Assembly and related dispensing method for dispensing polymer foam

Abstract

The present invention relates to an assembly for dispensing a polymer foam, the assembly comprising a pressurized can equipped with a foaming aqueous polymer composition and one or more propellants, and a dispensing gun, wherein the viscosity of the foaming aqueous polymer composition and the flow resistance of the dispensing gun are optimized to achieve a high dispensing yield. The present invention further relates to a method for dispensing a polymer foam using a dispensing gun and related uses of the dispensing gun.

Description

[Technical Field]

[0001] The present invention relates to an assembly for dispensing polymer foam, the assembly comprising a pressurized can containing a foaming aqueous polymer composition and one or more propellants, and a dispensing gun. The present invention further relates to a method for dispensing polymer foam using a dispensing gun and related uses of the dispensing gun. [Background technology]

[0002] Polymer foams are well-known products used in a variety of applications, particularly in the building and construction industries. For example, polymer foams are commonly used as insulation, caulking, or sealants.

[0003] Conventional spray foams are most commonly polyurethane foams. Polyurethanes are typically produced in situ during product application by the reaction of a polyol component and a diisocyanate component (a so-called two-component system), or they are provided as a prepolymer with a reactive isocyanate group that can be moisture-cured (a so-called one-component system). Such products inevitably contain free (reactive) diisocyanates, which may have adverse health effects on users and are therefore under investigation in various countries.

[0004] Aqueous foaming polymer compositions substantially free of reactive groups such as diisocyanates have been developed. For example, U.S. Patent No. 7029609B2 discloses a foaming polymer composition containing an ionic foaming stabilizer. U.S. Patent No. 7179845B2 discloses various foaming polymer compositions containing fatty alcohol micelle-forming agents.

[0005] The main obstacle hindering the widespread adoption of such foamed aqueous polymer compositions lies in the difficulties encountered when such products move from the laboratory to the market environment where they are generally supplied in the form of pressurized cans. The inventors have found that dispensing the same formulation in different ways can result in entirely different foams, considering properties such as dimensional stability, elasticity, post-expansion (foam expansion in the time frame immediately after application), dispensing yield (remaining fraction in the can and filling performance of the joints), and others. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an assembly for dispensing polymer foams and an associated dispensing method that can dispense foamed aqueous polymer compositions, resulting in improved foaming properties such as dimensional stability, elasticity, post-expansion, and / or dispensing yield (measured, for example, according to experimental methods referenced in any part of this specification) compared to known assemblies and methods. [Means for solving the problem]

[0007] The inventors have found that dispensing a foamed aqueous polymer composition from a can using a dispensing gun can be significantly improved by (i) an aqueous polymer composition adjusted to a specific viscosity, (ii) a specific can pressure, and (iii) selecting a specific basket for fluid connection of the can to a dispensing gun having low flow resistance. The flow resistance of such a basket can be determined, for example, by determining the residual can pressure after holding the trigger of the dispensing gun in the fully open position until no more product is dispensed. The residual can pressure is determined by the spring characteristics of the basket using a spring-loaded check valve. By selecting a basket with low flow resistance, as shown in the attached example, a foam exhibiting large post-expansion, not collapsing at lower temperatures (e.g., 5°C), and achieving high dispensing yields is obtained, while yielding a foam with excellent dimensional stability, elasticity, insulation properties, adhesion, and airtightness. The assembly of the present invention has been found to achieve excellent dispensing yield, which not only reflects a small amount of product remaining in the can (and therefore less waste due to disappearance), but also reflects a certain amount of joint space of a predetermined size that can be filled with dispensed product (which reflects a yield for the user).

[0008] Therefore, in the first aspect, the present invention is • A pressurized can containing a foamed aqueous polymer composition and one or more propellants, The present invention provides an assembly for dispensing polymer foam, comprising a dispensing gun including a basket for fluid connection of a can to the dispensing gun, the basket including a flow channel for connecting the can to the dispensing gun, and a blocking means configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, The foamed aqueous polymer composition is heated at 20°C for 100 seconds. -1 The kinematic viscosity is determined according to a viscosity protocol at a shear rate of less than 1.5 Pa·s. The can has an internal relative pressure of at least 100 kPa (1 bar) at 20°C. The blocking means contained in the basket in the open position allows the flow from the pressurized can until the internal relative pressure is less than 120 kPa (1.2 bar) at 20 °C.

[0009] Preferably, the blocking means is a spring-loaded check valve including a spring having a spring constant of less than 1 N / mm.

[0010] In a further aspect, the present invention provides the following steps, namely, (i) providing a pressurized can containing a foaming aqueous polymer composition as described herein and one or more propellants; (ii) providing a dispensing gun as described herein; (iii) attaching the pressurized can to the dispensing gun by fluidly connecting the can to the dispensing gun; (iv) dispensing the polymer composition from the can, thereby obtaining a polymer foam, and provides a method for dispensing a polymer foam.

[0011] In a further aspect, the present invention provides a polymer foam obtainable by the method described herein.

[0012] In a further aspect, the present invention provides the use of a dispensing gun including a basket for fluidly connecting a can to the dispensing gun, the basket including a flow channel for connecting the can to the dispensing gun, and blocking means configured to be movable between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, the blocking means in the open position allowing flow from the pressurized can until the internal relative pressure is less than 120 kPa (1.2 bar) at 20 °C, for dispensing a polymer foam from a pressurized can containing a foaming aqueous polymer composition and one or more propellants, The foaming aqueous polymer composition has a kinematic viscosity determined according to a viscosity protocol at a shear rate of 1.5 Pa·s at 20 °C less than 100 s -1 and the can has an internal relative pressure of at least 100 kPa (1 bar) at 20 °C. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] [Figure 1] Shown is a prior art dispensing gun including a basket for fluidly connecting a can to the dispensing gun, said basket including a spring-loaded check valve.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] As used herein, expressions such as "comprises" and "comprising" and variations thereof should be construed in an open inclusive sense, meaning that the described embodiments include the recited features but do not exclude the presence of other features unless such features render the embodiments inoperable.

[0015] As used herein, expressions such as "one embodiment", "a particular embodiment", "an embodiment" and the like should be construed to mean that a particular feature, structure or characteristic described with respect to the embodiment is included in at least one embodiment. Thus, the appearance of such expressions in various places throughout this specification is not necessarily all referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. For example, a particular feature of the present disclosure described herein in the context of separate embodiments is clearly contemplated as being in a combination in a single embodiment.

[0016] As used herein, the singular forms "a", "an" and "the" should be construed to include plural referents unless the context clearly dictates otherwise. Also note that the term "or" is generally utilized in its broadest sense as meaning "and / or" unless the context clearly dictates otherwise.

[0017] Whenever a compound is referred to as a salt in this document, it should always be interpreted that this includes not only the anhydrous form of the compound but also all solvents (especially the hydrate) unless explicitly indicated otherwise.

[0018] When a compound is mentioned without any stereochemical designation (such as (cis), (trans), (E), (Z), etc.), it includes any stereochemical compound.

[0019] This refers to a substance, component, or raw material that exists immediately before being first contacted, blended, or mixed with one or more other substances, components, or raw materials as disclosed herein. A substance, component, or raw material may acquire identity, properties, or characteristics through chemical reactions or changes during the contact, blending, or mixing process, when carried out in accordance with this disclosure using the common sense and ordinary skills of an average scientist. Unless otherwise specified herein, the definitions of substance, component, or raw material and their relative amounts relate to the composition prepared when the raw materials are first contacted. For example, it is well known to those skilled in the art that end-capturing of a polymer can be produced by contacting a hydroxyl-terminated polymer with a silane crosslinking agent, as described herein. End-capturing is typically performed intentionally by blending the polymer with the crosslinking agent and, optionally, with a catalyst before adding the remaining raw materials. Whenever this disclosure refers to a composition or preparation of a composition comprising a polymer, a crosslinking agent and optionally further raw materials, unless otherwise specified, this expression includes compositions in which the polymer is (end)-encapsulated with the crosslinking agent or the crosslinking agent referred to in the composition. For some polymers (e.g., styrene acrylate), depending on the polymerization method used, functional groups that can react with the crosslinking agent may occur irregularly in the polymer chain, so it should be understood by those skilled in the art that the term “end-encapsulation” should not be understood to strictly refer to reactions at the “ends” of the polymer chain.

[0020] As used herein, the expression "wt.%" refers to the amount of compound containing its counterion when used in the context of ionic compounds (such as ionic surfactants).

[0021] The film formation temperatures referred to herein are determined according to ASTM D2354-10(2018).

[0022] The kinematic viscosity referred to herein is the kinematic viscosity of the aqueous polymer composition before the addition of propellant, and is determined using the following method (hereinafter referred to as the "viscosity protocol"), namely, Using the HR-2 Discovery Hybrid Rheometer (TA Instruments), the method of DIN EN ISO3219 (2021) is applied. The method of Annex B of DIN EN ISO3219(2021) applies, where a 25mm upper rotating stainless steel plate is used in place of a cone plate, combined with a fixed lower Peltier plate. The gap between the plates is 100 microns. The reported viscosity was obtained under the following conditions: temperature 20°C, immersion time 30s, duration 60s, shear rate 100s. -1 This represents the average viscosity measured 15 to 60 seconds from the start of the peak retention test, with a sampling interval of 1.0 s / pt.

[0023] The spring constants referred to herein are preferably determined using a Zwick Z010 tensile test bench with a 200N load cell.

[0024] In the first aspect, the present invention is • A pressurized can containing a foamed aqueous polymer composition and one or more propellants, The present invention provides an assembly for dispensing polymer foam, comprising a dispensing gun including a basket for fluid connection of a can to the dispensing gun, the basket including a flow channel for connecting the can to the dispensing gun, and a blocking means configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, The foamed aqueous polymer composition is heated at 20°C for 100 seconds. -1The kinematic viscosity is determined according to a viscosity protocol at a shear rate of less than 1.5 Pa·s. The can has an internal relative pressure of at least 100 kPa (1 bar) at 20°C. In the open position, the shut-off mechanism contained within the basket allows flow from the pressurized can to an internal relative pressure of less than 120 kPa (1.2 bar) at 20°C.

[0025] Adapting the viscosity of an aqueous polymer composition to satisfy the viscosity characteristics of the present invention is within the scope of the routine skills of those skilled in the art. Viscosity can be adapted, for example, by (a) adapting the amount of polymer in the aqueous polymer composition, (b) adding or adapting the amount of rheological modifier in the aqueous polymer composition, (c) adding or adapting the amount of filler in the aqueous polymer composition, (d) adapting the pH of the aqueous polymer composition, and / or adapting the particle size of the polymer and / or filler in the aqueous polymer composition.

[0026] A foamed aqueous polymer composition is typically an aqueous polymer dispersion.

[0027] The foamed aqueous polymer composition is preferably heated at 20°C for 100 seconds. -1 The kinematic viscosity is determined according to a viscosity protocol at a shear rate of less than 1.2 Pa·s, preferably less than 0.9 Pa·s. In particular, for optimal foam properties and yield (considering both can yield and joint yield), the foamed aqueous polymer composition is prepared at 20°C for 100 seconds. -1 It is preferable to have a kinematic viscosity determined according to a viscosity protocol at a shear rate of less than 0.7 Pa·s, preferably less than 0.6 Pa·s, and most preferably less than 0.5 Pa·s. In some specific preferred embodiments, the foamed aqueous polymer composition is heated at 20°C for 100 seconds. -1 The kinematic viscosity is determined according to a viscosity protocol at a shear rate of less than 0.4 Pa·s or less than 0.280 Pa·s. In all embodiments described herein, the foamed aqueous polymer composition is preferably heated at 20°C for 100 seconds. -1The kinematic viscosity is determined according to a viscosity protocol at a shear rate of at least 0.05 Pa·s, preferably at least 0.1 Pa·s.

[0028] Typically, a can has an internal relative pressure of less than 1200 kPa (12 bar) at 50°C. A can preferably has an internal relative pressure of at least 200 kPa (2 bar), more preferably at least 300 kPa (3 bar), and most preferably at least 400 kPa (4 bar) at 20°C. A can preferably has an internal relative pressure in the range of 100 to 1000 kPa (1 to 10 bar), more preferably in the range of 300 to 700 kPa (3 to 7 bar), more preferably in the range of 400 to 600 kPa (4 to 6 bar), specifically in the range of 450 to 550 kPa (4.5 to 5.5 bar) at 20°C.

[0029] According to the present invention, the can includes a valve (typically called an aerosol valve) configured to open when the can is connected to a dispensing gun.

[0030] The flow resistance of a basket for fluid connection of a can to a dispensing gun is typically determined by a shutoff mechanism, which is typically located inside the flow channel. Even in the open position, the shutoff mechanism (e.g., a spring-loaded check valve) is typically still present within the flow channel, and the product flows between the shutoff mechanism and the wall of the flow channel, such that the shutoff mechanism is a determinant of the overall flow resistance of the basket. In a preferred embodiment of the present invention, the values ​​provided herein for the flow resistance of the shutoff mechanism, in particular the internal can pressure that allows the shutoff mechanism to flow, are also provided as a preferred embodiment for the overall flow resistance of the basket.

[0031] The flow resistance of the shut-off means contained within the basket in the open position according to the present invention is such that the shut-off means is provided to allow flow from the pressurized can until the internal relative pressure is less than 120 kPa (1.2 bar) at 20°C. In a preferred embodiment, the flow resistance is determined by connecting the pressurized can to a dispensing gun, keeping the trigger in the fully open position until no more product is dispensed, and then determining the residual internal relative pressure of the can at 20°C after dispensing. The flow resistance according to the present invention is measured at the shut-off means in the open position. As will be understood by those skilled in the art, when a spring-loaded check valve is used, the valve moves automatically from the closed position to the open position depending on the pressure of the can connected to the basket, and the flow resistance is such that the internal pressure of the can cannot exceed the force applied by the spring so that the flow channel is closed.

[0032] In preferred embodiments of the present invention, the shut-off means contained within the basket in the open position allows flow from the pressurized can to an internal relative pressure of less than 100 kPa (1 bar), preferably less than 80 kPa (0.8 bar), at 20°C. As shown in the attached example, it has been found that flow resistance can be obtained that allows dispensing down to a can pressure as low as 50 kPa (0.5 bar). Therefore, in some embodiments of the present invention, the shut-off means contained within the basket in the open position allows flow from the pressurized can to an internal relative pressure in the range of 50 to 120 kPa (0.5 to 1.2 bar), preferably in the range of 50 to 100 kPa (0.5 to 1 bar), more preferably in the range of 50 to 80 kPa (0.5 to 0.8 bar), at 20°C.

[0033] A very preferred embodiment of a shut-off means suitable for use in a basket described herein is a spring-loaded check valve. Dispensing guns including a basket equipped with a spring-loaded check valve are known to those skilled in the art. Check valves are also called backflow prevention valves, limiting valves, or one-way valves. The spring-loaded check valve is preferably a ball-spring check valve. A ball-spring check valve functions such that when a can is connected to the gun, the pressure provided by the can compresses a spring by applying a force on the ball, thereby opening a fluid passage from the can to the dispensing gun. As the can is emptied and the pressure drops, the spring expands and eventually closes the gun barrel, thus allowing for clean connection and disconnection of the can. Thus, it will be understood by those skilled in the art that the spring in a spring-loaded check valve is provided to control the movement of the valve closing means (e.g., the ball in a ball-spring check valve). A spring-loaded check valve, such as those referenced in the different embodiments of the present invention described herein, has a spring constant of less than 1 N / mm, preferably less than 0.4 N / mm, and more preferably less than 0.1 N / mm. For example, in some embodiments of the different embodiments of the present invention described herein, the spring constant is less than 0.08 N / mm, less than 0.06 N / mm, or less than 0.05 N / mm.

[0034] A spring-loaded check valve may include a second spring having a spring constant greater than 1.5 N / mm, preferably greater than 2.5 N / mm, more preferably greater than 3.2 N / mm, which is coaxial with a first spring having a spring constant less than 1 N / mm, preferably less than 0.4 N / mm, more preferably less than 0.1 N / mm, and the first spring extends coaxially beyond the second spring in at least one direction, so that the movement of the valve closing mechanism (e.g., the ball in a ball-spring check valve) is initially controlled independently by the first spring when the can is connected to the basket, but after the valve closing mechanism encounters the second spring, the first spring collapses completely. This prevents the passage to the dispensing gun from being completely blocked when the can pressure is high, for example when coupled to a new, full can.

[0035] Preferred embodiments of alternative shutoff means suitable for use in the baskets described herein are as described in Chinese Patent Application Publication No. 113798081A, which is incorporated herein by reference. Specifically, a basket like the one described in Figure 2 and paragraphs

[0030] to

[0041] of Chinese Patent Application Publication No. 113798081A is incorporated herein by reference. Generally, in preferred embodiments of the present invention, the basket includes an elongated flow channel connecting a can to a dispensing gun, and comprises a shutoff means including a pin-like structure positioned inside the flow channel, configured to move axially within the flow channel between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, the position of the pin-like structure inside the flow channel is preferably controlled by a rotational movement such as the rotation of part or all of the basket.

[0036] In all embodiments of the present invention, the dispensing gun typically further includes a handle for holding the gun, a dispensing tube equipped with a dosing nozzle, means for opening and closing the dosing nozzle, and a trigger for activating the means to open the dosing nozzle and dispense polymer foam from a dispensing opening at the end of the dispensing tube. The means for opening and closing the dosing nozzle typically includes a spring-loaded needle that can move coaxially within the dispensing tube, and optionally further includes an adjusting means for adjusting the degree of opening of the outlet of the dosing nozzle, such as a reverse thread. It will be understood by those skilled in the art that when the dosing nozzle is opened to dispense polymer foam, a fluid passage opens up, from the can through the dosing nozzle through the basket, and to the dispensing tube that opens to the environment.

[0037] Figure 1 shows an example of a prior art dispensing gun (1) including a basket (2) for fluid connection of a can to the dispensing gun, the basket (2) including a spring-loaded check valve (not shown). The gun further includes a dispensing tube (3) with a dosing nozzle (not shown) placed inside the gun's dispensing tube (3), a spring-loaded needle (4) that can move coaxially within the dispensing tube for opening and closing the dosing nozzle, and a trigger (5) for activating the spring-loaded needle (4) to open the dosing nozzle and dispense polymer foam through a dispensing opening (6). The gun further includes a reverse thread (7) for adjusting the degree of opening of the outlet of the dosing nozzle and a handle (8) for holding the gun.

[0038] In some embodiments of the present invention, the dispensing gun further includes a spray adapter that is detachably mounted on the dispensing opening of the dispensing tube and is suitable for adapting the spray pattern of polymer foam from the dispensing tube. In a particularly preferred embodiment, the spray adapter is suitable for widening the spray pattern of polymer foam from the dispensing tube. As a result, larger surfaces (e.g., walls) can be insulated more easily. Such spray adapters suitable for widening the spray pattern of polymer foam are known to those skilled in the art and typically include an oval-shaped adapter dispensing opening, and may provide further means for influencing the spray pattern, such as one or more walls extending adjacent to the spray opening. The inventors have found that the assembly of the present invention is particularly beneficial in preventing sputtering when using a wide-angle spray adapter.

[0039] Considering the fact that isocyanate groups react with water, foamed aqueous polymer compositions are substantially free of isocyanate groups.

[0040] The foamed aqueous polymer composition preferably contains less than 5 wt.% (relative to the total weight of the foamed aqueous polymer composition) of monomer, preferably less than 1 wt.%, and more preferably less than 0.1 wt.%. The monomer is preferably a type of monomer contained in the polymer in a polymerized form. Therefore, the foamed aqueous polymer composition preferably contains less than 5 wt.% (relative to the total weight of the foamed aqueous polymer composition) of monomer of the type contained in the polymer in a polymerized form. For example, if the polymer contains polystyrene, the foamed aqueous polymer composition preferably contains less than 5 wt.% (relative to the total weight of the foamed aqueous polymer composition) of styrene monomer. In particularly preferred embodiments, the monomer described herein is present in the foamed aqueous polymer composition in an amount of less than 0.05 wt.% (relative to the total weight of the foamed aqueous polymer composition), preferably less than 0.01 wt.%.

[0041] The ratio (w / w) of the foaming aqueous polymer composition to one or more propellants is typically in the range of 70:30 to 99.5:0.5, preferably in the range of 80:20 to 99.5:0.5, more preferably in the range of 90:10 to 99.5:0.5, for example 92:8 to 99.5:0.5. For example, the ratio (w / w) of the foaming aqueous polymer composition to one or more propellants can be in the range of 70:30 to 99.2:0.8, preferably in the range of 80:20 to 99.2:0.8, more preferably in the range of 90:10 to 99.2:0.8, for example 92:8 to 99:1. When the propellant is in liquid form (typically liquefied due to high can pressure) and is contained in the can, for the purposes of the present invention (especially for determining the ratio (w / w) of the foaming aqueous polymer composition to one or more propellants), such a liquid propellant is considered to be part of the propellant rather than part of the foaming aqueous polymer composition. In some embodiments of the present invention, the ratio (w / w) of the foaming aqueous polymer composition to one or more propellants is in the range of 80:20 to 98:2, preferably in the range of 90:10 to 98:3, more preferably in the range of 92:8 to 97:4. In other embodiments of the present invention, the ratio (w / w) of the foaming aqueous polymer composition to one or more propellants is in the range of 90:10 to 99.5:0.5, preferably in the range of 95:5 to 99.2:0.8, more preferably in the range of 97:3 to 99.2:0.8, for example in the range of 97.5:2.5 to 99:1. In these latter embodiments, the inventors have found that the hardness and dimensional stability are further improved still.

[0042] As will be understood by those skilled in the art from the above embodiments, in a preferred embodiment of the present invention, · The foaming aqueous polymer composition has a kinematic viscosity determined according to a viscosity protocol where the shear rate at 20 °C for 100 s -1 is in the range of 0.05 to 1.2 Pa·s, preferably in the range of 0.1 to 0.9 Pa·s. The ratio (w / w) of the foamed aqueous polymer composition to one or more propellants is in the range of 70:30 to 99.5:0.5, preferably in the range of 80:20 to 99.5:0.5, more preferably in the range of 90:10 to 99.5:0.5, for example, 92:8 to 99.5:0.5.

[0043] In some embodiments of the present invention, • The foamed aqueous polymer composition was heated to 20°C for 100 seconds. -1 The shear rate has a kinematic viscosity determined according to a viscosity protocol in the range of 0.05 to 1.2 Pa·s, preferably in the range of 0.1 to 0.9 Pa·s. The ratio (w / w) of the foamed aqueous polymer composition to one or more propellants is in the range of 95:5 to 99.2:0.8, more preferably in the range of 97:3 to 99.2:0.8, for example, in the range of 97.5:2.5 to 99:1. Preferably, • The foamed aqueous polymer composition was heated to 20°C for 100 seconds. -1 The shear rate has a kinematic viscosity determined according to a viscosity protocol in the range of 0.1 to 1 Pa·s, preferably in the range of 0.1 to 0.75 Pa·s, most preferably in the range of 0.2 to 0.55 Pa·s. The ratio (w / w) of the foamed aqueous polymer composition to one or more propellants is in the range of 95:5 to 99.2:0.8, more preferably in the range of 97:3 to 99.2:0.8, for example, in the range of 97.5:2.5 to 99:1.

[0044] For general applications, the foamed aqueous polymer composition preferably has a minimum film-forming temperature of less than 25°C.

[0045] The foamed aqueous polymer composition preferably contains at least 20 wt.% of polymer (relative to the total weight of the foamed aqueous polymer composition), preferably at least 30 wt.% of polymer, and most preferably at least 40 wt.% of polymer. The foamed aqueous polymer composition preferably contains at most 80 wt.% of polymer (relative to the total weight of the foamed aqueous polymer composition), preferably at most 70 wt.% of polymer, and most preferably at least 65 wt.%. The inventors have found that such polymer compositions are suitable for the context of the present invention in order to obtain not only the excellent foam properties previously described herein but also yield (both can yield and joint yield). When using a low polymer content, it is preferable to include other materials (such as fillers) so that the aqueous polymer composition has a sufficiently high solids content to promote drying / film formation after coating. Therefore, in all embodiments of the present invention described herein, the foamed aqueous polymer composition preferably has a solids content of at least 30 wt.% (relative to the total weight of the foamed aqueous polymer composition), preferably at least 40 wt.%, and more preferably at least 45 wt.%. The solids content as referred herein relates to the solids content determined by gravimetric measurement, in which a 1-2 g dispensing is weighed, subsequently dried at 120°C in an air-circulating oven until a certain mass is reached, and the resulting residue is weighed again to calculate the total solids content. The water content is preferably at most 70 wt.% (relative to the total weight of the aqueous polymer composition), preferably at most 60 wt.%, and more preferably at most 55 wt.%. The water content is preferably at least 25 wt.%, more preferably at least 35 wt.%, and most preferably at least 40 wt.%. The water content can be appropriately determined using Karl Fischer titration.

[0046] The foamed aqueous polymer composition preferably contains a polymer selected from the group consisting of polyurethane, polyacrylate, polyurethane acrylate copolymer, polyalkyl acrylate, polystyrene, styrene acrylate copolymer, polyisocyanurate, polyvinyl acetate, vinyl acetate alkylene copolymer, styrene alkyldiene copolymer, copolymers thereof, and combinations thereof. It is highly preferable that the foamed aqueous polymer composition contains a polymer selected from the group consisting of polyurethane, polyacrylate, polyurethane acrylate copolymer, copolymers thereof, and combinations thereof, most preferably polyurethane or its copolymer. As will be understood by those skilled in the art, the main chain and / or side chains of the polymer may be further chemically functionalized or derivatized, for example, by crosslinking agents or by immobilization of functional molecules such as antimicrobial agents.

[0047] In some embodiments, the polyurethane contains carboxylic acid groups in the form of free acids and / or carboxylate salts. Such polyurethanes can be obtained by including a portion of a carboxylic acid-containing monomer (typically a diol further containing carboxylic acid functionality, such as dimethylolpropionic acid) during polymerization and optionally converting the carboxylic acid groups to carboxylate salts with an amine such as triethylamine. The resulting salts have good water solubility. Similarly, the incorporation of sulfonic acids or sulfonic acid bases, or phosphonic acids or phosphonic acid bases can also be used. For example, mono and dihydroxycarboxylic acids or carboxylate salts, mono and dihydroxysulfonic acids or sulfonates, or mono and dihydroxyphosphonic acids or phosphoates may be suitable. Alternatively, mono and diaminocarboxylic acids or carboxylate salts, mono and diaminosulfonic acids or sulfonates, or mono and diaminophosphonic acids or phosphoates may also be suitable.

[0048] Therefore, the foamed aqueous polymer composition preferably contains 20 to 80 wt.% (relative to the total weight of the aqueous polymer composition), more preferably 30 to 70 wt.%, and most preferably 40 to 65 wt.%, of a polymer selected from the group consisting of polyurethane, polyacrylate, polyurethane acrylate copolymer, polyalkyl acrylate, polystyrene, styrene acrylate copolymer, polyisocyanurate, polyvinyl acetate, vinyl acetate alkylene copolymer, styrene alkyldiene copolymer, their copolymers, and combinations thereof. The polymer is preferably selected from the group consisting of polyurethane, polyacrylate, polyurethane acrylate copolymer, their copolymers, and combinations thereof, and most preferably polyurethane or its copolymer.

[0049] The one or more propellants contained in the pressurized vessel may be any suitable propellants known in the art. The one or more propellants are preferably selected from the group consisting of C1-C4 saturated or unsaturated hydrocarbons (e.g., n-pentane, n-butane, isobutane, n-hexane, 2-methylbutane, propane, 1-pentane, butene, 2-methyl-2-butene, cyclobutane, cyclopentane, cyclohexane), vinyl chloride, methyl chloride, chlorofluorocarbons, hydrochlorofluorocarbons, hydrohaloolefins, air, carbon dioxide, argon, nitrogen, nitrous oxide, dimethyl ether, diethyl ether, dimethoxymethane, methyl formate, and combinations thereof. Preferably, one or more propellants are 1,3,3,3-tetrafluoropropene (HFO 1234ze), 2,3,3,3-tetrafluoroprop-1-ene (HFO 1234yf), 1,1,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene (HFO 1225ye), 3,3,3-trifluoropropene, 1,1,3,3,3-pentafluoropropene (HFO 1225zc), 1,1,2,3,3-pentafluoropropene (HFO 1225yc), (Z)-1,1,1,2,3-pentafluoropropene (HFO 1225yez), and trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO The propellants are selected from the group consisting of 1336mzz(E), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz), 1-chloro-3,3,3,-trifluoropropene (HFO-1233zd), n-butane, isobutane, propane, dimethyl ether, and combinations thereof. More preferably, one or more propellants are selected from the group consisting of 1,3,3,3-tetrafluoropropene (HFO 1234ze), n-butane, isobutane, propane, dimethyl ether, and combinations thereof. In all embodiments described herein, 1,3,3,3-tetrafluoropropene (HFO 1234ze) is preferably HFO 1234ze(E).

[0050] The inventors have found that when a combination of butane (such as isobutane and / or n-butane) and propane is used as a propellant, improvements in foam properties such as dimensional stability, elasticity, post-expansion, and / or yield (yield of can and joint) are achieved. Therefore, the propellant contained in the pressurized can described herein preferably includes or consists of a combination of isobutane and propane. In such embodiments, the ratio (w:w) of butane (such as isobutane and / or n-butane) to propane is preferably in the range of 5:1 to 1:1, and preferably in the range of 3:1 to 1.8:1.

[0051] The foamed aqueous polymer composition may further contain one or more additives selected from the group consisting of film-forming agents, dispensing agents, pH adjusters, fillers, flame retardants, surfactants, thickeners, crosslinking agents, adhesion enhancers, biocides (e.g., fungicides or algaecides), colorants, and the like. The total amount of additives (calculated as the total amount of components excluding water and any polymer) is typically less than 40 wt.% (relative to the total weight of the aqueous polymer composition), for example less than 30 wt.%, less than 25 wt.%, or even less than 15 wt.%.

[0052] Any film-forming agent known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable film-forming agents include polyvinylpyrrolidone (PVP), texanol, propylene glycol, di(propylene glycol) methyl ether, and diisobutyl dicarboxylic acid.

[0053] Any dispensing agent known in the art may be used in the foamed aqueous polymer compositions described herein. An example of a suitable dispensing agent is carboxylated polyacrylate.

[0054] Any pH adjuster known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable pH adjusters include ammonia, alkylamines, strong acids, and strong bases.

[0055] Any filler known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable fillers include inorganic fillers, metal oxide fillers, fly ash, bottom ash, carbon black, glass, and combinations thereof. For example, aluminum silicate, aluminum hydroxide, fumed silica calcium silicate, magnesium silicate, dolomite, calcium carbonate, barium sulfate, calcium sulfate, glass fibers, hollow glass microparticles, carbon black, chalk, titanium dioxide, zinc oxide, siloxane, and / or silica. The filler may have a modified surface. Surface modification of fillers is known to those skilled in the art. Preferred surface modifications include surface treatment with fatty acids (e.g., stearic acid) or silanes (e.g., alkoxysilanes).

[0056] Any flame retardant known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable flame retardants include tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate, tris(1-chloro-2-propyl)phosphate, tris(2,3-dibromopropyl)phosphate, tris(1,3-dichloropropyl)phosphate, tri(2-chloroisopropyl)phosphate, tricresyl phosphate, tri(2,2-dicloisopropyl)phosphate, diethyl N,N-bis(2-hydroxyethyl)aminomethylphosphonic acid, dimethylmethylphosphonic acid, tri(2,3-dibromopropyl)phosphate, tri(1,3-dichloropropyl)phosphate, tetrakis-(2-chloroethyl)ethylenediphosphate, triethyl phosphate, diammonium phosphate, antimony oxide, aluminum trihydrate, polyvinyl chloride, melamine, tribromoneopentyl alcohol, tris(1-chloro-2-propyl)phosphate, triethyl phosphate, ammonium polyphosphate, aluminum hydroxide, borates, and combinations thereof.

[0057] Any surfactant known in the art, including anionic, cationic, nonionic, and zwitterionic surfactants, may be used in the foaming aqueous polymer compositions described herein. Surfactants can function, for example, as emulsifiers, wetting agents, and foaming agents. Suitable examples of nonionic surfactants include ethoxylated alkylphenols (e.g., ethoxylated octylphenol (TRITON® X series) or ethoxylated nonylphenol (TERGITOL® NP series)), glycol distearate, glycol stearate, lanolin esters, lanolin alcohols, ethoxylated fatty alcohols (TERGITOL® TMN and 15-S series), fatty alcohols, polysorbates, polyoxyalkylene ethers, and silicone surfactants (e.g., polysiloxane polyoxyalkylene block copolymers, Hydropalat® WE series). Examples of suitable anionic surfactants include anionic sulfates, carboxylates (e.g., ammonium stearate, potassium oleate), sulfonates (e.g., sodium lauryl sulfate), sacrosinates, phosphates, phosphonates, sulfated fatty alcohol ethoxylates (e.g., Disponil® FES-32 from Cognis Corp.), dodecylbenzenesulfonates (e.g., Rhodacal® DS-4 from Rhodia Corp.), sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-70 from Cytec Industries), monoalkylene sulfosuccinate, fatty alcohol polyglycol ether sulfates, and ammonium salts of alkylethoxylate phosphates (e.g., Rhodia This includes Rhodacal® RS-610 manufactured by Corp. Examples of suitable cationic surfactants include benzalkonium salts, alkyltrimethylammonium salts (e.g., Empigen® CM), and alkyldimethylbenzylammonium salts (e.g., Empigen® BAC50, Servamine® KAC422D, Ninox® 4002). Examples of suitable zwitterionic surfactants include phospholipids (e.g., lecithin), fatty acid amphoacetic acid, and betaine.Preferably, the surfactant is selected from the group consisting of anionic surfactants, nonionic surfactants, and combinations thereof. More preferably, the surfactant is a silicone surfactant such as polysiloxane polyoxyalkylene block copolymer, or a stearic acid such as ammonium stearate. In the embodiment, the surfactant is a silicone surfactant selected from the group consisting of Momentive's L-5130, L-5180, L-5340, L-5440, L-6100, L-6900, L-6980 and L-6988, Air Products' DC-193, DC-197, DC-5582 and DC-5598, and Goldschmidt AG of Essen, Germany's B-8404, B-8407, B-8409 and B-8462. Other examples are disclosed in U.S. Patent Nos. 2,834,748, 2,917,480, 2,846,458, and 4,147,847. In the embodiments, the surfactant is sterianic acid, preferably ammonium stearate.

[0058] Any thickener known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable thickeners include polyurethane thickeners (e.g., Rheovis 1190, Tafigel® PUR40, Tafigel® PUR55), fumed silica (e.g., Aerosil R974), cellulose derivatives (e.g., Methocel® 228, Methocel® A, Methocel® 311), acrylic acid thickeners (e.g., Rheovis HS1169, AP1 / 1, Mirox AM), bentonite, hectorite, montmorillonite, and silicic acid (e.g., Aerosil® 200).

[0059] Any crosslinking agent known in the art may be used in the foamed aqueous polymer compositions described herein. The appropriate crosslinking agent naturally depends on the polymer used. Organosilanes are useful crosslinking agents (e.g., Coatosil MP200), as are ammonium zirconium compounds such as Halox XTAIN L-44. Examples of preferred organosilane crosslinking agents by formula (I) and its hydrolysis or concentrated product are: (R 1 -O) a -Si-(R 2 ) b (I) And, In the formula, a is 3 or 4, b is either 1 or 0. a+b is 4, R 1 Each generation is, individually, hydrogen, C1-C8 alkyl, C1-C8 haloalkyl, C1-C8 aminoalkyl, C2-C8 alkenyl, C3-C8 cycloalkyl, C4-C8 cycloalkenyl, C6-C 10 Allyl, -C(O)R 3 -N=CR 4 R 5 and -N=CR 6 Selected from the group consisting of, R 3 , R 4 and R 5 It is selected from the group consisting of C1-C4 alkyl groups, R 6 Since it is a divalent C2-C8 alkyl group, -N=CR 6 It is a cycloalkyl, R 2 This is selected from the group consisting of hydrogen and optionally substituted monovalent hydrocarbon radicals having 1 to 30 carbon atoms.

[0060] Any adhesion enhancer known in the art may be used in the foamed aqueous polymer compositions described herein. Examples of suitable adhesion enhancers are organosilane adhesion enhancers selected from the group consisting of aminosilanes, alkoxysilanes, and epoxysilanes, preferably aminoalkyltrialkoxysilanes, aminoalkylalkyldialkoxysilanes, bis(alkyltrialkoxysilyl)amines, tris(alkyltrialkoxysilyl)amines, tris(alkyltrialkoxysilyl)cyanurates, tris(alkyl-trialkoxy-silyl)isocyanurates, alkoxy-terminated polydimethylsiloxanes containing aminoalkyl side chains (such as epoxy-terminated (3-aminopropyl)(methyl)polysiloxanes), hydroxy-terminated polydimethylsiloxanes terminated with N-(3-trimethoxylyl)propylcyclohexaneamine, condensates of any enumerated silanes, and combinations thereof. Preferably, the alkyl group is C1-C4 alkyl and the alkoxy group is C1-C4 alkoxy. Embodiments of the present invention include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltriacetoxysilane, N-(3-trimethoxysilylpropyl)diethylene-triamine, bis-(3-methoxysilylpropyl)-amine, aminoethylaminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyldimethoxymethylsilane, and N-(n-butyl)-3-amino The aqueous polymer compositions described herein are provided, further comprising an adhesion enhancer selected from the group consisting of propyltrimethoxysilane, N-(n-butyl)-3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, aminoethylaminotrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, gamma-ureidopropyltrimethoxysilane, 3-aminopropyl(methyl)silsesquioxane, condensates thereof, and combinations thereof.Highly preferred adhesion enhancers are epoxysilanes such as 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane, their condensates, and combinations thereof.

[0061] Any colorants known in the art may be used in the foaming aqueous polymer compositions described herein. Suitable colorants include titanium dioxide, zinc oxide, iron oxide, antimony oxide, chromium green, chromium yellow, iron blue sienna, orange molybdate, and organic pigments such as para red, benzidine yellow, toluidine red, toner, and phthalocyanine, preferably reactive polymers with chromophores.

[0062] A single additive may perform multiple functions; for example, silanes can be used as crosslinking agents and adhesion enhancers, as will be understood by those skilled in the art. Generally, the foamed aqueous polymer compositions described herein are generally preferred to contain additives selected from aminosilanes, epoxysilanes, their condensates and combinations thereof, such as 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane, their condensates and combinations thereof.

[0063] In another embodiment, the present invention relates to the following steps, namely (i) To provide a pressurized can comprising a foaming aqueous polymer composition as described herein and one or more propellants, (ii) To provide a dispensing gun as described herein, (iii) By fluid connection of the can to the dispensing gun, the pressurized can is attached to the dispensing gun, (iv) A method for dispensing a polymer foam is provided, comprising dispensing a polymer composition from a can to obtain a polymer foam.

[0064] Step (iv) is carried out at an ambient temperature of preferably at least 0°C, preferably at least 15°C, and preferably at most 40°C, preferably at most 35°C. Step (iv) is carried out at an ambient relative humidity of preferably less than 80%.

[0065] As shown in the attached example, the inventors have found that the assembly of the present invention can achieve excellent foaming properties. Therefore, the polymer foam obtained in step (iv) preferably has one or more of the following properties, namely: • Post-expansion of at least 15%, preferably at least 25%, as determined according to Method EN17333-2(2020) • Dimensional change of less than 10%, preferably less than 5%, as determined according to Method EN17333-2(2020) • A change in tensile strength of less than 10%, preferably less than 5%, after 1000 cycles of 10% compression and elongation according to Method EN17333-4(2020), and / or • 0.05 W / m² determined in accordance with DIN EN12667:2001 * Less than K, preferably 0.04 W / m * This is a polyurethane foam having a thermal conductivity of less than K.

[0066] The method of the present invention is particularly well suited to providing an airtight seal, which is usually difficult to achieve with aqueous polymer compositions. Therefore, in embodiments, the method described herein is a method for providing an airtight seal. The method of the present invention, in particular a method for providing an airtight seal, preferably comprises (a) depositing a polymer foam around a door frame, such as an interior door frame of a building, or (b) depositing a polymer foam between adjacent parts or layers of a drywall.

[0067] In some embodiments of the methods described herein, the dispensing gun further includes a spray adapter, such as one described herein, which is pre-mounted on the gun, and the polymer composition is dispensed through the spray adapter.

[0068] The assembly and related methods of the present invention can achieve very high yields (both can yield and joint yield), meaning that there is little residue left in the can after the contents have been completely dispensed, resulting in less waste, while allowing for the filling of a large number of joints of a given size, resulting in a user-beneficial yield. In preferred embodiments, the method described herein results in less than 15 wt.% residue remaining in the can after the polymer composition has been maximally dispensed from the can, with 100 wt.% residue corresponding to the total amount of foamed aqueous polymer composition and propellant in the can before any polymer composition has been dispensed from the can. Preferably, less than 12 wt.% residue remains in the can, and more preferably less than 10 wt.% residue remains in the can. Maximum dispensing of the polymer composition from the can means that the normal operation of the dispensing gun will not release any more product from the can. In practice, this means that operating the trigger of the dispensing gun will no longer dispense the contents of the can. A convenient method for determining the wt.% of the remaining residue is to fill a can of known weight with a known amount of aqueous polymer dispenser and propellant, connect the can to a dispense gun, activate the trigger until no more product is dispensed (thus reaching the maximum dispensing limit of the polymer composition from the can), weigh the empty can, determine the weight of the remaining residue, and thereby calculate the wt.% of the residue (100 wt.% is the total amount of foamed aqueous polymer composition and propellant in the can before dispensing).

[0069] In another embodiment, the present invention provides a polymer foam obtainable by the method described herein.

[0070] In another embodiment, the present invention has one or more of the following characteristics, namely, • Post-expansion of at least 15%, preferably at least 25%, as determined according to Method EN17333-2(2020) • Dimensional change of less than 10%, preferably less than 5%, as determined according to Method EN17333-2(2020) • A change in tensile strength of less than 10%, preferably less than 5%, after 1000 cycles of 10% compression and elongation according to Method EN17333-4(2020), and / or • 0.05 W / m² determined in accordance with DIN EN12667:2001 * Less than K, preferably 0.04 W / m * The present invention provides a polymer foam obtainable from a foamed aqueous polymer composition having a thermal conductivity of less than K.

[0071] In another embodiment, the present invention provides the use of a dispenser gun including a basket for fluid connection of a can to the dispenser gun, the basket including a spring-loaded check valve, the spring of the spring-loaded check valve having a spring constant of less than 1 N / mm, the basket including a flow channel connecting the can to the dispenser gun, and a shut-off means configured to move between an open position allowing flow from the can to the dispenser gun and a closed position blocking flow from the can through the flow channel to the dispenser gun, the shut-off means in the open position allowing flow from the can having an internal relative pressure of 120 kPa (1.2 bar) at 20°C, To dispense polymer foam from a pressurized can containing a foaming aqueous polymer composition and one or more propellants, The foamed aqueous polymer composition is heated at 20°C for 100 seconds. -1 The kinematic viscosity is determined according to a viscosity protocol at a shear rate of less than 1.5 Pa·s. The can has an internal relative pressure of at least 100 kPa (1 bar) at 20°C.

[0072] The embodiments described herein earlier with respect to dispensing guns, the properties and compositions of aqueous polymer compositions, and propellants are all equally applicable to the use of the present invention. [Examples]

[0073] Several polyurethane polymer compositions containing different amounts of film-forming agents were prepared. The compositions are shown in the table below (unless otherwise indicated, the units of measurement are grams).

[0074] Before adding the propellant, the kinematic viscosity of the aqueous polymer composition was determined according to the viscosity protocol.

[0075] The pressurized canister was connected to three different dispensing guns for testing. After dispensing as much product as possible using the dispensing gun triggers, the wt.% of the residue remaining in the canister was recorded (100 wt.% corresponds to the total 490.5 g of aqueous polymer composition and propellant loaded into the canister before dispensing).

[0076] Gun A: A dispensing gun equipped with a basket having a ball spring check valve, having two coaxial springs: a first spring with a spring constant of 0.0407 N / mm and a second spring with a higher spring constant. The first spring is larger than the second spring so as to extend coaxially beyond the second spring. As a result, when a can is connected to the basket, the movement of the ball is initially controlled independently by the first spring, but the ball encounters the second spring before the first spring completely collapses. The flow resistance by the basket was determined by connecting the pressurized can of Example 1 to the dispensing gun and keeping the trigger in the fully open position until no more product was dispensed. The residual pressure inside the can was then measured. The basket of gun A allows flow from the pressurized can until the internal relative pressure reaches approximately 70 kPa (0.7 bar) or higher at 20°C.

[0077] Gun B: A cleaning-free, single-component, expandable PU foam gun CY-099T-S of model PU FOAM, available from ZHEJIANG CHAOYU TOOLS CO LTD, is a dispensing gun utilizing a basket as described in Chinese Patent Application Publication No. 113798081A. The basket includes an elongated flow channel connecting a can to the dispensing gun and comprises a blocking means including a pin-like structure placed inside the flow channel, configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, the position of the pin-like structure inside the flow chamber controlled by the rotation of the basket. The flow resistance of the basket was determined by connecting the pressurized can of Example 1 to the dispensing gun and holding the trigger in the fully open position until no more product was dispensed. The residual pressure inside the can was then measured. The basket of Gun B allows flow from a pressurized can having an internal relative pressure of approximately 50 kPa (0.5 bar) or more at 20°C.

[0078] Gun C: For comparative testing, a pressurized can was also connected to a dispensing gun equipped with a basket having a ball spring check valve and a single spring with a spring constant of 3.72 N / mm. The flow resistance through the basket was determined by connecting the pressurized can of Example 1 to the dispensing gun and keeping the trigger in the fully open position until no more product was dispensed. The residual pressure inside the can was then measured. The basket of Gun C allows flow from a pressurized can with an internal relative pressure of approximately 170 kPa (1.7) bar or more at 20°C.

[0079] The beneficial yield for the user was also tested by determining the number of fillable joints of a given size (joints being fully filled immediately after dispensing, i.e., before any significant post-expansion occurs). Prior to dispensing, the can relative pressures in the formulas in the table below were in the range of 400–600 kPa (4–6) bar at 20°C.

[0080] [Table 1]

[0081] result

[0082] [Table 2]

[0083] As the results show, the assembly of the present invention provides both improved can yield (determined by the amount of residue remaining in the can) and improved joint yield (i.e., the actual value of the product dispensed before post-expansion) compared to using aqueous polymer compositions that do not match the viscosity properties of the present invention or using dispensing guns that do not match the spring constant properties of the present invention.

[0084] The formula for Example 1, dispensed with gun A, is 0.03256 W / m * It was found to have an initial thermal conductivity of K (EN12667) and dimensional stability of -4.5% (EN17333-2(2020)).

[0085] As can be seen from the information provided above, Examples 1-10 all contain approximately 5.6 wt.% of propellant (relative to the combined weight of the foamed aqueous polymer composition and propellant). The inventors also tested the foamed aqueous polymer composition of Example 7 using the same isobutane:propane ratio but with approximately 2 wt.% of propellant (relative to the combined weight of the foamed aqueous polymer composition and propellant). Hardness and dimensional stability (tested according to EN17333-2(2020)) were found to be even more significantly improved compared to Example 7.

Claims

1. An assembly for dispensing polymer foam, A pressurized can containing a foamed aqueous polymer composition and one or more propellants, - A dispensing gun including a basket for fluid connection of the can to the dispensing gun, wherein the basket includes a flow channel for connecting the can to the dispensing gun, and a blocking means configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, The aforementioned foaming aqueous polymer composition is heated to 20°C for 100 seconds. －１ The kinematic viscosity is determined according to a viscosity protocol for shear rates less than 1.5 Pa·s. The aforementioned can has an internal relative pressure of at least 200 kPa at 20°C. The shut-off means contained within the basket is an assembly that allows flow from the pressurized can to an internal relative pressure of less than 120 kPa at 20°C.

2. The shut-off means is a spring-loaded check valve including a spring with a spring constant of less than 1 N / mm, or The assembly according to claim 1, wherein the basket includes an elongated flow channel connecting the can to the dispensing gun, and comprises a blocking means including a pin-like structure placed inside the flow channel, configured to move axially within the flow channel between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun.

3. The assembly according to claim 1 or 2, wherein the foamed aqueous polymer composition comprises 20 to 80 wt.% of the polymer (relative to the total weight of the aqueous polymer composition) and 20 to 70 wt.% of water (relative to the total weight of the aqueous polymer composition).

4. The aforementioned foaming aqueous polymer composition is heated to 20°C for 100 seconds. －１ The assembly according to any one of claims 1 to 3, having a kinematic viscosity determined according to a viscosity protocol at a shear rate of less than 1.2 Pa·s, preferably less than 0.9 Pa·s.

5. The aforementioned foaming aqueous polymer composition is heated to 20°C for 100 seconds. －１ The assembly according to any one of claims 1 to 4, wherein the shear rate is at least 0.5 Pa·s, preferably at least 0.1 Pa·s, and the kinematic viscosity is determined according to a viscosity protocol.

6. The assembly according to any one of claims 1 to 5, wherein the can has an internal relative pressure of at least 300 kPa at 20°C, and preferably an internal relative pressure of less than 1200 kPa at 50°C.

7. The assembly according to any one of claims 1 to 6, wherein the spring-loaded check valve is a ball spring check valve.

8. The assembly according to any one of claims 1 to 7, wherein the foamed aqueous polymer composition is substantially free of reactive isocyanate groups.

9. The assembly according to any one of claims 1 to 8, wherein the foamed aqueous polymer composition comprises less than 5 wt.% (relative to the total weight of the foamed aqueous polymer composition), preferably less than 1 wt.%, and more preferably less than 0.1 wt.% of the monomer.

10. The assembly according to any one of claims 1 to 9, wherein the ratio (w / w) of the foaming aqueous polymer composition to the one or more propellants is in the range of 70:30 to 99.5:0.5, preferably in the range of 80:20 to 99.5:0.5, and more preferably in the range of 90:10 to 99.5:0.

5.

11. The assembly according to any one of claims 1 to 10, wherein the foaming aqueous polymer composition has a minimum film formation temperature of less than 25°C.

12. The assembly according to any one of claims 1 to 11, wherein the foamed aqueous polymer composition comprises a polymer selected from the group consisting of polyurethane, polyacrylate, polyalkyl acrylate, polyurethane acrylate copolymer, polystyrene, styrene acrylate copolymer, polyisocyanurate, polyvinyl acetate, vinyl acetate alkylene copolymer, styrene alkyldiene copolymer, copolymers thereof, and combinations thereof, preferably a polymer selected from the group consisting of polyurethane, polyacrylate, polyurethane acrylate copolymer, copolymers thereof, and combinations thereof.

13. The assembly according to claim 12, wherein the foamed aqueous polymer composition comprises polyurethane or a copolymer thereof.

14. The assembly according to any one of claims 1 to 13, wherein the foaming aqueous polymer composition further comprises one or more additives selected from the group consisting of film-forming agents, dispensing agents, pH adjusters, fillers, flame retardants, surfactants, thickeners, crosslinking agents, and adhesion enhancers.

15. The assembly according to any one of claims 1 to 14, wherein the one or more propellants are selected from the group consisting of dimethyl ether, hydrohaloolefin (preferably HFO1234ze(E)), n-butane, isobutane, propane, and combinations thereof.

16. The assembly according to any one of claims 1 to 15, further comprising: a dispensing tube having a dispensing nozzle; means for opening and closing the dispensing nozzle; and a trigger for operating the means to open the dispensing nozzle and dispense the polymer foam.

17. The assembly according to claim 16, wherein the means for opening and closing the dispensing nozzle includes a spring-loaded needle that can move coaxially within the dispensing tube, and optionally further includes an adjusting means for adjusting the degree of opening of the outlet of the dispensing nozzle.

18. A method for dispensing polymer foam, comprising the following steps: (i) To provide a pressurized can containing a foamed aqueous polymer composition and one or more propellants, wherein the foamed aqueous polymer composition is heated at 20°C for 100 seconds. －１ The can has a kinematic viscosity determined according to a viscosity protocol at a shear rate of less than 1.5 Pa·s, and the can has an internal relative pressure of at least 200 kPa at 20°C. (ii) To provide a dispensing gun including a basket for fluid connection of the can to the dispensing gun, wherein the basket includes a flow channel for connecting the can to the dispensing gun, and a shut-off means configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, wherein the shut-off means contained within the basket allows flow from the pressurized can to an internal relative pressure of less than 120 kPa at 20°C, (iii) By fluid-connecting the can to the dispensing gun, the pressurized can is attached to the dispensing gun, (iv) A method comprising dispensing the polymer composition from the can to obtain the polymer foam.

19. The method according to claim 18, wherein step (iv) is carried out at an ambient temperature of at least 0°C, preferably at least 15°C, and preferably at an ambient relative humidity of less than 80%.

20. The polymer foam obtained in step (iv) has one or more of the following properties, namely, - Post-expansion of at least 15%, preferably at least 25%, as determined according to Method EN17333-2 (2020) - Dimensional change of less than 10%, preferably less than 5%, as determined according to Method EN17333-2 (2020) - A change in tensile strength of less than 10%, preferably less than 5%, after 1000 cycles of 10% compression and elongation according to Method EN17333-4 (2020), and / or - 0.05 W / m as determined in accordance with DIN EN12667:2001 ＊ Less than K, preferably 0.04 W / m ＊ The method according to claim 18 or 19, wherein the polyurethane foam has a thermal conductivity of less than K.

21. A method according to any one of claims 18 to 20 for providing hermetically sealed packaging.

22. The method according to claim 21, wherein the polymer foam is deposited (a) around a door frame such as an interior door frame of a building, or (b) between adjacent parts or layers of a drywall.

23. The method according to any one of claims 18 to 22, wherein less than 15 wt.% of the residue remains in the can after the polymer composition has been dispensed to its maximum extent from the can, and 100 wt.% of the residue corresponds to the total amount of foaming aqueous polymer composition and propellant in the can before any polymer composition has been dispensed from the can.

24. The use of a dispensing gun comprising a basket for fluid connection of a can to the dispensing gun, the basket comprising a flow channel for connecting the can to the dispensing gun, and a shut-off means configured to move between an open position allowing flow from the can to the dispensing gun and a closed position blocking flow from the can through the flow channel to the dispensing gun, wherein in the open position the shut-off means allows flow from the can having an internal relative pressure of less than 120 kPa at 20°C. To dispense polymer foam from a pressurized can containing a foaming aqueous polymer composition and one or more propellants, The aforementioned foaming aqueous polymer composition is heated to 20°C for 100 seconds. －１ The kinematic viscosity according to the viscosity protocol at a shear rate of less than 1.5 Pa·s is The can has an internal relative pressure of at least 200 kPa at 20°C.

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