Polyester copolymer with hindered amine group-containing main chain and preparation method thereof

Abstract

The invention provides a polyester copolymer with hindered amine group-containing main chain, polycondensation is carried out for aromatic acids, aliphatic diols and 1-(2'-hydroxyethyl)-2,2,6,6-tetramethyl-4-pipradrol, wherein, the mol ratio between 1-(2'-hydroxyethyl)-2,2,6,6-tetramethyl-4-pipradrol and aliphatic diols is (0.1:99.9)-(20:80). The aromatic acids contain terephthalic acid and 2,6-naphthalenedicarboxylic acid, and the aliphatic diols contain glycol, propylene glycol, butylene glycol or cyclohexanediol. Compared with the prior art, the invention has the advantages that the polyester copolymer of the present invention has excellent ultraviolet light stability of the hindered amine compound, simultaneously has excellent mechanical properties, and overcomes the disadvantage that in the prior art after the polyester is added with the hindered amine light stabilizing agent, the mechanical properties decrease.

Description

technical field [0001] The invention relates to a polyester copolymer with hindered amine groups in the main chain with high ultraviolet light stability. Background technique [0002] Hindered amine light stabilizer (HALS) is a compound with 2,2,6,6-tetramethylpiperidine group in its molecular structure. Wide range of applications. At the same time, adding the hindered amine light stabilizer and the ultraviolet light absorber to the polymer material can produce a significant synergistic effect, thereby greatly improving the anti-ultraviolet light performance of the polymer material. Common hindered amine light stabilizers include small molecule compounds and polymer types. The following formulas give the molecular structural formulas of some commonly used hindered amine light stabilizers. Among them, small molecule hindered amine light stabilizers such as GW-770 and GW-540 have poor heat resistance, are easy to volatilize when the processing temperature is relatively high...

AI Technical Summary

Problems solved by technology

[0005] However, when the above-mentioned hindered amine light stabilizers are used in polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), there are obvious disadvantages

For example, hindered amine light stabilizers containing active hydrogen (such as light stabilizer 770, 944, etc.) are likely to cause significant degradation of polyester during processing; GW-540 and GW-622 do not contain active hydrogen, but are compatible with polyester Poor capacity, when the added amount is high (such as the weight percentage is greater than 1%), the mechanical properties of polyester products will be significantly reduced

Although GW-622 belongs to polyester polymer, it is composed of aliphatic dibasic acid and 1-(2'-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol The oligomer formed by polycondensation has a relatively low molecular weight (3000-4000), and the compatibility with PET is not ideal, resulting in a decrease in the mechanical properties of polyester and is easy to hydrolyze

At the same time, GW-622 has poor heat resistance, for example, it will produce about 3% thermal weight loss when heated to 280 degrees

Therefore, GW-622 is difficult to meet the use requirements of PET

Images