TW200817180A - Surface-protective film - Google Patents

Abstract

A surface-protective film which has a specific substrate constitution and which, due to the mere employment of this constitution, can be formed into a roll, etc. in which even when the pressure-sensitive adhesive layer is adherent to the back side of the substrate, this pressure-sensitive adhesive layer can be easily peeled from the back side of the substrate. Thus, the roll can be unrolled with ease. The surface-protective film comprises a substrate and a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition comprising a rubbery resin ingredient as a major component. The substrate is either a substrate (a) which comprises, as a major component, an isotactic propylene homopolymer resin having a boiling-heptane insoluble content of 98.5% or higher and which has a tensile modulus of 700 Mpa or higher or a substrate (b) which is composed of a surface layer and an inner layer and has a tensile modulus of 550 Mpa or higher, the surface layer comprising, as a major component, an isotactic propylene homopolymer resin having a boiling-heptane insoluble content of 98.5% or higher and having a tensile modulus of 700 Mpa or higher and the inner layer comprising a polyolefin as a major component and having the pressure-sensitive adhesive layer superposed on one side thereof.

Description

200817180 IX. DESCRIPTION OF THE INVENTION: FIELD OF THE INVENTION The present invention relates to a surface protection film. More specifically, it relates to a surface that is used to prevent dust from adhering to a surface of a coated body or an injured surface. Protective film. I: Prior Art 3 Technical Background In the past, a surface protective film was used for the purpose of protecting articles and members. 10 The surface protective film is used for various types of coverings such as synthetic resin sheets, cosmetic sheets, coated steel sheets, copper sheets, and stainless steel sheets, etc., to prevent dirt from adhering to surfaces or surfaces during processing and transportation. And the user. This surface protective film has a structure in which an adhesive layer is laminated on the substrate. In general, the surface protective film is industrially manufactured, for example, by winding a long film 15 into a roll-like wound body. There is a strong demand for the surface protective film which is formed into such a roll-up body that the force (expansion force) required for unwinding the roll-up body is small, that is, the roll-up body can be easily unwound. On the other hand, in the surface protective film produced by the melt coextrusion method, in order to reduce the developing force, an adhesive layer is laminated on the substrate formed of the polyethylene 20 and the back surface of the substrate is formed. (The method of applying the rubbing treatment to the opposite surface of the adhesive layer on the side of the adhesive layer of the substrate, the same applies hereinafter) (Patent Document 1). However, the strength of the polyethylene is poor, and when the film is unwound, the base material of the surface protective film located inside the wound body is stretched by the adhesive of the outer protective film to be deformed, and there is a problem that it is not suitable for use depending on the case. 5 200817180 Therefore, on the substrate formed using polyethylene and polypropylene, a surface protective film having excellent strength and light spreading power has been proposed (Patent Document). [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. 7-62311. In addition, there are cases where a stronger adhesive type article is required. Since the effect of lowering the developing force is insufficient when only the above technique is used, it is further required to improve the developing force. SUMMARY OF THE INVENTION An object of the present invention is to provide a surface protective film which can be formed by a simple method which is generally called a specific substrate, for example, a rolled body, and the like, and an adhesive is wound on the back surface of the substrate. The layer is still 15 to easily peel the adhesive layer from the back surface of the substrate, and the surface protective film of the rolled body can be unwoundly unfolded. Means for Solving the Problem As a result of intensive research on a conventional surface protective film, the inventors of the present invention have found that a conventional surface protective film, particularly in the form of a rolled body, is stored and transferred, and the outer surface protective film is The adhesive tends to adhere strongly to the back surface of the substrate of the surface protective film of the inner layer, so that when the film is unfolded, the surface protective film of the outer layer is not easily peeled off from the surface protective film of the inner layer, and it is also found that When the adhesive force of the back surface of the substrate and the adhesive is strong, when the adhesive layer is peeled off from the back surface of the substrate, the back surface of the substrate is deformed by 6 200817180, and the cause of the large amount of energy consumption due to the deformation is caused. . On the other hand, a method of applying a release agent such as a long-chain fatty acid denatured product or a diarrhea gel to the back surface of the substrate to make the adhesive layer difficult to adhere to the back surface of the substrate, thereby reducing the developing force of the roll receptor has been used. The review has passed. However, in this method, it is necessary to carry out the troublesome work of coating, drying, and the like of the release agent. Further, in order to strengthen the fixing property of the back surface of the substrate and the release agent, it is necessary to surface-treat the back surface of the substrate. Therefore, there is a problem that the number of manufacturing processes of the so-called surface protective film increases and the manufacturing cost increases. On the other hand, it has been found that by using a specific component on the back side of the substrate, the substrate is set to a specific tensile modulus, and an adhesive composition having a main component of a rubber-based resin component is laminated. In the practice of the adhesive layer, the troublesome work such as application of a release agent is not required, and the surface protective film which is easily peeled off from the back surface of the substrate can be obtained, thereby completing the present invention. 15 20 That is, the surface protective film of the present invention is characterized in that it comprises an isotactic h〇m〇P〇lypropylene resin containing 98.5% or more of boiling insoluble matter. And a base material having a tensile modulus of 700 MPa or more and an adhesive layer formed by laminating the surface of the base material with an adhesive composition having a main component of a rubber gum component. Further, the surface-protective film of the present invention is characterized in that it comprises a surface-protecting film of a substrate and an i-layered Wei substrate. The substrate is composed of a surface layer and an inner layer, and has a stretching of 55_Pa or more. Elasticity, 7 200817180 The surface layer is based on the isotactic stereo ♦ propylene homopolymer resin with boiling heptane insoluble fraction of 98% or more, and has a tensile modulus of more than PCT. The inner layer is mainly composed of an olefin, and the adhesive layer is laminated on one of the five faces, and the adhesive layer is formed of an adhesive composition whose main component is a rubber-based resin component. The polypropylene homopolymer is preferably a meso-pentad fraction having a meso-pentad fraction of 90% or more. 10 The inner layer is preferably composed of a regrind containing a surface protective film. The non-layered layer of the agent layer is preferably a frictional release surface. The rubber enamel resin component is mainly composed of (1) a styrene polymer block and an olefin-based or conjugated diene-based polymer block. Block copolymer, (2) styrene polymer embedded a block copolymer of a random copolymer block of a styrene monomer and an olefinic or conjugated diene monomer, and/or (3) a styrene elastomer of the specific hydride thereof The effect of the invention is as follows. When the surface protective film of the present invention is used, a specific component is used on the substrate or the back side thereof, and the substrate is set to a specific tensile modulus and the rubber resin is laminated. The layer of the agent formed by the adhesive composition of the component as a main component can be easily peeled off from the back surface of the substrate without performing a troublesome work such as applying a release agent. The surface protective film of the invention for carrying out the invention of the best form of the invention is composed of 5 10 15 20 grease-based, Am-corrected, and special-purpose polypropylene homopolymer, which is mainly used as a base material for the knife and the dry Further, it may be a single layer or a layer structure composed of a surface layer and an inner layer. In the case of an early layer substrate and a multilayer structure, boiling heptane insoluble fraction on the back side accounts for 98.5 〇. /〇Structure the polypropylene uniform arm with the 4 gauge on the upper layer 3 Lipid is its main component. Here, the main ingredient ^ (4) comes from the tongue of the tongue, and the composition of the layer is the component of the layer of the eve. This kind of (four) kun homopolymer is under the full weight of the layer. Usually it is 50~1〇〇 weight|./^ 里里里/〇, preferably 55~9〇% by weight, preferably 60~80% by weight of the ratio #名丙浠Homopolymer resin and embedded total (4) Compared with no fresh (10) material, it is usually a stereoscopic regular car. The material with high stereo is high in the crystal domain and the same molecule, and has low affinity with other molecules, so it is not easy to withstand Therefore, it is possible to more easily expand the roll-up of the surface protective film of the back surface of the substrate by uniformly homogenizing the polypropylene having a high body size. The polypropylene homopolymer resin is preferably an isotactic polypropylene homopolymer. The isotactic polycondensation homopolymer has high stereoregularity and is easy to crystallize. Therefore, by using the isotactic polypropylene homopolymer, the surface protective film attached to the lunar surface of the substrate can be more easily peeled off, and the developing force of the rolled body can be further reduced. The stereoregularity index of the polypropylene homopolymer is usually the ratio of the boiling heptane insoluble fraction of the polypropylene 9 200817180 homopolymer which is not extracted by boiling heptane. The ratio of boiling heptane insolubles can also be used as an indicator of the content of the isotactic polypropylene homopolymer which is not extracted by boiling heptane. Boiling heptane does not 'the more the valleys, the more polypropylene with high stereoregularity. Therefore, the boiling heptane insoluble content of the propylene homopolymer resin is preferably 98.5% or more, and more preferably 99% or more. The expansion force of the wound body can be further reduced by using a polypropylene resin having a high proportion of boiling heptane insoluble. Fottenheptane insoluble fraction The sample resin and boiling n-heptane (for example, i〇f Lete grade) can be placed in a Soxhlet Extraction apparatus for extraction for 8 hours to determine the boiling η-heptane insoluble fraction. The weight is calculated according to the following formula. ^(W2/Wl)xl00 / 'w is the ratio of boiling η-heptane insoluble (% by weight), wi is the weight (g) of the sample ,月曰, and W2 is the weight of boiling η_heptane insoluble (g )). 15 In addition, the mes〇-five component ratio (mmmm) can be used as a selection index for isotactic polypropylene homopolymer (for example, see special opening 3-31451 to special opening 7-118322 and special opening) 2006-248156, etc.). The Meso-pentacomponent fraction is an isotactic chain of the crystalline polypropylene molecular chain tf?±L·, 士, U octet units measured by 13c-nmr, in other words, it is located at 2〇, The propylene single-single fraction of the center of the chain formed by the meso bond of the five propylene monomer units represents the stereoregularity of the polypropylene. Meso-five-bits are more and more south-dimensional. The meso-penta component rate is preferably 90%, more than 95%, and even more than 98%. The mes〇-five The cutting rate can be measured by, for example, the method described in, for example, JP-A No. 3_14851 or JP-A-2006-248156. Specifically, the methyl carbon can be calculated by the 3C-NMR spectrum 10 200817180. The area fraction of the mmmm peak in the total absorption peak of the field is determined. In the case of a single-layer substrate and a multilayer structure, the surface layer on the back side may contain other poly-polymers in addition to the above-mentioned polypropylene homopolymer. The olefin is not particularly limited, and examples thereof include polyacrylic acid, an olefin homopolymer which does not satisfy the above conditions, and a propylene-based polymerization of a block system or a random system formed of a propylene component and an ethylene component. a low-density, medium-density, high-density, linear low-twist polyethylene-based vinyl polymer; propylene-α-olefin copolymer, ethylene CX-unloaded copolymer, acetamidine·η_butyl acrylate vinegar ( Ethylene_n_butyl 〇acrylate), ^^, ethylene-ethylene acetate An olefin-based polymer such as an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, or an ethylene-methyl methacrylate copolymer. These polyolefins may be used singly or in combination of two or more kinds. Other polyolefins can be used, for example, at about the weight of the substrate, based on the total weight of the substrate, and more preferably 4% by weight or less. • In the case of a single-layer substrate and a multilayer structure, the surface layer on the back surface is particularly In the range satisfying the above-described tensile modulus, it is preferably formed of a polypropylene homopolymer # to a polyethylene resin. The polyethylene resin generally has a small tensile modulus and a polypropylene. The homopolymer is also difficult to bond for 20-inch drilling, and is effective for reducing the developing force by blending with the above-mentioned polypropylene homopolymer. In the case of a single-layer substrate and a multilayer structure The tensile modulus of the surface layer on the back surface is 7 〇〇 MPa or more, and more preferably it is above the capsule. Further, the multilayer structure composed of the surface layer and the inner layer has a tensile modulus of 51 for the substrate of 11 200817180. 〇MP A or more, preferably 6 〇〇 MPa or more. In this case, the long surface protective film is wound into a roll shape to form a roll-up body, and when the roll-up body is unfolded, the inside of the roll-up body is formed. The substrate of the surface protective film can be suppressed by the stretching agent of the outer surface protective film, and can be suppressed. Therefore, the deformation of the substrate can be reduced. (4) The surface of the outer layer is peeled off from the surface protective film of (4), and the rolled body can be unfolded effortlessly. _ 卩 ,, the material constituting the surface layer and the inner layer is used to increase the tensile modulus by using a crystal nucleating agent. It is better. Thereby, deformation of the substrate can be suppressed more. 1〇 The back side of the 1 material (non-returnable laminate layer) can also be rubbed. The rubbing treatment can be carried out by the method described in JP-A No. 2-252777 or the method according to the method. For example, a rubbing treatment of a cloth such as a rotating object or a gauze using a metal roller or the like can be exemplified. The inner layer of each structure contains polyanthracene as a main component. Such a poly(lene) 1 starts from a polypropylene homopolymer, and the above-exemplified polysmoke 12 1 and the like can be used. Among them, a polypropylene resin having a % by weight to 1% by weight and a proportion of 0% by weight of the polyethylene resin are used, and the tensile modulus is easily adjusted. Since the polypropylene homopolymer is easily broken in the unfolding direction, especially in the machine direction (MD), the "propylene homopolymer" is converted into a hydrocarbon, for example, low-density polyethylene (for example, low-density polyethylene) When a propylene-based resin such as LLDPE) or a block polypropylene is used to form the inner layer, mechanical strength can be ensured. The inner layer may be added with a surface protective film in a range that does not affect the physical properties. The recycled product may be a recycled product of a used surface protective film, or may be an edge chip in the production of a surface protective film. For example, the surface protection 200817180 η and the recycled product of the film are preferably about 20% or less, and more preferably about 20% or less, based on the total weight of the inner layer. This is because if the content of the recycled product is too large, it will contain a lot of polyolefin (4), which will not ensure the required tensile modulus. The use of recycled products can reduce production costs, or increase production efficiency. Further, the adhesion between the sacrificial layer and the substrate layer can be improved, and the mechanical strength such as tear resistance can be improved as described above. The pressure-sensitive adhesive layer is formed of an adhesive composition whose main component is a rubber-based resin component. In this way, in addition to the high-volume production process in which the substrate is melted and co-extruded together, a strong adhesion design can be performed at the same time. For example, the crucible can be temporarily adhered to the surface of the coated body having irregularities. Suitable for a wide range of surface protection films. The rubber-based resin component can be used as a base polymer which is used as an adhesive of a styrene-based elastomer, a urethane-based elastomer, an ester-based elastomer, or an olefin-based elastomer, without any particular limitation. material. 15 Specific examples thereof include styrene-butadiene-styrene (SBS), stupid ethylene-isoprene-styrene (SIS), and styrene-ethylene-butylene-styrene (SEBS)-ethylene. Abab-type block copolymers such as ethylene-propylene-succinium (seps); stupid ethylene-butadiene (SB), styrene-isoprene (SI), styrene-ethylene-butene ( SEB), a-B 20 type block copolymer such as styrene-ethylene-propylene (SEP); styrene-based random copolymer such as styrene-butadiene rubber (SBR), stupid ethylene-ethylene-butyl A-B-type styrene-olefin crystalline block copolymer such as olefin crystals (SEBC); olefin crystal block copolymerization of CBC type such as olefin crystalline ethylene-butene-olefin crystal (CEBC) 13; ethylene olefin, ethylene-propylene-α-olefin, propylene-α-olefin, etc. 13 200817180 Olefin-based elastomer, and the like, and the like. These rubber-based resin components may be used singly or in combination of two or more. The rubber-based resin component is preferably a styrene-based elastomer, and particularly preferably a styrene-based elastomer of the following (1), (2) or (3). (1) A styrene-based elastomer having a styrene-based polymer block (VIII) and a block copolymer of an olefin-based or conjugated diene-based polymer block (B) as a main skeleton. The styrene-based elastomer is not particularly limited as long as it has an A-B block copolymer as a main skeleton, and examples thereof include a copolymer represented by A-B, A-B-A, (A-B)n*(A-B)nX or the like. Further, η is an integer of 2 or more, and X is 10 residues derived from a dopant (the same applies hereinafter). (2) a block copolymer of a styrene-based polymer block (Α) and an olefin-based monomer and a random copolymer block (Β') of an olefin-based or conjugated diene-based monomer as a main skeleton A styrene elastomer. Here, the styrene monomer and the olefin monomer are not strictly monomers, and may contain oligomers or the like. 15 Examples of such a styrene-based elastomer include the following (2-1) to (2-4). (24) Block (Α) and block (Β') bond: Α-Β' block copolymer, (2_2) contains styrene and olefin or conjugated diene monomer Ethylene-increasing tapered block (C): A-B'-C block copolymerization 20, (2-3) containing styrene polymer block (A) to replace the above-mentioned gradient Block (C): A-B'-A block copolymer, (2-4) (2-1) ~ (2_3) repeat or its equivalent is bonded at any ratio: (A-B ')n or (A-B')nX, (A-B'-C)nX, (A-B'-A)nX and the like. 14 200817180 体(3) U The styrene bomb with the hydride of the above (1) or (7) as the main skeleton 5 10 15 20 Hunting the use of such a stupid vinyl elastomer, not only the production method of the dry cloth used in the past can be used. It is also possible to reduce the burden of the clothes environment by adopting a hybrid and co-extrusion method. Further, a surface protective film which is strong as described later is passed through. The degree of freedom of correction is also large. The range of use is also olefin-based compound block (8) and random. The terpene hydrocarbon to be used may, for example, be B. The dilute tobacco compound block (9) is preferably a polyisotopic term, a segment (8) and a random copolymer block (B). The above (7) alkene, money, and the like. The styrene-based elastomer of the main skeleton and (3) the hydride of the above-mentioned (2), the styrene-based monomer of the random copolymer block (B,) (A) In all the monomer compositions of the body, the person from the sinter styrene monomer component and the component from the random polymer block (B,) are in a weight ratio of 5 / A range of diene or olefinic monomers of J · 95 ~ μ · ^ 93~60 : 40. 40 is preferably in the range of 40, preferably 7: in the styrene-based elastomer of the above-mentioned (2), the i-body and (3) the styrene-based elastomer based on the hydride thereof. In the composition containing the tapered block (C), the content of the olefin and the composition of the block (C) are in the early form, the component of the styrene or olefin monomer in the block (A), and ethylene. The total amount of the content is from the range of 3:97 to 50:50 by weight of the conjugated diene of 15 200817180, preferably 5:95 to palpitations, more preferably 5:95 to 25:75. 5

The total amount of styrene monomer from Xin (4) and 肷 (B,) or 碍 (C) contains the specific material 4, and the (4) agent layer is called the collector force, and the surface is peeled off from the coating. When _, there will be a case where _ remains on the covering body; if too many '(four) agent layers _ force together, it becomes difficult to stick to the covering body. a 10 When the rubber rhyme component has an unsaturated double bond derived from a common organic olefin, 'because of the improvement from the _ sex and the resistance point (4), it is desirable that the unsaturated double bond is as small as possible, so the steamer is required to be hydrogenated. It is better. Under this ambiguity, the appropriate person is (4) a silk-filled end-wearing shirt. (4) A non-saturated bonded isobutylene is used as a rubber-based resin component. The hydride of the styrene elastomer of the above (1) and (2) is mainly composed of a hydride.

(3) In the styrene-based elastomer, a random copolymer block of a styrene monomer and a conjugated diene monomer in a total of a diene polymer block, or a gradient embedded 15 It is preferred that at least 80% of the double bonds of the conjugated diene moiety in the segment pass through the hydrogenation reaction and become saturated. The hydrogen addition ratio is preferably 9% or more, more preferably 100% or more. ^疋 In order to ensure heat resistance and finances. The weight average molecular weight of the styrene-based elastomer measured by GPC (Gel Permeation Chromatography) in terms of polystyrene is preferably in the range of 3 Torr to 204,000, preferably in the range of 50,000 to 200,000. If the weight average molecular weight is too small, the cohesive force of the adhesive layer is lowered, so that when the surface protective film is peeled off, the stickiness remains on the coated body. If the weight average molecular weight is too large, not only the adhesion is insufficient, but also when the surface protective film is produced, there is a problem that the solvent usage increases as the melt viscosity increases, and the viscosity of the solution increases. It is preferable that the rubber-based resin component of the rubber-based tree is 100% by weight, and the ratio of the rubber-based resin component is preferably 50%, and the adhesive group is 100% by weight.

10 15

20, under the purpose of force, etc.;::=- outside, making agent, softener, olefin resin, 矽 / 1 with you 1 such as 'dry polymer', liquid acrylic copolymer (four) polymerization It is a well-known additive such as a creamer, a hindered amine (4) e-mine, a chelating compound, an aging anti-filling agent (for example, oxidized dance, oxidized town, gas, external absorbent, etc.), a pigment, and the like. 'Shixi, zinc oxide, titanium oxide (four) Γ: = especially: _ with the formulation of the agent for the promotion _ Γ = agent agent can be, for example, aliphatic co-support, Fangxiang Shi 糸 copolymer, aliphatic. A petroleum-based resin such as an aromatic copolymer or a lipid-based fluorene copolymer, a coumarone-based resin, a rosin-based resin, a rosin-based resin such as a polymerized rosin, or an alkane A phenol-based resin, a xylene-based resin or the like, or the like, and a material which is usually used as a drying agent can be used without particular limitation. These drill-forming agents may be used singly or in combination of two or more. Further, a commercially available olefin resin may be used as a blending agent. When the agent composition contains a binding agent, the amount of the agent is not particularly limited, but on the other hand, in order to suppress the stickiness caused by the decrease in cohesive force, on the one hand, in order to moderately improve the adhesion, it is relative to Rubber system 17 200817180 The resin component is 100 parts by weight, the adhesion agent is preferably 8 parts by weight or less, more preferably 6 parts by weight or less, and still more preferably 50 parts by weight or less.

In addition, the addition of a softener to the additive is effective for improving the adhesion. The softening agent may, for example, be a low molecular weight diene polymer, a 5-polyisobutylene, a hydrogenated polyisoprene, a hydrogenated polybutadiene or the like. The above derivatives may, for example, be those having a fluorenyl group or a COOH group at one or both ends. Specifically, for example, hydrogenated butadiene diol, hydrogenated butadiene mono-ol, hydrogenated polyisoprene diol, 10 hydrogenated polyisoprene Alkene monool and the like. In order to appropriately increase the adhesive force of the pressure-sensitive adhesive layer, a hydrogenated product of a diene polymer such as hydrogenated polybutadiene or hydrogenated polyisoprene, an olefin softener or the like is preferably used. These softeners may be used singly or in combination of two or more. The number-average molecular weight of the softener is not particularly limited, but if the amount of the average molecular weight is too small, the substance from the layer of the coating agent to the covering may migrate, and it may become a cause of heavy release or the like. If the average molecular weight of the other side is too large, there is a lack of effect of improving the dryness. Therefore, the number average molecular weight of the softening agent is preferably in the range of 5 to 1,000,000, preferably in the range of 10,000 to 50,000. 20 Change the use of softening material, its special amount of silk (4), but if the dosage is too much 'exposure to high temperature and cake, from the coating _ away, the combination of the baby hair residue, so the secret agent, to It is preferable that it is preferably 8% or less, more preferably 20% by weight or less, and still more preferably 1% by weight or less. The thickness of the substrate and the adhesive layer constituting the surface protective film is appropriately adjusted according to the use of the surface 18 200817180 protective film, etc., but the thickness of the substrate is usually set to 10 to 80 μm, and the adhesive layer is provided. The thickness is usually set to about 4 to 3 〇 μπι. Further, the thickness of the surface layer and the inner layer constituting the multilayer substrate may be appropriately adjusted in consideration of tensile modulus and tearability. (5) The method for producing the surface protective film is not particularly limited, and, in addition to the general-purpose adhesive application method and the adhesive transfer method, for example, an adhesive composition constituting the adhesive may be used. The components of the substrate (the surface layer and the inner layer in the case of the multilayer structure) are melted and co-extruded, thereby forming a method in which the layers are integrated. In particular, the melt co-extrusion method using the T-die method is suitable because it can be easily manufactured at low cost. In this way, an adhesive composition containing a rubber-based resin component as a main component is formed on one surface of a substrate or a surface layer which is formed of a polypropylene homopolymer resin and has a tensile modulus of 7 Å to 10 MPa or more. In the method of forming the pressure-sensitive adhesive layer, even if the pressure-sensitive adhesive layer is adhered to the back surface of the substrate, the surface protection film to be drilled can be easily peeled off from the back surface of the substrate 15 . This is because, in addition to the release effect caused by the high crystallization effect from the molecular structure of the specific polypropylene homopolymer, the substrate becomes difficult to be deformed at the time of peeling, and the ruthenium consumed in the deformation of the substrate Can be reduced. Therefore, the rolled body wound in a roll shape can be unfolded without difficulty. An embodiment of the surface protective sheet of the present invention will be described in detail below. Furthermore, the present description is not limited to the contents disclosed in the following embodiments. The material constituting the surface layer and the inner layer of the substrate is prepared for the resin of the watch. 200817180 [Table 1]

In addition, in Table 1, MFR is measured according to JIS K7210. The degree of crystallization of the polypropylene resin is obtained by separating the diffraction pattern in the X-ray diffraction into a twin crystal 5 σ 卩 and an amorphous portion, and then obtaining the ratio according to the area ratio. The meso-penta component fraction was determined by measuring the c13_nmr spectrum. In addition, the boiling heptane insoluble fraction of the polypropylene resin is a soaking type extractor, and about 10 g of the sample is placed in a cylindrical filter paper, and then extracted with about 700 ml of boiling η-heptane for 8 hours. The ratio of the insoluble fraction was determined and determined. In addition, the Tensilon tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to measure at a tensile speed of 5 〇〇 mm/min and a jig pitch of 100 mm, 23 ° C and 50% RH according to JIS K7161. In the examples and comparative examples, the materials shown in Table 1 were prepared as the surface layer material and the inner layer material in the ratio shown in Table 2. In addition, SEBS (Kmton G1657, manufactured by Kraton Polymer Co., Ltd.) containing styrene-based elastomer 15 as a rubber-based resin component was prepared in an amount of 10 parts by weight, and Alcon P manufactured by Arakawa Chemical Co., Ltd. as a binding agent. - 125, 10 parts by weight of the drilling agent composition. The surface layer formed of the above resin composition, the inner layer, and the adhesive layer formed of the above-mentioned 20 200817180 adhesive composition are coextruded by a τ-type die method to form a layer in this order, and are obtained in a thickness of 5 μπι. On the substrate formed by the surface layer and the inner layer of the thick metal layer, a layer of (7) thick adhesive layer is laminated = a protective film. The surface protective film was taken up to a paper core having an inner diameter of 3 inches to obtain a wound body of a surface protective film. Further, the surface of the substrate is subjected to a rubbing treatment by a reverse twisting roller that wraps the gauze before being entangled in the paper core. Evaluation

15

(1) Tensile modulus When each of the surface protective films of the examples and the comparative examples was produced, the thickness of the 3〇μηι thick layer which was not provided was also prepared. Lai riding the field width 1 〇 _ length 150mm. The Tensilon tensile testing machine (manufactured by Toyo Seiki Co., Ltd.) was used to determine the tensile modulus of the substrate at a tensile speed of 500 mm/min, a jig spacing of coffee, C and 50% RH. . (2) Developing force 疋 The force required to rewind the winding body of each surface protective film of the examples and the comparative examples at a speed of 20 m /min, and the force of 0 〇 is calculated by the conversion value of 5 〇 plane width ( 3) Tear strength According to JIS K7128, the Eimend G_ test details the tear strength of each surface protective film of the examples and the comparative examples. The specific results are shown in Table 2. [Table 2] 21 200817180

Comparative Example VD <N Cn| ο 1—« ο you s rn Ό $ X 25.4 ϋΠ VO m »Ti Ο ο VO Ό 卜 ON inch<N rn X ι〇vd - inch CN jn Γ4 g ο 1— Μ <N <N \〇: <N VO ^Ti r4 X 31.0 5c to CvJ ο Ο I '.D oo inch P* X f-^ >4 ΓΛ \Τί Cs| Ο r-^ ο ! CM CN VO 2.57 X % 4 m jn <N o ο : m 1 ΓΛ oo <1 (7) Example 8 1 4 - 4 o • ί—i ο τ—1 , _, 1 153〇 | 0 rH 1 t 〇C\ ΓΛ g 〇8 1—4 ο inch v〇oo 〇〇m \D <N κη «TV \D m 2 S ό Ό: oo os v〇\ό d :〇24.0 inch JC to Γ4 Jn ιή O ο 00 00 卜心v〇Ό 0 1 iom ΡΊ mo r-4 ο 1^-1 m 1 5; 卜 s 〇o iH CN ITi Γό 〇or—^ ο 1 \ov〇<Ti w^ >〇;〇*r! 1 < .r—=«♦ jrj ”.〇o ο 1 OO 00 卜 s 〇ΓΛ Γ^ί "I-t Polypropylene homopolymer (1) Polypropylene homopolymerization (2) Polypropylene homopolymer P) Block polypropylene low density Polyethylene Polypropylene Homopolymer a) Polypropylene Homopolymer (2) Polypropylene Homopolymer (3) Block Polypropylene Random Polypropylene Low Density Polyethylene SEBS Adhesive Adhesive Agent with or without rubbing treatment surface layer Elasticity (MPa) Full elastic modulus (MPa) Deployment force (N/50mm) Deployment force judgment MD direction tearability (kg): c _ Evaluation result 22 200817180 [Simple description of the diagram] (None) [Main component symbol description 】 (none)

twenty three

Claims (1)

200817180 X. Patent application scope: 1. A surface protective film, characterized in that it comprises: an isotactic polypropylene homopolymer resin having a boiling heptane insoluble content of 98.5% or more as a main component, and having a mass of 700 MPa or more A substrate having an elastic modulus; and an adhesive layer formed by laminating an adhesive composition having a rubber-based resin component as a main component on one surface of the substrate. A surface protective film comprising a substrate and a surface protective film of an adhesive layer laminated on one surface of the substrate, characterized in that: the substrate is composed of a surface layer and an inner layer, and has a surface of 550 MPa. In the above tensile modulus, the surface layer is composed of an isotactic polypropylene homopolymer resin having a boiling heptane insoluble content of 98.5% or more, and has a tensile modulus of 700 MPa or more. The inner layer is mainly composed of a polyolefin, and the pressure-sensitive adhesive layer is laminated on one surface thereof, and the primer layer is formed of an adhesive composition whose main component is a rubber-based resin component. 3. The surface protective film according to item 1 or item 2 of the patent application, wherein the ratio of the meso-penta-component of the polypropylene homopolymer resin is above 9%. The surface protection film of claim 2, wherein the inner layer contains a regenerated product of a surface protective film. The surface protective film of claim 1 or 2, wherein the non-adhesive layer of the substrate is a frictional release surface. The invention relates to a surface protective film according to claim 1 or 2, wherein the rubber enamel resin component is embedded in (1) a styrene polymer block and an olefin-based or conjugated diene-based polymer. a block copolymer of the segment, (2) a block copolymer of a styrene polymer block and a random copolymer block of a styrene monomer and an olefin or a conjugated diene monomer, and/ Or (3) a styrene-based elastomer whose hydride is the main skeleton. 25 200817180 VII. Designation of representative representatives: (1) The representative representative of the case is: ( ). (none) (2) A brief description of the symbol of the representative figure: 8. If there is a chemical formula in this case, please reveal the chemical formula that best shows the characteristics of the invention: (none) 4