Polypropylene nonwoven fabric with flavor masterbatch, and preparation method and application thereof

Abstract

The application discloses a kind of polypropylene non-woven fabric and its preparation method and application of fragrance masterbatch, polypropylene non-woven fabric is made of the following weight percentage components: 30~40% polypropylene resin, 10~20% polar polyolefin resin, 15~25% fragrance aid, 5~15% adsorbent and 10~20% filler;Polypropylene resin uses the average particle size of 50~200 purpose metallocene modified polypropylene resin powder, it is made by metallocene modified polypropylene resin granules under freezing condition by grinding powder processing.The polypropylene non-woven fabric of the application of fragrance masterbatch uses metallocene modified polypropylene resin powder as carrier resin, the melting point of this polypropylene resin is ≤120℃, so that lower extrusion processing temperature can be realized, guarantee that extrusion processing temperature is highest not more than 140℃, so as to significantly reduce the volatilization loss of fragrance aid, guarantee that it has higher concentration.

Description

Technical Field

[0001] This invention belongs to the field of polypropylene nonwoven fabric technology, specifically relating to a fragrance masterbatch for polypropylene nonwoven fabric, its preparation method, and its application. Background Technology

[0002] In recent years, face masks have become an essential item for many people when going out. Whether it is to prevent the spread of respiratory viruses or to protect against air pollution such as smog, face masks are very important items. Most of the disposable face masks currently available are made of polypropylene non-woven fabric.

[0003] Currently, fragrance masterbatches using polypropylene resin as the carrier resin have many shortcomings, the biggest being poor fragrance persistence. This makes them difficult to apply to the preparation of polypropylene fragrance nonwoven fabrics. The root causes of this deficiency are mainly due to the following two aspects: (1) The amount of fragrance additives added in the fragrance masterbatch is low, usually not exceeding 10% [see reference 1], resulting in a low concentration of fragrance additives.

[0004] This is because the flavoring additive is in liquid form. If the amount added is too high, it will not only cause the material to clump severely, affecting normal feeding and making it difficult to process, but it will also easily cause the material to become overly lubricated, which will greatly weaken the mixing effect of the screw, making it difficult for the mixed material to form a homogeneous phase and unable to achieve normal strand pulling and pelletizing.

[0005] (2) Conventional fragrance additives usually have poor temperature resistance, while the extrusion processing temperature of conventional polypropylene resin is usually above 160°C [see Reference 1 Example 2]. Higher extrusion processing temperature will cause the fragrance additives to evaporate and be lost, thereby further reducing the concentration of fragrance additives in the fragrance masterbatch; in addition, higher extrusion processing temperature will also affect the internal structure of the fragrance additives, resulting in changes in odor.

[0006] Reference 2 discloses a method for preparing a scented plastic masterbatch, including the formulation of fragrance, impregnation with activated carbon, co-extrusion, and cutting and granulation. The shortcomings of this reference are: the preparation process is complex, especially the need to formulate special high-temperature resistant fragrance, which leads to high production costs, and the content of fragrance additives in this reference is not clear.

[0007] Reference 1: Chinese patent document CN102558651A, published on July 11, 2012.

[0008] Reference 2: Chinese patent document CN107151382A, published on September 12, 2017. Summary of the Invention

[0009] The purpose of this invention is to solve the above-mentioned problems and provide a polypropylene nonwoven fabric fragrance masterbatch with not only high fragrance additive concentration and long fragrance persistence, but also good processing stability and low production cost, as well as its preparation method and application.

[0010] The technical solution to achieve the purpose of this invention is: a fragrance masterbatch for polypropylene nonwoven fabric, which is made of the following components by weight percentage: 30-40% polypropylene resin, 10-20% polar polyolefin resin, 15-25% fragrance additive, 5-15% adsorbent and 10-20% filler.

[0011] The polypropylene resin used is metallocene-modified polypropylene resin powder with an average particle size of 50-200 mesh, which is obtained by grinding metallocene-modified polypropylene resin granules under frozen conditions.

[0012] The metallocene-modified polypropylene resin powder has a melt index of 20-50 g / 10 min and a melting point of ≤120℃.

[0013] The polar polyolefin resin is one or two of the following: ethylene-vinyl acetate copolymer (EVA resin), ethylene-butyl acrylate copolymer (EBA resin), ethylene-acrylic acid copolymer (EAA resin), ethylene-methyl acrylate copolymer (EMA resin), ethylene-ethyl acrylate copolymer (EEA resin), and ethylene-methyl methacrylate copolymer (EMMA resin); preferably, it is one of EVA resin and EBA resin, EAA resin, EMA resin, EEA resin, and EMMA resin.

[0014] The EVA resin has a melt index of 20-50 g / 10 min and a VA content of 25-50%.

[0015] The fragrance additive is one or two of the following: peppermint essential oil, rose essential oil, jasmine essential oil, vanilla essential oil, lemon essential oil, lavender essential oil, and marine essential oil, with peppermint essential oil being preferred.

[0016] The adsorbent is one or two of silica, diatomaceous earth, zeolite, talc, and wollastonite, preferably silica or diatomaceous earth.

[0017] The silica is preferably ultrafine silica with a pore volume > 0.8 L / g.

[0018] The filler is calcium carbonate.

[0019] The preparation method of the above-mentioned fragrance masterbatch for polypropylene nonwoven fabric includes the following steps: ① First, the metallocene-modified polypropylene resin granules are ground under freezing conditions to obtain metallocene-modified polypropylene resin powder with an average particle size of 50-200 mesh.

[0020] ② Add the polar polyolefin resin, filler, adsorbent, some fragrance additives and the metallocene modified polypropylene resin powder obtained in step ① to a high-speed mixer according to the weight percentage, and stir and mix at low speed for 1 to 3 minutes; the partial fragrance additives account for 50 to 70% of the total amount of fragrance additives.

[0021] ③ The mixed material from step ② is added to a twin-screw extruder for compounding and extrusion. At the same time, the remaining fragrance additives are injected into the twin-screw extruder through a plunger metering pump for compounding and extrusion. Then, the mixture is stretched, water-cooled, air-cooled, and pelletized to obtain the fragrance masterbatch for polypropylene nonwoven fabric.

[0022] The mixing and extrusion temperature of the twin-screw extruder is 120-140℃, with a maximum temperature not exceeding 140℃.

[0023] The temperatures of each zone of the twin-screw extruder are 100℃, 120℃, 130℃, 140℃, 130℃, 130℃, 130℃, 120℃, 120℃, and 120℃.

[0024] The above-mentioned fragrance masterbatch for polypropylene nonwoven fabric is used in the preparation of fragranced polypropylene nonwoven fabric.

[0025] The aforementioned polypropylene scented nonwoven fabric is preferably used for polypropylene scented face masks.

[0026] The positive effects of this invention are: (1) The polypropylene nonwoven fabric fragrance masterbatch of the present invention uses metallocene modified polypropylene resin powder as carrier resin. The melting point of the polypropylene resin is ≤120℃, which can achieve a lower extrusion processing temperature and ensure that the extrusion processing temperature does not exceed 140℃, thereby significantly reducing the volatilization loss of fragrance additives and ensuring that they have a high concentration.

[0027] (2) The preparation method of the polypropylene nonwoven fabric fragrance masterbatch of the present invention is to add a portion of the fragrance additive (about 60%) from the main feed port, and the remaining fragrance additive (about 40%) is injected from the melt section of the twin-screw extruder using a plunger metering pump. This will not affect the normal feeding or weaken the mixing effect of the screw, and has good processing stability. This allows for the addition of a high content of fragrance additive, further ensuring the concentration of fragrance additive and achieving a longer fragrance persistence. Detailed Implementation

[0028] (Example 1) The fragrance masterbatch for polypropylene nonwoven fabric in this embodiment is made from the following components by weight percentage: 36% metallocene-modified polypropylene resin powder, 8% EVA resin, 9% EBA resin, 20% peppermint essential oil fragrance additive, 12% silica and 15% calcium carbonate.

[0029] The aforementioned metallocene-modified polypropylene resin powder is obtained by grinding metallocene-modified polypropylene resin granules under freezing conditions. Its average particle size is 100-150 mesh, melt index is 35 g / 10 min, and melting point is ≤120℃.

[0030] The melt flow index of the above-mentioned EVA resin is 35 g / 10 min, and the VA content is 35%.

[0031] The silica used above is ultrafine silica with a pore volume of 1.5 L / g.

[0032] The preparation method of the fragrance masterbatch for polypropylene nonwoven fabric in this embodiment is as follows: ① First, the metallocene-modified polypropylene resin granules are ground under freezing conditions to obtain metallocene-modified polypropylene resin powder with an average particle size of 100-150 mesh.

[0033] ② Add EVA resin, EBA resin, calcium carbonate, ultrafine silica, a portion of the fragrance additive (60% in this example), and the metallocene modified polypropylene resin powder obtained in step ① to a high-speed mixer according to the weight percentage, and stir at low speed for 1.5 minutes.

[0034] ③ The mixed material from step ② is added to the twin-screw extruder for compounding and extrusion (from the main feed port of the twin-screw extruder). At the same time, the remaining 40% of the fragrance additive is injected into the twin-screw extruder for compounding and extrusion through a plunger metering pump (from the melt section of the twin-screw extruder). Then, after stretching, water cooling, air cooling, and pelletizing, the fragrance masterbatch for polypropylene nonwoven fabric is obtained.

[0035] The mixing and extrusion temperature of the twin-screw extruder is 120-140℃, with the maximum temperature not exceeding 140℃.

[0036] The temperatures of each zone of the twin-screw extruder are as follows: Zone 1 100℃, Zone 2 120℃, Zone 3 130℃, Zone 4 140℃, Zone 5 130℃, Zone 6 130℃, Zone 7 130℃, Zone 8 120℃, Zone 9 120℃, and Zone 10 120℃.

[0037] The masterbatch is extruded into strips and cooled with water; the water temperature of the strips should be controlled below 40°C.

[0038] (Examples 2 to 4) The preparation methods of the polypropylene nonwoven fabric fragrance masterbatch in each embodiment are the same as those in Example 1, except that each component and its weight percentage are shown in Table 1.

[0039] Table 1 Example 1 Example 2 Example 3 Example 4 Metallocene modified polypropylene resin powder 36% 39% 32% 39% EVA resin 8% 8% 8% 8% EBA resin 9% / / / EAA resin / 7% / / EMA resin / / 11% / EEA resin / / / 7% Fragrance additives 20% peppermint flavoring 10% peppermint essence + 9% rose essence 10% peppermint essence + 12% jasmine essence 18% peppermint flavoring silicon dioxide 12% / 12% / diatomite / 15% / 15% Calcium carbonate 15% 12% 15% 13%

[0040] (Comparative Example 1) The only difference between the composition of the polypropylene nonwoven fabric fragrance masterbatch in this comparative example and that in Example 1 is that the polypropylene resin is polypropylene granules specifically for polypropylene nonwoven fabric (i.e., conventional polypropylene resin).

[0041] The only difference between the preparation method of the polypropylene nonwoven fabric fragrance masterbatch in this comparative example and Example 1 is that the extrusion processing temperature is 160-210℃.

[0042] The temperatures of each zone of the twin-screw extruder are as follows: Zone 1 160℃, Zone 2 170℃, Zone 3 190℃, Zone 4 210℃, Zone 5 200℃, Zone 6 190℃, Zone 7 180℃, Zone 8 170℃, Zone 9 160℃, and Zone 10 160℃.

[0043] (Comparative Example 2) The only difference between this comparative example and Example 1 is that the polypropylene resin is polypropylene granules specifically for polypropylene nonwoven fabric (i.e., conventional polypropylene resin).

[0044] That is, the extrusion processing temperature is the same as in Example 1.

[0045] Result: The polypropylene resin could not be plasticized properly, which prevented the extrusion process from proceeding normally.

[0046] (Comparative Example 3) The only difference between this comparative example and Example 1 is the method of adding the fragrance additive in steps ② and ③.

[0047] ② Add EVA resin, EBA resin, calcium carbonate, ultrafine silica, all fragrance additives, and the metallocene modified polypropylene resin powder obtained in step ① to a high-speed mixer according to the weight percentage, and mix at low speed for 1.5 minutes.

[0048] ③ Add the mixed material from step ② (from the main feed port of the twin-screw extruder) into the twin-screw extruder for compounding and extrusion.

[0049] Result: The material severely clumped and bridged, causing the extrusion process to be unable to proceed normally.

[0050] (Application Example 1) This application example demonstrates the preparation of scented polypropylene nonwoven fabric using the scented masterbatch for polypropylene nonwoven fabric obtained in Example 1. The specific method is as follows: The polypropylene nonwoven fabric fragrance masterbatch prepared in Example 1 (4%) was mixed with 96% polypropylene granules for nonwoven fabric, extruded, spun, and hot-rolled to obtain polypropylene fragrance nonwoven fabric.

[0051] (Application Examples 2 to 4) The polypropylene nonwoven fabric fragrance masterbatches prepared in Examples 2 to 4 were used to prepare polypropylene fragrance nonwoven fabrics according to the method of Application Example 1.

[0052] (Comparative application examples) The polypropylene nonwoven fabric fragrance masterbatch obtained in Comparative Example 1 was used to prepare polypropylene fragrance nonwoven fabric according to the method of Application Example 1.

[0053] (Test example) The odor persistence of the polypropylene scented nonwoven fabrics prepared in Application Examples 1 to 4 and the comparative application example was tested. The test method is as follows: Under normal natural placement conditions, the odor persistence was verified by repeating the odor test every 20 days. A total of 5 odor test tests were conducted within 80 days. Each test was conducted by 10 people and the average value was calculated. The results are shown in Table 3.

[0054] The explanation of the odor assessment grading is shown in Table 2.

[0055] Table 2 Fraction Odor assessment 1 Unrecognizable 2 Identifiable, without interfering factors 3 Clear and discernible, without any interfering factors 4 There are interfering factors 5 There are serious interfering factors 6 Unbearable

[0056] Table 3 Odor assessment on day 1 Odor assessment on day 20 Odor assessment on day 40 Odor assessment on day 60 Odor assessment on day 80 Application Example 1 3.6 3.2 2.9 2.7 2.4 Application Example 2 3.5 3.3 3.0 2.7 2.5 Application Example 3 3.8 3.6 3.3 3.0 2.8 Application Example 4 3.5 3.3 3.0 2.8 2.6 Comparative Application Examples 3.2 2.6 1.9 1.4 1.1

Claims

1. A fragrance masterbatch for polypropylene nonwoven fabrics, characterized in that... It is made from the following components by weight percentage: 30-40% polypropylene resin, 10-20% polar polyolefin resin, 15-25% fragrance additives, 5-15% adsorbents, and 10-20% fillers; the polypropylene resin used is metallocene-modified polypropylene resin powder with an average particle size of 50-200 mesh, which is obtained by grinding metallocene-modified polypropylene resin granules under frozen conditions; the melt index of the metallocene-modified polypropylene resin powder is 20-50 g / 10 min, and the melting point is ≤120℃. The flavoring additives are added in stages: a portion is added from the main feed port of the twin-screw extruder, and the remaining flavoring additives are injected from the rear zone of the melt section of the twin-screw extruder using a plunger metering pump; the portion of flavoring additives constitutes 50-70% of the total flavoring additives. The mixing and extrusion temperature of the twin-screw extruder is 120–140°C.

2. The fragrance masterbatch for polypropylene nonwoven fabric according to claim 1, characterized in that: The polar polyolefin resin is one or two of the following: ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl methacrylate copolymer.

3. The fragrance masterbatch for polypropylene nonwoven fabric according to claim 2, characterized in that: The polar polyolefin resin is one of EVA resin, EBA resin, EAA resin, EMA resin, EEA resin, and EMMA resin; the EVA resin has a melt index of 20-50 g / 10 min and a VA content of 25-50%.

4. The fragrance masterbatch for polypropylene nonwoven fabric according to claim 1, characterized in that: The fragrance additive is one or two of the following: peppermint essential oil, rose essential oil, jasmine essential oil, vanilla essential oil, lemon essential oil, lavender essential oil, and marine essential oil.

5. The fragrance masterbatch for polypropylene nonwoven fabric according to claim 1, characterized in that: The adsorbent is one or two of silica, diatomaceous earth, zeolite, talc, and wollastonite; the filler is calcium carbonate.

6. A method for preparing a fragrance masterbatch for polypropylene nonwoven fabric according to any one of claims 1 to 5, comprising the following steps: ① First, the metallocene-modified polypropylene resin granules are ground under freezing conditions to obtain metallocene-modified polypropylene resin powder with an average particle size of 50-200 mesh. ② Add the polar polyolefin resin, filler, adsorbent, some fragrance additives, and the metallocene-modified polypropylene resin powder obtained in step ① to a high-speed mixer according to the weight percentage, and mix at low speed for 1-3 minutes; the aforementioned fragrance additives constitute 50-70% of the total amount of fragrance additives. ③ Add the mixed material from step ② to a twin-screw extruder for compounding and extrusion. At the same time, inject the remaining fragrance additive into the twin-screw extruder through a plunger metering pump for compounding and extrusion. Then, after stretching, water cooling, air cooling, and pelletizing, obtain the fragrance masterbatch for polypropylene nonwoven fabric. The mixing and extrusion temperature of the twin-screw extruder is 120–140°C.

7. The method for preparing the fragrance masterbatch for polypropylene nonwoven fabric according to claim 6, characterized in that: The temperatures of each zone of the twin-screw extruder are 100℃, 120℃, 130℃, 140℃, 130℃, 130℃, 130℃, 120℃, 120℃, and 120℃.

8. The use of the polypropylene nonwoven fabric fragrance masterbatch according to any one of claims 1 to 5 in the preparation of polypropylene fragrance nonwoven fabric.

9. The application according to claim 8, characterized in that: The polypropylene scented nonwoven fabric is used in polypropylene scented face masks.