CN-121975282-A - Transparent polyester injection molding and demolding master batch as well as preparation method and application thereof

Abstract

The invention relates to the technical field of injection molding and demolding master batches, in particular to a transparent polyester injection molding and demolding master batch, and a preparation method and application thereof. The lubricant comprises, by mass, 85-97% of a carrier and 3-15% of a lubricant, wherein the lubricant comprises, by mass, 2-6% of zinc crotonate, 1-4% of zinc cinnamate and stearyl stearate. Through the lubricant with specific component proportion, the fluidity and the mold release property of the polyester product are improved, and the haze is reduced.

Inventors

• SHEN ZHIGANG
• ZHENG YAO
• WEI BOYU
• XU HANSONG
• YANG LIPING
• XIAO HAIJUN
• He Shuaiwei
• SUN TENGXIAO

Assignees

• 万凯新材料股份有限公司

Dates

Publication Date

20260505

Application Date

20260407

Claims (10)

1. 1. The transparent polyester injection molding and demolding master batch is characterized by comprising, by mass, 85% -97% of a carrier and 3% -15% of a lubricant; The lubricant comprises (2-6) zinc crotonate, zinc cinnamate and stearyl stearate in a mass ratio of (2-6) to (1-4).
2. 2. The transparent injection molding and demolding master batch for polyester according to claim 1, wherein the carrier is PETG.
3. 3. The transparent polyester injection molding and demolding master batch according to claim 1, wherein the viscosity of the PETG is 0.6dL/g to 0.85dL/g.
4. 4. The transparent polyester injection molding and demolding master batch is characterized by further comprising a transparent compatibility promoter, wherein the mass ratio of the components is 85% -96% of carrier, 3% -14% of lubricant and 0.1% -1% of the transparent compatibility promoter.
5. 5. The transparent injection molding and demolding master batch of claim 4, wherein the transparent compatibility promoter comprises polyethylene glycol monomethyl ether methacrylate (PEGMA).
6. 6. A method for preparing a transparent polyester injection molding master batch, which is applied to the transparent polyester injection molding master batch of any one of claims 1 to 5, and is characterized by comprising the following steps: Weighing the components according to the proportion of the transparent polyester injection molding master batch according to any one of claims 1-5; And (3) after the carrier is dried in vacuum, adding the lubricant, and granulating to obtain the target polyester transparent injection molding master batch.
7. 7. The method for preparing transparent injection molding master batch for polyester according to claim 6, wherein said transparent compatibility promoter is further added after said lubricant is added and before granulating.
8. 8. The method for preparing the transparent polyester injection molding and demolding master batch according to any one of claims 6 to 7, wherein the vacuum drying is carried out for 3 to 6 hours under the conditions of-0.08 to-0.10 MPa and 70 to 80 ℃.
9. 9. The method for preparing the transparent polyester injection molding and demolding master batch according to any one of claims 6 to 7, wherein in the granulating process, the temperature of each section of screw is set to be 160-185-C, T2 at 190-210 ℃ and 215-230 ℃ respectively, the screw load is 20-40 kg/h, and the screw rotating speed is 200-500 rpm.
10. 10. The use of the transparent polyester injection molding and demolding master batch as claimed in any one of claims 1 to 5 for preparing a polyester product.

Description

Transparent polyester injection molding and demolding master batch as well as preparation method and application thereof Technical Field The invention relates to the technical field of injection molding and demolding master batches, in particular to a transparent polyester injection molding and demolding master batch, and a preparation method and application thereof. Background Polyethylene terephthalate (PET) and polyethylene terephthalate-1, 4-cyclohexanedimethanol ester (PETG) are important polyester materials, and are widely applied to the fields of cosmetic bottles, beverage bottles, plastic vacuum blood collection tubes and the like because of the advantages of high transparency, high strength, light weight and the like. When the injection molding is used for producing products with small parts and large flow length ratio and small wall thickness, the polyester material is required to have good flow property, easy demoulding and good appearance quality and dimensional stability, but the common polyester chips are difficult to achieve ideal processing requirements. At present, stearate, montanic acid, polyethylene glycol, polyester polyol, organic silicon resin and polyethylene wax are mainly added into a polyester carrier to improve fluidity so as to achieve the effect of easy demoulding, however, the lubricants have the problems of small molecular weight, unstable property, low high temperature resistance, easiness in improving the haze of polyester materials and the like, and the raw material proportion is complex, the production and manufacturing process is complex, and the operation procedure is complex. Accordingly, the conventional technology is in need of improvement. Disclosure of Invention In view of the above, the present invention aims to solve at least one of the technical problems in the related art to a certain extent, and therefore, the present invention provides a transparent polyester injection molding and demolding master batch, a preparation method and an application thereof, and the lubricant with specific component proportions improves the fluidity and demolding property of a polyester product and reduces the haze. In order to solve the technical problems, the invention is realized as follows: In a first aspect, the invention provides a transparent polyester injection molding and demolding master batch, which comprises, by mass, 85% -97% of a carrier and 3% -15% of a lubricant; The lubricant comprises (2-6) zinc crotonate, zinc cinnamate and stearyl stearate in a mass ratio of (2-6) to (1-4). Compared with the prior art, the method has the advantages that the metal salt and fatty acid ester synergistic lubrication system is constructed by limiting the accurate proportion of (2-6): (1-4), and the core pain point that the fluidity, the demolding property and the transparency of a single mixed lubricant in the prior art are difficult to consider is solved. The unsaturated double bond of zinc crotonate can damage the regularity of PET/PETG molecular chains, the melt viscosity is reduced, the aromatic ring structure of zinc cinnamate can enhance the lubrication and isolation effect with the surface of a mould, the long-chain alkyl of stearyl stearate can further reduce the friction coefficient, and the three can cooperatively improve the melt index of the polyester material and reduce the demoulding force. In addition, the molecular structures of the three lubricants and the polyester carrier have better compatibility, and the proportion is optimized, so that the three lubricants can be uniformly dispersed in the carrier, and the transparency of the product is greatly improved. Further, the carrier is PETG. Further, the viscosity of the PETG is 0.6 dL/g-0.85 dL/g. Further, the transparent compatibility promoter comprises, by mass, 85% -96% of a carrier, 3% -14% of a lubricant and 0.1% -1% of the transparent compatibility promoter. Compared with the prior art, the invention introduces the transparent compatibility promoter, further solves the problem of interfacial tension between the lubricant and the carrier, and realizes synchronous improvement of dispersion uniformity, transparency and storage stability. The transparent compatibility promoter can be used as a bridge, one end of the transparent compatibility promoter forms a hydrogen bond with an ester bond of PET/PETG, and the other end of the transparent compatibility promoter is compatible with a hydrophobic group of the lubricant, so that the dispersion particle size of the lubricant is reduced, and the transparency of the product is further improved. Further, the transparent compatibility promoter includes polyethylene glycol monomethyl ether methacrylate (PEGMA). In a second aspect, the invention provides a preparation method of a transparent polyester injection molding and demolding master batch, which is applied to the transparent polyester injection molding master batch and comprises the following steps: weighing the compone