POLYBUTYLENE TEREPHTHALATE THERMOFORMING PROCESS

Abstract

The invention relates to the use of a thermoplastic polymer having a melting point below 220° C. as additive in polybutylene terephthalate molding compositions for reducing the necking upon elongation of sheets or films of the polybutylene terephthalate molding composition, preferably wherein the polybutylene terephthalate molding composition comprises a) 50 to 95 wt % of polybutylene terephthalate as component A, b) 5 to 50 wt % of the thermoplastic polymer having a melting point below 220° C., as component B, c) 0 to 45 wt % of filler as component C, d) 0 to 20 wt % of further additives as component D, wherein the total of components A to D is 100 wt %.

Claims

1. (canceled)

2. The method according to claim 15, wherein an amount of the thermoplastic polymer having a melting point below 220° C. is 5 to 40 wt %, based on the total amount of the polybutylene terephthalate molding composition, which is 100 wt %.

3. The method according to claim 15, wherein the polybutylene terephthalate molding composition comprises a) 50 to 95 wt % of polybutylene terephthalate as component A, b) 5 to 50 wt % of the thermoplastic polymer having a melting point below 220° C., as component B, c) 0 to 45 wt % of filler as component C, d) 0 to 20 wt % of further additives as component D, wherein the total of components A to D is 100 wt %.

4. The method according to claim 3, wherein the polybutylene terephthalate molding composition comprises 50 to 94.9 wt % of component A, and component D comprises 0.1 to 2 wt % of a copolymer containing epoxy groups and based on styrene, acrylate and/or methacrylate, of a bisphenol A epoxide, or of a fatty acid amide of fatty acid ester or natural oil containing epoxy groups, or mixtures thereof, each based on the total of compounds A to D which is 100 wt %.

5. The method according to claim 4, wherein component D comprises 0.1 to 2 wt % of styrene-acrylic acid-glycidyl methacrylate copolymer, based on the total of components A to D which is 100 wt %.

6. The method according to claim 3, wherein 50 to 90 wt % of component A and 5 to 30 wt % of component C are present in the molding composition.

7. The method according to claim 3, wherein a semiaromatic polyester for component B is a polyester which comprises the following significant components: BA) an acid component composed of a1) from 30 to 99 mol % of at least one aliphatic, or at least one cycloaliphatic, dicarboxylic acid, or its ester-forming derivatives, or a mixture of these, a2) from 1 to 70 mol % of at least one aromatic dicarboxylic acid, or its ester-forming derivative, or a mixture of these, and a3) from 0 to 5 mol % of a compound comprising sulfonate groups, BB) a diol component selected from at least one C.sub.2-C.sub.12 alkanediol and at least one C.sub.5-C.sub.10 cycloalkanediol, or a mixture of these, and, if desired, also one or more components selected from BC) a component selected from the group consisting of c1) at least one dihydroxy compound comprising ether functions and having the formula I
HO—[(CH.sub.2).sub.n—O].sub.m—H  (I) where n is 2, 3 or 4 and m is a whole number from 2 to 250, c2) at least one hydroxycarboxylic acid of the formula IIa or IIb ##STR00005## where p is a whole number from 1 to 1500 and r is a whole number from 1 to 4, and G is a radical selected from the group consisting of phenylene, —(CH.sub.2).sub.q— where q is a whole number from 1 to 5, —C(R)H— and —C(R)HCH.sub.2, where R is methyl or ethyl, c3) at least one amino-C.sub.2-C.sub.12 alkanol, or at least one amino-C.sub.5-C.sub.10 cycloalkanol, or a mixture of these, c4) at least one diamino-C.sub.1-C.sub.8 alkane, c5) at least one 2,2′-bisoxazoline of the formula III ##STR00006## where R.sup.1 is a single bond, a (CH.sub.2).sub.z-alkylene group, where z is 2, 3 or 4, or a phenylene group c6) at least one aminocarboxylic acid selected from the group consisting of the naturally occurring amino acids, polyamides obtainable by polycondensing a dicarboxylic acid having from 4 to 6 carbon atoms with a diamine having from 4 to 10 carbon atoms, compounds of the formulae IVa and IVb ##STR00007## where s is an integer from 1 to 1500 and t is a whole number from 1 to 4, and T is a radical selected from the group consisting of phenylene, —(CH.sub.2).sub.u—, where u is a whole number from 1 to 12, —C(R.sup.2)H— and —C(R.sup.2)HCH.sub.2—, where R.sup.2 is methyl or ethyl, and polyoxazolines having the repeat unit V ##STR00008## where R.sup.3 is hydrogen, C.sub.1-C.sub.6-alkyl, C.sub.5-C.sub.8-cycloalkyl, phenyl, either unsubstituted or with up to three C.sub.1-C.sub.4-alkyl substituents, or tetrahydrofuryl, or a mixture composed of c1 to c6, and BD) a component selected from d1) at least one compound having at least three groups capable of ester formation, d2) at least one isocyanate, d3) at least one divinyl ether, or a mixture composed of d1) to d3).

8. The method according to claim 7, wherein semiaromatic polyesters for component B are based on the following components: BA, BB, di BA, BB, d2 BA, BB, di, d2 BA, BB, d3 BA, BB, c1 BA, BB, c1, d3 BA, BB, c3, c4 BA, BB, c3, c4, c5 BA, BB, d1, c3, c5 BA, BB, c3, d3 BA, BB, c3, di BA, BB, c1, c3, d3 BA, BB, c2.

9. A process for manufacturing moldings containing or made of a polybutylene terephthalate molding composition as defined in claim 3 by heating a sheet or film containing or made of the polybutylene terephthalate molding composition to a pliable forming temperature and thermoforming the heated sheet of film to a desired shape in a mold, cooling the shaped molding so that it solidifies and optionally trimming the shaped molding, wherein the polybutylene terephthalate molding composition is free from copolyetherester-elastomers.

10. The process of claim 9, wherein the sheet made of the polybutylene terephthalate molding composition is heated to a temperature in the range of from 170 to 220° C.

11. A polybutylene terephthalate molding composition as defined in claim 3, wherein the amount of the thermoplastic polymer having a melting point below 220° C. is 15 to 25 wt %, based on the total amount of the polybutylene terephthalate molding composition, which is 100 wt % and wherein the polybutylene terephthalate molding composition is free from copolyetherester-elastomers.

12. The polybutylene terephthalate molding composition of claim 11, which comprises less than 15 wt %, based on the polybutylene terephthalate molding composition, of biodegradable homo- or copolyesters, selected from the group consisting of polylactide, polycaprolactone, polyhydroxyalkanoates and polyesters composed of aliphatic dicarboxylic acids and of aliphatic diols.

13. The polybutylene terephthalate molding composition of claim 11 which does not contain polymers containing acrylic acid and/or styrene containing recurring units other than styrene-acrylic acid-glycidyl methacrylate copolymers.

14. A thermoformed molding of a polybutylene terephthalate molding composition of claim 11.

15. A method for reducing necking upon elongation of a sheet or a film molding composition in a thermoforming process comprising adding a thermoplastic polymer having a melting point below 220° C., where the thermoplastic polymer is selected from the group consisting of polyesters based on an aliphatic and aromatic dicarboxylic acid and on an aliphatic dihydroxy compound.

Description

EXAMPLES

[0166] Differential Scanning calorimetry (DSC) is performed at 20 K/min according to ISO 11357-1. Glass transition temperatures are determined according to ISO 11357-2 and melting points according to ISO 11357-3, respectively.

[0167] Materials

[0168] Poly(butylene terephthalate) (PBT): Ultradur® B6550 of BASF SE, melting point: 223° C.;

[0169] Poly(butylene adipate terephthalate) (PBAT): Ecoflex® F. Blend C1200 of BASF SE, melting point: 110 to 115° C.;

[0170] Thermoplastic elastomer (TPEE): Hytrel® 4056 of DuPont, melting point: 152° C.;

[0171] Acrylic ester, styrene acrylonitrile (ASA): Luran® 358N of INEOS Styrolution, melting point: 111° C.;

[0172] Poly(lactic acid) (PLA): Ingeo® PLA 4044 of NatureWorks, melting point: 153° C.;

[0173] Poly(keton) (PK): Akrotek® PK-VM of AKRO Plastic, melting point: 220° C.;

[0174] Poly(ethylene) (HDPE): Lupolen® 4261AG of LyondellBasell, melting point: 131° C.;

[0175] Poly(ethylene) (LDPE): Lupolen® 2420F of LyondellBasell, melting point: 111° C.;

[0176] Polyamide-6.6: Ultramid® A 24E of BASF SE, melting point: 263° C.

Preparation of the Example V1

[0177] Ultradur® B6550 was mixed with Hytrel® 4056 in a twin-screw extruder (ZE40AUTXi) at 275° C. melt temperature. After extrusion, the strands were cooled with water and cut into granulates. Drying of the sample was done at 100° C. for four hours. The samples were injection molded using an Arburg 470 at 260° C. with a molding time of 5 to 10 seconds. This process yielded tensile bars with a thickness of 4.0 mm (details in FIG. 3).

[0178] Examples V2 to V6 and C1 were prepared using the same method.

[0179] FIG. 3 shows the dimensions of the tensile bar in mm.

[0180] Testing

[0181] Tensile testing was done according to ISO 527-2:2012 at 50 mm/min at different temperatures from 23° C. to 230° C.

TABLE-US-00001 TABLE 1 Composition of the Examples V1 to V6 and Comparative Examples C1 to C3, all in wt % V1 V2 V3 C2 C3 V4 V5 V6 C1 Ultradur ® B6550 80 80 80 80 80 80 80 80 100 Hytrel ® 4056 20 Luran ® 358N 20 Ingeo ® PLA4044 20 Akrotek ® PK-VM 20 Ultramid ® A24E 20 Lupolen ® 4261AG 20 Lupolen ® 2420F 20 ecoflex ® F Blend C1200 20

[0182] Examples of a sliding curve are shown in the enclosed FIG. 1 (Example C1) and FIG. 2 (Example V6). The stress (MPa) is measured depending on the strain [%] according to tensile test ISO 527-2:2012 at 50 mm/min, as of 2019. The different temperatures are indicated in FIG. 1 and FIG. 2 with low temperatures above and high temperatures below.

[0183] FIG. 1 refers to composition C1 which has a theoretical thermoforming window of 210 to 220° C.

[0184] FIG. 2 refers to composition V6, which has a theoretical thermoforming window of from 120 to 220° C.

[0185] The following figures show the sliding curves for the other examples:

[0186] FIG. 4—Example V1

[0187] FIG. 5—Example V2

[0188] FIG. 6—Example V3

[0189] FIG. 7—Example C2

[0190] FIG. 8—Example C3

[0191] FIG. 9—Example V4

[0192] FIG. 10—Example V5