JP7198508B2 - release sheet - Google Patents

Description

The present invention relates to a release sheet.

Release sheets are laminated to the adhesive layer of adhesive sheets to protect the adhesive layer surface of adhesive sheets used in various applications, including the manufacturing process of electronic parts such as semiconductor devices and precision equipment. is used in
A resin layer containing a release agent is provided on the surface of the base material that constitutes the release sheet so that the release sheet can be easily peeled off from the pressure-sensitive adhesive sheet. Silicone-based release agents are most commonly used as release agents for release sheets. However, when a silicone-based release agent is used, a low-molecular-weight silicone compound contained in the silicone-based release agent may migrate to the surface of the adhesive layer of the adhesive sheet and remain there. The silicone compound remaining on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet not only causes a decrease in the adhesive strength of the pressure-sensitive adhesive, but also gradually evaporates and, for example, deposits on the surface of the electronic component on which the pressure-sensitive adhesive sheet is used. , has been pointed out to adversely affect its performance.

As a non-silicone release agent for a release sheet, Patent Document 1 proposes the use of a polypropylene-based acid-modified polyolefin, Patent Document 2 proposes the use of a polyethylene-based acid-modified polyolefin, and Patent Document 3. , 4 propose the use of acid-modified α-olefin/ethylene copolymers.
The release sheets of Patent Documents 1 and 2 exhibit good releasability with respect to the pressure-sensitive adhesive sheet. However, since these release sheets have low heat resistance, they adhere strongly to the pressure-sensitive adhesive sheet when stored at high temperature in a state where they are bonded to the pressure-sensitive adhesive sheet, which may reduce handling properties. , the release agent component migrates to the pressure-sensitive adhesive sheet, and the peeled pressure-sensitive adhesive sheet may have reduced adhesiveness. In particular, if heat is applied during drying after application of the adhesive or during transfer of the adhesive sheet, the releasability of the release sheet tends to change, which is not preferable in terms of handling.
The release sheets of Patent Documents 3 and 4 have excellent releasability from the adhesive sheet and excellent heat resistance, and solve the problems of the release sheets of Patent Documents 1 and 2. However, the release sheet of Patent Document 3 is formed by applying an organic solvent solution substantially to form a release layer, and there was a problem in the work environment during production. Further, in the release sheets of Patent Documents 3 and 4, the coefficient of dynamic friction of the resin layer is large, and in the roll-to-roll continuous production process, when winding around the core to produce a roll-shaped laminate, Wrinkles, creases, unevenness, etc. occur in the release sheet, resulting in a decrease in the yield of the release sheet, resulting in a decrease in economic efficiency. For this reason, there has been a demand for a release sheet that not only has excellent releasability but also has a reduced coefficient of dynamic friction.

WO2014/109341 WO2014/109340 WO2015/064599 JP 2016-203570 A

In view of these problems, the problem of the present invention is to provide a resin layer that has excellent releasability from the adhesive material, excellent heat resistance, and a low dynamic friction coefficient, and is suitable for continuous roll-to-roll production. It is another object of the present invention to provide a release sheet having the same properties as above, and to provide a method for forming a resin layer with a water-based coating liquid.

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by forming a resin layer having a specific composition on a substrate, and have completed the present invention.
That is, the gist of the present invention is as follows.

(1) A release sheet comprising a base material and a resin layer provided thereon,
one or more polymers constituting the resin layer contain, as copolymer components, an olefin component, an unsaturated carboxylic acid component and a (meth)acrylic acid ester component ,
the olefin component contains an α-olefin component and an ethylene component,
The mass ratio of the α-olefin component and the ethylene component (α-olefin component/ethylene component) is 10/90 to 60/40 in the resin layer,
The content of the (meth)acrylic acid ester component in the resin layer is 0.1 to 15% by mass,
The dynamic friction coefficient when the resin layer surface and the base material surface are superimposed is 0.45 or less,
A sample obtained by attaching the adhesive layer of a resin tape having an acrylic adhesive layer to the resin layer surface of a release sheet was subjected to a peeling angle of 180 degrees and a peeling speed of 300 mm / min at 25 ° C. A release sheet, wherein the peel strength between the pressure-sensitive adhesive layer and the resin layer is 0.5 N/cm or less when measured at .
(2 ) The release sheet according to (1 ), wherein the content of the unsaturated carboxylic acid component in the resin layer is 0.1 to 15% by mass.
( 3 ) The resin layer contains a cross-linking agent comprising an oxazoline compound and/or a carbodiimide compound, and the content of the cross-linking agent in the resin layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the polymer. The release sheet according to (1) or (2) , characterized by:
( 4 ) The resin layer contains polyvinyl alcohol, and the content of polyvinyl alcohol in the resin layer is 0.1 to 1000 parts by mass with respect to 100 parts by mass of the polymer (1)- ( 3 ) The release sheet according to any one of (3).
( 5 ) The release sheet according to ( 4 ), wherein the degree of saponification of polyvinyl alcohol is 99 mol% or less.
( 6 ) A method for producing the release sheet according to (1) above,
A polymer (A) comprising an acid-modified α-olefin/ethylene copolymer, a polymer (B) comprising an acid-modified polyethylene resin containing a (meth)acrylic acid ester component as a copolymer component, and an aqueous medium. A method for producing a release sheet, which comprises coating a base material with a coalesced liquid material to form a resin layer.
( 7 ) The mass ratio of the α-olefin component to the ethylene component (α-olefin component/ethylene component) in the polymer (A) comprising an acid-modified α-olefin/ethylene copolymer is 40/60 to 80/20 ( However, 40/60 is excluded).

By using the release sheet of the present invention, it is possible to protect the surface of the adhesive layer of the adhesive material, and since the release sheet of the present invention has excellent heat resistance, after being attached to the adhesive material or the like, after heat treatment Excellent releasability. Moreover, even when the release sheet of the present invention is attached to an adhesive material and stored at a high temperature, the resin layer components hardly migrate to the adhesive material, and the peeled adhesive material can maintain a high residual adhesion rate. Furthermore, the release sheet of the present invention has a resin layer with a small coefficient of dynamic friction, and when wound around a core to produce a roll-shaped laminate, the release sheet is less prone to wrinkles, folds, irregularities, etc. The yield of mold sheets can be improved.
The release sheet of the present invention can form a resin layer having releasability on a base material by using a water-based coating agent, and can be produced by solving the problem of the working environment due to the use of organic solvents. can be done.

The present invention will be described in detail below.
The release sheet of the present invention comprises a substrate and a resin layer provided thereon. The resin layer contains one or more polymers containing an olefin component and an unsaturated carboxylic acid component as copolymer components.

<Polymer>
In the present invention, the olefin component constituting the polymer must contain an α-olefin component and an ethylene component.
Examples of α-olefin components include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene and 1-undecene. , 1-dodecene and the like. Among these, propylene and 1-butene are preferred, and propylene is more preferred, from the viewpoint of economy and availability. Two or more of these α-olefin components may be contained in the polymer.

The mass ratio of the α-olefin component to the ethylene component (α-olefin component/ethylene component) in the resin layer must be 10/90 to 60/40, and is 15/85 to 50/50. is preferred, and 20/80 to 40/60 is more preferred.
When the mass ratio of the α-olefin component and the ethylene component in the resin layer is within the above range, the release sheet has excellent releasability and excellent heat resistance. If the mass ratio of the α-olefin component and the ethylene component is outside the above range, the release sheet tends to have low releasability and poor heat resistance. The tacky material after holding at may have a lower residual adhesion rate.

In the present invention, the polymer must contain an unsaturated carboxylic acid component as a copolymerization component.
Examples of unsaturated carboxylic acid components include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, etc., as well as half esters and half amides of unsaturated dicarboxylic acids. is mentioned. Among them, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferable, in order to stably disperse the polymer in the aqueous dispersion of the polymer described later. . Two or more of these unsaturated carboxylic acid components may be contained in the polymer. The unsaturated carboxylic acid component may be copolymerized in the polymer, and its form is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization.

The content of the unsaturated carboxylic acid component in the polymer is preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass, and 0.8 to 10% by mass. is more preferable, and 1.5 to 7% by mass is particularly preferable. If the content of the unsaturated carboxylic acid component is less than 0.5% by mass, the reaction with the cross-linking agent may be insufficient, resulting in inferior heat resistance of the resin layer. On the other hand, when it exceeds 20% by mass, the resulting release sheet tends to have lower blocking resistance and lower releasability.

The content of the unsaturated carboxylic acid component in the resin layer containing a crosslinking agent, polyvinyl alcohol, etc., which will be described later, is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass. , more preferably 1 to 7% by mass, particularly preferably 1.5 to 5% by mass. If the content of the unsaturated carboxylic acid component is less than 0.1% by mass, the resulting resin layer tends to have poor adhesion to the substrate. If it exceeds 15% by mass, the resulting release sheet tends to have lower blocking resistance and lower releasability.

In the present invention, the polymer preferably contains a (meth)acrylate component as a copolymer component.
Examples of the (meth)acrylic acid ester component include esters of (meth)acrylic acid and alcohols having 1 to 30 carbon atoms. Esters with -20 alcohols are preferred. Specific examples of such compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, and (meth)acrylic acid. octyl, decyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate and the like. Mixtures of these may also be used. The term "(meth)acrylic acid" means "acrylic acid or methacrylic acid".

The content of the (meth)acrylate component in the polymer is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and 1.5 to 15% by mass. is more preferable, and 2 to 10% by mass is particularly preferable. If the content of the (meth)acrylic acid ester component exceeds 30% by mass, not only is the releasability of the resulting resin layer reduced, but the liquid stability of the polymer-containing liquid is also reduced. There is

The content of the (meth)acrylic acid ester component in the resin layer containing a crosslinking agent, polyvinyl alcohol, etc., which will be described later, is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass. It is more preferably 1 to 7% by mass, and particularly preferably 1.5 to 5% by mass. If the content of the (meth)acrylic acid ester component in the resin layer is outside the preferred range, the coefficient of dynamic friction tends to increase.

In the present invention, the resin layer contains a polymer containing the above copolymer component, but may contain a polymer other than the above.
When the resin layer contains two or more types of polymers, each polymer has the above-described mass ratio between the α-olefin component and the ethylene component, the content of the unsaturated carboxylic acid component, and (meth)acrylic acid. It is not necessary to satisfy the content of the ester component, and the mass ratio of the α-olefin component and the ethylene component, the content of the unsaturated carboxylic acid component, the content of the (meth)acrylic acid ester component in the polymer as a whole and the resin layer The content may be satisfied, and the resin layer may contain a polymer that does not contain the copolymerization component.

Although the type of polymer is not limited, polyolefin resins are preferred from the viewpoints of ease of handling and availability. Specific examples of polyolefin resins include ethylene homopolymers such as low-, medium-, and high-density polyethylene (branched or linear), ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-4-methyl -1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl alcohol copolymer (including saponified ethylene-vinyl acetate copolymer), ethylene-( meth) Ethylene-based resins such as acrylic acid copolymer; propylene-based resins such as propylene homopolymer, propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer; 1-butene homopolymer, 1- 1-butene resins such as butene-ethylene copolymers and 1-butene-propylene copolymers; so-called cyclic polyolefin resins such as norbornene ring-opening metathesis polymers and norbornene derivatives-ethylene copolymers; ethylene-propylene- Butene-maleic anhydride copolymer, ethylene-(meth)acrylic acid ester-maleic anhydride copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-maleic anhydride copolymer, propylene-maleic anhydride acid-modified polyolefin resins such as copolymers, ethylene-propylene-maleic anhydride copolymers, ethylene-butene-maleic anhydride copolymers, and propylene-butene-maleic anhydride copolymers;

The method of polymerizing the polyolefin resin is not limited, but specific examples include a high pressure method, a slurry method, a solution method, a gas phase method and the like. The polymerization catalyst is also not particularly limited, and may be a Ziegler catalyst, a metallocene catalyst, or the like.

In the present invention, the polymer constituting the resin layer preferably has a number average molecular weight of 3,000 to 15,000. When the resin layer contains a polymer having a number average molecular weight within the above range, the releasability may be improved.

The resin layer in the present invention preferably comprises a polymer (A) comprising an acid-modified α-olefin/ethylene copolymer and a polymer (B) comprising an acid-modified polyethylene resin. When two or more kinds of polymers are contained in this way, not only is it preferable from the viewpoint of the coefficient of dynamic friction, but even when the resin layer is thickened, the surface of the adherend is less likely to be contaminated by the release sheet.

<Polymer (A) composed of acid-modified α-olefin/ethylene copolymer>
The polymer (A) composed of an acid-modified α-olefin/ethylene copolymer is an acid-modified α-olefin/ethylene copolymer, and the α-olefin/ethylene copolymer contains one or more α - contains an olefin component and an ethylene component;
Examples of α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like. Among these, propylene and 1-butene are preferred from the viewpoint of economy and availability.

The mass ratio of the α-olefin component to the ethylene component (α-olefin/ethylene) in the α-olefin/ethylene copolymer constituting the polymer (A) is 40/60 to 80/20 (however, 40/60 is except) is preferred. That is, the mass of α-olefin with respect to the total mass of α-olefin and ethylene is more than 40% by mass, preferably 80% by mass or less, more preferably more than 50% by mass, and 51% by mass or more. is more preferably 70% by mass or less, and even more preferably 65% by mass or less.
By setting the mass ratio of the α-olefin component to the ethylene component in the α-olefin/ethylene copolymer constituting the polymer (A) within the above range, a mold release provided with a resin layer containing the polymer (A). Even if the sheet is exposed to a high temperature for a long time with the adherend attached thereto, the surface of the adherend is less likely to be contaminated.

The α-olefin/ethylene copolymer constituting the polymer (A) preferably has a number average molecular weight of 500 to 25,000, more preferably 700 to 20,000, more preferably 1,000 to 17 ,000 is more preferred. By acid-modifying the α-olefin/ethylene copolymer having the number average molecular weight within the above range, the number average molecular weight of the polymer (A) can be adjusted to the range described below.

The α-olefin/ethylene copolymer constituting the polymer (A) is preferably produced using a metallocene catalyst. The α-olefin/ethylene copolymer produced by this method has a narrow molecular weight distribution, a small amount of low molecular weight components, and uniform copolymerization.

The content of the acid-modified component constituting the polymer (A) is preferably 0.5% by mass or more, more preferably 0.5 to 20% by mass, and more preferably 0.5 to 10% by mass. more preferably 1 to 10% by mass, most preferably 1.5 to 10% by mass. When the content of the acid-modified component is less than 0.5% by mass, the polymer (A) may be difficult to disperse in an aqueous medium by the method described later, and the obtained resin layer may The adhesiveness of the resin may become insufficient, or the reaction with the cross-linking agent may become insufficient, resulting in poor heat resistance.

Acid modification of the α-olefin/ethylene copolymer can be carried out, for example, by introducing an unsaturated carboxylic acid component into the α-olefin/ethylene copolymer.
Specific examples of the unsaturated carboxylic acid component introduced into the α-olefin/ethylene copolymer include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like. Other examples include half esters and half amides of unsaturated dicarboxylic acids. Among them, maleic anhydride, acrylic acid and methacrylic acid are preferred, and maleic anhydride is more preferred, from the viewpoint of ease of introduction into the α-olefin/ethylene copolymer. Two or more of these unsaturated carboxylic acid components may be contained in the polymer.
The unsaturated carboxylic acid component may be copolymerized in the α-olefin/ethylene copolymer, and its form is not limited. Examples thereof include random copolymerization, block copolymerization, and graft copolymerization. be done.

The number average molecular weight of the polymer (A) is preferably 1,000 to 30,000, more preferably 1,200 to 25,000, and further preferably 1,500 to 20,000. preferable. When the number average molecular weight of the polymer (A) is within the above range, it is possible to produce an aqueous dispersion that is uniform and has a good dispersion state.

A commercially available α-olefin/ethylene copolymer can be used as the α-olefin/ethylene copolymer for acid modification. Commercially available α-olefin/ethylene copolymers include Lucanto series LX020, LX100, LX200, LX400 manufactured by Mitsui Chemicals. Polymer (A) can be obtained by acid-modifying such a commercially available α-olefin/ethylene copolymer.
A commercially available polymer (A) may also be used. Examples of the commercially available polymer (A) include A-5515, A-5260 and A-5320H of Lucanto series manufactured by Mitsui Chemicals.

<Polymer (B) made of acid-modified polyethylene resin>
The polymer (A) composed of the acid-modified α-olefin/ethylene copolymer and the polymer (B) composed of the acid-modified polyethylene resin constituting the resin layer are acid-modified polyethylene resins.

The olefin component constituting the polymer (B) is ethylene, and other than ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-hexene, 4-methyl-1-pentene, etc. having 2 to 6 carbon atoms. However, the content of olefin components other than ethylene is preferably 20% by mass or less with respect to the total mass of olefin components.

The content of the acid-modified component constituting the polymer (B) is preferably 0.1% by mass or more, more preferably 0.1 to 30% by mass, and more preferably 0.5 to 15% by mass. more preferably 1 to 10% by mass. When the content of the acid-modified component is less than 0.1% by mass, the polymer (B) may be difficult to disperse in an aqueous medium by the method described later, and the resulting resin layer may may be poor in adhesion.

Acid modification of the polymer (B) can also be carried out by introducing an unsaturated carboxylic acid or its anhydride into the polyethylene resin.
Specific examples of the unsaturated carboxylic acid component introduced into the polyethylene resin include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and unsaturated dicarboxylic acid. and half esters and half amides of Among them, maleic anhydride, acrylic acid, and methacrylic acid are preferred, and maleic anhydride is more preferred, from the viewpoint of ease of introduction into the polyethylene resin. Two or more of these unsaturated carboxylic acid components may be contained in the polymer.
The unsaturated carboxylic acid component may be copolymerized in the polyethylene resin, and its form is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization.

In the present invention, the polymer (B) preferably contains a (meth)acrylate component as a copolymerization component.
Examples of the (meth)acrylic acid ester component include esters of (meth)acrylic acid and alcohols having 1 to 30 carbon atoms. Esters with -20 alcohols are preferred. Specific examples of such compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, and (meth)acrylic acid. octyl, decyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate and the like. Mixtures of these may also be used.

The content of the (meth)acrylate component in the polymer (B) is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and 1.5 to 20% by mass. is more preferable, and 2 to 15% by mass is particularly preferable. When the content of the (meth)acrylic acid ester component is less than 0.5% by mass, the resin layer containing the polymer (B) loses its peel strength over time when left with the adhesive material attached. tend to increase exponentially. On the other hand, when it exceeds 40% by mass, when an aqueous dispersion of the polymer (B) is produced by the method described later, the dispersion may have reduced liquid stability.

The polymer (B) is most preferably a terpolymer composed of ethylene, methyl or ethyl acrylate, and maleic anhydride.

The polymer (B) has a melt flow rate of 0.01 to 500 g/10 minutes, preferably 0.1 to 300 g/10 minutes, more preferably 0.1 to 250 g/10 min, more preferably 0.5 to 200 g/10 min, and most preferably 1 to 100 g/10 min can be used. If the melt flow rate of polymer (B) is less than 0.01 g/10 minutes, it becomes difficult to disperse polymer (B) in water by the method described below. On the other hand, when the melt flow rate of the polymer (B) exceeds 500 g/10 minutes, the release sheet provided with the resin layer containing the polymer (B) can When exposed to for a long time, the surface of the adherend is likely to be contaminated.

The method for synthesizing the polymer (B) in the present invention is not particularly limited. For example, the polymer (B) can be obtained by high-pressure radical copolymerization of monomers constituting the polymer (B) in the presence of a radical generator. Also, the unsaturated carboxylic acid may be graft-copolymerized.

<Crosslinking agent>
In the present invention, the resin layer of the release sheet preferably contains a cross-linking agent. By containing a cross-linking agent, the constituent components of the resin layer are cross-linked, and various performances such as releasability, cohesion, and water resistance of the resin layer can be improved. As the cross-linking agent, a compound having a plurality of functional groups in the molecule that react with the unsaturated carboxylic acid component constituting the polymer is used, and examples include oxazoline compounds, carbodiimide compounds, epoxy compounds, isocyanate compounds, and the like. From the viewpoint of reactivity, it is preferably at least one cross-linking agent selected from oxazoline compounds and carbodiimide compounds.

The oxazoline compound is not particularly limited as long as it has two or more oxazoline groups in its molecule. For example, 2,2'-bis(2-oxazoline), 2,2'-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis(2-oxazoline) , compounds having an oxazoline group such as bis(2-oxazolinylcyclohexane)sulfide, and oxazoline group-containing polymers. These 1 type(s) or 2 or more types can be used. Among these, an oxazoline group-containing polymer is preferable because of ease of handling.
Oxazoline group-containing polymers are obtained by polymerizing addition-polymerizable oxazolines such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline and 2-isopropenyl-2-oxazoline. Other monomers may be copolymerized as necessary. The polymerization method of the oxazoline group-containing polymer is not particularly limited, and various known polymerization methods can be employed.
Examples of commercially available oxazoline group-containing polymers include Epocross series manufactured by Nippon Shokubai Co., Ltd. Specifically, water-soluble types "WS-500" and "WS-700", solid type "RPS-1005". and so on.

The carbodiimide compound is not particularly limited as long as it has at least two carbodiimide groups in its molecule. For example, compounds having a carbodiimide group such as p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), cyclohexane-1,4-bis(methylene-t-butylcarbodiimide) and polycarbodiimide, which is a polymer having carbodiimide groups. These 1 type(s) or 2 or more types can be used. Among these, polycarbodiimide is preferred because of ease of handling.
The method for producing polycarbodiimide is not particularly limited. Polycarbodiimide can be produced, for example, by a condensation reaction accompanied by decarbonation of an isocyanate compound. The isocyanate compound is also not limited, and may be any of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate. The isocyanate compound may be copolymerized with polyfunctional liquid rubber, polyalkylenediol, or the like, if necessary.
Commercially available products of polycarbodiimide include the Carbodilite series manufactured by Nisshinbo. V-04", emulsion type "E-02", "E-03A", "E-04", organic solution type "V-01", "V-03", "V-07", "V-09", non-solvent type "V-05", and the like.

The content of the cross-linking agent comprising an oxazoline compound and/or a carbodiimide compound in the resin layer is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 40 parts by mass, with respect to 100 parts by mass of the polymer. more preferably 1 to 30 parts by mass, particularly preferably 2 to 20 parts by mass. If the content of the cross-linking agent is less than 0.1 parts by mass with respect to 100 parts by mass of the polymer, the effect of the addition is poor, and the resulting resin layer may deteriorate in releasability over time or lack sufficient heat resistance. If the content exceeds 50 parts by mass with respect to 100 parts by mass of the polymer, the flexibility of the resin layer may be impaired and the peel strength may increase. As the cross-linking agent, the oxazoline compound and the carbodiimide compound can be used at the same time.

The epoxy compound is not particularly limited, and for example, epoxy compounds containing bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, etc. may be used. can be done.
Commercially available epoxy compounds include Denacol series (EM-150, EM-101, etc.) manufactured by Nagase Chemtech, and ADEKA RESIN EM-0517, EM-0526, EM-11-50B, and EM-051R manufactured by Adeka. , SR-GSG and SR-4GSL manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., and the like.

The isocyanate compound is not particularly limited as long as it has at least two isocyanate groups in its molecule. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane 2,4'- or 4,4'-diisocyanate, polymethylene polyphenyl diisocyanate, tolidine diisocyanate, 1,4-diisocyanatobutane, hexamethylene diisocyanate, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- or 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 4,4′-diisocyanatodicyclohexylmethane, hexahydrotoluene 2, 4- or 2,6-diisocyanate, perhydro-2,4'- or 4,4'-diphenylmethane diisocyanate, naphthalene 1,5-diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, tetra Examples include diisocyanates such as methylxylylene diisocyanate and derivatives thereof. Among the isocyanate compounds, aqueous (water-soluble or water-dispersible) ones are preferred.
Examples of commercially available isocyanate compounds include Bayhydur 3100 manufactured by Sumika Bayer Urethane Co., Ltd., Desmodur DN, and Vasonate HW-100 manufactured by BASF.

<Polyvinyl alcohol>
In the present invention, the resin layer of the release sheet may contain polyvinyl alcohol. By dispersing polyvinyl alcohol in the resin layer, it is possible to suppress the increase in peel strength over time, and to exhibit the adhesiveness to the substrate that polyvinyl alcohol itself has.

The type of polyvinyl alcohol is not particularly limited, but examples thereof include those obtained by completely or partially saponifying a vinyl ester polymer. The degree of saponification of polyvinyl alcohol is not particularly limited, and may be, for example, 70 mol % or more, but from the viewpoint of operability in the continuous manufacturing process of the release sheet, it is preferably 99 mol % or less. , 97 mol % or less.
The average degree of polymerization of polyvinyl alcohol is not particularly limited, and may be, for example, 100 or more, but from the viewpoint of operability in the continuous manufacturing process of the release sheet, it is preferably 5,000 or less. , 1,500 or less.
When the degree of saponification of polyvinyl alcohol exceeds 99 mol % or the average degree of polymerization exceeds 5,000, gel may occur in the liquid material for forming the resin layer. When the release sheet is continuously produced by circulating the liquid material and applying it to the base material, the gel generated in the liquid material may accumulate in the circulation system, resulting in deterioration of the continuous operation.

Polyvinyl alcohol is preferably water-soluble for use as a liquid as described below.

The content of polyvinyl alcohol in the resin layer is preferably 0.1 parts by mass or more, and 0.5 parts by mass or more with respect to 100 parts by mass of the polymer, from the viewpoint of suppressing the increase in peel strength over time. and more preferably 1 part by mass or more. On the other hand, the content of polyvinyl alcohol in the resin layer is preferably 1,000 parts by mass or less and 500 parts by mass or less with respect to 100 parts by mass of the polymer, from the viewpoint of releasability of the resin layer. is more preferably 300 parts by mass or less. In order to satisfy both of these points of view, the content of polyvinyl alcohol in the resin layer is preferably 0.1 to 1000 parts by mass, and 0.5 to 500 parts by mass with respect to 100 parts by mass of the polymer. more preferably 1 to 300 parts by mass.
In addition, the content of polyvinyl alcohol in the resin layer is preferably less than 10 parts by mass or 500 parts by mass or more with respect to 100 parts by mass of the polymer, from the viewpoint of improving transparency (reducing haze). It is more preferably less than or equal to 1000 parts by mass, and more preferably zero. On the other hand, the content of polyvinyl alcohol is preferably 10 parts by mass or more and less than 500 parts by mass from the viewpoint of improving visibility (increasing haze) to prevent forgetting to remove the release sheet during the process. It is more preferably 100 parts by mass or more and 400 parts by mass or less.

Examples of commercial products of polyvinyl alcohol include "JC-05", "VC-10", "JT-05", "JF-05", and "ASC" of "J-Poval" manufactured by Japan Vinyl Acetate & Poval Co., Ltd. -05X", "UMR-10HH"; "PVA-103" and "PVA-105" of "Kuraray Poval" manufactured by Kuraray Co., Ltd., and "AQ4104" and "HR3010" of "Exeval" manufactured by Denki Kagaku Kogyo Co., Ltd. Examples include "PC-1000" and "PC-2000" of "Denka Poval".

In the present invention, the resin layer of the release sheet may contain a lubricant as long as the effects of the present invention are not impaired. Examples of lubricants include inorganic substances such as calcium carbonate, magnesium carbonate, calcium oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, tin oxide, antimony trioxide, and molybdenum disulfide. Examples include particles, organic particles such as acrylic crosslinked polymers, styrene crosslinked polymers, silicone resins, fluororesins, benzoguanamine resins, phenolic resins, nylon resins, and polyethylene wax, and surfactants. Various chemicals such as antioxidants, antistatic agents and ultraviolet absorbers, and pigments or dyes such as titanium oxide, carbon black and zinc oxide may also be added as necessary.

<Resin layer>
The release sheet of the present invention must have a dynamic friction coefficient of 0.50 or less when measured by superimposing the resin layer surface of the release sheet and the substrate surface of another release sheet. It is preferably 0.45 or less, more preferably 0.40 or less. If the coefficient of dynamic friction exceeds 0.50, slippage between the resin layer surface and the base material surface is low when the release sheet is wound around the core, so winding deviation is likely to occur, and the release sheet may be wrinkled, folded, or uneven. etc. may occur, resulting in a decrease in the yield of the release sheet, as well as a decrease in the scratch resistance of the resin layer, which may affect the surface shape of the adherend after peeling. The dynamic friction coefficient can be controlled by the material forming the resin layer, and the resin layer may contain two or more types of polymers, or the content of the (meth)acrylic acid ester component in the resin layer is within a preferable range. When it is within the range, the coefficient of dynamic friction tends to decrease.

In the release sheet of the present invention, a sample obtained by attaching the adhesive layer of a resin tape having an acrylic adhesive layer to the surface of the resin layer of the release sheet was held at a peel angle of 180 at 25 ° C. The peel strength between the pressure-sensitive adhesive layer and the resin layer when measured at a peel rate of 300 mm/min is required to be 0.5 N/cm or less, and preferably 0.3 N/cm or less. It is preferably 0.2 N/cm or less, more preferably 0.15 N/cm or less. If the peel strength to the acrylic adhesive material exceeds 0.5 N/cm, resistance is felt when the release sheet is peeled from the adhesive material, and the adhesive material has a rough surface, resulting in a decrease in adhesiveness. Therefore, it may be difficult to use it as a release sheet for acrylic pressure-sensitive adhesive materials.
The release sheet of the present invention can also be used for silicone-based adhesive materials, which are typical adhesive materials with strong adhesive strength. When a conventional silicone-based release sheet is used for a silicone-based pressure-sensitive adhesive material, the affinity between the pressure-sensitive adhesive layer and the release layer is high, resulting in increased adhesion and difficulty in peeling. On the other hand, the release sheet of the present invention can maintain good releasability even from silicone adhesive materials.
Since the release sheet of the present invention has excellent heat resistance, the peel strength changes over time even if the adhesive material to which the release sheet is attached is exposed to high temperatures for a long time during the process of storage and distribution. In addition, even after a long period of time has passed since the adhesion, the change in the peel strength between the resin layer and the adhesive material can be kept small.
In addition, in the process of peeling off the release sheet industrially, as the work line speeds up, the release sheet is generally peeled off at a speed exceeding 10m/min, so high-speed peeling from the adhesive material is possible. A release sheet is required. Since the release sheet of the present invention has sufficient releasability, even if it is peeled off from the adhesive material at high speed, it can be peeled off without any noise or resistance. That is, when the release sheet of the present invention is peeled at high speed, it is possible to suppress deterioration in transparency and adhesiveness caused by roughening of the surface of the adhesive material caused by a phenomenon called zipping or stick-slip. .

The haze (Hz) of the release sheet of the present invention is preferably 3.5% or more, and preferably 4.5%, from the viewpoint of visibility in order to prevent the release sheet from being forgotten to be peeled off during the process. It is more preferably 5.5% or more, more preferably 5.5% or more. On the other hand, from the viewpoint of irradiation efficiency when a release sheet is coated with a photosensitive resin or the like and light is irradiated from the release sheet, the haze is preferably less than 3.5%, more preferably 3.0%. It is more preferably 2.8% or less, more preferably 2.8% or less.
The haze of the release sheet of the present invention can be adjusted by selecting the type and thickness of the base material and the constituent components and thickness of the resin layer, particularly by adjusting the content of polyvinyl alcohol in the resin layer. can do.

In the present invention, the resin layer of the release sheet is preferably flexible. The flexibility of the resin layer tends to improve the releasability of the release sheet.
The index of flexibility is not particularly limited, for example, storage modulus, loss modulus, Vickers hardness, Martens hardness, Rockwell hardness, Shore hardness, Knoop hardness, pencil hardness, nanoindentation method Hardness measured by

<Base material>
Examples of the substrate constituting the release sheet of the present invention include those formed of resin materials, paper, synthetic paper, cloth, metal materials, glass materials, and the like. Although the thickness of the substrate is not particularly limited, it is usually 1 to 1000 μm, preferably 1 to 500 μm, more preferably 10 to 200 μm, particularly preferably 25 to 100 μm.

Examples of resin materials that can be used for the base material include thermoplastic resins such as polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA); polyolefin resins such as polypropylene; polystyrene resins; Polyamide resins such as nylon 6 and poly-m-xylylene adipamide (MXD6 nylon); polycarbonate resins; polyacrylonitrile resins; polyimide resins; , nylon 6/ethylene-vinyl alcohol copolymer/nylon 6) and mixtures.
The resin material may be stretched. Among them, the substrate is preferably a polyester resin film excellent in mechanical properties and thermal properties, and preferably a polyethylene terephthalate film because it is inexpensive and readily available.

<Manufacturing method>
The release sheet of the present invention is prepared by applying a liquid material containing a polymer containing an olefin component and an unsaturated carboxylic acid component as copolymer components in a liquid medium to a substrate, and applying the liquid material. It can be easily produced industrially by a method of drying, stretching and heat-treating the obtained base material to form a resin layer.

In the present invention, the liquid medium constituting the resin layer-forming liquid is preferably an aqueous medium. The aqueous medium means a solvent containing water and an amphipathic organic solvent and having a water content of 2% by mass or more, and may be water only.
The amphiphilic organic solvent refers to an organic solvent having a water solubility of 5% by mass or more in an organic solvent at 20°C (for the solubility of water in an organic solvent at 20°C, see, for example, "Solvent Handbook" (Kodansha Scientific, 10th Ed. 1990).
Specific examples of amphipathic organic solvents include alcohols such as methanol, ethanol, n-propanol and isopropanol; ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone and methyl ethyl ketone; Esters such as n-propyl, isopropyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, ethylene glycol derivatives such as ethylene glycol-n-butyl ether, diethylamine, triethylamine, diethanolamine, triethanolamine containing ammonia , N,N-dimethylethanolamine and N,N-diethylethanolamine, and lactams such as 2-pyrrolidone and N-methyl-2-pyrrolidone.

The resin layer-forming liquid containing a polymer liquid may contain a cross-linking agent and polyvinyl alcohol.
An aqueous dispersion can be used as the liquid polymer. A method for dispersing the polymer in water is not particularly limited, but includes, for example, the method described in International Publication No. 02/055598.
Regarding the dispersed particle size of the polymer in the aqueous medium, the number average particle size is preferably 1 μm or less, and preferably 0.8 μm or less, from the viewpoint of stability during mixing with other components and storage stability after mixing. is more preferable. Such particle size can be achieved by the process described in WO 02/055598. Incidentally, the number average particle size of the polymer is measured by a dynamic light scattering method.
The solid content concentration of the aqueous dispersion of the polymer is not particularly limited, but is preferably 1 to 60% by mass, more preferably 5 to 30% by mass, in order to keep the viscosity of the aqueous dispersion at an appropriate level. .

The solid content concentration of the resin layer-forming liquid obtained by mixing the polymer liquid with a cross-linking agent or polyvinyl alcohol can be appropriately selected depending on the lamination conditions, desired thickness, performance, etc., and is particularly limited. not a thing However, it is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, in order to keep the viscosity of the liquid substance at an appropriate level and form a uniform resin layer.
Additives such as a leveling agent, an antifoaming agent, an anti-popping agent and a wetting agent can be added to the resin layer-forming liquid as long as the performance of the liquid is not impaired.

In the present invention, the method for applying the resin layer-forming liquid to the substrate includes known methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, and spraying. Coating, dip coating, brush coating and the like can be mentioned.

In the present invention, when the resin layer-forming liquid is applied to the thermoplastic resin film as the base material, the steps of applying the resin layer-forming liquid during the manufacturing process of the base film and drying together with the base film are performed. , orientation stretching and heat setting. By coating during the manufacturing process, the resin layer can be formed in a state in which the degree of oriented crystallization on the surface of the base film is small, so that the adhesion between the base film and the resin layer is improved. In addition, since the resin layer can be heat-treated at a higher temperature while the base film is in tension, the releasability and residual adhesive strength can be improved without degrading the quality of the base film. Furthermore, compared with off-line coating, not only can the manufacturing process be simplified, but also the thinning of the resin layer is advantageous in terms of cost. In the case of adopting the sequential biaxial stretching method, the liquid material is applied to the substrate film stretched in the uniaxial direction, the substrate film coated with the liquid material is dried, and then the substrate film is stretched as described above. Further stretching in the direction perpendicular to the direction and heat treatment are preferred for convenience and operational reasons.

<Application>
The release sheet of the present invention is also suitable for use as a prepreg process material. For example, a solution containing a resin such as an epoxy resin or a phenolic resin and a curing agent is applied and dried to form a sheet. It can be suitably used as a carrier sheet for the occasion.
Since the release sheet of the present invention also has heat resistance, the release property can be maintained even after high-temperature treatment in the curing step. The prepreg may use a reinforcing material such as a woven fabric such as carbon fiber or glass fiber in order to enhance the reinforcing effect. Processes in which prepregs are used include press processes for printed wiring boards, molding processes for structural members such as aircraft, bicycles and windmills, and molding processes for sports and leisure goods such as golf shafts and tennis rackets. Examples of printed wiring boards include single-sided printed wiring boards, double-sided printed wiring boards, flexible printed wiring boards, and multilayer printed wiring boards.

Examples of sheet-like structures that can be produced using the release sheet of the present invention as a base material include rubber sheets such as silicone rubber, fluororubber, and urethane rubber; Ion-exchange membranes made of polymer electrolytes such as fluorosulfonic acid resins, ceramic green sheets made of dielectric ceramics or glass, heat dissipation sheets containing heat dissipation materials and the like can be used.
In these production processes, a sheet-like structure can be formed by coating a raw material made into a paste or slurry with a solvent on the release sheet of the present invention, which serves as a base substrate, and drying the raw material. Alternatively, a sheet-like structure can be formed by extruding a melted resin onto a release sheet.

When the release sheet of the present invention is used for transfer printing, various functional layers such as a printing layer, an electrode, and a protective layer are formed by coating the release sheet of the present invention. The functional layer is transferred to the transferred material by heating and press-bonding the functional layer to the transferred material, and then the release sheet is peeled off from the functional layer. Thus, the release sheet of the present invention can be used in what is also called stamping foil. Examples of the functional layer include metallic foil, pigment foil, multicolor printing foil, hologram foil, static electricity destruction foil, half-mirror metallic foil, and the like.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these.

(1) Unsaturated carboxylic acid component content in the polymer Infrared absorption spectrum analysis (Perkin Elmer Fourier transform infrared spectrophotometer System-2000, resolution 4 cm ^-1 ) was performed, and the unsaturated carboxylic acid in the polymer Contents of the components were obtained.

(2) Structure of polymer other than unsaturated carboxylic acid component ¹ H-NMR and ¹³ C-NMR analyzes (manufactured by JEOL Ltd., 500 MHz) were performed at 120°C in ortho-dichlorobenzene (d ₄ ) to obtain rice field. In the ¹³ C-NMR analysis, a gated decoupling method was used in consideration of quantification.

(3) Number average molecular weight Using GPC analysis (manufactured by Tosoh Corporation, HLC-8020, column TSK-GEL), the sample was dissolved in tetrahydrofuran and measured at 40 ° C., and the number from the calibration curve created with a polystyrene standard sample. An average molecular weight was determined. Ortho-dichlorobenzene was used when it was difficult to dissolve in tetrahydrofuran.

(4) Melt flow rate Measured at 190°C under a load of 2160g according to the method described in JIS K7210:1999.

(5) Solid Content Concentration of Aqueous Dispersion An appropriate amount of the polymer aqueous dispersion was weighed and heated at 150° C. until the mass of the residue (solid content) reached a constant weight to determine the solid content concentration.

(6) Contents of Olefin Component, Unsaturated Carboxylic Acid Component, and (Meth)Acrylic Acid Ester Component in Resin Layer The polyethylene terephthalate resin constituting the base material of the obtained release sheet was treated with hexafluoroisopropanol (HFIP). It was dissolved and only the resin layer was collected. The separated resin layer was subjected to solid-state ¹³ C-NMR analysis (manufactured by JEOL Ltd., 500 MHz) and determined. In the solid-state ¹³ C-NMR analysis, the DD/MAS method was used in consideration of quantitative properties.

(7) Peel strength (25°C)
An acrylic adhesive tape (manufactured by Nitto Denko, No. 31B/acrylic adhesive) having a width of 50 mm and a length of 150 mm was pressed on the resin layer side of the obtained release sheet with a rubber roll to obtain a sample for peel strength measurement. and The peel strength between the adhesive tape and the release sheet of this peel strength measurement sample was measured in a constant temperature room at 25° C. with a tensile tester (Intesco, precision universal material testing machine, 2020 type). The peeling angle was 180 degrees and the peeling speed was 300 mm/min.

(8) Peel strength (25°C - after 24 hours)
An acrylic pressure-sensitive adhesive tape (No. 31B/acrylic pressure-sensitive adhesive manufactured by Nitto Denko Co., Ltd.) having a width of 50 mm and a length of 150 mm was press-bonded to the resin layer side of the obtained release sheet with a rubber roll to obtain a sample. The sample was sandwiched in the form of metal plate/rubber plate/sample/rubber plate/metal plate, and left in an atmosphere of 25° C. under a load of 2 kPa for 24 hours to obtain a sample for peel strength measurement. The peel strength between the adhesive tape and the release sheet of this peel strength measurement sample was measured in a constant temperature room at 25° C. with a tensile tester (Intesco, precision universal material testing machine, 2020 type). The peeling angle was 180 degrees and the peeling speed was 300 mm/min.

(9) Peel strength (70°C - after 24 hours)
An acrylic pressure-sensitive adhesive tape (No. 31B/acrylic pressure-sensitive adhesive manufactured by Nitto Denko Co., Ltd.) having a width of 50 mm and a length of 150 mm was press-bonded to the resin layer side of the obtained release sheet with a rubber roll to obtain a sample. The sample was sandwiched in the form of metal plate/rubber plate/sample/rubber plate/metal plate and left in an atmosphere of 2 kPa load and 70° C. for 24 hours to obtain a sample for peel strength measurement. The peel strength between the adhesive tape and the release sheet of this peel strength measurement sample was measured in a constant temperature room at 25° C. with a tensile tester (Intesco, precision universal material testing machine, 2020 type). The peeling angle was 180 degrees and the peeling speed was 300 mm/min.

(10) Residual adhesion rate (7) Peel strength test (25 ° C.), (8) Peel strength test (25 ° C.-after 24 hours) and (9) Peel strength test (70 ° C.-24 hours) After), an acrylic adhesive tape with a width of 50 mm and a length of 150 mm (manufactured by Nitto Denko, No. 31B / acrylic adhesive) peeled off from the surface of the release sheet is attached to a stainless steel plate (SUS304, thickness 1 mm). , under a load of 2 kPa, and left at room temperature for 20 hours. After that, the peel strength between the acrylic pressure-sensitive adhesive tape and the stainless steel plate was measured in a constant temperature room at 25° C. with a tensile tester (manufactured by Intesco, precision universal material testing machine, model 2020). The peeling angle was 180 degrees and the peeling speed was 300 mm/min. The peel strengths obtained by this measurement were defined as F1 ₍₇₎ , F1 _{(8), and} F1 ₍₉₎ , respectively.
A 50 mm wide, 150 mm long acrylic adhesive tape (Nitto Denko No. 31B/acrylic adhesive) was attached to a stainless steel plate (SUS304, thickness 1 mm), and left at room temperature under a load of 2 kPa for 20 hours. After that, the peel strength of the acrylic adhesive tape and the stainless steel plate was measured in a constant temperature room at 25 ° C with a tensile tester (manufactured by Intesco, precision universal material testing machine, 2020 type) (peeling angle was 180 degrees, peeling speed was 300 mm/min), and the obtained peel strength was taken as F2.
Using the following formula, the residual adhesion rate of each adhesive tape was obtained.
Residual adhesion rate after leaving at 25°C (%) = (F1 ₍₇₎ / F2) x 100
25 ° C., residual adhesion rate after 24 hours (%) = (F1 ₍₈₎ / F2) × 100
70 ° C., residual adhesion rate after 24 hours (%) = (F1 ₍₉₎ / F2) × 100
If the surface of the adhesive layer of the adhesive tape is contaminated with a release sheet, or if the surface of the adhesive tape is significantly roughened during peeling, the re-adhesiveness of the adhesive tape is reduced and the performance as an adhesive tape is impaired. Therefore, the higher the residual adhesion rate, the better.

(11) Blocking resistance Two pieces of the obtained release sheet were cut into a size of 50 mm × 50 mm, overlapped so that the resin layer surface and the base material surface were in contact, and a load of 10 kPa was applied at 60 ° C. After leaving it for 24 hours, removing the load and cooling to room temperature, the blocking resistance was evaluated by examining the adhesion state between the resin layer surface and the base material surface.
◯: The two sheets are not adhered to each other, or the two sheets are easily peeled off, and no change such as whitening is observed in the resin layer.
Δ: Adhesion is observed between the two sheets, but no change such as whitening is observed in the resin layer.
x: The resin layer caused cohesive failure, or the resin layer was entirely white after the two sheets were peeled off.

(12) Coefficient of dynamic friction From the obtained release sheet, release sheet 1 and release sheet 2 are cut out, and the resin layer surface of release sheet 1 and release sheet ² are separated so that the contact area is 40 cm The surface of the substrate was superimposed, and the coefficient of dynamic friction was measured according to JIS K7125.

(13) Haze (Hz)
The haze of the obtained release sheet was measured according to JIS K7136 using a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.).

(14) Continuous Runability In Examples 2, 5 to 6, 14, 16 to 19, 21 to 28, and Comparative Example 5, the runnability was evaluated when releasing sheets were produced continuously for 24 hours. That is, a circulation system consisting of a liquid transfer pump and a cartridge filter (Advantech Toyo Co., Ltd. TCW-10N-PPS (nominal pore diameter 10 μm)) is connected to a liquid receiving pan containing a water-based coating agent, and the liquid is sent at a pressure of 0.2 MPa. Continuous operability was evaluated based on the number of times the filter was replaced when clogging occurred during gravure coating.
○: Filter replacement 0 times △: Filter replacement 1 time ×: Filter replacement 2 times or more

The following polymers were synthesized as polymers constituting the resin layer, and then aqueous dispersions were produced for each including commercially available polymers.
Synthesis Example 1: Polymer P-1
280 g of a propylene/ethylene copolymer (mass ratio: propylene/ethylene = 62.3/37.7, number average molecular weight = 3,500) was heated and dissolved in 470 g of xylene in a four-necked flask under a nitrogen atmosphere. After that, 60 g of maleic anhydride as an unsaturated carboxylic acid and 30 g of dicumyl peroxide as a radical generator were each added over 2 hours while stirring while maintaining the system temperature at 140° C., followed by reacting for 6 hours. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-1 comprising an acid-modified α-olefin/ethylene copolymer.

Synthesis Example 2: Polymer P-2
In Synthesis Example 1, a propylene/ethylene copolymer (number average molecular weight = 8,100) having a mass ratio (propylene/ethylene) of 56.9/43.1 was used, maleic anhydride was added in an amount of 30 g, dicumyl A polymer P-2 composed of an acid-modified α-olefin/ethylene copolymer was synthesized by performing the same procedure, except that the amount of peroxide was changed to 25 g.

Synthesis Example 3: Polymer P-3
In Synthesis Example 1, a propylene/ethylene copolymer (number average molecular weight = 5,200) having a mass ratio (propylene/ethylene) of 57.3/42.7 was used, and the amount of maleic anhydride was changed to 20 g. A polymer P-3 composed of an acid-modified α-olefin/ethylene copolymer was synthesized by performing the same operations except for the above.

Synthesis Example 4: Polymer P-4
After 280 g of a propylene/ethylene copolymer (mass ratio: propylene/ethylene = 64.8/35.2) was heated and dissolved in 470 g of xylene in a four-necked flask under a nitrogen atmosphere, the temperature in the system was brought to 140°C. 30 g of maleic anhydride and 25 g of dicumyl peroxide were added over 2 hours while stirring, and the mixture was allowed to react for 6 hours. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride and then dried under reduced pressure to synthesize a polymer P-4 consisting of an acid-modified α-olefin/ethylene copolymer.

Synthesis Example 5: Polymer P-5
280 g of a propylene/butene/ethylene terpolymer (mass ratio: propylene/1-butene/ethylene = 64.8/23.9/11.3) was heated and melted in a four-necked flask under a nitrogen atmosphere. let me After that, while maintaining the system temperature at 170° C., 32 g of maleic anhydride and 6 g of dicumyl peroxide were each added over 1 hour while stirring, and then reacted for 1 hour. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-5 consisting of an acid-modified α-olefin/ethylene copolymer.

Synthesis Example 6: Polymer P-6
100 g of a propylene/ethylene copolymer (mass ratio: propylene/ethylene=25/75) was dissolved in 400 g of xylene heated to 130° C. in a four-necked flask under a nitrogen atmosphere. Next, 10 g of a toluene solution of maleic anhydride (5% by mass) and 5 g of a toluene solution of dicumyl peroxide (10% by mass) were each added to this solution over 30 minutes, and then the system was kept at 130°C. , reacted for 4 hours. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride and then dried under reduced pressure to synthesize a polymer P-6 consisting of an acid-modified α-olefin/ethylene copolymer.

Synthesis Example 7: Polymer P-7
280 g of a propylene-ethylene copolymer (mass ratio: propylene/ethylene=97.9/2.1) was heated and melted in a four-necked flask under a nitrogen atmosphere. After that, while maintaining the temperature in the system at 170° C., 10 g of maleic anhydride and 6 g of dicumyl peroxide were each added over 1 hour while stirring, and then reacted for 1 hour. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride and then dried under reduced pressure to synthesize a polymer P-7 consisting of an acid-modified α-olefin/ethylene copolymer.

Production Example 1: Aqueous Dispersion E-1 of Polymer P-1
Using a stirrer equipped with a sealed, pressure-resistant 1 L glass vessel equipped with a heater, 45.0 g of polymer P-1, 93.0 g of tetrahydrofuran, 2.0 g of cyclohexane, 30.6 g of triethylamine and 129.4 g of of distilled water was introduced into a glass container and stirred at a rotational speed of a stirring blade of 300 rpm. While maintaining this state, the heater was turned on to heat, and the temperature in the system was kept at 110° C. and stirred for 60 minutes. After that, the mixture was cooled to room temperature (about 25° C.) while being placed in a water bath and stirred, and 165.0 g of distilled water and 3.2 g of N,N-dimethylethanolamine (hereinafter referred to as DMEA) were added. The resulting aqueous dispersion was placed in a 1 L eggplant flask, and the pressure was reduced using an evaporator while being placed in a hot water bath heated to 60° C. to distill off 243.2 g of the aqueous medium. After cooling, the liquid component in the flask is pressure-filtered (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky-white uniform aqueous dispersion E of polymer P-1. -1 was obtained.

Production Example 2: Aqueous Dispersion E-2 of Polymer P-2
54.0 g of polymer P-2, 57.6 g of isopropanol, 33.9 g of triethylamine and 154.5 g of distilled water were mixed in a glass vessel using a stirrer equipped with a heater and a sealable pressure-resistant 1 L glass vessel. The mixture was charged into the inside and stirred at a rotational speed of the stirring blade of 300 rpm. While maintaining this state, the heater was turned on to heat, and the temperature in the system was kept at 120° C. and stirred for 60 minutes. After that, the mixture was cooled to room temperature (about 25° C.) while stirring in a water bath, and 176.7 g of distilled water was added. The resulting aqueous dispersion was placed in a 1 L eggplant flask, and the pressure was reduced using an evaporator while being placed in a hot water bath heated to 60° C. to distill off 206.7 g of the aqueous medium. After cooling, the liquid component in the flask was filtered under pressure (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform aqueous dispersion E of polymer P-2. -2 was obtained.

Production Example 3: Aqueous Dispersion E-3 of Polymer P-3
Using a stirrer equipped with a sealed, pressure-resistant 1 L glass vessel equipped with a heater, 45.0 g of polymer P-3, 90.9 g of tetrahydrofuran, 2.1 g of cyclohexane, 9.0 g of triethylamine and 153.0 g of triethylamine were added. of distilled water was introduced into a glass container and stirred at a rotational speed of a stirring blade of 300 rpm. While maintaining this state, the heater was turned on to heat, and the temperature in the system was kept at 110° C. and stirred for 60 minutes. After that, the mixture was cooled to room temperature (about 25° C.) while stirring in a water bath, and 55.2 g of distilled water and 7.9 g of DMEA were added. The resulting aqueous dispersion was placed in a 1-L eggplant flask, and the pressure was reduced using an evaporator while being placed in a hot water bath heated to 60° C. to distill off 138.1 g of the aqueous medium. After cooling, the liquid component in the flask is filtered under pressure (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform aqueous dispersion E of polymer P-3. -3 was obtained.

Production Example 4: Aqueous Dispersion E-4 of Polymer P-4
A milky-white uniform aqueous dispersion E-4 of the polymer P-4 was obtained in the same manner as in Production Example 2, except that the polymer P-4 was used.

Production Example 5: Aqueous Dispersion E-5 of Polymer P-5
Using a stirrer equipped with a sealed, pressure-resistant 1 L glass vessel equipped with a heater, 45.0 g of polymer P-5, 105.0 g of tetrahydrofuran, 3.0 g of cyclohexane, 9.0 g of DMEA and 138.0 g of DMEA were mixed. of distilled water was introduced into a glass container and stirred at a rotational speed of a stirring blade of 300 rpm. While maintaining this state, the heater was turned on to heat, and the temperature in the system was kept at 125° C. and stirred for 60 minutes. After that, the mixture was cooled to room temperature (about 25° C.) while stirring in a water bath, and 80.0 g of distilled water was added. The resulting aqueous dispersion was placed in a 1 L eggplant flask, and the pressure was reduced using an evaporator while being placed in a hot water bath heated to 60° C. to distill off 155.0 g of the aqueous medium. After cooling, the liquid component in the flask is filtered under pressure (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform aqueous dispersion E of polymer P-5. -5 was obtained.

Production Example 6: Aqueous Dispersion E-6 of Polymer P-6
25.0 g of polymer P-6 and 4,975 g of tetrahydrofuran were mixed, heated, and stirred to prepare a P-6 solution having a P-6 content of 0.5% by mass.
Next, 10,000 g of distilled water is charged into a container equipped with a stirrer and a heater, and while stirring with a stirrer, 5,000 g of the P-6 solution is gradually added over 5 minutes, and distilled water and An aqueous dispersion was made consisting of the P-6 solution. At this time, the polyolefin resin was uniformly dispersed in the aqueous dispersion (uniformly cloudy).
The resulting aqueous dispersion was heated to 60° C. with a heater, and the pressure inside the container was gradually reduced while stirring. The vapor of tetrahydrofuran and water generated by heating and pressure reduction was condensed outside the vessel and distilled out of the vessel. When the mass of the aqueous dispersion in the container became 200 g or less, the aqueous dispersion was pressure-filtered through a 300-mesh stainless steel filter (wire diameter: 0.035 mm, plain weave). At this time, there was no undispersed matter on the filter after filtration. Distilled water was added to the filtered aqueous dispersion to adjust the solid content concentration to 10% by mass. Thus, a milky white uniform aqueous dispersion E-6 of the polymer P-6 was obtained.

Production Example 7: Aqueous Dispersion E-7 of Polymer P-7
A milky-white uniform aqueous dispersion E-7 of the polymer P-7 was obtained in the same manner as in Production Example 5, except that the polymer P-7 was used.

Production Example 8: Aqueous Dispersion E-8 of Polymer P-8
Using a stirrer equipped with a pressure-resistant 1-liter glass container that can be sealed with a heater, 60.0 g of acid-modified polyethylene resin polymer P-8 (manufactured by Arkema, Bondine LX-4110, mass ratio: ethylene / Acrylic acid ester/maleic anhydride = 91/7/2), 75.0 g of n-propanol, 2.5 g of triethylamine and 162.5 g of distilled water were charged in a glass container, and the rotation speed of the stirring blade was set at 300 rpm. As a result of stirring, no sedimentation of the resin particles was observed at the bottom of the container, confirming that they were in a floating state. Therefore, while maintaining this state, after 10 minutes, the power of the heater was turned on to heat. Then, the temperature in the system was kept at 120° C. and the mixture was further stirred for 30 minutes. After that, the mixture was cooled to room temperature (about 25° C.) while stirring in a water bath, and 147.8 g of distilled water and 2.2 g of DMEA were added. added. The resulting aqueous dispersion was placed in a 1-L eggplant flask, and the pressure was reduced using an evaporator while being placed in a hot water bath heated to 60° C. to distill off 150.0 g of the aqueous medium. After cooling, the liquid component in the flask is pressure-filtered (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform aqueous dispersion E of polymer P-8. -8 was obtained.

Production Example 9: Aqueous Dispersion E-9 of Polymer P-9
Using a stirrer equipped with a pressure-resistant 1-liter glass container that can be sealed with a heater, 60.0 g of acid-modified polyethylene resin polymer P-9 (manufactured by Dow Chemical Company, Primacol 5980I, mass ratio: ethylene/ acrylic acid = 80/20), 16.8 g of triethylamine, and 223.2 g of distilled water were placed in a glass container and stirred with a stirring blade at a rotational speed of 300 rpm. It was confirmed that it was in a floating state. Therefore, while maintaining this state, after 10 minutes, the power of the heater was turned on to heat. Then, the temperature in the system was kept at 120° C. and the mixture was further stirred for 40 minutes. Then, after cooling to room temperature (approximately 25° C.) with air cooling while stirring at a rotation speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave). to obtain an aqueous dispersion E-9 of slightly cloudy polymer P-9.

The polymer composition, properties, and solids concentration of the aqueous dispersion are shown in Table 1.

As the cross-linking agent and polyvinyl alcohol constituting the resin layer, the following were used.
WS700: Oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., Epocross WS-700)
WS500: Oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., Epocross WS-500)
E-02: Carbodiimide compound (manufactured by Nisshinbo, Carbodilite E-02)
EM-051R: Epoxy compound (Adeka resin EM-051R manufactured by Adeka)
HW-100: isocyanate compound (manufactured by BASF, Vasonato HW-100)
VC-10: Polyvinyl alcohol (VC-10 manufactured by Japan Vinyl Acetate & Poval Co., Ltd., degree of saponification 99.3 mol% or more, average degree of polymerization 1,000)
JT-05: Polyvinyl alcohol (manufactured by Japan Vinyl Acetate and Poval, JT-05, degree of saponification 93.5 to 94.5 mol%, average degree of polymerization 500)
JF-05: Polyvinyl alcohol (manufactured by Japan Vinyl Acetate & Poval Co., Ltd., JF-05, degree of saponification 98.0 to 99.0 mol%, average degree of polymerization 500)

Example 1
50 parts by mass of P-1 as a polymer (A) composed of an acid-modified α-olefin/ethylene copolymer, 50 parts by mass of P-8 as a polymer (B) composed of an acid-modified polyethylene resin, and 10 parts of a cross-linking agent. An aqueous coating agent prepared by mixing each aqueous dispersion so that parts by mass and polyvinyl alcohol is 10 parts by mass is applied to a biaxially stretched polyester resin film (Emblet PET-38 manufactured by Unitika Ltd., thickness 38 μm, one side After applying it to the corona-treated surface of the corona-treated) using a Meyer bar, it was dried at 140 ° C. for 15 seconds to form a resin layer with a thickness of 0.2 μm on the film, and then aged at 50 ° C. for 2 days. A release sheet was obtained by performing.

Examples 3-4, 7-13, 15, 20, 29-30, Comparative Examples 1-4, 6
Separated in the same manner as in Example 1, except that the types and parts by mass of the polymers (A), (B), cross-linking agent, and polyvinyl alcohol were changed to those shown in Tables 2 and 4 to prepare a water-based coating agent. Got a template sheet.

Example 2
Polyethylene terephthalate resin (manufactured by Nippon Ester Co., Ltd., intrinsic viscosity 0.6) was extruded using an extruder equipped with a T die (75 mm diameter, slow compression type single screw with L / D of 45), cylinder temperature 260 ° C., T die It was extruded into a sheet at a temperature of 280° C., and was quenched by closely contacting it on a cooling roll whose surface temperature was adjusted to 25° C. to obtain an unstretched film having a thickness of 500 μm. Subsequently, after stretching 3.4 times in the longitudinal direction at 90° C., the water-based coating agent prepared in Example 1 was dried using a gravure coater, and the coating amount after stretching was 0.2 g/m ² . Next, after preheating at a temperature of 90° C. for 2 seconds, it was stretched in the transverse direction at a magnification of 3.0 times at 240° C. to obtain a release sheet. The total thickness of the obtained polyester film and resin layer was 50 μm.

Examples 5-6, 14, 16-19, 21-28, Comparative Example 5
Polymers (A), (B), cross-linking agent, polyvinyl alcohol in the same manner as in Example 2 except that a water-based coating agent prepared by changing the types and parts by weight shown in Tables 2 and 4 was applied. , to obtain a release sheet.

Tables 3 and 5 show the evaluation results of the release sheets obtained in Examples and Comparative Examples.

In the release sheets obtained in Examples 1 to 30, the dynamic friction coefficient of the resin layer is 0.50 or less, the dynamic friction coefficient is low, and the peel strength at 25 ° C. with the acrylic adhesive is 0.5 N / cm or less, the releasability was excellent, and the releasability after being heated was also excellent. Moreover, the peeled adhesive material maintained a high residual adhesion rate.
In the resin layer, the content of the (meth)acrylic acid ester component was in a particularly preferable range, and the release sheet of Example containing two kinds of polymers had a small dynamic friction coefficient. Moreover, in the resin layer, the release sheet containing polyvinyl alcohol having a saponification degree in a more preferable range was excellent in continuous workability.
On the other hand, the release sheets of Comparative Examples 1 and 6 had high coefficients of dynamic friction and poor productivity.
The release sheets of Comparative Examples 2 to 5 were inferior in releasability because the mass ratio of the α-olefin component/ethylene component in the resin layer was out of the range specified in the present invention.

Claims (7)

A release sheet obtained by providing a resin layer on a base material,
one or more polymers constituting the resin layer contain, as copolymer components, an olefin component, an unsaturated carboxylic acid component and a (meth)acrylic acid ester component ,
the olefin component contains an α-olefin component and an ethylene component,
The mass ratio of the α-olefin component and the ethylene component (α-olefin component/ethylene component) is 10/90 to 60/40 in the resin layer,
The content of the (meth)acrylic acid ester component in the resin layer is 0.1 to 15% by mass,
The dynamic friction coefficient when the resin layer surface and the base material surface are superimposed is 0.45 or less,
A sample obtained by attaching the adhesive layer of a resin tape having an acrylic adhesive layer to the resin layer surface of a release sheet was subjected to a peeling angle of 180 degrees and a peeling speed of 300 mm / min at 25 ° C. A release sheet, wherein the peel strength between the pressure-sensitive adhesive layer and the resin layer is 0.5 N/cm or less when measured at . 2. The release sheet according to claim 1, wherein the content of the unsaturated carboxylic acid component in the resin layer is 0.1 to 15 mass %. The resin layer contains a cross-linking agent comprising an oxazoline compound and/or a carbodiimide compound, and the content of the cross-linking agent in the resin layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the polymer. The release sheet according to claim 1 or 2 . Any one of claims 1 to 3 , wherein the resin layer contains polyvinyl alcohol, and the content of polyvinyl alcohol in the resin layer is 0.1 to 1000 parts by mass with respect to 100 parts by mass of the polymer. The release sheet described in kani. 5. The release sheet according to claim 4 , wherein the degree of saponification of polyvinyl alcohol is 99 mol % or less. A method for manufacturing the release sheet according to claim 1,
A polymer (A) comprising an acid-modified α-olefin/ethylene copolymer, a polymer (B) comprising an acid-modified polyethylene resin containing a (meth)acrylic acid ester component as a copolymer component, and an aqueous medium. A method for producing a release sheet, which comprises coating a base material with a coalesced liquid material to form a resin layer. The mass ratio of the α-olefin component to the ethylene component (α-olefin component/ethylene component) in the polymer (A) composed of an acid-modified α-olefin/ethylene copolymer is 40/60 to 80/20 (however, 40 / 60 ).