Composition, polypropylene resin and preparation method and application thereof

Abstract

The invention relates to the field of high polymer materials, and discloses a composition, polypropylene resin and a preparation method and application thereof. The composition comprises a propylene copolymer, poly (1-butene) and a transparent agent, relative to 100 parts by weight of the propylene copolymer, the poly-1-butene accounts for 1-15 parts by weight, and the transparent agent accounts for 0.1-0.5 part by weight; wherein the propylene copolymer contains a structural unit A as shown in a formula (1) # imgabs 0 # and a structural unit B as shown in a formula (2) # imgabs 1 #; and the content of the structural unit B in the propylene copolymer is 2-4 wt%. The polypropylene resin prepared on the basis of the composition has ultralow haze and excellent mechanical properties, and the haze can be lower than 12% and can be as low as 6%.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a composition, a polypropylene resin, and a preparation method and application thereof. Background Art

[0002] Ultra-transparent polypropylene is a high-end variety of transparent polypropylene, and its excellent transparency is comparable to that of typical transparent materials such as polyester (PET), polycarbonate (PC) and polystyrene (PS). Ultra-transparent polypropylene is widely used in instruments that have high transparency requirements or need to be used or sterilized at high temperatures. At present, the production method of ultra-transparent polypropylene is generally to add a transparent agent to a random polypropylene matrix resin (ethylene-propylene copolymer, propylene-butyl copolymer or ethylene-propylene-butyl copolymer), and reduce the product haze and improve clarity by increasing the nucleation density of the aggregate system, reducing the spherulite size, reducing the crystallinity, and changing the polymer aggregate structure.

[0003] The haze of existing ultra-transparent polypropylene resin products is generally around 15%, the impact resistance is poor, and the shrinkage rate is generally around 1.2%, which is difficult to meet the transparency requirements of specific product fields, seriously limiting the application field of transparent polypropylene resin. Therefore, it is urgent to develop ultra-transparent polypropylene resin products with better transparency and excellent mechanical properties. Summary of the invention

[0004] Aiming at the problems that the transparency of existing ultra-transparent polypropylene resin needs to be further improved, mechanical properties and transparency are difficult to balance, and the shrinkage rate is relatively high, the present invention provides a composition, a polypropylene resin, and a preparation method and application thereof.

[0005] To achieve the above object, the first aspect of the present invention provides a composition, which comprises: a propylene copolymer, poly 1-butene and a clarifier; relative to 100 parts by weight of the propylene copolymer, the poly 1-butene is 1-15 parts by weight, and the clarifier is 0.1-0.5 parts by weight;

[0006] The propylene copolymer contains a structural unit A represented by formula (1) and a structural unit B represented by formula (2); the content of the structural unit B in the propylene copolymer is 2-4% by weight;

[0007]

[0008] A second aspect of the present invention provides a method for preparing a polypropylene resin, the method comprising:

[0009] (1) mixing the components of the composition described in the first aspect to obtain a mixture;

[0010] (2) Extruding and granulating the mixture to obtain polypropylene resin.

[0011] The third aspect of the present invention provides a polypropylene resin prepared by the method described in the second aspect.

[0012] The fourth aspect of the present invention provides the use of the polypropylene resin described in the third aspect in the fields of daily necessities, medical treatment or food.

[0013] Through the above technical scheme, the composition provided by the present invention can be used to prepare a polypropylene resin with ultra-low haze and excellent mechanical properties. Specifically, the polypropylene resin provided by the present invention can achieve a haze of less than 12%, preferably less than 10%, and as low as 6%, and has the advantages of high impact strength and low shrinkage. DETAILED DESCRIPTION

[0014] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0015] The first aspect of the present invention provides a composition, which comprises: a propylene copolymer, poly 1-butene and a clarifier; relative to 100 parts by weight of the propylene copolymer, the poly 1-butene is 1-15 parts by weight, and the clarifier is 0.1-0.5 parts by weight;

[0016] The propylene copolymer contains a structural unit A represented by formula (1) and a structural unit B represented by formula (2); the content of the structural unit B in the propylene copolymer is 2-4% by weight;

[0017]

[0018] According to the present invention, in the composition, preferably, relative to 100 parts by weight of the propylene copolymer, the poly-1-butene is 2.5-12 parts by weight, and the clarifier is 0.2-0.4 parts by weight, so that the polypropylene resin prepared using the composition can have lower haze and better mechanical properties.

[0019] According to the present invention, in the composition, on the basis of satisfying the above-mentioned quantitative relationship, preferably, the weight ratio of the propylene copolymer: poly-1-butene is 100:(5-10), which enables the polypropylene resin prepared using the composition to have further improved impact strength and toughness, and further reduced shrinkage.

[0020] According to the present invention, the propylene copolymer is a random copolymer, in which the structural unit A is a structural unit derived from a propylene monomer, the structural unit B is a structural unit derived from an ethylene monomer, and the content of the structural unit B in the propylene copolymer is relatively high, so that the propylene copolymer can achieve a good balance between rigidity and toughness.

[0021] In the present invention, the method for preparing the propylene copolymer comprises: in the presence of a catalyst and hydrogen, propylene and ethylene are contacted for polymerization reaction to obtain a propylene copolymer. Wherein, the catalyst preferably adopts a composite catalyst system, including a main catalyst, a co-catalyst and an external electron donor; wherein, the main catalyst can be a phthalate catalyst (for example, a DQC401 catalyst and / or a DQC602 catalyst), the co-catalyst can be triethylaluminum (TEAL), and the electron donor can be cyclohexylmethyldimethoxysilane (Donor C); the conditions of the polymerization reaction include: a temperature of 65-75°C, a pressure of 3-4MPa, and a time of 1-2h; a weight ratio of propylene:ethylene of 100:(1-4); and a volume ratio of hydrogen:propylene of (0.002-0.0023):1.

[0022] According to a preferred embodiment of the present invention, the propylene copolymer is prepared by the Spheripol double loop process, and the polymerization reaction is carried out in two series-connected reactors in sequence, so that the prepared propylene copolymer (ethylene-propylene random copolymer) has better impact resistance, bending modulus and narrower molecular weight distribution, and the reaction process is more controllable, the product stability is high, and it is conducive to industrial-scale long-term production. Specifically, in the presence of a catalyst and hydrogen, propylene and ethylene are contacted in a first loop reactor for polymerization reaction, and then enter a second loop reactor to continue the polymerization reaction to obtain the propylene copolymer.

[0023] According to the present invention, in the composition, preferably, the transparent agent is selected from at least one of sorbitol acetal transparent agents, 3,4-dimethylbenzylidene sorbitol transparent agents and substituted aromatic heterocyclic phosphate transparent agents, and more preferably sorbitol acetal transparent agents and / or 3,4-dimethylbenzylidene sorbitol transparent agents.

[0024] In the present invention, the 3,4-dimethylbenzylidene sorbitol-based transparent agent can be selected from one of YL-501S (Ningbo Yulong Technology Co., Ltd.) and / or NA-98 (Chenghe Technology Co., Ltd.); the sorbitol acetal-based transparent agent can be selected from NX-8000K (Milliken & Company) and / or NX8000J (Milliken & Company).

[0025] According to the present invention, more preferably, the transparent agent is selected from at least one of NX-8000K, NA-98 and YL-501S, and most preferably YL-501S.

[0026] According to the present invention, the composition further comprises an antioxidant, an acid scavenger and an antistatic agent on the basis of the above components, so that the polypropylene resin prepared by using the composition can have further optimized performance. Preferably, in the composition, relative to 100 parts by weight of the propylene copolymer, the antioxidant is 0.05-0.15 parts by weight, the acid scavenger is 0.01-0.05 parts by weight, and the antistatic agent is 0.01-0.05 parts by weight.

[0027] According to the present invention, the antioxidant includes a primary antioxidant and a secondary antioxidant.

[0028] In the present invention, the main antioxidant is a phenolic antioxidant, preferably at least one of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester (antioxidant 1010), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione (antioxidant 3114) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (antioxidant 330), and more preferably tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester (antioxidant 1010).

[0029] In the present invention, the auxiliary antioxidant is a phosphite antioxidant, preferably at least one of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (antioxidant 626), bis(2,4-dicumyl) pentaerythritol-bisphosphite (antioxidant 686) and distearyl thiodipropionate, more preferably tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168).

[0030] According to the present invention, preferably, the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(1-3).

[0031] According to the present invention, the acid absorber is selected from calcium stearate and / or calcium stearate, preferably calcium stearate.

[0032] According to the present invention, the antistatic agent is selected from glyceryl monostearate (GMS) and / or antistatic agent HKD-151, preferably glyceryl monostearate.

[0033] The polypropylene resin prepared by using the composition of the present invention as a raw material can achieve a haze of less than 12%, preferably less than 10%, more preferably less than 8%, excellent transparency, and at the same time achieve a tensile yield strength of 25-32MPa, a flexural modulus of 800-1500MPa, and a simple supported beam notched impact strength of 4.5-7kJ / m at 23°C. 2 The melt flow rate at 230°C and a load of 2.16kg is 5-30g / 10min and the shrinkage is 0.7-1%. It has ultra-low haze, high impact strength and low shrinkage, and can well meet the use requirements in daily necessities, medical or food fields.

[0034] According to a most preferred embodiment of the present invention, the composition comprises: a propylene copolymer (wherein, The content of the propylene copolymer is 2-4 weight %), poly 1-butene, transparent agent YL-501S, pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010), tris (2,4-di-tert-butylphenyl) phosphite (antioxidant 168), calcium stearate and glyceryl monostearate (GMS); wherein, relative to 100 weight parts of the propylene copolymer, poly 1-butene is 5-10 weight parts, YL-501S is 0. 3-0.4 parts by weight, the total weight of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010) and tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) is 0.1-0.12 parts by weight, calcium stearate is 0.02-0.04 parts by weight, and monostearate is 0.02-0.04 parts by weight; the weight ratio of the propylene copolymer to poly-1-butene is 100:(5-10). Based on this most preferred composition scheme, the haze of the polypropylene resin can be achieved to be lower than 6.5%, while the tensile yield strength is higher than 28.5MPa, the flexural modulus is 890-1000MPa, and the simple supported beam notched impact strength at 23°C is higher than 5.8kJ / m 2 , the melt flow rate at 230°C and a load of 2.16 kg is 11.8-12.5 g / 10 min, and the shrinkage rate is not higher than 0.8%.

[0035] In the present invention, the haze of the polypropylene resin is measured according to the method specified in GB / T 2410-2008; the tensile yield strength is measured according to the method specified in GB / T 1040.2-2022; the flexural modulus is measured according to the method specified in GB / T 9341-2008; the simply supported beam notched impact strength is measured according to the method specified in GB / T1043.1-2008; the melt flow rate is measured according to the method specified in GB / T3682-2018; and the shrinkage is measured according to the method specified in GB / T 17037.4-2003.

[0036] A second aspect of the present invention provides a method for preparing a polypropylene resin, the method comprising:

[0037] (1) mixing the components of the composition described in the first aspect to obtain a mixture;

[0038] (2) Extruding and granulating the mixture to obtain polypropylene resin.

[0039] According to the present invention, in step (1), there is no particular limitation on the mixing, as long as the components in the composition can be fully mixed to obtain a uniform mixture. For example, the mixing can be performed in a high-speed mixer.

[0040] According to the present invention, in step (2), the conditions for extrusion granulation include: a temperature of 200-230° C. and a screw speed of 200-250 rpm.

[0041] Preferably, the extrusion granulation is carried out in a twin-screw extruder, and the conditions for extrusion granulation further include: the temperature of the rear part of the barrel is 200-230°C, the temperature of the middle part of the barrel is 210-230°C, the temperature of the front part of the barrel is 200-230°C, the temperature of the unloading section is 180-190°C, and the screw speed is 200-250 rpm.

[0042] The third aspect of the present invention provides a polypropylene resin prepared by the method described in the second aspect.

[0043] According to the present invention, the haze of the polypropylene resin is less than 12%, preferably less than 10%, more preferably less than 8%, and the tensile yield strength is 25-32MPa, the flexural modulus is 800-1500MPa, and the simple supported beam notched impact strength at 23°C is 4.5-7kJ / m 2 The melt flow rate at 230°C and a load of 2.16kg is 5-30g / 10min and the shrinkage is 0.7-1%, which can combine ultra-low haze, high impact strength and low shrinkage.

[0044] The fourth aspect of the present invention provides the use of the polypropylene resin described in the third aspect in the fields of daily necessities, medical treatment or food.

[0045] The present invention will be described in detail below by way of examples. In the following examples and comparative examples, unless otherwise specified, all materials used are common commercially available products.

[0046] Preparation Example 1

[0047] This preparation example is used to illustrate the preparation of propylene copolymer:

[0048] Using an ST double loop polypropylene reactor, in the presence of a catalyst (DQC602: triethylaluminum: cyclohexylmethyldimethoxysilane in a weight ratio of 12:76:15) and hydrogen, liquid propylene and ethylene are contacted in a first loop reactor for polymerization reaction, and then enter a second loop reactor for further polymerization reaction to obtain a propylene copolymer (denoted as P-1);

[0049] Among them, the weight ratio of propylene:ethylene is 100:3; the weight ratio of triethylaluminum:propylene is 13:100; in the first loop reactor, the polymerization reaction temperature is 70°C, the pressure is 3.5MPa, the time is 0.5h, and the volume ratio of hydrogen:propylene is 0.0023:1; in the second loop reactor, the polymerization reaction temperature is 70°C, the pressure is 3.5MPa, the time is 0.5h, and the volume ratio of hydrogen:propylene is 0.0023:1.

[0050] In P-1, the structural unit The content is 3% by weight.

[0051] Preparation Example 2

[0052] This preparation example is used to illustrate the preparation of propylene copolymer:

[0053] The method of Preparation Example 1 was followed, except that the weight ratio of propylene to ethylene was 100:1. Other conditions were the same as those of Preparation Example 1, to obtain a propylene copolymer (denoted as P-2).

[0054] In P-2, the structural unit The content is 1% by weight.

[0055] Examples 1-7

[0056] (1) adding propylene copolymer, poly-1-butene, a clarifier, a primary antioxidant, a secondary antioxidant, an acid absorber and an antistatic agent into a high-speed mixer and mixing them uniformly to obtain a mixture;

[0057] (2) The mixed material obtained in step (1) is extruded and granulated in a twin-screw extruder (during the granulation process of the twin-screw extruder, the temperature of the rear part of the barrel is 210° C., the temperature of the middle part of the barrel is 230° C., the temperature of the front part of the barrel is 200° C., the temperature of the unloading section is 190° C., and the screw speed is 250200-250 rpm), and the polypropylene resin is obtained after drying.

[0058] In the above embodiments, the selection and quantity of raw materials are shown in Table 1-1. The obtained polypropylene resin is injection molded into splines of the same specifications (80mm×10mm×4mm, notch depth is 2mm) according to the method specified in GBT-2546.2-2003. The performance parameters of the obtained splines are shown in Table 2.

[0059] Table 1-1

[0060]

[0061] Note: In Table 1-1, the values ​​of the amounts of each component are expressed as parts by weight.

[0062] Comparative Example 1-2

[0063] According to the method of Example 1, the difference is that the selection and quantity of raw materials are as shown in Table 1-2, and the other conditions are the same as in Example 1. The obtained polypropylene resin is injection molded into splines of the same specifications using the same method and parameters as in Example 1. The performance parameters of the obtained splines are shown in Table 2.

[0064] Table 1-2

[0065]

[0066] Note: In Table 1-2, the values ​​of the amounts of each component are expressed as parts by weight.

[0067] Table 2

[0068]

[0069] Note: In Table 2, the melt flow rate data are the results under the conditions of 230℃ and a load of 2.16kg; the simply supported beam notched impact strength data are the results at 23℃.

[0070] It can be seen from the above examples and comparative examples that the polypropylene resin prepared by using the composition of the present invention has ultra-transparency, low shrinkage and excellent impact resistance, and on the basis of maintaining excellent rigidity and toughness, the haze is less than 12%, and the lowest can reach 6%, and at the same time the shrinkage is controlled to be less than 1%, and the lowest reaches 0.7%, which can well meet the high requirements of transparency, mechanical properties and shrinkage of transparent polypropylene resin products in specific product fields (such as medical syringes, stationery, transparent containers, transparent packaging, transparent parts, etc.). In particular, comparative examples 1-2 do not use the composition of the present invention, and the polypropylene resin products prepared cannot have ultra-low haze, high impact strength and low shrinkage.

[0071] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition, characterized in that The composition comprises: a propylene copolymer, poly 1-butene and a transparent agent; relative to 100 parts by weight of the propylene copolymer, the poly 1-butene is 1-15 parts by weight, and the transparent agent is 0.1-0.5 parts by weight; The propylene copolymer contains a structural unit A represented by formula (1) and a structural unit B represented by formula (2); the content of the structural unit B in the propylene copolymer is 2-4% by weight; 2. The composition according to claim 1, wherein With respect to 100 parts by weight of the propylene copolymer, the amount of poly-1-butene is 2.5-12 parts by weight, and the amount of the clarifier is 0.2-0.4 parts by weight.

3. The composition according to claim 1 or 2, wherein The weight ratio of the propylene copolymer to poly-1-butene is 100:(5-10).

4. The composition according to any one of claims 1 to 3, wherein The transparent agent is selected from at least one of sorbitol acetal transparent agents, 3,4-dimethylbenzylidene sorbitol transparent agents and substituted aromatic heterocyclic phosphate transparent agents, preferably sorbitol acetal transparent agents and / or 3,4-dimethylbenzylidene sorbitol transparent agents.

5. The composition according to any one of claims 1 to 4, wherein The composition also includes an antioxidant, an acid absorbent and an antistatic agent; Preferably, relative to 100 parts by weight of the propylene copolymer, the antioxidant is 0.05-0.15 parts by weight, the acid scavenger is 0.01-0.05 parts by weight, and the antistatic agent is 0.01-0.05 parts by weight.

6. The composition according to claim 5, wherein The antioxidant includes a primary antioxidant and a secondary antioxidant; Preferably, the primary antioxidant is a phenolic antioxidant, more preferably at least one of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; Preferably, the auxiliary antioxidant is a phosphite antioxidant, and more preferably at least one of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumyl)pentaerythritol-bisphosphite and distearyl thiodipropionate; Preferably, the weight ratio of the primary antioxidant to the secondary antioxidant is 1:(1-3); Preferably, the acid absorber is selected from calcium stearate and / or zinc stearate, preferably calcium stearate; Preferably, the antistatic agent is selected from glyceryl monostearate and / or antistatic agent HKD-151, preferably glyceryl monostearate.

7. A method for preparing a polypropylene resin, characterized in that: The method comprises: (1) mixing the components of the composition according to any one of claims 1 to 6 to obtain a mixture; (2) Extruding and granulating the mixture to obtain polypropylene resin.

8. The method according to claim 7, wherein: The conditions for the extrusion granulation include: a temperature of 200-230° C. and a screw speed of 200-250 rpm.

9. A polypropylene resin prepared by the method of claim 7 or 8; Preferably, the haze of the polypropylene resin is lower than 12%, preferably lower than 10%, more preferably lower than 8%; Preferably, the melt flow rate of the polypropylene resin at 230° C. and a load of 2.16 kg is 5-30 g / 10 min; Preferably, the tensile yield strength of the polypropylene resin is 25-32 MPa; Preferably, the flexural modulus of the polypropylene resin is 800-1500 MPa; Preferably, the polypropylene resin has a simple supported beam notched impact strength of 4.5-7 kJ / m at 23°C. 2 ; Preferably, the shrinkage rate of the polypropylene resin is 0.7-1%.

10. Use of the polypropylene resin according to claim 9 in the fields of daily necessities, medical treatment or food.

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