PET cold-resistant toughening agent, preparation method and application of PET cold-resistant toughening agent in PET

Abstract

The invention relates to a PET (Polyethylene Terephthalate) cold-resistant toughening agent, a preparation method and application thereof in PET, triglycidyl isocyanurate, fatty diacid and a liquid catalyst are put in a pressure reaction kettle to react under the protection of nitrogen. Then adding aliphatic glycidyl ether epoxy resin and an ultra-solid acid catalyst, and reacting under the protection of nitrogen; and then adding fatty acid and an ultra-solid acid catalyst, continuously reacting under the protection of nitrogen, and cooling to obtain the PET cold-resistant toughening agent. The PET cold-resistant toughening agent is introduced into PET molecules in the processing process through special reactive groups, so that the molecular weight of the PET is improved, a long aliphatic chain can be introduced into the PET molecules, the flexibility of the PET molecules is improved, and the low-temperature toughness and the yield of the PET are improved. The auxiliary agent has good compatibility with the PET and does not migrate, so that the transparency of the PET is not influenced, and the application field of the PET is expanded.

Description

Technical Field

[0001] The invention relates to the field of auxiliary agent synthesis and new material application, and in particular to a PET cold-resistant toughening agent, a preparation method and application thereof in PET. Background Art

[0002] PET (polyethylene terephthalate) is a common engineering plastic with excellent comprehensive performance. It is in great demand in low-temperature refrigeration, food packaging, wine packaging, etc. With the expansion of PET production and application fields, the amount of recycled PET (RPET) has also gradually increased. Both new PET materials and RPET have the problems of high brittleness and low yield at low temperatures, which leads to the continuous increase in the cost of PET and the great restrictions on the occasions of use. According to the current market situation, it is urgent to develop an additive that can improve the low-temperature resistance of recycled PET to solve the technical problems of low-temperature brittleness and unsatisfactory stability in PET.

[0003] At present, there are several ways to improve the low temperature resistance of PET resin: First, add toughening agents to PET. For example, Tang Qiqi et al. (Research on the modification of PET by SEBS and toughening agents. Engineering Plastics Application. 2005, 33 (10: 12-15) used SEBS to toughen PET, patent number: CN 103275469 A invented a PET / TPR alloy strapping belt and its preparation method, patent number: CN 117903574 A invented a PET high-toughness cold-resistant agent and its preparation method, etc., using CPE, ACR, ABS, POE, SEBS, EPDM and other elastomers, which can improve the impact strength of plastics to a certain extent and improve the toughness of plastic sheets, but these elastomers are generally not compatible with PET, and need to be surface treated first, otherwise it is difficult to fully disperse in the PET system, and the improvement is not great. Moreover, due to the poor low temperature resistance of such elastomer toughening agents, they will lose toughness at low temperatures, and will cause the overall hardening and brittleness, so that the PET sheet cannot be kept in a low temperature environment. Maintain high impact strength. Second, introduce other resins into PET for modification to improve the cold resistance of PET. For example, patent number: CN103554849A discloses a cold-resistant and high-toughness PET / PC alloy material and its preparation method and application, using PC and terpolymer to improve the cold resistance of PET. The high amount of terpolymer added not only affects the cost of PET, but also affects the transparency of PET. Third, add additives such as nucleating agents, chain extenders, etc. to PET to improve the cold resistance of PET. For example, patent number CN115975356 B, discloses a cold-resistant PET material and its preparation method, using a nucleating agent to improve the cold resistance of PET. Wang Xiaoyan (Research on Engineering Toughening Modification of Polyester PET [D], 2010, Hubei University of Technology) uses chain extenders and the like to improve the toughness of PET. Although this method can improve the toughness of PET, it does not significantly improve the low-temperature brittleness of PET. Fourth, a special structure is used to improve the cold resistance of PET, such as patent number: CN 216183478 U, the utility model provides a cold-resistant PET sheet, including: a first base layer, a second base layer and an intermediate layer; the intermediate layer is arranged between the first base layer and the second base layer; the first base layer, the second base layer and the intermediate layer are all made of cold-resistant PET; the intermediate layer includes a plurality of mutually perpendicular horizontal strips and vertical strips; a plurality of the horizontal strips and a plurality of the vertical strips cross to form a plurality of cavities. The utility model has a stable structure with high strength, small change in low-temperature performance, softness, comfort and good elasticity, and wide application in thermal insulation. This method is only suitable for PET applications with special structures, and is difficult to adapt to PET applications such as injection molding and blister molding. Summary of the invention

[0004] In view of the above problems existing in the prior art, the purpose of the present invention is to provide an auxiliary agent that can improve the low temperature resistance of recycled PET, so as to solve the technical problems of low temperature brittleness and unsatisfactory stability existing in PET.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a PET cold-resistant toughening agent, whose structural formula is shown in molecular formula (1);

[0006]

[0007] R1 is:

[0008] R2 is:

[0009] A method for synthesizing a PET cold-resistant toughening agent comprises the following steps:

[0010] S1: 55-75 parts by weight of triglycidyl isocyanurate, 20-35 parts by weight of fatty diacid, and 3-5 parts by weight of liquid catalyst are placed in a pressure reactor, with a stirring speed of 500-1000 r / min, the system temperature is controlled at 150°C-170°C, the nitrogen flow rate is 120mL / min-150mL / min, and the reaction is carried out for 3h-6h.

[0011] S2: Then add 3-5 parts by weight of aliphatic glycidyl ether epoxy resin and 0.2-0.5 parts by weight of super solid acid catalyst, and continue the reaction for 2h-3h.

[0012] S3: Then add 10-20 parts by weight of fatty acid and 0.1-0.3 parts by weight of super solid acid catalyst, control the system temperature at 180°C-220°C, react for 3h-5h, and cool to obtain the auxiliary agent of the present invention.

[0013] Furthermore, the fatty diacid is shown in the molecular formula (2); preferably, dodecanedioic acid.

[0014]

[0015] Furthermore, the liquid catalyst is one or more of a single polyamine, a mixed polyamine or a modified polyamine.

[0016] Furthermore, the aliphatic glycidyl ether epoxy resin is one of 1,4-butanediol glycidyl ether and neopentyl glycol diglycidyl ether, or a mixture of the two, preferably 1,4-butanediol glycidyl ether.

[0017] Furthermore, the fatty acid is shown in the molecular formula (3); preferably octadecanoic acid (stearic acid).

[0018]

[0019] The invention discloses an application of a PET cold-resistant toughening agent in PET. The PET cold-resistant toughening agent is obtained by the above-mentioned preparation method, and the addition amount of the PET cold-resistant toughening agent is 5-10% of the mass of PET.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] The present invention synthesizes a type of PET cold-resistant toughening agent with a special structure through a simple and efficient chemical reaction. The PET cold-resistant toughening agent molecule contains a long fat chain and a special epoxy reaction group. The epoxy group reacts chemically with the active group on the PET molecule, such as -COOH. The cold-resistant toughening agent molecule is introduced into the PET molecule during the processing process, which not only improves the PET molecular weight, but also introduces the long fat chain into the PET molecule. The increase in molecular weight and the introduction of the long fat chain increase the flexibility of the PET molecule. The increase in the flexibility of the PET molecule increases the low-temperature toughness of the PET. At the same time, since the solubility parameters of the toughening agent and PET are similar, the two have good compatibility, and the toughening agent is very uniformly and stably dispersed in the PET, thereby improving the yield rate of PET products. Since the auxiliary agent has good compatibility with PET and will not migrate, it does not affect the transparency of PET, thereby expanding the application field of PET. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the infrared spectrum of the cold-resistant agent. The horizontal and vertical axes represent the wavelength and transmittance respectively. DETAILED DESCRIPTION

[0023] The present invention is specifically described below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art in this field can make some non-essential improvements and adjustments to the present invention based on the contents of the above invention.

[0024] Embodiment 1:

[0025] S1: 550 g of triglycidyl isocyanurate, 200 g of fatty diacid and 30 g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 3 hours.

[0026] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0027] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0028] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180℃-235℃ for granulation to obtain modified PET. The modified PET was vacuum dried at 120℃ for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240℃.

[0029] Embodiment 2:

[0030] S1: 750g of triglycidyl isocyanurate, 200g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0031] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0032] S3: Then add 10 g of stearic acid and 1 g of super solid acid catalyst, control the system temperature at 180° C., react for 3 h, and cool to obtain a PET cold-resistant toughening agent.

[0033] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0034] Embodiment 3:

[0035] S1: 600g of triglycidyl isocyanurate, 200g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0036] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0037] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0038] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0039] Embodiment 4:

[0040] S1: 600g of triglycidyl isocyanurate, 350g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0041] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0042] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0043] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0044] Embodiment 5:

[0045] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0046] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0047] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0048] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0049] Embodiment 6:

[0050] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0051] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0052] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0053] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0054] Embodiment 7:

[0055] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 1000r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0056] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0057] S3: Then add 10g of stearic acid and 1g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0058] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0059] Embodiment 8:

[0060] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 130ml / min, and the reaction was carried out for 3h.

[0061] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0062] S3: Then add 10 grams of stearic acid and 1 gram of super solid acid catalyst, control the system temperature at 180°C, react for 3 hours, and cool to obtain a PET cold-resistant toughening agent.

[0063] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0064] Embodiment 9:

[0065] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 150ml / min, and the reaction was carried out for 3h.

[0066] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0067] S3: Then add 20g of stearic acid and 2g of super solid acid catalyst, control the system temperature at 190°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0068] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0069] Embodiment 10:

[0070] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 140ml / min, and the reaction was carried out for 3h.

[0071] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0072] S3: Then add 15g of stearic acid and 3g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain the PET cold-resistant toughening agent after cooling.

[0073] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0074] Embodiment 11:

[0075] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 800r / min, the system temperature was controlled at 170°C, the nitrogen flow rate was 1450ml / min, and the reaction was carried out for 5h.

[0076] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 3 g of super solid acid catalyst HRD-02, and continue the reaction for 3 h.

[0077] S3: Then add 20g of stearic acid and 3g of super solid acid catalyst, control the system temperature at 180°C, react for 3h, and obtain PET cold-resistant toughening agent after cooling.

[0078] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0079] Embodiment 12:

[0080] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 150ml / min, and the reaction was carried out for 6h.

[0081] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 3.5 g of super solid acid catalyst HRD-02, and continue the reaction for 3 h.

[0082] S3: Then add 20g of stearic acid and 2.5g of super solid acid catalyst, control the system temperature at 175°C, react for 3h, and obtain PET cold-resistant toughening agent after cooling.

[0083] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0084] Embodiment 13:

[0085] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 150ml / min, and the reaction was carried out for 4h.

[0086] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 3 h.

[0087] S3: Then add 20g of stearic acid and 3g of super solid acid catalyst, control the system temperature at 220°C, react for 5h, and obtain the PET cold-resistant toughening agent after cooling.

[0088] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0089] Embodiment 14:

[0090] S1: 600g of triglycidyl isocyanurate, 300g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 700r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 150ml / min, and the reaction was carried out for 4h.

[0091] S2: Then add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 3 h.

[0092] S3: Then add 20g of stearic acid and 3g of super solid acid catalyst, control the system temperature at 200°C, react for 4h, and obtain PET cold-resistant toughening agent after cooling.

[0093] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0094] Embodiment 15:

[0095] S1: 500g of triglycidyl isocyanurate, 200g of fatty diacid and 30g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0096] S2: Add 30 g of 1,4-butanediol glycidyl ether and 2 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0097] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 180° C., the reaction time was 3 h, and the PET cold-resistant toughening agent was obtained after cooling.

[0098] 2000g of PET (or RPET) and 200g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4 hours and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0099] Embodiment 16:

[0100] S1: 500g of triglycidyl isocyanurate, 200g of fatty diacid and 50g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 5h.

[0101] S2: Add 30 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 3 h.

[0102] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 180° C., the reaction time was 3 h, and the PET cold-resistant toughening agent was obtained after cooling.

[0103] 2000g of PET (or RPET) and 200g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4 hours and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0104] Embodiment 17:

[0105] S1: 500g of triglycidyl isocyanurate, 200g of fatty diacid and 50g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120ml / min, and the reaction was carried out for 3h.

[0106] S2: Add 30 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0107] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 180° C., the reaction time was 3 hours, and the PET cold-resistant toughening agent was obtained after cooling.

[0108] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0109] Embodiment 18:

[0110] S1: 750 g of triglycidyl isocyanurate, 350 g of fatty diacid and 40 g of ethylenediamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 150°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 6 hours.

[0111] S2: Then add 50 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0112] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 180° C., the reaction time was 3 h, and the PET cold-resistant toughening agent was obtained after cooling.

[0113] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0114] Embodiment 19:

[0115] S1: 750 g of triglycidyl isocyanurate, 350 g of dodecanedioic acid and 40 g of ethylenetriamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 170°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 6 hours.

[0116] S2: Add 50 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0117] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 220° C., the reaction time was 3 h, and after cooling, a PET cold-resistant toughening agent was obtained.

[0118] 2000g of PET (or RPET) and 200g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4 hours and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0119] Embodiment 20:

[0120] S1: 750 g of triglycidyl isocyanurate, 350 g of dodecanedioic acid and 40 g of ethylenetriamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 4 hours.

[0121] S2: Add 50 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0122] S3: 10 g of oleic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 220° C., the reaction time was 3 h, and after cooling, a PET cold-resistant toughening agent was obtained.

[0123] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0124] Embodiment 21:

[0125] S1: 750 g of triglycidyl isocyanurate, 350 g of dodecanedioic acid and 40 g of ethylenetriamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 4 hours.

[0126] S2: Add 50 g of neopentyl glycol diglycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0127] S3: 10 g of oleic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 220° C., the reaction time was 3 h, and after cooling, a PET cold-resistant toughening agent was obtained.

[0128] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0129] Embodiment 22:

[0130] S1: 750 g of triglycidyl isocyanurate, 350 g of dodecanedioic acid and 40 g of ethylenetriamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 4 hours.

[0131] S2: Add 30 g of neopentyl glycol diglycidyl ether, 20 g of 1,4-butanediol glycidyl ether, and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0132] S3: 10 g of oleic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 220° C., the reaction time was 3 h, and after cooling, a PET cold-resistant toughening agent was obtained.

[0133] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0134] Embodiment 23:

[0135] S1: 750 g of triglycidyl isocyanurate, 350 g of sebacic acid and 40 g of ethylenetriamine were placed in a pressure reactor, the stirring speed was 500 r / min, the system temperature was controlled at 160°C, the nitrogen flow rate was 120 ml / min, and the reaction was carried out for 4 hours.

[0136] S2: Add 50 g of 1,4-butanediol glycidyl ether and 8 g of super solid acid catalyst HRD-02, and continue the reaction for 2 h.

[0137] S3: 10 g of stearic acid and 1 g of super solid acid catalyst were added, the system temperature was controlled at 220° C., the reaction time was 3 h, and after cooling, a PET cold-resistant toughening agent was obtained.

[0138] 2000g of PET (or RPET) and 100g of cold-resistant additive were added to a Φ35 twin-screw extruder (length-to-diameter ratio = 44:1) at 180-235°C for granulation to obtain modified PET. The modified PET was vacuum dried at 120°C for 4h and then injection molded into impact strips and fast food boxes with a wall thickness of 0.5mm. The maximum injection molding temperature was 240°C.

[0139] Test method description:

[0140] 1) Characterization of the external spectrum of the additive: Take the purified PET cold-resistant toughening agent, melt it and make it into a 1-2 mm thick sheet, and use Fourier infrared spectroscopy (using reflection method) to test its infrared spectrum, see Figure 1 .

[0141] 2) PET low temperature impact test: PET and RPET were injection molded into impact specimens and fast food boxes with a wall thickness of 0.5mm. After being placed in a refrigerator at -20℃ for 4 hours, the specimens were subjected to impact tests. The fast food boxes were placed 1m above the ground and freely fell onto the cement floor for a destruction test. The number of destroyed samples was counted. Five groups of each sample were tested and the average was taken.

[0142] Comparative Example 1:

[0143] After PET was vacuum dried at 120°C for 4 h, it was injection molded into impact specimens and fast food boxes with a wall thickness of 0.5 mm. The maximum injection molding temperature was 240°C.

[0144] Comparative Example 2:

[0145] The recycled RPET material from mineral water bottles was vacuum dried at 120°C for 4 hours and then injection molded into impact specimens and fast food boxes with a wall thickness of 0.5 mm. The maximum injection molding temperature was 240°C.

[0146] The low temperature impact properties of the materials prepared in Comparative Examples 1-2 and Examples 1-23 and the product destruction properties are shown in Table 1. Figure 1 The infrared spectrum of the PET cold-resistant toughening agent prepared in Example 6 is given.

[0147] Figure 1 It can be seen that the PET cold-resistant toughening agent obtained by the present invention has a triple peak absorption peak (1100cm -1 ), carbonyl absorption peak (1700cm -1 ), epoxy group absorption peak (900cm -1), indicating that there are epoxy groups in the PET cold-resistant toughening agent molecules. These epoxy groups can react with the carboxyl groups in the PET molecules during processing to introduce the cold-resistant agent into the PET molecules. 2934 and 2581 cm-1 are the characteristic absorption peaks of -CH3 and -CH2 groups. The introduction of these fatty chains into the PET molecules increases the flexibility of the PET molecules, thereby improving the molecular mobility of PET at low temperatures, increasing the low-temperature impact performance, and playing a role in cold resistance. As can be seen from Table 1, the impact strengths of PET and RPET at -20°C are 1.56 and 0.98 kJ / m respectively. 2 , the number of fast food boxes destroyed is 5. After adding 5-10% of cold-resistant additives to PET, the low-temperature impact resistance is greatly improved, and the number of fast food boxes destroyed is significantly reduced, and almost no fast food boxes are broken. This shows that the cold-resistant additives have a role in the cold resistance of PET, and the purpose of the present invention has been achieved.

[0148] Table 1: Low temperature impact properties of PET and RPET and product failure properties

[0149]

[0150]

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A PET cold-resistant toughening agent, characterized in that: Its structural formula is shown in molecular formula (1); 2. A method for synthesizing a PET cold-resistant toughening agent, characterized in that: The steps include: S1: 55-75 parts by weight of triglycidyl isocyanurate, 20-35 parts by weight of fatty diacid, and 3-5 parts by weight of liquid catalyst are placed in a pressure reactor, the stirring speed is 500r / min-1000r / min, the system temperature is controlled at 150℃-170℃, the nitrogen flow rate is 120mL / min-150mL / min, and the reaction is carried out for 3h-6h; S2: then add 3-5 parts by weight of aliphatic glycidyl ether epoxy resin and 0.2-0.5 parts by weight of super solid acid catalyst, and continue the reaction for 2h-3h; S3: Then add 10-20 parts by weight of fatty acid and 0.1-0.3 parts by weight of super solid acid catalyst, control the system temperature at 180°C-220°C, react for 3h-5h, and cool to obtain the auxiliary agent of the present invention.

3. The method for synthesizing a PET cold-resistant toughening agent according to claim 2, characterized in that: The fatty diacid is shown in formula (2); 4. The preparation method according to claim 2, characterized in that: The liquid catalyst is one or more of a single polyamine, a mixed polyamine or a modified polyamine.

5. The preparation method according to claim 2, characterized in that: The aliphatic glycidyl ether epoxy resin is one of 1,4-butanediol glycidyl ether and neopentyl glycol diglycidyl ether or a mixture of the two.

6. The preparation method according to claim 2, characterized in that: The fatty acid is shown in formula (3); 7. Application of a PET cold-resistant toughening agent in PET, characterized in that: The PET cold-resistant toughening agent is obtained by the preparation method according to any one of claims 2 to 6, and the added amount of the PET cold-resistant toughening agent is 5-10% of the mass of PET.

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