JP2019074561A - Label laminate - Google Patents

Abstract

To provide a label laminate in which curling and the stick-out of an adhesive are suppressed when double-sided printing is performed at high temperature.SOLUTION: A label laminate includes a first adhesive sheet and a second adhesive sheet; the first adhesive sheet has a first adhesive portion and a first peeling portion on its one surface, and a first recording face on the other surface; the second adhesive sheet has a second adhesive portion and a second peeling portion on its one surface, and a second recording face on the other surface; the first adhesive portion and second peeling portion are stacked and the first peeling portion and second adhesive portion are stacked; shear stress is 12 N/25 mm or more when the first adhesive sheet and second adhesive sheet are pulled in directions parallel to the sheet surface and opposite to each other under an environment of 80°C; and the shear storage elastic modulus measured at a frequency of 1 Hz under the environment of 80°C of the adhesive constituting the first adhesive portion and second adhesive portion is 6000 Pa or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a label laminate.

A label laminate having a recording layer on both sides and capable of printing on both sides is known. As a specific configuration of a label laminate, conventionally, there is known a bonding type double-sided label in which two sets of pressure-sensitive adhesive sheets are attached to each other with adhesive portions facing each other so as to be peelable (see Patent Document 1).
In Patent Document 1, a first label sheet portion in which a mold release agent coated portion and a mold release agent non-coated portion of a pattern are alternately provided on one side and a first label sheet portion, respectively, as appropriate. A second label formed by providing the release agent coated portion and the release agent non-coated portion in the same pattern with the release agent coated portion and the release agent non-coated portion respectively on one side. Between the sheet portion and the release agent coated portion in the first label sheet portion and the release agent non-coated portion in the second label sheet portion, and the release agent uncoated in the first label sheet portion A first label sheet portion and a second label sheet portion with an adhesive layer formed between each of the first and second label sheet portions, and the adhesive layer formed between the first and second label sheet portions; And a laminated double-sided label is described.

On the other hand, in a technical field other than a double-sided printable label laminate, a pressure-sensitive adhesive sheet is provided, in which a release layer is provided on one side and an adhesive part is provided on part of the other side. It is known to make it (refer patent document 2).
Patent Document 2 has a substrate, an adhesive portion provided on one surface of the substrate, and a release layer provided on the other surface of the substrate, and the adhesive portion is made of the substrate. A plurality of pressure sensitive adhesive sheets formed intermittently on the surface are described.

Japanese Utility Model Application Publication No. 3-75470 JP, 2014-153540, A

In recent years, in order to realize double-sided printing at high speed, high-temperature double-sided printing with an electrophotographic printer has been required.
When the present inventors produced a double-sided printable label laminate described in Patent Document 1 and performed high-temperature double-sided printing at high speed with a printer that is an electrophotographic printing machine, problems such as paper jams and printing defects occurred. It was found to occur. In particular, when printing the second recording surface without leaving time after printing the first recording surface of the label laminate, curling of the label laminate after double-sided printing occurs largely, It has been found that image stains that are believed to be caused by the sticking out adhesive occur inside the printer.

  In addition to the adhesive force after time-lapse | temporality at the time of sticking an adhesive sheet to an adherend being fully obtained to patent document 2, in lamination type adhesive sheet, lightening peeling of each laminated adhesive sheet is carried out. Is described as being able to In patent document 2, after making it into a lamination type adhesive sheet, there was no suggestion of printing further, and there was also no suggestion of the characteristic of the adhesion part and the exfoliation layer in the case of using a lamination type pressure sensitive adhesive sheet for printing at high temperature.

  The problem to be solved by the present invention is to provide a label laminate in which curling and sticking out of the adhesive are suppressed when printing on both sides at high temperature.

  The present inventors diligently studied to solve the above-mentioned problems. As a result, when printing the second recording surface without time after the printing of the first recording surface at high temperature, the pressure-sensitive adhesive in the adhesive portion is softened by heating during the first recording surface printing or It was found that the curing causes a change in the rigidity and / or elongation of the pressure-sensitive adhesive sheet constituting the label laminate, a large occurrence of curling, and a protrusion of the pressure-sensitive adhesive.

  The present inventors set shear stress measured in an 80 ° C. environment to a specific range or more, and set shear storage elastic modulus measured at a frequency of 1 Hz in an 80 ° C. environment of an adhesive to a specific range or more. Thus, the present inventors have found that it is possible to provide a label laminate in which curling and sticking out of a pressure-sensitive adhesive can be suppressed when duplex printing is performed at high temperature, and the present invention has been completed.

The present invention and preferred embodiments of the present invention are as follows.
[1] A label laminate having a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet;
The first adhesive sheet has a first adhesive part and a first peeling part on one side, and has a first recording surface on the other side;
The second adhesive sheet has a second adhesive part and a second peeling part on one side, and has a second recording surface on the other side;
A first adhesive part and a second peeling part are laminated, and a first peeling part and a second adhesive part are laminated;
The shear stress is 12 N / 25 mm or more when pulling the first adhesive sheet and the second adhesive sheet parallel to the sheet surface in the opposite direction in an 80 ° C. environment;
The label laminated body whose shear storage elastic modulus measured by frequency 1 Hz in the 80 degreeC environment of the adhesive which comprises a 1st adhesion part and a 2nd adhesion part is 6000 Pa or more.
[2] The first adhesive portion is located in the plane of the second peeling portion,
The label laminated body as described in [1] in which the 2nd adhesion part is located in the surface of a 1st peeling part.
[3] The label laminate according to [1] or [2], wherein the first adhesive portion and the second adhesive portion are each plural.
[4] The label laminate according to any one of [1] to [3], wherein the first adhesive part and the second adhesive part are in the form of a plurality of stripes.
[5] The label laminate according to [4], wherein the first peeling portion and the second peeling portion are in the form of a plurality of stripes.
[6] The label laminate according to any one of [1] to [5], wherein the first adhesive part and the second adhesive part are composed of a hot melt adhesive.
[7] The first adhesive sheet has a first base material that doubles as a first recording surface,
The label laminated body as described in any one of [1]-[6] which has a 2nd base material which a 2nd adhesive sheet doubles as a 2nd recording surface.

  According to the present invention, it is possible to provide a label laminate in which curling and sticking out of the adhesive are suppressed when duplex printing is performed at high temperature.

FIG. 1 is a schematic view showing a cross section of an example of a label laminate of the present invention. FIG. 2 is a schematic view showing a cross section of an example of a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet. FIG. 3 is a schematic view of an example of the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet as viewed from the side on which the pressure-sensitive adhesive portion and the peeling portion are formed. FIG. 4 is a schematic view illustrating a method of measuring shear stress in an 80 ° C. environment. FIG. 5A and FIG. 5B are schematic diagrams illustrating the method of measuring the curl amount.

  Hereinafter, the present invention will be described in detail. The description of the configuration requirements described below may be made based on typical embodiments and specific examples, but the present invention is not limited to such embodiments. In addition, the numerical range represented using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

[Label stack]
The label laminate of the present invention is a label laminate having a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet;
The first adhesive sheet has a first adhesive part and a first peeling part on one side, and has a first recording surface on the other side;
The second adhesive sheet has a second adhesive part and a second peeling part on one side, and has a second recording surface on the other side;
A first adhesive part and a second peeling part are laminated, and a first peeling part and a second adhesive part are laminated;
The shear stress is 12 N / 25 mm or more when pulling the first adhesive sheet and the second adhesive sheet parallel to the sheet surface in the opposite direction in an 80 ° C. environment;
The shear storage modulus measured at a frequency of 1 Hz under an environment of 80 ° C. of the pressure-sensitive adhesive forming the first pressure-sensitive adhesive portion and the second pressure-sensitive adhesive portion is 6000 Pa or more.

With this configuration, the label laminate of the present invention suppresses curling and sticking of the adhesive when double-sided printing is performed at high temperature.
When the shear stress measured in the 80 ° C. environment of the label laminate is equal to or greater than the specific range, the pressure-sensitive adhesive sheet is caused by softening or curing of the pressure-sensitive adhesive in the adhesion part by heating during the first recording surface printing Changes in stiffness and / or elongation can be suppressed, and curling and adhesive sticking out can be suppressed in the paper passage path of the printer.
When the shear storage modulus measured at a frequency of 1 Hz in the 80 ° C. environment of the pressure sensitive adhesive is equal to or greater than the specific range, it is caused by the softening or curing of the pressure sensitive adhesive at the adhesive portion by heating during the first recording surface printing. It is possible to suppress the change in the rigidity and / or the elongation of the pressure-sensitive adhesive sheet, and to suppress the curl and the protrusion of the pressure-sensitive adhesive in the sheet passing path of the printer.
Hereinafter, the preferable aspect of the label laminated body of this invention is demonstrated.

<Shear stress of label laminate>
The label laminate of the present invention has a shear stress of 12 N / 25 mm or more when the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet are pulled parallel to the sheet surface and in opposite directions in an 80 ° C. environment.
The shear stress when pulling the first adhesive sheet and the second adhesive sheet parallel to the sheet surface in the opposite direction in an 80 ° C. environment is preferably 14 N / 25 mm or more, and 16 N / 25 mm or more Is more preferred.
The shear stress in the case of pulling the first adhesive sheet and the second adhesive sheet parallel to the sheet surface in the opposite direction in an 80 ° C. environment is not limited to the upper limit value, and can be, for example, 30 N / 25 mm or less .

<Configuration of Label Laminate>
The configuration of the label laminate of the present invention will be described using the drawings.
FIG. 1 is a schematic view showing a cross section of an example of a label laminate of the present invention. FIG. 2 is a schematic view showing a cross section of an example of a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet.
The label laminate 30 shown in FIG. 1 has a first pressure-sensitive adhesive sheet 10 and a second pressure-sensitive adhesive sheet 20.
Although the first adhesive sheet 10 is omitted in FIG. 1, as shown in FIG. 2, it has the first adhesive portion 11 and the first peeling portion 12 on one side, and the first side on the other side. The recording surface 14 of Furthermore, the first pressure-sensitive adhesive sheet 10 preferably has a first base 13.
Although the second adhesive sheet 20 is omitted in FIG. 1, as shown in FIG. 2, the second adhesive sheet 21 and the second peeling part 22 are provided on one side, and the second side is provided on the other side. The recording surface 24 of Furthermore, the second pressure-sensitive adhesive sheet 20 preferably has a second base material 23.
In the label laminate 30, the first adhesive portion 11 and the second peeling portion 22 are laminated, and the first peeling portion 12 and the second adhesive portion 21 are laminated. According to this configuration, the first pressure-sensitive adhesive sheet 10 and the second pressure-sensitive adhesive sheet 20 are bonded to each other, and the first pressure-sensitive adhesive sheet 10 of the label laminate and the second pressure-sensitive adhesive after double-sided printing at high temperature The sheets 20 can be peeled off from one another.

  In the following description, “pressure-sensitive adhesive sheet” is a description common to the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet. In the case of describing as “adhesive portion”, the description is common to the first adhesive portion and the second adhesive portion. In the case of describing as “peeling part”, the description is common to the first peeling part and the second peeling part. The case of describing as “recording surface” is a description common to the first recording surface and the second recording surface. When described as "substrate", the description is common to the first substrate and the second substrate.

Regarding the relationship between the first adhesive unit 11, the first peeling unit 12, the second peeling unit 22, and the second adhesive unit 21, the first adhesive unit 11 and the second peeling unit 22 are stacked, and If the 1st exfoliation part 12 and the 2nd adhesion part 21 are laminated, there will be no restriction in particular. The first adhesive portion 11, the first peeling portion 12, the second peeling portion 22 and the second adhesive portion 21 can be formed in an arbitrary pattern, respectively.
Among them, in the present invention, it is preferable that the first adhesive portion 11 be positioned in the plane of the second peeling portion 22 and the second adhesive portion 21 be positioned in the plane of the first peeling portion 12. That is, it is preferable that the first adhesive portion 11 be included in the surface of the second peeling portion 22 and not protrude from the second peeling portion 22. The second adhesive portion 21 is preferably included in the surface of the first peeling portion 12 and does not protrude from the first peeling portion 12.

In the present invention, it is preferable from the viewpoint of easily increasing the shear stress measured in an 80 ° C. environment that each of the first adhesive part and the second adhesive part is plural.
The number of the first adhesive portion and the second adhesive portion is preferably 3 or more, more preferably 3 to 100, and particularly preferably 3 to 30.
It is preferable from the viewpoint of making it correspond to the number of the 2nd adhesion part and the number of the 1st adhesion parts that each of the 1st exfoliation part and the 2nd exfoliation part is also plural.
It is preferable that the first peeling portion and the second peeling portion have the same number or more as the second adhesive portion and the first adhesive portion, respectively. From the viewpoint of providing a glue margin (ear portion) that the first peeling portion and the second peeling portion each have one or more (more by one or more lines depending on the pattern shape) than the second adhesive portion and the first adhesive portion, respectively More preferred.
When there are a plurality of first adhesive parts and second adhesive parts, it is preferable that two or more first adhesive parts are not adjacent to each other, and two or more second adhesive parts are adjacent to each other Preferably not. According to this configuration, while maintaining the adhesiveness when double-sided printing is performed at high temperature of the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet, the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet after double-sided printing at high temperature Peeling can be lightened.

Preferably, the first adhesive portion and the second adhesive portion are arranged in a regular predetermined pattern. Similarly, it is preferable that the first peeling portion and the second peeling portion be arranged in a regular predetermined pattern.
As a pattern of a 1st adhesion part and a 2nd adhesion part, dot pattern shape, stripe shape, etc. can be mentioned, It is preferable that it is stripe shape.

When the first adhesive portion and the second adhesive portion have a dot pattern, it is preferable that the first adhesive portion and the second adhesive portion have a uniform dot pattern.
The dots forming the dot pattern can be dots of a desired shape.
Dots of a desired shape may be substantially circular, ginkgo-shaped, star-shaped, polygon-shaped, picture-patterned, spiral-shaped, wavy, zigzag-shaped, or stripe-shaped.
The adhesive part provided discontinuously may be in a slightly expanded state by pressing when it is attached to the peeling part. In this case, even if the adhesive portion is a dot having a desired shape such as a substantially circular shape, even if it is spread out, thickness unevenness is difficult to occur, and adhesion with the peeling portion can be made favorable.
When the shape of the adhesive portion is a dot pattern, the shapes described in [0021] to [0022] and [Fig. 2] to [Fig. 6] of JP-A-2014-153540 are preferable, and the contents of this publication are referred to Are incorporated herein.

When the first adhesive portion and the second adhesive portion are in the form of stripes, in the present invention, it is measured under an environment of 80 ° C. that the first adhesive portions and the second adhesive portions are in the form of stripes. It is preferable from the viewpoint of easily increasing the shear stress.
FIG. 3 is a schematic view of an example of the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet as viewed from the side on which the pressure-sensitive adhesive portion and the peeling portion are formed. FIG. 3 shows a view of the first pressure-sensitive adhesive sheet 10 and the second pressure-sensitive adhesive sheet 20 shown in FIG. 2 as viewed from the pressure-sensitive adhesive portion side.

In the present invention, it is preferable that the first peeling portion and the second peeling portion have a plurality of stripes.
The stripe width of the first adhesive portion is preferably the same as the stripe width of the second peeled portion or narrower than the stripe width of the second peeled portion. In the present invention, the stripe width of the first adhesive portion is more preferably narrower than the stripe width of the second peeled portion. The stripe width of the first adhesive portion is preferably 0.1 to 20 mm, more preferably 1 to 10 mm, and particularly preferably 2 to 5 mm.
The stripe width of the second adhesive portion is preferably the same as the stripe width of the first peeled portion or narrower than the stripe width of the first peeled portion. In the present invention, the stripe width of the second adhesive portion is preferably narrower than the stripe width of the first peeled portion. The stripe width of the second adhesive portion is preferably 0.1 to 20 mm, more preferably 1 to 10 mm, and particularly preferably 2 to 5 mm.
When the stripe width of the first adhesive portion is narrower than the stripe width of the second peeling portion, the stripe width of the first adhesive portion is 70% or more and 99% or less of the stripe width of the second peeling portion Is preferred.
When the stripe width of the first adhesive portion is 70% or more of the stripe width of the second peeling portion, the adhesive strength of the adhesive sheet to the adherend can be further enhanced.
When the stripe width of the first adhesive portion is 99% or less of the stripe width of the second peeling portion, the pressure-sensitive adhesives in the first adhesive portion and the second adhesive portion avoid contact with each other, and the first adhesive The pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet can be easily peeled off.

In the label laminate, one adhesive sheet may be provided with a turning margin.
The label laminate may be a sheet roll which is wound and formed in a roll. In addition, the label laminate may be cut into a sheet shape.
The first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet of the label laminate may be partially completely bonded to each other so that they may not completely peel off, and may be completely peeled off without providing a portion completely bonded to each other. May be

<Adhesive sheet>
In the present invention, the first pressure-sensitive adhesive sheet has a first pressure-sensitive adhesive portion and a first peeling portion on one side and a first recording surface on the other side;
The second pressure-sensitive adhesive sheet has a second pressure-sensitive adhesive portion and a second peeling portion on one side, and has a second recording surface on the other side.
The preferable aspect of each part which comprises an adhesive sheet is demonstrated.

(Base material)
The pressure-sensitive adhesive sheet preferably has a substrate.
As the substrate used in the present invention, materials having flatness such as paper, cloth, cellophane, plastic film, metal plate, wood plate, glass plate and the like can be used, and among them, paper is preferably used. The pulp constituting the paper base used in the present invention can be adjusted in the degree of beating by a beating machine in order to adjust the paper strength and papermaking suitability. The degree of beating of the pulp is not particularly limited, but in general, it is preferably about 250 to 550 ml (CSF; JIS P-8121).

  Pulp fibers are aggregates of cellulose fibers removed from wood and other plants by mechanical or chemical treatment. As pulp fibers, those generally used for paper raw materials such as high-quality paper and paperboard can be used. For example, each fiber such as recycled paper pulp, chemical pulp, mechanical pulp and the like can be mentioned.

  The waste paper pulp is, for example, disintegrated waste paper pulp manufactured from waste cardboard, tea waste, kraft envelope waste paper, magazine waste paper, newspaper waste paper, flyer waste paper, office waste paper, white waste paper, Kent waste paper, imitation waste paper, ground paper waste paper, etc. And deinked and deinked waste paper pulp and deinked and bleached waste paper pulp.

  As chemical pulp, for example, hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached kraft pulp (NUKP), hardwood semi-bleached kraft pulp (LSBKP), softwood Semi-bleached kraft pulp (NSBKP), hardwood sulfite pulp, softwood sulfite pulp and the like can be mentioned.

  As mechanical pulp, for example, stone ground pulp (SGP), pressed stone ground pulp (PGW), refiner ground pulp (RGP), chemi ground pulp (CGP), thermo ground pulp (TGP), ground pulp (GP), thermo Mechanical pulp (TMP), chemithermomechanical pulp (CTMP), refiner mechanical pulp (RMP), etc. may be mentioned.

  Among these pulp fibers, chemical pulp is preferred from the viewpoint of being able to impart excellent strength, dimensional stability and processability to the obtained base material together, and hardwood bleached kraft pulp (LBKP) is particularly preferably used.

In order to impart writability and sealability to the surface of the substrate, it is preferable to incorporate a pigment into the substrate. Examples of the pigment include light calcium carbonate, calcined kaolin, white carbon, talc, titanium oxide and the like. Among them, talc, light calcium carbonate and white carbon are preferably used.
When the pigment is blended in the substrate, the content of the pigment to the substrate is preferably 0.1 to 30% by mass, and more preferably 1 to 20% by mass. By setting the pigment content in the above range, the writing property and the marking property can be improved. Moreover, sufficient paper strength can also be obtained by making the content rate of a pigment below the said upper limit.

  As the auxiliary agent, for example, internal sizing agents (higher fatty acids, alkyl ketene dimers, etc.), fixing agents (sulfate bands, cationic polymer electrolytes, etc.), paper strength agents (starch, polyacrylamide, polyvinyl alcohol, etc.), There may be mentioned cationizing agents, retention aids, dyes, fluorescent whitening agents, mildewproofing agents and the like.

In addition, the base material may be subjected to a sizing treatment with a size press or a gate roll for the purpose of adjusting surface strength, sizeability and the like.
Examples of the size treatment liquid used for the size treatment include treatment liquids in which starches, polyvinyl alcohols, polyacrylamides, surface sizing agents, cationic resins and the like are mixed with a solvent. As a surface sizing agent, for example, styrene-maleic acid copolymer, olefin copolymer, alkyl ketene dimer compound, alkenyl succinic anhydride compound, styrene-acrylic copolymer, higher fatty acid compound, petroleum resin Examples include sizing agents, rosin sizing agents and the like.
The coating amount of the sizing solution is the dry mass is preferably 0.3 to 5.0 g / m ^2, and more preferably 0.5 to 3.0 g / m ^2. When the coating amount is equal to or more than the above lower limit value, the effect of the size treatment is easily obtained. Further, when the coating amount exceeds the above upper limit value, the effect of the size treatment is overrun, and therefore, the above upper limit value is also advantageous in cost. When the size treatment is performed on both sides, the coating amount of the size treatment liquid is preferably within the above range in total on both sides.

Preferably weighing the substrate is 40~210g / m ^2, and more preferably 60~120g / m ^2. By making the weighing more than the above lower limit value, it is easy to obtain sufficient paper strength. In addition, the paper thickness can be reduced by setting the weighing to the upper limit value or less.
The density of the paper substrate is preferably 0.55 to 1.00 g / cm ³ . By setting the density within the above range, it is possible to have sufficient paper strength and to improve the writing property and the marking property.

The substrate is preferably an uncoated paper or a single-sided coated paper provided with a coating layer on one side. When the substrate is coated on one side, good writability and sealability can be obtained. In this case, the substrate preferably has a coated layer on the side opposite to the writing and marking side.
As uncoated paper, for example, high quality paper, medium quality paper, single-glossy paper, etc. may be mentioned. In addition, general printing paper or thermosensitive recording paper may be used as single-sided coated paper.

(Recording side)
There is no particular limitation on the recording surface. When the substrate is a recordable substrate such as a paper substrate, it is preferable to use the surface of the substrate as the recording surface.
In the present invention, it is preferable that the first adhesive sheet has a first base that doubles as a first recording surface, and the second adhesive sheet has a second base that doubles as a second recording surface.
A colored picture or character pattern may be formed on the surface on the side where the adhesive portion and the peeling portion are formed opposite to the recording surface. By forming a colored pattern or the like on the side on which the adhesive part and the peeling part are formed, the adhesive sheet of the label laminate can be peeled off and then the interest and interest of an infant etc. can be gained. It can be preferably used as a label for a toy for toddlers or a teaching material for toddlers.
In addition, by forming a picture, a character pattern, etc. colored by double-sided printing on the recording surface of the label laminate, it is possible to gain the interest and interest of an infant etc. before peeling off the adhesive sheet of the label laminate. .

(Adhesive part)
Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive portion include solvent pressure-sensitive adhesives, emulsion pressure-sensitive adhesives, and hot melt pressure-sensitive adhesives. Among them, a hot-melt pressure-sensitive adhesive is preferably used from the viewpoint that the pressure-sensitive adhesive does not easily penetrate into the base material and the pattern coating suitability is high. That is, in the present invention, it is preferable that the first adhesive portion and the second adhesive portion be made of a hot melt adhesive. In addition, since a hot melt adhesive shows strong viscosity, it can suppress that an adhesion part peels from a peeling part.
The hot melt pressure-sensitive adhesive refers to a pressure-sensitive adhesive that turns from a rubber-like flat area to a flow area when heated to 80 ° C. or higher.

  As the pressure-sensitive adhesive used in the present invention, a pressure-sensitive adhesive generally called strong viscosity is preferably used. When a pressure-sensitive adhesive such as a medium-viscosity or weak-viscosity adhesive other than a strong viscosity is used, a problem may occur such as a pressure-sensitive adhesive sheet attached being dropped during transportation. A highly viscous pressure-sensitive adhesive is a pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive portion uniformly on the entire surface, which has a 180 ° peel strength at 23 ° C. and 50% relative humidity environment measured based on JIS Z 0237 of the pressure-sensitive portion. It is 3N / 10 mm or more. The 180 ° peel adhesive strength in this case is more preferably 5 N / 10 mm or more, and further preferably 7 N / 10 mm or more.

-Polymer-
The hot melt pressure-sensitive adhesive preferably contains a polymer.
Examples of the polymer used in the present invention include thermoplastic polymers such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, styrene polymer, acrylic polymer and the like. Among them, it is preferable to use a thermoplastic polymer such as a styrene-based polymer or an acrylic polymer from the viewpoint of stability of adhesive strength, bleeding and cost, and it is more preferable to use a styrene-based polymer.

Examples of styrene-based polymers include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene -Ethylene-propylene-styrene block copolymer (SEPS) etc. are mentioned. Among these, SIS is preferable.
As the SIS, a first SIS whose styrene component is at most 20% by mass (preferably 5 to 15% by mass) and a second SIS whose styrene component exceeds 20% by mass (preferably 25 to 50% by mass) It is preferable to use in combination. The first SIS is preferably 5 to 30% by mass, more preferably 10 to 20% by mass, and particularly preferably 15 to 19% by mass with respect to the total mass of the hot melt pressure-sensitive adhesive . The second SIS is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, particularly preferably 15 to 25% by mass, based on the total mass of the hot melt pressure-sensitive adhesive .

  As an acrylic polymer, the glass transition temperature is 110 ° C. or more at both ends of a (meth) acrylic acid alkyl ester polymer block having a glass transition temperature of 30 ° C. or less described in JP-A No. 11-323072 and syndiotactic Block copolymer composition comprising a triblock copolymer in which a methacrylic acid alkyl ester polymer block having a weight of 70% or more is bonded and a (meth) acrylic acid alkyl ester diblock copolymer, Containing a specific diblock copolymer comprising a methacrylic acid alkyl ester polymer block and an acrylic acid alkyl ester polymer block described in JP-A-2004-2736 and a (meth) acrylic acid ester triblock copolymer Pressure-sensitive adhesive composition, as described in JP-A No. 2005-307063 Adhesion containing (meth) acrylic acid ester triblock copolymer and (meth) acrylic acid ester diblock copolymer having a molecular weight of 120,000 or more and a molecular weight distribution (Mw / Mn) of less than 1.5 Although an agent composition etc. are mentioned, it does not specifically limit.

The polymers may be used alone or in combination of two or more.
As the polymer, a combination of a first polymer having a weight average molecular weight of 1 to 100,000 (preferably 3 to 70,000) and a second polymer having a weight average molecular weight of greater than 100,000 (preferably 30 to 150,000) It is preferable to do.
The molecular weight distribution (Mw / Mn) of the polymer is preferably less than 1.5, and more preferably 1.2 or less.
The molecular weight of the polymer is a value determined by size exclusion chromatography (SEC) and determined based on polystyrene. As a polymer, a commercially available thing may be used and what was synthesize | combined by the well-known method may be used.

-Tackifier-
A tackifier may be blended with the pressure-sensitive adhesive forming the pressure-sensitive adhesive portion for the purpose of improving the pressure-sensitive adhesiveness.
The tackifier includes, for example, rosin, ester gum, ester gum H, polyterpene resin, C5 petroleum resin, C9 petroleum resin, DCPD petroleum resin, styrene resin, alkylphenol resin, terpene phenol resin, and water thereof An additive etc. are mentioned. Among them, polyterpene resin, hydrogenated substance of C5 petroleum resin and hydrogenated substance of C9 petroleum resin are preferably used. Among these, rosin is preferred.
A commercial item may be used as a tackifier. For example, "ester gum 105" manufactured by Arakawa Chemical Co., Ltd., which is a rosin ester, can be mentioned.
The tackifier is preferably 5 to 60% by mass, more preferably 20 to 50% by mass, and particularly preferably 30 to 45% by mass, based on the total mass of the hot melt pressure-sensitive adhesive.

-Softener-
A softener may be blended with the pressure-sensitive adhesive forming the pressure-sensitive adhesive portion in consideration of device compatibility.
Examples of the softening agent include various plasticizers, polybutene, liquid tackifier resin, polyisobutylene low polymer, polyvinyl isobutyl ether low polymer, lanolin, depolymerized rubber, process oil, naphthenic oil, paraffin oil, Sulfurized oil etc. are mentioned. Among these, paraffinic oils are preferred.
A commercial item may be used as a softener. For example, "Shellflex 371N" manufactured by US Shell Chemical Company, which is a paraffinic oil, can be mentioned.
The softening agent is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and particularly preferably 15 to 25% by mass with respect to the total mass of the hot melt pressure-sensitive adhesive.

-Antioxidant-
An antioxidant may be blended in the pressure-sensitive adhesive forming the pressure-sensitive adhesive portion.
Examples of the antioxidant include phenol based antioxidants, amine based antioxidants, lactone based antioxidants, phosphorus based antioxidants, sulfur based antioxidants and the like. Among these, phenolic antioxidants are preferred.
A commercial item may be used as an antioxidant. For example, "Sumilyzer GM" manufactured by Sumitomo Chemical Co., Ltd., which is a phenolic antioxidant, can be mentioned.
It is preferable that it is 0.1-5 mass% with respect to the total mass of a hot-melt adhesive, and, as for antioxidant, it is more preferable that it is 0.5-2 mass%.

-Shear storage modulus of adhesive-
In the present invention, the shear storage elastic modulus measured at a frequency of 1 Hz under an environment of 80 ° C. of the adhesive constituting the first adhesive part and the second adhesive part is 6000 Pa or more.
The shear storage modulus measured at a frequency of 1 Hz in an 80 ° C. environment of the pressure-sensitive adhesive constituting the adhesive portion is preferably 7000 Pa or more, and more preferably 7500 Pa or more.
The shear storage modulus measured at a frequency of 1 Hz in an 80 ° C. environment of the pressure-sensitive adhesive constituting the adhesive portion is not limited to the upper limit value, and can be, for example, 30000 Pa or less.

  It is preferable that the ratio of the area which an adhesion part occupies with respect to the area of the surface of a base material is 20 to 50%. The ratio of the area occupied by the adhesive portion is more preferably 30% or more, and still more preferably 40% or more. The ratio of the area occupied by the adhesive portion is preferably less than 50%, more preferably 49% or less, and still more preferably 48% or less.

(Peeling part)
There is no restriction | limiting in particular as a release agent which forms a peeling part, A silicone type release agent can be used preferably. As a silicone type release agent, for example, a thermosetting type release agent (addition reaction type silicone type release agent, condensation reaction type silicone type release agent, etc.), an electron beam curing type silicone type release agent, an ultraviolet curing type silicone type release agent ( Radical polymerization silicone release agents, cationic polymerization silicone release agents, mercapto-vinyl addition polymerization silicone release agents, etc. may be mentioned. Among them, an electron beam-curable silicone-based release agent or an ultraviolet-curable silicone-based release agent is preferably used because the curing speed is high and it is difficult to penetrate the paper substrate. In addition, these release agents also have the advantage of reducing the peeling between the pressure-sensitive adhesive sheets when forming a label laminate. Further, from the viewpoint of reducing equipment investment, ultraviolet curing silicone type release agents or cationic polymerization type silicone type release agents are also preferably used.
A commercial item may be used as a release agent. For example, polysilicone "Siliconis POLY 201" manufactured by Rhodia, Inc. can be mentioned.

As the release agent, if necessary, other ultraviolet curing resin, electron beam curing resin, photopolymerization initiator, crosslinking agent, dye, pigment, wetting agent, antifoaming agent, dispersing agent, antistatic agent, leveling agent, You may mix | blend various adjuvants, such as a lubricant.
A commercial item may be used as a photoinitiator. For example, "silicone CATA 211" manufactured by Rhodia, which is an onium salt-based photopolymerization initiator can be mentioned.

  From the viewpoint of reducing peeling of the pressure-sensitive adhesive sheet, the smoothness of the surface of the peeling portion is preferably 10 seconds or more, and more preferably 30 seconds or more. In addition, smoothness can be calculated | required according to "the Oken type smoothness based on" JAPAN TAPPI paper pulp test method No.5-2. "

  It is preferable that the ratio of the area which a peeling part occupies with respect to the area of the surface of a base material is 50 to 80%. As for the ratio of the area which a peeling part occupies, it is more preferable that it is 51% or more, and it is especially preferable that it is 52% or more. Further, the ratio of the area occupied by the peeling portion is preferably 70% or less, and more preferably 60% or less.

(Other composition of adhesive sheet)
The adhesive sheet may have other configurations.
As shown in FIG. 5A of JP-A-2014-153540, the pressure-sensitive adhesive sheet may have a non-adhesive portion having a certain area or more. The non-adhesive portion is not coated with the adhesive. For this reason, it is not necessary to apply a release agent to the part which is a exfoliation part on the opposite side of a substrate, and which a non-adhesive part overlaps, when laminating a pressure sensitive adhesive sheet. That is, in the base material, a non-laminated portion where the release agent is not laminated can be provided in the region corresponding to the non-adhesive portion. In the non-laminated portion, the substrate is exposed. The shape of the non-adhesive portion and the non-laminated portion can be various shapes such as a circle, an oval, a square, a triangle and the like. Preferably, the non-adhesive portion and the non-laminated portion have the same shape so as to overlap when laminated.

<Method of manufacturing label laminate>
There is no restriction | limiting in particular as a manufacturing method of a label laminated body.
It is preferable that the manufacturing method of a label laminated body includes the formation process of the label laminated body which bonds a 1st adhesive sheet and a 2nd adhesive sheet together.
The step of forming the label laminate preferably includes a step of producing a first pressure-sensitive adhesive sheet and a step of producing a second pressure-sensitive adhesive sheet.
It is preferable that the process of manufacturing a 1st adhesive sheet and the process of manufacturing a 2nd adhesive sheet include the formation process of a peeling part, and the formation process of an adhesion part. Furthermore, the step of producing the first pressure-sensitive adhesive sheet and the step of producing the second pressure-sensitive adhesive sheet may include a step of producing a substrate.

(Production of base material)
There is no restriction | limiting in particular as a manufacturing process of a base material.
When a paper substrate is used as the substrate, the paper substrate is obtained by paper making using a known paper machine such as a Fourdrinier paper machine, a cylinder paper machine, Yankee paper machine, twin wire former, inclined wire former, etc. be able to. The paper substrate may be subjected to known processing such as calendering.

(Formation of exfoliation part)
There is no restriction | limiting in particular as a formation process of a peeling part. It is preferable that the formation process of a peeling part includes the coating process of the release agent which forms a peeling part.
It is preferable that the coating method of the release agent which forms a peeling part is a pattern coating method. The pattern coating method is a coating method which can apply a composition on a base material so as to have various shapes. Thereby, the peeling part of a predetermined | prescribed shape (adhesive part is also the same) can be formed on a base material.
As a pattern coating method, there can be mentioned a part coating method by a slit coater, and a method of bringing a pattern roll on which a predetermined concavo-convex pattern is formed into contact with a substrate. In the present invention, the part coating method using a slit coater is preferred.

  In the part coating method using a slit coater, it is possible to coat a stripe-shaped composition having a longitudinal direction in the MD (transport) direction by supplying the composition to the slit coater while transporting the substrate.

  In the method of bringing a pattern roll in which a predetermined concavo-convex pattern is formed into contact with a substrate, the concavo-convex pattern is strictly formed on the pattern roll, and the supply amount of the composition to be supplied to the convex portion is controlled. The composition can be applied accurately. For example, a method using a gap between two rolls, a method using a die head, a method using a gravure head, a method using a flexo head, and the like can be mentioned as preferable methods. In the method of bringing a pattern roll with a predetermined uneven pattern in contact with a substrate, precisely formed peeling portions (same as adhesive portions) of complicated shapes such as U-shaped, dot-like (sea-island-like, reverse sea-island-like) it can. The pattern roll is preferably a relief plate such as a silicone resin plate. As a specific example of such a pattern coating method, a design coat made by Sun Tool Co., Ltd. can be mentioned.

  As a device for curing the coated release agent, a hot air dryer, a far infrared dryer, an ultraviolet irradiation device, an electron beam irradiation device and the like can be mentioned.

It is preferable that it is 0.2-2.0 g / m < ² > in dry mass, and, as for the coated amount of the release agent which forms a peeling part, it is more preferable that it is 0.5-1.5 g / m < ² >. By making a coating amount into the said range, it can be coated to an appropriate range, and the shear stress and peeling force of a label laminated body can be made into an appropriate range.

(Formation of adhesive part)
There is no restriction | limiting in particular as a formation process of the adhesion part. It is preferable that the formation process of an adhesion part includes the coating process of the adhesive which forms an adhesion part.
It is preferable that the coating process of an adhesive is a pattern coating method. When using a hot melt adhesive, the pattern coating method is preferably a part coat method using a slit coater. When using a hot melt adhesive, it is preferable to apply the hot melt adhesive mixed under heating at 120 to 200 ° C.
It is preferable to perform the formation process of the adhesion part after the formation process of a peeling part. In this case, it is preferable to perform position alignment with respect to the part in which the peeling part is not formed, and to perform the coating process of an adhesive with a pattern coating method.

  The adhesive part can also be formed by performing adhesive paste printing after providing the adhesive part on the entire surface of the substrate other than the pattern coating method. It is preferable to use a comma coater, a bar coater, a roll coater, an air knife coater, a die coater, a direct gravure coater, an offset gravure coater, a bario gravure coater, a curtain coater or the like as a method of providing an adhesive part on the entire substrate. Examples of the method for adhesive paste printing include offset printing, flexographic printing, and letter press printing (letterpress printing).

The coating amount of the adhesive for forming the pressure-sensitive portion, on a dry weight, is preferably from 5 to 50 g / m ^2, and more preferably 10 to 30 g / m ^2.
It is preferable that it is 5-50 micrometers, and, as for the coating thickness of the adhesive which forms an adhesion part, it is more preferable that it is 10-30 micrometers.
By making a coating amount into the said range, it can coat in an appropriate range and can acquire sufficient adhesiveness.

(Formation of label laminate)
There is no restriction | limiting in particular as a formation process of a label laminated body.
In the step of forming the label laminate, when bonding the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet, the first pressure-sensitive adhesive portion and the second peeling portion are laminated, and the first peeling portion and the second peeling portion are formed. It is preferable to laminate the adhesive part of For example, in order to contact the stripe-like adhesive part of the first adhesive sheet and the stripe-like peeling part of the second adhesive sheet, they are mutually offset by an integral multiple of the stripe width (preferably one) The method of laminating | stacking the adhesive sheet of 2 sheets in a state can be mentioned.
The label stack can be cut to the desired shape and size. You may cut the edge part (For example, the ear part in which only the peeling part which is not in contact with the adhesion part was formed) as needed.

<Application of Label Laminate>
The label laminate of the present invention suppresses curling and sticking of the adhesive when double-sided printing at a high temperature, so it can be used for double-sided printing with a large amount of high-speed and high-speed printing such as a pressure bonding postcard or a pressure bonding envelope It is preferably used in printer applications in which double-sided printing is performed at high temperatures.

  The features of the present invention will be more specifically described below with reference to examples and comparative examples. The materials, amounts used, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below. In addition, "%" in a present Example shows mass%, unless it refuses. Moreover, "part" shows a mass part.

Example 1
<Production of base material>
Hardwood bleached kraft pulp (LBKP) was beaten to a freeness of 430 mL (CSF) to prepare a pulp slurry having a concentration of 0.5% by mass. In this pulp slurry, 2.0% by mass of cationized starch, 0.4% by mass of alkyl ketene dimer, 0.1% by mass of anionized polyacrylamide resin, 0.7% by mass of polyamidepolyamine epichlorohydrin resin with respect to the mass of the pulp dried %, Talc as a pigment was added and dispersed thoroughly with stirring. The amount of talc added was 2% by mass with respect to the finished paper base.
Next, water was added to oxidized starch (trade name “Ace A”, manufactured by Oji Cornstarch Co., Ltd.), and the mixture was heated and dissolved to adjust the concentration to 5% by mass to obtain a size press liquid.
The pulp slurry was made into a base paper by a paper machine to obtain a base paper, and the size press liquid was used to size both sides of the base paper with a size press by a size press attached to the paper machine to obtain a paper base. The amount of absorption of the size press liquid onto the paper substrate was 50 mL / m ² in total on both sides.
Finally, calendering was performed using a machine calender at the end of a paper machine to obtain a paper substrate having a basis weight of 100 g / m ² , a density of 0.85 g / cm ³ , and a degree of sizing of 35 seconds. Moreover, it was 350 mL when the freeness after disaggregation based on the Canadian standard freeness (degree of freeness; CSF) prescribed | regulated by JISP8121 was measured about the obtained paper base material.

<Printing of pictures and characters>
A picture and character pattern were printed on one side of the obtained paper substrate (the side opposite to the recording surface when made into a label laminate) using an amine-less UV ink (trade name: NVR) manufactured by TOKA Corporation. .

<Formation of peeling portion>
100 parts by mass of a polyorganosiloxane (trade name: “Silicolyase POLY 201”, manufactured by Rhodia Co., Ltd.) and 5 parts by mass of an onium salt-based photopolymerization initiator (trade name: “Silicholys CATA 211”, manufactured by Rhodia Co., Ltd.) I got the paint.
While transporting the paper substrate, the obtained release agent paint is applied by part coating with a slit coater on the side of the paper substrate on which the picture and character pattern are printed, and UV light is applied using a metal halide UV irradiation device. The coated portion of the release agent paint was cured under the condition of an irradiation amount of 140 mJ / cm ² to provide a peeled portion.
The coating amount of the release agent paint forming this peeling portion was 1 g / m ² in dry mass (solid content mass).
Moreover, the peeling part was formed in stripe form which has a longitudinal direction in the conveyance direction (MD direction) of 5 mm of coated part width and 5 mm of uncoated part width.

<Formation of adhesive part>
Next, 18 parts by mass of a first SIS (10% by mass of styrene component, 90% by mass of isoprene component, molecular weight Mw = 5 × 10 ⁴ , degree of dispersion Mw / Mn = 1.02), second SIS (styrene component) 20 parts by mass of 30% by mass, 70% by mass of isoprene component, weight average molecular weight Mw = 5 × 10 ⁵ , dispersion degree Mw / Mn = 1.05), and 39 parts of rosin ester ("ester gum 105" manufactured by Arakawa Chemical Co., Ltd.) Parts by mass, 22 parts by mass of paraffinic oil ("Shellflex 371N" manufactured by Shell Chemical Company, USA), and 1 part by mass of an antioxidant ("Sumilyzer GM" manufactured by Sumitomo Chemical Co., Ltd.) The mixture was stirred and mixed under heating to obtain a hot melt pressure sensitive adhesive.
The hot melt adhesive obtained is part-coated by a slit coater in the area (uncoated part) sandwiched by the peeling part of the part where the peeling part of the paper base is formed while conveying the paper base The resultant was coated to form an adhesive part, to obtain an adhesive sheet.
The coating amount of the hot-melt pressure-sensitive adhesive forming this pressure-sensitive adhesive portion was 20 g / m ² in dry mass (solid content mass).
The obtained pressure-sensitive adhesive sheet is formed by alternately arranging a stripe-shaped adhesive portion having a stripe width of 3.75 mm and a stripe-shaped peeling portion having a stripe width of 5 mm. Further, in the pressure-sensitive adhesive sheet, both ends in the direction (TD direction) orthogonal to the MD direction are stripe-shaped peeling portions, and the stripe-shaped pressure-sensitive adhesive portion is positioned in the region sandwiched by the stripe-shaped peeling portions.

<Formation of label laminate>
Two pressure-sensitive adhesive sheets were prepared to obtain a first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet.
Two adhesive sheets are laminated with one stripe width mutually offset so that the stripe-like adhesive part of the first adhesive sheet and the stripe-like peeling part of the second adhesive sheet are in contact with each other. The label laminate of Example 1 was obtained.

[Examples 2 and 3]
The label laminates of Examples 2 and 3 were obtained in the same manner as Example 1 except that the second SIS of the hot melt adhesive, the rosin ester and the paraffin oil were changed as shown in Table 1 below. .

Comparative Example 1
20 parts by mass of the first SEPS (12% by mass of styrene component, 88% by mass of ethylene / propylene component, molecular weight Mw = 3 × 10 ⁴ , degree of dispersion Mw / Mn = 1.05), second SEPS (styrene component 25) 10 parts by mass of an ethylene / propylene component, an ethylene / propylene component 75 mass%, a weight average molecular weight Mw = 3 × 10 ⁵ , a dispersion degree Mw / Mn = 1.10), a rosin ester (“ester gum 105” manufactured by Arakawa Chemical Co., Ltd.) 40 parts by mass, 29 parts by mass of paraffinic oil ("Shellflex 371N" manufactured by Shell Chemical Company of the United States), and 1 part by mass of an antioxidant ("Sumilyzer GM" manufactured by Sumitomo Chemical Co., Ltd.) The mixture was stirred and mixed under heating to obtain a hot melt pressure sensitive adhesive.
A label laminate of Comparative Example 1 was obtained in the same manner as Example 1 except that the obtained hot melt pressure sensitive adhesive was used.

Comparative Example 2
The label laminate of Comparative Example 2 in the same manner as in Example 1 except that the blending amounts of the first SIS, second SIS, rosin ester and paraffinic oil of the hot melt adhesive were changed as shown in Table 1 below. I got

[Evaluation]
<Shear stress under 80 ° C environment>
The label laminate was cut to a size of 25 mm × 25 mm (for the stripe width 3.75 mm × 3 of the adhesive portion in a stripe shape), and placed under an environment of 80 ° C. for 3 hours for curing.
Thereafter, one of the first adhesive sheets is pulled in the shear direction (TD direction) of the stripe-shaped adhesive part, and fixed (the other is pulled substantially in the opposite direction to the first adhesive tape) The strength with which the adhesive part peels off from the adhesive sheet of 2 was measured by the following method.
Measurement temperature: 80 ° C
Testing machine: Shimadzu autograph AGS-J
Test speed: 300 mm / min FIG. 4 is a schematic view illustrating a method of measuring shear stress under an 80 ° C. environment. FIG. 4 shows the relationship between the first adhesive sheet 10, the second adhesive sheet 20, and the direction 40 in which the first adhesive sheet 10 is pulled by fixing the second adhesive sheet 20. The dotted arrow substantially corresponds to the direction 40 in which the fixed second adhesive sheet 20 is pulled.
The strength values obtained were taken as shear stress in the case where the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet were pulled parallel to the sheet surface in opposite directions to each other in an 80 ° C. environment.

<Shear storage modulus measured at 1 Hz in an environment of 80 ° C.>
A cylindrical sample having a diameter of 8 mm and a thickness of 2 mm was produced using the hot melt pressure-sensitive adhesive used in each of the examples and the comparative examples. The obtained sample was sandwiched in a parallel plate-like device, and the viscoelasticity of the hot melt pressure-sensitive adhesive under a temperature environment of 80 ° C. was measured by the following method.
Measuring device: TA Instruments ARES-RDA W / FCO rheometer sample shape: 8 mm diameter, 2 mm thick cylindrical frequency: 1 Hz (sine wave)
Measurement temperature: 80 ° C
The obtained viscoelasticity value was taken as the shear storage modulus measured at a frequency of 1 Hz in an 80 ° C. environment of the pressure-sensitive adhesive.
Second, shear loss elastic modulus G ′ ′ measured at 1 Hz in an 80 ° C. environment delayed by stress and 90 ° phase, shear storage elastic modulus G ′ measured at 1 Hz in an 80 ° C. environment in phase with stress It measured with the same measuring device and measurement conditions as. The loss tangent tan δ1 of the adhesive under 80 ° C. environment was calculated from the loss tangent tan δ = G '' / G '. If the loss tangent tan δ is 0, it is a perfect elastic body, and if it is ∞, it is a perfect viscous body.
Third, the loss tangent tan δ2 of the adhesive under the 25 ° C. environment was determined in the same manner as the calculation of the loss tangent tan δ1 of the adhesive under the 80 ° C. environment except that the measurement temperature was 25 ° C.
Fourth, from the obtained tan δ1 and tan δ2, the value of tan δ1 / tan δ2 and the value of | tan δ1−tan δ2 | were determined.

<Curl>
The label laminate was cut into A4 size.
Paper setting: thick paper 2, print setting: general, A4 size label laminate in the horizontal direction (TD direction) using Ricoh's digital full color multifunction machine MP C3003 (printer which is an electrophotographic printing machine) 10 sheets were passed and printed on both sides in monochrome. Thereafter, a curl measurement sample was prepared in a state in which 10 of the discharged label laminates were stacked. The curl measurement sample is placed on a flat table with the front and back determined so that the end contacts the table and the center floats, and is allowed to stand for 30 minutes from printing under an environment of 23 ° C and 50% relative humidity. The curling amount, which is the maximum value of the gap between the curl measurement sample and the table, was measured.
FIG. 5A and FIG. 5B are schematic diagrams illustrating the method of measuring the curl amount. FIG. 5 (A) is a perspective view of the curl measurement sample 100, and FIG. 5 (B) is a schematic view of a cross section of FIG. The relationship between the curl measurement sample 100, the table 101, and the curl amount 102 is shown in FIG. 5 (B).
Using the amount of curl obtained, the curl was evaluated according to the following evaluation criteria.
○: The curl amount is less than 15 mm.
Δ: The curl amount is 15 mm or more and less than 25 mm.
X: The curl amount is 25 mm or more.

<Expansion of adhesive>
The label laminate was cut into A4 size.
Paper setting: thick paper 2, print setting: 500 sheets of A4 size label laminate in horizontal direction (TD direction) with paper feed tray using Ricoh's digital full color multifunction machine MP C3003 I printed it. Check the print condition of the discharged label laminate, and check whether the image contamination is caused by the hot melt adhesive adhering to the transfer roll, the fixing roll, the photosensitive drum, etc. on the sheet passing path (conveying path) It was confirmed.
○: There is no image dirt.
X: There is image dirt.

According to the label laminate of the present invention, it has been found that curling and sticking of the pressure-sensitive adhesive are suppressed when double-sided printing is performed at a high temperature.
The shear stress measured in the 80 ° C. environment of the label laminate falls below the lower limit defined in the present invention, and the shear storage modulus measured at a frequency of 1 Hz in the 80 ° C. environment of the adhesive is defined in the present invention According to Comparative Examples 1 and 2 below the lower limit, it was found that large curling occurs when double-sided printing is performed at a high temperature, and that a pressure-sensitive adhesive overflows.

10 first adhesive sheet 11 first adhesive section 12 first peeling section 13 first substrate 14 first recording surface 20 second adhesive sheet 21 second adhesive section 22 second peeling section 23 first 2 base 24 second recording surface 30 label laminate 40 pulling direction 100 curl measurement sample 101 table 102 curl amount

Claims (7)

A label laminate having a first adhesive sheet and a second adhesive sheet;
The first adhesive sheet has a first adhesive part and a first peeling part on one side, and has a first recording surface on the other side;
The second adhesive sheet has a second adhesive part and a second peeling part on one side, and has a second recording surface on the other side;
The first adhesive portion and the second peeling portion are laminated, and the first peeling portion and the second adhesive portion are laminated;
The shear stress is 12 N / 25 mm or more when pulling the first adhesive sheet and the second adhesive sheet parallel to the sheet surface in the opposite direction in an 80 ° C. environment;
The label laminated body whose shear storage elastic modulus measured by 1 Hz of frequency in the 80 degreeC environment of the adhesive which comprises said 1st adhesion part and said 2nd adhesion part is 6000 Pa or more. The first adhesive portion is located in the plane of the second peeling portion;
The label laminated body of Claim 1 in which the said 2nd adhesion part is located in the surface of a said 1st peeling part.   The label laminated body of Claim 1 or 2 whose said 1st adhesion part and said 2nd adhesion part are two or more respectively.   The label laminated body as described in any one of Claims 1-3 whose said 1st adhesion part and said 2nd adhesion part are several stripe shape.   The label laminate according to claim 4, wherein the first peeling portion and the second peeling portion are in a plurality of stripes.   The label laminate according to any one of claims 1 to 5, wherein the first adhesive part and the second adhesive part are composed of a hot melt adhesive. The first adhesive sheet has a first base material that doubles as the first recording surface,
The label laminated body as described in any one of Claims 1-6 which has a 2nd base material which the said 2nd adhesive sheet serves as the said 2nd recording surface.

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