CN113831715A

CN113831715A - Polycarbonate composite material and preparation method and application thereof

Info

Publication number: CN113831715A
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: 2021-12-24
Anticipated expiration: 2041-09-28
Also published as: CN113831715B

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 invention improves the fluidity and the thermal oxygen aging resistance by adding a certain amount of PBAT in a PC/EVA system; on the other hand, EVA also improves the 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, polycarbonate PC products have the characteristics of good transparency, high impact resistance, high heat resistance, good dimensional stability, good flame retardant property and the like, and are widely applied to the fields of automobiles, IT, electronic appliances, household appliances and the like; has the defects of high melt viscosity, large residual internal stress, easy crack sensitivity of a notch and the like. The poly (terephthalic acid) -succinic 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 macromolecules have soft aliphatic chains and rigid aromatic groups; in addition, the biodegradable plastic has excellent biodegradability, and is one of the best degradable materials which are very active in the research of the current biodegradable plastics and are applied to the market.

Since polycarbonate has excellent transparency and high toughness, but is susceptible to stress cracking, it is required to modify it to improve stress cracking resistance. First, the prior art modifies by adding PBAT, but on the one hand, the transesterification reaction between PC and PBAT is easily carried out during melt blending, thereby degrading the performance in all aspects, and therefore, a sufficient amount of transesterification inhibitor needs to be added. On the other hand, the compatibility between two resins, PC and PBAT, is not so satisfactory, bringing difficulty to practical application thereof. Secondly, toughening modification of polycarbonate with EVA has also been reported, but the addition of EVA tends to result in poor thermal oxygen 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 effect and the like.

Another object of the present invention is to provide a method for preparing 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 segment repeating unit, the weight content of the butylene terephthalate unit is 40 to 60wt%, and the weight content of the butylene adipate unit is 40 to 60 wt%.

The polycarbonate resin of the present invention may be obtained by reacting a dihydroxy compound or a dihydroxy compound with a small amount of a polyhydroxy compound and phosgene or a carbonic acid diester. The present invention is not particularly limited to the production method of the polycarbonate resin, and polycarbonate resins produced by a phosgene method (interfacial polymerization method) or a melting method (transesterification method) known so far may be used. The dihydroxy compound may be exemplified by 2, 2-bis (4-hydroxyphenyl) propane (i.e., bisphenol a), tetramethylbisphenol a, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4-dihydroxydiphenyl, etc., of which bisphenol a is preferred. It is also possible to use compounds in which at least one tetraalkyl phosphine sulfonate is bound to the aforementioned dihydroxy compounds. The polycarbonate resin may also be a copolymer in which the main component of the segment 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 polycarbonate has an average molecular weight of 17000-20000.

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

Preferably, the weight content of butylene terephthalate units and butylene adipate units in the repeating units of the PBAT segment is 45 to 55wt% and 45 to 55 wt%.

The intrinsic viscosity of PBAT is not limited in the invention, and the test shows that the object of the invention can be realized when the intrinsic viscosity of PBAT is 1-3.5dL/g (test condition 25 ℃).

The source of PBAT may be home-made or commercially available. The preparation of PBAT in the examples is provided below: firstly, 1, 4-butanediol, adipic acid, terephthalic acid and tetrabutyl titanate serving as a catalyst are added into a reaction container according to the measurement, the temperature is raised to 160-180 ℃, the reaction is continued for 4 to 5 hours, and nitrogen is introduced in the process until no water is distilled out. In the second step, the temperature is raised to 240 ℃ and the vacuum degree is maintained at 20-30 Pa. When the viscosity reaches the set value, the reaction is stopped to obtain the designed PBAT.

Intrinsic viscosity test: mixing phenol-tetrachloroethane 1:1 as solvent, preparing PBAT or PBSA solution with mass concentration of 2.5g/L, standing for 24h, and measuring at 25 deg.C with Ubbelohde viscometer.

Whether one or more of a transesterification inhibitor, a hydrolysis resistance agent, an antioxidant and a lubricant are added can be selected according to actual needs.

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

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

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 has little influence on the flowability of polycarbonate due to its characteristics, resulting in a defect of uneven blending upon melt extrusion easily occurring. The melt flow stability of the composite material is improved by adding PBAT; the existence of EVA improves the compatibility between polycarbonate and PBAT and improves the thermal oxygen aging resistance; meanwhile, the polycarbonate composite material has the advantage of low addition amount (0-0.1 part) of the ester exchange inhibitor, and even can be not added.

2. In the technical scheme of the invention, the addition of the hydrolysis resistant agent can further improve the thermal oxygen 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 invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

The examples of the invention and the comparative examples used the following raw materials:

polycarbonate A: the average molecular weight is 1.5 ten thousand, and the light emission is FN 1500;

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

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

polycarbonate D: average molecular weight 3.5 ten thousand, Mitsubishi E-1000F.

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

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

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

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

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

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

PBAT-A: 45wt% of butylene terephthalate units, 55wt% of butylene adipate units, an intrinsic viscosity of 1.8dL/g, 25 ℃, available from KMI under the designation KM 801T;

PBAT-B: 55wt% of butylene terephthalate units, 45wt% of butylene adipate units, an intrinsic viscosity of 2.0dL/g, 25 ℃, available from AFC Ecoplatics under the trademark ANBIO BG 1000;

PBAT-C: the weight content of a butanediol terephthalate unit is 40wt%, the weight content of a butanediol adipate unit is 60wt%, the intrinsic viscosity is 1.9dL/g, and the self-made is carried out at 25 ℃;

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

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

PBAT-F: 65wt% of butylene terephthalate unit, 35wt% of butylene adipate unit, 1.85dL/g of intrinsic viscosity and 25 ℃, and is prepared by a user;

octadecyl phosphate ester: C18P, arsius, transesterification inhibitor.

Bisphenol a bisglycidyl ether: kaiser, Haiyuan, hydrolysis resistant agent.

Examples and comparative polycarbonate composites preparation methods: the polycarbonate, the ethylene-vinyl acetate copolymer, the PBAT, the ester exchange inhibitor and the hydrolysis resistant agent are uniformly mixed according to the proportion, and are extruded and granulated by a double-screw extruder, wherein the temperature range of the screw is 140 ℃ in a first region of 120-.

The test methods are as follows:

(1) thermal oxygen aging resistance: the baked specimens were tested for retention of properties of impact strength at 70 ℃ for 300 hours according to ISO-179-1-2010 standard.

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

In the following examples and comparative examples, heat aging resistance was the main property to be investigated.

Table 1: EXAMPLES 1-6 polycarbonate composites content of Components (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
							Ester interchange inhibitor	0.03	0.03	0.03	0.03	0.03	0.03
Thermal oxygen aging resistance (retention of impact strength%)	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

From examples 1 to 4, it is understood that the thermal oxygen aging resistance is increased when the average molecular weight of PC is increased, but the thermal oxygen aging resistance is gradually increased when the average molecular weight reaches 2 ten thousand, but the melt flow index is excessively decreased, so that the average molecular weight is preferably from 1.7 ten thousand to 2 ten thousand.

Table 2: EXAMPLES 7-11 polycarbonate composites content of Components (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
Ester interchange inhibitor	0.03	0.03	0.03	0.03	0.03
						Thermal oxygen aging resistance (retention of impact Strength)	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 can be seen from a comparison of examples 3/7-11, the preferred ethylene content of EVA gives the best resistance to thermal oxidation.

Table 3: examples 12-15 polycarbonate composites content of Components (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
Ester interchange inhibitor	0.03	0.03	0.03	0.01
					Hydrolysis resistant agent	0.1	0.1	0.1
Thermal oxygen aging resistance (retention of impact Strength)	87.2	66.4	69.6	87.0
					Melt flow index, g/10min	10.9	13.6	9.8	11.3

It is clear from the comparison of example 3/12/13/14 that the PBAT segment repeat units significantly affect the thermal oxygen aging resistance and melt flow properties of the polycarbonate composite, with the preferred PBAT having better thermal aging resistance.

Table 4: comparative example polycarbonate composite Material content of each component (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
Ester interchange inhibitor	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 oxygen aging resistance (retention of impact Strength)	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

From comparative example 1/2, it can be seen that PBAT resins outside the scope of the invention do not have sufficient build-up for polycarbonate/EVA compatibility.

From comparative example 3/4, too low a PBAT content is also insufficient for improving the polycarbonate/EVA compatibility; an excessively high PBAT content would rather reduce the resistance to thermal oxygen ageing, and in practice the melt would easily delaminate despite a high melt flow index value.

It is understood from comparative example 5/6 that it is difficult to improve the thermal oxygen aging resistance even if the contents of the transesterification inhibitor and the hydrolysis resistance agent are increased when EVA is not added.

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;

2. The polycarbonate composite of claim 1, wherein the polycarbonate has an average molecular weight of 15000-40000; preferably, the polycarbonate has an average molecular weight of 17000-20000.

3. The polycarbonate composite material according to claim 1, wherein the ethylene-vinyl acetate copolymer has a vinyl acetate content of 12 to 25wt% and a melt index of 8 to 20 g/10min (190 ℃, 2.16 kg); preferably, the content of the vinyl acetate in the ethylene-vinyl acetate copolymer is 16-20 wt%.

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

5. The polycarbonate composite of claim 1, wherein the PBAT has an intrinsic viscosity of 1 to 3.5dL/g, at 25 ℃ test condition.

6. The polycarbonate composite of claim 1, further comprising 0-5 parts by weight of one or more of a transesterification inhibitor, a hydrolysis resistance agent, an antioxidant, and a lubricant.

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

8. The polycarbonate composite of claim 6, wherein the hydrolysis resistance agent is selected from at least one of phenyl glycidyl ether, bisphenol A diglycidyl ether, carbodiimide, or 2-oxazoline.

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

10. Use of the polycarbonate composite material according to any one of claims 1 to 8, in films for electronic and electrical applications.