Metal tube and method for manufacturing the same

Abstract

To achieve a metal tube capable of sealing the tube even when filled with a material of relatively high viscosity.SOLUTION: A metal tube (1) includes: a body (2) which is filled with a moisture curable resin composition; a discharge port (32) provided on one end of the body (2) and capable of discharging contents; and a folding seal portion (4) provided on the other end and folded at multiple stages and sealed. An adhesive agent is coated on an inner surface of the folding seal portion (4).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a metal tube and a method for manufacturing the same. [Background technology]

[0002] Aluminum tube containers can be produced at low cost and have excellent gas barrier and light blocking properties, and therefore are widely used as containers for moisture-curing resins such as adhesives and sealants.

[0003] For example, Patent Document 1 discloses an aluminum tube filled with a moisture-curing resin used as an adhesive, etc. The aluminum tube has a discharge port at one end and the opposite end is folded and sealed.

[0004] Generally, in such aluminum tubes, the low-viscosity resin filled in the aluminum tube seeps out into the bent and sealed portion, and the resin hardens due to external moisture, thereby reducing the effect of moisture on most of the resin inside the aluminum tube. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 09-272551 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the present inventors have found a problem that when a highly viscous substance is filled inside a conventional metal tube such as that described in Patent Document 1, the tube is not sufficiently sealed by folding and sealing alone.

[0007] An object of one aspect of the present invention is to provide a metal tube and a manufacturing method thereof that can seal the tube even when filled with a substance having a relatively high viscosity. [Means for solving the problem]

[0008] The present inventors conducted extensive research to solve the above problems and have now completed the present invention.

[0009] That is, a metal tube according to one embodiment of the present invention is a metal tube filled with a moisture-curable resin composition, the metal tube comprising: a body portion filled with the moisture-curable resin composition; an outlet provided at one end of the body portion through which the contents can be discharged; and a folded and sealed portion provided at an end of the body portion opposite the one end, the folded and sealed portion being folded and sealed in multiple stages, an adhesive is applied to the inner surface of the folded and sealed portion, and the moisture-curable resin composition is adjusted to have a viscosity of 200 PaS or more and 800 PaS or less at 23°C.

[0010] A method for producing a metal tube according to one embodiment of the present invention is a method for producing a metal tube filled with a moisture-curable resin composition, and includes a coating step of coating an adhesive on the inner surface of an end of a body portion of the metal tube, a drying step of drying a solvent contained in the adhesive, a filling step of filling the body portion with the moisture-curable resin composition, and a folding step of folding the end portion into multiple stages, in which the inner diameter of the body portion is A, the distance from the end of the end portion to the portion filled with the moisture-curable resin composition is B, and the coating width of the adhesive in the longitudinal direction of the metal tube is C, and in the filling step, the moisture-curable resin composition is filled so that 1.6≦B / A≦2.0 and B>C are satisfied. Effect of the Invention

[0011] According to one aspect of the present invention, even if the substance filled inside the metal tube is a moisture-curable resin composition having a relatively high viscosity, the metal tube can be sealed. [Brief description of the drawings]

[0012] [Figure 1]4 is a plan view showing a state in which the other end side of the metal tube according to the embodiment of the present invention is folded. FIG. [Diagram 2] FIG. 4 is a partial cross-sectional view showing a metal tube with the other end side not folded. [Diagram 3] FIG. 2 is an enlarged partial cross-sectional view of the vicinity of the discharge portion of the metal tube. [Figure 4] FIG. 2 is a diagram showing the positional relationship between a portion filled with a moisture-curable resin composition, a coating portion, and a folded and sealed portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] [Embodiment 1] <Metal tube configuration> Fig. 1 is a plan view showing a state in which the other end side of a metal tube 1 according to an embodiment of the present invention is folded. Fig. 2 is a partial cross-sectional view showing a state in which the other end side of the metal tube 1 is not folded. In Fig. 2, the discharge part 30 is not covered by the cap 3 and is exposed. Fig. 3 is a partial cross-sectional view of the metal tube 1 showing the closing part 34.

[0015] As shown in FIG. 1 and FIG. 2, the metal tube 1 includes a body 2 filled with a moisture-curable resin composition, a discharge part 30 provided at one end of the body 2 and capable of discharging the contents, a cap 3 covering the discharge part 30, and a folded seal part 4. In this embodiment, the side where the discharge part 30 is formed is referred to as one end side, and the side where the folded seal part 4 of the metal tube 1 is formed is referred to as the other end side. The folded seal part 4 is formed by folding and sealing the other end side of the body 2 in multiple stages. The body 2 is made of a flexible metal material, preferably aluminum. The thickness of the metal film forming the body 2 may be, for example, 0.05 mm or more and 0.20 mm or less.

[0016] 3, the metal tube 1 has a blocking portion 34 that blocks the discharge portion 30 in a breakable manner. The blocking portion 34 is made of a flexible metal material, preferably aluminum, and can be broken by inserting a protrusion into the discharge portion 30. When the blocking portion 34 is broken, the moisture-curable resin composition filled in the body portion 2 can be discharged to the outside.

[0017] (Application part) As shown in Fig. 2, the discharge part 30 is composed of a male thread part 31, a discharge port 32, and a discharge passage 33. The part indicated by the reference numeral 41 is a part in which an adhesive is applied to the inner surface of the folded sealed part 4 in an unfolded state, and this part is referred to as the coating part 41. In Fig. 2, the coating part 41 is shown by shading. The adhesive may be any one of adhesives selected from urethane-based, acrylic-based, epoxy-based, and silicone-based adhesives.

[0018] (Technical significance of applying adhesive) The moisture-curable resin composition filled in the metal tube 1 is a resin composition that forms a cured product such as a coating film after being discharged, and contains a curable liquid resin. The moisture-curable resin composition has a viscosity of 200 PaS or more and 800 PaS or less at 23°C. The moisture-curable resin composition may also have a peel strength of 1 N / cm or less in a 180° peel test at 23°C.

[0019] Conventionally, metal tubes are sometimes filled with moisture-curing substances that have a viscosity of less than about 100 PaS at room temperature (about 23°C). When such substances are filled into metal tubes, a small amount of the contents seeps out into the folded and sealed portion, and the substance hardens, firmly bonding the folded and sealed portion. This seals the metal tube and reduces the effect of moisture in the air on the substance inside the metal tube.

[0020] However, when the moisture-curable resin composition filled in the metal tube 1 is a moisture-curable resin composition having a relatively high viscosity of about 200 PaS to 800 PaS at room temperature as described above, the amount of moisture-curable resin composition seeping out to the folded seal portion 4 is small. Furthermore, in order to ensure repairability that allows adhesion and peeling, the adhesive strength of the moisture-curable resin composition is set relatively low, with a peel strength of 1 N / cm or less in a 180° peel test at 23°C. Therefore, the inventor of the present invention found that there is a high possibility that the adhesive strength of the moisture-curable resin composition itself is not sufficient to bond the folded seal portion 4. If the folded seal portion 4 is not sufficiently bonded, moisture in the air may affect the moisture-curable resin composition filled inside, causing the composition to harden, or when the metal tube 1 is used, problems such as the composition leaking out of the folded seal portion 4 may occur.

[0021] In order to solve these problems, the inventors of the present invention have found the technical idea of ​​applying an adhesive to the inner surface of the application part 41. By applying an adhesive to the inner surface of the application part 41, the application part 41 is sufficiently adhered, and the metal tube 1 is sealed. This reduces the effect of moisture in the air on the material filled in the metal tube 1, even if the material is a moisture-curable resin composition having a relatively high viscosity and a relatively low adhesive strength. In addition, when the metal tube 1 is used, the possibility of the composition inside leaking out from the folded seal part 4 can be reduced.

[0022] (Details of Moisture-Curable Resin Composition) The moisture-curable resin composition filled in the metal tube 1 contains a curable liquid resin as a moisture-curable resin. The moisture-curable resin is one or more resins selected from modified silicone resins, acrylic resins, silicone resins, and urethane resins. The details of the curable liquid resin will be described later.

[0023] The moisture-curable resin composition may contain various additives, such as a curing catalyst for curing the curable liquid resin, an initiator, a heat aging inhibitor, a plasticizer, an extender, a thixotropy imparting agent, a storage stabilizer, a dehydrating agent, a coupling agent, an ultraviolet absorber, a flame retardant, an electromagnetic wave absorber, a filler, and a solvent, as appropriate depending on the application.

[0024] The moisture-curable resin composition may be a thermally conductive resin composition prepared to contain at least a moisture-curable resin and a thermally conductive filler. When the moisture-curable resin composition is used for applications such as application to the surface of an electronic device, a substrate, or a heating element to form a coating film, it is preferable that the moisture-curable resin composition further contains a thermally conductive filler. As the thermally conductive filler, one or more thermally conductive fillers selected from aluminum, aluminum hydroxide, aluminum oxide, aluminum nitride, boron nitride, silicon carbide, graphene particles, graphene oxide particles, and calcium carbonate may be used. Details of the thermally conductive filler will be described later.

[0025] The moisture-curable resin composition contains a thermally conductive filler, which improves the thermal conductivity. Therefore, when the moisture-curable resin composition is applied between two objects, for example, between a CPU and a coolant, it can function as a thermally conductive material that more efficiently transfers heat from the CPU to the coolant. The moisture-curable resin composition containing a thermally conductive filler is more preferably a resin composition having a thermal conductivity of 0.5 W / (m·K) or more of the cured product, more preferably a resin composition having a thermal conductivity of 0.8 W / (m·K) or more, and particularly preferably a resin composition having a thermal conductivity of 1.0 W / (m·K) or more. As a result, when the moisture-curable resin composition is applied to the surface of an electronic device or the like to form a coating film, the coating film can efficiently dissipate heat generated in the electronic device or the like. In this specification, a moisture-curable resin composition having a thermal conductivity of 0.5 W / (m·K) or more of the cured product may be referred to as a thermally conductive curable resin composition.

[0026] (curable liquid resin) The curable liquid resin contained in the moisture-curable resin composition is a liquid resin that has a reactive group in the molecule and can be cured by the reaction of the reactive group. Specific examples of the curable liquid resin include curable acrylic resins such as curable methacrylic resins, curable polyether resins such as curable polypropylene oxide resins, curable polyolefin resins such as curable polyisobutylene resins, and silicone resins. Specific examples of the reactive group include reactive functional groups such as epoxy groups, hydrolyzable silyl groups, vinyl groups, acryloyl groups, SiH groups, urethane groups, carbodiimide groups, or a combination of a carboxylic acid anhydride group and an amino group.

[0027] Among the curable liquid resins, silanol condensation reaction type curable liquid resins are more preferable. Among the curable liquid resins, it is preferable to use a curable acrylic resin or a curable polypropylene oxide resin, because there is little problem of contamination in electronic devices due to low molecular weight siloxane, heat resistance is excellent, and adhesive strength can be optimally controlled. As the curable acrylic resin, various known reactive acrylic resins can be used. Among these, it is preferable to use an acrylic oligomer having a reactive group at the molecular end. As an example of such a curable acrylic resin, Kaneka XMAP manufactured by Kaneka Corporation is known. As the curable polypropylene oxide resin, various known reactive polypropylene oxide resins can be used. As an example of such a reactive polypropylene oxide resin, Kaneka MS Polymer manufactured by Kaneka Corporation is known. Two or more types of curable liquid resins can be used in combination.

[0028] (Thermal conductive filler) Examples of the thermally conductive filler used in the thermally conductive curable resin composition (and its cured product) include carbon compounds such as graphite and diamond; metal oxides such as aluminum oxide, magnesium oxide, beryllium oxide, titanium oxide, zirconium oxide, and zinc oxide; metal nitrides such as boron nitride, aluminum nitride, and silicon nitride; metal carbides such as boron carbide, aluminum carbide, and silicon carbide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; metal carbonates such as magnesium carbonate and calcium carbonate; crystalline silica; baked organic polymers such as baked acrylonitrile polymers, baked furan resins, baked cresol resins, baked polyvinyl chloride, baked sugar, and baked charcoal; composite ferrites with Zn ferrite; Fe-Al-Si ternary alloys; metal powders; and the like. Among these, aluminum hydroxide, aluminum oxide, zinc oxide, magnesium hydroxide, and calcium carbonate are more preferable in terms of availability, filling property, and insulation.

[0029] In addition, since the thermally conductive filler has improved dispersibility in the curable liquid resin, it is also possible to use fillers whose surface has been treated with a silane coupling agent (vinyl silane, epoxy silane, (meth)acrylic silane, isocyanato silane, chlorosilane, amino silane, etc.), a titanate coupling agent (alkoxy titanate, amino titanate, etc.), or a fatty acid (saturated fatty acid such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, etc.; unsaturated fatty acid such as sorbic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, etc.), a resin acid (abietic acid, pimaric acid, levopimaric acid, neoapitic acid, palustric acid, dehydroabietic acid, isopimaric acid, sandaracopimaric acid, columic acid, secodehydroabietic acid, dihydroabietic acid, etc.), etc.

[0030] The amount of the thermally conductive filler used is preferably an amount in which the volume ratio (volume %) of the thermally conductive filler in the moisture curable resin composition is 25% by volume or more, since the thermal conductivity of the cured product obtained from the moisture curable resin composition can be increased. If the amount of the thermally conductive filler used is less than 25% by volume, the thermal conductivity of the cured product tends to be insufficient. If a higher thermal conductivity is desired, the amount of the thermally conductive filler used is more preferably 30% by volume or more, even more preferably 40% by volume or more, and particularly preferably 50% by volume or more. In addition, the amount of the thermally conductive filler used is preferably 90% by volume or less. If the amount of the thermally conductive filler used is more than 90% by volume, the viscosity of the thermally conductive curable resin composition before curing may become too high.

[0031] Here, the volume fraction (vol %) of the thermally conductive filler is a value calculated from the weight fraction and specific gravity of the curable liquid resin component (moisture-curable resin composition excluding the thermally conductive filler) and the thermally conductive filler, and is calculated by the following formula (1). In formula (1), the curable liquid resin component is simply referred to as the "resin component," and the thermally conductive filler is simply referred to as the "filler."

[0032] Volume fraction of filler (volume %) = (weight fraction of filler / specific gravity of filler) ÷ [(weight fraction of resin content / specific gravity of resin content) + (weight fraction of filler / specific gravity of filler)] × 100 ... (1).

[0033] As a method for increasing the volume ratio of the thermally conductive filler to the curable liquid resin, it is preferable to use two or more types of thermally conductive fillers with different particle sizes. In this case, it is preferable to use a thermally conductive filler with a particle size of more than 5 μm as the thermally conductive filler with a larger particle size, and a thermally conductive filler with a particle size of 5 μm or less as the thermally conductive filler with a smaller particle size.

[0034] When two or more types of thermally conductive fillers are used in combination, these thermally conductive fillers may be thermally conductive fillers having the same composition, or may be thermally conductive fillers having different compositions.

[0035] Furthermore, by appropriately combining a thermally conductive filler having a small maximum particle size, the thin film property of the cured product can be ensured. The maximum particle size is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. By using a thermally conductive filler having a small maximum particle size, the curable resin composition can be poured into a narrow gap.

[0036] <Metal tube manufacturing process> The manufacturing process of the metal tube 1 according to this embodiment includes five steps: "metal tube manufacturing step," "step of applying adhesive to the inner surface of the application part 41," "drying step," "resin filling step," and "bending step." The manufacturing process of the metal tube will be described below with reference to the attached drawings.

[0037] (Metal tube manufacturing process) A known method such as impact extrusion can be used to manufacture the metal tube having the body portion 2 and the discharge portion 30. Through this process, an unfolded metal tube as shown in Fig. 2 is obtained. Since this allows for a large amount of moisture-curable resin composition to be contained, the inner diameter A of the body portion 2 of the tube of the present invention is preferably 0.9 cm or more.

[0038] (Step of applying adhesive to the inner surface of application section 41) Next, the adhesive is applied to the inner surface of the coating part 41 shown by the hatching in FIG. 2, i.e., the inner wall surface at the other end of the cylindrical body part 2, using general coating equipment such as a spray coater or a brush. The adhesive is applied at any time before the moisture-curing resin composition is filled. The type of adhesive used here is not particularly specified, but is preferably any adhesive selected from urethane-based, acrylic-based, epoxy-based, and silicone-based adhesives. By sealing with a urethane-based, acrylic-based, epoxy-based, or silicone-based adhesive, the coating part 41 can be sufficiently firmly bonded and the metal tube 1 can be sealed.

[0039] (drying process) Next, a drying step is carried out in which the solvent contained in the adhesive in the coating section 41 is volatilized.

[0040] (Resin filling process) Next, the nozzle is inserted into the end of the side where the adhesive was applied, and the resin is filled in. The resin is pushed out from the tip of the tube on the outlet side, and after a specified amount has been filled, the nozzle is removed.

[0041] Fig. 4 is a diagram showing the relationship between the moisture-curable resin composition filling section 5, the coating section 41, and the folded and sealed section 4. The diagram indicated by reference numeral 101 in Fig. 4 is a partial cross-sectional view showing the metal tube 1 in a state where the other end side maintains a cylindrical shape. The diagram indicated by reference numeral 102 in Fig. 4 is a side view showing the state of the metal tube 1 immediately before the other end side is folded.

[0042] In the state indicated by reference numeral 101 in Fig. 4, an air layer exists between the moisture-curable resin composition filling portion 5 and the coating portion 41. As indicated by reference numeral 102, the moisture-curable resin composition is filled into the air layer by squeezing the other end side of the body portion 2. When filling with a highly viscous moisture-curable resin composition as in this embodiment, even if the tube is coated with an adhesive, if the filling seeps out to the coating portion 41 during the filling operation, there is a possibility that the adhesive strength will decrease.

[0043] Therefore, the amount of the moisture-curable resin composition to be filled and the range of the coating part 41 are specified so that the moisture-curable resin composition does not penetrate into the inside of the coating part 41. Specifically, as shown in FIG. 4, when the inner diameter (diameter) of the body part 2 is A, the distance from the end of the end of the body part 2 to the part (filling part 5) where the moisture-curable resin composition is filled is B, and the coating width of the adhesive in the longitudinal direction of the metal tube 1 is C, the amount of the filling and the range of the coating part 41 are specified so that 1.6≦B / A≦2.0 and B>C are satisfied. Preferably, the amount of the filling and the range of the coating part 41 are specified so that 1.7≦B / A≦1.9 and B>C are satisfied. If B / A is smaller than 1.6, the moisture-curable resin composition penetrates into the coating part 41, and the metal tube 1 cannot be sealed. If B / A is larger than 2.0, a lot of air remains inside, and the curing of the moisture-curable resin composition proceeds. By controlling B / A within this range, it becomes possible to prevent these problems and seal the metal tube 1 while preventing hardening of the moisture-curable resin composition.

[0044] Moreover, by making the distance C between the other ends of coating part 41 smaller than B, the resin does not reach the adhesive coating part, and the adhesive strength does not decrease. Furthermore, from the viewpoint of ensuring sufficient adhesive strength in coating part 41, it is preferable that distance C between one end side and the other end side of coating part 41 is 1 cm or more.

[0045] (Bending process) Next, the other end of the body 2 is folded at a predetermined interval to form the folded sealed portion 4. The view indicated by reference numeral 103 in FIG. 4 is a plan view of the metal tube 1 indicated by reference numeral 102. By squeezing the other end of the body 2, the width of the other end increases. In the view indicated by reference numeral 103, the width of the other end of the body 2 (the width in the direction perpendicular to the longitudinal direction of the metal tube 1) is πA / 2. In this state, the other end of the body 2 is folded at a predetermined interval.

[0046] By going through the above five steps, a metal tube in a folded state as shown in Fig. 1 is obtained. Note that the manufacturing method of the metal tube 1 according to this embodiment may include at least a coating step of coating an adhesive on the inner surface of the end of the body portion 2 of the metal tube 1, a drying step of drying a solvent contained in the adhesive, a filling step of filling the body portion 2 with a moisture-curable resin composition, and a folding step of folding the end portion in multiple stages.

[0047] <Application method> A method for applying the moisture-curable resin composition to the surface of a substrate, which is an object to be coated, using the metal tube 1 will be described. First, a hole is made in the closed portion 34 of the discharge port 32. After the discharge port 32 is opened, pressure is applied to the metal tube 1 with a finger, and the moisture-curable resin composition discharged from the discharge port 32 is applied to the surface of the substrate. Alternatively, the moisture-curable resin composition discharged from the discharge port 32 is transferred to a syringe, and then a fixed amount is discharged and applied to the surface of the substrate.

[0048] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0049] 1 Metal tube 2. Torso 32 ·Discharge port 34 ·Occluded area 4. Folded sealing section A: Inner diameter of the body B: Distance from the end of the other end to the part filled with moisture-curing resin C: Width of adhesive applied along the longitudinal axis of the metal tube

Claims

1. A metal tube filled with a moisture-curable resin composition, The metal tube is A body portion to be filled with the moisture-curable resin composition; A discharge port capable of discharging the contents, the discharge port being provided at one end of the body portion; A folded seal portion provided at the other end of the body portion and folded and sealed in multiple stages, An adhesive is applied to the inner surface of the folded seal portion, The moisture-curable resin composition is adjusted to have a viscosity of 200 PaS or more and 800 PaS or less at 23° C., The metal tube, wherein the adhesive is any one selected from a urethane-based, an acrylic-based, an epoxy-based, and a silicone-based adhesive.

2. A metal tube filled with a moisture-curable resin composition, The metal tube is A body portion to be filled with the moisture-curable resin composition; A discharge port capable of discharging the contents, the discharge port being provided at one end of the body portion; A folded seal portion provided at the other end of the body portion and folded and sealed in multiple stages, An adhesive is applied to the inner surface of the folded seal portion, The moisture-curable resin composition is adjusted to have a viscosity of 200 PaS or more and 800 PaS or less at 23° C., In the folded sealed portion, The inner diameter of the body of the metal tube is A, the distance from the end of the other end to the portion filled with the moisture-curable resin is B, and the application width of the adhesive in the longitudinal direction of the metal tube is C, A metal tube, wherein 1.6≦B / A≦2.0 and B>C.

3. A metal tube filled with a moisture-curable resin composition, The metal tube is A body portion to be filled with the moisture-curable resin composition; A discharge port capable of discharging the contents, the discharge port being provided at one end of the body portion; A folded seal portion provided at the other end of the body portion and folded and sealed in multiple stages, An adhesive is applied to the inner surface of the folded seal portion, The moisture-curable resin composition is adjusted to have a viscosity of 200 PaS or more and 800 PaS or less at 23° C., The moisture-curable resin composition has a peel strength of 1 N / cm or less in a 180° peel test at 23° C.

4. The metal tube according to claim 1 , further comprising a blocking portion that blocks the discharge port in a breakable manner.

5. The metal tube according to claim 1 , wherein the moisture-curable resin composition is a thermally conductive resin composition containing at least a moisture-curable resin and a thermally conductive filler.

6. A method for producing a metal tube filled with a moisture-curable resin composition, comprising the steps of: a coating step of coating an inner surface of an end portion of the body portion of the metal tube with an adhesive; A drying step of drying a solvent contained in the pressure-sensitive adhesive; a filling step of filling the body with a moisture-curable resin composition; and a bending step of bending the end portion in multiple stages. The inner diameter of the body is A, the distance from the end of the end to the portion filled with the moisture-curable resin composition is B, and the application width of the adhesive in the longitudinal direction of the metal tube is C, The method for producing a metal tube, wherein in the filling step, the moisture-curable resin composition is filled so that 1.6≦B / A≦2.0 and B>C are satisfied.

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