WO2001032392A9

WO2001032392A9 - Process for manufacturing multilayered foam articles, and thus produced articles

Info

Publication number: WO2001032392A9
Application number: PCT/US2000/029700
Authority: WO
Inventors: Jose Godoy; Jacques Labourier; Patrice Bocquel
Original assignee: Dow Chemical Co; Jose Godoy; Jacques Labourier; Patrice Bocquel
Priority date: 1999-10-29
Filing date: 2000-10-26
Publication date: 2002-05-16
Also published as: WO2001032392A1; WO2001032392A8

Abstract

A process for preparing multilayered foam articles such as an automotive seat or a sound/thermal insulation panel is disclosed. A mold is arranged so that the bottom surface of the mold is flat or inclined to the horizontal plane. A first liquid formulation designed to produce an elastomer is poured into the mold from a mixing head onto the seating zone of the mold and pouring a second liquid formulation designed to produce a foam is poured into the mold from the same or different mixing head outlet. The second liquid foam formulation is allowed to spread on top of the first liquid formulation, the mold is closed and the materials are allowed to rise and cure in the mold.

Description

PRO_CE_SS FOR MANUFACTURIN_GMULTILAYEREDFOAM ARΗCLES, ANDTHUS PRODUCEDARTICLES

The present invention relates to the preparation of multilayered polyurethane foam articles which have an elastomeric outer surface.

The molded foam portion of a seat, particularly seats for transportation vehicles such as automobiles, is generally composed of two or more foams of different hardness.

Multilayered or multihardness polyurethane foams are defined as layers of foams of different hardness (load bearing) and/or densities. These foams are usually used to make seat cushions or squabs which have high SAG factors (that is, the ratio of hardness at high deflection to hardness at low deflection) and superior comfort, especially regarding H-point retention (seat occupant's vertical position).

Various methods are known for the preparation of 0 multilayered polyurethane foams. Such processes are disclosed, for example, in U.S. Patent 4,190,697, EP Patent Publications 251,659 and 279,324 and WO Publication 98/25748.

In the above-described processes, the resulting molded 5 foam article consists of a soft foamed top layer and a harder inner supportive layer. Due to the fragility of the soft foam, which would be in contact with the user of the foam, the foamed articles are generally covered with a fabric to prevent wear of the soft foam surface. The covering of. the foam with a fabric 0 also requires the extra time and labor cost associated with cutting, sewing and applying the fabric to the foam article. It would therefore be advantageous to produce a polyurethane foam, particularly a foam seat, in which the upper surface is durable and thus avoid the need for a fabric covering and/or to avoid the cost of post-mold cut-and-sew operations. It would also be advantageous for such foamed article to have a durable outer layer, which has visual and textural properties, which are aesthetically pleasing to the consumer.

It is an object of the present invention to produce fabric-free foam articles having at least two regions of different densities. The articles have a bottom foam layer and a top layer of a higher density elastomer.

Another object of the present invention is to provide a method of preparing the multi-layered foam articles. The process comprises pouring into an open mold a first formulation for producing an elastomer and before the elastomer has completely cured, pouring a second formulation for producing a foam into the open mold, closing the mold and after the foam and elastomer have cured, demolding the foamed article. When sufficiently cured, the article is removed from the mold and inverted, up to 180°, for use.

Figure 1 is a top view of an automotive front seat mold.

Figures 2a and 2b are a vertical cross-section, from front to back, of a molded article made in a mold shown in Figure 1.

Figures 3a and 3b are a vertical cross-section, from side to side, of a molded article made in a mold shown in Figure 1. Figure 4 is a molded article having a microcellular elastomeric layer on top of a rigid foam.

Figures 5a and 5b show a molded article having an elastomeric layer on top of a rigid foam where the elastomeric layer shows the imprint of a metallic insert in the mold.

As used herein, the upper or top layer is the portion of the article that a person or object would come in contact when the article is a seat and the person or object is supported by the seat .

The present invention gives a layered foam article with a well-defined common flat boundary between the layers, good vibration properties, and a durable upper layer. Such articles can be used without a fabric covering. The process also allows for fast pouring of liquid foam formulations into a mold to be viable for use on fast moving industrial production lines. As the articles are inverted after molding for use, the mold can have the negative imprint of a design desired of the molded product. Most preferred negative imprints are those which afford to molded seats having some relief on the durable, upper layer .

The process of the present invention is particularly applicable to automobile seat molds, for making seats and back rests such as those which comprise a flat seating area, and for making seating type furniture, such as office chairs. The process can also be used to produce such articles as mats, sport carpet, etc.

The process for pouring the formulations into an open mold can be done using equipment and techniques known in the art. Such processes include pouring the formulations into the open mold at one location, point wise at different points of the area to be covered, strip-wise, in a spiral pattern, etc. In a preferred method, the formulations are poured strip-wise along a line parallel to and near an external wall of the mold. Such processes for pouring liquid formulations are disclosed in Publications EP 251 659 and WO 98/25748, the disclosures of which are incorporated by reference.

Generally, the formulation for the foam is poured into the mold onto the elastomeric layer before the elastomeric layer is completely cured. In another embodiment, particularly when the formulations are added strip-wise, the formulation to produce a foam is poured onto the bottom mold surface at a place which has not been wetted by the first poured formulation. This process produces a laminar flow of the foam formulation on top of the first formulation. Using such a process, the two formulations may be poured simultaneously using multiple mixing heads .

By strip-wise pouring means that a formulation is poured onto the mold at more than one set-spot and allowing the formulation to flow throughout the mold. Thus the formulations can be poured in lines, zigzag patterns, poured at or near the top of an inclined mold and allowed to flow downward over the mold, pouring at multiple spots, etc. The formulations can also be poured onto a flat mold.

The strip-wise pouring of liquid formulations allows for a longer time interval between pouring of the two formulations than with the fixed (one place) pouring, and produces the flow of the second liquid foam formulation on top of the first liquid formulation. Thus the two step pouring regiment can be accommodated on a dual-hardness foaming equipment with only one mixing head.

The two step strip-wise pouring of the liquid formulations, whether from a single outlet or from two outlets, permits longer pouring time for one liquid formulation than the other liquid formulation. This allows control of relative thickness of both layers. The thickness of the elastomeric layer is generally selected to provide an article with a durable layer while maintaining the comfort of the softer lower layer. For producing seats the elastomeric layer is controlled to provide an article having an elastomeric layer of from 0.1 to 30 millimeters, preferably from 1 to 20 millimeters and more preferably from 2 to 10 millimeters thickness.

The process of the present invention can be operated in various mold configurations or varying process conditions. The process can be operated either in a mold having the bottom surface flat to the horizontal plane or in the mold having the bottom surface inclined. The degree of inclination for a particular foamed article can readily be determined by one skilled in the art. The foam formulations may also be poured into a flat mold and subsequently at least one end of the mold raised to form an angle with the horizontal plane. This inclination of the mold bottom surface may be achieved by actually tilting the mold or by employing a mold, which has been manufactured with an inclined bottom surface.

For most conventional automobile seat molds, the incline in the mold running from the back to the front of the seat is sufficient for the purposes of this invention. Generally the angle of incline is from 0.1 to 60 degrees. Preferably, the angle of incline is 2 to 40 degrees. More preferably the angle of incline 4 to 20 degrees and most preferably 5 to 12 degrees.

Low or high pressure, up to 250 bars, single mixing head or multiple mixing heads mounted on a 5-axes robot arm, or on a 2 -axes manipulator is suitably used in the process of the present invention. A single mixing head capable of pouring two different formulations sequentially, or multiple mixing heads with independent manipulators can be used in the process of the present invention. Mixing heads having two or more, up to eight, preferably two to four, additives and polyol blends streams and one, two or more isocyanate streams are suitable for use in the process of the present invention. The speed of mixing heads can be varied during the pouring of different foam formulations or the mixing heads can even be stopped for a short interval of time at some point above the mold to increase pouring time in a particular zone in the mold.

If multiple mixing heads are used, the distance between outlets and their respective positions can be varied depending on the molding conditions.

In one embodiment of the present invention, the liquid formulations are poured simultaneously from at least two mixing heads outlets strip-wise into the seating zone of the mold along different lines whilst the mixing heads move above and across the seating zone of the mold. Alternatively, the mold can move relative to the mixing head outlet (s) during the pouring of the liquid formulations.

In another embodiment of the present invention, the first formulation designed to produce an elastomer is poured strip- wise into the mold along the line parallel to and near to the external wall of the seating zone of the mold and after an interval of from 0.05 to 5 minutes the second liquid formulation designed to produce a foam is poured strip-wise into the mold along the line parallel to but nearer to the external wall of the mold than the line of pouring of the first liquid foam formulation. The time interval between addition of the formulations will varying depending on various factors such as the reactivity of the polyols, amount of catalysts present, reactivity of the polyisocyanate component, etc. and can readily be determined by those skilled in the art. Preferably the time interval will be between 0.05 seconds to 3 minutes. More preferably the time interval will be from 0.05 seconds to 1 minute. Most preferably the time interval will be from 0.05 to 30 seconds.

Still in another embodiment of the present invention, the first formulation is poured from a mixing head outlet strip- wise along a line parallel to and near to the external wall of a mold and then the second liquid formulation is poured from the same or different mixing head outlet strip-wise along the line parallel to but nearer to the external wall of the mold than the line of pouring of the first liquid formulation. The direction of pouring the second formulation can be in the same direction of the first formulation or in the opposite direction to the direction of pouring of the first liquid formulation.

Still in another embodiment the liquid formulations are poured sequentially from at least two mixing heads outlets strip-wise into the seating zone of t e_^ mold along different lines across the seating zone of the mold.

Normally, the mixing heads are kept vertical relative to the horizontal plane while the liquid formulations are being poured into the mold. However, the mixing heads outlets can be tilted (inclined) relative to the vertical plane while the liquid formulations are being poured into the mold.

The speed of movement of the mixing heads outlets above the mold or the speed of movement of the mold relative to the mixing heads can vary between 0.1 and 150, preferably between 0.5 and 30 m/min.

The elastomeric layer can be made using any suitable substrate elastomer such as polyurethane, polyurea, polyurethane/polyurea, polyacrylates , polyisoprene, polychloroprene, nitrile, polybutylene, silicone rubbers, block copolymers such as styrene and butadiene or any combination of the above. In a preferred embodiment, the elastomeric layer is a polyurethane .

In one embodiment of the present invention, the elastomeric layer is a microcellular elastomer. In another embodiment of the present invention the elastomeric layer is a non-cellular elastomer.

The foam formulation is preferably one that will produce a polyurethane foam. Polyurethane foams are well known in the art and comprise the product obtained by mixing a polyfunctional isocyanate with a polyfuncitonal active hydrogen containing (for example, a polyether polyol) in the presence of a blowing agent, and other conventional agents and allowing them to react under standard conditions_, known in the art. A polyfunctional active hydrogen containing compound includes compounds having at least two hydroxyls, primary or secondary, amines, primary, secondary or tertiary, carboxylic acids or thiol groups per molecule . The term polyurethane thus includes foams containing linkages such as polyurethane, polyureas, etc. and mixtures thereof. Compounds having at least two hydroxyl groups per molecule are especially preferred due to their final performance with polyisocyanates . In the process of the present invention, such mixtures are generated in the mixing head and then poured into the mold through the outlet before the mixture has started to rise, that is, while the foam formulation is still in an essentially liquid state.

The process of the present invention can be used with any type of flexible polyurethane foam formulations including ^vhot- cure' and 'cold- cure' formulations.

Preferred polyurethane foam formulations include those producing flexible foam, preferably flexible HR (high resilience) foams. In such a case, two streams are fed to the mixing head; one comprising a formulated polyol, that is, some or all of polyols, polymer polyols, blowing agent, catalysts, silicone surfactants, blowing agents and other additives; the other comprising the polyisocyanate .

Any known polyether polyol, polyester, blends of polyether polyols, copolymer polyols (such as, for example, SAN, PHD, PIPA) , blends of copolymer polyol, blends of polyols with copolymer polyols can be used in the process of the present invention. Generally for producing a flexible foam, polyols having a functionality of 2 to 5, preferably 2 to 4; and a hydroxyl number of 20 to 1,000, preferably 20 to 700 are used. For applications where the second formulation is for producing a rigid foam, the polyols have a functionality of 2 to 8, preferably 3 to 6; and a hydroxyl number of 200 to 1,200, preferably 300 to 800. The present invention is also to multilayered foam articles which contain three or more layers of different hardness and/or density. Such foamed articles are produced by pouring sequentially into the mold foam formulations that produces a softer foam and/or foam of lower density. For example pouring in a first formulation that forms an elastomeric layer, a second formulation that is a viscoelastic foam and a third formulation which produces a flexible foam. Processes for producing multilayered foams with different density or hardness are disclosed, for example, in EP

Publications 251 659; 393 829; 472 574 and 782 969 and U.S. Patents 4,190,697 and 4,726,086.

Such a process comprises (a) pouring from a mixing head outlet, a first liquid formulation designed to produce an elastomer layer into the mold and before the elastomer layer has cured;

(b) pouring from the same or different mixing head outlet, a second formulation designed to produce a foam into the mold and allowing the second liquid formulation to spread on top of the first formulation and before complete curing of the first and second formulations;

(c) pouring from the same or different mixing head outlet, a third formulation designed to produce a foam having a different density and/or hardness than the foam of (b) into the mold and allowing the third liquid foam formulation to spread on top of the second liquid formulation.

For producing a polyurethane elastomer, a relatively high molecular weight base polyol, with a hydroxyl equivalent weight from 300 to 3,000 having a low hydroxyl number is generally used.

When the elastomeric layer is used to cover a rigid or semi-rigid foam, such article would be applicable for applications in sound and/or thermal insulation.

Any known organic polyisocyanate can be used in the process of the present invention. These polyisocyanates include those containing at least about two isocyanate groups per molecule, preferably, those containing an average of from about 2.0 to about 3.0 isocyanate groups per molecule. The polyisocyanates used in the practice of this invention can be aromatic and/or aliphatic polyisocyanates and include the toluene diisocyanates, especially mixtures of the 2,4 and 2,6 isomers such as those containing 65 percent of the 2,4 isomer and 35 percent of the 2,6 isomer (TDI 65/35), and those containing 80 percent of the 2,4 isomer and 20 percent of the 2,6 isomer (TDI 80/20); and polyisocyanate mixtures comprising 2,4 - or 4,4'- methylene diphenylisocyanate (MDI,); hexamethylenediisocyanate (HMDI); polymeric MDI; and isocyanate-terminated prepolymers thereof. Mixtures of two or more polyisocyanates can also be used in the process of the present invention. The polyisocyanates can be used at all known ratios.

The elastomer and foam formulation may also contain a portion of the polyisocyanate and polyol as prepolymer, prepared by the reaction of an excess of polyisocyanate with the polyol to form an isocyanate-terminated prepolymer. The process for making such prepolymers is well known in the art. Any known catalyst used in the preparation of polyurethanes such as, for example, amines and metal salts, alone or in combination, can be used in the process of the present invention. The catalysts are generally used in a quantity of between 0.002 and 10 percent by weight, based on the total quantity of polyol.

In the process of the present invention, for the foam formulation, water is preferably used as the main blowing agent at a level of from 0.5 to 10, preferably from 2 to 6 parts per hundred parts of polyol. Auxiliary blowing agents such as carboxylic acids or organic or inorganic compounds that liberate gas by reaction with polyisocyanate or under effect of heat, and inert gases such as carbon dioxide, can also be used in the process of the present invention. Although not preferred, organic blowing agents may be included in the foam formulation.

In a preferred embodiment for seating applications, the polyol formulation for producing a top elastomeric layer is a formulation that does not contain water but rather it may include an additional organic blowing agent instead.

For a microcellular elastomeric layer, it is preferred that the formulation contains an additional organic blowing agent. Preferably when producing a microcellular elastomeric foam, the blowing agent is an organic blowing agent. Organic blowing agents include aliphatic hydrocarbons having 1-9 carbon atoms and fully and partially halogenated aliphatic hydrocarbons having 1-4 carbon atoms. Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, ethanol, dimethyl ether.

Fully and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons , and chlorofluorocarbons . Examples of fluorocarbons include methyl fluoride, perfluoromethane , ethyl fluoride, 1, 1-difluoroethane, 1,1,1- trifluoroethane (HFC-143a) , 1, 1, 1, 2-tetrafluoro-ethane (HFC- 134a), pentafluoroethane, difluoromethane, perfluoroethane,

2, 2-difluoropropane, 1, 1 , 1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane .

Partially halogenated chlorocarbons and chlorofluorocarbons for use in this invention include methyl chloride, methylene chloride, ethyl chloride, 1,1,1- trichloroehtnae, 1 , 1-dichloro-l-fluoroethane (FCFC-141b) , 1- chloro-1, 1-difluoroethane (HCFC-142b) , 1, l-dichloro-2 , 2 , 2- trifluoroethane (HCHC-123) and 1-chloro-l, 2 , 2 , 2- tetrafluoroethane (HCFC-124) .

Fully halogenated chlorofluorocarbons include trichloromonofluoromethane (CFC-11) dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC-113), 1,1,1- trifluoroethane, pentafluoroethane, dichlorotetrafluoroethane (CFC-114) , chloroheptafluoropropane, and dichlorohexafluoropropane .

Preferably the additional organic blowing agent is a partially halogenated chlorofluorocarbons . Most preferred is 141b as the blowing agent for the elastomeric layer. Mixtures of the additional organic blowing agent and water can also be used. In this case, the ratio of water to organic blowing agent must be such that the finished molded part still has a self-skin, durable top layer.

The process of the present invention can be used in conjunction with other techniques for producing molded foam articles. One such technique is the use of in-mold-coatings . Such a process is known to those skilled in the art and generally involves the lacquering of molded parts prior to introduction of the first formulation. The lacquer forms a bonded thin layer on the surface of the first layer. Such coatings are commercially available, for example, Bomix products available from Ernst Bottler KG, Bomix-Chemie GmbH & Co.

Any crosslinking agent known in the preparation of polyurethanes such as, for example, glycerol, diethanolamine (DEOA) and triethanolamine (TEOA) can be used in the process of the present invention. The crosslinking agent is used in a quantity known to a person skilled in the polyurethane art.

Any type of known foam modifiers, such as those described in U.S. Patent No. 4,686,240 can be used in the process of the present invention. The foam modifiers are used in a quantity known to a person skilled in the polyurethane art.

Other known additives such as, for example, silicone surfactants, pigments, fillers, and plasticizers can also be used in the process of the present invention. The additives are used in a quantity known to a person skilled in the polyurethane art. Temperature of the liquid foam formulations (polyol and polyisocyanate components) can vary between 10 and 80, preferably between 15 and 35°C.

The polyurethane formulations used in the process of the present invention are preferably chosen such that they differ in hardness (load bearing) from each other. It is further preferred that such formulations differ in hardness by virtue of their content of one or more of the following: (a) polyols, (b) polyisocyanates with a functionality greater than two, that is, with more than two isocyanate groups per molecule, (c) active hydrogen containing compound which may be chain extender or crosslinker, and (d) blowing agent.

During pouring operation, molds are kept at a temperature ranging between 20 and 80, preferably between 35 and 75°C.

The molded polyurethane articles are cured at a temperature of between room temperature and 250 degrees Centigrade conveniently for a period of time between 2 and 20 minutes, before demolding.

The following designations, symbols, terms and abbreviations are used in the Examples below:

CP-6001 is a glycerol initiated polyol having a molecular weight of 6,000 available from The Dow Chemical Company under the trademark VORANOL CP 6001.

CP-4610 is a glycerol initiated polyol having a molecular weight of 5000 available from The Dow Chemical Company under the trademark VORANOL CP 4610. CP-4702 is a glycerol initiated polyol having a molecular weight of 5000 available from The Dow Chemical Company under the trademark VORANOL CP 4702.

VORANOL CP 3001 is a polyether triol with a hydroxyl number of 55 available from The Dow Chemical Company.

VORANOL EP 1900 is a high molecular weight reactive diol with a hydroxyl number of 28 available from The Dow Chemical Company.

VORANOL CP 450 is a polyether triol with an average molecular weight of 450 available from The Dow Chemical Company. SPECFLEX NC 632 is a polyol with a hydroxyl number of 32 (mgKOH/g) available from The Dow Chemical Company.

CP-1421 is a polyol available from by The Dow Chemical Company under the trademark VORANOL CP 1421.

Voranol 4053 is a polyol available from The Dow Chemical Company under the trademark VORANOL 4053.

DEOA is diethanolamine.

SD-179 is a formulated polyether polyol sold by The Dow Chemical Company under the trademark VORATEC SD 179.

Dabco 33LV is a 33 percent solution of triethylene diamine in dipropylene glycol sold by Air Products and Chemicals Inc. under the trademark DABCO 33LV.

Niax A-l is a 70 percent bis (2-dimethylaminoethyl) ether solution in DPG sold by OSI Specialties Inc. B-4113 is a silicone surfactant sold by Th. Goldschmidt under the trademark Tegostab B-4113.

B-8708 is a silicone surfactant sold by Th. Goldschmidt under the tradename Tegostab B 8708.

B-8715 is a silicone surfactant sold by Th. Goldschmidt under the trademark Tegostab B 8715.

NS-540 is a low viscosity liquid diphenylmethane diisocyanate (MDI) and an isocyanate content of 32 percent available from The Dow Chemical Company under the trademark SPECFLEX NS 540.

NE-181 is a methylene diphenyl-diisocyanate based prepolymer developed for use in the production of high resilience molded foams with an isocyanate content of 30 percent available from The Dow Chemical Company under the Trademark SPECFLEX NE 181.

NE-112 is a MDI polyisocyanate containing approximately 23 percent polymeric MDI available from The Dow Chemical Company under the trademark SPECFLEX NE 112.

M-340 is a liquid derivative of 4,4' diphenylisocyanatewith an isocyanate content of 26.3 percent sold by The Dow Chemical Company under the trademark ISONATE M 340.

M-229 is a low viscosity liquid polymethylene polypheylisocyanate available from The Dow Chemical Company under the trademark VORANATE M 229.

NC-700 is a reactive high solids copolymer polyol sold by The Dow Chemical Company under the trademark SPECFLEX NC 700. The invention defined above will now be illustrated with reference to the following Examples.

Example 1

Example 1 illustrates the formation of an elastomeric/soft foam multilayered article. A red dye was added to the elastomeric foam for visual purposes to distinguish the elastomeric layer from the soft layer.

The elastomeric formulation, as given below, was poured into a 9 liter aluminum square mold (30x30x10 mm) , followed by addition of the soft mold formulation. After five and one-half minutes, the resulting demolded inverted article had a flat layer of a red colored elastomeric foam (about 20 mm thick) on top and a soft lower foam layer (about 80 mm thick) . The mold temperature was about 55°C.

Elastomeric Formulation

Polyol Component Part bv weight (pbw) Quantity (qraras)

CP-4610 58.9 141.5

NC-700 23.6 56.7

CP-1421 2.0 4.8

Monoethylene Glycol 5.6 13.44

Water 0.24 0.57

Niax A-l 0.18 0.43

Dabco 33LV 0.65 1.56

Forane 141-b 7.0 16.8

Red Pigment 1.8 - 4.32

Isocyanate component

ISONATE M 340 39.18 94

Index 100 Soft Foam Formulation

Polyol Component Part by weight (pbw) Quantity (grams)

CP-6001 97.0 388

Water 2.9 11.6

Niax A-l 0.15 0.60

Dabco 33LV 0.27 1.08

B-4113 0.50 2.0

Isocyanate component

NE-112 48.2 192

Index 100

Example 2

This example illustrates a machine made elastomeric layer on top of a soft foam.

An automotive seat mold shown in Figure 1 comprising a central seating zone defined by rectangular A, A' , R and R' , two side-rolls zones (a, b) , was employed. The mold was made of aluminum and arranged so that the bottom surface was inclined in relation to the horizontal plane. The inside surfaces of the mold were kept at 47°C and were sprayed with Kluber 41-2013 mold release agent sold by Kluber. Two mixing heads were connected to respectively a Krauss Maffei RIMSTAR 40and a Krauss Maffei KK 10 machine. The two mixing heads outlets were mounted on a 5-axes ASEA 90 robot. The mixing heads outlets were used to dispense respectively elastomeric and soft liquid foam formulations. The composition of the formulations was as follows : Elastomeric Formulation

Polvol Component Part by weiqht (pbw)

CP-4610 60.2

NC-700 24.2

CP-1421 2.0

Monoethylene Glycol 5.7

Dabco 33LV 0.66

Forane 141-b 7.1

Red Pigment 0.2

Isocyanate component

ISONATE M 340 40.0

Index 100

Soft Foam Formulation

Polvol Component Part by weiqht (pbw)

CP-6001 100

Water 3.5

Niax A-l 0.12

Dabco 33LV 0.40

B-4113 0.40

Isocyanate component

NE-112

Index 90

The operating conditions were as follows: the polyol and polyisocyanate streams were 20°C. The pressures for the polyol and polyisocyanate streams were 160 bars and 150 bars respectively. Total output for soft foam formulation was about 200 g/s and for the elastomeric formulation was about 300 g/s. Total weight of soft foam formulation poured into the mold was 1000 grams and total weight of elastomeric formulation poured into the mold was 300 g.

After strip-wise pouring of both formulations was completed, the mold was closed with the lid, and the elastomer and foam were allowed to rise and cure for 5 1/2 minutes. Vertical cross-sectional views of the foam are shown in Figures 2 and 3. The shaded area represents the elastomeric layer containing the red dye. The vertical and horizontal cross- sections were taken along the line A - A' and between b - c of the resulting demolded seat cushion. The resulting demolded foam seat cushion has an excellent seating flat layer of an elastomer on top of a flexible foam. The bottom soft foam layer was approximately 70 mm thick and the top elastomeric layer was about 4 mm thick measured at the middle point of the seat .

Example 3

This example illustrates the formation of a microcellular elastomeric layer on top of a rigid foam. A 9 liter aluminum square mold (30x30x10mm) with a mold temperature 47°C was used. The demold time was approximately 5 and one-half minutes. The elastomeric formulation was poured by hand into the mold, followed 15 seconds later by the rigid foam formulation. After 5 min 30 sec, the resulting demolded part had a layer of a red colored elastomer (3 mm thick) on top of a rigid foam layer of 97 mm thick. After demolding, the produced article had the appearance as illustrated in Figure 4. The shaded area represents the red elastomeric layer.

The composition of the formulations was as follows: Elastomeric Formulation

Polyol Component Part by weiqht (pbw) Quantity (qrams)

CP-4610 58.9 141.5

NC-700 23.6 56.7

CP-1421 2.0 4.8

Monoethylene Glycol 5.6 13.44

Dabco 33LV 0.65 1.56

Forane 141-b 7.0 16.8

Red Pigment 1.8 4.32

Isocyanate component ISONATE M 340 36.88 88.51 Index 100

Rigid Foam Formulation

Polyol Component Part by weight (pbw) Quantity (grams) VORATEC SD 179 100 125 Forane 141b 25 31.2

Isocyanate component M-229 144 180

Index 115

Example 4

The procedure of Example 3 was followed except a metallic insert was placed on the surface of the- mold. The demolded article had on its surface a finger-print of the metallic insert placed on the mold. This is illustrated in Figures 5a and 5b . Example 5

This example illustrates the formation of an elastomeric layer on a soft foam covered by an in-mold coating. A square mold (85cmx85cmx5cm) was employed. The mold was made of aluminum and arranged so that the bottom surface was inclined 5 degrees in relation to the horizontal plane. The inside surfaces of the mold were kept at 47°C and were sprayed with the Acmosil 180 mold release agent sold by ACMOS and then a 1- component brown color system in mold coating coded Bomix PUR- IMC V 2111/150 obtained from Bomix-Chemie GmbH & Co. was sprayed into the mold. Two mixing heads were connected to respectively a Krauss Maffei RIMSTAR 40 and a Krauss Maffei KK 10 machine. The two mixing heads outlets were mounted on a 5- axes ASEA 90 robot. The mixing heads outlets were used to dispense respectively elastomeric and soft liquid foam formulations. The composition of the formulations was as follows :

Elastomeric Formulation

Polvol Component Part by weight (pbw)

VORANOL CP-4702 90

CP-1421 2.0

Monoethylene Glycol 4.0

Dabco 33LV 0.65

Forane 141-b 3.5

Isocyanate component ISONATE M 340 30.5

Index 100 Soft Foam Formulation

Polyol Component Part by weight (pbw)

VORANOL CP-6001 49.5

VORANOL 4053 1.0

SPECFLEX NC 632 49.5

Water 3.71

DEOA 85% 0.59

Niax A-l 0.15

Dabco 33LV 0.40

B-8715 0.50

Isocyanate component SPECFLEX NE 181 62.1 Index 90

The operating conditions were as follows : the polyol and polyisocyanate streams were 20°C. The pressures for the polyol and polyisocyanate streams were 160 bars and 150 bars respectively. Total output for soft foam formulation was about 300 g/s and for the elastomeric formulation about 360 g/s. Total weight of soft foam formulation poured into the mold was 2150 grams and total weight of elastomeric formulation poured into the mold was 1950 g.

After strip-wise pouring of both formulations was completed, the mold was closed with the lid, and the formulations were allowed to react and/or rise and cure for 5

1/2 minutes. The resulting demolded part had a seating zone of a thin layer surface of the brown bomix PUR-IMC V 2111/150 on top of an excellent flat layer of the elastomer which is on top of a soft flexible foam. Example 6

The procedure was as for Example 5 except that a 2- component in-mold coating system, Saturn grey 7E72 color, was used to spray the mold before pouring the elastomeric and the soft foam formulations. The 2-component in-mold coating was prepared by mixing Bomix PUR-IMC 1053/73 with Bomix Hardener 26/111, both obtained from Bomix-Chemie GmbH & Co. in a ratio 100:20 parts by weight.

Example 7

The procedure of Example 6 was followed with the exception that the composition of the elastomeric formulation did not contain an auxiliary-blowing agent. The elastomeric formulation was as follows:

Elastomeric Formulation

Polvol Component Part by weight (pbw)

VORANOL CP-4702 90

CP-1421 2.0

Monoethylene Glycol 4.0

Dabco 33LV 0.50

Isocyanate component ISONATE M 340 30.5

Index 100

The resulting demolded article, was a seat with a seating zone of an elastomeric layer over a flexible foam. Example 8

This example illustrates the formation of a 3 layered article using an 8 liter aluminum square mold (40x40x5cm) . The bottom surface of the mold was inclined from the back to the front of the mold at an angle of 5 degrees to the horizontal plane. Mold temperature was 45°C and demold time was 5 and one half minutes. The elastomeric formulation nr 1 was poured by hand into the mold through the upper line of the inclined mold followed 10 seconds later by the viscoelastic foam formulation nr 2, then 5 seconds after this second addition, a third flex formulation nr 3 was added. After 5 min 30 s, the resulting demolded part had a layer of a yellow colored elastomer on top of a blue viscoelastic layer on top of a flexible foam.

The composition of the three formulations was as follows

Elastomer Formulation (nr 1)

Polvol Component Part by weight (pbw) Quantity (grams)

VORANOL CP-4702 90 488

CP-1421 2.0 10

Monoethylene Glycol 4.0 20

Dabco 33LV 0.65 3.23

Forane 141-b 3.5 17.4

Yellow Pigment 0.1 0.5

Isocyanate component

ISONATE M 340 30.5 _ 152

Index 100 Viscoelastic foam formulation (nr 2 )

Polvol Component Part by weight (pbw) Quantity (grams)

VORANOL CP 6001 13.5 43

VORANOL CP 3001 18 57

VORANOL EP 1900 23 73

VORANOL CP 1421 18 57

VORANOL CP 450 24 76

Water 2.20 7.0

Niax A-l 0.05 0.16

Dabco 33LV 0.20 0.63

B-4113 0.50 1.60

Blue pigment 0.05 0.16

Isocyanate component SPECFLEX NS 540 32 102

Index 63

Soft Foam Formulation (nr 3]

Polvol Component Part by weiqht (pbw) Quantity (qrams)

SPECFLEX NC 632 70 214

SPECFLEX NC 700 30 92

Water (total) 2.5 7.65

DEOA pure 1.2 3.67

Niax A-l 0.05 0.15

Dabco 33LV 0.20 0.61

Silicone B-8708 0.40 1.22

Isocyanate component VORANATE T-80 31.8 97 Index 100 It should be understood that the present invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to a person skilled in the art are included within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A process for producing a multi- layered molded foam comprising pouring into an open mold a first formulation for producing an elastomer and before the elastomer is completely cured, pouring a second formulation for producing a foam into the mold, closing the mold and after the foam and elastomer have cured, demolding the article.

2. The process of Claim 1 wherein the second formulation is a formulation for producing a flexible foam.

3. The process of Claim 2 wherein the molded foam article is a seating element for an automobile seat.

4. The process of claim 2 wherein the molded foam article is a furniture element, mat or sport carpet.

5. The process of Claim 1 wherein the second formulation is for producing a rigid foam.

6. The process of Claim 1 wherein the elastomer is a polyurethane, polyurea, polyacrylate , polyisoprene, polychloroprene, nitrile, polybutylene, silicone rubber, block copolymers of monomers of styrene and butadiene, or a combination thereof.

7. The process of Claim 6 wherein the elastomer is a polyurethane

8. The process of Claim 7 wherein the elastomer is a microcellular elastomer.

9. The process of Claim 1 wherein the elastomer and foam formulations are poured sequentially from a single mixing head.

10. The process of Claim 9 wherein the formulations are poured strip-wise into the open mold onto the seating portion of the mold.

11. The process of Claim 9 wherein the mold moves relative to the mixing head outlet during the pouring of the formulations.

12. The process of Claim 1 wherein the first and second formulations are poured from different mixing head outlets.

13. The process of Claim 1 wherein (a) the first formulation is poured across the seating zone of a mold, strip- wise from a mixing head outlet, into the mold along a line parallel to and near to the external wall of the seating zone of the mold and (b) pouring across the seating zone of the mold, strip-wise from the same or different mixing head outlet, the second formulation into the mold along a line parallel to and nearer to the external wall of the mold than the line of pouring of the first formulation and allowing the second formulation to spread on top of the first formulation.

14. The process of Claim 13 wherein the formulations are poured simultaneously from several mixing head outlets strip- wise into the seating zone of the mold along different lines while the mixing heads move above and across the seating zone of the mold.

15. The process of Claim 13 wherein the formulations are poured sequentially from a single mixing head strip-wise into the seating zone of the mold along different lines across the seating zone of the mold.

16. The process according to Claim 1 wherein the mixing heads outlets are kept vertical relative to the horizontal plane while the liquid formulations are being poured into the mold.

17. The process according to Claim 1 wherein the mixing heads outlets are tilted relative to the vertical plane while the liquid formulations are being poured into the mold.

18. A foamed article produced by the process of any one of Claims 1 to 17.

19. A process for producing a three-layered foam article, in a mold arranged so that the bottom surface of the mold is flat or inclined to the horizontal plane, comprises the following steps:

(a) pouring from a mixing head outlet, a first liquid formulation designed to produce an elastomer layer into the mold and before the elastomer layer has cured;

(b) pouring from the same or different mixing head outlet, a second formulation designed to produce a foam into the mold and allowing the second liquid foam formulation to spread on top of the first formulation and before complete curing of the first and second formulations;

(c) pouring from the same or different mixing head outlet, a third formulation designed to produce a foam having a different density and/or hardness than the foam of (b) into the mold and allowing the third liquid foam formulation to spread on top of second liquid foam formulation.