MX2013008937A

MX2013008937A - Composite elements.

Info

Publication number: MX2013008937A
Application number: MX2013008937A
Authority: MX
Inventors: Manfred Genz; Frank Fechner; Markus Schuette
Original assignee: Basf Se
Priority date: 2011-03-04
Filing date: 2012-02-29
Publication date: 2013-10-01
Also published as: EP2681044A1; WO2012119892A1; JP2014508057A; ZA201307355B; KR20140009451A; AU2012224772B2; IN2013CN06932A; CN103402754A; BR112013019576A2; AU2012224772A1; RU2013144410A

Abstract

The invention relates to a composite element containing a) a core made of a foam or a porous material, b) a top coat applied to the core a), and c) a film c) which differs from the top coat b) and is made of a thermoplastic material.

Description

COMPOSITE ELEMENTS * Field of the invention The invention relates to composite elements consisting of a core covered with a plastic sheet made of foam or a porous material.

BACKGROUND OF THE INVENTION The composite elements made of a foam core surrounded by at least one outer layer are well known. They have decorative functions, although they are preferably used for thermal insulation, for example in buildings or in refrigeration equipment.

Refrigeration equipment is very important both in the commercial sector and in the private sector. It is mostly produced by manufacturing a cover into which is introduced a liquid mixture made of a rigid polyurethane foam system, and the system hardens on the cover to give the polyurethane.

"Vacuum insulation panels" also abbreviated as VIPs, have been used in recent times to reduce thermal conductivity. These, too, in !: their majority are introduced in the covers and are surrounded with rigid polyurethane foam.

These processes are inconvenient. Particularly when VIPs are incorporated, a fixation process is necessary.

During transport and during the subsequent handling, and also during the process of foaming around the VIPs, there is also the risk of damage to the VIPs, for example in the region of the welds.

The Permaskin process is a method known for the use of a plastic sheet to wrap substrates. It is described by way of example in WO 01/32400. :: | Here, a molding is placed in a chamber between two thermoplastic sheets separated from each other, and fixed, and then the air is evacuated from the chamber, and the sheet is consequently compressed on the surface of the molding, while: ::: a gap between the sheets is maintained. The sheet here is preferably heated, in particular at a temperature above the softening point of the sheet.; '·;;' · The rigid polyurethane foams used- in 'the thermal insulation / low temperature sector too'; they can be used in theory as a substrate. The application [WO 2008/135550 describes this. The bilaterally coated rigid foam elements produced in this way exhibit an increased holding capacity, breaking strength,; and resistance to weathering, and also improved sensation ^ j and barrier action with respect to the ingress of liquids. :: The given example has a rigid foam made of Neopolen. Reference is made to the fact that foams can be used! 'of rigid polyurethane. The rigid foams used ?? ' you h! no additional previously applied functional layer.

However, moldings produced in this manner have only inadequate long-term insulation properties, due to the gas exchange processes. In addition, the resistance to mechanical loads is only low, examples are loads that can be raised in contact with pointed articles or with sharp edges.

Description of the invention The objective of the present invention was to provide composite elements which can be used for refrigeration equipment and which optionally allow the incorporation of VIPs. They are proposed for being easy to produce, and for having good mechanical resistance and low intrinsic weight. An additional intention is that it is possible to apply decorative layers.

Surprisingly, the objective was achieved through the content of the invention, particularly an elementary compound comprising; a) a core made of a foam or a porous material, b) an outer layer applied to the core a), and, "c) a sheet made of a thermoplastic and which differs from the outer layer b).

The invention also provides for the production of the composite elements, and also the use thereof, 'in particular to produce refrigeration equipment.

The core a) is preferably one selected from the group comprising foams and porous materials.

The foams a) are preferably selected from the group comprising melanin-formaldehyde foams, rigid open cell polyurethane foams, and rigid closed cell polyurethane foams.

The porous materials are preferably inorganic organic or inorganic polymers, hereinafter also referred to as monoliths. Among the monoliths, it is; gives particular preference to aerogels. Aerogels are gels which have pores and have dried under supercritical conditions. |, N In a preferred embodiment of the invention, the core; it is a foam, in particular a rigid foam. The foams are foams of open cells or closed cells, and this varies with the application sector of the composite elements. The open cell foams may be melanin-formaldehyde foams or rigid polyurethane foams, preferably rigid polyurethane foams, and in particular rigid open cell polyurethane foams.

For the purposes of the invention, the rigid foams are foams of DIN 7726 (05/1982), where these are exhi: ben relatively high resistance to deformation under 'compressive load (compressive stress at a compression of '10%', " "; compressive strength of DIN 53421, 06/1984, > 80 kPa).

The rigid polyurethane foams used as the core a) are known. Open cell foams, which can be evacuated, have also been described extensively, for example in EP 2072548. The foams can be used as core a) without further pretreatment. WO 2006/120183 says that the foam can be compressed to improve the ease of evacuation.

Melamine-formaldehyde foams are likewise known, for example from EP 74593. Products of this type are marketed by way of example by BASF SE as Basotect®.

Aerogels which can be used as core a): are described by way of example in WO 2007/065847.

The outer layer b) is preferably selected from the group comprising barrier layers with respect to the gases, also called diffusion barriers, where also "water vapor is considered as a gas, flame retardant layers, with mechanical support.

The diffusion barriers preferably involve waterproof sheets to water vapor and other gases.

Flame retardant barriers preferably involve thin-film mats made of mineral wool, layers; of alkali metal silicate, as described by way of example in WO 2006/040097, or layers made of other Flame retardants, such as phosphorus, graphite, melanin, or antimony trioxide.

The mechanical support coatings preferably involve single layer or multiple layer systems made of cardboard, plastic, or sheet metal, and these have also optionally been reinforced by a honeycomb structure located beneath them.

It is particularly preferable that, as described, the diffusion barriers used as the layer b) extér'ria involve sheets.

The outer layer b), in the simplest case, may involve a metal layer, preference being given here to sheets made of aluminum. The outer layer b) is preferably a composite sheet.

It is particularly preferable that the outer layer b) involves a multilayer composite sheet with one. ¾Rane of metal applied by metallization or by rolling ,: It is particularly preferable that the outer layer of metal "a" used as the outer layer b) be composed of aluminum. According to this, the external layer b) is in particular an aluminum foil or an aluminum composite foil.

The sheet used as the external layer b) is in particular composed of polyester, polyvinyl chloride, polyolefins, such as polyethylene or polyethylene. polypropylene, or polyvinyl alcohol.

In the field of vacuum insulation panels, for the subsequent sealing process, preference is given to the b) composite sheets of aluminum, composed of an aluminum layer with a thickness of approximately 6 micrometers and a layer of polyethylene, or metallized high barrier laminates composed of metallized polyethylene laminates with Al or metallized polyethylene terephthalate laminates with Al, where the thickness of the Al layer here is only 30 to 100 nm. The metallized high barrier laminates are composed of at least two layers of Al in order to inhibit the entry of small molecules, for example water, as the diffusion trajectories extend. However, in the case of applications of thermal insulation of composite elements, the thickness of the metal layer should certainly not exceed a number of micrometers, otherwise heat loss through thermal bridging will occur. , and in particular through its dissipation in the corners, 'becomes excessive. ....

In a preferred embodiment of the invention, the outer layer: b ') is a sheet which completely encloses the: num: e'; or a). It is particularly preferable that the external layer b), which is described, is a sheet impervious to gas. In this embodiment of the invention, the core a) was preferable: it has been evacuated. | ·;; · In this embodiment, it is preferable that the aforementioned open cell foams are used as core a), examples are melanin-formaldehyde foams and rigid open cell polyurethane foams. Core a) has been completely wrapped with outer layer b) and sealed to make it gas-tight.

As stated above, the sheet c) is composed of a thermoplastic. This preferably is selected from the group comprising polyvinyl chloride, copolymers of styrene, polypropylene, polyvinylidene fluoride, thermoplastic polyurethane (TPU), and polymethyl methacrylate (PM A), and blends made of thermoplastic polyurethane and styrene copolymers.

Sheets of this type are known and described by way of example in WO 2004/098878.

The thickness of the sheets c) used is preferably 50 to 750 m, preferably 100 to 500 μp ?, and particularly preferably 200 to 350 μ? T. They can be produced from the corresponding starting materials in the form of pellets, by means of the known processes of sheet production. The blown sheets or "cast sheets" may be involved here, and for the production of cast sheets the extrusion process is preferred here :.

In order to improve the adhesive properties, the sheets may have to undergo Corona treatment in one or another from both sides.

WO 2008/135550 describes the specific embodiment of the sheet c). This is composed of mixtures comprising thermoplastic polyurethane (TPU) and an acrylonitrile-styrene-acrylate copolymer (ASA).

Said mixtures (1) comprise from 1% by weight to 40% by weight, preferably from 3% by weight to 30% by weight, in particular preferably from 5% by weight to 25% by weight, of (A) thermoplastic polyurethane , in particular on the basis of aliphatic isocyanate, and from 60% by weight to 99% by weight, preferably from 70% by weight to 97% by weight, in particular preferably from 75% by weight to 95% by weight, of ( B) acrylonitrile-styrene-acrylate copolymer (ASA),.?, /? ethylene-styrene acrylonitrile-homo- or copolymer material (AES), preferably acrylonitrile-styrene-acrylate copolymer (ASA), in each case based on the total weight of the mixture (1), preferably based on the total of the pás'os of (A) and (B) in the mixture (1).

The ASA (B) preferably is based on: (Bl) from 10 to 90% by weight of at least one graft: rubber-based (Bll) from 50 to 95% by weight of a base graft produced using (Bill) from 70 to 99.9% by weight of at least one acriiatf'o: of alkyl (B112) from 0.1 to 30% by weight of at least one crosslinking agent at least bifunctional, (B113) from 0 to 29.9% by weight of at least one other copolymerizable monomer, (B12) from 5 to 50% by weight of an envelope graft based on (B121) from 65 to 90% by weight, preferably from 70 to 80% by weight, of at least one vinylaromatic monomer, (B122) from 10 to 35% by weight, preferably from 20 to 30% by weight, of at least one unsaturated, copolymerizable, polar monomer, preferably acrylonitrile and / or methacrylonitrile, (B123) from 0 to 25% by weight of at least one other copolymerizable comonomer,,. ': (B2) from 10 to 90% by weight of at least one copolymer produced with the components (B21) from 60 to 85% by weight of at least one vinylaromatic monomer, (B22) from 15 to 40% by weight of at least one unsaturated, copolymerizable, polar monomer, and · | (B23) from 0 to 9% by weight of at least one comonomer ^ where the weight data in relation to (Bl) and (B2) will be based on the weight of (B), the weight data in relation to ( Bll? ß12.}. Are based on the weight of (Bl), the weight data in relation, to (Bill), (B112), and (B113) are based on the weight of the component (Bll), (B121) ), (B122), and (B123) are based on the weight of (B12), and the weight data of (B21), (B22), and (B23) are based on the weight of (B2).

The AES materials are composed of a matrix made of polystyrene and acrylonitrile and optionally other monomers. With respect to the above data related to the preferred component B, the AES materials differ from the ASA materials in the Bll component, which in the case of the AES materials can be based on homo- or ethylene copolymers. Examples of copolymers that can be used are alpha-olefins with C3-C20, preferably alpha-olefins with C3-C8. Handbuch der Technischen Polymerchemie [Handbook, of Industrial Polymer Chemistry], VCH Verlag, 1993, in particular page 490, provides a detailed description of production processes for AES plastics, and also a suitable constitution for these materials.

The TPU is preferably an aliphatic TPU, where i the isocyanate used is in particular 1,6-diisocyanate "of hexamethylene (HDI).: Preferably an adhesive is applied between the sheets b) and c) in order to improve the adhesion between the two sheets.

The adhesives used are preferably aqueous systems based on polyurethane, and these can be systems; of a single component or two components.

The one-part adhesives that can be used for the most part are polyurethane dispersions.

These are known and commercially available, and an example that may be mentioned here is Jowapur® 150.50 from Jowat. The two-component adhesives that can be used are mostly combinations of polyurethane dispersions, for example Jowapur® 150.30, with isocyanates, such as Jowat® 195.40 from Jowat. However, acrylate-based or epoxy resin adhesives are also suitable for use herein.

The adhesive can be applied by conventional methods, such as applicator with spreader, roller application, or sprayer application, particular preference is given here to the application process with sprinkler. A drying time of 20 minutes at room temperature, after application of the adhesive is sufficient for the systems described.

It is also possible that the location of the adhesive is, in one of the sheets b) and e), preferably in the sheet, c). A two-layer sheet with an adhesion promoter based on elastomeric styrene-butadiene block polymers; is particularly suitable, examples of these are described in WO-A 96/23823 and WO-A 97/46608 for the coating: of rigid foams by the process of the invention. When They use the adhesive sheets mentioned generally; it is possible to omit the use of some additional adhesive. "',' It is preferable to use co-extruded two-layer sheets Composed of a backing layer, for example polystyrene, HIPS, ASA, polyamide, polypropylene, polyethylene, or polyester, and of an adhesion promoter layer made of an elastomeric thermoplastic, such as the styrene-butadiene block polymers mentioned.

The dimensions of the general merit composite elements are of DIN A4 format up to a few square meters. The layer thickness of composite elements usually varies from 50 to 2000 rare.

The production of composite elements preferably utilizes the processes described in WO 01/32400.

Said process generally comprises the stages of - provision of a core, - application of layer b), - distribution of the coated core made of foam 1 of a material a) porous in a chamber with at least one sheet 'c) and fixing thereof, with separation between the sheet' c) and the coated core, ". - evacuation of the air from the chamber, .1,; - heating the sheet c) of plastic, and compression of the sheet c) of plastic over;; the core surface a) coated, and - removal of the composite element.

In many cases layer b) can be applied to the core a) in a separate process.

When the sheets are used as the outer layer b), the application of the sheet used as the outer layer b) can also take place immediately before its introduction into the apparatus for the application of the sheet c).

It is also possible to apply the sheets b) and c) in the same apparatus.

If the intention is to evacuate the core a), the evacuation process and the sealing with the external component b) can take place before the application of the sheet c).

A process of this type could comprise the steps a) provision of a core made of foam or porous material a), bl) use of a sheet b) to wrap the core, c) evacuation of the core a) and hermetic sealing of: the sheet b), di) arranging the core a) coated in a chamber with at least one sheet c) and fixing it, with separation between the sheet c) and the coated core, el) air evacuation from the chamber, fl) heating the plastic sheet c), and gl) compression of the plastic sheet c) on: the surface of the core a) coated, hl) removal of the composite element.

In another embodiment of the process of the invention / 'the core evacuation process can take place in the apparatus for the application of the sheet c).

A process of this type could comprise the steps of: A) provision of a core made of foam or a) porous material, B) use of a sheet b) to wrap the core, C) distribution of the core a) coated in a chamber with at least one sheet c) and fixation thereof, with separation between the sheet c) and the coated core, »| D) evacuation of the air from the chamber, E) hermetic sealing of the sheet b), F) heating the plastic sheet c), and G) compression of the sheet c) of plastic on,, the core surface a) coated, "" ' H) removal of the composite element.

This embodiment of the process of the invention is simpler than the separate application of component b) to core a) and takes less time. '";: Between stages d) and e) it is preferable to apply; an adhesive to the coated core and / or the sheet c). ,: It is preferable that, in step f), the sheet c) is heated beyond the softening point. ' It is preferable that steps b) and c) are carried out in the same apparatus.

For the process of the invention of the bilateral coating of the core a) with a plastic sheet is essential what - the molding is distributed and secured in a capsule between the sheets, with separation, - the air is evacuated from the capsule, and - the sheets are thus compressed on the opposite areas of the molding, while maintaining a vacuum between the sheets. This reduces the risk of surface defects, such as folds or misalignments.

The sheets c) can be applied on one side of the composite element. It is preferable that a sheet c) is applied on two opposite sides of the molding. The sheet c) here can be left at the edge of the molding, and in another embodiment of the invention the sheet c) may have to be bent over the molding edge. The sheet c) can also completely surround the molding.

The composite elements of the invention are versatile. By way of example, they can be used in the construction industry, for example in the thermal insulation of buildings. Plate c) here serves not only: for decorative purposes but also to protect the core a) from the effects of weathering.

The desired properties of the composite element can be achieved when desired, for example in relation to the flame retardation, by virtue of the different outer layers b).

The moldings of the invention can be used with particular advantage in the production of refrigeration equipment. The composite elements can be produced in the form of the walls and doors of the refrigeration equipment. Said components can then be assembled to give the finished cooling equipment, thereby considerably simplifying the production of the refrigeration equipment. Here again, the color and decorative effect of the cooling equipment can be varied through the sheet c). The protection of the surface can also be achieved.

The use of evacuated composite elements can further reduce the thermal conductivity of the refrigeration equipment.

Claims

CLAIMS 1. - A process for producing composite elements comprising a) a core made of a foam or a porous material; b) an outer layer applied to core a), and; c) a sheet c) made of a thermoplastic and that differs from the outer layer b), characterized in that it comprises the following steps: - distribution of the core a) coated with the outer layer b) in a chamber with at least one sheet c), with separation between the sheet c) and the core a) coated and the fixing thereof, - evacuation of the air from the chamber, - heating the plastic sheet c),. , compression of the sheet c) of plastic on the surface of the core a) coated, and - removal of the composite element. | 2. - The process according to claim 1, characterized in that the core a) is a foam selected from the group comprising melanin-formaldehyde foams, rigid open cell polyurethane foams, ... and closed cell polyurethane foams. rigid. , n " 3. - The process according to claim 1, characterized in that the core a) is an airgel. | «|'| '< . - The process according to any of claims 1 to 3, characterized in that layer b) External is selected from the group comprising barrier layers with respect to gases, flame retardant layers, and mechanical support layers. 5. - The process according to any of claims 1 to 4, characterized in that the outer layer b) is a sheet of metal or a sheet of composite metal. 6. - The process according to any of claims 1 to 5, characterized in that the external layer b) is a multilayer composite sheet with a layer of metal applied by metallization or by lamination. 7. - The process according to any of, claims 1 to 6, characterized in that the outer layer, b) is composed of aluminum. 8. - The process according to any of claims 1 to 7, characterized in that the layer; b) external is a sheet which completely encloses [the kernel a), and where the core a) has been evacuated. 9. - The process according to any of claims 1 to 8, characterized in that the sheet 'c) has been applied only on two opposite sides of the. compound element. | 10. - The process according to any of claims 1 to 9, characterized by applying a adhesive between outer layer b) and the sheet c). 11. - The process according to any of claims 1 to 10, characterized in that the material for the sheet c) has been selected from the group comprising polyvinyl chloride, styrene copolymers, polypropylene, polyvinylidene fluoride, thermoplastic polyurethane (TPU), and polymethyl methacrylate (PMMA), and blends made of thermoplastic polyurethane and styrene copolymers. · · 12. - A process for producing composite elements, according to any of claims 1 to 11, characterized in that it comprises the following steps: al) provision of a core made of foam or a) porous material, bl) use of a sheet b) to wrap the core, the) evacuation of the core a) and hermetic sealing of the sheet b), d) arranging the core a) coated in a chamber with at least one sheet c) and fixing them, with separation between the sheet c) and the coated core,; ·: The) evacuation of the air from the chamber, fl) heating the sheet c) of plastic, .and | 'gl) compressing the sheet c) of plastic' on the surface of the core a) coated, hl) removal of the composite element. 13. - The process according to claim 12, between steps di and el), an adhesive is applied to the coated core and / or the sheet c). 14. - The process according to any of claims 12 or 13, characterized in that steps b) and) are performed in the same apparatus. 15. A composite element obtainable according to one or more of claims 1 to 15. 16. - The use of the composite elements according to claim 15 to produce refrigeration equipment. '