DESCRIPTION HEAT SHRINKABLE MULTILAYER FILM AND HEAT SHRINKABLE LABEL TECHNICAL FIELD [0001] The present invention relates to a heat-shrinkable multilayer film which, in the case of using the heat-shrinkable multilayer film as a heat-shrinkable label for a container, does not produce delamination in covering a container, is superior in heat resistance, oil resistance, tearing properties along the perforation and appearance and can prevent the reduction in strength between the layers after a printing step, and a heat-shrinkable label conprising the heat-shrinkable multilayer film as a base film. BACKGROUND ART [0002] In recent years, many containers such as PET bottles and metal cans are covered with heat-shrinkable labels prepared by performing printing on a base film of a heat-shrinkable resin film. As such a heat-shrinkable resin film, films comprising polystyrene type resin predominate since it is superior in low temperature shrinkability. However, since the polystyrene type resin film has inadequate heat resistance, there was a problem that for example, the heat-shrinkable resin label may be shrunk and the label may be distorted or broken when a PET bottle topples in being heated in a hot warmer equipped in a convenience store, and the like. Furthermore, the polystyrene type resin film also has a problem that since it has inadequate solvent resistance, it may be shrunk or dissolved by the adhesion of oils when it is used for the packaging of articles containing oils. [0003] On the other hand, efforts to use a polyester type film, which is superior in heat resistance and solvent resistance, in place of a polystyrene type resin film as a heat-shrinkable label are made. But, the polyester type film has a problem that it tends to produce crinkles when it covers a container since it has bad low temperature shrinkability and is shrunk rapidly. Further, perforation for tearing off is often provided on the shrink film so that the heat-shrinkable label can be easily torn off and removed from the used container in order to recycle containers, but in the polyester type film, there was also a problem that tearing properties along the perforation are poor, and therefore the heat-shrinkable label cannot be easily torn off and removed from the container. Furthermore, in the polyester type film, there was a problem that since it has large shrinking stress, in the case of using the polyester type film as a label for hot beverages, the label shrinks and compresses the container due to heating of the beverages at the time of sale and thereby a level of the content of the container rises to cause the content to spill over the container. [0004] For this situation, in Patent Document 1, a hard multilayer shrinkable film obtainable by laminating outer surface layers comprising a polyester type resin on an intermediate layer comprising a polystyrene type resin with an adhesive layer comprising an olefin type resin interposed between the outer surface layer and the intermediate layer, is disclosed. Further, in Patent Document 2, a heat-shrinkable label, which includes a base film obtainable by laminating outer surface layers comprising a polyester type resin comprising a specific monomer on both sides of an intermediate layer comprising a polystyrene type resin, and by laminating the outer surface layers and the intermediate layer without an adhesive layer interposed between the outer surface layer and the intermediate layer, is disclosed. Furthermore, in Patent Document 3, a laminated film having a surface layer comprising a polyester type resin, an intermediate layer comprising a styrene type resin and an adhesive layer comprising an adhesive resin, is disclosed. The heat-shrinkable labels comprising these multilayer films are superior in low temperature shrinkability and tearing properties along the perforation by the virtue of the intermediate layer comprising a polystyrene type resin, and further they are also superior in solvent resistance and heat resistance since the intermediate layer is covered with the outer surface layers comprising a polyester type resin. [0005] However, if these heat-shrinkable labels cover the containers actually, there were problems that in the hard multilayer shrinkable film described in Patent Document 1, the intermediate layer may be peeled off from the outer surface layer in covering the container, and in the heat-shrinkable label described in Patent Document 2, after covering the container with the heat-shrinkable label, if the films rub against each other during t ransportation of products or the film is scratched with a fingernail or a body, peeling may occur between an intermediate layer and an outer surface layer. Further, when the heat-shrinkable labels are used for PET bottles for drinking, decoration of labels is performed by printing for the purpose of differentiating products from those of other companies or enhancing images of user. However, since printing ink used in a pointing step of the label generally contains an organic solvent, a trace of the organic solvent remains on the printed surface after printing and drying. Thereby, a problem that when the heat-shrinkable film described in Patent Document 3 is used, an adhesive property between the outer surface layer and the intermediate layer is affected by a residual organic solvent and adhesion strength between the outer surface layer and the intermediate layer after a printing step is significantly recuced in comparison with that before the printing step has newly arisen. Accordingly, a heat-shrinkable multilayer film, which, in the case of using the heat-shrinkable multilayer film as a heat-shrinkable label for a container, does not produce peel between the outer surface layer and the intermediate layer in covering a container, is superior in heat resistance, oil resistance, tearing properties along the perforation and appearance, is less-affected by an organic solvent used in a printing step and has adequate adhesion strength after the printing step, has been required. Patent Document 1: Japanese Kokai Publication Sho-61-41543 Patent Document 2: Japanese Kokai Publication 2002-351332 Patent Document 3: Japanese Kokai Publication 2006-15745 DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION [0006] In view of the above state of the art, it is an object of the present invention to provide a heat-shrinkable multilayer film which, in the case of using the heat-shrinkable multilayer film as a heat-shrinkable label for a container, does not produce delamination in covering a container, is superior in heat resistance, oil resistance, tearing properties along the perforation and appearance and can prevent the reduction in strength between the layers after a printing step, and a heat-shrinkable label comprising the heat-shrinkable multilayer film as a base film. MEANS FOR SOLVING THE PROBLEMS [0007] The present invention is a heat-shrinkable multilayer film which comprises: an outer surface layer comprising a polyester type resin; and an intermediate layer comprising a polystyrene type resin, said outer surface layer and said intermediate layer being faminated by interposing an adhesive layer comprising a polyester type elastomer or a modified polyester type elastomer. Hereinafter, the present invention will be described in detail. [0008] The present inventors found that in the heat-shrinkable label comprising the heat-shrinkable multilayer film obtained by laminating outer surface layers comprising a polyester type resin on an intermediate layer comprising a polystyrene type resin with an adhesive layer interposed between the outer surface layer and the intermediate layer as a base film, the heat-shrinkable label can stably cover containers without producing the delamination by bonding the outer surface layers to the intermediate layer with an adhesive layer comprising a polyester type elastomer or a modified polyester type elastomer interposed therebetween. Further, the present inventors found that, in the case of using such a constitution, the reduction in strength between the layers after a printing step can be inhibited. These findings have now led to completion of the present invention. [0009] The heat-shrinkable multilayer film of the present invention is formed by laminating outer surface layers comprising a polyester type resin on an intermediate layer comprising a polystyrene type resin with an adhesive layer comprising a polyester type elastomer or a modified polyester type elastomer interposec between the outer surface layer and the intermediate layer. [0010] The polyester type elastomer is preferably a saturated polyester type elastomer, and particularly preferably a saturated polyester type elastomer containing polyalkylene ether glycol segments. As the saturated polyester type elastomer containing polyalkylene ether glycol segments, for example, block copolymers comprising an aromatic polyester as a hard segment and polyalkylene ether glycol or an aliphatic polyester as a soft segment are preferable. Furthermore, polyester polyether block copolymers containing polyalkylene ether glycol as a soft segment are more preferable. [0011] The polyester polyether block copolymer is preferably produced by polycondensation cf an oligomer obtained by esterification reaction or transesterification reaction between (i) aliphatic and/or alicyclic diol having 2 to 12 carbon atoms, (ii) an aromatic and/or aliphatic dicarboxylic acid or an alkyl ester thereof, and (iii) polyalkylene ether glycol as raw materials. [0012] As the aliphatic and/or alicyclic diol having 2 to 12 carbon atoms, for example, diols ordinarily used as raw materials for polyesters particularly raw materials for polyester type elastomers can be used. Specific examples of the aliphatic and/or alicyclic diol having 2 to 12 carbon atoms include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanoI, and the like. Among these diols, 1,4-butanediol and ethylene glycol are preferable, and 1,4-butanediol is particularly preferable. These diols may be used singly or in combination of two or more species. [0013] As the aromatic dicarboxylic acid, those ordinarily used as raw materials for polyesters, particularly raw materials for polyester type elastomers can be used. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2, 6-naphthalene dicarboxylic acid, and the like. Among these aromatic dicarboxylic acids, terephthalic acid and 2, 6-naphthalene dicarboxylic acid are preferable, and terephthalic acid is particularly preferable. These aromatic dicarboxylic acids may be used singly or in combination of two or more species. [0014] Examples of alkyl esters of the aromatic dicarboxylic acids include dimethyl esters or diethyl esters of the above aromatic dicarboxylic acids. Among there, dimethyl terephthalate and 2, 6-dimethylnaphthalene dicarboxylate are preferable. [0015] As the aliphatic dicarboxylic acid, cyclohexane dicarboxylic acids are pre ferable. As the alkyl ester thereof, dimethyl esters or diethyl esters of the cyclohexane dicarboxylic acids are preferable. In addition to the above components, a small amount of a trifunctional alcohol, a tricarboxylic acid or an ester thereof may be copolymerized therewith. Further, aliphatic dicarboxylic acids such as adipic acid or dialkyl esters thereof may also be used as a copolymer component. [0016] Examples of the polyalkylene ether glycol include polyethylene glycol, poly(1,2- and/or 1,3-propylene ether) glycol, poly (tetramethylene ether) glycol, poly(hexamethylene ether)glycol and the like. [0017] A preferable lower Limit of a number average molecular weight of the polyalkylene ether glycol is 400, and a preferable upper limit is 6000. When the number average molecular weight is 400 or more, a blockingproperty of the copolymer is enhanced, and when the number averac e molecular weight is 6000 or less, phase separation in a system becomes hard to occur and physical properties as a polymer becomes easy to be exibited. More preferably, the lower limit is 500, and the upper limit is 4000. Further more preferably, the lower limit is 600, and the upper limit is 3000. In addition, the number average molecular weight used herein refers to the value measured by gel permeation chromatography (GPC) . The calibration for GPC can be performed by use of, for example, "POLYTETRAHYDROFURAN CALIBRATION KIT" (manufactured by POLYMER LABORATORIES INC., GB.). [0018] Examples of the commercialized product of the polyester type elastomer include "PRIMALLOY" produced by Mitsubishi Chemical Corp., "PELPRENE" produced by Toyobo Co., Ltd., "Hytrel" produced by Du Pont-Toray Co., Ltd., and the like. [0019] When a polyester pclyether block copolymer comprising a polyester and polyalkylene ether glycol is used as the polyester type elastomer, a preferable lower limit of the content of the polyalkylene ether glycoL component is 5% by weight, and a preferable upper limit if 90% by weight. When the content of the polyalkylene ether glycol component is 5% by weight or more, the block copolymer becomes excellent in flexibility and impact resistance, and when the content is 90% by weight or less, the block copolymer becomes excellent in hardness and mechanical strength. More preferably, the lower limit is 30% by weight, and the upper limit is 80% by weight. Further more preferably, the lower limit is 55% by weight. In addition, the consent of the polyalkylene ether glycol component can be calculated from the chemical shift and content of hydrogen atoms using nuclear magnetic resonance (NMR) spectroscopy. [0020] The modified polyester type elastomer is obtained by modifying a polyester type elastomer with a modifying agent. A modification reaction for obtaining the modified polyester type elastomer is performed, for example, by reacting the polyester type elastomer with α,β-ethylenic unsaturated carboxylic acid as the modifying agent. In the modification reaction, a radical generator is preferably used. In the modification reaction, a graft reaction, in which the a, p-ethylenic unsaturated carboxylic acid or its derivative is added to the polyester type elastomer, mainly occurs, but a decomposition reaction also occurs. Consequently, a molecular weight of the modified polyester type elastomer is lowered and melt viscosity of the elastomer is lowered. Further, it is considered that in the modification reaction, generally, a transesterification reaction, and the like, also occur as other reactions, and the resulting products generally become compositions containing an unreacted raw material and the like, in this case, a lower limit of the content of the modified polyester type elastomer in the resulting product is preferably 10% by weight, and more preferably 30% by weight and the content of the modified polyester type elastomer is furthermore preferably 100% by weight. [0021] Examples of the α, β-ethylenic unsaturated carboxylic acid include unsaturated carboxylic acids such as acrylic acid, maleic acid, fumaric acid, tetrahydrofumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and the like; and unsaturated caiboxylic anhydrides such as 2-octene-l-yl-succinic anhydride, 2-dodecene-1-yl-succinic anhydride, 2-octadecene-1-yl-succinic anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, bromomaleic anhydride, dichloromaleic anhydride, citraconic anhydride, itaconic anhydride, 1-but ene-3,4-dicarboxylic anhydride, 1-cyclopentene-l,2-dicarkoxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, exo-3,6-epoxy-l,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, endo-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride and bicyclo [2.2.2] oct-7-ene-2,3,5, 6-tetracarboxylic anhydride. Among these, acid anhydride s are preferable since they have high reactivity. The α,β-ethylenic uisaturated carboxylic acids can be appropriately selected according to kinds of copolymers containing a polyalkylene ether glycol segment to be modified and modification conditions, and may be used in combination of two or more species. In addition, the α,β-ethylenic unsaturated carboxylic ands may be used in the form of a solution obtained by dissolving these compounds in an organic solvent, or the like. [0022] Examples of the radical generator include organic or inorganic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-bis(t-butyloxy)hexane, 3,5,5-trimethylhexanonyl peroxide, t-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, dibutyl peroxide, methyl ethyl ketone peroxide, potassium peroxide and hydrogen peroxide; azo compounds such as 2,2'-azobisisobutylonitrile, 2,2' -azobis (isobutylamide ) dihalide, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] and azo-di-t-butane; carbon radical generators such as dicumyl; and the like. The radical generator car. be appropriately selected according to kinds of the polyester type elastomer and kinds of the α,β-ethylenic unsaturated carboxylic acid, which are used for the modification reaction, and the modification conditions, and can be used in combination of two or more species . Furthermore, the radical generators can be used in the form of a solution obtained by dissolving these compounds in an organic solvent, or the like. [0023] A preferable lower Limit of the amount of the α,β-ethylenic unsaturated carboxylic acids to be mixed is 0.01 part by weight with respect to 100 parts by weight of the polyester type elastomer, and a preferable upper limit is 30.0 parts by weight. When the amount is 0.01 part by weight or more, the modification reaction c an be adequately performed, and when the amount is 30.0 parts by weight or less, the modified polyester type elastomez becomes economically advantageous. More preferably, the lower limit is 0.05 part by weight and the upper limit is 5.0 parts by weight, and furthermore preferably, the lower limit is 0.10 part by weight and the upper limit is 1.0 part by weight. [0024] A preferable lower limit of the amount of the radical generator to be mixed is 0.001 part by weight with respect to 100 parts by weight of the polyester type elastomer, and a preferable upper limit of the amount is 3.00 parts by weight. When the amount is 0. 001 part by weight or more, the modification reaction becomes apt to ocur, and when the amount is 3.00 parts by weight or less, the deterioration of material strength due to a reduction in molecular weight (reduction in viscosity) at the time of modification becomes hard to occur. More preferably, the lower limit is 0.005 part by weight and the upper limit is 0.50 part by weight, furthermore preferably, the lower limit is 0.010 part by weight and the upper limit is 0.20 part by weight, and particularly preferably, the upper limit is 0.10 part by weight. [0025] As the modification reaction for obtaining the modified polyester type elastomer, publicly known reaction methods such as a melt-kneading reaction method, a solution reaction method, a suspension-dispersion reaction method, and the like can be used, but the melt-kneading reaction method is generally preferable because of low cost. [0026] In the melt-kneading reaction method, the above-mentioned respective components are uniformly mixed together at predetermined blending ratios and then the resulting mixture is melt-kneaded. In order to mix the respective components, a Henschel mixer, a ribbon blender, a v-blender, or the like can oe used. In order to melt-knead the resulting mixture, a Banbary mixer, a kneader, a roll, a single-screw kneading extruder or a multi-screw kneading extruder such as twin-screw kneading extruder can be used [0027] A preferable lower limit of a kneading temperature at which the melt-kneading i s performed is 100°C, and a preferable upper limit is 300°C. By setting the kneading temperature at a temperature within this range, the heat deterioration of a resin can be prevented. More preferably, the lower limit is 120°C, and the upper limit is 280°C, and further more preferably, the lower limit is 150°C and the upper limit is 250°C. [0028] A rubber component such as natural rubber, synthetic rubber (for example, polylsoprene rubber), and the like and a softening agent such as process oil may coexist with the modified polyester type elastomer. By coexistence of the softening agent, plasticisation of the rubber component can be promoted and fluidity of the resulting thermoplastic resin composition can be improved. The softening agent may be any of paraffinic, naphthenic, and aromatic softening agents. Further, other components such as a resin, rubber, filler or additive other than those described above may be added to the resin components and rubber components within a range not impairing effects of the present invention. [0029] Examples of the filler include calcium carbonate, talc, silica, kaolin, clay, diatom earth, calcium silicate, mica, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, magnesium carbonate, carbon fiber, glass fiber, glass sphere, molybdenum sulfide, graphite, Shirasu-balloon, and the like. Further, Examples of the additives include heat-resistant stabilizers, weather-resistant stabilizers, colorants, antistatic agerts, flame retardants, nucleoators, lubricants, slip agents, anti-blocking agents, and the like. [0030] As the heat-resistant stabilizer, publicly known heat-resistant stabilizers such as phenole heat-resistant stabilizers, phosphoric heat-resistant stabilizers and sulfuric heat-resistant stabilizers can be used. As the weather-resistant stabilizer, publicly known weather-resistant stabilizers such as hindered amine weather-resistant stabilizers and triazole weather-resistant stabilizers can be used. Examples of the colorant include carbon black, titanium white, zinc white, red iron oxide, azo compounds, nitroso compounds, phthalocyanine compounds, and the like. Further, for all of the antistatic agents, the flame retardants, the nucleoaagents, the lubricants, the slip agents and the anti-blocking agents, publicly known substances can be used. [0031] A preferable lower limit of a modification ratio (grafting rate) of the modified polyester type elastomer is 0.01% by weight, and a preferable upper limit is 10.0% by weight. When the modification ratio is 0.01% by weight or more, affinity of the elastomer for a polyester becomes high, and when the modification ratio is 10.0% by weight or less, reduction in strength due to the deterioration of a molecule in modification can be reduced. More preferably, the lower limit is 0.03% by weight, and the upper limit is 7.3% by weight, and further more preferably, the lower limit is 0.05% by weight, and the upper limit is 5.0% by weight. [0032] The modification ratio (grafting rate) of the modified polyester type elastomer can be determined according to the following equation (1) from spectrums obtained by H1-NMR measurement. In additior , as equipment to be used for the H1-NMR measurement, for example, "GSX-400" (manufactured by JEOL Ltd.) can be used. [0033] Grafting rate (weight %) = 100 x (C/3 x 98) /{(Ax 148/4) + (B x 72/4) + (C/3 x 98) } (1) In the above equation (1), A is an integral value in an integral range of 7.8 to 3.4 ppm, B is an integral value in an integral range of 1.2 to 2.2 ppm, and C is an integral value in an integral range of 2.4 to 2.9 ppm. [0034] A preferable lower limit of a JIS-D hardness of a product containing the modified polyester type elastomer obtained by the modification reaction is 1C, and a preferable upper limit is 80. When the JIS-D hardness is 10 or more, mechanical strength is improved, and when the JIS-D hardness is 80 or less, flexibility and impact resistance are improved. More preferably, the lower Unit is 15, and the upper limit is 70, and further more pref erab] y, the lower limit is 20, and the upper limit is 60. In addition, the JIS-D hardness can be measured by using durometer type-D through a method according to JIS K6235. [0035] Examples of the polystyrene type resin composing the intermediate layer include an aromatic vinyl hydrocarbon-conjugated diene copolymer, a mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer, and the like. When the aromatic vinyl hydrocarbon-conjugated diene copolymer is used, the hea t-shrinkable multilayer film becomes a heat-shrinkable multilayer film which is hardly broken in an atmosphere of low temperature and has excellent handleability. Further, when the mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is used, the hee t-shrinkable multilayer film becomes a heat-shrinkable multilayer film having excellent low temperature shrinkability. [0036] The aromatic vinyl hydrocarbon-conjugated diene copolymer is not particularly limited, and examples of the aromatic vinyl hydrocarbon include styrene, o-methylstyrene, p-methylstyrene, and the like, and examples of the conjugated diene include 1,3-butadiene, 2-methyl-l,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. These dienes may be used singly or in combination of two or more species. Among these, a styrene-butadiene-styrere copolymer (SBS resin) is suitable since this copolymer is superior particularly in low temperature shrinkability and rearing properties along the perforation. Further, in order to prepare a film with less-fish eye, it is preferable to use a styrene-isoprene-styrene copolymer (SIS resin), a styrene-isoprene-butadiene-styrene copolymer (SIBS resin), and the like, in which 2-methyl-l, 3-butadiene (Isoprene) is used as conjugated diene . [0037] When the SBS resin, the SIS resin, or the SIBS resin is used as the aromatic vinyl hydrocarbon-conjugated diene copolymer, these resins may be used singly or in combination of two or more species. When these resins are used in combination of two or more species, resins may be dry-blended, or may be used as a compounded resin formed by kneading the resins in a specific composition with an extruder and pelletizing the extruded resin. When such resins are used singly or in combination of two or more species, the composition preferably has a styrene content of 65 to 90% by weight and a conjugated diene content of 10 to 35% by weight. Resins having such a composition are superior particularly in low temperature shrinkability and tearing properties along the perforation. On the other hand, when the conjugated diene content is less than 10% by weight, the film tends to tear when tension is applied, and the film may break contingently in converting printing or using the film as a label. When the conjugated diene content is more than 35% by weight, extraneous substances such as gel may become apt to be produced in molding processing the film. [0038] The aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is not particularly limited, examples of the aromatic, vinyl hydrocarbon include styrene, o-methylstyrene, p-methylstyrene, and the like, and examples of the unsaturated carboxylic acid ester include methylacrylate, ethylacrylate, propylacrylate, butylacrylate, methylmethacrylate, ethylmethacrylate, propylmethacrylate, butylmethacrylate, and the like. These copolymers may be used singly or in combination of two or more species. [0039] When a styrene-buzylacrylate copolymer is used as the aromatic vinyl hydrocaroon-aliphatic unsaturated carboxylic acid ester copolymer, substances having a styrene content of 60 to 90% by weight and a butylacrylate content of 10 to 40% by weight are preferably used. By using an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer having such composition, a heat-shrinkable label having excellent low temperature resistance and excellent tearing properties along the perforation can be attained. [0040] When a mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is used as the intermediate layer, a preferable lower limit of an amount of the aromatic vinyl hydrocarbon-conjugated diene copolymer to be mixed in the mixed resin is 20% by weight, and a preferable upper limit is 100% by weight. When the amount is less than 20% by weicrht, low temperature ductility becomes low and a heat-shrinkable label may be broken due to dropping it inadvertently during cold storage. The more preferable lower limit is 30% by weight. [0041] In the heat-shrinkable multilayer film of the present invention, the intermediate layer preferably contains an ultraviolet absorber. By thus containing the ultraviolet absorber, it is possible to provide ultraviolet light blocking properties, and it is possible tc prevent the deterioration of the contents of a container to enhance a storage property since particularly a property of blocking ultraviolet light (a wavelength 380 nm or shorter) emitted from solar light or a fluorescent lamp is excellent. Further, by containing the ultraviolet absorber in only the intermediate layer comprising a polystyrene type resin, problems such as heat deterioration and roll contamination in containing the ultraviolet absorber in the polyester type resin can be solved. Further, since a desired ultraviolet light blocking property can be achieved even when the content of the ultraviolet absorber is low, the heat-shrinkable multilayer film of the present invention becomes advantageous in the cost. [0042] The ultraviolet absorber is not particularly limited, and examples of the ultraviolet absorber include benzophenone type ultraviolet absorbers such as 2,4-dihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and 2-hydroxy-4-n-octoxybenzophenone; benzotriazole type ultraviolet absorbers such as 2-(2'-hydroxy-4'-n-octoxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-n-methoxyphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotria zole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, and 2-[2'-hydroxy-3'-(3'',4" ,5" , 6" -tetrahydrophthalimidemeth yl)-5'-methylphenyl]benzotriazole; benzoate type ultraviolet absorbers such as 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate; salicylate type ultraviolet absorbers such as p-t-butylphenylsalicylate; cyanoacrylate type ultraviolet absorber such as ethyl-2-cyano-3,3-diphenyl acrylate, and octyl-2-cyano-3,3-diphenyl acrylate; and the like. Among these, 2-(2'-hydroxy-5'-n-methoxyphenyl)benzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotria zole are preferable since they have excellent balance between ultraviolet light absorbancy and heat resistance. [0043] Apreferable lower limit of the content of the ultraviolet absorber, depending on the thickness of the intermediate layer, is 1 part by weight with respect to 100 parts by weight of materials, such as a base resin, and a recycle material, composing an intermediate- layer, and a preferable upper limit is 10 parts by weight. When the content is less than 1 part by weight, ultraviolet light blocking properties become inadequate and there may be cases where a resin film cannot prevent the deterioration of the contents of a container in using the resin film as a heat-shrinkable label of a container, and when the content is more than 10 parts by weight, mechanical strength of the heat-shrankable multilayer film is decreased and break of the film may occur in converting printing or using the resin film as a heat-shrinkable label. The more preferable lower limit of the content of the ultraviolet absorber is 2 parts by weight and the more preferable upper limit is 8 parts by weight. [0044] The polyester type resin composing the outer surface layers can be prepared by polycondensating dicarboxylic acid with diol. The dicarboxylic acid is not particularly limited, and examples of the dicarboxylic acid include o-phthalic acid, terephthalicacid, isophthalicacid, succinic acid, adipicacid, sebacic acid, azelaic acid, octylsuccinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, and decamethylenecarboxylic icid, and anhydrides and lower alkyl esters thereof. The diol is not particularly limited, and examples of the diol include aliphatic dlols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-buta lediol, neopentyl glycol(2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, and 2-ethyl-1,3-hexanediol; alicyclic diols such as 2,2-bis(4-hydroxycyclohexyl)propane, alkylene oxide addition product of 2,2-bis(4-hydroxycyclohe