Polyurethane molded body

Abstract

The present invention relates to a polyurethane (PU) molded body, a method for producing the PU molded body, and a use thereof, wherein the core layer of the PU molded body comprises polyurethane foam.

Description

[0001] 2023PF30175- Abroad

[0002] - 1 -

[0003] POLYURETHANE MOLDED BODY

[0004] The present invention relates to a method for producing polyurethane (PU) molded bodies, so-called PU sandwich components, the PU molded bodies and their use.

[0005] Methods for manufacturing sandwich panels for flat sheet products have been around for a long time. The sandwich structure consists of a lightweight and pressure-resistant core layer with high-strength facing sheets. This structure is bonded by a polyurethane (PU) reaction mixture, which—usually applied to both sides—creates a permanent bond between the core layer, the reinforcing layer (generally comprising reinforcing fibers), and the polyurethane foam using a thermal pressing process. The inner core layer of the sandwich structure preferably consists of cardboard with a honeycomb structure, which serves as a spacer for the PU-coated facing sheets during the pressing process. The sandwich facing sheets are preferably coated by spraying. The substrate carrier is guided by a robot and is held in a horizontal or vertical position by a mixing head during the PU application. The mixing head can also be robot-guided.

[0006] The combination of pressing and forming processes allows for the production of three-dimensionally shaped components. The honeycomb core, which is compressed across its entire surface by a few tenths of a millimeter to achieve a consistent thickness for sheet material, is now pressed in specific areas down to a few percent of its original dimensions. The outer contour of the finished part is formed by pinching the sandwich core with edges in the forming tool, resulting in a component with closed outer edges after removal from the mold. This forming process yields a three-dimensional component with both exposed surfaces and visible edges.

[0007] However, existing polyurethane (PU) molded parts typically consist of a core layer, a reinforcing layer, and a polyurethane foam, which in turn comprises at least three different materials – for example, cardboard, fiberglass, and polyurethane. A reduction in the number of materials would be desirable, for instance, to simplify recycling after the PU molded part has reached the end of its service life.

[0008] Although it has been disclosed in various documents that the core layer in PU molded bodies can also contain polyurethane, for example in DE 2004 030 196 Al or DE 11 2008 000 525 A5, in which a thermoformable polyurethane is disclosed as the core layer, there is no concrete disclosure of how such a PU core layer could be obtained or what its properties would need to be in order to meet the mechanical requirements for these PU molded bodies.

[0009] WO 2007 / 007753 describes a shock absorber consisting of a rigid polyurethane foam and an integrated support layer, wherein the support layer consists of fabric-like, mesh-like or linear 2022PF30175 - Abroad

[0010] - 2 -

[0011] materials such as split-face fabric, mesh or wires can be used, and it prevents the polyurethane foam from breaking into pieces when it is damaged, thus ensuring reliable energy absorption in the event of impact.

[0012] KR 100949783 describes a highly sound-absorbing roof material for vehicles, consisting of a multi-layered carrier layer with semi-rigid polyurethane foam as core material, reinforcing layers on both sides made of fiberglass mats, film layers and non-woven fabric layers, as well as a fabric layer with polyurethane foam layer, whereby the use of air-permeable films instead of waterproof films significantly improves the sound absorption properties of the material.

[0013] The object of the present invention was therefore to provide a PU molded body and a method for its production in which, while maintaining sufficient mechanical stability, the number of materials used can be reduced compared to PU molded bodies. In particular, delamination of the different layers from one another should also be avoided.

[0014] Surprisingly, this task was solved by using a thermosetting polyurethane foam as the core layer.

[0015] The invention therefore relates to a polyurethane molded body consisting of at least 3 to at most 6 layers, wherein the layers comprise a thermosetting polyurethane foam as a core layer, a reinforcing layer and a second polyurethane foam which differs from the thermosetting polyurethane foam.

[0016] Preferably, the core layer has a perforation by at least one hole passing through the core layer, i.e., one or more holes passing through the core layer. Where preferred or mandatory features of the holes are described below, these also apply in the case of a single hole. "Passing through" in the context of this application means that the holes on two opposite sides of the core layer are open to the environment, and the holes may also be at least partially filled with a material that is then in contact with the environment. Before the production of the PU molded body, the holes are preferably unfilled, whereas in the PU molded body according to the invention, they are preferably at least partially filled with the second polyurethane foam, which also forms a layer outside the core layer. 2022PF30175 - Abroad

[0017] - 3 -

[0018] In a further preferred embodiment, the holes each have a diameter of 0.5 to 10.0 mm, preferably 1.0 to 8.0 mm, more preferably 2.0 to 6.0 mm, most preferably 2.5 to 5.5 mm or 3.0 to 5.0 mm, independently of each other.

[0019] In a preferred embodiment, the holes are slot-shaped and arranged such that they form at least two sides of a polygon. Particularly preferably, these holes form a regular or substantially regular polygon, more preferably a regular or substantially regular hexagon. It is also conceivable that a single hole has this shape and arrangement, with several holes being preferred.

[0020] In another preferred embodiment, the core layer and the reinforcing layer are arranged such that the core layer has a side facing the reinforcing layer and the core layer has at least one depression on the side facing the reinforcing layer. For the purposes of this application, a depression is a feature corresponding to a hole, but unlike a hole, it is only open to or connected with the surroundings on one side of the core layer. Where preferred or mandatory features of the depressions are described below, these also apply in the case of a single depression.

[0021] Before the production of the PU molded body, the recesses are preferably unfilled, whereas in the PU molded body according to the invention they are preferably at least partially filled with the second polyurethane foam, which also forms a layer outside the core layer.

[0022] In a preferred embodiment, the recesses are slot-shaped. Particularly preferably, they form a polygon, even more preferably a regular or substantially regular polygon, and most preferably a regular or substantially regular hexagon.

[0023] In a preferred embodiment, the core layer of the PU molded body has a density of at most 120 kg / m³. 3 , preferably no more than 100 kg / m² 3 , for example 15 - 100 kg / m² 3 , especially preferred 30 - 80 kg / m² 3 , most preferred 40 - 70 kg / m² 3 on.

[0024] In another preferred embodiment, the core layer of the PU molded body exhibits low resilience, meaning that its thickness can be reduced by compression and it retains this thickness after the end of the compression process.

[0025] Furthermore, the core layer of the PU molded body is preferably a foam with an open-cell structure of at least 40%, more preferably at least 50%, even more preferably at least 60%, particularly preferably at least 65%, most preferably 2022PF30175 - Abroad

[0026] - 4 - at least 70%. Within the scope of this invention, the open-cell structure can be determined in accordance with DIN EN ISO 4590.

[0027] In a preferred embodiment, the core layer of the PU molded body has a tensile strength of 0.20–2.00 MPa, more preferably 0.25–1.50 MPa, and even more preferably 0.30–1.20 MPa. Within the scope of this invention, the tensile strength can be determined in accordance with DIN 53430.

[0028] In a preferred embodiment, the core layer of the PU molded body has a compressive strength of 0.05–1.00 MPa, more preferably 0.10–0.80 MPa, and even more preferably 0.15–0.60 MPa. Within the scope of this invention, the compressive strength can be determined in accordance with DIN EN 826.

[0029] In a preferred embodiment, the core layer of the PU molded body has an elongation at break of at least 5%, more preferably at least 8%, and even more preferably at least 10%. Within the scope of this invention, the elongation at break can be determined in accordance with DIN 53430.

[0030] In a particularly preferred embodiment, the core layer of the PU molded body exhibits two or more, most preferably all, of the aforementioned physical properties.

[0031] In a particularly preferred embodiment, the core layer or the second PU foam consists of polyurethane or essentially of polyurethane; most preferably, both the core layer and the second PU foam consist of polyurethane or essentially of polyurethane.

[0032] The polyurethane of the core layer and the second polyurethane foam are each independently of each other a polyurethane known in principle from the prior art, obtainable from the reaction of an isocyanate component with a component reactive towards isocyanates.

[0033] In principle, all compounds commonly used in the production of polyurethanes that are reactive towards isocyanates are suitable as components of the isocyanate-reactive component, for example polyether polyols, polyester polyols, polyether ester polyols, polycarbonate polyols or polyether carbonate polyols.

[0034] For example, polyether polyols can be used, which can be produced in a known manner by polyaddition of alkylene oxides to polyfunctional starter substances in the presence of catalysts. For example, the polyether polyols can be produced from a 2022PF30175 -Ausland

[0035] - 5 -

[0036] A starter compound or a mixture of starter compounds with an average of 1.5 to 8.0 active hydrogen atoms and one or more alkylene oxides is prepared. Preferred starter compounds are molecules with 2 to 8, in particular 3 to 8, and especially 3 to 6, hydroxyl groups per molecule, such as triethanolamine, glycerol, trimethylolpropane, pentaerythritol, sorbitol, and sucrose. The starter substances can be used alone or in a mixture, including with difunctional starter substances such as diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,4-butanediol, and 1,6-hexanediol. Preferred alkylene oxides are ethylene oxide, propylene oxide, and butylene oxide. These can be used alone or in a mixture. When used in a mixture, it is possible to react the alkylene oxides statistically, in blocks, or alternately.

[0037] For the purposes of this application, an active hydrogen atom is a hydrogen atom of a functional group that is reactive towards isocyanates, for example a hydrogen atom of an OH, NH, CO2H or SH group.

[0038] Polyester polyols can be obtained, for example, by esterification of phthalic anhydride, terephthalic acid, isophthalic acid, glutaric, succinic, and / or adipic acid with ethylene glycol, diethylene glycol, propylene glycol, butanediol, hexanediol, trimethylolpropane, glycerol, and others.

[0039] Polyester ether polyols can be obtained, for example, by the esterification described for polyester polyols, if the alcohol component is a dihydric or polyhydric polyether polyol, such as one of the polyether polyols described above. Polyether polyols with Mn values ​​of 150 to 2000 g / mol are preferably used for the production of the polyester ether polyols.

[0040] Polycarbonate polyols can be obtained, for example, by reacting phosgene, dimethyl carbonate, diethyl carbonate, or diphenyl carbonate with difunctional alcohols, polyester polyols, or polyether polyols. The polyester polyols or polyether polyols used for this purpose can correspond, for example, to the polyester polyols or polyether polyols described above.

[0041] Polyether carbonate polyols are obtainable, for example, from the reaction of a starter substance, such as can also be used in the production of polyether polyols, with carbon dioxide and an alkylene oxide, preferably ethylene oxide, propylene oxide, butylene oxide, or mixtures of at least two thereof, particularly preferably in the presence of a double metal cyanide catalyst. 2022PF30175 -Abroad

[0042] - 6 -

[0043] In a preferred embodiment, the thermosetting PU foam is available as a core layer from a first polyurethane reaction mixture comprising a polyisocyanate component A comprising at least one polyisocyanate and a polyol component B comprising, in addition to a component Bl reactive towards isocyanates, all components of the first polyurethane reaction mixture except for the polyisocyanates and optionally a physical blowing agent.

[0044] Preferably, B1 has a number-averaged functionality of 1.5–3.5, more preferably 1.9–3.0, and most preferably 2.1–2.8. Within the scope of this application, the functionality of a compound is the nominal functionality resulting from the functionality of the starter or the number-averaged functionality of the starter mixture. For example, a polyether polyol based on a starter mixture consisting of ethylene glycol and glycerol in a 1:1 mol ratio has a functionality of 2.5.

[0045] Preferably, Bl comprises a polyether polyol Bl-1 with a functionality of 1.5–3.5, preferably 1.6–3.2, particularly preferably 1.8–3.0, and a number-averaged molecular weight of 1000–8000 g / mol, the starter of which comprises or consists of at least one bi- or trifunctional alcohol. Particularly preferably, Bl-1 has a number-averaged molecular weight of 2000–6000 g / mol.

[0046] Particularly preferably, Bl-1 comprises the reaction product of a bi- or trifunctional alcohol with a C2-C4 alkylene oxide, particularly preferably with at least two different C2-C4 alkylene oxides, for example ethylene oxide and propylene oxide; or Bl-1 consists of the aforementioned reaction product. Most preferably, the alkylene oxide content of Bl-1 comprises ethylene oxide in an amount of 0.1–50.0 wt.%, particularly 5.0–40.0 wt.%, preferably 10.0–35.0 wt.%, in each case based on the total amount of alkylene oxide in Bl-1. Equally and especially preferably, the alkylene oxide content of Bl-1 comprises propylene oxide in an amount of 50.0 - 99.9 wt.%, in particular 60.0 - 95.0 wt.%, preferably 65.0 - 90.0 wt.%, in each case based on the total amount of alkylene oxide in Bl-1, wherein it is most preferred that the proportions of propylene oxide and ethylene oxide add up to 100 wt.%, based on the total amount of alkylene oxide in Bl-1.Furthermore, Bl-1 particularly preferably comprises ethylene oxide as an end block in its alkylene oxide part.

[0047] Furthermore, particularly preferably, the bifunctional alcohol in Bl-1 comprises, if present, at least one compound selected from water, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, Bis- 2022PF30175 -Abroad

[0048] - 7 -

[0049] (Hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol, and polybutylene glycols), or mixtures of two or more of the aforementioned compounds, with 1,2-propylene glycol being most preferably used. Equally and particularly preferably, if present, the trifunctional alcohol in B 1-1 comprises at least one compound of glycerol, trimethylolpropane, triethanolamine, or mixtures of two or three of the aforementioned compounds.

[0050] Preferably, Bl comprises a polyether polyol Bl-2 with a functionality of 1.5–3.9, preferably 1.9–3.5, particularly preferably 2.2–3.2, and a number-averaged molecular weight of 100–600 g / mol, the starter of which comprises or consists of at least one bi- or trifunctional alcohol. Particularly preferably, Bl-2 has a number-averaged molecular weight of 200–500 g / mol, more preferably 250–450 g / mol. Bl can comprise Bl-1 and Bl-2, or only one of Bl-1 and Bl-2.

[0051] Particularly preferably, Bl-2 comprises the reaction product of a bi- or trifunctional alcohol with a C2-C4 alkylene oxide, particularly preferably with propylene oxide; or Bl-2 consists of the aforementioned reaction product. Most preferably, the alkylene oxide component of Bl-2 comprises propylene oxide in an amount of 50.0–100.0 wt.%, particularly 80.0–100.0 wt.%, preferably 90.0–100.0 wt.%, in each case based on the total amount of alkylene oxide in Bl-2, wherein it is most preferred that only propylene oxide is present as the alkylene oxide in Bl-2.

[0052] Furthermore, particularly preferably, the bifunctional alcohol in Bl-2 comprises, if present, at least one compound selected from water, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol; 1,8-Octanediol, 1,10-Decanediol, 1,12-Dodecanediol, bis-(hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols), or mixtures of two or more of the aforementioned compounds.Equally preferably, if present, the trifunctional alcohol in Bl-2 comprises at least one compound of glycerol, trimethylolpropane, triethanolamine, or mixtures of two or three of the aforementioned compounds; most preferably, Bl-2 comprises a trifunctional alcohol, in particular trimethylolpropane. 2022PF30175 - Foreign.

[0053] - 8 -

[0054] Preferably, Bl comprises a polyether polyol Bl-3, different from Bl-2, with a functionality of 1.5–3.5, preferably 1.6–3.2, particularly preferably 1.8–3.0, and a number-averaged molecular weight of 100–400 g / mol, the starter of which comprises or consists of at least one bi- or trifunctional alcohol. Particularly preferably, Bl-1 has a number-averaged molecular weight of 150–300 g / mol. Bl can comprise Bl-1, Bl-1–B1–B2, and Bl-3, or only one, or any combination of any two of Bl-1, Bl-1–B1–B2, and Bl-3.

[0055] Bl-3 particularly preferably comprises the reaction product of a bi- or trifunctional alcohol with a C2-C4 alkylene oxide, particularly preferably with propylene oxide; or Bl-3 consists of the aforementioned reaction product. Most preferably, the alkylene oxide fraction of Bl-3 comprises propylene oxide in an amount of 50.0–100.0 wt.%, particularly 80.0–100.0 wt.%, preferably 90.0–100.0 wt.%, in each case based on the total amount of alkylene oxide in Bl-3, wherein it is most preferred that only propylene oxide is present as the alkylene oxide in Bl-3.

[0056] Furthermore, the bifunctional alcohol in Bl-3 particularly preferably comprises, if present, at least one compound selected from water, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol; 1,8-Octanediol, 1,10-Decanediol, 1,12-Dodecanediol, bis-(hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols), or mixtures of two or more of the aforementioned compounds, most preferably 1,2-propylene glycol.Equally preferably, if present, the trifunctional alcohol in B 1-3 comprises at least one compound of glycerol, trimethylolpropane, triethanolamine, or mixtures of two or three of the aforementioned compounds.

[0057] Preferably, Bl comprises a polyester ether polyol Bl-4 having a functionality of 1.5–3.5, more preferably 1.6–3.2, more preferably 1.8–3.0, and a number-averaged molecular weight of 100–350 g / mol, which is obtainable, for example, from the reaction of at least one bi- or trifunctional alcohol with at least one bi- or tricarboxylic acid and at least one alkylene oxide, more preferably from the reaction of a bifunctional alcohol with a bifunctional acid and a C2–C4 alkylene oxide, or Bl-4 consists thereof. Particularly preferably, Bl-4 has a number-averaged molecular weight of 100–350 g / mol, more preferably 150–300 g / mol. Bl can comprise Bl-1, Bl-1–B2, Bl-3, and Bl-4, or only one, or any combination of two or three of Bl-1, Bl-2, Bl-3, and Bl-4. Instead of free polycarboxylic acids 2022PF30175 - Abroad

[0058] - 9 - the respective polycarboxylic acid anhydrides or polycarboxylic acid esters of lower alcohols can be used in the production of polyester ether polyols.

[0059] Particularly preferably, Bl-4 comprises the reaction product of a bifunctional alcohol with a bicarboxylic acid and propylene oxide; or Bl-4 consists of the aforementioned reaction product. Most preferably, the proportion of propylene oxide in the total alkylene oxide used to produce Bl-4 comprises 50.0–100.0 wt.%, in particular 80.0–100.0 wt.%, preferably 90.0–100.0 wt.%, in each case based on the total amount of alkylene oxide used to produce Bl-4, with the most preferred state being that only propylene oxide is used as the alkylene oxide. It is clear to those skilled in the art that this refers to the epoxide used, but that, for example, diethylene glycol or similar compounds, if used as the bifunctional alcohol, are not included in the amount of alkylene oxide used to produce Bl-4.

[0060] Furthermore, particularly preferably, the bifunctional alcohol in Bl-4 comprises, if present, at least one compound selected from water, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol; 1,8-Octanediol, 1,10-Decanediol, 1,12-Dodecanediol, bis-(hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols), or mixtures of two or more of the aforementioned compounds, most preferably 1,2-propylene glycol.Equally preferably, if present, the trifunctional alcohol in B 1-4 comprises at least one compound of glycerol, trimethylolpropane, triethanolamine, or mixtures of two or three of the aforementioned compounds. Equally preferably, the bi- or tricarboxylic acid comprises phthalic anhydride, terephthalic acid, isophthalic acid, glutaric acid, succinic acid, and / or adipic acid.

[0061] In a preferred embodiment, the polyol component B comprises B1-1, B1-2, B1-3, and Bl-4, particularly preferably B1-1, Bl-2, and Bl-3 each independently in an amount of 15.0–50.0 wt.%, and Bl-4 in an amount of 2.0–10.0 wt.%, each based on the total amount of polyol component B. Even more preferably, the proportions of Bl-1, Bl-2, and Bl-3 each independently are 18.0–45.0 wt.%, and most preferably, each independently, 20.0–40.0 wt.% or 23.0–35.0 wt.%, and the proportion of Bl-4 is 2.5–8.0 wt.% or 3.0–7.0 wt.%. Most preferably, the isocyanate-reactive component Bl consists of the aforementioned proportions of Bl-1, Bl-2, Bl-3, and Bl-4. 2022PF30175 - Abroad

[0062] - 10 -

[0063] In a preferred embodiment, the second polyurethane foam is obtainable from a second polyurethane reaction mixture comprising a polyisocyanate component A' comprising at least one polyisocyanate and a polyol component B' comprising, in addition to a component B1' reactive towards isocyanates, all the components of the second polyurethane reaction mixture except for the polyisocyanates and optionally a physical blowing agent.

[0064] Preferably, the isocyanate-reactive component B1' comprises at least one component with at least two reactive hydrogen atoms Bl-1'. In principle, any isocyanate-reactive component suitable for use in the production of polyurethanes is acceptable, such as polyols or amines, in particular polyether polyols, polyester polyols, polycarbonate polyols, polyether ester polyols, or polyether carbonate polyols. Polyether polyols are particularly preferred. These suitable polyols are known to those skilled in the art.

[0065] Suitable polyether polyols for B1' include addition products of the reaction of styrene oxide, ethylene oxide, propylene oxide, butylene oxide and / or epichlorohydrin with di- or polyfunctional starter compounds, such as alcohols, amines, thiols or mixtures thereof. Preferred starting compounds include carbohydrates such as sorbitol or sucrose, mixtures thereof or mixtures of carbohydrates, in particular sorbitol or sucrose, and low molecular weight alcohols such as ethylene glycol, diethylene glycol or propylene glycol.

[0066] Suitable polyester polyols include polycondensates of di-, tri-, or tetrafunctional alcohols with di-, tri-, or tetrabasic carboxylic acids or hydroxycarboxylic acids. Instead of free polycarboxylic acids, the respective polycarboxylic anhydrides or polycarboxylic esters of lower alcohols can be used in the preparation of polyester polyols.

[0067] Suitable polyether ester polyols are compounds containing ether groups, ester groups, and OH groups. Organic dicarboxylic acids with up to 12 carbon atoms, or their derivatives, are suitable for the synthesis of these polyether ester polyols. Polyether polyols obtained by alkoxylation of starter molecules, such as polyhydric alcohols, are also used as components for the synthesis of these polyether ester polyols. The starter molecules are at least difunctional, but may optionally also contain portions of higher-functional, particularly trifunctional, starter molecules. Polyether ester polyols can also be produced by alkoxylation of reaction products obtained from the reaction of organic dicarboxylic acids and their derivatives and components with reactive hydrogen atoms.

[0068] Polycarbonate polyols that can be used are polycarbonates containing hydroxyl groups, e.g., polycarbonate diols. These can be obtained by implementing 2022PF30175 - Abroad.

[0069] - 11 -

[0070] Carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols, or by copolymerization of alkylene oxides, such as propylene oxide, with CO2.

[0071] Instead of or in addition to pure polycarbonate diols, polyether carbonate polyols can also be used, which can be obtained, for example, by copolymerization of a starter compound, such as a polyol or amine as are also used for polyether polyol synthesis, with alkylene oxides and CO2.

[0072] In one embodiment of the invention, the isocyanate-reactive component B 1' comprises a polyether polyol B 1-1' having an OH number of 700–1000 mg KOH / g and a functionality of 2.0–4.0, obtainable by reacting an alkylene oxide with an alcohol. Preferably, B 1-1' is a polyether polyol obtainable by propoxylation of trimethylolpropane, particularly preferably having an OH number of 800–900 mg KOH / g and a functionality of 2.5.

[0073] - 3.5. B1' preferably comprises Bl-1' in an amount of 5.0 - 40.0 wt.%, more preferably 10.0 - 35.0 wt.%, and even more preferably 15.0 - 30.0 wt.%, based on the amount of the polyol component B'.

[0074] In one embodiment, B1' comprises a polyether polyol Bl-2' having an OH number of 300–600 mg KOH / g and a functionality of 3.0–6.0, obtainable by reacting an alkylene oxide with a starting compound, wherein the starting compound is selected from a carbohydrate, a bifunctional alcohol that is not a carbohydrate, or a mixture of the foregoing. Preferably, Bl-2' is a polyether polyol obtained by propoxylation of a mixture of sucrose, propylene glycol, and ethylene glycol, particularly preferably having an OH number of 400–500 mg KOH / g and a functionality of 4.0–5.0. B1' preferably comprises Bl-2' in an amount of 20.0 - 80.0 wt.%, more preferably 25.0 - 70.0 wt.%, and even more preferably 30.0 - 65.0 wt.%, based on the amount of the polyol component B'.

[0075] In one embodiment, B1' comprises a polyether polyol Bl-3', different from Bl-2', having an OH number of 250–550 mg KOH / g and a functionality of 2.0–4.0, obtainable by reacting an alkylene oxide with an alcohol. Preferably, Bl-3' is a polyether polyol obtainable by propoxylation of glycerol, particularly preferably having an OH number of 350–450 mg KOH / g and a functionality of 2.5–3.5. B1' preferably comprises Bl-3' in an amount of 2.0–25.0 wt.%, more preferably 5.0–20.0 wt.%, and even more preferably 5.0 wt.%.

[0076] - 15.0 wt.%.

[0077] B1' can also include Bl-1' and Bl-2'; or Bl-1' and Bl-3'; or Bl-2' and Bl-3'.

[0078] In a preferred embodiment, B1' comprises both Bl-1' and Bl-2' and Bl-3', particularly preferably Bl-1' in an amount of 5.0 - 40.0 wt.%, more preferably 10.0 - 35.0 wt.%. 2022PF30175 - Abroad

[0079] - 12 -

[0080] Bl-2' is particularly preferably present in an amount of 20.0–80.0 wt.%, more preferably 25.0–70.0 wt.%, and more preferably 30.0–65.0 wt.%. Bl-3' can be present in an amount of 2.0–25.0 wt.%, preferably 5.0–20.0 wt.%, and more preferably 5.0–15.0 wt.%, where all quantities refer to the amount of the polyol component B'.

[0081] B1' may further comprise low molecular weight isocyanate-reactive components Bl-4', such as di- or trifunctional amines or alcohols with a molecular weight of less than 400 g / mol, for example mono- or diethylene glycol, glycerol, ethylenediamine or any combination of the foregoing.

[0082] B1' can comprise Bl-4' in an amount of 2.0 - 25.0 wt.%, preferably 5.0 - 20.0 wt.%, more preferably 5.0 - 15.0 wt.%, based on the amount of the polyol component B'.

[0083] Preferably, the polyurethane core layer and the second polyurethane foam are available from polyurethane reaction systems comprising blowing agents. Physical, chemical, or a combination of both blowing agents can be used independently of each other.

[0084] Within the scope of the present invention, physical blowing agents are understood to be compounds that, due to their physical properties, are readily volatile and do not react with the isocyanate component. The physical blowing agents can be selected from the group consisting of hydrocarbons (e.g., n-pentane, isopentane, cyclopentane, butane, isobutane, propane), ethemes (e.g., methylal), halogenated ethemes, perfluorinated and partially fluorinated hydrocarbons with 1 to 8 carbon atoms, etc. B. Perfluorohexane, HFC 245fa (1,1,1,3,3-pentafluoropropane), HFC 365mfc (1,1,1,3,3-pentafluorobutane), HFC 134a or mixtures thereof, as well as (hydro)fluorinated olefins, such as HFO 1233zd(E) (trans-l-chloro-3,3,3-trifluoro-1-propene) or HFO 1336mzz(Z) (cis-l,l,l,4,4,4-hexafluoro-2-butene) or additives such as FA 188 from 3M (l,l,l,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)pent-2-ene), and mixtures thereof.

[0085] In addition to or instead of physical blowing agents, chemical blowing agents can also be used. These are particularly preferably water and / or formic acid. The polyurethane reaction systems from which the polyurethane core layer and the second rigid polyurethane foam are obtained particularly preferably contain or consist of water.

[0086] Suitable polyurethane reaction systems for producing the polyurethane core layer and the second polyurethane rigid foam include an isocyanate component comprising a polyisocyanate. In principle, the usual aliphatic, cycloaliphatic, and araliphatic isocyanates can be used. 2022PF30175 - Abroad

[0087] - 13 -

[0088] Di- and / or polyisocyanates and in particular aromatic isocyanates, which are known from polyurethane chemistry, are used. Examples of such suitable polyisocyanates are ethylene diisocyanate, 1,4-butylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecane diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane 1,3- and 1,4-diisocyanate and mixtures of these isomers, isophorone diisocyanate (IPDI), 2,4- and 2,6-hexahydrotoluene diisocyanate and mixtures of these isomers, 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, bis(4,4'-, 2,4'- and 2,2'-isocyanatocyclohexyl)methane or mixtures of these isomers, and aromatic isocyanates of the general formula R(NCO)z, where R is a polyvalent organic residue containing an aromatic compound, and z is an integer of at least 2 is.Examples include 1,3-diisocyanato-o-xylene, 1,3-diisocyanato-p-xylene, 1,3-diisocyanato-m-xylene, 2,4-diisocyanato-l-chlorobenzene, 2,4-diisocyanato-l-nitrobenzene, 2,5-diisocyanato-l-nitrobenzene, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate, 2,2'-methylenedi(phenyl isocyanate) (MDI), 2,4'-MDI, 4,4'-MDI, and their higher homologs and mixtures thereof, 1,5-naphthalene diisocyanate, l-methoxy-2,4-phenylene diisocyanate, and 4,4'-biphenylene diisocyanate. 3,3'-Dimethyl-4,4'-diphenylmethane diisocyanate, and 3,3'-Dimethyldiphenylmethane-4,4'-diisocyanate; triisocyanates, such as 4,4',4"-triphenylmethane triisocyanate and 2,4,6-toluene triisocyanate, and tetraisocyanates, such as 4,4'-dimethyl-2,2'-5,5'-diphenylmethane tetraisocyanate, as well as 1,3- and / or 1,4-bis-(2-isocyanato-prop-2-yl)benzene (TMXDI), 1,3-bis-(isocyanatomethyl)benzene (XDI).

[0089] In addition to the aforementioned isocyanates, modified isocyanates, such as those with uretdione, isocyanurate, carbodiimide, uretonimine, allophane, or biuret structures, can also be used, as well as modified isocyanates in the form of prepolymers, obtainable from the reaction of one or more polyisocyanates with one or more polyols. It is possible that the isocyanate is a prepolymer, obtainable by reacting an isocyanate with an NCO functionality of > 2 and polyols with a molecular weight of > 62 g / mol to < 8000 g / mol and OH functionalities of > 1.5 to < 6.

[0090] The isocyanate components of both the core layer and the second polyurethane foam preferably comprise at least one of monomeric MDI, oligomeric MDI, polymeric MDI and mixtures of at least two of the aforementioned.

[0091] The NCO content of the isocyanate components is preferably above 25 wt.%, preferably above 30 wt.%, and particularly preferably above 31.5 wt.%, independently of each other. Their NCO functionality is preferably between 2.1 and 2.9, and their viscosity is preferably < 500 mPas (at 25 °C), measured according to DIN 53019-1. 2022PF30175 - Abroad

[0092] - 14 -

[0093] In addition to the isocyanate component and the component reactive towards isocyanates, as well as the preferred blowing agent, the PU reaction mixtures can also independently contain other substances commonly used in polyurethane chemistry, for example catalysts, foam stabilizers, colorants, inorganic fillers, emulsifiers, cell openers, flame retardants, reaction retarders, stabilizers against aging and weathering, lubricants and release agents (also called "release agents"), dispersing aids, oxidation retarders, plasticizers, inorganic flame retardants, phosphorus- and / or halogen-containing organic flame retardants, fungistatic and bacteriostatic substances, pigments and dyes, as well as the usual organic and inorganic fillers known per se.

[0094] In particular, the second PU reaction mixture may contain internal separating agents such as fatty acids, fatty acid esters or mixtures of fatty acids and fatty acid esters.

[0095] Examples of suitable catalysts are catalytically active metal compounds or amine compounds, for example tin(II) salts of carboxylic acids with 2-24 carbon atoms such as tin(II)-2-ethylhexanoate, tin(II)-2-butyloctoate or tin(II) ricinoleate, as well as organotin(IV) compounds such as dibutyltin(IV) dilaurate or dimethyltin(IV) neodecanoate, non-incorporable amines such as triethylamine, tributylamine, dimethylcyclohexylamine, dimethylbenzylamine, N-methylimidazole, N-methyl-,N-ethyl-,N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutylenediamine, N,N,N',N'-

[0096] Tetramethylhexylenediamine-1,6, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis-(dimethylaminopropyl)-urea, dimethylpiperazine, 1,2-dimethylimidazole, 1-aza-bicyclo-[3,3,0]-octane, l,4-diaza-bicyclo-[2,2,2]-octane and incorporatable amines such as N,N- Dimethylaminopropylamine, bis-(dimethylaminopropyl)amine, N,N-dimethylaminopropyl-N'-methyl-ethanolamine, dimethylaminoethoxyethanol, bis-(dimethylaminopropyl)amino-2-propanol, N,N-dimethylaminopropyldipropanolamine, N,N,N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether, N,N-dimethylaminopropyl urea, N-(2-Hydroxypropyl)-imidazole, N-(2-Hy-droxyethyl)-imidazole, N-(2-AminopropyI)-imidazole, 2-((Dimethylamino)ethyl)methylaminopropanol, l,l'-((3- (Dimethylamino)propyl)imino)bis-2-propanol and / or reaction products of ethyl acetoacetate, polyether polyols and l-(Dimethylamino)-3-aminopropane, and in particular the tallolic acid amide salt of N,N-dimethylaminopropylamine.

[0097] Examples of foam stabilizers include siloxane-polyoxyalkylene copolymers, organopolysiloxanes, ethoxylated fatty alcohols and alkylphenols, fatty acid-based amine oxides and betaines, and castor oil or ricinoleic acid esters. 2022PF30175 - Abroad

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[0099] Preferably, glass fiber mats, glass fiber fleeces, glass fiber tangles, glass fiber woven fabrics, cut or ground glass or mineral fibers, natural fiber mats and knits, cut natural fibers and fiber mats, fleeces and knits based on polymer, carbon or aramid fibers, and mixtures thereof can be used as a reinforcing layer. In a preferred embodiment, the reinforcing layer comprises polyurethane, consists essentially of polyurethane, or consists entirely of polyurethane.

[0100] In a preferred embodiment, the polyurethane molded body does not comprise any internal film layers. For the purposes of this application, an internal layer is understood to be a layer whose two opposing surfaces are at least partially covered by other layers. For the purposes of this application, a film layer is understood to be a layer that can be produced in the manufacturing process of the polyurethane molded body, for example, by lamination or hot melting, as disclosed, for example, in KR 100949783.

[0101] The invention also relates to a method for producing a polyurethane molded body comprising a thermoset polyurethane foam as a core layer, a reinforcing layer, and a second polyurethane foam that differs from the thermoset polyurethane foam, in particular from the polyurethane molded body described above. All preferred features described above for the components of the PU molded body are also considered preferred features for the components used in the method. The method according to the invention comprises the steps: i. Providing a core layer comprising a thermoset polyurethane foam obtainable from a first polyurethane reaction mixture, a reinforcing layer, and a second polyurethane reaction mixture that differs from the first polyurethane reaction mixture; ii. Applying the reinforcing layer to the core layer; iii.iv. Applying the second polyurethane reaction mixture to the reinforcement layer to obtain a semi-finished product, iv. Placing the semi-finished product in a mold, v. Compressing and heating the semi-finished product in the mold so that the second polyurethane reaction mixture hardens to obtain the polyurethane molded body, vi. Demolding the polyurethane molded body, vii. Optionally, post-processing the polyurethane molded body obtained in vi. 2022PF30175 - Abroad.

[0102] - 16 -

[0103] In addition to a core layer consisting of a thermosetting polyurethane foam (PU foam) derived from a first PU reaction mixture and a reinforcing layer, a second polyurethane reaction mixture, different from the first, is provided. The reinforcing layer is applied to the core layer, and the second polyurethane reaction mixture is then applied to this, resulting in a semi-finished product. This semi-finished product is placed in a mold, compressed, and heated. The second polyurethane reaction mixture cures as a result, yielding the PU molded body. This body is then demolded and, if necessary, post-processed.

[0104] In a preferred embodiment, the compression of the semi-finished product in step v. is carried out such that the core layer in the polyurethane molded body has a smaller thickness than before the compression of the semi-finished product, preferably a thickness that is at most 6 mm smaller, more preferably a thickness that is at most 4 mm smaller, particularly preferably a thickness that is at most 3 mm smaller, and most preferably a thickness that is at most 2 mm smaller than before the compression of the semi-finished product.

[0105] Heating in the mold can be carried out, for example, in such a way that the mold has a temperature between 40 and 160 °C.

[0106] The individual components of the polyurethane reaction mixtures are preferably reacted in such quantities that the equivalence ratio (also “index” or “NCO index”) of the sum of the NCO groups of the polyisocyanates to the sum of the hydrogens reactive towards isocyanate groups of the other components is 0.8:1.0 to 1.4:1.0, particularly preferably 0.9:1.0 to 1.3:1.0.

[0107] The semi-finished product produced up to step iii is preferably manufactured by first applying a reinforcing layer, in particular a reinforcing fiber layer, to both sides of the core layer. Then, it is treated with the second polyurethane reaction mixture, in particular a two-component polyurethane mixture, i.e., a mixture of an isocyanate component and a component reactive towards isocyanates (also called a "polyol component"). Simultaneously with this treatment, partially or fully cut fibers can preferably be applied. The bonding of these additionally applied, cut fibers, which are wetted with PU, is ensured.

[0108] When using a reinforcing fiber mat, it is placed on top and impregnated with the second polyurethane reaction mixture in the usual manner. Here too, partially or fully cut fibers can be applied simultaneously. 2022PF30175 -International

[0109] - 17 -

[0110] After removal from the mold ("demolition"), the PU molded bodies according to the invention can be laminated with cover layers or decorative materials in a subsequent step using known methods. When using suitable cover layers or decorative materials, the bonding to the PU molded body can also be achieved during the manufacturing step by first inserting and simultaneously pressing the cover layer or decorative material with the semi-finished product or the reinforcing fiber mat in the mold. Textile fabrics blocked against polyurethane impregnation, compact or foamed plastic films, as well as spray-on or RIM skins made of polyurethane can be used as decorative materials.Suitable surface coatings can also include pre-formed materials suitable for exterior applications, such as metal foils or sheets, as well as compact thermoplastic composites made of PMMA (polymethyl methacrylate), ASA (acrylic ester-modified styrene-acrylonitrile terpolymer), PC (polycarbonate), PA (polyamide), PBT (polybutylene terephthalate), and / or PPO (polyphenylene oxide) in painted, paintable, or colored form. Surface coatings produced continuously or discontinuously based on melamine-phenol, phenol-formaldehyde, epoxy, or unsaturated polyester resins can also be used. Materials containing or consisting of polyurethanes, such as thermoplastic polyurethanes, are preferred as surface coatings.These materials have the aforementioned advantage over others that they can be applied to the PU molded body during compression and heating in step v of the inventive process.

[0111] The invention further relates to the PU molded body obtainable according to the inventive method.

[0112] Finally, the invention relates to the use of the PU molded body according to the invention as a structural or cladding component, in particular for the automotive, furniture and construction industries.

[0113] Examples

[0114] Production of PU molded bodies

[0115] On a polyurethane core layer with a thickness of 20 mm and a density of 60 kg / m³ 3 Both sides were covered with randomly oriented glass fiber mats with a basis weight of 450 g / m². 2The sandwich structure was placed in a mold and subjected to a total of 900 g of a polyurethane foam reaction mixture by spraying it at room temperature. This sandwich structure was then placed in a mold which, in some trials, already contained a thermoplastic polyurethane (TPU) film on the underside. Subsequently, the 2022PF30175 was heated to 125 °C.

[0116] - 18 -

[0117] The tool pressed this layer to a wall thickness of 20 mm. After a pressing time of 50 seconds, the tool was opened and the finished PU molded body was removed.

[0118] Mechanical load capacity

[0119] The mechanical strength of PU molded bodies was tested in two different bending tests.

[0120] All tests were conducted in a climate-controlled test chamber at 25 °C and 50% relative humidity. The tests were performed both with and without a TPU top layer, using test plates with a support span of 800 mm. Measurements were taken at five points on each test plate, arranged in a five-point pattern on a cube, with the central measurement point located in the center of the plate and the outer measurement points near the contact surfaces. The round pressure stamp had a diameter of 80 mm. This basic configuration remained unchanged for both test procedures.

[0121] The first attempt to test the basic load-bearing capacity of the test plate under static load was a static bending test in which a maximum force of 1500 N was applied successively to the five measuring points by the pressure stamp at a feed rate of 5 mm per minute.

[0122] The second test, designed to examine a dynamic load situation, was a penetration test. A reduced maximum force of 750 N was applied sequentially to the five measuring points using the pressure ram, with an increased feed rate of 1000 mm per minute.

[0123] Results

[0124] The experiments have shown that the polyurethane molded bodies according to the invention neither break nor show any marks on the component, so that the industrial requirements for an automotive loading floor are met.

Claims

2023PF30175 - Abroad - 19 - Claims 1. Polyurethane molded body consisting of at least 3 and at most 6 layers, wherein the layers comprise a thermosetting polyurethane foam as the core layer, a reinforcing layer and a second polyurethane foam that differs from the thermosetting polyurethane foam.

2. Polyurethane molded body according to claim 1, wherein the core layer has a perforation by one or more holes passing through the core layer.

3. Polyurethane molded body according to specification 2, wherein the hole or holes each independently have a diameter of 0.5 to 10.0 mm, preferably 1.0 to 8.0 mm, more preferably 2.0 to 6.0 mm, most preferably 2.5 to 5.5 mm or 3.0 to 5.0 mm.

4. Polyurethane molded body according to one of claims 2 to 3, wherein the hole or holes are slit-shaped and are arranged such that it or they form at least two sides of a polygon, preferably a regular or substantially regular polygon, more preferably a regular or substantially regular hexagon.

5. Polyurethane molded body according to claim 1, wherein the core layer and the reinforcement layer are arranged such that the core layer has a side facing the reinforcement layer and the core layer has at least one depression on the side facing the reinforcement layer, wherein the depression is preferably slit-shaped and more preferably forms a polygon, even more preferably a regular or substantially regular polygon, most preferably a regular or substantially regular hexagon.

6. Polyurethane molded body according to any one of claims 1 to 5, wherein the core layer has a density of at most 120 kg / m³ 3 , preferably no more than 100 kg / m² 3 , especially preferred 60 - 80 kg / m² 3 exhibits.

7. Polyurethane molded body according to any one of claims 1 to 6, wherein the thermosetting polyurethane foam is available as a core layer from a second polyurethane reaction mixture having an isocyanate number of 80 - 180. 2023PF30175 - Abroad - 20 - 8. Polyurethane molded body according to any one of claims 1 to 7, wherein the thermosetting polyurethane foam has an open cell structure, determinable according to DIN EN ISO 4590, of at least 40%, preferably at least 50%, more preferably at least 60%, particularly preferably at least 65%, most preferably at least 70%.

9. Polyurethane molded body according to any one of claims 1 to 8, wherein the thermosetting polyurethane foam has an elongation at break, determinable according to DIN 53430, of at least 5%, preferably at least 8%, more preferably at least 10%.

10. Polyurethane molded body according to any one of claims 1 to 9, wherein the reinforcement layer comprises polyurethane.

11. Polyurethane molded body according to claims 1-10, wherein the polyurethane molded body does not comprise any internal film layers.

12. Method for producing a polyurethane molded body comprising a thermosetting polyurethane foam as a core layer, a reinforcing layer, and a second polyurethane foam different from the thermosetting polyurethane foam, comprising the steps of: i. providing a core layer comprising a thermosetting polyurethane foam obtainable from a first polyurethane reaction mixture, a reinforcing layer, and a second polyurethane reaction mixture different from the first polyurethane reaction mixture; ii. placing the reinforcing layer on the core layer; iii. applying the second polyurethane reaction mixture to the reinforcing layer to obtain a semi-finished product; iv. placing the semi-finished product in a mold; v. compressing and heating the semi-finished product in the mold so that the second polyurethane reaction mixture cures to obtain the polyurethane molded body; vi.Demolding of the polyurethane molded body, vii. if necessary, post-processing of the polyurethane molded body obtained in vi. 2023PF30175 - Abroad - 21 - 13. A method according to claim 12, wherein the compression of the semi-finished product in step v is carried out such that the core layer in the polyurethane molded body has a smaller thickness than before compression of the semi-finished product.

14. Polyurethane molded body obtainable according to the method of one of claims 12 or 13.

15. Use of the polyurethane molded body according to claim 14 as a structural or cladding component, in particular for the automotive, furniture and construction industries.