JP6716222B2 - Wrapping film and processed products - Google Patents

Description

The present invention relates to a wrapping film and a wrapping processed product.

The wrapping film is used by being attached to a vehicle such as a bicycle, a motorcycle, an automobile, a bus, and a train, or a part or whole of these parts, home appliances, and the like. Since these objects to be attached have a curved surface shape, the lapping film is required to have conformability to the curved surface shape. Further, in addition to having good workability when applying the lapping film to the object to be attached, it is required to have good workability also when peeling the film for lapping from the object to be attached.

For example, Patent Document 1 discloses a pressure-sensitive adhesive film including a base film and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer contains an aqueous pressure-sensitive adhesive composition containing a water-dispersed pressure-sensitive adhesive resin and having a predetermined concentration of ionic components. It is disclosed that, by using it, excellent physical properties such as peeling properties and reworkability can be obtained, and changes in physical properties such as peeling properties can be stably suppressed over time or under environmental factors.

Special table 2013-501842 gazette

The wrapping film is required to have good workability during construction, have a sufficient initial adhesive force, and be easy to reattach. Although there are some conventional adhesives that have good adhesive strength, there are problems such as high adhesiveness that makes it difficult to re-attach, and adhesive strength that increases over time, making it difficult to remove, and there is room for consideration. It was Further, the wrapping film is required to have good dimensional stability after construction.

From the above, there has been a demand for a lapping film that follows a curved surface shape, has good workability during construction and peeling, and has excellent dimensional stability.

The present inventor studied the pressure-sensitive adhesive composition used for the pressure-sensitive adhesive layer, and found that the pressure-sensitive adhesive force can be reduced by adding a methacrylic acid ester copolymer to the acrylic pressure-sensitive adhesive compound. Further, by setting the addition amount of the methacrylic acid ester copolymer, the weight average molecular weight (hereinafter, also referred to as Mw), and the glass transition temperature (hereinafter, also referred to as Tg) within specific ranges, the work at the time of construction and peeling The present invention has been completed by finding that a lapping film having good properties and excellent dimensional stability can be obtained.

The wrapping film of the present invention is laminated in the order of a polyvinyl chloride film layer, an adhesive layer, a release film or a release paper, and the adhesive layer contains an acrylic adhesive compound and a methacrylic acid ester copolymer. The acrylic pressure-sensitive adhesive compound has a weight average molecular weight of 500,000 or more and 1,000,000 or less, and the methacrylic acid ester copolymer has a weight average molecular weight of 5,000 or more and 80,000 or less, and a glass transition temperature. Is 20° C. or higher and 130° C. or lower, and the content of the methacrylic acid ester copolymer is 7 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic adhesive compound. To do.

The pressure-sensitive adhesive layer preferably has a thickness of 10 μm or more and 50 μm or less.

The lapping processed product of the present invention is characterized in that the release film or the release paper is peeled from the lapping film of the present invention, and the pressure-sensitive adhesive layer is attached to a three-dimensional curved surface of the molded product. ..

Since the lapping film of the present invention is thin and flexible, it can follow a curved surface shape. Furthermore, the pressure-sensitive adhesive layer contains a specific weight average molecular weight and a specific amount of a methacrylic acid ester copolymer having a glass transition temperature, so that workability during construction and peeling is good, and dimensional stability is obtained. A wrapping film having excellent properties can be obtained.

The wrapping film of the present invention is laminated in the order of a polyvinyl chloride film layer, an adhesive layer, a release film or a release paper, and the adhesive layer contains an acrylic adhesive compound and a methacrylic acid ester copolymer. The acrylic pressure-sensitive adhesive compound has a weight average molecular weight of 500,000 or more and 1,000,000 or less, and the methacrylic acid ester copolymer has a weight average molecular weight of 5,000 or more and 80,000 or less, and a glass transition temperature. Is 20° C. or higher and 130° C. or lower, and the content of the methacrylic acid ester copolymer is 7 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic adhesive compound. To do.

[Polyvinyl chloride film layer]
The polyvinyl chloride film layer is a film layer made of a polyvinyl chloride resin. Since the polyvinyl chloride film has good elongation and is difficult to break, it can be easily attached to a three-dimensional curved surface. Further, it has excellent printability and is softened by heat of a dryer or the like, and therefore, it is suitable as a base material for a lapping film. The polyvinyl chloride resin is not particularly limited, but can be obtained, for example, by adding a plasticizer to polyvinyl chloride. Polyvinyl chloride having a polymerization degree of 800 to 1200 is preferably used.

As the plasticizer, those usually used in the field of film can be used, and examples thereof include octyl phthalate (di-2-ethylhexyl phthalate), dibutyl phthalate, diester phthalates such as dinonyl phthalate, and adipic acid. Dioctyl, aliphatic dibasic acid diesters such as dioctyl sebacate, tricresyl phosphate, phosphate triesters such as trioctyl phosphate, epoxy plasticizers such as epoxidized soybean oil and epoxy resin, high molecular polyester plasticizers, etc. To be The preferred lower limit of the amount of the plasticizer added to 100 parts by weight of the vinyl chloride resin is 20 parts by weight, and the preferred upper limit is 30 parts by weight.

The polyvinyl chloride resin may contain a heat stabilizer. As the heat stabilizer, those generally used in the field of film can be used, and for example, lead (Pb), barium (Ba), zinc (Zn), calcium (Ca), tin (Sn), etc. can be used. Examples thereof include metal organic acid compounds.

The preferable lower limit of the thickness of the polyvinyl chloride film layer is 30 μm, the preferable upper limit is 200 μm, the more preferable lower limit is 40 μm, the more preferable upper limit is 150 μm, the still more preferable lower limit is 50 μm, and the still more preferable upper limit. Is 100 μm. If the thickness of the polyvinyl chloride film layer is less than 30 μm, it may become too thin and the undercoat may be transparent when it is attached to an attachment target having a curved shape. When the thickness of the polyvinyl chloride film layer is more than 200 μm, the wrapping film may have insufficient followability when it is attached to an attachment target having a curved shape.

[Adhesive layer]
The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive compound and a methacrylic acid ester copolymer. By using an acrylic pressure-sensitive adhesive compound as a main component, the pressure-sensitive adhesive layer can exhibit good adhesiveness at room temperature. Further, by using an acrylic adhesive compound as a main agent and a methacrylic acid ester copolymer as an additive, the adhesiveness at room temperature can be reduced as compared with the case where the acrylic adhesive compound is used alone, and In addition, sufficient tackiness can be developed in the working temperature range, and the tackiness can be maintained even at high temperatures. Therefore, both the adhesive force when the lapping film is attached to the pasting target and the ease of peeling when peeling from the pasting target are compatible with each other, and further excellent dimensional stability is obtained.

As the acrylic adhesive compound, for example, alkyl (meth)acrylate can be used. When the alkyl group has an excessively long chain, it may be difficult to control the glass transition temperature (Tg) and the tackiness, and therefore an alkyl(meth)acrylate having an alkyl group having 1 to 12 carbon atoms is preferable. When an alkyl (meth)acrylate containing an alkyl group having 10 or more carbon atoms is used, the initial adhesive force of the pressure-sensitive adhesive is good, but the cohesive force may be somewhat reduced. Therefore, an alkyl group having 2 to 8 carbon atoms is used. It is preferable to use a (meth)acrylate containing a suitable mixture. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth). ) Acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth) ) Acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, and tetradecyl (meth)acrylate. The alkyl (meth)acrylates may be used alone or in combination of two or more. In addition, (meth)acrylate represents acrylate and methacrylate.

The acrylic pressure-sensitive adhesive compound has a weight average molecular weight of 500,000 or more and 1,000,000 or less. When the weight average molecular weight of the acrylic pressure-sensitive adhesive compound is less than 500,000, the initial pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer may be high and re-adhesion may be difficult, and when it exceeds 1,000,000, the pressure-sensitive adhesive layer may be hard. It may be difficult to adhere. The preferred lower limit of the weight average molecular weight of the acrylic pressure-sensitive adhesive compound is 550,000, the preferred upper limit is 800,000, the more preferred lower limit is 600,000, the more preferred upper limit is 750,000, and the still more preferred upper limit is 700,000. Is. The weight average molecular weight of the acrylic pressure-sensitive adhesive compound can be measured, for example, by gel permeation chromatography (GPC).

The acrylic adhesive compound may have a glass transition temperature of -50°C or higher and -20°C or lower. The more preferable lower limit of the glass transition temperature of the acrylic pressure-sensitive adhesive compound is −45° C., the more preferable upper limit is −25° C., the still more preferable lower limit is −40° C., and the still more preferable upper limit is −30° C.

As the acrylic adhesive compound, for example, AR2120EA manufactured by Big Technos, SK Dyne 1604N, SK Dyne 1340, and SK Dyne 1310 manufactured by Soken Kagaku Co., Ltd. can be used.

Examples of the methacrylic acid ester copolymer include a polymer of (meth)acrylic acid alkyl ester and an amino group-containing unsaturated monomer.

In the above (meth)acrylic acid alkyl ester, the alkyl group preferably has 1 to 12 carbon atoms, and more preferably the alkyl group has 4 to 8 carbon atoms. Examples of the (meth)acrylic acid alkyl ester include ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n. -Octyl (meth)acrylate, iso-octyl (meth)acrylate, lauryl (meth)acrylate, iso-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. are mentioned.

Examples of the unsaturated monomer containing an amino group include aminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, dimethylaminopropyl(meth)acrylate, vinylpyridine and the like.

As the methacrylic acid-based ester copolymer, for example, Thermoken U-245B and Ktoflow UMB-1010 manufactured by Soken Chemical Industry Co., Ltd. can be used.

The methacrylic acid ester copolymer has a weight average molecular weight of 5,000 or more and 80,000 or less and a glass transition temperature of 20° C. or more and 130° C. or less. When the weight average molecular weight of the methacrylic acid-based ester copolymer is less than 5,000, the initial adhesive strength of the pressure-sensitive adhesive layer becomes high, and it may be difficult to reattach the wrapping film, and if it exceeds 80,000. In some cases, the initial adhesive force of the pressure-sensitive adhesive layer becomes low, and the adhesive force of the wrapping film becomes insufficient. Further, when the glass transition temperature is lower than 20° C., the initial adhesive force of the pressure-sensitive adhesive layer becomes high, which may make it difficult to reattach the lapping film. Further, since the heat resistance decreases, the dimensional stability may decrease. When the glass transition temperature exceeds 130°C, the initial adhesive force of the pressure-sensitive adhesive layer may be low, and the adhesive force of the wrapping film may be insufficient. The preferred lower limit of the weight average molecular weight of the methacrylic acid ester copolymer is 7,000, the preferred upper limit is 50,000, the more preferred lower limit is 9000, the more preferred upper limit is 45,000, and the still more preferred upper limit is 40,000. .. The preferable upper limit of the glass transition temperature of the methacrylic acid ester copolymer is 100°C. By using a methacrylic acid ester copolymer having a glass transition temperature higher than the glass transition temperature of the acrylic pressure-sensitive adhesive compound, the heat resistance of the wrapping film is improved, and thus the dimensional stability is improved. The weight average molecular weight of the methacrylic acid ester copolymer can be measured, for example, by gel permeation chromatography (GPC). The glass transition temperature of the methacrylic acid-based ester copolymer can be measured, for example, by a differential scanning calorimetry (DSC).

The content of the methacrylic acid ester copolymer is 7 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic adhesive compound. When the content of the methacrylic acid ester copolymer is less than 7 parts by weight, the dimensional stability of the wrapping film may be low, and when it exceeds 15 parts by weight, the adhesive strength of the wrapping film is high. May be insufficient. The preferable lower limit of the content of the methacrylic acid ester copolymer is 100 parts by weight and the preferable upper limit thereof is 13 parts by weight with respect to 100 parts by weight of the acrylic adhesive compound.

The pressure-sensitive adhesive layer may contain a curing agent. By containing a curing agent, the dimensional stability of the wrapping film can be improved. The curing agent is not particularly limited, for example, tolylene diisocyanate, isocyanate curing agent such as hexamethylene diisocyanate, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, epoxy curing agent such as tetraglycidyl xylene diamine, Examples thereof include metal chelating agents such as Al, Ni and Zn, and amino resin curing agents such as melamine compounds. As the isocyanate-based curing agent, for example, Coronate L-55 manufactured by Tosoh Corporation can be used. The content of the curing agent may be 5 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic pressure-sensitive adhesive compound.

The pressure-sensitive adhesive layer preferably has a thickness of 10 μm or more and 50 μm or less. When the thickness of the pressure-sensitive adhesive layer is less than 10 μm, the pressure-sensitive adhesive layer becomes too thin when the film for lapping is stretched for sticking to a three-dimensional curved surface, and thus the object to which the film for lapping is attached The adhesive strength to the surface may be insufficient, and if it exceeds 50 μm, the initial adhesive strength may be high, and re-adhesion may be difficult. In addition, since a large amount of the pressure-sensitive adhesive composition is used, it is not economical. The more preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 20 μm, and the more preferable upper limit thereof is 40 μm.

[Release film, release paper]
As the release film and the release paper, those usually used in the field of film can be used. Examples of the release film include a polyethylene terephthalate (PET) film whose surface is coated with a silicone-based, alkyd-based, or fluorine-based release agent. Examples of the release paper include fine paper coated on the surface with a silicone-based, alkyd-based, or fluorine-based release agent. The release film or release paper may be surface-treated only on the pressure-sensitive adhesive layer side surface.

The polyvinyl chloride film layer may be printed on the surface opposite to the pressure-sensitive adhesive layer. Printing on the polyvinyl chloride film layer can be performed by, for example, inkjet printing, gravure printing, screen printing, rotary screen printing, flexographic printing, offset printing, electrostatic printing, or the like. Further, the polyvinyl chloride film layer may have fine irregularities on the surface opposite to the pressure-sensitive adhesive layer by embossing or the like.

The polyvinyl chloride film layer may have a protective film layer on the side opposite to the pressure-sensitive adhesive layer. As the protective film, those usually used in the field of film can be used. Examples of the protective film include polyethylene terephthalate (PET) resin, polypropylene (PP) resin, and polycarbonate resin.

The method for producing the film for wrapping is not particularly limited, but for example, the polyvinyl chloride film layer is formed by calendering after melt-kneading the polyvinyl chloride resin using a Banbury mixer or the like. You can The pressure-sensitive adhesive layer is coated with the pressure-sensitive adhesive composition on the release film or release paper by using a general-purpose film forming apparatus or film forming method such as various coating devices, bar coat, doctor blade, and the like. It can be formed by drying. A lapping film can be obtained by laminating the pressure-sensitive adhesive layer on the polyvinyl chloride film layer.

The above lapping film preferably has an adhesive strength measured by a 180° peel test of 5 N/25 mm or more and 11 N/25 mm or less at room temperature and normal humidity. The 180° peeling test is performed by a method according to JIS Z 0237. By measuring the initial adhesive force, it is possible to confirm the adhesive force of the wrapping film immediately after being attached to the object to be attached. When the initial adhesive force is 5 N/25 mm or more and 11 N/25 mm or less, the wrapping film has sufficient adhesive force to the object to be attached and is easy to be peeled off again. Furthermore, even if the above-mentioned wrapping film is attached to the object to be attached again, sufficient adhesive force can be obtained. The details of the test method of the 180° peel test will be described later.

Examples of the method of applying the lapping film include a method of laminating the lapping film on an object to be pasted, heating it with an oven, a drier or the like, and pasting it. For small or medium-sized objects to be attached such as parts of vehicles, methods such as vacuum forming, pressure forming, vacuum/pressure forming, in-mold forming, film insert forming, and laminating can be used. Large objects to be attached such as vehicles cannot be heated by a device such as an oven, so they may be attached manually while being heated by a dryer or the like. The wrapping film appropriately expands at a heating temperature of a dryer (about 80° C.) and exhibits sufficient adhesive force. Therefore, the wrapping film can be attached to the three-dimensional curved surface while being warmed and extended by a dryer or the like. Since the hot-melt adhesive has a high processing temperature of 140° C. to 180° C., it is difficult to develop sufficient adhesive force by a manual attachment method using a dryer or the like.

The surface shape of the pasting target may be any of a flat surface, an uneven surface, and a curved surface. Since the above wrapping film has a conformability to a curved surface shape, it can be suitably attached to a three-dimensional curved surface.

The material of the pasting object is not particularly limited, and examples thereof include resins such as polycarbonate resins, acrylic resins, and styrene resins, ABS resins; metals such as iron, copper, and aluminum; alloys and the like.

The object to be pasted is not particularly limited, but examples thereof include vehicles such as bicycles, motorcycles, automobiles, buses, and trains; helmets; ships; aircraft such as airplanes and helicopters; household items such as furniture and home appliances; cabinets, office work. Office supplies such as desks and personal computers; wall surfaces, floors, ceilings, roofs, columns, signboards, doors, gates of buildings; or building materials for construction sites, or parts thereof.

The wrapping film can be used, for example, for decorating, protecting, advertising or the like of the surface of the pasting target. Further, characters, patterns, etc. may be transferred to the surface of the wrapping film opposite to the pressure-sensitive adhesive layer, and the wrapping film may be stuck on the sticking target to be used as an advertisement.

The lapping processed product of the present invention is characterized in that the release film or the release paper is peeled from the lapping film of the present invention, and the pressure-sensitive adhesive layer is attached to a three-dimensional curved surface of the molded product. .. Examples of the above-mentioned molded product include the above-mentioned pasting target, and the above lapping film can be used by being stuck onto a part or the whole of the above-mentioned molded product.

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

(Example 1)
First, 28 parts by weight of a plasticizer was added to 100 parts by weight of a vinyl chloride resin having an average degree of polymerization of 800 to obtain a polyvinyl chloride resin. The obtained polyvinyl chloride resin was melt-kneaded with a Banbury mixer and then calendered to form a polyvinyl chloride film layer. The thickness of the polyvinyl chloride film layer was 50 μm. Next, with respect to 100 parts by weight of an acrylic adhesive compound having a weight average molecular weight of 650,000 and a glass transition temperature of −34° C. (for example, SK Dyne 1604N manufactured by Soken Chemical Co., Ltd.), the weight average molecular weight is 10,000 and the glass transition. A pressure-sensitive adhesive composition was prepared by adding 10 parts by weight of a methacrylic acid ester copolymer having a temperature of 30° C. and 5.7 parts by weight of a curing agent. As the curing agent, an isocyanate curing agent having a solid content of 55% (for example, Coronate L-55 manufactured by Tosoh Corporation) was used. The obtained pressure-sensitive adhesive composition was coated on a release paper with a comma coater so that the thickness of the dried pressure-sensitive adhesive layer would be 30 μm. Then, the film was transferred to a polyvinyl chloride film layer to obtain a wrapping film of Example 1.

(Example 2)
A wrapping film of Example 2 was obtained in the same manner as in Example 1 except that a methacrylic acid ester copolymer having a weight average molecular weight of 40,000 and a glass transition temperature of 100° C. was used.

(Example 3)
A lapping film of Example 3 was obtained in the same manner as in Example 1 except that 7 parts by weight of a methacrylic acid ester copolymer was added to 100 parts by weight of the acrylic adhesive compound.

(Example 4)
A lapping film of Example 4 was obtained in the same manner as in Example 1 except that 15 parts by weight of the methacrylic acid ester copolymer was added to 100 parts by weight of the acrylic adhesive compound.

(Example 5)
A lapping film of Example 5 was obtained in the same manner as in Example 1 except that an acrylic pressure-sensitive adhesive compound having a weight average molecular weight of 550,000 and a glass transition temperature of -40°C was used.

(Example 6)
A lapping film of Example 6 was obtained in the same manner as in Example 1 except that an acrylic adhesive compound having a weight average molecular weight of 800,000 and a glass transition temperature of -32°C was used.

(Example 7)
A wrapping film of Example 7 was obtained in the same manner as in Example 1 except that a methacrylic acid ester copolymer having a weight average molecular weight of 5000 and a glass transition temperature of 35°C was used.

(Example 8)
A lapping film of Example 8 was obtained in the same manner as in Example 1 except that an acrylic adhesive compound having a glass transition temperature of -32°C was used.

(Example 9)
The same procedure as in Example 1 was carried out except that an acrylic adhesive compound having a glass transition temperature of −43° C., a weight average molecular weight of 80,000, and a methacrylic acid ester copolymer having a glass transition temperature of 130° C. were used. A wrapping film of Example 9 was obtained.

(Example 10)
In the same manner as in Example 1 except that an acrylic adhesive compound having a weight average molecular weight of 1,000,000 and a glass transition temperature of -43°C and a methacrylic acid ester copolymer having a glass transition temperature of 65°C were used. The lapping film of Example 10 was obtained.

(Comparative Example 1)
Comparative Example 1 was carried out in the same manner as in Example 1 except that an acrylic adhesive compound having a weight average molecular weight of 450,000 and a glass transition temperature of -47° C. (for example, SK Dyne 1340 manufactured by Soken Chemical Industry Co., Ltd.) was used. A wrapping film was obtained.

(Comparative example 2)
Comparison was performed in the same manner as in Example 1 except that an acrylic adhesive compound having a glass transition temperature of −43° C., a weight average molecular weight of 100,000 and a methacrylic acid ester copolymer having a glass transition temperature of 150° C. were used. The lapping film of Example 2 was obtained.

(Comparative example 3)
Comparison was performed in the same manner as in Example 1 except that an acrylic adhesive compound having a glass transition temperature of −43° C., a weight average molecular weight of 4000, and a methacrylic acid ester copolymer having a glass transition temperature of 15° C. were used. A wrapping film of Example 3 was obtained.

(Comparative Example 4)
Comparison was performed in the same manner as in Example 1 except that 6 parts by weight of a methacrylic acid ester copolymer was added to 100 parts by weight of an acrylic adhesive compound having a glass transition temperature of −43° C. and an acrylic adhesive compound. A wrapping film of Example 4 was obtained.

(Comparative example 5)
Comparison was performed in the same manner as in Example 1 except that 16 parts by weight of a methacrylic acid ester copolymer was added to 100 parts by weight of an acrylic adhesive compound having a glass transition temperature of −43° C. and an acrylic adhesive compound. A wrapping film of Example 5 was obtained.

(Comparative example 6)
A lapping film of Comparative Example 6 was obtained in the same manner as in Example 1 except that an acrylic adhesive compound having a glass transition temperature of -43°C was used and no methacrylic acid ester copolymer was added. It was

(Evaluation of film for wrapping)
With respect to the lapping films produced in Examples and Comparative Examples, (1) measurement and evaluation of initial adhesive strength, (2) evaluation of workability, and (3) evaluation of dimensional stability were performed by the following methods. .. From the evaluation results of (1) to (3), (4) comprehensive evaluation was performed.

(1) Measurement of initial adhesive strength The lapping films produced in the examples and comparative examples were cut into 100 mm length and 100 mm width to prepare test pieces. The release paper was peeled from each test piece, adhered to an aluminum plate having a length of 160 mm and a width of 160 mm with a pressure roller of 1 kg, and allowed to stand for 1 minute, followed by a 180° peel test to measure the adhesive strength. The evaluation was carried out by the method according to JIS Z 0237. The target value of the initial adhesive force was ±3 N/25 mm, that is, 5 N/25 mm to 11 N/25 mm with 8 N/25 mm as a reference.

(2) Evaluation of workability The lapping films produced in Examples and Comparative Examples were cut into 100 mm length and 100 mm width to prepare test pieces. The release paper was removed from each test piece, and it was attached by hand to an aluminum plate having a length of 160 mm and a width of 160 mm, and then peeled by hand. Then, the peeled lapping film was manually attached to the aluminum plate again, and the workability of the reattachment work was evaluated according to the following criteria.
Workability evaluation criteria 1: The lapping film cannot be peeled from the aluminum plate.
2: The wrapping film can be peeled from the aluminum plate, but it requires a very strong force. Adhesion is sufficient when it is reattached to an aluminum plate.
3: The wrapping film can be peeled from the aluminum plate, but it requires a certain amount of force. Adhesion is sufficient when it is reattached to an aluminum plate.
4: The lapping film can be peeled off from the aluminum plate by applying a little force. Adhesive strength is sufficient when reattached to an aluminum plate.
5: The lapping film can be easily peeled off from the aluminum plate. Adhesive strength is sufficient when reattached to an aluminum plate.
The larger the number, the better the workability, and the smaller the number, the worse the workability. The target value for evaluation of workability was set to 4 or more.

(3) Evaluation of Dimensional Stability The wrapping films produced in Examples and Comparative Examples were cut into 100 mm length and 100 mm width to prepare test pieces. The release paper was peeled from each test piece and attached to an aluminum plate having a length of 150 mm and a width of 150 mm by using a squeegee, a roller and the like. Then, a 100 mm cut was made in the cross direction in the flow direction and the width direction of the attached lapping film with a cutter knife, and the film was left for 48 hours in an environment of 65°C. After 48 hours, the dimension in the flow direction and the dimension in the width direction of the lapping film were measured. The target value of the dimensional stability evaluation was such that the dimensional change in the flow direction and the width direction was 0.3 mm or less. The film flow direction means the longitudinal direction of the film when the film is formed by calendering, and the width direction means the lateral direction of the film when the film is formed by calendering.

(4) Comprehensive evaluation If all the evaluation items of (1) to (3) above satisfy the target value, it is evaluated as ◯, and if there is one or more items that deviate from the target value of the evaluation items of (1) to (3) above, it is evaluated as x. ..

The lapping film structure according to the example and the evaluation results are shown in Table 1, and the lapping film structure according to the comparative example and the evaluation results are shown in Table 2.

Claims (3)

A polyvinyl chloride film layer, an adhesive layer, a release film or release paper are laminated in this order,
The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive compound and a methacrylic acid ester copolymer,
The acrylic adhesive compound has a weight average molecular weight of 500,000 or more and 750,000 or less,
The methacrylic acid ester copolymer has a weight average molecular weight of 5000 or more and 10000 or less, and a glass transition temperature of 20° C. or more and 130° C. or less,
The content of the methacrylic acid ester copolymer is 7 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic adhesive compound,
The film for lapping, wherein the polyvinyl chloride film layer has a thickness of 40 μm or more and 200 μm or less, and the adhesive layer has a thickness of 10 μm or more and 50 μm or less. The pressure-sensitive adhesive layer further contains a curing agent,
The content of the curing agent is 5 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the acrylic adhesive compound.
The film for lapping according to claim 1, wherein the film is a lapping film. The lapping processed product, wherein the release film or the release paper is peeled from the lapping film according to claim 1 or 2 , and the pressure-sensitive adhesive layer is attached to a three-dimensional curved surface of a molded product. ..