JP2004326017A - Microcapsule-containing easy-to-peel label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a pressure-sensitive easy-to-peel label has both sufficient adhesive strength and peeling easiness and to realize, especially, quick peeling property, excellent confidentiality, and forgery prevention. <P>SOLUTION: Used is the easy-to-peel label which has microcapsules 12 to be destroyed with pressure, sandwiched between a binder layer 11 and a pressure-sensitive adhesive layer 13 on a base body 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a label which can be stuck with sufficient strength by applying a low pressure and can be easily peeled off by applying a high pressure.
[0002]
[Prior art]
A label that can be applied by applying pressure is called a pressure-sensitive label, and a pressure-sensitive adhesive layer is formed on an adhesive surface. Pressure-sensitive adhesives are also called self-adhesive pressure-sensitive adhesives, which are bonded by an anchor effect generated by applying pressure.Natural rubber-based adhesives, acrylic adhesives, epoxy-based adhesives and many other pressure-sensitive adhesives Adhesive is used.
[0003]
Among these pressure-sensitive labels, in addition to being able to be sufficiently adhered at a predetermined pressure, such as information-concealing labels, information-carrying labels, and decorative labels, it is required that they can be easily peeled off as necessary. There is something.
[0004]
For example, in the case of an information concealing label, an information concealing label is attached to a confidential information portion of a postcard having confidential information, and mail is sent in a state where the confidential information is concealed. Read. Specific examples of such an information hiding label include, for example, attendance confirmation and voting at a general meeting of shareholders. In such applications, the sender applies pressure by itself and affixes the information concealing label to the postcard, and then achieves and maintains a sufficient adhesive strength of the information concealment label during mailing, thus making the information concealing unnecessary. It is required that the label be peeled off or that a third party cannot easily peel off the information hiding label and cannot steal confidential information. Further, when the postcard arrives at the recipient and obtains the confidential information, it is necessary that the information concealing label can be peeled off easily, at high speed, and at low cost. In particular, the number of postcards to be processed can reach hundreds of thousands per day, and when the number of postcards is large, it is particularly important that the information concealing label can be easily peeled off at high speed and at low cost.
[0005]
In the case of an information carrying label and a decoration label, for example, an information carrying label having information on the contents of the container or a decoration label for improving the design is attached to the container, and all the contents of the container are used. After the container is no longer needed, the information carrying label and the decorative label are peeled off from the container, and the container is recycled. In such applications, while the contents are in the container, sufficient adhesion strength between the information carrying label and the decorative label is realized and maintained, and the information carrying label and the decorative label are unnecessarily used. It is required not to peel off. Further, when the container is no longer required, it is necessary that the information carrying label and the decorative label can be peeled off easily, at high speed, and at low cost. In particular, when the container is a beverage bottle or the like, the number of containers to be processed may reach hundreds of thousands per day, and when the number of containers is large, the information carrying label and the decorative label can be easily prepared. It is particularly important to be able to peel at high speed and at low cost.
[0006]
From the above viewpoints, a number of proposals have been made for pressure-sensitive labels that can be easily peeled off after use. For example, Patent Documents 1 and 2 describe the use of microcapsules.
[0007]
[Patent Document 1]
JP 07-219439 A [Patent Document 2]
JP-A-11-263951
[Problems to be solved by the invention]
However, the conventionally proposed pressure-sensitive easy-peeling label may have the following problems.
[0009]
First, there were cases where it was difficult to achieve both sufficient adhesive strength and easy peelability. That is, in the case of a pressure-sensitive label that can be peeled off easily, at high speed, and at low cost, the adhesive strength is insufficient, and the pressure-sensitive label may peel off unnecessarily, or a third party may easily peel off the pressure-sensitive label. Was. On the other hand, by providing sufficient adhesive strength to prevent unnecessary peeling of the pressure-sensitive label or to prevent the pressure-sensitive label from being easily peeled off by a third party, the pressure-sensitive label can be easily, quickly, and quickly removed when necessary. In some cases, it could not be peeled off at low cost.
[0010]
Second, even when sufficient adhesive strength and easy peelability can be achieved at the same time, when the number of pressure-sensitive labels increases, the high-speed peelability may be insufficient. When the number of pressure-sensitive labels is large, a pressure-sensitive label that can be peeled off at high speed is required.
[0011]
Third, confidentiality and anti-tampering properties were sometimes insufficient.
[0012]
In view of the above situation, an object of the present invention is to provide a pressure-sensitive and easy-peeling label which can achieve both sufficient adhesive strength and easy-peeling property, and in particular, can realize high-speed peeling property.
[0013]
It also aims to improve confidentiality and tamper resistance.
[0014]
[Means for Solving the Problems]
According to the present invention for achieving the above object, there is provided an easily peelable label in which microcapsules which are broken by pressure are sandwiched on a substrate by a binder layer and a pressure-sensitive adhesive layer.
[0015]
FIG. 1A shows an example of the pressure-sensitive easily peelable label of the present invention. A binder layer 11 is formed on a base 10, and microcapsules 12 form a microcapsule layer on the binder layer. The microcapsules are held on the base by the binder layer. Further, a pressure-sensitive adhesive layer 13 is formed on the microcapsule layer, and the adhesive surface 14 is in contact with the adherend.
[0016]
The pressure-sensitive adhesive layer is formed by selecting a pressure-sensitive adhesive that has sufficient adhesive strength and can maintain sufficient adhesive strength. The pressure-sensitive easily peelable label on which such a pressure-sensitive adhesive layer is formed can be adhered to an adherend by an appropriate adhesive pressure.
[0017]
For example, in the case of an information concealing label to be attached to the confidential information section of a postcard having confidential information, the sender can apply the information concealing label by himself and realize sufficient adhesive strength. In this case, the adhesive pressure is preferably 1 Pa or more, more preferably 10 Pa or more, and even more preferably 100 Pa or more, from the viewpoint of achieving sufficient adhesiveness. In addition, from the viewpoint of suppressing breakage of the microcapsules during bonding, the pressure is generally 100 MPa or less, preferably 1 MPa or less, more preferably 500 kPa or less, and still more preferably 10 kPa or less.
[0018]
Further, in the case of an information carrying label having information on the contents of the container or a decorative label for improving the design of the container, the label is adhered by a suitable adhesive means such as an adhesive press or an adhesive roller.
[0019]
When an adhesive press is used, the bonding pressure is preferably 1 Pa or more, more preferably 10 Pa or more, and even more preferably 100 Pa or more, from the viewpoint of achieving sufficient adhesiveness. In addition, from the viewpoint of suppressing breakage of the microcapsules during bonding, the pressure is preferably 100 MPa or less, more preferably 10 MPa or less, and still more preferably 1 MPa or less.
[0020]
When an adhesive roller is used, the adhesive pressure is preferably at least 30 mN / m, more preferably at least 300 mN / m, even more preferably at least 3 N / m. On the other hand, from the viewpoint of realizing high-speed peeling, it is preferably 100 kN / m or less, more preferably 10 kN / m or less, and still more preferably 1 kN / m or less.
[0021]
The pressure-sensitive easily peelable label adhered to the adherend by applying the adhesive pressure is peeled off by applying a peeling pressure higher than the adhesive pressure. The peeling pressure is equal to or higher than the pressure at which the microcapsules forming the microcapsule layer are broken. In this case, as shown in FIG. 1B, since the microcapsules are broken, the pressure-sensitive easily peelable label is peeled off. In this case, the microcapsule layer functions as a release layer, and the pressure-sensitive easy-release label is released only by applying a release pressure, so that easy and high-speed release can be realized. Further, since heating, moisture, and a special device other than the peeling pressure are not required, inexpensive peeling can be realized.
[0022]
The method of applying the peeling pressure is not particularly limited as long as it can realize easy, high-speed, and inexpensive peeling. However, from the viewpoint of realizing high-speed peeling, a method using a peeling press, a peeling roller, or the like is particularly preferable. In this case, the microcapsules are destroyed simply by passing the pressure-sensitive easily peelable label adhered to the adherend between the peeling press or the peeling roller, and the pressure-sensitive easily peelable label is easily and rapidly peeled from the adherend. it can. Further, since heating, moisture, and a special device other than the peeling pressure are not required, inexpensive peeling can be realized.
[0023]
When a peeling press is used, the peeling pressure is preferably 5 kPa or more, more preferably 50 kPa or more, and further preferably 500 kPa or more, from the viewpoint of achieving sufficient peelability. In addition, from the viewpoint of realizing high-speed peeling, 100 GPa or less is preferable, 10 GPa or less is more preferable, and 1 GPa or less is further preferable.
[0024]
When a peeling roller is used, the peeling pressure is preferably at least 100 N / m, more preferably at least 1 kN / m, even more preferably at least 10 kN / m. On the other hand, from the viewpoint of realizing high-speed peeling, it is preferably 10 MN / m or less, more preferably 1 MN / m or less, and still more preferably 100 kN / m or less.
[0025]
In particular, in the case of using a peeling roller, the pressure-sensitive easy-peeling label adhered to the adherend can be continuously passed through the peeling roller, and the rotation of the peeling roller can be performed at a high speed. Can be realized.
[0026]
As is clear from the above description, the pressure-sensitive easily peelable label of the present invention can adhere to the adherend at a low pressure (adhesion pressure) within a range where the microcapsules are not broken, and can realize sufficient adhesive strength. To peel off the release label, a high pressure (peeling pressure) is applied to break the microcapsules, whereby the pressure-sensitive easy release label is peeled off. The following advantages can be realized by using such a pressure-sensitive easy-peeling label.
[0027]
First, both sufficient adhesive strength and easy peelability can be achieved. That is, even in the case of a pressure-sensitive label that can be peeled off easily, at high speed, and at low cost, sufficient adhesive strength can be achieved and continued, and the pressure-sensitive label can be peeled off unnecessarily, or a third party can easily peel off the pressure-sensitive label. Can be prevented. On the other hand, even if the pressure-sensitive label is peeled off unnecessarily by realizing sufficient adhesive strength or the pressure-sensitive label cannot be easily peeled off by a third party, the pressure-sensitive label can be easily removed when necessary. It can be peeled at high speed and at low cost.
[0028]
In particular, by providing the microcapsule layer and the pressure-sensitive adhesive layer and separating the peeling function and the adhesive function, a good balance between the adhesive strength and the easy peeling property can be realized. In addition, since the microcapsule layer is easily manufactured, high productivity of the pressure-sensitive easily peelable label can be realized.
[0029]
Secondly, sufficient adhesive strength and easy peelability can be achieved at the same time, and high-speed peelability that can sufficiently cope with a large number of pressure-sensitive labels can be realized.
[0030]
Therefore, if the pressure-sensitive easy-peeling label of the present invention is used, both sufficient adhesive strength and easy peelability can be achieved, and particularly, high-speed peelability can be realized.
[0031]
In addition, since the principle of peeling of the easily peelable label of the present invention is microcapsule destruction, it is excellent in confidentiality and tamper resistance. Regarding the confidentiality, the label once applied is peeled off by the microcapsule layer and has a structure that cannot be re-applied, so that the recipient can confirm the confidentiality. As for the effect of preventing tampering, the microcapsule layer remains on the adherend, so that the data portion can be protected from tampering and contamination.
[0032]
There is no limitation on the size of the label, and a part, the whole surface, and the whole of the body to be attached can be covered, and an integrated type with a postcard can be manufactured.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0034]
(Micro capsule)
As the microcapsules, inorganic microcapsules and resin microcapsules are used. Inorganic microcapsules refer to microcapsules whose capsule wall is made of an inorganic material such as a glass material and a mineral material. The term “resin-based microcapsule” refers to a microcapsule whose capsule wall is made of a resin material such as a thermosetting resin and a thermoplastic resin. From these microcapsules, an optimum one can be selected according to the intended use, and two or more microcapsules can be used in combination as needed.
[0035]
Further, as the microcapsules, hollow ones or those containing a release agent are used, and the most suitable one is selected according to the application.
[0036]
As the microcapsules having a hollow inside, inorganic microballoons, resin microballoons, and the like are used.
[0037]
As the inorganic microballoons, glass-based microballoons, shirasu-based microballoons, silica-based microballoons, alumina-based microballoons, ceramic-based microballoons, and the like, are used. Systemic microballoons can also be used.
[0038]
Examples of resin microballoons include phenol resin microballoons, epoxy resin microballoons, urea resin microballoons, vinylidene chloride microballoons, styrene resin microballoons, acrylic resin microballoons, and vinyl alcohol resin microballoons. , Silicone resin microballoons, styrene copolymer microballoons, vinylidene chloride-acrylonitrile binary copolymer microballoons, acrylonitrile-methacrylonitrile binary copolymer microballoons, vinylidene chloride-acrylonitrile-divinylbenzene ternary copolymer It is also possible to use a coalescent microballoon or the like, and use a resin-based microballoon surface-treated in order to increase the affinity with the binder.
[0039]
The microcapsules encapsulating the release agent can be formed by chemical encapsulation methods such as interfacial polymerization, in situ polymerization, and liquid curing coating; coacervation, liquid curing coating, liquid drying, and melt dispersion cooling. It can be produced by a physicochemical encapsulation method using a method such as a pan coating method, an air suspension method, or a mechanical encapsulation method using a spray drying method.
[0040]
For example, in the interfacial polymerization method, the raw material of the capsule resin wall exists in both the internal medium of the microcapsule and the external medium of the microcapsule, and the raw material contained in the internal medium of the microcapsule and the external medium of the microcapsule Reacts with the raw materials contained in the resin to form a capsule resin wall.
[0041]
In addition, in the in situ polymerization method, the raw material of the capsule resin wall exists only in one of the internal medium of the microcapsule and the external medium of the microcapsule, and only the raw material contained in the internal medium of the microcapsule reacts. Thus, the capsule resin wall is formed, or only the raw material contained in the external medium of the microcapsule reacts to form the capsule resin wall.
[0042]
The capsule resin wall may be either thermoplastic or thermosetting, and is selected in consideration of the properties of the release agent, the desired microcapsule structure, and the like. Among them, urea resin, melamine resin, polyurethane resin, urethane-urea resin, polyamide resin, polyester resin, polyether resin, polyolefin resin, polysulfonamide resin, polysulfonate resin, etc. Epoxy resins, polycarbonate resins, phenol resins, and the like are preferable, and two or more resins can be used in combination as needed.
[0043]
Specifically, for example, when the capsule resin wall is made of a urea resin, an in situ polymerization method using a methylolated urea compound, an interfacial polymerization method using a urea compound and formaldehyde, a carbonyl halide compound and an amine It can be produced by an interfacial polymerization method using the same.
[0044]
When the capsule resin wall is made of a melamine resin, it can be produced by an in situ polymerization method using a methylolated melamine compound, an interfacial polymerization method using a melamine compound and formaldehyde, or the like.
[0045]
When the capsule resin wall is made of a polyurethane resin, an interfacial polymerization method using an isocyanate compound and a hydroxyl compound, an interfacial polymerization method using a carbonyl monooxy compound and an amine, and an amino-carbonyl monooxy compound are used. It can be produced by the used in situ polymerization method or the like.
[0046]
When the capsule resin wall is made of a urethane-urea resin, it can be manufactured by an interfacial polymerization method using an isocyanate compound and water, an interfacial polymerization method using an isocyanate compound and amines, or the like.
[0047]
When the capsule resin wall is made of a polyamide resin, it can be manufactured by an in situ polymerization method using an amino acid derivative, an interfacial polymerization method using a carboxylic acid derivative and an amine, or the like.
[0048]
When the capsule resin wall is made of a polyester resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0049]
When the capsule resin wall is made of a polyether resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0050]
When the capsule resin wall is made of a polyolefin resin, the capsule resin wall is made by an in situ polymerization method using ethylene, propylene, styrene, (meth) acrylic acid, (meth) acrylate, vinyl acetate, styrene-divinylbenzene, or the like. it can.
[0051]
When the capsule resin wall is made of a polysulfonamide resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and an amine.
[0052]
When the capsule resin wall is made of a polysulfonate resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and a hydroxyl compound.
[0053]
When the capsule resin wall is made of an epoxy resin, it can be manufactured by an interfacial polymerization method using an epoxide and a hydroxyl compound, an interfacial polymerization method using an epoxide and an amine, or the like.
[0054]
When the capsule resin wall is made of a polycarbonate resin, it can be manufactured by an interfacial polymerization method using a hydroxy compound and a carbonyl halide compound.
[0055]
When the capsule resin wall is made of a phenol resin, it can be manufactured by an interfacial polymerization method using an aromatic hydroxy compound and formaldehyde, an interfacial polymerization method using a urea compound and an aromatic hydroxy compound, and the like.
[0056]
In addition, as raw materials of the capsule resin wall, in addition to the above, polyisocyanate, polyisothiocyanate, polyamine, polycarboxylic acid, polybasic acid chloride, acid anhydride, epoxy compound, polyol, (meth) acrylic compound, polysulfide, Organic amines, acid amides, water-soluble epoxy compounds, phenols, formalin, phosgene, spiroacetal heterocyclic amines, aldehydes and the like can also be used.
[0057]
Further, microcapsules mainly composed of a water-soluble resin can be used, and polyvinyl alcohol resins, ethylene-maleic anhydride resins, styrene-maleic anhydride resins, isobutene-maleic anhydride resins, and other olefins can be used. -Use unsaturated carboxylic acid copolymers, polyacrylamide resins, polyethylene oxide resins, polyvinylpyrrolidone resins, vinyl acetate copolymers, acrylic copolymers and the like.
[0058]
In addition, collagen, collagen derivatives, gelatin, albumin, albumin derivatives, casein, polyamino acids such as soy protein; starch, modified starch, acid-modified starch, oxidized starch, acetyl starch, methyl starch, carboxymethyl starch, hydroxyethyl Starches such as starch, aminoalkyl starch, amylose, amylose derivatives, dextrin, British gum; celluloses such as cellulose; cellulose ethers such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose; cellulose nitrate, cellulose acetate, viscose, etc. Cellulose esters of gum arabic, gum tragacanth, gum karaya, locust bean gum, guar gum, konjac bear Nan, alginic acid, or the like is used complex polysaccharides such as funori.
[0059]
These microcapsules having a water-soluble capsule resin wall can be produced by a coacervation method, a liquid curing coating method, a liquid drying method, or the like.
[0060]
The release agent contained in the microcapsule may be one that acts on the binder layer to degrade or destroy the binder, thereby reducing or eliminating the binding ability of the binder, or one that acts on the pressure-sensitive adhesive layer and acts on the pressure-sensitive adhesive layer. Use a material that degrades or destroys the layer, thereby reducing or eliminating the adhesive ability of the pressure-sensitive adhesive layer. When the peeling pressure is applied, the microcapsules are broken, the contained peeling agent leaks, at least one of the binder layer and the pressure-sensitive adhesive layer is deteriorated or broken, and the pressure-sensitive easy-peeling label is peeled. You.
[0061]
The microcapsules described above need to be sufficiently broken when a peeling pressure is applied. Here, the microcapsule is broken when the microcapsule is broken, when the microcapsule is cracked, when the microcapsule is deformed, or when the microcapsule contains the release agent, the release agent leaks. And so on.
[0062]
The pressure resistance of the microcapsule is equal to or higher than the adhesive pressure from the viewpoint of suppressing the destruction of the microcapsule when applying the adhesive pressure to the pressure-sensitive easy-peeling label and bonding the pressure-sensitive easy-peelable label. On the other hand, from the viewpoint of sufficiently breaking the microcapsules when applying the peeling pressure to the pressure-sensitive easy-peeling label and peeling the pressure-sensitive easy-peeling label, the peel pressure is set to the peeling pressure or less.
[0063]
The average particle size of the microcapsules is preferably 1 μm or more, more preferably 10 μm or more, and still more preferably 30 μm or more, from the viewpoint of achieving sufficient releasability. On the other hand, from the viewpoint of the performance balance of the pressure-sensitive easily peelable label, it is preferably 800 μm or less, more preferably 500 μm or less, and still more preferably 300 μm or less.
[0064]
In particular, if microcapsules having an average particle size of 100 μm or more are used, when the peeling pressure is applied to the pressure-sensitive easy-release label and the microcapsules are broken, the contact between the binder layer and the pressure-sensitive adhesive layer is prevented. Because it can be suppressed, good releasability can be realized. From this viewpoint, when the binder layer is formed of a pressure-sensitive adhesive, it is particularly preferable to use microcapsules having a large average particle diameter to suppress the contact between the binder layer and the pressure-sensitive adhesive layer.
[0065]
(Pressure-sensitive adhesive)
Examples of the pressure-sensitive adhesive include natural rubber adhesives, isoprene rubber adhesives, neoprene rubber adhesives, neoprene / phenol resin adhesives, butadiene rubber adhesives, styrene-butadiene rubber adhesives, and acrylonitrile-butadiene. Rubber adhesive, acrylic-butadiene rubber adhesive, chloroprene rubber adhesive, butyl rubber adhesive, urethane rubber adhesive, silicone rubber adhesive, thiochol rubber adhesive, acrylic rubber adhesive, recycled rubber adhesive Rubber-based pressure-sensitive adhesives such as adhesives and isobutylene-based adhesives; acrylic-based pressure-sensitive adhesives; polyvinyl ether-based pressure-sensitive adhesives; silicone-based pressure-sensitive adhesives; polyvinyl acetate-based pressure-sensitive adhesives; Ethylene-based pressure-sensitive adhesive; Uses vinyl chloride-based pressure-sensitive adhesive, among others, from the viewpoint of adhesive strength, rubber-based pressure-sensitive adhesive To use.
[0066]
These pressure-sensitive adhesives include polyterpenes, polyterpene derivatives, temper oil polymers, temper phenol polymers, rosin, glycerin esters of rosin, pentaerythritol-modified rosin, other rosin derivatives, oil-soluble phenolic resins, cumarone indene resins , Petroleum hydrocarbons, petroleum resin, indene resin, ethyl cellulose, α-methylstyrene-vinyltoluene copolymer, etc .; tackifiers; mineral oil, lanolin, liquid polybutene, liquid acrylic resin, dihydroabiethyl phthalate, dihexyl phthalate , Diphenyl phthalate, dimethyl isophthalate, other phthalates, phosphates, ethylene glycol tribenzoate, trimethylolethane tetrabenzoate, other benzoates, salicylates, ben acetate , Fatty acid esters, aliphatic dicarboxylic acid esters, citrate esters, alkylnaphthalenes, alkyldiphenyl ethers, amide compounds, trimellitate esters, arylalkanes, tridichlorohexyl citrate, methoxyethyl stearate -Plasticizers such as urea complexes; fillers such as zinc white, titania, silica, alumina, charcoal, clay, and pigments; aging inhibitors such as antioxidants, ultraviolet absorbers, metal dithiocarbamates, metal chelate bases, etc. Is added as needed.
[0067]
Further, the pressure-sensitive adhesive can be included in the microcapsules in the form of an emulsion. Examples of the emulsion include natural rubber-based latex, isoprene rubber-based latex, butadiene rubber-based latex, styrene-butadiene rubber-based latex, acrylonitrile-butadiene rubber-based latex, acryl-butadiene rubber-based latex, chloroprene rubber-based latex, and butyl rubber-based latex. Urethane rubber-based latex, thiocol rubber-based latex, acrylic rubber-based latex, polyvinyl acetate-based emulsion, vinyl acetate-ethylene-based emulsion, acrylic emuldin, vinyl chloride-based emulsion and the like are used.
[0068]
As the natural rubber-based adhesive, an adhesive grafted with at least one of an acrylic monomer and a styrene-based monomer is preferable from the viewpoint of adhesive strength. Similarly, it is preferable that at least one of the acrylic monomer and the styrene monomer is crosslinked.
[0069]
The acrylic monomer that grafts and crosslinks the natural rubber adhesive is not particularly limited as long as it has sufficient reactivity, but has good compatibility with the natural rubber adhesive and reacts with the double bond of the isoprene skeleton. It is preferable to use those which can be easily treated. From such a viewpoint, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) Octyl acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, lauryl-tridecyl (meth) acrylate, tridecyl (meth) acrylate, Cetyl (meth) acrylate-stearyl, stearyl (meth) acrylate, cyclohexyl (meth) acrylate (Meth) acrylic esters such as syl, benzyl (meth) acrylate and phenyl methacrylate; (meth) acrylic amides such as (meth) acrylic amide and (meth) acrylic methylolamide; (meth) acrylic Acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, butylamino (meth) acrylate Reactive acrylic monomers such as ethyl, glycidyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate; ethylene di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene di (meth) acrylate Glycol, di (meth) a Tetraethylene glycol acrylate, decaethylene glycol di (meth) acrylate, pentadecaethylene glycol di (meth) acrylate, pentacontactor ethylene glycol di (meth) acrylate, butylene di (meth) acrylate, (meth) Crosslinkable acrylic monomers such as allyl acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and diethylene glycol di (meth) acrylate phthalate are used.
[0070]
The styrene monomer for grafting and crosslinking the natural rubber-based adhesive is not particularly limited as long as it has sufficient reactivity. However, the styrene-based monomer has good compatibility with the natural rubber-based adhesive and has a double bond of an isoprene skeleton. And styrene, α-methylstyrene, p-methylstyrene, α-methyl-p-methylstyrene, p-methoxystyrene, o-methoxystyrene, and 2,4-dimethyl. Styrene, chlorostyrene and bromostyrene are used.
[0071]
SBR-based adhesives are also suitably used, for example, emulsion polymerization SBR such as SBR driver and SBR latex; solution polymerization SBR such as random SBR, block SBR and symmetric block SBR.
[0072]
Since the properties of the SBR adhesive greatly depend on the copolymerization ratio of styrene and butadiene, the styrene content is low (30% by mass or less), and the styrene content is moderate (more than 30% by mass and 70% by mass or less). And those having a high styrene content (more than 70% by mass) are carefully selected.
[0073]
In addition, non-modified type, vinylpyridine-modified type, carboxy-modified type, and the like can be used as the SBR-based adhesive. Among them, a carboxy-modified SBR adhesive is preferable from the viewpoint of adhesive strength.
[0074]
In addition to the natural rubber adhesive and the styrene-butadiene adhesive described above, from the viewpoint of adhesive strength, isoprene rubber adhesive, neoprene rubber adhesive, neoprene-phenol resin adhesive, butadiene rubber adhesive Are also preferred.
[0075]
In addition, collagen, collagen derivatives, gelatin, albumin, albumin derivatives, casein, polyamino acid adhesives such as soy protein; starch, modified starch, acid-modified starch, oxidized starch, acetyl starch, methyl starch, carboxymethyl starch, hydroxy Starch adhesives such as ethyl starch, aminoalkyl starch, amylose, amylose derivatives, dextrin, british gum; cellulose adhesives such as cellulose; cellulose ether adhesives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose; cellulose nitrate, cellulose acetate , Viscose and other cellulose ester adhesives; gum arabic, gum tragacanth, gum karaya, locust bean gum, guar Rubber, konjac mannan, alginic acid, and the like complex polysaccharides adhesive such as funori, used from the viewpoint of adhesion.
[0076]
On the other hand, a curable pressure-sensitive adhesive is also preferable, and a curable pressure-sensitive adhesive is a pressure-sensitive adhesive prepared by curing a curable compound by radiation such as ultraviolet rays, electron beams, X-rays, i-rays, and g-rays and heat. Say glue.
[0077]
As the curable compound, from the viewpoint of the performance of the pressure-sensitive adhesive layer, a curable acrylic compound and a cyclic ether-containing curable compound are preferable. If necessary, these compounds can be used in combination.
[0078]
As the curable acrylic compound, an oligomer having at least one or more acryloyl groups or methacryloyl groups is preferable from the viewpoint of achieving good performance of the pressure-sensitive adhesive layer. Further, an oligomer having two or more acryloyl groups or methacryloyl groups is more preferable. Further, an oligomer having a radically reactive unsaturated group in addition to the (meth) acryloyl group can also be used. Examples of such an unsaturated group include an allyl group and a methallyl group.
[0079]
The type of oligomer is not particularly limited, but preferably has a weight average molecular weight of 30 to 1,000, and includes oligoethylene glycol, epoxy resin oligomer, polyester resin oligomer, polyamide resin oligomer, urethane resin oligomer, oligovinyl alcohol, phenol resin oligomer, and the like. Use
[0080]
Further, if necessary, a photopolymerizable monomer can be used as the curable acrylic compound. Preferred photopolymerizable monomers include (meth) acrylic acid, (meth) acrylic acid esters such as alkyl, cycloalkyl, halogenated alkyl, alkoxyalkyl, hydroxyalkyl, aminoalkyl, tetrahydrofurfuryl, allyl, glycidyl, benzyl, Phenoxyacrylates, phenoxymethacrylates, alkylene glycols, mono- or diacrylates and methacrylates of polyoxyalkylene glycols, trimethylolpropane triacrylate and methacrylate, such as pentaerythritol tetraacrylate and methacrylate, acrylamide, methacrylamide or derivatives thereof, such as alkyl groups and Acrylamide and methacrylamide mono- or di-substituted with hydroxyalkyl group, diacetone Acrylamide and methacrylamide, N, can be mentioned N'- alkylene-bis acrylamide and methacrylamide and the like.
[0081]
Further, particularly in the case of an application in which curing shrinkage is an obstacle, for example, isobornyl acrylate or methacrylate, norbornyl acrylate or methacrylate, dicyclopentenoxyethyl acrylate or methacrylate, dicyclopentenoxypropyl acrylate or methacrylate Such as acrylate or methacrylate of diethylene glycol dicyclopentenyl monoether, acrylate or methacrylate of oligooxyethylene or oligopropylene glycol dicyclopentenyl monoether, such as dicyclopentenyl cinnamate, dicyclopentenoxy 3,9-bis (1,1-bismethyl-2-oxo) such as ethyl cinnamate, dicyclopentenoxyethyl monofumarate or difumarate; Ethyl) -spiro [5,5] undecane, 3,9-bis (1,1-bismethyl-2-oxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9- Mono- and diacrylates such as bis (2-oxyethyl) -spiro [5,5] undecane and 3,9-bis (2-oxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane Or mono-, dimethacrylate, or mono-, diacrylate, or mono-, dimethacrylate of ethylene oxide or propylene oxide addition polymer of spiroglycol, or methyl ether, 1-azabicyclo of these monoacrylate or methacrylate. [2,2,2] -3-octenyl acrylate or methacrylate, bicyclo [2,2,1 Such as 5-heptene-2,3-dicarboxyl monoallyl ester, dicyclopentadienyl acrylate or methacrylate, dicyclopentadienyl oxyethyl acrylate or methacrylate, a dihydrodicyclopentadienyl acrylate or methacrylate is used.
[0082]
If necessary, an acrylic monomer, an acrylic oligomer having a polymerization degree of 2 to 10, a mixture thereof, and the like are used. In this case, an oligomer obtained by vinyl polymerization of an acrylic monomer is preferable, and examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. Hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, (meth) acrylic acid (Meth) acrylic such as lauryl-tridecyl, tridecyl (meth) acrylate, cetyl-stearyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate and phenyl methacrylate Acid esters; (meth) acrylamide and (Meth) acrylic amides such as (meth) acrylic acid methylolamide; (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, (meth) Reactive acrylic monomers such as dimethylaminoethyl acrylate, diethylaminoethyl (meth) acrylate, butylaminoethyl (meth) acrylate, glycidyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate; di (meth) ) Ethylene acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, decaethylene glycol di (meth) acrylate, pentadi (meth) acrylate Deca ethyleneg Chole, pentacontaector ethylene glycol di (meth) acrylate, butylene di (meth) acrylate, allyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and di ( Crosslinkable acrylic monomers such as (meth) acrylic acid and diethylene glycol phthalate are preferred. If necessary, two or more of these monomers can be used in combination, and a mixture of oligomers having different degrees of polymerization can also be used.
[0083]
On the other hand, as the cyclic ether-curable compound, the cyclic ether-curable compound is not particularly limited, but from the viewpoint of realizing good performance of the pressure-sensitive adhesive layer, and from the viewpoint of the ring-opening property of the cyclic ether structure. And a cyclic ether-containing curable compound containing at least one cyclic ether structure containing 2 to 12 carbons and 1 to 6 oxygens. Further, the carbon number is more preferably 6 or less, still more preferably 4 or less, and the oxygen number is preferably 4 or less, more preferably 2 or less. Further, the number of the cyclic ether structures is more preferably 2 or more.
[0084]
More specifically, a bridged structure containing -O- is preferable as the cyclic ether structure, and a compound having a group having an epoxy ring such as a glycidyl group is preferable.
[0085]
Further, a compound having a radically reactive unsaturated group in addition to the cyclic ether structure can also be used. Examples of such an unsaturated group include an acryloyl group, a methacryloyl group, an allyl group, and a methallyl group.
[0086]
Further, the group having a cyclic ether structure and the unsaturated group as described above may be bonded to the monomer component and the oligomer component from the viewpoint of realizing good performance of the adhesive composition and the pressure-sensitive adhesive layer. preferable.
[0087]
The type of the oligomer component is not particularly limited, but preferably has a weight average molecular weight of 50 to 1000, and includes oligoethylene glycol, epoxy resin oligomer, polyester resin oligomer, polyamide resin oligomer, urethane resin oligomer, oligovinyl alcohol, and phenol resin oligomer. Use etc.
[0088]
Examples of compounds in which a cyclic ether structure is bonded to these oligomer components include oligoethylene glycol diglycidyl ether.
[0089]
As the type of the monomer component, a monomer of the oligomer component as described above is preferable. As a compound in which a cyclic ether structure is bonded to such a monomer component, for example, ethylene glycol diglycidyl as an example having two glycidyl groups Examples of three ether and glycidyl groups include trimethylolpropane triglycidyl ether.
[0090]
Depending on the type of curable compound used, a polymerization initiator is used in combination. Examples of the polymerization initiator include benzoin, benzoin ethyl ether, benzoin-n-propyl ether, benzoin-isopropyl ether, benzoin alkyl ethers such as benzoin isobutyl-ether, 2,2-dimethoxy-2-phenylacetophenone, benzophenone, Benzyl, diacetyl, diphenyl sulfide, eosin, thionine, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, methylbenzoyl formate and the like can be mentioned. These polymerization initiators may be used alone or in combination of two or more.
[0091]
The pressure-sensitive adhesives described above may be used in combination of two or more as necessary.
[0092]
(binder)
The binder is not particularly limited as long as it can sufficiently hold the microcapsules, but a vinyl alcohol resin, a vinyl ether resin, a vinyl butyral resin, a urethane resin, an ester resin, an epoxy resin, a styrene resin, Acrylic resin, ethylene resin, propylene resin, vinyl acetate resin, vinyl chloride resin, amide resin, vinyl toluene polymer, maleic acid polymer, phenol resin, natural modified phenol resin, natural resin modified maleic resin , Silicone resin, furan resin, xylene resin, terpene resin, coumarone indene resin, petroleum resin; use a copolymer of monomer components of these resins, etc. Can also.
[0093]
Further, water-soluble resins such as polyvinyl alcohol, starch, gelatin, gum arabic, carboxymethylcellulose, hydroxyethylcellulose, and cationized cellulose are also used.
[0094]
Further, a curable resin such as a urethane resin, a silicone resin, a modified silicone resin, a multi-vulcanized rubber, a phenol resin, an epoxy resin, a polyester resin, a melamine resin, and a polyimide resin is also used.
[0095]
On the other hand, a binder layer can also be prepared using a pressure-sensitive adhesive as described above. In particular, when the binder layer is formed with the same pressure-sensitive adhesive as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, the raw material cost can be reduced and the manufacturing process can be simplified.
[0096]
The above binders may be used in combination of two or more as necessary.
[0097]
(Substrate)
As the substrate (support), a sheet-shaped substrate is usually used, and in addition to papers such as ordinary paper and woodfree paper, synthetic films such as synthetic paper, polyethylene, polyethylene terephthalate, polypropylene, and vinyl chloride are used. You can also. When these synthetic films are used, the surface of the base sheet may be subjected to a surface treatment such as a mat treatment and a corona treatment.
[0098]
In addition, a substrate having a multilayer structure can be used if necessary.
[0099]
(Production method)
The binder layer and the pressure-sensitive adhesive layer can be produced, for example, as follows. First, materials necessary for forming a layer are mixed to prepare a raw material. Next, using a blade coater, a rod coater, a knife coater, a roll doctor coater, a reverse roll coater, a transfer roll coater, a gravure coater, a kiss roll coater, a curtain coater, an extrusion coater, and the like, the raw materials are coated and obtained. The applied coating film is dried and cured by reaction to form a layer.
[0100]
In addition, from the viewpoint of the performance balance of the pressure-sensitive easily peelable label, the layer thickness of the binder layer is usually set in a range of 0.5 μm to 1 mm.
[0101]
In addition, from the viewpoint of the performance balance of the pressure-sensitive easily peelable label, the layer thickness of the pressure-sensitive adhesive layer is usually in the range of 0.5 μm to 1 mm.
[0102]
On the other hand, the microcapsule layer is formed by uniformly spraying the microcapsules after forming a coating film to be a binder layer after forming the binder layer or after curing.
[0103]
(Peeling method)
As shown in FIG. 2 (a), peeling rollers 92 and 93 are used as a method for easily, quickly and inexpensively peeling off the pressure-sensitive easily peelable label 90 adhered to the adherend 91 by applying an adhesive force. I do. By using a peeling roller, continuous peeling becomes possible, and in particular, high-speed peeling can be realized. Further, as shown in FIG. 2B, if the pressure-sensitive easily peelable label that has been peeled after passing through the peeling roller is continuously collected by, for example, the suction roller 94, more efficient peeling can be realized.
[0104]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Unless otherwise specified, commercially available high-purity reagents are used.
[0105]
(Example 1) Pressure-sensitive easily peelable label 1
A commercially available acrylic UV-curable pressure-sensitive adhesive prepolymer is applied on a high-quality paper so that the layer thickness after curing becomes 50 μm, and a glass balloon having an average particle diameter of 100 μm is sprayed thereon, and the same acrylic UV is again applied. A curable pressure-sensitive adhesive prepolymer is applied in the same manner, and cured by irradiating UV to produce a pressure-sensitive easily peelable label 1.
[0106]
The pressure-sensitive easy-peeling label 1 can be adhered by hand with an adhesive pressure of about 3 kPa, concealing confidential information, and the pressure-sensitive easy-peeling label 1 can be unnecessarily peeled off or easily peeled off by another person after bonding. Absent. Further, the pressure-sensitive easy-peeling label 1 can be easily peeled at a peeling pressure of 50 kN / m by an inexpensive peeling means having a peeling roller and a suction roller as shown in FIG. it can.
[0107]
In addition, good confidentiality and tamper-proofing properties can be realized.
[0108]
(Example 2) Pressure-sensitive easy release label 2
A commercially available epoxy-based UV-curable pressure-sensitive adhesive prepolymer is applied on a high-quality paper so that the layer thickness after curing becomes 50 μm, and a balloon made of a copolymer of vinylidene chloride and acrylonitrile having an average particle diameter of 100 μm is coated thereon. Then, the same epoxy-based UV-curable pressure-sensitive adhesive prepolymer is applied again in the same manner and cured by irradiating UV to produce a pressure-sensitive easily peelable label 2.
[0109]
The pressure-sensitive easy-peeling label 2 can be adhered to the container with an adhesive roller at an adhesive pressure of 50 N / m, and the pressure-sensitive easy-peeling label 2 is not unnecessarily peeled after the adhesion. Further, the inexpensive peeling means having a peeling roller and a suction roller as shown in FIG. 2 (b) can easily peel the pressure-sensitive easy peeling label 2 at a peeling pressure of 50 kN / m, and particularly, continuously and at high speed. it can.
[0110]
In addition, good confidentiality and tamper-proofing properties can be realized.
[0111]
(Example 3) Pressure-sensitive easily peelable label 3
A commercially available acrylic UV-curable pressure-sensitive adhesive prepolymer is coated on a high-quality paper and UV-cured to form a pressure-sensitive adhesive layer having a thickness of 50 μm, and a glass balloon having an average particle diameter of 100 μm is sprayed thereon, The same acrylic pressure-sensitive adhesive layer is formed again, and the pressure-sensitive peelable label 3 is produced.
[0112]
The pressure-sensitive easily peelable label 3 can be adhered by hand with an adhesive pressure of about 3 kPa to conceal confidential information, and after the adhesion, the pressure-sensitive easily peelable label 3 may be unnecessarily peeled off or easily peeled off by another person. Absent. Further, the pressure-sensitive and easy-to-peel label 3 can be easily peeled at a peeling pressure of 50 kN / m by an inexpensive peeling means having a peeling roller and a suction roller as shown in FIG. it can.
[0113]
In addition, good confidentiality and tamper-proofing properties can be realized.
[0114]
(Example 4) Pressure-sensitive easily peelable label 4
Acrylic monomer-grafted natural rubber-based latex is coated on high-quality paper and dried to form a pressure-sensitive adhesive layer having a thickness of 50 μm, and a glass balloon having an average particle diameter of 100 μm is sprayed on the adhesive layer. A pressure-sensitive peelable label 4 is prepared by forming a monomer-grafted natural rubber-based pressure-sensitive adhesive layer.
[0115]
The pressure-sensitive easily peelable label 4 can be adhered by hand with an adhesive pressure of about 3 kPa to conceal confidential information. Absent. Further, the pressure-sensitive and easy-to-peel label 4 can be easily peeled at a peeling pressure of 50 kN / m by an inexpensive peeling means having a peeling roller and a suction roller as shown in FIG. it can.
[0116]
In addition, good confidentiality and tamper-proofing properties can be realized.
[0117]
(Example 5) Pressure-sensitive easily peelable label 5
To a partially saponified polyvinyl alcohol aqueous solution, a DOA (dioctyl adipate) solution of TPC (terephthalic acid chloride) is added and emulsified. Further, an aqueous solution containing sodium hydroxide, sodium bicarbonate and DETA (diethylenetriamine) is mixed with the obtained emulsion, TPC and DETA are interfacially polymerized, and the resulting HCl is trapped with sodium hydroxide and sodium bicarbonate. The amidation reaction proceeds, and microcapsules having an average particle diameter of 200 μm are collected.
[0118]
Next, SBR latex is coated on a high-quality paper with a flexo coater and dried with hot air to form a pressure-sensitive adhesive layer having a thickness of 80 μm, and the microcapsules are sprayed. A pressure-sensitive adhesive layer having a layer thickness of 80 μm is formed by coating and drying with hot air to produce a pressure-sensitive easily peelable label 5.
[0119]
The pressure-sensitive easy-peeling label 5 can be adhered to the container by an adhesive press with an adhesion pressure of 10 kPa, and the pressure-sensitive easy-peeling label 5 does not unnecessarily peel off after the adhesion. Further, the pressure-sensitive and easy-to-peel label 5 can be easily peeled at a peeling pressure of 50 kN / m by an inexpensive peeling means having a peeling roller and a suction roller as shown in FIG. it can.
[0120]
In addition, good confidentiality and tamper-proofing properties can be realized.
[0121]
【The invention's effect】
For example, as shown in FIG. 1A, a sufficient release label is used in which the microcapsules 12 that are broken by pressure are sandwiched on the base 10 by the binder layer 11 and the pressure-sensitive adhesive layer 13. It achieves both adhesive strength and easy peelability, and particularly achieves high-speed peelability. In addition, good confidentiality and falsification prevention are realized.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view illustrating an example of a pressure-sensitive easy-peeling label.
FIG. 2 is a schematic cross-sectional view for explaining a method of peeling a pressure-sensitive easily peelable label.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Substrate 11 Binder layer 12 Microcapsule 13 Pressure-sensitive adhesive layer 14 Adhesive surface 90 Pressure-sensitive easy-peeling label 91 Applicable body 92 Peeling roller 93 Peeling roller 94 Suction roller

Claims (5)

An easily peelable label in which microcapsules broken by pressure are sandwiched on a substrate by a binder layer and a pressure-sensitive adhesive layer. The easily peelable label according to claim 1, wherein the average particle size of the microcapsules is 1 to 800 µm. 2. The easily peelable label according to claim 1, wherein the binder layer has a pressure-sensitive adhesive property, and the average particle size of the microcapsules is 100 to 800 μm. 4. The easily peelable label according to claim 1, wherein the microcapsules are hollow. The easily peelable label according to any one of claims 1 to 3, wherein the microcapsule contains a release agent.

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