylene group, R ² and R ³ each independently represent a methylene fluoride or a C 2-4 perfluoroalkylene group, n is an integer of 5-50.)

  Among the perfluoropolyether diols represented by the general formula (1), a terminal diol compound of perfluoropolyethylene oxide or a terminal diol compound of perfluoropolypropylene oxide is preferable.

  The weight average molecular weight (Mw) of the perfluoropolyether compound having a hydroxyl group as the functional group is preferably 500 to 10,000, and more preferably 1,000 to 5,000. When the weight average molecular weight of the perfluoropolyether compound is within the above range, the light release property of the resulting release agent layer 12 and the transfer coating property of the pressure-sensitive adhesive are more excellent.

  On the other hand, examples of the polyfunctional amino compound include melamine resins such as methylated melamine resins and butylated melamine resins; urea resins such as methylated urea resins and butylated urea resins; benzoguanamine resins such as methylated benzoguanamine resins; Diamines such as tetramethylenediamine, hexamethylenediamine, N, N′-diphenylethylenediamine, and p-xylenediamine, and the like can be used alone or in combination of two or more. Among these, methylated melamine resin is particularly preferable. The methylated melamine resin is excellent in curability, that is, excellent in light releasability without adversely affecting the releasability by the perfluoropolyether compound. Furthermore, by using a methylated melamine resin, the effect of improving the adhesion of the obtained release agent layer 12 to the release substrate 11, particularly the release substrate 11 made of a plastic film, is also obtained.

  The content of the polyfunctional amino compound in the release agent composition (release agent layer 12) is preferably 1 to 75 parts by mass, particularly 3 to 50 parts per 100 parts by mass of the perfluoropolyether compound. The amount is preferably part by mass, and more preferably 5 to 30 parts by mass. When the content of the polyfunctional amino compound is 1 part by mass or more, crosslinking of the perfluoropolyether compound (curing of the release agent composition) is sufficiently performed. On the other hand, when the content of the polyfunctional amino compound is 75 parts by mass or less, the resulting release agent layer 12 can be prevented from being heavily peeled.

  In addition, when an isocyanate compound is used as the crosslinking agent instead of the polyfunctional amino compound, there arises a problem that the peeling force of the resulting release agent layer 12 is increased.

  The release agent composition preferably contains a catalyst. The catalyst is not particularly limited as long as it can promote the crosslinking reaction between the perfluoropolyether compound and the polyfunctional amino compound and accelerate the curing of the release agent composition. An acid catalyst such as p-toluenesulfonic acid is preferred, and p-toluenesulfonic acid is particularly preferred. According to the acid catalyst, particularly p-toluenesulfonic acid, the curing reaction of the release agent composition can be more efficiently accelerated.

  The content of the catalyst in the release agent composition is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the total solid content of components other than the catalyst.

  In addition to the perfluoropolyether compound, polyfunctional amino compound and catalyst, the release composition may contain an antioxidant and the like. However, a perfluoropolyether compound having no functional group (for example, an inert polyfluoropolyether oil as described in Patent Document 3) adversely affects the peelability when the adhesive is transferred and applied. Therefore, it is preferable not to contain substantially.

  The thickness of the release agent layer 12 is preferably 10 nm to 1 μm, and particularly preferably 20 to 500 nm. When the thickness of the release agent layer 12 is 10 nm or more, desired light releasability is obtained. On the other hand, when the release agent layer 12 has a thickness of 1 μm or less, the wound release sheet 1 is less likely to cause blocking.

  The release agent layer 12 can be formed by applying a release agent composition and a coating solution containing a diluent as desired to one surface of the release substrate 11, and then drying and curing. As the coating method, for example, gravure coating method, bar coating method, spray coating method, spin coating method, knife coating method, roll coating method, die coating method and the like can be used.

  There is no restriction | limiting in particular as said diluent, A various thing can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof are used.

  The release agent composition applied as described above is preferably heat-cured. In this case, the heating temperature is preferably 80 to 180 ° C., and the heating time is preferably about 10 to 90 seconds.

  The release agent layer 12 thus formed is excellent in light release properties. Specifically, the release sheet 1 according to the present embodiment can achieve a peel force of 1000 mN / 50 mm or less, preferably 500 mN / 50 mm or less, particularly preferably 30 to 400 mN / 50 mm. In addition, the measuring method of peeling force here is as showing to the test example mentioned later. When the peeling force is in the above range, it is possible to reduce the peeling failure when peeling the release sheet 1 from the pressure-sensitive adhesive sheet.

  In the production process of the pressure-sensitive adhesive sheet, a transfer coating method is often employed in which a pressure-sensitive adhesive liquid is applied onto the release agent layer of the release sheet and dried by heating, and then the pressure-sensitive adhesive layer with release sheet is bonded to the substrate. In the case of transfer coating, the release agent layer is exposed to the solvent and heat in the pressure-sensitive adhesive, so the conventional release agent layer other than the silicone compound increases the release force, and the desired release performance cannot be obtained. It was. On the other hand, the release agent layer 12 in this embodiment is excellent in heat resistance and solvent resistance. Therefore, even if the adhesive coating liquid in a heated state is transferred and applied to the release agent layer 12 of the release sheet 1, the release force between the obtained adhesive layer and the release agent layer 12 is high. The above-mentioned excellent light peelability is maintained without becoming. That is, the release sheet 1 according to this embodiment is capable of transfer coating of an adhesive.

  Here, the release agent layer 12 in the present embodiment does not substantially contain a silicone compound. And even if the release agent layer 12 in this embodiment does not contain a silicone type compound substantially, as mentioned above, it is excellent in light peelability. According to the release sheet 1 having such a release agent layer 12, there is no fear that the silicone compound will migrate from the release agent layer 12 to the pressure-sensitive adhesive layer in contact with the release agent layer 12. There is no risk of adverse effects.

The phrase “substantially free of a silicone compound” means that the content of the silicone compound is an amount that does not adversely affect the precision electronic device due to the silicone compound. Specifically, the amount of the silicone compound in the release agent layer 12 is preferably 250 μg / m ² or less, particularly preferably 50 μg / m ² or less.

[Adhesive sheet]
The pressure-sensitive adhesive sheet according to the present embodiment includes the release sheet described above and a pressure-sensitive adhesive layer provided so as to be in contact with the release agent layer of the release sheet, and may be a single-sided pressure-sensitive adhesive sheet, A double-sided PSA sheet may be used. In the case of a single-sided pressure-sensitive adhesive sheet, it comprises a release sheet, a pressure-sensitive adhesive layer provided in contact with the release agent layer of the release sheet, and a base material laminated on the side opposite to the release sheet in the pressure-sensitive adhesive layer Is done. Moreover, in the case of a double-sided adhesive sheet, it is comprised including two release sheets and the adhesive layer provided in contact with the release agent layer of each release sheet between these release sheets. In the case of a double-sided pressure-sensitive adhesive sheet, a support base material may be provided in the vicinity of the central portion in the thickness direction of the pressure-sensitive adhesive layer. This support substrate has a function of supporting two pressure-sensitive adhesive layers located on both sides thereof and imparting strength.

(1) Release sheet In the case of a single-sided adhesive sheet, as the release sheet, the release sheet according to the present embodiment described above and having a desired release force may be used.

  In the case of a double-sided pressure-sensitive adhesive sheet, as the release sheet, the release sheet according to this embodiment described above may be used for both of the two release sheets, or may be used for only one side. In any case, it is preferable to use two release sheets having a difference in peel force. Specifically, it is preferable that one release sheet and the other release sheet have a peel force difference of 2 times or more, and it is particularly preferable to have a peel force difference of 3 times or more. By having the said peeling force difference, the peeling sheet of the one peeled first can be easily removed, without damaging the surface of an adhesive layer.

  The peeling force difference as described above can be set by adjusting the composition of the release agent composition constituting the release agent layer of the release sheet or by changing the thickness of the release agent layer.

(2) Pressure-sensitive adhesive layer The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be appropriately selected according to the use of the pressure-sensitive adhesive sheet. For example, an acrylic pressure-sensitive adhesive, a polyester pressure-sensitive adhesive, a polyurethane pressure-sensitive adhesive, and a rubber pressure-sensitive adhesive Any of these may be used. The pressure-sensitive adhesive may be any of an emulsion type, a solvent type, or a solventless type, and may be a crosslinked type or a non-crosslinked type.

  Among the above, a crosslinked structure formed by a reaction between a crosslinking agent and a polymer having a reactive functional group that is a functional group capable of reacting with the crosslinking agent (also referred to as “crosslinkable polymer” in the present specification). It is preferable to use an acrylic pressure-sensitive adhesive (hereinafter referred to as “acrylic pressure-sensitive adhesive A”).

(2-1) Crosslinkable polymer The structural unit of a crosslinkable polymer is not specifically limited. A compound having a (meth) acryloyl group and a derivative thereof (ester, acrylonitrile, etc.) may be composed of only a structural unit based on an acrylic compound which is one or two or more compounds, or a structure based on an acrylic compound The structural unit based on compounds other than a unit and an acryl-type compound may be included. In the present specification, the “(meth) acryloyl group” means both an acryloyl group and a methacryloyl group. The same applies to other similar terms. Moreover, compounds other than said acrylic compound may be comprised from one type of compound, and may be comprised from multiple types of compound.

  A preferred example of the acrylic compound is (meth) acrylic acid ester. Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2 as compounds having no reactive functional group. -(Meth) acrylate having a chain skeleton such as ethylhexyl (meth) acrylate; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl Examples thereof include (meth) acrylates having a cyclic skeleton such as (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and imide acrylate. Examples of the compound having a reactive functional group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3- (Meth) acrylate having a hydroxyl group such as hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; (meth) acrylate having an amino group such as N-methylaminoethyl (meth) acrylate; glycidyl (meth) acrylate (Meth) acrylates having an epoxy group such as

  Monomers that give structural units based on compounds other than acrylic compounds (hereinafter also referred to as “other polymerizable compounds”), olefins such as ethylene and norbornene, carboxylic acid vinyl esters such as vinyl acetate, and ethylenics such as styrene Examples include aromatic compounds having an unsaturated bond, N-vinylmorpholine, N-allylmorpholine, and ethylenically unsaturated group-containing morpholine compounds such as N- (meth) acryloylmorpholine.

  The monomer mass content of the structural unit based on the reactive functional group in the crosslinkable polymer is preferably 0.1 to 10% by mass, and particularly preferably 0.5 to 5% by mass.

(2-2) Crosslinking agent As the crosslinking agent contained in the acrylic pressure-sensitive adhesive A, an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent or a chelating crosslinking agent can be preferably used. Examples of isocyanate crosslinking agents include tolylene diisocyanate (TDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate, trimethylolpropane modified TDI. Etc. are used. Examples of the epoxy crosslinking agent include ethylene glycol glycidyl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidyl amine and the like. Examples of the aziridine-based crosslinking agent include 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], 4,4-bis (ethyleneiminocarboxyamino) diphenylmethane, and tris-2,4,6. -(1-aziridinyl) -1,3,5-triazine, tris [1- (2-methyl) aziridinyl] phosphine oxide, hexa [1- (2-methyl) -aziridinyl] triphosphatriazine and the like are used. Examples of the chelate-based crosslinking agent include aluminum chelate and titanium chelate.

  The usage-amount of a crosslinking agent is 0.01-10 mass parts normally with respect to 100 mass parts of solid content in an adhesive, Preferably it is 0.05-5 mass parts. Not only one type of crosslinking agent is used alone, but two or more types of crosslinking agents may be used in combination as required.

  The pressure-sensitive adhesive layer made of the acrylic pressure-sensitive adhesive A has a gel fraction of preferably 10 to 70%, particularly preferably 20 to 60%. The content of the crosslinking agent in the acrylic pressure-sensitive adhesive A before the reaction for forming a crosslinked structure proceeds is usually in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the crosslinkable polymer. By adjusting, it becomes easy to make the gel fraction of an adhesive layer into said range.

(2-3) Other components The acrylic adhesive A can contain various components in addition to the components described above. For example, crosslinking accelerators; coloring materials such as dyes and pigments; antioxidants such as anilides and phenols; ultraviolet absorbers such as benzophenones and benzotriazoles; filler components such as talc, titanium dioxide, silica, and starch; Examples include plasticizers; light stabilizers; dispersants; leveling agents. However, it is preferable that these components do not easily generate outgas.

  The thickness of the pressure-sensitive adhesive layer is generally preferably 1 to 100 μm, particularly preferably 3 to 30 μm, and more preferably 5 to 25 μm as the whole pressure-sensitive adhesive layer (excluding the supporting base material). Is preferred.

(3) Base material There is no restriction | limiting in particular as a base material used with a single-sided adhesive sheet, Arbitrary things can be suitably selected and used from conventionally well-known things. Examples of such a substrate include a resin film, a metal film, a resin film on which a metal is deposited, and a laminate thereof.

  Examples of the resin film include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyvinyl chloride, polystyrene, polyurethane, polycarbonate, polyamide, polyimide, polyetherimide, and poly (meth). Acrylic acid ester, polybutene, polybutadiene, polymethylpentene, acrylic urethane, ethylene vinyl acetate copolymer, ethylene (meth) acrylic acid copolymer, ethylene (meth) acrylic acid ester copolymer, ABS resin, ionomer resin, various A film made of a resin such as a thermoplastic elastomer, a foamed film, a laminated film thereof, a synthetic paper, or the like can be used.

  The resin film may be transparent, translucent or opaque. The resin film may be a stretched film, an unstretched film, or may be formed by a casting method using a process material. Furthermore, the resin film may contain various additives such as an inorganic filler, an organic filler, and an ultraviolet absorber.

  One or both surfaces of the resin film can be subjected to a surface treatment by an oxidation method, an unevenness method, or the like. Such surface treatment improves the adhesiveness of the pressure-sensitive adhesive layer laminated on the resin film. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method. These surface treatment methods are appropriately selected depending on the type of the resin film, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability. Further, a primer treatment for providing a primer layer (specific examples include silane coupling treatment) can also be applied.

  Although the thickness of a base material is not specifically limited, Usually, it is 10-300 micrometers, Preferably it is 20-150 micrometers.

  In addition, it is preferable that the thickness of the whole single-sided adhesive sheet shall be about 400 micrometers or less, and it is more preferable to set it as 180 micrometers or less. On the other hand, from the viewpoint of ensuring handleability, the thickness of the entire single-sided PSA sheet is preferably 15 μm or more, and more preferably 25 μm or more.

(4) Support base material The material constituting the support base material that supports the pressure-sensitive adhesive layer in the double-sided pressure-sensitive adhesive sheet has a basic function to be possessed as a support base material, such as higher tensile strength than the material constituting the pressure-sensitive adhesive layer. As long as it is, it is not particularly limited. However, when used in precision electronic equipment, it is preferable that organic gas is not easily generated.

  Specific examples of the material constituting the supporting substrate include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyimides; resin films such as polyamide. You may use what gave metal vapor deposition, such as aluminum, to these resin films. Alternatively, papers made of synthetic paper, impregnated paper, and the like, and metal foils such as aluminum foil and copper foil can also be given as specific examples of the material constituting the support base material.

  In the case of using a resin film as a support substrate, in order to improve the adhesiveness with the pressure-sensitive adhesive layer laminated on the resin film, the oxidation method, Surface treatment such as an uneven method or primer treatment can be performed.

  The thickness of the support substrate is not particularly limited. When it is too thin, it is difficult to handle the support base material, and it is difficult to enjoy the benefits of providing the support base material (eg, the double-sided pressure-sensitive adhesive sheet is difficult to break). There is concern about becoming. On the other hand, when the supporting substrate is excessively thick, there is a concern that the entire double-sided PSA sheet becomes thick. Therefore, the thickness of the supporting substrate is usually preferably in the range of about 2 to 50 μm, and preferably in the range of about 3 to 20 μm.

  The thickness of the entire double-sided PSA sheet is preferably about 100 μm or less, and more preferably 65 μm or less. On the other hand, from the viewpoint of ensuring handleability, the thickness of the entire double-sided PSA sheet is preferably 10 μm or more, and more preferably 20 μm or more.

(5) Production method of pressure-sensitive adhesive sheet As a production example of a single-sided pressure-sensitive adhesive sheet, first, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer and optionally a diluent are contained on the release agent layer of the release sheet according to this embodiment. After apply | coating a coating liquid, it is made to dry (it hardens depending on the case), and an adhesive layer is formed. Application | coating of a coating liquid can be performed using coating machines, such as a bar coater, a die coater, a gravure coater, a roll coater, a knife coater, for example.

  There is no restriction | limiting in particular as said diluent, A various thing can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof are used.

  When the pressure-sensitive adhesive is a crosslinked type, particularly in the case of the acrylic pressure-sensitive adhesive A described above, it is preferable that the applied pressure-sensitive adhesive is thermally crosslinked. In this case, the heating temperature is preferably 60 to 130 ° C., and the heating time is preferably about 30 to 300 seconds.

  After forming the pressure-sensitive adhesive layer on the release layer of the release sheet as described above to obtain the pressure-sensitive adhesive layer with release sheet, the pressure-sensitive adhesive with release sheet so that the pressure-sensitive adhesive layer and the substrate are in contact with each other. A layer and a base material are bonded together to obtain a single-sided pressure-sensitive adhesive sheet. According to the release sheet according to the present embodiment, an adhesive sheet can be obtained by the transfer coating method as described above without using a silicone compound in the release agent layer.

  In addition to the manufacturing method described above, the release sheet and the pressure-sensitive adhesive are formed so that a pressure-sensitive adhesive layer is formed on one surface of the substrate, and the release layer of the release sheet according to this embodiment is in contact with the pressure-sensitive adhesive layer. A single-sided PSA sheet may be obtained by laminating layers.

  As one production example of the double-sided pressure-sensitive adhesive sheet, as the first laminate, a pressure-sensitive adhesive layer is formed on the release agent layer of the release sheet, and a support base material is laminated on the pressure-sensitive adhesive layer as desired. As a laminate, an adhesive layer is formed on the release agent layer of the release sheet. And the adhesive layer or support base material of a 1st laminated body and the adhesive layer of a 2nd laminated body are bonded together, and a double-sided adhesive sheet is obtained.

  The residual adhesive rate of the pressure-sensitive adhesive sheet according to this embodiment is preferably 50% or more, particularly preferably 60% or more, and more preferably 70% or more. In addition, the residual adhesive rate here is measured by the method shown in the test example mentioned later. According to the release sheet according to the present embodiment, transfer of a release agent component such as a low molecular weight silicone compound or a fluorine compound from the release agent layer to the pressure-sensitive adhesive layer is very little, so the above-mentioned residual adhesion rate is possible. It becomes. Therefore, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to this embodiment can maintain a desired pressure-sensitive adhesive force without being adversely affected by the release sheet.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, the release agent layer 12 may be formed on both surfaces of the release substrate 11 of the release sheet 1, or the release agent layer 12 on one surface of the release substrate 11 and the other surface of the release substrate 11. Another release agent layer may be formed. Further, another layer may be provided between the surface of the release sheet 1 opposite to the release agent layer 12 and between the release substrate 11 and the release agent layer 12.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Production of release sheet Perfluoropolyether compound having hydroxyl groups at both ends as a functional group (manufactured by Solvay Solexis, product name: FLUOLOLLINK D10H, weight average molecular weight: 1500, solid content concentration: 100 mass%) 100 mass And 10 parts by mass of a methylated melamine resin (manufactured by Nippon Cytec Industries, product name: Cymel 303, solid content concentration: 100% by mass) as a crosslinking agent, and methanol solution of p-toluenesulfonic acid (solid) (Partial concentration: 50% by mass) and 2 parts by mass, diluted with a fluorine solvent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: FS thinner) so that the solids concentration is about 1% by mass, and this is peeled off It was set as the coating liquid for agent layers.

  The obtained coating solution is uniformly applied to a single side of a polyethylene terephthalate film (Toray Industries, Lumirror # 50T-60, thickness 50 μm) as a peeling substrate with a Meyer bar so that the film thickness after drying becomes 150 nm. After coating, the release agent layer was cured by drying at 150 ° C. for about 1 minute. In this way, a release sheet having a release agent layer formed on the release substrate was obtained.

(2) Production of pressure-sensitive adhesive sheet In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device and a nitrogen introducing tube, 70 parts by mass of 2-ethylhexyl acrylate, 28 parts by mass of vinyl acetate, 2 parts by mass of acrylic acid, 100 parts by mass of ethyl acetate and 0.5 parts by mass of 2,2′-azobisisobutyronitrile as a polymerization initiator were charged, and the air in the reaction vessel was replaced with nitrogen gas. While stirring in this nitrogen atmosphere, the reaction solution was heated to 80 ° C., reacted for 8 hours, and then cooled to room temperature to obtain an acrylic acid ester copolymer solution. Here, a molecular weight of a part of the obtained solution was measured by a method described later, and production of an acrylate copolymer having a weight average molecular weight (Mw) of 800,000 was confirmed.

  An aluminum chelate crosslinking agent (manufactured by Toyo Ink Co., Ltd., product name: BXX4805, solid content concentration: 5% by mass) is added to the obtained acrylic acid ester copolymer solution, and the acrylic acid ester copolymer is solidified. It added so that it might become 1.5 mass parts with respect to 100 mass parts in terms of minutes, and the coating solution of the adhesive was obtained.

  The obtained pressure-sensitive adhesive coating solution was coated on the release agent layer of the release sheet with a knife coater so that the thickness after drying was 25 μm, and then dried at 120 ° C. for 1 minute to obtain a pressure-sensitive adhesive layer. Formed. Next, a polyethylene terephthalate film (manufactured by Toray Industries Inc., Lumirror # 50T-60, thickness 50 μm) was superposed on the pressure-sensitive adhesive layer, applied with a load of 19.6 N, and reciprocated with a roller to bond them together. Thereafter, the film was left for 7 days under the conditions of a temperature of 23 ° C. and a relative humidity of 50% RH to obtain an adhesive sheet.

[Example 2]
In the coating solution for the release agent layer, the release sheet and the pressure-sensitive adhesive sheet were prepared in the same manner as in Example 1 except that the release agent layer was formed by changing the blending amount of the crosslinking agent (methylated melamine resin) to 30 parts by mass. Manufactured.

Example 3
A release sheet and an adhesive sheet were produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 50 nm.

Example 4
100 parts by mass of a perfluoropolyether compound having ethoxy alcohol as a functional group (manufactured by Solvay Solexis, product name: FLUOLOLLINK E10H, weight average molecular weight: 1500, solid content concentration: 100% by mass) and methylation as a crosslinking agent 15 parts by mass of melamine resin (Nippon Cytec Industries, product name: Cymel 303, solid content concentration: 100% by mass) and 2 masses of methanol solution of p-toluenesulfonic acid (solid content concentration: 50% by mass) as a catalyst And diluted with a fluorine solvent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: FS thinner) so that the solid content concentration is about 1% by mass, and this was used as a coating solution for the release agent layer. .

  A release sheet and a pressure-sensitive adhesive sheet were produced in the same manner as in Example 1 except that the release agent layer was formed using the coating solution for the release agent layer.

Example 5
In the coating solution for the release agent layer, a release sheet and an adhesive sheet were produced in the same manner as in Example 1 except that the release agent layer was formed without blending the catalyst (p-toluenesulfonic acid).

Example 6
A release sheet and an adhesive sheet were produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 7 nm.

Example 7
A release sheet and an adhesive sheet were produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 1100 nm (1.1 μm).

Example 8
In the coating solution for the release agent layer, the release sheet and the adhesive were the same as in Example 1 except that the release agent layer was formed by changing the blending amount of the crosslinking agent (methylated melamine resin) to 0.5 parts by mass. A sheet was produced.

[Comparative Example 1]
A coating solution for the release agent layer was prepared in the same manner as in Example 1 except that no crosslinking agent (methylated melamine resin) was added. The obtained coating solution was applied to one side of the release substrate in the same manner as in Example 1, and then dried by heating. However, the coating film was not cured and a release agent layer could not be formed. For this reason, it was excluded from the object of the test example mentioned below.

[Comparative Example 2]
In the coating solution for the release agent layer, the crosslinking agent was changed to hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name: Coronate HL, solid content concentration: 75% by mass) (mixing amount was 10 parts by mass), and the release agent. A release sheet and an adhesive sheet were produced in the same manner as in Example 1 except that a layer was formed.

[Comparative Example 3]
100 parts by mass of silicone release agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KS-847H, solid content concentration: 30% by mass) and a curing catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., product name: CAT-PL-50T, solid) (Minute concentration: 2% by mass) was mixed with 1 part by mass and diluted with toluene so that the solid content concentration was about 1% by mass, and this was used as a coating solution for the release agent layer.

  The obtained coating solution is uniformly applied to a single side of a polyethylene terephthalate film (Toray Co., Ltd., Lumirror # 50T-60, thickness 50 μm) as a peeling substrate with a Meyer bar so that the film thickness after drying becomes 100 nm. After coating, the release agent layer was cured by drying at 100 ° C. for 30 seconds. In this way, a release sheet having a release agent layer formed on the release substrate was obtained. Moreover, the adhesive sheet was manufactured like Example 1 except using the said peeling sheet.

[Comparative Example 4]
50 parts by mass of an olefin-based thermoplastic elastomer containing an ethylene propylene copolymer (Mitsui Chemicals, product name: Tafmer P-0280G, density: 0.87 g / cm ³ ) and polyethylene resin (manufactured by Sumitomo Chemical Co., Ltd., linear low) Polyethylene terephthalate film as a peeling base material (Made by Toray, Lumirror # 50T-60, thickness 50 μm) with a mixture of 50 parts by mass of density polyethylene, product name: HI-αCW2004, density: 0.908 g / cm ³ ) A release sheet having a thickness of 20 μm was formed by extrusion lamination on one side of the film to obtain a release sheet.

  On the release agent layer of the obtained release sheet, an adhesive coating solution was applied with a knife coater in the same manner as in Example 1, and then dried at 120 ° C. for 1 minute. As a result, the release agent layer melted. For this reason, it was excluded from the object of the test example mentioned below.

  Here, the above-mentioned weight average molecular weight (Mw) is a polystyrene-reduced weight average molecular weight measured using gel permeation chromatography (GPC).

[Test Example 1] (Measurement of peel force)
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into 150 mm × 50 mm, and the release sheet side was bonded to a stainless steel plate using a double-sided pressure-sensitive adhesive tape. -4-100). Under the conditions of a temperature of 23 ° C. and a relative humidity of 50% RH, the force when the adhesive sheet substrate was peeled in the 180 ° direction at a pulling speed of 300 mm / min was measured according to ISO 8510-2: 1990. Was defined as the peel strength (mN / 50 mm). The results are shown in Table 1.

[Test Example 2] (Measurement of silicone content)
After the adhesive sheets produced in Examples and Comparative Examples were cut to 3 mm × 3 mm, the release sheet was peeled off, and the silicone amount (%) on the surface of the exposed adhesive layer was measured by X-ray photoelectron analysis (XPS). Calculated. As a measuring device, Quantara SXM manufactured by ULVAC-PHI was used, and the measurement conditions were as follows.
X-ray: Monochromatic AlKα (100W, 20kV)
Extraction angle: 45 °
Measuring elements: silicon atom (Si), carbon atom (C)

The silicone amount (%) is calculated based on the following formula. The results are shown in Table 1.
Silicone amount (%) = {Si / (Si + C)} × 100

[Test Example 3] (Measurement of residual adhesion rate)
An adhesive tape (manufactured by Nitto Denko Corporation, trade name: polyester adhesive tape 31B) was bonded to the release agent layer of the release sheet produced in the examples and comparative examples, and a load of 20 g / cm ² was applied at 70 ° C. for 24 hours. Aging was performed. Thereafter, the adhesive tape was peeled off from the release sheet and attached to the stainless steel plate. The pressure-sensitive adhesive tape was peeled off from the stainless steel plate at an angle of 180 ° and a speed of 300 mm / min, and the resistance (the resistance A) was measured.

  On the other hand, an adhesive tape (made by Nitto Denko Corporation, product name: polyester adhesive tape 31B) that is not bonded to the release sheet is attached to the stainless steel plate and peeled off from the stainless steel plate in the same manner as described above. Resistance force B) was measured.

From the above results, the residual adhesion rate (%) was calculated by the following formula.
Residual adhesion rate = (resistance A / resistance B) × 100
Based on the calculated residual adhesion rate, evaluation was performed according to the following criteria. The results are shown in Table 1.
○ (Good): Residual adhesion rate 70% or more △ (Available): Residual adhesion rate 50% or more and less than 70% × (Unusable): Residual adhesion rate less than 50%

  From the above results, the release sheet produced in the example was capable of transfer coating of an adhesive. Further, as is clear from Table 1, the release sheets and pressure-sensitive adhesive sheets produced in the examples had low peel strength, no silicone transfer to the pressure-sensitive adhesive layer, and high residual adhesion rate.

  The pressure-sensitive adhesive sheet of the present invention is suitable as a pressure-sensitive adhesive sheet used for precision electronic devices and the like that require exclusion of silicone compounds. Moreover, the release sheet of the present invention is suitably used as a release sheet for such an adhesive sheet.

DESCRIPTION OF SYMBOLS 1 ... Release sheet 11 ... Release base material 12 ... Release agent layer

Claims (7)

A release sheet comprising a release substrate and a release agent layer formed on at least one surface side of the release substrate,
The release agent layer contains substantially no silicone compound, and the release agent layer contains a perfluoropolyether compound having a hydroxyl group as a functional group and a polyfunctional amino compound as a crosslinking agent. A release sheet, characterized in that it is formed by:   The release sheet according to claim 1, wherein the perfluoropolyether compound has hydroxyl groups at both ends.   The release sheet according to claim 1 or 2, wherein the polyfunctional amino compound is a methylated melamine resin.   4. The release sheet according to claim 1, wherein the content of the polyfunctional amino compound is 1 to 75 parts by mass with respect to 100 parts by mass of the perfluoropolyether compound. .   The weight average molecular weight of the said perfluoropolyether compound is 500-10000, The release sheet as described in any one of Claims 1-4 characterized by the above-mentioned.   The release sheet according to claim 1, wherein the release agent composition further contains p-toluenesulfonic acid as a catalyst. The release sheet according to any one of claims 1 to 6,
A pressure-sensitive adhesive sheet comprising: a pressure-sensitive adhesive layer provided in contact with the release agent layer of the release sheet.

Images