Sprayable polyurethane foam composition and method for preparing an article coated with said composition
The high open-cell content polyurethane foam composition addresses peeling issues by ensuring strong adhesion and insulation performance through controlled application as a single layer, achieving long-lasting thermal insulation.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- T A S CORP CO LTD
- Filing Date
- 2025-12-26
- Publication Date
- 2026-07-02
Smart Images
Figure IB2025063462_02072026_PF_FP_ABST
Abstract
Description
[0001] SPRAYABLE POLYURETHANE FOAM COMPOSITION AND METHOD FOR PREPARING AN ARTICLE COATED WITH SAID COMPOSITION TECHNICAL FIELD
[0002] Chemistry and materials science related to a sprayable polyurethane foam composition and a method for preparing an article coated with said composition
[0003] BACKGROUND OF THE INVENTION
[0004] Polyurethane foam, commonly referred to as PU foam, is a widely used insulation material due to its outstanding heat and sound blocking properties. It is therefore usually employed in construction by spray-coating surfaces or lining walls, ceilings, roofs, and floors of buildings in order to maintain the temperature inside the building or to reduce energy loss in heating or cooling. In addition, polyurethane foam is commonly used as sound insulation in conference rooms, audio recording rooms, or buildings to help reduce sound transmission. Furthermore, polyurethane foam is used for covering pipes in cooling and heating transport systems, or for covering or coating the surfaces of various equipment that require temperature control. Numerous advantageous properties, such as light weight, low thermal conductivity, resistance to moisture, resistance to chemicals, and ability to be formed into various shapes, make polyurethane foam an important material that is widely used in industrial applications.
[0005] Sprayable polyurethane foam is a type of polyurethane foam that can be directly sprayed at construction sites onto various surfaces or areas. After spraying, the polyurethane foam expands and solidifies to form an insulating layer. Due to to the low thermal conductivity of polyurethane foam, energy loss is effectively reduced. In addition, it provides good resistance to water and moisture and prevents vapor and rainwater leakage. Furthermore, the resulting polyurethane foam is lightweight and therefore does not burden equipment structures or building structures. It also has sufficient flexibility to accommodate temperature changes or building movement. Moreover, polyurethane foam can be installed rapidly and can be sprayed in complex or hard-to-access areas. As a result, it is commonly used in buildings for protection against heat and moisture, for covering pipes in cooling and heating storage systems, and for use in factories to control internal temperature. In particular, sprayable polyurethane foam exhibits good adhesion to a wide variety of materials. With the above-mentioned properties, sprayable polyurethane foam is widely used in construction and industrial applications that require effective insulation.In general, the use of polyurethane thermal insulation foam by coating onto materials is commonly carried out in three forms: producing polyurethane foam insulation as an article by forming it in a mold before attaching it to a material using glue or adhesive, coating polyurethane foam insulation onto an article in a mold, and spraying polyurethane foam insulation onto a material surface. The thickness of polyurethane foam thermal insulation manufactured for sale ranges from 15-200 mm. Polyurethane foam sheets which are articles formed in a mold and adhere to other materials using glue or adhesive have a foam thickness ranging from 15-200 mm. Polyurethane foam insulation coated onto an article in a mold has a foam thickness ranging from 15-75 mm. Polyurethane foam insulation sprayed onto a surface has a foam thickness ranging from 25-50 mm.
[0006] Examples of patent documents related to sprayable polyurethane foam for thermal insulation applications are as follows.
[0007] CN 115073695 B discloses spraying-type environment-friendly polyurethane foam for container modular building heat preservation. The spraying-type polyurethane foam is prepared by spraying a component A and a component B through spraying equipment. The component A comprises a polyol, a surfactant, three types of composite catalysts, water, a physical blowing agent, and a composite flame retardant. The polyol component comprises melamine resin polyol and polyester polyol. The weight ratio of the melamine resin polyol to the polyester polyol is in a range of (30-50): (50-70). The component B is polyphenyl polymethylene polyisocyanate.
[0008] EP 3837296 Bl discloses a process for producing a polyurethane foam by mixing components comprising polymeric MDI (methylene diphenyl diisocyanate) having a content of difunctional MDI of less than 40 wt%, and an aliphatic, halogenated hydrocarbon compound comprising 2 to 5 carbon atoms, at least one hydrogen atom, and at least one fluorine and / or chlorine atom. The aliphatic halogenated hydrocarbon compound contains at least one carbon-carbon double bond mixed in an isocyanate component. The isocyanate component is then reacted with a polyol component to obtain a polyurethane foam. This European patent further discloses a polyurethane foam obtained by said method.
[0009] US 2006084709 Al discloses a rigid sprayable polyurethane foam, which can be prepared using cyclopentane as a blowing agent and which is useful for pipe insulation because of its ability to withstand high temperatures (>250°F or approximately 121°C). The polyurethane foam prepared according to this US patent application is sprayable. The foam is reacted at the ratio of polyol to isocyanate of about 1:1.25.EP 3837296 Bl discloses a formulation and a method for producing polyurethane foam which primarily uses water to create foam. The formulation employs an isocyanate ratio higher than that of conventional foam systems to obtain a water-blown polyurethane foam suitable for applications such as roof spraying and thermal insulation. A formulation suitable for preparing the polyurethane foam comprises an isocyanate component and a polyol component. The polyol component comprises a combination of a Mannich polyol, a polyester polyol, and a polyether polyol. In addition, water is also present as a blowing agent, and a metal salt catalyst is added to facilitate the reaction, with a suitable isocyanate index in the range of approximately 1.2 to 2.0.
[0010] Although sprayable polyurethane foam has outstanding thermal insulation properties, peeling issues may occur in certain cases from various causes, such as improper surface preparation or moisture or residual contaminants on the surface, which result in poor adhesion of the foam to the surface. In addition, if the polyurethane foam composition, the mixing process, or the foam spraying conditions are inappropriate, the foam may expand abnormally and does not adhere firmly to the surface, leading to low-quality foam and subsequent peeling.
[0011] SUMMARY OF THE INVENTION
[0012] In order to address the limitations of sprayable polyurethane foam mentioned above, the present invention focuses on the development of a polyurethane spray foam composition having improved properties, so as to enable effective use and a longer service life.
[0013] In particular, the invention is intended to develop a sprayable polyurethane foam composition for thermal insulation, emphasizing on coating the sprayable polyurethane foam composition developed according to the invention onto surfaces of various materials to obtain an article coated with a polyurethane foam composition suitable for thermal insulation applications and exhibiting good performance even when applied at a relatively thin coating thickness, for example in a range of 2-15 mm, which is substantially thinner than conventional coating products generally available on the market.
[0014] In addition, the invention is further intended to develop a method for preparing a coated article by spraying the polyurethane foam composition developed according to the present invention onto a surface of an article. The polyurethane foam coating layer is thin and capable of adhering to all types of article surfaces and to a variety of materials, thereby enabling a wide range of applications and allowing coating of any desired product. The polyurethane foam-coated thermal insulating layer is a single layer and has a uniform thickness, so as to be suitablefor use and capable of maintaining its condition without peeling, thereby reducing the problems and limitations of the prior arts.
[0015] In the first aspect, the present invention discloses a sprayable polyurethane foam composition comprising:
[0016] a polyol component comprising a polyol, a catalyst, a flame retardant, a blowing agent, a surfactant, and a cross-linking agent; and
[0017] an isocyanate component.
[0018] According to a preferred embodiment, the sprayable polyurethane foam composition is an open-cell foam having an open-cell content of at least 75%. Preferably, the open-cell content is at least 95%.
[0019] The sprayable polyurethane foam composition according to the present invention has high open-cell content, which is advantageous in terms of delamination between the material and the sprayable polyurethane foam composition coated on the surface of the article. That is, it helps reduce peeling of the foam layer from the coated surface when the article is in use and heat is generated due to environmental conditions. The physical characteristics of open-cell polyurethane foam allows heat transfer, thereby preventing delamination between the surface of the article and the polyurethane foam composition.
[0020] In the second aspect, the present invention discloses a method for preparing a coated article comprising a step of coating a surface of an article by spraying the sprayable polyurethane foam composition according to the invention onto the surface of the article to cause a foaming reaction and a polymerization reaction.
[0021] Preferably, the foaming reaction has a cream time ranging from 3-6 seconds and the polymerization reaction has a reaction time ranging from 7-25 seconds.
[0022] The sprayable polyurethane foam composition according to the present invention is particularly suitable for use as a composition for coating various material surfaces and provides several advantages. That is, the composition is environmentally friendly, has non-complex components, can be easily prepared, and has simple preparation steps. When an article coated with the polyurethane foam composition is prepared using the aforementioned method, the polyurethane foam composition can be applied at a thickness ranging from 2-15 mm to provide desired properties. That is, the thermal insulation properties remain at the desired level even at a thickness of only 2-15 mm, while the coated article also maintains strength, impact resistance, water resistance, and peeling resistance in actual use. Moreover, coating to achieve the desiredthickness can be carried out in a single layer, which makes peeling more difficult to occur compared with other foams that require multilayer coating.
[0023] BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Fig. 1 shows the cell structure characteristics of the polyurethane foam prepared according to the present invention using a scanning electron microscope. The polyurethane foam sample was cut and its cross-sectional area was examined at a magnification of 250 pm at the surface region (Fig. 1(a)), the side region (Fig. 1(b)), and the bottom region (Fig. 1(c)) of the polyurethane foam.
[0025] Fig. 2 shows the article with the surface coated with the polyurethane foam prepared according to the present invention. The polyurethane foam was coated onto smooth-surface materials having dimensions of 1.2 m x 1.0 m at thicknesses of 3 mm (Fig. 2(a)), 5 mm (Fig.
[0026] 2(b)), 10 mm (Fig. 2(c)), and 15 mm (Fig. 2(d)).
[0027] Fig. 3 shows the relationship between the temperatures beneath the roofs (°C) at different times by comparing a roof without a thermal insulation coating, a roof coated with the polyurethane foam thermal insulation according to the present invention at a thickness of 5 mm, and a roof coated with the polyurethane foam thermal insulation according to the present invention at a thickness of 10 mm.
[0028] DETAILED DESCRIPTION
[0029] Any aspects disclosed herein shall encompass application to other aspects according to the present invention, unless specified otherwise.
[0030] Throughout the present invention, the terms “consist(s) of,” “contain(s),” “comprise(s),” “has / have,” and “include(s)” are open-ended verbs. For example, any method that “consist(s) of,” “contain(s),” “comprise(s),” “has / have,” or “include(s)” one or more components or one or more steps is not limited to only the one or more components or steps, but also encompasses additional components or steps that are not specified.
[0031] The term “about” as used herein indicates that any presented or illustrated value or quantity may vary or deviate. Such variation or deviation may arise from errors of the equipment or methods used to determine such value or quantity.
[0032] Any tools, equipment, methods, materials, or chemicals mentioned herein, unless specified, otherwise, refer to tools, equipment, methods, materials, or chemicals commonly used or practiced by persons skilled in the art.Numerical ranges used herein are understood to include possible sub-ranges and all individual numbers or values within those ranges (including fractions and integers).
[0033] Values used herein include all values that would be the same as such values after rounding.
[0034] All components and / or methods disclosed and claimed in the present invention are intended to encompass aspects of the invention obtained by actions, practices, modifications, or changes to any factors that do not require experimentation substantially different from the present invention, and that provide properties, utility, and effects similar to those of the aspects of the present invention in the view of a person of ordinary skill in the art, although not specifically stated in the claims. Accordingly, substitutions or analogues of the aspects of the present invention, including any minor modifications or changes that are apparent to a person of ordinary skill in the art, should be considered to fall within the spirit, scope, and concept according to the present invention.
[0035] Technical and scientific terms used herein have the meanings as understood by a person of ordinary skill in the art, unless defined otherwise.
[0036] The present invention provides the sprayable polyurethane foam composition and the method for preparing an article coated with said sprayable polyurethane foam composition. Such article can be made of different materials and can be used in various applications.
[0037] Materials used for preparing the article according to the present invention can be any material without limiting the scope of the present invention. Examples of materials of the article that can be used in the present invention may be selected from the group consisting of steel, cold-rolled steel, galvanized sheet, gypsum, tile, terracotta tile, fiberglass, wood, plywood, polymer, acrylic, plastic, unplasticized polyvinyl chloride, polyvinyl chloride (PVC), cement, concrete, glass, composite material, and a mixture thereof.
[0038] In the first aspect, the sprayable polyurethane foam composition according to the present invention comprises:
[0039] a polyol component comprising a polyol, a catalyst, a flame retardant, a blowing agent, a surfactant, and a cross-linking agent, and
[0040] an isocyanate component.
[0041] According to a preferred embodiment, the sprayable polyurethane foam composition is an open-cell foam having an open-cell content of at least 75%. Preferably, the open-cell content is at least 95%.In general, polyurethane foams used in thermal insulation applications to prevent the transfer of thermal energy from one side to the other usually have a closed-cell structure because of its low thermal conductivity coefficient (K-value) and high thermal resistance (R-value).
[0042] However, the inventors of the present invention have found that the sprayable polyurethane foam according to the present invention, which has the open-cell foam structure, provides the desired low thermal conductivity and high thermal resistance with sufficient efficiency, and is suitable for use as thermal insulation. In addition, the polyurethane foam composition according to the present invention having the open-cell content within the specified range can be advantageous in terms of delamination between the material and the polyurethane foam coated on the surface. That is, peeling of the foam layer from the coated surface is difficult to occur, because the physical characteristics of the open-cell polyurethane foam facilitate heat transfer during use, thereby preventing delamination between the material surface and the polyurethane foam layer, or causing peeling to occur more slowly than conventional foams that cannot transfer heat.
[0043] In an embodiment, the polyol component may further comprise a cell-opening agent, an additive, or a mixture thereof.
[0044] In a preferred embodiment, polyol is selected from the group consisting of polyether polyol, polyester polyol, and a mixture thereof.
[0045] As an example, polyether polyol is sorbitol-based polyether polyol, polypropylene glycol, or a mixture thereof.
[0046] In a more specific embodiment, polyether polyol in the polyol component according to the present invention has a hydroxyl value ranging from 350-450 mg KOH / g and a viscosity ranging from 120-320 cPs, as measured at a temperature of 25°C. Preferably, the polyol component comprises polyether polyol in an amount ranging from 15-75 wt%.
[0047] As an example, the catalyst may be selected from the group consisting of amine catalyst, organometallic catalyst, and a mixture thereof. The catalyst may be present as a single catalyst or a combination of catalysts. Preferably, the polyol component comprises the catalyst in an amount ranging from 0.5-3.5 wt%.
[0048] As an example, the flame retardant is chlorinated organophosphate compound. Preferably, the polyol component comprises the flame retardant in an amount ranging from 10-35 wt%.As an example, the blowing agent is selected from the group consisting of water, hydrocarbon compound, halogenated hydrocarbon compound, and a mixture thereof. Preferably, the polyol component comprises the blowing agent in an amount ranging from 3-25 wt%.
[0049] In an exemplary embodiment, the sprayable polyurethane foam composition according to the present invention contains the polyol component comprising:
[0050] a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 15-70 wt%,
[0051] an amine catalyst in an amount ranging from 0.5-3.5 wt%,
[0052] a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%,
[0053] a blowing agent which is water in an amount ranging from 3-5 wt%,
[0054] a surfactant in an amount ranging from 1-3 wt%, and
[0055] a cross-linking agent in an amount ranging from 2-5 wt%.
[0056] In another exemplary embodiment, the sprayable polyurethane foam composition according to the present invention contains the polyol component comprising:
[0057] a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 25-75 wt%,
[0058] an amine catalyst and an organometallic catalyst in an amount ranging from 0.5-3.5 wt%,
[0059] a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%,
[0060] a blowing agent which is a mixture of halogenated hydrocarbon compound and water in an amount ranging from 3-15 wt%,
[0061] a surfactant in an amount ranging from 1-3 wt%,
[0062] a cross-linking agent in an amount ranging from 2-5 wt%, and
[0063] a cell-opening agent in an amount ranging from 0.1-2.5 wt%.
[0064] Adjusting the proportions of the aforementioned chemical substances results in a polyol component that is suitable for use as a component in the polyurethane foam composition. The polyol component according to the present invention has a hydroxyl value ranging from 350-450 mg KOH / g and a viscosity ranging from 120-320 cPs, as measured at a temperature of 25°C.In a preferred embodiment, the polyurethane foam composition comprises the isocyanate component, which is selected from the group consisting of aliphatic isocyanate, cycloaliphatic isocyanate, aromatic polyisocyanate, methylene diphenyl diisocyanate, and a mixture thereof. Preferably, the isocyanate component is present in an amount ranging from 60-100 wt%.
[0065] As an example, the isocyanate component has an isocyanate index ranging from 100-130, preferably 110-115, and a viscosity ranging from 150-230 cPs, as measured at a temperature of 25°C.
[0066] Preferably, the ratio of the polyol component to the isocyanate component is in a range of 1 to 0.8-1.2. More preferably, the ratio of the polyol component to the isocyanate component is about 1 to 1.
[0067] In a preferred embodiment, the sprayable polyurethane foam composition according to the present invention is used for coating a surface of an article used in thermal insulation applications. The method for preparing the coated article comprises a step of coating the surface of the article by spraying the polyurethane composition according to the invention onto the surface of the article in order to form a foam having a thickness uniformity in the range of 2-15 mm as a single layer that is uniform across the entire sheet and having shape conformity to the coated surface.
[0068] The second aspect of the invention relates to a method for preparing an article coated with the sprayable polyurethane foam composition according to the present invention. The method is carried out by spraying the polyurethane foam composition onto the surface of the article to cause a foaming reaction with a cream time ranging from 3-6 seconds and a polymerization reaction with a reaction time ranging from 7-25 seconds. The polymerization reaction occurring on the surface of the material enables the polyurethane foam to adhere to the surface of the material, thereby offering durability and reducing peeling of the polyurethane foam layer without the need to apply an adhesive or a bonding agent between the foam layer and the material surface.
[0069] Preferably, the surface coating of the article is carried out with the thickness of the polyurethane spray foam composition ranging from 2-15 mm and at a temperature ranging from 20-45°C.
[0070] Preferably, the surface coating of the article is carried out with a viscosity of the polyol component and a viscosity of the isocyanate component ranging from 60-360 cPs. Morepreferably, the surface coating is carried out such that the viscosity of the polyol component and the viscosity of the isocyanate component differ by no more than 10%.
[0071] The article according to the present invention can be made of any material and can have various shapes without limitation. As an example, the article may be made of a material selected from the group consisting of steel, cold-rolled steel, galvanized sheet, gypsum, tile, terracotta tile, fiberglass, wood, plywood, polymer, acrylic, plastic, unplasticized polyvinyl chloride, polyvinyl chloride (PVC), cement, concrete, glass, composite material, and a mixture thereof.
[0072] The article having a surface coated with the polyurethane foam composition prepared by the method according to the present invention can be applied in a wide variety of applications, and is particularly suitable for use as a thermal insulation article, such as roofs, ceilings, walls, floors, and pipes.
[0073] According to a preferred embodiment of the present invention, the sprayable polyurethane foam composition having the open-cell content of at least 75%, preferably at least 95%, can be provided. The composition can be used for preparing an article by spraying on the surface of various materials and can be applied at a thickness ranging from 2-15 mm in a controlled manner while still maintaining the desired strength and insulation properties, for example. When using the obtained article, it was found that there was no peeling of the polyurethane foam layer for at least 120 days.
[0074] The invention will now be described in more detail with reference to examples and experiments described below. The examples and experimental results described herein are merely examples of the invention and are not intended to specify any aspects of the invention in any way.
[0075] According to the present invention, the term “polyurethane molten” refers to a mixture of the polyol component and the isocyanate component and may further comprise other related components or chemical substances, while such mixture remains in liquid state.
[0076] According to the present invention, the term “polyurethane thermal insulation” refers to solid polyurethane formed by a reaction between the polyol component and the isocyanate component and may further comprise other related components or chemical substances.
[0077] According to the present invention, the term “cream time” refers to the time at which the mixture of the polyol component and the isocyanate component, and possibly other related components or chemical substances, begins to change its state from a polyurethane molten to a cream.According to the present invention, the terms “polymerization reaction time” or “reaction time” refer to the time at which the polymerization reaction begins while the polyurethane foam is expanding.
[0078] According to the present invention, the term “polyurethane foam” refers to polyurethane in a state from the initiation of the polymerization reaction until the expansion stops and the polyurethane solidifies.
[0079] According to the present invention, the term “single linear planar dispersion” refers to the dispersion of the polyurethane molten in only one linear planar direction.
[0080] According to the present invention, the team “thickness uniformity” refers to a uniform thickness of the polyurethane foam coating, with an average deviation of approximately 2 mm.
[0081] According to the present invention, the team “shape conformity” refers to polyurethane that is dispersed and formed such that it adheres to one side of the material and the polyurethane foam coated on the surface of such material has a shape conforming to the surface of the material.
[0082] Experiment
[0083] 1) Sprayable polyurethane foam composition
[0084] According to the present invention, the sprayable polyurethane foam composition comprises at least two components: polyol component and isocyanate component.
[0085] In an embodiment, the sprayable polyurethane foam composition contains the polyol component comprising:
[0086] a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 15-70 wt%,
[0087] an amine catalyst in an amount ranging from 0.5-3.5 wt%,
[0088] a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%
[0089] a blowing agent which is water in an amount ranging from 3-5 wt%,
[0090] a surfactant in an amount ranging from 1-3 wt%, and
[0091] a cross-linking agent in an amount ranging from 2-5 wt%.
[0092] In another embodiment, the sprayable polyurethane foam composition according to the present invention contains the polyol component comprising:
[0093] a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 25-75 wt%,an amine catalyst and an organometallic catalyst in an amount ranging from 0.5-3.5 wt%,
[0094] a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%,
[0095] a blowing agent which is a mixture of halogenated hydrocarbon compound and water in an amount ranging from 3-15 wt%,
[0096] a surfactant in an amount ranging from 1-3 wt%,
[0097] a cross-linking agent in an amount ranging from 2-5 wt%, and
[0098] a cell-opening agent in an amount ranging from 0.1-2.5 wt%.
[0099] The polyol component used according to the present invention has a hydroxyl value ranging from 350-450 mg KOH / g and a viscosity ranging from 120-320 cPs, as measured at a temperature of 25°C.
[0100] The isocyanate component is selected from the group consisting of aliphatic isocyanate, cycloaliphatic isocyanate, aromatic polyisocyanate, methylene diphenyl diisocyanate, and a mixture thereof. Preferably, the isocyanate component is present in an amount ranging from 60-100 wt% and has an isocyanate index ranging from 100-130, preferably 110-115, and a viscosity ranging from 150-230 cPs, as measured at a temperature of 25°C.
[0101] The ratio of the polyol component to the isocyanate component ranges from 1 to 0.8-1.2, preferably about 1 to 1. Additional components may be added to the mixture of the polyol component and the isocyanate component before spraying.
[0102] 2) Method for preparing an article coated with sprayable polyurethane foam composition The method for preparing an article coated with the sprayable polyurethane foam composition according to the present invention was carried out by coating the article by spraying the polyurethane foam composition into the surface of the article such that the dispersion direction of the polyurethane molten was in a single linear planar direction without the use of formwork or mold. The method was carried out at a temperature ranging from 20-45°C and at the viscosities of the polyol component and the isocyanate component ranging from 60-360 cPs. The foaming reaction occurred with a cream time ranging from 3-6 seconds and the polymerization reaction occurred over a period ranging from 7-25 seconds. The polymerization reaction taking place on the material surface allowed the polyurethane foam to adhere to said material surface. The article is thus durable, and the peeling of the polyurethane foam layer is reduced without the need to apply an adhesive or a bonding agent between the foam layer andthe material surface. The polyurethane foam formed of the polyurethane molten is dispersed as a single layer, has a thickness uniformity across the entire sheet, and has a shape conforming to the surface of the material. The method according to the present invention was carried out with the thickness of the polyurethane foam composition ranging from 2-15 mm. Preferably, the method according to the present invention was carried out at a temperature ranging from 20-45°C and the viscosities of the polyol component and the isocyanate component ranging from 60-360 cPs. The percentage difference in viscosity is less than 10%, as shown in Table 1.
[0103] Table 1 shows the relationship between the viscosities of the chemical substances at different operating temperatures.
[0104] Operating temperature Viscosity (cPs) % difference in (°C) Polyol component Isocyanate component viscosity 20 356 355 0.28 25 226 236 -4.42 30 175 160 8.57 35 129 120 6.98 40 95 94 1.05
[0105]
[0106] 45 84 70 16.67 The testing shows that the viscosities of the polyol component and the isocyanate component are significantly lower at higher operating temperatures. It was found that the suitable operating temperature (with the % difference in viscosity less than 10%) ranges from 20-40°C.
[0107] Examples of materials suitable for the preparation of the article, on which the polyurethane spray foam composition can be coated on the surface and can adhere as a thin layer with a single-layer dispersion are steel, cold-rolled steel, galvanized sheet, gypsum, tile, terracotta tile, fiberglass, wood, plywood, polymer, acrylic, plastic, unplasticized polyvinyl chloride, polyvinyl chloride (PVC), cement, concrete, glass, composite materials, and mixtures thereof.
[0108] 3) Analysis of sprayable polyurethane foam composition properties
[0109] The properties of the spray able polyurethane foam composition coated on surface of any materials according to the present invention were analyzed using the method and technique as detailed hereinafter.3.1 Physical characteristics
[0110] The internal characteristics or cell structure of the polyurethane foam can be examined using a scanning electron microscope. The polyurethane foam sample according to the present invention was cut and its cross-sectional area was examined at a magnification of 250 pm, which shows that the prepared polyurethane foam is an open-cell foam. It was further found that, when the open-cell content was tested using the ISO 4590 test method, the polyurethane spray foam composition according to the present invention had an open-cell content of at least 75%, preferably at least 95%. An example of the cell structure of the polyurethane foam is shown in Fig. 1.
[0111] With respect to appearance, the polyurethane foam according to the present invention had a smooth, glossy surface and was coated on the surface of the material as a thin layer. The polyurethane foam was dispersed as a single layer and had a thickness ranging from 2-15 mm, preferably 2-13 mm, more preferably 3-7 mm. The polyurethane foam coated on the surface of the material according to the present invention had a uniform thickness across the entire sheet, with an average thickness deviation of 2 mm. The articles obtained were coated with the polyurethane foam composition according to the present invention at thicknesses of 3 mm, 5 mm, 10 mm, and 15 mm, as shown in Fig. 2.
[0112] In addition, adjusting the proportions of the chemical substances in the polyol component increased the open-cell content of the polyurethane foam. Different cell-opening agents well known to those skilled in the art of polymer may be added to help increase the open-cell content of the polyurethane composition.
[0113] Table 2 shows the change in the open-cell content upon the addition of LB catalyst, which is a commercially available metal carboxylate catalyst, as a cell -opening agent.
[0114] Table 2
[0115] Sample LB catalyst content (wt%) Close-cell content (%) Open-cell content (%) 1 - 90.6 9.4
[0116] 2 0.1 70.1 29.9
[0117] 3 0.2 24.9 75.1
[0118] 4 0.3 19.8 80.2
[0119] 5 0.5 4.2 95.8
[0120] 6 0.8 3.9 96.1
[0121]
[0122] 7 1.0 3.7 96.3From the results of testing the open-cell content of the polyurethane foam using the ISO 4590 method, it was found that the addition of the LB catalyst increased the open-cell content of the resulting polyurethane foam. The addition of only 0.2 wt% of the LB catalyst allowed the polyurethane foam to achieve an open-cell content of 75%, and an open-cell content as high as 96.3% was obtained when 1.0 wt% of the LB catalyst was added. However, it was observed that polyurethane foam formed with the addition of 1.0 wt% of the LB catalyst exhibited a rough foam surface and foam collapse. In addition, adding the LB catalyst in an amount greater than 0.8 wt% did not result in a significant difference in the open-cell content of the polyurethane foam. Accordingly, the suitable amount of the LB catalyst ranges from 0.2 to 0.8 wt%.
[0123] 3.2 Density, compressive strength, and surface tension
[0124] The polyurethane foam sample was cut to a size of 50 x 50 x 30 mm. The density and compressive strength of the foam sample were measured. The polyurethane foam according to the present invention had a core density ranging from 25-38 kg / m3, an overall density ranging from 40-80 kg / m3, a compressive strength ranging from 80-160 kPa, and a surface tension ranging from 30-54 dyne / cm.
[0125] 3.3 Thermal conductivity
[0126] The examination of the polyurethane foam thermal conductivity can be carried out using a heat flow meter at a temperature of 24°C. It was found that the polyurethane foam according to the present invention had a thermal conductivity coefficient in the range of 0.022-0.035 W / m K at 24°C.
[0127] 4) Adhesion properties and performance of sprayable polyurethane foam composition The adhesion capability of the polyurethane foam on various material surfaces was determined by the chemical process between two chemical substances: the polyol component and the isocyanate component. The mixing ratio of the two components according to the present invention ranges from 0.8-1.2 to 0.8-1.2, preferably approximately 1.0 to 1.0.
[0128] The adhesion step on the material surface occurred after the two chemical substances were mixed to form a polyurethane molten within a time period between the cream time (3-6 seconds) and the polymerization reaction time (7-25 seconds).
[0129] In thermal insulation applications, a common problem is peeling after a period of use, particularly for insulations adhered to materials using adhesives. In addition, there is also a problem with polyurethane insulations with low adhesion when the molding process time doesnot correspond with the cream time to the polymerization reaction time, or when the mold temperature or viscosity is inappropriate.
[0130] 5) Polyurethane foam peelins test using burn test and baking test
[0131] As a comparative example, a test was conducted by heating the surface of a metal sheet coated with a closed-cell polyurethane foam composition using a bum test method. It was found that the foam expanded and detached from the surface of the metal sheet when the temperature of the top surface of the foam reached 43°C during a heating period of 15 seconds. Another test was conducted by heating the surface of a metal sheet coated with the closed-cell polyurethane foam composition using a baking test method. The metal sheet was heated in an oven at 100°C for 3.30 minutes. The foam expanded and detached from the surface of the metal sheet during a baking period of 2.26 minutes.
[0132] 5.1 Peeling test of sprayable polyurethane foam composition containing LB catalyst When the LB catalyst was added in an amount starting from 0.2 wt% based on the polyol component and a peeling testing was conducted using the bum test method, it was found that the time required to cause peeling of the foam from the surface of the metal sheet was prolonged, and no peeling was found when the LB catalyst was added in an amount starting from 0.5 wt% based on the polyol component. Further, when a test was conducted using the baking method at a temperature ranging from 80-100°C, it was found that the addition of the LB catalyst in an amount starting from 0.2 wt% based on the polyol component resulted in no peeling of the foam from the surface of the metal sheet when baked at 80°C for 3 minutes. The results of the content of a single catalyst added which affects the peeling of the obtained foam from the surface of the material are shown in Table 3.
[0133] Table 3
[0134] Sample LB catalyst content Open-cell Peeling results
[0135] (wt%) content (%) bum test baking test 1 - 9.4 Peeling occurred Peeling occurred 2 0.1 29.9 Peeling occurred Peeling occurred 3 0.2 75.1 Peeling occurred No peeling 4 0.3 80.2 Peeling occurred No peeling 5 0.5 95.8 No peeling No peeling
[0136]
[0137] 6 0.8 96.1 No peeling No peelingThe test results show that the polyurethane foam composition according to the present invention, which is an open-cell foam having an open-cell content of at least 75%, particularly at least 95%, can solve the problem of peeling between the material surface and the coating polyurethane foam. When the cell structure of the polyurethane foam is a closed-cell structure, heat applied to the article is transferred to the air-filled cell cavities of the foam. As a result, heat accumulation occurs, as the heat cannot be transferred to the outer cells. In other words, heat transfer from the cells is low. As heat accumulation within the cells increases, the air cavities in the lower region adjacent to the material surface expand, causing the cell walls to expand and the foam to become deformed. The adhesion force between the polyurethane foam and the material surface thus becomes lower, ultimately resulting in peeling from the material.
[0138] The article prepared according to the present invention containing the LB catalyst in an amount of 0.5 wt% was installed under simulated actual-use conditions for 120 days. The condition of the article and the surface adhesion after installation were subsequently inspected. The polyurethane foam composition according to the present invention coated on the material surface was installed under simulated actual-use conditions at a temperature ranging from 7-43°C and a humidity ranging from 40-96% for 120 days and for more than 2 years. Peeling due to physical changes in the polyurethane foam was observed, such as changes in foam dimensions including width, length, and thickness, collapse, and deformation. It was found that the article having the polyurethane foam composition according to the present invention coated on the surface did not exhibit peeling of the polyurethane foam. The article has peeling resistance equivalent to a service life of more than 60 months.
[0139] 5.2 Peeling test of polyurethane foam composition containing water as the sole blowing
[0140] When the peeling test was conducted using the burn test method, it was found that the time required for the foam to peel off from the metal sheet surface increased as the open-cell content of the polyurethane foam composition increased. When the peeling test was conducted using the baking method at a temperature ranging from 80-100°C, no peeling was found when the polyurethane foam composition had an open-cell content of at least 95%. There was no peeling of the foam from the metal sheet surface after baking at 80°C for 3 minutes. The results of the open-cell content which affects the peeling of the obtained foam from the material surface are shown in Table 4.Table 4
[0141] Test sample Open-cell content Peeling results
[0142] (%) bum test baking test 1 95.55 Peeling occurred at 18 seconds No peeling 2 97.54 Peeling occurred at 26 seconds No peeling
[0143]
[0144] 3 98.12 Peeling occurred at 35 seconds No peeling When adhesion and physical change were tested in accordance with ISO 2796, it was found that the polyurethane foam composition according to the present invention having the open-cell content of at least 97% exhibited no peeling.
[0145] The article prepared from the polyurethane foam composition containing water as a sole blowing agent was installed under simulated actual -use conditions for 120 days. The condition of the article and the surface adhesion after installation were subsequently inspected. The polyurethane foam composition according to the present invention coated on the material surface was installed under simulated actual-use conditions at a temperature ranging from 7-43°C and a humidity ranging from 40-96% for 120 days and for more than 2 years. Peeling due to physical changes of the polyurethane foam was observed, such as change in foam dimensions including width, length, and thickness, collapse, and deformation. It was found that the article having the polyurethane foam composition according to the present invention coated on the surface did not exhibit peeling of the polyurethane foam. The article has peeling resistance equivalent to a service life of more than 60 months.
[0146] In addition to the peeling tests, a test for determining the heat-reduction efficiency of the polyurethane foam thermal insulation according to the present invention was also conducted by measuring the temperatures beneath the roofs at different times and comparing a roof without thermal insulation to a roof coated with the polyurethane foam thermal insulation according to the present invention at a thickness of 5 mm and a roof coated with the polyurethane foam thermal insulation according to the present invention at a thickness of 10 mm. The test results are shown in Fig. 3. It was found that the metal sheet roof coated with polyurethane insulation applied by a thin, continuous spray method at a thickness of 5 mm reduced the temperature beneath the roof by up to 7.5°C compared with the roof without thermal insulation. The metal sheet roof coated with polyurethane insulation applied by a thin, continuous spray method at a thickness of 10 mm reduced the temperature beneath the roof by up to 17.7°C compared with the roof without thermal insulation. Upon observation of the temperature beneath the roof during the day, it was found that the temperature beneath the roof coated with thermal insulation havinga thickness of 10 mm was lower than the temperature beneath the roof coated with thermal insulation having a thickness of 5 mm. However, upon observation of the temperature beneath the roof during the evening, during which the insulation begins to release heat, it was found that the roof coated with thermal insulation having a thickness of 5 mm released heat more rapidly than the roof coated with thermal insulation having a thickness of 10 mm. As a result, the evening temperature beneath the roof coated with thermal insulation having a thickness of 5 mm was lower than the temperature beneath the roof coated with thermal insulation having a thickness of 10 mm.
[0147] In general, the compositions used as thermal insulation are typically applied at a thickness of at least 1-2 inches in order to prevent heat transfer from one side to the other. However, a problem of thick insulation is that heat retained during periods of high temperature is transferred less efficiently when the surrounding temperature decreases. In other words, the rate of heat transfer is slow. Accordingly, a roof coated with the thermal insulation according to the present invention addresses these problems by adopting a thickness in the range of 2-15 mm, which still provides sufficient insulation properties. When the ambient temperature decreases, heat stored within the insulation is transferred more efficiently, resulting in a faster rate of heat release. Moreover, due to the thin thickness, the insulation is lightweight and does not burden the structure. The composition can also be sprayed following the shape of the material surface.
[0148] It can be seen that when the polyurethane foam composition is coated onto various material surfaces, the polyurethane foam composition exhibits good surface-coating capability. The polyurethane foam composition can adhere to the article material as a thin, single layer, which is different from the prior arts that require multiple spray applications to achieve the desired thickness, resulting in multilayer coatings and causing peeling to occur more easily. In addition, when comparing surface textures, thermal insulation with multilayer coatings usually has a rough surface, whereas the thermal insulation according to the present invention has a smooth surface, which prevents water or moisture from entering the structure beneath the insulation more effectively.
[0149] The article coated with the polyurethane foam composition prepared according to the present invention can be applied in a wide variety of applications, such as thermally insulated roofs, thermally insulated ceilings, thermally insulated walls, thermally insulated floors, and thermally insulated pipes.BEST MODE OF THE INVENTION
[0150] Best mode of the invention is as described in the detailed description of the invention.
Claims
1. WHAT IS CLAIMED IS:
1. A sprayable polyurethane foam composition comprising:a polyol component comprising a polyol, a catalyst, a flame retardant, a blowing agent, a surfactant, and a cross-linking agent; andan isocyanate componentwherein the sprayable polyurethane foam composition is an open-cell foam having an open-cell content of at least 75%.
2. The sprayable polyurethane foam composition according to claim 1, which is an open-cell foam having the open-cell content of at least 95%.
3. The sprayable polyurethane foam composition according to claim 1, wherein the polyol component further comprises a cell-opening agent, an additive, or a mixture thereof.
4. The sprayable polyurethane foam composition according to claim 1, wherein polyol is selected from the group consisting of polyether polyol, polyester polyol, and a mixture thereof.
5. The sprayable polyurethane foam composition according to claim 4, wherein poly ether polyol is sorbitol-based polyether polyol, polypropylene glycol, or a mixture thereof.
6. The sprayable polyurethane foam composition according to claim 4 or 5, wherein poly ether polyol has a hydroxyl value ranging from 350-450 mg KOH / g and a viscosity ranging from 120-320 cPs, as measured at a temperature of 25°C.
7. The sprayable polyurethane foam composition according to claim 4 or 5, wherein the polyol component comprises polyether polyol in an amount ranging from 15-75 wt%.
8. The sprayable polyurethane foam composition according to claim 1, wherein the catalyst is selected from the group consisting of amine catalyst, organometallic catalyst, and a mixture thereof, and the polyol component comprises the catalyst in an amount ranging from 0.5-3.5 wt%.
9. The sprayable polyurethane foam composition according to claim 1, wherein the flame retardant is chlorinated organophosphate compound, and the polyol component comprises the flame retardant in an amount ranging from 10-35 wt%.
10. The sprayable polyurethane foam composition according to claim 1, wherein the blowing agent is selected from the group consisting of water, hydrocarbon compound, halogenated hydrocarbon compound, and a mixture thereof, and the polyol component comprises the blowing agent in an amount ranging from 3-25 wt%.
11. The sprayable polyurethane foam composition according to claim 1, wherein the polyol component comprises:a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 15-70 wt%,an amine catalyst in an amount ranging from 0.5-3.5 wt%,a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%,a blowing agent which is water in an amount ranging from 3-5 wt%, a surfactant in an amount ranging from 1-3 wt%, anda cross-linking agent in an amount ranging from 2-5 wt%.
12. The sprayable polyurethane foam composition according to claim 1, wherein the polyol component comprises:a polyol comprising a mixture of sorbitol-based polyether polyol and polypropylene glycol in an amount ranging from 25-75 wt%,an amine catalyst and an organometallic catalyst in an amount ranging from 0.5-3.5 wt%,a chlorinated organophosphate flame retardant in an amount ranging from 10-35 wt%,a blowing agent which is a mixture of halogenated hydrocarbon compound and water in an amount ranging from 3-15 wt%,a surfactant in an amount ranging from 1-3 wt%,a cross-linking agent in an amount ranging from 2-5 wt%, anda cell-opening agent in an amount ranging from 0.1-2.5 wt%.
13. The sprayable polyurethane foam composition according to claim 1, wherein the isocyanate component is selected from the group consisting of aliphatic isocyanate, cycloaliphatic isocyanate, aromatic polyisocyanate, methylene diphenyl diisocyanate, and a mixture thereof.
14. The sprayable polyurethane foam composition according to claim 13, wherein the isocyanate component comprises methylene diphenyl diisocyanate in an amount ranging from 60-100 wt%.
15. The sprayable polyurethane foam composition according to claim 1 or 13, wherein the isocyanate component has an isocyanate index ranging from 100-130 and a viscosity ranging from 150-230 cPs, as measured at a temperature of 25°C.
16. The sprayable polyurethane foam composition according to claim 1, wherein the ratio of the polyol component to the isocyanate component ranges from 1 to 0.8- 1.2.
17. The sprayable polyurethane foam composition according to any one of claims 1-16, which is used for coating a thermal insulation article by forming a foam having a thickness ranging from 2-15 mm.
18. The sprayable polyurethane foam composition according to any one of claims 1-16, which is used for coating the surface of a thermal insulation article by forming a single-layer foam with thickness uniformity.
19. A method for preparing a coated article comprising a step of coating a surface of an article by spraying the sprayable polyurethane foam composition according to any one of claims 1-18 onto the surface of the article to cause a foaming reaction with a cream time ranging from 3-6 seconds and a polymerization reaction with a reaction time ranging from 7-25 seconds.
20. The method for preparing a coated article according to claim 19, wherein the coating of the article surface is carried out at a thickness of the sprayable polyurethane foam composition ranging from 2-15 mm.
21. The method for preparing a coated article according to claim 19, wherein the coating of the article surface is carried out at a temperature ranging from 20-45°C.
22. The method for preparing a coated article according to claim 19, wherein the coating of the article surface is carried out at the viscosity of the polyol component and a viscosity of the isocyanate component ranging from 60-360 cPs.
23. The method for preparing a coated article according to claim 22, wherein the coating of the article surface is carried out with a viscosity of the polyol component and a viscosity of the isocyanate component differing by no more than 10%.
24. The method for preparing a coated article according to any one of claims 19-23, wherein the article is made of a material selected from the group consisting of steel, cold-rolled steel, galvanized sheet, gypsum, tile, terracotta tile, fiberglass, wood, plywood, polymer, acrylic, plastic, unplasticized polyvinyl chloride, polyvinyl chloride (PVC), cement, concrete, glass, composite material, and a mixture thereof.
25. An article prepared according to the method for preparing a coated article according to any one of claims 19-24, which is a thermal insulation article.