SI23731A - Adhesive/sealant preferably used for construction panels - Google Patents

Abstract

Adhesive sealant with reduced thermal conductivity for insulating windows and gas-filled insulating building panels is an adhesive sealant which incorporates hollow mineral and or organic microspheres into its structure. Thermal conductivity of such a mass is below W mK preferably below WmK. The chemical and mechanical properties of such an adhesive sealant are comparable to conventional cults used for insulating windows and gas-filled insulating building panels

Description

The field of technology

Thermal insulation, building panels, adhesives / sealants

ECLA: C08J3 / 20H, E06B3 / 56, C09K3 / 10D8, C09K3 / 10F

A technical problem

A technical problem solved by the present invention according to the invention is brand new and is a low-conductivity adhesive / sealant kit for insulating glass and gas-filled building panel insulators. The adhesive / sealant kit has at least the same chemical and mechanical properties as those of the prior art but with lower thermal conductivity. It should be below 0.30 W / mK

The state of the art

A building panel is one or more chamber insulated window glass or a gas-filled insulating building panel intended for use in building envelopes - integrated and suspended facades and windows. It must be sealed with adhesive / sealant. Adhesives / sealants are most commonly in the form of adhesive / sealants.

Adhesive / sealant putties are well known in the field of insulating windows or gas-filled insulating panels, where they are used to fix a metal frame between two panels and inhibit gas leakage from the insulation core. The thermal resistance of such windows or. panels are very important because of the need to reduce energy consumption. One of the directions of development so far has been to reduce the thermal transmittance of the metal frame, or. spacers using hybrid (metal-plastic) materials. Today, these spacers already reach the technically feasible limit of reduced thermal transmittance, so that the contribution to the thermal transmittance of the sealant / adhesive applied over them is already greater than that of the spacers themselves. The thermal conductivity of these sealing / adhesive kits is today from 0.35 to 0.40 W / mK.

In the prior art, requirements for adhesive / sealant tendons of thermal insulation panels are known, which are:

• adhesion with cohesive glass, aluminum, stainless steel, tensile strength 0.6 to 1.2 MPa (SIST EN 28339) • 30 to 60 Shore A hardness (ISO 868) • at least 50% elongation (SIST EN 28339) • Leakage resistance of 0 mm (SIST EN 27390) • Continuous load test: tensile strength 0.30 MPa for 10 minutes (SIST EN 12796; applies only to those with CE marking for production)

There are three groups of relevant patents in the prior art. The first presents sealing putties based on polymers such as polysulfide, polymercaptans, silicones, polyurethanes and intended for use in construction, specifically as a secondary seal for insulating window panes or gas-filled insulators of building panels intended for use in building casings - integrated and suspended facades and windows: US2543844, US2589151, US4153594, US3689450, US6919397, CA2085077, EP1044936, US5430192, EP0097005, EP0010888. Today, the most commonly used sealing kit based on liquid polysulfide polymer, selected plasticizer and adhesion promoter, usually from the group of silanes, is used for these purposes. The polysulfide mixture is then solidified with a hardener such as manganese dioxide. By adding to the polysulfide mixture copolymers based on epoxy, polythioether, polyurethane, polymercaptan etc. mechanical properties and gas and / or the steam tightness of the final sealing putty.

The second group presents sealants which, by incorporating hollow microspheres into their structure, achieve a lower density: US4582756, US6915987, US7067612. In the same group are patents that present sealants that, by incorporating hollow microspheres in their structure, achieve lower density and better mechanical properties such as tensile strength, tensile strength, higher elasticity, fuel resistance: US20040097643, W02010019561, US5663219 .

US20040097643 describes the preparation of low density seals (0.7 to 1.3

Ί g / cm) with improved tensile strength. To achieve a lower density of seals, they suggest the use of full and hollow fillers that have a lower density than the basic sealing material. Full and hollow fillers can be mineral (ceramic, glass) or organic. It is interesting to note that by introducing such fillers into the polymer sealant, they also achieved better mechanical properties (tensile and tensile strength), which is contrary to the previous practice when it was applied: the higher the tensile strength, the lower the tensile strength. With this invention, this correlation is shattered, and the reason for this is stated by the authors in the introduction of appropriate fillers. Low density solidified or uncured sealants are suitable for use in various fields: aerospace, transport (trains, ships, vehicles), mechanical engineering, structures and construction - wherever mass reduction is important. However, said mass has not been tested for use in the field of insulating windows and gas-filled insulators of building panels. Thus, the patent authors did not address the question of whether their sealants slow down the permeation of gases (water vapor, argon), which is crucial in the field of insulation windows and gas-filled insulating building panels. From their patent it cannot be deduced that according to their invention the desired thermal conductivity of the sealants can be achieved, since their product was not intended for energy-efficient construction.

In the third group is a single patent US7569626, which addresses the use of hollow or gas-filled glass or ceramic microspheres to achieve a lower thermal conductivity of a biocompatible polymer intended for use in medical therapies, where it is overheated due to electrical conductivity. The patent does not mention the thermal conductivity of the polymer thus prepared, but defines a thermal conductivity of fillers of less than 5 W / mK, preferably less than 2 W / mK. This patent is very remote in terms of our technical field as it relates to biocompatible polymers, for use in medicine. In our research, we have developed a polymer adhesive / sealant with reduced thermal conductivity for use in construction, where specific technical and mechanical properties are required for the purpose of use. It cannot be deduced from the aforementioned patent that the protected polymer mass meets the key technical requirements for use as a secondary seal in insulating windows and gas-filled insulating building panels, such as: tensile strength> 0.6 MPa, tear elongation> 50%, hardness after Shoru A> 30.

Description of the new solution

Adhesive / sealant, preferably for use in the building panel, solves the new technical problem shown above by way of an astonishing technical effect, inter alia by sealing the edges with a polysulfide or silicone based sealant. The thermal conductivity of this adhesive / sealant is less than 0.30 W / mK, preferably less than 0.25 W / mK. Further, this adhesive / sealant contains organic and / or mineral hollow microspheres.

The adhesive / sealant according to the invention is made on the basis of polysulfide or silicone and / or their derivatives and has hollow mineral and / or organic microspheres and other fillers which can achieve a low thermal conductivity mass.

The invention will be described in more detail based on the findings of the research and the embodiments. It was found that at thermal conductivity <0.30 W / mK, a significant improvement in the thermal resistance of the edge of the insulating glass and the gas-filled insulating building panel was observed. By further reducing the thermal conductivity of the secondary sealant, the thermal resistance of the edge of the insulating glass and the gas-filled insulating panel is improved, but the thermal conductivity of the sealant is approximately 0.25 W / mK to achieve the desired mechanical properties of the sealant and the economics of the product.

Reduced thermal conductivity of the adhesive / sealant is achieved with the least technical effort if the adhesive / sealant is added or replaced by a portion of the fillers with hollow mineral and / or organic microspheres.

The hollow microspheres are expanded closed cell structures or hollow fillers of spherical or egg-shaped size ranging from 5 to 500 pm. Hollow microspheres can also be filled with gas (eg: CO2, Ar). The hollow microspheres can be mineral based (glass, ceramic) or organic polymers (PE, PU, PS, PMMA). Examples of suitable hollow mineral microspheres are: Eurocell from Europerl, E-spheres from Envirospheres. An example of suitable hollow organic microspheres is Expancel by Akzo Nobel.

The minimum size of hollow mineral microspheres available on the market is 5 pm and the maximum size is up to 500 pm. The minimum size of hollow organic microspheres available on the market is 10 pm and the maximum size is up to 1000 pm. In our case, it is not desirable that the mixture is dominated by the smallest hollow mineral and organic microspheres, since their thermal conductivity is significantly higher than that of the large microspheres. However, we must also be aware of the limitations on the maximum sizes of the microspheres, which are conditioned by the technical limitations of the application hardware. In the field of insulating windows and gas-filled insulating panels, two-component adhesive / sealants are typically used to fix the metal frame between the two panels and prevent gas from escaping from the insulation core, as they offer significantly better vapor and gas closures than one-component adhesives / sealants. Fillers incorporated in two-component adhesives / sealants should not exceed 500 pm in size, as this could lead to clogging or clogging. malfunctioning of hardware locking elements. Abrasive damage in the mixing and dosing systems is even more of a problem, as they are magnified by the size and number of solids. In the case of mineral hollow microspheres, the fragility of the microspheres, which can break even at high pressures and mixing speeds, poses additional problems.

Research has shown that the size of the hollow microspheres is up to 300 pm. The thickness of the secondary seal layer is up to 4 mm for insulating windows and gas-filled insulation panels. It is experienced that particles must be at least 10 times smaller than the thickness of the coating in order to achieve the appearance of a uniform application of the secondary seal. However, if the demand for a smoother secondary seal is required, the microspheres must be even smaller, below 150 pm or even below 100 pm.

Particle size - microspheres and fillers - affects the mechanical and thermal properties of the adhesive / sealant. The larger the particles, the lower the adhesive / sealant strength. The cause is a larger notch effect on each particle. However, the larger the hollow microspheres, the lower the thermal conductivity of the mass, since the hollow microspheres have a significantly lower thermal conductivity (<0.062 W / mK) than the thermal conductivity of conventional adhesive / sealant (> 0.35 W / mK), which used as a secondary seal for insulation windows and gas-filled insulation panels.

The opposite applies to full fillers such as calcium carbonate (calcite, chalk), calcium sulfate (gypsum), clay, mica and others. The reason for the use of fillers in sealants is in the price, because by adding them, the adhesive / sealant is significantly reduced. Adhesive / sealant without fillers would be commercially uninteresting due to the high price. At the same time, with the addition of fillers, we also achieve the desired tensile modulus, which means that by correlating the fillers we can obtain the desired hardness, tensile strength, adhesion and viscosity, which the adhesive / sealant for the scope in insulating windows and gas-filled panels for construction . Typically, secondary sealants for insulating windows and gas-filled panels contain 35 - 50 wt. % of liquid components and 50 - 65 wt. % fillers, most commonly CaCO3, which may be untreated and granular (GCC) or treated and precipitated (PCC). Depending on the crystal structure and shape, calcium carbonate may have a thermal conductivity of 2.4 to 9 W / mK, which means that the higher the calcium carbonate particles and the higher the adhesive / sealant content, the higher its thermal conductivity. The proportion of PCC filler is usually in a mixture of 5-15 wt. %, And GCC fill 50-60 wt. %. Since hollow microspheres were used as a substitute for the filler in the present invention, the proportion of other fillers, and in particular CaCCb, was significantly altered in order to achieve the desired mechanical properties.

The study showed that for thermal conductivity of adhesive / sealant below 0.30 W / mK, a minimum of 5 volumes of conventional fillers in adhesive / sealant need to be replaced with hollow microspheres. Of course, the standard mass ratio between the liquid and solid components in the adhesive / sealant is broken, since the hollow microspheres have a significantly lower density and a significantly larger specific surface, which makes it necessary to bring more liquid components, especially the polymer, to mix the hollow microspheres in the adhesive. / sealant.

By increasing the proportion of hollow microspheres in the adhesive / sealant, the brittleness of the mass increases. decreases its elasticity and significantly increases viscosity and thixotropy. In order to achieve the target adhesive / sealant properties that still meet the intended use by the standards, it is necessary to increase the proportion of polymer and even more the proportion of elastic additives. However, there is also a critical point here, as elasticity additives reduce the adhesive / sealant's adhesion to metals, glass, plastic for spacers and gypsum boards.

With our research we have shown that the upper limit of the hollow microsphere content is 60% by volume with respect to the total sealing mass. At this content, the adhesive / sealant barely flows at the beginning of the curing process, but when cured it meets the required conditions prescribed by the standard for the scope in insulating windows and gas-filled insulation panels.

However, there is an optimum volume fraction of organic and mineral microspheres in the adhesive / sealant from a mass workability, cost, and fire response point of view. As mentioned above, as the volumes of hollow microspheres increase, the viscosity increases, requiring more powerful mixing and pumping equipment, while also increasing the proportion of polymer and elastic additives that significantly contribute to raising the price of the final product. From the standpoint of fire, only the organic microspheres are critical, as they contribute to the combustion enthalpy of adhesive / sealant, while the mineral microspheres reduce the combustion enthalpy of adhesive / sealant. In our study, the optimum amount of hollow organic microspheres was between 20 and 40% by volume relative to the total adhesive / sealant mass, and for hollow mineral microspheres between 10 and 30% by volume relative to the total adhesive / sealant mass. This is also the area where the required mechanical properties of adhesive / sealant and thermal conductivity below 0.25 W / mK are easily achieved.

Organic and mineral microspheres can also be used together in a sealant. The advantage of organic microspheres is that they significantly lower our thermal conductivity than inorganic microspheres and are less sensitive to the mixing system. The advantage of mineral microspheres is that they reduce the enthalpy of combustion. The regularities of the proportion of both types of microspheres in the adhesive / sealant are similar to those of each type of microspheres. Implementation examples

Example 1:

We prepared 2 component adhesive / sealant based on polysulfide. The composition of component A by weight and by volume is given in Table 1.

Table 1:

Share by weight Volume fraction Thiokol LP-23 (Toray) 27,4 38.13 Santicizer 261A (Ferro) 10,20 20,28 Silan A-187 (Crompton Corporation) 0.55 0.90 Isostearic Acid (Samson Kamnik) 0.03 0.05 Calcium Carbonate (Omya) 61.91 40.64

The raw materials listed in Table 1 were mixed at room temperature on a DREIS IL planetary agitator at 60 rpm. Liquid components were first mixed (3 5 min) and then calcium carbonate was added in steps from the finest to the coarsest. After all the fillings were mixed, they were subsequently stirred for a further 20 min under vacuum.

We separately prepared component B with the composition listed in Table 2.

Table 2

Share by weight Volume fraction Manganese Dioxide (Shepherd) 30 30,1 Tetramethyl-tiuran disulfide (TMTD) (Lanxess) 1.67 1.99 Santicizer 278 (Ferro) 53.18 74.68 Calcium Carbonate (Omya) 10.03 5.74 Soot Printex 30 (Evonik) 5.02 4.31

The raw materials for component B preparation were prepared by mixing on a SPEED MIXER FVZ 400 laboratory mixer at 2000 rpm for 2 seconds each. The mass was stirred by hand between the two mixes.

Then, 100 parts by weight of component A (Table 1) and 9 parts by weight of component B (Table 2) were mixed to give a homogeneous mixture that was suitable for preparing test pieces for mechanical tests and for measuring thermal conductivity. We waited 168 hours for the mixture to solidify completely (in accordance with the standards) and then performed the tests. The results are summarized in Table 6.

Example 2:

We prepared 2 component adhesive / sealant based on polysulfide into which hollow mineral microspheres were mixed. The composition of component A by weight and by volume is given in Table 3.

Table 3:

Share by weight Volume fraction Thiokol LP-23 (Toray) 44.09 48,00 Benzoflex 2088 (Genovique) 13,20 20,39 Silan A-187 (Crompton Corporation) 0.59 0.75 Vinyltris (2-methoxyethoxy) silane (Degussa) 0.29 0.38

Isostearic Acid (Samson Kamnik) 0.02 0.03 Calcium Carbonate (Omya) 39.61 20.56 Eurocell 140-23 (Europerl) 2.2 10.09

The raw materials listed in Table 3 were mixed at room temperature on a DREIS 1L planetary agitator at 60 rpm. Liquid components were first mixed (3 5 min) and then calcium carbonate was added in steps from the finest to the coarsest. After all the fillings were mixed, they were subsequently stirred for a further 20 min under vacuum. Finally, Eurocell 140-23 microspheres were added. They were stirred for 1 min and further for 5 min under vacuum.

The resulting homogeneous mass was solidified with the B component, which was prepared according to the same procedure as described in Example 1 (Table 2).

We then mixed 100 parts by weight of component A (Table 3) and 16 parts by weight of component B (table 2) to obtain a homogeneous mixture that was suitable for preparing the test specimens for mechanical tests and for measuring thermal conductivity. We waited 168 hours for the mixture to solidify completely (in accordance with the standards) and then performed the tests. The results are summarized in Table 6.

Example 3:

We prepared 2 component adhesive / sealant based on polysulfide into which the organic hollow microspheres were mixed. The composition of component A by weight is given in Table 4.

Table 4:

Share by weight Volume fraction Thiokol LP-23 (Toray) 36.66 23,43 Santicizer 261A (Ferro) 12.17 9.59 Silan A-187 (Crompton Corporation) 0.57 0.43 Vinyltris (2-methoxyethoxy) silane (Degussa) 0.29 0.22 Isostearic Acid (Samson Kamnik) 0.04 0.04 Calcium Carbonate (Omya) 48.69 14.91 Expancel 461 DET 40 d25 (Akzo Nobel) 1.58 51.38

The raw materials listed in Table 4 were mixed at room temperature on a DREIS IL laboratory planetary agitator at 60 rpm. Liquid components were first mixed (3-5 min). Expancel 461 DET 40 d25 was mixed as the first filler of the session, followed by the addition of calcium carbonate in steps from the finest to the coarsest. After all the fillings were mixed, they were subsequently stirred for a further 20 min under vacuum.

The resulting homogeneous mass was solidified with the B component, which was prepared according to the same procedure as described in Example 1 (Table 2).

Subsequently, 100 parts by weight of component A (Table 4) and 13 weight parts of component B (Table 2) were mixed to give a homogeneous mixture that was suitable for preparing the test specimens for mechanical tests and for measuring thermal conductivity. We waited 168 hours for the mixture to solidify completely (in accordance with the standards) and then performed the tests. The results are summarized in Table 6.

Example 4:

We prepared 2 component adhesive / sealant based on polysulfide into which organic and mineral hollow microspheres were mixed. The composition of component A by weight is given in Table 5.

Table 5:

Share by weight Volume fraction Thiokol LP-23 (Toray) 33.05 26,8 Benzoflex 2088 (Genovique) 15.7 18.5 Silan A-187 (Crompton Corporation) 0.66 0.64 Vinyltris (2-methoxyethoxy) silane (Degussa) 0.33 0.32 Isostearic Acid (Samson Kamnik) 0.02 0.03 Calcium Carbonate (Omya) 47.1 18,32 Eurocell 140-23 (Europerl) 2.48 8.51 Expancel 461 DET 40 d25 (Akzo Nobel) 0.66 26.88

The raw materials listed in Table 5 were mixed at room temperature on a DREIS IL planetary agitator at 60 rpm. Liquid components were first mixed (3 5 min). Expancel 461 DET 40 d25 was mixed as the first filler of the session, followed by the addition of calcium carbonate in steps from the finest to the coarsest. After all the fillings were mixed, they were subsequently stirred for a further 20 min under vacuum. Finally, Eurocell 140-23 microspheres were added. They were stirred for 1 min and further for 5 min under vacuum.

The resulting homogeneous mass was solidified with the B component, which was prepared according to the same procedure as described in Example 1 (Table 2).

We then mixed 100 parts by weight of component A (Table 5) and 12 parts by weight of component B (table 2) to obtain a homogeneous mixture that was suitable for preparing the test specimens for mechanical tests and for measuring thermal conductivity. We waited 168 hours for the mixture to solidify completely (in accordance with the standards) and then performed the tests. The results are summarized in Table 6.

Table 6:

Example 1 Example 2 Example 3 Example 4 Tensile strength (SIST EN 28339) [MPa] 1.0 0.9 0.6 0.8 Shore A Hardness (ISO 868) 55 50 34 49 Tensile elongation (SIST EN 28339) [%] 110.5 105,6 67,7 92.5 Resistance to leakage (SIST EN 27390) [mm] 0 mm 0 mm 0 mm 0 mm Continuous load test (SIST EN 1279-6) [min] 60 28 / 18 Thermal conductivity [W / mK] 0.40 0.25 0.20 0.23

For CBS INSTITUTE, Comprehensive Building Solutions, d.o.o. and TKK Manufacture of chemical products Srpenica ob Soči

d.d.

'atZntni agent

Claims (8)

1. Adhesive / sealant, preferably for use in a panel for use in building, sealed at the edges with adhesive / sealant, characterized in that the adhesive / sealant is based on polysulfide or silicone, further that thermal conductivity adhesive / sealants less than 0.30 W / mK, preferably less than 0.25 W / mK and further that the adhesive / sealant contains organic and / or mineral hollow microspheres. Adhesive / sealant according to claim 1, characterized in that the adhesive / sealant contains hollow microspheres based on organic polymers in the size of 10-300 pm, preferably 10-150 pm, more preferably 10-100 pm. Adhesive / sealant according to claim 2, characterized in that the adhesive / sealant contains 5 vol. % to 60 vol. and preferably between 20% vol. % and 40% vol. % of hollow microspheres per total volume of adhesive / sealant. Adhesive / sealant according to claim 1, characterized in that the adhesive / sealant contains mineral hollow microspheres of size 5 -300 pm, preferably 5-150 pm, and more preferably 5-100 pm. Adhesive / sealant according to claim 4, characterized in that the adhesive / sealant contains 5 vol. % to 60 vol. and preferably between 10% vol. % and 30% vol. % of hollow microspheres per total volume of adhesive / sealant. Adhesive / sealant according to claim 1, characterized in that the adhesive / sealant contains hollow microspheres based on organic polymers and mineral polymers. Adhesive / sealant according to claim 6, characterized in that the adhesive / sealant contains hollow microspheres based on organic polymers of size 10 - 300 pm, preferably 10 - 150 pm, more preferably 10 - 100 pm and mineral hollows «· Microspheres in size 5 - 300 μπι, preferably 5-150 μηι, more preferably 5 100 pm. Adhesive / sealant according to claim 6, characterized in that the adhesive / sealant contains 5 vol. % to 60 vol. % of hollow mineral and organic microspheres per total volume of adhesive / sealant. For CBS INSTITUTE, Comprehensive Building Solutions, d.o.o. and TKK Manufacture of chemical products Srpenica ob Soči d.d.