TW201920560A - Release sheet - Google Patents

Abstract

A release sheet of this invention has a resin layer provided on a substrate, wherein the resin layer contains one or more polymers containing an olefin component and an unsaturated carboxylic acid component as copolymerization components, the olefin component contains an [alpha]-olefin component and an ethylene component, the mass ratio of the[alpha]-olefin component and the ethylene component ([alpha]-olefin component/ethylene component) is from 10/90 to 60/40 in the resin layer, the dynamic friction coefficient is 0.50 or less in the case that the resin layer surface and the base material surface are overlapped, and the peeling strength between a pressure-sensitive adhesive layer and the resin layer is 0.5 N/cm or less when a sample obtained by attaching the pressure-sensitive adhesive layer of a resin tape having an acrylic pressure-sensitive adhesive layer to the surface of the resin layer of the release sheet is used to measure the peeling strength at 25 DEG C with a peeling angle of 180 DEG and a peeling rate of 300 mm / min.

Description

Release film

The present invention relates to a release sheet.

The release sheet is used to protect the surface of an adhesive layer of an adhesive sheet used in various applications including manufacturing steps of electronic components such as semiconductor devices and precision equipment, and is bonded to the adhesive layer of the adhesive sheet.

In order to facilitate peeling from the adhesive sheet, a release agent-containing resin layer is provided on the surface of the substrate constituting the release sheet. The most commonly used release agent for release tablets is a silicone release agent. However, when a polysiloxane-based release agent is used, a low-molecular-weight polysiloxane compound contained in the polysiloxane-based release agent may migrate to the surface of the adhesive layer of the adhesive sheet and remain. It is pointed out that the polysiloxane remaining on the surface of the adhesive layer of the adhesive sheet will not only cause a decrease in the adhesive force of the adhesive, but also be slowly gasified. For example, the adhesive sheet may be accumulated on the surface of the used electronic component. Adversely affect its performance.

As for a non-silicone-based release agent for a release sheet, Patent Document 1 has proposed the use of a polypropylene-based acid-modified polyolefin, and Patent Document 2 has proposed the use of a polyethylene-based acid-modified polyolefin. In Patent Documents 3 and 4, the use of an acid-modified α-olefin / ethylene copolymer has been proposed.

The release sheets of Patent Documents 1 and 2 show good release properties for adhesive sheets. However, these release sheets have low heat resistance, so when they are stored at a high temperature in a state where they are bonded to the adhesive sheet, they may adhere firmly to the adhesive sheet, which may reduce the operability, and sometimes the release agent components may migrate. To the adhesive sheet, the adhesiveness of the peeled adhesive sheet is reduced. In particular, in the case of drying after being coated with an adhesive, or during the transfer of an adhesive sheet, if it is subjected to heat, the release property of the release sheet is liable to change, which is a poor operation.

The release sheets of Patent Documents 3 and 4 and the adhesive sheet are excellent in release properties and are also excellent in heat resistance, and can solve the problems in the release sheets of Patent Documents 1 and 2. However, the release sheet of Patent Document 3 is essentially a coating layer coated with an organic solvent solution to form a release layer, and there is still a problem with the working environment during production. In addition, the dynamic friction coefficient of the resin layer of the release sheet of Patent Documents 3 and 4 is large. In a continuous manufacturing step from roll to roll, a roll-shaped resin is produced by winding it around a core. When a laminated body is formed, wrinkles, bends, unevenness, and the like may be generated on the release sheet. As a result, the yield of the release sheet is reduced, resulting in a reduction in economic efficiency. Therefore, it is desired to have a release sheet which is not only excellent in release properties but also can reduce the coefficient of dynamic friction.

[Prior technical literature] [Patent Literature]

[Patent Document 1] International Publication No. 2014/109341

[Patent Document 2] International Publication No. 2014/109340

[Patent Document 3] International Publication No. 2015/064599

[Patent Document 4] Japanese Patent Laid-Open No. 2016-203570

In view of these problems, the subject of the present invention is to provide a resin layer provided with a resin layer having excellent release properties with adhesive materials, excellent heat resistance, and low coefficient of dynamic friction, and also suitable for continuous production from roll to roll. And a method for forming a resin layer using an aqueous coating solution.

In order to solve the above-mentioned problems, the present inventors have conducted careful research and found that by forming a resin layer having a specific composition on a substrate, the above-mentioned problems can be solved, and the present invention is finally achieved.

That is, the gist of the present invention is as follows.

(1) A release sheet obtained by providing a resin layer on a base material. The resin layer contains one or more polymers containing an olefin component and an unsaturated carboxylic acid component as a copolymerization component, and the olefin component contains α- The mass ratio of olefin component and ethylene component, α-olefin component and ethylene component (α-olefin component / ethylene component) in the resin layer is 10/90 to 60/40, which causes dynamic friction when the resin layer and the substrate surface are superimposed. When the coefficient is 0.50 or less, the sample obtained by bonding the aforementioned adhesive layer of a resin tape having an acrylic adhesive layer to the surface of the resin layer of a release sheet at 25 ° C at a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The peel strength of the adhesive layer and the resin layer at the time of measurement was 0.5 N / cm or less.

(2) The release sheet according to (1), wherein the polymer contains a (meth) acrylate component as a copolymerization component.

(3) The release sheet according to the item (2), wherein the content of the (meth) acrylate component in the resin layer is 0.1 to 15% by mass.

(4) The release sheet according to any one of (1) to (3), wherein the content of the unsaturated carboxylic acid component in the resin layer is 0.1 to 15% by mass.

(5) The release sheet according to any one of (1) to (4), wherein the resin layer contains The content of the crosslinking agent in the resin layer is 0.1 to 50 parts by mass based on 100 parts by mass of the polymer of the crosslinking agent composed of the oxazoline compound and / or the carbodiimide compound.

(6) The release sheet according to any one of (1) to (5), wherein the resin layer contains polyvinyl alcohol, and the content of the polyvinyl alcohol in the resin layer is 100 parts by mass based on the polymer. It is 0.1 to 1,000 parts by mass.

(7) The release sheet according to item (6), wherein the degree of saponification of polyvinyl alcohol is 99 mol% or less.

(8) A method for producing a release sheet, which is used to produce the release sheet described in item 1 of the scope of patent application, the production method is to apply a liquid material containing a polymer to a substrate to form a resin layer, The polymer-containing liquid includes a polymer (A) composed of an acid-modified α-olefin / ethylene copolymer, a polymer (B) composed of an acid-modified polyethylene resin, and an aqueous medium.

(9) The method for producing a release sheet according to item (8), wherein the mass of the α-olefin component and the ethylene component in the polymer (A) composed of an acid-modified α-olefin / ethylene copolymer The ratio (α-olefin component / ethylene component) is 40/60 to 80/20, excluding 40/60.

By using the release sheet of the present invention, the surface of the adhesive layer of the adhesive material can be protected. Since the release sheet of the present invention is excellent in heat resistance, it is excellent in release property after heat treatment after being attached to the adhesive material or the like. In addition, even when the release sheet of the present invention is stored at a high temperature after being adhered to the adhesive material, the resin layer component is not easy to migrate toward the adhesive material, and the peeled adhesive material can maintain a high residual adhesion rate. Furthermore, the dynamic friction coefficient of the resin layer of the release sheet of the present invention is small, and when a roll-shaped laminated body is produced by being wound around the core, it is difficult for the release sheet to generate wrinkles, bends, unevenness, etc., and it can be improved. Yield of release film.

The release sheet of the present invention can be manufactured by solving the problem of the working environment due to the use of an organic solvent by forming a resin layer having a release property on a substrate using an aqueous coating agent.

Hereinafter, the present invention will be described in detail.

The release sheet of the present invention is composed of a substrate and a resin layer provided thereon. The resin layer contains one or more polymers, and the polymer contains an olefin component and an unsaturated carboxylic acid component as a copolymerization component.

<Polymer>

In the present invention, the olefin component constituting the polymer must contain an α-olefin component and an ethylene component.

Examples of the α-olefin component 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 more preferable, and propylene is more preferable from the viewpoint of economy or availability. These α-olefin components may contain two or more kinds 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, preferably 15/85 to 50/50, and 20/80 to 40/60 is better.

If the mass ratio of the α-olefin component to the ethylene component in the resin layer is within the aforementioned range, the release sheet will have excellent release properties and excellent heat resistance. If the mass ratio of the α-olefin component to the ethylene content is outside the aforementioned range, not only the release property of the release sheet may decrease, but also the heat resistance tends to deteriorate. After being attached to the release sheet and maintained at a high temperature, The residual adhesion rate of the adhesive material system will be reduced.

In the present invention, the polymer must contain an unsaturated carboxylic acid component as a copolymerization component.

Examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like. There are also half esters of unsaturated dicarboxylic acids. , Hemiamine and so on. Among them, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable in order to disperse the polymer stably in the aqueous dispersion of the polymer described later, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferred. . These unsaturated carboxylic acid components may contain two or more kinds in the polymer. The unsaturated carboxylic acid component is not limited as long as it can be copolymerized in a polymer, and examples thereof include arbitrary 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, even more preferably 0.8 to 10% by mass, and even more preferably 1.5 to 7% by mass. When the content of the unsaturated carboxylic acid component is less than 0.5% by mass, the reaction with the crosslinking agent may be insufficient, and the heat resistance of the resin layer may be deteriorated. On the other hand, when it exceeds 20% by mass, the obtained release sheet tends to have reduced pressure-resistant adhesiveness, or the release property tends to decrease.

The content of the unsaturated carboxylic acid component in the cross-linking agent described later or the resin layer containing polyvinyl alcohol and the like is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, and 1 to 7% by mass. Even more preferred is 1.5 to 5 mass%. When the content of the unsaturated carboxylic acid component is less than 0.1% by mass, the obtained resin layer tends to have poor adhesion to the substrate. When it exceeds 15% by mass, the obtained release sheet tends to have reduced pressure resistance and release property.

In the present invention, the polymer preferably contains a (meth) acrylate component as a copolymerization component.

The (meth) acrylic acid ester component may be, for example, an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms. Among them, (meth) acrylic acid and 1 to 20 carbon atoms are easy to obtain. Esters of alcohols are preferred. Specific examples of such a compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, ( Octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. These mixtures can be used. The "(meth) acrylic acid ..." means "acrylic acid ... or methacrylic acid ...".

The content of the (meth) acrylate component in the polymer is preferably from 0.5 to 30% by mass, more preferably from 1 to 20% by mass, even more preferably from 1.5 to 15% by mass, and from 2 to 10% by mass Especially good. When the content of the (meth) acrylic acid ester component exceeds 30% by mass, not only the release property of the obtained resin layer is reduced, but also the liquid stability of the polymer-containing liquid substance may be reduced.

The content of the (meth) acrylic acid ester component in a cross-linking agent or a resin layer containing polyvinyl alcohol and the like described below is preferably from 0.1 to 15% by mass, more preferably from 0.5 to 10% by mass, and from 1 to 7% by mass For even better, 1.5 to 5 mass% is particularly preferred. If the content of the (meth) acrylic acid ester component in the resin layer is outside the aforementioned preferred range, the dynamic friction coefficient tends to be large.

In the present invention, the resin layer is a polymer containing the copolymerization component described above, but it may contain a polymer other than the above.

When the resin layer contains two or more kinds of polymers, each polymer need not satisfy the above-mentioned mass ratio of the α-olefin component to the ethylene component, the content of the unsaturated carboxylic acid component, and the content of the (meth) acrylate component, As long as the polymer or the resin layer satisfies the mass ratio of the α-olefin component to the ethylene component, the content of the unsaturated carboxylic acid component, and the content of the (meth) acrylate component, the resin layer may also contain no Copolymer of polymers.

The type of the polymer is not limited, but a polyolefin resin is preferred from the viewpoints of ease of handling and stability. Specific examples of the polyolefin resin include, for example, low / medium / high-density polyethylene (branched or linear) ethylene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene-4 -Methyl-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl alcohol copolymer (including ethylene-acetic acid Vinyl resins such as vinyl ester copolymers), ethylene- (meth) acrylic copolymers; propylene homopolymers, propylene-ethylene copolymers, propylene-ethylene-1-butene copolymers, and other propylene resins; 1- 1-butene resins such as butene homopolymer, 1-butene-ethylene copolymer, 1-butene-propylene copolymer; noropenne ring-opening metathesis polymer or norbornene derivative-ethylene copolymer So-called cyclic polyolefin resins; ethylene-propylene-butene-maleic anhydride copolymer, ethylene- (meth) acrylate-maleic anhydride copolymer, ethylene- (meth) acrylic copolymer, ethylene-male Acid modified polyolefins such as maleic anhydride copolymer, propylene-maleic anhydride copolymer, ethylene-propylene-maleic anhydride copolymer, ethylene-butene-maleic anhydride copolymer, propylene-butene-maleic anhydride copolymer Resin, etc.

The polymerization method of the polyolefin resin is not limited, but specific examples thereof include a high-pressure method, a slurry method, a solution method, and a gas phase method. The polymerization catalyst is not particularly limited as Ziegler catalyst, metallocene catalyst, and the like.

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

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

<Polymer (A) composed of acid-modified α-olefin / ethylene copolymer>

A polymer (A) based on an acid-modified α-olefin / ethylene copolymer is an acid-modified α-olefin / ethylene copolymer, and the α-olefin / ethylene copolymer contains more than one type of α-olefin component and Ethylene composition.

Examples of the α-olefin 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 preferable from the viewpoint of economy or 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 preferably 40/60 to 80/20 (however, excluding 40/60 ). That is, relative to the total mass of the α-olefin and ethylene, the mass of the α-olefin is more than 40% by mass, preferably 80% by mass or less, more preferably 50% by mass, and 51% by mass or more. More preferably, it is more preferably 70% by mass or less, and 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) to the aforementioned range, a release sheet having a resin layer containing the polymer (A) is provided. This means that it is difficult to contaminate the surface of the adherend even if it is exposed for a long time at a high temperature in a state where the adherend is attached.

The α-olefin / ethylene copolymer constituting the polymer (A) preferably has a coefficient average molecular weight of 500 to 25,000, more preferably 700 to 20,000, and even more preferably 1,000 to 17,000. By modifying the α-olefin / ethylene copolymer acid having a number average molecular weight in the aforementioned range, the number average molecular weight of the polymer (A) can be adjusted to a range described later.

The α-olefin / ethylene copolymer constituting the polymer (A) is preferred It is manufactured using a metallocene catalyst. The α-olefin / ethylene copolymer system 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, even more preferably 0.5 to 10% by mass, and even more preferably 1 to 10% by mass. Particularly preferred is 1.5 to 10% by mass. When the content of the polymer (A) -based acid-modified component is less than 0.5% by mass, it may be difficult to disperse it in an aqueous medium by a method described later, and the obtained resin layer may not have good adhesion to the substrate. Sufficient, the reaction with the crosslinking agent is insufficient, and the heat resistance is deteriorated.

The acid modification of the α-olefin / ethylene copolymer can be performed, 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, and crotonic acid. In addition, there are half esters of unsaturated dicarboxylic acids, hemiamines, and the like. Among them, maleic anhydride, acrylic acid, and methacrylic acid are preferred from the viewpoint of ease of introduction of the α-olefin / ethylene copolymer, and maleic anhydride is more preferred. These unsaturated carboxylic acid components may contain two or more kinds in the polymer.

The unsaturated carboxylic acid component may be copolymerized in the α-olefin / ethylene copolymer, and its form is not limited, and examples thereof include arbitrary copolymerization, block copolymerization, and graft copolymerization.

The number average molecular weight of the polymer (A) is preferably 1,000 to 30,000, more preferably 1,200 to 25,000, and 1,500 to 20,000 is even better. The polymer (A) has a number-average molecular weight in the aforementioned range, and can produce a uniform aqueous dispersion having a good dispersion state.

As the α-olefin / ethylene copolymer for acid modification, a commercially available α-olefin / ethylene copolymer can be used. Commercially available α-olefin / ethylene copolymers include, for example, LX020, LX100, LX200, LX400, etc. of the LUCANT series manufactured by Mitsui Chemicals. The polymer (A) can be obtained by acid-modifying such a commercially available α-olefin / ethylene copolymer.

As the polymer (A), a commercially available one can be used. Commercially available polymers (A) include, for example, A-5515, A-5260, A-5320H, etc. of the LUCANT series manufactured by Mitsui Chemicals.

<Polymer (B) composed of acid-modified polyethylene resin>

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

The olefin component constituting the polymer (B) is ethylene. In addition to ethylene, it may contain propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 4-methyl-1-pentene and the like. Olefins of 6 to 6 or these mixtures, but the content of olefin components other than ethylene is preferably 20% by mass or less based on the total mass of the 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, even more preferably 0.5 to 15% by mass, and even more preferably 1 to 10% by mass. optimal. When the content of the polymer (B) -based acid modification component is less than 0.1% by mass, it may be difficult to use The method described later disperses in an aqueous medium, and the obtained resin layer may have poor adhesion to the substrate.

The acid modification of the polymer (B) can also be performed by introducing an unsaturated carboxylic acid or its anhydride into a 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, and crotonic acid. There are still half-esters of unsaturated dicarboxylic acids, hemiamines, and the like. Among them, maleic anhydride, acrylic acid, and methacrylic acid are preferred from the viewpoint of ease of introduction of polyethylene resin, and maleic anhydride is more preferred. These unsaturated carboxylic acid components may contain two or more kinds in the polymer.

The unsaturated carboxylic acid component is not limited as long as it can be copolymerized in a polyethylene resin, and examples thereof include arbitrary copolymerization, block copolymerization, and graft copolymerization.

In the present invention, the polymer (B) preferably contains a (meth) acrylate component as a copolymerization component.

The (meth) acrylic acid ester component may be, for example, an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms. Among them, (meth) acrylic acid is 1 to 20 carbon atoms in terms of ease of obtaining Esters of alcohols are preferred. Specific examples of such a compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, ( Octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. These mixtures can 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, even more preferably 1.5 to 20% by mass, and even more preferably 2 to 15% by mass is particularly good. When the content of the (meth) acrylic acid ester component is less than 0.5% by mass, when the resin layer containing the polymer (B) is left in a state in which an adhesive material is attached, the peeling strength tends to increase with time. On the other hand, when it exceeds 40% by mass, when the aqueous dispersion of the polymer (B) is produced by a method to be described later, the liquid stability of the dispersion may decrease.

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

The polymer (B) can use a melt flow rate of 190 ° C and a load of 2160 g, which is a molecular weight standard, of 0.01 to 500 g / 10 minutes, preferably 0.1 to 300 g / 10 minutes, and more preferably 0.1 to 250 g / 10 minutes. More preferably, it is 0.5 to 200 g / 10 minutes, and most preferably, it is 1 to 100 g / 10 minutes. When the melt flow rate of the polymer (B) is less than 0.01 g / 10 minutes, it is difficult to disperse the polymer (B) in water by a method described later. On the other hand, when the melt flow rate of the polymer (B) exceeds 500 g / 10 minutes, a release sheet provided with a resin layer containing the polymer (B) is exposed at a high temperature for a long time in a state where the adherend is attached. When it is easy to contaminate the surface of the adherend.

The method for synthesizing the polymer (B) in the present invention is not particularly limited, and is, for example, obtained by subjecting the monomer constituting the polymer (B) to high-pressure radical copolymerization in the presence of a radical generator. Moreover, an unsaturated carboxylic acid may be graft-copolymerized.

<Crosslinking agent>

In the present invention, the resin layer of the release sheet preferably contains a crosslinking agent. By containing a cross-linking agent, the constituents of the resin layer are cross-linked, and various properties such as release properties, cohesiveness, 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 can react with the unsaturated carboxylic acid component constituting the polymer can be used. An oxazoline compound, a carbodiimide compound, an epoxy compound, an isocyanate compound, and the like. From the viewpoint of reactivity, it is preferably selected from A crosslinking agent for at least one of an oxazoline compound and a carbodiimide compound.

The oxazoline compound is only required to have two or more molecules in the molecule. An oxazoline group is sufficient, and it does not specifically limit. For example, 2,2'-double (2- Oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2- Oxazoline), 2,2'-p-phenylene-bis (2- Oxazoline), bis (2- Oxazolinyl cyclohexane) sulfide etc. have Oxazoline-based compounds, or An oxazoline-based polymer. One or more of these may be used. Among these, in terms of ease of handling, An oxazoline-based polymer is preferred.

contain An oxazoline-based polymer can be obtained by making 2-vinyl-2- Oxazoline, 2-vinyl-4-methyl-2- Oxazoline, 2-isopropenyl-2- Additive polymerizability such as oxazoline It is obtained by polymerization of oxazoline. Other monomers can be copolymerized as required. contain The polymerization method of the oxazoline-based polymer is not particularly limited, and various known polymerization methods can be adopted.

contain Commercially available products of oxazoline-based polymers include, for example, EPOCROS series made by Japan Catalyst Corporation. Specifically, for example, water-soluble types "WS-500", "WS-700", and solid-type "RPS" -1005 "and so on.

As for the carbodiimide compound, as long as it has The number of carbodiimide groups is at least two, and it is not particularly limited. Examples include p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (third butylcarbodiimide), cyclohexane-1,4 -A polycarbodiimide of a compound having a carbodiimide group such as bis (methylene-third butylcarbodiimide) or a polymer having a carbodiimide group. One or more of these may be used. Among these, polycarbodiimide is preferred in terms of ease of handling.

The production method of polycarbodiimide is not particularly limited. The polycarbodiimide system can be produced, for example, by a condensation reaction accompanied by decarbonation of an isocyanate compound. The isocyanate compound is not limited, and may be any of an aliphatic isocyanate, an alicyclic isocyanate, and an aromatic isocyanate. The isocyanate compound may be copolymerized with a polyfunctional liquid rubber, a polyalkylene glycol, or the like as necessary.

Commercially available products of polycarbodiimide include, for example, the Carbodilite series manufactured by Nisshinbo Corporation. Specifically, for example, water-soluble types such as "SV-02", "V-02", and "V-02-L2" , "V-04", emulsion type "E-02", "E-03A", "E-04", organic solution type "V-01", "V-03", "V-07", "V-09", solvent-free version "V-05", etc.

by The content of the resin layer of the crosslinking agent composed of the oxazoline compound and / or the carbodiimide compound is preferably 0.1 to 50 parts by mass, and 0.5 to 40 parts by mass relative to 100 parts by mass of the polymer. More preferably, 1 to 30 parts by mass is even more preferred, and 2 to 20 parts by mass is particularly preferred. The content of the cross-linking agent is less than 0.1 parts by mass relative to 100 parts by mass of the polymer, the addition effect is lacking, and the release property of the obtained resin layer may decrease with time, or sufficient heat resistance may not be obtained. 100 parts by mass. If the content exceeds 50 parts by mass, the softness of the resin layer may be impaired, and the peel strength may be increased. Moreover, a crosslinking agent can also be used simultaneously. When an oxazoline compound and a carbodiimide compound are used at the same time, the total amount of the crosslinking agent must satisfy the above-mentioned range of the content of the crosslinking agent.

The epoxy compound is not particularly limited, and examples thereof include bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerol polyglycidyl ether, and polyglycerol. Epoxy compounds such as polyglycidyl ether.

Commercial products of epoxy compounds include, for example, Dynacol series (EM-150, EM-101, etc.) manufactured by Nagase Chemtex, and Adeka series EM-0517, EM-0526, EM-11-50B, EM manufactured by Adeka Corporation. -051R, SR-GSG, SR-4GSL, etc. manufactured by Sakamoto Pharmaceutical Industry Co., Ltd.

The isocyanate compound is not particularly limited as long as it has at least two isocyanate groups in the molecule. Examples include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane 2,4'- or 4,4'-diisocyanate, polymethylene polyphenyl diisocyanate, and toluidine Diisocyanate, 1,4-diisocyanate butane, hexamethylene diisocyanate, 1,5-diisocyanate-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, xylene diisocyanate, 1,3-bis (Isocyanatomethyl) cyclohexane, tetramethylxylene diisocyanate, etc. Bis isocyanates, or derivatives thereof. Among the isocyanate compounds, those which are water-soluble (water-soluble or water-dispersible) are preferred.

Commercially available products of the isocyanate compound include, for example, Bayhydur 3100, Desmodur DN, and Basonat HW-100, manufactured by BASF Corporation.

<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 an increase in the peeling strength with time, and to exert the adhesiveness of the polyvinyl alcohol itself to the substrate.

The type of polyvinyl alcohol is not particularly limited, but examples thereof include those in which a polymer of vinyl ester is completely or partially saponified. The degree of saponification of polyvinyl alcohol is not particularly limited, for example, it may be 70 mol% or more, but from the viewpoint of operability in the continuous production step of the release sheet, 99 mol% or less is preferable, and 97 mol% or less is preferable Better.

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 production step of the release sheet, 5,000 or less is preferable, and 1,500 or less is more preferable .

If the degree of saponification of polyvinyl alcohol exceeds 99 mol%, or the average degree of polymerization exceeds 5,000, the liquid substance used to form the resin layer may sometimes produce a gel. When a release sheet is continuously manufactured by circulating a liquid substance and coating it on a substrate, the gel system generated by the liquid substance accumulates in the circulation system, which may cause a decrease in continuous operability.

Polyvinyl alcohol, as described later, is preferably water-soluble when used as a liquid.

From the viewpoint of suppressing the increase in peel strength with time, the content of polyvinyl alcohol in the resin layer is preferably 0.1 parts by mass or more relative to 100 parts by mass of the polymer, and more preferably 0.5 parts by mass or more. 1 mass part or more is more preferable. On the other hand, from the standpoint of the release property of the resin layer, the content of polyvinyl alcohol in the resin layer is preferably 1,000 parts by mass or less, and more preferably 500 parts by mass or less with respect to 100 parts by mass of the polymer. It is more preferably 300 parts by mass or less. To satisfy these two viewpoints, the content of polyvinyl alcohol in the resin layer is preferably 0.1 to 1,000 parts by mass, more preferably 0.5 to 500 parts by mass, and 1 to 300 parts by mass relative to 100 parts by mass of the polymer. Mass parts are better.

From the viewpoint of improving transparency (reducing haze), 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. It is more preferably less than or equal to 1,000 parts by mass, and more preferably zero. On the other hand, from the viewpoint of improving the visibility (increasing the haze) of forgetting to peel off the release sheet in the prevention step, the content of polyvinyl alcohol is preferably from 10 parts by mass to 500 parts by mass, and 100 parts by mass Above 400 parts by mass is more preferred.

Commercially available products of polyvinyl alcohol include, for example, "JC-05", "VC-10", "JT-05", "JF-05", "ASC" of "J-POVAL" made by Japan VAM & POVAL Corporation. "-05X", "UMR-10HH"; "Pura-103", "PVA-105" or "EXCEVAL" "AQ4104", "HR3010" by "Kuraray Poval" manufactured by KURARAY; "PC-1000" and "PC-2000" of "Denka Poval".

In the present invention, the resin layer of the release sheet A range of effects can be included in the lubricant. Examples of the lubricant include inorganic compounds such as calcium carbonate, magnesium carbonate, calcium oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconia, barium sulfate, tin oxide, antimony trioxide, and molybdenum disulfide. Particles, or organic particles such as acrylic cross-linked polymers, styrene-based cross-linked polymers, silicone resins, fluororesins, benzoguanamine resins, phenol resins, nylon resins, polyethylene waxes, surfactants, and the like. In addition, various agents such as antioxidants, antistatic agents, and ultraviolet absorbers, or pigments or dyes such as titanium oxide, carbon black, and zinc oxide may be added as necessary.

<Resin layer>

The release sheet of the present invention is such that when the resin layer of the release sheet is superimposed on the substrate surface of another release sheet, the dynamic friction coefficient must be 0.50 or less, preferably 0.45 or less, and more preferably 0.40 or less. . If the dynamic friction coefficient exceeds 0.50, when the release sheet is wound around the core, the slippage between the resin layer and the substrate surface is low, so it is easy to produce winding deviation, and wrinkles, bends, unevenness, etc. are caused in the release sheet. Not only may the yield of the release sheet be reduced, but also the damage resistance of the resin layer may be reduced, which may affect the surface shape of the adherend after peeling. The coefficient of dynamic friction can be controlled by the material forming the resin layer. If it contains two or more types of polymers in the resin layer, or the content of the (meth) acrylate component in the resin layer is within a preferred range, the coefficient of dynamic friction has The tendency to get smaller.

In the release sheet of the present invention, a sample obtained by attaching the aforementioned adhesive layer of a resin tape having an acrylic adhesive layer to the surface of the resin layer of the release sheet was peeled at 180 ° at 25 ° C. The peeling of the adhesive layer and the resin layer when measuring the conditions of the peeling speed of 300mm / min The strength must be 0.5 N / cm or less, more preferably 0.3 N / cm or less, more preferably 0.2 N / cm or less, and even more preferably 0.15 N / cm or less. When the peel strength of the acrylic adhesive material exceeds 0.5 N / cm, resistance is felt when the release sheet is peeled from the adhesive material, or the adhesive material is sometimes rough due to the rough surface, and the adhesiveness is sometimes reduced, so it is difficult to use it as acrylic acid. Release sheet for adhesive materials.

In addition, the release sheet of the present invention can also be used for a silicone-based adhesive material which is a typical adhesive material having a strong adhesive force. If a silicone-based release sheet such as the conventional one is used for the silicone-based adhesive material, since the adhesive layer and the release layer have high affinity, the adhesiveness is high and it is difficult to peel off. In contrast, the release sheet of the present invention can maintain good peelability even with a silicone adhesive material.

The release sheet of the present invention is excellent in heat resistance, so the adhesive material to which the release sheet is attached during the storage and circulation process, even if exposed at high temperature for a long time, the peel strength does not change with time. After a long time, the change in the peel strength of the resin layer and the adhesive material can be suppressed to a small extent.

In addition, in the step of industrially releasing the release sheet, along with the increase in the speed of the production line, generally, in order to release the release sheet at a speed exceeding 10 m / min, a release sheet that can be peeled off from the adhesive at a high speed is required. Since the release sheet of the present invention has sufficient release properties, even if it is peeled from the adhesive material at a high speed, it can be peeled off without sound and resistance. That is, when the release sheet of the present invention is peeled at a high speed, it can suppress the surface state of the adhesive material from being roughened due to the phenomenon of a so-called zipping or stick slip sound, thereby leading to transparency. Or the case of reduced adhesion.

In order to prevent forgetting to peel off the release sheet in the step, from the viewpoint of visibility, the haze (Hz) of the release sheet of the present invention is preferably 3.5% or more, more preferably 4.5% or more, and Above 5.5% is even better. On the other hand, from the viewpoint of irradiation efficiency when a photosensitive resin is applied to the release sheet and light is irradiated from the release sheet, the haze is preferably less than 3.5%, and more preferably 3.0% or less. It is 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 substrate, and selecting the constituent components and thickness of the resin layer, and in particular, it can be adjusted according to the content of polyvinyl alcohol in the resin layer.

In the present invention, the resin layer of the release sheet is preferably soft. When the resin layer is made soft, the release property of the release sheet tends to be better.

The softness index is not particularly limited, and examples thereof include storage elasticity, loss of elasticity, Vickers hardness, Marutens hardness, Rockwell hardness, Shore hardness, Knoop hardness, and pencil hardness. Hardness measured according to the nanoindentation method.

<Substrate>

The base material constituting the release sheet of the present invention may be, for example, a resin material, paper, synthetic paper, cloth, metal material, glass material, or the like. The thickness of the substrate is not particularly limited, but usually it is only 1 to 1000 μm, preferably 1 to 500 μm, more preferably 10 to 200 μm, and particularly preferably 25 to 100 μm.

Resin materials that can be used for the substrate, such as thermoplastic resins, include, for example, polyethylene terephthalate (PET), polyethylene naphthalate Polyester resins such as esters (PEN) and polylactic acid (PLA); Polyolefin resins such as polypropylene; Polystyrene resins; Polyamide resins such as nylon 6, poly-m-xylylene hexamethylene diamine (MXD6 nylon) Polycarbonate resin; polyacrylonitrile resin; polyimide resin; multilayer bodies of these resins (e.g. nylon 6 / MXD6 nylon / nylon 6, nylon 6 / ethylene-vinyl alcohol copolymer / nylon 6) or mixed体 等。 Body and so on.

The resin material can be stretched. Among them, the substrate is preferably a polyester resin film excellent in mechanical properties and thermal properties. From the viewpoint of being inexpensive and easy to obtain, a polyethylene terephthalate film is preferred.

<Manufacturing method>

The release sheet of the present invention can be easily produced industrially by a method in which a polymer containing an olefin component and an unsaturated carboxylic acid component as a copolymerization component is contained in a liquid medium. A method for applying a substance to a substrate, and drying, stretching, and heat-treating the substrate coated with the liquid substance to form a resin layer.

In the present invention, the liquid medium constituting the liquid material for forming a resin layer is preferably an aqueous medium. The aqueous medium means a solvent containing water and an amphiphilic organic solvent, and the content of water is 2% by mass or more, and may be only water.

The amphiphilic organic solvent refers to an organic solvent in which the solubility of water in an organic solvent at 20 ° C is 5% by mass or more. (The solubility of water in an organic solvent at 20 ° C is described in, for example, the "Solvent Handbook" (Kodansha Scientific , 10th edition of 1990) and other literature).

Specific examples of the amphiphilic organic solvent include alcohols such as methanol, ethanol, n-propanol, and isopropanol, tetrahydrofuran, and Ethers such as alkane, ketones such as acetone, methyl ethyl ketone, methyl acetate, ethyl acetate-n-propyl acetate, isopropyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, etc. Ethylene glycol derivatives such as butyl ether, others include organic amines such as diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, and N, N-diethylethanolamine. Compounds, lactams such as 2-pyrrolidone, N-methyl-2-pyrrolidone and the like.

The polymer-containing liquid material for forming a resin layer may contain a crosslinking agent or polyvinyl alcohol.

As the liquid system of the polymer, an aqueous dispersion can be used. The method for dispersing the polymer in water is not particularly limited, and examples thereof include a method described in International Publication No. 02/055598.

The dispersed particle size of the polymer in the aqueous medium is from the point of stability when mixed with other components and storage stability after mixing. The number average particle diameter is preferably 1 μm or less, and more preferably 0.8 μm or less. good. Such a particle size can be achieved in accordance with the manufacturing method described in International Publication No. 02/055598. The number average particle diameter of the polymer was measured by a dynamic light scattering method.

The solid content concentration of the aqueous dispersion of the polymer is not particularly limited, but in order to properly maintain the viscosity of the aqueous dispersion, 1 to 60% by mass is preferable, and 5 to 30% by mass is more preferable.

The solid content concentration of the liquid material for forming a resin layer obtained by mixing a liquid material of a polymer with a crosslinking agent or polyvinyl alcohol may be appropriately selected depending on the conditions of the lamination, the thickness of the purpose, and performance, and is not particularly limited. . However, in order to moderately maintain the viscosity of the liquid and form a uniform resin layer, 1 to 30% by mass is more preferable, and 2 to 20% by mass is more preferable.

Additives such as leveling agents, defoamers, deodorants, and wetting agents can be added to the resin layer forming liquid in a range that does not impair its performance.

In the present invention, the method for applying the above-mentioned liquid material for forming a resin layer to a substrate may be a known method, such as gravure roll coating, reverse roll coating, wire rod coating, die lip coating, and air knife. Coating, curtain coating, spray coating, dip coating, and blade coating.

In the present invention, when the liquid material for forming a resin layer is applied to a thermoplastic resin film as a base material, it is preferable to include a step of applying the liquid material for forming a resin layer in a manufacturing step of the base material film, And the steps of drying, directional stretching and heat fixing together with the substrate film. By coating in the manufacturing step, the resin layer can be formed in a state where the degree of directional crystallization on the surface of the substrate film is small, so the adhesion between the substrate film and the resin layer is improved. In addition, since the resin layer can be heat-treated at a higher temperature in a state where the base film is stretched, it is possible to improve release properties and residual adhesion without reducing the quality of the base film. In addition, compared with coating when leaving the production line, not only the manufacturing steps can be simplified, but the thinning of the resin layer is also advantageous in terms of cost. Further, when the sequential biaxial stretching method is used, it is preferable to apply the aforementioned liquid substance to a substrate film stretched in a uniaxial direction for reasons of simplicity or operation, so that the liquid substance is applied. The substrate film is dried, and thereafter, the substrate film is further extended in a direction orthogonal to the aforementioned direction, and is subjected to heat treatment.

<Use>

The release sheet of the present invention is also suitable for use as an engineering material of prepreg. For example, it can be suitably used as a mounting sheet when a solution containing a resin such as an epoxy resin or a phenol resin and a hardener is applied and dried to form a sheet.

Since the release sheet of the present invention also has heat resistance, the release property can also be maintained after the high temperature treatment in the hardening step. In order to improve the reinforcement effect, the prepreg can be reinforced with fabrics such as carbon fiber or glass fiber. The steps of using the prepreg include, for example, a stamping step of a printed wiring board, a forming step of a structural member such as an airplane, a bicycle, a windmill, and a forming step of a sporting and leisure article such as a golf club and a tennis racket. Examples of the printed wiring board include a single-sided printed wiring board, a double-sided printed wiring board, a flexible printed wiring board, and a multilayer printed wiring board.

Examples of sheet-like structures that can be manufactured using the release sheet of the present invention as a base substrate include rubber sheets such as silicone rubber, fluorine rubber, and urethane rubber, and vinyl chloride or urethane. Synthetic leather made of esters, ion-exchange membranes made of polymer electrolytes such as perfluorosulfonic acid resins, ceramic green sheets made of dielectric ceramics or glass, heat sinks containing heat sinks, etc.

In these manufacturing steps, the release sheet that is the base material of the present invention can be coated with a solvent to form a paste-like or slurry-like raw material and dried to form a sheet-like structure. Alternatively, the molten resin may be extruded on a release sheet to form a sheet-like structure.

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 on the release sheet of the present invention, and the functional layers on the release sheet are paired. Into the body After heating and pressure bonding, the functional layer is transferred on the transferee, and then the release sheet is peeled from the functional layer. In this way, the release sheet of the present invention can also be used for stamping foil. The functional layer may be, for example, a metal foil, a pigment foil, a multicolor printing foil, a hologram foil, an electrostatic destruction foil, a semi-mirror metal foil, or the like.

[Example]

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited thereto.

(1) Unsaturated carboxylic acid content in the polymer

Infrared absorption spectrum analysis (Fourier transform infrared spectrophotometer System-2000 manufactured by Perkin Elmer, analysis energy 4 cm ^-1 ), the content of unsaturated carboxylic acid components in the polymer was determined.

(2) Composition of polymers other than unsaturated carboxylic acid components

¹ H-NMR and ¹³ C-NMR analysis (manufactured by Japan Electronics Co., Ltd., 500 MHz) were performed at 120 ° C in o-dichlorobenzene (d ₄ ), and the results were obtained. ¹³ C-NMR analysis is based on quantitative gating decoupling.

(3) Number average molecular weight

A GPC analysis (manufactured by TOSOH Corporation, HLC-8020, and column TSK-GEL) was used to dissolve the sample in tetrahydrofuran and measure at 40 ° C. The number average molecular weight was obtained from a calibration curve made of a polystyrene standard sample. When it is difficult to dissolve in tetrahydrofuran, o-dichlorobenzene is used.

(4) Melt flow rate

JIS K7210: Measured at 190 ° C under a load of 2160 g according to the method described in 1999.

(5) Solid content concentration of aqueous dispersion

An appropriate amount of the polymer aqueous dispersion was weighed, and this was heated at 150 ° C. until the mass of the residue (solid content) reached a constant amount, and the solid content concentration was determined.

(6) Content of olefin component, unsaturated carboxylic acid component, (meth) acrylate component in the resin layer

The polyethylene terephthalate resin constituting the base material of the obtained release sheet was dissolved by hexafluoroisopropanol (HFIP), and only the resin layer was separated. The separated resin layer was subjected to solid ¹³ C-NMR analysis (manufactured by Nippon Electronics Co., Ltd., 500 MHz), and was obtained. In the solid ¹³ C-NMR analysis, the DD / MAS method was used for quantitative analysis.

(7) Peel strength (25 ° C)

On the resin layer side of the obtained release sheet, an acrylic adhesive tape (Nitto Denko Corporation, No. 31B / acrylic adhesive) having a width of 50 mm and a length of 150 mm was crimped with a rubber roller, and used as a sample for measuring peel strength. The peeling strength of the adhesive tape and the release sheet of the sample for peeling strength measurement was measured by a tensile tester (Intesco, precision universal material testing machine, Model 2020) in a constant temperature room at 25 ° C. The peeling angle was set to 180 degrees, and the peeling speed was set to 300 mm / minute.

(8) Peel strength (25 ° C-after 24 hours)

On the resin layer side of the obtained release sheet, an acrylic adhesive tape (Nitto Denko Corporation, No. 31B / acrylic adhesive) having a width of 50 mm and a length of 150 mm was pressure-bonded with a rubber roller as a sample. The sample was sandwiched by a metal plate / rubber plate / sample / rubber plate / metal plate, and left in an environment with a load of 2 kPa and 25 ° C for 24 hours to obtain a sample for measuring peel strength. in A 25 ° C thermostatic chamber was used to measure the peel strength of the adhesive tape and the release sheet of the sample for peel strength measurement by a tensile tester (manufactured by Intesco, precision universal material tester, model 2020). The peeling angle was set to 180 degrees, and the peeling speed was set to 300 mm / minute.

(9) Peel strength (70 ° C-after 24 hours)

On the resin layer side of the obtained release sheet, an acrylic adhesive tape (Nitto Denko Corporation, No. 31B / acrylic adhesive) having a width of 50 mm and a length of 150 mm was pressure-bonded with a rubber roller as a sample. The sample was sandwiched by a metal plate / rubber plate / sample / rubber plate / metal plate, and left in an environment of a load of 2 kPa and 70 ° C for 24 hours to obtain a sample for measuring peel strength. The peeling strength of the adhesive tape and the release sheet of the sample for peeling strength measurement was measured by a tensile tester (Intesco, precision universal material testing machine, Model 2020) in a constant temperature room at 25 ° C. The peeling angle was set to 180 degrees, and the peeling speed was set to 300 mm / minute.

(10) Residual adhesion rate

After the peel strength test (7), (25 ° C), (8) peel strength test (25 ° C-after 24 hours), and (9) peel strength test (70 ° C-after 24 hours), A 50 mm width and 150 mm length acrylic adhesive tape (Nitto Denko Corporation, No. 31B / acrylic adhesive) peeled off the surface of the die, each attached to a stainless steel plate (SUS304 thickness 1mm), with a load of 2kPa and placed at room temperature 20 hours. Thereafter, the peeling strength of the acrylic adhesive tape and the stainless steel plate was measured by a tensile tester (manufactured by Intesco, a precision universal material tester, model 2020) in a constant temperature room at 25 ° C. The peeling angle was set to 180 degrees, and the peeling speed was set to 300 mm / minute. The peel strengths obtained by this measurement are respectively F1 ₍₇₎ , F1 _{(8), and} F1 ₍₉₎ .

An acrylic adhesive tape (Nitto Denko Corporation, No. 31B / Acrylic adhesive) with a width of 50 mm and a length of 150 mm was attached to a stainless steel plate (SUS304 thickness 1 mm). A load of 2 kPa was left at room temperature for 20 hours. Thereafter, the peeling strength of the acrylic adhesive tape and the stainless steel plate was measured by a tensile tester (manufactured by Intesco, precision universal material tester, model 2020) in a 25 ° C constant temperature room The peeling angle was 180 degrees and the peeling speed was 300 mm / min.), And the resulting peeling strength was set to F2.

The following formula was used to obtain the residual adhesion rate of each adhesive tape.

Residual adhesion rate after leaving at 25 ℃ (%) = (F1 ₍₇₎ / F2) × 100

Residual adhesion rate after 24 hours at 25 ° C (%) = (F1 ₍₈₎ / F2) × 100

Residual adhesion rate after 24 hours at 70 ° C (%) = (F1 ₍₉₎ / F2) × 100

When the surface of the adhesive layer of the adhesive tape is contaminated by a release sheet, or when the surface of the adhesive tape becomes significantly rough when peeled off, the re-adhesiveness of the adhesive tape will be reduced, and the performance as an adhesive tape will be impaired. Therefore, a higher residual adhesion rate is preferred.

(11) Pressure resistance

The obtained release sheet was cut into two pieces having a size of 50 mm × 50 mm, and superposed so that the resin layer was in contact with the substrate surface. After being left for 24 hours under a load of 10 kPa at 60 ° C., it was removed. After the load was cooled to room temperature, the adhesion state between the resin layer and the substrate surface was investigated, and the pressure resistance was evaluated.

○: Adhesion was not observed on the two sheets, or peeling was simply performed on the two sheets, and no change such as whitening was observed in the resin layer.

△: Adhesion was seen in the two sheets, but no change such as whitening was seen in the resin layer.

×: The resin layer caused aggregation failure, or the resin layer was whitened as a whole after peeling off two sheets.

(12) Dynamic friction coefficient

From the obtained release sheet, the release sheet 1 and the release sheet 2 were cut out, and the resin surface of the release sheet 1 and the base material surface of the release sheet 2 were superimposed so that the contact area became 40 cm ² , and measured in accordance with JIS K7125 Coefficient of dynamic friction.

(13) Haze (Hz)

The haze of the obtained release sheet was measured using a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136.

(14) Continuous operability

In Examples 2, 5 to 6, 14, 16 to 19, 21 to 28, and Comparative Example 5, the operability when manufacturing a release sheet for 24 hours was evaluated. That is, the liquid pan containing the aqueous coating agent is connected to a circulation system composed of a liquid feed pump and a filter box (TCW-10N-PPS (nominal pore size: 10 μm) manufactured by Advantech Toyo Corporation), and the pressure is 0.2 MPa. When gravure coating is performed while the liquid is being fed, the number of filters exchanged with the clogging of the filter mesh is evaluated for continuous operability.

○: Filter exchange 0 times

△: Filter exchange once

×: filter exchange more than 2 times

The following was synthesized as a polymer constituting the resin layer, and then a commercially available polymer was included to produce each aqueous dispersion.

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 melted in 470 g of xylene in a nitrogen atmosphere in a 4-necked flask, and the temperature in the system was maintained at 140 ° C. Under stirring, 60 g of maleic anhydride as an unsaturated carboxylic acid and 30 g of dicumyl peroxide as a radical generator were added, and then reacted 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 several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-1 composed of an acid-modified α-olefin / ethylene copolymer.

Synthesis Example 2: Polymer P-2

In Synthesis Example 1, except that a propylene / ethylene copolymer (number average molecular weight = 8,100) with a mass ratio (propylene / ethylene) of 56.9 / 43.1 was used, the amount of maleic anhydride was changed to 30 g, and dicumyl The amount of peroxide was changed to 25 g, and the rest was a polymer P-2 composed of an acid-modified α-olefin / ethylene copolymer obtained by the same operation and synthesized.

Synthesis Example 3: Polymer P-3

In Synthesis Example 1, the same procedure was performed except that a propylene / ethylene copolymer (number average molecular weight = 5,200) with a mass ratio (propylene / ethylene) of 57.3 / 42.7 was used, and the amount of maleic anhydride was changed to 20 g. The polymer P-3 composed of an acid-modified α-olefin / ethylene copolymer was synthesized by operation.

Synthesis Example 4: Polymer P-4

Propylene / ethylene copolymer (mass ratio: propylene / ethylene = 64.8 / 35.2) 280g was heated and melted in 470g of xylene in a nitrogen atmosphere in a 4-necked flask, and the temperature in the system was maintained at 140 ° C. After stirring, it took 2 hours to add 30g of maleic anhydride and 25g of dicumyl peroxide. Allow 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 several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-4 composed 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 nitrogen environment in a 4-neck flask, and thereafter, the temperature in the system was maintained At 170 ° C, 32 g of maleic anhydride and 6 g of dicumyl peroxide were respectively added under stirring for 1 hour, 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 several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-5 composed 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. under a nitrogen environment in a 4-neck flask. Then, 5 g of a toluene solution (10% by mass) and 5 g of a toluene solution (10% by mass) of dicumyl peroxide were added to the solution over 30 minutes, respectively. Thereafter, the inside of the system was maintained at 130 ° C. And allowed to react for 4 hours. After completion of the reaction, the obtained reactant was put into a large amount of acetone to precipitate a resin. The resin was further washed several times with acetone to remove unreacted After maleic anhydride, it was dried under reduced pressure to synthesize a polymer P-6 composed 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 nitrogen atmosphere in a 4-neck flask. Then, the inside of the system was maintained at 170 ° C, and 10 g of maleic anhydride and 6 g of dicumyl peroxide were added over 1 hour under stirring, respectively, 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 several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure to synthesize a polymer P-7 composed 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 sealable pressure-resistant 1L glass container with a heater, the glass container was filled with 45.0 g of polymer P-1, 93.0 g of tetrahydrofuran, 2.0 g of cyclohexane, and 30.6 g of Triethylamine and 129.4 g of distilled water were stirred with the rotation speed of the stirring blade set to 300 rpm. While maintaining this state, the heater was powered on and heated to keep the temperature in the system at 110 ° C and stirred for 60 minutes. After that, the water bath was attached and stirred, and while cooling to room temperature (about 25 ° C.), 165.0 g of distilled water and 3.2 g of N, N-dimethylethanolamine (hereinafter, DMEA) were added. The obtained aqueous dispersion was placed in a 1 L eggplant-type flask, and an evaporator was used under reduced pressure while attaching a heat bath heated to 60 ° C., and 243.2 g of an aqueous medium was distilled off. After cooling, the liquid components in the flask were filtered under pressure (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white color. The homogeneous polymer P-1 is an aqueous dispersion E-1.

Production Example 2: Aqueous dispersion E-2 of polymer P-2

Using a mixer equipped with a sealable pressure-resistant 1L glass container with a heater, the glass container was filled with 54.0 g of polymer P-2, 57.6 g of isopropyl alcohol, 33.9 g of triethylamine, and 154.5. g of distilled water, set the rotation speed of the stirring blade to 300 rpm, and stir. While maintaining this state, the heater was powered on and heated to keep the temperature in the system at 120 ° C and stirred for 60 minutes. After that, a water bath was attached and stirred, and while cooling to room temperature (about 25 ° C), 176.7 g of distilled water was added. The obtained aqueous dispersion was placed in a 1-L eggplant-type flask, and an evaporator was used under reduced pressure while attaching a heat bath heated to 60 ° C., and 206.7 g of an aqueous medium was distilled off. After cooling, the liquid components in the flask were filtered under pressure (air pressure 0.2 MPa) with a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform polymer P-2 aqueous dispersion E. -2.

Production Example 3: Aqueous dispersion E-3 of polymer P-3

Using a stirrer equipped with a sealable pressure-resistant 1L glass container with a heater, the glass container was filled with 45.0 g of polymer P-3, 90.9 g of tetrahydrofuran, 2.1 g of cyclohexane, and 9.0 g of Triethylamine and 153.0 g of distilled water were stirred with the rotation speed of the stirring blade set to 300 rpm. While maintaining this state, the heater was powered on and heated to keep the temperature in the system at 110 ° C and stirred for 60 minutes. After that, a water bath was attached and stirred, and while cooling to room temperature (about 25 ° C.), 55.2 g of distilled water and 7.9 g of DMEA were added. The obtained aqueous dispersion was placed in a 1-liter eggplant-shaped flask, and the evaporator was decompressed using an evaporator while attaching a heat bath heated to 60 ° C., and distilled off. 138.1 g of aqueous medium. After cooling, the liquid components in the flask were filtered under pressure (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform polymer P-3 aqueous dispersion E. -3.

Production Example 4: Aqueous dispersion E-4 of polymer P-4

Except that the polymer P-4 was used in Production Example 2, the same operation was performed to obtain a milky-white uniform dispersion P-4 of the polymer P-4.

Production Example 5: Aqueous dispersion E-5 of polymer P-5

Using a mixer equipped with a sealed, pressure-resistant 1L glass container with a heater, the glass container was filled with 45.0 g of polymer P-5, 105.0 g of tetrahydrofuran, 3.0 g of cyclohexane, and 9.0 g of DMEA and 138.0 g of distilled water were stirred with the rotation speed of the stirring blade set to 300 rpm. While maintaining this state, power on the heater and heat it to keep the temperature in the system at 125 ° C and stir for 60 minutes. After that, a water bath was attached and stirred, and while cooling to room temperature (about 25 ° C.), 80.0 g of distilled water was added. The obtained aqueous dispersion was placed in a 1-L eggplant-type flask, and an evaporator was used under reduced pressure while attaching a heat bath heated to 60 ° C., and 155.0 g of an aqueous medium was distilled off. After cooling, the liquid components in the flask were filtered under pressure (air pressure 0.2 MPa) with a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform polymer P-5 aqueous dispersion E. -5.

Production Example 6: Aqueous dispersion E-6 of polymer P-6

By mixing 25.0 g of polymer P-6 and 4,975 g of tetrahydrofuran, heating, and stirring, a P-6 solution having a P-6 content of 0.5% by mass was prepared.

Then, 10,000 g of distilled water was charged into a container equipped with a stirrer and a heater, and while stirring with the stirrer, 5,000 g of the aforementioned P-6 solution was slowly added over 5 minutes to prepare a solution composed of distilled water and a P-6 solution. Aqueous dispersion. At this time, the aqueous dispersion polyolefin resin is uniformly dispersed (uniformly cloudy).

The obtained aqueous dispersion was heated to 60 ° C. with a heater and stirred directly, and the pressure in the container was gradually reduced. The tetrahydrofuran and water vapor generated by heating and decompression are condensed outside the container and distilled off to the outside of the container. When the mass of the aqueous dispersion in the container became 200 g or less, the aqueous dispersion was filtered under pressure by a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave). No undispersed matter was left on the filter after filtration. Distilled water was added to the filtered aqueous dispersion to adjust the solid content concentration to 10% by mass. In this way, an aqueous dispersion E-6 of a milky white uniform polymer P-6 was obtained.

Production Example 7: Aqueous dispersion E-7 of polymer P-7

Except for using polymer P-7 in Production Example 5, the same operation was performed to obtain a milky white uniform dispersion P-7 of polymer P-7.

Production Example 8: Aqueous dispersion E-8 of polymer P-8

Using a mixer equipped with a sealed, pressure-resistant 1L glass container with a heater, 60.0 g of polymer P-8 (made by Arkema, BONDINE LX-4110, mass ratio) made of acid-modified polyethylene resin was used. : Ethylene / acrylic acid ester / maleic anhydride = 91/7/2), 75.0g of n-propanol, 2.5g of triethylamine and 162.5g of distilled water are filled into a glass container, and the stirring wings The rotation speed was set to 300 rpm and stirred. No pellet of resin pellets was observed at the bottom of the container, and it was confirmed that the resin was in a floating state. Therefore, while maintaining this state, at the same time 10 minutes later, the power of the heater was turned on and heated, and then the temperature in the system was maintained at 120 ° C. and further stirred for 30 minutes. After that, the water bath was attached and stirred, and while cooling to room temperature (about 25 ° C.), 147.8 g of distilled water and 2.2 g of DMEA were added. The obtained aqueous dispersion was placed in a 1-L eggplant-type flask, and an evaporator was used under reduced pressure while attaching a heat bath heated to 60 ° C., and 155.0 g of an aqueous medium was distilled off. After cooling, the liquid components in the flask were filtered under pressure (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weaving) to obtain a milky white uniform polymer P-8 aqueous dispersion E. -8.

Production Example 9: Aqueous dispersion E-9 of polymer P-9

Using a mixer equipped with a sealable pressure-resistant 1L glass container with a heater, 60.0 g of polymer P-9 (made by Dow Chemical Co., Primacor 5980I, made of acid-modified polyethylene resin), mass ratio: Ethylene / acrylic acid = 80/20), 16.8 g of triethylamine, and 223.2 g of distilled water were charged into a glass container, and the rotation speed of the stirring blade was set to 300 rpm and stirred, and no resin particles were visible at the bottom of the container. It was confirmed that it was floating. Therefore, while maintaining this state, at the same time after 10 minutes, the power of the heater was turned on and heated, and then the temperature in the system was kept at 120 ° C. and further stirred for 40 minutes. After that, it was cooled with air and stirred at a rotational speed of 300 rpm. At the same time, it was cooled to room temperature (approximately 25 ° C), and then filtered with 300 mesh stainless steel filters (wire diameter 0.035 mm, plain weave) under pressure (air pressure 0.2MPa) to obtain an aqueous dispersion of slightly cloudy polymer P-9 E-9.

Table 1 shows the composition, characteristics, and solid content concentration of the aqueous dispersion of the polymer.

As the cross-linking agent constituting the resin layer, polyvinyl alcohol was used as follows.

WS700: Oxazoline compound (manufactured by Japan Catalyst Co., Ltd., EPOCROSWS-700)

WS500: Oxazoline compounds (manufactured by Nippon Catalytic Corporation, EPOCROSWS-500)

E-02: carbodiimide compound (manufactured by Nisshinbo, Carbodilite E-02)

EM-051R: epoxy compound (manufactured by Adeka, Adeka resin EM-051R)

HW-100: Isocyanate compound (Basonat HW-100, manufactured by BASF)

VC-10: Polyvinyl alcohol (manufactured by Japan VAM & POVAL, VC-10, saponification degree of 99.3 mol% or more, average polymerization degree of 1,000)

JT-05: Polyvinyl alcohol (manufactured by Japan VAM & POVAL, JT-05, saponification degree 93.5 to 94.5 mole%, average polymerization degree 500)

JF-05: Polyvinyl alcohol (manufactured by Japan VAM & POVAL, JF-05, saponification degree 98.0 to 99.0 mole%, average polymerization degree 500)

Example 1

P-1 as a polymer (A) composed of an acid-modified α-olefin / ethylene copolymer is 50 parts by mass, and P-8 as a polymer (B) composed of an acid-modified polyethylene resin An aqueous coating agent prepared by mixing the respective aqueous dispersions with 50 parts by mass, 10 parts by mass of a cross-linking agent, and 10 parts by mass of polyvinyl alcohol, was applied on a biaxial shaft using a corner wheel coater. After the corona-treated surface of the polyester resin film (Emblet PET-38 manufactured by Unitika, thickness of 38 μm, and one-sided corona treatment) was stretched, it was dried at 140 ° C. for 15 seconds. After a resin layer having a thickness of 0.2 μm was formed on the film, it was cured at 50 ° C. for 2 days to obtain a release sheet.

Examples 3 to 4, 7 to 13, 15, 20, 29 to 30, and Comparative Examples 1 to 4, 6

A water-based coating agent was prepared in the same manner as in Example 1 except that the types and parts by mass of the polymers (A), (B), crosslinking agent, and polyvinyl alcohol were changed to those shown in Tables 2 and 4. Release film.

Example 2

A polyethylene terephthalate resin (manufactured by Japan's Ester Co., Ltd., with an inherent viscosity of 0.6) was extruded with a T die (75mm diameter, slow compression type uniaxial screw with L / D of 45), and a cylinder barrel. The temperature was 260 ° C and the temperature of the T die was 280 ° C. It was extruded into a sheet shape, and it was brought into close contact with a cooling roller adjusted to a surface temperature of 25 ° C to be rapidly cooled to become an unstretched film with a thickness of 500 μm. Then, it was stretched 3.4 times in the longitudinal direction at 90 ° C, and then the aqueous coating agent prepared in Example 1 was coated with a gravure coater to obtain a dry and stretched coating amount of 0.2 g / m ² . Next, after preheating at a temperature of 90 ° C. for 2 seconds, it was extended at 240 ° C. in the horizontal direction at a magnification of 3.0 times to obtain a release sheet. The thickness of the obtained polyester film and the resin layer was 50 μm.

Examples 5 to 6, 14, 16 to 19, 21 to 28, and Comparative Example 5

Except for coating the water-based coating agent prepared by changing the types and mass parts of the polymers (A), (B), crosslinking agent, and polyvinyl alcohol to those shown in Tables 2 and 4, the rest are the same as in Example 2. In the same manner, a release sheet was obtained.

Evaluation of the release films obtained in the examples and comparative examples The results are shown in Tables 3 and 5.

The kinetic coefficient of friction of the release sheet resin layer obtained in Examples 1 to 30 is 0.50 or less, the kinetic friction coefficient is low, and the peel strength with the acrylic adhesive at 25 ° C is 0.5N / cm or less, and the release property is excellent. Moreover, the release property after heating is also excellent. In addition, the peeled adhesive material maintains a high residual adhesion rate.

The content of the (meth) acrylic acid ester component in the resin layer is in a particularly preferred range, and the release sheet of the example containing two types of polymers has a value with a small dynamic friction coefficient. In addition, the resin layer contains polyethylene having a better degree of saponification. The enol release sheet is excellent in continuous operability.

On the other hand, the release sheets of Comparative Examples 1 and 6 had high dynamic friction coefficients and poor productivity.

In the release sheets of Comparative Examples 2 to 5, since the mass ratio of the α-olefin component / ethylene component in the resin layer exceeded the range specified in the present invention, any of the release properties were inferior.

Claims (9)

A release sheet is formed by providing a resin layer on a substrate. The resin layer contains one or more polymers containing an olefin component and an unsaturated carboxylic acid component as a copolymerization component. The olefin component contains an α-olefin component and The mass ratio of ethylene component, α-olefin component to ethylene component (α-olefin component / ethylene component) in the resin layer is 10/90 to 60/40, and the dynamic friction coefficient when the resin layer and the substrate surface are superimposed is 0.50 Hereinafter, a sample obtained by bonding the aforementioned adhesive layer of a resin tape having an acrylic adhesive layer to the surface of the resin layer of a release sheet was measured at 25 ° C under conditions of a peel angle of 180 degrees and a peel speed of 300 mm / minute. The peel strength of the adhesive layer and the resin layer is 0.5 N / cm or less. The release sheet according to item 1 of the patent application scope, wherein the polymer contains a (meth) acrylate component as a copolymerization component. The release sheet according to item 2 of the scope of patent application, wherein the content of the (meth) acrylate component in the resin layer is 0.1 to 15% by mass. The release sheet according to any one of claims 1 to 3, wherein the content of the unsaturated carboxylic acid component in the resin layer is 0.1 to 15% by mass. The release sheet according to any one of claims 1 to 4, wherein the resin layer contains The content of the crosslinking agent in the resin layer is 0.1 to 50 parts by mass based on 100 parts by mass of the polymer of the crosslinking agent composed of the oxazoline compound and / or the carbodiimide compound. The release sheet according to any one of claims 1 to 5, wherein the resin layer contains polyvinyl alcohol, and the content of the polyvinyl alcohol in the resin layer is 0.1 to 100 parts by mass of the polymer. 1000 parts by mass. The release sheet according to item 6 of the scope of patent application, wherein the saponification degree of polyvinyl alcohol is 99 mol% or less. A manufacturing method of a release sheet is used for manufacturing the release sheet described in item 1 of the scope of patent application. The manufacturing method is a method in which a liquid material containing a polymer is coated on a substrate to form a resin layer, and the polymer layer contains a polymer. The liquid material includes a polymer (A) composed of an acid-modified α-olefin / ethylene copolymer, a polymer (B) composed of an acid-modified polyethylene resin, and an aqueous medium. The method for producing a release sheet according to item 8 of the scope of patent application, wherein the mass ratio of the α-olefin component to the ethylene component in the polymer (A) composed of an acid-modified α-olefin / ethylene copolymer (α-olefin component / ethylene component) is 40/60 to 80/20, but excludes 40/60.