JP2014133848A - Method of manufacturing molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded body having high heat resistance even during high temperature steam sterilization.SOLUTION: A molded body is manufactured by contacting water with a preforming body consisting of a polymer composition containing a silanol condensation catalyst and a modified block copolymer hydride [3] made by introducing an alkoxysilyl group into a block copolymer hydride [2] made by hydrogenation of 90% or more of all unsaturated bonds of a block copolymer [1] consisting of at least two copolymer blocks [A] mainly containing a repeating unit derived from an aromatic vinyl compound and at least one copolymer block [B] mainly containing a repeating unit derived from a linear conjugated diene compound with a ratio between wA and wB (wA:wB) of 20:80 to 65:35, where wA and wB are weight fractions of the polymer block [A] and the polymer block [B] in the whole polymer respectively. Contact with water is preferably conducted under a heating condition.

Description

  The present invention relates to a method for producing a molded article having excellent transparency and heat resistance during high-temperature steam sterilization.

  In the medical field, medical devices such as catheters, tubes, and tracheal tubes are made of flexible polymer materials. As the polymer material, thermoplastic plastics and thermoplastic elastomers having good moldability are used. Among them, soft polyvinyl chloride excellent in flexibility and transparency (hereinafter abbreviated as soft PVC), low density polyethylene (abbreviated as LDPE in the following description), and ultra-low density polyethylene (abbreviated as VLDPE in the following description). Etc. are used.

  However, soft PVC, LDPE, VLDPE, etc. have a low softening temperature, so that medical devices made from these polymer materials cannot be steam sterilized. Moreover, the soft PVC material utilized for a medical device usually contains a plasticizer in order to obtain a desired flexibility. Since the plasticizer is physically mixed with the soft PVC, the plasticizer may ooze out into the environment in contact with the soft PVC and be mixed into the body. On the other hand, LDPE and VLDPE have less plasticizer than soft PVC, but there is also a concern that low molecular weight oligomers are likely to elute.

  Medical devices using block copolymer hydrides obtained from aromatic vinyl compounds and conjugated dienes have been proposed as transparent polymer materials with excellent flexibility, low elution, high heat resistance and steam sterilization. (For example, Patent Document 1 and Patent Document 2). This polymer material provides steam sterilization resistance because the glass transition temperature of the polymer block hydride made of an aromatic vinyl compound is as high as 120 to 140 ° C. It cannot be said that it has sufficient heat resistance.

  Steam sterilization allows rapid heating when saturated water vapor reaches the object to be sterilized, and heat quickly penetrates deeply into the object to be sterilized, so that microorganisms that adhere to or exist inside the object to be sterilized can be removed in a relatively short time. Since it can be surely killed, it is widely used in medical institutions. Steam sterilization conditions include 115 ° C. for 30 minutes, 121 ° C. for 15 minutes, and 134 ° C. for 8 to 10 minutes. In many cases, more reliable high temperature steam sterilization at 134 ° C. is used. Therefore, a transparent and flexible polymer material that can withstand such high-temperature steam sterilization is desired.

  Patent Document 3 discloses a block copolymer obtained from an aromatic vinyl compound and a conjugated diene as a material having heat resistance, light resistance, transparency and flexibility, and having strong adhesion to glass. A block copolymer hydride having an alkoxysilyl group in which an alkoxysilyl group is introduced into a block copolymer hydride obtained by hydrogenating both the aromatic vinyl polymer block and the conjugated diene polymer block has been proposed. However, it is disclosed that this is characterized by flexibility, adhesion to glass, and the like, and can be used as a solar cell sealing material in the form of a sheet.

International Publication WO2000 / 077094 JP 2003-82113 A International Publication WO2012 / 043708

  As a result of diligent investigation to solve the lack of heat resistance during high-temperature steam sterilization of medical equipment using a block copolymer hydride obtained from an aromatic vinyl compound and a conjugated diene. By blending a silanol condensation catalyst with a block copolymer hydride having a specific alkoxysilyl group as disclosed in Patent Document 3, and molding the preform, the preform is brought into contact with water. The inventors have found that a molded product having high heat resistance can be obtained even during high-temperature steam sterilization, and have completed the present invention.

  Thus, according to the present invention, at least two polymer blocks [A] mainly composed of a repeating unit derived from an aromatic vinyl compound and a polymer block mainly composed of a repeating unit derived from a chain conjugated diene compound [A] B], where wA and wB are the weight fractions of the polymer block [A] and the polymer block [B] occupying the whole polymer, and the ratio of wA to wB (wA: wB ) Is from 20:80 to 65:35 In the block copolymer hydride [2] in which 90% or more of all unsaturated bonds are hydrogenated, an alkoxysilyl group is introduced. Provided is a method for producing a molded product, characterized in that water is brought into contact with a preformed product comprising a polymer composition containing a modified block copolymer hydride [3] and a silanol condensation catalyst. That. The contact between the preform and water is preferably performed under heating conditions.

  The block copolymer hydride used in the present invention comprises at least two polymer blocks [A] mainly comprising a repeating unit derived from an aromatic vinyl compound and a repeating unit derived from a chain conjugated diene compound as a main component. The entire block copolymer of all the polymer blocks [B] is composed of at least one polymer block [B], and the weight fraction of the entire polymer block [A] in the entire block copolymer is wA. 90% or more of the total unsaturated bonds of the block copolymer [1] in which the ratio of wA to wB (wA: wB) is 20:80 to 65:35 This is a block copolymer hydride [3] obtained by introducing an alkoxysilyl group into a hydrogenated block copolymer hydride [2].

1. Block copolymer [1]
The block copolymer [1] according to the present invention contains at least two polymer blocks [A] and at least one polymer block [B].
When the weight fraction of the polymer block [A] and the polymer block [B] in the entire polymer is wA and wB, the ratio of wA to wB (wA: wB) is 20:80 to 65 : 35.

  The polymer block [A] is mainly composed of a repeating unit derived from an aromatic vinyl compound, and the content of the repeating unit derived from the aromatic vinyl compound in the polymer block [A] is usually 90% by weight. Above, preferably 95% by weight or more, more preferably 99% by weight or more. The component other than the repeating unit derived from the aromatic vinyl compound in the polymer block [A] includes a repeating unit derived from a chain conjugated diene and / or a repeating unit derived from another ethylenically unsaturated compound. The content thereof is usually 10% by weight or less, preferably 5% by weight or less, more preferably 1% by weight or less. When there are too few repeating units derived from the aromatic vinyl compound in the polymer block [A], the heat resistance of the molded product may be lowered.

  The plurality of polymer blocks [A] may be the same as or different from each other as long as the above range is satisfied.

The polymer block [B] has a repeating unit derived from a chain conjugated diene compound as a main component, and the content of the repeating unit derived from a chain conjugated diene compound in the polymer block [B] is usually 90. % By weight or more, preferably 95% by weight or more, more preferably 99% by weight or more. When the repeating unit derived from the chain conjugated diene compound is in the above range, the molded article of the present invention is excellent in flexibility and impact resistance.
Moreover, as a component other than the repeating unit derived from the chain conjugated diene compound in the polymer block [B], a repeating unit derived from an aromatic vinyl compound and / or a repeating unit derived from another ethylenically unsaturated compound is included. The content thereof is usually 10% by weight or less, preferably 5% by weight or less, more preferably 1% by weight or less. If the content of the repeating unit derived from the aromatic vinyl compound and / or the repeating unit derived from another ethylenic compound in the polymer block [B] is increased, the flexibility and impact resistance of the molded product may be lowered. .

  When there are a plurality of polymer blocks [B], the polymer blocks [B] may be the same as or different from each other as long as the above range is satisfied.

  Specific examples of the aromatic vinyl compound include styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, Examples thereof include 5-t-butyl-2-methylstyrene, and those that do not contain a polar group are preferable in terms of hygroscopicity, and styrene is particularly preferable in terms of industrial availability.

  Specific examples of the chain conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, etc., and are polar in terms of hygroscopicity. Those not containing a group are preferred, and 1,3-butadiene and isoprene are particularly preferred because of excellent polymerization controllability.

  Examples of other ethylenically unsaturated compounds include chain ethylenically unsaturated compounds and cyclic ethylenically unsaturated compounds. These ethylenically unsaturated compounds may have a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, an acid anhydride group or a halogen group. Specifically, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, 4-methyl-1 -Chain olefins such as pentene and 4,6-dimethyl-1-heptene; those containing no polar group such as cyclic olefins such as vinylcyclohexane are preferred in terms of hygroscopicity, chain olefins are more preferred, ethylene, Propylene is particularly preferred.

  The number of polymer blocks [A] in the block copolymer [1] is usually 4 or less, preferably 3 or less, more preferably 2, and the number of polymer blocks [B] is usually 3 One or less, preferably two or less, more preferably one. When there are a plurality of polymer blocks [A], the weight average molecular weights of the polymer block having the largest and smallest weight average molecular weight in the polymer block [A] are Mw (A1) and Mw (A2), respectively. The ratio Mw (A1) / Mw (A2) between Mw (A1) and Mw (A2) is 2.0 or less, preferably 1.5 or less, more preferably 1.2 or less. Further, when there are a plurality of polymer blocks [B], the weight average molecular weights of the polymer block [B] having the largest and smallest weight average molecular weight are Mw (B1) and Mw (B2), respectively. The ratio Mw (B1) / Mw (B2) of Mw (B1) and Mw (B2) is 2.0 or less, preferably 1.5 or less, more preferably 1.2 or less.

  The block form of the block copolymer [1] may be a chain type block or a radial type block, but a block type block is preferred because of its excellent mechanical strength. The most preferable form of the block copolymer [1] is a triblock copolymer in which the polymer block [A] is bonded to both ends of the polymer block [B].

  In the block copolymer [1], the weight fraction of the whole polymer block [A] in the entire block copolymer is wA, and the weight fraction in which the whole polymer block [B] is in the whole block copolymer. When wB is wB, the ratio of wA to wB (wA: wB) is 20:80 to 65:35, preferably 30:70 to 60:40, more preferably 40:60 to 55:45. If the wA is too much, the heat resistance of the molded article is high, but the flexibility is low and the impact resistance is inferior. If the wA is too small, the heat resistance is inferior, which is not preferable.

  The molecular weight of the block copolymer [1] is a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC using tetrahydrofuran (THF) as a solvent, and is usually 35,000 to 200,000, preferably 40,000 to It is 150,000, More preferably, it is 45,000-100,000. Further, the molecular weight distribution (Mw / Mn) of the block copolymer [1] is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less.

  For example, when a block copolymer having three polymer blocks is produced, the production method of the block copolymer [1] is a monomer component for forming the polymer block [A] by a method such as living anion polymerization. First step of polymerizing monomer mixture (a1) containing aromatic vinyl compound as main component, and monomer mixture containing chain conjugated diene compound as main component as monomer component for forming polymer block [B] The monomer mixture (a2) (however, the monomer mixture (a1) and the monomer mixture) containing the aromatic vinyl compound as a main component as the monomer component for forming the polymer block [A] in the second step of polymerizing (b1) (A2) may be the same or different.) A method comprising a third step of polymerizing; As a monomer component for forming the block [A], a first step of polymerizing a monomer mixture (a1) containing an aromatic vinyl compound as a main component, and a monomer component for forming the polymer block [B] as a chain There are a second step of polymerizing the monomer mixture (b1) containing a conjugated diene compound as a main component, and a method of coupling the ends of the polymer block [B] with a coupling agent.

  For example, when producing a block copolymer having five polymer blocks, a monomer mixture (a1) containing an aromatic vinyl compound as a main component is polymerized as a monomer component for forming the polymer block [A]. A first step, a second step of polymerizing a monomer mixture (b1) containing a chain conjugated diene compound as a main component as a monomer component for forming the polymer block [B], and a polymer block [A] A third step of polymerizing a monomer mixture (a2) containing an aromatic vinyl compound as a main component as a monomer component (however, the monomer mixture (a1) and the monomer mixture (a2) may be the same or different) As a monomer component for forming the polymer block [B], a chain conjugated diene compound is included as a main component. As a monomer component for forming the polymer block [A], a fourth step of polymerizing the monomer mixture (b2) (wherein the monomer mixture (b1) and the monomer mixture (b2) may be the same or different), and A method comprising a fifth step of polymerizing a monomer mixture (a3) containing an aromatic vinyl compound as a main component (provided that the monomer mixture (a3) and the monomer mixture (a1 and a2) may be the same or different); As a monomer component for forming the polymer block [A], a first step of polymerizing a monomer mixture (a1) containing an aromatic vinyl compound as a main component, and a monomer component for forming the polymer block [B] as a chain A second step of polymerizing a monomer mixture (b1) containing a conjugated diene compound as a main component, and polymerization One polymer block in which the ends of the block [B] are coupled with each other by a tetrafunctional coupling agent, and the four polymer blocks [A] and the four polymer blocks [B] are bonded in a radial form. [B ′] includes a method of forming a block copolymer having five polymer blocks as a whole polymer.

2. Block copolymer hydride [2]
The block copolymer hydride [2] according to the present invention hydrogenates the carbon-carbon unsaturated bond of the main chain and the side chain of the block copolymer [1] and the carbon-carbon unsaturated bond of the aromatic ring. The hydrogenation rate is usually 90% or more, preferably 97% or more, more preferably 99% or more. The higher the hydrogenation rate, the better the weather resistance and heat resistance of the molded body. The hydrogenation rate of the block copolymer hydride [2] can be determined by measurement by ¹ H-NMR.

  There are no particular restrictions on the hydrogenation method or reaction mode of the unsaturated bond, and it may be carried out according to a known method. However, a hydrogenation method that can increase the hydrogenation rate and has little polymer chain scission reaction is preferred. Examples of such a hydrogenation method include methods described in International Publication WO2011 / 096389, International Publication WO2012 / 043708, and the like.

  The block copolymer hydride [2] obtained by the above method is recovered from the reaction solution after removing the hydrogenation catalyst and / or the polymerization catalyst from the reaction solution containing the block copolymer hydride [2]. The Although the form of the recovered block copolymer hydride [2] is not limited, it can usually be formed into a pellet and used for the subsequent introduction reaction of alkoxysilyl groups.

  The molecular weight of the block copolymer hydride [2] is a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and is usually 35,000 to 200, 000, preferably 40,000 to 150,000, more preferably 45,000 to 100,000. The molecular weight distribution (Mw / Mn) of the block copolymer hydride [2] is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less. When Mw and Mw / Mn are within the above ranges, the mechanical strength and heat resistance of the molded body are improved.

3. Modified block copolymer hydride [3]
The modified block copolymer hydride [3] used in the present invention is obtained by introducing an alkoxysilyl group into the block copolymer hydride [2]. The alkoxysilyl group may be directly bonded to the block copolymer hydride [2] or may be bonded via a divalent organic group such as an alkylene group.

  As the method for introducing an alkoxysilyl group, a method in which the above block copolymer hydride [2] is reacted with an ethylenically unsaturated silane compound in the presence of a peroxide is usually preferred.

The introduction amount of the alkoxysilyl group is usually 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, more preferably 0.3 to 100 parts by weight with respect to 100 parts by weight of the block copolymer hydride [2]. 3 parts by weight. If the amount of introduced alkoxysilyl groups is too large, the degree of cross-linking between alkoxysilyl groups decomposed with a small amount of moisture before being melt-formed into a desired shape increases, resulting in gel formation or fluidity during melting. This causes problems such as lowering of moldability and moldability. If the introduction amount of the alkoxysilyl group is too small, the crosslinkability at the time of crosslinking is lowered in the presence of water, and this causes a problem that sufficient heat resistance is not imparted. The introduction of the alkoxysilyl group can be confirmed by IR spectrum, and the introduction amount can be determined by measurement by ¹ H-NMR.

  The ethylenically unsaturated silane compound is not particularly limited as long as it is graft-polymerized with the above-mentioned block copolymer hydride [2] and introduces an alkoxysilyl group into the block copolymer hydride [2]. For example, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, and p-styryltrimethoxysilane are preferably used.

  These ethylenically unsaturated silane compounds may be used alone or in combination of two or more. The amount of the ethylenically unsaturated silane compound used is usually 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, more preferably 0, per 100 parts by weight of the block copolymer hydride [2]. .3 to 3 parts by weight.

  As the peroxide, those having a one-minute half-life temperature of 170 to 190 ° C. are preferably used. For example, t-butylcumyl peroxide, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl -2,5-di (t-butylperoxy) hexane, di-t-butylperoxide and the like are preferably used.

  These peroxides may be used alone or in combination of two or more. The amount of peroxide used is generally 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, more preferably 0.2 to 100 parts by weight with respect to 100 parts by weight of the block copolymer hydride [2]. 0.5 weight.

  The method of reacting the block copolymer hydride [2] with the ethylenically unsaturated silane compound in the presence of a peroxide is not particularly limited. For example, a desired temperature at a desired temperature in a twin-screw kneader is used. An alkoxysilyl group can be introduced by kneading for a time. In the block copolymer hydride [2] of the present invention, the temperature is usually 180 to 220 ° C, preferably 185 to 210 ° C, more preferably 190 to 200 ° C. The heat kneading time is usually about 0.1 to 10 minutes, preferably about 0.2 to 5 minutes, and more preferably about 0.3 to 2 minutes. What is necessary is just to knead | mix and extrude continuously so that temperature and residence time may become the said range.

  The molecular weight of the modified block copolymer hydride [3] according to the present invention is substantially the same as the molecular weight of the block copolymer hydride [2] used as a raw material because the amount of alkoxysilyl groups introduced is small. Although it does not change, since it reacts with the ethylenically unsaturated silane compound in the presence of a peroxide, the cross-linking reaction and the cleavage reaction of the polymer occur together, and the molecular weight distribution becomes large. The polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent is usually from 35,000 to 200,000, preferably from 40,000 to 150,000. Preferably, it is 45,000-100,000, and molecular weight distribution (Mw / Mn) is 3.5 or less normally, Preferably it is 2.5 or less, Most preferably, it is 2.0 or less. When Mw and Mw / Mn are within this range, the mechanical strength and heat resistance of the molded product are maintained.

  The modified block copolymer hydride [3] obtained as described above is imparted with crosslinkability in the presence of water, and a molded product obtained using the modified block copolymer hydride [3] Heat resistance is improved, and deformation is difficult even with high-temperature steam sterilization.

4). In the present invention, in order to improve the light resistance, heat resistance and the like of the obtained molded product, the modified block copolymer hydride [3] is added with a light stabilizer, an ultraviolet absorber, an antioxidant, a lubricant, You may add an inorganic filler etc. individually or in combination of 2 or more types.

(Light stabilizer)
As the light stabilizer, a hindered amine light stabilizer is preferable, and 3,5-di-tert-butyl-4-hydroxyphenyl group, 2,2,6,6-tetramethylpiperidyl group, or 1, Examples thereof include a compound having a 2,2,6,6-pentamethyl-4-piperidyl group.

  As specific examples, N, N′-bis (2,2,6,6-tetramethyl-4-N-methylpiperidyl) -N, N′-diformyl-alkylenediamine having excellent weather resistance, N, N '-Bis (2,2,6,6-tetramethyl-4-piperidyl) -N, N'-diformylalkylenediamine, N, N'-bis (2,2,6,6-tetramethyl-4 -Piperidyl) -N, N′-bisalkylene fatty acid amides, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} { (2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] is preferred, and N, N′-bis ( 2,2,6,6-tetramethyl-4-piperidyl) -N N′-diformylalkylenediamines, N, N′-bis (2,2,6,6-tetramethyl-4-piperidinyl) -1,6-hexanediamine and 2,4,6-trichloro-1,3 , 5-triazine, a reaction product of N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidineamine is preferred.

  The amount of the hindered amine light-resistant stabilizer is usually 0.001 to 2 parts by weight, preferably 0.002 to 1 part by weight, more preferably 0, per 100 parts by weight of the modified block copolymer hydride [3]. 0.005 to 0.5 parts by weight. When the amount of the hindered amine light stabilizer is less than this, the light resistance of the molded product may be insufficient. When the amount is more than this, extrusion may be performed during the melt molding process of the modified block copolymer hydride [3]. The dirt on the T-die and cooling roll of the machine is liable to become severe, which is not preferable.

(UV absorber)
As the UV absorber, a benzophenone UV absorber, a salicylic acid UV absorber, a benzotriazole UV absorber, or the like can be blended.

  Specific examples of the benzophenone ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy- 4-octyloxybenzophenone, 4-dodecaloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4 ′ -Dimethoxybenzophenone, etc .; salicylic acid-based UV absorbers include phenylsulcylate, 4-t-butylphenyl-2-hydroxybenzoate, phenyl-2-hydroxybenzoate, 2,4-di-t-butylphenyl-3, 5-di-t-butyl-4 Hydroxybenzoate, hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, etc .; As the benzotriazole ultraviolet absorber, 2- (2-hydroxy-5-methylphenyl) 2H-benzotriazole, 2- ( 3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro-2H- Benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl)- 2H-benzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2- Droxy-5-t-octylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octylphenyl) -2H-benzotriazole, 2- (2H-benzotriazol-2-yl) -4-methyl- 6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazole -2-yl) phenol]] and the like.

  The amount of the ultraviolet absorber is usually 0.01 to 1 part by weight, preferably 0.02 to 0.8 part by weight, and more preferably 0.001 part by weight with respect to 100 parts by weight of the modified block copolymer hydride [3]. 04 to 0.5 parts by weight. When the amount of the ultraviolet absorber is less than this, the light resistance of the molded product may be insufficient, and even if it is added excessively beyond this, no further improvement is observed.

(Antioxidant)
In the present invention, thermal stability can be further improved by blending the modified block copolymer hydride [3] with an antioxidant in addition to the hindered amine light resistance stabilizer and the ultraviolet absorber. Examples of the antioxidant that can be added include phosphorus-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, and the like, and phosphorus-based antioxidants with less coloring are preferred.

  Specific examples of antioxidants include, for example, phosphorus antioxidants such as triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite. Tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphat Monophosphite compounds such as phenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecylphosphite), 4,4′-isopropylidene-bis Diphosphite compounds such as (phenyl-di-alkyl (C12-C15) phosphite); -[3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetrakis-t-butyldibenzo [d, f] [1.3.2] di Oxaphosphepine, 6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -2,4,8,10-tetrakis-t-butyldibenzo [d, f] [1 3.2] Compounds such as dioxaphosphine can be mentioned.

  Examples of phenolic antioxidants include pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) proonyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5 -A compound such as trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene.

  Examples of sulfur-based antioxidants include dilauryl-3,3′-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, laurylstearyl-3,3. '-Thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate, 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] Examples include compounds such as undecane.

  The amount of the antioxidant is usually 0.01 to 2 parts by weight, preferably 0.05 to 1.5 parts by weight, more preferably 0, per 100 parts by weight of the modified block copolymer hydride [3]. .1 to 1 part by weight. If the amount of the antioxidant is less than this, the final molded article may have insufficient heat stability, and even if it is added in excess, the further improvement in heat stability will not be achieved. Few.

  Examples of the method for uniformly dispersing the compounding agent in the modified block copolymer hydride include a method of blending the modified block copolymer hydride [3] by melt-kneading with a biaxial kneader or the like. .

5. Preliminary body The preform body according to the present invention is obtained from a polymer composition obtained by blending a silanol condensation catalyst with the above-mentioned modified block copolymer hydride [3].

  The silanol condensation catalyst is not particularly limited as long as it can crosslink the block copolymer hydride [3] having an alkoxysilyl group in the presence of water. For example, tin, zinc, iron, lead, cobalt, etc. Examples thereof include metal carboxylates, titanate esters, organic bases, inorganic acids, and organic acids.

  Specifically, calcium stearate, tetrabutyl orthotitanate, tetranonyl orthotitanate, titanium-i-propoxyoctylene glycolate, diisopropyl bis (acetylacetonyl) titanate, diisopropyl bis (ethylacetoacetyl) titanate, tetrabutyl titanate, Aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate zinc caprylate, zinc stearate, dibutyltin dilaurate, dibutyltin diolate, stannous octoate, cobalt naphthenate, barium stearate, di Illustrate butylamine, hexylamine, pyridine, sulfuric acid, hydrochloric acid, toluenesulfonic acid, acetic acid, stearic acid, maleic acid, etc. It can be. Preferably, titanic acid tetrabutyl ester, titanic acid tetranonyl ester, titanium-i-propoxyoctylene glycolate, diisopropyl bis (acetylacetonyl) titanate, diisopropyl bis (ethylacetoacetyl) titanate, zinc stearate, dibutyltin dilaurate Etc.

  The amount of the silanol condensation catalyst is preferably in the range of 0.01 to 1.00 parts by weight with respect to 100 parts by weight of the modified block copolymer hydride [3]. More preferably, it exists in the range of 0.05-0.20 weight part.

  The silanol condensation catalyst is prepared, for example, by preparing pellets of a catalyst master batch obtained by adding 0.2 to 1.0 part by weight to the block copolymer hydride [2], and preparing this with the modified block copolymer hydride [3]. 2 to 10 parts by weight is mixed with 100 parts by weight of the pellets. The mixed pellets are formed into a tube or a sheet by an extrusion molding machine, for example.

6). Production of Molded Body The production method of the present invention comprises preliminarily molding a polymer composition in which a silanol condensation catalyst is blended with the above-described modified block copolymer hydride [3] into a tube, a sheet, and the like. It is characterized by contacting the product with water.
The contact method with water is a method of placing in an environment containing steam (usually humidity of 50% RH or more, preferably 80% RH or more, more preferably 90% RH or more), or spraying steam or water directly on the preform. And a method of immersing the preform in water.
The contact time between the preform and water can be adjusted according to the temperature of the water in contact, and is usually about 1 hour to 1 week. If the temperature of the water to be contacted is high, the contact time can be shortened. From the viewpoint of productivity, the temperature is preferably from room temperature to 100 ° C., and a condition of about 3 hours to 24 hours is employed.
By this water contact, crosslinking proceeded by condensation reaction between the alkoxysilyl groups of the modified block copolymer hydride [3] constituting the preform, and the preform was obtained by post-crosslinking. It is considered that the heat resistance of the molded body is improved and high shape retention can be obtained even at a high temperature steam sterilization treatment at 134 ° C.

  The molded product obtained by the method of the present invention has a heat resistance during high-temperature steam sterilization while maintaining the transparency, flexibility and low elution property of the block copolymer hydride obtained from an aromatic vinyl compound and a conjugated diene. Excellent in properties. Therefore, for example, medical devices such as catheters, tubes, blood circuits, tracheal tubes; medical containers such as infusion bags, blood bags, vein bags, intravenous solution bags, dialysis bags, ampoules, vials; scalpels, forceps, gauze -It is suitable as a medical container such as a sterilization container such as a tray for storing contact lenses and medical devices and its lid. Other applications include culture vessels such as bioreactors, culture plates, petri dishes, trays; radiator tanks, bumpers, lamp housings, instrument panels, air cleaner housings, over fenders, cowl louvers, car heater cases, cooling fans , Grill guard, side step, side protector, side molding, side lower skirt, seat back, trim, battery case, fan shroud, front grille, wheel cap, rear spoiler, roof rail and other automotive parts; wire covering material, high frequency antenna base Materials, coil bobbins, connectors, LCD TVs, compact cameras, electric tools, video cameras, microwave ovens, electric kettles, pots, vacuum cleaners, personal computers, copying machines・ Electric parts such as printer housings, motor covers, motor fans, etc .; Wall materials, decorative sheets, artificial marble materials, handrail materials, water tanks, pipes, etc .; semiconductors such as IC and LSI, and hybrid ICs and liquid crystals Equipment in contact with electronic components such as display elements and light emitting diodes, wafers, liquid crystal substrates, equipment in contact with manufacturing intermediates such as those laminated with a transparent electrode layer or protective layer, etc., and intermediate manufacturing in the manufacturing process of electronic components Equipment that comes into contact with treatment liquids such as chemicals and ultrapure water used for body treatment, such as tanks, trays, carriers, cases, wafer shippers, FOUP, FOSB, carrier tapes, separation films, chemical pipes, tubes , Valves, flow meters, filters, pumps, sampling containers, bottles, ampoules, etc. Electronic component processing equipment; microwave containers, baby bottles, instant food containers, bottles, food containers such as dishes, caps and containers, baby bottles, bottles, are useful, such as in the lid, such as a petri dish tray.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited only to these examples. In the following examples and comparative examples, parts and% are based on weight unless otherwise specified. The measurement methods for various physical properties are shown below.
(1) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)
The molecular weights of the block copolymer [1] and the block copolymer hydride [2] were measured at 38 ° C. as standard polystyrene conversion values by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent. As a measuring apparatus, HLC8020GPC manufactured by Tosoh Corporation was used.
(2) Hydrogenation rate The hydrogenation rate of the main chain, side chain, and aromatic ring of the block copolymer hydride [2] was calculated by measuring a ¹ H-NMR (in deuterated chloroform) spectrum.
(3) Alkoxysilyl group introduction amount Confirmation of the presence of the alkoxysilyl group in the modified block copolymer hydride [3] is, for example, when a methoxysilyl group is introduced, with Si-- at 1090 cm ⁻¹ in the FT-IR spectrum. Absorption bands based on OCH ₃ groups are observed, and new absorptions derived from Si—CH ₂ groups at 825 and 739 cm ⁻¹ when, for example, vinyltrimethoxysilane is used for the introduction of alkoxysilyl groups. It can be confirmed from the fact that the band is observed at a position different from 808 and 766 cm ⁻¹ of the absorption band derived from the Si—CH ₂ group of vinyltrimethoxysilane. In the ¹ H-NMR spectrum (in deuterated chloroform), an absorption band based on protons of the methoxy group was observed at 3.6 ppm. From the ratio of this peak area to the peak area of the absorption band based on protons of the entire polymer, The amount of alkoxysilyl group introduced to the block copolymer hydride [2] can be quantified.
(4) Total light transmittance The extruded sheet after contact with water was measured according to JIS K 7361.
(5) Heat resistance About the extruded sheet of the block copolymer hydride [2] and the extruded sheet after contact with water, put in a high-pressure steam sterilizer (product name “SX-700” manufactured by Tommy Seiko Co., Ltd.) After performing steam sterilization treatment under Condition 1 (121 ° C., 30 minutes) or Condition 2 (134 ° C., 20 minutes) and cooling to room temperature, changes in appearance are visually observed and dimensional changes in the MD direction (Machine Direction). : Resin flow direction) and TD direction (Transverse Direction: resin width direction).

[Reference Example 1]
(Modified block copolymer hydride [3-a])
Synthesis of block copolymer hydride [2-a] 550 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene and 0.475 part of n-dibutyl ether were added to a reactor equipped with a stirrer sufficiently purged with nitrogen. While stirring at 60 ° C., 0.62 part of n-butyllithium (15% cyclohexane solution) was added to initiate polymerization. The mixture was reacted at 60 ° C. for 60 minutes with stirring. At this point in time as measured by gas chromatography, the polymerization conversion was 99.5%.
Next, 50.0 parts of dehydrated isoprene was added and stirring was continued for 30 minutes. At this time, the polymerization conversion rate was 99.5%.
Thereafter, 25.0 parts of dehydrated styrene was further added and stirred for 60 minutes. The polymerization conversion rate at this point was almost 100%. Here, 0.5 part of isopropyl alcohol was added to stop the reaction. The obtained block copolymer [1-a] had a weight average molecular weight (Mw) of 78,000 and a molecular weight distribution (Mw / Mn) of 1.03.

  Next, the polymer solution was transferred to a pressure-resistant reactor equipped with a stirrer, and diatomaceous earth-supported nickel catalyst (product name “T-8400RL”, manufactured by Zude Chemie Catalysts) as a hydrogenation catalyst and dehydration 100 parts of cyclohexane was added and mixed. The inside of the reactor was replaced with hydrogen gas, and hydrogen was supplied while stirring the solution. A hydrogenation reaction was performed at a temperature of 190 ° C. and a pressure of 4.5 MPa for 6 hours. The weight average molecular weight (Mw) of the hydrogenated block copolymer [2-a] after the hydrogenation reaction was 78,800, and the molecular weight distribution (Mw / Mn) was 1.04.

After completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst, and then the phenol-based antioxidant pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl). ) Propionate] (product name “Irganox (registered trademark) 1010”, manufactured by BASF Japan Ltd.) 0.1 part of xylene solution in which 0.1 part was dissolved was added and dissolved.
Next, the above solution was filtered with a metal fiber filter (pore size 0.4 μm, manufactured by Nichidai) to remove minute solids, and then a cylindrical concentration dryer (product name “Contro”, manufactured by Hitachi, Ltd.) ), The solvent cyclohexane, xylene and other volatile components were removed from the solution at a temperature of 260 ° C. and a pressure of 0.001 MPa or less. The molten polymer is continuously filtered at a temperature of 260 ° C. by a polymer filter (manufactured by Fuji Filter) equipped with a stainless sintered filter having a pore diameter of 5 μm connected to a concentration dryer, and then the molten polymer is extruded into a strand form from a die. After cooling, 96 parts of pellets of block copolymer hydride [2-a] were prepared by a pelletizer. The resulting block copolymer hydride [2-a] had a weight average molecular weight (Mw) of 77,800 and a molecular weight distribution (Mw / Mn) of 1.04. The hydrogenation rate was almost 100%.

Synthesis of modified block copolymer hydride [3-a] 2.0 parts vinyltrimethoxysilane and 2,5 with respect to 100 parts pellets of the block copolymer hydride [2-a] obtained above. -0.2 part of dimethyl-2,5-di (t-butylperoxy) hexane (product name "Perhexa (registered trademark) 25B", manufactured by NOF Corporation) was added. This mixture was kneaded at a resin temperature of 200 ° C. and a residence time of 60 to 70 seconds using a twin-screw extruder (product name “TEM35B”, manufactured by Toshiba Machine Co., Ltd.), extruded into a strand shape, air-cooled, and then pelletized. 97 parts of pellets of a modified block copolymer hydride [3-a] into which an alkoxysilyl group was introduced were prepared.

After dissolving 10 parts of pellets of the obtained modified block copolymer hydride [3-a] in 100 parts of cyclohexane, the resulting mixture was poured into 400 parts of dehydrated methanol to give the modified block copolymer hydride [3-a]. After coagulation, filtration, and vacuum drying at 25 ° C., 9.5 parts of crumb of the modified block copolymer hydride [3-a] was isolated. In the FT-IR spectrum, absorption bands derived from the Si—OCH ₃ group and the Si—CH ₂ group were observed. Further, ¹ H-NMR spectrum confirmed that 1.7 parts of vinyltrimethoxysilane was bonded to 100 parts of the block copolymer hydride [2-a].

[Example 1]
0.2 parts of tetrabutyl orthotitanate was added to 100 parts of pellets of the modified block copolymer hydride [3-a] obtained in Reference Example 1. Using this mixture, a twin-screw extruder (product name “TEM37B”, manufactured by Toshiba Machine Co., Ltd.) equipped with a 300-mm wide T-die has a molten resin temperature of 200 ° C., a T-die temperature of 200 ° C., and a cast roll temperature of 80 ° C. Under the molding conditions, a sheet [S3-a] having a thickness of 1 mm and a width of 250 mm was extruded. The obtained sheet [S3-a] was cut into a length of 500 mm and collected.

  The sheet [S3-a] was cut into a 250 × 250 mm square to obtain a preform, which was brought into contact with water in a high-humidity and high-temperature tank at a temperature of 85 ° C. and a humidity of 90% RH for 24 hours. In order to remove moisture remaining in the sheet, the sheet was dried in an oven at 85 ° C. for 2 hours to obtain a sheet “S4-a”. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S4-a].

  A test piece having a size of 200 × 200 mm was cut out from the obtained sheet [S4-a] and subjected to steam sterilization treatment under conditions 1 and 2, respectively. After the steam sterilization treatment, moisture remaining in the sheet was removed by drying in an oven at 85 ° C. for 2 hours. The size of the test piece after the steam sterilization treatment was measured to evaluate the dimensional change. The measurement results are shown in Table 1.

[Comparative Example 1]
The block copolymer hydride [2-a] pellets obtained in Reference Example 1 were used, no silanol condensation catalyst was blended, the molten resin temperature was 210 ° C, the T-die temperature was 210 ° C, and the cast roll temperature was 90 ° C. A sheet [S2-a] having a thickness of 1 mm and a width of 250 mm was extruded and formed in the same manner as in Example 1 except that the molding conditions were used. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S2-a].

  A test piece having a size of 200 × 200 mm was cut out from the sheet [S2-a], and subjected to steam sterilization treatment and drying of residual moisture under the same conditions as in Example 1. The test piece after the steam sterilization treatment under condition 2 showed a clear dimensional change. The size of the test piece after the steam sterilization treatment was measured to evaluate the dimensional change. The measurement results are shown in Table 1.

[Comparative Example 2]
From the sheet [S3-a] obtained by molding the modified block copolymer hydride [3-a] blended with the silanol condensation catalyst obtained in Example 1, 200 directly without passing through the water contact step. A test piece with a size of × 200 mm was cut out and subjected to steam sterilization treatment under conditions 1 and 2, respectively. After the steam sterilization treatment, moisture remaining in the sheet was removed by drying in an oven at 85 ° C. for 2 hours. The total light transmittance and size of the test piece after the steam sterilization treatment were measured, and the dimensional change was evaluated. The measurement results are shown in Table 1.

[Reference Example 2]
(Modified block copolymer hydride [3-b])
Synthesis of block copolymer hydride [2-b] As monomers in the polymerization stage, 20.0 parts of styrene, 0.49 parts of n-butyllithium (15% cyclohexane solution), 60.0 parts of isoprene, and 20.20 parts of styrene. 96 parts of block copolymer hydride [2-b] pellets were obtained in the same manner as in Reference Example 1 except that 0 part was added to the reaction system in this order for polymerization. The resulting block copolymer hydride had a weight average molecular weight (Mw) of 97,100 and a molecular weight distribution (Mw / Mn) of 1.04. The hydrogenation rate was almost 100%.

Synthesis of modified block copolymer hydride [3-b] Except for using 2.5 parts of vinyltrimethoxysilane to 100 parts of pellets of block copolymer hydride [2-b] obtained above. Produced 96 parts of a pellet of a modified block copolymer hydride [3-b] into which an alkoxysilyl group was introduced in the same manner as in Reference Example 1.

The modified block copolymer hydride [3-b] was isolated in the same manner as in Reference Example 1 except that the pellets of the obtained modified block copolymer hydride [3-b] were used. In the FT-IR spectrum, absorption bands derived from the Si—OCH ₃ group and the Si—CH ₂ group were observed. Further, ¹ H-NMR spectrum confirmed that 2.1 parts of vinyltrimethoxysilane was bonded to 100 parts of the block copolymer hydride [2-b].

[Example 2]
A sheet [S3-b] having a thickness of 1 mm and a width of 250 mm was prepared in the same manner as in Example 1 except that 100 parts of the pellet of the modified block copolymer hydride [3-b] obtained in Reference Example 2 was used. Extruded and collected.

  Sheet [S3-b] was cut into 250 × 250 mm square to obtain a preform, which was contacted with water in the same manner as in Example 1 and dried to obtain sheet “S4-b”. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S4-b].

  A test piece having a size of 200 × 200 mm was cut out from the obtained sheet [S4-b], and steam sterilization treatment and residual moisture were dried in the same manner as in Example 1. The size of the test piece after the steam sterilization treatment was measured to evaluate the dimensional change. The measurement results are shown in Table 1.

[Comparative Example 3]
The block copolymer hydride [2-b] pellets obtained in Reference Example 2 were used, no silanol condensation catalyst was blended, the molten resin temperature was 210 ° C, the T-die temperature was 210 ° C, and the cast roll temperature was 90 ° C. A sheet [S2-b] having a thickness of 1 mm and a width of 250 mm was extruded and formed in the same manner as in Example 2 except that the molding conditions were used. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S2-b].

  A test piece having a size of 200 × 200 mm was cut out from the sheet [S2-b], and steam sterilization treatment and residual moisture were dried under the same conditions as in Example 1. The test piece after the steam sterilization treatment under condition 2 showed a clear dimensional change. The size of the test piece after the steam sterilization treatment was measured to evaluate the dimensional change. The measurement results are shown in Table 1.

[Comparative Example 4]
From the sheet [S3-b] obtained by molding the modified block copolymer hydride [3-b] blended with the silanol condensation catalyst obtained in Example 2, 200 directly without passing through the water contact step. A test piece with a size of × 200 mm was cut out and subjected to steam sterilization treatment under conditions 1 and 2, respectively. After the steam sterilization treatment, moisture remaining in the sheet was removed by drying in an oven at 85 ° C. for 2 hours. The total light transmittance and size of the test piece after the steam sterilization treatment were measured, and the dimensional change was evaluated. The measurement results are shown in Table 1.

[Reference Example 3]
(Modified block copolymer hydride [3-c])
Synthesis of block copolymer hydride [2-c] As monomers in the polymerization stage, 15.0 parts of styrene, 0.49 parts of n-butyllithium (15% cyclohexane solution), 70.0 parts of isoprene and 15. 95 parts of block copolymer hydride [2-c] pellets were obtained in the same manner as in Reference Example 1 except that 0 part was added to the reaction system in this order for polymerization. The resulting block copolymer hydride had a weight average molecular weight (Mw) of 95,700 and a molecular weight distribution (Mw / Mn) of 1.04. The hydrogenation rate was almost 100%.

-Synthesis of modified block copolymer hydride [3-c] Except for using 2.8 parts of vinyltrimethoxysilane to 100 parts of pellets of block copolymer hydride [2-c] obtained above. Produced 96 parts of a pellet of a modified block copolymer hydride [3-c] into which an alkoxysilyl group was introduced in the same manner as in Reference Example 1.

The modified block copolymer hydride [3-c] was isolated in the same manner as in Reference Example 1 except that the resulting pellet of the modified block copolymer hydride [3-c] was used. In the FT-IR spectrum, absorption bands derived from the Si—OCH ₃ group and the Si—CH ₂ group were observed. Further, ¹ H-NMR spectrum confirmed that 2.4 parts of vinyltrimethoxysilane was bonded to 100 parts of the block copolymer hydride [2-c].

[Example 3]
Example except that 100 parts of pellets of the modified block copolymer hydride [3-c] obtained in Reference Example 3 were used and the molten resin temperature was 190 ° C., the T die temperature was 190 ° C., and the cast roll temperature was 60 ° C. In the same manner as in Example 1, a sheet [S3-c] having a thickness of 1 mm and a width of 250 mm was extruded and collected.

  Sheet [S3-c] was cut into 250 × 250 mm square to obtain a preform, which was contacted with water in the same manner as in Example 1 and dried to obtain sheet “S4-c”. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S4-c].

  A test piece having a size of 200 × 200 mm was cut out from the obtained sheet [S4-c], and steam sterilization treatment and drying of residual moisture were performed in the same manner as in Example 1. The size of the test piece after the steam sterilization treatment was measured to evaluate the dimensional change. The measurement results are shown in Table 1.

[Comparative Example 5]
The block copolymer hydride [2-c] pellet obtained in Reference Example 3 was used, no silanol condensation catalyst was blended, the molten resin temperature was 200 ° C, the T-die temperature was 200 ° C, and the cast roll temperature was 70 ° C. A sheet [S2-c] having a thickness of 1 mm and a width of 250 mm was extruded and formed in the same manner as in Example 3 except that the molding conditions were used. Table 1 shows the measurement results of the total light transmittance of the obtained sheet [S2-c].

  A test piece having a size of 200 × 200 mm was cut out from the sheet [S2-c], and subjected to steam sterilization treatment and drying of residual moisture under the same conditions as in Example 1. The test piece after the steam sterilization treatment under Condition 1 showed a dimensional change. The shape of the test piece after steam sterilization under condition 2 was greatly changed, and the size of the test piece after steam sterilization could not be measured. The measurement results are shown in Table 1.

[Comparative Example 6]
From the sheet [S3-c] obtained by molding the modified block copolymer hydride [3-c] blended with the silanol condensation catalyst obtained in Example 3, 200 directly without passing through the water contact step. A test piece with a size of × 200 mm was cut out and subjected to steam sterilization treatment under conditions 1 and 2, respectively. After the steam sterilization treatment, moisture remaining in the sheet was removed by drying in an oven at 85 ° C. for 2 hours. The total light transmittance and size of the test piece after the steam sterilization treatment were measured, and the dimensional change was evaluated. The measurement results are shown in Table 1.

[Example 4]
0.2 part of tetrabutyl orthotitanate was added to 100 parts of pellets of the modified block copolymer hydride [3-b] obtained in Reference Example 2. This mixture was melted at a resin temperature of 200 ° C. and a die temperature of 200 ° C. using a twin screw extruder (product name “KZW15TW”, manufactured by Technobel) with a tube die having an outer diameter of 3.0 mm and an inner diameter of 1.5 mm. Under the molding conditions, a tube [T3-b] having an outer diameter of 3.3 mm and an inner diameter of 1.6 mm was extrusion-molded. The obtained tube [T3-b] was collected by winding it on a tube reel having a core diameter of 230 mm.

  The tube [T3-b], which is a preformed body, was contacted with water for 24 hours in a high-humidity and high-temperature tank at a temperature of 85 ° C. and a humidity of 90% RH while being wound around the tube reel. In order to remove the water | moisture content which remains in a tube, it dried in 85 degreeC oven for 2 hours, and tube "T4-b" was obtained. The obtained tube [T4-b] was transparent and the visibility of the contents was good.

  From the obtained tube [T4-b], a test tube having a length of 2 m was cut out and subjected to steam sterilization under conditions 1 and 2 in a state where the tube was wound to a diameter of 150 mm without using a core. After the steam sterilization treatment, moisture remaining in the tube was removed by drying in an oven at 85 ° C. for 2 hours. The appearance of the rolled test tube after the steam sterilization treatment was visually observed, but no abnormality was observed in transparency and shape.

[Comparative Example 7]
Implemented except that pellets of block copolymer hydride [2-b] obtained in Reference Example 2 were used, no silanol condensation catalyst was added, and the molding conditions were a molten resin temperature of 210 ° C. and a die temperature of 210 ° C. In the same manner as in Example 4, a tube [T2-b] having an outer diameter of 3.3 mm and an inner diameter of 1.6 mm was extruded. The obtained tube [T2-b] was collected by winding it on a tube reel having a core diameter of 230 mm.

  From the obtained tube [T2-b], a test tube having a length of 2 m was cut out, and in the same manner as in Example 4, without using a winding core, the tube was wound to a diameter of 150 mm. Sterilization was performed. After the steam sterilization treatment, moisture remaining in the tube was removed by drying in an oven at 85 ° C. for 2 hours. The appearance of the rolled test tube after steam sterilization was visually observed. Although the test tube subjected to the steam sterilization treatment of condition 1 was not transparent and abnormal in shape, the test tube subjected to the high temperature steam sterilization treatment of condition 2 maintained transparency, but the test tube 8 buckled sites were found.

[Comparative Example 8]
From the tube [T3-b] obtained in Example 4, a test tube having a length of 2 m was cut out directly without going through the water contact step, and the diameter was reduced to 150 mm without using a core as in Example 4. Steam sterilization was performed under conditions 1 and 2 in a wound state. After the steam sterilization treatment, moisture remaining in the tube was removed by drying in an oven at 85 ° C. for 2 hours. The appearance of the rolled test tube after steam sterilization was visually observed. Although the test tube subjected to the steam sterilization treatment of condition 1 was not transparent and abnormal in shape, the test tube subjected to the high temperature steam sterilization treatment of condition 2 maintained transparency, but the test tube 7 buckled sites were seen.

The following can be seen from the results of the examples and comparative examples.
Sheet-like and tube-like molded bodies made of a hydride of a crosslinked block copolymer are transparent, do not deform even at high temperature steam sterilization at 134 ° C., have a small dimensional change of 1% or less, and have outstanding heat resistance. It is improved (Examples 1-4).
Sheet-like and tube-like molded bodies made of the block copolymer hydride [2] have a polymer composition having a high weight fraction of the polymer block [A] mainly composed of a repeating unit derived from an aromatic vinyl compound. , Withstand steam sterilization at 121 ° C, but heat resistance is not sufficient at high temperature steam sterilization at 134 ° C, and a sheet with a large dimensional change or bending stress exceeding 1% causes buckling deformation. It does not have sufficient heat resistance. (Comparative Example 1, Comparative Example 3 and Comparative Example 7). In addition, the polymer composition having a low weight fraction of the polymer block [A] mainly composed of a repeating unit derived from an aromatic vinyl compound has a large dimensional change even at 121 ° C. by steam sterilization, and high-temperature steam sterilization at 134 ° C. Then, it deforms remarkably and is inferior in heat resistance (Comparative Example 5).
Even in the case of sheet-shaped and tube-shaped molded products obtained by blending a silanol condensation catalyst with the modified block copolymer hydride [3], if not previously contacted with water, a repeating unit derived from an aromatic vinyl compound is used. The polymer composition having a high weight fraction of the polymer block [A] as the main component can withstand steam sterilization at 121 ° C., but the heat sterilization at 134 ° C. is insufficient in heat resistance. A tube subjected to a large dimensional change or bending stress exceeding% causes buckling deformation and does not exhibit sufficient heat resistance. (Comparative Example 2, Comparative Example 4 and Comparative Example 8). In addition, the polymer composition having a low weight fraction of the polymer block [A] mainly composed of a repeating unit derived from an aromatic vinyl compound has a large dimensional change even at 121 ° C. by steam sterilization, and high-temperature steam sterilization at 134 ° C. In FIG. 3, the film is remarkably deformed and does not exhibit heat resistance (Comparative Example 6).

  The molded product obtained by the method of the present invention has excellent characteristics such as transparency and heat resistance, and also has excellent resistance to high-temperature steam sterilization treatment. It can be used for containers and pharmaceutical containers. In addition, the industrial utility value is high because it can be widely used for automobile parts, electrical parts, wire covering materials, building members, electronic parts processing equipment, etc. by utilizing heat resistance.

Claims (2)

It consists of at least two polymer blocks [A] whose main component is a repeating unit derived from an aromatic vinyl compound and at least one polymer block [B] whose main component is a repeating unit derived from a chain conjugated diene compound. When the weight fraction of the polymer block [A] and the polymer block [B] in the entire polymer is wA and wB, the ratio of wA to wB (wA: wB) is 20:80 to 65: Modified block copolymer hydrogen obtained by introducing an alkoxysilyl group into a block copolymer hydride [2] in which 90% or more of all unsaturated bonds of the block copolymer [1] is 35 A method for producing a molded article, comprising bringing a preform into contact with water from a polymer composition comprising a compound [3] and a silanol condensation catalyst. The method for producing a molded article according to claim 1, wherein the contact with water is performed under heating conditions.