CN103254821A

CN103254821A - Surface protection sheet

Info

Publication number: CN103254821A
Application number: CN2012100362484A
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: WO2013121845A1

Abstract

The invention provides a surface protection sheet. The surface protection sheet is obtained through film co-extrusion of a substrate layer containing a polyolefin series resin and an adhesive layer containing a styrene series thermoplastic elastomer, has good adhesion with various adhered objects, has a very excellent weatherability, and has a very small adhesion increase and a good peeling property during the peeling of the surface protection sheet from the adhered objects even the surface protection sheet is used outside or is preserved at a high temperature. The surface protection sheet is obtained through the film co-extrusion of the substrate layer containing the polyolefin series resin and the adhesive layer containing the styrene series thermoplastic elastomer, the substrate layer at least includes a white series layer and a black series layer, the polyolefin resin is an ethylene series polymer having a density of 0.88-0.93g/cm<3>, and the styrene series thermoplastic elastomer is a styrene series segmented copolymer having a largest tandelta value at a temperature of -40 - -25DEG C obtained through the dynamic visco-elastic determination in a determination temperature range of -60-100DEG C or a hydride thereof.

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 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 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 surface protective plate.

In general, as the thermoplastic elastomer that can coextrusion be shaped, known have the cinnamic block polymer of styrene ethylene-butylene copolymer (SEBS), a cinnamic block polymer of styrene ethylene-propylene copolymer (SEPS) etc.These styrene block copolymers are had enough binding propertys to what have the smoother vinylbenzene plate that is adhered to dignity or a resin board etc. by the adherend mask.On the other hand, these styrene block copolymers lack binding property to the dignity that adhered to of the stainless steel plate (hairline plate) that carried out milled processed or asperities resin board etc.Thus; in general; in the bonding coat of the surface protective plate that is adhered to dignity that is adapted to this kind asperities resin board etc., in styrene block copolymer, add a large amount of tackifier or tenderizer etc., to regulate the bounding force (for example with reference to patent documentation 1, patent documentation 2) of bonding coat.

But, having the surface protective plate of a large amount of bonding coats that used tackifier etc. when at high temperature preserving in the warehouse in summer or in the freight container, its bounding force can increase in the relatively shorter time.The increase of this kind bounding force has and causes the problems such as bad of peeling off.In addition, be used at this kind surface protective plate that bounding force raise under the situation of flat runner etc., because of the influence of tackifier etc., can produce peel off bad.

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 the bonding coat that will contain the substrate layer of polyolefin-based resins and contain styrene series thermoplastic elastomer utilizes the coextrusion film forming; good with various bounding forces by adherend; weathering resistance is very outstanding; 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.

Surface protective plate of the present invention is the surface protective plate that the bonding coat that contains the substrate layer of polyolefin-based resins and contain styrene series thermoplastic elastomer is utilized the coextrusion film forming,

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

This polyolefin-based resins is density 0.88～0.93g/cm ³Ethylene-based polymer,

This styrene series thermoplastic elastomer is that the maximum temperature of tan δ value of the Measurement of Dynamic Viscoelasticity in-60～100 ℃ mensuration temperature range is-40～-25 ℃ styrene block copolymer or its hydride.

In preferred embodiment, 23 ℃ shearing storage elastic modulus of above-mentioned bonding coat is 1.0 * 10 ⁵～8.0 * 10 ⁵Pa.

In preferred embodiment, above-mentioned bonding coat contains tenderizer, and the number-average molecular weight of this tenderizer is 5000～100,000.

According to the present invention; a kind of surface protective plate can be provided; it is the surface protective plate that the bonding coat that will contain the substrate layer of polyolefin-based resins and contain styrene series thermoplastic elastomer utilizes the coextrusion film forming; good with various bounding forces by adherend; weathering resistance is very outstanding; 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.

Embodiment

The substrate layer that surface protective plate of the present invention will contain polyolefin-based resins utilizes the coextrusion film forming with the bonding coat that contains styrene series thermoplastic elastomer.

In the styrene series thermoplastic elastomer that forms bonding coat, the maximum temperature of tan δ value of using the Measurement of Dynamic Viscoelasticity in-60～100 ℃ mensuration temperature range is-40～-25 ℃ styrene block copolymer or its hydride.

Among the present invention, used styrene series thermoplastic elastomer in the formation as bonding coat uses the styrene block copolymer of the tan δ value of the maximum that demonstrates Measurement of Dynamic Viscoelasticity under than higher in the past temperature.Among the present invention, along with the temperature that shows maximum tan δ value raises, the binding property of bonding coat increases.In addition, be-40～-25 ℃ by the temperature regulation that will show maximum tan δ value, just can obtain the wetting property of appropriateness.Thus, even bonding coat of the present invention heavy addition tackifier etc. not also have enough wetting properties and binding property.So, can compress the interpolation of tackifier etc. seldom, thereby can suppress to peel off generation bad or the glue trace.Surface protective plate of the present invention with this kind bonding coat is by regulating the rerum natura of bonding coat, and is also bonding very well with uneven surface, even be applied under the situation on plane, can not produce yet peel off bad.In order to obtain more good wetting property and binding property, the maximum temperature of the tan δ value of above-mentioned Measurement of Dynamic Viscoelasticity is preferably-40～-30 ℃.Above-mentioned Measurement of Dynamic Viscoelasticity specifically according to be the record of embodiment.

Among the present invention, 23 ℃ shearing storage elastic modulus of bonding coat is preferably 1.0 * 10 ⁵～8.0 * 10 ⁵Pa.From considering with the fusible viewpoint of uneven surface, be preferably 1.5 * 10 as the shearing storage elastic modulus of 23 ℃ the bonding coat in applied temps zone ⁵～7.5 * 10 ⁵Pa, more preferably 2.0 * 10 ⁵～7.0 * 10 ⁵Pa.Above-mentioned shearing storage elastic modulus measure specifically according to be the record of embodiment.

As styrene block copolymer, for example can enumerate styrene butadiene styrene multipolymer (SBS), styrene isoprene styrol copolymer polystyrene ABA block polymer (triblock copolymer) such as (SIS); Styrene butadiene styrene butadienecopolymer (SBSB), styrene isoprene styrene isoprene multipolymer polystyrene ABAB type segmented copolymers (Tetrablock copolymer) such as (SISI); Styrene butadiene styrene butadienestyrene copolymer (SBSBS), styrene isoprene styrene isoprene styrol copolymer polystyrene ABABA type segmented copolymers (five segmented copolymers) such as (SISIS); Has the styrene block copolymer of the AB repeating unit more than this etc.

In addition, as styrene block copolymer, the preferred hydride that has used the two key hydrogenations of ethylenic.As this kind styrene block copolymer, for example can enumerate the multipolymer (SEBSEB) of styrene ethylene-butylene copolymer styrol copolymer (SEBS), styrene ethylene-propylene copolymer styrol copolymer (SEPS), styrene ethylene-butylene copolymer styrene ethylene-butylene copolymer etc.

Styrene block copolymer both can only use a kind, also can use more than 2 kinds.

Styrene block content in the styrene block copolymer can suitably be set at appropriate arbitrarily amount, is the styrene block content of above-mentioned scope yet use the maximum temperature of tan δ value of above-mentioned Measurement of Dynamic Viscoelasticity.As a rule, if styrene block content tails off, then might be easy to generate the glue trace that the cohesive force deficiency by bonding coat causes.On the other hand, many if styrene block contains quantitative change, then the bonding coat hardening that forms separately with styrene block copolymer might can't obtain good binding property at uneven surface.From then on plant viewpoint and consider that the styrene block content in the styrene block copolymer is preferably 5～40 weight %, more preferably 7～30 weight %, more preferably 9～20 weight %.

In the middle of styrene block copolymer, preferably has the hydride (SEBS, SEBSEB, SEBSEBS etc.) of the styrene block copolymer of the repeating unit (ABA type, ABAB type, ABABA type etc.) more than the triblock copolymer that is constituted by vinylbenzene (A) and divinyl (B).In order to obtain good wetting property and binding property, the ratio of shared butylene structure is preferably more than the 60 weight % in the ethylene-butene copolymer block in the hydride of styrene block copolymer, more preferably more than the 70 weight %, more preferably more than the 75 weight %.The ratio of shared butylene structure is 60 weight % when above in the ethylene-butene copolymer block in the hydride of styrene block copolymer, and wetting property is good, and particularly binding property is good, and is bonding well with uneven surface.And the ratio of shared butylene structure as a rule is preferably below the 90 weight % in the ethylene-butene copolymer block in the hydride of styrene block copolymer.

For styrene block copolymer, can in the scope of not damaging purpose of the present invention, mix other styrene series thermoplastic elastomer for purposes such as adjusting binding propertys.

As other styrene series thermoplastic elastomer, can enumerate above-mentioned styrene block copolymer in addition; The multipolymer (SEB) of styrene-butadiene-copolymer (SB), styrene isoprene multipolymer (SI), styrene ethylene-butylene copolymer, the multipolymer AB type block polymers such as (SEP) of styrene ethylene-propylene copolymer; Styrene butadiene ribber polystyrene random copolymerss such as (SBR); The vinylbenzene alkene crystal system block polymer of the multipolymer A-B-C types such as (SEBC) of styrene ethylene-butylene copolymer alkene crystal; Their hydride etc.

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 the styrene series thermoplastic elastomer that comprises styrene block copolymer, be preferably below the 40 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, preferably when forming bonding coat, 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.

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 containing the styrene series thermoplastic elastomer that comprises polystyrene type segmented copolymer and the binder composition of tenderizer, be preferably below the 40 weight %, more preferably below the 20 weight %, more preferably below the 10 weight %.And, the application surface screening glass be under the situation of metal sheet by adherend, preferably when forming bonding coat, do not add tenderizer.

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.

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 considerations such as membrane stability, burning, preferred Low Density Polyethylene (LDPE), linear low density polyethylene ethylene-based polymers such as (LLDPE).In order to give bendability to substrate layer, preferably must use linear low density polyethylene (LLDPE).

Contained polyolefin-based resins is preferably density 0.88～0.93g/cm in the substrate layer ³Ethylene-based polymer.This kind density is 0.895～0.920g/cm more preferably ³

Substrate layer comprises the white color system layer at least and black is 2 layers on layer.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 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 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 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 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.

Surface protective plate of the present invention is to form above-mentioned formation material and the above-mentioned formation material that contains the bonding coat of styrene series thermoplastic elastomer of formation that contains the substrate layer of polyolefin-based resins by using, and utilizes coetrusion that substrate layer and bonding coat film forming are obtained.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 is by the formation material more than 2 kinds that use to form substrate layer and forms the formation material of 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 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 straight chain shape Low Density Polyethylene (Mitsui Chemicals corporate system; EVOLUE SP2020) added the white pigment (corporate system of refining big day of 20 weight %; HCM2035W); and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight % and back side substrate layer form material; with respect to Low Density Polyethylene (Tosoh corporate system; Petrocene 180) carbon black (Mitsubishi Chemical's system of having added 1 weight %; carbon black " #45 ") and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight % and middle substrate layer formation material; with by the cinnamic block polymer of styrene ethylene-butylene copolymer (Asahi Chemical Industry's corporate system; Tuftec H1221; maximum tan δ temperature=-32 ℃) bonding coat that constitutes forms material; utilize blow moiding method in 240 ℃ of following film forming of die head temperature, obtain surface protective plate.At this moment, the thickness of back side substrate layer is 20 μ m, and the thickness of middle substrate layer is 90 μ m, and the thickness of bonding coat is 5 μ m.

And the density of straight chain shape Low Density Polyethylene (Mitsui Chemicals corporate system, EVOLUE SP2020) is 0.916g/cm ³, the density of Low Density Polyethylene (Tosoh corporate system, Petrocene 180) is 0.922g/cm ³

In addition, the styrene content of the block polymer of styrene ethylene-butylene co polystyrene (Asahi Chemical Industry's corporate system, Tuftec H1221) is 12 weight %, and butylene structure shared ratio in the ethylene-butene copolymer block is 76 weight %.

[embodiment 2]

Will be with respect to Low Density Polyethylene (Tosoh corporate system; Petrocene 173) white pigment (corporate system of refining big day of having added 20 weight %; HCM2035W); and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight % and back side substrate layer form material; with respect to Low Density Polyethylene (Tosoh corporate system; Petrocene 180) carbon black (Mitsubishi Chemical's system of having added 1 weight %; carbon black " #45 ") and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight % and middle substrate layer formation material; with with respect to the cinnamic block polymer of styrene ethylene-butylene copolymer (Asahi Chemical Industry's corporate system; Tuftec H1221; maximum tan δ temperature=-32 ℃) added petroleum resin (the waste river chemical company system of 5 weight %; Alcon P-100) and bonding coat form material use T die head method in 230 ℃ of following film forming of die head temperature, obtain surface protective plate.At this moment, the thickness of back side substrate layer is 10 μ m, and the thickness of middle substrate layer is 50 μ m, and the thickness of bonding coat is 10 μ m.

And the density of Low Density Polyethylene (Tosoh corporate system, Petrocene 173) is 0.924g/cm ³

[embodiment 3]

Will be with respect to straight chain shape Low Density Polyethylene (Mitsui Chemicals corporate system; EVOLUE SP2020) added 20 weight % from the look pigment (corporate system of refining big day; HCM2035W); and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight % and back side substrate layer form material; with respect to Low Density Polyethylene (Tosoh corporate system; Petrocene 180) carbon black (Mitsubishi Chemical's system of having added 1 weight %; carbon black " #45 "); and the two stearic amides (Japan changes into corporate system) of the ethene of 0.5 weight part and substrate layer form material; with by the cinnamic block polymer of styrene ethylene-butylene copolymer (JSR corporate system; Dynaron 8600P; maximum tan δ temperature=-39 ℃) bonding coat that constitutes forms material use T die head method in 220 ℃ of following film forming of die head temperature, obtains surface protective plate.At this moment, the thickness of back side substrate layer is 20 μ m, and the thickness of middle substrate layer is 90 μ m, and the thickness of bonding coat is 10 μ m.

And the styrene content of the cinnamic block polymer of styrene ethylene-butylene copolymer (JSR corporate system, Dynaron 8600P) is 15 weight %, and butylene structure shared ratio in the ethylene-butene copolymer block is 67 weight %.

[comparative example 1]

Except in embodiment 1; form material as bonding coat; the cinnamic block polymer of substituted phenylethylene ethylene-butene copolymer (Asahi Chemical Industry's corporate system, Tuftec H1221, maximum tan δ temperature=-32 ℃); and used the cinnamic block polymer of styrene ethylene-butylene copolymer (ShellElastomer corporate system, Kraton G1657, maximum tan δ temperature=-50 ℃) in addition; utilize the method identical with embodiment 1, make surface protective plate.

In addition, the styrene content of the cinnamic block polymer of styrene ethylene-butylene copolymer (Shell Elastomer corporate system, Kraton G1657) is 13 weight %.

[comparative example 2]

Except in embodiment 1; form material as bonding coat; the cinnamic block polymer of substituted phenylethylene ethylene-butene copolymer (Asahi Chemical Industry's corporate system; Tuftec H1221; maximum tan δ temperature=-32 ℃); and used with respect to the cinnamic block polymer of styrene ethylene-butylene copolymer (Shell Elastomer corporate system; Kraton G1657; maximum tan δ temperature=-50 ℃) added petroleum resin (the waste river chemical company system of 5 weight %; Alcon P-100) and bonding coat form beyond the material; utilize the method identical with embodiment 1, make surface protective plate.

[comparative example 3]

Except in embodiment 2; form material as bonding coat; the cinnamic block polymer of substituted phenylethylene ethylene-butene copolymer (Asahi Chemical Industry's corporate system; Tuftec H1221; maximum tan δ temperature=-32 ℃); and used with respect to the cinnamic block polymer of styrene ethylene-propylene copolymer ((strain) Kuraray system; Septon 2063; maximum tan δ temperature=-51 ℃) added petroleum resin (the waste river chemical company system of 5 weight %; Alcon P-100) and bonding coat form beyond the material; utilize the method identical with embodiment 2, make surface protective plate.

In addition, the styrene content of the cinnamic block polymer of styrene ethylene-propylene copolymer ((strain) Kuraray system, Septon 2063) is 13 weight %.

[comparative example 4]

Except in embodiment 1, do not carry out beyond the interpolation in the base material of white pigment and carbon black, utilize the method identical with embodiment 1, make surface protective plate.

[evaluation test]

(mensuration of maximum tan δ temperature and storage elastic modulus)

The temperature that the tan δ value of the Measurement of Dynamic Viscoelasticity in the bonding coat for surface protective plate in-60～100 ℃ the mensuration temperature range of each used styrene block copolymer is maximum and 23 ℃ shearing storage elastic modulus of bonding coat; be when the ARES that uses Rheometric Scientific corporate system gives the shear of frequency of 1Hz, give-60～150 ℃ temperature variation (5 ℃ of heat-up rates/min) measure.The bonding coat that the mensuration sample is made about thick 5mm is measured.Making of bonding coat is to utilize the casting method of organic solvent or pressure sintering to carry out.And, can not carry out in these methods under the situation of mensuration of shearing storage elastic modulus of bonding coat, also can measure with method such as obtain according to the difference of the shearing storage elastic modulus of the shearing storage elastic modulus of surface protective plate and base material.The results are shown in Table 1.

(mensuration of bounding force)

Determine the bounding force of the surface protective plate that obtains in embodiment and the comparative example according to JIS-Z-0237.Specifically, as used SUS304BA plate (smooth-flat-surface), SUS304HL plate (milled processed surface) by adherend.Clean SUS plate surface with toluene after, with the crimping of 2kg roller, through after 30 minutes with internally-oriented tensile testing machine (Shimadzu Seisakusho Ltd.'s corporate system, Autograph), spend to peel off with 300mm/ minute draw speed, 180 and measure.At this moment, be at 23 ℃/50% mensuration environment and preserve under the environment and carry out.As the bounding force after heat-resisting, will in 23 ℃/50% SUS304BA plate that has attached is being set at 80 ℃ drying machine, place 14 days after, placed 2 hours 23 ℃/50%, measure 23 ℃/50% same as described abovely.The results are shown in Table 1.

(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 confirm that according to table 1 surface protective plate weathering resistance of the present invention is very outstanding, for having carried out the also very good by the bounding force of adherend of milled processed, even and in the rising of heat-resisting bounding force down also seldom, through the time separability 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. surface protective plate, it is that the bonding coat that will contain the substrate layer of polyolefin-based resins and contain styrene series thermoplastic elastomer utilizes the coextrusion film forming,

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

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

Shearing storage elastic modulus under 23 ℃ of described bonding coat is 1.0 * 10 ⁵～8.0 * 10 ⁵Pa.

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

Described bonding coat contains tenderizer, and the number-average molecular weight of this tenderizer is 5000～100,000.