JP2011089012A - Adhesive film roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive film roll which hardly causes blocking when stored in a roll state, ensures little change of adhesive power immediately after sticking to an adherend and after the passage of time, is not affected by storage conditions when stored in the roll state, and has stable adhesive power in the longitudinal direction of the roll. <P>SOLUTION: The adhesive film roll is characterized in that a nonoriented polypropylene-based resin film comprising a laminate having an adhesive layer and a release layer on a surface of a base layer comprising a polypropylene-based resin is rolled up in dimensions of ≥200 m length and ≥500 mm width. An average surface roughness SRa of the release layer on the core of the film roll and an average surface roughness SRa of the release layer surface in the roll surface are ≤0.200 μm each, an average surface roughness SRa of the adhesive layer on the core of the film roll and an average surface roughness SRa of the adhesive layer in the roll surface are ≤0.030 μm each, and the absolute value of the difference between the average surface roughness SRa of the adhesive layer on the core of the film roll and the average surface roughness SRa of the adhesive layer in the roll surface is ≤0.010 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an adhesive film roll. The pressure-sensitive adhesive film roll of the present invention protects the surface of an article from undesirable effects such as dust adhesion and scratches by sticking it on the surface of an article such as a synthetic resin plate, a decorative plywood, a metal plate, and a coated steel plate. It can be particularly preferably used as a surface protective film for carrying out the process and as a surface protective film when the printed circuit board is immersed in solder. The term “adhesive film” in the present invention also means an adhesive sheet or an adhesive tape.

  Conventionally, adhesive films aimed at protecting the surface of coated materials have been used for processing, storage, transportation, etc. of building materials, electricity, electronic products, automobiles, etc. Such adhesive films have good adhesive properties. In addition, after use, the surface of the non-coated body must be easily peeled off without being contaminated with an adhesive. In recent years, adhesive films based on polyolefin resins have been used instead of adhesive films based on plasticized vinyl chloride resins. As the resin for the adhesive layer, EVA, low-density polyethylene, SIS, SEBS, and other elastomers were often used. However, because of poor heat resistance, the adhesive strength increased after heat treatment, making peeling difficult. There was a problem that the pressure sensitive adhesive remained.

  In order to solve this problem, a composition in which an amorphous olefin polymer is blended is described as a pressure-sensitive adhesive that maintains a suitable pressure-sensitive adhesive force without changing with time even under a high-temperature environment. (For example, see Patent Documents 1 and 2)

  However, the release layer is not mentioned in these adhesive films.

Moreover, the film which provided the surface layer which has specific surface roughness on the opposite surface of the adhesion layer, and improved the antiblocking property is disclosed (for example, refer patent document 3).
However, this film was not sufficient in terms of performance.

  Moreover, the problem of the external appearance by a fish eye and the blocking resistance of an adhesion layer and a base material layer are inadequate, and it is anticipated that blocking will arise depending on the storage state in a roll state.

  Moreover, although it has disclosed about the adhesive film which added the tackifier to the adhesion layer (for example, refer patent document 4), problems, such as to-be-adhered object stain | pollution | contamination in a high temperature environment, and adhesive force progress, are recognized.

JP 2006-63123 A JP 2006-257247 A JP 2008-68564 A JP 2006-335989 A

  The problem to be solved by the present invention is that blocking is less likely to occur when stored in a roll state, there is little change in adhesive force immediately after bonding to an adherend and after lapse of time, and the adhesive film is stored in a roll state. An object of the present invention is to provide a pressure-sensitive adhesive film roll that is not affected by the storage state and has a stable adhesive force in the longitudinal direction of the roll.

In view of the above problems, the present inventors have intensively studied, and as a result, when the adhesive film is stored in a roll state, the adhesive layer surface is easily affected by the opposite surface, and the adhesive force is reduced or adhered to the adherend. It has also been found that the adhesive force may change after bonding or the adhesive force may become unstable in the longitudinal direction of the roll, and the present invention has been reached.
That is, in the present invention, an unstretched polypropylene-based resin film composed of a laminate having an adhesive layer and a release layer on the surface of a base material layer composed of a polypropylene-based resin is wound with a length of 200 m or more and a width of 500 mm or more. An adhesive film roll characterized by comprising:
The average surface roughness SRa of the release layer in the roll core of the film roll and the average surface roughness SRa of the release layer surface in the roll surface are 0.200 μm or less, and the average surface of the adhesive layer in the roll core of the film roll The average surface roughness SRa of the adhesive layer on the roll surface and the roughness SRa is 0.030 μm or less, and the average surface roughness SRa of the adhesive layer in the core of the film roll and the average surface roughness of the adhesive layer on the roll surface The adhesive film roll is characterized in that the absolute value of the difference of SRa is 0.010 μm or less.

  According to the present invention, when stored in a roll state, blocking is unlikely to occur, and there is little change in adhesive force immediately after bonding to an adherend and after lapse of time, and storage is performed when the adhesive film is stored in a roll state. It is possible to obtain an adhesive film roll that is not affected by the state and has a stable adhesive force in the long state of the roll. Moreover, it has excellent processability.

  In this case, it is preferable that the difference between the adhesive force at the winding core of the film roll and the adhesive force at the roll surface is 7 cN / 25 mm or less.

  Furthermore, in this case, it is preferable that the release layer of the film is made of a resin mainly composed of propylene and has an average surface roughness SRa of 0.08 to 0.20 μm.

  Furthermore, in this case, it is preferable that the pressure-sensitive adhesive layer of the film contains a polyolefin-based elastomer and has an average surface roughness SRa of 0.005 to 0.020 μm.

  Furthermore, in this case, the absolute value of the difference between the surface roughness SRa (1) of the adhesive layer in the roll core of the film roll and the surface roughness SRa (2) of the adhesive layer in the roll surface layer is 0.007 μm or less. Is preferred.

  According to the present invention, when stored in a roll state, blocking is unlikely to occur, and there is little change in adhesive force immediately after bonding to an adherend and after lapse of time, and storage is performed when the adhesive film is stored in a roll state. It is possible to obtain an adhesive film roll that is not affected by the state and has a stable adhesive force in the longitudinal direction of the roll. In addition, it has the advantage of excellent processability.

It is a schematic diagram of a measurement sample.

  Hereinafter, embodiments of the pressure-sensitive adhesive film of the present invention will be described.

(Base material layer)
The pressure-sensitive adhesive film roll of the present invention requires a base material layer made of a polypropylene resin. Examples of the polypropylene resin used here include crystalline polypropylene, random copolymer or block copolymer of propylene and a small amount of α-olefin, and the like. More specifically, as crystalline polypropylene resin, n-heptane-insoluble isotactic propylene homopolymer used in ordinary extrusion molding or the like and polypropylene containing 60% by weight or more of propylene and others These propylene homopolymers or copolymers of propylene and other α-olefins can be used alone or in admixture.
Here, n-heptane insolubility is an indicator of polypropylene crystallinity and simultaneously indicates safety. In the present invention, n-heptane insolubility (25 ° C., It is a preferred embodiment to use one that is compatible with an elution amount of 150 pPm or less (exceeding 30 ° C. when the operating temperature exceeds 100 ° C.) when extracted for 60 minutes.

As the α-olefin copolymerization component of the copolymer of propylene and other α-olefin, α-olefin having 2 to 8 carbon atoms such as ethylene, 1-butene, 1-pentene, 1-hexene, 4 C4 or higher α-olefins such as -methyl-1-pentene are preferred.
Here, the copolymer is preferably a random or block copolymer obtained by polymerizing one or more α-olefins exemplified above with propylene.
Moreover, a melt flow rate (MFR) is 0.1-100 g / 10min, Preferably it is 0.5-20 g / 10min, More preferably, the thing of the range of 1.0-10 g / 10min can be illustrated. A range of 3.0 to 8.0 g / 10 min is particularly preferable.

The thickness of the base material layer of the present invention is preferably 5 μm or more and 100 μm or less, and more preferably 15 μm or more and 50 μm or less.
In consideration of workability such as bonding to an adherend and peeling, the adhesive film needs a certain degree of low back. When the thickness of the base material layer is less than 5 μm, there is a problem that the feeling of lower back is weakened, wrinkles, and handleability deteriorates. If it is 100 μm or more, there is a problem in terms of cost.
In order to obtain good handleability at low cost, the elastic modulus of the entire pressure-sensitive adhesive film at room temperature is preferably 300 MPa or more.
In order to satisfy these physical properties, it is preferable to use homopolypropylene for the base material layer. By using homopolypropylene, it is possible to improve the heat resistance and to provide a feeling of low back under high temperature conditions.

  Sufficient characteristics can be obtained by using commercially available crystalline polypropylene for the base material layer. The physical properties are those having a melting point of 150 to 165 ° C., a density of 0.88 to 0.92, and an elastic modulus of 1000 to 1800 MPa. Specific examples include FLX80E4 and WF836DG3 manufactured by Sumitomo Chemical Co., Ltd.

(Adhesive layer)
In addition, as a resin used for the adhesive layer, which is a requirement of the present invention, it is preferable to use an olefin polymer in order to increase the interlayer strength or to cover the film after peeling because the adhesive layer is laminated on the layer made of polypropylene resin. This is desirable from the viewpoint of preventing the adhesive layer from remaining on the body.

Furthermore, in order to satisfy the film characteristics of the present invention requirement, the adhesive layer preferably contains a polyolefin-based elastomer.
As a method for containing the polyolefin-based elastomer, it is preferable to use the resin mentioned in the following (1) or (2).

(1) A propylene block copolymer resin obtained by finely dispersing an olefin rubber in a matrix of a propylene homopolymer or a propylene-ethylene random copolymer containing a small amount of ethylene. As the olefin rubber, an ethylene-propylene random copolymer elastomer is preferable. Examples of the propylene-based block copolymer resin include “Zeras MC707” manufactured by Mitsubishi Chemical Corporation.
(2) The olefin elastomer resin was mixed with the propylene homopolymer resin or the propylene-ethylene random copolymer resin containing a small amount of ethylene so as to be 15% by weight or more and 50% by weight or less based on the total weight of the layer. thing. The olefin elastomer resin is preferably an ethylene-propylene random copolymer, and the melt flow rate is preferably in the range of 1 to 10 g / 10 min.

  Further, a small amount of a styrene elastomer such as SBS or SEBS may be added to the adhesive layer to such an extent that the adhesive layer remains on the adherend.

The average roughness SRa of the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film of the present invention needs to be 0.010 μm or more and 0.030 μm or less. Preferably, it is 0.025 μm or less, more preferably 0.020 μm or less, and particularly preferably 0.015 μm or less.
Here, when the average roughness SRa of the surface of the pressure-sensitive adhesive layer exceeds 0.030 μm, the contact area is reduced at the time of bonding to the adherend, which is not preferable because it causes a decrease in the adhesive force. One of the factors that determine the adhesive strength is the force that attracts materials, that is, the van der Waals force, on each surface of the laminated film that is in contact. Yes. Here, the fact that the contact area is small means that the attractive force between the bonded film surface and the adherend surface is reduced, which is not preferable because the adhesive force is lowered.
Moreover, it is necessary to make the surface of the adhesive layer as flat as possible, and it is preferable not to add an additive that forms surface irregularities.
On the other hand, it can be said that it is practically difficult to make the average roughness SRa of the surface of the adhesive layer less than 0.010 μm even in an unstretched film without additives.

As a method for improving the smoothness of the adhesive layer surface, in addition to using no additives as described above, the compatibility of the resin is improved, the roll surface during film production, especially a cooling roll that cools and solidifies the molten resin Examples thereof include smoothing the surface and lowering the surface temperature of the cooling roll.

The thickness of the pressure-sensitive adhesive layer of the present invention is preferably 1 μm or more and less than 30 μm.
When the thickness of the pressure-sensitive adhesive film is less than 1 μm, there are problems such as adhesive stability and insufficient strength, and when it is 30 μm or more, there are problems such as a feeling of film stiffness and blocking in a roll state.
At this time, when increasing the adhesive strength, it is preferable to increase the thickness in consideration of the viscosity. When the thickness of the adhesive layer is large, it is easy to follow the shape of the adherend surface, the contact area is easily increased, and this is particularly effective when a hard resin is used for the adhesive layer.
In terms of blocking, the thickness of the adhesive layer is preferably 2 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, and particularly preferably 2 μm or more and 10 μm or less.

(Release layer)
The pressure-sensitive adhesive film of the present invention forms a release layer on the opposite surface of the pressure-sensitive adhesive layer, but even if the pressure-sensitive adhesive films are stacked in this way, there is little blocking between the pressure-sensitive adhesive films, especially after storing the pressure-sensitive adhesive film in a roll state. Has less blocking and excellent processability.
In this case, the average surface roughness SRa is preferably 0.050 μm or more.
However, by simply increasing the roughness of the release layer, the surface irregularities of the release layer are transferred to the surface of the adhesive layer, resulting in a decrease in adhesive strength and the above-mentioned adhesion area, and bonding to the adherend. The average surface roughness SRa is preferably 0.200 μm or less because the adhesive force changes immediately after and after a lapse of time. By doing so, blocking resistance and the protection performance of a to-be-adhered body can be improved, and it becomes possible to suppress the deterioration of transparency.
At this time, the surface roughness of the release layer is preferably a surface having an average roughness SRa of 0.150 μm or less, more preferably 0.060 μm or more and 0.130 μm or less, 0.080 μm or more, 0 Most preferably, it is 130 μm or less.

  In order to form the surface irregularities as described above, for example, a layer made of a silicone resin or a fluororesin, a method of blending a polypropylene resin with a polyethylene resin or an EMMA resin, a method of mixing particles such as silica or PMMA, A layer having surface irregularities can be formed by mixing a copolymer of propylene and another α-olefin, or a mixture of these copolymer and propylene resin.

Among these methods for forming surface irregularities, silicone, EMAA, and the like have problems such as insufficient interlayer strength due to poor compatibility with olefinic resins and abnormal appearance. In addition, the method of dispersing particles in a propylene-based resin has operational problems such as performance degradation and contamination due to dropping off of particles during handling, and pressurization of a filter in an extruder during melt extrusion. On the other hand, the method of using a copolymer of another layer propylene, another α-olefin and a copolymer by coextrusion does not have the above-mentioned problem, and can provide a film having good quality and operation.
In this case, it is preferable to use a block copolymer. By using the block copolymer, the propylene matrix has a sea-island structure with the copolymer domain, and fine irregularities are formed on the surface.
Examples of the resin used for the release layer include propylene-ethylene block copolymers such as “PC480A” and “PC523A” manufactured by Sun Allomer Co., Ltd. and “BC3HF” manufactured by Nippon Polypro Co., Ltd. Further, a desired surface roughness can be obtained by blending an appropriate amount of homopropylene polymer or propylene-ethylene random copolymer with these propylene-ethylene block copolymers.
(Adhesive film roll)

  In the adhesive film roll of the present invention, the difference between the initial adhesive force at 50 ° C. and the initial adhesive force at 23 ° C. of the adhesive layer surface is preferably 10 cN / 25 mm or less, particularly preferably less than 5 cN / 25 mm. Thus, when the change in adhesive strength at high temperature is small compared to that at room temperature, the change in adhesive strength over time is small.

  The adhesive strength of the pressure-sensitive adhesive film roll of the present application is preferably in the range of 3 to 50 cN / 25 cm at 23 ° C. from the viewpoint of protective performance and peelability of the adherend. The adhesive strength can be appropriately set by controlling the amorphousness of the resin of the adhesive layer.

  In the pressure-sensitive adhesive film roll of the present invention, the thickness variation rate in the transverse direction, which is a direction orthogonal to the winding direction during film production, needs to be in the range of 2.0% to 10.0%. Preferably, it is 7.0% or less, More preferably, it is 5.0% or less. When the thickness variation rate exceeds 10.0%, when pressure-sensitive adhesive film is pressure-applied to an adherend, pressure unevenness occurs depending on the location, which causes a decrease in adhesive strength, which is not preferable. On the other hand, it can be said that it is difficult in terms of film forming technology to suppress the thickness variation rate to less than 2.0%.

The pressure-sensitive adhesive film of the present invention may contain known additives such as a lubricant, an anti-blocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light resistance agent, and an impact resistance improver as necessary. However, it is preferable that the amount is as small as possible because it causes inhibition of adhesive strength due to bleeding.
In this case, the low molecular weight substance on the surface of the adhesive layer is preferably less than 1 mg / m ² .
If it is present at 1 mg / m 2 or more, foreign matter exists between the surface of the adhesive layer and the adherend surface, which reduces the contact area and lowers the van der Waals force. In the case of adding an additive, it is necessary to select an additive such as a polymer type or to examine an addition method so that there is no transfer or transfer to the adhesive layer.

  In addition to the above requirements, the pressure-sensitive adhesive film roll of the present invention has an adhesive force in the core of the pressure-sensitive film roll and the surface of the roll by appropriately setting the pressure-sensitive adhesive force by controlling the amorphousness of the resin of the pressure-sensitive adhesive layer. For example, the difference in adhesive strength is preferably 7 cN / 25 mm or less at the initial stage, and particularly preferably less than 5 cN / 25 mm.

  The haze value of the pressure-sensitive adhesive film of the present invention is preferably in the range of 35% or less, particularly when used for an optical adherend. More preferably, it is 25% or less.

  The tensile elastic modulus of the pressure-sensitive adhesive film of the present invention is preferably 300 MPa or more in both the longitudinal and lateral directions in consideration of workability in the bonding process to the adherend, and is preferably 800 MPa or less in consideration of followability to the adherend surface. . More preferably, it is 400 to 700 MPa.

  The production method of the pressure-sensitive adhesive film roll of the present invention is not particularly limited, but after forming the base material layer and the pressure-sensitive adhesive layer using an inflation film production apparatus or a T-die film production apparatus, they are bonded together by an extrusion laminating method. Alternatively, a multilayer film may be formed by coextrusion from the beginning. Here, in order to obtain a preferable range of thickness fluctuation rate, a method of forming a multilayer film by a coextrusion method is preferable.

  The pressure-sensitive adhesive film roll obtained by cooling and solidification is lowered to a roll having a predetermined width through a slit process, and the surface hardness of the slit roll is preferably 400 or more and 700 or less. If it is less than 400, there is a fear of winding deviation, and if it exceeds 700, the shape of the surface of the release layer is easily transferred to the surface of the adhesive layer. Moreover, 500 or more and 650 or less are more preferable from the surface of the stability of the winding shape over time.

  The following examples further illustrate the invention. However, the present invention is not limited to the following examples without departing from the gist thereof. In addition, the evaluation method of the physical property in a following example and a comparative example is as follows.

(1) Tensile modulus The tensile modulus was measured under the following conditions based on the JIS K 7162 test method.
Specimen: 1A type, gripping distance: 115mm
Distance between marked lines: 50 mm
Speed: 1mm / min
Measurement temperature: 30 ° C, 100 ° C

(2) Measurement of surface roughness Using model ET-30HK manufactured by Kosaka Laboratory Co., Ltd. and analyzer TDA-21, the dimensional center plane average roughness (SRa) of the release surface and adhesive surface is as follows. Measured by the stylus method.
Radius of curvature of stylus tip: 0.5 μm
Needle pressure: 20mg
Measurement length: 1000 μm
Longitudinal magnification: 5000 times Measurement speed: 100 μm / s
Measurement interval: 2 μm
Cut-off: 80 μm

(3) Evaluation of adhesiveness It measured by the following method based on the JIS-Z-0237 (2000) adhesive tape * adhesive sheet test method.
As an adherend, an acrylic plate (Mitsubishi Rayon Co., Ltd .: Acrylite 3 mm thick) 50 mm × 150 mm is prepared, and a test piece is 25 mm in the winding direction at the time of film production and 180 mm in the direction perpendicular thereto. A piece was cut out, and using a rubber roll having a mass of 2000 g (with a spring hardness of 80 Hs on the roller surface and a width of 45 mm and a diameter (including the rubber layer) of 95 mm, covered with a rubber layer having a thickness of 6 mm), The test piece was reciprocated once at a speed of 5 mm / sec. After crimping, the initial one is left for 30 minutes in an environment of a temperature of 23 ° C. and a relative humidity of 65%, and the time left for 24 hours is 300 mm using “Tensilon” (UTM-IIIL) manufactured by Toyo Seiki Co., Ltd. The resistance value when peeled while maintaining an angle of 180 degrees at a speed of / min was defined as adhesive strength [cN / 25 mm]. At the time of measurement, a polyester sheet having a thickness of 190 μm and a size of 25 mm × 170 mm is prepared as a grip for the measurement sample, and the cellophane with a width of 15 mm is provided at the adhesive film side end of the measurement sample obtained by pressure-bonding the adhesive film and the acrylic plate. Affixed with tape and used as a grip for measurement. A schematic diagram of the measurement sample is shown in FIG. The measurement was performed three times for one sample, and the average value was defined as the adhesive strength of the sample.

(4) Film haze It measured using Nippon Denshoku Industries Co., Ltd. haze meter NDH-2000 based on the optical characteristic test method of JIS-K-7105 plastics.

(5) Evaluation of blocking resistance The adhesive film was cut out to a size of 150 mm in length and 50 mm in width, and the adhesive surface and the release surface were opposed to each other, and then subjected to a 20 kg load under a 40 ° C environment for 7 days. I put it. Thereafter, the treated adhesive film was cut into 25 mm width × 100 mm length, and when the tensile tester Tensilon UT-IIIL manufactured by Toyo Seiki was used, the adhesive surface and the release surface were peeled 180 ° at a speed of 300 mm / min. The resistance value [cN / 25 mm] was measured.

(6) High-temperature handling property Evaluation of workability was performed by the following method assuming a line for attaching and peeling the adhesive film to the adherend.
Only the sample size was changed to the A4 size by the above-mentioned adhesive evaluation method, and after the adhesive film and the acrylic plate were bonded together, heat treatment was performed at 100 ° C., and then the peelability was evaluated manually.
-Ease of pasting Evaluates workability when pasting with an acrylic board. ○: The film has sufficient waist and can be pasted easily. No wrinkling or lifting occurs when bonding.
X: The film has a low waist and tends to wrinkle and float when bonded.
-Peelability ○: Easily peelable Δ: The film is slightly deformed at the time of peeling, but there is no problem in practical use ×: The film is stretched at the time of peeling and peeling is difficult. It takes time to peel off

(7) Surface hardness of film roll Five-point winding hardness was measured in the width direction of the film roll with a paro tester (model manufactured by processq: parotester 2), and the average value was obtained.

The results obtained from the examples and comparative examples are shown in Table 1.
[Example 1]
(Creation of base material layer)
100 wt% of a homopolypropylene resin (manufactured by Sumitomo Chemical Co., Ltd .: FLX80E4, tensile elastic modulus: 1500 MPa) was melt-extruded with a 60 mmφ single-screw extruder (L / D: 22.4) to form a base layer.
(Creation of adhesive layer)
100 wt% of a polyolefin-based elastomer (Mitsubishi Chemical Co., Ltd .: Zelas MC707) was melt-extruded with a 45 mmφ twin screw extruder (L / D: 19) to form an adhesive layer.
(Creation of release layer)
50% by weight of propylene-ethylene block copolymer (Nippon Polypro: BC3HF) and 50% by weight of propylene-ethylene random copolymer (Sumitomo Chemical: WF836DG3) are melt-extruded in a 45 mmφ single screw extruder (L / D: 25). Thus, a release layer was obtained.
(Create film)
Lamination extrusion is performed in a three-layer T die (multi-manifold type, lip width 1250 mm, lip gap 1 mm) at 250 ° C. while the base material layer, the adhesive layer, and the release layer are melted in each extruder. It was. The extruded film is sprayed onto a casting roll at a temperature of 20 ° C. with an air knife, taken at a speed of 10 m / min, cooled and solidified, and a three-layer three-layer unstretched film having a substrate layer of 40 μm, an adhesive layer of 5 μm, and a release layer of 5 μm. Got.
The obtained film was made into a roll state having a width of 500 mm, a width of 500 m, and a winding hardness of 600.
The film sample of the roll core is rewound from the film roll obtained in the example, and is 10 mm from the end of the film roll core and 250 mm in length, centering on a distance of 1/2 of the film width from both ends of the film. Three samples of 350 mm are continuously cut in the longitudinal direction and measured as described above.
The film sample on the roll surface was rewound from the film roll obtained in the example, and had a length of 250 mm and a width of 350 mm centering on a distance of 1/2 of the film width from the end of the film roll and 10 m from the end of the film roll. Three samples are continuously cut in the longitudinal direction and measured as described above, and the average is obtained.
Table 1 shows the physical properties of the obtained film roll.
As a result of evaluating the properties of this film roll, it had adhesiveness at room temperature, had no blocking between the release layer and the adhesive layer, and had good handleability during high-temperature treatment.

[Example 2]
The adhesive layer resin is amorphous PP (Sumitomo Chemical: Tough selenium H3522A, crystal melting heat and crystallization heat is 28 J / g) and 50 wt% homopolypropylene resin (Sumitomo Chemical: FLX80E4, tensile elastic modulus: 1500 MPa). A film roll was produced in the same manner as in Example 1 except that the content was 50 wt%. The roll hardness of the film roll was 590. This film roll also had adhesiveness at room temperature, had no blocking between the release layer and the adhesive layer, and had good handleability during high-temperature processing.

[Example 3]
The resin for the adhesive layer was 75 wt% of polyolefin elastomer (Mitsubishi Chemical: Zelas MC707) and the resin for the release layer was 25 wt% of propylene-ethylene block copolymer (Japan polyprostyrene elastomer (JSR: DYNARON1320P)). Except for the above, a film roll was produced in the same manner as in Example 1. The film roll had a winding hardness of 600. This film roll also had adhesiveness at room temperature and had a blocking property between the release layer and the adhesive layer. There was no good handling at the time of high-temperature treatment.

[Comparative Example 1]
The resin of the release layer was the same as in Example 1 except that propylene-ethylene block copolymer (manufactured by Nippon Polypro: BC3HF) 10 wt% and propylene-ethylene random copolymer (Sumitomo Chemical: WF836DG3) 90 wt%. Thus, a film roll was produced. The roll hardness of the film roll was 590. The obtained film roll produced blocking near the core.

[Comparative Example 2]
A film roll was produced in the same manner as in Example 1 except that the resin of the release layer was 100 wt% of propylene-ethylene block copolymer (manufactured by Nippon Polypro: BC3HF). The roll hardness of the film roll was 580. On the core side of the obtained film roll, the surface roughness of the adhesive surface was high and the adhesive strength was low.

[Comparative Example 3]
As in Example 1, when an unstretched film was obtained and then a 500 mm wide and 500 m film roll was obtained, the same as in Example 1 except that the film roll had a winding hardness of 730 by increasing the winding tension. A film roll was prepared. On the core side of the obtained film roll, the surface roughness of the adhesive surface was high and the adhesive strength was low.

  The pressure-sensitive adhesive film of the present invention has little blocking between pressure-sensitive adhesive films, in particular, there is little blocking even after the pressure-sensitive adhesive film is stored in a roll state, it has excellent processability, and the adhesive force is stable over the entire length of the roll. It can be used in a wide range of application fields such as resin plates, decorative plywood, metal plates, and coated steel plates, as well as in automobile baking and printed circuit boards, and contributes greatly to the industry.

Claims (5)

An unstretched polypropylene-based resin film made of a laminate having an adhesive layer and a release layer on the surface of a base material layer made of a polypropylene-based resin is wound up with a length of 200 m or more and a width of 500 mm or more. An adhesive film roll,
The average surface roughness SRa of the release layer in the roll core of the film roll and the average surface roughness SRa of the release layer surface in the roll surface are 0.200 μm or less, and the average surface of the adhesive layer in the roll core of the film roll The average surface roughness SRa of the adhesive layer on the roll surface and the roughness SRa is 0.030 μm or less, and the average surface roughness SRa of the adhesive layer in the core of the film roll and the average surface roughness of the adhesive layer on the roll surface An adhesive film roll, wherein the absolute value of the difference in SRa is 0.010 μm or less.   It is a film roll of Claim 1, Comprising: The adhesive film roll characterized by the difference of the adhesive force in the winding core of the said film roll, and the adhesive force in the roll surface being 7 cN / 25mm or less.   The pressure-sensitive adhesive film roll according to claim 1 or 2, wherein the release layer of the film is made of a resin mainly composed of propylene and has an average surface roughness SRa of 0.08 to 0.20 µm. .   The pressure-sensitive adhesive film roll according to claim 1, wherein the pressure-sensitive adhesive layer of the film contains a polyolefin-based elastomer and has an average surface roughness SRa of 0.005 to 0.020 μm.   5. The absolute value of the difference between the surface roughness SRa of the pressure-sensitive adhesive layer in the roll core of the film roll and the surface roughness SRa of the pressure-sensitive adhesive layer in the roll surface layer is 0.007 μm or less. Film roll.