Composition of PBAT resin

Abstract

The present invention discloses a PBAT resin composition comprising: (a) Poly (butyleneadipate-co-terephthalate); (b) a cyclic esterified product having a structure represented by the formula (I) ##STR00001## Wherein the content by weight of the cyclic esterified product is from 10 ppm to 2000 ppm, based on the total weight of the PBAT resin composition. In the present invention, the service life of the PBAT resin composition can be greatly extended by adding cyclic esterified product in the PBAT resin composition and controlling the content of the cyclic esterified product in the composition in the range of 10 ppm to 2000 ppm. And after boiled for 240 hours in 95% ethanol at 40 C., the film produced from blowing or the articles produced from injection have less surface precipitates, with excellent surface appearance properties.

Claims

1. A PBAT resin composition comprising the following components: (a) poly (butyleneadipate-co-terephthalate); (b) a cyclic esterified product having a structure represented by the formula (I) ##STR00003## wherein a content by weight of the cyclic esterified product is from 10 ppm to 2000 ppm, based on a total weight of the PBAT resin composition.

2. A PBAT resin composition according to claim 1, wherein the content by weight of the cyclic esterified product is measured by the following method: weigh accurately 1.2000 g of the PBAT resin composition, put it into a 25 ml volumetric flask, dissolve it by chloroform, dilute it to 25 ml after the PBAT resin composition is completely dissolved, measure the peak area of the cyclic esterified product in the above solution by GC-MS, calculate the content of the cyclic esterified product of the PBAT resin composition according to the peak area of the cyclic esterified product and the cyclic esterification standard curve, which may be calibrated by the cyclic esterified product/chloroform solution.

3. A PBAT resin composition according to claim 1, wherein the content by weight of the cyclic esterified product is from 80 ppm to 1250 ppm, or from 180 ppm to 850 ppm, based on the total weight of the PBAT resin composition.

4. A PBAT resin composition according to claim 1, wherein a content by weight T % of the butylene terephthalate unit in the poly (butyleneadipate-co-terephthalate) is 35 wt % to 65 wt %.

5. A PBAT resin composition according to claim 1, wherein a melt index of the poly (butyleneadipate-co-terephthalate) resin is in a range of 8 g/10 min to 25 g/10 min at a temperature of 190 C. and a load of 5 kg in accordance with GB/T 3682-2000 standard.

6. A PBAT resin composition according to claim 1, wherein the PBAT resin composition further comprises other adjuvants which are one or more of antioxidants, light stabilizers, impact modifiers, flame retardant, fluorescent whitening agent, lubricant, plasticizer, antistatic agent, mold release agent, or pigment.

7. A PBAT resin composition according to claim 1, wherein the PBAT resin has a half-life of more than 50 days after hot and humid aging at a temperature of 60 C. and humidity of 60% in a box with a constant temperature and a constant humidity.

8. A PBAT resin composition according to claim 1, wherein the PBAT resin composition has a L value0.60 after boiled for 240 hours in 95% ethanol at 40 C.

Description

EMBODIMENTS

(1) The present invention is further illustrated by the following specific examples. The following examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples.

(2) The cyclic esterified products, antioxidants 1010 and erucamide used in the present invention are all commercially available.

(3) Synthesis Method of PBAT Resin:

(4) The measured terephthalic acid and 1,4-butanediol are put into a reaction kettle, and the temperature is raised to 240 C.-260 C. with prior replacement by nitrogen. After reaction for 2-4 hours, adipic acid is added and the temperature is raised to 240 C.-260 C. The reaction is continued for 2-4 hours, appropriate amount of catalyst and stabilizer are added to it to reduce the pressure in the reactor to below 50 Pa within 30 min, the reaction is continued for 2-5 hours at 240 C.-260 C., stirring is stopped and the reactor is filled with high purity nitrogen, the resin is driven out from the reactor, granulated into PBAT resin. PBAT resin with different content of butylene terephthalate unit can be obtained depending on the charge amount of terephthalic acid and adipic acid.

(5) Wherein the content of the butylene terephthalate unit is determined by .sup.1H NMR test, using deuterated chloroform as the solvent, and TMS as the internal standard, and the results are calculated according to the following formula:

(6) $T\%=\frac{220*S_{8.1}}{220*S_{8.1}+200*S_{2.3}}*100\%$
Wherein: T % is the content of the butylene terephthalate unit;
S.sub.8 is the absorption peak area at 8.1 ppm in .sup.1H NMR spectrum;
S.sub.2.3 is the absorption peak area at 2.3 ppm in the .sup.1H NMR spectrum;

Examples 1-15 and Comparative Examples 1-3

(7) According to the formulation shown in Table 1, PBAT resin, cyclic esterified product, antioxidant 1010, erucic acid amide and other auxiliaries are mixed and put into a single-screw extruder, extruded at 140-240 C., granulated to give the composition. For the performance test data, see Table 1.

(8) Performance Evaluation Method:

(9) (1) Evaluation Method of Service Life of Molded Article:

(10) The molded articles obtained from the PBAT composition are put into a thermo-hygrostat at 60 C. and 60% relative humidity for wet heat aging test, and sampled every other 3 days to test the longitudinal and transverse tear properties of the molded product. When Longitudinal and transverse tear properties are decayed to about 50%, it will reach the half-life of the sample. The shorter half-life, the shorter the service life of the PBAT molded products.
(2) Evaluation Method of Surface Appearance Property of Molded Article:
Place the 2 mm injection color plate in 95% ethanol solution at 95 C., boiled for 240 h, then place it in a standard laboratory with ambient temperature of (232) C. and relative humidity of 45%-55%, adjust it for 48 h, then measure the L value difference L before and after the treatment of the palette with a colorimeter. The larger the L, the more the surface precipitates and the worse the surface appearance.
(3) Determination Method of Cyclic Esterified Product:
Accurately weigh 1.2000 g PBAT resin composition, put it into a 25 ml volumetric flask and dissolve it with chloroform until the PBAT resin composition is completely dissolved, dilute it to 25 ml. Measure the peak area of the cyclic esterified product in the above solution by GC-MS, calculate the content of the cyclic esterified product of the PBAT resin composition according to the peak area of the cyclic esterified product and the cyclic esterification standard Curve, which may be calibrated by the cyclic esterified product/chloroform solution.

(11) TABLE-US-00001 TABLE 1 Test data (by weight) of Comparative Examples (CE)1 to 3 and Embodiment examples 1-15 CE 1 CE 2 CE3 Emb 1 Emb 2 Emb 3 Emb 4 Emb 5 Emb 6 Emb 7 PBAT Amount added 100 100 100 100 100 100 100 100 100 100 Melt Index 15 15 15 15 10 8 13 16 18 25 (g/10 min) T % 50 50 50 50 65 35 40 51 54 55 Cyclic Ester Content (based on 0 5 2320 180 204 320 418 569 740 850 total composition)/ppm Antioxidant 1010 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Erucic amide 1 1 1 1 1 1 1 1 1 1 Half-life/day 16 20 32 70 75 80 86 98 101 110 L 0.03 0.08 1.12 0.20 0.24 0.28 0.30 0.37 0.38 0.40 Emb8 Emb9 Emb10 Emb11 Emb12 Emb13 Emb14 Emb15 PBAT Amount added 100 100 100 100 100 100 100 100 Melt Index 23 17 14 21 16 12 9 19 (g/10 min) T % 51 52 53 49 48 59 56 45 Cyclic Ester Content (based on 80 95 1062 1250 10 20 1781 2000 total composition)/ppm Antioxidant 1010 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Erucic amide 1 1 1 1 1 1 1 1 Half-life/day 60 62 63 68 52 55 57 58 L 0.45 0.42 0.47 0.50 0.52 0.55 0.56 0.60
As can be seen in Table 1, PBAT composition with a cyclic esterified product content of 10 to 2000 ppm will have a longer service life, and L0.60 after boiled in 95% ethanol at 40 C. for 240 hours, indicating that the composition has excellent surface appearance performance. Whereas comparative example 1 does not contain any cyclic esterified product and the cyclic esterified product content of comparative example 2 is less than 10 ppm, so the composition has a shorter service life, although the L value of the composition is small. In comparative example 3, the content of the cyclic esterified product exceeds 2000 ppm, the L is 1.0 or larger, indicating that the surface appearance of the composition is inferior for more surface precipitates.