MXPA00010227A - Molding made from polyurethane and process for its production - Google Patents

Abstract

A polyurethane molding is composed of at least two different polyurethane materials, namely of a polyurethane gel and a polyurethane foam. The foam and the gel are arranged in layers one above another so that both materials act together as spring or damping element with respect to a load in the transverse direction. These moldings may preferably be used as seat cushions.

Description

MOLDED POLYURETHANE BODY AND PROCEDURE FOR ITS MANUFACTURE DESCRIPTION OF THE INVENTION The invention relates to a molding body made of polyurethane especially, a seat cushion and a method for its manufacture. The method for manufacturing the molded molding body includes several alternatives in the context of a molding process. The polyurethanes are used in different morphologies that increasingly find their field of application, the application of the polyurethane foam material is known for example, for parts of premium furniture, seats, especially car seats and for seat cushions. This material, when used in the field of seats, is used as a molded or cut part of blocks. In the field of automobiles for example, currently more than 80% of all vehicles are equipped with seat cushions made of polyurethane foamed material. The behavior for the comfort of these seat cushions, is considered negative. Likewise, polyurethane gels are produced for application as seat cushions. Patent EP 57838 claims gels to avoid Ref: 123408 decubitos, which by a low characteristic number, this is by a so-called infra-crosslinking are characterized. They are manufactured by surrounding a polyisocyanate with long chain polyols, which must be free of short chain fractions. These stable shaped gels made of polyurethane starting materials can be used as mattresses, mattress attachments, car seats and cushioned furniture. Patent EP 511 570 claims improved gels 10 made of polyols and polyisocyanates with a lower number which are made of mixtures of long chain and short chain polyethers. As possible applications are indicated among other cushions in shoes, bicycle seats and surfaces of 15 seats, coatings to prevent and prevent displacement, face masks and rounded linings under chairs for horses. The great weight as well as the high thermal capacity of the pure gel seat cushions present a disadvantage, the high thermal capacity can lead to a cold seat feeling, since the body heat is removed for the heating of a cushion complete made of gel. The present invention proposes the task of removing the disadvantages mentioned in the state of the lft - SSM? ------------------------- technique and especially the properties of springing and damping of the molded part - attached to the loading device with a comfort of nice seat. To solve this task, the invention proposes a molded body made of polyurethane which at least consists of two different polyurethane materials, properly at least one gel-polyurethane, and at least one polyurethane foam, which are arranged at least two different spatial zones of the molded body, where the materials are joined by the implicit adhesion properties during the manufacture of the urethane. The molded body can be manufactured in a mold casting process in a conventional mold, as it is also used in the manufacture of the foam material. The composite material in the molded body according to the invention optimally combines the spring and damping properties of the individual materials, so that there is a remarkable advance in terms of the comfort of the seat, different materials are possible and also the placement in several layers of the different materials, also different arrangements by zones, where for example a material is only arranged in the area of the seat reflection, whereby the desired properties can be selected and chosen advantageously.

In particular, the molding body preferably includes an outer covering layer which is especially impenetrable for the polyurethane gel. The cover layer may consist of a sheet, especially of a polyurethane sheet or film, of a polyvinyl chloride or leather sheet or of a textile material, such as a microfiber material, basically different sheeting materials can be used as sheet material. In a preferred embodiment of the invention, the foamed polyurethane material and the polyurethane gel are arranged in at least two layers, one on top of the other so that the foamed material and the gel act covered one by the other together as a spring or damping element against a letter of the transverse direction. In the individual embodiment, a gel layer can at least partially be surrounded by the foamed material or a block of foamed material at least partially enclosed by the gel. In another embodiment of the invention, the molding body is constructed as a seat cushion, wherein preferably, at least on the side of the seat level, there is additionally a textile covering layer. This is especially true when a sheet is used in the rear foam. In this case, the cushion is usually removed later. If, in this embodiment of the invention, external textiles are used, they must, on the gel side, be sealed in a vacuum-tight manner. The use of a textile cover material, directly as a cover layer, is therefore not possible with simple and coarse textiles, since the penetration of the gel material still fluid into the textile should be prevented. For the back placement of a textile cover material, for example thermoplastic polyurethane sheets or films or polyurethane foam cut and closed in cells can be used for example. Polyols and customary polyisocyanates are reacted with one another to produce the polyurethane foam material. The processing technique and typical raw materials are presented, for example, in the book "Poiyurethane Handbook" edited by G. Oertel. In the manufacture of the gel, raw materials can be used as described in the European patents EP 57 838 and EP 511 570. The process according to the invention, for manufacturing a polyurethane molding body is then characterized in that in a process of casting a molding body made of a gel-polyurethane mass and a polyurethane-reaction mixture capable of frothing is produced, where the two masses are joined together by foaming and hardening. In a particularly advantageous manner, the fact that the sandwich construction of two different polyurethanes optimally utilizes the adhesion qualities of this material works in the molding body. The materials are preferably applied by casting onto a cover layer, which is arranged in the molding tool or the cover cap is placed on the finished finished material. If desired, the molding bodies can finally be produced, still treated with another material. In one embodiment, the process can be conducted in such a way that in a mold coated with a cover layer a finished mixture of polyol and polyisocyanate is applied as a gel mass and then a mixture of polyurethane raw material is applied for the preparation of foam on the gel layer and the conditions for foaming and hardening of the masses are maintained in the mold. According to another embodiment of the method, a layer of pre-determined cjel can be applied in the mold preferably covered with a cover layer where a mixture of starting material or polyurethane raw material is subsequently applied for the preparation of the foam material, and then suitable conditions are maintained for the foaming and hardening of the molding body in the usual manner, this is a dwell time determined with a certain temperature profile as well. The pre-determined gel layer can, for example, be placed on the floor of the mold or fixed in the lid of the mold. In another alternative embodiment, a block of prefabricated foamed material can also be placed in the mold where subsequently the mold is filled with a gel mass and the reaction conditions for the manufacture of the polyurethane gel from the mass of the polyurethane are maintained. gel. Preferably, the polyurethane gel is produced from the raw material with an isocyanate functionality and a functionality of the polyol component of at least 5.2, preferably at least 6.5 and still more preferably at least 7.5. In the preferred embodiments, the polyol component for the preparation of the gel consists of a mixture of a) one or more polyols with hydroxyl numbers below 112, b) one or more polyols with hydroxyl numbers in the range of 112 to 600 where the weight ratio of components a) to component b) is between 90:10 and 10:90, the isocyanate characteristic number of the reaction mixture is in the range of 15 to 59.81 and the product of the isocyanate functionality and The functionality of the polyol component is at least 6.15. In another specific embodiment g-5n§ ± st-í --- i-- > -the matter]; Raw materials for the preparation of the gel consist of a) one or more polyisocyanates. b) a polyol component consisting of - one or several polyols (bx) with hydroxyl numbers below 112 and - one or more polyols (b2) with hydroxyl numbers in the range from 112 to 600 and c) optionally a catalyst for the reaction between isocyanate and hydroxyl groups and d) optionally additional materials and / or fillers known per se in polyurethane chemistry, where the proportion by weight of component (bx) to component (b2) is between 90:10 and 10:90, the characteristic isocyanate number of the reaction mixture is in the range of 15 to 59.81 and the product of the isocyanate functionality of the polyol components is at least 6.,fifteen. Preferably, the polyol component consists in the preparation of the gel of one or more polyols with a molecular weight between 1,000 and 12,000 and an OH number between 20 and 112 where the product of the functionalities of the components forming the polyurethane is at least 5.2. and the characteristic isocyanate number is between 15 and 60. As isocyanate it can be used for the manufacture of gel, preferably those of the formula Q (NCO) n where n represents the numbers 2 to 4 and Q represents an aliphatic hydrocarbon radical with 8 to 18 carbon atoms, a cycloaliphatic hydrocarbon radical with 4 to 15 carbon atoms, an aromatic hydrocarbon radical with 8 to 15 carbon atoms. The isocyanates may be in pure form or in the form of the usual isocyanate modifications as modifications of urethane or allophaning or biuretization. In the following, the invention will be described in more detail with reference to exemplary embodiments that should better illustrate the possible embodiments. In one embodiment of the invention a sheet or a textile material is provided which is provided with a vacuum-tight sheet that is drawn deep into a seat mold. The lower side of the mold later represents the seat level of the cushion. Then a freshly prepared mixture of polyol and fluid polyisocyanate is applied. These gel starting materials cover, after filling completely or partially the level of the seat, after this mixture has reacted totally or partially to a polyurethane gel in the next step, a fluid or pre-foamed mixture of starting materials is applied. polyurethane for the production of the mold foam in it. The mixture is foamed, the lid of the mold is closed and after the hardening time that usually reaches 10 minutes the complete seat cushion is removed from the mold. In another embodiment of the invention, the polyurethane gel is produced separately and as a mold-stable gel in one piece, or in sections it is placed in the mold. The gel is placed on the sheet or on the coated textile material. After foaming in the mold, the gel is fixed in defined positions of the level of the seat by means of the foamed polyurethane material. Thus, the gel can be applied exactly looking for "comfort". In this embodiment it is also possible to position a gel cushion on the molding cover. In this way, after foaming is below. Here, the seat feeling in a foamed material is advantageously combined with the pressure distribution properties of the polyurethane gel. In a third embodiment of the invention, a foamed-polyurethane material cut with the gel is applied which is put together by means of the reaction gel. This is done, for example, in such a way that the gel is poured on a very stretched sheet or a vacuum-tight textile material and then on the gel that has not been fully reacted the foam material is put on, during the final reaction the intimate union takes place. of the gel and the foaming material. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (19)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. Molding body made of polyurethane, characterized in that it consists of at least two different polyurethane materials, properly of at least one polyurethane gel and at least one polyurethane foam which are disposed in at least two different spatial zones of the molding body, where the materials are bonded by the implied adhesion properties that occur during the preparation of the urethane. Molding body according to claim 1, characterized in that the molding body includes an outer covering layer that is especially impenetrable for the gel-polyurethane. Molding body according to claims 1 to 6 characterized in that the foamed-polyurethane material and the gel-polyurethane are arranged in at least two layers, one on top of the other. Molding body according to one of claims 1 to 3f, characterized in that a gel layer is at least partially surrounded by a foamed material or a block of foamed material at least partially surrounded by a gel material. Molding body according to one of claims 2 to 4, characterized in that the cover layer consists of a sheet or film, in particular of a polyurethane sheet, of a polyvinyl chloride or leather sheet, or of a textile material especially of a microfiber material. Molding body according to one of claims 5, characterized in that the polyurethane gel consists of raw materials with an isocyanate functionality and a functionality of the polyol component of at least 5.2 preferably of at least 6.5 and more preferably of when 7. The molding body according to claim 1, characterized in that the mold body is a seat cushion. Molding body according to claim 7, characterized in that in the seat cushion, at least one textile covering layer additionally exists on the side by the seat level. 9. Process for the preparation of a molding body made of polyurethane, especially according to one of claims 1 to 8, characterized in that in a casting process a molding body is manufactured from a mass of gel-polyurethane and of a foamable polyurethane reaction mixture where the two masses meet with each other during foaming and hardening. Method according to claim 9, characterized in that the materials are poured onto a cover layer, preferably a sheet or that cover layer is applied to the bonding material. Method according to claim 9 or 10, characterized in that in a mold coated with a cover layer a freshly prepared mixture of polyol and polyisocyanate is placed as a gel mass and then a mixture of raw material-polyurethane for the preparation of the Foamy material is placed on the gel layer and conditions are established for foaming and hardening of the masses in the mold. Method according to claim 9 or 10, characterized in that a layer of prepared gel is applied to the mold, preferably covered with a cover layer, and subsequently a mixture of raw material-polyurethane is applied for the preparation of the foaming material and set the conditions for the foaming and hardening of the molding body. Method according to claim 12, characterized in that the pre-determined gel layer is placed on the floor of the mold or fixed on the lid of the mold. 14. Process according to claim 9 or 10, characterized in that a block of pre-determined foamed material is placed in the mold, the mold has just been filled with a mass of gel and the reaction conditions for the preparation of polyurethane gel from the gel mass. 15. Method according to claim 1 to 14, characterized in that gel masses are produced with the raw material of an isocyanate functionality and a functionality of the polyol component of at least 5.2, preferably 6.5, and especially at least 7.5. 16. Process according to claim 1 to 14, characterized in that the polyol components for the manufacture of the gel are made from a mixture of: a) one or several polyols with hydroxyl numbers below 112, b) one 0 several polyols with hydroxyl numbers in the range of 112 to 600 where the proportion of weight of components a) to component b) is between 90:10 and 10:90, the characteristic number of the isocyanate in the reaction mixture remains in the range from 15 to 59.81 and the product of the functionality of the isocyanate and the functionality of the polyol component is at least 6.15. 17. Procedure according to the. claim 1 to 14, characterized in that the raw materials for the preparation of the gel consist of a) one or more polyisocyanates. b) a polyol component consisting of - one or more polyols (bx) with hydroxyl numbers below 112 and - one or more polyols (b2) with hydroxyl numbers in the range from 112 to 600 and c) optionally a catalyst for the reaction between the isocyanate and hydroxyl groups and d) optionally additional materials and / or fillers known per se in polyurethane chemistry, where the proportion by weight of component (bx) to component (b2) is between 90: 10 and 10:90, the characteristic isocyanate number of the reaction mixture is in the range of 15 to 59.81 and the product of the isocyanate functionality of the polyol components is at least 6.15. 18. Process according to claim 1 to 17, characterized in that the polyol components for the preparation of the gel consist of one or more polyols with a molecular weight between 1000 and 12000 and an OH number between 20 and 112, where the product of the functionalities of the components that make up the polyurethane, at least 5.2, and the characteristic isocyanate number is between 15 and 60. 19. Process according to claim 1 to 18, characterized in that isocyanate for the preparation of the gel is used that of the formula Q (NCO) n in which n represents the number 2 to 4, and Q means an aliphatic hydrocarbon radical with 8 to 18 carbon atoms, a cycloaliphatic hydrocarbon radical with 4 to 15 carbon atoms, aromatic hydrocarbon radical with 6 to 15 carbon atoms or an araliphatic hydrocarbon radical with 8 to 15 carbon atoms, the isocyanates can be applied in pure form or in the usual form of modifications of socianato, such as urethanization, allophanatization or biuretization. * - - -