JP5514066B2 - Release agent, release material and adhesive tape - Google Patents

Description

  The present invention relates to a release agent using polyolefin and having excellent substrate adhesion and a release material using the same, and further relates to an adhesive tape having the release material.

  The release material is a material that has a release agent layer on at least one side of a substrate such as paper, plastic film, or plastic laminated paper, and is used to protect the adhesive surface of adhesive tapes, adhesive sheets, labels, etc. It is used in the manufacturing process of ceramic green sheets.

  Types of release agents include silicone release agents, long-chain alkyl release agents, polyolefin release agents, fluorine release agents, and the like, which are properly used depending on the application. Of these, non-silicone release agents such as polyolefin release agents are used because silicone release agents may cause corrosion or malfunction due to the generation of siloxane gas when used in precision applications such as those related to electronic components. ing.

  Patent documents 1-3 are mentioned as a mold release material using a polyolefin-type release agent. Among these, Patent Documents 1 and 2 propose a release material obtained by applying a polyolefin dissolved in an organic solvent to a substrate and drying it. However, with this release material, although a peeling force corresponding to the original peelability of the polyolefin can be obtained, there is a problem in the adhesion to the base material, and the release agent layer can be easily removed by rubbing with a finger or the like. It was not obtained.

  Patent Document 3 proposes a release material in which a modified polyolefin having a functional group and an isocyanate-based crosslinking agent are used to crosslink the polyolefin, and a release material in which an unmodified polyolefin having no functional group is used in combination. In addition, it is described that a release material having improved solvent resistance, heat resistance and adhesion to a substrate can be obtained. However, as described in paragraph [0010], the release material of Patent Document 3 uses a material having a functional group as the polyolefin, and compatibilizes and crosslinks with the polyolefin as the isocyanate-based crosslinking agent. Therefore, when the release material is stored in a state of being bonded to the adhesive tape, these components act on the components in the pressure-sensitive adhesive, and the peeling force tends to increase depending on the storage conditions. When stored at a temperature of ˜70 ° C. or higher, the peel force tends to increase.

JP-A-55-152775 JP-A-6-99551 Japanese Patent Laid-Open No. 2004-91776

  In view of the above circumstances, the problem to be solved by the present invention is to have a release agent that is excellent in substrate adhesion and maintains the original release property of polyolefin, a release material using the release agent, and further the release material. It is to obtain an adhesive tape.

  As a result of intensive studies to solve the above problems, the present inventors have at least a polyolefin, an alicyclic isocyanate having three or more isocyanate groups in one molecule, and a polyolefin polyol having a number average molecular weight of 1500 to 5000. When the composition is applied as a release agent to a substrate, it is divided into a layer mainly composed of polyolefin and a layer mainly composed of alicyclic isocyanate. The present inventors have found that a release agent layer in an unevenly distributed state can be formed between a main layer and a base material, and have further advanced research based on such knowledge, thereby completing the present invention.

That is, the present invention is as follows.
(1) A release agent containing at least a polyolefin, an alicyclic isocyanate having 3 or more isocyanate groups in a molecule, and a polyolefin polyol having a number average molecular weight of 1500 to 5000.
(2) The release agent according to (1), wherein the alicyclic isocyanate is a polyhydric alcohol adduct of alicyclic diisocyanate.
(3) The release agent according to any one of (1) and (2), wherein the content of the alicyclic isocyanate is 0.5 to 20 parts by weight with respect to 100 parts by weight of the polyolefin.
(4) A mold release material having a release agent layer made of the release agent according to any one of (1) to (3) on at least one side of the substrate.
(5) An adhesive tape having the release material according to (4) on at least one side of the adhesive layer.
(6) A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on one side of the substrate, and having a release agent layer made of the release agent according to any one of (1) to (3) on the other side of the substrate.

According to the release agent of the present invention, it is possible to realize a release material that is excellent in substrate adhesion and that maintains the original peelability of polyolefin.
Moreover, by forming a release agent layer made of the release agent of the present invention on one side opposite to the one side having the adhesive layer of the base material, an adhesive tape having excellent self-releasability can be obtained. .

1 is a transmission electron microscope (TEM) photograph of a cross section of a release agent layer in a release material produced in Example 1. FIG. FIG. 2 is a view showing the results of depth direction X-ray photoelectron spectroscopy (XPS) analysis of the release agent layer in the release material produced in Example 1. FIG. In the figure, arrow a indicates carbon derived from the release agent and the substrate (polyester film), arrow b indicates oxygen derived from the release agent and the substrate (polyester film), and arrow c indicates isocyanate in the release agent. Nitrogen from origin is shown.

1. Release Agent The present invention provides a release agent containing at least a polyolefin, an alicyclic isocyanate having 3 or more isocyanate groups in one molecule, and a polyolefin polyol having a number average molecular weight of 1500 to 5000.

[Polyolefin]
As the polyolefin in the present invention, any polyolefin can be used as long as it can be dissolved in an organic solvent together with other materials and applied to a substrate, but from the viewpoint of solubility in an organic solvent, it has a low density. Polyolefin is preferred.

Specifically, preferably has density of 0.885 g / cm ³ or less, are more preferably 0.880 g / cm ³ or less. If the density exceeds 0.885 g / cm ³ , the solubility in an organic solvent tends to be low, and application to a substrate tends to be difficult, and the peelability tends to decrease. The lower limit is not particularly limited, but is preferably 0.830 g / cm ³ or more.

  As such low density polyolefin, for example, an α-olefin copolymer having at least two kinds selected from the group consisting of ethylene, propylene and an α-olefin having 4 to 20 carbon atoms as monomer units. Among them, a copolymer having ethylene as a main monomer unit (that is, an ethylene-based α-olefin copolymer) and / or a copolymer having propylene as a main monomer unit (that is, Propylene-based α-olefin copolymer) is preferred. Here, as the α-olefin having 4 to 20 carbon atoms, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1- Examples include pentene, 1-heptene, 1-octene, 1-decene, and 1-dodecene. The α-olefin copolymer may be any of a random copolymer, a block copolymer, and a graft copolymer.

The ethylene-based α-olefin copolymer preferably has an ethylene unit of 50 to 95 mol%, more preferably 70 to 95 mol%, and monomer units other than ethylene include 1-butene, propylene, One or more selected from 1-hexene and 1-octene are preferred. The density is preferably 0.857 to 0.885 g / cm ³ . Particularly preferred copolymers include ethylene-1-butene copolymer and ethylene-propylene copolymer. The ethylene-1-butene copolymer may contain a monomer unit derived from α-olefin other than ethylene and 1-butene in an amount of 10 mol% or less. The ethylene-propylene copolymer is The monomer unit derived from (alpha) -olefins other than ethylene and propylene may be contained in the quantity of 10 mol% or less. Such a copolymer uses, for example, a catalyst comprising a transition metal catalyst component (for example, a vanadium compound or a zirconium compound) and an organoaluminum compound catalyst component so as to have the above ethylene unit content in the copolymer. Further, it can be obtained by copolymerizing ethylene and α-olefin.

The propylene-based α-olefin copolymer preferably has a propylene content of more than 50 mol% and 95 mol% or less, more preferably 70 to 95 mol%, and monomer units other than propylene. Is preferably one or more selected from ethylene, 1-butene, 1-hexene and 1-octene. The density is preferably 0.858 to 0.885 g / cm ³ . A particularly preferred copolymer is a propylene-ethylene random copolymer (propylene elastomer). The propylene-ethylene random copolymer (propylene elastomer) may contain a monomer unit derived from α-olefin other than propylene and ethylene in an amount of 10 mol% or less. The propylene-based α-olefin copolymer used in the present invention can be produced, for example, using a metallocene catalyst as a catalyst, as described in JP-A No. 2000-191862.

  In the present invention, a commercially available product can be used as the α-olefin copolymer. Examples of the ethylene α-olefin copolymer include Tuffmer P series and Tuffmer A series (both manufactured by Mitsui Chemicals), Engage (manufactured by Dow Chemical Company) or the like is preferably used. In addition, as the propylene-based α-olefin copolymer, for example, Tafmer XM series (manufactured by Mitsui Chemicals) and the like are preferably used.

Polymethylpentene can also be used for the polyolefin in the present invention. Polymethylpentene is a homopolymer of 4-methyl-1-pentene (also known as 4-methylpentene-1), or α other than 4-methyl-1-pentene and ethylene or 4-methyl-1-pentene. -Copolymer with olefin, preferably 50 to 95 mol%, more preferably 70 to 95 mol% of 4-methyl-1-pentene, mainly comprising 4-methyl-1-pentene It is a crystalline polymer as a body unit. The polymer has a very low density of 0.83 to 0.86 g / cm ³ . Examples of the α-olefin other than 4-methyl-1-pentene include 3 to 20 carbon atoms such as propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene and 1-octadecene. 1-decene, 1-tetradecene, and 1-octadecene are preferable because they are α-olefins and have excellent copolymerizability with 4-methyl-1-pentene. In addition, TPX-S (made by Mitsui Chemicals) is mentioned as a commercial item of poly 4-methylpentene-1.

The polyolefin in the present invention is a concept including a polymer having a monomer unit of a diolefin such as isoprene and butadiene, as long as the diene rubber such as polyisoprene and polybutadiene can also be dissolved in an organic solvent. Can be used. As such polyisoprene, those having a cis-1,4 bond of 90 mol% or more, a density of 0.90 to 0.92 g / cm ³ , and a Mooney viscosity of 40 to 70 ML (1 + 4) 100 ° C. are preferable, Examples of such commercially available polyisoprene include IR-307 and IR-310 (manufactured by Kraton Polymer Co., Ltd.). The polybutadiene preferably has a cis-1,4 bond of 90 mol% or more, a density of 0.88 to 0.91 g / cm ³ , and a Mooney viscosity of 25 to 50 ML (1 + 4) 100 ° C. Preferable commercial products of polybutadiene include Nipol BR1220, Nipol BR1220L (all manufactured by Nippon Zeon), BR01 (manufactured by JSR), and the like.

  In addition, it is preferable that the polyolefin in this invention does not react with the alicyclic isocyanate mentioned later. However, it may be modified with a functional group such as a hydroxyl group, an amino group, a carboxy group, or an isocyanate group as long as the object of the present invention is not impaired. However, the number of functional groups in one molecule is preferably 1 or less.

  In the present invention, one or more polyolefins can be used for adjusting the peeling force. When an ethylene-based α-olefin copolymer and / or a propylene-based α-olefin copolymer is used in combination with an acrylic pressure-sensitive adhesive, the peeling force with time is unlikely to increase. For this reason, in the pressure-sensitive adhesive tape of the present invention described later, when the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive, the polyolefin uses an ethylene-based α-olefin copolymer and / or a propylene-based α-olefin copolymer. Is preferred. Further, when the release agent is used for an application where a relatively large release force is required, the polyolefin is preferably a propylene-based α-olefin copolymer and / or polymethylpentene.

  In the present invention, when only one kind of polyolefin is used, from the viewpoint of coating strength at the time of forming the release agent layer, the polyolefin preferably has an MFR (melt flow rate) at 230 ° C. of 100 g / 10 min or less, Those having an MFR of 70 g / 10 min or less are more preferred, those having an MFR of 50 g / 10 min or less are even more preferred, and those having an MFR of 10 g / 10 min or less are particularly preferred.

  Moreover, when using 2 or more types of polyolefin, it is preferable that at least 1 type of them has MFR in 230 degreeC at 100 g / 10min or less. In the release agent, the proportion of polyolefin having an MFR of 100 g / 10 min or less is preferably 10% by weight or more, and more preferably 50% by weight or more. If this condition is satisfied, another polyolefin having an MFR at 230 ° C. exceeding 100 g / 10 min may be used.

  The content of polyolefin in the release agent is preferably 80 to 99% by weight, more preferably 90 to 98% by weight. When the content is less than 80% by weight, the peelability tends to be poor and the peeling force tends to increase, and when it exceeds 99% by weight, it is difficult to obtain sufficient coating strength because there are too few components to be crosslinked. .

[Alicyclic isocyanate]
The alicyclic isocyanate in the present invention is used as a crosslinking component. The alicyclic isocyanate is preferable because sufficient adhesion to the substrate can be obtained rather than the aliphatic isocyanate. Further, from the viewpoint of the strength and heat resistance of the release agent layer, an alicyclic isocyanate having 3 or more isocyanate groups in one molecule is preferable. As the alicyclic isocyanate having 3 or more isocyanate groups in one molecule, a polyhydric alcohol adduct of alicyclic diisocyanate is most preferable. Examples of such polyhydric alcohol adducts include alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, dimer acid diisocyanate, norbornene diisocyanate, trans-cyclohexane diisocyanate, and hydrogenated tolylene diisocyanate. A terminal isocyanate-containing compound obtained by reacting a polyhydric alcohol with an excessive amount of Among these, polyhydric alcohol adducts of hydrogenated xylylene diisocyanate or isophorone diisocyanate are preferable. Examples of polyhydric alcohols here include aliphatic polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, and the like, and trimethylolpropane is preferred. Moreover, a multimer (for example, isocyanurate body) of alicyclic diisocyanate can be suitably used.

  These alicyclic isocyanates have low compatibility with polyolefins and are only compatible with polyolefins to the extent that they do not impair the releasability of polyolefins. Therefore, the remaining alicyclic isocyanate that is not compatible with the polyolefin is unevenly distributed between the polyolefin-based layer and the substrate, which greatly contributes to the adhesion between the release agent layer and the substrate.

  1 type (s) or 2 or more types can be used for an alicyclic isocyanate, The content is 0.5-20 weight part with respect to 100 weight part of polyolefin, Preferably it is 1.0-15 weight part, Furthermore, Preferably it is 1.5-10 weight part. When the content of the alicyclic isocyanate is less than 0.5 parts by weight based on 100 parts by weight of the polyolefin, it is difficult to obtain a sufficient effect for adhesion to the base material, and when the content exceeds 20 parts by weight, the base material This is not preferable because the adhesion effect does not increase further, and adverse effects such as a shortened pot life occur.

[Polyolefin polyol]
The polyolefin polyol in the present invention is to be reacted with an alicyclic isocyanate, but it is also important that the compatibility with the polyolefin is good. If a polyol having poor compatibility with polyolefin is used, not only the strength and heat resistance of the release agent layer cannot be improved, but also the applied release agent layer becomes whitish and cloudy, and the appearance of the coated surface also deteriorates.

  Therefore, a polyolefin polyol having a number average molecular weight (Mn) of 1500 to 5000, more preferably 1500 to 4000, and most preferably 1500 to 3000 is suitable. When the number average molecular weight of the polyolefin polyol exceeds 5000, the solubility with the alicyclic isocyanate is low, so that it can be almost dissolved in the layer mainly composed of the alicyclic isocyanate in the release agent layer (that is, the layer with less polyolefin). However, most of the polyolefin polyol is dissolved in the polyolefin-based layer, and it becomes difficult to react with the alicyclic isocyanate, and it becomes difficult to obtain sufficient substrate adhesion. Further, since the content of polyolefin polyol in the layer mainly composed of polyolefin is increased, the hydroxyl group in the layer mainly composed of polyolefin is excessive, which is likely to cause heavy peeling. On the other hand, if the number average molecular weight of the polyolefin polyol is less than 1500, the amount of the polyolefin polyol dissolved in the layer mainly composed of alicyclic isocyanate in the release agent layer (that is, the layer having a small amount of polyolefin) becomes too large. The polyolefin polyol content in the main layer becomes too small, and the effect of improving the strength and heat resistance of the entire release agent layer becomes difficult to obtain.

  The kind of polyolefin polyol is not particularly limited. For example, a polyethylene-type polyol, a polypropylene-type polyol, a polybutadiene polyol, a hydrogenated polybutadiene polyol, a polyisoprene polyol, a hydrogenated polyisoprene polyol, etc. are mentioned. Of these, hydrogenated polyisoprene polyol and polyisoprene polyol are preferable from the viewpoint of compatibility with polyolefin and influence on peeling force.

  The polyolefin polyol preferably has a hydroxyl value (mgKOH / g) of 20 or more from the viewpoint of the strength and curability of the release coating, and has a hydroxyl value (mgKOH / g) from the viewpoint of influence on the peeling force. 75 or less is preferable. More preferably, the hydroxyl value (mgKOH / g) is 25-60.

  In the present invention, as the polyolefin polyol, a commercially available product can be used. For example, Poly bdR-45HT (hydroxyl-terminated liquid polybutadiene: Mn = 2800, hydroxyl value = 46.6 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.) Poly ip (hydroxyl-terminated liquid polyisoprene: Mn = 2500, hydroxyl value = 46.6 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.), Epol (hydroxyl-terminated liquid hydrogenated polyisoprene: Mn = 2500, hydroxyl value = 50.5 mgKOH / G, manufactured by Idemitsu Kosan Co., Ltd.), GI-1000 (hydroxyl group-containing liquid hydrogenated polybutadiene: Mn = 1500, hydroxyl value = 60-75 mg KOH / g, manufactured by Nippon Soda Co., Ltd.), GI-2000 (hydroxyl group-containing liquid) Hydrogenated polybutadiene: Mn = 2100, hydroxyl value = 40-55 mg KOH / g, manufactured by Nippon Soda Co., Ltd.), GI-3000 (hydroxyl-containing liquid hydrogenated poly) Tajien: Mn = 3000, hydroxyl value = 25~35mgKOH / g, such as Nippon Soda Co., Ltd.) is preferably used. All of these polyols are liquid at 30 ° C.

  In this invention, the polyolefin polyol can use 1 type (s) or 2 or more types. The content of the polyolefin polyol in the release agent is set so that the value of A in the following formula is 30 to 250, preferably 40 to 200, more preferably 50 to 150. If the value of A is less than 30, the strength of the release agent layer tends to be insufficient, and if it exceeds 250, it tends to cause heavy peeling.

A = hydroxyl value of polyolefin polyol (mgKOH / g) × number of parts by weight of polyolefin polyol relative to 100 parts by weight of polyolefin

[Urethane catalyst]
In the present invention, a urethanization catalyst may be used for the reaction between the alicyclic isocyanate and the polyolefin polyol, and as the urethanization catalyst, a catalyst used in a normal urethanization reaction can be used. As urethanization catalysts, tin compounds such as dibutyltin dilaurate and dioctyltin dilaurate, metal carboxylates such as zinc, cobalt, copper and bismuth, amine compounds such as 1,4-diazabicyclo [2.2.2] octane, Examples thereof include chelate compounds of metals such as titanium and zirconium. In addition, bismuth organic acid salts (alicyclic organic acids such as abietic acid, neoabietic acid, d-pimalic acid, iso-d-pimalic acid, podocarpic acid, and bismuth resin acid containing two or more of these as a main component And bismuth salts of aromatic organic acids such as benzoic acid, cinnamic acid, and p-oxycinnamic acid. Of these, dibutyltin dilaurate, dioctyltin dilaurate, and bismuth resinate are preferred from the viewpoint of compatibility with the release agent composition and reactivity of the urethanization reaction.

  One or more urethanization catalysts can be used, and the content thereof is preferably 0.05 to 2.0 parts by weight, more preferably 0.1 to 1.5 parts by weight based on 100 parts by weight of polyolefin. Part by weight, more preferably 0.1 to 1.0 part by weight. If it is less than 0.05 parts by weight, the effect as a catalyst is often insufficient, and if it exceeds 2.0 parts by weight, it may cause heavy release, or the pot life in the form of a release agent solution may be shortened. Is likely to cause.

  The catalyst content referred to here is part by weight of the active ingredient, and is, for example, a solution type in which a compound of an active ingredient such as “Pucat B7” used in Examples described later is dissolved in a solvent. In this case, it means the weight part of the compound of the active ingredient only.

  In the release agent of the present invention, if necessary, an olefin resin other than the polyolefin, an antioxidant, an ultraviolet absorber, a light stabilizer such as a hindered amine light stabilizer and an antistatic agent, carbon black, calcium oxide, Fillers such as magnesium oxide, silica, zinc oxide and titanium oxide, pigments and the like may be appropriately blended.

2. Release material Moreover, this invention provides the release material which has the release agent layer which consists of the said release agent on the at least single side | surface of a base material.

〔Base material〕
Although it does not specifically limit as a base material in this invention, A plastic film is preferable at the point that the surface is smooth. Examples thereof include polyester films such as polyethylene terephthalate film and polybutylene terephthalate film, and polyolefin films such as polyethylene film and polypropylene film. When using paper such as kraft paper, glassine paper, fine paper, etc. as a base material, plastic or other plastics such as polyethylene are laminated to prevent the release agent component from excessively impregnating the base material. Are preferred.

  The substrate may be subjected to a treatment such as a corona treatment, a plasma treatment, or a flame treatment in advance as necessary. Moreover, there is no limitation in the thickness of a base material, Although it can set suitably according to a use purpose, in the case of a plastic film, it is about 12-250 micrometers normally, Preferably it is 16-200 micrometers, More preferably, it is 25-125 micrometers. is there.

  In addition, for the base material, an antioxidant, an ultraviolet absorber, a light stabilizer such as a hindered amine light stabilizer or an antistatic agent, carbon black, calcium oxide, magnesium oxide, silica, zinc oxide, titanium oxide, if necessary. A filler such as a filler, a pigment, and the like may be appropriately blended.

[Release layer]
The release agent layer in the present invention can be obtained, for example, by dissolving a composition constituting the release agent in a diluting solvent, applying the solution to a substrate, and drying the solution. The concentration of the solution is not particularly limited, but is usually adjusted within a range of 0.1 to 5% by weight.

  The diluting solvent is not particularly limited as long as the release agent composition can be uniformly dissolved. However, since the release agent in the present invention contains polyolefin as a main component, it is possible to use a hydrocarbon solvent mainly. It is preferable from the viewpoint of dissolving. Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents such as normal hexane and normal heptane, alicyclic hydrocarbon solvents such as cyclohexane, and aromatic hydrocarbon solvents such as toluene and xylene. Further, if necessary, ketones such as methyl ethyl ketone, cyclohexanone and acetylacetone, esters such as ethyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol may be used in combination.

  In addition, as a method of applying the release agent to the substrate, a known and commonly used method such as a kiss roll coater, a bead coater, a rod coater, a Meyer bar coater, a die coater, or a gravure coater can be used. There is no particular limitation on the drying method, but the most common method is hot air drying. Depending on the heat resistance of the substrate, the release agent layer can be obtained by drying at a temperature of about 80 to 150 ° C.

  Further, the thickness of the release agent layer is preferably 30 to 500 nm, more preferably 45 to 400 nm, and most preferably 60 to 300 nm. When the thickness of the release agent layer is less than 30 nm, heavy peeling may occur, and when it exceeds 500 nm, blocking may occur when the film is wound into a roll, or the peeling force may increase.

3. Moreover, this invention provides the adhesive tape which has the said mold release material in the at least single side | surface of an adhesive layer, and this adhesive layer and the release agent layer of this mold release material are contacting. .

  The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is not particularly limited, and examples thereof include rubber-based, acrylic-based, and polyester-based pressure-sensitive adhesives. Among these, acrylic-based pressure-sensitive adhesives and polyester-based pressure-sensitive adhesives are stable peels. It is preferable because of its property.

  Acrylic adhesives are mainly based on acrylic polymers obtained by conventional polymerization methods such as solution polymerization, emulsion polymerization, and UV polymerization, and as necessary, crosslinking agents, tackifiers, softeners, and anti-aging agents. It can be prepared by adding various additives such as an agent and a filler.

  Examples of the acrylic polymer include alkyl (meth) acrylates such as butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate as main components, and, as a modifying monomer that can be copolymerized therewith, 2- A monomer mixture in which other monomers such as hydroxyl group-containing monomers such as hydroxyethyl (meth) acrylate, carboxy group-containing monomers such as (meth) acrylic acid, styrene monomers such as styrene, vinyl esters such as vinyl acetate, etc. A copolymer is used.

  In addition, the polyester-based pressure-sensitive adhesive includes polyester-based heavy diols containing an aliphatic carbonate diol (for example, a carbonate diol obtained by a reaction of a diol component such as butanediol and a carbonate compound such as ethylene carbonate) as an essential polyol component. A pressure-sensitive adhesive mainly composed of coalesce is mentioned.

  The pressure-sensitive adhesive layer can be formed, for example, by applying a pressure-sensitive adhesive solution on the release agent layer and drying it. Moreover, the thickness of an adhesive layer can be suitably selected in consideration of adhesiveness etc., and is 3-100 micrometers normally, Preferably it is 5-90 micrometers, More preferably, it is 10-80 micrometers.

4). The pressure-sensitive adhesive tape having a release agent layer made of a release agent The present invention also has a pressure-sensitive adhesive layer on one side of a base material and a release agent layer made of the release agent of the present invention on the other side (hereinafter “back treatment layer”). The pressure-sensitive adhesive tape is provided.

  In the pressure-sensitive adhesive tape, both the pressure-sensitive adhesive layer and the back surface treatment layer may be formed directly on the base material, or another layer may be formed between these layers and the base material. Good. However, both the pressure-sensitive adhesive layer and the back treatment layer must be present on the outermost surface. In addition, it is preferable that both the pressure-sensitive adhesive layer and the back treatment layer are directly formed on the substrate.

  The pressure-sensitive adhesive tape may be in a form wound in a roll shape or a form in which sheets are laminated, and in any form, the pressure-sensitive adhesive layer can be protected by the back treatment layer.

  The pressure-sensitive adhesive used in the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include rubber-based, acrylic-based, and polyester-based pressure-sensitive adhesives. Among these, acrylic-based pressure-sensitive adhesives and polyester-based pressure-sensitive adhesives provide stable peelability. preferable.

  Further, the back treatment layer can be formed by the same method as the release agent layer in the above-mentioned release material, and the thickness of the back treatment layer is preferably 30 to 500 nm, more preferably 45 to 45 nm, from the viewpoint of peeling force. 400 nm, most preferably 60-300 nm.

The physical properties, characteristics, etc. in this specification are measured values by the following methods.
(1) Density This is a value measured according to ASTM D1505.
(2) Melt flow rate (230 ° C)
It is a value measured according to ASTM D1238.
(3) Number average molecular weight It is the value measured based on ASTM D2503.
(4) Hydroxyl value A value measured in accordance with JIS K1557.

  The present invention will be described more specifically with reference to examples. The present invention is not limited by these.

  The materials used in the examples and comparative examples are collectively described below. Note that “%” described below represents “% by weight” unless otherwise specified.

Polyolefin Tuffmer A-1070S (ethylene-1-butene copolymer (ethylene 85 mol%, 1-butene 15 mol%), manufactured by Mitsui Chemicals, MFR (230 ° C.) 2.2 g / 10 min, density 0.87 g / cm ³ ),
TAFMER A-3570S (ethylene-1-butene copolymer (ethylene 85 mol%, 1-butene 15 mol%), manufactured by Mitsui Chemicals, MFR (230 ° C.) 65 g / 10 min, density 0.87 g / cm ³ )
TAFMER P-0280 (ethylene-propylene copolymer (ethylene 87 mol%, propylene 13 mol%), manufactured by Mitsui Chemicals, MFR (230 ° C.) 5.4 g / 10 min, density 0.87 g / cm ³ )
TAFMER XM-7070 (propylene-1-butene copolymer (propylene 74 mol%, 1-butene 26 mol%), manufactured by Mitsui Chemicals, MFR (230 ° C.) 7 g / 10 min)

Polyolefin polyol epoxide (hydroxyl-terminated liquid hydrogenated polyisoprene, Mn = 2500, hydroxyl value 50.5 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.)
Poly ip (hydroxyl-terminated liquid polyisoprene, Mn = 2500, hydroxyl value 46.6 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.)
Unistor P-901 (22% toluene solution of hydroxyl group-containing polyolefin, toluene removal product is Mn> 5000 of solid / solid content, hydroxyl value 50 mgKOH / g, manufactured by Mitsui Chemicals)

Isocyanate coronate HL (75% ethyl acetate solution of trimethylolpropane adduct of hexamethylene diisocyanate, 3 isocyanate groups in one molecule, manufactured by Nippon Polyurethane)
Coronate HX (hexamethylene diisocyanate trimer, number of isocyanate groups in one molecule: 3, manufactured by Nippon Polyurethane)
Takenate D120N (75% ethyl acetate solution of trimethylolpropane adduct of hydrogenated xylylene diisocyanate, 3 isocyanate groups in one molecule, manufactured by Mitsui Chemicals)
Takenate D140N (75% ethyl acetate solution of trimethylolpropane adduct of isophorone diisocyanate, 3 isocyanate groups per molecule, manufactured by Mitsui Chemicals)
Death Module W (hydrogenated diphenylmethane diisocyanate, number of isocyanate groups in one molecule: 2, manufactured by Sumika Bayer Urethane Co., Ltd.)

Urethane catalyst dibutyltin dilaurate (Wako Pure Chemical Industries, Ltd.)
ENVILIZER OL-1 (Dioctyltin dilaurate, manufactured by Tokyo Fine Chemical Co., Ltd.)
Pucat B7 (58% mineral spirit solution of bismuth resinate, manufactured by Nippon Chemical Industry Co., Ltd.)

Further, the release materials prepared in Examples and Comparative Examples were evaluated according to the following methods.
(1) Adhesion of release agent layer to substrate The release agent layer surface of the release agent was judged in a state when it was rubbed 3 times with a finger.
○: No change. Alternatively, the surface becomes whitish and cloudy, but the coating film does not fall off.
X: A residue that appears when the coating film falls off and is rubbed with an eraser is generated, and the substrate is exposed.

(2) Acrylic pressure-sensitive adhesive tape No. 31B (manufactured by Nitto Denko Corporation) was bonded to the surface of the release agent layer of the release material using a hand roller and stored at 23 ° C. for 24 hours, and then the tape was 0.3 m / min in the 180 ° direction with a tensile tester. It pulled at speed and measured peeling force in 23 degreeC atmosphere.

(3) Acrylic pressure-sensitive adhesive tape having a peeling force of 50 mm width after heating 31B (manufactured by Nitto Denko Corporation) was bonded to the surface of the release agent layer of the release material using a hand roller, heated at 70 ° C. for 24 hours, then cooled at 23 ° C. for 1 to 2 hours, and the tape was rotated with a tensile tester. The film was pulled at a speed of 0.3 m / min in the ° direction, and the peeling force was measured in an atmosphere at 23 ° C.

(4) Peeling force maintainability compared with a single polyolefin The release force after heating of the release materials of Examples 1 to 7 and Comparative Examples 1 to 4 was determined as a release material (comparative example) formed of the same single polyolefin as the release material. 5 to 7) and the peel strength after heating (specifically, Examples 1 to 3 and Examples 5 to 6 are Comparative Example 5 and Example 4 is Comparative Example 6 and Example 7). And Comparative Example 7 and Comparative Examples 1 to 4 are respectively compared with Comparative Example 5), the case where the peel strength after heating is 1.5 times or less of the peel strength after heating of the release material formed of the polyolefin alone. In the case where the peel force maintainability exceeds ◯ and 1.5 times, the peel force maintainability was evaluated as x.

Example 1
Tuffmer A-1070S / Epol / Takenate D120N / Dibutyltin dilaurate = 100/2/3 / 0.2 (weight ratio of solid content) was dissolved in toluene to prepare a release agent solution having a concentration of 1.5%. This release agent solution was applied to a polyethylene terephthalate film having a thickness of 38 μm with a Mayer bar # 6, and then heated with a hot air dryer at 130 ° C. for 1 minute to obtain a release material. The thickness of the release agent layer of the obtained release material was about 150 nm.

Example 2
A mold release material was prepared in the same manner as in Example 1 except that the base material of Example 1 was changed to a biaxially stretched polypropylene film (corona-treated surface wetting index 39 mN / m) having a single-sided corona treatment with a thickness of 40 μm. The release agent was applied to the corona-treated surface.

Example 3
A release material was prepared in the same manner as in Example 1 except that the base material of Example 1 was changed to a polyethylene film (corona-treated surface wetting index of 50 mN / m) having a single-sided corona treatment with a thickness of 60 μm. The release agent was applied to the corona-treated surface.

Example 4
Example 1 except that the composition of the release agent was Toughmer P-0280 / Toughmer A-35070S / Epol / Takenate D120N / Dibutyltin dilaurate = 60/40/1/3 / 0.2 (weight ratio of solid content) A mold release material was prepared in the same manner as described above.

Example 5
A release agent in the same manner as in Example 1 except that the composition of the release agent was Toughmer A-1070S / Epol / Takenate D140N / Dibutyltin dilaurate = 100/2/3 / 0.2 (weight ratio of solid content). Was made.

Example 6
The release agent was prepared in the same manner as in Example 1 except that the composition of the release agent was Toughmer A-1070S / Epol / Takenate D120N / Pucat B7 = 100/2/10 / 0.6 (weight ratio of solid content). Produced.

Example 7
The same method as in Example 1 except that the composition of the release agent was Toughmer XM-7070 / Poly ip / Takenate D120N / Embabilizer OL-1 = 100/2 / 0.5 / 1 (weight ratio of solid content). A mold release material was prepared.

Comparative Example 1
A release agent in the same manner as in Example 1 except that the composition of the release agent was Toughmer A-1070S / Epol / Coronate HL / Dibutyltin dilaurate = 100/2/10 / 0.2 (weight ratio of solid content). Was made.

Comparative Example 2
Except that the composition of the release agent was Toughmer A-1070S / Epol / Coronate HX / Dibutyltin dilaurate = 100/2 / 1.6 / 0.2 (weight ratio of solid content), the same method as in Example 1 was used. A release material was produced.

Comparative Example 3
The release agent was separated in the same manner as in Example 1 except that Toughmer A-1070S / Epol / Desmodur W / Dibutyltin dilaurate = 100/2/5 / 0.2 (weight ratio of solid content). A mold material was produced.

Comparative Example 4
Except that the composition of the release agent was Toughmer A-1070S / Unistor P-9011 / Takenate D120N / Dibutyltin dilaurate = 100/2/3 / 0.2 (weight of solid content), the same method as in Example 1 A release material was produced.

Comparative Example 5
A mold release material was produced in the same manner as in Example 1 except that the composition of the release agent was changed to Toughmer A-1070S = 100.

Comparative Example 6
A mold release material was prepared in the same manner as in Example 1 except that the composition of the release agent was Toughmer P-0280 / Toughmer A-3570S = 60/40 (weight ratio of solid content).

Comparative Example 7
It was produced in the same manner as in Example 1 except that the composition of the release agent was Toughmer XM-7070 = 100.

  FIG. 1 is a transmission electron microscope (TEM) photograph of a cross section of a release agent layer in a release material prepared in Example 1, and the release material was subjected to a dyeing process (immersion in a 2 wt% ruthenic acid aqueous solution for about 2 hours). Thereafter, the sample obtained by embedding in an epoxy resin and cutting to a thickness of about 100 nm by an ultrathin section method was taken with a transmission electron microscope (HITACHI H-7650, acceleration voltage 100 kV).

FIG. 2 is a diagram showing the results of depth direction X-ray photoelectron spectroscopy (XPS) analysis of the release agent layer in the release material prepared in Example 1. FIG. In the figure, arrow a indicates the carbon derived from the release agent and the substrate, arrow b indicates the oxygen derived from the release agent and the substrate (polyester film), and arrow c indicates the nitrogen derived from the isocyanate in the release agent. Show.
The analyzer and measurement conditions are as follows.
ESCA device: Quantera SXM manufactured by ULVAC-PHI
X-ray source: Monochrome Al Kα
Xray Setting: 100 μmφ [25 W (15 kV)]
Photoelectron extraction angle: 45 degrees with respect to the sample surface Neutralization condition: combined use of neutralization gun and Ar ion gun (neutralization mode) C ₆₀ ion gun pressurization voltage: 10 kV
C ₆₀ ion gun raster size: 0.5mm × 2mm
C ₆₀ ion gun etch rate: about 16 nm / min

  1 and 2, since the release agent of the present invention has low compatibility between polyolefin and alicyclic isocyanate, it is divided into a layer mainly composed of polyolefin and a layer mainly composed of alicyclic isocyanate. It can be seen that the layer mainly composed of is unevenly distributed between the layer mainly composed of polyolefin and the substrate. For this reason, it is thought that favorable base material adhesiveness can be obtained, without inhibiting the original peelability of polyolefin.

  Table 1 shows the evaluation results of the release materials prepared in Examples and Comparative Examples.

  The release materials of Examples 1 to 7 were excellent in the adhesion of the release agent layer to the base material. Moreover, when the release material of an Example is compared with the release material (any one of Comparative Examples 5-7) formed only with the same polyolefin as this release material, Examples 1-3 and Examples 5-6 are comparison. Example 5 and Example 4 were compared with Comparative Example 6 and Example 7 were respectively compared with Comparative Example 7), and any of the release materials of Examples 1 to 7 was a release material formed of a single polyolefin, normal release force, and The peel strength after heating was almost the same, and the original peelability of the polyolefin was maintained.

On the other hand, since the release materials of Comparative Examples 1 and 2 used aliphatic isocyanate, the adhesion to the substrate was insufficient. Further, the release material of Comparative Example 2 had a large peel force after heating, and could not maintain the original peelability of polyolefin.
Moreover, since the release material of Comparative Example 3 used an alicyclic isocyanate having less than 3 isocyanate groups in one molecule, the adhesion to the substrate was insufficient. Moreover, the peeling force after heating became large, and the original peelability of polyolefin could not be maintained.
Moreover, since the release material of Comparative Example 4 used an alicyclic isocyanate having 3 or more isocyanate groups in one molecule, adhesion to the substrate was obtained, but the number average molecular weight (Mn) was 5000. Since a polyolefin polyol exceeding the amount was used, a large amount of polyol was contained in a layer mainly composed of polyolefin, and the peeling force after heating was increased by the hydroxyl group of the polyol, and the original peelability of polyolefin could not be maintained.
Thus, from the comparative example, it was not possible to obtain a mold release material having both substrate adhesion and polyolefin original peel strength maintenance.

DESCRIPTION OF SYMBOLS 1 Layer mainly made of polyolefin 2 Layer mainly made of isocyanate 3 Release agent layer 4 Base material

Claims (6)

  A release agent containing at least a polyolefin polyol having a polyolefin, an alicyclic isocyanate having 3 or more isocyanate groups in one molecule, and a number average molecular weight of 1500 to 5000.   The release agent according to claim 1, wherein the alicyclic isocyanate is a polyhydric alcohol adduct of alicyclic diisocyanate.   The release agent according to any one of claims 1 and 2, wherein a content of the alicyclic isocyanate is 0.5 to 20 parts by weight with respect to 100 parts by weight of the polyolefin.   The mold release material which has a release agent layer which consists of a release agent of any one of Claims 1-3 in the at least single side | surface of a base material.   An adhesive tape comprising the release material according to claim 4 on at least one surface of the adhesive layer, wherein the adhesive layer and the release agent layer of the release material are in contact with each other.   The adhesive tape which has an adhesive layer on the one side of a base material, and has the releasing agent layer which consists of a releasing agent of any one of Claims 1-3 in the other surface.