Non-primary hydroxyl group based foams

Abstract

Foamed pellets contain a thermoplastic polyurethane obtainable or obtained by a process. The process involves reacting a polyol composition (PZ-1) containing at least one hydroxy functionalized polyol (P1) with a maximum of 20% of primary hydroxyl groups with a polyisocyanate (I1), to obtain a polyol composition (PZ-2) containing a prepolymer (PP-1). The process then involves reacting the polyol composition (PZ-2) containing the prepolymer (PP-1) with a composition (C2) containing a chain extender (CE) with a molecular weight<500 g/mol. Foamed pellets are obtained or obtainable by the process. The foamed pellets can be used for the production of a molded body.

Claims

1-13. (canceled)

14. Foamed pellets, comprising a thermoplastic polyurethane obtained by a process comprising: reacting a polyol composition (PZ-1) comprising at least one hydroxy functionalized polyol (P1) with a maximum of 20% of primary hydroxyl groups with a polyisocyanate (I1), to obtain a polyol composition (PZ-2) containing a prepolymer (PP-1), (ii) reacting the polyol composition (PZ-2) containing the prepolymer (PP-1) with a composition (C2) comprising a chain extender (CE) with a molecular weight<500 g/mol, wherein a diameter of the foamed pellets is from 0.2 to 20 mm.

15. The foamed pellets according to claim 14, wherein the at least one hydroxy functionalized polyol (P1) contains more than 94% of non-primary hydroxyl groups.

16. The foamed pellets according to claim 14, wherein a number average molar mass Mn) of the at least one hydroxy functionalized polyol (P1) is in a range of from 500 to 2500 g/mol.

17. The foamed pellets according to claim 14, wherein the at least one hydroxy functionalized polyol (P1) is polypropylene glycol.

18. The foamed pellets according to claim 14, wherein the chain extender (CE) is selected from the group consisting of ethylene glycol, 1,3-propane diol, 1,4-butane diol, and 1,6-hexane diol.

19. The foamed pellets according to claim 14, wherein the foamed pellets further comprise at least one thermoplastic resin selected from the group consisting of polystyrene, high impact polystyrene, polyethylene, polypropylene, polyethylene terephthalate, a thermoplastic elastomer, and a mixture thereof.

20. A process for the production of foamed pellets, comprising: (i) reacting a polyol composition (PZ-1) comprising at least one hydroxy functionalized polyol (P1) with a maximum of 20% of primary hydroxyl groups with a polyisocyanate (I1), to obtain a polyol composition (PZ-2) containing a prepolymer (PP-1), (ii) reacting the polyol composition (PZ-2) containing the prepolymer (PP-1) with a composition (C2) comprising a chain extender (CE) with a molecular weight<500 g/mol, wherein a diameter of the foamed pellets is from 0.2 to 20 mm.

21. A method, comprising: producing a molded body with the foamed pellets according to claim 14.

22. The method according to claim 21, wherein the molded body is produced by fusion or bonding of the foamed pellets to one another.

23. The method according to claim 21, wherein the molded body is a shoe sole, part of a shoe sole, shoe intermediate sole, shoe insole, shoe combisole, a bicycle saddle, a bicycle tire, a damping element, cushioning, a mattress, an underlay, a grip, a protective film, or a component in automobile interiors and exteriors.

24. An article, comprising the foamed pellets according to claim 14, wherein the article is selected from the group consisting of a ball, sports equipment, floor covering, and wall paneling.

25. A hybrid material, comprising a matrix composed of a polymer (PM) and the foamed pellets according to claim 14.

26. The article according to claim 24, wherein the article is selected from the group consisting of a sports surface, a track and field surface, a sports hall, a shock pad, a children's playground, and a pathway.

Description

EXAMPLES

[0238] 1. Evaluations and Measurement Methods

TABLE-US-00001 Melt Flow Rate (MFR) DIN EN ISO 1133: 2012-03 Tensile strength DIN 53504: 2009-10 Elongation at break DIN 53504: 2009-10 Bulk Density (BD) DIN ISO 697: 1984-01 S2- Bodies DIN 53504: 2009-10 [0239] 2. Materials used [0240] Polyol 1 (PPG-1000): Polypropylene glycol with a hydroxyl number of 104 mg/KOH/g having predominantly secondary hydroxyl groups. [0241] Polyol 2 (PPG-EO): Poly(propylene-b-ethylene) glycol with a hydroxyl number of 63 mg KOH/g having a mixture of secondary and primary hydroxyl groups. [0242] Isocyanate: 4,4′-Methylene diphenyl diisocyanate [0243] Chain extender: 1,4-Butane diol [0244] Catalyst: Tin-II-isooctoate (50% in dioctyladipate) [0245] Surfactant 1: Calciumcarbonat (CaCO.sub.3) [0246] Surfactant 2: Ethoxylated (25 EO) C16C18-Fatty alcohol [0247] 3. Examples—Preparation of prepolymers [0248] 3.1 Pre-polymer (TPU-1)

[0249] A prepolymer was prepared using 4,4′-methylene diphenyl diisocyanate, tin-II-isooctoate as a catalyst and a polyetherol as indicated in table 1 in an adiabatic continuous reactor with a residence time of about 10 minutes. The components were premixed before addition to the reactor and heated to a temperature of 100° C. to 120° C. After the adiabatic continuous reactor unit, the prepolymer is cooled down to a temperature of 60° C. to 90° C. By addition of the chain extender 1,4-butanediol which was heated to 60° C. prior to the addition and further temperature adjustment to a temperature of 110 to 180° C. of the reaction mixture on a beltline with a residence tome of 5 to 10 minutes, the thermoplastic polyurethane was obtained.

[0250] The thermoplastic polyurethane obtained was granulated and 2 mm bodies were prepared by injection molding. The S2-bodies (according to DIN 53504:2009-10) were tested. The mechanical properties are summarized in table 2.

[0251] The maximum temperature of the melt was 240° C. [0252] 3.2 One-shot (TPU-2, TPU-3. TPU-4)

[0253] A thermoplastic polyurethane was prepared using 4,4′-methylene diphenyl diisocyanate, the chain extender 1,4-butanediol, tin-II-isooctoate as a catalyst and a polyetherol as indicated in table 1 in a reactor. After a reaction temperature of 110° C. was reached, the reaction mixture was added on a beltline with a residence time of 5 to 10 minutes, the thermoplastic polyurethane was obtained.

[0254] The thermoplastic polyurethane obtained was tempered for 15 h at 80° C. and was subsequently granulated. 2 mm bodies were prepared by injection molding from the granules. The S2-bodies obtained (according to DIN 53504, 2009-10) were tested. The mechanical properties are summarized in table 2.

[0255] The maximum temperature of the melt in the preparation process was 240° C.

TABLE-US-00002 TABLE 1 Composition of tested TPUs TPU No. TPU-1 TPU-2 TPU-3 TPU-4 Pre-Polymer One-shot one-shot One-shot Polyol 1 1000 g 1000 g 1000 g — Polyol 2 — — — 1000 g Isocyanate 621.11 g 515.52 g 515.52 g 630 g Chain Extender 139.79 g 130.76 g 130.76 g 174.67 g Catalyst 44 μL 41 μL 412 μL 44 μL Index 1000 1025 1025 1040

[0256] The mechanical properties of the materials obtained are summarized in table 2. For TPU-2 and TPU-3, no formed bodies could be obtained from the materials. It was not possible to determine the mechanical properties of the materials.

TABLE-US-00003 TABLE 2 Mechanical properties of TPUs Trial No. TPU-1 TPU-2 TPU-3 TPU-4 Pre-Polymer One-shot One-shot One-shot PPG PPG PPG PPG PPG-EO Mn1000 Mn 1000 Mn 1000 Mn1000 g/mol g/mol g/mol g/mol Index 1000 1000 1000 1040 Shore A 80 A n.d. n.d. 89 A Tensile strength 17 MPa n.d. n.d. 43 MPa Elongation @ 690% n.d. n.d. 660% break Mw Lsg 10 80 kDa n.d. 32 kDa 72 kDa [0257] 4. Expanded Beads [0258] 4.1 Extrusion Process—eTPU-1, eTPU-2, eTPU-4

[0259] For TPU-1 and TPU-4, the expanding process was conducted in a twin-screw extruder of company Coperion (ZSK 40). The material was dried for minimum 5 h at 70° C. directly before extrusion. During processing 0.1% of nucleating agent (particle size 5.6 μm—D50, distribution of volume) and if necessary different amounts of a TPU which was com-pounded in a separate extrusion process with 4,4-Diphenylmethandiisocyanat and poly-meric Diphenylmethandiisocyanat with a functionality of 2,05 (additive 1) or 2,4 (additive 2) was added. The temperature range of the extruder was 190° C. As blowing agent CO.sub.2 and N.sub.2 was injected into the melt and all added materials were mixed homogeneously with the thermoplastic polyurethane. Table 3 shows the different compositions of eTPU-1, eTPU-2 and eTPU-4.

[0260] After mixing of all components in the extruder the material was first pressed through a gear pump with a temperature of 170° C. and then through a die plate heated up to 140° C. The granulate was cut and formed in the underwater pelletizing system (UWP). During the transport out of the UWP the particles expands under defined conditions of temperature and pressure of the water. Before drying the material for 5 h at 50° C. a centrifugal drier was used for separating the granulate and the water.

[0261] Process details of all examples such as the used water temperatures and-pressure, amount of blowing agents CO.sub.2 and N.sub.2 as well as the particle mass and resulting bulk density are listed in table 3.

TABLE-US-00004 TABLE 3 Process details of eTPU extrusion-processing step eTPU eTPU-4 eTPU-1 eTPU-2 (Reference) TPU TPU-1 TPU-1 TPU-4 Content of TPU (% b.w.) 99.4 99.4 99.9 Content of nucleating agent (wt %) 0.1 0.1 0.1 Content of additive 1 (wt %) 0.5 — — Content of additive 2 (wt %) — 0.5 — Part.-Mas. (mg) 22 22 22 Bulk Density (g/L) 147 127 g/L 180 CO.sub.2 (wt %) 1.2 1.2 1.7 N.sub.2 (wt %) 0.21 0.21 0 Pressure in UWP (bar) 10.0 8.4 9.3 Temperature in UWP(° C.) 34 33 49 [0262] 4.2 Autoclave Process—eTPU-3

[0263] For the examples, the inventive TPU-1 was used. Experiments are conducted in a closed pressure vessel (Impregnation vessel) at a filling level of 80% by volume.

[0264] 100 parts by weight of particles from TPU-1 and a defined volume of water as suspension medium which results in a phase relationship P1 are mixed by stirring to get a homoge-nous suspension. Phase relationship P1 is defined as volume of solid particles divided by volume of water. 6.7% by weight, based on the solid particles, of a dispersing agent (surfactant 1), together with 0.13% by weight of an assistant system (surfactant 2), based on the solid particles, and a certain amount of butane as blowing agent, based on the solid particles, are added to the suspension and heated up during further stirring.

[0265] At 50° C., nitrogen as co-blowing agent was added by pressure increase, to a predetermined pressure within the vessel. The liquid phase of the suspension was heated to the predetermined impregnation temperature (IMT). The time (soaking time) between 5° C. below IMT until IMT is controlled to be within 3 min and 60 min. This correlates with a heating rate of 1.67° C./min until 0.083° C./min.

[0266] In this procedure, at IMT a defined pressure in gaseous phase (IMP) is formed.

[0267] After soaking time and at the reached IMT, the pressure was released and the whole content of the vessel (suspension) was poured through a relaxation device into a vessel under atmospheric pressure (expansion vessel). Expanded beads are formed.

[0268] During the relaxation step, the pressure within the impregnation vessel was fixed with nitrogen to a certain level (squeezing pressure SP).

[0269] Additionally, directly after the relaxation device, the expanding particles can by cooled by a certain flow of water with a certain temperature (water quench).

[0270] After removal of the dispersing agent and/or the assistant system (surfactant) and subsequent drying, the bulk density of the resulting foamed beads is measured (according to DIN ISO 697: 1984-01).

[0271] Details concerning manufacturing parameters are listed in table 4.

TABLE-US-00005 TABLE 4 Data for the manufacturing expanded beads eTPU eTPU-3 TPU TPU-1 Dispersing agent Surfactant 1 Assistant system Surfactant 2 Phase relationship P1 0.14 Butane (wt %) 24 p after adding N.sub.2 at 50° C. (bar) 8 Soaking time (min) 4 IMT (° C.) 116 SP (MPa) 4.0 Water quench No Bulk density (kg/m.sup.3) 115 [0272] 5. Steam Chest Molding & Mechanics

[0273] In a next step the expanded material was molded to quadratic test plates with a length of 200 mm×200 mm and thickness of 10 mm and 20 mm respectively using steam chest molding machine of company Kurtz ersa GmbH (Boost Foamer K68). The molding pa-rameter were identical, independent of thickness of test plates. Additionally, the crack steam was carried out by the movable side of the tool. The molding parameters are listed in table 5.

TABLE-US-00006 TABLE 5 Processing conditions for steam chest molding of examples Example eTPU-4 eTPU-1 eTPU-2 eTPU-3 (Reference) Crack size (mm) 14/22 14/22 14/22 14/22 Crack steam fixed — — — — side (bar) Crack steam fixed — — — — side (s) Crack steam movable    0.75    0.75    0.75    0.75 side (bar) Crack steam movable 18 18 18 18 side (s) Cross steam fixed 1.3/1.1 1.3/1.1 1.3/1.1 1.3/1.1 side/counter pressure (bar) Cross steam fixed 40/20 40/20 40/20 40/20 side/counter pressure (s) Cross steam movable — — — — side/counter pressure (bar) Cross steam — — — — movable side/counter pressure (s) Autoclave steam 1.3/0.8 1.3/0.8 1.3/0.8 1.3/0.8 fixed/movable side (bar) Autoclave steam (s) 10 10 10 10

[0274] The results of mechanical testing are listed in Table 6. Part density, tensile strength, elongation at break, and compression hardness are measured according to the following test methods:

[0275] Tensile strength and elongation at break are measured with a universal testing machine, which is equipped with a 2.5 kN force sensor (class 0,5 (ab 10N), DIN EN ISO 7500-1, 2018), a long-stroke-extensometer (class 1 after DIN EN ISO 9513, 2013) and pneumatic clamps (6 bar, clamping jaws out of pyramid grid (Zwick T600R)).

[0276] The specimens (150 mm×25.4 mm×thickness of the test plate) are culled from a 200×200×10 mm test plate (dimensions could vary slightly due to shrinkage) with a cutting die. Before, the test plates were stored for at least 16 h under standardized climate conditions (23±2° C. and 50±5% humidity). The measurement is also carried out in standard climate. For each specimen density is determined. Therefore, mass (precision scale; accuracy: ±0,001 g) and thickness (caliper; accuracy: ±0.01 mm, contact pressure 100 Pa, value is only measured once in the middle of the specimen) are measured. Length (150 mm) and width (25.4 mm) are known from the dimension of the cutting die.

[0277] The L.sub.E-position (75 mm) and the distance of the long-stroke-extensometer d (50 mm) are checked before stating the measurement. The specimen is placed on the upper clamp and the force is tared. Then the specimen is clamped and measurement could be started. The measurement is carried out with a testing speed of 100 mm/min and a force of 1 N. The calculation of tensile strength σ.sub.max (specified in M Pa) is done by equation (1), which is the maximum tension. This tension can be identical to the tension at breakage. Elongation at break ε (specified in %) is calculated using equation (2). Three specimens are tested for each material. The mean value from the three measurements is given. If the test specimen tears outside the selected area, this is noted. A repetition with another test specimen is not performed.

[00001]$\begin{array}{cc}{\sigma }_{\max }=\frac{F_{\max }}{d.Math.h}& \left(1\right)\end{array}$ [0278] σ.sub.max=Tensile strength [0279] F.sub.max=Maximum tention [N] [0280] D=Thickness of the specimen [mm] [0281] B=Width of the specimen [mm]

[00002]$\begin{array}{cc}\epsilon =\frac{L_B-L_0}{L_0}.Math.100\%& \left(2\right)\end{array}$ [0282] ε=Eolongation at break [0283] L.sub.B=Length at breakage [mm] [0284] L.sub.0=Length before starting measurement [mm]

TABLE-US-00007 TABLE 6 Mechanical properties of molded examples Tensile Tensile Part Density Strength Compression elongation (10 & 20 mm) (10 mm) hardness 50% (10 mm) (g/cm.sup.3) (MPa) (20 mm)/(kPa) (%) eTPU-1 0.307/0.265 0.33 229 72 eTPU-2 0.272/0.236 0.56 195 80 eTPU-3 0.302/0.264 0.28 227 63 eTPU-4 0.380/0.367 0.10 666 10 (Reference)

LITERATURE CITED

[0285] WO 94/20568 Al [0286] WO 2007/082838 A1 [0287] WO 2017/030835 A1 [0288] WO 201 3/1 531 90 Al [0289] WO 201 0/01 001 0 Al [0290] WO 02/064656 A2 [0291] WO 93/24549 Al [0292] US 2006/0258831 A1 [0293] EP 1746117 A1 [0294] “Plastics Handbook, Volume 7, Polyurethanes”, Carl Hanser Verlag, 3rd Edition 1993, Chapter 3.1 and chapter 7 [0295] EP 0571 831 Al [0296] DE 1 962 5987 Al [0297] EP 1 031 588 B1 [0298] EP 1 213 307 B1 [0299] EP 1 338 614 B1 [0300] Kunststoff-Taschenbuch [Plastics Handbook], 27th edition, Hanser-Verlag, Munich 1998, chapters 3.2.1 and 3.2.4 [0301] WO 2014/150122 A1 [0302] WO 2014/150124 A1 [0303] EP 1979401 B1 [0304] US 2015/0337102 [0305] EP 2872309 B1 [0306] EP 3053732 A1 [0307] WO 2016/146537 A1 [0308] “Integralschaumstoff” [Integral Foam], Carl-Hanser-Verlag, Munich, Vienna, 1975