KR102020085B1 - Self-adhesive surface protection film - Google Patents

Abstract

The self-adhesive surface protection film of this invention is obtained by laminating | stacking an adhesion layer on one side of the base material layer containing polypropylene resin, and a release layer on the opposite side by coextrusion, and resin which comprises the said adhesion layer is styrene A styrene-based elastomer selected from a hydrogenated body of a block copolymer having a block-based polymer block and a butadiene-based polymer block, and the like, and a polyethylene-based resin, wherein the content of the styrene-based elastomer in the adhesive layer is 35% by mass or more and 99% by mass. % Or less, content of polyethylene-type resin is 1 mass% or more and 65 mass% or less, and the sum of the ethylene component and polyethylene-type resin in a styrene-type elastomer is 35 mass% or more and less than 70 mass% in an adhesion layer component.

Description

Self-adhesive surface protection film {SELF-ADHESIVE SURFACE PROTECTION FILM}

The present invention relates to an adhesive film. The adhesive film of this invention is a member, such as a prism sheet used for optical uses, a synthetic resin board (for building materials), a stainless steel plate (for building materials, for example), an aluminum board, a cosmetic plywood, a steel plate To protect the surfaces of glass plates, home appliances, precision machines, and automotive bodies during manufacture, to protect against scratches when the articles are stacked, stored, transported, or conveyed in the manufacturing process, and the second process of the article. It can use suitably when protecting from the damage | wound generate | occur | produced at the time of cut | disconnection (for example, bending process or press work).

Conventionally, the adhesive film for the surface protection of a coating body is used at the time of processing, storage, and transportation of building materials, electrical, electronic products, automobiles, etc. These adhesive films have good adhesiveness, and after each use, It should be easy to peel off without contaminating the surface with adhesive.

In recent years, the above-mentioned coating body has been diversified, and it can be seen that not only the coated surface is smooth but also have surface irregularities. As a coating body which has surface asperity, the prism type lens part of the prism sheet used for the optical member, etc. are mentioned, for example. In order to express sufficient adhesive force in use with respect to the coating body having surface irregularities such as a prism sheet, it is conceivable to increase the adhesive force of the adhesive layer so that the adhesive force is obtained even if the contact area is small.

In order to increase the adhesive force of the adhesive layer, it is possible to use a styrene-based elastomer or the like which shows high adhesive force as the resin as a main component.However, if the adhesive force of the adhesive layer is increased, the film is stored in a roll state, and then blocking occurs when the film is unwound. A problem arises such that the film is partially stretched or deformed.

As the countermeasures described above, fluorine-based resins, silicone-based resins (see, for example, Patent Document 1, etc.), ultrahigh-molecular polydimethylsiloxane (see, for example, Patent Document 2, etc.), saturated fatty acid bisamides (e.g., For example, although the examination of adding patent document 3 etc.) is performed, these resins may transfer to an adhesion layer when they are all stored in roll state, and the adhesive force may be reduced, or a coating body may be contaminated. You can't wash away your concerns.

Moreover, although addition of polyethylene-type resin to an adhesion layer is also examined (for example, refer patent document 4, patent document 5, etc.), it is the adhesive force with respect to a prism, and the film is kept in roll state, and the film is made after that, Not all of the above problems were solved when solved.

Japanese Patent Laid-Open No. 2008-81589 Japanese Patent Laid-Open No. 2008-308559 Japanese Patent No. 4565058 Japanese Patent Publication No. 08-73822 Japanese Patent Laid-Open No. 2007-161882

The problem to be solved by the present invention is to exhibit a strong adhesion to the coating, can be used in various coatings, while storing the adhesive film in a roll state, the film is partially stretched or deformed even when the film is released thereafter. It is hard to generate | occur | produce the problem, such as that, and provides the self-adhesive surface protection film excellent in the processing ability of a film.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors discovered that the said subject can be eliminated by making the kind and compounding ratio of resin used for an adhesion layer into a predetermined range, and reached | attained this invention.

That is, the present invention is obtained by laminating an adhesive layer on one side of a substrate layer containing polypropylene resin and a release layer on the opposite side by coextrusion, and the resin constituting the adhesive layer is a styrene elastomer and polyethylene. A block copolymer comprising at least a resin, wherein the styrene-based elastomer has a hydrogenated product of a block copolymer having a styrene-based polymer block and a butadiene-based polymer block, or a block copolymer having a styrene-based polymer block and a random copolymer block of styrene and butadiene Is a hydrogenated product, the polyethylene-based resin is an ethylene homopolymer and / or an ethylene-α-olefin copolymer, and the content of the styrene-based elastomer in the adhesive layer is 35% by mass or more and 99% by mass or less, and the content of the polyethylene resin It is 1 mass% or more and 65 mass% or less, the ethylene component and polyethylene type in a styrene-type elastomer Fingers sum is directed to a self-adhesive surface protective film, characterized in that less than 70% by mass to 35% by weight of the adhesive layer components.

According to the present invention, while exhibiting a strong adhesion to the coating, can be used for a variety of coatings, while storing the adhesive film in a roll state, the film is partially stretched or deformed even when the film is released thereafter. Hardly arises, and the self-adhesive surface protection film excellent in the processability of a film can be obtained.

In this case, it is preferable that the bending elastic modulus of ethylene resin used for an adhesion layer is 10 Mpa or more and less than 90 Mpa.

Moreover, in this case, it is suitable that MFR (190 degreeC, 2.16 kgf) of polyethylene-type resin in the said adhesion layer is 0.5-8 g / 10min.

Moreover, in this case, it is suitable that MFR (230 degreeC, 2.16 kgf) of the styrene-type elastomer in the said adhesion layer is 0.5-8 g / 10min.

Moreover, in this case, it is suitable that MFR (230 degreeC, 2.16 kgf) of the polypropylene resin in the said base material layer is 1.0-15 g / 10min.

While the pressure-sensitive adhesive film according to the present invention exhibits strong adhesion to the coating body and can be used for various coatings, the adhesive film is stored in a roll state, and then the film is partially stretched or deformed even when the film is released thereafter. This problem is unlikely to occur, and has the advantage of being excellent in processing ability of the film.

1 is a schematic diagram of a measurement sample.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the adhesive film of this invention is described.

(Base layer)

The adhesive film of this invention requires the base material layer which has polypropylene resin as a main component. As a polypropylene resin used here, random copolymerization, a block copolymer, etc. of crystalline polypropylene, propylene, and a small amount of alpha olefin are mentioned. More specifically, examples of the crystalline polypropylene resin include n-heptane insoluble isotactic propylene homopolymers or copolymers of propylene containing 60% by mass or more of propylene and other α-olefins used in ordinary extrusion molding. have. This propylene homopolymer or the copolymer of propylene and another alpha olefin can be used individually or in mixture.

It is preferable that 60 mass% or more of propylene units are contained in a base material layer, Furthermore, it is preferable that 70 mass% or more, More preferably, it is 80 mass% or more, Especially preferably, 90 mass% or more is contained. When the propylene unit is less than 60% by mass, the film may have no elasticity, and handling may be difficult. When the amount of propylene units is less than 60% by mass, or when polyethylene-based resin is used, the film tends to be flexible and elongated, and the film tends to be partially elongated or deformed even when the film is unwound.

Here, n-heptane insolubility indicates the crystallinity of polypropylene and shows safety. In the present invention, n-heptane insolubility according to the Ministry of Health, Welfare, and Published Notice No. 20 (25 ° C, extracted for 60 minutes) It is a preferable form to use the thing suitable for an elution content of 150 ppm or less (it is 30 ppm or less for the use temperature to exceed 100 degreeC)).

As the α-olefin copolymer component constituting the copolymer of propylene and other α-olefins, α-olefins having 2 to 8 carbon atoms, for example, ethylene or 1-butene, 1-pentene, 1-hexene, 4-methyl- C4 or more alpha-olefins, such as 1-pentene, are mentioned. It is preferable that a copolymer is a random or block copolymer obtained by superposing | polymerizing 1 type (s) or 2 or more types of the above-mentioned alpha olefin to propylene.

In addition, the copolymer of propylene and another alpha olefin can also be used individually or in mixture of 2 or more types.

The melt flow rate (melt flow rate (MFR): 230 ° C., 2.16 kgf) of the polypropylene resin to be used is preferably in the range of 1.0 to 15 g / 10 minutes, more preferably in the range of 2.0 to 10.0 g / 10 minutes.

Moreover, the waste film which came out at the time of product processing the film obtained by this invention can be reassembled as a recovery raw material, and can also be added to a base material layer. By using a recovered raw material, it is possible to suppress a production cost.

(Adhesive layer)

The adhesive layer which concerns on this invention needs to contain a styrene-type elastomer in order to express high adhesive force. Moreover, in order to express adhesive force and the film feeding property from a roll state, an adhesion layer needs to contain polyethylene-type resin. By adding polyethylene resin, the peeling force with respect to a mold release surface can be reduced from the adhesive surface side. Moreover, tackifying resin other than polyethylene-type resin, a softener, polystyrene, etc. can also be mixed with an adhesion layer as needed for control of adhesive force.

The amount of styrene-based elastomer in the adhesive layer needs to be 35 mass% or more and 99 mass% or less with respect to 100 mass% of adhesive layer components in order to express high adhesive force and film extractability from a roll state. If it is less than 35 mass%, adhesive force will fall and it will become difficult to obtain the adhesive force required. The amount of styrene elastomers in the adhesive layer is preferably in the range of 38% by mass or more and 95% by mass or less. More preferably, it is 40 mass% or more and 90 mass% or less.

As a styrene-type elastomer, Hydrogenated substance of ABA type block polymers, such as a styrene-butadiene-styrene copolymer, Hydrogenated substance of AB type block polymers, such as a styrene-butadiene copolymer, Styrene-type random copolymers, such as styrene-butadiene rubber And hydrogenated substance. In addition, a partial hydrogenated body may be sufficient as this hydrogenated body, and a complete hydrogenated body may be sufficient as it.

It is preferable that the styrene component in a styrene-type elastomer is 5 mass% or more and 40 mass% or less. When it is less than 5 mass%, granulation at the time of resin preparation becomes difficult, and when it exceeds 40 mass%, adhesive force may fall, and it may become difficult to obtain the adhesive force required. The styrene component in the styrene-based elastomer is preferably in the range of 8% by mass to 35% by mass, and more preferably in the range of 10% by mass to 30% by mass.

On the other hand, it is preferable that the ethylene component in a styrene-type elastomer is 15 mass% or more and 70 mass% or less. The ethylene component in the styrene-based elastomer has the effect of increasing the compatibility with the polyethylene-based resin, and also has the effect of increasing the film extractability from the roll state. Therefore, when the amount of ethylene components is large, it is considered that the effect of improving feeding ability will tend to be large. Moreover, it is thought that the ethylene component in a styrene-type elastomer has contributed also greatly to the expression of adhesive force, and when the amount of ethylene components exceeds 70 mass%, there exists a possibility that the adhesive force of an adhesion layer may become high too much.

Moreover, it is preferable that a butylene component exists in styrene-type elastomer. When a butylene component is 50 mass% or more, when polyethylene-type resin is added, there exists a tendency for adhesive force to become difficult to fall and it is preferable.

The melt flow rate (MFR: 230 ° C., 2.16 kgf) of the styrene-based elastomer to be used is preferably in the range of 0.5 to 8 g / 10 minutes, more preferably in the range of 2.0 to 7.0 g / 10 minutes, from the viewpoint of film forming properties.

The amount of polyethylene-based resin in an adhesion layer needs to be 1 mass% or more and 65 mass% or less in order to express high adhesive force and film extractability from a roll state. When the amount of polyethylene resin in an adhesion layer exceeds 65 mass%, adhesive force falls and it becomes difficult to obtain the adhesive force required. The polyethylene resin amount in an adhesion layer becomes like this. Preferably it is 3 mass% or more and 60 mass% or less.

As polyethylene-type resin, the copolymer of low density polyethylene, ethylene, and (alpha) -olefin, etc. are mentioned. Among these, low-density polyethylene, especially linear low-density polyethylene called LLDPE, and ultra-low-density polyethylene called VLDPE are preferable, since the feeding property of a film can be improved, maintaining adhesive force. These copolymerize short chain branching into the ethylene chain by copolymerizing an alpha olefin, and can provide flexibility to polyethylene-type resin by the kind and copolymerization amount of an alpha olefin.

As alpha-olefin, 1-butene, 1-pentene, 1-hexene, 4-methyl-1- pentene, 1-octene, etc. are mentioned.

In the adhesion layer which concerns on this invention, the sum of the ethylene component and ethylene resin in a styrene-type elastomer is a range of 35 mass% or more and less than 70 mass% in an adhesion layer component. When the sum of an ethylene component and ethylene resin is 70 mass% or more in an adhesion layer component, adhesive force falls and sufficient adhesive force is not obtained. When the sum total of an ethylene component and ethylene resin is less than 35 mass% in an adhesion layer component, the peeling force with respect to the mold release layer of a film adhesion layer will become high. Preferably, the sum of an ethylene component and ethylene resin is 40 mass% or more and less than 70 mass% in an adhesion layer component. More preferably, the sum of an ethylene component and ethylene resin is 45 mass% or more and 65 mass% or less in an adhesion layer component. Especially preferably, the sum of an ethylene component and ethylene resin is 45 mass% or more and 63 mass% or less in an adhesion layer component.

It is preferable that the bending elastic modulus of polyethylene-type resin is 10 MPa or more and less than 90 MPa. If it is less than 10 MPa, the film feeding property from a roll state will fall, and if it is 90 MPa or more, an adhesive layer will become hard and there exists a tendency for adhesive force to fall. Bending elastic modulus of polyethylene-type resin becomes like this. Preferably it is the range of 15 MPa-80 MPa, More preferably, it is the range of 20 MPa-70 MPa.

In order to make bending elastic modulus into the said range, it is one measure to adjust the ethylene component in polyethylene-type resin. From such a viewpoint, it is preferable that the ethylene component in polyethylene-type resin is 70 mass% or more. As for the ethylene component of polyethylene-type resin, it is more preferable that it is 75 mass% or more, More preferably, it is 80 mass% or more. Moreover, 98 mass% or less of the ethylene content of polyethylene-type resin is preferable, More preferably, it is 96 mass% or less, More preferably, it is 95 mass% or less, Especially preferably, it is 94 mass% or less. When the ethylene component in polyethylene-type resin is less than 70 mass%, there exists a tendency for the film extractability improvement effect from a roll state to become small. As an example of the polyethylene resin whose ethylene component in polyethylene-type resin is 70 mass% or more, CX3007, VL100, etc. by Sumitomo Chemical Co., Ltd. are mentioned.

The density of the polyethylene resin is preferably 850 kg / m 3 to 920 kg / m 3, further preferably 860 kg / m 3 to 910 kg / m 3, particularly preferably 870 kg / m 3 to 908 kg / m 3, most preferably 880 kg. / M 3 to 906 kg / m 3. By setting it as the said range, it becomes easy to make favorable adhesiveness and drawability compatible.

The melt flow rate (MFR: 190 ° C., 2.16 kgf) of the polyethylene resin to be used is preferably in the range of 0.5 g / 10 min to 8 g / 10 min, and more preferably in the range of 0.8 g / 10 min to 7.0 g / 10 min. Do. By setting it as the said range, the film forming which made thickness of each layer uniform can be performed easily.

The adhesion layer may contain polyolefin resin other than polyethylene resin, The kind is not specifically limited, For example, copolymerization of crystalline polypropylene, propylene, and a small amount of alpha-olefins, etc. are mentioned. Generally, since this resin tends to fall easily even if it mix | blends only a small amount normally, it is preferable to mix | blend in 1 to 20 mass% ratio.

As tackifying resin, an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, a terpene resin, a coumarone indene resin, a styrene resin, rosin resin, etc. are mentioned, for example. The molecular weight of the tackifying resin is not particularly limited and can be appropriately set. However, when the molecular weight is small, there is a possibility that material transfer to the coating from the pressure-sensitive adhesive layer, heavy peeling, or the like may occur. There is a tendency to lack enhancement effects. Therefore, it is preferable that the number average molecular weight of tackifying resin is about 1000-100,000. The number average molecular weight can be measured by gel permeation chromatography (standard material: polystyrene) or the like.

The compounding quantity of tackifying resin in an adhesion layer becomes like this. Preferably it is 5 mass% or more and 20 mass% or less with respect to 100 mass% of adhesion layer components. When the compounding quantity of tackifying resin is more than 20 mass%, since tackifying resin is low in molecular weight, melt viscosity becomes extremely low and the base material layer which uses polypropylene resin as a main component when carrying out coextrusion film forming using T die etc. In addition to being difficult to laminate, the pressure-sensitive adhesive layer tends to be sticky, and the film feeding property from the rolled state tends to be difficult to be improved. Moreover, even if it mix | blends if the compounding quantity of tackifying resin in an adhesion layer is less than 5 mass%, it is hard to contribute to the adhesive force change of an adhesion layer. Therefore, the compounding quantity of tackifying resin becomes like this. Preferably it is 6 mass% or more and 20 mass% or less. More preferably, it is the range of 6 mass% or more and 15 mass% or less.

When melt viscosity tends to fall by addition of tackifying resin to an adhesion layer, melt viscosity difference between a base material layer and an adhesion layer is improved by adding about 1 mass%-about 15 mass% of polystyrene resin to an adhesion layer. Can be easily laminated. Polystyrene resin compounding quantity becomes like this. Preferably it is 3 mass% or more and 12 mass% or less, More preferably, it is 5 mass% or more and 10 mass% or less.

As a softener, a low molecular weight diene polymer, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, derivatives thereof, polybutene, etc. are mentioned, for example. The molecular weight of the softener is not particularly limited and can be appropriately set. However, when the molecular weight is small, there is a concern that it may cause material migration or heavy peeling to the coating from the adhesive layer. There is a tendency to lack. Therefore, the number average molecular weight of the softener is preferably about 1000 to 100,000. A number average molecular weight can be measured by the method similar to the case of tackifying resin.

In addition, the tackifying resin and the softening agent used for an adhesion layer are liquids and powders depending on a kind, and some may dirty an extruder at the time of extrusion. This problem is improved by using a tackifying resin or a softener in a master batch with a polyethylene resin or a polyolefin resin. Therefore, it is preferable to use tackifying resin and a softener masterbatching with polyethylene resin or polyolefin resin.

When the adhesive force of the adhesive film (adhesive layer) of this invention is in the range of 200 cN / 25 mm-1000 cN / 25 mm with respect to an acryl plate at 23 degreeC, it is preferable to consider using it for various coating bodies. If the adhesive force is less than 200 cN / 25 mm, the coating may be turned off during protection depending on the coating material, and thus, it may not function as a protective film. On the other hand, when adhesive force is more than 1000 cN / 25mm, when peeling a film from a coating body, there exists a possibility that it may not peel smoothly.

Moreover, in 23 degreeC, it is preferable considering that it uses the thing of the range of 2cN / 25mm-20cN / 25mm with respect to a prism sheet. When adhesive force is less than 2 cN / 25 mm, it may turn over at the time of protection, and cannot function as a protective film. On the other hand, when adhesive force is more than 20 cN / 25mm, when peeling a film, there exists a possibility that it may not peel smoothly. An adhesive force can be set suitably by changing resin composition, thickness, etc. of an adhesion layer.

In the adhesion layer which concerns on this invention, a well-known additive can also be contained as needed. For example, a lubricating agent, an antiblocking agent, a heat stabilizer, antioxidant, an antistatic agent, a light resistant agent, an impact resistance improvement agent, etc. can also be contained. However, these components are comparatively low in molecular weight, and may bleed out to the adhesion layer surface, and may reduce the adhesive force of an adhesion layer. Therefore, when using an additive, it is desirable to make the amount of low molecular weight substances on the adhesion layer surface less than 1 mg / m <2>.

The measurement of the low molecular weight substance on the adhesion layer surface was performed in the following procedure. The adhesive layer which wash | cleaned the surface of the adhesion layer using the organic solvent which does not corrode resin which comprises adhesive layers, such as ethanol, removes the organic solvent from the washing | cleaning liquid with an evaporator, etc., and washes the numerical value calculated | required by measuring the residue. It was calculated by dividing the surface area of the surface. When the residue is 1 mg / m 2 or more, foreign matter exists between the surface of the adhesive layer and the surface of the coating body, which decreases the contact area with the coating body, and causes the van der Waals force to be lowered. Not preferred. When adding an additive, it is necessary to select additives, such as a polymer type, to examine the addition amount and the addition method, and to prevent transfer and transfer of the low molecular weight substance (foreign substance) to the adhesion layer.

(Release layer)

The adhesive film of this invention has a release layer on the opposite surface to the adhesive layer laminated | stacked on the single side | surface of a base material layer. Thereby, even if the adhesive films overlap, it can suppress that blocking of adhesive films arises. By forming a mold release layer, especially when the adhesive film is stored in a roll state, when the film is unwound afterwards, problems such as partial elongation or deformation of the film are unlikely to occur, and thus a film having excellent workability can be obtained. In order to prevent the blocking of the adhesive films even when the adhesive films overlap, it is effective to form surface irregularities in the release layer and to reduce the contact area with the adhesive layer.

It is preferable that a mold release layer uses polypropylene resin as a main component (about 50 mass% or more). As a specific polypropylene resin, a propylene ethylene block copolymer etc. are mentioned.

In order to form the above-mentioned surface irregularities in a release layer, it is effective to mix incompatible resin with polypropylene resin. By doing so, a rough surface layer can be formed in a mat form. Moreover, when using a propylene ethylene block copolymer as polypropylene resin, the same effect can be anticipated, without using incompatible resin for polypropylene resin. It is of course also possible to further add incompatible resin to the propylene-ethylene block copolymer to the polypropylene resin.

As a resin incompatible with polypropylene resin, a C4 or more alpha-olefin (co) polymer, such as a low density polyethylene and 4-methylpentene- 1-type (co) polymer, is used suitably. In addition, linear low-density polyethylene, high-density polyethylene, copolymers of ethylene and a small amount of α-olefins, copolymers of ethylene and vinyl acetate, polystyrenes, polyester resins, polyamide resins, and the like can be given. In particular, when 4-methylpentene-1 (co) polymer is used, not only the surface of the release layer is roughened in the form of a mat, but also the surface free energy of the film surface is lowered, whereby further improvement in peelability can be expected. .

In view of the resin composition of the pressure-sensitive adhesive layer of the present invention, the three-dimensional average surface roughness SRa of the surface of the release layer is preferably 0.10 µm or more and 0.50 µm or less. By doing so, the blocking resistance and the protection performance of a coating body can be improved. When the surface roughness of a mold release layer is lower than 0.10 micrometer, the film feeding property at the time of making a film into a roll form may worsen. When the surface roughness of a mold release layer becomes higher than 0.50 micrometer, the surface asperity of a mold release layer may transfer to the surface of an adhesion layer, and adhesive force may fall remarkably. At this time, as for the surface asperity of a mold release layer, it is more preferable to set it as the surface used as 0.25 to 0.45 micrometer in surface average surface roughness SRa.

In addition, the three-dimensional average surface roughness SRa of the surface of a release layer means the average roughness in the center plane at the time of approximating a surface roughness curve by a sinusoidal curve, and can measure it with a surface roughness measuring apparatus.

(Self-adhesive surface protection film)

The self-adhesive surface protection film of this invention is comprised from each layer of the base material layer, an adhesion layer, and a release layer containing the said resin component. It is preferable that the thickness of the self-adhesive surface protection film of this invention is 10 micrometers or more and 150 micrometers or less, More preferably, they are 15 micrometers or more and 120 micrometers or less, More preferably, they are 20 micrometers or more and 100 micrometers or less. If the total thickness of the film is too thin, the handleability may be inferior. If the thickness is too thick, the rigidity may be increased, the handleability may be poor, and the film may be disadvantageous in terms of cost.

It is preferable that the thickness of the base material layer of this invention is 5 micrometers or more and less than 100 micrometers, It is more preferable that they are 10 micrometers or more and 75 micrometers or less, It is further more preferable that they are 15 micrometers or more and 55 micrometers or less. If the thickness of the base material layer is less than 5 µm, the elasticity is weakened, wrinkles or the like tend to occur when adhered to the coating as a protective film, and there is a problem that adhesive strength cannot be sufficiently obtained. If the thickness is 100 µm or more, the film is disadvantageous in terms of cost.

It is preferable that the thickness of the adhesion layer of this invention is 1 micrometer or more and less than 30 micrometers. If the thickness of an adhesion layer is less than 1 micrometer, the stable film forming by coextrusion will become difficult, and if it is 30 micrometers or more, it will become a film which is disadvantageous in terms of cost. At this time, when increasing adhesive force, it is preferable to consider the viscosity and to enlarge the thickness of an adhesion layer. By increasing the thickness of the pressure-sensitive adhesive layer, the contact area with the coating body tends to increase. It is preferable that the thickness of an adhesion layer is 2 micrometers or more and 20 micrometers or less, Furthermore, 3 micrometers or more and 15 micrometers or less are preferable, and 4 micrometers or more and 8 micrometers or less are especially preferable.

It is preferable that the thickness of the mold release layer of this invention is 1 micrometer or more and less than 30 micrometers. If the thickness of a mold release layer is less than 1 micrometer, the stable film forming by coextrusion will become difficult, and if it is 30 micrometers or more, it will become a film which is disadvantageous in terms of cost. It is preferable that the thickness of a mold release layer is 2 micrometers or more and 20 micrometers or less, and also 3 micrometers or more and 15 micrometers or less are preferable.

It is preferable that the peeling force with respect to the adhesive surface mold release surface of the adhesive film of this application is 250 cN / 40 mm or less in 23 degreeC from the point of film extractability at the time of making an adhesive film into a roll form. When the peeling force exceeds 250 cN / 40 mm, a problem arises such that the film is partially elongated or deformed in film feeding when the pressure-sensitive adhesive film is in roll form. More preferably, it is 200 cN / 40 mm or less. In addition, the minimum of peeling force with respect to the mold release surface of the adhesive face of an adhesive film is about 1 cN / 40 mm, Furthermore, about 5 cN / 40 mm as a realistic value.

The self-adhesive surface protection film of this invention is comprised from each layer of the base material layer, an adhesion layer, and a release layer containing the said resin component, The resin which comprises each layer uses a single axis | shaft, a biaxial extruder, etc., for example. In the molten state, it is sent to a feed block type or multi-manifold type T die, and is obtained by laminating and extruding three or more layers (base layer, adhesive layer, and release layer). The extruder temperature of each layer may be suitably adjusted in consideration of the molding temperature of the component used in each layer in order to bring each layer into a molten state, and may be adjusted, for example, in the range of 200 ° C to 260 ° C. The temperature of the T die may be the same as the above temperature. The take-out speed from the T die to the casting roll may be any speed at which each layer becomes a suitable thickness, for example, 10 m / min to 200 m / min, preferably 10 m / min to 100 m / min.

It is suitable on the handling that the adhesive film of this invention is made into the form of a roll. Although the upper limit of the width | variety and winding length of a film roll is not restrict | limited especially, Ease of handling is generally 5000 m or less in width 1.5 m or less and winding length is preferable in the case of film thickness of 40 micrometers. Moreover, as a winding core, the plastic core and metal cores, such as 3 inches, 6 inches, and 8 inches, can be used normally. Moreover, it is preferable that it is a film roll wound by the dimension of 200 m or more in length and 450 mm or more in width from the aptitude of processing.

The adhesive film of this invention is a member, such as a prism sheet used for optical uses, a synthetic resin board (for building materials), a stainless steel plate (for building materials, for example), an aluminum board, a makeup plywood, a steel plate, In order to protect the surface of glass plates, home appliances, precision machines, and automobile bodies during manufacturing, to protect against scratches when the articles are laminated, stored, transported, or transported in the manufacturing process, and the articles are subjected to secondary processing. It can be used in the case of protecting from scratches during (for example, bending or pressing).

This application claims the benefit of priority based on Japanese Patent Application No. 2012-89184 for which it applied on April 10, 2012. The entire contents of the specifications of Japanese Patent Application No. 2012-89184, filed April 10, 2012, are incorporated herein by reference.

Example

Next, an Example is given and this invention is demonstrated again. However, this invention is not limited to a following example, unless the summary is deviated. In addition, the evaluation method of the physical property in a following example and a comparative example is as follows.

(1) Evaluation of adhesiveness

It measured by the following method based on JIS-Z-0237 (2000) adhesive tape and an adhesive sheet test method.

As a coating body, an acryl plate (made by Mitsubishi Rayon Co., Ltd .: 3 mm thickness of acrylic light (registered trademark)) 50 mm x 150 mm, and a prism sheet (lens part contains a triangular prism, the height of a triangular prism is 25 micrometers, a triangle) The width of the prism was prepared 50 mm x 150 mm). As a test piece, the test piece of the size of 25 mm was cut out in the winding direction at the time of film manufacture, and the direction orthogonal to it.

The coating body and the test piece were 5 mm / w using a 2000 g rubber roll (with a spring hardness of 80 Hs on the surface of the roller and a thickness of 45 mm and a diameter (including a rubber layer) of 95 mm coated with a rubber layer of 6 mm). One reciprocation was pressed at the speed of seconds. After crimping | bonding, the thing left to stand for 30 minutes in the environment of the temperature of 23 degreeC, and 65% of the relative humidity is 300 mm / min using "Autograph (trademark)" (AGS-J) made by Shimadzu Corporation The resistance value at the time of 180 degree peeling was made into adhesive force [cN / 25mm]. 180 degree peeling means maintaining the peeling angle of an acryl plate and a film at the time of measuring the resistance value at the time of peeling at 180 degree | times.

At the time of measurement, a 190-micrometer-thick polyester sheet of size 25mm * 170mm was prepared as a holding part of a measurement sample, and the width | variety of an adhesion part 15mm is attached to the edge of the test piece side of the measurement sample which crimped | bonded the said test piece and an acrylic plate. Thus, the said polyester sheet was affixed with the cellophane tape, and it was set as the holding part at the time of a measurement. The schematic diagram of a measurement sample is shown in FIG. The measurement was performed about three samples produced from each film manufactured by the Example and the comparative example, and made the average value the adhesive force of the sample. In the case of a prism sheet, it measured similarly.

(2) evaluation of peeling force

Acrylic board (made by Mitsubishi Rayon Co., Ltd .: 3 mm thickness of acrylite (registered trademark)) A double-sided adhesive tape (manufactured by Nitto Denko) is attached to the entire surface of 50 mm × 150 mm, and the other side of the double-sided adhesive tape The test piece of 150 mm (winding direction at the time of film manufacture) x 50 mm (direction orthogonal to the winding direction at the time of film manufacture) was affixed so that the adhesive surface of a test piece might come to.

As a new test piece, a test piece having a length of 150 mm in the winding direction at the time of film production and a size of 40 mm in the direction orthogonal to it was cut out and attached to the adhesive face and the acrylic plate through a double-sided adhesive tape. After superposing a mold release surface, it mold-releases using the mass 2000g rubber roll (45 mm in width, 95 mm in diameter (including a rubber layer), covered with the rubber hardness of the spring surface 80Hs of a roller surface, 6 mm of thickness). The cotton and the test piece were crimped 1 round tripping at the speed of 5 mm / sec. After crimping, a load of 60 kg was applied to a total area 4000 mm2 of 100 mm in the winding direction and 40 mm in the direction orthogonal thereto, and left to stand at a temperature of 40 ° C. and a relative humidity of 65% for 24 hours, followed by cooling to 23 ° C. Peeling force [cN / 40mm] of resistance value when peeling 180 degree | times at the speed | rate of 300 mm / min using "Autograph (registered trademark)" (AGS-J) made by Shimadzu Corporation ].

At the time of measurement, a 190-micrometer-thick polyester sheet of size 40mm x 170mm was prepared as a holding part of a measurement sample, and it adhere | attached by the cellophane tape in the width | variety of 15 mm of adhesive parts at the end of a 150 mm x 40 mm test piece It was set as the grip part at the time of a measurement. The measurement was performed three times with respect to one sample, and the average value was made into the peeling force of the sample.

(3) drawability from roll

After the winding body of 550mm width and 500m winding was obtained by a slit, it stored for 7 days in roll state under the light shielding environment of the temperature of 23 degreeC, and 75% of humidity. Immediately after rewinding the film roll after storage to another plastic core (diameter 9 cm) 300m, the film edge part was gripped by hand, and it tensioned and rewinded 3m. When rewinding, it was visually confirmed whether there was a partial elongation or deformation in the film. ○ (good) that did not have partial elongation or deformation, and × (defect) which had partial elongation or deformation.

(4) MFR measurement of resin

Measurement was performed based on JIS-K7210.

(5) Measurement of bending elastic modulus of resin

The measurement was performed in accordance with ASTM D747-70.

(6) Measurement of Ethylene Components in Styrene-Based Elastomers

Approximately 330 mg of the resin sample was dissolved in heavy chloroform and measured by ¹³ C-NMR (BRUKER, AVANCE500). From the obtained measurement result, the amount of ethylene components in styrene-type elastomer was identified.

Example 1

(Production of base material layer)

100 mass% of homopolypropylene resins (made by Sumitomo Chemical Co., Ltd .: FLX80E4, 230 degreeC MFR: 7.5 g / 10min) were melt-extruded at 240 degreeC by the 90 mm diameter single screw extruder, and it was set as the base material layer.

(Production of adhesive layer)

Styrene-type elastomer (hydrogenated body of block copolymer of styrene and butadiene, product made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) 40 mass% and ethylene-α olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd .: CX3007, 190 ° C MFR: 3.7 g / 10 min, modulus of elasticity: 26 MPa) 50 mass% and a petroleum resin (Arakawa Chemicals: Alcon (registration) 10 mass% of P125) was melt-extruded at 210 degreeC with the 45 mm diameter single screw extruder, and it was set as the adhesion layer.

(Production of release layer)

90 mass% of propylene ethylene block copolymers (BC3HF made from Nippon Polypropylene) and 10 mass% of low-density polyethylene resin (Ube high acid agent: R300) were melt-extruded at 230 degreeC with the 65 mm diameter single screw extruder, and it was set as the release layer.

(Production of film)

Lamination | stacking extrusion was performed in 245 degreeC three-layer T-die (feed block type, lip width 850mm, lip gap 1mm) as the base material layer, the adhesion layer, and the release layer were melted with each extruder. The extruded film was taken out at a casting roll having a temperature of 30 ° C. at a speed of 20 m / min, and solidified by cooling to give a substrate layer thickness of 28 μm, an adhesive layer thickness of 6 μm, a release layer thickness of 6 μm, a film width of 600 mm, and a film. Three, three-layer unstretched films having a length of 1100 m were obtained. Moreover, the unstretched film which has a film width of 550 mm and a film length of 500 m was obtained by slitting this film at 40N / 50m / min, applying a 50N contact pressure with respect to the film width with a rubber roll.

Example 2

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

60 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min), and an ethylene-alpha olefin copolymer ( 40 mass% of CX3007, 190 degreeC MFR: 3.7g / 10min, elasticity modulus: 26 MPa) was melt-extruded at 210 degreeC by the 45 mm diameter single screw extruder, and it was set as the adhesion layer.

Example 3

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

Styrene-type elastomer (hydrogenated body of block copolymer of styrene and butadiene, product made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) 40 mass% and ethylene-α olefin copolymer (Sumitomo Chemical Co., Ltd. make: VL100, 190 degreeC MFR: 0.8 g / 10 minutes, elasticity modulus: 64 MPa) 50 mass% and petroleum resin (Arakawa Chemicals: Alcon (registration) Trademark) 10 mass% of P125) was melt-extruded at 210 degreeC with the 40 mm diameter single screw extruder, and it was set as the adhesion layer.

Example 4

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

Styrene-based elastomer (manufactured by Asahi Kasei Chemicals: Taftech (registered trademark) H1041, styrene component ratio 30 mass%, ethylene component ratio 49 mass%, 230 ° C MFR: 5.0 g / 10 min) 85 mass% and ethylene-α olefin copolymer ( Made by Sumitomo Chemical Co., Ltd .: CX3007, 190 ° C MFR: 0.8 g / 10 min, elastic modulus: 26 MPa) 5 mass% and 10 mass% of petroleum resin (Arakawa Chemicals: Alcon (registered trademark) P125) are shortened by 40 mmφ. It melt-extruded at 210 degreeC with the extruder, and set it as the adhesion layer.

Example 5

In the state of Example 1, the base material layer and the release layer changed the adhesion layer to the following content, except the base material layer thickness was 26 micrometers, the adhesion layer thickness was 8 micrometers, and the release layer thickness was 6 micrometers. Three types and three layers of unstretched films were obtained by the manufacturing method similar to 1.

(Production of adhesive layer)

60 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min), and an ethylene-alpha olefin copolymer ( 40 mass% of CX3007, 190 degreeC MFR: 3.7g / 10min, elasticity modulus: 26 MPa) was melt-extruded at 210 degreeC by the 45 mm diameter single screw extruder, and it was set as the adhesion layer.

Example 6

In the state of Example 1, the base material layer and the release layer changed the adhesion layer to the following content, except the base layer thickness was 30 micrometers, the adhesion layer thickness was 4 micrometers, and the release layer thickness was 6 micrometers. Three types and three layers of unstretched films were obtained by the manufacturing method similar to 1.

(Production of adhesive layer)

40 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) and an ethylene-alpha olefin copolymer ( Made by Sumitomo Chemical Co., Ltd .: CX3007, 190 ° C. MFR: 3.7 g / 10 min, elastic modulus: 26 MPa) 55 mass% and 5 mass% of petroleum resin (Arakawa Chemicals: Alcon (registered trademark) P125) are shortened by 45 mmφ. It melt-extruded at 210 degreeC with the extruder, and set it as the adhesion layer.

Comparative Example 1

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

70 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) and an ethylene-alpha olefin copolymer ( Made by Sumitomo Chemical Co., Ltd .: CX3007, 190 ° C MFR: 3.7 g / 10 min, modulus of elasticity: 26 MPa) Shortened 20 mm and 20 mass% of petroleum resin (Arakawa Chemicals: Alcon (registered trademark) P125) by 40 mmφ. It melt-extruded at 210 degreeC with the extruder, and set it as the adhesion layer.

Comparative Example 2

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

70 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) and an ethylene-alpha olefin copolymer ( Made by Sumitomo Chemical Co., Ltd .: VL100, 190 ° C MFR: 0.8 g / 10 min, Modulus of elasticity: 64 MPa) Shortened 20 mm and 20 mass% of petroleum resin (Arakawa Chemicals: Alcon (registered trademark) P125) by 40 mmφ. It melt-extruded at 210 degreeC with the extruder, and set it as the adhesion layer.

Comparative Example 3

20 mass% of styrene-type elastomer (made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10min) and an ethylene-alpha olefin copolymer ( Made by Sumitomo Chemical Co., Ltd .: CX3007, 190 ° C MFR: 3.7 g / 10 min, modulus of elasticity: 26 MPa) Shortened 70 mm and 10 mass% of petroleum resin (Arakawa Chemicals: Alcon (registered trademark) P125) by 40 mmφ. It melt-extruded at 210 degreeC with the extruder, and set it as the adhesion layer.

[Comparative Example 4]

The base material layer and the release layer changed the adhesion layer to the following content in the state of Example 1, and obtained the unstretched film of three types and three layers by the manufacturing method similar to Example 1.

(Production of adhesive layer)

Styrene-type elastomer (product made by Asahi Kasei Chemicals: Taftec (registered trademark) H1221, styrene component ratio 12 mass%, ethylene component ratio 18 mass%, 230 degreeC MFR: 4.5 g / 10 minutes) 40 mass% and homo polypropylene (Sumitomo Chemical) A company made: 50 mass% of FLX80E4, 190 degreeC MFR: 7.5 g / 10min) and 10 mass% of petroleum resin (Arakawa Chemical Co., Ltd .: Alcon (trademark) P125) melt | dissolve at 210 degreeC with a 40 mm diameter single screw extruder. It extruded and it was set as the adhesion layer.

The results are shown in Tables 1 and 2.

As apparent from Table 2, the films obtained in Examples 1 to 6 had sufficient adhesive strength in practical use when used as protective films, and the peelability when the film was taken out of the roll was also good.

On the other hand, the film obtained by Comparative Examples 1 and 2 did not necessarily say that peelability at the time of taking out a film from a roll was favorable. The films obtained by Comparative Examples 3 and 4 did not have sufficient adhesive strength to the coating. Thus, all the films obtained by the comparative example were inferior in quality and were low in practical use.

Claims (5)

It is made by laminating an adhesive layer on one side of the base material layer containing polypropylene resin and a release layer on the opposite side by coextrusion,
The release layer is composed of only one or more selected from a polypropylene resin, low density polyethylene, an α-olefin polymer having 4 or more carbon atoms, and an α-olefin copolymer having 4 or more carbon atoms,
Resin which comprises the said adhesion layer contains a styrene-type elastomer and polyethylene-type resin at least,
The styrene-based elastomer is a hydrogenated product of a block copolymer having a styrene-based polymer block and a butadiene-based polymer block, or a hydrogenated product of a block copolymer having a styrene-based polymer block and a random copolymer block of styrene and butadiene, Polyethylene-based resins are ethylene homopolymers and / or ethylene-αolefin copolymers,
Content of the styrene-type elastomer in the said adhesion layer is 35 mass% or more and 99 mass% or less, and content of polyethylene-type resin is 1 mass% or more and 65 mass% or less,
The sum of the ethylene component and the polyethylene resin in the styrene-based elastomer is 35% by mass or more and less than 70% by mass in the adhesive layer component,
The ethylene component in the styrene-based elastomer is 15% by mass or more and 70% by mass or less,
The ethylene component in the said polyethylene-type resin is 70 mass% or more and 98 mass% or less, The self-adhesive surface protection film characterized by the above-mentioned. The self-adhesive surface protection film of Claim 1 whose bending elastic modulus of the polyethylene-type resin used for the said adhesion layer is 10 MPa or more and less than 90 MPa. The self-adhesive surface protection film of Claim 1 or 2 whose MFR (melt flow rate; 190 degreeC, 2.16 kgf) of polyethylene-type resin in the said adhesion layer is 0.5-8 g / 10min. The self-adhesive surface protection film of Claim 1 or 2 whose MFR (230 degreeC, 2.16 kgf) of the styrene-type elastomer in the said adhesion layer is 0.5-8 g / 10min. The self-adhesive surface protection film of Claim 1 or 2 whose MFR (230 degreeC, 2.16 kgf) of polypropylene resin in the said base material layer is 1.0-15 g / 10min.

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