Patent ID: 12234338

EXAMPLES

Test Methods:

The following test methods and parameters were used, inter alia, to characterize the raw materials used and also the resulting foam particles and moldings:

Melting Point Determination by Means of DSC:

Procedure in accordance with ISO 11357-3 (German version of Apr. 1, 2013) using a DSC Q100 from TA Instruments. To determine the melting point of the thermoplastic elastomers used or of other thermoplastic elastomers according to the invention in pellet form, 3-5 mg are heated at a heating rate of 20° C./min in a 1strun between 20° C. and 200° C., subsequently cooled at 10° C./min to 20° C., followed by a further heating cycle (2ndrun) at a heating rate of 10° C./min. The temperature of the peak maximum in the 2ndrun was reported as melting point.

Crystalline Structure by DSC:

To characterize the crystalline structure of the compact thermoplastic elastomer or the expanded foam particles, 3-5 mg are heated at a heating rate of 20° C./min between 20° C. and 200° C. and the resulting heat flow is determined.

Bulk Density:

The determination was carried out by a method based on DIN EN ISO 60: 2000-1. Here, the foam particles were introduced into a measuring cylinder having a known volume with the aid of a funnel having a predetermined geometry (completely filled with bulk material), the excess of the bulk material was struck off from the measuring cylinder by means of a straight-edged bar and the contents of the measuring cylinder were determined by weighing.

The funnel used has a height of 40 cm, an opening angle of 35° C. and an outlet having a diameter of 50 mm. The measuring cylinder had an internal diameter of 188 mm and a volume of 10 l.

The bulk density (BD) is given by the mass of the bed [kg]/0.01 [m3].

The average of 3 measurements in kg/m3was reported as bulk density.

Degree of Compaction DC

The degree of compaction DC is the ratio of density of the molding (M density) to bulk density (BD). DC=M density [kg/m3]/BD [kg/m3].

Hot Storage

The test specimens (180×60×M density mm) were placed in an oven which had been preheated to the appropriate storage temperature (110° C.) and stored at this temperature for 96 hours.

Assessment of the Surfaces/Edges as Follows:

The surface and edge of the test specimens was assessed every 24 hours during the storage time according to a scale of grades. For this purpose, the test specimens were briefly taken from the oven.

EvaluationGradeNo change1Abrasion at edge2Disintegration of edge3Disintegration of the edge4plus 0 to 5 mm deepdamage to the surfaceDisintegration of the edge5plus 5 to 10 mm deepdamage to the surfaceSample disintegrates under6gentle thumb pressure

After the end of the hot storage, the test specimens were carefully taken from the oven, stored at room temperature for 24 hours under room conditions and the change in dimensions was subsequently measured by means of the sliding caliber.

The change in dimensions (length, width, height) is calculated according to the following formula:
CD=[(Lo−L1)/Lo)]×100CD=change in dimension in %Lo=original dimensionL1=dimension after hot storage

The heat resistance was satisfactory (OK) when surfaces and edges did not display any changes and the average change in dimensions over length, width and height was <10%. It is limited when this change in dimensions is achieved only in the case of storage at lower temperatures.

Starting Materials

A TPA-EE, i.e. a polyether block amide (PEBA), was used as thermoplastic polyamide elastomer (TPA) in the examples according to the invention. Such products are supplied, for example, by Arkema Speciality Polyamides under the tradename PEBAX. The products listed in table 1 consist of flexible polytetrahydrofuran and crystalline polyamide units (PA-12).

TABLE 1thermoplastic polyamide elastomers used2533353340337233PebaxSA 01SA 01SA 01SA 01Density [g/cm3]ISO 11831.001.001.001.01Melting point [° C.]ISO 11357134144160174Vicat temperature (at 1ISO 3065877131164daN) [° C.]Hardness [Shore A/ISO 86877/2782/3390/42-/69Shore D]Characterization by described methodsPellets, particle weights18212117[mg]Pellets, bulk density602589614588[kg/m3]DSC Tmax (1strun) [° C.]70/14278/149-/164-/171Elemental analysis (EA) N1.41.83.46.6[%]Proportion of PA block19.825.448.093.1[%] by weight] (calculatedfrom N from EA)
Production of the Expanded Thermoplastic Elastomer

General Experimental Description

Pellets having a particle weight of about 19 mg, whose composition is described in table 1, were used.

Examples 1-4 and 6-13

The experiments were carried out with a degree of fill of the vessel of 80% and a phase ratio of 0.41.

100 parts by weight (corresponding to 28.5% by weight, based on the total suspension without blowing agent) of the pellets, 245 parts by weight (corresponding to 69.6% by weight, based on the total suspension without blowing agent) of water, 6.7 parts by weight (corresponding to 1.9% by weight, based on the total suspension without blowing agent) of calcium carbonate, 0.13 part by weight (corresponding to 0.04% by weight, based on the total suspension without blowing agent) of a surface-active substance (Lutensol AT 25) and the appropriate amount of butane as blowing agent (based on the amount of pellets used) were heated while stirring. Nitrogen was then additionally injected at a temperature of the liquid phase of 50° C. and the internal pressure was set to a previously defined pressure (800 kPa). Depressurization is subsequently carried out via a depressurization apparatus after attainment of the impregnation temperature (IMT) and optionally after a hold time (HT) and at the impregnation pressure (IMP) set at the end. The gas space is here brought to a predetermined expression pressure and kept constant during the depressurization. The depressurization jet can optionally be cooled by means of a particular volume flow of water having a particular temperature (water quench) downstream of the depressurization apparatus. In examples 1-4 and 10, cooling was carried out using an amount of water at 25° C. which corresponds to the ratio (mass of quenching water)/(mass of suspension medium)=0.85.

After removal of the suspension aid (dispersant and soap) and drying, the bulk density (BD) of the resulting particles is measured.

Example 5

As for examples 1-4, but 12% by weight of CO2are used instead of butane as blowing agent and no additional nitrogen is injected.

Example 14

The experiment was carried out with a degree of fill of the vessel of 70% and a phase ratio of 0.27.

100 parts by weight (corresponding to 21.2% by weight, based on the total suspension without blowing agent) of the pellets, 365 parts by weight (corresponding to 77.4% by weight, based on the total suspension without blowing agent) of water, 6.7 parts by weight (corresponding to 1.4% by weight, based on the total suspension without blowing agent) of calcium carbonate, 0.14 part by weight (corresponding to 0.03% by weight, based on the total suspension without blowing agent) of a surface-active substance (Lutensol AT 25) and the appropriate amount of butane as blowing agent (based on the amount of pellets used) were heated while stirring. No additional injection of nitrogen was carried out at 50° C. Depressurization is subsequently carried out via a depressurization apparatus after attainment of the impregnation temperature (IMT) and optionally after a hold time (HT) and at the impregnation pressure (IMP) set at the end. The gas space is here brought to a predetermined expression pressure (3700 kPa) and kept constant during the depressurization.

After removal of the suspension aid (dispersant and soap) and drying, the bulk density (BD) of the resulting foam particles is measured.

Examples 15 and 16

The experiments were carried out with a degree of fill of the vessel of 80% and a phase ratio of 0.31.

100 parts by weight (corresponding to 23.4% by weight, based on the total suspension without blowing agent) of the pellets, 320 parts by weight (corresponding to 75.0% by weight, based on the total suspension without blowing agent) of water, 6.7 parts by weight (corresponding to 1.6% by weight, based on the total suspension without blowing agent) of calcium carbonate, 0.13 part by weight (corresponding to 0.03% by weight, based on the total suspension without blowing agent) of a surface-active substance (Lutensol AT 25) and the appropriate amount of butane as blowing agent (based on the amount of pellets used) were heated while stirring.

In the case of example 15, no additional nitrogen is injected. In the case of example 16, nitrogen was additionally injected and the internal pressure set to a previously defined pressure (800 kPa) at a temperature of the liquid phase of 50° C.

The further course of the experiment is as in example 14.

The experimental parameters (blowing agent, amount of blowing agent, impregnation temperature (IMT), impregnation pressure (IMP), expression pressure) and the resulting bulk density (BD) for examples 1 to 16 according to the invention are reported in table 2.

The phase ratio is defined as the ratio of pellets, measured in kilograms, to suspension medium, which is preferably water, likewise in kilograms.

The hold time (HT) is defined as the time [min] for which the temperature of the liquid phase is in a temperature range from 5° C. below the IMT to 2° C. above the IMT.

Production of the Moldings:

The production of the moldings was carried out on a commercial automatic EPP molding machine (model K68 from Kurtz GmbH). Cuboidal test specimens having different thicknesses were produced using tools having the dimensions 315×210×25 mm and 315*210*20 mm. The moldings were produced by the pressure filling process or the crack filling process. After production of the moldings, the moldings were stored at 60° C. for 16 hours.

The results of the subsequent tests on the moldings are reported in table 3.

TABLE 2Experimental parameters for examples 1 to 16T [° C.]Blowingof theBulkagentsuspensionHoldExpressiondensityBlowingcontentsat N2IMTtimeIMPpressureWaterBDExampleType of pelletsagent[% by weight]introduction[° C.][min][kPa][kPa]quench[kg/m3]Example 1Pebax 2533 SA 01Butane24.050100.0219703400yes94Example 2Pebax 2533 SA 01Butane24.05095.0218303400yes141Example 3Pebax 2533 SA 01Butane24.05090.01516703400yes213Example 4Pebax 2533 SA 01Butane24.05095.01318003400yes104Example 5Pebax 2533 SA 01CO212.0—100.01130103700yes215Example 6Pebax 3533 SA 01Butane24.050100.0418103400no206Example 7Pebax 3533 SA 01Butane24.050103.02019603400no136Example 8Pebax 3533 SA 01Butane24.050105.51720203400no107Example 9Pebax 3533 SA 01Butane24.050106.51520303400no92Example 10Pebax 3533 SA 01Butane24.050106.51720203400yes131Example 11Pebax 4033 SA 01Butane24.050132.0327503700no81Example 12Pebax 4033 SA 01Butane24.050135.0327803700no40Example 13Pebax 4033 SA 01Butane24.050130.0328803700no113Example 14Pebax 7233 SA 01Butane24.0—156.0323503700no84Example 15Pebax 7233 SA 01Butane24.0—156.0329603700no36Example 16Pebax 7233 SA 01Butane24.050152.0335303700no48

TABLE 3Tests on moldings produced from foam particles from examples 1 to 16Density of theTensileCompressiveElongationReboundmoldingstressstressat breakresilience[kg/m3][kPa][kPa][%][%]DIN EN ISODIN EN ISODIN EN ISO 844DIN EN ISODIN EN ISOFoam8451798(Nov. 1, 2014)17988307particles(Oct. 1,(Apr. 1,at 50%(Apr. 1,(Jan. 1,Molding(table 2)DC2009)2008)compression2008)2008)Heat resistanceM-1Example 12.12004001657569n.d.M-2Example 21.82604503007568limited(OK at 90° C.)M-4Example 42.02102501655573n.d.M-5Example 52.041098065013866n.d.M-7Example 72.12804903805675OK (CD < 10%)M-8Example 82.02152002502675n.d.M-9Example 92.42204502605873OK (CD < 10%)M-10Example 102.12804803905574OK (CD < 10%)M-11Example 111.91505303603565OK (CD < 1%)M-12Example 122.4953501704564n.d.M-13Example 131.71904905003561OK (CD < 1%)M-16Example 164.01602004502045OK (CD < 1%)n.d. not determinedM-5 and M-16 were produced by the crack filling process.