JP2019178201A - Adhesive article - Google Patents

Abstract

To provide an adhesive article having moderate adhesive force to containers, having no rise of the adhesive force with time, capable of securing adhesiveness of adhesive faces each other, and adapted to food sanitation law.SOLUTION: There is provided an adhesive article manufactured by arranging an adhesive layer mainly containing a synthetic rubber on a single surface of a substrate, and the adhesive layer consists of an adhesive composition with amount a tackifier resin of 60 pts.mass or less based on 100 pts.mass of the synthetic rubber.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive article to be attached to a food packaging container or the like.

  Plastic containers, bags, and films (hereinafter “containers”) are used to protect foods and the like from drying and contamination with foreign matter. In order to enter the type of contents, storage date, and the like in these containers, it is common practice to attach an adhesive tape, an adhesive label, etc. (hereinafter “adhesive article”) to the surface of the container.

  In addition, in consideration of convenience such as making the adhesive article easy to peel off from containers, it is not uncommon for a consumer to fold end portions and bond the adhesive surfaces together.

The pressure-sensitive adhesive article needs an appropriate pressure-sensitive adhesive force for containers. For example, when the adhesive strength of the adhesive article is too high, problems such as tearing when the container is peeled off (when the container is a thin film such as a bag) and adhesive residue on the container may occur.
On the other hand, when the adhesive strength of the adhesive article is too low, it is expected that the adhesive article will be peeled off when the consumer carries it. When the adhesive article is peeled off from the containers, the storage date of the food becomes unclear, and there may be a concern that the consumer eats the food having a reduced freshness such as fresh food.

  Therefore, the pressure-sensitive adhesive article is required to have an appropriate pressure-sensitive adhesive force so as not to cause these problems and to have high adhesion between the pressure-sensitive adhesive surfaces so that the folded portion can be easily formed.

  By the way, since food packaging containers are naturally assumed to come into contact with foods, they must conform to predetermined standards such as the Food Sanitation Law. Accompanying this, it is needless to say that the adhesive article to be affixed to the adhesive layer needs to satisfy the same standard, considering that the components from the adhesive layer adhere and invade the container surface during storage.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2014-34400) discloses an invention of a film roll that facilitates the visibility and drawability of the leading end of the film. It is described that it is effective to use a drawer label (adhesive article) having a predetermined adhesive strength as means for ensuring visibility and drawability from the film roll. The drawer label has a pressure-sensitive adhesive layer formed on a support made of synthetic paper, and examples of the pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives. Agents are preferred (0017). However, as a means for ensuring a suitable adhesive strength, it is described that it can be controlled by adjusting the kind of adhesive, the coating pattern of the adhesive layer, and the thickness of the adhesive layer (0021). Not only is the composition of the adhesive unknown, but the preferred range of the thickness of the pressure-sensitive adhesive layer is not clear.
Moreover, although it is described that the strength of the adhesive layer can be adjusted by the area to kill paste (0017), according to the knowledge of those skilled in the art, the adhesive strength inherent to the adhesive composition itself does not change, It is clear that only the part that has not been slaughtered causes the adhesive residue.

  Patent Document 2 (Japanese Patent Laid-Open No. 2007-145430) discloses an invention of a film device in which a guide tape (adhesive article) is always in a position where a container opening can be easily found. However, the adhesive strength of the guide tape is not particularly described.

  Patent Document 3 (Japanese Patent Application Laid-Open No. 2008-94458) discloses an invention of a film roll having an adhesive band (adhesive article) for facilitating the operation when it is first removed from the storage box. However, there is no description about the adhesive strength and the like of the adhesive band, and it does not refer to problems such as tearing of the container at the time of peeling and adhesive residue as in the cited document 2.

  Patent Document 4 (Japanese Patent No. 2763630) discloses an invention of a method and an apparatus for mounting an adhesive tape having a folded end. This document describes a method for folding back an adhesive tape, but it does not describe any suitable adhesive strength between the folded adhesive surfaces or the type of adhesive used for the tape. Absent.

  Furthermore, since none of Patent Documents 1 to 4 mentions the specific composition of the pressure-sensitive adhesive, the pressure-sensitive adhesive tape disclosed in these documents meets the standards of the Food Sanitation Law by any method. It is not clear whether it has reached or has not been reached.

JP 2014-34400 A JP 2007-145430 A JP 2008-94458 A Japanese Patent No. 2763630

  An object of the present invention is to provide a pressure-sensitive adhesive article that has a suitable pressure-sensitive adhesive force on containers, the pressure-sensitive adhesive force does not increase with time, can ensure adhesion between pressure-sensitive adhesive surfaces, and is also compatible with the Food Sanitation Law. There is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have arrived at the present invention by providing a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition satisfying predetermined requirements on one side of a substrate.

  That is, the present invention is a pressure-sensitive adhesive article comprising a base material provided with a pressure-sensitive adhesive layer mainly composed of synthetic rubber, and the pressure-sensitive adhesive layer has a tackifying resin amount of 100 parts by weight of the synthetic rubber. It is related with the adhesive article characterized by consisting of an adhesive composition which is 60 mass parts or less.

Since the pressure-sensitive adhesive article of the present invention has an appropriate pressure-sensitive adhesive force with respect to containers, no adhesive remains on the containers, and the containers (thin films such as bags) are not stretched or torn. Moreover, the adhesive force of the adhesive article is too low, and there is no problem that the adhesive article is peeled off from the containers when the customer uses it. In addition, since the pressure-sensitive adhesive article of the present invention has a suitable peelability for containers, while the pressure-sensitive adhesive surfaces are highly bonded to each other, for example, a suitable length of the tip is set to a folded end (grip allowance). can do.
Furthermore, since the adhesive article of the present invention conforms to the Food Sanitation Law (Ministry of Health and Welfare Notification No. 370 of 1959), the inclusion of harmful substances due to the adhesive is restricted, which may adversely affect the human body. There is no.

[Adhesive composition]
The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive article of the present invention is a composition containing synthetic rubber as a main component and containing tackifying resin in an amount of 60 parts by mass or less with respect to 100 parts by mass of the synthetic rubber. .
Specific examples of synthetic rubber include isoprene rubber, styrene butadiene rubber, butyl rubber, polyisobutylene rubber, acrylic rubber, silicone rubber, urethane rubber, nitrile rubber, and modified products thereof. From the viewpoint or from the viewpoint of having tack even when the content of the tackifying resin is small, butyl rubber, polyisobutylene rubber, polybutylene rubber (polybutene rubber) and polyisoprene rubber are preferable.
These may be used alone or in combination of two or more.
By using synthetic rubber as a main component, an effect of suppressing adhesiveness with containers as compared with a conventional acrylic pressure-sensitive adhesive can be obtained.

In the pressure-sensitive adhesive composition of the present invention, at least a tackifying resin is contained in an amount of 60 parts by mass or less, preferably 50 parts by mass or less, and 40 parts by mass with respect to 100 parts by mass of the rubber component. It is more desirable to be contained in an amount of not more than%, and it is particularly preferred that it is contained in an amount of not more than 20 parts by mass. When the addition amount of the tackifying resin exceeds 60 parts by mass, there is a concern about adhesive residue or tearing (in the case of a bag or the like) on the containers when the adhesive article is peeled off.
On the other hand, if the amount of tackifying resin is increased unnecessarily, there is a possibility that the food hygiene law may not be met.
Further, since the desired characteristics are often obtained by the tackiness and self-adhesiveness of the rubber itself, the tackifying resin is not necessarily an essential component, but the tackifying resin is 1 part by mass with respect to 100 parts by mass of the rubber component. It is preferably contained within the above range, and more preferably 3 parts by mass or more. If it is 3 parts by mass or more, a desired adhesive force can be imparted to the adhesive layer even for containers that are relatively difficult to adhere.

  Types of tackifying resins include aliphatic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, alicyclic petroleum resins, coumarone / indene resins, polymer resins such as pure monomer resins, phenol There are condensate resins such as xylene resins and xylene resins, and one or more of these can be used in combination.

  The pressure-sensitive adhesive composition according to the present invention is a softener containing a mineral oil such as paraffinic process oil, vegetable oil or the like, or an aromatic secondary amine within the limits that do not affect predetermined standards such as the Food Sanitation Act. You may contain 1 type or 2 types or more in combination of anti-aging agents, such as a type | system | group, a monophenol type | system | group, a bisphenol type | system | group, a polyphenol type | system | group, a benzimidazole type | system | group, and a phosphorous acid type | system | group. Adhesion can be improved by using a softener, and oxidative deterioration of the adhesive can be prevented by an anti-aging agent. Further, for the purpose of adjusting the adhesive strength, fillers such as silica, alumina, clay and metal hydroxide may be used alone or in combination of two or more.

  The pressure-sensitive adhesive composition is an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate, a reactive phenol resin, a sulfur compound, a maleimide compound, etc., within the limits that do not affect predetermined standards such as the Food Sanitation Act. It is also possible to use after crosslinking with a crosslinking agent. The use by crosslinking can improve the peelability from the containers, but the use thereof is arbitrary and not limited.

  The pressure-sensitive adhesive article according to the present invention has a structure having a pressure-sensitive adhesive layer made of the above pressure-sensitive adhesive composition on one side of a substrate.

  The thickness of the pressure-sensitive adhesive layer is not particularly limited and may be appropriately determined within a range where no adhesive residue or the like occurs. However, in consideration of pressure-sensitive adhesive properties and economy, it is usually 1 to 50 μm, preferably 3 to 30 μm. Preferably it is 5-20 micrometers.

[Base material]
The substrate used in the present invention is not particularly limited, but may be a single layer substrate composed of one member, or a substrate composed of a laminate having a laminated structure in which one member and another member are bonded together. There may be. The base material may have flexibility, or may have resilience, and its properties may be appropriately selected from the convenience of the consumer such as handling properties.

  The member constituting the substrate is preferably a resin film, nonwoven fabric or paper, and more preferably a resin film. When the substrate is a laminate, the member is preferably one or more members selected from the group consisting of a resin film, a nonwoven fabric and paper, and at least one layer is a resin film. More preferred.

  Specific examples of the resin film include films of polypropylene, polyethylene, polyethylene terephthalate (PET), polybutylene terephthalate, and the like. Two or more resin films may be used in combination. Among these, a polypropylene film is preferable.

  The substrate may be subjected to corona treatment, primer treatment or the like in order to improve the adhesion with the pressure-sensitive adhesive layer. This is because when these treatments are performed, adhesive residue on the containers can be prevented when the adhesive article is peeled off from the containers.

Although the thickness of a base material should just be selected suitably in consideration of the handleability by a consumer, etc., generally it is 2-100 micrometers. Preferably it is 3-30 micrometers, More preferably, it is 5-20 micrometers.
The thickness of the pressure-sensitive adhesive article including the base material and the pressure-sensitive adhesive layer may be appropriately selected in consideration of the handleability of the consumer and the like, but is generally 3 to 150 μm. Preferably it is 6-100 micrometers, More preferably, it is 10-80 micrometers.

The pressure-sensitive adhesive layer can be formed by coating the pressure-sensitive adhesive composition on one side of the substrate. The coating method of the pressure-sensitive adhesive composition is not particularly limited, but in the case of a pressure-sensitive adhesive composition containing a solvent, for example, the pressure-sensitive adhesive composition is applied to the substrate surface with a roll coater or a reverse coater. The pressure-sensitive adhesive article of the present invention is obtained by coating and heating to volatilize the solvent. In the case of a pressure-sensitive adhesive composition that does not use an organic solvent such as a solid pressure-sensitive adhesive, the pressure-sensitive adhesive composition is extruded on a substrate using a T-die type extruder or a calender roll. The adhesive article of the present invention is obtained.
The dimensions of the pressure-sensitive adhesive article may be appropriately selected in consideration of the handleability by the consumer, etc. In general, the length / width of one piece is preferably 10 to 100 mm. Further, depending on the application, as shown in the background art, it is preferable to provide a folded end portion so as to be easily grasped. The folded end is appropriately set in consideration of picking with a finger, and is usually 5 to 25 mm, preferably about 10 to 20 mm.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these. “Parts” and “%” indicate “parts by mass” and “% by mass” unless otherwise specified.

[Preparation of pressure-sensitive adhesive composition]
The following components were mixed in the amounts (parts by mass) shown in Table 1 to obtain pressure-sensitive adhesive compositions used in Examples 1 to 5 (Formulations 1 to 5).

[Comparative Example 1]
Polymerize 97 parts of 2-ethylhexyl acrylate, 2.5 parts of acrylic acid and 0.5 part of 2-hydroxyethyl acrylate in a solvent using 2,2′-azobis (isobutyronitrile) as an initiator, and a solid content of 50%. An acrylic polymer was obtained. A pressure-sensitive adhesive composition was obtained by adding 100 parts of this acrylic polymer as a base polymer and 1 part of an isocyanate curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.).

[Comparative Example 2]
20 parts of butyl acrylate, 77 parts of 2-ethylhexyl acrylate, 2.5 parts of acrylic acid and 0.5 part of 2-hydroxyethyl acrylate were polymerized in a solvent using 2,2′-azobis (isobutyronitrile) as an initiator. An acrylic polymer having a solid content of 50% was obtained. By adding 100 parts of this acrylic polymer as a base polymer and 1 part of an isocyanate curing agent (trade name L-45, manufactured by Soken Chemical Co., Ltd.), an adhesive composition was obtained.

[Comparative Example 3]
A pressure-sensitive adhesive composition was obtained by dissolving 100 parts of styrene isoprene block polymer (trade name Quintac 3433N, manufactured by Nippon Zeon Co., Ltd.) in toluene.

[Comparative Example 4]
By adding 0.5 parts of platinum catalyst (trade name SRX212P, manufactured by Toray Dow Corning Co., Ltd.) to 100 parts of addition reaction type silicone rubber (trade name SRX211 manufactured by Toray Dow Corning Co., Ltd.) An agent composition was obtained.

[Applying adhesive to base material (manufacture of adhesive products)]
A polypropylene film (Trefan (registered trademark), thickness: 60 μm) manufactured by Toray Film Processing Co., Ltd. was used as the substrate.
An adhesive article was obtained by forming an adhesive layer on the anchor-treated surface of the substrate. Specifically, the pressure-sensitive adhesive compositions described in Examples and Comparative Examples were diluted with toluene so as to have a solid content of 20%, applied to one side of the substrate with a roll coater, and then heated at 80 ° C. for 2 minutes. Then, an adhesive layer was formed by volatilizing toluene.
[Evaluation methods]

(Measurement of adhesive strength)
For the adherend, containers (containers 1 to 5) described later were fixed to a stainless steel plate with a double-sided tape (No. 7641 manufactured by Teraoka Seisakusho Co., Ltd.).
Using a sample with a width of 10 mm of an adhesive article, a peel adhesion test is performed on the container surface in accordance with JIS Z 0237 (2000) at a peeling angle of 180 °, a curing time of 20 minutes after pressure bonding, and a peeling speed of 300 mm / min. did. The results are shown in Table 2.
Evaluation was performed based on the following criteria.
“◯”: Adhesive strength is 0.1 N / 10 mm or more, and there is no concern about peeling from containers.
“X”: Adhesive strength is less than 0.1 N / 10 mm, and there is concern about peeling from containers.

(Adhesive residue test on containers)
In the adhesive strength measurement test described above, the presence or absence of adhesive residue on the container surface was visually observed. Evaluation was performed based on the following criteria. The results are shown in Table 2.
“◯”: No adhesive residue was generated on the container surface.
"X": The adhesive residue on the container surface occurred.

(Observation of container breakage)
In the above-mentioned adhesive strength measurement test, it was visually observed whether or not the containers were pulled on the adhesive surface to cause tearing. Evaluation was performed based on the following criteria. The results are shown in Table 2.
“◯”: Containers were not torn.
“X”: Containers were torn.

(Return test)
A test piece was prepared by preparing an adhesive article (width 10 mm, length 50 mm), folding the end in the length direction 5 mm, and bonding the adhesive surfaces together.
The test piece was left in a thermostatic bath set to an atmospheric temperature of 70 ° C. for 2 hours, and the presence / absence of the end portion was visually observed. The results are shown in Table 3.
Evaluation was performed based on the following criteria.
“◯”: No edge curl occurred.
“×”: Edge curling occurred.

(Food Sanitation Act)
Regarding the suitability of the Food Sanitation Law, the standards for foods, additives, etc. (Ministry of Health and Welfare Notification No. 370 of 3959) 3 D 2 Synthetic resin equipment or container packaging (category: operating temperature 100 ° C or less) Based on the test, the entire tape sample was tested.
In the general standards (material test: cadmium, lead, elution test (heavy metal, potassium permanganate consumption)), those that are within the limits set by the standard are considered “conformity”, and those that are within the limits are “ The results are shown in Table 2.

* Numerical value of adhesive strength (unit: N / 10mm)
Container 1: Saran Wrap (registered trademark, manufactured by Asahi Kasei, polyvinylidene chloride)
Container 2: Polywrap (registered trademark, made by Ube Film, polyethylene)
Container 3: Riken wrap (registered trademark, manufactured by Riken Fabro, polyvinyl chloride)
Container 4: Four Wrap (registered trademark, manufactured by Riken Technos, polymethylpentene)
Container 5: View wrap (registered trademark, manufactured by Hitachi Chemical, polyolefin laminated)
Container 6: Ziploc freezer bag (registered trademark, manufactured by Asahi Kasei Home Products, polyethylene)
Container 7: Tapper (registered trademark, manufactured by Tupperware, polypropylene)

As is apparent from Table 2, since the adhesive article of the present invention has an appropriate adhesive strength to containers, no adhesive residue is generated on the containers, and the containers (thin films such as bags) are stretched. There is no tearing. Moreover, since the adhesive strength of the adhesive article is too low, there is no problem that the adhesive article easily peels off when the customer handles it.
In addition, since the adhesive article of the present invention conforms to the Food Sanitation Law (Ministry of Health and Welfare Notification No. 370 of 1959), the content of harmful substances due to the adhesive is limited, which may adversely affect the human body. Absent.

While the pressure-sensitive adhesive article of the present invention has an appropriate peelability for containers, as is apparent from Table 3, the pressure-sensitive adhesive surfaces are highly bonded to each other. It can be a folded end (grip allowance).
Therefore, the pressure-sensitive adhesive article of the present invention can easily peel off the pressure-sensitive adhesive article that has completed the function of display or the like.

  The adhesive article of the present invention can be used as an adhesive tape or an adhesive label to be affixed to containers, for example, its self-adhesive strength (adhesive strength between adhesive surfaces), a suitable range of adhesive strength, conformity to the Food Sanitation Law, etc. If it pays attention to the characteristic of this, it is useful also for the use as a tape for vegetable binding.

Claims (5)

  A pressure-sensitive adhesive article comprising a base material and a pressure-sensitive adhesive layer comprising synthetic rubber as a main component, wherein the pressure-sensitive adhesive layer has an amount of tackifying resin of 100 parts by mass or less of synthetic rubber. A pressure-sensitive adhesive article comprising a pressure-sensitive adhesive composition.   The pressure-sensitive adhesive article according to claim 1, wherein the synthetic rubber is at least one selected from butyl rubber, polyisobutylene rubber, polybutylene rubber (polybutene rubber), and polyisoprene rubber.   The pressure-sensitive adhesive article according to claim 1 or 2, wherein the tackifying resin is a hydrogenated petroleum resin or a hydrogenated terpene resin.   The adhesive article according to any one of claims 1 to 3, which conforms to the Food Sanitation Law (Ministry of Health and Welfare Notification No. 370 of 1959).   The pressure-sensitive adhesive article according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 50 µm.