CN103254820A - Surface protection sheet - Google Patents

Abstract

The invention provides a surface protection sheet. The surface protection sheet has an excellent bonding operationality with a curved surface, has a very excellent weatherability, still has an enough slice strength even the surface protection sheet is disposed in a bonding state under a high-temperature outdoor condition for a long time, and can be easily peeled without damages or the like. The surface protection sheet is obtained through forming a bonding layer on one surface of a substrate layer, the substrate layer includes a white series layer containing 50-95wt% of polyethylene and 5-30wt% of titanium oxide, and a black series layer containing 50-99.9wt% of polyethylene and 0.1-5wt% of carbon black, and the initial yield point strength of the substrate layer having a thickness below 150mum is 15-50N/25mm.

Description

Surface protective plate

Technical field

The present invention relates to a kind of surface protective plate.Specifically, the present invention relates to following surface protective plate, that is, in excellence aspect the bonding operability of curved surface, weathering resistance, long-term separability after bonding, be suitable for the vehicle body of automobile or the coating protective of parts, coated steel plate etc. etc.

Background technology

Be loaded on truck or the ship and transfer at a distance when waiting to overseas etc. at the automobile that will finish application or its parts etc., require to have measure to prevent by suspended substances such as dust, rainwater or Shi Li, collide the damage of filming, loss of gloss or variable color etc. that thing etc. causes.

As this kind preventive measures, known to have wax be class coating material with the way of the thickness coating of 5～20 μ m.But being difficult to wax is to film to make uniform thickness, is difficult to obtain the same filming.Thus, just have the problem of making dirty easily, the problem of acidproof rain not.In addition, owing to extremely require great effort applying when removing with it of filming of wax system, therefore have the problem of the environmental problems such as processing of the use that causes solvent easily or waste liquid.

On the other hand, proposed various surface protective plates such as to use tread support membranes such as polyester filming of arranging that bonding coat forms.According to this kind thin slice mode, can overcome above-mentioned problem.But, under the high temperature outdoor conditions in the long-time purposes of placing, can be because of the rising of the bounding force of the reduction of the flexibility of thin slice or intensity, bonding coat etc., be difficult to go up from filming the problem of stripper surface screening glass and produce.

Also proposed to overcome by the intensity that improves tread support membrane the scheme (for example with reference to patent documentation 1) of problem of the reduction of the flexibility of the thin slice under the high temperature outdoor conditions or intensity.But, in this motion, along with the rising of the early strength of tread support membrane, reduce with the bonding operability of curved surface such as body of a motor car, thereby have the problem of the essential fundamental property of forfeiture.

The prior art document

Patent documentation

Patent documentation 1 Japanese kokai publication hei 7-118615 communique

Summary of the invention

The objective of the invention is to; a kind of surface protective plate is provided; the bonding operability excellence of itself and curved surface; and weathering resistance is very excellent; even under bonding state, be positioned over for a long time under the situation outside the high-temperature chamber; also can keep enough tab strength, can not have breakage etc. to peel off at an easy rate troublesomely.

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 comprises: contains the white color system layer of 50～95 weight % polyethylene and 5～30 weight % titanium oxide and contains 50～99.9 weight % polyethylene and the black of 0.1～5 weight % carbon black system layer,

The yield point strength at initial stage is 15～50N/25mm during the thickness of this substrate layer below 150 μ m.

In preferred embodiment, above-mentioned substrate layer contains UV light absorber with the ratio of 0.1～2 weight %.

In preferred embodiment, above-mentioned yield point strength is 20～35N/25mm.

According to the present invention; a kind of surface protective plate can be provided; the bonding operability excellence of itself and curved surface; and weathering resistance is very excellent; even under bonding state, be positioned over for a long time under the situation outside the high-temperature chamber; also can keep enough tab strength, can not have breakage etc. to peel off at an easy rate troublesomely.

Embodiment

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

Substrate layer comprises specific white color system layer at least and specific black is 2 layers on layer.Like this; just can provide following surface protective plate; the bonding operability excellence of itself and curved surface; and weathering resistance is very excellent; even under bonding state, be positioned over for a long time under the situation outside the high-temperature chamber; also can keep enough tab strength, can not have breakage etc. to peel off at an easy rate troublesomely.

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 comprises titanium oxide.The proportional composition with respect to formation white color system layer that contains of the titanium oxide in the white color system layer is preferably 5～30 weight %, more preferably 6～20 weight %, more preferably 6～15 weight %.If containing of the titanium oxide in the white color system layer proportionally will lack opacifying power less than 5 weight %, substrate layer or bonding coat might suffer deterioration because of ultraviolet ray.If the titanium oxide in the white color system layer contain the proportional 30 weight % that surpass, then might lack plasticities such as extrudability.

The white color system layer comprises polyethylene.Poly in the white color system layer contains and proportionally is preferably 50～95 weight % with respect to the composition that forms the white color system layer, 60～95 weight % more preferably, and more preferably 65～95 weight % are preferably 70～95 weight % especially.If it is proportional less than 50 weight % that poly in the white color system layer contains, then might lack intensity and be wanting at strip operation.If poly in the white color system layer contains the proportional 95 weight % that surpass, then intensity becomes excessive and lacks flexibility, might be wanting at the curved surface cementability.

As polyethylene contained in the white color system layer, can adopt appropriate arbitrarily polyethylene.As this kind polyethylene, specifically, for example can enumerate high density polyethylene(HDPE) (HDPE), Low Density Polyethylene (LDPE), linear low density polyethylene (LLDPE).This kind polyethylene both can only use a kind, also can use more than 2 kinds.

And the density of high density polyethylene(HDPE) is preferably 0.94g/cm ³More than.In addition, the density of Low Density Polyethylene (LDPE) or linear low density polyethylene Low Density Polyethylenes such as (LLDPE) is preferably 0.88～0.93g/cm ³, 0.895～0.920g/cm more preferably ³

In the white color system layer, also can contain appropriate other resins arbitrarily beyond the polyethylene.As other resins of this kind, be preferably polyethylene polyolefin resin in addition, more preferably polypropylene.

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 comprises carbon black.Carbon black in the black system layer contain proportional to be 0.1～5 weight % with respect to the composition that forms black system layer, to be preferably 0.1～3 weight %, more preferably 0.1～1 weight %.If containing of the carbon black in the black system layer is proportional less than 0.1 weight %, then might give enough weathering resistances to the surface protective plate of gained.If the carbon black in the black system layer contain the proportional 5 weight % that surpass, then might lack plasticities such as extrudability.

Black system layer comprises polyethylene.Poly in the black system layer contains and proportionally is preferably 50～99.9 weight % with respect to the composition that forms black system layer, 60～99 weight % more preferably, and more preferably 70～99 weight % are preferably 80～99 weight % especially.If it is proportional less than 50 weight % that poly in the black system layer contains, then might lack intensity and be wanting at strip operation.If poly in the black system layer contains the proportional 99.9 weight % that surpass, then intensity becomes excessive and lacks flexibility, might be wanting at the curved surface cementability.

As contained polyethylene in the black system layer, can adopt appropriate arbitrarily polyethylene.As this kind polyethylene, specifically, for example can enumerate high density polyethylene(HDPE) (HDPE), Low Density Polyethylene (LDPE), linear low density polyethylene (LLDPE).This kind polyethylene both can only use a kind, also can use more than 2 kinds.

In black system layer, also can contain appropriate other resins arbitrarily beyond the polyethylene.As other resins of this kind, be preferably polyethylene polyolefin resin in addition, more preferably polypropylene.

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.

Substrate layer preferably comprises UV light absorber.The proportional composition with respect to the formation substrate layer that contains of the UV light absorber in the substrate layer is preferably 0.1～2 weight %, more preferably 0.2～1.5 weight %, more preferably 0.3～1.0 weight %.If containing of the UV light absorber in the substrate layer is proportional less than 0.1 weight %, then substrate layer or binder layer might suffer deterioration because of ultraviolet ray, if the UV light absorber in the substrate layer contain the proportional 2 weight % that surpass, then UV light absorber is oozed out to the substrate layer surface easily and might be produced powder phenomenon-tion etc.

As UV light absorber, for example can adopt benzotriazole is that UV light absorber, hindered amine are that UV light absorber, benzoic ether are appropriate UV light absorber arbitrarily such as UV light absorber.Concrete example as this kind UV light absorber, for example can enumerate 2-(the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole, 2-(3,5-, two-tertiary butyl-2-hydroxy phenyl)-5-chlorobenzotriazole, it is poly-that [{ 6-(1,1,3, the 3-tetramethyl butyl) amino-1,3,5-triazines-2,4-two bases } { (2,2,6,6-tetramethyl--4-piperidyl) imido grpup } hexa-methylene { (2,2,6,6-tetramethyl--4-piperidyl) imido grpup }], Succinic acid dimethylester 1-(2-hydroxyethyl)-4-hydroxyl-2,2,6,6-tetramethyl piperidine polycondensate, 2,4-, two-tert-butyl-phenyl-3,5-two-tertiary butyl-4-hydroxy benzoic ether etc.

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; Hindered amine is photostabilizers such as photostabilizer; The anti-electrostatic agent interfering; Weighting agents such as calcium oxide, magnesium oxide, silicon-dioxide, zinc oxide; Pigment; Preventing materials accumulation agent (order ヤ ニ prevents drug); Lubricant; Anti; Whipping agent; Polymine etc.

The thickness of substrate layer is preferably 10～150 μ m, more preferably 20～100 μ m, more preferably 30～50 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.

The yield point strength at initial stage is 15～50N/25mm during the thickness of substrate layer below 150 μ m, is preferably 20～35N/25mm.If this kind yield point strength less than 15N/25mm, then lacks intensity and makes a little less than the stiffness (from supporting), when bonding operation, introduce fold easily, might become the material of strip operation difference.If this kind yield point strength surpasses 50N/25mm, then lack flexibility, might make the bonding operability variation with curved surface.The yield point strength at the initial stage of substrate layer is based on method mensuration described later among the present invention.

Formation method as substrate layer can adopt appropriate methods arbitrarily.As this kind formation method, specifically, can enumerate films such as T die head method, blow moulding.

Tackiness agent used in the bonding coat can adopt appropriate arbitrarily tackiness agent.As this kind tackiness agent, for example can enumerate known rubber and be tackiness agent, acrylic adhesive, polyester and be tackiness agent, polyurethane series tackiness agent, polyisobutene is tackiness agent, polystyrene tackiness agent, ethylene series tackiness agent etc.

When forming binder layer, for purposes such as control adhesion characteristics, as required, for example can suitably add tenderizer, ethylene series resin, silicone-based polymkeric substance, aqueous acrylic copolymer, phosphoric acid ester based compound, 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, with respect to tackiness agent used in the bonding coat, be preferably below the 50 weight %, more preferably below the 30 weight %, more preferably below the 10 weight %.And, the application surface screening glass be under the situation of metal sheet by adherend, when forming bonding coat, preferably do not add tackifier.

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.For the use level of tenderizer, with respect to tackiness agent used in the bonding coat, be preferably below the 40 weight %, more preferably below the 20 weight %, more preferably below the 10 weight %.If the use level of tenderizer is more than the 40 weight % with respect to tackiness agent used in the bonding coat, then the glue trace when high temperature or outdoor exposure just might become obvious.

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.

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.

Surface protective plate of the present invention can utilize appropriate methods manufacturing arbitrarily.Surface protective plate of the present invention preferably by using the formation material that forms above-mentioned substrate layer and the formation material that forms above-mentioned bonding coat, utilizes coetrusion that substrate layer and bonding coat film forming are obtained.In addition, utilize with the tackiness agent of solution-type or emulsion-type to the method for the one side coating of substrate layer, will be formed at bonding coat on the barrier film to the method that the one side of substrate layer shifts, also can make surface protective plate of the present invention.

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 forms 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]

Will be with respect to high density polyethylene(HDPE) (the Tosoh system of MFR0.07, NIPOLON HARD6900) added Low Density Polyethylene (the Japanese polyethylene system of the MFR5 of 20 weight %, ノ バ テ Star Network LD-LF640MA), the white pigment of the 15 weight % (corporate system of refining big day, HCM2035W (titanium oxide concentration is 65 weight %)) (titanium oxide 9.75 weight %), and the 2-of 0.3 weight % (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and the white layer of base material form material; High density polyethylene(HDPE) (Tosoh system with respect to MFR0.07, NIPOLON HARD6900) added Low Density Polyethylene (the Japanese polyethylene system of the MFR5 of 20 weight %, ノ バ テ Star Network LD-LF640MA), the carbon black of 2 weight % (Mitsubishi Chemical's system, carbon black " #45 "), and the 2-of 0.3 weight % (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and the black layer of base material form a material, utilize blow moulding (240 ℃ of die head temperatures) coextrusion, black aspect to the substrate layer of the thick 30 μ m of gained (white layer/black layer=15 μ m/15 μ m) is carried out corona treatment, the coating polyisobutene is 20 weight % toluene solutions of tackiness agent on this corona treatment face, carry out 3 minutes drying treatment at 80 ℃, form the bonding coat of thick 10 μ m.Like this, produce surface protective plate.

The thickness of the substrate layer of the surface protective plate of gained is 30 μ m, and the thickness of bonding coat is 10 μ m.

[embodiment 2]

Use forms material with respect to the white layer of the 2-base material that (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-the 5-chlorobenzotriazole gets that the high density polyethylene(HDPE) (Tosoh system, NIPOLON HARD7300A) of MFR0.05 has added the homo-polypropylene (Japan polypropylene system, ノ バ テ Star Network PP-FY4) of the MFR5 of 10 weight %, the white pigment of 15 weight % (corporate system, HCM2035W (titanium oxide concentration is 65 weight %) refine big day) (titanium oxide 9.75 weight %) and 0.3 weight %; Added with respect to the high density polyethylene(HDPE) (Tosoh system, NIPOLON HARD 7300A) of MFR0.05 the carbon black (Mitsubishi Chemical's system, carbon black " #45 ") of homo-polypropylene (Japan polypropylene system, ノ バ テ Star Network PP-FY4), 2 weight % of the MFR5 of 10 weight % and 0.3 weight % 2-(the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and the black layer of base material form a material; carry out in the same manner with embodiment 1, produce surface protective plate.

The thickness of the substrate layer of the surface protective plate of gained is 30 μ m, and the thickness of bonding coat is 10 μ m.

[embodiment 3]

Will be with respect to high density polyethylene(HDPE) (the Tosoh system of MFR0.05, NIPOLON HARD7300A) added homo-polypropylene (the Japan polypropylene system of the MFR5 of 20 weight %, ノ バ テ Star Network PP-FY4), the Low Density Polyethylene of the MFR5 of 10 weight % (Japanese polyethylene system, ノ バ テ Star Network LD-LF640MA), the white pigment of the 15 weight % (corporate system of refining big day, HCM2035W (titanium oxide concentration is 65 weight %)) (titanium oxide 9.75 weight %), and the 2-of 0.3 weight % (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and the white layer of base material form material; High density polyethylene(HDPE) (Tosoh system with respect to MFR0.05, NIPOLON HARD7300A) added homo-polypropylene (the Japan polypropylene system of the MFR5 of 20 weight %, ノ バ テ Star Network PP-FY4), the Low Density Polyethylene of the MFR5 of 10 weight % (Japanese polyethylene system, ノ バ テ Star Network LD-LF640MA), the carbon black of 2 weight % (Mitsubishi Chemical's system, carbon black " #45 "), and the 2-of 0.3 weight % (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and the black layer of base material form a material, utilize blow moulding (240 ℃ of die head temperatures) coextrusion, black aspect to the substrate layer of the thick 25 μ m of gained (white layer/black layer=12.5 μ m/12.5 μ m) is carried out corona treatment, on this corona treatment face, be coated with acrylic adhesive, carry out 3 minutes drying treatment at 80 ℃, form the bonding coat of thick 5 μ m.Like this, produce surface protective plate.And, acrylic adhesive is to utilize well-established law to carry out aggregation processing in ethyl acetate 2-EHA 40 weight parts/ethyl propenoate 50 weight parts/vinylbenzene 9 weight parts/vinylformic acid 1 weight part, make the polymkeric substance of weight-average molecular weight 600,000, add trifunctional isocyanic ester 5 weight parts in this solution to prepare.

The thickness of the substrate layer of the surface protective plate of gained is 25 μ m, and the thickness of bonding coat is 5 μ m.

[comparative example 1]

Will be with respect to high density polyethylene(HDPE) (the Tosoh system of MFR1, NIPOLON HARD 5700) added high density polyethylene(HDPE) (the Tosoh system of the MFR0.05 of 45 weight %, NIPOLON HARD7300A), the white pigment of the 1 weight % (corporate system of refining big day, HCM2035W (titanium oxide concentration is 65 weight %)) (titanium oxide 0.65 weight %), and the 2-of 0.3 weight % (the 3-tertiary butyl-5-methyl-2-hydroxy phenyl)-5-chlorobenzotriazole and substrate layer form material, utilize blow moulding (240 ℃ of die head temperatures) coextrusion, under the condition of blow-up ratio 5, be shaped, one side to the substrate layer of the thick 25 μ m of gained (white layer=25 μ m) is carried out corona treatment, on this corona treatment face, be coated with the acrylic adhesive that obtains among the embodiment 3, carry out 3 minutes drying treatment at 80 ℃, form the bonding coat of thick 5 μ m.Like this, produce surface protective plate.

The thickness of the substrate layer of the surface protective plate of gained is 25 μ m, and the thickness of bonding coat is 5 μ m.

[evaluation test]

(yield point strength)

To the surface protective plate (wide 25mm) that obtains in embodiment, the comparative example, studied tensile strength (MD direction) under the condition of 50mm at interval draw speed 300mm/ minute, dop.In sample, the object (exposing in Thailand) that has used the initial stage thing and carried out atmospheric exposure test in 6 months in Thailand.This exposure test is that surface protective plate is bonded on the acrylic acid series cleaning coated plate (specifically; as aforesaid propylene acid system cleaning coated plate; for example can use following material; namely; surface of aluminum plate at thick 2mm; use spray gun to be coated with the aluminium wheel equably with acrylic melamine coating (Japanese Paint system, Superlac 5000AW-10 clear), 150 ℃ of dryings 1 hour and material etc.), it is arranged in the atmospheric exposure test platform, place 2 months～8 months during condition under carry out.The result is shown in the table 1.

(curved surface cementability)

Operability when having studied on the coated plate that the surface protective plate that will obtain in embodiment, the comparative example is bonded in radius 500cm is estimated according to following benchmark.The results are shown in Table 1.

Zero: do not produce fold and be easy to carry out bonding processing.

△: introduce fold easily, in the bonding processing that does not produce fold, need to be familiar with operation.

*: can't avoid introducing fold, be difficult to carry out bonding processing.

(long-term separability)

The surface protective plate that obtains in embodiment, the comparative example is bonded on the coated plate of radius 500cm, has studied it at the strip operation of outdoor exposure after 6 months, according to following standard evaluation.The results are shown in Table 1.

Zero: ground peeling sheet swimmingly can not rupture.

△: thin slice ruptures frequently and is difficult to peel off.

*: thin slice is very easy to fracture.

(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 1.

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]

Can distinguish according to table 1; the bonding operability excellence of surface protective plate of the present invention and curved surface; and weathering resistance is very excellent; even under bonding state, be placed on for a long time under the situation outside the high-temperature chamber; also can keep enough tab strength, breakage etc. can not take place peel off at an easy rate troublesomely.

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 (3)

1. surface protective plate, its one side at substrate layer is formed with bonding coat,

This substrate layer comprises: the white color system layer that contains the titanium oxide of the polyethylene of 50～95 weight % and 5～30 weight %; With; The black system layer that contains the carbon black of the polyethylene of 50～99.9 weight % and 0.1～5 weight %,

The yield point strength at initial stage is 15～50N/25mm during the thickness of this substrate layer below 150 μ m.

2. surface protective plate according to claim 1, wherein,

Described substrate layer contains UV light absorber with the ratio of 0.1～2 weight %.

3. surface protective plate according to claim 1, wherein,

Described yield point strength is 20～35N/25mm.