Semi-rigid polyurethane foam formulations and methods for making foamed parts

Abstract

A composite having a polymer or natural leather skin layer and a polyurethane foam layer is produced by a molding process. The polyurethane foam layer is produced from a foam formulation containing a specific polyester polyol. The presence of the polyester polyol improves the flow characteristics of the foam formulation. The foam produced in this way has an unexpectedly low VOC content.

Description

[Technical Field]

[0001] The present invention relates to semi-rigid polyurethane foam formulations and methods for making foamed parts.

[0002] Certain automotive interior parts, such as instrument panels, door panels, and armrests, are manufactured with an exterior decorative skin backed with a layer of semi-flexible polyurethane foam. These parts are made in a molding process in which the skin is placed in a mold. Both open-pore and closed-pore manufacturing processes can be used. A liquid mixture of foam precursors is injected (in a closed-pore process) or poured (in an open-pore process) into the mold, where the mixture reacts and expands against the skin to form the part. A substrate is typically incorporated into the part during the manufacturing process and adheres to the foam layer on the side opposite the skin.

[0003] This type of automotive interior part is typically a long, slender part with a thin foam layer. In the closed-pour process, the foam formulation is usually injected into the mold through one or two injection ports. Once injected, the foam formulation must be able to flow throughout the entire mold cavity, filling it without leaving voids or other defects. This is complicated by the thin thickness of the foam cavity, the considerable distance from the injection port to the remote portion of the mold, and the often complex shape of the mold cavity. Parts with complex geometries are produced in correspondingly complex molds, which often define additional flow restrictions. If the foam formulation does not flow well, more formulation is required to completely fill the mold, which produces a denser foam. This requires more raw material and therefore higher costs. Therefore, good flow characteristics are highly desirable.

[0004] It is also important that the cured foam has a low level of volatile organic compounds (VOCs). VOCs escape from the foam over time or during post-molding fabrication steps, such as creating cutouts for installing vents and other components. In some cases, amine compounds contained in the foam can promote embrittlement and discoloration of some skin materials, especially PVC skins. In addition, the released VOCs can deposit on automobile windshields and cause fogging.

[0005] The present invention, in one aspect, comprises: A) introducing a polymer or natural leather skin layer and optionally a substrate into a cavity of the mold such that the polymer or natural leather skin layer is positioned against at least one interior surface of the mold to produce an unfilled region of the mold cavity adjacent to the polymer or natural leather skin layer and having a thickness of up to 25.4 mm; B) introducing a polyurethane foam formulation into an unfilled region of the mold cavity through one or more injection ports; C) closing the mold before or after step B); D) curing the polyurethane foam formulation in the closed mold such that the polyurethane foam formulation expands, contacts the exposed surface of the polymer or natural leather skin layer, and fills the unfilled areas of the mold cavity to form a polyurethane foam that adheres to the polymer or natural leather skin layer and, if present, the substrate, wherein the polyurethane foam formulation is I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate.

[0006] In another aspect, the present invention provides a method for producing a pharmaceutical composition comprising: 1) an outer polymer skin; 2) a polyurethane layer having a thickness of up to 25.4 mm in contact with and adhered to the polymer skin; The polyurethane layer is I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate.

[0007] In a third aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst.

[0008] The present invention offers the important advantages of having excellent flow and low VOC in the cured foam. In addition, foams produced according to the present invention have useful mechanical properties.

[0009] The skinned composite is produced in a molding process. The mold is characterized by having a mold cavity dimensioned such that after the polymer or natural leather skin layer and optional substrate are placed in the mold, the remaining unfilled portion of the cavity adjacent to the polymer or natural leather skin is 25.4 mm or less in thickness (i.e., its smallest dimension). The unfilled portion of the mold cavity can be 20 mm or less in thickness, or 16 mm or less in thickness. It is typically at least 2 mm thick. The thickness may or may not be constant along the entire length and / or width of the unfilled portion of the mold cavity.

[0010] The unfilled portion of the mold cavity can have a length (longest dimension) ranging from, for example, 10 cm up to 250 cm. The present invention is particularly advantageous when the unfilled portion of the mold cavity (and the resulting foam layer) has a long length-to-thickness ratio. This ratio in some embodiments can be, for example, at least 5, at least 25, at least 50, or at least 100, and can be up to 500 or up to 250.

[0011] The width of the unfilled portion of the mold cavity is at least as great as its thickness and may be as great as its length. In some embodiments, the width may be 10 cm to 150 cm or 15 cm to 100 cm. The width may vary along the length of the mold.

[0012] In some embodiments, the mold is characterized by having one or more injection ports through which the polyurethane foam formulation is introduced into the unfilled portion of the mold cavity. The injection ports may be located at any convenient location along the length of the mold. The invention is particularly beneficial when the injection port or ports are positioned so that the foam formulation must flow at least 5 cm, particularly at least 10 cm, at least 25 cm, at least 50 cm, or even at least 100 cm from the injection port to completely fill the unfilled portion of the mold cavity. The good flow characteristics of the foam formulation are particularly beneficial in such cases where the flow path is narrow and elongated.

[0013] The mold can be made of any material that can withstand the temperatures and pressures of the molding process without deformation. Metal, ceramic, and various composite molds are all suitable.

[0014] A layer of polymer or natural leather skin is disposed in the mold adjacent at least one side of the mold cavity. If it is desired to provide a skin layer on both sides of the polyurethane foam layer, two skin layers may be placed in the mold, adjacent each other on opposite sides, to define an unfilled portion of the mold cavity therebetween.

[0015] The polymer or natural leather skin layer may have a thickness of, for example, 0.25 to 6 mm, more typically 0.5 to 2 mm. The polymer skin can be formed by any suitable method, including various extrusion and casting methods, but preferred methods for creating the skin are dip molding or slush molding. The polymer skin can include various surface features, such as grain or other surface texturing, for example, to simulate the appearance of natural leather. In certain embodiments, the skin contains weakened areas, such as score lines, that allow the skin to split along predetermined lines when subjected to a specific applied force, such as an airbag deployment. Such score lines may be present on the exposed and / or inner surfaces of the skin.

[0016] The polymer skin comprises at least one thermoplastic polymer. The thermoplastic polymer may be, for example, a vinyl chloride polymer or copolymer; a vinylidene chloride copolymer polymer, polyethylene, polypropylene, or a polyolefin such as a so-called thermoplastic polyolefin (TPO), a thermosetting or thermoplastic polyurethane, etc. Vinyl chloride polymers and copolymers are preferred thermoplastic films.

[0017] The polymer skin may contain a plasticizer, which is a solvent for the thermoplastic polymer, preferably having a boiling point at standard pressure of at least 150°C, more preferably at least 200°C, and a low vapor pressure at temperatures below 100°C. The plasticizer preferably has a molecular weight of at least 100, preferably at least 200, more preferably at least 250, and may have a molecular weight of around 4000, but more typically about 1500 or less.

[0018] Among suitable plasticizers are various carboxylic acid ester compounds, such as bis(2-ethylhexyl) phthalate, diisononyl phthalate, bis(n-butyl) phthalate, butyl benzyl phthalate, diisodecyl phthalate, diethyl phthalate, diisobutyl phthalate, di-n-hexyl phthalate, trimethyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-(n-octyl, n-decyl) trimellitate, tri-(heptyl, nonyl) trimellitate, n-octyl trimellitate, bis(2-ethylhexyl) adipate, dimethyl adipate, monomethyl adipate, dioctyl adipate, dibutyl sebacate, dibutyl maleate, diisobutyl maleate, various benzoic acid esters, various vegetable oils and modified vegetable oils (e.g., epoxidized vegetable oils), various sulfonamides, such as n-ethyl phthalate, diisobutyl ... N-(2-hydroxypropyl)benzenesulfonamide, N-(n-butyl)benzenesulfonamide (DOA), various phosphate esters such as tricresyl phosphate and tributyl phosphate, glycol esters such as triethylene glycol dihexanoate and tetraethylene glycol diheptanoate, polybutene polymers, various acetylated monoglycerides, alkyl citrates such as triethyl citrate, acetyltriethyl citrate, tributyl citrate, trioctyl citrate, acetyltrioctyl citrate, acetyltributyl citrate, and butyryltrihexyl citrate; alkylsulfonic acid phenyl esters; and 1,2-cyclohexanedicarboxylate diesters such as 1,2-cyclohexanediisononyl ester.

[0019] The skin may also be made of natural materials such as natural leather.

[0020] The skin may contain small amounts of other materials that may be useful. Among these are various colorants, which may be solid pigments and / or various types of dyes. The polymer skin may also contain one or more stabilizers, fillers, preservatives, biocides, UV screeners, flame retardants, etc.

[0021] Optionally, a substrate different from the skin layer may be disposed in the mold, and if present, such substrate is disposed so as to define an unfilled portion of the mold cavity between the substrate and the skin layer.

[0022] The substrate can be made of a wide variety of substances, such as engineering thermoplastics or thermosets, wood, metal, ceramic, or other materials that meet the requirements of the composite's intended use. The substrate must be able to withstand the conditions of the polyurethane-forming reaction without deformation. In most cases, the function of the substrate is to provide rigidity and provide attachment points for other components or auxiliary devices.

[0023] The polyurethane foam formulation is introduced into the mold, typically into a closed mold through one or more injection points as described above, although in some embodiments the polyurethane foam formulation can be poured into an open mold. Enough polyurethane foam formulation is introduced to fill the unfilled portion of the mold cavity, preferably at a rate of 250 kg / m 3 Produce foams having the following foam densities: The foam density is at least 25 kg / m 3 , maximum at most 80 kg / m 3 , or at most 64 kg / m 3 It could be.

[0024] The foam formulation fills the unfilled portion of the mold adjacent to the skin layer, expands, and reacts to form a polyurethane foam. The mold should remain closed until the foam formulation has cured sufficiently to allow the part to be demolded without permanent deformation or damage to the foam layer. Cure times can range from 1 minute to 5 hours, for example.

[0025] The polyurethane-forming reaction is exothermic. Therefore, it may not be necessary to apply heat to accelerate curing, although it is within the scope of the present invention to do so. The temperature should not exceed the melting temperature of the skin, but should not be so high as to melt, deteriorate, or distort the skin and / or substrate. Curing in the mold is continued until an adhesive bond is formed between the skin, polyurethane layer, and substrate, which bond is strong enough to allow the composite to be demolded without permanent damage.

[0026] The polyurethane layer is the reaction product of certain isocyanate-reactive materials, at least one organic polyisocyanate, and a polyurethane foam formulation containing a urethane catalyst.

[0027] The isocyanate-reactive material includes a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000. The isocyanate-reactive material a) may have a nominal functionality of at least 3. In some embodiments, the hydroxyl equivalent weight is at least 1200, at least 1500, or at least 1750, and in some embodiments, the hydroxyl equivalent weight is at most 2500, at most 2200, or at most 2100.

[0028] There can be a mixture of two or more isocyanate-reactive materials a) . Such a mixture can include one or more polyols having a nominal hydroxyl functionality of 2 to 3 and a hydroxyl equivalent weight as described above, and one or more polyols having a nominal functionality of 4 to 8, again having a hydroxyl equivalent weight as described above. The number average nominal functionality a) of the mixture of isocyanate-reactive materials can be, for example, 2.5 to 5, 3 to 4.5, or 3.2 to 4.

[0029] The isocyanate-reactive materials a) are polyether polyols. They are preferably homopolymers of propylene oxide and / or block and / or random copolymers of propylene oxide and ethylene oxide. In the latter case, the oxyethylene units may constitute up to 50%, preferably up to 30% or up to 25% of the total weight of the polyether polyol.

[0030] Isocyanate-reactive material a) may comprise 50-90% of the total weight of all isocyanate-reactive materials in the foam formulation. An "isocyanate-reactive material" is a compound having one or more hydroxyl, primary amino, and / or secondary amino groups, including water. In some embodiments, isocyanate-reactive material a) comprises at least 60% or at least 65% of the total weight of all isocyanate-reactive materials in the foam formulation, and up to 85%, up to 80%, or up to 75% of the total weight of all isocyanate-reactive materials.

[0031] In some embodiments, the mixture of isocyanate-reactive materials a) comprises at least one nominally trifunctional polyol having a functionality of 3 that constitutes 50-70%, preferably 55-65%, of the total weight of all isocyanate-reactive materials in the foam formulation, and at least one polyol having a functionality of at least 4 that constitutes 5-25%, preferably 10-20%, of the total weight of all isocyanate-reactive materials in the foam formulation.

[0032] The isocyanate-reactive material also includes b) at least one crosslinker having at least three isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125. Examples of such crosslinkers include mono-, di-, or trikanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, and aminoethylethanolamine; alkylene polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and the like; glycerin; trimethylolpropane; trimethylolethane, sucrose, mannitol, sorbitol, and the like, as well as alkoxylates of any of the above. In some embodiments, at least one mono-, di-, and / or trialkanolamine is present. In some embodiments, at least one mono-, di-, and / or trialkanolamine and at least one polyol having at least three hydroxyl groups per molecule are present.

[0033] Isocyanate-reactive material b) may, for example, comprise 0.1 to 20 percent of the total weight of all isocyanate-reactive materials in the foam formulation. In some embodiments, isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, comprising 0.1 to 2 percent, specifically 0.25 to 1.5 percent, of the total weight of all isocyanate-reactive materials in the foam formulation, and may additionally contain a polyether polyol having a hydroxyl equivalent weight of 60 to 125, comprising 1 to 19 percent, specifically 5 to 14 percent, of the total weight of all isocyanate-reactive materials in the foam formulation.

[0034] Isocyanate-reactive material c) is one or more polyester polyols having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4. The hydroxyl equivalent weight can be at least 175, at least 200, at least 250, or at least 300. The functionality in some embodiments is 2 to 3. Isocyanate-reactive material c) is i) hydroxy-functional triglycerides, and ii) polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150.

[0035] Hydroxyl-functional triglycerides correspond to the reaction products of glycerin and fatty acids, which may or may not all be identical. The fatty acid groups may have 6 to 30 carbon atoms, particularly 12 to 24 carbon atoms or 12 to 18 carbon atoms. Hydroxyl-functional triglycerides include oils and fats produced by biological processes by plants and / or animals. Castor oil is an example of such a triglyceride. Hydroxyl-functional triglycerides also include various oils and fats that have typically been modified by oxidation or hydrolysis of one or more carbon-carbon double bonds to introduce hydroxyl groups. Examples of the latter type of hydroxyl-functional triglycerides include so-called "blown" soybean oil, which has been oxidized or hydrolyzed to introduce hydroxyl groups, as described in U.S. Published Patent Applications Nos. 2002 / 0121328, 2002 / 0119321, and 2002 / 0090488.

[0036] Polyesters of C6-C18 dicarboxylic acids and one or more short-chain polyols include the reaction products of one or more α,ω-alkanoic dicarboxylic acids having 6 to 18 carbon atoms with one or more short-chain polyols. α,ω-alkanoic dicarboxylic acids can be produced from long-chain alkenoic acids by ozonolysis. Ozonolysis cleaves the double bond, producing a mixture of mono- and di-acids. Di-acids are useful starting materials for making polyesters ii). In some embodiments, the dicarboxylic acid includes azelaic acid, which can be obtained from certain unsaturated fatty acids or vegetable oils via ozonolysis.

[0037] The short-chain polyols used to make polyester ii) can have a molecular weight of up to 150 and 2 to 6 hydroxyl groups. The short-chain polyols can be, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, trimethylolethane, sorbitol, sucrose, mannitol, etc., alkoxylates of any of the above, or mixtures of any two or more of the above.

[0038] Among useful isocyanate-reactive materials c)ii) are the branched azelaic acid / ethylene glycol polyesters sold by Emery Oleochemicals as Emerox® 14001, Emerox® 14050, Emerox® 14055, Emerox® 14250, Emerox® 14270, and Emerox® 14275.

[0039] Mixtures of any two or more of the above polyols c) can be used.

[0040] Isocyanate-reactive material c) may, for example, constitute at least 5 percent, at least 7 percent, or at least 10 percent, and as much as 30 percent, 20 percent, or as much as 15 percent, of the total weight of all isocyanate-reactive materials in the foam formulation.

[0041] In addition to isocyanate-reactive materials a), b), and c), isocyanate-reactive material (I) may further comprise one or more polyols. Examples of such polyols include polyester polyols different from isocyanate-reactive material c), such as aromatic polyesters, aliphatic polyesters of acyclic dicarboxylic acids having fewer than six carbon atoms, or aliphatic polyesters of cycloaliphatic dicarboxylic acids. Further examples of such polyols include one or more polyether polyols having a hydroxyl equivalent weight of 126 to 999. If present, such additional polyols preferably constitute no more than 15 percent, no more than 10%, or no more than 5% of the total weight of all isocyanate-reactive materials in the foam formulation.

[0042] The foam formulation contains water, which reacts with isocyanate groups to produce urea linkages and generate carbon dioxide, which functions as a blowing agent. Water may comprise at least 1 percent or at least 2 percent of the total weight of all isocyanate-reactive materials in the foam formulation, and up to 6%, up to 5%, up to 4%, or up to 3.5% of the total weight of all isocyanate-reactive materials in the foam formulation.

[0043] The foam formulation contains at least one urethane catalyst, i.e., at least one catalyst for the reaction of isocyanate groups with alcohol or water. Useful catalysts include various tertiary amine compounds, various tin compounds, and other metallic polyurethane catalysts, including those described in U.S. Pat. No. 4,390,645. A preferred type of catalyst is the so-called "reactive" amine catalyst, which contains at least one tertiary amino group and at least one isocyanate-reactive group, typically a hydroxyl, primary amino, or secondary amino group. This type of catalyst reacts to form a polymer structure as the reaction mixture cures. Examples of reactive amine catalysts include 2-propanol, 1,1'-[[3-(dimethylamino)propyl]imino]bis-, 1,3-propanediamine, N-1-[2-[2[(dimethylamino)ethoxy]ethyl]-N-1-methyl, ethanol, 2-[[2-[2-(dimethylamino)ethoxy]ethyl]methylamino, and 1,3-propanediamine, N-3-[3-(dimethylamino)propyl]-N-1,N-1-dimethyl, and the like.

[0044] The organic isocyanate compound contains an average of at least 1.5, preferably at least 2.0, isocyanate groups per molecule. The polyisocyanate may contain an average of as many as eight isocyanate groups per molecule, but typically contains an average of no more than about four isocyanate groups per molecule. The organic polyisocyanate may have an isocyanate equivalent weight of as little as about 85 and as much as about 500, preferably up to 250 or up to 175.

[0045] The isocyanate groups may be attached to aromatic, aliphatic, or alicyclic carbon atoms. Examples of suitable isocyanate compounds include m-phenylene diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate, naphthylene-1,5-diisocyanate, methoxyphenyl-2,4-diisocyanate, diphenyl ether, methyl methyl ether, ... Phenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, diphenylmethane-2,2'-diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4',4"-triphenylmethane Examples of suitable polyisocyanates include triisocyanates, polymethylene polyphenylisocyanate (PMDI), toluene-2,4,6-triisocyanate, and 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate. Preferably, the polyisocyanate compound is diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, PMDI, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, or a mixture of any two or more thereof. Diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, and mixtures thereof, collectively referred to as MDI, can all be used. Toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, and mixtures thereof, collectively referred to as TDI, can all be used.

[0046] Any of the above isocyanates can be modified to contain urethane, urea, biuret, carbodiimide, allophanate, uretonimine, isocyanurate, amide, or similar linkages. Examples of these types of modified isocyanates include various urethane and / or urea group-containing prepolymers, so-called "liquid MDI" products, and the like.

[0047] The organic polyisocyanate is provided in an amount to provide an isocyanate index of at least 80 and up to 125. In some embodiments, the isocyanate index is at least 90 or at least 100. Increasing the isocyanate index within these ranges has been found to tend to reduce the VOC of the foam. It also tends to increase the tensile and tear strength.

[0048] The foam formulation may contain a trimerization catalyst, i.e., a material that catalyzes the trimerization of isocyanate groups to form isocyanurate groups. Examples of such strong trimerization catalysts include strong bases such as alkali metal salts and ammonium salts. However, such trimerization catalysts are optional and may be omitted.

[0049] The reaction mixture may contain one or more foam-stabilizing surfactants (especially if the polyurethane is cellular). Examples of optional surfactants include amine salts of alkali metals and fatty acids; amine salts of alkali metals and sulfonic acids; siloxane-oxyalkylene polymers or copolymers and other organopolysiloxanes; oxyethylated alkylphenols; oxyethylated fatty alcohols such as TERGITOL™ 15-S-9 from The Dow Chemical Company; paraffin oil; ricinoleic acid esters; turmeric oil; peanut oil; paraffin; fatty alcohols; dimethylpolysiloxanes; and oligomeric acrylates with polyoxyalkylene and fluoroalkane side groups. These surfactants are generally used in amounts of 0.05 to 2 parts by weight (if at all), based on 100 parts by weight of the polyol (i.e., components a), b), and c), and optional polyol. Organosilicon surfactants are generally the preferred type. However, an advantage of the present invention is that such foam-stabilizing surfactants are often unnecessary and can be omitted. Thus, in some embodiments, the foam formulation contains less than 0.05 parts by weight, preferably less than 0.1 parts by weight, of any of the above foam stabilizing surfactants per 100 parts by weight of polyol.

[0050] The reaction mixture may additionally contain other optional ingredients such as, for example, one or more physical blowing agents, one or more fillers, one or more colorants, one or more reinforcing agents, antioxidants, UV absorbers, flame retardants, biocides, and the like.

[0051] The product of the present invention is a skinned composite. The skin layer is a polymer layer. The skin layer is directly bonded to a polyurethane foam layer having a thickness of at most 25.4 mm. The foam density is preferably at least 25 kg / m. 3 ~250kg / m 3The polyurethane foam layer may be bonded to a second skin layer to form a sandwich structure. The polyurethane foam layer may be completely surrounded by the skin layer, in which case the skin layer adheres to and covers all exterior surfaces of the foam layer. In addition to being bonded to the skin layer, the polyurethane foam layer may also be bonded to a substrate as described above.

[0052] The composites of the present invention are useful in a wide range of vehicle and construction applications. Because the skin layer is primarily functionally decorative, the composites are particularly useful as trim or decorative components. In vehicle applications, the composites of the present invention can be used, for example, as instrument panels, interior door panels, rear window shelves, steering wheels, console covers, and the like.

[0053] The following examples are provided to illustrate the present invention, but are not intended to limit the scope of the invention. All parts and percentages are by weight unless otherwise indicated. All molecular weights are number averages by gel permeation chromatography.

[0054] Polyol A is a polyoxyethylene-capped polyoxypropylene polyether polyol of 2040 equivalent weight having a nominal functionality of 3. It contains 15% by weight of oxyethylene units.

[0055] Polyol B is a nominally trifunctional poly(propylene oxide) with a number average molecular weight of 250 (equivalent weight about 85).

[0056] Polyol C is an 1800 equivalent weight polyoxyethylene-capped polyoxypropylene polyether polyol having a nominal functionality of 6.9.

[0057] Polyol D is a copolymer polyol having an equivalent weight of 1030. The base polyol is a polyoxyethylene-capped polyoxypropylene having a nominal functionality of 3. The dispersed polymer particles are styrene-acrylonitrile particles. The solids content is about 40% by weight.

[0058] Polyol E is a polyoxyethylene-capped polyoxypropylene of 1800 equivalent weight with a nominal functionality of 4.2. It contains approximately 15.5% oxyethylene units.

[0059] Polyester 1 is castor oil.

[0060] Polyester 2 is a "blown" soybean oil with an average functionality of 2 and a hydroxyl number of 110.

[0061] Polyester 3 is a branched ethylene glycol / azelaic acid polyester polyol with a hydroxyl number (1122 equivalent weight) of 50. It contains primarily primary hydroxyl groups.

[0062] Polyester 4 is a di(ethylene adipate) diol having a hydroxyl number of 225 (250 equivalent weight).

[0063] Polyester 5 is made from scrap polyurethane foam. It has a hydroxyl number of 170 (330 equivalent weight).

[0064] DEOA is an 85% diethanolamine product.

[0065] TEOA is 99% triethanolamine.

[0066] Catalysts A, B, and C are each a mixture of an amine blow catalyst and a gelling catalyst.

[0067] PMDI is a polymeric MDI with an isocyanate functionality of about 2.3 and an isocyanate equivalent weight of 132.

[0068] Foam Examples 1-5 and Comparative Samples A-C are made using the ingredients listed in Table 1.

[0069] Foam for VOC testing is made by mixing all components except polymeric MDI in a beaker. The PMDI is then stirred for 6 seconds using a high-speed mixer. 90-100 grams of the resulting foam formulation is poured into a paper cup and allowed to rise freely and harden to produce the foam. This foam is used for VOC measurement testing.

[0070] Foams for physical property testing are made by combining all components except PMDI into the blended polyol component. The blended polyol component and PMDI are processed using a high-pressure impingement mixer to form a reaction mixture. The component temperature is approximately 26°C. Additional portions are dispensed into enclosed, room-temperature aluminum molds measuring 12.7 mm deep, 152 mm wide, and 701 mm long. In each case, the foam formulation is injected into one end of the mold and allowed to flow the entire length of the mold. Foam density and other physical properties are measured, as shown in Table 2. The minimum fill density, i.e., the density of the lowest-density foam sample that completely fills the mold, is determined as an indicator of the formulation's flow characteristics.

[0071] The VOC, physical property, and flow test results are shown in Table 2. [Table 1] [Table 2]

[0072] The inventive examples exhibit superior flow characteristics, as evidenced by their lower minimum packing density values. A smaller amount of foam formulation is required to fill long, very small cross-section molds. This attribute allows the foam formulation to be easily used in making instrument panel foams and other foams with elongated shapes, where the foam formulation must travel significant distances through restrictive channels to completely fill the mold and produce defect-free parts. Because less foam formulation is required to produce such parts, the parts weigh less and raw material costs are reduced.

[0073] The VOCs of foam examples 1-7 (especially examples 3-6) were also significantly lower than the comparative samples, in some cases by up to 75%. This is a significant advantage for making instrument panel foams and other foam parts used in enclosed environments. Reducing VOCs in instrument panel foams can reduce discoloration of plastic cover layers, reduce windshield fogging, and reduce odors. The inventions described in the original claims of this application are set forth below. [1] A process for forming a skinned composite, comprising: A) introducing a polymer or natural leather skin layer and optionally a substrate into a cavity of the mold such that the polymer or natural leather skin layer is positioned against at least one interior surface of the mold to produce an unfilled region of the mold cavity adjacent to the polymer or natural leather skin layer and having a thickness of up to 25.4 mm; B) introducing a polyurethane foam formulation into the unfilled region of the mold cavity through one or more injection ports; C) closing the mold before and after step B); D) curing the polyurethane foam formulation in the closed mold so that the polyurethane foam formulation expands, contacts the exposed surface of the polymer or natural leather skin layer, fills the unfilled areas of the mold cavity, and forms a polyurethane foam that adheres to the polymer or natural leather skin layer and, if present, to the substrate, wherein the polyurethane foam formulation I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate. [2] The process of [1], wherein the isocyanate-reactive material c) comprises castor oil. [3] The process of [1] or [2], wherein the isocyanate-reactive material c) comprises a branched azelaic acid / ethylene glycol polyester. [4] The process according to any one of [1] to [3], wherein the isocyanate-reactive material c) comprises diethyl adipate polyester. [5] The process of any of [1] to [5], wherein isocyanate-reactive material a) comprises 60 to 75% of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine comprises 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) comprises 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation. [6] The process according to any one of [1] to [5], wherein the mold is closed and the polyurethane foam is injected into the closed mold through one or more injection ports. [7] The process of [6], wherein the injection port is positioned so that the foam formulation flows at least 50 cm from the injection port to completely fill the unfilled portion of the mold cavity. [8] The process according to any one of [1] to [7], wherein the substrate is present and the skin has a thickness of 0.5 to 2 mm. [9] A composite covered with a skin, 1) an outer polymer or natural leather skin; 2) a polyurethane layer in contact with and adhered to the polymer skin and having a thickness of up to 25.4 mm; The polyurethane layer I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate; and a skinned composite that is the reaction product of a reaction mixture comprising:

[10] The skinned composite of [9], wherein the isocyanate-reactive material c) comprises one or more of castor oil, branched azelaic acid / ethylene glycol polyester, and diethyl adipate polyester.

[11] The skinned composite of [9] or

[10] , wherein isocyanate-reactive material a) constitutes 60 to 75 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine constitutes 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) constitutes 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation.

[12] A formulated polyol composition comprising: I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) hydroxy-functional triglycerides, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst.

[13] The formulated polyol composition of

[12] , wherein the isocyanate-reactive material c) comprises one or more of castor oil, branched azelaic acid / ethylene glycol polyester, and diethyl adipate polyester.

[14] The formulated polyol composition of

[12] or

[13] , wherein isocyanate-reactive material a) constitutes 60 to 75% of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine constitutes 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) constitutes 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation.

Claims

1. 1. A process for forming a skinned composite, comprising: A) introducing a polymer or natural leather skin layer and optionally a substrate into a cavity of the mold such that the polymer or natural leather skin layer is positioned against at least one inner surface of the mold to produce an unfilled region of the mold cavity adjacent to the polymer or natural leather skin layer and having a thickness of up to 25.4 mm; B) introducing a polyurethane foam formulation into the unfilled region of the mold cavity through one or more injection ports; C) closing the mold before and after step B); D) curing the polyurethane foam formulation in the closed mold so that the polyurethane foam formulation expands, contacts the exposed surface of the polymer or natural leather skin layer, fills the unfilled areas of the mold cavity, and forms a polyurethane foam that adheres to the polymer or natural leather skin layer and, if present, to the substrate, wherein the polyurethane foam formulation I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) a hydroxy-functional triglyceride, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate; the isocyanate-reactive material c) comprises castor oil, soybean oil, or branched azelaic acid / ethylene glycol polyester and diethyl adipate polyester; process.

2. 10. The process of claim 1, wherein the isocyanate-reactive material c) comprises castor oil and diethyl adipate polyester.

3. 10. The process of claim 1, wherein the isocyanate-reactive material c) comprises a branched azelaic acid / ethylene glycol polyester and a diethyl adipate polyester.

4. 4. The process of any one of claims 1 to 3, wherein isocyanate-reactive material a) comprises 60 to 75% of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine comprises 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) comprises 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation.

5. The process of any one of claims 1 to 4, wherein the mold is closed and the polyurethane foam is injected into the closed mold through one or more injection ports.

6. 6. The process of claim 5, wherein the injection port is positioned so that the foam formulation flows at least 50 cm from the injection port to completely fill the unfilled area of the mold cavity.

7. The process of any one of claims 1 to 6, wherein the substrate is present and the skin has a thickness of 0.5 to 2 mm.

8. A skinned composite, 1) an outer polymer or natural leather skin; 2) a polyurethane layer having a thickness of up to 25.4 mm in contact with and adhered to the polymer or natural leather skin; The polyurethane layer I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) a hydroxy-functional triglyceride, and ii) at least one polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; III) at least one organic polyisocyanate; the isocyanate-reactive material c) comprises castor oil, soybean oil, or branched azelaic acid / ethylene glycol polyester and diethyl adipate polyester; Skinned complex.

9. 9. The skinned composite of claim 8, wherein isocyanate-reactive material a) comprises 60 to 75 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine comprises 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) comprises 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation.

10. 1. A formulated polyol composition comprising: I) a) at least one polyether polyol having a nominal hydroxyl functionality of 2 to 8 and a hydroxyl equivalent weight of 1000 to 3000; b) at least one crosslinker having at least 3 isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of up to 125; c) i) a hydroxy-functional triglyceride, and ii) at least one polyester polyol having a hydroxyl equivalent weight of 150 to 1200 and a hydroxyl functionality of 2 to 4 selected from the group consisting of polyesters of C6-C18 acyclic dicarboxylic acids and one or more short chain polyols having two or more hydroxyl groups per molecule and a molecular weight of up to 150; and d) water; and II) at least one urethane catalyst; the isocyanate-reactive material c) comprises castor oil, soybean oil, or branched azelaic acid / ethylene glycol polyester and diethyl adipate polyester; Formulated polyol composition.

11. 11. The compounded polyol composition of claim 10, wherein isocyanate-reactive material a) comprises 60 to 75 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; isocyanate-reactive material b) comprises at least one mono-, di-, and / or trialkanolamine, wherein the mono-, di-, and / or trialkanolamine comprises 0.1 to 2 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation; and isocyanate-reactive material c) comprises 7 to 15 percent of the total weight of all isocyanate-reactive materials in the polyurethane foam formulation.

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