COMPOSITE ELEMENTS MADE FROM THERMOPLASTIC MATERIALS AND POLYURETHANES, METHOD FOR PRODUCING SAME, AND USE THEREOF

Abstract

The invention relates to: composite elements comprising a thermoplastic material and a polyurethane adhering to said thermoplastic material; a method for producing same; and the use thereof.

Claims

1. A composite element comprising a thermoplastic adjoined in adhering fashion by a product of the reaction of a reaction mixture comprising: i. an isocyanate component comprising one or more polyisocyanates, and ii. an isocyanate-reactive component comprising: ii.1) a first polyether polyol having a molecular weight of at least 6000 g/mol hat is a reaction product of a starter molecule or a mixture of starter molecules having an OH functionality of 1.8-3.5 with ethylene oxide and propylene oxide, wherein the proportion of ethylene oxide, based on the total amount of ethylene oxide and propylene oxide, in the first polyether polyol is 10-28% by weight, ii.2) one or more polyester polyols having a functionality of greater than 2 and a hydroxyl number of 60-150 mg KOH/g, and that is a condensation reaction product of adipic acid with 1,2-propylene glycol and at least one further compound having at least two hydroxyl groups, ii.3) 1,4-butanediol, ii.4) diethylenetoluenediamine, ii.5) optionally further polyether polyols, ii.6) optionally chain extenders and/or crosslinking agents, ii.7) optionally catalysts, ii.8) optionally blowing agents, and ii.9) optionally auxiliaries and/or additives.

2. The composite element as claimed in claim 1, wherein the product of the reaction of the reaction mixture has a density of 155 kg/m3 or less, determined in accordance with the procedure indicated in the description.

3. The composite element as claimed in claim 1, wherein the proportion of ii.1) is 50-90% by weight and/or the proportion of ii.2) is 0.1-10% by weight and/or the proportion of ii.3) is 0.1-2.0% by weight and/or the proportion of ii.4) is 0.01-2.0% by weight, in each case based on the total amount of isocyanate-reactive component

4. The composite element as claimed in claim 1, wherein the first polyether polyol ii.1) has a molecular weight of 6000-10 000 g/mol.

5. The composite element as claimed in claim 1, wherein, for the first polyether polyol ii.1), the proportion of ethylene oxide, based on the total amount of ethylene oxide and propylene oxide, is 15-25% by weight.

6. The composite element as claimed in claim 1, wherein, for the first polyether polyol ii.1), the starter molecule is selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 4,4′-dihydroxydiphenylpropane, glycerol, trimethylolpropane, erythritol, sorbitol, ammonia, ethylene diamine, aniline, ethanolamine and triethanolamine, or a mixture thereof.

7. The composite element as claimed in claim 1, wherein, for the at least one polyester polyol ii.2), the at least one further compound having at least two hydroxyl groups is selected from the group consisting of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, or a mixture thereof.

8. The composite element as claimed in claim 1, wherein, for the at least one polyester polyol ii.2), the at least one further compound having at least two hydroxyl groups consists of 1,6-hexanediol and trimethylolpropane.

9. The composite element as claimed in claim 1, wherein the thermoplastic comprises one or more plastics from the group consisting of acrylonitrile-butadiene-styrene (ABS), polymethyl methacrylate (PMMA), acrylonitrile-styrene-acrylate (ASA), styrene-acrylonitrile (SAN), polycarbonate (PC), thermoplastic polyurethane (TPU), polyvinyl chloride (PVC), thermoplastic polyolefins (TPO) (optionally post-crosslinked), such as polyethylene and polypropylene, styrene-maleic anhydride copolymer (SMA), or a blend-thereof.

10. The composite element as claimed in claim 1, wherein the adhesion between the thermoplastic and the product of the reaction of the reaction mixture is at least 26 N/50 mm, measured in accordance with DIN 53 357 A as disclosed in the description.

11. A process for producing a composite element as claimed in claim 1, comprising: I. providing the thermoplastic, the isocyanate component, and the isocyanate-reactive component, II. mixing the isocyanate component and the isocyanate-reactive component provided in step I. in order to obtain the reaction mixture, III. bringing the reaction mixture obtained in step II. into contact with the thermoplastic provided in step I. so that the reaction mixture is in contact with the thermoplastic, IV. foaming the reaction mixture obtained in step II. while it is in contact with the thermoplastic, in order to obtain a composite element comprising the thermoplastic adjoined in adhering fashion by the product of the reaction of the reaction mixture, and V. demolding the composite element obtained in step IV.

12. (canceled)

13. A component in a vehicle construction, an aircraft construction, or a building construction comprising the composite element as claimed in claim 1.

Description

EXAMPLES

Measuring Instruments and Standards Used:

[0076] Determination of the hydroxyl number in accordance with DIN EN ISO 53240-2: Method with catalyst, November 2007 version [0077] Determination of the NCO content (Plastics—Polyurethane raw materials)—in accordance with DIN EN ISO 14896 of 2009 [0078] Determination of the foam density in accordance with DIN 53420 [0079] Determination of the separation force

[0080] The testing is carried out in accordance with the separation test according to DIN 53357. For this purpose, test specimens with a length of 170 mm and a width of 50 mm were produced. Testing velocity: 50 mm/min (the force is determined in accordance with DIN 53357 A; said force per composite element width represents the adhesion (rolling peel resistance)).

[0081] The values reported in Table 1 are reported in parts by weight, unless stated otherwise.

[0082] The materials and abbreviations used have the following meanings: [0083] PET A: Glycerol-started polyether polyol with 87% by weight of propylene oxide and 13% by weight of ethylene oxide end block having an OH number of 35 mg KOH/g and a nominal functionality of 3 [0084] PET B: Glycerol-started polyether polyol with 78% by weight of propylene oxide and 22% by weight of ethylene oxide end block having an OH number of 27.5 mg KOH/g and a nominal functionality of 3 [0085] PET C: Glycerol-started polyether polyol with 83% by weight of propylene oxide and 19% by weight of ethylene oxide end block having an OH number of 35 mg KOH/g and a nominal functionality of 3 [0086] PET D: Ethylenediamine-started polyether polyol with 100% by weight of propylene oxide, an OH number of 630 mg KOH/g and a nominal functionality of 4 [0087] SAN polyol: Glycerol-started polyether polyol with 80% by weight of propylene oxide and 20% by weight of ethylene oxide end block and a nominal functionality of 3 having a solids content of approx. 42% by weight of styrene-acrylonitrile copolymer and a hydroxyl number of approx. 20 mg KOH/g, from Covestro Deutschland AG [0088] Polyester polyol: Polyester polyol based on trimethylolpropane, 1,6-hexanediol, 1,2-propanediol and adipic acid having an OH number of 109 mg KOH/g and a nominal functionality of 3.23 [0089] Carbon black: ISOPUR® N black paste, from ISL-Chemie [0090] Chain extender 1: 1,4-Butanediol [0091] Chain extender 2: Diethyltoluenediamine [0092] Chain extender 3: Diethanolamine [0093] Stabilizer: TEGOSTAB® B8734 LF2, from Evonik, silicone-based [0094] Catalyst 1: N,N,N′-Trimethyl-N′-hydroxyethyl-bis(aminoethyl) ether, from Huntsman [0095] Catalyst 2: N[3-(Dimethylamino)propyl]urea, from Evonik [0096] Catalyst 3: Mixture of approx. 95% by weight of 6-dimethylaminohexanol and approx. 5% by weight of N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine, from Evonik [0097] Isocyanate A: Diphenylmethane diisocyanate mixture having an NCO content of 32% by weight of NCO, comprising 0.05-0.5% by weight of 2,2′-MDI, 5.5-7.5% by weight of 2,4′-MDI, 50-54% by weight of 4,4′-MDI and higher MDI homologs, from Covestro Deutschland AG [0098] Isocyanate B: Polyisocyanate based on diphenylmethane diisocyanate and a sorbitol-started polyether (polypropylene oxide having an OH number of 29 mg KOH/g and a nominal functionality of 6) having an NCO content of 26% by weight and a monomeric MDI content of 55-63% by weight, from Covestro Deutschland AG.

[0099] The film used was a skin produced by the slush process and based on DSY 260/02 PVC powder from Nakan.

TABLE-US-00001 TABLE 1 Comparative Comparative Parameter Example 1 example 2 example 3 PET A 0.0 75.01 30 PET B 73.6 0 0 PET C 0 0 50.4 PET D 0 0 2 SAN polyol 14.9 15 3.35 Polyester polyol 5 5 5 Water 2.6 2.6 2.1 Chain extender 2 1.4 0.5 0.95 Chain extender 1 0.9 0 0 Carbon black 0.5 0.5 0.5 Chain extender 3 0.0 0.23 0 Stabilizer 0 0.1 0 Catalyst 3 0.8 0.8 0 Catalyst 2 0 0 0.9 Catalyst 1 0.3 0.3 0.2 Isocyanate A 0 0 42.6 Isocyanate B 68.8 66.5 0 Separation force 30 25 15 between foam and PVC after 24 h [N/50 mm] Foam density [kg/m.sup.3] 125 130 150

Production of the Composite Elements

[0100] The composite elements were produced at a molding temperature of 45° C. in an aluminum mold with dimensions of 200×200×10 mm.sup.3 which was lined with a Teflon film and could be closed with a cover. A PVC film (200×200×1.1 mm.sup.3) was placed on the bottom of the mold. The constituents of the isocyanate-reactive component were first mixed in a 200 1 drum with a stirrer for approx. 1 h, with the result that 150 kg of a homogeneous polyol formulation (isocyanate-reactive component) was present. The high-pressure system was then filled with both components (isocyanate-reactive component and isocyanate component) and the temperature was set at 30° C. in each case.

[0101] Subsequently both components were mixed at a component pressure of 150 bar using a high-pressure mixing head. The reaction mixture resulting therefrom was applied to the open mold, and the latter was closed, with the amount of reaction mixture being chosen so as to result in an average density of the foam of 120 kg/m.sup.3. Demolding was performed after approx. 10 minutes and the composite element was stored at room temperature for 24 hours. Strips with a width of 50 mm were subsequently cut out. These strips were tested with respect to their adhesion properties (adhesion between PVC film and polyurethane).

[0102] It became clear from the experiments that the composite elements according to the invention with the polyether polyol according to the invention have significantly higher adhesion between thermoplastic and the polyisocyanate polyaddition product than the composite elements not according to the invention.