JP2013072064A - Marking film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marking film which can suppress an adhesion of dirt or an occurrence of water stain remains and suppress a lift of a shape of the marking film on a new foundation film surface when affixing a new foundation film in piles, and which has excellent adhesive force.SOLUTION: The marking film 1a has a base material 11 and an adhesive layer 12. Total thickness of the film after pasting is 25 μm or less and a ratio [adhesive layer/base material] of the thickness of the adhesive layer to the thickness of the base material is 0.02-0.85.

Description

  The present invention relates to a marking film used for a signboard or the like.

  In recent years, pressure-sensitive adhesive sheets (including pressure-sensitive adhesive tapes, hereinafter the same) have been widely used in many fields. For example, for packaging / bundling, office / home use, bonding, paint masking, surface protection, sealing, anticorrosion / waterproofing, electrical insulation, electronic equipment, medical / hygiene materials, display / signs, Used for decoration, labels, etc.

On the other hand, among the recent applications, in the field of marking films such as adhesive sheets for display and signs and adhesive sheets for decoration, in order to improve the productivity of painted products and reduce manufacturing costs, As such, the demand for this marking film is increasing.
For indications / signs, for example, danger indication tapes, line tapes, marking tapes, etc. are used. For decoration, signs, show windows, interior / exterior of buildings, decoration of cars and motorcycles with marking sheets / stickers, etc. A marking film is used.
There are various adherends to which such a marking film is applied, and examples thereof include metal plates, painted metal plates, glass, ceramics, stone materials, wooden materials, plastics, and papers.

  By the way, as for these marking films, the affixed product is often used outdoors, and the base material and the pressure-sensitive adhesive constituting the marking film are required to have excellent weather resistance. Therefore, an acrylic pressure-sensitive adhesive having good weather resistance is usually used as the pressure-sensitive adhesive, and a film base material made of vinyl chloride resin, polyacrylate, thermoplastic polyurethane or the like is used as the base material. As such a marking film, the thing of patent document 1 and 2 is known, for example.

  When such a marking film is used for decoration such as a signboard, a colored marking film (hereinafter also referred to as “underlying film”) as a base is usually applied to the entire surface of the adherend, and the company name A colored marking film cut out so as to be in the shape of a design such as a letter or a design is applied to the decoration.

JP 2000-265123 A JP 2001-271045 A

However, in the marking films described in Patent Documents 1 and 2, etc., when the film is bonded to the base film or the adherend, the step between the marking film and the base film is large, and dirt easily adheres to the step. Traces of scale are also likely to occur. In particular, when a marking film on which letters or designs are formed is affixed, the adhesion of dirt and the occurrence of traces of water stains appear more prominently.
In addition, when a new decoration is to be applied to a signboard or the like, a new base film may be overlaid on the old marking film without peeling off the decorative marking film that has already been attached. In this case, if the old marking film is normal, the shape of the old marking film located below will rise to the surface of the base film even if a new base film is overlaid. Therefore, the old marking film located under must be peeled off, and there are problems in terms of cost and workability.

  The present invention can suppress the adhesion of dirt and traces of scales, and further suppresses the lifting of the shape of the marking film on the surface of the base film when it is overlaid, and has excellent adhesive strength. It aims at providing the marking film which has these.

The present inventors have found that the above problem can be solved by adjusting the total thickness of the marking film after application and the ratio of the thickness of the pressure-sensitive adhesive layer to the substrate constituting the marking film.
That is, the present invention provides the following [1] to [11].
[1] A marking film having a base material and a pressure-sensitive adhesive layer, wherein the total thickness of the film after application is 25 μm or less, and the ratio of the thickness of the pressure-sensitive adhesive layer to the thickness of the base material [pressure-sensitive adhesive Marking film whose [layer / base material] is 0.02-0.85.
[2] The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer contains (A) an acrylic copolymer having a crosslinkable functional group, (B) a urethane resin, and (C) a crosslinking agent. The marking film as described in [1] above.
[3] (B) The urethane resin is obtained by reacting (b3) a chain extender with a terminal isocyanate urethane prepolymer obtained by reacting (b1) a diol with (b2) a polyvalent isocyanate compound. (B3) the chain extender is (b4) a compound having two hydroxyl groups and / or amino groups, and (b5) a compound having three or more hydroxyl groups and / or amino groups, The marking film according to the above [2], wherein the mass ratio [b5) / (b5)] to the component b5) is 70/30 to 100/0.
[4] The marking film according to [3], wherein the component (b4) has a hydroxyl group and an amino group.
[5] The marking film according to [3] or [4], wherein (b1) the diol is a glycol having a weight average molecular weight of 1,000 to 3,000.
[6] The marking according to any one of [2] to [5], wherein the crosslinkable functional group of the component (A) is derived from an ethylenically unsaturated carboxylic acid or (meth) acrylic acid hydroxyalkyl ester. the film.
[7] The above [2] to [6], wherein the mass ratio [(A) / (B)] of (A) acrylic copolymer and (B) urethane resin is 1/99 to 40/60. The marking film according to any one of the above.
[8] The marking film according to any one of [2] to [7], wherein the weight average molecular weight (Mw) of (A) the acrylic copolymer is 300,000 to 1,500,000.
[9] The marking film according to any one of [1] to [8], wherein the pressure-sensitive adhesive layer has a thickness of 0.5 to 10 μm and the base material has a thickness of 1 to 20 μm.
[10] The marking film according to any one of [1] to [9], wherein the marking film is used outdoors and is formed in the shape of a character or a design.
[11] The marking film according to any one of the above [1] to [10], wherein the marking film is further laminated with another marking film.

  Since the marking film of the present invention has a small step with the base film, it can suppress the adhesion of dirt and traces of water stains. When a new base film is overlaid, the marking film on the film surface Suppresses the lifting of the shape and has excellent adhesive strength.

It is sectional drawing of this film which shows one aspect | mode of the structure of the marking film of this invention. It is sectional drawing of this film which shows the usage aspect of the marking film of this invention. It is sectional drawing of this film which shows the usage aspect of the conventional marking film.

  The marking film of this invention will not be specifically limited if it has a base material and an adhesive layer. FIG. 1 is a diagram showing one embodiment of the configuration of the marking film of the present invention. The configuration of the marking film of the present invention is not limited to the marking film 1a having the pressure-sensitive adhesive layer 12 on the substrate 11, as shown in FIG. For example, as shown in FIG. 1B, a marking film 1b having a release material 13 on the pressure-sensitive adhesive layer 12 can be used. Moreover, it can also be set as the marking film 1c which has the coating layer (antifouling layer) 14 on the opposite side to the surface in which the adhesive layer 12 of the base material 11 was formed like FIG.1 (c). .

In the present invention, the “total thickness of the film after pasting” refers to the marking film excluding the thickness of the release material and the like removed at the time of pasting from the total thickness of the marking film including the release material 14 and the like. It means thickness. For example, the marking films 1a and 1b shown in FIG. 1 indicate the total thickness of the substrate 11 and the pressure-sensitive adhesive layer 12 (thickness indicated by Za and Zb in FIG. 1). In the marking film 1c, the substrate 11 , The total thickness of the pressure-sensitive adhesive layer 12 and the coating layer (antifouling layer) 14 (thickness indicated by Zc in FIG. 1).
In addition, the thickness of each layer of the marking film of this invention means the value measured by the method as described in an Example.

In this invention, although the total thickness of the film after sticking is adjusted to 25 micrometers or less, Preferably it is 3-23 micrometers, More preferably, it is 5-20 micrometers, More preferably, it is 7-18 micrometers.
When the total thickness exceeds 25 μm, it is difficult to suppress the adhesion of dirt and the occurrence of traces of scale because of the large difference in level with the base film and the like. In addition, when a new base film is overlaid, it is not preferable because the marking film according to the present invention is conspicuously raised on the surface of the film.
In addition, when the total thickness is 3 μm or more, both the base material and the pressure-sensitive adhesive layer have sufficient thickness, so that a marking film having excellent weather resistance and sufficient adhesive force can be obtained.

  In the marking film of the present invention, the ratio of the thickness of the pressure-sensitive adhesive layer to the thickness of the base material [pressure-sensitive adhesive layer / base material] is 0.02 to 0.85, preferably 0.15 to 0.85. More preferably, it is 0.20-0.83, More preferably, it is 0.25-0.83, More preferably, it is 0.30-0.80. If the ratio is less than 0.02, the thickness of the pressure-sensitive adhesive layer is insufficient. On the other hand, when the ratio exceeds 0.85, the thickness of the base material is insufficient, so that the weather resistance of the marking film is inferior. In addition, it becomes difficult to control wrinkles and slack during the manufacturing process and the pasting operation of the marking film.

The thickness of the base material and the pressure-sensitive adhesive layer of the marking film of the present invention is not particularly limited as long as the thickness is adjusted so as to satisfy the above requirements, but the following ranges are preferable.
That is, the thickness of the pressure-sensitive adhesive layer is preferably 0.5 to 10 μm, more preferably 1 to 8 μm, from the viewpoint of imparting sufficient adhesive force and reducing the difference in level with the base film and the like after pasting. Preferably it is 2-6 micrometers.
In addition, the thickness of the base material is preferably 1 to 20 μm, more preferably from the viewpoint of imparting sufficient weather resistance, making it easy to control wrinkles and slack, and reducing the level difference with the underlying film after pasting. Is from 3 to 16 μm, more preferably from 5 to 12 μm from the point.

[Adhesive layer]
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer used in the present invention is not particularly limited as long as it has sufficient adhesive force even if the pressure-sensitive adhesive layer is thinned, but (A) an acrylic type having a crosslinkable functional group What contains a copolymer, (B) urethane resin, and (C) a crosslinking agent is preferable. Moreover, you may contain another additive, an organic solvent, etc. as needed. Hereinafter, each component contained in the said adhesive is demonstrated.

<(A) Acrylic copolymer>
Various pressure-sensitive adhesives can be used in the present invention. From the viewpoint of obtaining a sufficiently high pressure-sensitive adhesive layer from a thin pressure-sensitive adhesive layer, (A) an acrylic copolymer having a crosslinkable functional group (hereinafter, simply referred to as an adhesive copolymer). It is preferable to contain "(A) acrylic copolymer" or "(A) component"). In the present invention, the “acrylic copolymer having a crosslinkable functional group” is a monomer mixture containing (meth) acrylic acid ester as a main component and (C) a crosslinkable functional group-containing monomer that reacts with a crosslinker. Is an acrylic copolymer obtained through a polymerization reaction. Therefore, the (A) acrylic copolymer to be used contains at least a structural unit derived from a (meth) acrylic acid ester and a structural unit derived from a crosslinkable functional group-containing monomer.
In the following description, for example, “(meth) acrylic acid” means both acrylic acid and methacrylic acid, and the same applies to other similar terms.

The content of the structural unit derived from the (meth) acrylic acid ester is preferably 70 to 99.9% by mass, more preferably from all structural units of the component (A), from the viewpoint of obtaining sufficient adhesive strength even if it is thinned. Is 80 to 99.5% by mass, more preferably 85 to 99% by mass, and more preferably 88 to 95% by mass.
The content of the structural unit derived from the crosslinkable functional group-containing monomer is preferably from 0.1 to 20% by mass, more preferably from 0.1 to 20% by mass, from the viewpoint of obtaining sufficient adhesive strength even if the film is thinned. Is 0.5 to 15% by mass, more preferably 1 to 12% by mass.
In addition, there is no restriction | limiting in particular about the copolymerization form of (A) acrylic copolymer, Any of a random, a block, and a graft copolymer may be sufficient.

(A) The crosslinkable functional group possessed by the acrylic copolymer is a functional group capable of reacting with the crosslinking agent of component (C), and examples thereof include a carboxy group, a hydroxyl group, and an amino group. Among these, a carboxy group and a hydroxyl group are preferable from the viewpoint of reactivity with the crosslinking agent of the component (C), and a carboxy group is more preferable from the viewpoint of obtaining higher adhesive strength.
Moreover, (A) The crosslinkable functional group which an acrylic copolymer has has an ethylenically unsaturated carboxylic acid or ( Those derived from hydroxyalkyl esters of meth) acrylic acid are preferred, and those derived from ethylenically unsaturated carboxylic acids are more preferred.

  Examples of the (meth) acrylic acid ester that is a main component monomer of the acrylic copolymer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. , Pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic acid Examples include dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, butyl (meth) acrylate is preferable from the viewpoint of obtaining sufficient adhesive strength even if the pressure-sensitive adhesive layer is thinned.

These (meth) acrylic acid esters may be used alone or in combination of two or more. In addition, when using 2 or more types together, from the viewpoint of obtaining sufficient adhesive strength even if the pressure-sensitive adhesive layer is thinned, the content of butyl (meth) acrylate is preferably in the (meth) acrylate ester used, preferably 50 to It is 100 mass%, More preferably, it is 70-100 mass%, More preferably, it is 80-100 mass%.
The content of the (meth) acrylic acid ester is preferably 70 to 99.000 in the monomer mixture which is a raw material of the acrylic copolymer, from the viewpoint of obtaining sufficient adhesive strength even when the pressure-sensitive adhesive layer is thinned. 9 mass%, More preferably, it is 80-99.5 mass%, More preferably, it is 85-99 mass%, More preferably, it is 88-95 mass%.

Examples of the monomer having a crosslinkable functional group include (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid and other ethylenically unsaturated carboxylic acids, (meth) acrylic acid 2-hydroxyethyl, (Meth) acrylic acid 4-hydroxybutyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 2-hydroxybutyl, (meth) acrylic acid 3-hydroxybutyl, etc. (Meth) acrylic acid hydroxyalkyl ester, (meth) acrylic acid monomethylaminoethyl, (meth) acrylic acid monoethylaminoethyl, (meth) acrylic acid monomethylaminopropyl, (meth) acrylic acid monoethylaminopropyl ( And (meth) acrylic acid monoalkylaminoalkyl In addition, you may use these monomers individually or in combination of 2 or more types.
Among these, from the viewpoint of reactivity with the crosslinking agent, and from the viewpoint of obtaining sufficiently high adhesive force even if the pressure-sensitive adhesive layer is thinned, ethylenically unsaturated carboxylic acid, (meth) acrylic acid hydroxyalkyl ester are preferable, Ethylenically unsaturated carboxylic acids are more preferred.

  The content of the monomer having a crosslinkable functional group is preferably 0 in the monomer mixture which is a raw material of the acrylic copolymer, from the viewpoint of obtaining sufficient adhesive strength even when the pressure-sensitive adhesive layer is thinned. 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and still more preferably 1 to 12% by mass.

The (A) acrylic copolymer may contain a structural unit derived from a monomer other than the above as a structural unit.
Examples of other monomers include vinyl esters such as vinyl acetate and vinyl propionate, olefins such as ethylene, propylene, and isobutylene, halogenated olefins such as vinyl chloride and vinylidene chloride, styrene, methylstyrene, and vinyl. Examples thereof include aromatic vinyl monomers such as toluene, diene monomers such as butadiene, isoprene and chloroprene, and nitrile monomers such as (meth) acrylonitrile. These monomers may be used alone or in combination of two or more.

The method for obtaining the (A) acrylic copolymer from these monomer mixtures is not particularly limited, and can be carried out by a known polymerization method in the presence or absence of a solvent. Examples of the solvent to be used include ethyl acetate and toluene.
Further, a polymerization initiator may be used in the polymerization reaction. Examples of the polymerization initiator include azobisisobutyronitrile and benzoyl peroxide. The blending amount of these polymerization initiators is preferably 0.01 to 1 part by mass, more preferably 0.1 to 0.5 part by mass with respect to 100 parts by mass of the monomer mixture.
Moreover, it does not specifically limit as polymerization conditions, However, It is preferable to carry out on the conditions for polymerization temperature 50-90 degreeC and reaction time 2-30 hours.

The weight average molecular weight of the (A) acrylic copolymer thus obtained is preferably 300,000 to 1,500,000, more preferably 400,000 to 1,000,000, and more preferably, from the viewpoint of improving the adhesive performance and the like. 500,000 to 800,000. If it is 300,000 or more, the cohesive force of the pressure-sensitive adhesive layer is improved, and sufficient adhesive force can be obtained. Moreover, if it is 1.5 million or less, the elasticity modulus of an adhesive layer will not become high too much and the fall of adhesive force can be suppressed.
In addition, in this invention, a weight average molecular weight (Mw) means the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method, and is specifically the value measured by the method as described in an Example. (The same shall apply hereinafter).

<(B) Urethane resin>
The pressure-sensitive adhesive used in the present invention preferably contains (B) a urethane resin (hereinafter also simply referred to as “component (B)”). (B) By containing a urethane resin, a sufficiently high adhesive force can be obtained even if the pressure-sensitive adhesive layer is thinned.
In the present invention, the mass ratio [(A) / (B)] of (A) acrylic copolymer and (B) urethane resin is used to obtain an adhesive having an appropriate elastic modulus, and the adhesive layer is made into a thin film. From the viewpoint of obtaining a sufficient adhesive force even if it is adjusted, it is preferably 1/99 to 40/60, more preferably 5/95 to 30/70, and still more preferably 10/90 to 25/75. If the said mass ratio which shows the ratio of (A) component with respect to (B) component is 1/99 or more, the fall of the adhesive force by an elasticity modulus becoming too low can be avoided, What is 40/60 or less? In this case, it is possible to avoid a decrease in adhesive force due to an excessively high elastic modulus.

  (B) Urethane resin used in the present invention is obtained by reacting (b3) a chain extender with a terminal isocyanate urethane prepolymer obtained by reacting (b1) diol with (b2) a polyvalent isocyanate compound. A urethane resin is preferred.

(B1) Examples of the diol include alkanes such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptanediol. Examples include diols, alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol, and polyoxyalkylene glycols such as polytetramethylene glycol. In addition, you may use these (b1) diols individually or in combination of 2 or more types.
Among these (b1) diols, a medium molecular weight glycol having a weight average molecular weight of about 1000 to 3000 is preferable from the viewpoint of suppressing gelation in the reaction of the obtained terminal isocyanate urethane prepolymer and (b3) chain extender.

(B2) Examples of the polyvalent isocyanate compound include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate.
Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2 , 6-Tolylene diisocyanate (2,6-TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4 ' -Diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate and the like.
Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, and dodeca. Examples include methylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate.
Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, Methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanatemethyl) cyclohexane Etc.
These (b2) polyvalent isocyanate compounds are trimethylolpropane adduct-type modified products of the above polyisocyanates, burette-type modified products reacted with water, and isocyanurate-type modified products containing isocyanurate rings. Also good.

  Among these (b2) polyvalent isocyanate compounds, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2 from the viewpoint of excellent physical properties of the pressure-sensitive adhesive. , 6-tolylene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) and modified products thereof Preferably, from the viewpoint of weather resistance, one or more selected from HMDI, IPDI, and modified products thereof are more preferable.

The method for preparing the terminal isocyanate urethane prepolymer is not particularly limited. For example, the reactor includes a component (b1) and a component (b2), a urethanization catalyst added as necessary, and a solvent used as necessary. And the like, and the like.
The blending ratio of the components (b1) and (b2) is preferably NCO group / OH group (molar ratio) of 1.1 to 3.0, more preferably 1 from the viewpoint of leaving an isocyanate group at the terminal. It is preferable to mix and react so as to be 2 to 2.5. If it is 1.1 or more, since gelation can be avoided, the tendency to thicken can be suppressed. On the other hand, if it is 3.0 or less, the unreacted polyvalent isocyanate compound concentration in the terminal isocyanate urethane prepolymer does not become too high, and the reaction with the (b3) chain extender described later can proceed smoothly.

  The isocyanate group content (NCO%) in the terminal isocyanate urethane prepolymer is JIS K 1603, although it varies depending on the reactivity of the components (b1) and (b2) used and the blending amount of the (b3) chain extender. Is preferably 0.5 to 12% by mass, more preferably 1 to 4% by mass. If it is 0.5 mass% or more, the reaction with the (b3) chain extender can be sufficiently advanced, and if it is 12 mass% or less, the reaction with the (b3) chain extender is sufficiently controlled. be able to.

Although there is no restriction | limiting in particular as a catalyst used in terminal isocyanate urethane prepolymer formation reaction, A tertiary amine type compound, an organometallic type compound, etc. are mentioned.
Examples of the tertiary amine compound include triethylamine, triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) and the like.
Examples of organometallic compounds include tin compounds and non-tin compounds.
Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin Examples include acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate.
Non-tin compounds include, for example, titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, and lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate. Iron compounds such as iron 2-ethylhexanoate and iron acetylacetonate, cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate, zinc compounds such as zinc naphthenate and zinc 2-ethylhexanoate, Examples thereof include zirconium naphthenate.
Among these catalysts, DBTDL, tin 2-ethylhexanoate, and tetrabutyl titanate are preferable. In addition, you may use these catalysts individually or in combination of 2 or more types.

  The addition amount of the catalyst used in the reaction is preferably 0.0001 to 1 part by mass, more preferably 0.005 to 0.1 part by mass with respect to 100 parts by mass of the component (b1) from the viewpoint of reactivity. It is.

  Examples of the solvent used as necessary in the reaction include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, esters such as ethyl acetate and butyl acetate, and ketones such as methyl ethyl ketone (MEK). , Dimethylformamide, cyclohexanone, and the like. These solvents may be used alone or in combination of two or more.

  As reaction temperature in the said reaction, Preferably it is 120 degrees C or less, More preferably, it is 70-100 degreeC. If it is 120 degrees C or less, an alohanate reaction can suppress progress, the terminal isocyanate group prepolymer which has a predetermined molecular weight and structure can be synthesize | combined, and reaction rate can fully be controlled. The reaction time in the reaction is preferably 2 to 20 hours, for example, when the reaction temperature is 70 to 100 ° C.

The terminal isocyanate urethane prepolymer obtained as described above becomes a urethane resin by a chain extension reaction with the (b3) chain extender.
(B3) The chain extender is not particularly limited, but (b4) a compound having two hydroxyl groups and / or amino groups, and (b5) a compound having three or more hydroxyl groups and / or amino groups are preferably used. .

The component (b4) is not particularly limited as long as it is a compound having two hydroxyl groups and / or amino groups, but from the viewpoint of further preventing a decrease in adhesive strength, aliphatic diol, aliphatic diamine, alkanolamine, bisphenol. At least one compound selected from the group consisting of aromatic diamines is preferred.
Examples of the aliphatic diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptanediol. And alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol.
Examples of the aliphatic diamine include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and the like.
Examples of the alkanolamine include monoethanolamine, monopropanolamine, isopropanolamine and the like.
Examples of bisphenol include bisphenol A and the like.
Examples of the aromatic diamine include diphenylmethanediamine, tolylenediamine, xylylenediamine, and the like.

  The component (b5) is not particularly limited as long as it is a compound having three or more hydroxyl groups and / or amino groups, but a polyol such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, 1-amino Examples include amino alcohols such as 2,3-propanediol, 1-methylamino-2,3-propanediol, and N- (2-hydroxypropylethanolamine), and ethylene oxide or propylene oxide adducts of tetramethylxylylenediamine. .

The amino group and / or hydroxyl group in the components (b4) and (b5) are preferably a primary amino group, a secondary amino group, or a primary hydroxyl group from the viewpoint of reactivity with an isocyanate group.
The mass ratio [(b4) / (b5)] of the component (b4) and the component (b5) to be blended is preferably 70/30 to 100/0, more preferably 75/25 to 95/5, still more preferably 80/20 to 90/10. If the said mass ratio which shows the ratio of (b4) component with respect to (b5) component is 70/30 or more, even if it makes an adhesive layer thin, the fall of adhesive force can be suppressed and a urethane resin is obtained. In the chain extension reaction, gelation can be avoided and a desired pressure-sensitive adhesive can be obtained.

Examples of the chain extension reaction include (1) a method in which a solution of an isocyanate group-terminated prepolymer is charged into a reactor, and a chain extender is dropped into the reactor to cause a reaction, and (2) a chain extender is charged in the reactor. , A method in which a solution of an isocyanate group-terminated prepolymer is dropped and reacted, (3) a method in which a solution of an isocyanate group-terminated prepolymer is diluted with a solvent, and then a predetermined amount of a chain extender is charged into the reactor to react. Is mentioned. Since the isocyanate group gradually decreases and a uniform resin is easily obtained, the method (1) or (3) is preferable.
As the solvent, the same solvents that can be used for the terminal isocyanate group-terminated prepolymer formation reaction can be used.

  The addition amount of the chain extender (total addition amount of the components (b4) and (b5)) varies depending on the NCO group content of the isocyanate group-terminated prepolymer, but the NCO group of the urethane resin after chain extension is preferably The amount is 0.01 to 1.0 mol%, more preferably 0.05 to 0.2 mol%. If it is 0.01 mol% or more, chain extension can be sufficiently performed, and a urethane resin having a desired molecular weight can be obtained. Moreover, if it is 1.0 mol% or less, the phenomenon of rapidly thickening and gelling during the chain extension reaction can be suppressed.

The reaction temperature in the chain extension reaction is preferably 20 to 80 ° C. If it is 20 degreeC or more, chain extension reaction can be advanced at sufficient speed | rate. On the other hand, if it is 80 degrees C or less, reaction rate can fully be controlled and the urethane resin which has a desired molecular weight and structure will be obtained. When the chain extension reaction is performed in the presence of a solvent, the reaction temperature is preferably not higher than the boiling point of the solvent, and particularly preferably 40 to 60 ° C. in the presence of MEK and ethyl acetate.
The reaction time in the chain extension reaction is preferably 1 to 20 hours, for example, when the reaction temperature is 40 to 80 ° C.

An end terminator may be used to terminate the chain extension reaction.
Examples of the terminal terminator include a compound having only one hydrogen capable of reacting with an isocyanate group or a compound having only one amino group.
Examples of the compound having only one hydrogen capable of reacting with an isocyanate group include monool compounds such as methanol and ethanol.
As the compound having only one amino group, a compound having a primary amino group or a secondary amino group can be used, and examples thereof include diethylamine and morpholine.
A compound having one primary amino group has two reactive hydrogens, but the reactive hydrogen remaining after one reactive hydrogen has reacted is substantially less reactive. Equivalent to monofunctionality.
The addition amount of the terminal stopper is preferably 1 to 2 moles, more preferably 1.1 to 1.8 moles per mole of the terminal isocyanate group remaining after the chain extension reaction. If the addition amount of the terminal terminator is 1 mol or more, an isocyanate group does not remain after the termination reaction, and thus the obtained urethane resin is stable. On the other hand, if the addition amount of the terminal terminator is 2 mol or less, the production of a low molecular weight urethane resin can be suppressed.

  (B) The weight average molecular weight of a urethane resin becomes like this. Preferably it is 10,000-300,000, More preferably, it is 30,000-250,000, More preferably, it is 50,000-200,000. If it is 10,000 or more, it is preferable because the adhesive properties, particularly the holding power tends to be improved, and if it is 300,000 or less, gelation can be avoided.

<(C) Crosslinking agent>
The adhesive used in the present invention contains a crosslinking agent capable of reacting with the crosslinkable functional group in the component (A) from the viewpoint of increasing the cohesive force and obtaining a desired adhesive force.
Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent and an amine crosslinking agent, and an amino resin crosslinking agent.

Examples of the isocyanate crosslinking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, Polyvalent isocyanate compounds such as diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, lysine isocyanate Is mentioned.
The polyvalent isocyanate compound may be a trimethylolpropane adduct type modified product of the above compound, a burette type modified product reacted with water, or an isocyanurate type modified product containing an isocyanurate ring.

The epoxy-based crosslinking agent is not particularly limited as long as it has two or more epoxy groups or glycidyl groups in the molecule, but a polyfunctional epoxy compound containing two or more glycidyl groups in the molecule is preferable.
Examples of the polyfunctional epoxy compound containing two or more glycidyl groups in the molecule include diglycidyl ether of bisphenol A and oligomers thereof, diglycidyl ether of hydrogenated bisphenol A and oligomers thereof, orthophthalic acid diglycidyl ester, isophthalate Acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid glycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid di Glycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanedi Diglycidyl ether and polyalkylene glycol diglycidyl ether, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane di or tri Examples thereof include glycidyl ether, pentaerythritol di or triglycidyl ether, triglycidyl ether of glycerol alkylene oxide adduct, diglycidyl amine such as diglycidyl aniline, and the like.

  Although it does not specifically limit as an aziridine type crosslinking agent, As a specific example, 1,1'- (methylene-di-p-phenylene) bis-3, 3- aziridinyl urea, 1,1'- (hexamethylene) Bis-3,3-aziridinyl urea, 2,4,6-triaziridinyl-1,3,5-triazine, trimethylolpropane-tris- (2-aziridinylpropionate) and the like can be mentioned.

  Examples of the metal chelate-based crosslinking agent include compounds in which acetylacetone, ethyl acetoacetate, and the like are coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. Etc.

  Examples of amine-based crosslinking agents include polyamines such as aliphatic polyamines (for example, triethylenetetramine, tetraethylenepentamine, ethylenediamine, N, N-dicinnamylidene-1,6-hexanediamine, trimethylenediamine, hexamethylenediamine carbamate, ethanolamine. 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxa-2-spiro [5.5] undecane and the like) and salts thereof; aromatic polyamines (for example, diaminodiphenylmethane, xylylenediamine) , Phenylenediamine, diaminodiphenylsulfone and the like.

  Examples of amino resin-based crosslinking agents include methoxylated methylol urea, methoxylated methylol N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like. Preferably, methoxylated methylol melamine, butoxylated methylol melamine, methylolated benzoguanamine and the like can be mentioned.

  Among these, an isocyanate-based crosslinking agent is preferable from the viewpoint of obtaining high adhesive force even when the pressure-sensitive adhesive layer is thinned. In addition, you may use said crosslinking agent individually or in combination of 2 or more types.

  The content of the crosslinking agent is preferably 0.01 to 8 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B) from the viewpoint of obtaining high adhesive strength even if the pressure-sensitive adhesive layer is thinned. More preferably, it is 0.05-5 mass parts, More preferably, it is 0.1-3 mass parts.

<Other ingredients>
The pressure-sensitive adhesive used in the present invention can be blended with other components as long as the effects of the present invention are not impaired. Examples of other components include ultraviolet absorbers, antioxidants, preservatives, antifungal agents, tackifiers, plasticizers, antifoaming agents, and wettability adjusting agents.

[Base material]
As the base material used in the present invention, since the marking film of the present invention is also used as a substitute for coating, a substrate having a small shrinkage ratio and not so hard is preferable from the viewpoint of application workability.
Examples of such base materials include vinyl chloride resins, polyester resins such as polyethylene terephthalate and amorphous polyethylene terephthalate, polyolefin resins such as polyethylene, polypropylene, and propylene-ethylene copolymers, acrylic resins, and polycarbonate resins. , A base film formed into a film using a resin composition containing fluorine resin, thermoplastic urethane resin, urethane acrylate resin, polyester thermoplastic elastomer, polyolefin thermoplastic elastomer, and mixtures thereof, etc. Is mentioned.

  Moreover, you may mix | blend dye, a pigment, etc. with the said resin composition for the purpose of coloring a base material. The blending amount of the dye or pigment is preferably 1 to 40 parts by mass, more preferably 10 to 35 parts by mass, and still more preferably 15 to 30 parts by mass with respect to 100 parts by mass of the resin.

These base films may be subjected to a surface treatment by an oxidation method or a concavo-convex method on one side or both sides as desired for the purpose of improving the adhesion with the pressure-sensitive adhesive layer or coating layer provided thereon. it can.
Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.
Examples of the unevenness method include a sand blast method and a solvent treatment method.
These surface treatment methods are appropriately selected according to the type of the substrate, but the corona discharge treatment method is preferred from the viewpoint of improving the adhesiveness of the pressure-sensitive adhesive layer and the operability. Moreover, what gave the primer process to the single side | surface or both surfaces of a base material can also be used.

[Peeling material]
The marking film of the present invention may further have a release material on the pressure-sensitive adhesive layer.
Although there is no restriction | limiting in particular as a peeling material to be used, From the viewpoint of the ease of handling, the peeling sheet which apply | coated the release agent on the base material is preferable. The release sheet may be one in which a release agent is applied to only one surface of the substrate and subjected to a release treatment, or may be one in which a release agent is applied to both surfaces of the substrate and subjected to a release treatment.
Examples of the base material of the release sheet include paper base materials such as glassine paper, coated paper, cast coated paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, or polyethylene terephthalate, polybutylene terephthalate. And polyester films such as polyethylene naphthalate, and plastic films such as polyolefin films such as polypropylene and polyethylene.
Examples of the release agent include rubber elastomers such as silicone resins, olefin resins, isoprene resins, and butadiene resins, long chain alkyl resins, alkyd resins, and fluorine resins.

Although there is no restriction | limiting in particular as thickness of a peeling sheet, Usually, 20-200 micrometers, Preferably it is 25-150 micrometers.
The thickness of the release sheet of the release sheet after drying is not particularly limited. However, when the release agent is applied in a solution state, it is preferably 0.01 to 2.0 μm, more preferably 0.03. ˜1.0 μm.
When using a plastic film as a base material, the thickness of the base material of the release sheet is preferably 3 to 50 μm, more preferably 5 to 40 μm.

[Coating layer (antifouling layer)]
The marking film of the present invention may further have a coating layer or an antifouling layer on the surface of the substrate opposite to the surface on which the pressure-sensitive adhesive layer is formed.
As the coating layer or antifouling layer, for example, from a cross-linked product of an oil-modified alkyd resin, a fatty acid-modified alkyd resin, or a silicone-modified alkyd resin obtained by a condensation reaction of a polyhydric alcohol, a polybasic acid and a corresponding modifier. Can be formed.
When these layers are provided, the thickness of the layers needs to be adjusted so that the total thickness of the marking film at the time of application is 25 μm or less. The specific layer thickness is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[Manufacturing method of marking film]
The manufacturing method of the marking film of the present invention is not particularly limited.
For example, if it is the marking film 1a shown to Fig.1 (a), an adhesive can be apply | coated and dried on one surface of the base material 11, and the adhesive layer 12 can be formed and produced.
In the case of the marking film 1b shown in FIG. 1B, a pressure-sensitive adhesive is applied on the surface of the release material 13 and dried to produce a release material with the pressure-sensitive adhesive layer 12, and then the pressure-sensitive adhesive layer 12 is used. And the base material 11 can be bonded together. It is also possible to remove the release material to obtain the marking film 1a shown in FIG.
Further, a coating agent is applied to the opposite surface of the marking film 1b on which the adhesive layer 12 of the base material 11 is formed, and dried to form a coating layer (antifouling layer) 14 as shown in FIG. It can also be set as the marking film 1c.
The coating layer (antifouling layer) 14 may be formed by directly applying the coating agent to the substrate 11 as described above, or by applying the coating agent to the release material and drying it to form the coating layer ( After forming the antifouling layer 14, the coating layer (antifouling layer) 14 and the substrate 11 may be bonded to each other.

(Formation of adhesive layer)
When applying the pressure-sensitive adhesive to a substrate or a release material, it is preferable to dilute the pressure-sensitive adhesive with an organic solvent to form a pressure-sensitive adhesive solution in order to easily form a thin pressure-sensitive adhesive layer.
Examples of the organic solvent to be used include toluene, ethyl acetate, methyl ethyl ketone, and the like. By blending these organic solvents into a pressure-sensitive adhesive solution having an appropriate solid content concentration, a thin pressure-sensitive adhesive layer can be easily formed.
As solid content concentration of an adhesive solution, Preferably it is 5-60 mass%, More preferably, it is 10-40 mass%. If the amount is 5% by mass or more, the amount of the solvent used is sufficient, and if it is 60% by mass or less, the viscosity becomes appropriate and the workability is improved when the adhesive solution is applied.
In preparing the resin contained in the pressure-sensitive adhesive, when the resin is prepared in a state of being contained in an organic solvent, the same solid content as the organic solvent used in the resin preparation is used. You may dilute so that.

The method for forming the pressure-sensitive adhesive layer on the substrate or the release material is not particularly limited, and examples thereof include a method for forming a pressure-sensitive adhesive (solution) containing the above organic solvent by a known coating method.
Examples of the coating method include known methods such as spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.
In addition, after applying to a base material or a release material, in order to prevent residual solvent and low boiling point components and to allow the crosslinking (reaction) to proceed and develop a predetermined adhesiveness when a crosslinking agent is blended It is preferable to heat-treat.
As temperature conditions of heat processing, Preferably it is 70-150 degreeC, More preferably, it is 80-120 degreeC. The treatment time for the heat treatment is preferably 30 seconds to 5 minutes, more preferably 40 to 180 seconds.

(Formation of base film)
A commercially available product may be used as the substrate, but a substrate film colored by adding a pigment or the like may be used.
As a method for producing a colored substrate film, for example, a substrate resin such as the above-mentioned vinyl chloride resin is dissolved and dispersed in an organic solvent such as dimethylformamide (DMF), and polyester, dioctyl phthalate, etc. and an organic solvent are used. A method of preparing a resin composition solution for a substrate by adding a pigment that has been pasted by applying the solution to a release film or the like by the application method described above, and removing the release film after drying is given. It is done.

[Characteristics and applications of marking film]
The adhesive strength of the marking film of the present invention is preferably 5.0 N / 25 mm or more, more preferably 6.0 N / 25 mm or more, still more preferably 6.5 N under the conditions of 23 ° C. and 50% RH (relative humidity). / 25 mm or more. In addition, in this invention, the value of the said adhesive force means the value measured by the method as described in an Example.

The marking film of the present invention can be used both indoors and outdoors, but has excellent weather resistance and is less susceptible to dirt, water stains, etc., and therefore is more suitable for outdoor use.
Moreover, the shape of the marking film of the present invention is not particularly limited, and may be a shape such as a rectangle or a circle, or may be a shape in which characters or designs are formed by cutting the film into characters or designs. However, since the marking film of the present invention is very thin, the difference in level from the base when applied to the adherend is small, and it is possible to suppress dirt and water stains that are likely to occur at the end of the marking film. . Therefore, when the marking film of the present invention has a shape in which characters and designs are formed, it is easier to exhibit the effect of suppressing dirt and water stains that easily occur at the end of the shape.

  Furthermore, since the marking film of the present invention has a very thin thickness, even if the base film is further laminated on the marking film of the present invention, the shape of the marking film of the present invention located below is the base film. It is possible to suppress floating on the surface. The effect will be described in detail with reference to FIGS.

  FIG. 3 is a cross-sectional view of a conventional marking film, showing how the film is used. FIG. 3A shows a conventional marking film 100 having a base 110 and an adhesive layer 120 on an adherend 21 such as a signboard so that the adhesive layer 120 overlaps the surface of the adherend 21. Shows the state of pasting together. Then, as shown in FIG. 3B, when the base film 22 is overlaid from above the marking film 100, a raised portion 22 a in the shape of the marking film 100 is seen on the surface of the base film 22. The thickness Yb of the raised portion 22a depends on the thickness of the base material 110 and the pressure-sensitive adhesive layer 120 that constitute the marking film 100. In the conventional marking film 100, since the base material 110 and the pressure-sensitive adhesive layer 120 are thick, the thickness Yb of the floating portion 22a is large, and the lifting of the shape of the marking film 100 on the surface of the base film tends to be conspicuous.

On the other hand, FIG. 2 is sectional drawing of this film which shows the usage aspect of the marking film of this invention. As shown in FIG. 2A, the marking film 1 a of the present invention having the base material 11 and the pressure-sensitive adhesive layer 12 is placed on the adherend 21 such as a signboard, and the pressure-sensitive adhesive layer 12 is attached to the adherend 21. Let us consider a case (FIG. 2 (b)) in which the substrate film 22 is laminated so as to overlap the surface and the base film 22 is further laminated thereon. The marking film 1a of the present invention has a very thin base material 11 and pressure-sensitive adhesive layer 12. Therefore, as shown in FIG. The thickness Ya of the raised portion 22a in the shape of the marking film 1a is very small. Since the thickness Ya in FIG. 2B is much smaller than the thickness Yb in FIG. 3B, the lifting of the shape of the marking film 1a on the surface of the base film 22 is suppressed and is not conspicuous.
Therefore, the marking film of the present invention can suppress the lifting of the shape of the marking film on the surface of the base film even if the base film is further laminated on the marking film of the present invention.

In addition, an antifouling film may be laminated on the marking film in order to prevent adhesion of dirt on the surface. When a general marking film is used, if a marking film having the shape of a letter or design is pasted and then laminated from the top of the film, there is a large step with the base film and a large gap is generated. To do. During laminating work, air may enter through the gaps and may not be successfully laminated.
On the other hand, if it is the marking film of this invention, since the level | step difference with the base film etc. after affixing is small, a clearance gap is hard to produce and it can prevent the penetration | invasion of the air in the case of a lamination operation.

The weight average molecular weight (Mw) and the thickness of each layer of the marking film shown in the description of the following examples are values measured as follows.
(1) Weight average molecular weight (Mw)
It is a value determined by standard polystyrene conversion, measured with the following equipment and conditions.
Device name: “HLC-8220GPC” (manufactured by Tosoh Corporation)
Column: “TSKgelGMHXL”, “TSKgelGMMHXL”, and “TSKgel2000HXL” (all manufactured by Tosoh Corporation) connected in sequence Developing solvent: Tetrahydrofuran Injection volume: 80 μl
Measurement temperature: 40 ° C
Flow rate: 1.0 mL / min
Detector: Differential refractometer (2) Thickness measurement The thickness of each layer of the marking film and the total thickness of the film after application are in accordance with JIS K7130. 02 ").

Production Example 1
(Preparation of acrylic copolymer (A1) solution)
As a monomer component, 95 parts by mass of butyl acrylate and 5 parts by mass of acrylic acid, 200 parts by mass of ethyl acetate as a solvent, and 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator are placed in a reactor. Mixed. After deaeration with nitrogen gas for 4 hours, the temperature was gradually raised to 60 ° C., and then the polymerization reaction was carried out with stirring for 24 hours to obtain a solution (solid content) of an acrylic copolymer (A1) having a weight average molecular weight of 650,000. Concentration: about 33% by mass) was obtained.

Production Example 2
(Preparation of acrylic copolymer (A2) solution)
As a monomer component, 90 parts by mass of butyl acrylate and 10 parts by mass of acrylic acid, 200 parts by mass of ethyl acetate as a solvent, and 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator are placed in a reactor. Mixed. After deaeration with nitrogen gas for 4 hours, the temperature was gradually raised to 60 ° C., and then the polymerization reaction was carried out with stirring for 24 hours to obtain a solution (solid content) of an acrylic copolymer (A2) having a weight average molecular weight of 650,000. Concentration: about 33% by mass) was obtained.

Production Example 3
(Preparation of a solution of urethane resin (B1))
(B1) 100 parts by mass of polypropylene glycol (weight average molecular weight: 2000) as the diol, (b2) 10.1 parts by mass of hexamethylene diisocyanate (NCO group / OH group (molar ratio)) = 1.2 as the polyvalent isocyanate compound ), 0.01 parts by mass of dibutyltin dilaurate was mixed as a catalyst, the temperature was gradually raised to 85 ° C., and the mixture was stirred for 2 hours to obtain a terminal isocyanate urethane prepolymer.
To the obtained terminal isocyanate urethane prepolymer, 110 parts by mass of toluene was added and the mixture was cooled to room temperature. Then, 0.40 part by mass of 2-aminoethanol corresponding to component (b4) was added dropwise as a chain extender, and gradually up to 70 ° C. After the temperature was increased, the mixture was stirred for 2 hours to obtain a urethane resin (B1) solution (solid content concentration: about 50.2% by mass) having a weight average molecular weight of 140,000.

Production Example 4
(Preparation of a solution of urethane resin (B2))
(B1) 100 parts by mass of polypropylene glycol (weight average molecular weight: 2000) as the diol, (b2) 10.1 parts by mass of hexamethylene diisocyanate (NCO group / OH group (molar ratio)) = 1.2 as the polyvalent isocyanate compound ), 0.01 parts by mass of dibutyltin dilaurate was mixed as a catalyst, the temperature was gradually raised to 85 ° C., and the mixture was stirred for 2 hours to obtain a terminal isocyanate urethane prepolymer.
After adding 110 mass parts of toluene to the obtained terminal isocyanate urethane prepolymer and cooling to room temperature, 0.48 mass parts of 1,4-butanediol corresponding to the component (b4) is added dropwise as a chain extender, and ( b5) 0.12 part by mass of trimethylolpropane, which is a component, was added dropwise, gradually heated to 70 ° C., stirred for 2 hours, and a solution of urethane resin (B2) having a weight average molecular weight of 140,000 (solid content concentration: About 50.2 mass%).

Example 1
(1) Preparation of pressure-sensitive adhesive (A) As an acrylic copolymer, 10 parts by mass (solid content) of an ethyl acetate solution of the acrylic copolymer (A1) prepared in Production Example 1, (B) As a urethane resin, 90 parts by mass (solid content) of a toluene solution of the urethane resin (B1) prepared in Production Example 2, (C) As a crosslinking agent, an isocyanate-based crosslinking agent (trade name “Coronate L”, manufactured by Nippon Polyurethane Co., Ltd. A mixture of 2.25 parts by mass (solid content) of an ethyl acetate solution (solid content 75% by mass) of the modified product (trimethylolpropane adduct) was diluted with toluene so that the solid content was 10% by mass, and then adhered. A solution of the agent was prepared.

(2) Preparation of substrate (preparation of vinyl chloride film)
100 parts by mass of vinyl chloride resin (BF Goodrich, trade name “Geon 178”, weight average polymerization degree 1800, resin fine particles are spherical), adipic acid polyester plasticizer (manufactured by Dainichi Seika Co., Ltd., product) Name "Fine Sizer NS-4070", weight average molecular weight: 4000) 9 parts by mass, barium zinc-based thermal stabilizer (metal soap type thermal stabilizer, manufactured by Katsuta Processing Co., Ltd., trade name "SB-9301"), 4 parts by mass, 1 part by mass of a benzophenone-based ultraviolet absorber (made by Cytec Co., Ltd., trade name “Siasorb UV-531”), inorganic / organic pigment toner (mixed toner of the plasticizer and pigment (made by Dainichi Seika Co., Ltd., trade name “VT Color Gray”) 31.3 parts by mass (including plasticizer equivalent to 23.27 parts by mass), dispersion solvent (manufactured by Gordo Solvents, trade name “Butyl Cellosolve”, glycol ethers) 24.2 parts by mass of boiling point 166 to 173 ° C.) and 24.2 parts by mass of dilute dispersion solvent (manufactured by Gordo Solvent Co., Ltd., trade name “SS-100”, aromatic hydrocarbon solvent, boiling point 160 to 169 ° C.) Thus, a solution of a resin composition for a substrate made of a vinyl chloride resin was obtained.
The solution of the resin composition for preparing a substrate is placed on an alkyd-treated release film (product name “SP-PET75 AL-5” manufactured by Lintec Corporation) so that the thickness of the substrate after drying becomes 10 μm. After apply | coating and drying at 100 degreeC for 1 minute, the peeling film was peeled off and the vinyl chloride film used as a base material was produced.

(3) Preparation of marking film The above pressure-sensitive adhesive solution is applied to a silicone-treated 38 μm polyester film (product name “SP-PET 381031” manufactured by Lintec Corporation), and the thickness of the pressure-sensitive adhesive layer after drying is 5 μm. After coating and drying at 100 ° C. for 1 minute, an adhesive sheet was prepared.
The pressure-sensitive adhesive layer surface of this pressure-sensitive adhesive sheet and the surface of the vinyl chloride film were bonded together to produce a marking film 1.

Example 2
A marking film 2 was produced in the same manner as in Example 1 except that the thickness of the substrate after drying was 15 μm.

Example 3
A marking film 3 was produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer after drying was 8 μm.

Example 4
(Production of urethane acrylate film)
150 parts by mass of polycarbonate diol (manufactured by Nippon Polyurethane, product name “N-983”), 40 parts by mass of hexamethylene diisocyanate (manufactured by Nippon Polyurethane, product name “Coronate HL”), and 0.05 part by mass of dibutyltin dilaurate In addition to 200 mass parts of toluene, it was made to react at 80 degreeC by nitrogen atmosphere, and the urethane resin composition was obtained.
The obtained urethane resin composition was reacted with 10 parts by mass of 2-hydroxyethyl methacrylate caprolactone adduct (product name “FM-3”, manufactured by Daicel Chemical Industries, Ltd.) to obtain a urethane prepolymer solution.
A solution obtained by mixing 125 parts by mass of toluene, 75 parts by mass of isopropyl alcohol, 100 parts by mass of methyl methacrylate, and 5 parts by mass of benzoyl peroxide with 200 parts by mass of this urethane prepolymer solution was added at 100 ° C. in a nitrogen atmosphere over 3 hours. A urethane-acrylic copolymer having a mass ratio of a target urethane prepolymer-derived portion and a (meth) acrylic acid alkyl ester-derived portion of 50:50 was obtained by dropwise addition and reaction.
To 100 parts by mass of the urethane-acrylic copolymer obtained above, 10 parts by mass of isopropyl alcohol as a diluting solvent was further mixed and stirred, and then allowed to stand for 6 hours or more to degas naturally to obtain a solution-like urethane acrylate. A solution of a resin composition for a substrate made of a resin was obtained.
The solution of the resin composition for preparing a substrate is placed on an alkyd-treated release film (product name “SP-PET75 AL-5” manufactured by Lintec Corporation) so that the thickness of the substrate after drying becomes 10 μm. After apply | coating and drying at 100 degreeC for 1 minute, the peeling film was peeled off and the urethane acrylate film used as a base material was produced.
And the marking film 4 was produced like Example 1 except having used the said "urethane acrylate film" with a thickness of 10 micrometers as a base material.

Example 5
Example 1 except that the above-mentioned “urethane acrylate film” with a thickness adjusted to 15 μm was used as a base material and an “acrylic pressure-sensitive adhesive (product name“ PK ”” manufactured by Lintec Corporation) was used as the pressure-sensitive adhesive. Thus, a marking film 5 was produced.

Example 6
(A) A marking film 6 was prepared in the same manner as in Example 1 except that 10 parts by mass (solid content) of the acrylic copolymer (A2) prepared in Production Example 2 was used as the acrylic copolymer. Produced.

Example 7
(A) 20 parts by mass (solid content) of the acrylic copolymer (A1) prepared in Production Example 1 as an acrylic copolymer, and (B) urethane resin (B2) prepared in Production Example 4 as a urethane resin ) Was used in the same manner as in Example 1 except that 80 parts by mass (solid content) was used.

Comparative Example 1
A marking film 8 was produced in the same manner as in Example 1 except that the thickness of the substrate after drying was 50 μm.

Comparative Example 2
A marking film 9 was produced in the same manner as in Example 1 except that the thickness of the substrate after drying was 25 μm.

Comparative Example 3
A marking film 10 was produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer after drying was 15 μm.

About the marking films 1-10 produced as mentioned above, the following tests were done and evaluated. The evaluation results are shown in Table 1. In addition, when the peeling film was attached to the base film surface and the adhesive layer surface, the peeling film was peeled off at an appropriate time, and the test was performed.
(Test 1) Dirt adhesion test A marking film (product name “Buccal 9002”, 100 mm × 100 mm, manufactured by Lintec Co., Ltd.) serving as a base film was attached to the entire surface of the iron plate. And each marking film produced in the example and the comparative example was cut out so as to have the shape of the Chinese character “field” (the length of the outer piece of the rice field is 50 mm). Each marking film having a shape was stuck on the base film and left for 24 hours.
After that, it was put into a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.), and after 3000 hours, the presence or absence of dirt on the end of each marking film having the shape of a “field” was visually observed. confirmed. Table 1 describes “◯” when there is no such information, and “X” when it is confirmed that they are present.

(Test 2) Floatability test On each marking film having the shape of a “rice” produced in Test 1, a commercially available marking film (product name “Buccal 9002”, 100 mm × 100 mm, manufactured by Lintec) Was affixed to the entire surface, and the presence or absence of the lifting of the “ta” character was visually confirmed. Table 1 describes “◯” when there is no lifting, and “x” when it is confirmed.

(Test 3) Adhesive force measurement After the marking film was prepared, a marking film test piece cut to 25 mm × 300 mm was attached to an adherend (SUS304 steel plate) in an environment of 23 ° C. and 50% RH (relative humidity). A test sample was obtained. Based on JIS Z0237: 2000, the adhesive strength at 24 hours after application was measured at a pulling rate of 300 mm / min by a 180 ° peeling method.

From Table 1, in the marking films 1 to 7 produced in Examples 1 to 7 of the present invention, no stains on the ends and traces of scales were confirmed, and no lifting of the shape of the “field” was observed. Moreover, it turns out that the adhesive force is also excellent.
On the other hand, it was confirmed that the marking films 8 to 10 produced in Comparative Examples 1 to 3 had traces of stains and scales at the ends, and the lifting of the shape of the “rice” was also observed.

  The marking film of the present invention can suppress the adhesion of dirt and traces of water scale, and suppresses the lifting of the shape of the marking film on the surface of the base film when a new base film is overlaid, and Has excellent adhesive strength. Therefore, the marking film is suitable for decorative use such as a signboard used mainly outdoors.

1a, 1b, 1c Marking film 11 Base material 12 Adhesive layer 13 Release material 14 Coating layer (antifouling layer)
21 Substrate 22 Base film 22a Floating portion 100 (under the base film) Conventional marking film 110 Base material 120 (with conventional marking film) Adhesive layer (with conventional marking film)

Claims (11)

A marking film having a substrate and an adhesive layer,
Marking film in which the total thickness of the film after pasting is 25 μm or less, and the ratio of the thickness of the pressure-sensitive adhesive layer to the thickness of the base material [pressure-sensitive adhesive layer / base material] is 0.02 to 0.85 .   The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer contains (A) an acrylic copolymer having a crosslinkable functional group, (B) a urethane resin, and (C) a crosslinking agent. Marking film as described in.   (B) The urethane resin is obtained by reacting (b3) a chain extender with a terminal isocyanate urethane prepolymer obtained by reacting (b1) a diol with (b2) a polyvalent isocyanate compound. b3) the chain extender is (b4) a compound having two hydroxyl groups and / or amino groups, and (b5) a compound having three or more hydroxyl groups and / or amino groups, (b4) component and (b5) component The marking film according to claim 2, wherein a mass ratio [(b4) / (b5)] is 70/30 to 100/0.   The marking film according to claim 3, wherein the component (b4) has a hydroxyl group and an amino group.   (B1) The marking film according to claim 3 or 4, wherein the diol is a glycol having a weight average molecular weight of 1,000 to 3,000.   The marking film according to any one of claims 2 to 5, wherein the crosslinkable functional group of the component (A) is derived from an ethylenically unsaturated carboxylic acid or a (meth) acrylic acid hydroxyalkyl ester.   The mass ratio [(A) / (B)] of (A) acrylic copolymer and (B) urethane resin is 1/99 to 40/60. Marking film.   (A) The marking film according to any one of claims 2 to 7, wherein the acrylic copolymer has a weight average molecular weight (Mw) of 300,000 to 1,500,000.   The marking film in any one of Claims 1-8 whose thickness of an adhesive layer is 0.5-10 micrometers and whose thickness of a base material is 1-20 micrometers.   The marking film according to any one of claims 1 to 9, wherein the marking film is used outdoors and is formed in a shape of a character or a design.   The marking film according to any one of claims 1 to 10, wherein the marking film is overlaid with another marking film.