JP2005068497A - Plating material, plated member, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance adhesiveness of an electroless-plated film by modifying a plating material itself. <P>SOLUTION: A plating material 4 is composed of a resin base body 3 consisting mainly of blend type ABS resin and a surface layer 2' formed on the surface of the resin base body 3 and containing much graft type ABS resin. Though the surface layer 2' is hardly degraded by ozone solution, activation by ozone solution is selectively advanced. High adhesiveness is demonstrated immediately after the plating film is deposited. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plating material used for electroless plating treatment, a plating covering member using the plating material, and a method for manufacturing the same.

  As a method for imparting conductivity or metallic luster to a resin material, electroless plating treatment is known. This electroless plating is a method in which metal ions in a solution are chemically reduced and deposited to form a metal film on the surface of the material. Unlike electroplating, which is electrolytically deposited by electric power, an insulator such as a resin is also metal. A film can be formed. In addition, the resin material on which the metal film is formed can be electroplated, and the application is expanded. For this reason, electroless plating is widely used as a method for imparting metallic luster or conductivity to resin materials used in fields such as automobile parts and home appliances.

  However, the plating film formed by the electroless plating process has a problem that it takes time until the film is formed or the adhesion of the film to the resin material is insufficient. For this reason, first, a chemical etching process is first performed on the resin material to roughen the surface, and then a process of electroless plating is generally performed.

  For example, Japanese Patent Laid-Open No. 01-092377 discloses a method in which a resin material is pretreated with ozone gas and then electroless plating is performed. According to the publication, the unsaturated bond of the resin material is cleaved by ozone gas to lower the molecular weight, and molecules having different chemical compositions are mixed on the surface, resulting in loss of smoothness and roughening. Therefore, it is described that the film formed by electroless plating firmly enters the rough surface and does not easily peel off.

  In the conventional technology described above, the resin material is roughened, and the adhesion of the plating film is enhanced by a so-called anchoring effect. However, in the roughening method, the surface smoothness of the resin material is lowered. Therefore, in order to obtain a metallic luster with a high designability, the plating film must be thickened, resulting in a problem that man-hours are increased.

  Japanese Patent Application Laid-Open No. 08-092752 describes a method in which polyolefin is used as a plating material, is roughened by etching, is contacted with ozone water, and is then treated with a cationic surfactant-containing solution. However, in the method of roughening by etching, it is necessary to use poisonous and deleterious substances such as chromic acid and sulfuric acid. Further, the problem that the surface smoothness of the resin material is low cannot be solved.

Therefore, JP 2002-309377 A discloses that after a plating material is brought into contact with a high-concentration ozone solution, it is brought into contact with a solution containing at least one of an anionic surfactant and a nonionic surfactant and an alkali component. A pretreatment method for an electroless plating material is disclosed. According to the plating material processed by this pre-processing method, since the roughening is prevented, the plating film excellent in surface smoothness and adhesiveness can be formed.
Japanese Unexamined Patent Publication No. 01-092377 JP 08-092752 JP 2002-309377

  However, even if the plating material made of ABS is pretreated with an ozone solution and then electroless plating is performed, the adhesion strength of the plating film is not improved as expected. Further, immediately after the formation of the plating film, since the adhesion strength of the plating film is low, it must be left as it is for a long time, and there is a problem that a space for leaving is required and productivity is low.

  This invention is made | formed in view of such a situation, and it aims at improving the adhesiveness of an electroless-plating film by modifying the plating raw material itself.

  The characteristics of the plating material of the present invention that solves the above-mentioned problems are that the resin base comprising a blend type ABS resin as a main component and the graft type ABS resin formed on the surface of the resin base and containing at least acrylonitrile and butadiene are more than the resin base. And including a surface layer.

  And the characteristic of the plating coating member of this invention consists in the plating raw material of this invention, and the plating film formed in the surface of the plating raw material.

  Also, one of the features of the method for producing a plating material according to the present invention is that a surface layer is formed by applying a primer containing a graft type ABS resin containing at least acrylonitrile and butadiene to the surface of a resin base composed mainly of a blend type ABS resin. Another feature of the method for producing a plating material according to the present invention is that a primer containing a graft type ABS resin containing at least acrylonitrile and butadiene is applied to the mold surface of the mold, And a molding step of forming a resin substrate from a resin mainly composed of a blend type ABS resin using a coating mold.

  Furthermore, the characteristics of the manufacturing method of the plating covering member of the present invention are the ozone solution treatment process in which the first solution containing ozone is brought into contact with the plating material of the present invention, and the electroless plating for electroless plating on the treatment material. A plating step.

  That is, according to the plating raw material and the method for producing a plating coated member of the present invention, a plating film having high adhesion strength can be formed immediately after the plating treatment by the ozone solution treatment. Therefore, according to the plated coating member of the present invention, handling such as packing and transport can be performed immediately after the formation of the plated film, so that a neglected space is not required and productivity is improved. And according to the manufacturing method of the plating raw material of this invention, the plating raw material of this invention can be manufactured easily and stably reliably.

  Conventionally, ABS resin used for automobile interior parts, decorative members, etc. uses blend type ABS resin in which acrylonitrile / styrene copolymer and butadiene rubber are mixed to require strength and toughness. It has been. A graft type ABS resin obtained by graft polymerization of polybutadiene to an acrylonitrile / styrene copolymer is not used in such a field because of insufficient toughness and insufficient impact resistance.

  Therefore, the problem described in the problem to be solved by the invention is a problem that occurs when a resin substrate mainly composed of a blend type ABS resin is used as a plating material.

  As a result of earnest research to pursue the cause of this defect, the present inventors have clarified that the butadiene rubber particles in the surface layer portion of the plating material are deteriorated by the ozone solution, and the lack of strength is the cause of the adhesion failure. . That is, as shown in FIG. 1, in the resin plating material made of blend type ABS resin, the surface butadiene rubber particles are deteriorated by the ozone solution treatment, and the strength of the surface layer is lowered, so that the adhesion strength of the plating film is lowered.

  Therefore, the present inventors have conceived that the surface layer portion of the plating material does not contain butadiene rubber particles. That is, as shown in FIG. 1, if the surface of the resin substrate made of blend type ABS resin is coated with a surface layer excellent in ozone resistance, deterioration of butadiene rubber particles due to ozone solution treatment can be prevented. it can. However, the surface layer must be activated by the ozone solution treatment and have excellent adhesion of the plating film, and the present invention has been completed by selecting such a material.

  That is, the plating material of the present invention comprises: a resin base comprising a blend type ABS resin as a main component; and a surface layer formed on the surface of the resin base and containing at least a graft type ABS resin containing at least acrylonitrile and polybutadiene. Have. Since the resin base is mainly composed of blend type ABS resin, it has sufficient strength and toughness, and can be used for automobile interior parts, decorative members and the like.

  The surface layer contains more graft type ABS resin containing at least acrylonitrile and polybutadiene than the resin substrate. Since the graft type ABS resin has higher ozone resistance than the blend type ABS resin, it hardly deteriorates even when it comes into contact with the ozone solution, but the adhesion of the plating film is selectively improved by the ozone solution treatment. Further, since the thickness of the surface layer may be on the order of several hundred nm, a slight lack of toughness of the surface layer hardly affects the physical properties of the plating material. Therefore, the resin substrate is prevented from being deteriorated by the ozone solution by the surface layer, and exhibits desired physical properties.

  As the blend type ABS resin, which is the main component of the resin substrate, those conventionally used can be used as they are. As long as the performance is not impaired, other resins such as graft type ABS resin may be contained.

  The graft ABS resin constituting the surface layer is a graft polymer containing at least acrylonitrile and polybutadiene. It is desirable to use a general graft type ABS resin obtained by graft polymerization of polybutadiene to an acrylonitrile / styrene copolymer.

  The surface layer may be composed of only a graft type ABS resin, or may contain other resins such as a blend type ABS resin. However, the amount (concentration) of the graft type ABS resin needs to be larger than the amount (concentration) of the graft type ABS resin of the resin substrate. When the amount is less than the amount (concentration) of the graft-type ABS resin on the resin substrate, the adhesion of the electroless plating film is lowered.

  The thickness of the surface layer is preferably in the range of several hundred nm to several μm. Since it is about 500 nm that is modified by the ozone solution treatment, it may be thicker than this. However, if the thickness is too thick, the toughness of the plating material is lowered, so the upper limit is preferably about several μm.

  The surface layer may be formed by laminating a film made of a graft type ABS resin on the surface of the resin substrate. However, in consideration of the number of manufacturing steps, the surface layer is formed by applying a primer containing the graft type ABS resin to the surface of the resin substrate. A primer film is preferable. Alternatively, it is desirable to apply a primer containing a graft type ABS resin to the mold surface of the mold, and mold the resin substrate from a resin mainly composed of the blend type ABS resin using the mold. If the latter is used, the smoothness of the surface layer is improved as compared with the case where the primer is directly applied to the resin substrate, so that a high surface smoothness can be obtained even after the ozone treatment. A certain plating film can be formed, and a decorative member excellent in glitter can be produced.

  And in the manufacturing method of the plating covering member of the present invention, the ozone solution processing process which makes the 1st solution containing ozone contact the plating material of the above-mentioned present invention as a processing material, and the electroless which performs electroless plating on the processing material And a plating process. In the ozone solution treatment process, when the unsaturated bond in the surface layer existing on the surface of the plating material is partially broken by the oxidation by ozone in the first solution, the C—OH bond or the C═O bond is generated and activated. Conceivable.

  In the ozone solution treatment step, the plating material is brought into contact with the first solution. As a contact method, the first solution may be sprayed on the surface of the plating material, or the plating material may be immersed in the first solution. The contact of the plating material with the first solution by dipping is preferable because ozone is less likely to separate from the first solution than the contact of the plating material with the first solution by spraying.

  The ozone concentration in the first solution has a significant effect on the activation of the plating material surface, and an activation effect can be seen from about 10 ppm. However, if the concentration is over 100 ppm, the activation effect will increase dramatically. Further, since the deterioration is preceded when the concentration is low, the ozone concentration is preferably high.

  In principle, the higher the treatment temperature in the first treatment step, the higher the reaction rate. However, the higher the temperature, the lower the solubility of ozone in the first solution, and the higher the temperature, the higher the temperature in the first solution. In order to increase the ozone concentration to 100 ppm or more, it is necessary to pressurize the treatment atmosphere to atmospheric pressure or higher, which makes the apparatus large. Accordingly, the treatment temperature is about room temperature when it is not desired to make the apparatus large.

  The time for contacting the plating material with the first solution containing ozone is preferably 4 to 20 minutes. If it is less than 4 minutes, the effect of the ozone treatment becomes difficult even if the ozone concentration is 100 ppm, and if it exceeds 20 minutes, the plating material is deteriorated.

  The first solution desirably contains a polar solvent. By including the polar solvent, the activity of ozone in the first solution can be increased, and the processing time in the first processing step can be shortened. As this polar solvent, water is particularly preferable, but alcohol solvents, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoramide and the like alone or water or alcohol It can also be used by mixing with a system solvent.

  In the electroless plating step, the treatment material treated with the ozone solution is brought into contact with the catalyst. Then, it is thought that a catalyst adsorb | sucks to the functional group formed in the surface layer.

  Then, by applying electroless plating to the plating material on which the catalyst is sufficiently adsorbed, the metal is considered to be bonded to the CO group and / or C = O group and deposited, and the plating film has excellent adhesion. Can be formed.

As the catalyst, a catalyst used in conventional electroless plating treatment such as Pd ²⁺ can be used. In order to adsorb the catalyst on the surface of the processing material, a solution in which catalyst ions are dissolved may be brought into contact with the surface of the processing material. Moreover, conditions, such as contact time and temperature, may be the same as before. The conditions for the electroless plating treatment and the metal species to be deposited are not limited, and can be performed in the same manner as in the conventional electroless plating treatment.

  It is desirable to perform an electrolytic plating treatment step in which electrolytic plating is further performed on the resin material after the electroless plating treatment step. Thereby, metallic luster can be provided and design nature improves remarkably.

  It is desirable to further perform an alkali treatment step in which a second solution containing at least an alkali component is brought into contact with the treatment material treated with the ozone solution between the ozone solution treatment step and the electroless plating step. The alkaline component has the function of solubilizing the surface of the treated material in water at the molecular level, and removes the embrittled layer on the treated material surface to expose more of the above functional groups. improves. As this alkali component, what can melt | dissolve the surface of a process raw material in a molecular level and can remove an embrittlement layer can be used, and sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. can be used.

  The second solution preferably further contains at least one of an anionic surfactant and a nonionic surfactant. This surfactant is considered to be easily adsorbed by the hydrophobic group to the functional group exposed on the surface layer of the treatment material, and can be adsorbed to most of the functional group. In the electroless plating step, when the treatment material adsorbed by the surfactant is brought into contact with the catalyst, the catalyst is considered to be adsorbed on the hydrophilic group of the surfactant adsorbed on the functional group. And, it is thought that by applying electroless plating to the treated material that the catalyst is sufficiently adsorbed, the surfactant is removed from the functional group and the metal is combined with the CO group and / or C = O group. A plating film having excellent adhesion can be formed.

  As this surfactant, one having a hydrophobic group easily adsorbed to at least one functional group consisting of C═O and C—OH is used, and at least one of an anionic surfactant and a nonionic surfactant is used. One is used. With a cationic surfactant and a neutral surfactant, it is impossible to form a plating film or it is difficult to achieve the effect. Examples of the anionic surfactant include sodium lauryl sulfate, potassium lauryl sulfate, sodium stearyl sulfate, and potassium stearyl sulfate. Examples of the nonionic surfactant include polyoxyethylene dodecyl ether.

  As the solvent of the second solution containing the surfactant and the alkali component, it is desirable to use a polar solvent, and water can be typically used. However, depending on the case, an alcohol solvent or a water-alcohol mixed solvent is used. May be. In order to bring the second solution into contact with the processing material, a method of immersing the processing material in the second solution, a method of applying the second solution on the surface of the processing material, a method of spraying the second solution on the surface of the processing material, etc. It can be carried out.

  The concentration of the surfactant in the second solution is preferably in the range of 0.01 to 10 g / L. When the concentration of the surfactant is lower than 0.01 g / L, the adhesion of the plating film is reduced. When the concentration is higher than 10 g / L, the surfactant is in an associated state on the surface of the plating material, and excess surfactant is used as an impurity. Since it remains, the adhesion of the plating film is lowered. In this case, the plating material may be washed with water to remove excess surfactant.

  Further, the concentration of the alkali component in the second solution is preferably 12 or more in terms of pH value. The effect can be obtained even if the pH value is less than 12, but the amount of the functional group to be exposed is small, so that the time for forming the plating film by a predetermined film thickness becomes long.

  The contact time between the second solution and the treatment material is not particularly limited, but is preferably 1 minute or more at room temperature. If the contact time is too short, the amount of the surfactant adsorbed on the functional group may be insufficient, and the adhesion of the plating film may be reduced. However, if the contact time is too long, the layer in which at least one functional group selected from C═O and C—OH is exposed may be dissolved and electroless plating may be difficult. About 1 to 5 minutes is sufficient. A higher temperature is desirable, and the higher the temperature, the shorter the contact time can be. However, room temperature to about 60 ° C. is sufficient.

  In the alkali treatment step, the surfactant may be adsorbed after treatment with an aqueous solution containing only an alkali component, but an embrittlement layer may be formed again until the surfactant is adsorbed. As in the present invention, it is desirable to carry out the reaction in a state where at least one of an anionic surfactant and a nonionic surfactant coexists with an alkali component.

  Moreover, it is preferable to perform an alkali treatment process after an ozone solution treatment process, but depending on the case, it is also possible to perform an ozone solution treatment process and an alkali treatment process simultaneously. In this case, a mixed solution of the first solution and the second solution is prepared, and the plating material is immersed in the mixed solution, or the mixed solution is sprayed on the surface of the plating material. In this case, since the reaction between ozone and the surface of the plating material is rate-limiting, the treatment time is determined according to the ozone concentration in the mixed solution.

  In addition, you may perform the process of washing with water and removing an alkaline component after an alkali treatment process. Since the surfactant is strongly adsorbed to the functional group, it is known that the adsorbed state is maintained without being removed by washing with water. Therefore, even if time elapses before the electroless plating process, the effectiveness is not lost.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

(Example 1)
FIG. 2 shows a method for producing a plating material used in this example.

  First, a mold 1 for forming a plate-shaped plating material is prepared, and a primer mainly composed of graft type ABS resin (“Maji Coat PTU” manufactured by Okuno Pharmaceutical Co., Ltd.) is formed on the mold surface to have a film thickness of 13 μm. The primer film 2 was formed by applying and drying.

  Next, blend type ABS resin pellets (“Psycolac” manufactured by UMGABS) were used for injection into the mold on which the primer film 2 was formed, and a resin substrate 3 was formed by an injection molding method.

  The obtained plating material 4 is composed of a resin base 3 made of a blend type ABS resin, and a surface layer 2 'made of a primer film 2 that covers the entire surface of the resin base 3 and has a graft type ABS resin as a main component. ing. The surface layer 2 ′ is excellent in surface smoothness since the mold surface of the mold 1 is transferred.

  This plating material 4 was subjected to ozone solution treatment in which it was immersed in an ozone aqueous solution containing 150 PPM ozone at room temperature for 1, 2, 4, 8, 12, 20, and 30 minutes, respectively.

  Next, a mixed aqueous solution in which NaOH (alkaline component) 50 g / L and sodium lauryl sulfate (anionic surfactant) 1 g / L are dissolved is heated to 60 ° C., and then the plating material 4 after the ozone solution treatment is applied thereto. Was immersed for 2 minutes.

  In order to activate the palladium after washing with water and drying, 0.1% by weight of palladium chloride and 5% by weight of tin chloride are dissolved in 3N aqueous hydrochloric acid and immersed in a catalyst solution heated to 50 ° C. for 3 minutes. And immersed in a 1N aqueous hydrochloric acid solution for 3 minutes. As a result, a plating material adsorbed with the catalyst was obtained.

  Thereafter, the plating material was immersed in a Ni-P chemical plating bath kept at 40 ° C. to deposit a Ni-P plating film for 10 minutes. The thickness of the deposited Ni—P plating film is 0.5 μm. Subsequently, 100 μm of copper plating was deposited on the surface of the Ni—P plating film in a copper sulfate-based Cu electroplating bath.

  After this was dried at 70 ° C. for 120 minutes, a cut reaching the plating material was made in the obtained plating film with a width of 1 cm, and the adhesion strength of the plating film was measured with a tensile tester. The measurement was performed immediately after the formation of the copper plating film. The results are shown in Table 1 and FIG. Further, the surface smoothness of the plating film was visually determined, and the results are shown in Table 1.

  The adhesion strength was measured immediately after the formation of the copper plating film, after 60 minutes and after 120 minutes for the sample subjected to the ozone solution treatment immersed in an ozone aqueous solution for 4 minutes. The standing conditions were constant temperature and humidity conditions with a relative humidity of 50% and a temperature of 70 ° C. The results are shown in Table 2.

(Example 2)
Prepare a resin substrate manufactured by injection molding from blend type ABS resin pellets (“Psycolac” made by UMGABS), and primer (“Majicoat PTU” Okuno Pharmaceutical Co., Ltd.) with graft type ABS resin as the main component on the surface. Manufactured) was applied to a film thickness of 13 μm and dried to form a surface layer.

  The resin substrate having this surface layer was used as a plating material, and after the same treatment as in Example 1, a Ni-P plating film and a copper plating film were formed in the same manner. Then, the adhesion strength of the plating film was measured in the same manner as in Example 1, and the results are shown in Tables 1 and 2. Further, the surface smoothness of the plating film was visually determined, and the results are shown in Table 1.

(Comparative example)
A resin substrate similar to that of Example 2 was prepared, and a plating material was used as it was without forming a surface layer. After performing the same processing as in Example 1 on this plating material, a Ni-P plating film and a copper plating film were formed in the same manner. And the adhesion strength of a plating film was measured like Example 1, and a result is shown in FIG. Further, the surface smoothness of the plating film was visually determined, and the results are shown in Table 1.

  <Evaluation>

  From Table 1, it can be seen that the plating films formed in Example 1 and Example 2 show higher adhesion strength than the comparative example, which has a surface layer mainly composed of graft type ABS resin. It is clear that this is the effect of doing. Moreover, the plating film formed in Example 1 and Example 2 shows the same adhesion strength, and the difference by the formation method of a surface layer is not seen. It can be seen that the adhesion strength varies depending on the treatment time of the ozone solution treatment, and the treatment time is preferably in the range of 4 to 20 minutes.

  That is, in the comparative example, since the butadiene rubber particles in the surface layer portion of the plating material are deteriorated by the ozone solution and the strength is insufficient, the adhesion strength immediately after the formation of the plating film is low. However, in the examples, the graft type ABS resin of the surface layer has higher ozone resistance than the blend type ABS resin, so that the deterioration hardly occurs even when contacting with the ozone solution, and the activation progresses as the treatment time becomes longer. I think that. Thus, in the examples, it is considered that high adhesion strength was developed even immediately after the formation of the plating film. However, if the treatment time of the ozone solution treatment exceeds 20 minutes, the surface layer is deteriorated and the adhesion strength is lowered.

  Table 2 also shows that the adhesion strength improves as the standing time after the formation of the plating film is longer. However, in the comparative example, the adhesion strength is as small as 500 g / cm even after standing for 120 minutes, whereas in the examples, the adhesion strength is as high as 1100 g / cm even immediately after the formation of the plating film. Saturated. This is also an effect due to having a surface layer mainly composed of graft type ABS resin.

  When the surface of the plating material is deteriorated by the ozone solution treatment, the generated functional groups are also reduced, and accordingly, the adhesion strength of the plating film is considered to be lowered. However, by leaving it after the formation of the plating film, the functional group is regenerated on the surface of the plating material and chemically bonded to the plating film. Therefore, it is considered that the adhesion strength improves as the standing time increases.

  That is, the longer the standing time is, the more functional groups are regenerated, but in the examples, the surface layer is less likely to be deteriorated. . In the comparative example, the adhesion strength is improved three times immediately after the plating film is formed by being left for 60 minutes, but in this example, the improvement is 1.27 times even after being left for 60 minutes, supporting this assumption. .

  Furthermore, it can be seen from Table 1 that the plating film formed in Example 1 is particularly excellent in surface smoothness, and it is preferable to produce a plating material by molding in a mold having a primer applied to the mold surface.

It is explanatory drawing which shows the effect | action of an ozone solution process. It is explanatory drawing which shows the manufacturing method of the plating raw material in one Example of this invention. It is a graph which shows the relationship between ozone solution processing time and the adhesion strength of a plating film.

Claims (10)

  A resin base comprising a blend type ABS resin as a main component, and a surface layer formed on the surface of the resin base and containing at least a graft type ABS resin containing at least acrylonitrile and polybutadiene. Plating material.   The plating material according to claim 1, wherein the surface layer is a primer film containing the graft type ABS resin.   A plating covering member comprising: the plating material according to claim 1 or 2; and a plating film formed on a surface of the plating material.   A method for producing a plating material, wherein a surface layer is formed by applying a primer containing a graft type ABS resin containing at least acrylonitrile and polybutadiene to the surface of a resin base comprising a blend type ABS resin as a main component.   A mold coating step in which a primer containing a graft type ABS resin containing at least acrylonitrile and polybutadiene is applied to the mold surface of the mold to form a coating mold, and a blend type ABS resin using the coating mold as a main component And a forming step of forming a resin substrate from the resin.   An ozone solution treatment process in which a first solution containing ozone is brought into contact with the plating material according to claim 1 or 2 to form a treatment material, and an electroless plating process for performing electroless plating on the treatment material. A method for producing a plating-coated member.   The method for producing a plating-coated member according to claim 6, wherein a treatment time of the ozone solution treatment step is 4 minutes or more and 20 minutes or less.   The plating covering member according to claim 6 or 7 which further performs an alkali treatment process which makes said processing material contact a 2nd solution containing at least an alkali ingredient between said ozone solution treatment process and said electroless plating process. Production method.   The method for producing a plating-coated member according to claim 8, wherein the second solution further contains at least one of an anionic surfactant and a nonionic surfactant.   The manufacturing method of the plating coating member in any one of Claims 6-9 which further performs the electroplating process which performs electroplating after the said electroless-plating process.

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