JP2018053400A - Heat seal sheet and package - Google Patents

Abstract

The present invention provides a heat seal sheet and a package that have air permeability and moisture permeability, are less dusty, and can be recycled. A paper base material and a thermal adhesive layer provided on the outermost surface of at least one surface of the paper base material and containing 50% by mass or more of an organic material, the thermal adhesive layer comprising the organic material The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonding surface containing the styrene-butadiene copolymer latex as at least a part of the heat-bonding layer is 50 seconds or more. A heat seal sheet characterized by [Selection figure] None

Description

  The present invention relates to a heat seal sheet and package that can be self-adhered or thermally bonded to other members, has air permeability and moisture permeability, has low dust generation, and can be recycled.

A package using a heat seal method is widely used in addition to packaging of general industrial products, packaging of foods, medicines, medical instruments, various drugs such as desiccants and freshness-preserving agents.
In particular, a package for storing a medical device is sterilized with high-pressure steam together with the package before using the medical device. In order for the medical device to be sufficiently sterilized, it is necessary that the package has appropriate air permeability and moisture permeability.
In addition, drug packaging such as desiccants and freshness-preserving agents that are enclosed with food is not sterilized, but is made of a material that is breathable and moisture-permeable, as well as safe, like medical device packaging. It is important that

As a method for encapsulating medical devices in a package simply and hygienically, a bag-like container is made with a heat seal sheet, and after inserting the medical device, the end of the opening of the container is thermally bonded with a heat sealer It has been known.
In the heat seal sheet, a heat seal layer is provided on the surface of a sheet-like substrate, and the heat seal layer adheres to an adherend by thermocompression bonding.

Patent Document 1 proposes a sterilized pack paper in which air permeability is ensured by including 25% by mass or more of an inorganic filler with respect to 100% by mass of the thermoplastic resin in the thermoplastic resin layer.
However, the sterilized pack paper described in Patent Document 1 has a problem that the inorganic filler is scattered at the time of opening and the medical device is contaminated because the heat seal layer contains a lot of inorganic filler.

  On the other hand, a breathable sheet using a sheet-like base material obtained by mixing wood pulp fibers and thermal resin fibers and having heat sealing properties by the thermal resin fibers has also been proposed (for example, Patent Document 2). However, it is extremely difficult to re-disaggregate a sheet obtained by mixing wood pulp fibers and thermal resin fibers to make recycled paper.

JP 2000-246840 A Japanese Patent Laid-Open No. 5-208473

  In view of the above circumstances, an object of the present invention is to provide a heat seal sheet and a package that have air permeability and moisture permeability, are less dusty, and can be recycled.

In order to achieve the above object, the present invention employs the following configuration.
[1] A paper base and a thermal adhesive layer provided on the outermost surface of at least one surface of the paper base and containing 50% by mass or more of an organic material, the thermal adhesive layer being made of the organic material The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the thermal adhesive surface containing styrene-butadiene copolymer latex as at least a part and provided with the thermal adhesive layer is 50 seconds or more. There is a heat seal sheet.
[2] The heat seal sheet according to [1], wherein the thermal adhesive layer further contains a rosin emulsion as a part of the organic material.
[3] The heat seal sheet according to [2], wherein a total mass of the styrene-butadiene copolymer latex and the rosin emulsion is 30% by mass or more based on a total solid content of the heat bonding layer.
[4] The heat of [2] or [3], wherein the content ratio of the rosin emulsion contained in the thermal adhesive layer is 5 to 2000 mass% with respect to 100 mass% of the styrene-butadiene copolymer latex. Seal sheet.
[5] The heat seal sheet according to any one of [2] to [4], wherein the rosin emulsion is a reinforced rosin emulsion.
[6] The heat seal sheet according to any one of [1] to [5], wherein the paper base material is single glossy paper.
[7] The heat seal sheet according to any one of [1] to [6], wherein a freeness defined by JIS P 8121-2: 2012 of the pulp constituting the paper substrate is 250 to 700 mL.
[8] A package formed by thermally bonding the heat-bonding surfaces of the heat-sealing sheet of any one of [1] to [7].
[9] A package formed by thermally bonding the heat-bonding surface of the heat-sealing sheet according to any one of [1] to [7] and another packaging material.

The present invention provides a heat seal sheet and a package that have air permeability and moisture permeability, are less dusty, and can be recycled.

[Heat seal sheet]
The heat seal sheet of the present invention is provided with a paper base material and a thermal adhesive layer provided on the outermost surface of at least one surface of the paper base material and containing 50% by mass or more of an organic material, The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonding surface containing the styrene-butadiene copolymer latex as at least a part of the organic material and provided with the heat-bonding layer. It is characterized by being 50 seconds or more.
[Paper base]
Examples of the pulp constituting the paper base include wood pulp and non-wood pulp. Wood pulp includes softwood pulp, hardwood pulp and the like. In terms of reducing the air permeability of the heat seal sheet, 50% by mass or more of the total pulp constituting the paper base material is preferably hardwood pulp, and more preferably 80% by mass or more is hardwood pulp.
Conversely, when it is desired to obtain the strength of the package, it is preferable that 50% by mass or more of the whole pulp constituting the paper base material is softwood pulp, and 80% by mass or more is softwood pulp.
Non-wood pulp includes cotton pulp, hemp pulp, kenaf pulp, bamboo pulp and the like. Materials other than pulp fiber, such as rayon fiber, nylon fiber, and other heat-bonding fibers, can be blended as auxiliary materials.

The paper base material is obtained by papermaking a papermaking raw material mainly composed of pulp slurry.
The pulp slurry is obtained from wood or non-wood raw material chips through steps such as cooking, washing and bleaching. There is no particular limitation on the cooking method, washing method, bleaching method and the like. The pulp slurry obtained through these steps is further beaten in the presence of water.

The beating method and beating apparatus are not particularly limited, but a double disc refiner (DDR) with high beating efficiency is preferably used.
The beating degree is preferably adjusted so that the freeness defined in JIS P 8121-2: 2012 (hereinafter also referred to as “standard freeness”) is 250 to 700 mL. That is, the paper base is preferably manufactured using pulp having a standard freeness of 250 to 700 mL.

The standard freeness is more preferably 300 to 600 mL, and further preferably 350 to 500 mL.
When the standard freeness is equal to or more than the preferred lower limit, the Oken air permeability of the paper substrate can be easily lowered. That is, it is easy to ensure the air permeability and moisture permeability of the paper substrate. In addition, when the standard freeness is equal to or less than the preferable upper limit value, a dense heat-sealed sheet paper base material with less unevenness of formation can be obtained. As a result, it is possible to suppress the occurrence of pinholes that reduce the bacteriostatic properties.

The paper substrate preferably contains a wet paper strength enhancer. For example, when used for a package such as a desiccant, it may be exposed to water vapor for a long time. When the paper base material contains the wet paper strength enhancer, it is possible to prevent the package from being damaged during use and the contents from leaking out.
Examples of the wet paper strength enhancer include polyamide epichlorohydrin resin, melamine formaldehyde resin, urea formaldehyde resin, vegetable gum, latex, polyethyleneimine and the like. In particular, the polyamide epichlorohydrin resin can be used preferably because it can be used in a wide pH range and a high wet paper strength can be obtained with a low addition amount.

In combination with the wet paper strength enhancer, dry paper strength enhancers such as glyoxal, gum, mannogalactan polyethyleneimine, polyacrylamide resin, polyvinyl alcohol, starch, carboxymethylcellulose, guar gum, urea resin and the like may be used.
The wet paper strength enhancer and the dry paper strength enhancer are preferably added as an internal additive or an external additive, and more preferably as an internal additive, in the paper making process of paper base production.

The ratio of the wet paper strength enhancer to the dry solid content of the pulp constituting the paper substrate is preferably 0.1 to 3.0% by mass, more preferably 0.2 to 2.0% by mass. Preferably, it is 0.3-1.0 mass%.
By setting the ratio of the wet paper strength enhancer to a preferable lower limit value or more, sufficient durability can be obtained when used in a high humidity environment. In addition, by setting the ratio of the wet paper strength enhancer to a preferable upper limit value or less, aggregates due to the wet paper strength enhancer are generated in the paper machine, and the risk that the paper base material is stained is reduced.

A paper making chemical such as a yield improver, a drainage improver, a sizing agent, and a filler may be added to the paper base as necessary.
The ratio of components other than pulp including the wet paper strength enhancer to the dry solid content of the pulp constituting the paper substrate is preferably 0.5 to 10% by mass, and 1.0 to 5.0% by mass. It is more preferable that it is 1.5-3.0 mass%.

The basis weight of the paper substrate is preferably 15~200g / m ^2, more preferably from 30 to 150 g / m ^2, further preferably 50 to 100 g / m ^2. By setting the basis weight of the paper base material to a preferable lower limit value or more, pinholes are hardly generated and strength as a packaging material can be easily obtained. Moreover, the raise of the air permeability of a paper base material can be suppressed by making the basic weight of a paper base material into a preferable upper limit or less.
Density of the paper substrate is preferably 0.40 to 0.95 g / cm ^3, more preferably ^{0.50~0.80g / cm 3, 0.60~0.75g / cm} 3 More preferably. By setting the density of the paper base material to a preferable lower limit value or more, pinholes are hardly generated. Moreover, the raise of the air permeability of a paper base material can be suppressed by making the basic weight of a paper base material into a preferable upper limit or less.

[Thermal adhesive layer]
The thermal adhesive layer of the present invention is provided on the outermost surface of at least one surface of the paper substrate, and contains an organic material of 50% by mass or more, preferably 75% by mass or more, and more preferably 95% by mass or more. When the thermal adhesive layer contains a large amount of inorganic material and the content of the organic material in the thermal adhesive layer is less than 50% by mass, sufficient thermal adhesiveness as a heat seal sheet cannot be obtained.
The thermal adhesive layer of the present invention contains a styrene-butadiene copolymer latex as at least a part of the organic material.
The thermal adhesive layer containing the styrene-butadiene copolymer latex is combined with the paper base material so that the smoothness of the surface of the thermal adhesive layer is 50 seconds or more. Appropriate breathability and moisture permeability can be imparted to the seal sheet.
Moreover, the package using the thermal adhesive layer containing the styrene-butadiene copolymer latex has little dusting property even if the thermal adhesive layer contains an inorganic pigment.

  The styrene-butadiene copolymer latex is not particularly limited, and examples of the particle structure include a single structure, a core-shell structure, and a continuous different composition structure. As for the glass transition temperature, a glass transition temperature of −50 to 30 ° C. including a different composition portion is preferable because of excellent thermal adhesiveness. More preferably, the temperature is from -10 ° C to 30 ° C. The average particle size is preferably 50 to 300 nm because of excellent thermal adhesiveness. More preferred is 70 to 150 nm.

  Furthermore, it is preferable that the thermal adhesive layer further contains a rosin emulsion as a part of the organic material in the thermal adhesive layer, since the thermal adhesiveness is not adversely affected and air permeability and moisture permeability are improved. The rosin emulsion is not particularly limited, but a reinforced rosin emulsion in which a carboxyl group is introduced into natural rosin is preferable because it has an excellent effect of expressing the thermal adhesiveness of the styrene-butadiene copolymer.

  When the thermal adhesive layer of the present invention contains a rosin emulsion, the thermal adhesive layer preferably contains the rosin emulsion in the range of 5 to 2000% by mass with respect to 100% by mass of the styrene-butadiene copolymer latex.

The coating amount of the heat-bonding layer is not particularly limited, but preferably adjusted in the range of 0.1g / m ² ~20g / m ² in solids. By setting the coating amount of the thermal adhesive layer to 0.1 g / m ² or more, stable thermal adhesiveness can be obtained. Moreover, high air permeability and moisture permeability are acquired by setting it as 20 g / m < ² > or less. More preferably ^{0.5g / m 2 ~10g / m 2} , more preferably from ^{0.5g / m 2 ~5g / m 2} .

[Smoothness of thermal bonding surface]
The Oken type smoothness measured according to JIS P 8155: 2010 of the thermal bonding surface of the present invention is 50 seconds or more. By setting it to 50 seconds or more, the heat-bonded surface exhibits a good heat-adhesive property with a heat-sealing sheet having a paper base or a paper base.

The means for setting the Oken type smoothness of the heat-bonded surface to 50 seconds or more is not particularly limited. For example, paper is made in a paper machine equipped with a mirror-finished Yankee dryer, and the wet paper is pressed against the Yankee dryer. A method of providing a heat-adhesive layer on the glossy surface of a piece of glossy paper comprising drying, making a wet paper using a normal paper machine, smoothing by an on-machine breaker stack in a semi-dry state, and / or A method of smoothing the surface of the paper substrate by providing an on-machine or off-machine calendar treatment in a dry state, a method of performing a super calender treatment after providing a heat adhesion layer on a normal paper substrate, etc. Is mentioned. In particular, the method of using glossy paper, which is made by press-contacting with a Yankee dryer and drying, as the base material has less air pressure on the paper base material during smoothing than other methods. It is preferable because a heat-sealing sheet having moisture is easily obtained.
The Oken type smoothness of the heat-bonded surface is more preferably 100 seconds or more, and further preferably 200 seconds or more.

[Other ingredients]
The thermal adhesive layer may contain other components as long as the effects of the present invention are not impaired. Other components include ethylene (meth) acrylic acid copolymer emulsion, ethylene-vinyl acetate copolymer emulsion, acrylate polymer emulsion, polyethylene and polybutene emulsion, acid-modified polyolefin resin emulsion, chlorinated polyolefin resin emulsion, Starch such as chlorinated ethylene-vinyl acetate copolymer resin emulsion, acid-modified chlorinated polyolefin resin emulsion, and acrylic polymer-modified chlorinated polyolefin resin emulsion, urethane resin emulsion, urea resin emulsion, etc., modified starch, polyvinyl Alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, Arabica Water-soluble polymer compounds such as diisobutylene / maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, mold release agent, antifoaming agent, dispersant, wetting agent, colored dye, colored pigment, white And pigments. Any one of these may be used alone, or two or more may be used in combination.

[Undercoat layer]
The heat seal sheet of the present invention can be provided with an undercoat layer containing a polyacrylamide resin on at least the surface of the paper base on the side of the heat-bonding layer for the purpose of dealing with re-peeling applications. By providing the undercoat layer, it is possible to prevent destruction of the base material at the time of peeling and to suppress the amplitude of the adhesive strength at the time of peeling. The coating amount of the undercoat layer is adjusted in a range of about 0.05~15g / ^{m 2.}

[Coating drying]
Examples of a method for applying the thermal adhesive layer coating liquid and the undercoat layer coating liquid include coating by a coater or printing by a printing machine.
Examples of the coater include a gravure coater, a curtain coater, a die coater, a gate roll coater, a shim sizer, a bar coater, an air knife coater, and a blade coater.

[Breathability of heat seal sheet]
When used as a packaging material for chemicals such as insecticides, fragrances, and other chemicals, deodorants, VOC absorbents, freshness-keeping agents, etc., the heat-seal sheet is measured in accordance with JIS P 8117: 2009. The temperament is desirably less than 160 seconds, and more desirably 5 seconds or more and less than 100 seconds.
By setting the air permeability within the above range, the diffusion rate of the drug can be adjusted appropriately.
The air permeability of the heat seal sheet can be adjusted by a combination of adjustment of freeness in the above-mentioned paper substrate manufacturing process, adjustment of the papermaking process or smoothing treatment conditions after papermaking, and the coating amount of the thermal adhesive layer. it can.

[Moisture permeability of heat seal sheet]
When used as a desiccant or oxygen scavenger, appropriate moisture permeability is required in addition to air permeability. JIS Z 0208: 40 ℃ measured according to 1976, the moisture permeability of the heat-sealing sheet of 90% RH is, 500g / m ² · 24h or more 7500g / m ² · 24h or less, more preferably 800 g / m ² It is preferably 24 h or more and 4800 g / m ² · 24 h or less.
If the moisture permeability is below the above range, the performance of the desiccant or oxygen scavenger may not be fully exhibited. Further, when the moisture permeability exceeds the above range, water is rapidly adsorbed outside the desiccant powder, and the surface of the package may become sticky or generate heat.

[Packaging using heat seal sheet]
The form of the package using the heat seal sheet of the present invention is not particularly limited, and can be used as various types of packages. For example, a vertical pillow, a horizontal pillow, a three-way seal, a four-way seal, and the like can be given.
Moreover, as a form of the package using the heat seal sheet of the present invention, the heat adhesive layers of the heat seal sheet of the present invention may be thermally bonded to each other. It may be thermally bonded to a part of the packaging material.
Examples of other packaging materials include paper, non-woven fabric, synthetic paper, pulp mold, or a sheet or molded body made of PET, PP, PE, PVC, PS, PMMA, or the like.

[Safety of heat seal sheet]
As a standard related to the safety of paper base materials, there is a positive list (Chemnet) of ingredients that can be contacted with food by the Japan Paper Association. The heat seal sheet of the present invention is not limited to the paper base material, and styrene-butadiene copolymer latex and rosin emulsion, which are the main components of the heat-adhesive layer, also have Cheminet registered brands, so it is desirable to select from these. .

[Strength of drug package]
As an example, the Japan Lime Desiccant Association has established a standard for the strength of drug packages used with foods to prevent bag breakage and damage by infants (NSKK standard).
In this standard, the tensile strength in the longitudinal direction measured in accordance with JIS P 8113: 2006 is 2.26 kN / m or more, the elongation at break in the longitudinal direction is 3.5% or more, and the tensile strength in the transverse direction is 1.96 kN. / M or more, breaking elongation in the transverse direction is 3.5% or more. Moreover, the burst strength measured based on JISP8112: 2008 is 250 kPa or more. It is determined that the thermal bond strength measured in accordance with JIS Z 0238: 1998 is 6 N / 15 mm or more, and it is desirable that these standards be satisfied depending on the application.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. In addition,% is the mass% unless there is particular notice. The “mass part” of the raw material is the mass including the dispersion medium.

[Example 1]
(Manufacture of paper base material 1)
Hardwood bleached kraft pulp (freeness defined in JIS P 8121-2: 2012: 420 mLcsf) 100 parts by mass of rosin emulsion sizing agent (trade name: AL-1200, manufactured by Japan PMC) 0.09 parts by mass, sulfuric acid 3.5 parts by weight of a band, 0.2 parts by weight of starch-grafted acrylamide paper strength agent (trade name: DG4204, manufactured by Japan PMC), release agent (trade name: Meikatex HP-68C, manufactured by Meisei Chemical Industry Co., Ltd.) Add 0.03 parts by mass, 0.6 parts by mass of cationized starch (trade name: Ace K-100, manufactured by Oji Cornstarch Co., Ltd.), and make a paper using a known long web paper machine equipped with a Yankee dryer. A glossy paper having a basis weight of 65 g / m ² and a water content of 5% was produced. The glossiness of the resulting glossy paper, measured according to JIS P 8155: 2010, was 320 seconds. Further, the air permeability measured according to 8117: 2009 of the obtained glossy paper was 46 seconds.

(Preparation of paint A for thermal adhesive layer)
Core shell type styrene-butadiene copolymer latex (trade name: A6160, manufactured by Asahi Kasei Co., Ltd., Tg of core part: -19 ° C, Tg of shell part: 26 ° C, Tg of whole latex: 21 ° C, gel fraction of 96%) A mixture of 20.8 parts by mass of a 48% aqueous dispersion, 20 parts by mass of 50 aqueous dispersion of a reinforced rosin emulsion (trade name: Size Pine N775, manufactured by Arakawa Chemical Industries) and 59.2 parts by mass of water is mixed and stirred. An adhesive layer coating material A was prepared.

(Manufacture of heat seal sheet 1)
On the glossy surface of the glossy paper obtained in the production of the paper substrate 1, the coating amount after drying the thermal adhesive layer paint obtained by the preparation of the thermal adhesive layer paint is 2.5 g / m ² . Thus, it was applied and dried using a bar coater to obtain a heat seal sheet.
The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonded surface of the obtained heat seal sheet was 260 seconds. The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 58 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 4600 g / m < ² > * 24h.

[Example 2]
(Manufacture of paper base material 2)
Hardwood bleached kraft pulp (freeness defined in JIS P 8121-2: 2012: 420 mLcsf) 100 parts by mass of rosin emulsion sizing agent (trade name: AL-1200, manufactured by Japan PMC) 0.09 parts by mass, sulfuric acid 3.5 parts by weight of a band, 0.2 parts by weight of starch-grafted acrylamide paper strength agent (trade name: DG4204, manufactured by Japan PMC), release agent (trade name: Meikatex HP-68C, manufactured by Meisei Chemical Industry Co., Ltd.) 0.03 parts by mass, 0.6 parts by mass of cationized starch (trade name: Ace K-100, manufactured by Oji Cornstarch Co., Ltd.) are added, and paper making is performed using a known long net paper machine, and the basis weight is 65 g / m. ² and high-quality paper having a water content of 5% were produced. Subsequently, a soft nip calendering process was performed on the resulting high quality paper. The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the high smooth surface of the obtained fine paper was 380 seconds. Moreover, the air permeability measured based on 8117: 2009 of the obtained glossy paper was 64 seconds.

(Manufacture of heat seal sheet 2)
Using a bar coater, apply and dry the high-quality paper obtained in Production 2 of the paper base on the smooth surface of the high-quality paper using a bar coater so that the coating amount after drying the thermal adhesive layer coating A is 2.5 g / m ² Thus, a heat seal sheet was obtained. The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonding surface of the obtained heat seal sheet was 300 seconds.
The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 850 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 3200 g / m < ² > * 24h.

[Example 3]
(Manufacture of paper base material 3)
Hardwood bleached kraft pulp (freeness defined in JIS P 8121-2: 2012: 420 mLcsf) 100 parts by mass of rosin emulsion sizing agent (trade name: AL-1200, manufactured by Japan PMC) 0.09 parts by mass, sulfuric acid 3.5 parts by weight of a band, 0.2 parts by weight of starch-grafted acrylamide paper strength agent (trade name: DG4204, manufactured by Japan PMC), release agent (trade name: Meikatex HP-68C, manufactured by Meisei Chemical Industry Co., Ltd.) 0.03 parts by mass, 0.6 parts by mass of cationized starch (trade name: Ace K-100, manufactured by Oji Cornstarch Co., Ltd.) are added, and paper making is performed using a known long net paper machine, and the basis weight is 65 g / m. ² and high-quality paper having a water content of 5% were produced.
The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the obtained high-quality paper was 20 seconds. Moreover, the air permeability measured based on 8117: 2009 of the obtained high-quality paper was 10 seconds.

(Manufacture of heat seal sheet 3)
On one side of the fine paper obtained in the production 3 of the paper base material, the thermal adhesive layer coating material A was applied and dried using a bar coater so that the coating amount after drying was 2.5 g / m ^2. A thermal adhesive layer was formed. Subsequently, the surface of the heat bonding layer was supercalendered to obtain a heat seal sheet.
The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonding surface of the obtained heat seal sheet was 300 seconds. Moreover, the air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 1000 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 3000 g / m < ² > * 24h.

[Example 4]
A heat seal sheet was obtained in the same manner as in Example 1 except that the following thermal adhesive layer coating B was used instead of the thermal adhesive layer coating A in Example 1.
(Preparation of thermal adhesive layer coating B)
Core shell type styrene-butadiene copolymer latex (trade name: A6160, manufactured by Asahi Kasei Co., Ltd., Tg of core part: -19 ° C, Tg of shell part: 26 ° C, Tg of whole latex: 21 ° C, gel fraction of 96%) 41.7 parts by weight of a 48% aqueous dispersion and 58.3 parts by weight of water were mixed and stirred to prepare a thermal adhesive layer coating material B.
The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonded surface of the obtained heat seal sheet was 260 seconds.
The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 150 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 4100 g / m < ² > * 24h.

[Comparative Example 1]
In Production 3 of the heat seal sheet of Example 3, a heat seal sheet was obtained in the same manner as in Example 3 except that the supercalender treatment was not performed after the formation of the heat-bonding layer. The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the heat-bonded surface of the obtained heat seal sheet was 18 seconds.
The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 17 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 6000 g / m < ² > * 24h.

[Comparative Example 2]
In the preparation of the thermal adhesive layer coating material of Example 1, 40 parts by mass of 50 aqueous dispersion of reinforced rosin emulsion (trade name: Size Pine N775, manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by mass of water were mixed and stirred for thermal bonding. A heat seal sheet was obtained in the same manner as in Example 1 except that the layer coating material was prepared.
The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonded surface of the obtained heat seal sheet was 260 seconds. The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 59 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 4600 g / m < ² > * 24h.

[Comparative Example 3]
A heat seal sheet was obtained in the same manner as in Example 1 except that the following thermal adhesive layer coating C was used instead of the thermal adhesive layer coating A in Example 1.
(Preparation of coating C for thermal adhesive layer)
Core shell type styrene-butadiene copolymer latex (trade name: A6160, manufactured by Asahi Kasei Co., Ltd., Tg of core part: -19 ° C, Tg of shell part: 26 ° C, Tg of whole latex: 21 ° C, gel fraction of 96%) 48% aqueous dispersion, 10.4 parts by weight of reinforced rosin emulsion (trade name: Size Pine N775, manufactured by Arakawa Chemical Industries), 8 parts by weight of amorphous silica (trade name: Mizukasil P-527) , Manufactured by Mizusawa Chemical Industry Co., Ltd., oil absorption: 165 ml / 100 g), 153.3 water dispersion (73.3 parts by mass) and water (8.3 parts by mass) were mixed and stirred to prepare a thermal adhesive layer coating material C.
The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the heat-bonding surface of the obtained heat seal sheet was 90 seconds. Moreover, the air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 40 seconds. Moreover, the water vapor transmission rate in 40 degreeC90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 5200 g / m < ² > * 24h.
[Comparative Example 4]
A heat seal sheet was obtained in the same manner as in Comparative Example 1 except that the following thermal adhesive layer coating material D was used instead of the thermal adhesive layer coating material A in Comparative Example 1.
(Preparation of paint D for thermal adhesive layer)
Preparation of thermal adhesive layer coating material D by mixing and stirring 40 parts by mass of 50% aqueous dispersion of ethylene-vinyl acetate copolymer resin (trade name: SUMIKAFLEX 753 / manufactured by Sumitomo Chemical Co., Ltd.) and 60 parts by mass of water did.
The Oken type smoothness measured in accordance with JIS P 8155: 2010 of the heat-bonded surface of the obtained heat seal sheet was 18 seconds. The air permeability measured according to JIS P 8117: 2009 of the obtained heat seal sheet was 58 seconds. Moreover, the water vapor transmission rate in 40 degreeC 90% RH measured based on JISZ0208: 1976 of the obtained heat seal sheet | seat was 4600 g / m <2> * 24h.
[Comparative Example 5]
A heat seal sheet was obtained in the same manner as in Comparative Example 1 except that the following thermal adhesive layer coating E was used instead of the thermal adhesive layer coating A in Comparative Example 1.
(Preparation of paint E for thermal adhesive layer)
44.4 parts by mass of a 45% aqueous dispersion of polyolefin resin (Mitsui Chemicals, Chemipearl EP-150H) and 55.6 parts by mass of water were mixed and stirred to prepare a coating E for a thermal adhesive layer.
The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonded surface of the obtained heat-sealing sheet was 16 seconds. Moreover, the air permeability measured based on JIS P 8117: 2009 of the obtained heat seal sheet was 18 seconds. Further, the moisture permeability of the obtained heat seal sheet at 40 ° C. and 90% RH measured according to JIS Z 0208: 1976 was 6000 g / m 2 · 24 h.
[Thermal adhesive evaluation]
A heat seal tester (model: TP-701-B, manufactured by Tester Sangyo Co., Ltd.) is stacked so that the heat-bonding surfaces of the heat seal sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 3 are in contact with each other. In use, heat sealing was performed at a sealing temperature of 150 ° C., a sealing time of 1 second, and a sealing pressure of 3 kgf / cm 2, and thermal adhesiveness was evaluated. The heat-sealed surface of the heat-seal sheet of Example 1 and the glossy surface of the single glossy paper obtained in Production 1 of the paper base material of Example 1 were heat-sealed so as to be in contact with each other. The results are summarized in Table 1.
[Evaluation criteria for thermal adhesion]
○: Adhesion is strong enough to cause substrate destruction when the adhesive part is peeled off.
X: The bonded portion peels off with a slight force.
XX: No adhesion

As is clear from the examples in Table 1, the present invention has good paper-paper adhesiveness, and as in Example 4, a good heat can be obtained by selecting a packaging material having a highly smooth surface to be bonded. Adhesiveness was obtained.
Further, Example 1 in which single glossy paper was used as a base material and a rosin emulsion was added to the heat bonding layer had a low air permeability, and was an excellent heat seal sheet suitable for various packaging materials.

Claims (9)

  A paper base material and a thermal adhesive layer provided on the outermost surface of at least one surface of the paper base material and containing 50% by mass or more of an organic material, wherein the thermal adhesive layer is at least a part of the organic material The Oken type smoothness measured according to JIS P 8155: 2010 of the heat-bonded surface provided with the styrene-butadiene copolymer latex and provided with the heat-bonding layer is 50 seconds or more. A heat seal sheet that is characterized.   The heat seal sheet according to claim 1, wherein the thermal adhesive layer further contains a rosin emulsion as a part of the organic material.   3. The heat seal sheet according to claim 2, wherein the total mass of the styrene-butadiene copolymer latex and the rosin emulsion is 30% by mass or more based on the total solid content of the thermal adhesive layer.   The heat seal sheet according to claim 2 or 3, wherein a content ratio of the rosin emulsion contained in the thermal adhesive layer is 5 to 2000 mass% with respect to 100 mass% of the styrene-butadiene copolymer latex.   The heat seal sheet according to claim 2, wherein the rosin emulsion is a reinforced rosin emulsion.   The heat-sealing sheet according to any one of claims 1 to 5, wherein the paper substrate is glossy paper. The heat seal sheet according to any one of claims 1 to 6, wherein a freeness defined by JIS P 8121-2: 2012 of the pulp constituting the paper base material is 250 to 700 mL. The package body by which the heat bonding surfaces of the heat seal sheet of any one of Claims 1-7 are heat-bonded.     The package body by which the heat bonding surface of the heat seal sheet of any one of Claims 1-7 and the other packaging material are heat-bonded.