CN113831715B

CN113831715B - Polycarbonate composite material and preparation method and application thereof

Info

Publication number: CN113831715B
Application number: CN202111145621.5A
Authority: CN
Inventors: 田征宇; 王玉康; 刘志雄; 刘贤文; 董相茂
Original assignee: Shanghai Kingfa Science and Technology Co Ltd; Jiangsu Kingfa New Material Co Ltd
Current assignee: Shanghai Kingfa Science and Technology Co Ltd; Jiangsu Kingfa New Material Co Ltd
Priority date: 2021-09-28
Filing date: 2021-09-28
Publication date: 2023-07-25
Anticipated expiration: 2041-09-28
Also published as: CN113831715A

Abstract

The invention provides a polycarbonate composite material, which comprises the following components in parts by weight: 80 parts of polycarbonate; 5-10 parts of ethylene-vinyl acetate copolymer; 10-20 parts of PBAT. On one hand, the flowability and the thermo-oxidative aging resistance are improved by adding a certain amount of PBAT into a PC/EVA system; on the other hand, EVA also improves compatibility between PC/PBAT.

Description

Polycarbonate composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a polycarbonate composite material and a preparation method and application thereof.

Background

As known in the technical field, the polycarbonate PC product has the characteristics of good transparency, high impact resistance, high heat resistance, good dimensional stability, good flame retardant property and the like, and is widely applied to the fields of automobiles, IT, electronic appliances, household appliances and the like; the defects are that the melt viscosity is high, the residual internal stress is high, the notch sensitivity is easy to crack, and the like. The poly (terephthalic acid) -butanedioic acid-1, 4 butanediol copolyester (PBAT) belongs to thermoplastic biodegradable plastics, has the characteristics of PBA and PBT, and has better ductility and elongation at break because the macromolecule has soft aliphatic chains and rigid aromatic groups; in addition, the material also has excellent biodegradability, and is one of the best degradable materials which are very active in the research of biodegradable plastics and are applied to the market at present.

Since polycarbonate has excellent transparency and high toughness, but it is prone to stress cracking, modification is required to improve stress cracking resistance. First, the modification is carried out by adding PBAT in the prior art, but on the one hand, transesterification reaction between PC and PBAT is easily carried out during melt blending to lower the performance in all aspects, so that a sufficient amount of transesterification inhibitor needs to be added. On the other hand, the compatibility between the two resins of PC and PBAT is not satisfactory, which makes practical use difficult. Second, there are reports of toughening modification of polycarbonate with EVA, but addition of EVA tends to cause poor thermo-oxidative aging resistance, and insufficient melt flow stability.

Disclosure of Invention

The invention aims to provide a polycarbonate composite material which has the advantages of good fluidity, good compatibility, good thermo-oxidative aging resistance and the like.

Another object of the present invention is to provide a method for producing the polycarbonate composite material.

The invention is realized by the following technical scheme:

the polycarbonate composite material comprises the following components in parts by weight:

80 parts of polycarbonate;

5-10 parts of ethylene-vinyl acetate copolymer;

10-20 parts of PBAT;

in the PBAT chain segment repeating unit, the weight content of the butylene terephthalate unit is 40-60wt%, and the weight content of the butylene adipate unit is 40-60wt%.

The polycarbonate resin of the present invention may be obtained by reacting a dihydroxy compound or its and a small amount of a polyhydroxy compound with phosgene or a carbonic diester. The present invention is not particularly limited to a production method of the polycarbonate resin, and a polycarbonate resin produced by a heretofore known phosgene method (interfacial polymerization method) or a melt method (transesterification method) may be used. The dihydroxy compound may be exemplified by 2, 2-bis (4-hydroxyphenyl) propane (i.e., bisphenol A), tetramethyl bisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4-dihydroxydiphenyl, etc., with bisphenol A being preferred. Compounds in which at least one tetraalkyl phosphine sulfonate is bound to the aforementioned dihydroxy compound may also be used. The polycarbonate resin may also be a copolymer of a segment whose main composition is an aromatic monomer, for example, a copolymer with a polymer or oligomer containing a siloxane structure.

The average molecular weight of the polycarbonate is 15000-40000; preferably, the average molecular weight of the polycarbonate is 17000-20000.

Preferably, in the ethylene-vinyl acetate copolymer, the vinyl acetate content is 12-25wt%, and the melt index is 8-20 g/10min (190 ℃,2.16 kg); more preferably, the ethylene-vinyl acetate copolymer has a vinyl acetate content of 16 to 20wt%.

Preferably, the weight content of the polybutylene terephthalate unit in the PBAT chain segment repeating unit is 45-55wt%, and the weight content of the polybutylene adipate unit is 45-55wt%.

The intrinsic viscosity of PBAT is not limited in the present invention, and it has been found through experiments that the object of the present invention can be achieved when the intrinsic viscosity of PBAT is 1-3.5dL/g (test condition 25 ℃).

The source of PBAT may be homemade or commercially available. The preparation method of PBAT in the examples is provided below: firstly, 1, 4-butanediol, adipic acid, terephthalic acid and tetrabutyl titanate serving as a catalyst are firstly added into a reaction container according to the metering, the temperature is raised to 160-180 ℃ for 4-5 hours, and nitrogen is introduced in the process until no water is distilled out. And step two, raising the temperature to 220-240 ℃ and maintaining the vacuum degree to 20-30Pa. Stopping the reaction when the viscosity reaches the set value to obtain the designed PBAT.

Intrinsic viscosity test: mixing phenol and tetrachloroethane with a ratio of 1:1 as a solvent, preparing a PBAT or PBSA solution with a mass concentration of 2.5g/L, standing for 24 hours, and measuring at 25 ℃ by using a Ubbelohde viscometer.

Whether one or more of a transesterification inhibitor, a hydrolysis inhibitor, an antioxidant and a lubricant are added or not can be selected according to actual needs.

The amount of the transesterification inhibitor added is generally in the range of 0 to 0.1 part, and the transesterification inhibitor is at least one selected from sodium dihydrogen phosphate, octadecyl phosphate and triphenyl phosphate. The addition amount of the hydrolysis-resistant agent can be added according to actual needs, the addition amount ranges from 0 part to 3 parts, and the hydrolysis-resistant agent is at least one selected from phenyl glycidyl ether, bisphenol A diglycidyl ether, carbodiimide and 2-oxazoline.

The preparation method of the polycarbonate composite material comprises the following steps: the components are uniformly mixed according to the proportion, extruded and granulated by a double-screw extruder, the temperature range of the screw is 220-260 ℃, and the rotating speed range is 300-600rpm, so as to obtain the polycarbonate composite material.

The polycarbonate composite material is applied to electronic and electric appliance films.

The invention has the following beneficial effects:

1. EVA has a lower melt viscosity relative to polycarbonate, but because of its characteristics, it has little effect on the flowability of polycarbonate, resulting in the disadvantage that blending unevenness at the time of melt extrusion is liable to occur. By adding PBAT, the melt flow stability of the composite material is improved; the EVA improves the compatibility between the polycarbonate and the PBAT, and improves the thermo-oxidative aging resistance; meanwhile, the polycarbonate composite material has the advantage of low addition amount (0-0.1 part) of the transesterification inhibitor, and even can be added without adding the transesterification inhibitor.

2. In the technical scheme of the invention, the addition of the hydrolysis resistance agent can further improve the thermo-oxidative aging resistance.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.

The raw materials used in the examples and comparative examples of the present invention are as follows:

polycarbonate a: average molecular weight 1.5 ten thousand, light-emitting FN1500;

polycarbonate B: the average molecular weight is 1.7 ten thousand, mitsubishi H-3000F;

polycarbonate C: the average molecular weight is 2 ten thousand, mitsubishi H-2000F;

polycarbonate D: the average molecular weight is 3.5 ten thousand, mitsubishi E-1000F.

EVA-A: ethylene content of 12.5wt% and melt index of 10.5g/10min (190 ℃,2.16 kg);

EVA-B: ethylene content of 24wt% and melt index of 17 g/10min (190 ℃,2.16 kg);

EVA-C: ethylene content of 16wt% and melt index of 12 g/10min (190 ℃,2.16 kg);

EVA-D: ethylene content of 20wt% and melt index of 9.8 g/10min (190 ℃,2.16 kg);

EVA-E: ethylene content of 10wt% and melt index of 14 g/10min (190 ℃,2.16 kg);

EVA-F: ethylene content of 30wt% and melt index of 11g/10min (190 ℃,2.16, kg);

PBAT-a: the weight content of the butylene terephthalate unit is 45wt%, the weight content of the butylene adipate unit is 55wt%, the intrinsic viscosity is 1.8dL/g, the temperature is 25 ℃, and the butylene terephthalate unit is purchased from KMI with the brand KM801T;

PBAT-B: the weight content of the butylene terephthalate unit is 55wt%, the weight content of the butylene adipate unit is 45wt%, the intrinsic viscosity is 2.0dL/g, and the butylene adipate unit is available from AFC ecosystems under the brand name ANBIO BG1000;

PBAT-C: the weight content of the butylene terephthalate unit is 40 percent, the weight content of the butylene adipate unit is 60 percent, the intrinsic viscosity is 1.9dL/g, and the self-made product is prepared at 25 ℃;

PBAT-D: the weight content of the butylene terephthalate unit is 60wt%, the weight content of the butylene adipate unit is 40wt%, the intrinsic viscosity is 2.1dL/g, and the self-made product is at 25 ℃;

PBAT-E: the weight content of the butylene terephthalate unit is 35wt%, the weight content of the butylene adipate unit is 65wt%, the intrinsic viscosity is 2.0dL/g, and the butylene adipate unit is self-made at 25 ℃;

PBAT-F: the weight content of the butylene terephthalate unit is 65wt%, the weight content of the butylene adipate unit is 35wt%, the intrinsic viscosity is 1.85dL/g, and the butylene adipate unit is self-made at 25 ℃;

octadecyl phosphate: C18P, alcissi, transesterification inhibitors.

Bisphenol a diglycidyl ether: kesai, maritime, hydrolysis inhibitor.

Examples and comparative examples polycarbonate composite preparation method: uniformly mixing polycarbonate, ethylene-vinyl acetate copolymer, PBAT, ester interchange inhibitor and hydrolysis inhibitor according to the proportion, extruding and granulating by a double-screw extruder, wherein the temperature range of a screw is 120-140 ℃ in a first region, 160-180 ℃ in a second region, 220-240 ℃ in a third region, 240-260 ℃ in a fourth region, 240-260 ℃ in a fifth region, 4, 220-240 ℃ in a sixth region, 220-240 ℃ in a seventh region, 220-240 ℃ in an eighth region, 200-220 ℃ in a ninth region, 240-260 ℃ in a tenth region and the rotating speed range of 350rpm, and obtaining the polycarbonate composite material.

The testing method comprises the following steps:

(1) Thermal oxidative aging resistance: the retention of impact strength of the unbaked and baked bars was measured according to ISO-179-1-2010 standard after baking at 70℃for 300 hours.

(2) Melt flow: according to the melt index of the test material under the conditions of 260 ℃ and 2.16kg according to ISO 1133-1-2011, the melt index is a key index for measuring the flowability of the material.

In the following examples and comparative examples, the heat aging resistance was mainly examined.

Table 1: examples 1-6 polycarbonate composite materials component contents (parts by weight) and test results

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							Polycarbonate A	80
Polycarbonate B		80
							Polycarbonate C			80		80	80
Polycarbonate D				80
							EVA-A	5	5	5	5	10	8
PBAT-A	10	10	10	10	20	15
							Transesterification inhibitors	0.03	0.03	0.03	0.03	0.03	0.03
Thermal oxidative aging resistance (impact Strength retention%)	55.7	75.7	81.5	82.1	84.9	89.1
							Melt flow index, g/10min	32.7	26.1	12.1	4.5	17.7	14.2

As is clear from examples 1 to 4, when the average molecular weight of PC increases, the thermal oxidative aging resistance increases, but after the average molecular weight reaches 2 ten thousand, the thermal oxidative aging resistance increases smoothly, but the melt flow index decreases too much, so that the average molecular weight is preferably 1.7 ten thousand to 2 ten thousand.

Table 2: examples 7-11 polycarbonate composite materials component contents (parts by weight) and test results

	Example 7	Example 8	Example 9	Example 10	Example 11
						Polycarbonate C	80	80	80	80	80
EVA-B	5
						EVA-C		5
EVA-D			5
						EVA-E				5
EVA-F					5
						PBAT-A	10	10	10	10	10
Transesterification inhibitors	0.03	0.03	0.03	0.03	0.03
						Thermal oxidative aging resistance (impact strength retention)	83.7	87.7	89.5	72.1	75.1
Melt flow index, g/10min	14.7	10.2	11.9	10.1	16.6

As is evident from the comparison of examples 3/7-11, EVA has the best resistance to thermo-oxidation at the preferred ethylene content.

Table 3: examples 12-15 polycarbonate composite materials component contents (parts by weight) and test results

	Example 12	Example 13	Example 14	Example 15
					Polycarbonate C	80	80	80	80
EVA-A	5	5	5	5
					PBAT-B	10			10
PBAT-C		10
					PBAT-D			10
Transesterification inhibitors	0.03	0.03	0.03	0.01
					Hydrolysis-resistant agent	0.1	0.1	0.1
Thermal oxidative aging resistance (impact strength retention)	87.2	66.4	69.6	87.0
					Melt flow index, g/10min	10.9	13.6	9.8	11.3

As can be seen from the comparison of examples 3/12/13/14, the PBAT segment repeat units significantly affect the thermal oxidative aging resistance, melt flow properties of the polycarbonate composite, with preferred PBAT thermal aging resistance being better.

Table 4: comparative example polycarbonate composite Material component content (parts by weight) and test results

	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6
							Polycarbonate C	80	80	80	80	80	80
EVA-A	5	5	10	5
							PBAT-A			5	25	10	10
PBAT-E	10
							PBAT-F		10
Transesterification inhibitors	0.03	0.03	0.03	0.03	0.03	0.08
							Hydrolysis-resistant agent	0.1	0.1	0.1	0.1	0.1	0.2
Thermal oxidative aging resistance (impact strength retention)	47.3	48.3	51.5	39.1	31.9	32.7
							Melt flow index, g/10min	13.3	8.2	28.1 but unstable	38.2 but unstable	18.4 but unstable	16.2 but unstable

As is clear from comparative example 1/2, PBAT resins not falling within the scope of the present invention are insufficient in improvement of polycarbonate/EVA compatibility.

As is clear from comparative examples 3/4, too low a PBAT content is insufficient in improving the compatibility of polycarbonate/EVA; too high a PBAT content would instead reduce the resistance to thermo-oxidative aging, and in practice the melt is prone to delamination despite the high melt flow index value.

As is clear from comparative example 5/6, if EVA is not added, it is difficult to improve the thermo-oxidative aging resistance even if the contents of the transesterification inhibitor and the hydrolysis inhibitor are increased.

Claims

1. The polycarbonate composite material is characterized by comprising the following components in parts by weight:

80 parts of polycarbonate;

5-10 parts of ethylene-vinyl acetate copolymer;

10-20 parts of PBAT;

in the PBAT chain segment repeating unit, the weight content of the butylene terephthalate unit is 40-60wt%, and the weight content of the butylene adipate unit is 40-60wt%;

the average molecular weight of the polycarbonate is 15000-40000;

in the ethylene-vinyl acetate copolymer, the vinyl acetate content is 12-25wt%.

2. The polycarbonate composite material according to claim 1, wherein the average molecular weight of the polycarbonate is 17000 to 20000.

3. The polycarbonate composite of claim 1, wherein the ethylene-vinyl acetate copolymer has a melt index of 8 to 20 g/10min at 190 ℃ and a vinyl acetate content of 16 to 20 wt.% at 2.16 kg.

4. The polycarbonate composite material of claim 1, wherein the weight content of butylene terephthalate units and the weight content of butylene adipate units in the PBAT segment repeat units are 45-55wt%.

5. The polycarbonate composite material of claim 1, wherein the intrinsic viscosity of the PBAT is 1-3.5dL/g, under test conditions of 25 ℃.

6. The polycarbonate composite material according to claim 1, further comprising one or more of a transesterification inhibitor, a hydrolysis inhibitor, an antioxidant, and a lubricant in an amount of 0 to 5 parts by weight.

7. The polycarbonate composite material according to claim 6, wherein the transesterification inhibitor is at least one selected from the group consisting of sodium dihydrogen phosphate, octadecyl phosphate and triphenyl phosphate.

8. The polycarbonate composite material according to claim 6, wherein the hydrolysis inhibitor is at least one selected from the group consisting of phenyl glycidyl ether, bisphenol a diglycidyl ether, carbodiimide and 2-oxazoline.

9. The method for preparing a polycarbonate composite material according to any one of claims 1 to 8, comprising the steps of: the components are uniformly mixed according to the proportion, extruded and granulated by a double-screw extruder, the temperature range of the screw is 220-260 ℃, and the rotating speed range is 300-600rpm, so as to obtain the polycarbonate composite material.

10. Use of a polycarbonate composite material according to any of claims 1-8, for an electronic and electrical film.