阅读说明：本技术 一种瓶盖用聚乙烯组合物及其制备方法 (Polyethylene composition for bottle cap and preparation method thereof ) 是由 岑静芸 梁胜彪 蔡伟 苏肖群 莫益燕 于 2021-10-26 设计创作，主要内容包括：本发明属于聚乙烯树脂领域,具体涉及一种瓶盖用聚乙烯组合物及其制备方法。本发明瓶盖用聚乙烯组合物包括如下重量份的制备原料：乙烯丁烯线性聚乙烯树脂100份、抗氧剂0.04～0.08份、脱模剂0.06～0.12份、爽滑剂0.07～0.20份,爽滑剂由芥酸酰胺和油酸酰胺按照重量比(0.02～0.08):(0.05～0.12)复配而成。本发明将芥酸酰胺和油酸酰胺复配作为爽滑剂不仅降低了摩擦系数,同时降低生产成本；组分中的脱模剂不仅具有促进脱模的作用,还进一步改善了组合物的颜色外观；本发明以乙烯丁烯线性聚乙烯树脂为基础树脂,复配抗氧剂、脱模剂、爽滑剂等助剂,使得由本发明聚乙烯组合物制得的瓶盖同时具有低气味、良好的爽滑性和力学性能,具有较高的推广应用价值。(The invention belongs to the field of polyethylene resin, and particularly relates to a polyethylene composition for a bottle cap and a preparation method thereof. The polyethylene composition for the bottle cap comprises the following raw materials in parts by weight: 100 parts of ethylene butylene linear polyethylene resin, 0.04-0.08 part of antioxidant, 0.06-0.12 part of release agent and 0.07-0.20 part of slipping agent, wherein the slipping agent is prepared by compounding erucamide and oleamide according to the weight ratio of (0.02-0.08) to (0.05-0.12). According to the invention, erucamide and oleamide are compounded to be used as the slipping agent, so that the friction coefficient is reduced, and the production cost is reduced; the release agent in the components not only has the effect of promoting the release, but also further improves the color appearance of the composition; according to the invention, the ethylene-butylene linear polyethylene resin is taken as the base resin, and the antioxidant, the release agent, the slipping agent and other auxiliaries are compounded, so that the bottle cap prepared from the polyethylene composition disclosed by the invention has low odor, good slipping property and mechanical property, and higher popularization and application values.)

1. The polyethylene composition for the bottle caps is characterized by comprising the following raw materials in parts by weight: 100 parts of ethylene-butylene linear polyethylene resin, 0.04-0.08 part of antioxidant, 0.06-0.12 part of release agent and 0.07-0.20 part of slipping agent; the slipping agent is prepared by compounding erucamide and oleamide according to the weight ratio of (0.02-0.08) to (0.05-0.12).

2. The polyethylene composition for bottle caps according to claim 1, wherein the ethylene-butene linear polyethylene resin has a melt flow rate of 1.8 to 2.6g/10min and a density of 0.950 to 0.954g/cm, measured at 190 ℃ under a pressure of 2.16kg³。

3. The polyethylene composition for bottle caps according to claim 1, wherein the antioxidant is a phenolic antioxidant.

4. The polyethylene composition for bottle caps according to claim 3, wherein the phenolic antioxidant is octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

5. The polyethylene composition for bottle caps according to claim 1, wherein the release agent is zinc stearate.

6. The method for preparing a polyethylene composition for bottle caps according to any one of claims 1 to 5, comprising the steps of:

weighing and mixing ethylene-butylene linear polyethylene resin, an antioxidant, a release agent and a slipping agent in corresponding parts by weight, and then melting, blending, extruding and granulating in a screw extruder to obtain the polyethylene composition for the bottle cap.

7. The preparation method according to claim 6, wherein the screw rotation speed of the screw extruder is 160-280 rpm/min; the extrusion temperature is 180-220 ℃.

8. Use of the polyethylene composition for bottle caps according to any one of claims 1 to 5 for the preparation of food grade bottle caps.

9. Use according to claim 8, wherein the food grade caps comprise juice caps, tea caps.

Technical Field

The invention belongs to the field of polyethylene resin, and particularly relates to a polyethylene composition for a bottle cap and a preparation method thereof.

Background

The beverage packaging market potential in China is huge, the annual demand of bottle cap materials can reach more than ten thousand tons, the current polyethylene bottle cap materials mainly depend on imported materials, and the gap of products in the field is large in China. The high-density polyethylene bottle cap material used in China comprises grades such as C910A/B/C special for tea drinks, C911A special for water drinks and fruit juices, C220A and C410A special for carbonated drinks, M80064 of Saibek, 2700J of Hunan petrochemical industry, HS5331H of Basel and the like.

The domestic market is mainly imported products, a large market space exists, the domestic developed bottle cap materials comprise products such as Yanshan 3300J, blue L5202 and L5201, but compared with the imported products, the domestic similar products are low in yield and poor in performance, such as bad smell, smooth effect, poor mechanical property and the like, so that the polyethylene bottle cap materials which are low in smell, excellent in performance and suitable for filling fruit juice beverages are developed, a part of the domestic market can be occupied, and better benefits are created.

Disclosure of Invention

The present invention is directed to a polyethylene composition for bottle caps and a method for preparing the same, which are directed to problems in the prior art, and a bottle cap prepared from the polyethylene composition for bottle caps according to the present invention has low odor and good slip and mechanical properties.

Based on the above purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a polyethylene composition for bottle caps, comprising the following raw materials, by weight: 100 parts of ethylene-butylene linear polyethylene resin, 0.04-0.08 part of antioxidant, 0.06-0.12 part of release agent and 0.07-0.20 part of slipping agent; the slipping agent is prepared by compounding erucamide and oleamide according to the weight ratio of (0.02-0.08) to (0.05-0.12).

Erucamide has better surface polarity effect because of containing longer unsaturated C22 chain and polar amido in the molecular structure, erucamide performance is more stable, the effect is slower, the price is higher, while oleamide is a nonionic surfactant, also called 9-octadecanoyl acid amide, because the molecular weight is smaller than erucamide, the effect is quicker, the price is lower, but the color and the stability are slightly worse; according to the invention, the oleic acid amide and the erucic acid amide are compounded, so that the polyethylene composition has good slipping performance, the odor of the slipping agent is favorably improved, and the production cost is reduced. Through a large number of experiments, the inventor finds that the oleic acid amide produced in the British grass has a light cream fragrance, and the oleic acid amide is beneficial to improving the smell of the bottle cap material compared with the heavy oil smell of the domestic oleic acid amide. The oleic acid amide of the present invention is preferably oleic acid amide produced in Poa British.

The release agent in the components has the effect of promoting the release and further improves the color appearance of the composition, and the bottle cap prepared from the polyethylene composition for the bottle cap has low odor, good smoothness and mechanical properties, such as tensile yield strength up to 26MPa and bending modulus up to 931MPa, by taking ethylene-butylene linear polyethylene resin as base resin and compounding with an antioxidant, the release agent, a slip agent and other auxiliaries.

Further, the ethylene-butylene linear polyethylene resin has a melt flow rate of 1.8 to 2.6g/10min and a density of 0.950 to 0.954g/cm measured at 190 ℃ under a pressure of 2.16kg³。

The ethylene butylene linear polyethylene resin is preferably LLDPE DMDB-8902 powder produced by Middling chemical Ministry of China, and compared with other low-density ethylene butylene polyethylene resins, the polyethylene resin for the bottle cap prepared from the ethylene butylene polyethylene resin has better mechanical property and is suitable for preparing the bottle cap.

Further, the antioxidant is a phenolic antioxidant.

Further, the phenolic antioxidant is octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

Further, the release agent is zinc stearate.

According to the invention, zinc stearate is used as a release agent, so that the polyethylene composition disclosed by the invention has good release performance, the color of the composition can be further improved, and the polyethylene composition is suitable for bottle caps of beverage bottles such as fruit juice beverages and tea beverages.

In a second aspect, the present invention provides a method for preparing the polyethylene composition for bottle caps, comprising the steps of:

weighing and mixing ethylene-butylene linear polyethylene resin, an antioxidant, a release agent and a slipping agent in corresponding parts by weight, and then melting, blending, extruding and granulating in a screw extruder to obtain the polyethylene composition for the bottle cap.

Further, the screw rotating speed of the screw extruder is 160-280 rpm/min; the extrusion temperature is 180-220 ℃.

In a third aspect, the invention provides an application of the polyethylene composition for bottle caps in preparation of food-grade bottle caps.

Further, the food-grade bottle cap comprises a fruit juice beverage bottle cap and a tea beverage bottle cap.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, erucamide and oleamide are compounded to be used as the slipping agent, so that the friction coefficient is reduced, and the production cost is reduced; the release agent in the components not only has the effect of promoting the release, but also further improves the color appearance of the composition; according to the invention, the ethylene-butylene linear polyethylene resin is taken as the base resin, and the antioxidant, the release agent, the slipping agent and other auxiliaries are compounded, so that the bottle cap prepared from the polyethylene composition disclosed by the invention has low odor, good slipping property and mechanical property, and higher popularization and application values.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples. It will be understood by those skilled in the art that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The test methods used in the examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are commercially available unless otherwise specified.

Example 1

The embodiment provides a polyethylene composition for a bottle cap, which comprises the following raw materials in parts by weight: 100 parts of ethylene butylene linear polyethylene resin, 0.06 part of antioxidant, 0.10 part of mold release agent, 0.03 part of erucamide and 0.12 part of oleamide. Wherein the ethylene butylene linear polyethylene resin is preferably LLDPE DMDB-8902 powder produced by Miyashi Miyao Mingdian, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ and under the pressure of 2.16kg³。

The antioxidant is a phenolic antioxidant, preferably octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate; the release agent is preferably zinc stearate. The erucamide is preferably erucamide from Poa British, and the oleamide is preferably oleamide from Poa British.

The present invention also provides a method for preparing the polyethylene composition for bottle caps, comprising the following steps:

accurately weighing the raw materials in parts by weight, fully mixing the raw materials in a high-speed mixer for 3-6 min to obtain a mixture, adding the mixture into a screw extruder, controlling the temperature of the screw extruder and a die head to be 180-220 ℃ and the rotating speed of the screw to be 160-280 rpm/min, plasticizing, melting, blending, extruding and granulating the mixture to obtain the polyethylene composition for the bottle cap.

Example 2

This example is different from example 1 only in that the polyethylene composition for bottle caps was prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.05 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.08 part of release agent zinc stearate, 0.03 part of erucamide and 0.09 part of oleamide.

The ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, and has a melt flow rate of 1.8-2.6 g/10min and a density of 0 measured at 190 ℃ and under a pressure of 2.16 kg.950～0.954g/cm³. The erucamide is preferably erucamide from Poa British, and the oleamide is preferably oleamide from Poa British.

Example 3

This example is different from example 1 only in that the polyethylene composition for bottle caps was prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.05 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.09 part of release agent zinc stearate, 0.06 part of erucamide and 0.09 part of oleamide.

Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³. The erucamide is preferably erucamide from Poa British, and the oleamide is preferably oleamide from Poa British.

Example 4

This example is different from example 1 only in that the polyethylene composition for bottle caps was prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.06 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.10 part of release agent zinc stearate, 0.08 part of erucamide and 0.08 part of oleamide.

Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³. The erucamide is preferably erucamide from Poa British, and the oleamide is preferably oleamide from Poa British.

Example 5

This example is different from example 1 only in that the polyethylene composition for bottle caps was prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.08 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.12 part of release agent zinc stearate, 0.08 part of erucamide and 0.06 part of oleamide.

Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³. The erucamide is preferably erucamide from Poa British, and the oleamide is preferably oleamide from Poa British.

Comparative example 1

The comparative example 1 is different from the example 5 in that the raw material of the ethylene-butene linear polyethylene resin is different and the rest components are the same. The ethylene-butylene polyethylene resin used in the comparative example is LLDPE DFDA-7042 powder produced by Mitsubishi Maofengshi company, the melt flow rate is 1.4-2.6 g/10min and the density is 0.918-0.922 g/cm measured at 190 ℃ and under the pressure of 2.16kg³。

The preparation method of the polyethylene resin of the comparative example line comprises the following steps: fully mixing 100 parts by weight of ethylene butylene linear polyethylene resin, 0.08 part by weight of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.12 part by weight of release agent zinc stearate, 0.12 part by weight of erucamide and 0.06 part by weight of oleamide in a high-speed stirrer for 3-6 min to obtain a mixture, adding the mixture into a screw extruder, controlling the temperature of the screw extruder and a die head to be 170-215 ℃ and the rotating speed of the screw to be 160-280 rpm/min, plasticizing, melting, blending, extruding and granulating to obtain the polyethylene resin of the comparative example.

Comparative example 2

The difference between the comparative example and the example 2 is only that the preparation raw materials of the polyethylene resin are different, which is mainly shown in that the slipping agent in the comparative example is a single component, and the slipping agent in the comparative example is oleamide.

The polyethylene resin in the comparative example is prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin and eighteen antioxidants0.05 part of alkyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.08 part of release agent zinc stearate and 0.12 part of oleamide. Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³。

Comparative example 3

The difference between the comparative example and the example 2 is only that the preparation raw materials of the polyethylene resin are different, which is mainly shown in that the slipping agent in the comparative example is a single component, and the slipping agent in the comparative example is erucamide.

The polyethylene resin in the comparative example is prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.05 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.08 part of release agent zinc stearate and 0.12 part of erucamide. Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³。

Comparative example 4

The comparative example is different from example 2 only in the preparation raw material of the polyethylene resin, mainly in that the release agent is not contained in the preparation raw material of the comparative example.

The polyethylene resin in the comparative example is prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.05 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.03 part of erucamide and 0.09 part of oleamide. Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³。

Comparative example 5

The difference between the comparative example and the examples 1-5 is that the raw materials for preparing the polyethylene resin of the comparative example do not contain an antioxidant, a release agent, oleamide and erucamide.

The polyethylene resin of the comparative example is prepared by extruding and granulating ethylene butylene linear polyethylene resin in a screw extruder with the extrusion temperature of 180-220 ℃ and the screw rotation speed of 160-280 rpm/min. Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³。

Comparative example 6

The comparative example is different from example 2 only in the preparation raw material of the polyethylene resin, and the main difference is that the oleamide in the preparation raw material of the comparative example is oleamide of a certain brand made in China.

The polyethylene resin in the comparative example is prepared from the following raw materials in parts by weight:

100 parts of ethylene butylene linear polyethylene resin, 0.05 part of antioxidant octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 0.03 part of erucamide and 0.09 part of oleamide. Wherein the ethylene butylene linear polyethylene resin is LLDPE DMDB-8902 powder produced by Mitsubishi Maofen company, the melt flow rate is 1.8-2.6 g/10min and the density is 0.950-0.954 g/cm measured at 190 ℃ under the pressure of 2.16kg³。

The properties of the polyethylene resins obtained in examples 1 to 5 and comparative examples 1 to 6 were measured by referring to the methods specified in the relevant standards, and the results are shown in table 1, and it can be seen from table 1 that the polyethylene compositions obtained from the components of the present invention are superior in odor and creamy in taste to those of comparative examples 1 to 6; the yellow index is low, which indicates that the bottle cap prepared by the composition has better appearance color; the oxidation induction period is relatively high, which shows that the composition has better oxidation resistance; more importantly, the bottle cap prepared from the composition has low friction coefficient and good smoothness; and the tensile yield strength and the flexural modulus are higher, which shows that the composition has excellent mechanical properties.

Comparative example 1 differs from example 5 only in that the composition differs from the ethylene-butene linear polyethylene resinThe ethylene-butene linear polyethylene resin of example 5 has a melt rate of 1.8 to 2.6g/10min and a density of 0.950 to 0.954g/cm³The ethylene-butene linear polyethylene resin in comparative example 1 has a melt rate of 1.4 to 2.6g/10min and a density of 0.918 to 0.922g/cm³The improvement of the mechanical properties of the embodiment 5 is more obvious, for example, the tensile yield strength is improved by 1.15 times, and the flexural modulus is improved by 1.81 times. And the friction coefficient of the embodiment 5 is also reduced, which shows that the embodiment 5 has better slip property.

Comparative examples 2 and 3 are different from example 2 only in that comparative examples 2 and 3 are both single-component slipping agents, and example 2 is compounded by two slipping agents, namely erucamide and oleamide, so that the friction coefficient of example 2 is relatively low, and the erucamide and oleamide are compounded to have better slipping performance.

Comparative example 4 is different from example 2 only in that the components of comparative example 4 do not contain the release agent, and it can be seen that the yellow index of comparative example 4 is obviously increased, the friction coefficient is inferior to that of comparative example 4, and the release agent not only has the self-releasing effect, but also can effectively improve the appearance and color of the polyethylene composition.

Comparative example 5 is different from example 2 in that the composition of comparative example 5 does not contain antioxidant, slipping agent and release agent components, and as can be seen from the results in table 1, the appearance, oxidation resistance, slipping property and smell of the bottle cap prepared from the composition are obviously improved by adding the above-mentioned additives.

Comparative example 6 differs from example 2 only in that the oleamide in the component of comparative example 4 is a home-made brand of oleamide, the adjuvant has a pungent greasy odor, and comparative example 6 is prepared with a significant heavy greasy odor. As can be seen from the results in table 1, the oleic acid amide added in example 2 of the present invention is a large oleic acid amide, which is effective in improving odor, compared to comparative example 6.

TABLE 1 Properties of polyethylene resins of examples 1 to 5 and comparative examples 1 to 6

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.