Polypropylene primary color master batch and preparation method thereof

Abstract

The invention discloses a polypropylene primary color master batch and a preparation method thereof, the polypropylene primary color master batch comprises polypropylene and an organic peroxide, the average molecular weight of the polypropylene is greater than 160000, and the polypropylene is mixed with the peroxide after being cleaned by an alkaline solution; the ratio of the mass of the organic peroxide to the mass of the polypropylene is not less than 0.15, after the polypropylene and the peroxide are mixed, the polypropylene is oxidized by the catalytic peroxide, and then the polypropylene primary color master batch is obtained through granulation; the preparation method comprises the steps of cleaning and drying, primary mixing, catalytic reaction and granulation. The polypropylene primary color master batch provided by the invention has high surface energy.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a polypropylene-based masterbatch and a preparation method thereof. Background Art

[0002] Polypropylene (PP) is a thermoplastic synthetic resin with outstanding performance. It stands out among thermoplastic lightweight general-purpose plastics because of its colorless and translucent characteristics. The film made of it not only has high transparency, but also has excellent mechanical strength and aging resistance. These unique properties make polypropylene occupy a pivotal position in the printing industry.

[0003] However, as a semi-crystalline non-polar material, polypropylene has an inherently low surface energy, which limits its performance in direct printing applications. In order to improve the printing applicability of polypropylene film, it is usually necessary to modify its surface through methods such as corona or flame treatment to enhance the printing performance. Although these pretreatment measures improve the printing applicability of polypropylene film to a certain extent, they also have the following shortcomings:

[0004] ① The quality control of corona or flame treatment is affected by many factors, including environmental conditions and material properties, which may cause uneven treatment effects on the film surface, which in turn affects the consistency of printing or lamination, and causes defects such as spots or streaks.

[0005] ②Corona or flame treatment requires precise control of corona or flame treatment parameters, such as power, distance and treatment time, to obtain the best effect, which increases the complexity of the operation.

[0006] ③Corona and flame treatment equipment not only requires a certain initial investment, but also requires ongoing maintenance costs. These additional costs will increase production costs and have a certain impact on the economic benefits of production enterprises. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a polypropylene-based masterbatch and a preparation method thereof.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0009] On the one hand, a polypropylene-based masterbatch is characterized in that it includes: polypropylene and organic peroxide; the average molecular weight of the polypropylene is greater than 160,000, and the polypropylene is mixed with the peroxide after being washed with an alkaline solution; the ratio of the mass of the organic peroxide to the mass of the polypropylene is not less than 0.15, and after the polypropylene and the peroxide are mixed, the polypropylene is catalyzed by the peroxide to oxidize the polypropylene, and then granulated to obtain the polypropylene-based masterbatch.

[0010] In the present application, after the polypropylene is cleaned with alkaline solution, the impurities remaining in the polypropylene can be washed away, thereby improving the uniformity of the polypropylene film; at the same time, the alkaline solution can convert some groups on the polypropylene molecular chain, such as -Cl, into oxygen-containing groups, which is beneficial to improving the surface energy of the polypropylene film and improving the printing quality.

[0011] In the present invention, after the organic peroxide oxidizes the polypropylene, the polypropylene will undergo the following changes:

[0012] Molecular weight reduction: Peroxide triggers a free radical reaction in polypropylene, causing the polypropylene molecular chain to break, thereby reducing its molecular weight, which will reduce the hardness and tensile yield strength of polypropylene, making the polypropylene film less likely to break when bent during the printing process, which is beneficial to improving printing quality.

[0013] Reduce surface hardness and rigidity: When the molecular weight of polypropylene is reduced, the surface hardness and rigidity of the polypropylene film will be reduced, thereby reducing the adhesion force required for the ink to adhere to the surface of the polypropylene film, which is beneficial to the stable adhesion of the ink on the polypropylene film and helps to improve the printing quality.

[0014] Improve printing permeability: When the molecular weight of polypropylene is reduced, the surface hardness and rigidity of the polypropylene film will be reduced, and the ink will penetrate into the polypropylene film system more easily, which is conducive to maintaining and improving printing quality in the long term.

[0015] Improving surface energy: Peroxide treatment may cause the polypropylene molecular chain to break and introduce new groups, such as oxygen-containing groups, into the polypropylene molecular chain, which is beneficial to improving the surface energy of the polypropylene film and improving the printing quality.

[0016] Preferably, the organic peroxide is selected from one or more of di-tert-butyl peroxide (DTBP), tert-butyl peroxyhexane, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, methyl ethyl ketone peroxide (MEKP), benzoyl peroxide (BPO), and diethyl propylbenzene peroxide (DCP).

[0017] Specifically, the organic peroxide is benzoyl peroxide.

[0018] Preferably, the organic peroxide is catalyzed by heating to oxidize the polypropylene.

[0019] Preferably, the organic peroxide is catalyzed by ultraviolet irradiation to oxidize the polypropylene.

[0020] In the present invention, the organic peroxide is actively catalyzed to react, which is beneficial to obtaining polypropylene with uniform quality and reducing the residual organic peroxide.

[0021] Preferably, the mass of the organic peroxide is 15% to 25% of the mass of the polypropylene.

[0022] Preferably, the average molecular weight of the polypropylene is 160,000 to 220,000.

[0023] Preferably, it also includes:

[0024] Color powder, the mass of the color powder is 20% to 30% of the mass of the polypropylene;

[0025] A dispersant, wherein the mass of the dispersant is 2% to 3% of the mass of the polypropylene;

[0026] A coupling agent, wherein the mass of the coupling agent is 1% to 3% of the mass of the polypropylene.

[0027] In the present invention, the color powder is one or more of iron oxide red, ultramarine violet, ultramarine blue, molybdenum bismuth yellow, bismuth vanadate, titanium dioxide, titanium yellow powder, azo red, carbon black, cadmium yellow, lead chrome yellow, cobalt blue, and chrome oxide green.

[0028] Specifically, in the present invention, the color powder is titanium yellow powder.

[0029] In the present invention, the dispersant is one or more of liquid paraffin, zinc stearate, polyacrylamide, dispersant YY-5023, and polyethylene wax.

[0030] Specifically, in the present invention, the dispersant is zinc stearate.

[0031] In the present invention, the coupling agent is selected from one or more of an amino coupling agent, a silicon coupling agent, a phosphoric acid coupling agent, a carboxylic acid coupling agent, a polyurethane coupling agent, a titanate coupling agent, an aluminate coupling agent, a bimetallic coupling agent, and a borate coupling agent.

[0032] Specifically, in the present invention, the coupling agent is silane coupling agent kh550.

[0033] On the other hand, a method for preparing a polypropylene-based masterbatch comprises the following steps:

[0034] Cleaning and drying: Grind the polypropylene into powder and soak it in alkali solution, then wash the polypropylene powder with deionized water and dry it;

[0035] First mixing: mixing the dried polypropylene powder and the organic peroxide evenly, and then melting, extruding and slicing to obtain the first slices;

[0036] Catalytic reaction: treating the first slice by heating and / or ultraviolet irradiation to catalyze the reaction between the inorganic peroxide and the polypropylene to obtain the second slice;

[0037] Granulation: The second slice is mixed with color powder, dispersant and coupling agent, and then melt-extruded and granulated to obtain polypropylene-based masterbatch.

[0038] Preferably, in the cleaning and drying step, the polypropylene powder is first soaked in hydrogen peroxide and then soaked in alkali solution.

[0039] In the present invention, hydrogen peroxide can transform some groups on the polypropylene molecular chain, such as nitrogen-containing functional groups, into oxygen-containing groups, which is beneficial to improving the surface energy of the polypropylene film and improving the printing quality.

[0040] Preferably, in the catalytic reaction step, the concentration of hydrogen peroxide is 8% to 20%.

[0041] Preferably, the heating temperature is 70°C to 120°C.

[0042] Preferably, the irradiation intensity of the ultraviolet light is 2000-4000 μW / cm 2 .

[0043] In the present invention, low-intensity ultraviolet rays can catalyze the reaction between organic peroxide and polypropylene without destroying the molecular chain of polypropylene.

[0044] Compared with the prior art, the advantages of the present invention include:

[0045] (1) The polypropylene-based masterbatch provided by the present invention has a reduced molecular weight of polypropylene, which is beneficial to improving the printing performance of the polypropylene film; the organic peroxide can increase the surface energy of the polypropylene film after oxidizing the polypropylene, which is beneficial to improving the printing performance of the polypropylene film;

[0046] (2) Compared with the corona or flame treatment methods in the prior art, the polypropylene-based masterbatch provided by the present invention does not require complicated and expensive processing equipment or complicated operating procedures, and the obtained polypropylene has good uniformity. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to understand the characteristics and effects of the present application, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present application. In case of conflict, the definitions in this specification shall prevail.

[0048] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present application in any way, that is, the content of the present application can be implemented without being limited by any specific theory or mechanism.

[0049] As used herein, "this application" means "the present invention" or "the present disclosure".

[0050] The use of "one", "an", "a kind" or similar expressions to describe the components and technical features described in this application is merely for the convenience of expression and to provide a general meaning to the scope of this application. Therefore, such description should be understood to include one or at least one, and the singular also includes the plural, unless it is obvious that it refers to another meaning.

[0051] In this document, "or its combination" means "or any combination thereof", and "any one", "any one" means "any one", "any one" or "any one".

[0052] As used herein, the terms "comprises," "including," "having," "containing," or any other similar terms are open-ended transitional phrases that are intended to cover non-exclusive inclusions. For example, a composition or article containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or article. In addition, unless otherwise expressly stated, the term "or" refers to an inclusive "or" rather than an exclusive "or." For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). In addition, in this article, the terms "comprising", "including", "having", and "containing" should be interpreted as being specifically disclosed and simultaneously covering closed conjunctions such as "consisting of", "consisting of", and "the remainder is", as well as conjunctions such as "consisting essentially of", "mainly consisting of", "mainly consisting of", "basically containing", "essentially consisting of", "essentially consisting of", and "essentially containing".

[0053] In this article, all features or conditions such as numerical values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have covered and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions), especially integer values. For example, the range description of "1.0 to 8.0" or "between 1.0 and 8.0" or "between 1.0 and 8.0" should be deemed to have specifically disclosed all sub-ranges such as 1.0 to 8.0, 1.0 to 7.0, 2.0 to 8.0, 2.0 to 6.0, 3.0 to 6.0, 4.0 to 8.0, 3.0 to 8.0, etc., and should be deemed to cover endpoint values, especially sub-ranges defined by integer values, and should be deemed to have specifically disclosed individual values ​​such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. Unless otherwise indicated, the foregoing method of interpretation applies to all contents of the entire application, regardless of whether the scope is broad or not.

[0054] If the quantity, concentration or other numerical value or parameter is expressed as a range, a preferred range (or a better range) or a series of upper and lower limits, it should be understood that all ranges consisting of any pair of the upper limit or preferred value (or a better value) of the range and the lower limit or preferred value (or a better value) of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, if a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0055] In this document, numerical values ​​should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range of 39.50 to 40.49.

[0056] In this article, for the use of Markush groups or optional terms to describe the features or examples of the present application, those skilled in the art should understand that all subgroups or any individual elements in the Markush group or option list can also be used to describe the present application. For example, if X is described as "selected from the group consisting of X1, X2 and X3", it also means that the claim that X is X1 and the claim that X is X1 and / or X2 and / or X3 have been fully described. Furthermore, for the use of Markush groups or optional terms to describe the features or examples of the present application, those skilled in the art should understand that any combination of subgroups or individual members of all elements in the Markush group or option list can also be used to describe the present application. Accordingly, for example, if X is described as "selected from the group consisting of X1, X2 and X3", and Y is described as "selected from the group consisting of Y1, Y2 and Y3", it means that the claim that X is X1 and / or X2 and / or X3 and Y is Y1 and / or Y2 and / or Y3 has been fully described.

[0057] Unless otherwise specified, in this application, a compound refers to a chemical substance formed by two or more elements connected by chemical bonds, including small molecule compounds and polymer compounds, but not limited thereto. The interpretation of a compound in this article is not limited to a single chemical substance, but can also be interpreted as the same type of chemical substances with the same composition or the same properties.

[0058] If not otherwise specified, in this application, polymer refers to the product formed by monomer through polymerization reaction, often including many polymer aggregates, each polymer is formed by many simple structural units repeatedly connected by covalent bonds, and monomer is a compound of synthetic polymer. Polymer can include homopolymer, copolymer, prepolymer, etc., and is not limited to this. Homopolymer refers to a polymer polymerized by a monomer. Copolymer includes random copolymer (structure is such as -AABABBBAAABBA-), alternating copolymer (structure is such as -ABABABAB-), graft copolymer (structure is such as -AA(A-BBBB)AA(A-BBBB)AAA-) and block copolymer (structure is such as -AAA AA-BBBBBB-AAAAA-) etc. Prepolymer refers to a polymer with a lower molecular weight between the monomer and the final polymer, and the prepolymer contains reactive functional groups that can further undergo polymerization reaction to obtain a product with a higher molecular weight that is fully cross-linked or hardened. Polymer certainly includes oligomers, and is not limited to this. Oligomers, also known as low polymers, are polymers composed of 2 to 20 repeating units, usually 2 to 5 repeating units.

[0059] Unless otherwise specified, the "resin" in this application is a customary name for a synthetic polymer, which may include monomers, polymers thereof, combinations of monomers, combinations of polymers thereof, or combinations of monomers and polymers thereof, etc., and is not limited thereto.

[0060] If not otherwise specified, in the present application, modified products include products after modification of reactive functional groups of each resin, products after prepolymerization of each resin with other resins, products after crosslinking of each resin with other resins, products after copolymerization of each resin with other resins, and the like.

[0061] Unless otherwise specified, in this application, parts by weight represent relative parts by weight in a composition, which may be any weight unit, such as but not limited to kilograms, kilograms, grams, pounds, etc. For example, 100 parts by weight of polyphenylene ether resin may represent 100 kilograms of polyphenylene ether resin or 100 pounds of polyphenylene ether resin.

[0062] It should be understood that the features disclosed in the various embodiments herein may be arbitrarily combined to form the technical solution of the present application, as long as there is no contradiction in the combination of these features.

[0063] The present application will be described below with specific implementations and examples. It should be understood that these specific implementations and examples are merely illustrative and are not intended to limit the scope of the present application and its use.

[0064] Unless otherwise stated, the methods, reagents and conditions used in the following preparation examples, comparative examples and examples are conventional methods, reagents and conditions in the art.

[0065] In the following descriptions:

[0066] Polypropylene: 5 specifications, with average molecular weights of 120,000, 160,000, 190,000, 220,000, and 250,000;

[0067] Benzoyl peroxide: active ingredient ≥99%, density 1.334g / cm 3 ;

[0068] Silane coupling agent kh550: effective substance ≥99%, density 1.045g / ml;

[0069] Titanium yellow powder: effective substance ≥99.9%, 800 mesh;

[0070] Zinc stearate: active substance ≥99%, free acid ≤0.5%, zinc content 14.5%, 2000 mesh.

[0071] Example

[0072] Example 1

[0073] The raw materials used in this embodiment include: 1 kg of polypropylene with an average molecular weight of 160,000, 150 g of benzoyl peroxide, 10 g of silane coupling agent KH550, 200 g of titanium yellow powder, and 20 g of zinc stearate.

[0074] The preparation method of this embodiment includes:

[0075] S1, grind polypropylene into 200 mesh powder and soak it in 15% NaOH solution for 10 minutes, then wash the polypropylene powder with deionized water, and then dry the polypropylene powder at 70°C;

[0076] S2, mixing the polypropylene powder dried in step S1 with benzoyl peroxide and stirring evenly, and then melt-extruding and slicing, the slice thickness is 1 mm, to obtain a first slice;

[0077] S3, keeping the first slice at 70° C. for 6 h to obtain a second slice;

[0078] S4, the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate are mixed and melt-extruded to form granules at an extrusion temperature of 170° C. to obtain polypropylene-based masterbatch.

[0079] Example 2

[0080] The difference between this embodiment and embodiment 1 is that the benzoyl peroxide in the raw materials used in this embodiment is 200g.

[0081] Example 3

[0082] The difference between this embodiment and embodiment 1 is that the amount of benzoyl peroxide in the raw materials used in this embodiment is 250 g.

[0083] Example 4

[0084] The raw materials used in this embodiment include: 1 kg of polypropylene with an average molecular weight of 190,000, 150 g of benzoyl peroxide, 20 g of silane coupling agent KH550, 250 g of titanium yellow powder, and 25 g of zinc stearate.

[0085] The preparation method of this embodiment includes:

[0086] S1. After grinding polypropylene into 200 mesh powder, soak it in 8% hydrogen peroxide for 5 minutes, then soak it in 15% NaOH solution for 10 minutes, then wash the polypropylene powder with deionized water, and then dry the polypropylene powder at 70°C;

[0087] S2, mixing the polypropylene powder dried in step S1 with benzoyl peroxide and stirring evenly, and then melt-extruding and slicing, the slice thickness is 1 mm, to obtain a first slice;

[0088] S3, keeping the first slice at 120° C. for 6 h to obtain a second slice;

[0089] S4, the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate are mixed and melt-extruded to form granules at an extrusion temperature of 170° C. to obtain polypropylene-based masterbatch.

[0090] Example 5

[0091] The difference between this embodiment and embodiment 4 is that the concentration of hydrogen peroxide in step S1 is 20%.

[0092] Example 6

[0093] The raw materials used in this embodiment include: 1 kg of polypropylene with an average molecular weight of 220,000, 150 g of benzoyl peroxide, 30 g of silane coupling agent KH550, 300 g of titanium yellow powder, and 30 g of zinc stearate.

[0094] The preparation method of this embodiment includes:

[0095] S1. Grind the polypropylene into 200 mesh powder, soak it in 15% NaOH solution for 10 min, then wash the polypropylene powder with deionized water, and then dry the polypropylene powder at 70°C;

[0096] S2, mixing the polypropylene powder dried in step S1 with benzoyl peroxide and stirring evenly, and then melt-extruding and slicing, the slice thickness is 1 mm, to obtain a first slice;

[0097] S3: After the first slice is flattened, the irradiation intensity is 2000 μW / cm 2 Irradiate under ultraviolet light for 4 hours to obtain the second slice;

[0098] S4, the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate are mixed and melt-extruded to form granules at an extrusion temperature of 170° C. to obtain polypropylene-based masterbatch.

[0099] Example 7

[0100] The difference between this embodiment and embodiment 6 is that the irradiation intensity in step S3 is 4000 μW / cm 2 .

[0101] Comparative Example

[0102] Comparative Example 1

[0103] The raw materials used in this comparative example include: 1 kg of polypropylene with an average molecular weight of 160,000, 10 g of silane coupling agent kh550, 200 g of titanium yellow powder, and 20 g of zinc stearate.

[0104] The preparation method of this comparative example comprises:

[0105] D1. Grind the polypropylene into 200 mesh powder and soak it in 15% NaOH solution for 10 min. Then wash the polypropylene powder with deionized water and dry it at 70°C.

[0106] D2, melt-extrude the polypropylene powder dried in step D1 and slice it, the thickness of the slice is 1 mm, to obtain the first slice;

[0107] D3, keeping the first slice at 70°C for 6 hours to obtain the second slice;

[0108] D4. Mix the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate, and then melt-extrude and granulate them at an extrusion temperature of 170°C to obtain polypropylene-based masterbatch.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is that the benzoyl peroxide in the raw materials used in this example is 400g.

[0111] Comparative Example 3

[0112] The difference between this comparative example and Example 1 is that the average molecular weight of the polypropylene in the raw material used in this example is 120,000.

[0113] Comparative Example 4

[0114] The difference between this comparative example and Example 1 is that the average molecular weight of the polypropylene in the raw material used in this example is 250,000.

[0115] Comparative Example 5

[0116] The raw materials used in this comparative example include: 1 kg of polypropylene with an average molecular weight of 160,000, 150 g of benzoyl peroxide, 10 g of silane coupling agent KH550, 200 g of titanium yellow powder, and 20 g of zinc stearate.

[0117] The preparation method of this comparative example comprises:

[0118] D1. Dry polypropylene at 70°C;

[0119] D2, mixing the polypropylene powder dried in step D1 with benzoyl peroxide and stirring evenly, and then melt-extruding and slicing, the slice thickness is 1 mm, to obtain a first slice;

[0120] D3, keeping the first slice at 70°C for 6 hours to obtain the second slice;

[0121] D4. Mix the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate, and then melt-extrude and granulate them at an extrusion temperature of 170°C to obtain polypropylene-based masterbatch.

[0122] Comparative Example 6

[0123] The raw materials used in this comparative example include: 1 kg of polypropylene with an average molecular weight of 160,000, 150 g of benzoyl peroxide, 10 g of silane coupling agent KH550, 200 g of titanium yellow powder, and 20 g of zinc stearate.

[0124] The preparation method of this comparative example comprises:

[0125] D1. Grind the polypropylene into 200 mesh powder and soak it in 15% NaOH solution for 10 min. Then wash the polypropylene powder with deionized water and dry it at 70°C.

[0126] D2, mixing the polypropylene powder dried in step D1 with benzoyl peroxide and stirring evenly, and then melt-extruding and slicing, the slice thickness is 1 mm, to obtain a first slice;

[0127] D3, placing the first slice at 20°C for 6 hours to obtain a second slice;

[0128] D4. Mix the second slice, silane coupling agent KH550, titanium yellow powder and zinc stearate, and then melt-extrude and granulate them at an extrusion temperature of 170°C to obtain polypropylene-based masterbatch.

[0129] Table 1 Differences in raw materials and preparation processes used in Examples 1 to 7 and Comparative Examples 1 to 6

[0130]

[0131] Performance Testing

[0132] The polypropylene masterbatches prepared in Examples 1 to 7 and Comparative Examples 1 to 6 were melt-extruded, cast and biaxially stretched to obtain corresponding polypropylene films, with the stretching temperature being 150° C. and the stretching ratio being 3 times.

[0133] The contact angles of the polypropylene films corresponding to Examples 1 to 7 and Comparative Examples 1 to 6 were tested by an antenna tester, unit: °.

[0134] Table 2 Contact angles of polypropylene films obtained in Examples 1 to 7 and Comparative Examples 1 to 6

[0135] Experimental example Contact angle / ° Experimental example Contact angle / ° Example 1 68.1 Comparative Example 1 81.1 Example 2 67.6 Comparative Example 2 76.4 Example 3 67.2 Comparative Example 3 67.1 Example 4 67.4 Comparative Example 4 73.5 Example 5 67.1 Comparative Example 5 69.2 Example 6 66.7 Comparative Example 6 77.4 Example 7 66.5

[0136] According to Table 2 above, by comparing Example 1 with Comparative Examples 1-2, it can be seen that the polypropylene-based masterbatch obtained in Example 1 has better surface energy, and the possible reason is that treating polypropylene with an appropriate amount of peroxide is beneficial to improving the surface energy of the polypropylene film.

[0137] Although the polypropylene film corresponding to Comparative Example 3 has good surface energy, it is too soft and has poor mechanical properties.

[0138] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, some simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A polypropylene-based masterbatch, characterized in that: include: Polypropylene and organic peroxide; the average molecular weight of the polypropylene is greater than 160,000, and the polypropylene is washed with an alkaline solution and then mixed with the peroxide; The ratio of the mass of the organic peroxide to the mass of the polypropylene is not less than 0.

15. After the polypropylene and the peroxide are mixed, the polypropylene is oxidized by catalyzing the peroxide, and then granulated to obtain a polypropylene-based masterbatch.

2. The polypropylene-based masterbatch according to claim 1, characterized in that: The organic peroxide is selected from one or more of di-tert-butyl peroxide, tert-butyl peroxyhexane, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, methyl ethyl ketone peroxide, benzoyl peroxide, and diethyl propylbenzene peroxide.

3. A polypropylene-based masterbatch according to claim 2, characterized in that: The organic peroxide is catalyzed by heating to oxidize the polypropylene; And / or, the organic peroxide is catalyzed by ultraviolet irradiation to oxidize the polypropylene.

4. The polypropylene-based masterbatch according to claim 1, characterized in that: The mass of the organic peroxide is 15% to 25% of the mass of the polypropylene; And / or, the average molecular weight of the polypropylene is 160,000 to 220,000.

5. The polypropylene-based masterbatch according to claim 1, characterized in that: Also includes: Color powder, the mass of the color powder is 20% to 30% of the mass of the polypropylene; A dispersant, wherein the mass of the dispersant is 2% to 3% of the mass of the polypropylene; A coupling agent, wherein the mass of the coupling agent is 1% to 3% of the mass of the polypropylene.

6. A method for preparing polypropylene-based masterbatch as claimed in claim 1, characterized in that: The steps include: Cleaning and drying: Grind the polypropylene into powder and soak it in alkali solution, then wash the polypropylene powder with deionized water and dry it; First mixing: mixing the dried polypropylene powder and the organic peroxide evenly, and then melting, extruding and slicing to obtain the first slices; Catalytic reaction: treating the first slice by heating and / or ultraviolet irradiation to catalyze the reaction between the inorganic peroxide and the polypropylene to obtain the second slice; Granulation: The second slice is mixed with color powder, dispersant and coupling agent, and then melt-extruded and granulated to obtain polypropylene-based masterbatch.

7. The preparation method according to claim 6, characterized in that: In the cleaning and drying step, the polypropylene powder is firstly soaked in hydrogen peroxide and then soaked in alkali solution.

8. The preparation method according to claim 7, characterized in that: In the catalytic reaction step, the concentration of hydrogen peroxide is 8% to 20%.

9. The preparation method according to claim 6, characterized in that: The heating temperature is 70℃~120℃.

10. The preparation method according to claim 6, characterized in that: The irradiation intensity of the ultraviolet light is 2000-4000 μW / cm 2 .

Images