Polyurethane systems

Abstract

The present invention relates to a liquid polyurea sealant for sealing a gap between a first and a second external construction element, said liquid polyurea sealant comprising: a) a polyisocyanate component comprising an aliphatic polyisocyanate; and b) a polyisocyanate-reactive component comprising a polyamine. In another aspect, the present invention provides a method for sealing a gap between a first and a second external construction element and a sealed structural assembly.

Description

[0001] Cross-references to other applications

[0002] none Background Technology

[0003] Sealing tape is a versatile and indispensable tool in numerous industries, from plumbing and construction to automotive and manufacturing. It plays a crucial role in ensuring leak-proof and secure connections.

[0004] There are many different types of sealing tapes. For example, butyl sealing tape, silicone sealing tape, silicone self-adhesive tape, sealant tape, and thread sealing tape.

[0005] However, currently available membrane or tape solutions typically exhibit weak adhesion strength to various substrates. Furthermore, most commercially available tapes only provide physical coverage. This can make it difficult to fill all gaps, especially in cases of complex joint structures. Failure to fill all gaps results in the joint not being fully isolated from air and / or moisture.

[0006] In addition, existing liquid sealing systems cannot achieve the required permeability or adhesive strength, and generally have poor adhesion to different substrates.

[0007] As energy costs rise and emission restrictions become more stringent, passive or near-zero energy buildings are gaining popularity, making it increasingly important to provide effective joint sealing solutions. Summary of the Invention

[0008] Therefore, there is a need for a sealing solution that has high adhesive strength, is easy to apply to complex structures, and provides good protection against air and moisture. Detailed Implementation

[0009] This invention will be described with reference to specific aspects and embodiments.

[0010] It should be noted that the term "comprising" as used in the claims should not be construed as limiting to the means listed below, and it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the stated feature, step, or component when mentioned, but does not exclude the presence or addition of one or more other features, steps, components, or a collection thereof. Thus, the scope of the expression "a mixture comprising components X and Y" should not be limited to mixtures consisting solely of components X and Y. For the purposes of this invention, it means that the only relevant components of the mixture are X and Y.

[0011] Throughout this specification, the phrase "in one embodiment" or "implementation" is used. Such a reference indicates that a particular feature described for that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily refer to the same embodiment, although they may refer to the same embodiment. Furthermore, it will be apparent to those skilled in the art that the specific features or performance described may be combined in any suitable manner in one or more embodiments.

[0012] It is understood that, in order to provide embodiments according to the invention, although preferred embodiments and / or materials have been discussed, various adjustments or changes may be made without departing from the scope and spirit of the invention.

[0013] The terms "preferred" and "ideally" refer to embodiments that provide certain benefits in specific circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, describing one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0014] When substituents are defined by their conventional chemical formula written from left to right, they also include chemically identical substituents that are produced when the structure is written from right to left, for example, -CH2O- is equivalent to -OCH2-.

[0015] The terms “optional” or “optionally” refer to events or situations described below that may or may not occur, and the description includes both scenarios in which the events or situations occur and scenarios in which they do not occur.

[0016] In this application, the term "about" is used to indicate that a value includes inherent error variations used to quantify the device, mechanism, or method, or inherent variations existing between the objects being measured. For example, but not limited to, when the term "about" is used, the value it refers to can vary by positive or negative 10%, or 9%, or 8%, or 7%, or 6%, or 5%, or 4%, or 3%, or 2%, or 1%, or one or more fractions therein.

[0017] As applied herein, the phrases “or combinations thereof” and “and combinations thereof” refer to all permutations and combinations of the items listed preceding the term. For example, “A, B, C, or combinations thereof” is intended to include at least one of the following: A, B, C, AB, AC, BC, or ABC, and, if the order is important in the particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing this example, explicitly included combinations contain repetitions of one or more items or terms, such as BB, AAA, CC, AABB, AACC, ABCCCC, CBBAAA, CABBB, etc. Those skilled in the art will understand that there is generally no limit to the number of items or terms in any combination unless it is obvious from the context. Similarly, when the terms “or combinations thereof” and “and combinations thereof” are used with the phrases “selected from” or “selected from the group consisting of…”, they refer to all permutations and combinations of the items listed preceding the phrase.

[0018] Unless otherwise stated, the term indefinite article is used to indicate one or more.

[0019] All references cited in this specification are incorporated herein by reference in their entirety. In particular, the teachings of all references specifically mentioned herein are incorporated herein by reference.

[0020] Unless otherwise defined, all terms used in disclosing this invention (including technical and scientific terms) have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. Definitions of terms are also included herein by way of instruction to better understand the teachings of this invention.

[0021] In this application, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect unless expressly stated otherwise. In particular, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous. While preferred embodiments of the invention have been disclosed for descriptive purposes, those skilled in the art will understand that various modifications, additions, or substitutions may be made without departing from the scope and spirit of the invention as disclosed in the appended claims.

[0022] In a first aspect, the present invention relates to a liquid polyurea sealant for sealing a gap between a first external structural element and a second external structural element, the liquid polyurea sealant comprising:

[0023] a. Polyisocyanate components containing aliphatic polyisocyanates; and

[0024] b. Polyisocyanate reactive components containing polyamines.

[0025] The aforementioned polyurethane sealant is a reactive system exhibiting excellent adhesive strength to a wide variety of matrices. Being a liquid-based system, it is also easier to handle compared to membrane or tape-based systems. Furthermore, due to its liquid-based nature, it possesses good flowability, easily filling all gaps between structural elements, regardless of the complexity of the structure. The system also provides consistent and durable airtightness and good permeability, typically superior to that of standard tapes or sealing strips.

[0026] Aliphatic polyisocyanates are used because they are low-reactivity polyurea systems. High molecular weight (Mw), low-functionality polyetheramines and polyols with high ethylene oxide (EO) content are used to improve water vapor permeability. If aromatic polyisocyanates are used, the physical properties of the sealant are often unsuitable. For example, tensile strength and elongation at break values ​​may be too low.

[0027] As used herein, the term "construction element" is used to refer to any element applicable to a construction.

[0028] The term "aliphatic" is intended to be used in its usual sense within this field. That is, it refers to or refers to organic compounds in which carbon atoms form open-chain structures (such as alkanes) rather than aromatic rings.

[0029] Polyisocyanates are any compounds that contain multiple isocyanate (-N=C=O) groups.

[0030] In some embodiments, the sealant contains at least about 50 wt%, preferably about 50-80 wt%, of aliphatic polyisocyanates based on the total weight of the polyisocyanate components.

[0031] When the amount of aliphatic polyisocyanate is within the above range, the moisture permeability and working time of the liquid sealant are within the required range.

[0032] In some embodiments, the sealant contains at least about 30 wt%, for example about 30-70 wt%, preferably about 40-60 wt%, of polyamines based on the total weight of the polyisocyanate reactive components.

[0033] In some embodiments, the liquid polyurethane sealant has a permeability (Sd value) of about 0.5-2.0 meters, preferably about 0.5-1.0 meters, at 23°C and 90% relative humidity. The Sd value, sometimes referred to as the µ-value, is a measure of the resistance to water vapor movement compared to the resistance of one meter of air. It can be measured by any method known to those skilled in the art. The Sd value can be calculated using water vapor permeability. Water vapor permeability is a measure of the passage of water vapor through a material. Also known as water vapor transmission rate (WVTR), it is essentially the mass of water vapor that passes through a measurement area in a specific time unit under specified temperature and humidity conditions. In some embodiments, WVTR can be measured using the cup method. The cup method is a method for independently testing water vapor permeability based on simple and straightforward principles. In short, a cup is filled with a solid desiccant or distilled water, leaving a small air space between it and the membrane. The porous material sample to be tested is properly sealed to the edge of the cup to prevent lateral diffusion. Take the initial weight of the cup, then place it in an environmental chamber and continuously measure the air temperature and relative humidity. Then weigh the test cup periodically.

[0034] In some embodiments, the aliphatic polyisocyanate is selected from hexamethylene diisocyanate, tetraalkylxylene diisocyanate, cyclohexane diisocyanate, 1,12-dodecane diisocyanate, 1,4-tetramethylene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4 -Dicyclohexylmethane diisocyanate, 2,2 -Dicyclohexylmethane diisocyanate, 2,4- -Dicyclohexylmethane diisocyanate, hydrogenated 4,4 - Diisocyanates, specifically dicyclohexylmethane (MDI) and mixtures thereof. Preferably, aliphatic polyisocyanates include isophorone diisocyanates and hydrogenated 4,4-diisocyanates. - Dicyclohexylmethane diisocyanate (MDI).

[0035] In some embodiments, the polyisocyanate component includes a semi-prepolymer or prepolymer formed by reacting an aliphatic polyisocyanate with a polyol.

[0036] In some embodiments, the polyol comprises a polyether polyol. For example, the polyether polyol may be selected from polyethylene glycol, polypropylene glycol, polypropylene glycol-ethylene glycol copolymer, polybutanediol, polyhexanediol, polyheptanediol, polydecanediol, and mixtures thereof.

[0037] In some embodiments, the polyamine comprises a polyoxyethylene polyamine compound having the following formula (I):

[0038] (I)

[0039] Q It is a compound containing isocyanate reactive hydrogen used as an initiator, after removing at least one isocyanate reactive hydrogen, leaving a multivalent residue, y It is an integer of at least 2, each R Independently hydrogen, methyl, ethyl or propyl, and x It is an integer of at least 1.

[0040] In some implementations, each R The group is independently selected from hydrogen or methyl, y x is an integer between 2 and 8. It is an integer from 1 to 40.

[0041] In some embodiments, the polyisocyanate reactive component further includes at least one of polyether polyol, polyester polyol, polycarbonate polyol, chain extender, and polycaprolactone polyol.

[0042] In some embodiments, the polyisocyanate also includes fillers. Examples of suitable fillers include, but are not limited to, CaCO3, BaSO4, fumed silica, thixotropic agents such as hydrogenated castor oil, defoamers, wetting agents, catalysts, plasticizers, silane coupling agents, pigments, and combinations thereof.

[0043] In some embodiments, the polyisocyanate component comprises about 0-60 wt%, preferably about 20-50 wt%, of filler, based on the total weight of the polyisocyanate component.

[0044] The addition of fillers can improve the physical properties of liquid polyurea sealants and the resulting cured sealants.

[0045] In some embodiments, the polyisocyanate reactive component comprises about 0-80 wt%, preferably about 30-70 wt%, of filler, based on the total weight of the polyisocyanate reactive component.

[0046] In some embodiments, the polyisocyanate reactive composition further comprises at least one of the following: a thixotropic agent, an antifoaming agent, a wetting agent, a catalyst, a plasticizer, a silane coupling agent, and a pigment.

[0047] In some embodiments, the liquid polyurea sealant has an elongation at break of about 400% or more, preferably about 400-600%. Elongation at break is a measure of the ductility of a material. This measurement represents the extent to which a material can be stretched before fracture, expressed as a percentage of its original size. It indicates the material's ability to withstand significant deformation before failure. Elongation at break can be measured using any method known to those skilled in the art.

[0048] In some embodiments, the liquid polyurea sealant has a tensile strength of about 5 MPa or higher, preferably about 6-10 MPa. High tensile strength is important for materials that are about to be stretched or are under stretching. Tensile strength can be measured by any method known to those skilled in the art. For example, a film can be prepared and cured at 23°C and 50% RH for 7 days. The film can then be cut into dumbbell-shaped pieces as required by G / T 328.9 or BS EN ISO 1421:2016. The test pieces are stretched at a constant tensile rate until they break. The maximum force and elongation at break are recorded.

[0049] In another aspect, the present invention provides a method for sealing a gap between a first external structural element and a second external structural element, the method comprising:

[0050] The gap was filled with the above-described liquid polyurea sealant; and

[0051] A cured material is formed by reacting the first polyisocyanate component with the polyisocyanate reactive component.

[0052] In another aspect, the present invention provides a sealing structure assembly prepared according to the above method.

[0053] In one embodiment, both the first and second external structural elements include building panels. For example, building panels may include engineered wood, timber, cement, fiber cement, mortar, glass, brick, metal, stone, concrete, composite materials, foam, plastics, or combinations thereof.

[0054] In one embodiment, the first external structural element includes a window frame and the second external structural element includes window panes or building panels.

[0055] In one aspect, the present invention provides a liquid polyurea sealant for sealing a gap between a first external structural element and a second external structural element, the liquid polyurea sealant comprising:

[0056] a) A polyisocyanate component, comprising at least about 50 wt% aliphatic polyisocyanates based on the total weight of the polyisocyanate component; and

[0057] b) The polyisocyanate reactive component, comprising, by weight of the total polyisocyanate component, at least about 30 wt% of a polyamine, and

[0058] The liquid polyurea sealant has an SD value of about 0.5-1.0 meters, preferably about 0.7-0.8 meters.

[0059] In some embodiments, the liquid polyurea sealant has an elongation at break of about 400% or more, preferably about 400%-600%. Elongation at break is a measure of the ductility of a material. This measurement represents the extent to which a material can be stretched before fracture, expressed as a percentage of its original size. It indicates the material's ability to withstand significant deformation before failure. Elongation at break can be measured using any method known to those skilled in the art.

[0060] In some embodiments, the liquid polyurea sealant has a tensile strength of about 5 MPa or higher, preferably about 6-7 MPa. High tensile strength is important for materials that are about to be stretched or are under stretching. Tensile strength can be measured by any method known to those skilled in the art. For example, a film can be prepared and cured at 23°C and 50% RH for 7 days. The film can then be cut into dumbbell-shaped pieces as required by G / T 328.9 or BS EN ISO 1421:2016. The test pieces are stretched at a constant tensile rate until they break. The maximum force and elongation at break are recorded.

[0061] In some embodiments, the adhesive strength of the liquid polyurea sealant is greater than about 0.6 kN / m. Adhesive strength can be measured using any method known to those skilled in the art. For example, an adhesive peel test can be applied.

[0062] In some embodiments, the polyisocyanate reactive component further comprises at least one of polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol.

[0063] In some embodiments, the polyisocyanate reactive component further comprises at least one of the following: thixotropic agent, defoamer, plasticizer, leveling agent, silane coupling agent, catalyst, thickener, water remover, pigment, and combinations thereof.

[0064] In some embodiments, the additive is present in the polyisocyanate reactive component in an amount of about 0-15 pph, preferably about 2-10 pph.

[0065] In one aspect, the present invention provides a sealant system comprising:

[0066] a) The liquid polyurethane sealant as described above; and

[0067] b) A liquid polyurea sealant for sealing the gap between the first internal structural element and the internal structural element, the liquid polyurea sealant comprising:

[0068] i) Polyisocyanate components containing aromatic polyisocyanates; and

[0069] ii) Polyisocyanate reactive components containing polyether polyols and / or hydrophobic polyols.

[0070] Example

[0071] Further details and advantages will become apparent from the following examples.

[0072] Liquid polyurethane resins were prepared using the compositions described in Table 1 below. The following components were used:

[0073]

[0074] The prepolymer is prepared by adding isocyanate and isocyanate reactive components to a reactor in a specified ratio, stirring and maintaining the temperature at 75°C for 2 hours to obtain the final prepolymer resin.

[0075] A film was prepared by mixing a polyisocyanate component and a polyisocyanate reactive component in a specified ratio. The resulting mixture was then coated onto a Telflon® plate to obtain a film with a thickness of 0.6–1.0 mm. The film was stored at 23°C and 50% relative humidity for 7 days. The physical properties of the film were then tested.

[0076] Tensile strength (MPa) and elongation (%) were tested according to GB / T 328.9 “Test methods for building sheets for waterproofing - Part 9: Plastic and rubber sheets for waterproofing - tensile properties (method B)”. In short, the film was prepared and tested after curing at 23°C and 50% relative humidity for 7 days. The film was then cut into specified dumbbell-shaped pieces according to G / T 328.9 or BS EN ISO 1421:2016. The test pieces were stretched at a constant rate until breakage. The maximum force and elongation at break were recorded.

[0077] Applying GB / T 2790 "Adhesives", The peel strength test method for a flexible-bonded-to-rigid test specimen assembly specifies the method for testing the adhesive strength to different matrices. Adhesion tests to different matrices should be performed using GB / T 2790 or EN ISO 8510-2 standards. In short, these include tests for flexible bonding of adhesives to rigid test specimen assemblies. Peel strength test method. The polyisocyanate component and the polyisocyanate reactive component are mixed in a specified ratio to obtain a resin. The resin is then coated onto the surface of the substrate to be tested to a thickness of approximately 0.8-1.0 mm. After curing at 23°C for 7 days, the peel strength is measured using a tensile testing machine. This can cause the resin film to peel off from the substrate, leading to adhesion or substrate failure.

[0078] Water vapor permeability (Sd) was tested according to the procedures specified in GB / T 17146 "Test methods for water vapor transmission properties of building materials and products" or BS EN ISO 12572:2016 "Hygrothermal performance of building materials and products". The cup method was applied as described above. Films with a thickness of 0.7-1.0 mm were prepared by curing the resin at 23°C and 50% relative humidity for 7 days. The water vapor flow rate of the samples was tested at 23°C and 90% humidity. The Sd value was then calculated.

[0079] The performance values ​​are shown in Table 2.

[0080] The results in Table 2 confirm that the liquid polyurea sealant of the present invention has excellent moisture permeability, appearance, strength and adhesion.

[0081] Table 1: Composition of the sealant system

[0082]

[0083] Table 2: Performance of the sealant system

[0084]

Claims

1. A liquid polyurea sealant for sealing a gap between a first external structural element and a second external structural element, the liquid polyurea sealant comprising: a) Polyisocyanate components containing aliphatic polyisocyanates; and b) Polyisocyanate reactive components containing polyamines.

2. The liquid polyurea sealant of claim 1, wherein the aliphatic polyisocyanate is selected from hexamethylene diisocyanate, tetraalkylxylene diisocyanate, cyclohexane diisocyanate, 1,12-dodecane diisocyanate, 1,4-tetramethylene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4 -Dicyclohexylmethane diisocyanate, 2,2 -Dicyclohexylmethane diisocyanate, 2,4- - Dicyclohexylmethane diisocyanate and mixtures thereof.

3. The liquid polyurea sealant of claim 1, wherein the polyisocyanate component comprises a semi-prepolymer or prepolymer formed by reacting an aliphatic polyisocyanate with a polyol.

4. The liquid polyurea sealant of claim 3, wherein the polyol comprises a polyether polyol.

5. The liquid polyurea sealant of claim 4, wherein the polyether polyol is selected from polyethylene glycol, polypropylene glycol, polypropylene glycol-ethylene glycol copolymer, polybutanediol, polyhexanediol, polyheptanediol, polydecanediol, and mixtures thereof.

6. The liquid polyurea sealant of claim 1, wherein the polyamine comprises a polyoxyethylene polyamine compound having the following formula: Q It is a compound containing isocyanate reactive hydrogen used as an initiator, after removing at least one isocyanate reactive hydrogen, leaving a multivalent residue, y For at least 2, each R Independently hydrogen, methyl, ethyl or propyl, and x It must be at least 1.

7. The liquid polyurea sealant of claim 6, wherein each R The group is independently hydrogen or methyl, y x is an integer between 2 and 8. It is an integer from 1 to 40.

8. The liquid polyurea sealant of claim 1, wherein the polyisocyanate reactive component further comprises at least one selected from polyether polyol, polyester polyol, polycarbonate polyol, chain extender, and polycaprolactone polyol.

9. The liquid polyurea sealant of claim 1, wherein the polyisocyanate further comprises fillers including CaCO3, BaSO4 and fumed silica.

10. The liquid polyurea sealant of claim 1, wherein the polyisocyanate reactive component further comprises at least one of the following: a thixotropic agent, an antifoaming agent, a wetting agent, a catalyst, a plasticizer, a silane coupling agent, and a pigment.

11. A method for sealing a gap between a first external structural element and a second external structural element, comprising: The gap is filled with the liquid polyurea sealant according to any one of claims 1-10; and A cured material is formed by reacting the first polyisocyanate component with the polyisocyanate reactive component.

12. A sealing structure assembly produced according to the method of claim 11.

13. The sealing structure assembly of claim 12, wherein both the first external structural element and the second external structural element comprise building panels.

14. The sealing structure assembly of claim 13, wherein the building panel comprises engineered wood, timber, cement, fiber cement, glass, brick, metal, stone, concrete, composite material, foam, plastic, or a combination thereof.

15. The sealing structure assembly of claim 12, wherein the first external structural element comprises a window frame and the second external structural element comprises window pane glass or building panel.

16. A liquid polyurea sealant for sealing a gap between a first external structural element and a second external structural element, the liquid polyurea sealant comprising: a. A polyisocyanate component, comprising at least about 50 wt% aliphatic polyisocyanates based on the total weight of the polyisocyanate component; and b. The polyisocyanate reactive component, comprising, by weight of the total polyisocyanate component, at least about 30 wt% of a polyamine, and The SD value of the liquid polyurea sealant is approximately 0.5-2.0 m.

17. The liquid polyurea sealant material of claim 16, wherein the liquid polyurea sealant has at least one of the following: an elongation of about 400% or more, a tensile strength of about 5 MPa or more, and an adhesive strength of about 0.6 kN / m or more.

18. The liquid polyurea sealant of claim 17, wherein the polyisocyanate reactive component further comprises at least one selected from polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol.

19. The liquid polyurea sealant of claim 16, wherein the polyisocyanate reactive component further comprises at least one of the following: a thixotropic agent, an antifoaming agent, and a pigment.

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