阅读说明：本技术 一种pet包装用高阻光母粒及其制备方法 (High-gloss master batch for PET packaging and preparation method thereof ) 是由 史修臣 郭洪江 于 2019-07-30 设计创作，主要内容包括：本发明提出一种PET包装用高阻光母粒及其制备方法,本发明以PET树脂为基础载体树脂,确保了阻光母粒与PET成品树脂的良好的相容性,又加入了一定量的PP树脂,提高了成品瓶中钛白粉含量偏高而导致的PET瓶胚及PET成品瓶偏脆的问题,钛白粉主要起到阻隔光线的效果,钛白粉具有很好的阻隔性,且纯白色的外观正好契合奶制品白色包装的需求,铝粉起到增亮效果,同时可以适度提高遮盖性和阻光性,食品接触级炭黑也起到一定的阻光性能,且能有效提高瓶胚的吸热性能,更容易吹瓶,并且可以在较低的温度下吹瓶,更节能更环保。(The invention provides a high-light-resistance master batch for PET packaging and a preparation method thereof, the invention takes PET resin as basic carrier resin, ensures good compatibility of the light-resistance master batch and PET finished product resin, adds a certain amount of PP resin, and improves the problem that the PET bottle blank and the PET finished product bottle are crisp due to high content of titanium dioxide in the finished product bottle.)

1. The high-gloss master batch for PET packaging is characterized by comprising PET resin, PP resin, titanium dioxide, aluminum powder and carbon black.

2. The high-light-resistance master batch for PET packaging according to claim 1, wherein the high-light-resistance master batch comprises the following components in percentage by weight: PET resin accounting for 10-50% of the total mass fraction; PP resin accounting for 1-10% of the total mass fraction; titanium dioxide accounting for 30-80% of the total mass fraction; aluminum powder accounting for 0.5-5% of the total mass fraction; carbon black accounting for 0.5 to 5 percent of the total mass fraction.

3. The high light-resistant master batch for PET packaging according to claim 1, wherein the viscosity of the PET resin is 0.4-0.8; the solvent index of the PP resin is 3-8; the titanium dioxide is in a rutile type; the particle size of the aluminum powder is 5-20 mu m; the particle size of the carbon black is 5-50 μm.

4. The preparation method of the high-light-resistance master batch for PET packaging is used for preparing the high-light-resistance master batch for PET packaging according to claim 1, and is characterized by comprising the following steps:

step 1: uniformly stirring PET resin, PP resin, titanium dioxide, aluminum powder and carbon black in a stirring kettle;

step 2: adding the mixed material into an extruder;

and step 3: adjusting the temperature of an extruder, melting the mixed material and then extruding;

and 4, step 4: the molten material to be extruded is stable;

and 5: cutting the molten material into particles;

step 6: stabilizing the particles to be cut;

and 7: checking and accepting the particles;

and 8: and drying and packaging the qualified product.

5. The method for preparing the high-gloss master batch for PET packaging according to claim 4, wherein in step 3, the temperature of the extruder is 220-260 ℃, and the temperature of the first-stage melting section and the temperature of the second-stage dispersing section can be properly increased by 5-10 ℃ to facilitate melting and dispersing.

6. The method for preparing the high light-resistant master batch for PET packaging according to claim 4, wherein in step 4, the melt is stable and is extruded and drawn into uniform and stable continuous filaments.

7. The method for preparing the high light-resistant master batch for PET packaging according to claim 4, wherein in the step 5, the molten material is cut into particles by means of water-through particle cutting or direct underwater particle cutting.

8. The method for preparing high light-resistant master batch for PET packaging according to claim 4, wherein in step 6, the particles are stable, in particular, the shape, size and color of the particles are in a stable and unchanged state after the particles are cooled.

9. The method for preparing the high-light-resistance master batch for PET packaging according to claim 4, wherein in the step 7, the acceptance standard of the particles is as follows: the light resistance reaches more than 99.9 percent, the appearance is regular, the particle size is uniform, and the particle size is preferably similar to the size of PET particles.

10. The method for preparing the high-gloss master batch for PET packaging according to claim 4, wherein in step 8, the qualified product is dried in a dehumidification dryer at 120 ℃ for 4-6 hours.

Technical Field

The invention relates to the technical field of food packaging materials, in particular to a high-gloss master batch for PET packaging and a preparation method thereof.

Background

The packaging of dairy products, including milk drinks or yoghurt products, is important to consider the protection of light and oxygen. The light has obvious influence on the milk product, the nutrient components in the milk are damaged by the light, unstable substances in the milk are excited to generate free radicals so as to accelerate the milk oxidation, and meanwhile, a plurality of nutrient components in the milk, such as vitamin A, vitamin B2 (riboflavin), vitamin D and amino acid, are lost due to the light. The most common reaction of milk under light conditions is the photo-induced oxidation of cysteine, which produces mercaptans, sulfides and dimethylsulfide, all of which can seriously affect milk taste and nutrition.

At present, the milk product package is generally transported, stored and sold in a cold chain mode or sold in a tetra Pak normal temperature mode. PET plastic packaging has its unique advantages: the bottle type design is diversified, the production efficiency is high, the bottle type injection molding machine can be commonly used with injection molding processing equipment of other beverages of food and beverage companies, and the repeated investment is avoided. However, the PET package has the characteristic of high light transmission, which is contrary to the requirement of high light resistance of milk products, so that high light resistance master batches are required to be added, and the light resistance is more than 99.9%.

At present, the yield of dairy products in China is nearly 3000 ten thousand tons, and if the dairy products are completely stored and transported by a cold chain, the problems of high energy consumption, short storage period, limited sales area and the like exist. The normal temperature tetra Pak packaging has the problems of large investment of production equipment, complex processing and manufacturing, incapability of recycling, influence on environmental protection and the like.

At present, enterprises have been internationally used for producing similar PET light-blocking master batches, which mainly comprise two types: one type is a mode of mixing various plastic materials such as PET, PS and PC, but the technical process is complex, finished particles are round, subsequent injection molding processing is not facilitated, the screw of the injection molding machine is easy to slip, and the bottle blank is soft and easy to collide and scratch, so that the appearance of the bottle body is influenced.

In the other type, pure PET is used as a carrier resin, the content of active ingredients is low, the dispersibility is not good, and the prepared bottle blank and the finished product bottle are brittle, so that the finished product bottle is easy to crack, and consumer complaints are caused;

meanwhile, the cost of import of the two imported light-blocking master batches is very high in China, and the PET light-blocking master batches which are highly approved by customers are independently developed according to the problems of the existing PET light-blocking master batches.

Disclosure of Invention

The invention aims to provide a high-light-resistance master batch for PET packaging, which is low in manufacturing cost, good in toughness and excellent in light resistance, and a preparation method thereof.

In order to achieve the purpose, the invention provides a high-gloss master batch for PET packaging, which comprises PET resin, PP resin, titanium dioxide, aluminum powder and carbon black.

Preferably, the content of each component of the high-light-resistance master batch is as follows: PET resin accounting for 10-50% of the total mass fraction; PP resin accounting for 1-10% of the total mass fraction; titanium dioxide accounting for 30-80% of the total mass fraction; aluminum powder accounting for 0.5-5% of the total mass fraction; carbon black accounting for 0.5 to 5 percent of the total mass fraction.

Preferably, the viscosity of the PET resin is 0.4 to 0.8; the solvent index of the PP resin is 3-8; the titanium dioxide is in a rutile type; the particle size of the aluminum powder is 5-20 mu m; the particle size of the carbon black is 5-50 μm.

The invention also provides a preparation method of the high-light-resistance master batch for PET packaging, which comprises the following steps:

step 1: uniformly stirring PET resin, PP resin, titanium dioxide, aluminum powder and carbon black in a stirring kettle;

step 2: adding the mixed material into an extruder;

and step 3: adjusting the temperature of an extruder, melting the mixed material and then extruding;

and 4, step 4: the molten material to be extruded is stable;

and 5: cutting the molten material into particles;

step 6: stabilizing the particles to be cut;

and 7: checking and accepting the particles;

and 8: and drying and packaging the qualified product.

Preferably, in step 3, the temperature of the extruder is 220 ℃ to 260 ℃, and the temperature of the first-stage melting section and the temperature of the second-stage dispersing section can be properly increased by 5 ℃ to 10 ℃ to facilitate melting and dispersing.

Preferably, in step 4, the melt is stable, i.e. the melt is extruded and drawn to form a uniform and stable continuous filament.

Preferably, in step 5, the molten material is pelletized by means of water pelletizing or direct underwater pelletizing.

Preferably, the particle stability is that the shape, size and color of the particle are in stable and unchangeable states after the particle is cooled.

Preferably, the acceptance criteria for the particles are: the light resistance reaches more than 99.9 percent, the appearance is regular, the particle size is uniform, and the particle size is preferably similar to the size of PET particles.

Preferably, the approved product is dried in a dehumidification dryer at 120 ℃ for 4-6 hours.

Compared with the prior art, the invention has the advantages that: the PET resin is used as the basic carrier resin, so that the good compatibility of the light-blocking master batch and the PET finished product resin is ensured, a certain amount of PP resin is added, the problem that the PET bottle blank and the PET finished product bottle are crisp due to the high content of titanium dioxide in the finished product bottle is solved, the titanium dioxide mainly plays a role in blocking light, the titanium dioxide has good blocking performance, the pure white appearance is just in accordance with the requirement of white packaging of milk products, the aluminum powder plays a role in brightening, the covering performance and the light blocking performance can be properly improved, the food contact grade carbon black also plays a certain light blocking performance, the heat absorption performance of the bottle blank can be effectively improved, bottle blowing is easier, bottle blowing can be carried out at a lower temperature, and the bottle blowing is energy-saving and environment-friendly.

Compared with the high-light-resistance master batch on the market, the high-light-resistance master batch has better light resistance performance under the same addition proportion, the physical property of the bottle body is more excellent, the toughness is better, the cost is lower, meanwhile, the preparation method is simple, the performance, the appearance and the size of the manufactured product are more stable, and the product percent of pass is greatly improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be further described below.

The invention provides a high-gloss master batch for PET packaging, which comprises PET resin, PP resin, titanium dioxide, aluminum powder and carbon black.

In this embodiment, the contents of the components of the high-resistance master batch are respectively: the PET resin accounts for 10-50% of the total mass fraction, the too little PET resin can cause difficult extrusion granulation, the too much PET resin can occupy the content of other components, the too little PET resin can not achieve the high-efficiency light-blocking effect, the difficult extrusion granulation can be caused, the too much PET resin can occupy the content of other components, and the high-efficiency light-blocking effect can not be achieved; the PP resin accounts for 1-10% of the total mass fraction, the toughness is reduced due to too little PP resin, the bottle blowing performance is influenced due to too little PP resin and the toughness is reduced due to too much PP resin, and the bottle blowing performance is influenced due to too much PP resin; titanium dioxide accounting for 30-80% of the total mass fraction, too little titanium dioxide content can cause reduction of light resistance performance, too high titanium dioxide content can cause difficulty in processing and influence on extrusion granulation, too little titanium dioxide content can cause reduction of light resistance performance, and too high titanium dioxide content can cause difficulty in processing and influence on extrusion granulation; the aluminum powder accounts for 0.5-5% of the total mass fraction, and the light-blocking performance is reduced due to too little aluminum powder content, the light-blocking performance is reduced due to too high aluminum powder content, the processing is difficult due to too high aluminum powder content, the metal feeling is too strong, and the processing is difficult and the metal feeling is too strong due to too high aluminum powder content; carbon black accounting for 0.5 to 5 percent of the total mass fraction.

In this example, the viscosity of the PET resin is 0.4 to 0.8; the solvent index of the PP resin is 3-8; the titanium dioxide is in a rutile type; the grain diameter of the aluminum powder is 5-20 μm; the particle size of the carbon black is 5-50 μm.

The invention also provides a preparation method of the high-light-resistance master batch for PET packaging, which comprises the following steps:

step 1: uniformly stirring PET resin, PP resin, titanium dioxide, aluminum powder and carbon black in a stirring kettle;

step 2: adding the mixed material into an extruder;

and step 3: adjusting the temperature of an extruder, melting the mixed materials and then extruding;

and 4, step 4: the molten material to be extruded is stable;

and 5: cutting the molten material into particles;

step 6: stabilizing the particles to be cut;

and 7: checking and accepting the particles;

and 8: and drying and packaging the qualified product.

In this embodiment, in step 3, the temperature of the extruder is 220 ℃ to 260 ℃, and the temperature of the first melting section and the temperature of the second dispersing section can be properly increased by 5 ℃ to 10 ℃ to facilitate melting and dispersing.

In this example, the melt in step 4 was stabilized as a uniform and stable continuous melt extrusion wire.

In this embodiment, in step 5, the molten material is pelletized by means of water pelletizing or direct underwater pelletizing.

In this embodiment, the particle stability is that the shape, size and color of the particle are stable and unchanged after the particle is cooled.

In this embodiment, the acceptance criteria for the particles are: the light resistance reaches more than 99.9 percent, the appearance is regular, the particle size is uniform, and the particle size is preferably similar to the size of PET particles.

In this embodiment, the high-gloss master batch for PET packaging, which includes PET resin, PP resin, titanium dioxide, aluminum powder and carbon black, is dried in a dehumidification dryer at 120 ℃ for 4-6 hours for the product that is qualified for acceptance.

In this embodiment, the contents of the components of the high-resistance master batch are respectively: PET resin accounting for 10-50% of the total mass fraction; PP resin accounting for 1-10% of the total mass fraction; titanium dioxide accounting for 30-80% of the total mass fraction; aluminum powder accounting for 0.5-5% of the total mass fraction; carbon black accounting for 0.5-5% of the total mass fraction has too little carbon black content, which can result in the reduction of light resistance, too high which can result in the reduction of light resistance and the influence of too little carbon black content on appearance, and too high which can result in the reduction of light resistance and the influence of too dark color on appearance.

In this example, the viscosity of the PET resin is 0.4 to 0.8; the solvent index of the PP resin is 3-8; the titanium dioxide is in a rutile type; the grain diameter of the aluminum powder is 5-20 μm; the particle size of the carbon black is 5-50 μm.

The invention also provides a preparation method of the high-light-resistance master batch for PET packaging, which comprises the following steps:

step 1: uniformly stirring PET resin, PP resin, titanium dioxide, aluminum powder and carbon black in a stirring kettle;

step 2: adding the mixed material into an extruder;

and step 3: adjusting the temperature of an extruder, melting the mixed materials and then extruding;

and 4, step 4: the molten material to be extruded is stable;

and 5: cutting the molten material into particles;

step 6: stabilizing the particles to be cut;

and 7: checking and accepting the particles;

and 8: and drying and packaging the qualified product.

In this embodiment, in step 3, the temperature of the extruder is 220 ℃ to 260 ℃, and the temperature of the first melting section and the temperature of the second dispersing section can be properly increased by 5 ℃ to 10 ℃ to facilitate melting and dispersing.

In this example, the melt in step 4 was stabilized as a uniform and stable continuous melt extrusion wire.

In this embodiment, in step 5, the molten material is pelletized by means of water pelletizing or direct underwater pelletizing.

In this embodiment, the particle stability is that the shape, size and color of the particle are stable and unchanged after the particle is cooled.

In this embodiment, the acceptance criteria for the particles are: the light resistance reaches more than 99.9 percent, the appearance is regular, the particle size is uniform, and the particle size is preferably similar to the size of PET particles.

In this example, the approved product was dried in a 120 ℃ dehumidification dryer for 4-6 hours

The technical effect of the present invention will be further explained by combining the specific embodiments with the data as follows:

in a normal-temperature yoghourt project of some client NF, the bottle weight is 22 g, the wall thickness is 0.36 mm, the self light-blocking master batch is added by 12 percent, the oxygen-blocking agent is 3 percent, the rest is PET resin, the light-blocking performance can reach 99.99 percent, and the toughness, physical property and other performance indexes of the bottle accord with the internal control standard of the client. The conventional PET bottle is completely transparent, the light resistance of the PET bottle added with 1% of common white oil is about 60%, and if the white oil is added too high, the screw rod can slip and the normal processing and production can not be realized. The customer tested a certain imported light blocking master batch, and the same 12% addition ratio, the drop test (2 m height free drop, no crack) was passed.

In the normal-temperature yogurt item of another customer YL, the bottle is 21 g, the wall thickness is 0.35 mm, 10 percent of the light-blocking master batch, 3 percent of the oxygen-blocking agent and the balance of PET resin are added, the light-blocking performance can reach 99.6 percent, and the toughness, physical property and other performance indexes of the bottle meet the internal control standard of the customer. The customer has used a certain imported light-blocking master batch with the same addition proportion, but the unit price is very high, and the product of my department can save more than one million yuan of material cost for the customer every year.

Therefore, compared with the high-light-resistance master batch on the market, the high-light-resistance master batch has better light resistance, the bottle body has more excellent material performance, better toughness and lower cost under the same addition proportion, meanwhile, the preparation method is simple, the manufactured product has more stable performance, appearance and size, the product qualification rate is greatly improved, compared with the high-light-resistance master batch on the market, the high-light-resistance master batch has better light resistance under the same addition proportion, the bottle body has more excellent material performance, better toughness and lower cost, meanwhile, the preparation method is simple, the manufactured product has more stable performance, appearance and size, and the product qualification rate is greatly improved.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.