TW201443194A - Self-adhesive surface-protecting film - Google Patents

Abstract

A self-adhesive surface-protecting film characterized by being produced by laminating an adhesive layer on one surface of a base layer comprising a polypropylene resin and also laminating a release layer on the opposite surface of the base layer by co-extrusion, wherein the adhesive layer comprises a styrene elastomer (A) that is a hydrogenated product of a block copolymer of a styrene polymer block and a butadiene polymer block and has a styrene content of 5 to 40 wt% and a styrene elastomer (B) that is a hydrogenated product of a random copolymer of styrene and butadiene and has a styrene content of 40 to 70 wt%, the ratio of the weight of the styrene elastomer (A) to the total weight of the two styrene elastomers is 5 to 80 wt% inclusive, an adhesiveness-imparting resin is contained in an amount of 5 to 25 parts by weight relative to the sum total, i.e., 100 parts by weight, of the two styrene elastomers.

Description

Self-adhesive surface protection film

The present invention relates to an adhesive film. The adhesive film of the present invention can be suitably used for members such as ruthenium sheets for optical applications, synthetic resin sheets (for example, for building materials), stainless steel sheets (for building materials), aluminum sheets, plywood, steel sheets, glass sheets, home electric appliances, and precision. Mechanical and automotive body protection surfaces are used to protect objects from accumulation, storage, transportation, and manufacturing steps to avoid damage during handling, and to protect against damage during secondary processing (such as bending or pressurization).

The adhesive film used to protect the surface of the covering is used for the processing, storage and transportation of building materials, electrical, electronic products and automobiles. The adhesive film must have good adhesion and must be easily peeled off after use. The adhesive does not contaminate the surfaces.

In recent years, the aforementioned coverings have been diversified, and the coated surface is not only smooth but also has many irregularities on the surface. The covering having the uneven surface on the surface may, for example, be a 透镜-type lens portion for a cymbal of an optical member. In the case of a covering having irregularities on the surface of the cymbal, in order to exhibit sufficient adhesion, it is considered to improve the adhesion of the adhesive layer, etc., so that an adhesive force can be obtained even if the contact area is small.

In order to improve the adhesion of the adhesive layer, a styrene-based elastomer having high adhesion to a resin may be used as a main component, but When the adhesion of the adhesive layer is increased, when the film is stored in a roll shape and then the film is wound up, problems such as generation of agglomerates, elongation of the film portion, deformation, and the like occur. Furthermore, when the viscous mass is severe, there is also a problem that the volume of the film is large when the film is unwound, causing noise and significantly deteriorating the surrounding working environment.

Noise sometimes causes hearing loss and even sleep disorders obstacle. When the noise is 90 dB or more, according to the Japanese Ministry of Health, Labor and Welfare's publication of the Noise Prevention and Prevention Regulations, there will be restrictions on the work of the workers engaged in the operation to use the soundproof protective gear.

Adhesive film production by melt-extruding a full film of the film In the case of the above-mentioned measures, a fluorine-based resin, a ruthenium-oxygen resin (for example, see Patent Documents 1 and 2), or a saturated fatty acid dimethylamine (for example, see Patent Document 3), etc. In the case of roll storage, there is a possibility that the resin is transferred to the adhesive layer, and the adhesion reduction and contamination of the coating are not erased.

Further, it has been considered to use a styrene-based elastomer in the adhesive layer (for example, refer to Patent Documents 4, 5, and 6, etc.), but the above problems have not been satisfied for the adhesion of the crucible and the film being wound up after being wound in a roll shape. .

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-81589

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-308559

[Patent Document 3] Japanese Patent No. 4565058

[Patent Document 4] Japanese Patent Publication No. 08-73822

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2007-161882

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2007-332329

The object of the present invention is to provide a self-adhesive surface protective film which exhibits a strong adhesive force to a covering body and can be used for various covering bodies, and the film portion is not easily formed when the adhesive film is wound in a roll shape and then wound out of the film. Problems such as elongation and deformation are excellent in film processing suitability.

As a result of active investigation by the present inventors, the present inventors have found a method for solving the above problems.

In other words, the present invention is a self-adhesive surface protective film characterized in that an area-area adhesive layer of a base material layer composed of a polypropylene-based resin by co-extrusion, an anti-area layer release layer, and an adhesive layer containing a styrene content 5 to 40% by weight of styrene-based elastomer A, which is a block copolymer hydride of a styrene-based polymer block and a butadiene polymer block, and a benzene having a styrene content of 40 to 70% by weight. The vinyl elastomer B is a random copolymer hydrogenated product of styrene and butadiene; and the weight ratio of the styrene elastomer A is 5% by weight or more and 80% by weight based on the total of the two types of styrene elastomers. % or less; 5 to 25 parts by weight of the tackifying resin is blended with respect to 100 parts by weight of the total of the two types of styrene-based elastomers.

According to the present invention, a self-adhesive surface protective film can be obtained, and when the adhesive body exhibits a strong adhesive force, it can be used for various kinds of covering materials, and when the adhesive film is stored in a roll shape and rolled up, the film portion is less likely to be elongated. Problems such as deformation, and excellent film processing suitability.

At this time, the peeling force of the adhesive surface of the adhesive film to the release surface is preferably 200 cN/40 mm or less at 23 °C.

At this time, a film roll having a film width of 550 mm and a winding length of 1000 m is preferably less than 90 dB when the film is wound up at a speed of 20 m/min.

Further, at this time, the MFR (230 ° C, 2.16 Kgf) of the styrene-based elastomer A or the styrene-based elastomer B in the adhesive layer is preferably 0.5 to 8 g/10 min.

Further, at this time, the MFR (230 ° C, 2.16 Kgf) of the polypropylene resin in the base material layer is preferably 1.0 to 15 g/10 min.

Further, the resin used for the release layer at this time is preferably a non-oxygenated resin.

The adhesive film of the present invention has a strong adhesive force to the covering body and can be used for various coverings, and when the adhesive film is stored in a roll shape and then unwound the film, the film portion is less likely to be elongated and deformed, and the film processing is excellent. The advantages.

Figure 1 is a schematic diagram of the measured data.

Figure 2 is a schematic diagram of the measurement.

Figure 3 is a schematic diagram of the measurement.

[Formation of the Invention]

The present invention is a self-adhesive surface protective film characterized by A uni-layer adhesive layer of a base material layer composed of a polypropylene resin by co-extrusion, a reverse-area release layer, and an adhesive layer containing a styrene-based elastomer A having a styrene content of 5 to 40% by weight. a block copolymer hydride of a styrene polymer block and a butadiene polymer block, and a styrene elastomer B having a styrene content of 40 to 70% by weight, which is a styrene and butadiene a random copolymer hydride; the weight ratio of the styrene-based elastomer A to the total of the two types of styrene-based elastomers is 5% by weight or more and 80% by weight or less; and the total of the two types of styrene-based elastomers 100 parts by weight, 5 to 25 parts by weight of the adhesive resin.

Hereinafter, an embodiment of the adhesive film of the present invention will be described.

(adhesive layer)

When the resin constituting the adhesive layer of the present invention exhibits high adhesion and is wound up in a roll-shaped film, the film is less likely to cause partial elongation and deformation, and at least two types of styrene-based elastomer and tackifying resin are required. Further, in order to control the adhesion, an olefin-based resin such as a polyethylene resin, a tackifying resin, a softening agent, and polystyrene may be mixed as needed.

Among the two types of styrene-based elastomers to be used, one type of styrene-based polymer block and a block copolymer hydrogenated product of a butadiene polymer block (hereinafter referred to as a styrene-based elastomer A) may be mentioned. An AB type block polymer such as an ABA type block polymer such as styrene styrene-butadiene-styrene or a styrene-butadiene copolymer.

Among the two styrene elastomers used, the other is a random copolymer hydride of styrene and butadiene (hereinafter referred to as styrene elastomer B). A styrene-based random copolymer hydride such as styrene-butadiene rubber can be cited.

The melt flow rate (MFR: 230 ° C, 2.16 Kgf) of the styrene-based elastomer A or the styrene-based elastomer B used is preferably in the range of 0.5 to 8 g/10 minutes in terms of film formability. It should be in the range of 2.0 to 7.0 g/10 minutes.

The total amount of styrene elastomer in the adhesive layer, in order to play The high adhesion force and the roll-out property of the film are exhibited, and the weight ratio is preferably 60% by weight or more and 99% by weight or less based on the entire resin composition constituting the adhesive layer.

When the total amount of the styrene-based elastomer is less than 60% by weight, the adhesive force is lowered, and it is difficult to obtain a desired adhesive force. The total amount of the styrene elastomer in the adhesive layer is preferably in the range of from 65% by weight to 95% by weight.

In this case, a styrene-based elastomer other than the styrene-based elastomer A and the styrene-based elastomer B may be used as the styrene-based elastomer.

Also, the adhesive layer should contain both styrene elastomer A (benzene) a block copolymer hydride of a vinyl polymer block and a butadiene polymer block) and a styrene elastomer B (a random copolymer of styrene and butadiene), relative to the styrene system The total ratio of the elastomer A and the styrene elastomer B is preferably 5% by weight of the styrene elastomer A (hydrogenated copolymer of the styrene polymer block and the butadiene polymer block). the above.

When the weight ratio of the styrene-based elastomer A (the styrene-based polymer block to the block copolymer hydride of the butadiene polymer block) is less than 5% by weight, the adhesive force is lowered, and it is difficult to obtain the desired adhesive force. .

The weight ratio of the styrene-based elastomer A is more preferably 8% by weight or more, particularly preferably 20% by weight or more, based on the total amount of the styrene-based elastomer A and the styrene-based elastomer B.

On the other hand, compared to styrene elastomer A and styrene The total weight of the olefinic elastomer B is preferably 80% by weight or less based on the weight ratio of the styrene elastomer A (the styrene polymer block to the block copolymer hydride of the butadiene polymer block).

When the weight ratio of the styrene-based elastomer A is more than 80% by weight based on the total amount of the styrene-based elastomer A and the styrene-based elastomer B, the film may not be sufficiently exhibited in the form of a roll. .

The weight ratio of the styrene-based elastomer A is preferably 60% by weight or less, more preferably 50% by weight or less, particularly preferably 40% by weight or less.

Styrene elastomer A (styrene polymer block and butyl The weight ratio of the styrene component of the block copolymer hydrogenated product of the diene polymer block is preferably 5% by weight or more and 40% by weight or less.

When the weight ratio is less than 5% by weight, granulation is difficult in the production of the resin, and if the weight ratio is more than 40% by weight, it is adhered to the styrene-based elastomer B (a styrene-butadiene random copolymer hydride). The force is reduced and it is difficult to obtain the required adhesion.

Further, the styrene component weight ratio of the styrene elastomer A (the styrene polymer block and the block copolymer hydrogenated product of the butadiene polymer block) is preferably 5% by weight or more and 20% by weight or less. The range is preferably in the range of 5% by weight or more and 13% by weight or less, and the adhesion is more easily exhibited.

On the other hand, styrene elastomer B (styrene and dibutyl) The weight ratio of the styrene component in the olefinic random copolymer hydride) is preferably 40% by weight or more and 70% by weight or less.

When the weight ratio of the styrene component in the styrene-based elastomer B is less than 40% by weight, the styrene-based elastomer A (block copolymer hydride of the styrene-based polymer block and the butadiene polymer block) When the mixing is carried out, the film is not sufficiently exhibited in the form of a roll, and if it is more than 70% by weight, the adhesive force is lowered, and it is difficult to obtain the desired adhesive force.

Further, the styrene component of the styrene-based elastomer B (a hydrogenated product of a random copolymer of styrene and butadiene) is preferably in a range of from 45% by weight to 65% by weight.

The tackifying resin may, for example, be an aliphatic hydrocarbon resin or an aromatic hydrocarbon resin. , terpene resin, benzofuran ‧ resin, styrene resin and rosin resin. The molecular weight of the tackifying resin is not particularly limited and may be appropriately set. However, if the molecular weight is decreased, there is a concern that the adhesive layer moves or re-peeles into the adherend. On the other hand, if the molecular weight is increased, there is a follow-up. The tendency of the force enhancement effect is lacking, so the average molecular weight of the tackifying resin should be about 1000 to 100,000. The number average molecular weight can be measured by gel permeation chromatography or the like.

The content of the adhesive resin in the resin composition constituting the adhesive layer The total amount of the styrene-based elastomer A and the styrene-based elastomer B is in the range of 5% by weight to 25% by weight.

When the total amount of the tackifying resin is more than 25% by weight based on the total amount of the styrene-based elastomer A and the styrene-based elastomer B, the molecular weight of the tackifying resin is low, and the melt viscosity is extremely lowered, not only when a T-shaped mold or the like is used. When the film is formed by extrusion, it is difficult to laminate with the base material containing the polypropylene resin as a main component, and the adhesive layer will become sticky, and the roll-out property of the film from the rolled state is difficult to be improved. The tendency.

Further, if the total amount of the tackifying resin is less than 5% by weight based on the total amount of the styrene-based elastomer A and the styrene-based elastomer B, the adhesion of the adhesive layer does not change even if it is blended, and the desired adhesiveness cannot be obtained. force.

The content of the tackifying resin is preferably 6% by weight or more and 24% by weight or less, and more preferably 7% by weight or more and 23% by weight or less based on 100 parts by weight of the total of the two kinds of styrene-based elastomers.

When adding an adhesive resin to the adhesive layer, the melt viscosity is When the tendency is lowered, the polystyrene resin is added in an amount of about 1% by weight to about 15% by weight based on the total amount of the resin composition constituting the adhesive layer, thereby improving the difference in melt viscosity between the base material layer and the adhesive layer, thereby making it easy to laminate. . The polystyrene resin blending amount is preferably 5% by weight or more and 10% by weight or less.

Add a note about the softener.

Moreover, with respect to the entire resin composition constituting the adhesive layer, By adding a softener of about 0.1% by weight to 15% by weight, the adhesion to the covering having irregularities on the surface can be easily exhibited.

The softening agent may, for example, be a low molecular weight diene polymer, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene or such derivatives, and polybutene. The molecular weight of the softener is not particularly limited and may be appropriately set. However, if the molecular weight is decreased, there is a concern that the adhesive layer moves or re-peeles into the adherend. On the other hand, if the molecular weight is increased, there is a lack of adhesion. The tendency to enhance the effect, so the number average molecular weight of the softener is preferably about 1000 to 100,000. The number average molecular weight can be determined by the same method as in the case of the tackifying resin.

Moreover, the adhesive resin or softener used in the adhesive layer is The type is liquid or powder, and there are also substances that will contaminate the extruder when extruded. These problems can be improved by using a tackifying resin or a softening agent with a polyethylene resin or a polyolefin resin, and it is preferred to use a tackifying resin or a softening agent with a polyethylene resin or a polyolefin. The resin is used as a master batch.

The adhesive film of the present invention may contain a polyolefin resin in order to improve the roll-out property. The polyolefin-based resin is not particularly limited, and examples thereof include crystalline polypropylene, a copolymer of propylene and a small amount of an α-olefin, a low-density polyethylene, a high-density polyethylene, a copolymer of ethylene and a small amount of an α-olefin, and copolymerization of ethylene and vinyl acetate. Things and so on. Among them, the polyethylene-based resin is often used because it has a low modulus of elasticity and is easy to improve the unwinding property without lowering the adhesion.

The content of the polyolefin resin in the adhesive layer is preferably in the range of 1% by weight to 30% by weight based on the total amount of the resin composition constituting the pressure-sensitive adhesive layer.

When the content of the polyolefin resin is more than 30% by weight, the adhesive strength may be lowered depending on the resin to be used, and sufficient adhesion may not be obtained.

The content of the polyolefin-based resin in the adhesive layer is preferably mixed at a ratio of 25% by weight or less.

The adhesive film of the present invention may contain a conventional additive as needed. For example, it may contain a slip agent, an anti-blocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light stabilizer, and an impact modifier.

However, these components have a lower molecular weight and have a tendency to bleed out the surface of the adhesive layer and reduce the adhesion of the adhesive layer. Therefore, when an additive is used, the low molecular weight substance on the surface of the adhesive layer is preferably less than 1 mg/m ² .

Here, the measurement of the low molecular weight substance on the surface of the adhesive layer was carried out by the following procedure. After washing the surface of the adhesive layer with an organic solvent such as ethanol which does not erode the adhesive layer resin, the organic solvent is removed from the cleaning liquid by an evaporator or the like, and the residue is weighed, and the obtained value is divided by the surface area of the surface of the cleaned adhesive layer. Got it. Here, when the residue is present at 1 mg/m ² or more, it means that foreign matter is present between the surface of the adhesive layer and the surface of the adherend, thereby reducing the contact area and reducing the amount of van der Waals, thereby lowering the adhesive force. When adding an additive, it is necessary to select an additive such as a polymer type, and to check the addition amount and the addition method, etc., in order to avoid the movement and transfer of an adhesive layer.

The adhesive force of the adhesive film of the present invention is considered to be used in various For the covering, the acrylic sheet should preferably be in the range of 150 to 800 cN/25 mm at 23 °C. The acrylic sheet used for this evaluation was 88% or more containing a methacrylic resin. If the adhesive force is less than 150 cN/25 mm, the protective film may be lifted when the cover is protected, and the protective film function may not be achieved. On the other hand, if the adhesive force is more than 800 cN/25 mm, there is a concern that the film cannot be peeled off smoothly when the film is peeled off from the covering.

Further, it is preferable to use a range of 2 to 20 cN/25 mm for the bracts at 23 °C. If the adhesion is less than 2cN/25mm, the lifting will occur during protection, and the function of the protective film cannot be achieved. On the other hand, if the adhesive force is more than 20 cN/25 mm, there is a concern that the film cannot be peeled off smoothly when the film is peeled off. The adhesion can be suitably set by changing the resin composition or thickness of the adhesive layer.

The roll of the adhesive film of the present invention is taken into consideration, considering the working environment, A film roll having a film width of 550 mm and a winding length of 1000 m is preferably less than 90 dB when rolled out at a speed of 20 m/min. If the volume of the sound is greater than 90 dB, it is necessary to wear a soundproof protective gear. Preferably it is less than 88dB, more preferably less than 85dB. On the other hand, the volume should be as small as possible, but because the system has a pair of pressure The film of the adhesive layer strongly adhered to the force plate, in reality, about 70 dB is the lower limit of the roll-out sound.

(base material layer)

The adhesive film of the present invention requires a polypropylene-based resin as a base material layer as a main component, and examples of the polypropylene-based resin used herein include crystalline polypropylene, a random copolymer of propylene and a small amount of α-olefin, and a block copolymer. Specifically, the crystalline polypropylene resin may be an n-heptane insoluble homopolymer propylene homopolymer or a copolymer of propylene and other α-olefins containing 60% by weight or more of propylene, which is generally used for extrusion molding. The propylene or other α-olefin copolymer may be used singly or in combination.

The base material layer preferably contains 60% by weight or more of the propylene unit, more preferably 70% by weight or more. When the amount of propylene is less than 60% by weight, the film has no hardness and is difficult to use. Further, when the amount of propylene is less than 50% by weight or a polyethylene resin is used, the film is soft and easy to stretch, and problems such as elongation and deformation of the film portion are likely to occur when the film is wound up.

Here, the n-heptane insoluble property is an indicator of the crystallinity of the polypropylene, and at the same time, it indicates safety. The suitable aspect in the present invention is the use of n-heptane insoluble in the use of the Japanese Ministry of Health and Welfare No. 20 in February 1982 (25 ° C). In the case of extraction for 60 minutes, the eluted component is 150 ppm or less [30 ppm or less when the temperature exceeds 100 ° C).

Copolymerization of α-olefin in copolymer of propylene and other α-olefins The α-olefin having a carbon number of 2 to 8 is synthesized, and examples thereof include C4 or higher α-olefins such as ethylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1-pentene. Here, the copolymer is preferably a random or block copolymer obtained by polymerizing one or more of propylene and the above-exemplified α-olefin. Polypropylene resin used The melt flow rate (MFR: 230 ° C, 2.16 Kgf) is in the range of 1.0 to 15 g/10 min, preferably in the range of 2.0 to 10.0 g/10 min. Further, a copolymer of propylene and another α-olefin may be used in combination of two or more kinds.

Furthermore, the film obtained by the present invention can also be regranulated as a recycled raw material by the waste film produced during the processing of the product, and added to the substrate layer. By using recycled raw materials, production costs can be suppressed.

(release layer)

The adhesive film of the present invention forms a release layer on the reverse side of the adhesive layer of the substrate laminated layer, whereby even if the adhesive films overlap each other, there is little adhesion between the adhesive films, especially when the adhesive film is stored in a roll shape and then rolled out of the film. The film is less prone to problems such as partial elongation and deformation, and the film has excellent processing suitability. In order to make the adhesive films overlap each other, the adhesive between the adhesive films does not occur, and the surface irregularities are formed on the release layer, and the contact area with the adhesive layer is reduced.

It is effective to form the above-mentioned surface unevenness by mixing a non-compatible resin with a polypropylene resin. Thereby, a surface felt-like rough layer can be formed.

The non-compatible resin to be mixed at this time may, for example, be a polyethylene resin or a polymethylpentene resin. Further, by using a propylene-ethylene block copolymer as the polypropylene resin, the same effect can be expected without using a non-compatible resin.

At this time, the content of the ethylene component in the propylene-ethylene block copolymer is preferably from 3 to 18% by weight.

Further, of course, a non-compatible resin such as a polyethylene resin or a polymethylpentene resin may be further added to the propylene-ethylene block copolymer.

Polyolefin resin constituting the release layer, polyethylene resin and poly The total amount of the incompatible resin such as the methyl pentene resin is preferably from 3 to 40% by weight.

Non-compatible resin in polypropylene resin is suitable for low density An α-olefin (co)polymer having 4 or more carbon atoms such as polyethylene and a 4-methylpentene-1 (co)polymer. Other examples include linear low-density polyethylene, high-density polyethylene, copolymer of ethylene and a small amount of α-olefin, copolymer of ethylene and vinyl acetate, polystyrene, polyester resin, and polyamide resin. Wait. In particular, the 4-methylpentene-1 (co)polymer not only roughens the surface, but also improves the peeling property by lowering the surface free energy of the surface of the film.

Peeling of the adhesive surface of the adhesive film of the present invention with respect to the release surface The force is preferably in the range of 250 cN/40 mm or less at 23 ° C from the viewpoint of film roll-out property when the adhesive film is rolled. When the peeling force is more than 250 cN/40 mm, the film may be stretched and deformed when the film is rolled up as a roll. Further, the lower limit of the peeling force of the adhesive surface of the adhesive film with respect to the release surface is actually about 1 cN/40 mm, and is about 3 cN/40 mm.

In view of the resin composition of the adhesive layer of the present invention, the release layer table The three-dimensional average surface roughness SRa of the surface is preferably 0.10 μm or more and 0.50 μm or less. Thereby, the blocking resistance and the protective property of the covering can be improved. When the surface roughness of the release layer is less than 0.10 μm, the film may have a poor roll-out property when the film is in the form of a roll. If the surface roughness of the release layer is higher than 0.50 μm, the surface of the release layer is transferred to the surface of the adhesive layer, and the adhesion is remarkably lowered. At this time, the surface average roughness SRa of the surface unevenness of the release layer is preferably 0.25 μm or more and 0.45 μm or less.

Further, the ternary mean surface roughness SRa of the surface of the release layer indicates the average roughness of the center plane when the surface roughness curve is approximated by a sinusoid, and can be measured by a surface roughness measuring device or the like.

The thickness of the adhesive layer of the present invention is preferably 1 μm or more and less than 30 μm. When the thickness of the adhesive layer is less than 1 μm, it is difficult to customize the film by co-extrusion, and if it is 30 μm or more, it is disadvantageous to the cost.

At this time, when the adhesion is increased, the thickness is preferably increased in consideration of the viscosity. By increasing the thickness of the adhesive layer, it is easy to increase the contact area with the adherend. The thickness of the adhesive layer is preferably 2 μm or more and 20 μm or less, more preferably 3 μm or more and 15 μm or less, and particularly preferably 4 μm or more and 10 μm or less.

The thickness of the substrate layer of the present invention is preferably 5 μm or more and less than 100 μm, more preferably 10 μm or more and less than 75 μm, and more preferably 15 μm or more and less than 40 μm. When the thickness of the base material layer is less than 5 μm, the hardness is weakened, and when the protective film is attached to the covering body, wrinkles are likely to occur, and there is a problem that sufficient adhesion is not obtained, and if it is more than 100 μm, the cost is disadvantageous.

The thickness of the release layer of the present invention is preferably 1 μm or more and less than 30 μm. When the thickness of the adhesive film is less than 1 μm, it is difficult to form a custom film by co-extrusion, and if it is 30 μm or more, it is disadvantageous to the cost surface. The thickness of the release layer is preferably 2 μm or more and 20 μm or less, more preferably 3 μm or more and 15 μm or less.

Further, the self-adhesive surface protective film of the present invention preferably has a thickness of from 10 μm to 150 μm. It is preferably 15 μm or more and 120 μm or less, more preferably 20 μm or more and 100 μm or less. If the total film thickness is too thin, it will be difficult to use. If it is too thick, the rigidity is increased and it is difficult to use, and the cost surface is also unfavorable.

The self-adhesive surface protective film of the present invention is composed of the above-mentioned resin component The resin layer constituting each layer of the base layer, the adhesive layer, and the release layer can be fed to the feed module type or multi-manifold in a molten state by, for example, using a uniaxial or biaxial extruder. A T-shaped mold of the type is obtained by extrusion of three or more layers. In order to make each layer into a molten state, the molding temperature of each layer may be appropriately adjusted in consideration of the molding temperature of each layer, and may be adjusted, for example, in the range of 200 ° C to 260 ° C. The T-die temperature can also be the same as this temperature.

The adhesive film of the invention is suitable for taking rolls in use. Film roll The width and the upper limit of the length of the roll are not particularly limited, but in terms of ease of use, in general, the width is preferably 1600 mm or less, and the roll length is preferably 5000 m or less when the film thickness is 40 μm. Further, the take-up shaft can usually be a plastic shaft or a metal shaft of 3 inches, 6 inches, and 8 inches.

Moreover, from the viewpoint of processing suitability, it is preferable to roll a film roll having a length of 100 m or more and a width of 450 mm or more.

The adhesive film of the present invention can be used for components such as ruthenium for optical applications, synthetic resin sheets (for example, for building materials), stainless steel sheets (for building materials), aluminum sheets, plywood, steel sheets, glass sheets, home electric appliances, precision machinery, and the like. The car body protects the surface during manufacture to protect the stacking, storage, transportation, and manufacturing steps from damage during handling, and to protect against damage during secondary processing (such as bending or pressurization).

[Examples]

The invention will now be further illustrated by the examples. However, the present invention is not limited to the following examples without departing from the gist of the invention. In addition, the physical property evaluation methods of the following examples and comparative examples are as follows.

(1) Adhesion assessment

According to JIS-Z-0237 (2000) Adhesive Tape ‧ Adhesive Test Method, the measurement was carried out in the following manner.

Prepare acrylic sheet (Mitsubishi Rayon (AC): ACRYLITE 3mm thick) 50mm × 150mm and cymbal (the lens part is composed of a triangular prism, the height of the triangular column is 25μm, the width of the triangular column is 50μm) 50mm × 150mm as the adherend, the test piece The test piece was cut along the winding direction of the film by 150 mm and the vertical direction of 25 mm. The rubber roller of 2000 g was used. The surface of the roller was covered with a rubber layer of spring hardness of 80 Hs and a thickness of 6 mm. The width was 45 mm and the diameter (including rubber layer) was 95 mm. Then, the adherend and the test piece were pressed back and forth once at a speed of 5 mm/sec. After the pressure was applied, the mixture was allowed to stand at a temperature of 23 ° C and a relative humidity of 65% for 30 minutes, and the maximum resistance at 180 degree peeling at a speed of 300 mm/min was performed using "Autograph" (AGS-J) manufactured by Shimadzu Corporation. The value is used as the adhesion [cN/25mm]. The 180 degree peeling means that the peeling angle of the acrylic sheet and the film is maintained at 180 degrees when the peeling resistance value is measured.

At the time of measurement, a polyester sheet having a thickness of 190 μm and a size of 25 mm×170 mm was prepared as a grip end of the measurement sample, and the adhesive film and the acrylic sheet were pressed and then the edge of the adhesive film side in the sample was measured, and the adhesive end was adhered by a tape. Attached to a width of 15mm as the grip end for measurement. The mode diagram of the measurement sample is shown in Fig. 1. Three measurements were performed for one sample, and the average value was taken as the adhesion of the sample.

(2) MFR measurement of resin

The measurement was carried out in accordance with JIS-K7210.

(3) Determination of styrene component in styrene elastomer

Approximately 330 mg of the resin sample was dissolved in deuterated chloroform, and C-NMR (manufactured by BRUKER, AVANCE 500) was measured. Based on the obtained measurement results, the amount of the styrene component in the styrene elastomer was identified.

(4) Evaluation of peeling force

The acrylic sheet (Mitsubishi Rayon (ACYLITE 3mm thick)) 50mm × 150mm is fully attached with a double-sided adhesive tape (Nitto Electric Co., Ltd.: No. 535A), so that the other side of the double-sided adhesive tape is tested. The test piece was attached to a sheet of 150 mm (winding direction at the time of film production) × 50 mm (vertical direction in the winding direction at the time of film production).

As a new test piece, the test piece was cut out along the winding direction of the film at a winding direction of 150 mm and its vertical direction of 40 mm, and the adhesive surface was superposed on the release sheet of the test piece which was attached to the acrylic plate through the double-sided adhesive tape. Rubber roller with a mass of 2000g (the surface of the roller is covered by a rubber hardness of 80Hs, a rubber layer with a thickness of 6mm, a width of 45mm, and a diameter of 95mm including a rubber layer), and the release surface and the test piece are returned to the test piece at a speed of 5mm/sec. Pressurize then.

After pressing Next, its vertical 40mm of the total area ² is applied to the winding direction 100mm 4000mm 60Kg load, at a temperature of 40 ℃, relative humidity of 65% Environment After standing for 24 hours, cooled to 23 ℃, using Shimadzu (Unit ) "Autograph" (AGS-J), 180 degree peeling at a speed of 300 mm / minute. At the time of measurement, a polyester sheet having a thickness of 190 μm and a size of 40 mm × 170 mm was prepared as a grip end of the measurement sample, and attached to the edge of a 150 mm × 40 mm test piece by an adhesive tape with a tape width of 15 mm as a grip end at the time of measurement. In the measurement, the average resistance value when the test piece was pressed in a portion of 100 mm and peeled off from 40 mm to 60 mm was taken as the peeling force [cN/40 mm] of the test piece. The measurement was carried out 3 times, and the average value was taken as the final peeling force.

(5) The roll of the film roll

A film roll having a width of 550 mm and a roll length of 1000 m was measured and wound up at a speed of 20 m/min. The sound of the sound was measured using a noise meter (NL-20, manufactured by RION Co., Ltd.), and the microphone was placed directly under the film, and the La value was measured at a position 100 mm directly above the film roll and the film peeling point, and 50 mm from the edge portion of the film roll (A). characteristic). The measurement mode is shown in Figures 2 and 3. The measurement was carried out for 30 seconds, and the average value thereof was taken as the sound of the film roll.

[Example 1]

(Production of substrate layer)

The same polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd.: FLX80E4, 230 ° C MFR: 7.5 g/10 min) 100% by weight in 90 mm The single-shaft extruder was melt extruded at 240 ° C as a substrate layer.

(production of adhesive layer)

A block copolymer hydrogenated product of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 30 5% by weight of a random copolymer of styrene and butadiene (made by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min), 55% by weight, and petroleum resin (Arakawa Chemical Co., Ltd.: ARKON) P125) 15% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

(production of release layer)

90% by weight of a propylene-ethylene block copolymer (manufactured by Japan Polypropylene: BC3HF) and a low-density polyethylene resin (manufactured by Ube Industries: R300) 10% by weight at 65 mm The single screw extruder was melt extruded at 230 ° C as a release layer.

(production of film)

The base material layer, the adhesive layer and the release layer were each melted in each extruder, and laminated at 245 ° C in a three-layer T-die (feed module type, opening width 850 mm, opening gap 1 mm). . The extruded film was drawn at a speed of 20 m/min to a casting drum at a temperature of 30 ° C, and solidified by cooling to obtain 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 length of 1100 m. A 3-layer unstretched film. Further, the film was pulled at a slit speed of 50 m/min, and a tension of 40 N was applied. The rubber roller was subjected to a contact pressure of 50 N through the slit to obtain a film having a width of 550 mm and a film length of 1000 m.

[Embodiment 2]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydrogenated product of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 10 % by weight, a random copolymer of styrene and butadiene hydride (manufactured by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min), 80% by weight, and petroleum resin (Arakawa Chemical Co., Ltd.: ARKON) P125) 10% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Example 3]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydride of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 5 % by weight, a random copolymer of styrene and butadiene hydride (manufactured by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min) 80% by weight, petroleum resin (Arakawa Chemical Co., Ltd.: ARKON) P125) 10% by weight and ethylene-α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd.: CX3007, 190 ° C MFR: 3.7 g/10 min) 5% at 40 mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Example 4]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydride of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 20 5% by weight of a random copolymer of styrene and butadiene (made by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min), 50% by weight, petroleum resin (Arakawa Chemical Co., Ltd.: ARKON) P125) 10% by weight and ethylene-α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd.: CX3007, 190 ° C MFR: 3.7 g/10 min) 20% at 40 mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Comparative Example 1]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydrogenated product of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 30 % by weight, a random copolymer of styrene and butadiene (manufactured by JSR: DYNARON 1320P, styrene component ratio: 10% by weight, 230 ° C MFR: 3.5 g/10 min), 55% by weight, and petroleum resin (Arakawa Chemical Co., Ltd. :ARKON P125) 15% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Comparative Example 2]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydrogenated product of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 10 % by weight, styrene and butadiene random copolymer hydride (manufactured by JSR: DYNARON 1320P, styrene component ratio: 10% by weight, 230 ° C MFR: 3.5 g/10 min) 80% by weight and petroleum resin (Arakawa Chemical Co., Ltd. :ARKON P125) 10% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Comparative Example 3]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A random copolymer of styrene and butadiene (manufactured by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min), 90% by weight, and petroleum resin (ArkON Chemical Co., Ltd.: ARKON P125) 10% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

[Comparative Example 4]

The base material layer and the release layer were changed to the following contents in the same manner as in Example 1, and three kinds of three-layer unstretched films were obtained in the same manner as in Example 1.

(production of adhesive layer)

A block copolymer hydrogenated product of a styrene polymer block and a butadiene polymer block (manufactured by Asahi Kasei Chemicals: Tuftec H1221, styrene component ratio: 12% by weight, 230 ° C MFR: 4.5 g/10 minutes) 70 5% by weight of a random copolymer of styrene and butadiene (made by Asahi Kasei Chemicals: SOEL606, styrene component ratio: 46% by weight, MFR: 2.9 g/10 min) 20% by weight and petroleum resin (Arakawa Chemical Co., Ltd.: ARKON) P125) 10% by weight in 40mm The single-shaft extruder was melt extruded at 210 ° C as an adhesive layer.

The above results are shown in Tables 1 and 2.

As is apparent from Tables 1 and 2, when the film obtained in Examples 1 to 4 was used as a protective film, it had a practical adhesive force, and the film was excellent in roll-out property when rolled up in a roll shape.

On the other hand, when the film obtained in Comparative Example 1, Comparative Example 2, and Comparative Example 4 was wound up in a roll shape, the volume was large, and the roll-out property was not good. The adhesion of the film obtained in Comparative Example 3 to the covering body was not sufficient. As described above, the films obtained in the comparative examples were all inferior in quality and low in practicality.

Claims (6)

A self-adhesive surface protective film characterized in that an area-area adhesive layer of a base material layer composed of a polypropylene-based resin by co-extrusion, an anti-area layer release layer, and an adhesive layer containing a styrene content of 5 to 40% by weight a styrene-based elastomer A which is a block copolymer hydride of a styrene-based polymer block and a butadiene polymer block, and a styrene-based elastomer B having a styrene content of 40 to 70% by weight. a styrene-butadiene random copolymer hydrogenated product; the weight ratio of the styrene-based elastomer A to the total of the two styrene-based elastomers is 5% by weight or more and 80% by weight or less, relative to 100 parts by weight of the total of the two types of styrene-based elastomers, and 5 to 25 parts by weight of the tackifying resin. The self-adhesive surface protective film of claim 1, wherein the adhesive force of the adhesive surface of the adhesive film with respect to the release surface is 250 cN/40 mm or less at 23 ° C. The self-adhesive surface protective film according to claim 1, wherein the film roll having a film width of 550 mm and a winding length of 1000 m is wound at a speed of 20 m/min and has a roll sound of less than 90 dB. The self-adhesive polypropylene film according to any one of claims 1 to 3, wherein the MFR (230 ° C, 2.16 Kgf) of the styrene elastomer A or the styrene elastomer B in the adhesive layer is 0.5 to 8 g / 10 minutes. The self-adhesive polypropylene film according to any one of claims 1 to 4, wherein the polypropylene resin in the base material layer has an MFR (230 ° C, 2.16 Kgf) of 1.0 to 15 g/10 min. The self-adhesive polypropylene film according to any one of claims 1 to 5, wherein the resin used for the release layer is a non-oxygenated resin.