JP2018177998A - Re-peelable surface protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film that has excellent wet spread, can be pasted without causing wrinkling and bubbling in an object, and prevents whitening.SOLUTION: A re-peelable surface protective film has a base film, and an adhesive layer disposed on the base film. The base film is mainly composed of a vinylidene chloride copolymer. The adhesive layer is mainly composed of a polyurethane adhesive.SELECTED DRAWING: None

Description

  The present invention relates to a releasable surface protective film.

The surface protective film is used to protect various objects in order to protect the surface from dust, dirt, stains and scratches.
For example, when forming an integrated circuit on a green sheet, there is a surface protection film for a green sheet which can be laminated or peeled to prevent the green sheet from being contaminated with impurities such as dust, dirt, oil droplets and the like (patented) Reference 1).
In addition, in order to protect optical members such as polarizing plates and wavelength plates, manufacturing processes of surface protection films having antistatic properties, optical components such as liquid crystal displays such as personal computers, televisions and mobile phones, touch panels, etc. There is a surface protection film which protects the surface from dirt and scratches at the time of package transportation and use (see, for example, Patent Documents 2 and 3).

  Furthermore, in the medical field, since a personal computer for viewing electronic medical records etc. and medical devices are shared by a plurality of medical personnel, there is a concern about cross-infection and maintenance of sanitation is required, for example, In Document 4, a keyboard cover molded of a resin containing an antibacterial agent is proposed.

JP H9-316411 JP 2005-314476 A JP, 2015-7226, A Unexamined-Japanese-Patent No. 2006-330954

A personal computer or medical device has a keyboard, a switch, an operation panel, etc., and there are corners and irregularities. When protecting the surface with films, the corners and irregularities are present. Also, it is required to be easy to stick, that is, to have wet spreadability and to be less prone to wrinkles. Moreover, when covering a surface with a film, it is calculated | required that a bubble can not be performed.
If the wetting and spreading properties are insufficient or wrinkles or bubbles are present, the operability of the personal computer or the medical device is deteriorated, and the smooth operation can not be performed.
In addition, when a personal computer or medical device is covered with a surface protection film, the personal computer or equipment is operated through the film, so the surface protection film changes color etc so that the object can be checked from the film. It is required to be kept transparent.

The film for surface protection for green sheets described in the cited document 1 has a pressure-sensitive adhesive layer including one obtained by crosslinking an acrylic copolymer on one side of a biaxially stretched polyvinylidene chloride resin film.
In the surface protection film described in Patent Document 2, a pressure-sensitive adhesive layer formed by crosslinking a pressure-sensitive adhesive composition containing a (meth) acrylic monomer is formed on a support made of a plastic base material subjected to antistatic treatment. There is.
The film for surface protection described in Patent Document 3 has a plastic film substrate on which a pressure-sensitive adhesive layer of a removable polyurethane pressure-sensitive adhesive composition containing a polyurethane resin is formed.
However, any of the films for surface protection described in the cited references 1 to 3 is used to prevent an object to be covered by the film from being scratched or soiled, and is covered by the film. It is not premised to operate the above-mentioned object from the top of the film, and the operability of the object covered with the film is not excellent.

  Then, an object of the present invention is to provide a film which is excellent in wet spreading property, can be stuck without generating wrinkles and bubbles on an object, and is hard to cause whitening.

  The inventors of the present invention conducted intensive studies to find that a film having a base film containing a specific polymer and an adhesive layer containing a specific adhesive disposed on the base film is an object. It has been found that when pasted, it is excellent in wet spreading, does not generate wrinkles and bubbles, whitening hardly occurs, and transparency of the film is maintained, and the present invention has been completed.

  That is, the present invention is as follows.

[1]
A substrate film,
An adhesive layer disposed on the substrate film;
A releasable surface protection film having
The substrate film contains a vinylidene chloride copolymer as a main component,
The adhesive layer contains a polyurethane adhesive as a main component,
Removable surface protection film.
[2]
The removable surface protective film as described in [1] whose adhesive force of the said adhesive film is 0.03-0.30 N / 25 mm.
[3]
The thickness of the substrate film is 10 to 30 μm,
2% strain elastic modulus in the flow direction (MD direction) and 2% strain elastic modulus in the width direction (TD direction) are respectively 190 to 400 MPa, and
Tensile elongation in the flow direction (MD direction) and width direction (TD direction) satisfy 80 to 150%, respectively
The removable surface protection film as described in [1] or [2].
[4]
40 to 80% of the epoxidized vegetable oil contained in the removable surface protective film and 40 to 80% of fatty acid glycerin ester are contained in the adhesive layer according to any of [1] to [3] Removable surface protection film.
[5]
The removable surface protective film according to any one of [1] to [4], wherein the thickness of the adhesive layer is 1.0 to 30 μm.
[6]
The removable surface protective film according to any one of [1] to [5], wherein the polyurethane adhesive contains, as a main agent, a polyurethane having a hydroxyl group and, as a curing agent, an aliphatic diisocyanate.
[7]
A releasable surface protective film wound body comprising: a cylindrical core; and the releasable surface protective film according to any one of [1] to [6] wound around the core.
[8]
The removable surface protective film according to any one of [1] to [6], which is used to protect a medical device.

  The releasable surface protective film of the present invention is excellent in wet spreading property when stuck to an object, and generation of wrinkles and bubbles is suppressed. In addition, the releasable surface protective film of the present invention is less susceptible to whitening, and the transparency of the film is maintained. Therefore, cross protection can be prevented in the use environment where a plurality of medical personnel indirectly contact, especially when used for protecting personal computers and medical devices at medical sites, and it is possible to prevent personal computers and medical devices from above films. You can do

It is the schematic which shows the releasable surface protective film of this embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The following present embodiment is an example for describing the present invention, and is not intended to limit the present invention only to this present embodiment. And this invention can be deform | transformed suitably and implemented within the range of the summary.

<Removable surface protective film>
The removable surface protection film of the present embodiment has a base film and an adhesive layer disposed on the base film. Moreover, the said base film contains a vinylidene chloride copolymer as a main component, and the said adhesion layer contains a polyurethane adhesive as a main component.
The removability means the property which can be peeled off once the film is attached to the object. Moreover, removability originates in the adhesive layer in this embodiment.

(Base film)
The base film in the present embodiment contains a vinylidene chloride copolymer as a main component.
The base film in the present embodiment contains 75 parts by mass of vinylidene chloride monomer units and 100 parts by mass of a vinylidene chloride copolymer having a weight average molecular weight of 7 × 10 ^{4 to} 14 × 10 ⁴ g / mol. And 1 to 20 parts by mass of a mixture of a fatty acid ester and an epoxidized compound. The amount of the mixture of fatty acid ester and epoxidized compound is more preferably 1 to 15 parts by mass, and further preferably 1 to 10 parts by mass with respect to 100 parts by mass of the vinylidene chloride copolymer.
Moreover, although the base film in this embodiment may contain resin other than a vinylidene chloride copolymer, as resin contained in a base film, it is preferable to consist of a vinylidene chloride copolymer.

  The thickness of the substrate film in the present embodiment is preferably 5 to 45 μm, more preferably 10 to 30 μm, from the viewpoint of wettability and spread, operability of a personal computer or a medical device, and durability. Preferably it is 15-30 micrometers.

Further, the base film in the present embodiment has a 2% strain elastic modulus in the flow direction (MD direction) and a 2% strain elastic modulus in the width direction (TD direction) of 190 to 400 MPa, respectively, and The tensile elongations in the (MD direction) and in the width direction (TD direction) preferably satisfy 80 to 150%, respectively.
In the removable surface protective film of the present embodiment, when the 2% strain elastic modulus of the base film is 190 to 400 MPa, the film is unlikely to be stretched and tends not to be broken.
In the releasable surface protective film of the present embodiment, when the tensile elongation of the base film is 80 to 150%, the film is unlikely to be stretched and tends not to be broken.

In the base film used in the present embodiment, the 2% strain elastic modulus in the flow direction (MD direction) is more preferably 190 to 350 MPa, and still more preferably 200 to 300 MPa.
In the base film used in the present embodiment, the 2% strain elastic modulus in the width direction (TD direction) is more preferably 190 to 350 MPa, and still more preferably 190 to 300 MPa.

Furthermore, as for the base film used for this embodiment, it is more preferable that the tensile elongation of a flow direction (MD direction) is 90 to 140%, and it is further more preferable that it is 90 to 130%.
Furthermore, in the base film used in the present embodiment, the tensile elongation in the width direction (TD direction) is more preferably 80 to 140%, and still more preferably 90 to 130%.

  When a base film having such properties is used, for example, when used as a keyboard cover, the releasable surface protective film tends to be less likely to stretch and more likely to break the film, even if repeated key touches are made. Moreover, since it is hard to extend | stretch also at the corner | angular part of various apparatuses similarly, it is hard to tear and it can use for protection of an apparatus. The various devices include, for example, all corner parts such as multifunction machines in the office, cashiers at retail stores, weighing machines at the backyard, switches and operation panels of inspection equipment such as MRIs and CTs at hospitals, electronic medical record wagons, stretchers, etc. The equipment which it has is mentioned.

  The method for controlling the 2% strain elastic modulus and the tensile elongation of the substrate film in the above range is not particularly limited. For example, the step of extruding a resin and a plasticizer from an annular die as a single layer or multilayer raw fabric, and extrusion A method can be mentioned which comprises a step of cooling and solidifying the obtained raw fabric and a step of stretching the cooled and solidified raw fabric.

  Furthermore, the base film is preferably stretched. The stretching treatment step is a known step of uniaxially or biaxially stretching a raw film material. The stretching method is not limited, and preferably biaxial stretching, more preferably sequential or simultaneous biaxial stretching method or inflation biaxial stretching method can be employed, and among these, inflation biaxial stretching method is preferable.

  In addition, in this embodiment, 2% strain elastic modulus and tensile elongation of a base film can be measured by the method as described in the below-mentioned Example.

(Adhesive layer)
The pressure-sensitive adhesive layer in the present embodiment is a layer that contains a polyurethane pressure-sensitive adhesive as a main component, and is formed of such a polyurethane pressure-sensitive adhesive.
The main component of the adhesive layer in the present embodiment means a component of 70% by mass or more, preferably 100% by mass or more, more preferably 85% by mass or more, and more preferably 90% by mass, based on 100% by mass of all components. % By mass or more, more preferably 100% by mass.

  The polyurethane adhesive is not particularly limited as long as it contains a polyurethane and a curing agent. In addition, the polyurethane pressure-sensitive adhesive includes, as other additives, coupling agents, plasticizers, tackifiers such as terpenes and rosins, inorganic fillers such as calcium carbonate and titanium oxide, antioxidants, ultraviolet absorbers, etc. And the like may be included.

  The polyurethane is not particularly limited as long as it is a polymer having a urethane bond, and, for example, polyurethane having a hydroxyl group can be suitably mentioned. As a polyurethane which has a hydroxyl group, the polymer of an isocyanate compound and a polyol can be mentioned specifically ,.

  As the isocyanate compound, for example, aromatic polyisocyanates such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, triphenylmethane triisocyanate, polyphenyl polymethylene polyisocyanate, etc .; hexamethylene diisocyanate, Aliphatic or alicyclic polyisocyanates such as lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate; polyisocyanates having a carbodiimide group; polyisocyanates having an allophanate group; isocyanurate group Polyisocyanate having Etc. The. These may be used alone or in combination of two or more.

  Examples of polyols include polyether polyols, polyester polyols, polyether ester polyols and the like. These may be used alone or in combination of two or more.

As a polyester polyol, what is obtained by making a polycarboxylic acid and a polyol react can be used.
Examples of polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and aromas such as o-phthalic acid. Family polycarboxylic acids can be used.
Examples of polyols that can be used to produce polyester polyols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethyl 1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexane-1,4-diol And cyclohexane-1,4-dimethanol can be used.
Moreover, as said polyester polyol, ring-opening polymers, such as (gamma) -butyrolactone and (epsilon) -caprolactone, poly (hexamethylene carbonate) diol, etc. can also be used.

  Examples of polyether polyols include those obtained by ring-opening polymerization of ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran or the like using the above-described polyol or polyamine as an initiator.

  As polyester ether polyol, the copolymer etc. of polyester polyol and polyether polyol which were mentioned above are mentioned, for example.

Moreover, as a polyol used for manufacture of the polyurethane which has a hydroxyl group, the low molecular weight polyol of 60-140 molecular weight can also be used.
Examples of low molecular weight polyols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,2-dimethyl-1,3- Propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, Examples include cyclohexane-1,4-dimethanol, glycerin, trimethylolpropane, trimethylolethane, hexanetriol, pentaerythritol, sorbitol, methyl glycoside and the like.

The polyurethane having a hydroxyl group may be a polyurethane produced by using an amine compound as a chain extender in addition to the above-mentioned polyol compound.
Examples of the amine compound include diamines such as ethylene diamine, hexamethylene diamine and piperazine; amino alcohols such as monoethanolamine and diethanolamine; and the like.

  A commercial item can be used as a polyurethane which has a hydroxyl group, As a commercial item, Toyo Chem SH-101 etc. are mentioned, for example.

Examples of the curing agent include aromatic diisocyanates such as diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), xylene diisocyanate (XDI), and aliphatic diisocyanates such as hexamethylene diisocyanate (HDI). . These may be used alone or in combination of two or more.
Among the above-mentioned curing agents, aliphatic diisocyanates are preferred.
A commercial item can be used as a hardening agent, As a commercial item, Toyo Chem T501B etc. are mentioned, for example.

The above-mentioned polyurethane adhesive preferably contains 0.1 to 10% by mass, more preferably 2.0 to 8.0% by mass, still more preferably 4.0 to 10% by mass of the curing agent based on the mass of the polyurethane adhesive. 6.0 mass% is included.
By setting the amount of the curing agent to 0.1% by mass or more, curing tends to be appropriately progressed and adhesive residue does not occur at the time of use. Further, by setting the amount of the curing agent to 10% by mass or less, the target adhesive performance can be obtained.

  When having the adhesive layer formed of the adhesive as described above, the releasable surface protective film of the embodiment adheres firmly to the medical device when used as a cover of the medical device, for example, and is peeled off. The effect of easy peeling off is expressed. In addition, the film is easy to handle without being entangled.

The thickness of the adhesive layer in the present embodiment is preferably 0.5 to 40 μm, more preferably 1.0 to 30 μm, and 3.0 to 25 μm from the viewpoint of the adhesive force of the adhesive layer. Is more preferably 5.0 to 25 μm.
When the thickness of the adhesive layer is in the above range, for example, when used as a cover of a medical device, the retouchable surface protective film of the present embodiment is firmly stuck to the medical device and easily peeled off when peeled off. The effect is more pronounced. In addition, the film becomes easier to handle without being entangled.
Moreover, the quantity of the epoxidized vegetable oil and fatty-acid glycerol ester contained in an adhesion layer can be controlled by making thickness of the adhesion layer in this embodiment into said range.

  The removable surface protection film of the present embodiment includes a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive force (180-degree peel force in accordance with JIS 0237) is preferably 0.01 to 0.40 N / 25 mm. The adhesion is more preferably 0.02 to 0.30 N / 25 mm, still more preferably 0.03 to 0.30 N / 25 mm. When the removable surface protection film includes an adhesive layer having an adhesive strength of 0.01 to 0.40 N / 25 mm, for example, when used as a cover of a medical device, it firmly adheres to the medical device and is peeled off It has the effect of easily peeling off. In addition, when the above-mentioned base film is subjected to slight adhesion processing with the above-mentioned adhesive layer, it becomes easy to handle the films without sticking when sticking the films. Furthermore, there exists a tendency which can suppress generation | occurrence | production of wrinkles and a bubble at the time of affixing by including the adhesion layer which has the adhesive force of 0.01-0.40 N / 25 mm of a releasable surface protection film.

  The method for controlling the adhesive strength of the adhesive layer to the above range is not particularly limited. For example, the method of adjusting the hardness of the adhesive or the thickness of the adhesive layer, adjusting epoxidized vegetable oil and fatty acid glycerol ester contained in the adhesive layer And the like.

  In the present embodiment, the adhesive force of the adhesive layer is the 180 degree peel force obtained by the measurement method in accordance with JIS 0237. Moreover, the adhesive force of an adhesive layer can be specifically measured by the method as described in an Example.

The adhesive layer in this embodiment preferably contains 40 to 80% of the epoxidized vegetable oil contained in the removable surface protection film and 40 to 80% of the fatty acid glycerin ester.
The ratio of the epoxidized vegetable oil and fatty acid glycerin ester in the adhesive layer is more preferably 40 to 70%, and still more preferably 40 to 60%.
When the upper limit value of the epoxidized vegetable oil and fatty acid glycerin ester is 80%, the adhesive layer has sufficient adhesive strength, for example, when used as a cover of a medical device, firmly adheres to the medical device Can.
By setting the lower limit value of the epoxidized vegetable oil and the fatty acid glycerol ester to 40%, it is possible to maintain appropriate stiffness of the base film.

  The method for controlling the amounts of the epoxidized vegetable oil and fatty acid glycerin ester in the adhesive layer is not particularly limited, but, for example, the method of adjusting the hardness of the adhesive or the thickness of the adhesive layer, and the amount of curing agent are adjusted. Methods etc.

  The amounts of epoxidized vegetable oil and fatty acid glycerin ester in the adhesive layer can be specifically measured by the method described in the examples.

(Release layer)
The removable surface protection film of the present embodiment may further include a release layer on the back surface of the substrate film (the surface on which the adhesive layer is not laminated). When the releasable surface protective film of the present embodiment includes a release layer, when the releasable surface protective film is used as a wound body, it tends to be easy to unroll.
Although the release layer is not particularly limited, for example, a silicone type or long chain alkyl pendant polymer type can be used.
The thickness of the release layer is preferably 0.1 to 1.0 μm, more preferably 0.15 to 0.9 μm, and still more preferably 0.2 to 0.7 μm.
Furthermore, in the removable surface protection film of the present embodiment, a print layer or a primer layer may be provided between the base film and the adhesive layer.

(separator)
The removable surface protection film of the present embodiment may further have a separator on the adhesive layer side of the layer including the base film and the adhesive layer, that is, on the adhesive layer. Although the separator is not particularly limited, for example, a polyethylene terephthalate (PET) film, paper or the like which has developed releasability by silicone treatment can be used.

One aspect of the releasable surface protective film of the present embodiment is shown as a schematic diagram in FIG.
Specifically, as shown in FIG. 1, the removable surface protection film of the present embodiment is represented by 1 of the surface protection film,
Base film 2, adhesive layer 3, release layer 4 and separator 5;
The adhesive layer 3 is laminated on the first surface of the base film 2, and the release layer 4 is laminated on the second surface,
The separator 5 is stacked on the adhesive layer 3.

<Method of Manufacturing Releasable Surface Protective Film>
The manufacturing method of the releasable surface protective film of the present embodiment is not particularly limited as long as it is a method capable of laminating an adhesive layer on a base film. The base film in the present embodiment is, for example, a step of extruding a resin and a plasticizer as a single layer or multilayer raw fabric from an annular die, a step of cooling and solidifying the extruded raw fabric, and cooling and solidification It can manufacture by the method including the process of extending | stretching a raw material.

  The stretching treatment step is a known step of uniaxially or biaxially stretching a raw film material. The stretching method is not limited, and preferably biaxial stretching, more preferably sequential or simultaneous biaxial stretching method or inflation biaxial stretching method can be employed, and among these, inflation biaxial stretching method is preferable.

  The releasable surface protective film of the present embodiment is obtained, for example, by applying an adhesive to the base film obtained as described above with a comma coater or a gravure coater, drying it, winding it, and aging it at 40 ° C. for 2 days. You can get it. At that time, a method may be used in which a base film is laminated after applying and drying an adhesive on a separator. Before applying the pressure-sensitive adhesive, a primer having an affinity to the pressure-sensitive adhesive layer and the substrate layer may be applied in advance, or the substrate film may be subjected to a corona treatment. Moreover, you may perform the back surface processing to a base material in the process before and behind adhesive coating.

<Repeatable surface protective film winding body>
The releasable surface protective film of the present embodiment may be a releasable surface protective film wound body, and the film wound body includes a core tube and the above-described releasable surface wound around the core tube. And a protective film.

  There is no limitation on the material of the core tube, and for example, one made of paper, plastic, metal or the like can be used. The core tube may be a hollow cylinder inside or a hollow cylinder not hollow. Moreover, there is no limitation in the diameter of a core tube, For example, it can be 10 mm-50 mm.

  In the releasable surface protective film winding body of the present embodiment, the pulling power for pulling out the releasable surface protective film from the core tube is preferably 30 to 300 cN / 200 mm wide, 35 to 200 cN / 200 mm wide. The width is more preferably 40 to 100 cN / 200 mm. By setting the pulling power to the above-mentioned range, it is possible to pull out the necessary amount of releasable surface protective film with a light force.

  The method of controlling the pulling power to pull out the releasable surface protective film from the core tube to the above range is not particularly limited. For example, in addition to the setting of the adhesive force of the releasable surface protective film, releasable surface protection The method of providing a mold release layer on the back of a film is mentioned.

  In addition, in this embodiment, the pulling output which pulls out a removable surface protection film from a core pipe can be measured by the method as described in the below-mentioned Example.

<Removable surface protective film storage box>
The releasable surface protective film roll may be stored in a box (hereinafter, also referred to as a "removable surface protective film storage box").
The releasable surface protective film storage box comprises means for pulling the releasable surface protective film from the core tube. A necessary amount of film can be pulled out by providing a takeout port for drawing out the releasable surface protective film roll and by a structure in which the roll can freely rotate in the storage box.
Furthermore, the releasable surface protective film storage box can be provided with means for cutting the releasable surface protective film drawn from the core tube. This makes it possible to easily cut the required amount of releasable surface protection film pulled out. As a cutting means, a slide cutter may be used in addition to a metal, paper, plastic, etc. saw blade.

<Applications of releasable surface protection film>
The removable surface protection film of this embodiment can be used to protect a medical device. Here, the target object such as a medical device is, for example, a switch or operation panel of an inspection device such as MRI or CT at a medical institution such as a hospital, an examination table, an electronic medical record wagon, a stretcher, a personal computer, an office Examples include copiers, devices used in medical institutions, appliances, fixtures, furniture, office furniture. In addition to medical institutions, for example, cash register of retail store, weighing machine of backyard and food processing plant, equipment such as filling machine and work table, moving carriage, building materials surface and electronic equipment of construction site, construction machine It can be used without limitation for applications other than medical institutions, such as control panels.

  EXAMPLES Next, the present invention will be more specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

  Each measuring method used by the Example and the comparative example was as follows.

(1) 2% Strain Modulus of Substrate Film Measured according to ASTM-D882. That is, the substrate film of each example was cut out into a width of 10 mm and a length of 100 mm along the MD and TD directions to obtain a sample, and the measurement was performed at a tensile speed of 5 mm / min. A tangent line is drawn on the obtained stress-strain graph, a value obtained by converting the stress value at 2% elongation to the thickness of the sample is calculated, and the average value of five measurements is taken as the measured value. The average value of is taken as the value of 2% strain elastic modulus. As a measuring device, AUTOGRAPH AG-IS manufactured by Shimadzu Corporation was used.

(2) Tensile Elongation of Base Film Measured according to ASTM-D882. That is, the base film of each example is cut out into a width of 10 mm and a length of 100 mm along the MD and TD directions to make a sample, and measurement is performed at a tensile speed of 300 mm / min. The average value of the measurement in each time was taken as the measured value, and the average value in the MD direction and the TD direction was taken as the value of the tensile elongation. For measurement, AUTOGRAPH AG-IS manufactured by Shimadzu Corporation was used.

(3) Adhesive force of adhesive layer The adhesive force of the adhesive layer was measured as follows based on JISZ0237. That is, the film was cut out in a width of 25 mm and a length of 300 mm along the MD direction to make a sample, and attached to a SUS304 plate mirror finish with two reciprocations at 10 mm / sec using a 2 kg weight roller. The tensile measurement was performed at a speed of 300 mm / min, and the average value of five measurements for the peel force was taken as the value of the adhesive force. For measurement, AUTOGRAPH AG-IS manufactured by Shimadzu Corporation was used. The 180 degree peel strength thus obtained was taken as the adhesive strength of the adhesive layer.

(4-1) Thickness of base film The film was cut using a microtome, and the cut surface was observed with an optical microscope (Keyence Corporation VHX-900) to measure the thickness of the base film. This was further measured similarly every 1 m in the MD direction (unrolling direction) of the film, and finally the average value of 10 points was taken as the thickness of the substrate film.

(4-2) Thickness of adhesive layer The releasable surface protective film was cut using a microtome, and the cut surface was observed with an optical microscope (Keyence Corporation VHX-900) to measure the thickness of the adhesive layer. This was further measured similarly every 1 m in the MD direction (unrolling direction) of the film, and finally the average value of 10 points was taken as the thickness of the adhesive layer.

(5) Content of Epoxidized Vegetable Oil and Content of Glycerin Fatty Acid Ester A releasable surface protection film is formed into a substrate film and an adhesive by peeling off the adhesive layer of the releasable surface protection film with a spatula. , And each was dissolved in hexafluoro-2-propanol (HFIP) for extraction, and then dried. Each of them is dissolved in d8-tetrahydrofuran (THF), NMR is measured, and epoxidation is carried out according to the internal standard method (internal standard substance; N, N-dimethylformamide (DMF)) from signal analysis value of ¹ H-NMR spectrum. The content of vegetable oil and the content of glycerin fatty acid ester were quantified. The value of the content obtained from the adhesive was taken as the content of the epoxidized vegetable oil contained in the adhesive layer and the content of the glycerin fatty acid ester.

(6) Wet Spreadability Wet spreadability was evaluated by the time taken for wet spread.
The releasable surface protection film was cut into a 20 cm square, and one piece was attached to a glass plate, and both ends of the opposite piece were held by hand and pulled to leave the film free of wrinkles and attached. .
<Evaluation criteria>
◎: The time taken for the wetting spread was less than 5 seconds.
:: The time taken for the wetting spread was 5 seconds or more and less than 10 seconds.
Δ: The time taken for the wetting and spreading was 10 seconds or more.
X: The releasable surface protection film did not stick to the glass plate.

(6) Existence of foam Cut out the releasable surface protection film to a 20 cm square, stick one piece on the glass plate, hold the opposite end of one piece by hand and pull it to make sure that there are no wrinkles in the film. I put it apart.
<Evaluation criteria>
◎: There was no bubble between the film and the glass plate.
○: 1 or 2 bubbles were present between the film and the glass plate.
Fair: 3 to 5 bubbles were present between the film and the glass plate.
X: There were five or more bubbles between the film and the glass plate.

(7) Whether there is wrinkles Cut out a releasable surface protection film into a 20 cm square, stick one piece on a glass plate, hold the opposite end of one piece by hand and pull the hand away from the film without wrinkles. After pasting, it was crimped with the palm of the hand.
<Evaluation criteria>
◎: There were no wrinkles.
○: One or two wrinkles were found.
Fair: 3 to 5 wrinkles were found.
X: There were six or more wrinkles.

(8) Existence of whitening The releasable surface protective film was attached to a keyboard, repeated and key-touched, and random Japanese sentences of 20,000 letters were typed and evaluated.
<Evaluation criteria>
◎: It did not bleach.
○: Whitened, but I could see the letters.
Δ: Whitened and no characters were seen
X: Whitening occurred and powder was generated.

Example 1
[Production of base film]
The base film (PVDC film, thickness: 21 micrometers) which has a vinylidene chloride copolymer (PVDC) as a main component was manufactured as follows.
Vinylidene chloride-vinyl chloride copolymer (vinylidene chloride monomer unit content / vinyl chloride monomer unit content = 80% by mass / 20% by mass, weight average molecular weight 120,000, in Table 1 “PVDC” 3.) 100 parts by mass, 3 parts by mass of dibutyl sebacate as fatty acid esters, 3 parts by mass of acetyltributyl citrate, 2 parts by mass of epoxidized soybean oil as an epoxidized compound, and mixing for 5 minutes with a Henschel mixer did. The resulting mixture is extruded into a tubular shape by a melt extruder, supercooled in a cold water bath at about 10 ° C., then passed through water at 35 ° C., stretching temperature 30 ° C., 3.0 times in the longitudinal (MD) direction, width (TD A tubular film obtained by performing inflation biaxial stretching at 4.0 times in the) direction was folded with a pinch roll to produce a flat long film with a thickness of 42 μm. Thereafter, it was peeled into a single film using a slitter to obtain a 21 μm film. The properties of the obtained film (substrate film) were measured by the above method. The measurement results are shown in Table 1.

[Production of removable surface protective film]
Separator (silicone-treated polyethylene terephthalate (PET) film), urethane 1 (main agent: Toyo Chem SH-101 (100 parts by mass), curing agent: Toyo Chem-T501B (5 parts by mass)) having a thickness of 15 μm The substrate film was coated and wound using a comma coater. Next, a 1.5% solution of the back surface treatment agent (Lion Specialty Chemicals Speiroil 1050) was coated on the base film surface with a gravure coater with a 18 μm grain size and wound up. After aging this at 40 ° C. for 3 days, a removable surface protective film was produced by delaminating the separator. The resulting releasable surface protection film was aged for 1 month at 28 ° C. and then measured for properties as described above. The measurement results are shown in Table 1.

Example 2
As a pressure-sensitive adhesive, instead of urethane 1, urethane 2 (main agent: Toyochem SH-101 (100 parts by mass), curing agent: Toyochem-T501B (6 parts by mass)) is used, and the thickness of the adhesive layer is 20 μm. A removable surface protective film was produced in the same manner as in Example 1 except for the above.

[Example 3 and Example 4]
A removable surface protective film was produced in the same manner as in Example 1 except that the thickness of the substrate film and the thickness of the adhesive layer were changed as shown in Table 1.

[Example 5]
In the same manner as in Example 1, a releasable surface protective film was produced, and the obtained film was further aged at 40 ° C. for one month to obtain a releasable surface protective film.

[Example 6]
In the same manner as in Example 1, a releasable surface protective film was produced, and the obtained film was further aged at 15 ° C. for one month to obtain a releasable surface protective film.

Comparative Example 1
As an adhesive, in place of urethane 1, acrylic 1 (main agent: Siden Chemical MS 3999 (100 parts by mass), curing agent: Siden Chemical K 315 (1.5 parts by mass)) In the same manner as in Example 1, a removable surface protective film was produced.

Comparative Example 2
Example 1 except that acrylic 2 (main agent: Lion Specialty Chemicals AS 665 (100 parts by mass) and curing agent: Lion Specialty Chemicals B-45 (5 parts by mass) were used instead of urethane 2 as the substrate The releasable surface protective film was manufactured in the same manner as in.

Comparative Example 3
A removable surface protective film was produced in the same manner as in Example 1 except that a polyethylene resin was used in place of a vinylidene chloride copolymer as a substrate. In addition, plasticizers, such as fatty acid ester and an epoxidation compound, were not contained in the obtained removable surface protection film.

Comparative Example 4
A removable surface protective film was produced in the same manner as in Example 2 except that a polyethylene resin was used in place of the vinylidene chloride copolymer as a substrate. In addition, plasticizers, such as fatty acid ester and an epoxidation compound, were not contained in the obtained removable surface protection film.

  The properties of the obtained removable surface protective film were measured as described above. The measurement results are shown in Table 1.

  In the table, N / A represents that no measurement data was obtained.

  The releasable surface protective film of the present invention can be attached to bacteria, viruses, blood, vomits, and other body fluids in various inspection devices having an electronic medical record keyboard, a control panel, and the like in contact with a plurality of medical personnel in a hospital. It can prevent adhesion and prevent cross-infection among medical personnel. Further, the releasable surface protective film of the present invention is also difficult to stretch and break at the corners of various devices as well, and can be used to protect devices, particularly medical devices, because it is difficult to tear. Therefore, the releasable surface protection film of the present invention has industrial applicability as a surface protection film of a device or apparatus used at a medical site.

1: Surface protection film 2: Base film 3: Adhesive layer 4: Release layer 5: Separator

Claims (8)

A substrate film,
An adhesive layer disposed on the substrate film;
A releasable surface protection film having
The substrate film contains a vinylidene chloride copolymer as a main component,
The adhesive layer contains a polyurethane adhesive as a main component,
Removable surface protection film.   The releasable surface protection film of Claim 1 whose adhesive force of the said adhesive film is 0.03-0.30 N / 25 mm. The thickness of the substrate film is 10 to 30 μm,
2% strain elastic modulus in the flow direction (MD direction) and 2% strain elastic modulus in the width direction (TD direction) are respectively 190 to 400 MPa, and
Tensile elongation in the flow direction (MD direction) and width direction (TD direction) satisfy 80 to 150%, respectively
The removable surface protection film according to claim 1.   The adhesive layer according to any one of claims 1 to 3, wherein 40 to 80% of the epoxidized vegetable oil contained in the removable surface protective film and 40 to 80% of the fatty acid glycerin ester are contained in the adhesive layer. Removable surface protection film.   The releasable surface protective film according to any one of claims 1 to 4, wherein the thickness of the adhesive layer is 1.0 to 30 μm.   The releasable surface protection film according to any one of claims 1 to 5, wherein the polyurethane pressure-sensitive adhesive contains, as a main agent, a polyurethane having a hydroxyl group and, as a curing agent, an aliphatic diisocyanate.   The removable surface protective film winding body provided with a cylindrical core and the removable surface protective film according to any one of claims 1 to 6 wound around the core.   The removable surface protective film according to any one of claims 1 to 6, which is used for protecting a medical device.