CN103254815A

CN103254815A - Surface protection sheet

Info

Publication number: CN103254815A
Application number: CN2012100361636A
Authority: CN
Inventors: 武田公平; 生岛伸祐; 山户二郎
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2012-02-15
Filing date: 2012-02-15
Publication date: 2013-08-21
Also published as: WO2013121846A1

Abstract

本发明提供一种表面保护片，是在基材层的一面形成有粘合层的表面保护片，其与各种被粘附体的粘合力良好，抗撕裂性优异，耐气候性非常优异，即使在室外使用或在高温下保存的情况下，其粘合力的增加也很少，从被粘附体上剥离时的剥离性良好。本发明的表面保护片是在基材层的一面形成有粘合层的表面保护片，该基材层是利用JIS-K-7127测定出的初期弹性模量为5000kg/cm²以上的聚烯烃系树脂层，该基材层至少包含白色系层及黑色系层2层，该粘合层是利用JIS-K-7127测定出的初期弹性模量为1～50kg/cm²的苯乙烯系树脂层，该表面保护片的爱尔门道夫撕裂强度为50g以上。The present invention provides a surface protection sheet having an adhesive layer formed on one side of a substrate layer, which has good adhesion to various adherends, excellent tear resistance, and excellent weather resistance. Excellent, even when used outdoors or stored at a high temperature, the increase in the adhesive force is small, and the peelability when peeled from the adherend is good. The surface protection sheet of the present invention is a surface protection sheet in which an adhesive layer is formed on one side of a base layer, and the base layer is a polyolefin having an initial elastic modulus of 5000 kg/cm2 or ^more as measured by JIS-K-7127. A resin layer, the substrate layer includes at least two layers of a white color layer and a black color layer, and the adhesive layer is a styrene-based resin with an initial elastic modulus of 1 to 50 kg/ ^cm2 measured by JIS-K-7127 Layer, the Elmendorf tear strength of the surface protection sheet is more than 50g.

Description

Surface protective plate

Technical field

The present invention relates to a kind of surface protective plate.Specifically; the present invention relates to the surface protective plate that can in following purposes etc., use; namely; for example to metal sheet, application member such as metal sheet, aluminum alloy frame, resin board, decorative steel plate, vinylchlorid laminate steel, sheet glass carry, when processing or maintenance etc., be attached to these component surface and protected.

Background technology

As necessary characteristic for surface protective plate, can enumerate following characteristic, that is, and on being attached at by adherend after, do not have floating or peeling off of this surface protective plate, peeling off on bonding coat can not remain in by adherend when removing.Particularly; during before surface protective plate is peeled off at high temperature or carry out under the inferior harsh condition of outdoor exposure when being attached the operation of this surface protective plate by adherend; in necessary above-mentioned characteristic concerning surface protective plate, then require the characteristic of higher level.In addition, need to suppress to be attached to the situation of splitting when being peeled off by the surface protective plate on the adherend.

In the past, in the bonding coat of the surface protective plate that generally uses, use in natural rubber or modified natural rubber, cooperate an amount of tackifier etc. and natural rubber be tackiness agent.This kind surface protective plate does not have special problem with regard to indoor use.But, because natural rubber is that tackiness agent has unsaturated double-bond in its structure, therefore be exposed under the outdoor situation, can cause molecular breakdown because of ultraviolet ray.Thus, be the surface protective plate of tackiness agent when peeling off having used natural rubber, can produce adhesive residue in by the problem in the adherend.Thus, wish to have weathering resistance surface of good screening glass.In addition, also have and to be attached at splintery problem when being peeled off by the surface protective plate on the adherend.

In order to address the above problem, the synthetic rubber such as acrylic adhesive, polyisobutene that proposed when the formation of bonding coat acrylic copolymer is improved not lose fusible degree cross-linked three Dization with isocyanate compound or methylol compound cohesive force is tackiness agent.But, because these tackiness agents are solvent systems, therefore in the safety and sanitation of surface protective plate, aspect existing problems such as the viewpoint of public hazards, economy.

In recent years, in order to improve these problems, require to realize the solvent free of tackiness agent.As its strong approach, the substrate layer of studying the bonding coat that will comprise thermoplastic elastomer and comprising polyolefin-based resins utilizes coextrusion film processed and makes the method (for example with reference to patent documentation 1, patent documentation 2) of surface protective plate.

But, in these surface protective plates, also exist and will be attached at when being peeled off by the surface protective plate on the adherend problem of splintery problem still and weathering resistance deficiency.

The prior art document

Patent documentation

Patent documentation 1 Japanese kokai publication hei 5-194923 communique (page 2)

Patent documentation 2 Japanese kokai publication sho 61-103975 communiques (page 1)

Summary of the invention

The objective of the invention is to; a kind of surface protective plate is provided; it is the surface protective plate that is formed with bonding coat in the one side of substrate layer; itself and various bounding force by adherend are good; tear strength excellence, weathering resistance are very excellent, even under the situation of outdoor application or preservation at high temperature; the increase of its bounding force also seldom, the separability when being peeled off by adherend is good.

Surface protective plate of the present invention is the surface protective plate that is formed with bonding coat in the one side of substrate layer,

This substrate layer is that the initial stage Young's modulus that utilizes JIS-K-7127 to determine is 5000kg/cm ²Above polyolefin-based resins layer,

This substrate layer comprises the white color system layer at least and black is 2 layers on layer,

This bonding coat is that the initial stage Young's modulus that utilizes JIS-K-7127 to determine is 1～50kg/cm ²The phenylethylene resin series layer,

The love Er Mendaofu tear strength of this surface protective plate is more than the 50g.

According to the present invention; a kind of surface protective plate can be provided; it is the surface protective plate that is formed with bonding coat in the one side of substrate layer; itself and various bounding force by adherend are good; tear strength excellence, weathering resistance are very excellent, even under the situation of outdoor application or preservation at high temperature; the increase of its bounding force also seldom, the separability when being peeled off by adherend is good.

Embodiment

Surface protective plate of the present invention is formed with bonding coat in the one side of substrate layer.

Substrate layer is that the initial stage Young's modulus that utilizes JIS-K-7127 to determine is 5000kg/cm ²Above polyolefin-based resins layer.At the above-mentioned initial stage Young's modulus of substrate layer less than 5000kg/cm ²Situation under, the toughness of surface protective plate just might reduce, for example hand paste operability might variation.Initial stage Young's modulus as substrate layer is preferably 6000kg/cm ²～20000kg/cm ², 6500kg/cm more preferably ²～15000kg/cm ²

Substrate layer contains polyolefin-based resins.Polyolefin-based resins in the substrate layer contain proportional being preferably more than the 60 weight %, more preferably more than the 70 weight %, more preferably more than the 80 weight %, be preferably especially more than the 85 weight %, most preferably be more than the 90 weight %.This kind polyolefin-based resins both can only use a kind, also can use more than 2 kinds.

As polyolefin-based resins contained in the substrate layer, can adopt appropriate arbitrarily polyolefin-based resins, yet from becoming viewpoints such as membrane stability, burning to consider acrylic polymers such as optimization polypropylene; Low Density Polyethylene (LDPE), linear low density polyethylene ethylene-based polymers such as (LLDPE).

The density of the ethylene-based polymer that can contain in the substrate layer is preferably 0.88～0.93g/cm ³, 0.895～0.920g/cm more preferably ³

Substrate layer preferably comprises 2 layers on white color system layer and black system layer at least.Like this, just can form the very outstanding surface protective plate of weathering resistance.

The white color system layer is the layer that demonstrates the tone of white color system, and for example the whiteness by the JIS-L-1015 regulation is preferably more than 60%, more preferably more than 70%, more preferably more than 80%, is preferably more than 85% especially.The white color system layer preferably comprises white pigment.As white pigment, can adopt appropriate arbitrarily white pigment.As this kind white pigment, for example can enumerate titanium oxide.Contain at the white color system layer under the situation of white pigment, it contains proportional resinous principle with respect to formation white color system layer and is preferably 0.1～50 weight %, more preferably 1～30 weight %, more preferably 5～20 weight %.

The resinous principle that forms the white color system layer is preferably polyolefin-based resins, more preferably is selected from least a kind in acrylic polymer and the ethylene-based polymer, more preferably density 0.88～0.93g/cm ³Ethylene-based polymer.As the resinous principle that forms the white color system layer, specifically, can preferably enumerate polypropylene, Low Density Polyethylene (LDPE), linear low density polyethylene (LLDPE).Polyolefin-based resins in the white color system layer contain proportional being preferably more than the 60 weight %, more preferably more than the 70 weight %, more preferably more than the 80 weight %, be preferably especially more than the 85 weight %, most preferably be more than the 90 weight %.This kind polyolefin-based resins both can only use a kind, also can use more than 2 kinds.

The thickness of white color system layer can adopt appropriate arbitrarily thickness according to purpose.This kind thickness is preferably 1～50 μ m, 3～40 μ m more preferably, and more preferably 5～30 μ m are preferably 10～30 μ m especially.

Black system layer is the layer that demonstrates the tone of black system.Black system layer preferably comprises black pigment.As black pigment, can adopt appropriate arbitrarily black pigment.As this kind black pigment, for example can enumerate carbon black.Layer contains under the situation of black pigment in black system, and it contains proportional resinous principle with respect to formation black system layer and is preferably 0.01～10 weight %, more preferably 0.1～5 weight %, more preferably 0.5～3 weight %.

The resinous principle that forms black system layer is preferably polyolefin-based resins, more preferably is selected from least a kind in acrylic polymer and the ethylene-based polymer, more preferably density 0.88～0.93g/cm ³Ethylene-based polymer.As the resinous principle that forms black system layer, specifically, can preferably enumerate polypropylene, Low Density Polyethylene (LDPE), linear low density polyethylene (LLDPE).Polyolefin-based resins in the black system layer contain proportional being preferably more than the 60 weight %, more preferably more than the 70 weight %, more preferably more than the 80 weight %, be preferably especially more than the 85 weight %, most preferably be more than the 90 weight %.This kind polyolefin-based resins both can only use a kind, also can use more than 2 kinds.

The thickness of black system layer can adopt appropriate arbitrarily thickness according to purpose.This kind thickness is preferably 1～100 μ m, 5～70 μ m more preferably, and more preferably 10～60 μ m are preferably 20～50 μ m especially.

In substrate layer, for preventing purposes such as deterioration, also can contain appropriate arbitrarily additive.As this kind additive, for example can enumerate oxidation inhibitor; UV light absorber; Hindered amine is photostabilizers such as photostabilizer; The anti-electrostatic agent interfering; Weighting agents such as calcium oxide, magnesium oxide, silicon-dioxide, zinc oxide, titanium oxide; Pigment; Preventing materials accumulation agent (order ヤニ prevents drug); Lubricant; Anti; Whipping agent; Polymine etc.

The thickness of substrate layer can adopt appropriate arbitrarily thickness according to purpose.As this kind thickness, be preferably 20～300 μ m, more preferably 30～250 μ m, more preferably 40～200 μ m.

In the rear side of substrate layer, for giving anti-skid or the easy purpose of cutting property (handycut), also can implement concavo-convex processing.In addition, also can form various functional layers such as printed layers in the rear side of substrate layer.

Bonding coat is that the initial stage Young's modulus that utilizes JIS-K-7127 to determine is 1～50kg/cm ²The phenylethylene resin series layer.At the above-mentioned initial stage Young's modulus of bonding coat less than 1kg/cm ²Situation under, might can't embody enough tear strengths.Above-mentioned initial stage Young's modulus at bonding coat surpasses 50kg/cm ²Situation under, it is really up to the mark that bonding coat might become.Initial stage Young's modulus as bonding coat is preferably 3kg/cm ²～40kg/cm ², 4kg/cm more preferably ²～30kg/cm ²And among the present invention, the initial stage Young's modulus of bonding coat is to coat on the barrier film formation material (binder composition) that forms bonding coat and drying, and making is only measured for the test film of binder layer.

Bonding coat contains phenylethylene resin series.Phenylethylene resin series in the bonding coat contain proportional being preferably more than the 50 weight %, more preferably more than the 60 weight %, more preferably more than the 70 weight %, be preferably especially more than the 80 weight %, most preferably be more than the 90 weight %.This kind phenylethylene resin series both can only use a kind, also can use more than 2 kinds.

As phenylethylene resin series contained in the bonding coat, can adopt appropriate arbitrarily phenylethylene resin series.Among the present invention, as phenylethylene resin series, be preferably the hydrogenation thing of the mixture of A/B/A or A/B/A and A '/B '.Here, A and A ' are the polymeric blocks that is made of styrenic monomers, and B and B ' are the polymeric blocks that is made of conjugated diolefine.

The molecular weight of the polymeric blocks that is made of styrenic monomers is preferably 1000～1000000, and more preferably 2000～100000.The second-order transition temperature of the polymeric blocks that is made of styrenic monomers is preferably more than 20 ℃.

The molecular weight of the polymeric blocks that is made of conjugated diolefine is preferably 1000～1000000, and more preferably 10000～300000.The second-order transition temperature of the polymeric blocks that is made of conjugated diolefine is preferably below-20 ℃.

As styrenic monomers, can adopt the appropriate monomer arbitrarily with vinylbenzene structure.As this kind styrenic monomers, for example can enumerate vinylstyrene, vinyl-dimethyl benzene, ethyl styrene, isopropyl benzene ethene, alpha-methyl styrene etc.Styrenic monomers can only be a kind both, also can be more than 2 kinds.

As conjugated diolefine, can adopt the appropriate monomer arbitrarily with conjugated diolefine structure.As this kind conjugated diolefine, for example can enumerate divinyl, isoprene etc.Conjugated diolefine can only be a kind both, also can be more than 2 kinds.

The hydrogenation of phenylethylene resin series is preferably the optionally state of hydrogenation of the polymeric blocks that will be made of conjugated diolefine.The degree of the hydrogenation of the polymeric blocks that is made of conjugated diolefine of phenylethylene resin series generally is preferably more than the 60 weight % with respect to the conjugated diolefine composition, more preferably more than the 80 weight %.Generally under the situation less than 60 weight %, enough tear strengths might can't be embodied with respect to the conjugated diolefine composition in the degree of the hydrogenation of the polymeric blocks that is constituted by conjugated diolefine of phenylethylene resin series.

In the phenylethylene resin series of the present invention, the ratio of A and B is preferably A: B=5: 95～50: the ratio of 50, A ' and B ' is preferably A ': B '=5: 95～50: 50.

In bonding coat, for purposes such as adjusting binding propertys, also can in the scope of not damaging purpose of the present invention, mix other phenylethylene resin series.

When forming bonding coat, for purposes such as control adhesion characteristics, can be as required, for example suitably adding tenderizer, ethylene series resin, silicone-based polymkeric substance, aqueous acrylic copolymer, tackifier, protective agent, hindered amine is photostabilizer, UV light absorber, polymine, fatty acid amide, phosphoric acid ester, weighting agent or pigment additives such as (for example calcium oxide, magnesium oxide, silicon-dioxide, zinc oxide, titanium oxide etc.).

Also can be as required to bonding coat surface embodiment such as Corona discharge Treatment, uviolizing processing, flame treating, Cement Composite Treated by Plasma, sputter etching processing etc. with to fusible control or to attach operability etc. be the surface treatment of purpose.

The cooperation of tackifier is effective for improving bounding force.But, the generation of the glue trace problem that causes for fear of the reduction by cohesive force, with the use level that is suitably determined tackifier by adherend accordingly of application surface screening glass.For the use level of tackifier, as a rule, with respect to phenylethylene resin series, be preferably below the 60 weight %, more preferably below the 50 weight %, more preferably below the 40 weight %, be preferably especially below the 30 weight %.

As tackifier, for example can use petroleum line resin, coumarone-indenes such as aliphatics based copolymer, aromatic series based copolymer, aliphatics aromatic series based copolymer system or ester ring type based copolymer is that resin, terpenic series resin, terpenes phenolic aldehyde are that rosin series resins such as resin, polymerized rosin, (alkyl) phenolic aldehyde are the material that resin, diformazan benzene series resin, their hydride etc. generally use in tackiness agent with being not particularly limited.Tackifier both can only use a kind, also can use more than 2 kinds.In the middle of these tackifier, consider the tackifier that preferred hydrogenation is from aspects such as separability or weathering resistances.And, the material that tackifier also can use conduct and the mixture of olefin resin to sell in market.

The cooperation of tenderizer is effective for improving bounding force.As tenderizer, for example can enumerate low-molecular-weight diene polymer, polyisobutene, hydrogenated polyisoprene, hydrogenated butadiene polymer, their derivative etc.As this kind derivative, for example can example be illustrated in the material that an end or two ends have OH base or COOH base, specifically, can enumerate hydrogenated butadiene polymer glycol, hydrogenated butadiene polymer single methanol, hydrogenated polyisoprene glycol, hydrogenated polyisoprene single methanol etc.Particularly, from suppressing considered the hydride of diene polymers such as preferred hydrogenated butadiene polymer or hydrogenated polyisoprene or ethylene series tenderizer etc. by the purpose of the fusible raising of adherend.As this kind tenderizer, specifically, can buy the trade(brand)name " Kuraprene LIR-200 " of (strain) Kuraray system etc.These tenderizers both can only use a kind, also can use more than 2 kinds.

The molecular weight of tenderizer can suitably be set at appropriate arbitrarily amount, if yet molecular weight diminishes, then might cause from bonding coat to by the substance transfer of adherend or heavy peeling off etc., on the other hand, if the molecule quantitative change is big, then have the trend of the raising effect that lacks bounding force, so the number-average molecular weight of tenderizer is preferably 5000～100,000, more preferably 10,000～50,000.

When using tenderizer, its addition can suitably be set at appropriate arbitrarily amount, if yet addition is many, the trend that glue trace when then having high temperature or outdoor exposure increases, therefore with respect to phenylethylene resin series, be preferably below the 60 weight %, more preferably below the 50 weight %, more preferably below the 40 weight %, be preferably especially below the 30 weight %.

The thickness of bonding coat is as long as suitably be set at appropriate arbitrarily thickness according to desired bounding force etc.The thickness of bonding coat is preferably 1～50 μ m, more preferably 2～40 μ m, more preferably 5～20 μ m.

Phenylethylene resin series before the hydrogenation can utilize arbitrarily appropriate methods to make.As this kind manufacture method, for example in unreactive hydrocarbons solvent (for example hexanaphthene etc.), use s-butyl lithium etc. is carried out the living polymerization of styrenic monomers, add conjugated diolefine then, two block structures of the polymeric blocks of the polymeric blocks that formation is made of styrenic monomers/constituted by conjugated diolefine, if desired, then form three block structures to wherein adding styrenic monomers again.In addition, also can form three block structures, branched block structure etc. by using the above coupling agent of 2 officials energy.

Method as to the hydrogenation of phenylethylene resin series can adopt appropriate methods arbitrarily.As this kind method, for example can enumerate following method etc., namely, dissolving phenylethylene resin series in unreactive hydrocarbons solvent (for example hexanaphthene etc.), add to use catalyst reduction such as aluminum alkyls cobalt or nickel etc., under the temperature about 25～50 ℃, use 5～40kg/cm ³About hydrogen, under pressure, react about 10～60 minutes.

The love Er Mendaofu tear strength of surface protective plate of the present invention is more than the 50g.

Like that the Er Mendaofu tear strength is the value of measuring according to JIS-P-8116.Be more than the 50g by the love Er Mendaofu tear strength that makes surface protective plate, just can form the surface protective plate of tear strength excellence.

Surface protective plate of the present invention can utilize the coetrusion film forming to obtain substrate layer and bonding coat by using the formation material that forms above-mentioned substrate layer and the formation material that forms above-mentioned bonding coat.Surface protective plate of the present invention is because substrate layer comprises the white color system layer at least and black is 2 layers on layer; therefore the formation material that forms substrate layer is more than 2 kinds; so; surface protective plate of the present invention can be by the formation material more than 2 kinds that use to form substrate layer and the formation material that forms bonding coat, with substrate layer and bonding coat multilayer utilize the coetrusion film forming to obtain.

Formation as surface protective plate of the present invention is not particularly limited, and can adopt any one formation of " white color system layer/black system layer/bonding coat ", " black system layer/white color system layer/bonding coat ".In addition, as substrate layer, also can be made as the layer more than 3 layers that has formed black system layer and white color system layer layer in addition and constitute.Specifically, also can be made as formations such as " transparent resin layers/white color system layer/black system layer/bonding coat ".In addition, the thickness of white color system layer and black system layer both can be identical, also can be different thickness (the white color system layer than the black system thin thickness of layer constitute, the white color system layer is that the thickness of bed thickness constitutes than black).

As coetrusion, can wait to carry out according to blow moulding, the T die head method generally used in the thin film fabrication etc.Can implement above-mentioned surface treatment to substrate layer and bonding coat as required.

For bonding coat, also can be as required, before being used for practical application during, attach barrier film etc. temporarily and protected.And, the face of not setting up bonding coat for substrate layer, be easy to the purposes such as coiling body of uncoiling for formation, for example also can carry out the demoulding and handle or arrange the coating layer that comprises suitable stripper such as silicone-based, chain alkyl system, fluorine system by in substrate layer, adding fatty acid amide or polymine etc.

Embodiment

Below, utilize the present invention of embodiment to be specifically described, yet the present invention is not subjected to any restriction of these embodiment.

[embodiment 1]

To add in the polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) 20 weight % white pigment (corporate system, HCM2035W refine big day) and the white layer of base material form material and add in the polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) 2 weight % carbon black (Mitsubishi Chemical's system, carbon black " #45 ") and the black layer of base material form a material use T die head coextrusion (extruder temperature: 200 ℃, die head temperature: the 200 ℃) film forming that is shaped, obtain the white black bilayer film A shown in the table 2 (white layer/black layer=20 μ m/20 μ m).

Black layer side to film A implemented corona treatment; coating adhesive composition on this treated side; produce surface protective plate; this binder composition is that to add the rosin series hydrogenating glycerol ester (85 ℃ of softening temperatures) of 36 weight %, the calcium carbonate of 3 weight %, the phenol of 0.6 weight % in the polymkeric substance 1 shown in the table 1 be protective agent, is dissolved in the toluene and gets (solids component 60 weight %).

The thickness of the substrate layer of the surface protective plate of gained is 40 μ m, and the thickness of bonding coat is 15 μ m.

[embodiment 2]

Making is with polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) 60 weight parts, high density polyethylene(HDPE) (Tosoh corporate system, NIPOLON HARD 5700) 40 weight parts mix and base material shaped polymer material, white pigment (the corporate system of refining big day of 20 weight % will be added in this base material shaped polymer material, HCM2035W) and the white layer of base material form material, with to polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) add carbon black (Mitsubishi Chemical's system of 2 weight % in, carbon black " #45 ") and the black layer of base material form a material use T die head coextrusion (extruder temperature: 200 ℃ that is shaped, die head temperature: 200 ℃) film forming obtains the white black bilayer film B shown in the table 2 (white layer/black layer=20 μ m/20 μ m).

Black layer side to film B implemented corona treatment; coating adhesive composition on this treated side; produce surface protective plate; this binder composition is that to add the aliphatics petroleum resin (100 ℃ of softening temperatures) of 20 weight %, the aliphatics petroleum resin (40 ℃ of softening temperatures) of 30 weight %, the phenol of 0.5 weight % in the polymkeric substance 2 shown in the table 1 be protective agent, is dissolved in the toluene and gets (solids component 60 weight %).

The thickness of the substrate layer of the surface protective plate of gained is 40 μ m, and the thickness of bonding coat is 10 μ m.

[embodiment 3]

Making is with high density polyethylene(HDPE) (Tosoh corporate system; NIPOLON HARD 5700) 80 weight parts; and Low Density Polyethylene (Tosoh corporate system; Petrocene 225) 20 weight parts mix and base material shaped polymer material; white pigment (the corporate system of refining big day of 20 weight % will be added in this base material shaped polymer material; HCM2035W) and the white layer of base material form material; to polypropylene (bright dipping petroleum chemistry corporate system; F-744NP) add carbon black (Mitsubishi Chemical's system of 2 weight % in; carbon black " #45 ") and the black layer of base material form a material; bonding coat that get forms material use T die head coextrusion shaping (extruder temperature: 200 ℃ with the binder composition that will obtain among the embodiment 2 (removing toluene) usefulness kneader is mixing with 150 ℃ * 20 minutes; die head temperature: 200 ℃) film forming obtains surface protective plate (white layer/black layer/bonding coat=22 μ m/22 μ m/15 μ m).

[embodiment 4]

Making is with high density polyethylene(HDPE) (Tosoh corporate system, NIPOLON HARD 5700) 80 weight parts, and Low Density Polyethylene (Tosoh corporate system, Petrocene 225) 20 weight parts mix and base material shaped polymer material, white pigment (the corporate system of refining big day of 20 weight % will be added in this base material shaped polymer material, HCM2035W) and the white layer of base material form material, with to polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) add carbon black (Mitsubishi Chemical's system of 2 weight % in, carbon black " #45 ") and the black layer of base material form a material use T die head coextrusion (extruder temperature: 200 ℃ that is shaped, die head temperature: 200 ℃) film forming obtains the white black bilayer film C shown in the table 2 (white layer/black layer=20 μ m/20 μ m).

Black layer side to film C implemented corona treatment; coating adhesive composition on this treated side; produce surface protective plate; this binder composition is the aliphatics petroleum resin (100 ℃ of softening temperatures) that add 33 weight % in the polymkeric substance 3 shown in the table 1, is dissolved in the toluene and gets (solids component 60 weight %).

[embodiment 5]

As binder composition; used the following binder composition that obtains; namely; suitable to the polymkeric substance of forming with shown in the table 12, and the ratio of three blocks of A/B/A and the diblock of A/B is in 80: 20 the polymkeric substance, adds the aliphatic petroleum resin (100 ℃ of softening temperatures) of 42 weight %; be dissolved in the toluene and get (solids component 60 weight %); in addition, carry out with the method identical with embodiment 1, produce surface protective plate.

[comparative example 1]

Use is carried out radical polymerization and is obtained polymkeric substance by the monomer component that butyl acrylate 100 weight parts, methyl methacrylate 10 weight parts and vinylformic acid 2 weight parts constitute.The weight-average molecular weight of this polymkeric substance (Mw) is 500,000, Mw/Mn=4.This polymer dissolution in toluene and form binder composition (solids component 30 weight %), except use this tackiness agent as binder composition, is carried out with the method identical with embodiment 1, produce surface protective plate.

[comparative example 2]

Making is with high density polyethylene(HDPE) (Tosoh corporate system, NIPOLON HARD 5700) 40 weight parts, and vinyl-vinyl acetate copolymer (EVA) (Tosoh corporate system, Ultrathene 515) 60 weight parts mix and base material shaped polymer material, white pigment (the corporate system of refining big day of 20 weight % will be added in this base material shaped polymer material, HCM2035W) and the white layer of base material form material, with to polypropylene (bright dipping petroleum chemistry corporate system, F-744NP) add carbon black (Mitsubishi Chemical's system of 2 weight % in, carbon black " #45 ") and the black layer of base material form a material use T die head coextrusion (extruder temperature: 200 ℃ that is shaped, die head temperature: 200 ℃) film forming obtains the white black bilayer film D shown in the table 2 (white layer/black layer=20 μ m/20 μ m).

Black layer side to film D implemented corona treatment, and the binder composition that obtains in this treated side coating embodiment 1 is produced surface protective plate.

[comparative example 3]

Except when the making of the film A of embodiment 1; do not carry out white pigment in the base material and the interpolation of carbon black; only produce beyond 1 layer the substrate layer that is constituted by polypropylene (bright dipping petroleum chemistry corporate system, F-744NP); carry out with the method identical with embodiment 1, produce surface protective plate.

[evaluation test]

(extrusion condition)

Forcing machine

Barrel diameter: 50mm φ

·L/D：20

Die head

Use the T die head

Die lip: 1mm

Molding condition

Draw rate: 20mm/ minute

Extrusion temperature: 220 ℃

(the initial stage Young's modulus of substrate layer bonding coat)

According to JIS-K-7127.The results are shown in Table 3.

(liking the Er Mendaofu tear strength)

According to JIS-P-8116.The results are shown in Table 3.

(hand paste operability)

The easness of the generation of the fold during according to coating surface screening glass on the stainless steel plate of 10cm * 10cm or skew easness are judged.The results are shown in Table 3.

(strip operation)

Resistance to tearing when peeling off rapidly from the angle part according to the surface protective plate of the product of will fitting is judged.The results are shown in Table 3.

(mensuration of weathering resistance)

The surface protective plate that obtains in embodiment and the comparative example is cut into the rectangle of wide 20mm and produces the evaluation sample.The roller by making 2kg 1 time and after being crimped on this sample on the SUS430BA plate back and forth, dropped in the sunlight carbon arc weather resistance test machine (Suga trier Co., Ltd. product) 1000 hours, then, peel off length to 100mm with 0.3m/ minute the end of draw speed along 180 ° of directions from sample.

According to the above-mentioned result of following benchmark evaluation.The results are shown in Table 3.

Zero: sample is not broken, can peel off very well.

*: because the deterioration of base material makes sample broken on the way, perhaps adhesive residue is in by adherend and with its pollution.

[table 1]

[table 2]

[table 3]

Can distinguish that according to table 3 surface protective plate of the present invention and various bounding force by adherend are good, the tear strength excellence; weathering resistance is very excellent; even in outdoor application or when at high temperature preserving, the increase of its bounding force also seldom, the separability when being peeled off by adherend is good.

Utilizability on the industry

Surface protective plate of the present invention can be used for following purposes etc.; namely; for example to metal sheet, application member such as metal sheet, aluminum alloy frame, resin board, decorative steel plate, vinylchlorid laminate steel, sheet glass carry, when processing or maintenance etc., be attached to these component surface and protected.

Claims

1. A surface protection sheet, which is formed with an adhesive layer on one side of the substrate layer,

The substrate layer is a polyolefin-based resin layer having an initial elastic modulus of 5000 kg/cm ^{or more} as measured by JIS-K-7127,

The base material layer includes at least two layers of a white color layer and a black color layer,

The adhesive layer is a styrene-based resin layer having an initial modulus of elasticity of 1 to 50 kg/ ^cm2 as measured by JIS-K-7127,

The Elmendorf tear strength of this surface protection sheet is 50 g or more.