CN111499976A

CN111499976A - Polypropylene nucleating and cooling difunctional master batch and preparation method and application thereof

Info

Publication number: CN111499976A
Application number: CN202010439106.7A
Authority: CN
Inventors: 张乃斌
Original assignee: Star Better Shanghai Chemical Materials Co ltd
Current assignee: Xingbeida New Materials Co ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-08-07
Anticipated expiration: 2040-05-22
Also published as: CN111499976B

Abstract

The invention relates to the technical field of melt-blowing, in particular to a polypropylene nucleating and cooling difunctional master batch and a preparation method and application thereof. The invention provides a polypropylene nucleation and cooling dual-function master batch, which can efficiently adsorb peroxide through the prepared dual-function master batch with stable foam pores and opening rate, so that the peroxide is uniformly dispersed in the dual-function master batch, can promote the dispersion of the peroxide and a nucleating agent when being used for preparing a melt-blown material, realizes uniform degradation, avoids the occurrence of phenomena such as excessive degradation and the like, obtains the melt-blown material with high melt flow rate, can promote the refining of the crystal grains of the melt-blown material by the nucleating agent and the like, and obtains the melt-blown material with high transparency, can be prepared into non-woven fabrics and the like, and can be used for the fields of filtration, absorption, warm keeping, oil absorption and the like, such as being used for preparing masks and the.

Description

Polypropylene nucleating and cooling difunctional master batch and preparation method and application thereof

Technical Field

The invention relates to the technical field of melt-blowing, in particular to a polypropylene nucleating and cooling difunctional master batch and a preparation method and application thereof.

Background

Melt-blowing (melt-blowing) technology is that the melt extruded by screw is blown by high-speed high-temperature air flow, so that the melt trickle is stretched by higher multiplying power to form superfine short fibers, then the superfine short fibers are stacked on a condensing net curtain or a net-forming roller to form a continuous short fiber net, and then the non-woven fabric is manufactured by self-adhesion or other reinforcement technology. Therefore, it is required that the melt-blown masterbatch has stable high fluidity (melt index is not very high), narrow molecular weight distribution, low ash content, no other product residue, excellent spinning performance and other properties.

In order to obtain the high-fluidity melt-blown master batch, a chemical degradation method can be used, and peroxide can be used for realizing chemical degradation during or before melt-blowing of the polymer to modify the viscosity and molecular weight distribution of the polymer melt, so that the melt-blown master batch is helped to have better forming conditions and product performance (improving electret effect, preventing filament breakage and improving filtration grade) during manufacturing of melt-blown cloth. However, the conventional peroxide has risks in transportation and use due to the relatively active property, so the temperature-reducing master batch is generally adopted to reduce the dangerous grade of the peroxide.

The temperature-lowering master batch is originally used in polypropylene spinning, and has been developed for lowering the high viscosity of polypropylene and preventing decomposition of other auxiliary pigments and the like at high processing temperatures. The cooling master batch can reduce the molecular weight of polypropylene, thereby reducing the processing temperature of the polypropylene. Its main component is organic peroxide. The cooling master batch can generally reduce the spinning temperature by 10-50 ℃, and the temperature environment in the spinning process is improved.

The traditional polypropylene cooling master batch is prepared by taking polyolefin as a carrier, adding organic peroxide and other processing aids, and performing melt extrusion granulation by an extrusion granulator to obtain the cooling master batch. However, the cooling master batch is obtained by a method of melt extrusion granulation, so that the risk of thermal decomposition and explosion of organic peroxide exists; and the content of the organic peroxide in the master batch is not high due to the limitation of decomposition and explosion risks. Therefore, a milder method is needed to prepare the cooling master batch.

In addition, with the maturity of melt-blown processing, higher requirements are provided for the mechanical property, heat resistance, aging resistance, glossiness and the like of melt-blown materials, so that auxiliaries such as nucleating agents and the like are added in the melt-blown processing, but the nucleating agents may have the problems of heat resistance, dispersibility and the like, so that the preparation of the master batch with the cooling and nucleating functions is the key point of the current research.

Disclosure of Invention

In order to solve the above problems, the first aspect of the present invention provides a polypropylene nucleation and cooling dual-function master batch, wherein the preparation raw materials of the dual-function master batch comprise a foaming carrier, a nucleating agent and peroxide;

the nucleating agent accounts for 1-1.5 wt% of the bifunctional master batch;

the peroxide accounts for 7.5-10 wt% of the bifunctional master batch.

As a preferable technical scheme of the invention, the preparation raw materials of the foaming carrier comprise polyolefin and a foaming agent; the polyolefin comprises homopolymerized polyolefin, and the homopolymerized polyolefin is selected from one of polyethylene, polypropylene, polybutadiene and polystyrene.

As a preferable technical scheme of the invention, the melt flow rate of the polypropylene is 1-20 g/10 min.

In a preferred embodiment of the present invention, the polyolefin further comprises a copolymerized polyolefin, and the monomer of the copolymerized polyolefin comprises two or more of C2 to C8 chain monoolefin, C4 to C8 chain diolefin, and cyclic monoolefin.

As a preferable technical scheme of the invention, the melt flow rate of the copolymerized polyolefin is 1-10 g/10 min.

As a preferable technical solution of the present invention, the nucleating agent is one or more selected from sorbitol nucleating agents, carboxylate nucleating agents, phosphate nucleating agents, and polymer nucleating agents.

As a preferred technical solution of the present invention, the preparation method of the foaming carrier comprises the following steps:

heating polyolefin and a nucleating agent to 150-160 ℃, mixing, injecting a foaming agent at the pressure of 15-20 MPa, mixing, and extruding from a mouth membrane, wherein the pressure of the mouth membrane is reduced to 15-20 MPa, so as to obtain a foaming carrier; the open porosity of the foaming carrier is 70-80%.

The second aspect of the present invention provides a preparation method of the above polypropylene nucleation and cooling dual-function masterbatch, which comprises the following steps:

and adsorbing the peroxide by using a foaming carrier to obtain the difunctional master batch.

The third aspect of the invention provides a melt-blown material, wherein the melt-blown material comprises the preparation raw materials of thermoplastic resin and the bifunctional master batch, and the bifunctional master batch accounts for 6-8 wt% of the melt-blown material.

The fourth aspect of the invention provides an application of the polypropylene nucleation and cooling dual-function master batch, which is used for producing polypropylene with high melt index.

Compared with the prior art, the invention has the following beneficial effects: the invention provides a polypropylene nucleation and cooling dual-function master batch, which can efficiently adsorb peroxide through the prepared dual-function master batch with stable foam pores and opening rate, so that the peroxide is uniformly dispersed in the dual-function master batch, can promote the dispersion of the peroxide and a nucleating agent when being used for preparing a melt-blown material, realizes uniform degradation, avoids the occurrence of phenomena such as excessive degradation and the like, obtains the melt-blown material with high melt flow rate, can promote the refining of the crystal grains of the melt-blown material by the nucleating agent and the like, and obtains the melt-blown material with high transparency, can be prepared into non-woven fabrics and the like, and can be used for the fields of filtration, absorption, warm keeping, oil absorption and the like, such as being used for preparing masks and the.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

The present invention is illustrated by the following specific embodiments, but is not limited to the specific examples given below.

The first aspect of the invention provides a polypropylene nucleation and cooling dual-function master batch, and the preparation raw materials of the dual-function master batch comprise a foaming carrier, a nucleating agent and peroxide;

the nucleating agent accounts for 1-1.5 wt% of the bifunctional master batch;

the peroxide accounts for 7.5-10 wt% of the bifunctional master batch.

[ foaming Carrier ]

In one embodiment, the starting materials for preparing the foamed support of the present invention include a polyolefin and a blowing agent.

Polyolefins

In one embodiment, the polyolefin of the present invention comprises a homopolyolefin selected from the group consisting of polyethylene, polypropylene, polybutadiene, polystyrene.

Preferably, the homopolyolefin of the present invention is polypropylene.

Polypropylene is a polymer obtained by addition polymerization of propylene. Is white wax-like material, and has transparent and light appearance. Can resist corrosion of acid, alkali, salt solution and various organic solvents at the temperature of below 80 ℃, and can be decomposed at high temperature and under the action of oxidation. The polypropylene has stable chemical property, is a non-polar material, has excellent electrical property, has certain rigidity, good surface effect and high processing temperature, and is easy to form and process. However, polypropylene is a crystalline polymer, and has properties similar to polyethylene, and hardly flows below the crystalline melting point, and its melt viscosity rapidly decreases above the crystalline melting point. Due to this characteristic, bubbles generated during the polypropylene foaming process are hardly enclosed. In addition, the polypropylene changes from melt to crystalline state by releasing a large amount of heat of crystallization, and the time required for the melt to change into solid is long. The polypropylene has high air permeability generally, and foaming gas is easy to escape, so the polypropylene is suitable for the production of fiber products such as clothes, blankets and the like, medical instruments, automobiles, bicycles, parts, conveying pipelines, chemical containers and the like, and is widely applied to the production of food and medicine packaging because the polypropylene has narrow foaming time and difficult processing. Examples of polypropylene include, but are not limited to, PP6282NE1, PP6302E1, PP1304E3, PP1304E5, PP1304E6, PP2822E2, PP3155E5, PP5032E3, PP5032E5, PP5722E 1; the marine refined CMPP, PPH-MD-105, PP B02, PP T30S, PP S38F, PP F39S, PP T36F, PP C30S and PP T30G.

More preferably, the melt flow rate of the polypropylene is 1-20 g/10 min; further, the melt flow rate of the polypropylene is 1-10 g/10 min.

Melt flow rate (abbreviated as MFR, melt mass flow rate), also referred to as Melt Index (MI), is the gram of melt flowing through a standard capillary over a period of time (typically 10min) in g/10min at a certain temperature and pressure in a standardized melt index apparatus. The melt flow rate is an important reference basis for selecting plastic processing materials and brands, so that the selected raw materials can better meet the requirements of the processing technology, and the reliability and the quality of the formed product are improved. The melt flow rate of the invention is 230 ℃/2.16 kg.

More preferably, the polyolefin of the invention further comprises copolymerized polyolefin, and the monomer of the copolymerized polyolefin comprises two or more of C2-C8 chain monoolefin, C4-C8 chain diolefin and cyclic monoolefin.

Examples of the chain monoolefins having C2-C8 include, but are not limited to, ethylene, propylene, 1-butene and 1-octene.

Examples of the chain diolefins C4 to C8 include, but are not limited to, butadiene and isoprene.

Examples of cyclic monoolefins include, but are not limited to, styrene, cyclohexene, derivatives of styrene, such as halostyrenes.

Still more preferably, the copolymerized polyolefin of the present invention is selected from one or more of ethylene-octene copolymer, ethylene-propylene-hexadiene copolymer, styrene-ethylene-butene-styrene copolymer, and hydrogenated styrene isoprene copolymer.

In a preferred embodiment, the monomers of the copolymeric polyolefin of the present invention comprise a cyclic monoolefin and a chain diolefin in a weight ratio of greater than 60/40; further, the copolymerized polyolefin monomer comprises cyclic monoolefin and chain diolefin, and the weight ratio is 61/39-80/20.

In a more preferred embodiment, the monomers of the copolymerized polyolefin of the present invention include butadiene and styrene; further, the copolymerized polyolefin of the present invention is a styrene-ethylene-butylene-styrene copolymer.

Styrene-ethylene-butylene-styrene copolymer (SEBS for short) is a linear triblock copolymer with polystyrene as the end segment and styrene-butylene copolymer obtained by hydrogenation of polybutadiene as the middle elastic block. SEBS does not contain unsaturated double bonds, so the SEBS has good stability and aging resistance. As examples of the styrene-ethylene-butene-styrene copolymer, there are included, but not limited to, H1221, H1052, H1031, H1041, H1051, H1043, H1141, H1053 of asahi synthesis.

In a further preferred embodiment, the copolymerized polyolefin of the present invention has a melt flow rate of 1 to 10g/10 min.

In a further preferred embodiment, the weight ratio of the copolymerized polyolefin and the homopolymerized polyolefin of the present invention is (0.2 to 0.3): 1; further, the weight ratio of the copolymerized polyolefin to the homopolymerized polyolefin is 0.25: 1.

the applicant has found that by adding copolymerized polyolefin, such as styrene-ethylene-butylene-styrene copolymer, and polypropylene, the foaming stability of polypropylene can be improved, and the collapse of cells can be reduced, which may be because when the copolymerized polyolefin, especially the polyolefin copolymerized with cyclic monomer and chain monomer, is added, because of having similar chain structure, the polypropylene continuous phase and the uniform structure of the dispersed phase of the copolymerized polyolefin can be formed, when foaming, on one hand, the dispersed phase of the copolymerized polyolefin can be used as nucleation point, thereby the crystallization temperature of polypropylene can be increased, the melt strength of polypropylene can be improved, collapse of cells and escape of gas during polypropylene foaming can be reduced, the stability of cells can be improved, on the other hand, the dispersed phase of the copolymerized polyolefin can play the role of physical cross-linking point during melting, the movement of the long chain of the polypropylene is hindered, so that the sensitivity of the melt viscosity of the polypropylene relative to the temperature is reduced, and the melt strength of the polypropylene during foaming is further increased.

In addition, when a chain monomer and a cyclic monomer are copolymerized, particularly when the content of the cyclic monomer is increased, because the cyclic monomer chain segment, such as a polystyrene chain segment, is crystallized first, the polypropylene and polystyrene chain segment is subjected to debonding, the cell wall cracking is improved, the proportion of open pores is improved, the adsorption of a nucleating agent and peroxide is promoted, the dispersion of the nucleating agent and peroxide during the polypropylene melt-blown material is improved, and the performances of the polypropylene melt-blown material, such as transparency, melt flow rate and the like, are improved. When the cyclic monomer of the copolymerized polyolefin is less, the efficiency of opening the pores and the stability of the cells are affected.

Foaming agent

In one embodiment, the blowing agent of the present invention is 8 to 10 wt% of the polyolefin; further, the blowing agent of the present invention is present in an amount of 9 wt% based on the weight of the polyolefin.

Preferably, the blowing agent of the present invention is a physical blowing agent and/or a chemical blowing agent.

Examples of physical blowing agents include, but are not limited to, carbon dioxide, nitrogen, butane, propane, pentane, heptane.

Examples of chemical blowing agents include, but are not limited to, azo-based blowing agents, nitrite-based blowing agents, sulfonyl hydrazide-based blowing agents, and carbonate-based blowing agents.

More preferably, the blowing agent of the present invention is carbon dioxide.

The invention uses carbon dioxide as a foaming agent and adopts supercritical carbon dioxide for foaming and forming. The supercritical foaming is a physical foaming technique, and simultaneously is a microcellular foaming technique, in the processes of injection molding, extrusion and blow molding, firstly, injecting other gases such as carbon dioxide or nitrogen in a supercritical state into a special plasticizing device, fully and uniformly mixing/diffusing the gases and molten raw materials to form single-phase mixed sol, and then guiding the sol to a mold cavity or an extrusion die to ensure that the sol generates large pressure drop, so that the gases are separated out to form a large number of bubble nuclei; and in the subsequent cooling and forming process, the bubble nuclei in the sol continuously grow and are formed, and finally, the foamed plastic product is obtained.

Further preferably, the preparation method of the foaming carrier comprises the following steps:

heating polyolefin and a nucleating agent to 150-160 ℃, mixing, injecting a foaming agent at the pressure of 15-20 MPa, mixing, and extruding from a mouth membrane, wherein the pressure of the mouth membrane is reduced to 15-20 MPa, so as to obtain a foaming carrier; the aperture ratio of the foaming carrier is 70-80%

The pressure at the oral membrane will be the pressure at which the premix flow through the oral membrane drops.

The cells in the foamed material include open cells, which are cells whose walls are not completely closed and which are in direct or indirect communication with other cells, and closed cells, which are closed cells and which are not identical to other cells, wherein the open cell content is the volume percentage of open cells, and can be measured according to methods well known in the art, such as ASTM D2856-94.

The applicant finds that in order to improve the adsorption efficiency and the adsorption uniformity of the peroxide, the applicant adopts carbon dioxide as a foaming agent, and uses the nucleating agent and the polyolefin to act together, so that the nucleating agent can play a role in nucleating when the prepared difunctional master batch is used for melt-blown materials while promoting the formation and the stability of a foaming carrier, thereby achieving the dual functions of nucleating and cooling together with the peroxide.

And the applicant controls the morphology and open cell ratio of cells by extrusion foaming using supercritical carbon dioxide, and the applicant found that when controlling the content of carbon dioxide and the temperature and pressure drop of foaming, the structure of larger cells in the copolymerized polyolefin can be uniformly distributed in smaller cells of polypropylene to promote capillary connection between cells to achieve greater open cell ratio, which is probably because carbon dioxide has different solubility to different polyolefins at different temperatures and pressures, and the solubility of polypropylene to carbon dioxide is greater than that of copolymerized polyolefin, such as styrene-ethylene-butylene-styrene copolymer, during melting of carbon dioxide and polyolefin, so that the nucleation capability of cells at the continuous phase and interface of polypropylene is stronger during foaming, and because the carbon dioxide concentration gradient of polypropylene and copolymerized polyolefin is larger, when the premix is depressurized through a mouth membrane, the system of the premix is unstable, carbon dioxide in a polypropylene continuous phase tends to diffuse to copolymerized polyolefin, the growth of cells in the copolymerized polyolefin is promoted while the nucleation of the cells in the copolymerized polyolefin is promoted, so that the cell size in a dispersed phase is obviously larger than that of the cells in the continuous phase, and the growth of the cells is beneficial to compressing the cell walls of small and small cells in the continuous phase, on one hand, the opening rate is promoted, a structure with uniformly distributed large and small cells is formed, and on the other hand, the adsorption of peroxide is promoted.

And the applicant finds that when the concentration of carbon dioxide is too high or the pressure drop is too high, the aperture ratio is too large, and the adsorption of peroxide is not facilitated, probably because the structure of large holes and small holes is damaged by the too high concentration or pressure of the carbon dioxide, so that the cells are obviously cracked, the capillary holes among the cells are damaged, the capillary phenomenon is influenced, most of the peroxide is adsorbed on the surface, the adsorption efficiency is reduced, and therefore when the polypropylene spray material is used for preparing the polypropylene spray material, the using amount and distribution of the peroxide are influenced, and the flow rate and transparency of the final melt are influenced. Furthermore, the applicants have found that when the carbon dioxide concentration is too low, resulting in a small or even no difference in carbon dioxide concentration between the dispersed and continuous phases, the cells are of similar size and have a thicker wall thickness, the open cell content decreases, affecting the adsorption of peroxide, and when the pressure drop is too great, the cell density increases, but the size decreases, also not contributing to the adsorption of nucleating agent and peroxide.

[ nucleating agent ]

The nucleating agent is a new functional assistant which is suitable for incomplete crystallization plastics such as polyethylene, polypropylene and the like, accelerates the crystallization rate, increases the crystallization density and promotes the grain size to be micronized by changing the crystallization behavior of resin, thereby achieving the purposes of shortening the molding period, and improving the physical and mechanical properties such as the transparency, the surface gloss, the tensile strength, the rigidity, the heat distortion temperature, the impact resistance, the creep resistance and the like of products. In one embodiment, the nucleating agent of the present invention is selected from one or more of sorbitol nucleating agent, carboxylate nucleating agent, phosphate nucleating agent, and polymer nucleating agent.

As examples of sorbitol-based nucleating agents, there may be mentioned, but not limited to, 1- (2-butenyl) sorbitol, 1-butylsorbitol, 1- (2-methylallyl) sorbitol, 1-isobutylsorbitol, 1-vinylsorbitol, 1-ethylsorbitol.

Examples of the carboxylate-based nucleating agent include, but are not limited to, sodium benzoate, p-tert-butyl aluminum hydroxy benzoate.

As examples of the phosphate-based nucleating agent, there may be mentioned, but not limited to, sodium bis (4-tert-butylphenyl) phosphate, such as ADK STAB NA-10 of Asahi electro-chemical industry, Mark 2180 of Witco Argus, USA; sodium 2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate, such as ADK STAB NA-11 from Asahi electro-chemical industry, Irgastab NA-11 from Ciba specialty; bis [2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) ] aluminium phosphate.

Examples of the polymer-based nucleating agent include, but are not limited to, polyethylene-sodium acrylate, polyethylene-zinc acrylate, and ethylene/methacrylate resin.

Preferably, the nucleating agent is phosphate nucleating agent; further, the phosphate nucleating agent is sodium bis (4-tert-butylphenyl) phosphate and/or sodium 2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate; further, the phosphate nucleating agent is 2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) sodium phosphate.

The applicant finds that when the bifunctional master batch provided by the invention is used for preparing polypropylene melt-blown materials, the transparency of the melt-blown materials can be improved, which is probably because the organic phosphonate nucleating agent adsorbed in the bifunctional master batch and the copolymerized polyolefin in the carrier act together, on one hand, the uniform dispersion of the organic phosphonate nucleating agent in the melt-blown materials is promoted, the heterogeneous nucleation effect is realized, the number of microcrystals is increased, the crystal grains are refined, the prepared transparency is improved, and the heterogeneous effect of the organic phosphonate nucleating agent can be reduced and the transparency is further promoted because the copolymerized polyolefin, the nucleating agent and the polypropylene in the carrier have high compatibility; in addition, by using the copolymerized polyolefin, the copolymerized polyolefin can be intertwined with the polypropylene long chain, the regularity and the orderliness of chain segments are reduced, the growth of crystals is hindered, and the refraction and the scattering of large-size vigilance to light are avoided, so that the transparency of the molten spray material is improved.

In addition, the organic phosphonate nucleating agent is also favorable for improving the adsorption of the carrier to the peroxide, mainly because the organic phosphonate nucleating agent contains a benzene ring structure, the peroxide can be promoted to enter large foam pores, the probability that the peroxide is adsorbed into the carrier and deposited in the foam pores is increased, the stability of the peroxide is improved, the decomposition of the peroxide is reduced, and when the organic phosphonate nucleating agent is used for preparing a melt-blown material, the polypropylene can be better degraded, and the polypropylene with better melt flow rate and molecular weight distribution is formed.

[ PEROXIDES ]

The peroxide is not specifically limited in the present invention, and in one embodiment, the peroxide of the present invention is selected from one or more of di-tert-butyl peroxide, 2, 5-dimethyl-2, 5-bis (tert-butyl peroxide) hexane, 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane, and bis (tert-butylperoxydiisopropyl) benzene.

The applicant finds that the use of the difunctional masterbatch can promote the uniformity of the peroxide in melt-blown material processing and realize uniform degradation, mainly because the peroxide and the nucleating agent are released along with the melt-blown material melt processing, but the nucleating agent and the peroxide are uniformly dispersed along with the polyolefin copolymer due to the good compatibility of the polyolefin copolymer contained in the masterbatch, and when the peroxide initiates the generation of free radicals, more active centers are easily induced in the polypropylene molecular chain due to the stronger activity of the free radicals to generate excessive degradation, and the polypropylene chain can be prevented from being excessively broken due to the more active centers by the stabilizing effect of the macrocyclic organic phosphonate and the polyolefin copolymer, so that the molecular weight distribution and the mechanical property are influenced.

The second aspect of the present invention provides a preparation method of the polypropylene nucleation and cooling dual-function masterbatch, which comprises the following steps:

The third aspect of the invention provides a melt-blown material, wherein the melt-blown material comprises the preparation raw materials of thermoplastic resin and the bifunctional master batch, and the bifunctional master batch accounts for 6-8 wt% of the melt-blown material; furthermore, the difunctional master batch accounts for 8 wt% of the melt-blown material.

The thermoplastic resin has the properties of softening by heating and hardening by cooling, and does not react chemically, and such properties are maintained regardless of the number of times heating and cooling are repeated. The thermoplastic resin has good toughness, large damage tolerance, good dielectric constant, unlimited storage period, no need of low-temperature storage, no need of large-scale special equipment such as autoclave for molding, and especially has the characteristics of good recyclability, recoverability, reusability and no environmental pollution, thus being suitable for the development direction of current material environmental protection. The thermoplastic resin is not particularly limited in the present invention, and there may be mentioned polyester, polyamide, polyethylene, polytetrafluoroethylene, polypropylene, polystyrene, polyurethane, polybutylene terephthalate, ethylene-vinyl acetate copolymer, among which polypropylene is the most used resin in melt-blown processing.

Preferably, the melt flow rate of the thermoplastic resin is 2-50 g/10 min.

More preferably, the raw materials for preparing the melt-blown material also comprise an auxiliary agent.

The invention does not specifically limit the auxiliary agent of the spray material, and can be selected from antioxidant, lubricant, hardness regulator, brightener, antistatic agent, pigment and flame retardant according to the application of the spray material.

Examples of antioxidants include, but are not limited to, aromatic amine antioxidants such as diphenylamine and its derivatives and polymers, p-phenylenediamine and its derivatives and polymers, dihydroquinoline and its derivatives and polymers, hindered phenolic antioxidants such as 2, 6-t-butyl-4-methylphenol, bis (3, 5-t-butyl-4-hydroxyphenyl) sulfide, pentaerythritol tetrakis (β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate), thiodipropionate diesters, phosphites, and in a preferred embodiment, the antioxidants of the present invention comprise from 0 to 1 weight percent of the meltblown material.

The lubricant is used for reducing the friction resistance of the friction pair and slowing down the abrasion of the friction pair. Examples of the lubricant include, but are not limited to, silicone oil, white mineral oil, fatty acid amide, barium stearate, magnesium stearate, paraffin wax, polyethylene wax, ethylene bis-stearic acid amide, ethylene-vinyl acetate copolymer, pentaerythritol stearate, ethylene-acrylic acid copolymer, or aromatic phosphate ester; in a preferred embodiment, the lubricant of the present invention is 0 to 1 wt% of the meltblown material.

Antistatic agents are additives that are added to plastics or applied to the surface of molded articles to reduce static buildup. As examples of the antistatic agent, there are, but not limited to, cationic antistatic agents, anionic antistatic agents, nonionic antistatic agents, copolymers of polyether and polyamide, zwitterionic antistatic agents, permanent antistatic agents, modified carbon nanotubes, graphene, metal powder, conductive graphite; in a preferred embodiment, the antistatic agent of the invention is present in an amount of 0 to 1 wt.% based on the weight of the meltblown material.

Pigment means a substance that can color an object. As examples of pigments, including, but not limited to, metal oxides, sulfides, sulfur-selenides, sulfates, silicic acid pigments, carbon black; in a preferred embodiment, the pigment according to the invention is present in an amount of 0 to 1 wt.% based on the weight of the meltblown material.

Flame retardant, functional assistant for providing flame retardancy to inflammable polymer. Examples of the flame retardant include, but are not limited to, organic brominated flame retardants such as decabromodiphenylethane, tetrabromobisphenol a bis (2, 3-dibromopropyl) ether, tris (tribromoneopentyl) phosphate, tris (2, 3-dibromopropyl) isocyanurate, brominated imines, brominated epoxy resins, tris (tribromophenoxy) triazine, tetrabromobisphenol a, tetrabromobisphenol S bis (2, 3-dibromopropyl) ether; hypophosphite flame retardants such as aluminum hypophosphite, calcium hypophosphite, dimethyl aluminum hypophosphite, diethyl aluminum hypophosphite, methyl ethyl aluminum hypophosphite; phosphate flame retardants such as at least one of triphenyl phosphate, resorcinol bis (diphenyl phosphate), bisphenol a bis (diphenyl phosphate), oligomeric aryl phosphates; polyphosphate flame retardants such as ammonium polyphosphate, melamine phosphate, melamine pyrophosphate, melamine polyphosphate; in a preferred embodiment, the flame retardant of the present invention is 0 to 1 wt% of the meltblown material.

The meltblown material of the present invention is prepared according to methods well known in the art, and in one embodiment, the meltblown material of the present invention is prepared by a method comprising the steps of: and melting and blending the preparation raw materials of the melt-blown material, extruding, cooling, granulating and drying to obtain the melt-blown material.

Examples

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

Example 1

The embodiment provides a difunctional master batch, and the preparation raw materials of the difunctional master batch comprise a foaming carrier, a nucleating agent and peroxide; the nucleating agent accounts for 1.25 wt% of the bifunctional master batch; the peroxide accounts for 10 wt% of the bifunctional master batch; the preparation raw materials of the foaming carrier comprise polyolefin and carbon dioxide, wherein the polyolefin comprises styrene-ethylene-butylene-styrene copolymer and polypropylene, and the weight ratio of the polyolefin to the polypropylene is 0.2: 1, wherein the weight percentage of the carbon dioxide in the polyolefin is 8 wt%; the preparation method of the foaming carrier comprises the following steps: melt mixing: heating polyolefin and nucleating agent to 160 ℃, mixing, injecting carbon dioxide at the pressure of 15MPa, mixing, and extruding from a mouth film, wherein the pressure of the mouth film is reduced to 15MPa, so as to obtain the foaming carrier.

The polypropylene was PP6282NE1 (melt flow rate of 1.8g/10min) from exxonmobil.

The styrene-ethylene-butylene-styrene copolymer was H1043 (melt flow rate of 2g/10min, weight ratio of styrene monomer and butadiene monomer of ethylene-butylene-styrene copolymer: 67/33) of Asahi Kasei Chemicals.

The nucleating agent is 2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) sodium phosphate, which is available from ADK STAB NA-11 of Asahi electro-chemical industry in Japan.

The peroxide is di-tert-butyl peroxide.

The embodiment also provides a preparation method of the bifunctional master batch, which comprises the following steps:

The present example also provides a meltblown material prepared from 8 wt% of the above-described difunctional masterbatch and 0.5 wt% of an antioxidant, wherein the thermoplastic resin is polypropylene, PP1304E6 available from exxonmobil (melt flow rate 13g/10min), and the antioxidant is pentaerythritol tetrakis (β - (3, 5-di-tert-butyl 4-hydroxyphenyl) propionate).

The embodiment also provides a preparation method of the melt-blown material, which comprises the following steps: and melting and blending the preparation raw materials of the melt-blown material, extruding, cooling, granulating and drying to obtain the melt-blown material.

Example 2

The embodiment provides a difunctional master batch, and the preparation raw materials of the difunctional master batch comprise a foaming carrier, a nucleating agent and peroxide; the nucleating agent accounts for 1.25 wt% of the bifunctional master batch; the peroxide accounts for 10 wt% of the bifunctional master batch; the preparation raw materials of the foaming carrier comprise polyolefin and carbon dioxide, wherein the polyolefin comprises styrene-ethylene-butylene-styrene copolymer and polypropylene, and the weight ratio of the polyolefin to the polypropylene is 0.3: 1, the weight percentage of the carbon dioxide in the polyolefin is 10 wt%; the preparation method of the foaming carrier comprises the following steps: melt mixing: heating polyolefin and nucleating agent to 150 ℃, mixing, injecting carbon dioxide at the pressure of 20MPa, mixing, and extruding from a mouth film, wherein the pressure of the mouth film is reduced to 20MPa, so as to obtain the foaming carrier.

The polypropylene was PP6302E1 (melt flow rate 1.9g/10min) from Exxon Mobil.

The peroxide is 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane.

Example 3

The embodiment provides a difunctional master batch, and the preparation raw materials of the difunctional master batch comprise a foaming carrier, a nucleating agent and peroxide; the nucleating agent accounts for 1.25 wt% of the bifunctional master batch; the peroxide accounts for 10 wt% of the bifunctional master batch; the preparation raw materials of the foaming carrier comprise polyolefin and carbon dioxide, wherein the polyolefin comprises styrene-ethylene-butylene-styrene copolymer and polypropylene, and the weight ratio of the polyolefin to the polypropylene is 0.25: 1, the weight percentage of the carbon dioxide in the polyolefin is 9 wt%; the preparation method of the foaming carrier comprises the following steps: melt mixing: heating polyolefin and nucleating agent to 155 ℃, mixing, injecting carbon dioxide at the pressure of 18MPa, mixing, and extruding from a mouth film, wherein the pressure of the mouth film is reduced to 18MPa, so as to obtain the foaming carrier.

The polypropylene was PP2822E2 (melt flow rate 4g/10min) from Exxon Mobil.

The peroxide is 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane.

Example 4

The present example provides a dual-function master batch, which is similar to example 3, except that the polyolefin is polypropylene.

The embodiment also provides a preparation method of the bifunctional master batch, and the specific implementation mode is the same as that of embodiment 3.

This example also provides a meltblown material, which is described in example 3.

The present example also provides a method for preparing the meltblown material as described above, and the specific embodiment is the same as in example 3.

Example 5

This example provides a dual function masterbatch, which is specifically embodied in the same manner as in example 3, except that the polypropylene is Exxon Mobil PP3155E5 (melt flow rate 36g/10 min).

Example 6

This example provides a bifunctional mother particle, which is similar to example 3, except that the styrene-ethylene-butylene-styrene copolymer is H1052 from Asahi Kasei Chemicals (melt flow rate 3g/10min, weight ratio of styrene monomer and butadiene monomer of ethylene-butylene-styrene copolymer is 20/80).

Example 7

This example provides a bifunctional masterbatch, which is similar to example 3, except that the styrene-ethylene-butylene-styrene copolymer is H1141 (melt flow rate of 22g/10min, weight ratio of styrene monomer and butadiene monomer of ethylene-butylene-styrene copolymer is 30/70) from Asahi Kasei Chemicals.

Example 8

This example provides a dual function masterbatch, which is specifically prepared in the same manner as example 3, except that the styrene-ethylene-butylene-styrene copolymer was replaced with an ethylene-octene copolymer, which was obtained from POE8450 (melt flow rate of 3g/10min (190 ℃/2.16 kg)).

Example 9

The embodiment of the present invention provides a bifunctional masterbatch, which is the same as in embodiment 3, except that the polyolefin comprises styrene-ethylene-butylene-styrene copolymer and polypropylene, and the weight ratio is 0.5: 1.

Example 10

The embodiment of the present invention provides a bifunctional masterbatch, which is the same as in embodiment 3, except that the carbon dioxide accounts for 4 wt% of the polyolefin.

Example 11

The embodiment of the present invention provides a bifunctional masterbatch, which is the same as in embodiment 3, except that the carbon dioxide accounts for 15 wt% of the polyolefin.

Example 12

The embodiment of the present invention provides a bifunctional master batch, which is the same as in embodiment 3, except that the preparation method of the foaming carrier comprises the following steps: melt mixing: heating polyolefin to 175 ℃, mixing, injecting carbon dioxide under the pressure of 18MPa, and melting and mixing for 40min to obtain a premix; foaming: the premix was stirred at 155 ℃ and extruded through a die, the pressure of which was reduced to 25MPa, to give a foamed support.

Example 13

This example provides a dual function master batch, which is similar to example 3, except that the nucleating agent is sodium bis (4-tert-butyl phenyl) phosphate available from ADK STAB NA-11 of Asahi electro-chemical industry, Japan.

Evaluation of Performance

The following experiments were performed as experimental groups provided in the examples.

1. The opening rate is as follows: the foamed carriers provided in the examples were tested for open cell content according to ASTM D2856-94, wherein the open cell content was 70-80% for grade 1, greater than 80% for grade 2, and less than 70% for grade 3, and the results are shown in table 1.

2. Cell uniformity: the foamed support provided in the examples was cut perpendicular to the extrusion direction, and the cell shape, cell size, dispersion and communication were observed using a scanning electron microscope, and the results are shown in Table 1.

Table 1 performance characterization test

3. Melt flow rate: the melt-blown material provided by the example is tested according to GB T3682 at the melt flow rate of 230 ℃/2.16kg, wherein the melt flow rate is more than 1500g/10min in the 1 stage, less than or equal to 1500g/10min in the 2 stage, greater than 1450g/10min in the 3 stage, less than or equal to 1450g/10min in the 3 stage, greater than 1400g/10min in the 4 stage, less than or equal to 1400g/10min in the 4 stage, greater than 1300g/10min in the 5 stage, and the results are shown in Table 2.

4. Molecular weight distribution index: the spray melts provided in examples were evaluated by measuring the molecular weight distribution index by GPC, wherein the molecular weight distribution index is weight average molecular weight/number average molecular weight, and the smaller the molecular weight distribution index, the narrower the molecular weight distribution, and the molecular weight distribution index was found to be in 1 st stage, 2.7 or more, 2.9 or less, 3 rd stage, 2.9 or more, 4 th stage, 3.5 or less, 3.2 or more, and 5 th stage, 3.5 or more, and the results are shown in table 2.

5. Light transmittance: the meltblown materials provided in the examples were tested for light transmittance according to GB T2410 and evaluated, wherein the light transmittance was 95% or more for level 1, 95% or less for level 2, 90% or more for level 3, 90% or less for level 3, 85% or more for level 4, 85% or less for level 4, 80% or more for level 5, and the results are shown in table 2.

Table 2 characterization test of properties

Examples	Melt flow rate	Molecular weight distribution index	Light transmittance
				1	Level 1	Stage 2	Level 1
2	Level 1	Level 1	Stage 2
				3	Level 1	Level 1	Level 1
4	Grade 5	Grade 5	Grade 5
				5	Grade 5	Grade 5	Grade 5
6	Grade 3	4 stage	Grade 3
				7	4 stage	Grade 5	4 stage
8	Grade 3	Grade 3	Stage 2
				9	Grade 3	Grade 3	Grade 3
10	4 stage	Grade 5	4 stage
				11	4 stage	Grade 5	Grade 3
12	Grade 3	Grade 3	Stage 2
				13	Stage 2	Stage 2	Stage 2

The test results in tables 1 and 2 show that the polypropylene nucleating and cooling dual-function master batch provided by the invention can be used in a melt-blowing process, the prepared melt-blown material has good melt flow rate which can reach 1500g/10min at most, and has lower molecular weight distribution and good transparency, and the polypropylene nucleating and cooling dual-function master batch can be used in various fields such as filtration, absorption, heat preservation and the like.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.

Claims

1. The polypropylene nucleating and cooling difunctional master batch is characterized in that the preparation raw materials of the difunctional master batch comprise a foaming carrier, a nucleating agent and peroxide;

the nucleating agent accounts for 1-1.5 wt% of the bifunctional master batch;

the peroxide accounts for 7.5-10 wt% of the bifunctional master batch.

2. The polypropylene nucleating and cooling difunctional master batch as claimed in claim 1, wherein the raw materials for preparing the foaming carrier comprise polyolefin and a foaming agent; the polyolefin comprises homopolymerized polyolefin, and the homopolymerized polyolefin is selected from one of polyethylene, polypropylene, polybutadiene and polystyrene.

3. The polypropylene nucleating and cooling difunctional master batch as claimed in claim 2, wherein the melt flow rate of polypropylene is 1-20 g/10 min.

4. The polypropylene nucleating and cooling difunctional masterbatch according to claim 2, wherein the polyolefin further comprises a copolymerized polyolefin, and the monomer of the copolymerized polyolefin comprises two or more of C2-C8 chain monoolefin, C4-C8 chain diolefin and cyclic monoolefin.

5. The polypropylene nucleating and cooling difunctional master batch as claimed in claim 4, wherein the melt flow rate of the copolymerized polyolefin is 1-10 g/10 min.

6. The polypropylene nucleating and cooling difunctional master batch as claimed in claim 2, wherein the nucleating agent is one or more selected from sorbitol nucleating agents, carboxylate nucleating agents, phosphate nucleating agents and polymer nucleating agents.

7. The polypropylene nucleating and cooling difunctional master batch as claimed in any one of claims 2 to 6, wherein the preparation method of the foaming carrier comprises the following steps:

8. A preparation method of the polypropylene nucleation and cooling dual-function master batch according to any one of claims 1 to 7, characterized by comprising the following steps:

9. The melt-blown material is characterized in that the preparation raw materials of the melt-blown material comprise thermoplastic resin and the bifunctional master batch according to any one of claims 1 to 7, wherein the bifunctional master batch accounts for 6 to 8 wt% of the melt-blown material.

10. The application of the polypropylene nucleating and cooling difunctional master batch as claimed in any one of claims 1 to 7 is used for producing polypropylene with a high melt index.