LIU YINGCHUN (CN)
PETER DANY (CN)
WO2012078826A2 | 2012-06-14 |
EP1865019A1 | 2007-12-12 | |||
US20140147636A1 | 2014-05-29 | |||
JPH107993A | 1998-01-13 | |||
EP0414030A2 | 1991-02-27 | |||
JPH01104681A | 1989-04-21 |
CLAIMS Claim 1 : A sealing tape for welding, comprising a base layer, and a hot-melted polymer layer sprayed on the base layer; characterized in that the hot-melted polymer layer has a network structure formed by hot-melted polymer fibers. Claim 2: The sealing tape for welding according to claim 1 , characterized in that the base layer comprises one or more of polyethylene/ethylene vinyl acetate, ethylene propylene diene monomer, epoxy resin, and styrene-butadiene/isoprene copolymer. Claim 3: The sealing tape for welding according to claim 1 or 2, characterized in that the hot-melted polymer layer comprises one or more of polyethylene/ethylene vinyl acetate, polyamide, ethylene-octene copolymer, and styrene-butadiene/isoprene copolymer. Claim 4: The sealing tape for welding according to any one of claims 1 -3, characterized in that the base layer has a thickness of 0.5 mm to 3 mm. Claim 5: The sealing tape for welding according to any one of claims 1 -4, characterized in that the hot-melted polymer layer has a thickness of 0.3 mm to 2 mm. Claim 6: A method of preparing the sealing tape for welding according to any one of claims 1 -5, comprising: (1 ) a step of subjecting raw materials of a base layer to extrusion molding to obtain a base layer; (2) a step of in-situ spraying hot-melted polymer fibers on the surface of the base layer; and (3) a step of cooling to obtain the sealing tape for welding. Claim 7: The preparation method according to claim 6, characterized in that the nozzle pressure is from 2.5 to 4.5 kgf/cm2 at the time of spraying the hot-melted polymer fibers. Claim 8: The preparation method according to claim 6 or 7, characterized in that the step (1 ) and the step (2) are carried out simultaneously. Claim 9: The sealing tape for welding according to any one of the preceding claims wherein the density of the sealing tape as measured by ASTM D297 is from about 0.5 to about 3.0 g/cm3. Claim 10: The sealing tape for welding according to any one of the preceding claims wherein the density of the sealing tape as measured by ASTM D297 is from about 1 to about 1.5 g/cm3. Claim 1 1 : The sealing tape for welding according to any one of the preceding claims wherein the volume expansion of the sealing tape measured at about 149°C to about 163°C is between 0% and 300%. Claim 12: The sealing tape for welding according to any one of the preceding claims wherein the volume expansion of the sealing tape measured at about 149°C to about 163°C is between 100% and 300%. |
FIELD OF THE INVENTION
[0001] The present invention relates to a sealing tape for welding and a preparation method thereof. The sealing tape for welding has a hot-melted polymer layer, and belongs to the technical filed of a sealing tape for welding.
BACKGROUND OF THE INVENTION
[0002] With the development of industrial technologies, particularly the rapid development of the automobile industry, traditional welding technologies cannot already satisfy modernized assembly-line large-scale industrial production. At present, numerous automobile manufacturers have adopted welding technologies, especially spot-welding technologies to form a vehicle body, which greatly improves production efficiency, but the skin lapping zone between adjacent welding dots needs to be well sealed to avoid entrance of rainwater and dust, and meanwhile, this is also necessary for heat-insulating sealing for air-condition vehicles.
[0003] Sealing tapes for welding are primarily used for spot welding zones of various automobiles, vehicle doors, hoods, roofs and trunks. Sealing tapes for welding have excellent adhesion to oily surfaces, weldability, elasticity, filling and good adhesiveness, and they also featured in acid and alkali resistance, low and high temperature resistance, waterproof and the like.
[0004] Currently, commercially available sealing tapes for welding must be added with conductive particles so that spot welding can be conducted in the workpiece lapping zones, and a sealing tape for welding has powerful surface viscosity so as to ensure an adhesive effect, so it is inconvenient to handle. SUMMARY OF THE INVENTION
[0005] As to problems currently existing in sealing tapes for welding of the prior art, the technical problem to be solved by the present invention is to provide a sealing tape for welding characterized by ensuring the welding effect of an adhered metal, convenient handling and simple synthetic process, and a preparation method thereof.
[0006] According to the present invention, there is provided a sealing tape for welding comprising a base layer, and a hot-melted polymer layer sprayed on the base layer and having a network structure formed by hot-melted polymer fibers.
[0007] According to the sealing tape for welding of the present invention, the base layer comprises one or more of polyethylene/ethylene vinyl acetate, ethylene propylene diene monomer, epoxy resin, and styrene-butadiene/isoprene copolymer.
[0008] According to the sealing tape for welding of the present invention, the hot-melted polymer layer comprises one or more of polyethylene/ethylene vinyl acetate, polyamide, ethylene-octene copolymer, and styrene-butadiene/isoprene copolymer.
[0009] According to the sealing tape for welding of the present invention, the base layer has a thickness of 0.5 mm to 3 mm.
[0010] According to the sealing tape for welding of the present invention, the hot-melted polymer layer has a thickness of 0.3 mm to 2 mm.
[0011] A method of preparing the sealing tape for welding according to the present invention, comprising: (1 ) a step of subjecting raw materials of a base layer to extrusion molding to obtain a base layer; (2) a step of in-situ spraying hot-melted polymer fibers on the surface of the base layer; and (3) a step of cooling to obtain the sealing tape for welding.
[0012] The preparation method according to the present invention, characterized in that the nozzle pressure is from 2.5 to 4.5 kgf/cm2 at the time of spraying the hot-melted polymer fibers.
[0013] The preparation method according to the present invention, characterized in that the step (1 ) and the step (2) are carried out simultaneously. [0014] The sealing tape for welding of the present invention solves a problem about surface treatment of a viscous tape for welding, which not only protects an adhesive effect between a tape for welding and the adhered surface, but solves a problem about inconvenient handling of viscous surfaces, while ensuring a welding effect of an adhered metal to the utmost.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a drawing showing an actual effect of the sealing tape for welding of Example 1 of the present invention.
DETAILED DESCRIPTION
[0016] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the teachings, its principles, and its practical application. Those skilled in the art may adapt and apply the teachings in its numerous forms, as may be best suited to the requirements of a particular use. Accordingly, the specific embodiments of the present teachings as set forth are not intended as being exhaustive or limiting of the teachings. The scope of the teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference into this written description.
[0017] This application claims the benefit of the filing date of Chinese patent Application No. 201610232641 .9, filed April 14, 2016, the entirety of the contents of that application being hereby incorporated by reference herein for all purposes.
[0018] The sealing tape for welding of the present invention comprises a base layer, and a hot-melted polymer layer sprayed on the base layer and having a network structure formed by hot-melted polymer fibers. [0019] First, as raw materials of the base layer, there is no particular limitation, for example, they may be one or more of polyethylene/ethylene vinyl acetate, ethylene propylene diene monomer, epoxy resin, and styrene-butadiene/isoprene copolymer.
[0020] The base layer has a thickness of 0.5 mm to 3 mm. Base layers of sealing tapes having a thickness within this range would not influence welding technologies or properties of welded junction.
[0021] As raw materials of the hot-melted polymer layer, they may be one or more of polyethylene/ethylene vinyl acetate, polyamide, ethylene-octene copolymer, and styrene-butadiene/isoprene copolymer. With the adoption of the above raw materials, an ideal hot-melted polymer network can be attained by selecting a suitable hot melt temperature and nozzle pressure.
[0022] The hot-melted polymer layer has a thickness of 0.3 mm to 2 mm. Network structures of hot-melted polymer fibers having a thickness within this range would not influence welding technologies or properties of welded junction.
[0023] The hot-melted polymer layer has a network structure formed by hot-melted polymer fibers. During welding, the aforementioned network structure would not affect formation of a current path for welding to weld an adhered material without additionally adding conductive fillers to a hot-melted polymer layer.
[0024] In the network structure, the porosity can be adjusted by regulating a hot-melt spinning process according to the performance of the base material, and the porosity capable of achieving an optimum welding effect shall prevail.
[0025] The present invention also provides a method of preparing the sealing tape for welding according to the present invention, comprising: a step of subjecting raw materials of a base layer to extrusion molding; a step of in-situ spraying hot-melted polymer fibers on the surface of the base layer; and a step of cooling to obtain the sealing tape for welding. The nozzle pressure is from 2.5 to 4.5 kgf/cm2 at the time of spraying the hot-melted polymer fibers.
[0026] As shown for example at Fig. 1 , the sealing tape is shown including a base layer 1 and a hot-melt polymer fiber layer 2.
[0027] EXAMPLES [0028] The following is provided with Examples of the present invention only for the purpose of explanation and description, instead of limiting the present invention.
[0029] Example 1
[0030] An ethylene-vinyl acetate copolymer (EVA) was used as a raw material of a base layer. The EVA was extruded into a sheet of 1 .5 mm in thickness at 1 10°C, and EVA hot-melted polymer fibers was on-line sprayed at 160°C, wherein the nozzle pressure was 3.5 kgf/cm2. After cooling, a sealing tape for welding was obtained. Test results were listed in Table 1 .
[0031] Example 2
[0032] An ethylene propylene diene monomer (EPDM) was used as a raw material of a base layer. The EPDM was extruded into a sheet of 1.3 mm in thickness at 1 10°C, and EVA hot-melted polymer fibers was on-line sprayed at 160°C, wherein the nozzle pressure was 3.5 kgf/cm2. After cooling, a sealing tape for welding was obtained. Test results were listed in Table 1 .
[0033] Comparative Example 1
[0034] An ethylene-vinyl acetate copolymer (EVA) was used as a raw material of a base layer. The EVA was extruded into a sheet of 1 .5 mm in thickness at 1 10°C, and EVA hot-melted polymer fibers was on-line sprayed at 160°C, wherein the nozzle pressure was 1 .5 kgf/cm2. An ideal surface-treated film cannot be attained due to improper setting of the nozzle pressure.
[0035] Table 1
Adhesive
strength
Stainless steel
sheet Not removable in a Not removable in a
Galvanized continuous strip continuous strip steel sheet
Low
temperature
resistance
Stainless steel
sheet No cracking or loss of No cracking or loss of
Galvanized adhesion adhesion steel sheet
No evidence of wash off
Wash No evidence of wash off or
FLTM BV 1 16-01 or
resistance displacement
displacement
Welding
FLTM BV 109-01 Shall be weldable Shall be weldable performance
[0036] The sealing tape may include an impact modifier. The sealing tape may be substantially free of any impact modifier. The impact modifier, if present, may include one or more core/shell polymers. As used herein, the term core/shell polymer describes an impact modifier wherein a substantial portion (e.g., greater than 30%, 50%, 70% or more by weight) thereof is comprised of a first polymeric material (i.e., the first or core material) that is substantially entirely encapsulated by a second polymeric material (i.e., the second or shell material). The first and second polymeric materials, as used herein, can be comprised of one, two, three or more polymers that are combined and/or reacted together (e.g., sequentially polymerized) or may be part of separate or same core/shell systems. The first polymeric material, the second polymeric material or both of the core/shell impact modifier include or are substantially entirely composed of (e.g., at least 70%, 80%, 90% or more by weight) one or more thermoplastics. Exemplary thermoplastics include, without limitation, styrenics, acrylonitriles, acrylates, acetates, polyamides, polyethylenes or the like. It may be desirable for the glass transition temperature of the first or core polymeric material to be below 23 °C while the glass temperature of the second or shell polymeric material to be above 23 °C, although not required.
[0037] The sealing tape may also include one or more additional polymer and/or copolymer materials, such as thermoplastics, elastomers, plastomers, combinations thereof or the like. The adhesive or sealant may include polyurethanes. Silane-modified polymers may be included.
[0038] One or more additional polymeric materials may be included. Such polymeric materials may include but are not limited to halogenated polymers, polycarbonates, polyketones, urethanes, polyesters, silanes, sulfones, allyls, olefins, styrenes, acrylates, methacrylates, silicones, phenolics, rubbers, polyphenylene oxides, terphthalates, acetates (e.g., EVA), acrylates, methacrylates (e.g., ethylene methyl acrylate polymer) or mixtures thereof. Other potential polymeric materials may be or may include, without limitation, polyolefin (e.g., polyethylene, polypropylene), ethylene octane copolymer, polystyrene, polyacrylate, poly(ethylene oxide), poly(ethyleneimine), polyester, polysiloxane, polyether, polyphosphazine, polyamide, polyimide, polyisobutylene, polyacrylonitrile, polyvinyl chloride), poly(methyl methacrylate), polyvinyl acetate), poly(vinylidene chloride), polytetrafluoroethylene, polyisoprene, polyacrylamide, polyacrylic acid, polymethacrylate.
[0039] In one embodiment, the sealing tape may include an elastomer-based material. In such an embodiment, the sealing tape may include elastomers such as natural rubber, styrene-butadiene rubber, polyisoprene, polyisobutylene, polybutadiene, isoprene-butadiene copolymer, neoprene, nitrile rubber (e.g., a butyl nitrile, such as carboxy-terminated butyl nitrile), butyl rubber, polysulfide elastomer, acrylic elastomer, acrylonitrile elastomers, silicone rubber, polysiloxanes, polyester rubber, diisocyanate- linked condensation elastomer, EPDM (ethylene-propylene diene rubbers), chlorosulphonated polyethylene, fluorinated hydrocarbons, combinations thereof and the like. According to the preferred formulations, the base material includes up to about 30% by weight elastomers, more preferably, up to about 40% by weight elastomers, and even more preferably up to about 60% by weight elastomers.
[0040] Any numerical values recited herein include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51 , 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001 , 0.001 , 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. As can be seen, the teaching of amounts expressed as "parts by weight" herein also contemplates the same ranges expressed in terms of percent by weight. Thus, an expression in the Detailed Description of the Invention of a range in terms of at "V parts by weight of the resulting polymeric blend composition" also contemplates a teaching of ranges of same recited amount of "x" in percent by weight of the resulting polymeric blend composition."
[0041] Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", inclusive of at least the specified endpoints.
[0042] The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The term "consisting essentially of" to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of the elements, ingredients, components or steps. By use of the term "may" herein, it is intended that any described attributes that "may" be included are optional.
[0043] Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. The disclosure of "a" or "one" to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps. All references herein to elements or metals belonging to a certain Group refer to the Periodic Table of the Elements published and copyrighted by CRC Press, Inc. , 1989. Any reference to the Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the lUPAC system for numbering groups.
[0044] It will be appreciated that concentrates or dilutions of the amounts recited herein may be employed. In general, the relative proportions of the ingredients recited will remain the same. Thus, by way of example, if the teachings call for 30 parts by weight of a Component A, and 10 parts by weight of a Component B, the skilled artisan will recognize that such teachings also constitute a teaching of the use of Component A and Component B in a relative ratio of 3: 1 . Teachings of concentrations in the examples may be varied within about 25% (or higher) of the stated values and similar results are expected. Moreover, such compositions of the examples may be employed successfully in the present methods.
[0045] It is understood that the above description is intended to be illustrative and not restrictive. Many embodiments as well as many applications besides the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission in the following claims of any aspect of subject matter that is disclosed herein is not a disclaimer of such subject matter, nor should it be regarded that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter.