[Citation with related applications] [2] This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0037549 dated March 30, 2018 and Korean Patent Application No. 10-2018-0117839 dated October 02, 2018, All content disclosed in the literature is incorporated as a part of this specification. [3] [Technical field] [4] The present invention relates to a block copolymer composition, and more particularly, to a block copolymer composition including a diblock copolymer and a triblock copolymer including a polyolefin-based block and a polystyrene-based block. background [5] Polyolefin-polystyrene block copolymers, such as styrene-ethylene/butylene-styrene (SEBS) or styrene-ethylene/propylene-styrene (SEPS), currently have a global market of hundreds of thousands of tons. In addition, they have superior heat resistance and light resistance compared to Styrene-butadiene-styrene (SBS) or styrene-isoprene-styrene (SIS). It is used as an oil-gel used in communication materials, an impact modifier for engineering plastics, and a plasticizer or toughener for transparent polypropylene. Conventional SEBS is prepared through a two-step reaction of hydrogenating SBS obtained by anionic polymerization of styrene and butadiene. Conventional SEPS is also prepared through a two-step reaction in which SIS obtained by anionic polymerization of styrene and isoprene is hydrogenated. The process of saturating all of the unsaturated bonds included in the polymer main chain by hydrogenation has a high process cost, so the unit price of SEBS and SEPS is significantly higher than that of SBS and SIS before hydrogenation. This may act as a limit to market expansion. In addition, since it is virtually impossible to saturate all unsaturated bonds in the polymer chain through hydrogenation reaction, commercialized SEBS and SEPS contain some residual unsaturated bonds, and their presence is often problematic (Journal of Polymer Science: Part A: Polymer Chemistry, 2002, 40, 1253; Polymer Degradation and Stability 2010, 95, 975). In addition, the conventional block copolymer prepared through two steps as described above has a very limited structure because the polyolefin block is formed through hydrogenation reaction after anionic polymerization of butadiene or isoprene. DETAILED DESCRIPTION OF THE INVENTION technical challenge [6] An object of the present invention is to provide a block copolymer composition including a diblock copolymer and a triblock copolymer including a polyolefin-based block and a polystyrene-based block, having improved heat resistance. means of solving the problem [7] In order to solve the above problems, the present invention provides a block copolymer composition comprising a diblock copolymer and a triblock copolymer comprising a polyolefin-based block and a polystyrene-based block, and 45 to 90% by weight of a polyolefin-based block, and 10 wt % to 55 wt % of a polystyrene-based block, wherein the difference (ΔT) between the thermal decomposition initiation temperature and the thermal decomposition end temperature measured by Thermo-Gravimetric Analysis (TGA) is 55° C. or more, It provides a block copolymer composition, characterized in that there is no residual unsaturated bonds in the triblock copolymer and the diblock copolymer. Effects of the Invention [8] The block copolymer composition according to the present invention is a block copolymer composition including a diblock copolymer and a triblock copolymer including a polyolefin-based block and a polystyrene-based block, and does not contain an unsaturated bond in the molecular structure of the block copolymer. Excellent heat resistance can be exhibited. Best mode for carrying out the invention [9] Hereinafter, the present invention will be described in more detail to help the understanding of the present invention. [10] The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention. [11] As used herein, the term 'composition' includes reaction products and decomposition products formed from materials of the composition, as well as mixtures of materials comprising the composition. [12] As used herein, the term 'residual unsaturated bonds' refers to unsaturated bonds such as double bonds and triple bonds present in the polymer chain of the block copolymer included in the block copolymer composition, and the polymer chain is the block copolymer. contains the main chain and branched chain of the block copolymer, including unsaturated bonds generated during polymerization as well as unsaturated bonds contained in or derived from raw materials such as monomers, multimers, initiators, catalysts, etc. used to prepare the block copolymer do. [13] As used herein, the term 'halogen' means fluorine, chlorine, bromine or iodine, unless otherwise noted. [14] As used herein, the term 'alkyl' refers to a straight-chain, cyclic or branched hydrocarbon moiety, unless otherwise indicated. [15] The term 'aryl' as used herein, unless otherwise specified, refers to an aromatic group including phenyl, naphthyl anthryl, phenanthryl, chrysenyl, pyrenyl, and the like. [16] In the present specification, silyl may be silyl unsubstituted or substituted with alkyl having 1 to 20 carbon atoms, for example, silyl, trimethylsilyl or triethylsilyl. [17] [18] The block copolymer composition of the present invention is a block copolymer composition including a diblock copolymer and a triblock copolymer including a polyolefin-based block and a polystyrene-based block, and 45 to 90% by weight of a polyolefin-based block, and 10 a polystyrene-based block of from weight % to 55 weight %, wherein the difference (ΔT) between the thermal decomposition initiation temperature and the thermal decomposition end temperature measured by Thermo-Gravimetric Analysis (TGA) is 55° C. or more, wherein Since residual unsaturated bonds do not exist in the triblock copolymer and the diblock copolymer, improved heat resistance can be exhibited. [19] In the block copolymer composition of the present invention, when the temperature at which thermal decomposition starts and the temperature at which thermal decomposition ends is measured using TGA (Thermo-Gravimetric Analysis), the temperature at which the thermal decomposition ends and the thermal decomposition are The difference in temperature (ΔT) that starts to occur may have a large value of 55°C or more, specifically 55°C to 70°C, and more specifically 57°C to 65°C. The block copolymer composition of the present invention has no residual unsaturated bonds in the block copolymer, and contains 45 wt% to 90 wt% of a polyolefin-based block, and 10 wt% to 55 wt% of a polystyrene-based block. Heat resistance can be exhibited. When the difference (ΔT) between the temperature at which the thermal decomposition ends and the temperature at which the thermal decomposition begins to satisfy the above range, the block copolymer composition may exhibit improved heat resistance and excellent processability. [20] When the temperature at which thermal decomposition starts and the temperature at which thermal decomposition ends is measured using TGA (Thermo-Gravimetric Analysis) for the block copolymer composition, the temperature at which thermal decomposition ends is 440° C. to 470° C. ℃, the temperature at which the thermal decomposition starts may be 385 °C to 405 °C, specifically, the temperature at which the thermal decomposition ends is 445 °C to 465 °C, and the temperature at which the thermal decomposition starts is 388 °C to 405 °C, more specifically, the temperature at which the thermal decomposition ends is 448 °C to 463 °C, and the temperature at which the thermal decomposition starts may be 390 °C to 403 °C. [21] The block copolymer composition according to an example of the present invention may also satisfy (1) a weight average molecular weight (Mw) of 70,000 g/mol to 120,000 g/mol, specifically 72,000 g/mol to 110,000 g/mol, more Specifically, 74,000 g/mol to 103,000 g/mol may be satisfied. In the present invention, the weight average molecular weight (Mw) is a polystyrene equivalent molecular weight analyzed by gel permeation chromatography (GPC). [22] In addition, the block copolymer composition may have (2) a polydispersity index (PDI) of 1.0 to 2.0, specifically 1.2 to 1.8, and more specifically 1.4 to 1.7. In the present invention, the polydispersity index refers to a ratio of Mw/Mn, Mw is a weight average molecular weight, and Mn is a number average molecular weight. [23] In addition, the block copolymer composition may have (3) a glass transition temperature (Tg) of -55 ℃ to -30 ℃, specifically -55 ℃ to -39 ℃, more specifically -52 ℃ to -39 ℃ can be satisfied The glass transition temperature (Tg) may be measured using a dynamic mechanical analyzer (DMA). [24] In addition, the block copolymer composition (4) melt index (MI, 230 ℃, 5 kg load conditions) may satisfy 0.2 to 3.0 g / 10 min, specifically 0.3 to 2.5 g / 10 min, more specifically 0.3 to 2.1 g/10 min may be satisfied. [25] The melt index (MI) affects the mechanical properties, impact strength, and moldability of the block copolymer. In the present specification, the melt index may be measured at 230° C. and a load of 5 kg according to ASTM D1238 (ISO 1133). [26] When the block copolymer composition of the present invention satisfies the conditions (1) to (4) at the same time, it exhibits a high molecular weight and a wide molecular weight distribution, and thus can exhibit excellent processability as well as improved heat resistance as described above. [27] [28] The block copolymer composition of the present invention may include, for example, (a) reacting an organic zinc compound with at least one olefinic monomer under a transition metal catalyst to form an olefinic polymer block to prepare an intermediate; and (b) reacting the intermediate obtained in step (a) with a styrenic monomer in the presence of an alkyllithium compound to form a styrenic polymer block. [29] [30] (a) reacting an organic zinc compound with at least one olefinic monomer under a transition metal catalyst to form an olefinic polymer block to prepare an intermediate [31] [32] In step (a), the olefinic monomer may be inserted between Zn and A of the organic zinc compound to be polymerized to form an olefinic polymer block. [33] In an example of the present invention, the olefin-based polymer block formed by polymerization of one or more olefin-based monomers may include a repeating unit represented by the following formula (1), and in the present specification, a repeating unit represented by the following formula (1) The olefinic polymer block containing is represented as a first block. [34] In step (a), the olefinic monomer may form a first block including at least one repeating unit represented by the following Chemical Formula 1. [35] [Formula 1] [36] [37] In Formula 1, [38] R 1 is hydrogen; alkyl having 1 to 20 carbon atoms; alkyl having 1 to 20 carbon atoms substituted with silyl; arylalkyl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms substituted with silyl; [39] n may be an integer from 1 to 10,000. [40] In addition, in an example of the present invention, R 1 is hydrogen; It may be an alkyl having 3 to 20 carbon atoms. [41] In addition, in an example of the present invention, R 1 is hydrogen; Alternatively, it may be an alkyl having 3 to 12 carbon atoms, and specifically, R 1 may be hydrogen or an alkyl having 4 to 12 carbon atoms. [42] In addition, n may be an integer of 10 to 10,000, specifically, may be an integer of 500 to 7,000. [43] On the other hand, in the formulas shown in the specification of the present invention, "*" represents a linking site as a terminal site of the repeating unit. [44] [45] In an example of the present invention, when the first block includes two or more types of repeating units represented by Chemical Formula 1, the first block may include repeating units represented by Chemical Formula 2 below. [46] [Formula 2] [47] [48] In Formula 2, [49] R 1 ′ and R 1 ″ are each independently hydrogen, alkyl having 1 to 20 carbon atoms ; alkyl having 1 to 20 carbon atoms substituted with silyl; arylalkyl having 7 to 20 carbon atoms; or aryl having 7 to 20 carbon atoms substituted with silyl. alkyl; wherein R 1 ' and R 1 "are different from each other, [50] 0