Pumpable expandable sealant useful for vehicles

Abstract

Disclosed are a pumpable, expandable composition useful for sealing vehicle cavities, and a method of applying the composition that significantly improves vertical and inversion resistance without impairing performance. The composition and method of application of the present invention increase versatility in sealing larger gaps and cavities by improving the expansion height.

Description

[Technical Field]

[0001] The present invention relates to a pumpable, heat-expandable sealant useful for filling and sealing cavities in vehicles. [Background technology]

[0002] Extruded tapes or injection-molded parts are commonly used as cavity fillers, such as so-called pillar fillers, which are placed in the roof supports of the B-pillars of vehicles. Both products tend to be labor-intensive because they are installed manually in vehicles. Such products require customers to invest in expensive tools, packaging, and storage space for each part shape, increasing management and logistical complexity. Furthermore, the numerous manufacturing processes involved result in longer cycle times. Therefore, there is a need for simpler cavity fillers and sealants that offer similar performance to conventional parts and tapes while overcoming at least some of the drawbacks of these products.

[0003] Using pumpable expandable sealants can result in significant cost savings compared to tapes or injection molded parts. Because pumpable expandable sealants can be applied using automated application methods and equipment, extrusion or injection molding is unnecessary, and they can be applied using standard pumping equipment. Pumpable expandable sealants reduce management and logistics complexity and save warehouse space. Since the material can be supplied in buckets or drums, the number of packages can be reduced compared to packaging various sizes of 2D tapes and 3D parts in multiple parts and packaging containers.

[0004] Challenges remain in providing pumpable, expandable sealants as an alternative to 2D tapes and 3D parts. For example, a pumpable, expandable, uncured sealant must not flow out of place for up to 2, 4, 6, 8, 10, or 12 weeks after application to a metal surface such as a metal car body. Some pumpable materials raise concerns regarding sagging when applied in a vertical and / or inverted position, especially when the bead thickness exceeds 10-20 mm. U.S. Patent No. 10,836,881 attempted to address the sagging problem by incorporating epoxy resin and 25-35% by weight of filler. Materials containing epoxy filler combinations have poor sealing performance due to increased rigidity. The material shrinks after curing and cooling after expanding. If the cured material is hard, a hole may form between the material and the top panel due to shrinkage and low flexibility. Other paste-like, thermoplastic materials containing large amounts of inorganic filler also have similar performance problems, as they harden and lose flexibility after curing and cooling. Japanese Patent No. 3017571 describes a paste-type thermal expandable pillar filler for automated application, which contains an amount of liquid rubber that makes it difficult to retain gases generated from the foaming agent, potentially leading to bubble collapse and poor sealing. U.S. Patent Application Publication 2013-0280451 discloses a paste-type thermal expandable filler comprising uncrosslinked rubber, a quinone vulcanizing agent, and a foaming agent. This material contains a quinone vulcanizing agent that acts as a self-skinning agent to maintain the shape of the bead and prevent sagging, but has the drawback of inhibiting wetting between the contacting metal panel and the bead surface during curing, thereby hindering sealing.

[0005] Therefore, there is a need for pumpable cavity fillers and sealants that overcome at least some of the shortcomings of known pumpable or paste-like products, while providing performance similar to conventional parts and tapes, and including resistance to sagging in addition to expansion and adhesion for bridging and / or filling cavities. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent No. 10,836,881 [Patent Document 2] Patent No. 3017571 [Patent Document 3] U.S. Patent Application Publication 2013-0280451 [Overview of the Initiative] [Means for solving the problem]

[0007] This disclosure relates to novel compositions, including pumpable, heat-expandable sealant compositions that expand upon heating and adhere to the surface of cavities to seal them. The pumpable, heat-expandable sealant compositions of the present invention offer improved sagging resistance in addition to expansion and adhesion. Furthermore, the disclosure provides assemblies with improved cavity sealing, as well as methods for producing these liquid epoxy adhesives and methods for sealing products, obtained by applying the pumpable, heat-expandable sealant composition to one or more surfaces of cavities or cavity portions to be sealed and curing the pumpable, heat-expandable sealant composition. Throughout this disclosure, various embodiments of the present invention are described, including, for example, the following:

[0008] Embodiment 1 A pumpable, heat-expandable sealant composition comprising, or essentially consisting of, or comprising synthetic rubber, preferably styrene-butadiene rubber (SBR); PVC homopolymer or copolymer; wax thixotropic agent; foaming agent; optionally functionalized liquid rubber; vulcanizing agent; vulcanization accelerator; and one or more fillers.

[0009] Embodiment 1a A pumpable, heat-expandable sealant composition comprising, or essentially consisting of, or comprising SBR rubber; PVC homopolymer / copolymer and / or acrylic resin powder having a Tg in the range of 50 to 120°C; amide wax thixotropy agent having a melting point in the range of 80 to 150°C; foaming agent; functionalized liquid rubber; sulfur vulcanizing agent; one or more vulcanization accelerators; and at least one filler.

[0010] Embodiment 2 The wax thixotropic agent contains amide wax, and the composition is any one of the compositions of the preceding embodiments that optionally further contains fumed silica, preferably hydrophilic fumed silica.

[0011] Embodiment 3 The PVC polymer is a homopolymer present in an amount sufficient to thicken the composition in order to enhance the sag resistance after application while maintaining a pumpable viscosity during application, in any one of the compositions of the preceding embodiments.

[0012] Embodiment 4 The liquid rubber is preferably functionalized with maleic anhydride, in any one of the compositions of the preceding embodiments.

[0013] Embodiment 5 The composition contains less than 5% by weight of an epoxy resin, in any one of the compositions of the preceding embodiments.

[0014] Embodiment 6 The composition further contains a peroxide curing agent, in any one of the compositions of the preceding embodiments.

[0015] Embodiment 7 The composition further contains a co-crosslinking agent containing a poly(meth)acrylate functional crosslinking agent preferably having a plurality of unsaturated sites, in any one of the compositions of the preceding embodiments.

[0016] Embodiment 8 The co-crosslinking agent contains a polyacrylate functional crosslinking agent having at least 4 unsaturated sites, in the composition of Embodiment 7.

[0017] Embodiment 9 The composition further contains a plasticizer preferably in an amount of 15 to 55% by weight, in any one of the compositions of the preceding embodiments.

[0018] Embodiment 10 The composition further contains an antioxidant, in any one of the compositions of the preceding embodiments.

[0019] Embodiment 11 a. SBR rubber present in an amount of 5-30% by weight, preferably 7-20% by weight, most preferably at least 12-13-14-15% by weight; b. PVC homopolymer / copolymer and / or acrylic resin powder having a Tg preferably in the range of 50 to 120°C and present in an amount of 2 to 35% by weight, preferably 5 to 30% by weight; c. An amide wax thixotropic agent having a melting point preferably in the range of 80 to 150°C, present in an amount of 0.25% to 5% by weight, preferably about 0.5% to 6% by weight; d. A foaming agent present in an amount of 0.5% to approximately 15% by weight, preferably 1.0% to 10% by weight (OBSH is preferred, but ADCA including an accelerator package may also be used); e. Optionally functionalized liquid rubber present in an amount of 0.25-20% by weight, preferably 0.5-10% by weight; f. Sulfur present in an amount of approximately 0.1% to 4% by weight, preferably 0.2% to 2% by weight; A sulfur crosslinking accelerator present in an amount of approximately 0.25 to 4% by weight, preferably approximately 0.5% to 5% by weight; h. Plasticizer present in an amount of approximately 15-55% by weight, preferably 20-50% by weight; i. A filler present in an amount of approximately 1 to 25% by weight, preferably 1 to 20% by weight; j. Antioxidants having a melting point preferably above 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C, and present in an amount of 0.25 to 1.25% by weight, preferably 0.5 to 1.5% by weight; k. Optionally, the mixture may contain one or more of fumed silica, peroxide curing agents, and cocrosslinking agents, each independently present in an amount of up to 2.0% by weight; including, essentially consisting of, or comprising All of the above amounts are based on the total amount of the composition of Embodiment 1 or 1a.

[0020] Embodiment 12 The composition of Embodiment 11, wherein the functionalized liquid rubber is functionalized with an anhydride functional group, an epoxy functional group, or an acid functional group, preferably 0.1 to 30% maleic anhydride functional group, and the liquid rubber is present in an amount of 0.25 to 20% by weight, preferably 0.5 to 10% by weight.

[0021] Embodiment 13 The composition of Embodiment 11 or 12, wherein the peroxide curing agent and the cocrosslinking agent are present in an amount of 0.1 to 2% by weight, the liquid rubber is functionalized with maleic anhydride, and the composition can be cured at a metal temperature of 140°C for about 15 to 20 minutes.

[0022] Embodiment 14 a) A step of applying a pumpable, thermally expandable sealant composition described in any of the preceding embodiments to gaps or cavities in an article, preferably including a metal surface; and b) A step of heating the article containing the pumpable, thermally expandable sealant composition to a temperature above the activation temperature of the foaming agent to expand the sealant, thereby forming an expandable material in gaps or cavities in the article, thereby creating a reinforced and / or sealed portion of the gap or cavity in the article, preferably a step of expanding the material from the surface to which it is applied to the opposite side of the cavity to be sealed, and reaching the opposite metal surface; A method for manufacturing articles containing [a certain type of] article.

[0023] Embodiment 15 The method of Embodiment 14, wherein the article is a vehicle part, preferably a part of an aircraft, automobile, ship, or construction vehicle.

[0024] Embodiment 16 A component having a metal surface, a composite material surface, or a combination of the said surfaces; An uncured, heat-expandable sealant deposited on a portion of the surface, comprising: SBR rubber; PVC homopolymer / copolymer and / or acrylic resin; amide wax; foaming agent; liquid rubber functionalized with maleic anhydride functional groups, epoxy functional groups or acid functional groups; sulfur-containing vulcanizing agent; one or more vulcanization accelerators; and at least one filler; Products containing, A product wherein the sealant is curable within target firing conditions of 15 minutes at a metal temperature of 140°C and exhibits at least 80% cohesive failure modes.

[0025] The product of Embodiment 16, wherein the uncured thermally expandable sealant deposited on the surface shows a height increase of less than 10% after a 24-hour inversion residence time.

[0026] The product of Embodiment 16, wherein the uncured thermally expandable sealant is capable of expanding vertically to more than eight times its initial height during firing at 140°C for 15 minutes.

[0027] The product of Embodiment 16, wherein the product is a vehicle part, preferably a part of an aircraft, automobile, ship, or construction vehicle. [Brief explanation of the drawing]

[0028] [Figure 1] Figure 1 shows a top view photograph of a CRS panel in which the uncured, expandable sealant composition of the present invention has been applied to the central portion of the surface. [Figure 2] Figure 2 is a top view photograph of the CRS panel shown in Figure 1, in which the uncured expandable sealant composition of the present invention is applied to the central portion of the surface, and spacer blocks are placed in the uncoated portions of the CRS surface at each corner of the panel. [Figure 3] Figure 3 is a top view photograph of an assembly including the CRS panel (not shown) of Figure 2 and a second CRS panel positioned on top of the CRS panel of Figure 2 and supported on the spacer block of Figure 2. The assembly further includes clamps that secure the panels to the spacers at each corner and hold the assembly together. [Figure 4] Figure 4 shows a side view of the assembly shown in Figure 3 before firing of the expandable sealant composition of the present invention, illustrating the gaps between the CRS panels. [Figure 5]Figure 5 shows a side view of the assembly shown in Figure 3 after firing of the expandable sealant composition of the present invention, illustrating the foamed sealant filling a portion of the gaps between CRS panels. [Modes for carrying out the invention]

[0029] The subject matter of the inventions disclosed herein may be more readily understood by referring to the following detailed description in conjunction with the accompanying drawings and examples that constitute part of this disclosure. It should be understood that these inventions are not limited to the specific components, methods, or parameters described and / or shown herein. Furthermore, it should be understood that the terms used herein are for illustrative purposes only to illustrate specific embodiments and do not limit the claimed inventions.

[0030] This disclosure provides a pumpable, heat-expandable sealant composition comprising, or essentially consisting of, or comprising synthetic rubber, preferably styrene-butadiene rubber (SBR), polyvinyl homopolymer or copolymer, wax thixotropy agent, foaming agent, optionally functionalized liquid rubber, vulcanizing agent, vulcanization accelerator, and one or more fillers.

[0031] In some embodiments, the pumpable, heat-expandable sealant composition includes: SBR rubber; PVC homopolymer / copolymer and / or acrylic resin powder having a Tg in the range of 50 to 120°C; amide wax thixotropy agent having a melting point in the range of 80 to 150°C; a foaming agent; liquid rubber functionalized with maleic anhydride functional groups, epoxy functional groups or acid functional groups; a vulcanizing agent, preferably sulfur; one or more vulcanization accelerators, e.g., octadecanoic acid, tetramethylthiuram disulfide (TMTD), zinc oxide; and at least one filler, e.g. The composition comprises, essentially, or consists of, carbon black, calcium carbonate, and magnesium silicate; optional additional additives include silica, fumed silica; secondary peroxide curing agents, e.g., dicumyl peroxide and / or cocrosslinking agents, e.g., poly(meth)acrylate functional crosslinking agents having 2, 3, 4, 5 or more unsaturated moieties; antioxidants, e.g., 4,4'-methylenebis(2,6-di-tert-butylphenol); and plasticizers, i.e., extendable oils such as diisononyl phthalate, petroleum distillates, and naphthenic oils. In preferred embodiments, the pumpable, thermally expandable sealant composition contains less than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5, or 0.1% by weight of epoxy resin, in preferred order.

[0032] The essential components of the pumpable, heat-expandable sealant composition include, as component a, rubber, particularly synthetic rubber, preferably partially crosslinked synthetic rubber. Examples of partially crosslinked rubbers used in the filler composition of the present invention include, for example, acrylonitrile-isoprene copolymer rubber (NIR), acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR). Crosslinking may be achieved by adding a crosslinking agent such as divinylbenzene or sulfur. The addition of rubber provides advantages such as improved rheological properties, sagging resistance, wash resistance, and volume expansion rate of the resulting filler composition.

[0033] The pumpable, heat-expandable sealant composition contains polyvinyl chloride (PVC) resin as component b, which may be a polyvinyl chloride homopolymer or copolymer, and optionally acrylic resin powder may be used instead of PVC or in combination with PVC. Preferably, the material of component b has a Tg in the range of 50°C to 120°C. In some embodiments, the PVC is a homopolymer such as the Formulan brand, which also includes homopolymers from Formosa.

[0034] The pumpable, heat-expandable sealant composition contains a thixotropic agent as component c, which is a wax, and this wax may be a synthetic wax, petrochemical wax, or natural wax having a melting point in the range of 80°C to 150°C. Amide waxes are preferred and may be used alone or in combination with other waxes disclosed, as long as the objectives of the present invention are satisfied.

[0035] Another essential component of a pumpable, heat-expandable sealant composition is a blowing agent, which is component d that causes the sealant composition to expand during firing. Any substance that decomposes upon heating and generates gas may be used. Various known blowing agents may be used as long as they do not impair the performance of the present invention (e.g., sagging resistance and low firing curing properties). This includes so-called endothermic blowing agents, which are combinations of organic acids such as citric acid and carbonates such as sodium bicarbonate. OBSH is preferred, but ADCA may also be used in combination with an accelerator package. The blowing agent needs to be sufficiently stable in the composition to prevent premature foaming during firing and the collapse of bubbles before complete curing is achieved.

[0036] Preferably, the pumpable, heat-expandable sealant composition contains, as component e, a liquid rubber functionalized optionally with anhydride functional groups, epoxy functional groups, or acid functional groups, preferably 0.1 to 30% of maleic anhydride functional groups, wherein the liquid rubber is present in an amount of 0.25 to 20% by weight, preferably 0.5% to 10% by weight.

[0037] As is known in the art, curing packages containing sulfur and sulfur accelerators are preferably used for the primary curing of compositions. Additional reactive or crosslinking components disclosed herein include peroxide secondary curing agents and cocrosslinkers. These cocrosslinkers constitute compositions having two or more ethylenically unsaturated sites, preferably α-β unsaturated sites. Some cocrosslinkers contain multiple, for example, three, four, five, or more of these terminal unsaturated sites. By combining different curing agents, the controllability of expansion can be improved.

[0038] The pumpable expandable sealant compositions described herein offer one or more of the significant improvements described above. The present invention discloses a method for significantly improving vertical and reverse sagging resistance without affecting expansion performance, flexibility, and adhesion after cooling. In some embodiments, the present invention enables a wider range of sealing applications requiring the filling of larger gaps by increasing the expansion height. Another aspect of the present invention relates to a formulation that can expand and cure within target firing conditions of 15 minutes at a metal temperature of 140°C while maintaining at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% cohesive failure modes. Another aspect of the present invention relates to moisture resistance that allows the uncured composition to be exposed to high humidity without affecting vertical expansion performance.

[0039] Preferably, the pumpable expandable sealant composition of the present invention completely seals the gap by expanding from the coated panel (e.g., bottom panel) to the opposite side of the cavity to be sealed, before the composition is fully cured, preferably 10%, 20%, 30%, 40%, 50%, 60%, or 70% cured, and reaching and adhering to the opposite metal surface (e.g., top panel).

[0040] In some embodiments, the pumpable expandable sealant compositions of the present invention provide low-temperature expansion, such as 125°C, 130°C, 135°C, or 140°C. Preferred embodiments satisfy the expansion requirement of firing at 140°C for 15 minutes while also satisfying cohesive failure modes in CRS, HDG, EZG, aluminum, and electrodeposited metal panels. In some embodiments, the vertical height expansion in firing at 140°C for 15 minutes exceeds eight times the height of the initially deposited uncured composition film.

[0041] The pumpable expandable sealant composition of the present invention preferably contains a sag-resistant package that does not reduce the vertical expansion height performance. By incorporating natural wax, petroleum-based wax, or synthetic wax, preferably amide wax, and optionally fumed silica, preferably hydrophilic fumed silica, into the uncured sealant composition, the inventors have found that a 10 mm high crescent-shaped bead applied to a metal panel can be prevented from sagging by more than 10% even after being left inverted for more than one day. Other thickeners may also prevent sagging, but they also increase the expansion resistance during the curing process. Therefore, the expansion and wet-out properties of the expandable sealer are limited. The present invention uses a combination of waxes with melting points above 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 110°C, or 120°C, and preferably below 200°C, 180°C, 160°C, 150°C, 140°C, 135°C, or 130°C. In a preferred embodiment, in the molten state, the rheology of the expandable composition remains low enough to provide flexibility and expansion height during the gas generation phase, which occurs in the range of about 130-135°C or higher.

[0042] In some embodiments, the pumpable expandable sealant composition of the present invention further comprises an organic resin such as a polyvinyl chloride (PVC) polymer and / or a PVC copolymer and / or a (meth)acrylate polymer and / or a copolymer that is useful for thickening the composition at a temperature above the Tg point of PVC or (meth)acrylate. The presence of organic oligomers and / or polymers is useful for further controlling sag at temperatures where the wax is completely melted and the sag resistance is not so high. By combining amide wax with PVC and / or acrylate materials, a synergistic balance of viscosity with increasing temperature is obtained and sag resistance is maintained.

[0043] In some embodiments, the pumpable expandable sealant composition of the present invention provides a low solids formulation that reduces the mass of the cured product and contributes to the weight reduction of the vehicle. The low solids formulation may also be useful for maximizing the elongation rate after curing, preventing poor adhesion during cooling, and optionally reducing the application cost. In some embodiments, the density of the uncured pumpable sealant composition may be less than 1.25 g / cm 3 but in a preferred embodiment, the solids content is preferably, in order of preference, 0.90 g / cm 3 , 0.95 g / cm 3 , 1.0 g / cm 3 , 1.10 g / cm 3 , 1.12 g / cm 3 , 1.13 g / cm 3 , 1.14 g / cm 3 or 1.15 g / cm 3 and may be as low as, preferably in order of preference, 1.30 g / cm 3 , 1.28 g / cm 3 , 1.25 g / cm 3 , 1.24 g / cm 3 , 1.22 g / cm 3 , 1.20 g / cm 3 , 1.19 g / cm 3 , 1.18 g / cm 3 , 1.17 g / cm 3 or 1.16 g / cm 3 and may be as high as.

[0044] In some embodiments, the pumpable expandable sealant compositions of the present invention further include a high-temperature resistant package to improve stability. The high-temperature resistant package contains a high-melting-point antioxidant, preferably in an amount exceeding 0.5% by weight of the total mass of the composition. High melting point is understood to mean a MP higher than the activation temperature of the peroxide or other free radical generators (if present) used in the formulation. A typical range may be about 140°C to about 200°C, depending on the baking temperature used in the oven. In preferred embodiments, the high-melting-point antioxidant is present in amounts of at least 0.40% by weight, 0.44% by weight, 0.46% by weight, 0.48% by weight, 0.50% by weight, 0.52% by weight, 0.53% by weight, or 0.54% by weight, with upper limits in preferred order being 1.4% by weight, 1.3% by weight, 1.2% by weight, 1.1% by weight, 1.0% by weight, 0.95% by weight, 0.9% by weight, 0.85% by weight, 0.8% by weight, 0.75% by weight, 0.7% by weight, 0.65% by weight, 0.6% by weight, or 0.55% by weight. In some embodiments, preferred levels are about 0.8% to 1.5% by weight, but higher levels are undesirable for economic reasons. This package may stabilize the vertical height expansion performance of the foam even when exposed to temperatures up to 215°C for 20 minutes without impairing adhesion and expansion performance.

[0045] Conventional methods for applying the pumpable expandable sealant composition of the present invention include bead application and round chip application; however, depending on the processing method, conventional methods may not provide all the advantages of the present invention. In preferred embodiments, to maximize the advantages of the present invention, application is preferably carried out by thin-film spraying or extrusion molding. Preferably, this application method deposits a wider film with a thickness of 0.5 mm to 3 mm, a width of 10 mm to 30 mm, or up to the performance limit of the spray film apparatus for applying a film of uniform thickness. These widths result in a shallower depth and a wider area compared to typical bead application. The advantages of applying a wide thin film are its high resistance to sagging and uniform spread across the entire vertical gap. Another advantage of thin-film deposition is that it uses less material and increases vehicle weight less compared to bead or round chip extrusion molding.

[0046] This disclosure encompasses all products in which any of the compositions of the present invention (pre-cured or partially cured) is applied (but not fully cured), as well as all products including a cured expandable sealant layer bonded thereto. In certain embodiments, the products may be used in the transportation industry, such as aircraft, automobiles, ships, and construction vehicles, using thermosetting methods. In preferred embodiments, the expandable sealant compositions may be used on vehicle parts or components where resistance to noise, vibration, and harshness is required. The surfaces to be sealed are metal surfaces, composite material components, or combinations thereof, and are useful, for example, in automobiles or their components.

[0047] Terms and Abbreviations In this disclosure, the singular forms "a," "an," and "the" also include the plural forms, and references to specific numerical values ​​include at least that specific value unless the context explicitly states otherwise. Thus, for example, a reference to "corrosion inhibitor" refers to one or more corrosion inhibitors and their equivalents known to those skilled in the art, and so on. Furthermore, where an element is indicated as "may be" X, Y, or Z, such usage is not intended to exclude other options for that element in all cases.

[0048] When a value is expressed as an approximation using the notation "approximately," it is understood that the particular value constitutes another embodiment. Generally, the use of the term "approximately" indicates an approximation that may vary depending on the desired characteristic to be obtained by the disclosed subject matter, and should be interpreted based on its function in the particular context in which the term is used. Those skilled in the art will be able to interpret this routinely. If any, all ranges are inclusive and combinable; that is, a reference to a value indicated in a range encompasses all values ​​within that range.

[0049] In this specification, it should be understood that certain features of the Disclosure described in the context of individual embodiments for clarity may be provided in combination in a single embodiment. That is, unless they are obviously incompatible or explicitly excluded, each individual embodiment is considered combinatorial with other embodiments, and such combination constitutes a different embodiment. Conversely, various features of the Disclosure described in the context of a single embodiment for brevity may be provided separately or in any subcombination. Finally, embodiments may be described as part of a series of steps or as part of a more general structure, but each step is considered an independent embodiment and may be combined with other steps.

[0050] The transitional terms “contains,” “essentially consists of,” and “consist of” are intended to imply the meanings commonly accepted in patent terminology. In embodiments provided using the term “essentially consists of,” the basic and novel features are the ease of operation of a method or composition / system for providing a composition exhibiting the claimed functional features using only the described components.

[0051] When a value is expressed as an approximation using the preposition "approximately," it is understood that the particular value may form another embodiment. Generally, the use of the term "approximately" indicates an approximation that may vary depending on the desired properties to be obtained by the disclosed subject matter, and should be interpreted in the specific context in which it is used, based on its function. In some embodiments, "approximately X" (where X is a number) refers to ±10% (inclusive) of the stated value. For example, the phrase "approximately 8" may refer to values ​​(inclusive) from 7.2 to 8.8. This value may also include "exactly 8." If present, all ranges include both ends and are combinable. For example, if the range "1 to 5" is stated, the stated range should be interpreted as optionally including ranges such as "1 to 4," "1 to 3," "1 to 2," "1 to 2 and 4 to 5," "1 to 3 and 5," etc. Furthermore, if a list of choices is explicitly provided, such a list may also include embodiments in which any of the choices are excluded. For example, if a range "1-5" is specified, such a specification can support situations where 1, 2, 3, 4, or 5 is excluded. Therefore, the specification "1-5" may support "1 and 3-5, but not 2," or simply "2 is not included."

[0052] For various reasons, it is preferable that the inventions disclosed herein (e.g., compositions, uncured adhesives, pre-cured adhesives and cured adhesives, methods and products) may be manufactured without certain components, that is, without certain substances, whether added or generated in-situ, except for trace amounts of contaminants, or without or substantially without many of the components used in the prior art as components for similar purposes in compositions. Specifically, independently of each of the preferably minimized components listed below, at least some embodiments of the present invention may contain the following components: epoxy resins, copper, oxidizing agents, e.g., peracids, permanganates, perchlorates, chlorates, chlorites, chlorites, hypochlorites, perborates, hexavalent chromium, trivalent chromium, sulfuric acid and sulfates, nitric acid and nitrate ions; as well as fluorine, formaldehyde, formamide, hydroxylamine, cyanide, cyanate; rare earth metals; boron, e.g., borax, borate; strontium; free halogen ions, e.g., It is increasingly preferable, in the order described, to include an epoxy curing accelerator comprising fluorine, chlorine, bromine or iodine; and / or unsubstituted urea, imidazole, phosphonium ion liquid, an unblocked tertiary amine or a polyamine salt of a blocked tertiary amine polyhydric phenol active at room temperature, or a combination thereof, in an amount of 1.0%, 0.5%, 0.35%, 0.10%, 0.08%, 0.04%, 0.02%, 0.01%, 0.001%, or 0.0002% or less, more preferably in grams per liter, and even more preferably in ppm.

[0053] The present invention will be described in more detail in the following embodiments. These embodiments illustrate preferred embodiments of the present invention and are for illustrative purposes only; they should not be construed as limiting the scope of the appended claims. From the above discussion and these embodiments, those skilled in the art will be able to grasp the essential features of the present invention and make various changes and modifications to the invention to suit various uses and conditions without departing from the spirit and scope of the invention. [Examples]

[0054] Unless otherwise specified, the test compositions were prepared as follows: A masterbatch containing 100 parts by weight of SBR rubber, 75 parts by weight of carbon black, and 50 parts by weight of naphthenic oil was prepared by mechanically mixing the components until homogeneous. Subsequently, the remaining components for each example were mixed into the masterbatch in the amounts shown in the table.

[0055] Performance testing An expansion test was conducted to measure the vertical height change of the thermally expandable sealant. This test method was based on Toyota test methods TSK6527G (6.3.5 expansion rate) and TSK6529G (5.6 expansion rate). The materials used were a 150 × 75 × 0.8 mm oil-coated CRS panel, a panel for applying the uncured composition onto the CRS panel, 9 mm and 13 mm spacer blocks, a 1.5 mm spacer, and 1 inch wide masking tape.

[0056] Unless otherwise noted, the following procedure was used in all examples: An uncured sealer composition was applied to an oil-coated CRS panel (1) to cover a surface area of ​​approximately 100 mm x 75 mm using a drawbar or spacer and known methods such as masking, leaving the panel surface around the cast composition uncoated (see Figure 1). The test composition was cast over the entire panel at a 45-degree angle, and then again in the opposite direction at a 45-degree angle. The surface of the cast layer was inspected for voids. If voids were present, they were eliminated by casting over them. Tape or other masking was carefully removed. The initial height "M" of the uncured sealant composition (2) was recorded. Unless otherwise noted, in all examples, an uncured sealer composition (2) with an initial height "M" of 1.62 mm was cast onto the oil-coated CRS panel (1).

[0057] A pair of 9 mm spacer blocks (3) are placed at adjacent corners on the surface of an oil-coated CRS panel (1) coated with an uncured sealer composition (2), and a pair of 13 mm spacer blocks (4) are placed at the opposite corners of the surface (see Figure 2). An oil-coated top surface CRS panel (1') approximately 100 mm wide x 75 mm x 0.8 mm in size is placed on the spacers, and the panel is secured to the spacers at each corner. It is confirmed that the panel (1') is placed flat and that the gap (5) starts at 9 mm and widens to 13 mm (see Figures 3 and 4). The CRS panel uncured sealer assembly sample is baked in a forced-air circulation oven for the time and peak metal temperature specified in the example. The sample is cooled to room temperature. The position where the expanded cured sealant (6) is in uniform contact with the top surface CRS panel (1') is identified. The maximum gap height (B) is measured at this position, and this corresponds to the expansion thickness "B". The vertical expansion of the sealer was determined using the following formula. Expansion (multiple of M) = Bmm / Mmm

[0058] In one embodiment, the expanded thickness B was measured to be 11.51 mm. The expansion rate in this embodiment was 11.51 mm ÷ 1.62 mm = 7.11 times.

[0059] [Table 1]

[0060] For Example 1, a vertical expansion test was performed as described in this specification. • Target firing results: Vertical expansion 11.0 times, starting film thickness 1.5 mm, maximum gap bridge after firing at 171°C for 20 minutes was 16.5 mm. • Vertical expansion results from low-temperature firing: Vertical expansion was 10.4 times, with a starting film thickness of 1.42 mm. After firing at 171°C for 20 minutes, the maximum gap bridge was 14.63 mm. The following tests were conducted on the uncured, pumpable sealant composition. a. Viscosity result at shear rate of 1 / 20 sec and shear ramp = 753 Pa·s b. Inversion and sagging test: A crescent-shaped bead cast measuring 10mm high x 20mm wide x 100mm long was placed on an oil-coated CRS panel. Results: Inversion and retention for 24 hours = bead height increase of less than 10%

[0061] For Example 2, a vertical expansion test was performed as described in this specification. • Target firing results: Vertical expansion 11.2 times, starting film thickness 1.6 mm, maximum gap bridge after firing at 171°C for 20 minutes was 18.9 mm. • Vertical expansion results after low-temperature firing: Vertical expansion was 9.9 times. With a starting film thickness of 1.5 mm, the maximum gap bridge after firing at a metal temperature of 140°C for 15 minutes was 14.8 mm. This indicates that this formulation meets the low-temperature expansion performance requirements. The following tests were conducted on the uncured, pumpable sealant composition. a. Viscosity result at 23℃, shear rate of 1 / 20 sec, and shear ramp = 679 Pa·s b. Inversion and sagging test conditions described in Example 1 Sagging result: 24-hour inversion retention = bead height increase of less than 10%

[0062] [Table 2]

[0063] [Table 3]

[0064] In Example 5, it was demonstrated that the use of amide wax improved sag resistance without significantly affecting vertical expansion. In Example 4, the use of organic affinity phyllosilicate reduced vertical expansion, but maintained sag resistance. This indicates that increasing the amount of fumed silicon dioxide or other fillers improves sag resistance in the reverse direction, but decreases vertical expansion.

[0065] Those skilled in the art will understand that the above embodiments are merely illustrative examples illustrating the components and performance of the present invention. These embodiments are not intended to limit the present invention to illustrative embodiments.

Claims

1. A pumpable, heat-expandable sealant composition comprising synthetic rubber, PVC homopolymer or copolymer, wax thixotropy agent, foaming agent, optionally functionalized liquid rubber, vulcanizing agent, vulcanization accelerator, and one or more fillers.

2. The composition according to claim 1, wherein the wax thixotropic agent comprises an amide wax, and the composition optionally further comprises fumed silica, preferably hydrophilic fumed silica.

3. The composition according to claim 2, wherein the PVC polymer is a homopolymer present in an amount sufficient to thicken the composition to improve its resistance to sagging after application, while maintaining a pumpable viscosity during application.

4. The composition according to claim 3, wherein the liquid rubber is functionalized with maleic anhydride.

5. The composition according to claim 1, wherein the composition comprises less than 5% by weight of epoxy resin.

6. The composition according to claim 1, further comprising one or more peroxide curing agents, antioxidants, and plasticizers.

7. The composition according to claim 1, further comprising a cocrosslinking agent containing a poly(meth)acrylate functional crosslinking agent having multiple unsaturated moieties.

8. The composition according to claim 7, wherein the cocrosslinking agent comprises a polyacrylate functional crosslinking agent having at least four unsaturated moieties.

9. The composition according to claim 6, further comprising 15 to 55% by weight of a plasticizer.

10. A pumpable, heat-expandable sealant composition comprising SBR rubber, a PVC homopolymer / copolymer and / or acrylic resin powder having a Tg in the range of 50 to 120°C, an amide wax thixotropic agent having a melting point in the range of 80 to 150°C, a foaming agent, a liquid rubber functionalized with maleic anhydride functional groups, epoxy functional groups or acid functional groups, a vulcanizing agent, preferably sulfur, one or more vulcanization accelerators, and at least one filler.

11. a. SBR rubber present in an amount of 5 to 30% by weight, preferably 7 to 20% by weight, most preferably at least 12, 13, 14 or 15% by weight. b. PVC homopolymer / copolymer and / or acrylic resin powder having a Tg preferably in the range of 50°C to 120°C, present in an amount of 2 to 35% by weight, preferably 5 to 30% by weight. c. An amide wax thixotropic agent, preferably having a melting point in the range of 80°C to 150°C, and present in an amount of 0.25% to 5% by weight, preferably about 0.5% to 6% by weight. d. A foaming agent present in an amount of 0.5% to about 15% by weight, preferably 1.0% to 10% by weight (OBSH is preferred, but ADCA including an accelerator package may also be used), e. A liquid rubber optionally functionalized with an anhydride functional group, an epoxy functional group, or an acid functional group, preferably having 0.1 to 30% maleic anhydride functional groups, present in an amount of 0.25 to 20% by weight, preferably 0.5 to 10% by weight. f. Sulfur present in an amount of approximately 0.1% to approximately 4% by weight, preferably 0.2% to 2% by weight. g. A sulfur crosslinking accelerator present in an amount of 0.25 to about 4% by weight, preferably about 0.5% to 5% by weight. h. Plasticizer present in an amount of approximately 15 to 55% by weight, preferably 20 to 50% by weight. i. A filler present in an amount of approximately 1 to 25% by weight, preferably 1 to 20% by weight. j. Preferably an antioxidant having a melting point of 100°C, 110°C, 120°C, 130°C, 140°C, or above 150°C, present in an amount of 0.25 to 1.25% by weight, preferably 0.5 to 1.5% by weight. k. Optionally, the material may contain one or more of fumed silica, peroxide curing agents, and cocrosslinking agents, each present independently in an amount of up to 2.0% by weight. Includes, All of the above amounts are based on the total volume of the composition, for a pumpable, heat-expandable sealant composition.

12. The composition according to claim 11, wherein the peroxide curing agent and the cocrosslinking agent are present in an amount of 0.1 to 2% by weight, the liquid rubber is functionalized with maleic anhydride, and the composition can be cured at a metal temperature of 140°C for about 15 to 20 minutes.

13. a) A step of applying a pumpable, heat-expandable sealant composition according to any one of claims 1 to 12 to a gap in an article, and b) A step of heating the article containing the pumpable, heat-expandable sealant composition to a temperature exceeding the activation temperature of the foaming agent to form an expandable material in the gaps of the article, thereby creating reinforced and / or sealed portions of the gaps in the article. A method for manufacturing articles containing [a certain type of] article.

14. The method according to claim 13, wherein the article is a vehicle part.

15. A component having a metal surface, a composite material surface, or a combination of the said surfaces, An uncured, heat-expandable sealant deposited on a portion of the surface, comprising SBR rubber, PVC homopolymer / copolymer and / or acrylic resin, amide wax, foaming agent, liquid rubber functionalized with maleic anhydride functional groups, epoxy functional groups or acid functional groups, sulfur-containing vulcanizing agent, one or more vulcanization accelerators, and at least one filler, Products containing, A product wherein the sealant is curable within target firing conditions of 15 minutes at a metal temperature of 140°C and exhibits at least 80% cohesive failure modes.

16. The product according to claim 15, wherein the uncured thermally expandable sealant deposited on the surface shows a height increase of less than 10% after a 24-hour inversion residence time.

17. The product according to claim 15, wherein the uncured thermally expandable sealant is capable of expanding vertically to more than eight times its initial height when fired at 140°C for 15 minutes.

18. The product according to claim 15, wherein the product is a part of an aircraft, automobile, ship, or construction vehicle.

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