Use of poly(4-methyl-1-pentene) in the preparation of packaging materials with oxygen absorption function and composition and functional masterbatch

Abstract

The application relates to application of poly(4-methyl-1-pentene) in preparation of packaging materials with oxygen absorption function, and a composition and a functional master batch. The composition provided by the application comprises poly(4-methyl-1-pentene) and a cobalt salt, and the mass ratio of the two is 1:1-99:1. The application also provides a functional master batch with raw materials comprising the above composition. The application also provides a packaging bottle raw material composition comprising polyethylene terephthalate and the above functional master batch, and a packaging bottle prepared therefrom. The technical scheme of the application greatly improves the oxygen absorption persistence, prolongs the oxygen absorption time limit of the packaging, and under the same or even lower addition amount, the oxygen absorption time persistence of the overall packaging is much higher than that of the traditional formula.

Description

Technical Field

[0001] This invention relates to the application of poly(4-methyl-1-pentene) in the preparation of packaging materials with oxygen-absorbing function, as well as compositions, functional masterbatches, and packaging bottles, belonging to the field of packaging material technology. Background Technology

[0002] With the development of the beverage industry, PET packaging and aseptic filling equipment have emerged and are now widely used in the dairy and other beverage industries. PET packaging boasts high mechanical strength, versatile shapes, and the ability to be repeatedly opened and closed, making it easy to carry.

[0003] To use PET packaging for light- and oxygen-sensitive contents, appropriate additives are needed to achieve light and oxygen barrier functions. Current methods involve adding additives that provide light and oxygen barrier functions, such as light-blocking masterbatches and oxygen-blocking masterbatches, to prevent external light and oxygen from entering. However, these methods are ineffective against oxygen already inside the PET packaging or oxygen pre-dissolved in the contents, which may still cause oxidation problems. Summary of the Invention

[0004] In the process of researching technical solutions to improve the light-blocking function of PET packaging, the inventors of this invention discovered that poly(4-methyl-1-pentene) (PMP) has good light-blocking properties when it is compounded with the parent resin of PET packaging. They also unexpectedly discovered that after adding PMP, under the catalysis of cobalt salt, the PET packaging not only has the function of blocking light, but also reduces the amount of oxygen inside the packaging. Analysis revealed that this is because PMP absorbs some oxygen.

[0005] Based on the above findings, this invention proposes the application of PMP in the preparation of packaging materials with oxygen-absorbing functions.

[0006] According to a specific embodiment of the present invention, preferably, the PMP is produced by reacting tertiary hydrocarbons and / or methylene hydrogens with oxygen under the catalysis of cobalt salt. Tertiary hydrocarbons and methylene hydrogens have low activation energies and can react with oxygen, thus absorbing oxygen. By adding an appropriate cobalt salt as a catalyst (allowing the PMP to react with oxygen in the presence of cobalt salt to achieve its oxygen absorption function), the PMP can better perform its oxygen absorption function.

[0007] According to a specific embodiment of the present invention, preferably, the packaging material is PET. This packaging material can be a PET bottle.

[0008] This invention also provides a composition with oxygen-absorbing function, wherein the composition comprises PMP and cobalt salt in a mass ratio of 1:1-99:1, preferably 15:1-90:1, and more preferably 30:1-60:1. This composition, when used as a raw material in PET lamination, can act as a whitening and light-blocking agent during PET molding, while also providing oxygen absorption. This results in packaging materials that possess both light-blocking and oxygen-absorbing functions, continuously absorbing oxygen from inside the packaging during use (e.g., oxygen dissolved in the packaging contents and released during storage, oxygen present in the top space of the packaging), preventing oxidation of the contents. While the packaging can block most oxygen from entering, some oxygen may still permeate into the packaging during prolonged use and storage. The composition provided by this invention can also absorb this oxygen that permeates from the external environment through the packaging, thereby reducing or completely preventing oxygen from penetrating the packaging and entering its interior.

[0009] According to a specific embodiment of the present invention, preferably, the cobalt salt used in the present invention includes cobalt neodecanoate and / or cobalt stearate, etc.

[0010] According to a specific embodiment of the present invention, preferably, the composition further contains polybutadiene and / or styrene-butadiene-styrene copolymer (SBS). The addition of polybutadiene and SBS can have a synergistic effect on oxygen absorption. Both polybutadiene and SBS molecular chains contain a large number of unsaturated conjugated double bonds and allyl hydrogens, both of which can react with oxygen. In the SBS triblock polymer, the polybutadiene segments can be selected in different conformations, such as 1,2 copolymer and 1,4 copolymer. These two conformations have different oxygen absorption rates. The balance between the oxygen absorption rate and persistence of the oxygen-absorbing formulation can be adjusted by regulating the ratio of the two different SBS polymer conformations.

[0011] According to a specific embodiment of the present invention, preferably, the mass ratio of polybutadiene and / or SBS to PMP is 50:1-10:1, more preferably 30:1-10:1, and even more preferably 20:1-12:1.

[0012] This invention also provides a masterbatch with synergistic light-blocking and oxygen-absorbing functions, the raw materials of which include the composition provided by this invention. The addition of PMP to this masterbatch not only provides light-blocking functionality but also oxygen-absorbing functionality.

[0013] According to a specific embodiment of the present invention, preferably, the raw materials of the functional masterbatch further include titanium dioxide and carbon black; titanium dioxide and carbon black can improve the light-blocking performance of the functional masterbatch.

[0014] According to a specific embodiment of the present invention, preferably, the raw materials of the functional masterbatch, by weight percentage, include: poly(4-methyl-1-pentene), 5.0-90.0%, titanium dioxide, 0-60.0% (0% or less than 60.0%), cobalt salt, 0.3-5.0%, and carbon black, 0-1.0% (0% or less than 1.0%).

[0015] According to a specific embodiment of the present invention, preferably, the raw materials of the functional masterbatch, by weight percentage, include: poly(4-methyl-1-pentene), 29.0-40.0%, titanium dioxide, 0-15.0% (0% or less than 15.0%), cobalt salt, 0.4-2.5%, and carbon black, 0.055-0.06%.

[0016] According to a specific embodiment of the present invention, preferably, the raw materials of the functional masterbatch further include: PET 0-80.0% (0% or less than 80.0%), polybutadiene 1.0-20.0%, styrene-butadiene-styrene copolymer 0-25.0% (0% or less than 25.0%), and compatibilizer 0-5.0% (0% or less than 5.0%); more preferably, the raw materials of the light-blocking masterbatch further include: PET 0-55.0% (0% or less than 55.0%), polybutadiene 5.0-15.0%, styrene-butadiene-styrene copolymer 0-10.0% (0% or less than 10.0%), and compatibilizer 1.0-3.0%. By adding a compatibilizer, the compatibility between PMP and the parent resin (e.g., PET resin) of the packaging bottle can be controlled to a suitable level. If the compatibility is too good, the dispersion size of PMP in the parent resin (e.g., PET resin) will be too small, which will lead to a decrease in light blocking performance (e.g., complete compatibility or the dispersed phase reaching the nanoscale, in which case the system is transparent). Moreover, during the process of preparing packaging bottles using preform stretching, if the compatibility is too good, it will be difficult to form voids between the parent resin (e.g., PET resin) and PMP, which is also detrimental to its light blocking performance. The compatibility can be controlled by controlling the grafting rate of the PMP grafted polymer. Preferably, the grafting rate of the PMP grafted polymer is 0.1%-0.8%; more preferably, the grafting rate is 0.1%-0.5%, and even more preferably 0.2%-0.3%. The compatibilizer described above is a compound capable of providing grafting monomers, which include one or more of maleic anhydride (MAH), acrylic acid, methacrylic acid, and glycidyl methacrylate.

[0017] Applying the functional masterbatch provided by this invention to PET bottles can protect contents that are sensitive to ultraviolet / visible light and oxygen.

[0018] The present invention also provides a packaging bottle raw material composition comprising polyethylene terephthalate and the functional masterbatch provided by the present invention.

[0019] According to a specific embodiment of the present invention, preferably, the content of the functional masterbatch is 0.5-15.0% and the content of the polyethylene terephthalate is 85.0-99.5% based on the total weight of the raw material composition of the packaging bottle.

[0020] According to a specific embodiment of the present invention, preferably, the content of the functional masterbatch is 3.0-6.5% and the content of the polyethylene terephthalate is 93.5-97.0% based on the total weight of the raw material composition of the packaging bottle.

[0021] The present invention also provides a packaging bottle made from the above-mentioned packaging bottle raw material composition.

[0022] According to a specific embodiment of the present invention, preferably, the bottle body is made of the above-mentioned packaging bottle raw material composition.

[0023] Compared with existing technologies that add light-blocking and oxygen-absorbing agents simultaneously or separately, the technical solution of the present invention has the following advantages:

[0024] (1) Simplified addition and ingredients: The original two additives have been reduced to one, making the quality easier to control;

[0025] (2) The amount added is greatly reduced: the existing technology requires 10% light blocking masterbatch + 3% oxygen absorbing masterbatch, while the present invention only requires 6.5% functional masterbatch to achieve the same light blocking and oxygen blocking effect.

[0026] (3) The duration of oxygen absorption is greatly improved, extending the time for oxygen absorption by the packaging. In traditional oxygen-absorbing formulations, the amount of double-bonded substances added as the main oxygen-absorbing component is relatively low (too high a amount will affect the overall performance of the material). However, this invention uses PMP, which has both light-blocking and oxygen-absorbing functions. Therefore, with the same or even lower addition amount, the duration of oxygen absorption by the overall packaging is much longer than that of traditional formulations. Attached Figure Description

[0027] Figure 1 A schematic diagram of the device used for light-blocking testing. Detailed Implementation

[0028] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0029] Example 1

[0030] This embodiment provides a composition that combines light blocking and oxygen absorption functions, comprising PMP and cobalt salt in a mass ratio of 35:1.5, 50:1.5, 85:1.5, or 88.5:1.5.

[0031] The cobalt salt is either cobalt stearate or cobalt neodecanoate.

[0032] Example 2

[0033] This embodiment provides a set of masterbatches that can achieve synergistic light blocking and oxygen absorption functions, the composition of which is shown in Table 1:

[0034] Table 1

[0035] PMP compatibilizer PET Cobalt stearate New cobalt sulfate Polybutadiene SBS Masterbatch 1 88.5 0 1.5 10 Masterbatch 2 88.5 1.5 10 Masterbatch 3 88.5 1.5 10 Masterbatch 4 35 53.5 1.5 10 Masterbatch 5 50 38.5 1.5 10 Masterbatch 6 85 3.5 1.5 10 Masterbatch 7 88.5 1.5 5 5

[0036] The compatibilizers in Table 1 are polyolefins (polyethylene, polypropylene, poly(4-methyl-1-pentene), etc.) grafted with polar monomers such as maleic anhydride / acrylic acid / glycidyl acrylate.

[0037] The oxygen uptake values ​​of masterbatches 1-7 were tested as follows:

[0038] (1) The masterbatch is freeze-ground and passed through a 60-mesh sieve. 1g of powder material is weighed and placed in a sealed glass container.

[0039] (2) Using a non-destructive oxygen content tester, the oxygen content in the glass container is tested every 1 hour until the data does not change significantly. The difference is the oxygen uptake value of the material.

[0040] The specific test results are shown in Table 2:

[0041] Table 2

[0042] Oxygen uptake value (cc / g) Masterbatch 1 170.3 Masterbatch 2 43.2 Masterbatch 3 23.2 Masterbatch 4 87.8 Masterbatch 5 103.5 Masterbatch 6 173.4 Masterbatch 7 168.5

[0043] As shown in Table 2, comparing masterbatch 1 with masterbatches 2 and 3, it can be seen that the oxygen absorption capacity of the PMP-containing formulation far exceeds that of traditional PET carrier formulations. Furthermore, the incompatibility between PMP and PET provides additional light-blocking protection for PET packaging. In contrast, similar products widely used in the market, tested using the same method, have oxygen absorption capacities between 8-15 cc / g, significantly lower than the technical solution provided in this invention.

[0044] Example 3

[0045] This embodiment provides a set of PET bottles, the raw material composition of the bottle body, the light blocking rate test results, the bottle body OTR, etc. are shown in Table 3.

[0046] Table 3

[0047]

[0048]

[0049] OTR refers to oxygen permeability, which can be measured using a barrier PET bottle OTR rapid tester.

[0050] As shown in Table 3, comparing PET bottles numbered 1 and 2, masterbatch 1, containing PMP, not only provides excellent oxygen barrier properties but also offers some light-blocking benefits. When combined with a certain amount of TiO2, its light-blocking rate reaches 99.2% (PET bottle number 4), while at the same TiO2 content (PET bottle number 3), the visible light transmittance is only 92%, indicating that PMP plays a significant synergistic role in improving light-blocking performance. Masterbatch 6, by adding a compatibilizer component, further reduces the dispersed phase size of PMP, thereby increasing the phase area between PMP and PET. With the same addition amount, its light-blocking rate is further increased to 99.9% compared to PET bottle number 3.

[0051] In addition to its excellent light-blocking effect, the bottle's OTR is only 0.00031-0.00036 cc / day·atm·pak, which also provides good oxygen barrier properties.

[0052] The method for testing light obscuration is as follows:

[0053] (1) Ultraviolet light part: Take a sheet sample with a size of 3.5cm×3.5cm from the fixed part of the bottle. The test equipment is a Datacolor 850 benchtop spectrophotometer. The UV-VIS transmittance test is carried out in accordance with the AATCC TM203-2016e standard and the light source is a Pulsed xenonlight source.

[0054] (2) Visible light portion: Overall light blocking test was conducted using the following method: Figure 1 The device shown performs:

[0055] The device is a sphere (radius r = 50 cm). The light source is enclosed inside a PET bottle, and a sample holder is placed at the center of the sphere. The transmitted light is collected through a light outlet on the sphere, and the light blocking rate is calculated using the following formula:

[0056] T = (I0 - I1) / I0

[0057] Where T represents the light blocking rate, I0 represents the light source intensity, and I1 represents the transmitted light intensity.

Claims

1. A masterbatch capable of synergistic light blocking and oxygen absorption, wherein, The raw materials for this functional masterbatch include poly(4-methyl-1-pentene) and cobalt salt, with a mass ratio of 15:1 to 90:

1. By weight percentage, the raw materials of this functional masterbatch include: 5.0-90.0% poly(4-methyl-1-pentene), 0-60.0% titanium dioxide, 0.3-5.0% cobalt salt, and 0-1.0% carbon black; The raw materials of the functional masterbatch also include: PET 0-80.0%, polybutadiene 1.0-20.0%, styrene-butadiene-styrene copolymer 0-25.0%, and compatibilizer 0-5.0%; The poly(4-methyl-1-pentene) achieves its oxygen absorption function through the reaction of tertiary hydrocarbons and / or methylene hydrogens with oxygen under the catalysis of cobalt salt.

2. The functional masterbatch according to claim 1, wherein, The mass ratio of poly(4-methyl-1-pentene) to cobalt salt is 30:1-60:

1.

3. The functional masterbatch according to claim 1, wherein, The cobalt salts include cobalt neodecanoate and / or cobalt stearate.

4. The functional masterbatch according to claim 1, wherein, By weight percentage, the raw materials of this functional masterbatch include: poly(4-methyl-1-pentene), 29.0-40.0%, titanium dioxide, 0-15.0%, cobalt salt, 0.4-2.5%, and carbon black, 0.055-0.06%.

5. The functional masterbatch according to claim 4, wherein, The raw materials for this functional masterbatch also include: PET 0-55.0%, polybutadiene 5.0-15.0%, styrene-butadiene-styrene copolymer 0-10.0%, and compatibilizer 1.0-3.0%.

6. A packaging bottle raw material composition comprising polyethylene terephthalate and the functional masterbatch according to any one of claims 1-5.

7. The packaging bottle raw material composition according to claim 6, wherein, Based on the total weight of the raw material composition for the packaging bottle, the content of the functional masterbatch is 0.5-15.0%, and the content of polyethylene terephthalate is 85.0-99.5%.

8. The packaging bottle raw material composition according to claim 7, wherein, Based on the total weight of the raw material composition for the packaging bottle, the content of the functional masterbatch is 3.0-6.5%, and the content of polyethylene terephthalate is 93.5-97.0%.

9. A packaging bottle made from the packaging bottle raw material composition according to any one of claims 6-8.

10. The packaging bottle according to claim 9, wherein, The bottle body is made of the packaging bottle raw material composition according to any one of claims 6-8.

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