JP4783113B2 - Decoration / Security Film - Google Patents

Description

  The present invention relates to a decorative / crime-preventing film that is used by being attached to a window glass of a house or the like, and more specifically, is suitably attached to a glass having an uneven surface such as a flat template glass or polished glass. It relates to decorative and security films that can

  For example, in crimes such as burial, vandalism, and robbery, there are many cases where the window glass is broken and penetrates into the inside of the building. For example, a part of the glass fitted in an aluminum sash is broken to remove it from the damaged part. The door frame is locked, for example, the crescent lock is unlocked to enter the room or the like (hereinafter, for convenience of explanation, a window glass of a house or the like is illustrated) Explain).

  In this way, as a defensive measure against the intrusion into the room by breaking the window glass, a resin film called “security film” is attached to the indoor surface of the window glass to strengthen the window glass, Even when the glass is struck by, for example, processing is performed so that the glass cannot be easily broken.

  In this way, sticking of a crime prevention film to the window glass is an effective means for crime prevention. However, in the window glass, a polished glass whose surface is frosted for the purpose of blocking the line of sight from the outside or for a decorative effect. In addition, many are used which have a concavo-convex surface such as a template glass having a concavo-convex pattern on the surface.

  For this reason, even if you try to attach a security film as described above to a window glass, the followability of the adhesive to the uneven surface of the glass is poor, and the desired strength can not be obtained. In addition, the glass could not be tempered, and further, air was collected between the glass and the security film, which made it look bad.

  As a crime prevention film for the purpose of sticking to the glass having such an uneven surface, the adhesive material layer 20 formed on the back surface of the polycarbonate film which is the base material 10 has a relatively thick thickness of 150 to 200 μm. As an anti-crime film (see Patent Document 1: FIG. 2 (A)) having improved adhesion to an uneven surface, or as a double-sided tape 20 ′ to be attached to the surface film 10 ′, an acrylic pressure-sensitive adhesive layer 21 on both sides of the acrylic foam 24 One in which “, 22” is formed has been proposed (see Patent Document 2: FIG. 2B).

Prior art document information of the present invention includes the following.
Japanese Patent Laid-Open No. 2005-180068 JP 2004-155092 A

  The pressure-sensitive adhesive is a resin that has viscoelasticity at room temperature and flows due to pressure contact with the adherend to bring about an adhesive force. The adhesive force is exhibited by the fluidity of the pressure-sensitive adhesive.

  For this reason, in the crime prevention film 1 having the adhesive layer 20 in which the acrylic adhesive is formed much thicker than the conventional product, like the crime prevention film 1 described in the above-mentioned Patent Document 1, such an adhesion is provided. Even when the unevenness of the surface of the glass 30 is large due to the thickness of the agent layer 20, the pressure-sensitive adhesive layer 20 is adapted to the unevenness and exhibits adhesive force ("0012" column of Patent Document 1).

  However, on the other hand, such an improvement in adhesive strength is obtained by the fluidity of the pressure-sensitive adhesive. When the thickness of the pressure-sensitive adhesive layer 20 is increased as described above, the flow-adhesive pressure is increased accordingly. The amount of agent also increases.

  Therefore, when the security film 1 is cut or the like, the adhesive in the cross section flows, and the adhesive sticks to the blade of the cutting machine when the film is formed. Frequent maintenance of the cutter is forced, and there is an adverse effect such as a deviation in dimensions during cutting.

  Further, when the thickness of the pressure-sensitive adhesive layer 20 is increased as described above, it takes time to dry the pressure-sensitive adhesive layer 20 and the productivity is lowered.

  On the other hand, in the invention described in Patent Document 2, an acrylic foam 24 is interposed in the intermediate layer as a member corresponding to the pressure-sensitive adhesive layer 20 in Patent Document 1, and the acrylic pressure-sensitive adhesive layer is formed on both surfaces of the acrylic foam 24. A double-sided tape 20 ′ formed with 21 ′ and 22 ′ is used.

  As described above, the acrylic foam 24 having deformability but not fluidity is interposed between the adhesive layers, whereby the acrylic foam 24 is deformed with respect to the unevenness of the glass 30 surface, and the uneven surface of the glass is exposed. While exhibiting followability, the pressure-sensitive adhesive layers 21 ′ and 22 ′ can be formed relatively thin, so that the pressure-sensitive adhesive as described above can be prevented.

  However, the acrylic foam 24 provided on the double-sided tape 20 'has deformability, but does not have fluidity. Therefore, when the thickness of the pressure-sensitive adhesive layer is increased as in the invention described in Patent Document 1 described above. In comparison, the adhesive strength decreases.

  That is, in the pressure-sensitive adhesive layer 20 formed of only the pressure-sensitive adhesive, since the pressure-sensitive adhesive layer 20 as a whole is formed of a flowable pressure-sensitive adhesive, it is pressed and adhered to the uneven surface of the glass 30. However, once the pressure-sensitive adhesive enters the irregularities of the glass, the pressure-sensitive adhesive exhibits a stable and strong adhesive force in this shape [see FIG. 2 (A)], but the invention described in Patent Document 2 As described above, when the acrylic foam 24 is interposed to form the double-sided tape 20 ′, the acrylic foam 24 is deformed according to the uneven shape of the glass 30, but it is difficult to deform into a shape that completely matches the uneven shape of the glass 30. Even if the pressure-sensitive adhesive layer 22 ′ enters the irregularities on the glass surface, it is difficult for the adhesive to reach the bottom of the irregularities.

  In addition, since the adhesive layer 22 ′ is applied with a force to return to the original flat shape by the restoring force of the acrylic foam 24, the adhesive layer 22 ′ is lifted from the concave portion of the glass 30, and the adhesive force is reduced. [Refer to FIG. 2B].

  Thus, if the adhesive force of the security film 1 is insufficient, even if the security film 1 is attached to the window glass, the strength of the window glass cannot be improved to the intended level. Moreover, it peels after sticking, or air and water enter between glass and a security film, and the following problems are accompanied.

  In particular, the above-mentioned polished glass and stencil glass are used for the purpose of blocking the field of view from the outside, and are therefore often used for bathroom windows. However, as described above, the glass surface and the adhesive layer 21 ' If there is even a slight gap between the glass and the water in the winter season or in the bathroom, condensation will enter the glass surface and the adhesive layer, and the security film 1 will dissociate or peel off from the glass surface and water will enter. , It becomes easier to peel off and the effect of the security film is lost.

  As described above, in the conventional crime prevention film, in order to improve the adhesion to the uneven surface, when the thickness of the pressure-sensitive adhesive layer is increased, the adhesive force can be maintained, but there is a problem such as the pressure-sensitive adhesive layer protruding. On the other hand, when acrylic foam or the like is interposed between the adhesive layers as a base material to prevent such protrusion, there is a problem that the adhesive force is reduced due to the restoring force, etc. There is no security film that can be applied to a security film that can solve these problems simultaneously.

  Therefore, the present invention can be applied to a glass having an uneven surface such as a wire-filled glass or a template glass with a high adhesive force, and also reduces the productivity and the pressure-sensitive adhesive when thickly applying a pressure-sensitive adhesive. The object is to provide a decorative / crime-preventing film that does not cause problems such as protrusion of the agent.

In order to achieve the above object, the decorative / security film 1 of the present invention is provided with a pressure-sensitive adhesive layer 20 on one side of a substrate 10 made of a resin film, and the surface on which the pressure-sensitive adhesive layer 20 is formed is attached to a window glass 30. In the decorative and crime prevention film 1 to be used
The low-molecular pressure-sensitive adhesive layers 21 and 22 made of a pressure-sensitive adhesive having a relatively low molecular weight, the pressure-sensitive adhesive layer 20 being disposed on the lamination side with respect to the base material 10 and the bonding side with respect to the glass 30, and the low-molecular weight It is formed by laminating a polymer adhesive layer 23 made of an adhesive having a relatively high molecular weight with respect to the low molecular adhesive layers 21 and 22 disposed between the adhesive layers 21 and 22. (Claim 1).

  In the decorative / crime-prevention film 1 having the above structure, the low molecular adhesive layers 21 and 22 have an average molecular weight of 2,000 to 100,000, preferably 2,000 to 40,000, and the high molecular adhesive layer 23 has an average molecular weight of 5,000 to 500,000, preferably 200,000 to 300,000 (Claim 2).

  Further, the total thickness of the pressure-sensitive adhesive layer 20 can be filled with the depth of the unevenness (about 150 μm) on the uneven surface of the template glass. From the viewpoint of preventing the occurrence of a decrease in productivity and the sticking out of the adhesive at the time of cutting, it is 150 to 300 μm, more preferably 160 to 250 μm, and the thickness of the polymer adhesive layer 23 is 1 to 100 μm, More preferably, the thickness is 10 to 50 μm, more preferably 5 to 50 μm, and 10 to 15 μm. The thickness of the low molecular adhesive layer 22 on the glass side is 50 to 120 μm, preferably 70 to 120 μm, and more preferably 80 to 110 μm. On the substrate (PET film) 10 side, 50 to 145 μm, preferably 70 to 120 μm, 80 to 110 μm is more suitable (claim 4).

  The polymer adhesive layer 23 and the low molecular adhesive layers 21 and 22 can both be formed of an acrylic resin.

  As the substrate 10, a polyester film having a thickness of 100 to 500 μm, preferably 150 to 400 μm can be used.

  As described above, the low-molecular pressure-sensitive adhesive layers 21 and 22 disposed on the polyester film substrate 10 side of the pressure-sensitive adhesive layer 20 and the bonding side with respect to the glass 30 surface, and between these low-molecular pressure-sensitive adhesive layers 21 and 22 By forming the pressure-sensitive adhesive layer 20 by laminating the arranged polymer pressure-sensitive adhesive layers 23, the pressure-sensitive adhesive is increased by the polymer pressure-sensitive adhesive layer 23 having a high molecular weight and therefore inferior fluidity compared to the low-molecular pressure-sensitive adhesive layers 21 and 22. As a result, the sticking out of the adhesive as described above could be effectively prevented.

  On the other hand, although the polymer adhesive layer 23 formed in the middle of the adhesive layer 20 is inferior in fluidity to the low molecular adhesive layers 21 and 22 as described above, it itself has fluidity. Because it is composed of an agent, it flows into the irregularities of the affixed surface when pressed or adhered to glass with an irregular surface such as polished glass or template glass, and once it flows into the irregularities, the state In order to be stable, the decorative / crime-prevention film 1 exhibiting high adhesiveness could be provided.

  Next, embodiments of the present invention will be described below.

1. Overall Configuration The decoration / security film of the present invention is a decoration / security film 1 having a total thickness of 250 to 800 μm, in which an adhesive layer 20 is formed on one surface of a base material 10 made of a resin film as shown in FIG.

2. Resin film (base material)
In the decorative and crime prevention film 1 of the present invention, the resin film used as the base material 10 is made of various known materials as long as it improves the strength of the glass adhered to such an extent that a crime prevention effect can be expected. Although it can be used, in this embodiment, a polyester film is used.

In the decoration / security film 1 of the present invention, as in the decoration / security film introduced as the above-mentioned Patent Document 1, for example, a polycarbonate substrate can be used, but polycarbonate has a linear expansion coefficient of about 7 ×. 10 ⁻⁵ / ° C is large, and therefore the problem is that it floats from the glass surface due to changes in temperature due to the difference from the linear expansion coefficient of glass (about 0.8 to 1 × 10 ⁻⁵ / ° C), and is easily peeled off. Therefore, in this embodiment, a polyester film having a lower linear expansion coefficient than that of the polycarbonate is used.

  Polyester resins (saturated polyester) include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), poly 1,4 cyclohexyldimethylene terephthalate (PCT), and polyethylene naphthalate (PEN). The type is not limited as long as a film including the above can be obtained, but in this embodiment, PET of these is used as a base material.

  The PET film used as the base material 10 in the present embodiment uses a hard coat treatment on the surface (outside surface) opposite to the surface on which the adhesive layer 20 described later is laminated. .

  The thickness of the PET film to be used is determined by how much strength is imparted to the glass, that is, the degree of safety as the decoration / security film 1. As an example, the thickness of this PET film is: The thickness is from 100 to 500 μm, preferably from 150 to 400 μm. The greater the thickness, the higher the safety.

  The PET film may be laminated by lamination.

3. The pressure-sensitive adhesive layer The pressure-sensitive adhesive layer 20 provided on the decorative / crime-prevention film 1 of the present invention can prevent protrusion during cutting or the like while maintaining high followability to the uneven surface of the glass 30, that is, fluidity. It is formed by laminating adhesives with different molecular weights so as to have shape retention.

  In order to impart the above-described properties to the pressure-sensitive adhesive layer 20, in the decoration / security film 1 of the present invention, the pressure-sensitive adhesive layer 20 is laminated on the substrate 10, and is adhered to the glass surface 30. The low molecular pressure-sensitive adhesive layers 21 and 22 made of a pressure-sensitive adhesive having a relatively low molecular weight are disposed on the side, and the low-molecular pressure-sensitive adhesive layers 21 and 22 are formed between the low-molecular pressure-sensitive adhesive layers 21 and 22. The molecular weight of the pressure-sensitive adhesive is varied in the thickness direction of the pressure-sensitive adhesive layer 20 by arranging the polymer pressure-sensitive adhesive layer 23 composed of a pressure-sensitive adhesive having a high molecular weight relative to the pressure-sensitive adhesive.

  The total thickness of the pressure-sensitive adhesive layer 20 can fill the unevenness depth (about 150 μm) on the uneven surface of the template glass, while the productivity due to the longer drying time associated with the excessive thickness. From the viewpoint of preventing the occurrence of the decrease in the pressure and the occurrence of the sticking out of the adhesive at the time of cutting, it is preferably 150 to 300 μm, more preferably 160 to 250 μm, and 200 μm in the present embodiment.

  The low molecular adhesion layers 21 and 22 and the polymer adhesion layer 23 described above attempt to equilibrate the molecular weight at the interface. As a result, the molecular weight at the interface portion is balanced over time, and the clear interface disappears. The pressure-sensitive adhesive layer 20 is integrated as a whole and has a “molecular gradient” in which the molecular weight changes with a predetermined gradient in the thickness direction.

  Due to such disappearance of the interface, it is impossible to clearly distinguish the low-molecular and high-molecular pressure-sensitive adhesive layers. This will be described as “molecular adhesive layer” and “polymer adhesive layer”.

3-1. Polymer Adhesive Layer As the adhesive (resin) constituting the polymer adhesive layer 23, a resin having a high molecular weight is used in a relative comparison with the adhesive constituting the low molecular adhesive layers 21, 22 described later.

  As the resin used as the polymer adhesive layer 23, various known materials used as an adhesive can be used. As an example, an acrylic resin (for example, 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate) can be used. Polymer). Preferably, the polymer adhesive layer is formed of a water-based acrylic emulsion resin.

  The polymer adhesive layer is prepared by blending one or more raw materials monomers or polymers with additives that are blended as desired, and polymerized by solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, etc. It can be formed by an extrusion method such as a coater drying method, a T-die method, an inflation method, or a casting method thereof.

  In addition, you may contain additives, such as an anti-aging agent, a heat conductive agent, a heat shrinkage prevention agent, a flame retardant, in a polymer adhesion layer.

3-2. Low molecular pressure-sensitive adhesive layer As the pressure-sensitive adhesive (resin) constituting the low-molecular pressure-sensitive adhesive layers 21 and 22, the polymer pressure-sensitive adhesive layer 23 on both the lamination side with respect to the base material (PET film) 10 and the adhesion side with respect to the glass 30. A resin having a low molecular weight with respect to the resin constituting the resin can be used, and various known resins that can be used as “adhesives” can be used. However, acrylic resins [eg, methyl (for example, (Meth) acrylate, ethyl (methyl) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc.).

  As this acrylic resin, those obtained by polymerizing one or more of the monomers listed as the acrylic resin in the polymer adhesive layer described above by solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, etc. Can be used.

  Additives such as tackifiers, softeners, fillers, anti-aging agents, cross-linking agents and the like can be included in the resin constituting this low-molecular pressure-sensitive adhesive layer as desired.

3-3. Combination Conditions of Low Molecular Adhesive Layer and Polymer Adhesive Layer The adhesive layer 20 in the decorative / security film 1 of the present invention is an adhesive made of the resin material constituting the low molecular adhesive layers 21 and 22 and the polymer adhesive layer 23 described above. A combination that satisfies the following conditions is selected from the agents and laminated.

  In the following description, regarding the low molecular pressure-sensitive adhesive layers 21 and 22, the low-molecular pressure-sensitive adhesive layer 21 on the substrate 20 side and the low-molecular pressure-sensitive adhesive layer 22 on the glass 30 side are both constituted by the same pressure-sensitive adhesive. As will be described, the base-side low-molecular adhesive layer 21 and the glass-side low-molecular adhesive layer 22 may be composed of different adhesives within a range that satisfies the following conditions.

(1) Material, etc. The resin constituting the polymer adhesive layer 23 and the resin constituting the low molecular adhesive layers 21 and 22 may be formed of different types of resins. It is formed of a common resin.

  In this embodiment, both the polymer adhesive layer 23 and the low molecular adhesive layers 21 and 22 are made of an acrylic resin.

(2) Molecular weight A pressure-sensitive adhesive is a resin that exhibits viscoelasticity at room temperature and flows when pressed against an adherend to exert an adhesive force. The relationship between the fluidity of the resin and the molecular weight is high when the molecular weight is high. The fluidity is poor and the fluidity improves as the molecular weight decreases.

  In the decorative / security film 1 of the present invention, paying attention to the properties of such a resin, the pressure-sensitive adhesive has a relatively low molecular weight on the lamination side with respect to the base material (PET film) 20 and the adhesion side with respect to the glass 30. The low molecular pressure-sensitive adhesive layers 21 and 22 are provided to improve fluidity and provide high adhesive force, and the low molecular pressure-sensitive adhesive layers 21 and 22 have a relatively high molecular weight, and thus have fluidity. By disposing the polymer adhesive layer 23 whose fluidity is inferior to that of the low molecular adhesive layers 21 and 22, the entire adhesive layer 20 is given shape retention so as not to impair the adhesiveness. Even when the sheet is cut, the pressure-sensitive adhesive does not protrude.

  In order to satisfy the conflicting demands of fluidity and shape retention of the pressure-sensitive adhesive layer 20, the decorative / crime-prevention film 1 of the present invention includes the pressure-sensitive adhesive constituting the low-molecular pressure-sensitive adhesive layers 21 and 22. As an example, the average molecular weight is 2,000 to 100,000, preferably 2,000 to 40,000, and the molecular weight of the resin constituting the polymer adhesive layer 23 with respect to the molecular weight of the resin constituting the low molecular adhesive layers 21 and 22 Is 5,000 to 500,000, preferably 200,000 to 300,000, so that the molecular weight of the resin constituting the polymer adhesive layer 23 is relatively high.

(3) Thickness
(3-1) Total thickness of the pressure-sensitive adhesive layer The total thickness of the pressure-sensitive adhesive layer 20 is about 150 μm in the uneven depth on the uneven surface of the template glass, and the total thickness is 150 μm so that the inside of the unevenness can be filled. In addition, if it is too thick, it is preferably 300 μm or less, more preferably 160 to 250 μm from the viewpoint of productivity loss due to the sticking out of the adhesive at the time of cutting and drying, etc. In this embodiment, it is 200 μm.

(3-2) Thickness of the polymer adhesive layer As the polymer adhesive layer 23 becomes thicker, the fluidity of the adhesive layer 20 as a whole decreases and the adhesive strength decreases. Since the shape retaining property cannot be imparted to the agent layer 20 and the sticking out of the adhesive cannot be prevented, the thickness of the polymer adhesive layer 23 is 10 to 50 μm, preferably 10 to 30 μm, more preferably 10 to 15 μm. It is preferable to use a thickness.

  In the present embodiment in which the total thickness of the pressure-sensitive adhesive layer 20 is 200 μm, the thickness of the polymer pressure-sensitive adhesive layer 23 is 10 μm.

(3-3) Low Molecular Adhesive Layer On the other hand, the thickness of the low molecular adhesive layers 21 and 22 is 50 to 145 μm, preferably 70 to 120 μm, 80 to 110 μm on the substrate (PET film) 10 side. Is preferred. In the present embodiment in which the total thickness of the pressure-sensitive adhesive layer is 200 μm, it is 80 μm.

  Further, it is more suitable if it is 50 to 120 [mu] m, preferably 70 to 120 [mu] m, 80 to 110 [mu] m on the sticking surface side to the glass. In the present embodiment in which the total thickness of the pressure-sensitive adhesive layer is 200 μm, it is preferably 70 to 120 μm, and in this embodiment it is 110 μm.

4). In the decorative / security film 1 of the present invention configured as described above, the adhesive layer 20 is formed by laminating the low molecular adhesive layers 21 and 22 and the polymer adhesive layer 23 as described above. Since it is obtained, the polymer adhesive layer 23 inferior to the low molecular adhesive layers 21 and 22 in fluidity acts as if it were a base material provided on the adhesive layer 20, so that the decorative / security film 1 Prevents sticking of adhesive when cut off.

  However, although the polymer adhesive layer 23 itself is inferior in fluidity to the low molecular adhesive layers 21 and 22, it functions as an adhesive having fluidity. Even when it is attached to a glass having an uneven surface such as polished glass or template glass, it exhibits high adhesion by exhibiting fluidity.

  Thus, when the pressure-sensitive adhesive layer 20 is formed, the molecular weight ratio between the low-molecular pressure-sensitive adhesive layers 21 and 22 and the high-molecular pressure-sensitive adhesive layer 23 and the thicknesses of the two layers are appropriately adjusted. It is possible to obtain a pressure-sensitive adhesive layer having a predetermined molecular gradient that exhibits both the properties of fluidity and shape retention required in the invention.

Test Example 1: Molecular Weight Change and Adhesive Strength-Shape Retention Characteristics Confirmation Test [Test Conditions]
The composition of each layer of the decorative / security film used is as follows.
Base material: PET film (thickness: 188 μm)
Low molecular adhesion layer: acrylic resin (molecular weight: 10,000, thickness: PET side 80μm, adherend side 110μm)
Polymer adhesive layer: Acrylic resin (thickness 10μm)

〔Test method〕
In the above decorative and crime prevention films, the molecular weight of the polymer adhesive layer was changed, and the change in adhesive strength and the shape retention of the adhesive layer (presence of protrusion when cut) were confirmed. The protrusions were confirmed visually, and the case where the protrusions were confirmed was evaluated as “×”, and the case where the protrusions were not confirmed was evaluated as “◯”.

  In the table below, “low molecular weight only (200 μm)” is a comparative example in which a low molecular pressure-sensitive adhesive alone was applied to a substrate with a thickness of 200 μm to form a pressure-sensitive adhesive layer, and the molecular weight ratio “1: 1”. Is a comparative example in which a low molecular adhesive is applied to a substrate in three portions of 80 μm, 10 μm and 110 μm, and the molecular weight of each layer is the same.

  “Initial adhesive strength” in the table below is a standard state in which a specimen cut to a width of 25 mm is bonded to an adherend (SUS plate, smooth glass, template glass) and reciprocated twice with a 2 kg roll. The result is a result of a 180 degree peel test at a speed of 300 mm / min after being left for 30 minutes, and “normal adhesive strength” is the above “initial adhesive strength” except that the standing time is 24 hours. It measured by the same method.

  As a result of the above, the decorative / crime-prevention film having the pressure-sensitive adhesive layer formed only of the low-molecular pressure-sensitive adhesive exhibited high adhesive force, but in both cases, the pressure-sensitive adhesive protruded from the cut surface.

  In contrast, in the pressure-sensitive adhesive layer in the decorative / security film of the present application, as the difference between the molecular weight of the polymer adhesive layer and the molecular weight of the low-molecular adhesive layer increases, the adhesive strength decreases. When the molecular weight of the low molecular adhesive layer is 5: 1 to 30: 1, it is possible to obtain the adhesive strength required as a decorative / security film. Almost no decrease was confirmed.

  In addition, when the molecular weight of the polymer adhesive layer is 10 times or more that of the low molecular adhesive layer, the sticking out of the adhesive at the cut portion when the decorative / crime-prevention film is cut is not so much as to cause a practical problem. In the range of 30 times, the protrusion could not be visually confirmed.

  Therefore, the molecular weight ratio of the low-molecular adhesive layer and the polymer adhesive layer is preferably 1:25 to 1:30 in order to obtain an adhesive layer that does not cause the adhesive to protrude without reducing the adhesive force. It was confirmed by the above experiment.

Test Example 2: Change in thickness and adhesive property of polymer adhesive layer [Test conditions]
The composition of each layer of the decorative / security film used is as follows.
Base material: PET film (thickness: 188 μm)
Low molecular adhesion layer: Acrylic resin (Molecular weight: 10,000)
Polymer adhesive layer: Acrylic resin (Molecular weight: 200,000)

〔Test method〕
Using the above decoration / security film, the thickness of the polymer adhesive layer is changed, and the total thickness of the adhesive layer is adjusted to 200 μm to change the adhesive force and maintain the adhesive layer. Changes in formability (presence or absence of protrusion during cutting) were confirmed.

  The protrusions were confirmed visually, and the case where the protrusions were confirmed was evaluated as “×”, and the case where the protrusions were not confirmed was evaluated as “◯”.

  Note that the measurement methods of “initial adhesive strength” and “normal adhesive strength” in the table below are the same as in Test Example 1.

  As a result of the above, in the above test example in which the total thickness of the pressure-sensitive adhesive layer was 200 μm, it was possible to prevent the pressure-sensitive adhesive from protruding while ensuring the necessary adhesive force by setting the polymer pressure-sensitive adhesive layer to 10 to 15 μm. .

  Therefore, from the above experiments, when the thickness of the polymer pressure-sensitive adhesive layer is in the range of 5 to 7.5% with respect to the total thickness of the pressure-sensitive adhesive layer, it is possible to achieve both adhesive force and shape retention. Was confirmed.

Test Example 3: Change in thickness and adhesive property of low molecular adhesive layer (attachment side) [Test conditions]
The composition of each layer of the decorative / security film used is as follows.
Base material: PET film (thickness: 188 μm)
Low molecular adhesion layer: Acrylic resin (Molecular weight: 10,000)
Polymer adhesive layer: Acrylic resin (Molecular weight: 200,000, thickness: 10μm)

〔Test method〕
Using the above decoration and crime prevention film, the thickness of the low-molecular pressure-sensitive adhesive layer is changed within the range of the total thickness of the adhesive layer to 200μm, and the adhesive force changes and the shape-retaining property of the pressure-sensitive adhesive layer (extrusion at the time of cutting) The change in the presence or absence of was confirmed.

  In addition, the protrusion was confirmed visually, and the case where the protrusion was confirmed was evaluated as “×”, and the case where the protrusion was not confirmed was evaluated as “◯”.

  Further, the measurement methods of “initial adhesive strength” and “normal adhesive strength” in the table below are the same as those in Test Example 1.

  As a result of the above, by setting the low molecular pressure-sensitive adhesive layer on the adherend side to 70 μm or more, the necessary adhesive force can be secured, and by setting it to 130 μm or less, it is possible to prevent the adhesive from sticking out. did it.

  In particular, when the thickness of the adhesion-side low molecular pressure-sensitive adhesive layer is in the range of 70 to 110 μm, extremely high adhesiveness can be secured, but no sticking out of the adhesive was confirmed.

  Therefore, from the above experiment, it was confirmed that when the thickness of the low molecular pressure-sensitive adhesive layer and the total thickness of the pressure-sensitive adhesive layer are set within a certain range, both adhesive force and shape retention can be achieved.

Test Example 4: Submerged test [Test conditions]
The composition of each layer of the decorative / security film used is as follows.
Base material: PET film (thickness: 188 μm)
Low molecular adhesion layer: Acrylic resin (Molecular weight: 10,000)
Polymer adhesive layer: Acrylic resin (Molecular weight: 200,000, thickness: 10μm)

〔Test method〕
The uneven surface of the stencil glass (vertical roughness 160) with a decorative and crime prevention film (the total thickness of the adhesive layer is 200 μm for each) with a different low molecular adhesive layer thickness on the deposition side (glass side) 180180μm), spray water with a dropper from the top of the decoration / security film, “X” if the glass and the decoration / security film were submerged, and “○” if no water was found. ".

  As a result, when the thickness of the low molecular adhesive layer on the glass side was 45 μm or less, water immersion was observed between the glass and the decorative / security film, and when the thickness was 50 μm or more, water immersion could not be confirmed.

  Therefore, it was confirmed that the adhesive completely penetrated into the irregularities on the glass surface when the thickness of the low molecular adhesive layer on the glass surface side was 50 μm or more.

Test Example 5: Change in properties of adhesive layer and change in total thickness of adhesive layer The results of confirming the change in adhesive force by changing the total thickness of the adhesive layer are shown below.
〔Test conditions〕
The composition of each layer of the decorative / security film used is as follows.
Polystyrene substrate: PET film (thickness: 188 μm)
Low molecular adhesion layer: Acrylic resin (Molecular weight: 10,000)
Polymer adhesive layer: Acrylic resin (Molecular weight: 200,000)

〔Test method〕
Using the above decoration / security film, the total thickness of the pressure-sensitive adhesive layer was changed, and the change in adhesive strength (initial adhesive strength) was confirmed.

  The following table shows the results of tests conducted on three test pieces, n1 to n3, and the average value calculated.

  The adhesive strength was measured as before.

  Adhesive strength of about 1,300g / 25mm is necessary to exert the effect as a decorative / crime-prevention film, but when the total thickness of the adhesive layer is less than 150μm, the adhesive strength, especially against the template glass It was confirmed that the adhesive strength was less than the above value.

  Such a decrease in adhesive force is that the uneven depth on the uneven surface of a typical template glass is about 150 μm maximum, so if the total thickness of the adhesive layer is less than 150 μm, It is considered that the pressure-sensitive adhesive cannot sufficiently enter the irregularities, and as a result, the necessary adhesive force cannot be obtained.

  On the other hand, as the thickness of the pressure-sensitive adhesive layer increases, the adhesive force increases. However, if the thickness of the pressure-sensitive adhesive layer is excessively increased, it takes time to dry in the manufacturing process, and the pressure-sensitive adhesive protrudes during cutting. Therefore, the total thickness of the pressure-sensitive adhesive layer is preferably 150 to 300 μm, more preferably 160 to 250 μm.

The cross-sectional enlarged view of the decoration and crime prevention film of this invention. It is explanatory drawing of the conventional decoration and crime prevention film, (A) is what thickly coated the adhesive and formed the adhesive layer, (B) is provided with a base material (acrylic foam) between the adhesive layers Example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Decoration / crime prevention film 10 Base material 10 'Surface film 20 Adhesive layer 20' Double-stick tape 21 Low molecular adhesion layer (base material side)
22 Low molecular adhesion layer (glass side)
21 ', 22' adhesive layer 23 polymer adhesive layer 24 acrylic foam 30 glass

Claims (6)

In the film to be used by providing a pressure-sensitive adhesive layer on one side of a substrate made of a resin film, and pasting the surface of the pressure-sensitive adhesive layer on a window glass,
The pressure-sensitive adhesive layer is disposed between the low-molecular pressure-sensitive adhesive layer and the low-molecular pressure-sensitive adhesive layer made of a relatively low-molecular-weight pressure-sensitive adhesive, which is disposed on the lamination side with respect to the base material and on the adhesion side with respect to the glass. A decorative / crime-preventing film, wherein the low-molecular adhesive layer is formed by laminating a polymer adhesive layer made of an adhesive having a relatively high molecular weight. The average molecular weight of the low molecular adhesive layer, 2,000 to 100,000, an average molecular weight of the pre-Symbol polymer adhesive layer, decorative, security film according to claim 1, characterized in that a 5,000～500,00 0. Wherein the total thickness of the adhesive layer and 150~300μ m, decorative, security film according to claim 1 or 2, wherein the thickness of the polymer adhesive layer was from 1 to 100 microns m. The thickness of the glass side of the low molecular adhesive layer, and 50～120Myu m, the at substrate side, decorative, security film according to claim 1 or 2, wherein it has a 50~145μ m.   The decorative / crime-prevention film according to any one of claims 1 to 4, wherein each of the polymer adhesive layer and the low-molecular adhesive layer is formed of an acrylic resin. The substrate is decorative, security film according to claim 1 to 5 any one of claims, characterized in that it uses a polyester film having a thickness 100~500μ m.

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