JP5991951B2 - Endoscopic flexible tube and endoscopic medical device - Google Patents

Description

  The present invention relates to an endoscope flexible tube and an endoscope medical device.

  An endoscope is a medical device for observing the inside of a body cavity of a patient. Since it is inserted into a body cavity and used, an organ that does not damage the organ and does not cause pain or discomfort to the patient is desired. From such a demand, a spiral tube formed by spirally winding a softly bent metal strip is adopted as the flexible tube constituting the insertion portion of the endoscope. Furthermore, the circumference | surroundings are coat | covered with flexible resin, and the device which does not give irritation | stimulation, a wound, etc. to the surfaces, such as an esophagus and an intestine, is made | formed.

  The resin layer can be formed by, for example, extrusion molding on the outer peripheral surface of a flexible tube base material in which a spiral tube is covered with a cylindrical net. At this time, in order to make it easy to insert the insertion portion into the body cavity, it is preferable that the distal end side is made flexible and soft, and the rear end side is made easy to operate. In consideration of this, a resin layer has been proposed in which a two-layer structure of inner and outer layers having different hardnesses is adopted, and the thickness ratio of the inner layer and the outer layer is changed in the axial direction of the flexible tube (patent) Reference 1). Thus, the flexibility is changed in the axial direction of the flexible tube to optimize the balance of the hardness of the entire flexible tube and meet the above demand.

Since endoscopes are used repeatedly, it is necessary to clean and disinfect them with chemicals each time they are used. Therefore, several techniques for improving the chemical resistance of endoscopes are also known. For example, Patent Document 2 describes an elastomer molded product obtained by crosslinking two or more kinds of thermoplastic polyester elastomers. By forming the resin layer of the flexible tube with this molded body, it is said that the resistance of the flexible tube to the peracetic acid aqueous solution is improved.
Patent Document 3 discloses that a resin layer of a flexible tube is formed of a resin having a structure in which a urethane polymer and an ester polymer are crosslinked. This describes that the solubility of the resin layer in chemicals such as N, N-dimethylformamide is suppressed.

JP 2011-072391 A JP 2009-183467 A JP 2002-153418 A

  However, when considering both the durability against the disinfectant and various performances required for the flexible tube, it was not known whether the techniques of the above-mentioned documents were sufficient. In view of the above points, the present invention has basic characteristics required for a flexible tube used for an endoscope-type medical device such as flexibility, elasticity, and bending durability, and various disinfectant liquids. It aims at providing the flexible tube which exhibits the favorable tolerance with respect to, and an endoscope using the same.

（式中、Ｒ^１およびＲ^２はそれぞれ独立に水素原子、炭素数１〜１２のアルキル基、または炭素数７〜３６のアラルキル基を示す。Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子または炭素数１〜１２のアルキル基を示す。Ｒ^７は水素原子、炭素数１〜１８のアルキル基、又は−ＯＲ^８を示す。Ｒ^８は水素原子又は炭素数１〜２０のアルキル基を示す。＊は結合位置を示す。）
〔８〕ヒンダードフェノール化合物が、下記式（１−１）又は（１−２）で表される〔７〕に記載の内視鏡用可撓管。

（式中、Ｒ^１及びＲ^２は式（１）と同義である。Ｌは単結合又は２価の連結基を示す。ｐは２〜４の整数を示し、Ａ^１は２〜４価の連結基を示す。Ｒ^９〜Ｒ^１２はＲ^１と同義である。Ｒ^１３は反応性有機置換基を表す。）
〔９〕前記ヒンダードアミン化合物が下記式（２−１）で表される化合物又は（２−２）で表される繰り返し単位を有する化合物である〔７〕又は〔８〕に記載の内視鏡用可撓管。

（式中、Ｒ^３〜Ｒ^７は式（２）と同義である。ｑは２以上の整数を示し、Ｄ^１は２価以上の連結基を示す。ｒは整数を表す。Ｑはｓ＋２価の連結基を表す。ｓは１又は２を表す。）
〔１０〕樹脂層が複層であり、層Ａが樹脂層の最外層を構成する〔１〕〜〔９〕のいずれか１項に記載の内視鏡用可撓管。
〔１１〕最外層以外の層Ｂがポリエステルエラストマー、ポリウレタンエラストマー、およびポリアミドエラストマーから選ばれる少なくとも１つの樹脂を含有する〔１０〕に記載の内視鏡用可撓管。
〔１２〕層Ｂの樹脂成分中のポリウレタンエラストマーの含有量が５０質量％以上である〔１１〕に記載の内視鏡用可撓管。
〔１３〕層Ｂが、ヒンダードフェノール化合物又はヒンダードアミン化合物を含有する〔１１〕または〔１２〕に記載の内視鏡用可撓管。
〔１４〕樹脂層が２層からなる〔１〕〜〔１３〕のいずれか１項に記載の内視鏡用可撓管。
〔１５〕樹脂層全体の厚みに対し、内層及び外層の厚みの割合が、内視鏡用可撓管基材の軸方向において傾斜的に変化している〔１４〕に記載の内視鏡用可撓管。
〔１６〕内層及び外層は一端における厚みの割合が、内層：外層＝５：９５〜４０：６０であり、他端における厚みの割合が、内層：外層＝９５：５〜６０：４０であり、両端間において厚みの割合が逆転している〔１５〕に記載の内視鏡用可撓管。
〔１７〕〔１〕〜〔１６〕のいずれか１項に記載の内視鏡用可撓管を具備する内視鏡型医療機器。
〔１８〕内視鏡用可撓管基材を被覆する樹脂層をなす樹脂組成物であって、ポリエステルエラストマーと、ヒンダードフェノール化合物及びヒンダードアミン化合物とを含む、内視鏡用可撓管基材被覆用樹脂組成物。
〔１９〕ヒンダードフェノール化合物に対するヒンダードアミン化合物の含有質量比が、ヒンダードフェノール化合物：ヒンダードアミン化合物＝１：１６〜１６：１である〔１８〕に記載の内視鏡用可撓管基材被覆用樹脂組成物。
〔２０〕内視鏡用可撓管基材を被覆する複層の樹脂層をなす樹脂組成物のセットであって、ポリエステルエラストマーと、ヒンダードフェノール化合物及びヒンダードアミン化合物とを含む樹脂組成物と、ポリエステルエラストマー、ポリウレタンエラストマー、およびポリアミドエラストマーから選ばれる少なくとも１つを含む樹脂組成物とを組み合わせた、内視鏡用可撓管基材被覆用樹脂組成物のセット。
〔２１〕ヒンダードフェノール化合物に対するヒンダードアミン化合物の含有質量比が、ヒンダードフェノール化合物：ヒンダードアミン化合物＝１：１６〜１６：１である〔２０〕に記載の内視鏡用可撓管基材被覆用樹脂組成物のセット。
The above object has been achieved by the following means.
[1] A flexible tube for an endoscope having a flexible tubular flexible tube base for an endoscope and a resin layer covering the flexible tube base for an endoscope ,
A flexible tube for an endoscope , in which the resin layer is a single layer or a multilayer of two or more layers, and any layer A of the resin layer includes a polyester elastomer, a hindered phenol compound, and a hindered amine compound.
[2] The flexible tube for an endoscope according to [1], wherein in the layer A, the content of the polyester elastomer in the resin component is 50% by mass or more.
[3] The flexible tube for an endoscope according to [1] or [2], wherein the layer A further contains a polyurethane elastomer or a polyamide elastomer .
[4 ] The internal view according to any one of [1] to [ 3 ], wherein the content of the hindered phenol compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin component in the resin layer. Flexible tube for mirrors .
[ 5 ] The endoscope content according to any one of [1] to [4], wherein the content of the hindered amine compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin component in the resin layer . Flexible tube.
[6] The endoscope according to any one of [1] to [5], wherein the content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. Flexible tube for mirrors.
[7] Any one of [1] to [6], wherein the hindered phenol compound has a structural moiety represented by the following formula (1) and the hindered amine compound has a structural moiety represented by the following formula (2). A flexible tube for an endoscope according to 1 .

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aralkyl group having 7 to 36 carbon atoms. R ^{3 to} R ⁶ each independently represent a hydrogen atom or a carbon atom. R ⁷ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or —OR ^8, and R ⁸ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Indicates the bonding position.)
[8] The endoscope flexible tube according to [7], wherein the hindered phenol compound is represented by the following formula (1-1) or (1-2).

(In the formula, R ¹ and R ² have the same meanings as in formula (1). L represents a single bond or a divalent linking group. P represents an integer of 2 to 4, and A ¹ represents a bivalent to tetravalent group. R ^{9 to} R ¹² have the same meanings as R ^1. R ¹³ represents a reactive organic substituent.
[9] The endoscope according to [7] or [8] , wherein the hindered amine compound is a compound represented by the following formula (2-1) or a compound having a repeating unit represented by (2-2): Flexible tube.

(Wherein R ^{3 to} R ⁷ have the same meanings as in formula (2). Q represents an integer of 2 or more, D ¹ represents a divalent or higher linking group, r represents an integer, Q represents s + 2 valence. And s represents 1 or 2.)
[10] The flexible tube for an endoscope according to any one of [1] to [9], wherein the resin layer is a multilayer and the layer A constitutes the outermost layer of the resin layer.
[11] The flexible tube for an endoscope according to [10], wherein the layer B other than the outermost layer contains at least one resin selected from a polyester elastomer, a polyurethane elastomer, and a polyamide elastomer.
[12] The flexible tube for an endoscope according to [11], wherein the content of the polyurethane elastomer in the resin component of the layer B is 50% by mass or more.
[13] The flexible tube for an endoscope according to [11] or [12], wherein the layer B contains a hindered phenol compound or a hindered amine compound.
[14] The flexible tube for an endoscope according to any one of [1] to [13], wherein the resin layer includes two layers.
[15] the whole resin layer to the thickness, for endoscope according to the ratio of inner and outer layers of the thickness has changed inclined manner in the axial direction of the flexible tube base (14) Flexible tube.
[16] The ratio of the thickness at one end of the inner layer and the outer layer is inner layer: outer layer = 5: 95-40: 60, and the ratio of the thickness at the other end is inner layer: outer layer = 95: 5-60: 40, The flexible tube for an endoscope according to [15], wherein the thickness ratio is reversed between both ends .
[17 ] An endoscope medical device comprising the endoscope flexible tube according to any one of [1] to [ 16 ].
[ 18 ] A flexible tube base material for an endoscope , comprising a polyester elastomer, a hindered phenol compound, and a hindered amine compound, which is a resin composition that covers a flexible tube base material for an endoscope. Resin composition for coating .
[19] The content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. Resin composition.
[ 20 ] A resin composition set comprising a multilayer resin layer covering a flexible tube substrate for an endoscope, the resin composition comprising a polyester elastomer, a hindered phenol compound and a hindered amine compound; A set of a resin composition for covering a flexible tube substrate for an endoscope, which is combined with a resin composition containing at least one selected from a polyester elastomer, a polyurethane elastomer, and a polyamide elastomer.
[21] The content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. A set of resin compositions.

In the present specification, when there are a plurality of substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when a plurality of substituents etc. are specified simultaneously or alternatively, It means that a substituent etc. may mutually be same or different. In addition, even when not specifically stated, when a plurality of substituents are adjacent to each other, it means that they may be connected to each other or condensed to form a ring.
In the present specification, a substituent that does not specify substitution / non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent as long as a desired effect is achieved. . This is also synonymous for compounds that do not specify substitution / non-substitution.

  The flexible tube used in the endoscope type medical device or the like of the present invention and the endoscope using the flexible tube have a resin layer covering the flexible tube having flexibility, elasticity, bending durability, etc. It has the characteristics required for endoscope use and exhibits good resistance to various disinfectants.

It is an external view which shows the structure of an electronic endoscope. It is a fragmentary sectional view showing a schematic structure of a flexible tube. It is a block diagram which shows roughly the structure of the manufacturing apparatus of the flexible tube for endoscopes. It is sectional drawing cut | disconnected by the BB line of FIG.

  A flexible tube is incorporated in the electronic endoscope according to a preferred embodiment of the present invention. Such products are widely used for medical purposes. In the example shown in FIG. 1, the electronic endoscope 2 is connected to an insertion unit 3 inserted into a body cavity, a main body operation unit 5 connected to a proximal end portion of the insertion unit 3, a processor device, and a light source device. And a universal cord 6 to be connected. The insertion portion 3 is provided with a flexible tube 3a continuously provided to the main body operation portion 5, an angle portion 3b provided continuously therewith, and an imaging device (not shown) for photographing inside the body cavity. Is comprised from the front-end | tip part 3c with which it was incorporated. The flexible tube 3a that has the most length of the insertion portion 3 has flexibility over almost the entire length thereof, and in particular, a portion to be inserted into a body cavity or the like has a more flexible structure.

(Flexible tube)
As shown in FIG. 2, the flexible tube 3a (flexible tube for an endoscope) braids a metal wire on a spiral tube 11 formed by spirally winding a metal strip 11a on the innermost side. Thus, a flexible tube base material 14 is formed by covering the cylindrical mesh body 12 and fitting the caps 13 to both ends, and the outer peripheral surface thereof is covered with the resin layer 15. The outer surface of the resin layer 15 is coated with a coat layer 16 containing, for example, fluorine having chemical resistance. Although only one layer of the spiral tube 11 is illustrated, two layers may be coaxially stacked. The resin layer 15 and the coat layer 16 are drawn thicker than the diameter of the flexible tube base material 14 in order to clearly show the layer structure.

  The resin layer 15 according to the present embodiment covers the outer peripheral surface of the flexible tube base material 14. The resin layer 15 has a two-layer configuration in which an inner layer 17 that covers the entire circumferential surface around the axis of the flexible tube substrate 14 and an outer layer 18 that covers the entire circumferential surface around the axis of the inner layer 17 are laminated. A soft resin is used as the material of the inner layer 17, and a hard resin is used as the material of the outer layer 18.

  In the present embodiment, the resin layer 15 is formed with a substantially uniform thickness in the longitudinal direction (axial direction) of the flexible tube base 14. The thickness of the resin layer 15 is, for example, 0.2 mm to 1.0 mm, and the outer diameter D of the flexible tube 3a is, for example, 11 to 14 mm. The thicknesses of the inner layer 17 and the outer layer 18 are formed such that the ratio of the thicknesses of the layers 17 and 18 to the total thickness of the resin layer 15 changes in the axial direction of the flexible tube substrate 14. Specifically, on the one end 14 a side (tip end side) of the flexible tube base 14 attached to the angle portion 3 b, the inner layer 17 is thicker than the outer layer 18 with respect to the total thickness of the resin layer 15. large. Then, the thickness of the inner layer 17 gradually decreases from the one end 14a toward the other end 14b side (base end side) attached to the main body operation unit 5, and on the other end 14b side, the thickness of the outer layer 18 is the inner layer 17 side. It is larger than the thickness.

  In both ends 14a and 14b of the present embodiment, the ratio of the thickness of the inner layer 17 and the outer layer 18 is the maximum, 9: 1 at one end 14a, and 1: 9 at the other end 14b. Between both ends 14a and 14b, the thickness ratio of the inner layer 17 and the outer layer 18 is changed to be reversed. Thereby, the flexibility of the flexible tube 3a changes in the axial direction so that a difference in hardness occurs between the one end 14a side and the other end 14b side, so that the one end 14a side is soft and the other end 14b side is hard. The inner layer and the outer layer have a thickness ratio at one end of 5:95 to 40:60 (inner layer: outer layer) and a thickness ratio at the other end of 95: 5 to 60:40 (inner layer: outer layer). It is preferable that it exists in.

  In addition, it is preferable to make the ratio of the thickness of the inner layer 17 and the outer layer 18 into the range of 5: 95-95: 5 like the said example. By setting it within this range, the extrusion amount of the thinner resin can be controlled more precisely.

  The soft resin and the hard resin used for the inner layer 17 and the outer layer 18 preferably have a difference in 100% modulus value, which is an index representing the hardness after molding, of 1 MPa or more, and more preferably 3 MPa or more. The difference in melt viscosity at a molding temperature of 150 ° C. to 300 ° C., which is an index representing the fluidity of the resin in the molten state, is preferably 2500 PaS or less. Thereby, the resin layer 15 composed of the inner layer 17 and the outer layer 18 ensures both good molding accuracy and a necessary hardness difference between the distal end side and the proximal end side.

(Flexible tube manufacturing method)
An example of a method for producing a flexible tube having a two-layer structure in which a resin layer is composed of an inner layer and an outer layer will be described below, but an embodiment in which the resin layer is one layer or three or more layers can also be produced according to the following method. .

In forming a resin layer composed of at least two layers, an inner layer and an outer layer,
(I) preparing a first resin material constituting the inner layer, and (ii) preparing a second resin material constituting the outer layer,
(Iii) It is preferable that the first resin material and the second resin material are melt-kneaded around the flexible tube base material and extruded to coat the resin layer with the resin layer.

  The manufacturing method of the flexible tube 3a (FIGS. 1 and 2) will be described with reference to FIGS. 3 and 4. In order to form the resin layer 15, it is preferable to use a continuous molding machine. The continuous molding machine 20 includes known extruding parts 21 and 22 including hoppers, screws 21a and 22a, a head part 23 for covering and molding the resin layer 15 on the outer peripheral surface of the flexible tube base 14, and a cooling part. 24, a transport unit 25 (a supply drum 28 and a take-up drum 29) for transporting the connected flexible tube base 31 to the head unit 23, and a control unit 26 for controlling them are preferably used. The head portion 23 is preferably composed of a nipple 32, a die 33, and a support 34 that fixedly supports them. As a configuration example of such a device, for example, a device described in FIGS. 3 to 5 of JP 2011-72391 A can be used.

  It is preferable to heat the inside of the die 33 to a predetermined molding temperature. The molding temperature is preferably set in the range of 150 ° C to 300 ° C. Each temperature of the soft resin 39 and the hard resin 40 can be increased by adjusting the heating temperature of the heating unit in the apparatus. In addition to this, the higher the rotational speed of each of the screws 21a and 22a, the higher the soft resin 39. And each temperature of hard resin 40 can be made still higher, and each fluidity can be raised. At this time, the forming speed of the inner layer 17 and the outer layer 18 is adjusted by changing the discharge amount of the soft resin 39 and the hard resin 40 in a molten state while keeping the conveying speed of the connected flexible tube base material 31 constant. Can do.

  The process when the resin layer 15 is formed on the connected flexible tube base material 31 by the continuous molding machine 20 will be described. When the continuous molding machine 20 performs the molding process, the molten soft resin 39 from the extruded portions 21 and 22 is used. Then, the hard resin 40 is pushed out to the head portion 23. At the same time, the transport unit 25 operates to transport the connected flexible tube base material 31 to the head unit 23. At this time, the extruding portions 21 and 22 are in a state in which the soft resin 39 and the hard resin 40 are always extruded and supplied to the head portion 23. The soft resins 39 and 22 extruded from the extruding portions 21 and 22 to the gates 35 and 36, and The hard resin 40 passes through the edges, merges, and is supplied to the molding passage 37 through the resin passage 38 in an overlapped state. Thus, a two-layered resin layer 15 is formed in which the inner layer 17 using the soft resin 39 and the outer layer 18 using the hard resin 40 are overlapped.

  The connected flexible tube base material 31 is formed by connecting a plurality of flexible tube base materials 14, and is continuously resinous with respect to the plurality of flexible tube base materials 14 while being conveyed in the molding passage 37. 15 is molded. When the resin layer 15 is molded from one end 14a side (front end side) to the other end 14b side (base end side) of one flexible tube base material, the inner layer immediately after the resin discharge by the extrusion portions 21 and 22 is started. The thickness of 17 is increased. And the ratio of the thickness of the outer layer 18 is gradually increased in the intermediate part which goes to the other end 14b side. Thereby, it is preferable to control the discharge amount of the resin so that the thickness ratio of the inclined resin layer 15 is obtained.

  Since the joint member 30 is a connection part of the two flexible tube base materials 14, the control part 26 is utilized for switching the discharge amount of the extrusion parts 21 and 22. Specifically, the control unit 26 determines the one end 14a side (distal end side) of the next flexible tube base material 14 from the thickness ratio on the other end 14b side (base end side) of one flexible tube base material 14. It is preferable to switch the discharge amounts of the extruding portions 21 and 22 so that the thickness ratio of When the resin layer 15 is molded from the one end 14a side to the other end 14b side of the next flexible tube base material 14, it is similarly extruded so that the thickness of the outer layer gradually increases from one end side to the other end side. It is preferable that the parts 21 and 22 are controlled.

  The connected flexible tube base material 31 in which the resin layer 15 has been molded to the end is removed from the continuous molding machine 20, and then the joint member 30 is removed from the flexible tube base material 14. Separated. Next, the coated film 16 is coated on the resin layer 15 with respect to the separated flexible tube base material 14, and the flexible tube 3a is completed. The completed flexible tube 3a is conveyed to the assembly process of the electronic endoscope.

(Resin layer)
The resin layer of the flexible tube of the present invention is composed of a single layer or multiple layers, and the outermost layer of the resin layer is preferably composed of layer A (a layer containing a polyester elastomer and a hindered phenol compound or a hindered amine compound). Here, the “outermost layer” of the resin layer means the resin layer when the resin layer has a single layer structure, and when the resin layer has a multilayer structure of two or more layers, the resin layer of the flexible tube. Of these, the resin layer on the most surface side is meant. However, an outer layer (such as a top coat) may be further provided as long as the effects of the present invention are achieved.
The hindered phenol compound is preferably a compound having a structural moiety represented by the following formula (1), and the hindered amine compound is preferably a compound having a structural moiety represented by the following formula (2).

-Formula (1)-
In the formula (1), ^{R 1} and ^{R 2} are hydrogen atom, an alkyl group (preferably an alkyl group having 1 to 8 carbon atoms having 1 to 12 carbon atoms, e.g., methyl group, ethyl group, n- butyl group, An isopropyl group, a sec-butyl group, a t-butyl group, a t-pentyl group, a t-hexyl group, or a t-octyl group), or an aralkyl group having 7 to 36 (preferably 7 to 30) carbon atoms. At least one of R ¹ and R ² is preferably a secondary alkyl group or a tertiary alkyl group, and at least one of R ¹ and R ² is more preferably a tertiary alkyl group. It is also preferred that R ¹ and R ² are both tertiary alkyl groups (preferably t-butyl groups).
In the above formula (1), * represents a binding site.

  The compound having a structural moiety represented by the above formula (1) is preferably a compound represented by the following formula (1-1) or (1-2).

Wherein, ^{R 1} and ^{R 2} are the same meanings as ^{R 1} and ^{R 2} in the formula (1).
L represents a single bond or a divalent linking group. L is an alkylene group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), an alkenylene group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms), or -L ¹ -C (═O) —. A group represented by O-L ² — is preferable. Here, L ¹ and L ^{2 each} represent a single bond, an alkylene group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), a carbonyl group, an oxygen atom, or a combination thereof.
p is an integer of 2 to 4, and A ¹ represents a divalent to tetravalent linking group. A ¹ is preferably a divalent to tetravalent organic group, and the organic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and further preferably 1 to 12 carbon atoms. Preferably, it is 1-10.

When p is 2 and A ¹ is a divalent organic group, A ¹ is a divalent aliphatic group (preferably an alkylene group) having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms) or 6 carbon atoms. It is preferably an arylene group having ˜22 (preferably having 6 to 14 carbon atoms).
When p is 3 and A ¹ is a trivalent linking group, A ¹ is preferably a group represented by the following formula (A). In the following formula (A), * indicates a linking site.

In the above formula (A), * represents a binding site. R ^{15 to} R ¹⁷ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms).

When p is 4 and A ¹ is a tetravalent linking group, A ¹ is preferably a quaternary carbon atom. In this case, the linking group L is preferably a group represented by —L ¹ —C (═O) —OL ² —. Here, L ¹ and L ² have the same meanings as L ¹ and L ² , respectively.

R ^{9 to} R ¹² have the same meaning as R ¹ . R ¹³ is a reactive organic substituent, preferably a vinyl group-containing group, and more preferably a (meth) allyloyl group-containing group.

-Formula (2)-
In the above formula ^(2), R 3 to R ⁶ is C 1-12 hydrogen or C (preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms) alkyl group. Examples of R ^{3 to} R ⁶ include methyl group, ethyl group, n-butyl group, isopropyl group, sec-butyl group, t-butyl group, t-pentyl group, t-hexyl group, t-octyl group and the like. Can be mentioned. R ^{3 to} R ⁶ are preferably primary (linear) alkyl groups, more preferably all of R ^{3 to} R ⁶ are primary alkyl groups (particularly preferably methyl groups).

In the formula (2), R ⁷ is a hydrogen atom, having 1 to 18 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, still more preferably 1 carbon atom). Or 2) an alkyl group or —OR ⁸ , wherein R ⁸ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms). Among them, R ⁷ is preferably a hydrogen atom because it shows higher chemical resistance.

  In the above formula (2), * represents a binding site.

  The compound having a structural moiety represented by the above formula (2) is preferably a compound represented by the following formula (2-1) or a compound having a repeating unit represented by (2-2).

In formula, R < ³ > -R < ⁷ > is synonymous with R < ³ > -R < ⁷ > in said formula (2), respectively, A preferable range is also the same. q represents an integer of 2 or more, and D ¹ represents a divalent or higher linking group. s represents 1 or 2. r represents an integer, and the range of the polymerization degree described later is preferable. Q represents an s + 2 valent linking group, and examples thereof include a group containing an imino group (NR ^N ) and a group containing a triazine linking group. R ^N represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms and piperazyl group-containing group represented by formula (2).

  The compound having a structural moiety represented by the above formula (2) is more preferably a compound represented by the following formula (2-A) to (2-C) or (2-G), or the following formula (2- D) a polymer or oligomer having a repeating unit represented by (preferably a polymer or oligomer having a repeating unit of any one of formulas (2D1) to (2D3)).

In the above formulas, R ²¹ has the same meaning as R ⁷ in formula (2), and the preferred forms are also the same.
R ²² represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms). L ²¹ represents a single bond or an alkylene group having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms). R ^N has the same meaning as in formula (2-2). n represents an integer of 1 to 20 (preferably 1 to 10).

  When the compound having the structural moiety represented by the formula (2) is a polymer or an oligomer, the number of the repeating units (degree of polymerization) is preferably 2 to 100, and more preferably 2 to 50. More preferably, it is 2-10. Moreover, there is no restriction | limiting in particular in the terminal structure of a polymer or an oligomer, For example, it can be set as a hydrogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted triazyl group.

In the resin component constituting the layer A (preferably outermost layer) of the resin layer, the content of the polyester elastomer is preferably 50% by mass or more, more preferably 55% by mass or more, and further preferably 60% by mass or more. And more preferably 65% by mass or more. Further, the content of the polyester elastomer in the resin component constituting the layer A may be 100% by mass, preferably 90% by mass or less, more preferably 80% by mass or less, and 75% by mass or less. More preferably. By setting the content of the polyester elastomer in the layer A within the above-mentioned preferable range and blending the remaining portion with a soft resin, more excellent flexibility can be imparted.
When layer A of the resin layer contains a component other than the polyester elastomer as the resin component, the remainder excluding the polyester elastomer in the resin component may contain at least one of a polyurethane elastomer and a polyamide elastomer as a softer resin. Preferably, at least a polyurethane elastomer is included. In the resin component of the layer A of the resin layer, the content of the polyurethane elastomer is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, further preferably 20% by mass or more, More preferably, it is 25 mass% or more. Moreover, it is preferable that content of the polyurethane elastomer in the resin component of the layer A of a resin layer is 50 mass% or less, More preferably, it is 40 mass% or less, More preferably, it is 35 mass% or less.

  In a more preferred embodiment of the present invention, layer A of the resin layer is preferably used as the outermost layer of the resin layer, and preferably contains both a hindered phenol compound and a hindered amine compound. By coexisting the hindered phenol compound and the hindered amine compound in the layer A of the resin layer, the resistance to the disinfectant is synergistically improved as compared with the case where each of them is contained alone.

  In a preferred embodiment of the layer A of the resin layer, the hindered phenol compound is contained in an amount of 0.01 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the resin component in the layer A of the resin layer. It is to contain. As a prescription | regulation of an upper limit side, it is preferable to contain 7 mass parts or less, and it is more preferable to contain 5 mass parts or less. About the said hindered amine compound, it is preferable to contain 0.01 mass part or more with respect to 100 mass parts of resin components, More preferably, it is 0.1 mass part or more. As a prescription | regulation of an upper limit side, it is preferable to contain 7 mass parts or less, and it is more preferable to contain 5 mass parts or less. In layer A of the resin layer, the total amount of the hindered phenol compound and the hindered amine compound is preferably 7 parts by mass or less, and 6 parts by mass or less with respect to 100 parts by mass of the resin component in layer A of the resin layer. It is more preferable that As the lower limit, the content is preferably 0.01 parts by mass or more, and more preferably 0.1 parts by mass or more.

When the resin layer is composed of multiple layers, it is preferable that at least one layer other than the layer A (preferably the outermost layer) contains a polyurethane elastomer or a polyamide elastomer (hereinafter, this layer is referred to as “layer B”). More preferably, layer B contains at least a polyurethane elastomer. The layer B preferably contains a polyurethane elastomer as a main component. In this case, the content of the polyurethane elastomer is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably in the resin component of the layer B. It is 80 mass% or more, More preferably, it is 90 mass% or more. It is also preferred that all of the resin components in layer B are polyurethane elastomers, but otherwise the remainder is preferably composed of a polyamide elastomer and / or a polyester elastomer.
In addition, the main component of the layer B may be a polyamide elastomer. For example, in the layer B containing a polyamide elastomer, the content of the polyamide elastomer may be 50% by mass or more in the resin component, or 70% by mass or more. All of the resin components in the layer B can be made of a polyamide elastomer, but if not, the remainder is preferably made of a polyurethane elastomer and / or a polyester elastomer, and more preferably made of a polyurethane elastomer.

  When used as the outermost layer, the layer B preferably contains at least one of a hindered phenol compound and a hindered amine compound. Thereby, the chemical resistance of a flexible tube can be improved more. When the layer B is used for the inner layer, it may be preferable not to include these in consideration of adhesion to the outer layer, etc. rather than chemical resistance. When layer B is used as the outermost layer, the preferred blending amounts of the hindered phenol compound and the hindered amine compound are the same as those of layer A.

ＰＥ：ポリエステルエラストマー
ＰＵ：ポリウレタンエラストマー
ＰＡ：ポリアミドエラストマー
ＨＡ：ヒンダードアミン
ＨＰ：ヒンダードフェノール
（ ）は任意要素 The flexible tube of the present invention preferably includes a two-layered resin layer composed of one inner layer and one outer layer. In this case, the inner layer is composed of layer B of the resin layer, and the outer layer is composed of layer A of the resin layer. The blending of each resin layer is preferably as follows. In this invention, it is also preferable to set it as the set of the resin composition which makes the said A layer and B layer. Here, the term “resin composition” is used to include the resin itself.

PE: Polyester elastomer PU: Polyurethane elastomer PA: Polyamide elastomer HA: Hindered amine HP: Hindered phenol () is an optional element

-Physical properties-
The molecular weight of the elastomer to be applied is not particularly limited, but a molecular weight of 10,000 to 1,000,000 is preferable and a molecular weight of 20,000 is preferable from the viewpoint of forming a suitable hard segment and drawing out a good interaction with the soft segment formed by the chain extender. ˜500,000 are more preferred, and a molecular weight of 30,000 to 300,000 is particularly preferred.
In the present invention, the molecular weight of the elastomer means a weight average molecular weight unless otherwise specified. The weight average molecular weight can be measured as a molecular weight in terms of polystyrene by GPC. At this time, GPC apparatus HLC-8220 (manufactured by Tosoh Corporation) was used, and as an eluent, chloroform was used for polyester elastomer, NMP (N-methyl-2-pyrrolidone) was used for polyurethane elastomer, and m was used for polyamide elastomer. -Cresol / chloroform (manufactured by Shonan Wako Pure Chemical Industries, Ltd.) is used, the column is G3000HXL + G2000HXL, the flow rate is 1 mL / min at 23 ° C, and detection is performed by RI.

The physical properties of the layer B (preferably the inner layer) are preferably set appropriately. For example, A hardness: JIS-K7215 is preferably 40 or more, more preferably 50 or more, and particularly preferably 60 or more. The upper limit range is preferably 98 or less, more preferably 95 or less, and particularly preferably 90 or less.
The storage elastic modulus E ′ of the layer B is preferably 1 MPa or more, more preferably 2 MPa or more, and particularly preferably 3 MPa or more. The range on the upper limit side is preferably 150 MPa or less, more preferably 100 MPa or less, and particularly preferably 50 MPa or less. The loss elastic modulus E ″ of the layer B is preferably 0.1 MPa or more, more preferably 0.3 MPa or more, and particularly preferably 0.5 MPa or more. The upper limit range is 20 MPa or less. Preferably, it is 10 MPa or less, more preferably 5 MPa or less, and the loss tangent of the layer B is preferably 0.01 or more, more preferably 0.03 or more. The upper limit side range is preferably 1 or less, more preferably 0.5 or less, and particularly preferably 0.3 or less.
In the present specification, the value relating to viscoelasticity is a value of 25 ° C. unless otherwise specified. The measuring method is based on JIS-K7244-4.

The physical properties of the layer A of the resin layer are preferably set appropriately. For example, D hardness: JIS-K7215 is preferably 20 or more, more preferably 25 or more, and particularly preferably 30 or more. The upper limit range is preferably 80 or less, more preferably 70 or less, and particularly preferably 60 or less.
The storage elastic modulus E ′ of the layer A of the resin layer is preferably 1 MPa or more, more preferably 5 MPa or more, and particularly preferably 10 MPa or more. The range on the upper limit side is preferably 1 GPa or less, more preferably 500 MPa or less, and particularly preferably 300 MPa or less. The loss elastic modulus E ″ of the layer A of the resin layer is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and particularly preferably 1 MPa or more. The upper limit range is 100 MPa or less. It is preferably 50 MPa or less, more preferably 30 MPa or less, and the loss tangent of the layer A of the resin layer is preferably 0.01 or more, and 0.03 or more. The upper limit range is preferably 1 or less, more preferably 0.5 or less, and particularly preferably 0.3 or less. .

The 100% modulus value of the layer B is preferably 0.5 MPa or more, more preferably 1.0 MPa or more, and particularly preferably 1.5 MPa or more. The upper limit range is preferably 20 MPa or less, more preferably 15 MPa or less, and particularly preferably 10 MPa or less.
The 100% modulus value of the layer A of the resin layer is preferably 1.0 MPa or more, more preferably 1.5 MPa or more, and particularly preferably 2.0 MPa or more. The range on the upper limit side is preferably 30 MPa or less, more preferably 25 MPa or less, and particularly preferably 20 MPa or less.
In this specification, the modulus value is a value of 25 ° C. unless otherwise specified. The measuring method is based on JIS-K7311.

  The resin layer is preferably soluble in 1,1,1,3,3,3-hexafluoro-2-propanol (specific solvent). Being soluble in the specific solvent means having a solubility of 5% by mass at 20 ° C. Thus, being soluble in a specific solvent has the technical significance that the resin does not have a three-dimensional (crosslinked) structure, and can be used as a resin layer for a flexible tube for an endoscopic medical device. It is preferable because it exhibits flexibility.

In the resin layer, it is preferable that the elastomer constituting the resin layer is not substantially crosslinked. Here, “not substantially crosslinked” means that the resin does not have a branched structure within a range detectable by NMR or the like, in addition to being not crosslinked.
Since the elastomer of the resin layer (especially the second layer and the outer layer) according to the present embodiment is not substantially cross-linked, the resin layer of the flexible tube for an endoscope medical device is referred to as flexibility and bending durability. It is preferable because of its performance.

[Top coat]
A top coat (coat layer) 16 is applied to the flexible tube of this embodiment. The material of the top coat is not particularly limited, and urethane paint, acrylic paint, fluorine paint, silicone paint, epoxy paint, polyester paint, and the like are applied. From the viewpoint of outstanding adhesion to the resin layer, which is an advantage of this embodiment, and excellent chemical resistance, urethane paints, acrylic paints, and fluorine paints are preferred. The top coat layer may be formed by a normal method, and a mode in which a curing agent is contained in a solution in which the above coating components are dissolved in a predetermined solvent as necessary is cured. Examples of the curing treatment include heating at 100 to 200 ° C.
The main purpose of using the top coat in this embodiment is to protect and polish the surface of the flexible tube, to impart slipperiness, and to impart chemical resistance. Therefore, it is preferable that the top coat has a high elastic modulus, a smooth surface, and excellent chemical resistance. The storage elastic modulus E ′ in the topcoat single layer is preferably 1 MPa or more, more preferably 5 MPa or more, and particularly preferably 10 MPa or more. The range on the upper limit side is preferably 1 GPa or less, more preferably 500 MPa or less, and particularly preferably 300 MPa or less. By setting the storage elastic modulus E ′ to be equal to or higher than the above lower limit value, the surface protection function as a top coat can be exhibited. Can be maintained.

In the above embodiment, the soft resin layer (layer B) is disposed on the inner layer, and the hard resin layer (layer A) is disposed on the outer layer to form a two-layer molded resin layer. A soft resin layer may be disposed on the outer layer. In the above embodiment, a two-layered outer skin layer is described as an example, but the outer skin layer may have a multilayer structure of two or more layers. Both layers do not have to be in contact with each other and other functional layers may be interposed therebetween.
In the above-described embodiment, an electronic endoscope that observes an image obtained by imaging the state of the subject using the imaging apparatus is described as an example. However, the present invention is not limited to this, and an optical image is not limited thereto. The present invention can also be applied to an endoscope that employs a guide and observes the state of a subject.

  The flexible tube according to the present invention can be widely applied not only to an endoscope application but also to an endoscope medical device. For example, it can be applied to an endoscope equipped with a clip or a wire at the tip of the endoscope, or an instrument equipped with a basket or a brush, and exhibits its excellent effect. Endoscopic medical devices include medical devices that have the above-mentioned endoscope as a basic structure, as well as remote-controlled medical devices that are flexible and can be used by being introduced into the body. It means to include medical equipment widely.

  Hereinafter, the present invention will be described in more detail through examples, but the present invention is not construed as being limited thereto.

(Example 1 and Comparative Example 1)
A resin mixture (resin mixture for outer layer and inner layer) was prepared by blending (parts by mass) described in Tables 1 and 2 below, and using a twin screw kneader (product name: KZW15-30MG) manufactured by Technobel. A melt kneading process was performed at a barrel set temperature of 210 ° C. and a screw rotation speed of 100 rpm, and the discharged molten resin strand was cooled in a water tank, and then a pellet-shaped sample was prepared with a pelletizer.

  Using the resins shown in Tables 1 and 2, they were introduced into the continuous molding machine shown in FIGS. 3 and 4 to produce a flexible tube for an endoscope. Specifically, a flexible tube base material having a diameter of 12.0 mm and a length of 120 cm was coated with the inner layer resin mixture (composition) in Table 2 and the outer layer resin mixture (composition) in Table 1 in this order. The thickness of the resin layer was 0.4 mm, and the ratio of the inner and outer layers at the front and rear ends was as shown in Table 3 below. The following tests were conducted using the obtained flexible tube. The results are shown in Table 3.

  Unless otherwise specified, the following tests were performed in an environment of 25 ° C. (normal temperature) and 50% RH.

[Peracetic acid resistance]
The resin is peeled off from the flexible tube, cut out at a size of 1 cm × 10 cm, used as a test piece, immersed in a 0.3% peracetic acid aqueous solution at 50 ° C. for 150 hours, thoroughly washed with water and then washed at 23 ° C. × 50% RH for 24 hours. After drying for a period of time, a tensile test with an elongation of 50% was performed using Tensilon.
A: No breakage in tensile test with 150% elongation A: No breakage in tensile test with 50% elongation B: No breakage in tensile test with 50% elongation, but delamination between layers C: Fracture in a tensile test with an elongation of 50%

[Hydrogen peroxide solution resistance]
The resin is peeled off from the flexible tube, cut out at a size of 1 cm × 10 cm, used as a test piece, immersed in 7.0% hydrogen peroxide at 55 ° C. for 150 hours, and the surface is washed thoroughly with water at 23 ° C. × 50% RH. After drying for 24 hours, a tensile test with an elongation of 50% was performed using Tensilon.
A: No breakage in tensile test with 150% elongation A: No breakage in tensile test with 50% elongation B: No breakage in tensile test with 50% elongation, but delamination between layers C: Fracture in a tensile test with an elongation of 50%

[Flexibility]
The position of 40 cm was fixed similarly to the position of 20 cm from the tip, and 15 mm was pushed in at a position of 30 cm, and the repulsive force after 30 seconds was measured with a force gauge.
A: Rebound resilience of 15N or less B: Over 15N, up to 25N C: Over 25N

[Resistance]
The position of 70 cm is fixed as well as the position of 50 cm from the tip, and 15 mm is pushed in at the position of 60 cm (central part of the flexible tube), and the repulsion force (A) after 0.1 second is repulsive after 30 seconds. The ratio of force (B) was measured as elasticity (%).
[Elasticity (%)] = (B) / (A) × 100
A: Elasticity is 80% or more B: 70% or more and less than 80% C: Less than 70%

[Folding durability]
The obtained flexible tube is contacted so that the half circumference part of the pulley having a diameter of 10 cm is U-shaped, and 10,000 times so that the front end part and the rear end part come to 5 cm before the pulley end. The resin was reciprocated and the state of the resin was visually observed.
A: No tearing or peeling of the resin B: Partial peeling

<Explanation of terms in the table>
Polyester elastomer (D hardness in parentheses: JIS-K7215)
PE1: Hytrel 4047 (40D) manufactured by Toray DuPont
(Weight average molecular weight: 123,000, 100% modulus 25 MPa)
PE2: Toyobo's Perprene P-40H (38D)
(Weight average molecular weight: 132,000, 100% modulus 17 MPa)
PE3: DSM Arnite EM400 (34D)
(Weight average molecular weight: 121,000, 100% modulus 12 MPa)
PE4: Toray DuPont Hytrel 3046 (27D)
(Weight average molecular weight: 128,000, 100% modulus 8.0 MPa)

Polyurethane elastomer (D hardness in parentheses: JIS-K7215)
PU1: DIC Bayer Polymer Pandex T-2190 (92A)
(Weight average molecular weight: 189,000, 100% modulus 11 MPa)
PU2: Elastollan ET1080 (80A) manufactured by BASF
(Weight average molecular weight: 124,000, 100% modulus 5.0 MPa)
PU3: Japan Milactran Milaclan E675MNAT (75A)
(Weight average molecular weight: 217,000, 100% modulus 2.9 MPa)
PU4: Pandex T-5865 (65A) manufactured by DIC Bayer Polymer
(Weight average molecular weight: 172,000, 100% modulus 2.3 MPa)

Polyamide elastomer (D hardness in parentheses: JIS-K7215)
PA1: Pevacs 2533 (75A) manufactured by Arkema
(Weight average molecular weight: 208,000, 100% modulus 4.4 MPa)
PA2: Pevacs 3533 (83A) manufactured by Arkema
(Weight average molecular weight: 171,000, 100% modulus 6.0 MPa)

Hindered phenolic compounds (HP)
HP-1: IRG1330: Irganox 1330 (manufactured by BASF)

HP-2; IRG1010: Irganox 1010 (BASF)

HP-3; GS: Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.)

Hindered amine compounds (HA)
HA-1; Tinuvin 770DF (manufactured by BASF)

HA-2; ADK STAB LA-57 (manufactured by Adeka)

HA-3; ADK STAB LA-63P (manufactured by Adeka)

HA-4; Tinuvin PA144 (manufactured by BASF)

HA-5; Chimassorb 2020FDL (manufactured by BASF)

HA-6; Chimassorb 944FDL (manufactured by BASF)

HA-7; ADK STAB LA-81 (manufactured by Adeka)

-Thermal stability-
The obtained pellet was kept at 220 ° C. for a certain time under nitrogen using TG / DTA, and the time until the weight decreased by 2% was determined.

Test No. Starting with “c” and test no. 101 to 110 are comparative examples PE: those in which polyester is not blended are described as “X” PH: those in which hindered phenol is not blended are represented as “X” PA: those in which hindered amine is not blended Indicated as "X"

  The flexible tube of the present invention and the endoscope using the flexible tube are required for endoscope-type medical device applications in which the resin layer covering the flexible tube has flexibility, elasticity, and bending durability. It can be seen that it has properties and exhibits good resistance to various disinfectants.

(Example 2)
The test No. The flexible tubes 111 and 112 were treated with peracetic acid and hydrogen peroxide without removing the coating resin. The processing conditions were the same as in Example 1. On the other hand, a flexible tube specimen was prepared in the same manner except that the inner layer B-1 was changed to B-6, and each test was performed. However, the chemical resistance was evaluated by cutting out from the flexible tube after chemical treatment. Test No. The performance of 111 and 112 was set to Fair, and it was confirmed whether the improvement (Good) or the reduction (Bad) of the performance was observed by changing the inner layer resin therefrom. The flexibility, elasticity, and bending durability were all performed using a flexible tube after the chemical treatment test. For bending durability, the number of reciprocations was 25,000.

  As a result, as shown in Table 4, the bending durability of the inner layer containing no hindered amine and hindered phenol was improved. On the other hand, the chemical resistance was the same in the outer layer, and a slight decrease was observed in the sample using B-6 in the inner layer, but it was in an acceptable range. Thus, it can be seen that by not containing the additive in the inner layer, the bending durability of the resin (particularly the adhesion between both layers) can be improved while maintaining sufficient chemical resistance.

2 Electronic endoscope (endoscope)
DESCRIPTION OF SYMBOLS 3 Insertion part 3a Flexible pipe 3b Angle part 3c Tip part 5 Main body operation part 6 Universal cord 11 Spiral pipe 11a Metal strip 12 Cylindrical mesh body 13 Base 14 Flexible pipe base material 14a Tip side 14b Base end side 15 Resin layer 16 Coat layer 17 Inner layer 18 Outer layer 20 Continuous molding machine (manufacturing equipment)
21, 22 Extrusion part 21a Screw 22a Screw 23 Head part 24 Cooling part 25 Conveying part 26 Control part 30 Joint member 31 Connection flexible pipe base material 32 Nipple 33 Die 34 Support body 35, 36 Gate 37 Molding passage 39 Soft resin 40 Hard resin

Claims (21)

An endoscope flexible tube having a flexible cylindrical flexible tube base material for endoscope and a resin layer covering the flexible tube base material for endoscope ,
The flexible tube for an endoscope, wherein the resin layer is a single layer or a multilayer of two or more layers, and any layer A of the resin layer includes a polyester elastomer, a hindered phenol compound, and a hindered amine compound. The flexible tube for an endoscope according to claim 1, wherein in the layer A, the content of the polyester elastomer in the resin component is 50% by mass or more. The flexible tube for an endoscope according to claim 1 or 2, wherein the layer A further contains a polyurethane elastomer or a polyamide elastomer. The content of the hindered phenol compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin component in the resin layer . The flexible endoscope for any one of claims 1 to 3. tube. The flexible tube for an endoscope according to any one of claims 1 to 4, wherein a content of the hindered amine compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin component in the resin layer. The content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. Endoscopic use according to any one of claims 1 to 5. Flexible tube. The said hindered phenol compound is represented by following formula (1), and has a structure site | part, The said hindered amine compound has a structure site | part represented by following formula (2), It is any one of Claims 1-6. Flexible tube for endoscope .

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aralkyl group having 7 to 36 carbon atoms. R ^{3 to} R ⁶ each independently represent a hydrogen atom or a carbon atom. R ⁷ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or —OR ^8, and R ⁸ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Indicates the bonding position.) The flexible tube for an endoscope according to claim 7, wherein the hindered phenol compound is represented by the following formula (1-1) or (1-2).

(In the formula, R ¹ and R ² have the same meanings as in formula (1). L represents a single bond or a divalent linking group. P represents an integer of 2 to 4, and A ¹ represents a bivalent to tetravalent group. R ^{9 to} R ¹² have the same meanings as R ^1. R ¹³ represents a reactive organic substituent. The flexible tube for an endoscope according to claim 7 or 8 , wherein the hindered amine compound is a compound represented by the following formula (2-1) or a compound having a repeating unit represented by (2-2).

(Wherein R ^{3 to} R ⁷ have the same meanings as in formula (2). Q represents an integer of 2 or more, D ¹ represents a divalent or higher linking group, r represents an integer, Q represents s + 2 valence. And s represents 1 or 2.) The flexible tube for an endoscope according to any one of claims 1 to 9, wherein the resin layer is a multilayer, and the layer A constitutes an outermost layer of the resin layer. The flexible tube for an endoscope according to claim 10, wherein the layer B other than the outermost layer contains at least one resin selected from a polyester elastomer, a polyurethane elastomer, and a polyamide elastomer. The flexible tube for an endoscope according to claim 11, wherein the content of the polyurethane elastomer in the resin component of the layer B is 50 mass% or more. The flexible tube for an endoscope according to claim 11 or 12, wherein the layer B contains a hindered phenol compound or a hindered amine compound. The flexible tube for an endoscope according to claim 1, wherein the resin layer includes two layers. The endoscope ratio according to claim 14, wherein a ratio of the thicknesses of the inner layer and the outer layer is changed in an inclined manner in the axial direction of the endoscope flexible tube base with respect to the thickness of the entire resin layer . Flexible tube. The ratio of the thickness of the inner layer and the outer layer at one end is inner layer: outer layer = 5: 95-40: 60, and the ratio of the thickness at the other end is inner layer: outer layer = 95: 5-60: 40. The flexible tube for an endoscope according to claim 15, wherein the ratio of the thickness is reversed. An endoscopic medical device comprising the flexible tube for an endoscope according to any one of claims 1 to 16 . A resin composition forming the resin layer covering the endoscopic flexible tube base, polyester elastomer and includes a hindered phenol compound and hindered amine compound, a flexible tube for an endoscope base coating resin Composition. The resin for covering a flexible tube base material for an endoscope according to claim 18, wherein a content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. Composition. A set of endoscopic resin composition constituting the resin layer of the multi-layer covering the flexible tube base, and a resin composition comprising a polyester elastomer, and a hindered phenol compound and hindered amine compound, a polyester elastomer, A set of a resin composition for covering a flexible tube substrate for an endoscope, which is combined with a resin composition containing at least one selected from a polyurethane elastomer and a polyamide elastomer. 21. The resin for covering a flexible tube base material for an endoscope according to claim 20, wherein a content ratio of the hindered amine compound to the hindered phenol compound is hindered phenol compound: hindered amine compound = 1: 16 to 16: 1. A set of compositions.

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