Block copolymer hyrdrogenation product, resin composition, and molded body

Abstract

One purpose of the present invention is to provide a block copolymer hydrogenation product with which it is possible to form a molded body that has superior flatness as well as having reduced molding defects, surface nonuniformity, and autoflorescence. A block copolymer hydrogenation product according to the present invention is a block copolymer hydrogenation product [D] that has a weight average molecular weight within a prescribed range, and is obtained by hydrogenating a block copolymer [C] that comprises two or more polymer blocks [A] having a constituent unit derived from an aromatic vinyl compound as a main component, and one or more polymer blocks [B] having a constituent unit derived from a linear conjugated diene compound as a main component. In the block copolymer [C], the ratio of the mass fraction of the constituent unit or units derived from an aromatic vinyl compound and the mass fraction of the constituent unit or units derived from a linear conjugated diene compound is within a prescribed range, and included are a polymer block [A1] in which the mass fraction of the constituent unit derived from an aromatic vinyl compound is within a prescribed range, and a polymer block [A2] in which the mass fraction of the constituent unit derived from an aromatic vinyl compound is within a prescribed range.

Description

Hydride of Block Copolymer, Resin Composition, and Molded Article

[0001] The present invention relates to a hydride of block copolymer, a resin composition, and a molded article.

[0002] Conventionally, for producing packaging for pharmaceuticals and foods, sealing materials for solar cell modules, sealing materials for organic EL elements, sealing materials for electronic components, interlayer films for laminated glass, and the like, hydrogenation reaction is performed on a block copolymer having a polymer block mainly composed of a structural unit derived from an aromatic vinyl compound and a polymer block mainly composed of a structural unit derived from a linear conjugated diene compound, to obtain a polymer (hydride of block copolymer) that is used for these applications.

[0003] Such a hydride of block copolymer is generally used for the aforementioned applications by mixing it with other components and molding the resulting resin composition into a molded article having a desired shape.

[0004] For example, Patent Document 1 discloses a hydride of block copolymer [D] obtained by hydrogenating a block copolymer [C] composed of two polymer blocks [A] mainly composed of a structural unit derived from an aromatic vinyl compound, and one polymer block [B] mainly composed of a structural unit derived from a linear conjugated diene compound, wherein among the two polymer blocks [A], when the block with a lower molecular weight is defined as polymer block [A1] and the block with a higher molecular weight is defined as polymer block [A2], the molecular weights of the polymer block [A1] and the polymer block [A2] fall within specific ranges. According to Patent Document 1, when the hydride of block copolymer is used, a resin molded article that has excellent heat resistance and mechanical strength, and exhibits less sink marks can be obtained by a melt molding method.

[0005] Japanese Patent Laid-Open No. 2018-16738

[0006] In recent years, in fields such as cell biology, cells are cultured in molded bodies such as microplates and dishes obtained by molding resin compositions, and the cultured cells are observed using fluorescence. In fluorescence observation, autofluorescence emitted from the molded body interferes with the detection of cell-derived fluorescence signals for imaging, so there is a need to reduce the autofluorescence emitted from the molded body. However, the conventional resin compositions described above had room for further improvement in terms of reducing the autofluorescence of the resulting molded bodies. In addition, when molded bodies were formed using the conventional resin compositions described above, molding defects such as cracks and chips occurred, or the gloss of the molded body surface appeared dull (i.e., surface unevenness occurred). Furthermore, the conventional resin compositions described above had room for further improvement in terms of improving the flatness of the resulting molded bodies.

[0007] Therefore, the present invention aims to provide block copolymer hydrides and resin compositions capable of forming molded articles with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence.

[0008] The inventors diligently conducted research with the aim of solving the above problems. The inventors have found a block copolymer hydride [D] obtained by hydrogenating a block copolymer [C] consisting of at least two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds and at least one polymer block [B] mainly composed of structural units derived from chain-like conjugated diene compounds, wherein the ratio (wA / wB) of the mass fraction (wA) of structural units derived from all aromatic vinyl compounds in the entire block copolymer [C] to the mass fraction (wB) of structural units derived from all chain-like conjugated diene compounds in the entire block copolymer [C] is within a predetermined range, and polymer block [A] is polymer block [A1] The present invention was completed by using a block copolymer hydride [D] which includes polymer block [A1] and polymer block [A2] with a lower mass fraction than polymer block [A1], wherein the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] to the entire block copolymer [C] is within a predetermined range, the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] to the entire block copolymer [C] is within a predetermined range, and the weight-average molecular weight is within a predetermined range. This allows for the creation of a molded article with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence.

[0009] In other words, the present invention aims to advantageously solve the above problems, and according to the present invention, the following block copolymer hydrides [1] to [2], the following resin composition [3], and the following molded articles [4] to [7] are provided.

[0010] [1] A block copolymer hydride [D] obtained by hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains and the carbon-carbon unsaturated bonds of the aromatic ring of a block copolymer [C] comprising at least two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds and at least one polymer block [B] mainly composed of structural units derived from chain-like conjugated diene compounds, wherein when wA is the mass fraction of structural units derived from all aromatic vinyl compounds in the entire block copolymer [C] and wB is the mass fraction of structural units derived from all chain-like conjugated diene compounds in the entire block copolymer [C], the ratio of wA to wB (wA / wB) is 65 / 35 or more and 90 / 10 or less, and the at least two polymer blocks [A] are A block copolymer hydride comprising polymer block [A1] and polymer block [A2], wherein the mass fraction of polymer block [A2] in the block copolymer [C] is lower than the mass fraction of polymer block [A1] in the block copolymer [C], the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] in the entire block copolymer [C] is 50% by mass or more and 75% by mass or less, the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] in the entire block copolymer [C] is 15% by mass or more and 30% by mass or less, and the weight-average molecular weight of the block copolymer hydride [D] is greater than 65,000 and 120,000 or less. In this invention, "primarily composed of structural units derived from aromatic vinyl compounds" means "containing more than 50% by mass of structural units derived from aromatic vinyl compounds," and "primarily composed of structural units derived from chain-like conjugated diene compounds" means "containing more than 50% by mass of structural units derived from chain-like conjugated diene compounds." Furthermore, in this invention, "obtained by hydrogenating a block copolymer [C]" means that 95% or more of the carbon-carbon unsaturated bonds in the main chain and side chains of the block copolymer [C] and the carbon-carbon unsaturated bonds in the aromatic ring are hydrogenated, that is, the hydrogenation rate of the block copolymer hydride [D] is 95% or more. In this invention, the "hydrogenation rate" of the block copolymer [D] can be measured using the method described in the examples of this specification.Furthermore, in the present invention, the "weight-average molecular weight" of the block copolymer hydride [D] can be measured using the method described in the examples of this specification. In addition, in the present invention, "wA / wB", "wA1", and "wA2" are defined as follows. １ H-NMR and １３ It can be measured using nuclear magnetic resonance (NMR) methods such as C-NMR.

[0011] [2] The block copolymer hydride according to [1] above, wherein the block copolymer hydride [D] has a triblock structure consisting of two polymer blocks formed by hydrogenating polymer block [A] and one polymer block formed by hydrogenating polymer block [B], or a pentablock structure consisting of three polymer blocks formed by hydrogenating polymer block [A] and two polymer blocks formed by hydrogenating polymer block [B].

[0012] [3] A resin composition comprising the block copolymer hydride described in [1] or [2] above.

[0013] [4] A molded article wherein at least a portion of the molded article is formed by molding the resin composition described in [3] above.

[0014] [5] The molded body described in [4] above, which is an experimental apparatus.

[0015] [6] A molded body as described in [4] or [5] above, which is a microplate.

[0016] [7] A molded body according to any of [4] to [6] above, used for fluorescence observation.

[0017] Furthermore, the block copolymer hydride of the present invention is a block copolymer [D] obtained by hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains and the carbon-carbon unsaturated bonds of the aromatic ring of a block copolymer [C] consisting of two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds and one polymer block [B] mainly composed of structural units derived from chain-like conjugated diene compounds, wherein when wA is the mass fraction of structural units derived from all aromatic vinyl compounds in the entire block copolymer [C] and wB is the mass fraction of structural units derived from all chain-like conjugated diene compounds in the entire block copolymer [C], the ratio of wA to wB (wA / wB) is 75 / 25 or more and 85 / 15 or less, and the two polymer blocks [A] are polymer Preferably, the block copolymer hydride comprises block [A1] and polymer block [A2], wherein the mass fraction of polymer block [A2] in the block copolymer [C] is lower than the mass fraction of polymer block [A1] in the block copolymer [C], the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] in the entire block copolymer [C] is 50% by mass or more and 75% by mass or less, the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] in the entire block copolymer [C] is 15% by mass or more and 30% by mass or less, and the weight-average molecular weight of the block copolymer hydride [D] is more than 65,000 and 120,000 or less.

[0018] According to the present invention, it is possible to provide block copolymer hydrides and resin compositions that can form molded articles with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence. Furthermore, according to the present invention, it is possible to provide molded articles with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence.

[0019] Embodiments of the present invention will be described in detail below. The block copolymer hydride of the present invention can be used in the preparation of the resin composition of the present invention. The resin composition of the present invention can be used in various fields as a resin material constituting various molded articles. Furthermore, the molded article of the present invention is formed by molding at least a part of the resin composition of the present invention, and is preferably an experimental apparatus such as a microplate. Note that each component disclosed herein, as well as the preferred embodiments, numerical ranges, and thresholds defining such numerical ranges shown with respect to each component, can be independently combined with each other in any manner.

[0020] (Block copolymer hydride [D]) The block copolymer hydride [D] of the present invention has the following characteristics (1) to (5). (1) The block copolymer hydride [D] is obtained by hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains and the carbon-carbon unsaturated bonds of the aromatic ring of a block copolymer [C] which consists of at least two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds and at least one polymer block [B] mainly composed of structural units derived from chain-like conjugated diene compounds. (2) The ratio (wA / wB) of the mass fraction (wA) of structural units derived from all aromatic vinyl compounds in the block copolymer [C] to the mass fraction (wB) of structural units derived from all chain-like conjugated diene compounds in the block copolymer [C] is 65 / 35 or more and 90 / 10 or less. (3) At least two polymer blocks [A] contained in the block copolymer [C] include polymer block [A1] and polymer block [A2], and the mass fraction of polymer block [A2] in the block copolymer [C] is lower than the mass fraction of polymer block [A1] in the block copolymer [C]. (4) The mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] in the entire block copolymer [C] is 50% by mass or more and 75% by mass or less, and the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] in the entire block copolymer [C] is 15% by mass or more and 30% by mass or less. (5) The weight-average molecular weight of the block copolymer hydride [D] is greater than 65,000 and 120,000 or less. Furthermore, because the block copolymer hydride [D] of the present invention has the above characteristics (1) to (5), it is possible to form a molded article that has excellent flatness and reduced molding defects, surface unevenness, and autofluorescence.

[0021] <Block Copolymer [C]> The block copolymer [C] is a precursor of the block copolymer hydride [D] of the present invention, and consists of at least two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds, and at least one polymer block [B] mainly composed of structural units derived from chain-like conjugated diene compounds.

[0022] Furthermore, block copolymer [C] does not contain polymer blocks other than polymer block [A], which is mainly composed of structural units derived from aromatic vinyl compounds, and polymer block [B], which is mainly composed of structural units derived from chain-like conjugated diene compounds. In other words, block copolymer [C] does not contain polymer blocks that are mainly composed of structural units derived from compounds other than aromatic vinyl compounds and chain-like conjugated diene compounds.

[0023] Here, the number of polymer blocks [A] in the block copolymer [C] must be two or more. Furthermore, from the viewpoint of controlling physical properties, the number of polymer blocks [A] in the block copolymer [C] is usually five or less, preferably four or less, more preferably three or less, and even more preferably two. Also, the number of polymer blocks [B] in the block copolymer [C] must be one or more. Furthermore, from the viewpoint of controlling physical properties, the number of polymer blocks [B] in the block copolymer [C] is usually four or less, preferably three or less, more preferably two or less, and even more preferably one.

[0024] <<Polymer Block [A]>> Polymer block [A] is a polymer block whose main component is a structural unit derived from an aromatic vinyl compound. The structural units derived from aromatic vinyl compounds in at least two polymer blocks [A] contained in block copolymer [C] may be the same or different from each other, but it is preferable that they be the same. For example, the structural units derived from aromatic vinyl compounds in polymer block [A1] and the structural units derived from aromatic vinyl compounds in polymer block [A2] may be the same or different from each other, but it is preferable that they be the same. In addition, each polymer block [A] (for example, polymer block [A1]) may contain only one type of structural unit derived from an aromatic vinyl compound, or it may contain multiple types of structural units derived from an aromatic vinyl compound, but it is preferable that it contains only one type of structural unit derived from an aromatic vinyl compound.

[0025] Here, at least two polymer blocks [A] contained in the block copolymer [C] include polymer block [A1] and polymer block [A2] whose mass fraction in the block copolymer [C] is lower than that of polymer block [A1].

[0026] —Polymer Block [A1]— The content of structural units derived from aromatic vinyl compounds in polymer block [A1] is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass, with the total repeating units in polymer block [A1] being 100% by mass. If the content of structural units derived from aromatic vinyl compounds in polymer block [A1] is above the above lower limit, the dimensional stability of the molded article can be improved.

[0027] The polymer block [A1] may contain structural units other than those derived from aromatic vinyl compounds (other structural units 1). Examples of other structural units 1 include structural units derived from chain-like conjugated diene compounds and / or other vinyl compounds. The content of other structural units 1 in the polymer block [A1] is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, with the total repeating units in the polymer block [A1] being 100% by mass. If the content of other structural units 1 in the polymer block [A1] is below the above upper limit, the dimensional stability of the molded article can be improved.

[0028] —Polymer Block [A2]— The content of structural units derived from aromatic vinyl compounds in polymer block [A2] is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass, with the total repeating units in polymer block [A2] being 100% by mass. If the content of structural units derived from aromatic vinyl compounds in polymer block [A2] is above the above lower limit, the dimensional stability of the molded article can be improved.

[0029] The polymer block [A2] may contain structural units other than those derived from aromatic vinyl compounds (other structural units 2). Examples of other structural units 2 include structural units derived from chain-like conjugated diene compounds and / or other vinyl compounds. The content of other structural units 2 in the polymer block [A2] is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, with the total repeating units in the polymer block [A2] being 100% by mass. If the content of other structural units 2 in the polymer block [A2] is below the above upper limit, the dimensional stability of the molded article can be improved.

[0030] Furthermore, the block copolymer [C] may contain polymer blocks [A] other than polymer block [A1] and polymer block [A2]. Examples of such polymer blocks [A] include polymer blocks whose main component is structural units derived from aromatic vinyl compounds, and in which the mass fraction of structural units derived from aromatic vinyl compounds in the polymer block does not satisfy either of the above-mentioned conditions wA1 and wA2. In addition, the types and proportions of structural units other than those derived from aromatic vinyl compounds in polymer blocks [A] other than polymer block [A1] and polymer block [A2] may be the same as the types and proportions of structural units other than those derived from aromatic vinyl compounds in polymer blocks A1 and A2.

[0031] <<Polymer Block [B]>> Polymer block [B] is a polymer block whose main component is a structural unit derived from a chain-like conjugated diene compound. When a block-conjugated polymer [C] has two or more polymer blocks [B], the structural units derived from the chain-like conjugated diene compound in the two or more polymer blocks [B] may be the same or different from each other, but it is preferable that they be the same. For example, when a block-conjugated polymer [C] has two polymer blocks [B], namely polymer block [B1] and polymer block [B2], the structural units derived from the chain-like conjugated diene compound in polymer block [B1] and the structural units derived from the chain-like conjugated diene compound in polymer block [B2] may be the same or different from each other, but it is preferable that they be the same. Furthermore, each polymer block [B] (for example, polymer block [B1]) may contain only one structural unit derived from a chain-like conjugated diene compound, or it may contain multiple structural units derived from a chain-like conjugated diene compound, but it is preferable that it contains only one structural unit derived from a chain-like conjugated diene compound.

[0032] The content of structural units derived from the chain-like conjugated diene compound in polymer block [B] is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass, with the total repeating units in polymer block [B] being 100% by mass. If the content of structural units derived from the chain-like conjugated diene compound in polymer block [B] is above the above lower limit, the flexibility of the block copolymer hydride [D] is well ensured. Therefore, molding defects can be further reduced.

[0033] The polymer block [B] may contain structural units other than those derived from the chain-like conjugated diene compound (other structural units 3). Examples of other structural units 3 include structural units derived from aromatic vinyl compounds and / or other vinyl compounds. The content of other structural units 3 in polymer block [B] is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, with the total repeating units in polymer block [B] being 100% by mass. If the content of structural units derived from the chain-like conjugated diene compound in polymer block [B] is below the above upper limit, the flexibility of the block copolymer hydride [D] is well ensured. Therefore, molding defects can be further reduced.

[0034] [Aromatic Vinyl Compounds] Examples of aromatic vinyl compounds include styrene; styrenes having C1-C6 alkyl groups as substituents, such as α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, and 5-t-butyl-2-methylstyrene; styrenes having halogen atoms as substituents, such as 4-chlorostyrene, dichlorostyrene, and 4-monofluorostyrene; styrenes having C1-C6 alkoxy groups as substituents, such as 4-methoxystyrene; styrenes having aryl groups as substituents, such as 4-phenylstyrene; vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene; and the like. Among these, aromatic vinyl compounds that do not contain polar groups, such as styrene and styrenes having C1-C6 alkyl groups as substituents, are preferred from the viewpoint of hygroscopicity, and styrene is particularly preferred due to its ease of industrial availability.

[0035] [Chain-Conjugated Diene Compounds] Examples of chain-conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 2-chloro-1,3-butadiene. Among these, chain-conjugated diene compounds that do not contain polar groups are preferred from the viewpoint of low hygroscopicity, and 1,3-butadiene and isoprene are particularly preferred due to their ease of industrial availability.

[0036] [Other Vinyl Compounds] Other vinyl compounds include chain olefin compounds, cyclic olefin compounds, unsaturated cyclic acid anhydrides, and unsaturated imide compounds. These compounds may have nitrile groups, alkoxycarbonyl groups, hydroxycarbonyl groups, or halogen atoms as substituents. Among these, from the viewpoint of hygroscopicity, those that do not contain polar groups are preferred, such as chain olefin compounds having 2 to 20 carbon atoms, including ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, 4-methyl-1-pentene, and 4,6-dimethyl-1-heptene; and cyclic olefin compounds having 5 to 20 carbon atoms, including vinylcyclohexane, 4-vinylcyclohexene, and norbornene; chain olefin compounds having 2 to 20 carbon atoms are more preferred, and ethylene and propylene are particularly preferred.

[0037] <<Characteristics of Block Copolymer [C]>> [wA / wB] When wA is the mass fraction of structural units derived from all aromatic vinyl compounds in the block copolymer [C], and wB is the mass fraction of structural units derived from all chain conjugated diene compounds in the block copolymer [C], the ratio of wA to wB (wA / wB) must be 65 / 35 or more and 90 / 10 or less. If wA / wB is less than 65 / 35, the dimensional stability of the molded article decreases. On the other hand, if wA / wB is greater than 90 / 10, the flexibility of the block copolymer hydride [D] decreases, and molding defects increase. Preferably, the ratio of wA to wB (wA / wB) is 75 / 25 or more, and preferably 85 / 15 or less. If wA / wB is 75 / 25 or more, the dimensional stability of the molded article can be improved. On the other hand, if wA / wB is 85 / 15 or less, the flexibility of the block copolymer hydride [D] is well ensured. Therefore, molding defects can be further reduced.

[0038] [wA1] The mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] to the entire block copolymer [C] must be 50% by mass or more and 75% by mass or less. If wA1 is less than 50% by mass, the flexibility of the block copolymer hydride [D] decreases, and molding defects increase. On the other hand, if wA1 is greater than 75% by mass, the fluidity of the resin composition when melted decreases, making it difficult to process. As a result, the flatness of the resulting molded article decreases. Furthermore, the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] to the entire block copolymer [C] is preferably 55% by mass or more, and preferably 65% ​​by mass or less. If wA1 is 55% by mass or more, the flexibility of the block copolymer hydride [D] is well ensured. As a result, molding defects can be further reduced. On the other hand, if wA1 is 65% by mass or less, the fluidity of the resin composition when melted is sufficiently ensured, and the flatness of the molded article can be further improved.

[0039] [wA2] The mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] to the entire block copolymer [C] must be 15% by mass or more and 30% by mass or less. If wA2 is less than 15% by mass, surface irregularities of the resulting molded article increase. On the other hand, if wA2 is greater than 30% by mass, the flexibility of the block copolymer hydride [D] decreases, and molding defects increase. Preferably, the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] to the entire block copolymer [C] is 17.5% by mass or more, and preferably 25% by mass or less. If wA2 is 17.5% by mass or more, surface irregularities of the resulting molded article can be further reduced. On the other hand, if wA2 is 25% by mass or less, the flexibility of the block copolymer hydride [D] is well ensured. Therefore, molding defects can be further reduced.

[0040] [wA1 / wA2] The ratio (wA1 / wA2) of the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] to the total mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] to the total mass fraction (wA2) of block copolymer [C] is preferably 1.7 or more, more preferably 2.0 or more, even more preferably 2.5 or more, preferably 4.8 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. If wA1 / wA2 is above the lower limit, the flexibility of the block copolymer hydride [D] is well ensured. Therefore, molding defects can be further reduced. On the other hand, if wA1 / wA2 is below the upper limit, surface irregularities of the resulting molded article can be further reduced.

[0041] [Weight-average molecular weight] The weight-average molecular weight (Mw) of the block copolymer [C] is preferably 80,000 or more, more preferably 100,000 or more, preferably 210,000 or less, and more preferably 190,000 or less.

[0042] [Molecular Weight Distribution] The molecular weight distribution (Mw / Mn) of the block copolymer [C] is preferably more than 1.0, more preferably 1.05 or more, still more preferably 1.3 or less, and even more preferably 1.2 or less. In the present invention, the weight average molecular weight and molecular weight distribution of the block copolymer [C] can be measured using the method described in the Examples of the present specification.

[0043] [Block Structure] Particularly preferred embodiments of the block copolymer [C] include a triblock copolymer (A-B-A) formed by bonding polymer blocks [A] to both ends of a polymer block [B], and a pentablock copolymer (A-B-A-B-A) formed by bonding polymer blocks [B] to both ends of a polymer block [A], and further bonding a polymer block [A] to the other end of each of the two polymer blocks [B].

[0044] <Characteristics of Hydrogenated Block Copolymer [D]> <<Hydrogenation Rate>> The hydrogenated block copolymer [D] of the present invention is obtained by hydrogenating carbon-carbon unsaturated bonds in the main chain and side chains of the block copolymer [C], as well as carbon-carbon unsaturated bonds in aromatic rings. Here, the hydrogenation rate of the hydrogenated block copolymer [D] is required to be 95.0% or more. If the hydrogenation rate of the hydrogenated block copolymer [D] is less than 95.0%, the autofluorescence of the resulting molded article will increase. The hydrogenation rate of the hydrogenated block copolymer [D] is preferably 97.2% or more, more preferably 99.0% or more, and still more preferably 99.5% or more. When the hydrogenation rate of the hydrogenated block copolymer [D] is not less than the above lower limit, the autofluorescence of the resulting molded article can be further reduced. The upper limit of the hydrogenation rate of the hydrogenated block copolymer [D] is not particularly limited, and for example, can be 100% or less, or 99.9% or less. The hydrogenation rate of the hydrogenated block copolymer [D] can be adjusted, for example, by changing the conditions for the hydrogenation reaction of the block copolymer [C].

[0045] <<Weight Average Molecular Weight>> The weight average molecular weight (Mw) of the hydrogenated block copolymer [D] needs to be more than 65,000 and 120,000 or less. If the weight average molecular weight of the hydrogenated block copolymer [D] is 65,000 or less, the strength of the obtained molded article decreases and molding defects increase. On the other hand, if the weight average molecular weight of the hydrogenated block copolymer [D] exceeds 120,000, the fluidity of the resin composition during melting decreases, making processing difficult. As a result, the flatness of the molded article decreases. The weight average molecular weight of the hydrogenated block copolymer [D] is preferably more than 70,000 from the viewpoint of ensuring good strength of the molded article and further reducing molding defects. Further, from the viewpoint of sufficiently ensuring the fluidity of the resin composition during melting and further improving the flatness of the molded article, the weight average molecular weight of the hydrogenated block copolymer [D] is preferably 100,000 or less, and more preferably 95,000 or less.

[0046] <<Molecular Weight Distribution>> The molecular weight distribution (Mw / Mn) of the hydrogenated block copolymer [D] is preferably 3.0 or less, more preferably 2.0 or less, and still more preferably 1.81 or less. If the molecular weight distribution of the hydrogenated block copolymer [D] is not more than the above upper limit, good strength of the molded article can be ensured and molding defects can be further reduced. The lower limit of the molecular weight distribution of the hydrogenated block copolymer [D] is not particularly limited, and can be, for example, 1.1 or more, 1.3 or more, or 1.5 or more. In the present invention, the molecular weight distribution of the hydrogenated block copolymer [D] can be measured using the method described in the Examples of the present specification. Further, the weight average molecular weight and molecular weight distribution of the hydrogenated block copolymer [D] can be adjusted by changing the polymerization conditions, hydrogenation reaction conditions and the like of the precursor block copolymer [C]. Specifically, for example, the weight average molecular weight of the hydrogenated block copolymer [D] increases by decreasing the addition amount of the polymerization initiator used for polymerization of the block copolymer [C], and decreases by increasing the addition amount.

[0047] <<Block Structure>> Particularly preferred forms of the block copolymer hydride [D] include a triblock copolymer (A'-B'-A') in which polymer blocks [A'] are bonded to both ends of polymer block [B'], when polymer block [A'] is formed by hydrogenating polymer block [A] as described above, and polymer block [B'] is formed by hydrogenating polymer block [B] as described above, and polymer block [A'] is bonded to both ends of polymer block [B'], and a pentablock copolymer (A'-B'-A'-B'-A') in which polymer blocks [B'] are bonded to both ends of polymer block [A'], and polymer blocks [A'] are bonded to the other ends of the two polymer blocks [B'].

[0048] Furthermore, the block copolymer hydride [D] of the present invention has the property of being less susceptible to molecular structure cleavage by gamma-ray irradiation. Therefore, by using the block copolymer hydride [D] of the present invention, molded articles can be given resistance to gamma-ray sterilization.

[0049] <Method for preparing block copolymer hydride [D]> The block copolymer hydride [D] of the present invention can be prepared by subjecting its precursor, block copolymer [C], to a hydrogenation reaction, thereby hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains of block copolymer [C], as well as the carbon-carbon unsaturated bonds of the aromatic ring.

[0050] The method for producing the block copolymer [C] is not particularly limited, and known methods can be employed. Specifically, examples of methods for producing the block copolymer [C] include those described in International Publication No. 2003 / 018656 and International Publication No. 2011 / 096389.

[0051] Furthermore, the hydrogenation method and reaction mode of the unsaturated bonds of the block copolymer [C] are not particularly limited and can be carried out according to known methods. A hydrogenation method that can achieve a high hydrogenation rate and minimize polymer chain severance reactions is preferred. Examples of such hydrogenation methods include those described in International Publication No. 2011 / 096389 and International Publication No. 2012 / 043708.

[0052] After the hydrogenation reaction is complete, the hydrogenation catalyst, or the hydrogenation catalyst and polymerization catalyst, can be removed from the reaction solution, and then the solvent can be removed from the resulting solution to recover the block copolymer hydride [D].

[0053] (Resin Composition) The resin composition of the present invention comprises at least the block copolymer hydride [D] of the present invention described above. Preferably, the resin composition of the present invention further comprises a phenolic antioxidant and / or a phosphorus-based antioxidant. Since the resin composition of the present invention comprises the block copolymer hydride [D] of the present invention described above, it is possible to form a molded article with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence. The resin composition of the present invention may contain components other than the above components (block copolymer hydride [D] and phenolic antioxidant and / or phosphorus-based antioxidant), but from the viewpoint of further reducing autofluorescence of the molded article, it is preferable that it does not contain components other than the above components (block copolymer hydride [D] and phenolic antioxidant and / or phosphorus-based antioxidant).

[0054] Examples of phenolic antioxidants include acrylate compounds such as 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate and 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate; octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and 2,2'-methylene-bis(4-methyl-6-t-butylphenol). 1,1,3-Tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenylpropionate)methane [i.e., pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]], triethylene glycol-bis[3- Alkyl-substituted phenol compounds such as (3-t-butyl-4-hydroxy-5-methylphenyl)propionate; triazine group-containing phenol compounds such as 6-(4-hydroxy-3,5-di-t-butylanilino)-2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3,5-triazine, 2-octylthio-4,6-bis-(3,5-di-t-butyl-4-oxyanilino)-1,3,5-triazine; 6-t-butyl-4-[3-(2,4,8 Examples include hindered phenol antioxidants having a phosphorus atom in the molecule, such as 10-tetra-t-butyldibenzo[d,f][1,3,2]dioxaphosphine-6-yloxy)propyl]-o-cresol. Among these, tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenylpropionate)methane is preferred. These phenol antioxidants can be used individually or in combination of two or more.

[0055] Examples of phosphorus-based antioxidants include monophosphite compounds such as triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, tris(dinonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, and 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; and diphosphite compounds such as 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphite) and 4,4'isopropylidene-bis(phenyl-dialkyl(C12-C15) phosphite). Among these, tris(2,4-di-t-butylphenyl) phosphite is preferred. These phosphorus-based antioxidants can be used individually or in combination of two or more.

[0056] Furthermore, the total content of phosphorus-based antioxidants and phenol-based antioxidants per 100 parts by mass of block copolymer hydride [D] in the resin composition of the present invention is not particularly limited, but is preferably 0.05 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 2.0 parts by mass or less, and more preferably 1.0 part by mass or less. If the total content of phosphorus-based antioxidants and phenol-based antioxidants per 100 parts by mass of block copolymer hydride [D] is above the lower limit, oxidative degradation due to heat can be suppressed and autofluorescence can be further reduced. On the other hand, if the total content of phosphorus-based antioxidants and phenol-based antioxidants per 100 parts by mass of block copolymer hydride [D] is below the upper limit, mold contamination during molding can be reduced.

[0057] <Method for preparing the resin composition> The resin composition of the present invention can be prepared by mixing the above components by known mixing methods. Such mixing can be carried out using known melting and kneading machines such as single-screw extruders, twin-screw extruders, Banbury mixers, kneaders, and feeder extruders. After mixing, the mixture can be extruded into a rod shape according to conventional methods and cut into appropriate lengths with a strand cutter to form pellets.

[0058] (Molded Article) The molded article of the present invention is formed in which at least a part thereof is made using the resin composition of the present invention as described above. The molded article of the present invention may be formed entirely using the resin composition of the present invention, or only a part thereof may be formed using the resin composition of the present invention. In the latter case, the molded article of the present invention is composed of a member formed by molding the resin composition of the present invention (hereinafter sometimes referred to as the "molded member") and a member other than the molded member (other members). Since the molded article of the present invention is formed in which at least a part thereof is made using the resin composition of the present invention, it has excellent flatness, and molding defects, surface unevenness, and autofluorescence are reduced.

[0059] <Molded Member> The molded member is a member obtained by molding the resin composition of the present invention, and contains the block copolymer hydride [D] of the present invention described above, and optionally further contains a phenolic antioxidant and / or a phosphorus-based antioxidant. The relationship (content ratio) and attributes of the content of the block copolymer hydride [D], phenolic antioxidant and phosphorus-based antioxidant contained in the molded member are usually the same as the relationship (content ratio) and attributes of their content in the resin composition.

[0060] <Other Components> The molded article of the present invention may optionally have components other than the molded components described above (other components). Specific examples of other components include, for example, components other than the bottom surface of a microplate or dish (e.g., side walls and covers). Other components may be formed from, for example, known resin materials other than the resin composition of the present invention, metals, ceramics, etc.

[0061] Specific examples of the molded articles of the present invention include, but are not limited to, laboratory equipment. Preferred examples of laboratory equipment include, for example, microplates, dishes, petri dishes, and microfluidic devices used for fluorescence observation. Among these, microplates and dishes are preferred, with microplates being more preferred.

[0062] The microplate as a molded article of the present invention may be formed entirely using the resin composition of the present invention, or only a portion of the microplate may be formed using the resin composition of the present invention. From the viewpoint of further reducing autofluorescence, it is preferable that at least the bottom surface of the microplate is formed using the resin composition of the present invention. Furthermore, components other than the bottom surface of the microplate may be formed using the resin composition of the present invention, or they may be formed using resin compositions other than the resin composition of the present invention.

[0063] The molding method used to produce the molded body is not particularly limited and can be appropriately selected from known molding methods depending on the desired shape of the molded body. Examples of such known molding methods include extrusion molding, injection molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendering, foam molding, and thermoforming. Among these, injection molding is preferred as the molding method.

[0064] Furthermore, when the molded body of the present invention is composed of a molded member and other members, first, the molded member is manufactured by the molding method described above, and then, by performing insert injection molding using the obtained molded member, a molded body in which the molded member and other members are joined can be obtained.

[0065] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing quantities refer to mass unless otherwise specified. In addition, in copolymers produced by copolymerizing multiple types of monomers, the proportion of monomer units formed by polymerizing a certain monomer in the copolymer is usually equal to the ratio of that certain monomer to the total monomers used in the polymerization of the copolymer (starting ratio), unless otherwise specified. In the examples and comparative examples, various measurements and evaluations were performed by the following methods.

[0066] <Weight-average molecular weight and molecular weight distribution> For block copolymer [C] and block copolymer hydride [D], the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured using gel permeation chromatography (GPC), and the molecular weight distribution (Mw / Mn) was calculated. Specifically, a gel permeation chromatograph (Tosoh Corporation, product name "HLC8320GPC") was used. For block copolymer [C], tetrahydrofuran was used as the developing solvent to determine the weight-average molecular weight (Mw) and number-average molecular weight (Mn) as standard polystyrene equivalent values, and for block copolymer hydride [D], cyclohexane was used as the developing solvent to determine the weight-average molecular weight (Mw) and number-average molecular weight (Mn) as standard polyisoprene equivalent values. <Hydrogenation Rate> The hydrogenation rate of block copolymer hydride [D] is the ratio of hydrogenated carbon-carbon bonds to the total of the carbon-carbon unsaturated bonds in the aromatic rings contained in the structural units derived from the aromatic vinyl compound of the precursor block copolymer [C] and the carbon-carbon unsaturated bonds contained in the structural units derived from the chain-like conjugated diene compound. The hydrogenation rate of block copolymer hydride [D] is: １ It is calculated by H-NMR spectroscopy or GPC analysis. The region with a hydrogenation rate of 99% or less is １The H-NMR spectrum was measured and calculated, and for areas exceeding 99%, the area was calculated from the ratio of peak areas obtained by the UV detector and the RI detector using GPC analysis. <Molding defects> Ten 96-well microplates or dishes prepared in the examples and comparative examples were used as samples, and the appearance of the samples was visually inspected to count the number of locations where defects such as cracks and chips occurred. The following criteria were used for evaluation. The fewer the locations where defects occurred, the lower the molding defects. [Evaluation criteria] A: 0 locations where defects occurred B: 1 location where defects occurred C: 2 to 5 locations where defects occurred D: 6 or more locations where defects occurred <Flatness> The bottom height of ten 96-well microplates or dishes prepared in the examples and comparative examples was measured using a color 3D laser microscope (manufactured by Keyence Corporation, product name "VK-9700"), and the difference between the maximum height and the minimum height was determined. Specifically, for 96-well microplates, the bottom height was measured at a total of 96 points in the center of each well, and the difference between the maximum and minimum heights was calculated. Similar measurements were performed for all 10 microplates, and the average value was calculated. For dishes, five measurement points were set: one point in the center of the bottom of the dish, and four points (5 mm from the approximate center of the arc of each of the four sectors, when the bottom of the dish is divided into four 90-degree sectors) towards the center of the bottom of the dish. The bottom height was measured at each measurement point, and the difference between the maximum and minimum heights was calculated. Similar measurements were performed for all 10 dishes, and the average value was calculated. A smaller average difference between the maximum and minimum heights indicates better flatness.[Evaluation Criteria] A: The average difference between the maximum and minimum heights is 50 μm or less B: The average difference between the maximum and minimum heights is greater than 50 μm and 70 μm or less C: The average difference between the maximum and minimum heights is greater than 70 μm and 100 μm or less D: The average difference between the maximum and minimum heights is greater than 100 μm <Surface Irregularity> Ten 96-well microplates or dishes prepared in the examples and comparative examples were used as samples, and their appearance was visually inspected. Samples with any unevenness on even a small part of the surface were designated as surface irregularity samples, and the number of surface irregularity samples was counted. The following criteria were used for evaluation. A smaller number of surface irregularity samples indicates a reduction in surface irregularity. [Evaluation Criteria] A: Number of surface irregularity samples is 0 B: Number of surface irregularity samples is 1 C: Number of surface irregularity samples is 2 or more and 5 or less D: Number of surface irregularity samples is 6 or more <Dimensional Stability> The shape of the 96-well microplates or dishes prepared in the examples and comparative examples was measured using a high-precision image dimension measuring instrument (manufactured by Keyence Corporation, product name "LM-1000"). Specifically, for 96-well microplates, the longitudinal and transverse lengths of the outermost periphery of 10 96-well microplates were measured, and the standard deviations of the longitudinal and transverse lengths were calculated. The larger of the standard deviations of the longitudinal and transverse lengths was adopted. For dishes, the outermost diameter of 10 dishes was measured, and its standard deviation was calculated. The following criteria were used for evaluation. A smaller standard deviation indicates better dimensional stability. [Evaluation Criteria] A: Standard deviation of 10 μm or less B: Standard deviation of more than 10 μm and 50 μm or less C: Standard deviation of more than 50 μm and 250 μm or less D: Standard deviation of more than 250 μm <Autofluorescence> Using a fluorescence spectrophotometer (manufactured by JASCO Corporation, product name "FP-8500"), the 96-well microplates or dishes prepared in the examples and comparative examples were used as measurement samples, and the bottom surface of the measurement sample was set to cover the measurement section of the fluorescence spectrophotometer. The fluorescence intensity was then measured under the following measurement conditions, and the maximum fluorescence intensity in the range of 400 to 500 nm was determined. The same measurement was performed for 10 measurement samples, and the average value was calculated and taken as the autofluorescence value. The following criteria were used for evaluation.A smaller autofluorescence value indicates reduced autofluorescence. [Measurement conditions] Scanning speed: 500 nm / min Sensitivity: High Excitation wavelength: 365 nm Measurement wavelength: 400-500 nm [Evaluation criteria] S: Autofluorescence value of 30 or less A: Autofluorescence value greater than 30 and 40 or less B: Autofluorescence value greater than 40 and 60 or less C: Autofluorescence value greater than 60 and 100 or less D: Autofluorescence value greater than 100.

[0067] (Example 1) <Preparation of Block Copolymer [C]> In a reactor equipped with a stirring device and thoroughly purged with nitrogen, 400 parts of dehydrated cyclohexane, 20 parts of dehydrated styrene, and 0.22 parts of dibutyl ether were added. While stirring the entire mixture at 60°C, 0.45 parts of n-butyllithium (15% cyclohexane solution) were added to start polymerization, and stirring was continued at 60°C for 20 minutes after the start of polymerization. At this point (first polymerization stage), the reaction solution was analyzed by gas chromatography (hereinafter sometimes referred to as "GC") and GPC, and the polymerization conversion rate was 99.8%. Next, 20 parts of dehydrated isoprene were continuously added to the reaction solution over 40 minutes, and stirring was continued for 30 minutes after the completion of the addition. At this point (second polymerization stage), the reaction solution was analyzed by GC, and the polymerization conversion rate was 99.8%. Subsequently, 60 parts of dehydrated styrene were continuously added to the reaction solution over 200 minutes, and stirring was continued for 60 minutes after the completion of the addition. At this point (third polymerization stage), the reaction solution was analyzed by GC and found that the polymerization conversion rate was approximately 100%. Furthermore, analysis by GPC showed that Mw was 145,000 and Mw / Mn was 1.05. At this point, 0.2 parts of isopropyl alcohol were added to stop the reaction, thereby obtaining a polymer solution containing a block copolymer [C] having a [A]-[B]-[A] type triblock structure. <Preparation of block copolymer hydride [D]> Next, the polymer solution containing the block copolymer [C] was transferred to a pressure reactor equipped with a stirring device, and 4.0 parts of diatomaceous earth-supported nickel catalyst (manufactured by JGC Catalysts & Chemicals Co., Ltd., product name "E22U"; nickel support amount 60%) and 30 parts of dehydrated cyclohexane were added and mixed as hydrogenation catalysts. The inside of the reactor was purged with hydrogen gas, and hydrogen was supplied while stirring the solution, and the hydrogenation reaction was carried out at a temperature of 190°C and a pressure of 4.5 MPa for 6 hours. After the hydrogenation reaction was complete, the reaction solution was filtered to remove the hydrogenation catalyst, yielding block copolymer hydride [D]. The weight-average molecular weight, molecular weight distribution, and hydrogenation rate of this block copolymer hydride [D] were measured. The results are shown in Table 1.<Preparation of Resin Composition> To 100 parts (equivalent to solid content) of the block copolymer hydride [D] obtained above, 0.3 parts of tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenylpropionate)methane (manufactured by BASF Japan Ltd., product name "Irganox® 1010") as an antioxidant were mixed to obtain a resin composition. <Preparation of 96-well Microplate (Molded Body)> The resin composition obtained above was vacuum dried under the conditions of ambient temperature: 80°C and drying time: 4 hours (pre-drying). Then, using the pre-dried resin composition, injection molding was performed under the following conditions to produce a 96-well microplate as a molded body. The molding defects, flatness, surface unevenness, dimensional stability, and autofluorescence of this 96-well microplate were evaluated. The results are shown in Table 1. —Injection Molding Conditions— Injection molding machine: Japan Steel Works Ltd., product name "J110ELIII" Mold: Mold for 96-well microplate (compliant with ANSI / SBS standards) Cylinder temperature: 290°C Mold temperature: 90°C Injection pressure: 80 MPa Note that 5 shots were molded as sacrificial shots, followed by 10 shots molded as samples.

[0068] (Example 2) <Preparation of block copolymer [C], block copolymer hydride [D], and resin composition> Block copolymer [C], block copolymer hydride [D], and resin composition were obtained in the same manner as in Example 1. <Preparation of 96-well microplate (molded body)> The resin composition obtained in Example 1 was melted at 240°C using a film extrusion molding machine (single-screw extruder, φ=20 mm, manufactured by GSI Clayos), the molten resin was extruded from the T-die, and cooled to obtain a resin film with a thickness of 200 μm ± 10 μm and a width of 280 mm. A bottom film was obtained by cutting from the center of the resin film in the width direction to the size of the bottom surface of the 96-well microplate. The bottom film was set in a mold before molding, and a 96-well microplate was prepared in the same manner as in Example 1. The molding defects, flatness, surface unevenness, dimensional stability, and autofluorescence of this 96-well microplate were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0069] (Example 3) <Preparation of block copolymer [C] and block copolymer hydride [D]> Block copolymer [C] and block copolymer hydride [D] were obtained in the same manner as in Example 1. <Preparation of resin composition> 0.2 parts of tris(2,4-di-t-butylphenyl) phosphite (manufactured by Sumitomo Chemical Co., Ltd., product name "SumiLizer® GP") as an antioxidant were mixed with 100 parts (equivalent to solid content) of the obtained block copolymer hydride [D] to obtain a resin composition. <Preparation of dish (molded body)> The resin composition obtained above was vacuum dried under the conditions of ambient temperature: 80°C and drying time: 4 hours (pre-drying). Then, using the pre-dried resin composition, a dish was produced as a molded body by injection molding under the following conditions. The molding defects, flatness, surface unevenness, dimensional stability and autofluorescence of this dish were evaluated in the same manner as in Example 1. The results are shown in Table 1. —Injection molding conditions— Injection molding machine: FANUC Corporation, product name "RoboShot α-S50iA" Mold: Mold for a 35mm diameter dish Cylinder temperature: 270℃ Mold temperature: 100℃ Injection pressure: 70MPa In addition, 5 shots were molded as sacrificial shots, and then 10 shots were molded as samples.

[0070] (Example 4) Block copolymer [C], block copolymer hydride [D], resin composition, and 96-well microplate were obtained in the same manner as in Example 1, except that the hydrogenation reaction time was changed to 3 hours during the preparation of block copolymer [C]. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 1.

[0071] (Example 5) Block copolymer [C], block copolymer hydride [D], resin composition, and 96-well microplate were obtained in the same manner as in Example 1, except that the hydrogenation reaction was changed to 1 hour during the preparation of block copolymer [C]. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 1.

[0072] (Example 6) In the preparation of block copolymer [C], the dehydrated styrene was changed to 18 parts in the first polymerization stage, the dehydrated isoprene was changed to 30 parts in the second polymerization stage, and the dehydrated styrene was changed to 52 parts in the third polymerization stage, in the same manner as in Example 1, to obtain block copolymer [C] (Mw: 139,000, Mw / Mn: 1.07), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 1.

[0073] (Example 7) In the preparation of block copolymer [C], the same procedure as in Example 1 was used, except that 28 parts of dehydrated styrene, 0.20 parts of dibutyl ether, and 0.40 parts of n-butyllithium were changed in the first polymerization step, and 12 parts of dehydrated isoprene were changed in the second polymerization step. Block copolymer [C] (Mw: 158,800, Mw / Mn: 1.08), block copolymer hydride [D], resin composition, and 96-well microplate were obtained. The same procedure as in Example 1 was used for evaluation. The results are shown in Table 1.

[0074] (Example 8) In the preparation of block copolymer [C], the following was done in the same manner as in Example 1, except that in the first polymerization step, 15 parts of dehydrated styrene, 0.25 parts of dibutyl ether, and 0.50 parts of n-butyllithium were changed, in the second polymerization step, 12 parts of dehydrated isoprene were changed, and in the third polymerization step, 73 parts of dehydrated styrene were changed. Block copolymer [C] (Mw: 126, 100, Mw / Mn: 1.06), block copolymer hydride [D], resin composition, and 96-well microplate were obtained. The evaluation was then performed in the same manner as in Example 1. The results are shown in Table 1.

[0075] (Example 9) In the preparation of block copolymer [C], the amount of dehydrated styrene was changed to 28 parts, dibutyl ether to 0.18 parts, and n-butyllithium to 0.36 parts in the first polymerization step, and the amount of dehydrated styrene was changed to 52 parts in the third polymerization step. Except for these changes, the procedure was the same as in Example 1 to obtain block copolymer [C] (Mw: 186,400, Mw / Mn: 1.06), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then performed in the same manner as in Example 1. The results are shown in Table 2.

[0076] (Example 10) Except for the fact that when preparing block copolymer [C], 0.25 parts of dibutyl ether and 0.50 parts of n-butyllithium were changed in the first polymerization step, and 20 parts of dehydrated isoprene were changed in the second polymerization step to 20 parts of dehydrated 1,3-butadiene, the procedure was the same as in Example 1 to obtain block copolymer [C] (Mw: 122,600, Mw / Mn: 1.07), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then performed in the same manner as in Example 1. The results are shown in Table 2.

[0077] (Comparative Example 1) Block copolymer [C], block copolymer hydride [D], resin composition, and 96-well microplate were obtained in the same manner as in Example 1, except that the hydrogenation reaction time was changed to 0.5 hours during the preparation of block copolymer [C]. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 2.

[0078] (Comparative Example 2) Except that the preparation of block copolymer [C] was carried out in the same manner as in Example 1, except that in the first polymerization step, 10 parts of dehydrated styrene, 0.23 parts of dibutyl ether, and 0.46 parts of n-butyllithium were changed, in the second polymerization step, 40 parts of dehydrated isoprene were changed, and in the third polymerization step, 50 parts of dehydrated styrene were changed, block copolymer [C] (Mw: 134,600, Mw / Mn: 1.07), block copolymer hydride [D], resin composition, and 96-well microplate were obtained. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 2.

[0079] (Comparative Example 3) Except for changing the amount of dehydrated isoprene to 5 parts in the second polymerization step and the amount of dehydrated styrene to 75 parts in the third polymerization step during the preparation of block copolymer [C], the procedure was the same as in Example 1 to obtain block copolymer [C] (Mw: 138, 100, Mw / Mn: 1.09), block copolymer hydride [D], a resin composition, and a 96-well microplate. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 2.

[0080] (Comparative Example 4) Except for the fact that when preparing block copolymer [C], 40 parts of dehydrated styrene, 0.23 parts of dibutyl ether, and 0.46 parts of n-butyllithium were changed in the first polymerization step, and 40 parts of dehydrated styrene were changed in the third polymerization step, the procedure was the same as in Example 1 to obtain block copolymer [C] (Mw: 141,600, Mw / Mn: 1.06), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then performed in the same manner as in Example 1. The results are shown in Table 2.

[0081] (Comparative Example 5) Except that the amount of dibutyl ether was changed to 0.32 parts and n-butyllithium to 0.64 parts during the first polymerization step of the preparation of block copolymer [C] was the same as in Example 1, to obtain block copolymer [C] (Mw: 100, 100, Mw / Mn: 1.06), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 2.

[0082] (Comparative Example 6) Except that the amount of dibutyl ether was changed to 0.15 parts and n-butyllithium to 0.30 parts during the first polymerization step of the preparation of block copolymer [C] was the same as in Example 1, to obtain block copolymer [C] (Mw: 214,000, Mw / Mn: 1.10), block copolymer hydride [D], resin composition, and 96-well microplate. The evaluation was then carried out in the same manner as in Example 1. The results are shown in Table 2.

[0083] In Tables 1 and 2 below, "ST" represents styrene, "IP" represents isoprene, "BD" represents 1,3-butadiene, "Mw" represents weight-average molecular weight, "Mw / Mn" represents molecular weight distribution, "IRG" represents tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenylpropionate)methane, "GP" represents tris(2,4-di-t-butylphenyl)phosphite, and "96 plate" represents a 96-well microplate. Also, in Tables 1 and 2, "wA1 / wA2" is shown as a value rounded to the third decimal place.

[0084]

[0085]

[0086] Tables 1-2 show that in Examples 1-10, which used the specified block copolymer hydride [D], molded articles with excellent flatness, reduced molding defects, surface unevenness, and autofluorescence were formed. On the other hand, in Comparative Example 1, which used block copolymer hydride [D] with a hydrogenation rate of less than 95%, it was not possible to form a molded article with reduced autofluorescence. Furthermore, in Comparative Example 2, which used block copolymer hydride [D] where wA / wB and wA2 were outside the specified range, it was not possible to form a molded article with reduced surface unevenness. Finally, in Comparative Example 3, which used block copolymer hydride [D] where wA / wB was outside the specified range, Comparative Example 4, which used block copolymer hydride [D] where wA1 and wA2 were outside the specified range, and Comparative Example 5, which used block copolymer hydride [D] where the weight-average molecular weight was outside the specified range, it was not possible to form molded articles with reduced molding defects. Furthermore, in Comparative Example 6, which uses a block copolymer hydride [D] whose weight-average molecular weight is outside the specified range, it can be seen that a molded article with excellent flatness could not be formed.

[0087] According to the present invention, it is possible to provide block copolymer hydrides and resin compositions that can form molded articles with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence. Furthermore, according to the present invention, it is possible to provide molded articles with excellent flatness and reduced molding defects, surface unevenness, and autofluorescence.

Claims

1. A block copolymer hydride [D] obtained by hydrogenating the carbon-carbon unsaturated bonds of the main chain and side chains and the carbon-carbon unsaturated bonds of the aromatic ring of a block copolymer [C] comprising at least two polymer blocks [A] mainly composed of structural units derived from aromatic vinyl compounds and at least one polymer block [B] mainly composed of structural units derived from a chain-like conjugated diene compound, wherein when wA is the mass fraction of structural units derived from all aromatic vinyl compounds in the entire block copolymer [C] and wB is the mass fraction of structural units derived from all chain-like conjugated diene compounds in the entire block copolymer [C], the ratio of wA to wB (wA / wB) is 65 / 35 or more and 90 / 10 or less, and the at least two polymer blocks [A] include polymer block [A1] and polymer block [A2]. A block copolymer hydride wherein the mass fraction of polymer block [A2] in the block copolymer [C] is lower than the mass fraction of polymer block [A1] in the block copolymer [C], the mass fraction (wA1) of structural units derived from aromatic vinyl compounds in polymer block [A1] in the entire block copolymer [C] is 50% by mass or more and 75% by mass or less, the mass fraction (wA2) of structural units derived from aromatic vinyl compounds in polymer block [A2] in the entire block copolymer [C] is 15% by mass or more and 30% by mass or less, and the weight-average molecular weight of the block copolymer hydride [D] is more than 65,000 and 120,000 or less.

2. The block copolymer hydride according to claim 1, wherein the block copolymer hydride [D] has a triblock structure consisting of two polymer blocks formed by hydrogenating polymer block [A] and one polymer block formed by hydrogenating polymer block [B], or a pentablock structure consisting of three polymer blocks formed by hydrogenating polymer block [A] and two polymer blocks formed by hydrogenating polymer block [B].

3. A resin composition comprising the block copolymer hydride according to claim 1 or 2.

4. A molded article, wherein at least a portion of the molded article is formed by molding the resin composition described in claim 3.

5. The molded body according to claim 4, which is an experimental apparatus.

6. The molded body according to claim 4, which is a microplate.

7. The molded article according to claim 4, used for fluorescence observation.

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