JP2008079625A - Release paper for body warmer or for adhesive sheet for body warmer, and adhesive sheet for body warmer and body warmer using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet for a body warmer exhibiting excellent releasability even if the sheet is worked under a severe sealing condition and capable of easily releasing release paper by utilizing a certain quantity of difference in size (difference in dimensions) generated at ends of the release paper and a body warmer body because of the hygroscopic expansion of the manufactured release paper; and the release paper used therein. <P>SOLUTION: The release paper for the body warmer or for the adhesive sheet for the body warmer is characterized by the penetration in the temperature range of 23-200°C being not more than 10 μm according to the thermomechanical analysis (TMA). The release paper is also characterized by the rate of change in dimensions in at least one direction for the environmental change from 23°C 50% RH to 40°C 90% RH being at least 0.8%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a release paper used for protecting a sticky disposable warmer and an adhesive layer of the adhesive sheet for warmers. More specifically, the present invention relates to a release paper that can be easily peeled off from the body of the body during use. In addition, the present invention relates to a warming adhesive sheet and a warmer using the release paper.

  Currently, disposable warmers of the pasting type (sticking type heating element) are widely used regardless of the season for the purpose of simple heating means in winter and prevention of cooling in the cooling environment in summer (for example, (See Patent Documents 1 and 2). Such pasted disposable warmers are used, for example, by attaching them to clothing such as socks and underwear; footwear such as shoes; and skin.

  Examples of the disposable body warmer include those shown in FIG. Specifically, heat sealing means includes a porous film 2 such as polyethylene (which is often a laminated base material with a nonwoven fabric) and a plastic sheet base material 1 having a heat seal layer 11 on one side of the film layer 12. The heating element component 3 mainly composed of iron powder or the like is enclosed in the bag body. An adhesive layer 4 is formed on the surface of the plastic sheet substrate 1 on the film layer 12 side. Further, the pressure-sensitive adhesive layer 4 is sold in a state protected by a release paper (separator) 5 (that is, a state in which the release paper is bonded to the surface of the pressure-sensitive adhesive layer), and the release paper is peeled off at the time of use. Use.

  In the disposable warmer manufacturing process, heat sealing is usually performed after the release sheet 5 is bonded to the plastic sheet substrate 1 via the pressure-sensitive adhesive layer 4 to form the warming pressure-sensitive adhesive sheet 6.

  Conventionally, as a base material for the release paper, a laminate of a polyethylene resin on one side of a base paper has been generally used from the viewpoint of quality and cost. On the other hand, in recent years, with the increase in the production speed of disposable body warmers, the sealing conditions tend to be increased in temperature and pressure in order to perform the heat sealing process in a short time. Under such severe processing conditions, the polyethylene laminate type release paper has become insufficiently durable against the sealing process, and when peeling off the release paper, the release paper is heavyly peeled or torn at the heat seal portion. The problem of bad peeling has arisen. This problem is particularly noticeable when a rubber-based adhesive is used.

Japanese Patent Laid-Open No. 11-19113 JP 2002-36471 A

  An object of the present invention is to provide a release paper for a warmer or an adhesive sheet for a warmer that exhibits good peelability even under severe heat seal processing conditions.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have good releasability even when processed under severe sealing conditions by controlling the penetration of the release paper in a specific temperature range. Furthermore, by controlling the dimensional change due to moisture absorption of the release paper to a certain amount or more, a certain amount of deviation (dimension difference) occurs between the release paper and the end of the warmer body after manufacturing, and this deviation is utilized during use. The present invention has been completed by finding that the release paper can be easily peeled off.

  That is, the present invention provides a release sheet for a warmer or an adhesive sheet for a warmer, wherein the penetration by thermomechanical analysis (TMA) is 10 μm or less in a temperature range of 23 to 200 ° C.

  The present invention also relates to an adhesive sheet for a warmer or a warmer characterized in that the dimensional change rate in at least one direction with respect to an environmental change of 23 ° C. and 50% RH to 40 ° C. and 90% RH is 0.8% or more. Provides release paper for use.

  Furthermore, the present invention provides the above-described release paper for a warmer or a warmer pressure-sensitive adhesive sheet made of any substrate selected from glassine paper, paper coated with an acrylic resin, and paper coated with a polyvinyl alcohol resin.

  Furthermore, this invention provides the adhesive sheet for warmers which uses said release sheet for adhesive sheets for warmers.

  Furthermore, this invention provides said adhesive sheet for warmers which can be easily peeled when a dimensional difference of 0.3 to 1.0 mm occurs between the end of the warmer body and the release paper.

  Furthermore, this invention provides said adhesive sheet for warmers whose peeling force between release paper and an adhesive layer is 0.2-4.0 (N / 50mm).

Alternatively, the present invention provides (1) a plastic sheet substrate comprising a heat seal layer having a thickness of 3 to 15 μm comprising an olefin resin and a film layer having a thickness of 30 to 80 μm comprising an olefin resin;
(2) A pressure-sensitive adhesive layer made of a rubber-based pressure-sensitive adhesive and having a thickness of 15 to 100 μm;
(3) Cairo adhesive having release paper having a thickness of 30 to 80 μm composed of any substrate selected from glassine paper, paper coated with acrylic resin, and paper coated with polyvinyl alcohol resin and a silicone release agent layer Provide a sheet.

  Furthermore, the present invention provides a warmer using the above-described release paper for a warmer or a pressure-sensitive adhesive sheet for warmers or an adhesive sheet for warmers.

  The release paper for warmers or adhesive sheets for warmers of the present invention can be easily peeled off when used even when processed under severe heat seal conditions. As a result, the production rate can be improved, which is industrially beneficial.

[Release paper for warmers or adhesive sheets for warmers]
Hereinafter, the form of the release paper for a warmer or an adhesive sheet for a warmer of the present invention (hereinafter simply referred to as “(release) of the present invention)” will be described with reference to the drawings. FIG. 2 is a schematic sectional view showing an embodiment of the release paper of the present invention. The first embodiment of the release paper of the present invention (glassine release paper 5a) has a structure in which a release agent layer 51 such as a silicone resin is laminated on one surface of a substrate made of glassine paper 52. The second embodiment of the release paper of the present invention (resin coating type release paper 5b) is a base material in which a coating layer 53 made of acrylic resin or polyvinyl alcohol resin is laminated on one surface of a base paper 54. In this structure, the aforementioned release agent layer 51 is laminated on the surface of the coating layer 53.

  The release paper of the present invention has a structure in which a release agent layer such as silicone resin is laminated on at least one surface of a substrate such as glassine paper. As the base material, glassine paper or paper whose surface is coated with resin (hereinafter referred to as “resin-coated paper”) can be used.

  As the resin used for the resin-coated paper, an acrylic resin or a polyvinyl alcohol resin, which is a heat-resistant resin, is used from the viewpoint of durability against heat seal processing. Further, the base paper used for the resin-coated paper is not particularly limited, but fine paper, pure white paper, glossy paper, and the like are preferably used.

  When polyethylene laminate paper is used as the base material of the release paper, the pressure-sensitive adhesive sheet made of the release paper is heat-sealed (heat-compressed by an uneven processing machine surface) under severe conditions of, for example, 150 ° C. or higher. The polyethylene layer with low heat resistance is greatly deformed along the unevenness of the processing machine surface. For this reason, the release agent layer described later is in a state of being destroyed along with this, and as a result, the adhesive layer and the polyethylene layer are firmly bonded to each other, and the easy release property of the release paper is deteriorated. Problems such as tearing occur. On the other hand, as release paper, release paper (glassine release paper) provided with a release agent layer directly on glassine paper, or release paper (resin coating type release paper) coated with the above-mentioned specific heat-resistant resin layer ), The base material is not easily deformed and the release agent layer is not destroyed, so that easy releasability is maintained.

  Although it does not specifically limit as a mold release agent used in the said mold release process layer, A silicone type mold release agent, a fluorine-type mold release agent, a long-chain alkyl type mold release agent etc. are illustrated preferably. Of these, silicone release agents are particularly preferable.

  The penetration of the release paper of the present invention at 23 to 200 ° C. is 10 μm or less, preferably 0 to 7 μm. The above-mentioned penetration is obtained by measuring the release treatment surface (the surface on the side of the release agent layer) with a load of 49.0 mN and a probe diameter of 1.0 mmφ by a thermomechanical analysis (TMA) penetration method. When the penetration exceeds 10 μm, the release agent layer is greatly deformed during heat sealing to cause destruction, and the easy peelability is deteriorated as described above. The penetration of the release paper of the present invention can be obtained by using the glassine release paper or the resin coating type release paper described above as the base material of the release paper.

  The dimensional change rate in at least one direction with respect to the environmental change of 23 ° C. 50% RH to 40 ° C. 90% RH of the release paper of the present invention is 0.8% or more, preferably 1.0% or more, more preferably Is 1.2% or more. As used herein, “at least one direction” is the direction with the largest dimensional change, and generally refers to the width (CD) direction. When the rate of dimensional change is less than 0.8%, the release paper does not expand sufficiently between the time of manufacture and use, and the release paper and the body of the warmer (specifically, a plastic film sheet base material) Since a sufficient dimensional difference does not occur, peeling using the dimensional difference cannot be performed. On the other hand, the upper limit of the dimensional change rate of the release paper of the present invention is not particularly limited, but is preferably about 1.5%.

  The release paper of the present invention is a release paper (glassine release paper) provided with a release agent layer directly on glassine paper or a release paper made of resin-coated paper coated with a specific heat-resistant resin layer as described above. Therefore, the above relatively large dimensional change rate can be achieved. With a release paper having a relatively hard polyethylene layer, such as a polyethylene laminate release paper, the dimensional change of the base paper is suppressed by the fixing effect of the polyethylene layer, and the above dimensional change rate cannot be achieved.

10-200 micrometers is preferable and, as for the thickness of the release paper of this invention, More preferably, it is 30-80 micrometers. When the release paper is glassine release paper, the thickness of the glassine paper is preferably 30 to 80 μm, and the thickness of the release agent layer is preferably 0.1 to 2.0 μm. When the release paper is a release paper using a resin-coated paper base, the thickness of the base paper is 30 to 80 μm, the thickness of the resin coating layer is 1 to 10 μm, and the release agent layer thickness is 0.1 to 2 0.0 μm is preferable. The basis weight of the release paper of the present invention, the cost, in terms of texture, preferably 30 to 80 g / m ^2, more preferably from 40 to 60 g / m ^2.

  Examples of release paper satisfying the above characteristics include “64GS, 55GS, 70GS, 40ES” manufactured by Oji Special Paper Co., Ltd. (hereinafter, glassine release paper); “44EVS” manufactured by Oji Special Paper Co., Ltd. (polyvinyl alcohol resin coating) Release paper made of paper) and the like.

[Cairo adhesive sheet]
The release paper of the present invention is laminated with a plastic sheet substrate and a pressure-sensitive adhesive layer, and is used as a warmer pressure-sensitive adhesive sheet (hereinafter simply referred to as “(the present invention) pressure-sensitive adhesive sheet”) in a subsequent warmer manufacturing process. Hereinafter, the form of the adhesive sheet of this invention is demonstrated, referring drawings. FIG. 3 is a schematic cross-sectional view showing an example of the pressure-sensitive adhesive sheet of the present invention. 3 is provided with a pressure-sensitive adhesive layer 4 on the film layer 12 side of the plastic sheet substrate 1 having the heat seal layer 11 on one side of the film layer 12, and further the pressure-sensitive adhesive layer 4 The release paper 5 is temporarily fixed so that the surface of the pressure-sensitive adhesive layer 4 on which the release agent is applied is in contact with the release paper 5.

  The plastic sheet substrate used for the pressure-sensitive adhesive sheet of the present invention comprises at least a two-layer structure of a film layer and a heat seal layer.

  As resin which forms the said film layer, a polyester-type resin, an olefin resin, etc. can be used, for example. Among these, from the viewpoint of price and flexibility, an olefin resin can be preferably used. As an olefin-based resin, at least an olefin component (an α-olefin such as ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, heptene-1, octene-1, etc.) is a monomer. The resin is not particularly limited as long as it is a resin as a component. For example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer (for example, In addition to ethylene resins such as ethylene-propylene copolymer), propylene resins (polypropylene, propylene-α-olefin copolymer, etc.), polybutene resins (polybutene-1, etc.), poly-4-methyl, etc. Examples include pentene-1. The α-olefin in the ethylene-α-olefin copolymer is not particularly limited as long as it is an α-olefin other than ethylene. For example, propylene, butene-1, pentene-1, hexene-1, 4- Examples thereof include α-olefins having 3 to 10 carbon atoms such as methyl-pentene-1, heptene-1, and octene-1. Accordingly, examples of the ethylene-α-olefin copolymer include an ethylene-propylene copolymer and an ethylene- (butene-1) copolymer. The α-olefin in the propylene-α-olefin copolymer can be appropriately selected from α-olefins having 4 to 10 carbon atoms, for example. In addition, ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers; ionomers; ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene -Ethylene- (meth) acrylic acid ester copolymers such as methyl methacrylate copolymer; ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, and the like can also be used. These resins can be used alone or in combination of two or more.

  Among the above, as the resin for forming the film layer, from the viewpoints of strength as a base material, heat resistance to heat of heat seal processing and adhesion with a heat seal layer, the above-mentioned propylene-based resin and ethylene-based resin are used. Blends are preferred. Although a blend ratio is not specifically limited, For example, 5-50% of ethylene-type resin is preferable.

  The film layer may be a single layer film or a laminated film having two or more layers. Further, the film may be a non-oriented film or a film stretched and oriented in a uniaxial or biaxial direction, but is preferably a non-oriented film.

  The heat seal layer can be formed of a heat sealable resin composition containing a heat sealable resin (heat sealable resin). Such a heat-sealable resin is not particularly limited, but an olefin resin can be suitably used. The olefin resin can be selected from olefin resins exemplified as those used in the film layer. Among them, as the heat-sealable olefin resin, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene from the viewpoint of easy heat-seal processing with the porous film surface. -A methyl methacrylate copolymer (EMA), an α-olefin, and a blend thereof are preferably used. Particularly preferred is linear low density polyethylene (metallocene LLDPE) produced with a metallocene catalyst.

  In order to enable low-temperature heat sealing and easily perform high-speed processing, it is effective to use a heat-sealable resin having a relatively low melting point. For this purpose, for example, a low-temperature heat sealing resin prepared using a metallocene catalyst is used. Density polyethylene and the like are the most effective. The melting point of the resin used for the heat seal layer is preferably 80 to 105 ° C, more preferably 90 to 100 ° C. On the other hand, the melting point of the resin used for the film layer is preferably 100 to 160 ° C, more preferably 115 to 160 ° C.

  The heat seal layer may have either a single layer or a multiple layer form. The heat seal layer may be a heat seal layer having a porous property (for example, a heat seal layer made of a porous film) from the viewpoints of air permeability and oxygen supply to a heating element component. It may be a heat seal layer made of a porous polymer film (particularly, a polyethylene porous film).

  10-500 micrometers is preferable, as for the thickness of the plastic sheet base material of this invention, More preferably, it is 12-200 micrometers, More preferably, it is 15-100 micrometers. The film layer thickness is preferably 30 to 80 μm, more preferably 50 to 80 μm, and the heat seal layer thickness is preferably 3 to 15 μm, more preferably 5 to 10 μm.

  The dimensional change rate of the plastic sheet substrate of the present invention with respect to the environmental change of 23 ° C. and 50% RH to 40 ° C. and 90% RH is preferably 1.0% or less (for example, 0 to 1.0%), more preferably 0. 0.5% or less (for example, 0 to 0.5%). When the dimensional change rate exceeds 1.0%, a sufficient dimensional difference is not generated between the release paper and the dimensional difference may not be peeled off.

  The pressure-sensitive adhesive layer of the present invention is provided on one surface of the plastic sheet substrate (the surface opposite to the heat seal layer), and plays a role of attaching a warmer to an adherend during use. The pressure-sensitive adhesive is not particularly limited, and examples thereof include rubber-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, and vinyl alkyl ethers. Known pressure-sensitive adhesives such as a pressure-sensitive adhesive and a fluorine-based pressure-sensitive adhesive can be used. Moreover, the said adhesive can be used individually or in combination of 2 or more types. Among them, as described above, the phenomenon of the present invention is remarkable in the case of a rubber-based pressure-sensitive adhesive, and particularly preferable in the case of a rubber-based pressure-sensitive adhesive because the effects of the present invention are remarkably exhibited. Moreover, the form of the said adhesive is not specifically limited, For example, an emulsion type adhesive, a solvent-type adhesive, a hot-melt-type adhesive (hot-melt-type adhesive) etc. can be used.

  Examples of the rubber-based pressure-sensitive adhesive include natural rubber and various synthetic rubbers [for example, polyisoprene rubber, styrene / butadiene (SB) rubber, styrene / isoprene (SI) rubber, styrene / isoprene / styrene block copolymer ( SIS) rubber, styrene / butadiene / styrene block copolymer (SBS) rubber, styrene / ethylene / butylene / styrene block copolymer (SEBS) rubber, styrene / ethylene / propylene / styrene block copolymer (SEPS) rubber, Styrene / ethylene / isoprene / styrene block copolymer (SIPS) rubber, styrene / ethylene / propylene block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene, and modified products thereof are used as base polymers. Rubber adhesive That. Among these, SIS and SBS are preferable. These 1 type or 2 or more types of mixtures can be selected suitably, and can be used.

  When applying the pressure-sensitive adhesive layer on the plastic sheet substrate, a known or commonly used coating method, for example, an appropriate coating method such as a roll coating method, a die coating method, a melt blow or a curtain spray method, etc. should be used. Can do. In addition to the direct coating, the pressure-sensitive adhesive layer may be formed by forming a pressure-sensitive adhesive layer on the release paper and then transferring it to a plastic sheet substrate.

  The pressure-sensitive adhesive layer may be formed entirely or partially on one side of the plastic sheet substrate. In addition, in order to ensure the air permeability of a base material, it is preferable that the adhesive layer is partially formed in the single side | surface of a base material. For example, the pressure-sensitive adhesive layer may be partially formed in a stripe shape using stripe coating and in a dot shape using dot coating.

  The thickness of the pressure-sensitive adhesive layer (thickness after drying or curing) is preferably 10 to 200 μm, more preferably about 15 to 100 μm, from the viewpoints of adhesive strength and cost.

  In the pressure-sensitive adhesive sheet of the present invention, the peeling force between the pressure-sensitive adhesive layer and the release paper (180 ° peel: conforming to JIS K 6854) is preferably 0.2 to 4.0 (N / 50 mm), more preferably 0.00. 2 to 1.0 (N / 50 mm). When the peel force is less than 0.2 (N / 50 mm), the “peel” of the release paper is likely to occur particularly in the heat seal part (in the seal part and the non-seal part, due to the presence / absence of contents) A “step” has occurred, and peeling occurs when the peeling force (adhesion force) is smaller than the repulsive force of the release paper. When the peeling force exceeds 4.0 (N / 50 mm), it is difficult to peel off the release paper, and the release paper may be torn during peeling. The release force can be controlled by the composition of the adhesive and release paper, the composition and amount of the release agent, and the like.

  In the case of a release paper having a conventional base paper / polyethylene laminate layer / release agent layer configuration, the adhesive layer is formed because the heat and pressure of the heat seal causes the polyethylene layer to deform following the unevenness of the heat seal roll surface. In addition, since the adhesive force was increased by slightly breaking the release agent layer, the problem of “floating” did not occur. However, as described above, in the case of severe heat sealing conditions, the release agent layer is completely destroyed, the adhesive layer and the polyethylene layer adhere to each other, and the peeling force becomes too large, making it difficult to peel off the release paper. There was a problem.

  When the pressure-sensitive adhesive sheet of the present invention is environmentally changed from 23 ° C. and 50% RH to 40 ° C. and 90% RH), the edge of the plastic sheet substrate and the edge of the release paper are 0.3 mm or more in at least one direction. It is preferable that a dimensional difference (deviation) occurs, more preferably 0.5 to 1.0 mm. Since a deviation of 0.3 mm or more is generated between the plastic sheet substrate and the release paper, it is preferable that the release paper can be easily peeled off using this “deviation” as a “trigger” when using a warmer.

  The pressure-sensitive adhesive sheet of the present invention uses release paper that has a large dimensional change (expansion) due to moisture absorption. On the other hand, the plastic film used for the plastic sheet substrate has a very small dimensional change due to moisture absorption with respect to the release paper. For this reason, immediately after the body warming (7a and b in FIG. 4), in which the release paper and the plastic sheet substrate are pasted and cut into a specific width and processed, both have the same dimensions, but there is a certain amount of moisture When stored below (7c, d in FIG. 4), the release paper expands more than the plastic sheet, resulting in a dimensional difference 9 between the release paper and the plastic sheet (FIG. 4). That is, since the release paper slightly protrudes from the end of the body of the warmer body, this can be used as an opportunity to easily release the release paper. In addition, since a certain amount of moisture is added to the contents of a general disposable body warmer product, a certain amount of moisture is present in the bag of the body warmer product, and this effect can be caused by this moisture. .

[Cairo]
The pressure-sensitive adhesive sheet of the present invention is heat-sealed with a porous film to form a bag (a heating element is enclosed inside the bag), and the warmer of the present invention is formed. The configuration of the warmer of the present invention is the same as that shown in FIG.

  As the porous film of the present invention, a breathable substrate used in conventional disposable warmers can be used, and is not particularly limited. For example, a nylon nonwoven fabric (nylon nonwoven fabric) is laminated on a polyethylene porous film. (For example, a product name “BRESLON” manufactured by Nitto Lifetech Co., Ltd.) is preferably used.

In the present invention, the bag body is formed in a state where the surface on the porous film side and the surface on the heat seal (laminate) layer side of the adhesive sheet (surface opposite to the adhesive layer forming surface) face each other. It is done by heat-sealing so that it becomes a body. The method (apparatus) for heat sealing is not particularly limited, but pressure bonding with a heat sealer is preferable. The heat seal temperature at that time is preferably 90 to 250 ° C, more preferably 130 to 200 ° C. The pressure is preferably 0.5 to 30 kg / cm ² , more preferably 2.0 to 10 kg / cm ² . Moreover, 0.02-1.0 second is preferable from a viewpoint of productivity, and, as for heat-sealing time, More preferably, it is 0.05-0.5 second.

  The heating element of the present invention can be a heating element used in conventional disposable warmers, and is not particularly limited. For example, metal powder such as iron powder, activated carbon, water, water retention agent (wood powder, vermiculite, Diatomaceous earth, perlite, silica gel, alumina, water-absorbing resin, etc.), sodium chloride, and the like can be used.

  Furthermore, the said warmer is stored in an outer bag and sold as a warmer product. The base material constituting the outer bag is not particularly limited, and examples thereof include plastic base materials, fiber base materials (nonwoven fabric base materials and woven base materials made of various fibers), metal base materials (various types). For example, a metal foil-based substrate made of a metal component can be used. As such a base material, a plastic base material can be suitably used. Examples of plastic base materials include polyolefin base materials (polypropylene base materials, polyethylene base materials, etc.), polyester base materials (polyethylene terephthalate base materials, etc.), styrene base materials (in addition to polystyrene base materials). Styrene copolymer base materials such as acrylonitrile-butadiene-styrene copolymer base materials), amide resin base materials, acrylic resin base materials and the like. In addition, the base material for outer bags may be a single layer or a laminate. The thickness in particular of an outer bag is not restrict | limited, For example, 30-300 micrometers is preferable.

  Moreover, it is preferable that the said outer bag has a layer (gas barrier property layer) which has the characteristic (gas barrier property) which blocks | prevents permeation | transmission of gas components, such as oxygen gas and water vapor | steam. Although it does not specifically limit as a gas barrier layer, For example, an oxygen barrier resin layer (For example, a polyvinylidene chloride resin, an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, a polyamide resin), a water vapor barrier resin layer (For example, a polyolefin resin, a polyvinylidene chloride resin), an oxygen barrier property or a water vapor barrier inorganic compound layer (for example, a metal simple substance such as aluminum, a metal oxide such as a metal oxide such as silicon oxide or aluminum oxide) Etc.). The gas barrier layer may be a single layer (or the outer bag base material itself) or a laminate.

  The outer bag may be in any form or structure, for example, a so-called “four-side bag”, a so-called “three-side bag”, a so-called “pillow bag”, a so-called self-supporting type bag (a so-called “standing bag”). Pouches)) and so-called “gusset bags”. Among these, a four-sided bag is particularly preferable. The outer bag may be produced using an adhesive, but is preferably produced by heat sealing (thermal fusion) such as a four-way heat sealing bag.

  Since the warmer of the present invention has an adhesive layer, it is preferably used as a warmer (particularly disposable warmer) that is used by being attached to clothing or footwear.

[Methods for measuring physical properties and methods for evaluating effects]
Below, the measuring method used by this application and the evaluation method of an effect are illustrated.

(1) Needle penetration (TMA)
The penetration of the release treated surface of the release paper (the surface on the release agent layer side) was measured by thermomechanical analysis (TMA) according to the following measurement conditions.
(Measurement condition)
Measurement mode: Penetration method Measurement load: 49.0 mN
Probe diameter: 1.0mmφ
Temperature program: Room temperature (23 ° C) → 200 ° C
Temperature increase rate: 5 ° C / min

(2) Dimensional change rate A sample piece having a length of 300 mm and a width of 300 mm was cut out from the release paper and used for measurement.
Using a constant temperature and humidity chamber, the sample was allowed to stand for 5 hours in an atmosphere of 23 ° C. and 50% RH, and then marked lines with a marked line interval of 200 mm (L ₀ ) were inserted. Thereafter, the sample was transferred to a 40 ° C., 90% RH atmosphere, allowed to stand for 24 hours, the marked line interval (L ₁ ) was measured, and the dimensional change rate was calculated according to the following formula.
Dimensional change rate (%) = (L ₁ −L ₀ ) / L ₀ × 100
The measurement direction is the direction with the largest dimensional change, and is generally the longitudinal (MD) direction (flow direction in the release paper manufacturing process) or the width (CD) direction. For this reason, it is only necessary to measure in the MD and CD directions and adopt the larger dimensional change rate. When the MD and CD directions are unknown, for example, the dimensional change rate is obtained for 9 directions in 10 ° increments from any direction, and the direction having the largest dimensional change rate is set as the measurement direction.

(3) Peeling force The pressure-sensitive adhesive sheet having a peeling film is subjected to a 180 ° peeling test (in accordance with JIS Z 0237) under the following conditions with both of the peeling film and the pressure-sensitive adhesive film as both ends. And the peeling force of the release layer surface of the release film).
Equipment: “Shimadzu Autograph” manufactured by Shimadzu Corporation
Sample width: 50mm
Tensile speed: 300 mm / min Temperature and humidity environment: 23 ° C., 50% RH
Number of repetitions: n = 3

(4) Heat-sealed state and easy peelability of seal part Using a pressure-sensitive adhesive sheet for Cairo and a porous film ("Bresslon" manufactured by Nitto Lifetech Co., Ltd.) prepared in Examples and Comparative Examples, the seal temperature is 140. Heat seal using 4 conditions of ℃, 150 ℃, 160 ℃, 170 ℃, seal pressure is 4 kg / cm ² , seal time is 0.5 seconds, using “heat seal tester” manufactured by Tester Sangyo Co., Ltd. A Cairo was produced.
The state of the warmer after heat sealing was observed, the release paper was further peeled from the warmer, and the sealed state and easy peelability were evaluated according to the following criteria.
It is heat-sealed neatly and the release paper can be easily peeled off. … ○ (Good)
There is a catch when peeling the release paper of the heat seal part. … △ (Available)
When the release paper at the heat seal portion was peeled off, the release paper was broken. … × (Bad)

(5) Dimensional change (displacement) amount and easy peelability at the end of the body of the warmer and the end of the release paper and easy peelability The warmer product produced in the examples and comparative examples (in the outer bag) is in an atmosphere of 23 ° C. and 50% RH. After leaving for one week under, the warmer was taken out and the amount of misalignment between the end of the warmer body (plastic film substrate) and the end of the release paper was measured.
Further, the release paper was peeled off using the above “deviation” portion as a “trigger” to evaluate the peelability.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
As a plastic sheet substrate, a film layer (thickness: 70 μm) made of polyolefin (70% polypropylene (PP) and 30% linear low density polyethylene (LLDPE)) and a heat seal layer (thickness) made of metallocene LLDPE A polyolefin film (thickness: 80 μm) having a thickness of 10 μm was used.
Styrene / isoprene / styrene (SIS) hot melt adhesive is applied to the surface of the release layer side of glassine release paper (“64GS” manufactured by Oji Specialty Paper Co., Ltd., basis weight 64 g / m ² ). Hot melt pressure-sensitive adhesive coating was carried out to a thickness of 35 μm. Next, the release paper provided with the pressure-sensitive adhesive layer is bonded to the plastic sheet base so that the pressure-sensitive adhesive layer side and the film layer side (opposite side to the heat seal layer) are in contact with each other, to obtain a pressure-sensitive adhesive sheet for warmers. It was used for the seal processing state test.
Furthermore, the obtained adhesive sheet and porous film (manufactured by Nitto Lifetech Co., Ltd., “BRESRON”) are heat sealed with a seal width of 15 mm (heat seal conditions: 140 ° C., 4 kg / cm ² , 0.5 seconds, A heat seal plate having a concavo-convex finish on the surface was used to prepare a warmer. In addition, the content of the commercially available body warmer (a mixture containing iron powder as a main component) was used as the heating element.
Furthermore, the warmer is put into an outer bag (using a commercially available warmer outer bag (a gas barrier film containing PP as a main component)), and the outer bag is sealed by heat sealing to produce a warmer product. It was used for evaluating the dimensional change (deviation) amount between the edge and the edge of the release paper and easy peelability.
As shown in Table 1, the pressure-sensitive adhesive sheet obtained above had an excellent finish even when heat-sealed at a high temperature, and showed good easy peelability. Further, the end of the release paper protruded from the end of the body of the warmer during use, and this could be easily peeled off as a “trigger”.

Example 2
Cairo adhesive sheet, warmer and warmer product in the same manner as in Example 1 except that polyvinyl alcohol resin-coated paper (Oji Special Paper Co., Ltd. “44EVS”, basis weight 44 g / m ² ) was used as the release paper. Got.
As shown in Table 1, the pressure-sensitive adhesive sheet obtained above showed excellent sealability and easy peelability although it was slightly inferior when heat-sealed at 170 ° C. Further, the end of the release paper protruded from the end of the body of the warmer during use, and this could be easily peeled off as a “trigger”.

Comparative Example 1
Cairo adhesive sheets, warmers and warmers products were obtained in the same manner as in Example 1 except that polyethylene laminate type release paper (basis weight 52 g / m ² ) was used as the release paper.
As shown in Table 1, the pressure-sensitive adhesive sheet obtained above could not be used when it was heat-sealed at a high temperature of 150 ° C. or higher because peeling became difficult and tearing occurred. Further, even during use, there was no deviation between the end of the body warmer and the end of the release paper, and peeling was difficult.

It is a schematic sectional drawing which shows an example of a pasting type body warmer. It is a schematic sectional drawing which shows an example of the release paper of this invention. It is a schematic sectional drawing which shows an example of the adhesive sheet for warmers of this invention. It is the schematic (sectional drawing and front view) which shows generation | occurrence | production of the shift | offset | difference by the dimensional change of the release paper immediately after manufacture of the warmer of this invention, and at the time of use.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic sheet base material 11 Heat seal layer 12 Film layer 2 Porous film 3 Heat generating body 4 Adhesive layer 5 Release paper 5a Glassine release paper 5b Resin coating type release paper 51 Release agent layer 52 Glassine paper 53 Resin coating layer 54 Base paper 6 Cairo adhesive sheet 7a Cairo (immediately after production, sectional view)
7b Cairo (immediately after production, front view)
7c Cairo (when used, cross-sectional view)
7d Cairo (front view when in use)
8 Seal part 9 Misalignment (extruding part of release paper)

Claims (8)

  A release paper for a warmer or a pressure-sensitive adhesive sheet for warmers, wherein the penetration by thermomechanical analysis (TMA) is 10 μm or less in a temperature range of 23 to 200 ° C.   A release sheet for a warmer or an adhesive sheet for a warmer, wherein a dimensional change rate in at least one direction with respect to an environmental change of 23 ° C. and 50% RH to 40 ° C. and 90% RH is 0.8% or more.   The release paper for an adhesive sheet for warmers or for warmers according to claim 1 or 2, comprising any substrate selected from glassine paper, paper coated with acrylic resin, and paper coated with polyvinyl alcohol resin.   The adhesive sheet for warmers which uses the release paper for adhesive sheets for warmers as described in any one of Claims 1-3.   The pressure-sensitive adhesive sheet for warmers according to claim 4, which can be easily peeled when a dimensional difference of 0.3 to 1.0 mm occurs between the end of the warmer body and the release paper.   The pressure-sensitive adhesive sheet for warmers according to claim 4 or 5, wherein the peeling force between the release paper and the pressure-sensitive adhesive layer is 0.2 to 4.0 (N / 50 mm). (1) A plastic sheet base material comprising a heat seal layer made of olefinic resin having a thickness of 3 to 15 μm and a film layer made of olefinic resin and having a thickness of 30 to 80 μm;
(2) A pressure-sensitive adhesive layer made of a rubber-based pressure-sensitive adhesive and having a thickness of 15 to 100 μm;
(3) Cairo adhesive having release paper having a thickness of 30 to 80 μm composed of any substrate selected from glassine paper, paper coated with acrylic resin, and paper coated with polyvinyl alcohol resin and a silicone release agent layer Sheet.   A warmer comprising the release sheet for a warmer or a pressure-sensitive adhesive sheet for warmers according to any one of claims 1 to 3, or a warmer pressure-sensitive adhesive sheet according to any one of claims 4 to 7.

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