Radiation-resistant PP composition, preparation method thereof and non-woven fabric

Abstract

The invention belongs to the technical field of polypropylene materials, and discloses an irradiation-resistant PP composition, a preparation method thereof and a non-woven fabric. The PP composition comprises polypropylene resin, a polyolefin elastomer and modified polypropylene master batch, the polyolefin elastomer comprises at least one of a random ethylene-propylene copolymer and a vinyl elastomer; the modified polypropylene master batch is prepared from the following raw materials: polypropylene, a hindered amine light stabilizer, an antioxidant, an initiator and an interface compatilizer. Due to the fact that the modified polypropylene master batch is obtained through modification in a special mode and is matched with the polyolefin elastomer and the polypropylene resin, the PP composition has good irradiation resistance, and good mechanical performance and yellowing resistance are still kept after irradiation.

Description

Technical Field

[0001] The invention belongs to the technical field of polypropylene materials, and particularly relates to a radiation-resistant PP composition, a preparation method thereof and a non-woven fabric. Background Art

[0002] Polypropylene (PP) is one of the most widely used polymer materials at home and abroad. It is widely used in many fields because of its good quality, low price, tasteless and non-toxic, wide source, excellent mechanical strength and good chemical stability. For example, in the medical field, non-woven fabrics made of PP can be further made into products such as bed sheets, surgical packs, surgical gowns, and sterilization wraps. These medical supplies need to be disinfected and sterilized before use.

[0003] Traditional sterilization methods generally use ethylene oxide for disinfection, but ethylene oxide not only pollutes the environment but also leaves residues after sterilization, which is harmful to the health of users. Radiation sterilization has become the main sterilization method for medical supplies due to its strong penetration ability, simple operation, rapid sterilization and no precipitation after sterilization. However, ordinary medical PP non-woven fabrics have poor irradiation stability. After irradiation, the mechanical properties of the product deteriorate, and the appearance is prone to yellowing, so that it loses its performance.

[0004] The existing technology discloses the use of thermoplastic elastomer to toughen polypropylene, acetone thiosemicarbazone to eliminate free radicals generated after polypropylene irradiation, phenolic antioxidants as the main antioxidants, so that the transfer and growth of free radical chains in the irradiation oxidation process of polypropylene materials are terminated; thioester antioxidants and phosphite antioxidants are used as auxiliary antioxidants to prevent or slow down the generation of free radicals in the oxidative aging process. The non-woven fabric obtained by this method has very excellent radiation resistance, but the phenolic antioxidants are easy to aggravate the color change of the polypropylene non-woven fabric during the irradiation process, resulting in significantly poor yellowing resistance. The existing technology also discloses the use of polyolefin elastomers to toughen polypropylene, and the use of light stabilizers, antioxidants and compatibilizers to blend and modify polypropylene to give the raw materials radiation resistance. The polyolefin elastomer used in this method is relatively expensive, the stabilizer is easy to disperse unevenly, and the low molecular weight stabilizer is easy to precipitate to the surface after irradiation, and the irradiation effect is not stable enough.

[0005] Therefore, there is an urgent need to provide a new PP-based material that has good radiation resistance, good mechanical properties, and is not prone to yellowing. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a radiation-resistant PP composition and a preparation method thereof and a non-woven fabric. The PP composition of the present invention has good radiation resistance and still maintains good mechanical properties and yellowing resistance after irradiation. The PP composition of the present invention is applied to the non-woven fabric, so that the non-woven fabric has good radiation resistance, for example, after irradiation, the non-woven fabric is not easy to yellow and has good mechanical properties.

[0007] A first aspect of the present invention provides a radiation-resistant PP composition.

[0008] Specifically, a radiation-resistant PP composition includes a polypropylene resin, a polyolefin elastomer, and a modified polypropylene masterbatch;

[0009] The polyolefin elastomer includes at least one of a random ethylene-propylene copolymer and a vinyl elastomer.

[0010] The raw materials for preparing the modified polypropylene masterbatch include polypropylene, hindered amine light stabilizer, antioxidant, initiator and interface compatibility agent.

[0011] Preferably, when the polyolefin elastomer comprises a random ethylene-propylene copolymer and a vinyl elastomer, the weight ratio of the random ethylene-propylene copolymer to the vinyl elastomer is 1:(0.1-2), more preferably 1:(0.5-1.5), and even more preferably 1:1.

[0012] Preferably, the hindered amine light stabilizer is selected from at least one of light stabilizer 944, light stabilizer 622, light stabilizer 123, light stabilizer 144, light stabilizer 770, and light stabilizer 202.

[0013] Preferably, the antioxidant is selected from at least one of antioxidant 626, antioxidant 168, antioxidant 618, antioxidant 1010, and antioxidant 1076.

[0014] Preferably, the initiator is selected from at least one of benzoyl peroxide (BPO) and dibenzoyl peroxide (DBPO).

[0015] Preferably, the interfacial compatibilizer is selected from at least one of maleic anhydride and its derivatives and a silane coupling agent.

[0016] Preferably, the raw materials for preparing the modified polypropylene masterbatch include, by weight, 60-95 parts of polypropylene, 0.1-2.5 parts of hindered amine light stabilizer, 0.1-1.2 parts of antioxidant, 0.01-1.2 parts of initiator, and 0.5-3.5 parts of interfacial compatibilizer.

[0017] Further preferably, the raw materials for preparing the modified polypropylene masterbatch include, by weight, 60-90 parts of polypropylene, 0.1-2 parts of hindered amine light stabilizer, 0.1-1 parts of antioxidant, 0.01-1 parts of initiator, and 0.5-3 parts of interfacial compatibilizer.

[0018] Preferably, the method for preparing the modified polypropylene masterbatch comprises the following steps:

[0019] The raw material components are mixed, heated and stirred under a protective gas atmosphere to obtain a crude grafted product, and impurities are removed to obtain the modified polypropylene masterbatch.

[0020] Preferably, the temperature of the heating and stirring is 100-130°C, more preferably 110-125°C.

[0021] Preferably, the stirring speed is 100-300 rpm, more preferably 110-200 rpm.

[0022] Preferably, the stirring time is 30-65 min, more preferably 45-60 min.

[0023] Preferably, the protective gas is selected from nitrogen or a rare gas (such as argon, helium).

[0024] Preferably, the method for preparing the modified polypropylene masterbatch comprises the following steps:

[0025] (1) Mixing a hindered amine light stabilizer, an antioxidant, an initiator, and an interfacial compatibilizer, and stirring to form a uniform solution;

[0026] (2) placing PP powder in a reaction container, then adding the uniform solution described in step (1) into the reaction container, heating and stirring under a protective gas atmosphere to obtain a crude grafted product;

[0027] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed with deionized water to remove unreacted substances, and the residue is dried in an oven to obtain the modified polypropylene masterbatch (PP solid phase grafted product).

[0028] Preferably, the washing is performed 1-10 times, for example, 1 time, 2 times, 5 times, 8 times, or 10 times.

[0029] Preferably, the temperature of the oven during drying is 50-60°C.

[0030] Preferably, the PP composition, by weight, comprises 100 parts of polypropylene resin, 4-15 parts of polyolefin elastomer, and 3-15 parts of modified polypropylene masterbatch; further preferably, the PP composition, by weight, comprises 100 parts of polypropylene resin, 5-10 parts of polyolefin elastomer, and 5-10 parts of modified polypropylene masterbatch.

[0031] A second aspect of the present invention provides a method for preparing a radiation-resistant PP composition.

[0032] Specifically, a method for preparing a radiation-resistant PP composition comprises the following steps:

[0033] The components are melted and extruded to obtain the PP composition.

[0034] Preferably, the extrusion further includes a granulation process.

[0035] Preferably, the preparation method comprises the following steps:

[0036] The polypropylene resin, polyolefin elastomer and modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain the PP composition.

[0037] Preferably, the temperature of the twin-screw extruder is 130-220°C, more preferably 150-220°C.

[0038] Preferably, the screw speed of the twin-screw extruder is 500-800 r / min, more preferably 600-700 r / min.

[0039] The third aspect of the present invention provides an application of a radiation-resistant PP composition.

[0040] A nonwoven fabric comprises the PP composition.

[0041] Preferably, the nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) The PP composition of the present invention comprises a polypropylene resin, a polyolefin elastomer, and a modified polypropylene masterbatch; the polyolefin elastomer comprises at least one of a random ethylene-propylene copolymer and a vinyl elastomer. The raw materials for preparing the modified polypropylene masterbatch include polypropylene, a hindered amine light stabilizer, an antioxidant, an initiator, and an interfacial compatibilizer. Since the modified polypropylene masterbatch is modified in a special way and combined with the polyolefin elastomer and the polypropylene resin, the PP composition has good radiation resistance, and after irradiation, it still maintains good mechanical properties and yellowing resistance.

[0044] (2) The modified polypropylene masterbatch of the present invention can avoid secondary high-temperature melting of the PP masterbatch, has better radiation resistance, and will not precipitate after being placed for a period of time. When a certain amount of polyolefin elastomer is added, the crystallinity in the copolymer can be reduced, thereby making it easy for free radicals to decay and reducing the loss of mechanical energy. After being mixed with the polypropylene resin, the compatibility between the substances is better.

[0045] (3) The PP composition of the present invention is applied to non-woven fabrics, so that the non-woven fabrics have good radiation resistance. For example, after irradiation, the non-woven fabrics are not easy to turn yellow and have good mechanical properties, which is conducive to the use of non-woven fabrics in the medical field. DETAILED DESCRIPTION

[0046] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0047] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0048] Random ethylene-propylene copolymer is provided by ExxonMobil, the product model is Vistalon TM 785.

[0049] The vinyl elastomer is provided by The Dow Chemical Company of the United States, and the product model is PF7266.

[0050] Example 1: A radiation-resistant PP composition, preparation method thereof, and nonwoven fabric

[0051] A radiation-resistant PP composition comprises, by weight, 100 parts of polypropylene resin, 5 parts of random ethylene-propylene copolymer and 5 parts of modified polypropylene masterbatch.

[0052] The preparation process of the modified polypropylene masterbatch is as follows:

[0053] (1) 0.1 part of light stabilizer 944, 0.1 part of antioxidant 626, 0.01 part of initiator dibenzoyl peroxide, and 0.5 part of interfacial compatibilizer maleic anhydride are uniformly mixed to form a mixture;

[0054] (2) placing 60 parts of PP powder in a reaction container, and then adding the mixture obtained in step (1) into the reaction container, stirring at 110° C. and 110 rpm for 60 minutes under nitrogen protection to obtain a crude grafted product;

[0055] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed once with deionized water to remove unreacted substances, and the residue is dried in an oven at 50° C. to obtain a modified polypropylene masterbatch.

[0056] A method for preparing a radiation-resistant PP composition comprises the following steps:

[0057] The polypropylene resin, the random ethylene-propylene copolymer and the modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a PP composition.

[0058] The temperature of the twin-screw extruder was 150°C and the screw speed was 600 r / min.

[0059] A nonwoven fabric comprises the above PP composition. The nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0060] Example 2: A radiation-resistant PP composition, preparation method thereof, and nonwoven fabric

[0061] A radiation-resistant PP composition comprises, by weight, 100 parts of polypropylene resin, 10 parts of random ethylene-propylene copolymer and 10 parts of modified polypropylene masterbatch.

[0062] The preparation process of the modified polypropylene masterbatch is as follows:

[0063] (1) 2 parts of light stabilizer 944, 1 part of antioxidant 626, 1 part of initiator dibenzoyl peroxide, and 3 parts of interfacial compatibilizer maleic anhydride are uniformly mixed to form a mixture;

[0064] (2) placing 90 parts of PP powder in a reaction container, and then adding the mixture obtained in step (1) into the reaction container, stirring at 125° C. and 200 rpm for 45 minutes under nitrogen protection to obtain a crude grafted product;

[0065] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed once with deionized water to remove unreacted substances, and the residue is dried in an oven at 60° C. to obtain a modified polypropylene masterbatch.

[0066] A method for preparing a radiation-resistant PP composition comprises the following steps:

[0067] The polypropylene resin and the random ethylene-propylene copolymer modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a PP composition.

[0068] The temperature of the twin-screw extruder was 220°C and the screw speed was 700 r / min.

[0069] A nonwoven fabric comprises the above PP composition. The nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0070] Example 3: A radiation-resistant PP composition, preparation method thereof, and nonwoven fabric

[0071] A radiation-resistant PP composition comprises, by weight, 100 parts of polypropylene resin, 15 parts of random ethylene-propylene copolymer and 15 parts of modified polypropylene masterbatch.

[0072] The preparation process of the modified polypropylene masterbatch is as follows:

[0073] (1) 1 part of light stabilizer 944, 0.5 part of antioxidant 626, 0.5 part of initiator dibenzoyl peroxide, and 1.5 parts of interfacial compatibilizer maleic anhydride are uniformly mixed to form a mixture;

[0074] (2) placing 95 parts of PP powder in a reaction container, and then adding the mixture obtained in step (1) into the reaction container, stirring at 120° C. and 150 rpm for 50 minutes under nitrogen protection to obtain a crude grafted product;

[0075] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed once with deionized water to remove unreacted substances, and the residue is dried in an oven at 55° C. to obtain a modified polypropylene masterbatch.

[0076] A method for preparing a radiation-resistant PP composition comprises the following steps:

[0077] The polypropylene resin and the random ethylene-propylene copolymer modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a PP composition.

[0078] The temperature of the twin-screw extruder was 180°C and the screw speed was 650 r / min.

[0079] A nonwoven fabric comprises the above PP composition. The nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0080] Example 4: A radiation-resistant PP composition, preparation method thereof, and nonwoven fabric

[0081] A radiation-resistant PP composition comprises, by weight, 100 parts of polypropylene resin, 10 parts of vinyl elastomer and 10 parts of modified polypropylene masterbatch.

[0082] The preparation process of the modified polypropylene masterbatch is as follows:

[0083] (1) 2 parts of light stabilizer 944, 1 part of antioxidant 626, 1 part of initiator dibenzoyl peroxide, and 3 parts of interfacial compatibilizer maleic anhydride are uniformly mixed to form a mixture;

[0084] (2) placing 90 parts of PP powder in a reaction container, and then adding the mixture obtained in step (1) into the reaction container, stirring at 125° C. and 200 rpm for 45 minutes under nitrogen protection to obtain a crude grafted product;

[0085] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed once with deionized water to remove unreacted substances, and the residue is dried in an oven at 60° C. to obtain a modified polypropylene masterbatch.

[0086] A method for preparing a radiation-resistant PP composition comprises the following steps:

[0087] The polypropylene resin, vinyl elastomer and modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a PP composition.

[0088] The temperature of the twin-screw extruder was 220°C and the screw speed was 700 r / min.

[0089] A nonwoven fabric comprises the above PP composition. The nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0090] Example 5: A radiation-resistant PP composition, preparation method thereof, and nonwoven fabric

[0091] A radiation-resistant PP composition comprises, by weight, 100 parts of polypropylene resin, 5 parts of random ethylene-propylene copolymer, 5 parts of vinyl elastomer and 10 parts of modified polypropylene masterbatch.

[0092] The preparation process of the modified polypropylene masterbatch is as follows:

[0093] (1) 2 parts of light stabilizer 944, 1 part of antioxidant 626, 1 part of initiator dibenzoyl peroxide, and 3 parts of interfacial compatibilizer maleic anhydride are uniformly mixed to form a mixture;

[0094] (2) placing 90 parts of PP powder in a reaction container, and then adding the mixture obtained in step (1) into the reaction container, stirring at 125° C. and 200 rpm for 45 minutes under nitrogen protection to obtain a crude grafted product;

[0095] (3) After step (2) is completed, the reaction vessel is evacuated, the crude grafted product is washed once with deionized water to remove unreacted substances, and the residue is dried in an oven at 60° C. to obtain a modified polypropylene masterbatch.

[0096] A method for preparing a radiation-resistant PP composition comprises the following steps:

[0097] The polypropylene resin, random ethylene-propylene copolymer, vinyl elastomer and modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a PP composition.

[0098] The temperature of the twin-screw extruder was 220°C and the screw speed was 700 r / min.

[0099] A nonwoven fabric comprises the above PP composition. The nonwoven fabric is prepared from the above PP composition by a conventional spunbonding process.

[0100] Comparative Example 1

[0101] Compared with Example 2, the difference of Comparative Example 1 is that no modified polypropylene masterbatch is used in Comparative Example 1, and the rest of the process is the same as that of Example 2.

[0102] Comparative Example 2

[0103] Compared with Example 2, the difference of Comparative Example 2 is that no random ethylene-propylene copolymer is used in Comparative Example 2, and the rest of the process is the same as that of Example 2.

[0104] Comparative Example 3

[0105] Compared with Example 2, the difference of Comparative Example 3 is that an equal amount of ethylene-methyl methacrylate copolymer is used to replace the random ethylene-propylene copolymer in Example 1, and the rest of the process is the same as that of Example 2.

[0106] Comparative Example 4

[0107] Compared with Example 2, the difference of Comparative Example 4 is that, in the preparation process of the modified polypropylene masterbatch of Comparative Example 4, acetone thiosemicarbazone is used instead of the light stabilizer 944 in Example 2, and the rest of the process is the same as that of Example 2.

[0108] Product effect testing

[0109] The nonwoven fabrics prepared in the above Examples 1-5 and Comparative Examples 1-4 were taken to test the performance changes of the nonwoven fabrics before and after 40KGy electron beam irradiation for about 30 seconds. The performance data before irradiation are shown in Table 1, and the performance data after irradiation are shown in Table 2.

[0110] Table 1: Test data of examples and comparative examples before irradiation

[0111]

[0112] Table 2: Test data of examples and comparative examples after irradiation

[0113]

[0114]

[0115] It can be seen from Tables 1 and 2 above that the present invention can effectively reduce the decline in mechanical properties of the non-woven fabric after irradiation and can effectively improve the yellowing effect, and it can be seen that the mechanical properties and yellowing resistance of the non-woven fabrics prepared in Examples 1-5 of the present invention are significantly better than those in Comparative Examples 1-4.

Claims

1. A PP composition, characterized in that: Including polypropylene resin, polyolefin elastomer, modified polypropylene masterbatch; The polyolefin elastomer includes at least one of a random ethylene-propylene copolymer and a vinyl elastomer. The raw materials for preparing the modified polypropylene masterbatch include polypropylene, hindered amine light stabilizer, antioxidant, initiator and interface compatibility agent.

2. The PP composition according to claim 1, characterized in that The hindered amine light stabilizer is selected from at least one of light stabilizer 944, light stabilizer 622, light stabilizer 123, light stabilizer 144, light stabilizer 770, and light stabilizer 202.

3. The PP composition according to claim 1, characterized in that The initiator is selected from at least one of benzoyl peroxide and dibenzoyl peroxide.

4. The PP composition according to claim 1, characterized in that The interfacial compatibilizer is selected from at least one of maleic anhydride and its derivatives and a silane coupling agent.

5. The PP composition according to claim 1, characterized in that: The raw materials for preparing the modified polypropylene masterbatch include, by weight, 60-95 parts of polypropylene, 0.1-2.5 parts of hindered amine light stabilizer, 0.1-1.2 parts of antioxidant, 0.01-1.2 parts of initiator, and 0.5-3.5 parts of interface compatibility agent.

6. The PP composition according to claim 1, characterized in that The preparation method of the modified polypropylene masterbatch comprises the following steps: The raw material components are mixed, heated and stirred under a protective gas atmosphere to obtain a crude grafted product, and impurities are removed to obtain the modified polypropylene masterbatch.

7. The PP composition according to any one of claims 1 to 6, characterized in that: Calculated by weight, it comprises 100 parts of polypropylene resin, 4-15 parts of polyolefin elastomer and 3-15 parts of modified polypropylene masterbatch.

8. The method for preparing the PP composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: The components are melted and extruded to obtain the PP composition.

9. The preparation method according to claim 8, characterized in that: The following steps are involved: The polypropylene resin, polyolefin elastomer and modified polypropylene masterbatch are added into a mixer according to weight parts and mixed, and then put into a twin-screw extruder for melt extrusion and granulation to obtain the PP composition.

10. A nonwoven fabric, characterized in that: The PP composition comprises the PP composition according to any one of claims 1 to 7.

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