JP2006136657A - Multistep straw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a multistep straw not generating a breakage or a fracture of the straw even in a use under low-temperature conditions, capable of easily penetrating through a cover consisting of each of various materials even when its front end is not excessively sharpened, excellent in moldability and the appearance, helping render liquid left less and having biodegradability. <P>SOLUTION: The multistep straw 10 has two or more pipes having different diameters and is telescopically combined. An innermost pipe 1 innermostly positioned among the pipes has a thickness of 0.1-0.6 mm and is composed of a biodegradable resin having a flexural modulus of 1,000-1,600 MPa. An outer pipe 2 positioned on the outer side has a thickness of 0.05-0.4 mm and is composed of a biodegradable resin having a flexural modulus of 800-1,300 MPa. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multistage straw for sucking a beverage in a beverage container, and more particularly to a multistage straw for a beverage having biodegradability.

Currently, beverage products filled with various beverages in various sizes and shapes made of paper, plastic, or a composite material thereof are commercially available.
Such beverage products are often packed with a straw for sucking beverages and attached to a packaging material, and as such a straw, a product made of a synthetic resin in which an inner tube and an outer tube are stretchably combined. The two-stage straw is widely used.

In addition, a composite sheet in which various materials such as paper, aluminum foil, polyester such as polyethylene terephthalate, saponified ethylene vinyl acetate copolymer, and the like are often used for the lid of such a beverage container, and its thickness There are many different things.
Therefore, the inner tube of the two-stage straw is required to be able to pierce and penetrate the lid made of such various materials. That is, the inner tube is required to have such rigidity that it is bent at the time of piercing so that it cannot be pierced, and that the tip does not crack when piercing the lid.

As a resin used for the inner tube of such a two-stage straw, for example, a propylene homopolymer is disclosed in JP-A-60-256414.
However, when trying to pierce and penetrate the inner tube of a conventional two-stage straw through a lid made of various materials, it may be bent without piercing and not penetrate, or even if it penetrates the lid, its tip will crack. There was a case of missing or missing.

  Also, if such a two-stage straw is used in a cold region or immediately after being taken out from a low-temperature environment such as a refrigerator, the tip of the inner tube will be removed when the tip of the inner tube is pierced into the lid of the beverage container. In some cases, cracks, cracks, chips, etc. may occur in other parts. In particular, the lid using the saponified ethylene vinyl acetate copolymer was hard and the inner tube was difficult to penetrate.

In order to improve penetrability, it is conceivable to increase the rigidity by adding an inorganic filler talc. However, in order to increase the rigidity, it is necessary to add a large amount, resulting in a decrease in moldability and coloring. There was a problem that deterioration of the appearance caused by.
Further, in order to improve the penetrability, it is conceivable to increase the sharpness by making the angle of the tip surface of the inner tube very small.

However, when the tip of the inner tube is sharpened in this way, the tip of the inner tube breaks through the straw packaging when transporting or displaying a beverage container equipped with a two-stage straw. There is a possibility of jumping out, and there is a problem that when a beverage is drunk using such a two-stage straw, there is a lot of leftovers.
In order to solve these problems, Japanese Patent Application Laid-Open No. 2003-290016 proposes a multistage type straw in which a nucleating agent is blended with a polypropylene resin.

  In recent years, the disposal of plastics that are used and discarded in large quantities has become a major social problem. In order to alleviate the pollution of rivers, oceans, and soil caused by this plastic disposal, the appearance of biodegradable plastics is awaited, and biodegradable plastics are being developed.

  However, polybutylene succinate-based biodegradable resins, which are increasingly used among biodegradable resins, have properties similar to polyethylene and relatively good moldability, but when used for straws It is soft and it is necessary to cover the lack of rigidity with a thickness, which is disadvantageous in terms of cost and has not been put into practical use. In addition, polylactic acid-based biodegradable resins are not used for straws because they are hard and brittle and have poor moldability.

Japanese Patent Publication No. 2003-518998 proposes a straw having biodegradability characterized by containing a polyhydroxyalkanoate copolymer, but there is no disclosure of a multistage straw, which is necessary for a multistage straw. There is no disclosure of the presence or absence of characteristics.
Furthermore, Japanese Patent Application Laid-Open No. 2004-204143 proposes a composition comprising a biodegradable polyester resin containing 50% by mass or more of polylactic acid and a layered silicate, and a concrete pipe comprising the resin composition is proposed. A straw is illustrated as an application.

Examples of biodegradable resins other than polylactic acid include aliphatic polyesters composed of diol and dicarboxylic acid. However, this prior invention also does not disclose a multistage straw, nor does it disclose the presence or absence of characteristics necessary for the multistage straw.
As described above, there is no biodegradable resin suitable for a multistage straw and it has not been put into practical use.
JP 60-256414 A JP 2003-290016 A Special table 2003-518998 gazette JP 2004-204143 A

  Even if the present invention is used at a low temperature, the straw does not crack or crack, and the lid made of various materials can be easily penetrated without excessively increasing the sharpness of the tip. It is an object of the present invention to provide a multistage straw having excellent moldability and appearance, and having biodegradability with little leftover.

As a result of intensive studies in view of the above circumstances, the present inventors have found that the above problems can be solved by using a multistage straw having an innermost tube and an outer tube made of a specific biodegradable resin composition. The headline and the present invention were completed.
The present invention is a multistage straw shown in the following (1) to (5).
(1) In a multistage straw in which two or more tubes having different diameters are stretchably combined, among the tubes, the innermost tube located on the innermost side has a thickness of 0.1 mm to 0.6 mm, It is made of a biodegradable resin having a bending elastic modulus of 1000 to 1600 MPa, and the outer tube located on the outer side is 0.05 mm to 0.4 mm in thickness, and is made of a biodegradable resin having a bending elastic modulus of 800 to 1300 MPa. A multistage straw.

(2) In (1), the biodegradable resin is polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, poly (butylene) A succinate / terephthalate) copolymer, a poly (butylene adipate / terephthalate) copolymer, and a further copolymer or a modified product comprising these copolymers, or a mixture of two or more of 50 to A multistage straw characterized by comprising 90% by weight and 10 to 50% by weight of polylactic acid and / or a copolymer thereof.
(3) In (2), the biodegradable resin is added with 0 to 10 parts by weight of a biodegradable plasticizer with respect to 100 parts by weight of the biodegradable resin. .

  (4) In (1), the biodegradable resin forming the innermost tube is polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer Single or two selected from a polymer, a poly (butylene succinate / terephthalate) copolymer, a poly (butylene adipate / terephthalate) copolymer, and a further copolymer or a modified product made of these copolymers. The biodegradable resin comprising 50 to 90% by weight of the above mixture and 10 to 50% by weight of polylactic acid and / or a copolymer thereof, and forming the outer tube, is polybutylene succinate and poly (butylene succinate / adipate). Polymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, One or two or more kinds selected from a ri (butylene succinate / terephthalate) copolymer, a poly (butylene adipate / terephthalate) copolymer, and a further copolymer or a modified product composed of these copolymers A multistage straw comprising 70 to 100% by weight of a mixture and 0 to 30% by weight of polylactic acid and / or a copolymer thereof.

  (5) In (4), 0 to 10 parts by weight of a biodegradable plasticizer is added to 100 parts by weight of the biodegradable resin in the biodegradable resin forming the innermost tube and the outer tube. A multistage straw characterized by that.

  In the multistage straw according to the present invention, the innermost tube located on the innermost side among the tubes forming the multistage straw in which two or more tubes having different diameters are combined to expand and contract has a bending elastic modulus of 1000. It is made of biodegradable resin of ~ 1600MPa, and the outer tube located outside is made of biodegradable resin with a flexural modulus of 800 ~ 1300MPa, so even if it is used at low temperature, straw cracks and cracks occur. Without having to excessively increase the sharpness of the tip, it can easily penetrate the lid made of various materials, has excellent moldability and appearance, and has a biodegradability with little leftover. A straw can be provided.

Hereinafter, the present invention will be described in detail.
FIG. 1 shows one embodiment of a multistage straw of the present invention, which is a two-stage straw, and FIG. 1 (a) shows a state in which the inner tube is accommodated in the outer tube, FIG.1 (b) shows the state which pulled out the inner pipe | tube.

This two-stage straw 10 is a combination of an inner tube 1 and an outer tube 2 having different diameters that can be expanded and contracted. In the following description, this two-stage straw will be described as an example. In this example, the inner tube 1 is the innermost tube located on the innermost side.
In the two-stage straw 10 of this example, a first throttle portion 3 and a second throttle portion 4 are formed at both ends of the outer tube 2, and a third portion is formed between the throttle portions 3 and 4 at the tip side. The diaphragm portion 5 is formed. A stopper 6 is formed at the proximal end of the inner tube 1.

Therefore, even if the two-stage straw 10 is stretched during use, the stopper portion 6 is caught by the first throttle portion and the second throttle portion 4 so that the inner tube 1 does not come out of the outer tube 2 and is once stretched. After being extended, the stopper portion 6 is caught by the third throttle portion 5 so that it does not easily shrink.
Further, in this example, the distal end surface 7 of the inner tube is formed obliquely so as to have an angle of θ = 45 to 60 degrees with respect to the length direction of the inner tube 1.

  The inner tube 1 of the two-stage straw 10 has a thickness of 0.1 mm to 0.6 mm, preferably 0.2 mm to 0.5 mm, and is made of a biodegradable resin having a flexural modulus of 1000 to 1600 MPa. If the flexural modulus is less than 1000 MPa, the thickness of the straw must be extremely increased, and stable molding of the stopper portion 6 may be difficult. If it exceeds 1600 MPa, it becomes hard and brittle, and extrusion molding stability. Therefore, there is a risk that the dimensional accuracy of the straw diameter is lowered and the adhesion of the mating portion of the straw is lowered. If the thickness is less than 0.1 mm, the tip of the straw is easily deformed when stabbed into the beverage container, and if it exceeds 0.6 mm, it is not only disadvantageous in cost but also makes it difficult to form the stopper portion 6.

  The biodegradable resin forming the inner tube 1 includes polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer as the first component. , A poly (butylene succinate / terephthalate) copolymer, a poly (butylene adipate / terephthalate) copolymer, and a further copolymer or modified product of these copolymers, alone or in combination of two or more The mixture preferably comprises 50 to 90% by weight and 10 to 50% by weight of polylactic acid and / or a copolymer thereof as the second component. The above-mentioned “further copolymer or modified product comprising these copolymers” refers to a copolymer or modified product containing at least one of these copolymers as a constituent component.

  Polybutylene succinate as a first component, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, poly (butylene succinate / terephthalate) copolymer, When the blending amount of the poly (butylene adipate / terephthalate) copolymer and a further copolymer or a modified product composed of these copolymers, or a mixture of two or more thereof is less than 50% by weight, The rigidity of the obtained inner tube 1 is excessively increased, and the moldability is also deteriorated. If it exceeds 90% by weight, the rigidity of the inner tube 1 becomes excessively small.

  Moreover, in order to improve moldability as needed. As the third component, a biodegradable plasticizer may be blended. In this case, the blending amount is 0.1 to 100 parts by weight of the biodegradable resin composed of the first component and the second component. 10 parts by weight. When the biodegradable plasticizer exceeds 10 parts by weight, bleeding out occurs and the rigidity of the inner tube 1 is greatly reduced.

The polybutylene succinate resin, which is the first component of the biodegradable resin, has a moldability similar to that of polyolefin, and the dimensional accuracy of the innermost tube 1 and outer tube 2 of the two-stage straw 10 is improved. Although it is suitable for the required application, since the rigidity is generally low, when it is used for the inner tube 1, it is necessary to make the thickness extremely thick, and there is a possibility that it is difficult to stably form the stopper portion 6.
Therefore, by blending the polylactic acid resin as the second component so that the blend ratio is in the range of 10 to 50% by weight, the bending elastic modulus required for the inner tube can be obtained without impairing the moldability. Obtainable.

  The polylactic acid as the second component is a polymer mainly composed of L-, D- or LD-lactic acid units, and may contain other hydroxycarboxylic acid units as a small amount copolymer component. It may contain a chain extender residue. In the polylactic acid copolymer, as monomers to be copolymerized with lactic acid, optical isomers of lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2- Bifunctional aliphatic hydroxycarboxylic acids such as hydroxy-3,3dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, and lactones such as caprolactone, butyllactone, and valerolactone Can be given.

  Examples of the biodegradable plasticizer that is the third component include glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, ether ester plasticizer, and other food additives with unlimited addition. These can be used alone or in combination.

  The outer tube 2 positioned outside the two-stage straw 10 has a thickness of 0.05 mm to 0.4 mm, preferably 0.15 mm to 0.3 mm, and is made of a biodegradable resin having a flexural modulus of 800 to 1300 MPa. Become. When the thickness of the outer tube is less than 0.05 mm, when a force for stretching the inner tube is applied at the mating portion of the straw, the throttle portion 3 may be defeated by the force and the inner tube may come off. If the thickness of the outer tube is greater than 0.4 mm, when the straw is stretched, when the stopper portion of the inner tube passes through the restricting portion 5, the restricting portion 5 is difficult to spread outward, and the stretching resistance increases. In some cases, there is a risk that it cannot be stretched.

  This does not simply depend on the thickness, but also relates to the rigidity of the biodegradable resin to be used, and a biodegradable resin having a flexural modulus of 800 to 1300 MPa is preferable. If the flexural modulus is less than 800 MPa, the outer tube may become too soft, and problems such as crushing of the straw may occur. If it exceeds 1300 MPa, the resistance during stretching may increase and the adhesion to the inner tube may be increased. There is a risk that airtightness may not be obtained, and the problem that it is difficult to drink air by sucking air from the fitting portion when sucking the beverage may occur.

  The biodegradable resin used for the outer tube 2 can be selected from the same or similar biodegradable resin used for the inner tube 1, but is preferably polybutylene which is the first component of the biodegradable resin. It is preferable that the blending ratio of the succinate resin is 70 to 100% by weight and the blending ratio of the polylactic acid resin as the second component is 0 to 30% by weight. In this case, when the blending ratio of the polybutylene succinate resin is less than 70% by weight, the rigidity of the outer tube 2 to be obtained is excessively increased and the moldability is also deteriorated. Moreover, you may mix | blend the biodegradable plasticizer which is a 3rd component similarly to the case of the inner tube | pipe 1, and the compounding quantity is 0.1-10 weight part with respect to 100 weight part of biodegradable resin similarly. It is made.

  The biodegradable resin used in the present invention may be appropriately added with additives such as an antioxidant, an ultraviolet absorber, an inorganic filler, and a colorant as long as the object of the present invention is not impaired. .

  As a method for producing such a two-stage straw, the inner tube 1 and the outer tube 2 are produced from the above-described biodegradable resin using an extruder or the like. Next, the stopper portion 6 shown in FIG. 1 is formed for the inner tube 1, and the first throttle portion 3 and the third throttle portion 5 are formed for the inner tube 2. Thereafter, after the inner tube 1 is inserted into the outer tube 2, the second throttle portion 4 is formed in the outer tube 2. As a result, it is possible to obtain a two-stage straw 10 that does not come out of the inner tube 1 from the outer tube 2 when stretched and that does not easily shrink after being stretched.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.
Example 1
A biodegradable resin composition (bending elastic modulus: 1020 MPa) in which 80% by weight of polybutylene succinate resin and 20% by weight of polylactic acid are mixed in the innermost tube and the same biodegradable resin composition is used in the outer tube. Then, raw straw tubes having respective thicknesses of 0.35 mm, 0.25 mm, outer diameters of 4.6 mm, and 6.0 mm were formed to form a two-stage straw. The angle of the straw tip of the innermost tube was 60 °.

(Example 2)
A biodegradable resin composition (bending elastic modulus 1500 MPa) in which 60% by weight of polybutylene succinate resin, 40% by weight of polylactic acid and 3 parts by weight of glycerin fatty acid ester are mixed is used for the innermost tube, and polybutylene succin is used for the outer tube. A biodegradable resin composition (bending elastic modulus: 1020 MPa) in which 80% by weight of a nate resin, 20% by weight of polylactic acid and 3 parts by weight of glycerin fatty acid ester are mixed, each having a thickness of 0.30 mm, 0.25 mm, Straw pipes having outer diameters of 4.6 mm and 6.0 mm were molded to form a two-stage straw. The angle of the straw tip of the innermost tube was 60 °.

(Example 3)
A biodegradable resin composition (bending elastic modulus 1260 MPa) in which 70% by weight of polybutylene succinate resin and 30% by weight of polylactic acid are mixed in the innermost tube and poly (butylene succinate / adipate) co-polymerized in the outer tube A biodegradable resin composition (bending elastic modulus 850 MPa) in which 80% by weight of the coalescence and 20% by weight of polylactic acid are mixed is used. The thicknesses are 0.30 mm, 0.25 mm, the outer diameter is 4.6 mm, 6 A 0.0 mm straw raw tube was formed to form a two-stage straw. The angle of the straw end of the innermost tube was 60 °.

(Comparative Example 1)
100% by weight of polybutylene succinate resin (bending elastic modulus 530 MPa) is used for the innermost tube and the outer tube, and the thicknesses of the straws are 0.35 mm, 0.25 mm, outer diameters are 4.6 mm, 6.0 mm, respectively. The original tube was molded to form a two-stage straw. The angle of the straw tip of the innermost tube was 60 °.

(Comparative Example 2)
100% by weight of polylactic acid (bending elastic modulus 3470 MPa) is used for the innermost tube and the outer tube, and a straw raw tube having a thickness of 0.35 mm, 0.25 mm, an outer diameter of 4.6 mm, and 6.0 mm is used. Attempts were made to form a two-stage straw, but since the stable drawability could not be obtained because the drawn part of the outer tube could not be formed, the performance evaluation as a two-stage straw was abandoned.

The flexural modulus of the various resins was measured as follows.
Each resin was blended with a tumbler and extruded at a resin temperature of 220 ° C. to obtain a raw straw tube. The straw raw tube was cut to a length of several mm and then press-molded to produce a resin plate having a thickness of 4 mm. As the press molding conditions, the first stage molding temperature 210 ° C., the preheating time 4 minutes 30 seconds, the degassing 30 seconds, the pressurization 1 minute (18 MPa), the second stage molding temperature 100 ° C., the pressurization 5 minutes (18 MPa), The test was carried out with cooling at 25 ° C. and pressure of 3 minutes (18 MPa).

  The obtained resin plate was cut to a width of 12 mm and then processed to a width of 10 mm with a damper to obtain a test specimen for measuring a flexural modulus. Using this test piece, the flexural modulus was measured according to JIS K 7171. The measurement conditions were such that the fulcrum distance L was 64 mm, the test speed was 2 mm / min, the indenter radius R1 was 5.0 mm, and the support base radius R2 was 5.0 mm. In addition, using seven test pieces, a value obtained by averaging five points excluding the maximum and minimum values among the seven measured values was defined as a flexural modulus.

The two-stage straws obtained in these examples and comparative examples were evaluated for (1) low temperature impact resistance and (2) film penetration.
The physical property measuring method is as follows.
(1) Low temperature impact resistance Immediately after being left at a predetermined temperature for 24 hours or longer (within 10 seconds), placed on a pedestal using a DuPont impact tester (manufactured by Toyo Seiki) at a measurement ambient temperature of 23 ° C. An iron plate having a thickness of about 3 mm was placed on the straw, and a weight of 200 g was dropped from a height of 50 cm, and the presence or absence of breakage of the straw was visually observed. Such an impact test was performed 10 times, and the number of cracks was measured.

(2) Film penetrability An unstretched film having a thickness of 60 μm made of high-density polyethylene having a density of 0.958 g / cm ³ was prepared, and the film was sandwiched between two disks and firmly fixed. A hole having a diameter of 30 mm is formed in the two disks, and the film is exposed in the hole.
The film in this state was pierced vertically with an extruded product for an inner tube of a two-stage straw having an angle of the front end surface of 60 ° and attempted to penetrate. The speed (penetration speed) for piercing the extruded product was 10 m / min, and the indentation depth was 50 mm. The test is performed on 10 extrusion molded articles. For example, when 10 out of 10 penetrates, it is written as “10/10” in the table, and when 1 out of 10 penetrates, “1 / 10 ”.
These results are shown in Table 1.

In Table 1,
PBS of the first component indicates polybutylene succinate (GSPla AZ91T manufactured by Mitsubishi Chemical Corporation), and PBSA indicates polybutylene succinate adipate (# 3000 manufactured by Showa Polymer Co., Ltd.).
Also, LACEA H400 manufactured by Mitsui Chemicals was used as the second component polylactic acid. Furthermore, as described above, glycerin fatty acid ester was used as the third component biodegradable plasticizer.

  From the results shown in Table 1, the two-stage straw of the present invention has high low temperature impact resistance despite the use of a biodegradable resin, such as straw cracks and cracks even at low temperatures. It can be seen that there is no occurrence. Further, it can be seen that the penetrability is excellent, and the lid made of various materials can be easily penetrated without excessively increasing the sharpness of the tip.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an embodiment of a multistage straw according to the present invention, wherein (a) an inner tube is housed in an outer tube, and (b) an expanded state.

Explanation of symbols

1 ... Inner pipe (innermost pipe) 2 ... Outer pipe 10 ... Two-stage straw

Claims (5)

  In a multistage straw in which two or more tubes having different diameters are combined so as to be stretchable, among the tubes, the innermost tube located on the innermost side has a thickness of 0.1 mm to 0.6 mm, and a bending elastic modulus A multi-stage comprising a biodegradable resin of 1000 to 1600 MPa, and an outer tube located on the outer side having a thickness of 0.05 mm to 0.4 mm and a biodegradable resin having a flexural modulus of 800 to 1300 MPa. Expression straw.   The biodegradable resin is polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, poly (butylene succinate / terephthalate) copolymer , A poly (butylene adipate / terephthalate) copolymer, and a further copolymer or a modified product made of these copolymers, alone or a mixture of two or more thereof, 50 to 90% by weight, polylactic acid and / or The multi-stage straw according to claim 1, comprising 10 to 50% by weight of the copolymer.   The multistage straw according to claim 2, wherein 0.1 to 10 parts by weight of a biodegradable plasticizer is added to 100 parts by weight of the biodegradable resin. The biodegradable resin forming the innermost tube is polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, poly (butylene succinate / Terephthalate) copolymer, poly (butylene adipate / terephthalate) copolymer, and further copolymers or modified products made of these copolymers, either alone or as a mixture of two or more, 50 to 90% by weight , Consisting of 10-50% by weight of polylactic acid and / or copolymer thereof,
The biodegradable resin forming the outer tube is polybutylene succinate, poly (butylene succinate / adipate) copolymer, polyethylene succinate, poly (butylene succinate / carbonate) copolymer, poly (butylene succinate / terephthalate) ) A copolymer, a poly (butylene adipate / terephthalate) copolymer, and a further copolymer or a modified product composed of these copolymers, alone or a mixture of two or more thereof, 70 to 100% by weight, 2. A multistage straw according to claim 1, comprising 0-30% by weight of polylactic acid and / or a copolymer thereof. The biodegradable resin forming the innermost tube and the outer tube is characterized in that 0.1 to 10 parts by weight of a biodegradable plasticizer is added to 100 parts by weight of the biodegradable resin. Item 5. The multistage straw according to item 4.

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