Polypropylene composition and use thereof

Abstract

This invention discloses a polypropylene composition and its applications, belonging to the field of polymer composition technology. The invention provides a polypropylene composition comprising polypropylene, a hindered phenolic antioxidant, a phosphite antioxidant, guaiacol, gallic acid, a dispersant, a light stabilizer, and a metal ion passivator. By incorporating the above components, the polypropylene polymer provided by this invention can synergistically enhance the anti-phenolic yellowing effect of the hindered phenol-phosphite composite antioxidant, resulting in a polypropylene composition that possesses both good anti-phenolic yellowing effect and good dyeing adsorption rate.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a polypropylene composition and its applications. Background Technology

[0002] Polypropylene fiber textiles are prone to yellowing due to phenolic yellowing caused by factors such as contact with the human body, long-term exposure to sunlight and air, and the addition of metal additives to the materials. This makes the fabrics unsightly, thus requiring anti-phenolic yellowing treatment. This is especially true for polypropylene fibers made from recycled materials. Recycled materials are more susceptible to photo-oxidative degradation during long-term use, or to the introduction of impurities through contact with the human body, environment, and other objects. The content of free radicals and metal ions in recycled materials is much higher than that of virgin polypropylene, making recycled polypropylene fibers more prone to yellowing than virgin polypropylene fibers. Therefore, anti-phenolic yellowing treatment of recycled polypropylene fibers is more challenging.

[0003] Currently, the industry's main focus is on the anti-phenolic yellowing treatment of virgin polypropylene fibers, while related technologies for recycled polypropylene fibers are still relatively rare. Summary of the Invention

[0004] To address the shortcomings of existing anti-phenolic yellowing treatment technologies for recycled polypropylene fibers, this invention provides a polypropylene composition. The polypropylene composition provided by this invention exhibits excellent anti-phenolic yellowing effects.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned polypropylene composition.

[0006] Another object of the present invention is to provide the application of the above-described polypropylene composition.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A polypropylene composition, by weight, comprises the following components: 100 parts homopolymer polypropylene; 0.1-0.2 parts of hindered phenolic antioxidant; 0.2-0.3 parts of phosphite antioxidants; Guaiacin 0.1~0.2 parts; Gallic acid 0.2-0.3 parts; Dispersant 0.1~0.2 parts; Light stabilizer 0.1~0.2 parts; 0.1 to 0.2 parts of metal ion passivating agent.

[0008] This invention discovers that a compound natural phenol composed of guaiacol and gallic acid can enhance the anti-phenolic yellowing effect of a compound antioxidant system composed of hindered phenolic antioxidants and phosphite antioxidants, and also has a stabilizing effect on the above compound antioxidant system, thus giving it a good anti-phenolic yellowing effect.

[0009] This invention does not limit the source or age of polypropylene; the anti-phenolic yellow system of this invention can be applied to all such polypropylene.

[0010] Specifically, the polypropylene may be virgin polypropylene and / or recycled polypropylene.

[0011] In particular, the anti-phenolic yellowing system of the present invention is especially suitable for homopolymer polypropylene with an isotacticity > 92%. The anti-phenolic yellowing component of the present invention has better compatibility with homopolymer polypropylene with an isotacticity > 92%, thereby resulting in a better anti-phenolic yellowing effect. Therefore, the anti-phenolic yellowing system of the present invention is particularly suitable for preparing polypropylene chips or polypropylene fibers. Furthermore, the anti-phenolic yellowing system of the present invention can also improve the dyeing effect of polypropylene fibers.

[0012] The anti-phenolic yellowing system of the present invention also has a good anti-phenolic yellowing effect on recycled polypropylene that has been aged, has many free radicals, many metal impurities, and is prone to photo-oxidative aging.

[0013] Specifically, the melt flow rate of the polypropylene is 10~40 g / 10 min.

[0014] Specifically, the hindered phenolic antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexanediamine, and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Preferably, the hindered phenolic antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0015] Specifically, the phosphite antioxidant is selected from at least one of tris[2,4-di-tert-butylphenyl] phosphite and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, preferably, the phosphite antioxidant is tris[2,4-di-tert-butylphenyl] phosphite.

[0016] Specifically, the dispersant is selected from polyethylene wax and silane coupling agents. The above dispersant can improve the compatibility between natural phenols and polypropylene, prevent the aggregation or precipitation of natural phenols, and improve the fiber dyeing adsorption rate and anti-phenol yellowing effect.

[0017] Preferably, the dispersant is polyethylene wax. Polyethylene wax not only has excellent compatibility with polypropylene, but also unexpectedly enables more effective dispersion of guaiacol and gallic acid within the polypropylene.

[0018] Preferably, the light stabilizer is selected from at least one of hindered amine light stabilizers, benzotriazole light stabilizers, and benzophenone light stabilizers. The light stabilizer can effectively inhibit the photodegradation of guaiacol and gallic acid, further improving the anti-phenol yellowing effect.

[0019] More preferably, the light stabilizer is a hindered amine light stabilizer. Hindered amine light stabilizers have a better effect on inhibiting the photodegradation of natural phenols.

[0020] Preferably, the metal ion passivating agent is selected from at least one of calcium stearate, 1,2-bis(3,5-di-tert-butyl-4-hydroxycinnamoyl)hydrazine, and N,N'-disalicylaldehyde ethylenediamine.

[0021] More preferably, the metal ion passivating agent is calcium stearate. Calcium stearate can not only chelate residual metal ions in recycled polypropylene, but also synergistically improve the compatibility of natural phenols with polypropylene with dispersants, further improving the fiber dyeing adsorption rate and anti-phenol yellowing effect.

[0022] This invention also protects a method for preparing the above-mentioned polypropylene composition, comprising the following steps: Hindered phenolic antioxidants, phosphite antioxidants, guaiacol, gallic acid, dispersants, light stabilizers, and metal ion passivators are added to a high-speed mixer to obtain a premix. Polypropylene and premixed materials are fed together into a twin-screw extruder, melted, extruded, and pelletized to obtain the polypropylene composition.

[0023] The present invention also protects a polypropylene chip comprising the above-described polypropylene composition.

[0024] The present invention also protects a polypropylene fiber obtained by spinning the above-mentioned polypropylene composition or polypropylene chips.

[0025] The present invention also protects a textile fabric woven from the aforementioned polypropylene fibers.

[0026] Compared with the prior art, the present invention has the following beneficial effects: The polypropylene composition provided by this invention, by adding guaiacol, gallic acid, dispersant, light stabilizer and metal ion passivator, can, on the one hand, synergistically improve the anti-phenolic yellowing effect of hindered phenol-phosphite compound antioxidant, and on the other hand, improve the dyeing adsorption rate of the polypropylene composition. Detailed Implementation

[0027] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0028] The reagents used in the various embodiments and comparative examples of this invention are described below: New polypropylene 1: Grade PPH-Z30S, manufacturer: Sinopec Beihai Refining & Chemical Co., Ltd., melt flow rate: 26g / 10min, phenol yellow grade: 3.5; New polypropylene 2: Grade PPH-T03 (T30S), manufactured by Zhongtian Hechuang Energy Co., Ltd. Chemical Branch, melt flow rate 3g / 10min, phenol yellow grade: 3.5; Simulated recycled polypropylene 1: New polypropylene 1 was soaked in edible oil and then subjected to photoaging for 72 hours, followed by washing and granulation; melt flow rate 40 g / 10 min, phenol yellow grade: 1. Simulated recycled polypropylene 2: New polypropylene 2 was aged by soaking in seawater under light for 72 hours, followed by washing and granulation; melt flow rate 4.5 g / 10 min, phenol yellow grade: 1.5; Recycled polypropylene 1: sourced from food container particles, melt flow rate 60g / 10min, phenol yellow grade: 1.5; Recycled polypropylene 2: sourced from marine cable particles, melt flow rate 4.2 g / 10 min, phenol yellow grade: 1.5.

[0029] Hindered phenolic antioxidant 1: Antioxidant 1010, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]; Hindered phenolic antioxidant 2: Antioxidant 1098, N,N'-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine; Hindered phenolic antioxidant 3: Antioxidant 1076, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester; Phosphite antioxidant 1: Antioxidant 168, tris[2,4-di-tert-butylphenyl]phosphite; Antioxidant 2: Antioxidant 626, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite.

[0030] Hydroxylamine antioxidants: Revonox 420, bis(hydrogenated tallow alkyl)amine oxide; Thioether antioxidant: Pentaerythritol tetra(3-lauryl thiopropionate).

[0031] Guaiacin: CAS No. 90-05-1, commercially available; Gallic acid: CAS No. 149-91-7, commercially available; Catechol: CAS No. 120-80-9, commercially available; 3,4-Dihydroxybenzoic acid: CAS No. 99-50-3, commercially available.

[0032] Dispersant 1: Polyethylene wax; Dispersant 2: Silane coupling agent.

[0033] Light stabilizer 1: M535, CYASORB CYNERGY SOLUTIONS® M535; Light stabilizer 2: UV-531, 2-hydroxy-4-n-octyloxybenzophenone.

[0034] Metal ion passivating agent 1: calcium stearate; Metal ion passivating agent 2: IRGANOX MD 1024, 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine.

[0035] The polypropylene compositions of the embodiments and comparative examples of the present invention were prepared by the following process: (1) Premixing of additives Weigh out each auxiliary agent according to the formula; Add the above-mentioned additives into a high-speed mixer and stir at 1000-1200 r / min for 10-15 minutes to obtain a uniform "anti-phenol yellow additive premix".

[0036] (2) Preparation of slices by blending and extrusion The polypropylene and additive premix are fed into a twin-screw extruder, and the extrusion temperature is set as follows: feeding section 160-170℃, melting section 190-200℃, homogenization section 210-220℃, and die head section 205-215℃. The screw speed is controlled at 300-350 r / min. After impurities are filtered through a 200-mesh filter, the product is extruded into strips through a die. The extruded strip is placed in a water cooling tank (water temperature 20-30℃) to cool and set, and then cut into polypropylene chips with a length of 3-5mm and a diameter of 2-3mm by a pelletizer.

[0037] (3) Spinning to prepare polypropylene fibers Polypropylene chips are placed in a vacuum dryer and dried at 85-95℃ for 8-10 hours, controlling the moisture content to ≤0.05%. Melt spinning is then used, with the following spinning temperatures set: screw zone 1 180-190℃, zone 2 200-210℃, zone 3 220-230℃, spinneret temperature 215-225℃, spinneret orifice diameter 0.25mm, spinning speed 800-1000m / min. After drawing (draw ratio 3.5-4.0) and setting (120-130℃), anti-phenolic yellow polypropylene fibers with a linear density of 1.5-2.0 dtex are obtained.

[0038] The performance testing methods and standards for the polypropylene compositions of the various embodiments and comparative examples of the present invention are as follows: Phenolic yellowing grade: Referring to GB / T29778-2013 "Evaluation of potential phenolic yellowing in color fastness testing of textiles", the phenolic yellowing grade of polypropylene fabrics was tested. The sample and control fabrics were each cut to 100mm × 30mm; the test paper was folded in half to 50mm × 75mm, and the sample / control fabric was sandwiched between the test paper. The sandwiched test paper was placed between glass plates (≤5 samples + 1 control sample), tightly sealed with three layers of BHTPE-free film, and subjected to a pressure of 5.0±0.1kg. It was then subjected to constant temperature treatment: (50±3)℃ for 16h±15min; after cooling, the samples were graded one by one using a staining gray card, and the phenolic yellowing grade was recorded. The grading was completed within 30 minutes. The specific grading and phenolic yellowing results are shown below: Grade 5: No yellowing, best resistance to phenol yellowing, no visible yellowing; Grade 4-4.5, slight yellowing, basically acceptable, yellowing is extremely inconspicuous; Grade 3-3.5, moderate yellowing, borderline acceptable, with identifiable yellowing; Grade 2-2.5, significant yellowing, unqualified, obvious yellowing; Grade 1-1.5, severe yellowing, seriously unqualified, intense yellowing.

[0039] Dyeing adsorption rate: Referring to GB / T23976.2-2009 "Determination of Dyeing Performance of Dyes", the dye solution was prepared according to the set concentration. The dye selected was sodium 2-(4-sulfonyl-1-naphthazo)-1-naphthol-4-sulfonate (Acid Red G). The fabric was quantitatively immersed in the solution until adsorption reached equilibrium. The concentration of the residual dyeing liquor was determined by spectrophotometry, and the dyeing adsorption rate was calculated (formula: adsorption rate = (initial concentration - residual concentration) / initial concentration × 100%).

[0040] Melt flow rate: The melt flow rate of polypropylene granules was tested according to ISO 1133-1 standard at a temperature of 230℃ and a pressure of 2.16 kg.

[0041] Examples and Comparative Examples The formulations of the various embodiments and comparative examples of the present invention are shown in the table below.

[0042] Table 1

[0043] Continued from Table 1

[0044] Continued from Table 1

[0045] Continued from Table 1

[0046] As can be seen from Table 1, the phenol yellow grade of each embodiment is ≥3 and the dyeing adsorption rate is >75%, indicating that the anti-phenol yellow system of the present invention has a good anti-phenol yellow effect, and the polypropylene fiber prepared by the polypropylene composition of the present invention has a good dyeing adsorption rate.

[0047] Comparative Example 1 used other types of antioxidants, and its anti-phenol yellowing effect was significantly reduced, and the staining adsorption rate was lower than that of Example 3. This indicates that guaiacol and gallic acid did not significantly improve the anti-phenol yellowing effect of other types of antioxidants, and the effect of other types of antioxidants on improving the staining adsorption rate was not as good as that of the combined antioxidants of hindered phenols and phosphites.

[0048] Comparative Example 2 used 3,4-dihydroxybenzoic acid instead of gallic acid, and Comparative Example 3 used catechol instead of guaiacol. The anti-phenol yellowing effect of both was significantly reduced, and the staining adsorption rate was lower than that of Example 3. This indicates that other compound natural phenols cannot effectively improve the anti-phenol yellowing effect of hindered phenols and phosphites compound antioxidants. Moreover, the effect of other compound natural phenols on improving the staining adsorption rate is not as good as that of the compound natural phenols of guaiacol and gallic acid.

[0049] Comparative Example 4 without gallic acid and Comparative Example 5 without guaiacol showed significantly reduced anti-phenol yellowing effects and no significant increase in dye adsorption rate. This indicates that neither gallic acid nor guaiacol alone can effectively improve the anti-phenol yellowing effect of the combined antioxidants of hindered phenols and phosphites, and that neither gallic acid nor guaiacol alone has a limited effect on improving dye adsorption rate.

[0050] Comparative Example 6, without any added natural phenols, showed a significantly worse anti-phenol yellowing effect than the examples, and its staining adsorption rate was also inferior to the examples. This indicates that without the addition of guaiacol and gallic acid, the anti-phenol yellowing effect of the hindered phenol and phosphite compound antioxidant was very poor, and the staining adsorption rate was also insufficient.

[0051] Comparative Example 7, without the addition of a dispersant, exhibited inferior anti-phenolic yellowing effects and staining adsorption rates compared to Example 3. This is because the dispersant has good compatibility with guaiacol and gallic acid, allowing it to be uniformly dispersed into the polymer matrix as a carrier. The absence of a dispersant leads to the aggregation of these natural components, reducing the anti-phenolic yellowing effect.

[0052] Comparative Example 8, without the addition of a light stabilizer, showed inferior anti-phenol yellowing effects compared to Example 3.

[0053] Comparative Example 9, without the addition of a metal ion passivating agent, showed inferior anti-phenol yellow effect and staining adsorption rate compared to Example 3, indicating that the addition of a metal ion passivating agent to the system of the present invention can further improve the anti-phenol yellow effect and staining adsorption rate.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composition, characterized in that, By weight, it includes the following components: 100 parts homopolymer polypropylene; 0.1-0.2 parts of hindered phenolic antioxidant; 0.2-0.3 parts of phosphite antioxidants; Guaiacin 0.1~0.2 parts; Gallic acid 0.2-0.3 parts; Dispersant 0.1~0.2 parts; Light stabilizer 0.1~0.2 parts; 0.1 to 0.2 parts of metal ion passivating agent.

2. The polypropylene composition according to claim 1, characterized in that, The isotacticity of the polypropylene is >92%, and the melt flow rate of the polypropylene is 10~40 g / 10 min.

3. The polypropylene composition according to claim 1, characterized in that, The hindered phenolic antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

4. The polypropylene composition according to claim 1, characterized in that, The phosphite antioxidant is selected from at least one of tris[2,4-di-tert-butylphenyl] phosphite and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite.

5. The polypropylene composition according to claim 1, characterized in that, The dispersant is selected from polyethylene wax and silane coupling agent.

6. The polypropylene composition according to claim 1, characterized in that, The light stabilizer is selected from at least one of hindered amine light stabilizers, benzotriazole light stabilizers, and benzophenone light stabilizers.

7. The polypropylene composition according to claim 1, characterized in that, The metal ion passivating agent is selected from at least one of calcium stearate, 1,2-bis(3,5-di-tert-butyl-4-hydroxycinnamoyl)hydrazine, and N,N'-disalicylaldehyde ethylenediamine.

8. A polypropylene chip, characterized in that, Includes the polypropylene composition according to any one of claims 1 to 7.

9. A polypropylene fiber, characterized in that, Obtained by spinning from the polypropylene composition of any one of claims 1 to 7 or the polypropylene chips of claim 8.

10. A textile product, characterized in that, It is woven from the polypropylene fiber as described in claim 9.

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